Fix: sessiond: leak of trigger on registration error

[lttng-tools.git] / src / bin / lttng-sessiond / cmd.c

diff --git a/src/bin/lttng-sessiond/cmd.c b/src/bin/lttng-sessiond/cmd.c
index 2ba825da006cae03d2bb5a8ab396d4642843f5df..8d36e7192c8deb32a46ca471c5d58dafd5e19d63 100644 (file)
--- a/src/bin/lttng-sessiond/cmd.c
+++ b/src/bin/lttng-sessiond/cmd.c
@@ -488,7 +488,7 @@ static int list_lttng_agent_events(struct agent *agt,
        cds_lfht_for_each_entry (
                        agt->events->ht, &iter.iter, agent_event, node.node) {
                struct lttng_event event = {
-                       .enabled = agent_event->enabled,
+                       .enabled = AGENT_EVENT_IS_ENABLED(agent_event),
                        .loglevel = agent_event->loglevel_value,
                        .loglevel_type = agent_event->loglevel_type,
                };
@@ -4317,7 +4317,7 @@ enum lttng_error_code cmd_register_trigger(const struct lttng_credentials *cmd_c
                struct lttng_trigger **return_trigger)
 {
        enum lttng_error_code ret_code;
-       bool must_update_event_notifier;
+       bool must_update_event_notifiers;
        const char *trigger_name;
        uid_t trigger_owner;
        enum lttng_trigger_status trigger_status;
@@ -4377,27 +4377,31 @@ enum lttng_error_code cmd_register_trigger(const struct lttng_credentials *cmd_c
        if (ret_code != LTTNG_OK) {
                DBG("Failed to register trigger to notification thread: trigger name = '%s', trigger owner uid = %d, error code = %d",
                                trigger_name, (int) trigger_owner, ret_code);
-               goto end_notification_thread;
+               goto end;
        }
 
        trigger_status = lttng_trigger_get_name(trigger, &trigger_name);
        trigger_name = trigger_status == LTTNG_TRIGGER_STATUS_OK ?
                        trigger_name : "(unnamed)";
 
-       ret_code = trigger_modifies_event_notifier(trigger, &must_update_event_notifier);
+       ret_code = trigger_modifies_event_notifier(trigger, &must_update_event_notifiers);
        if (ret_code != LTTNG_OK) {
                ERR("Failed to determine if event modifies event notifiers: trigger name = '%s', trigger owner uid = %d, error code = %d",
                                trigger_name, (int) trigger_owner, ret_code);
-               goto end_notification_thread;
+               goto end;
        }
 
        /*
         * Synchronize tracers if the trigger adds an event notifier.
         */
-       if (must_update_event_notifier) {
-               if (lttng_trigger_get_underlying_domain_type_restriction(
-                                   trigger) == LTTNG_DOMAIN_KERNEL) {
+       if (must_update_event_notifiers) {
+               const enum lttng_domain_type trigger_domain =
+                               lttng_trigger_get_underlying_domain_type_restriction(trigger);
 
+               session_lock_list();
+               switch (trigger_domain) {
+               case LTTNG_DOMAIN_KERNEL:
+               {
                        ret_code = kernel_register_event_notifier(
                                        trigger, cmd_creds);
                        if (ret_code != LTTNG_OK) {
@@ -4413,12 +4417,39 @@ enum lttng_error_code cmd_register_trigger(const struct lttng_credentials *cmd_c
                                                        (int) trigger_owner,
                                                        ret_code);
                                }
-
-                               goto end;
                        }
-               } else {
+                       break;
+               }
+               case LTTNG_DOMAIN_UST:
                        ust_app_global_update_all_event_notifier_rules();
+                       break;
+               case LTTNG_DOMAIN_NONE:
+                       abort();
+               default:
+               {
+                       /* Agent domains. */
+                       struct agent *agt = agent_find_by_event_notifier_domain(
+                                       trigger_domain);
+
+                       if (!agt) {
+                               agt = agent_create(trigger_domain);
+                               if (!agt) {
+                                       ret_code = LTTNG_ERR_NOMEM;
+                                       goto end_unlock_session_list;
+                               }
+                               agent_add(agt, trigger_agents_ht_by_domain);
+                       }
+
+                       ret_code = trigger_agent_enable(trigger, agt);
+                       if (ret_code != LTTNG_OK) {
+                               goto end_unlock_session_list;
+                       }
+
+                       break;
+               }
                }
+
+               session_unlock_list();
        }
 
        /*
@@ -4428,14 +4459,17 @@ enum lttng_error_code cmd_register_trigger(const struct lttng_credentials *cmd_c
         * reference to the trigger so the caller doesn't have to care if those
         * are distinct instances or not.
         */
-       lttng_trigger_get(trigger);
-       *return_trigger = trigger;
-
-end_notification_thread:
-       /* Ownership of trigger was transferred. */
-       trigger = NULL;
+       if (ret_code == LTTNG_OK) {
+               lttng_trigger_get(trigger);
+               *return_trigger = trigger;
+               /* Ownership of trigger was transferred to caller. */
+               trigger = NULL;
+       }
 end:
        return ret_code;
+end_unlock_session_list:
+       session_unlock_list();
+       return ret_code;
 }
 
 enum lttng_error_code cmd_unregister_trigger(const struct lttng_credentials *cmd_creds,
@@ -4443,7 +4477,7 @@ enum lttng_error_code cmd_unregister_trigger(const struct lttng_credentials *cmd
                struct notification_thread_handle *notification_thread)
 {
        enum lttng_error_code ret_code;
-       bool must_update_event_notifier;
+       bool must_update_event_notifiers;
        const char *trigger_name;
        uid_t trigger_owner;
        enum lttng_trigger_status trigger_status;
@@ -4475,7 +4509,7 @@ enum lttng_error_code cmd_unregister_trigger(const struct lttng_credentials *cmd
                }
        }
 
-       ret_code = trigger_modifies_event_notifier(trigger, &must_update_event_notifier);
+       ret_code = trigger_modifies_event_notifier(trigger, &must_update_event_notifiers);
        if (ret_code != LTTNG_OK) {
                ERR("Failed to determine if event modifies event notifiers: trigger name = '%s', trigger owner uid = %d, error code = %d",
                                trigger_name, (int) trigger_owner, ret_code);
@@ -4491,21 +4525,60 @@ enum lttng_error_code cmd_unregister_trigger(const struct lttng_credentials *cmd
 
        /*
         * Synchronize tracers if the trigger removes an event notifier.
+        * Do this even if the trigger unregistration failed to at least stop
+        * the tracers from producing notifications associated with this
+        * event notifier.
         */
-       if (must_update_event_notifier) {
-               if (lttng_trigger_get_underlying_domain_type_restriction(
-                                   trigger) == LTTNG_DOMAIN_KERNEL) {
-
+       if (must_update_event_notifiers) {
+               const enum lttng_domain_type trigger_domain =
+                               lttng_trigger_get_underlying_domain_type_restriction(
+                                               trigger);
+
+               session_lock_list();
+               switch (trigger_domain) {
+               case LTTNG_DOMAIN_KERNEL:
+               {
                        ret_code = kernel_unregister_event_notifier(
                                        trigger);
-               } else {
+                       break;
+               }
+               case LTTNG_DOMAIN_UST:
                        ust_app_global_update_all_event_notifier_rules();
+                       break;
+               case LTTNG_DOMAIN_NONE:
+                       abort();
+               default:
+               {
+                       /* Agent domains. */
+                       struct agent *agt = agent_find_by_event_notifier_domain(
+                                       trigger_domain);
+
+                       if (!agt) {
+                               agt = agent_create(trigger_domain);
+                               if (!agt) {
+                                       ret_code = LTTNG_ERR_NOMEM;
+                                       goto end_unlock_session_list;
+                               }
+                               agent_add(agt, trigger_agents_ht_by_domain);
+                       }
+
+                       ret_code = trigger_agent_disable(trigger, agt);
+                       if (ret_code != LTTNG_OK) {
+                               goto end_unlock_session_list;
+                       }
+
+                       break;
+               }
                }
+
+               session_unlock_list();
        }
 
 end:
        return ret_code;
-}
+end_unlock_session_list:
+       session_unlock_list();
+       return ret_code;}
 
 int cmd_list_triggers(struct command_ctx *cmd_ctx,
                struct notification_thread_handle *notification_thread,