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Commit c70e1b47 authored by Borislav Petkov's avatar Borislav Petkov
Browse files

x86/asm: Use alternative_2() in rdtsc_barrier() 



... now that we have it.

Acked-by: default avatarAndy Lutomirski <luto@amacapital.net>
Cc: Richard Weinberger <richard@nod.at>
Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
parent 6620ef28

arch/x86/include/asm/barrier.h

+2 −4
Original line number Diff line number Diff line
@@ -95,13 +95,11 @@ do { \ 
 * Stop RDTSC speculation. This is needed when you need to use RDTSC

 * (or get_cycles or vread that possibly accesses the TSC) in a defined

 * code region.

 *

 * (Could use an alternative three way for this if there was one.)

 */

static __always_inline void rdtsc_barrier(void)

{

	alternative(ASM_NOP3, "mfence", X86_FEATURE_MFENCE_RDTSC);

	alternative(ASM_NOP3, "lfence", X86_FEATURE_LFENCE_RDTSC);

	alternative_2("", "mfence", X86_FEATURE_MFENCE_RDTSC,

			  "lfence", X86_FEATURE_LFENCE_RDTSC);

}



#endif /* _ASM_X86_BARRIER_H */

arch/x86/um/asm/barrier.h

+2 −2
Original line number Diff line number Diff line
@@ -64,8 +64,8 @@ 
 */

static inline void rdtsc_barrier(void)

{

	alternative(ASM_NOP3, "mfence", X86_FEATURE_MFENCE_RDTSC);

	alternative(ASM_NOP3, "lfence", X86_FEATURE_LFENCE_RDTSC);

	alternative_2("", "mfence", X86_FEATURE_MFENCE_RDTSC,

			  "lfence", X86_FEATURE_LFENCE_RDTSC);

}



#endif