[net-next 1/1] tipc: fix broken tipc_poll() function

[Jon Maloy <jon.maloy@ericsson.com>]

In commit ae236fb208a6 ("tipc: receive group membership events via
member socket") we broke the tipc_poll() function by checking the
state of the receive queue before the call to poll_sock_wait(), while
relying that state afterwards, when it might have changed.

We restore this in this commit.

Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
---
 net/tipc/socket.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/net/tipc/socket.c b/net/tipc/socket.c
index 2bbab4f..4cb706a 100644
--- a/net/tipc/socket.c
+++ b/net/tipc/socket.c
@@ -714,7 +714,6 @@ static unsigned int tipc_poll(struct file *file, struct socket *sock,
 			      poll_table *wait)
 {
 	struct sock *sk = sock->sk;
-	struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);
 	struct tipc_sock *tsk = tipc_sk(sk);
 	struct tipc_group *grp = tsk->group;
 	u32 revents = 0;
@@ -733,7 +732,7 @@ static unsigned int tipc_poll(struct file *file, struct socket *sock,
 		/* fall thru' */
 	case TIPC_LISTEN:
 	case TIPC_CONNECTING:
-		if (skb)
+		if (!skb_empty(&sk->sk_receive_queue))
 			revents |= POLLIN | POLLRDNORM;
 		break;
 	case TIPC_OPEN:
@@ -742,7 +741,7 @@ static unsigned int tipc_poll(struct file *file, struct socket *sock,
 				revents |= POLLOUT;
 		if (!tipc_sk_type_connectionless(sk))
 			break;
-		if (!skb)
+		if (skb_empty(&sk->sk_receive_queue))
 			break;
 		revents |= POLLIN | POLLRDNORM;
 		break;
-- 
2.1.4