Commit-ID: e8968e654191390a1300f0847250353a1c9da30d Gitweb: http://git.kernel.org/tip/e8968e654191390a1300f0847250353a1c9da30d Author: Jiri Olsa <jolsa@xxxxxxxxxx> AuthorDate: Sun, 10 Jul 2016 13:07:56 +0200 Committer: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx> CommitDate: Tue, 12 Jul 2016 16:16:44 -0300 perf python: Fix pyrf_evlist__read_on_cpu event consuming We can't consume the event before parsing it. Under heavy load we could get caught by kernel writer overwriting the event we're trying to parse. Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx> Cc: David Ahern <dsahern@xxxxxxxxx> Cc: Namhyung Kim <namhyung@xxxxxxxxxx> Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx> Link: http://lkml.kernel.org/r/1468148882-10362-5-git-send-email-jolsa@xxxxxxxxxx Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx> --- tools/perf/util/python.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/tools/perf/util/python.c b/tools/perf/util/python.c index d0c1267..c68ef03 100644 --- a/tools/perf/util/python.c +++ b/tools/perf/util/python.c @@ -865,12 +865,14 @@ static PyObject *pyrf_evlist__read_on_cpu(struct pyrf_evlist *pevlist, PyObject *pyevent = pyrf_event__new(event); struct pyrf_event *pevent = (struct pyrf_event *)pyevent; - perf_evlist__mmap_consume(evlist, cpu); - if (pyevent == NULL) return PyErr_NoMemory(); err = perf_evlist__parse_sample(evlist, event, &pevent->sample); + + /* Consume the even only after we parsed it out. */ + perf_evlist__mmap_consume(evlist, cpu); + if (err) return PyErr_Format(PyExc_OSError, "perf: can't parse sample, err=%d", err); -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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