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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
This commit is contained in:
Uros Bizjak 2020-05-08 12:58:17 +02:00 committed by Borislav Petkov
parent 7e32a9dac9
commit 3d81b3d1e5
1 changed files with 8 additions and 18 deletions
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26
arch/x86/include/asm/archrandom.h
View File

@ -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;
}