From 3d81b3d1e55a518837c3d1f722c6d93abe34aa85 Mon Sep 17 00:00:00 2001 From: Uros Bizjak Date: Fri, 8 May 2020 12:58:17 +0200 Subject: [PATCH] x86/cpu: Use RDRAND and RDSEED mnemonics in archrandom.h Current minimum required version of binutils is 2.23, which supports RDRAND and RDSEED instruction mnemonics. Replace the byte-wise specification of RDRAND and RDSEED with these proper mnemonics. Signed-off-by: Uros Bizjak Signed-off-by: Borislav Petkov Reviewed-by: H. Peter Anvin (Intel) Acked-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/20200508105817.207887-1-ubizjak@gmail.com --- arch/x86/include/asm/archrandom.h | 26 ++++++++------------------ 1 file changed, 8 insertions(+), 18 deletions(-) diff --git a/arch/x86/include/asm/archrandom.h b/arch/x86/include/asm/archrandom.h index 7a4bb1bd4bdb..ebc248e49549 100644 --- a/arch/x86/include/asm/archrandom.h +++ b/arch/x86/include/asm/archrandom.h @@ -15,16 +15,6 @@ #define RDRAND_RETRY_LOOPS 10 -#define RDRAND_INT ".byte 0x0f,0xc7,0xf0" -#define RDSEED_INT ".byte 0x0f,0xc7,0xf8" -#ifdef CONFIG_X86_64 -# define RDRAND_LONG ".byte 0x48,0x0f,0xc7,0xf0" -# define RDSEED_LONG ".byte 0x48,0x0f,0xc7,0xf8" -#else -# define RDRAND_LONG RDRAND_INT -# define RDSEED_LONG RDSEED_INT -#endif - /* Unconditional execution of RDRAND and RDSEED */ static inline bool __must_check rdrand_long(unsigned long *v) @@ -32,9 +22,9 @@ static inline bool __must_check rdrand_long(unsigned long *v) bool ok; unsigned int retry = RDRAND_RETRY_LOOPS; do { - asm volatile(RDRAND_LONG + asm volatile("rdrand %[out]" CC_SET(c) - : CC_OUT(c) (ok), "=a" (*v)); + : CC_OUT(c) (ok), [out] "=r" (*v)); if (ok) return true; } while (--retry); @@ -46,9 +36,9 @@ static inline bool __must_check rdrand_int(unsigned int *v) bool ok; unsigned int retry = RDRAND_RETRY_LOOPS; do { - asm volatile(RDRAND_INT + asm volatile("rdrand %[out]" CC_SET(c) - : CC_OUT(c) (ok), "=a" (*v)); + : CC_OUT(c) (ok), [out] "=r" (*v)); if (ok) return true; } while (--retry); @@ -58,18 +48,18 @@ static inline bool __must_check rdrand_int(unsigned int *v) static inline bool __must_check rdseed_long(unsigned long *v) { bool ok; - asm volatile(RDSEED_LONG + asm volatile("rdseed %[out]" CC_SET(c) - : CC_OUT(c) (ok), "=a" (*v)); + : CC_OUT(c) (ok), [out] "=r" (*v)); return ok; } static inline bool __must_check rdseed_int(unsigned int *v) { bool ok; - asm volatile(RDSEED_INT + asm volatile("rdseed %[out]" CC_SET(c) - : CC_OUT(c) (ok), "=a" (*v)); + : CC_OUT(c) (ok), [out] "=r" (*v)); return ok; } -- 2.39.5