Re: [PATCH v4 4/9] perf tools: splice events onto evlist even on error

From: Arnaldo Carvalho de Melo <arnaldo.melo@gmail.com>
To: Jiri Olsa <jolsa@redhat.com>
Cc: Ian Rogers <irogers@google.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Ingo Molnar <mingo@redhat.com>,
	Mark Rutland <mark.rutland@arm.com>,
	Alexander Shishkin <alexander.shishkin@linux.intel.com>,
	Namhyung Kim <namhyung@kernel.org>,
	Alexei Starovoitov <ast@kernel.org>,
	Daniel Borkmann <daniel@iogearbox.net>,
	Martin KaFai Lau <kafai@fb.com>, Song Liu <songliubraving@fb.com>,
	Yonghong Song <yhs@fb.com>, Andi Kleen <ak@linux.intel.com>,
	Jin Yao <yao.jin@linux.intel.com>,
	Adrian Hunter <adrian.hunter@intel.com>,
	Kan Liang <kan.liang@linux.intel.com>,
	John Garry <john.garry@huawei.com>,
	linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
	bpf@vger.kernel.org, clang-built-linux@googlegroups.com,
	Stephane Eranian <eranian@google.com>
Subject: Re: [PATCH v4 4/9] perf tools: splice events onto evlist even on error
Date: Wed, 30 Oct 2019 08:56:30 -0300	[thread overview]
Message-ID: <20191030115630.GC27327@kernel.org> (raw)
In-Reply-To: <20191028210712.GB6158@krava>

Em Mon, Oct 28, 2019 at 10:07:12PM +0100, Jiri Olsa escreveu:
> On Fri, Oct 25, 2019 at 11:08:22AM -0700, Ian Rogers wrote:
> > If event parsing fails the event list is leaked, instead splice the list
> > onto the out result and let the caller cleanup.
> > 
> > An example input for parse_events found by libFuzzer that reproduces
> > this memory leak is 'm{'.
> > 
> > Signed-off-by: Ian Rogers <irogers@google.com>
> 
> Acked-by: Jiri Olsa <jolsa@kernel.org>

Thanks, applied.

> thanks,
> jirka
> 
> > ---
> >  tools/perf/util/parse-events.c | 17 +++++++++++------
> >  1 file changed, 11 insertions(+), 6 deletions(-)
> > 
> > diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
> > index c516d0cce946..4c4c6f3e866a 100644
> > --- a/tools/perf/util/parse-events.c
> > +++ b/tools/perf/util/parse-events.c
> > @@ -1952,15 +1952,20 @@ int parse_events(struct evlist *evlist, const char *str,
> >  
> >  	ret = parse_events__scanner(str, &parse_state, PE_START_EVENTS);
> >  	perf_pmu__parse_cleanup();
> > +
> > +	if (!ret && list_empty(&parse_state.list)) {
> > +		WARN_ONCE(true, "WARNING: event parser found nothing\n");
> > +		return -1;
> > +	}
> > +
> > +	/*
> > +	 * Add list to the evlist even with errors to allow callers to clean up.
> > +	 */
> > +	perf_evlist__splice_list_tail(evlist, &parse_state.list);
> > +
> >  	if (!ret) {
> >  		struct evsel *last;
> >  
> > -		if (list_empty(&parse_state.list)) {
> > -			WARN_ONCE(true, "WARNING: event parser found nothing\n");
> > -			return -1;
> > -		}
> > -
> > -		perf_evlist__splice_list_tail(evlist, &parse_state.list);
> >  		evlist->nr_groups += parse_state.nr_groups;
> >  		last = evlist__last(evlist);
> >  		last->cmdline_group_boundary = true;
> > -- 
> > 2.24.0.rc0.303.g954a862665-goog
> > 

-- 

- Arnaldo