Commit Graph

495 Commits

Author SHA1 Message Date
Breno Leitao
ecbccdbdab efi/runtime-wrappers: factor out efi_rts_park_worker()
x86's efi_crash_gracefully_on_page_fault() ends in an infinite
schedule() loop so the kworker that faulted in firmware never runs
efi_rts_wq again. A later change needs the same "park this worker
forever" primitive on the runtime service timeout path, so factor the
loop into a shared efi_rts_park_worker() and call it from the x86
page-fault handler.

No functional change.

Signed-off-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2026-08-20 14:45:04 +03:00
Ard Biesheuvel
2c340aab54 x86/efi: Restore IRQ state in EFI page fault handler
The kernel's softirq API does not permit re-enabling softirqs while IRQs
are disabled. The reason for this is that local_bh_enable() will not
only re-enable delivery of softirqs over the back of IRQs, it will also
handle any pending softirqs immediately, regardless of whether IRQs are
enabled at that point.

For this reason, commit

  d021985504 ("x86/fpu: Improve crypto performance by making kernel-mode FPU reliably usable in softirqs")

disables softirqs only when IRQs are enabled, as it is not permitted
otherwise, but also unnecessary, given that asynchronous softirq
delivery never happens to begin with while IRQs are disabled.

However, this does mean that entering a kernel mode FPU section with
IRQs enabled and leaving it with IRQs disabled leads to problems, as
identified by Sashiko [0]: the EFI page fault handler is called from
page_fault_oops() with IRQs disabled, and thus ends the kernel mode FPU
section with IRQs disabled as well, regardless of whether IRQs were
enabled when it was started. This may result in schedule() being called
with a non-zero preempt_count, causing a BUG().

So take care to re-enable IRQs when handling any EFI page faults if they
were taken with IRQs enabled.

[0] https://sashiko.dev/#/patchset/20260430074107.27051-1-ivan.hu%40canonical.com

Cc: Eric Biggers <ebiggers@kernel.org>
Cc: Ivan Hu <ivan.hu@canonical.com>
Cc: x86@kernel.org
Cc: <stable@vger.kernel.org>
Fixes: d021985504 ("x86/fpu: Improve crypto performance by making kernel-mode FPU reliably usable in softirqs")
Reviewed-by: Eric Biggers <ebiggers@kernel.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2026-05-05 09:31:28 +02:00
Ivan Hu
088f65e206 x86/efi: Fix graceful fault handling after FPU softirq changes
Since commit d021985504 ("x86/fpu: Improve crypto performance by
making kernel-mode FPU reliably usable in softirqs"), kernel_fpu_begin()
calls fpregs_lock() which uses local_bh_disable() instead of the
previous preempt_disable(). This sets SOFTIRQ_OFFSET in preempt_count
during the entire EFI runtime service call, causing in_interrupt() to
return true in normal task context.

The graceful page fault handler efi_crash_gracefully_on_page_fault()
uses in_interrupt() to bail out for faults in real interrupt context.
With SOFTIRQ_OFFSET now set, the handler always bails out, leaving EFI
firmware page faults unhandled. This escalates to die() which also sees
in_interrupt() as true and calls panic("Fatal exception in interrupt"),
resulting in a hard system freeze. On systems with buggy firmware that
triggers page faults during EFI runtime calls (e.g., accessing unmapped
memory in GetTime()), this causes an unrecoverable hang instead of the
expected graceful EFI_ABORTED recovery.

Fix by replacing in_interrupt() with !in_task(). This preserves the
original intent of bailing for interrupts or NMI faults, while no longer
falsely triggering from the FPU code path's local_bh_disable().

Fixes: d021985504 ("x86/fpu: Improve crypto performance by making kernel-mode FPU reliably usable in softirqs")
Cc: <stable@vger.kernel.org>
Signed-off-by: Ivan Hu <ivan.hu@canonical.com>
[ardb: Sashiko spotted that using 'in_hardirq() || in_nmi()' leaves a
       window where a softirq may be taken before fpregs_lock() is
       called, but after efi_rts_work.efi_rts_id has been assigned,
       and any page faults occurring in that window will then be
       misidentified as having been caused by the firmware. Instead,
       use !in_task(), which incorporates in_serving_softirq(). ]
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2026-05-04 12:41:51 +02:00
Linus Torvalds
9055c64567 memblock: updates for 7.0-rc1
* improve debugability of reserve_mem kernel parameter handling with print
   outs in case of a failure and debugfs info showing what was actually
   reserved
 * Make memblock_free_late() and free_reserved_area() use the same core
   logic for freeing the memory to buddy and ensure it takes care of
   updating memblock arrays when ARCH_KEEP_MEMBLOCK is enabled.
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Merge tag 'memblock-v7.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock

Pull memblock updates from Mike Rapoport:

 - improve debuggability of reserve_mem kernel parameter handling with
   print outs in case of a failure and debugfs info showing what was
   actually reserved

 - Make memblock_free_late() and free_reserved_area() use the same core
   logic for freeing the memory to buddy and ensure it takes care of
   updating memblock arrays when ARCH_KEEP_MEMBLOCK is enabled.

* tag 'memblock-v7.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock:
  x86/alternative: delay freeing of smp_locks section
  memblock: warn when freeing reserved memory before memory map is initialized
  memblock, treewide: make memblock_free() handle late freeing
  memblock: make free_reserved_area() update memblock if ARCH_KEEP_MEMBLOCK=y
  memblock: extract page freeing from free_reserved_area() into a helper
  memblock: make free_reserved_area() more robust
  mm: move free_reserved_area() to mm/memblock.c
  powerpc: opal-core: pair alloc_pages_exact() with free_pages_exact()
  powerpc: fadump: pair alloc_pages_exact() with free_pages_exact()
  memblock: reserve_mem: fix end caclulation in reserve_mem_release_by_name()
  memblock: move reserve_bootmem_range() to memblock.c and make it static
  memblock: Add reserve_mem debugfs info
  memblock: Print out errors on reserve_mem parser
2026-04-18 11:29:14 -07:00
Linus Torvalds
9cdca33667 integrity-v7.1
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Merge tag 'integrity-v7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity

Pull integrity updates from Mimi Zohar:
 "There are two main changes, one feature removal, some code cleanup,
  and a number of bug fixes.

  Main changes:
   - Detecting secure boot mode was limited to IMA. Make detecting
     secure boot mode accessible to EVM and other LSMs
   - IMA sigv3 support was limited to fsverity. Add IMA sigv3 support
     for IMA regular file hashes and EVM portable signatures

  Remove:
   - Remove IMA support for asychronous hash calculation originally
     added for hardware acceleration

  Cleanup:
   - Remove unnecessary Kconfig CONFIG_MODULE_SIG and CONFIG_KEXEC_SIG
     tests
   - Add descriptions of the IMA atomic flags

  Bug fixes:
   - Like IMA, properly limit EVM "fix" mode
   - Define and call evm_fix_hmac() to update security.evm
   - Fallback to using i_version to detect file change for filesystems
     that do not support STATX_CHANGE_COOKIE
   - Address missing kernel support for configured (new) TPM hash
     algorithms
   - Add missing crypto_shash_final() return value"

* tag 'integrity-v7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity:
  evm: Enforce signatures version 3 with new EVM policy 'bit 3'
  integrity: Allow sigv3 verification on EVM_XATTR_PORTABLE_DIGSIG
  ima: add support to require IMA sigv3 signatures
  ima: add regular file data hash signature version 3 support
  ima: Define asymmetric_verify_v3() to verify IMA sigv3 signatures
  ima: remove buggy support for asynchronous hashes
  integrity: Eliminate weak definition of arch_get_secureboot()
  ima: Add code comments to explain IMA iint cache atomic_flags
  ima_fs: Correctly create securityfs files for unsupported hash algos
  ima: check return value of crypto_shash_final() in boot aggregate
  ima: Define and use a digest_size field in the ima_algo_desc structure
  powerpc/ima: Drop unnecessary check for CONFIG_MODULE_SIG
  ima: efi: Drop unnecessary check for CONFIG_MODULE_SIG/CONFIG_KEXEC_SIG
  ima: fallback to using i_version to detect file change
  evm: fix security.evm for a file with IMA signature
  s390: Drop unnecessary CONFIG_IMA_SECURE_AND_OR_TRUSTED_BOOT
  evm: Don't enable fix mode when secure boot is enabled
  integrity: Make arch_ima_get_secureboot integrity-wide
2026-04-17 15:42:01 -07:00
Linus Torvalds
9f2bb6c7b3 - Complete LASS enabling: deal with vsyscall and EFI
- Clean up CPUID usage in newer Intel audio driver
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Merge tag 'x86_cpu_for_7.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 cpu updates from Dave Hansen:

 - Complete LASS enabling: deal with vsyscall and EFI

   The existing Linear Address Space Separation (LASS) support punted
   on support for common EFI and vsyscall configs. Complete the
   implementation by supporting EFI and vsyscall=xonly.

 - Clean up CPUID usage in newer Intel "avs" audio driver and update the
   x86-cpuid-db file

* tag 'x86_cpu_for_7.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  tools/x86/kcpuid: Update bitfields to x86-cpuid-db v3.0
  ASoC: Intel: avs: Include CPUID header at file scope
  ASoC: Intel: avs: Check maximum valid CPUID leaf
  x86/cpu: Remove LASS restriction on vsyscall emulation
  x86/vsyscall: Disable LASS if vsyscall mode is set to EMULATE
  x86/vsyscall: Restore vsyscall=xonly mode under LASS
  x86/traps: Consolidate user fixups in the #GP handler
  x86/vsyscall: Reorganize the page fault emulation code
  x86/cpu: Remove LASS restriction on EFI
  x86/efi: Disable LASS while executing runtime services
  x86/cpu: Defer LASS enabling until userspace comes up
2026-04-14 14:24:45 -07:00
Mike Rapoport (Microsoft)
87ce9e83ab memblock, treewide: make memblock_free() handle late freeing
It shouldn't be responsibility of memblock users to detect if they free
memory allocated from memblock late and should use memblock_free_late().

Make memblock_free() and memblock_phys_free() take care of late memory
freeing and drop memblock_free_late().

Link: https://patch.msgid.link/20260323074836.3653702-9-rppt@kernel.org
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
2026-04-01 11:20:15 +03:00
Mike Rapoport (Microsoft)
217c0a5c17 x86/efi: efi_unmap_boot_services: fix calculation of ranges_to_free size
ranges_to_free array should have enough room to store the entire EFI
memmap plus an extra element for NULL entry.
The calculation of this array size wrongly adds 1 to the overall size
instead of adding 1 to the number of elements.

Add parentheses to properly size the array.

Reported-by: Guenter Roeck <linux@roeck-us.net>
Fixes: a4b0bf6a40 ("x86/efi: defer freeing of boot services memory")
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2026-03-20 15:31:10 +01:00
Coiby Xu
31a6a07eef integrity: Make arch_ima_get_secureboot integrity-wide
EVM and other LSMs need the ability to query the secure boot status of
the system, without directly calling the IMA arch_ima_get_secureboot
function. Refactor the secure boot status check into a general function
named arch_get_secureboot.

Reported-and-suggested-by: Mimi Zohar <zohar@linux.ibm.com>
Suggested-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Coiby Xu <coxu@redhat.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2026-03-05 11:10:08 -05:00
Sohil Mehta
0021e71cfb x86/efi: Disable LASS while executing runtime services
Ideally, EFI runtime services should switch to kernel virtual addresses
after SetVirtualAddressMap(). However, firmware implementations are
known to be buggy in this regard and continue to access physical
addresses. The kernel maintains a 1:1 mapping of all runtime services
code and data regions to avoid breaking such firmware.

LASS enforcement relies on bit 63 of the virtual address, which would
block such accesses to the lower half. Unfortunately, not doing anything
could lead to #GP faults when users update to a kernel with LASS
enabled.

One option is to use a STAC/CLAC pair to temporarily disable LASS data
enforcement. However, there is no guarantee that the stray accesses
would only touch data and not perform instruction fetches. Also, relying
on the AC bit would depend on the runtime calls preserving RFLAGS, which
is highly unlikely in practice.

Instead, use the big hammer and switch off the entire LASS mechanism
temporarily by clearing CR4.LASS. Runtime services are called in the
context of efi_mm, which has explicitly unmapped any memory EFI isn't
allowed to touch (including userspace). So, do this right after
switching to efi_mm to avoid any security impact.

Some runtime services can be invoked during boot when LASS isn't active.
Use a global variable (similar to efi_mm) to save and restore the
correct CR4.LASS state. The runtime calls are serialized with the
efi_runtime_lock, so no concurrency issues are expected.

Signed-off-by: Sohil Mehta <sohil.mehta@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Tested-by: Tony Luck <tony.luck@intel.com>
Tested-by: Maciej Wieczor-Retman <maciej.wieczor-retman@intel.com>
Link: https://patch.msgid.link/20260120234730.2215498-3-sohil.mehta@intel.com
2026-03-03 09:49:45 -08:00
Mike Rapoport (Microsoft)
a4b0bf6a40 x86/efi: defer freeing of boot services memory
efi_free_boot_services() frees memory occupied by EFI_BOOT_SERVICES_CODE
and EFI_BOOT_SERVICES_DATA using memblock_free_late().

There are two issue with that: memblock_free_late() should be used for
memory allocated with memblock_alloc() while the memory reserved with
memblock_reserve() should be freed with free_reserved_area().

More acutely, with CONFIG_DEFERRED_STRUCT_PAGE_INIT=y
efi_free_boot_services() is called before deferred initialization of the
memory map is complete.

Benjamin Herrenschmidt reports that this causes a leak of ~140MB of
RAM on EC2 t3a.nano instances which only have 512MB or RAM.

If the freed memory resides in the areas that memory map for them is
still uninitialized, they won't be actually freed because
memblock_free_late() calls memblock_free_pages() and the latter skips
uninitialized pages.

Using free_reserved_area() at this point is also problematic because
__free_page() accesses the buddy of the freed page and that again might
end up in uninitialized part of the memory map.

Delaying the entire efi_free_boot_services() could be problematic
because in addition to freeing boot services memory it updates
efi.memmap without any synchronization and that's undesirable late in
boot when there is concurrency.

More robust approach is to only defer freeing of the EFI boot services
memory.

Split efi_free_boot_services() in two. First efi_unmap_boot_services()
collects ranges that should be freed into an array then
efi_free_boot_services() later frees them after deferred init is complete.

Link: https://lore.kernel.org/all/ec2aaef14783869b3be6e3c253b2dcbf67dbc12a.camel@kernel.crashing.org
Fixes: 916f676f8d ("x86, efi: Retain boot service code until after switching to virtual mode")
Cc: <stable@vger.kernel.org>
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2026-02-25 12:02:48 +01:00
Linus Torvalds
bf4afc53b7 Convert 'alloc_obj' family to use the new default GFP_KERNEL argument
This was done entirely with mindless brute force, using

    git grep -l '\<k[vmz]*alloc_objs*(.*, GFP_KERNEL)' |
        xargs sed -i 's/\(alloc_objs*(.*\), GFP_KERNEL)/\1)/'

to convert the new alloc_obj() users that had a simple GFP_KERNEL
argument to just drop that argument.

Note that due to the extreme simplicity of the scripting, any slightly
more complex cases spread over multiple lines would not be triggered:
they definitely exist, but this covers the vast bulk of the cases, and
the resulting diff is also then easier to check automatically.

For the same reason the 'flex' versions will be done as a separate
conversion.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2026-02-21 17:09:51 -08:00
Kees Cook
69050f8d6d treewide: Replace kmalloc with kmalloc_obj for non-scalar types
This is the result of running the Coccinelle script from
scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to
avoid scalar types (which need careful case-by-case checking), and
instead replace kmalloc-family calls that allocate struct or union
object instances:

Single allocations:	kmalloc(sizeof(TYPE), ...)
are replaced with:	kmalloc_obj(TYPE, ...)

Array allocations:	kmalloc_array(COUNT, sizeof(TYPE), ...)
are replaced with:	kmalloc_objs(TYPE, COUNT, ...)

Flex array allocations:	kmalloc(struct_size(PTR, FAM, COUNT), ...)
are replaced with:	kmalloc_flex(*PTR, FAM, COUNT, ...)

(where TYPE may also be *VAR)

The resulting allocations no longer return "void *", instead returning
"TYPE *".

Signed-off-by: Kees Cook <kees@kernel.org>
2026-02-21 01:02:28 -08:00
Ingo Molnar
4ad03f133c x86/boot/e820: Simplify the e820__range_remove() API
Right now e820__range_remove() has two parameters to control the
E820 type of the range removed:

	extern void e820__range_remove(u64 start, u64 size, enum e820_type old_type, bool check_type);

Since E820 types start at 1, zero has a natural meaning of 'no type.

Consolidate the (old_type,check_type) parameters into a single (filter_type)
parameter:

	extern void e820__range_remove(u64 start, u64 size, enum e820_type filter_type);

Note that both e820__mapped_raw_any() and e820__mapped_any()
already have such semantics for their 'type' parameter, although
it's currently not used with '0' by in-kernel code.

Also, the __e820__mapped_all() internal helper already has such
semantics implemented as well, and the e820__get_entry_type() API
uses the '0' type to such effect.

This simplifies not just e820__range_remove(), and synchronizes its
use of type filters with other E820 API functions, but simplifies
usage sites as well, such as parse_memmap_one(), beyond the reduction
of the number of parameters:

  -               else if (from)
  -                       e820__range_remove(start_at, mem_size, from, 1);
                  else
  -                       e820__range_remove(start_at, mem_size, 0, 0);
  +                       e820__range_remove(start_at, mem_size, from);

The generated code gets smaller as well:

	add/remove: 0/0 grow/shrink: 0/5 up/down: 0/-66 (-66)

	Function                                     old     new   delta
	parse_memopt                                 112     107      -5
	efi_init                                    1048    1039      -9
	setup_arch                                  2719    2709     -10
	e820__range_remove                           283     273     -10
	parse_memmap_opt                             559     527     -32

	Total: Before=22,675,600, After=22,675,534, chg -0.00%

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: H . Peter Anvin <hpa@zytor.com>
Cc: Andy Shevchenko <andy@kernel.org>
Cc: Arnd Bergmann <arnd@kernel.org>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Juergen Gross <jgross@suse.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Paul Menzel <pmenzel@molgen.mpg.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://patch.msgid.link/20250515120549.2820541-28-mingo@kernel.org
2025-12-14 09:19:42 +01:00
Linus Torvalds
9591fdb061 - Remove a bunch of asm implementing condition flags testing in KVM's
emulator in favor of int3_emulate_jcc() which is written in C
 
 - Replace KVM fastops with C-based stubs which avoids problems with the
   fastop infra related to latter not adhering to the C ABI due to their
   special calling convention and, more importantly, bypassing compiler
   control-flow integrity checking because they're written in asm
 
 - Remove wrongly used static branches and other ugliness accumulated
   over time in hyperv's hypercall implementation with a proper static
   function call to the correct hypervisor call variant
 
 - Add some fixes and modifications to allow running FRED-enabled kernels
   in KVM even on non-FRED hardware
 
 - Add kCFI improvements like validating indirect calls and prepare for
   enabling kCFI with GCC. Add cmdline params documentation and other
   code cleanups
 
 - Use the single-byte 0xd6 insn as the official #UD single-byte
   undefined opcode instruction as agreed upon by both x86 vendors
 
 - Other smaller cleanups and touchups all over the place
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Merge tag 'x86_core_for_v6.18_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull more x86 updates from Borislav Petkov:

 - Remove a bunch of asm implementing condition flags testing in KVM's
   emulator in favor of int3_emulate_jcc() which is written in C

 - Replace KVM fastops with C-based stubs which avoids problems with the
   fastop infra related to latter not adhering to the C ABI due to their
   special calling convention and, more importantly, bypassing compiler
   control-flow integrity checking because they're written in asm

 - Remove wrongly used static branches and other ugliness accumulated
   over time in hyperv's hypercall implementation with a proper static
   function call to the correct hypervisor call variant

 - Add some fixes and modifications to allow running FRED-enabled
   kernels in KVM even on non-FRED hardware

 - Add kCFI improvements like validating indirect calls and prepare for
   enabling kCFI with GCC. Add cmdline params documentation and other
   code cleanups

 - Use the single-byte 0xd6 insn as the official #UD single-byte
   undefined opcode instruction as agreed upon by both x86 vendors

 - Other smaller cleanups and touchups all over the place

* tag 'x86_core_for_v6.18_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits)
  x86,retpoline: Optimize patch_retpoline()
  x86,ibt: Use UDB instead of 0xEA
  x86/cfi: Remove __noinitretpoline and __noretpoline
  x86/cfi: Add "debug" option to "cfi=" bootparam
  x86/cfi: Standardize on common "CFI:" prefix for CFI reports
  x86/cfi: Document the "cfi=" bootparam options
  x86/traps: Clarify KCFI instruction layout
  compiler_types.h: Move __nocfi out of compiler-specific header
  objtool: Validate kCFI calls
  x86/fred: KVM: VMX: Always use FRED for IRQs when CONFIG_X86_FRED=y
  x86/fred: Play nice with invoking asm_fred_entry_from_kvm() on non-FRED hardware
  x86/fred: Install system vector handlers even if FRED isn't fully enabled
  x86/hyperv: Use direct call to hypercall-page
  x86/hyperv: Clean up hv_do_hypercall()
  KVM: x86: Remove fastops
  KVM: x86: Convert em_salc() to C
  KVM: x86: Introduce EM_ASM_3WCL
  KVM: x86: Introduce EM_ASM_1SRC2
  KVM: x86: Introduce EM_ASM_2CL
  KVM: x86: Introduce EM_ASM_2W
  ...
2025-10-11 11:19:16 -07:00
Vishal Moola (Oracle)
b45ef93701 x86: stop calling page_address() in free_pages()
free_pages() should be used when we only have a virtual address.  We
should call __free_pages() directly on our page instead.

Link: https://lkml.kernel.org/r/20250903185921.1785167-4-vishal.moola@gmail.com
Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Justin Sanders <justin@coraid.com>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Cc: SeongJae Park <sj@kernel.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-09-21 14:22:17 -07:00
Peter Zijlstra
894af4a1cd objtool: Validate kCFI calls
Validate that all indirect calls adhere to kCFI rules. Notably doing
nocfi indirect call to a cfi function is broken.

Apparently some Rust 'core' code violates this and explodes when ran
with FineIBT.

All the ANNOTATE_NOCFI_SYM sites are prime targets for attackers.

 - runtime EFI is especially henous because it also needs to disable
   IBT. Basically calling unknown code without CFI protection at
   runtime is a massice security issue.

 - Kexec image handover; if you can exploit this, you get to keep it :-)

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Acked-by: Sean Christopherson <seanjc@google.com>
Link: https://lkml.kernel.org/r/20250714103441.496787279@infradead.org
2025-08-18 14:23:09 +02:00
Gerd Hoffmann
a7549636f6 x86/sev: Let sev_es_efi_map_ghcbs() map the CA pages too
OVMF EFI firmware needs access to the CA page to do SVSM protocol calls. For
example, when the SVSM implements an EFI variable store, such calls will be
necessary.

So add that to sev_es_efi_map_ghcbs() and also rename the function to reflect
the additional job it is doing now.

  [ bp: Massage. ]

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/20250626114014.373748-4-kraxel@redhat.com
2025-06-27 14:07:10 +02:00
Ingo Molnar
11d8f542d9 Merge branch 'x86/alternatives' into x86/core, to merge dependent commits
Prepare to resolve conflicts with an upstream series of fixes that conflict
with pending x86 changes:

  6f5bf947ba Merge tag 'its-for-linus-20250509' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2025-05-13 10:33:41 +02:00
Peter Zijlstra
7f9958230d x86/mm: Fix false positive warning in switch_mm_irqs_off()
Multiple testers reported the following new warning:

	WARNING: CPU: 0 PID: 0 at arch/x86/mm/tlb.c:795

Which corresponds to:

	if (IS_ENABLED(CONFIG_DEBUG_VM) && WARN_ON_ONCE(prev != &init_mm &&
	    !cpumask_test_cpu(cpu, mm_cpumask(next))))
		cpumask_set_cpu(cpu, mm_cpumask(next));

So the problem is that unuse_temporary_mm() explicitly clears
that bit; and it has to, because otherwise the flush_tlb_mm_range() in
__text_poke() will try sending IPIs, which are not at all needed.

See also:

   https://lore.kernel.org/all/20241113095550.GBZzR3pg-RhJKPDazS@fat_crate.local/

Notably, the whole {,un}use_temporary_mm() thing requires preemption to
be disabled across it with the express purpose of keeping all TLB
nonsense CPU local, such that invalidations can also stay local etc.

However, as a side-effect, we violate this above WARN(), which sorta
makes sense for the normal case, but very much doesn't make sense here.

Change unuse_temporary_mm() to mark the mm_struct such that a further
exception (beyond init_mm) can be grafted, to keep the warning for all
the other cases.

Reported-by: Chaitanya Kumar Borah <chaitanya.kumar.borah@intel.com>
Reported-by: Jani Nikula <jani.nikula@linux.intel.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Andrew Cooper <andrew.cooper3@citrix.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Rik van Riel <riel@surriel.com>
Link: https://lore.kernel.org/r/20250430081154.GH4439@noisy.programming.kicks-ass.net
2025-05-06 11:28:57 +02:00
Juergen Gross
4ce385f564 x86/mm: Fix _pgd_alloc() for Xen PV mode
Recently _pgd_alloc() was switched from using __get_free_pages() to
pagetable_alloc_noprof(), which might return a compound page in case
the allocation order is larger than 0.

On x86 this will be the case if CONFIG_MITIGATION_PAGE_TABLE_ISOLATION
is set, even if PTI has been disabled at runtime.

When running as a Xen PV guest (this will always disable PTI), using
a compound page for a PGD will result in VM_BUG_ON_PGFLAGS being
triggered when the Xen code tries to pin the PGD.

Fix the Xen issue together with the not needed 8k allocation for a
PGD with PTI disabled by replacing PGD_ALLOCATION_ORDER with an
inline helper returning the needed order for PGD allocations.

Fixes: a9b3c355c2 ("asm-generic: pgalloc: provide generic __pgd_{alloc,free}")
Reported-by: Petr Vaněk <arkamar@atlas.cz>
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Tested-by: Petr Vaněk <arkamar@atlas.cz>
Cc:stable@vger.kernel.org
Link: https://lore.kernel.org/all/20250422131717.25724-1-jgross%40suse.com
2025-04-23 07:49:14 -07:00
Andy Lutomirski
e7021e2fe0 x86/efi: Make efi_enter/leave_mm() use the use_/unuse_temporary_mm() machinery
This should be considerably more robust.  It's also necessary for optimized
for_each_possible_lazymm_cpu() on x86 -- without this patch, EFI calls in
lazy context would remove the lazy mm from mm_cpumask().

[ mingo: Merged it on top of x86/alternatives ]

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://lore.kernel.org/r/20250402094540.3586683-7-mingo@kernel.org
2025-04-12 10:06:04 +02:00
Dave Young
64b45dd46e x86/efi: skip memattr table on kexec boot
efi_memattr_init() added a sanity check to avoid firmware caused corruption.
The check is based on efi memmap entry numbers, but kexec only takes the
runtime related memmap entries thus this caused many false warnings, see
below thread for details:

https://lore.kernel.org/all/20250108215957.3437660-2-usamaarif642@gmail.com/

Ard suggests to skip the efi memattr table in kexec, this makes sense because
those memattr fixups are not critical.

Fixes: 8fbe4c49c0 ("efi/memattr: Ignore table if the size is clearly bogus")
Cc: <stable@vger.kernel.org> # v6.13+
Reported-by: Breno Leitao <leitao@debian.org>
Reported-and-tested-by: Usama Arif <usamaarif642@gmail.com>
Suggested-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Dave Young <dyoung@redhat.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2025-01-23 09:58:43 +01:00
Ard Biesheuvel
144d52dd8f x86/efistub: Drop long obsolete UGA support
UGA is the EFI graphical output protocol that preceded GOP, and has been
long obsolete. Drop support for it from the x86 implementation of the
EFI stub - other architectures never bothered to implement it (save for
ia64)

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2025-01-14 08:34:24 +01:00
Linus Torvalds
18a411cc5d EFI updates for v6.13
- Align handling of the compiled-in command line with the core kernel
 
 - Measure the initrd into the TPM also when it was loaded via the EFI
   file I/O protocols
 
 - Clean up TPM event log handling
 
 - Sanity check the EFI memory attributes table, and apply it after kexec
   too
 
 - Assorted other fixes
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Merge tag 'efi-next-for-v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi

Pull EFI updates from Ard Biesheuvel:
 "Just some cleanups and bug fixes this time around:

   - Align handling of the compiled-in command line with the core kernel

   - Measure the initrd into the TPM also when it was loaded via the EFI
     file I/O protocols

   - Clean up TPM event log handling

   - Sanity check the EFI memory attributes table, and apply it after
     kexec too

   - Assorted other fixes"

* tag 'efi-next-for-v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi:
  efi: Fix memory leak in efivar_ssdt_load
  efi/libstub: Take command line overrides into account for loaded files
  efi/libstub: Fix command line fallback handling when loading files
  efi/libstub: Parse builtin command line after bootloader provided one
  x86/efi: Apply EFI Memory Attributes after kexec
  x86/efi: Drop support for the EFI_PROPERTIES_TABLE
  efi/memattr: Ignore table if the size is clearly bogus
  efi/zboot: Fix outdated comment about using LoadImage/StartImage
  efi/libstub: Free correct pointer on failure
  libstub,tpm: do not ignore failure case when reading final event log
  tpm: fix unsigned/signed mismatch errors related to __calc_tpm2_event_size
  tpm: do not ignore memblock_reserve return value
  tpm: fix signed/unsigned bug when checking event logs
  efi/libstub: measure initrd to PCR9 independent of source
  efi/libstub: remove unnecessary cmd_line_len from efi_convert_cmdline()
  efi/libstub: fix efi_parse_options() ignoring the default command line
2024-11-20 14:13:28 -08:00
Nicolas Saenz Julienne
21b1a7f7ae x86/efi: Apply EFI Memory Attributes after kexec
Kexec bypasses EFI's switch to virtual mode. In exchange, it has its own
routine, kexec_enter_virtual_mode(), which replays the mappings made by
the original kernel. Unfortunately, that function fails to reinstate
EFI's memory attributes, which would've otherwise been set after
entering virtual mode. Remediate this by calling
efi_runtime_update_mappings() within kexec's routine.

Signed-off-by: Nicolas Saenz Julienne <nsaenz@amazon.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2024-11-15 17:40:00 +01:00
Nicolas Saenz Julienne
7eb4e1dd71 x86/efi: Drop support for the EFI_PROPERTIES_TABLE
Drop support for the EFI_PROPERTIES_TABLE. It was a failed, short-lived
experiment that broke the boot both on Linux and Windows, and was
replaced by the EFI_MEMORY_ATTRIBUTES_TABLE shortly after.

Suggested-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Nicolas Saenz Julienne <nsaenz@amazon.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2024-11-15 17:40:00 +01:00
Tony Luck
110213b8f0 x86/cpu: Fix FAM5_QUARK_X1000 to use X86_MATCH_VFM()
This family 5 CPU escaped notice when cleaning up all the family 6
CPUs.

Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://lore.kernel.org/all/20241031185733.17327-1-tony.luck%40intel.com
2024-10-31 12:02:21 -07:00
Ard Biesheuvel
37aee82c21 x86/efi: Drop support for fake EFI memory maps
Between kexec and confidential VM support, handling the EFI memory maps
correctly on x86 is already proving to be rather difficult (as opposed
to other EFI architectures which manage to never modify the EFI memory
map to begin with)

EFI fake memory map support is essentially a development hack (for
testing new support for the 'special purpose' and 'more reliable' EFI
memory attributes) that leaked into production code. The regions marked
in this manner are not actually recognized as such by the firmware
itself or the EFI stub (and never have), and marking memory as 'more
reliable' seems rather futile if the underlying memory is just ordinary
RAM.

Marking memory as 'special purpose' in this way is also dubious, but may
be in use in production code nonetheless. However, the same should be
achievable by using the memmap= command line option with the ! operator.

EFI fake memmap support is not enabled by any of the major distros
(Debian, Fedora, SUSE, Ubuntu) and does not exist on other
architectures, so let's drop support for it.

Acked-by: Borislav Petkov (AMD) <bp@alien8.de>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2024-07-02 00:26:24 +02:00
Ard Biesheuvel
75dde792d6 efi/x86: Free EFI memory map only when installing a new one.
The logic in __efi_memmap_init() is shared between two different
execution flows:
- mapping the EFI memory map early or late into the kernel VA space, so
  that its entries can be accessed;
- the x86 specific cloning of the EFI memory map in order to insert new
  entries that are created as a result of making a memory reservation
  via a call to efi_mem_reserve().

In the former case, the underlying memory containing the kernel's view
of the EFI memory map (which may be heavily modified by the kernel
itself on x86) is not modified at all, and the only thing that changes
is the virtual mapping of this memory, which is different between early
and late boot.

In the latter case, an entirely new allocation is created that carries a
new, updated version of the kernel's view of the EFI memory map. When
installing this new version, the old version will no longer be
referenced, and if the memory was allocated by the kernel, it will leak
unless it gets freed.

The logic that implements this freeing currently lives on the code path
that is shared between these two use cases, but it should only apply to
the latter. So move it to the correct spot.

While at it, drop the dummy definition for non-x86 architectures, as
that is no longer needed.

Cc: <stable@vger.kernel.org>
Fixes: f0ef652347 ("efi: Fix efi_memmap_alloc() leaks")
Tested-by: Ashish Kalra <Ashish.Kalra@amd.com>
Link: https://lore.kernel.org/all/36ad5079-4326-45ed-85f6-928ff76483d3@amd.com
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2024-06-15 10:25:02 +02:00
Thomas Zimmermann
785ddc8b6b x86/efi: Implement arch_ima_efi_boot_mode() in source file
The x86 implementation of arch_ima_efi_boot_mode() uses the global
boot_param state. Move it into a source file to clean up the header.
Avoid potential rebuilds of unrelated source files if boot_params
changes.

Suggested-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20240112095000.8952-4-tzimmermann@suse.de
2024-01-30 15:17:17 +01:00
Ard Biesheuvel
762f169f5d efi/x86: Move EFI runtime call setup/teardown helpers out of line
Only the arch_efi_call_virt() macro that some architectures override
needs to be a macro, given that it is variadic and encapsulates calls
via function pointers that have different prototypes.

The associated setup and teardown code are not special in this regard,
and don't need to be instantiated at each call site. So turn them into
ordinary C functions and move them out of line.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2023-09-11 06:37:50 +00:00
Zhu Wang
92faa821bb efi: memmap: Remove kernel-doc warnings
Remove kernel-doc warnings:

arch/x86/platform/efi/memmap.c:94: warning: Function parameter or member
'data' not described in 'efi_memmap_install'
arch/x86/platform/efi/memmap.c:94: warning: Excess function parameter
'ctx' description in 'efi_memmap_install'

Signed-off-by: Zhu Wang <wangzhu9@huawei.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2023-08-03 15:39:57 +02:00
Linus Torvalds
f8566aa4f1 A single regression fix for x86:
Moving the invocation of arch_cpu_finalize_init() earlier in the boot
   process caused a boot regression on IBT enabled system.
 
   The root cause is not the move of arch_cpu_finalize_init() itself. The
   system fails to boot because the subsequent efi_enter_virtual_mode() code
   has a non-IBT safe EFI call inside. This was never noticed because IBT
   was enabled after the EFI initialization.
 
   Switching the EFI call to use the IBT safe wrapper cures the problem.
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Merge tag 'x86-urgent-2023-07-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 fix from Thomas Gleixner:
 "A single regression fix for x86:

  Moving the invocation of arch_cpu_finalize_init() earlier in the boot
  process caused a boot regression on IBT enabled system.

  The root cause is not the move of arch_cpu_finalize_init() itself. The
  system fails to boot because the subsequent efi_enter_virtual_mode()
  code has a non-IBT safe EFI call inside. This was not noticed before
  because IBT was enabled after the EFI initialization.

  Switching the EFI call to use the IBT safe wrapper cures the problem"

* tag 'x86-urgent-2023-07-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/efi: Make efi_set_virtual_address_map IBT safe
2023-07-01 11:40:01 -07:00
Linus Torvalds
937d96d2d5 EFI updates for v6.5
Although some more stuff is brewing, the EFI changes that are ready for
 mainline are few, so not a lot to pull this cycle:
 
 - improve the PCI DMA paranoia logic in the EFI stub
 - some constification changes
 - add statfs support to efivarfs
 - allow user space to enumerate updatable firmware resources without
   CAP_SYS_ADMIN
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Merge tag 'efi-next-for-v6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi

Pull EFI updates from Ard Biesheuvel:
 "Although some more stuff is brewing, the EFI changes that are ready
  for mainline are few this cycle:

   - improve the PCI DMA paranoia logic in the EFI stub

   - some constification changes

   - add statfs support to efivarfs

   - allow user space to enumerate updatable firmware resources without
     CAP_SYS_ADMIN"

* tag 'efi-next-for-v6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi:
  efi/libstub: Disable PCI DMA before grabbing the EFI memory map
  efi/esrt: Allow ESRT access without CAP_SYS_ADMIN
  efivarfs: expose used and total size
  efi: make kobj_type structure constant
  efi: x86: make kobj_type structure constant
2023-06-30 21:35:52 -07:00
Thomas Gleixner
0303c9729a x86/efi: Make efi_set_virtual_address_map IBT safe
Niklāvs reported a boot regression on an Alderlake machine and bisected it
to commit 9df9d2f047 ("init: Invoke arch_cpu_finalize_init() earlier").

By moving the invocation of arch_cpu_finalize_init() further down he
identified that efi_enter_virtual_mode() is the function which causes the
boot hang.

The main difference of the earlier invocation is that the boot CPU is
already fully initialized and mitigations and alternatives are applied.

But the only really interesting change turned out to be IBT, which is now
enabled before efi_enter_virtual_mode(). "ibt=off" on the kernel command
line cured the problem.

Inspection of the involved calls in efi_enter_virtual_mode() unearthed that
efi_set_virtual_address_map() is the only place in the kernel which invokes
an EFI call without the IBT safe wrapper. This went obviously unnoticed so
far as IBT was enabled later.

Use arch_efi_call_virt() instead of efi_call() to cure that.

Fixes: fe379fa4d1 ("x86/ibt: Disable IBT around firmware")
Fixes: 9df9d2f047 ("init: Invoke arch_cpu_finalize_init() earlier")
Reported-by: Niklāvs Koļesņikovs <pinkflames.linux@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=217602
Link: https://lore.kernel.org/r/87jzvm12q0.ffs@tglx
2023-06-30 15:26:24 +02:00
Kirill A. Shutemov
2053bc57f3 efi: Add unaccepted memory support
efi_config_parse_tables() reserves memory that holds unaccepted memory
configuration table so it won't be reused by page allocator.

Core-mm requires few helpers to support unaccepted memory:

 - accept_memory() checks the range of addresses against the bitmap and
   accept memory if needed.

 - range_contains_unaccepted_memory() checks if anything within the
   range requires acceptance.

Architectural code has to provide efi_get_unaccepted_table() that
returns pointer to the unaccepted memory configuration table.

arch_accept_memory() handles arch-specific part of memory acceptance.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Link: https://lore.kernel.org/r/20230606142637.5171-6-kirill.shutemov@linux.intel.com
2023-06-06 17:22:20 +02:00
Anisse Astier
d86ff3333c efivarfs: expose used and total size
When writing EFI variables, one might get errors with no other message
on why it fails. Being able to see how much is used by EFI variables
helps analyzing such issues.

Since this is not a conventional filesystem, block size is intentionally
set to 1 instead of PAGE_SIZE.

x86 quirks of reserved size are taken into account; so that available
and free size can be different, further helping debugging space issues.

With this patch, one can see the remaining space in EFI variable storage
via efivarfs, like this:

   $ df -h /sys/firmware/efi/efivars/
   Filesystem      Size  Used Avail Use% Mounted on
   efivarfs        176K  106K   66K  62% /sys/firmware/efi/efivars

Signed-off-by: Anisse Astier <an.astier@criteo.com>
[ardb: - rename efi_reserved_space() to efivar_reserved_space()
       - whitespace/coding style tweaks]
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2023-05-17 18:21:34 +02:00
Thomas Weißschuh
42a8af0fa4 efi: x86: make kobj_type structure constant
Since commit ee6d3dd4ed ("driver core: make kobj_type constant.")
the driver core allows the usage of const struct kobj_type.

Take advantage of this to constify the structure definition to prevent
modification at runtime.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2023-05-10 19:00:40 +02:00
Ard Biesheuvel
93be2859e2 efi: x86: Wire up IBT annotation in memory attributes table
UEFI v2.10 extends the EFI memory attributes table with a flag that
indicates whether or not all RuntimeServicesCode regions were
constructed with ENDBR landing pads, permitting the OS to map these
regions with IBT restrictions enabled.

So let's take this into account on x86 as well.

Suggested-by: Peter Zijlstra <peterz@infradead.org> # ibt_save() changes
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2023-02-09 19:30:54 +01:00
Ard Biesheuvel
cf1d2ffcc6 efi: Discover BTI support in runtime services regions
Add the generic plumbing to detect whether or not the runtime code
regions were constructed with BTI/IBT landing pads by the firmware,
permitting the OS to enable enforcement when mapping these regions into
the OS's address space.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
2023-02-04 09:19:02 +01:00
Ard Biesheuvel
234fa51db9 efi: Drop minimum EFI version check at boot
We currently pass a minimum major version to the generic EFI helper that
checks the system table magic and version, and refuse to boot if the
value is lower.

The motivation for this check is unknown, and even the code that uses
major version 2 as the minimum (ARM, arm64 and RISC-V) should make it
past this check without problems, and boot to a point where we have
access to a console or some other means to inform the user that the
firmware's major revision number made us unhappy. (Revision 2.0 of the
UEFI specification was released in January 2006, whereas ARM, arm64 and
RISC-V support where added in 2009, 2013 and 2017, respectively, so
checking for major version 2 or higher is completely arbitrary)

So just drop the check.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2023-02-03 18:01:07 +01:00
Linus Torvalds
c7020e1b34 pci-v6.2-changes
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Merge tag 'pci-v6.2-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci

Pull PCI updates from Bjorn Helgaas:
 "Enumeration:

   - Squash portdrv_{core,pci}.c into portdrv.c to ease maintenance and
     make more things static.

   - Make portdrv bind to Switch Ports that have AER. Previously, if
     these Ports lacked MSI/MSI-X, portdrv failed to bind, which meant
     the Ports couldn't be suspended to low-power states. AER on these
     Ports doesn't use interrupts, and the AER driver doesn't need to
     claim them.

   - Assign PCI domain IDs using ida_alloc(), which makes host bridge
     add/remove work better.

  Resource management:

   - To work better with recent BIOSes that use EfiMemoryMappedIO for
     PCI host bridge apertures, remove those regions from the E820 map
     (E820 entries normally prevent us from allocating BARs). In v5.19,
     we added some quirks to disable E820 checking, but that's not very
     maintainable. EfiMemoryMappedIO means the OS needs to map the
     region for use by EFI runtime services; it shouldn't prevent OS
     from using it.

  PCIe native device hotplug:

   - Build pciehp by default if USB4 is enabled, since Thunderbolt/USB4
     PCIe tunneling depends on native PCIe hotplug.

   - Enable Command Completed Interrupt only if supported to avoid user
     confusion from lspci output that says this is enabled but not
     supported.

   - Prevent pciehp from binding to Switch Upstream Ports; this happened
     because of interaction with acpiphp and caused devices below the
     Upstream Port to disappear.

  Power management:

   - Convert AGP drivers to generic power management. We hope to remove
     legacy power management from the PCI core eventually.

  Virtualization:

   - Fix pci_device_is_present(), which previously always returned
     "false" for VFs, causing virtio hangs when unbinding the driver.

  Miscellaneous:

   - Convert drivers to gpiod API to prepare for dropping some legacy
     code.

   - Fix DOE fencepost error for the maximum data object length.

  Baikal-T1 PCIe controller driver:

   - Add driver and DT bindings.

  Broadcom STB PCIe controller driver:

   - Enable Multi-MSI.

   - Delay 100ms after PERST# deassert to allow power and clocks to
     stabilize.

   - Configure Read Completion Boundary to 64 bytes.

  Freescale i.MX6 PCIe controller driver:

   - Initialize PHY before deasserting core reset to fix a regression in
     v6.0 on boards where the PHY provides the reference.

   - Fix imx6sx and imx8mq clock names in DT schema.

  Intel VMD host bridge driver:

   - Fix Secondary Bus Reset on VMD bridges, which allows reset of NVMe
     SSDs in VT-d pass-through scenarios.

   - Disable MSI remapping, which gets re-enabled by firmware during
     suspend/resume.

  MediaTek PCIe Gen3 controller driver:

   - Add MT7986 and MT8195 support.

  Qualcomm PCIe controller driver:

   - Add SC8280XP/SA8540P basic interconnect support.

  Rockchip DesignWare PCIe controller driver:

   - Base DT schema on common Synopsys schema.

  Synopsys DesignWare PCIe core:

   - Collect DT items shared between Root Port and Endpoint (PERST GPIO,
     PHY info, clocks, resets, link speed, number of lanes, number of
     iATU windows, interrupt info, etc) to snps,dw-pcie-common.yaml.

   - Add dma-ranges support for Root Ports and Endpoints.

   - Consolidate DT resource retrieval for "dbi", "dbi2", "atu", etc. to
     reduce code duplication.

   - Add generic names for clocks and resets to encourage more
     consistent naming across drivers using DesignWare IP.

   - Stop advertising PTM Responder role for Endpoints, which aren't
     allowed to be responders.

  TI J721E PCIe driver:

   - Add j721s2 host mode ID to DT schema.

   - Add interrupt properties to DT schema.

  Toshiba Visconti PCIe controller driver:

   - Fix interrupts array max constraints in DT schema"

* tag 'pci-v6.2-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (95 commits)
  x86/PCI: Use pr_info() when possible
  x86/PCI: Fix log message typo
  x86/PCI: Tidy E820 removal messages
  PCI: Skip allocate_resource() if too little space available
  efi/x86: Remove EfiMemoryMappedIO from E820 map
  PCI/portdrv: Allow AER service only for Root Ports & RCECs
  PCI: xilinx-nwl: Fix coding style violations
  PCI: mvebu: Switch to using gpiod API
  PCI: pciehp: Enable Command Completed Interrupt only if supported
  PCI: aardvark: Switch to using devm_gpiod_get_optional()
  dt-bindings: PCI: mediatek-gen3: add support for mt7986
  dt-bindings: PCI: mediatek-gen3: add SoC based clock config
  dt-bindings: PCI: qcom: Allow 'dma-coherent' property
  PCI: mt7621: Add sentinel to quirks table
  PCI: vmd: Fix secondary bus reset for Intel bridges
  PCI: endpoint: pci-epf-vntb: Fix sparse ntb->reg build warning
  PCI: endpoint: pci-epf-vntb: Fix sparse build warning for epf_db
  PCI: endpoint: pci-epf-vntb: Replace hardcoded 4 with sizeof(u32)
  PCI: endpoint: pci-epf-vntb: Remove unused epf_db_phy struct member
  PCI: endpoint: pci-epf-vntb: Fix call pci_epc_mem_free_addr() in error path
  ...
2022-12-14 09:54:10 -08:00
Bjorn Helgaas
07eab0901e efi/x86: Remove EfiMemoryMappedIO from E820 map
Firmware can use EfiMemoryMappedIO to request that MMIO regions be mapped
by the OS so they can be accessed by EFI runtime services, but should have
no other significance to the OS (UEFI r2.10, sec 7.2).  However, most
bootloaders and EFI stubs convert EfiMemoryMappedIO regions to
E820_TYPE_RESERVED entries, which prevent Linux from allocating space from
them (see remove_e820_regions()).

Some platforms use EfiMemoryMappedIO entries for PCI MMCONFIG space and PCI
host bridge windows, which means Linux can't allocate BAR space for
hot-added devices.

Remove large EfiMemoryMappedIO regions from the E820 map to avoid this
problem.

Leave small (< 256KB) EfiMemoryMappedIO regions alone because on some
platforms, these describe non-window space that's included in host bridge
_CRS.  If we assign that space to PCI devices, they don't work.  On the
Lenovo X1 Carbon, this leads to suspend/resume failures.

The previous solution to the problem of allocating BARs in these regions
was to add pci_crs_quirks[] entries to disable E820 checking for these
machines (see d341838d77 ("x86/PCI: Disable E820 reserved region clipping
via quirks")):

  Acer   DMI_PRODUCT_NAME    Spin SP513-54N
  Clevo  DMI_BOARD_NAME      X170KM-G
  Lenovo DMI_PRODUCT_VERSION *IIL*

Florent reported the BAR allocation issue on the Clevo NL4XLU.  We could
add another quirk for the NL4XLU, but I hope this generic change can solve
it for many machines without having to add quirks.

This change has been tested on Clevo X170KM-G (Konrad) and Lenovo Ideapad
Slim 3 (Matt) and solves the problem even when overriding the existing
quirks by booting with "pci=use_e820".

Link: https://bugzilla.kernel.org/show_bug.cgi?id=216565     Clevo NL4XLU
Link: https://bugzilla.kernel.org/show_bug.cgi?id=206459#c78 Clevo X170KM-G
Link: https://bugzilla.redhat.com/show_bug.cgi?id=1868899    Ideapad Slim 3
Link: https://bugzilla.redhat.com/show_bug.cgi?id=2029207    X1 Carbon
Link: https://lore.kernel.org/r/20221208190341.1560157-2-helgaas@kernel.org
Reported-by: Florent DELAHAYE <kernelorg@undead.fr>
Tested-by: Konrad J Hambrick <kjhambrick@gmail.com>
Tested-by: Matt Hansen <2lprbe78@duck.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Hans de Goede <hdegoede@redhat.com>
2022-12-10 10:31:42 -06:00
Ard Biesheuvel
1fff234de2 efi: x86: Move EFI runtime map sysfs code to arch/x86
The EFI runtime map code is only wired up on x86, which is the only
architecture that has a need for it in its implementation of kexec.

So let's move this code under arch/x86 and drop all references to it
from generic code. To ensure that the efi_runtime_map_init() is invoked
at the appropriate time use a 'sync' subsys_initcall() that will be
called right after the EFI initcall made from generic code where the
original invocation of efi_runtime_map_init() resided.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Dave Young <dyoung@redhat.com>
2022-11-18 09:14:09 +01:00
Ard Biesheuvel
d85e3e3494 efi: xen: Set EFI_PARAVIRT for Xen dom0 boot on all architectures
Currently, the EFI_PARAVIRT flag is only used by Xen dom0 boot on x86,
even though other architectures also support pseudo-EFI boot, where the
core kernel is invoked directly and provided with a set of data tables
that resemble the ones constructed by the EFI stub, which never actually
runs in that case.

Let's fix this inconsistency, and always set this flag when booting dom0
via the EFI boot path. Note that Xen on x86 does not provide the EFI
memory map in this case, whereas other architectures do, so move the
associated EFI_PARAVIRT check into the x86 platform code.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-11-18 09:14:09 +01:00
Ard Biesheuvel
fdc6d38d64 efi: memmap: Move manipulation routines into x86 arch tree
The EFI memory map is a description of the memory layout as provided by
the firmware, and only x86 manipulates it in various different ways for
its own memory bookkeeping. So let's move the memmap routines that are
only used by x86 into the x86 arch tree.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-11-18 09:14:09 +01:00
Ard Biesheuvel
4059ba656c efi: memmap: Move EFI fake memmap support into x86 arch tree
The EFI fake memmap support is specific to x86, which manipulates the
EFI memory map in various different ways after receiving it from the EFI
stub. On other architectures, we have managed to push back on this, and
the EFI memory map is kept pristine.

So let's move the fake memmap code into the x86 arch tree, where it
arguably belongs.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-11-18 09:14:09 +01:00
Linus Torvalds
0e470763d8 EFI updates for v6.1
- implement EFI boot support for LoongArch
 - implement generic EFI compressed boot support for arm64, RISC-V and
   LoongArch, none of which implement a decompressor today
 - measure the kernel command line into the TPM if measured boot is in
   effect
 - refactor the EFI stub code in order to isolate DT dependencies for
   architectures other than x86
 - avoid calling SetVirtualAddressMap() on arm64 if the configured size
   of the VA space guarantees that doing so is unnecessary
 - move some ARM specific code out of the generic EFI source files
 - unmap kernel code from the x86 mixed mode 1:1 page tables
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Merge tag 'efi-next-for-v6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi

Pull EFI updates from Ard Biesheuvel:
 "A bit more going on than usual in the EFI subsystem. The main driver
  for this has been the introduction of the LoonArch architecture last
  cycle, which inspired some cleanup and refactoring of the EFI code.
  Another driver for EFI changes this cycle and in the future is
  confidential compute.

  The LoongArch architecture does not use either struct bootparams or DT
  natively [yet], and so passing information between the EFI stub and
  the core kernel using either of those is undesirable. And in general,
  overloading DT has been a source of issues on arm64, so using DT for
  this on new architectures is a to avoid for the time being (even if we
  might converge on something DT based for non-x86 architectures in the
  future). For this reason, in addition to the patch that enables EFI
  boot for LoongArch, there are a number of refactoring patches applied
  on top of which separate the DT bits from the generic EFI stub bits.
  These changes are on a separate topich branch that has been shared
  with the LoongArch maintainers, who will include it in their pull
  request as well. This is not ideal, but the best way to manage the
  conflicts without stalling LoongArch for another cycle.

  Another development inspired by LoongArch is the newly added support
  for EFI based decompressors. Instead of adding yet another
  arch-specific incarnation of this pattern for LoongArch, we are
  introducing an EFI app based on the existing EFI libstub
  infrastructure that encapulates the decompression code we use on other
  architectures, but in a way that is fully generic. This has been
  developed and tested in collaboration with distro and systemd folks,
  who are eager to start using this for systemd-boot and also for arm64
  secure boot on Fedora. Note that the EFI zimage files this introduces
  can also be decompressed by non-EFI bootloaders if needed, as the
  image header describes the location of the payload inside the image,
  and the type of compression that was used. (Note that Fedora's arm64
  GRUB is buggy [0] so you'll need a recent version or switch to
  systemd-boot in order to use this.)

  Finally, we are adding TPM measurement of the kernel command line
  provided by EFI. There is an oversight in the TCG spec which results
  in a blind spot for command line arguments passed to loaded images,
  which means that either the loader or the stub needs to take the
  measurement. Given the combinatorial explosion I am anticipating when
  it comes to firmware/bootloader stacks and firmware based attestation
  protocols (SEV-SNP, TDX, DICE, DRTM), it is good to set a baseline now
  when it comes to EFI measured boot, which is that the kernel measures
  the initrd and command line. Intermediate loaders can measure
  additional assets if needed, but with the baseline in place, we can
  deploy measured boot in a meaningful way even if you boot into Linux
  straight from the EFI firmware.

  Summary:

   - implement EFI boot support for LoongArch

   - implement generic EFI compressed boot support for arm64, RISC-V and
     LoongArch, none of which implement a decompressor today

   - measure the kernel command line into the TPM if measured boot is in
     effect

   - refactor the EFI stub code in order to isolate DT dependencies for
     architectures other than x86

   - avoid calling SetVirtualAddressMap() on arm64 if the configured
     size of the VA space guarantees that doing so is unnecessary

   - move some ARM specific code out of the generic EFI source files

   - unmap kernel code from the x86 mixed mode 1:1 page tables"

* tag 'efi-next-for-v6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi: (24 commits)
  efi/arm64: libstub: avoid SetVirtualAddressMap() when possible
  efi: zboot: create MemoryMapped() device path for the parent if needed
  efi: libstub: fix up the last remaining open coded boot service call
  efi/arm: libstub: move ARM specific code out of generic routines
  efi/libstub: measure EFI LoadOptions
  efi/libstub: refactor the initrd measuring functions
  efi/loongarch: libstub: remove dependency on flattened DT
  efi: libstub: install boot-time memory map as config table
  efi: libstub: remove DT dependency from generic stub
  efi: libstub: unify initrd loading between architectures
  efi: libstub: remove pointless goto kludge
  efi: libstub: simplify efi_get_memory_map() and struct efi_boot_memmap
  efi: libstub: avoid efi_get_memory_map() for allocating the virt map
  efi: libstub: drop pointless get_memory_map() call
  efi: libstub: fix type confusion for load_options_size
  arm64: efi: enable generic EFI compressed boot
  loongarch: efi: enable generic EFI compressed boot
  riscv: efi: enable generic EFI compressed boot
  efi/libstub: implement generic EFI zboot
  efi/libstub: move efi_system_table global var into separate object
  ...
2022-10-09 08:56:54 -07:00
Ard Biesheuvel
6c3a9c9ae0 efi/x86-mixed: move unmitigated RET into .rodata
Move the EFI mixed mode return trampoline RET into .rodata, so it is
normally mapped without executable permissions.  And given that this
snippet of code is really the only kernel code that we ever execute via
this 1:1 mapping, let's unmap the 1:1 mapping of the kernel .text, and
only map the page that covers the return trampoline with executable
permissions.

Note that the remainder of .rodata needs to remain mapped into the 1:1
mapping with RO/NX permissions, as literal GUIDs and strings may be
passed to the variable routines.

Acked-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-08-16 09:28:05 +02:00