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authorJeremy Linton <jeremy.linton@arm.com>2019-04-15 16:21:25 -0500
committerWill Deacon <will.deacon@arm.com>2019-04-26 16:30:18 +0100
commit8c1e3d2bb44cbb998cb28ff9a18f105fee7f1eb3 (patch)
treea2e3e1fb0e924b7f3a89ba5da615181990ed4711 /arch/arm64/kernel/cpu_errata.c
parent517953c2c47f9c00a002f588ac856a5bc70cede3 (diff)
arm64: Always enable spectre-v2 vulnerability detection
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 <jeremy.linton@arm.com> Reviewed-by: Andre Przywara <andre.przywara@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Tested-by: Stefan Wahren <stefan.wahren@i2se.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
Diffstat (limited to 'arch/arm64/kernel/cpu_errata.c')
-rw-r--r--arch/arm64/kernel/cpu_errata.c15
1 files changed, 8 insertions, 7 deletions
diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c
index 60cf87c4deb7..a9c3ad4f7948 100644
--- a/arch/arm64/kernel/cpu_errata.c
+++ b/arch/arm64/kernel/cpu_errata.c
@@ -109,7 +109,6 @@ 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 <asm/mmu_context.h>
#include <asm/cacheflush.h>
@@ -270,11 +269,11 @@ 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 */
#ifdef CONFIG_ARM64_SSBD
DEFINE_PER_CPU_READ_MOSTLY(u64, arm64_ssbd_callback_required);
@@ -513,7 +512,6 @@ cpu_enable_cache_maint_trap(const struct arm64_cpu_capabilities *__unused)
.type = ARM64_CPUCAP_LOCAL_CPU_ERRATUM, \
CAP_MIDR_RANGE_LIST(midr_list)
-#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
@@ -731,13 +734,11 @@ 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",