Re: [PATCH] kobject: Make sure the parent does not get released before its children

From: Heikki Krogerus
Date: Thu May 14 2020 - 02:54:22 EST


On Wed, May 13, 2020 at 04:14:51PM -0700, Randy Dunlap wrote:
> On 5/13/20 2:30 PM, Brendan Higgins wrote:
> > On Wed, May 13, 2020 at 8:18 AM Heikki Krogerus
> > <heikki.krogerus@xxxxxxxxxxxxxxx> wrote:
> >>
> >> In the function kobject_cleanup(), kobject_del(kobj) is
> >> called before the kobj->release(). That makes it possible to
> >> release the parent of the kobject before the kobject itself.
> >>
> >> To fix that, adding function __kboject_del() that does
> >> everything that kobject_del() does except release the parent
> >> reference. kobject_cleanup() then calls __kobject_del()
> >> instead of kobject_del(), and separately decrements the
> >> reference count of the parent kobject after kobj->release()
> >> has been called.
> >>
> >> Reported-by: Naresh Kamboju <naresh.kamboju@xxxxxxxxxx>
> >> Reported-by: kernel test robot <rong.a.chen@xxxxxxxxx>
> >> Fixes: 7589238a8cf3 ("Revert "software node: Simplify software_node_release() function"")
> >> Cc: Brendan Higgins <brendanhiggins@xxxxxxxxxx>
> >> Cc: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
> >> Suggested-by: "Rafael J. Wysocki" <rafael@xxxxxxxxxx>
> >> Signed-off-by: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
> >
> > Reviewed-by: Brendan Higgins <brendanhiggins@xxxxxxxxxx>
> > Tested-by: Brendan Higgins <brendanhiggins@xxxxxxxxxx>
> >
>
> Acked-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
> Tested-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>

Thanks guys. Sorry about the mix-up.

Br,

--
heikki