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

[Randy Dunlap]

On 5/13/20 1:18 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.
> 
> I was starting to wonder if anything else needed to happen with this. :-)
> 
> Thanks for taking care of this!
> 
>> 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>
> 
> Didn't I and someone else test this?
> 
> Either way, I will test this out in a little bit.
> 
> Thanks!
> 

Yes, I tested the earlier patch and acked it.
(using lib/test_printf.ko)

-- 
~Randy