Re: [PATCH 7/8] job control: Notify the real parent of job control events regardless of ptrace

[Oleg Nesterov <oleg@redhat.com>]

On 03/22, Tejun Heo wrote:
>
> On Mon, Mar 21, 2011 at 06:43:06PM +0100, Oleg Nesterov wrote:
> > Hmm... in fact I can't convince myself we really need to look at
> > child->group_leader, will recheck... Anyway, this is minor too.
>
> Care to elaborate?

child->real_parent must be equal to child->group_leader->real_parent.

What we need is ptrace_reparented(). But as I said, it should be
fixed first (I think) and this needs a separate patch/discussion.

So yes, we need a new helper.

Well, and look at get_signal_to_deliver(),

		leader = current->group_leader;
		if (task_ptrace(leader) && !real_parent_is_ptracer(leader))
			do_notify_parent_cldstop(leader, true, why);

Indeed. But in fact task_ptrace(leader) is not needed. If
real_parent_is_ptracer(tsk) returns false, then tsk must be ptraced.

So we could write

		if (!real_parent_is_ptracer(leader))
			do_notify_parent_cldstop(leader, true, why);

but now this looks confusing because of the naming. Compare with

		if (ptrace_reparented(leader))
			do_notify_parent_cldstop(leader);

Oleg.