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

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Message-ID: <e51d4ce4-42ba-8c89-21b4-082c7158a9a9@infradead.org>
Date:   Wed, 13 May 2020 16:14:51 -0700
From:   Randy Dunlap <rdunlap@...radead.org>
To:     Brendan Higgins <brendanhiggins@...gle.com>,
        Heikki Krogerus <heikki.krogerus@...ux.intel.com>
Cc:     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 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.
-- 
~Randy