Re: net: possible deadlock in skb_queue_tail

[Cong Wang]

On Mon, Feb 20, 2017 at 5:29 AM, Andrey Konovalov <andreyknvl@xxxxxxxxxx> wrote:
> other info that might help us debug this:
>
>  Possible unsafe locking scenario:
>
>        CPU0                    CPU1
>        ----                    ----
>   lock(&(&pcpu->lock)->rlock);
>                                lock(&(&list->lock)->rlock#3);
>                                lock(&(&pcpu->lock)->rlock);
>   lock(&(&list->lock)->rlock#3);
>

They are different types of sockets and different lists of skb's,
one is netlink socket the other is udp socket, so I don't think
we could have a deadlock in this scenario, we probably need to
explicitly mark them as different lockdep classes.