* [PATCH 07/35] perf intel-pt: Fix divide by zero when TSC is not available
[not found] <20190307174433.28819-1-acme@kernel.org>
@ 2019-03-07 17:44 ` Arnaldo Carvalho de Melo
0 siblings, 0 replies; only message in thread
From: Arnaldo Carvalho de Melo @ 2019-03-07 17:44 UTC (permalink / raw)
To: Ingo Molnar
Cc: Jiri Olsa, Namhyung Kim, Clark Williams, linux-kernel,
linux-perf-users, Adrian Hunter, Jiri Olsa, stable,
Arnaldo Carvalho de Melo
From: Adrian Hunter <adrian.hunter@intel.com>
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>
---
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;
--
2.20.1
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