Re: [PATCH] vmwgfx: Use kcalloc instead of kzalloc to allocate array

[Jakob Bornecrantz <jakob@vmware.com>]

Reviewed-by: Jakob Bornecrantz <jakob@vmware.com>

----- Original Message -----
> The advantage of kcalloc is, that will prevent integer overflows
> which could result from the multiplication of number of elements
> and size and it is also a bit nicer to read.
> 
> The semantic patch that makes this change is available
> in https://lkml.org/lkml/2011/11/25/107
> 
> Signed-off-by: Thomas Meyer <thomas@m3y3r.de>
> ---
> 
> diff -u -p a/drivers/gpu/drm/vmwgfx/vmwgfx_ioctl.c
> b/drivers/gpu/drm/vmwgfx/vmwgfx_ioctl.c
> --- a/drivers/gpu/drm/vmwgfx/vmwgfx_ioctl.c 2011-11-13
> 11:07:24.343455126 +0100
> +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_ioctl.c 2011-11-28
> 19:50:07.413502824 +0100
> @@ -140,7 +140,7 @@ int vmw_present_ioctl(struct drm_device
>  		goto out_clips;
>  	}
>  
> -	clips = kzalloc(num_clips * sizeof(*clips), GFP_KERNEL);
> +	clips = kcalloc(num_clips, sizeof(*clips), GFP_KERNEL);
>  	if (clips == NULL) {
>  		DRM_ERROR("Failed to allocate clip rect list.\n");
>  		ret = -ENOMEM;
> @@ -232,7 +232,7 @@ int vmw_present_readback_ioctl(struct dr
>  		goto out_clips;
>  	}
>  
> -	clips = kzalloc(num_clips * sizeof(*clips), GFP_KERNEL);
> +	clips = kcalloc(num_clips, sizeof(*clips), GFP_KERNEL);
>  	if (clips == NULL) {
>  		DRM_ERROR("Failed to allocate clip rect list.\n");
>  		ret = -ENOMEM;