On 04/02/2015 01:39 PM, Frederic Weisbecker wrote: > Context tracking recursion can happen when an exception triggers in the > middle of a call to a context tracking probe. > > This special case can be caused by vmalloc faults. If an access to a > memory area allocated by vmalloc happens in the middle of > context_tracking_enter(), we may run into an endless fault loop because > the exception in turn calls context_tracking_enter() which faults on > the same vmalloc'ed memory, triggering an exception again, etc... > > Some rare crashes have been reported so lets protect against this with > a recursion counter. > > Reported-by: Dave Jones <da...@redhat.com> > Signed-off-by: Frederic Weisbecker <fweis...@gmail.com> > Cc: Thomas Gleixner <t...@linutronix.de> > Cc: Peter Zijlstra <pet...@infradead.org> > Cc: Rik van Riel <r...@redhat.com> > Cc: Paul E. McKenney <paul...@linux.vnet.ibm.com> > Cc: Ingo Molnar <mi...@kernel.org> > Cc: Dave Jones <da...@redhat.com> > Cc: Oleg Nesterov <o...@redhat.com>
Reviewed-by: Rik van Riel <r...@redhat.com> -- 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/
