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 <to...@suse.de> Cc: Jaroslav Škarvada <jskar...@redhat.com> Fixes: 66dfdff03d196e51322c6a85c0d8db8bb2bdd655 --- 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 40300d8e80a7..777c97b13905 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)); -- 2.20.1