- ret = LTTNG_ERR_KERN_ENABLE_FAIL;
- goto error;
- }
-
- /* Manage return value */
- if (ret != LTTNG_OK) {
- /*
- * On error, cmd_enable_channel call will take care of destroying
- * the created channel if it was needed.
- */
- goto error;
- }
-
- kernel_wait_quiescent(kernel_tracer_fd);
- break;
- }
- case LTTNG_DOMAIN_UST:
- {
- struct ltt_ust_channel *uchan;
- struct ltt_ust_session *usess = session->ust_session;
-
- assert(usess);
-
- /*
- * If a non-default channel has been created in the
- * session, explicitely require that -c chan_name needs
- * to be provided.
- */
- if (usess->has_non_default_channel && channel_name[0] == '\0') {
- ret = LTTNG_ERR_NEED_CHANNEL_NAME;
- goto error;
- }
-
- /* Get channel from global UST domain */
- uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
- channel_name);
- if (uchan == NULL) {
- /* Create default channel */
- attr = channel_new_default_attr(LTTNG_DOMAIN_UST,
- usess->buffer_type);
- if (attr == NULL) {
- ret = LTTNG_ERR_FATAL;
- goto error;
- }
- strncpy(attr->name, channel_name, sizeof(attr->name));
-
- ret = cmd_enable_channel(session, domain, attr, wpipe);
- if (ret != LTTNG_OK) {
- free(attr);
- goto error;
- }
- free(attr);
-
- /* Get the newly created channel reference back */
- uchan = trace_ust_find_channel_by_name(
- usess->domain_global.channels, channel_name);
- assert(uchan);
- }
-
- /* At this point, the session and channel exist on the tracer */
-
- switch (event_type) {
- case LTTNG_EVENT_ALL:
- case LTTNG_EVENT_TRACEPOINT:
- ret = event_ust_enable_all_tracepoints(usess, uchan, filter);
- if (ret != LTTNG_OK) {
- goto error;
- }
- break;
- default:
- ret = LTTNG_ERR_UST_ENABLE_FAIL;