tools lib traceevent: Get rid of die in add_filter_type()

The realloc() should check return value and not to overwrite previous
pointer in case of error.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung.kim@lge.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/1386833777-3790-3-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/lib/traceevent/parse-filter.c

@@ -161,11 +161,13 @@ add_filter_type(struct event_filter *filter, int id)
 	if (filter_type)
 		return filter_type;
 
-	filter->event_filters =	realloc(filter->event_filters,
-					sizeof(*filter->event_filters) *
-					(filter->filters + 1));
-	if (!filter->event_filters)
-		die("Could not allocate filter");
+	filter_type = realloc(filter->event_filters,
+			      sizeof(*filter->event_filters) *
+			      (filter->filters + 1));
+	if (!filter_type)
+		return NULL;
+
+	filter->event_filters = filter_type;
 
 	for (i = 0; i < filter->filters; i++) {
 		if (filter->event_filters[i].event_id > id)
@@ -1180,6 +1182,12 @@ static int filter_event(struct event_filter *filter,
 	}
 
 	filter_type = add_filter_type(filter, event->id);
+	if (filter_type == NULL) {
+		show_error(error_str, "failed to add a new filter: %s",
+			   filter_str ? filter_str : "true");
+		return -1;
+	}
+
 	if (filter_type->filter)
 		free_arg(filter_type->filter);
 	filter_type->filter = arg;
@@ -1417,6 +1425,9 @@ static int copy_filter_type(struct event_filter *filter,
 			arg->boolean.value = 0;
 
 		filter_type = add_filter_type(filter, event->id);
+		if (filter_type == NULL)
+			return -1;
+
 		filter_type->filter = arg;
 
 		free(str);