Re: rcu: BUG on exit_group

[Paul E. McKenney]

On Thu, May 03, 2012 at 05:55:14PM +0200, Sasha Levin wrote:
> On Thu, May 3, 2012 at 5:41 PM, Paul E. McKenney
> <paulmck@xxxxxxxxxxxxxxxxxx> wrote:
> > On Thu, May 03, 2012 at 10:57:19AM +0200, Sasha Levin wrote:
> >> Hi Paul,
> >>
> >> I've hit a BUG similar to the schedule_tail() one when. It happened
> >> when I've started fuzzing exit_group() syscalls, and all of the traces
> >> are starting with exit_group() (there's a flood of them).
> >>
> >> I've verified that it indeed BUGs due to the rcu preempt count.
> >
> > Hello, Sasha,
> >
> > Which version of -next are you using?  I did some surgery on this
> > yesterday based on some bugs Hugh Dickins tracked down, so if you
> > are using something older, please move to the current -next.
> 
> I'm using -next from today (3.4.0-rc5-next-20120503-sasha-00002-g09f55ae-dirty).

Hmmm...  Looking at this more closely, it looks like there really is
an attempt to acquire a mutex within an RCU read-side critical section,
which is illegal.  Could you please bisect this?

							Thanx, Paul

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/