From: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Date: Wed, 14 Nov 2018 21:00:15 +0000 (-0500)
Subject: Fix: session_list lock must be held to launch a rotation
X-Git-Tag: v2.12.0-rc1~768
X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=ed1e52a3cc41925b701cd1343ace4c450ff836d9;p=lttng-tools.git

Fix: session_list lock must be held to launch a rotation

The timer.h functions are documented as needing the session_list
lock to be held. Since timers are setup during the launch of a
rotation, the session_list lock must be taken while a job is
executed by the rotation thread.

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

diff --git a/src/bin/lttng-sessiond/rotation-thread.c b/src/bin/lttng-sessiond/rotation-thread.c
index 25dbf76a9..3256a1e9b 100644
--- a/src/bin/lttng-sessiond/rotation-thread.c
+++ b/src/bin/lttng-sessiond/rotation-thread.c
@@ -642,7 +642,7 @@ end:
 	return ret;
 }
 
-/* Call with the session lock held. */
+/* Call with the session and session_list locks held. */
 static
 int launch_session_rotation(struct ltt_session *session)
 {
@@ -736,10 +736,9 @@ int handle_job_queue(struct rotation_thread_handle *handle,
 		}
 
 		session_lock(session);
-		session_unlock_list();
-
 	        ret = run_job(job, session, handle->notification_thread_handle);
 		session_unlock(session);
+		session_unlock_list();
 		free(job);
 		if (ret) {
 			goto end;