[PATCH] signal: Avoid corrupting si_pid and si_uid in do_notify_parent

[Oleg Nesterov]

On 04/21, Oleg Nesterov wrote:
>
> The corner case is release_task() when the last exiting sub-thread sends
> a signal on behalf of its ->group_leader, and at this point all the tsk's
> pid pointers are NULL, that is why "force" can be falsely "true".

Or do_notify_parent() can be called by debugger from the parent namespace,
in this case "force" can be falsely "true" too.

Oleg.