From d792c1006fe92448217b71513d3955868358271d Mon Sep 17 00:00:00 2001 From: Ilpo Järvinen Date: Fri, 13 Nov 2009 13:56:33 -0800 Subject: tcp: provide more information on the tcp receive_queue bugs MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The addition of rcv_nxt allows to discern whether the skb was out of place or tp->copied. Also catch fancy combination of flags if necessary (sadly we might miss the actual causer flags as it might have already returned). Btw, we perhaps would want to forward copied_seq in somewhere or otherwise we might have some nice loop with WARN stuff within but where to do that safely I don't know at this stage until more is known (but it is not made significantly worse by this patch). Signed-off-by: Ilpo Järvinen Signed-off-by: David S. Miller --- net/ipv4/tcp.c | 19 ++++++++++++------- 1 file changed, 12 insertions(+), 7 deletions(-) (limited to 'net/ipv4') diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 98440ad82558..f1813bc71088 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -1183,7 +1183,9 @@ void tcp_cleanup_rbuf(struct sock *sk, int copied) #if TCP_DEBUG struct sk_buff *skb = skb_peek(&sk->sk_receive_queue); - WARN_ON(skb && !before(tp->copied_seq, TCP_SKB_CB(skb)->end_seq)); + WARN(skb && !before(tp->copied_seq, TCP_SKB_CB(skb)->end_seq), + KERN_INFO "cleanup rbuf bug: copied %X seq %X rcvnxt %X\n", + tp->copied_seq, TCP_SKB_CB(skb)->end_seq, tp->rcv_nxt); #endif if (inet_csk_ack_scheduled(sk)) { @@ -1430,11 +1432,13 @@ int tcp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, /* Now that we have two receive queues this * shouldn't happen. */ - if (before(*seq, TCP_SKB_CB(skb)->seq)) { - printk(KERN_INFO "recvmsg bug: copied %X " - "seq %X\n", *seq, TCP_SKB_CB(skb)->seq); + if (WARN(before(*seq, TCP_SKB_CB(skb)->seq), + KERN_INFO "recvmsg bug: copied %X " + "seq %X rcvnxt %X fl %X\n", *seq, + TCP_SKB_CB(skb)->seq, tp->rcv_nxt, + flags)) break; - } + offset = *seq - TCP_SKB_CB(skb)->seq; if (tcp_hdr(skb)->syn) offset--; @@ -1443,8 +1447,9 @@ int tcp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, if (tcp_hdr(skb)->fin) goto found_fin_ok; WARN(!(flags & MSG_PEEK), KERN_INFO "recvmsg bug 2: " - "copied %X seq %X\n", *seq, - TCP_SKB_CB(skb)->seq); + "copied %X seq %X rcvnxt %X fl %X\n", + *seq, TCP_SKB_CB(skb)->seq, + tp->rcv_nxt, flags); } /* Well, if we have backlog, try to process it now yet. */ -- cgit v1.2.3