From: David Goulet <dgoulet@efficios.com>
Date: Wed, 15 Feb 2012 00:00:56 +0000 (-0500)
Subject: Fix double start/stop trace
X-Git-Url: http://git.efficios.com/?p=lttng-tools.git;a=commitdiff_plain;h=9bc07046c0e2a572eb3821e276949537614f74e0

Fix double start/stop trace

The started flag, use to detect start vs restart, was set to 0 when
stopping tracing which is really not suppose to. An assert has been
addedd to detect a started = 0 at this stage which is a bad execution
flow error.

Signed-off-by: David Goulet <dgoulet@efficios.com>
---

diff --git a/src/bin/lttng-sessiond/ust-app.c b/src/bin/lttng-sessiond/ust-app.c
index bb012b5d8..335c20ff1 100644
--- a/src/bin/lttng-sessiond/ust-app.c
+++ b/src/bin/lttng-sessiond/ust-app.c
@@ -2037,10 +2037,12 @@ int ust_app_stop_trace(struct ltt_ust_session *usess, struct ust_app *app)
 		goto error_rcu_unlock;
 	}
 
-	/* Not started, continuing. */
-	if (ua_sess->started == 0) {
-		goto end;
-	}
+	/*
+	 * If started = 0, it means that stop trace has been called for a session
+	 * that was never started. This is a code flow error and should never
+	 * happen.
+	 */
+	assert(ua_sess->started == 1);
 
 	/* This inhibits UST tracing */
 	ret = ustctl_stop_session(app->key.sock, ua_sess->handle);
@@ -2071,8 +2073,6 @@ int ust_app_stop_trace(struct ltt_ust_session *usess, struct ust_app *app)
 				ret);
 	}
 
-	ua_sess->started = 0;
-
 end:
 	rcu_read_unlock();
 	return 0;