From 9d1bb39cdd9629d1a6127bd085d3ecc7009789e0 Mon Sep 17 00:00:00 2001 From: Jeremy Linton Date: Tue, 8 Oct 2019 17:39:26 +0200 Subject: [PATCH] arm64: Always enable spectre-v2 vulnerability detection [ Upstream commit 8c1e3d2bb44cbb998cb28ff9a18f105fee7f1eb3 ] Ensure we are always able to detect whether or not the CPU is affected by Spectre-v2, so that we can later advertise this to userspace. Signed-off-by: Jeremy Linton Reviewed-by: Andre Przywara Reviewed-by: Catalin Marinas Tested-by: Stefan Wahren Signed-off-by: Will Deacon Signed-off-by: Ard Biesheuvel Signed-off-by: Greg Kroah-Hartman --- arch/arm64/kernel/cpu_errata.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-) diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c index ffb1b8ff7d82..96b0319dd0d6 100644 --- a/arch/arm64/kernel/cpu_errata.c +++ b/arch/arm64/kernel/cpu_errata.c @@ -87,7 +87,6 @@ cpu_enable_trap_ctr_access(const struct arm64_cpu_capabilities *__unused) atomic_t arm64_el2_vector_last_slot = ATOMIC_INIT(-1); -#ifdef CONFIG_HARDEN_BRANCH_PREDICTOR #include #include @@ -225,11 +224,11 @@ static int detect_harden_bp_fw(void) ((midr & MIDR_CPU_MODEL_MASK) == MIDR_QCOM_FALKOR_V1)) cb = qcom_link_stack_sanitization; - install_bp_hardening_cb(cb, smccc_start, smccc_end); + if (IS_ENABLED(CONFIG_HARDEN_BRANCH_PREDICTOR)) + install_bp_hardening_cb(cb, smccc_start, smccc_end); return 1; } -#endif /* CONFIG_HARDEN_BRANCH_PREDICTOR */ DEFINE_PER_CPU_READ_MOSTLY(u64, arm64_ssbd_callback_required); @@ -513,7 +512,6 @@ multi_entry_cap_cpu_enable(const struct arm64_cpu_capabilities *entry) caps->cpu_enable(caps); } -#ifdef CONFIG_HARDEN_BRANCH_PREDICTOR /* * List of CPUs that do not need any Spectre-v2 mitigation at all. */ @@ -545,6 +543,12 @@ check_branch_predictor(const struct arm64_cpu_capabilities *entry, int scope) if (!need_wa) return false; + if (!IS_ENABLED(CONFIG_HARDEN_BRANCH_PREDICTOR)) { + pr_warn_once("spectrev2 mitigation disabled by kernel configuration\n"); + __hardenbp_enab = false; + return false; + } + /* forced off */ if (__nospectre_v2) { pr_info_once("spectrev2 mitigation disabled by command line option\n"); @@ -556,7 +560,6 @@ check_branch_predictor(const struct arm64_cpu_capabilities *entry, int scope) return (need_wa > 0); } -#endif #ifdef CONFIG_HARDEN_EL2_VECTORS @@ -715,13 +718,11 @@ const struct arm64_cpu_capabilities arm64_errata[] = { ERRATA_MIDR_ALL_VERSIONS(MIDR_CORTEX_A73), }, #endif -#ifdef CONFIG_HARDEN_BRANCH_PREDICTOR { .capability = ARM64_HARDEN_BRANCH_PREDICTOR, .type = ARM64_CPUCAP_LOCAL_CPU_ERRATUM, .matches = check_branch_predictor, }, -#endif #ifdef CONFIG_HARDEN_EL2_VECTORS { .desc = "EL2 vector hardening", -- GitLab