diff options
| author | Russell King <rmk+kernel@armlinux.org.uk> | 2018-05-11 15:06:58 +0100 |
|---|---|---|
| committer | Moyster <oysterized@gmail.com> | 2019-05-03 18:15:52 +0200 |
| commit | 8df7a210bdcb08abfc8fa35e5c8811a28671f9e8 (patch) | |
| tree | b2cc1b299155fcfbe6996043a6d10d4696513111 /arch/arm | |
| parent | c31a09121e04a757cf4b20efda49187cdd137a6f (diff) | |
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.
Change-Id: I66d16e24b4725df0bf70f53c91a34be9f26fba98
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>
Diffstat (limited to 'arch/arm')
| -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 aaa76b4da..c01e88893 100644 --- a/arch/arm/include/asm/barrier.h +++ b/arch/arm/include/asm/barrier.h @@ -92,5 +92,24 @@ do { \ #define set_mb(var, value) do { var = value; smp_mb(); } while (0) +#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 */ |