This is a note to let you know that I've just added the patch titled
x86/UV: Fix NULL pointer dereference in uv_flush_tlb_others() if the 'nobau' boot option is used
to the 3.12-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
x86-uv-fix-null-pointer-dereference-in-uv_flush_tlb_others-if-the-nobau-boot-option-is-used.patch
and it can be found in the queue-3.12 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 3eae49ca8954f958b2001ab5643ef302cb7b67c7 Mon Sep 17 00:00:00 2001
From: cpw <cpw@xxxxxxx>
Date: Tue, 3 Dec 2013 17:15:30 -0600
Subject: x86/UV: Fix NULL pointer dereference in uv_flush_tlb_others() if the 'nobau' boot option is used
From: cpw <cpw@xxxxxxx>
commit 3eae49ca8954f958b2001ab5643ef302cb7b67c7 upstream.
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@xxxxxxx>
Link: http://lkml.kernel.org/r/E1VnzBi-0005yF-MU@xxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/platform/uv/tlb_uv.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
--- 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_other
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);
Patches currently in stable-queue which might be from cpw@xxxxxxx are
queue-3.12/x86-uv-fix-null-pointer-dereference-in-uv_flush_tlb_others-if-the-nobau-boot-option-is-used.patch
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