Re: gdbserver multithreaded debugging

Re: gdbserver multithreaded debugging

[olivier.carmona@ieee.org]

Thanks Daniel and Lim.

Here are more information as requested:

We are using:
GLIBC 2.3.3
Thread : LinuxThread 0.10
GDB 6.3

When we set the breakpoint in the main thread: program is
running correctly and we can watch the main program.

But as soon as we set the breakpoint in a thread, gdb server
terminates with a signal "Killing inferior" and stops,
whereas gdb stops printing the following message:
 "Program terminated with signal SIGKILL, Killed".
 "The program no longer exists."
At this point, of course, when we do a backtrace in gdb, we
got a corrupted stack.

We checked hat all shared libraries exists on target and are
loaded correctly. Moreover, libthread_db.so exists on the
target side and we tried copying on the local host using set
solib-absolute-prefix.

We have a slight difference between a GDB 6.3 2005.3.17 and
a GDB 6.3.50, the only difference is that gdb prints the
following message in place:
" Program received signal SIGSEGV, Segmentation fault."
"0x00000000 in ?? ()"

Olivier Carmona

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Re: gdbserver multithreaded debugging

[Daniel Jacobowitz]

On Tue, Oct 18, 2005 at 03:08:16PM +0200, olivier.carmona@ieee.org wrote:
> Dear All,
> 
> I am trying to use gdbserver to remotely debug a
> multithreaded application.
> 
> Target is a ARM9, running Linux v2.6.10; gdbserver from the
> 6.3 release tarball and built on local host.
> 
> Local host is a Pentium IV, running Fedora Core 3, gdb v 6.3.
> 
> I get a SIGKILL as soon as a thread starts, execution stops
> on gdb side, and on gdbserver side it also stops showing a
> Terminated: Killing Inferior.

You should figure out where the SIGKILL comes from, first.

-- 
Daniel Jacobowitz
CodeSourcery, LLC

gdbserver multithreaded debugging

[olivier.carmona@ieee.org]

Dear All,

I am trying to use gdbserver to remotely debug a
multithreaded application.

Target is a ARM9, running Linux v2.6.10; gdbserver from the
6.3 release tarball and built on local host.

Local host is a Pentium IV, running Fedora Core 3, gdb v 6.3.

I get a SIGKILL as soon as a thread starts, execution stops
on gdb side, and on gdbserver side it also stops showing a
Terminated: Killing Inferior.

We tried a few things:

- we forced to ignore the SIGKILL and/or the SIG32 signals,

- we forced loading the symbol from shared library on the
host side (thanks to solib-absolute-prefix and
solib-search-path, library copied: libpthread, ldlinux, libc),

- we forced loading a local copy of libthread_db.so (using
also solib-absolute-prefix and solib-search-path),

...,but nonetheless we got not solution.

I don't see this problem while debugging in
non-multithreaded application.

Is there anything I can do to solve the problem I am
experiencing with gdbserver?

__
Olivier Carmona





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