Re: [PATCH net 4/4] tcp: various missing rcu_read_lock around __sk_dst_get
From: Eric Dumazet <hidden>
Date: 2016-04-01 01:39:22
Subsystem:
networking [general], networking [sockets], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Kuniyuki Iwashima, Willem de Bruijn, Linus Torvalds
On Fri, 2016-04-01 at 03:36 +0200, Hannes Frederic Sowa wrote:
On Fri, Apr 1, 2016, at 03:19, Eric Dumazet wrote:quoted
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);