diff options
| author | Uros Bizjak <[email protected]> | 2025-09-07 18:33:38 +0000 |
|---|---|---|
| committer | Borislav Petkov (AMD) <[email protected]> | 2025-09-08 13:38:06 +0000 |
| commit | c6c973dbfa5e34b1572bcd1852adcad1b5d08fab (patch) | |
| tree | d7f0dfbf593ee77c79d6d3efe69c5877c446de98 /arch/x86/boot/string.c | |
| parent | x86/sgx: Use ENCLS mnemonic in <kernel/cpu/sgx/encls.h> (diff) | |
| download | kernel-c6c973dbfa5e34b1572bcd1852adcad1b5d08fab.tar.gz kernel-c6c973dbfa5e34b1572bcd1852adcad1b5d08fab.zip | |
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 <[email protected]>
Signed-off-by: Borislav Petkov (AMD) <[email protected]>
Link: https://lore.kernel.org/r/20250905121723.GCaLrU04lP2A50PT-B@fat_crate.local
Diffstat (limited to 'arch/x86/boot/string.c')
| -rw-r--r-- | arch/x86/boot/string.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/x86/boot/string.c b/arch/x86/boot/string.c index f35369bb14c5..b25c6a9303b7 100644 --- a/arch/x86/boot/string.c +++ b/arch/x86/boot/string.c @@ -32,8 +32,8 @@ int memcmp(const void *s1, const void *s2, size_t len) { bool diff; - asm("repe cmpsb" CC_SET(nz) - : CC_OUT(nz) (diff), "+D" (s1), "+S" (s2), "+c" (len)); + asm("repe cmpsb" + : "=@ccnz" (diff), "+D" (s1), "+S" (s2), "+c" (len)); return diff; } |