1 files changed, 45 insertions, 18 deletions

diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c
index b33c3861fb..4bec043c86 100644
--- a/kernel/trace/trace_events_trigger.c
+++ b/kernel/trace/trace_events_trigger.c
@@ -597,20 +597,12 @@ out:
 	return ret;
 }
 
-/**
- * unregister_trigger - Generic event_command @unreg implementation
- * @glob: The raw string used to register the trigger
- * @test: Trigger-specific data used to find the trigger to remove
- * @file: The trace_event_file associated with the event
- *
- * Common implementation for event trigger unregistration.
- *
- * Usually used directly as the @unreg method in event command
- * implementations.
+/*
+ * True if the trigger was found and unregistered, else false.
  */
-static void unregister_trigger(char *glob,
-			       struct event_trigger_data *test,
-			       struct trace_event_file *file)
+static bool try_unregister_trigger(char *glob,
+				   struct event_trigger_data *test,
+				   struct trace_event_file *file)
 {
 	struct event_trigger_data *data = NULL, *iter;
 
@@ -626,8 +618,32 @@ static void unregister_trigger(char *glob,
 		}
 	}
 
-	if (data && data->ops->free)
-		data->ops->free(data);
+	if (data) {
+		if (data->ops->free)
+			data->ops->free(data);
+
+		return true;
+	}
+
+	return false;
+}
+
+/**
+ * unregister_trigger - Generic event_command @unreg implementation
+ * @glob: The raw string used to register the trigger
+ * @test: Trigger-specific data used to find the trigger to remove
+ * @file: The trace_event_file associated with the event
+ *
+ * Common implementation for event trigger unregistration.
+ *
+ * Usually used directly as the @unreg method in event command
+ * implementations.
+ */
+static void unregister_trigger(char *glob,
+			       struct event_trigger_data *test,
+			       struct trace_event_file *file)
+{
+	try_unregister_trigger(glob, test, file);
 }
 
 /*
@@ -1470,12 +1486,23 @@ register_snapshot_trigger(char *glob,
 			  struct event_trigger_data *data,
 			  struct trace_event_file *file)
 {
-	int ret = tracing_alloc_snapshot_instance(file->tr);
+	int ret = tracing_arm_snapshot(file->tr);
 
 	if (ret < 0)
 		return ret;
 
-	return register_trigger(glob, data, file);
+	ret = register_trigger(glob, data, file);
+	if (ret < 0)
+		tracing_disarm_snapshot(file->tr);
+	return ret;
+}
+
+static void unregister_snapshot_trigger(char *glob,
+					struct event_trigger_data *data,
+					struct trace_event_file *file)
+{
+	if (try_unregister_trigger(glob, data, file))
+		tracing_disarm_snapshot(file->tr);
 }
 
 static int
@@ -1510,7 +1537,7 @@ static struct event_command trigger_snapshot_cmd = {
 	.trigger_type		= ETT_SNAPSHOT,
 	.parse			= event_trigger_parse,
 	.reg			= register_snapshot_trigger,
-	.unreg			= unregister_trigger,
+	.unreg			= unregister_snapshot_trigger,
 	.get_trigger_ops	= snapshot_get_trigger_ops,
 	.set_filter		= set_trigger_filter,
 };