1 files changed, 50 insertions, 9 deletions

diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c
index 28733bd6b607..651a1449acde 100644
--- a/kernel/trace/trace_probe.c
+++ b/kernel/trace/trace_probe.c
@@ -886,6 +886,35 @@ int traceprobe_define_arg_fields(struct trace_event_call *event_call,
 	return 0;
 }
 
+static void trace_probe_event_free(struct trace_probe_event *tpe)
+{
+	kfree(tpe->class.system);
+	kfree(tpe->call.name);
+	kfree(tpe->call.print_fmt);
+	kfree(tpe);
+}
+
+int trace_probe_append(struct trace_probe *tp, struct trace_probe *to)
+{
+	if (trace_probe_has_sibling(tp))
+		return -EBUSY;
+
+	list_del_init(&tp->list);
+	trace_probe_event_free(tp->event);
+
+	tp->event = to->event;
+	list_add_tail(&tp->list, trace_probe_probe_list(to));
+
+	return 0;
+}
+
+void trace_probe_unlink(struct trace_probe *tp)
+{
+	list_del_init(&tp->list);
+	if (list_empty(trace_probe_probe_list(tp)))
+		trace_probe_event_free(tp->event);
+	tp->event = NULL;
+}
 
 void trace_probe_cleanup(struct trace_probe *tp)
 {
@@ -894,15 +923,8 @@ void trace_probe_cleanup(struct trace_probe *tp)
 	for (i = 0; i < tp->nr_args; i++)
 		traceprobe_free_probe_arg(&tp->args[i]);
 
-	if (tp->event) {
-		struct trace_event_call *call = trace_probe_event_call(tp);
-
-		kfree(tp->event->class.system);
-		kfree(call->name);
-		kfree(call->print_fmt);
-		kfree(tp->event);
-		tp->event = NULL;
-	}
+	if (tp->event)
+		trace_probe_unlink(tp);
 }
 
 int trace_probe_init(struct trace_probe *tp, const char *event,
@@ -1006,3 +1028,22 @@ int trace_probe_remove_file(struct trace_probe *tp,
 
 	return 0;
 }
+
+/*
+ * Return the smallest index of different type argument (start from 1).
+ * If all argument types and name are same, return 0.
+ */
+int trace_probe_compare_arg_type(struct trace_probe *a, struct trace_probe *b)
+{
+	int i;
+
+	for (i = 0; i < a->nr_args; i++) {
+		if ((b->nr_args <= i) ||
+		    ((a->args[i].type != b->args[i].type) ||
+		     (a->args[i].count != b->args[i].count) ||
+		     strcmp(a->args[i].name, b->args[i].name)))
+			return i + 1;
+	}
+
+	return 0;
+}