perf python: Decrement the refcount of just created event on failure

To avoid a leak if we have the python object but then something happens
and we need to return the operation, decrement the offset of the newly
created object.

Fixes: 377f698db12150a1 ("perf python: Add struct evsel into struct pyrf_event")
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Reviewed-by: Ian Rogers <irogers@google.com>
Link: https://lore.kernel.org/r/20250312203141.285263-5-acme@kernel.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>

diff --git a/tools/perf/util/python.c b/tools/perf/util/python.c
index f9491b6699764fbc093ec87687346b2b4d6262de..31a877a8eb8fbf09d67589e58743f2a080b69962 100644 (file)
--- a/tools/perf/util/python.c
+++ b/tools/perf/util/python.c
@@ -1012,6 +1012,7 @@ static PyObject *pyrf_evlist__read_on_cpu(struct pyrf_evlist *pevlist,
 
                evsel = evlist__event2evsel(evlist, event);
                if (!evsel) {
+                       Py_DECREF(pyevent);
                        Py_INCREF(Py_None);
                        return Py_None;
                }
@@ -1023,9 +1024,12 @@ static PyObject *pyrf_evlist__read_on_cpu(struct pyrf_evlist *pevlist,
                /* Consume the even only after we parsed it out. */
                perf_mmap__consume(&md->core);
 
-               if (err)
+               if (err) {
+                       Py_DECREF(pyevent);
                        return PyErr_Format(PyExc_OSError,
                                            "perf: can't parse sample, err=%d", err);
+               }
+
                return pyevent;
        }
 end: