| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.9 111/118] perf intel-pt: Fix divide by zero when TSC is not available | Date | Fri, 22 Mar 2019 12:16:23 +0100 |
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4.9-stable review patch. If anyone has any objections, please let me know.
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From: Adrian Hunter <adrian.hunter@intel.com>
commit 076333870c2f5bdd9b6d31e7ca1909cf0c84cbfa upstream.
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.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: stable@vger.kernel.org # v4.9+ Link: https://lkml.kernel.org/n/tip-1i4j0wqoc8vlbkcizqqxpsf4@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- tools/perf/util/intel-pt.c | 2 ++ 1 file changed, 2 insertions(+)
--- a/tools/perf/util/intel-pt.c +++ b/tools/perf/util/intel-pt.c @@ -2259,6 +2259,8 @@ int intel_pt_process_auxtrace_info(union } 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;
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