Commit 81970da6 authored Jul 17, 2018 by Randy Dunlap Committed by Greg Kroah-Hartman Aug 24, 2018

tcp: identify cryptic messages as TCP seq # bugs



[ Upstream commit e56b8ce363a36fb7b74b80aaa5cc9084f2c908b4 ]

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>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 780e559a

net/ipv4/tcp.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -1659,7 +1659,7 @@ 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),
		"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;
		@@ -1672,7 +1672,7 @@ 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),
		"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);
		}