[PATCH] perf script python: Fix dict reference counting

[Janne Huttunen]

The dictionaries are attached to the parameter tuple that steals the
references. The code should not decrement the reference counters
explicitly. Otherwise the objects might be released while they are
still in use which may cause perf crashes, assertions or just plain
weird behavior like unexpected data changes in stored objects.

Signed-off-by: Janne Huttunen <janne.huttunen@xxxxxxxxx>
---
 tools/perf/util/scripting-engines/trace-event-python.c | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/tools/perf/util/scripting-engines/trace-event-python.c b/tools/perf/util/scripting-engines/trace-event-python.c
index 46e9e19..60fce44 100644
--- a/tools/perf/util/scripting-engines/trace-event-python.c
+++ b/tools/perf/util/scripting-engines/trace-event-python.c
@@ -908,14 +908,11 @@ static void python_process_tracepoint(struct perf_sample *sample,
 	if (_PyTuple_Resize(&t, n) == -1)
 		Py_FatalError("error resizing Python tuple");
 
-	if (!dict) {
+	if (!dict)
 		call_object(handler, t, handler_name);
-	} else {
+	else
 		call_object(handler, t, default_handler_name);
-		Py_DECREF(dict);
-	}
 
-	Py_XDECREF(all_entries_dict);
 	Py_DECREF(t);
 }
 
@@ -1235,7 +1232,6 @@ static void python_process_general_event(struct perf_sample *sample,
 
 	call_object(handler, t, handler_name);
 
-	Py_DECREF(dict);
 	Py_DECREF(t);
 }
 
-- 
2.5.5