Subject: Re: kauth and sched_{get,set}param
To: Elad Efrat <elad@NetBSD.org>
From: David Laight <david@l8s.co.uk>
List: current-users
Date: 02/01/2008 18:21:51
On Fri, Feb 01, 2008 at 04:23:14PM +0200, Elad Efrat wrote:
> 
> That said, the call to the kauth authorization wrapper is still done
> with p_smutex held. For example in sys__sched_setparam(), the logic is
> 
> 	p = p_find(pid, PFIND_UNLOCK_FAIL);
> 	mutex_enter(&p->p_smutex);
> 	mutex_exit(&proclist_lock);
> 
> so I don't see how we can call kauth with p without having either
> proclist_list or p_smutex held.

It is likely to be almost impossible to ever have a kernel where
the kauth functions are allowed to sleep.
Not least because many of the check have to be atomic wrt data that
other threads/processes can change.

	David

-- 
David Laight: david@l8s.co.uk