tcp: provide more information on the tcp receive_queue bugs
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 <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 98440ad..f1813bc 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -1183,7 +1183,9 @@
#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 @@
/* 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 @@
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. */