Re: GDB server and threaded application

[Kalpesh Jasapara <kjasapara at yahoo dot com>]

Hello Daniel,

I believe I have the solib path set correctly and
all the symbols are being loaded when I connect
to the remote target.

BTW I am able to debug core files correctly and the
core files show all the threads. Its an issue if
I try to attach to a running multithreaded process.

gdbserver :12345 --attach <PID>, I just pick up one
of the PID's of the multithreaded process. I guess 
this is supported.

Thanks for all the information. 
-Kalpesh

--- Daniel Jacobowitz <drow at mvista dot com> wrote:
> On Tue, Mar 25, 2003 at 09:39:01PM -0800, Vladimir
> Gurevich wrote:
> > Hi Kalpesh!
> > 
> > Kalpesh Jasapara wrote:
> > >I am having a problem with remote gdb debugging
> > >using gdbserver to work with multi threads.
> > >The command "info threads" shows only one thread.
> > 
> > Here is a relevant excerpt from Wolfgang Denk's
> > posting from ppc-embedded:
> 
> As usual, Wolfgang's answer is somewhat biased.  GDB
> 5.3's
> multithreaded debug support is complete, and works
> very well once you
> have it set up.  The only thing missing in the FSF
> tree is the little
> "[New thread 21211]" messages, which are purely
> cosmetic; I never came
> to an agreement about how to implement them in the
> current protocol.
> 
> Neither the version originally in HHL 2.0 nor gdb
> 5.2.1 supported it
> however.  Kalpesh said he was trying gdb 5.3, which
> does.
> 
> I would also like to offer Wolfgang a BIG KICK IN
> THE HEAD.  I have
> looked at the relevant path on his FTP site that you
> referenced below;
> despite his name as the only name on the "ChangeLog
> entry" in the
> README and the claim of "we spend some work", it is
> my work.  I wrote
> just about every line of that patch.
> 
> As usual proper credit would be appreciated.
> 
> > 
> > >Dear Owen,
> > >
> > >in message
> <20020820144703 dot 16442 dot qmail at web20107 dot mail dot yahoo dot com>
> you wrote:
> > >
> > >>
> > >>I`m trying to debug a multi-threaded application
> using
> > >>gdbserver on the remote/target side and I`m
> having
> > >>some problems, the output I got is depicted
> below:
> > >
> > >
> > >I'm not surprised. This is broken in most
> versions of GDB / gdbserver
> > >floating around.
> > >
> > >
> > >>I`m using gdbserver5.2.1 (I tried the one from
> HHL-2.0
> > >>Journeyman and didn`t worked too) compiled by
> myself
> > >>using Mvista HHL 2.0 tools and gdb 5.2.1 on my
> i386.
> > >>Am I doing something wrong or remote thread
> debugging
> > >>is not supported by gdb? I have read something
> about
> > >
> > >
> > >Let's say the support is incomplete :-)
> > >
> > >>problems with multi-thread application debugging
> but I
> > >>thought that it may be OK at this time...
> > >>Could someone explain to me what`s happening?
> > >
> > >
> > >Check out our ELDK  (see 
> http://www.denx.de/ELDK);  it  contains  an
> > >extended  /  bug  fixed  version  of  GDB  /
> gdbserver; remote target
> > >debugging of MT applications was one of the areas
> where we spend some
> > >work.
> > >
> > >If you're just looking for the patches: these can
> be found on our FTP
> > >server; the README including description of the
> test procedure is at
> >
>
>ftp://ftp.denx.de/pub/ppc/patches/README-GDB-MT-Support
> > >
> > 
> > I hope this helps.
> > 
> > Cheers,
> > Vladimir
> > 
> > 
> 
> -- 
> Daniel Jacobowitz
> MontaVista Software                         Debian
> GNU/Linux Developer


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