Re: [PATCH bpf-next v3 1/3] PM: wakeup: Handle empty list in wakeup_sources_walk

[Samuel Wu]

On Tue, Jan 27, 2026 at 8:15 AM Rafael J. Wysocki <raf...@kernel.org> wrote:
>
> On Sat, Jan 24, 2026 at 2:22 AM Samuel Wu <wusam...@google.com> wrote:
> >
> > In the case of an empty wakeup_sources list, wakeup_sources_walk_start()
> > will return an invalid but non-NULL address. This also affects wrappers
> > of the aforementioned function, like for_each_wakeup_source().
> >
> > This patch updates wakeup_sources_walk_start() to return NULL in case of
> > an empty list.
> >
> > Signed-off-by: Samuel Wu <wusam...@google.com>
> > ---
> >  drivers/base/power/wakeup.c | 4 +---
> >  1 file changed, 1 insertion(+), 3 deletions(-)
> >
> > diff --git a/drivers/base/power/wakeup.c b/drivers/base/power/wakeup.c
> > index 1e1a0e7eeac5..e69033d16fba 100644
> > --- a/drivers/base/power/wakeup.c
> > +++ b/drivers/base/power/wakeup.c
> > @@ -275,9 +275,7 @@ EXPORT_SYMBOL_GPL(wakeup_sources_read_unlock);
> >   */
> >  struct wakeup_source *wakeup_sources_walk_start(void)
> >  {
> > -       struct list_head *ws_head = &wakeup_sources;
> > -
> > -       return list_entry_rcu(ws_head->next, struct wakeup_source, entry);
> > +       return list_first_or_null_rcu(&wakeup_sources, struct 
> > wakeup_source, entry);
> >  }
> >  EXPORT_SYMBOL_GPL(wakeup_sources_walk_start);
> >
> > --
>
> This looks like a fix for the for_each_wakeup_source() users.
>
> I can apply it without the next two patches.

Yes please. Feel free to apply this patch independently, as it can
exist as a standalone fix independent of the subsequent two patches in
the series.

Thanks!