diff options
| author | Uros Bizjak <ubizjak@gmail.com> | 2025-09-07 20:33:38 +0200 |
|---|---|---|
| committer | Borislav Petkov (AMD) <bp@alien8.de> | 2025-09-08 15:38:06 +0200 |
| commit | c6c973dbfa5e34b1572bcd1852adcad1b5d08fab (patch) | |
| tree | d7f0dfbf593ee77c79d6d3efe69c5877c446de98 /arch/x86/include/asm/cmpxchg.h | |
| parent | 13bdfb53aa04eeb8022af87288c5bc0a5d13a834 (diff) | |
x86/asm: Remove code depending on __GCC_ASM_FLAG_OUTPUTS__
The minimum supported GCC version is 8.1, which supports flag output operands
and always defines __GCC_ASM_FLAG_OUTPUTS__ macro.
Remove code depending on __GCC_ASM_FLAG_OUTPUTS__ and use the "=@ccCOND" flag
output operand directly.
Use the equivalent "=@ccz" instead of "=@cce" flag output operand for
CMPXCHG8B and CMPXCHG16B instructions. These instructions set a single flag
bit - the Zero flag - and "=@ccz" is used to distinguish the CC user from
comparison instructions, where set ZERO flag indeed means that the values are
equal.
Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20250905121723.GCaLrU04lP2A50PT-B@fat_crate.local
Diffstat (limited to 'arch/x86/include/asm/cmpxchg.h')
| -rw-r--r-- | arch/x86/include/asm/cmpxchg.h | 12 |
1 files changed, 4 insertions, 8 deletions
diff --git a/arch/x86/include/asm/cmpxchg.h b/arch/x86/include/asm/cmpxchg.h index b61f32c3459f..a88b06f1c35e 100644 --- a/arch/x86/include/asm/cmpxchg.h +++ b/arch/x86/include/asm/cmpxchg.h @@ -166,8 +166,7 @@ extern void __add_wrong_size(void) { \ volatile u8 *__ptr = (volatile u8 *)(_ptr); \ asm_inline volatile(lock "cmpxchgb %[new], %[ptr]" \ - CC_SET(z) \ - : CC_OUT(z) (success), \ + : "=@ccz" (success), \ [ptr] "+m" (*__ptr), \ [old] "+a" (__old) \ : [new] "q" (__new) \ @@ -178,8 +177,7 @@ extern void __add_wrong_size(void) { \ volatile u16 *__ptr = (volatile u16 *)(_ptr); \ asm_inline volatile(lock "cmpxchgw %[new], %[ptr]" \ - CC_SET(z) \ - : CC_OUT(z) (success), \ + : "=@ccz" (success), \ [ptr] "+m" (*__ptr), \ [old] "+a" (__old) \ : [new] "r" (__new) \ @@ -190,8 +188,7 @@ extern void __add_wrong_size(void) { \ volatile u32 *__ptr = (volatile u32 *)(_ptr); \ asm_inline volatile(lock "cmpxchgl %[new], %[ptr]" \ - CC_SET(z) \ - : CC_OUT(z) (success), \ + : "=@ccz" (success), \ [ptr] "+m" (*__ptr), \ [old] "+a" (__old) \ : [new] "r" (__new) \ @@ -202,8 +199,7 @@ extern void __add_wrong_size(void) { \ volatile u64 *__ptr = (volatile u64 *)(_ptr); \ asm_inline volatile(lock "cmpxchgq %[new], %[ptr]" \ - CC_SET(z) \ - : CC_OUT(z) (success), \ + : "=@ccz" (success), \ [ptr] "+m" (*__ptr), \ [old] "+a" (__old) \ : [new] "r" (__new) \ |