[PATCH] slab: introduce kmem_cache_zalloc allocator
Introduce a memory-zeroing variant of kmem_cache_alloc. The allocator
already exits in XFS and there are potential users for it so this patch
makes the allocator available for the general public.
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/mm/slab.c b/mm/slab.c
index a504716..6f5aeeb 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -3108,6 +3108,23 @@
EXPORT_SYMBOL(kmem_cache_alloc);
/**
+ * kmem_cache_alloc - Allocate an object. The memory is set to zero.
+ * @cache: The cache to allocate from.
+ * @flags: See kmalloc().
+ *
+ * Allocate an object from this cache and set the allocated memory to zero.
+ * The flags are only relevant if the cache has no available objects.
+ */
+void *kmem_cache_zalloc(struct kmem_cache *cache, gfp_t flags)
+{
+ void *ret = __cache_alloc(cache, flags, __builtin_return_address(0));
+ if (ret)
+ memset(ret, 0, obj_size(cache));
+ return ret;
+}
+EXPORT_SYMBOL(kmem_cache_zalloc);
+
+/**
* kmem_ptr_validate - check if an untrusted pointer might
* be a slab entry.
* @cachep: the cache we're checking against