[Intel-gfx] [PATCH] drm_calloc_large: check right size, check integer overflow, use GFP_ZERO

[Jesse Barnes]

On Mon,  8 Jun 2009 11:50:41 -0400
Kristian Høgsberg <krh at bitplanet.net> wrote:

> From: Kristian Høgsberg <krh at redhat.com>
> 
> Previously we would check size instead of size * nmemb, and so would
> never hit the vmalloc path.  Also add integer overflow check as in
> kcalloc, and allocate GFP_ZERO pages instead of memset()ing them.
> 
> Signed-off-by: Kristian Høgsberg <krh at redhat.com>
> ---
> 
> Oops...
> 
>  include/drm/drmP.h |   12 ++++--------
>  1 files changed, 4 insertions(+), 8 deletions(-)
> 
> diff --git a/include/drm/drmP.h b/include/drm/drmP.h
> index b84d8ae..4660e46 100644
> --- a/include/drm/drmP.h
> +++ b/include/drm/drmP.h
> @@ -1522,18 +1522,14 @@ static __inline__ void *drm_calloc(size_t
> nmemb, size_t size, int area) 
>  static __inline__ void *drm_calloc_large(size_t nmemb, size_t size)
>  {
> -	u8 *addr;
> -
> -	if (size <= PAGE_SIZE)
> +	if (size * nmemb <= PAGE_SIZE)
>  	    return kcalloc(nmemb, size, GFP_KERNEL);
>  
> -	addr = vmalloc(nmemb * size);
> -	if (!addr)
> +	if (size != 0 && nmemb > ULONG_MAX / size)
>  		return NULL;
>  
> -	memset(addr, 0, nmemb * size);
> -
> -	return addr;
> +	return __vmalloc(size * nmemb,
> +			 GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO,
> PAGE_KERNEL); }
>  
>  static __inline void drm_free_large(void *ptr)

I fail at calloc.  Thanks Kristian.  Now has someone actually tested
and found that this removes the "order N allocation failure" messages
from their logs this time?

Acked-by: Jesse Barnes <jbarnes at virtuousgeek.org>