Heads up for login managers

[David Zeuthen]

On Mon, 2007-02-12 at 15:01 -0500, Steve Grubb wrote:
> On Monday 12 February 2007 14:42, Bill Nottingham wrote:
> > > So could UID. All you need is a unique identifier for each session. UID
> > > can do that. Whatever you use, it has to be auditable.
> >
> > UID isn't unique among sessions.
> 
> Is it a requirement for a user to log in multiple times? Where are the actual 
> requirements for this subsystem? The wiki page talks about problems, but not 
> what its supposed to allow. The wiki page it references talks about switching 
> between users.

Yes it is. If we ever want to be serious about multi-seat, or a lot more
interesting, thin client computing a'la Sun Ray (including session
migration) it's a requirement to be able to support this. 

I'm also a huge proponent of designing systems with artificial limits.
Only allowing one login per system is a fundamentally bad idea. Still, I
don't see what the fuss is about - XDG_SESSION_COOKIE works well, I just
wish the damn kernel would allow me to tag processes like I outlined
earlier.

      David