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 <20230127140319.22af6060.gary@garyguo.net>
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From:   Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
Date:   Fri, 27 Jan 2023 15:11:32 +0100
Message-ID: <CANiq72kXNvQ-GY-uw24s_1NmQ5G12Cu+JfYKFQ0rC-4Fnm8o8Q@mail.gmail.com>
Subject: Re: [PATCH 4/5] rust: types: implement `ForeignOwnable` for the unit type
To:     Gary Guo <gary@garyguo.net>
Cc:     Wedson Almeida Filho <wedsonaf@gmail.com>,
        rust-for-linux@vger.kernel.org, Miguel Ojeda <ojeda@kernel.org>,
        Alex Gaynor <alex.gaynor@gmail.com>,
        Boqun Feng <boqun.feng@gmail.com>,
        =?UTF-8?Q?Bj=C3=B6rn_Roy_Baron?= <bjorn3_gh@protonmail.com>,
        linux-kernel@vger.kernel.org
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On Fri, Jan 27, 2023 at 3:03 PM Gary Guo <gary@garyguo.net> wrote:
>
> this should really be `core::ptr::invalid(1)`. That's currently
> unstable, but can be equivalently written as
> `NonNull::<()>::dangling().as_ptr()`.
>
> This has a different semantic meaning from `as` since it explicitly
> suggests an invalid provenance and thus will not alias with other
> pointers. (Although I don't think compiler currently can take advantage
> of this fact yet)

We talked about starting to use `strict_provenance` when it came out
-- what is the latest status? i.e. do you know if it is expected that
it will pass FCP etc.? (my understanding originally was that it was an
experiment).

If it is likely to become stable, then I agree it could be nice to
start using it before a lot of kernel code gets written without it.

Thanks Gary!

Cheers,
Miguel