diff --git a/include/linux/overflow.h b/include/linux/overflow.h
index 659045046468..93fcef105061 100644
--- a/include/linux/overflow.h
+++ b/include/linux/overflow.h
@@ -304,16 +304,33 @@ static inline __must_check size_t __ab_c_size(size_t a, size_t b, size_t c)
  * struct_size() - Calculate size of structure with trailing array.
  * @p: Pointer to the structure.
  * @member: Name of the array member.
- * @n: Number of elements in the array.
+ * @count: Number of elements in the array.
  *
  * Calculates size of memory needed for structure @p followed by an
- * array of @n @member elements.
+ * array of @count number of @member elements.
  *
  * Return: number of bytes needed or SIZE_MAX on overflow.
  */
-#define struct_size(p, member, n)					\
-	__ab_c_size(n,							\
+#define struct_size(p, member, count)					\
+	__ab_c_size(count,						\
 		    sizeof(*(p)->member) + __must_be_array((p)->member),\
 		    sizeof(*(p)))
 
+/**
+ * flex_array_size() - Calculate size of a flexible array member
+ *                     within an enclosing structure.
+ *
+ * @p: Pointer to the structure.
+ * @member: Name of the flexible array member.
+ * @count: Number of elements in the array.
+ *
+ * Calculates size of a flexible array of @count number of @member
+ * elements, at the end of structure @p.
+ *
+ * Return: number of bytes needed or SIZE_MAX on overflow.
+ */
+#define flex_array_size(p, member, count)				\
+	array_size(count,						\
+		    sizeof(*(p)->member) + __must_be_array((p)->member))
+
 #endif /* __LINUX_OVERFLOW_H */