From 59cbf79eecc18301a3cedd6a33946028ecbecf6e Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Wed, 3 Jan 2018 16:38:35 +0000 Subject: [PATCH] arm64: KVM: Use per-CPU vector when BP hardening is enabled Commit 6840bdd73d07 upstream. Now that we have per-CPU vectors, let's plug then in the KVM/arm64 code. Signed-off-by: Marc Zyngier Signed-off-by: Will Deacon Signed-off-by: Catalin Marinas Signed-off-by: Ard Biesheuvel Signed-off-by: Greg Kroah-Hartman (cherry picked from commit aab3306701f10c5dc35d8da74431cde6249baf0b) CVE-2017-5753 CVE-2017-5715 CVE-2017-5754 Signed-off-by: Paolo Pisati Acked-by: Brad Figg Acked-by: Kleber Sacilotto de Souza Signed-off-by: Khalid Elmously --- arch/arm/include/asm/kvm_mmu.h | 10 +++++++++ arch/arm64/include/asm/kvm_mmu.h | 38 ++++++++++++++++++++++++++++++++ arch/arm64/kvm/hyp/switch.c | 2 +- virt/kvm/arm/arm.c | 8 ++++++- 4 files changed, 56 insertions(+), 2 deletions(-) diff --git a/arch/arm/include/asm/kvm_mmu.h b/arch/arm/include/asm/kvm_mmu.h index fa6f2174276b..eb46fc81a440 100644 --- a/arch/arm/include/asm/kvm_mmu.h +++ b/arch/arm/include/asm/kvm_mmu.h @@ -221,6 +221,16 @@ static inline unsigned int kvm_get_vmid_bits(void) return 8; } +static inline void *kvm_get_hyp_vector(void) +{ + return kvm_ksym_ref(__kvm_hyp_vector); +} + +static inline int kvm_map_vectors(void) +{ + return 0; +} + #endif /* !__ASSEMBLY__ */ #endif /* __ARM_KVM_MMU_H__ */ diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h index 672c8684d5c2..2d6d4bd9de52 100644 --- a/arch/arm64/include/asm/kvm_mmu.h +++ b/arch/arm64/include/asm/kvm_mmu.h @@ -309,5 +309,43 @@ static inline unsigned int kvm_get_vmid_bits(void) return (cpuid_feature_extract_unsigned_field(reg, ID_AA64MMFR1_VMIDBITS_SHIFT) == 2) ? 16 : 8; } +#ifdef CONFIG_HARDEN_BRANCH_PREDICTOR +#include + +static inline void *kvm_get_hyp_vector(void) +{ + struct bp_hardening_data *data = arm64_get_bp_hardening_data(); + void *vect = kvm_ksym_ref(__kvm_hyp_vector); + + if (data->fn) { + vect = __bp_harden_hyp_vecs_start + + data->hyp_vectors_slot * SZ_2K; + + if (!has_vhe()) + vect = lm_alias(vect); + } + + return vect; +} + +static inline int kvm_map_vectors(void) +{ + return create_hyp_mappings(kvm_ksym_ref(__bp_harden_hyp_vecs_start), + kvm_ksym_ref(__bp_harden_hyp_vecs_end), + PAGE_HYP_EXEC); +} + +#else +static inline void *kvm_get_hyp_vector(void) +{ + return kvm_ksym_ref(__kvm_hyp_vector); +} + +static inline int kvm_map_vectors(void) +{ + return 0; +} +#endif + #endif /* __ASSEMBLY__ */ #endif /* __ARM64_KVM_MMU_H__ */ diff --git a/arch/arm64/kvm/hyp/switch.c b/arch/arm64/kvm/hyp/switch.c index 945e79c641c4..9b2a76d783eb 100644 --- a/arch/arm64/kvm/hyp/switch.c +++ b/arch/arm64/kvm/hyp/switch.c @@ -51,7 +51,7 @@ static void __hyp_text __activate_traps_vhe(void) val &= ~CPACR_EL1_FPEN; write_sysreg(val, cpacr_el1); - write_sysreg(__kvm_hyp_vector, vbar_el1); + write_sysreg(kvm_get_hyp_vector(), vbar_el1); } static void __hyp_text __activate_traps_nvhe(void) diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c index a39a1e161e63..4de94f8da84e 100644 --- a/virt/kvm/arm/arm.c +++ b/virt/kvm/arm/arm.c @@ -1136,7 +1136,7 @@ static void cpu_init_hyp_mode(void *dummy) pgd_ptr = kvm_mmu_get_httbr(); stack_page = __this_cpu_read(kvm_arm_hyp_stack_page); hyp_stack_ptr = stack_page + PAGE_SIZE; - vector_ptr = (unsigned long)kvm_ksym_ref(__kvm_hyp_vector); + vector_ptr = (unsigned long)kvm_get_hyp_vector(); __cpu_init_hyp_mode(pgd_ptr, hyp_stack_ptr, vector_ptr); __cpu_init_stage2(); @@ -1390,6 +1390,12 @@ static int init_hyp_mode(void) goto out_err; } + err = kvm_map_vectors(); + if (err) { + kvm_err("Cannot map vectors\n"); + goto out_err; + } + /* * Map the Hyp stack pages */ -- 2.39.2