On Mon, May 05, 2014 at 01:10:55PM -0400, Vince Weaver wrote: > On Mon, 5 May 2014, Vince Weaver wrote: > > > (Although often things like to crash the instant my tested-by e-mails > > clear the lkml list.) > > This did turn up on the core2 machine. I had been seeing this problem > earlier but was hoping it was part of the memory corruption issue: > > [ 4918.921921] BUG: unable to handle kernel NULL pointer dereference at > 0000000000000010 > [ 4918.925692] IP: [<ffffffff81539fa6>] mutex_lock+0x19/0x37
> [ 4918.925692] Call Trace: > [ 4918.925692] [<ffffffff810d10b7>] perf_event_init_context+0x7c/0x1c8 > [ 4918.925692] [<ffffffff810d126c>] perf_event_init_task+0x69/0x6d > [ 4918.925692] [<ffffffff8103e1ff>] copy_process+0x5cc/0x163b > [ 4918.925692] [<ffffffff8103f536>] do_fork+0x74/0x1dc > [ 4918.925692] [<ffffffff8103f6b4>] SyS_clone+0x16/0x18 > [ 4918.925692] [<ffffffff81542c89>] stub_clone+0x69/0x90 Cute.. does the below cure? --- Subject: perf: Fix perf_event_init_context() From: Peter Zijlstra <pet...@infradead.org> Date: Mon May 5 19:12:20 CEST 2014 perf_pin_task_context() can return NULL but perf_event_init_context() assumes it will not, correct this. Signed-off-by: Peter Zijlstra <pet...@infradead.org> --- kernel/events/core.c | 2 ++ 1 file changed, 2 insertions(+) --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -7745,6 +7745,8 @@ int perf_event_init_context(struct task_ * swapped under us. */ parent_ctx = perf_pin_task_context(parent, ctxn); + if (!parent_ctx) + return 0; /* * No need to check if parent_ctx != NULL here; since we saw -- 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/