linux/include/drm/drm_mem_util.h
Xi Wang a3860c1c5d introduce SIZE_MAX
ULONG_MAX is often used to check for integer overflow when calculating
allocation size.  While ULONG_MAX happens to work on most systems, there
is no guarantee that `size_t' must be the same size as `long'.

This patch introduces SIZE_MAX, the maximum value of `size_t', to improve
portability and readability for allocation size validation.

Signed-off-by: Xi Wang <xi.wang@gmail.com>
Acked-by: Alex Elder <elder@dreamhost.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Pekka Enberg <penberg@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-05-31 17:49:26 -07:00

65 lines
2 KiB
C

/*
* Copyright © 2008 Intel Corporation
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice (including the next
* paragraph) shall be included in all copies or substantial portions of the
* Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
* IN THE SOFTWARE.
*
* Authors:
* Jesse Barnes <jbarnes@virtuousgeek.org>
*
*/
#ifndef _DRM_MEM_UTIL_H_
#define _DRM_MEM_UTIL_H_
#include <linux/vmalloc.h>
static __inline__ void *drm_calloc_large(size_t nmemb, size_t size)
{
if (size != 0 && nmemb > SIZE_MAX / size)
return NULL;
if (size * nmemb <= PAGE_SIZE)
return kcalloc(nmemb, size, GFP_KERNEL);
return __vmalloc(size * nmemb,
GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO, PAGE_KERNEL);
}
/* Modeled after cairo's malloc_ab, it's like calloc but without the zeroing. */
static __inline__ void *drm_malloc_ab(size_t nmemb, size_t size)
{
if (size != 0 && nmemb > SIZE_MAX / size)
return NULL;
if (size * nmemb <= PAGE_SIZE)
return kmalloc(nmemb * size, GFP_KERNEL);
return __vmalloc(size * nmemb,
GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL);
}
static __inline void drm_free_large(void *ptr)
{
if (!is_vmalloc_addr(ptr))
return kfree(ptr);
vfree(ptr);
}
#endif