Re: [PATCH] perf tools: Fix parser for empty pmu terms case

From: Arnaldo Carvalho de Melo
Date: Mon May 07 2018 - 11:04:35 EST


Em Mon, May 07, 2018 at 10:12:03AM +0200, Jiri Olsa escreveu:
> On Mon, May 07, 2018 at 10:21:42AM +0300, Adrian Hunter wrote:
> > On 06/05/18 17:28, Jiri Olsa wrote:
> > > On Sat, May 05, 2018 at 08:43:11PM -0700, Andi Kleen wrote:
> > >> Jiri Olsa <jolsa@xxxxxxxxxx> writes:
> > >>
> > >> Please fix this quickly, PT is currently totally non functional in Linus
> > >> mainline.
> > >
> > > attached.. Kan, could you please test it wrt your latest changes?
> > >
> > > thanks,
> > > jirka
> > >
> > >
> > > ---
> > > Adrian reported broken event parsing for Intel PT:
> > >
> > > $ perf record -e intel_pt//u uname
> > > event syntax error: 'intel_pt//u'
> > > \___ parser error
> > > Run 'perf list' for a list of valid events
> > >
> > > It's caused by recent change in parsing grammar
> > > (see Fixes: for commit).
> > >
> > > Adding special rule with empty terms config to handle
> > > the reported case and moving the common rule code into
> > > new parse_events_pmu function.
> >
> > Hi
> >
> > Can you explain why that is needed instead of just changing the grammar e.g.
>
> well, for one, mine is working ;-)
>
> [jolsa@krava perf]$ sudo ./perf record -e intel_pt//u uname
> event syntax error: 'intel_pt//u'
> \___ parser error
> Run 'perf list' for a list of valid events
>
> Usage: perf record [<options>] [<command>]
> or: perf record [<options>] -- <command> [<options>]
>
> -e, --event <event> event selector. use 'perf list' to list available events
>
>
> but yep, it's better solution.. with extra changes like below

So, can I get a final patch, with an Ack from Adrian, please?

- Arnaldo

> jirka
>
>
> ---
> diff --git a/tools/perf/util/parse-events.y b/tools/perf/util/parse-events.y
> index 47f6399a309a..155d2570274f 100644
> --- a/tools/perf/util/parse-events.y
> +++ b/tools/perf/util/parse-events.y
> @@ -73,6 +73,7 @@ static void inc_group_count(struct list_head *list,
> %type <num> value_sym
> %type <head> event_config
> %type <head> opt_event_config
> +%type <head> opt_pmu_config
> %type <term> event_term
> %type <head> event_pmu
> %type <head> event_legacy_symbol
> @@ -224,15 +225,15 @@ event_def: event_pmu |
> event_bpf_file
>
> event_pmu:
> -PE_NAME '/' event_config '/'
> +PE_NAME opt_pmu_config
> {
> struct list_head *list, *orig_terms, *terms;
>
> - if (parse_events_copy_term_list($3, &orig_terms))
> + if (parse_events_copy_term_list($2, &orig_terms))
> YYABORT;
>
> ALLOC_LIST(list);
> - if (parse_events_add_pmu(_parse_state, list, $1, $3, false, false)) {
> + if (parse_events_add_pmu(_parse_state, list, $1, $2, false, false)) {
> struct perf_pmu *pmu = NULL;
> int ok = 0;
> char *pattern;
> @@ -262,7 +263,7 @@ PE_NAME '/' event_config '/'
> if (!ok)
> YYABORT;
> }
> - parse_events_terms__delete($3);
> + parse_events_terms__delete($2);
> parse_events_terms__delete(orig_terms);
> $$ = list;
> }
> @@ -496,6 +497,17 @@ opt_event_config:
> $$ = NULL;
> }
>
> +opt_pmu_config:
> +'/' event_config '/'
> +{
> + $$ = $2;
> +}
> +|
> +'/' '/'
> +{
> + $$ = NULL;
> +}
> +
> start_terms: event_config
> {
> struct parse_events_state *parse_state = _parse_state;