+ /* This inhibits UST tracing */
+ pthread_mutex_lock(&app->sock_lock);
+ ret = ustctl_stop_session(app->sock, ua_sess->handle);
+ pthread_mutex_unlock(&app->sock_lock);
+ if (ret < 0) {
+ if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
+ ERR("Error stopping tracing for app pid: %d (ret: %d)",
+ app->pid, ret);
+ } else {
+ DBG("UST app stop session failed. Application is dead.");
+ /*
+ * This is normal behavior, an application can die during the
+ * creation process. Don't report an error so the execution can
+ * continue normally.
+ */
+ goto end_unlock;
+ }
+ goto error_rcu_unlock;
+ }
+
+ health_code_update();
+ ua_sess->enabled = 0;
+
+ /* Quiescent wait after stopping trace */
+ pthread_mutex_lock(&app->sock_lock);
+ ret = ustctl_wait_quiescent(app->sock);
+ pthread_mutex_unlock(&app->sock_lock);
+ if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
+ ERR("UST app wait quiescent failed for app pid %d ret %d",
+ app->pid, ret);
+ }
+
+ health_code_update();
+
+ registry = get_session_registry(ua_sess);
+
+ /* The UST app session is held registry shall not be null. */
+ assert(registry);
+
+ /* Push metadata for application before freeing the application. */
+ (void) push_metadata(registry, ua_sess->consumer);
+
+end_unlock:
+ pthread_mutex_unlock(&ua_sess->lock);
+end_no_session:
+ rcu_read_unlock();
+ health_code_update();
+ return 0;
+
+error_rcu_unlock:
+ pthread_mutex_unlock(&ua_sess->lock);
+ rcu_read_unlock();
+ health_code_update();
+ return -1;
+}
+
+static
+int ust_app_flush_app_session(struct ust_app *app,
+ struct ust_app_session *ua_sess)
+{
+ int ret, retval = 0;
+ struct lttng_ht_iter iter;
+ struct ust_app_channel *ua_chan;
+ struct consumer_socket *socket;
+
+ DBG("Flushing app session buffers for ust app pid %d", app->pid);
+
+ rcu_read_lock();
+
+ if (!app->compatible) {
+ goto end_not_compatible;
+ }
+
+ pthread_mutex_lock(&ua_sess->lock);
+
+ if (ua_sess->deleted) {
+ goto end_deleted;
+ }
+
+ health_code_update();
+
+ /* Flushing buffers */
+ socket = consumer_find_socket_by_bitness(app->bits_per_long,
+ ua_sess->consumer);
+
+ /* Flush buffers and push metadata. */
+ switch (ua_sess->buffer_type) {
+ case LTTNG_BUFFER_PER_PID:
+ cds_lfht_for_each_entry(ua_sess->channels->ht, &iter.iter, ua_chan,
+ node.node) {
+ health_code_update();
+ ret = consumer_flush_channel(socket, ua_chan->key);
+ if (ret) {
+ ERR("Error flushing consumer channel");
+ retval = -1;
+ continue;
+ }
+ }
+ break;
+ case LTTNG_BUFFER_PER_UID:
+ default:
+ assert(0);
+ break;
+ }
+
+ health_code_update();
+
+end_deleted:
+ pthread_mutex_unlock(&ua_sess->lock);
+
+end_not_compatible:
+ rcu_read_unlock();
+ health_code_update();
+ return retval;
+}
+
+/*
+ * Flush buffers for all applications for a specific UST session.
+ * Called with UST session lock held.
+ */
+static
+int ust_app_flush_session(struct ltt_ust_session *usess)
+
+{
+ int ret = 0;
+
+ DBG("Flushing session buffers for all ust apps");
+
+ rcu_read_lock();
+
+ /* Flush buffers and push metadata. */
+ switch (usess->buffer_type) {
+ case LTTNG_BUFFER_PER_UID:
+ {
+ struct buffer_reg_uid *reg;
+ struct lttng_ht_iter iter;
+
+ /* Flush all per UID buffers associated to that session. */
+ cds_list_for_each_entry(reg, &usess->buffer_reg_uid_list, lnode) {
+ struct ust_registry_session *ust_session_reg;
+ struct buffer_reg_channel *buf_reg_chan;
+ struct consumer_socket *socket;
+
+ /* Get consumer socket to use to push the metadata.*/
+ socket = consumer_find_socket_by_bitness(reg->bits_per_long,
+ usess->consumer);
+ if (!socket) {
+ /* Ignore request if no consumer is found for the session. */
+ continue;
+ }
+
+ cds_lfht_for_each_entry(reg->registry->channels->ht, &iter.iter,
+ buf_reg_chan, node.node) {
+ /*
+ * The following call will print error values so the return
+ * code is of little importance because whatever happens, we
+ * have to try them all.
+ */
+ (void) consumer_flush_channel(socket, buf_reg_chan->consumer_key);
+ }
+
+ ust_session_reg = reg->registry->reg.ust;
+ /* Push metadata. */
+ (void) push_metadata(ust_session_reg, usess->consumer);
+ }
+ break;
+ }
+ case LTTNG_BUFFER_PER_PID:
+ {
+ struct ust_app_session *ua_sess;
+ struct lttng_ht_iter iter;
+ struct ust_app *app;
+
+ cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
+ ua_sess = lookup_session_by_app(usess, app);
+ if (ua_sess == NULL) {
+ continue;
+ }
+ (void) ust_app_flush_app_session(app, ua_sess);
+ }
+ break;
+ }
+ default:
+ ret = -1;
+ assert(0);
+ break;
+ }
+
+ rcu_read_unlock();
+ health_code_update();
+ return ret;
+}
+
+static
+int ust_app_clear_quiescent_app_session(struct ust_app *app,
+ struct ust_app_session *ua_sess)
+{
+ int ret = 0;
+ struct lttng_ht_iter iter;
+ struct ust_app_channel *ua_chan;
+ struct consumer_socket *socket;
+
+ DBG("Clearing stream quiescent state for ust app pid %d", app->pid);
+
+ rcu_read_lock();
+
+ if (!app->compatible) {
+ goto end_not_compatible;
+ }
+
+ pthread_mutex_lock(&ua_sess->lock);
+
+ if (ua_sess->deleted) {
+ goto end_unlock;
+ }
+
+ health_code_update();
+
+ socket = consumer_find_socket_by_bitness(app->bits_per_long,
+ ua_sess->consumer);
+ if (!socket) {
+ ERR("Failed to find consumer (%" PRIu32 ") socket",
+ app->bits_per_long);
+ ret = -1;
+ goto end_unlock;
+ }
+
+ /* Clear quiescent state. */
+ switch (ua_sess->buffer_type) {
+ case LTTNG_BUFFER_PER_PID:
+ cds_lfht_for_each_entry(ua_sess->channels->ht, &iter.iter,
+ ua_chan, node.node) {
+ health_code_update();
+ ret = consumer_clear_quiescent_channel(socket,
+ ua_chan->key);
+ if (ret) {
+ ERR("Error clearing quiescent state for consumer channel");
+ ret = -1;
+ continue;
+ }
+ }
+ break;
+ case LTTNG_BUFFER_PER_UID:
+ default:
+ assert(0);
+ ret = -1;
+ break;
+ }
+
+ health_code_update();
+
+end_unlock:
+ pthread_mutex_unlock(&ua_sess->lock);
+
+end_not_compatible:
+ rcu_read_unlock();
+ health_code_update();
+ return ret;
+}
+
+/*
+ * Clear quiescent state in each stream for all applications for a
+ * specific UST session.
+ * Called with UST session lock held.
+ */
+static
+int ust_app_clear_quiescent_session(struct ltt_ust_session *usess)
+
+{
+ int ret = 0;
+
+ DBG("Clearing stream quiescent state for all ust apps");
+
+ rcu_read_lock();
+
+ switch (usess->buffer_type) {
+ case LTTNG_BUFFER_PER_UID:
+ {
+ struct lttng_ht_iter iter;
+ struct buffer_reg_uid *reg;
+
+ /*
+ * Clear quiescent for all per UID buffers associated to
+ * that session.
+ */
+ cds_list_for_each_entry(reg, &usess->buffer_reg_uid_list, lnode) {
+ struct consumer_socket *socket;
+ struct buffer_reg_channel *buf_reg_chan;
+
+ /* Get associated consumer socket.*/
+ socket = consumer_find_socket_by_bitness(
+ reg->bits_per_long, usess->consumer);
+ if (!socket) {
+ /*
+ * Ignore request if no consumer is found for
+ * the session.
+ */
+ continue;
+ }
+
+ cds_lfht_for_each_entry(reg->registry->channels->ht,
+ &iter.iter, buf_reg_chan, node.node) {
+ /*
+ * The following call will print error values so
+ * the return code is of little importance
+ * because whatever happens, we have to try them
+ * all.
+ */
+ (void) consumer_clear_quiescent_channel(socket,
+ buf_reg_chan->consumer_key);
+ }
+ }
+ break;
+ }
+ case LTTNG_BUFFER_PER_PID:
+ {
+ struct ust_app_session *ua_sess;
+ struct lttng_ht_iter iter;
+ struct ust_app *app;
+
+ cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app,
+ pid_n.node) {
+ ua_sess = lookup_session_by_app(usess, app);
+ if (ua_sess == NULL) {
+ continue;
+ }
+ (void) ust_app_clear_quiescent_app_session(app,
+ ua_sess);
+ }
+ break;
+ }
+ default:
+ ret = -1;
+ assert(0);
+ break;
+ }
+
+ rcu_read_unlock();
+ health_code_update();
+ return ret;
+}
+
+/*
+ * Destroy a specific UST session in apps.
+ */
+static int destroy_trace(struct ltt_ust_session *usess, struct ust_app *app)
+{
+ int ret;
+ struct ust_app_session *ua_sess;
+ struct lttng_ht_iter iter;
+ struct lttng_ht_node_u64 *node;
+
+ DBG("Destroy tracing for ust app pid %d", app->pid);
+
+ rcu_read_lock();
+
+ if (!app->compatible) {
+ goto end;
+ }
+
+ __lookup_session_by_app(usess, app, &iter);
+ node = lttng_ht_iter_get_node_u64(&iter);
+ if (node == NULL) {
+ /* Session is being or is deleted. */
+ goto end;
+ }
+ ua_sess = caa_container_of(node, struct ust_app_session, node);
+
+ health_code_update();
+ destroy_app_session(app, ua_sess);
+
+ health_code_update();
+
+ /* Quiescent wait after stopping trace */
+ pthread_mutex_lock(&app->sock_lock);
+ ret = ustctl_wait_quiescent(app->sock);
+ pthread_mutex_unlock(&app->sock_lock);
+ if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
+ ERR("UST app wait quiescent failed for app pid %d ret %d",
+ app->pid, ret);
+ }
+end:
+ rcu_read_unlock();
+ health_code_update();
+ return 0;
+}
+
+/*
+ * Start tracing for the UST session.
+ */
+int ust_app_start_trace_all(struct ltt_ust_session *usess)
+{
+ struct lttng_ht_iter iter;
+ struct ust_app *app;
+
+ DBG("Starting all UST traces");
+
+ /*
+ * Even though the start trace might fail, flag this session active so
+ * other application coming in are started by default.
+ */
+ usess->active = 1;
+
+ rcu_read_lock();
+
+ /*
+ * In a start-stop-start use-case, we need to clear the quiescent state
+ * of each channel set by the prior stop command, thus ensuring that a
+ * following stop or destroy is sure to grab a timestamp_end near those
+ * operations, even if the packet is empty.
+ */
+ (void) ust_app_clear_quiescent_session(usess);
+
+ cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
+ ust_app_global_update(usess, app);
+ }
+
+ rcu_read_unlock();
+
+ return 0;
+}
+
+/*
+ * Start tracing for the UST session.
+ * Called with UST session lock held.
+ */
+int ust_app_stop_trace_all(struct ltt_ust_session *usess)
+{
+ int ret = 0;
+ struct lttng_ht_iter iter;
+ struct ust_app *app;
+
+ DBG("Stopping all UST traces");
+
+ /*
+ * Even though the stop trace might fail, flag this session inactive so
+ * other application coming in are not started by default.
+ */
+ usess->active = 0;
+
+ rcu_read_lock();
+
+ cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
+ ret = ust_app_stop_trace(usess, app);
+ if (ret < 0) {
+ /* Continue to next apps even on error */
+ continue;
+ }
+ }
+
+ (void) ust_app_flush_session(usess);
+
+ rcu_read_unlock();
+
+ return 0;
+}
+
+/*
+ * Destroy app UST session.
+ */
+int ust_app_destroy_trace_all(struct ltt_ust_session *usess)
+{
+ int ret = 0;
+ struct lttng_ht_iter iter;
+ struct ust_app *app;
+
+ DBG("Destroy all UST traces");
+
+ rcu_read_lock();
+
+ cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
+ ret = destroy_trace(usess, app);
+ if (ret < 0) {
+ /* Continue to next apps even on error */
+ continue;
+ }
+ }
+
+ rcu_read_unlock();
+
+ return 0;
+}
+
+/* The ua_sess lock must be held by the caller. */
+static
+int find_or_create_ust_app_channel(
+ struct ltt_ust_session *usess,
+ struct ust_app_session *ua_sess,
+ struct ust_app *app,
+ struct ltt_ust_channel *uchan,
+ struct ust_app_channel **ua_chan)
+{
+ int ret = 0;
+ struct lttng_ht_iter iter;
+ struct lttng_ht_node_str *ua_chan_node;
+
+ lttng_ht_lookup(ua_sess->channels, (void *) uchan->name, &iter);
+ ua_chan_node = lttng_ht_iter_get_node_str(&iter);
+ if (ua_chan_node) {
+ *ua_chan = caa_container_of(ua_chan_node,
+ struct ust_app_channel, node);
+ goto end;
+ }
+
+ ret = ust_app_channel_create(usess, ua_sess, uchan, app, ua_chan);
+ if (ret) {
+ goto end;
+ }
+end:
+ return ret;
+}
+
+/* The ua_sess lock must be held by the caller. */
+static
+int find_or_create_ust_app_map(
+ struct ltt_ust_session *usess,
+ struct ust_app_session *ua_sess,
+ struct ust_app *app,
+ struct ltt_ust_map *umap,
+ struct ust_app_map **ua_map)
+{
+ int ret = 0;
+ struct lttng_ht_iter iter;
+ struct lttng_ht_node_str *ua_map_node;
+
+ lttng_ht_lookup(ua_sess->maps, (void *) umap->name, &iter);
+ ua_map_node = lttng_ht_iter_get_node_str(&iter);
+ if (ua_map_node) {
+ *ua_map = caa_container_of(ua_map_node,
+ struct ust_app_map, node);
+ goto end;
+ }
+
+ DBG("UST map id = %"PRIu64" not found. Creating it.", umap->id);
+ ret = ust_app_map_create(usess, ua_sess, umap, app, ua_map);
+ if (ret) {
+ goto end;
+ }
+end:
+ return ret;
+}
+
+static
+int ust_app_channel_synchronize_event(struct ust_app_channel *ua_chan,
+ struct ltt_ust_event *uevent, struct ust_app_session *ua_sess,
+ struct ust_app *app)
+{
+ int ret = 0;
+ struct ust_app_event *ua_event = NULL;
+
+ ua_event = find_ust_app_event(ua_chan->events, uevent->attr.name,
+ uevent->filter, uevent->attr.loglevel, uevent->exclusion,
+ uevent->attr.token);
+ if (!ua_event) {
+ ret = create_ust_app_channel_event(ua_sess, ua_chan, uevent, app);
+
+ if (ret < 0) {
+ goto end;
+ }
+ } else {
+ if (ua_event->enabled != uevent->enabled) {
+ ret = uevent->enabled ?
+ enable_ust_app_event(ua_sess, ua_event, app) :
+ disable_ust_app_event(ua_sess, ua_event, app);
+ }
+ }
+
+end:
+ return ret;
+}
+
+/* Called with RCU read-side lock held. */
+static
+int ust_app_map_synchronize_event(struct ust_app_map *ua_map,
+ struct ltt_ust_event *uevent, struct ust_app_session *ua_sess,
+ struct ust_app *app)
+{
+ int ret = 0;
+ struct ust_app_event *ua_event = NULL;
+
+ ua_event = find_ust_app_event(ua_map->events, uevent->attr.name,
+ uevent->filter, uevent->attr.loglevel, uevent->exclusion,
+ uevent->attr.token);
+ if (!ua_event) {
+ ret = create_ust_app_map_event(ua_sess, ua_map, uevent, app);
+ if (ret < 0) {
+ goto end;
+ }
+ } else {
+ if (ua_event->enabled != uevent->enabled) {
+ ret = uevent->enabled ?
+ enable_ust_app_event(ua_sess, ua_event, app) :
+ disable_ust_app_event(ua_sess, ua_event, app);
+ }
+ }
+
+end:
+ return ret;
+}
+
+static
+void ust_app_synchronize_event_notifier_rules(struct ust_app *app)
+{
+ int ret = 0;
+ enum lttng_error_code ret_code;
+ enum lttng_trigger_status t_status;
+ struct lttng_ht_iter app_trigger_iter;
+ struct lttng_triggers *triggers = NULL;
+ struct ust_app_event_notifier_rule *event_notifier_rule;
+ unsigned int count, i;
+
+ /*
+ * Currrently, registering or unregistering a trigger with an
+ * event rule condition causes a full synchronization of the event
+ * notifiers.
+ *
+ * The first step attempts to add an event notifier for all registered
+ * triggers that apply to the user space tracers. Then, the
+ * application's event notifiers rules are all checked against the list
+ * of registered triggers. Any event notifier that doesn't have a
+ * matching trigger can be assumed to have been disabled.
+ *
+ * All of this is inefficient, but is put in place to get the feature
+ * rolling as it is simpler at this moment. It will be optimized Soon™
+ * to allow the state of enabled
+ * event notifiers to be synchronized in a piece-wise way.
+ */
+
+ /* Get all triggers using uid 0 (root) */
+ ret_code = notification_thread_command_list_triggers(
+ notification_thread_handle, 0, &triggers);
+ if (ret_code != LTTNG_OK) {
+ ret = -1;
+ goto end;
+ }
+
+ assert(triggers);
+
+ t_status = lttng_triggers_get_count(triggers, &count);
+ if (t_status != LTTNG_TRIGGER_STATUS_OK) {
+ ret = -1;
+ goto end;
+ }
+
+ for (i = 0; i < count; i++) {
+ const struct lttng_condition *condition;
+ const struct lttng_event_rule *event_rule;
+ struct lttng_trigger *trigger;
+ const struct ust_app_event_notifier_rule *looked_up_event_notifier_rule;
+ enum lttng_condition_status condition_status;
+ uint64_t token;
+
+ trigger = lttng_triggers_borrow_mutable_at_index(triggers, i);
+ assert(trigger);
+
+ token = lttng_trigger_get_tracer_token(trigger);
+ condition = lttng_trigger_get_const_condition(trigger);
+
+ if (!lttng_trigger_needs_tracer_notifier(trigger)) {
+ continue;
+ }
+
+ condition_status = lttng_condition_on_event_get_rule(condition, &event_rule);
+ assert(condition_status == LTTNG_CONDITION_STATUS_OK);
+
+ if (lttng_event_rule_get_domain_type(event_rule) == LTTNG_DOMAIN_KERNEL) {
+ /* Skip kernel related triggers. */
+ continue;
+ }
+
+ /*
+ * Find or create the associated token event rule. The caller
+ * holds the RCU read lock, so this is safe to call without
+ * explicitly acquiring it here.
+ */
+ looked_up_event_notifier_rule = find_ust_app_event_notifier_rule(
+ app->token_to_event_notifier_rule_ht, token);
+ if (!looked_up_event_notifier_rule) {
+ ret = create_ust_app_event_notifier_rule(trigger, app);
+ if (ret < 0) {
+ goto end;
+ }
+ }
+ }
+
+ rcu_read_lock();
+ /* Remove all unknown event sources from the app. */
+ cds_lfht_for_each_entry (app->token_to_event_notifier_rule_ht->ht,
+ &app_trigger_iter.iter, event_notifier_rule,
+ node.node) {
+ const uint64_t app_token = event_notifier_rule->token;
+ bool found = false;
+
+ /*
+ * Check if the app event trigger still exists on the
+ * notification side.
+ */
+ for (i = 0; i < count; i++) {
+ uint64_t notification_thread_token;
+ const struct lttng_trigger *trigger =
+ lttng_triggers_get_at_index(
+ triggers, i);
+
+ assert(trigger);
+
+ notification_thread_token =
+ lttng_trigger_get_tracer_token(trigger);
+
+ if (notification_thread_token == app_token) {
+ found = true;
+ break;
+ }
+ }
+
+ if (found) {
+ /* Still valid. */
+ continue;
+ }
+
+ /*
+ * This trigger was unregistered, disable it on the tracer's
+ * side.
+ */
+ ret = lttng_ht_del(app->token_to_event_notifier_rule_ht,
+ &app_trigger_iter);
+ assert(ret == 0);
+
+ /* Callee logs errors. */
+ (void) disable_ust_object(app, event_notifier_rule->obj);
+
+ delete_ust_app_event_notifier_rule(
+ app->sock, event_notifier_rule, app);
+ }
+
+ rcu_read_unlock();
+
+end:
+ lttng_triggers_destroy(triggers);
+ return;
+}
+
+/*
+ * Called with RCU read-side lock held.
+ */
+static
+void ust_app_synchronize_all_channels(struct ltt_ust_session *usess,
+ struct ust_app_session *ua_sess,
+ struct ust_app *app)
+{
+ int ret = 0;
+ struct cds_lfht_iter uchan_iter;
+ struct ltt_ust_channel *uchan;
+
+ assert(usess);
+ assert(ua_sess);
+ assert(app);
+
+ cds_lfht_for_each_entry(usess->domain_global.channels->ht, &uchan_iter,
+ uchan, node.node) {
+ struct ust_app_channel *ua_chan;
+ struct cds_lfht_iter uevent_iter;
+ struct ltt_ust_event *uevent;
+
+ /*
+ * Search for a matching ust_app_channel. If none is found,
+ * create it. Creating the channel will cause the ua_chan
+ * structure to be allocated, the channel buffers to be
+ * allocated (if necessary) and sent to the application, and
+ * all enabled contexts will be added to the channel.
+ */
+ ret = find_or_create_ust_app_channel(usess, ua_sess,
+ app, uchan, &ua_chan);
+ if (ret) {
+ /* Tracer is probably gone or ENOMEM. */
+ goto end;
+ }
+
+ if (!ua_chan) {
+ /* ua_chan will be NULL for the metadata channel */
+ continue;
+ }
+
+ cds_lfht_for_each_entry(uchan->events->ht, &uevent_iter, uevent,
+ node.node) {
+ ret = ust_app_channel_synchronize_event(ua_chan,
+ uevent, ua_sess, app);
+ if (ret) {
+ goto end;
+ }
+ }
+
+ if (ua_chan->enabled != uchan->enabled) {
+ ret = uchan->enabled ?
+ enable_ust_app_channel(ua_sess, uchan, app) :
+ disable_ust_app_channel(ua_sess, ua_chan, app);
+ if (ret) {
+ goto end;
+ }
+ }
+ }
+end:
+ return;
+}
+
+/*
+ * Called with RCU read-side lock held.
+ */
+static
+void ust_app_synchronize_all_maps(struct ltt_ust_session *usess,
+ struct ust_app_session *ua_sess,
+ struct ust_app *app)
+{
+ int ret = 0;
+ struct cds_lfht_iter umap_iter;
+ struct ltt_ust_map *umap;
+
+ assert(usess);
+ assert(ua_sess);
+ assert(app);
+
+ cds_lfht_for_each_entry(usess->domain_global.maps->ht, &umap_iter,
+ umap, node.node) {
+ struct ust_app_map *ua_map;
+ struct cds_lfht_iter uevent_iter;
+ struct ltt_ust_event *uevent;
+
+ DBG("Synchronizing UST map id = %"PRIu64, umap->id);
+
+ ret = find_or_create_ust_app_map(usess, ua_sess,
+ app, umap, &ua_map);
+ if (ret) {
+ /* Tracer is probably gone or ENOMEM. */
+ goto end;
+ }
+
+ DBG("Synchronizing all events of UST map id = %"PRIu64, umap->id);
+ cds_lfht_for_each_entry(umap->events->ht, &uevent_iter, uevent,
+ node.node) {
+ ret = ust_app_map_synchronize_event(ua_map,
+ uevent, ua_sess, app);
+ if (ret) {
+ goto end;
+ }
+ }
+
+ if (ua_map->enabled != umap->enabled) {
+ if (umap->enabled) {
+ DBG("Map disabled on the tracer side but shouldn't");
+ ret = enable_ust_app_map(ua_sess, umap, app);
+ } else {
+ DBG("Map enabled on the tracer side but shouldn't");
+ ret = disable_ust_app_map(ua_sess, ua_map, app);
+ }
+ if (ret) {
+ goto end;
+ }
+ }
+ }
+end:
+ return;
+}
+
+/*
+ * The caller must ensure that the application is compatible and is tracked
+ * by the process attribute trackers.
+ */
+static
+void ust_app_synchronize(struct ltt_ust_session *usess,
+ struct ust_app *app)
+{
+ int ret = 0;
+ struct ust_app_session *ua_sess = NULL;
+
+ /*
+ * The application's configuration should only be synchronized for
+ * active sessions.
+ */
+ assert(usess->active);
+
+ ret = find_or_create_ust_app_session(usess, app, &ua_sess, NULL);
+ if (ret < 0) {
+ /* Tracer is probably gone or ENOMEM. */
+ goto error;
+ }
+ assert(ua_sess);
+
+
+ rcu_read_lock();
+
+ pthread_mutex_lock(&ua_sess->lock);
+ if (ua_sess->deleted) {
+ pthread_mutex_unlock(&ua_sess->lock);
+ goto end;
+ }
+ ust_app_synchronize_all_channels(usess, ua_sess, app);
+ ust_app_synchronize_all_maps(usess, ua_sess, app);
+
+ /*
+ * Create the metadata for the application. This returns gracefully if a
+ * metadata was already set for the session.
+ *
+ * The metadata channel must be created after the data channels as the
+ * consumer daemon assumes this ordering. When interacting with a relay
+ * daemon, the consumer will use this assumption to send the
+ * "STREAMS_SENT" message to the relay daemon.
+ */
+ ret = create_ust_app_metadata(ua_sess, app, usess->consumer);
+ if (ret < 0) {
+ goto error_unlock;
+ }
+
+ rcu_read_unlock();
+
+end:
+ pthread_mutex_unlock(&ua_sess->lock);
+ /* Everything went well at this point. */
+ return;
+
+error_unlock:
+ rcu_read_unlock();
+ pthread_mutex_unlock(&ua_sess->lock);
+error:
+ if (ua_sess) {
+ destroy_app_session(app, ua_sess);
+ }
+ return;
+}
+
+static
+void ust_app_global_destroy(struct ltt_ust_session *usess, struct ust_app *app)
+{
+ struct ust_app_session *ua_sess;
+
+ ua_sess = lookup_session_by_app(usess, app);
+ if (ua_sess == NULL) {
+ return;
+ }
+ destroy_app_session(app, ua_sess);
+}
+
+/*
+ * Add channels/events from UST global domain to registered apps at sock.
+ *
+ * Called with session lock held.
+ * Called with RCU read-side lock held.
+ */
+void ust_app_global_update(struct ltt_ust_session *usess, struct ust_app *app)
+{
+ assert(usess);
+ assert(usess->active);
+
+ DBG2("UST app global update for app sock %d for session id %" PRIu64,
+ app->sock, usess->id);
+
+ if (!app->compatible) {
+ return;
+ }
+ if (trace_ust_id_tracker_lookup(LTTNG_PROCESS_ATTR_VIRTUAL_PROCESS_ID,
+ usess, app->pid) &&
+ trace_ust_id_tracker_lookup(
+ LTTNG_PROCESS_ATTR_VIRTUAL_USER_ID,
+ usess, app->uid) &&
+ trace_ust_id_tracker_lookup(
+ LTTNG_PROCESS_ATTR_VIRTUAL_GROUP_ID,
+ usess, app->gid)) {
+ /*
+ * Synchronize the application's internal tracing configuration
+ * and start tracing.
+ */
+ ust_app_synchronize(usess, app);
+ ust_app_start_trace(usess, app);
+ } else {
+ ust_app_global_destroy(usess, app);
+ }
+}
+
+/*
+ * Add all event notifiers to an application.
+ *
+ * Called with session lock held.
+ * Called with RCU read-side lock held.
+ */
+void ust_app_global_update_event_notifier_rules(struct ust_app *app)
+{
+ DBG2("UST application global event notifier rules update: app = '%s' (ppid: %d)",
+ app->name, app->ppid);
+
+ if (!app->compatible) {
+ return;
+ }
+
+ if (app->event_notifier_group.object == NULL) {
+ WARN("UST app global update of event notifiers for app skipped since communication handle is null: app = '%s' (ppid: %d)",
+ app->name, app->ppid);
+ return;
+ }
+
+ ust_app_synchronize_event_notifier_rules(app);
+}
+
+/*
+ * Called with session lock held.
+ */
+void ust_app_global_update_all(struct ltt_ust_session *usess)
+{
+ struct lttng_ht_iter iter;
+ struct ust_app *app;
+
+ rcu_read_lock();
+ cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
+ ust_app_global_update(usess, app);
+ }
+ rcu_read_unlock();
+}
+
+void ust_app_global_update_all_event_notifier_rules(void)
+{
+ struct lttng_ht_iter iter;
+ struct ust_app *app;
+
+ rcu_read_lock();
+ cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
+ ust_app_global_update_event_notifier_rules(app);
+ }
+
+ rcu_read_unlock();
+}
+
+void ust_app_update_event_notifier_error_count(struct lttng_trigger *trigger)
+{
+ uint64_t error_count = 0;
+ enum event_notifier_error_accounting_status status;
+ struct lttng_condition *condition = lttng_trigger_get_condition(trigger);
+
+ status = event_notifier_error_accounting_get_count(trigger, &error_count);
+ if (status != EVENT_NOTIFIER_ERROR_ACCOUNTING_STATUS_OK) {
+ ERR("Error getting trigger error count.");
+ }
+
+ lttng_condition_on_event_set_error_count(condition, error_count);
+}
+
+/*
+ * Add context to a specific channel for global UST domain.
+ */
+int ust_app_add_ctx_channel_glb(struct ltt_ust_session *usess,
+ struct ltt_ust_channel *uchan, struct ltt_ust_context *uctx)
+{
+ int ret = 0;
+ struct lttng_ht_node_str *ua_chan_node;
+ struct lttng_ht_iter iter, uiter;
+ struct ust_app_channel *ua_chan = NULL;
+ struct ust_app_session *ua_sess;
+ struct ust_app *app;
+
+ assert(usess->active);
+
+ rcu_read_lock();
+ cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
+ if (!app->compatible) {
+ /*
+ * TODO: In time, we should notice the caller of this error by
+ * telling him that this is a version error.
+ */
+ continue;
+ }
+ ua_sess = lookup_session_by_app(usess, app);
+ if (ua_sess == NULL) {
+ continue;
+ }
+
+ pthread_mutex_lock(&ua_sess->lock);
+
+ if (ua_sess->deleted) {
+ pthread_mutex_unlock(&ua_sess->lock);
+ continue;
+ }
+
+ /* Lookup channel in the ust app session */
+ lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &uiter);
+ ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
+ if (ua_chan_node == NULL) {
+ goto next_app;
+ }
+ ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel,
+ node);
+ ret = create_ust_app_channel_context(ua_chan, &uctx->ctx, app);
+ if (ret < 0) {
+ goto next_app;
+ }
+ next_app:
+ pthread_mutex_unlock(&ua_sess->lock);
+ }
+
+ rcu_read_unlock();
+ return ret;
+}
+
+/*
+ * Receive registration and populate the given msg structure.
+ *
+ * On success return 0 else a negative value returned by the ustctl call.
+ */
+int ust_app_recv_registration(int sock, struct ust_register_msg *msg)
+{
+ int ret;
+ uint32_t pid, ppid, uid, gid;
+
+ assert(msg);
+
+ ret = ustctl_recv_reg_msg(sock, &msg->type, &msg->major, &msg->minor,
+ &pid, &ppid, &uid, &gid,
+ &msg->bits_per_long,
+ &msg->uint8_t_alignment,
+ &msg->uint16_t_alignment,
+ &msg->uint32_t_alignment,
+ &msg->uint64_t_alignment,
+ &msg->long_alignment,
+ &msg->byte_order,
+ msg->name);
+ if (ret < 0) {
+ switch (-ret) {
+ case EPIPE:
+ case ECONNRESET:
+ case LTTNG_UST_ERR_EXITING:
+ DBG3("UST app recv reg message failed. Application died");
+ break;
+ case LTTNG_UST_ERR_UNSUP_MAJOR:
+ ERR("UST app recv reg unsupported version %d.%d. Supporting %d.%d",
+ msg->major, msg->minor, LTTNG_UST_ABI_MAJOR_VERSION,
+ LTTNG_UST_ABI_MINOR_VERSION);
+ break;
+ default:
+ ERR("UST app recv reg message failed with ret %d", ret);
+ break;
+ }
+ goto error;
+ }
+ msg->pid = (pid_t) pid;
+ msg->ppid = (pid_t) ppid;
+ msg->uid = (uid_t) uid;
+ msg->gid = (gid_t) gid;
+
+error:
+ return ret;
+}
+
+/*
+ * Return a ust app session object using the application object and the
+ * session object descriptor has a key. If not found, NULL is returned.
+ * A RCU read side lock MUST be acquired when calling this function.
+*/
+static struct ust_app_session *find_session_by_objd(struct ust_app *app,
+ int objd)
+{
+ struct lttng_ht_node_ulong *node;
+ struct lttng_ht_iter iter;
+ struct ust_app_session *ua_sess = NULL;
+
+ assert(app);
+
+ lttng_ht_lookup(app->ust_sessions_objd, (void *)((unsigned long) objd), &iter);
+ node = lttng_ht_iter_get_node_ulong(&iter);
+ if (node == NULL) {
+ DBG2("UST app session find by objd %d not found", objd);
+ goto error;
+ }
+
+ ua_sess = caa_container_of(node, struct ust_app_session, ust_objd_node);
+
+error:
+ return ua_sess;
+}
+
+/*
+ * Return a ust app channel object using the application object and the channel
+ * object descriptor has a key. If not found, NULL is returned. A RCU read side
+ * lock MUST be acquired before calling this function.
+ */
+static struct ust_app_channel *find_channel_by_objd(struct ust_app *app,
+ int objd)
+{
+ struct lttng_ht_node_ulong *node;
+ struct lttng_ht_iter iter;
+ struct ust_app_channel *ua_chan = NULL;
+
+ assert(app);
+
+ lttng_ht_lookup(app->ust_chan_objd, (void *)((unsigned long) objd), &iter);
+ node = lttng_ht_iter_get_node_ulong(&iter);
+ if (node == NULL) {
+ DBG2("UST app channel find by objd %d not found", objd);
+ goto error;
+ }
+
+ ua_chan = caa_container_of(node, struct ust_app_channel, ust_objd_node);
+
+error:
+ return ua_chan;
+}
+
+/*
+ * Return a ust app map object using the application object and the map
+ * object descriptor has a key. If not found, NULL is returned. A RCU read side
+ * lock MUST be acquired before calling this function.
+ */
+static struct ust_app_map *find_map_by_objd(struct ust_app *app,
+ int objd)
+{
+ struct lttng_ht_node_ulong *node;
+ struct lttng_ht_iter iter;
+ struct ust_app_map *ua_map = NULL;
+
+ assert(app);
+
+ lttng_ht_lookup(app->ust_map_objd, (void *)((unsigned long) objd), &iter);
+ node = lttng_ht_iter_get_node_ulong(&iter);
+ if (node == NULL) {
+ DBG2("UST app map find by objd %d not found", objd);
+ goto error;
+ }
+
+ ua_map = caa_container_of(node, struct ust_app_map, ust_objd_node);
+
+error:
+ return ua_map;
+}
+
+/*
+ * Reply to a register channel notification from an application on the notify
+ * socket. The channel metadata is also created.
+ *
+ * The session UST registry lock is acquired in this function.
+ *
+ * On success 0 is returned else a negative value.
+ */
+static int reply_ust_register_channel(int sock, int cobjd,
+ size_t nr_fields, struct ustctl_field *fields)
+{
+ int ret, ret_code = 0;
+ uint32_t chan_id;
+ uint64_t chan_reg_key;
+ enum ustctl_channel_header type;
+ struct ust_app *app;
+ struct ust_app_channel *ua_chan;
+ struct ust_app_session *ua_sess;
+ struct ust_registry_session *registry;
+ struct ust_registry_channel *ust_reg_chan;
+
+ rcu_read_lock();
+
+ /* Lookup application. If not found, there is a code flow error. */
+ app = find_app_by_notify_sock(sock);
+ if (!app) {
+ DBG("Application socket %d is being torn down. Abort event notify",
+ sock);
+ ret = 0;
+ goto error_rcu_unlock;
+ }
+
+ /* Lookup channel by UST object descriptor. */
+ ua_chan = find_channel_by_objd(app, cobjd);
+ if (!ua_chan) {
+ DBG("Application channel is being torn down. Abort event notify");
+ ret = 0;
+ goto error_rcu_unlock;
+ }
+
+ assert(ua_chan->session);
+ ua_sess = ua_chan->session;
+
+ /* Get right session registry depending on the session buffer type. */
+ registry = get_session_registry(ua_sess);
+ if (!registry) {
+ DBG("Application session is being torn down. Abort event notify");
+ ret = 0;
+ goto error_rcu_unlock;
+ };
+
+ /* Depending on the buffer type, a different channel key is used. */
+ if (ua_sess->buffer_type == LTTNG_BUFFER_PER_UID) {
+ chan_reg_key = ua_chan->tracing_channel_id;
+ } else {
+ chan_reg_key = ua_chan->key;
+ }
+
+ pthread_mutex_lock(®istry->lock);
+
+ ust_reg_chan = ust_registry_channel_find(registry, chan_reg_key);
+ assert(ust_reg_chan);
+
+ if (!ust_reg_chan->register_done) {
+ /*
+ * TODO: eventually use the registry event count for
+ * this channel to better guess header type for per-pid
+ * buffers.
+ */
+ type = USTCTL_CHANNEL_HEADER_LARGE;
+ ust_reg_chan->nr_ctx_fields = nr_fields;
+ ust_reg_chan->ctx_fields = fields;
+ fields = NULL;
+ ust_reg_chan->header_type = type;
+ } else {
+ /* Get current already assigned values. */
+ type = ust_reg_chan->header_type;
+ }
+ /* Channel id is set during the object creation. */
+ chan_id = ust_reg_chan->chan_id;
+
+ /* Append to metadata */
+ if (!ust_reg_chan->metadata_dumped) {
+ ret_code = ust_metadata_channel_statedump(registry, ust_reg_chan);
+ if (ret_code) {
+ ERR("Error appending channel metadata (errno = %d)", ret_code);
+ goto reply;
+ }
+ }
+
+reply:
+ DBG3("UST app replying to register channel key %" PRIu64
+ " with id %u, type: %d, ret: %d", chan_reg_key, chan_id, type,
+ ret_code);
+
+ ret = ustctl_reply_register_channel(sock, chan_id, type, ret_code);
+ if (ret < 0) {
+ if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
+ ERR("UST app reply channel failed with ret %d", ret);
+ } else {
+ DBG3("UST app reply channel failed. Application died");
+ }
+ goto error;
+ }
+
+ /* This channel registry registration is completed. */
+ ust_reg_chan->register_done = 1;
+
+error:
+ pthread_mutex_unlock(®istry->lock);
+error_rcu_unlock:
+ rcu_read_unlock();
+ free(fields);
+ return ret;
+}
+
+static int add_event_ust_chan_registry(int sock, struct ust_app *ua,
+ struct ust_app_channel *ua_chan, int sobjd, int cobjd, char *name,
+ char *sig, size_t nr_fields, struct ustctl_field *fields,
+ int loglevel_value, char *model_emf_uri)
+{
+ int ret, ret_code;
+ uint32_t event_id = 0;
+ uint64_t chan_reg_key;
+ struct ust_app_session *ua_sess;
+ struct ust_registry_session *registry;
+ /*
+ * The counter index is unused for channel events. It's only used for
+ * map events.
+ */
+ uint64_t counter_index = 0;
+
+ assert(ua_chan->session);
+ ua_sess = ua_chan->session;
+
+ registry = get_session_registry(ua_sess);
+ if (!registry) {
+ DBG("Application session is being torn down. Abort event notify");
+ ret = 0;
+ goto error;
+ }
+
+ if (ua_sess->buffer_type == LTTNG_BUFFER_PER_UID) {
+ chan_reg_key = ua_chan->tracing_channel_id;
+ } else {
+ chan_reg_key = ua_chan->key;
+ }
+
+ pthread_mutex_lock(®istry->lock);
+
+ /*
+ * From this point on, this call acquires the ownership of the sig, fields
+ * and model_emf_uri meaning any free are done inside it if needed. These
+ * three variables MUST NOT be read/write after this.
+ */
+ ret_code = ust_registry_chan_create_event(registry, chan_reg_key,
+ sobjd, cobjd, name, sig, nr_fields, fields,
+ loglevel_value, model_emf_uri, ua_sess->buffer_type,
+ &event_id, ua);
+ sig = NULL;
+ fields = NULL;
+ model_emf_uri = NULL;
+
+ /*
+ * The return value is returned to ustctl so in case of an error, the
+ * application can be notified. In case of an error, it's important not to
+ * return a negative error or else the application will get closed.
+ */
+ ret = ustctl_reply_register_event(sock, event_id, counter_index, ret_code);
+ if (ret < 0) {
+ if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
+ ERR("UST app reply event failed with ret %d", ret);
+ } else {
+ DBG3("UST app reply event failed. Application died");
+ }
+ /*
+ * No need to wipe the create event since the application socket will
+ * get close on error hence cleaning up everything by itself.
+ */
+ goto error;
+ }
+
+ DBG3("UST registry event %s with id %" PRId32 " added successfully",
+ name, event_id);
+
+error:
+ pthread_mutex_unlock(®istry->lock);
+ return ret;
+}
+
+static int add_event_ust_map_registry(int sock, struct ust_app *ua,
+ struct ust_app_map *ua_map, int sobjd, int cobjd, char *name,
+ char *sig, size_t nr_fields, struct ustctl_field *fields,
+ int loglevel_value, char *model_emf_uri, uint64_t tracer_token)
+{
+ int ret, ret_code;
+ uint64_t map_reg_key, counter_index;
+ struct ust_app_session *ua_sess;
+ struct ust_registry_session *registry;
+
+ assert(ua_map->session);
+ ua_sess = ua_map->session;
+
+ registry = get_session_registry(ua_sess);
+ if (!registry) {
+ DBG("Application session is being torn down. Abort event notify");
+ ret = 0;
+ goto error;
+ }
+
+ if (ua_sess->buffer_type == LTTNG_BUFFER_PER_UID) {
+ map_reg_key = ua_map->tracing_map_id;
+ } else {
+ map_reg_key = ua_map->key;
+ }
+
+ pthread_mutex_lock(®istry->lock);
+
+ /*
+ * From this point on, this call acquires the ownership of the sig, fields
+ * and model_emf_uri meaning any free are done inside it if needed. These
+ * three variables MUST NOT be read/write after this.
+ */
+ DBG("Registry_map_create_event on map=%"PRIu64" with token=%"PRIu64,
+ map_reg_key, tracer_token);
+ ret_code = ust_registry_map_create_event(registry, map_reg_key,
+ sobjd, cobjd, name, sig, nr_fields, fields,
+ loglevel_value, model_emf_uri, ua_sess->buffer_type,
+ tracer_token, &counter_index, ua);
+ assert(!ret_code);
+
+ sig = NULL;
+ fields = NULL;
+ model_emf_uri = NULL;
+
+ /*
+ * The return value is returned to ustctl so in case of an error, the
+ * application can be notified. In case of an error, it's important not to
+ * return a negative error or else the application will get closed.
+ */
+ ret = ustctl_reply_register_event(sock, counter_index, counter_index,
+ ret_code);
+ if (ret < 0) {
+ if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
+ ERR("UST app reply event failed with ret %d", ret);
+ } else {
+ DBG3("UST app reply event failed. Application died");
+ }
+ /*
+ * No need to wipe the create event since the application socket will
+ * get close on error hence cleaning up everything by itself.
+ */
+ goto error;
+ }
+
+ DBG3("UST registry map event %s with counter index %" PRIu64 " added successfully",
+ name, counter_index);
+
+error:
+ pthread_mutex_unlock(®istry->lock);
+ return ret;
+}
+
+
+/*
+ * Add event to the UST channel registry. When the event is added to the
+ * registry, the metadata is also created. Once done, this replies to the
+ * application with the appropriate error code.
+ *
+ * The session UST registry lock is acquired in the function.
+ *
+ * On success 0 is returned else a negative value.
+ */
+static int add_event_ust_registry(int sock, int sobjd, int cobjd, char *name,
+ char *sig, size_t nr_fields, struct ustctl_field *fields,
+ int loglevel_value, char *model_emf_uri, uint64_t tracer_token)
+{
+ int ret;
+ struct ust_app *app;
+ struct ust_app_channel *ua_chan = NULL;
+ struct ust_app_map *ua_map = NULL;
+
+ rcu_read_lock();
+
+ /* Lookup application. If not found, there is a code flow error. */
+ app = find_app_by_notify_sock(sock);
+ if (!app) {
+ DBG("Application socket %d is being torn down. Abort event notify",
+ sock);
+ ret = 0;
+ goto end;
+ }
+
+ /* Lookup channel by UST object descriptor. */
+ ua_chan = find_channel_by_objd(app, cobjd);
+ if (ua_chan) {
+ ret = add_event_ust_chan_registry(sock, app, ua_chan, sobjd, cobjd,
+ name, sig, nr_fields, fields, loglevel_value,
+ model_emf_uri);
+ if (ret) {
+ ERR("Error adding channel event to registry: event_name = '%s'", name);
+ }
+ goto found;
+ }
+
+ /* Lookup map by UST object descriptor. */
+ ua_map = find_map_by_objd(app, cobjd);
+ if (ua_map) {
+ ret = add_event_ust_map_registry(sock, app, ua_map, sobjd, cobjd,
+ name, sig, nr_fields, fields, loglevel_value,
+ model_emf_uri, tracer_token);
+ if (ret) {
+ ERR("Error adding map event to registry: event_name = '%s'", name);
+ goto end;
+ }
+ goto found;
+ }
+
+ if (!ua_chan && !ua_map) {
+ DBG("Application event container is being torn down. Abort event notify");
+ ret = 0;
+ goto end;
+ }
+
+found:
+ ret = 0;
+
+end:
+ rcu_read_unlock();
+ return ret;
+}
+
+/*
+ * Add enum to the UST session registry. Once done, this replies to the
+ * application with the appropriate error code.
+ *
+ * The session UST registry lock is acquired within this function.
+ *
+ * On success 0 is returned else a negative value.
+ */
+static int add_enum_ust_registry(int sock, int sobjd, char *name,
+ struct ustctl_enum_entry *entries, size_t nr_entries)
+{
+ int ret = 0, ret_code;
+ struct ust_app *app;
+ struct ust_app_session *ua_sess;
+ struct ust_registry_session *registry;
+ uint64_t enum_id = -1ULL;
+
+ rcu_read_lock();
+
+ /* Lookup application. If not found, there is a code flow error. */
+ app = find_app_by_notify_sock(sock);
+ if (!app) {
+ /* Return an error since this is not an error */
+ DBG("Application socket %d is being torn down. Aborting enum registration",
+ sock);
+ free(entries);
+ goto error_rcu_unlock;
+ }
+
+ /* Lookup session by UST object descriptor. */
+ ua_sess = find_session_by_objd(app, sobjd);
+ if (!ua_sess) {
+ /* Return an error since this is not an error */
+ DBG("Application session is being torn down (session not found). Aborting enum registration.");
+ free(entries);
+ goto error_rcu_unlock;
+ }
+
+ registry = get_session_registry(ua_sess);
+ if (!registry) {
+ DBG("Application session is being torn down (registry not found). Aborting enum registration.");
+ free(entries);
+ goto error_rcu_unlock;
+ }
+
+ pthread_mutex_lock(®istry->lock);
+
+ /*
+ * From this point on, the callee acquires the ownership of
+ * entries. The variable entries MUST NOT be read/written after
+ * call.
+ */
+ ret_code = ust_registry_create_or_find_enum(registry, sobjd, name,
+ entries, nr_entries, &enum_id);
+ entries = NULL;
+
+ /*
+ * The return value is returned to ustctl so in case of an error, the
+ * application can be notified. In case of an error, it's important not to
+ * return a negative error or else the application will get closed.
+ */
+ ret = ustctl_reply_register_enum(sock, enum_id, ret_code);
+ if (ret < 0) {
+ if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
+ ERR("UST app reply enum failed with ret %d", ret);
+ } else {
+ DBG3("UST app reply enum failed. Application died");
+ }
+ /*
+ * No need to wipe the create enum since the application socket will
+ * get close on error hence cleaning up everything by itself.
+ */
+ goto error;
+ }
+
+ DBG3("UST registry enum %s added successfully or already found", name);
+
+error:
+ pthread_mutex_unlock(®istry->lock);
+error_rcu_unlock:
+ rcu_read_unlock();
+ return ret;
+}
+
+/*
+ * Handle application notification through the given notify socket.
+ *
+ * Return 0 on success or else a negative value.
+ */
+int ust_app_recv_notify(int sock)
+{
+ int ret;
+ enum ustctl_notify_cmd cmd;
+
+ DBG3("UST app receiving notify from sock %d", sock);
+
+ ret = ustctl_recv_notify(sock, &cmd);
+ if (ret < 0) {
+ if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
+ ERR("UST app recv notify failed with ret %d", ret);
+ } else {
+ DBG3("UST app recv notify failed. Application died");
+ }
+ goto error;
+ }
+
+ switch (cmd) {
+ case USTCTL_NOTIFY_CMD_EVENT:
+ {
+ int sobjd, cobjd, loglevel_value;
+ char name[LTTNG_UST_SYM_NAME_LEN], *sig, *model_emf_uri;
+ size_t nr_fields;
+ uint64_t tracer_token = 0;
+ struct ustctl_field *fields;
+
+ DBG2("UST app ustctl register event received");
+
+ ret = ustctl_recv_register_event(sock, &sobjd, &cobjd, name,
+ &loglevel_value, &sig, &nr_fields, &fields,
+ &model_emf_uri, &tracer_token);
+ if (ret < 0) {
+ if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
+ ERR("UST app recv event failed with ret %d", ret);
+ } else {
+ DBG3("UST app recv event failed. Application died");
+ }
+ goto error;
+ }
+
+ /*
+ * Add event to the UST registry coming from the notify socket. This
+ * call will free if needed the sig, fields and model_emf_uri. This
+ * code path loses the ownsership of these variables and transfer them
+ * to the this function.
+ */
+ ret = add_event_ust_registry(sock, sobjd, cobjd, name, sig, nr_fields,
+ fields, loglevel_value, model_emf_uri, tracer_token);
+ if (ret < 0) {
+ goto error;
+ }
+
+ break;
+ }
+ case USTCTL_NOTIFY_CMD_CHANNEL:
+ {
+ int sobjd, cobjd;
+ size_t nr_fields;
+ struct ustctl_field *fields;
+
+ DBG2("UST app ustctl register channel received");
+
+ ret = ustctl_recv_register_channel(sock, &sobjd, &cobjd, &nr_fields,
+ &fields);
+ if (ret < 0) {
+ if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
+ ERR("UST app recv channel failed with ret %d", ret);
+ } else {
+ DBG3("UST app recv channel failed. Application died");
+ }
+ goto error;
+ }
+
+ /*
+ * The fields ownership are transfered to this function call meaning
+ * that if needed it will be freed. After this, it's invalid to access
+ * fields or clean it up.
+ */
+ ret = reply_ust_register_channel(sock, cobjd, nr_fields,
+ fields);
+ if (ret < 0) {
+ goto error;
+ }
+
+ break;
+ }
+ case USTCTL_NOTIFY_CMD_ENUM:
+ {
+ int sobjd;
+ char name[LTTNG_UST_SYM_NAME_LEN];
+ size_t nr_entries;
+ struct ustctl_enum_entry *entries;
+
+ DBG2("UST app ustctl register enum received");
+
+ ret = ustctl_recv_register_enum(sock, &sobjd, name,
+ &entries, &nr_entries);
+ if (ret < 0) {
+ if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
+ ERR("UST app recv enum failed with ret %d", ret);
+ } else {
+ DBG3("UST app recv enum failed. Application died");
+ }
+ goto error;
+ }
+
+ /* Callee assumes ownership of entries */
+ ret = add_enum_ust_registry(sock, sobjd, name,
+ entries, nr_entries);
+ if (ret < 0) {
+ goto error;
+ }
+
+ break;
+ }
+ default:
+ /* Should NEVER happen. */
+ assert(0);
+ }
+
+error:
+ return ret;
+}
+
+/*
+ * Once the notify socket hangs up, this is called. First, it tries to find the
+ * corresponding application. On failure, the call_rcu to close the socket is
+ * executed. If an application is found, it tries to delete it from the notify
+ * socket hash table. Whathever the result, it proceeds to the call_rcu.
+ *
+ * Note that an object needs to be allocated here so on ENOMEM failure, the
+ * call RCU is not done but the rest of the cleanup is.
+ */
+void ust_app_notify_sock_unregister(int sock)
+{
+ int err_enomem = 0;