The sysfs patches need to display machine vulnerability
status regardless of kernel config. Prepare for that
by breaking out the vulnerability/mitigation detection
code from the logic which implements the mitigation.

Signed-off-by: Jeremy Linton <jeremy.lin...@arm.com>
Reviewed-by: Andre Przywara <andre.przyw...@arm.com>
Reviewed-by: Catalin Marinas <catalin.mari...@arm.com>
Tested-by: Stefan Wahren <stefan.wah...@i2se.com>
---
 arch/arm64/kernel/cpu_errata.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c
index e5c4c5d84a4e..74c4a66500c4 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 +543,11 @@ 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 
configuration\n");
+               return false;
+       }
+
        /* forced off */
        if (__nospectre_v2) {
                pr_info_once("spectrev2 mitigation disabled by command line 
option\n");
@@ -556,7 +559,6 @@ check_branch_predictor(const struct arm64_cpu_capabilities 
*entry, int scope)
 
        return (need_wa > 0);
 }
-#endif
 
 #ifdef CONFIG_HARDEN_EL2_VECTORS
 
@@ -731,13 +733,11 @@ 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",
-- 
2.20.1

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