On 01.04.2016 03:45, Eric Dumazet wrote:
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()
I thought so first, as well. But given the double check for the
spin_lock and the "mutex" we end up with the same result for the
lockdep_sock_is_held check.
Do you see other consequences?
Thanks,
Hannes
