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| author | Russell King <rmk+kernel@armlinux.org.uk> | 2018-11-07 11:43:55 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-11-23 08:20:39 +0100 |
| commit | 8a4ae2876f6c03e3def6fb1d438cc5f01932cdc1 (patch) | |
| tree | 62470f82a3056457cbd025a44c73f2a04351360f /arch | |
| parent | abdeed7e61be1b3a92c7dc02762b36f49d14d7fa (diff) | |
| download | linux-stable-8a4ae2876f6c03e3def6fb1d438cc5f01932cdc1.tar.gz linux-stable-8a4ae2876f6c03e3def6fb1d438cc5f01932cdc1.tar.bz2 linux-stable-8a4ae2876f6c03e3def6fb1d438cc5f01932cdc1.zip | |
ARM: spectre-v1: add array_index_mask_nospec() implementation
Commit 1d4238c56f9816ce0f9c8dbe42d7f2ad81cb6613 upstream.
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>
Signed-off-by: David A. Long <dave.long@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch')
| -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 6f00dac6ad8e..513e03d138ea 100644 --- a/arch/arm/include/asm/barrier.h +++ b/arch/arm/include/asm/barrier.h @@ -75,6 +75,25 @@ extern void arm_heavy_mb(void); #define __smp_rmb() __smp_mb() #define __smp_wmb() dmb(ishst) +#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 + #include <asm-generic/barrier.h> #endif /* !__ASSEMBLY__ */ |