Re: [PATCH 2/2] perf parse-events: Avoid an uninitialized read.

[Arnaldo Carvalho de Melo]

Em Wed, Aug 26, 2020 at 01:34:18PM +0200, Jiri Olsa escreveu:
> On Tue, Aug 25, 2020 at 09:29:10PM -0700, Ian Rogers wrote:
> > With a fake_pmu the pmu_info isn't populated by perf_pmu__check_alias.
> > In this case, don't try to copy the uninitialized values to the evsel.
> > 
> > Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
> 
> Acked-by: Jiri Olsa <jolsa@xxxxxxxxxx>

Thanks, applied.

- Arnaldo
 
> thanks,
> jirka
> 
> > ---
> >  tools/perf/util/parse-events.c | 30 +++++++++++++++++-------------
> >  1 file changed, 17 insertions(+), 13 deletions(-)
> > 
> > diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
> > index 9f7260e69113..3d7a48b488ed 100644
> > --- a/tools/perf/util/parse-events.c
> > +++ b/tools/perf/util/parse-events.c
> > @@ -1533,19 +1533,23 @@ int parse_events_add_pmu(struct parse_events_state *parse_state,
> >  	evsel = __add_event(list, &parse_state->idx, &attr, true,
> >  			    get_config_name(head_config), pmu,
> >  			    &config_terms, auto_merge_stats, NULL);
> > -	if (evsel) {
> > -		evsel->unit = info.unit;
> > -		evsel->scale = info.scale;
> > -		evsel->per_pkg = info.per_pkg;
> > -		evsel->snapshot = info.snapshot;
> > -		evsel->metric_expr = info.metric_expr;
> > -		evsel->metric_name = info.metric_name;
> > -		evsel->pmu_name = name ? strdup(name) : NULL;
> > -		evsel->use_uncore_alias = use_uncore_alias;
> > -		evsel->percore = config_term_percore(&evsel->config_terms);
> > -	}
> > -
> > -	return evsel ? 0 : -ENOMEM;
> > +	if (!evsel)
> > +		return -ENOMEM;
> > +
> > +	evsel->pmu_name = name ? strdup(name) : NULL;
> > +	evsel->use_uncore_alias = use_uncore_alias;
> > +	evsel->percore = config_term_percore(&evsel->config_terms);
> > +
> > +	if (parse_state->fake_pmu)
> > +		return 0;
> > +
> > +	evsel->unit = info.unit;
> > +	evsel->scale = info.scale;
> > +	evsel->per_pkg = info.per_pkg;
> > +	evsel->snapshot = info.snapshot;
> > +	evsel->metric_expr = info.metric_expr;
> > +	evsel->metric_name = info.metric_name;
> > +	return 0;
> >  }
> >  
> >  int parse_events_multi_pmu_add(struct parse_events_state *parse_state,
> > -- 
> > 2.28.0.297.g1956fa8f8d-goog
> > 
> 

-- 

- Arnaldo