diff options
| author | Russell King <rmk+kernel@armlinux.org.uk> | 2018-05-11 15:06:58 +0100 |
|---|---|---|
| committer | Tao Huang <huangtao@rock-chips.com> | 2018-12-12 11:05:35 +0800 |
| commit | 7a633b2249a83678ebe58bfffc47dbd2b1bddb8b (patch) | |
| tree | fb8c5bbfb8c23d9a746980f89a6a0e79757f7b92 /arch/arm/include | |
| parent | 76e84854a64de8b4c903ba08d89000a688623687 (diff) | |
UPSTREAM: ARM: spectre-v1: add array_index_mask_nospec() implementation
Add an implementation of the array_index_mask_nospec() function for
mitigating Spectre variant 1 throughout the kernel.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Boot-tested-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Tony Lindgren <tony@atomide.com>
(cherry picked from commit 1d4238c56f9816ce0f9c8dbe42d7f2ad81cb6613)
Change-Id: I69fc8c673578a937a06cfdf85ae73492d25d069f
Diffstat (limited to 'arch/arm/include')
| -rw-r--r-- | arch/arm/include/asm/barrier.h | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/arch/arm/include/asm/barrier.h b/arch/arm/include/asm/barrier.h index d705be47a1ad..85eb7ef44a18 100644 --- a/arch/arm/include/asm/barrier.h +++ b/arch/arm/include/asm/barrier.h @@ -106,5 +106,24 @@ do { \ #define smp_mb__before_atomic() smp_mb() #define smp_mb__after_atomic() smp_mb() +#ifdef CONFIG_CPU_SPECTRE +static inline unsigned long array_index_mask_nospec(unsigned long idx, + unsigned long sz) +{ + unsigned long mask; + + asm volatile( + "cmp %1, %2\n" + " sbc %0, %1, %1\n" + CSDB + : "=r" (mask) + : "r" (idx), "Ir" (sz) + : "cc"); + + return mask; +} +#define array_index_mask_nospec array_index_mask_nospec +#endif + #endif /* !__ASSEMBLY__ */ #endif /* __ASM_BARRIER_H */ |