Re: [RFC] Small PCI core patch

[Jeff Garzik <jgarzik@pobox.com>]

Robert Hancock wrote:
> Jeff Garzik wrote:
> 
>> One sticking point is validation:  ensuring userspace cannot cause
>> invalid GPU microcode to be generated.  [I can just hear Al Viro
>> swearing, just thinking about creating secure compilers...]
> 
> 
> I suspect the amount of data going through is large enough that this 
> wouldn't really be practical. I think you'd have to deal with the code 
> generating GPU instructions having to be trusted and have the device 
> interface require root privileges..

All I said was "ensuring userspace cannot cause invalid GPU microcode to 
be generated."

No matter what runs with root priveleges, other graphics processes do 
not, and one must ensure that app clients cannot generate sequences 
which cause the hardware to fail.  Which is a lot more difficult, when 
the unpriveleged app clients are submitting GLSL.

	Jeff