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

From: Arnaldo Carvalho de Melo
Date: Thu Oct 17 2019 - 15:49:15 EST


Em Thu, Oct 17, 2019 at 03:37:33PM -0400, Steven Rostedt escreveu:
> On Thu, 17 Oct 2019 16:28:32 -0300
> Arnaldo Carvalho de Melo <arnaldo.melo@xxxxxxxxx> wrote:
>
> > Em Thu, Oct 17, 2019 at 02:41:14PM -0400, Steven Rostedt escreveu:
> > > 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...
> >
> > I'll test it, but can't you have this somewhere else, i.e. at
> > tep_handle perhaps?
> >
> >
>
> Or we can nuke the function entirely, it's a rather silly helper
> anyway. Just do this:

I like it, that is a good nuke use, nice button to press! :-)

Testing it now...

- Arnaldo

> -- Steve
>
>
> diff --git a/tools/perf/util/scripting-engines/trace-event-perl.c b/tools/perf/util/scripting-engines/trace-event-perl.c
> index b93f36b887b5..f1d5f564aa46 100644
> --- a/tools/perf/util/scripting-engines/trace-event-perl.c
> +++ b/tools/perf/util/scripting-engines/trace-event-perl.c
> @@ -537,10 +537,11 @@ static int perl_stop_script(void)
>
> static int perl_generate_script(struct tep_handle *pevent, const char *outfile)
> {
> + int i, not_first, count, nr_events;
> + struct tep_event **all_events;
> struct tep_event *event = NULL;
> struct tep_format_field *f;
> char fname[PATH_MAX];
> - int not_first, count;
> FILE *ofp;
>
> sprintf(fname, "%s.pl", outfile);
> @@ -601,8 +602,11 @@ sub print_backtrace\n\
> }\n\n\
> ");
>
> + nr_events = tep_get_events_count(pevent);
> + all_events = tep_list_events(pevent, TEP_EVENT_SORT_ID);
>
> - while ((event = trace_find_next_event(pevent, event))) {
> + for (i = 0; all_events && i < nr_events; i++) {
> + event = all_events[i];
> fprintf(ofp, "sub %s::%s\n{\n", event->system, event->name);
> fprintf(ofp, "\tmy (");
>
> diff --git a/tools/perf/util/scripting-engines/trace-event-python.c b/tools/perf/util/scripting-engines/trace-event-python.c
> index 87ef16a1b17e..2a148a10d0de 100644
> --- a/tools/perf/util/scripting-engines/trace-event-python.c
> +++ b/tools/perf/util/scripting-engines/trace-event-python.c
> @@ -1590,10 +1590,11 @@ static int python_stop_script(void)
>
> static int python_generate_script(struct tep_handle *pevent, const char *outfile)
> {
> + int i, not_first, count, nr_events;
> + struct tep_event **all_events;
> struct tep_event *event = NULL;
> struct tep_format_field *f;
> char fname[PATH_MAX];
> - int not_first, count;
> FILE *ofp;
>
> sprintf(fname, "%s.py", outfile);
> @@ -1638,7 +1639,11 @@ static int python_generate_script(struct tep_handle *pevent, const char *outfile
> fprintf(ofp, "def trace_end():\n");
> fprintf(ofp, "\tprint(\"in trace_end\")\n\n");
>
> - while ((event = trace_find_next_event(pevent, event))) {
> + nr_events = tep_get_events_count(pevent);
> + all_events = tep_list_events(pevent, TEP_EVENT_SORT_ID);
> +
> + for (i = 0; all_events && i < nr_events; i++) {
> + event = all_events[i];
> fprintf(ofp, "def %s__%s(", event->system, event->name);
> fprintf(ofp, "event_name, ");
> fprintf(ofp, "context, ");
>

--

- Arnaldo