From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5A60C274B39; Tue, 24 Jun 2025 15:35:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750779358; cv=none; b=rJFTiVr+C4qGnidB1q7YH7EgkuIRw7XklX1ClKSPfyVGQYHX1XCbToPkzRxPKvyA0XE/LrggY4gSl9mgpeeiolE/hBf5I9yDB+TACM8pqBFBCy1pv0LcSrAOoD78/x+KQ9Nn6DMz92JMrtgnTnAOqPuxhhaiH73DVbJsbRGXoVM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750779358; c=relaxed/simple; bh=DRqR9Ha0k6DhcalVMjKRWy3O1Lm+9xUHZDW7jOei0Fo=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=u8h5bXaMQt6ydrbJD+gEgRd8DKGPcqOvFEfuP6gtv8McRuI+U9EHG6P8+B60WmM/hTEb6h3NS7974AGuLmLnrbvZ6UjWfDz6U+8y8UPuYiGYyyldQ/WdDE9L+fJYJd99sM87ruTA2E4LZbtE9jixRYllAWmACAXRe4HQNMn8kxk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ofeVI+uj; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="ofeVI+uj" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E2217C4CEE3; Tue, 24 Jun 2025 15:35:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1750779357; bh=DRqR9Ha0k6DhcalVMjKRWy3O1Lm+9xUHZDW7jOei0Fo=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=ofeVI+uj2dSV/VDxHIE7DmfHk6a3Vn6RVzy/r4ULxwKxonRlyO3NmJCxyFD6c6Zmx SyqIL4swhkECFnBB95XAG9vzTnXKucT0gsBr4nnvEvdAl0dtSfQKNfAnGP2JcbEvOF texjyI5j7AWhj6/OZFvmLkufc7T4Am8Qw1VtyrgBYRNYOsL6rYX+7asBaA+H30lMUT PopeCbtGCfvA5FVgoOsH4/dm3Kb16riklga42G6svKkbsidGUwJYqIWbgJaMjw3ZMY s7ooUrPiI/yrL90yRbLosWJg1WYBYOQa6mOPKg23qXsMuLvZ03h38vDy04UfDAlPeY XunsuQR1DiNig== Message-ID: <9ccd25dc-d642-4fcd-8dbb-ae221fa97556@kernel.org> Date: Tue, 24 Jun 2025 17:35:52 +0200 Precedence: bulk X-Mailing-List: rust-for-linux@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 0/2] Add Opaque::cast_from To: Alice Ryhl Cc: Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , Miguel Ojeda , Boqun Feng , Gary Guo , =?UTF-8?Q?Bj=C3=B6rn_Roy_Baron?= , Benno Lossin , Andreas Hindborg , Trevor Gross , dri-devel@lists.freedesktop.org, rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org References: <20250624-opaque-from-raw-v2-0-e4da40bdc59c@google.com> From: Danilo Krummrich Content-Language: en-US In-Reply-To: <20250624-opaque-from-raw-v2-0-e4da40bdc59c@google.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 6/24/25 5:27 PM, 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. > > 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, 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. Reviewed-by: Danilo Krummrich