new file mode 100644
@@ -0,0 +1,25 @@
+#ifndef __BACKPORT_LINUX_STRING_H
+#define __BACKPORT_LINUX_STRING_H
+#include_next <linux/string.h>
+
+#ifndef memset_after
+#define memset_after(obj, v, member) \
+({ \
+ u8 *__ptr = (u8 *)(obj); \
+ typeof(v) __val = (v); \
+ memset(__ptr + offsetofend(typeof(*(obj)), member), __val, \
+ sizeof(*(obj)) - offsetofend(typeof(*(obj)), member)); \
+})
+#endif
+
+#ifndef memset_startat
+#define memset_startat(obj, v, member) \
+({ \
+ u8 *__ptr = (u8 *)(obj); \
+ typeof(v) __val = (v); \
+ memset(__ptr + offsetof(typeof(*(obj)), member), __val, \
+ sizeof(*(obj)) - offsetof(typeof(*(obj)), member)); \
+})
+#endif
+
+#endif /* __BACKPORT_LINUX_STRING_H */