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authorJeremy Linton <jeremy.linton@arm.com>2019-10-08 17:39:23 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-10-11 18:21:33 +0200
commitc131623b1e9d94c11e2db4635c4572a85fd8b3ce (patch)
treea3c8b42aec738dbedad20cfe685a676686c0f5a5 /arch
parent47a11f2eafcc08f7515d141b49f0f889c203b480 (diff)
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arm64: Always enable ssb vulnerability detection
[ Upstream commit d42281b6e49510f078ace15a8ea10f71e6262581 ] Ensure we are always able to detect whether or not the CPU is affected by SSB, 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> [will: Use IS_ENABLED instead of #ifdef] Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch')
-rw-r--r--arch/arm64/include/asm/cpufeature.h4
-rw-r--r--arch/arm64/kernel/cpu_errata.c9
2 files changed, 5 insertions, 8 deletions
diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h
index 510f687d269a..dda6e5056810 100644
--- a/arch/arm64/include/asm/cpufeature.h
+++ b/arch/arm64/include/asm/cpufeature.h
@@ -525,11 +525,7 @@ 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
#endif /* __ASSEMBLY__ */
diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c
index 3758ba538a43..10571a378f4c 100644
--- a/arch/arm64/kernel/cpu_errata.c
+++ b/arch/arm64/kernel/cpu_errata.c
@@ -239,7 +239,6 @@ enable_smccc_arch_workaround_1(const struct arm64_cpu_capabilities *entry)
}
#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;
@@ -312,6 +311,11 @@ 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));
@@ -431,7 +435,6 @@ out_printmsg:
return required;
}
-#endif /* CONFIG_ARM64_SSBD */
#ifdef CONFIG_ARM64_ERRATUM_1463225
DEFINE_PER_CPU(int, __in_cortex_a76_erratum_1463225_wa);
@@ -710,14 +713,12 @@ 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,
},
-#endif
#ifdef CONFIG_ARM64_ERRATUM_1463225
{
.desc = "ARM erratum 1463225",