[parisc-linux] Expect defunct, kill -9 panics kernel?

[John David Anglin]

> On 2/10/07, James Bottomley <James.Bottomley at steeleye.com> wrote:
> > On Sat, 2007-02-10 at 14:37 -0500, John David Anglin wrote:
> > > > 0x10 looks to be curr->func implying curr is NULL and thus the queue
> > > > task_list is corrupt.
> > >
> > > Do you think it help to add a check in __wake_up for a NULL pointer?
> >
> > I suppose so ... I'd really like someone to validate my guess though,
> > although an additional BUG_ON() can't hurt.
> 
> How do I validate your guess? Look for a null or bogus curr->func when
> scheduling?

I'm trying the change below.  Hasn't triggered yet.

Dave
-- 
J. David Anglin                                  dave.anglin at nrc-cnrc.gc.ca
National Research Council of Canada              (613) 990-0752 (FAX: 952-6602)

diff --git a/kernel/sched.c b/kernel/sched.c
index cca93cc..277e426 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -3703,6 +3703,7 @@ void fastcall __wake_up(wait_queue_head_t *q, unsigned int mode,
 {
 	unsigned long flags;
 
+	BUG_ON(!q);
 	spin_lock_irqsave(&q->lock, flags);
 	__wake_up_common(q, mode, nr_exclusive, 0, key);
 	spin_unlock_irqrestore(&q->lock, flags);