[PATCH 3.16 164/328] x86/spectre: Add missing family 6 check to microcode check

Ben Hutchings
2018-12-09T22:25:06Z

From: Andi Kleen <ak@linux.intel.com>

commit 1ab534e85c93945f7862378d8c8adcf408205b19 upstream.

The check for Spectre microcodes does not check for family 6, only the
model numbers.

Add a family 6 check to avoid ambiguity with other families.

Fixes: a5b296636453 ("x86/cpufeature: Blacklist SPEC_CTRL/PRED_CMD on early Spectre v2 microcodes")
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: x86@kernel.org
Cc: linux-kernel@vger.kernel.org
Link: https://lkml.kernel.org/r/20180824170351.34874-2-andi@firstfloor.org
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
arch/x86/kernel/cpu/intel.c | 3 +++
1 file changed, 3 insertions(+)

--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -75,6 +75,9 @@ static bool bad_spectre_microcode(struct
if (cpu_has(c, X86_FEATURE_HYPERVISOR))
return false;

+ if (c->x86 != 6)
+ return false;
+
for (i = 0; i < ARRAY_SIZE(spectre_bad_microcodes); i++) {
if (c->x86_model == spectre_bad_microcodes[i].model &&
c->x86_mask == spectre_bad_microcodes[i].stepping)