From: Martin DOT Stromberg AT lu DOT erisoft DOT se (Martin Stromberg)
Newsgroups: comp.os.msdos.djgpp
Subject: gdb crash while debugging df
Date: 13 Feb 1998 14:02:58 GMT
Organization: Ericsson Erisoft AB, Sweden
Lines: 57
Message-ID: <6c1jqi$4di$1@antares.lu.erisoft.se>
NNTP-Posting-Host: juno.lu.erisoft.se
To: djgpp AT delorie DOT com
DJ-Gateway: from newsgroup comp.os.msdos.djgpp
Precedence: bulk

gdb crashed while I debugged df. When I ran it again I looked first at the 
variable before dereferencing it, and it being 0xffffffff I'm not too
surprised that it crashed, but should gdb really _crash_? Is it a bug
in gdb or am I myself to blame?

							MartinS


Here the session with gdb:

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 under certain conditions; type "show copying" to see the conditions.
There is absolutely no warranty for GDB; type "show warranty" for details.
GDB 4.16 (go32), Copyright 1996 Free Software Foundation, Inc...
(gdb) b 755
Breakpoint 1 at 0x2bec: file df.c, line 755.
(gdb) r
Starting program: d:/tmp/fil/gnu/filutil3.16/src/df 

Breakpoint 1, main (argc=1, argv=0x5a090) at df.c:755
755	  mount_list =
(gdb) s
read_filesystem_list (need_fs_type=0, all_fs=0) at mountlist.c:258
258	  me = (struct mount_entry *) xmalloc (sizeof (struct mount_entry));
(gdb) n
259	  me->me_next = NULL;
(gdb) n
260	  mount_list = mtail = me;
(gdb) n
299	    fp = setmntent (table, "r");
(gdb) p mnt
$1 = (struct mntent *) 0xffffffff
(gdb) p *mnt
Cannot continue from exception, exiting due to signal 0123
General Protection Fault at eip=000ae5dd
eax=00000100 ebx=0000001c ecx=00000007 edx=0005ffff esi=ffffffff edi=001381ac
ebp=0011fe44 esp=0011fe34 program=C:\DJGPP\BIN/gdb.exe
cs: sel=00e7  base=10060000  limit=001bffff
ds: sel=012f  base=10220000  limit=0005ffff
es: sel=00ef  base=10060000  limit=001bffff
fs: sel=010f  base=00029560  limit=000040ff
gs: sel=00ff  base=00000000  limit=ffffffff
ss: sel=00ef  base=10060000  limit=001bffff

Call frame traceback EIPs:
  0x000ae5dd
  0x000a4b25
  0x00035090
  0x0003a128
  0x0003a077
  0x0005b927
  0x00013096
  0x0000e039
  0x00019f24
  0x00019ffb
  0x0007253d