Re: gdb 6.6: incomplete backtraces ?

[Markus.Grunwald@pruftechnik.com]

Hello,

> 
--------------------------------------------------------------------------------
> > gru@CMDevLin2 >/home/gru/gdb-6.6/bin/gdb dafit_x86.bin 
> > GNU gdb 6.6
> > (gdb) catch fork
> > Catchpoint 1 (fork)
> > (gdb) run
> > [...]
> > Catchpoint 1 (forked process 26023), 0xb7fa1410 in ?? ()
> > (gdb) bt
> > #0  0xb7fa1410 in ?? ()
> > #1  0x00000001 in ?? ()
> > #2  0x00000000 in ?? ()
> > (gdb) show backtrace limit
> > An upper bound on the number of backtrace levels is unlimited.
> > 
> 
--------------------------------------------------------------------------------
> > 
> > Hey, that's quite short ! No matter which catchpoint is hit, I get 
only 3 
> > frames ...
> 
> What does info shared say is at that address?  Anything?

Catchpoint 1 (forked process 27093), 0xb7f10410 in ?? ()
(gdb) bt
#0  0xb7f10410 in ?? ()
#1  0x00000001 in ?? ()
#2  0x00000000 in ?? ()
(gdb) info shared
From        To          Syms Read   Shared Object Library
0xb7f11790  0xb7f222cf  Yes         /lib/ld-linux.so.2
0xb7eeb0e0  0xb7ef7a74  Yes         /lib/libbz2.so.1.0
0xb7700f40  0xb7bf0880  Yes         /opt/qt/x86/qt3/lib/libqt-mt.so.3
[...]

Hmm, seems we didn't hit anything... 
This is for gdb 6.3:

Catchpoint 1 (forked process 27776), 0xb7f77410 in ?? ()
(gdb) bt
#0  0xb7f77410 in ?? ()
#1  0x00000001 in ?? ()
#2  0x00000000 in ?? ()
#3  0xb728761e in strtold_l () from /lib/tls/i686/cmov/libc.so.6
[...]
(gdb) info shared
From        To          Syms Read   Shared Object Library
0xb7f520e0  0xb7f5ea74  Yes         /lib/libbz2.so.1.0
0xb7767f40  0xb7c57880  Yes         /opt/qt/x86/qt3/lib/libqt-mt.so.3
0xb74f1660  0xb74fb174  Yes         /usr/lib/libXext.so.6
0xb7417c40  0xb74a54f4  Yes         /usr/lib/libX11.so.6
[...]


> It usually helps to install the Debian libc6-dbg package and configure
> your GDB with --prefix=/usr.  That will improve backtraces through the
> system libraries.

Sounds interresing... But I am currently testing a lot of gdb stuff here 
and don't want to interfere with my colleagues who work on the same 
machine, so I don't want to use --prefix=/usr ...

cu
Markus Grunwald