linux-kernel - Re: [PATCH v5 1/2] rust: add `Alignment` type

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: <DCO2UHSV1FJH.146QJD3UR8FVR@nvidia.com>
Date: Tue, 09 Sep 2025 16:05:22 +0900
From: "Alexandre Courbot" <acourbot@...dia.com>
To: "Miguel Ojeda" <miguel.ojeda.sandonis@...il.com>
Cc: "Miguel Ojeda" <ojeda@...nel.org>, "Alex Gaynor"
 <alex.gaynor@...il.com>, "Boqun Feng" <boqun.feng@...il.com>, "Gary Guo"
 <gary@...yguo.net>, Björn Roy Baron
 <bjorn3_gh@...tonmail.com>, "Benno Lossin" <lossin@...nel.org>, "Andreas
 Hindborg" <a.hindborg@...nel.org>, "Alice Ryhl" <aliceryhl@...gle.com>,
 "Trevor Gross" <tmgross@...ch.edu>, "Danilo Krummrich" <dakr@...nel.org>,
 <linux-kernel@...r.kernel.org>, <rust-for-linux@...r.kernel.org>,
 <nouveau@...ts.freedesktop.org>
Subject: Re: [PATCH v5 1/2] rust: add `Alignment` type

Hi Miguel,

On Mon Sep 8, 2025 at 11:21 PM JST, Miguel Ojeda wrote:
> On Mon, Sep 8, 2025 at 3:26 PM Alexandre Courbot <acourbot@...dia.com> wrote:
>>
>> +        if ALIGN.is_power_of_two() {
>> +            // INVARIANT: `align` is a power of two.
>> +            // SAFETY: `align` is a power of two, and thus non-zero.
>> +            Self(unsafe { NonZero::new_unchecked(ALIGN) })
>> +        } else {
>> +            build_error!("Provided alignment is not a power of two.");
>> +        }
>
> Would `build_assert!` at the top work instead?

Oops, it certainly would.

>
>> +    /// Returns this alignment as a `usize`.
>
> Intra-doc link.
>
>> +            // SAFETY: per the invariants, `self.0` is always a power of two so this block will
>
> "Per".
>
> I can pick this, with or without the user -- or do you need this in
> Nova this cycle?

With -rc6 approaching, I don't think we will merge any Nova code taking
advantage of this for this cycle, so please feel free to take this
patch. We can then merge patch 2 through drm-rust after -rc1 is
released.

Should I send a new revision with your fixes, or will you apply them?