3.12-stable review patch. If anyone has any objections, please let me know.
------------------ From: cpw <c...@sgi.com> 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 <c...@sgi.com> Link: http://lkml.kernel.org/r/e1vnzbi-0005yf...@eag09.americas.sgi.com Signed-off-by: Ingo Molnar <mi...@kernel.org> Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org> --- 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); -- 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/
