Re: [PATCH] Fix crash in viafb due to 4k stack overflow

[Arjan van de Ven]

On Sun, 9 Nov 2008 11:36:03 -0800
Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote:

> On Sun, 9 Nov 2008 20:25:37 +0100 Bruno Pr__mont
> <bonbons@xxxxxxxxxxxxxxxxx> wrote:
> 
> > The function viafb_cursor() uses 2 stack-variables of CURSOR_SIZE
> > bits; CURSOR_SIZE is defined as (8 * 1024). Using up twice 1k on
> > stack is too much for 4k-stack (though it works with 8k-stacks).
> 
> >  
> >  	if (viacursor.enable)
> 
> Is the ->fb_cursor handler allowed to perform GFP_KERNEL memory
> allocations?  It's never called from atomic contexts?

if it's allowed to do GFP_KERNEL memory allocations the statement that
it works with 8k stacks is a bit overstated... since irq's can come in
and take several KB of stack as well ;)

-- 
Arjan van de Ven 	Intel Open Source Technology Centre
For development, discussion and tips for power savings, 
visit http://www.lesswatts.org
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/