arm64: ssbs: Don't treat CPUs with SSBS as unaffected by SSB

SSBS provides a relatively cheap mitigation for SSB, but it is still a mitigation and its presence does not indicate that the CPU is unaffected by the vulnerability. Tweak the mitigation logic so that we report the correct string in sysfs. Signed-off-by: Will Deacon <[email protected]>
berg · May 1, 2019 · eb337cd · eb337cd
1 parent 61ae132
commit eb337cd
Showing 1 changed file with 6 additions and 4 deletions.
diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c
@@ -386,15 +386,17 @@ static bool has_ssbd_mitigation(const struct arm64_cpu_capabilities *entry,
 
 	WARN_ON(scope != SCOPE_LOCAL_CPU || preemptible());
 
+	/* 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;
 	}
 
-	/* 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 (psci_ops.smccc_version == SMCCC_VERSION_1_0) {
 		ssbd_state = ARM64_SSBD_UNKNOWN;
 		if (!this_cpu_safe)