From: David Brazdil <dbrazdil@xxxxxxxxxx> The HARDEN_EL2_VECTORS config maps vectors at a fixed location on cores which are susceptible to Spector variant 3a (A57, A72) to prevent defeating hyp layout randomization by leaking the value of VBAR_EL2. Since this feature is only applicable when EL2 layout randomization is enabled, unify both behind the same RANDOMIZE_BASE Kconfig. Majority of code remains conditional on a capability selected for the affected cores. Signed-off-by: David Brazdil <dbrazdil@xxxxxxxxxx> Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx> Link: https://lore.kernel.org/r/20200721094445.82184-3-dbrazdil@xxxxxxxxxx --- arch/arm64/Kconfig | 16 ---------------- arch/arm64/include/asm/mmu.h | 6 ++---- arch/arm64/kernel/cpu_errata.c | 4 ++-- arch/arm64/kvm/Kconfig | 2 +- 4 files changed, 5 insertions(+), 23 deletions(-) diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 31380da53689..152deef3277e 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -1182,22 +1182,6 @@ config HARDEN_BRANCH_PREDICTOR If unsure, say Y. -config HARDEN_EL2_VECTORS - bool "Harden EL2 vector mapping against system register leak" if EXPERT - default y - help - Speculation attacks against some high-performance processors can - be used to leak privileged information such as the vector base - register, resulting in a potential defeat of the EL2 layout - randomization. - - This config option will map the vectors to a fixed location, - independent of the EL2 code mapping, so that revealing VBAR_EL2 - to an attacker does not give away any extra information. This - only gets enabled on affected CPUs. - - If unsure, say Y. - config ARM64_SSBD bool "Speculative Store Bypass Disable" if EXPERT default y diff --git a/arch/arm64/include/asm/mmu.h b/arch/arm64/include/asm/mmu.h index 68140fdd89d6..bd12011eb560 100644 --- a/arch/arm64/include/asm/mmu.h +++ b/arch/arm64/include/asm/mmu.h @@ -42,12 +42,10 @@ struct bp_hardening_data { bp_hardening_cb_t fn; }; -#if (defined(CONFIG_HARDEN_BRANCH_PREDICTOR) || \ - defined(CONFIG_HARDEN_EL2_VECTORS)) - +#ifdef CONFIG_KVM_INDIRECT_VECTORS extern char __bp_harden_hyp_vecs[]; extern atomic_t arm64_el2_vector_last_slot; -#endif /* CONFIG_HARDEN_BRANCH_PREDICTOR || CONFIG_HARDEN_EL2_VECTORS */ +#endif #ifdef CONFIG_HARDEN_BRANCH_PREDICTOR DECLARE_PER_CPU_READ_MOSTLY(struct bp_hardening_data, bp_hardening_data); diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c index ad06d6802d2e..a524142e55d0 100644 --- a/arch/arm64/kernel/cpu_errata.c +++ b/arch/arm64/kernel/cpu_errata.c @@ -635,7 +635,7 @@ has_neoverse_n1_erratum_1542419(const struct arm64_cpu_capabilities *entry, return is_midr_in_range(midr, &range) && has_dic; } -#if defined(CONFIG_HARDEN_EL2_VECTORS) +#ifdef CONFIG_RANDOMIZE_BASE static const struct midr_range ca57_a72[] = { MIDR_ALL_VERSIONS(MIDR_CORTEX_A57), @@ -880,7 +880,7 @@ const struct arm64_cpu_capabilities arm64_errata[] = { .type = ARM64_CPUCAP_LOCAL_CPU_ERRATUM, .matches = check_branch_predictor, }, -#ifdef CONFIG_HARDEN_EL2_VECTORS +#ifdef CONFIG_RANDOMIZE_BASE { .desc = "EL2 vector hardening", .capability = ARM64_HARDEN_EL2_VECTORS, diff --git a/arch/arm64/kvm/Kconfig b/arch/arm64/kvm/Kconfig index 13489aff4440..318c8f2df245 100644 --- a/arch/arm64/kvm/Kconfig +++ b/arch/arm64/kvm/Kconfig @@ -58,7 +58,7 @@ config KVM_ARM_PMU virtual machines. config KVM_INDIRECT_VECTORS - def_bool HARDEN_BRANCH_PREDICTOR || HARDEN_EL2_VECTORS + def_bool HARDEN_BRANCH_PREDICTOR || RANDOMIZE_BASE endif # KVM -- 2.27.0 _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
