Re: [PATCH v3 11/15] perf python: Add thread and PMU uninitialized checks

On Sun, Aug 9, 2026 at 10:02 PM Namhyung Kim <[email protected]> wrote:
>
> Hello,
>
> On Sun, Aug 09, 2026 at 07:28:09AM +0000, [email protected] wrote:
> > Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
> > - [Medium] The newly added `CHECK_INITIALIZED(ppmu->pmu, "pmu")` in `pyrf_pmu__events()` causes a Python object memory leak of `py_list` on the error path.
> > --
> >
> > --- Patch [11]: [PATCH v3 11/15] perf python: Add thread and PMU uninitialized checks ---
> > commit a381b82bb0eb00b93be525bfa1c265b574c03a5a
> > Author: Ian Rogers <[email protected]>
> >
> > perf python: Add thread and PMU uninitialized checks
> >
> > This commit adds CHECK_INITIALIZED guards to thread and PMU getters to
> > prevent crashes when accessed before proper initialization.
> >
> > > diff --git a/tools/perf/util/python.c b/tools/perf/util/python.c
> > > index c70b151428f76..fe5afce173330 100644
> > > --- a/tools/perf/util/python.c
> > > +++ b/tools/perf/util/python.c
> >
> > [ ... ]
> >
> > > @@ -1730,6 +1731,8 @@ static PyObject *pyrf_pmu__events(PyObject *self)
> > >     PyObject *py_list = PyList_New(0);
> > >     int ret;
> > >
> > > +   CHECK_INITIALIZED(ppmu->pmu, "pmu");
> > > +
> > >     if (!py_list)
> > >             return NULL;
> >
> > [Severity: Medium]
> > Does this code leak py_list if CHECK_INITIALIZED fails and returns early?
> >
> > Since py_list is allocated with PyList_New(0) just before the initialization
> > check, it appears this Python object is left orphaned if the macro evaluates
> > to true and forces an early return.
> >
> > Could the CHECK_INITIALIZED macro be moved to the beginning of
> > pyrf_pmu__events() before the PyList_New(0) allocation to avoid this leak?
>
> It seems this is the only issue introduced in this series.
> As it's trivial, I'll apply the following change for Ian.

Looks good to me. Thanks,
Ian

> Thanks,
> Namhyung
>
>
> diff --git a/tools/perf/util/python.c b/tools/perf/util/python.c
> index fe5afce1733306be..36c5f4b0d0bb15e7 100644
> --- a/tools/perf/util/python.c
> +++ b/tools/perf/util/python.c
> @@ -1728,11 +1728,12 @@ static int pyrf_pmu__events_cb(void *state, struct pmu_event_info *info)
>  static PyObject *pyrf_pmu__events(PyObject *self)
>  {
>         struct pyrf_pmu *ppmu = (void *)self;
> -       PyObject *py_list = PyList_New(0);
> +       PyObject *py_list;
>         int ret;
>
>         CHECK_INITIALIZED(ppmu->pmu, "pmu");
>
> +       py_list = PyList_New(0);
>         if (!py_list)
>                 return NULL;
>
>