Commit cc04410a authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

af_unix: annotate lockless accesses to sk->sk_err 



unix_poll() and unix_dgram_poll() read sk->sk_err
without any lock held.

Add relevant READ_ONCE()/WRITE_ONCE() annotations.

Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 9ae8e5ad

net/unix/af_unix.c

+5 −4
Original line number Diff line number Diff line
@@ -557,7 +557,7 @@ static void unix_dgram_disconnected(struct sock *sk, struct sock *other) 
		 * when peer was not connected to us.

		 */

		if (!sock_flag(other, SOCK_DEAD) && unix_peer(other) == sk) {

			other->sk_err = ECONNRESET;

			WRITE_ONCE(other->sk_err, ECONNRESET);

			sk_error_report(other);

		}

	}
@@ -630,7 +630,7 @@ static void unix_release_sock(struct sock *sk, int embrion) 
			/* No more writes */

			skpair->sk_shutdown = SHUTDOWN_MASK;

			if (!skb_queue_empty(&sk->sk_receive_queue) || embrion)

				skpair->sk_err = ECONNRESET;

				WRITE_ONCE(skpair->sk_err, ECONNRESET);

			unix_state_unlock(skpair);

			skpair->sk_state_change(skpair);

			sk_wake_async(skpair, SOCK_WAKE_WAITD, POLL_HUP);
@@ -3165,7 +3165,7 @@ static __poll_t unix_poll(struct file *file, struct socket *sock, poll_table *wa 
	mask = 0;



	/* exceptional events? */

	if (sk->sk_err)

	if (READ_ONCE(sk->sk_err))

		mask |= EPOLLERR;

	if (sk->sk_shutdown == SHUTDOWN_MASK)

		mask |= EPOLLHUP;
@@ -3208,7 +3208,8 @@ static __poll_t unix_dgram_poll(struct file *file, struct socket *sock, 
	mask = 0;



	/* exceptional events? */

	if (sk->sk_err || !skb_queue_empty_lockless(&sk->sk_error_queue))

	if (READ_ONCE(sk->sk_err) ||

	    !skb_queue_empty_lockless(&sk->sk_error_queue))

		mask |= EPOLLERR |

			(sock_flag(sk, SOCK_SELECT_ERR_QUEUE) ? EPOLLPRI : 0);