diff options
| author | cpw <cpw@sgi.com> | 2013-12-03 17:15:30 -0600 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-12-20 07:49:01 -0800 |
| commit | 6a4204b8c03b92947d338c804132ac782a24cc7d (patch) | |
| tree | 7a99fe7f869f08944eb949f908914908116e1f75 /arch/x86 | |
| parent | 9952005841964ea98f24bd402e22b13fd8398368 (diff) | |
x86/UV: Fix NULL pointer dereference in uv_flush_tlb_others() if the 'nobau' boot option is used
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@sgi.com>
Link: http://lkml.kernel.org/r/E1VnzBi-0005yF-MU@eag09.americas.sgi.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/platform/uv/tlb_uv.c | 5 |
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); |