tcp: identify cryptic messages as TCP seq # bugs

Attempt to make cryptic TCP seq number error messages clearer by
(1) identifying the source of the message as "TCP", (2) identifying the
errors as "seq # bug", and (3) grouping the field identifiers and values
by separating them with commas.

E.g., the following message is changed from:

recvmsg bug 2: copied 73BCB6CD seq 70F17CBE rcvnxt 73BCB9AA fl 0
WARNING: CPU: 2 PID: 1501 at /linux/net/ipv4/tcp.c:1881 tcp_recvmsg+0x649/0xb90

to:

TCP recvmsg seq # bug 2: copied 73BCB6CD, seq 70F17CBE, rcvnxt 73BCB9AA, fl 0
WARNING: CPU: 2 PID: 1501 at /linux/net/ipv4/tcp.c:2011 tcp_recvmsg+0x694/0xba0

Suggested-by: 積丹尼 Dan Jacobson <jidanni@jidanni.org>
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index ec2186e3087fd6dadfead589a32dc8ca428f2044..4491faf83f4f93cf4384f7b192ffe3022567cc0a 100644 (file)
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -1998,7 +1998,7 @@ int tcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int nonblock,
                         * shouldn't happen.
                         */
                        if (WARN(before(*seq, TCP_SKB_CB(skb)->seq),
                         * shouldn't happen.
                         */
                        if (WARN(before(*seq, TCP_SKB_CB(skb)->seq),

-                                "recvmsg bug: copied %X seq %X rcvnxt %X fl %X\n",
+                                "TCP recvmsg seq # bug: copied %X, seq %X, rcvnxt %X, fl %X\n",

                                 *seq, TCP_SKB_CB(skb)->seq, tp->rcv_nxt,
                                 flags))
                                break;
                                 *seq, TCP_SKB_CB(skb)->seq, tp->rcv_nxt,
                                 flags))
                                break;


@@ -2013,7 +2013,7 @@ int tcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int nonblock,
                        if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)
                                goto found_fin_ok;
                        WARN(!(flags & MSG_PEEK),
                        if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)
                                goto found_fin_ok;
                        WARN(!(flags & MSG_PEEK),

-                            "recvmsg bug 2: copied %X seq %X rcvnxt %X fl %X\n",
+                            "TCP recvmsg seq # bug 2: copied %X, seq %X, rcvnxt %X, fl %X\n",

                             *seq, TCP_SKB_CB(skb)->seq, tp->rcv_nxt, flags);
                }
 
                             *seq, TCP_SKB_CB(skb)->seq, tp->rcv_nxt, flags);
                }