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authorUros Bizjak <ubizjak@gmail.com>2020-05-08 12:58:17 +0200
committerBorislav Petkov <bp@suse.de>2020-05-18 19:50:47 +0200
commit3d81b3d1e55a518837c3d1f722c6d93abe34aa85 (patch)
tree3b2c2f80180aa76855ce696c5c5cadb63bb81602
parent7e32a9dac9926241d56851e1517c9391d39fb48e (diff)
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 <ubizjak@gmail.com> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: H. Peter Anvin (Intel) <hpa@zytor.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20200508105817.207887-1-ubizjak@gmail.com
-rw-r--r--arch/x86/include/asm/archrandom.h26
1 files 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;
}