Re: [PATCH] perf tools: Setup initial evlist::all_cpus value

[Andi Kleen]

On Fri, Jan 10, 2020 at 04:15:37PM +0100, Jiri Olsa wrote:
> Jann Horn reported crash in perf ftrace because evlist::all_cpus
> isn't initialized if there's evlist without events, which is the
> case for perf ftrace.
> 
> Adding initial initialization of evlist::all_cpus from given cpus,
> regardless of events in the evlist.

Acked-by: Andi Kleen <ak@xxxxxxxxxxxxxxx>

> 
> Reported-by: Jann Horn <jannh@xxxxxxxxxx>
> Link: https://lkml.kernel.org/n/tip-kzioebqr5c3u4t7tafju8pbx@xxxxxxxxxxxxxx
> Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
> ---
>  tools/lib/perf/evlist.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/tools/lib/perf/evlist.c b/tools/lib/perf/evlist.c
> index ae9e65aa2491..5b9f2ca50591 100644
> --- a/tools/lib/perf/evlist.c
> +++ b/tools/lib/perf/evlist.c
> @@ -164,6 +164,9 @@ void perf_evlist__set_maps(struct perf_evlist *evlist,
>  		evlist->threads = perf_thread_map__get(threads);
>  	}
>  
> +	if (!evlist->all_cpus && cpus)
> +		evlist->all_cpus = perf_cpu_map__get(cpus);
> +
>  	perf_evlist__propagate_maps(evlist);
>  }
>  
> -- 
> 2.24.1
>