[021/121] slab: introduce kmalloc_array()

From: Ben Hutchings
Date: Sat Sep 07 2013 - 23:53:14 EST


3.2.51-rc1 review patch. If anyone has any objections, please let me know.

------------------

From: Xi Wang <xi.wang@xxxxxxxxx>

commit a8203725dfded5c1f79dca3368a4a273e24b59bb upstream.

Introduce 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>
Cc: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Acked-by: David Rientjes <rientjes@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Pekka Enberg <penberg@xxxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
include/linux/slab.h | 17 ++++++++++++++---
1 file 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)

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/