Re: Debugging and NPTL

[Ali Ijaz Sheikh <ali binish com>]

Quoting Daniel Jacobowitz <drow false org>:

> On Mon, May 17, 2004 at 03:11:45PM -0400, Ali Ijaz Sheikh wrote:
> >
> > Hi,
> >
> > I have recently started seeing some problems with debugging of
> multithreaded
> > applications with NPTL on 2.6 series kernels.  It seems that GDB is no
> longer
> > being informed of the events occurring in the child threads because
> > create_thread (nptl/sysdeps/pthread/create_thread.c) routine does not pass
> the
> > CLONE_PTRACE flag to the clone system call.  For example, if the child
> thread
> > gets a SEGV, the whole thread group is terminated without GDB ever being
> told.
> >
> > When creating a thread in a thread group that is being ptraced, shouldn't
> the
> > child thread be created with a CLONE_PTRACE?  It this a nptl bug?  Or is
> this
> > GDB's fault?
> >
> > A simple program that creates a thread and does raise(SIGSEGV) in the child
> > thread can be used to reproduce this problem.  Try running that in gdb.
>
> No, it should not be using CLONE_PTRACE.  You didn't say what version
> of GDB you were using; you may want to try a newer one.
>
> --
> Daniel Jacobowitz
>

I have tried this with GDB 6.0 and 6.1.

-Ali