diff options
| author | Peter Zijlstra <peterz@infradead.org> | 2025-06-07 10:06:40 +0200 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2025-11-24 20:23:25 +0100 |
| commit | 860238af7a3348225de228dc0f33a7d631638333 (patch) | |
| tree | d9b6d53173913cb4953fe989bb76afc369ad6a0f /arch/x86/include/asm/bug.h | |
| parent | 11bb4944f014d756f35261f5afcb346901ef1efa (diff) | |
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
Diffstat (limited to 'arch/x86/include/asm/bug.h')
| -rw-r--r-- | arch/x86/include/asm/bug.h | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/arch/x86/include/asm/bug.h b/arch/x86/include/asm/bug.h index 87199e6633f9..d0a96ff5c02c 100644 --- a/arch/x86/include/asm/bug.h +++ b/arch/x86/include/asm/bug.h @@ -140,6 +140,9 @@ do { \ #ifdef HAVE_ARCH_BUG_FORMAT_ARGS #ifndef __ASSEMBLY__ +#include <linux/static_call_types.h> +DECLARE_STATIC_CALL(WARN_trap, __WARN_trap); + struct pt_regs; struct sysv_va_list { /* from AMD64 System V ABI */ unsigned int gp_offset; @@ -171,7 +174,7 @@ extern void *__warn_args(struct arch_va_list *args, struct pt_regs *regs); #define __WARN_print_arg(flags, format, arg...) \ do { \ int __flags = (flags) | BUGFLAG_WARNING | BUGFLAG_ARGS ; \ - __WARN_trap(__WARN_bug_entry(__flags, format), ## arg); \ + static_call_mod(WARN_trap)(__WARN_bug_entry(__flags, format), ## arg); \ asm (""); /* inhibit tail-call optimization */ \ } while (0) |