+ if (filter) {
+ ret = kernctl_filter(event->fd, filter);
+ if (ret) {
+ goto filter_error;
+ }
+ }
+
+ ret = kernctl_enable(event->fd);
+ if (ret < 0) {
+ switch (errno) {
+ case EEXIST:
+ ret = LTTNG_ERR_KERN_EVENT_EXIST;
+ break;
+ default:
+ PERROR("enable kernel event");
+ break;
+ }
+ goto enable_error;
+ }
+