[PATCH 1/6] mm: add kmalloc_array_node and kcalloc_node

[Johannes Thumshirn]

We have kmalloc_array() and kcalloc() wrappers on top of kmalloc() which
ensure us overflow free multiplication for the size of a memory
allocation but these implementations are not NUMA-aware.

Likewise we have kmalloc_node() which is a NUMA-aware version of
kmalloc() but the implementation is not aware of any possible overflows in
eventual size calculations.

Introduce a combination of the two above cases to have a NUMA-node aware
version of kmalloc_array() and kcalloc().

Signed-off-by: Johannes Thumshirn <jthumshirn@xxxxxxx>
---
 include/linux/slab.h | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/include/linux/slab.h b/include/linux/slab.h
index 41473df6dfb0..aaf4723e41b3 100644
--- a/include/linux/slab.h
+++ b/include/linux/slab.h
@@ -635,6 +635,22 @@ extern void *__kmalloc_track_caller(size_t, gfp_t, unsigned long);
 #define kmalloc_track_caller(size, flags) \
 	__kmalloc_track_caller(size, flags, _RET_IP_)
 
+static inline void *kmalloc_array_node(size_t n, size_t size, gfp_t flags,
+				       int node)
+{
+	if (size != 0 && n > SIZE_MAX / size)
+		return NULL;
+	if (__builtin_constant_p(n) && __builtin_constant_p(size))
+		return kmalloc_node(n * size, flags, node);
+	return __kmalloc_node(n * size, flags, node);
+}
+
+static inline void *kcalloc_node(size_t n, size_t size, gfp_t flags, int node)
+{
+	return kmalloc_array_node(n, size, flags | __GFP_ZERO, node);
+}
+
+
 #ifdef CONFIG_NUMA
 extern void *__kmalloc_node_track_caller(size_t, gfp_t, int, unsigned long);
 #define kmalloc_node_track_caller(size, flags, node) \
-- 
2.13.5