Re: [PATCH v2 5/7] clone4: Add a CLONE_AUTOREAP flag to automatically reap the child process

[josh]

On Fri, Mar 20, 2015 at 08:09:14PM +0100, Oleg Nesterov wrote:
> On 03/20, Thiago Macieira wrote:
> >
> > On Friday 20 March 2015 19:14:04 Oleg Nesterov wrote:
> > > Also. I forgot that the kernel always resets ->exit_signal to SIGCHLD on
> > > exec or reparenting. Reparenting is probably fine. But what about exec?
> > > Should it keep ->exit_signal == 0 if "autoreap" ? I think it should not, to
> > > avoid the strange special case.
> >
> > Not delivering any signal was the objective of this patch series, so yes
> > exit_signal == 0 should survive an exec and even re-exec.
> 
> OK, but then perhaps we should never send SIGCHLD (on exit) if "autoreap",
> to make the logic simple.
> 
> And copy_process() should probably do
> 
> 	if ((clone_flags & CSIGNAL) && (clone_flags && CLONE_AUTOREAP))
> 		return -EINVAL;
> 
> so that we still can change this behaviour later.

I'm fine with that, as it would handle the particular use case we care
about.

However, the reset-signal-on-reparent thing might still make sense,
particularly for the ptrace-reparent case (less so for the
reparent-to-child-reaper case).

- Josh Triplett
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/