[Devel] [RFC][PATCH] Add child reaper to struct pspace

[Eric W. Biederman]

Kirill Korotaev <dev at sw.ru> writes:

> Cedric Le Goater wrote:
>> Sukadev Bhattiprolu wrote:
>> 
>> <snip>
>> 
>>>@@ -620,8 +620,8 @@ static int de_thread(struct task_struct 
>>> 	 * Reparenting needs write_lock on tasklist_lock,
>>> 	 * so it is safe to do it under read_lock.
>>> 	 */
>>>-	if (unlikely(current->group_leader == child_reaper))
>>>-		child_reaper = current;
>>>+	if (unlikely(current->group->leader == current->pspace->child_reaper)
>>>+		current->pspace->child_reaper = current;
>>> 
>>> 	zap_other_threads(current);
>>> 	read_unlock(&tasklist_lock);
>> 
>> 
>> I'm unsure about this one ?
> AFAICS, this one is for multithreaded init?
> looks ok, imho.

Correct except for the lack of nsproxy.

The case to think about is when a multi-threaded init exec a
process for a thread where pid != tgid.

It prevents from having problems with an untrusted init process.


Eric