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

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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 <will.deacon@arm.com>
This commit is contained in:
Will Deacon 2019-04-30 16:58:56 +01:00
parent 61ae1321f0
commit eb337cdfcd
1 changed files with 7 additions and 5 deletions
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12
arch/arm64/kernel/cpu_errata.c
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@ -386,15 +386,17 @@ static bool has_ssbd_mitigation(const struct arm64_cpu_capabilities *entry,
WARN_ON(scope != SCOPE_LOCAL_CPU || preemptible()); WARN_ON(scope != SCOPE_LOCAL_CPU || preemptible());
if (this_cpu_has_cap(ARM64_SSBS)) {
required = false;
goto out_printmsg;
}
/* delay setting __ssb_safe until we get a firmware response */ /* delay setting __ssb_safe until we get a firmware response */
if (is_midr_in_range_list(read_cpuid_id(), entry->midr_range_list)) if (is_midr_in_range_list(read_cpuid_id(), entry->midr_range_list))
this_cpu_safe = true; 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) { if (psci_ops.smccc_version == SMCCC_VERSION_1_0) {
ssbd_state = ARM64_SSBD_UNKNOWN; ssbd_state = ARM64_SSBD_UNKNOWN;
if (!this_cpu_safe) if (!this_cpu_safe)