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-rw-r--r--arch/arm64/Kconfig1
-rw-r--r--arch/arm64/include/asm/cpufeature.h4
-rw-r--r--arch/arm64/kernel/cpu_errata.c243
-rw-r--r--arch/arm64/kernel/cpufeature.c66
-rw-r--r--arch/powerpc/kernel/security.c6
-rw-r--r--arch/powerpc/kernel/setup_64.c2
-rw-r--r--arch/s390/kernel/nospec-branch.c3
-rw-r--r--arch/x86/kernel/cpu/bugs.c11
-rw-r--r--arch/x86/mm/pti.c4
9 files changed, 247 insertions, 93 deletions
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index d28f12e9c160..b5c6943225ce 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -90,6 +90,7 @@ config ARM64
select GENERIC_CLOCKEVENTS
select GENERIC_CLOCKEVENTS_BROADCAST
select GENERIC_CPU_AUTOPROBE
+ select GENERIC_CPU_VULNERABILITIES
select GENERIC_EARLY_IOREMAP
select GENERIC_IDLE_POLL_SETUP
select GENERIC_IRQ_MULTI_HANDLER
diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h
index a3f028f82def..f210bcf096f7 100644
--- a/arch/arm64/include/asm/cpufeature.h
+++ b/arch/arm64/include/asm/cpufeature.h
@@ -633,11 +633,7 @@ static inline int arm64_get_ssbd_state(void)
#endif
}
-#ifdef CONFIG_ARM64_SSBD
void arm64_set_ssbd_mitigation(bool state);
-#else
-static inline void arm64_set_ssbd_mitigation(bool state) {}
-#endif
extern int do_emulate_mrs(struct pt_regs *regs, u32 sys_reg, u32 rt);
diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c
index 9950bb0cbd52..1b9ce0fdd81d 100644
--- a/arch/arm64/kernel/cpu_errata.c
+++ b/arch/arm64/kernel/cpu_errata.c
@@ -19,6 +19,7 @@
#include <linux/arm-smccc.h>
#include <linux/psci.h>
#include <linux/types.h>
+#include <linux/cpu.h>
#include <asm/cpu.h>
#include <asm/cputype.h>
#include <asm/cpufeature.h>
@@ -109,7 +110,6 @@ 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>
@@ -131,9 +131,9 @@ static void __copy_hyp_vect_bpi(int slot, const char *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,
- const char *hyp_vecs_start,
- const char *hyp_vecs_end)
+static void install_bp_hardening_cb(bp_hardening_cb_t fn,
+ const char *hyp_vecs_start,
+ const char *hyp_vecs_end)
{
static DEFINE_RAW_SPINLOCK(bp_lock);
int cpu, slot = -1;
@@ -169,7 +169,7 @@ static void __install_bp_hardening_cb(bp_hardening_cb_t fn,
#define __smccc_workaround_1_smc_start NULL
#define __smccc_workaround_1_smc_end NULL
-static void __install_bp_hardening_cb(bp_hardening_cb_t fn,
+static void install_bp_hardening_cb(bp_hardening_cb_t fn,
const char *hyp_vecs_start,
const char *hyp_vecs_end)
{
@@ -177,23 +177,6 @@ static void __install_bp_hardening_cb(bp_hardening_cb_t fn,
}
#endif /* CONFIG_KVM_INDIRECT_VECTORS */
-static void install_bp_hardening_cb(const struct arm64_cpu_capabilities *entry,
- bp_hardening_cb_t fn,
- const char *hyp_vecs_start,
- const char *hyp_vecs_end)
-{
- u64 pfr0;
-
- if (!entry->matches(entry, SCOPE_LOCAL_CPU))
- return;
-
- pfr0 = read_cpuid(ID_AA64PFR0_EL1);
- if (cpuid_feature_extract_unsigned_field(pfr0, ID_AA64PFR0_CSV2_SHIFT))
- return;
-
- __install_bp_hardening_cb(fn, hyp_vecs_start, hyp_vecs_end);
-}
-
#include <uapi/linux/psci.h>
#include <linux/arm-smccc.h>
#include <linux/psci.h>
@@ -220,60 +203,83 @@ static void qcom_link_stack_sanitization(void)
: "=&r" (tmp));
}
-static void
-enable_smccc_arch_workaround_1(const struct arm64_cpu_capabilities *entry)
+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;
void *smccc_start, *smccc_end;
struct arm_smccc_res res;
u32 midr = read_cpuid_id();
- if (!entry->matches(entry, SCOPE_LOCAL_CPU))
- return;
-
if (psci_ops.smccc_version == SMCCC_VERSION_1_0)
- return;
+ return -1;
switch (psci_ops.conduit) {
case PSCI_CONDUIT_HVC:
arm_smccc_1_1_hvc(ARM_SMCCC_ARCH_FEATURES_FUNC_ID,
ARM_SMCCC_ARCH_WORKAROUND_1, &res);
- if ((int)res.a0 < 0)
- return;
- cb = call_hvc_arch_workaround_1;
- /* This is a guest, no need to patch KVM vectors */
- smccc_start = NULL;
- smccc_end = NULL;
+ switch ((int)res.a0) {
+ case 1:
+ /* Firmware says we're just fine */
+ return 0;
+ case 0:
+ cb = call_hvc_arch_workaround_1;
+ /* This is a guest, no need to patch KVM vectors */
+ smccc_start = NULL;
+ smccc_end = NULL;
+ break;
+ default:
+ return -1;
+ }
break;
case PSCI_CONDUIT_SMC:
arm_smccc_1_1_smc(ARM_SMCCC_ARCH_FEATURES_FUNC_ID,
ARM_SMCCC_ARCH_WORKAROUND_1, &res);
- if ((int)res.a0 < 0)
- return;
- cb = call_smc_arch_workaround_1;
- smccc_start = __smccc_workaround_1_smc_start;
- smccc_end = __smccc_workaround_1_smc_end;
+ switch ((int)res.a0) {
+ case 1:
+ /* Firmware says we're just fine */
+ return 0;
+ case 0:
+ cb = call_smc_arch_workaround_1;
+ smccc_start = __smccc_workaround_1_smc_start;
+ smccc_end = __smccc_workaround_1_smc_end;
+ break;
+ default:
+ return -1;
+ }
break;
default:
- return;
+ 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(entry, cb, smccc_start, smccc_end);
+ if (IS_ENABLED(CONFIG_HARDEN_BRANCH_PREDICTOR))
+ install_bp_hardening_cb(cb, smccc_start, smccc_end);
- return;
+ return 1;
}
-#endif /* CONFIG_HARDEN_BRANCH_PREDICTOR */
-#ifdef CONFIG_ARM64_SSBD
DEFINE_PER_CPU_READ_MOSTLY(u64, arm64_ssbd_callback_required);
int ssbd_state __read_mostly = ARM64_SSBD_KERNEL;
+static bool __ssb_safe = true;
static const struct ssbd_options {
const char *str;
@@ -343,6 +349,11 @@ void __init arm64_enable_wa2_handling(struct alt_instr *alt,
void arm64_set_ssbd_mitigation(bool state)
{
+ if (!IS_ENABLED(CONFIG_ARM64_SSBD)) {
+ pr_info_once("SSBD disabled by kernel configuration\n");
+ return;
+ }
+
if (this_cpu_has_cap(ARM64_SSBS)) {
if (state)
asm volatile(SET_PSTATE_SSBS(0));
@@ -372,16 +383,28 @@ static bool has_ssbd_mitigation(const struct arm64_cpu_capabilities *entry,
struct arm_smccc_res res;
bool required = true;
s32 val;
+ bool this_cpu_safe = false;
WARN_ON(scope != SCOPE_LOCAL_CPU || preemptible());
+ if (cpu_mitigations_off())
+ ssbd_state = ARM64_SSBD_FORCE_DISABLE;
+
+ /* delay setting __ssb_safe until we get a firmware response */
+ if (is_midr_in_range_list(read_cpuid_id(), entry->midr_range_list))
+ this_cpu_safe = true;
+
if (this_cpu_has_cap(ARM64_SSBS)) {
+ if (!this_cpu_safe)
+ __ssb_safe = false;
required = false;
goto out_printmsg;
}
if (psci_ops.smccc_version == SMCCC_VERSION_1_0) {
ssbd_state = ARM64_SSBD_UNKNOWN;
+ if (!this_cpu_safe)
+ __ssb_safe = false;
return false;
}
@@ -398,6 +421,8 @@ static bool has_ssbd_mitigation(const struct arm64_cpu_capabilities *entry,
default:
ssbd_state = ARM64_SSBD_UNKNOWN;
+ if (!this_cpu_safe)
+ __ssb_safe = false;
return false;
}
@@ -406,14 +431,18 @@ static bool has_ssbd_mitigation(const struct arm64_cpu_capabilities *entry,
switch (val) {
case SMCCC_RET_NOT_SUPPORTED:
ssbd_state = ARM64_SSBD_UNKNOWN;
+ if (!this_cpu_safe)
+ __ssb_safe = false;
return false;
+ /* machines with mixed mitigation requirements must not return this */
case SMCCC_RET_NOT_REQUIRED:
pr_info_once("%s mitigation not required\n", entry->desc);
ssbd_state = ARM64_SSBD_MITIGATED;
return false;
case SMCCC_RET_SUCCESS:
+ __ssb_safe = false;
required = true;
break;
@@ -423,6 +452,8 @@ static bool has_ssbd_mitigation(const struct arm64_cpu_capabilities *entry,
default:
WARN_ON(1);
+ if (!this_cpu_safe)
+ __ssb_safe = false;
return false;
}
@@ -462,7 +493,14 @@ out_printmsg:
return required;
}
-#endif /* CONFIG_ARM64_SSBD */
+
+/* known invulnerable cores */
+static const struct midr_range arm64_ssb_cpus[] = {
+ MIDR_ALL_VERSIONS(MIDR_CORTEX_A35),
+ MIDR_ALL_VERSIONS(MIDR_CORTEX_A53),
+ MIDR_ALL_VERSIONS(MIDR_CORTEX_A55),
+ {},
+};
static void __maybe_unused
cpu_enable_cache_maint_trap(const struct arm64_cpu_capabilities *__unused)
@@ -507,26 +545,67 @@ 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
+/* Track overall mitigation state. We are only mitigated if all cores are ok */
+static bool __hardenbp_enab = true;
+static bool __spectrev2_safe = true;
/*
- * List of CPUs where we need to issue a psci call to
- * harden the branch predictor.
+ * List of CPUs that do not need any Spectre-v2 mitigation at all.
*/
-static const struct midr_range arm64_bp_harden_smccc_cpus[] = {
- MIDR_ALL_VERSIONS(MIDR_CORTEX_A57),
- MIDR_ALL_VERSIONS(MIDR_CORTEX_A72),
- MIDR_ALL_VERSIONS(MIDR_CORTEX_A73),
- MIDR_ALL_VERSIONS(MIDR_CORTEX_A75),
- MIDR_ALL_VERSIONS(MIDR_BRCM_VULCAN),
- MIDR_ALL_VERSIONS(MIDR_CAVIUM_THUNDERX2),
- MIDR_ALL_VERSIONS(MIDR_QCOM_FALKOR_V1),
- MIDR_ALL_VERSIONS(MIDR_QCOM_FALKOR),
- MIDR_ALL_VERSIONS(MIDR_NVIDIA_DENVER),
- {},
+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),
+ { /* sentinel */ }
};
-#endif
+/*
+ * 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;
+
+ 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 || 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);
+}
#ifdef CONFIG_HARDEN_EL2_VECTORS
@@ -701,13 +780,11 @@ 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,
- .cpu_enable = enable_smccc_arch_workaround_1,
- ERRATA_MIDR_RANGE_LIST(arm64_bp_harden_smccc_cpus),
+ .type = ARM64_CPUCAP_LOCAL_CPU_ERRATUM,
+ .matches = check_branch_predictor,
},
-#endif
#ifdef CONFIG_HARDEN_EL2_VECTORS
{
.desc = "EL2 vector hardening",
@@ -715,14 +792,13 @@ const struct arm64_cpu_capabilities arm64_errata[] = {
ERRATA_MIDR_RANGE_LIST(arm64_harden_el2_vectors),
},
#endif
-#ifdef CONFIG_ARM64_SSBD
{
.desc = "Speculative Store Bypass Disable",
.capability = ARM64_SSBD,
.type = ARM64_CPUCAP_LOCAL_CPU_ERRATUM,
.matches = has_ssbd_mitigation,
+ .midr_range_list = arm64_ssb_cpus,
},
-#endif
#ifdef CONFIG_ARM64_ERRATUM_1188873
{
/* Cortex-A76 r0p0 to r2p0 */
@@ -742,3 +818,38 @@ const struct arm64_cpu_capabilities arm64_errata[] = {
{
}
};
+
+ssize_t cpu_show_spectre_v1(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ return sprintf(buf, "Mitigation: __user pointer sanitization\n");
+}
+
+ssize_t cpu_show_spectre_v2(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ if (__spectrev2_safe)
+ return sprintf(buf, "Not affected\n");
+
+ if (__hardenbp_enab)
+ return sprintf(buf, "Mitigation: Branch predictor hardening\n");
+
+ return sprintf(buf, "Vulnerable\n");
+}
+
+ssize_t cpu_show_spec_store_bypass(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ if (__ssb_safe)
+ return sprintf(buf, "Not affected\n");
+
+ switch (ssbd_state) {
+ case ARM64_SSBD_KERNEL:
+ case ARM64_SSBD_FORCE_ENABLE:
+ if (IS_ENABLED(CONFIG_ARM64_SSBD))
+ return sprintf(buf,
+ "Mitigation: Speculative Store Bypass disabled via prctl\n");
+ }
+
+ return sprintf(buf, "Vulnerable\n");
+}
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index d856c55445a2..2b807f129e60 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -25,6 +25,7 @@
#include <linux/stop_machine.h>
#include <linux/types.h>
#include <linux/mm.h>
+#include <linux/cpu.h>
#include <asm/cpu.h>
#include <asm/cpufeature.h>
#include <asm/cpu_ops.h>
@@ -956,7 +957,7 @@ has_useable_cnp(const struct arm64_cpu_capabilities *entry, int scope)
return has_cpuid_feature(entry, scope);
}
-#ifdef CONFIG_UNMAP_KERNEL_AT_EL0
+static bool __meltdown_safe = true;
static int __kpti_forced; /* 0: not forced, >0: forced on, <0: forced off */
static bool unmap_kernel_at_el0(const struct arm64_cpu_capabilities *entry,
@@ -975,7 +976,17 @@ static bool unmap_kernel_at_el0(const struct arm64_cpu_capabilities *entry,
MIDR_ALL_VERSIONS(MIDR_HISI_TSV110),
{ /* sentinel */ }
};
- char const *str = "command line option";
+ char const *str = "kpti command line option";
+ bool meltdown_safe;
+
+ meltdown_safe = is_midr_in_range_list(read_cpuid_id(), kpti_safe_list);
+
+ /* Defer to CPU feature registers */
+ if (has_cpuid_feature(entry, scope))
+ meltdown_safe = true;
+
+ if (!meltdown_safe)
+ __meltdown_safe = false;
/*
* For reasons that aren't entirely clear, enabling KPTI on Cavium
@@ -987,6 +998,24 @@ static bool unmap_kernel_at_el0(const struct arm64_cpu_capabilities *entry,
__kpti_forced = -1;
}
+ /* Useful for KASLR robustness */
+ if (IS_ENABLED(CONFIG_RANDOMIZE_BASE) && kaslr_offset() > 0) {
+ if (!__kpti_forced) {
+ str = "KASLR";
+ __kpti_forced = 1;
+ }
+ }
+
+ if (cpu_mitigations_off() && !__kpti_forced) {
+ str = "mitigations=off";
+ __kpti_forced = -1;
+ }
+
+ if (!IS_ENABLED(CONFIG_UNMAP_KERNEL_AT_EL0)) {
+ pr_info_once("kernel page table isolation disabled by kernel configuration\n");
+ return false;
+ }
+
/* Forced? */
if (__kpti_forced) {
pr_info_once("kernel page table isolation forced %s by %s\n",
@@ -994,18 +1023,10 @@ static bool unmap_kernel_at_el0(const struct arm64_cpu_capabilities *entry,
return __kpti_forced > 0;
}
- /* Useful for KASLR robustness */
- if (IS_ENABLED(CONFIG_RANDOMIZE_BASE))
- return kaslr_offset() > 0;
-
- /* Don't force KPTI for CPUs that are not vulnerable */
- if (is_midr_in_range_list(read_cpuid_id(), kpti_safe_list))
- return false;
-
- /* Defer to CPU feature registers */
- return !has_cpuid_feature(entry, scope);
+ return !meltdown_safe;
}
+#ifdef CONFIG_UNMAP_KERNEL_AT_EL0
static void
kpti_install_ng_mappings(const struct arm64_cpu_capabilities *__unused)
{
@@ -1035,6 +1056,12 @@ kpti_install_ng_mappings(const struct arm64_cpu_capabilities *__unused)
return;
}
+#else
+static void
+kpti_install_ng_mappings(const struct arm64_cpu_capabilities *__unused)
+{
+}
+#endif /* CONFIG_UNMAP_KERNEL_AT_EL0 */
static int __init parse_kpti(char *str)
{
@@ -1048,7 +1075,6 @@ static int __init parse_kpti(char *str)
return 0;
}
early_param("kpti", parse_kpti);
-#endif /* CONFIG_UNMAP_KERNEL_AT_EL0 */
#ifdef CONFIG_ARM64_HW_AFDBM
static inline void __cpu_enable_hw_dbm(void)
@@ -1315,7 +1341,6 @@ static const struct arm64_cpu_capabilities arm64_features[] = {
.field_pos = ID_AA64PFR0_EL0_SHIFT,
.min_field_value = ID_AA64PFR0_EL0_32BIT_64BIT,
},
-#ifdef CONFIG_UNMAP_KERNEL_AT_EL0
{
.desc = "Kernel page table isolation (KPTI)",
.capability = ARM64_UNMAP_KERNEL_AT_EL0,
@@ -1331,7 +1356,6 @@ static const struct arm64_cpu_capabilities arm64_features[] = {
.matches = unmap_kernel_at_el0,
.cpu_enable = kpti_install_ng_mappings,
},
-#endif
{
/* FP/SIMD is not implemented */
.capability = ARM64_HAS_NO_FPSIMD,
@@ -2156,3 +2180,15 @@ static int __init enable_mrs_emulation(void)
}
core_initcall(enable_mrs_emulation);
+
+ssize_t cpu_show_meltdown(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ if (__meltdown_safe)
+ return sprintf(buf, "Not affected\n");
+
+ if (arm64_kernel_unmapped_at_el0())
+ return sprintf(buf, "Mitigation: PTI\n");
+
+ return sprintf(buf, "Vulnerable\n");
+}
diff --git a/arch/powerpc/kernel/security.c b/arch/powerpc/kernel/security.c
index b33bafb8fcea..70568ccbd9fd 100644
--- a/arch/powerpc/kernel/security.c
+++ b/arch/powerpc/kernel/security.c
@@ -57,7 +57,7 @@ void setup_barrier_nospec(void)
enable = security_ftr_enabled(SEC_FTR_FAVOUR_SECURITY) &&
security_ftr_enabled(SEC_FTR_BNDS_CHK_SPEC_BAR);
- if (!no_nospec)
+ if (!no_nospec && !cpu_mitigations_off())
enable_barrier_nospec(enable);
}
@@ -116,7 +116,7 @@ static int __init handle_nospectre_v2(char *p)
early_param("nospectre_v2", handle_nospectre_v2);
void setup_spectre_v2(void)
{
- if (no_spectrev2)
+ if (no_spectrev2 || cpu_mitigations_off())
do_btb_flush_fixups();
else
btb_flush_enabled = true;
@@ -300,7 +300,7 @@ void setup_stf_barrier(void)
stf_enabled_flush_types = type;
- if (!no_stf_barrier)
+ if (!no_stf_barrier && !cpu_mitigations_off())
stf_barrier_enable(enable);
}
diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
index ba404dd9ce1d..4f49e1a3594c 100644
--- a/arch/powerpc/kernel/setup_64.c
+++ b/arch/powerpc/kernel/setup_64.c
@@ -932,7 +932,7 @@ void setup_rfi_flush(enum l1d_flush_type types, bool enable)
enabled_flush_types = types;
- if (!no_rfi_flush)
+ if (!no_rfi_flush && !cpu_mitigations_off())
rfi_flush_enable(enable);
}
diff --git a/arch/s390/kernel/nospec-branch.c b/arch/s390/kernel/nospec-branch.c
index bdddaae96559..649135cbedd5 100644
--- a/arch/s390/kernel/nospec-branch.c
+++ b/arch/s390/kernel/nospec-branch.c
@@ -1,6 +1,7 @@
// SPDX-License-Identifier: GPL-2.0
#include <linux/module.h>
#include <linux/device.h>
+#include <linux/cpu.h>
#include <asm/nospec-branch.h>
static int __init nobp_setup_early(char *str)
@@ -58,7 +59,7 @@ early_param("nospectre_v2", nospectre_v2_setup_early);
void __init nospec_auto_detect(void)
{
- if (test_facility(156)) {
+ if (test_facility(156) || cpu_mitigations_off()) {
/*
* The machine supports etokens.
* Disable expolines and disable nobp.
diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index 2da82eff0eb4..8043a21f36be 100644
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -440,7 +440,8 @@ static enum spectre_v2_mitigation_cmd __init spectre_v2_parse_cmdline(void)
char arg[20];
int ret, i;
- if (cmdline_find_option_bool(boot_command_line, "nospectre_v2"))
+ if (cmdline_find_option_bool(boot_command_line, "nospectre_v2") ||
+ cpu_mitigations_off())
return SPECTRE_V2_CMD_NONE;
ret = cmdline_find_option(boot_command_line, "spectre_v2", arg, sizeof(arg));
@@ -672,7 +673,8 @@ static enum ssb_mitigation_cmd __init ssb_parse_cmdline(void)
char arg[20];
int ret, i;
- if (cmdline_find_option_bool(boot_command_line, "nospec_store_bypass_disable")) {
+ if (cmdline_find_option_bool(boot_command_line, "nospec_store_bypass_disable") ||
+ cpu_mitigations_off()) {
return SPEC_STORE_BYPASS_CMD_NONE;
} else {
ret = cmdline_find_option(boot_command_line, "spec_store_bypass_disable",
@@ -1008,6 +1010,11 @@ static void __init l1tf_select_mitigation(void)
if (!boot_cpu_has_bug(X86_BUG_L1TF))
return;
+ if (cpu_mitigations_off())
+ l1tf_mitigation = L1TF_MITIGATION_OFF;
+ else if (cpu_mitigations_auto_nosmt())
+ l1tf_mitigation = L1TF_MITIGATION_FLUSH_NOSMT;
+
override_cache_bits(&boot_cpu_data);
switch (l1tf_mitigation) {
diff --git a/arch/x86/mm/pti.c b/arch/x86/mm/pti.c
index 139b28a01ce4..d0255d64edce 100644
--- a/arch/x86/mm/pti.c
+++ b/arch/x86/mm/pti.c
@@ -35,6 +35,7 @@
#include <linux/spinlock.h>
#include <linux/mm.h>
#include <linux/uaccess.h>
+#include <linux/cpu.h>
#include <asm/cpufeature.h>
#include <asm/hypervisor.h>
@@ -115,7 +116,8 @@ void __init pti_check_boottime_disable(void)
}
}
- if (cmdline_find_option_bool(boot_command_line, "nopti")) {
+ if (cmdline_find_option_bool(boot_command_line, "nopti") ||
+ cpu_mitigations_off()) {
pti_mode = PTI_FORCE_OFF;
pti_print_if_insecure("disabled on command line.");
return;
generated by cgit v1.2.3 (git 2.39.0) at 2024-12-23 17:50:49 +0300