2003-01-13 02:03:08

by Anders Gustafsson

[permalink] [raw]
Subject: [PATCH] fix locking in /net/ipv4/tcp_ipv4.c

Hi,

the goto-discussion* reminded me of the locking for the seq_file reading in
/net/ipv4/tcp_ipv4.c. If only the header** is read tcp_listen_unlock() is
called without the lock taken.

* there are some lovely gotos in /net/ipv4/tcp_ipv4.c:listening_get_next
** (void *)1 is a marker for the header.

--
Anders Gustafsson - [email protected] - http://0x63.nu/

You can import this changeset into BK by piping this whole message to:
'| bk receive [path to repository]' or apply the patch as usual.

===================================================================


[email protected], 2003-01-07 03:27:31+01:00, [email protected]
Don't tcp_listen_unlock unless it was locked.


tcp_ipv4.c | 3 ++-
1 files changed, 2 insertions(+), 1 deletion(-)


diff -Nru a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
--- a/net/ipv4/tcp_ipv4.c Tue Jan 7 03:41:35 2003
+++ b/net/ipv4/tcp_ipv4.c Tue Jan 7 03:41:35 2003
@@ -2412,7 +2412,8 @@
read_unlock_bh(&tp->syn_wait_lock);
}
case TCP_SEQ_STATE_LISTENING:
- tcp_listen_unlock();
+ if (v != (void *)1)
+ tcp_listen_unlock();
break;
case TCP_SEQ_STATE_TIME_WAIT:
case TCP_SEQ_STATE_ESTABLISHED:

===================================================================


This BitKeeper patch contains the following changesets:
1.973
## Wrapped with gzip_uu ##


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`
end


2003-01-13 08:03:22

by David Miller

[permalink] [raw]
Subject: Re: [PATCH] fix locking in /net/ipv4/tcp_ipv4.c

From: Anders Gustafsson <[email protected]>
Date: Mon, 13 Jan 2003 03:11:50 +0100

the goto-discussion* reminded me of the locking for the seq_file reading in
/net/ipv4/tcp_ipv4.c. If only the header** is read tcp_listen_unlock() is
called without the lock taken.

Applied, thanks.