[PATCH] lockdep: annotate af_unix locking
Teach special (recursive) locking code to the lock validator. Also splits
af_unix's sk_receive_queue.lock class from the other networking skb-queue
locks. Has no effect on non-lockdep kernels.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index aca6501..e9a287b 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -565,6 +565,14 @@
.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 socket *sock)
{
struct sock *sk = NULL;
@@ -580,6 +588,8 @@
atomic_inc(&unix_nr_socks);
sock_init_data(sock,sk);
+ lockdep_set_class(&sk->sk_receive_queue.lock,
+ &af_unix_sk_receive_queue_lock_key);
sk->sk_write_space = unix_write_space;
sk->sk_max_ack_backlog = sysctl_unix_max_dgram_qlen;
@@ -1045,7 +1055,7 @@
goto out_unlock;
}
- unix_state_wlock(sk);
+ unix_state_wlock_nested(sk);
if (sk->sk_state != st) {
unix_state_wunlock(sk);