diff options
Diffstat (limited to 'arch/arm64/kernel/cpu_errata.c')
| -rw-r--r-- | arch/arm64/kernel/cpu_errata.c | 236 |
1 files changed, 3 insertions, 233 deletions
diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c index 5eb9a9126dc4..4103391f51b5 100644 --- a/arch/arm64/kernel/cpu_errata.c +++ b/arch/arm64/kernel/cpu_errata.c @@ -106,145 +106,6 @@ cpu_enable_trap_ctr_access(const struct arm64_cpu_capabilities *cap) sysreg_clear_set(sctlr_el1, SCTLR_EL1_UCT, 0); } -atomic_t arm64_el2_vector_last_slot = ATOMIC_INIT(-1); - -#include <asm/mmu_context.h> -#include <asm/cacheflush.h> - -DEFINE_PER_CPU_READ_MOSTLY(struct bp_hardening_data, bp_hardening_data); - -#ifdef CONFIG_RANDOMIZE_BASE -static void __copy_hyp_vect_bpi(int slot, const char *hyp_vecs_start, - const char *hyp_vecs_end) -{ - void *dst = lm_alias(__bp_harden_hyp_vecs + slot * SZ_2K); - int i; - - for (i = 0; i < SZ_2K; i += 0x80) - memcpy(dst + i, hyp_vecs_start, hyp_vecs_end - hyp_vecs_start); - - __flush_icache_range((uintptr_t)dst, (uintptr_t)dst + SZ_2K); -} - -static void install_bp_hardening_cb(bp_hardening_cb_t fn) -{ - static DEFINE_RAW_SPINLOCK(bp_lock); - int cpu, slot = -1; - const char *hyp_vecs_start = __smccc_workaround_1_smc; - const char *hyp_vecs_end = __smccc_workaround_1_smc + - __SMCCC_WORKAROUND_1_SMC_SZ; - - /* - * detect_harden_bp_fw() passes NULL for the hyp_vecs start/end if - * we're a guest. Skip the hyp-vectors work. - */ - if (!is_hyp_mode_available()) { - __this_cpu_write(bp_hardening_data.fn, fn); - return; - } - - raw_spin_lock(&bp_lock); - for_each_possible_cpu(cpu) { - if (per_cpu(bp_hardening_data.fn, cpu) == fn) { - slot = per_cpu(bp_hardening_data.hyp_vectors_slot, cpu); - break; - } - } - - if (slot == -1) { - slot = atomic_inc_return(&arm64_el2_vector_last_slot); - BUG_ON(slot >= BP_HARDEN_EL2_SLOTS); - __copy_hyp_vect_bpi(slot, hyp_vecs_start, hyp_vecs_end); - } - - __this_cpu_write(bp_hardening_data.hyp_vectors_slot, slot); - __this_cpu_write(bp_hardening_data.fn, fn); - raw_spin_unlock(&bp_lock); -} -#else -static void install_bp_hardening_cb(bp_hardening_cb_t fn) -{ - __this_cpu_write(bp_hardening_data.fn, fn); -} -#endif /* CONFIG_RANDOMIZE_BASE */ - -#include <linux/arm-smccc.h> - -static void __maybe_unused call_smc_arch_workaround_1(void) -{ - arm_smccc_1_1_smc(ARM_SMCCC_ARCH_WORKAROUND_1, NULL); -} - -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 bool __nospectre_v2; -static int __init parse_nospectre_v2(char *str) -{ - __nospectre_v2 = true; - return 0; -} -early_param("nospectre_v2", parse_nospectre_v2); - -/* - * -1: No workaround - * 0: No workaround required - * 1: Workaround installed - */ -static int detect_harden_bp_fw(void) -{ - bp_hardening_cb_t cb; - struct arm_smccc_res res; - u32 midr = read_cpuid_id(); - - arm_smccc_1_1_invoke(ARM_SMCCC_ARCH_FEATURES_FUNC_ID, - ARM_SMCCC_ARCH_WORKAROUND_1, &res); - - switch ((int)res.a0) { - case 1: - /* Firmware says we're just fine */ - return 0; - case 0: - break; - default: - return -1; - } - - switch (arm_smccc_1_1_get_conduit()) { - case SMCCC_CONDUIT_HVC: - cb = call_hvc_arch_workaround_1; - break; - - case SMCCC_CONDUIT_SMC: - cb = call_smc_arch_workaround_1; - break; - - default: - return -1; - } - - 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(cb); - return 1; -} - DEFINE_PER_CPU_READ_MOSTLY(u64, arm64_ssbd_callback_required); int ssbd_state __read_mostly = ARM64_SSBD_KERNEL; @@ -508,83 +369,6 @@ cpu_enable_cache_maint_trap(const struct arm64_cpu_capabilities *__unused) .type = ARM64_CPUCAP_LOCAL_CPU_ERRATUM, \ CAP_MIDR_RANGE_LIST(midr_list) -/* Track overall mitigation state. We are only mitigated if all cores are ok */ -static bool __hardenbp_enab = true; -static bool __spectrev2_safe = true; - -int get_spectre_v2_workaround_state(void) -{ - if (__spectrev2_safe) - return ARM64_BP_HARDEN_NOT_REQUIRED; - - if (!__hardenbp_enab) - return ARM64_BP_HARDEN_UNKNOWN; - - return ARM64_BP_HARDEN_WA_NEEDED; -} - -/* - * List of CPUs that do not need any Spectre-v2 mitigation at all. - */ -static const struct midr_range spectre_v2_safe_list[] = { - MIDR_ALL_VERSIONS(MIDR_CORTEX_A35), - MIDR_ALL_VERSIONS(MIDR_CORTEX_A53), - MIDR_ALL_VERSIONS(MIDR_CORTEX_A55), - MIDR_ALL_VERSIONS(MIDR_BRAHMA_B53), - MIDR_ALL_VERSIONS(MIDR_HISI_TSV110), - MIDR_ALL_VERSIONS(MIDR_QCOM_KRYO_3XX_SILVER), - MIDR_ALL_VERSIONS(MIDR_QCOM_KRYO_4XX_SILVER), - { /* sentinel */ } -}; - -/* - * Track overall bp hardening for all heterogeneous cores in the machine. - * We are only considered "safe" if all booted cores are known safe. - */ -static bool __maybe_unused -check_branch_predictor(const struct arm64_cpu_capabilities *entry, int scope) -{ - int need_wa; - - WARN_ON(scope != SCOPE_LOCAL_CPU || preemptible()); - - /* If the CPU has CSV2 set, we're safe */ - if (cpuid_feature_extract_unsigned_field(read_cpuid(ID_AA64PFR0_EL1), - ID_AA64PFR0_CSV2_SHIFT)) - return false; - - /* Alternatively, we have a list of unaffected CPUs */ - if (is_midr_in_range_list(read_cpuid_id(), spectre_v2_safe_list)) - return false; - - /* Fallback to firmware detection */ - need_wa = detect_harden_bp_fw(); - if (!need_wa) - return false; - - __spectrev2_safe = false; - - /* forced off */ - if (__nospectre_v2 || cpu_mitigations_off()) { - pr_info_once("spectrev2 mitigation disabled by command line option\n"); - __hardenbp_enab = false; - return false; - } - - if (need_wa < 0) { - pr_warn_once("ARM_SMCCC_ARCH_WORKAROUND_1 missing from firmware\n"); - __hardenbp_enab = false; - } - - return (need_wa > 0); -} - -static void -cpu_enable_branch_predictor_hardening(const struct arm64_cpu_capabilities *cap) -{ - cap->matches(cap, SCOPE_LOCAL_CPU); -} - static const __maybe_unused struct midr_range tx2_family_cpus[] = { MIDR_ALL_VERSIONS(MIDR_BRCM_VULCAN), MIDR_ALL_VERSIONS(MIDR_CAVIUM_THUNDERX2), @@ -876,11 +660,11 @@ const struct arm64_cpu_capabilities arm64_errata[] = { }, #endif { - .desc = "Branch predictor hardening", + .desc = "Spectre-v2", .capability = ARM64_SPECTRE_V2, .type = ARM64_CPUCAP_LOCAL_CPU_ERRATUM, - .matches = check_branch_predictor, - .cpu_enable = cpu_enable_branch_predictor_hardening, + .matches = has_spectre_v2, + .cpu_enable = spectre_v2_enable_mitigation, }, #ifdef CONFIG_RANDOMIZE_BASE { @@ -949,20 +733,6 @@ const struct arm64_cpu_capabilities arm64_errata[] = { } }; -ssize_t cpu_show_spectre_v2(struct device *dev, struct device_attribute *attr, - char *buf) -{ - switch (get_spectre_v2_workaround_state()) { - case ARM64_BP_HARDEN_NOT_REQUIRED: - return sprintf(buf, "Not affected\n"); - case ARM64_BP_HARDEN_WA_NEEDED: - return sprintf(buf, "Mitigation: Branch predictor hardening\n"); - case ARM64_BP_HARDEN_UNKNOWN: - default: - return sprintf(buf, "Vulnerable\n"); - } -} - ssize_t cpu_show_spec_store_bypass(struct device *dev, struct device_attribute *attr, char *buf) { |