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@linux.vnet.ibm.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Andreas Herrmann <andreas.herrmann3@amd.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Dave Jones <davej@redhat.com>
Cc: tigran@aivazian.fsnet.co.uk
Cc: Borislav Petkov <borislav.petkov@amd.com>
Link: http://lkml.kernel.org/r/4F8BDB58.6070007@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/arch/x86/kernel/microcode_intel.c b/arch/x86/kernel/microcode_intel.c
index 3ca42d0e43a201f736a4ee3f0c5d5e9899933429..0327e2b3c40869a0a767d8885572904a7f1cb2d4 100644 (file)
--- 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;
 }