GPU chips vs Video Cards

[Dave Feustel]

On Wed, Dec 24, 2008 at 08:39:47AM +1030, Tim wrote:
> On Tue, 2008-12-23 at 16:34 -0500, Dave Feustel wrote:
> > Various OpenBSD developers have stated that there are OS
> > vulnerabilities introduced by the use of video card hardware features
> > by X. It's been a while since I read the details, but I wonder if the
> > GPU chips might be able to run in user (non-priviledged) mode only,
> > thus precluding the possibility of exploits based upon direct hardware
> > access given the video card software.
> 
> Are you sure that's not just issues because of X, and maybe drivers, not
> the actual graphics cards, themselves? 

It is my impression that the security vulnerabilities associated with
the graphics cards stem from the abiltiy of the cards to access all of
memory using dma. The OpenBSD people said that the only way to avoid
this problem is to not allow X access to the video card.
 
> If anything, I'd expect more issues with GPUs, as they're not all just
> usable for graphics, some are usable as an additional CPU for other
> purposes.