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authorMarc Zyngier <maz@kernel.org>2020-07-16 19:11:09 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2020-11-01 14:45:37 +0300
commit0ccd5c2c60e0eba3f9cf624fb6b4d28c4aa8c84a (patch)
tree842731b8d8ee4934e8b2f277e082701e8cec590f
parent4720b25e4ca38bfd05e4dbf541d5358accf9adf8 (diff)
downloadlinux-0ccd5c2c60e0eba3f9cf624fb6b4d28c4aa8c84a.tar.xz
arm64: Run ARCH_WORKAROUND_1 enabling code on all CPUs
commit 18fce56134c987e5b4eceddafdbe4b00c07e2ae1 upstream. Commit 73f381660959 ("arm64: Advertise mitigation of Spectre-v2, or lack thereof") changed the way we deal with ARCH_WORKAROUND_1, by moving most of the enabling code to the .matches() callback. This has the unfortunate effect that the workaround gets only enabled on the first affected CPU, and no other. In order to address this, forcefully call the .matches() callback from a .cpu_enable() callback, which brings us back to the original behaviour. Fixes: 73f381660959 ("arm64: Advertise mitigation of Spectre-v2, or lack thereof") Cc: <stable@vger.kernel.org> Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--arch/arm64/kernel/cpu_errata.c8
1 files changed, 8 insertions, 0 deletions
diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c
index 6e8a7eec667e..146ce55107cc 100644
--- a/arch/arm64/kernel/cpu_errata.c
+++ b/arch/arm64/kernel/cpu_errata.c
@@ -599,6 +599,12 @@ check_branch_predictor(const struct arm64_cpu_capabilities *entry, int scope)
return (need_wa > 0);
}
+static void
+cpu_enable_branch_predictor_hardening(const struct arm64_cpu_capabilities *cap)
+{
+ cap->matches(cap, SCOPE_LOCAL_CPU);
+}
+
static const __maybe_unused struct midr_range tx2_family_cpus[] = {
MIDR_ALL_VERSIONS(MIDR_BRCM_VULCAN),
MIDR_ALL_VERSIONS(MIDR_CAVIUM_THUNDERX2),
@@ -890,9 +896,11 @@ const struct arm64_cpu_capabilities arm64_errata[] = {
},
#endif
{
+ .desc = "Branch predictor hardening",
.capability = ARM64_HARDEN_BRANCH_PREDICTOR,
.type = ARM64_CPUCAP_LOCAL_CPU_ERRATUM,
.matches = check_branch_predictor,
+ .cpu_enable = cpu_enable_branch_predictor_hardening,
},
#ifdef CONFIG_HARDEN_EL2_VECTORS
{