Commit Graph

496 Commits

Author SHA1 Message Date
Sohil Mehta
8376b503b0 x86/vsyscall: Restore vsyscall=xonly mode under LASS
Background
==========
The vsyscall page is located in the high/kernel part of the address
space. Prior to LASS, a vsyscall page access from userspace would always
generate a #PF. The kernel emulates the accesses in the #PF handler and
returns the appropriate values to userspace.

Vsyscall emulation has two modes of operation, specified by the
vsyscall={xonly, emulate} kernel command line option. The vsyscall page
behaves as execute-only in XONLY mode or read-execute in EMULATE mode.
XONLY mode is the default and the only one expected to be commonly used.
The EMULATE mode has been deprecated since 2022 and is considered
insecure.

With LASS, a vsyscall page access triggers a #GP instead of a #PF.
Currently, LASS is only enabled when all vsyscall modes are disabled.

LASS with XONLY mode
====================
Now add support for LASS specifically with XONLY vsyscall emulation. For
XONLY mode, all that is needed is the faulting RIP, which is trivially
available regardless of the type of fault. Reuse the #PF emulation code
during the #GP when the fault address points to the vsyscall page.

As multiple fault handlers will now be using the emulation code, add a
sanity check to ensure that the fault truly happened in 64-bit user
mode.

LASS with EMULATE mode
======================
Supporting vsyscall=emulate with LASS is much harder because the #GP
doesn't provide enough error information (such as PFEC and CR2 as in
case of a #PF). So, complex instruction decoding would be required to
emulate this mode in the #GP handler.

This isn't worth the effort as remaining users of EMULATE mode can be
reasonably assumed to be niche users, who are already trading off
security for compatibility. LASS and vsyscall=emulate will be kept
mutually exclusive for simplicity.

Signed-off-by: Sohil Mehta <sohil.mehta@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: H. Peter Anvin (Intel) <hpa@zytor.com>
Tested-by: Maciej Wieczor-Retman <maciej.wieczor-retman@intel.com>
Link: https://patch.msgid.link/20260309181029.398498-4-sohil.mehta@intel.com
2026-03-19 15:11:13 -07:00
Sohil Mehta
4e57fdd110 x86/traps: Consolidate user fixups in the #GP handler
Move the UMIP exception fixup under the common "if (user_mode(regs))"
condition where the rest of user mode fixups reside. Also, move the UMIP
feature check into its fixup function to keep the calling code
consistent and clean.

No functional change intended.

Suggested-by: Dave Hansen <dave.hansen@intel.com>
Signed-off-by: Sohil Mehta <sohil.mehta@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: H. Peter Anvin (Intel) <hpa@zytor.com>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Tested-by: Maciej Wieczor-Retman <maciej.wieczor-retman@intel.com>
Link: https://patch.msgid.link/20260309181029.398498-3-sohil.mehta@intel.com
2026-03-19 15:11:13 -07:00
Hou Wenlong
a0cb371b52 x86/bug: Handle __WARN_printf() trap in early_fixup_exception()
The commit 5b472b6e5b ("x86_64/bug: Implement __WARN_printf()")
implemented __WARN_printf(), which changed the mechanism to use UD1
instead of UD2. However, it only handles the trap in the runtime IDT
handler, while the early booting IDT handler lacks this handling. As a
result, the usage of WARN() before the runtime IDT setup can lead to
kernel crashes. Since KMSAN is enabled after the runtime IDT setup, it
is safe to use handle_bug() directly in early_fixup_exception() to
address this issue.

Fixes: 5b472b6e5b ("x86_64/bug: Implement __WARN_printf()")
Signed-off-by: Hou Wenlong <houwenlong.hwl@antgroup.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/c4fb3645f60d3a78629d9870e8fcc8535281c24f.1768016713.git.houwenlong.hwl@antgroup.com
2026-02-23 11:19:11 +01:00
Ryosuke Yasuoka
6b32c93560 x86/traps: Print unhashed pointers on stack overflow
When a stack overflow occurs, the kernel prints hashed fault address and the
stack range using %p. The actual addresses are required for debugging and
hashed pointers provide no useful information in this context.

Use %px to print the unhashed, raw addresses.

Signed-off-by: Ryosuke Yasuoka <ryasuoka@redhat.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://patch.msgid.link/20251224070735.454816-1-ryasuoka@redhat.com
2026-01-14 16:31:53 +01:00
Linus Torvalds
d61f1cc5db * Enable Linear Address Space Separation (LASS)
* Change X86_FEATURE leaf 17 from an AMD leaf to Linux-defined
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEEV76QKkVc4xCGURexaDWVMHDJkrAFAmkuIXAACgkQaDWVMHDJ
 krAwoRAAqqavNrthj26XJHjR3x7FVGu11/rvYXAd1U2moN/dhM2w82HMHNFvPuQY
 3iq9GDRQdc2rKL7LTkREvN4ZM/rFvkFLt6a5Yv0eCRK8KAiSJEw6Yzu/qgG7kF+0
 9clujDUskjjHU0zR5v+o1RxirrLVQ+R50sMVI5uoFx6+WJRiW1BvMG4Csw4BgbvA
 AqgrZpyq1dQ/GQOW4f0yxBPH0z84wgUbdllYzQzE0GeUlGWQSI4lqa8GFMOmE/Gr
 7gBcKmyE0M/BycwTZW7tiMnjWgNL+Y5/RroQJ7hh6R+f5WOd+SpGvlyOihbF7GER
 L3yZfeQ+EWz1aY1QMWwOSvSawIPJo8EkSn3d9/JFq5Vl9zsFh+ZoPZfZ8bEi36U0
 inO93swDcyMkkfOTh4sIgxedLgHja5GFNCGPs0yblvLulWbw7yYVzzEmEjXnclzS
 fmmifsJjGrUpegEnWdEjAQzXkWPd/hKiAvpzDE/3thBal5NkOzFrudITFvCVuk8w
 uS2MW0U8VCskNoON0jjwnvv84p0XdHJOsgPB9WnsuMMASKC1RqKAJWXh8AXvZA+I
 TfCNdSyHDTm+o1e+SMQZRbqoE/r7MmAxUQOkKnlvpJDCz58tsLzW64hRXTe7QpCt
 rry9/wODswu+oaHoDgfjAmzYde2RhCjwWLzGmqmapNIYfCCVhYs=
 =5bcW
 -----END PGP SIGNATURE-----

Merge tag 'x86_cpu_for_6.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 CPU feature updates from Dave Hansen:
 "The biggest thing of note here is Linear Address Space Separation
  (LASS). It represents the first time I can think of that the
  upper=>kernel/lower=>user address space convention is actually
  recognized by the hardware on x86. It ensures that userspace can not
  even get the hardware to _start_ page walks for the kernel address
  space. This, of course, is a really nice generic side channel defense.

  This is really only a down payment on LASS support. There are still
  some details to work out in its interaction with EFI calls and
  vsyscall emulation. For now, LASS is disabled if either of those
  features is compiled in (which is almost always the case).

  There's also one straggler commit in here which converts an
  under-utilized AMD CPU feature leaf into a generic Linux-defined leaf
  so more feature can be packed in there.

  Summary:

   - Enable Linear Address Space Separation (LASS)

   - Change X86_FEATURE leaf 17 from an AMD leaf to Linux-defined"

* tag 'x86_cpu_for_6.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/cpu: Enable LASS during CPU initialization
  selftests/x86: Update the negative vsyscall tests to expect a #GP
  x86/traps: Communicate a LASS violation in #GP message
  x86/kexec: Disable LASS during relocate kernel
  x86/alternatives: Disable LASS when patching kernel code
  x86/asm: Introduce inline memcpy and memset
  x86/cpu: Add an LASS dependency on SMAP
  x86/cpufeatures: Enumerate the LASS feature bits
  x86/cpufeatures: Make X86_FEATURE leaf 17 Linux-specific
2025-12-02 14:48:08 -08:00
Peter Zijlstra
860238af7a x86_64/bug: Inline the UD1
(Ab)use the static_call infrastructure to convert all:

  call __WARN_trap

instances into the desired:

  ud1 (%edx), %rdi

eliminating the CALL/RET, but more importantly, fixing the
fact that all WARNs will have:

  RIP: 0010:__WARN_trap+0

Basically, by making it a static_call trampoline call, objtool will
collect the callsites, and then the inline rewrite will hit the
special case and replace the code with the magic instruction.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20251110115758.456717741@infradead.org
2025-11-24 20:23:25 +01:00
Peter Zijlstra
5b472b6e5b x86_64/bug: Implement __WARN_printf()
The basic idea is to have __WARN_printf() be a vararg function such
that the compiler can do the optimal calling convention for us. This
function body will be a #UD and then set up a va_list in the exception
from pt_regs.

But because the trap will be in a called function, the bug_entry must
be passed in. Have that be the first argument, with the format tucked
away inside the bug_entry.

The comments should clarify the real fun details.

The big downside is that all WARNs will now show:

 RIP: 0010:__WARN_trap:+0

One possible solution is to simply discard the top frame when
unwinding. A follow up patch takes care of this slightly differently
by abusing the x86 static_call implementation.

This changes (with the next patches):

	WARN_ONCE(preempt_count() != 2*PREEMPT_DISABLE_OFFSET,
		  "corrupted preempt_count: %s/%d/0x%x\n",

from:

	cmpl    $2, %ecx	#, _7
        jne     .L1472
	...

  .L1472:
        cmpb    $0, __already_done.11(%rip)
        je      .L1513
	...

  .L1513
	movb    $1, __already_done.11(%rip)
	movl    1424(%r14), %edx        # _15->pid, _15->pid
        leaq    1912(%r14), %rsi        #, _17
        movq    $.LC43, %rdi    #,
        call    __warn_printk   #
	ud2
  .pushsection __bug_table,"aw"
        2:
        .long 1b - .    # bug_entry::bug_addr
        .long .LC1 - .  # bug_entry::file
        .word 5093      # bug_entry::line
        .word 2313      # bug_entry::flags
        .org 2b + 12
  .popsection
  .pushsection .discard.annotate_insn,"M", @progbits, 8
        .long 1b - .
        .long 8         # ANNOTYPE_REACHABLE
  .popsection

into:

	cmpl    $2, %ecx        #, _7
        jne     .L1442  #,
	...

  .L1442:
        lea (2f)(%rip), %rdi
  1:
  .pushsection __bug_table,"aw"
        2:
        .long 1b - .    # bug_entry::bug_addr
        .long .LC43 - . # bug_entry::format
        .long .LC1 - .  # bug_entry::file
        .word 5093      # bug_entry::line
        .word 2323      # bug_entry::flags
        .org 2b + 16
  .popsection
        movl    1424(%r14), %edx        # _19->pid, _19->pid
        leaq    1912(%r14), %rsi        #, _13
	ud1 (%edx), %rdi

Notably, by pushing everything into the exception handler it can take
care of the ONCE thing.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20251110115758.213813530@infradead.org
2025-11-24 20:23:05 +01:00
Alexander Shishkin
42fea0a3a7 x86/traps: Communicate a LASS violation in #GP message
A LASS violation typically results in a #GP. With LASS active, any
invalid access to user memory (including the first page frame) would be
reported as a #GP, instead of a #PF.

Unfortunately, the #GP error messages provide limited information about
the cause of the fault. This could be confusing for kernel developers
and users who are accustomed to the friendly #PF messages.

To make the transition easier, enhance the #GP Oops message to include a
hint about LASS violations. Also, add a special hint for kernel NULL
pointer dereferences to match with the existing #PF message.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Sohil Mehta <sohil.mehta@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://patch.msgid.link/20251118182911.2983253-7-sohil.mehta%40intel.com
2025-11-18 10:38:26 -08:00
Peter Zijlstra
85a2d4a890 x86,ibt: Use UDB instead of 0xEA
A while ago [0] FineIBT started using the 0xEA instruction to raise #UD.
All existing parts will generate #UD in 64bit mode on that instruction.

However; Intel/AMD have not blessed using this instruction, it is on
their 'reserved' opcode list for future use.

Peter Anvin worked the committees and got use of 0xD6 blessed, it
shall be called UDB (per the next SDM or so), and it being a single
byte instruction is easy to slip into a single byte immediate -- as
is done by this very patch.

Reworking the FineIBT code to use UDB wasn't entirely trivial. Notably
the FineIBT-BHI1 case ran out of bytes. In order to condense the
encoding some it was required to move the hash register from R10D to
EAX (thanks hpa!).

Per the x86_64 ABI, RAX is used to pass the number of vector registers
for vararg function calls -- something that should not happen in the
kernel. More so, the kernel is built with -mskip-rax-setup, which
should leave RAX completely unused, allowing its re-use.

 [ For BPF; while the bpf2bpf tail-call uses RAX in its calling
   convention, that does not use CFI and is unaffected. Only the
   'regular' C->BPF transition is covered by CFI. ]

The ENDBR poison value is changed from 'OSP NOP3' to 'NOPL -42(%RAX)',
this is basically NOP4 but with UDB as its immediate. As such it is
still a non-standard NOP value unique to prior ENDBR sites, but now
also provides UDB.

Per Agner Fog's optimization guide, Jcc is assumed not-taken. That is,
the expected path should be the fallthrough case for improved
throughput.

Since the preamble now relies on the ENDBR poison to provide UDB, the
code is changed to write the poison right along with the initial
preamble -- this is possible because the ITS mitigation already
disabled IBT over rewriting the CFI scheme.

The scheme in detail:

Preamble:

  FineIBT			FineIBT-BHI1			FineIBT-BHI

  __cfi_\func:			__cfi_\func:			__cfi_\func:
    endbr			  endbr				  endbr
    subl       $0x12345678, %eax  subl      $0x12345678, %eax	  subl       $0x12345678, %eax
    jne.d32,np \func+3		  cmovne    %rax, %rdi		  cs cs call __bhi_args_N
                                  jne.d8,np \func+3
  \func:			\func:				\func:
    nopl       -42(%rax)	  nopl      -42(%rax)		  nopl       -42(%rax)

Notably there are 7 bytes available after the SUBL; this enables the
BHI1 case to fit without the nasty overlapping case it had previously.
The !BHI case uses Jcc.d32,np to consume all 7 bytes without the need
for an additional NOP, while the BHI case uses CS padding to align the
CALL with the end of the preamble such that it returns to \func+0.

Caller:

  FineIBT				Paranoid-FineIBT

  fineibt_caller:			fineibt_caller:
    mov     $0x12345678, %eax		  mov    $0x12345678, %eax
    lea     -10(%r11), %r11		  cmp    -0x11(%r11), %eax
    nop5				  cs lea -0x10(%r11), %r11
  retpoline:				retpoline:
    cs call __x86_indirect_thunk_r11	  jne    fineibt_caller+0xd
					  call   *%r11
					  nop

Notably this is before apply_retpolines() which will fix up the
retpoline call -- since all parts with IBT also have eIBRS (lets
ignore ITS). Typically the retpoline site is rewritten (when still
intact) into:

    call *%r11
    nop3

[0] 06926c6cdb ("x86/ibt: Optimize the FineIBT instruction sequence")

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20250901191307.GI4067720@noisy.programming.kicks-ass.net
2025-09-04 21:59:09 +02:00
Xin Li (Intel)
5f465c148c x86/traps: Initialize DR6 by writing its architectural reset value
Initialize DR6 by writing its architectural reset value to avoid
incorrectly zeroing DR6 to clear DR6.BLD at boot time, which leads
to a false bus lock detected warning.

The Intel SDM says:

  1) Certain debug exceptions may clear bits 0-3 of DR6.

  2) BLD induced #DB clears DR6.BLD and any other debug exception
     doesn't modify DR6.BLD.

  3) RTM induced #DB clears DR6.RTM and any other debug exception
     sets DR6.RTM.

  To avoid confusion in identifying debug exceptions, debug handlers
  should set DR6.BLD and DR6.RTM, and clear other DR6 bits before
  returning.

The DR6 architectural reset value 0xFFFF0FF0, already defined as
macro DR6_RESERVED, satisfies these requirements, so just use it to
reinitialize DR6 whenever needed.

Since clear_all_debug_regs() no longer zeros all debug registers,
rename it to initialize_debug_regs() to better reflect its current
behavior.

Since debug_read_clear_dr6() no longer clears DR6, rename it to
debug_read_reset_dr6() to better reflect its current behavior.

Fixes: ebb1064e7c ("x86/traps: Handle #DB for bus lock")
Reported-by: Sohil Mehta <sohil.mehta@intel.com>
Suggested-by: H. Peter Anvin (Intel) <hpa@zytor.com>
Signed-off-by: Xin Li (Intel) <xin@zytor.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: H. Peter Anvin (Intel) <hpa@zytor.com>
Reviewed-by: Sohil Mehta <sohil.mehta@intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Sohil Mehta <sohil.mehta@intel.com>
Link: https://lore.kernel.org/lkml/06e68373-a92b-472e-8fd9-ba548119770c@intel.com/
Cc:stable@vger.kernel.org
Link: https://lore.kernel.org/all/20250620231504.2676902-2-xin%40zytor.com
2025-06-24 13:15:51 -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").
 -----BEGIN PGP SIGNATURE-----
 
 iQFIBAABCAAyFiEE8TM4V0tmI4mGbHaCv/vSX3jHroMFAmg02hwUHHBib256aW5p
 QHJlZGhhdC5jb20ACgkQv/vSX3jHroNnkwf/db4xeWKSMseCIvBVR+ObDn3LXhwT
 hAgmTkDkP1zq9RfbfJSbUA1DXRwfP+f1sWySLMWECkFEQW9fGIJF9fOQRDSXKmhX
 158U3+FEt+3jxLRCGFd4zyXAqyY3C8JSkPUyJZxCpUbXtB5tdDNac4rZAXKDULwe
 sUi0OW/kFDM2yt369pBGQAGdN+75/oOrYISGOSvMXHxjccNqvveX8MUhpBjYIuuj
 73iBWmsfv3vCtam56Racz3C3v44ie498PmWFtnB0R+CVfWfrnUAaRiGWx+egLiBW
 dBPDiZywMn++prmphEUFgaStDTQy23JBLJ8+RvHkp+o5GaTISKJB3nedZQ==
 =adZU
 -----END PGP SIGNATURE-----

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
Ingo Molnar
1f82e8e1ca Merge branch 'x86/msr' into x86/core, to resolve conflicts
Conflicts:
	arch/x86/boot/startup/sme.c
	arch/x86/coco/sev/core.c
	arch/x86/kernel/fpu/core.c
	arch/x86/kernel/fpu/xstate.c

 Semantic conflict:
	arch/x86/include/asm/sev-internal.h

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2025-05-13 10:42:06 +02:00
Ingo Molnar
ec8f353f52 Merge branch 'x86/fpu' 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 10:37:29 +02:00
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
Xin Li (Intel)
efef7f184f x86/msr: Add explicit includes of <asm/msr.h>
For historic reasons there are some TSC-related functions in the
<asm/msr.h> header, even though there's an <asm/tsc.h> header.

To facilitate the relocation of rdtsc{,_ordered}() from <asm/msr.h>
to <asm/tsc.h> and to eventually eliminate the inclusion of
<asm/msr.h> in <asm/tsc.h>, add an explicit <asm/msr.h> dependency
to the source files that reference definitions from <asm/msr.h>.

[ mingo: Clarified the changelog. ]

Signed-off-by: Xin Li (Intel) <xin@zytor.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Uros Bizjak <ubizjak@gmail.com>
Link: https://lore.kernel.org/r/20250501054241.1245648-1-xin@zytor.com
2025-05-02 10:23:47 +02:00
Ingo Molnar
e3bfa38599 x86/fpu: Convert task_struct::thread.fpu accesses to use x86_task_fpu()
This will make the removal of the task_struct::thread.fpu array
easier.

No change in functionality - code generated before and after this
commit is identical on x86-defconfig:

  kepler:~/tip> diff -up vmlinux.before.asm vmlinux.after.asm
  kepler:~/tip>

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Chang S. Bae <chang.seok.bae@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Link: https://lore.kernel.org/r/20250409211127.3544993-3-mingo@kernel.org
2025-04-14 08:18:29 +02:00
Ingo Molnar
5236b6a0fe x86/alternatives: Rename 'poke_int3_handler()' to 'smp_text_poke_int3_handler()'
All related functions in this subsystem already have a
text_poke_int3_ prefix - add it to the trap handler
as well.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Juergen Gross <jgross@suse.com>
Cc: "H . Peter Anvin" <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20250411054105.2341982-8-mingo@kernel.org
2025-04-11 11:01:33 +02:00
Ingo Molnar
78255eb239 x86/msr: Rename 'wrmsrl()' to 'wrmsrq()'
Suggested-by: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Juergen Gross <jgross@suse.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Xin Li <xin@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
2025-04-10 11:58:33 +02:00
Ingo Molnar
c435e608cf x86/msr: Rename 'rdmsrl()' to 'rdmsrq()'
Suggested-by: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Juergen Gross <jgross@suse.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Xin Li <xin@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
2025-04-10 11:58:27 +02:00
Linus Torvalds
e34c38057a [ Merge note: this pull request depends on you having merged
two locking commits in the locking tree,
 	      part of the locking-core-2025-03-22 pull request. ]
 
 x86 CPU features support:
   - Generate the <asm/cpufeaturemasks.h> header based on build config
     (H. Peter Anvin, Xin Li)
   - x86 CPUID parsing updates and fixes (Ahmed S. Darwish)
   - Introduce the 'setcpuid=' boot parameter (Brendan Jackman)
   - Enable modifying CPU bug flags with '{clear,set}puid='
     (Brendan Jackman)
   - Utilize CPU-type for CPU matching (Pawan Gupta)
   - Warn about unmet CPU feature dependencies (Sohil Mehta)
   - Prepare for new Intel Family numbers (Sohil Mehta)
 
 Percpu code:
   - Standardize & reorganize the x86 percpu layout and
     related cleanups (Brian Gerst)
   - Convert the stackprotector canary to a regular percpu
     variable (Brian Gerst)
   - Add a percpu subsection for cache hot data (Brian Gerst)
   - Unify __pcpu_op{1,2}_N() macros to __pcpu_op_N() (Uros Bizjak)
   - Construct __percpu_seg_override from __percpu_seg (Uros Bizjak)
 
 MM:
   - Add support for broadcast TLB invalidation using AMD's INVLPGB instruction
     (Rik van Riel)
   - Rework ROX cache to avoid writable copy (Mike Rapoport)
   - PAT: restore large ROX pages after fragmentation
     (Kirill A. Shutemov, Mike Rapoport)
   - Make memremap(MEMREMAP_WB) map memory as encrypted by default
     (Kirill A. Shutemov)
   - Robustify page table initialization (Kirill A. Shutemov)
   - Fix flush_tlb_range() when used for zapping normal PMDs (Jann Horn)
   - Clear _PAGE_DIRTY for kernel mappings when we clear _PAGE_RW
     (Matthew Wilcox)
 
 KASLR:
   - x86/kaslr: Reduce KASLR entropy on most x86 systems,
     to support PCI BAR space beyond the 10TiB region
     (CONFIG_PCI_P2PDMA=y) (Balbir Singh)
 
 CPU bugs:
   - Implement FineIBT-BHI mitigation (Peter Zijlstra)
   - speculation: Simplify and make CALL_NOSPEC consistent (Pawan Gupta)
   - speculation: Add a conditional CS prefix to CALL_NOSPEC (Pawan Gupta)
   - RFDS: Exclude P-only parts from the RFDS affected list (Pawan Gupta)
 
 System calls:
   - Break up entry/common.c (Brian Gerst)
   - Move sysctls into arch/x86 (Joel Granados)
 
 Intel LAM support updates: (Maciej Wieczor-Retman)
   - selftests/lam: Move cpu_has_la57() to use cpuinfo flag
   - selftests/lam: Skip test if LAM is disabled
   - selftests/lam: Test get_user() LAM pointer handling
 
 AMD SMN access updates:
   - Add SMN offsets to exclusive region access (Mario Limonciello)
   - Add support for debugfs access to SMN registers (Mario Limonciello)
   - Have HSMP use SMN through AMD_NODE (Yazen Ghannam)
 
 Power management updates: (Patryk Wlazlyn)
   - Allow calling mwait_play_dead with an arbitrary hint
   - ACPI/processor_idle: Add FFH state handling
   - intel_idle: Provide the default enter_dead() handler
   - Eliminate mwait_play_dead_cpuid_hint()
 
 Bootup:
 
 Build system:
   - Raise the minimum GCC version to 8.1 (Brian Gerst)
   - Raise the minimum LLVM version to 15.0.0
     (Nathan Chancellor)
 
 Kconfig: (Arnd Bergmann)
   - Add cmpxchg8b support back to Geode CPUs
   - Drop 32-bit "bigsmp" machine support
   - Rework CONFIG_GENERIC_CPU compiler flags
   - Drop configuration options for early 64-bit CPUs
   - Remove CONFIG_HIGHMEM64G support
   - Drop CONFIG_SWIOTLB for PAE
   - Drop support for CONFIG_HIGHPTE
   - Document CONFIG_X86_INTEL_MID as 64-bit-only
   - Remove old STA2x11 support
   - Only allow CONFIG_EISA for 32-bit
 
 Headers:
   - Replace __ASSEMBLY__ with __ASSEMBLER__ in UAPI and non-UAPI headers
     (Thomas Huth)
 
 Assembly code & machine code patching:
   - x86/alternatives: Simplify alternative_call() interface (Josh Poimboeuf)
   - x86/alternatives: Simplify callthunk patching (Peter Zijlstra)
   - KVM: VMX: Use named operands in inline asm (Josh Poimboeuf)
   - x86/hyperv: Use named operands in inline asm (Josh Poimboeuf)
   - x86/traps: Cleanup and robustify decode_bug() (Peter Zijlstra)
   - x86/kexec: Merge x86_32 and x86_64 code using macros from <asm/asm.h>
     (Uros Bizjak)
   - Use named operands in inline asm (Uros Bizjak)
   - Improve performance by using asm_inline() for atomic locking instructions
     (Uros Bizjak)
 
 Earlyprintk:
   - Harden early_serial (Peter Zijlstra)
 
 NMI handler:
   - Add an emergency handler in nmi_desc & use it in nmi_shootdown_cpus()
     (Waiman Long)
 
 Miscellaneous fixes and cleanups:
 
   - by Ahmed S. Darwish, Andy Shevchenko, Ard Biesheuvel,
     Artem Bityutskiy, Borislav Petkov, Brendan Jackman, Brian Gerst,
     Dan Carpenter, Dr. David Alan Gilbert, H. Peter Anvin,
     Ingo Molnar, Josh Poimboeuf, Kevin Brodsky, Mike Rapoport,
     Lukas Bulwahn, Maciej Wieczor-Retman, Max Grobecker,
     Patryk Wlazlyn, Pawan Gupta, Peter Zijlstra,
     Philip Redkin, Qasim Ijaz, Rik van Riel, Thomas Gleixner,
     Thorsten Blum, Tom Lendacky, Tony Luck, Uros Bizjak,
     Vitaly Kuznetsov, Xin Li, liuye.
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
 -----BEGIN PGP SIGNATURE-----
 
 iQJFBAABCgAvFiEEBpT5eoXrXCwVQwEKEnMQ0APhK1gFAmfenkQRHG1pbmdvQGtl
 cm5lbC5vcmcACgkQEnMQ0APhK1g1FRAAi6OFTSn/5aeLMI0IMNBxJ6ddQiFc3imd
 7+C/vU5nul4CyDs8mKyj/+f/DDrbkG9lKz3VG631Yl237lXHjD8XWcVMeC/1z/q0
 3zInDIloE9/nBHRPkF6F7fARBLBZ0LFgaBsGrCo7mwpGybiQdqGcqcxllvTbtXaw
 OHta4q6ok+lBDNlfc0v6H4cRnzhmmlKu6Ng0j6UI3V7uFhi3vtxas32ltDQtzorq
 2+jbV6/+kbrrv+xPC+jlzOFhTEKRupNPQXmvyQteoQg6G3kqAKMDvBthGXd1rHuX
 Qa+BoDIifE/2NiVeRwNrhoqYH/pHCzUzDREW5IW8+ca+4XNKuzAC6EuC8CeCzyK1
 q8ZjZjooQW4zEeVFeJYllHONzJYfxfSH5CLsnbcuhq99yfGlrQhF1qL72/Omn1w/
 DfPJM8Zt5zyKvLqUg3Md+fkVCO2wyDNhB61QPzRgHF+yD+rvuDpoqvUWir+w7cSn
 fwEDVZGXlFx6dumtSrqRaTd1nvFt80s8yP2ll09DMvGQ8D/yruS7hndGAmmJVCSW
 NAfd8pSjq5v2+ux2UR92/Cc3VF3SjaUqHBOp/Nq9rESya18ZVa3cJpHhVYYtPIVf
 THW0h07RIkGVKs1uq+5ekLCr/8uAZg58UPIqmhTuW0ttymRHCNfohR45FQZzy+0M
 tJj1oc2TIZw=
 =Dcb3
 -----END PGP SIGNATURE-----

Merge tag 'x86-core-2025-03-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull core x86 updates from Ingo Molnar:
 "x86 CPU features support:
   - Generate the <asm/cpufeaturemasks.h> header based on build config
     (H. Peter Anvin, Xin Li)
   - x86 CPUID parsing updates and fixes (Ahmed S. Darwish)
   - Introduce the 'setcpuid=' boot parameter (Brendan Jackman)
   - Enable modifying CPU bug flags with '{clear,set}puid=' (Brendan
     Jackman)
   - Utilize CPU-type for CPU matching (Pawan Gupta)
   - Warn about unmet CPU feature dependencies (Sohil Mehta)
   - Prepare for new Intel Family numbers (Sohil Mehta)

  Percpu code:
   - Standardize & reorganize the x86 percpu layout and related cleanups
     (Brian Gerst)
   - Convert the stackprotector canary to a regular percpu variable
     (Brian Gerst)
   - Add a percpu subsection for cache hot data (Brian Gerst)
   - Unify __pcpu_op{1,2}_N() macros to __pcpu_op_N() (Uros Bizjak)
   - Construct __percpu_seg_override from __percpu_seg (Uros Bizjak)

  MM:
   - Add support for broadcast TLB invalidation using AMD's INVLPGB
     instruction (Rik van Riel)
   - Rework ROX cache to avoid writable copy (Mike Rapoport)
   - PAT: restore large ROX pages after fragmentation (Kirill A.
     Shutemov, Mike Rapoport)
   - Make memremap(MEMREMAP_WB) map memory as encrypted by default
     (Kirill A. Shutemov)
   - Robustify page table initialization (Kirill A. Shutemov)
   - Fix flush_tlb_range() when used for zapping normal PMDs (Jann Horn)
   - Clear _PAGE_DIRTY for kernel mappings when we clear _PAGE_RW
     (Matthew Wilcox)

  KASLR:
   - x86/kaslr: Reduce KASLR entropy on most x86 systems, to support PCI
     BAR space beyond the 10TiB region (CONFIG_PCI_P2PDMA=y) (Balbir
     Singh)

  CPU bugs:
   - Implement FineIBT-BHI mitigation (Peter Zijlstra)
   - speculation: Simplify and make CALL_NOSPEC consistent (Pawan Gupta)
   - speculation: Add a conditional CS prefix to CALL_NOSPEC (Pawan
     Gupta)
   - RFDS: Exclude P-only parts from the RFDS affected list (Pawan
     Gupta)

  System calls:
   - Break up entry/common.c (Brian Gerst)
   - Move sysctls into arch/x86 (Joel Granados)

  Intel LAM support updates: (Maciej Wieczor-Retman)
   - selftests/lam: Move cpu_has_la57() to use cpuinfo flag
   - selftests/lam: Skip test if LAM is disabled
   - selftests/lam: Test get_user() LAM pointer handling

  AMD SMN access updates:
   - Add SMN offsets to exclusive region access (Mario Limonciello)
   - Add support for debugfs access to SMN registers (Mario Limonciello)
   - Have HSMP use SMN through AMD_NODE (Yazen Ghannam)

  Power management updates: (Patryk Wlazlyn)
   - Allow calling mwait_play_dead with an arbitrary hint
   - ACPI/processor_idle: Add FFH state handling
   - intel_idle: Provide the default enter_dead() handler
   - Eliminate mwait_play_dead_cpuid_hint()

  Build system:
   - Raise the minimum GCC version to 8.1 (Brian Gerst)
   - Raise the minimum LLVM version to 15.0.0 (Nathan Chancellor)

  Kconfig: (Arnd Bergmann)
   - Add cmpxchg8b support back to Geode CPUs
   - Drop 32-bit "bigsmp" machine support
   - Rework CONFIG_GENERIC_CPU compiler flags
   - Drop configuration options for early 64-bit CPUs
   - Remove CONFIG_HIGHMEM64G support
   - Drop CONFIG_SWIOTLB for PAE
   - Drop support for CONFIG_HIGHPTE
   - Document CONFIG_X86_INTEL_MID as 64-bit-only
   - Remove old STA2x11 support
   - Only allow CONFIG_EISA for 32-bit

  Headers:
   - Replace __ASSEMBLY__ with __ASSEMBLER__ in UAPI and non-UAPI
     headers (Thomas Huth)

  Assembly code & machine code patching:
   - x86/alternatives: Simplify alternative_call() interface (Josh
     Poimboeuf)
   - x86/alternatives: Simplify callthunk patching (Peter Zijlstra)
   - KVM: VMX: Use named operands in inline asm (Josh Poimboeuf)
   - x86/hyperv: Use named operands in inline asm (Josh Poimboeuf)
   - x86/traps: Cleanup and robustify decode_bug() (Peter Zijlstra)
   - x86/kexec: Merge x86_32 and x86_64 code using macros from
     <asm/asm.h> (Uros Bizjak)
   - Use named operands in inline asm (Uros Bizjak)
   - Improve performance by using asm_inline() for atomic locking
     instructions (Uros Bizjak)

  Earlyprintk:
   - Harden early_serial (Peter Zijlstra)

  NMI handler:
   - Add an emergency handler in nmi_desc & use it in
     nmi_shootdown_cpus() (Waiman Long)

  Miscellaneous fixes and cleanups:
   - by Ahmed S. Darwish, Andy Shevchenko, Ard Biesheuvel, Artem
     Bityutskiy, Borislav Petkov, Brendan Jackman, Brian Gerst, Dan
     Carpenter, Dr. David Alan Gilbert, H. Peter Anvin, Ingo Molnar,
     Josh Poimboeuf, Kevin Brodsky, Mike Rapoport, Lukas Bulwahn, Maciej
     Wieczor-Retman, Max Grobecker, Patryk Wlazlyn, Pawan Gupta, Peter
     Zijlstra, Philip Redkin, Qasim Ijaz, Rik van Riel, Thomas Gleixner,
     Thorsten Blum, Tom Lendacky, Tony Luck, Uros Bizjak, Vitaly
     Kuznetsov, Xin Li, liuye"

* tag 'x86-core-2025-03-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (211 commits)
  zstd: Increase DYNAMIC_BMI2 GCC version cutoff from 4.8 to 11.0 to work around compiler segfault
  x86/asm: Make asm export of __ref_stack_chk_guard unconditional
  x86/mm: Only do broadcast flush from reclaim if pages were unmapped
  perf/x86/intel, x86/cpu: Replace Pentium 4 model checks with VFM ones
  perf/x86/intel, x86/cpu: Simplify Intel PMU initialization
  x86/headers: Replace __ASSEMBLY__ with __ASSEMBLER__ in non-UAPI headers
  x86/headers: Replace __ASSEMBLY__ with __ASSEMBLER__ in UAPI headers
  x86/locking/atomic: Improve performance by using asm_inline() for atomic locking instructions
  x86/asm: Use asm_inline() instead of asm() in clwb()
  x86/asm: Use CLFLUSHOPT and CLWB mnemonics in <asm/special_insns.h>
  x86/hweight: Use asm_inline() instead of asm()
  x86/hweight: Use ASM_CALL_CONSTRAINT in inline asm()
  x86/hweight: Use named operands in inline asm()
  x86/stackprotector/64: Only export __ref_stack_chk_guard on CONFIG_SMP
  x86/head/64: Avoid Clang < 17 stack protector in startup code
  x86/kexec: Merge x86_32 and x86_64 code using macros from <asm/asm.h>
  x86/runtime-const: Add the RUNTIME_CONST_PTR assembly macro
  x86/cpu/intel: Limit the non-architectural constant_tsc model checks
  x86/mm/pat: Replace Intel x86_model checks with VFM ones
  x86/cpu/intel: Fix fast string initialization for extended Families
  ...
2025-03-24 22:06:11 -07:00
Josh Poimboeuf
8085fcd78c x86/traps: Make exc_double_fault() consistently noreturn
The CONFIG_X86_ESPFIX64 version of exc_double_fault() can return to its
caller, but the !CONFIG_X86_ESPFIX64 version never does.  In the latter
case the compiler and/or objtool may consider it to be implicitly
noreturn.

However, due to the currently inflexible way objtool detects noreturns,
a function's noreturn status needs to be consistent across configs.

The current workaround for this issue is to suppress unreachable
warnings for exc_double_fault()'s callers.  Unfortunately that can
result in ORC coverage gaps and potentially worse issues like inert
static calls and silently disabled CPU mitigations.

Instead, prevent exc_double_fault() from ever being implicitly marked
noreturn by forcing a return behind a never-taken conditional.

Until a more integrated noreturn detection method exists, this is likely
the least objectionable workaround.

Fixes: 55eeab2a8a ("objtool: Ignore exc_double_fault() __noreturn warnings")
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Brendan Jackman <jackmanb@google.com>
Link: https://lore.kernel.org/r/d1f4026f8dc35d0de6cc61f2684e0cb6484009d1.1741975349.git.jpoimboe@kernel.org
2025-03-17 11:35:59 +01:00
Peter Zijlstra
029f718fed x86/traps: Decode LOCK Jcc.d8 as #UD
Because overlapping code sequences are all the rage.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Kees Cook <kees@kernel.org>
Link: https://lore.kernel.org/r/20250224124200.486463917@infradead.org
2025-02-26 12:24:17 +01:00
Peter Zijlstra
e33d805a10 x86/traps: Allow custom fixups in handle_bug()
The normal fixup in handle_bug() is simply continuing at the next
instruction. However upcoming patches make this the wrong thing, so
allow handlers (specifically handle_cfi_failure()) to over-ride
regs->ip.

The callchain is such that the fixup needs to be done before it is
determined if the exception is fatal, as such, revert any changes in
that case.

Additionally, have handle_cfi_failure() remember the regs->ip value it
starts with for reporting.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Kees Cook <kees@kernel.org>
Link: https://lore.kernel.org/r/20250224124200.275223080@infradead.org
2025-02-26 12:22:39 +01:00
Peter Zijlstra
2e044911be x86/traps: Decode 0xEA instructions as #UD
FineIBT will start using 0xEA as #UD. Normally '0xEA' is a 'bad',
invalid instruction for the CPU.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Kees Cook <kees@kernel.org>
Link: https://lore.kernel.org/r/20250224124200.166774696@infradead.org
2025-02-26 12:22:10 +01:00
Peter Zijlstra
c20ad96c9a x86/traps: Cleanup and robustify decode_bug()
Notably, don't attempt to decode an immediate when MOD == 3.

Additionally have it return the instruction length, such that WARN
like bugs can more reliably skip to the correct instruction.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Link: https://lore.kernel.org/r/20250207122546.721120726@infradead.org
2025-02-14 10:32:06 +01:00
Sabyrzhan Tasbolatov
1db272864f x86/traps: move kmsan check after instrumentation_begin
During x86_64 kernel build with CONFIG_KMSAN, the objtool warns following:

  AR      built-in.a
  AR      vmlinux.a
  LD      vmlinux.o
vmlinux.o: warning: objtool: handle_bug+0x4: call to
    kmsan_unpoison_entry_regs() leaves .noinstr.text section
  OBJCOPY modules.builtin.modinfo
  GEN     modules.builtin
  MODPOST Module.symvers
  CC      .vmlinux.export.o

Moving kmsan_unpoison_entry_regs() _after_ instrumentation_begin() fixes
the warning.

There is decode_bug(regs->ip, &imm) is left before KMSAN unpoisoining, but
it has the return condition and if we include it after
instrumentation_begin() it results the warning "return with
instrumentation enabled", hence, I'm concerned that regs will not be KMSAN
unpoisoned if `ud_type == BUG_NONE` is true.

Link: https://lkml.kernel.org/r/20241016152407.3149001-1-snovitoll@gmail.com
Fixes: ba54d194f8 ("x86/traps: avoid KMSAN bugs originating from handle_bug()")
Signed-off-by: Sabyrzhan Tasbolatov <snovitoll@gmail.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Cc: Borislav Petkov (AMD) <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-10-28 21:40:39 -07:00
Linus Torvalds
b136021126 Updates for x86 FRED:
- Enable FRED right after init_mem_mapping() because at that point the
     early IDT fault handler is replaced by the real fault handler. The real
     fault handler retrieves the faulting address from the stack frame and
     not from CR2 when the FRED feature is set. But that obviously only
     works when FRED is enabled in the CPU as well.
 
   - Set SS to __KERNEL_DS when enabling FRED to prevent a corner case where
     ERETS can observe a SS mismatch and raises a #GP.
 -----BEGIN PGP SIGNATURE-----
 
 iQJHBAABCgAxFiEEQp8+kY+LLUocC4bMphj1TA10mKEFAmbpNZITHHRnbHhAbGlu
 dXRyb25peC5kZQAKCRCmGPVMDXSYobh3EACsU/WhmWG0pjqNs+92i/Hjd5QHRxX8
 WkyB+j0FQ3ZtQ0aqn73G/VxITxCMAE1fwC2iERlN/9eXjGXcwxeaM9upsMs9gq7v
 HmiOPSixn6hH7ulQ6WzDnM478pSnN4lmaZVY2ll1O3z8r79dW2Kz34zSqQCxDGcQ
 3sCJkHr7F0YClUaYxH/dok68F69aZXhU4V9URE30Ec74hnomYd4VuFkHwuA77rHG
 k81lHxSY9/Ttha91CPiK3/lU+lbehYNNZQ+PzUxkNmm9dlzXI8Vl5JRPJGIlYpWQ
 A9L1ZjV4kZcB+tcXPV1bOW+lVSefGVquAia5RgCyUylIFCOtsR/wCoezS3f17Zhf
 Ry+kfkYwuDgD0IYNVp6L3+Fx0LtBJT3BorhnS7YhhiqvLW0EpGe/bBzzRFntp4oR
 TmRAA3nNn3DBCky3rfGg0TWwqfvy/7c6SPY1Zw1SEmqtDdHB/DyKGt+BVQQ2kqWO
 tCtGAMjcE7Cfgca7mI7wILjY7MFirTQW0js6UL5mw22rhZxKV5S9m7N8KkUnFh3S
 acjQ1nL5ZBQ9cKdEGrLNHQjfSSc9ju7aXsGXm5c+vrqKbMG8+Nj+1cvzxaLL5xVY
 LLKACw5rl0LVXHU5H3IwvS+GMipklrmouikdoI4P8vHMd9GBquR4znO3MzqaLtg2
 F1IBXL07s2SYrw==
 =cKRu
 -----END PGP SIGNATURE-----

Merge tag 'x86-fred-2024-09-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 FRED updates from Thomas Gleixner:

 - Enable FRED right after init_mem_mapping() because at that point the
   early IDT fault handler is replaced by the real fault handler. The
   real fault handler retrieves the faulting address from the stack
   frame and not from CR2 when the FRED feature is set. But that
   obviously only works when FRED is enabled in the CPU as well.

 - Set SS to __KERNEL_DS when enabling FRED to prevent a corner case
   where ERETS can observe a SS mismatch and raises a #GP.

* tag 'x86-fred-2024-09-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/entry: Set FRED RSP0 on return to userspace instead of context switch
  x86/msr: Switch between WRMSRNS and WRMSR with the alternatives mechanism
  x86/entry: Test ti_work for zero before processing individual bits
  x86/fred: Set SS to __KERNEL_DS when enabling FRED
  x86/fred: Enable FRED right after init_mem_mapping()
  x86/fred: Move FRED RSP initialization into a separate function
  x86/fred: Parse cmdline param "fred=" in cpu_parse_early_param()
2024-09-17 14:55:59 +02:00
Xin Li (Intel)
a97756cbec x86/fred: Enable FRED right after init_mem_mapping()
On 64-bit init_mem_mapping() relies on the minimal page fault handler
provided by the early IDT mechanism. The real page fault handler is
installed right afterwards into the IDT.

This is problematic on CPUs which have X86_FEATURE_FRED set because the
real page fault handler retrieves the faulting address from the FRED
exception stack frame and not from CR2, but that does obviously not work
when FRED is not yet enabled in the CPU.

To prevent this enable FRED right after init_mem_mapping() without
interrupt stacks. Those are enabled later in trap_init() after the CPU
entry area is set up.

[ tglx: Encapsulate the FRED details ]

Fixes: 14619d912b ("x86/fred: FRED entry/exit and dispatch code")
Reported-by: Hou Wenlong <houwenlong.hwl@antgroup.com>
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Xin Li (Intel) <xin@zytor.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20240709154048.3543361-4-xin@zytor.com
2024-08-13 21:59:21 +02:00
Xin Li (Intel)
989b5cfaa7 x86/fred: Parse cmdline param "fred=" in cpu_parse_early_param()
Depending on whether FRED is enabled, sysvec_install() installs a system
interrupt handler into either into FRED's system vector dispatch table or
into the IDT.

However FRED can be disabled later in trap_init(), after sysvec_install()
has been invoked already; e.g., the HYPERVISOR_CALLBACK_VECTOR handler is
registered with sysvec_install() in kvm_guest_init(), which is called in
setup_arch() but way before trap_init().

IOW, there is a gap between FRED is available and available but disabled.
As a result, when FRED is available but disabled, early sysvec_install()
invocations fail to install the IDT handler resulting in spurious
interrupts.

Fix it by parsing cmdline param "fred=" in cpu_parse_early_param() to
ensure that FRED is disabled before the first sysvec_install() incovations.

Fixes: 3810da1271 ("x86/fred: Add a fred= cmdline param")
Reported-by: Hou Wenlong <houwenlong.hwl@antgroup.com>
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Xin Li (Intel) <xin@zytor.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20240709154048.3543361-2-xin@zytor.com
2024-08-13 21:59:21 +02:00
Gatlin Newhouse
7424fc6b86 x86/traps: Enable UBSAN traps on x86
Currently ARM64 extracts which specific sanitizer has caused a trap via
encoded data in the trap instruction. Clang on x86 currently encodes the
same data in the UD1 instruction but x86 handle_bug() and
is_valid_bugaddr() currently only look at UD2.

Bring x86 to parity with ARM64, similar to commit 25b84002af ("arm64:
Support Clang UBSAN trap codes for better reporting"). See the llvm
links for information about the code generation.

Enable the reporting of UBSAN sanitizer details on x86 compiled with clang
when CONFIG_UBSAN_TRAP=y by analysing UD1 and retrieving the type immediate
which is encoded by the compiler after the UD1.

[ tglx: Simplified it by moving the printk() into handle_bug() ]

Signed-off-by: Gatlin Newhouse <gatlin.newhouse@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/all/20240724000206.451425-1-gatlin.newhouse@gmail.com
Link: https://github.com/llvm/llvm-project/commit/c5978f42ec8e9#diff-bb68d7cd885f41cfc35843998b0f9f534adb60b415f647109e597ce448e92d9f
Link: https://github.com/llvm/llvm-project/blob/main/llvm/lib/Target/X86/X86InstrSystem.td#L27
2024-08-06 13:42:40 +02:00
Linus Torvalds
685d982112 Core x86 changes for v6.9:
- The biggest change is the rework of the percpu code,
   to support the 'Named Address Spaces' GCC feature,
   by Uros Bizjak:
 
    - This allows C code to access GS and FS segment relative
      memory via variables declared with such attributes,
      which allows the compiler to better optimize those accesses
      than the previous inline assembly code.
 
    - The series also includes a number of micro-optimizations
      for various percpu access methods, plus a number of
      cleanups of %gs accesses in assembly code.
 
    - These changes have been exposed to linux-next testing for
      the last ~5 months, with no known regressions in this area.
 
 - Fix/clean up __switch_to()'s broken but accidentally
   working handling of FPU switching - which also generates
   better code.
 
 - Propagate more RIP-relative addressing in assembly code,
   to generate slightly better code.
 
 - Rework the CPU mitigations Kconfig space to be less idiosyncratic,
   to make it easier for distros to follow & maintain these options.
 
 - Rework the x86 idle code to cure RCU violations and
   to clean up the logic.
 
 - Clean up the vDSO Makefile logic.
 
 - Misc cleanups and fixes.
 
 [ Please note that there's a higher number of merge commits in
   this branch (three) than is usual in x86 topic trees. This happened
   due to the long testing lifecycle of the percpu changes that
   involved 3 merge windows, which generated a longer history
   and various interactions with other core x86 changes that we
   felt better about to carry in a single branch. ]
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
 -----BEGIN PGP SIGNATURE-----
 
 iQJFBAABCgAvFiEEBpT5eoXrXCwVQwEKEnMQ0APhK1gFAmXvB0gRHG1pbmdvQGtl
 cm5lbC5vcmcACgkQEnMQ0APhK1jUqRAAqnEQPiabF5acQlHrwviX+cjSobDlqtH5
 9q2AQy9qaEHapzD0XMOxvFye6XIvehGOGxSPvk6CoviSxBND8rb56lvnsEZuLeBV
 Bo5QSIL2x42Zrvo11iPHwgXZfTIusU90sBuKDRFkYBAxY3HK2naMDZe8MAsYCUE9
 nwgHF8DDc/NYiSOXV8kosWoWpNIkoK/STyH5bvTQZMqZcwyZ49AIeP1jGZb/prbC
 e/rbnlrq5Eu6brpM7xo9kELO0Vhd34urV14KrrIpdkmUKytW2KIsyvW8D6fqgDBj
 NSaQLLcz0pCXbhF+8Nqvdh/1coR4L7Ymt08P1rfEjCsQgb/2WnSAGUQuC5JoGzaj
 ngkbFcZllIbD9gNzMQ1n4Aw5TiO+l9zxCqPC/r58Uuvstr+K9QKlwnp2+B3Q73Ft
 rojIJ04NJL6lCHdDgwAjTTks+TD2PT/eBWsDfJ/1pnUWttmv9IjMpnXD5sbHxoiU
 2RGGKnYbxXczYdq/ALYDWM6JXpfnJZcXL3jJi0IDcCSsb92xRvTANYFHnTfyzGfw
 EHkhbF4e4Vy9f6QOkSP3CvW5H26BmZS9DKG0J9Il5R3u2lKdfbb5vmtUmVTqHmAD
 Ulo5cWZjEznlWCAYSI/aIidmBsp9OAEvYd+X7Z5SBIgTfSqV7VWHGt0BfA1heiVv
 F/mednG0gGc=
 =3v4F
 -----END PGP SIGNATURE-----

Merge tag 'x86-core-2024-03-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull core x86 updates from Ingo Molnar:

 - The biggest change is the rework of the percpu code, to support the
   'Named Address Spaces' GCC feature, by Uros Bizjak:

      - This allows C code to access GS and FS segment relative memory
        via variables declared with such attributes, which allows the
        compiler to better optimize those accesses than the previous
        inline assembly code.

      - The series also includes a number of micro-optimizations for
        various percpu access methods, plus a number of cleanups of %gs
        accesses in assembly code.

      - These changes have been exposed to linux-next testing for the
        last ~5 months, with no known regressions in this area.

 - Fix/clean up __switch_to()'s broken but accidentally working handling
   of FPU switching - which also generates better code

 - Propagate more RIP-relative addressing in assembly code, to generate
   slightly better code

 - Rework the CPU mitigations Kconfig space to be less idiosyncratic, to
   make it easier for distros to follow & maintain these options

 - Rework the x86 idle code to cure RCU violations and to clean up the
   logic

 - Clean up the vDSO Makefile logic

 - Misc cleanups and fixes

* tag 'x86-core-2024-03-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (52 commits)
  x86/idle: Select idle routine only once
  x86/idle: Let prefer_mwait_c1_over_halt() return bool
  x86/idle: Cleanup idle_setup()
  x86/idle: Clean up idle selection
  x86/idle: Sanitize X86_BUG_AMD_E400 handling
  sched/idle: Conditionally handle tick broadcast in default_idle_call()
  x86: Increase brk randomness entropy for 64-bit systems
  x86/vdso: Move vDSO to mmap region
  x86/vdso/kbuild: Group non-standard build attributes and primary object file rules together
  x86/vdso: Fix rethunk patching for vdso-image-{32,64}.o
  x86/retpoline: Ensure default return thunk isn't used at runtime
  x86/vdso: Use CONFIG_COMPAT_32 to specify vdso32
  x86/vdso: Use $(addprefix ) instead of $(foreach )
  x86/vdso: Simplify obj-y addition
  x86/vdso: Consolidate targets and clean-files
  x86/bugs: Rename CONFIG_RETHUNK              => CONFIG_MITIGATION_RETHUNK
  x86/bugs: Rename CONFIG_CPU_SRSO             => CONFIG_MITIGATION_SRSO
  x86/bugs: Rename CONFIG_CPU_IBRS_ENTRY       => CONFIG_MITIGATION_IBRS_ENTRY
  x86/bugs: Rename CONFIG_CPU_UNRET_ENTRY      => CONFIG_MITIGATION_UNRET_ENTRY
  x86/bugs: Rename CONFIG_SLS                  => CONFIG_MITIGATION_SLS
  ...
2024-03-11 19:53:15 -07:00
Ingo Molnar
03c11eb3b1 Linux 6.8-rc4
-----BEGIN PGP SIGNATURE-----
 
 iQFSBAABCAA8FiEEq68RxlopcLEwq+PEeb4+QwBBGIYFAmXJK4UeHHRvcnZhbGRz
 QGxpbnV4LWZvdW5kYXRpb24ub3JnAAoJEHm+PkMAQRiGHsYH/jKmzKXDRsBCcw/Q
 HGUvFtpohWBOpN6efdf0nxilQisuyQrqKB9fnwvfcdE60VpqMJXFMdlFh/fonxPl
 JMbpk9y5uw48IJZA43NwTxUrjZ4wyWzv4ZF6YWa+5WdTAJpPLEPhhnLxcHOKklMr
 5Cm/7B/M7eB2BXBfc45b1pkKN22q9OXvjaKxZ+5wYmiMxS+GC8l8jiJ/WlHX78PR
 eLgsa1v732f2D7YF75wVhaoYepR+QzA9wTKqhjMNCEaVc2PQhA2JRsBXEt84qEIa
 FZigmf7LLc4ed9YA2XjRBZhAehe3cZVJZ1lasW37IATS921La2WfKuiysICJOtyT
 bGjK8tk=
 =Pt7W
 -----END PGP SIGNATURE-----

Merge tag 'v6.8-rc4' into x86/percpu, to resolve conflicts and refresh the branch

Conflicts:
	arch/x86/include/asm/percpu.h
	arch/x86/include/asm/text-patching.h

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2024-02-14 10:45:07 +01:00
H. Peter Anvin (Intel)
208d8c79fd x86/fred: Invoke FRED initialization code to enable FRED
Let cpu_init_exception_handling() call cpu_init_fred_exceptions() to
initialize FRED. However if FRED is unavailable or disabled, it falls
back to set up TSS IST and initialize IDT.

Co-developed-by: Xin Li <xin3.li@intel.com>
Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
Signed-off-by: Xin Li <xin3.li@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Tested-by: Shan Kang <shan.kang@intel.com>
Link: https://lore.kernel.org/r/20231205105030.8698-36-xin3.li@intel.com
2024-01-31 22:03:36 +01:00
H. Peter Anvin (Intel)
99fcc968e7 x86/fred: Add a debug fault entry stub for FRED
When occurred on different ring level, i.e., from user or kernel context,
stack, while kernel #DB on a dedicated stack. This is exactly how FRED
event delivery invokes an exception handler: ring 3 event on level 0
stack, i.e., current task stack; ring 0 event on the #DB dedicated stack
specified in the IA32_FRED_STKLVLS MSR. So unlike IDT, the FRED debug
exception entry stub doesn't do stack switch.

On a FRED system, the debug trap status information (DR6) is passed on
the stack, to avoid the problem of transient state. Furthermore, FRED
transitions avoid a lot of ugly corner cases the handling of which can,
and should be, skipped.

The FRED debug trap status information saved on the stack differs from
DR6 in both stickiness and polarity; it is exactly in the format which
debug_read_clear_dr6() returns for the IDT entry points.

Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
Signed-off-by: Xin Li <xin3.li@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Tested-by: Shan Kang <shan.kang@intel.com>
Link: https://lore.kernel.org/r/20231205105030.8698-24-xin3.li@intel.com
2024-01-31 22:02:15 +01:00
Xin Li
3810da1271 x86/fred: Add a fred= cmdline param
Let command line option "fred" accept multiple options to make it
easier to tweak its behavior.

Currently, two options 'on' and 'off' are allowed, and the default
behavior is to disable FRED. To enable FRED, append "fred=on" to the
kernel command line.

  [ bp: Use cpu_feature_enabled(), touch ups. ]

Signed-off-by: Xin Li <xin3.li@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Tested-by: Shan Kang <shan.kang@intel.com>
Link: https://lore.kernel.org/r/20231205105030.8698-9-xin3.li@intel.com
2024-01-30 18:19:20 +01:00
Linus Torvalds
0dde2bf67b IOMMU Updates for Linux v6.8
Including:
 
 	- Core changes:
 	  - Fix race conditions in device probe path
 	  - Retire IOMMU bus_ops
 	  - Support for passing custom allocators to page table drivers
 	  - Clean up Kconfig around IOMMU_SVA
 	  - Support for sharing SVA domains with all devices bound to
 	    a mm
 	  - Firmware data parsing cleanup
 	  - Tracing improvements for iommu-dma code
 	  - Some smaller fixes and cleanups
 
 	- ARM-SMMU drivers:
 	  - Device-tree binding updates:
 	     - Add additional compatible strings for Qualcomm SoCs
 	     - Document Adreno clocks for Qualcomm's SM8350 SoC
 	  - SMMUv2:
 	    - Implement support for the ->domain_alloc_paging() callback
 	    - Ensure Secure context is restored following suspend of Qualcomm SMMU
 	      implementation
 	  - SMMUv3:
 	    - Disable stalling mode for the "quiet" context descriptor
 	    - Minor refactoring and driver cleanups
 
 	 - Intel VT-d driver:
 	   - Cleanup and refactoring
 
 	 - AMD IOMMU driver:
 	   - Improve IO TLB invalidation logic
 	   - Small cleanups and improvements
 
 	 - Rockchip IOMMU driver:
 	   - DT binding update to add Rockchip RK3588
 
 	 - Apple DART driver:
 	   - Apple M1 USB4/Thunderbolt DART support
 	   - Cleanups
 
 	 - Virtio IOMMU driver:
 	   - Add support for iotlb_sync_map
 	   - Enable deferred IO TLB flushes
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCAAdFiEEr9jSbILcajRFYWYyK/BELZcBGuMFAmWecQoACgkQK/BELZcB
 GuN5ZxAAzC5QUKAzANx0puk7QhPpKKlbSvj6Q7iRgCLk00KJO1+VQh9v4ouCmXqF
 kn3Ko8gddjhtrgwN0OQ54F39cLUrp1SBemy71K5YOR+vu8VKtwtmawZGeeRZ+k+B
 Eohw58oaXTiR1maYvoLixLYczLrjklqyJOQ1vZ0GxFGxDqrFByAryHDgG/3OCpJx
 C9e6PsLbbfhfqA8Kv97iKcBqniGbXxAMuodqSUG0buQ3oZgfpIP6Bt3EgUzFGPGk
 3BTlYxowS/gkjUWd3fgjQFIFLTA01u9FhpA2Jb0a4v67pUCR64YxHN7rBQ6ZChtG
 kB9laQfU9re79RsHhqQzr0JT9x/eyq7pzGzjp5TV5TPW6IW+sqjMIPhzd9P08Ef7
 BclkCVobx0jSAHOhnnG4QJiKANr2Y2oM3HfsAJccMMY45RRhUKmVqM7jxMPfGn3A
 i+inlee73xTjZXJse1EWG1fmKKMLvX9LDEp4DyOfn9CqVT+7hpZvzPjfbGr937Rm
 JlwXhF3rQXEpOCagEsbt1vOf+V0e9QiCLf1Y2KpkIkDbE5wwSD/2qLm3tFhJG3oF
 fkW+J14Cid0pj+hY0afGe0kOUOIYlimu0nFmSf0pzMH+UktZdKogSfyb1gSDsy+S
 rsZRGPFhMJ832ExqhlDfxqBebqh+jsfKynlskui6Td5C9ZULaHA=
 =q751
 -----END PGP SIGNATURE-----

Merge tag 'iommu-updates-v6.8' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu

Pull iommu updates from Joerg Roedel:
 "Core changes:
   - Fix race conditions in device probe path
   - Retire IOMMU bus_ops
   - Support for passing custom allocators to page table drivers
   - Clean up Kconfig around IOMMU_SVA
   - Support for sharing SVA domains with all devices bound to a mm
   - Firmware data parsing cleanup
   - Tracing improvements for iommu-dma code
   - Some smaller fixes and cleanups

  ARM-SMMU drivers:
   - Device-tree binding updates:
      - Add additional compatible strings for Qualcomm SoCs
      - Document Adreno clocks for Qualcomm's SM8350 SoC
   - SMMUv2:
      - Implement support for the ->domain_alloc_paging() callback
      - Ensure Secure context is restored following suspend of Qualcomm
        SMMU implementation
   - SMMUv3:
      - Disable stalling mode for the "quiet" context descriptor
      - Minor refactoring and driver cleanups

  Intel VT-d driver:
   - Cleanup and refactoring

  AMD IOMMU driver:
   - Improve IO TLB invalidation logic
   - Small cleanups and improvements

  Rockchip IOMMU driver:
   - DT binding update to add Rockchip RK3588

  Apple DART driver:
   - Apple M1 USB4/Thunderbolt DART support
   - Cleanups

  Virtio IOMMU driver:
   - Add support for iotlb_sync_map
   - Enable deferred IO TLB flushes"

* tag 'iommu-updates-v6.8' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu: (66 commits)
  iommu: Don't reserve 0-length IOVA region
  iommu/vt-d: Move inline helpers to header files
  iommu/vt-d: Remove unused vcmd interfaces
  iommu/vt-d: Remove unused parameter of intel_pasid_setup_pass_through()
  iommu/vt-d: Refactor device_to_iommu() to retrieve iommu directly
  iommu/sva: Fix memory leak in iommu_sva_bind_device()
  dt-bindings: iommu: rockchip: Add Rockchip RK3588
  iommu/dma: Trace bounce buffer usage when mapping buffers
  iommu/arm-smmu: Convert to domain_alloc_paging()
  iommu/arm-smmu: Pass arm_smmu_domain to internal functions
  iommu/arm-smmu: Implement IOMMU_DOMAIN_BLOCKED
  iommu/arm-smmu: Convert to a global static identity domain
  iommu/arm-smmu: Reorganize arm_smmu_domain_add_master()
  iommu/arm-smmu-v3: Remove ARM_SMMU_DOMAIN_NESTED
  iommu/arm-smmu-v3: Master cannot be NULL in arm_smmu_write_strtab_ent()
  iommu/arm-smmu-v3: Add a type for the STE
  iommu/arm-smmu-v3: disable stall for quiet_cd
  iommu/qcom: restore IOMMU state if needed
  iommu/arm-smmu-qcom: Add QCM2290 MDSS compatible
  iommu/arm-smmu-qcom: Add missing GMU entry to match table
  ...
2024-01-18 15:16:57 -08:00
Tina Zhang
2396046d75 iommu: Add mm_get_enqcmd_pasid() helper function
mm_get_enqcmd_pasid() should be used by architecture code and closely
related to learn the PASID value that the x86 ENQCMD operation should
use for the mm.

For the moment SMMUv3 uses this without any connection to ENQCMD, it
will be cleaned up similar to how the prior patch made VT-d use the
PASID argument of set_dev_pasid().

The motivation is to replace mm->pasid with an iommu private data
structure that is introduced in a later patch.

Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Tina Zhang <tina.zhang@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20231027000525.1278806-4-tina.zhang@intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2023-12-12 10:11:29 +01:00
Jason Gunthorpe
8f23f5dba6 iommu: Change kconfig around IOMMU_SVA
Linus suggested that the kconfig here is confusing:

https://lore.kernel.org/all/CAHk-=wgUiAtiszwseM1p2fCJ+sC4XWQ+YN4TanFhUgvUqjr9Xw@mail.gmail.com/

Let's break it into three kconfigs controlling distinct things:

 - CONFIG_IOMMU_MM_DATA controls if the mm_struct has the additional
   fields for the IOMMU. Currently only PASID, but later patches store
   a struct iommu_mm_data *

 - CONFIG_ARCH_HAS_CPU_PASID controls if the arch needs the scheduling bit
   for keeping track of the ENQCMD instruction. x86 will select this if
   IOMMU_SVA is enabled

 - IOMMU_SVA controls if the IOMMU core compiles in the SVA support code
   for iommu driver use and the IOMMU exported API

This way ARM will not enable CONFIG_ARCH_HAS_CPU_PASID

Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20231027000525.1278806-2-tina.zhang@intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2023-12-12 10:11:27 +01:00
Uros Bizjak
13408c6ae6 x86/traps: Use current_top_of_stack() helper in traps.c
Use current_top_of_stack() helper in sync_regs() and vc_switch_off_ist()
instead of open-coding the reading of  the top_of_stack percpu variable
explicitly.

Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20231204210320.114429-2-ubizjak@gmail.com
2023-12-11 11:47:15 +01:00
Arnd Bergmann
f717a8d164 arch: include linux/cpu.h for trap_init() prototype
some architectures run into a -Wmissing-prototypes warning
for trap_init()

arch/microblaze/kernel/traps.c:21:6: warning: no previous prototype for 'trap_init' [-Wmissing-prototypes]

Include the right header to avoid this consistently, removing
the extra declarations on m68k and x86 that were added as local
workarounds already.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2023-11-23 11:32:31 +01:00
Linus Torvalds
df57721f9a Add x86 shadow stack support
Convert IBT selftest to asm to fix objtool warning
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEEV76QKkVc4xCGURexaDWVMHDJkrAFAmTv1QQACgkQaDWVMHDJ
 krAUwhAAn6TOwHJK8BSkHeiQhON1nrlP3c5cv0AyZ2NP8RYDrZrSZvhpYBJ6wgKC
 Cx5CGq5nn9twYsYS3KsktLKDfR3lRdsQ7K9qtyFtYiaeaVKo+7gEKl/K+klwai8/
 gninQWHk0zmSCja8Vi77q52WOMkQKapT8+vaON9EVDO8dVEi+CvhAIfPwMafuiwO
 Rk4X86SzoZu9FP79LcCg9XyGC/XbM2OG9eNUTSCKT40qTTKm5y4gix687NvAlaHR
 ko5MTsdl0Wfp6Qk0ohT74LnoA2c1g/FluvZIM33ci/2rFpkf9Hw7ip3lUXqn6CPx
 rKiZ+pVRc0xikVWkraMfIGMJfUd2rhelp8OyoozD7DB7UZw40Q4RW4N5tgq9Fhe9
 MQs3p1v9N8xHdRKl365UcOczUxNAmv4u0nV5gY/4FMC6VjldCl2V9fmqYXyzFS4/
 Ogg4FSd7c2JyGFKPs+5uXyi+RY2qOX4+nzHOoKD7SY616IYqtgKoz5usxETLwZ6s
 VtJOmJL0h//z0A7tBliB0zd+SQ5UQQBDC2XouQH2fNX2isJMn0UDmWJGjaHgK6Hh
 8jVp6LNqf+CEQS387UxckOyj7fu438hDky1Ggaw4YqowEOhQeqLVO4++x+HITrbp
 AupXfbJw9h9cMN63Yc0gVxXQ9IMZ+M7UxLtZ3Cd8/PVztNy/clA=
 =3UUm
 -----END PGP SIGNATURE-----

Merge tag 'x86_shstk_for_6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 shadow stack support from Dave Hansen:
 "This is the long awaited x86 shadow stack support, part of Intel's
  Control-flow Enforcement Technology (CET).

  CET consists of two related security features: shadow stacks and
  indirect branch tracking. This series implements just the shadow stack
  part of this feature, and just for userspace.

  The main use case for shadow stack is providing protection against
  return oriented programming attacks. It works by maintaining a
  secondary (shadow) stack using a special memory type that has
  protections against modification. When executing a CALL instruction,
  the processor pushes the return address to both the normal stack and
  to the special permission shadow stack. Upon RET, the processor pops
  the shadow stack copy and compares it to the normal stack copy.

  For more information, refer to the links below for the earlier
  versions of this patch set"

Link: https://lore.kernel.org/lkml/20220130211838.8382-1-rick.p.edgecombe@intel.com/
Link: https://lore.kernel.org/lkml/20230613001108.3040476-1-rick.p.edgecombe@intel.com/

* tag 'x86_shstk_for_6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (47 commits)
  x86/shstk: Change order of __user in type
  x86/ibt: Convert IBT selftest to asm
  x86/shstk: Don't retry vm_munmap() on -EINTR
  x86/kbuild: Fix Documentation/ reference
  x86/shstk: Move arch detail comment out of core mm
  x86/shstk: Add ARCH_SHSTK_STATUS
  x86/shstk: Add ARCH_SHSTK_UNLOCK
  x86: Add PTRACE interface for shadow stack
  selftests/x86: Add shadow stack test
  x86/cpufeatures: Enable CET CR4 bit for shadow stack
  x86/shstk: Wire in shadow stack interface
  x86: Expose thread features in /proc/$PID/status
  x86/shstk: Support WRSS for userspace
  x86/shstk: Introduce map_shadow_stack syscall
  x86/shstk: Check that signal frame is shadow stack mem
  x86/shstk: Check that SSP is aligned on sigreturn
  x86/shstk: Handle signals for shadow stack
  x86/shstk: Introduce routines modifying shstk
  x86/shstk: Handle thread shadow stack
  x86/shstk: Add user-mode shadow stack support
  ...
2023-08-31 12:20:12 -07:00
Borislav Petkov (AMD)
f58d6fbcb7 x86/CPU/AMD: Fix the DIV(0) initial fix attempt
Initially, it was thought that doing an innocuous division in the #DE
handler would take care to prevent any leaking of old data from the
divider but by the time the fault is raised, the speculation has already
advanced too far and such data could already have been used by younger
operations.

Therefore, do the innocuous division on every exit to userspace so that
userspace doesn't see any potentially old data from integer divisions in
kernel space.

Do the same before VMRUN too, to protect host data from leaking into the
guest too.

Fixes: 77245f1c3c ("x86/CPU/AMD: Do not leak quotient data after a division by 0")
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Cc: <stable@kernel.org>
Link: https://lore.kernel.org/r/20230811213824.10025-1-bp@alien8.de
2023-08-14 11:02:50 +02:00
Borislav Petkov (AMD)
77245f1c3c x86/CPU/AMD: Do not leak quotient data after a division by 0
Under certain circumstances, an integer division by 0 which faults, can
leave stale quotient data from a previous division operation on Zen1
microarchitectures.

Do a dummy division 0/1 before returning from the #DE exception handler
in order to avoid any leaks of potentially sensitive data.

Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Cc: <stable@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2023-08-09 07:55:00 -07:00
Rick Edgecombe
a5f6c2ace9 x86/shstk: Add user control-protection fault handler
A control-protection fault is triggered when a control-flow transfer
attempt violates Shadow Stack or Indirect Branch Tracking constraints.
For example, the return address for a RET instruction differs from the copy
on the shadow stack.

There already exists a control-protection fault handler for handling kernel
IBT faults. Refactor this fault handler into separate user and kernel
handlers, like the page fault handler. Add a control-protection handler
for usermode. To avoid ifdeffery, put them both in a new file cet.c, which
is compiled in the case of either of the two CET features supported in the
kernel: kernel IBT or user mode shadow stack. Move some static inline
functions from traps.c into a header so they can be used in cet.c.

Opportunistically fix a comment in the kernel IBT part of the fault
handler that is on the end of the line instead of preceding it.

Keep the same behavior for the kernel side of the fault handler, except for
converting a BUG to a WARN in the case of a #CP happening when the feature
is missing. This unifies the behavior with the new shadow stack code, and
also prevents the kernel from crashing under this situation which is
potentially recoverable.

The control-protection fault handler works in a similar way as the general
protection fault handler. It provides the si_code SEGV_CPERR to the signal
handler.

Co-developed-by: Yu-cheng Yu <yu-cheng.yu@intel.com>
Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com>
Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>
Tested-by: Pengfei Xu <pengfei.xu@intel.com>
Tested-by: John Allen <john.allen@amd.com>
Tested-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/all/20230613001108.3040476-28-rick.p.edgecombe%40intel.com
2023-08-02 15:01:50 -07:00
Kirill A. Shutemov
9f91164061 x86/traps: Fix load_unaligned_zeropad() handling for shared TDX memory
Commit c4e34dd99f ("x86: simplify load_unaligned_zeropad()
implementation") changes how exceptions around load_unaligned_zeropad()
handled.  The kernel now uses the fault_address in fixup_exception() to
verify the address calculations for the load_unaligned_zeropad().

It works fine for #PF, but breaks on #VE since no fault address is
passed down to fixup_exception().

Propagating ve_info.gla down to fixup_exception() resolves the issue.

See commit 1e7769653b ("x86/tdx: Handle load_unaligned_zeropad()
page-cross to a shared page") for more context.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reported-by: Michael Kelley <mikelley@microsoft.com>
Fixes: c4e34dd99f ("x86: simplify load_unaligned_zeropad() implementation")
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2023-07-25 15:29:01 -07:00
Rick Edgecombe
2da5b91fe4 x86/traps: Move control protection handler to separate file
Today the control protection handler is defined in traps.c and used only
for the kernel IBT feature. To reduce ifdeffery, move it to it's own file.
In future patches, functionality will be added to make this handler also
handle user shadow stack faults. So name the file cet.c.

No functional change.

Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>
Tested-by: Pengfei Xu <pengfei.xu@intel.com>
Tested-by: John Allen <john.allen@amd.com>
Tested-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/all/20230613001108.3040476-8-rick.p.edgecombe%40intel.com
2023-07-11 14:12:18 -07:00
Linus Torvalds
58390c8ce1 IOMMU Updates for Linux 6.4
Including:
 
 	- Convert to platform remove callback returning void
 
 	- Extend changing default domain to normal group
 
 	- Intel VT-d updates:
 	    - Remove VT-d virtual command interface and IOASID
 	    - Allow the VT-d driver to support non-PRI IOPF
 	    - Remove PASID supervisor request support
 	    - Various small and misc cleanups
 
 	- ARM SMMU updates:
 	    - Device-tree binding updates:
 	        * Allow Qualcomm GPU SMMUs to accept relevant clock properties
 	        * Document Qualcomm 8550 SoC as implementing an MMU-500
 	        * Favour new "qcom,smmu-500" binding for Adreno SMMUs
 
 	    - Fix S2CR quirk detection on non-architectural Qualcomm SMMU
 	      implementations
 
 	    - Acknowledge SMMUv3 PRI queue overflow when consuming events
 
 	    - Document (in a comment) why ATS is disabled for bypass streams
 
 	- AMD IOMMU updates:
 	    - 5-level page-table support
 	    - NUMA awareness for memory allocations
 
 	- Unisoc driver: Support for reattaching an existing domain
 
 	- Rockchip driver: Add missing set_platform_dma_ops callback
 
 	- Mediatek driver: Adjust the dma-ranges
 
 	- Various other small fixes and cleanups
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCAAdFiEEr9jSbILcajRFYWYyK/BELZcBGuMFAmRONeAACgkQK/BELZcB
 GuPmpw/8C9ruxQ0JU5rcDBXQGvos4gMmxlbELMrBpbbiTtdb35xchpKfdhnECGIF
 k2SrrcF40R/S82SyzNU/eZtGKirtcXvGFraUFgu/QdCcnnqpRHs+IJMXX2NJP+it
 +0wO1uiInt3CN1ERcR4F31cDKiWjDG8bvQVE5LIyiy4KrIU5ld2G91Fkaa0R13Au
 6H+/wKkcUC6OyaGE6wPx474xBkapT20vj5AIQuAWisXJJR0wbBon1sUTo/IRKsU+
 IkNxH0W+1PNImJ+crAdf/nkOlyqoChY4ww6cm07LrOsBLIsX5bCqXfL4HvKthElD
 MEgk2SN5kfjfR5Vf29W4hZVM1CT8VbhO41I7OzaZ6X6RU2PXoldPKlgKtZGeSKn1
 9bcMpSgB0BtbttvBevSkxTo5KHFozXS2DG3DFoMB3yFMme8Th0LrhBZ9oB7NIPNw
 ntMo4K75vviC6Vvzjy4Anj/+y+Zm3W6wDDP7F12O6WZLkK5s4hrSsHUm/MQnnKQP
 muJlG870RnSl73xUQZe3cuBxktXuJ3EHqqYIPE0npzvauu8hhWcis3opf2Y+U2s8
 aBCCIgp5kTKqjHLh2e4lNCKZf1/b/dhxRcRBQhpAIb8YsjMlIJyM+G8Jz6K6gBga
 5Ld+68UQ3oHJwoLV1HCFN8jbpQ9KZn1s9+h3yrYjRAcLNiFb3nU=
 =OvTo
 -----END PGP SIGNATURE-----

Merge tag 'iommu-updates-v6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu

Pull iommu updates from Joerg Roedel:

 - Convert to platform remove callback returning void

 - Extend changing default domain to normal group

 - Intel VT-d updates:
     - Remove VT-d virtual command interface and IOASID
     - Allow the VT-d driver to support non-PRI IOPF
     - Remove PASID supervisor request support
     - Various small and misc cleanups

 - ARM SMMU updates:
     - Device-tree binding updates:
         * Allow Qualcomm GPU SMMUs to accept relevant clock properties
         * Document Qualcomm 8550 SoC as implementing an MMU-500
         * Favour new "qcom,smmu-500" binding for Adreno SMMUs

     - Fix S2CR quirk detection on non-architectural Qualcomm SMMU
       implementations

     - Acknowledge SMMUv3 PRI queue overflow when consuming events

     - Document (in a comment) why ATS is disabled for bypass streams

 - AMD IOMMU updates:
     - 5-level page-table support
     - NUMA awareness for memory allocations

 - Unisoc driver: Support for reattaching an existing domain

 - Rockchip driver: Add missing set_platform_dma_ops callback

 - Mediatek driver: Adjust the dma-ranges

 - Various other small fixes and cleanups

* tag 'iommu-updates-v6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu: (82 commits)
  iommu: Remove iommu_group_get_by_id()
  iommu: Make iommu_release_device() static
  iommu/vt-d: Remove BUG_ON in dmar_insert_dev_scope()
  iommu/vt-d: Remove a useless BUG_ON(dev->is_virtfn)
  iommu/vt-d: Remove BUG_ON in map/unmap()
  iommu/vt-d: Remove BUG_ON when domain->pgd is NULL
  iommu/vt-d: Remove BUG_ON in handling iotlb cache invalidation
  iommu/vt-d: Remove BUG_ON on checking valid pfn range
  iommu/vt-d: Make size of operands same in bitwise operations
  iommu/vt-d: Remove PASID supervisor request support
  iommu/vt-d: Use non-privileged mode for all PASIDs
  iommu/vt-d: Remove extern from function prototypes
  iommu/vt-d: Do not use GFP_ATOMIC when not needed
  iommu/vt-d: Remove unnecessary checks in iopf disabling path
  iommu/vt-d: Move PRI handling to IOPF feature path
  iommu/vt-d: Move pfsid and ats_qdep calculation to device probe path
  iommu/vt-d: Move iopf code from SVA to IOPF enabling path
  iommu/vt-d: Allow SVA with device-specific IOPF
  dmaengine: idxd: Add enable/disable device IOPF feature
  arm64: dts: mt8186: Add dma-ranges for the parent "soc" node
  ...
2023-04-30 13:00:38 -07:00
Jacob Pan
fffaed1e24 iommu/ioasid: Rename INVALID_IOASID
INVALID_IOASID and IOMMU_PASID_INVALID are duplicated. Rename
INVALID_IOASID and consolidate since we are moving away from IOASID
infrastructure.

Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Link: https://lore.kernel.org/r/20230322200803.869130-7-jacob.jun.pan@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2023-03-31 10:03:27 +02:00
Kirill A. Shutemov
400b9b9344 iommu/sva: Replace pasid_valid() helper with mm_valid_pasid()
Kernel has few users of pasid_valid() and all but one checks if the
process has PASID allocated. The helper takes ioasid_t as the input.

Replace the helper with mm_valid_pasid() that takes mm_struct as the
argument. The only call that checks PASID that is not tied to mm_struct
is open-codded now.

This is preparatory patch. It helps avoid ifdeffery: no need to
dereference mm->pasid in generic code to check if the process has PASID.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/all/20230312112612.31869-11-kirill.shutemov%40linux.intel.com
2023-03-16 13:08:40 -07:00
Linus Torvalds
94a855111e - Add the call depth tracking mitigation for Retbleed which has
been long in the making. It is a lighterweight software-only fix for
 Skylake-based cores where enabling IBRS is a big hammer and causes a
 significant performance impact.
 
 What it basically does is, it aligns all kernel functions to 16 bytes
 boundary and adds a 16-byte padding before the function, objtool
 collects all functions' locations and when the mitigation gets applied,
 it patches a call accounting thunk which is used to track the call depth
 of the stack at any time.
 
 When that call depth reaches a magical, microarchitecture-specific value
 for the Return Stack Buffer, the code stuffs that RSB and avoids its
 underflow which could otherwise lead to the Intel variant of Retbleed.
 
 This software-only solution brings a lot of the lost performance back,
 as benchmarks suggest:
 
   https://lore.kernel.org/all/20220915111039.092790446@infradead.org/
 
 That page above also contains a lot more detailed explanation of the
 whole mechanism
 
 - Implement a new control flow integrity scheme called FineIBT which is
 based on the software kCFI implementation and uses hardware IBT support
 where present to annotate and track indirect branches using a hash to
 validate them
 
 - Other misc fixes and cleanups
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEEzv7L6UO9uDPlPSfHEsHwGGHeVUoFAmOZp5EACgkQEsHwGGHe
 VUrZFxAAvi/+8L0IYSK4mKJvixGbTFjxN/Swo2JVOfs34LqGUT6JaBc+VUMwZxdb
 VMTFIZ3ttkKEodjhxGI7oGev6V8UfhI37SmO2lYKXpQVjXXnMlv/M+Vw3teE38CN
 gopi+xtGnT1IeWQ3tc/Tv18pleJ0mh5HKWiW+9KoqgXj0wgF9x4eRYDz1TDCDA/A
 iaBzs56j8m/FSykZHnrWZ/MvjKNPdGlfJASUCPeTM2dcrXQGJ93+X2hJctzDte0y
 Nuiw6Y0htfFBE7xoJn+sqm5Okr+McoUM18/CCprbgSKYk18iMYm3ZtAi6FUQZS1A
 ua4wQCf49loGp15PO61AS5d3OBf5D3q/WihQRbCaJvTVgPp9sWYnWwtcVUuhMllh
 ZQtBU9REcVJ/22bH09Q9CjBW0VpKpXHveqQdqRDViLJ6v/iI6EFGmD24SW/VxyRd
 73k9MBGrL/dOf1SbEzdsnvcSB3LGzp0Om8o/KzJWOomrVKjBCJy16bwTEsCZEJmP
 i406m92GPXeaN1GhTko7vmF0GnkEdJs1GVCZPluCAxxbhHukyxHnrjlQjI4vC80n
 Ylc0B3Kvitw7LGJsPqu+/jfNHADC/zhx1qz/30wb5cFmFbN1aRdp3pm8JYUkn+l/
 zri2Y6+O89gvE/9/xUhMohzHsWUO7xITiBavewKeTP9GSWybWUs=
 =cRy1
 -----END PGP SIGNATURE-----

Merge tag 'x86_core_for_v6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 core updates from Borislav Petkov:

 - Add the call depth tracking mitigation for Retbleed which has been
   long in the making. It is a lighterweight software-only fix for
   Skylake-based cores where enabling IBRS is a big hammer and causes a
   significant performance impact.

   What it basically does is, it aligns all kernel functions to 16 bytes
   boundary and adds a 16-byte padding before the function, objtool
   collects all functions' locations and when the mitigation gets
   applied, it patches a call accounting thunk which is used to track
   the call depth of the stack at any time.

   When that call depth reaches a magical, microarchitecture-specific
   value for the Return Stack Buffer, the code stuffs that RSB and
   avoids its underflow which could otherwise lead to the Intel variant
   of Retbleed.

   This software-only solution brings a lot of the lost performance
   back, as benchmarks suggest:

       https://lore.kernel.org/all/20220915111039.092790446@infradead.org/

   That page above also contains a lot more detailed explanation of the
   whole mechanism

 - Implement a new control flow integrity scheme called FineIBT which is
   based on the software kCFI implementation and uses hardware IBT
   support where present to annotate and track indirect branches using a
   hash to validate them

 - Other misc fixes and cleanups

* tag 'x86_core_for_v6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (80 commits)
  x86/paravirt: Use common macro for creating simple asm paravirt functions
  x86/paravirt: Remove clobber bitmask from .parainstructions
  x86/debug: Include percpu.h in debugreg.h to get DECLARE_PER_CPU() et al
  x86/cpufeatures: Move X86_FEATURE_CALL_DEPTH from bit 18 to bit 19 of word 11, to leave space for WIP X86_FEATURE_SGX_EDECCSSA bit
  x86/Kconfig: Enable kernel IBT by default
  x86,pm: Force out-of-line memcpy()
  objtool: Fix weak hole vs prefix symbol
  objtool: Optimize elf_dirty_reloc_sym()
  x86/cfi: Add boot time hash randomization
  x86/cfi: Boot time selection of CFI scheme
  x86/ibt: Implement FineIBT
  objtool: Add --cfi to generate the .cfi_sites section
  x86: Add prefix symbols for function padding
  objtool: Add option to generate prefix symbols
  objtool: Avoid O(bloody terrible) behaviour -- an ode to libelf
  objtool: Slice up elf_create_section_symbol()
  kallsyms: Revert "Take callthunks into account"
  x86: Unconfuse CONFIG_ and X86_FEATURE_ namespaces
  x86/retpoline: Fix crash printing warning
  x86/paravirt: Fix a !PARAVIRT build warning
  ...
2022-12-14 15:03:00 -08:00