From mboxrd@z Thu Jan 1 00:00:00 1970 From: marc.zyngier@arm.com (Marc Zyngier) Date: Wed, 28 Mar 2018 13:52:48 +0100 Subject: [PATCH 79/85] arm64: Enable ARM64_HARDEN_EL2_VECTORS on Cortex-A57 and A72 In-Reply-To: <20180328125254.31380-1-marc.zyngier@arm.com> References: <20180328125254.31380-1-marc.zyngier@arm.com> Message-ID: <20180328125254.31380-80-marc.zyngier@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Cortex-A57 and A72 are vulnerable to the so-called "variant 3a" of Meltdown, where an attacker can speculatively obtain the value of a privileged system register. By enabling ARM64_HARDEN_EL2_VECTORS on these CPUs, obtaining VBAR_EL2 is not disclosing the hypervisor mappings anymore. Acked-by: Catalin Marinas Signed-off-by: Marc Zyngier --- arch/arm64/kernel/cpu_errata.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c index 8cf6b60a085a..aacdc118c4c9 100644 --- a/arch/arm64/kernel/cpu_errata.c +++ b/arch/arm64/kernel/cpu_errata.c @@ -424,6 +424,18 @@ const struct arm64_cpu_capabilities arm64_errata[] = { MIDR_ALL_VERSIONS(MIDR_CAVIUM_THUNDERX2), .enable = enable_smccc_arch_workaround_1, }, +#endif +#ifdef CONFIG_HARDEN_EL2_VECTORS + { + .desc = "Cortex-A57 EL2 vector hardening", + .capability = ARM64_HARDEN_EL2_VECTORS, + MIDR_ALL_VERSIONS(MIDR_CORTEX_A57), + }, + { + .desc = "Cortex-A72 EL2 vector hardening", + .capability = ARM64_HARDEN_EL2_VECTORS, + MIDR_ALL_VERSIONS(MIDR_CORTEX_A72), + }, #endif { } -- 2.14.2