From 4bc352ffb39e4eec253e70f8c076f2f48a6c1926 Mon Sep 17 00:00:00 2001 From: Shanker Donthineni Date: Tue, 10 Apr 2018 11:36:42 +0100 Subject: arm64: KVM: Use SMCCC_ARCH_WORKAROUND_1 for Falkor BP hardening The function SMCCC_ARCH_WORKAROUND_1 was introduced as part of SMC V1.1 Calling Convention to mitigate CVE-2017-5715. This patch uses the standard call SMCCC_ARCH_WORKAROUND_1 for Falkor chips instead of Silicon provider service ID 0xC2001700. Cc: # 4.14+ Signed-off-by: Shanker Donthineni [maz: reworked errata framework integration] Signed-off-by: Marc Zyngier Signed-off-by: Will Deacon --- arch/arm64/include/asm/cpucaps.h | 13 ++++---- arch/arm64/include/asm/kvm_asm.h | 2 -- arch/arm64/kernel/bpi.S | 8 ----- arch/arm64/kernel/cpu_errata.c | 66 ++++++++++++---------------------------- arch/arm64/kvm/hyp/entry.S | 12 -------- arch/arm64/kvm/hyp/switch.c | 10 ------ 6 files changed, 25 insertions(+), 86 deletions(-) (limited to 'arch') diff --git a/arch/arm64/include/asm/cpucaps.h b/arch/arm64/include/asm/cpucaps.h index a311880feb0f..bc51b72fafd4 100644 --- a/arch/arm64/include/asm/cpucaps.h +++ b/arch/arm64/include/asm/cpucaps.h @@ -43,13 +43,12 @@ #define ARM64_SVE 22 #define ARM64_UNMAP_KERNEL_AT_EL0 23 #define ARM64_HARDEN_BRANCH_PREDICTOR 24 -#define ARM64_HARDEN_BP_POST_GUEST_EXIT 25 -#define ARM64_HAS_RAS_EXTN 26 -#define ARM64_WORKAROUND_843419 27 -#define ARM64_HAS_CACHE_IDC 28 -#define ARM64_HAS_CACHE_DIC 29 -#define ARM64_HW_DBM 30 +#define ARM64_HAS_RAS_EXTN 25 +#define ARM64_WORKAROUND_843419 26 +#define ARM64_HAS_CACHE_IDC 27 +#define ARM64_HAS_CACHE_DIC 28 +#define ARM64_HW_DBM 29 -#define ARM64_NCAPS 31 +#define ARM64_NCAPS 30 #endif /* __ASM_CPUCAPS_H */ diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h index d53d40704416..f6648a3e4152 100644 --- a/arch/arm64/include/asm/kvm_asm.h +++ b/arch/arm64/include/asm/kvm_asm.h @@ -71,8 +71,6 @@ extern u32 __kvm_get_mdcr_el2(void); extern u32 __init_stage2_translation(void); -extern void __qcom_hyp_sanitize_btac_predictors(void); - #else /* __ASSEMBLY__ */ .macro get_host_ctxt reg, tmp diff --git a/arch/arm64/kernel/bpi.S b/arch/arm64/kernel/bpi.S index bb0b67722e86..9404f6aecda7 100644 --- a/arch/arm64/kernel/bpi.S +++ b/arch/arm64/kernel/bpi.S @@ -74,14 +74,6 @@ ENTRY(__bp_harden_hyp_vecs_end) .popsection -ENTRY(__qcom_hyp_sanitize_link_stack_start) - stp x29, x30, [sp, #-16]! - .rept 16 - bl . + 4 - .endr - ldp x29, x30, [sp], #16 -ENTRY(__qcom_hyp_sanitize_link_stack_end) - .macro smccc_workaround_1 inst sub sp, sp, #(8 * 4) stp x2, x3, [sp, #(8 * 0)] diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c index 9262ec57f5ab..103c53fb0b4d 100644 --- a/arch/arm64/kernel/cpu_errata.c +++ b/arch/arm64/kernel/cpu_errata.c @@ -87,8 +87,6 @@ atomic_t arm64_el2_vector_last_slot = ATOMIC_INIT(-1); DEFINE_PER_CPU_READ_MOSTLY(struct bp_hardening_data, bp_hardening_data); #ifdef CONFIG_KVM -extern char __qcom_hyp_sanitize_link_stack_start[]; -extern char __qcom_hyp_sanitize_link_stack_end[]; extern char __smccc_workaround_1_smc_start[]; extern char __smccc_workaround_1_smc_end[]; extern char __smccc_workaround_1_hvc_start[]; @@ -132,8 +130,6 @@ static void __install_bp_hardening_cb(bp_hardening_cb_t fn, spin_unlock(&bp_lock); } #else -#define __qcom_hyp_sanitize_link_stack_start NULL -#define __qcom_hyp_sanitize_link_stack_end NULL #define __smccc_workaround_1_smc_start NULL #define __smccc_workaround_1_smc_end NULL #define __smccc_workaround_1_hvc_start NULL @@ -178,12 +174,25 @@ static void call_hvc_arch_workaround_1(void) arm_smccc_1_1_hvc(ARM_SMCCC_ARCH_WORKAROUND_1, NULL); } +static void qcom_link_stack_sanitization(void) +{ + u64 tmp; + + asm volatile("mov %0, x30 \n" + ".rept 16 \n" + "bl . + 4 \n" + ".endr \n" + "mov x30, %0 \n" + : "=&r" (tmp)); +} + static void enable_smccc_arch_workaround_1(const struct arm64_cpu_capabilities *entry) { bp_hardening_cb_t cb; void *smccc_start, *smccc_end; struct arm_smccc_res res; + u32 midr = read_cpuid_id(); if (!entry->matches(entry, SCOPE_LOCAL_CPU)) return; @@ -216,30 +225,14 @@ enable_smccc_arch_workaround_1(const struct arm64_cpu_capabilities *entry) return; } + if (((midr & MIDR_CPU_MODEL_MASK) == MIDR_QCOM_FALKOR) || + ((midr & MIDR_CPU_MODEL_MASK) == MIDR_QCOM_FALKOR_V1)) + cb = qcom_link_stack_sanitization; + install_bp_hardening_cb(entry, cb, smccc_start, smccc_end); return; } - -static void qcom_link_stack_sanitization(void) -{ - u64 tmp; - - asm volatile("mov %0, x30 \n" - ".rept 16 \n" - "bl . + 4 \n" - ".endr \n" - "mov x30, %0 \n" - : "=&r" (tmp)); -} - -static void -qcom_enable_link_stack_sanitization(const struct arm64_cpu_capabilities *entry) -{ - install_bp_hardening_cb(entry, qcom_link_stack_sanitization, - __qcom_hyp_sanitize_link_stack_start, - __qcom_hyp_sanitize_link_stack_end); -} #endif /* CONFIG_HARDEN_BRANCH_PREDICTOR */ #define CAP_MIDR_RANGE(model, v_min, r_min, v_max, r_max) \ @@ -324,27 +317,11 @@ static const struct midr_range arm64_bp_harden_smccc_cpus[] = { MIDR_ALL_VERSIONS(MIDR_CORTEX_A75), MIDR_ALL_VERSIONS(MIDR_BRCM_VULCAN), MIDR_ALL_VERSIONS(MIDR_CAVIUM_THUNDERX2), - {}, -}; - -static const struct midr_range qcom_bp_harden_cpus[] = { MIDR_ALL_VERSIONS(MIDR_QCOM_FALKOR_V1), MIDR_ALL_VERSIONS(MIDR_QCOM_FALKOR), {}, }; -static const struct arm64_cpu_capabilities arm64_bp_harden_list[] = { - { - CAP_MIDR_RANGE_LIST(arm64_bp_harden_smccc_cpus), - .cpu_enable = enable_smccc_arch_workaround_1, - }, - { - CAP_MIDR_RANGE_LIST(qcom_bp_harden_cpus), - .cpu_enable = qcom_enable_link_stack_sanitization, - }, - {}, -}; - #endif #ifndef ERRATA_MIDR_ALL_VERSIONS @@ -495,13 +472,8 @@ const struct arm64_cpu_capabilities arm64_errata[] = { { .capability = ARM64_HARDEN_BRANCH_PREDICTOR, .type = ARM64_CPUCAP_LOCAL_CPU_ERRATUM, - .matches = multi_entry_cap_matches, - .cpu_enable = multi_entry_cap_cpu_enable, - .match_list = arm64_bp_harden_list, - }, - { - .capability = ARM64_HARDEN_BP_POST_GUEST_EXIT, - ERRATA_MIDR_RANGE_LIST(qcom_bp_harden_cpus), + .cpu_enable = enable_smccc_arch_workaround_1, + ERRATA_MIDR_RANGE_LIST(arm64_bp_harden_smccc_cpus), }, #endif #ifdef CONFIG_HARDEN_EL2_VECTORS diff --git a/arch/arm64/kvm/hyp/entry.S b/arch/arm64/kvm/hyp/entry.S index 1f458f7c3b44..e41a161d313a 100644 --- a/arch/arm64/kvm/hyp/entry.S +++ b/arch/arm64/kvm/hyp/entry.S @@ -209,15 +209,3 @@ alternative_endif eret ENDPROC(__fpsimd_guest_restore) - -ENTRY(__qcom_hyp_sanitize_btac_predictors) - /** - * Call SMC64 with Silicon provider serviceID 23<<8 (0xc2001700) - * 0xC2000000-0xC200FFFF: assigned to SiP Service Calls - * b15-b0: contains SiP functionID - */ - movz x0, #0x1700 - movk x0, #0xc200, lsl #16 - smc #0 - ret -ENDPROC(__qcom_hyp_sanitize_btac_predictors) diff --git a/arch/arm64/kvm/hyp/switch.c b/arch/arm64/kvm/hyp/switch.c index 07b572173265..d9645236e474 100644 --- a/arch/arm64/kvm/hyp/switch.c +++ b/arch/arm64/kvm/hyp/switch.c @@ -472,16 +472,6 @@ int __hyp_text __kvm_vcpu_run_nvhe(struct kvm_vcpu *vcpu) /* And we're baaack! */ } while (fixup_guest_exit(vcpu, &exit_code)); - if (cpus_have_const_cap(ARM64_HARDEN_BP_POST_GUEST_EXIT)) { - u32 midr = read_cpuid_id(); - - /* Apply BTAC predictors mitigation to all Falkor chips */ - if (((midr & MIDR_CPU_MODEL_MASK) == MIDR_QCOM_FALKOR) || - ((midr & MIDR_CPU_MODEL_MASK) == MIDR_QCOM_FALKOR_V1)) { - __qcom_hyp_sanitize_btac_predictors(); - } - } - fp_enabled = __fpsimd_enabled_nvhe(); __sysreg_save_state_nvhe(guest_ctxt); -- cgit v1.2.1