diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 3a02503b3637..76cc25bc140d 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -291,9 +291,11 @@ struct tc_skb_ext {
  #endif
diff --git a/include/linux/stddef.h b/include/linux/stddef.h
index 998a4ba28eba..938216f8ab7e 100644
--- a/include/linux/stddef.h
+++ b/include/linux/stddef.h
@@ -36,4 +36,52 @@ enum {
  #define offsetofend(TYPE, MEMBER) \
  	(offsetof(TYPE, MEMBER)	+ sizeof_field(TYPE, MEMBER))
diff --git a/include/uapi/linux/stddef.h b/include/uapi/linux/stddef.h
index ee8220f8dcf5..22aa0e2177ea 100644
--- a/include/uapi/linux/stddef.h
+++ b/include/uapi/linux/stddef.h
@@ -4,3 +4,41 @@
  #ifndef __always_inline
  #define __always_inline inline
  #endif
+
+/**
+ * __struct_group() - Create a mirrored named and anonyomous struct
+ *
+ * @TAG: The tag name for the named sub-struct (usually empty)
+ * @NAME: The identifier name of the mirrored sub-struct
+ * @ATTRS: Any struct attributes (usually empty)
+ * @MEMBERS: The member declarations for the mirrored structs
+ *
+ * Used to create an anonymous union of two structs with identical layout
+ * and size: one anonymous and one named. The former's members can be used
+ * normally without sub-struct naming, and the latter can be used to
+ * reason about the start, end, and size of the group of struct members.
+ * The named struct can also be explicitly tagged for layer reuse, as well
+ * as both having struct attributes appended.
+ */
+#define __struct_group(TAG, NAME, ATTRS, MEMBERS...) \
+	union { \
+		struct { MEMBERS } ATTRS; \
+		struct TAG { MEMBERS } ATTRS NAME; \
+	}
+
+/**
+ * __DECLARE_FLEX_ARRAY() - Declare a flexible array usable in a union
+ *
+ * @TYPE: The type of each flexible array element
+ * @NAME: The name of the flexible array member
+ *
+ * In order to have a flexible array member in a union or alone in a
+ * struct, it needs to be wrapped in an anonymous struct with at least 1
+ * named member, but that member can be empty.
+ */
+#define __DECLARE_FLEX_ARRAY(TYPE, NAME)	\
+	struct { \
+		struct { } __empty_ ## NAME; \
+		TYPE NAME[]; \
+	}
+