From: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Date: Mon, 9 Dec 2019 19:31:33 +0000 (-0500)
Subject: Fix: sessiond: RCU read lock imbalance on get trace chunk id error
X-Git-Tag: v2.11.1~27
X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=95b2346e7dc4f74f2bc62b65dc1eede129b17275;p=lttng-tools.git

Fix: sessiond: RCU read lock imbalance on get trace chunk id error

The error path when cmd_setup_relayd() fails to get the ID of a trace
chunk causes the RCU read lock to be released even though it was never
acquired.

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I86aeb99e6cd6ba11634283ab7456a3760a0a6b0d
---

diff --git a/src/bin/lttng-sessiond/cmd.c b/src/bin/lttng-sessiond/cmd.c
index 7c9477df9..e067cb835 100644
--- a/src/bin/lttng-sessiond/cmd.c
+++ b/src/bin/lttng-sessiond/cmd.c
@@ -1185,6 +1185,7 @@ int cmd_setup_relayd(struct ltt_session *session)
 
 	DBG("Setting relayd for session %s", session->name);
 
+	rcu_read_lock();
 	if (session->current_trace_chunk) {
 		enum lttng_trace_chunk_status status = lttng_trace_chunk_get_id(
 				session->current_trace_chunk, &current_chunk_id.value);
@@ -1198,8 +1199,6 @@ int cmd_setup_relayd(struct ltt_session *session)
 		}
 	}
 
-	rcu_read_lock();
-
 	if (usess && usess->consumer && usess->consumer->type == CONSUMER_DST_NET
 			&& usess->consumer->enabled) {
 		/* For each consumer socket, send relayd sockets */