From 49d09007879ce7bee36ab453c73e97c00adce884 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Thu, 3 Dec 2009 16:06:13 -0800 Subject: tcp: diag: Dont report negative values for rx queue Both netlink and /proc/net/tcp interfaces can report transient negative values for rx queue. ss -> State Recv-Q Send-Q Local Address:Port Peer Address:Port ESTAB -6 6 127.0.0.1:45956 127.0.0.1:3333 netstat -> tcp 4294967290 6 127.0.0.1:37784 127.0.0.1:3333 ESTABLISHED This is because we dont lock socket while computing tp->rcv_nxt - tp->copied_seq, and another CPU can update copied_seq before rcv_next in RX path. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- net/ipv4/tcp_diag.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'net/ipv4/tcp_diag.c') diff --git a/net/ipv4/tcp_diag.c b/net/ipv4/tcp_diag.c index fcbcd4ff6c5f..939edb3b8e4d 100644 --- a/net/ipv4/tcp_diag.c +++ b/net/ipv4/tcp_diag.c @@ -27,7 +27,7 @@ static void tcp_diag_get_info(struct sock *sk, struct inet_diag_msg *r, r->idiag_rqueue = sk->sk_ack_backlog; r->idiag_wqueue = sk->sk_max_ack_backlog; } else { - r->idiag_rqueue = tp->rcv_nxt - tp->copied_seq; + r->idiag_rqueue = max_t(int, tp->rcv_nxt - tp->copied_seq, 0); r->idiag_wqueue = tp->write_seq - tp->snd_una; } if (info != NULL) -- cgit v1.2.3-59-g8ed1b