Re: [PATCH 1/2] livepatch: Remove custom kobject state handling

From: Greg Kroah-Hartman
Date: Tue May 07 2019 - 09:07:12 EST

On Tue, May 07, 2019 at 02:32:57PM +0200, Miroslav Benes wrote:
> On Fri, 3 May 2019, Petr Mladek wrote:
> > kobject_init() always succeeds and sets the reference count to 1.
> > It allows to always free the structures via kobject_put() and
> > the related release callback.
> >
> > Note that the custom kobject state handling was used only
> > because we did not know that kobject_put() can and actually
> > should get called even when kobject_init_and_add() fails.
> >
> > The patch should not change the existing behavior.
> Pity that the changelog does not describe the change from
> kobject_init_and_add() to two-stage kobject init (separate kobject_init()
> and kobject_add()).
> Petr changed it, because now each member of new dynamic lists (created in
> klp_init_patch_early()) is initialized with kobject_init(), so we do not
> have to worry about calling kobject_put() (this is slightly different from
> kobj_added).
> It would also be possible to retain kobject_init_and_add() and move it to
> klp_init_patch_early(), but it would be uglier in my opinion.

kobject_init_and_add() is only there for the "simple" use cases.
There's no problem with doing the two-stage process on your own like
this, that's exactly what it is there for :)


greg k-h