linux-kernel - Re: [PATCH v2 2/4] dma-buf: Document revoke semantics

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: Windows password security audit tool. GUI, reports in PDF.

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

Message-ID: <20260119164619.GG961572@ziepe.ca>
Date: Mon, 19 Jan 2026 12:46:19 -0400
From: Jason Gunthorpe <jgg@...pe.ca>
To: Thomas Hellström <thomas.hellstrom@...ux.intel.com>
Cc: Leon Romanovsky <leon@...nel.org>,
	Sumit Semwal <sumit.semwal@...aro.org>,
	Christian König <christian.koenig@....com>,
	Alex Deucher <alexander.deucher@....com>,
	David Airlie <airlied@...il.com>, Simona Vetter <simona@...ll.ch>,
	Gerd Hoffmann <kraxel@...hat.com>,
	Dmitry Osipenko <dmitry.osipenko@...labora.com>,
	Gurchetan Singh <gurchetansingh@...omium.org>,
	Chia-I Wu <olvaffe@...il.com>,
	Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>,
	Maxime Ripard <mripard@...nel.org>,
	Thomas Zimmermann <tzimmermann@...e.de>,
	Lucas De Marchi <lucas.demarchi@...el.com>,
	Rodrigo Vivi <rodrigo.vivi@...el.com>,
	Kevin Tian <kevin.tian@...el.com>, Joerg Roedel <joro@...tes.org>,
	Will Deacon <will@...nel.org>, Robin Murphy <robin.murphy@....com>,
	Alex Williamson <alex@...zbot.org>, linux-media@...r.kernel.org,
	dri-devel@...ts.freedesktop.org, linaro-mm-sig@...ts.linaro.org,
	linux-kernel@...r.kernel.org, amd-gfx@...ts.freedesktop.org,
	virtualization@...ts.linux.dev, intel-xe@...ts.freedesktop.org,
	linux-rdma@...r.kernel.org, iommu@...ts.linux.dev,
	kvm@...r.kernel.org
Subject: Re: [PATCH v2 2/4] dma-buf: Document revoke semantics

On Sun, Jan 18, 2026 at 03:29:02PM +0100, Thomas Hellström wrote:
> Why would the importer want to verify the exporter's support for
> revocation? If the exporter doesn't support it, the only consequence
> would be that invalidate_mappings() would never be called, and that
> dma_buf_pin() is a NOP. Besides, dma_buf_pin() would not return an
> error if the exporter doesn't implement the pin() callback?

I think the comment and commit message should be clarified that 
dma_buf_attachment_is_revoke() is called by the exporter.

The purpose is for the exporter that wants to call move_notify() on a
pinned DMABUF to determine if the importer is going to support it.

Jason