mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-12-11 21:14:07 +08:00
a3860c1c5d
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>
66 lines
2.0 KiB
C
66 lines
2.0 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
|