Re: WARNING in port_delete

[Paul E. McKenney]

On Mon, Apr 01, 2019 at 12:58:01AM -0700, syzbot wrote:
> syzbot has bisected this bug to:
> 
> commit 63d86a7e85f84b8ac3b2f394570965aedbb03787
> Author: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
> Date:   Tue May 1 20:08:46 2018 +0000
> 
>     rcu: Convert rcu_grace_period_init tracepoint to gp_seq
> 
> bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=17f86d2f200000
> start commit:   091a1eaa Merge branch 'akpm'
> git tree:       upstream
> final crash:    https://syzkaller.appspot.com/x/report.txt?x=14046d2f200000
> console output: https://syzkaller.appspot.com/x/log.txt?x=10046d2f200000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=c0af03fe452b65fb
> dashboard link: https://syzkaller.appspot.com/bug?extid=e4c8abb920efa77bace9
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=102e2c91400000
> 
> Reported-by: syzbot+e4c8abb920efa77bace9@xxxxxxxxxxxxxxxxxxxxxxxxx
> Fixes: 63d86a7e85f8 ("rcu: Convert rcu_grace_period_init tracepoint
> to gp_seq")

I could easily be suffering from a lack of imagination, but I am not
seeing how this change to RCU's event tracing could cause this result.
Especially given that CONFIG_RCU_TRACE=n in your .config.

What am I missing here?

							Thanx, Paul

> For information about bisection process see: https://goo.gl/tpsmEJ#bisection
>