Matt Schalit wrote: > 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
> 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. However, you didn't mention lines 182 and 185; for these lines I get: 182 if ( n < 0 || n != ping_pkt_size ) 185 free ( buffer ) ; Here's a debugging session: Script started on Wed Oct 31 09:53:02 2001 # gdb ./gatping GNU gdb 19991004 Copyright 1998 Free Software Foundation, Inc. GDB is free software, covered by the GNU General Public License, and you are welcome to change it and/or distribute copies of it under certain conditions. Type "show copying" to see the conditions. There is absolutely no warranty for GDB. Type "show warranty" for details. This GDB was configured as "i386-redhat-linux"... (gdb) break send_ping Breakpoint 1 at 0x8048878: file gatping.c, line 161. (gdb) r Starting program: /pub/oxygen/src/net/gatping/EchoWare_0.46/gatping_0.2/./gatping Breakpoint 1, send_ping (s=5, h=0x804ac58) at gatping.c:161 161 buffer = ( char * ) malloc ( ( size_t ) ping_pkt_size ) ; (gdb) n 162 memset ( buffer, 0, ping_pkt_size * sizeof ( char ) ) ; (gdb) p buffer $1 = 0x804a398 "P\235\020@P\235\020@\020" (gdb) n 166 icp->icmp_type = ICMP_ECHO ; (gdb) p buffer $2 = 0x804a398 "" (gdb) n 167 icp->icmp_code = 0 ; (gdb) n 168 icp->icmp_cksum = 0 ; (gdb) n 169 icp->icmp_seq = 1 ; (gdb) n 170 icp->icmp_id = ident ; (gdb) n 173 gettimeofday (&pdp->ping_ts, &tz ) ; (gdb) n 174 pdp->ping_count = 1 ; (gdb) n 175 icp->icmp_cksum = ( in_cksum ( ( u_short * ) icp, ping_pkt_size ) ) ; (gdb) n 179 n = sendto ( mysock , buffer, ping_pkt_size, 0, (gdb) p buffer $3 = 0x804a398 "\b" (gdb) n 182 if ( n < 0 || n != ping_pkt_size ) (gdb) p n $4 = 8 (gdb) p ping_pkt_size $5 = 8 (gdb) n 185 free ( buffer ) ; (gdb) p buffer $6 = 0x804a398 "\b" (gdb) n Program received signal SIGSEGV, Segmentation fault. 0x400750c4 in chunk_free (ar_ptr=0x40109d40, p=0x804a390) at malloc.c:3100 3100 malloc.c: No such file or directory. (gdb) quit The program is running. Exit anyway? (y or n) y # exit Script done on Wed Oct 31 09:54:22 2001 Looks to me like the call to free(3) is failing, but I can't see why. Buffer is char * and is allocated up above, and doesn't seem to be free'd elsewhere. _______________________________________________ Leaf-devel mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/leaf-devel
