Re: [PATCH] pktcdvd : add kobject_put when kobject register fails

Dave Young
2007-12-04T08:00:45Z

On Dec 4, 2007 3:45 PM, Pekka Enberg <penberg@cs.helsinki.fi> wrote:
> Hi Dave,
>
> On Dec 4, 2007 3:31 AM, Dave Young <hidave.darkstar@gmail.com> wrote:
> > Kobject_put should be called when kobject register functioin fails, so the
> > the kobj ref count touch zero and then the proper cleanup routines will be
> > called.
>
> [snip]
>
> > diff -upr linux/drivers/block/pktcdvd.c linux.new/drivers/block/pktcdvd.c
> > --- linux/drivers/block/pktcdvd.c 2007-11-30 13:13:44.000000000 +0800
> > +++ linux.new/drivers/block/pktcdvd.c 2007-11-30 13:24:08.000000000 +0800
> > @@ -117,8 +117,10 @@ static struct pktcdvd_kobj* pkt_kobj_cre
> > p->kobj.parent = parent;
> > p->kobj.ktype = ktype;
> > p->pd = pd;
> > - if (kobject_register(&p->kobj) != 0)
> > + if (kobject_register(&p->kobj) != 0) {
> > + kobject_put(&p->kobj);
> > return NULL;
>
> This looks wrong to me. AFAICT the only thing that can fail
> kobject_register() is kobject_add() and it cleans up after itself. Am
> I missing something here?

Hi,
the kobject reference is get in kobject_init, and then kobject_add, if
kobject_add fail, it will only cleanup the reference got by itsself.

This topic is discussed in:
http://lkml.org/lkml/2007/11/30/9

Regards
dave
>
> Pekka
>