On Wed, 13 Jun 2001, Andrew Brown wrote:

> ps axw | awk '/X/{print"kill -9",$1}' | sh
>
> but can i, as a regular user, kill my own x server?  what about one
> started by xdm?

I don't think so. But then, that's not really the point. The aperture
driver is presumably only useable by root anyway (why would it be
read/writeable by anyone else if X is run as root?), so the issue here is
using the aperture driver to circumvent the usual protection from writing
kernel memory. If you use the DMA engine on the graphics card to write
kernel memory, you can do pretty much anything... even insert malicious
code into the kernel, which is certainly not something you want if you're
running at securelevel 1 or above.

-- 
Gillette - the best a man can forget