From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753312AbXCaQOZ (ORCPT ); Sat, 31 Mar 2007 12:14:25 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753316AbXCaQOZ (ORCPT ); Sat, 31 Mar 2007 12:14:25 -0400 Received: from wr-out-0506.google.com ([64.233.184.225]:42194 "EHLO wr-out-0506.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753314AbXCaQOX (ORCPT ); Sat, 31 Mar 2007 12:14:23 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:message-id:date:from:user-agent:mime-version:to:cc:subject:references:in-reply-to:content-type:content-transfer-encoding; b=JZcw+3XjlaO/e64bI5bLAY/PYHuyKkqj1k5SZwUCBU/bRC5LzWssLdPBk/0rHTeagWDhCvGgZ6UTlj593tXJEiNaIEaijw23yIvlFWEcy6rtoz0JUWus/clPnKcwFs16cxwOmn+8VOxyC0xsGF+oi7i+1tEz+PKX1mkicvdVxdE= Message-ID: <460E88D7.3010702@gmail.com> Date: Sun, 01 Apr 2007 01:14:15 +0900 From: Tejun Heo User-Agent: Icedove 1.5.0.10 (X11/20070307) MIME-Version: 1.0 To: Cornelia Huck CC: gregkh@suse.de, hugh@veritas.com, dmitry.torokhov@gmail.com, oneukum@suse.de, maneesh@in.ibm.com, rpurdie@rpsys.net, James.Bottomley@SteelEye.com, Jeff Garzik , lkml , "linux-ide@vger.kernel.org" , SCSI Mailing List Subject: Re: [RFD driver-core] Lifetime problems of the current driver model References: <460CDBA6.5030608@gmail.com> <20070330151926.18fc12a0@gondolin.boeblingen.de.ibm.com> <460D0E78.3040200@gmail.com> <20070330154042.4c7deb72@gondolin.boeblingen.de.ibm.com> <460D178F.4000500@gmail.com> <20070330165251.7beffc7c@gondolin.boeblingen.de.ibm.com> <460D27E3.2050602@gmail.com> <20070330213101.7aa7babf@gondolin.boeblingen.de.ibm.com> <460DD1B0.4080605@gmail.com> <20070331180806.55d572c8@gondolin.boeblingen.de.ibm.com> In-Reply-To: <20070331180806.55d572c8@gondolin.boeblingen.de.ibm.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Cornelia Huck wrote: > On Sat, 31 Mar 2007 12:12:48 +0900, > Tejun Heo wrote: > >>> Hm, but as long as dk0 is registered, it can be looked up and someone >>> could get a reference on it. >> Yeah, exactly. That's why any getting any kobject reference backed by a >> module must be accompanied by try_module_get(). >> >> int mydrv_get_dk(struct dk *dk) >> { >> rc = try_module_get(mydrv); >> if (rc) >> return rc; >> kobject_get(&dk->kobj); >> return 0; >> } > > This works if the caller always knows which module to grab (I was > thinking about some tree-walking code). Yeah, that's why we have so many ->owner's and getting it wrong results in jumping to non-existent address. -- tejun