[ 07/75] x86, microcode: Ensure that module is only loaded on supported AMD CPUs

Greg KH
2012-05-04T20:44:44Z

From: Andreas Herrmann <andreas.herrmann3@amd.com>

commit 283c1f2558ef4a4411fe908364b15b73b6ab44cf upstream.

Exit early when there's no support for a particular CPU family. Also,
fixup the "no support for this CPU vendor" to be issued only when the
driver is attempted to be loaded on an unsupported vendor.

Cc: Tigran Aivazian <tigran@aivazian.fsnet.co.uk>
Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: http://lkml.kernel.org/r/20120411163849.GE4794@alberich.amd.com
[Boris: add a commit msg because Andreas is lazy]
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
arch/x86/kernel/microcode_amd.c | 12 +++++++-----
arch/x86/kernel/microcode_core.c | 6 +++---
2 files changed, 10 insertions(+), 8 deletions(-)

--- a/arch/x86/kernel/microcode_amd.c
+++ b/arch/x86/kernel/microcode_amd.c
@@ -82,11 +82,6 @@ static int collect_cpu_info_amd(int cpu,
{
struct cpuinfo_x86 *c = &cpu_data(cpu);

- if (c->x86_vendor != X86_VENDOR_AMD || c->x86 < 0x10) {
- pr_warning("CPU%d: family %d not supported\n", cpu, c->x86);
- return -1;
- }
-
csig->rev = c->microcode;
pr_info("CPU%d: patch_level=0x%08x\n", cpu, csig->rev);

@@ -380,6 +375,13 @@ static struct microcode_ops microcode_am

struct microcode_ops * __init init_amd_microcode(void)
{
+ struct cpuinfo_x86 *c = &cpu_data(0);
+
+ if (c->x86_vendor != X86_VENDOR_AMD || c->x86 < 0x10) {
+ pr_warning("AMD CPU family 0x%x not supported\n", c->x86);
+ return NULL;
+ }
+
patch = (void *)get_zeroed_page(GFP_KERNEL);
if (!patch)
return NULL;
--- a/arch/x86/kernel/microcode_core.c
+++ b/arch/x86/kernel/microcode_core.c
@@ -511,11 +511,11 @@ static int __init microcode_init(void)
microcode_ops = init_intel_microcode();
else if (c->x86_vendor == X86_VENDOR_AMD)
microcode_ops = init_amd_microcode();
-
- if (!microcode_ops) {
+ else
pr_err("no support for this CPU vendor\n");
+
+ if (!microcode_ops)
return -ENODEV;
- }

microcode_pdev = platform_device_register_simple("microcode", -1,
NULL, 0);