[patch 47/48] x86: microcode_amd: fix wrong handling of equivalent CPU id

Greg KH
2009-02-14T01:47:54Z

[-- Attachment #1: x86-microcode_amd-fix-wrong-handling-of-equivalent-cpu-id.patch --]
[-- Type: text/plain, Size: 2190 bytes --]

2.6.28-stable review patch. If anyone has any objections, please let us know.

------------------

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

commit 3c763fd77e66e55d029052da31df0abd9920cb1e upstream.

Impact: fix bug resulting in non-loaded AMD microcode

mc_header->processor_rev_id is a 2 byte value. Similar is true for
equiv_cpu in an equiv_cpu_entry -- only 2 bytes are of interest.

Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
arch/x86/kernel/microcode_amd.c | 23 ++++++-----------------
1 file changed, 6 insertions(+), 17 deletions(-)

--- a/arch/x86/kernel/microcode_amd.c
+++ b/arch/x86/kernel/microcode_amd.c
@@ -62,7 +62,7 @@ struct microcode_header_amd {
unsigned int mc_patch_data_checksum;
unsigned int nb_dev_id;
unsigned int sb_dev_id;
- unsigned char processor_rev_id[2];
+ u16 processor_rev_id;
unsigned char nb_rev_id;
unsigned char sb_rev_id;
unsigned char bios_api_rev;
@@ -125,7 +125,7 @@ static int get_matching_microcode(int cp

while (equiv_cpu_table[i].installed_cpu != 0) {
if (current_cpu_id == equiv_cpu_table[i].installed_cpu) {
- equiv_cpu_id = equiv_cpu_table[i].equiv_cpu;
+ equiv_cpu_id = equiv_cpu_table[i].equiv_cpu & 0xffff;
break;
}
i++;
@@ -137,21 +137,10 @@ static int get_matching_microcode(int cp
return 0;
}

- if ((mc_header->processor_rev_id[0]) != (equiv_cpu_id & 0xff)) {
- printk(KERN_ERR
- "microcode: CPU%d patch does not match "
- "(patch is %x, cpu extended is %x) \n",
- cpu, mc_header->processor_rev_id[0],
- (equiv_cpu_id & 0xff));
- return 0;
- }
-
- if ((mc_header->processor_rev_id[1]) != ((equiv_cpu_id >> 16) & 0xff)) {
- printk(KERN_ERR "microcode: CPU%d patch does not match "
- "(patch is %x, cpu base id is %x) \n",
- cpu, mc_header->processor_rev_id[1],
- ((equiv_cpu_id >> 16) & 0xff));
-
+ if (mc_header->processor_rev_id != equiv_cpu_id) {
+ printk(KERN_ERR "microcode: CPU%d patch does not match "
+ "(processor_rev_id: %x, eqiv_cpu_id: %x)\n",
+ cpu, mc_header->processor_rev_id, equiv_cpu_id);
return 0;
}