On Thu, 2016-03-31 at 18:39 -0700, Eric Dumazet wrote:
> On Fri, 2016-04-01 at 03:36 +0200, Hannes Frederic Sowa wrote:
> > On Fri, Apr 1, 2016, at 03:19, Eric Dumazet wrote:
> > > Thanks.
> > >
> > > As you can see, release_sock() messes badly lockdep (once your other
> > > patches are in )
> > >
> > > Once we properly fix release_sock() and/or __release_sock(), all these
> > > false positives disappear.
> >
> > This was a loopback connection. I need to study release_sock and
> > __release_sock more as I cannot currently see an issue with the lockdep
> > handling.
>
> Okay, please try :
>
> diff --git a/net/core/sock.c b/net/core/sock.c
> index b67b9aedb230..570dcd91d64e 100644
> --- a/net/core/sock.c
> +++ b/net/core/sock.c
> @@ -2429,10 +2429,6 @@ EXPORT_SYMBOL(lock_sock_nested);
>
> void release_sock(struct sock *sk)
> {
> - /*
> - * The sk_lock has mutex_unlock() semantics:
> - */
> - mutex_release(&sk->sk_lock.dep_map, 1, _RET_IP_);
>
> spin_lock_bh(&sk->sk_lock.slock);
> if (sk->sk_backlog.tail)
> @@ -2445,6 +2441,10 @@ void release_sock(struct sock *sk)
> sk->sk_prot->release_cb(sk);
>
> sock_release_ownership(sk);
> + /*
> + * The sk_lock has mutex_unlock() semantics:
> + */
> + mutex_release(&sk->sk_lock.dep_map, 1, _RET_IP_);
> if (waitqueue_active(&sk->sk_lock.wq))
> wake_up(&sk->sk_lock.wq);
> spin_unlock_bh(&sk->sk_lock.slock);
Also take a look at commit c3f9b01849ef3bc69024990092b9f42e20df7797
We might need to include the mutex_release() in sock_release_ownership()
Thanks !
