Re: [PATCH] perf intel-pt: Fix divide by zero

From: Arnaldo Carvalho de Melo
Date: Fri Mar 01 2019 - 12:49:47 EST


Em Fri, Mar 01, 2019 at 12:35:36PM +0200, Adrian Hunter escreveu:
> When tsc is not available, "timeless" decoding is used but a divide by
> zero occurs if perf_time_to_tsc() is called. Ensure the divisor is not
> zero.

Thanks, applied.

- Arnaldo

> Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx # v4.9+
> ---
> tools/perf/util/intel-pt.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/tools/perf/util/intel-pt.c b/tools/perf/util/intel-pt.c
> index 3b497bab4324..6d288237887b 100644
> --- a/tools/perf/util/intel-pt.c
> +++ b/tools/perf/util/intel-pt.c
> @@ -2531,6 +2531,8 @@ int intel_pt_process_auxtrace_info(union perf_event *event,
> }
>
> pt->timeless_decoding = intel_pt_timeless_decoding(pt);
> + if (pt->timeless_decoding && !pt->tc.time_mult)
> + pt->tc.time_mult = 1;
> pt->have_tsc = intel_pt_have_tsc(pt);
> pt->sampling_mode = false;
> pt->est_tsc = !pt->timeless_decoding;
> --
> 2.17.1

--

- Arnaldo