+static void destroy_id_tracker_node_rcu(struct rcu_head *head)
+{
+ struct ust_id_tracker_node *tracker_node = caa_container_of(
+ head, struct ust_id_tracker_node, node.head);
+ free(tracker_node);
+}
+
+static void destroy_id_tracker_node(struct ust_id_tracker_node *tracker_node)
+{
+ call_rcu(&tracker_node->node.head, destroy_id_tracker_node_rcu);
+}
+
+static int init_id_tracker(struct ust_id_tracker *id_tracker)
+{
+ int ret = LTTNG_OK;
+
+ id_tracker->ht = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
+ if (!id_tracker->ht) {
+ ret = LTTNG_ERR_NOMEM;
+ goto end;
+ }
+
+end:
+ return ret;
+}
+
+/*
+ * Teardown id tracker content, but don't free id_tracker object.
+ */
+static void fini_id_tracker(struct ust_id_tracker *id_tracker)
+{
+ struct ust_id_tracker_node *tracker_node;
+ struct lttng_ht_iter iter;
+
+ if (!id_tracker->ht) {
+ return;
+ }
+ rcu_read_lock();
+ cds_lfht_for_each_entry (id_tracker->ht->ht, &iter.iter, tracker_node,
+ node.node) {
+ int ret = lttng_ht_del(id_tracker->ht, &iter);
+
+ assert(!ret);
+ destroy_id_tracker_node(tracker_node);
+ }
+ rcu_read_unlock();
+ ht_cleanup_push(id_tracker->ht);
+ id_tracker->ht = NULL;
+}
+
+static struct ust_id_tracker_node *id_tracker_lookup(
+ struct ust_id_tracker *id_tracker,
+ int id,
+ struct lttng_ht_iter *iter)
+{
+ unsigned long _id = (unsigned long) id;
+ struct lttng_ht_node_ulong *node;
+
+ lttng_ht_lookup(id_tracker->ht, (void *) _id, iter);
+ node = lttng_ht_iter_get_node_ulong(iter);
+ if (node) {
+ return caa_container_of(node, struct ust_id_tracker_node, node);
+ } else {
+ return NULL;
+ }
+}
+
+static int id_tracker_add_id(struct ust_id_tracker *id_tracker, int id)
+{
+ int retval = LTTNG_OK;
+ struct ust_id_tracker_node *tracker_node;
+ struct lttng_ht_iter iter;
+
+ if (id < 0) {
+ retval = LTTNG_ERR_INVALID;
+ goto end;
+ }
+ tracker_node = id_tracker_lookup(id_tracker, id, &iter);
+ if (tracker_node) {
+ /* Already exists. */
+ retval = LTTNG_ERR_PROCESS_ATTR_EXISTS;
+ goto end;
+ }
+ tracker_node = zmalloc(sizeof(*tracker_node));
+ if (!tracker_node) {
+ retval = LTTNG_ERR_NOMEM;
+ goto end;
+ }
+ lttng_ht_node_init_ulong(&tracker_node->node, (unsigned long) id);
+ lttng_ht_add_unique_ulong(id_tracker->ht, &tracker_node->node);
+end:
+ return retval;
+}
+
+static int id_tracker_del_id(struct ust_id_tracker *id_tracker, int id)
+{
+ int retval = LTTNG_OK, ret;
+ struct ust_id_tracker_node *tracker_node;
+ struct lttng_ht_iter iter;
+
+ if (id < 0) {
+ retval = LTTNG_ERR_INVALID;
+ goto end;
+ }
+ tracker_node = id_tracker_lookup(id_tracker, id, &iter);
+ if (!tracker_node) {
+ /* Not found */
+ retval = LTTNG_ERR_PROCESS_ATTR_MISSING;
+ goto end;
+ }
+ ret = lttng_ht_del(id_tracker->ht, &iter);
+ assert(!ret);
+
+ destroy_id_tracker_node(tracker_node);
+end:
+ return retval;
+}
+
+static struct ust_id_tracker *get_id_tracker(struct ltt_ust_session *session,
+ enum lttng_process_attr process_attr)
+{
+ switch (process_attr) {
+ case LTTNG_PROCESS_ATTR_VIRTUAL_PROCESS_ID:
+ return &session->vpid_tracker;
+ case LTTNG_PROCESS_ATTR_VIRTUAL_USER_ID:
+ return &session->vuid_tracker;
+ case LTTNG_PROCESS_ATTR_VIRTUAL_GROUP_ID:
+ return &session->vgid_tracker;
+ default:
+ return NULL;
+ }
+}
+
+static struct process_attr_tracker *_trace_ust_get_process_attr_tracker(
+ struct ltt_ust_session *session,
+ enum lttng_process_attr process_attr)
+{
+ switch (process_attr) {
+ case LTTNG_PROCESS_ATTR_VIRTUAL_PROCESS_ID:
+ return session->tracker_vpid;
+ case LTTNG_PROCESS_ATTR_VIRTUAL_USER_ID:
+ return session->tracker_vuid;
+ case LTTNG_PROCESS_ATTR_VIRTUAL_GROUP_ID:
+ return session->tracker_vgid;
+ default:
+ return NULL;
+ }
+}
+
+const struct process_attr_tracker *trace_ust_get_process_attr_tracker(
+ struct ltt_ust_session *session,
+ enum lttng_process_attr process_attr)
+{
+ return (const struct process_attr_tracker *)
+ _trace_ust_get_process_attr_tracker(
+ session, process_attr);
+}
+
+/*
+ * The session lock is held when calling this function.
+ */
+int trace_ust_id_tracker_lookup(enum lttng_process_attr process_attr,
+ struct ltt_ust_session *session,
+ int id)
+{
+ struct lttng_ht_iter iter;
+ struct ust_id_tracker *id_tracker;
+
+ id_tracker = get_id_tracker(session, process_attr);
+ if (!id_tracker) {
+ abort();
+ }
+ if (!id_tracker->ht) {
+ return 1;
+ }
+ if (id_tracker_lookup(id_tracker, id, &iter)) {
+ return 1;
+ }
+ return 0;
+}
+
+/*
+ * Called with the session lock held.
+ */
+enum lttng_error_code trace_ust_process_attr_tracker_set_tracking_policy(
+ struct ltt_ust_session *session,
+ enum lttng_process_attr process_attr,
+ enum lttng_tracking_policy policy)
+{
+ int ret;
+ enum lttng_error_code ret_code = LTTNG_OK;
+ struct ust_id_tracker *id_tracker =
+ get_id_tracker(session, process_attr);
+ struct process_attr_tracker *tracker =
+ _trace_ust_get_process_attr_tracker(
+ session, process_attr);
+ bool should_update_apps = false;
+ enum lttng_tracking_policy previous_policy;
+
+ if (!tracker) {
+ ret_code = LTTNG_ERR_INVALID;
+ goto end;
+ }
+
+ previous_policy = process_attr_tracker_get_tracking_policy(tracker);
+ ret = process_attr_tracker_set_tracking_policy(tracker, policy);
+ if (ret) {
+ ret_code = LTTNG_ERR_UNK;
+ goto end;
+ }
+
+ if (previous_policy == policy) {
+ goto end;
+ }
+
+ switch (policy) {
+ case LTTNG_TRACKING_POLICY_INCLUDE_ALL:
+ /* Track all values: destroy tracker if exists. */
+ if (id_tracker->ht) {
+ fini_id_tracker(id_tracker);
+ /* Ensure all apps have session. */
+ should_update_apps = true;
+ }
+ break;
+ case LTTNG_TRACKING_POLICY_EXCLUDE_ALL:
+ case LTTNG_TRACKING_POLICY_INCLUDE_SET:
+ /* fall-through. */
+ fini_id_tracker(id_tracker);
+ ret_code = init_id_tracker(id_tracker);
+ if (ret_code != LTTNG_OK) {
+ ERR("Error initializing ID tracker");
+ goto end;
+ }
+ /* Remove all apps from session. */
+ should_update_apps = true;
+ break;
+ default:
+ abort();
+ }
+ if (should_update_apps && session->active) {
+ ust_app_global_update_all(session);
+ }
+end:
+ return ret_code;
+}
+
+/* Called with the session lock held. */
+enum lttng_error_code trace_ust_process_attr_tracker_inclusion_set_add_value(
+ struct ltt_ust_session *session,
+ enum lttng_process_attr process_attr,
+ const struct process_attr_value *value)
+{
+ enum lttng_error_code ret_code = LTTNG_OK;
+ bool should_update_apps = false;
+ struct ust_id_tracker *id_tracker =
+ get_id_tracker(session, process_attr);
+ struct process_attr_tracker *tracker;
+ int integral_value;
+ enum process_attr_tracker_status status;
+ struct ust_app *app;
+
+ /*
+ * Convert process attribute tracker value to the integral
+ * representation required by the kern-ctl API.
+ */
+ switch (process_attr) {
+ case LTTNG_PROCESS_ATTR_PROCESS_ID:
+ case LTTNG_PROCESS_ATTR_VIRTUAL_PROCESS_ID:
+ integral_value = (int) value->value.pid;
+ break;
+ case LTTNG_PROCESS_ATTR_USER_ID:
+ case LTTNG_PROCESS_ATTR_VIRTUAL_USER_ID:
+ if (value->type == LTTNG_PROCESS_ATTR_VALUE_TYPE_USER_NAME) {
+ uid_t uid;
+
+ ret_code = utils_user_id_from_name(
+ value->value.user_name, &uid);
+ if (ret_code != LTTNG_OK) {
+ goto end;
+ }
+ integral_value = (int) uid;
+ } else {
+ integral_value = (int) value->value.uid;
+ }
+ break;
+ case LTTNG_PROCESS_ATTR_GROUP_ID:
+ case LTTNG_PROCESS_ATTR_VIRTUAL_GROUP_ID:
+ if (value->type == LTTNG_PROCESS_ATTR_VALUE_TYPE_GROUP_NAME) {
+ gid_t gid;
+
+ ret_code = utils_group_id_from_name(
+ value->value.group_name, &gid);
+ if (ret_code != LTTNG_OK) {
+ goto end;
+ }
+ integral_value = (int) gid;
+ } else {
+ integral_value = (int) value->value.gid;
+ }
+ break;
+ default:
+ ret_code = LTTNG_ERR_INVALID;
+ goto end;
+ }
+
+ tracker = _trace_ust_get_process_attr_tracker(session, process_attr);
+ if (!tracker) {
+ ret_code = LTTNG_ERR_INVALID;
+ goto end;
+ }
+
+ status = process_attr_tracker_inclusion_set_add_value(tracker, value);
+ if (status != PROCESS_ATTR_TRACKER_STATUS_OK) {
+ switch (status) {
+ case PROCESS_ATTR_TRACKER_STATUS_EXISTS:
+ ret_code = LTTNG_ERR_PROCESS_ATTR_EXISTS;
+ break;
+ case PROCESS_ATTR_TRACKER_STATUS_INVALID_TRACKING_POLICY:
+ ret_code = LTTNG_ERR_PROCESS_ATTR_TRACKER_INVALID_TRACKING_POLICY;
+ break;
+ case PROCESS_ATTR_TRACKER_STATUS_ERROR:
+ default:
+ ret_code = LTTNG_ERR_UNK;
+ break;
+ }
+ goto end;
+ }
+
+ DBG("User space track %s %d for session id %" PRIu64,
+ lttng_process_attr_to_string(process_attr),
+ integral_value, session->id);
+
+ ret_code = id_tracker_add_id(id_tracker, integral_value);
+ if (ret_code != LTTNG_OK) {
+ goto end;
+ }
+ /* Add session to application */
+ switch (process_attr) {
+ case LTTNG_PROCESS_ATTR_VIRTUAL_PROCESS_ID:
+ app = ust_app_find_by_pid(integral_value);
+ if (app) {
+ should_update_apps = true;
+ }
+ break;
+ default:
+ should_update_apps = true;
+ break;
+ }
+ if (should_update_apps && session->active) {
+ ust_app_global_update_all(session);
+ }
+end:
+ return ret_code;
+}
+
+/* Called with the session lock held. */
+enum lttng_error_code trace_ust_process_attr_tracker_inclusion_set_remove_value(
+ struct ltt_ust_session *session,
+ enum lttng_process_attr process_attr,
+ const struct process_attr_value *value)
+{
+ enum lttng_error_code ret_code = LTTNG_OK;
+ bool should_update_apps = false;
+ struct ust_id_tracker *id_tracker =
+ get_id_tracker(session, process_attr);
+ struct process_attr_tracker *tracker;
+ int integral_value;
+ enum process_attr_tracker_status status;
+ struct ust_app *app;
+
+ /*
+ * Convert process attribute tracker value to the integral
+ * representation required by the kern-ctl API.
+ */
+ switch (process_attr) {
+ case LTTNG_PROCESS_ATTR_PROCESS_ID:
+ case LTTNG_PROCESS_ATTR_VIRTUAL_PROCESS_ID:
+ integral_value = (int) value->value.pid;
+ break;
+ case LTTNG_PROCESS_ATTR_USER_ID:
+ case LTTNG_PROCESS_ATTR_VIRTUAL_USER_ID:
+ if (value->type == LTTNG_PROCESS_ATTR_VALUE_TYPE_USER_NAME) {
+ uid_t uid;
+
+ ret_code = utils_user_id_from_name(
+ value->value.user_name, &uid);
+ if (ret_code != LTTNG_OK) {
+ goto end;
+ }
+ integral_value = (int) uid;
+ } else {
+ integral_value = (int) value->value.uid;
+ }
+ break;
+ case LTTNG_PROCESS_ATTR_GROUP_ID:
+ case LTTNG_PROCESS_ATTR_VIRTUAL_GROUP_ID:
+ if (value->type == LTTNG_PROCESS_ATTR_VALUE_TYPE_GROUP_NAME) {
+ gid_t gid;
+
+ ret_code = utils_group_id_from_name(
+ value->value.group_name, &gid);
+ if (ret_code != LTTNG_OK) {
+ goto end;
+ }
+ integral_value = (int) gid;
+ } else {
+ integral_value = (int) value->value.gid;
+ }
+ break;
+ default:
+ ret_code = LTTNG_ERR_INVALID;
+ goto end;
+ }
+
+ tracker = _trace_ust_get_process_attr_tracker(session, process_attr);
+ if (!tracker) {
+ ret_code = LTTNG_ERR_INVALID;
+ goto end;
+ }
+
+ status = process_attr_tracker_inclusion_set_remove_value(
+ tracker, value);
+ if (status != PROCESS_ATTR_TRACKER_STATUS_OK) {
+ switch (status) {
+ case PROCESS_ATTR_TRACKER_STATUS_MISSING:
+ ret_code = LTTNG_ERR_PROCESS_ATTR_MISSING;
+ break;
+ case PROCESS_ATTR_TRACKER_STATUS_INVALID_TRACKING_POLICY:
+ ret_code = LTTNG_ERR_PROCESS_ATTR_TRACKER_INVALID_TRACKING_POLICY;
+ break;
+ case PROCESS_ATTR_TRACKER_STATUS_ERROR:
+ default:
+ ret_code = LTTNG_ERR_UNK;
+ break;
+ }
+ goto end;
+ }
+
+ DBG("User space untrack %s %d for session id %" PRIu64,
+ lttng_process_attr_to_string(process_attr),
+ integral_value, session->id);
+
+ ret_code = id_tracker_del_id(id_tracker, integral_value);
+ if (ret_code != LTTNG_OK) {
+ goto end;
+ }
+ /* Add session to application */
+ switch (process_attr) {
+ case LTTNG_PROCESS_ATTR_VIRTUAL_PROCESS_ID:
+ app = ust_app_find_by_pid(integral_value);
+ if (app) {
+ should_update_apps = true;
+ }
+ break;
+ default:
+ should_update_apps = true;
+ break;
+ }
+ if (should_update_apps && session->active) {
+ ust_app_global_update_all(session);
+ }
+end:
+ return ret_code;
+}
+