+ tracker_list = get_id_tracker_list(session, tracker_type);
+ if (!tracker_list) {
+ return LTTNG_ERR_INVALID;
+ }
+ /* Save list for restore on error. */
+ saved_ids_count = lttng_tracker_id_get_list(tracker_list, &saved_ids);
+ if (saved_ids_count < 0) {
+ return LTTNG_ERR_INVALID;
+ }
+ /* Add to list. */
+ ret = lttng_tracker_list_add(tracker_list, id);
+ if (ret != LTTNG_OK) {
+ goto end;
+ }
+
+ switch (tracker_type) {
+ case LTTNG_TRACKER_PID:
+ DBG("Kernel track PID %d for session id %" PRIu64 ".",
+ value, session->id);
+ ret = kernctl_track_pid(session->fd, value);
+ if (!ret) {
+ ret = LTTNG_OK;
+ goto end;
+ }
+ break;
+ case LTTNG_TRACKER_VPID:
+ DBG("Kernel track VPID %d for session id %" PRIu64 ".",
+ value, session->id);
+ ret = kernctl_track_id(session->fd, LTTNG_TRACKER_VPID, value);
+ if (!ret) {
+ ret = LTTNG_OK;
+ goto end;
+ }
+ break;
+ case LTTNG_TRACKER_UID:
+ DBG("Kernel track UID %d for session id %" PRIu64 ".",
+ value, session->id);
+ ret = kernctl_track_id(session->fd, LTTNG_TRACKER_UID, value);
+ if (!ret) {
+ ret = LTTNG_OK;
+ goto end;
+ }
+ break;
+ case LTTNG_TRACKER_GID:
+ DBG("Kernel track GID %d for session id %" PRIu64 ".",
+ value, session->id);
+ ret = kernctl_track_id(session->fd, LTTNG_TRACKER_GID, value);
+ if (!ret) {
+ ret = LTTNG_OK;
+ goto end;
+ }
+ break;
+ case LTTNG_TRACKER_VUID:
+ DBG("Kernel track VUID %d for session id %" PRIu64 ".",
+ value, session->id);
+ ret = kernctl_track_id(session->fd, LTTNG_TRACKER_VUID, value);
+ if (!ret) {
+ ret = LTTNG_OK;
+ goto end;
+ }
+ break;
+ case LTTNG_TRACKER_VGID:
+ DBG("Kernel track VGID %d for session id %" PRIu64 ".",
+ value, session->id);
+ ret = kernctl_track_id(session->fd, LTTNG_TRACKER_VGID, value);
+ if (!ret) {
+ ret = LTTNG_OK;
+ goto end;
+ }
+ break;
+ default:
+ ret = -EINVAL;
+ break;