Re: Does gdb 5.2 work with statically linked thread application under Linux?

[Daniel Jacobowitz <drow@mvista.com>]

On Thu, Mar 07, 2002 at 01:39:28PM -0800, H . J . Lu wrote:
> On Thu, Mar 07, 2002 at 02:48:41AM -0500, Daniel Jacobowitz wrote:
> > On Wed, Mar 06, 2002 at 11:30:50PM -0800, H . J . Lu wrote:
> > > Does gdb 5.2 work with statically linked thread application under
> > > Linux? It doesn't work for me at all. It doesn't know any thread.
> > > I have a patch which works for gdb 5.1. Now it doesn't work for 5.2
> > > anymore.
> > 
> > My fault, I think.
> > 
> > The problem is that in a dynamically linked binary
> > thread_db_new_objfile will be called for every library is loaded.  At
> > this point current_target is "child", so target_has_execution is true.
> > But with a static binary, the first time the function is called objfile
> > is NULL, and the second time current_target is "exec" (which has
> > target_has_execution set false).
> > 
> > Perhaps target_has_execution was not the right check after all, if
> > "exec" has it set false (which makes fairly little sense to me...) or
> > perhaps we need to call the hook again later.  Michael, any idea?
> > 
> 
> What is the problem if "|| !target_has_execution" is removed? I removed
> it. Gdb now works on statically linked thread application as well as
> core file. Did I miss soemthing?

Try running 'info threads' on the corefile of a multithreaded
application.  Recent Linux kernels will allow them to dump core.

I've also got a patch to put multiple threads into the corefile. 
There's a sample corefile at:
  http://crack.them.org/~drow/mtc2.tar.gz


Without !target_has_execution, we try to use lin-lwp on the coredump. 
That works very badly.

-- 
Daniel Jacobowitz                           Carnegie Mellon University
MontaVista Software                         Debian GNU/Linux Developer