X-Git-Url: https://git.lttng.org/?a=blobdiff_plain;f=src%2Fbin%2Flttng-sessiond%2Fust-app.c;h=60ff1be03b194eee686aa391e73615039988b3ab;hb=c48239ca84a44d342de990288dbb5cc3e90b3a1d;hp=e79455b01fb055588c7473a913f583ae9e567ad3;hpb=7682f30487cfe11af077c668193bb26f587a6081;p=lttng-tools.git

diff --git a/src/bin/lttng-sessiond/ust-app.c b/src/bin/lttng-sessiond/ust-app.c
index e79455b01..60ff1be03 100644
--- 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,
@@ -2917,22 +2919,12 @@ static int create_channel_per_uid(struct ust_app *app,
 		created = true;
 	}
 
-	/* Send buffers to the application. */
-	ret = send_channel_uid_to_ust(reg_chan, app, ua_sess, ua_chan);
-	if (ret < 0) {
-		if (ret != -ENOTCONN) {
-			ERR("Error sending channel to application");
-		}
-		goto error;
-	}
-
 	if (created) {
 		enum lttng_error_code cmd_ret;
 		struct ltt_session *session;
 		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);
@@ -2953,7 +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");
@@ -2961,6 +2952,15 @@ static int create_channel_per_uid(struct ust_app *app,
 		}
 	}
 
+	/* Send buffers to the application. */
+	ret = send_channel_uid_to_ust(reg_chan, app, ua_sess, ua_chan);
+	if (ret < 0) {
+		if (ret != -ENOTCONN) {
+			ERR("Error sending channel to application");
+		}
+		goto error;
+	}
+
 error:
 	return ret;
 }
@@ -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);