linux-kernel - Re: [PATCH v10 1/5] rust: types: Add Ownable/Owned types

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: <877c18849m.fsf@kernel.org>
Date: Thu, 19 Jun 2025 11:33:25 +0200
From: Andreas Hindborg <a.hindborg@...nel.org>
To: "Benno Lossin" <lossin@...nel.org>
Cc: "Oliver Mangold" <oliver.mangold@...me>,  "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" <benno.lossin@...ton.me>,
  "Alice Ryhl" <aliceryhl@...gle.com>,  "Trevor Gross" <tmgross@...ch.edu>,
  "Asahi Lina" <lina@...hilina.net>,  <rust-for-linux@...r.kernel.org>,
  <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v10 1/5] rust: types: Add Ownable/Owned types

"Benno Lossin" <lossin@...nel.org> writes:

> On Wed Jun 18, 2025 at 11:34 AM CEST, Oliver Mangold wrote:
>> On 250514 1132, Benno Lossin wrote:
>>> On Fri May 2, 2025 at 11:02 AM CEST, Oliver Mangold wrote:
>>>
>>> > +/// - That the C code follows the usual mutable reference requirements. That is, the kernel will
>>> > +///   never mutate the [`Ownable`] (excluding internal mutability that follows the usual rules)
>>> > +///   while Rust owns it.
>>>
>>> I feel like this requirement is better put on the `Owned::from_raw`
>>> function.
>>
>> Thinking about it some more, the problem I see here is that if the type
>> implements `OwnableMut` this requirement changes from "never mutate" to
>> "never access at all".
>>
>> The safety requirements between `Ownable`, `OwnableMut`, `RefCounted`,
>> `OwnableRefCounted` and `AlwaysRefCounted` are interacting, but I agree
>> that, when looking at it a certain way, `Owned::from_raw()` is the place
>> where one would expect these to be. I'm not sure anymore what is best here
>> :/
>
> I still think `Owned::from_raw` is the correct place to put this.
>
>>
>>> > +pub unsafe trait OwnableMut: Ownable {}
>>>
>>> I don't like the name, but at the same time I also have no good
>>> suggestion :( I'll think some more about it.
>>
>> There was already a bit of discussion about it. I had my own implementation of this
>> where I used the names `UniqueRefCounted` and `UniqueRef`, but after discovering
>> this version from Asahi Lina, I took it as it was, keeping the name.
>>
>> No one else came up with different suggestions so far, so maybe we should just leave it
>> at `Owned`/`Ownable`?
>
> I'm just hung up on the `Mut` part... Haven't come up with a good
> replacement yet.

What do you dislike about the xxxxMut pattern?


Best regards,
Andreas Hindborg