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/uaccess.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/uaccess.h')
| -rw-r--r-- | arch/x86/include/asm/uaccess.h | 7 |
1 files changed, 3 insertions, 4 deletions
diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h index 3a7755c1a441..91a3fb8ae7ff 100644 --- a/arch/x86/include/asm/uaccess.h +++ b/arch/x86/include/asm/uaccess.h @@ -378,7 +378,7 @@ do { \ asm_goto_output("\n" \ "1: " LOCK_PREFIX "cmpxchg"itype" %[new], %[ptr]\n"\ _ASM_EXTABLE_UA(1b, %l[label]) \ - : CC_OUT(z) (success), \ + : "=@ccz" (success), \ [ptr] "+m" (*_ptr), \ [old] "+a" (__old) \ : [new] ltype (__new) \ @@ -397,7 +397,7 @@ do { \ asm_goto_output("\n" \ "1: " LOCK_PREFIX "cmpxchg8b %[ptr]\n" \ _ASM_EXTABLE_UA(1b, %l[label]) \ - : CC_OUT(z) (success), \ + : "=@ccz" (success), \ "+A" (__old), \ [ptr] "+m" (*_ptr) \ : "b" ((u32)__new), \ @@ -417,11 +417,10 @@ do { \ __typeof__(*(_ptr)) __new = (_new); \ asm volatile("\n" \ "1: " LOCK_PREFIX "cmpxchg"itype" %[new], %[ptr]\n"\ - CC_SET(z) \ "2:\n" \ _ASM_EXTABLE_TYPE_REG(1b, 2b, EX_TYPE_EFAULT_REG, \ %[errout]) \ - : CC_OUT(z) (success), \ + : "=@ccz" (success), \ [errout] "+r" (__err), \ [ptr] "+m" (*_ptr), \ [old] "+a" (__old) \ |