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Date: Tue, 25 Mar 2003 08:58:02 -0500
From: Daniel Jacobowitz <dan@debian.org>
To: Werner Almesberger <wa@almesberger.net>
Cc: raj <raj@cs.wisc.edu>, linux-kernel@vger.kernel.org, zandy@cs.wisc.edu
Subject: Re: [PATCH] ptrace on stopped processes (2.4)
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On Tue, Mar 25, 2003 at 10:48:42AM -0300, Werner Almesberger wrote:
> Daniel Jacobowitz wrote:
> > No, that's not what I meant.  When you attach using GDB, there is no
> > way for GDB to determine if the process was previously stopped or
> > running.
> 
> Likewise, there's a race condition with any other concurrent use
> of SIGSTOP.
> 
> Perhaps one could introduce a PTRACE_ATTACH2 that uses "addr" to
> indicate the signal that should be used to sychronize attaching.
> That way, programs that use STOP/CONT for their own purposes could
> be attached to with ptrace(PTRACE_ATTACH2,pid,SIGTRAP,0), or such.
> 
> If the process is already stopped, the debugger would be notified
> with WSTOPSIG set to that signal instead of SIGTRAP.

Have you got an example that needs this?  I'm not terribly concerned;
GDB's handling of SIGSTOP has always been pretty bad.  Strace is a bit
better.

-- 
Daniel Jacobowitz
MontaVista Software                         Debian GNU/Linux Developer
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