[TCP]: Show all SYN_RECV sockets in /proc/net/tcp

I was fixing the tcp_diag so that it shows SYN_RECV sockets properly.
I found that /proc/net/tcp didn't do it correctly either.  So here is
a small patch to fix /proc/net/tcp.

The logic in there stinks though so I'd love to see a rewrite.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv4/tcp_ipv4.c

@@ -2175,8 +2175,14 @@ static void *listening_get_next(struct seq_file *seq, void *cur)
 		sk	  = sk_next(st->syn_wait_sk);
 		st->state = TCP_SEQ_STATE_LISTENING;
 		read_unlock_bh(&tp->syn_wait_lock);
-	} else
+	} else {
+	       	tp = tcp_sk(sk);
+		read_lock_bh(&tp->syn_wait_lock);
+		if (tp->listen_opt && tp->listen_opt->qlen)
+			goto start_req;
+		read_unlock_bh(&tp->syn_wait_lock);
 		sk = sk_next(sk);
+	}
 get_sk:
 	sk_for_each_from(sk, node) {
 		if (sk->sk_family == st->family) {
@@ -2186,6 +2192,7 @@ static void *listening_get_next(struct seq_file *seq, void *cur)
 	       	tp = tcp_sk(sk);
 		read_lock_bh(&tp->syn_wait_lock);
 		if (tp->listen_opt && tp->listen_opt->qlen) {
+start_req:
 			st->uid		= sock_i_uid(sk);
 			st->syn_wait_sk = sk;
 			st->state	= TCP_SEQ_STATE_OPENREQ;