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x86/asm: Remove %P operand modifier from altinstr asm templates

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The "P" asm operand modifier is a x86 target-specific modifier.

For x86_64, when used with a symbol reference, the "%P" modifier
emits "sym" instead of "sym(%rip)". This property is currently
used to prevent %RIP-relative addressing in .altinstr sections.

%RIP-relative addresses are nowadays correctly handled in .altinstr
sections, so remove %P operand modifier from altinstr asm templates.

Also note that unlike GCC, clang emits %rip-relative symbol
reference with "P" asm operand modifier, so the patch also unifies
symbol handling with both compilers.

No functional changes intended.

Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Link: https://lore.kernel.org/r/20240319104418.284519-2-ubizjak@gmail.com
This commit is contained in:
Uros Bizjak 2024-03-19 11:40:12 +01:00 committed by Ingo Molnar
parent 4ae3dc83b0
commit a3ff53167c
3 changed files with 6 additions and 6 deletions
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2
arch/x86/include/asm/apic.h
View File

@ -91,7 +91,7 @@ static inline void native_apic_mem_write(u32 reg, u32 v)
{
volatile u32 *addr = (volatile u32 *)(APIC_BASE + reg);
alternative_io("movl %0, %P1", "xchgl %0, %P1", X86_BUG_11AP,
alternative_io("movl %0, %1", "xchgl %0, %1", X86_BUG_11AP,
ASM_OUTPUT2("=r" (v), "=m" (*addr)),
ASM_OUTPUT2("0" (v), "m" (*addr)));
}

6
arch/x86/include/asm/processor.h
View File

@ -587,7 +587,7 @@ extern char ignore_fpu_irq;
# define BASE_PREFETCH ""
# define ARCH_HAS_PREFETCH
#else
# define BASE_PREFETCH "prefetcht0 %P1"
# define BASE_PREFETCH "prefetcht0 %1"
#endif
/*
@ -598,7 +598,7 @@ extern char ignore_fpu_irq;
*/
static inline void prefetch(const void *x)
{
alternative_input(BASE_PREFETCH, "prefetchnta %P1",
alternative_input(BASE_PREFETCH, "prefetchnta %1",
X86_FEATURE_XMM,
"m" (*(const char *)x));
}
@ -610,7 +610,7 @@ static inline void prefetch(const void *x)
*/
static __always_inline void prefetchw(const void *x)
{
alternative_input(BASE_PREFETCH, "prefetchw %P1",
alternative_input(BASE_PREFETCH, "prefetchw %1",
X86_FEATURE_3DNOWPREFETCH,
"m" (*(const char *)x));
}

4
arch/x86/include/asm/special_insns.h
View File

@ -182,8 +182,8 @@ static __always_inline void clflush(volatile void *__p)
static inline void clflushopt(volatile void *__p)
{
alternative_io(".byte 0x3e; clflush %P0",
".byte 0x66; clflush %P0",
alternative_io(".byte 0x3e; clflush %0",
".byte 0x66; clflush %0",
X86_FEATURE_CLFLUSHOPT,
"+m" (*(volatile char __force *)__p));
}