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 <[email protected]> > Signed-off-by: Frederic Weisbecker <[email protected]> > Cc: Thomas Gleixner <[email protected]> > Cc: Peter Zijlstra <[email protected]> > Cc: Rik van Riel <[email protected]> > Cc: Paul E. McKenney <[email protected]> > Cc: Ingo Molnar <[email protected]> > Cc: Dave Jones <[email protected]> > Cc: Oleg Nesterov <[email protected]>
Reviewed-by: Rik van Riel <[email protected]> -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
