diff options
Diffstat (limited to 'arch/arm64/kernel/proton-pack.c')
| -rw-r--r-- | arch/arm64/kernel/proton-pack.c | 90 |
1 files changed, 37 insertions, 53 deletions
diff --git a/arch/arm64/kernel/proton-pack.c b/arch/arm64/kernel/proton-pack.c index c18eb7d41274..902e4084c477 100644 --- a/arch/arm64/kernel/proton-pack.c +++ b/arch/arm64/kernel/proton-pack.c @@ -1,6 +1,6 @@ // SPDX-License-Identifier: GPL-2.0-only /* - * Handle detection, reporting and mitigation of Spectre v1, v2 and v4, as + * Handle detection, reporting and mitigation of Spectre v1, v2, v3a and v4, as * detailed at: * * https://developer.arm.com/support/arm-security-updates/speculative-processor-vulnerability @@ -24,8 +24,10 @@ #include <linux/prctl.h> #include <linux/sched/task_stack.h> +#include <asm/insn.h> #include <asm/spectre.h> #include <asm/traps.h> +#include <asm/virt.h> /* * We try to ensure that the mitigation state can never change as the result of @@ -118,6 +120,7 @@ static enum mitigation_state spectre_v2_get_cpu_hw_mitigation_state(void) MIDR_ALL_VERSIONS(MIDR_CORTEX_A55), MIDR_ALL_VERSIONS(MIDR_BRAHMA_B53), MIDR_ALL_VERSIONS(MIDR_HISI_TSV110), + MIDR_ALL_VERSIONS(MIDR_QCOM_KRYO_2XX_SILVER), MIDR_ALL_VERSIONS(MIDR_QCOM_KRYO_3XX_SILVER), MIDR_ALL_VERSIONS(MIDR_QCOM_KRYO_4XX_SILVER), { /* sentinel */ } @@ -169,72 +172,26 @@ bool has_spectre_v2(const struct arm64_cpu_capabilities *entry, int scope) return true; } -DEFINE_PER_CPU_READ_MOSTLY(struct bp_hardening_data, bp_hardening_data); - enum mitigation_state arm64_get_spectre_v2_state(void) { return spectre_v2_state; } -#ifdef CONFIG_KVM -#include <asm/cacheflush.h> -#include <asm/kvm_asm.h> - -atomic_t arm64_el2_vector_last_slot = ATOMIC_INIT(-1); - -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); -} +DEFINE_PER_CPU_READ_MOSTLY(struct bp_hardening_data, bp_hardening_data); 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; + __this_cpu_write(bp_hardening_data.fn, fn); /* * Vinz Clortho takes the hyp_vecs start/end "keys" at * the door when we're a guest. Skip the hyp-vectors work. */ - if (!is_hyp_mode_available()) { - __this_cpu_write(bp_hardening_data.fn, fn); + if (!is_hyp_mode_available()) 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); + __this_cpu_write(bp_hardening_data.slot, HYP_VECTOR_SPECTRE_DIRECT); } -#endif /* CONFIG_KVM */ static void call_smc_arch_workaround_1(void) { @@ -316,6 +273,33 @@ void spectre_v2_enable_mitigation(const struct arm64_cpu_capabilities *__unused) } /* + * Spectre-v3a. + * + * Phew, there's not an awful lot to do here! We just instruct EL2 to use + * an indirect trampoline for the hyp vectors so that guests can't read + * VBAR_EL2 to defeat randomisation of the hypervisor VA layout. + */ +bool has_spectre_v3a(const struct arm64_cpu_capabilities *entry, int scope) +{ + static const struct midr_range spectre_v3a_unsafe_list[] = { + MIDR_ALL_VERSIONS(MIDR_CORTEX_A57), + MIDR_ALL_VERSIONS(MIDR_CORTEX_A72), + {}, + }; + + WARN_ON(scope != SCOPE_LOCAL_CPU || preemptible()); + return is_midr_in_range_list(read_cpuid_id(), spectre_v3a_unsafe_list); +} + +void spectre_v3a_enable_mitigation(const struct arm64_cpu_capabilities *__unused) +{ + struct bp_hardening_data *data = this_cpu_ptr(&bp_hardening_data); + + if (this_cpu_has_cap(ARM64_SPECTRE_V3A)) + data->slot += HYP_VECTOR_INDIRECT; +} + +/* * Spectre v4. * * If you thought Spectre v2 was nasty, wait until you see this mess. A CPU is @@ -537,12 +521,12 @@ static enum mitigation_state spectre_v4_enable_hw_mitigation(void) if (spectre_v4_mitigations_off()) { sysreg_clear_set(sctlr_el1, 0, SCTLR_ELx_DSSBS); - asm volatile(SET_PSTATE_SSBS(1)); + set_pstate_ssbs(1); return SPECTRE_VULNERABLE; } /* SCTLR_EL1.DSSBS was initialised to 0 during boot */ - asm volatile(SET_PSTATE_SSBS(0)); + set_pstate_ssbs(0); return SPECTRE_MITIGATED; } |