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authorDaniel J Blueman <daniel@numascale-asia.com>2012-10-01 14:42:05 +0800
committerH. Peter Anvin <hpa@linux.intel.com>2012-10-17 11:25:32 -0700
commit21c5e50e15b1abd797e62f18fd7f90b9cc004cbd (patch)
tree455bfc86f8f51fc5e235c8ddaf9366745b1f082f /arch/x86
parent1bbbbe779aabe1f0768c2bf8f8c0a5583679b54a (diff)
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x86, amd, mce: Avoid NULL pointer reference on CPU northbridge lookup
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@numascale-asia.com> Cc: stable@vger.kernel.org # 3.6 Link: http://lkml.kernel.org/r/1349073725-14093-1-git-send-email-daniel@numascale-asia.com [ Boris: beef up commit message ] Signed-off-by: Borislav Petkov <borislav.petkov@amd.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/kernel/cpu/mcheck/mce_amd.c10
1 files 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 c4e916d7737..698b6ec12e0 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,