Re: [BUG] libtraceevent: perf script -g python segfaults

From: Steven Rostedt
Date: Thu Oct 17 2019 - 14:41:19 EST


On Thu, 17 Oct 2019 14:38:41 -0400
Steven Rostedt <rostedt@xxxxxxxxxxx> wrote:

> struct tep_event *trace_find_next_event(struct tep_handle *pevent,
> struct tep_event *event)
> {
> + static struct tep_event **all_events;
> static int idx;
> int events_count;
> - struct tep_event *all_events;

If we are going to use static variables, let's make them all static and
optimize it a little more...

-- Steve

diff --git a/tools/perf/util/trace-event-parse.c b/tools/perf/util/trace-event-parse.c
index ad74be1f0e42..3f23462517a3 100644
--- a/tools/perf/util/trace-event-parse.c
+++ b/tools/perf/util/trace-event-parse.c
@@ -193,30 +193,35 @@ int parse_event_file(struct tep_handle *pevent,
struct tep_event *trace_find_next_event(struct tep_handle *pevent,
struct tep_event *event)
{
+ static struct tep_event **all_events;
+ static int events_count;
static int idx;
- int events_count;
- struct tep_event *all_events;

- all_events = tep_get_first_event(pevent);
- events_count = tep_get_events_count(pevent);
- if (!pevent || !all_events || events_count < 1)
+ if (!pevent || !all_events)
return NULL;

if (!event) {
idx = 0;
- return all_events;
+ events_count = tep_get_events_count(pevent);
+ if (events_count < 1)
+ return NULL;
+
+ all_events = tep_list_events(pevent, TEP_EVENT_SORT_ID);
+ if (all_events)
+ return all_events[0];
+ return NULL;
}

- if (idx < events_count && event == (all_events + idx)) {
+ if (idx < events_count && event == all_events[idx]) {
idx++;
if (idx == events_count)
return NULL;
- return (all_events + idx);
+ return all_events[idx];
}

for (idx = 1; idx < events_count; idx++) {
- if (event == (all_events + (idx - 1)))
- return (all_events + idx);
+ if (event == all_events[idx - 1])
+ return all_events[idx];
}
return NULL;
}