From 83428f2fad48e16fddff0cb445cb4fedf5afe4ab Mon Sep 17 00:00:00 2001
From: Petr Machata <petrm@mellanox.com>
Date: Thu, 22 Mar 2018 00:57:32 +0100
Subject: [PATCH] perf python: Reference Py_None before returning it

Python None objects are handled just like all the other objects with
respect to their reference counting. Before returning Py_None, its
reference count thus needs to be bumped.

Signed-off-by: Petr Machata <petrm@mellanox.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Petr Machata <petrm@mellanox.com>
Link: http://lkml.kernel.org/r/b1e565ecccf68064d8d54f37db5d028dda8fa522.1521675563.git.petrm@mellanox.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/util/python.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/tools/perf/util/python.c b/tools/perf/util/python.c
index b956868fd445..863b61478edd 100644
--- a/tools/perf/util/python.c
+++ b/tools/perf/util/python.c
@@ -1004,8 +1004,10 @@ static PyObject *pyrf_evlist__read_on_cpu(struct pyrf_evlist *pevlist,
 			return PyErr_NoMemory();
 
 		evsel = perf_evlist__event2evsel(evlist, event);
-		if (!evsel)
+		if (!evsel) {
+			Py_INCREF(Py_None);
 			return Py_None;
+		}
 
 		pevent->evsel = evsel;