Hi, On Mon, Apr 11, 2005 at 02:07:47PM +0100, Mike Hearn wrote: > On Sun, 2005-04-10 at 19:42 -0500, Robert Shearman wrote: > > You're forgetting the reason why we need the suid root binary - > > because allowing processes to set their priority as realtime (or > > otherwise very high) leaves the system open to a trvial DoS attack. > > Not only do the startup code paths need to be audited, but also the > > priority setting logic too. > > Good point. But I don't think there's any way to avoid this: > fundamentally anyone can write a Win32 app that requests realtime > priority and then goes into an infinite loop. In order to emulate that > faithfully Linux just has to budge. Nope, that's just the main issue of what the CK kernel discussed: how to implement some sort of "realtime" priority *without* DoS capabilities. And the result was SCHED_ISO.
See http://bhhdoa.org.au/pipermail/ck/2004-October/001169.html for an overview. But OTOH your point is still valid: even a SCHED_ISO wouldn't emulate this kind of realtime priority correctly, since it *can* be preempted, which would probably violate Win32 realtime prio properties. Still, it's a very acceptable compromise, I'd say. > It's not like it's hard to DoS a desktop Linux box anyway. Just compile > winetest on it ;) <duck> Now that's true ;) Andreas
