From mboxrd@z Thu Jan 1 00:00:00 1970 From: marc.zyngier@arm.com (Marc Zyngier) Date: Mon, 8 Jan 2018 18:55:32 +0000 Subject: [PATCH v2 5/6] arm: Invalidate icache on prefetch abort outside of user mapping on Cortex-A15 In-Reply-To: <20180108185533.9698-1-marc.zyngier@arm.com> References: <20180108185533.9698-1-marc.zyngier@arm.com> Message-ID: <20180108185533.9698-6-marc.zyngier@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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 --- 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 ff272ffcf741..bda37ce63fc7 100644 --- a/arch/arm/mm/fault.c +++ b/arch/arm/mm/fault.c @@ -417,6 +417,10 @@ 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; } } -- 2.14.2