linux-kernel - Re: [PATCH] poll: rust: allow poll

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: <DARD1ZC0W9QR.3CBLX6RYE65VU@kernel.org>
Date: Fri, 20 Jun 2025 14:31:22 +0200
From: "Benno Lossin" <lossin@...nel.org>
To: "Alice Ryhl" <aliceryhl@...gle.com>, "Alexander Viro"
 <viro@...iv.linux.org.uk>, "Jan Kara" <jack@...e.cz>, "Miguel Ojeda"
 <ojeda@...nel.org>, "Christian Brauner" <brauner@...nel.org>
Cc: "Boqun Feng" <boqun.feng@...il.com>, "Gary Guo" <gary@...yguo.net>,
 Björn Roy Baron <bjorn3_gh@...tonmail.com>, "Andreas
 Hindborg" <a.hindborg@...nel.org>, "Trevor Gross" <tmgross@...ch.edu>,
 "Danilo Krummrich" <dakr@...nel.org>, <linux-kernel@...r.kernel.org>,
 <rust-for-linux@...r.kernel.org>
Subject: Re: [PATCH] poll: rust: allow poll_table ptrs to be null

On Fri Jun 20, 2025 at 1:49 PM CEST, Alice Ryhl wrote:
>      ///
>      /// # Safety
>      ///
> -    /// The caller must ensure that for the duration of `'a`, the pointer will point at a valid poll
> -    /// table (as defined in the type invariants).
> -    ///
> -    /// The caller must also ensure that the `poll_table` is only accessed via the returned
> -    /// reference for the duration of `'a`.
> -    pub unsafe fn from_ptr<'a>(ptr: *mut bindings::poll_table) -> &'a mut PollTable {

Returning `Option<&'a mut PollTable>` is not an option? I'd like to
avoid wrapping raw pointers...

---
Cheers,
Benno

> -        // SAFETY: The safety requirements guarantee the validity of the dereference, while the
> -        // `PollTable` type being transparent makes the cast ok.
> -        unsafe { &mut *ptr.cast() }
> -    }