From c6c973dbfa5e34b1572bcd1852adcad1b5d08fab Mon Sep 17 00:00:00 2001 From: Uros Bizjak Date: Sun, 7 Sep 2025 20:33:38 +0200 Subject: 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 Signed-off-by: Borislav Petkov (AMD) Link: https://lore.kernel.org/r/20250905121723.GCaLrU04lP2A50PT-B@fat_crate.local --- arch/x86/boot/boot.h | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'arch/x86/boot/boot.h') diff --git a/arch/x86/boot/boot.h b/arch/x86/boot/boot.h index 60580836daf7..a3c58ebe3662 100644 --- a/arch/x86/boot/boot.h +++ b/arch/x86/boot/boot.h @@ -155,15 +155,15 @@ static inline void wrgs32(u32 v, addr_t addr) static inline bool memcmp_fs(const void *s1, addr_t s2, size_t len) { bool diff; - asm volatile("fs repe cmpsb" CC_SET(nz) - : CC_OUT(nz) (diff), "+D" (s1), "+S" (s2), "+c" (len)); + asm volatile("fs repe cmpsb" + : "=@ccnz" (diff), "+D" (s1), "+S" (s2), "+c" (len)); return diff; } static inline bool memcmp_gs(const void *s1, addr_t s2, size_t len) { bool diff; - asm volatile("gs repe cmpsb" CC_SET(nz) - : CC_OUT(nz) (diff), "+D" (s1), "+S" (s2), "+c" (len)); + asm volatile("gs repe cmpsb" + : "=@ccnz" (diff), "+D" (s1), "+S" (s2), "+c" (len)); return diff; } -- cgit v1.2.3