Re: [Leaf-devel] gatping with debugging symbols

[Matt S. <msc...@pa...>]

David Douthitt wrote:
> 
> Here it is, compiled against 2.1.3....
> 

Thanks.  Here we go.....

-----------------------------------------------------------------
(gdb) file /tmp/gatping
Reading symbols from /tmp/gatping...done.
(gdb) run
Starting program: /tmp/gatping
warning: Unable to find dynamic linker breakpoint function.
warning: GDB will be unable to debug shared library initializers
warning: and track explicitly loaded dynamic code.

Program received signal SIGSEGV, Segmentation fault.
0x17f0c4 in   ()
(gdb) bt
#0  0x17f0c4 in   ()
#1  0x17ef9a in   ()
#2  0x8048918 in send_ping (s=5, h=0x804a958) at gatping.c:185
#3  0x8048851 in main (argc=1, argv=0xbffffdd4) at gatping.c:133
#4  0x13d9cb in   ()
-----------------------------------------------------------------




Ok.  So let's take a closer look at what
send_ping is doing.  I'll set a breakpoint
at the send_ping() function:


(gdb) b send_ping
Breakpoint 1 at 0x8048878: file gatping.c, line 161.


Ok.  Now I'll run the program again, and
then step through the functions in send_ping()
with a while loop.  The numbers are the line
numbers in gatping.c.

----------------------------------------------------------------
(gdb) run
Starting program: /tmp/gatping
warning: Unable to find dynamic linker breakpoint function.
warning: GDB will be unable to debug shared library initializers
warning: and track explicitly loaded dynamic code.

Breakpoint 1, send_ping (s=5, h=0x804a958) at gatping.c:161
Source file is more recent than executable.
161             /* gettimeofday ( &h->last_send_time, &tz )     ; */
(gdb) while 1
 > step
 > end
162             icp->icmp_type = ICMP_ECHO      ;
166             icp->icmp_id = ident            ;
167
168             pdp = ( PING_DATA * ) ( buffer + SIZE_ICMP_HDR )        ;
169             gettimeofday (&pdp->ping_ts, &tz )      ;
170             pdp->ping_count = 1             ;
173
174             /* this is the line that does the actual work, BTW */
175             n = sendto ( mysock , buffer, ping_pkt_size, 0,
in_cksum (p=0x804a398, n=8) at gatping.c:304
304             *(u_char *)(&odd_byte) = *(u_char *)p;
312
send_ping (s=5, h=0x804a958) at gatping.c:179
179                     printf ( "Problem with ping - returned %d\n",n )  ;
182
185

Program received signal SIGSEGV, Segmentation fault.
0x17f0c4 in   ()
Single stepping until exit from function __libc_free,
which has no line number information.

Program terminated with signal SIGSEGV, Segmentation fault.
The program no longer exists.
The program is not being run.
(gdb)
----------------------------------------------------------------------------


So I'm figuring something with the printf(), because there
ain't no printf'ing going on that I see.

If David's reading, he might be able to recall if we were
having printf problems when converting over to 2.1.3.  That
was some months ago.  This may be the last segfault hurdle.

Thanks,
Yurtle