Commit-ID: db0ba84c04ef2cf293aaada5ae97531127844d9d Gitweb: https://git.kernel.org/tip/db0ba84c04ef2cf293aaada5ae97531127844d9d Author: Janne Huttunen <[email protected]> AuthorDate: Mon, 9 Jul 2018 13:59:50 +0300 Committer: Arnaldo Carvalho de Melo <[email protected]> CommitDate: Wed, 11 Jul 2018 09:45:24 -0400
perf script python: Fix dict reference counting The dictionaries are attached to the parameter tuple that steals the references and takes care of releasing them when appropriate. The code should not decrement the reference counts explicitly. E.g. if libpython has been built with reference debugging enabled, the superfluous DECREFs will trigger this error when running perf script: Fatal Python error: Objects/tupleobject.c:238 object at 0x7f10f2041b40 has negative ref count -1 Aborted (core dumped) If the reference debugging is not enabled, the superfluous DECREFs might cause the dict objects to be silently released while they are still in use. This may trigger various other assertions or just cause perf crashes and/or weird and unexpected data changes in the stored Python objects. Signed-off-by: Janne Huttunen <[email protected]> Acked-by: Jiri Olsa <[email protected]> Acked-by: Namhyung Kim <[email protected]> Cc: Alexander Shishkin <[email protected]> Cc: Andi Kleen <[email protected]> Cc: Jaroslav Skarvada <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Peter Zijlstra <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]> --- 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 8b2eb6dbff4d..bc32e57d17be 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); }
