From: Tejun Heo <tj@kernel.org>
To: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>,
Borislav Petkov <petkovbb@googlemail.com>,
David Airlie <airlied@linux.ie>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Greg KH <greg@kroah.com>, Al Viro <viro@ZenIV.linux.org.uk>
Subject: Re: drm_vm.c:drm_mmap: possible circular locking dependency detected
Date: Tue, 05 Jan 2010 08:09:59 +0900 [thread overview]
Message-ID: <4B427547.5070109@kernel.org> (raw)
In-Reply-To: <m14on1fygh.fsf@fess.ebiederm.org>
Hello,
On 01/05/2010 04:43 AM, Eric W. Biederman wrote:
>>> So it is unlikely but possible to deadlock by accessing a serio
>>> attribute of a serio device that is being removed.
>>
>> Hmm, I guess I was too quick dismissing lockdep complaints here. Now
>> that sysfs remove waits deadlock indeed is possible. Actually the locks
>> on serio->drv_mutex in attributes were added to make sure we don't
>> access device that was unbound from the driver through stale sysfs
>> attributes.
>
> Cool. So we have solved the problem generically but we have left over
> layer specific solutions. That seems like a good problem to have.
This is way too cool. Only if we can have more moments like this. :-)
--
tejun
next prev parent reply other threads:[~2010-01-04 23:04 UTC|newest]
Thread overview: 60+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-12-24 22:00 Linux 2.6.33-rc2 - Merry Christmas Linus Torvalds
2009-12-25 10:27 ` -tip: origin tree boot crash Ingo Molnar
2009-12-25 19:49 ` Dmitry Torokhov
2009-12-26 20:19 ` Len Brown
2009-12-26 20:17 ` Len Brown
2009-12-27 4:20 ` Len Brown
2009-12-28 9:44 ` Ingo Molnar
2009-12-28 12:01 ` Ingo Molnar
2009-12-28 15:02 ` Paul Rolland
2009-12-28 16:15 ` Paul Rolland
2009-12-28 16:53 ` Paul Rolland
2009-12-28 20:17 ` Dmitry Torokhov
2009-12-30 6:14 ` Len Brown
2009-12-30 7:13 ` Paul Rolland
2009-12-30 6:19 ` [PATCH] wmi: check find_guid() return value to prevent oops Len Brown
2009-12-30 6:21 ` [PATCH] dell-wmi: sys_init_module: 'dell_wmi'->init suspiciously returned 21, it should follow 0/-E convention Len Brown
2009-12-25 13:10 ` Linux 2.6.33-rc2 - Blank screen for Intel KMS Miguel Calleja
2009-12-29 9:50 ` Miguel Calleja
2009-12-29 14:01 ` Rafael J. Wysocki
2009-12-25 20:00 ` Linux 2.6.33-rc2 - Merry Christmas Borislav Petkov
2009-12-25 21:50 ` Borislav Petkov
2009-12-26 6:00 ` Jesse Barnes
2009-12-26 8:02 ` Borislav Petkov
2009-12-26 9:36 ` EHCI resume sysfs duplicates (was: Re: Linux 2.6.33-rc2 - Merry Christmas ...) Borislav Petkov
2009-12-26 9:45 ` drm_vm.c:drm_mmap: possible circular locking dependency detected " Borislav Petkov
2009-12-28 0:40 ` KOSAKI Motohiro
2009-12-30 21:10 ` Linus Torvalds
2009-12-30 21:34 ` Eric W. Biederman
2009-12-30 22:03 ` Linus Torvalds
2009-12-31 8:40 ` Eric W. Biederman
2009-12-31 19:04 ` Linus Torvalds
2010-01-01 13:58 ` [PATCH] sysfs: Cache the last sysfs_dirent to improve readdir scalability Eric W. Biederman
2010-01-01 15:33 ` Borislav Petkov
2010-01-01 18:56 ` Linus Torvalds
2010-01-01 22:43 ` [PATCH] sysfs: Cache the last sysfs_dirent to improve readdir scalability v2 Eric W. Biederman
2010-01-01 23:10 ` Linus Torvalds
2010-01-02 5:59 ` Greg KH
2010-01-02 15:40 ` Borislav Petkov
2010-01-01 15:16 ` drm_vm.c:drm_mmap: possible circular locking dependency detected (was: Re: Linux 2.6.33-rc2 - Merry Christmas ...) Eric W. Biederman
2010-01-02 2:59 ` drm_vm.c:drm_mmap: possible circular locking dependency detected Tejun Heo
2010-01-02 21:37 ` [PATCH] sysfs: Add lockdep annotations for the sysfs active reference Eric W. Biederman
2010-01-03 0:02 ` Tejun Heo
2010-01-17 16:26 ` Ming Lei
2010-01-17 17:18 ` Eric W. Biederman
2010-01-17 18:03 ` Dominik Brodowski
2010-01-02 21:49 ` drm_vm.c:drm_mmap: possible circular locking dependency detected Eric W. Biederman
2010-01-03 0:32 ` Tejun Heo
2010-01-03 2:06 ` Eric W. Biederman
2010-01-03 5:01 ` Tejun Heo
2010-01-03 5:38 ` Eric W. Biederman
2010-01-03 6:05 ` Tejun Heo
2010-01-03 7:47 ` Dmitry Torokhov
2010-01-03 10:57 ` Eric W. Biederman
2010-01-03 11:14 ` Eric W. Biederman
2010-01-04 19:16 ` Dmitry Torokhov
2010-01-04 18:57 ` Dmitry Torokhov
2010-01-04 19:43 ` Eric W. Biederman
2010-01-04 21:12 ` Dmitry Torokhov
2010-01-04 23:09 ` Tejun Heo [this message]
2009-12-31 8:40 ` drm_vm.c:drm_mmap: possible circular locking dependency detected (was: Re: Linux 2.6.33-rc2 - Merry Christmas ...) Eric W. Biederman
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