Fix: duplicated kernel consumer socket locking

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

diff --git a/src/bin/lttng-sessiond/ust-app.c b/src/bin/lttng-sessiond/ust-app.c
index 54479e23c03416b2a6d44b6bf7c780b949141d01..60ff1be03b194eee686aa391e73615039988b3ab 100644 (file)
--- a/src/bin/lttng-sessiond/ust-app.c
+++ b/src/bin/lttng-sessiond/ust-app.c
@@ -2845,6 +2845,8 @@ error:
 /*
  * Create and send to the application the created buffers with per UID buffers.
  *
+ * This MUST be called with a RCU read side lock acquired.
+ *
  * Return 0 on success else a negative value.
  */
 static int create_channel_per_uid(struct ust_app *app,
@@ -2923,7 +2925,6 @@ static int create_channel_per_uid(struct ust_app *app,
                uint64_t chan_reg_key;
                struct ust_registry_channel *chan_reg;
 
-               rcu_read_lock();
                chan_reg_key = ua_chan->tracing_channel_id;
 
                pthread_mutex_lock(&reg_uid->registry->reg.ust->lock);
@@ -2944,7 +2945,6 @@ static int create_channel_per_uid(struct ust_app *app,
                                ua_chan->key,
                                LTTNG_DOMAIN_UST,
                                ua_chan->attr.subbuf_size * ua_chan->attr.num_subbuf);
-               rcu_read_unlock();
                if (cmd_ret != LTTNG_OK) {
                        ret = - (int) cmd_ret;
                        ERR("Failed to add channel to notification thread");
@@ -3577,8 +3577,8 @@ void ust_app_unregister(int sock)
        /*
         * Remove application from notify hash table. The thread handling the
         * notify socket could have deleted the node so ignore on error because
-        * either way it's valid. The close of that socket is handled by the other
-        * thread.
+        * either way it's valid. The close of that socket is handled by the
+        * apps_notify_thread.
         */
        iter.iter.node = &lta->notify_sock_n.node;
        (void) lttng_ht_del(ust_app_ht_by_notify_sock, &iter);