Re: [PATCH 04/15] perf stat: Use scnprintf() in prepare_interval()

From: Ian Rogers <irogers@google.com>
To: Namhyung Kim <namhyung@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>,
	Jiri Olsa <jolsa@kernel.org>, Ingo Molnar <mingo@kernel.org>,
	Peter Zijlstra <peterz@infradead.org>,
	LKML <linux-kernel@vger.kernel.org>,
	Adrian Hunter <adrian.hunter@intel.com>,
	linux-perf-users@vger.kernel.org,
	Kan Liang <kan.liang@linux.intel.com>,
	Zhengjun Xing <zhengjun.xing@linux.intel.com>,
	James Clark <james.clark@arm.com>,
	Athira Jajeev <atrajeev@linux.vnet.ibm.com>
Subject: Re: [PATCH 04/15] perf stat: Use scnprintf() in prepare_interval()
Date: Wed, 23 Nov 2022 15:22:01 -0800	[thread overview]
Message-ID: <CAP-5=fXzc4-U=g96dr7jzUHNKudcUh2JZW89BT8xs01Zfp7ZDw@mail.gmail.com> (raw)
In-Reply-To: <20221123180208.2068936-5-namhyung@kernel.org>

On Wed, Nov 23, 2022 at 10:02 AM Namhyung Kim <namhyung@kernel.org> wrote:
>
> It should not use sprintf() anymore.  Let's pass the buffer size and use the
> safer scnprintf() instead.
>
> Signed-off-by: Namhyung Kim <namhyung@kernel.org>

Acked-by: Ian Rogers <irogers@google.com>

Thanks,
Ian

> ---
>  tools/perf/util/stat-display.c | 20 ++++++++++----------
>  1 file changed, 10 insertions(+), 10 deletions(-)
>
> diff --git a/tools/perf/util/stat-display.c b/tools/perf/util/stat-display.c
> index 15c88b9b5aa3..744b7a40f59a 100644
> --- a/tools/perf/util/stat-display.c
> +++ b/tools/perf/util/stat-display.c
> @@ -1073,23 +1073,23 @@ static void print_metric_headers(struct perf_stat_config *config,
>  }
>
>  static void prepare_interval(struct perf_stat_config *config,
> -                            char *prefix, struct timespec *ts)
> +                            char *prefix, size_t len, struct timespec *ts)
>  {
>         if (config->iostat_run)
>                 return;
>
>         if (config->csv_output)
> -               sprintf(prefix, "%lu.%09lu%s", (unsigned long) ts->tv_sec,
> -                                ts->tv_nsec, config->csv_sep);
> +               scnprintf(prefix, len, "%lu.%09lu%s",
> +                         (unsigned long) ts->tv_sec, ts->tv_nsec, config->csv_sep);
>         else if (!config->json_output)
> -               sprintf(prefix, "%6lu.%09lu ", (unsigned long) ts->tv_sec,
> -                                ts->tv_nsec);
> +               scnprintf(prefix, len, "%6lu.%09lu ",
> +                         (unsigned long) ts->tv_sec, ts->tv_nsec);
>         else if (!config->metric_only)
> -               sprintf(prefix, "{\"interval\" : %lu.%09lu, ", (unsigned long)
> -                                ts->tv_sec, ts->tv_nsec);
> +               scnprintf(prefix, len, "{\"interval\" : %lu.%09lu, ",
> +                         (unsigned long) ts->tv_sec, ts->tv_nsec);
>         else
> -               sprintf(prefix, "{\"interval\" : %lu.%09lu}", (unsigned long)
> -                                ts->tv_sec, ts->tv_nsec);
> +               scnprintf(prefix, len, "{\"interval\" : %lu.%09lu}",
> +                         (unsigned long) ts->tv_sec, ts->tv_nsec);
>  }
>
>  static void print_header_interval_std(struct perf_stat_config *config,
> @@ -1390,7 +1390,7 @@ void evlist__print_counters(struct evlist *evlist, struct perf_stat_config *conf
>
>         if (interval) {
>                 prefix = buf;
> -               prepare_interval(config, prefix, ts);
> +               prepare_interval(config, buf, sizeof(buf), ts);
>         }
>
>         print_header(config, _target, evlist, argc, argv);
> --
> 2.38.1.584.g0f3c55d4c2-goog
>