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authorcpw <cpw@sgi.com>2013-12-04 00:15:30 +0100
committerIngo Molnar <mingo@kernel.org>2013-12-10 10:06:00 +0100
commit3eae49ca8954f958b2001ab5643ef302cb7b67c7 (patch)
tree1af3483e0f6a1929bf79c59a3e9d8d19b23e9d69 /arch
parentx86, build: Pass in additional -mno-mmx, -mno-sse options (diff)
downloadlinux-3eae49ca8954f958b2001ab5643ef302cb7b67c7.tar.xz
linux-3eae49ca8954f958b2001ab5643ef302cb7b67c7.zip
x86/UV: Fix NULL pointer dereference in uv_flush_tlb_others() if the 'nobau' boot option is used
The SGI UV tlb shootdown code panics the system with a NULL pointer deference if 'nobau' is specified on the boot commandline. uv_flush_tlb_other() gets called for every flush, whether the BAU is disabled or not. It should not be keeping the s_enters statistic while the BAU is disabled. The panic occurs because during initialization init_per_cpu_tunables() does not set the bcp->statp pointer if 'nobau' was specified. Signed-off-by: Cliff Wickman <cpw@sgi.com> Cc: <stable@vger.kernel.org> # 3.12.x Link: http://lkml.kernel.org/r/E1VnzBi-0005yF-MU@eag09.americas.sgi.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/platform/uv/tlb_uv.c5
1 files changed, 3 insertions, 2 deletions
diff --git a/arch/x86/platform/uv/tlb_uv.c b/arch/x86/platform/uv/tlb_uv.c
index 0f92173a12b6..efe4d7220397 100644
--- a/arch/x86/platform/uv/tlb_uv.c
+++ b/arch/x86/platform/uv/tlb_uv.c
@@ -1070,12 +1070,13 @@ const struct cpumask *uv_flush_tlb_others(const struct cpumask *cpumask,
unsigned long status;
bcp = &per_cpu(bau_control, cpu);
- stat = bcp->statp;
- stat->s_enters++;
if (bcp->nobau)
return cpumask;
+ stat = bcp->statp;
+ stat->s_enters++;
+
if (bcp->busy) {
descriptor_status =
read_lmmr(UVH_LB_BAU_SB_ACTIVATION_STATUS_0);