From 688f1e4b6d8f792c44bec3a448664fd9e8949964 Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Tue, 15 Sep 2020 23:00:31 +0100 Subject: [PATCH] arm64: Rename ARM64_HARDEN_BRANCH_PREDICTOR to ARM64_SPECTRE_V2 For better or worse, the world knows about "Spectre" and not about "Branch predictor hardening". Rename ARM64_HARDEN_BRANCH_PREDICTOR to ARM64_SPECTRE_V2 as part of moving all of the Spectre mitigations into their own little corner. Signed-off-by: Will Deacon --- arch/arm64/include/asm/cpucaps.h | 2 +- arch/arm64/include/asm/kvm_mmu.h | 27 +++++++++++++-------------- arch/arm64/include/asm/mmu.h | 2 +- arch/arm64/kernel/cpu_errata.c | 2 +- 4 files changed, 16 insertions(+), 17 deletions(-) diff --git a/arch/arm64/include/asm/cpucaps.h b/arch/arm64/include/asm/cpucaps.h index 07b643a70710..348bfcf6c818 100644 --- a/arch/arm64/include/asm/cpucaps.h +++ b/arch/arm64/include/asm/cpucaps.h @@ -31,7 +31,7 @@ #define ARM64_HAS_DCPOP 21 #define ARM64_SVE 22 #define ARM64_UNMAP_KERNEL_AT_EL0 23 -#define ARM64_HARDEN_BRANCH_PREDICTOR 24 +#define ARM64_SPECTRE_V2 24 #define ARM64_HAS_RAS_EXTN 25 #define ARM64_WORKAROUND_843419 26 #define ARM64_HAS_CACHE_IDC 27 diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h index dfd176b0642e..873e12430ac7 100644 --- a/arch/arm64/include/asm/kvm_mmu.h +++ b/arch/arm64/include/asm/kvm_mmu.h @@ -435,14 +435,13 @@ static inline int kvm_write_guest_lock(struct kvm *kvm, gpa_t gpa, * EL2 vectors can be mapped and rerouted in a number of ways, * depending on the kernel configuration and CPU present: * - * - If the CPU has the ARM64_HARDEN_BRANCH_PREDICTOR cap, the - * hardening sequence is placed in one of the vector slots, which is - * executed before jumping to the real vectors. + * - If the CPU is affected by Spectre-v2, the hardening sequence is + * placed in one of the vector slots, which is executed before jumping + * to the real vectors. * - * - If the CPU has both the ARM64_HARDEN_EL2_VECTORS cap and the - * ARM64_HARDEN_BRANCH_PREDICTOR cap, the slot containing the - * hardening sequence is mapped next to the idmap page, and executed - * before jumping to the real vectors. + * - If the CPU also has the ARM64_HARDEN_EL2_VECTORS cap, the slot + * containing the hardening sequence is mapped next to the idmap page, + * and executed before jumping to the real vectors. * * - If the CPU only has the ARM64_HARDEN_EL2_VECTORS cap, then an * empty slot is selected, mapped next to the idmap page, and @@ -464,7 +463,7 @@ static inline void *kvm_get_hyp_vector(void) void *vect = kern_hyp_va(kvm_ksym_ref(__kvm_hyp_vector)); int slot = -1; - if (cpus_have_const_cap(ARM64_HARDEN_BRANCH_PREDICTOR) && data->fn) { + if (cpus_have_const_cap(ARM64_SPECTRE_V2) && data->fn) { vect = kern_hyp_va(kvm_ksym_ref(__bp_harden_hyp_vecs)); slot = data->hyp_vectors_slot; } @@ -485,15 +484,15 @@ static inline void *kvm_get_hyp_vector(void) static inline int kvm_map_vectors(void) { /* - * HBP = ARM64_HARDEN_BRANCH_PREDICTOR + * SV2 = ARM64_SPECTRE_V2 * HEL2 = ARM64_HARDEN_EL2_VECTORS * - * !HBP + !HEL2 -> use direct vectors - * HBP + !HEL2 -> use hardened vectors in place - * !HBP + HEL2 -> allocate one vector slot and use exec mapping - * HBP + HEL2 -> use hardened vertors and use exec mapping + * !SV2 + !HEL2 -> use direct vectors + * SV2 + !HEL2 -> use hardened vectors in place + * !SV2 + HEL2 -> allocate one vector slot and use exec mapping + * SV2 + HEL2 -> use hardened vertors and use exec mapping */ - if (cpus_have_const_cap(ARM64_HARDEN_BRANCH_PREDICTOR)) { + if (cpus_have_const_cap(ARM64_SPECTRE_V2)) { __kvm_bp_vect_base = kvm_ksym_ref(__bp_harden_hyp_vecs); __kvm_bp_vect_base = kern_hyp_va(__kvm_bp_vect_base); } diff --git a/arch/arm64/include/asm/mmu.h b/arch/arm64/include/asm/mmu.h index f5e3efeb5b97..cbff2d42c1d8 100644 --- a/arch/arm64/include/asm/mmu.h +++ b/arch/arm64/include/asm/mmu.h @@ -56,7 +56,7 @@ static inline void arm64_apply_bp_hardening(void) { struct bp_hardening_data *d; - if (!cpus_have_const_cap(ARM64_HARDEN_BRANCH_PREDICTOR)) + if (!cpus_have_const_cap(ARM64_SPECTRE_V2)) return; d = arm64_get_bp_hardening_data(); diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c index a72ca57f5630..b275f2d5e7a3 100644 --- a/arch/arm64/kernel/cpu_errata.c +++ b/arch/arm64/kernel/cpu_errata.c @@ -877,7 +877,7 @@ const struct arm64_cpu_capabilities arm64_errata[] = { #endif { .desc = "Branch predictor hardening", - .capability = ARM64_HARDEN_BRANCH_PREDICTOR, + .capability = ARM64_SPECTRE_V2, .type = ARM64_CPUCAP_LOCAL_CPU_ERRATUM, .matches = check_branch_predictor, .cpu_enable = cpu_enable_branch_predictor_hardening, -- 2.25.1