af_unix: remove redundant lockdep class

After commit 581319c58600 ("net/socket: use per af lockdep classes for sk queues")
sock queue locks now have per-af lockdep classes, including unix socket.
It is no longer necessary to workaround it.

I noticed this while looking at a syzbot deadlock report, this patch
itself doesn't fix it (this is why I don't add Reported-by).

Fixes: 581319c58600 ("net/socket: use per af lockdep classes for sk queues")
Cc: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index aded82d..68bb70a 100644 (file)
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -745,14 +745,6 @@ static struct proto unix_proto = {
        .obj_size               = sizeof(struct unix_sock),
 };
 
-/*
- * AF_UNIX sockets do not interact with hardware, hence they
- * dont trigger interrupts - so it's safe for them to have
- * bh-unsafe locking for their sk_receive_queue.lock. Split off
- * this special lock-class by reinitializing the spinlock key:
- */
-static struct lock_class_key af_unix_sk_receive_queue_lock_key;
-
 static struct sock *unix_create1(struct net *net, struct socket *sock, int kern)
 {
        struct sock *sk = NULL;
@@ -767,8 +759,6 @@ static struct sock *unix_create1(struct net *net, struct socket *sock, int kern)
                goto out;
 
        sock_init_data(sock, sk);
-       lockdep_set_class(&sk->sk_receive_queue.lock,
-                               &af_unix_sk_receive_queue_lock_key);
 
        sk->sk_allocation       = GFP_KERNEL_ACCOUNT;
        sk->sk_write_space      = unix_write_space;