4.19-stable review patch. If anyone has any objections, please let me know.
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[ 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@suse.de Acked-by: Jiri Olsa jolsa@kernel.org Tested-by: Arnaldo Carvalho de Melo acme@redhat.com Cc: Jaroslav Škarvada jskarvad@redhat.com Cc: Jonathan Corbet corbet@lwn.net Cc: Ravi Bangoria ravi.bangoria@linux.ibm.com Cc: Seeteena Thoufeek s1seetee@linux.vnet.ibm.com Fixes: 66dfdff03d19 ("perf tools: Add Python 3 support") Link: http://lkml.kernel.org/r/20190124005229.16146-3-tonyj@suse.de Signed-off-by: Arnaldo Carvalho de Melo acme@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- 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 05d95de14e20..fb11396ec861 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));