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@asuffield said:@Thief^ said:Windows 98 was actually spectacularly stable given that an application crashing could kill windows (only drivers have that privelidge in XP). Correction: in XP, drivers, any program that uses DirectX, any program that uses OpenGL, and any program running as an administrator or power user (if you count the scores of unfixed local exploits - Microsoft only release security patches for remote exploits and things that are generating bad press attention) can kill windows.The easiest way is usually to muck around with the video card. They can crash the hardware, so hard that not even the power button works any more, if you render the right kinds of nonsense - it's so easy to do that it happens from time to time just when debugging regular 3d code. It's important to realise that your video card can be programmed both to write to system memory and to abuse the PCI bus; unfettered access to the video card is just as good as running in kernel space, and neither the ATI nor nVidia drivers have any kind of security in place (since that would reduce framerates).
I'm not sure if nVidia cards can put any security in place very easily. As I understand it, they're designed to allow user programs to submit commands directly to the graphics card (via one of 32 or so memory-mapped command FIFOs). In fact, the nVidia driver apparently uses said FIFOs to call from userspace into the in-kernel driver by submitting a command that generates an interrupt.