Shared libaries and core files

Shared libaries and core files

[Worley, Dale R (Dale)]

I see that when I give GDB a core file, GDB loads many shared
libraries into its memory model of the process being debugged.  How
does GDB determine what these libraries are?  Does GDB know of
libraries that are loaded "dynamically" in the course of execution, or
only those that are loaded at process start time?

Naively, I would expect the dynamic loading routines in the process
would have to keep track of all the loaded libraries, and GDB could
extract from these data structures the complete list of libraries that
were loaded at the moment of the process failure.

Any information would be helpful,

Dale

Re: Shared libaries and core files

[Pedro Alves]

On Friday 04 November 2011 18:02:21, Worley, Dale R (Dale) wrote:
> I see that when I give GDB a core file, GDB loads many shared
> libraries into its memory model of the process being debugged.  How
> does GDB determine what these libraries are?  Does GDB know of
> libraries that are loaded "dynamically" in the course of execution, or
> only those that are loaded at process start time?

The former.

> Naively, I would expect the dynamic loading routines in the process
> would have to keep track of all the loaded libraries, and GDB could
> extract from these data structures the complete list of libraries that
> were loaded at the moment of the process failure.

Correct.

-- 
Pedro Alves

RE: Shared libaries and core files

[Worley, Dale R (Dale)]

> From: Pedro Alves [pedro@codesourcery.com]
> 
> > Naively, I would expect the dynamic loading routines in the process
> > would have to keep track of all the loaded libraries, and GDB could
> > extract from these data structures the complete list of libraries that
> > were loaded at the moment of the process failure.
> 
> Correct.

That is good to learn.  Is there any simple way, given a core file, to
extract an explicit list of loaded libraries?

Dale

Re: Shared libaries and core files

[Pedro Alves]

On Friday 04 November 2011 19:23:34, Worley, Dale R (Dale) wrote:

> Is there any simple way, given a core file, to extract an
> explicit list of loaded libraries?

What's "explicit"?

$ gdb /path/to/program -c /path/to/core
(gdb) info sharedlibrary

Or were you thinking of something else?

-- 
Pedro Alves

RE: Shared libaries and core files

[Worley, Dale R (Dale)]

i> From: Pedro Alves [pedro@codesourcery.com]
> 
> $ gdb /path/to/program -c /path/to/core
> (gdb) info sharedlibrary
> 
> Or were you thinking of something else?

I wasn't aware of "info sharedlibrary".

What I want is something that can be done from the command line.  It
looks like

gdb [executable] -c [core] -silent -ex 'info sharedlibrary' -ex quit

will suffice.  The output from that can be postprocessed to make a
list of the libraries.

Thanks!

Dale