diff --git a/include/linux/string.h b/include/linux/string.h
index efdc445..810d80d 100644
--- a/include/linux/string.h
+++ b/include/linux/string.h
@@ -111,5 +111,8 @@
 
 extern bool sysfs_streq(const char *s1, const char *s2);
 
+extern ssize_t memory_read_from_buffer(void *to, size_t count, loff_t *ppos,
+			const void *from, size_t available);
+
 #endif
 #endif /* _LINUX_STRING_H_ */