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Date: Sat, 24 Jan 2026 20:08:28 +0100
Message-Id: <DFX20SA67PF2.VONCFNDOZOZT@kernel.org>
Subject: Re: [PATCH 0/3] Revert "revocable: Revocable resource management"
Cc: "Greg Kroah-Hartman" <gregkh@linuxfoundation.org>, "Rafael J . Wysocki"
 <rafael@kernel.org>, "Tzung-Bi Shih" <tzungbi@kernel.org>, "Bartosz
 Golaszewski" <bartosz.golaszewski@oss.qualcomm.com>, "Linus Walleij"
 <linusw@kernel.org>, "Jonathan Corbet" <corbet@lwn.net>, "Shuah Khan"
 <shuah@kernel.org>, "Laurent Pinchart" <laurent.pinchart@ideasonboard.com>,
 "Wolfram Sang" <wsa+renesas@sang-engineering.com>, "Simona Vetter"
 <simona.vetter@ffwll.ch>, "Dan Williams" <dan.j.williams@intel.com>, "Jason
 Gunthorpe" <jgg@nvidia.com>, <linux-doc@vger.kernel.org>,
 <linux-kselftest@vger.kernel.org>, <linux-kernel@vger.kernel.org>
To: "Johan Hovold" <johan@kernel.org>
From: "Danilo Krummrich" <dakr@kernel.org>
References: <20260124170535.11756-1-johan@kernel.org>
In-Reply-To: <20260124170535.11756-1-johan@kernel.org>

On Sat Jan 24, 2026 at 6:05 PM CET, Johan Hovold wrote:
> this does not look like the right interface for the chardev unplug issue.

I think it depends, we should do everything to prevent having the issue in =
the
first place, e.g. ensure that we synchronize the unplug properly on device
driver unbind.

Sometimes, however, this isn't possible; this is where a revocable mechanis=
m can
come in handy to prevent UAF of device resources -- DRM is a good example f=
or
this.

But to be fair, I also want to point out that there is a quite significant
difference regarding the usefulness of the revocable concept in C compared =
to in
Rust due to language capabilities.