evdev: Make evdev manage its seat reference

Before the seat reference would be decreased when a device was removed.
This could cause libinput_device_get_seat() to potentially return an
invalid pointer when a device was removed, its seat unreferenced and
destryoed.

Signed-off-by: Jonas Ådahl <jadahl@gmail.com>

src/evdev.c

@@ -624,6 +624,8 @@ evdev_device_create(struct libinput_seat *seat,
 	devname[sizeof(devname) - 1] = '\0';
 	device->devname = strdup(devname);
 
+	libinput_seat_ref(seat);
+
 	if (evdev_configure_device(device) == -1)
 		goto err;
 
@@ -719,6 +721,8 @@ evdev_device_destroy(struct evdev_device *device)
 	if (dispatch)
 		dispatch->interface->destroy(dispatch);
 
+	libinput_seat_unref(device->base.seat);
+
 	free(device->devname);
 	free(device->devnode);
 	free(device->sysname);

src/path.c

@@ -40,20 +40,12 @@ path_input_disable(struct libinput *libinput)
 {
 	struct path_input *input = (struct path_input*)libinput;
 	struct evdev_device *device = input->device;
-	struct path_seat *seat, *tmp;
 
 	if (device) {
 		close_restricted(libinput, device->fd);
 		evdev_device_remove(device);
 		input->device = NULL;
 	}
-
-	/* should only be one seat anyway */
-	list_for_each_safe(seat, tmp, &libinput->seat_list, base.link) {
-		list_remove(&seat->base.link);
-		list_init(&seat->base.link);
-		libinput_seat_unref(&seat->base);
-	}
 }
 
 static void
@@ -155,16 +147,15 @@ path_input_enable(struct libinput *libinput)
 
 	device = evdev_device_create(&seat->base, devnode, syspath, fd);
 	free(syspath);
+	libinput_seat_unref(&seat->base);
 
 	if (device == EVDEV_UNHANDLED_DEVICE) {
 		close_restricted(libinput, fd);
 		log_info("not using input device '%s'.\n", devnode);
-		libinput_seat_unref(&seat->base);
 		return -1;
 	} else if (device == NULL) {
 		close_restricted(libinput, fd);
 		log_info("failed to create input device '%s'.\n", devnode);
-		libinput_seat_unref(&seat->base);
 		return -1;
 	}
 

src/udev-seat.c

@@ -83,19 +83,23 @@ device_added(struct udev_device *udev_device, struct udev_input *input)
 	 * read.  mtdev_get() also expects this. */
 	fd = open_restricted(libinput, devnode, O_RDWR | O_NONBLOCK);
 	if (fd < 0) {
-		log_info("opening input device '%s' failed (%s).\n", devnode, strerror(-fd));
+		log_info("opening input device '%s' failed (%s).\n",
-		goto error;
+			 devnode, strerror(-fd));
+		libinput_seat_unref(&seat->base);
+		return 0;
 	}
 
 	device = evdev_device_create(&seat->base, devnode, sysname, fd);
+	libinput_seat_unref(&seat->base);
+
 	if (device == EVDEV_UNHANDLED_DEVICE) {
 		close_restricted(libinput, fd);
 		log_info("not using input device '%s'.\n", devnode);
-		goto error;
+		return 0;
 	} else if (device == NULL) {
 		close_restricted(libinput, fd);
 		log_info("failed to create input device '%s'.\n", devnode);
-		goto error;
+		return 0;
 	}
 
 	calibration_values =
@@ -125,10 +129,6 @@ device_added(struct udev_device *udev_device, struct udev_input *input)
 		device->output_name = strdup(output_name);
 
 	return 0;
-error:
-	if (seat)
-		libinput_seat_unref(&seat->base);
-	return 0;
 }
 
 static int
@@ -200,7 +200,6 @@ evdev_udev_handler(void *data)
 						 device->devname, device->devnode);
 					close_restricted(libinput, device->fd);
 					evdev_device_remove(device);
-					libinput_seat_unref(&seat->base);
 					break;
 				}
 		}
@@ -230,7 +229,6 @@ udev_input_remove_devices(struct udev_input *input)
 				list_remove(&seat->base.link);
 				list_init(&seat->base.link);
 			}
-			libinput_seat_unref(&seat->base);
 		}
 		libinput_seat_unref(&seat->base);
 	}