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| author | Ingo Molnar <mingo@kernel.org> | 2018-02-06 23:12:31 +0300 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2018-02-06 23:12:31 +0300 |
| commit | 82845079160817cc6ac64e5321bbd935e0a47b3a (patch) | |
| tree | 0886d1d52428e9db14536cae4b37db896e7c360a /arch/x86/include/asm/barrier.h | |
| parent | 32e839dda3ba576943365f0f5817ce5c843137dc (diff) | |
| parent | 68c5735eaa5e680e701c9a2d1e3c7880bdf5ab66 (diff) | |
| download | linux-82845079160817cc6ac64e5321bbd935e0a47b3a.tar.xz | |
Merge branch 'linus' into sched/urgent, to resolve conflicts
Conflicts:
arch/arm64/kernel/entry.S
arch/x86/Kconfig
include/linux/sched/mm.h
kernel/fork.c
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/include/asm/barrier.h')
| -rw-r--r-- | arch/x86/include/asm/barrier.h | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/arch/x86/include/asm/barrier.h b/arch/x86/include/asm/barrier.h index 7fb336210e1b..30d406146016 100644 --- a/arch/x86/include/asm/barrier.h +++ b/arch/x86/include/asm/barrier.h @@ -24,6 +24,34 @@ #define wmb() asm volatile("sfence" ::: "memory") #endif +/** + * array_index_mask_nospec() - generate a mask that is ~0UL when the + * bounds check succeeds and 0 otherwise + * @index: array element index + * @size: number of elements in array + * + * Returns: + * 0 - (index < size) + */ +static inline unsigned long array_index_mask_nospec(unsigned long index, + unsigned long size) +{ + unsigned long mask; + + asm ("cmp %1,%2; sbb %0,%0;" + :"=r" (mask) + :"r"(size),"r" (index) + :"cc"); + return mask; +} + +/* Override the default implementation from linux/nospec.h. */ +#define array_index_mask_nospec array_index_mask_nospec + +/* Prevent speculative execution past this barrier. */ +#define barrier_nospec() alternative_2("", "mfence", X86_FEATURE_MFENCE_RDTSC, \ + "lfence", X86_FEATURE_LFENCE_RDTSC) + #ifdef CONFIG_X86_PPRO_FENCE #define dma_rmb() rmb() #else |