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Re: gdb: detection and/or fork+gethostbyname crash workaround?
On Tue, Jul 24, 2001 at 02:22:48PM -0400, Glenn F. Maynard wrote:
> On Tue, Jul 24, 2001 at 08:52:19AM -0700, Kevin Buettner wrote:
> > If it's one which uses ptrace(), the kernel usually prohibits two
> > processes from invoking ptrace() on the same inferior. So one
> > strategy might be to have the program in question cause ptrace to be
> > invoked on itself. I don't think the process will be able to do this
> > itself; I think it's likely that it would have to fork and let the
> > child attempt this. The return status from wait() or waitpid() could
> > indicate whether the attempt to invoke ptrace() was successful or not.
>
> That's what I tried (x86 Linux); a process can't ptrace itself. I could
> fork a process to test this, I suppose; I'll try that. (Wouldn't it
> be the return status from ptrace(), though? I assume it'd return something
> like EPERM if a process is already being debugged.)
Try ptrace( PTRACE_TRACEME, ...) ?
--
Daniel Jacobowitz Carnegie Mellon University
MontaVista Software Debian GNU/Linux Developer