[PATCH v4 5/6] arm: Invalidate icache on prefetch abort outside of user mapping on Cortex-A15
From: Marc Zyngier <hidden>
Date: 2018-02-01 11:07:37
Subsystem:
arm port, the rest · Maintainers:
Russell King, Linus Torvalds
In order to prevent aliasing attacks on the branch predictor, invalidate the icache on Cortex-A15, which has the side effect of invalidating the BTB. This requires ACTLR[0] to be set to 1 (secure operation). Signed-off-by: Marc Zyngier <redacted> --- arch/arm/include/asm/cp15.h | 1 + arch/arm/mm/fault.c | 4 ++++ 2 files changed, 5 insertions(+)
diff --git a/arch/arm/include/asm/cp15.h b/arch/arm/include/asm/cp15.h
index 9e900ae855aa..07e27f212dc7 100644
--- a/arch/arm/include/asm/cp15.h
+++ b/arch/arm/include/asm/cp15.h@@ -66,6 +66,7 @@ #define write_sysreg(v, ...) __write_sysreg(v, __VA_ARGS__) #define BPIALL __ACCESS_CP15(c7, 0, c5, 6) +#define ICIALLU __ACCESS_CP15(c7, 0, c5, 0) extern unsigned long cr_alignment; /* defined in entry-armv.S */
diff --git a/arch/arm/mm/fault.c b/arch/arm/mm/fault.c
index 2f945c994e25..1b05b4b3e761 100644
--- a/arch/arm/mm/fault.c
+++ b/arch/arm/mm/fault.c@@ -410,6 +410,10 @@ do_pabt_page_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs) case ARM_CPU_PART_CORTEX_A17: write_sysreg(0, BPIALL); break; + + case ARM_CPU_PART_CORTEX_A15: + write_sysreg(0, ICIALLU); + break; } } #endif
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2.14.2