[tip:x86/urgent] x86/spectre: Add missing family 6 check to microcode check

[tip-bot for Andi Kleen]

Commit-ID:  1ab534e85c93945f7862378d8c8adcf408205b19
Gitweb:     https://git.kernel.org/tip/1ab534e85c93945f7862378d8c8adcf408205b19
Author:     Andi Kleen <ak@xxxxxxxxxxxxxxx>
AuthorDate: Fri, 24 Aug 2018 10:03:51 -0700
Committer:  Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitDate: Mon, 27 Aug 2018 10:29:14 +0200

x86/spectre: Add missing family 6 check to microcode check

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@xxxxxxxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: x86@xxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Cc: stable@xxxxxxxxxxxxxxx
Link: https://lkml.kernel.org/r/20180824170351.34874-2-andi@xxxxxxxxxxxxxx

---
 arch/x86/kernel/cpu/intel.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
index 401e8c133108..fc3c07fe7df5 100644
--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -150,6 +150,9 @@ static bool bad_spectre_microcode(struct cpuinfo_x86 *c)
 	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_stepping == spectre_bad_microcodes[i].stepping)