[tip:x86/urgent] x86/microcode: Ensure that module is only loaded on supported Intel CPUs

From: tip-bot for Srivatsa S. Bhat
Date: Tue May 08 2012 - 00:28:57 EST


Commit-ID: 7164b3f5e5461b58baa82e82544ca5af71af287b
Gitweb: http://git.kernel.org/tip/7164b3f5e5461b58baa82e82544ca5af71af287b
Author: Srivatsa S. Bhat <srivatsa.bhat@xxxxxxxxxxxxxxxxxx>
AuthorDate: Mon, 16 Apr 2012 14:12:00 +0530
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Mon, 7 May 2012 14:37:14 +0200

x86/microcode: Ensure that module is only loaded on supported Intel CPUs

Exit early when there's no support for a particular CPU family.

Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@xxxxxxxxxxxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: Andreas Herrmann <andreas.herrmann3@xxxxxxx>
Cc: Kay Sievers <kay.sievers@xxxxxxxx>
Cc: Dave Jones <davej@xxxxxxxxxx>
Cc: tigran@xxxxxxxxxxxxxxxxxxxx
Cc: Borislav Petkov <borislav.petkov@xxxxxxx>
Link: http://lkml.kernel.org/r/4F8BDB58.6070007@xxxxxxxxxxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
arch/x86/kernel/microcode_intel.c | 14 ++++++++------
1 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/arch/x86/kernel/microcode_intel.c b/arch/x86/kernel/microcode_intel.c
index 3ca42d0..0327e2b 100644
--- a/arch/x86/kernel/microcode_intel.c
+++ b/arch/x86/kernel/microcode_intel.c
@@ -147,12 +147,6 @@ static int collect_cpu_info(int cpu_num, struct cpu_signature *csig)

memset(csig, 0, sizeof(*csig));

- if (c->x86_vendor != X86_VENDOR_INTEL || c->x86 < 6 ||
- cpu_has(c, X86_FEATURE_IA64)) {
- pr_err("CPU%d not a capable Intel processor\n", cpu_num);
- return -1;
- }
-
csig->sig = cpuid_eax(0x00000001);

if ((c->x86_model >= 5) || (c->x86 > 6)) {
@@ -463,6 +457,14 @@ static struct microcode_ops microcode_intel_ops = {

struct microcode_ops * __init init_intel_microcode(void)
{
+ struct cpuinfo_x86 *c = &cpu_data(0);
+
+ if (c->x86_vendor != X86_VENDOR_INTEL || c->x86 < 6 ||
+ cpu_has(c, X86_FEATURE_IA64)) {
+ pr_err("Intel CPU family 0x%x not supported\n", c->x86);
+ return NULL;
+ }
+
return &microcode_intel_ops;
}

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