tracing: Have traceon and traceoff trigger honor the instance

commit 302e9edd upstream.

If a trigger is set on an event to disable or enable tracing within an
instance, then tracing should be disabled or enabled in the instance and
not at the top level, which is confusing to users.

Link: https://lkml.kernel.org/r/20220223223837.14f94ec3@rorschach.local.home

Cc: stable@vger.kernel.org
Fixes: ae63b31e ("tracing: Separate out trace events from global variables")
Tested-by: NDaniel Bristot de Oliveira <bristot@kernel.org>
Reviewed-by: NTom Zanussi <zanussi@kernel.org>
Signed-off-by: NSteven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

kernel/trace/trace_events_trigger.c

@@ -940,6 +940,16 @@ static void
 traceon_trigger(struct event_trigger_data *data, void *rec,
 		struct ring_buffer_event *event)
 {
+	struct trace_event_file *file = data->private_data;
+
+	if (file) {
+		if (tracer_tracing_is_on(file->tr))
+			return;
+
+		tracer_tracing_on(file->tr);
+		return;
+	}
+
 	if (tracing_is_on())
 		return;
 
@@ -950,8 +960,15 @@ static void
 traceon_count_trigger(struct event_trigger_data *data, void *rec,
 		      struct ring_buffer_event *event)
 {
-	if (tracing_is_on())
-		return;
+	struct trace_event_file *file = data->private_data;
+
+	if (file) {
+		if (tracer_tracing_is_on(file->tr))
+			return;
+	} else {
+		if (tracing_is_on())
+			return;
+	}
 
 	if (!data->count)
 		return;
@@ -959,13 +976,26 @@ traceon_count_trigger(struct event_trigger_data *data, void *rec,
 	if (data->count != -1)
 		(data->count)--;
 
-	tracing_on();
+	if (file)
+		tracer_tracing_on(file->tr);
+	else
+		tracing_on();
 }
 
 static void
 traceoff_trigger(struct event_trigger_data *data, void *rec,
 		 struct ring_buffer_event *event)
 {
+	struct trace_event_file *file = data->private_data;
+
+	if (file) {
+		if (!tracer_tracing_is_on(file->tr))
+			return;
+
+		tracer_tracing_off(file->tr);
+		return;
+	}
+
 	if (!tracing_is_on())
 		return;
 
@@ -976,8 +1006,15 @@ static void
 traceoff_count_trigger(struct event_trigger_data *data, void *rec,
 		       struct ring_buffer_event *event)
 {
-	if (!tracing_is_on())
-		return;
+	struct trace_event_file *file = data->private_data;
+
+	if (file) {
+		if (!tracer_tracing_is_on(file->tr))
+			return;
+	} else {
+		if (!tracing_is_on())
+			return;
+	}
 
 	if (!data->count)
 		return;
@@ -985,7 +1022,10 @@ traceoff_count_trigger(struct event_trigger_data *data, void *rec,
 	if (data->count != -1)
 		(data->count)--;
 
-	tracing_off();
+	if (file)
+		tracer_tracing_off(file->tr);
+	else
+		tracing_off();
 }
 
 static int