> #include <stdio.h>
> #include <unistd.h>
> #include <sys/types.h>
> #include <sys/socket.h>
>
> int
> main(int argc, const char* argv[])
> {
> int retval;
> int sockets[2];
> char buf[1];
>
> retval = socketpair(PF_UNIX, SOCK_DGRAM, 0, sockets);
> if (retval != 0)
> {
> perror("socketpair");
> exit(1);
> }
> shutdown(sockets[0], SHUT_RDWR);
> read(sockets[0], buf, 1);
> }
I tried to debug this issue with the kdb on 2.4.1-pre7.
Here is the stack trace
mcount+0x1f9
wait_for_packet+0x13
skb_recv_datagram+0xbb
unix_dgram_recvmsg+0x53
sock_recvmsg+0x41
sock_read+0x8f
sys_read+0xa4
system_call+0x3c
I looked at the skb_recv_datagram code and noticed that wait_for_packet is not
returning an error, even while trying to read a closed socket.
Anyways here is a patch against 2.4.1 that will fix the issue.
Please feel free to flame me about the patch :)
thanks
--
Prasanna Subash --- [EMAIL PROTECTED] --- TurboLinux, INC
------------------------------------------------------------------------
Linux, the choice | Q: How do you keep a moron in suspense?
of a GNU generation -o) |
Kernel 2.2.16 /\\ |
on a i686 _\\_v |
|
------------------------------------------------------------------------
--- 2.4.1/net/core/datagram.c Fri Feb 2 01:00:10 2001
+++ linux/net/core/datagram.c Fri Feb 2 01:06:59 2001
@@ -74,15 +74,15 @@
if (error)
goto out;
- if (!skb_queue_empty(&sk->receive_queue))
- goto ready;
-
+ error = -ENOTCONN;
/* Socket shut down? */
if (sk->shutdown & RCV_SHUTDOWN)
goto out;
+ if (!skb_queue_empty(&sk->receive_queue))
+ goto ready;
+
/* Sequenced packets can come disconnected. If so we report the problem */
- error = -ENOTCONN;
if(connection_based(sk) && !(sk->state==TCP_ESTABLISHED || sk->state==TCP_LISTEN))
goto out;
PGP signature
