+
+enum lttng_error_code kernel_create_trigger_group_notification_fd(
+ int *trigger_group_notification_fd)
+{
+ enum lttng_error_code error_code_ret;
+ int local_fd = -1, ret;
+
+ assert(trigger_group_notification_fd);
+
+ ret = kernctl_create_trigger_group_notification_fd(kernel_tracer_trigger_group_fd);
+ if (ret < 0) {
+ PERROR("ioctl kernel create trigger group");
+ error_code_ret = LTTNG_ERR_TRIGGER_GROUP_NOTIFICATION_FD;
+ goto error;
+ }
+
+ /* Store locally */
+ local_fd = ret;
+
+ /* Prevent fd duplication after execlp() */
+ ret = fcntl(local_fd, F_SETFD, FD_CLOEXEC);
+ if (ret < 0) {
+ PERROR("fcntl session fd");
+ error_code_ret = LTTNG_ERR_TRIGGER_GROUP_NOTIFICATION_FD;
+ goto error;
+ }
+
+ DBG("Kernel trigger group notification created (fd: %d)",
+ local_fd);
+ error_code_ret = LTTNG_OK;
+ *trigger_group_notification_fd = local_fd;
+
+error:
+ return error_code_ret;
+}
+
+enum lttng_error_code kernel_create_trigger_group_error_counter(
+ int *error_counter_fd, size_t nb_bucket)
+{
+ enum lttng_error_code error_code_ret;
+ int local_fd = -1, ret;
+ struct lttng_kernel_counter_conf error_counter_conf;
+
+ assert(error_counter_fd);
+
+ error_counter_conf.arithmetic = LTTNG_KERNEL_COUNTER_ARITHMETIC_MODULAR;
+ error_counter_conf.bitness = LTTNG_KERNEL_COUNTER_BITNESS_64BITS;
+ error_counter_conf.global_sum_step = 0;
+ error_counter_conf.number_dimensions = 1;
+ error_counter_conf.dimensions[0].size = nb_bucket;
+ error_counter_conf.dimensions[0].has_underflow = false;
+ error_counter_conf.dimensions[0].has_overflow = false;
+
+ ret = kernctl_create_trigger_group_error_counter(
+ kernel_tracer_trigger_group_fd, &error_counter_conf);
+ if (ret < 0) {
+ PERROR("ioctl kernel create trigger group error counter");
+ error_code_ret = LTTNG_ERR_TRIGGER_GROUP_ERROR_COUNTER;
+ goto error;
+ }
+
+ /* Store locally */
+ local_fd = ret;
+
+ /* Prevent fd duplication after execlp() */
+ ret = fcntl(local_fd, F_SETFD, FD_CLOEXEC);
+ if (ret < 0) {
+ error_code_ret = LTTNG_ERR_TRIGGER_GROUP_ERROR_COUNTER;
+ PERROR("fcntl session fd");
+ }
+
+ DBG("Kernel trigger group error counter (fd: %d)",
+ local_fd);
+ error_code_ret = LTTNG_OK;
+
+error:
+ *error_counter_fd = local_fd;
+ return error_code_ret;
+}
+
+enum lttng_error_code kernel_destroy_trigger_group_notification_fd(
+ int trigger_group_notification_fd)
+{
+ enum lttng_error_code ret = LTTNG_OK;
+ DBG("Closing trigger group notification fd %d", trigger_group_notification_fd);
+ if (trigger_group_notification_fd >= 0) {
+ ret = close(trigger_group_notification_fd);
+ if (ret) {
+ PERROR("close");
+ }
+ }
+ return ret;
+}
+
+static
+unsigned long hash_trigger(struct lttng_trigger *trigger)
+{
+ const struct lttng_condition *condition =
+ lttng_trigger_get_const_condition(trigger);
+ return lttng_condition_hash(condition);
+}
+
+static
+int match_trigger(struct cds_lfht_node *node, const void *key)
+{
+ struct ltt_kernel_token_event_rule *token;
+ const struct lttng_trigger *trigger = key;
+
+ token = caa_container_of(node, struct ltt_kernel_token_event_rule, ht_node);
+
+ return lttng_trigger_is_equal(trigger, token->trigger);
+}
+
+static enum lttng_error_code kernel_create_token_event_rule(struct lttng_trigger *trigger,
+ const struct lttng_credentials *creds, uint64_t token)
+{
+ int err, fd, ret = 0;
+ enum lttng_error_code error_code_ret;
+ struct ltt_kernel_token_event_rule *event;
+ struct lttng_kernel_trigger kernel_trigger = {};
+ unsigned int capture_bytecode_count = 0;
+ struct lttng_condition *condition = NULL;
+ struct lttng_event_rule *event_rule = NULL;
+
+ assert(trigger);
+
+ condition = lttng_trigger_get_condition(trigger);
+ assert(condition);
+ assert(lttng_condition_get_type(condition) == LTTNG_CONDITION_TYPE_EVENT_RULE_HIT);
+
+ lttng_condition_event_rule_get_rule_mutable(condition, &event_rule);
+ assert(event_rule);
+ assert(lttng_event_rule_get_type(event_rule) != LTTNG_EVENT_RULE_TYPE_UNKNOWN);
+
+ error_code_ret = trace_kernel_create_token_event_rule(trigger, token,
+ lttng_trigger_get_error_counter_index(trigger), &event);
+ if (error_code_ret != LTTNG_OK) {
+ goto error;
+ }
+
+ trace_kernel_init_trigger_from_event_rule(event_rule, &kernel_trigger);
+ kernel_trigger.id = event->token;
+ kernel_trigger.error_counter_idx = lttng_trigger_get_error_counter_index(trigger);
+
+ fd = kernctl_create_trigger(kernel_tracer_trigger_group_fd, &kernel_trigger);
+ if (fd < 0) {
+ switch (-fd) {
+ case EEXIST:
+ error_code_ret = LTTNG_ERR_KERN_EVENT_EXIST;
+ break;
+ case ENOSYS:
+ WARN("Trigger type not implemented");
+ error_code_ret = LTTNG_ERR_KERN_EVENT_ENOSYS;
+ break;
+ case ENOENT:
+ WARN("Event %s not found!", kernel_trigger.name);
+ error_code_ret = LTTNG_ERR_KERN_ENABLE_FAIL;
+ break;
+ default:
+ error_code_ret = LTTNG_ERR_KERN_ENABLE_FAIL;
+ PERROR("create trigger ioctl");
+ }
+ goto free_event;
+ }
+
+ event->fd = fd;
+ /* Prevent fd duplication after execlp() */
+ err = fcntl(event->fd, F_SETFD, FD_CLOEXEC);
+ if (err < 0) {
+ PERROR("fcntl session fd");
+ }
+
+ if (event->filter) {
+ err = kernctl_filter(event->fd, event->filter);
+ if (err < 0) {
+ switch (-err) {
+ case ENOMEM:
+ error_code_ret = LTTNG_ERR_FILTER_NOMEM;
+ break;
+ default:
+ error_code_ret = LTTNG_ERR_FILTER_INVAL;
+ break;
+ }
+ goto filter_error;
+ }
+ }
+
+ if (lttng_event_rule_get_type(event_rule) ==
+ LTTNG_EVENT_RULE_TYPE_UPROBE) {
+ ret = userspace_probe_event_rule_add_callsites(
+ event_rule, creds, event->fd);
+ if (ret) {
+ error_code_ret = LTTNG_ERR_KERN_ENABLE_FAIL;
+ goto add_callsite_error;
+ }
+ }
+
+ /* Set the capture bytecode */
+ capture_bytecode_count = lttng_trigger_get_capture_bytecode_count(trigger);
+ for (unsigned int i = 0; i < capture_bytecode_count; i++) {
+ const struct lttng_bytecode *capture_bytecode = lttng_trigger_get_capture_bytecode_at_index(trigger, i);
+ ret = kernctl_capture(event->fd, capture_bytecode);
+ if (ret < 0) {
+ error_code_ret = LTTNG_ERR_KERN_ENABLE_FAIL;
+ goto error;
+ }
+ }
+
+ err = kernctl_enable(event->fd);
+ if (err < 0) {
+ switch (-err) {
+ case EEXIST:
+ error_code_ret = LTTNG_ERR_KERN_EVENT_EXIST;
+ break;
+ default:
+ PERROR("enable kernel trigger");
+ error_code_ret = LTTNG_ERR_KERN_ENABLE_FAIL;
+ break;
+ }
+ goto enable_error;
+ }
+
+ /* Add trigger to kernel token mapping in the hashtable. */
+ cds_lfht_add(kernel_tracer_token_ht, hash_trigger(trigger),
+ &event->ht_node);
+
+ DBG("Trigger %s created (fd: %d)", kernel_trigger.name, event->fd);
+
+ return LTTNG_OK;
+
+add_callsite_error:
+enable_error:
+filter_error:
+ {
+ int closeret;
+
+ closeret = close(event->fd);
+ if (closeret) {
+ PERROR("close event fd");
+ }
+ }
+free_event:
+ free(event);
+error:
+ return error_code_ret;
+}
+
+enum lttng_error_code kernel_register_trigger(struct lttng_trigger *trigger, const struct lttng_credentials *cmd_creds)
+{
+ enum lttng_error_code ret;
+ struct lttng_condition *condition;
+ struct lttng_event_rule *event_rule;
+ uint64_t token;
+
+ /* TODO error handling */
+
+ rcu_read_lock();
+ pthread_mutex_lock(¬ification_trigger_tokens_ht_lock);
+
+ /* TODO: error checking and type checking */
+ token = lttng_trigger_get_tracer_token(trigger);
+ condition = lttng_trigger_get_condition(trigger);
+ (void) lttng_condition_event_rule_get_rule_mutable(condition, &event_rule);
+
+ assert(lttng_event_rule_get_domain_type(event_rule) == LTTNG_DOMAIN_KERNEL);
+
+ ret = kernel_create_token_event_rule(trigger, cmd_creds, token);
+ if (ret != LTTNG_OK) {
+ ERR("Failed to create kernel trigger token.");
+ }
+
+ rcu_read_unlock();
+ pthread_mutex_unlock(¬ification_trigger_tokens_ht_lock);
+ return ret;
+}
+
+enum lttng_error_code kernel_unregister_trigger(struct lttng_trigger *trigger)
+{
+ struct ltt_kernel_token_event_rule *token_event_rule_element;
+ struct cds_lfht_node *node;
+ struct cds_lfht_iter iter;
+ enum lttng_error_code error_code_ret;
+ int ret;
+
+ rcu_read_lock();
+ pthread_mutex_unlock(¬ification_trigger_tokens_ht_lock);
+
+ cds_lfht_lookup(kernel_tracer_token_ht, hash_trigger(trigger),
+ match_trigger, trigger, &iter);
+ node = cds_lfht_iter_get_node(&iter);
+ if (!node) {
+ error_code_ret = LTTNG_ERR_TRIGGER_NOT_FOUND;
+ goto error;
+ }
+
+ token_event_rule_element = caa_container_of(node,
+ struct ltt_kernel_token_event_rule, ht_node);
+
+ ret = kernel_disable_token_event_rule(token_event_rule_element);
+ if (ret) {
+ error_code_ret = LTTNG_ERR_FATAL;
+ goto error;
+ }
+
+ trace_kernel_destroy_token_event_rule(token_event_rule_element);
+
+ rcu_read_unlock();
+ pthread_mutex_unlock(¬ification_trigger_tokens_ht_lock);
+
+ error_code_ret = LTTNG_OK;
+
+error:
+ return error_code_ret;
+}
+
+int kernel_get_notification_fd(void)
+{
+ return kernel_tracer_trigger_group_notification_fd;
+}