linux-stable.git/arch/x86/include/asm/bug.h, branch linux-rolling-stable

x86/bug: Add printf() validation to HAVE_ARCH_BUG_FORMAT_ARGS WARNs

2026-07-24T14:19:04+00:00

[ Upstream commit 40c4b47f41b95dff743c841536cb64014e65ef0c ]

Add explicit printf() validation for x86-64's newfangled WARN
implementation, as most (all?) compilers fail to detect basic formatting
issues without the annotation.  E.g. even goofs like printing a u64 as a
string aren't detected:

  WARN_ONCE(1, "Bad message, %s", vcpu->arch.last_guest_tsc);

32-bit x86 doesn't support HAVE_ARCH_BUG_FORMAT_ARGS and uses generic
implementations that provide printf() validation. This means there's
now a big blind spot is code that is strictly x86-64. Inconveniently,
new features are also frequently x86-64-only.

Fix the blind 64-bit blind spot.

[ dhansen: changelog tweaks to flesh out the 64-bit-only details ]

Fixes: 5b472b6e5bd9 ("x86_64/bug: Implement __WARN_printf()")
Fixes: 11bb4944f014 ("x86/bug: Implement WARN_ONCE()")
Signed-off-by: Sean Christopherson 
Signed-off-by: Dave Hansen 
Acked-by: Dave Hansen 
Link: https://lore.kernel.org/all/adc1IrD8uqWdaOKv@yzhao56-desk.sh.intel.com
Link: https://patch.msgid.link/20260423145419.459988-2-seanjc@google.com
Signed-off-by: Sasha Levin

x86/headers: Replace ASSEMBLY stragglers with ASSEMBLER

2026-02-23T10:19:12+00:00

After converting the __ASSEMBLY__ statements to __ASSEMBLER__ in
commit 24a295e4ef1ca ("x86/headers: Replace __ASSEMBLY__ with
__ASSEMBLER__ in non-UAPI headers"), some new code has been
added that uses __ASSEMBLY__ again. Convert these stragglers, too.

This is a mechanical patch, done with a simple "sed -i" command.

Signed-off-by: Thomas Huth 
Signed-off-by: Peter Zijlstra (Intel) 
Link: https://patch.msgid.link/20251218182029.166993-1-thuth@redhat.com

Merge tag 'x86-urgent-2025-12-21' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2025-12-21T22:41:29+00:00

Pull x86 fixes from Ingo Molnar:

 - Fix FPU core dumps on certain CPU models

 - Fix htmldocs build warning

 - Export TLB tracing event name via header

 - Remove unused constant from 

 - Fix comments

 - Fix whitespace noise in documentation

 - Fix variadic structure's definition to un-confuse UBSAN

 - Fix posted MSI interrupts irq_retrigger() bug

 - Fix asm build failure with older GCC builds

* tag 'x86-urgent-2025-12-21' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/bug: Fix old GCC compile fails
  x86/msi: Make irq_retrigger() functional for posted MSI
  x86/platform/uv: Fix UBSAN array-index-out-of-bounds
  mm: Remove tlb_flush_reason::NR_TLB_FLUSH_REASONS from 
  x86/mm/tlb/trace: Export the TLB_REMOTE_WRONG_CPU enum in 
  x86/sgx: Remove unmatched quote in __sgx_encl_extend function comment
  x86/boot/Documentation: Fix whitespace noise in boot.rst
  x86/fpu: Fix FPU state core dump truncation on CPUs with no extended xfeatures
  x86/boot/Documentation: Fix htmldocs build warning due to malformed table in boot.rst

x86/bug: Fix old GCC compile fails

2025-12-18T10:55:40+00:00

For some mysterious reasons the GCC 8 and 9 preprocessor manages to
sporadically fumble _ASM_BYTES(0x0f, 0x0b):

$ grep ".byte[ ]*0x0f" defconfig-build/drivers/net/wireless/realtek/rtlwifi/base.s
        1:       .byte0x0f,0x0b ;
        1:       .byte 0x0f,0x0b ;

which makes the assembler upset and all that. While there are more
_ASM_BYTES() users (notably the NOP instructions), those don't seem
affected. Therefore replace the offending ASM_UD2 with one using the
ud2 mnemonic.

Reported-by: Jean Delvare 
Suggested-by: Uros Bizjak 
Fixes: 85a2d4a890dc ("x86,ibt: Use UDB instead of 0xEA")
Cc: stable@kernel.org
Signed-off-by: Peter Zijlstra (Intel) 
Link: https://patch.msgid.link/20251218104659.GT3911114@noisy.programming.kicks-ass.net

arch/x86: replace "__auto_type" with "auto"

2025-12-08T23:32:15+00:00

Replace instances of "__auto_type" with "auto" in:

	arch/x86/include/asm/bug.h
	arch/x86/include/asm/string_64.h
	arch/x86/include/asm/uaccess_64.h

Signed-off-by: H. Peter Anvin (Intel)

objtool: Remove newlines and tabs from annotation macros

2025-12-03T18:42:37+00:00

Remove newlines and tabs from the annotation macros so the invoking code
can insert them as needed to match the style of the surrounding code.

Signed-off-by: Josh Poimboeuf 
Signed-off-by: Ingo Molnar 
Cc: Linus Torvalds 
Link: https://patch.msgid.link/66305834c2eb78f082217611b756231ae9c0b555.1764694625.git.jpoimboe@kernel.org

x86/bugs: Make i386 use GENERIC_BUG_RELATIVE_POINTERS

2025-11-27T08:32:48+00:00

Linus figured less #ifdef is more better and making x86-32 use
GENERIC_BUG_RELATIVE_POINTERS removes one layer of macro magic from
the bug.h bits.

Suggested-by: Linus Torvalds 
Signed-off-by: Peter Zijlstra (Intel)

x86/bug: Fix BUG_FORMAT vs KASLR

2025-11-27T08:32:47+00:00

Encoding a relative NULL pointer doesn't work for KASLR, when the
whole kernel image gets shifted, the __bug_table and the target string
get shifted by the same amount and the relative offset is preserved.

However when the target is an absolute 0 value and the __bug_table
gets moved about, the end result in a pointer equivalent to
kaslr_offset(), not NULL.

Notably, this will generate SHN_UNDEF relocations, and Ard would
really like to not have those at all.

Use the empty string to denote no-string.

Suggested-by: Linus Torvalds 
Cc: Ard Biesheuvel 
Signed-off-by: Peter Zijlstra (Intel)

x86_64/bug: Inline the UD1

2025-11-24T19:23:25+00:00

(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) 
Link: https://patch.msgid.link/20251110115758.456717741@infradead.org

x86/bug: Implement WARN_ONCE()