Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755392AbYLESrm (ORCPT ); Fri, 5 Dec 2008 13:47:42 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753555AbYLESrc (ORCPT ); Fri, 5 Dec 2008 13:47:32 -0500 Received: from cantor.suse.de ([195.135.220.2]:34668 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752541AbYLESrb (ORCPT ); Fri, 5 Dec 2008 13:47:31 -0500 Date: Fri, 5 Dec 2008 10:46:03 -0800 From: Greg KH To: Mark McLoughlin Cc: Jiri Slaby , Michael Tokarev , Rusty Russell , linux-kernel , kvm , Anthony Liguori Subject: Re: [PATCH] virtio: make PCI devices take a virtio_pci module ref Message-ID: <20081205184603.GC13133@suse.de> References: <1228394671.3732.77.camel@blaa> <49385DB7.4060306@gmail.com> <4938EE0B.8020501@msgid.tls.msk.ru> <493929D2.4070900@gmail.com> <1228488921.3858.25.camel@blaa> <493947EB.3050404@gmail.com> <20081205152644.GA27847@suse.de> <1228501817.3858.48.camel@blaa> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1228501817.3858.48.camel@blaa> User-Agent: Mutt/1.5.16 (2007-06-09) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2465 Lines: 61 On Fri, Dec 05, 2008 at 06:30:17PM +0000, Mark McLoughlin wrote: > On Fri, 2008-12-05 at 07:26 -0800, Greg KH wrote: > > On Fri, Dec 05, 2008 at 04:25:31PM +0100, Jiri Slaby wrote: > > > Mark McLoughlin wrote: > > > >> Fix the virtio bus instead. > > > > > > > > Yeah, the patch I posted wasn't meant as a fix for this traceback. > > > > > > So what's the module_get patch needed for? > > > > > > > Here's one that does fix it. > > > ... > > > > From: Mark McLoughlin > > > > Subject: [PATCH] virtio: add device release() function > > > > > > > > Add a release() function for virtio_pci devices so as to avoid: > > > > > > > > Device 'virtio0' does not have a release() function, it is broken and must be fixed > > > > Just providing an empty release function to the kernel is the complete > > wrong thing. Do you not think the kernel is actually trying to tell you > > something here? If it could test for an empty release function it would > > complain about that as well, providing one is no "fix" at all. > > > > You need to free your memory in the release function that is owned by > > the device/structure. Please read the file, Documentation/kobject.txt > > for details as to what you need to do. > > Okay, consider me "mocked mercilessly by the kobject maintainer" :-) Heh, prepare for some more mocking below... > Does this version look a bit more reasonable? > > (The virtio_pci_root is statically allocated so I don't see how > release() could be non-empty in this case, but let's debate whether we > want to keep this dummy device at all) You should NEVER declare a kobject statically. There should be a check in the kernel that complains about this on some arches in the -mm and -next trees, I'm supprised you didn't hit it. To quote from the kobject.txt documentation file: Because kobjects are dynamic, they must not be declared statically or on the stack, but instead, always allocated dynamically. Future versions of the kernel will contain a run-time check for kobjects that are created statically and will warn the developer of this improper usage. That is why you need a "real" release function. So, care to respin this again please? thanks, greg k-h -- 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/