From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751222AbaIJM4f (ORCPT ); Wed, 10 Sep 2014 08:56:35 -0400 Received: from mail-oi0-f47.google.com ([209.85.218.47]:34658 "EHLO mail-oi0-f47.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751053AbaIJM4e (ORCPT ); Wed, 10 Sep 2014 08:56:34 -0400 Message-ID: <54104A7F.2030509@mvista.com> Date: Wed, 10 Sep 2014 07:56:31 -0500 From: Corey Minyard User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.7.0 MIME-Version: 1.0 To: Takao Indoh CC: openipmi-developer@lists.sourceforge.net, linux-kernel@vger.kernel.org, gouji.masayuki@jp.fujitsu.com Subject: Re: [PATCH v2] ipmi: Clear drvdata when interface is removed References: <1410317770-4856-1-git-send-email-indou.takao@jp.fujitsu.com> In-Reply-To: <1410317770-4856-1-git-send-email-indou.takao@jp.fujitsu.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Ok, applied to my tree for 3.18. -corey On 09/09/2014 09:56 PM, Takao Indoh wrote: > This patch fixes a bug on hotmod removing. > > After ipmi interface is removed using hotmod, kernel panic occurs when > rmmod impi_si. For example, try this: > > # echo "remove,"`cat /proc/ipmi/0/params` > \ > /sys/module/ipmi_si/parameters/hotmod > # rmmod ipmi_si > > Then, rmmod fails with the following messages. > > ------------[ cut here ]------------ > WARNING: CPU: 12 PID: 10819 at /mnt/repos/linux/lib/list_debug.c:53 > __list_del_entry+0x63/0xd0() > (snip) > CPU: 12 PID: 10819 Comm: rmmod Not tainted 3.17.0-rc1 #19 > Hardware name: FUJITSU-SV PRIMERGY BX920 S2/D3030, BIOS 080015 > Rev.3D81.3030 02/10/2012 > 0000000000000009 ffff88022d547d40 ffffffff81575778 ffff88022d547d88 > ffff88022d547d78 ffffffff8104ec5d ffff88023908cdb0 ffffffffa06fa4e0 > ffff8800bac20860 0000000000000000 0000000002046090 ffff88022d547dd8 > Call Trace: > [] dump_stack+0x45/0x56 > [] warn_slowpath_common+0x7d/0xa0 > [] warn_slowpath_fmt+0x4c/0x50 > [] ? __kernfs_remove+0xdf/0x220 > [] __list_del_entry+0x63/0xd0 > [] list_del+0xd/0x30 > [] cleanup_one_si+0x2a/0x230 [ipmi_si] > [] ipmi_pnp_remove+0x15/0x20 [ipmi_si] > [] pnp_device_remove+0x24/0x40 > [] __device_release_driver+0x7f/0xf0 > [] driver_detach+0xb0/0xc0 > [] bus_remove_driver+0x55/0xd0 > [] driver_unregister+0x2c/0x50 > [] pnp_unregister_driver+0x12/0x20 > [] cleanup_ipmi_si+0xbc/0xf0 [ipmi_si] > [] SyS_delete_module+0x132/0x1c0 > [] ? do_notify_resume+0x59/0x80 > [] ? int_signal+0x12/0x17 > [] system_call_fastpath+0x16/0x1b > ---[ end trace 70b4377268f85c23 ]--- > > list_del in cleanup_one_si() fails because the smi_info is already > removed when hotmod removing. > > When ipmi interface is removed by hotmod, smi_info is removed by > cleanup_one_si(), but is is still set in drvdata. Therefore when rmmod > ipmi_si, ipmi_pnp_remove tries to remove it again and fails. > > By this patch, a pointer to smi_info in drvdata is cleared when hotmod > removing so that it will be not accessed when rmmod. > > changelog: > v2: > - Clear drvdata in cleanup_one_si > - Change subject > > v1: > https://lkml.org/lkml/2014/9/8/741 > > > Signed-off-by: Takao Indoh > --- > drivers/char/ipmi/ipmi_si_intf.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/char/ipmi/ipmi_si_intf.c b/drivers/char/ipmi/ipmi_si_intf.c > index 5d66568..01dcbdb 100644 > --- a/drivers/char/ipmi/ipmi_si_intf.c > +++ b/drivers/char/ipmi/ipmi_si_intf.c > @@ -3655,6 +3655,9 @@ static void cleanup_one_si(struct smi_info *to_clean) > if (!to_clean) > return; > > + if (to_clean->dev) > + dev_set_drvdata(to_clean->dev, NULL); > + > list_del(&to_clean->link); > > /* Tell the driver that we are shutting down. */