[RFC][PATCH] Use task_pgrp()/task_session() in copy_process

[Eric W. Biederman]

ebiederm at xmission.com (Eric W. Biederman) writes:
>
> So it probably makes sense for pidmap_init to initialize the
> pid for the session and group of the idle task.  And then there
> are no special cases left.

Well that almost works except if we did that alloc_pid could not
successfully allocate pid 1.  Grumble getting those special cases
out of the boot path is a pain.  

If we had a non-hashed struct pid (init_pid?) that we filled in
early (statically?), that would keep copy_process happy.

Then we would need to call setsid() in the kernel right after
the fork to assign a legitimate session and process group
to pid == 1.

Since the idle thread is not doing anything it shouldn't matter,
although we can attach the idle thread after the fork to session
and process group == 1 or set them to NULL if there is a corner case
is anything that cares.  

Eric