[squid-users] Debugging xfree() (WAS: , in the URL)

While I was trying to debug the changes that some colleagues have made to
squid source code, I came up to the following situation:

Program received signal SIGSEGV, Segmentation fault.
0x4011ddcb in chunk_free () from /lib/libc.so.6

(part of (gdb) where full)
#2 0x080b8623 in xfree (s=0x847c038) at util.c:484
No locals.

(gdb) where
#0 0x4011ddcb in chunk_free () from /lib/libc.so.6
#1 0x4011dc53 in free () from /lib/libc.so.6
#2 0x080b8623 in xfree (s=0x847c038) at util.c:484
#3 0x08065b99 in **A custom function() ** (fd=16) at client_side.c:3613
#4 0x08061512 in clientWriteComplete (fd=16, bufnotused=0x0, size=3295,
    errflag=0, data=0x84792c0) at client_side.c:2096
#5 0x08066994 in CommWriteStateCallbackAndFree (fd=16, code=0) at comm.c:98
#6 0x08068ee0 in commHandleWrite (fd=16, data=0x8471e50) at comm.c:881
#7 0x08069f80 in comm_poll (msec=355) at comm_select.c:446
#8 0x0808d31d in main (argc=2, argv=0xbffff8e4) at main.c:859
#9 0x400c69ed in __libc_start_main () from /lib/libc.so.6
(gdb)

As I understand the problem is the s pointer. It is either NULL or what?
I thought that xfree() was doing all the necessary tests in order to avoid
such errors.
Am I missing something?

many thanks in advance,
Mihalis

----- Original Message -----
From: "Henrik Nordstrom" <hno@squid-cache.org>
To: "Mihalis Tsoukalos" <ekefe@freemail.gr>
Cc: <squid-users@squid-cache.org>
Sent: Monday, March 17, 2003 9:13 AM
Subject: Re: AW: [squid-users] , in the URL

> You use GDB as usual.. a process is a process.
>
> Either use the -N command line option when starting Squid from within
> gdb, or attach to the running process.
>
> Regards
> Henrik
>
> Mihalis Tsoukalos wrote:
> >
> > I have checked it back and I have seen that the problem is not with
Squid.
> >
> > So the question is now:
> > Any hints on how to debug the (modified) squid C code?
> >
> > The reason I am asking is because squid is a server process. I know how
to
> > debug a no-server executable.
> > I am going to use gdb.
> >
> > have a nice week,
> > Mihalis.
Received on Fri Mar 21 2003 - 03:21:19 MST