Subject: Re: [PATCH 4/5] perf stat: Avoid segv if core.user_cpus isn't set.

From: Arnaldo Carvalho de Melo <[email-masked]>
Date: Mon, 28 Mar 2022 17:32:31 -0300

Em Sun, Mar 27, 2022 at 11:24:13PM -0700, Ian Rogers escreveu:
> Passing null to perf_cpu_map__max doesn't make sense as there is no
> valid max. Avoid this problem by null checking in
> perf_stat_init_aggr_mode.

Applying this one after changing user_cpus back to cpus as this is a fix
independent of this patchset.

In the future, please try to have such patches at the beginning of the
series, so that  they can get cherry-picked more easily.

- Arnaldo
 
> Signed-off-by: Ian Rogers <[email-masked]>
> ---
>  tools/perf/builtin-stat.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
> index 5bee529f7656..ecd5cf4fd872 100644
> --- a/tools/perf/builtin-stat.c
> +++ b/tools/perf/builtin-stat.c
> @@ -1472,7 +1472,10 @@ static int perf_stat_init_aggr_mode(void)
>  	 * taking the highest cpu number to be the size of
>  	 * the aggregation translate cpumap.
>  	 */
> -	nr = perf_cpu_map__max(evsel_list->core.user_cpus).cpu;
> +	if (evsel_list->core.user_cpus)
> +		nr = perf_cpu_map__max(evsel_list->core.user_cpus).cpu;
> +	else
> +		nr = 0;
>  	stat_config.cpus_aggr_map = cpu_aggr_map__empty_new(nr + 1);
>  	return stat_config.cpus_aggr_map ? 0 : -ENOMEM;
>  }
> -- 
> 2.35.1.1021.g381101b075-goog

-- 

- Arnaldo