x86/UV: Fix NULL pointer dereference in uv_flush_tlb_others() if the 'nobau' boot...
authorcpw <cpw@sgi.com>
Tue, 3 Dec 2013 23:15:30 +0000 (17:15 -0600)
committerIngo Molnar <mingo@kernel.org>
Tue, 10 Dec 2013 09:06:00 +0000 (10:06 +0100)
commit3eae49ca8954f958b2001ab5643ef302cb7b67c7
tree1af3483e0f6a1929bf79c59a3e9d8d19b23e9d69
parent8b3b005d675726e38bc504d2e35a991e55819155
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>
arch/x86/platform/uv/tlb_uv.c