From: Marc Zyngier maz@kernel.org
commit 39533e12063be7f55e3d6ae21ffe067799d542a4 upstream.
Commit 606f8e7b27bf ("arm64: capabilities: Use linear array for detection and verification") changed the way we deal with per-CPU errata by only calling the .matches() callback until one CPU is found to be affected. At this point, .matches() stop being called, and .cpu_enable() will be called on all CPUs.
This breaks the ARCH_WORKAROUND_2 handling, as only a single CPU will be mitigated.
In order to address this, forcefully call the .matches() callback from a .cpu_enable() callback, which brings us back to the original behaviour.
Fixes: 606f8e7b27bf ("arm64: capabilities: Use linear array for detection and verification") 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
--- arch/arm64/kernel/cpu_errata.c | 7 +++++++ 1 file changed, 7 insertions(+)
--- a/arch/arm64/kernel/cpu_errata.c +++ b/arch/arm64/kernel/cpu_errata.c @@ -492,6 +492,12 @@ out_printmsg: return required; }
+static void cpu_enable_ssbd_mitigation(const struct arm64_cpu_capabilities *cap) +{ + if (ssbd_state != ARM64_SSBD_FORCE_DISABLE) + cap->matches(cap, SCOPE_LOCAL_CPU); +} + /* known invulnerable cores */ static const struct midr_range arm64_ssb_cpus[] = { MIDR_ALL_VERSIONS(MIDR_CORTEX_A35), @@ -918,6 +924,7 @@ const struct arm64_cpu_capabilities arm6 .capability = ARM64_SSBD, .type = ARM64_CPUCAP_LOCAL_CPU_ERRATUM, .matches = has_ssbd_mitigation, + .cpu_enable = cpu_enable_ssbd_mitigation, .midr_range_list = arm64_ssb_cpus, }, #ifdef CONFIG_ARM64_ERRATUM_1418040