From: Johannes Berg <johannes@sipsolutions.net>
To: Maarten Lankhorst <dev@lankhorst.se>, linux-kernel@vger.kernel.org
Cc: intel-xe@lists.freedesktop.org,
Mukesh Ojha <quic_mojha@quicinc.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
"Rafael J. Wysocki" <rafael@kernel.org>,
Danilo Krummrich <dakr@kernel.org>,
stable@vger.kernel.org, Matthew Brost <matthew.brost@intel.com>
Subject: Re: [PATCH] devcoredump: Fix circular locking dependency with devcd->mutex.
Date: Fri, 24 Oct 2025 10:39:39 +0200 [thread overview]
Message-ID: <247568f47e1955be454e951e80a9063123f97c66.camel@sipsolutions.net> (raw)
In-Reply-To: <c4bd0ddb-4104-4074-b04a-27577afeaa46@lankhorst.se>
On Fri, 2025-10-24 at 10:37 +0200, Maarten Lankhorst wrote:
> >
> > CPU 0 CPU 1
> >
> > dev_coredump_put() devcd_del()
> > -> devcd_free()
> > -> locked
> > -> !deleted
> > -> __devcd_del()
> > -> __devcd_del()
> >
> > no?
> >
> > johannes
>
>
> Yeah don't you love the races in the design? All intricate and subtle.
:)
> In this case it's handled by disable_delayed_work_sync(),
> which waits for devcd_del() to be completed. devcd_del is called from the workqueue,
> and the first step devcd_free does is calling disable_delayed_work_sync, which means
> devcd_del() either fully completed or was not run at all.
Oh... right, I totally missed the _sync. My bad, sorry.
I guess I really should say
Reviewed-by: Johannes Berg <johannes@sipsolutions.net>
since I finally _did_ review it carefully. Sorry it took forever.
johannes
next prev parent reply other threads:[~2025-10-24 8:39 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-07-23 14:24 Maarten Lankhorst
2025-10-03 13:29 ` Maarten Lankhorst
2025-10-03 18:00 ` Mukesh Ojha
2025-10-06 9:11 ` Maarten Lankhorst
2025-10-06 9:24 ` Greg Kroah-Hartman
2025-10-24 8:12 ` Johannes Berg
2025-10-24 8:37 ` Maarten Lankhorst
2025-10-24 8:39 ` Johannes Berg [this message]
2025-10-24 10:27 ` Maarten Lankhorst
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