efi_loader: correct notification of protocol installation

When a protocol is installed the handle should be queued for the
registration key of each registered event. LocateHandle() should return the
first handle from the queue for the registration key and delete it from the
queue.

Implement the queueing.

Correct the selftest.

With the patch the UEFI SCT tests for LocateHandle() are passed without
failure.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
diff --git a/include/efi_loader.h b/include/efi_loader.h
index 43d3a08..77b2f60 100644
--- a/include/efi_loader.h
+++ b/include/efi_loader.h
@@ -287,19 +287,37 @@
 extern struct list_head efi_events;
 
 /**
+ * struct efi_protocol_notification - handle for notified protocol
+ *
+ * When a protocol interface is installed for which an event was registered with
+ * the RegisterProtocolNotify() service this structure is used to hold the
+ * handle on which the protocol interface was installed.
+ *
+ * @link:	link to list of all handles notified for this event
+ * @handle:	handle on which the notified protocol interface was installed
+ */
+struct efi_protocol_notification {
+	struct list_head link;
+	efi_handle_t handle;
+};
+
+/**
  * efi_register_notify_event - event registered by RegisterProtocolNotify()
  *
  * The address of this structure serves as registration value.
  *
- * @link:		link to list of all registered events
- * @event:		registered event. The same event may registered for
- *			multiple GUIDs.
- * @protocol:		protocol for which the event is registered
+ * @link:	link to list of all registered events
+ * @event:	registered event. The same event may registered for multiple
+ *		GUIDs.
+ * @protocol:	protocol for which the event is registered
+ * @handles:	linked list of all handles on which the notified protocol was
+ *		installed
  */
 struct efi_register_notify_event {
 	struct list_head link;
 	struct efi_event *event;
 	efi_guid_t protocol;
+	struct list_head handles;
 };
 
 /* List of all events registered by RegisterProtocolNotify() */
diff --git a/lib/efi_loader/efi_boottime.c b/lib/efi_loader/efi_boottime.c
index 54fff85..1ccf54c 100644
--- a/lib/efi_loader/efi_boottime.c
+++ b/lib/efi_loader/efi_boottime.c
@@ -921,6 +921,14 @@
 	list_for_each_entry_safe(item, next, &efi_register_notify_events,
 				 link) {
 		if (event == item->event) {
+			struct efi_protocol_notification *hitem, *hnext;
+
+			/* Remove signaled handles */
+			list_for_each_entry_safe(hitem, hnext, &item->handles,
+						 link) {
+				list_del(&hitem->link);
+				free(hitem);
+			}
 			list_del(&item->link);
 			free(item);
 		}
@@ -1049,8 +1057,19 @@
 
 	/* Notify registered events */
 	list_for_each_entry(event, &efi_register_notify_events, link) {
-		if (!guidcmp(protocol, &event->protocol))
+		if (!guidcmp(protocol, &event->protocol)) {
+			struct efi_protocol_notification *notif;
+
+			notif = calloc(1, sizeof(*notif));
+			if (!notif) {
+				list_del(&handler->link);
+				free(handler);
+				return EFI_OUT_OF_RESOURCES;
+			}
+			notif->handle = handle;
+			list_add_tail(&notif->link, &event->handles);
 			efi_signal_event(event->event, true);
+		}
 	}
 
 	if (!guidcmp(&efi_guid_device_path, protocol))
@@ -1332,6 +1351,7 @@
 
 	item->event = event;
 	memcpy(&item->protocol, protocol, sizeof(efi_guid_t));
+	INIT_LIST_HEAD(&item->handles);
 
 	list_add_tail(&item->link, &efi_register_notify_events);
 
@@ -1359,7 +1379,6 @@
 	switch (search_type) {
 	case ALL_HANDLES:
 		return 0;
-	case BY_REGISTER_NOTIFY:
 	case BY_PROTOCOL:
 		ret = efi_search_protocol(handle, protocol, NULL);
 		return (ret != EFI_SUCCESS);
@@ -1391,6 +1410,7 @@
 	struct efi_object *efiobj;
 	efi_uintn_t size = 0;
 	struct efi_register_notify_event *item, *event = NULL;
+	struct efi_protocol_notification *handle = NULL;
 
 	/* Check parameters */
 	switch (search_type) {
@@ -1409,8 +1429,6 @@
 		}
 		if (!event)
 			return EFI_INVALID_PARAMETER;
-
-		protocol = &event->protocol;
 		break;
 	case BY_PROTOCOL:
 		if (!protocol)
@@ -1421,14 +1439,23 @@
 	}
 
 	/* Count how much space we need */
-	list_for_each_entry(efiobj, &efi_obj_list, link) {
-		if (!efi_search(search_type, protocol, efiobj))
-			size += sizeof(void *);
+	if (search_type == BY_REGISTER_NOTIFY) {
+		if (list_empty(&event->handles))
+			return EFI_NOT_FOUND;
+		handle = list_first_entry(&event->handles,
+					  struct efi_protocol_notification,
+					  link);
+		efiobj = handle->handle;
+		size += sizeof(void *);
+	} else {
+		list_for_each_entry(efiobj, &efi_obj_list, link) {
+			if (!efi_search(search_type, protocol, efiobj))
+				size += sizeof(void *);
+		}
+		if (size == 0)
+			return EFI_NOT_FOUND;
 	}
 
-	if (size == 0)
-		return EFI_NOT_FOUND;
-
 	if (!buffer_size)
 		return EFI_INVALID_PARAMETER;
 
@@ -1444,9 +1471,14 @@
 		return EFI_INVALID_PARAMETER;
 
 	/* Then fill the array */
-	list_for_each_entry(efiobj, &efi_obj_list, link) {
-		if (!efi_search(search_type, protocol, efiobj))
-			*buffer++ = efiobj;
+	if (search_type == BY_REGISTER_NOTIFY) {
+		*buffer = efiobj;
+		list_del(&handle->link);
+	} else {
+		list_for_each_entry(efiobj, &efi_obj_list, link) {
+			if (!efi_search(search_type, protocol, efiobj))
+				*buffer++ = efiobj;
+		}
 	}
 
 	return EFI_SUCCESS;
diff --git a/lib/efi_selftest/efi_selftest_register_notify.c b/lib/efi_selftest/efi_selftest_register_notify.c
index ee0ef39..ad763dd 100644
--- a/lib/efi_selftest/efi_selftest_register_notify.c
+++ b/lib/efi_selftest/efi_selftest_register_notify.c
@@ -47,15 +47,20 @@
 {
 	struct context *cp = context;
 	efi_status_t ret;
+	efi_uintn_t handle_count;
+	efi_handle_t *handles;
 
 	cp->notify_count++;
 
-	ret = boottime->locate_handle_buffer(BY_REGISTER_NOTIFY, NULL,
-					     cp->registration_key,
-					     &cp->handle_count,
-					     &cp->handles);
-	if (ret != EFI_SUCCESS)
-		cp->handle_count = 0;
+	for (;;) {
+		ret = boottime->locate_handle_buffer(BY_REGISTER_NOTIFY, NULL,
+						     cp->registration_key,
+						     &handle_count, &handles);
+		if (ret != EFI_SUCCESS)
+			break;
+		cp->handle_count += handle_count;
+		cp->handles = handles;
+	}
 }
 
 /*
@@ -170,7 +175,7 @@
 		efi_st_error("reinstall was notified too often\n");
 		return EFI_ST_FAILURE;
 	}
-	if (context.handle_count != 1) {
+	if (context.handle_count != 2) {
 		efi_st_error("LocateHandle failed\n");
 		return EFI_ST_FAILURE;
 	}
@@ -195,7 +200,7 @@
 		efi_st_error("install was notified too often\n");
 		return EFI_ST_FAILURE;
 	}
-	if (context.handle_count != 2) {
+	if (context.handle_count != 3) {
 		efi_st_error("LocateHandle failed\n");
 		return EFI_ST_FAILURE;
 	}