diff --git a/include/linux/usb/gadget.h b/include/linux/usb/gadget.h
index cf468fb..0ebedae 100644
--- a/include/linux/usb/gadget.h
+++ b/include/linux/usb/gadget.h
@@ -858,6 +858,25 @@
 int usb_gadget_config_buf(const struct usb_config_descriptor *config,
 	void *buf, unsigned buflen, const struct usb_descriptor_header **desc);
 
+/* copy a NULL-terminated vector of descriptors */
+struct usb_descriptor_header **usb_copy_descriptors(
+		struct usb_descriptor_header **);
+
+/* return copy of endpoint descriptor given original descriptor set */
+struct usb_endpoint_descriptor *usb_find_endpoint(
+	struct usb_descriptor_header **src,
+	struct usb_descriptor_header **copy,
+	struct usb_endpoint_descriptor *match);
+
+/**
+ * usb_free_descriptors - free descriptors returned by usb_copy_descriptors()
+ * @v: vector of descriptors
+ */
+static inline void usb_free_descriptors(struct usb_descriptor_header **v)
+{
+	kfree(v);
+}
+
 /*-------------------------------------------------------------------------*/
 
 /* utility wrapping a simple endpoint selection policy */