linux-kernel - Re: [PATCH v2 0/2] Add Opaque::cast

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: <aFrJW31m8anUpnJ2@Mac.home>
Date: Tue, 24 Jun 2025 08:50:51 -0700
From: Boqun Feng <boqun.feng@...il.com>
To: Alice Ryhl <aliceryhl@...gle.com>
Cc: Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>,
	Maxime Ripard <mripard@...nel.org>,
	Thomas Zimmermann <tzimmermann@...e.de>,
	David Airlie <airlied@...il.com>, Simona Vetter <simona@...ll.ch>,
	Miguel Ojeda <ojeda@...nel.org>, Danilo Krummrich <dakr@...nel.org>,
	Gary Guo <gary@...yguo.net>,
	Björn Roy Baron <bjorn3_gh@...tonmail.com>,
	Benno Lossin <lossin@...nel.org>,
	Andreas Hindborg <a.hindborg@...nel.org>,
	Trevor Gross <tmgross@...ch.edu>, dri-devel@...ts.freedesktop.org,
	rust-for-linux@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 0/2] Add Opaque::cast_from

On Tue, Jun 24, 2025 at 03:27:54PM +0000, Alice Ryhl wrote:
> Since commit b20fbbc08a36 ("rust: check type of `$ptr` in
> `container_of!`") we have enforced that the field pointer passed to
> container_of! must match the declared field. This caused mismatches when
> using a pointer to bindings::x for fields of type Opaque<bindings::x>.
> 
> This situation encourages the user to simply pass field.cast() to the
> container_of! macro, but this is not great because you might
> accidentally pass a *mut bindings::y when the field type is
> Opaque<bindings::x>, which would be wrong.
> 
> To help catch this kind of mistake, add a new Opaque::cast_from that
> wraps a raw pointer in Opaque without changing the inner type. Also
> rename raw_get() to cast_into() for naming consistency.
> 
> Signed-off-by: Alice Ryhl <aliceryhl@...gle.com>

Acked-by: Boqun Feng <boqun.feng@...il.com>

Thanks!

Regards,
Boqun