On Wed, Oct 07, 2020 at 05:13:11PM +0900, Namhyung Kim wrote:
> It was reported that perf stat crashed when using with armv8_pmu (cpu)
> events with the task mode. As perf stat uses an empty cpu map for
> task mode but armv8_pmu has its own cpu mask, it confused which map
> should use when accessing file descriptors and caused segfaults:
>
> (gdb) bt
> #0 0x0000000000603fc8 in perf_evsel__close_fd_cpu (evsel=<optimized out>,
> cpu=<optimized out>) at evsel.c:122
> #1 perf_evsel__close_cpu (evsel=evsel@entry=0x716e950, cpu=7) at
> evsel.c:156
> #2 0x00000000004d4718 in evlist__close (evlist=0x70a7cb0) at
> util/evlist.c:1242
> #3 0x0000000000453404 in __run_perf_stat (argc=3, argc@entry=1, argv=0x30,
> argv@entry=0xfffffaea2f90, run_idx=119, run_idx@entry=1701998435)
> at builtin-stat.c:929
> #4 0x0000000000455058 in run_perf_stat (run_idx=1701998435,
> argv=0xfffffaea2f90,
> argc=1) at builtin-stat.c:947
> #5 cmd_stat (argc=1, argv=0xfffffaea2f90) at builtin-stat.c:2357
> #6 0x00000000004bb888 in run_builtin (p=p@entry=0x9764b8 <commands+288>,
> argc=argc@entry=4, argv=argv@entry=0xfffffaea2f90) at perf.c:312
> #7 0x00000000004bbb54 in handle_internal_command (argc=argc@entry=4,
> argv=argv@entry=0xfffffaea2f90) at perf.c:364
> #8 0x0000000000435378 in run_argv (argcp=<synthetic pointer>,
> argv=<synthetic pointer>) at perf.c:408
> #9 main (argc=4, argv=0xfffffaea2f90) at perf.c:538
>
> To fix this, I simply used the given cpu map unless the evsel actually
> is not a system-wide event (like uncore events).
>
> Reported-by: Wei Li <liwei...@huawei.com>
> Tested-by: Barry Song <song.bao....@hisilicon.com>
> Fixes: 7736627b865d ("perf stat: Use affinity for closing file descriptors")
> Signed-off-by: Namhyung Kim <namhy...@kernel.org>
Acked-by: Jiri Olsa <jo...@redhat.com>
thanks,
jirka
> ---
> 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 2208444ecb44..cfcdbd7be066 100644
> --- a/tools/lib/perf/evlist.c
> +++ b/tools/lib/perf/evlist.c
> @@ -45,6 +45,9 @@ static void __perf_evlist__propagate_maps(struct
> perf_evlist *evlist,
> if (!evsel->own_cpus || evlist->has_user_cpus) {
> perf_cpu_map__put(evsel->cpus);
> evsel->cpus = perf_cpu_map__get(evlist->cpus);
> + } else if (!evsel->system_wide && perf_cpu_map__empty(evlist->cpus)) {
> + perf_cpu_map__put(evsel->cpus);
> + evsel->cpus = perf_cpu_map__get(evlist->cpus);
> } else if (evsel->cpus != evsel->own_cpus) {
> perf_cpu_map__put(evsel->cpus);
> evsel->cpus = perf_cpu_map__get(evsel->own_cpus);
> --
> 2.28.0.806.g8561365e88-goog
>
