Re: Where is RLIMIT_RT_CPU?

From: Arjan van de Ven
Date: Sat Jul 15 2006 - 10:47:30 EST


On Sun, 2006-07-16 at 00:19 +1000, Jean-Marc Valin wrote:
> > Non-root RT tasks are not "unprivileged" - they have a level of
> > privileges between a normal user and root. Really I think it's OK for
> > these tasks to consume 100% CPU, as the admin has explicitly allowed it.
>
> Sure, if the admin has allowed it, but I think it's also OK for desktop
> users to have access to rt scheduling by default, as long as their tasks
> are "well-behaved" (i.e. only use a few percent CPU).
>
> > The only problem is that Ubuntu shipped with this enabled for everyone.
>
> The problem is not the fact that it's enabled, but the fact that the
> amount of CPU allowed isn't restricted.

as long as you can fork and exec as many of those processes as you want
a per process rlimit is useless security wise... an evil user just fires
off a second process just before the first one gets killed and a non-RT
root still is starved out.


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