Re: [PATCH 4/8] livepatch: Add an extra flag to distinguish registered patches

From: Josh Poimboeuf
Date: Tue Apr 10 2018 - 13:53:39 EST


On Tue, Apr 10, 2018 at 12:56:25PM +0200, Petr Mladek wrote:
> > > diff --git a/include/linux/livepatch.h b/include/linux/livepatch.h
> > > index f28af280f9e0..d6e6d8176995 100644
> > > --- a/include/linux/livepatch.h
> > > +++ b/include/linux/livepatch.h
> > > @@ -378,7 +383,7 @@ int klp_disable_patch(struct klp_patch *patch)
> > >
> > > mutex_lock(&klp_mutex);
> > >
> > > - if (!klp_is_patch_registered(patch)) {
> > > + if (!patch->registered) {
> >
> > I don't see any actual problem, but I'd feel safer if we preserve
> > klp_is_patch_on_stack() even somewhere in disable path.
>
> It is strictly needed in klp_enable_patch() which will be better
> visible if I squash it with the next patch.
>
> The use in klp_disable_patch() is optional. I do not have problems
> to add it there though. If Josh does not see it as too paranoid,
> I'll add it.

That does seem pointless to me, how did you know? :-)

Of course if we make the other changes we've been discussing, maybe it's
no longer an issue.

--
Josh