From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755493AbYIOX6R (ORCPT ); Mon, 15 Sep 2008 19:58:17 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754150AbYIOX6B (ORCPT ); Mon, 15 Sep 2008 19:58:01 -0400 Received: from cantor2.suse.de ([195.135.220.15]:39845 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753998AbYIOX6A (ORCPT ); Mon, 15 Sep 2008 19:58:00 -0400 Date: Mon, 15 Sep 2008 16:40:50 -0700 From: Greg KH To: Alexey Dobriyan Cc: linux-kernel@vger.kernel.org, akpm@osdl.org Subject: Re: [PATCH] Fix "notes" kobject leak Message-ID: <20080915234050.GA10876@suse.de> References: <20080830044246.GA26435@x200.localdomain> <20080830054343.GA16899@suse.de> <20080906054522.GA3191@x200.localdomain> <20080912155105.GA3526@suse.de> <20080914084225.GA3133@x200.localdomain> <20080915225322.GA4504@suse.de> <20080915233504.GB21012@x200.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20080915233504.GB21012@x200.localdomain> 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 On Tue, Sep 16, 2008 at 03:35:04AM +0400, Alexey Dobriyan wrote: > On Mon, Sep 15, 2008 at 03:53:22PM -0700, Greg KH wrote: > > On Sun, Sep 14, 2008 at 12:42:25PM +0400, Alexey Dobriyan wrote: > > > On Fri, Sep 12, 2008 at 08:51:05AM -0700, Greg KH wrote: > > > > On Sat, Sep 06, 2008 at 09:45:22AM +0400, Alexey Dobriyan wrote: > > > > > On Fri, Aug 29, 2008 at 10:43:43PM -0700, Greg KH wrote: > > > > > > On Sat, Aug 30, 2008 at 08:42:46AM +0400, Alexey Dobriyan wrote: > > > > > > > size-32: 3511 kvasprintf+0x57/0x90 > > > > > > > size-64: 3059 kobject_create+0x1c/0x40 > > > > > > > > > > > > > > These two buddies increase after every "modprobe; rmmod" sequence. > > > > > > > > > > > > Do they also do so in mainline? > > > > > > > > > > Yep, same bug in mainline. > > > > > > > > Not good. Does 2.6.26 show this as well? > > > > > > Uh-oh, this was actually 10-minute exercise. > > > > > > > > > > > > [PATCH] Fix "notes" kobject leak > > > > > > It happens every rmmod if KALLSYMS=y and SYSFS=y. > > > > > > # modprobe foo > > > > > > kobject: 'foo' (ffffffffa00743d0): kobject_add_internal: parent: 'module', set: 'module' > > > kobject: 'holders' (ffff88017e7c5770): kobject_add_internal: parent: 'foo', set: '' > > > kobject: 'foo' (ffffffffa00743d0): kobject_uevent_env > > > kobject: 'foo' (ffffffffa00743d0): fill_kobj_path: path = '/module/foo' > > > kobject: 'notes' (ffff88017fa9b668): kobject_add_internal: parent: 'foo', set: '' > > > ^^^^^ > > > > > > # rmmod foo > > > > > > kobject: 'holders' (ffff88017e7c5770): kobject_cleanup > > > kobject: 'holders' (ffff88017e7c5770): auto cleanup kobject_del > > > kobject: 'holders' (ffff88017e7c5770): calling ktype release > > > kobject: (ffff88017e7c5770): dynamic_kobj_release > > > kobject: 'holders': free name > > > kobject: 'foo' (ffffffffa00743d0): kobject_cleanup > > > kobject: 'foo' (ffffffffa00743d0): does not have a release() function, it is broken and must be fixed. > > > kobject: 'foo' (ffffffffa00743d0): auto cleanup 'remove' event > > > kobject: 'foo' (ffffffffa00743d0): kobject_uevent_env > > > kobject: 'foo' (ffffffffa00743d0): fill_kobj_path: path = '/module/foo' > > > kobject: 'foo' (ffffffffa00743d0): auto cleanup kobject_del > > > kobject: 'foo': free name > > > > > > [whooops] > > > > > > Signed-off-by: Alexey Dobriyan > > > --- > > > > > > kernel/module.c | 1 + > > > 1 file changed, 1 insertion(+) > > > > > > --- a/kernel/module.c > > > +++ b/kernel/module.c > > > @@ -1174,6 +1174,7 @@ static void free_notes_attrs(struct module_notes_attrs *notes_attrs, > > > sysfs_remove_bin_file(notes_attrs->dir, > > > ¬es_attrs->attrs[i]); > > > kobject_del(notes_attrs->dir); > > > + kobject_put(notes_attrs->dir); > > > > Hm, no, that should just be a call to kobject_put() instead of > > kobject_del(), can you try that instead and see if that solves the issue > > (am at a conference and can't test that at the moment, sorry.) > > Why?! kobject_del() puts parent kobject. And that's about it (well, it also tears down the sysfs stuff.) If you call kobject_put() instead, and it's the last put, it will also call kobject_del() and do everything else that it needs to do. Try it and let me know if I'm right or not :) thanks, greg k-h