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

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Date:   Thu, 14 May 2020 09:54:15 +0300
From:   Heikki Krogerus <heikki.krogerus@...ux.intel.com>
To:     Randy Dunlap <rdunlap@...radead.org>
Cc:     Brendan Higgins <brendanhiggins@...gle.com>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        Naresh Kamboju <naresh.kamboju@...aro.org>,
        kernel test robot <rong.a.chen@...el.com>,
        "Rafael J. Wysocki" <rafael@...nel.org>
Subject: Re: [PATCH] kobject: Make sure the parent does not get released
 before its children

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@...ux.intel.com> 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@...aro.org>
> >> Reported-by: kernel test robot <rong.a.chen@...el.com>
> >> Fixes: 7589238a8cf3 ("Revert "software node: Simplify software_node_release() function"")
> >> Cc: Brendan Higgins <brendanhiggins@...gle.com>
> >> Cc: Randy Dunlap <rdunlap@...radead.org>
> >> Suggested-by: "Rafael J. Wysocki" <rafael@...nel.org>
> >> Signed-off-by: Heikki Krogerus <heikki.krogerus@...ux.intel.com>
> > 
> > Reviewed-by: Brendan Higgins <brendanhiggins@...gle.com>
> > Tested-by: Brendan Higgins <brendanhiggins@...gle.com>
> > 
> 
> Acked-by: Randy Dunlap <rdunlap@...radead.org>
> Tested-by: Randy Dunlap <rdunlap@...radead.org>

Thanks guys. Sorry about the mix-up.

Br,

-- 
heikki