Commit-ID: 21c5e50e15b1abd797e62f18fd7f90b9cc004cbd Gitweb: http://git.kernel.org/tip/21c5e50e15b1abd797e62f18fd7f90b9cc004cbd Author: Daniel J Blueman <dan...@numascale-asia.com> AuthorDate: Mon, 1 Oct 2012 14:42:05 +0800 Committer: H. Peter Anvin <h...@linux.intel.com> CommitDate: Wed, 17 Oct 2012 11:25:32 -0700
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 <dan...@numascale-asia.com> Cc: sta...@vger.kernel.org # 3.6 Link: http://lkml.kernel.org/r/1349073725-14093-1-git-send-email-dan...@numascale-asia.com [ Boris: beef up commit message ] Signed-off-by: Borislav Petkov <borislav.pet...@amd.com> Signed-off-by: H. Peter Anvin <h...@linux.intel.com> --- arch/x86/kernel/cpu/mcheck/mce_amd.c | 10 +++++----- 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 c4e916d..698b6ec 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, -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
