From: Tony Jones <tonyj@xxxxxxx> [ Upstream commit 72e0b15cb24a497d7d0d4707cf51ff40c185ae8c ] With Python3. PyUnicode_FromStringAndSize is unsafe to call on attr and will return NULL. Use _PyBytes_FromStringAndSize (as with raw_buf). Below is the observed behavior without the fix. Note it is first necessary to apply the prior fix (Add trace_context extension module to sys,modules): # ldd /usr/bin/perf | grep -i python libpython3.6m.so.1.0 => /usr/lib64/libpython3.6m.so.1.0 (0x00007f8e1dfb2000) # perf record -e raw_syscalls:sys_enter /bin/false [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.018 MB perf.data (21 samples) ] # perf script -g python | cat generated Python script: perf-script.py # perf script -s ./perf-script.py in trace_begin Segmentation fault (core dumped) Signed-off-by: Tony Jones <tonyj@xxxxxxx> Acked-by: Jiri Olsa <jolsa@xxxxxxxxxx> Tested-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx> Cc: Jaroslav Škarvada <jskarvad@xxxxxxxxxx> Cc: Jonathan Corbet <corbet@xxxxxxx> Cc: Ravi Bangoria <ravi.bangoria@xxxxxxxxxxxxx> Cc: Seeteena Thoufeek <s1seetee@xxxxxxxxxxxxxxxxxx> Fixes: 66dfdff03d19 ("perf tools: Add Python 3 support") Link: http://lkml.kernel.org/r/20190124005229.16146-3-tonyj@xxxxxxx Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- tools/perf/util/scripting-engines/trace-event-python.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/tools/perf/util/scripting-engines/trace-event-python.c b/tools/perf/util/scripting-engines/trace-event-python.c index 87ef16a1b17e..2fe3cc43526f 100644 --- a/tools/perf/util/scripting-engines/trace-event-python.c +++ b/tools/perf/util/scripting-engines/trace-event-python.c @@ -733,8 +733,7 @@ static PyObject *get_perf_sample_dict(struct perf_sample *sample, Py_FatalError("couldn't create Python dictionary"); pydict_set_item_string_decref(dict, "ev_name", _PyUnicode_FromString(perf_evsel__name(evsel))); - pydict_set_item_string_decref(dict, "attr", _PyUnicode_FromStringAndSize( - (const char *)&evsel->attr, sizeof(evsel->attr))); + pydict_set_item_string_decref(dict, "attr", _PyBytes_FromStringAndSize((const char *)&evsel->attr, sizeof(evsel->attr))); pydict_set_item_string_decref(dict_sample, "pid", _PyLong_FromLong(sample->pid)); -- 2.19.1