linux-kernel - Re: [PATCH] workqueue: Remove incorrect "WARN_ON_ONCE(!list_empty(&worker->entry));" from dying worker

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <87wml4s9zz.fsf@linux.ibm.com>
Date: Mon, 29 Jul 2024 13:39:12 +0200
From: "Marc Hartmayer" <mhartmay@...ux.ibm.com>
To: Lai Jiangshan <jiangshanlai@...il.com>, linux-kernel@...r.kernel.org
Cc: Lai Jiangshan <jiangshan.ljs@...group.com>, Tejun Heo <tj@...nel.org>
Subject: Re: [PATCH] workqueue: Remove incorrect
 "WARN_ON_ONCE(!list_empty(&worker->entry));" from dying worker

On Thu, Jul 25, 2024 at 09:04 AM +0800, Lai Jiangshan <jiangshanlai@...il.com> wrote:
> From: Lai Jiangshan <jiangshan.ljs@...group.com>
>
> The commit 68f83057b913 ("workqueue: Reap workers via kthread_stop()
> and remove detach_completion") changes the procedure of destroying
> workers; the dying workers are kept in the cull_list in wake_dying_workers()
> with the pool lock held and removed from the cull_list by the newly
> added reap_dying_workers() without the pool lock.
>
> This can cause a warning if the dying worker is wokenup earlier than
> reaped as reported by Marc:
>

[…snip]

The crash I reported is fixed by this patch. But I can't say whether the
removal of the warning is OK.

--

Kind regards / Beste Grüße
   Marc Hartmayer

IBM Deutschland Research & Development GmbH
Vorsitzender des Aufsichtsrats: Wolfgang Wendt
Geschäftsführung: David Faller
Sitz der Gesellschaft: Böblingen
Registergericht: Amtsgericht Stuttgart, HRB 243294