Commit Graph

5243 Commits

Author SHA1 Message Date
Linus Torvalds
a5ba183bde hardening updates for v6.18-rc1
- Clean up usage of TRAILING_OVERLAP() (Gustavo A. R. Silva)
 
 - lkdtm: fortify: Fix potential NULL dereference on kmalloc failure
   (Junjie Cao)
 
 - Add str_assert_deassert() helper (Lad Prabhakar)
 
 - gcc-plugins: Remove TODO_verify_il for GCC >= 16
 
 - kconfig: Fix BrokenPipeError warnings in selftests
 
 - kconfig: Add transitional symbol attribute for migration support
 
 - kcfi: Rename CONFIG_CFI_CLANG to CONFIG_CFI
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Merge tag 'hardening-v6.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull hardening updates from Kees Cook:
 "One notable addition is the creation of the 'transitional' keyword for
  kconfig so CONFIG renaming can go more smoothly.

  This has been a long-standing deficiency, and with the renaming of
  CONFIG_CFI_CLANG to CONFIG_CFI (since GCC will soon have KCFI
  support), this came up again.

  The breadth of the diffstat is mainly this renaming.

   - Clean up usage of TRAILING_OVERLAP() (Gustavo A. R. Silva)

   - lkdtm: fortify: Fix potential NULL dereference on kmalloc failure
     (Junjie Cao)

   - Add str_assert_deassert() helper (Lad Prabhakar)

   - gcc-plugins: Remove TODO_verify_il for GCC >= 16

   - kconfig: Fix BrokenPipeError warnings in selftests

   - kconfig: Add transitional symbol attribute for migration support

   - kcfi: Rename CONFIG_CFI_CLANG to CONFIG_CFI"

* tag 'hardening-v6.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  lib/string_choices: Add str_assert_deassert() helper
  kcfi: Rename CONFIG_CFI_CLANG to CONFIG_CFI
  kconfig: Add transitional symbol attribute for migration support
  kconfig: Fix BrokenPipeError warnings in selftests
  gcc-plugins: Remove TODO_verify_il for GCC >= 16
  stddef: Introduce __TRAILING_OVERLAP()
  stddef: Remove token-pasting in TRAILING_OVERLAP()
  lkdtm: fortify: Fix potential NULL dereference on kmalloc failure
2025-09-29 17:48:27 -07:00
Linus Torvalds
722df25ddf kernel-6.18-rc1.clone3
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Merge tag 'kernel-6.18-rc1.clone3' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

Pull copy_process updates from Christian Brauner:
 "This contains the changes to enable support for clone3() on nios2
  which apparently is still a thing.

  The more exciting part of this is that it cleans up the inconsistency
  in how the 64-bit flag argument is passed from copy_process() into the
  various other copy_*() helpers"

[ Fixed up rv ltl_monitor 32-bit support as per Sasha Levin in the merge ]

* tag 'kernel-6.18-rc1.clone3' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
  nios2: implement architecture-specific portion of sys_clone3
  arch: copy_thread: pass clone_flags as u64
  copy_process: pass clone_flags as u64 across calltree
  copy_sighand: Handle architectures where sizeof(unsigned long) < sizeof(u64)
2025-09-29 10:36:50 -07:00
Kevin Brodsky
200b0d2508 arm64: mm: Move KPTI helpers to mmu.c
create_kpti_ng_temp_pgd() is currently defined (as an alias) in
mmu.c without matching declaration in a header; instead cpufeature.c
makes its own declaration. This is clearly not pretty, and as commit
ceca927c86 ("arm64: mm: Fix CFI failure due to kpti_ng_pgd_alloc
function signature") showed, it also makes it very easy for the
prototypes to go out of sync.

All this would be much simpler if kpti_install_ng_mappings() and
associated functions lived in mmu.c, where they logically belong.
This is what this patch does:
- Move kpti_install_ng_mappings() and associated functions from
  cpufeature.c to mmu.c, add a declaration to <asm/mmu.h>
- Remove create_kpti_ng_temp_pgd() and just call
  __create_pgd_mapping_locked() directly instead
- Mark all these functions __init
- Move __initdata after kpti_ng_temp_alloc (as suggested by
  checkpatch)

Reviewed-by: Ryan Roberts <ryan.roberts@arm.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com>
Reviewed-by: Yeoreum Yun <yeoreum.yun@arm.com>
[will: Fix conflicts with init_idmap_kpti_bbml2_flag()]
Signed-off-by: Will Deacon <will@kernel.org>
2025-09-25 14:47:19 +01:00
Yang Shi
195a1b7d83 arm64: kprobes: call set_memory_rox() for kprobe page
The kprobe page is allocated by execmem allocator with ROX permission.
It needs to call set_memory_rox() to set proper permission for the
direct map too. It was missed.

Fixes: 10d5e97c1b ("arm64: use PAGE_KERNEL_ROX directly in alloc_insn_page")
Cc: <stable@vger.kernel.org>
Signed-off-by: Yang Shi <yang@os.amperecomputing.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2025-09-25 13:56:48 +01:00
Menglong Dong
35561bab76 arch: Add the macro COMPILE_OFFSETS to all the asm-offsets.c
The include/generated/asm-offsets.h is generated in Kbuild during
compiling from arch/SRCARCH/kernel/asm-offsets.c. When we want to
generate another similar offset header file, circular dependency can
happen.

For example, we want to generate a offset file include/generated/test.h,
which is included in include/sched/sched.h. If we generate asm-offsets.h
first, it will fail, as include/sched/sched.h is included in asm-offsets.c
and include/generated/test.h doesn't exist; If we generate test.h first,
it can't success neither, as include/generated/asm-offsets.h is included
by it.

In x86_64, the macro COMPILE_OFFSETS is used to avoid such circular
dependency. We can generate asm-offsets.h first, and if the
COMPILE_OFFSETS is defined, we don't include the "generated/test.h".

And we define the macro COMPILE_OFFSETS for all the asm-offsets.c for this
purpose.

Signed-off-by: Menglong Dong <dongml2@chinatelecom.cn>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2025-09-25 09:57:15 +02:00
Kees Cook
23ef9d4397 kcfi: Rename CONFIG_CFI_CLANG to CONFIG_CFI
The kernel's CFI implementation uses the KCFI ABI specifically, and is
not strictly tied to a particular compiler. In preparation for GCC
supporting KCFI, rename CONFIG_CFI_CLANG to CONFIG_CFI (along with
associated options).

Use new "transitional" Kconfig option for old CONFIG_CFI_CLANG that will
enable CONFIG_CFI during olddefconfig.

Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Link: https://lore.kernel.org/r/20250923213422.1105654-3-kees@kernel.org
Signed-off-by: Kees Cook <kees@kernel.org>
2025-09-24 14:29:14 -07:00
Jiapeng Chong
ea0b39168d arm64: cpufeature: Remove duplicate asm/mmu.h header
./arch/arm64/kernel/cpufeature.c: asm/mmu.h is included more than once.

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Signed-off-by: Will Deacon <will@kernel.org>
2025-09-24 16:44:44 +01:00
Will Deacon
be9c94ca4e Merge branch 'for-next/vdso' into for-next/core
* for-next/vdso:
  arm64: vdso32: Respect -Werror from kbuild
  arm64: vdso32: Stop suppressing warnings
2025-09-24 16:35:10 +01:00
Will Deacon
4e4e36dce3 Merge branch 'for-next/uprobes' into for-next/core
* for-next/uprobes:
  arm64: probes: Fix incorrect bl/blr address and register usage
  uprobes: uprobe_warn should use passed task
  arm64: Kconfig: Remove GCS restrictions on UPROBES
  arm64: uprobes: Add GCS support to uretprobes
  arm64: probes: Add GCS support to bl/blr/ret
  arm64: uaccess: Add additional userspace GCS accessors
  arm64: uaccess: Move existing GCS accessors definitions to gcs.h
  arm64: probes: Break ret out from bl/blr
2025-09-24 16:35:06 +01:00
Will Deacon
77dfca70ba Merge branch 'for-next/mm' into for-next/core
* for-next/mm:
  arm64: map [_text, _stext) virtual address range non-executable+read-only
  arm64: Enable vmalloc-huge with ptdump
  arm64: mm: split linear mapping if BBML2 unsupported on secondary CPUs
  arm64: mm: support large block mapping when rodata=full
  arm64: Enable permission change on arm64 kernel block mappings
  arm64/Kconfig: Remove CONFIG_RODATA_FULL_DEFAULT_ENABLED
  arm64: mm: Rework the 'rodata=' options
  arm64: mm: Represent physical memory with phys_addr_t and resource_size_t
  arm64: mm: Make map_fdt() return mapped pointer
  arm64: mm: Cast start/end markers to char *, not u64
2025-09-24 16:34:34 +01:00
Will Deacon
30f9386820 Merge branch 'for-next/misc' into for-next/core
* for-next/misc:
  arm64: Kconfig: Make CPU_BIG_ENDIAN depend on BROKEN
  arm64: Kconfig: Spell out "ARMv9.4" in menuconfig text
  arm64/fpsimd: simplify sme_setup()
2025-09-24 16:34:06 +01:00
Will Deacon
7df73a0049 Merge branch 'for-next/entry' into for-next/core
* for-next/entry:
  arm/syscalls: mark syscall invocation as likely in invoke_syscall
  arm64: entry: Switch to generic IRQ entry
  arm64: entry: Move arm64_preempt_schedule_irq() into __exit_to_kernel_mode()
  arm64: entry: Refactor preempt_schedule_irq() check code
  entry: Add arch_irqentry_exit_need_resched() for arm64
  arm64: entry: Use preempt_count() and need_resched() helper
  arm64: entry: Rework arm64_preempt_schedule_irq()
  arm64: entry: Refactor the entry and exit for exceptions from EL1
  arm64: ptrace: Replace interrupts_enabled() with regs_irqs_disabled()
2025-09-24 16:34:02 +01:00
Will Deacon
3d751c56c9 Merge branch 'for-next/cpufeature' into for-next/core
* for-next/cpufeature:
  arm64: cpufeature: add Neoverse-V3AE to BBML2 allow list
  arm64: errata: Apply workarounds for Neoverse-V3AE
  arm64: cputype: Add Neoverse-V3AE definitions
  arm64: cpufeature: add AmpereOne to BBML2 allow list
  arm64: cpufeature: Add Olympus MIDR to BBML2 allow list
  arm64: cputype: Add NVIDIA Olympus definitions
  arm64: cputype: Remove duplicate Cortex-X1C definitions
  arm64: errata: Expand speculative SSBS workaround for Cortex-A720AE
  arm64: cputype: Add Cortex-A720AE definitions
  arm64/hwcap: Add hwcap for FEAT_LSFE
2025-09-24 16:33:53 +01:00
Will Deacon
5647d32f51 Merge branch 'for-next/cca' into for-next/core
* for-next/cca:
  arm64: acpi: Enable ACPI CCEL support
  arm64: Enable EFI secret area Securityfs support
  arm64: realm: ioremap: Allow mapping memory as encrypted
2025-09-24 16:33:25 +01:00
Can Peng
da9e5c04be arm/syscalls: mark syscall invocation as likely in invoke_syscall
The invoke_syscall() function is overwhelmingly called for
valid system call entries. Annotate the main path with likely()
to help the compiler generate better branch prediction hints,
reducing CPU pipeline stalls due to mispredictions.

This is a micro-optimization targeting syscall-heavy workloads [1].

Link: https://lore.kernel.org/r/20250922121730.986761-1-pengcan@kylinos.cn [1]
Signed-off-by: Can Peng <pengcan@kylinos.cn>
Signed-off-by: Will Deacon <will@kernel.org>
2025-09-22 13:26:16 +01:00
Omar Sandoval
5973a62efa arm64: map [_text, _stext) virtual address range non-executable+read-only
Since the referenced fixes commit, the kernel's .text section is only
mapped starting from _stext; the region [_text, _stext) is omitted. As a
result, other vmalloc/vmap allocations may use the virtual addresses
nominally in the range [_text, _stext). This address reuse confuses
multiple things:

1. crash_prepare_elf64_headers() sets up a segment in /proc/vmcore
   mapping the entire range [_text, _end) to
   [__pa_symbol(_text), __pa_symbol(_end)). Reading an address in
   [_text, _stext) from /proc/vmcore therefore gives the incorrect
   result.
2. Tools doing symbolization (either by reading /proc/kallsyms or based
   on the vmlinux ELF file) will incorrectly identify vmalloc/vmap
   allocations in [_text, _stext) as kernel symbols.

In practice, both of these issues affect the drgn debugger.
Specifically, there were cases where the vmap IRQ stacks for some CPUs
were allocated in [_text, _stext). As a result, drgn could not get the
stack trace for a crash in an IRQ handler because the core dump
contained invalid data for the IRQ stack address. The stack addresses
were also symbolized as being in the _text symbol.

Fix this by bringing back the mapping of [_text, _stext), but now make
it non-executable and read-only. This prevents other allocations from
using it while still achieving the original goal of not mapping
unpredictable data as executable. Other than the changed protection,
this is effectively a revert of the fixes commit.

Fixes: e2a073dde9 ("arm64: omit [_text, _stext) from permanent kernel mapping")
Cc: stable@vger.kernel.org
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Will Deacon <will@kernel.org>
2025-09-22 11:58:17 +01:00
Ryan Roberts
8fca3852e3 arm64: cpufeature: add Neoverse-V3AE to BBML2 allow list
Neoverse-V3AE advertises support for BBML2 and is known to not raise
conflict aborts. So add it to the BBML2_NOABORT allow list.

However, just like Neoverse-V3, Neoverse-V3AE r0p0 and r0p1 suffer from
erratum #3053180, for which the workaround is to always observe
break-before-make requirements for affected revisions. Therefore only
add to the allow list from r0p2 onwards.

For more details see Software Developer Errata Notice (SDEN) document:
    Neoverse V3AE (MP172) SDEN v9.0, erratum 3053180
    https://developer.arm.com/documentation/SDEN-2615521/9-0/

Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2025-09-22 11:27:14 +01:00
Mark Rutland
0c33aa1804 arm64: errata: Apply workarounds for Neoverse-V3AE
Neoverse-V3AE is also affected by erratum #3312417, as described in its
Software Developer Errata Notice (SDEN) document:

  Neoverse V3AE (MP172) SDEN v9.0, erratum 3312417
  https://developer.arm.com/documentation/SDEN-2615521/9-0/

Enable the workaround for Neoverse-V3AE, and document this.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2025-09-22 11:27:14 +01:00
Yeoreum Yun
31d8edb535 kasan/hw-tags: introduce kasan.write_only option
Patch series "introduce kasan.write_only option in hw-tags", v8.

Hardware tag based KASAN is implemented using the Memory Tagging Extension
(MTE) feature.

MTE is built on top of the ARMv8.0 virtual address tagging TBI (Top Byte
Ignore) feature and allows software to access a 4-bit allocation tag for
each 16-byte granule in the physical address space.  A logical tag is
derived from bits 59-56 of the virtual address used for the memory access.
A CPU with MTE enabled will compare the logical tag against the
allocation tag and potentially raise an tag check fault on mismatch,
subject to system registers configuration.

Since ARMv8.9, FEAT_MTE_STORE_ONLY can be used to restrict raise of tag
check fault on store operation only.

Using this feature (FEAT_MTE_STORE_ONLY), introduce KASAN write-only mode
which restricts KASAN check write (store) operation only.  This mode omits
KASAN check for read (fetch/load) operation.  Therefore, it might be used
not only debugging purpose but also in normal environment.


This patch (of 2):

Since Armv8.9, FEATURE_MTE_STORE_ONLY feature is introduced to restrict
raise of tag check fault on store operation only.  Introduce KASAN write
only mode based on this feature.

KASAN write only mode restricts KASAN checks operation for write only and
omits the checks for fetch/read operations when accessing memory.  So it
might be used not only debugging enviroment but also normal enviroment to
check memory safty.

This features can be controlled with "kasan.write_only" arguments.  When
"kasan.write_only=on", KASAN checks write operation only otherwise KASAN
checks all operations.

This changes the MTE_STORE_ONLY feature as BOOT_CPU_FEATURE like
ARM64_MTE_ASYMM so that makes it initialise in kasan_init_hw_tags() with
other function together.

Link: https://lkml.kernel.org/r/20250916222755.466009-1-yeoreum.yun@arm.com
Link: https://lkml.kernel.org/r/20250916222755.466009-2-yeoreum.yun@arm.com
Signed-off-by: Yeoreum Yun <yeoreum.yun@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Breno Leitao <leitao@debian.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Dmitriy Vyukov <dvyukov@google.com>
Cc: D Scott Phillips <scott@os.amperecomputing.com>
Cc: Hardevsinh Palaniya <hardevsinh.palaniya@siliconsignals.io>
Cc: James Morse <james.morse@arm.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kalesh Singh <kaleshsingh@google.com>
Cc: levi.yun <yeoreum.yun@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Oliver Upton <oliver.upton@linux.dev>
Cc: Pankaj Gupta <pankaj.gupta@amd.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yang Shi <yang@os.amperecomputing.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-09-21 14:22:10 -07:00
Marc Zyngier
d9476fd356 Merge branch kvm-arm64/gic-v5-nv into kvmarm-master/next
* kvm-arm64/gic-v5-nv:
  : .
  : Add NV support to GICv5 in GICv3 emulation mode, ensuring that the v3
  : guest support is identical to that of a pure v3 platform.
  :
  : Patches courtesy of Sascha Bischoff (20250828105925.3865158-1-sascha.bischoff@arm.com)
  : .
  irqchip/gic-v5: Drop has_gcie_v3_compat from gic_kvm_info
  KVM: arm64: Use ARM64_HAS_GICV5_LEGACY for GICv5 probing
  arm64: cpucaps: Add GICv5 Legacy vCPU interface (GCIE_LEGACY) capability
  KVM: arm64: Enable nested for GICv5 host with FEAT_GCIE_LEGACY
  KVM: arm64: Don't access ICC_SRE_EL2 if GICv3 doesn't support v2 compatibility

Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-09-20 12:26:05 +01:00
Ryan Roberts
3df6979d22 arm64: mm: split linear mapping if BBML2 unsupported on secondary CPUs
The kernel linear mapping is painted in very early stage of system boot.
The cpufeature has not been finalized yet at this point. So the linear
mapping is determined by the capability of boot CPU only. If the boot
CPU supports BBML2, large block mappings will be used for linear
mapping.

But the secondary CPUs may not support BBML2, so repaint the linear
mapping if large block mapping is used and the secondary CPUs don't
support BBML2 once cpufeature is finalized on all CPUs.

If the boot CPU doesn't support BBML2 or the secondary CPUs have the
same BBML2 capability with the boot CPU, repainting the linear mapping
is not needed.

Repainting is implemented by the boot CPU, which we know supports BBML2,
so it is safe for the live mapping size to change for this CPU. The
linear map region is walked using the pagewalk API and any discovered
large leaf mappings are split to pte mappings using the existing helper
functions. Since the repainting is performed inside of a stop_machine(),
we must use GFP_ATOMIC to allocate the extra intermediate pgtables. But
since we are still early in boot, it is expected that there is plenty of
memory available so we will never need to sleep for reclaim, and so
GFP_ATOMIC is acceptable here.

The secondary CPUs are all put into a waiting area with the idmap in
TTBR0 and reserved map in TTBR1 while this is performed since they
cannot be allowed to observe any size changes on the live mappings. Some
of this infrastructure is reused from the kpti case. Specifically we
share the same flag (was __idmap_kpti_flag, now idmap_kpti_bbml2_flag)
since it means we don't have to reserve any extra pgtable memory to
idmap the extra flag.

Co-developed-by: Yang Shi <yang@os.amperecomputing.com>
Signed-off-by: Yang Shi <yang@os.amperecomputing.com>
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2025-09-19 19:13:54 +01:00
Suzuki K Poulose
d02c2e45b1 arm64: acpi: Enable ACPI CCEL support
Add support for ACPI CCEL by handling the EfiACPIMemoryNVS type memory.
As per UEFI specifications NVS memory is reserved for Firmware use even
after exiting boot services. Thus map the region as read-only.

Cc: Sami Mujawar <sami.mujawar@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@kernel.org>
Cc: Steven Price <steven.price@arm.com>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Cc: Gavin Shan <gshan@redhat.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Tested-by: Sami Mujawar <sami.mujawar@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2025-09-19 10:12:02 +01:00
Suzuki K Poulose
fa84e534c3 arm64: realm: ioremap: Allow mapping memory as encrypted
For ioremap(), so far we only checked if it was a device (RIPAS_DEV) to choose
an encrypted vs decrypted mapping. However, we may have firmware reserved memory
regions exposed to the OS (e.g., EFI Coco Secret Securityfs, ACPI CCEL).
We need to make sure that anything that is RIPAS_RAM (i.e., Guest
protected memory with RMM guarantees) are also mapped as encrypted.

Rephrasing the above, anything that is not RIPAS_EMPTY is guaranteed to be
protected by the RMM. Thus we choose encrypted mapping for anything that is not
RIPAS_EMPTY. While at it, rename the helper function

  __arm64_is_protected_mmio => arm64_rsi_is_protected

to clearly indicate that this not an arm64 generic helper, but something to do
with Realms.

Cc: Sami Mujawar <sami.mujawar@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@kernel.org>
Cc: Steven Price <steven.price@arm.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Tested-by: Sami Mujawar <sami.mujawar@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2025-09-19 10:12:01 +01:00
Yang Shi
a166563e7e arm64: mm: support large block mapping when rodata=full
When rodata=full is specified, kernel linear mapping has to be mapped at
PTE level since large page table can't be split due to break-before-make
rule on ARM64.

This resulted in a couple of problems:
  - performance degradation
  - more TLB pressure
  - memory waste for kernel page table

With FEAT_BBM level 2 support, splitting large block page table to
smaller ones doesn't need to make the page table entry invalid anymore.
This allows kernel split large block mapping on the fly.

Add kernel page table split support and use large block mapping by
default when FEAT_BBM level 2 is supported for rodata=full.  When
changing permissions for kernel linear mapping, the page table will be
split to smaller size.

The machine without FEAT_BBM level 2 will fallback to have kernel linear
mapping PTE-mapped when rodata=full.

With this we saw significant performance boost with some benchmarks and
much less memory consumption on my AmpereOne machine (192 cores, 1P)
with 256GB memory.

* Memory use after boot
Before:
MemTotal:       258988984 kB
MemFree:        254821700 kB

After:
MemTotal:       259505132 kB
MemFree:        255410264 kB

Around 500MB more memory are free to use.  The larger the machine, the
more memory saved.

* Memcached
We saw performance degradation when running Memcached benchmark with
rodata=full vs rodata=on.  Our profiling pointed to kernel TLB pressure.
With this patchset we saw ops/sec is increased by around 3.5%, P99
latency is reduced by around 9.6%.
The gain mainly came from reduced kernel TLB misses.  The kernel TLB
MPKI is reduced by 28.5%.

The benchmark data is now on par with rodata=on too.

* Disk encryption (dm-crypt) benchmark
Ran fio benchmark with the below command on a 128G ramdisk (ext4) with
disk encryption (by dm-crypt).
fio --directory=/data --random_generator=lfsr --norandommap            \
    --randrepeat 1 --status-interval=999 --rw=write --bs=4k --loops=1  \
    --ioengine=sync --iodepth=1 --numjobs=1 --fsync_on_close=1         \
    --group_reporting --thread --name=iops-test-job --eta-newline=1    \
    --size 100G

The IOPS is increased by 90% - 150% (the variance is high, but the worst
number of good case is around 90% more than the best number of bad
case). The bandwidth is increased and the avg clat is reduced
proportionally.

* Sequential file read
Read 100G file sequentially on XFS (xfs_io read with page cache
populated). The bandwidth is increased by 150%.

Co-developed-by: Ryan Roberts <ryan.roberts@arm.com>
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Yang Shi <yang@os.amperecomputing.com>
Signed-off-by: Will Deacon <will@kernel.org>
2025-09-18 21:36:37 +01:00
Yang Shi
13efe932d2 arm64: cpufeature: add AmpereOne to BBML2 allow list
AmpereOne supports BBML2 without conflict abort, add to the allow list.

Reviewed-by: Christoph Lameter (Ampere) <cl@gentwo.org>
Reviewed-by: Ryan Roberts <ryan.roberts@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Yang Shi <yang@os.amperecomputing.com>
Signed-off-by: Will Deacon <will@kernel.org>
2025-09-18 21:26:50 +01:00
Jeremy Linton
ea87c5536a arm64: probes: Fix incorrect bl/blr address and register usage
The pt_regs registers are 64-bit on arm64, and should be u64 when
manipulated. Correct this so that we aren't truncating the address
during br/blr sequences.

Fixes: efb07ac534 ("arm64: probes: Add GCS support to bl/blr/ret")
Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2025-09-18 21:06:59 +01:00
Shanker Donthineni
cc80537caa arm64: cpufeature: Add Olympus MIDR to BBML2 allow list
The NVIDIA Olympus core supports BBML2 without conflict abort. Add
its MIDR to the allow list to enable FEAT_BBM.

Signed-off-by: Shanker Donthineni <sdonthineni@nvidia.com>
Signed-off-by: Will Deacon <will@kernel.org>
2025-09-18 20:21:37 +01:00
Kuninori Morimoto
3ba8d4aa42 arm64: errata: Expand speculative SSBS workaround for Cortex-A720AE
It is same as Cortex-A720.

Link: https://lore.kernel.org/all/aMlFwbDjJ6yKuxTv@J2N7QTR9R3.cambridge.arm.com/
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Will Deacon <will@kernel.org>
2025-09-18 11:41:24 +01:00
Sascha Bischoff
7847f51189 arm64: cpucaps: Add GICv5 Legacy vCPU interface (GCIE_LEGACY) capability
Implement the GCIE_LEGACY capability as a system feature to be able to
check for support from KVM. The type is explicitly
ARM64_CPUCAP_EARLY_LOCAL_CPU_FEATURE, which means that the capability
is enabled early if all boot CPUs support it. Additionally, if this
capability is enabled during boot, it prevents late onlining of CPUs
that lack it, thereby avoiding potential mismatched configurations
which would break KVM.

Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-09-17 17:41:02 +01:00
Marc Zyngier
9664d5810e KVM: arm64: Don't access ICC_SRE_EL2 if GICv3 doesn't support v2 compatibility
We currently access ICC_SRE_EL2 at each load/put on VHE, and on each
entry/exit on nVHE. Both are quite onerous on NV, as this register
always traps.

We do this to make sure the EL1 guest doesn't flip between v2 and v3
behind our back. But all modern implementations have dropped v2,
and this is just overhead.

At the same time, the GICv5 spec has been fixed to allow access to
ICC_SRE_EL2 in legacy mode. Use this opportunity to replace the
GICv5 checks for v2 compat checks, with an ad-hoc static key.

Co-developed-by: Sascha Bischoff <sascha.bischoff@arm.com>
Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-09-17 17:40:42 +01:00
Marc Zyngier
32314d940e Merge branch kvm-arm64/dump-instr into kvmarm-master/next
* kvm-arm64/dump-instr:
  : .
  : Dump the isntruction stream on panic, just like the rest of the kernel
  : already does.
  :
  : Patches courtesy of Mostafa Saleh (20250909133631.3844423-1-smostafa@google.com)
  : .
  KVM: arm64: Map hyp text as RO and dump instr on panic
  KVM: arm64: Dump instruction on hyp panic

Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-09-17 17:30:44 +01:00
Jeremy Linton
4a601714bb arm64: uprobes: Add GCS support to uretprobes
Ret probes work by changing the value in the link register at
the probe location to return to the probe rather than the calling
routine. Thus the GCS needs to be updated with this address as well.

Since its possible to insert probes at locations where the
current value of the LR doesn't match the GCS state this needs
to be detected and handled in order to maintain the existing
no-fault behavior.

Co-developed-by: Steve Capper <steve.capper@arm.com>
Signed-off-by: Steve Capper <steve.capper@arm.com>
Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
[will: Add '__force' to gcspr casts in arch_uretprobe_hijack_return_addr()]
Signed-off-by: Will Deacon <will@kernel.org>
2025-09-16 21:34:06 +01:00
Jeremy Linton
efb07ac534 arm64: probes: Add GCS support to bl/blr/ret
The arm64 probe simulation doesn't currently have logic in place
to deal with GCS and this results in core dumps if probes are inserted
at control flow locations. Fix-up bl, blr and ret to manipulate the
shadow stack as needed.

While we manipulate and validate the shadow stack correctly, the
hardware provides additional security by only allowing GCS operations
against pages which are marked to support GCS. For writing there is
gcssttr() which enforces this, but there isn't an equivalent for
reading. This means that uprobe users should be aware that probing on
control flow instructions which require reading the shadow stack (ex:
ret) offers lower security guarantees than what is achieved without
the uprobe active.

Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2025-09-16 21:33:25 +01:00
Yury Norov (NVIDIA)
19dd484cd1 arm64/fpsimd: simplify sme_setup()
The function checks info->vq_map for emptiness right before calling
find_last_bit().

We can use the find_last_bit() output and save on bitmap_empty() call,
which is O(N).

Signed-off-by: Yury Norov (NVIDIA) <yury.norov@gmail.com>
Signed-off-by: Will Deacon <will@kernel.org>
2025-09-16 21:05:48 +01:00
Sam Edwards
b868fff5b1 arm64: mm: Represent physical memory with phys_addr_t and resource_size_t
This is a type-correctness cleanup to MMU/boot code that replaces
several instances of void * and u64 with phys_addr_t (to represent
addresses) and resource_size_t (to represent sizes) to emphasize that
the code in question concerns physical memory specifically.

The rationale for this change is to improve clarity and readability in
a few modules that handle both types (physical and virtual) of address
and differentiation is essential.

I have left u64 in cases where the address may be either physical or
virtual, where the address is exclusively virtual but used in heavy
pointer arithmetic, and in cases I may have overlooked. I do not
necessarily consider u64 the ideal type in those situations, but it
avoids breaking existing semantics in this cleanup.

This patch provably has no effect at runtime: I have verified that
.text of vmlinux is identical after this change.

Signed-off-by: Sam Edwards <CFSworks@gmail.com>
Signed-off-by: Will Deacon <will@kernel.org>
2025-09-16 20:39:49 +01:00
Sam Edwards
c56aa9a67a arm64: mm: Make map_fdt() return mapped pointer
Currently map_fdt() accepts a physical address and relies on the caller
to keep using the same value after mapping, since the implementation
happens to install an identity mapping. This obscures the fact that the
usable pointer is defined by the mapping, not by the input value. Since
the mapping determines pointer validity, it is more natural to produce
the pointer at mapping time.

Change map_fdt() to return a void * pointing to the mapped FDT. This
clarifies the data flow, removes the implicit identity assumption, and
prepares for making map_fdt() accept a phys_addr_t in a follow-up
change.

Signed-off-by: Sam Edwards <CFSworks@gmail.com>
Signed-off-by: Will Deacon <will@kernel.org>
2025-09-16 20:39:49 +01:00
Sam Edwards
030b3ffbda arm64: mm: Cast start/end markers to char *, not u64
There are a few memset() calls in map_kernel.c that cast marker-symbol
addresses to u64 in order to perform pointer subtraction (range size
computation).

Cast them with (char *) instead, aligning with idiomatic C pointer
arithmetic.

This patch provably has no effect at runtime: I have verified that
.text of vmlinux is identical after this change.

Signed-off-by: Sam Edwards <CFSworks@gmail.com>
Signed-off-by: Will Deacon <will@kernel.org>
2025-09-16 20:39:49 +01:00
Jeremy Linton
47687aa4d9 arm64: probes: Break ret out from bl/blr
Prepare for GCS by breaking RET out into its own function, where
it makes more sense to encapsulate the new behavior independent
from the branch instructions.

Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2025-09-16 20:31:44 +01:00
Mark Brown
220928e52c arm64/hwcap: Add hwcap for FEAT_LSFE
FEAT_LSFE (Large System Float Extension), providing atomic floating point
memory operations, is optional from v9.5. This feature adds no new
architectural stare and we have no immediate use for it in the kernel so
simply provide a hwcap for it to support discovery by userspace.

Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
2025-09-16 19:55:11 +01:00
Mostafa Saleh
92b7624fe0 KVM: arm64: Dump instruction on hyp panic
Similar to the kernel panic, where the instruction code is printed,
we can do the same for hypervisor panics.

This patch does that only in case of “CONFIG_NVHE_EL2_DEBUG” or nvhe.

The next patch adds support for pKVM.

Also, remove the hardcoded argument dump_kernel_instr().

Signed-off-by: Mostafa Saleh <smostafa@google.com>
Tested-by: Kunwu Chan <chentao@kylinos.cn>
Reviewed-by: Kunwu Chan <chentao@kylinos.cn>
Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-09-15 13:04:22 +01:00
Jinjie Ruan
b3cf07851b arm64: entry: Switch to generic IRQ entry
Currently, x86, Riscv and Loongarch use the generic entry code, which
makes maintainer's work easier and code more elegant. Start converting
arm64 to use the generic entry infrastructure from kernel/entry/* by
switching it to generic IRQ entry, which removes 100+ lines of duplicate
code. arm64 will completely switch to generic entry in a later series.

The changes are below:
 - Remove *enter_from/exit_to_kernel_mode(), and wrap with generic
   irqentry_enter/exit() as their code and functionality are almost
   identical.

 - Define ARCH_EXIT_TO_USER_MODE_WORK and implement
   arch_exit_to_user_mode_work() to check arm64-specific thread flags
   "_TIF_MTE_ASYNC_FAULT" and "_TIF_FOREIGN_FPSTATE".
   So also remove *enter_from/exit_to_user_mode(), and wrap with
   generic enter_from/exit_to_user_mode() because they are
   exactly the same.

 - Remove arm64_enter/exit_nmi() and use generic irqentry_nmi_enter/exit()
   because they're exactly the same, so the temporary arm64 version
   irqentry_state can also be removed.

 - Remove PREEMPT_DYNAMIC code, as generic irqentry_exit_cond_resched()
   has the same functionality.

 - Implement arch_irqentry_exit_need_resched() with
   arm64_preempt_schedule_irq() for arm64 which will allow arm64 to do
   its architecture specific checks.

Tested-by: Ada Couprie Diaz <ada.coupriediaz@arm.com>
Suggested-by: Ada Couprie Diaz <ada.coupriediaz@arm.com>
Suggested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2025-09-11 15:55:35 +01:00
Jinjie Ruan
99eb057ccd arm64: entry: Move arm64_preempt_schedule_irq() into __exit_to_kernel_mode()
The arm64 entry code only preempts a kernel context upon a return from
a regular IRQ exception. The generic entry code may preempt a kernel
context for any exception return where irqentry_exit() is used, and so
may preempt other exceptions such as faults.

In preparation for moving arm64 over to the generic entry code, align
arm64 with the generic behaviour by calling
arm64_preempt_schedule_irq() from exit_to_kernel_mode(). To make this
possible, arm64_preempt_schedule_irq()
and dynamic/raw_irqentry_exit_cond_resched() are moved earlier in
the file, with no changes.

As Mark pointed out, this change will have the following 2 key impact:

- " We'll preempt even without taking a "real" interrupt. That
    shouldn't result in preemption that wasn't possible before,
    but it does change the probability of preempting at certain points,
    and might have a performance impact, so probably warrants a
    benchmark."

- " We will not preempt when taking interrupts from a region of kernel
    code where IRQs are enabled but RCU is not watching, matching the
    behaviour of the generic entry code.

    This has the potential to introduce livelock if we can ever have a
    screaming interrupt in such a region, so we'll need to go figure out
    whether that's actually a problem.

    Having this as a separate patch will make it easier to test/bisect
    for that specifically."

Reviewed-by: Ada Couprie Diaz <ada.coupriediaz@arm.com>
Suggested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2025-09-11 15:55:35 +01:00
Jinjie Ruan
64f4b8b15f arm64: entry: Refactor preempt_schedule_irq() check code
To align the structure of the code with irqentry_exit_cond_resched()
from the generic entry code, hoist the need_irq_preemption()
and IS_ENABLED() check earlier. And different preemption check functions
are defined based on whether dynamic preemption is enabled.

Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Reviewed-by: Ada Couprie Diaz <ada.coupriediaz@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2025-09-11 15:55:34 +01:00
Jinjie Ruan
c74c44c6ae arm64: entry: Use preempt_count() and need_resched() helper
The generic entry code uses preempt_count() and need_resched() helpers to
check if it should do preempt_schedule_irq(). Currently, arm64 use its own
check logic, that is "READ_ONCE(current_thread_info()->preempt_count == 0",
which is equivalent to "preempt_count() == 0 && need_resched()".

In preparation for moving arm64 over to the generic entry code, use
these helpers to replace arm64's own code and move it ahead.

No functional changes.

Reviewed-by: Ada Couprie Diaz <ada.coupriediaz@arm.com>
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2025-09-11 15:55:34 +01:00
Jinjie Ruan
77c1953946 arm64: entry: Rework arm64_preempt_schedule_irq()
The generic entry code has the form:

| raw_irqentry_exit_cond_resched()
| {
| 	if (!preempt_count()) {
| 		...
| 		if (need_resched())
| 			preempt_schedule_irq();
| 	}
| }

In preparation for moving arm64 over to the generic entry code, align
the structure of the arm64 code with raw_irqentry_exit_cond_resched() from
the generic entry code.

Reviewed-by: Ada Couprie Diaz <ada.coupriediaz@arm.com>
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2025-09-11 15:55:34 +01:00
Jinjie Ruan
ee776d68ba arm64: entry: Refactor the entry and exit for exceptions from EL1
The generic entry code uses irqentry_state_t to track lockdep and RCU
state across exception entry and return. For historical reasons, arm64
embeds similar fields within its pt_regs structure.

In preparation for moving arm64 over to the generic entry code, pull
these fields out of arm64's pt_regs, and use a separate structure,
matching the style of the generic entry code.

No functional changes.

Acked-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Ada Couprie Diaz <ada.coupriediaz@arm.com>
Suggested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2025-09-11 15:55:34 +01:00
Jinjie Ruan
788b8f6af6 arm64: ptrace: Replace interrupts_enabled() with regs_irqs_disabled()
The generic entry code expects architecture code to provide
regs_irqs_disabled(regs) function, but arm64 does not have this and
provides interrupts_enabled(regs), which has the opposite polarity.

In preparation for moving arm64 over to the generic entry code,
relace arm64's interrupts_enabled() with regs_irqs_disabled() and
update its callers under arch/arm64.

For the moment, a definition of interrupts_enabled() is provided for
the GICv3 driver. Once arch/arm implement regs_irqs_disabled(), this
can be removed.

Delete the fast_interrupts_enabled() macro as it is unused and we
don't want any new users to show up.

No functional changes.

Reviewed-by: Ada Couprie Diaz <ada.coupriediaz@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Suggested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2025-09-11 15:55:34 +01:00
Linus Torvalds
4f553c1e2c 20 hotfixes. 15 are cc:stable and the remainder address post-6.16 issues
or aren't considered necessary for -stable kernels.  14 of these fixes are
 for MM.
 
 This includes
 
 - a 3-patch kexec series from Breno that fixes a recently introduced
   use-uninitialized bug,
 
 - e 2-patch DAMON series from Quanmin Yan that avoids div-by-zero
   crashes which can occur if the operator uses poorly-chosen insmod
   parameters.
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Merge tag 'mm-hotfixes-stable-2025-09-10-20-00' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull misc fixes from Andrew Morton:
 "20 hotfixes. 15 are cc:stable and the remainder address post-6.16
  issues or aren't considered necessary for -stable kernels. 14 of these
  fixes are for MM.

  This includes

   - kexec fixes from Breno for a recently introduced
     use-uninitialized bug

   - DAMON fixes from Quanmin Yan to avoid div-by-zero crashes
     which can occur if the operator uses poorly-chosen insmod
     parameters

   and misc singleton fixes"

* tag 'mm-hotfixes-stable-2025-09-10-20-00' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
  MAINTAINERS: add tree entry to numa memblocks and emulation block
  mm/damon/sysfs: fix use-after-free in state_show()
  proc: fix type confusion in pde_set_flags()
  compiler-clang.h: define __SANITIZE_*__ macros only when undefined
  mm/vmalloc, mm/kasan: respect gfp mask in kasan_populate_vmalloc()
  ocfs2: fix recursive semaphore deadlock in fiemap call
  mm/memory-failure: fix VM_BUG_ON_PAGE(PagePoisoned(page)) when unpoison memory
  mm/mremap: fix regression in vrm->new_addr check
  percpu: fix race on alloc failed warning limit
  mm/memory-failure: fix redundant updates for already poisoned pages
  s390: kexec: initialize kexec_buf struct
  riscv: kexec: initialize kexec_buf struct
  arm64: kexec: initialize kexec_buf struct in load_other_segments()
  mm/damon/reclaim: avoid divide-by-zero in damon_reclaim_apply_parameters()
  mm/damon/lru_sort: avoid divide-by-zero in damon_lru_sort_apply_parameters()
  mm/damon/core: set quota->charged_from to jiffies at first charge window
  mm/hugetlb: add missing hugetlb_lock in __unmap_hugepage_range()
  init/main.c: fix boot time tracing crash
  mm/memory_hotplug: fix hwpoisoned large folio handling in do_migrate_range()
  mm/khugepaged: fix the address passed to notifier on testing young
2025-09-10 21:19:34 -07:00
Thomas Weißschuh
281817dffe arm64: vdso32: Respect -Werror from kbuild
The compiler flags for the compat vDSO are built manually as they are not
compatible with the ones from kbuild. CONFIG_WERROR is not respected.

Explicitly inherit -Werror from kbuild.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Signed-off-by: Will Deacon <will@kernel.org>
2025-09-08 16:21:40 +01:00
Thomas Weißschuh
80c4e19489 arm64: vdso32: Stop suppressing warnings
These warnings don't seem to trigger anymore. Probably due to the
introduction of the vdso/ header namespace. Nowadays these suppression
only hide real problems.

Re-enable the warnings.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Signed-off-by: Will Deacon <will@kernel.org>
2025-09-08 16:21:40 +01:00
Linus Torvalds
e5d5d23319 arm64 fixes:
- Incorrect __BITS_PER_LONG as 64 when compiling the compat vDSO
 
  - Unreachable PLT for ftrace_caller() in a module's .init.text
    following past reworking of the module VA range selection
 
  - Memory leak in the ACPI iort_rmr_alloc_sids() after a failed
    krealloc_array()
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Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 fixes from Catalin Marinas:

 - Incorrect __BITS_PER_LONG as 64 when compiling the compat vDSO

 - Unreachable PLT for ftrace_caller() in a module's .init.text
   following past reworking of the module VA range selection

 - Memory leak in the ACPI iort_rmr_alloc_sids() after a failed
   krealloc_array()

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: ftrace: fix unreachable PLT for ftrace_caller in init_module with CONFIG_DYNAMIC_FTRACE
  ACPI/IORT: Fix memory leak in iort_rmr_alloc_sids()
  arm64: uapi: Provide correct __BITS_PER_LONG for the compat vDSO
2025-09-05 13:11:10 -07:00
panfan
a7ed7b9d0e arm64: ftrace: fix unreachable PLT for ftrace_caller in init_module with CONFIG_DYNAMIC_FTRACE
On arm64, it has been possible for a module's sections to be placed more
than 128M away from each other since commit:

  commit 3e35d303ab ("arm64: module: rework module VA range selection")

Due to this, an ftrace callsite in a module's .init.text section can be
out of branch range for the module's ftrace PLT entry (in the module's
.text section). Any attempt to enable tracing of that callsite will
result in a BRK being patched into the callsite, resulting in a fatal
exception when the callsite is later executed.

Fix this by adding an additional trampoline for .init.text, which will
be within range.

No additional trampolines are necessary due to the way a given
module's executable sections are packed together. Any executable
section beginning with ".init" will be placed in MOD_INIT_TEXT,
and any other executable section, including those beginning with ".exit",
 will be placed in MOD_TEXT.

Fixes: 3e35d303ab ("arm64: module: rework module VA range selection")
Cc: <stable@vger.kernel.org> # 6.5.x
Signed-off-by: panfan <panfan@qti.qualcomm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20250905032236.3220885-1-panfan@qti.qualcomm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2025-09-05 16:56:20 +01:00
Thomas Weißschuh
7d298d25ce vdso: Move ENABLE_COMPAT_VDSO from core to arm64
The ENABLE_COMAPT_VDSO symbol is only used by arm64 and only for the
time-related functionality. There should be no new users, so it doesn't
need to be in the generic vDSO code.

Move the logic into arm64 architecture-specific code and replace the
explicit define by the standard '#ifdef __aarch64__'.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/all/20250826-vdso-cleanups-v1-3-d9b65750e49f@linutronix.de
2025-09-04 11:23:49 +02:00
Breno Leitao
04d3cd4370 arm64: kexec: initialize kexec_buf struct in load_other_segments()
Patch series "kexec: Fix invalid field access".

The kexec_buf structure was previously declared without initialization. 
commit bf454ec31a ("kexec_file: allow to place kexec_buf randomly")
added a field that is always read but not consistently populated by all
architectures.  This un-initialized field will contain garbage.

This is also triggering a UBSAN warning when the uninitialized data was
accessed:

	------------[ cut here ]------------
	UBSAN: invalid-load in ./include/linux/kexec.h:210:10
	load of value 252 is not a valid value for type '_Bool'

Zero-initializing kexec_buf at declaration ensures all fields are cleanly
set, preventing future instances of uninitialized memory being used.

An initial fix was already landed for arm64[0], and this patchset fixes
the problem on the remaining arm64 code and on riscv, as raised by Mark.

Discussions about this problem could be found at[1][2].


This patch (of 3):

The kexec_buf structure was previously declared without initialization.
commit bf454ec31a ("kexec_file: allow to place kexec_buf randomly")
added a field that is always read but not consistently populated by all
architectures. This un-initialized field will contain garbage.

This is also triggering a UBSAN warning when the uninitialized data was
accessed:

	------------[ cut here ]------------
	UBSAN: invalid-load in ./include/linux/kexec.h:210:10
	load of value 252 is not a valid value for type '_Bool'

Zero-initializing kexec_buf at declaration ensures all fields are
cleanly set, preventing future instances of uninitialized memory being
used.

Link: https://lkml.kernel.org/r/20250827-kbuf_all-v1-0-1df9882bb01a@debian.org
Link: https://lkml.kernel.org/r/20250827-kbuf_all-v1-1-1df9882bb01a@debian.org
Link: https://lore.kernel.org/all/20250826180742.f2471131255ec1c43683ea07@linux-foundation.org/ [0]
Link: https://lore.kernel.org/all/oninomspajhxp4omtdapxnckxydbk2nzmrix7rggmpukpnzadw@c67o7njgdgm3/ [1]
Link: https://lore.kernel.org/all/20250826-akpm-v1-1-3c831f0e3799@debian.org/ [2]
Fixes: bf454ec31a ("kexec_file: allow to place kexec_buf randomly")
Signed-off-by: Breno Leitao <leitao@debian.org>
Acked-by: Baoquan He <bhe@redhat.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Alexandre Ghiti <alex@ghiti.fr>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Coiby Xu <coxu@redhat.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-09-03 17:10:37 -07:00
Simon Schuster
bbc46b23af arch: copy_thread: pass clone_flags as u64
With the introduction of clone3 in commit 7f192e3cd3 ("fork: add
clone3") the effective bit width of clone_flags on all architectures was
increased from 32-bit to 64-bit, with a new type of u64 for the flags.
However, for most consumers of clone_flags the interface was not
changed from the previous type of unsigned long.

While this works fine as long as none of the new 64-bit flag bits
(CLONE_CLEAR_SIGHAND and CLONE_INTO_CGROUP) are evaluated, this is still
undesirable in terms of the principle of least surprise.

Thus, this commit fixes all relevant interfaces of the copy_thread
function that is called from copy_process to consistently pass
clone_flags as u64, so that no truncation to 32-bit integers occurs on
32-bit architectures.

Signed-off-by: Simon Schuster <schuster.simon@siemens-energy.com>
Link: https://lore.kernel.org/20250901-nios2-implement-clone3-v2-3-53fcf5577d57@siemens-energy.com
Fixes: c5febea095 ("fork: Pass struct kernel_clone_args into copy_thread")
Acked-by: Guo Ren (Alibaba Damo Academy) <guoren@kernel.org>
Acked-by: Andreas Larsson <andreas@gaisler.com> # sparc
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> # m68k
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-09-01 15:31:34 +02:00
Linus Torvalds
c8bc81a52d Two arm64 fixes:
- CFI failure due to kpti_ng_pgd_alloc() signature mismatch
 
 - Underallocation bug in the SVE ptrace kselftest
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Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 fixes from Catalin Marinas:

 - CFI failure due to kpti_ng_pgd_alloc() signature mismatch

 - Underallocation bug in the SVE ptrace kselftest

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  kselftest/arm64: Don't open code SVE_PT_SIZE() in fp-ptrace
  arm64: mm: Fix CFI failure due to kpti_ng_pgd_alloc function signature
2025-08-30 10:43:53 -07:00
Kees Cook
ceca927c86 arm64: mm: Fix CFI failure due to kpti_ng_pgd_alloc function signature
Seen during KPTI initialization:

  CFI failure at create_kpti_ng_temp_pgd+0x124/0xce8 (target: kpti_ng_pgd_alloc+0x0/0x14; expected type: 0xd61b88b6)

The call site is alloc_init_pud() at arch/arm64/mm/mmu.c:

  pud_phys = pgtable_alloc(TABLE_PUD);

alloc_init_pud() has the prototype:

  static void alloc_init_pud(p4d_t *p4dp, unsigned long addr, unsigned long end,
                             phys_addr_t phys, pgprot_t prot,
                             phys_addr_t (*pgtable_alloc)(enum pgtable_type),
                             int flags)

where the pgtable_alloc() prototype is declared.

The target (kpti_ng_pgd_alloc) is used in arch/arm64/kernel/cpufeature.c:

  create_kpti_ng_temp_pgd(kpti_ng_temp_pgd, __pa(alloc), KPTI_NG_TEMP_VA,
                          PAGE_SIZE, PAGE_KERNEL, kpti_ng_pgd_alloc, 0);

which is an alias for __create_pgd_mapping_locked() with prototype:

  extern __alias(__create_pgd_mapping_locked)
  void create_kpti_ng_temp_pgd(pgd_t *pgdir, phys_addr_t phys,
                               unsigned long virt,
                               phys_addr_t size, pgprot_t prot,
                               phys_addr_t (*pgtable_alloc)(enum pgtable_type),
                               int flags);

__create_pgd_mapping_locked() passes the function pointer down:

  __create_pgd_mapping_locked() -> alloc_init_p4d() -> alloc_init_pud()

But the target function (kpti_ng_pgd_alloc) has the wrong signature:

  static phys_addr_t __init kpti_ng_pgd_alloc(int shift);

The "int" should be "enum pgtable_type".

To make "enum pgtable_type" available to cpufeature.c, move
enum pgtable_type definition from arch/arm64/mm/mmu.c to
arch/arm64/include/asm/mmu.h.

Adjust kpti_ng_pgd_alloc to use "enum pgtable_type" instead of "int".
The function behavior remains identical (parameter is unused).

Fixes: c64f46ee13 ("arm64: mm: use enum to identify pgtable level instead of *_SHIFT")
Cc: <stable@vger.kernel.org> # 6.16.x
Signed-off-by: Kees Cook <kees@kernel.org>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20250829190721.it.373-kees@kernel.org
Reviewed-by: Ryan Roberts <ryan.roberts@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2025-08-30 11:30:06 +01:00
Paolo Bonzini
42a0305ab1 KVM/arm64 changes for 6.17, take #2
- Correctly handle 'invariant' system registers for protected VMs
 
  - Improved handling of VNCR data aborts, including external aborts
 
  - Fixes for handling of FEAT_RAS for NV guests, providing a sane
    fault context during SEA injection and preventing the use of
    RASv1p1 fault injection hardware
 
  - Ensure that page table destruction when a VM is destroyed gives an
    opportunity to reschedule
 
  - Large fix to KVM's infrastructure for managing guest context loaded
    on the CPU, addressing issues where the output of AT emulation
    doesn't get reflected to the guest
 
  - Fix AT S12 emulation to actually perform stage-2 translation when
    necessary
 
  - Avoid attempting vLPI irqbypass when GICv4 has been explicitly
    disabled for a VM
 
  - Minor KVM + selftest fixes
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Merge tag 'kvmarm-fixes-6.17-1' of https://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm64 changes for 6.17, take #2

 - Correctly handle 'invariant' system registers for protected VMs

 - Improved handling of VNCR data aborts, including external aborts

 - Fixes for handling of FEAT_RAS for NV guests, providing a sane
   fault context during SEA injection and preventing the use of
   RASv1p1 fault injection hardware

 - Ensure that page table destruction when a VM is destroyed gives an
   opportunity to reschedule

 - Large fix to KVM's infrastructure for managing guest context loaded
   on the CPU, addressing issues where the output of AT emulation
   doesn't get reflected to the guest

 - Fix AT S12 emulation to actually perform stage-2 translation when
   necessary

 - Avoid attempting vLPI irqbypass when GICv4 has been explicitly
   disabled for a VM

 - Minor KVM + selftest fixes
2025-08-29 12:57:31 -04:00
Marc Zyngier
8049164653 arm64: Add capability denoting FEAT_RASv1p1
Detecting FEAT_RASv1p1 is rather complicated, as there are two
ways for the architecture to advertise the same thing (always a
delight...).

Add a capability that will advertise this in a synthetic way to
the rest of the kernel.

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Link: https://lore.kernel.org/r/20250817202158.395078-2-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-08-21 16:28:46 -07:00
Linus Torvalds
63eb28bb14 ARM:
- Host driver for GICv5, the next generation interrupt controller for
   arm64, including support for interrupt routing, MSIs, interrupt
   translation and wired interrupts.
 
 - Use FEAT_GCIE_LEGACY on GICv5 systems to virtualize GICv3 VMs on
   GICv5 hardware, leveraging the legacy VGIC interface.
 
 - Userspace control of the 'nASSGIcap' GICv3 feature, allowing
   userspace to disable support for SGIs w/o an active state on hardware
   that previously advertised it unconditionally.
 
 - Map supporting endpoints with cacheable memory attributes on systems
   with FEAT_S2FWB and DIC where KVM no longer needs to perform cache
   maintenance on the address range.
 
 - Nested support for FEAT_RAS and FEAT_DoubleFault2, allowing the guest
   hypervisor to inject external aborts into an L2 VM and take traps of
   masked external aborts to the hypervisor.
 
 - Convert more system register sanitization to the config-driven
   implementation.
 
 - Fixes to the visibility of EL2 registers, namely making VGICv3 system
   registers accessible through the VGIC device instead of the ONE_REG
   vCPU ioctls.
 
 - Various cleanups and minor fixes.
 
 LoongArch:
 
 - Add stat information for in-kernel irqchip
 
 - Add tracepoints for CPUCFG and CSR emulation exits
 
 - Enhance in-kernel irqchip emulation
 
 - Various cleanups.
 
 RISC-V:
 
 - Enable ring-based dirty memory tracking
 
 - Improve perf kvm stat to report interrupt events
 
 - Delegate illegal instruction trap to VS-mode
 
 - MMU improvements related to upcoming nested virtualization
 
 s390x
 
 - Fixes
 
 x86:
 
 - Add CONFIG_KVM_IOAPIC for x86 to allow disabling support for I/O APIC,
   PIC, and PIT emulation at compile time.
 
 - Share device posted IRQ code between SVM and VMX and
   harden it against bugs and runtime errors.
 
 - Use vcpu_idx, not vcpu_id, for GA log tag/metadata, to make lookups O(1)
   instead of O(n).
 
 - For MMIO stale data mitigation, track whether or not a vCPU has access to
   (host) MMIO based on whether the page tables have MMIO pfns mapped; using
   VFIO is prone to false negatives
 
 - Rework the MSR interception code so that the SVM and VMX APIs are more or
   less identical.
 
 - Recalculate all MSR intercepts from scratch on MSR filter changes,
   instead of maintaining shadow bitmaps.
 
 - Advertise support for LKGS (Load Kernel GS base), a new instruction
   that's loosely related to FRED, but is supported and enumerated
   independently.
 
 - Fix a user-triggerable WARN that syzkaller found by setting the vCPU
   in INIT_RECEIVED state (aka wait-for-SIPI), and then putting the vCPU
   into VMX Root Mode (post-VMXON).  Trying to detect every possible path
   leading to architecturally forbidden states is hard and even risks
   breaking userspace (if it goes from valid to valid state but passes
   through invalid states), so just wait until KVM_RUN to detect that
   the vCPU state isn't allowed.
 
 - Add KVM_X86_DISABLE_EXITS_APERFMPERF to allow disabling interception of
   APERF/MPERF reads, so that a "properly" configured VM can access
   APERF/MPERF.  This has many caveats (APERF/MPERF cannot be zeroed
   on vCPU creation or saved/restored on suspend and resume, or preserved
   over thread migration let alone VM migration) but can be useful whenever
   you're interested in letting Linux guests see the effective physical CPU
   frequency in /proc/cpuinfo.
 
 - Reject KVM_SET_TSC_KHZ for vm file descriptors if vCPUs have been
   created, as there's no known use case for changing the default
   frequency for other VM types and it goes counter to the very reason
   why the ioctl was added to the vm file descriptor.  And also, there
   would be no way to make it work for confidential VMs with a "secure"
   TSC, so kill two birds with one stone.
 
 - Dynamically allocation the shadow MMU's hashed page list, and defer
   allocating the hashed list until it's actually needed (the TDP MMU
   doesn't use the list).
 
 - Extract many of KVM's helpers for accessing architectural local APIC
   state to common x86 so that they can be shared by guest-side code for
   Secure AVIC.
 
 - Various cleanups and fixes.
 
 x86 (Intel):
 
 - Preserve the host's DEBUGCTL.FREEZE_IN_SMM when running the guest.
   Failure to honor FREEZE_IN_SMM can leak host state into guests.
 
 - Explicitly check vmcs12.GUEST_DEBUGCTL on nested VM-Enter to prevent
   L1 from running L2 with features that KVM doesn't support, e.g. BTF.
 
 x86 (AMD):
 
 - WARN and reject loading kvm-amd.ko instead of panicking the kernel if the
   nested SVM MSRPM offsets tracker can't handle an MSR (which is pretty
   much a static condition and therefore should never happen, but still).
 
 - Fix a variety of flaws and bugs in the AVIC device posted IRQ code.
 
 - Inhibit AVIC if a vCPU's ID is too big (relative to what hardware
   supports) instead of rejecting vCPU creation.
 
 - Extend enable_ipiv module param support to SVM, by simply leaving
   IsRunning clear in the vCPU's physical ID table entry.
 
 - Disable IPI virtualization, via enable_ipiv, if the CPU is affected by
   erratum #1235, to allow (safely) enabling AVIC on such CPUs.
 
 - Request GA Log interrupts if and only if the target vCPU is blocking,
   i.e. only if KVM needs a notification in order to wake the vCPU.
 
 - Intercept SPEC_CTRL on AMD if the MSR shouldn't exist according to the
   vCPU's CPUID model.
 
 - Accept any SNP policy that is accepted by the firmware with respect to
   SMT and single-socket restrictions.  An incompatible policy doesn't put
   the kernel at risk in any way, so there's no reason for KVM to care.
 
 - Drop a superfluous WBINVD (on all CPUs!) when destroying a VM and
   use WBNOINVD instead of WBINVD when possible for SEV cache maintenance.
 
 - When reclaiming memory from an SEV guest, only do cache flushes on CPUs
   that have ever run a vCPU for the guest, i.e. don't flush the caches for
   CPUs that can't possibly have cache lines with dirty, encrypted data.
 
 Generic:
 
 - Rework irqbypass to track/match producers and consumers via an xarray
   instead of a linked list.  Using a linked list leads to O(n^2) insertion
   times, which is hugely problematic for use cases that create large
   numbers of VMs.  Such use cases typically don't actually use irqbypass,
   but eliminating the pointless registration is a future problem to
   solve as it likely requires new uAPI.
 
 - Track irqbypass's "token" as "struct eventfd_ctx *" instead of a "void *",
   to avoid making a simple concept unnecessarily difficult to understand.
 
 - Decouple device posted IRQs from VFIO device assignment, as binding a VM
   to a VFIO group is not a requirement for enabling device posted IRQs.
 
 - Clean up and document/comment the irqfd assignment code.
 
 - Disallow binding multiple irqfds to an eventfd with a priority waiter,
   i.e.  ensure an eventfd is bound to at most one irqfd through the entire
   host, and add a selftest to verify eventfd:irqfd bindings are globally
   unique.
 
 - Add a tracepoint for KVM_SET_MEMORY_ATTRIBUTES to help debug issues
   related to private <=> shared memory conversions.
 
 - Drop guest_memfd's .getattr() implementation as the VFS layer will call
   generic_fillattr() if inode_operations.getattr is NULL.
 
 - Fix issues with dirty ring harvesting where KVM doesn't bound the
   processing of entries in any way, which allows userspace to keep KVM
   in a tight loop indefinitely.
 
 - Kill off kvm_arch_{start,end}_assignment() and x86's associated tracking,
   now that KVM no longer uses assigned_device_count as a heuristic for
   either irqbypass usage or MDS mitigation.
 
 Selftests:
 
 - Fix a comment typo.
 
 - Verify KVM is loaded when getting any KVM module param so that attempting
   to run a selftest without kvm.ko loaded results in a SKIP message about
   KVM not being loaded/enabled (versus some random parameter not existing).
 
 - Skip tests that hit EACCES when attempting to access a file, and rpint
   a "Root required?" help message.  In most cases, the test just needs to
   be run with elevated permissions.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull kvm updates from Paolo Bonzini:
 "ARM:

   - Host driver for GICv5, the next generation interrupt controller for
     arm64, including support for interrupt routing, MSIs, interrupt
     translation and wired interrupts

   - Use FEAT_GCIE_LEGACY on GICv5 systems to virtualize GICv3 VMs on
     GICv5 hardware, leveraging the legacy VGIC interface

   - Userspace control of the 'nASSGIcap' GICv3 feature, allowing
     userspace to disable support for SGIs w/o an active state on
     hardware that previously advertised it unconditionally

   - Map supporting endpoints with cacheable memory attributes on
     systems with FEAT_S2FWB and DIC where KVM no longer needs to
     perform cache maintenance on the address range

   - Nested support for FEAT_RAS and FEAT_DoubleFault2, allowing the
     guest hypervisor to inject external aborts into an L2 VM and take
     traps of masked external aborts to the hypervisor

   - Convert more system register sanitization to the config-driven
     implementation

   - Fixes to the visibility of EL2 registers, namely making VGICv3
     system registers accessible through the VGIC device instead of the
     ONE_REG vCPU ioctls

   - Various cleanups and minor fixes

  LoongArch:

   - Add stat information for in-kernel irqchip

   - Add tracepoints for CPUCFG and CSR emulation exits

   - Enhance in-kernel irqchip emulation

   - Various cleanups

  RISC-V:

   - Enable ring-based dirty memory tracking

   - Improve perf kvm stat to report interrupt events

   - Delegate illegal instruction trap to VS-mode

   - MMU improvements related to upcoming nested virtualization

  s390x

   - Fixes

  x86:

   - Add CONFIG_KVM_IOAPIC for x86 to allow disabling support for I/O
     APIC, PIC, and PIT emulation at compile time

   - Share device posted IRQ code between SVM and VMX and harden it
     against bugs and runtime errors

   - Use vcpu_idx, not vcpu_id, for GA log tag/metadata, to make lookups
     O(1) instead of O(n)

   - For MMIO stale data mitigation, track whether or not a vCPU has
     access to (host) MMIO based on whether the page tables have MMIO
     pfns mapped; using VFIO is prone to false negatives

   - Rework the MSR interception code so that the SVM and VMX APIs are
     more or less identical

   - Recalculate all MSR intercepts from scratch on MSR filter changes,
     instead of maintaining shadow bitmaps

   - Advertise support for LKGS (Load Kernel GS base), a new instruction
     that's loosely related to FRED, but is supported and enumerated
     independently

   - Fix a user-triggerable WARN that syzkaller found by setting the
     vCPU in INIT_RECEIVED state (aka wait-for-SIPI), and then putting
     the vCPU into VMX Root Mode (post-VMXON). Trying to detect every
     possible path leading to architecturally forbidden states is hard
     and even risks breaking userspace (if it goes from valid to valid
     state but passes through invalid states), so just wait until
     KVM_RUN to detect that the vCPU state isn't allowed

   - Add KVM_X86_DISABLE_EXITS_APERFMPERF to allow disabling
     interception of APERF/MPERF reads, so that a "properly" configured
     VM can access APERF/MPERF. This has many caveats (APERF/MPERF
     cannot be zeroed on vCPU creation or saved/restored on suspend and
     resume, or preserved over thread migration let alone VM migration)
     but can be useful whenever you're interested in letting Linux
     guests see the effective physical CPU frequency in /proc/cpuinfo

   - Reject KVM_SET_TSC_KHZ for vm file descriptors if vCPUs have been
     created, as there's no known use case for changing the default
     frequency for other VM types and it goes counter to the very reason
     why the ioctl was added to the vm file descriptor. And also, there
     would be no way to make it work for confidential VMs with a
     "secure" TSC, so kill two birds with one stone

   - Dynamically allocation the shadow MMU's hashed page list, and defer
     allocating the hashed list until it's actually needed (the TDP MMU
     doesn't use the list)

   - Extract many of KVM's helpers for accessing architectural local
     APIC state to common x86 so that they can be shared by guest-side
     code for Secure AVIC

   - Various cleanups and fixes

  x86 (Intel):

   - Preserve the host's DEBUGCTL.FREEZE_IN_SMM when running the guest.
     Failure to honor FREEZE_IN_SMM can leak host state into guests

   - Explicitly check vmcs12.GUEST_DEBUGCTL on nested VM-Enter to
     prevent L1 from running L2 with features that KVM doesn't support,
     e.g. BTF

  x86 (AMD):

   - WARN and reject loading kvm-amd.ko instead of panicking the kernel
     if the nested SVM MSRPM offsets tracker can't handle an MSR (which
     is pretty much a static condition and therefore should never
     happen, but still)

   - Fix a variety of flaws and bugs in the AVIC device posted IRQ code

   - Inhibit AVIC if a vCPU's ID is too big (relative to what hardware
     supports) instead of rejecting vCPU creation

   - Extend enable_ipiv module param support to SVM, by simply leaving
     IsRunning clear in the vCPU's physical ID table entry

   - Disable IPI virtualization, via enable_ipiv, if the CPU is affected
     by erratum #1235, to allow (safely) enabling AVIC on such CPUs

   - Request GA Log interrupts if and only if the target vCPU is
     blocking, i.e. only if KVM needs a notification in order to wake
     the vCPU

   - Intercept SPEC_CTRL on AMD if the MSR shouldn't exist according to
     the vCPU's CPUID model

   - Accept any SNP policy that is accepted by the firmware with respect
     to SMT and single-socket restrictions. An incompatible policy
     doesn't put the kernel at risk in any way, so there's no reason for
     KVM to care

   - Drop a superfluous WBINVD (on all CPUs!) when destroying a VM and
     use WBNOINVD instead of WBINVD when possible for SEV cache
     maintenance

   - When reclaiming memory from an SEV guest, only do cache flushes on
     CPUs that have ever run a vCPU for the guest, i.e. don't flush the
     caches for CPUs that can't possibly have cache lines with dirty,
     encrypted data

  Generic:

   - Rework irqbypass to track/match producers and consumers via an
     xarray instead of a linked list. Using a linked list leads to
     O(n^2) insertion times, which is hugely problematic for use cases
     that create large numbers of VMs. Such use cases typically don't
     actually use irqbypass, but eliminating the pointless registration
     is a future problem to solve as it likely requires new uAPI

   - Track irqbypass's "token" as "struct eventfd_ctx *" instead of a
     "void *", to avoid making a simple concept unnecessarily difficult
     to understand

   - Decouple device posted IRQs from VFIO device assignment, as binding
     a VM to a VFIO group is not a requirement for enabling device
     posted IRQs

   - Clean up and document/comment the irqfd assignment code

   - Disallow binding multiple irqfds to an eventfd with a priority
     waiter, i.e. ensure an eventfd is bound to at most one irqfd
     through the entire host, and add a selftest to verify eventfd:irqfd
     bindings are globally unique

   - Add a tracepoint for KVM_SET_MEMORY_ATTRIBUTES to help debug issues
     related to private <=> shared memory conversions

   - Drop guest_memfd's .getattr() implementation as the VFS layer will
     call generic_fillattr() if inode_operations.getattr is NULL

   - Fix issues with dirty ring harvesting where KVM doesn't bound the
     processing of entries in any way, which allows userspace to keep
     KVM in a tight loop indefinitely

   - Kill off kvm_arch_{start,end}_assignment() and x86's associated
     tracking, now that KVM no longer uses assigned_device_count as a
     heuristic for either irqbypass usage or MDS mitigation

  Selftests:

   - Fix a comment typo

   - Verify KVM is loaded when getting any KVM module param so that
     attempting to run a selftest without kvm.ko loaded results in a
     SKIP message about KVM not being loaded/enabled (versus some random
     parameter not existing)

   - Skip tests that hit EACCES when attempting to access a file, and
     print a "Root required?" help message. In most cases, the test just
     needs to be run with elevated permissions"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (340 commits)
  Documentation: KVM: Use unordered list for pre-init VGIC registers
  RISC-V: KVM: Avoid re-acquiring memslot in kvm_riscv_gstage_map()
  RISC-V: KVM: Use find_vma_intersection() to search for intersecting VMAs
  RISC-V: perf/kvm: Add reporting of interrupt events
  RISC-V: KVM: Enable ring-based dirty memory tracking
  RISC-V: KVM: Fix inclusion of Smnpm in the guest ISA bitmap
  RISC-V: KVM: Delegate illegal instruction fault to VS mode
  RISC-V: KVM: Pass VMID as parameter to kvm_riscv_hfence_xyz() APIs
  RISC-V: KVM: Factor-out g-stage page table management
  RISC-V: KVM: Add vmid field to struct kvm_riscv_hfence
  RISC-V: KVM: Introduce struct kvm_gstage_mapping
  RISC-V: KVM: Factor-out MMU related declarations into separate headers
  RISC-V: KVM: Use ncsr_xyz() in kvm_riscv_vcpu_trap_redirect()
  RISC-V: KVM: Implement kvm_arch_flush_remote_tlbs_range()
  RISC-V: KVM: Don't flush TLB when PTE is unchanged
  RISC-V: KVM: Replace KVM_REQ_HFENCE_GVMA_VMID_ALL with KVM_REQ_TLB_FLUSH
  RISC-V: KVM: Rename and move kvm_riscv_local_tlb_sanitize()
  RISC-V: KVM: Drop the return value of kvm_riscv_vcpu_aia_init()
  RISC-V: KVM: Check kvm_riscv_vcpu_alloc_vector_context() return value
  KVM: arm64: selftests: Add FEAT_RAS EL2 registers to get-reg-list
  ...
2025-07-30 17:14:01 -07:00
Linus Torvalds
6fb44438a5 arm64 updates for 6.17:
Perf and PMU updates:
 
  - Add support for new (v3) Hisilicon SLLC and DDRC PMUs
 
  - Add support for Arm-NI PMU integrations that share interrupts between
    clock domains within a given instance
 
  - Allow SPE to be configured with a lower sample period than the
    minimum recommendation advertised by PMSIDR_EL1.Interval
 
  - Add suppport for Arm's "Branch Record Buffer Extension" (BRBE)
 
  - Adjust the perf watchdog period according to cpu frequency changes
 
  - Minor driver fixes and cleanups
 
 Hardware features:
 
  - Support for MTE store-only checking (FEAT_MTE_STORE_ONLY)
 
  - Support for reporting the non-address bits during a synchronous MTE
    tag check fault (FEAT_MTE_TAGGED_FAR)
 
  - Optimise the TLBI when folding/unfolding contiguous PTEs on hardware
    with FEAT_BBM (break-before-make) level 2 and no TLB conflict aborts
 
 Software features:
 
  - Enable HAVE_LIVEPATCH after implementing arch_stack_walk_reliable()
    and using the text-poke API for late module relocations
 
  - Force VMAP_STACK always on and change arm64_efi_rt_init() to use
    arch_alloc_vmap_stack() in order to avoid KASAN false positives
 
 ACPI:
 
  - Improve SPCR handling and messaging on systems lacking an SPCR table
 
 Debug:
 
  - Simplify the debug exception entry path
 
  - Drop redundant DBG_MDSCR_* macros
 
 Kselftests:
 
  - Cleanups and improvements for SME, SVE and FPSIMD tests
 
 Miscellaneous:
 
  - Optimise loop to reduce redundant operations in contpte_ptep_get()
 
  - Remove ISB when resetting POR_EL0 during signal handling
 
  - Mark the kernel as tainted on SEA and SError panic
 
  - Remove redundant gcs_free() call
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Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 updates from Catalin Marinas:
 "A quick summary: perf support for Branch Record Buffer Extensions
  (BRBE), typical PMU hardware updates, small additions to MTE for
  store-only tag checking and exposing non-address bits to signal
  handlers, HAVE_LIVEPATCH enabled on arm64, VMAP_STACK forced on.

  There is also a TLBI optimisation on hardware that does not require
  break-before-make when changing the user PTEs between contiguous and
  non-contiguous.

  More details:

  Perf and PMU updates:

   - Add support for new (v3) Hisilicon SLLC and DDRC PMUs

   - Add support for Arm-NI PMU integrations that share interrupts
     between clock domains within a given instance

   - Allow SPE to be configured with a lower sample period than the
     minimum recommendation advertised by PMSIDR_EL1.Interval

   - Add suppport for Arm's "Branch Record Buffer Extension" (BRBE)

   - Adjust the perf watchdog period according to cpu frequency changes

   - Minor driver fixes and cleanups

  Hardware features:

   - Support for MTE store-only checking (FEAT_MTE_STORE_ONLY)

   - Support for reporting the non-address bits during a synchronous MTE
     tag check fault (FEAT_MTE_TAGGED_FAR)

   - Optimise the TLBI when folding/unfolding contiguous PTEs on
     hardware with FEAT_BBM (break-before-make) level 2 and no TLB
     conflict aborts

  Software features:

   - Enable HAVE_LIVEPATCH after implementing arch_stack_walk_reliable()
     and using the text-poke API for late module relocations

   - Force VMAP_STACK always on and change arm64_efi_rt_init() to use
     arch_alloc_vmap_stack() in order to avoid KASAN false positives

  ACPI:

   - Improve SPCR handling and messaging on systems lacking an SPCR
     table

  Debug:

   - Simplify the debug exception entry path

   - Drop redundant DBG_MDSCR_* macros

  Kselftests:

   - Cleanups and improvements for SME, SVE and FPSIMD tests

  Miscellaneous:

   - Optimise loop to reduce redundant operations in contpte_ptep_get()

   - Remove ISB when resetting POR_EL0 during signal handling

   - Mark the kernel as tainted on SEA and SError panic

   - Remove redundant gcs_free() call"

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (93 commits)
  arm64/gcs: task_gcs_el0_enable() should use passed task
  arm64: Kconfig: Keep selects somewhat alphabetically ordered
  arm64: signal: Remove ISB when resetting POR_EL0
  kselftest/arm64: Handle attempts to disable SM on SME only systems
  kselftest/arm64: Fix SVE write data generation for SME only systems
  kselftest/arm64: Test SME on SME only systems in fp-ptrace
  kselftest/arm64: Test FPSIMD format data writes via NT_ARM_SVE in fp-ptrace
  kselftest/arm64: Allow sve-ptrace to run on SME only systems
  arm64/mm: Drop redundant addr increment in set_huge_pte_at()
  kselftest/arm4: Provide local defines for AT_HWCAP3
  arm64: Mark kernel as tainted on SAE and SError panic
  arm64/gcs: Don't call gcs_free() when releasing task_struct
  drivers/perf: hisi: Support PMUs with no interrupt
  drivers/perf: hisi: Relax the event number check of v2 PMUs
  drivers/perf: hisi: Add support for HiSilicon SLLC v3 PMU driver
  drivers/perf: hisi: Use ACPI driver_data to retrieve SLLC PMU information
  drivers/perf: hisi: Add support for HiSilicon DDRC v3 PMU driver
  drivers/perf: hisi: Simplify the probe process for each DDRC version
  perf/arm-ni: Support sharing IRQs within an NI instance
  perf/arm-ni: Consolidate CPU affinity handling
  ...
2025-07-29 20:21:54 -07:00
Paolo Bonzini
314b40b3b6 KVM/arm64 changes for 6.17, round #1
- Host driver for GICv5, the next generation interrupt controller for
    arm64, including support for interrupt routing, MSIs, interrupt
    translation and wired interrupts.
 
  - Use FEAT_GCIE_LEGACY on GICv5 systems to virtualize GICv3 VMs on
    GICv5 hardware, leveraging the legacy VGIC interface.
 
  - Userspace control of the 'nASSGIcap' GICv3 feature, allowing
    userspace to disable support for SGIs w/o an active state on hardware
    that previously advertised it unconditionally.
 
  - Map supporting endpoints with cacheable memory attributes on systems
    with FEAT_S2FWB and DIC where KVM no longer needs to perform cache
    maintenance on the address range.
 
  - Nested support for FEAT_RAS and FEAT_DoubleFault2, allowing the guest
    hypervisor to inject external aborts into an L2 VM and take traps of
    masked external aborts to the hypervisor.
 
  - Convert more system register sanitization to the config-driven
    implementation.
 
  - Fixes to the visibility of EL2 registers, namely making VGICv3 system
    registers accessible through the VGIC device instead of the ONE_REG
    vCPU ioctls.
 
  - Various cleanups and minor fixes.
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Merge tag 'kvmarm-6.17' of https://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm64 changes for 6.17, round #1

 - Host driver for GICv5, the next generation interrupt controller for
   arm64, including support for interrupt routing, MSIs, interrupt
   translation and wired interrupts.

 - Use FEAT_GCIE_LEGACY on GICv5 systems to virtualize GICv3 VMs on
   GICv5 hardware, leveraging the legacy VGIC interface.

 - Userspace control of the 'nASSGIcap' GICv3 feature, allowing
   userspace to disable support for SGIs w/o an active state on hardware
   that previously advertised it unconditionally.

 - Map supporting endpoints with cacheable memory attributes on systems
   with FEAT_S2FWB and DIC where KVM no longer needs to perform cache
   maintenance on the address range.

 - Nested support for FEAT_RAS and FEAT_DoubleFault2, allowing the guest
   hypervisor to inject external aborts into an L2 VM and take traps of
   masked external aborts to the hypervisor.

 - Convert more system register sanitization to the config-driven
   implementation.

 - Fixes to the visibility of EL2 registers, namely making VGICv3 system
   registers accessible through the VGIC device instead of the ONE_REG
   vCPU ioctls.

 - Various cleanups and minor fixes.
2025-07-29 12:27:40 -04:00
Linus Torvalds
8e736a2eea hardening updates for v6.17-rc1
- Introduce and start using TRAILING_OVERLAP() helper for fixing
   embedded flex array instances (Gustavo A. R. Silva)
 
 - mux: Convert mux_control_ops to a flex array member in mux_chip
   (Thorsten Blum)
 
 - string: Group str_has_prefix() and strstarts() (Andy Shevchenko)
 
 - Remove KCOV instrumentation from __init and __head (Ritesh Harjani,
   Kees Cook)
 
 - Refactor and rename stackleak feature to support Clang
 
 - Add KUnit test for seq_buf API
 
 - Fix KUnit fortify test under LTO
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Merge tag 'hardening-v6.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull hardening updates from Kees Cook:

 - Introduce and start using TRAILING_OVERLAP() helper for fixing
   embedded flex array instances (Gustavo A. R. Silva)

 - mux: Convert mux_control_ops to a flex array member in mux_chip
   (Thorsten Blum)

 - string: Group str_has_prefix() and strstarts() (Andy Shevchenko)

 - Remove KCOV instrumentation from __init and __head (Ritesh Harjani,
   Kees Cook)

 - Refactor and rename stackleak feature to support Clang

 - Add KUnit test for seq_buf API

 - Fix KUnit fortify test under LTO

* tag 'hardening-v6.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (22 commits)
  sched/task_stack: Add missing const qualifier to end_of_stack()
  kstack_erase: Support Clang stack depth tracking
  kstack_erase: Add -mgeneral-regs-only to silence Clang warnings
  init.h: Disable sanitizer coverage for __init and __head
  kstack_erase: Disable kstack_erase for all of arm compressed boot code
  x86: Handle KCOV __init vs inline mismatches
  arm64: Handle KCOV __init vs inline mismatches
  s390: Handle KCOV __init vs inline mismatches
  arm: Handle KCOV __init vs inline mismatches
  mips: Handle KCOV __init vs inline mismatch
  powerpc/mm/book3s64: Move kfence and debug_pagealloc related calls to __init section
  configs/hardening: Enable CONFIG_INIT_ON_FREE_DEFAULT_ON
  configs/hardening: Enable CONFIG_KSTACK_ERASE
  stackleak: Split KSTACK_ERASE_CFLAGS from GCC_PLUGINS_CFLAGS
  stackleak: Rename stackleak_track_stack to __sanitizer_cov_stack_depth
  stackleak: Rename STACKLEAK to KSTACK_ERASE
  seq_buf: Introduce KUnit tests
  string: Group str_has_prefix() and strstarts()
  kunit/fortify: Add back "volatile" for sizeof() constants
  acpi: nfit: intel: avoid multiple -Wflex-array-member-not-at-end warnings
  ...
2025-07-28 17:16:12 -07:00
Linus Torvalds
d900c4ce63 execve updates for v6.17
- Introduce regular REGSET note macros arch-wide (Dave Martin)
 
 - Remove arbitrary 4K limitation of program header size (Yin Fengwei)
 
 - Reorder function qualifiers for copy_clone_args_from_user() (Dishank Jogi)
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Merge tag 'execve-v6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull execve updates from Kees Cook:

 - Introduce regular REGSET note macros arch-wide (Dave Martin)

 - Remove arbitrary 4K limitation of program header size (Yin Fengwei)

 - Reorder function qualifiers for copy_clone_args_from_user() (Dishank Jogi)

* tag 'execve-v6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (25 commits)
  fork: reorder function qualifiers for copy_clone_args_from_user
  binfmt_elf: remove the 4k limitation of program header size
  binfmt_elf: Warn on missing or suspicious regset note names
  xtensa: ptrace: Use USER_REGSET_NOTE_TYPE() to specify regset note names
  um: ptrace: Use USER_REGSET_NOTE_TYPE() to specify regset note names
  x86/ptrace: Use USER_REGSET_NOTE_TYPE() to specify regset note names
  sparc: ptrace: Use USER_REGSET_NOTE_TYPE() to specify regset note names
  sh: ptrace: Use USER_REGSET_NOTE_TYPE() to specify regset note names
  s390/ptrace: Use USER_REGSET_NOTE_TYPE() to specify regset note names
  riscv: ptrace: Use USER_REGSET_NOTE_TYPE() to specify regset note names
  powerpc/ptrace: Use USER_REGSET_NOTE_TYPE() to specify regset note names
  parisc: ptrace: Use USER_REGSET_NOTE_TYPE() to specify regset note names
  openrisc: ptrace: Use USER_REGSET_NOTE_TYPE() to specify regset note names
  nios2: ptrace: Use USER_REGSET_NOTE_TYPE() to specify regset note names
  MIPS: ptrace: Use USER_REGSET_NOTE_TYPE() to specify regset note names
  m68k: ptrace: Use USER_REGSET_NOTE_TYPE() to specify regset note names
  LoongArch: ptrace: Use USER_REGSET_NOTE_TYPE() to specify regset note names
  hexagon: ptrace: Use USER_REGSET_NOTE_TYPE() to specify regset note names
  csky: ptrace: Use USER_REGSET_NOTE_TYPE() to specify regset note names
  arm64: ptrace: Use USER_REGSET_NOTE_TYPE() to specify regset note names
  ...
2025-07-28 17:11:40 -07:00
Oliver Upton
ccd73c5782 GICv5 initial host support
Add host kernel support for the new arm64 GICv5 architecture, which is
 quite a departure from the previous ones.
 
 Include support for the full gamut of the architecture (interrupt
 routing and delivery to CPUs, wired interrupts, MSIs, and interrupt
 translation).
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Merge tag 'irqchip-gic-v5-host' into kvmarm/next

GICv5 initial host support

Add host kernel support for the new arm64 GICv5 architecture, which is
quite a departure from the previous ones.

Include support for the full gamut of the architecture (interrupt
routing and delivery to CPUs, wired interrupts, MSIs, and interrupt
translation).

* tag 'irqchip-gic-v5-host': (32 commits)
  arm64: smp: Fix pNMI setup after GICv5 rework
  arm64: Kconfig: Enable GICv5
  docs: arm64: gic-v5: Document booting requirements for GICv5
  irqchip/gic-v5: Add GICv5 IWB support
  irqchip/gic-v5: Add GICv5 ITS support
  irqchip/msi-lib: Add IRQ_DOMAIN_FLAG_FWNODE_PARENT handling
  irqchip/gic-v3: Rename GICv3 ITS MSI parent
  PCI/MSI: Add pci_msi_map_rid_ctlr_node() helper function
  of/irq: Add of_msi_xlate() helper function
  irqchip/gic-v5: Enable GICv5 SMP booting
  irqchip/gic-v5: Add GICv5 LPI/IPI support
  irqchip/gic-v5: Add GICv5 IRS/SPI support
  irqchip/gic-v5: Add GICv5 PPI support
  arm64: Add support for GICv5 GSB barriers
  arm64: smp: Support non-SGIs for IPIs
  arm64: cpucaps: Add GICv5 CPU interface (GCIE) capability
  arm64: cpucaps: Rename GICv3 CPU interface capability
  arm64: Disable GICv5 read/write/instruction traps
  arm64/sysreg: Add ICH_HFGITR_EL2
  arm64/sysreg: Add ICH_HFGWTR_EL2
  ...

Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-07-26 08:49:42 -07:00
Catalin Marinas
5b1ae9de71 Merge branch 'for-next/feat_mte_store_only' into for-next/core
* for-next/feat_mte_store_only:
  : MTE feature to restrict tag checking to store only operations
  kselftest/arm64/mte: Add MTE_STORE_ONLY testcases
  kselftest/arm64/mte: Preparation for mte store only test
  kselftest/arm64/abi: Add MTE_STORE_ONLY feature hwcap test
  KVM: arm64: Expose MTE_STORE_ONLY feature to guest
  arm64/hwcaps: Add MTE_STORE_ONLY hwcaps
  arm64/kernel: Support store-only mte tag check
  prctl: Introduce PR_MTE_STORE_ONLY
  arm64/cpufeature: Add MTE_STORE_ONLY feature
2025-07-24 16:03:34 +01:00
Catalin Marinas
3ae8cef210 Merge branches 'for-next/livepatch', 'for-next/user-contig-bbml2', 'for-next/misc', 'for-next/acpi', 'for-next/debug-entry', 'for-next/feat_mte_tagged_far', 'for-next/kselftest', 'for-next/mdscr-cleanup' and 'for-next/vmap-stack', remote-tracking branch 'arm64/for-next/perf' into for-next/core
* arm64/for-next/perf: (23 commits)
  drivers/perf: hisi: Support PMUs with no interrupt
  drivers/perf: hisi: Relax the event number check of v2 PMUs
  drivers/perf: hisi: Add support for HiSilicon SLLC v3 PMU driver
  drivers/perf: hisi: Use ACPI driver_data to retrieve SLLC PMU information
  drivers/perf: hisi: Add support for HiSilicon DDRC v3 PMU driver
  drivers/perf: hisi: Simplify the probe process for each DDRC version
  perf/arm-ni: Support sharing IRQs within an NI instance
  perf/arm-ni: Consolidate CPU affinity handling
  perf/cxlpmu: Fix typos in cxl_pmu.c comments and documentation
  perf/cxlpmu: Remove unintended newline from IRQ name format string
  perf/cxlpmu: Fix devm_kcalloc() argument order in cxl_pmu_probe()
  perf: arm_spe: Relax period restriction
  perf: arm_pmuv3: Add support for the Branch Record Buffer Extension (BRBE)
  KVM: arm64: nvhe: Disable branch generation in nVHE guests
  arm64: Handle BRBE booting requirements
  arm64/sysreg: Add BRBE registers and fields
  perf/arm: Add missing .suppress_bind_attrs
  perf/arm-cmn: Reduce stack usage during discovery
  perf: imx9_perf: make the read-only array mask static const
  perf/arm-cmn: Broaden module description for wider interconnect support
  ...

* for-next/livepatch:
  : Support for HAVE_LIVEPATCH on arm64
  arm64: Kconfig: Keep selects somewhat alphabetically ordered
  arm64: Implement HAVE_LIVEPATCH
  arm64: stacktrace: Implement arch_stack_walk_reliable()
  arm64: stacktrace: Check kretprobe_find_ret_addr() return value
  arm64/module: Use text-poke API for late relocations.

* for-next/user-contig-bbml2:
  : Optimise the TLBI when folding/unfolding contigous PTEs on hardware with BBML2 and no TLB conflict aborts
  arm64/mm: Elide tlbi in contpte_convert() under BBML2
  iommu/arm: Add BBM Level 2 smmu feature
  arm64: Add BBM Level 2 cpu feature
  arm64: cpufeature: Introduce MATCH_ALL_EARLY_CPUS capability type

* for-next/misc:
  : Miscellaneous arm64 patches
  arm64/gcs: task_gcs_el0_enable() should use passed task
  arm64: signal: Remove ISB when resetting POR_EL0
  arm64/mm: Drop redundant addr increment in set_huge_pte_at()
  arm64: Mark kernel as tainted on SAE and SError panic
  arm64/gcs: Don't call gcs_free() when releasing task_struct
  arm64: fix unnecessary rebuilding when CONFIG_DEBUG_EFI=y
  arm64/mm: Optimize loop to reduce redundant operations of contpte_ptep_get
  arm64: pi: use 'targets' instead of extra-y in Makefile

* for-next/acpi:
  : Various ACPI arm64 changes
  ACPI: Suppress misleading SPCR console message when SPCR table is absent
  ACPI: Return -ENODEV from acpi_parse_spcr() when SPCR support is disabled

* for-next/debug-entry:
  : Simplify the debug exception entry path
  arm64: debug: remove debug exception registration infrastructure
  arm64: debug: split bkpt32 exception entry
  arm64: debug: split brk64 exception entry
  arm64: debug: split hardware watchpoint exception entry
  arm64: debug: split single stepping exception entry
  arm64: debug: refactor reinstall_suspended_bps()
  arm64: debug: split hardware breakpoint exception entry
  arm64: entry: Add entry and exit functions for debug exceptions
  arm64: debug: remove break/step handler registration infrastructure
  arm64: debug: call step handlers statically
  arm64: debug: call software breakpoint handlers statically
  arm64: refactor aarch32_break_handler()
  arm64: debug: clean up single_step_handler logic

* for-next/feat_mte_tagged_far:
  : Support for reporting the non-address bits during a synchronous MTE tag check fault
  kselftest/arm64/mte: Add mtefar tests on check_mmap_options
  kselftest/arm64/mte: Refactor check_mmap_option test
  kselftest/arm64/mte: Add verification for address tag in signal handler
  kselftest/arm64/mte: Add address tag related macro and function
  kselftest/arm64/mte: Check MTE_FAR feature is supported
  kselftest/arm64/mte: Register mte signal handler with SA_EXPOSE_TAGBITS
  kselftest/arm64: Add MTE_FAR hwcap test
  KVM: arm64: Expose FEAT_MTE_TAGGED_FAR feature to guest
  arm64: Report address tag when FEAT_MTE_TAGGED_FAR is supported
  arm64/cpufeature: Add FEAT_MTE_TAGGED_FAR feature

* for-next/kselftest:
  : Kselftest updates for arm64
  kselftest/arm64: Handle attempts to disable SM on SME only systems
  kselftest/arm64: Fix SVE write data generation for SME only systems
  kselftest/arm64: Test SME on SME only systems in fp-ptrace
  kselftest/arm64: Test FPSIMD format data writes via NT_ARM_SVE in fp-ptrace
  kselftest/arm64: Allow sve-ptrace to run on SME only systems
  kselftest/arm4: Provide local defines for AT_HWCAP3
  kselftest/arm64: Specify SVE data when testing VL set in sve-ptrace
  kselftest/arm64: Fix test for streaming FPSIMD write in sve-ptrace
  kselftest/arm64: Fix check for setting new VLs in sve-ptrace
  kselftest/arm64: Convert tpidr2 test to use kselftest.h

* for-next/mdscr-cleanup:
  : Drop redundant DBG_MDSCR_* macros
  KVM: selftests: Change MDSCR_EL1 register holding variables as uint64_t
  arm64/debug: Drop redundant DBG_MDSCR_* macros

* for-next/vmap-stack:
  : Force VMAP_STACK on arm64
  arm64: remove CONFIG_VMAP_STACK checks from entry code
  arm64: remove CONFIG_VMAP_STACK checks from SDEI stack handling
  arm64: remove CONFIG_VMAP_STACK checks from stacktrace overflow logic
  arm64: remove CONFIG_VMAP_STACK conditionals from traps overflow stack
  arm64: remove CONFIG_VMAP_STACK conditionals from irq stack setup
  arm64: Remove CONFIG_VMAP_STACK conditionals from THREAD_SHIFT and THREAD_ALIGN
  arm64: efi: Remove CONFIG_VMAP_STACK check
  arm64: Mandate VMAP_STACK
  arm64: efi: Fix KASAN false positive for EFI runtime stack
  arm64/ptrace: Fix stack-out-of-bounds read in regs_get_kernel_stack_nth()
  arm64/gcs: Don't call gcs_free() during flush_gcs()
  arm64: Restrict pagetable teardown to avoid false warning
  docs: arm64: Fix ICC_SRE_EL2 register typo in booting.rst
2025-07-24 16:01:22 +01:00
Jeremy Linton
cbbcfb94c5 arm64/gcs: task_gcs_el0_enable() should use passed task
Mark Rutland noticed that the task parameter is ignored and
'current' is being used instead. Since this is usually
what its passed, it hasn't yet been causing problems but likely
will as the code gets more testing.

But, once this is fixed, it creates a new bug in copy_thread_gcs()
since the gcs_el_mode isn't yet set for the task before its being
checked. Move gcs_alloc_thread_stack() after the new task's
gcs_el0_mode initialization to avoid this.

Fixes: fc84bc5378 ("arm64/gcs: Context switch GCS state for EL0")
Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20250719043740.4548-2-jeremy.linton@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2025-07-23 12:08:17 +01:00
Ada Couprie Diaz
d42e6c20de arm64/entry: Mask DAIF in cpu_switch_to(), call_on_irq_stack()
`cpu_switch_to()` and `call_on_irq_stack()` manipulate SP to change
to different stacks along with the Shadow Call Stack if it is enabled.
Those two stack changes cannot be done atomically and both functions
can be interrupted by SErrors or Debug Exceptions which, though unlikely,
is very much broken : if interrupted, we can end up with mismatched stacks
and Shadow Call Stack leading to clobbered stacks.

In `cpu_switch_to()`, it can happen when SP_EL0 points to the new task,
but x18 stills points to the old task's SCS. When the interrupt handler
tries to save the task's SCS pointer, it will save the old task
SCS pointer (x18) into the new task struct (pointed to by SP_EL0),
clobbering it.

In `call_on_irq_stack()`, it can happen when switching from the task stack
to the IRQ stack and when switching back. In both cases, we can be
interrupted when the SCS pointer points to the IRQ SCS, but SP points to
the task stack. The nested interrupt handler pushes its return addresses
on the IRQ SCS. It then detects that SP points to the task stack,
calls `call_on_irq_stack()` and clobbers the task SCS pointer with
the IRQ SCS pointer, which it will also use !

This leads to tasks returning to addresses on the wrong SCS,
or even on the IRQ SCS, triggering kernel panics via CONFIG_VMAP_STACK
or FPAC if enabled.

This is possible on a default config, but unlikely.
However, when enabling CONFIG_ARM64_PSEUDO_NMI, DAIF is unmasked and
instead the GIC is responsible for filtering what interrupts the CPU
should receive based on priority.
Given the goal of emulating NMIs, pseudo-NMIs can be received by the CPU
even in `cpu_switch_to()` and `call_on_irq_stack()`, possibly *very*
frequently depending on the system configuration and workload, leading
to unpredictable kernel panics.

Completely mask DAIF in `cpu_switch_to()` and restore it when returning.
Do the same in `call_on_irq_stack()`, but restore and mask around
the branch.
Mask DAIF even if CONFIG_SHADOW_CALL_STACK is not enabled for consistency
of behaviour between all configurations.

Introduce and use an assembly macro for saving and masking DAIF,
as the existing one saves but only masks IF.

Cc: <stable@vger.kernel.org>
Signed-off-by: Ada Couprie Diaz <ada.coupriediaz@arm.com>
Reported-by: Cristian Prundeanu <cpru@amazon.com>
Fixes: 59b37fe52f ("arm64: Stash shadow stack pointer in the task struct on interrupt")
Tested-by: Cristian Prundeanu <cpru@amazon.com>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20250718142814.133329-1-ada.coupriediaz@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
2025-07-22 16:39:30 +01:00
Kevin Brodsky
1a665a71ef arm64: signal: Remove ISB when resetting POR_EL0
POR_EL0 is set to its most permissive value before setting up the
signal frame, to ensure that uaccess succeeds regardless of the
signal stack's pkey.

We are now tolerant to spurious POE faults. This means that we do
not strictly need to issue an ISB after updating POR_EL0, even when
followed by uaccess. The question is whether a fault is likely to
happen or not if the ISB is omitted; in this case the answer seems
to be no. If the regular stack is used, then it should already be
accessible. If the alternate signal stack is used, then a special
(inaccessible) pkey may be used - the assumption is that this
situation is very uncommon.

Remove the ISB to speed up the regular path - this should not have
any functional impact regardless of the scenario.

Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com>
Link: https://lore.kernel.org/r/20250619160042.2499290-3-kevin.brodsky@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2025-07-22 10:44:57 +01:00
Kees Cook
76261fc7d1 stackleak: Split KSTACK_ERASE_CFLAGS from GCC_PLUGINS_CFLAGS
In preparation for Clang stack depth tracking for KSTACK_ERASE,
split the stackleak-specific cflags out of GCC_PLUGINS_CFLAGS into
KSTACK_ERASE_CFLAGS.

Link: https://lore.kernel.org/r/20250717232519.2984886-3-kees@kernel.org
Signed-off-by: Kees Cook <kees@kernel.org>
2025-07-21 21:40:57 -07:00
Kees Cook
57fbad15c2 stackleak: Rename STACKLEAK to KSTACK_ERASE
In preparation for adding Clang sanitizer coverage stack depth tracking
that can support stack depth callbacks:

- Add the new top-level CONFIG_KSTACK_ERASE option which will be
  implemented either with the stackleak GCC plugin, or with the Clang
  stack depth callback support.
- Rename CONFIG_GCC_PLUGIN_STACKLEAK as needed to CONFIG_KSTACK_ERASE,
  but keep it for anything specific to the GCC plugin itself.
- Rename all exposed "STACKLEAK" names and files to "KSTACK_ERASE" (named
  for what it does rather than what it protects against), but leave as
  many of the internals alone as possible to avoid even more churn.

While here, also split "prev_lowest_stack" into CONFIG_KSTACK_ERASE_METRICS,
since that's the only place it is referenced from.

Suggested-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20250717232519.2984886-1-kees@kernel.org
Signed-off-by: Kees Cook <kees@kernel.org>
2025-07-21 21:35:01 -07:00
Breno Leitao
d7ce7e3a84 arm64: Mark kernel as tainted on SAE and SError panic
Set TAINT_MACHINE_CHECK when SError or Synchronous External Abort (SEA)
interrupts trigger a panic to flag potential hardware faults. This
tainting mechanism aids in debugging and enables correlation of
hardware-related crashes in large-scale deployments.

This change aligns with similar patches[1] that mark machine check
events when the system crashes due to hardware errors.

Link: https://lore.kernel.org/all/20250702-add_tain-v1-1-9187b10914b9@debian.org/ [1]
Signed-off-by: Breno Leitao <leitao@debian.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20250716-vmcore_hw_error-v2-1-f187f7d62aba@debian.org
Signed-off-by: Will Deacon <will@kernel.org>
2025-07-17 11:07:15 +01:00
Marc Zyngier
65a5520a27 arm64: smp: Fix pNMI setup after GICv5 rework
Breno reports that pNMIs are not behaving the way they should since
they were reworked for GICv5. Turns out we feed the IRQ number to
the pNMI helper instead of the IPI number -- not a good idea.

Fix it by providing the correct number (duh).

Fixes: ba1004f861 ("arm64: smp: Support non-SGIs for IPIs")
Reported-by: Breno Leitao <leitao@debian.org>
Suggested-by: Lorenzo Pieralisi <lpieralisi@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-07-15 18:11:12 +01:00
Mark Brown
75fdf823f9 arm64/gcs: Don't call gcs_free() when releasing task_struct
Currently we call gcs_free() when releasing task_struct but this is
redundant, it attempts to deallocate any kernel managed userspace GCS
which should no longer be relevant and resets values in the struct we're
in the process of freeing.

By the time arch_release_task_struct() is called the mm will have been
disassociated from the task so the check for a mm in gcs_free() will
always be false, for threads that are exiting leaving the mm active
deactivate_mm() will have been called previously and freed any kernel
managed GCS.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20250714-arm64-gcs-release-task-v2-1-8a83cadfc846@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
2025-07-15 14:58:23 +01:00
Dave Martin
87b0d081dc arm64: ptrace: Use USER_REGSET_NOTE_TYPE() to specify regset note names
Instead of having the core code guess the note name for each regset,
use USER_REGSET_NOTE_TYPE() to pick the correct name from elf.h.

This does not affect the correctness of switch(note_type) and similar
code, since note type values known to Linux for coredump purposes were
already required to be unique.

Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Kees Cook <kees@kernel.org>
Cc: Akihiko Odaki <akihiko.odaki@daynix.com>
Cc: linux-arm-kernel@lists.infradead.org
Reviewed-by: Akihiko Odaki <odaki@rsg.ci.i.u-tokyo.ac.jp>
Link: https://lore.kernel.org/r/20250701135616.29630-7-Dave.Martin@arm.com
Signed-off-by: Kees Cook <kees@kernel.org>
2025-07-14 22:27:47 -07:00
Oliver Upton
e3fd66620f arm64: Detect FEAT_DoubleFault2
KVM will soon support FEAT_DoubleFault2. Add a descriptor for the
corresponding ID register field.

Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20250708172532.1699409-3-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-07-08 10:40:30 -07:00
Oliver Upton
bf49e73dde arm64: Detect FEAT_SCTLR2
KVM is about to pick up support for SCTLR2. Add cpucap for later use in
the guest/host context switch hot path.

Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20250708172532.1699409-2-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-07-08 10:40:30 -07:00
Lorenzo Pieralisi
0f01013258 irqchip/gic-v5: Add GICv5 LPI/IPI support
An IRS supports Logical Peripheral Interrupts (LPIs) and implement
Linux IPIs on top of it.

LPIs are used for interrupt signals that are translated by a
GICv5 ITS (Interrupt Translation Service) but also for software
generated IRQs - namely interrupts that are not driven by a HW
signal, ie IPIs.

LPIs rely on memory storage for interrupt routing and state.

LPIs state and routing information is kept in the Interrupt
State Table (IST).

IRSes provide support for 1- or 2-level IST tables configured
to support a maximum number of interrupts that depend on the
OS configuration and the HW capabilities.

On systems that provide 2-level IST support, always allow
the maximum number of LPIs; On systems with only 1-level
support, limit the number of LPIs to 2^12 to prevent
wasting memory (presumably a system that supports a 1-level
only IST is not expecting a large number of interrupts).

On a 2-level IST system, L2 entries are allocated on
demand.

The IST table memory is allocated using the kmalloc() interface;
the allocation required may be smaller than a page and must be
made up of contiguous physical pages if larger than a page.

On systems where the IRS is not cache-coherent with the CPUs,
cache mainteinance operations are executed to clean and
invalidate the allocated memory to the point of coherency
making it visible to the IRS components.

On GICv5 systems, IPIs are implemented using LPIs.

Add an LPI IRQ domain and implement an IPI-specific IRQ domain created
as a child/subdomain of the LPI domain to allocate the required number
of LPIs needed to implement the IPIs.

IPIs are backed by LPIs, add LPIs allocation/de-allocation
functions.

The LPI INTID namespace is managed using an IDA to alloc/free LPI INTIDs.

Associate an IPI irqchip with IPI IRQ descriptors to provide
core code with the irqchip.ipi_send_single() method required
to raise an IPI.

Co-developed-by: Sascha Bischoff <sascha.bischoff@arm.com>
Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
Co-developed-by: Timothy Hayes <timothy.hayes@arm.com>
Signed-off-by: Timothy Hayes <timothy.hayes@arm.com>
Signed-off-by: Lorenzo Pieralisi <lpieralisi@kernel.org>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Cc: Will Deacon <will@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20250703-gicv5-host-v7-22-12e71f1b3528@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-07-08 18:35:51 +01:00
Marc Zyngier
ba1004f861 arm64: smp: Support non-SGIs for IPIs
The arm64 arch has relied so far on GIC architectural software
generated interrupt (SGIs) to handle IPIs. Those are per-cpu
software generated interrupts.

arm64 architecture code that allocates the IPIs virtual IRQs and
IRQ descriptors was written accordingly.

On GICv5 systems, IPIs are implemented using LPIs that are not
per-cpu interrupts - they are just normal routable IRQs.

Add arch code to set-up IPIs on systems where they are handled
using normal routable IRQs.

For those systems, force the IRQ affinity (and make it immutable)
to the cpu a given IRQ was assigned to.

Signed-off-by: Timothy Hayes <timothy.hayes@arm.com>
[lpieralisi: changed affinity set-up, log]
Signed-off-by: Lorenzo Pieralisi <lpieralisi@kernel.org>
Cc: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20250703-gicv5-host-v7-18-12e71f1b3528@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-07-08 18:35:51 +01:00
Lorenzo Pieralisi
988699f9e6 arm64: cpucaps: Add GICv5 CPU interface (GCIE) capability
Implement the GCIE capability as a strict boot cpu capability to
detect whether architectural GICv5 support is available in HW.

Plug it in with a naming consistent with the existing GICv3
CPU interface capability.

Signed-off-by: Lorenzo Pieralisi <lpieralisi@kernel.org>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Cc: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20250703-gicv5-host-v7-17-12e71f1b3528@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-07-08 18:35:51 +01:00
Lorenzo Pieralisi
0bb5b6faa0 arm64: cpucaps: Rename GICv3 CPU interface capability
In preparation for adding a GICv5 CPU interface capability,
rework the existing GICv3 CPUIF capability - change its name and
description so that the subsequent GICv5 CPUIF capability
can be added with a more consistent naming on top.

Suggested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Lorenzo Pieralisi <lpieralisi@kernel.org>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Cc: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20250703-gicv5-host-v7-16-12e71f1b3528@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-07-08 18:35:51 +01:00
Masahiro Yamada
344b658047 arm64: fix unnecessary rebuilding when CONFIG_DEBUG_EFI=y
When CONFIG_DEBUG_EFI is enabled, some objects are needlessly rebuilt.

[Steps to reproduce]

  Enable CONFIG_DEBUG_EFI and run 'make' twice in a clean source tree.
  On the second run, arch/arm64/kernel/head.o is rebuilt even though
  no files have changed.

  $ make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- clean
  $ make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu-
     [ snip ]
  $ make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu-
    CALL    scripts/checksyscalls.sh
    AS      arch/arm64/kernel/head.o
    AR      arch/arm64/kernel/built-in.a
    AR      arch/arm64/built-in.a
    AR      built-in.a
     [ snip ]

The issue is caused by the use of the $(realpath ...) function.

At the time arch/arm64/kernel/Makefile is parsed on the first run,
$(objtree)/vmlinux does not exist. As a result,
$(realpath $(objtree)/vmlinux) expands to an empty string.

On the second run of Make, $(objtree)/vmlinux already exists, so
$(realpath $(objtree)/vmlinux) expands to the absolute path of vmlinux.
However, this change in the command line causes arch/arm64/kernel/head.o
to be rebuilt.

To address this issue, use $(abspath ...) instead, which does not require
the file to exist. While $(abspath ...) does not resolve symlinks, this
should be fine from a debugging perspective.

The GNU Make manual [1] clearly explains the difference between the two:

  $(realpath names...)
    For each file name in names return the canonical absolute name.
    A canonical name does not contain any . or .. components, nor any
    repeated path separators (/) or symlinks. In case of a failure the
    empty string is returned. Consult the realpath(3) documentation for
    a list of possible failure causes.

  $(abspath namees...)
    For each file name in names return an absolute name that does not
    contain any . or .. components, nor any repeated path separators (/).
    Note that, in contrast to realpath function, abspath does not resolve
    symlinks and does not require the file names to refer to an existing
    file or directory. Use the wildcard function to test for existence.

The same problem exists in drivers/firmware/efi/libstub/Makefile.zboot.
On the first run of Make, $(obj)/vmlinuz.efi.elf does not exist when the
Makefile is parsed, so -DZBOOT_EFI_PATH is set to an empty string.
Replace $(realpath ...) with $(abspath ...) there as well.

[1]: https://www.gnu.org/software/make/manual/make.html#File-Name-Functions

Fixes: 757b435aaa ("efi: arm64: Add vmlinux debug link to the Image binary")
Fixes: a050910972 ("efi/libstub: implement generic EFI zboot")
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20250625125555.2504734-1-masahiroy@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
2025-07-08 14:05:29 +01:00
Breno Leitao
9d1869f0f5 arm64: remove CONFIG_VMAP_STACK checks from entry code
With VMAP_STACK now always enabled on arm64, remove all CONFIG_VMAP_STACK
conditionals from entry handling in arch/arm64/kernel/entry-common.c and
arch/arm64/kernel/entry.S.

This change unconditionally includes the bad stack handling and overflow
detection logic, simplifying the code and reflecting the mandatory use of
VMAP_STACK for all arm64 kernel builds.

Signed-off-by: Breno Leitao <leitao@debian.org>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20250707-arm64_vmap-v1-8-8de98ca0f91c@debian.org
Signed-off-by: Will Deacon <will@kernel.org>
2025-07-08 13:41:09 +01:00
Breno Leitao
3e72b9e9f0 arm64: remove CONFIG_VMAP_STACK checks from SDEI stack handling
With VMAP_STACK now always enabled on arm64, remove all
CONFIG_VMAP_STACK conditionals from SDEI stack allocation and
initialization in arch/arm64/kernel/sdei.c.

This change unconditionally defines the SDEI stack pointers and replaces
runtime checks with BUILD_BUG_ON() assertions, ensuring that the code is
only built when VMAP_STACK is enabled. This simplifies the logic and
reflects the mandatory use of VMAP_STACK for all arm64 kernel builds.

Signed-off-by: Breno Leitao <leitao@debian.org>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20250707-arm64_vmap-v1-7-8de98ca0f91c@debian.org
Signed-off-by: Will Deacon <will@kernel.org>
2025-07-08 13:41:09 +01:00
Breno Leitao
907cb5cd8e arm64: remove CONFIG_VMAP_STACK checks from stacktrace overflow logic
With VMAP_STACK now always enabled on arm64, remove all CONFIG_VMAP_STACK
conditionals from overflow stack handling in stacktrace code.

This change unconditionally defines the per-CPU overflow_stack and
stackinfo_get_overflow() helper in arch/arm64/include/asm/stacktrace.h,
and always includes the overflow stack in the stack_info array in
arch/arm64/kernel/stacktrace.c. Also, drop redundant CONFIG_VMAP_STACK
checks from SDEI stack declarations.

Signed-off-by: Breno Leitao <leitao@debian.org>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20250707-arm64_vmap-v1-6-8de98ca0f91c@debian.org
Signed-off-by: Will Deacon <will@kernel.org>
2025-07-08 13:41:09 +01:00
Breno Leitao
e5692bba1e arm64: remove CONFIG_VMAP_STACK conditionals from traps overflow stack
With VMAP_STACK now always enabled on arm64, remove the
CONFIG_VMAP_STACK checks from overflow stack definitions and related
code in arch/arm64/kernel/traps.c. The overflow_stack and
panic_bad_stack() logic are now unconditionally included, simplifying
the source and matching the mandatory stack model.

Signed-off-by: Breno Leitao <leitao@debian.org>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20250707-arm64_vmap-v1-5-8de98ca0f91c@debian.org
Signed-off-by: Will Deacon <will@kernel.org>
2025-07-08 13:41:08 +01:00
Breno Leitao
c4a5699d5c arm64: remove CONFIG_VMAP_STACK conditionals from irq stack setup
With VMAP_STACK always enabled on arm64, drop the CONFIG_VMAP_STACK
checks and legacy irq stack allocation from arch/arm64/kernel/irq.c. The
code now unconditionally uses the VMAP_STACK path for irq stack
initialization, simplifying the logic.

Signed-off-by: Breno Leitao <leitao@debian.org>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20250707-arm64_vmap-v1-4-8de98ca0f91c@debian.org
Signed-off-by: Will Deacon <will@kernel.org>
2025-07-08 13:41:08 +01:00
Breno Leitao
63829521a8 arm64: efi: Remove CONFIG_VMAP_STACK check
Remove the CONFIG_VMAP_STACK check in arm64_efi_rt_init() since
VMAP_STACK is now always enabled on arm64.

The arch_alloc_vmap_stack() call will fail to build if VMAP_STACK
is not set, providing sufficient protection without the explicit
runtime check.

Signed-off-by: Breno Leitao <leitao@debian.org>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20250707-arm64_vmap-v1-2-8de98ca0f91c@debian.org
Signed-off-by: Will Deacon <will@kernel.org>
2025-07-08 13:41:08 +01:00
Ada Couprie Diaz
a8b8cce9d9 arm64: debug: remove debug exception registration infrastructure
Now that debug exceptions are handled individually and without the need
for dynamic registration, remove the unused registration infrastructure.

This removes the external caller for `debug_exception_enter()` and
`debug_exception_exit()`.
Make them static again and remove them from the header.

Remove `early_brk64()` as it has been made redundant by
(arm64: debug: split brk64 exception entry) and is not used anymore.
Note : in `early_brk64()` `bug_brk_handler()` is called unconditionally
as a fall-through, but now `call_break_hook()` only calls it if the
immediate matches.
This does not change the behaviour in early boot, as if
`bug_brk_handler()` was called on a non-BUG immediate it would return
DBG_HOOK_ERROR anyway, which `call_break_hook()` will do if no immediate
matches.

Remove `trap_init()`, as it would be empty and a weak definition already
exists in `init/main.c`.

Signed-off-by: Ada Couprie Diaz <ada.coupriediaz@arm.com>
Tested-by: Luis Claudio R. Goncalves <lgoncalv@redhat.com>
Reviewed-by: Will Deacon <will@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20250707114109.35672-14-ada.coupriediaz@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
2025-07-08 13:27:42 +01:00
Ada Couprie Diaz
fc5e5d0477 arm64: debug: split bkpt32 exception entry
Currently all debug exceptions share common entry code and are routed
to `do_debug_exception()`, which calls dynamically-registered
handlers for each specific debug exception. This is unfortunate as
different debug exceptions have different entry handling requirements,
and it would be better to handle these distinct requirements earlier.

The BKPT32 exception can only be triggered by a BKPT instruction. Thus,
we know that the PC is a legitimate address and isn't being used to train
a branch predictor with a bogus address : we don't need to call
`arm64_apply_bp_hardening()`.

The handler for this exception only pends a signal and doesn't depend
on any per-CPU state : we don't need to inhibit preemption, nor do we
need to keep the DAIF exceptions masked, so we can unmask them earlier.

Split the BKPT32 exception entry and adjust function signatures and its
behaviour to match its relaxed constraints compared to other
debug exceptions.
We can also remove `NOKRPOBE_SYMBOL`, as this cannot lead to a kprobe
recursion.

This replaces the last usage of `el0_dbg()`, so remove it.

Signed-off-by: Ada Couprie Diaz <ada.coupriediaz@arm.com>
Tested-by: Luis Claudio R. Goncalves <lgoncalv@redhat.com>
Reviewed-by: Will Deacon <will@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20250707114109.35672-13-ada.coupriediaz@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
2025-07-08 13:27:42 +01:00
Ada Couprie Diaz
31575e11ec arm64: debug: split brk64 exception entry
Currently all debug exceptions share common entry code and are routed
to `do_debug_exception()`, which calls dynamically-registered
handlers for each specific debug exception. This is unfortunate as
different debug exceptions have different entry handling requirements,
and it would be better to handle these distinct requirements earlier.

The BRK64 instruction can only be triggered by a BRK instruction. Thus,
we know that the PC is a legitimate address and isn't being used to train
a branch predictor with a bogus address : we don't need to call
`arm64_apply_bp_hardening()`.

We do not need to handle the Cortex-A76 erratum #1463225 either, as it
only relevant for single stepping at EL1.
BRK64 does not write FAR_EL1 either, as only hardware watchpoints do so.

Split the BRK64 exception entry, adjust the function signature, and its
behaviour to match the lack of needed mitigations.
Further, as the EL0 and EL1 code paths are cleanly separated, we can split
`do_brk64()` into `do_el0_brk64()` and `do_el1_brk64()`, and call them
directly from the relevant entry paths.
Use `die()` directly for the EL1 error path, as in `do_el1_bti()` and
`do_el1_undef()`.
We can also remove `NOKRPOBE_SYMBOL` for the EL0 path, as it cannot
lead to a kprobe recursion.

When taking a BRK64 exception from EL0, the exception handling is safely
preemptible : the only possible handler is `uprobe_brk_handler()`.
It only operates on task-local data and properly checks its validity,
then raises a Thread Information Flag, processed before returning
to userspace in `do_notify_resume()`, which is already preemptible.
Thus we can safely unmask interrupts and enable preemption before
handling the break itself, fixing a PREEMPT_RT issue where the handler
could call a sleeping function with preemption disabled.

Given that the break hook registration is handled statically in
`call_break_hook` since
(arm64: debug: call software break handlers statically)
and that we now bypass the exception handler registration, this change
renders `early_brk64` redundant : its functionality is now handled through
the post-init path.

This also removes the last usage of `el1_dbg()`.

This also removes the last usage of `el0_dbg()` without `CONFIG_COMPAT`.
Mark it `__maybe_unused`, to prevent a warning when building this patch
without `CONFIG_COMPAT`, as the following patch removes `el0_dbg()`.

Signed-off-by: Ada Couprie Diaz <ada.coupriediaz@arm.com>
Tested-by: Luis Claudio R. Goncalves <lgoncalv@redhat.com>
Reviewed-by: Will Deacon <will@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20250707114109.35672-12-ada.coupriediaz@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
2025-07-08 13:27:42 +01:00
Ada Couprie Diaz
413f0bba00 arm64: debug: split hardware watchpoint exception entry
Currently all debug exceptions share common entry code and are routed
to `do_debug_exception()`, which calls dynamically-registered
handlers for each specific debug exception. This is unfortunate as
different debug exceptions have different entry handling requirements,
and it would be better to handle these distinct requirements earlier.

Hardware watchpoints are the only debug exceptions that will write
FAR_EL1, so we need to preserve it and pass it down.
However, they cannot be used to maliciously train branch predictors, so
we can omit calling `arm64_bp_hardening()`, nor do they need to handle
the Cortex-A76 erratum #1463225, as it only applies to single stepping
exceptions.

As the hardware watchpoint handler only returns 0 and never triggers
the call to `arm64_notify_die()`, we can call it directly from
`entry-common.c`.
Split the hardware watchpoint exception entry and adjust the behaviour
to match the lack of needed mitigations.

Signed-off-by: Ada Couprie Diaz <ada.coupriediaz@arm.com>
Tested-by: Luis Claudio R. Goncalves <lgoncalv@redhat.com>
Reviewed-by: Will Deacon <will@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20250707114109.35672-11-ada.coupriediaz@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
2025-07-08 13:27:42 +01:00
Ada Couprie Diaz
0ac7584c08 arm64: debug: split single stepping exception entry
Currently all debug exceptions share common entry code and are routed
to `do_debug_exception()`, which calls dynamically-registered
handlers for each specific debug exception. This is unfortunate as
different debug exceptions have different entry handling requirements,
and it would be better to handle these distinct requirements earlier.

The single stepping exception has the most constraints : it can be
exploited to train branch predictors and it needs special handling at EL1
for the Cortex-A76 erratum #1463225. We need to conserve all those
mitigations.
However, it does not write an address at FAR_EL1, as only hardware
watchpoints do so.

The single-step handler does its own signaling if it needs to and only
returns 0, so we can call it directly from `entry-common.c`.

Split the single stepping exception entry, adjust the function signature,
keep the security mitigation and erratum handling.
Further, as the EL0 and EL1 code paths are cleanly separated, we can split
`do_softstep()` into `do_el0_softstep()` and `do_el1_softstep()` and
call them directly from the relevant entry paths.
We can also remove `NOKPROBE_SYMBOL` for the EL0 path, as it cannot
lead to a kprobe recursion.

Move the call to `arm64_apply_bp_hardening()` to `entry-common.c` so that
we can do it as early as possible, and only for the exceptions coming
from EL0, where it is needed.
This is safe to do as it is `noinstr`, as are all the functions it
may call. `el0_ia()` and `el0_pc()` already call it this way.

When taking a soft-step exception from EL0, most of the single stepping
handling is safely preemptible : the only possible handler is
`uprobe_single_step_handler()`. It only operates on task-local data and
properly checks its validity, then raises a Thread Information Flag,
processed before returning to userspace in `do_notify_resume()`, which
is already preemptible.
However, the soft-step handler first calls `reinstall_suspended_bps()`
to check if there is any hardware breakpoint or watchpoint pending
or already stepped through.
This cannot be preempted as it manipulates the hardware breakpoint and
watchpoint registers.

Move the call to `try_step_suspended_breakpoints()` to `entry-common.c`
and adjust the relevant comments.
We can now safely unmask interrupts before handling the step itself,
fixing a PREEMPT_RT issue where the handler could call a sleeping function
with preemption disabled.

Signed-off-by: Ada Couprie Diaz <ada.coupriediaz@arm.com>
Closes: https://lore.kernel.org/linux-arm-kernel/Z6YW_Kx4S2tmj2BP@uudg.org/
Tested-by: Luis Claudio R. Goncalves <lgoncalv@redhat.com>
Reviewed-by: Will Deacon <will@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20250707114109.35672-10-ada.coupriediaz@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
2025-07-08 13:27:42 +01:00
Ada Couprie Diaz
80691d3552 arm64: debug: refactor reinstall_suspended_bps()
`reinstall_suspended_bps()` plays a key part in the stepping process
when we have hardware breakpoints and watchpoints enabled.
It checks if we need to step one, will re-enable it if it has
been handled and will return whether or not we need to proceed with
a single-step.

However, the current naming and return values make it harder to understand
the logic and goal of the function.

Rename it `try_step_suspended_breakpoints()` and change the return value
to a boolean, aligning it with similar functions used in
`do_el0_undef()` like `try_emulate_mrs()`, and making its behaviour
more obvious.

Signed-off-by: Ada Couprie Diaz <ada.coupriediaz@arm.com>
Tested-by: Luis Claudio R. Goncalves <lgoncalv@redhat.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Will Deacon <will@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20250707114109.35672-9-ada.coupriediaz@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
2025-07-08 13:27:42 +01:00
Ada Couprie Diaz
43e2ae77fc arm64: debug: split hardware breakpoint exception entry
Currently all debug exceptions share common entry code and are routed
to `do_debug_exception()`, which calls dynamically-registered
handlers for each specific debug exception. This is unfortunate as
different debug exceptions have different entry handling requirements,
and it would be better to handle these distinct requirements earlier.

Hardware breakpoints exceptions are generated by the hardware after user
configuration. As such, they can be exploited when training branch
predictors outside of the userspace VA range: they still need to call
`arm64_apply_bp_hardening()` if needed to mitigate against this attack.

However, they do not need to handle the Cortex-A76 erratum #1463225 as
it only applies to single stepping exceptions.
It does not set an address in FAR_EL1 either, only the hardware
watchpoint does.

As the hardware breakpoint handler only returns 0 and never triggers
the call to `arm64_notify_die()`, we can call it directly from
`entry-common.c`.
Split the hardware breakpoint exception entry, adjust
the function signature, and handling of the Cortex-A76 erratum to fit
the behaviour of the exception.

Move the call to `arm64_apply_bp_hardening()` to `entry-common.c` so that
we can do it as early as possible, and only for the exceptions coming
from EL0, where it is needed.
This is safe to do as it is `noinstr`, as are all the functions it
may call. `el0_ia()` and `el0_pc()` already call it this way.

Signed-off-by: Ada Couprie Diaz <ada.coupriediaz@arm.com>
Tested-by: Luis Claudio R. Goncalves <lgoncalv@redhat.com>
Reviewed-by: Will Deacon <will@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20250707114109.35672-8-ada.coupriediaz@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
2025-07-08 13:27:41 +01:00
Ada Couprie Diaz
eaff68b328 arm64: entry: Add entry and exit functions for debug exceptions
Move the `debug_exception_enter()` and `debug_exception_exit()`
functions from mm/fault.c, as they are needed to split
the debug exceptions entry paths from the current unified one.

Make them externally visible in include/asm/exception.h until
the caller in mm/fault.c is cleaned up.

Signed-off-by: Ada Couprie Diaz <ada.coupriediaz@arm.com>
Tested-by: Luis Claudio R. Goncalves <lgoncalv@redhat.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Will Deacon <will@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20250707114109.35672-7-ada.coupriediaz@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
2025-07-08 13:27:41 +01:00
Ada Couprie Diaz
d4e0b12620 arm64: debug: remove break/step handler registration infrastructure
Remove all infrastructure for the dynamic registration previously used by
software breakpoints and stepping handlers.

Signed-off-by: Ada Couprie Diaz <ada.coupriediaz@arm.com>
Tested-by: Luis Claudio R. Goncalves <lgoncalv@redhat.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Will Deacon <will@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20250707114109.35672-6-ada.coupriediaz@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
2025-07-08 13:27:41 +01:00
Ada Couprie Diaz
403b48aad5 arm64: debug: call step handlers statically
Software stepping checks for the correct handler by iterating over a list
of dynamically registered handlers and calling all of them until one
handles the exception.

This is the only generic way to handle software stepping handlers in arm64
as the exception does not provide an immediate that could be checked,
contrary to software breakpoints.

However, the registration mechanism is not exported and has only
two current users : the KGDB stepping handler, and the uprobe single step
handler.
Given that one comes from user mode and the other from kernel mode, call
the appropriate one by checking the source EL of the exception.
Add a stand-in that returns DBG_HOOK_ERROR when the configuration
options are not enabled.

Remove `arch_init_uprobes()` as it is not useful anymore and is
specific to arm64.

Unify the naming of the handler to XXX_single_step_handler(), making it
clear they are related.

Signed-off-by: Ada Couprie Diaz <ada.coupriediaz@arm.com>
Tested-by: Luis Claudio R. Goncalves <lgoncalv@redhat.com>
Reviewed-by: Will Deacon <will@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20250707114109.35672-5-ada.coupriediaz@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
2025-07-08 13:27:41 +01:00
Ada Couprie Diaz
6adfdc5e2e arm64: debug: call software breakpoint handlers statically
Software breakpoints pass an immediate value in ESR ("comment") that can
be used to call a specialized handler (KGDB, KASAN...).
We do so in two different ways :
 - During early boot, `early_brk64` statically checks against known
   immediates and calls the corresponding handler,
 - During init, handlers are dynamically registered into a list. When
   called, the generic software breakpoint handler will iterate over
   the list to find the appropriate handler.

The dynamic registration does not provide any benefit here as it is not
exported and all its uses are within the arm64 tree. It also depends on an
RCU list, whose safe access currently relies on the non-preemptible state
of `do_debug_exception`.

Replace the list iteration logic in `call_break_hooks` to call
the breakpoint handlers statically if they are enabled, like in
`early_brk64`.
Expose the handlers in their respective headers to be reachable from
`arch/arm64/kernel/debug-monitors.c` at link time.

Unify the naming of the software breakpoint handlers to XXX_brk_handler(),
making it clear they are related and to differentiate from the
hardware breakpoints.

Signed-off-by: Ada Couprie Diaz <ada.coupriediaz@arm.com>
Tested-by: Luis Claudio R. Goncalves <lgoncalv@redhat.com>
Reviewed-by: Will Deacon <will@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20250707114109.35672-4-ada.coupriediaz@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
2025-07-08 13:27:41 +01:00
Ada Couprie Diaz
b1e2d95524 arm64: refactor aarch32_break_handler()
`aarch32_break_handler()` is called in `do_el0_undef()` when we
are trying to handle an exception whose Exception Syndrome is unknown.
It checks if the instruction hit might be a 32-bit arm break (be it
A32 or T2), and sends a SIGTRAP to userspace if it is so that it can
be handled.

However, this is badly represented in the naming of the function, and
is not consistent with the other functions called with the same logic
in `do_el0_undef()`.

Rename it `try_handle_aarch32_break()` and change the return value to
a boolean to align with the logic of the other tentative handlers in
`do_el0_undef()`, the previous error code being ignored anyway.

Signed-off-by: Ada Couprie Diaz <ada.coupriediaz@arm.com>
Tested-by: Luis Claudio R. Goncalves <lgoncalv@redhat.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20250707114109.35672-3-ada.coupriediaz@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
2025-07-08 13:27:41 +01:00
Ada Couprie Diaz
ad8b22648b arm64: debug: clean up single_step_handler logic
Remove the unnecessary boolean which always checks if the handler was found
and return early instead.

Signed-off-by: Ada Couprie Diaz <ada.coupriediaz@arm.com>
Tested-by: Luis Claudio R. Goncalves <lgoncalv@redhat.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20250707114109.35672-2-ada.coupriediaz@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
2025-07-08 13:27:41 +01:00
Kevin Brodsky
22f3a4f608 arm64: poe: Handle spurious Overlay faults
We do not currently issue an ISB after updating POR_EL0 when
context-switching it, for instance. The rationale is that if the old
value of POR_EL0 is more restrictive and causes a fault during
uaccess, the access will be retried [1]. In other words, we are
trading an ISB on every context-switching for the (unlikely)
possibility of a spurious fault. We may also miss faults if the new
value of POR_EL0 is more restrictive, but that's considered
acceptable.

However, as things stand, a spurious Overlay fault results in
uaccess failing right away since it causes fault_from_pkey() to
return true. If an Overlay fault is reported, we therefore need to
double check POR_EL0 against vma_pkey(vma) - this is what
arch_vma_access_permitted() already does.

As it turns out, we already perform that explicit check if no
Overlay fault is reported, and we need to keep that check (see
comment added in fault_from_pkey()). Net result: the Overlay ISS2
bit isn't of much help to decide whether a pkey fault occurred.

Remove the check for the Overlay bit from fault_from_pkey() and
add a comment to try and explain the situation. While at it, also
add a comment to permission_overlay_switch() in case anyone gets
surprised by the lack of ISB.

[1] https://lore.kernel.org/linux-arm-kernel/ZtYNGBrcE-j35fpw@arm.com/

Fixes: 160a8e13de ("arm64: context switch POR_EL0 register")
Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com>
Link: https://lore.kernel.org/r/20250619160042.2499290-2-kevin.brodsky@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
2025-07-04 16:40:38 +01:00
Mark Brown
a75ad2fc76 arm64: Filter out SME hwcaps when FEAT_SME isn't implemented
We have a number of hwcaps for various SME subfeatures enumerated via
ID_AA64SMFR0_EL1. Currently we advertise these without cross checking
against the main SME feature, advertised in ID_AA64PFR1_EL1.SME which
means that if the two are out of sync userspace can see a confusing
situation where SME subfeatures are advertised without the base SME
hwcap. This can be readily triggered by using the arm64.nosme override
which only masks out ID_AA64PFR1_EL1.SME, and there have also been
reports of VMMs which do the same thing.

Fix this as we did previously for SVE in 064737920b ("arm64: Filter
out SVE hwcaps when FEAT_SVE isn't implemented") by filtering out the
SME subfeature hwcaps when FEAT_SME is not present.

Fixes: 5e64b862c4 ("arm64/sme: Basic enumeration support")
Reported-by: Yury Khrustalev <yury.khrustalev@arm.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20250620-arm64-sme-filter-hwcaps-v1-1-02b9d3c2d8ef@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
2025-07-04 16:35:30 +01:00
Arnd Bergmann
6c66bb655c arm64: move smp_send_stop() cpu mask off stack
For really large values of CONFIG_NR_CPUS, a CPU mask value should
not be put on the stack:

arch/arm64/kernel/smp.c:1188:1: error: the frame size of 8544 bytes is larger than 1536 bytes [-Werror=frame-larger-than=]

This could be achieved using alloc_cpumask_var(), which makes it
depend on CONFIG_CPUMASK_OFFSTACK, but as this function is already
serialized and can only run on one CPU, making the variable 'static'
is easier.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20250620111045.3364827-1-arnd@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
2025-07-04 16:32:15 +01:00
Marc Zyngier
727c2a53cf arm64: Unconditionally select CONFIG_JUMP_LABEL
Aneesh reports that his kernel fails to boot in nVHE mode with
KVM's protected mode enabled. Further investigation by Mostafa
reveals that this fails because CONFIG_JUMP_LABEL=n and that
we have static keys shared between EL1 and EL2.

While this can be worked around, it is obvious that we have long
relied on having CONFIG_JUMP_LABEL enabled at all times, as all
supported compilers now have 'asm goto' (which is the basic block
for jump labels).

Let's simplify our lives once and for all by mandating jump labels.
It's not like anyone else is testing anything without them, and
we already rely on them for other things (kfence, xfs, preempt).

Link: https://lore.kernel.org/r/yq5ah60pkq03.fsf@kernel.org
Reported-by: Aneesh Kumar K.V <aneesh.kumar@kernel.org>
Reported-by: Mostafa Saleh <smostafa@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Cc: Will Deacon <will@kernel.org>
Cc: Catalin marinas <catalin.marinas@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20250613141936.2219895-1-maz@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
2025-07-04 14:47:51 +01:00
Breno Leitao
ef8923e6c0 arm64: efi: Fix KASAN false positive for EFI runtime stack
KASAN reports invalid accesses during arch_stack_walk() for EFI runtime
services due to vmalloc tagging[1]. The EFI runtime stack must be allocated
with KASAN tags reset to avoid false positives.

This patch uses arch_alloc_vmap_stack() instead of __vmalloc_node() for
EFI stack allocation, which internally calls kasan_reset_tag()

The changes ensure EFI runtime stacks are properly sanitized for KASAN
while maintaining functional consistency.

Link: https://lore.kernel.org/all/aFVVEgD0236LdrL6@gmail.com/ [1]
Suggested-by: Andrey Konovalov <andreyknvl@gmail.com>
Suggested-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Breno Leitao <leitao@debian.org>
Link: https://lore.kernel.org/r/20250704-arm_kasan-v2-1-32ebb4fd7607@debian.org
Signed-off-by: Will Deacon <will@kernel.org>
2025-07-04 14:47:06 +01:00
Yicong Yang
7a884442ae arm64/watchdog_hld: Add a cpufreq notifier for update watchdog thresh
arm64 depends on the cpufreq driver to gain the maximum cpu frequency
to convert the watchdog_thresh to perf event period. cpufreq drivers
like cppc_cpufreq will be initialized lately after the initializing of
the hard lockup detector so just use a safe cpufreq which will be
inaccurency. Use a cpufreq notifier to adjust the event's period to
a more accurate one.

Reviewed-by: Jie Zhan <zhanjie9@hisilicon.com>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Yicong Yang <yangyicong@hisilicon.com>
Link: https://lore.kernel.org/r/20250701110214.27242-3-yangyicong@huawei.com
Signed-off-by: Will Deacon <will@kernel.org>
2025-07-04 13:17:30 +01:00
Anshuman Khandual
d3a80c5109 arm64/debug: Drop redundant DBG_MDSCR_* macros
MDSCR_EL1 has already been defined in tools sysreg format and hence can be
used in all debug monitor related call paths. But using generated sysreg
definitions causes build warnings because there is a mismatch between mdscr
variable (u32) and GENMASK() based masks (long unsigned int). Convert all
variables handling MDSCR_EL1 register as u64 which also reflects its true
width as well.

--------------------------------------------------------------------------
arch/arm64/kernel/debug-monitors.c: In function ‘disable_debug_monitors’:
arch/arm64/kernel/debug-monitors.c:108:13: warning: conversion from ‘long
unsigned int’ to ‘u32’ {aka ‘unsigned int’} changes value from
‘18446744073709518847’ to ‘4294934527’ [-Woverflow]
  108 |   disable = ~MDSCR_EL1_MDE;
      |             ^
--------------------------------------------------------------------------

While here, replace an open encoding with MDSCR_EL1_TDCC in __cpu_setup().

Cc: Will Deacon <will@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Reviewed-by: Ada Couprie Diaz <ada.coupriediaz@arm.com>
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Link: https://lore.kernel.org/r/20250613023646.1215700-2-anshuman.khandual@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2025-07-03 20:00:24 +01:00
Yeoreum Yun
f620372209 arm64/hwcaps: Add MTE_STORE_ONLY hwcaps
Since ARMv8.9, FEAT_MTE_STORE_ONLY can be used to restrict raise of tag
check fault on store operation only.

add MTE_STORE_ONLY hwcaps so that user can use this feature.

Signed-off-by: Yeoreum Yun <yeoreum.yun@arm.com>
Link: https://lore.kernel.org/r/20250618092957.2069907-5-yeoreum.yun@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2025-07-02 18:49:04 +01:00
Yeoreum Yun
4d51ff5bba arm64/kernel: Support store-only mte tag check
Introduce new flag -- MTE_CTRL_STORE_ONLY used to set store-only tag check.
This flag isn't overridden by prefered tcf flag setting but set together
with prefered setting of way to report tag check fault.

Signed-off-by: Yeoreum Yun <yeoreum.yun@arm.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20250618092957.2069907-4-yeoreum.yun@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2025-07-02 18:49:04 +01:00
Yeoreum Yun
33e943a228 arm64/cpufeature: Add MTE_STORE_ONLY feature
Since ARMv8.9, FEAT_MTE_STORE_ONLY can be used to restrict raise of tag
check fault on store operation only.

add MTE_STORE_ONLY feature.

Signed-off-by: Yeoreum Yun <yeoreum.yun@arm.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20250618092957.2069907-2-yeoreum.yun@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2025-07-02 18:49:03 +01:00
Yeoreum Yun
7c7f55039b arm64: Report address tag when FEAT_MTE_TAGGED_FAR is supported
If FEAT_MTE_TAGGED_FAR (Armv8.9) is supported, bits 63:60 of the fault address
are preserved in response to synchronous tag check faults (SEGV_MTESERR).

This patch modifies below to support this feature:
  - Use the original FAR_EL1 value when an MTE tag check fault occurs,
    if ARM64_MTE_FAR is supported so that not only logical tag
    (bits 59:56) but also address tag (bits 63:60] being reported too.

  - Add HWCAP for mtefar to let user know bits 63:60 includes
    address tag information when when FEAT_MTE_TAGGED_FAR is supported.

Applications that require this information should install
a signal handler with the SA_EXPOSE_TAGBITS flag.
While this introduces a minor ABI change,
most applications do not set this flag and therefore will not be affected.

Signed-off-by: Yeoreum Yun <yeoreum.yun@arm.com>
Link: https://lore.kernel.org/r/20250618084513.1761345-3-yeoreum.yun@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2025-07-02 17:44:17 +01:00
Yeoreum Yun
6698453689 arm64/cpufeature: Add FEAT_MTE_TAGGED_FAR feature
Add FEAT_MTE_TAGGED_FAR cpucap which makes FAR_ELx report
all non-address bits on a synchronous MTE tag check fault since Armv8.9

Signed-off-by: Yeoreum Yun <yeoreum.yun@arm.com>
Acked-by: Yury Khrustalev <yury.khrustalev@arm.com>
Link: https://lore.kernel.org/r/20250618084513.1761345-2-yeoreum.yun@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2025-07-02 17:44:10 +01:00
Song Liu
fd1e0fd71f arm64: Implement HAVE_LIVEPATCH
Allocate a task flag used to represent the patch pending state for the
task. When a livepatch is being loaded or unloaded, the livepatch code
uses this flag to select the proper version of a being patched kernel
functions to use for current task.

In arch/arm64/Kconfig, select HAVE_LIVEPATCH and include proper Kconfig.

This is largely based on [1] by Suraj Jitindar Singh.

[1] https://lore.kernel.org/all/20210604235930.603-1-surajjs@amazon.com/

Cc: Suraj Jitindar Singh <surajjs@amazon.com>
Cc: Torsten Duwe <duwe@suse.de>
Acked-by: Miroslav Benes <mbenes@suse.cz>
Tested-by: Breno Leitao <leitao@debian.org>
Tested-by: Andrea della Porta <andrea.porta@suse.com>
Signed-off-by: Song Liu <song@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20250630174502.842486-1-song@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2025-07-01 15:18:53 +01:00
Li Chen
bad3fa2fb9 ACPI: Suppress misleading SPCR console message when SPCR table is absent
The kernel currently alway prints:
"Use ACPI SPCR as default console: No/Yes "

even on systems that lack an SPCR table. This can
mislead users into thinking the SPCR table exists
on the machines without SPCR.

With this change, the "Yes" is only printed if
the SPCR table is present, parsed and !param_acpi_nospcr.
This avoids user confusion on SPCR-less systems.

Signed-off-by: Li Chen <chenl311@chinatelecom.cn>
Acked-by: Hanjun Guo <guohanjun@huawei.com>
Link: https://lore.kernel.org/r/20250620131309.126555-3-me@linux.beauty
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2025-07-01 15:06:51 +01:00
Masahiro Yamada
6853acd399 arm64: pi: use 'targets' instead of extra-y in Makefile
%.pi.o files are built as prerequisites of other objects.
There is no need to use extra-y, which is planned for deprecation.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Link: https://lore.kernel.org/r/20250602180937.528459-1-masahiroy@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2025-07-01 12:44:38 +01:00
Mikołaj Lenczewski
5aa4b62576 arm64: Add BBM Level 2 cpu feature
The Break-Before-Make cpu feature supports multiple levels (levels 0-2),
and this commit adds a dedicated BBML2 cpufeature to test against
support for.

To support BBML2 in as wide a range of contexts as we can, we want not
only the architectural guarantees that BBML2 makes, but additionally
want BBML2 to not create TLB conflict aborts. Not causing aborts avoids
us having to prove that no recursive faults can be induced in any path
that uses BBML2, allowing its use for arbitrary kernel mappings.

This feature builds on the previous ARM64_CPUCAP_EARLY_LOCAL_CPU_FEATURE,
as all early cpus must support BBML2 for us to enable it (and any later
cpus must also support it to be onlined).

Not onlining late cpus that do not support BBML2 is unavoidable, as we
might currently be using BBML2 semantics for kernel memory regions. This
could cause faults in the late cpus, and would be difficult to unwind,
so let us avoid the case altogether.

Signed-off-by: Mikołaj Lenczewski <miko.lenczewski@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Reviewed-by: Ryan Roberts <ryan.roberts@arm.com>
Link: https://lore.kernel.org/r/20250625113435.26849-3-miko.lenczewski@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2025-06-30 18:09:05 +01:00
Catalin Marinas
3eb06f6ce3 arm64: cpufeature: Introduce MATCH_ALL_EARLY_CPUS capability type
For system-wide capabilities, the kernel has the SCOPE_SYSTEM type. Such
capabilities are checked once the SMP boot has completed using the
sanitised ID registers. However, there is a need for a new capability
type similar in scope to the system one but with checking performed
locally on each CPU during boot (e.g. based on MIDR_EL1 which is not a
sanitised register).

Introduce ARM64_CPUCAP_MATCH_ALL_EARLY_CPUS which, together with
ARM64_CPUCAP_SCOPE_LOCAL_CPU, ensures that such capability is enabled
only if all early CPUs have it. For ease of use, define
ARM64_CPUCAP_EARLY_LOCAL_CPU_FEATURE which combines SCOPE_LOCAL_CPU,
PERMITTED_FOR_LATE_CPUS and MATCH_ALL_EARLY_CPUS.

Signed-off-by: Mikołaj Lenczewski <miko.lenczewski@arm.com>
Reviewed-by: Suzuki K Poulose <Suzuki.Poulose@arm.com>
Link: https://lore.kernel.org/r/20250625113435.26849-2-miko.lenczewski@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2025-06-30 17:42:03 +01:00
Song Liu
805f13e403 arm64: stacktrace: Implement arch_stack_walk_reliable()
Add arch_stack_walk_reliable(), which will be used during kernel live
patching to detect when threads have completed executing old versions of
functions.

Note that arch_stack_walk_reliable() only needs to guarantee that it
returns an error code when it cannot provide a reliable stacktrace. It
is not required to provide a reliable stacktrace in all scenarios so
long as it returns said error code.

At present we can only reliably unwind up to an exception boundary. In
future we should be able to improve this with additional data from the
compiler (e.g. sframe).

Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20250320171559.3423224-2-song@kernel.org
[ Mark: Simplify logic, clarify commit message ]
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Andrea della Porta <andrea.porta@suse.com>
Cc: Breno Leitao <leitao@debian.org>
Cc: Josh Poimboeuf <jpoimboe@kernel.org>
Cc: Miroslav Benes <mbenes@suse.cz>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Song Liu <song@kernel.org>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20250521111000.2237470-3-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2025-06-20 13:10:09 +01:00
Mark Rutland
beecfd6a88 arm64: stacktrace: Check kretprobe_find_ret_addr() return value
If kretprobe_find_ret_addr() fails to find the original return address,
it returns 0. Check for this case so that a reliable stacktrace won't
silently ignore it.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Andrea della Porta <andrea.porta@suse.com>
Cc: Breno Leitao <leitao@debian.org>
Cc: Josh Poimboeuf <jpoimboe@kernel.org>
Cc: Miroslav Benes <mbenes@suse.cz>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Song Liu <song@kernel.org>
Cc: Will Deacon <will@kernel.org>
Reviewed-and-tested-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20250521111000.2237470-2-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2025-06-20 13:10:09 +01:00
Dylan Hatch
91b89a6344 arm64/module: Use text-poke API for late relocations.
To enable late module patching, livepatch modules need to be able to
apply some of their relocations well after being loaded. In this
scenario however, the livepatch module text and data is already RX-only,
so special treatment is needed to make the late relocations possible. To
do this, use the text-poking API for these late relocations.

This patch is partially based off commit 88fc078a7a ("x86/module: Use
text_poke() for late relocations").

Signed-off-by: Dylan Hatch <dylanbhatch@google.com>
Acked-by: Song Liu <song@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20250603223417.3700218-1-dylanbhatch@google.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2025-06-20 13:09:16 +01:00
Tengda Wu
39dfc971e4 arm64/ptrace: Fix stack-out-of-bounds read in regs_get_kernel_stack_nth()
KASAN reports a stack-out-of-bounds read in regs_get_kernel_stack_nth().

Call Trace:
[   97.283505] BUG: KASAN: stack-out-of-bounds in regs_get_kernel_stack_nth+0xa8/0xc8
[   97.284677] Read of size 8 at addr ffff800089277c10 by task 1.sh/2550
[   97.285732]
[   97.286067] CPU: 7 PID: 2550 Comm: 1.sh Not tainted 6.6.0+ #11
[   97.287032] Hardware name: linux,dummy-virt (DT)
[   97.287815] Call trace:
[   97.288279]  dump_backtrace+0xa0/0x128
[   97.288946]  show_stack+0x20/0x38
[   97.289551]  dump_stack_lvl+0x78/0xc8
[   97.290203]  print_address_description.constprop.0+0x84/0x3c8
[   97.291159]  print_report+0xb0/0x280
[   97.291792]  kasan_report+0x84/0xd0
[   97.292421]  __asan_load8+0x9c/0xc0
[   97.293042]  regs_get_kernel_stack_nth+0xa8/0xc8
[   97.293835]  process_fetch_insn+0x770/0xa30
[   97.294562]  kprobe_trace_func+0x254/0x3b0
[   97.295271]  kprobe_dispatcher+0x98/0xe0
[   97.295955]  kprobe_breakpoint_handler+0x1b0/0x210
[   97.296774]  call_break_hook+0xc4/0x100
[   97.297451]  brk_handler+0x24/0x78
[   97.298073]  do_debug_exception+0xac/0x178
[   97.298785]  el1_dbg+0x70/0x90
[   97.299344]  el1h_64_sync_handler+0xcc/0xe8
[   97.300066]  el1h_64_sync+0x78/0x80
[   97.300699]  kernel_clone+0x0/0x500
[   97.301331]  __arm64_sys_clone+0x70/0x90
[   97.302084]  invoke_syscall+0x68/0x198
[   97.302746]  el0_svc_common.constprop.0+0x11c/0x150
[   97.303569]  do_el0_svc+0x38/0x50
[   97.304164]  el0_svc+0x44/0x1d8
[   97.304749]  el0t_64_sync_handler+0x100/0x130
[   97.305500]  el0t_64_sync+0x188/0x190
[   97.306151]
[   97.306475] The buggy address belongs to stack of task 1.sh/2550
[   97.307461]  and is located at offset 0 in frame:
[   97.308257]  __se_sys_clone+0x0/0x138
[   97.308910]
[   97.309241] This frame has 1 object:
[   97.309873]  [48, 184) 'args'
[   97.309876]
[   97.310749] The buggy address belongs to the virtual mapping at
[   97.310749]  [ffff800089270000, ffff800089279000) created by:
[   97.310749]  dup_task_struct+0xc0/0x2e8
[   97.313347]
[   97.313674] The buggy address belongs to the physical page:
[   97.314604] page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x14f69a
[   97.315885] flags: 0x15ffffe00000000(node=1|zone=2|lastcpupid=0xfffff)
[   97.316957] raw: 015ffffe00000000 0000000000000000 dead000000000122 0000000000000000
[   97.318207] raw: 0000000000000000 0000000000000000 00000001ffffffff 0000000000000000
[   97.319445] page dumped because: kasan: bad access detected
[   97.320371]
[   97.320694] Memory state around the buggy address:
[   97.321511]  ffff800089277b00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[   97.322681]  ffff800089277b80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[   97.323846] >ffff800089277c00: 00 00 f1 f1 f1 f1 f1 f1 00 00 00 00 00 00 00 00
[   97.325023]                          ^
[   97.325683]  ffff800089277c80: 00 00 00 00 00 00 00 00 00 f3 f3 f3 f3 f3 f3 f3
[   97.326856]  ffff800089277d00: f3 f3 00 00 00 00 00 00 00 00 00 00 00 00 00 00

This issue seems to be related to the behavior of some gcc compilers and
was also fixed on the s390 architecture before:

 commit d93a855c31 ("s390/ptrace: Avoid KASAN false positives in regs_get_kernel_stack_nth()")

As described in that commit, regs_get_kernel_stack_nth() has confirmed that
`addr` is on the stack, so reading the value at `*addr` should be allowed.
Use READ_ONCE_NOCHECK() helper to silence the KASAN check for this case.

Fixes: 0a8ea52c3e ("arm64: Add HAVE_REGS_AND_STACK_ACCESS_API feature")
Signed-off-by: Tengda Wu <wutengda@huaweicloud.com>
Link: https://lore.kernel.org/r/20250604005533.1278992-1-wutengda@huaweicloud.com
[will: Use '*addr' as the argument to READ_ONCE_NOCHECK()]
Signed-off-by: Will Deacon <will@kernel.org>
2025-06-12 17:28:18 +01:00
Mark Brown
d2be3270f4 arm64/gcs: Don't call gcs_free() during flush_gcs()
Currently we call gcs_free() during flush_gcs() to reset the thread
state for GCS. This includes unmapping any kernel allocated GCS, but
this is redundant when doing a flush_thread() since we are
reinitialising the thread memory too. Inline the reinitialisation of the
thread struct.

Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20250611-arm64-gcs-flush-thread-v1-1-cc26feeddabd@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
2025-06-12 17:18:01 +01:00
Linus Torvalds
8630c59e99 Kbuild updates for v6.16
- Add support for the EXPORT_SYMBOL_GPL_FOR_MODULES() macro, which exports a
    symbol only to specified modules
 
  - Improve ABI handling in gendwarfksyms
 
  - Forcibly link lib-y objects to vmlinux even if CONFIG_MODULES=n
 
  - Add checkers for redundant or missing <linux/export.h> inclusion
 
  - Deprecate the extra-y syntax
 
  - Fix a genksyms bug when including enum constants from *.symref files
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Merge tag 'kbuild-v6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild updates from Masahiro Yamada:

 - Add support for the EXPORT_SYMBOL_GPL_FOR_MODULES() macro, which
   exports a symbol only to specified modules

 - Improve ABI handling in gendwarfksyms

 - Forcibly link lib-y objects to vmlinux even if CONFIG_MODULES=n

 - Add checkers for redundant or missing <linux/export.h> inclusion

 - Deprecate the extra-y syntax

 - Fix a genksyms bug when including enum constants from *.symref files

* tag 'kbuild-v6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (28 commits)
  genksyms: Fix enum consts from a reference affecting new values
  arch: use always-$(KBUILD_BUILTIN) for vmlinux.lds
  kbuild: set y instead of 1 to KBUILD_{BUILTIN,MODULES}
  efi/libstub: use 'targets' instead of extra-y in Makefile
  module: make __mod_device_table__* symbols static
  scripts/misc-check: check unnecessary #include <linux/export.h> when W=1
  scripts/misc-check: check missing #include <linux/export.h> when W=1
  scripts/misc-check: add double-quotes to satisfy shellcheck
  kbuild: move W=1 check for scripts/misc-check to top-level Makefile
  scripts/tags.sh: allow to use alternative ctags implementation
  kconfig: introduce menu type enum
  docs: symbol-namespaces: fix reST warning with literal block
  kbuild: link lib-y objects to vmlinux forcibly even when CONFIG_MODULES=n
  tinyconfig: enable CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
  docs/core-api/symbol-namespaces: drop table of contents and section numbering
  modpost: check forbidden MODULE_IMPORT_NS("module:") at compile time
  kbuild: move kbuild syntax processing to scripts/Makefile.build
  Makefile: remove dependency on archscripts for header installation
  Documentation/kbuild: Add new gendwarfksyms kABI rules
  Documentation/kbuild: Drop section numbers
  ...
2025-06-07 10:05:35 -07:00
Masahiro Yamada
e21efe833e arch: use always-$(KBUILD_BUILTIN) for vmlinux.lds
The extra-y syntax is deprecated. Instead, use always-$(KBUILD_BUILTIN),
which behaves equivalently.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Reviewed-by: Nicolas Schier <n.schier@avm.de>
2025-06-07 14:38:07 +09:00
Linus Torvalds
e9e668cd27 arm64 fixes for -rc1
- Disable problematic linker assertions for broken versions of LLD.
 
 - Work around sporadic link failure with LLD and various randconfig
   builds.
 
 - Fix missing invalidation in the TLB batching code when reclaim races
   with mprotect() and friends.
 
 - Add a command-line override for MPAM to allow booting on systems with
   broken firmware.
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Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 fixes from Will Deacon:
 "We've got a couple of build fixes when using LLD, a missing TLB
  invalidation and a workaround for broken firmware on SoCs with CPUs
  that implement MPAM:

   - Disable problematic linker assertions for broken versions of LLD

   - Work around sporadic link failure with LLD and various randconfig
     builds

   - Fix missing invalidation in the TLB batching code when reclaim
     races with mprotect() and friends

   - Add a command-line override for MPAM to allow booting on systems
     with broken firmware"

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: Add override for MPAM
  arm64/mm: Close theoretical race where stale TLB entry remains valid
  arm64: Work around convergence issue with LLD linker
  arm64: Disable LLD linker ASSERT()s for the time being
2025-06-05 11:39:17 -07:00
Xi Ruoyao
10f885d63a arm64: Add override for MPAM
As the message of the commit 09e6b306f3 ("arm64: cpufeature: discover
CPU support for MPAM") already states, if a buggy firmware fails to
either enable MPAM or emulate the trap as if it were disabled, the
kernel will just fail to boot.  While upgrading the firmware should be
the best solution, we have some hardware of which the vendor have made
no response 2 months after we requested a firmware update.  Allow
overriding it so our devices don't become some e-waste.

Cc: James Morse <james.morse@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Will Deacon <will@kernel.org>
Cc: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Cc: Mingcong Bai <jeffbai@aosc.io>
Cc: Shaopeng Tan <tan.shaopeng@fujitsu.com>
Cc: Ben Horgan <ben.horgan@arm.com>
Signed-off-by: Xi Ruoyao <xry111@xry111.site>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20250602043723.216338-1-xry111@xry111.site
Signed-off-by: Will Deacon <will@kernel.org>
2025-06-02 13:49:09 +01:00
Ard Biesheuvel
dc0a083948 arm64: Work around convergence issue with LLD linker
LLD will occasionally error out with a '__init_end does not converge'
error if INIT_IDMAP_DIR_SIZE is defined in terms of _end, as this
results in a circular dependency.

Counter this by dimensioning the initial IDMAP page tables based on a
new boundary marker 'kimage_limit', and define it such that its value
should not change as a result of the initdata segment being pushed over
a 64k segment boundary due to changes in INIT_IDMAP_DIR_SIZE, provided
that its value doesn't change by more than 2M between linker passes.

Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20250531123005.3866382-2-ardb+git@google.com
Signed-off-by: Will Deacon <will@kernel.org>
2025-06-02 12:53:18 +01:00
Ard Biesheuvel
e21560b7d3 arm64: Disable LLD linker ASSERT()s for the time being
It turns out [1] that the way LLD handles ASSERT()s in the linker script
can result in spurious failures, so disable them for the newly
introduced BSS symbol export checks. Since we're not aware of any issues
with the existing assertions in vmlinux.lds.S, leave those alone for now
so that they can continue to provide useful coverage.

A linker fix [2] is due to land in version 21 of LLD.

Link: https://lore.kernel.org/r/202505261019.OUlitN6m-lkp@intel.com [1]
Link: https://github.com/llvm/llvm-project/commit/5859863bab7f [2]
Link: https://github.com/ClangBuiltLinux/linux/issues/2094
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Tested-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202505261019.OUlitN6m-lkp@intel.com/
Link: https://lore.kernel.org/r/20250529073507.2984959-2-ardb+git@google.com
Signed-off-by: Will Deacon <will@kernel.org>
2025-06-02 12:49:22 +01:00
Linus Torvalds
00c010e130 - The 11 patch series "Add folio_mk_pte()" from Matthew Wilcox
simplifies the act of creating a pte which addresses the first page in a
   folio and reduces the amount of plumbing which architecture must
   implement to provide this.
 
 - The 8 patch series "Misc folio patches for 6.16" from Matthew Wilcox
   is a shower of largely unrelated folio infrastructure changes which
   clean things up and better prepare us for future work.
 
 - The 3 patch series "memory,x86,acpi: hotplug memory alignment
   advisement" from Gregory Price adds early-init code to prevent x86 from
   leaving physical memory unused when physical address regions are not
   aligned to memory block size.
 
 - The 2 patch series "mm/compaction: allow more aggressive proactive
   compaction" from Michal Clapinski provides some tuning of the (sadly,
   hard-coded (more sadly, not auto-tuned)) thresholds for our invokation
   of proactive compaction.  In a simple test case, the reduction of a guest
   VM's memory consumption was dramatic.
 
 - The 8 patch series "Minor cleanups and improvements to swap freeing
   code" from Kemeng Shi provides some code cleaups and a small efficiency
   improvement to this part of our swap handling code.
 
 - The 6 patch series "ptrace: introduce PTRACE_SET_SYSCALL_INFO API"
   from Dmitry Levin adds the ability for a ptracer to modify syscalls
   arguments.  At this time we can alter only "system call information that
   are used by strace system call tampering, namely, syscall number,
   syscall arguments, and syscall return value.
 
   This series should have been incorporated into mm.git's "non-MM"
   branch, but I goofed.
 
 - The 3 patch series "fs/proc: extend the PAGEMAP_SCAN ioctl to report
   guard regions" from Andrei Vagin extends the info returned by the
   PAGEMAP_SCAN ioctl against /proc/pid/pagemap.  This permits CRIU to more
   efficiently get at the info about guard regions.
 
 - The 2 patch series "Fix parameter passed to page_mapcount_is_type()"
   from Gavin Shan implements that fix.  No runtime effect is expected
   because validate_page_before_insert() happens to fix up this error.
 
 - The 3 patch series "kernel/events/uprobes: uprobe_write_opcode()
   rewrite" from David Hildenbrand basically brings uprobe text poking into
   the current decade.  Remove a bunch of hand-rolled implementation in
   favor of using more current facilities.
 
 - The 3 patch series "mm/ptdump: Drop assumption that pxd_val() is u64"
   from Anshuman Khandual provides enhancements and generalizations to the
   pte dumping code.  This might be needed when 128-bit Page Table
   Descriptors are enabled for ARM.
 
 - The 12 patch series "Always call constructor for kernel page tables"
   from Kevin Brodsky "ensures that the ctor/dtor is always called for
   kernel pgtables, as it already is for user pgtables".  This permits the
   addition of more functionality such as "insert hooks to protect page
   tables".  This change does result in various architectures performing
   unnecesary work, but this is fixed up where it is anticipated to occur.
 
 - The 9 patch series "Rust support for mm_struct, vm_area_struct, and
   mmap" from Alice Ryhl adds plumbing to permit Rust access to core MM
   structures.
 
 - The 3 patch series "fix incorrectly disallowed anonymous VMA merges"
   from Lorenzo Stoakes takes advantage of some VMA merging opportunities
   which we've been missing for 15 years.
 
 - The 4 patch series "mm/madvise: batch tlb flushes for MADV_DONTNEED
   and MADV_FREE" from SeongJae Park optimizes process_madvise()'s TLB
   flushing.  Instead of flushing each address range in the provided iovec,
   we batch the flushing across all the iovec entries.  The syscall's cost
   was approximately halved with a microbenchmark which was designed to
   load this particular operation.
 
 - The 6 patch series "Track node vacancy to reduce worst case allocation
   counts" from Sidhartha Kumar makes the maple tree smarter about its node
   preallocation.  stress-ng mmap performance increased by single-digit
   percentages and the amount of unnecessarily preallocated memory was
   dramaticelly reduced.
 
 - The 3 patch series "mm/gup: Minor fix, cleanup and improvements" from
   Baoquan He removes a few unnecessary things which Baoquan noted when
   reading the code.
 
 - The 3 patch series ""Enhance sysfs handling for memory hotplug in
   weighted interleave" from Rakie Kim "enhances the weighted interleave
   policy in the memory management subsystem by improving sysfs handling,
   fixing memory leaks, and introducing dynamic sysfs updates for memory
   hotplug support".  Fixes things on error paths which we are unlikely to
   hit.
 
 - The 7 patch series "mm/damon: auto-tune DAMOS for NUMA setups
   including tiered memory" from SeongJae Park introduces new DAMOS quota
   goal metrics which eliminate the manual tuning which is required when
   utilizing DAMON for memory tiering.
 
 - The 5 patch series "mm/vmalloc.c: code cleanup and improvements" from
   Baoquan He provides cleanups and small efficiency improvements which
   Baoquan found via code inspection.
 
 - The 2 patch series "vmscan: enforce mems_effective during demotion"
   from Gregory Price "changes reclaim to respect cpuset.mems_effective
   during demotion when possible".  because "presently, reclaim explicitly
   ignores cpuset.mems_effective when demoting, which may cause the cpuset
   settings to violated." "This is useful for isolating workloads on a
   multi-tenant system from certain classes of memory more consistently."
 
 - The 2 patch series ""Clean up split_huge_pmd_locked() and remove
   unnecessary folio pointers" from Gavin Guo provides minor cleanups and
   efficiency gains in in the huge page splitting and migrating code.
 
 - The 3 patch series "Use kmem_cache for memcg alloc" from Huan Yang
   creates a slab cache for `struct mem_cgroup', yielding improved memory
   utilization.
 
 - The 4 patch series "add max arg to swappiness in memory.reclaim and
   lru_gen" from Zhongkun He adds a new "max" argument to the "swappiness="
   argument for memory.reclaim MGLRU's lru_gen.  This directs proactive
   reclaim to reclaim from only anon folios rather than file-backed folios.
 
 - The 17 patch series "kexec: introduce Kexec HandOver (KHO)" from Mike
   Rapoport is the first step on the path to permitting the kernel to
   maintain existing VMs while replacing the host kernel via file-based
   kexec.  At this time only memblock's reserve_mem is preserved.
 
 - The 7 patch series "mm: Introduce for_each_valid_pfn()" from David
   Woodhouse provides and uses a smarter way of looping over a pfn range.
   By skipping ranges of invalid pfns.
 
 - The 2 patch series "sched/numa: Skip VMA scanning on memory pinned to
   one NUMA node via cpuset.mems" from Libo Chen removes a lot of pointless
   VMA scanning when a task is pinned a single NUMA mode.  Dramatic
   performance benefits were seen in some real world cases.
 
 - The 2 patch series "JFS: Implement migrate_folio for
   jfs_metapage_aops" from Shivank Garg addresses a warning which occurs
   during memory compaction when using JFS.
 
 - The 4 patch series "move all VMA allocation, freeing and duplication
   logic to mm" from Lorenzo Stoakes moves some VMA code from kernel/fork.c
   into the more appropriate mm/vma.c.
 
 - The 6 patch series "mm, swap: clean up swap cache mapping helper" from
   Kairui Song provides code consolidation and cleanups related to the
   folio_index() function.
 
 - The 2 patch series "mm/gup: Cleanup memfd_pin_folios()" from Vishal
   Moola does that.
 
 - The 8 patch series "memcg: Fix test_memcg_min/low test failures" from
   Waiman Long addresses some bogus failures which are being reported by
   the test_memcontrol selftest.
 
 - The 3 patch series "eliminate mmap() retry merge, add .mmap_prepare
   hook" from Lorenzo Stoakes commences the deprecation of
   file_operations.mmap() in favor of the new
   file_operations.mmap_prepare().  The latter is more restrictive and
   prevents drivers from messing with things in ways which, amongst other
   problems, may defeat VMA merging.
 
 - The 4 patch series "memcg: decouple memcg and objcg stocks"" from
   Shakeel Butt decouples the per-cpu memcg charge cache from the objcg's
   one.  This is a step along the way to making memcg and objcg charging
   NMI-safe, which is a BPF requirement.
 
 - The 6 patch series "mm/damon: minor fixups and improvements for code,
   tests, and documents" from SeongJae Park is "yet another batch of
   miscellaneous DAMON changes.  Fix and improve minor problems in code,
   tests and documents."
 
 - The 7 patch series "memcg: make memcg stats irq safe" from Shakeel
   Butt converts memcg stats to be irq safe.  Another step along the way to
   making memcg charging and stats updates NMI-safe, a BPF requirement.
 
 - The 4 patch series "Let unmap_hugepage_range() and several related
   functions take folio instead of page" from Fan Ni provides folio
   conversions in the hugetlb code.
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Merge tag 'mm-stable-2025-05-31-14-50' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:

 - "Add folio_mk_pte()" from Matthew Wilcox simplifies the act of
   creating a pte which addresses the first page in a folio and reduces
   the amount of plumbing which architecture must implement to provide
   this.

 - "Misc folio patches for 6.16" from Matthew Wilcox is a shower of
   largely unrelated folio infrastructure changes which clean things up
   and better prepare us for future work.

 - "memory,x86,acpi: hotplug memory alignment advisement" from Gregory
   Price adds early-init code to prevent x86 from leaving physical
   memory unused when physical address regions are not aligned to memory
   block size.

 - "mm/compaction: allow more aggressive proactive compaction" from
   Michal Clapinski provides some tuning of the (sadly, hard-coded (more
   sadly, not auto-tuned)) thresholds for our invokation of proactive
   compaction. In a simple test case, the reduction of a guest VM's
   memory consumption was dramatic.

 - "Minor cleanups and improvements to swap freeing code" from Kemeng
   Shi provides some code cleaups and a small efficiency improvement to
   this part of our swap handling code.

 - "ptrace: introduce PTRACE_SET_SYSCALL_INFO API" from Dmitry Levin
   adds the ability for a ptracer to modify syscalls arguments. At this
   time we can alter only "system call information that are used by
   strace system call tampering, namely, syscall number, syscall
   arguments, and syscall return value.

   This series should have been incorporated into mm.git's "non-MM"
   branch, but I goofed.

 - "fs/proc: extend the PAGEMAP_SCAN ioctl to report guard regions" from
   Andrei Vagin extends the info returned by the PAGEMAP_SCAN ioctl
   against /proc/pid/pagemap. This permits CRIU to more efficiently get
   at the info about guard regions.

 - "Fix parameter passed to page_mapcount_is_type()" from Gavin Shan
   implements that fix. No runtime effect is expected because
   validate_page_before_insert() happens to fix up this error.

 - "kernel/events/uprobes: uprobe_write_opcode() rewrite" from David
   Hildenbrand basically brings uprobe text poking into the current
   decade. Remove a bunch of hand-rolled implementation in favor of
   using more current facilities.

 - "mm/ptdump: Drop assumption that pxd_val() is u64" from Anshuman
   Khandual provides enhancements and generalizations to the pte dumping
   code. This might be needed when 128-bit Page Table Descriptors are
   enabled for ARM.

 - "Always call constructor for kernel page tables" from Kevin Brodsky
   ensures that the ctor/dtor is always called for kernel pgtables, as
   it already is for user pgtables.

   This permits the addition of more functionality such as "insert hooks
   to protect page tables". This change does result in various
   architectures performing unnecesary work, but this is fixed up where
   it is anticipated to occur.

 - "Rust support for mm_struct, vm_area_struct, and mmap" from Alice
   Ryhl adds plumbing to permit Rust access to core MM structures.

 - "fix incorrectly disallowed anonymous VMA merges" from Lorenzo
   Stoakes takes advantage of some VMA merging opportunities which we've
   been missing for 15 years.

 - "mm/madvise: batch tlb flushes for MADV_DONTNEED and MADV_FREE" from
   SeongJae Park optimizes process_madvise()'s TLB flushing.

   Instead of flushing each address range in the provided iovec, we
   batch the flushing across all the iovec entries. The syscall's cost
   was approximately halved with a microbenchmark which was designed to
   load this particular operation.

 - "Track node vacancy to reduce worst case allocation counts" from
   Sidhartha Kumar makes the maple tree smarter about its node
   preallocation.

   stress-ng mmap performance increased by single-digit percentages and
   the amount of unnecessarily preallocated memory was dramaticelly
   reduced.

 - "mm/gup: Minor fix, cleanup and improvements" from Baoquan He removes
   a few unnecessary things which Baoquan noted when reading the code.

 - ""Enhance sysfs handling for memory hotplug in weighted interleave"
   from Rakie Kim "enhances the weighted interleave policy in the memory
   management subsystem by improving sysfs handling, fixing memory
   leaks, and introducing dynamic sysfs updates for memory hotplug
   support". Fixes things on error paths which we are unlikely to hit.

 - "mm/damon: auto-tune DAMOS for NUMA setups including tiered memory"
   from SeongJae Park introduces new DAMOS quota goal metrics which
   eliminate the manual tuning which is required when utilizing DAMON
   for memory tiering.

 - "mm/vmalloc.c: code cleanup and improvements" from Baoquan He
   provides cleanups and small efficiency improvements which Baoquan
   found via code inspection.

 - "vmscan: enforce mems_effective during demotion" from Gregory Price
   changes reclaim to respect cpuset.mems_effective during demotion when
   possible. because presently, reclaim explicitly ignores
   cpuset.mems_effective when demoting, which may cause the cpuset
   settings to violated.

   This is useful for isolating workloads on a multi-tenant system from
   certain classes of memory more consistently.

 - "Clean up split_huge_pmd_locked() and remove unnecessary folio
   pointers" from Gavin Guo provides minor cleanups and efficiency gains
   in in the huge page splitting and migrating code.

 - "Use kmem_cache for memcg alloc" from Huan Yang creates a slab cache
   for `struct mem_cgroup', yielding improved memory utilization.

 - "add max arg to swappiness in memory.reclaim and lru_gen" from
   Zhongkun He adds a new "max" argument to the "swappiness=" argument
   for memory.reclaim MGLRU's lru_gen.

   This directs proactive reclaim to reclaim from only anon folios
   rather than file-backed folios.

 - "kexec: introduce Kexec HandOver (KHO)" from Mike Rapoport is the
   first step on the path to permitting the kernel to maintain existing
   VMs while replacing the host kernel via file-based kexec. At this
   time only memblock's reserve_mem is preserved.

 - "mm: Introduce for_each_valid_pfn()" from David Woodhouse provides
   and uses a smarter way of looping over a pfn range. By skipping
   ranges of invalid pfns.

 - "sched/numa: Skip VMA scanning on memory pinned to one NUMA node via
   cpuset.mems" from Libo Chen removes a lot of pointless VMA scanning
   when a task is pinned a single NUMA mode.

   Dramatic performance benefits were seen in some real world cases.

 - "JFS: Implement migrate_folio for jfs_metapage_aops" from Shivank
   Garg addresses a warning which occurs during memory compaction when
   using JFS.

 - "move all VMA allocation, freeing and duplication logic to mm" from
   Lorenzo Stoakes moves some VMA code from kernel/fork.c into the more
   appropriate mm/vma.c.

 - "mm, swap: clean up swap cache mapping helper" from Kairui Song
   provides code consolidation and cleanups related to the folio_index()
   function.

 - "mm/gup: Cleanup memfd_pin_folios()" from Vishal Moola does that.

 - "memcg: Fix test_memcg_min/low test failures" from Waiman Long
   addresses some bogus failures which are being reported by the
   test_memcontrol selftest.

 - "eliminate mmap() retry merge, add .mmap_prepare hook" from Lorenzo
   Stoakes commences the deprecation of file_operations.mmap() in favor
   of the new file_operations.mmap_prepare().

   The latter is more restrictive and prevents drivers from messing with
   things in ways which, amongst other problems, may defeat VMA merging.

 - "memcg: decouple memcg and objcg stocks"" from Shakeel Butt decouples
   the per-cpu memcg charge cache from the objcg's one.

   This is a step along the way to making memcg and objcg charging
   NMI-safe, which is a BPF requirement.

 - "mm/damon: minor fixups and improvements for code, tests, and
   documents" from SeongJae Park is yet another batch of miscellaneous
   DAMON changes. Fix and improve minor problems in code, tests and
   documents.

 - "memcg: make memcg stats irq safe" from Shakeel Butt converts memcg
   stats to be irq safe. Another step along the way to making memcg
   charging and stats updates NMI-safe, a BPF requirement.

 - "Let unmap_hugepage_range() and several related functions take folio
   instead of page" from Fan Ni provides folio conversions in the
   hugetlb code.

* tag 'mm-stable-2025-05-31-14-50' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (285 commits)
  mm: pcp: increase pcp->free_count threshold to trigger free_high
  mm/hugetlb: convert use of struct page to folio in __unmap_hugepage_range()
  mm/hugetlb: refactor __unmap_hugepage_range() to take folio instead of page
  mm/hugetlb: refactor unmap_hugepage_range() to take folio instead of page
  mm/hugetlb: pass folio instead of page to unmap_ref_private()
  memcg: objcg stock trylock without irq disabling
  memcg: no stock lock for cpu hot-unplug
  memcg: make __mod_memcg_lruvec_state re-entrant safe against irqs
  memcg: make count_memcg_events re-entrant safe against irqs
  memcg: make mod_memcg_state re-entrant safe against irqs
  memcg: move preempt disable to callers of memcg_rstat_updated
  memcg: memcg_rstat_updated re-entrant safe against irqs
  mm: khugepaged: decouple SHMEM and file folios' collapse
  selftests/eventfd: correct test name and improve messages
  alloc_tag: check mem_profiling_support in alloc_tag_init
  Docs/damon: update titles and brief introductions to explain DAMOS
  selftests/damon/_damon_sysfs: read tried regions directories in order
  mm/damon/tests/core-kunit: add a test for damos_set_filters_default_reject()
  mm/damon/paddr: remove unused variable, folio_list, in damon_pa_stat()
  mm/damon/sysfs-schemes: fix wrong comment on damons_sysfs_quota_goal_metric_strs
  ...
2025-05-31 15:44:16 -07:00
Linus Torvalds
724b03ee96 EFI updates for v6.16
- Add support for emitting a .sbat section into the EFI zboot image, so
   that downstreams can easily include revocation metadata in the signed
   EFI images
 
 - Align PE symbolic constant names with other projects
 
 - Bug fix for the efi_test module
 
 - Log the physical address and size of the EFI memory map when failing
   to map it
 
 - A kerneldoc fix for the EFI stub code
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Merge tag 'efi-next-for-v6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi

Pull EFI updates from Ard Biesheuvel:
 "Not a lot going on in the EFI tree this cycle. The only thing that
  stands out is the new support for SBAT metadata, which was a bit
  contentious when it was first proposed, because in the initial
  incarnation, it would have required us to maintain a revocation index,
  and bump it each time a vulnerability affecting UEFI secure boot got
  fixed. This was shot down for obvious reasons.

  This time, only the changes needed to emit the SBAT section into the
  PE/COFF image are being carried upstream, and it is up to the distros
  to decide what to put in there when creating and signing the build.

  This only has the EFI zboot bits (which the distros will be using for
  arm64); the x86 bzImage changes should be arriving next cycle,
  presumably via the -tip tree.

  Summary:

   - Add support for emitting a .sbat section into the EFI zboot image,
     so that downstreams can easily include revocation metadata in the
     signed EFI images

   - Align PE symbolic constant names with other projects

   - Bug fix for the efi_test module

   - Log the physical address and size of the EFI memory map when
     failing to map it

   - A kerneldoc fix for the EFI stub code"

* tag 'efi-next-for-v6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi:
  include: pe.h: Fix PE definitions
  efi/efi_test: Fix missing pending status update in getwakeuptime
  efi: zboot specific mechanism for embedding SBAT section
  efi/libstub: Describe missing 'out' parameter in efi_load_initrd
  efi: Improve logging around memmap init
2025-05-30 12:42:57 -07:00
Linus Torvalds
43db111107 ARM:
* Add large stage-2 mapping (THP) support for non-protected guests when
   pKVM is enabled, clawing back some performance.
 
 * Enable nested virtualisation support on systems that support it,
   though it is disabled by default.
 
 * Add UBSAN support to the standalone EL2 object used in nVHE/hVHE and
   protected modes.
 
 * Large rework of the way KVM tracks architecture features and links
   them with the effects of control bits. While this has no functional
   impact, it ensures correctness of emulation (the data is automatically
   extracted from the published JSON files), and helps dealing with the
   evolution of the architecture.
 
 * Significant changes to the way pKVM tracks ownership of pages,
   avoiding page table walks by storing the state in the hypervisor's
   vmemmap. This in turn enables the THP support described above.
 
 * New selftest checking the pKVM ownership transition rules
 
 * Fixes for FEAT_MTE_ASYNC being accidentally advertised to guests
   even if the host didn't have it.
 
 * Fixes for the address translation emulation, which happened to be
   rather buggy in some specific contexts.
 
 * Fixes for the PMU emulation in NV contexts, decoupling PMCR_EL0.N
   from the number of counters exposed to a guest and addressing a
   number of issues in the process.
 
 * Add a new selftest for the SVE host state being corrupted by a
   guest.
 
 * Keep HCR_EL2.xMO set at all times for systems running with the
   kernel at EL2, ensuring that the window for interrupts is slightly
   bigger, and avoiding a pretty bad erratum on the AmpereOne HW.
 
 * Add workaround for AmpereOne's erratum AC04_CPU_23, which suffers
   from a pretty bad case of TLB corruption unless accesses to HCR_EL2
   are heavily synchronised.
 
 * Add a per-VM, per-ITS debugfs entry to dump the state of the ITS
   tables in a human-friendly fashion.
 
 * and the usual random cleanups.
 
 LoongArch:
 
 * Don't flush tlb if the host supports hardware page table walks.
 
 * Add KVM selftests support.
 
 RISC-V:
 
 * Add vector registers to get-reg-list selftest
 
 * VCPU reset related improvements
 
 * Remove scounteren initialization from VCPU reset
 
 * Support VCPU reset from userspace using set_mpstate() ioctl
 
 x86:
 
 * Initial support for TDX in KVM.  This finally makes it possible to use the
   TDX module to run confidential guests on Intel processors.  This is quite a
   large series, including support for private page tables (managed by the
   TDX module and mirrored in KVM for efficiency), forwarding some TDVMCALLs
   to userspace, and handling several special VM exits from the TDX module.
 
   This has been in the works for literally years and it's not really possible
   to describe everything here, so I'll defer to the various merge commits
   up to and including commit 7bcf7246c4 ("Merge branch 'kvm-tdx-finish-initial'
   into HEAD").
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull kvm updates from Paolo Bonzini:
 "As far as x86 goes this pull request "only" includes TDX host support.

  Quotes are appropriate because (at 6k lines and 100+ commits) it is
  much bigger than the rest, which will come later this week and
  consists mostly of bugfixes and selftests. s390 changes will also come
  in the second batch.

  ARM:

   - Add large stage-2 mapping (THP) support for non-protected guests
     when pKVM is enabled, clawing back some performance.

   - Enable nested virtualisation support on systems that support it,
     though it is disabled by default.

   - Add UBSAN support to the standalone EL2 object used in nVHE/hVHE
     and protected modes.

   - Large rework of the way KVM tracks architecture features and links
     them with the effects of control bits. While this has no functional
     impact, it ensures correctness of emulation (the data is
     automatically extracted from the published JSON files), and helps
     dealing with the evolution of the architecture.

   - Significant changes to the way pKVM tracks ownership of pages,
     avoiding page table walks by storing the state in the hypervisor's
     vmemmap. This in turn enables the THP support described above.

   - New selftest checking the pKVM ownership transition rules

   - Fixes for FEAT_MTE_ASYNC being accidentally advertised to guests
     even if the host didn't have it.

   - Fixes for the address translation emulation, which happened to be
     rather buggy in some specific contexts.

   - Fixes for the PMU emulation in NV contexts, decoupling PMCR_EL0.N
     from the number of counters exposed to a guest and addressing a
     number of issues in the process.

   - Add a new selftest for the SVE host state being corrupted by a
     guest.

   - Keep HCR_EL2.xMO set at all times for systems running with the
     kernel at EL2, ensuring that the window for interrupts is slightly
     bigger, and avoiding a pretty bad erratum on the AmpereOne HW.

   - Add workaround for AmpereOne's erratum AC04_CPU_23, which suffers
     from a pretty bad case of TLB corruption unless accesses to HCR_EL2
     are heavily synchronised.

   - Add a per-VM, per-ITS debugfs entry to dump the state of the ITS
     tables in a human-friendly fashion.

   - and the usual random cleanups.

  LoongArch:

   - Don't flush tlb if the host supports hardware page table walks.

   - Add KVM selftests support.

  RISC-V:

   - Add vector registers to get-reg-list selftest

   - VCPU reset related improvements

   - Remove scounteren initialization from VCPU reset

   - Support VCPU reset from userspace using set_mpstate() ioctl

  x86:

   - Initial support for TDX in KVM.

     This finally makes it possible to use the TDX module to run
     confidential guests on Intel processors. This is quite a large
     series, including support for private page tables (managed by the
     TDX module and mirrored in KVM for efficiency), forwarding some
     TDVMCALLs to userspace, and handling several special VM exits from
     the TDX module.

     This has been in the works for literally years and it's not really
     possible to describe everything here, so I'll defer to the various
     merge commits up to and including commit 7bcf7246c4 ('Merge
     branch 'kvm-tdx-finish-initial' into HEAD')"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (248 commits)
  x86/tdx: mark tdh_vp_enter() as __flatten
  Documentation: virt/kvm: remove unreferenced footnote
  RISC-V: KVM: lock the correct mp_state during reset
  KVM: arm64: Fix documentation for vgic_its_iter_next()
  KVM: arm64: np-guest CMOs with PMD_SIZE fixmap
  KVM: arm64: Stage-2 huge mappings for np-guests
  KVM: arm64: Add a range to pkvm_mappings
  KVM: arm64: Convert pkvm_mappings to interval tree
  KVM: arm64: Add a range to __pkvm_host_test_clear_young_guest()
  KVM: arm64: Add a range to __pkvm_host_wrprotect_guest()
  KVM: arm64: Add a range to __pkvm_host_unshare_guest()
  KVM: arm64: Add a range to __pkvm_host_share_guest()
  KVM: arm64: Introduce for_each_hyp_page
  KVM: arm64: Handle huge mappings for np-guest CMOs
  KVM: arm64: nv: Release faulted-in VNCR page from mmu_lock critical section
  KVM: arm64: nv: Handle TLBI S1E2 for VNCR invalidation with mmu_lock held
  KVM: arm64: nv: Hold mmu_lock when invalidating VNCR SW-TLB before translating
  RISC-V: KVM: add KVM_CAP_RISCV_MP_STATE_RESET
  RISC-V: KVM: Remove scounteren initialization
  KVM: RISC-V: remove unnecessary SBI reset state
  ...
2025-05-29 08:10:01 -07:00
Linus Torvalds
47cf96fbe3 arm64 updates for 6.16
ACPI, EFI and PSCI:
  - Decouple Arm's "Software Delegated Exception Interface" (SDEI)
    support from the ACPI GHES code so that it can be used by platforms
    booted with device-tree.
 
  - Remove unnecessary per-CPU tracking of the FPSIMD state across EFI
    runtime calls.
 
  - Fix a node refcount imbalance in the PSCI device-tree code.
 
 CPU Features:
  - Ensure register sanitisation is applied to fields in ID_AA64MMFR4.
 
  - Expose AIDR_EL1 to userspace via sysfs, primarily so that KVM guests
    can reliably query the underlying CPU types from the VMM.
 
  - Re-enabling of SME support (CONFIG_ARM64_SME) as a result of fixes
    to our context-switching, signal handling and ptrace code.
 
 Entry code:
  - Hook up TIF_NEED_RESCHED_LAZY so that CONFIG_PREEMPT_LAZY can be
    selected.
 
 Memory management:
  - Prevent BSS exports from being used by the early PI code.
 
  - Propagate level and stride information to the low-level TLB
    invalidation routines when operating on hugetlb entries.
 
  - Use the page-table contiguous hint for vmap() mappings with
    VM_ALLOW_HUGE_VMAP where possible.
 
  - Optimise vmalloc()/vmap() page-table updates to use "lazy MMU mode"
    and hook this up on arm64 so that the trailing DSB (used to publish
    the updates to the hardware walker) can be deferred until the end of
    the mapping operation.
 
  - Extend mmap() randomisation for 52-bit virtual addresses (on par with
    48-bit addressing) and remove limited support for randomisation of
    the linear map.
 
 Perf and PMUs:
  - Add support for probing the CMN-S3 driver using ACPI.
 
  - Minor driver fixes to the CMN, Arm-NI and amlogic PMU drivers.
 
 Selftests:
  - Fix FPSIMD and SME tests to align with the freshly re-enabled SME
    support.
 
  - Fix default setting of the OUTPUT variable so that tests are
    installed in the right location.
 
 vDSO:
  - Replace raw counter access from inline assembly code with a call to
    the the __arch_counter_get_cntvct() helper function.
 
 Miscellaneous:
  - Add some missing header inclusions to the CCA headers.
 
  - Rework rendering of /proc/cpuinfo to follow the x86-approach and
    avoid repeated buffer expansion (the user-visible format remains
    identical).
 
  - Remove redundant selection of CONFIG_CRC32
 
  - Extend early error message when failing to map the device-tree blob.
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Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 updates from Will Deacon:
 "The headline feature is the re-enablement of support for Arm's
  Scalable Matrix Extension (SME) thanks to a bumper crop of fixes
  from Mark Rutland.

  If matrices aren't your thing, then Ryan's page-table optimisation
  work is much more interesting.

  Summary:

  ACPI, EFI and PSCI:

   - Decouple Arm's "Software Delegated Exception Interface" (SDEI)
     support from the ACPI GHES code so that it can be used by platforms
     booted with device-tree

   - Remove unnecessary per-CPU tracking of the FPSIMD state across EFI
     runtime calls

   - Fix a node refcount imbalance in the PSCI device-tree code

  CPU Features:

   - Ensure register sanitisation is applied to fields in ID_AA64MMFR4

   - Expose AIDR_EL1 to userspace via sysfs, primarily so that KVM
     guests can reliably query the underlying CPU types from the VMM

   - Re-enabling of SME support (CONFIG_ARM64_SME) as a result of fixes
     to our context-switching, signal handling and ptrace code

  Entry code:

   - Hook up TIF_NEED_RESCHED_LAZY so that CONFIG_PREEMPT_LAZY can be
     selected

  Memory management:

   - Prevent BSS exports from being used by the early PI code

   - Propagate level and stride information to the low-level TLB
     invalidation routines when operating on hugetlb entries

   - Use the page-table contiguous hint for vmap() mappings with
     VM_ALLOW_HUGE_VMAP where possible

   - Optimise vmalloc()/vmap() page-table updates to use "lazy MMU mode"
     and hook this up on arm64 so that the trailing DSB (used to publish
     the updates to the hardware walker) can be deferred until the end
     of the mapping operation

   - Extend mmap() randomisation for 52-bit virtual addresses (on par
     with 48-bit addressing) and remove limited support for
     randomisation of the linear map

  Perf and PMUs:

   - Add support for probing the CMN-S3 driver using ACPI

   - Minor driver fixes to the CMN, Arm-NI and amlogic PMU drivers

  Selftests:

   - Fix FPSIMD and SME tests to align with the freshly re-enabled SME
     support

   - Fix default setting of the OUTPUT variable so that tests are
     installed in the right location

  vDSO:

   - Replace raw counter access from inline assembly code with a call to
     the the __arch_counter_get_cntvct() helper function

  Miscellaneous:

   - Add some missing header inclusions to the CCA headers

   - Rework rendering of /proc/cpuinfo to follow the x86-approach and
     avoid repeated buffer expansion (the user-visible format remains
     identical)

   - Remove redundant selection of CONFIG_CRC32

   - Extend early error message when failing to map the device-tree
     blob"

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (83 commits)
  arm64: cputype: Add cputype definition for HIP12
  arm64: el2_setup.h: Make __init_el2_fgt labels consistent, again
  perf/arm-cmn: Add CMN S3 ACPI binding
  arm64/boot: Disallow BSS exports to startup code
  arm64/boot: Move global CPU override variables out of BSS
  arm64/boot: Move init_pgdir[] and init_idmap_pgdir[] into __pi_ namespace
  perf/arm-cmn: Initialise cmn->cpu earlier
  kselftest/arm64: Set default OUTPUT path when undefined
  arm64: Update comment regarding values in __boot_cpu_mode
  arm64: mm: Drop redundant check in pmd_trans_huge()
  arm64/mm: Re-organise setting up FEAT_S1PIE registers PIRE0_EL1 and PIR_EL1
  arm64/mm: Permit lazy_mmu_mode to be nested
  arm64/mm: Disable barrier batching in interrupt contexts
  arm64/cpuinfo: only show one cpu's info in c_show()
  arm64/mm: Batch barriers when updating kernel mappings
  mm/vmalloc: Enter lazy mmu mode while manipulating vmalloc ptes
  arm64/mm: Support huge pte-mapped pages in vmap
  mm/vmalloc: Gracefully unmap huge ptes
  mm/vmalloc: Warn on improper use of vunmap_range()
  arm64/mm: Hoist barriers out of set_ptes_anysz() loop
  ...
2025-05-28 14:55:35 -07:00
Will Deacon
53a087046a Merge branch 'for-next/sme-fixes' into for-next/core
* for-next/sme-fixes: (35 commits)
  arm64/fpsimd: Allow CONFIG_ARM64_SME to be selected
  arm64/fpsimd: ptrace: Gracefully handle errors
  arm64/fpsimd: ptrace: Mandate SVE payload for streaming-mode state
  arm64/fpsimd: ptrace: Do not present register data for inactive mode
  arm64/fpsimd: ptrace: Save task state before generating SVE header
  arm64/fpsimd: ptrace/prctl: Ensure VL changes leave task in a valid state
  arm64/fpsimd: ptrace/prctl: Ensure VL changes do not resurrect stale data
  arm64/fpsimd: Make clone() compatible with ZA lazy saving
  arm64/fpsimd: Clear PSTATE.SM during clone()
  arm64/fpsimd: Consistently preserve FPSIMD state during clone()
  arm64/fpsimd: Remove redundant task->mm check
  arm64/fpsimd: signal: Use SMSTOP behaviour in setup_return()
  arm64/fpsimd: Add task_smstop_sm()
  arm64/fpsimd: Factor out {sve,sme}_state_size() helpers
  arm64/fpsimd: Clarify sve_sync_*() functions
  arm64/fpsimd: ptrace: Consistently handle partial writes to NT_ARM_(S)SVE
  arm64/fpsimd: signal: Consistently read FPSIMD context
  arm64/fpsimd: signal: Mandate SVE payload for streaming-mode state
  arm64/fpsimd: signal: Clear PSTATE.SM when restoring FPSIMD frame only
  arm64/fpsimd: Do not discard modified SVE state
  ...
2025-05-27 12:26:43 +01:00
Will Deacon
c73497194a Merge branch 'for-next/mm' into for-next/core
* for-next/mm:
  arm64/boot: Disallow BSS exports to startup code
  arm64/boot: Move global CPU override variables out of BSS
  arm64/boot: Move init_pgdir[] and init_idmap_pgdir[] into __pi_ namespace
  arm64: mm: Drop redundant check in pmd_trans_huge()
  arm64/mm: Permit lazy_mmu_mode to be nested
  arm64/mm: Disable barrier batching in interrupt contexts
  arm64/mm: Batch barriers when updating kernel mappings
  mm/vmalloc: Enter lazy mmu mode while manipulating vmalloc ptes
  arm64/mm: Support huge pte-mapped pages in vmap
  mm/vmalloc: Gracefully unmap huge ptes
  mm/vmalloc: Warn on improper use of vunmap_range()
  arm64/mm: Hoist barriers out of set_ptes_anysz() loop
  arm64: hugetlb: Use __set_ptes_anysz() and __ptep_get_and_clear_anysz()
  arm64/mm: Refactor __set_ptes() and __ptep_get_and_clear()
  mm/page_table_check: Batch-check pmds/puds just like ptes
  arm64: hugetlb: Refine tlb maintenance scope
  arm64: hugetlb: Cleanup huge_pte size discovery mechanisms
  arm64: pageattr: Explicitly bail out when changing permissions for vmalloc_huge mappings
  arm64: Support ARM64_VA_BITS=52 when setting ARCH_MMAP_RND_BITS_MAX
  arm64/mm: Remove randomization of the linear map
2025-05-27 12:26:06 +01:00
Will Deacon
9d27622f7d Merge branch 'for-next/misc' into for-next/core
* for-next/misc:
  arm64/cpuinfo: only show one cpu's info in c_show()
  arm64: Extend pr_crit message on invalid FDT
  arm64: Kconfig: remove unnecessary selection of CRC32
  arm64: Add missing includes for mem_encrypt
2025-05-27 12:25:58 +01:00
Will Deacon
dc64de4033 Merge branch 'for-next/fixes' into for-next/core
Merge in for-next/fixes, as subsequent improvements to our early PI
code that disallow BSS exports depend on the 'arm64_use_ng_mappings'
fix here.

* for-next/fixes:
  arm64: cpufeature: Move arm64_use_ng_mappings to the .data section to prevent wrong idmap generation
  arm64: errata: Add missing sentinels to Spectre-BHB MIDR arrays
2025-05-27 12:24:18 +01:00
Will Deacon
48055fb882 Merge branch 'for-next/entry' into for-next/core
* for-next/entry:
  arm64: el2_setup.h: Make __init_el2_fgt labels consistent, again
  arm64: Update comment regarding values in __boot_cpu_mode
  arm64/mm: Re-organise setting up FEAT_S1PIE registers PIRE0_EL1 and PIR_EL1
  arm64: enable PREEMPT_LAZY
2025-05-27 12:24:12 +01:00
Will Deacon
b5b6910f83 Merge branch 'for-next/efi' into for-next/core
* for-next/efi:
  arm64/fpsimd: Avoid unnecessary per-CPU buffers for EFI runtime calls
2025-05-27 12:24:02 +01:00
Paolo Bonzini
4d526b02df KVM/arm64 updates for 6.16
* New features:
 
   - Add large stage-2 mapping support for non-protected pKVM guests,
     clawing back some performance.
 
   - Add UBSAN support to the standalone EL2 object used in nVHE/hVHE and
     protected modes.
 
   - Enable nested virtualisation support on systems that support it
     (yes, it has been a long time coming), though it is disabled by
     default.
 
 * Improvements, fixes and cleanups:
 
   - Large rework of the way KVM tracks architecture features and links
     them with the effects of control bits. This ensures correctness of
     emulation (the data is automatically extracted from the published
     JSON files), and helps dealing with the evolution of the
     architecture.
 
   - Significant changes to the way pKVM tracks ownership of pages,
     avoiding page table walks by storing the state in the hypervisor's
     vmemmap. This in turn enables the THP support described above.
 
   - New selftest checking the pKVM ownership transition rules
 
   - Fixes for FEAT_MTE_ASYNC being accidentally advertised to guests
     even if the host didn't have it.
 
   - Fixes for the address translation emulation, which happened to be
     rather buggy in some specific contexts.
 
   - Fixes for the PMU emulation in NV contexts, decoupling PMCR_EL0.N
     from the number of counters exposed to a guest and addressing a
     number of issues in the process.
 
   - Add a new selftest for the SVE host state being corrupted by a
     guest.
 
   - Keep HCR_EL2.xMO set at all times for systems running with the
     kernel at EL2, ensuring that the window for interrupts is slightly
     bigger, and avoiding a pretty bad erratum on the AmpereOne HW.
 
   - Add workaround for AmpereOne's erratum AC04_CPU_23, which suffers
     from a pretty bad case of TLB corruption unless accesses to HCR_EL2
     are heavily synchronised.
 
   - Add a per-VM, per-ITS debugfs entry to dump the state of the ITS
     tables in a human-friendly fashion.
 
   - and the usual random cleanups.
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Merge tag 'kvmarm-6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm64 updates for 6.16

* New features:

  - Add large stage-2 mapping support for non-protected pKVM guests,
    clawing back some performance.

  - Add UBSAN support to the standalone EL2 object used in nVHE/hVHE and
    protected modes.

  - Enable nested virtualisation support on systems that support it
    (yes, it has been a long time coming), though it is disabled by
    default.

* Improvements, fixes and cleanups:

  - Large rework of the way KVM tracks architecture features and links
    them with the effects of control bits. This ensures correctness of
    emulation (the data is automatically extracted from the published
    JSON files), and helps dealing with the evolution of the
    architecture.

  - Significant changes to the way pKVM tracks ownership of pages,
    avoiding page table walks by storing the state in the hypervisor's
    vmemmap. This in turn enables the THP support described above.

  - New selftest checking the pKVM ownership transition rules

  - Fixes for FEAT_MTE_ASYNC being accidentally advertised to guests
    even if the host didn't have it.

  - Fixes for the address translation emulation, which happened to be
    rather buggy in some specific contexts.

  - Fixes for the PMU emulation in NV contexts, decoupling PMCR_EL0.N
    from the number of counters exposed to a guest and addressing a
    number of issues in the process.

  - Add a new selftest for the SVE host state being corrupted by a
    guest.

  - Keep HCR_EL2.xMO set at all times for systems running with the
    kernel at EL2, ensuring that the window for interrupts is slightly
    bigger, and avoiding a pretty bad erratum on the AmpereOne HW.

  - Add workaround for AmpereOne's erratum AC04_CPU_23, which suffers
    from a pretty bad case of TLB corruption unless accesses to HCR_EL2
    are heavily synchronised.

  - Add a per-VM, per-ITS debugfs entry to dump the state of the ITS
    tables in a human-friendly fashion.

  - and the usual random cleanups.
2025-05-26 16:19:46 -04:00
Marc Zyngier
1b85d923ba Merge branch kvm-arm64/misc-6.16 into kvmarm-master/next
* kvm-arm64/misc-6.16:
  : .
  : Misc changes and improvements for 6.16:
  :
  : - Add a new selftest for the SVE host state being corrupted by a guest
  :
  : - Keep HCR_EL2.xMO set at all times for systems running with the kernel at EL2,
  :   ensuring that the window for interrupts is slightly bigger, and avoiding
  :   a pretty bad erratum on the AmpereOne HW
  :
  : - Replace a couple of open-coded on/off strings with str_on_off()
  :
  : - Get rid of the pKVM memblock sorting, which now appears to be superflous
  :
  : - Drop superflous clearing of ICH_LR_EOI in the LR when nesting
  :
  : - Add workaround for AmpereOne's erratum AC04_CPU_23, which suffers from
  :   a pretty bad case of TLB corruption unless accesses to HCR_EL2 are
  :   heavily synchronised
  :
  : - Add a per-VM, per-ITS debugfs entry to dump the state of the ITS tables
  :   in a human-friendly fashion
  : .
  KVM: arm64: Fix documentation for vgic_its_iter_next()
  KVM: arm64: vgic-its: Add debugfs interface to expose ITS tables
  arm64: errata: Work around AmpereOne's erratum AC04_CPU_23
  KVM: arm64: nv: Remove clearing of ICH_LR<n>.EOI if ICH_LR<n>.HW == 1
  KVM: arm64: Drop sort_memblock_regions()
  KVM: arm64: selftests: Add test for SVE host corruption
  KVM: arm64: Force HCR_EL2.xMO to 1 at all times in VHE mode
  KVM: arm64: Replace ternary flags with str_on_off() helper

Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-05-23 10:59:43 +01:00
Marc Zyngier
fef3acf5ae Merge branch kvm-arm64/fgt-masks into kvmarm-master/next
* kvm-arm64/fgt-masks: (43 commits)
  : .
  : Large rework of the way KVM deals with trap bits in conjunction with
  : the CPU feature registers. It now draws a direct link between which
  : the feature set, the system registers that need to UNDEF to match
  : the configuration and bits that need to behave as RES0 or RES1 in
  : the trap registers that are visible to the guest.
  :
  : Best of all, these definitions are mostly automatically generated
  : from the JSON description published by ARM under a permissive
  : license.
  : .
  KVM: arm64: Handle TSB CSYNC traps
  KVM: arm64: Add FGT descriptors for FEAT_FGT2
  KVM: arm64: Allow sysreg ranges for FGT descriptors
  KVM: arm64: Add context-switch for FEAT_FGT2 registers
  KVM: arm64: Add trap routing for FEAT_FGT2 registers
  KVM: arm64: Add sanitisation for FEAT_FGT2 registers
  KVM: arm64: Add FEAT_FGT2 registers to the VNCR page
  KVM: arm64: Use HCR_EL2 feature map to drive fixed-value bits
  KVM: arm64: Use HCRX_EL2 feature map to drive fixed-value bits
  KVM: arm64: Allow kvm_has_feat() to take variable arguments
  KVM: arm64: Use FGT feature maps to drive RES0 bits
  KVM: arm64: Validate FGT register descriptions against RES0 masks
  KVM: arm64: Switch to table-driven FGU configuration
  KVM: arm64: Handle PSB CSYNC traps
  KVM: arm64: Use KVM-specific HCRX_EL2 RES0 mask
  KVM: arm64: Remove hand-crafted masks for FGT registers
  KVM: arm64: Use computed FGT masks to setup FGT registers
  KVM: arm64: Propagate FGT masks to the nVHE hypervisor
  KVM: arm64: Unconditionally configure fine-grain traps
  KVM: arm64: Use computed masks as sanitisers for FGT registers
  ...

Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-05-23 10:58:15 +01:00
Marc Zyngier
6eb0ed9629 Merge branch kvm-arm64/mte-frac into kvmarm-master/next
* kvm-arm64/mte-frac:
  : .
  : Prevent FEAT_MTE_ASYNC from being accidently exposed to a guest,
  : courtesy of Ben Horgan. From the cover letter:
  :
  : "The ID_AA64PFR1_EL1.MTE_frac field is currently hidden from KVM.
  : However, when ID_AA64PFR1_EL1.MTE==2, ID_AA64PFR1_EL1.MTE_frac==0
  : indicates that MTE_ASYNC is supported. On a host with
  : ID_AA64PFR1_EL1.MTE==2 but without MTE_ASYNC support a guest with the
  : MTE capability enabled will incorrectly see MTE_ASYNC advertised as
  : supported. This series fixes that."
  : .
  KVM: selftests: Confirm exposing MTE_frac does not break migration
  KVM: arm64: Make MTE_frac masking conditional on MTE capability
  arm64/sysreg: Expose MTE_frac so that it is visible to KVM

Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-05-23 10:57:44 +01:00
Marc Zyngier
cb86616c39 Merge branch kvm-arm64/ubsan-el2 into kvmarm-master/next
* kvm-arm64/ubsan-el2:
  : .
  : Add UBSAN support to the EL2 portion of KVM, reusing most of the
  : existing logic provided by CONFIG_IBSAN_TRAP.
  :
  : Patches courtesy of Mostafa Saleh.
  : .
  KVM: arm64: Handle UBSAN faults
  KVM: arm64: Introduce CONFIG_UBSAN_KVM_EL2
  ubsan: Remove regs from report_ubsan_failure()
  arm64: Introduce esr_is_ubsan_brk()

Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-05-23 10:57:32 +01:00
Pali Rohár
46550e2b87 include: pe.h: Fix PE definitions
* Rename constants to their standard PE names:
  - MZ_MAGIC -> IMAGE_DOS_SIGNATURE
  - PE_MAGIC -> IMAGE_NT_SIGNATURE
  - PE_OPT_MAGIC_PE32_ROM -> IMAGE_ROM_OPTIONAL_HDR_MAGIC
  - PE_OPT_MAGIC_PE32 -> IMAGE_NT_OPTIONAL_HDR32_MAGIC
  - PE_OPT_MAGIC_PE32PLUS -> IMAGE_NT_OPTIONAL_HDR64_MAGIC
  - IMAGE_DLL_CHARACTERISTICS_NX_COMPAT -> IMAGE_DLLCHARACTERISTICS_NX_COMPAT

* Import constants and their description from readpe and file projects
  which contains current up-to-date information:
  - IMAGE_FILE_MACHINE_*
  - IMAGE_FILE_*
  - IMAGE_SUBSYSTEM_*
  - IMAGE_DLLCHARACTERISTICS_*
  - IMAGE_DLLCHARACTERISTICS_EX_*
  - IMAGE_DEBUG_TYPE_*

* Add missing IMAGE_SCN_* constants and update their incorrect description

* Fix incorrect value of IMAGE_SCN_MEM_PURGEABLE constant

* Add description for win32_version and loader_flags PE fields

Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2025-05-21 16:46:37 +02:00
Marc Zyngier
d5702dd224 Merge branch kvm-arm64/pkvm-selftest-6.16 into kvm-arm64/pkvm-np-thp-6.16
* kvm-arm64/pkvm-selftest-6.16:
  : .
  : pKVM selftests covering the memory ownership transitions by
  : Quentin Perret. From the initial cover letter:
  :
  : "We have recently found a bug [1] in the pKVM memory ownership
  : transitions by code inspection, but it could have been caught with a
  : test.
  :
  : Introduce a boot-time selftest exercising all the known pKVM memory
  : transitions and importantly checks the rejection of illegal transitions.
  :
  : The new test is hidden behind a new Kconfig option separate from
  : CONFIG_EL2_NVHE_DEBUG on purpose as that has side effects on the
  : transition checks ([1] doesn't reproduce with EL2 debug enabled).
  :
  : [1] https://lore.kernel.org/kvmarm/20241128154406.602875-1-qperret@google.com/"
  : .
  KVM: arm64: Extend pKVM selftest for np-guests
  KVM: arm64: Selftest for pKVM transitions
  KVM: arm64: Don't WARN from __pkvm_host_share_guest()
  KVM: arm64: Add .hyp.data section

Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-05-21 14:33:43 +01:00
D Scott Phillips
fed55f49fa arm64: errata: Work around AmpereOne's erratum AC04_CPU_23
On AmpereOne AC04, updates to HCR_EL2 can rarely corrupt simultaneous
translations for data addresses initiated by load/store instructions.
Only instruction initiated translations are vulnerable, not translations
from prefetches for example. A DSB before the store to HCR_EL2 is
sufficient to prevent older instructions from hitting the window for
corruption, and an ISB after is sufficient to prevent younger
instructions from hitting the window for corruption.

Signed-off-by: D Scott Phillips <scott@os.amperecomputing.com>
Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20250513184514.2678288-1-scott@os.amperecomputing.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-05-19 12:46:26 +01:00
Ard Biesheuvel
9053052107 arm64/boot: Disallow BSS exports to startup code
BSS might be uninitialized when entering the startup code, so forbid the
use by the startup code of any variables that live after __bss_start in
the linker map.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Tested-by: Yeoreum Yun <yeoreum.yun@arm.com>
Reviewed-by: Yeoreum Yun <yeoreum.yun@arm.com>
Link: https://lore.kernel.org/r/20250508114328.2460610-8-ardb+git@google.com
[will: Drop export of 'memstart_offset_seed', as this has been removed]
Signed-off-by: Will Deacon <will@kernel.org>
2025-05-16 16:08:13 +01:00
Ard Biesheuvel
4afff6cc9a arm64/boot: Move global CPU override variables out of BSS
Accessing BSS will no longer be permitted from the startup code in
arch/arm64/kernel/pi, as some of it executes before BSS is cleared.
Clearing BSS earlier would involve managing cache coherency explicitly
in software, which is a hassle we prefer to avoid.

So move some variables that are assigned by the startup code out of BSS
and into .data.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Tested-by: Yeoreum Yun <yeoreum.yun@arm.com>
Reviewed-by: Yeoreum Yun <yeoreum.yun@arm.com>
Link: https://lore.kernel.org/r/20250508114328.2460610-7-ardb+git@google.com
Signed-off-by: Will Deacon <will@kernel.org>
2025-05-16 16:05:21 +01:00
Ard Biesheuvel
93d0d6f8a6 arm64/boot: Move init_pgdir[] and init_idmap_pgdir[] into __pi_ namespace
init_pgdir[] is only referenced from the startup code, but lives after
BSS in the linker map. Before tightening the rules about accessing BSS
from startup code, move init_pgdir[] into the __pi_ namespace, so it
does not need to be exported explicitly.

For symmetry, do the same with init_idmap_pgdir[], although it lives
before BSS.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Tested-by: Yeoreum Yun <yeoreum.yun@arm.com>
Reviewed-by: Yeoreum Yun <yeoreum.yun@arm.com>
Link: https://lore.kernel.org/r/20250508114328.2460610-6-ardb+git@google.com
Signed-off-by: Will Deacon <will@kernel.org>
2025-05-16 16:05:21 +01:00
Anshuman Khandual
29e31da4ed arm64/mm: Re-organise setting up FEAT_S1PIE registers PIRE0_EL1 and PIR_EL1
mov_q cannot really move PIE_E[0|1] macros into a general purpose register
as expected if those macro constants contain some 128 bit layout elements,
that are required for D128 page tables. The primary issue is that for D128,
PIE_E[0|1] are defined in terms of 128-bit types with shifting and masking,
which the assembler can't accommodate.

Instead pre-calculate these PIRE0_EL1/PIR_EL1 constants into asm-offsets.h
based PIE_E0_ASM/PIE_E1_ASM which can then be used in arch/arm64/mm/proc.S.

While here also drop PTE_MAYBE_NG/PTE_MAYBE_SHARED assembly overrides which
are not required any longer, as the compiler toolchains are smart enough to
compute both the PIE_[E0|E1]_ASM constants in all scenarios.

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Ryan Roberts <ryan.roberts@arm.com>
Link: https://lore.kernel.org/r/20250429050511.1663235-1-anshuman.khandual@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
2025-05-16 15:06:36 +01:00
Ben Horgan
5799a2983f arm64/sysreg: Expose MTE_frac so that it is visible to KVM
KVM exposes the sanitised ID registers to guests. Currently these ignore
the ID_AA64PFR1_EL1.MTE_frac field, meaning guests always see a value of
zero.

This is a problem for platforms without the MTE_ASYNC feature where
ID_AA64PFR1_EL1.MTE==0x2 and ID_AA64PFR1_EL1.MTE_frac==0xf. KVM forces
MTE_frac to zero, meaning the guest believes MTE_ASYNC is supported, when
no async fault will ever occur.

Before KVM can fix this, the architecture needs to sanitise the ID
register field for MTE_frac.

Linux itself does not use MTE_frac field and just assumes MTE async faults
can be generated if MTE is supported.

Signed-off-by: Ben Horgan <ben.horgan@arm.com>
Link: https://lore.kernel.org/r/20250512114112.359087-2-ben.horgan@arm.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-05-16 13:01:18 +01:00
Anshuman Khandual
dbb9c166a0 arm64/mm: define ptdesc_t
Define ptdesc_t type which describes the basic page table descriptor
layout on arm64 platform.  Subsequently all level specific pxxval_t
descriptors are derived from ptdesc_t thus establishing a common original
format, which can also be appropriate for page table entries, masks and
protection values etc which are used at all page table levels.

Link: https://lkml.kernel.org/r/20250407053113.746295-4-anshuman.khandual@arm.com
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Suggested-by: Ryan Roberts <ryan.roberts@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-05-11 17:48:19 -07:00
Linus Torvalds
627277ba7c * Add BHB mitigations to cBPF programs.
* Add new CPUs local mitigation 'k' values.
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Merge tag 'arm64_cbpf_mitigation_2025_05_08' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 cBPF BHB mitigation from James Morse:
 "This adds the BHB mitigation into the code JITted for cBPF programs as
  these can be loaded by unprivileged users via features like seccomp.

  The existing mechanisms to disable the BHB mitigation will also
  prevent the mitigation being JITted. In addition, cBPF programs loaded
  by processes with the SYS_ADMIN capability are not mitigated as these
  could equally load an eBPF program that does the same thing.

  For good measure, the list of 'k' values for CPU's local mitigations
  is updated from the version on arm's website"

* tag 'arm64_cbpf_mitigation_2025_05_08' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: proton-pack: Add new CPUs 'k' values for branch mitigation
  arm64: bpf: Only mitigate cBPF programs loaded by unprivileged users
  arm64: bpf: Add BHB mitigation to the epilogue for cBPF programs
  arm64: proton-pack: Expose whether the branchy loop k value
  arm64: proton-pack: Expose whether the platform is mitigated by firmware
  arm64: insn: Add support for encoding DSB
2025-05-11 17:45:00 -07:00
Linus Torvalds
50358c251e Move the arm64_use_ng_mappings variable from the .bss to the .data
section as it is accessed very early during boot with the MMU off and
 before the .bss has been initialised. This can lead to incorrect idmap
 page table.
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Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 fix from Catalin Marinas:
 "Move the arm64_use_ng_mappings variable from the .bss to the .data
  section as it is accessed very early during boot with the MMU off and
  before the .bss has been initialised.

  This could lead to incorrect idmap page table"

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: cpufeature: Move arm64_use_ng_mappings to the .data section to prevent wrong idmap generation
2025-05-09 11:30:26 -07:00
Ye Bin
7bb797757b arm64/cpuinfo: only show one cpu's info in c_show()
Currently, when ARM64 displays CPU information, every call to c_show()
assembles all CPU information. However, as the number of CPUs increases,
this can lead to insufficient buffer space due to excessive assembly in
a single call, causing repeated expansion and multiple calls to c_show().

To prevent this invalid c_show() call, only one CPU's information is
assembled each time c_show() is called.

Signed-off-by: Ye Bin <yebin10@huawei.com>
Link: https://lore.kernel.org/r/20250421062947.4072855-1-yebin@huaweicloud.com
Signed-off-by: Will Deacon <will@kernel.org>
2025-05-09 15:30:20 +01:00
Ryan Roberts
5fdd05efa1 arm64/mm: Batch barriers when updating kernel mappings
Because the kernel can't tolerate page faults for kernel mappings, when
setting a valid, kernel space pte (or pmd/pud/p4d/pgd), it emits a
dsb(ishst) to ensure that the store to the pgtable is observed by the
table walker immediately. Additionally it emits an isb() to ensure that
any already speculatively determined invalid mapping fault gets
canceled.

We can improve the performance of vmalloc operations by batching these
barriers until the end of a set of entry updates.
arch_enter_lazy_mmu_mode() and arch_leave_lazy_mmu_mode() provide the
required hooks.

vmalloc improves by up to 30% as a result.

Two new TIF_ flags are created; TIF_LAZY_MMU tells us if the task is in
the lazy mode and can therefore defer any barriers until exit from the
lazy mode. TIF_LAZY_MMU_PENDING is used to remember if any pte operation
was performed while in the lazy mode that required barriers. Then when
leaving lazy mode, if that flag is set, we emit the barriers.

Since arch_enter_lazy_mmu_mode() and arch_leave_lazy_mmu_mode() are used
for both user and kernel mappings, we need the second flag to avoid
emitting barriers unnecessarily if only user mappings were updated.

Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Tested-by: Luiz Capitulino <luizcap@redhat.com>
Link: https://lore.kernel.org/r/20250422081822.1836315-12-ryan.roberts@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
2025-05-09 13:43:08 +01:00
James Morse
efe676a1a7 arm64: proton-pack: Add new CPUs 'k' values for branch mitigation
Update the list of 'k' values for the branch mitigation from arm's
website.

Add the values for Cortex-X1C. The MIDR_EL1 value can be found here:
https://developer.arm.com/documentation/101968/0002/Register-descriptions/AArch>

Link: https://developer.arm.com/documentation/110280/2-0/?lang=en
Signed-off-by: James Morse <james.morse@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
2025-05-08 15:29:28 +01:00
Mark Rutland
9f8bf718f2 arm64/fpsimd: ptrace: Gracefully handle errors
Within sve_set_common() we do not handle error conditions correctly:

* When writing to NT_ARM_SSVE, if sme_alloc() fails, the task will be
  left with task->thread.sme_state==NULL, but TIF_SME will be set and
  task->thread.fp_type==FP_STATE_SVE. This will result in a subsequent
  null pointer dereference when the task's state is loaded or otherwise
  manipulated.

* When writing to NT_ARM_SSVE, if sve_alloc() fails, the task will be
  left with task->thread.sve_state==NULL, but TIF_SME will be set,
  PSTATE.SM will be set, and task->thread.fp_type==FP_STATE_FPSIMD.
  This is not a legitimate state, and can result in various problems,
  including a subsequent null pointer dereference and/or the task
  inheriting stale streaming mode register state the next time its state
  is loaded into hardware.

* When writing to NT_ARM_SSVE, if the VL is changed but the resulting VL
  differs from that in the header, the task will be left with TIF_SME
  set, PSTATE.SM set, but task->thread.fp_type==FP_STATE_FPSIMD. This is
  not a legitimate state, and can result in various problems as
  described above.

Avoid these problems by allocating memory earlier, and by changing the
task's saved fp_type to FP_STATE_SVE before skipping register writes due
to a change of VL.

To make early returns simpler, I've moved the call to
fpsimd_flush_task_state() earlier. As the tracee's state has already
been saved, and the tracee is known to be blocked for the duration of
sve_set_common(), it doesn't matter whether this is called at the start
or the end.

For consistency I've moved the setting of TIF_SVE earlier. This will be
cleared when loading FPSIMD-only state, and so moving this has no
resulting functional change.

Note that we only allocate the memory for SVE state when SVE register
contents are provided, avoiding unnecessary memory allocations for tasks
which only use FPSIMD.

Fixes: e12310a0d3 ("arm64/sme: Implement ptrace support for streaming mode SVE registers")
Fixes: baa8515281 ("arm64/fpsimd: Track the saved FPSIMD state type separately to TIF_SVE")
Fixes: 5d0a8d2fba ("arm64/ptrace: Ensure that SME is set up for target when writing SSVE state")
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Spickett <david.spickett@arm.com>
Cc: Luis Machado <luis.machado@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20250508132644.1395904-20-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
2025-05-08 15:29:11 +01:00
Mark Rutland
f916dd32a9 arm64/fpsimd: ptrace: Mandate SVE payload for streaming-mode state
When a task has PSTATE.SM==1, reads of NT_ARM_SSVE are required to
always present a header with SVE_PT_REGS_SVE, and register data in SVE
format. Reads of NT_ARM_SSVE must never present register data in FPSIMD
format. Within the kernel, we always expect streaming SVE data to be
stored in SVE format.

Currently a user can write to NT_ARM_SSVE with a header presenting
SVE_PT_REGS_FPSIMD rather than SVE_PT_REGS_SVE, placing the task's
FPSIMD/SVE data into an invalid state.

To fix this we can either:

(a) Forbid such writes.
(b) Accept such writes, and immediately convert data into SVE format.

Take the simple option and forbid such writes.

Fixes: e12310a0d3 ("arm64/sme: Implement ptrace support for streaming mode SVE registers")
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Spickett <david.spickett@arm.com>
Cc: Luis Machado <luis.machado@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Will Deacon <will@kernel.org>
Reviewed-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20250508132644.1395904-19-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
2025-05-08 15:29:11 +01:00
Mark Rutland
b93e685ecf arm64/fpsimd: ptrace: Do not present register data for inactive mode
The SME ptrace ABI is written around the incorrect assumption that
SVE_PT_REGS_FPSIMD and SVE_PT_REGS_SVE are independent bit flags, where
it is possible for both to be clear. In reality they are different
values for bit 0 of the header flags, where SVE_PT_REGS_FPSIMD is 0 and
SVE_PT_REGS_SVE is 1. In cases where code was written expecting that
neither bit flag would be set, the value is equivalent to
SVE_PT_REGS_FPSIMD.

One consequence of this is that reads of the NT_ARM_SVE or NT_ARM_SSVE
will erroneously present data from the other mode:

* When PSTATE.SM==1, reads of NT_ARM_SVE will present a header with
  SVE_PT_REGS_FPSIMD, and FPSIMD-formatted data from streaming mode.

* When PSTATE.SM==0, reads of NT_ARM_SSVE will present a header with
  SVE_PT_REGS_FPSIMD, and FPSIMD-formatted data from non-streaming mode.

The original intent was that no register data would be provided in these
cases, as described in commit:

  e12310a0d3 ("arm64/sme: Implement ptrace support for streaming mode SVE registers")

Luckily, debuggers do not consume the bogus register data. Both GDB and
LLDB read the NT_ARM_SSVE regset before the NT_ARM_SVE regset, and
assume that when the NT_ARM_SSVE header presents SVE_PT_REGS_FPSIMD, it
is necessary to read register contents from the NT_ARM_SVE regset,
regardless of whether the NT_ARM_SSVE regset provided bogus register
data.

Fix the code to stop presenting register data from the inactive mode.
At the same time, make the manipulation of the flag clearer, and remove
the bogus comment from sve_set_common(). I've given this a quick spin
with GDB and LLDB, and both seem happy.

Fixes: e12310a0d3 ("arm64/sme: Implement ptrace support for streaming mode SVE registers")
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Spickett <david.spickett@arm.com>
Cc: Luis Machado <luis.machado@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20250508132644.1395904-18-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
2025-05-08 15:29:11 +01:00
Mark Rutland
054d627c55 arm64/fpsimd: ptrace: Save task state before generating SVE header
As sve_init_header_from_task() consumes the saved value of PSTATE.SM and
the saved fp_type, both must be saved before the header is generated.

When generating a coredump for the current task, sve_get_common() calls
sve_init_header_from_task() before saving the task's state. Consequently
the header may be bogus, and the contents of the regset may be
misleading.

Fix this by saving the task's state before generting the header.

Fixes: e12310a0d3 ("arm64/sme: Implement ptrace support for streaming mode SVE registers")
Fixes: b017a0cea6 ("arm64/ptrace: Use saved floating point state type to determine SVE layout")
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Spickett <david.spickett@arm.com>
Cc: Luis Machado <luis.machado@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20250508132644.1395904-17-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
2025-05-08 15:29:11 +01:00
Mark Rutland
b87c8c4aca arm64/fpsimd: ptrace/prctl: Ensure VL changes leave task in a valid state
Currently, vec_set_vector_length() can manipulate a task into an invalid
state as a result of a prctl/ptrace syscall which changes the SVE/SME
vector length, resulting in several problems:

(1) When changing the SVE vector length, if the task initially has
    PSTATE.ZA==1, and sve_alloc() fails to allocate memory, the task
    will be left with PSTATE.ZA==1 and sve_state==NULL. This is not a
    legitimate state, and could result in a subsequent null pointer
    dereference.

(2) When changing the SVE vector length, if the task initially has
    PSTATE.SM==1, the task will be left with PSTATE.SM==1 and
    fp_type==FP_STATE_FPSIMD. Streaming mode state always needs to be
    saved in SVE format, so this is not a legitimate state.

    Attempting to restore this state may cause a task to erroneously
    inherit stale streaming mode predicate registers and FFR contents,
    behaving non-deterministically and potentially leaving information
    from another task.

    While in this state, reads of the NT_ARM_SSVE regset will indicate
    that the registers are not stored in SVE format. For the NT_ARM_SSVE
    regset specifically, debuggers interpret this as meaning that
    PSTATE.SM==0.

(3) When changing the SME vector length, if the task initially has
    PSTATE.SM==1, the lower 128 bits of task's streaming mode vector
    state will be migrated to non-streaming mode, rather than these bits
    being zeroed as is usually the case for changes to PSTATE.SM.

To fix the first issue, we can eagerly allocate the new sve_state and
sme_state before modifying the task. This makes it possible to handle
memory allocation failure without modifying the task state at all, and
removes the need to clear TIF_SVE and TIF_SME.

To fix the second issue, we either need to clear PSTATE.SM or not change
the saved fp_type. Given we're going to eagerly allocate sve_state and
sme_state, the simplest option is to preserve PSTATE.SM and the saves
fp_type, and consistently truncate the SVE state. This ensures that the
task always stays in a valid state, and by virtue of not exiting
streaming mode, this also sidesteps the third issue.

I believe these changes should not be problematic for realistic usage:

* When the SVE/SME vector length is changed via prctl(), syscall entry
  will have cleared PSTATE.SM. Unless the task's state has been
  manipulated via ptrace after entry, the task will have PSTATE.SM==0.

* When the SVE/SME vector length is changed via a write to the
  NT_ARM_SVE or NT_ARM_SSVE regsets, PSTATE.SM will be forced
  immediately after the length change, and new vector state will be
  copied from userspace.

* When the SME vector length is changed via a write to the NT_ARM_ZA
  regset, the (S)SVE state is clobbered today, so anyone who cares about
  the specific state would need to install this after writing to the
  NT_ARM_ZA regset.

As we need to free the old SVE state while TIF_SVE may still be set, we
cannot use sve_free(), and using kfree() directly makes it clear that
the free pairs with the subsequent assignment. As this leaves sve_free()
unused, I've removed the existing sve_free() and renamed __sve_free() to
mirror sme_free().

Fixes: 8bd7f91c03 ("arm64/sme: Implement traps and syscall handling for SME")
Fixes: baa8515281 ("arm64/fpsimd: Track the saved FPSIMD state type separately to TIF_SVE")
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Spickett <david.spickett@arm.com>
Cc: Luis Machado <luis.machado@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20250508132644.1395904-16-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
2025-05-08 15:29:11 +01:00
Mark Rutland
49ce484187 arm64/fpsimd: ptrace/prctl: Ensure VL changes do not resurrect stale data
The SVE/SME vector lengths can be changed via prctl/ptrace syscalls.
Changes to the SVE/SME vector lengths are documented as preserving the
lower 128 bits of the Z registers (i.e. the bits shared with the FPSIMD
V registers). To ensure this, vec_set_vector_length() explicitly copies
register values from a task's saved SVE state to its saved FPSIMD state
when dropping the task to FPSIMD-only.

The logic for this was not updated when when FPSIMD/SVE state tracking
was changed across commits:

  baa8515281 ("arm64/fpsimd: Track the saved FPSIMD state type separately to TIF_SVE")
  a0136be443 (arm64/fpsimd: Load FP state based on recorded data type")
  bbc6172eef ("arm64/fpsimd: SME no longer requires SVE register state")
  8c845e2731 ("arm64/sve: Leave SVE enabled on syscall if we don't context switch")

Since the last commit above, a task's FPSIMD/SVE state may be stored in
FPSIMD format while TIF_SVE is set, and the stored SVE state is stale.
When vec_set_vector_length() encounters this case, it will erroneously
clobber the live FPSIMD state with stale SVE state by using
sve_to_fpsimd().

Fix this by using fpsimd_sync_from_effective_state() instead.

Related issues with streaming mode state will be addressed in subsequent
patches.

Fixes: 8c845e2731 ("arm64/sve: Leave SVE enabled on syscall if we don't context switch")
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Spickett <david.spickett@arm.com>
Cc: Luis Machado <luis.machado@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20250508132644.1395904-15-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
2025-05-08 15:29:10 +01:00
Mark Rutland
cde5c32db5 arm64/fpsimd: Make clone() compatible with ZA lazy saving
Linux is intended to be compatible with userspace written to Arm's
AAPCS64 procedure call standard [1,2]. For the Scalable Matrix Extension
(SME), AAPCS64 was extended with a "ZA lazy saving scheme", where SME's
ZA tile is lazily callee-saved and caller-restored. In this scheme,
TPIDR2_EL0 indicates whether the ZA tile is live or has been saved by
pointing to a "TPIDR2 block" in memory, which has a "za_save_buffer"
pointer. This scheme has been implemented in GCC and LLVM, with
necessary runtime support implemented in glibc and bionic.

AAPCS64 does not specify how the ZA lazy saving scheme is expected to
interact with thread creation mechanisms such as fork() and
pthread_create(), which would be implemented in terms of the Linux clone
syscall. The behaviour implemented by Linux and glibc/bionic doesn't
always compose safely, as explained below.

Currently the clone syscall is implemented such that PSTATE.ZA and the
ZA tile are always inherited by the new task, and TPIDR2_EL0 is
inherited unless the 'flags' argument includes CLONE_SETTLS,
in which case TPIDR2_EL0 is set to 0/NULL. This doesn't make much sense:

(a) TPIDR2_EL0 is part of the calling convention, and changes as control
    is passed between functions. It is *NOT* used for thread local
    storage, despite superficial similarity to TPIDR_EL0, which is is
    used as the TLS register.

(b) TPIDR2_EL0 and PSTATE.ZA are tightly coupled in the procedure call
    standard, and some combinations of states are illegal. In general,
    manipulating the two independently is not guaranteed to be safe.

In practice, code which is compliant with the procedure call standard
may issue a clone syscall while in the "ZA dormant" state, where
PSTATE.ZA==1 and TPIDR2_EL0 is non-null and indicates that ZA needs to
be saved. This can cause a variety of problems, including:

* If the implementation of pthread_create() passes CLONE_SETTLS, the
  new thread will start with PSTATE.ZA==1 and TPIDR2==NULL. Per the
  procedure call standard this is not a legitimate state for most
  functions. This can cause data corruption (e.g. as code may rely on
  PSTATE.ZA being 0 to guarantee that an SMSTART ZA instruction will
  zero the ZA tile contents), and may result in other undefined
  behaviour.

* If the implementation of pthread_create() does not pass CLONE_SETTLS, the
  new thread will start with PSTATE.ZA==1 and TPIDR2 pointing to a
  TPIDR2 block on the parent thread's stack. This can result in a
  variety of problems, e.g.

  - The child may write back to the parent's za_save_buffer, corrupting
    its contents.

  - The child may read from the TPIDR2 block after the parent has reused
    this memory for something else, and consequently the child may abort
    or clobber arbitrary memory.

Ideally we'd require that userspace ensures that a task is in the "ZA
off" state (with PSTATE.ZA==0 and TPIDR2_EL0==NULL) prior to issuing a
clone syscall, and have the kernel force this state for new threads.
Unfortunately, contemporary C libraries do not do this, and simply
forcing this state within the implementation of clone would break
fork().

Instead, we can bodge around this by considering the CLONE_VM flag, and
manipulate PSTATE.ZA and TPIDR2_EL0 as a pair. CLONE_VM indicates that
the new task will run in the same address space as its parent, and in
that case it doesn't make sense to inherit a stale pointer to the
parent's TPIDR2 block:

* For fork(), CLONE_VM will not be set, and it is safe to inherit both
  PSTATE.ZA and TPIDR2_EL0 as the new task will have its own copy of the
  address space, and cannot clobber its parent's stack.

* For pthread_create() and vfork(), CLONE_VM will be set, and discarding
  PSTATE.ZA and TPIDR2_EL0 for the new task doesn't break any existing
  assumptions in userspace.

Implement this behaviour for clone(). We currently inherit PSTATE.ZA in
arch_dup_task_struct(), but this does not have access to the clone
flags, so move this logic under copy_thread(). Documentation is updated
to describe the new behaviour.

[1] https://github.com/ARM-software/abi-aa/releases/download/2025Q1/aapcs64.pdf
[2] c51addc3dc/aapcs64/aapcs64.rst

Suggested-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Daniel Kiss <daniel.kiss@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Richard Sandiford <richard.sandiford@arm.com>
Cc: Sander De Smalen <sander.desmalen@arm.com>
Cc: Tamas Petz <tamas.petz@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yury Khrustalev <yury.khrustalev@arm.com>
Acked-by: Yury Khrustalev <yury.khrustalev@arm.com>
Link: https://lore.kernel.org/r/20250508132644.1395904-14-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
2025-05-08 15:29:10 +01:00
Mark Rutland
a6d066f705 arm64/fpsimd: Clear PSTATE.SM during clone()
Currently arch_dup_task_struct() doesn't handle cases where the parent
task has PSTATE.SM==1. Since syscall entry exits streaming mode, the
parent will usually have PSTATE.SM==0, but this can be change by ptrace
after syscall entry. When this happens, arch_dup_task_struct() will
initialise the new task into an invalid state. The new task inherits the
parent's configuration of PSTATE.SM, but fp_type is set to
FP_STATE_FPSIMD, TIF_SVE and SME may be cleared, and both sve_state and
sme_state may be set to NULL.

This can result in a variety of problems whenever the new task's state
is manipulated, including kernel NULL pointer dereferences and leaking
of streaming mode state between tasks.

When ptrace is not involved, the parent will have PSTATE.SM==0 as a
result of syscall entry, and the documentation in
Documentation/arch/arm64/sme.rst says:

| On process creation (eg, clone()) the newly created process will have
| PSTATE.SM cleared.

... so make this true by using task_smstop_sm() to exit streaming mode
in the child task, avoiding the problems above.

Fixes: 8bd7f91c03 ("arm64/sme: Implement traps and syscall handling for SME")
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20250508132644.1395904-13-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
2025-05-08 15:29:10 +01:00
Mark Rutland
e0cb0f2659 arm64/fpsimd: Consistently preserve FPSIMD state during clone()
In arch_dup_task_struct() we try to ensure that the child task inherits
the FPSIMD state of its parent, but this depends on the parent task's
saved state being in FPSIMD format, which is not always the case.
Consequently the child task may inherit stale FPSIMD state in some
cases.

This can happen when the parent's state has been modified by ptrace
since syscall entry, as writes to the NT_ARM_SVE regset may save state
in SVE format. This has been possible since commit:

  bc0ee47603 ("arm64/sve: Core task context handling")

More recently it has been possible for a task's FPSIMD/SVE state to be
saved before lazy discarding was guaranteed to occur, in which case
preemption could cause the effective FPSIMD state to be saved in SVE
format non-deterministically. This has been possible since commit:

  f130ac0ae4 ("arm64: syscall: unmask DAIF earlier for SVCs")

Fix this by saving the parent task's effective FPSIMD state into FPSIMD
format before copying the task_struct. As this requires modifying the
parent's fpsimd_state, we must save+flush the state to avoid racing with
concurrent manipulation.

Similar issues exist when the parent has streaming mode state, and will
be addressed by subsequent patches.

Fixes: bc0ee47603 ("arm64/sve: Core task context handling")
Fixes: f130ac0ae4 ("arm64: syscall: unmask DAIF earlier for SVCs")
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20250508132644.1395904-12-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
2025-05-08 15:29:10 +01:00
Mark Rutland
8d61eef756 arm64/fpsimd: Remove redundant task->mm check
For historical reasons, arch_dup_task_struct() only calls
fpsimd_preserve_current_state() when current->mm is non-NULL, but this
is no longer necessary.

Historically TIF_FOREIGN_FPSTATE was only managed for user threads, and
was never set for kernel threads. At the time, various functions
attempted to avoid saving/restoring state for kernel threads by checking
task_struct::mm to try to distinguish user threads from kernel threads.

We added the current->mm check to arch_dup_task_struct() in commit:

  6eb6c80187 ("arm64: kernel thread don't need to save fpsimd context.")

... where the intent was to avoid pointlessly saving state for kernel
threads, which never had live state (and the saved state would never be
consumed).

Subsequently we began setting TIF_FOREIGN_FPSTATE for kernel threads,
and removed most of the task_struct::mm checks in commit:

  df3fb96820 ("arm64: fpsimd: Eliminate task->mm checks")

... but we missed the check in arch_dup_task_struct(), which is similarly
redundant.

Remove the redundant check from arch_dup_task_struct().

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20250508132644.1395904-11-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
2025-05-08 15:29:09 +01:00
Mark Rutland
99560c9452 arm64/fpsimd: signal: Use SMSTOP behaviour in setup_return()
Historically the behaviour of setup_return() was nondeterministic,
depending on whether the task's FSIMD/SVE/SME state happened to be live.
We fixed most of that in commit:

  929fa99b12 ("arm64/fpsimd: signal: Always save+flush state early")

... but we didn't decide on how clearing PSTATE.SM should behave, and left a
TODO comment to that effect.

Use the new task_smstop_sm() helper to make this behave as if an SMSTOP
instruction was used to exit streaming mode. This would have been the
most common behaviour prior to the commit above.

Fixes: 40a8e87bb3 ("arm64/sme: Disable ZA and streaming mode when handling signals")
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20250508132644.1395904-10-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
2025-05-08 15:29:09 +01:00
Mark Rutland
6ef1d778ce arm64/fpsimd: Add task_smstop_sm()
In a few places we want to transition a task from streaming mode to
non-streaming mode, e.g. signal delivery where we historically tried to
use an SMSTOP SM instruction.

Add a new helper to manipulate a task's state in the same way as an
SMSTOP SM instruction. I have not added a corresponding helper to
simulate the effects of SMSTART SM. Only ptrace transitions a task into
streaming mode, and ptrace has distinct semantics for such transitions.

Per ARM DDI 0487 L.a, section B1.4.6:

| RRSWFQ
| When the Effective value of PSTATE.SM is changed by any method from 0
| to 1, an entry to Streaming SVE mode is performed, and all implemented
| bits of Streaming SVE register state are set to zero.

| RKFRQZ
| When the Effective value of PSTATE.SM is changed by any method from 1
| to 0, an exit from Streaming SVE mode is performed, and in the
| newly-entered mode, all implemented bits of the SVE scalable vector
| registers, SVE predicate registers, and FFR, are set to zero.

Per ARM DDI 0487 L.a, section C5.2.9:

| On entry to or exit from Streaming SVE mode, FPMR is set to 0

Per ARM DDI 0487 L.a, section C5.2.10:

| On entry to or exit from Streaming SVE mode, FPSR.{IOC, DZC, OFC, UFC,
| IXC, IDC, QC} are set to 1 and the remaining bits are set to 0.

This means bits 0, 1, 2, 3, 4, 7, and 27 respectively, i.e. 0x0800009f

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20250508132644.1395904-9-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
2025-05-08 15:29:09 +01:00
Mark Rutland
8738288a08 arm64/fpsimd: Factor out {sve,sme}_state_size() helpers
In subsequent patches we'll need to determine the SVE/SME state size for
a given SVE VL and SME VL regardless of whether a task is currently
configured with those VLs. Split the sizing logic out of
sve_state_size() and sme_state_size() so that we don't need to open-code
this logic elsewhere.

At the same time, apply minor cleanups:

* Move sve_state_size() into fpsimd.h, matching the placement of
  sme_state_size().

* Remove the feature checks from sve_state_size(). We only call
  sve_state_size() when at least one of SVE and SME are supported, and
  when either of the two is not supported, the task's corresponding
  SVE/SME vector length will be zero.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20250508132644.1395904-8-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
2025-05-08 15:29:09 +01:00
Mark Rutland
b255be4269 arm64/fpsimd: Clarify sve_sync_*() functions
The sve_sync_{to,from}_fpsimd*() functions are intended to
extract/insert the currently effective FPSIMD state of a task regardless
of whether the task's state is saved in FPSIMD format or SVE format.
Historically they were only used by ptrace, but sve_sync_to_fpsimd() is
now used more widely, and sve_sync_from_fpsimd_zeropad() may be used
more widely in future.

When FPSIMD/SVE state tracking was changed across commits:

  baa8515281 ("arm64/fpsimd: Track the saved FPSIMD state type separately to TIF_SVE")
  a0136be443 (arm64/fpsimd: Load FP state based on recorded data type")
  bbc6172eef ("arm64/fpsimd: SME no longer requires SVE register state")
  8c845e2731 ("arm64/sve: Leave SVE enabled on syscall if we don't context switch")

... sve_sync_to_fpsimd() was updated to consider task->thread.fp_type
rather than the task's TIF_SVE and PSTATE.SM, but (apparently due to an
oversight) sve_sync_from_fpsimd_zeropad() was left as-is, leaving the
two inconsistent.

Due to this, sve_sync_from_fpsimd_zeropad() may copy state from
task->thread.uw.fpsimd_state into task->thread.sve_state when
task->thread.fp_type == FP_STATE_FPSIMD. This is redundant (but benign)
as task->thread.uw.fpsimd_state is the effective state that will be
restored, and task->thread.sve_state will not be consumed. For
consistency, and to avoid the redundant work, it better for
sve_sync_from_fpsimd_zeropad() to consider task->thread.fp_type alone,
matching sve_sync_to_fpsimd().

The naming of both functions is somehat unfortunate, as it is unclear
when and why they copy state. It would be better to describe them in
terms of the effective state.

Considering all of the above, clean this up:

* Adjust sve_sync_from_fpsimd_zeropad() to consider
  task->thread.fp_type.

* Update comments to clarify the intended semantics/usage. I've removed
  the description that task->thread.sve_state must have been allocated,
  as this is only necessary when task->thread.fp_type == FP_STATE_SVE,
  which itself implies that task->thread.sve_state must have been
  allocated.

* Rename the functions to more clearly indicate when/why they copy
  state:

  - sve_sync_to_fpsimd() => fpsimd_sync_from_effective_state()

  - sve_sync_from_fpsimd_zeropad => fpsimd_sync_to_effective_state_zeropad()

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20250508132644.1395904-7-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
2025-05-08 15:29:09 +01:00
Mark Rutland
316283f276 arm64/fpsimd: ptrace: Consistently handle partial writes to NT_ARM_(S)SVE
Partial writes to the NT_ARM_SVE and NT_ARM_SSVE regsets using an
payload are handled inconsistently and non-deterministically. A comment
within sve_set_common() indicates that we intended that a partial write
would preserve any effective FPSIMD/SVE state which was not overwritten,
but this has never worked consistently, and during syscalls the FPSIMD
vector state may be non-deterministically preserved and may be
erroneously migrated between streaming and non-streaming SVE modes.

The simplest fix is to handle a partial write by consistently zeroing
the remaining state. As detailed below I do not believe this will
adversely affect any real usage.

Neither GDB nor LLDB attempt partial writes to these regsets, and the
documentation (in Documentation/arch/arm64/sve.rst) has always indicated
that state preservation was not guaranteed, as is says:

| The effect of writing a partial, incomplete payload is unspecified.

When the logic was originally introduced in commit:

  43d4da2c45 ("arm64/sve: ptrace and ELF coredump support")

... there were two potential behaviours, depending on TIF_SVE:

* When TIF_SVE was clear, all SVE state would be zeroed, excluding the
  low 128 bits of vectors shared with FPSIMD, FPSR, and FPCR.

* When TIF_SVE was set, all SVE state would be zeroed, including the
  low 128 bits of vectors shared with FPSIMD, but excluding FPSR and
  FPCR.

Note that as writing to NT_ARM_SVE would set TIF_SVE, partial writes to
NT_ARM_SVE would not be idempotent, and if a first write preserved the
low 128 bits, a subsequent (potentially identical) partial write would
discard the low 128 bits.

When support for the NT_ARM_SSVE regset was added in commit:

  e12310a0d3 ("arm64/sme: Implement ptrace support for streaming mode SVE registers")

... the above behaviour was retained for writes to the NT_ARM_SVE
regset, though writes to the NT_ARM_SSVE would always zero the SVE
registers and would not inherit FPSIMD register state. This happened as
fpsimd_sync_to_sve() only copied the FPSIMD regs when TIF_SVE was clear
and PSTATE.SM==0.

Subsequently, when FPSIMD/SVE state tracking was changed across commits:

  baa8515281 ("arm64/fpsimd: Track the saved FPSIMD state type separately to TIF_SVE")
  a0136be443 (arm64/fpsimd: Load FP state based on recorded data type")
  bbc6172eef ("arm64/fpsimd: SME no longer requires SVE register state")
  8c845e2731 ("arm64/sve: Leave SVE enabled on syscall if we don't context switch")

... there was no corresponding update to the ptrace code, nor to
fpsimd_sync_to_sve(), which stil considers TIF_SVE and PSTATE.SM rather
than the saved fp_type. The saved state can be in the FPSIMD format
regardless of whether TIF_SVE is set or clear, and the saved type can
change non-deterministically during syscalls. Consequently a subsequent
partial write to the NT_ARM_SVE or NT_ARM_SSVE regsets may
non-deterministically preserve the FPSIMD state, and may migrate this
state between streaming and non-streaming modes.

Clean this up by never attempting to preserve ANY state when writing an
SVE payload to the NT_ARM_SVE/NT_ARM_SSVE regsets, zeroing all relevant
state including FPSR and FPCR. This simplifies the code, makes the
behaviour deterministic, and avoids migrating state between streaming
and non-streaming modes. As above, I do not believe this should
adversely affect existing userspace applications.

At the same time, remove fpsimd_sync_to_sve(). It is no longer used,
doesn't do what its documentation implies, and gets in the way of other
cleanups and fixes.

Fixes: 43d4da2c45 ("arm64/sve: ptrace and ELF coredump support")
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Spickett <david.spickett@arm.com>
Cc: Luis Machado <luis.machado@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20250508132644.1395904-6-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
2025-05-08 15:29:08 +01:00
James Morse
0dfefc2ea2 arm64: bpf: Add BHB mitigation to the epilogue for cBPF programs
A malicious BPF program may manipulate the branch history to influence
what the hardware speculates will happen next.

On exit from a BPF program, emit the BHB mititgation sequence.

This is only applied for 'classic' cBPF programs that are loaded by
seccomp.

Signed-off-by: James Morse <james.morse@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
2025-05-08 15:28:35 +01:00
James Morse
a1152be30a arm64: proton-pack: Expose whether the branchy loop k value
Add a helper to expose the k value of the branchy loop. This is needed
by the BPF JIT to generate the mitigation sequence in BPF programs.

Signed-off-by: James Morse <james.morse@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
2025-05-08 15:28:35 +01:00
James Morse
e7956c92f3 arm64: proton-pack: Expose whether the platform is mitigated by firmware
is_spectre_bhb_fw_affected() allows the caller to determine if the CPU
is known to need a firmware mitigation. CPUs are either on the list
of CPUs we know about, or firmware has been queried and reported that
the platform is affected - and mitigated by firmware.

This helper is not useful to determine if the platform is mitigated
by firmware. A CPU could be on the know list, but the firmware may
not be implemented. Its affected but not mitigated.

spectre_bhb_enable_mitigation() handles this distinction by checking
the firmware state before enabling the mitigation.

Add a helper to expose this state. This will be used by the BPF JIT
to determine if calling firmware for a mitigation is necessary and
supported.

Signed-off-by: James Morse <james.morse@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
2025-05-08 15:28:35 +01:00
Mark Rutland
be625d803c arm64/fpsimd: signal: Consistently read FPSIMD context
For historical reasons, restore_sve_fpsimd_context() has an open-coded
copy of the logic from read_fpsimd_context(), which is used to either
restore an FPSIMD-only context, or to merge FPSIMD state into an
SVE state when restoring an SVE+FPSIMD context. The logic is *almost*
identical.

Refactor the logic to avoid duplication and make this clearer.

This comes with two functional changes that I do not believe will be
problematic in practice:

* The user_fpsimd_state::size field will be checked in all restore paths
  that consume it user_fpsimd_state. The kernel always populates this
  field when delivering a signal, and so this should contain the
  expected value unless it has been corrupted.

* If a read of user_fpsimd_state fails, we will return early without
  modifying TIF_SVE, the saved SVCR, or the save fp_type. This will
  leave the task in a consistent state, without potentially resurrecting
  stale FPSIMD state. A read of user_fpsimd_state should never fail
  unless the structure has been corrupted or the stack has been
  unmapped.

Suggested-by: Will Deacon <will@kernel.org>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20250508132644.1395904-5-mark.rutland@arm.com
[will: Ensure read_fpsimd_context() returns negative error code or zero]
Signed-off-by: Will Deacon <will@kernel.org>
2025-05-08 15:28:27 +01:00
Mark Rutland
b465ace426 arm64/fpsimd: signal: Mandate SVE payload for streaming-mode state
Non-streaming SVE state may be preserved without an SVE payload, in
which case the SVE context only has a header with VL==0, and all state
can be restored from the FPSIMD context. Streaming SVE state is always
preserved with an SVE payload, where the SVE context header has VL!=0,
and the SVE_SIG_FLAG_SM flag is set.

The kernel never preserves an SVE context where SVE_SIG_FLAG_SM is set
without an SVE payload. However, restore_sve_fpsimd_context() doesn't
forbid restoring such a context, and will handle this case by clearing
PSTATE.SM and restoring the FPSIMD context into non-streaming mode,
which isn't consistent with the SVE_SIG_FLAG_SM flag.

Forbid this case, and mandate an SVE payload when the SVE_SIG_FLAG_SM
flag is set. This avoids an awkward ABI quirk and reduces the risk that
later rework to this code permits configuring a task with PSTATE.SM==1
and fp_type==FP_STATE_FPSIMD.

I've marked this as a fix given that we never intended to support this
case, and we don't want anyone to start relying upon the old behaviour
once we re-enable SME.

Fixes: 85ed24dad2 ("arm64/sme: Implement streaming SVE signal handling")
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Will Deacon <will@kernel.org>
Reviewed-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20250508132644.1395904-4-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
2025-05-08 15:23:36 +01:00
Mark Rutland
1bf663a86a arm64/fpsimd: signal: Clear PSTATE.SM when restoring FPSIMD frame only
On systems with SVE and/or SME, the kernel will always create SVE and
FPSIMD signal frames when delivering a signal, but a user can manipulate
signal frames such that a signal return only observes an FPSIMD signal
frame. When this happens, restore_fpsimd_context() will restore state
such that fp_type==FP_STATE_FPSIMD, but will leave PSTATE.SM as-is.

It is possible for a user to set PSTATE.SM between syscall entry and
execution of the sigreturn logic (e.g. via ptrace), and consequently the
sigreturn may result in the task having PSTATE.SM==1 and
fp_type==FP_STATE_FPSIMD.

For various reasons it is not legitimate for a task to be in a state
where PSTATE.SM==1 and fp_type==FP_STATE_FPSIMD. Portions of the user
ABI are written with the requirement that streaming SVE state is always
presented in SVE format rather than FPSIMD format, and as there is no
mechanism to permit access to only the FPSIMD subset of streaming SVE
state, streaming SVE state must always be saved and restored in SVE
format.

Fix restore_fpsimd_context() to clear PSTATE.SM when restoring an FPSIMD
signal frame without an SVE signal frame. This matches the current
behaviour when an SVE signal frame is present, but the SVE signal frame
has no register payload (e.g. as is the case on SME-only systems which
lack SVE).

This change should have no effect for applications which do not alter
signal frames (i.e. almost all applications). I do not expect
non-{malicious,buggy} applications to hide the SVE signal frame, but
I've chosen to clear PSTATE.SM rather than mandating the presence of an
SVE signal frame in case there is some legacy (non-SME) usage that I am
not currently aware of.

For context, the SME handling was originally introduced in commit:

  85ed24dad2 ("arm64/sme: Implement streaming SVE signal handling")

... and subsequently updated/fixed to handle SME-only systems in commits:

  7dde62f068 ("arm64/signal: Always accept SVE signal frames on SME only systems")
  f26cd73721 ("arm64/signal: Always allocate SVE signal frames on SME only systems")

Fixes: 85ed24dad2 ("arm64/sme: Implement streaming SVE signal handling")
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20250508132644.1395904-3-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
2025-05-08 15:23:36 +01:00
Mark Rutland
398edaa12f arm64/fpsimd: Do not discard modified SVE state
Historically SVE state was discarded deterministically early in the
syscall entry path, before ptrace is notified of syscall entry. This
permitted ptrace to modify SVE state before and after the "real" syscall
logic was executed, with the modified state being retained.

This behaviour was changed by commit:

  8c845e2731 ("arm64/sve: Leave SVE enabled on syscall if we don't context switch")

That commit was intended to speed up workloads that used SVE by
opportunistically leaving SVE enabled when returning from a syscall.
The syscall entry logic was modified to truncate the SVE state without
disabling userspace access to SVE, and fpsimd_save_user_state() was
modified to discard userspace SVE state whenever
in_syscall(current_pt_regs()) is true, i.e. when
current_pt_regs()->syscallno != NO_SYSCALL.

Leaving SVE enabled opportunistically resulted in a couple of changes to
userspace visible behaviour which weren't described at the time, but are
logical consequences of opportunistically leaving SVE enabled:

* Signal handlers can observe the type of saved state in the signal's
  sve_context record. When the kernel only tracks FPSIMD state, the 'vq'
  field is 0 and there is no space allocated for register contents. When
  the kernel tracks SVE state, the 'vq' field is non-zero and the
  register contents are saved into the record.

  As a result of the above commit, 'vq' (and the presence of SVE
  register state) is non-deterministically zero or non-zero for a period
  of time after a syscall. The effective register state is still
  deterministic.

  Hopefully no-one relies on this being deterministic. In general,
  handlers for asynchronous events cannot expect a deterministic state.

* Similarly to signal handlers, ptrace requests can observe the type of
  saved state in the NT_ARM_SVE and NT_ARM_SSVE regsets, as this is
  exposed in the header flags. As a result of the above commit, this is
  now in a non-deterministic state after a syscall. The effective
  register state is still deterministic.

  Hopefully no-one relies on this being deterministic. In general,
  debuggers would have to handle this changing at arbitrary points
  during program flow.

Discarding the SVE state within fpsimd_save_user_state() resulted in
other changes to userspace visible behaviour which are not desirable:

* A ptrace tracer can modify (or create) a tracee's SVE state at syscall
  entry or syscall exit. As a result of the above commit, the tracee's
  SVE state can be discarded non-deterministically after modification,
  rather than being retained as it previously was.

  Note that for co-operative tracer/tracee pairs, the tracer may
  (re)initialise the tracee's state arbitrarily after the tracee sends
  itself an initial SIGSTOP via a syscall, so this affects realistic
  design patterns.

* The current_pt_regs()->syscallno field can be modified via ptrace, and
  can be altered even when the tracee is not really in a syscall,
  causing non-deterministic discarding to occur in situations where this
  was not previously possible.

Further, using current_pt_regs()->syscallno in this way is unsound:

* There are data races between readers and writers of the
  current_pt_regs()->syscallno field.

  The current_pt_regs()->syscallno field is written in interruptible
  task context using plain C accesses, and is read in irq/softirq
  context using plain C accesses. These accesses are subject to data
  races, with the usual concerns with tearing, etc.

* Writes to current_pt_regs()->syscallno are subject to compiler
  reordering.

  As current_pt_regs()->syscallno is written with plain C accesses,
  the compiler is free to move those writes arbitrarily relative to
  anything which doesn't access the same memory location.

  In theory this could break signal return, where prior to restoring the
  SVE state, restore_sigframe() calls forget_syscall(). If the write
  were hoisted after restore of some SVE state, that state could be
  discarded unexpectedly.

  In practice that reordering cannot happen in the absence of LTO (as
  cross compilation-unit function calls happen prevent this reordering),
  and that reordering appears to be unlikely in the presence of LTO.

Additionally, since commit:

  f130ac0ae4 ("arm64: syscall: unmask DAIF earlier for SVCs")

... DAIF is unmasked before el0_svc_common() sets regs->syscallno to the
real syscall number. Consequently state may be saved in SVE format prior
to this point.

Considering all of the above, current_pt_regs()->syscallno should not be
used to infer whether the SVE state can be discarded. Luckily we can
instead use cpu_fp_state::to_save to track when it is safe to discard
the SVE state:

* At syscall entry, after the live SVE register state is truncated, set
  cpu_fp_state::to_save to FP_STATE_FPSIMD to indicate that only the
  FPSIMD portion is live and needs to be saved.

* At syscall exit, once the task's state is guaranteed to be live, set
  cpu_fp_state::to_save to FP_STATE_CURRENT to indicate that TIF_SVE
  must be considered to determine which state needs to be saved.

* Whenever state is modified, it must be saved+flushed prior to
  manipulation. The state will be truncated if necessary when it is
  saved, and reloading the state will set fp_state::to_save to
  FP_STATE_CURRENT, preventing subsequent discarding.

This permits SVE state to be discarded *only* when it is known to have
been truncated (and the non-FPSIMD portions must be zero), and ensures
that SVE state is retained after it is explicitly modified.

For backporting, note that this fix depends on the following commits:

* b2482807fb ("arm64/sme: Optimise SME exit on syscall entry")
* f130ac0ae4 ("arm64: syscall: unmask DAIF earlier for SVCs")
* 929fa99b12 ("arm64/fpsimd: signal: Always save+flush state early")

Fixes: 8c845e2731 ("arm64/sve: Leave SVE enabled on syscall if we don't context switch")
Fixes: f130ac0ae4 ("arm64: syscall: unmask DAIF earlier for SVCs")
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20250508132644.1395904-2-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
2025-05-08 15:23:35 +01:00
Mostafa Saleh
d683a85618 ubsan: Remove regs from report_ubsan_failure()
report_ubsan_failure() doesn't use argument regs, and soon it will
be called from the hypervisor context were regs are not available.
So, remove the unused argument.

Signed-off-by: Mostafa Saleh <smostafa@google.com>
Acked-by: Kees Cook <kees@kernel.org>
Link: https://lore.kernel.org/r/20250430162713.1997569-3-smostafa@google.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-05-07 11:21:35 +01:00
Mostafa Saleh
dc1fd37a7f arm64: Introduce esr_is_ubsan_brk()
Soon, KVM is going to use this logic for hypervisor panics,
so add it in a wrapper that can be used by the hypervisor exit
handler to decode hyp panics.

Signed-off-by: Mostafa Saleh <smostafa@google.com>
Reviewed-by: Kees Cook <kees@kernel.org>
Link: https://lore.kernel.org/r/20250430162713.1997569-2-smostafa@google.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-05-07 11:21:35 +01:00
Marc Zyngier
fbc8a4e137 arm64: Add FEAT_FGT2 capability
As we will eventually have to context-switch the FEAT_FGT2 registers
in KVM (something that has been completely ignored so far), add
a new cap that we will be able to check for.

Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-05-06 17:35:09 +01:00
Yeoreum Yun
363cd2b81c arm64: cpufeature: Move arm64_use_ng_mappings to the .data section to prevent wrong idmap generation
The PTE_MAYBE_NG macro sets the nG page table bit according to the value
of "arm64_use_ng_mappings". This variable is currently placed in the
.bss section. create_init_idmap() is called before the .bss section
initialisation which is done in early_map_kernel(). Therefore,
data/test_prot in create_init_idmap() could be set incorrectly through
the PAGE_KERNEL -> PROT_DEFAULT -> PTE_MAYBE_NG macros.

   # llvm-objdump-21 --syms vmlinux-gcc | grep arm64_use_ng_mappings
     ffff800082f242a8 g     O .bss    0000000000000001 arm64_use_ng_mappings

The create_init_idmap() function disassembly compiled with llvm-21:

  // create_init_idmap()
  ffff80008255c058: d10103ff     	sub	sp, sp, #0x40
  ffff80008255c05c: a9017bfd     	stp	x29, x30, [sp, #0x10]
  ffff80008255c060: a90257f6     	stp	x22, x21, [sp, #0x20]
  ffff80008255c064: a9034ff4     	stp	x20, x19, [sp, #0x30]
  ffff80008255c068: 910043fd     	add	x29, sp, #0x10
  ffff80008255c06c: 90003fc8     	adrp	x8, 0xffff800082d54000
  ffff80008255c070: d280e06a     	mov	x10, #0x703     // =1795
  ffff80008255c074: 91400409     	add	x9, x0, #0x1, lsl #12 // =0x1000
  ffff80008255c078: 394a4108     	ldrb	w8, [x8, #0x290] ------------- (1)
  ffff80008255c07c: f2e00d0a     	movk	x10, #0x68, lsl #48
  ffff80008255c080: f90007e9     	str	x9, [sp, #0x8]
  ffff80008255c084: aa0103f3     	mov	x19, x1
  ffff80008255c088: aa0003f4     	mov	x20, x0
  ffff80008255c08c: 14000000     	b	0xffff80008255c08c <__pi_create_init_idmap+0x34>
  ffff80008255c090: aa082d56     	orr	x22, x10, x8, lsl #11 -------- (2)

Note (1) is loading the arm64_use_ng_mappings value in w8 and (2) is set
the text or data prot with the w8 value to set PTE_NG bit. If the .bss
section isn't initialized, x8 could include a garbage value and generate
an incorrect mapping.

Annotate arm64_use_ng_mappings as __read_mostly so that it is placed in
the .data section.

Fixes: 84b04d3e6b ("arm64: kernel: Create initial ID map from C code")
Cc: stable@vger.kernel.org # 6.9.x
Tested-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Yeoreum Yun <yeoreum.yun@arm.com>
Link: https://lore.kernel.org/r/20250502180412.3774883-1-yeoreum.yun@arm.com
[catalin.marinas@arm.com: use __read_mostly instead of __ro_after_init]
[catalin.marinas@arm.com: slight tweaking of the code comment]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2025-05-06 11:43:44 +01:00
David Brazdil
74b13d5816 KVM: arm64: Add .hyp.data section
The hypervisor has not needed its own .data section because all globals
were either .rodata or .bss. To avoid having to initialize future
data-structures at run-time, let's introduce add a .data section to the
hypervisor.

Signed-off-by: David Brazdil <dbrazdil@google.com>
Signed-off-by: Quentin Perret <qperret@google.com>
Link: https://lore.kernel.org/r/20250416160900.3078417-2-qperret@google.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-05-06 09:56:18 +01:00
Linus Torvalds
e8ab83e34b Add missing sentinels to the arm64 Spectre-BHB MIDR arrays, otherwise
is_midr_in_range_list() reads beyond the end of these arrays.
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Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 fix from Catalin Marinas:
 "Add missing sentinels to the arm64 Spectre-BHB MIDR arrays, otherwise
  is_midr_in_range_list() reads beyond the end of these arrays"

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: errata: Add missing sentinels to Spectre-BHB MIDR arrays
2025-05-03 16:30:53 -07:00
Will Deacon
fee4d17145 arm64: errata: Add missing sentinels to Spectre-BHB MIDR arrays
Commit a5951389e5 ("arm64: errata: Add newer ARM cores to the
spectre_bhb_loop_affected() lists") added some additional CPUs to the
Spectre-BHB workaround, including some new arrays for designs that
require new 'k' values for the workaround to be effective.

Unfortunately, the new arrays omitted the sentinel entry and so
is_midr_in_range_list() will walk off the end when it doesn't find a
match. With UBSAN enabled, this leads to a crash during boot when
is_midr_in_range_list() is inlined (which was more common prior to
c8c2647e69 ("arm64: Make  _midr_in_range_list() an exported
function")):

 |  Internal error: aarch64 BRK: 00000000f2000001 [#1] PREEMPT SMP
 |  pstate: 804000c5 (Nzcv daIF +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
 |  pc : spectre_bhb_loop_affected+0x28/0x30
 |  lr : is_spectre_bhb_affected+0x170/0x190
 | [...]
 |  Call trace:
 |   spectre_bhb_loop_affected+0x28/0x30
 |   update_cpu_capabilities+0xc0/0x184
 |   init_cpu_features+0x188/0x1a4
 |   cpuinfo_store_boot_cpu+0x4c/0x60
 |   smp_prepare_boot_cpu+0x38/0x54
 |   start_kernel+0x8c/0x478
 |   __primary_switched+0xc8/0xd4
 |  Code: 6b09011f 54000061 52801080 d65f03c0 (d4200020)
 |  ---[ end trace 0000000000000000 ]---
 |  Kernel panic - not syncing: aarch64 BRK: Fatal exception

Add the missing sentinel entries.

Cc: Lee Jones <lee@kernel.org>
Cc: James Morse <james.morse@arm.com>
Cc: Doug Anderson <dianders@chromium.org>
Cc: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Cc: <stable@vger.kernel.org>
Reported-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fixes: a5951389e5 ("arm64: errata: Add newer ARM cores to the spectre_bhb_loop_affected() lists")
Signed-off-by: Will Deacon <will@kernel.org>
Reviewed-by: Lee Jones <lee@kernel.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20250501104747.28431-1-will@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2025-05-01 17:44:18 +01:00
Mark Rutland
f699c66691 arm64/fpsimd: Avoid warning when sve_to_fpsimd() is unused
Historically fpsimd_to_sve() and sve_to_fpsimd() were (conditionally)
called by functions which were defined regardless of CONFIG_ARM64_SVE.
Hence it was necessary that both fpsimd_to_sve() and sve_to_fpsimd()
were always defined and not guarded by ifdeffery.

As a result of the removal of fpsimd_signal_preserve_current_state() in
commit:

  929fa99b12 ("arm64/fpsimd: signal: Always save+flush state early")

... sve_to_fpsimd() has no callers when CONFIG_ARM64_SVE=n, resulting in
a build-time warnign that it is unused:

| arch/arm64/kernel/fpsimd.c:676:13: warning: unused function 'sve_to_fpsimd' [-Wunused-function]
|   676 | static void sve_to_fpsimd(struct task_struct *task)
|       |             ^~~~~~~~~~~~~
| 1 warning generated.

In contrast, fpsimd_to_sve() still has callers which are defined when
CONFIG_ARM64_SVE=n, and it would be awkward to hide this behind
ifdeffery and/or to use stub functions.

For now, suppress the warning by marking both fpsimd_to_sve() and
sve_to_fpsimd() as 'static inline', as we usually do for stub functions.
The compiler will no longer warn if either function is unused.

Aside from suppressing the warning, there should be no functional change
as a result of this patch.

Link: https://lore.kernel.org/linux-arm-kernel/20250429194600.GA26883@willie-the-truck/
Reported-by: Will Deacon <will@kernel.org>
Fixes: 929fa99b12 ("arm64/fpsimd: signal: Always save+flush state early")
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20250430173240.4023627-1-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2025-04-30 18:52:15 +01:00
Bartosz Szczepanek
83a39eccdf arm64: Extend pr_crit message on invalid FDT
Log size in addition to physical and virtual addresses. It has potential
to be helpful when DTB exceeds the 2 MB limit.

Initialize size to 0 to print out sane value if fixmap_remap_fdt fails
without setting the size.

Signed-off-by: Bartosz Szczepanek <bsz@amazon.de>
Link: https://lore.kernel.org/r/20250423084851.26449-1-bsz@amazon.de
Signed-off-by: Will Deacon <will@kernel.org>
2025-04-29 16:23:57 +01:00
Oliver Upton
17efc1acee arm64: Expose AIDR_EL1 via sysfs
The KVM PV ABI recently added a feature that allows the VM to discover
the set of physical CPU implementations, identified by a tuple of
{MIDR_EL1, REVIDR_EL1, AIDR_EL1}. Unlike other KVM PV features, the
expectation is that the VMM implements the hypercall instead of KVM as
it has the authoritative view of where the VM gets scheduled.

To do this the VMM needs to know the values of these registers on any
CPU in the system. While MIDR_EL1 and REVIDR_EL1 are already exposed,
AIDR_EL1 is not. Provide it in sysfs along with the other identification
registers.

Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Link: https://lore.kernel.org/r/20250403231626.3181116-1-oliver.upton@linux.dev
Signed-off-by: Will Deacon <will@kernel.org>
2025-04-29 14:03:18 +01:00
Mark Rutland
c8597e2dd8 arm64: enable PREEMPT_LAZY
For an architecture to enable CONFIG_ARCH_HAS_RESCHED_LAZY, two things are
required:
1) Adding a TIF_NEED_RESCHED_LAZY flag definition
2) Checking for TIF_NEED_RESCHED_LAZY in the appropriate locations

2) is handled in a generic manner by CONFIG_GENERIC_ENTRY, which isn't
(yet) implemented for arm64. However, outside of core scheduler code,
TIF_NEED_RESCHED_LAZY only needs to be checked on a kernel exit, meaning:
o return/entry to userspace.
o return/entry to guest.

The return/entry to a guest is all handled by xfer_to_guest_mode_handle_work()
which already does the right thing, so it can be left as-is.

arm64 doesn't use common entry's exit_to_user_mode_prepare(), so update its
return to user path to check for TIF_NEED_RESCHED_LAZY and call into
schedule() accordingly.

Link: https://lore.kernel.org/linux-rt-users/20241216190451.1c61977c@mordecai.tesarici.cz/
Link: https://lore.kernel.org/all/xhsmh4j0fl0p3.mognet@vschneid-thinkpadt14sgen2i.remote.csb/
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
[testdrive, _TIF_WORK_MASK fixlet and changelog.]
Signed-off-by: Mike Galbraith <efault@gmx.de>
[Another round of testing; changelog faff]
Signed-off-by: Valentin Schneider <vschneid@redhat.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://lore.kernel.org/r/20250305104925.189198-2-vschneid@redhat.com
Signed-off-by: Will Deacon <will@kernel.org>
2025-04-29 13:44:47 +01:00
Yicong Yang
35382a3646 arm64/cpufeature: Add missing id_aa64mmfr4 feature reg update
Add missing id_aa64mmfr4 feature register check and update in
update_cpu_features(). Update the taint status as well.

Signed-off-by: Yicong Yang <yangyicong@hisilicon.com>
Link: https://lore.kernel.org/r/20250329034409.21354-2-yangyicong@huawei.com
Signed-off-by: Will Deacon <will@kernel.org>
2025-04-29 13:36:37 +01:00
Ard Biesheuvel
1db780bafa arm64/mm: Remove randomization of the linear map
Since commit

  97d6786e06 ("arm64: mm: account for hotplug memory when randomizing the linear region")

the decision whether or not to randomize the placement of the system's
DRAM inside the linear map is based on the capabilities of the CPU
rather than how much memory is present at boot time. This change was
necessary because memory hotplug may result in DRAM appearing in places
that are not covered by the linear region at all (and therefore
unusable) if the decision is solely based on the memory map at boot.

In the Android GKI kernel, which requires support for memory hotplug,
and is built with a reduced virtual address space of only 39 bits wide,
randomization of the linear map never happens in practice as a result.
And even on arm64 kernels built with support for 48 bit virtual
addressing, the wider PArange of recent CPUs means that linear map
randomization is slowly becoming a feature that only works on systems
that will soon be obsolete.

So let's just remove this feature. We can always bring it back in an
improved form if there is a real need for it.

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Kees Cook <kees@kernel.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20250318134949.3194334-2-ardb+git@google.com
Signed-off-by: Will Deacon <will@kernel.org>
2025-04-29 13:21:49 +01:00
Ard Biesheuvel
e04796c8b5 arm64/fpsimd: Avoid unnecessary per-CPU buffers for EFI runtime calls
The EFI specification has some elaborate rules about which runtime
services may be called while another runtime service call is already in
progress. In Linux, however, for simplicity, all EFI runtime service
invocations are serialized via the efi_runtime_lock semaphore.

This implies that calls to the helper pair arch_efi_call_virt_setup()
and arch_efi_call_virt_teardown() are serialized too, and are guaranteed
not to nest.  Furthermore, the arm64 arch code has its own spinlock to
serialize use of the EFI runtime stack, of which only a single instance
exists.

This all means that the FP/SIMD and SVE state preserve/restore logic in
__efi_fpsimd_begin() and __efi_fpsimd_end() are also serialized, and
only a single instance of the associated per-CPU variables can ever be
in use at the same time. There is therefore no need at all for per-CPU
variables here, and they can all be replaced with singleton instances.
This saves a non-trivial amount of memory on systems with many CPUs.

To be more robust against potential future changes in the core EFI code
that may invalidate the reasoning above, move the invocations of
__efi_fpsimd_begin() and __efi_fpsimd_end() into the critical section
covered by the efi_rt_lock spinlock.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20250318132421.3155799-2-ardb+git@google.com
Signed-off-by: Will Deacon <will@kernel.org>
2025-04-29 13:13:52 +01:00
Mark Rutland
b376108e1f arm64/fpsimd: signal: Clear TPIDR2 when delivering signals
Linux is intended to be compatible with userspace written to Arm's
AAPCS64 procedure call standard [1,2]. For the Scalable Matrix Extension
(SME), AAPCS64 was extended with a "ZA lazy saving scheme", where SME's
ZA tile is lazily callee-saved and caller-restored. In this scheme,
TPIDR2_EL0 indicates whether the ZA tile is live or has been saved by
pointing to a "TPIDR2 block" in memory, which has a "za_save_buffer"
pointer. This scheme has been implemented in GCC and LLVM, with
necessary runtime support implemented in glibc.

AAPCS64 does not specify how the ZA lazy saving scheme is expected to
interact with signal handling, and the behaviour that AAPCS64 currently
recommends for (sig)setjmp() and (sig)longjmp() does not always compose
safely with signal handling, as explained below.

When Linux delivers a signal, it creates signal frames which contain the
original values of PSTATE.ZA, the ZA tile, and TPIDR_EL2. Between saving
the original state and entering the signal handler, Linux clears
PSTATE.ZA, but leaves TPIDR2_EL0 unchanged. Consequently a signal
handler can be entered with PSTATE.ZA=0 (meaning accesses to ZA will
trap), while TPIDR_EL0 is non-null (which may indicate that ZA needs to
be lazily saved, depending on the contents of the TPIDR2 block). While
in this state, libc and/or compiler runtime code, such as longjmp(), may
attempt to save ZA. As PSTATE.ZA=0, these accesses will trap, causing
the kernel to inject a SIGILL. Note that by virtue of lazy saving
occurring in libc and/or C runtime code, this can be triggered by
application/library code which is unaware of SME.

To avoid the problem above, the kernel must ensure that signal handlers
are entered with PSTATE.ZA and TPIDR2_EL0 configured in a manner which
complies with the ZA lazy saving scheme. Practically speaking, the only
choice is to enter signal handlers with PSTATE.ZA=0 and TPIDR2_EL0=NULL.
This change should not impact SME code which does not follow the ZA lazy
saving scheme (and hence does not use TPIDR2_EL0).

An alternative approach that was considered is to have the signal
handler inherit the original values of both PSTATE.ZA and TPIDR2_EL0,
relying on lazy save/restore sequences being idempotent and capable of
racing safely. This is not safe as signal handlers must be assumed to
have a "private ZA" interface, and therefore cannot be entered with
PSTATE.ZA=1 and TPIDR2_EL0=NULL, but it is legitimate for signals to be
taken from this state.

With the kernel fixed to clear TPIDR2_EL0, there are a couple of
remaining issues (largely masked by the first issue) that must be fixed
in userspace:

(1) When a (sig)setjmp() + (sig)longjmp() pair cross a signal boundary,
    ZA state may be discarded when it needs to be preserved.

    Currently, the ZA lazy saving scheme recommends that setjmp() does
    not save ZA, and recommends that longjmp() is responsible for saving
    ZA. A call to longjmp() in a signal handler will not have visibility
    of ZA state that existed prior to entry to the signal, and when a
    longjmp() is used to bypass a usual signal return, unsaved ZA state
    will be discarded erroneously.

    To fix this, it is necessary for setjmp() to eagerly save ZA state,
    and for longjmp() to configure PSTATE.ZA=0 and TPIDR2_EL0=NULL. This
    works regardless of whether a signal boundary is crossed.

(2) When a C++ exception is thrown and crosses a signal boundary before
    it is caught, ZA state may be discarded when it needs to be
    preserved.

    AAPCS64 requires that exception handlers are entered with
    PSTATE.{SM,ZA}={0,0} and TPIDR2_EL0=NULL, with exception unwind code
    expected to perform any necessary save of ZA state.

    Where it is necessary to perform an exception unwind across an
    exception boundary, the unwind code must recover any necessary ZA
    state (along with TPIDR2) from signal frames.

Fix the kernel as described above, with setup_return() clearing
TPIDR2_EL0 when delivering a signal. Folk on CC are working on fixes for
the remaining userspace issues, including updates/fixes to the AAPCS64
specification and glibc.

[1] https://github.com/ARM-software/abi-aa/releases/download/2025Q1/aapcs64.pdf
[2] c51addc3dc/aapcs64/aapcs64.rst

Fixes: 39782210eb ("arm64/sme: Implement ZA signal handling")
Fixes: 39e5449928 ("arm64/signal: Include TPIDR2 in the signal context")
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Daniel Kiss <daniel.kiss@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Richard Sandiford <richard.sandiford@arm.com>
Cc: Sander De Smalen <sander.desmalen@arm.com>
Cc: Tamas Petz <tamas.petz@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yury Khrustalev <yury.khrustalev@arm.com>
Link: https://lore.kernel.org/r/20250417190113.3778111-1-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2025-04-28 20:23:06 +01:00
Paolo Bonzini
2d7124941a KVM/arm64 fixes for 6.15, round #2
- Single fix for broken usage of 'multi-MIDR' infrastructure in PI
    code, adding an open-coded erratum check for everyone's favorite pile
    of sand: Cavium ThunderX
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Merge tag 'kvmarm-fixes-6.15-2' of https://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm64 fixes for 6.15, round #2

 - Single fix for broken usage of 'multi-MIDR' infrastructure in PI
   code, adding an open-coded erratum check for everyone's favorite pile
   of sand: Cavium ThunderX
2025-04-24 13:28:53 -04:00
Marc Zyngier
117c3b21d3 arm64: Rework checks for broken Cavium HW in the PI code
Calling into the MIDR checking framework from the PI code has recently
become much harder, due to the new fancy "multi-MIDR" support that
relies on tables being populated at boot time, but not that early that
they are available to the PI code. There are additional issues with
this framework, as the code really isn't position independend *at all*.

This leads to some ugly breakages, as reported by Ada.

It so appears that the only reason for the PI code to call into the
MIDR checking code is to cope with The Most Broken ARM64 System Ever,
aka Cavium ThunderX, which cannot deal with nG attributes that result
of the combination of KASLR and KPTI as a consequence of Erratum 27456.

Duplicate the check for the erratum in the PI code, removing the
dependency on the bulk of the MIDR checking framework. This allows
dropping that same check from kaslr_requires_kpti(), as the KPTI code
already relies on the ARM64_WORKAROUND_CAVIUM_27456 cap.

Fixes: c8c2647e69 ("arm64: Make  _midr_in_range_list() an exported function")
Reported-by: Ada Couprie Diaz <ada.coupriediaz@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/3d97e45a-23cf-419b-9b6f-140b4d88de7b@arm.com
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Cc: Oliver Upton <oliver.upton@linux.dev>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20250418093129.1755739-1-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-04-18 13:51:07 -07:00
Mark Rutland
2fe2b96c38 arm64/fpsimd: signal: Simplify preserve_tpidr2_context()
During a context-switch, tls_thread_switch() reads and writes a task's
thread_struct::tpidr2_el0 field. Other code shouldn't access this field
for an active task, as such accesses would form a data-race with a
concurrent context-switch.

The usage in preserve_tpidr2_context() is suspicious, but benign as any
race with a context switch will write the same value back to
current->thread.tpidr2_el0.

Make this clearer and match restore_tpidr2_context() by using a
temporary variable instead, avoiding the (benign) data-race.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Will Deacon <will@kernel.org>
Reviewed-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20250409164010.3480271-14-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2025-04-09 18:06:31 +01:00
Mark Rutland
929fa99b12 arm64/fpsimd: signal: Always save+flush state early
There are several issues with the way the native signal handling code
manipulates FPSIMD/SVE/SME state, described in detail below. These
issues largely result from races with preemption and inconsistent
handling of live state vs saved state.

Known issues with native FPSIMD/SVE/SME state management include:

* On systems with FPMR, the code to save/restore the FPMR accesses the
  register while it is not owned by the current task. Consequently, this
  may corrupt the FPMR of the current task and/or may corrupt the FPMR
  of an unrelated task. The FPMR save/restore has been broken since it
  was introduced in commit:

    8c46def444 ("arm64/signal: Add FPMR signal handling")

* On systems with SME, setup_return() modifies both the live register
  state and the saved state register state regardless of whether the
  task's state is live, and without holding the cpu fpsimd context.
  Consequently:

  - This may corrupt the state an unrelated task which has PSTATE.SM set
    and/or PSTATE.ZA set.

  - The task may enter the signal handler in streaming mode, and or with
    ZA storage enabled unexpectedly.

  - The task may enter the signal handler in non-streaming SVE mode with
    stale SVE register state, which may have been inherited from
    streaming SVE mode unexpectedly. Where the streaming and
    non-streaming vector lengths differ, this may be packed into
    registers arbitrarily.

  This logic has been broken since it was introduced in commit:

    40a8e87bb3 ("arm64/sme: Disable ZA and streaming mode when handling signals")

  Further incorrect manipulation of state was added in commits:

    ea64baacbc ("arm64/signal: Flush FPSIMD register state when disabling streaming mode")
    baa8515281 ("arm64/fpsimd: Track the saved FPSIMD state type separately to TIF_SVE")

* Several restoration functions use fpsimd_flush_task_state() to discard
  the live FPSIMD/SVE/SME while the in-memory copy is stale.

  When a subset of the FPSIMD/SVE/SME state is restored, the remainder
  may be non-deterministically reset to a stale snapshot from some
  arbitrary point in the past.

  This non-deterministic discarding was introduced in commit:

    8cd969d28f ("arm64/sve: Signal handling support")

  As of that commit, when TIF_SVE was initially clear, failure to
  restore the SVE signal frame could reset the FPSIMD registers to a
  stale snapshot.

  The pattern of discarding unsaved state was subsequently copied into
  restoration functions for some new state in commits:

    39782210eb ("arm64/sme: Implement ZA signal handling")
    ee072cf708 ("arm64/sme: Implement signal handling for ZT")

* On systems with SME/SME2, the entire FPSIMD/SVE/SME state may be
  loaded onto the CPU redundantly. Either restore_fpsimd_context() or
  restore_sve_fpsimd_context() will load the entire FPSIMD/SVE/SME state
  via fpsimd_update_current_state() before restore_za_context() and
  restore_zt_context() each discard the state via
  fpsimd_flush_task_state().

  This is purely redundant work, and not a functional bug.

To fix these issues, rework the native signal handling code to always
save+flush the current task's FPSIMD/SVE/SME state before manipulating
that state. This avoids races with preemption and ensures that state is
manipulated consistently regardless of whether it happened to be live
prior to manipulation. This largely involes:

* Using fpsimd_save_and_flush_current_state() to save+flush the state
  for both signal delivery and signal return, before the state is
  manipulated in any way.

* Removing fpsimd_signal_preserve_current_state() and updating
  preserve_fpsimd_context() to explicitly ensure that the FPSIMD state
  is up-to-date, as preserve_fpsimd_context() is the only consumer of
  the FPSIMD state during signal delivery.

* Modifying fpsimd_update_current_state() to not reload the FPSIMD state
  onto the CPU. Ideally we'd remove fpsimd_update_current_state()
  entirely, but I've left that for subsequent patches as there are a
  number of of other problems with the FPSIMD<->SVE conversion helpers
  that should be addressed at the same time. For now I've removed the
  misleading comment.

For setup_return(), we need to decide (for ABI reasons) whether signal
delivery should have all the side-effects of an SMSTOP. For now I've
left a TODO comment, as there are other questions in this area that I'll
address with subsequent patches.

Fixes: 8c46def444 ("arm64/signal: Add FPMR signal handling")
Fixes: 40a8e87bb3 ("arm64/sme: Disable ZA and streaming mode when handling signals")
Fixes: ea64baacbc ("arm64/signal: Flush FPSIMD register state when disabling streaming mode")
Fixes: baa8515281 ("arm64/fpsimd: Track the saved FPSIMD state type separately to TIF_SVE")
Fixes: 8cd969d28f ("arm64/sve: Signal handling support")
Fixes: 39782210eb ("arm64/sme: Implement ZA signal handling")
Fixes: ee072cf708 ("arm64/sme: Implement signal handling for ZT")
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Will Deacon <will@kernel.org>
Reviewed-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20250409164010.3480271-13-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2025-04-09 18:06:31 +01:00
Mark Rutland
3aa4d74438 arm64/fpsimd: signal32: Always save+flush state early
There are several issues with the way the native signal handling code
manipulates FPSIMD/SVE/SME state. To fix those issues, subsequent
patches will rework the native signal handling code to always save+flush
the current task's FPSIMD/SVE/SME state before manipulating that state.

In preparation for those changes, rework the compat signal handling code
to save+flush the current task's FPSIMD state before manipulating it.

Subsequent patches will remove fpsimd_signal_preserve_current_state()
and fpsimd_update_current_state(). Compat tasks can only have FPSIMD
state, and cannot have any SVE or SME state. Thus, the SVE state
manipulation present in fpsimd_signal_preserve_current_state() and
fpsimd_update_current_state() is not necessary, and it is safe to
directly manipulate current->thread.uw.fpsimd_state once it has been
saved+flushed.

Use fpsimd_save_and_flush_current_state() to save+flush the state for
both signal delivery and signal return, before the state is manipulated
in any way. While it would be safe for compat_restore_vfp_context() to
use fpsimd_flush_task_state(current), there are several extant issues in
the native signal code resulting from incorrect use of
fpsimd_flush_task_state(), and for consistency it is preferable to use
fpsimd_save_and_flush_current_state().

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Will Deacon <will@kernel.org>
Reviewed-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20250409164010.3480271-12-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2025-04-09 18:06:31 +01:00
Mark Rutland
d3a181588d arm64/fpsimd: Add fpsimd_save_and_flush_current_state()
When the current task's FPSIMD/SVE/SME state may be live on *any* CPU in
the system, special care must be taken when manipulating that state, as
this manipulation can race with preemption and/or asynchronous usage of
FPSIMD/SVE/SME (e.g. kernel-mode NEON in softirq handlers).

Even when manipulation is is protected with get_cpu_fpsimd_context() and
get_cpu_fpsimd_context(), the logic necessary when the state is live on
the current CPU can be wildly different from the logic necessary when
the state is not live on the current CPU. A number of historical and
extant issues result from failing to handle these cases consistetntly
and/or correctly.

To make it easier to get such manipulation correct, add a new
fpsimd_save_and_flush_current_state() helper function, which ensures
that the current task's state has been saved to memory and any stale
state on any CPU has been "flushed" such that is not live on any CPU in
the system. This will allow code to safely manipulate the saved state
without risk of races.

Subsequent patches will use the new function.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Will Deacon <will@kernel.org>
Reviewed-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20250409164010.3480271-11-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2025-04-09 18:06:31 +01:00
Mark Rutland
c94f2f3261 arm64/fpsimd: Fix merging of FPSIMD state during signal return
For backwards compatibility reasons, when a signal return occurs which
restores SVE state, the effective lower 128 bits of each of the SVE
vector registers are restored from the corresponding FPSIMD vector
register in the FPSIMD signal frame, overriding the values in the SVE
signal frame. This is intended to be the case regardless of streaming
mode.

To make this happen, restore_sve_fpsimd_context() uses
fpsimd_update_current_state() to merge the lower 128 bits from the
FPSIMD signal frame into the SVE register state. Unfortunately,
fpsimd_update_current_state() performs this merging dependent upon
TIF_SVE, which is not always correct for streaming SVE register state:

* When restoring non-streaming SVE register state there is no observable
  problem, as the signal return code configures TIF_SVE and the saved
  fp_type to match before calling fpsimd_update_current_state(), which
  observes either:

  - TIF_SVE set    AND  fp_type == FP_STATE_SVE
  - TIF_SVE clear  AND  fp_type == FP_STATE_FPSIMD

* On systems which have SME but not SVE, TIF_SVE cannot be set. Thus the
  merging will never happen for the streaming SVE register state.

* On systems which have SVE and SME, TIF_SVE can be set and cleared
  independently of PSTATE.SM. Thus the merging may or may not happen for
  streaming SVE register state.

  As TIF_SVE can be cleared non-deterministically during syscalls
  (including at the start of sigreturn()), the merging may occur
  non-deterministically from the perspective of userspace.

This logic has been broken since its introduction in commit:

  85ed24dad2 ("arm64/sme: Implement streaming SVE signal handling")

... at which point both fpsimd_signal_preserve_current_state() and
fpsimd_update_current_state() only checked TIF SVE. When PSTATE.SM==1
and TIF_SVE was clear, signal delivery would place stale FPSIMD state
into the FPSIMD signal frame, and signal return would not merge this
into the restored register state.

Subsequently, signal delivery was fixed as part of commit:

  61da7c8e2a ("arm64/signal: Don't assume that TIF_SVE means we saved SVE state")

... but signal restore was not given a corresponding fix, and when
TIF_SVE was clear, signal restore would still fail to merge the FPSIMD
state into the restored SVE register state. The 'Fixes' tag did not
indicate that this had been broken since its introduction.

Fix this by merging the FPSIMD state dependent upon the saved fp_type,
matching what we (currently) do during signal delivery.

As described above, when backporting this commit, it will also be
necessary to backport commit:

  61da7c8e2a ("arm64/signal: Don't assume that TIF_SVE means we saved SVE state")

... and prior to commit:

  baa8515281 ("arm64/fpsimd: Track the saved FPSIMD state type separately to TIF_SVE")

... it will be necessary for fpsimd_signal_preserve_current_state() and
fpsimd_update_current_state() to consider both TIF_SVE and
thread_sm_enabled(&current->thread), in place of the saved fp_type.

Fixes: 85ed24dad2 ("arm64/sme: Implement streaming SVE signal handling")
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Will Deacon <will@kernel.org>
Reviewed-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20250409164010.3480271-10-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2025-04-09 18:06:31 +01:00
Mark Rutland
a90878f297 arm64/fpsimd: Reset FPMR upon exec()
An exec() is expected to reset all FPSIMD/SVE/SME state, and barring
special handling of the vector lengths, the state is expected to reset
to zero. This reset is handled in fpsimd_flush_thread(), which the core
exec() code calls via flush_thread().

When support was added for FPMR, no logic was added to
fpsimd_flush_thread() to reset the FPMR value, and thus it is
erroneously inherited across an exec().

Add the missing reset of FPMR.

Fixes: 203f2b95a8 ("arm64/fpsimd: Support FEAT_FPMR")
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Will Deacon <will@kernel.org>
Reviewed-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20250409164010.3480271-9-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2025-04-09 18:06:31 +01:00
Mark Rutland
01098d893f arm64/fpsimd: Avoid clobbering kernel FPSIMD state with SMSTOP
On system with SME, a thread's kernel FPSIMD state may be erroneously
clobbered during a context switch immediately after that state is
restored. Systems without SME are unaffected.

If the CPU happens to be in streaming SVE mode before a context switch
to a thread with kernel FPSIMD state, fpsimd_thread_switch() will
restore the kernel FPSIMD state using fpsimd_load_kernel_state() while
the CPU is still in streaming SVE mode. When fpsimd_thread_switch()
subsequently calls fpsimd_flush_cpu_state(), this will execute an
SMSTOP, causing an exit from streaming SVE mode. The exit from
streaming SVE mode will cause the hardware to reset a number of
FPSIMD/SVE/SME registers, clobbering the FPSIMD state.

Fix this by calling fpsimd_flush_cpu_state() before restoring the kernel
FPSIMD state.

Fixes: e92bee9f86 ("arm64/fpsimd: Avoid erroneous elide of user state reload")
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Will Deacon <will@kernel.org>
Reviewed-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20250409164010.3480271-8-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2025-04-09 18:06:31 +01:00
Mark Brown
e5fa85fce0 arm64/fpsimd: Don't corrupt FPMR when streaming mode changes
When the effective value of PSTATE.SM is changed from 0 to 1 or from 1
to 0 by any method, an entry or exit to/from streaming SVE mode is
performed, and hardware automatically resets a number of registers. As
of ARM DDI 0487 L.a, this means:

* All implemented bits of the SVE vector registers are set to zero.

* All implemented bits of the SVE predicate registers are set to zero.

* All implemented bits of FFR are set to zero, if FFR is implemented in
  the new mode.

* FPSR is set to 0x0000_0000_0800_009f.

* FPMR is set to 0, if FPMR is implemented.

Currently task_fpsimd_load() restores FPMR before restoring SVCR (which
is an accessor for PSTATE.{SM,ZA}), and so the restored value of FPMR
may be clobbered if the restored value of PSTATE.SM happens to differ
from the initial value of PSTATE.SM.

Fix this by moving the restore of FPMR later.

Note: this was originally posted as [1].

Fixes: 203f2b95a8 ("arm64/fpsimd: Support FEAT_FPMR")
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/linux-arm-kernel/20241204-arm64-sme-reenable-v2-2-bae87728251d@kernel.org/
[ Rutland: rewrite commit message ]
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20250409164010.3480271-7-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2025-04-09 18:06:30 +01:00
Mark Brown
d3eaab3c70 arm64/fpsimd: Discard stale CPU state when handling SME traps
The logic for handling SME traps manipulates saved FPSIMD/SVE/SME state
incorrectly, and a race with preemption can result in a task having
TIF_SME set and TIF_FOREIGN_FPSTATE clear even though the live CPU state
is stale (e.g. with SME traps enabled). This can result in warnings from
do_sme_acc() where SME traps are not expected while TIF_SME is set:

|        /* With TIF_SME userspace shouldn't generate any traps */
|        if (test_and_set_thread_flag(TIF_SME))
|                WARN_ON(1);

This is very similar to the SVE issue we fixed in commit:

  751ecf6afd ("arm64/sve: Discard stale CPU state when handling SVE traps")

The race can occur when the SME trap handler is preempted before and
after manipulating the saved FPSIMD/SVE/SME state, starting and ending on
the same CPU, e.g.

| void do_sme_acc(unsigned long esr, struct pt_regs *regs)
| {
|         // Trap on CPU 0 with TIF_SME clear, SME traps enabled
|         // task->fpsimd_cpu is 0.
|         // per_cpu_ptr(&fpsimd_last_state, 0) is task.
|
|         ...
|
|         // Preempted; migrated from CPU 0 to CPU 1.
|         // TIF_FOREIGN_FPSTATE is set.
|
|         get_cpu_fpsimd_context();
|
|         /* With TIF_SME userspace shouldn't generate any traps */
|         if (test_and_set_thread_flag(TIF_SME))
|                 WARN_ON(1);
|
|         if (!test_thread_flag(TIF_FOREIGN_FPSTATE)) {
|                 unsigned long vq_minus_one =
|                         sve_vq_from_vl(task_get_sme_vl(current)) - 1;
|                 sme_set_vq(vq_minus_one);
|
|                 fpsimd_bind_task_to_cpu();
|         }
|
|         put_cpu_fpsimd_context();
|
|         // Preempted; migrated from CPU 1 to CPU 0.
|         // task->fpsimd_cpu is still 0
|         // If per_cpu_ptr(&fpsimd_last_state, 0) is still task then:
|         // - Stale HW state is reused (with SME traps enabled)
|         // - TIF_FOREIGN_FPSTATE is cleared
|         // - A return to userspace skips HW state restore
| }

Fix the case where the state is not live and TIF_FOREIGN_FPSTATE is set
by calling fpsimd_flush_task_state() to detach from the saved CPU
state. This ensures that a subsequent context switch will not reuse the
stale CPU state, and will instead set TIF_FOREIGN_FPSTATE, forcing the
new state to be reloaded from memory prior to a return to userspace.

Note: this was originallly posted as [1].

Fixes: 8bd7f91c03 ("arm64/sme: Implement traps and syscall handling for SME")
Reported-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/linux-arm-kernel/20241204-arm64-sme-reenable-v2-1-bae87728251d@kernel.org/
[ Rutland: rewrite commit message ]
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20250409164010.3480271-6-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2025-04-09 18:06:30 +01:00
Mark Rutland
d7649a4a60 arm64/fpsimd: Remove opportunistic freeing of SME state
When a task's SVE vector length (NSVL) is changed, and the task happens
to have SVCR.{SM,ZA}=={0,0}, vec_set_vector_length() opportunistically
frees the task's sme_state and clears TIF_SME.

The opportunistic freeing was added with no rationale in commit:

  d4d5be94a8 ("arm64/fpsimd: Ensure SME storage is allocated after SVE VL changes")

That commit fixed an unrelated problem where the task's sve_state was
freed while it could be used to store streaming mode register state,
where the fix was to re-allocate the task's sve_state.

There is no need to free and/or reallocate the task's sme_state when the
SVE vector length changes, and there is no need to clear TIF_SME. Given
the SME vector length (SVL) doesn't change, the task's sme_state remains
correctly sized.

Remove the unnecessary opportunistic freeing of the task's sme_state
when the task's SVE vector length is changed. The task's sme_state is
still freed when the SME vector length is changed.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Will Deacon <will@kernel.org>
Reviewed-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20250409164010.3480271-5-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2025-04-09 18:06:30 +01:00
Mark Rutland
45fd86986b arm64/fpsimd: Remove redundant SVE trap manipulation
When task_fpsimd_load() loads the saved FPSIMD/SVE/SME state, it
configures EL0 SVE traps by calling sve_user_{enable,disable}(). This is
unnecessary, and this is suspicious/confusing as task_fpsimd_load() does
not configure EL0 SME traps.

All calls to task_fpsimd_load() are followed by a call to
fpsimd_bind_task_to_cpu(), where the latter configures traps for SVE and
SME dependent upon the current values of TIF_SVE and TIF_SME, overriding
any trap configuration performed by task_fpsimd_load().

The calls to sve_user_{enable,disable}() calls in task_fpsimd_load()
have been redundant (though benign) since they were introduced in
commit:

  a0136be443 ("arm64/fpsimd: Load FP state based on recorded data type")

Remove the unnecessary and confusing SVE trap manipulation.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Will Deacon <will@kernel.org>
Reviewed-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20250409164010.3480271-4-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2025-04-09 18:06:30 +01:00
Mark Rutland
61db0e0ba3 arm64/fpsimd: Remove unused fpsimd_force_sync_to_sve()
There have been no users of fpsimd_force_sync_to_sve() since commit:

  bbc6172eef ("arm64/fpsimd: SME no longer requires SVE register state")

Remove fpsimd_force_sync_to_sve().

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20250409164010.3480271-3-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2025-04-09 18:06:30 +01:00
Mark Rutland
95507570fb arm64/fpsimd: Avoid RES0 bits in the SME trap handler
The SME trap handler consumes RES0 bits from the ESR when determining
the reason for the trap, and depends upon those bits reading as zero.
This may break in future when those RES0 bits are allocated a meaning
and stop reading as zero.

For SME traps taken with ESR_ELx.EC == 0b011101, the specific reason for
the trap is indicated by ESR_ELx.ISS.SMTC ("SME Trap Code"). This field
occupies bits [2:0] of ESR_ELx.ISS, and as of ARM DDI 0487 L.a, bits
[24:3] of ESR_ELx.ISS are RES0. ESR_ELx.ISS itself occupies bits [24:0]
of ESR_ELx.

Extract the SMTC field specifically, matching the way we handle ESR_ELx
fields elsewhere, and ensuring that the handler is future-proof.

Fixes: 8bd7f91c03 ("arm64/sme: Implement traps and syscall handling for SME")
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Will Deacon <will@kernel.org>
Reviewed-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20250409164010.3480271-2-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2025-04-09 18:06:30 +01:00
Linus Torvalds
aa18761a44 arm64 fixes:
- Fix max_pfn calculation when hotplugging memory so that it never
    decreases
 
  - Fix dereference of unused source register in the MOPS SET operation
    fault handling
 
  - Fix NULL calling in do_compat_alignment_fixup() when the 32-bit user
    space does an unaligned LDREX/STREX
 
  - Add the HiSilicon HIP09 processor to the Spectre-BHB affected CPUs
 
  - Drop unused code pud accessors (special/mkspecial)
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Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 fixes from Catalin Marinas:

 - Fix max_pfn calculation when hotplugging memory so that it never
   decreases

 - Fix dereference of unused source register in the MOPS SET operation
   fault handling

 - Fix NULL calling in do_compat_alignment_fixup() when the 32-bit user
   space does an unaligned LDREX/STREX

 - Add the HiSilicon HIP09 processor to the Spectre-BHB affected CPUs

 - Drop unused code pud accessors (special/mkspecial)

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: Don't call NULL in do_compat_alignment_fixup()
  arm64: Add support for HIP09 Spectre-BHB mitigation
  arm64: mm: Drop dead code for pud special bit handling
  arm64: mops: Do not dereference src reg for a set operation
  arm64: mm: Correct the update of max_pfn
2025-04-03 12:07:01 -07:00
Jeff Xu
0061b6e162 mseal sysmap: enable arm64
Provide support for CONFIG_MSEAL_SYSTEM_MAPPINGS on arm64, covering the
vdso, vvar, and compat-mode vectors and sigpage mappings.

Production release testing passes on Android and Chrome OS.

Link: https://lkml.kernel.org/r/20250305021711.3867874-5-jeffxu@google.com
Signed-off-by: Jeff Xu <jeffxu@chromium.org>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Reviewed-by: Kees Cook <kees@kernel.org>
Cc: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Cc: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Andrei Vagin <avagin@gmail.com>
Cc: Anna-Maria Behnsen <anna-maria@linutronix.de>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Benjamin Berg <benjamin@sipsolutions.net>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Rientjes <rientjes@google.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Elliot Hughes <enh@google.com>
Cc: Florian Faineli <f.fainelli@gmail.com>
Cc: Greg Ungerer <gerg@kernel.org>
Cc: Guenter Roeck <groeck@chromium.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jann Horn <jannh@google.com>
Cc: Jason A. Donenfeld <jason@zx2c4.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: Jorge Lucangeli Obes <jorgelo@chromium.org>
Cc: Linus Waleij <linus.walleij@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matthew Wilcow (Oracle) <willy@infradead.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Miguel Ojeda <ojeda@kernel.org>
Cc: Mike Rapoport <mike.rapoport@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Pedro Falcato <pedro.falcato@gmail.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Stephen Röttger <sroettger@google.com>
Cc: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-04-01 15:17:15 -07:00
Linus Torvalds
eb0ece1602 - The 6 patch series "Enable strict percpu address space checks" from
Uros Bizjak uses x86 named address space qualifiers to provide
   compile-time checking of percpu area accesses.
 
   This has caused a small amount of fallout - two or three issues were
   reported.  In all cases the calling code was founf to be incorrect.
 
 - The 4 patch series "Some cleanup for memcg" from Chen Ridong
   implements some relatively monir cleanups for the memcontrol code.
 
 - The 17 patch series "mm: fixes for device-exclusive entries (hmm)"
   from David Hildenbrand fixes a boatload of issues which David found then
   using device-exclusive PTE entries when THP is enabled.  More work is
   needed, but this makes thins better - our own HMM selftests now succeed.
 
 - The 2 patch series "mm: zswap: remove z3fold and zbud" from Yosry
   Ahmed remove the z3fold and zbud implementations.  They have been
   deprecated for half a year and nobody has complained.
 
 - The 5 patch series "mm: further simplify VMA merge operation" from
   Lorenzo Stoakes implements numerous simplifications in this area.  No
   runtime effects are anticipated.
 
 - The 4 patch series "mm/madvise: remove redundant mmap_lock operations
   from process_madvise()" from SeongJae Park rationalizes the locking in
   the madvise() implementation.  Performance gains of 20-25% were observed
   in one MADV_DONTNEED microbenchmark.
 
 - The 12 patch series "Tiny cleanup and improvements about SWAP code"
   from Baoquan He contains a number of touchups to issues which Baoquan
   noticed when working on the swap code.
 
 - The 2 patch series "mm: kmemleak: Usability improvements" from Catalin
   Marinas implements a couple of improvements to the kmemleak user-visible
   output.
 
 - The 2 patch series "mm/damon/paddr: fix large folios access and
   schemes handling" from Usama Arif provides a couple of fixes for DAMON's
   handling of large folios.
 
 - The 3 patch series "mm/damon/core: fix wrong and/or useless
   damos_walk() behaviors" from SeongJae Park fixes a few issues with the
   accuracy of kdamond's walking of DAMON regions.
 
 - The 3 patch series "expose mapping wrprotect, fix fb_defio use" from
   Lorenzo Stoakes changes the interaction between framebuffer deferred-io
   and core MM.  No functional changes are anticipated - this is
   preparatory work for the future removal of page structure fields.
 
 - The 4 patch series "mm/damon: add support for hugepage_size DAMOS
   filter" from Usama Arif adds a DAMOS filter which permits the filtering
   by huge page sizes.
 
 - The 4 patch series "mm: permit guard regions for file-backed/shmem
   mappings" from Lorenzo Stoakes extends the guard region feature from its
   present "anon mappings only" state.  The feature now covers shmem and
   file-backed mappings.
 
 - The 4 patch series "mm: batched unmap lazyfree large folios during
   reclamation" from Barry Song cleans up and speeds up the unmapping for
   pte-mapped large folios.
 
 - The 18 patch series "reimplement per-vma lock as a refcount" from
   Suren Baghdasaryan puts the vm_lock back into the vma.  Our reasons for
   pulling it out were largely bogus and that change made the code more
   messy.  This patchset provides small (0-10%) improvements on one
   microbenchmark.
 
 - The 5 patch series "Docs/mm/damon: misc DAMOS filters documentation
   fixes and improves" from SeongJae Park does some maintenance work on the
   DAMON docs.
 
 - The 27 patch series "hugetlb/CMA improvements for large systems" from
   Frank van der Linden addresses a pile of issues which have been observed
   when using CMA on large machines.
 
 - The 2 patch series "mm/damon: introduce DAMOS filter type for unmapped
   pages" from SeongJae Park enables users of DMAON/DAMOS to filter my the
   page's mapped/unmapped status.
 
 - The 19 patch series "zsmalloc/zram: there be preemption" from Sergey
   Senozhatsky teaches zram to run its compression and decompression
   operations preemptibly.
 
 - The 12 patch series "selftests/mm: Some cleanups from trying to run
   them" from Brendan Jackman fixes a pile of unrelated issues which
   Brendan encountered while runnimg our selftests.
 
 - The 2 patch series "fs/proc/task_mmu: add guard region bit to pagemap"
   from Lorenzo Stoakes permits userspace to use /proc/pid/pagemap to
   determine whether a particular page is a guard page.
 
 - The 7 patch series "mm, swap: remove swap slot cache" from Kairui Song
   removes the swap slot cache from the allocation path - it simply wasn't
   being effective.
 
 - The 5 patch series "mm: cleanups for device-exclusive entries (hmm)"
   from David Hildenbrand implements a number of unrelated cleanups in this
   code.
 
 - The 5 patch series "mm: Rework generic PTDUMP configs" from Anshuman
   Khandual implements a number of preparatoty cleanups to the
   GENERIC_PTDUMP Kconfig logic.
 
 - The 8 patch series "mm/damon: auto-tune aggregation interval" from
   SeongJae Park implements a feedback-driven automatic tuning feature for
   DAMON's aggregation interval tuning.
 
 - The 5 patch series "Fix lazy mmu mode" from Ryan Roberts fixes some
   issues in powerpc, sparc and x86 lazy MMU implementations.  Ryan did
   this in preparation for implementing lazy mmu mode for arm64 to optimize
   vmalloc.
 
 - The 2 patch series "mm/page_alloc: Some clarifications for migratetype
   fallback" from Brendan Jackman reworks some commentary to make the code
   easier to follow.
 
 - The 3 patch series "page_counter cleanup and size reduction" from
   Shakeel Butt cleans up the page_counter code and fixes a size increase
   which we accidentally added late last year.
 
 - The 3 patch series "Add a command line option that enables control of
   how many threads should be used to allocate huge pages" from Thomas
   Prescher does that.  It allows the careful operator to significantly
   reduce boot time by tuning the parallalization of huge page
   initialization.
 
 - The 3 patch series "Fix calculations in trace_balance_dirty_pages()
   for cgwb" from Tang Yizhou fixes the tracing output from the dirty page
   balancing code.
 
 - The 9 patch series "mm/damon: make allow filters after reject filters
   useful and intuitive" from SeongJae Park improves the handling of allow
   and reject filters.  Behaviour is made more consistent and the
   documention is updated accordingly.
 
 - The 5 patch series "Switch zswap to object read/write APIs" from Yosry
   Ahmed updates zswap to the new object read/write APIs and thus permits
   the removal of some legacy code from zpool and zsmalloc.
 
 - The 6 patch series "Some trivial cleanups for shmem" from Baolin Wang
   does as it claims.
 
 - The 20 patch series "fs/dax: Fix ZONE_DEVICE page reference counts"
   from Alistair Popple regularizes the weird ZONE_DEVICE page refcount
   handling in DAX, permittig the removal of a number of special-case
   checks.
 
 - The 4 patch series "refactor mremap and fix bug" from Lorenzo Stoakes
   is a preparatoty refactoring and cleanup of the mremap() code.
 
 - The 20 patch series "mm: MM owner tracking for large folios (!hugetlb)
   + CONFIG_NO_PAGE_MAPCOUNT" from David Hildenbrand reworks the manner in
   which we determine whether a large folio is known to be mapped
   exclusively into a single MM.
 
 - The 8 patch series "mm/damon: add sysfs dirs for managing DAMOS
   filters based on handling layers" from SeongJae Park adds a couple of
   new sysfs directories to ease the management of DAMON/DAMOS filters.
 
 - The 13 patch series "arch, mm: reduce code duplication in mem_init()"
   from Mike Rapoport consolidates many per-arch implementations of
   mem_init() into code generic code, where that is practical.
 
 - The 13 patch series "mm/damon/sysfs: commit parameters online via
   damon_call()" from SeongJae Park continues the cleaning up of sysfs
   access to DAMON internal data.
 
 - The 3 patch series "mm: page_ext: Introduce new iteration API" from
   Luiz Capitulino reworks the page_ext initialization to fix a boot-time
   crash which was observed with an unusual combination of compile and
   cmdline options.
 
 - The 8 patch series "Buddy allocator like (or non-uniform) folio split"
   from Zi Yan reworks the code to split a folio into smaller folios.  The
   main benefit is lessened memory consumption: fewer post-split folios are
   generated.
 
 - The 2 patch series "Minimize xa_node allocation during xarry split"
   from Zi Yan reduces the number of xarray xa_nodes which are generated
   during an xarray split.
 
 - The 2 patch series "drivers/base/memory: Two cleanups" from Gavin Shan
   performs some maintenance work on the drivers/base/memory code.
 
 - The 3 patch series "Add tracepoints for lowmem reserves, watermarks
   and totalreserve_pages" from Martin Liu adds some more tracepoints to
   the page allocator code.
 
 - The 4 patch series "mm/madvise: cleanup requests validations and
   classifications" from SeongJae Park cleans up some warts which SeongJae
   observed during his earlier madvise work.
 
 - The 3 patch series "mm/hwpoison: Fix regressions in memory failure
   handling" from Shuai Xue addresses two quite serious regressions which
   Shuai has observed in the memory-failure implementation.
 
 - The 5 patch series "mm: reliable huge page allocator" from Johannes
   Weiner makes huge page allocations cheaper and more reliable by reducing
   fragmentation.
 
 - The 5 patch series "Minor memcg cleanups & prep for memdescs" from
   Matthew Wilcox is preparatory work for the future implementation of
   memdescs.
 
 - The 4 patch series "track memory used by balloon drivers" from Nico
   Pache introduces a way to track memory used by our various balloon
   drivers.
 
 - The 2 patch series "mm/damon: introduce DAMOS filter type for active
   pages" from Nhat Pham permits users to filter for active/inactive pages,
   separately for file and anon pages.
 
 - The 2 patch series "Adding Proactive Memory Reclaim Statistics" from
   Hao Jia separates the proactive reclaim statistics from the direct
   reclaim statistics.
 
 - The 2 patch series "mm/vmscan: don't try to reclaim hwpoison folio"
   from Jinjiang Tu fixes our handling of hwpoisoned pages within the
   reclaim code.
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Merge tag 'mm-stable-2025-03-30-16-52' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:

 - The series "Enable strict percpu address space checks" from Uros
   Bizjak uses x86 named address space qualifiers to provide
   compile-time checking of percpu area accesses.

   This has caused a small amount of fallout - two or three issues were
   reported. In all cases the calling code was found to be incorrect.

 - The series "Some cleanup for memcg" from Chen Ridong implements some
   relatively monir cleanups for the memcontrol code.

 - The series "mm: fixes for device-exclusive entries (hmm)" from David
   Hildenbrand fixes a boatload of issues which David found then using
   device-exclusive PTE entries when THP is enabled. More work is
   needed, but this makes thins better - our own HMM selftests now
   succeed.

 - The series "mm: zswap: remove z3fold and zbud" from Yosry Ahmed
   remove the z3fold and zbud implementations. They have been deprecated
   for half a year and nobody has complained.

 - The series "mm: further simplify VMA merge operation" from Lorenzo
   Stoakes implements numerous simplifications in this area. No runtime
   effects are anticipated.

 - The series "mm/madvise: remove redundant mmap_lock operations from
   process_madvise()" from SeongJae Park rationalizes the locking in the
   madvise() implementation. Performance gains of 20-25% were observed
   in one MADV_DONTNEED microbenchmark.

 - The series "Tiny cleanup and improvements about SWAP code" from
   Baoquan He contains a number of touchups to issues which Baoquan
   noticed when working on the swap code.

 - The series "mm: kmemleak: Usability improvements" from Catalin
   Marinas implements a couple of improvements to the kmemleak
   user-visible output.

 - The series "mm/damon/paddr: fix large folios access and schemes
   handling" from Usama Arif provides a couple of fixes for DAMON's
   handling of large folios.

 - The series "mm/damon/core: fix wrong and/or useless damos_walk()
   behaviors" from SeongJae Park fixes a few issues with the accuracy of
   kdamond's walking of DAMON regions.

 - The series "expose mapping wrprotect, fix fb_defio use" from Lorenzo
   Stoakes changes the interaction between framebuffer deferred-io and
   core MM. No functional changes are anticipated - this is preparatory
   work for the future removal of page structure fields.

 - The series "mm/damon: add support for hugepage_size DAMOS filter"
   from Usama Arif adds a DAMOS filter which permits the filtering by
   huge page sizes.

 - The series "mm: permit guard regions for file-backed/shmem mappings"
   from Lorenzo Stoakes extends the guard region feature from its
   present "anon mappings only" state. The feature now covers shmem and
   file-backed mappings.

 - The series "mm: batched unmap lazyfree large folios during
   reclamation" from Barry Song cleans up and speeds up the unmapping
   for pte-mapped large folios.

 - The series "reimplement per-vma lock as a refcount" from Suren
   Baghdasaryan puts the vm_lock back into the vma. Our reasons for
   pulling it out were largely bogus and that change made the code more
   messy. This patchset provides small (0-10%) improvements on one
   microbenchmark.

 - The series "Docs/mm/damon: misc DAMOS filters documentation fixes and
   improves" from SeongJae Park does some maintenance work on the DAMON
   docs.

 - The series "hugetlb/CMA improvements for large systems" from Frank
   van der Linden addresses a pile of issues which have been observed
   when using CMA on large machines.

 - The series "mm/damon: introduce DAMOS filter type for unmapped pages"
   from SeongJae Park enables users of DMAON/DAMOS to filter my the
   page's mapped/unmapped status.

 - The series "zsmalloc/zram: there be preemption" from Sergey
   Senozhatsky teaches zram to run its compression and decompression
   operations preemptibly.

 - The series "selftests/mm: Some cleanups from trying to run them" from
   Brendan Jackman fixes a pile of unrelated issues which Brendan
   encountered while runnimg our selftests.

 - The series "fs/proc/task_mmu: add guard region bit to pagemap" from
   Lorenzo Stoakes permits userspace to use /proc/pid/pagemap to
   determine whether a particular page is a guard page.

 - The series "mm, swap: remove swap slot cache" from Kairui Song
   removes the swap slot cache from the allocation path - it simply
   wasn't being effective.

 - The series "mm: cleanups for device-exclusive entries (hmm)" from
   David Hildenbrand implements a number of unrelated cleanups in this
   code.

 - The series "mm: Rework generic PTDUMP configs" from Anshuman Khandual
   implements a number of preparatoty cleanups to the GENERIC_PTDUMP
   Kconfig logic.

 - The series "mm/damon: auto-tune aggregation interval" from SeongJae
   Park implements a feedback-driven automatic tuning feature for
   DAMON's aggregation interval tuning.

 - The series "Fix lazy mmu mode" from Ryan Roberts fixes some issues in
   powerpc, sparc and x86 lazy MMU implementations. Ryan did this in
   preparation for implementing lazy mmu mode for arm64 to optimize
   vmalloc.

 - The series "mm/page_alloc: Some clarifications for migratetype
   fallback" from Brendan Jackman reworks some commentary to make the
   code easier to follow.

 - The series "page_counter cleanup and size reduction" from Shakeel
   Butt cleans up the page_counter code and fixes a size increase which
   we accidentally added late last year.

 - The series "Add a command line option that enables control of how
   many threads should be used to allocate huge pages" from Thomas
   Prescher does that. It allows the careful operator to significantly
   reduce boot time by tuning the parallalization of huge page
   initialization.

 - The series "Fix calculations in trace_balance_dirty_pages() for cgwb"
   from Tang Yizhou fixes the tracing output from the dirty page
   balancing code.

 - The series "mm/damon: make allow filters after reject filters useful
   and intuitive" from SeongJae Park improves the handling of allow and
   reject filters. Behaviour is made more consistent and the documention
   is updated accordingly.

 - The series "Switch zswap to object read/write APIs" from Yosry Ahmed
   updates zswap to the new object read/write APIs and thus permits the
   removal of some legacy code from zpool and zsmalloc.

 - The series "Some trivial cleanups for shmem" from Baolin Wang does as
   it claims.

 - The series "fs/dax: Fix ZONE_DEVICE page reference counts" from
   Alistair Popple regularizes the weird ZONE_DEVICE page refcount
   handling in DAX, permittig the removal of a number of special-case
   checks.

 - The series "refactor mremap and fix bug" from Lorenzo Stoakes is a
   preparatoty refactoring and cleanup of the mremap() code.

 - The series "mm: MM owner tracking for large folios (!hugetlb) +
   CONFIG_NO_PAGE_MAPCOUNT" from David Hildenbrand reworks the manner in
   which we determine whether a large folio is known to be mapped
   exclusively into a single MM.

 - The series "mm/damon: add sysfs dirs for managing DAMOS filters based
   on handling layers" from SeongJae Park adds a couple of new sysfs
   directories to ease the management of DAMON/DAMOS filters.

 - The series "arch, mm: reduce code duplication in mem_init()" from
   Mike Rapoport consolidates many per-arch implementations of
   mem_init() into code generic code, where that is practical.

 - The series "mm/damon/sysfs: commit parameters online via
   damon_call()" from SeongJae Park continues the cleaning up of sysfs
   access to DAMON internal data.

 - The series "mm: page_ext: Introduce new iteration API" from Luiz
   Capitulino reworks the page_ext initialization to fix a boot-time
   crash which was observed with an unusual combination of compile and
   cmdline options.

 - The series "Buddy allocator like (or non-uniform) folio split" from
   Zi Yan reworks the code to split a folio into smaller folios. The
   main benefit is lessened memory consumption: fewer post-split folios
   are generated.

 - The series "Minimize xa_node allocation during xarry split" from Zi
   Yan reduces the number of xarray xa_nodes which are generated during
   an xarray split.

 - The series "drivers/base/memory: Two cleanups" from Gavin Shan
   performs some maintenance work on the drivers/base/memory code.

 - The series "Add tracepoints for lowmem reserves, watermarks and
   totalreserve_pages" from Martin Liu adds some more tracepoints to the
   page allocator code.

 - The series "mm/madvise: cleanup requests validations and
   classifications" from SeongJae Park cleans up some warts which
   SeongJae observed during his earlier madvise work.

 - The series "mm/hwpoison: Fix regressions in memory failure handling"
   from Shuai Xue addresses two quite serious regressions which Shuai
   has observed in the memory-failure implementation.

 - The series "mm: reliable huge page allocator" from Johannes Weiner
   makes huge page allocations cheaper and more reliable by reducing
   fragmentation.

 - The series "Minor memcg cleanups & prep for memdescs" from Matthew
   Wilcox is preparatory work for the future implementation of memdescs.

 - The series "track memory used by balloon drivers" from Nico Pache
   introduces a way to track memory used by our various balloon drivers.

 - The series "mm/damon: introduce DAMOS filter type for active pages"
   from Nhat Pham permits users to filter for active/inactive pages,
   separately for file and anon pages.

 - The series "Adding Proactive Memory Reclaim Statistics" from Hao Jia
   separates the proactive reclaim statistics from the direct reclaim
   statistics.

 - The series "mm/vmscan: don't try to reclaim hwpoison folio" from
   Jinjiang Tu fixes our handling of hwpoisoned pages within the reclaim
   code.

* tag 'mm-stable-2025-03-30-16-52' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (431 commits)
  mm/page_alloc: remove unnecessary __maybe_unused in order_to_pindex()
  x86/mm: restore early initialization of high_memory for 32-bits
  mm/vmscan: don't try to reclaim hwpoison folio
  mm/hwpoison: introduce folio_contain_hwpoisoned_page() helper
  cgroup: docs: add pswpin and pswpout items in cgroup v2 doc
  mm: vmscan: split proactive reclaim statistics from direct reclaim statistics
  selftests/mm: speed up split_huge_page_test
  selftests/mm: uffd-unit-tests support for hugepages > 2M
  docs/mm/damon/design: document active DAMOS filter type
  mm/damon: implement a new DAMOS filter type for active pages
  fs/dax: don't disassociate zero page entries
  MM documentation: add "Unaccepted" meminfo entry
  selftests/mm: add commentary about 9pfs bugs
  fork: use __vmalloc_node() for stack allocation
  docs/mm: Physical Memory: Populate the "Zones" section
  xen: balloon: update the NR_BALLOON_PAGES state
  hv_balloon: update the NR_BALLOON_PAGES state
  balloon_compaction: update the NR_BALLOON_PAGES state
  meminfo: add a per node counter for balloon drivers
  mm: remove references to folio in __memcg_kmem_uncharge_page()
  ...
2025-04-01 09:29:18 -07:00
Angelos Oikonomopoulos
c28f31deea arm64: Don't call NULL in do_compat_alignment_fixup()
do_alignment_t32_to_handler() only fixes up alignment faults for
specific instructions; it returns NULL otherwise (e.g. LDREX). When
that's the case, signal to the caller that it needs to proceed with the
regular alignment fault handling (i.e. SIGBUS). Without this patch, the
kernel panics:

  Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000
  Mem abort info:
    ESR = 0x0000000086000006
    EC = 0x21: IABT (current EL), IL = 32 bits
    SET = 0, FnV = 0
    EA = 0, S1PTW = 0
    FSC = 0x06: level 2 translation fault
  user pgtable: 4k pages, 48-bit VAs, pgdp=00000800164aa000
  [0000000000000000] pgd=0800081fdbd22003, p4d=0800081fdbd22003, pud=08000815d51c6003, pmd=0000000000000000
  Internal error: Oops: 0000000086000006 [#1] SMP
  Modules linked in: cfg80211 rfkill xt_nat xt_tcpudp xt_conntrack nft_chain_nat xt_MASQUERADE nf_nat nf_conntrack_netlink nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 xfrm_user xfrm_algo xt_addrtype nft_compat br_netfilter veth nvme_fa>
   libcrc32c crc32c_generic raid0 multipath linear dm_mod dax raid1 md_mod xhci_pci nvme xhci_hcd nvme_core t10_pi usbcore igb crc64_rocksoft crc64 crc_t10dif crct10dif_generic crct10dif_ce crct10dif_common usb_common i2c_algo_bit i2c>
  CPU: 2 PID: 3932954 Comm: WPEWebProcess Not tainted 6.1.0-31-arm64 #1  Debian 6.1.128-1
  Hardware name: GIGABYTE MP32-AR1-00/MP32-AR1-00, BIOS F18v (SCP: 1.08.20211002) 12/01/2021
  pstate: 80400009 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
  pc : 0x0
  lr : do_compat_alignment_fixup+0xd8/0x3dc
  sp : ffff80000f973dd0
  x29: ffff80000f973dd0 x28: ffff081b42526180 x27: 0000000000000000
  x26: 0000000000000000 x25: 0000000000000000 x24: 0000000000000000
  x23: 0000000000000004 x22: 0000000000000000 x21: 0000000000000001
  x20: 00000000e8551f00 x19: ffff80000f973eb0 x18: 0000000000000000
  x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000
  x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000000
  x11: 0000000000000000 x10: 0000000000000000 x9 : ffffaebc949bc488
  x8 : 0000000000000000 x7 : 0000000000000000 x6 : 0000000000000000
  x5 : 0000000000400000 x4 : 0000fffffffffffe x3 : 0000000000000000
  x2 : ffff80000f973eb0 x1 : 00000000e8551f00 x0 : 0000000000000001
  Call trace:
   0x0
   do_alignment_fault+0x40/0x50
   do_mem_abort+0x4c/0xa0
   el0_da+0x48/0xf0
   el0t_32_sync_handler+0x110/0x140
   el0t_32_sync+0x190/0x194
  Code: bad PC value
  ---[ end trace 0000000000000000 ]---

Signed-off-by: Angelos Oikonomopoulos <angelos@igalia.com>
Fixes: 3fc24ef32d ("arm64: compat: Implement misalignment fixups for multiword loads")
Cc: <stable@vger.kernel.org> # 6.1.x
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Link: https://lore.kernel.org/r/20250401085150.148313-1-angelos@igalia.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2025-04-01 14:13:11 +01:00
Linus Torvalds
01d5b167dc Modules changes for 6.15-rc1
- Use RCU instead of RCU-sched
 
   The mix of rcu_read_lock(), rcu_read_lock_sched() and preempt_disable()
   in the module code and its users has been replaced with just
   rcu_read_lock().
 
 - The rest of changes are smaller fixes and updates.
 
 The changes have been on linux-next for at least 2 weeks, with the RCU
 cleanup present for 2 months. One performance problem was reported with the
 RCU change when KASAN + lockdep were enabled, but it was effectively
 addressed by the already merged ee57ab5a32 ("locking/lockdep: Disable
 KASAN instrumentation of lockdep.c").
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Merge tag 'modules-6.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/modules/linux

Pull modules updates from Petr Pavlu:

 - Use RCU instead of RCU-sched

   The mix of rcu_read_lock(), rcu_read_lock_sched() and
   preempt_disable() in the module code and its users has
   been replaced with just rcu_read_lock()

 - The rest of changes are smaller fixes and updates

* tag 'modules-6.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/modules/linux: (32 commits)
  MAINTAINERS: Update the MODULE SUPPORT section
  module: Remove unnecessary size argument when calling strscpy()
  module: Replace deprecated strncpy() with strscpy()
  params: Annotate struct module_param_attrs with __counted_by()
  bug: Use RCU instead RCU-sched to protect module_bug_list.
  static_call: Use RCU in all users of __module_text_address().
  kprobes: Use RCU in all users of __module_text_address().
  bpf: Use RCU in all users of __module_text_address().
  jump_label: Use RCU in all users of __module_text_address().
  jump_label: Use RCU in all users of __module_address().
  x86: Use RCU in all users of __module_address().
  cfi: Use RCU while invoking __module_address().
  powerpc/ftrace: Use RCU in all users of __module_text_address().
  LoongArch: ftrace: Use RCU in all users of __module_text_address().
  LoongArch/orc: Use RCU in all users of __module_address().
  arm64: module: Use RCU in all users of __module_text_address().
  ARM: module: Use RCU in all users of __module_text_address().
  module: Use RCU in all users of __module_text_address().
  module: Use RCU in all users of __module_address().
  module: Use RCU in search_module_extables().
  ...
2025-03-30 15:44:36 -07:00
Jinqian Yang
e18c09b204 arm64: Add support for HIP09 Spectre-BHB mitigation
The HIP09 processor is vulnerable to the Spectre-BHB (Branch History
Buffer) attack, which can be exploited to leak information through
branch prediction side channels. This commit adds the MIDR of HIP09
to the list for software mitigation.

Signed-off-by: Jinqian Yang <yangjinqian1@huawei.com>
Link: https://lore.kernel.org/r/20250325141900.2057314-1-yangjinqian1@huawei.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2025-03-28 19:26:29 +00:00
Linus Torvalds
edb0e8f6e2 ARM:
* Nested virtualization support for VGICv3, giving the nested
 hypervisor control of the VGIC hardware when running an L2 VM
 
 * Removal of 'late' nested virtualization feature register masking,
   making the supported feature set directly visible to userspace
 
 * Support for emulating FEAT_PMUv3 on Apple silicon, taking advantage
   of an IMPLEMENTATION DEFINED trap that covers all PMUv3 registers
 
 * Paravirtual interface for discovering the set of CPU implementations
   where a VM may run, addressing a longstanding issue of guest CPU
   errata awareness in big-little systems and cross-implementation VM
   migration
 
 * Userspace control of the registers responsible for identifying a
   particular CPU implementation (MIDR_EL1, REVIDR_EL1, AIDR_EL1),
   allowing VMs to be migrated cross-implementation
 
 * pKVM updates, including support for tracking stage-2 page table
   allocations in the protected hypervisor in the 'SecPageTable' stat
 
 * Fixes to vPMU, ensuring that userspace updates to the vPMU after
   KVM_RUN are reflected into the backing perf events
 
 LoongArch:
 
 * Remove unnecessary header include path
 
 * Assume constant PGD during VM context switch
 
 * Add perf events support for guest VM
 
 RISC-V:
 
 * Disable the kernel perf counter during configure
 
 * KVM selftests improvements for PMU
 
 * Fix warning at the time of KVM module removal
 
 x86:
 
 * Add support for aging of SPTEs without holding mmu_lock.  Not taking mmu_lock
   allows multiple aging actions to run in parallel, and more importantly avoids
   stalling vCPUs.  This includes an implementation of per-rmap-entry locking;
   aging the gfn is done with only a per-rmap single-bin spinlock taken, whereas
   locking an rmap for write requires taking both the per-rmap spinlock and
   the mmu_lock.
 
   Note that this decreases slightly the accuracy of accessed-page information,
   because changes to the SPTE outside aging might not use atomic operations
   even if they could race against a clear of the Accessed bit.  This is
   deliberate because KVM and mm/ tolerate false positives/negatives for
   accessed information, and testing has shown that reducing the latency of
   aging is far more beneficial to overall system performance than providing
   "perfect" young/old information.
 
 * Defer runtime CPUID updates until KVM emulates a CPUID instruction, to
   coalesce updates when multiple pieces of vCPU state are changing, e.g. as
   part of a nested transition.
 
 * Fix a variety of nested emulation bugs, and add VMX support for synthesizing
   nested VM-Exit on interception (instead of injecting #UD into L2).
 
 * Drop "support" for async page faults for protected guests that do not set
   SEND_ALWAYS (i.e. that only want async page faults at CPL3)
 
 * Bring a bit of sanity to x86's VM teardown code, which has accumulated
   a lot of cruft over the years.  Particularly, destroy vCPUs before
   the MMU, despite the latter being a VM-wide operation.
 
 * Add common secure TSC infrastructure for use within SNP and in the
   future TDX
 
 * Block KVM_CAP_SYNC_REGS if guest state is protected.  It does not make
   sense to use the capability if the relevant registers are not
   available for reading or writing.
 
 * Don't take kvm->lock when iterating over vCPUs in the suspend notifier to
   fix a largely theoretical deadlock.
 
 * Use the vCPU's actual Xen PV clock information when starting the Xen timer,
   as the cached state in arch.hv_clock can be stale/bogus.
 
 * Fix a bug where KVM could bleed PVCLOCK_GUEST_STOPPED across different
   PV clocks; restrict PVCLOCK_GUEST_STOPPED to kvmclock, as KVM's suspend
   notifier only accounts for kvmclock, and there's no evidence that the
   flag is actually supported by Xen guests.
 
 * Clean up the per-vCPU "cache" of its reference pvclock, and instead only
   track the vCPU's TSC scaling (multipler+shift) metadata (which is moderately
   expensive to compute, and rarely changes for modern setups).
 
 * Don't write to the Xen hypercall page on MSR writes that are initiated by
   the host (userspace or KVM) to fix a class of bugs where KVM can write to
   guest memory at unexpected times, e.g. during vCPU creation if userspace has
   set the Xen hypercall MSR index to collide with an MSR that KVM emulates.
 
 * Restrict the Xen hypercall MSR index to the unofficial synthetic range to
   reduce the set of possible collisions with MSRs that are emulated by KVM
   (collisions can still happen as KVM emulates Hyper-V MSRs, which also reside
   in the synthetic range).
 
 * Clean up and optimize KVM's handling of Xen MSR writes and xen_hvm_config.
 
 * Update Xen TSC leaves during CPUID emulation instead of modifying the CPUID
   entries when updating PV clocks; there is no guarantee PV clocks will be
   updated between TSC frequency changes and CPUID emulation, and guest reads
   of the TSC leaves should be rare, i.e. are not a hot path.
 
 x86 (Intel):
 
 * Fix a bug where KVM unnecessarily reads XFD_ERR from hardware and thus
   modifies the vCPU's XFD_ERR on a #NM due to CR0.TS=1.
 
 * Pass XFD_ERR as the payload when injecting #NM, as a preparatory step
   for upcoming FRED virtualization support.
 
 * Decouple the EPT entry RWX protection bit macros from the EPT Violation
   bits, both as a general cleanup and in anticipation of adding support for
   emulating Mode-Based Execution Control (MBEC).
 
 * Reject KVM_RUN if userspace manages to gain control and stuff invalid guest
   state while KVM is in the middle of emulating nested VM-Enter.
 
 * Add a macro to handle KVM's sanity checks on entry/exit VMCS control pairs
   in anticipation of adding sanity checks for secondary exit controls (the
   primary field is out of bits).
 
 x86 (AMD):
 
 * Ensure the PSP driver is initialized when both the PSP and KVM modules are
   built-in (the initcall framework doesn't handle dependencies).
 
 * Use long-term pins when registering encrypted memory regions, so that the
   pages are migrated out of MIGRATE_CMA/ZONE_MOVABLE and don't lead to
   excessive fragmentation.
 
 * Add macros and helpers for setting GHCB return/error codes.
 
 * Add support for Idle HLT interception, which elides interception if the vCPU
   has a pending, unmasked virtual IRQ when HLT is executed.
 
 * Fix a bug in INVPCID emulation where KVM fails to check for a non-canonical
   address.
 
 * Don't attempt VMRUN for SEV-ES+ guests if the vCPU's VMSA is invalid, e.g.
   because the vCPU was "destroyed" via SNP's AP Creation hypercall.
 
 * Reject SNP AP Creation if the requested SEV features for the vCPU don't
   match the VM's configured set of features.
 
 Selftests:
 
 * Fix again the Intel PMU counters test; add a data load and do CLFLUSH{OPT} on the data
   instead of executing code.  The theory is that modern Intel CPUs have
   learned new code prefetching tricks that bypass the PMU counters.
 
 * Fix a flaw in the Intel PMU counters test where it asserts that an event is
   counting correctly without actually knowing what the event counts on the
   underlying hardware.
 
 * Fix a variety of flaws, bugs, and false failures/passes dirty_log_test, and
   improve its coverage by collecting all dirty entries on each iteration.
 
 * Fix a few minor bugs related to handling of stats FDs.
 
 * Add infrastructure to make vCPU and VM stats FDs available to tests by
   default (open the FDs during VM/vCPU creation).
 
 * Relax an assertion on the number of HLT exits in the xAPIC IPI test when
   running on a CPU that supports AMD's Idle HLT (which elides interception of
   HLT if a virtual IRQ is pending and unmasked).
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull kvm updates from Paolo Bonzini:
 "ARM:

   - Nested virtualization support for VGICv3, giving the nested
     hypervisor control of the VGIC hardware when running an L2 VM

   - Removal of 'late' nested virtualization feature register masking,
     making the supported feature set directly visible to userspace

   - Support for emulating FEAT_PMUv3 on Apple silicon, taking advantage
     of an IMPLEMENTATION DEFINED trap that covers all PMUv3 registers

   - Paravirtual interface for discovering the set of CPU
     implementations where a VM may run, addressing a longstanding issue
     of guest CPU errata awareness in big-little systems and
     cross-implementation VM migration

   - Userspace control of the registers responsible for identifying a
     particular CPU implementation (MIDR_EL1, REVIDR_EL1, AIDR_EL1),
     allowing VMs to be migrated cross-implementation

   - pKVM updates, including support for tracking stage-2 page table
     allocations in the protected hypervisor in the 'SecPageTable' stat

   - Fixes to vPMU, ensuring that userspace updates to the vPMU after
     KVM_RUN are reflected into the backing perf events

  LoongArch:

   - Remove unnecessary header include path

   - Assume constant PGD during VM context switch

   - Add perf events support for guest VM

  RISC-V:

   - Disable the kernel perf counter during configure

   - KVM selftests improvements for PMU

   - Fix warning at the time of KVM module removal

  x86:

   - Add support for aging of SPTEs without holding mmu_lock.

     Not taking mmu_lock allows multiple aging actions to run in
     parallel, and more importantly avoids stalling vCPUs. This includes
     an implementation of per-rmap-entry locking; aging the gfn is done
     with only a per-rmap single-bin spinlock taken, whereas locking an
     rmap for write requires taking both the per-rmap spinlock and the
     mmu_lock.

     Note that this decreases slightly the accuracy of accessed-page
     information, because changes to the SPTE outside aging might not
     use atomic operations even if they could race against a clear of
     the Accessed bit.

     This is deliberate because KVM and mm/ tolerate false
     positives/negatives for accessed information, and testing has shown
     that reducing the latency of aging is far more beneficial to
     overall system performance than providing "perfect" young/old
     information.

   - Defer runtime CPUID updates until KVM emulates a CPUID instruction,
     to coalesce updates when multiple pieces of vCPU state are
     changing, e.g. as part of a nested transition

   - Fix a variety of nested emulation bugs, and add VMX support for
     synthesizing nested VM-Exit on interception (instead of injecting
     #UD into L2)

   - Drop "support" for async page faults for protected guests that do
     not set SEND_ALWAYS (i.e. that only want async page faults at CPL3)

   - Bring a bit of sanity to x86's VM teardown code, which has
     accumulated a lot of cruft over the years. Particularly, destroy
     vCPUs before the MMU, despite the latter being a VM-wide operation

   - Add common secure TSC infrastructure for use within SNP and in the
     future TDX

   - Block KVM_CAP_SYNC_REGS if guest state is protected. It does not
     make sense to use the capability if the relevant registers are not
     available for reading or writing

   - Don't take kvm->lock when iterating over vCPUs in the suspend
     notifier to fix a largely theoretical deadlock

   - Use the vCPU's actual Xen PV clock information when starting the
     Xen timer, as the cached state in arch.hv_clock can be stale/bogus

   - Fix a bug where KVM could bleed PVCLOCK_GUEST_STOPPED across
     different PV clocks; restrict PVCLOCK_GUEST_STOPPED to kvmclock, as
     KVM's suspend notifier only accounts for kvmclock, and there's no
     evidence that the flag is actually supported by Xen guests

   - Clean up the per-vCPU "cache" of its reference pvclock, and instead
     only track the vCPU's TSC scaling (multipler+shift) metadata (which
     is moderately expensive to compute, and rarely changes for modern
     setups)

   - Don't write to the Xen hypercall page on MSR writes that are
     initiated by the host (userspace or KVM) to fix a class of bugs
     where KVM can write to guest memory at unexpected times, e.g.
     during vCPU creation if userspace has set the Xen hypercall MSR
     index to collide with an MSR that KVM emulates

   - Restrict the Xen hypercall MSR index to the unofficial synthetic
     range to reduce the set of possible collisions with MSRs that are
     emulated by KVM (collisions can still happen as KVM emulates
     Hyper-V MSRs, which also reside in the synthetic range)

   - Clean up and optimize KVM's handling of Xen MSR writes and
     xen_hvm_config

   - Update Xen TSC leaves during CPUID emulation instead of modifying
     the CPUID entries when updating PV clocks; there is no guarantee PV
     clocks will be updated between TSC frequency changes and CPUID
     emulation, and guest reads of the TSC leaves should be rare, i.e.
     are not a hot path

  x86 (Intel):

   - Fix a bug where KVM unnecessarily reads XFD_ERR from hardware and
     thus modifies the vCPU's XFD_ERR on a #NM due to CR0.TS=1

   - Pass XFD_ERR as the payload when injecting #NM, as a preparatory
     step for upcoming FRED virtualization support

   - Decouple the EPT entry RWX protection bit macros from the EPT
     Violation bits, both as a general cleanup and in anticipation of
     adding support for emulating Mode-Based Execution Control (MBEC)

   - Reject KVM_RUN if userspace manages to gain control and stuff
     invalid guest state while KVM is in the middle of emulating nested
     VM-Enter

   - Add a macro to handle KVM's sanity checks on entry/exit VMCS
     control pairs in anticipation of adding sanity checks for secondary
     exit controls (the primary field is out of bits)

  x86 (AMD):

   - Ensure the PSP driver is initialized when both the PSP and KVM
     modules are built-in (the initcall framework doesn't handle
     dependencies)

   - Use long-term pins when registering encrypted memory regions, so
     that the pages are migrated out of MIGRATE_CMA/ZONE_MOVABLE and
     don't lead to excessive fragmentation

   - Add macros and helpers for setting GHCB return/error codes

   - Add support for Idle HLT interception, which elides interception if
     the vCPU has a pending, unmasked virtual IRQ when HLT is executed

   - Fix a bug in INVPCID emulation where KVM fails to check for a
     non-canonical address

   - Don't attempt VMRUN for SEV-ES+ guests if the vCPU's VMSA is
     invalid, e.g. because the vCPU was "destroyed" via SNP's AP
     Creation hypercall

   - Reject SNP AP Creation if the requested SEV features for the vCPU
     don't match the VM's configured set of features

  Selftests:

   - Fix again the Intel PMU counters test; add a data load and do
     CLFLUSH{OPT} on the data instead of executing code. The theory is
     that modern Intel CPUs have learned new code prefetching tricks
     that bypass the PMU counters

   - Fix a flaw in the Intel PMU counters test where it asserts that an
     event is counting correctly without actually knowing what the event
     counts on the underlying hardware

   - Fix a variety of flaws, bugs, and false failures/passes
     dirty_log_test, and improve its coverage by collecting all dirty
     entries on each iteration

   - Fix a few minor bugs related to handling of stats FDs

   - Add infrastructure to make vCPU and VM stats FDs available to tests
     by default (open the FDs during VM/vCPU creation)

   - Relax an assertion on the number of HLT exits in the xAPIC IPI test
     when running on a CPU that supports AMD's Idle HLT (which elides
     interception of HLT if a virtual IRQ is pending and unmasked)"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (216 commits)
  RISC-V: KVM: Optimize comments in kvm_riscv_vcpu_isa_disable_allowed
  RISC-V: KVM: Teardown riscv specific bits after kvm_exit
  LoongArch: KVM: Register perf callbacks for guest
  LoongArch: KVM: Implement arch-specific functions for guest perf
  LoongArch: KVM: Add stub for kvm_arch_vcpu_preempted_in_kernel()
  LoongArch: KVM: Remove PGD saving during VM context switch
  LoongArch: KVM: Remove unnecessary header include path
  KVM: arm64: Tear down vGIC on failed vCPU creation
  KVM: arm64: PMU: Reload when resetting
  KVM: arm64: PMU: Reload when user modifies registers
  KVM: arm64: PMU: Fix SET_ONE_REG for vPMC regs
  KVM: arm64: PMU: Assume PMU presence in pmu-emul.c
  KVM: arm64: PMU: Set raw values from user to PM{C,I}NTEN{SET,CLR}, PMOVS{SET,CLR}
  KVM: arm64: Create each pKVM hyp vcpu after its corresponding host vcpu
  KVM: arm64: Factor out pKVM hyp vcpu creation to separate function
  KVM: arm64: Initialize HCRX_EL2 traps in pKVM
  KVM: arm64: Factor out setting HCRX_EL2 traps into separate function
  KVM: x86: block KVM_CAP_SYNC_REGS if guest state is protected
  KVM: x86: Add infrastructure for secure TSC
  KVM: x86: Push down setting vcpu.arch.user_set_tsc
  ...
2025-03-25 14:22:07 -07:00
Linus Torvalds
2d09a9449e arm64 updates for 6.15:
Perf and PMUs:
 
  - Support for the "Rainier" CPU PMU from Arm
 
  - Preparatory driver changes and cleanups that pave the way for BRBE
    support
 
  - Support for partial virtualisation of the Apple-M1 PMU
 
  - Support for the second event filter in Arm CSPMU designs
 
  - Minor fixes and cleanups (CMN and DWC PMUs)
 
  - Enable EL2 requirements for FEAT_PMUv3p9
 
 Power, CPU topology:
 
  - Support for AMUv1-based average CPU frequency
 
  - Run-time SMT control wired up for arm64 (CONFIG_HOTPLUG_SMT). It adds
    a generic topology_is_primary_thread() function overridden by x86 and
    powerpc
 
 New(ish) features:
 
  - MOPS (memcpy/memset) support for the uaccess routines
 
 Security/confidential compute:
 
  - Fix the DMA address for devices used in Realms with Arm CCA. The
    CCA architecture uses the address bit to differentiate between shared
    and private addresses
 
  - Spectre-BHB: assume CPUs Linux doesn't know about vulnerable by
    default
 
 Memory management clean-ups:
 
  - Drop the P*D_TABLE_BIT definition in preparation for 128-bit PTEs
 
  - Some minor page table accessor clean-ups
 
  - PIE/POE (permission indirection/overlay) helpers clean-up
 
 Kselftests:
 
  - MTE: skip hugetlb tests if MTE is not supported on such mappings and
    user correct naming for sync/async tag checking modes
 
 Miscellaneous:
 
  - Add a PKEY_UNRESTRICTED definition as 0 to uapi (toolchain people
    request)
 
  - Sysreg updates for new register fields
 
  - CPU type info for some Qualcomm Kryo cores
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Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 updates from Catalin Marinas:
 "Nothing major this time around.

  Apart from the usual perf/PMU updates, some page table cleanups, the
  notable features are average CPU frequency based on the AMUv1
  counters, CONFIG_HOTPLUG_SMT and MOPS instructions (memcpy/memset) in
  the uaccess routines.

  Perf and PMUs:

   - Support for the 'Rainier' CPU PMU from Arm

   - Preparatory driver changes and cleanups that pave the way for BRBE
     support

   - Support for partial virtualisation of the Apple-M1 PMU

   - Support for the second event filter in Arm CSPMU designs

   - Minor fixes and cleanups (CMN and DWC PMUs)

   - Enable EL2 requirements for FEAT_PMUv3p9

  Power, CPU topology:

   - Support for AMUv1-based average CPU frequency

   - Run-time SMT control wired up for arm64 (CONFIG_HOTPLUG_SMT). It
     adds a generic topology_is_primary_thread() function overridden by
     x86 and powerpc

  New(ish) features:

   - MOPS (memcpy/memset) support for the uaccess routines

  Security/confidential compute:

   - Fix the DMA address for devices used in Realms with Arm CCA. The
     CCA architecture uses the address bit to differentiate between
     shared and private addresses

   - Spectre-BHB: assume CPUs Linux doesn't know about vulnerable by
     default

  Memory management clean-ups:

   - Drop the P*D_TABLE_BIT definition in preparation for 128-bit PTEs

   - Some minor page table accessor clean-ups

   - PIE/POE (permission indirection/overlay) helpers clean-up

  Kselftests:

   - MTE: skip hugetlb tests if MTE is not supported on such mappings
     and user correct naming for sync/async tag checking modes

  Miscellaneous:

   - Add a PKEY_UNRESTRICTED definition as 0 to uapi (toolchain people
     request)

   - Sysreg updates for new register fields

   - CPU type info for some Qualcomm Kryo cores"

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (72 commits)
  arm64: mm: Don't use %pK through printk
  perf/arm_cspmu: Fix missing io.h include
  arm64: errata: Add newer ARM cores to the spectre_bhb_loop_affected() lists
  arm64: cputype: Add MIDR_CORTEX_A76AE
  arm64: errata: Add KRYO 2XX/3XX/4XX silver cores to Spectre BHB safe list
  arm64: errata: Assume that unknown CPUs _are_ vulnerable to Spectre BHB
  arm64: errata: Add QCOM_KRYO_4XX_GOLD to the spectre_bhb_k24_list
  arm64/sysreg: Enforce whole word match for open/close tokens
  arm64/sysreg: Fix unbalanced closing block
  arm64: Kconfig: Enable HOTPLUG_SMT
  arm64: topology: Support SMT control on ACPI based system
  arch_topology: Support SMT control for OF based system
  cpu/SMT: Provide a default topology_is_primary_thread()
  arm64/mm: Define PTDESC_ORDER
  perf/arm_cspmu: Add PMEVFILT2R support
  perf/arm_cspmu: Generalise event filtering
  perf/arm_cspmu: Move register definitons to header
  arm64/kernel: Always use level 2 or higher for early mappings
  arm64/mm: Drop PXD_TABLE_BIT
  arm64/mm: Check pmd_table() in pmd_trans_huge()
  ...
2025-03-25 13:16:16 -07:00
Catalin Marinas
8ae9e2d832 Merge branch 'for-next/smt-control' into for-next/core
* for-next/smt-control:
  : Support SMT control on arm64
  arm64: Kconfig: Enable HOTPLUG_SMT
  arm64: topology: Support SMT control on ACPI based system
  arch_topology: Support SMT control for OF based system
  cpu/SMT: Provide a default topology_is_primary_thread()
2025-03-25 19:32:28 +00:00
Catalin Marinas
8cc14fdcc1 Merge branches 'for-next/amuv1-avg-freq', 'for-next/pkey_unrestricted', 'for-next/sysreg', 'for-next/misc', 'for-next/pgtable-cleanups', 'for-next/kselftest', 'for-next/uaccess-mops', 'for-next/pie-poe-cleanup', 'for-next/cputype-kryo', 'for-next/cca-dma-address', 'for-next/drop-pxd_table_bit' and 'for-next/spectre-bhb-assume-vulnerable', remote-tracking branch 'arm64/for-next/perf' into for-next/core
* arm64/for-next/perf:
  perf/arm_cspmu: Fix missing io.h include
  perf/arm_cspmu: Add PMEVFILT2R support
  perf/arm_cspmu: Generalise event filtering
  perf/arm_cspmu: Move register definitons to header
  drivers/perf: apple_m1: Support host/guest event filtering
  drivers/perf: apple_m1: Refactor event select/filter configuration
  perf/dwc_pcie: fix duplicate pci_dev devices
  perf/dwc_pcie: fix some unreleased resources
  perf/arm-cmn: Minor event type housekeeping
  perf: arm_pmu: Move PMUv3-specific data
  perf: apple_m1: Don't disable counter in m1_pmu_enable_event()
  perf: arm_v7_pmu: Don't disable counter in (armv7|krait_|scorpion_)pmu_enable_event()
  perf: arm_v7_pmu: Drop obvious comments for enabling/disabling counters and interrupts
  perf: arm_pmuv3: Don't disable counter in armv8pmu_enable_event()
  perf: arm_pmu: Don't disable counter in armpmu_add()
  perf: arm_pmuv3: Call kvm_vcpu_pmu_resync_el0() before enabling counters
  perf: arm_pmuv3: Add support for ARM Rainier PMU

* for-next/amuv1-avg-freq:
  : Add support for AArch64 AMUv1-based average freq
  arm64: Utilize for_each_cpu_wrap for reference lookup
  arm64: Update AMU-based freq scale factor on entering idle
  arm64: Provide an AMU-based version of arch_freq_get_on_cpu
  cpufreq: Introduce an optional cpuinfo_avg_freq sysfs entry
  cpufreq: Allow arch_freq_get_on_cpu to return an error
  arch_topology: init capacity_freq_ref to 0

* for-next/pkey_unrestricted:
  : mm/pkey: Add PKEY_UNRESTRICTED macro
  selftest/powerpc/mm/pkey: fix build-break introduced by commit 00894c3fc9
  selftests/powerpc: Use PKEY_UNRESTRICTED macro
  selftests/mm: Use PKEY_UNRESTRICTED macro
  mm/pkey: Add PKEY_UNRESTRICTED macro

* for-next/sysreg:
  : arm64 sysreg updates
  arm64/sysreg: Enforce whole word match for open/close tokens
  arm64/sysreg: Fix unbalanced closing block
  arm64/sysreg: Add register fields for HFGWTR2_EL2
  arm64/sysreg: Add register fields for HFGRTR2_EL2
  arm64/sysreg: Add register fields for HFGITR2_EL2
  arm64/sysreg: Add register fields for HDFGWTR2_EL2
  arm64/sysreg: Add register fields for HDFGRTR2_EL2
  arm64/sysreg: Update register fields for ID_AA64MMFR0_EL1

* for-next/misc:
  : Miscellaneous arm64 patches
  arm64: mm: Don't use %pK through printk
  arm64/fpsimd: Remove unused declaration fpsimd_kvm_prepare()

* for-next/pgtable-cleanups:
  : arm64 pgtable accessors cleanup
  arm64/mm: Define PTDESC_ORDER
  arm64/kernel: Always use level 2 or higher for early mappings
  arm64/hugetlb: Consistently use pud_sect_supported()
  arm64/mm: Convert __pte_to_phys() and __phys_to_pte_val() as functions

* for-next/kselftest:
  : arm64 kselftest updates
  kselftest/arm64: mte: Skip the hugetlb tests if MTE not supported on such mappings
  kselftest/arm64: mte: Use the correct naming for tag check modes in check_hugetlb_options.c

* for-next/uaccess-mops:
  : Implement the uaccess memory copy/set using MOPS instructions
  arm64: lib: Use MOPS for usercopy routines
  arm64: mm: Handle PAN faults on uaccess CPY* instructions
  arm64: extable: Add fixup handling for uaccess CPY* instructions

* for-next/pie-poe-cleanup:
  : PIE/POE helpers cleanup
  arm64/sysreg: Move POR_EL0_INIT to asm/por.h
  arm64/sysreg: Rename POE_RXW to POE_RWX
  arm64/sysreg: Improve PIR/POR helpers

* for-next/cputype-kryo:
  : Add cputype info for some Qualcomm Kryo cores
  arm64: cputype: Add comments about Qualcomm Kryo 5XX and 6XX cores
  arm64: cputype: Add QCOM_CPU_PART_KRYO_3XX_GOLD

* for-next/cca-dma-address:
  : Fix DMA address for devices used in realms with Arm CCA
  arm64: realm: Use aliased addresses for device DMA to shared buffers
  dma: Introduce generic dma_addr_*crypted helpers
  dma: Fix encryption bit clearing for dma_to_phys

* for-next/drop-pxd_table_bit:
  : Drop the arm64 PXD_TABLE_BIT (clean-up in preparation for 128-bit PTEs)
  arm64/mm: Drop PXD_TABLE_BIT
  arm64/mm: Check pmd_table() in pmd_trans_huge()
  arm64/mm: Check PUD_TYPE_TABLE in pud_bad()
  arm64/mm: Check PXD_TYPE_TABLE in [p4d|pgd]_bad()
  arm64/mm: Clear PXX_TYPE_MASK and set PXD_TYPE_SECT in [pmd|pud]_mkhuge()
  arm64/mm: Clear PXX_TYPE_MASK in mk_[pmd|pud]_sect_prot()
  arm64/ptdump: Test PMD_TYPE_MASK for block mapping
  KVM: arm64: ptdump: Test PMD_TYPE_MASK for block mapping

* for-next/spectre-bhb-assume-vulnerable:
  : Rework Spectre BHB mitigations to not assume "safe"
  arm64: errata: Add newer ARM cores to the spectre_bhb_loop_affected() lists
  arm64: cputype: Add MIDR_CORTEX_A76AE
  arm64: errata: Add KRYO 2XX/3XX/4XX silver cores to Spectre BHB safe list
  arm64: errata: Assume that unknown CPUs _are_ vulnerable to Spectre BHB
  arm64: errata: Add QCOM_KRYO_4XX_GOLD to the spectre_bhb_k24_list
2025-03-25 19:32:03 +00:00
Linus Torvalds
317a76a996 Updates for the VDSO infrastructure:
- Consolidate the VDSO storage
 
     The VDSO data storage and data layout has been largely architecture
     specific for historical reasons. That increases the maintenance effort
     and causes inconsistencies over and over.
 
     There is no real technical reason for architecture specific layouts and
     implementations. The architecture specific details can easily be
     integrated into a generic layout, which also reduces the amount of
     duplicated code for managing the mappings.
 
     Convert all architectures over to a unified layout and common mapping
     infrastructure. This splits the VDSO data layout into subsystem
     specific blocks, timekeeping, random and architecture parts, which
     provides a better structure and allows to improve and update the
     functionalities without conflict and interaction.
 
   - Rework the timekeeping data storage
 
     The current implementation is designed for exposing system timekeeping
     accessors, which was good enough at the time when it was designed.
 
     PTP and Time Sensitive Networking (TSN) change that as there are
     requirements to expose independent PTP clocks, which are not related to
     system timekeeping.
 
     Replace the monolithic data storage by a structured layout, which
     allows to add support for independent PTP clocks on top while reusing
     both the data structures and the time accessor implementations.
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Merge tag 'timers-vdso-2025-03-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull VDSO infrastructure updates from Thomas Gleixner:

 - Consolidate the VDSO storage

   The VDSO data storage and data layout has been largely architecture
   specific for historical reasons. That increases the maintenance
   effort and causes inconsistencies over and over.

   There is no real technical reason for architecture specific layouts
   and implementations. The architecture specific details can easily be
   integrated into a generic layout, which also reduces the amount of
   duplicated code for managing the mappings.

   Convert all architectures over to a unified layout and common mapping
   infrastructure. This splits the VDSO data layout into subsystem
   specific blocks, timekeeping, random and architecture parts, which
   provides a better structure and allows to improve and update the
   functionalities without conflict and interaction.

 - Rework the timekeeping data storage

   The current implementation is designed for exposing system
   timekeeping accessors, which was good enough at the time when it was
   designed.

   PTP and Time Sensitive Networking (TSN) change that as there are
   requirements to expose independent PTP clocks, which are not related
   to system timekeeping.

   Replace the monolithic data storage by a structured layout, which
   allows to add support for independent PTP clocks on top while reusing
   both the data structures and the time accessor implementations.

* tag 'timers-vdso-2025-03-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (55 commits)
  sparc/vdso: Always reject undefined references during linking
  x86/vdso: Always reject undefined references during linking
  vdso: Rework struct vdso_time_data and introduce struct vdso_clock
  vdso: Move architecture related data before basetime data
  powerpc/vdso: Prepare introduction of struct vdso_clock
  arm64/vdso: Prepare introduction of struct vdso_clock
  x86/vdso: Prepare introduction of struct vdso_clock
  time/namespace: Prepare introduction of struct vdso_clock
  vdso/namespace: Rename timens_setup_vdso_data() to reflect new vdso_clock struct
  vdso/vsyscall: Prepare introduction of struct vdso_clock
  vdso/gettimeofday: Prepare helper functions for introduction of struct vdso_clock
  vdso/gettimeofday: Prepare do_coarse_timens() for introduction of struct vdso_clock
  vdso/gettimeofday: Prepare do_coarse() for introduction of struct vdso_clock
  vdso/gettimeofday: Prepare do_hres_timens() for introduction of struct vdso_clock
  vdso/gettimeofday: Prepare do_hres() for introduction of struct vdso_clock
  vdso/gettimeofday: Prepare introduction of struct vdso_clock
  vdso/helpers: Prepare introduction of struct vdso_clock
  vdso/datapage: Define vdso_clock to prepare for multiple PTP clocks
  vdso: Make vdso_time_data cacheline aligned
  arm64: Make asm/cache.h compatible with vDSO
  ...
2025-03-25 11:30:42 -07:00
Linus Torvalds
32b22538be Scheduler updates for v6.15:
[ Merge note, these two commits are identical:
 
    - f3fa0e40df ("sched/clock: Don't define sched_clock_irqtime as static key")
    - b9f2b29b94 ("sched: Don't define sched_clock_irqtime as static key")
 
   The first one is a cherry-picked version of the second, and the first one
   is already upstream. ]
 
 Core & fair scheduler changes:
 
   - Cancel the slice protection of the idle entity (Zihan Zhou)
   - Reduce the default slice to avoid tasks getting an extra tick
     (Zihan Zhou)
   - Force propagating min_slice of cfs_rq when {en,de}queue tasks
     (Tianchen Ding)
   - Refactor can_migrate_task() to elimate looping (I Hsin Cheng)
   - Add unlikey branch hints to several system calls (Colin Ian King)
   - Optimize current_clr_polling() on certain architectures (Yujun Dong)
 
 Deadline scheduler: (Juri Lelli)
 
   - Remove redundant dl_clear_root_domain call
   - Move dl_rebuild_rd_accounting to cpuset.h
 
 Uclamp:
 
   - Use the uclamp_is_used() helper instead of open-coding it (Xuewen Yan)
   - Optimize sched_uclamp_used static key enabling (Xuewen Yan)
 
 Scheduler topology support: (Juri Lelli)
 
   - Ignore special tasks when rebuilding domains
   - Add wrappers for sched_domains_mutex
   - Generalize unique visiting of root domains
   - Rebuild root domain accounting after every update
   - Remove partition_and_rebuild_sched_domains
   - Stop exposing partition_sched_domains_locked
 
 RSEQ: (Michael Jeanson)
 
   - Update kernel fields in lockstep with CONFIG_DEBUG_RSEQ=y
   - Fix segfault on registration when rseq_cs is non-zero
   - selftests: Add rseq syscall errors test
   - selftests: Ensure the rseq ABI TLS is actually 1024 bytes
 
 Membarriers:
 
   - Fix redundant load of membarrier_state (Nysal Jan K.A.)
 
 Scheduler debugging:
 
   - Introduce and use preempt_model_str() (Sebastian Andrzej Siewior)
   - Make CONFIG_SCHED_DEBUG unconditional (Ingo Molnar)
 
 Fixes and cleanups:
 
   - Always save/restore x86 TSC sched_clock() on suspend/resume
    (Guilherme G. Piccoli)
 
   - Misc fixes and cleanups (Thorsten Blum, Juri Lelli,
     Sebastian Andrzej Siewior)
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'sched-core-2025-03-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull scheduler updates from Ingo Molnar:
 "Core & fair scheduler changes:

   - Cancel the slice protection of the idle entity (Zihan Zhou)
   - Reduce the default slice to avoid tasks getting an extra tick
     (Zihan Zhou)
   - Force propagating min_slice of cfs_rq when {en,de}queue tasks
     (Tianchen Ding)
   - Refactor can_migrate_task() to elimate looping (I Hsin Cheng)
   - Add unlikey branch hints to several system calls (Colin Ian King)
   - Optimize current_clr_polling() on certain architectures (Yujun
     Dong)

  Deadline scheduler: (Juri Lelli)
   - Remove redundant dl_clear_root_domain call
   - Move dl_rebuild_rd_accounting to cpuset.h

  Uclamp:
   - Use the uclamp_is_used() helper instead of open-coding it (Xuewen
     Yan)
   - Optimize sched_uclamp_used static key enabling (Xuewen Yan)

  Scheduler topology support: (Juri Lelli)
   - Ignore special tasks when rebuilding domains
   - Add wrappers for sched_domains_mutex
   - Generalize unique visiting of root domains
   - Rebuild root domain accounting after every update
   - Remove partition_and_rebuild_sched_domains
   - Stop exposing partition_sched_domains_locked

  RSEQ: (Michael Jeanson)
   - Update kernel fields in lockstep with CONFIG_DEBUG_RSEQ=y
   - Fix segfault on registration when rseq_cs is non-zero
   - selftests: Add rseq syscall errors test
   - selftests: Ensure the rseq ABI TLS is actually 1024 bytes

  Membarriers:
   - Fix redundant load of membarrier_state (Nysal Jan K.A.)

  Scheduler debugging:
   - Introduce and use preempt_model_str() (Sebastian Andrzej Siewior)
   - Make CONFIG_SCHED_DEBUG unconditional (Ingo Molnar)

  Fixes and cleanups:
   - Always save/restore x86 TSC sched_clock() on suspend/resume
     (Guilherme G. Piccoli)
   - Misc fixes and cleanups (Thorsten Blum, Juri Lelli, Sebastian
     Andrzej Siewior)"

* tag 'sched-core-2025-03-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (40 commits)
  cpuidle, sched: Use smp_mb__after_atomic() in current_clr_polling()
  sched/debug: Remove CONFIG_SCHED_DEBUG
  sched/debug: Remove CONFIG_SCHED_DEBUG from self-test config files
  sched/debug, Documentation: Remove (most) CONFIG_SCHED_DEBUG references from documentation
  sched/debug: Make CONFIG_SCHED_DEBUG functionality unconditional
  sched/debug: Make 'const_debug' tunables unconditional __read_mostly
  sched/debug: Change SCHED_WARN_ON() to WARN_ON_ONCE()
  rseq/selftests: Fix namespace collision with rseq UAPI header
  include/{topology,cpuset}: Move dl_rebuild_rd_accounting to cpuset.h
  sched/topology: Stop exposing partition_sched_domains_locked
  cgroup/cpuset: Remove partition_and_rebuild_sched_domains
  sched/topology: Remove redundant dl_clear_root_domain call
  sched/deadline: Rebuild root domain accounting after every update
  sched/deadline: Generalize unique visiting of root domains
  sched/topology: Wrappers for sched_domains_mutex
  sched/deadline: Ignore special tasks when rebuilding domains
  tracing: Use preempt_model_str()
  xtensa: Rely on generic printing of preemption model
  x86: Rely on generic printing of preemption model
  s390: Rely on generic printing of preemption model
  ...
2025-03-24 21:28:12 -07:00
Linus Torvalds
99c21beaab vfs-6.15-rc1.misc
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Merge tag 'vfs-6.15-rc1.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

Pull misc vfs updates from Christian Brauner:
 "Features:

   - Add CONFIG_DEBUG_VFS infrastucture:
      - Catch invalid modes in open
      - Use the new debug macros in inode_set_cached_link()
      - Use debug-only asserts around fd allocation and install

   - Place f_ref to 3rd cache line in struct file to resolve false
     sharing

Cleanups:

   - Start using anon_inode_getfile_fmode() helper in various places

   - Don't take f_lock during SEEK_CUR if exclusion is guaranteed by
     f_pos_lock

   - Add unlikely() to kcmp()

   - Remove legacy ->remount_fs method from ecryptfs after port to the
     new mount api

   - Remove invalidate_inodes() in favour of evict_inodes()

   - Simplify ep_busy_loopER by removing unused argument

   - Avoid mmap sem relocks when coredumping with many missing pages

   - Inline getname()

   - Inline new_inode_pseudo() and de-staticize alloc_inode()

   - Dodge an atomic in putname if ref == 1

   - Consistently deref the files table with rcu_dereference_raw()

   - Dedup handling of struct filename init and refcounts bumps

   - Use wq_has_sleeper() in end_dir_add()

   - Drop the lock trip around I_NEW wake up in evict()

   - Load the ->i_sb pointer once in inode_sb_list_{add,del}

   - Predict not reaching the limit in alloc_empty_file()

   - Tidy up do_sys_openat2() with likely/unlikely

   - Call inode_sb_list_add() outside of inode hash lock

   - Sort out fd allocation vs dup2 race commentary

   - Turn page_offset() into a wrapper around folio_pos()

   - Remove locking in exportfs around ->get_parent() call

   - try_lookup_one_len() does not need any locks in autofs

   - Fix return type of several functions from long to int in open

   - Fix return type of several functions from long to int in ioctls

  Fixes:

   - Fix watch queue accounting mismatch"

* tag 'vfs-6.15-rc1.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (30 commits)
  fs: sort out fd allocation vs dup2 race commentary, take 2
  fs: call inode_sb_list_add() outside of inode hash lock
  fs: tidy up do_sys_openat2() with likely/unlikely
  fs: predict not reaching the limit in alloc_empty_file()
  fs: load the ->i_sb pointer once in inode_sb_list_{add,del}
  fs: drop the lock trip around I_NEW wake up in evict()
  fs: use wq_has_sleeper() in end_dir_add()
  VFS/autofs: try_lookup_one_len() does not need any locks
  fs: dedup handling of struct filename init and refcounts bumps
  fs: consistently deref the files table with rcu_dereference_raw()
  exportfs: remove locking around ->get_parent() call.
  fs: use debug-only asserts around fd allocation and install
  fs: dodge an atomic in putname if ref == 1
  vfs: Remove invalidate_inodes()
  ecryptfs: remove NULL remount_fs from super_operations
  watch_queue: fix pipe accounting mismatch
  fs: place f_ref to 3rd cache line in struct file to resolve false sharing
  epoll: simplify ep_busy_loop by removing always 0 argument
  fs: Turn page_offset() into a wrapper around folio_pos()
  kcmp: improve performance adding an unlikely hint to task comparisons
  ...
2025-03-24 09:13:50 -07:00
Oliver Upton
1b1d1b17b8 Merge branch 'kvm-arm64/pmuv3-asahi' into kvmarm/next
* kvm-arm64/pmuv3-asahi:
  : Support PMUv3 for KVM guests on Apple silicon
  :
  : Take advantage of some IMPLEMENTATION DEFINED traps available on Apple
  : parts to trap-and-emulate the PMUv3 registers on behalf of a KVM guest.
  : Constrain the vPMU to a cycle counter and single event counter, as the
  : Apple PMU has events that cannot be counted on every counter.
  :
  : There is a small new interface between the ARM PMU driver and KVM, where
  : the PMU driver owns the PMUv3 -> hardware event mappings.
  arm64: Enable IMP DEF PMUv3 traps on Apple M*
  KVM: arm64: Provide 1 event counter on IMPDEF hardware
  drivers/perf: apple_m1: Provide helper for mapping PMUv3 events
  KVM: arm64: Remap PMUv3 events onto hardware
  KVM: arm64: Advertise PMUv3 if IMPDEF traps are present
  KVM: arm64: Compute synthetic sysreg ESR for Apple PMUv3 traps
  KVM: arm64: Move PMUVer filtering into KVM code
  KVM: arm64: Use guard() to cleanup usage of arm_pmus_lock
  KVM: arm64: Drop kvm_arm_pmu_available static key
  KVM: arm64: Use a cpucap to determine if system supports FEAT_PMUv3
  KVM: arm64: Always support SW_INCR PMU event
  KVM: arm64: Compute PMCEID from arm_pmu's event bitmaps
  drivers/perf: apple_m1: Support host/guest event filtering
  drivers/perf: apple_m1: Refactor event select/filter configuration

Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-03-19 14:54:23 -07:00
Oliver Upton
d300b0168e Merge branch 'kvm-arm64/pv-cpuid' into kvmarm/next
* kvm-arm64/pv-cpuid:
  : Paravirtualized implementation ID, courtesy of Shameer Kolothum
  :
  : Big-little has historically been a pain in the ass to virtualize. The
  : implementation ID (MIDR, REVIDR, AIDR) of a vCPU can change at the whim
  : of vCPU scheduling. This can be particularly annoying when the guest
  : needs to know the underlying implementation to mitigate errata.
  :
  : "Hyperscalers" face a similar scheduling problem, where VMs may freely
  : migrate between hosts in a pool of heterogenous hardware. And yes, our
  : server-class friends are equally riddled with errata too.
  :
  : In absence of an architected solution to this wart on the ecosystem,
  : introduce support for paravirtualizing the implementation exposed
  : to a VM, allowing the VMM to describe the pool of implementations that a
  : VM may be exposed to due to scheduling/migration.
  :
  : Userspace is expected to intercept and handle these hypercalls using the
  : SMCCC filter UAPI, should it choose to do so.
  smccc: kvm_guest: Fix kernel builds for 32 bit arm
  KVM: selftests: Add test for KVM_REG_ARM_VENDOR_HYP_BMAP_2
  smccc/kvm_guest: Enable errata based on implementation CPUs
  arm64: Make  _midr_in_range_list() an exported function
  KVM: arm64: Introduce KVM_REG_ARM_VENDOR_HYP_BMAP_2
  KVM: arm64: Specify hypercall ABI for retrieving target implementations
  arm64: Modify _midr_range() functions to read MIDR/REVIDR internally

Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-03-19 14:53:16 -07:00
Oliver Upton
13f64f6d21 Merge branch 'kvm-arm64/nv-idregs' into kvmarm/next
* kvm-arm64/nv-idregs:
  : Changes to exposure of NV features, courtesy of Marc Zyngier
  :
  : Apply NV-specific feature restrictions at reset rather than at the point
  : of KVM_RUN. This makes the true feature set visible to userspace, a
  : necessary step towards save/restore support or NV VMs.
  :
  : Add an additional vCPU feature flag for selecting the E2H0 flavor of NV,
  : such that the VHE-ness of the VM can be applied to the feature set.
  KVM: arm64: selftests: Test that TGRAN*_2 fields are writable
  KVM: arm64: Allow userspace to write ID_AA64MMFR0_EL1.TGRAN*_2
  KVM: arm64: Advertise FEAT_ECV when possible
  KVM: arm64: Make ID_AA64MMFR4_EL1.NV_frac writable
  KVM: arm64: Allow userspace to limit NV support to nVHE
  KVM: arm64: Move NV-specific capping to idreg sanitisation
  KVM: arm64: Enforce NV limits on a per-idregs basis
  KVM: arm64: Make ID_REG_LIMIT_FIELD_ENUM() more widely available
  KVM: arm64: Consolidate idreg callbacks
  KVM: arm64: Advertise NV2 in the boot messages
  KVM: arm64: Mark HCR.EL2.{NV*,AT} RES0 when ID_AA64MMFR4_EL1.NV_frac is 0
  KVM: arm64: Mark HCR.EL2.E2H RES0 when ID_AA64MMFR1_EL1.VH is zero
  KVM: arm64: Hide ID_AA64MMFR2_EL1.NV from guest and userspace
  arm64: cpufeature: Handle NV_frac as a synonym of NV2

Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-03-19 14:52:26 -07:00
Sebastian Andrzej Siewior
4769437de0 arm64: Rely on generic printing of preemption model
__die() invokes later show_regs() -> show_regs_print_info() which prints
the current preemption model.
Remove it from the initial line.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Will Deacon <will@kernel.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20250314160810.2373416-5-bigeasy@linutronix.de
2025-03-17 11:23:39 +01:00
Ryan Roberts
86758b5048 mm/ioremap: pass pgprot_t to ioremap_prot() instead of unsigned long
ioremap_prot() currently accepts pgprot_val parameter as an unsigned long,
thus implicitly assuming that pgprot_val and pgprot_t could never be
bigger than unsigned long.  But this assumption soon will not be true on
arm64 when using D128 pgtables.  In 128 bit page table configuration,
unsigned long is 64 bit, but pgprot_t is 128 bit.

Passing platform abstracted pgprot_t argument is better as compared to
size based data types.  Let's change the parameter to directly pass
pgprot_t like another similar helper generic_ioremap_prot().

Without this change in place, D128 configuration does not work on arm64 as
the top 64 bits gets silently stripped when passing the protection value
to this function.

Link: https://lkml.kernel.org/r/20250218101954.415331-1-anshuman.khandual@arm.com
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Co-developed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com> [arm64]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-16 22:06:23 -07:00
Douglas Anderson
a5951389e5 arm64: errata: Add newer ARM cores to the spectre_bhb_loop_affected() lists
When comparing to the ARM list [1], it appears that several ARM cores
were missing from the lists in spectre_bhb_loop_affected(). Add them.

NOTE: for some of these cores it may not matter since other ways of
clearing the BHB may be used (like the CLRBHB instruction or ECBHB),
but it still seems good to have all the info from ARM's whitepaper
included.

[1] https://developer.arm.com/Arm%20Security%20Center/Spectre-BHB

Fixes: 558c303c97 ("arm64: Mitigate spectre style branch history side channels")
Cc: stable@vger.kernel.org
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: James Morse <james.morse@arm.com>
Link: https://lore.kernel.org/r/20250107120555.v4.5.I4a9a527e03f663040721c5401c41de587d015c82@changeid
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2025-03-14 17:58:26 +00:00
Douglas Anderson
0c9fc6e652 arm64: errata: Add KRYO 2XX/3XX/4XX silver cores to Spectre BHB safe list
Qualcomm has confirmed that, much like Cortex A53 and A55, KRYO
2XX/3XX/4XX silver cores are unaffected by Spectre BHB. Add them to
the safe list.

Fixes: 558c303c97 ("arm64: Mitigate spectre style branch history side channels")
Cc: stable@vger.kernel.org
Cc: Scott Bauer <sbauer@quicinc.com>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Acked-by: Trilok Soni <quic_tsoni@quicinc.com>
Link: https://lore.kernel.org/r/20250107120555.v4.3.Iab8dbfb5c9b1e143e7a29f410bce5f9525a0ba32@changeid
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2025-03-14 17:58:25 +00:00
Douglas Anderson
e403e85383 arm64: errata: Assume that unknown CPUs _are_ vulnerable to Spectre BHB
The code for detecting CPUs that are vulnerable to Spectre BHB was
based on a hardcoded list of CPU IDs that were known to be affected.
Unfortunately, the list mostly only contained the IDs of standard ARM
cores. The IDs for many cores that are minor variants of the standard
ARM cores (like many Qualcomm Kyro CPUs) weren't listed. This led the
code to assume that those variants were not affected.

Flip the code on its head and instead assume that a core is vulnerable
if it doesn't have CSV2_3 but is unrecognized as being safe. This
involves creating a "Spectre BHB safe" list.

As of right now, the only CPU IDs added to the "Spectre BHB safe" list
are ARM Cortex A35, A53, A55, A510, and A520. This list was created by
looking for cores that weren't listed in ARM's list [1] as per review
feedback on v2 of this patch [2]. Additionally Brahma A53 is added as
per mailing list feedback [3].

NOTE: this patch will not actually _mitigate_ anyone, it will simply
cause them to report themselves as vulnerable. If any cores in the
system are reported as vulnerable but not mitigated then the whole
system will be reported as vulnerable though the system will attempt
to mitigate with the information it has about the known cores.

[1] https://developer.arm.com/Arm%20Security%20Center/Spectre-BHB
[2] https://lore.kernel.org/r/20241219175128.GA25477@willie-the-truck
[3] https://lore.kernel.org/r/18dbd7d1-a46c-4112-a425-320c99f67a8d@broadcom.com

Fixes: 558c303c97 ("arm64: Mitigate spectre style branch history side channels")
Cc: stable@vger.kernel.org
Reviewed-by: Julius Werner <jwerner@chromium.org>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20250107120555.v4.2.I2040fa004dafe196243f67ebcc647cbedbb516e6@changeid
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2025-03-14 17:58:25 +00:00
Douglas Anderson
ed1ce84124 arm64: errata: Add QCOM_KRYO_4XX_GOLD to the spectre_bhb_k24_list
Qualcomm Kryo 400-series Gold cores have a derivative of an ARM Cortex
A76 in them. Since A76 needs Spectre mitigation via looping then the
Kyro 400-series Gold cores also need Spectre mitigation via looping.

Qualcomm has confirmed that the proper "k" value for Kryo 400-series
Gold cores is 24.

Fixes: 558c303c97 ("arm64: Mitigate spectre style branch history side channels")
Cc: stable@vger.kernel.org
Cc: Scott Bauer <sbauer@quicinc.com>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Acked-by: Trilok Soni <quic_tsoni@quicinc.com>
Link: https://lore.kernel.org/r/20250107120555.v4.1.Ie4ef54abe02e7eb0eee50f830575719bf23bda48@changeid
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2025-03-14 17:58:25 +00:00
Yicong Yang
e6b18ebfaf arm64: topology: Support SMT control on ACPI based system
For ACPI we'll build the topology from PPTT and we cannot directly
get the SMT number of each core. Instead using a temporary xarray
to record the heterogeneous information (from ACPI_PPTT_ACPI_IDENTICAL)
and SMT information of the first core in its heterogeneous CPU cluster
when building the topology. Then we can know the largest SMT number
in the system. If a homogeneous system's using ACPI 6.2 or later,
all the CPUs should be under the root node of PPTT. There'll be
only one entry in the xarray and all the CPUs in the system will
be assumed identical.

The framework's SMT control provides two interface to the users [1]
through /sys/devices/system/cpu/smt/control
(Documentation/ABI/testing/sysfs-devices-system-cpu):

1) enable SMT by writing "on" and disable by "off"
2) enable SMT by writing max_thread_number or disable by writing 1

Both method support to completely disable/enable the SMT cores so both
work correctly for symmetric SMT platform and asymmetric platform with
non-SMT and one type SMT cores like:

core A: 1 thread
core B: X (X!=1) threads

Note that for a theoretically possible multiple SMT-X (X>1) core
platform the SMT control is also supported as expected but only
by writing the "on/off" method.

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Hanjun Guo <guohanjun@huawei.com>
Reviewed-by: Pierre Gondois <pierre.gondois@arm.com>
Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Signed-off-by: Yicong Yang <yangyicong@hisilicon.com>
Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
Link: https://lore.kernel.org/r/20250311075143.61078-4-yangyicong@huawei.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2025-03-14 17:31:05 +00:00
Anshuman Khandual
51ecb29f7a arm64/mm: Define PTDESC_ORDER
Address bytes shifted with a single 64 bit page table entry (any page table
level) has been always hard coded as 3 (aka 2^3 = 8). Although intuitive it
is not very readable or easy to reason about. Besides it is going to change
with D128, where each 128 bit page table entry will shift address bytes by
4 (aka 2^4 = 16) instead.

Let's just formalise this address bytes shift value into a new macro called
PTDESC_ORDER establishing a logical abstraction, thus improving readability
as well. While here re-organize EARLY_LEVEL macro along with its dependents
for better clarity. This does not cause any functional change. Also replace
all (PAGE_SHIFT - PTDESC_ORDER) instances with PTDESC_TABLE_SHIFT.

Cc: Will Deacon <will@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Cc: kasan-dev@googlegroups.com
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Ryan Roberts <ryan.roberts@arm.com>
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Link: https://lore.kernel.org/r/20250311045710.550625-1-anshuman.khandual@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2025-03-14 17:01:23 +00:00
Ard Biesheuvel
bf25266f83 arm64/kernel: Always use level 2 or higher for early mappings
The page table population code in map_range() uses a recursive algorithm
to create the early mappings of the kernel, the DTB and the ID mapped
text and data pages, and this fails to take into account that the way
these page tables may be constructed is not precisely the same at each
level. In particular, block mappings are not permitted at each level,
and the code as it exists today might inadvertently create such a
forbidden block mapping if it were used to map a region of the
appropriate size and alignment.

This never happens in practice, given the limited size of the assets
being mapped by the early boot code. Nonetheless, it would be better if
this code would behave correctly in all circumstances.

So only permit block mappings at level 2, and page mappings at level 3,
for any page size, and use table mappings exclusively at all other
levels. This change should have no impact in practice, but it makes the
code more robust.

Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Reported-by: Ryan Roberts <ryan.roberts@arm.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Ryan Roberts <ryan.roberts@arm.com>
Link: https://lore.kernel.org/r/20250311073043.96795-2-ardb+git@google.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2025-03-13 18:05:55 +00:00
Oliver Upton
e1231aacb0 arm64: Enable IMP DEF PMUv3 traps on Apple M*
Apple M1 and M2 CPUs support IMPDEF traps of the PMUv3 sysregs, allowing
a hypervisor to virtualize an architectural PMU for a VM. Flip the
appropriate bit in HACR_EL2 on supporting hardware.

Tested-by: Janne Grunau <j@jannau.net>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20250305203040.428448-1-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-03-11 12:54:30 -07:00
Oliver Upton
a38b67d151 KVM: arm64: Drop kvm_arm_pmu_available static key
With the PMUv3 cpucap, kvm_arm_pmu_available is no longer used in the
hot path of guest entry/exit. On top of that, guest support for PMUv3
may not correlate with host support for the feature, e.g. on IMPDEF
hardware.

Throw out the static key and just inspect the list of PMUs to determine
if PMUv3 is supported for KVM guests.

Tested-by: Janne Grunau <j@jannau.net>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20250305202641.428114-7-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-03-11 12:54:29 -07:00
Oliver Upton
6f34024d18 KVM: arm64: Use a cpucap to determine if system supports FEAT_PMUv3
KVM is about to learn some new tricks to virtualize PMUv3 on IMPDEF
hardware. As part of that, we now need to differentiate host support
from guest support for PMUv3.

Add a cpucap to determine if an architectural PMUv3 is present to guard
host usage of PMUv3 controls.

Tested-by: Janne Grunau <j@jannau.net>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20250305202641.428114-6-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-03-11 12:54:23 -07:00
Kevin Brodsky
83d78bbfd2 arm64/sysreg: Rename POE_RXW to POE_RWX
It is customary to list R, W, X permissions in that order. In fact
this is already the case for PIE constants (PIE_RWX). Rename POE_RXW
accordingly, as well as POE_XW (currently unused).

While at it also swap the W/X lines in
compute_s1_overlay_permissions() to follow the R, W, X order.

Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com>
Link: https://lore.kernel.org/r/20250219164029.2309119-3-kevin.brodsky@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2025-03-10 18:10:40 +00:00
Kevin Brodsky
f91a3a6088 arm64/sysreg: Improve PIR/POR helpers
We currently have one helper to set a PIRx_ELx's permission field to
a given value, PIRx_ELx_PERM(), and another helper to extract a
permission field from POR_ELx, POR_ELx_IDX(). The naming is pretty
confusing - it isn't clear at all that "_PERM" corresponds to a
setter and "_IDX" to a getter.

This patch aims at improving the situation by using the same
suffixes as FIELD_PREP()/FIELD_GET(), which we have already adopted
for SYS_FIELD_{PREP,GET}():

* PIRx_ELx_PERM_PREP(), POR_ELx_PERM_PREP() create a register value
  where the permission field for a given index is set to a given value.

* POR_ELx_PERM_GET() extracts the permission field from a given
  register value for a given index.

These helpers are not implemented using FIELD_PREP()/FIELD_GET()
because the mask may not be constant, and they need to be usable in
assembly. They are all defined in asm/sysreg.h, as one would expect
for basic sysreg-related helpers.

Finally the new POR_ELx_PERM_* macros are used for existing
calculations in signal.c and mmu.c.

Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com>
Link: https://lore.kernel.org/r/20250219164029.2309119-2-kevin.brodsky@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2025-03-10 18:10:40 +00:00
Sebastian Andrzej Siewior
17a9992dd7 arm64: module: Use RCU in all users of __module_text_address().
__module_text_address() can be invoked within a RCU section, there is no
requirement to have preemption disabled.

Replace the preempt_disable() section around __module_text_address()
with RCU.

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Will Deacon <will@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-trace-kernel@vger.kernel.org
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20250108090457.512198-18-bigeasy@linutronix.de
Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
2025-03-10 11:54:45 +01:00
Ahmed Genidi
3855a7b91d KVM: arm64: Initialize SCTLR_EL1 in __kvm_hyp_init_cpu()
When KVM is in protected mode, host calls to PSCI are proxied via EL2,
and cold entries from CPU_ON, CPU_SUSPEND, and SYSTEM_SUSPEND bounce
through __kvm_hyp_init_cpu() at EL2 before entering the host kernel's
entry point at EL1. While __kvm_hyp_init_cpu() initializes SPSR_EL2 for
the exception return to EL1, it does not initialize SCTLR_EL1.

Due to this, it's possible to enter EL1 with SCTLR_EL1 in an UNKNOWN
state. In practice this has been seen to result in kernel crashes after
CPU_ON as a result of SCTLR_EL1.M being 1 in violation of the initial
core configuration specified by PSCI.

Fix this by initializing SCTLR_EL1 for cold entry to the host kernel.
As it's necessary to write to SCTLR_EL12 in VHE mode, this
initialization is moved into __kvm_host_psci_cpu_entry() where we can
use write_sysreg_el1().

The remnants of the '__init_el2_nvhe_prepare_eret' macro are folded into
its only caller, as this is clearer than having the macro.

Fixes: cdf3671927 ("KVM: arm64: Intercept host's CPU_ON SMCs")
Reported-by: Leo Yan <leo.yan@arm.com>
Signed-off-by: Ahmed Genidi <ahmed.genidi@arm.com>
[ Mark: clarify commit message, handle E2H, move to C, remove macro ]
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Ahmed Genidi <ahmed.genidi@arm.com>
Cc: Ben Horgan <ben.horgan@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Leo Yan <leo.yan@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Oliver Upton <oliver.upton@linux.dev>
Cc: Will Deacon <will@kernel.org>
Reviewed-by: Leo Yan <leo.yan@arm.com>
Link: https://lore.kernel.org/r/20250227180526.1204723-3-mark.rutland@arm.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-03-02 08:36:52 +00:00
Mark Rutland
7a68b55ff3 KVM: arm64: Initialize HCR_EL2.E2H early
On CPUs without FEAT_E2H0, HCR_EL2.E2H is RES1, but may reset to an
UNKNOWN value out of reset and consequently may not read as 1 unless it
has been explicitly initialized.

We handled this for the head.S boot code in commits:

  3944382fa6 ("arm64: Treat HCR_EL2.E2H as RES1 when ID_AA64MMFR4_EL1.E2H0 is negative")
  b3320142f3 ("arm64: Fix early handling of FEAT_E2H0 not being implemented")

Unfortunately, we forgot to apply a similar fix to the KVM PSCI entry
points used when relaying CPU_ON, CPU_SUSPEND, and SYSTEM SUSPEND. When
KVM is entered via these entry points, the value of HCR_EL2.E2H may be
consumed before it has been initialized (e.g. by the 'init_el2_state'
macro).

Initialize HCR_EL2.E2H early in these paths such that it can be consumed
reliably. The existing code in head.S is factored out into a new
'init_el2_hcr' macro, and this is used in the __kvm_hyp_init_cpu()
function common to all the relevant PSCI entry points.

For clarity, I've tweaked the assembly used to check whether
ID_AA64MMFR4_EL1.E2H0 is negative. The bitfield is extracted as a signed
value, and this is checked with a signed-greater-or-equal (GE) comparison.

As the hyp code will reconfigure HCR_EL2 later in ___kvm_hyp_init(), all
bits other than E2H are initialized to zero in __kvm_hyp_init_cpu().

Fixes: 3944382fa6 ("arm64: Treat HCR_EL2.E2H as RES1 when ID_AA64MMFR4_EL1.E2H0 is negative")
Fixes: b3320142f3 ("arm64: Fix early handling of FEAT_E2H0 not being implemented")
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Ahmed Genidi <ahmed.genidi@arm.com>
Cc: Ben Horgan <ben.horgan@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Leo Yan <leo.yan@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Oliver Upton <oliver.upton@linux.dev>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20250227180526.1204723-2-mark.rutland@arm.com
[maz: fixed LT->GE thinko]
Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-03-02 08:36:52 +00:00
Shameer Kolothum
86edf6bdcf smccc/kvm_guest: Enable errata based on implementation CPUs
Retrieve any migration target implementation CPUs using the hypercall
and enable associated errata.

Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Sebastian Ott <sebott@redhat.com>
Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20250221140229.12588-6-shameerali.kolothum.thodi@huawei.com
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-02-26 13:30:37 -08:00
Shameer Kolothum
c8c2647e69 arm64: Make  _midr_in_range_list() an exported function
Subsequent patch will add target implementation CPU support and that
will require _midr_in_range_list() to access new data. To avoid
exporting the data make _midr_in_range_list() a normal function and
export it.

No functional changes intended.

Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20250221140229.12588-5-shameerali.kolothum.thodi@huawei.com
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-02-26 13:30:36 -08:00
Shameer Kolothum
e3121298c7 arm64: Modify _midr_range() functions to read MIDR/REVIDR internally
These changes lay the groundwork for adding support for guest kernels,
allowing them to leverage target CPU implementations provided by the
VMM.

No functional changes intended.

Suggested-by: Oliver Upton <oliver.upton@linux.dev>
Reviewed-by: Sebastian Ott <sebott@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20250221140229.12588-2-shameerali.kolothum.thodi@huawei.com
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-02-26 13:29:44 -08:00
Marc Zyngier
88aea41b9b arm64: cpufeature: Handle NV_frac as a synonym of NV2
With ARMv9.5, an implementation supporting Nested Virtualization
is allowed to only support NV2, and to avoid supporting the old
(and useless) ARMv8.3 variant.

This is indicated by ID_AA64MMFR2_EL1.NV being 0 (as if NV wasn't
implemented) and ID_AA64MMFR4_EL1.NV_frac being 1 (indicating that
NV2 is actually supported).

Given that KVM only deals with NV2 and refuses to use the old NV,
detecting NV2 or NV_frac is what we need to enable it.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Joey Gouly <joey.gouly@arm.com>
Link: https://lore.kernel.org/r/20250220134907.554085-2-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-02-24 11:03:51 -08:00
Beata Michalska
20711efa91 arm64: Utilize for_each_cpu_wrap for reference lookup
While searching for a reference CPU within a given policy,
arch_freq_get_on_cpu relies on cpumask_next_wrap to iterate over
all available CPUs and to ensure each is verified only once.
Recent changes to cpumask_next_wrap will handle the latter no more,
so switching to for_each_cpu_wrap, which  preserves expected behavior
while ensuring compatibility with the updates.
Not to mention that when iterating over each CPU, using a dedicated
iterator is preferable to an open-coded loop.

Fixes: 16d1e27475 ("arm64: Provide an AMU-based version of arch_freq_get_on_cpu")
Signed-off-by: Beata Michalska <beata.michalska@arm.com>
Link: https://lore.kernel.org/r/20250220091015.2319901-1-beata.michalska@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2025-02-21 09:37:52 +00:00
Mateusz Guzik
d6ff4c8f65
fs: avoid mmap sem relocks when coredumping with many missing pages
Dumping processes with large allocated and mostly not-faulted areas is
very slow.

Borrowing a test case from Tavian Barnes:

int main(void) {
    char *mem = mmap(NULL, 1ULL << 40, PROT_READ | PROT_WRITE,
            MAP_ANONYMOUS | MAP_NORESERVE | MAP_PRIVATE, -1, 0);
    printf("%p %m\n", mem);
    if (mem != MAP_FAILED) {
            mem[0] = 1;
    }
    abort();
}

That's 1TB of almost completely not-populated area.

On my test box it takes 13-14 seconds to dump.

The profile shows:
-   99.89%     0.00%  a.out
     entry_SYSCALL_64_after_hwframe
     do_syscall_64
     syscall_exit_to_user_mode
     arch_do_signal_or_restart
   - get_signal
      - 99.89% do_coredump
         - 99.88% elf_core_dump
            - dump_user_range
               - 98.12% get_dump_page
                  - 64.19% __get_user_pages
                     - 40.92% gup_vma_lookup
                        - find_vma
                           - mt_find
                                4.21% __rcu_read_lock
                                1.33% __rcu_read_unlock
                     - 3.14% check_vma_flags
                          0.68% vma_is_secretmem
                       0.61% __cond_resched
                       0.60% vma_pgtable_walk_end
                       0.59% vma_pgtable_walk_begin
                       0.58% no_page_table
                  - 15.13% down_read_killable
                       0.69% __cond_resched
                    13.84% up_read
                 0.58% __cond_resched

Almost 29% of the time is spent relocking the mmap semaphore between
calls to get_dump_page() which find nothing.

Whacking that results in times of 10 seconds (down from 13-14).

While here make the thing killable.

The real problem is the page-sized iteration and the real fix would
patch it up instead. It is left as an exercise for the mm-familiar
reader.

Signed-off-by: Mateusz Guzik <mjguzik@gmail.com>
Link: https://lore.kernel.org/r/20250119103205.2172432-1-mjguzik@gmail.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-02-21 10:25:32 +01:00
Thomas Weißschuh
0b3bc3354e arm64: vdso: Switch to generic storage implementation
The generic storage implementation provides the same features as the
custom one. However it can be shared between architectures, making
maintenance easier.

This switch also moves the random state data out of the time data page.
The currently used hardcoded __VDSO_RND_DATA_OFFSET does not take into
account changes to the time data page layout.

Co-developed-by: Nam Cao <namcao@linutronix.de>
Signed-off-by: Nam Cao <namcao@linutronix.de>
Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20250204-vdso-store-rng-v3-8-13a4669dfc8c@linutronix.de
2025-02-21 09:54:01 +01:00
Thomas Weißschuh
127b0e05c1 vdso: Rename included Makefile
As the Makefile is included into other Makefiles it can not be used to
define objects to be built from the current source directory.
However the generic datastore will introduce such a local source file.
Rename the included Makefile so it is clear how it is to be used and to
make room for a regular Makefile in lib/vdso/.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20250204-vdso-store-rng-v3-4-13a4669dfc8c@linutronix.de
2025-02-21 09:54:01 +01:00
Beata Michalska
39b1997498 arm64: Update AMU-based freq scale factor on entering idle
Now that the frequency scale factor has been activated for retrieving
current frequency on a given CPU, trigger its update upon entering
idle. This will, to an extent, allow querying last known frequency
in a non-invasive way. It will also improve the frequency scale factor
accuracy when a CPU entering idle did not receive a tick for a while.
As a consequence, for idle cores, the reported frequency will be the
last one observed before entering the idle state.

Suggested-by: Vanshidhar Konda <vanshikonda@os.amperecomputing.com>
Signed-off-by: Beata Michalska <beata.michalska@arm.com>
Reviewed-by: Prasanna Kumar T S M <ptsm@linux.microsoft.com>
Reviewed-by: Sumit Gupta <sumitg@nvidia.com>
Link: https://lore.kernel.org/r/20250131162439.3843071-5-beata.michalska@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2025-02-18 13:51:44 +00:00
Beata Michalska
16d1e27475 arm64: Provide an AMU-based version of arch_freq_get_on_cpu
With the Frequency Invariance Engine (FIE) being already wired up with
sched tick and making use of relevant (core counter and constant
counter) AMU counters, getting the average frequency for a given CPU,
can be achieved by utilizing the frequency scale factor which reflects
an average CPU frequency for the last tick period length.

The solution is partially based on APERF/MPERF implementation of
arch_freq_get_on_cpu.

Suggested-by: Ionela Voinescu <ionela.voinescu@arm.com>
Signed-off-by: Beata Michalska <beata.michalska@arm.com>
Reviewed-by: Prasanna Kumar T S M <ptsm@linux.microsoft.com>
Reviewed-by: Sumit Gupta <sumitg@nvidia.com>
Link: https://lore.kernel.org/r/20250131162439.3843071-4-beata.michalska@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2025-02-18 13:51:41 +00:00
Linus Torvalds
82ff316456 ARM:
- Large set of fixes for vector handling, specially in the interactions
   between host and guest state. This fixes a number of bugs affecting
   actual deployments, and greatly simplifies the FP/SIMD/SVE handling.
   Thanks to Mark Rutland for dealing with this thankless task.
 
 - Fix an ugly race between vcpu and vgic creation/init, resulting in
   unexpected behaviours.
 
 - Fix use of kernel VAs at EL2 when emulating timers with nVHE.
 
 - Small set of pKVM improvements and cleanups.
 
 x86:
 
 - Fix broken SNP support with KVM module built-in, ensuring the PSP
   module is initialized before KVM even when the module infrastructure
   cannot be used to order initcalls
 
 - Reject Hyper-V SEND_IPI hypercalls if the local APIC isn't being emulated
   by KVM to fix a NULL pointer dereference.
 
 - Enter guest mode (L2) from KVM's perspective before initializing the vCPU's
   nested NPT MMU so that the MMU is properly tagged for L2, not L1.
 
 - Load the guest's DR6 outside of the innermost .vcpu_run() loop, as the
   guest's value may be stale if a VM-Exit is handled in the fastpath.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull kvm fixes from Paolo Bonzini:
 "ARM:

   - Large set of fixes for vector handling, especially in the
     interactions between host and guest state.

     This fixes a number of bugs affecting actual deployments, and
     greatly simplifies the FP/SIMD/SVE handling. Thanks to Mark Rutland
     for dealing with this thankless task.

   - Fix an ugly race between vcpu and vgic creation/init, resulting in
     unexpected behaviours

   - Fix use of kernel VAs at EL2 when emulating timers with nVHE

   - Small set of pKVM improvements and cleanups

  x86:

   - Fix broken SNP support with KVM module built-in, ensuring the PSP
     module is initialized before KVM even when the module
     infrastructure cannot be used to order initcalls

   - Reject Hyper-V SEND_IPI hypercalls if the local APIC isn't being
     emulated by KVM to fix a NULL pointer dereference

   - Enter guest mode (L2) from KVM's perspective before initializing
     the vCPU's nested NPT MMU so that the MMU is properly tagged for
     L2, not L1

   - Load the guest's DR6 outside of the innermost .vcpu_run() loop, as
     the guest's value may be stale if a VM-Exit is handled in the
     fastpath"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (25 commits)
  x86/sev: Fix broken SNP support with KVM module built-in
  KVM: SVM: Ensure PSP module is initialized if KVM module is built-in
  crypto: ccp: Add external API interface for PSP module initialization
  KVM: arm64: vgic: Hoist SGI/PPI alloc from vgic_init() to kvm_create_vgic()
  KVM: arm64: timer: Drop warning on failed interrupt signalling
  KVM: arm64: Fix alignment of kvm_hyp_memcache allocations
  KVM: arm64: Convert timer offset VA when accessed in HYP code
  KVM: arm64: Simplify warning in kvm_arch_vcpu_load_fp()
  KVM: arm64: Eagerly switch ZCR_EL{1,2}
  KVM: arm64: Mark some header functions as inline
  KVM: arm64: Refactor exit handlers
  KVM: arm64: Refactor CPTR trap deactivation
  KVM: arm64: Remove VHE host restore of CPACR_EL1.SMEN
  KVM: arm64: Remove VHE host restore of CPACR_EL1.ZEN
  KVM: arm64: Remove host FPSIMD saving for non-protected KVM
  KVM: arm64: Unconditionally save+flush host FPSIMD/SVE/SME state
  KVM: x86: Load DR6 with guest value only before entering .vcpu_run() loop
  KVM: nSVM: Enter guest mode before initializing nested NPT MMU
  KVM: selftests: Add CPUID tests for Hyper-V features that need in-kernel APIC
  KVM: selftests: Manage CPUID array in Hyper-V CPUID test's core helper
  ...
2025-02-16 10:25:12 -08:00
Paolo Bonzini
3bb7dcebd0 KVM/arm64 fixes for 6.14, take #2
- Large set of fixes for vector handling, specially in the interactions
   between host and guest state. This fixes a number of bugs affecting
   actual deployments, and greatly simplifies the FP/SIMD/SVE handling.
   Thanks to Mark Rutland for dealing with this thankless task.
 
 - Fix an ugly race between vcpu and vgic creation/init, resulting in
   unexpected behaviours.
 
 - Fix use of kernel VAs at EL2 when emulating timers with nVHE.
 
 - Small set of pKVM improvements and cleanups.
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Merge tag 'kvmarm-fixes-6.14-2' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm64 fixes for 6.14, take #2

- Large set of fixes for vector handling, specially in the interactions
  between host and guest state. This fixes a number of bugs affecting
  actual deployments, and greatly simplifies the FP/SIMD/SVE handling.
  Thanks to Mark Rutland for dealing with this thankless task.

- Fix an ugly race between vcpu and vgic creation/init, resulting in
  unexpected behaviours.

- Fix use of kernel VAs at EL2 when emulating timers with nVHE.

- Small set of pKVM improvements and cleanups.
2025-02-14 18:32:47 -05:00
Mark Rutland
fbc7e61195 KVM: arm64: Unconditionally save+flush host FPSIMD/SVE/SME state
There are several problems with the way hyp code lazily saves the host's
FPSIMD/SVE state, including:

* Host SVE being discarded unexpectedly due to inconsistent
  configuration of TIF_SVE and CPACR_ELx.ZEN. This has been seen to
  result in QEMU crashes where SVE is used by memmove(), as reported by
  Eric Auger:

  https://issues.redhat.com/browse/RHEL-68997

* Host SVE state is discarded *after* modification by ptrace, which was an
  unintentional ptrace ABI change introduced with lazy discarding of SVE state.

* The host FPMR value can be discarded when running a non-protected VM,
  where FPMR support is not exposed to a VM, and that VM uses
  FPSIMD/SVE. In these cases the hyp code does not save the host's FPMR
  before unbinding the host's FPSIMD/SVE/SME state, leaving a stale
  value in memory.

Avoid these by eagerly saving and "flushing" the host's FPSIMD/SVE/SME
state when loading a vCPU such that KVM does not need to save any of the
host's FPSIMD/SVE/SME state. For clarity, fpsimd_kvm_prepare() is
removed and the necessary call to fpsimd_save_and_flush_cpu_state() is
placed in kvm_arch_vcpu_load_fp(). As 'fpsimd_state' and 'fpmr_ptr'
should not be used, they are set to NULL; all uses of these will be
removed in subsequent patches.

Historical problems go back at least as far as v5.17, e.g. erroneous
assumptions about TIF_SVE being clear in commit:

  8383741ab2 ("KVM: arm64: Get rid of host SVE tracking/saving")

... and so this eager save+flush probably needs to be backported to ALL
stable trees.

Fixes: 93ae6b01ba ("KVM: arm64: Discard any SVE state when entering KVM guests")
Fixes: 8c845e2731 ("arm64/sve: Leave SVE enabled on syscall if we don't context switch")
Fixes: ef3be86021 ("KVM: arm64: Add save/restore support for FPMR")
Reported-by: Eric Auger <eauger@redhat.com>
Reported-by: Wilco Dijkstra <wilco.dijkstra@arm.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Tested-by: Eric Auger <eric.auger@redhat.com>
Acked-by: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Florian Weimer <fweimer@redhat.com>
Cc: Fuad Tabba <tabba@google.com>
Cc: Jeremy Linton <jeremy.linton@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Oliver Upton <oliver.upton@linux.dev>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Link: https://lore.kernel.org/r/20250210195226.1215254-2-mark.rutland@arm.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-02-13 17:54:25 +00:00
Mark Brown
a4cc8494f1 arm64: Add missing registrations of hwcaps
Commit 819935464c ("arm64/hwcap: Describe 2024 dpISA extensions to
userspace") added definitions for HWCAP_FPRCVT, HWCAP_F8MM8 and
HWCAP_F8MM4 but did not include the crucial registration in
arm64_elf_hwcaps.  Add it.

Fixes: 819935464c ("arm64/hwcap: Describe 2024 dpISA extensions to userspace")
Reported-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20250212-arm64-fix-2024-dpisa-v2-1-67a1c11d6001@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
2025-02-13 11:13:09 +00:00
Beata Michalska
d923782b04 arm64: amu: Delay allocating cpumask for AMU FIE support
For the time being, the amu_fie_cpus cpumask is being exclusively used
by the AMU-related internals of FIE support and is guaranteed to be
valid on every access currently made. Still the mask is not being
invalidated on one of the error handling code paths, which leaves
a soft spot with theoretical risk of UAF for CPUMASK_OFFSTACK cases.
To make things sound, delay allocating said cpumask
(for CPUMASK_OFFSTACK) avoiding otherwise nasty sanitising case failing
to register the cpufreq policy notifications.

Signed-off-by: Beata Michalska <beata.michalska@arm.com>
Reviewed-by: Prasanna Kumar T S M <ptsm@linux.microsoft.com>
Reviewed-by: Sumit Gupta <sumitg@nvidia.com>
Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
Link: https://lore.kernel.org/r/20250131155842.3839098-1-beata.michalska@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
2025-02-13 11:06:22 +00:00
Radu Rendec
875d742cf5 arm64: cacheinfo: Avoid out-of-bounds write to cacheinfo array
The loop that detects/populates cache information already has a bounds
check on the array size but does not account for cache levels with
separate data/instructions cache. Fix this by incrementing the index
for any populated leaf (instead of any populated level).

Fixes: 5d425c1865 ("arm64: kernel: add support for cpu cache information")

Signed-off-by: Radu Rendec <rrendec@redhat.com>
Link: https://lore.kernel.org/r/20250206174420.2178724-1-rrendec@redhat.com
Signed-off-by: Will Deacon <will@kernel.org>
2025-02-07 09:57:56 +00:00
Nathan Chancellor
ca0f4fe7cf arm64: Handle .ARM.attributes section in linker scripts
A recent LLVM commit [1] started generating an .ARM.attributes section
similar to the one that exists for 32-bit, which results in orphan
section warnings (or errors if CONFIG_WERROR is enabled) from the linker
because it is not handled in the arm64 linker scripts.

  ld.lld: error: arch/arm64/kernel/vdso/vgettimeofday.o:(.ARM.attributes) is being placed in '.ARM.attributes'
  ld.lld: error: arch/arm64/kernel/vdso/vgetrandom.o:(.ARM.attributes) is being placed in '.ARM.attributes'

  ld.lld: error: vmlinux.a(lib/vsprintf.o):(.ARM.attributes) is being placed in '.ARM.attributes'
  ld.lld: error: vmlinux.a(lib/win_minmax.o):(.ARM.attributes) is being placed in '.ARM.attributes'
  ld.lld: error: vmlinux.a(lib/xarray.o):(.ARM.attributes) is being placed in '.ARM.attributes'

Discard the new sections in the necessary linker scripts to resolve the
warnings, as the kernel and vDSO do not need to retain it, similar to
the .note.gnu.property section.

Cc: stable@vger.kernel.org
Fixes: b3e5d80d0c ("arm64/build: Warn on orphan section placement")
Link: ee99c4d484 [1]
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Link: https://lore.kernel.org/r/20250206-arm64-handle-arm-attributes-in-linker-script-v3-1-d53d169913eb@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
2025-02-07 09:56:57 +00:00
Mark Brown
21fed7c223 arm64/hwcap: Remove stray references to SF8MMx
Due to SME currently being disabled when removing the SF8MMx support it
wasn't noticed that there were some stray references in the hwcap table,
delete them.

Fixes: 819935464c ("arm64/hwcap: Describe 2024 dpISA extensions to userspace")
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20250203-arm64-remove-sf8mmx-v1-1-6f1da3dbff82@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
2025-02-04 12:28:18 +00:00
Linus Torvalds
af13ff1c33 Summary:
All ctl_table declared outside of functions and that remain unmodified after
   initialization are const qualified. This prevents unintended modifications to
   proc_handler function pointers by placing them in the .rodata section. This is
   a continuation of the tree-wide effort started a few releases ago with the
   constification of the ctl_table struct arguments in the sysctl API done in
   78eb4ea25c ("sysctl: treewide: constify the ctl_table argument of
   proc_handlers")
 
 Testing:
 
   Testing was done on 0-day and sysctl selftests in x86_64. The linux-next
   branch was not used for such a big change in order to avoid unnecessary merge
   conflicts
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Merge tag 'constfy-sysctl-6.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/sysctl/sysctl

Pull sysctl table constification from Joel Granados:
 "All ctl_table declared outside of functions and that remain unmodified
  after initialization are const qualified.

  This prevents unintended modifications to proc_handler function
  pointers by placing them in the .rodata section.

  This is a continuation of the tree-wide effort started a few releases
  ago with the constification of the ctl_table struct arguments in the
  sysctl API done in 78eb4ea25c ("sysctl: treewide: constify the
  ctl_table argument of proc_handlers")"

* tag 'constfy-sysctl-6.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/sysctl/sysctl:
  treewide: const qualify ctl_tables where applicable
2025-01-29 10:35:40 -08:00
Linus Torvalds
e2ee2e9b15 KVM/arm64 updates for 6.14
* New features:
 
   - Support for non-protected guest in protected mode, achieving near
     feature parity with the non-protected mode
 
   - Support for the EL2 timers as part of the ongoing NV support
 
   - Allow control of hardware tracing for nVHE/hVHE
 
 * Improvements, fixes and cleanups:
 
   - Massive cleanup of the debug infrastructure, making it a bit less
     awkward and definitely easier to maintain. This should pave the
     way for further optimisations
 
   - Complete rewrite of pKVM's fixed-feature infrastructure, aligning
     it with the rest of KVM and making the code easier to follow
 
   - Large simplification of pKVM's memory protection infrastructure
 
   - Better handling of RES0/RES1 fields for memory-backed system
     registers
 
   - Add a workaround for Qualcomm's Snapdragon X CPUs, which suffer
     from a pretty nasty timer bug
 
   - Small collection of cleanups and low-impact fixes
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Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull KVM/arm64 updates from Will Deacon:
 "New features:

   - Support for non-protected guest in protected mode, achieving near
     feature parity with the non-protected mode

   - Support for the EL2 timers as part of the ongoing NV support

   - Allow control of hardware tracing for nVHE/hVHE

  Improvements, fixes and cleanups:

   - Massive cleanup of the debug infrastructure, making it a bit less
     awkward and definitely easier to maintain. This should pave the way
     for further optimisations

   - Complete rewrite of pKVM's fixed-feature infrastructure, aligning
     it with the rest of KVM and making the code easier to follow

   - Large simplification of pKVM's memory protection infrastructure

   - Better handling of RES0/RES1 fields for memory-backed system
     registers

   - Add a workaround for Qualcomm's Snapdragon X CPUs, which suffer
     from a pretty nasty timer bug

   - Small collection of cleanups and low-impact fixes"

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (87 commits)
  arm64/sysreg: Get rid of TRFCR_ELx SysregFields
  KVM: arm64: nv: Fix doc header layout for timers
  KVM: arm64: nv: Apply RESx settings to sysreg reset values
  KVM: arm64: nv: Always evaluate HCR_EL2 using sanitising accessors
  KVM: arm64: Fix selftests after sysreg field name update
  coresight: Pass guest TRFCR value to KVM
  KVM: arm64: Support trace filtering for guests
  KVM: arm64: coresight: Give TRBE enabled state to KVM
  coresight: trbe: Remove redundant disable call
  arm64/sysreg/tools: Move TRFCR definitions to sysreg
  tools: arm64: Update sysreg.h header files
  KVM: arm64: Drop pkvm_mem_transition for host/hyp donations
  KVM: arm64: Drop pkvm_mem_transition for host/hyp sharing
  KVM: arm64: Drop pkvm_mem_transition for FF-A
  KVM: arm64: Explicitly handle BRBE traps as UNDEFINED
  KVM: arm64: vgic: Use str_enabled_disabled() in vgic_v3_probe()
  arm64: kvm: Introduce nvhe stack size constants
  KVM: arm64: Fix nVHE stacktrace VA bits mask
  KVM: arm64: Fix FEAT_MTE in pKVM
  Documentation: Update the behaviour of "kvm-arm.mode"
  ...
2025-01-28 09:01:36 -08:00
Joel Granados
1751f872cc treewide: const qualify ctl_tables where applicable
Add the const qualifier to all the ctl_tables in the tree except for
watchdog_hardlockup_sysctl, memory_allocation_profiling_sysctls,
loadpin_sysctl_table and the ones calling register_net_sysctl (./net,
drivers/inifiniband dirs). These are special cases as they use a
registration function with a non-const qualified ctl_table argument or
modify the arrays before passing them on to the registration function.

Constifying ctl_table structs will prevent the modification of
proc_handler function pointers as the arrays would reside in .rodata.
This is made possible after commit 78eb4ea25c ("sysctl: treewide:
constify the ctl_table argument of proc_handlers") constified all the
proc_handlers.

Created this by running an spatch followed by a sed command:
Spatch:
    virtual patch

    @
    depends on !(file in "net")
    disable optional_qualifier
    @

    identifier table_name != {
      watchdog_hardlockup_sysctl,
      iwcm_ctl_table,
      ucma_ctl_table,
      memory_allocation_profiling_sysctls,
      loadpin_sysctl_table
    };
    @@

    + const
    struct ctl_table table_name [] = { ... };

sed:
    sed --in-place \
      -e "s/struct ctl_table .table = &uts_kern/const struct ctl_table *table = \&uts_kern/" \
      kernel/utsname_sysctl.c

Reviewed-by: Song Liu <song@kernel.org>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org> # for kernel/trace/
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> # SCSI
Reviewed-by: Darrick J. Wong <djwong@kernel.org> # xfs
Acked-by: Jani Nikula <jani.nikula@intel.com>
Acked-by: Corey Minyard <cminyard@mvista.com>
Acked-by: Wei Liu <wei.liu@kernel.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Bill O'Donnell <bodonnel@redhat.com>
Acked-by: Baoquan He <bhe@redhat.com>
Acked-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Acked-by: Anna Schumaker <anna.schumaker@oracle.com>
Signed-off-by: Joel Granados <joel.granados@kernel.org>
2025-01-28 13:48:37 +01:00
Linus Torvalds
9c5968db9e The various patchsets are summarized below. Plus of course many
indivudual patches which are described in their changelogs.
 
 - "Allocate and free frozen pages" from Matthew Wilcox reorganizes the
   page allocator so we end up with the ability to allocate and free
   zero-refcount pages.  So that callers (ie, slab) can avoid a refcount
   inc & dec.
 
 - "Support large folios for tmpfs" from Baolin Wang teaches tmpfs to use
   large folios other than PMD-sized ones.
 
 - "Fix mm/rodata_test" from Petr Tesarik performs some maintenance and
   fixes for this small built-in kernel selftest.
 
 - "mas_anode_descend() related cleanup" from Wei Yang tidies up part of
   the mapletree code.
 
 - "mm: fix format issues and param types" from Keren Sun implements a
   few minor code cleanups.
 
 - "simplify split calculation" from Wei Yang provides a few fixes and a
   test for the mapletree code.
 
 - "mm/vma: make more mmap logic userland testable" from Lorenzo Stoakes
   continues the work of moving vma-related code into the (relatively) new
   mm/vma.c.
 
 - "mm/page_alloc: gfp flags cleanups for alloc_contig_*()" from David
   Hildenbrand cleans up and rationalizes handling of gfp flags in the page
   allocator.
 
 - "readahead: Reintroduce fix for improper RA window sizing" from Jan
   Kara is a second attempt at fixing a readahead window sizing issue.  It
   should reduce the amount of unnecessary reading.
 
 - "synchronously scan and reclaim empty user PTE pages" from Qi Zheng
   addresses an issue where "huge" amounts of pte pagetables are
   accumulated
   (https://lore.kernel.org/lkml/cover.1718267194.git.zhengqi.arch@bytedance.com/).
   Qi's series addresses this windup by synchronously freeing PTE memory
   within the context of madvise(MADV_DONTNEED).
 
 - "selftest/mm: Remove warnings found by adding compiler flags" from
   Muhammad Usama Anjum fixes some build warnings in the selftests code
   when optional compiler warnings are enabled.
 
 - "mm: don't use __GFP_HARDWALL when migrating remote pages" from David
   Hildenbrand tightens the allocator's observance of __GFP_HARDWALL.
 
 - "pkeys kselftests improvements" from Kevin Brodsky implements various
   fixes and cleanups in the MM selftests code, mainly pertaining to the
   pkeys tests.
 
 - "mm/damon: add sample modules" from SeongJae Park enhances DAMON to
   estimate application working set size.
 
 - "memcg/hugetlb: Rework memcg hugetlb charging" from Joshua Hahn
   provides some cleanups to memcg's hugetlb charging logic.
 
 - "mm/swap_cgroup: remove global swap cgroup lock" from Kairui Song
   removes the global swap cgroup lock.  A speedup of 10% for a tmpfs-based
   kernel build was demonstrated.
 
 - "zram: split page type read/write handling" from Sergey Senozhatsky
   has several fixes and cleaups for zram in the area of zram_write_page().
   A watchdog softlockup warning was eliminated.
 
 - "move pagetable_*_dtor() to __tlb_remove_table()" from Kevin Brodsky
   cleans up the pagetable destructor implementations.  A rare
   use-after-free race is fixed.
 
 - "mm/debug: introduce and use VM_WARN_ON_VMG()" from Lorenzo Stoakes
   simplifies and cleans up the debugging code in the VMA merging logic.
 
 - "Account page tables at all levels" from Kevin Brodsky cleans up and
   regularizes the pagetable ctor/dtor handling.  This results in
   improvements in accounting accuracy.
 
 - "mm/damon: replace most damon_callback usages in sysfs with new core
   functions" from SeongJae Park cleans up and generalizes DAMON's sysfs
   file interface logic.
 
 - "mm/damon: enable page level properties based monitoring" from
   SeongJae Park increases the amount of information which is presented in
   response to DAMOS actions.
 
 - "mm/damon: remove DAMON debugfs interface" from SeongJae Park removes
   DAMON's long-deprecated debugfs interfaces.  Thus the migration to sysfs
   is completed.
 
 - "mm/hugetlb: Refactor hugetlb allocation resv accounting" from Peter
   Xu cleans up and generalizes the hugetlb reservation accounting.
 
 - "mm: alloc_pages_bulk: small API refactor" from Luiz Capitulino
   removes a never-used feature of the alloc_pages_bulk() interface.
 
 - "mm/damon: extend DAMOS filters for inclusion" from SeongJae Park
   extends DAMOS filters to support not only exclusion (rejecting), but
   also inclusion (allowing) behavior.
 
 - "Add zpdesc memory descriptor for zswap.zpool" from Alex Shi
   "introduces a new memory descriptor for zswap.zpool that currently
   overlaps with struct page for now.  This is part of the effort to reduce
   the size of struct page and to enable dynamic allocation of memory
   descriptors."
 
 - "mm, swap: rework of swap allocator locks" from Kairui Song redoes and
   simplifies the swap allocator locking.  A speedup of 400% was
   demonstrated for one workload.  As was a 35% reduction for kernel build
   time with swap-on-zram.
 
 - "mm: update mips to use do_mmap(), make mmap_region() internal" from
   Lorenzo Stoakes reworks MIPS's use of mmap_region() so that
   mmap_region() can be made MM-internal.
 
 - "mm/mglru: performance optimizations" from Yu Zhao fixes a few MGLRU
   regressions and otherwise improves MGLRU performance.
 
 - "Docs/mm/damon: add tuning guide and misc updates" from SeongJae Park
   updates DAMON documentation.
 
 - "Cleanup for memfd_create()" from Isaac Manjarres does that thing.
 
 - "mm: hugetlb+THP folio and migration cleanups" from David Hildenbrand
   provides various cleanups in the areas of hugetlb folios, THP folios and
   migration.
 
 - "Uncached buffered IO" from Jens Axboe implements the new
   RWF_DONTCACHE flag which provides synchronous dropbehind for pagecache
   reading and writing.  To permite userspace to address issues with
   massive buildup of useless pagecache when reading/writing fast devices.
 
 - "selftests/mm: virtual_address_range: Reduce memory" from Thomas
   Weißschuh fixes and optimizes some of the MM selftests.
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 -----END PGP SIGNATURE-----

Merge tag 'mm-stable-2025-01-26-14-59' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:
 "The various patchsets are summarized below. Plus of course many
  indivudual patches which are described in their changelogs.

   - "Allocate and free frozen pages" from Matthew Wilcox reorganizes
     the page allocator so we end up with the ability to allocate and
     free zero-refcount pages. So that callers (ie, slab) can avoid a
     refcount inc & dec

   - "Support large folios for tmpfs" from Baolin Wang teaches tmpfs to
     use large folios other than PMD-sized ones

   - "Fix mm/rodata_test" from Petr Tesarik performs some maintenance
     and fixes for this small built-in kernel selftest

   - "mas_anode_descend() related cleanup" from Wei Yang tidies up part
     of the mapletree code

   - "mm: fix format issues and param types" from Keren Sun implements a
     few minor code cleanups

   - "simplify split calculation" from Wei Yang provides a few fixes and
     a test for the mapletree code

   - "mm/vma: make more mmap logic userland testable" from Lorenzo
     Stoakes continues the work of moving vma-related code into the
     (relatively) new mm/vma.c

   - "mm/page_alloc: gfp flags cleanups for alloc_contig_*()" from David
     Hildenbrand cleans up and rationalizes handling of gfp flags in the
     page allocator

   - "readahead: Reintroduce fix for improper RA window sizing" from Jan
     Kara is a second attempt at fixing a readahead window sizing issue.
     It should reduce the amount of unnecessary reading

   - "synchronously scan and reclaim empty user PTE pages" from Qi Zheng
     addresses an issue where "huge" amounts of pte pagetables are
     accumulated:

       https://lore.kernel.org/lkml/cover.1718267194.git.zhengqi.arch@bytedance.com/

     Qi's series addresses this windup by synchronously freeing PTE
     memory within the context of madvise(MADV_DONTNEED)

   - "selftest/mm: Remove warnings found by adding compiler flags" from
     Muhammad Usama Anjum fixes some build warnings in the selftests
     code when optional compiler warnings are enabled

   - "mm: don't use __GFP_HARDWALL when migrating remote pages" from
     David Hildenbrand tightens the allocator's observance of
     __GFP_HARDWALL

   - "pkeys kselftests improvements" from Kevin Brodsky implements
     various fixes and cleanups in the MM selftests code, mainly
     pertaining to the pkeys tests

   - "mm/damon: add sample modules" from SeongJae Park enhances DAMON to
     estimate application working set size

   - "memcg/hugetlb: Rework memcg hugetlb charging" from Joshua Hahn
     provides some cleanups to memcg's hugetlb charging logic

   - "mm/swap_cgroup: remove global swap cgroup lock" from Kairui Song
     removes the global swap cgroup lock. A speedup of 10% for a
     tmpfs-based kernel build was demonstrated

   - "zram: split page type read/write handling" from Sergey Senozhatsky
     has several fixes and cleaups for zram in the area of
     zram_write_page(). A watchdog softlockup warning was eliminated

   - "move pagetable_*_dtor() to __tlb_remove_table()" from Kevin
     Brodsky cleans up the pagetable destructor implementations. A rare
     use-after-free race is fixed

   - "mm/debug: introduce and use VM_WARN_ON_VMG()" from Lorenzo Stoakes
     simplifies and cleans up the debugging code in the VMA merging
     logic

   - "Account page tables at all levels" from Kevin Brodsky cleans up
     and regularizes the pagetable ctor/dtor handling. This results in
     improvements in accounting accuracy

   - "mm/damon: replace most damon_callback usages in sysfs with new
     core functions" from SeongJae Park cleans up and generalizes
     DAMON's sysfs file interface logic

   - "mm/damon: enable page level properties based monitoring" from
     SeongJae Park increases the amount of information which is
     presented in response to DAMOS actions

   - "mm/damon: remove DAMON debugfs interface" from SeongJae Park
     removes DAMON's long-deprecated debugfs interfaces. Thus the
     migration to sysfs is completed

   - "mm/hugetlb: Refactor hugetlb allocation resv accounting" from
     Peter Xu cleans up and generalizes the hugetlb reservation
     accounting

   - "mm: alloc_pages_bulk: small API refactor" from Luiz Capitulino
     removes a never-used feature of the alloc_pages_bulk() interface

   - "mm/damon: extend DAMOS filters for inclusion" from SeongJae Park
     extends DAMOS filters to support not only exclusion (rejecting),
     but also inclusion (allowing) behavior

   - "Add zpdesc memory descriptor for zswap.zpool" from Alex Shi
     introduces a new memory descriptor for zswap.zpool that currently
     overlaps with struct page for now. This is part of the effort to
     reduce the size of struct page and to enable dynamic allocation of
     memory descriptors

   - "mm, swap: rework of swap allocator locks" from Kairui Song redoes
     and simplifies the swap allocator locking. A speedup of 400% was
     demonstrated for one workload. As was a 35% reduction for kernel
     build time with swap-on-zram

   - "mm: update mips to use do_mmap(), make mmap_region() internal"
     from Lorenzo Stoakes reworks MIPS's use of mmap_region() so that
     mmap_region() can be made MM-internal

   - "mm/mglru: performance optimizations" from Yu Zhao fixes a few
     MGLRU regressions and otherwise improves MGLRU performance

   - "Docs/mm/damon: add tuning guide and misc updates" from SeongJae
     Park updates DAMON documentation

   - "Cleanup for memfd_create()" from Isaac Manjarres does that thing

   - "mm: hugetlb+THP folio and migration cleanups" from David
     Hildenbrand provides various cleanups in the areas of hugetlb
     folios, THP folios and migration

   - "Uncached buffered IO" from Jens Axboe implements the new
     RWF_DONTCACHE flag which provides synchronous dropbehind for
     pagecache reading and writing. To permite userspace to address
     issues with massive buildup of useless pagecache when
     reading/writing fast devices

   - "selftests/mm: virtual_address_range: Reduce memory" from Thomas
     Weißschuh fixes and optimizes some of the MM selftests"

* tag 'mm-stable-2025-01-26-14-59' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (321 commits)
  mm/compaction: fix UBSAN shift-out-of-bounds warning
  s390/mm: add missing ctor/dtor on page table upgrade
  kasan: sw_tags: use str_on_off() helper in kasan_init_sw_tags()
  tools: add VM_WARN_ON_VMG definition
  mm/damon/core: use str_high_low() helper in damos_wmark_wait_us()
  seqlock: add missing parameter documentation for raw_seqcount_try_begin()
  mm/page-writeback: consolidate wb_thresh bumping logic into __wb_calc_thresh
  mm/page_alloc: remove the incorrect and misleading comment
  zram: remove zcomp_stream_put() from write_incompressible_page()
  mm: separate move/undo parts from migrate_pages_batch()
  mm/kfence: use str_write_read() helper in get_access_type()
  selftests/mm/mkdirty: fix memory leak in test_uffdio_copy()
  kasan: hw_tags: Use str_on_off() helper in kasan_init_hw_tags()
  selftests/mm: virtual_address_range: avoid reading from VM_IO mappings
  selftests/mm: vm_util: split up /proc/self/smaps parsing
  selftests/mm: virtual_address_range: unmap chunks after validation
  selftests/mm: virtual_address_range: mmap() without PROT_WRITE
  selftests/memfd/memfd_test: fix possible NULL pointer dereference
  mm: add FGP_DONTCACHE folio creation flag
  mm: call filemap_fdatawrite_range_kick() after IOCB_DONTCACHE issue
  ...
2025-01-26 18:36:23 -08:00
Guo Weikang
c6f239796b mm/memblock: add memblock_alloc_or_panic interface
Before SLUB initialization, various subsystems used memblock_alloc to
allocate memory.  In most cases, when memory allocation fails, an
immediate panic is required.  To simplify this behavior and reduce
repetitive checks, introduce `memblock_alloc_or_panic`.  This function
ensures that memory allocation failures result in a panic automatically,
improving code readability and consistency across subsystems that require
this behavior.

[guoweikang.kernel@gmail.com: arch/s390: save_area_alloc default failure behavior changed to panic]
  Link: https://lkml.kernel.org/r/20250109033136.2845676-1-guoweikang.kernel@gmail.com
  Link: https://lore.kernel.org/lkml/Z2fknmnNtiZbCc7x@kernel.org/
Link: https://lkml.kernel.org/r/20250102072528.650926-1-guoweikang.kernel@gmail.com
Signed-off-by: Guo Weikang <guoweikang.kernel@gmail.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>	[m68k]
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>	[s390]
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-01-25 20:22:38 -08:00
Linus Torvalds
1d6d399223 Kthreads affinity follow either of 4 existing different patterns:
1) Per-CPU kthreads must stay affine to a single CPU and never execute
    relevant code on any other CPU. This is currently handled by smpboot
    code which takes care of CPU-hotplug operations. Affinity here is
    a correctness constraint.
 
 2) Some kthreads _have_ to be affine to a specific set of CPUs and can't
    run anywhere else. The affinity is set through kthread_bind_mask()
    and the subsystem takes care by itself to handle CPU-hotplug
    operations. Affinity here is assumed to be a correctness constraint.
 
 3) Per-node kthreads _prefer_ to be affine to a specific NUMA node. This
    is not a correctness constraint but merely a preference in terms of
    memory locality. kswapd and kcompactd both fall into this category.
    The affinity is set manually like for any other task and CPU-hotplug
    is supposed to be handled by the relevant subsystem so that the task
    is properly reaffined whenever a given CPU from the node comes up.
    Also care should be taken so that the node affinity doesn't cross
    isolated (nohz_full) cpumask boundaries.
 
 4) Similar to the previous point except kthreads have a _preferred_
    affinity different than a node. Both RCU boost kthreads and RCU
    exp kworkers fall into this category as they refer to "RCU nodes"
    from a distinctly distributed tree.
 
 Currently the preferred affinity patterns (3 and 4) have at least 4
 identified users, with more or less success when it comes to handle
 CPU-hotplug operations and CPU isolation. Each of which do it in its own
 ad-hoc way.
 
 This is an infrastructure proposal to handle this with the following API
 changes:
 
 _ kthread_create_on_node() automatically affines the created kthread to
   its target node unless it has been set as per-cpu or bound with
   kthread_bind[_mask]() before the first wake-up.
 
 - kthread_affine_preferred() is a new function that can be called right
   after kthread_create_on_node() to specify a preferred affinity
   different than the specified node.
 
 When the preferred affinity can't be applied because the possible
 targets are offline or isolated (nohz_full), the kthread is affine
 to the housekeeping CPUs (which means to all online CPUs most of the
 time or only the non-nohz_full CPUs when nohz_full= is set).
 
 kswapd, kcompactd, RCU boost kthreads and RCU exp kworkers have been
 converted, along with a few old drivers.
 
 Summary of the changes:
 
 * Consolidate a bunch of ad-hoc implementations of kthread_run_on_cpu()
 
 * Introduce task_cpu_fallback_mask() that defines the default last
   resort affinity of a task to become nohz_full aware
 
 * Add some correctness check to ensure kthread_bind() is always called
   before the first kthread wake up.
 
 * Default affine kthread to its preferred node.
 
 * Convert kswapd / kcompactd and remove their halfway working ad-hoc
   affinity implementation
 
 * Implement kthreads preferred affinity
 
 * Unify kthread worker and kthread API's style
 
 * Convert RCU kthreads to the new API and remove the ad-hoc affinity
   implementation.
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Merge tag 'kthread-for-6.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks

Pull kthread updates from Frederic Weisbecker:
 "Kthreads affinity follow either of 4 existing different patterns:

   1) Per-CPU kthreads must stay affine to a single CPU and never
      execute relevant code on any other CPU. This is currently handled
      by smpboot code which takes care of CPU-hotplug operations.
      Affinity here is a correctness constraint.

   2) Some kthreads _have_ to be affine to a specific set of CPUs and
      can't run anywhere else. The affinity is set through
      kthread_bind_mask() and the subsystem takes care by itself to
      handle CPU-hotplug operations. Affinity here is assumed to be a
      correctness constraint.

   3) Per-node kthreads _prefer_ to be affine to a specific NUMA node.
      This is not a correctness constraint but merely a preference in
      terms of memory locality. kswapd and kcompactd both fall into this
      category. The affinity is set manually like for any other task and
      CPU-hotplug is supposed to be handled by the relevant subsystem so
      that the task is properly reaffined whenever a given CPU from the
      node comes up. Also care should be taken so that the node affinity
      doesn't cross isolated (nohz_full) cpumask boundaries.

   4) Similar to the previous point except kthreads have a _preferred_
      affinity different than a node. Both RCU boost kthreads and RCU
      exp kworkers fall into this category as they refer to "RCU nodes"
      from a distinctly distributed tree.

  Currently the preferred affinity patterns (3 and 4) have at least 4
  identified users, with more or less success when it comes to handle
  CPU-hotplug operations and CPU isolation. Each of which do it in its
  own ad-hoc way.

  This is an infrastructure proposal to handle this with the following
  API changes:

   - kthread_create_on_node() automatically affines the created kthread
     to its target node unless it has been set as per-cpu or bound with
     kthread_bind[_mask]() before the first wake-up.

   - kthread_affine_preferred() is a new function that can be called
     right after kthread_create_on_node() to specify a preferred
     affinity different than the specified node.

  When the preferred affinity can't be applied because the possible
  targets are offline or isolated (nohz_full), the kthread is affine to
  the housekeeping CPUs (which means to all online CPUs most of the time
  or only the non-nohz_full CPUs when nohz_full= is set).

  kswapd, kcompactd, RCU boost kthreads and RCU exp kworkers have been
  converted, along with a few old drivers.

  Summary of the changes:

   - Consolidate a bunch of ad-hoc implementations of
     kthread_run_on_cpu()

   - Introduce task_cpu_fallback_mask() that defines the default last
     resort affinity of a task to become nohz_full aware

   - Add some correctness check to ensure kthread_bind() is always
     called before the first kthread wake up.

   - Default affine kthread to its preferred node.

   - Convert kswapd / kcompactd and remove their halfway working ad-hoc
     affinity implementation

   - Implement kthreads preferred affinity

   - Unify kthread worker and kthread API's style

   - Convert RCU kthreads to the new API and remove the ad-hoc affinity
     implementation"

* tag 'kthread-for-6.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks:
  kthread: modify kernel-doc function name to match code
  rcu: Use kthread preferred affinity for RCU exp kworkers
  treewide: Introduce kthread_run_worker[_on_cpu]()
  kthread: Unify kthread_create_on_cpu() and kthread_create_worker_on_cpu() automatic format
  rcu: Use kthread preferred affinity for RCU boost
  kthread: Implement preferred affinity
  mm: Create/affine kswapd to its preferred node
  mm: Create/affine kcompactd to its preferred node
  kthread: Default affine kthread to its preferred NUMA node
  kthread: Make sure kthread hasn't started while binding it
  sched,arm64: Handle CPU isolation on last resort fallback rq selection
  arm64: Exclude nohz_full CPUs from 32bits el0 support
  lib: test_objpool: Use kthread_run_on_cpu()
  kallsyms: Use kthread_run_on_cpu()
  soc/qman: test: Use kthread_run_on_cpu()
  arm/bL_switcher: Use kthread_run_on_cpu()
2025-01-21 17:10:05 -08:00
Linus Torvalds
2e04247f7c ftrace updates for v6.14:
- Have fprobes built on top of function graph infrastructure
 
   The fprobe logic is an optimized kprobe that uses ftrace to attach to
   functions when a probe is needed at the start or end of the function. The
   fprobe and kretprobe logic implements a similar method as the function
   graph tracer to trace the end of the function. That is to hijack the
   return address and jump to a trampoline to do the trace when the function
   exits. To do this, a shadow stack needs to be created to store the
   original return address.  Fprobes and function graph do this slightly
   differently. Fprobes (and kretprobes) has slots per callsite that are
   reserved to save the return address. This is fine when just a few points
   are traced. But users of fprobes, such as BPF programs, are starting to add
   many more locations, and this method does not scale.
 
   The function graph tracer was created to trace all functions in the
   kernel. In order to do this, when function graph tracing is started, every
   task gets its own shadow stack to hold the return address that is going to
   be traced. The function graph tracer has been updated to allow multiple
   users to use its infrastructure. Now have fprobes be one of those users.
   This will also allow for the fprobe and kretprobe methods to trace the
   return address to become obsolete. With new technologies like CFI that
   need to know about these methods of hijacking the return address, going
   toward a solution that has only one method of doing this will make the
   kernel less complex.
 
 - Cleanup with guard() and free() helpers
 
   There were several places in the code that had a lot of "goto out" in the
   error paths to either unlock a lock or free some memory that was
   allocated. But this is error prone. Convert the code over to use the
   guard() and free() helpers that let the compiler unlock locks or free
   memory when the function exits.
 
 - Remove disabling of interrupts in the function graph tracer
 
   When function graph tracer was first introduced, it could race with
   interrupts and NMIs. To prevent that race, it would disable interrupts and
   not trace NMIs. But the code has changed to allow NMIs and also
   interrupts. This change was done a long time ago, but the disabling of
   interrupts was never removed. Remove the disabling of interrupts in the
   function graph tracer is it is not needed. This greatly improves its
   performance.
 
 - Allow the :mod: command to enable tracing module functions on the kernel
   command line.
 
   The function tracer already has a way to enable functions to be traced in
   modules by writing ":mod:<module>" into set_ftrace_filter. That will
   enable either all the functions for the module if it is loaded, or if it
   is not, it will cache that command, and when the module is loaded that
   matches <module>, its functions will be enabled. This also allows init
   functions to be traced. But currently events do not have that feature.
 
   Because enabling function tracing can be done very early at boot up
   (before scheduling is enabled), the commands that can be done when
   function tracing is started is limited. Having the ":mod:" command to
   trace module functions as they are loaded is very useful. Update the
   kernel command line function filtering to allow it.
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Merge tag 'ftrace-v6.14' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull ftrace updates from Steven Rostedt:

 - Have fprobes built on top of function graph infrastructure

   The fprobe logic is an optimized kprobe that uses ftrace to attach to
   functions when a probe is needed at the start or end of the function.
   The fprobe and kretprobe logic implements a similar method as the
   function graph tracer to trace the end of the function. That is to
   hijack the return address and jump to a trampoline to do the trace
   when the function exits. To do this, a shadow stack needs to be
   created to store the original return address. Fprobes and function
   graph do this slightly differently. Fprobes (and kretprobes) has
   slots per callsite that are reserved to save the return address. This
   is fine when just a few points are traced. But users of fprobes, such
   as BPF programs, are starting to add many more locations, and this
   method does not scale.

   The function graph tracer was created to trace all functions in the
   kernel. In order to do this, when function graph tracing is started,
   every task gets its own shadow stack to hold the return address that
   is going to be traced. The function graph tracer has been updated to
   allow multiple users to use its infrastructure. Now have fprobes be
   one of those users. This will also allow for the fprobe and kretprobe
   methods to trace the return address to become obsolete. With new
   technologies like CFI that need to know about these methods of
   hijacking the return address, going toward a solution that has only
   one method of doing this will make the kernel less complex.

 - Cleanup with guard() and free() helpers

   There were several places in the code that had a lot of "goto out" in
   the error paths to either unlock a lock or free some memory that was
   allocated. But this is error prone. Convert the code over to use the
   guard() and free() helpers that let the compiler unlock locks or free
   memory when the function exits.

 - Remove disabling of interrupts in the function graph tracer

   When function graph tracer was first introduced, it could race with
   interrupts and NMIs. To prevent that race, it would disable
   interrupts and not trace NMIs. But the code has changed to allow NMIs
   and also interrupts. This change was done a long time ago, but the
   disabling of interrupts was never removed. Remove the disabling of
   interrupts in the function graph tracer is it is not needed. This
   greatly improves its performance.

 - Allow the :mod: command to enable tracing module functions on the
   kernel command line.

   The function tracer already has a way to enable functions to be
   traced in modules by writing ":mod:<module>" into set_ftrace_filter.
   That will enable either all the functions for the module if it is
   loaded, or if it is not, it will cache that command, and when the
   module is loaded that matches <module>, its functions will be
   enabled. This also allows init functions to be traced. But currently
   events do not have that feature.

   Because enabling function tracing can be done very early at boot up
   (before scheduling is enabled), the commands that can be done when
   function tracing is started is limited. Having the ":mod:" command to
   trace module functions as they are loaded is very useful. Update the
   kernel command line function filtering to allow it.

* tag 'ftrace-v6.14' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (26 commits)
  ftrace: Implement :mod: cache filtering on kernel command line
  tracing: Adopt __free() and guard() for trace_fprobe.c
  bpf: Use ftrace_get_symaddr() for kprobe_multi probes
  ftrace: Add ftrace_get_symaddr to convert fentry_ip to symaddr
  Documentation: probes: Update fprobe on function-graph tracer
  selftests/ftrace: Add a test case for repeating register/unregister fprobe
  selftests: ftrace: Remove obsolate maxactive syntax check
  tracing/fprobe: Remove nr_maxactive from fprobe
  fprobe: Add fprobe_header encoding feature
  fprobe: Rewrite fprobe on function-graph tracer
  s390/tracing: Enable HAVE_FTRACE_GRAPH_FUNC
  ftrace: Add CONFIG_HAVE_FTRACE_GRAPH_FUNC
  bpf: Enable kprobe_multi feature if CONFIG_FPROBE is enabled
  tracing/fprobe: Enable fprobe events with CONFIG_DYNAMIC_FTRACE_WITH_ARGS
  tracing: Add ftrace_fill_perf_regs() for perf event
  tracing: Add ftrace_partial_regs() for converting ftrace_regs to pt_regs
  fprobe: Use ftrace_regs in fprobe exit handler
  fprobe: Use ftrace_regs in fprobe entry handler
  fgraph: Pass ftrace_regs to retfunc
  fgraph: Replace fgraph_ret_regs with ftrace_regs
  ...
2025-01-21 15:15:28 -08:00
Linus Torvalds
4c551165e7 Updates for the interrupt subsystem:
- Consolidation of the machine_kexec_mask_interrupts() by providing a
     generic implementation and replacing the copy & pasta orgy in the
     relevant architectures.
 
   - Prevent unconditional operations on interrupt chips during kexec
     shutdown, which can trigger warnings in certain cases when the
     underlying interrupt has been shut down before.
 
   - Make the enforcement of interrupt handling in interrupt context
     unconditionally available, so that it actually works for non x86
     related interrupt chips. The earlier enablement for ARM GIC chips set
     the required chip flag, but did not notice that the check was hidden
     behind a config switch which is not selected by ARM[64].
 
   - Decrapify the handling of deferred interrupt affinity setting. Some
     interrupt chips require that affinity changes are made from the context
     of handling an interrupt to avoid certain race conditions. For x86 this
     was the default, but with interrupt remapping this requirement was
     lifted and a flag was introduced which tells the core code that
     affinity changes can be done in any context. Unrestricted affinity
     changes are the default for the majority of interrupt chips. RISCV has
     the requirement to add the deferred mode to one of it's interrupt
     controllers, but with the original implementation this would require to
     add the any context flag to all other RISC-V interrupt chips. That's
     backwards, so reverse the logic and require that chips, which need the
     deferred mode have to be marked accordingly. That avoids chasing the
     'sane' chips and marking them.
 
   - Add multi-node support to the Loongarch AVEC interrupt controller
     driver.
 
   - The usual tiny cleanups, fixes and improvements all over the place.
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Merge tag 'irq-core-2025-01-21' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull interrupt subsystem updates from Thomas Gleixner:

 - Consolidate the machine_kexec_mask_interrupts() by providing a
   generic implementation and replacing the copy & pasta orgy in the
   relevant architectures.

 - Prevent unconditional operations on interrupt chips during kexec
   shutdown, which can trigger warnings in certain cases when the
   underlying interrupt has been shut down before.

 - Make the enforcement of interrupt handling in interrupt context
   unconditionally available, so that it actually works for non x86
   related interrupt chips. The earlier enablement for ARM GIC chips set
   the required chip flag, but did not notice that the check was hidden
   behind a config switch which is not selected by ARM[64].

 - Decrapify the handling of deferred interrupt affinity setting.

   Some interrupt chips require that affinity changes are made from the
   context of handling an interrupt to avoid certain race conditions.
   For x86 this was the default, but with interrupt remapping this
   requirement was lifted and a flag was introduced which tells the core
   code that affinity changes can be done in any context. Unrestricted
   affinity changes are the default for the majority of interrupt chips.

   RISCV has the requirement to add the deferred mode to one of it's
   interrupt controllers, but with the original implementation this
   would require to add the any context flag to all other RISC-V
   interrupt chips. That's backwards, so reverse the logic and require
   that chips, which need the deferred mode have to be marked
   accordingly. That avoids chasing the 'sane' chips and marking them.

 - Add multi-node support to the Loongarch AVEC interrupt controller
   driver.

 - The usual tiny cleanups, fixes and improvements all over the place.

* tag 'irq-core-2025-01-21' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  genirq/generic_chip: Export irq_gc_mask_disable_and_ack_set()
  genirq/timings: Add kernel-doc for a function parameter
  genirq: Remove IRQ_MOVE_PCNTXT and related code
  x86/apic: Convert to IRQCHIP_MOVE_DEFERRED
  genirq: Provide IRQCHIP_MOVE_DEFERRED
  hexagon: Remove GENERIC_PENDING_IRQ leftover
  ARC: Remove GENERIC_PENDING_IRQ
  genirq: Remove handle_enforce_irqctx() wrapper
  genirq: Make handle_enforce_irqctx() unconditionally available
  irqchip/loongarch-avec: Add multi-nodes topology support
  irqchip/ts4800: Replace seq_printf() by seq_puts()
  irqchip/ti-sci-inta : Add module build support
  irqchip/ti-sci-intr: Add module build support
  irqchip/irq-brcmstb-l2: Replace brcmstb_l2_mask_and_ack() by generic function
  irqchip: keystone: Use syscon_regmap_lookup_by_phandle_args
  genirq/kexec: Prevent redundant IRQ masking by checking state before shutdown
  kexec: Consolidate machine_kexec_mask_interrupts() implementation
  genirq: Reuse irq_thread_fn() for forced thread case
  genirq: Move irq_thread_fn() further up in the code
2025-01-21 13:51:07 -08:00
Linus Torvalds
9ad09c4f28 arm64 updates for 6.14
Confidential Computing:
 * Register a platform device when running in CCA realm mode to enable
   automatic loading of dependent modules.
 
 CPU Features:
 * Update a bunch of system register definitions to pick up new field
   encodings from the architectural documentation.
 
 * Add hwcaps and selftests for the new (2024) dpISA extensions.
 
 Documentation:
 * Update EL3 (firmware) requirements for booting Linux on modern arm64
   designs.
 
 * Remove stale information about the kernel virtual memory map.
 
 Miscellaneous:
 * Minor cleanups and typo fixes.
 
 Memory management:
 * Fix vmemmap_check_pmd() to look at the PMD type bits
 
 * LPA2 (52-bit physical addressing) cleanups and minor fixes.
 
 * Adjust physical address space depending upon whether or not LPA2 is
   enabled.
 
 Perf and PMUs:
 * Add port filtering support for NVIDIA's NVLINK-C2C Coresight PMU
 
 * Extend AXI filtering support for the DDR PMU on NXP IMX SoCs
 
 * Fix Designware PCIe PMU event numbering.
 
 * Add generic branch events for the Apple M1 CPU PMU.
 
 * Add support for Marvell Odyssey DDR and LLC-TAD PMUs.
 
 * Cleanups to the Hisilicon DDRC and Uncore PMU code.
 
 * Advertise discard mode for the SPE PMU.
 
 * Add the perf users mailing list to our MAINTAINERS entry.
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Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 updates from Will Deacon:
 "We've got a little less than normal thanks to the holidays in
  December, but there's the usual summary below. The highlight is
  probably the 52-bit physical addressing (LPA2) clean-up from Ard.

  Confidential Computing:

   - Register a platform device when running in CCA realm mode to enable
     automatic loading of dependent modules

  CPU Features:

   - Update a bunch of system register definitions to pick up new field
     encodings from the architectural documentation

   - Add hwcaps and selftests for the new (2024) dpISA extensions

  Documentation:

   - Update EL3 (firmware) requirements for booting Linux on modern
     arm64 designs

   - Remove stale information about the kernel virtual memory map

  Miscellaneous:

   - Minor cleanups and typo fixes

  Memory management:

   - Fix vmemmap_check_pmd() to look at the PMD type bits

   - LPA2 (52-bit physical addressing) cleanups and minor fixes

   - Adjust physical address space depending upon whether or not LPA2 is
     enabled

  Perf and PMUs:

   - Add port filtering support for NVIDIA's NVLINK-C2C Coresight PMU

   - Extend AXI filtering support for the DDR PMU on NXP IMX SoCs

   - Fix Designware PCIe PMU event numbering

   - Add generic branch events for the Apple M1 CPU PMU

   - Add support for Marvell Odyssey DDR and LLC-TAD PMUs

   - Cleanups to the Hisilicon DDRC and Uncore PMU code

   - Advertise discard mode for the SPE PMU

   - Add the perf users mailing list to our MAINTAINERS entry"

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (64 commits)
  Documentation: arm64: Remove stale and redundant virtual memory diagrams
  perf docs: arm_spe: Document new discard mode
  perf: arm_spe: Add format option for discard mode
  MAINTAINERS: Add perf list for drivers/perf/
  arm64: Remove duplicate included header
  drivers/perf: apple_m1: Map generic branch events
  arm64: rsi: Add automatic arm-cca-guest module loading
  kselftest/arm64: Add 2024 dpISA extensions to hwcap test
  KVM: arm64: Allow control of dpISA extensions in ID_AA64ISAR3_EL1
  arm64/hwcap: Describe 2024 dpISA extensions to userspace
  arm64/sysreg: Update ID_AA64SMFR0_EL1 to DDI0601 2024-12
  arm64: Filter out SVE hwcaps when FEAT_SVE isn't implemented
  drivers/perf: hisi: Set correct IRQ affinity for PMUs with no association
  arm64/sme: Move storage of reg_smidr to __cpuinfo_store_cpu()
  arm64: mm: Test for pmd_sect() in vmemmap_check_pmd()
  arm64/mm: Replace open encodings with PXD_TABLE_BIT
  arm64/mm: Rename pte_mkpresent() as pte_mkvalid()
  arm64/sysreg: Update ID_AA64ISAR2_EL1 to DDI0601 2024-09
  arm64/sysreg: Update ID_AA64ZFR0_EL1 to DDI0601 2024-09
  arm64/sysreg: Update ID_AA64FPFR0_EL1 to DDI0601 2024-09
  ...
2025-01-20 21:21:49 -08:00
Will Deacon
602ffd4ce3 Merge branch 'for-next/mm' into for-next/core
* for-next/mm:
  arm64: mm: Test for pmd_sect() in vmemmap_check_pmd()
  arm64/mm: Replace open encodings with PXD_TABLE_BIT
  arm64/mm: Rename pte_mkpresent() as pte_mkvalid()
  arm64: Kconfig: force ARM64_PAN=y when enabling TTBR0 sw PAN
  arm64/kvm: Avoid invalid physical addresses to signal owner updates
  arm64/kvm: Configure HYP TCR.PS/DS based on host stage1
  arm64/mm: Override PARange for !LPA2 and use it consistently
  arm64/mm: Reduce PA space to 48 bits when LPA2 is not enabled
2025-01-17 13:52:33 +00:00
Will Deacon
763d584c5b Merge branch 'for-next/cpufeature' into for-next/core
* for-next/cpufeature:
  kselftest/arm64: Add 2024 dpISA extensions to hwcap test
  KVM: arm64: Allow control of dpISA extensions in ID_AA64ISAR3_EL1
  arm64/hwcap: Describe 2024 dpISA extensions to userspace
  arm64/sysreg: Update ID_AA64SMFR0_EL1 to DDI0601 2024-12
  arm64: Filter out SVE hwcaps when FEAT_SVE isn't implemented
  arm64/sme: Move storage of reg_smidr to __cpuinfo_store_cpu()
  arm64/sysreg: Update ID_AA64ISAR2_EL1 to DDI0601 2024-09
  arm64/sysreg: Update ID_AA64ZFR0_EL1 to DDI0601 2024-09
  arm64/sysreg: Update ID_AA64FPFR0_EL1 to DDI0601 2024-09
  arm64/sysreg: Update ID_AA64ISAR3_EL1 to DDI0601 2024-09
  arm64/sysreg: Update ID_AA64PFR2_EL1 to DDI0601 2024-09
  arm64/sysreg: Get rid of CPACR_ELx SysregFields
  arm64/sysreg: Convert *_EL12 accessors to Mapping
  arm64/sysreg: Get rid of the TCR2_EL1x SysregFields
  arm64/sysreg: Allow a 'Mapping' descriptor for system registers
  arm64/cpufeature: Refactor conditional logic in init_cpu_ftr_reg()
  arm64: cpufeature: Add HAFT to cpucap_is_possible()
2025-01-17 13:52:15 +00:00
Marc Zyngier
080612b294 Merge branch kvm-arm64/nv-timers into kvmarm-master/next
* kvm-arm64/nv-timers:
  : .
  : Nested Virt support for the EL2 timers. From the initial cover letter:
  :
  : "Here's another batch of NV-related patches, this time bringing in most
  : of the timer support for EL2 as well as nested guests.
  :
  : The code is pretty convoluted for a bunch of reasons:
  :
  : - FEAT_NV2 breaks the timer semantics by redirecting HW controls to
  :   memory, meaning that a guest could setup a timer and never see it
  :   firing until the next exit
  :
  : - We go try hard to reflect the timer state in memory, but that's not
  :   great.
  :
  : - With FEAT_ECV, we can finally correctly emulate the virtual timer,
  :   but this emulation is pretty costly
  :
  : - As a way to make things suck less, we handle timer reads as early as
  :   possible, and only defer writes to the normal trap handling
  :
  : - Finally, some implementations are badly broken, and require some
  :   hand-holding, irrespective of NV support. So we try and reuse the NV
  :   infrastructure to make them usable. This could be further optimised,
  :   but I'm running out of patience for this sort of HW.
  :
  : [...]"
  : .
  KVM: arm64: nv: Fix doc header layout for timers
  KVM: arm64: nv: Document EL2 timer API
  KVM: arm64: Work around x1e's CNTVOFF_EL2 bogosity
  KVM: arm64: nv: Sanitise CNTHCTL_EL2
  KVM: arm64: nv: Propagate CNTHCTL_EL2.EL1NV{P,V}CT bits
  KVM: arm64: nv: Add trap routing for CNTHCTL_EL2.EL1{NVPCT,NVVCT,TVT,TVCT}
  KVM: arm64: Handle counter access early in non-HYP context
  KVM: arm64: nv: Accelerate EL0 counter accesses from hypervisor context
  KVM: arm64: nv: Accelerate EL0 timer read accesses when FEAT_ECV in use
  KVM: arm64: nv: Use FEAT_ECV to trap access to EL0 timers
  KVM: arm64: nv: Publish emulated timer interrupt state in the in-memory state
  KVM: arm64: nv: Sync nested timer state with FEAT_NV2
  KVM: arm64: nv: Add handling of EL2-specific timer registers

Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-01-17 11:04:53 +00:00
Marc Zyngier
4e26de25d2 Merge remote-tracking branch 'arm64/for-next/cpufeature' into kvm-arm64/pkvm-fixed-features-6.14
Merge arm64/for-next/cpufeature to solve extensive conflicts
caused by the CPACR_ELx->CPACR_EL1 repainting.

Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-01-11 14:55:18 +00:00
Frederic Weisbecker
3a5446612a sched,arm64: Handle CPU isolation on last resort fallback rq selection
When a kthread or any other task has an affinity mask that is fully
offline or unallowed, the scheduler reaffines the task to all possible
CPUs as a last resort.

This default decision doesn't mix up very well with nohz_full CPUs that
are part of the possible cpumask but don't want to be disturbed by
unbound kthreads or even detached pinned user tasks.

Make the fallback affinity setting aware of nohz_full.

Suggested-by: Michal Hocko <mhocko@suse.com>
Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
2025-01-08 18:14:23 +01:00
Frederic Weisbecker
4a1567b466 arm64: Exclude nohz_full CPUs from 32bits el0 support
Nohz full CPUs are not a desirable fallback target to run 32bits el0
applications. If present, prefer a set of housekeeping CPUs that can do
the job instead. Otherwise just don't support el0 32 bits. Should the
need arise, appropriate support can be introduced in the future.

Suggested-by: Will Deacon <will@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
2025-01-08 18:13:29 +01:00
Jeremy Linton
a1edec2245 arm64: rsi: Add automatic arm-cca-guest module loading
The TSM module provides guest identification and attestation when a
guest runs in CCA realm mode. By creating a dummy platform device,
let's ensure the module is automatically loaded. The udev daemon loads
the TSM module after it receives a device addition event. Once that
happens, it can be used earlier in the boot process to decrypt the
rootfs.

Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Link: https://lore.kernel.org/r/20241220181236.172060-2-jeremy.linton@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
2025-01-08 13:58:49 +00:00
Mark Brown
819935464c arm64/hwcap: Describe 2024 dpISA extensions to userspace
The 2024 dpISA introduces a number of architecture features all of which
only add new instructions so only require the addition of hwcaps and ID
register visibility.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20250107-arm64-2024-dpisa-v5-3-7578da51fc3d@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
2025-01-08 13:41:06 +00:00
Marc Zyngier
064737920b arm64: Filter out SVE hwcaps when FEAT_SVE isn't implemented
The hwcaps code that exposes SVE features to userspace only
considers ID_AA64ZFR0_EL1, while this is only valid when
ID_AA64PFR0_EL1.SVE advertises that SVE is actually supported.

The expectations are that when ID_AA64PFR0_EL1.SVE is 0, the
ID_AA64ZFR0_EL1 register is also 0. So far, so good.

Things become a bit more interesting if the HW implements SME.
In this case, a few ID_AA64ZFR0_EL1 fields indicate *SME*
features. And these fields overlap with their SVE interpretations.
But the architecture says that the SME and SVE feature sets must
match, so we're still hunky-dory.

This goes wrong if the HW implements SME, but not SVE. In this
case, we end-up advertising some SVE features to userspace, even
if the HW has none. That's because we never consider whether SVE
is actually implemented. Oh well.

Fix it by restricting all SVE capabilities to ID_AA64PFR0_EL1.SVE
being non-zero. The HWCAPS documentation is amended to reflect the
actually checks performed by the kernel.

Fixes: 06a916feca ("arm64: Expose SVE2 features for userspace")
Reported-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: Will Deacon <will@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: stable@vger.kernel.org
Reviewed-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20250107-arm64-2024-dpisa-v5-1-7578da51fc3d@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
2025-01-08 13:41:06 +00:00
Mark Brown
d3c7c48d00 arm64/sme: Move storage of reg_smidr to __cpuinfo_store_cpu()
In commit 892f7237b3 ("arm64: Delay initialisation of
cpuinfo_arm64::reg_{zcr,smcr}") we moved access to ZCR, SMCR and SMIDR
later in the boot process in order to ensure that we don't attempt to
interact with them if SVE or SME is disabled on the command line.
Unfortunately when initialising the boot CPU in init_cpu_features() we work
on a copy of the struct cpuinfo_arm64 for the boot CPU used only during
boot, not the percpu copy used by the sysfs code. The expectation of the
feature identification code was that the ID registers would be read in
__cpuinfo_store_cpu() and the values not modified by init_cpu_features().

The main reason for the original change was to avoid early accesses to
ZCR on practical systems that were seen shipping with SVE reported in ID
registers but traps enabled at EL3 and handled as fatal errors, SME was
rolled in due to the similarity with SVE. Since then we have removed the
early accesses to ZCR and SMCR in commits:

  abef0695f9 ("arm64/sve: Remove ZCR pseudo register from cpufeature code")
  391208485c ("arm64/sve: Remove SMCR pseudo register from cpufeature code")

so only the SMIDR_EL1 part of the change remains. Since SMIDR_EL1 is
only trapped via FEAT_IDST and not the SME trap it is less likely to be
affected by similar issues, and the factors that lead to issues with SVE
are less likely to apply to SME.

Since we have not yet seen practical SME systems that need to use a
command line override (and are only just beginning to see SME systems at
all) and the ID register read is much more likely to be safe let's just
store SMIDR_EL1 along with all the other ID register reads in
__cpuinfo_store_cpu().

This issue wasn't apparent when testing on emulated platforms that do not
report values in SMIDR_EL1.

Fixes: 892f7237b3 ("arm64: Delay initialisation of cpuinfo_arm64::reg_{zcr,smcr}")
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20241217-arm64-fix-boot-cpu-smidr-v3-1-7be278a85623@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
2025-01-07 17:15:55 +00:00
Marc Zyngier
0bc9a9e85f KVM: arm64: Work around x1e's CNTVOFF_EL2 bogosity
It appears that on Qualcomm's x1e CPU, CNTVOFF_EL2 doesn't really
work, specially with HCR_EL2.E2H=1.

A non-zero offset results in a screaming virtual timer interrupt,
to the tune of a few 100k interrupts per second on a 4 vcpu VM.
This is also evidenced by this CPU's inability to correctly run
any of the timer selftests.

The only case this doesn't break is when this register is set to 0,
which breaks VM migration.

When HCR_EL2.E2H=0, the timer seems to behave normally, and does
not result in an interrupt storm.

As a workaround, use the fact that this CPU implements FEAT_ECV,
and trap all accesses to the virtual timer and counter, keeping
CNTVOFF_EL2 set to zero, and emulate accesses to CVAL/TVAL/CTL
and the counter itself, fixing up the timer to account for the
missing offset.

And if you think this is disgusting, you'd probably be right.

Acked-by: Oliver Upton <oliver.upton@linux.dev>
Link: https://lore.kernel.org/r/20241217142321.763801-12-maz@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-01-02 19:19:10 +00:00
Masami Hiramatsu (Google)
2bc56fdae1 ftrace: Add ftrace_get_symaddr to convert fentry_ip to symaddr
This introduces ftrace_get_symaddr() which tries to convert fentry_ip
passed by ftrace or fgraph callback to symaddr without calling
kallsyms API. It returns the symbol address or 0 if it fails to
convert it.

Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Florent Revest <revest@chromium.org>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: bpf <bpf@vger.kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Alan Maguire <alan.maguire@oracle.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/173519011487.391279.5450806886342723151.stgit@devnote2
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202412061423.K79V55Hd-lkp@intel.com/
Closes: https://lore.kernel.org/oe-kbuild-all/202412061804.5VRzF14E-lkp@intel.com/
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-12-26 10:50:07 -05:00
Masami Hiramatsu (Google)
a3ed4157b7 fgraph: Replace fgraph_ret_regs with ftrace_regs
Use ftrace_regs instead of fgraph_ret_regs for tracing return value
on function_graph tracer because of simplifying the callback interface.

The CONFIG_HAVE_FUNCTION_GRAPH_RETVAL is also replaced by
CONFIG_HAVE_FUNCTION_GRAPH_FREGS.

Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Acked-by: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Florent Revest <revest@chromium.org>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: bpf <bpf@vger.kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Alan Maguire <alan.maguire@oracle.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: WANG Xuerui <kernel@xen0n.name>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: x86@kernel.org
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/173518991508.391279.16635322774382197642.stgit@devnote2
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-12-26 10:50:02 -05:00
Masami Hiramatsu (Google)
41705c4262 fgraph: Pass ftrace_regs to entryfunc
Pass ftrace_regs to the fgraph_ops::entryfunc(). If ftrace_regs is not
available, it passes a NULL instead. User callback function can access
some registers (including return address) via this ftrace_regs.

Note that the ftrace_regs can be NULL when the arch does NOT define:
HAVE_DYNAMIC_FTRACE_WITH_ARGS or HAVE_DYNAMIC_FTRACE_WITH_REGS.
More specifically, if HAVE_DYNAMIC_FTRACE_WITH_REGS is defined but
not the HAVE_DYNAMIC_FTRACE_WITH_ARGS, and the ftrace ops used to
register the function callback does not set FTRACE_OPS_FL_SAVE_REGS.
In this case, ftrace_regs can be NULL in user callback.

Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Florent Revest <revest@chromium.org>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: bpf <bpf@vger.kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Alan Maguire <alan.maguire@oracle.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: WANG Xuerui <kernel@xen0n.name>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Naveen N Rao <naveen@kernel.org>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: x86@kernel.org
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/173518990044.391279.17406984900626078579.stgit@devnote2
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-12-26 10:50:02 -05:00
Linus Torvalds
499551201b Fix a sparse warning in the arm64 signal code dealing with the user
shadow stack register, GCSPR_EL0.
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Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 fix from Catalin Marinas:
 "Fix a sparse warning in the arm64 signal code dealing with the user
  shadow stack register, GCSPR_EL0"

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64/signal: Silence sparse warning storing GCSPR_EL0
2024-12-20 14:10:01 -08:00
Mark Brown
926e862058 arm64/signal: Silence sparse warning storing GCSPR_EL0
We are seeing a sparse warning in gcs_restore_signal():

  arch/arm64/kernel/signal.c:1054:9: sparse: sparse: cast removes address space '__user' of expression

when storing the final GCSPR_EL0 value back into the register, caused by
the fact that write_sysreg_s() casts the value it writes to a u64 which
sparse sees as discarding the __userness of the pointer.

Avoid this by treating the address as an integer, casting to a pointer only
when using it to write to userspace.

While we're at it also inline gcs_signal_cap_valid() into it's one user
and make equivalent updates to gcs_signal_entry().

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202412082005.OBJ0BbWs-lkp@intel.com/
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20241214-arm64-gcs-signal-sparse-v3-1-5e8d18fffc0c@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-12-20 14:12:04 +00:00
Marc Zyngier
e5ecedcd7c arm64/sysreg: Get rid of CPACR_ELx SysregFields
There is no such thing as CPACR_ELx in the architecture.
What we have is CPACR_EL1, for which CPTR_EL12 is an accessor.

Rename CPACR_ELx_* to CPACR_EL1_*, and fix the bit of code using
these names.

Reviewed-by: Mark Brown <broonie@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20241219173351.1123087-5-maz@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
2024-12-19 18:00:58 +00:00
Marc Zyngier
7052e808c4 arm64/sysreg: Get rid of the TCR2_EL1x SysregFields
TCR2_EL1x is a pretty bizarre construct, as it is shared between
TCR2_EL1 and TCR2_EL12. But the latter is obviously only an
accessor to the former.

In order to make things more consistent, upgrade TCR2_EL1x to
a full-blown sysreg definition for TCR2_EL1, and describe TCR2_EL12
as a mapping to TCR2_EL1.

This results in a couple of minor changes to the actual code.

Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20241219173351.1123087-3-maz@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
2024-12-19 18:00:58 +00:00
Ard Biesheuvel
62cffa496a arm64/mm: Override PARange for !LPA2 and use it consistently
When FEAT_LPA{,2} are not implemented, the ID_AA64MMFR0_EL1.PARange and
TCR.IPS values corresponding with 52-bit physical addressing are
reserved.

Setting the TCR.IPS field to 0b110 (52-bit physical addressing) has side
effects, such as how the TTBRn_ELx.BADDR fields are interpreted, and so
it is important that disabling FEAT_LPA2 (by overriding the
ID_AA64MMFR0.TGran fields) also presents a PARange field consistent with
that.

So limit the field to 48 bits unless LPA2 is enabled, and update
existing references to use the override consistently.

Fixes: 352b0395b5 ("arm64: Enable 52-bit virtual addressing for 4k and 16k granule configs")
Cc: stable@vger.kernel.org
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20241212081841.2168124-10-ardb+git@google.com
Signed-off-by: Will Deacon <will@kernel.org>
2024-12-19 17:23:52 +00:00
Linus Torvalds
81576a9a27 ARM64:
* Fix confusion with implicitly-shifted MDCR_EL2 masks breaking
   SPE/TRBE initialization.
 
 * Align nested page table walker with the intended memory attribute
   combining rules of the architecture.
 
 * Prevent userspace from constraining the advertised ASID width,
   avoiding horrors of guest TLBIs not matching the intended context in
   hardware.
 
 * Don't leak references on LPIs when insertion into the translation
   cache fails.
 
 RISC-V:
 
 * Replace csr_write() with csr_set() for HVIEN PMU overflow bit.
 
 x86:
 
 * Cache CPUID.0xD XSTATE offsets+sizes during module init - On Intel's
   Emerald Rapids CPUID costs hundreds of cycles and there are a lot of
   leaves under 0xD.  Getting rid of the CPUIDs during nested VM-Enter and
   VM-Exit is planned for the next release, for now just cache them: even
   on Skylake that is 40% faster.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull kvm fixes from Paolo Bonzini:
 "ARM64:

   - Fix confusion with implicitly-shifted MDCR_EL2 masks breaking
     SPE/TRBE initialization

   - Align nested page table walker with the intended memory attribute
     combining rules of the architecture

   - Prevent userspace from constraining the advertised ASID width,
     avoiding horrors of guest TLBIs not matching the intended context
     in hardware

   - Don't leak references on LPIs when insertion into the translation
     cache fails

  RISC-V:

   - Replace csr_write() with csr_set() for HVIEN PMU overflow bit

  x86:

   - Cache CPUID.0xD XSTATE offsets+sizes during module init

     On Intel's Emerald Rapids CPUID costs hundreds of cycles and there
     are a lot of leaves under 0xD. Getting rid of the CPUIDs during
     nested VM-Enter and VM-Exit is planned for the next release, for
     now just cache them: even on Skylake that is 40% faster"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: x86: Cache CPUID.0xD XSTATE offsets+sizes during module init
  RISC-V: KVM: Fix csr_write -> csr_set for HVIEN PMU overflow bit
  KVM: arm64: vgic-its: Add error handling in vgic_its_cache_translation
  KVM: arm64: Do not allow ID_AA64MMFR0_EL1.ASIDbits to be overridden
  KVM: arm64: Fix S1/S2 combination when FWB==1 and S2 has Device memory type
  arm64: Fix usage of new shifted MDCR_EL2 values
2024-12-15 09:26:13 -08:00
Kevin Brodsky
a3b4647e2f arm64: signal: Ensure signal delivery failure is recoverable
Commit eaf62ce156 ("arm64/signal: Set up and restore the GCS
context for signal handlers") introduced a potential failure point
at the end of setup_return(). This is unfortunate as it is too late
to deliver a SIGSEGV: if that SIGSEGV is handled, the subsequent
sigreturn will end up returning to the original handler, which is
not the intention (since we failed to deliver that signal).

Make sure this does not happen by calling gcs_signal_entry()
at the very beginning of setup_return(), and add a comment just
after to discourage error cases being introduced from that point
onwards.

While at it, also take care of copy_siginfo_to_user(): since it may
fail, we shouldn't be calling it after setup_return() either. Call
it before setup_return() instead, and move the setting of X1/X2
inside setup_return() where it belongs (after the "point of no
failure").

Background: the first part of setup_rt_frame(), including
setup_sigframe(), has no impact on the execution of the interrupted
thread. The signal frame is written to the stack, but the stack
pointer remains unchanged. Failure at this stage can be recovered by
a SIGSEGV handler, and sigreturn will restore the original context,
at the point where the original signal occurred. On the other hand,
once setup_return() has updated registers including SP, the thread's
control flow has been modified and we must deliver the original
signal.

Fixes: eaf62ce156 ("arm64/signal: Set up and restore the GCS context for signal handlers")
Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com>
Reviewed-by: Dave Martin <Dave.Martin@arm.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20241210160940.2031997-1-kevin.brodsky@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-12-13 14:13:27 +00:00
Mark Rutland
65ac33bed8 arm64: stacktrace: Don't WARN when unwinding other tasks
The arm64 stacktrace code has a few error conditions where a
WARN_ON_ONCE() is triggered before the stacktrace is terminated and an
error is returned to the caller. The conditions shouldn't be triggered
when unwinding the current task, but it is possible to trigger these
when unwinding another task which is not blocked, as the stack of that
task is concurrently modified. Kent reports that these warnings can be
triggered while running filesystem tests on bcachefs, which calls the
stacktrace code directly.

To produce a meaningful stacktrace of another task, the task in question
should be blocked, but the stacktrace code is expected to be robust to
cases where it is not blocked. Note that this is purely about not
unuduly scaring the user and/or crashing the kernel; stacktraces in such
cases are meaningless and may leak kernel secrets from the stack of the
task being unwound.

Ideally we'd pin the task in a blocked state during the unwind, as we do
for /proc/${PID}/wchan since commit:

  42a20f86dc ("sched: Add wrapper for get_wchan() to keep task blocked")

... but a bunch of places don't do that, notably /proc/${PID}/stack,
where we don't pin the task in a blocked state, but do restrict the
output to privileged users since commit:

  f8a00cef17 ("proc: restrict kernel stack dumps to root")

... and so it's possible to trigger these warnings accidentally, e.g. by
reading /proc/*/stack (as root):

| for n in $(seq 1 10); do
|     while true; do cat /proc/*/stack > /dev/null 2>&1; done &
| done
| ------------[ cut here ]------------
| WARNING: CPU: 3 PID: 166 at arch/arm64/kernel/stacktrace.c:207 arch_stack_walk+0x1c8/0x370
| Modules linked in:
| CPU: 3 UID: 0 PID: 166 Comm: cat Not tainted 6.13.0-rc2-00003-g3dafa7a7925d #2
| Hardware name: linux,dummy-virt (DT)
| pstate: 81400005 (Nzcv daif +PAN -UAO -TCO +DIT -SSBS BTYPE=--)
| pc : arch_stack_walk+0x1c8/0x370
| lr : arch_stack_walk+0x1b0/0x370
| sp : ffff800080773890
| x29: ffff800080773930 x28: fff0000005c44500 x27: fff00000058fa038
| x26: 000000007ffff000 x25: 0000000000000000 x24: 0000000000000000
| x23: ffffa35a8d9600ec x22: 0000000000000000 x21: fff00000043a33c0
| x20: ffff800080773970 x19: ffffa35a8d960168 x18: 0000000000000000
| x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000
| x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000000
| x11: 0000000000000000 x10: 0000000000000000 x9 : 0000000000000000
| x8 : ffff8000807738e0 x7 : ffff8000806e3800 x6 : ffff8000806e3818
| x5 : ffff800080773920 x4 : ffff8000806e4000 x3 : ffff8000807738e0
| x2 : 0000000000000018 x1 : ffff8000806e3800 x0 : 0000000000000000
| Call trace:
|  arch_stack_walk+0x1c8/0x370 (P)
|  stack_trace_save_tsk+0x8c/0x108
|  proc_pid_stack+0xb0/0x134
|  proc_single_show+0x60/0x120
|  seq_read_iter+0x104/0x438
|  seq_read+0xf8/0x140
|  vfs_read+0xc4/0x31c
|  ksys_read+0x70/0x108
|  __arm64_sys_read+0x1c/0x28
|  invoke_syscall+0x48/0x104
|  el0_svc_common.constprop.0+0x40/0xe0
|  do_el0_svc+0x1c/0x28
|  el0_svc+0x30/0xcc
|  el0t_64_sync_handler+0x10c/0x138
|  el0t_64_sync+0x198/0x19c
| ---[ end trace 0000000000000000 ]---

Fix this by only warning when unwinding the current task. When unwinding
another task the error conditions will be handled by returning an error
without producing a warning.

The two warnings in kunwind_next_frame_record_meta() were added recently
as part of commit:

  c2c6b27b5a ("arm64: stacktrace: unwind exception boundaries")

The warning when recovering the fgraph return address has changed form
many times, but was originally introduced back in commit:

  9f416319f4 ("arm64: fix unwind_frame() for filtered out fn for function graph tracing")

Fixes: c2c6b27b5a ("arm64: stacktrace: unwind exception boundaries")
Fixes: 9f416319f4 ("arm64: fix unwind_frame() for filtered out fn for function graph tracing")
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reported-by: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Kees Cook <keescook@chromium.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20241211140704.2498712-3-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-12-12 16:23:15 +00:00
Mark Rutland
32ed120568 arm64: stacktrace: Skip reporting LR at exception boundaries
Aishwarya reports that warnings are sometimes seen when running the
ftrace kselftests, e.g.

| WARNING: CPU: 5 PID: 2066 at arch/arm64/kernel/stacktrace.c:141 arch_stack_walk+0x4a0/0x4c0
| Modules linked in:
| CPU: 5 UID: 0 PID: 2066 Comm: ftracetest Not tainted 6.13.0-rc2 #2
| Hardware name: linux,dummy-virt (DT)
| pstate: 604000c5 (nZCv daIF +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
| pc : arch_stack_walk+0x4a0/0x4c0
| lr : arch_stack_walk+0x248/0x4c0
| sp : ffff800083643d20
| x29: ffff800083643dd0 x28: ffff00007b891400 x27: ffff00007b891928
| x26: 0000000000000001 x25: 00000000000000c0 x24: ffff800082f39d80
| x23: ffff80008003ee8c x22: ffff80008004baa8 x21: ffff8000800533e0
| x20: ffff800083643e10 x19: ffff80008003eec8 x18: 0000000000000000
| x17: 0000000000000000 x16: ffff800083640000 x15: 0000000000000000
| x14: 02a37a802bbb8a92 x13: 00000000000001a9 x12: 0000000000000001
| x11: ffff800082ffad60 x10: ffff800083643d20 x9 : ffff80008003eed0
| x8 : ffff80008004baa8 x7 : ffff800086f2be80 x6 : ffff0000057cf000
| x5 : 0000000000000000 x4 : 0000000000000000 x3 : ffff800086f2b690
| x2 : ffff80008004baa8 x1 : ffff80008004baa8 x0 : ffff80008004baa8
| Call trace:
|  arch_stack_walk+0x4a0/0x4c0 (P)
|  arch_stack_walk+0x248/0x4c0 (L)
|  profile_pc+0x44/0x80
|  profile_tick+0x50/0x80 (F)
|  tick_nohz_handler+0xcc/0x160 (F)
|  __hrtimer_run_queues+0x2ac/0x340 (F)
|  hrtimer_interrupt+0xf4/0x268 (F)
|  arch_timer_handler_virt+0x34/0x60 (F)
|  handle_percpu_devid_irq+0x88/0x220 (F)
|  generic_handle_domain_irq+0x34/0x60 (F)
|  gic_handle_irq+0x54/0x140 (F)
|  call_on_irq_stack+0x24/0x58 (F)
|  do_interrupt_handler+0x88/0x98
|  el1_interrupt+0x34/0x68 (F)
|  el1h_64_irq_handler+0x18/0x28
|  el1h_64_irq+0x6c/0x70
|  queued_spin_lock_slowpath+0x78/0x460 (P)

The warning in question is:

  WARN_ON_ONCE(state->common.pc == orig_pc))

... in kunwind_recover_return_address(), which is triggered when
return_to_handler() is encountered in the trace, but
ftrace_graph_ret_addr() cannot find a corresponding original return
address on the fgraph return stack.

This happens because the stacktrace code encounters an exception
boundary where the LR was not live at the time of the exception, but the
LR happens to contain return_to_handler(); either because the task
recently returned there, or due to unfortunate usage of the LR at a
scratch register. In such cases attempts to recover the return address
via ftrace_graph_ret_addr() may fail, triggering the WARN_ON_ONCE()
above and aborting the unwind (hence the stacktrace terminating after
reporting the PC at the time of the exception).

Handling unreliable LR values in these cases is likely to require some
larger rework, so for the moment avoid this problem by restoring the old
behaviour of skipping the LR at exception boundaries, which the
stacktrace code did prior to commit:

  c2c6b27b5a ("arm64: stacktrace: unwind exception boundaries")

This commit is effectively a partial revert, keeping the structures and
logic to explicitly identify exception boundaries while still skipping
reporting of the LR. The logic to explicitly identify exception
boundaries is still useful for general robustness and as a building
block for future support for RELIABLE_STACKTRACE.

Fixes: c2c6b27b5a ("arm64: stacktrace: unwind exception boundaries")
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reported-by: Aishwarya TCV <aishwarya.tcv@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20241211140704.2498712-2-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-12-12 16:23:05 +00:00
Eliav Farber
bad6722e47 kexec: Consolidate machine_kexec_mask_interrupts() implementation
Consolidate the machine_kexec_mask_interrupts implementation into a common
function located in a new file: kernel/irq/kexec.c. This removes duplicate
implementations from architecture-specific files in arch/arm, arch/arm64,
arch/powerpc, and arch/riscv, reducing code duplication and improving
maintainability.

The new implementation retains architecture-specific behavior for
CONFIG_GENERIC_IRQ_KEXEC_CLEAR_VM_FORWARD, which was previously implemented
for ARM64. When enabled (currently for ARM64), it clears the active state
of interrupts forwarded to virtual machines (VMs) before handling other
interrupt masking operations.

Signed-off-by: Eliav Farber <farbere@amazon.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20241204142003.32859-2-farbere@amazon.com
2024-12-11 20:32:34 +01:00
Paolo Bonzini
3154bddf8c KVM/arm64 fixes for 6.13, part #2
- Fix confusion with implicitly-shifted MDCR_EL2 masks breaking
    SPE/TRBE initialization
 
  - Align nested page table walker with the intended memory attribute
    combining rules of the architecture
 
  - Prevent userspace from constraining the advertised ASID width,
    avoiding horrors of guest TLBIs not matching the intended context in
    hardware
 
  - Don't leak references on LPIs when insertion into the translation
    cache fails
 -----BEGIN PGP SIGNATURE-----
 
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 =fLPh
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Merge tag 'kvmarm-fixes-6.13-2' of https://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm64 fixes for 6.13, part #2

 - Fix confusion with implicitly-shifted MDCR_EL2 masks breaking
   SPE/TRBE initialization

 - Align nested page table walker with the intended memory attribute
   combining rules of the architecture

 - Prevent userspace from constraining the advertised ASID width,
   avoiding horrors of guest TLBIs not matching the intended context in
   hardware

 - Don't leak references on LPIs when insertion into the translation
   cache fails
2024-12-10 08:50:55 -05:00
Hardevsinh Palaniya
e52163df77 arm64/cpufeature: Refactor conditional logic in init_cpu_ftr_reg()
Unnecessarily checks ftr_ovr == tmp in an extra else if, which is not
needed because that condition would already be true by default if the
previous conditions are not satisfied.

		if (ftr_ovr != tmp) {
		} else if (ftr_new != tmp) {
		} else if (ftr_ovr == tmp) {

Logic: The first and last conditions are inverses of each other, so
the last condition must be true if the first two conditions are false.

Additionally, all branches set the variable str, making the subsequent
"if (str)" check redundant

Reviewed-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Hardevsinh Palaniya <hardevsinh.palaniya@siliconsignals.io>
Link: https://lore.kernel.org/r/20241115053740.20523-1-hardevsinh.palaniya@siliconsignals.io
Signed-off-by: Will Deacon <will@kernel.org>
2024-12-10 12:16:19 +00:00
Mark Rutland
d60624f72d arm64: ptrace: fix partial SETREGSET for NT_ARM_GCS
Currently gcs_set() doesn't initialize the temporary 'user_gcs'
variable, and a SETREGSET call with a length of 0, 8, or 16 will leave
some portion of this uninitialized. Consequently some arbitrary
uninitialized values may be written back to the relevant fields in task
struct, potentially leaking up to 192 bits of memory from the kernel
stack. The read is limited to a specific slot on the stack, and the
issue does not provide a write mechanism.

As gcs_set() rejects cases where user_gcs::features_enabled has bits set
other than PR_SHADOW_STACK_SUPPORTED_STATUS_MASK, a SETREGSET call with
a length of zero will randomly succeed or fail depending on the value of
the uninitialized value, it isn't possible to leak the full 192 bits.
With a length of 8 or 16, user_gcs::features_enabled can be initialized
to an accepted value, making it practical to leak 128 or 64 bits.

Fix this by initializing the temporary value before copying the regset
from userspace, as for other regsets (e.g. NT_PRSTATUS, NT_PRFPREG,
NT_ARM_SYSTEM_CALL). In the case of a zero-length or partial write, the
existing contents of the fields which are not written to will be
retained.

To ensure that the extraction and insertion of fields is consistent
across the GETREGSET and SETREGSET calls, new task_gcs_to_user() and
task_gcs_from_user() helpers are added, matching the style of
pac_address_keys_to_user() and pac_address_keys_from_user().

Before this patch:

| # ./gcs-test
| Attempting to write NT_ARM_GCS::user_gcs = {
|     .features_enabled = 0x0000000000000000,
|     .features_locked  = 0x0000000000000000,
|     .gcspr_el0        = 0x900d900d900d900d,
| }
| SETREGSET(nt=0x410, len=24) wrote 24 bytes
|
| Attempting to read NT_ARM_GCS::user_gcs
| GETREGSET(nt=0x410, len=24) read 24 bytes
| Read NT_ARM_GCS::user_gcs = {
|     .features_enabled = 0x0000000000000000,
|     .features_locked  = 0x0000000000000000,
|     .gcspr_el0        = 0x900d900d900d900d,
| }
|
| Attempting partial write NT_ARM_GCS::user_gcs = {
|     .features_enabled = 0x0000000000000000,
|     .features_locked  = 0x1de7ec7edbadc0de,
|     .gcspr_el0        = 0x1de7ec7edbadc0de,
| }
| SETREGSET(nt=0x410, len=8) wrote 8 bytes
|
| Attempting to read NT_ARM_GCS::user_gcs
| GETREGSET(nt=0x410, len=24) read 24 bytes
| Read NT_ARM_GCS::user_gcs = {
|     .features_enabled = 0x0000000000000000,
|     .features_locked  = 0x000000000093e780,
|     .gcspr_el0        = 0xffff800083a63d50,
| }

After this patch:

| # ./gcs-test
| Attempting to write NT_ARM_GCS::user_gcs = {
|     .features_enabled = 0x0000000000000000,
|     .features_locked  = 0x0000000000000000,
|     .gcspr_el0        = 0x900d900d900d900d,
| }
| SETREGSET(nt=0x410, len=24) wrote 24 bytes
|
| Attempting to read NT_ARM_GCS::user_gcs
| GETREGSET(nt=0x410, len=24) read 24 bytes
| Read NT_ARM_GCS::user_gcs = {
|     .features_enabled = 0x0000000000000000,
|     .features_locked  = 0x0000000000000000,
|     .gcspr_el0        = 0x900d900d900d900d,
| }
|
| Attempting partial write NT_ARM_GCS::user_gcs = {
|     .features_enabled = 0x0000000000000000,
|     .features_locked  = 0x1de7ec7edbadc0de,
|     .gcspr_el0        = 0x1de7ec7edbadc0de,
| }
| SETREGSET(nt=0x410, len=8) wrote 8 bytes
|
| Attempting to read NT_ARM_GCS::user_gcs
| GETREGSET(nt=0x410, len=24) read 24 bytes
| Read NT_ARM_GCS::user_gcs = {
|     .features_enabled = 0x0000000000000000,
|     .features_locked  = 0x0000000000000000,
|     .gcspr_el0        = 0x900d900d900d900d,
| }

Fixes: 7ec3b57cb2 ("arm64/ptrace: Expose GCS via ptrace and core files")
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Will Deacon <will@kernel.org>
Reviewed-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20241205121655.1824269-5-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-12-05 18:05:51 +00:00
Mark Rutland
594bfc4947 arm64: ptrace: fix partial SETREGSET for NT_ARM_POE
Currently poe_set() doesn't initialize the temporary 'ctrl' variable,
and a SETREGSET call with a length of zero will leave this
uninitialized. Consequently an arbitrary value will be written back to
target->thread.por_el0, potentially leaking up to 64 bits of memory from
the kernel stack. The read is limited to a specific slot on the stack,
and the issue does not provide a write mechanism.

Fix this by initializing the temporary value before copying the regset
from userspace, as for other regsets (e.g. NT_PRSTATUS, NT_PRFPREG,
NT_ARM_SYSTEM_CALL). In the case of a zero-length write, the existing
contents of POR_EL1 will be retained.

Before this patch:

| # ./poe-test
| Attempting to write NT_ARM_POE::por_el0 = 0x900d900d900d900d
| SETREGSET(nt=0x40f, len=8) wrote 8 bytes
|
| Attempting to read NT_ARM_POE::por_el0
| GETREGSET(nt=0x40f, len=8) read 8 bytes
| Read NT_ARM_POE::por_el0 = 0x900d900d900d900d
|
| Attempting to write NT_ARM_POE (zero length)
| SETREGSET(nt=0x40f, len=0) wrote 0 bytes
|
| Attempting to read NT_ARM_POE::por_el0
| GETREGSET(nt=0x40f, len=8) read 8 bytes
| Read NT_ARM_POE::por_el0 = 0xffff8000839c3d50

After this patch:

| # ./poe-test
| Attempting to write NT_ARM_POE::por_el0 = 0x900d900d900d900d
| SETREGSET(nt=0x40f, len=8) wrote 8 bytes
|
| Attempting to read NT_ARM_POE::por_el0
| GETREGSET(nt=0x40f, len=8) read 8 bytes
| Read NT_ARM_POE::por_el0 = 0x900d900d900d900d
|
| Attempting to write NT_ARM_POE (zero length)
| SETREGSET(nt=0x40f, len=0) wrote 0 bytes
|
| Attempting to read NT_ARM_POE::por_el0
| GETREGSET(nt=0x40f, len=8) read 8 bytes
| Read NT_ARM_POE::por_el0 = 0x900d900d900d900d

Fixes: 1751981992 ("arm64/ptrace: add support for FEAT_POE")
Cc: <stable@vger.kernel.org> # 6.12.x
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Joey Gouly <joey.gouly@arm.com>
Cc: Will Deacon <will@kernel.org>
Reviewed-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20241205121655.1824269-4-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-12-05 18:05:33 +00:00
Mark Rutland
f5d7129184 arm64: ptrace: fix partial SETREGSET for NT_ARM_FPMR
Currently fpmr_set() doesn't initialize the temporary 'fpmr' variable,
and a SETREGSET call with a length of zero will leave this
uninitialized. Consequently an arbitrary value will be written back to
target->thread.uw.fpmr, potentially leaking up to 64 bits of memory from
the kernel stack. The read is limited to a specific slot on the stack,
and the issue does not provide a write mechanism.

Fix this by initializing the temporary value before copying the regset
from userspace, as for other regsets (e.g. NT_PRSTATUS, NT_PRFPREG,
NT_ARM_SYSTEM_CALL). In the case of a zero-length write, the existing
contents of FPMR will be retained.

Before this patch:

| # ./fpmr-test
| Attempting to write NT_ARM_FPMR::fpmr = 0x900d900d900d900d
| SETREGSET(nt=0x40e, len=8) wrote 8 bytes
|
| Attempting to read NT_ARM_FPMR::fpmr
| GETREGSET(nt=0x40e, len=8) read 8 bytes
| Read NT_ARM_FPMR::fpmr = 0x900d900d900d900d
|
| Attempting to write NT_ARM_FPMR (zero length)
| SETREGSET(nt=0x40e, len=0) wrote 0 bytes
|
| Attempting to read NT_ARM_FPMR::fpmr
| GETREGSET(nt=0x40e, len=8) read 8 bytes
| Read NT_ARM_FPMR::fpmr = 0xffff800083963d50

After this patch:

| # ./fpmr-test
| Attempting to write NT_ARM_FPMR::fpmr = 0x900d900d900d900d
| SETREGSET(nt=0x40e, len=8) wrote 8 bytes
|
| Attempting to read NT_ARM_FPMR::fpmr
| GETREGSET(nt=0x40e, len=8) read 8 bytes
| Read NT_ARM_FPMR::fpmr = 0x900d900d900d900d
|
| Attempting to write NT_ARM_FPMR (zero length)
| SETREGSET(nt=0x40e, len=0) wrote 0 bytes
|
| Attempting to read NT_ARM_FPMR::fpmr
| GETREGSET(nt=0x40e, len=8) read 8 bytes
| Read NT_ARM_FPMR::fpmr = 0x900d900d900d900d

Fixes: 4035c22ef7 ("arm64/ptrace: Expose FPMR via ptrace")
Cc: <stable@vger.kernel.org> # 6.9.x
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Will Deacon <will@kernel.org>
Reviewed-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20241205121655.1824269-3-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-12-05 18:04:06 +00:00
Mark Rutland
ca62d90085 arm64: ptrace: fix partial SETREGSET for NT_ARM_TAGGED_ADDR_CTRL
Currently tagged_addr_ctrl_set() doesn't initialize the temporary 'ctrl'
variable, and a SETREGSET call with a length of zero will leave this
uninitialized. Consequently tagged_addr_ctrl_set() will consume an
arbitrary value, potentially leaking up to 64 bits of memory from the
kernel stack. The read is limited to a specific slot on the stack, and
the issue does not provide a write mechanism.

As set_tagged_addr_ctrl() only accepts values where bits [63:4] zero and
rejects other values, a partial SETREGSET attempt will randomly succeed
or fail depending on the value of the uninitialized value, and the
exposure is significantly limited.

Fix this by initializing the temporary value before copying the regset
from userspace, as for other regsets (e.g. NT_PRSTATUS, NT_PRFPREG,
NT_ARM_SYSTEM_CALL). In the case of a zero-length write, the existing
value of the tagged address ctrl will be retained.

The NT_ARM_TAGGED_ADDR_CTRL regset is only visible in the
user_aarch64_view used by a native AArch64 task to manipulate another
native AArch64 task. As get_tagged_addr_ctrl() only returns an error
value when called for a compat task, tagged_addr_ctrl_get() and
tagged_addr_ctrl_set() should never observe an error value from
get_tagged_addr_ctrl(). Add a WARN_ON_ONCE() to both to indicate that
such an error would be unexpected, and error handlnig is not missing in
either case.

Fixes: 2200aa7154 ("arm64: mte: ptrace: Add NT_ARM_TAGGED_ADDR_CTRL regset")
Cc: <stable@vger.kernel.org> # 5.10.x
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will@kernel.org>
Reviewed-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20241205121655.1824269-2-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-12-05 18:03:25 +00:00
Mark Rutland
8d09e2d569 arm64: patching: avoid early page_to_phys()
When arm64 is configured with CONFIG_DEBUG_VIRTUAL=y, a warning is
printed from the patching code because patch_map(), e.g.

| ------------[ cut here ]------------
| WARNING: CPU: 0 PID: 0 at arch/arm64/kernel/patching.c:45 patch_map.constprop.0+0x120/0xd00
| CPU: 0 UID: 0 PID: 0 Comm: swapper Not tainted 6.13.0-rc1-00002-ge1a5d6c6be55 #1
| Hardware name: linux,dummy-virt (DT)
| pstate: 800003c5 (Nzcv DAIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
| pc : patch_map.constprop.0+0x120/0xd00
| lr : patch_map.constprop.0+0x120/0xd00
| sp : ffffa9bb312a79a0
| x29: ffffa9bb312a79a0 x28: 0000000000000001 x27: 0000000000000001
| x26: 0000000000000000 x25: 0000000000000000 x24: 00000000000402e8
| x23: ffffa9bb2c94c1c8 x22: ffffa9bb2c94c000 x21: ffffa9bb222e883c
| x20: 0000000000000002 x19: ffffc1ffc100ba40 x18: ffffa9bb2cf0f21c
| x17: 0000000000000006 x16: 0000000000000000 x15: 0000000000000004
| x14: 1ffff5376625b4ac x13: ffff753766a67fb8 x12: ffff753766919cd1
| x11: 0000000000000003 x10: 1ffff5376625b4c3 x9 : 1ffff5376625b4af
| x8 : ffff753766254f0a x7 : 0000000041b58ab3 x6 : ffff753766254f18
| x5 : ffffa9bb312d9bc0 x4 : 0000000000000000 x3 : ffffa9bb29bd90e4
| x2 : 0000000000000002 x1 : ffffa9bb312d9bc0 x0 : 0000000000000000
| Call trace:
|  patch_map.constprop.0+0x120/0xd00 (P)
|  patch_map.constprop.0+0x120/0xd00 (L)
|  __aarch64_insn_write+0xa8/0x120
|  aarch64_insn_patch_text_nosync+0x4c/0xb8
|  arch_jump_label_transform_queue+0x7c/0x100
|  jump_label_update+0x154/0x460
|  static_key_enable_cpuslocked+0x1d8/0x280
|  static_key_enable+0x2c/0x48
|  early_randomize_kstack_offset+0x104/0x168
|  do_early_param+0xe4/0x148
|  parse_args+0x3a4/0x838
|  parse_early_options+0x50/0x68
|  parse_early_param+0x58/0xe0
|  setup_arch+0x78/0x1f0
|  start_kernel+0xa0/0x530
|  __primary_switched+0x8c/0xa0
| irq event stamp: 0
| hardirqs last  enabled at (0): [<0000000000000000>] 0x0
| hardirqs last disabled at (0): [<0000000000000000>] 0x0
| softirqs last  enabled at (0): [<0000000000000000>] 0x0
| softirqs last disabled at (0): [<0000000000000000>] 0x0
| ---[ end trace 0000000000000000 ]---

The warning has been produced since commit:

  3e25d5a49f ("asm-generic: add an optional pfn_valid check to page_to_phys")

... which added a pfn_valid() check into page_to_phys(), and at this
point in boot pfn_valid() will always return false because the vmemmap
has not yet been initialized and there are no valid mem_sections yet.

Before that commit, the arithmetic performed by page_to_phys() would
give the expected physical address, though it is somewhat dubious to use
vmemmap addresses before the vmemmap has been initialized.

Aside from kernel image addresses, all executable code should be
allocated from execmem (where all allocations will fall within the
vmalloc area), and so there's no need for the fallback case when
CONFIG_EXECMEM=n.

Simplify patch_map() accordingly, directly converting kernel image
addresses and removing the redundant fallback case.

Fixes: 3e25d5a49f ("asm-generic: add an optional pfn_valid check to page_to_phys")
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Thomas Huth <thuth@redhat.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20241202170359.1475019-1-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-12-03 18:05:42 +00:00
James Clark
d798bc6f3c arm64: Fix usage of new shifted MDCR_EL2 values
Since the linked fixes commit, these masks are already shifted so remove
the shifts. One issue that this fixes is SPE and TRBE not being
available anymore:

 arm_spe_pmu arm,spe-v1: profiling buffer owned by higher exception level

Fixes: 641630313e ("arm64: sysreg: Migrate MDCR_EL2 definition to table")
Signed-off-by: James Clark <james.clark@linaro.org>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20241122164636.2944180-1-james.clark@linaro.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-11-26 06:31:36 -08:00
Linus Torvalds
9f16d5e6f2 The biggest change here is eliminating the awful idea that KVM had, of
essentially guessing which pfns are refcounted pages.  The reason to
 do so was that KVM needs to map both non-refcounted pages (for example
 BARs of VFIO devices) and VM_PFNMAP/VM_MIXMEDMAP VMAs that contain
 refcounted pages.  However, the result was security issues in the past,
 and more recently the inability to map VM_IO and VM_PFNMAP memory
 that _is_ backed by struct page but is not refcounted.  In particular
 this broke virtio-gpu blob resources (which directly map host graphics
 buffers into the guest as "vram" for the virtio-gpu device) with the
 amdgpu driver, because amdgpu allocates non-compound higher order pages
 and the tail pages could not be mapped into KVM.
 
 This requires adjusting all uses of struct page in the per-architecture
 code, to always work on the pfn whenever possible.  The large series that
 did this, from David Stevens and Sean Christopherson, also cleaned up
 substantially the set of functions that provided arch code with the
 pfn for a host virtual addresses.  The previous maze of twisty little
 passages, all different, is replaced by five functions (__gfn_to_page,
 __kvm_faultin_pfn, the non-__ versions of these two, and kvm_prefetch_pages)
 saving almost 200 lines of code.
 
 ARM:
 
 * Support for stage-1 permission indirection (FEAT_S1PIE) and
   permission overlays (FEAT_S1POE), including nested virt + the
   emulated page table walker
 
 * Introduce PSCI SYSTEM_OFF2 support to KVM + client driver. This call
   was introduced in PSCIv1.3 as a mechanism to request hibernation,
   similar to the S4 state in ACPI
 
 * Explicitly trap + hide FEAT_MPAM (QoS controls) from KVM guests. As
   part of it, introduce trivial initialization of the host's MPAM
   context so KVM can use the corresponding traps
 
 * PMU support under nested virtualization, honoring the guest
   hypervisor's trap configuration and event filtering when running a
   nested guest
 
 * Fixes to vgic ITS serialization where stale device/interrupt table
   entries are not zeroed when the mapping is invalidated by the VM
 
 * Avoid emulated MMIO completion if userspace has requested synchronous
   external abort injection
 
 * Various fixes and cleanups affecting pKVM, vCPU initialization, and
   selftests
 
 LoongArch:
 
 * Add iocsr and mmio bus simulation in kernel.
 
 * Add in-kernel interrupt controller emulation.
 
 * Add support for virtualization extensions to the eiointc irqchip.
 
 PPC:
 
 * Drop lingering and utterly obsolete references to PPC970 KVM, which was
   removed 10 years ago.
 
 * Fix incorrect documentation references to non-existing ioctls
 
 RISC-V:
 
 * Accelerate KVM RISC-V when running as a guest
 
 * Perf support to collect KVM guest statistics from host side
 
 s390:
 
 * New selftests: more ucontrol selftests and CPU model sanity checks
 
 * Support for the gen17 CPU model
 
 * List registers supported by KVM_GET/SET_ONE_REG in the documentation
 
 x86:
 
 * Cleanup KVM's handling of Accessed and Dirty bits to dedup code, improve
   documentation, harden against unexpected changes.  Even if the hardware
   A/D tracking is disabled, it is possible to use the hardware-defined A/D
   bits to track if a PFN is Accessed and/or Dirty, and that removes a lot
   of special cases.
 
 * Elide TLB flushes when aging secondary PTEs, as has been done in x86's
   primary MMU for over 10 years.
 
 * Recover huge pages in-place in the TDP MMU when dirty page logging is
   toggled off, instead of zapping them and waiting until the page is
   re-accessed to create a huge mapping.  This reduces vCPU jitter.
 
 * Batch TLB flushes when dirty page logging is toggled off.  This reduces
   the time it takes to disable dirty logging by ~3x.
 
 * Remove the shrinker that was (poorly) attempting to reclaim shadow page
   tables in low-memory situations.
 
 * Clean up and optimize KVM's handling of writes to MSR_IA32_APICBASE.
 
 * Advertise CPUIDs for new instructions in Clearwater Forest
 
 * Quirk KVM's misguided behavior of initialized certain feature MSRs to
   their maximum supported feature set, which can result in KVM creating
   invalid vCPU state.  E.g. initializing PERF_CAPABILITIES to a non-zero
   value results in the vCPU having invalid state if userspace hides PDCM
   from the guest, which in turn can lead to save/restore failures.
 
 * Fix KVM's handling of non-canonical checks for vCPUs that support LA57
   to better follow the "architecture", in quotes because the actual
   behavior is poorly documented.  E.g. most MSR writes and descriptor
   table loads ignore CR4.LA57 and operate purely on whether the CPU
   supports LA57.
 
 * Bypass the register cache when querying CPL from kvm_sched_out(), as
   filling the cache from IRQ context is generally unsafe; harden the
   cache accessors to try to prevent similar issues from occuring in the
   future.  The issue that triggered this change was already fixed in 6.12,
   but was still kinda latent.
 
 * Advertise AMD_IBPB_RET to userspace, and fix a related bug where KVM
   over-advertises SPEC_CTRL when trying to support cross-vendor VMs.
 
 * Minor cleanups
 
 * Switch hugepage recovery thread to use vhost_task.  These kthreads can
   consume significant amounts of CPU time on behalf of a VM or in response
   to how the VM behaves (for example how it accesses its memory); therefore
   KVM tried to place the thread in the VM's cgroups and charge the CPU
   time consumed by that work to the VM's container.  However the kthreads
   did not process SIGSTOP/SIGCONT, and therefore cgroups which had KVM
   instances inside could not complete freezing.  Fix this by replacing the
   kthread with a PF_USER_WORKER thread, via the vhost_task abstraction.
   Another 100+ lines removed, with generally better behavior too like
   having these threads properly parented in the process tree.
 
 * Revert a workaround for an old CPU erratum (Nehalem/Westmere) that didn't
   really work; there was really nothing to work around anyway: the broken
   patch was meant to fix nested virtualization, but the PERF_GLOBAL_CTRL
   MSR is virtualized and therefore unaffected by the erratum.
 
 * Fix 6.12 regression where CONFIG_KVM will be built as a module even
   if asked to be builtin, as long as neither KVM_INTEL nor KVM_AMD is 'y'.
 
 x86 selftests:
 
 * x86 selftests can now use AVX.
 
 Documentation:
 
 * Use rST internal links
 
 * Reorganize the introduction to the API document
 
 Generic:
 
 * Protect vcpu->pid accesses outside of vcpu->mutex with a rwlock instead
   of RCU, so that running a vCPU on a different task doesn't encounter long
   due to having to wait for all CPUs become quiescent.  In general both reads
   and writes are rare, but userspace that supports confidential computing is
   introducing the use of "helper" vCPUs that may jump from one host processor
   to another.  Those will be very happy to trigger a synchronize_rcu(), and
   the effect on performance is quite the disaster.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull kvm updates from Paolo Bonzini:
 "The biggest change here is eliminating the awful idea that KVM had of
  essentially guessing which pfns are refcounted pages.

  The reason to do so was that KVM needs to map both non-refcounted
  pages (for example BARs of VFIO devices) and VM_PFNMAP/VM_MIXMEDMAP
  VMAs that contain refcounted pages.

  However, the result was security issues in the past, and more recently
  the inability to map VM_IO and VM_PFNMAP memory that _is_ backed by
  struct page but is not refcounted. In particular this broke virtio-gpu
  blob resources (which directly map host graphics buffers into the
  guest as "vram" for the virtio-gpu device) with the amdgpu driver,
  because amdgpu allocates non-compound higher order pages and the tail
  pages could not be mapped into KVM.

  This requires adjusting all uses of struct page in the
  per-architecture code, to always work on the pfn whenever possible.
  The large series that did this, from David Stevens and Sean
  Christopherson, also cleaned up substantially the set of functions
  that provided arch code with the pfn for a host virtual addresses.

  The previous maze of twisty little passages, all different, is
  replaced by five functions (__gfn_to_page, __kvm_faultin_pfn, the
  non-__ versions of these two, and kvm_prefetch_pages) saving almost
  200 lines of code.

  ARM:

   - Support for stage-1 permission indirection (FEAT_S1PIE) and
     permission overlays (FEAT_S1POE), including nested virt + the
     emulated page table walker

   - Introduce PSCI SYSTEM_OFF2 support to KVM + client driver. This
     call was introduced in PSCIv1.3 as a mechanism to request
     hibernation, similar to the S4 state in ACPI

   - Explicitly trap + hide FEAT_MPAM (QoS controls) from KVM guests. As
     part of it, introduce trivial initialization of the host's MPAM
     context so KVM can use the corresponding traps

   - PMU support under nested virtualization, honoring the guest
     hypervisor's trap configuration and event filtering when running a
     nested guest

   - Fixes to vgic ITS serialization where stale device/interrupt table
     entries are not zeroed when the mapping is invalidated by the VM

   - Avoid emulated MMIO completion if userspace has requested
     synchronous external abort injection

   - Various fixes and cleanups affecting pKVM, vCPU initialization, and
     selftests

  LoongArch:

   - Add iocsr and mmio bus simulation in kernel.

   - Add in-kernel interrupt controller emulation.

   - Add support for virtualization extensions to the eiointc irqchip.

  PPC:

   - Drop lingering and utterly obsolete references to PPC970 KVM, which
     was removed 10 years ago.

   - Fix incorrect documentation references to non-existing ioctls

  RISC-V:

   - Accelerate KVM RISC-V when running as a guest

   - Perf support to collect KVM guest statistics from host side

  s390:

   - New selftests: more ucontrol selftests and CPU model sanity checks

   - Support for the gen17 CPU model

   - List registers supported by KVM_GET/SET_ONE_REG in the
     documentation

  x86:

   - Cleanup KVM's handling of Accessed and Dirty bits to dedup code,
     improve documentation, harden against unexpected changes.

     Even if the hardware A/D tracking is disabled, it is possible to
     use the hardware-defined A/D bits to track if a PFN is Accessed
     and/or Dirty, and that removes a lot of special cases.

   - Elide TLB flushes when aging secondary PTEs, as has been done in
     x86's primary MMU for over 10 years.

   - Recover huge pages in-place in the TDP MMU when dirty page logging
     is toggled off, instead of zapping them and waiting until the page
     is re-accessed to create a huge mapping. This reduces vCPU jitter.

   - Batch TLB flushes when dirty page logging is toggled off. This
     reduces the time it takes to disable dirty logging by ~3x.

   - Remove the shrinker that was (poorly) attempting to reclaim shadow
     page tables in low-memory situations.

   - Clean up and optimize KVM's handling of writes to
     MSR_IA32_APICBASE.

   - Advertise CPUIDs for new instructions in Clearwater Forest

   - Quirk KVM's misguided behavior of initialized certain feature MSRs
     to their maximum supported feature set, which can result in KVM
     creating invalid vCPU state. E.g. initializing PERF_CAPABILITIES to
     a non-zero value results in the vCPU having invalid state if
     userspace hides PDCM from the guest, which in turn can lead to
     save/restore failures.

   - Fix KVM's handling of non-canonical checks for vCPUs that support
     LA57 to better follow the "architecture", in quotes because the
     actual behavior is poorly documented. E.g. most MSR writes and
     descriptor table loads ignore CR4.LA57 and operate purely on
     whether the CPU supports LA57.

   - Bypass the register cache when querying CPL from kvm_sched_out(),
     as filling the cache from IRQ context is generally unsafe; harden
     the cache accessors to try to prevent similar issues from occuring
     in the future. The issue that triggered this change was already
     fixed in 6.12, but was still kinda latent.

   - Advertise AMD_IBPB_RET to userspace, and fix a related bug where
     KVM over-advertises SPEC_CTRL when trying to support cross-vendor
     VMs.

   - Minor cleanups

   - Switch hugepage recovery thread to use vhost_task.

     These kthreads can consume significant amounts of CPU time on
     behalf of a VM or in response to how the VM behaves (for example
     how it accesses its memory); therefore KVM tried to place the
     thread in the VM's cgroups and charge the CPU time consumed by that
     work to the VM's container.

     However the kthreads did not process SIGSTOP/SIGCONT, and therefore
     cgroups which had KVM instances inside could not complete freezing.

     Fix this by replacing the kthread with a PF_USER_WORKER thread, via
     the vhost_task abstraction. Another 100+ lines removed, with
     generally better behavior too like having these threads properly
     parented in the process tree.

   - Revert a workaround for an old CPU erratum (Nehalem/Westmere) that
     didn't really work; there was really nothing to work around anyway:
     the broken patch was meant to fix nested virtualization, but the
     PERF_GLOBAL_CTRL MSR is virtualized and therefore unaffected by the
     erratum.

   - Fix 6.12 regression where CONFIG_KVM will be built as a module even
     if asked to be builtin, as long as neither KVM_INTEL nor KVM_AMD is
     'y'.

  x86 selftests:

   - x86 selftests can now use AVX.

  Documentation:

   - Use rST internal links

   - Reorganize the introduction to the API document

  Generic:

   - Protect vcpu->pid accesses outside of vcpu->mutex with a rwlock
     instead of RCU, so that running a vCPU on a different task doesn't
     encounter long due to having to wait for all CPUs become quiescent.

     In general both reads and writes are rare, but userspace that
     supports confidential computing is introducing the use of "helper"
     vCPUs that may jump from one host processor to another. Those will
     be very happy to trigger a synchronize_rcu(), and the effect on
     performance is quite the disaster"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (298 commits)
  KVM: x86: Break CONFIG_KVM_X86's direct dependency on KVM_INTEL || KVM_AMD
  KVM: x86: add back X86_LOCAL_APIC dependency
  Revert "KVM: VMX: Move LOAD_IA32_PERF_GLOBAL_CTRL errata handling out of setup_vmcs_config()"
  KVM: x86: switch hugepage recovery thread to vhost_task
  KVM: x86: expose MSR_PLATFORM_INFO as a feature MSR
  x86: KVM: Advertise CPUIDs for new instructions in Clearwater Forest
  Documentation: KVM: fix malformed table
  irqchip/loongson-eiointc: Add virt extension support
  LoongArch: KVM: Add irqfd support
  LoongArch: KVM: Add PCHPIC user mode read and write functions
  LoongArch: KVM: Add PCHPIC read and write functions
  LoongArch: KVM: Add PCHPIC device support
  LoongArch: KVM: Add EIOINTC user mode read and write functions
  LoongArch: KVM: Add EIOINTC read and write functions
  LoongArch: KVM: Add EIOINTC device support
  LoongArch: KVM: Add IPI user mode read and write function
  LoongArch: KVM: Add IPI read and write function
  LoongArch: KVM: Add IPI device support
  LoongArch: KVM: Add iocsr and mmio bus simulation in kernel
  KVM: arm64: Pass on SVE mapping failures
  ...
2024-11-23 16:00:50 -08:00
Linus Torvalds
5c00ff742b - The series "zram: optimal post-processing target selection" from
Sergey Senozhatsky improves zram's post-processing selection algorithm.
   This leads to improved memory savings.
 
 - Wei Yang has gone to town on the mapletree code, contributing several
   series which clean up the implementation:
 
 	- "refine mas_mab_cp()"
 	- "Reduce the space to be cleared for maple_big_node"
 	- "maple_tree: simplify mas_push_node()"
 	- "Following cleanup after introduce mas_wr_store_type()"
 	- "refine storing null"
 
 - The series "selftests/mm: hugetlb_fault_after_madv improvements" from
   David Hildenbrand fixes this selftest for s390.
 
 - The series "introduce pte_offset_map_{ro|rw}_nolock()" from Qi Zheng
   implements some rationaizations and cleanups in the page mapping code.
 
 - The series "mm: optimize shadow entries removal" from Shakeel Butt
   optimizes the file truncation code by speeding up the handling of shadow
   entries.
 
 - The series "Remove PageKsm()" from Matthew Wilcox completes the
   migration of this flag over to being a folio-based flag.
 
 - The series "Unify hugetlb into arch_get_unmapped_area functions" from
   Oscar Salvador implements a bunch of consolidations and cleanups in the
   hugetlb code.
 
 - The series "Do not shatter hugezeropage on wp-fault" from Dev Jain
   takes away the wp-fault time practice of turning a huge zero page into
   small pages.  Instead we replace the whole thing with a THP.  More
   consistent cleaner and potentiall saves a large number of pagefaults.
 
 - The series "percpu: Add a test case and fix for clang" from Andy
   Shevchenko enhances and fixes the kernel's built in percpu test code.
 
 - The series "mm/mremap: Remove extra vma tree walk" from Liam Howlett
   optimizes mremap() by avoiding doing things which we didn't need to do.
 
 - The series "Improve the tmpfs large folio read performance" from
   Baolin Wang teaches tmpfs to copy data into userspace at the folio size
   rather than as individual pages.  A 20% speedup was observed.
 
 - The series "mm/damon/vaddr: Fix issue in
   damon_va_evenly_split_region()" fro Zheng Yejian fixes DAMON splitting.
 
 - The series "memcg-v1: fully deprecate charge moving" from Shakeel Butt
   removes the long-deprecated memcgv2 charge moving feature.
 
 - The series "fix error handling in mmap_region() and refactor" from
   Lorenzo Stoakes cleanup up some of the mmap() error handling and
   addresses some potential performance issues.
 
 - The series "x86/module: use large ROX pages for text allocations" from
   Mike Rapoport teaches x86 to use large pages for read-only-execute
   module text.
 
 - The series "page allocation tag compression" from Suren Baghdasaryan
   is followon maintenance work for the new page allocation profiling
   feature.
 
 - The series "page->index removals in mm" from Matthew Wilcox remove
   most references to page->index in mm/.  A slow march towards shrinking
   struct page.
 
 - The series "damon/{self,kunit}tests: minor fixups for DAMON debugfs
   interface tests" from Andrew Paniakin performs maintenance work for
   DAMON's self testing code.
 
 - The series "mm: zswap swap-out of large folios" from Kanchana Sridhar
   improves zswap's batching of compression and decompression.  It is a
   step along the way towards using Intel IAA hardware acceleration for
   this zswap operation.
 
 - The series "kasan: migrate the last module test to kunit" from
   Sabyrzhan Tasbolatov completes the migration of the KASAN built-in tests
   over to the KUnit framework.
 
 - The series "implement lightweight guard pages" from Lorenzo Stoakes
   permits userapace to place fault-generating guard pages within a single
   VMA, rather than requiring that multiple VMAs be created for this.
   Improved efficiencies for userspace memory allocators are expected.
 
 - The series "memcg: tracepoint for flushing stats" from JP Kobryn uses
   tracepoints to provide increased visibility into memcg stats flushing
   activity.
 
 - The series "zram: IDLE flag handling fixes" from Sergey Senozhatsky
   fixes a zram buglet which potentially affected performance.
 
 - The series "mm: add more kernel parameters to control mTHP" from
   Maíra Canal enhances our ability to control/configuremultisize THP from
   the kernel boot command line.
 
 - The series "kasan: few improvements on kunit tests" from Sabyrzhan
   Tasbolatov has a couple of fixups for the KASAN KUnit tests.
 
 - The series "mm/list_lru: Split list_lru lock into per-cgroup scope"
   from Kairui Song optimizes list_lru memory utilization when lockdep is
   enabled.
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Merge tag 'mm-stable-2024-11-18-19-27' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:

 - The series "zram: optimal post-processing target selection" from
   Sergey Senozhatsky improves zram's post-processing selection
   algorithm. This leads to improved memory savings.

 - Wei Yang has gone to town on the mapletree code, contributing several
   series which clean up the implementation:
	- "refine mas_mab_cp()"
	- "Reduce the space to be cleared for maple_big_node"
	- "maple_tree: simplify mas_push_node()"
	- "Following cleanup after introduce mas_wr_store_type()"
	- "refine storing null"

 - The series "selftests/mm: hugetlb_fault_after_madv improvements" from
   David Hildenbrand fixes this selftest for s390.

 - The series "introduce pte_offset_map_{ro|rw}_nolock()" from Qi Zheng
   implements some rationaizations and cleanups in the page mapping
   code.

 - The series "mm: optimize shadow entries removal" from Shakeel Butt
   optimizes the file truncation code by speeding up the handling of
   shadow entries.

 - The series "Remove PageKsm()" from Matthew Wilcox completes the
   migration of this flag over to being a folio-based flag.

 - The series "Unify hugetlb into arch_get_unmapped_area functions" from
   Oscar Salvador implements a bunch of consolidations and cleanups in
   the hugetlb code.

 - The series "Do not shatter hugezeropage on wp-fault" from Dev Jain
   takes away the wp-fault time practice of turning a huge zero page
   into small pages. Instead we replace the whole thing with a THP. More
   consistent cleaner and potentiall saves a large number of pagefaults.

 - The series "percpu: Add a test case and fix for clang" from Andy
   Shevchenko enhances and fixes the kernel's built in percpu test code.

 - The series "mm/mremap: Remove extra vma tree walk" from Liam Howlett
   optimizes mremap() by avoiding doing things which we didn't need to
   do.

 - The series "Improve the tmpfs large folio read performance" from
   Baolin Wang teaches tmpfs to copy data into userspace at the folio
   size rather than as individual pages. A 20% speedup was observed.

 - The series "mm/damon/vaddr: Fix issue in
   damon_va_evenly_split_region()" fro Zheng Yejian fixes DAMON
   splitting.

 - The series "memcg-v1: fully deprecate charge moving" from Shakeel
   Butt removes the long-deprecated memcgv2 charge moving feature.

 - The series "fix error handling in mmap_region() and refactor" from
   Lorenzo Stoakes cleanup up some of the mmap() error handling and
   addresses some potential performance issues.

 - The series "x86/module: use large ROX pages for text allocations"
   from Mike Rapoport teaches x86 to use large pages for
   read-only-execute module text.

 - The series "page allocation tag compression" from Suren Baghdasaryan
   is followon maintenance work for the new page allocation profiling
   feature.

 - The series "page->index removals in mm" from Matthew Wilcox remove
   most references to page->index in mm/. A slow march towards shrinking
   struct page.

 - The series "damon/{self,kunit}tests: minor fixups for DAMON debugfs
   interface tests" from Andrew Paniakin performs maintenance work for
   DAMON's self testing code.

 - The series "mm: zswap swap-out of large folios" from Kanchana Sridhar
   improves zswap's batching of compression and decompression. It is a
   step along the way towards using Intel IAA hardware acceleration for
   this zswap operation.

 - The series "kasan: migrate the last module test to kunit" from
   Sabyrzhan Tasbolatov completes the migration of the KASAN built-in
   tests over to the KUnit framework.

 - The series "implement lightweight guard pages" from Lorenzo Stoakes
   permits userapace to place fault-generating guard pages within a
   single VMA, rather than requiring that multiple VMAs be created for
   this. Improved efficiencies for userspace memory allocators are
   expected.

 - The series "memcg: tracepoint for flushing stats" from JP Kobryn uses
   tracepoints to provide increased visibility into memcg stats flushing
   activity.

 - The series "zram: IDLE flag handling fixes" from Sergey Senozhatsky
   fixes a zram buglet which potentially affected performance.

 - The series "mm: add more kernel parameters to control mTHP" from
   Maíra Canal enhances our ability to control/configuremultisize THP
   from the kernel boot command line.

 - The series "kasan: few improvements on kunit tests" from Sabyrzhan
   Tasbolatov has a couple of fixups for the KASAN KUnit tests.

 - The series "mm/list_lru: Split list_lru lock into per-cgroup scope"
   from Kairui Song optimizes list_lru memory utilization when lockdep
   is enabled.

* tag 'mm-stable-2024-11-18-19-27' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (215 commits)
  cma: enforce non-zero pageblock_order during cma_init_reserved_mem()
  mm/kfence: add a new kunit test test_use_after_free_read_nofault()
  zram: fix NULL pointer in comp_algorithm_show()
  memcg/hugetlb: add hugeTLB counters to memcg
  vmstat: call fold_vm_zone_numa_events() before show per zone NUMA event
  mm: mmap_lock: check trace_mmap_lock_$type_enabled() instead of regcount
  zram: ZRAM_DEF_COMP should depend on ZRAM
  MAINTAINERS/MEMORY MANAGEMENT: add document files for mm
  Docs/mm/damon: recommend academic papers to read and/or cite
  mm: define general function pXd_init()
  kmemleak: iommu/iova: fix transient kmemleak false positive
  mm/list_lru: simplify the list_lru walk callback function
  mm/list_lru: split the lock to per-cgroup scope
  mm/list_lru: simplify reparenting and initial allocation
  mm/list_lru: code clean up for reparenting
  mm/list_lru: don't export list_lru_add
  mm/list_lru: don't pass unnecessary key parameters
  kasan: add kunit tests for kmalloc_track_caller, kmalloc_node_track_caller
  kasan: change kasan_atomics kunit test as KUNIT_CASE_SLOW
  kasan: use EXPORT_SYMBOL_IF_KUNIT to export symbols
  ...
2024-11-23 09:58:07 -08:00
Linus Torvalds
79caa6c88a asm-generic updates for 6.13
These are a number of unrelated cleanups, generally simplifying the
 architecture specific header files:
 
  - A series from Al Viro simplifies asm/vga.h, after it turns out that
    most of it can be generalized.
 
  - A series from Julian Vetter adds a common version of
    memcpy_{to,from}io() and memset_io() and changes most architectures
    to use that instead of their own implementation
 
  - A series from Niklas Schnelle concludes his work to make PC
    style inb()/outb() optional
 
  - Nicolas Pitre contributes improvements for the generic do_div()
    helper
 
  - Christoph Hellwig adds a generic version of page_to_phys()
    and phys_to_page(), replacing the slightly different architecture
    specific definitions.
 
  - Uwe Kleine-Koenig has a minor cleanup for ioctl definitions
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Merge tag 'asm-generic-3.13' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic

Pull asm-generic updates from Arnd Bergmann:
 "These are a number of unrelated cleanups, generally simplifying the
  architecture specific header files:

   - A series from Al Viro simplifies asm/vga.h, after it turns out that
     most of it can be generalized.

   - A series from Julian Vetter adds a common version of
     memcpy_{to,from}io() and memset_io() and changes most architectures
     to use that instead of their own implementation

   - A series from Niklas Schnelle concludes his work to make PC style
     inb()/outb() optional

   - Nicolas Pitre contributes improvements for the generic do_div()
     helper

   - Christoph Hellwig adds a generic version of page_to_phys() and
     phys_to_page(), replacing the slightly different architecture
     specific definitions.

   - Uwe Kleine-Koenig has a minor cleanup for ioctl definitions"

* tag 'asm-generic-3.13' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic: (24 commits)
  empty include/asm-generic/vga.h
  sparc: get rid of asm/vga.h
  asm/vga.h: don't bother with scr_mem{cpy,move}v() unless we need to
  vt_buffer.h: get rid of dead code in default scr_...() instances
  tty: serial: export serial_8250_warn_need_ioport
  lib/iomem_copy: fix kerneldoc format style
  hexagon: simplify asm/io.h for !HAS_IOPORT
  loongarch: Use new fallback IO memcpy/memset
  csky: Use new fallback IO memcpy/memset
  arm64: Use new fallback IO memcpy/memset
  New implementation for IO memcpy and IO memset
  watchdog: Add HAS_IOPORT dependency for SBC8360 and SBC7240
  __arch_xprod64(): make __always_inline when optimizing for performance
  ARM: div64: improve __arch_xprod_64()
  asm-generic/div64: optimize/simplify __div64_const32()
  lib/math/test_div64: add some edge cases relevant to __div64_const32()
  asm-generic: add an optional pfn_valid check to page_to_phys
  asm-generic: provide generic page_to_phys and phys_to_page implementations
  asm-generic/io.h: Remove I/O port accessors for HAS_IOPORT=n
  tty: serial: handle HAS_IOPORT dependencies
  ...
2024-11-20 15:13:02 -08:00
Linus Torvalds
e6de688e93 Devicetree updates for v6.13:
Bindings:
 
 - Enable dtc "interrupt_provider" warnings for binding examples.
   Fix the warnings in fsl,mu-msi and ti,sci-inta due to this.
 
 - Convert zii,rave-sp-wdt, zii,rave-sp-pwrbutton,  and
   altr,fpga-passive-serial to DT schema format
 
 - Add some documentation on the different forms of YAML text blocks
   which are a constant source of review comments
 
 - Fix some schema errors in constraints for arrays
 
 - Add compatibles for qcom,sar2130p-pdc and onnn,adt7462
 
 DT core:
 
 - Allow overlay kunit tests to run CONFIG_OF_OVERLAY=n
 
 - Add some warnings on deprecated address handling
 
 - Rework early_init_dt_scan() so the arch can pass in the phys address
   of the DTB as __pa() is not always valid to use. This fixes a warning
   for arm64 with kexec.
 
 - Add and use some new DT graph iterators for iterating over ports and
   endpoints
 
 - Rework reserved-memory handling to be sized dynamically for fixed
   regions
 
 - Optimize of_modalias() to avoid a strlen() call
 
 - Constify struct device_node and property pointers where ever possible
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Merge tag 'devicetree-for-6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux

Pull devicetree updates from Rob Herring:
 "Bindings:

   - Enable dtc "interrupt_provider" warnings for binding examples. Fix
     the warnings in fsl,mu-msi and ti,sci-inta due to this.

   - Convert zii,rave-sp-wdt, zii,rave-sp-pwrbutton, and
     altr,fpga-passive-serial to DT schema format

   - Add some documentation on the different forms of YAML text blocks
     which are a constant source of review comments

   - Fix some schema errors in constraints for arrays

   - Add compatibles for qcom,sar2130p-pdc and onnn,adt7462

  DT core:

   - Allow overlay kunit tests to run CONFIG_OF_OVERLAY=n

   - Add some warnings on deprecated address handling

   - Rework early_init_dt_scan() so the arch can pass in the phys
     address of the DTB as __pa() is not always valid to use. This fixes
     a warning for arm64 with kexec.

   - Add and use some new DT graph iterators for iterating over ports
     and endpoints

   - Rework reserved-memory handling to be sized dynamically for fixed
     regions

   - Optimize of_modalias() to avoid a strlen() call

   - Constify struct device_node and property pointers where ever
     possible"

* tag 'devicetree-for-6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux: (36 commits)
  of: Allow overlay kunit tests to run CONFIG_OF_OVERLAY=n
  dt-bindings: interrupt-controller: qcom,pdc: Add SAR2130P compatible
  of/address: Rework bus matching to avoid warnings
  of: WARN on deprecated #address-cells/#size-cells handling
  of/fdt: Don't use default address cell sizes for address translation
  dt-bindings: Enable dtc "interrupt_provider" warnings
  of/fdt: add dt_phys arg to early_init_dt_scan and early_init_dt_verify
  dt-bindings: cache: qcom,llcc: Fix X1E80100 reg entries
  dt-bindings: watchdog: convert zii,rave-sp-wdt.txt to yaml format
  dt-bindings: input: convert zii,rave-sp-pwrbutton.txt to yaml
  media: xilinx-tpg: use new of_graph functions
  fbdev: omapfb: use new of_graph functions
  gpu: drm: omapdrm: use new of_graph functions
  ASoC: audio-graph-card2: use new of_graph functions
  ASoC: audio-graph-card: use new of_graph functions
  ASoC: test-component: use new of_graph functions
  of: property: use new of_graph functions
  of: property: add of_graph_get_next_port_endpoint()
  of: property: add of_graph_get_next_port()
  of: module: remove strlen() call in of_modalias()
  ...
2024-11-20 13:19:25 -08:00
Linus Torvalds
aad3a0d084 ftrace updates for v6.13:
- Merged tag ftrace-v6.12-rc4
 
   There was a fix to locking in register_ftrace_graph() for shadow stacks
   that was sent upstream. But this code was also being rewritten, and the
   locking fix was needed. Merging this fix was required to continue the
   work.
 
 - Restructure the function graph shadow stack to prepare it for use with
   kretprobes
 
   With the goal of merging the shadow stack logic of function graph and
   kretprobes, some more restructuring of the function shadow stack is
   required.
 
   Move out function graph specific fields from the fgraph infrastructure and
   store it on the new stack variables that can pass data from the entry
   callback to the exit callback.
 
   Hopefully, with this change, the merge of kretprobes to use fgraph shadow
   stacks will be ready by the next merge window.
 
 - Make shadow stack 4k instead of using PAGE_SIZE.
 
   Some architectures have very large PAGE_SIZE values which make its use for
   shadow stacks waste a lot of memory.
 
 - Give shadow stacks its own kmem cache.
 
   When function graph is started, every task on the system gets a shadow
   stack. In the future, shadow stacks may not be 4K in size. Have it have
   its own kmem cache so that whatever size it becomes will still be
   efficient in allocations.
 
 - Initialize profiler graph ops as it will be needed for new updates to fgraph
 
 - Convert to use guard(mutex) for several ftrace and fgraph functions
 
 - Add more comments and documentation
 
 - Show function return address in function graph tracer
 
   Add an option to show the caller of a function at each entry of the
   function graph tracer, similar to what the function tracer does.
 
 - Abstract out ftrace_regs from being used directly like pt_regs
 
   ftrace_regs was created to store a partial pt_regs. It holds only the
   registers and stack information to get to the function arguments and
   return values. On several archs, it is simply a wrapper around pt_regs.
   But some users would access ftrace_regs directly to get the pt_regs which
   will not work on all archs. Make ftrace_regs an abstract structure that
   requires all access to its fields be through accessor functions.
 
 - Show how long it takes to do function code modifications
 
   When code modification for function hooks happen, it always had the time
   recorded in how long it took to do the conversion. But this value was
   never exported. Recently the code was touched due to new ROX modification
   handling that caused a large slow down in doing the modifications and
   had a significant impact on boot times.
 
   Expose the timings in the dyn_ftrace_total_info file. This file was
   created a while ago to show information about memory usage and such to
   implement dynamic function tracing. It's also an appropriate file to store
   the timings of this modification as well. This will make it easier to see
   the impact of changes to code modification on boot up timings.
 
 - Other clean ups and small fixes
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Merge tag 'ftrace-v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull ftrace updates from Steven Rostedt:

 - Restructure the function graph shadow stack to prepare it for use
   with kretprobes

   With the goal of merging the shadow stack logic of function graph and
   kretprobes, some more restructuring of the function shadow stack is
   required.

   Move out function graph specific fields from the fgraph
   infrastructure and store it on the new stack variables that can pass
   data from the entry callback to the exit callback.

   Hopefully, with this change, the merge of kretprobes to use fgraph
   shadow stacks will be ready by the next merge window.

 - Make shadow stack 4k instead of using PAGE_SIZE.

   Some architectures have very large PAGE_SIZE values which make its
   use for shadow stacks waste a lot of memory.

 - Give shadow stacks its own kmem cache.

   When function graph is started, every task on the system gets a
   shadow stack. In the future, shadow stacks may not be 4K in size.
   Have it have its own kmem cache so that whatever size it becomes will
   still be efficient in allocations.

 - Initialize profiler graph ops as it will be needed for new updates to
   fgraph

 - Convert to use guard(mutex) for several ftrace and fgraph functions

 - Add more comments and documentation

 - Show function return address in function graph tracer

   Add an option to show the caller of a function at each entry of the
   function graph tracer, similar to what the function tracer does.

 - Abstract out ftrace_regs from being used directly like pt_regs

   ftrace_regs was created to store a partial pt_regs. It holds only the
   registers and stack information to get to the function arguments and
   return values. On several archs, it is simply a wrapper around
   pt_regs. But some users would access ftrace_regs directly to get the
   pt_regs which will not work on all archs. Make ftrace_regs an
   abstract structure that requires all access to its fields be through
   accessor functions.

 - Show how long it takes to do function code modifications

   When code modification for function hooks happen, it always had the
   time recorded in how long it took to do the conversion. But this
   value was never exported. Recently the code was touched due to new
   ROX modification handling that caused a large slow down in doing the
   modifications and had a significant impact on boot times.

   Expose the timings in the dyn_ftrace_total_info file. This file was
   created a while ago to show information about memory usage and such
   to implement dynamic function tracing. It's also an appropriate file
   to store the timings of this modification as well. This will make it
   easier to see the impact of changes to code modification on boot up
   timings.

 - Other clean ups and small fixes

* tag 'ftrace-v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (22 commits)
  ftrace: Show timings of how long nop patching took
  ftrace: Use guard to take ftrace_lock in ftrace_graph_set_hash()
  ftrace: Use guard to take the ftrace_lock in release_probe()
  ftrace: Use guard to lock ftrace_lock in cache_mod()
  ftrace: Use guard for match_records()
  fgraph: Use guard(mutex)(&ftrace_lock) for unregister_ftrace_graph()
  fgraph: Give ret_stack its own kmem cache
  fgraph: Separate size of ret_stack from PAGE_SIZE
  ftrace: Rename ftrace_regs_return_value to ftrace_regs_get_return_value
  selftests/ftrace: Fix check of return value in fgraph-retval.tc test
  ftrace: Use arch_ftrace_regs() for ftrace_regs_*() macros
  ftrace: Consolidate ftrace_regs accessor functions for archs using pt_regs
  ftrace: Make ftrace_regs abstract from direct use
  fgragh: No need to invoke the function call_filter_check_discard()
  fgraph: Simplify return address printing in function graph tracer
  function_graph: Remove unnecessary initialization in ftrace_graph_ret_addr()
  function_graph: Support recording and printing the function return address
  ftrace: Have calltime be saved in the fgraph storage
  ftrace: Use a running sleeptime instead of saving on shadow stack
  fgraph: Use fgraph data to store subtime for profiler
  ...
2024-11-20 11:34:10 -08:00
Linus Torvalds
0352387523 First step of consolidating the VDSO data page handling:
The VDSO data page handling is architecture specific for historical
   reasons, but there is no real technical reason to do so.
 
   Aside of that VDSO data has become a dump ground for various mechanisms
   and fail to provide a clear separation of the functionalities.
 
   Clean this up by:
 
     * consolidating the VDSO page data by getting rid of architecture
       specific warts especially in x86 and PowerPC.
 
     * removing the last includes of header files which are pulling in other
       headers outside of the VDSO namespace.
 
     * seperating timekeeping and other VDSO data accordingly.
 
   Further consolidation of the VDSO page handling is done in subsequent
   changes scheduled for the next merge window.
 
   This also lays the ground for expanding the VDSO time getters for
   independent PTP clocks in a generic way without making every architecture
   add support seperately.
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Merge tag 'timers-vdso-2024-11-18' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull vdso data page handling updates from Thomas Gleixner:
 "First steps of consolidating the VDSO data page handling.

  The VDSO data page handling is architecture specific for historical
  reasons, but there is no real technical reason to do so.

  Aside of that VDSO data has become a dump ground for various
  mechanisms and fail to provide a clear separation of the
  functionalities.

  Clean this up by:

   - consolidating the VDSO page data by getting rid of architecture
     specific warts especially in x86 and PowerPC.

   - removing the last includes of header files which are pulling in
     other headers outside of the VDSO namespace.

   - seperating timekeeping and other VDSO data accordingly.

  Further consolidation of the VDSO page handling is done in subsequent
  changes scheduled for the next merge window.

  This also lays the ground for expanding the VDSO time getters for
  independent PTP clocks in a generic way without making every
  architecture add support seperately"

* tag 'timers-vdso-2024-11-18' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (42 commits)
  x86/vdso: Add missing brackets in switch case
  vdso: Rename struct arch_vdso_data to arch_vdso_time_data
  powerpc: Split systemcfg struct definitions out from vdso
  powerpc: Split systemcfg data out of vdso data page
  powerpc: Add kconfig option for the systemcfg page
  powerpc/pseries/lparcfg: Use num_possible_cpus() for potential processors
  powerpc/pseries/lparcfg: Fix printing of system_active_processors
  powerpc/procfs: Propagate error of remap_pfn_range()
  powerpc/vdso: Remove offset comment from 32bit vdso_arch_data
  x86/vdso: Split virtual clock pages into dedicated mapping
  x86/vdso: Delete vvar.h
  x86/vdso: Access vdso data without vvar.h
  x86/vdso: Move the rng offset to vsyscall.h
  x86/vdso: Access rng vdso data without vvar.h
  x86/vdso: Access timens vdso data without vvar.h
  x86/vdso: Allocate vvar page from C code
  x86/vdso: Access rng data from kernel without vvar
  x86/vdso: Place vdso_data at beginning of vvar page
  x86/vdso: Use __arch_get_vdso_data() to access vdso data
  x86/mm/mmap: Remove arch_vma_name()
  ...
2024-11-19 16:09:13 -08:00
Linus Torvalds
f41dac3efb Performance events changes for v6.13:
- Uprobes:
     - Add BPF session support (Jiri Olsa)
     - Switch to RCU Tasks Trace flavor for better performance (Andrii Nakryiko)
     - Massively increase uretprobe SMP scalability by SRCU-protecting
       the uretprobe lifetime (Andrii Nakryiko)
     - Kill xol_area->slot_count (Oleg Nesterov)
 
  - Core facilities:
     - Implement targeted high-frequency profiling by adding the ability
       for an event to "pause" or "resume" AUX area tracing (Adrian Hunter)
 
  - VM profiling/sampling:
     - Correct perf sampling with guest VMs (Colton Lewis)
 
  - New hardware support:
     - x86/intel: Add PMU support for Intel ArrowLake-H CPUs (Dapeng Mi)
 
  - Misc fixes and enhancements:
     - x86/intel/pt: Fix buffer full but size is 0 case (Adrian Hunter)
     - x86/amd: Warn only on new bits set (Breno Leitao)
     - x86/amd/uncore: Avoid a false positive warning about snprintf
                       truncation in amd_uncore_umc_ctx_init (Jean Delvare)
     - uprobes: Re-order struct uprobe_task to save some space (Christophe JAILLET)
     - x86/rapl: Move the pmu allocation out of CPU hotplug (Kan Liang)
     - x86/rapl: Clean up cpumask and hotplug (Kan Liang)
     - uprobes: Deuglify xol_get_insn_slot/xol_free_insn_slot paths (Oleg Nesterov)
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'perf-core-2024-11-18' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull performance events updates from Ingo Molnar:
 "Uprobes:
    - Add BPF session support (Jiri Olsa)
    - Switch to RCU Tasks Trace flavor for better performance (Andrii
      Nakryiko)
    - Massively increase uretprobe SMP scalability by SRCU-protecting
      the uretprobe lifetime (Andrii Nakryiko)
    - Kill xol_area->slot_count (Oleg Nesterov)

  Core facilities:
    - Implement targeted high-frequency profiling by adding the ability
      for an event to "pause" or "resume" AUX area tracing (Adrian
      Hunter)

  VM profiling/sampling:
    - Correct perf sampling with guest VMs (Colton Lewis)

  New hardware support:
    - x86/intel: Add PMU support for Intel ArrowLake-H CPUs (Dapeng Mi)

  Misc fixes and enhancements:
    - x86/intel/pt: Fix buffer full but size is 0 case (Adrian Hunter)
    - x86/amd: Warn only on new bits set (Breno Leitao)
    - x86/amd/uncore: Avoid a false positive warning about snprintf
      truncation in amd_uncore_umc_ctx_init (Jean Delvare)
    - uprobes: Re-order struct uprobe_task to save some space
      (Christophe JAILLET)
    - x86/rapl: Move the pmu allocation out of CPU hotplug (Kan Liang)
    - x86/rapl: Clean up cpumask and hotplug (Kan Liang)
    - uprobes: Deuglify xol_get_insn_slot/xol_free_insn_slot paths (Oleg
      Nesterov)"

* tag 'perf-core-2024-11-18' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (32 commits)
  perf/core: Correct perf sampling with guest VMs
  perf/x86: Refactor misc flag assignments
  perf/powerpc: Use perf_arch_instruction_pointer()
  perf/core: Hoist perf_instruction_pointer() and perf_misc_flags()
  perf/arm: Drop unused functions
  uprobes: Re-order struct uprobe_task to save some space
  perf/x86/amd/uncore: Avoid a false positive warning about snprintf truncation in amd_uncore_umc_ctx_init
  perf/x86/intel: Do not enable large PEBS for events with aux actions or aux sampling
  perf/x86/intel/pt: Add support for pause / resume
  perf/core: Add aux_pause, aux_resume, aux_start_paused
  perf/x86/intel/pt: Fix buffer full but size is 0 case
  uprobes: SRCU-protect uretprobe lifetime (with timeout)
  uprobes: allow put_uprobe() from non-sleepable softirq context
  perf/x86/rapl: Clean up cpumask and hotplug
  perf/x86/rapl: Move the pmu allocation out of CPU hotplug
  uprobe: Add support for session consumer
  uprobe: Add data pointer to consumer handlers
  perf/x86/amd: Warn only on new bits set
  uprobes: fold xol_take_insn_slot() into xol_get_insn_slot()
  uprobes: kill xol_area->slot_count
  ...
2024-11-19 13:34:06 -08:00
Linus Torvalds
ba1f9c8fe3 arm64 updates for 6.13:
* Support for running Linux in a protected VM under the Arm Confidential
   Compute Architecture (CCA)
 
 * Guarded Control Stack user-space support. Current patches follow the
   x86 ABI of implicitly creating a shadow stack on clone(). Subsequent
   patches (already on the list) will add support for clone3() allowing
   finer-grained control of the shadow stack size and placement from libc
 
 * AT_HWCAP3 support (not running out of HWCAP2 bits yet but we are
   getting close with the upcoming dpISA support)
 
 * Other arch features:
 
   - In-kernel use of the memcpy instructions, FEAT_MOPS (previously only
     exposed to user; uaccess support not merged yet)
 
   - MTE: hugetlbfs support and the corresponding kselftests
 
   - Optimise CRC32 using the PMULL instructions
 
   - Support for FEAT_HAFT enabling ARCH_HAS_NONLEAF_PMD_YOUNG
 
   - Optimise the kernel TLB flushing to use the range operations
 
   - POE/pkey (permission overlays): further cleanups after bringing the
     signal handler in line with the x86 behaviour for 6.12
 
 * arm64 perf updates:
 
   - Support for the NXP i.MX91 PMU in the existing IMX driver
 
   - Support for Ampere SoCs in the Designware PCIe PMU driver
 
   - Support for Marvell's 'PEM' PCIe PMU present in the 'Odyssey' SoC
 
   - Support for Samsung's 'Mongoose' CPU PMU
 
   - Support for PMUv3.9 finer-grained userspace counter access control
 
   - Switch back to platform_driver::remove() now that it returns 'void'
 
   - Add some missing events for the CXL PMU driver
 
 * Miscellaneous arm64 fixes/cleanups:
 
   - Page table accessors cleanup: type updates, drop unused macros,
     reorganise arch_make_huge_pte() and clean up pte_mkcont(), sanity
     check addresses before runtime P4D/PUD folding
 
   - Command line override for ID_AA64MMFR0_EL1.ECV (advertising the
     FEAT_ECV for the generic timers) allowing Linux to boot with
     firmware deployments that don't set SCTLR_EL3.ECVEn
 
   - ACPI/arm64: tighten the check for the array of platform timer
     structures and adjust the error handling procedure in
     gtdt_parse_timer_block()
 
   - Optimise the cache flush for the uprobes xol slot (skip if no
     change) and other uprobes/kprobes cleanups
 
   - Fix the context switching of tpidrro_el0 when kpti is enabled
 
   - Dynamic shadow call stack fixes
 
   - Sysreg updates
 
   - Various arm64 kselftest improvements
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Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 updates from Catalin Marinas:

 - Support for running Linux in a protected VM under the Arm
   Confidential Compute Architecture (CCA)

 - Guarded Control Stack user-space support. Current patches follow the
   x86 ABI of implicitly creating a shadow stack on clone(). Subsequent
   patches (already on the list) will add support for clone3() allowing
   finer-grained control of the shadow stack size and placement from
   libc

 - AT_HWCAP3 support (not running out of HWCAP2 bits yet but we are
   getting close with the upcoming dpISA support)

 - Other arch features:

     - In-kernel use of the memcpy instructions, FEAT_MOPS (previously
       only exposed to user; uaccess support not merged yet)

     - MTE: hugetlbfs support and the corresponding kselftests

     - Optimise CRC32 using the PMULL instructions

     - Support for FEAT_HAFT enabling ARCH_HAS_NONLEAF_PMD_YOUNG

     - Optimise the kernel TLB flushing to use the range operations

     - POE/pkey (permission overlays): further cleanups after bringing
       the signal handler in line with the x86 behaviour for 6.12

 - arm64 perf updates:

     - Support for the NXP i.MX91 PMU in the existing IMX driver

     - Support for Ampere SoCs in the Designware PCIe PMU driver

     - Support for Marvell's 'PEM' PCIe PMU present in the 'Odyssey' SoC

     - Support for Samsung's 'Mongoose' CPU PMU

     - Support for PMUv3.9 finer-grained userspace counter access
       control

     - Switch back to platform_driver::remove() now that it returns
       'void'

     - Add some missing events for the CXL PMU driver

 - Miscellaneous arm64 fixes/cleanups:

     - Page table accessors cleanup: type updates, drop unused macros,
       reorganise arch_make_huge_pte() and clean up pte_mkcont(), sanity
       check addresses before runtime P4D/PUD folding

     - Command line override for ID_AA64MMFR0_EL1.ECV (advertising the
       FEAT_ECV for the generic timers) allowing Linux to boot with
       firmware deployments that don't set SCTLR_EL3.ECVEn

     - ACPI/arm64: tighten the check for the array of platform timer
       structures and adjust the error handling procedure in
       gtdt_parse_timer_block()

     - Optimise the cache flush for the uprobes xol slot (skip if no
       change) and other uprobes/kprobes cleanups

     - Fix the context switching of tpidrro_el0 when kpti is enabled

     - Dynamic shadow call stack fixes

     - Sysreg updates

     - Various arm64 kselftest improvements

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (168 commits)
  arm64: tls: Fix context-switching of tpidrro_el0 when kpti is enabled
  kselftest/arm64: Try harder to generate different keys during PAC tests
  kselftest/arm64: Don't leak pipe fds in pac.exec_sign_all()
  arm64/ptrace: Clarify documentation of VL configuration via ptrace
  kselftest/arm64: Corrupt P0 in the irritator when testing SSVE
  acpi/arm64: remove unnecessary cast
  arm64/mm: Change protval as 'pteval_t' in map_range()
  kselftest/arm64: Fix missing printf() argument in gcs/gcs-stress.c
  kselftest/arm64: Add FPMR coverage to fp-ptrace
  kselftest/arm64: Expand the set of ZA writes fp-ptrace does
  kselftets/arm64: Use flag bits for features in fp-ptrace assembler code
  kselftest/arm64: Enable build of PAC tests with LLVM=1
  kselftest/arm64: Check that SVCR is 0 in signal handlers
  selftests/mm: Fix unused function warning for aarch64_write_signal_pkey()
  kselftest/arm64: Fix printf() compiler warnings in the arm64 syscall-abi.c tests
  kselftest/arm64: Fix printf() warning in the arm64 MTE prctl() test
  kselftest/arm64: Fix printf() compiler warnings in the arm64 fp tests
  kselftest/arm64: Fix build with stricter assemblers
  arm64/scs: Drop unused prototype __pi_scs_patch_vmlinux()
  arm64/scs: Deal with 64-bit relative offsets in FDE frames
  ...
2024-11-18 18:10:37 -08:00
Catalin Marinas
83ef4a378e Merge branch 'for-next/pkey-signal' into for-next/core
* for-next/pkey-signal:
  : Bring arm64 pkey signal delivery in line with the x86 behaviour
  selftests/mm: Fix unused function warning for aarch64_write_signal_pkey()
  selftests/mm: Define PKEY_UNRESTRICTED for pkey_sighandler_tests
  selftests/mm: Enable pkey_sighandler_tests on arm64
  selftests/mm: Use generic pkey register manipulation
  arm64: signal: Remove unused macro
  arm64: signal: Remove unnecessary check when saving POE state
  arm64: signal: Improve POR_EL0 handling to avoid uaccess failures
  firmware: arm_sdei: Fix the input parameter of cpuhp_remove_state()
  Revert "kasan: Disable Software Tag-Based KASAN with GCC"
  kasan: Fix Software Tag-Based KASAN with GCC
  kasan: Disable Software Tag-Based KASAN with GCC
  Documentation/protection-keys: add AArch64 to documentation
  arm64: set POR_EL0 for kernel threads

# Conflicts:
#	arch/arm64/kernel/signal.c
2024-11-14 12:07:30 +00:00
Catalin Marinas
437330d90c Merge branch 'for-next/mops' into for-next/core
* for-next/mops:
  : More FEAT_MOPS (memcpy instructions) uses - in-kernel routines
  arm64: mops: Document requirements for hypervisors
  arm64: lib: Use MOPS for copy_page() and clear_page()
  arm64: lib: Use MOPS for memcpy() routines
  arm64: mops: Document booting requirement for HCR_EL2.MCE2
  arm64: mops: Handle MOPS exceptions from EL1
  arm64: probes: Disable kprobes/uprobes on MOPS instructions

# Conflicts:
#	arch/arm64/kernel/entry-common.c
2024-11-14 12:07:28 +00:00
Catalin Marinas
5a4332062e Merge branches 'for-next/gcs', 'for-next/probes', 'for-next/asm-offsets', 'for-next/tlb', 'for-next/misc', 'for-next/mte', 'for-next/sysreg', 'for-next/stacktrace', 'for-next/hwcap3', 'for-next/kselftest', 'for-next/crc32', 'for-next/guest-cca', 'for-next/haft' and 'for-next/scs', remote-tracking branch 'arm64/for-next/perf' into for-next/core
* arm64/for-next/perf:
  perf: Switch back to struct platform_driver::remove()
  perf: arm_pmuv3: Add support for Samsung Mongoose PMU
  dt-bindings: arm: pmu: Add Samsung Mongoose core compatible
  perf/dwc_pcie: Fix typos in event names
  perf/dwc_pcie: Add support for Ampere SoCs
  ARM: pmuv3: Add missing write_pmuacr()
  perf/marvell: Marvell PEM performance monitor support
  perf/arm_pmuv3: Add PMUv3.9 per counter EL0 access control
  perf/dwc_pcie: Convert the events with mixed case to lowercase
  perf/cxlpmu: Support missing events in 3.1 spec
  perf: imx_perf: add support for i.MX91 platform
  dt-bindings: perf: fsl-imx-ddr: Add i.MX91 compatible
  drivers perf: remove unused field pmu_node

* for-next/gcs: (42 commits)
  : arm64 Guarded Control Stack user-space support
  kselftest/arm64: Fix missing printf() argument in gcs/gcs-stress.c
  arm64/gcs: Fix outdated ptrace documentation
  kselftest/arm64: Ensure stable names for GCS stress test results
  kselftest/arm64: Validate that GCS push and write permissions work
  kselftest/arm64: Enable GCS for the FP stress tests
  kselftest/arm64: Add a GCS stress test
  kselftest/arm64: Add GCS signal tests
  kselftest/arm64: Add test coverage for GCS mode locking
  kselftest/arm64: Add a GCS test program built with the system libc
  kselftest/arm64: Add very basic GCS test program
  kselftest/arm64: Always run signals tests with GCS enabled
  kselftest/arm64: Allow signals tests to specify an expected si_code
  kselftest/arm64: Add framework support for GCS to signal handling tests
  kselftest/arm64: Add GCS as a detected feature in the signal tests
  kselftest/arm64: Verify the GCS hwcap
  arm64: Add Kconfig for Guarded Control Stack (GCS)
  arm64/ptrace: Expose GCS via ptrace and core files
  arm64/signal: Expose GCS state in signal frames
  arm64/signal: Set up and restore the GCS context for signal handlers
  arm64/mm: Implement map_shadow_stack()
  ...

* for-next/probes:
  : Various arm64 uprobes/kprobes cleanups
  arm64: insn: Simulate nop instruction for better uprobe performance
  arm64: probes: Remove probe_opcode_t
  arm64: probes: Cleanup kprobes endianness conversions
  arm64: probes: Move kprobes-specific fields
  arm64: probes: Fix uprobes for big-endian kernels
  arm64: probes: Fix simulate_ldr*_literal()
  arm64: probes: Remove broken LDR (literal) uprobe support

* for-next/asm-offsets:
  : arm64 asm-offsets.c cleanup (remove unused offsets)
  arm64: asm-offsets: remove PREEMPT_DISABLE_OFFSET
  arm64: asm-offsets: remove DMA_{TO,FROM}_DEVICE
  arm64: asm-offsets: remove VM_EXEC and PAGE_SZ
  arm64: asm-offsets: remove MM_CONTEXT_ID
  arm64: asm-offsets: remove COMPAT_{RT_,SIGFRAME_REGS_OFFSET
  arm64: asm-offsets: remove VMA_VM_*
  arm64: asm-offsets: remove TSK_ACTIVE_MM

* for-next/tlb:
  : TLB flushing optimisations
  arm64: optimize flush tlb kernel range
  arm64: tlbflush: add __flush_tlb_range_limit_excess()

* for-next/misc:
  : Miscellaneous patches
  arm64: tls: Fix context-switching of tpidrro_el0 when kpti is enabled
  arm64/ptrace: Clarify documentation of VL configuration via ptrace
  acpi/arm64: remove unnecessary cast
  arm64/mm: Change protval as 'pteval_t' in map_range()
  arm64: uprobes: Optimize cache flushes for xol slot
  acpi/arm64: Adjust error handling procedure in gtdt_parse_timer_block()
  arm64: fix .data.rel.ro size assertion when CONFIG_LTO_CLANG
  arm64/ptdump: Test both PTE_TABLE_BIT and PTE_VALID for block mappings
  arm64/mm: Sanity check PTE address before runtime P4D/PUD folding
  arm64/mm: Drop setting PTE_TYPE_PAGE in pte_mkcont()
  ACPI: GTDT: Tighten the check for the array of platform timer structures
  arm64/fpsimd: Fix a typo
  arm64: Expose ID_AA64ISAR1_EL1.XS to sanitised feature consumers
  arm64: Return early when break handler is found on linked-list
  arm64/mm: Re-organize arch_make_huge_pte()
  arm64/mm: Drop _PROT_SECT_DEFAULT
  arm64: Add command-line override for ID_AA64MMFR0_EL1.ECV
  arm64: head: Drop SWAPPER_TABLE_SHIFT
  arm64: cpufeature: add POE to cpucap_is_possible()
  arm64/mm: Change pgattr_change_is_safe() arguments as pteval_t

* for-next/mte:
  : Various MTE improvements
  selftests: arm64: add hugetlb mte tests
  hugetlb: arm64: add mte support

* for-next/sysreg:
  : arm64 sysreg updates
  arm64/sysreg: Update ID_AA64MMFR1_EL1 to DDI0601 2024-09

* for-next/stacktrace:
  : arm64 stacktrace improvements
  arm64: preserve pt_regs::stackframe during exec*()
  arm64: stacktrace: unwind exception boundaries
  arm64: stacktrace: split unwind_consume_stack()
  arm64: stacktrace: report recovered PCs
  arm64: stacktrace: report source of unwind data
  arm64: stacktrace: move dump_backtrace() to kunwind_stack_walk()
  arm64: use a common struct frame_record
  arm64: pt_regs: swap 'unused' and 'pmr' fields
  arm64: pt_regs: rename "pmr_save" -> "pmr"
  arm64: pt_regs: remove stale big-endian layout
  arm64: pt_regs: assert pt_regs is a multiple of 16 bytes

* for-next/hwcap3:
  : Add AT_HWCAP3 support for arm64 (also wire up AT_HWCAP4)
  arm64: Support AT_HWCAP3
  binfmt_elf: Wire up AT_HWCAP3 at AT_HWCAP4

* for-next/kselftest: (30 commits)
  : arm64 kselftest fixes/cleanups
  kselftest/arm64: Try harder to generate different keys during PAC tests
  kselftest/arm64: Don't leak pipe fds in pac.exec_sign_all()
  kselftest/arm64: Corrupt P0 in the irritator when testing SSVE
  kselftest/arm64: Add FPMR coverage to fp-ptrace
  kselftest/arm64: Expand the set of ZA writes fp-ptrace does
  kselftets/arm64: Use flag bits for features in fp-ptrace assembler code
  kselftest/arm64: Enable build of PAC tests with LLVM=1
  kselftest/arm64: Check that SVCR is 0 in signal handlers
  kselftest/arm64: Fix printf() compiler warnings in the arm64 syscall-abi.c tests
  kselftest/arm64: Fix printf() warning in the arm64 MTE prctl() test
  kselftest/arm64: Fix printf() compiler warnings in the arm64 fp tests
  kselftest/arm64: Fix build with stricter assemblers
  kselftest/arm64: Test signal handler state modification in fp-stress
  kselftest/arm64: Provide a SIGUSR1 handler in the kernel mode FP stress test
  kselftest/arm64: Implement irritators for ZA and ZT
  kselftest/arm64: Remove unused ADRs from irritator handlers
  kselftest/arm64: Correct misleading comments on fp-stress irritators
  kselftest/arm64: Poll less often while waiting for fp-stress children
  kselftest/arm64: Increase frequency of signal delivery in fp-stress
  kselftest/arm64: Fix encoding for SVE B16B16 test
  ...

* for-next/crc32:
  : Optimise CRC32 using PMULL instructions
  arm64/crc32: Implement 4-way interleave using PMULL
  arm64/crc32: Reorganize bit/byte ordering macros
  arm64/lib: Handle CRC-32 alternative in C code

* for-next/guest-cca:
  : Support for running Linux as a guest in Arm CCA
  arm64: Document Arm Confidential Compute
  virt: arm-cca-guest: TSM_REPORT support for realms
  arm64: Enable memory encrypt for Realms
  arm64: mm: Avoid TLBI when marking pages as valid
  arm64: Enforce bounce buffers for realm DMA
  efi: arm64: Map Device with Prot Shared
  arm64: rsi: Map unprotected MMIO as decrypted
  arm64: rsi: Add support for checking whether an MMIO is protected
  arm64: realm: Query IPA size from the RMM
  arm64: Detect if in a realm and set RIPAS RAM
  arm64: rsi: Add RSI definitions

* for-next/haft:
  : Support for arm64 FEAT_HAFT
  arm64: pgtable: Warn unexpected pmdp_test_and_clear_young()
  arm64: Enable ARCH_HAS_NONLEAF_PMD_YOUNG
  arm64: Add support for FEAT_HAFT
  arm64: setup: name 'tcr2' register
  arm64/sysreg: Update ID_AA64MMFR1_EL1 register

* for-next/scs:
  : Dynamic shadow call stack fixes
  arm64/scs: Drop unused prototype __pi_scs_patch_vmlinux()
  arm64/scs: Deal with 64-bit relative offsets in FDE frames
  arm64/scs: Fix handling of DWARF augmentation data in CIE/FDE frames
2024-11-14 12:07:16 +00:00
Paolo Bonzini
0586ade9e7 LoongArch KVM changes for v6.13
1. Add iocsr and mmio bus simulation in kernel.
 2. Add in-kernel interrupt controller emulation.
 3. Add virt extension support for eiointc irqchip.
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Merge tag 'loongarch-kvm-6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson into HEAD

LoongArch KVM changes for v6.13

1. Add iocsr and mmio bus simulation in kernel.
2. Add in-kernel interrupt controller emulation.
3. Add virt extension support for eiointc irqchip.
2024-11-14 07:06:24 -05:00
Paolo Bonzini
7b541d557f KVM/arm64 changes for 6.13, part #1
- Support for stage-1 permission indirection (FEAT_S1PIE) and
    permission overlays (FEAT_S1POE), including nested virt + the
    emulated page table walker
 
  - Introduce PSCI SYSTEM_OFF2 support to KVM + client driver. This call
    was introduced in PSCIv1.3 as a mechanism to request hibernation,
    similar to the S4 state in ACPI
 
  - Explicitly trap + hide FEAT_MPAM (QoS controls) from KVM guests. As
    part of it, introduce trivial initialization of the host's MPAM
    context so KVM can use the corresponding traps
 
  - PMU support under nested virtualization, honoring the guest
    hypervisor's trap configuration and event filtering when running a
    nested guest
 
  - Fixes to vgic ITS serialization where stale device/interrupt table
    entries are not zeroed when the mapping is invalidated by the VM
 
  - Avoid emulated MMIO completion if userspace has requested synchronous
    external abort injection
 
  - Various fixes and cleanups affecting pKVM, vCPU initialization, and
    selftests
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Merge tag 'kvmarm-6.13' of https://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm64 changes for 6.13, part #1

 - Support for stage-1 permission indirection (FEAT_S1PIE) and
   permission overlays (FEAT_S1POE), including nested virt + the
   emulated page table walker

 - Introduce PSCI SYSTEM_OFF2 support to KVM + client driver. This call
   was introduced in PSCIv1.3 as a mechanism to request hibernation,
   similar to the S4 state in ACPI

 - Explicitly trap + hide FEAT_MPAM (QoS controls) from KVM guests. As
   part of it, introduce trivial initialization of the host's MPAM
   context so KVM can use the corresponding traps

 - PMU support under nested virtualization, honoring the guest
   hypervisor's trap configuration and event filtering when running a
   nested guest

 - Fixes to vgic ITS serialization where stale device/interrupt table
   entries are not zeroed when the mapping is invalidated by the VM

 - Avoid emulated MMIO completion if userspace has requested synchronous
   external abort injection

 - Various fixes and cleanups affecting pKVM, vCPU initialization, and
   selftests
2024-11-14 07:05:36 -05:00
Will Deacon
67ab51cbdf arm64: tls: Fix context-switching of tpidrro_el0 when kpti is enabled
Commit 18011eac28 ("arm64: tls: Avoid unconditional zeroing of
tpidrro_el0 for native tasks") tried to optimise the context switching
of tpidrro_el0 by eliding the clearing of the register when switching
to a native task with kpti enabled, on the erroneous assumption that
the kpti trampoline entry code would already have taken care of the
write.

Although the kpti trampoline does zero the register on entry from a
native task, the check in tls_thread_switch() is on the *next* task and
so we can end up leaving a stale, non-zero value in the register if the
previous task was 32-bit.

Drop the broken optimisation and zero tpidrro_el0 unconditionally when
switching to a native 64-bit task.

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: stable@vger.kernel.org
Fixes: 18011eac28 ("arm64: tls: Avoid unconditional zeroing of tpidrro_el0 for native tasks")
Signed-off-by: Will Deacon <will@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20241114095332.23391-1-will@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-11-14 12:04:13 +00:00
Colton Lewis
2c47e7a74f perf/core: Correct perf sampling with guest VMs
Previously any PMU overflow interrupt that fired while a VCPU was
loaded was recorded as a guest event whether it truly was or not. This
resulted in nonsense perf recordings that did not honor
perf_event_attr.exclude_guest and recorded guest IPs where it should
have recorded host IPs.

Rework the sampling logic to only record guest samples for events with
exclude_guest = 0. This way any host-only events with exclude_guest
set will never see unexpected guest samples. The behaviour of events
with exclude_guest = 0 is unchanged.

Note that events configured to sample both host and guest may still
misattribute a PMI that arrived in the host as a guest event depending
on KVM arch and vendor behavior.

Signed-off-by: Colton Lewis <coltonlewis@google.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Kan Liang <kan.liang@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20241113190156.2145593-6-coltonlewis@google.com
2024-11-14 10:40:01 +01:00
Colton Lewis
04782e6391 perf/core: Hoist perf_instruction_pointer() and perf_misc_flags()
For clarity, rename the arch-specific definitions of these functions
to perf_arch_* to denote they are arch-specifc. Define the
generic-named functions in one place where they can call the
arch-specific ones as needed.

Signed-off-by: Colton Lewis <coltonlewis@google.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Acked-by: Thomas Richter <tmricht@linux.ibm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Acked-by: Kan Liang <kan.liang@linux.intel.com>
Link: https://lore.kernel.org/r/20241113190156.2145593-3-coltonlewis@google.com
2024-11-14 10:40:01 +01:00
Mark Brown
c0139f6cbb arm64/ptrace: Clarify documentation of VL configuration via ptrace
When we configure SVE, SSVE or ZA via ptrace we allow the user to configure
the vector length and specify any of the flags that are accepted when
configuring via prctl(). This includes the S[VM]E_SET_VL_ONEXEC flag which
defers the configuration of the VL until an exec(). We don't do anything to
limit the provision of register data as part of configuring the _ONEXEC VL
but as a function of the VL enumeration support we do this will be
interpreted using the vector length currently configured for the process.

This is all a bit surprising, and probably we should just not have allowed
register data to be specified with _ONEXEC, but it's our ABI so let's
add some explicit documentation in both the ABI documents and the source
calling out what happens.

The comments are also missing the fact that since SME does not have a
mandatory 128 bit VL it is possible for VL enumeration to result in the
configuration of a higher VL than was requested, cover that too.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20241106-arm64-sve-ptrace-vl-set-v1-1-3b164e8b559c@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-11-12 14:53:34 +00:00
Anshuman Khandual
de7fb8d3a2 arm64/mm: Change protval as 'pteval_t' in map_range()
pgprot_t has been defined as an encapsulated structure with pteval_t as its
element. Hence it is prudent to use pteval_t as the type instead of via the
size based u64. Besides pteval_t type might be different size later on with
FEAT_D128.

Cc: Will Deacon <will@kernel.org>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Link: https://lore.kernel.org/r/20241111075249.609493-1-anshuman.khandual@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-11-12 14:46:17 +00:00
Linus Torvalds
9ea7edac83 arm64 fixes for -rc7
- Fix handling of SVE traps from userspace on preemptible kernels when
   converting the saved floating point state into SVE state.
 
 - Remove broken support for the SMCCCv1.3 "SVE discard hint"
   optimisation.
 
 - Disable SME support, as the current support code suffers from numerous
   issues around signal delivery, ptrace access and context-switch which
   can lead to user-visible corruption of the register state.
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Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 fixes from Will Deacon:
 "Here is a (hopefully) final round of arm64 fixes for 6.12 that address
  some user-visible floating point register corruption. Both of the
  Marks have been working on this for a couple of weeks and we've ended
  up in a position where SVE is solid but SME still has enough pending
  issues that the most pragmatic solution for the release and stable
  backports is to disable the feature. Yes, it's a shame, but the
  hardware is rare as hen's teeth at the moment and we're better off
  getting back to a known good state before fixing it all properly.
  We're also improving the selftests for 6.13 to help avoid merging
  broken code in the future.

  Anyway, the good news is that we're removing a lot more code than
  we're adding.

  Summary:

   - Fix handling of SVE traps from userspace on preemptible kernels
     when converting the saved floating point state into SVE state.

   - Remove broken support for the SMCCCv1.3 "SVE discard hint"
     optimisation.

   - Disable SME support, as the current support code suffers from
     numerous issues around signal delivery, ptrace access and
     context-switch which can lead to user-visible corruption of the
     register state"

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: Kconfig: Make SME depend on BROKEN for now
  arm64: smccc: Remove broken support for SMCCCv1.3 SVE discard hint
  arm64/sve: Discard stale CPU state when handling SVE traps
2024-11-08 07:19:58 -10:00
Ard Biesheuvel
60de7a647f arm64/scs: Deal with 64-bit relative offsets in FDE frames
In some cases, the compiler may decide to emit DWARF FDE frames with
64-bit signed fields for the code offset and range fields. This may
happen when using the large code model, for instance, which permits
an executable to be spread out over more than 4 GiB of address space.

Whether this is the case can be inferred from the augmentation data in
the CIE frame, so decode this data before processing the FDE frames.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Tested-by: Sami Tolvanen <samitolvanen@google.com>
Link: https://lore.kernel.org/r/20241106185513.3096442-7-ardb+git@google.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-11-08 16:37:55 +00:00
Ard Biesheuvel
ccf54058f5 arm64/scs: Fix handling of DWARF augmentation data in CIE/FDE frames
The dynamic SCS patching code pretends to parse the DWARF augmentation
data in the CIE (header) frame, and handle accordingly when processing
the individual FDE frames based on this CIE frame. However, the boolean
variable is defined inside the loop, and so the parsed value is ignored.

The same applies to the code alignment field, which is also read from
the header but then discarded.

This was never spotted before because Clang is the only compiler that
supports dynamic SCS patching (which is essentially an Android feature),
and the unwind tables it produces are highly uniform, and match the
de facto defaults.

So instead of testing for the 'z' flag in the augmentation data field,
require a fixed augmentation data string of 'zR', and simplify the rest
of the code accordingly.

Also introduce some error codes to specify why the patching failed, and
log it to the kernel console on failure when this happens when loading a
module. (Doing so for vmlinux is infeasible, as the patching is done
extremely early in the boot.)

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Tested-by: Sami Tolvanen <samitolvanen@google.com>
Link: https://lore.kernel.org/r/20241106185513.3096442-6-ardb+git@google.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-11-08 16:37:55 +00:00
Liao Chang
bdf94836c2 arm64: uprobes: Optimize cache flushes for xol slot
The profiling of single-thread selftests bench reveals a bottlenect in
caches_clean_inval_pou() on ARM64. On my local testing machine, this
function takes approximately 34% of CPU cycles for trig-uprobe-nop and
trig-uprobe-push.

This patch add a check to avoid unnecessary cache flush when writing
instruction to the xol slot. If the instruction is same with the
existing instruction in slot, there is no need to synchronize D/I cache.
Since xol slot allocation and updates occur on the hot path of uprobe
handling, The upstream kernel running on Kunpeng916 (Hi1616), 4 NUMA
nodes, 64 cores@ 2.4GHz reveals this optimization has obvious gain for
nop and push testcases.

Before (next-20240918)
----------------------
uprobe-nop      ( 1 cpus):    0.418 ± 0.001M/s  (  0.418M/s/cpu)
uprobe-push     ( 1 cpus):    0.411 ± 0.005M/s  (  0.411M/s/cpu)
uprobe-ret      ( 1 cpus):    2.052 ± 0.002M/s  (  2.052M/s/cpu)
uretprobe-nop   ( 1 cpus):    0.350 ± 0.000M/s  (  0.350M/s/cpu)
uretprobe-push  ( 1 cpus):    0.353 ± 0.000M/s  (  0.353M/s/cpu)
uretprobe-ret   ( 1 cpus):    1.074 ± 0.001M/s  (  1.074M/s/cpu)

After
-----
uprobe-nop      ( 1 cpus):    0.926 ± 0.000M/s  (  0.926M/s/cpu)
uprobe-push     ( 1 cpus):    0.910 ± 0.001M/s  (  0.910M/s/cpu)
uprobe-ret      ( 1 cpus):    2.056 ± 0.001M/s  (  2.056M/s/cpu)
uretprobe-nop   ( 1 cpus):    0.653 ± 0.001M/s  (  0.653M/s/cpu)
uretprobe-push  ( 1 cpus):    0.645 ± 0.000M/s  (  0.645M/s/cpu)
uretprobe-ret   ( 1 cpus):    1.093 ± 0.001M/s  (  1.093M/s/cpu)

Signed-off-by: Liao Chang <liaochang1@huawei.com>
Link: https://lore.kernel.org/r/20240919121719.2148361-1-liaochang1@huawei.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-11-08 16:25:21 +00:00
Mike Rapoport (Microsoft)
0c3beacf68 asm-generic: introduce text-patching.h
Several architectures support text patching, but they name the header
files that declare patching functions differently.

Make all such headers consistently named text-patching.h and add an empty
header in asm-generic for architectures that do not support text patching.

Link: https://lkml.kernel.org/r/20241023162711.2579610-4-rppt@kernel.org
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> # m68k
Acked-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Tested-by: kdevops <kdevops@lists.linux.dev>
Cc: Andreas Larsson <andreas@gaisler.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Borislav Petkov (AMD) <bp@alien8.de>
Cc: Brian Cain <bcain@quicinc.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Dinh Nguyen <dinguyen@kernel.org>
Cc: Guo Ren <guoren@kernel.org>
Cc: Helge Deller <deller@gmx.de>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Liam R. Howlett <Liam.Howlett@Oracle.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Richard Weinberger <richard@nod.at>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Song Liu <song@kernel.org>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: Vineet Gupta <vgupta@kernel.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-11-07 14:25:15 -08:00
Masahiro Yamada
340fd66c85 arm64: fix .data.rel.ro size assertion when CONFIG_LTO_CLANG
Commit be2881824a ("arm64/build: Assert for unwanted sections")
introduced an assertion to ensure that the .data.rel.ro section does
not exist.

However, this check does not work when CONFIG_LTO_CLANG is enabled,
because .data.rel.ro matches the .data.[0-9a-zA-Z_]* pattern in the
DATA_MAIN macro.

Move the ASSERT() above the RW_DATA() line.

Fixes: be2881824a ("arm64/build: Assert for unwanted sections")
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20241106161843.189927-1-masahiroy@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-11-07 11:33:06 +00:00
Mark Rutland
8c462d5648 arm64: smccc: Remove broken support for SMCCCv1.3 SVE discard hint
SMCCCv1.3 added a hint bit which callers can set in an SMCCC function ID
(AKA "FID") to indicate that it is acceptable for the SMCCC
implementation to discard SVE and/or SME state over a specific SMCCC
call. The kernel support for using this hint is broken and SMCCC calls
may clobber the SVE and/or SME state of arbitrary tasks, though FPSIMD
state is unaffected.

The kernel support is intended to use the hint when there is no SVE or
SME state to save, and to do this it checks whether TIF_FOREIGN_FPSTATE
is set or TIF_SVE is clear in assembly code:

|        ldr     <flags>, [<current_task>, #TSK_TI_FLAGS]
|        tbnz    <flags>, #TIF_FOREIGN_FPSTATE, 1f   // Any live FP state?
|        tbnz    <flags>, #TIF_SVE, 2f               // Does that state include SVE?
|
| 1:     orr     <fid>, <fid>, ARM_SMCCC_1_3_SVE_HINT
| 2:
|        << SMCCC call using FID >>

This is not safe as-is:

(1) SMCCC calls can be made in a preemptible context and preemption can
    result in TIF_FOREIGN_FPSTATE being set or cleared at arbitrary
    points in time. Thus checking for TIF_FOREIGN_FPSTATE provides no
    guarantee.

(2) TIF_FOREIGN_FPSTATE only indicates that the live FP/SVE/SME state in
    the CPU does not belong to the current task, and does not indicate
    that clobbering this state is acceptable.

    When the live CPU state is clobbered it is necessary to update
    fpsimd_last_state.st to ensure that a subsequent context switch will
    reload FP/SVE/SME state from memory rather than consuming the
    clobbered state. This and the SMCCC call itself must happen in a
    critical section with preemption disabled to avoid races.

(3) Live SVE/SME state can exist with TIF_SVE clear (e.g. with only
    TIF_SME set), and checking TIF_SVE alone is insufficient.

Remove the broken support for the SMCCCv1.3 SVE saving hint. This is
effectively a revert of commits:

* cfa7ff959a ("arm64: smccc: Support SMCCC v1.3 SVE register saving hint")
* a7c3acca53 ("arm64: smccc: Save lr before calling __arm_smccc_sve_check()")

... leaving behind the ARM_SMCCC_VERSION_1_3 and ARM_SMCCC_1_3_SVE_HINT
definitions, since these are simply definitions from the SMCCC
specification, and the latter is used in KVM via ARM_SMCCC_CALL_HINTS.

If we want to bring this back in future, we'll probably want to handle
this logic in C where we can use all the usual FPSIMD/SVE/SME helper
functions, and that'll likely require some rework of the SMCCC code
and/or its callers.

Fixes: cfa7ff959a ("arm64: smccc: Support SMCCC v1.3 SVE register saving hint")
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Will Deacon <will@kernel.org>
Cc: stable@vger.kernel.org
Reviewed-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20241106160448.2712997-1-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
2024-11-07 11:18:52 +00:00
Mark Brown
751ecf6afd arm64/sve: Discard stale CPU state when handling SVE traps
The logic for handling SVE traps manipulates saved FPSIMD/SVE state
incorrectly, and a race with preemption can result in a task having
TIF_SVE set and TIF_FOREIGN_FPSTATE clear even though the live CPU state
is stale (e.g. with SVE traps enabled). This has been observed to result
in warnings from do_sve_acc() where SVE traps are not expected while
TIF_SVE is set:

|         if (test_and_set_thread_flag(TIF_SVE))
|                 WARN_ON(1); /* SVE access shouldn't have trapped */

Warnings of this form have been reported intermittently, e.g.

  https://lore.kernel.org/linux-arm-kernel/CA+G9fYtEGe_DhY2Ms7+L7NKsLYUomGsgqpdBj+QwDLeSg=JhGg@mail.gmail.com/
  https://lore.kernel.org/linux-arm-kernel/000000000000511e9a060ce5a45c@google.com/

The race can occur when the SVE trap handler is preempted before and
after manipulating the saved FPSIMD/SVE state, starting and ending on
the same CPU, e.g.

| void do_sve_acc(unsigned long esr, struct pt_regs *regs)
| {
|         // Trap on CPU 0 with TIF_SVE clear, SVE traps enabled
|         // task->fpsimd_cpu is 0.
|         // per_cpu_ptr(&fpsimd_last_state, 0) is task.
|
|         ...
|
|         // Preempted; migrated from CPU 0 to CPU 1.
|         // TIF_FOREIGN_FPSTATE is set.
|
|         get_cpu_fpsimd_context();
|
|         if (test_and_set_thread_flag(TIF_SVE))
|                 WARN_ON(1); /* SVE access shouldn't have trapped */
|
|         sve_init_regs() {
|                 if (!test_thread_flag(TIF_FOREIGN_FPSTATE)) {
|                         ...
|                 } else {
|                         fpsimd_to_sve(current);
|                         current->thread.fp_type = FP_STATE_SVE;
|                 }
|         }
|
|         put_cpu_fpsimd_context();
|
|         // Preempted; migrated from CPU 1 to CPU 0.
|         // task->fpsimd_cpu is still 0
|         // If per_cpu_ptr(&fpsimd_last_state, 0) is still task then:
|         // - Stale HW state is reused (with SVE traps enabled)
|         // - TIF_FOREIGN_FPSTATE is cleared
|         // - A return to userspace skips HW state restore
| }

Fix the case where the state is not live and TIF_FOREIGN_FPSTATE is set
by calling fpsimd_flush_task_state() to detach from the saved CPU
state. This ensures that a subsequent context switch will not reuse the
stale CPU state, and will instead set TIF_FOREIGN_FPSTATE, forcing the
new state to be reloaded from memory prior to a return to userspace.

Fixes: cccb78ce89 ("arm64/sve: Rework SVE access trap to convert state in registers")
Reported-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20241030-arm64-fpsimd-foreign-flush-v1-1-bd7bd66905a2@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
2024-11-06 13:49:39 +00:00
Yicong Yang
efe7254135 arm64: Add support for FEAT_HAFT
Armv8.9/v9.4 introduces the feature Hardware managed Access Flag
for Table descriptors (FEAT_HAFT). The feature is indicated by
ID_AA64MMFR1_EL1.HAFDBS == 0b0011 and can be enabled by
TCR2_EL1.HAFT so it has a dependency on FEAT_TCR2.

Adds the Kconfig for FEAT_HAFT and support detecting and enabling
the feature. The feature is enabled in __cpu_setup() before MMU on
just like HA. A CPU capability is added to notify the user of the
feature.

Add definition of P{G,4,U,M}D_TABLE_AF bit and set the AF bit
when creating the page table, which will save the hardware
from having to update them at runtime. This will be ignored if
FEAT_HAFT is not enabled.

The AF bit of table descriptors cannot be managed by the software
per spec, unlike the HA. So this should be used only if it's supported
system wide by system_supports_haft().

Signed-off-by: Yicong Yang <yangyicong@hisilicon.com>
Link: https://lore.kernel.org/r/20241102104235.62560-4-yangyicong@huawei.com
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
[catalin.marinas@arm.com: added the ID check back to __cpu_setup in case of future CPU errata]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-11-05 13:18:35 +00:00
Kevin Brodsky
8edbbfcc1e arm64: signal: Remove unused macro
Commit 33f082614c ("arm64: signal: Allow expansion of the signal
frame") introduced the BASE_SIGFRAME_SIZE macro but it has
apparently never been used; just remove it.

Reviewed-by: Dave Martin <Dave.Martin@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com>
Link: https://lore.kernel.org/r/20241029144539.111155-4-kevin.brodsky@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-11-04 16:31:25 +00:00
Kevin Brodsky
466ece4c6e arm64: signal: Remove unnecessary check when saving POE state
The POE frame record is allocated unconditionally if POE is
supported. If the allocation fails, a SIGSEGV is delivered before
setup_sigframe() can be reached. As a result there is no need to
consider poe_offset before saving POR_EL0; just remove that check.
This is in line with other frame records (FPMR, TPIDR2).

Reviewed-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Dave Martin <Dave.Martin@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com>
Link: https://lore.kernel.org/r/20241029144539.111155-3-kevin.brodsky@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-11-04 16:31:25 +00:00
Christophe JAILLET
525fd6a1b3 arm64/fpsimd: Fix a typo
s/FPSMID/FPSIMD/
M and I swapped. Fix it.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/2cbcb42615e9265bccc9b746465d7998382e605d.1730539907.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-11-04 12:48:24 +00:00
Thomas Weißschuh
461c966866 arm64: vdso: Use only one single vvar mapping
The vvar mapping is the same for all processes. Use a single mapping to
simplify the logic and align it with the other architectures.

In addition this will enable the move of the vvar handling into generic code.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Will Deacon <will@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/all/20241010-vdso-generic-base-v1-5-b64f0842d512@linutronix.de
2024-11-02 12:37:33 +01:00
Thomas Weißschuh
0973fed6a5 arm64: vdso: Drop LBASE_VDSO
This constant is always "0", providing no value and making the logic
harder to understand.
Also prepare for a consolidation of the vdso linkerscript logic by
aligning it with other architectures.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/all/20241010-vdso-generic-base-v1-4-b64f0842d512@linutronix.de
2024-11-02 12:37:33 +01:00
Linus Torvalds
3dfffd506e arm64 fixes for -rc6
- Fix handling of POR_EL0 during signal delivery so that pushing the
   signal context doesn't fail based on the pkey configuration of the
   interrupted context and align our user-visible behaviour with that of
   x86.
 
 - Fix a bogus pointer being passed to the CPU hotplug code from the
   Arm SDEI driver.
 
 - Re-enable software tag-based KASAN with GCC by using an alternative
   implementation of '__no_sanitize_address'.
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Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 fixes from Will Deacon:
 "The important one is a change to the way in which we handle protection
  keys around signal delivery so that we're more closely aligned with
  the x86 behaviour, however there is also a revert of the previous fix
  to disable software tag-based KASAN with GCC, since a workaround
  materialised shortly afterwards.

  I'd love to say we're done with 6.12, but we're aware of some
  longstanding fpsimd register corruption issues that we're almost at
  the bottom of resolving.

  Summary:

   - Fix handling of POR_EL0 during signal delivery so that pushing the
     signal context doesn't fail based on the pkey configuration of the
     interrupted context and align our user-visible behaviour with that
     of x86.

   - Fix a bogus pointer being passed to the CPU hotplug code from the
     Arm SDEI driver.

   - Re-enable software tag-based KASAN with GCC by using an alternative
     implementation of '__no_sanitize_address'"

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: signal: Improve POR_EL0 handling to avoid uaccess failures
  firmware: arm_sdei: Fix the input parameter of cpuhp_remove_state()
  Revert "kasan: Disable Software Tag-Based KASAN with GCC"
  kasan: Fix Software Tag-Based KASAN with GCC
2024-11-01 07:54:11 -10:00
Marc Zyngier
2287a4c1e1 arm64: Expose ID_AA64ISAR1_EL1.XS to sanitised feature consumers
Despite KVM now being able to deal with XS-tagged TLBIs, we still don't
expose these feature bits to KVM.

Plumb in the feature in ID_AA64ISAR1_EL1.

Fixes: 0feec7769a ("KVM: arm64: nv: Add handling of NXS-flavoured TLBI operations")
Signed-off-by: Marc Zyngier <maz@kernel.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Link: https://lore.kernel.org/r/20241031083519.364313-1-maz@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-11-01 16:35:57 +00:00
Liao Chang
9a0e3b92b0 arm64: Return early when break handler is found on linked-list
The search for breakpoint handlers iterate through the entire
linked list. Given that all registered hook has a valid fn field, and no
registered hooks share the same mask and imm. This commit optimize the
efficiency slightly by returning early as a matching handler is found.

Signed-off-by: Liao Chang <liaochang1@huawei.com>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20241024034120.3814224-1-liaochang1@huawei.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-11-01 15:31:02 +00:00
James Morse
09e6b306f3 arm64: cpufeature: discover CPU support for MPAM
ARMv8.4 adds support for 'Memory Partitioning And Monitoring' (MPAM)
which describes an interface to cache and bandwidth controls wherever
they appear in the system.

Add support to detect MPAM. Like SVE, MPAM has an extra id register that
describes some more properties, including the virtualisation support,
which is optional. Detect this separately so we can detect
mismatched/insane systems, but still use MPAM on the host even if the
virtualisation support is missing.

MPAM needs enabling at the highest implemented exception level, otherwise
the register accesses trap. The 'enabled' flag is accessible to lower
exception levels, but its in a register that traps when MPAM isn't enabled.
The cpufeature 'matches' hook is extended to test this on one of the
CPUs, so that firmware can emulate MPAM as disabled if it is reserved
for use by secure world.

Secondary CPUs that appear late could trip cpufeature's 'lower safe'
behaviour after the MPAM properties have been advertised to user-space.
Add a verify call to ensure late secondaries match the existing CPUs.

(If you have a boot failure that bisects here its likely your CPUs
advertise MPAM in the id registers, but firmware failed to either enable
or MPAM, or emulate the trap as if it were disabled)

Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Joey Gouly <joey.gouly@arm.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Tested-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20241030160317.2528209-4-joey.gouly@arm.com
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-10-31 18:09:38 +00:00
Usama Arif
b2473a3597 of/fdt: add dt_phys arg to early_init_dt_scan and early_init_dt_verify
__pa() is only intended to be used for linear map addresses and using
it for initial_boot_params which is in fixmap for arm64 will give an
incorrect value. Hence save the physical address when it is known at
boot time when calling early_init_dt_scan for arm64 and use it at kexec
time instead of converting the virtual address using __pa().

Note that arm64 doesn't need the FDT region reserved in the DT as the
kernel explicitly reserves the passed in FDT. Therefore, only a debug
warning is fixed with this change.

Reported-by: Breno Leitao <leitao@debian.org>
Suggested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Usama Arif <usamaarif642@gmail.com>
Fixes: ac10be5cdb ("arm64: Use common of_kexec_alloc_and_setup_fdt()")
Link: https://lore.kernel.org/r/20241023171426.452688-1-usamaarif642@gmail.com
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
2024-10-29 15:32:45 -05:00
Kevin Brodsky
2e8a1acea8 arm64: signal: Improve POR_EL0 handling to avoid uaccess failures
Reset POR_EL0 to "allow all" before writing the signal frame, preventing
spurious uaccess failures.

When POE is supported, the POR_EL0 register constrains memory
accesses based on the target page's POIndex (pkey). This raises the
question: what constraints should apply to a signal handler? The
current answer is that POR_EL0 is reset to POR_EL0_INIT when
invoking the handler, giving it full access to POIndex 0. This is in
line with x86's MPK support and remains unchanged.

This is only part of the story, though. POR_EL0 constrains all
unprivileged memory accesses, meaning that uaccess routines such as
put_user() are also impacted. As a result POR_EL0 may prevent the
signal frame from being written to the signal stack (ultimately
causing a SIGSEGV). This is especially concerning when an alternate
signal stack is used, because userspace may want to prevent access
to it outside of signal handlers. There is currently no provision
for that: POR_EL0 is reset after writing to the stack, and
POR_EL0_INIT only enables access to POIndex 0.

This patch ensures that POR_EL0 is reset to its most permissive
state before the signal stack is accessed. Once the signal frame has
been fully written, POR_EL0 is still set to POR_EL0_INIT - it is up
to the signal handler to enable access to additional pkeys if
needed. As to sigreturn(), it expects having access to the stack
like any other syscall; we only need to ensure that POR_EL0 is
restored from the signal frame after all uaccess calls. This
approach is in line with the recent x86/pkeys series [1].

Resetting POR_EL0 early introduces some complications, in that we
can no longer read the register directly in preserve_poe_context().
This is addressed by introducing a struct (user_access_state)
and helpers to manage any such register impacting user accesses
(uaccess and accesses in userspace). Things look like this on signal
delivery:

1. Save original POR_EL0 into struct [save_reset_user_access_state()]
2. Set POR_EL0 to "allow all"  [save_reset_user_access_state()]
3. Create signal frame
4. Write saved POR_EL0 value to the signal frame [preserve_poe_context()]
5. Finalise signal frame
6. If all operations succeeded:
  a. Set POR_EL0 to POR_EL0_INIT [set_handler_user_access_state()]
  b. Else reset POR_EL0 to its original value [restore_user_access_state()]

If any step fails when setting up the signal frame, the process will
be sent a SIGSEGV, which it may be able to handle. Step 6.b ensures
that the original POR_EL0 is saved in the signal frame when
delivering that SIGSEGV (so that the original value is restored by
sigreturn).

The return path (sys_rt_sigreturn) doesn't strictly require any change
since restore_poe_context() is already called last. However, to
avoid uaccess calls being accidentally added after that point, we
use the same approach as in the delivery path, i.e. separating
uaccess from writing to the register:

1. Read saved POR_EL0 value from the signal frame [restore_poe_context()]
2. Set POR_EL0 to the saved value [restore_user_access_state()]

[1] https://lore.kernel.org/lkml/20240802061318.2140081-1-aruna.ramakrishna@oracle.com/

Fixes: 9160f7e909 ("arm64: add POE signal support")
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com>
Link: https://lore.kernel.org/r/20241029144539.111155-2-kevin.brodsky@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
2024-10-29 17:59:12 +00:00
Julian Vetter
0110feaaf6
arm64: Use new fallback IO memcpy/memset
Use the new fallback memcpy_{from,to}io and memset_io functions from
lib/iomem_copy.c on the arm64 processor architecture.

Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Yann Sionneau <ysionneau@kalrayinc.com>
Signed-off-by: Julian Vetter <jvetter@kalrayinc.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2024-10-28 21:44:29 +00:00
Marc Zyngier
358dd4a9bd arm64: Add command-line override for ID_AA64MMFR0_EL1.ECV
It appears that relatively popular hardware out there implements
the CNTPOFF_EL2 variant of FEAT_ECV, advertises it via ID_AA64MMFR0_EL1,
but cannot be bothered to set SCR_EL3.ECVEn to 1.

You would probably think that "this is fine, EL3 will take the
trap on access to CNTPOFF_EL2 and flip the ECVEn bit", as that's
what a semi-decent firmware implementation would do.

But no. None of that. This particular implementation takes the trap,
considers its purpose in life, decides that it has none, and *RESETS*
the system.

Yes, x1e001de, I'm talking about you.

In order to allow this machine to be promoted slightly above the
level of a glorified door-stop, add a new "id_aa64mmfr0.ecv" override.
allowing the kernel to pretend this option was never there.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20241021181434.1052974-1-maz@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-10-23 11:57:46 +01:00
Suzuki K Poulose
42be24a417 arm64: Enable memory encrypt for Realms
Use the memory encryption APIs to trigger a RSI call to request a
transition between protected memory and shared memory (or vice versa)
and updating the kernel's linear map of modified pages to flip the top
bit of the IPA. This requires that block mappings are not used in the
direct map for realm guests.

Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Co-developed-by: Steven Price <steven.price@arm.com>
Signed-off-by: Steven Price <steven.price@arm.com>
Link: https://lore.kernel.org/r/20241017131434.40935-10-steven.price@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-10-23 10:19:33 +01:00
Steven Price
fbf979a013 arm64: Enforce bounce buffers for realm DMA
Within a realm guest it's not possible for a device emulated by the VMM
to access arbitrary guest memory. So force the use of bounce buffers to
ensure that the memory the emulated devices are accessing is in memory
which is explicitly shared with the host.

This adds a call to swiotlb_update_mem_attributes() which calls
set_memory_decrypted() to ensure the bounce buffer memory is shared with
the host. For non-realm guests or hosts this is a no-op.

Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Co-developed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Steven Price <steven.price@arm.com>
Link: https://lore.kernel.org/r/20241017131434.40935-8-steven.price@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-10-23 10:19:32 +01:00
Suzuki K Poulose
491db21d82 efi: arm64: Map Device with Prot Shared
Device mappings need to be emulated by the VMM so must be mapped shared
with the host.

Reviewed-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Steven Price <steven.price@arm.com>
Link: https://lore.kernel.org/r/20241017131434.40935-7-steven.price@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-10-23 10:19:32 +01:00
Suzuki K Poulose
3c6c706139 arm64: rsi: Map unprotected MMIO as decrypted
Instead of marking every MMIO as shared, check if the given region is
"Protected" and apply the permissions accordingly.

Reviewed-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Steven Price <steven.price@arm.com>
Link: https://lore.kernel.org/r/20241017131434.40935-6-steven.price@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-10-23 10:19:32 +01:00
Suzuki K Poulose
3715894376 arm64: rsi: Add support for checking whether an MMIO is protected
On Arm CCA, with RMM-v1.0, all MMIO regions are shared. However, in
the future, an Arm CCA-v1.0 compliant guest may be run in a lesser
privileged partition in the Realm World (with Arm CCA-v1.1 Planes
feature). In this case, some of the MMIO regions may be emulated
by a higher privileged component in the Realm world, i.e, protected.

Thus the guest must decide today, whether a given MMIO region is shared
vs Protected and create the stage1 mapping accordingly. On Arm CCA, this
detection is based on the "IPA State" (RIPAS == RIPAS_IO). Provide a
helper to run this check on a given range of MMIO.

Also, provide a arm64 helper which may be hooked in by other solutions.

Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Steven Price <steven.price@arm.com>
Link: https://lore.kernel.org/r/20241017131434.40935-5-steven.price@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-10-23 10:19:32 +01:00
Steven Price
3993069549 arm64: realm: Query IPA size from the RMM
The top bit of the configured IPA size is used as an attribute to
control whether the address is protected or shared. Query the
configuration from the RMM to assertain which bit this is.

Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Co-developed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Steven Price <steven.price@arm.com>
Link: https://lore.kernel.org/r/20241017131434.40935-4-steven.price@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-10-23 10:19:32 +01:00
Suzuki K Poulose
c077711f71 arm64: Detect if in a realm and set RIPAS RAM
Detect that the VM is a realm guest by the presence of the RSI
interface. This is done after PSCI has been initialised so that we can
check the SMCCC conduit before making any RSI calls.

If in a realm then iterate over all memory ensuring that it is marked as
RIPAS RAM. The loader is required to do this for us, however if some
memory is missed this will cause the guest to receive a hard to debug
external abort at some random point in the future. So for a
belt-and-braces approach set all memory to RIPAS RAM. Any failure here
implies that the RAM regions passed to Linux are incorrect so panic()
promptly to make the situation clear.

Reviewed-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Co-developed-by: Steven Price <steven.price@arm.com>
Signed-off-by: Steven Price <steven.price@arm.com>
Link: https://lore.kernel.org/r/20241017131434.40935-3-steven.price@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-10-23 10:19:32 +01:00