Messages in this thread Patch in this message | | | Date | Fri, 30 Nov 2007 13:57:02 +0800 | From | Dave Young <> | Subject | Re: [RFC] Sample kset/ktype/kobject implementation |
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On Fri, Nov 30, 2007 at 01:07:37PM +0800, Dave Young wrote: > On Nov 30, 2007 6:11 AM, Alan Stern <stern@rowland.harvard.edu> wrote: > > On Thu, 29 Nov 2007, Greg KH wrote: > > > > > > > > kobject_put(foo) is needed since it gets you through kobject_cleanup() > > > > > > where the name can be freed. > > > > > > > > > > No, kobject_register() should have handled that for us, right? > > > > > > > > kobject_register() doesn't do a kobject_put() if kobject_add() failed. > > > > > > Crap. If I can't get this code right in an example, the API is messed > > > up. Time to take Kay seriously and start to revamp the basic kobject > > > api :) > > > > The rule is simple enough. After calling kobject_register() you should > > always use kobject_put() -- even if kobject_register() failed. > > > > In fact, after calling kobject_init() you should use kobject_put(). > > The first rule follows from this one, since kobject_register() calls > > kobject_init() internally. > > > Hi, > The behavior is not very clear here, the root problem is that : > > 1. Should we call kobject_put so cleanup work can be done by refcount > touch zero or call kfree every time after kobject_register failed? > > 2. If kobject_put calling is true, should this be done in > kobject_register error handling codes or by hand after > kobject_register failed? > IMO,I'd rather select kobject_put due to the kobj name should also be released. After searching for kobject_register, I found one leaks as this issue in pktcdvd.
Signed-off-by: Dave Young <hidave.darkstar@gmail.com>
--- drivers/block/pktcdvd.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
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; + } return p; } /* > Regards > dave > > Alan Stern > > > > > > - > > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > > the body of a message to majordomo@vger.kernel.org > > More majordomo info at http://vger.kernel.org/majordomo-info.html > > Please read the FAQ at http://www.tux.org/lkml/ > > - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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