Re: [PATCH] ptrace on stopped processes (2.4)

Daniel Jacobowitz
2003-03-25T13:48:54Z

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