On Fri, Oct 26, 2012 at 11:44:11AM +0200, Frederic Weisbecker wrote:
> 2012/10/25 Sergey Senozhatsky <sergey.senozhat...@gmail.com>:
> > On (10/25/12 09:06), Frederic Weisbecker wrote:
> >> >> > My understanding is (I may be wrong) that we can schedule() from
> >> >> > ptrace chain to
> >> >> > some arbitrary task, which will continue its execution from the
> >> >> > point where RCU assumes
> >> >> > CPU as not idle, while CPU in fact still in idle state -- no one
> >> >> > said rcu_idle_exit()
> >> >> > (or similar) prior to schedule() call.
> >> >>
> >> >> Yeah but when we are in syscall_trace_leave(), the CPU shouldn't be in
> >> >> RCU idle mode. That's where the bug is. How do you manage to trigger
> >> >> this bug?
> >> >
> >> > strace -f <anything>
> >> I can't reproduce. Can you send me your config?
> >
> > sure, attached.
>
> Thanks.
>
> Sergey, Dave,
>
> Does the patch I just sent you fix the issue?
I only saw this happening after hours of fuzzing.
Right now I keep running into other issues before that gets a chance to happen,
so I've not seen it in a while.
I'll apply it to my tree, and run with it though.
If I see it again, you'll be first to know :)
Dave
--
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/
