Fix: double RCU unlock on event_agent_disable_all

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

diff --git a/src/bin/lttng-sessiond/event.c b/src/bin/lttng-sessiond/event.c
index 71b66a8468cd06410ca3e277fa63750d9b0780df..8cca21391d43dd9b20b877bc920e14d10c1a348e 100644 (file)
--- a/src/bin/lttng-sessiond/event.c
+++ b/src/bin/lttng-sessiond/event.c
@@ -412,10 +412,11 @@ int event_agent_enable(struct ltt_ust_session *usess,
                        usess->id, event->loglevel_type, event->loglevel,
                        filter_expression ? filter_expression : "NULL");
 
-       aevent = agent_find_event(event->name, event->loglevel, agt);
+       aevent = agent_find_event(event->name, event->loglevel_type,
+               event->loglevel, agt);
        if (!aevent) {
-               aevent = agent_create_event(event->name, event->loglevel,
-                               event->loglevel_type, filter,
+               aevent = agent_create_event(event->name, event->loglevel_type,
+                               event->loglevel, filter,
                                filter_expression);
                if (!aevent) {
                        ret = LTTNG_ERR_NOMEM;
@@ -475,30 +476,26 @@ const char *event_get_default_agent_ust_name(enum lttng_domain_type domain)
 }
 
 /*
- * Disable a single agent event for a given UST session.
+ * Disable a given agent event for a given UST session.
  *
+ * Must be called with the RCU read lock held.
  * Return LTTNG_OK on success or else a LTTNG_ERR* code.
  */
-int event_agent_disable(struct ltt_ust_session *usess, struct agent *agt,
-               char *event_name)
+static int event_agent_disable_one(struct ltt_ust_session *usess,
+               struct agent *agt, struct agent_event *aevent)
 {
        int ret;
-       struct agent_event *aevent;
        struct ltt_ust_event *uevent = NULL;
        struct ltt_ust_channel *uchan = NULL;
        const char *ust_event_name, *ust_channel_name;
 
        assert(agt);
        assert(usess);
-       assert(event_name);
+       assert(aevent);
 
-       DBG("Event agent disabling %s for session %" PRIu64, event_name, usess->id);
-
-       aevent = agent_find_event_by_name(event_name, agt);
-       if (!aevent) {
-               ret = LTTNG_ERR_UST_EVENT_NOT_FOUND;
-               goto error;
-       }
+       DBG("Event agent disabling %s (loglevel type %d, loglevel value %d) for session %" PRIu64,
+               aevent->name, aevent->loglevel_type, aevent->loglevel_value,
+               usess->id);
 
        /* Already disabled? */
        if (!aevent->enabled) {
@@ -567,6 +564,52 @@ end:
 error:
        return ret;
 }
+
+/*
+ * Disable all agent events matching a given name for a given UST session.
+ *
+ * Return LTTNG_OK on success or else a LTTNG_ERR* code.
+ */
+int event_agent_disable(struct ltt_ust_session *usess, struct agent *agt,
+               char *event_name)
+{
+       int ret = LTTNG_OK;
+       struct agent_event *aevent;
+       struct lttng_ht_iter iter;
+       struct lttng_ht_node_str *node;
+
+       assert(agt);
+       assert(usess);
+       assert(event_name);
+
+       DBG("Event agent disabling %s (all loglevels) for session %" PRIu64, event_name, usess->id);
+
+       rcu_read_lock();
+       agent_find_events_by_name(event_name, agt, &iter);
+       node = lttng_ht_iter_get_node_str(&iter);
+
+       if (node == NULL) {
+               DBG2("Event agent NOT found by name %s", event_name);
+               ret = LTTNG_ERR_UST_EVENT_NOT_FOUND;
+               goto end;
+       }
+
+       do {
+               aevent = caa_container_of(node, struct agent_event, node);
+               ret = event_agent_disable_one(usess, agt, aevent);
+
+               if (ret != LTTNG_OK) {
+                       goto end;
+               }
+
+               /* Get next duplicate agent event by name. */
+               agent_event_next_duplicate(event_name, agt, &iter);
+               node = lttng_ht_iter_get_node_str(&iter);
+       } while (node);
+end:
+       rcu_read_unlock();
+       return ret;
+}
 /*
  * Disable all agent event for a given UST session.
  *
@@ -591,7 +634,7 @@ int event_agent_disable_all(struct ltt_ust_session *usess,
                goto error;
        }
 
-       /* Flag every event that they are now enabled. */
+       /* Disable every event. */
        rcu_read_lock();
        cds_lfht_for_each_entry(agt->events->ht, &iter.iter, aevent,
                        node.node) {
@@ -601,14 +644,13 @@ int event_agent_disable_all(struct ltt_ust_session *usess,
 
                ret = event_agent_disable(usess, agt, aevent->name);
                if (ret != LTTNG_OK) {
-                       rcu_read_unlock();
-                       goto error;
+                       goto error_unlock;
                }
        }
-       rcu_read_unlock();
-
        ret = LTTNG_OK;
 
+error_unlock:
+       rcu_read_unlock();
 error:
        return ret;
 }