[PATCH 1/2] efi_loader: delete handle from events when a protocol is uninstalled

[Ilias Apalodimas]

When a notification event is registered for a protocol the handle of the
protocol is added in our event notification list.  When all the protocols
of the handle are uninstalled we delete the handle but we do not remove
it from the event notification list.

Clean up the protocol removal functions and add a wrapper which
- Removes the to-be deleted handle from any lists it participates
- Remove the handle if no more protocols are present

It's worth noting that all our variants of efi_uninstall_protocol_*()
and uninstall_multiple_protocol_*() end up calling
efi_uninstall_protocol().  We could add the cleanup in that function
only,  however efi_reinstall_protocol_interface() expects the handle not
to be removed.

Signed-off-by: Ilias Apalodimas <ilias.apalodimas at linaro.org>
---
 lib/efi_loader/efi_boottime.c | 45 +++++++++++++++++++++++++----------
 1 file changed, 33 insertions(+), 12 deletions(-)

diff --git a/lib/efi_loader/efi_boottime.c b/lib/efi_loader/efi_boottime.c
index d5065f296aee..450524ddca2f 100644
--- a/lib/efi_loader/efi_boottime.c
+++ b/lib/efi_loader/efi_boottime.c
@@ -197,6 +197,35 @@ static bool efi_event_is_queued(struct efi_event *event)
 	return !!event->queue_link.next;
 }
 
+/**
+ * efi_handle_cleanup() - Clean the deleted handle from the various lists
+ * @handle: handle to remove
+ * @force:  force removal even if protocols are still installed on the handle
+ *
+ * Return: status code
+ */
+static void efi_handle_cleanup(efi_handle_t handle, bool force)
+{
+	struct efi_register_notify_event *item, *next;
+
+	if (!list_empty(&handle->protocols) || force)
+		return;
+	/* The handle is about to be freed. Remove it from events */
+	list_for_each_entry_safe(item, next, &efi_register_notify_events, link) {
+		struct efi_protocol_notification *hitem, *hnext;
+
+		list_for_each_entry_safe(hitem, hnext, &item->handles, link) {
+			if (handle == hitem->handle) {
+				list_del(&hitem->link);
+				free(hitem);
+			}
+		}
+	}
+	/* The last protocol has been removed, delete the handle. */
+	list_del(&handle->link);
+	free(handle);
+}
+
 /**
  * efi_process_event_queue() - process event queue
  */
@@ -627,8 +656,7 @@ void efi_delete_handle(efi_handle_t handle)
 		return;
 	}
 
-	list_del(&handle->link);
-	free(handle);
+	efi_handle_cleanup(handle, true);
 }
 
 /**
@@ -1396,11 +1424,8 @@ static efi_status_t EFIAPI efi_uninstall_protocol_interface
 	if (ret != EFI_SUCCESS)
 		goto out;
 
-	/* If the last protocol has been removed, delete the handle. */
-	if (list_empty(&handle->protocols)) {
-		list_del(&handle->link);
-		free(handle);
-	}
+	/* Check if we have to purge the handle from various lists */
+	efi_handle_cleanup(handle, false);
 out:
 	return EFI_EXIT(ret);
 }
@@ -2777,11 +2802,7 @@ efi_uninstall_multiple_protocol_interfaces_int(efi_handle_t handle,
 		i++;
 	}
 	if (ret == EFI_SUCCESS) {
-		/* If the last protocol has been removed, delete the handle. */
-		if (list_empty(&handle->protocols)) {
-			list_del(&handle->link);
-			free(handle);
-		}
+		efi_handle_cleanup(handle, false);
 		goto out;
 	}
 
-- 
2.39.2