[Linux-fbdev-devel] Re: atyfb in 2.5.51

[Geert U. <ge...@li...>]

On 13 Dec 2002, Alan Cox wrote:
> On Fri, 2002-12-13 at 08:53, Geert Uytterhoeven wrote:
> > (At first I thought you meant an instruction where the opcode crosses those
> >  two memory types, but we don't put code in video RAM...)
> 
> I did. The frame buffer drivers support mmap(). x86 has no "non-exec"
> bit. So any user able to open /dev/fb can bring down such a box. Similar
> things apply with early athlon and prefetching /dev/fb

Weird... So it really crashes the box, not just throwing an exception?
On PPC you cannot use prefetching on non-cached memory, but if you try it won't
take down the whole box.

Then make sure /dev/fb is accessible by `trusted' users on such machines.

Gr{oetje,eeting}s,

						Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- ge...@li...

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
							    -- Linus Torvalds