Re: examining a core dump on a machine with other base addresses in shared libraries

[Paul Pluzhnikov <ppluzhnikov@google.com>]

On Wed, May 27, 2009 at 1:52 PM, Drago Krznaric <drago.krznaric@spray.se> wrote:

> I have a program and a core dump created on machine A that I copy to
> machine B. I can open the core dump and get a nice backtrace on A but
> not on B. The reason appears to be that the shared libraries on A and B
> have different base addresses. They are otherwise exactly identical in
> hardware and software (RedHat 4).

Are you absolutely sure the libc binaries are identical between A and B?
We see a lot of similar GDB failures due to mismatch between libc versions
(but we don't use prelink).

You could verify whether prelink is the problem, by copying B:libc.so.6 and
B:ld-linux.so.2 to e.g. /tmp/lib, manually prelinking them to the same
address A:libc.so.6 and A:ld-linux.so.2 were prelinked at, and verifying
they "work" (set solib-absolute-prefix /tmp in GDB before loading the core).

I think you should also get identical (as in md5sum-identical) binary
for B:/tmp/lib/libc.so.6 and A:/lib/libc.so.6

Cheers,
-- 
Paul Pluzhnikov