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>

include/efi_loader.h

@@ -286,20 +286,38 @@ extern struct list_head efi_obj_list;
 /* List of all events */
 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.
+ * @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() */

lib/efi_loader/efi_boottime.c

@@ -921,6 +921,14 @@ static efi_status_t EFIAPI efi_close_event(struct efi_event *event)
 	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);
 		}
@@ -1049,9 +1057,20 @@ efi_status_t efi_add_protocol(const efi_handle_t handle,
 
 	/* 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))
 		EFI_PRINT("installed device path '%pD'\n", protocol_interface);
@@ -1332,6 +1351,7 @@ static efi_status_t EFIAPI efi_register_protocol_notify(
 
 	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 @@ static int efi_search(enum efi_locate_search_type search_type,
 	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 @@ static efi_status_t efi_locate_handle(
 	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 @@ static efi_status_t efi_locate_handle(
 		}
 		if (!event)
 			return EFI_INVALID_PARAMETER;
-
-		protocol = &event->protocol;
 		break;
 	case BY_PROTOCOL:
 		if (!protocol)
@@ -1421,13 +1439,22 @@ static efi_status_t efi_locate_handle(
 	}
 
 	/* Count how much space we need */
+	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 (!buffer_size)
 		return EFI_INVALID_PARAMETER;
@@ -1444,10 +1471,15 @@ static efi_status_t efi_locate_handle(
 		return EFI_INVALID_PARAMETER;
 
 	/* Then fill the array */
+	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;
 }

lib/efi_selftest/efi_selftest_register_notify.c

@@ -47,15 +47,20 @@ static void EFIAPI notify(struct efi_event *event, void *context)
 {
 	struct context *cp = context;
 	efi_status_t ret;
+	efi_uintn_t handle_count;
+	efi_handle_t *handles;
 
 	cp->notify_count++;
 
+	for (;;) {
 		ret = boottime->locate_handle_buffer(BY_REGISTER_NOTIFY, NULL,
 						     cp->registration_key,
-					     &cp->handle_count,
-					     &cp->handles);
+						     &handle_count, &handles);
 		if (ret != EFI_SUCCESS)
-		cp->handle_count = 0;
+			break;
+		cp->handle_count += handle_count;
+		cp->handles = handles;
+	}
 }
 
 /*
@@ -170,7 +175,7 @@ static int execute(void)
 		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 @@ static int execute(void)
 		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;
 	}