From 48766a583c7961af080de2df692f476624a9a21a Mon Sep 17 00:00:00 2001 From: Tung Nguyen Date: Tue, 19 Feb 2019 11:20:48 +0700 Subject: [PATCH] tipc: improve function tipc_wait_for_rcvmsg() This commit replaces schedule_timeout() with wait_woken() in function tipc_wait_for_rcvmsg(). wait_woken() uses memory barriers in its implementation to avoid potential race condition when putting a process into sleeping state and then waking it up. Acked-by: Ying Xue Acked-by: Jon Maloy Signed-off-by: Tung Nguyen Signed-off-by: David S. Miller --- net/tipc/socket.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/net/tipc/socket.c b/net/tipc/socket.c index 81b87916a0eb..684f2125fc6b 100644 --- a/net/tipc/socket.c +++ b/net/tipc/socket.c @@ -1677,7 +1677,7 @@ static void tipc_sk_send_ack(struct tipc_sock *tsk) static int tipc_wait_for_rcvmsg(struct socket *sock, long *timeop) { struct sock *sk = sock->sk; - DEFINE_WAIT(wait); + DEFINE_WAIT_FUNC(wait, woken_wake_function); long timeo = *timeop; int err = sock_error(sk); @@ -1685,15 +1685,17 @@ static int tipc_wait_for_rcvmsg(struct socket *sock, long *timeop) return err; for (;;) { - prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE); if (timeo && skb_queue_empty(&sk->sk_receive_queue)) { if (sk->sk_shutdown & RCV_SHUTDOWN) { err = -ENOTCONN; break; } + add_wait_queue(sk_sleep(sk), &wait); release_sock(sk); - timeo = schedule_timeout(timeo); + timeo = wait_woken(&wait, TASK_INTERRUPTIBLE, timeo); + sched_annotate_sleep(); lock_sock(sk); + remove_wait_queue(sk_sleep(sk), &wait); } err = 0; if (!skb_queue_empty(&sk->sk_receive_queue)) @@ -1709,7 +1711,6 @@ static int tipc_wait_for_rcvmsg(struct socket *sock, long *timeop) if (err) break; } - finish_wait(sk_sleep(sk), &wait); *timeop = timeo; return err; } -- 2.39.5