[PATCH] x86, AMD, MCE: Prevent oops on multi-server system
From: Daniel J Blueman
Date: Mon Oct 01 2012 - 02:42:05 EST
When booting on a federated multi-server system (NumaScale), the
processor Northbridge lookup returns NULL; add guards to prevent this
causing an oops.
On those systems, the northbridge is accessed through MMIO and the
"normal" northbridge enumeration in amd_nb.c doesn't work since we're
generating the northbridge ID from the initial APIC ID and the last
is not unique on those systems. Long story short, we end up without
northbridge descriptors.
Signed-off-by: Daniel J Blueman <daniel@xxxxxxxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx # 3.6
Link: http://lkml.kernel.org/r/1349073725-14093-1-git-send-email-daniel@xxxxxxxxxxxxxxxxxx
[ Boris: beef up commit message ]
Signed-off-by: Borislav Petkov <borislav.petkov@xxxxxxx>
---
arch/x86/kernel/cpu/mcheck/mce_amd.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/arch/x86/kernel/cpu/mcheck/mce_amd.c b/arch/x86/kernel/cpu/mcheck/mce_amd.c
index c4e916d77378..698b6ec12e0f 100644
--- a/arch/x86/kernel/cpu/mcheck/mce_amd.c
+++ b/arch/x86/kernel/cpu/mcheck/mce_amd.c
@@ -576,12 +576,10 @@ static __cpuinit int threshold_create_bank(unsigned int cpu, unsigned int bank)
int err = 0;
if (shared_bank[bank]) {
-
nb = node_to_amd_nb(amd_get_nb_id(cpu));
- WARN_ON(!nb);
/* threshold descriptor already initialized on this node? */
- if (nb->bank4) {
+ if (nb && nb->bank4) {
/* yes, use it */
b = nb->bank4;
err = kobject_add(b->kobj, &dev->kobj, name);
@@ -615,8 +613,10 @@ static __cpuinit int threshold_create_bank(unsigned int cpu, unsigned int bank)
atomic_set(&b->cpus, 1);
/* nb is already initialized, see above */
- WARN_ON(nb->bank4);
- nb->bank4 = b;
+ if (nb) {
+ WARN_ON(nb->bank4);
+ nb->bank4 = b;
+ }
}
err = allocate_threshold_blocks(cpu, bank, 0,
--
1.7.11.rc1
--
Regards/Gruss,
Boris.
Advanced Micro Devices GmbH
Einsteinring 24, 85609 Dornach
GM: Alberto Bozzo
Reg: Dornach, Landkreis Muenchen
HRB Nr. 43632 WEEE Registernr: 129 19551
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