linux-kernel - Re: [PATCH v2 3/5] rust: scatterlist: Add type-state abstraction for sg

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] [day] [month] [year] [list]

Message-Id: <DC9W8OMI5UT6.3RPWM2I4K10BS@kernel.org>
Date: Sat, 23 Aug 2025 16:57:26 +0200
From: "Danilo Krummrich" <dakr@...nel.org>
To: "Jason Gunthorpe" <jgg@...pe.ca>
Cc: "Alexandre Courbot" <acourbot@...dia.com>, <akpm@...ux-foundation.org>,
 <ojeda@...nel.org>, <alex.gaynor@...il.com>, <boqun.feng@...il.com>,
 <gary@...yguo.net>, <bjorn3_gh@...tonmail.com>, <lossin@...nel.org>,
 <a.hindborg@...nel.org>, <aliceryhl@...gle.com>, <tmgross@...ch.edu>,
 <abdiel.janulgue@...il.com>, <lyude@...hat.com>, <robin.murphy@....com>,
 <daniel.almeida@...labora.com>, <rust-for-linux@...r.kernel.org>,
 <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v2 3/5] rust: scatterlist: Add type-state abstraction
 for sg_table

On Sat Aug 23, 2025 at 4:32 PM CEST, Jason Gunthorpe wrote:
> Correct, this is misusing the API, and I don't know if the lengths are
> even guarenteed to be zero.

Hopefully it is. Otherwise, it's not only the documentation if sg_dma_address()
being wrong, but also a few drivers and maybe iommu_dma_unmap_sg(). However,
since it's a specific implementation of the API, it might be correct relying on
the sg_dma_len() == 0 check.

In any case, I think we can just use the nents field of struct sg_table, just
like for_each_sgtable_dma_sg() does.