[PATCH RFC v2] slab: introduce kmalloc_array

From: Xi Wang
Date: Thu Feb 09 2012 - 08:48:37 EST


This patch introduces a kmalloc_array() wrapper that performs integer
overflow checking without zeroing the memory.

Suggested-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Suggested-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Xi Wang <xi.wang@xxxxxxxxx>
---
Let's take "kxnalloc" off for now and keep the patch simple.
---
include/linux/slab.h | 17 ++++++++++++++---
1 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/include/linux/slab.h b/include/linux/slab.h
index 573c809..a595dce 100644
--- a/include/linux/slab.h
+++ b/include/linux/slab.h
@@ -190,7 +190,7 @@ size_t ksize(const void *);
#endif

/**
- * kcalloc - allocate memory for an array. The memory is set to zero.
+ * kmalloc_array - allocate memory for an array.
* @n: number of elements.
* @size: element size.
* @flags: the type of memory to allocate.
@@ -240,11 +240,22 @@ size_t ksize(const void *);
* for general use, and so are not documented here. For a full list of
* potential flags, always refer to linux/gfp.h.
*/
-static inline void *kcalloc(size_t n, size_t size, gfp_t flags)
+static inline void *kmalloc_array(size_t n, size_t size, gfp_t flags)
{
if (size != 0 && n > ULONG_MAX / size)
return NULL;
- return __kmalloc(n * size, flags | __GFP_ZERO);
+ return __kmalloc(n * size, flags);
+}
+
+/**
+ * kcalloc - allocate memory for an array. The memory is set to zero.
+ * @n: number of elements.
+ * @size: element size.
+ * @flags: the type of memory to allocate (see kmalloc).
+ */
+static inline void *kcalloc(size_t n, size_t size, gfp_t flags)
+{
+ return kmalloc_array(n, size, flags | __GFP_ZERO);
}

#if !defined(CONFIG_NUMA) && !defined(CONFIG_SLOB)
--
1.7.5.4

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