From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from sender4-pp-f112.zoho.com (sender4-pp-f112.zoho.com [136.143.188.112]) (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 A1A6128C2B5 for ; Fri, 20 Jun 2025 13:42:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=pass smtp.client-ip=136.143.188.112 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750426979; cv=pass; b=RfFU7VnJrhJRFKTBpCMu84HadmghQEiqKUDBAE8kqd1ot2FZz/C+YOhd/wUU3zf1iVSN/X1wo+SIZpAbgGPT/taVK5B+DAz5PqTHVKa3qQ0/LFACJWT+17qqFlQJHnHjGr0PMM1ahaos4uVglzL8BIaqOJXdcGgf27ilBfLFBp0= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750426979; c=relaxed/simple; bh=mDliNZjN0LQ2oSXKvbbYIgIMGFlBC+bFTX0MfjIcjuw=; h=Content-Type:Mime-Version:Subject:From:In-Reply-To:Date:Cc: Message-Id:References:To; b=QWdhEQAXjV+aHQuTc8rjHycpUzlMXdFjhLQLGpjflLCixJ+46NSTV+UKdGIlXk6Y8m7X8Zlhsz9Ey5HFWbPJdGpANwFG7VEjXBQUkGTWl26plE7EpKkGZxevBHUjMgWBb5DInLqOPUf24nx91veNnAEgNYo3WYxr/g/pNFFKsOw= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=collabora.com; spf=pass smtp.mailfrom=collabora.com; dkim=pass (1024-bit key) header.d=collabora.com header.i=daniel.almeida@collabora.com header.b=M5/miJYU; arc=pass smtp.client-ip=136.143.188.112 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=collabora.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=collabora.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=collabora.com header.i=daniel.almeida@collabora.com header.b="M5/miJYU" ARC-Seal: i=1; a=rsa-sha256; t=1750426948; cv=none; d=zohomail.com; s=zohoarc; b=f6hoq1KduJGVvC3tyfXlC3vS2PCHfT2tbNKQZ0coR9uNefZ4X7e906afL9MOKyP7WL3pLQee/9IsUMtGiuP05Fvca51CZBsOETJTUtLgYOW8D4m3yivT+Q8LLimn7+ELg5u3Qpuhg3nf4mHT0g41aEHRnKWgC4Ny5T4P7eW7JBk= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1750426948; h=Content-Type:Content-Transfer-Encoding:Cc:Cc:Date:Date:From:From:In-Reply-To:MIME-Version:Message-ID:References:Subject:Subject:To:To:Message-Id:Reply-To; bh=KDCFKsKcyeIIzEy/lqv2lQlFj4SyqbS6lavMWO1IBd0=; b=ZB504/Apa6uh3pv2Bg4NTJ1nHut6ni3mA9KZc2r1op0XAr/x8NQyY5tm8Sqs5XTrsq4DiVY5Y7fB8ucO55aWOG4CKfp6gvIh9A2N5z75EQ+reNmKpgmXEBsYmG/hTl/vGupECMZpr994SjacRH/4ueqZyigjcjcHblyfUWeQhTc= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass header.i=collabora.com; spf=pass smtp.mailfrom=daniel.almeida@collabora.com; dmarc=pass header.from= DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; t=1750426948; s=zohomail; d=collabora.com; i=daniel.almeida@collabora.com; h=Content-Type:Mime-Version:Subject:Subject:From:From:In-Reply-To:Date:Date:Cc:Cc:Content-Transfer-Encoding:Message-Id:Message-Id:References:To:To:Reply-To; bh=KDCFKsKcyeIIzEy/lqv2lQlFj4SyqbS6lavMWO1IBd0=; b=M5/miJYUM5spp67kkinurcfxJEEF7xkfvZcUNQK9/pA8LcHul26TIWxTDjmynfRV KbGVF6uapnuP0fOsQO+XPG1qdI9cz44FtH1KYYDnlp2C8mii3WuykKOjn/ZK1jouSy1 vxoaqDGDYFCaAgcLxqeVH+rQ0lJ+3atoCuaJ3aHQ= Received: by mx.zohomail.com with SMTPS id 1750426945400308.2619948150958; Fri, 20 Jun 2025 06:42:25 -0700 (PDT) Content-Type: text/plain; charset=utf-8 Precedence: bulk X-Mailing-List: rust-for-linux@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 (Mac OS X Mail 16.0 \(3826.600.51.1.1\)) Subject: Re: [PATCH] rust: drm: Drop the use of Opaque for ioctl arguments From: Daniel Almeida In-Reply-To: Date: Fri, 20 Jun 2025 10:42:09 -0300 Cc: Benno Lossin , Danilo Krummrich , ojeda@kernel.org, alex.gaynor@gmail.com, aliceryhl@google.com, boqun.feng@gmail.com, gary@garyguo.net, bjorn3_gh@protonmail.com, a.hindborg@kernel.org, tmgross@umich.edu, alyssa@rosenzweig.io, lyude@redhat.com, rust-for-linux@vger.kernel.org, dri-devel@lists.freedesktop.org Content-Transfer-Encoding: quoted-printable Message-Id: <49BDC70A-7CBF-4C2F-955F-B680DA0BF30C@collabora.com> References: <20250619102102.750668-1-beata.michalska@arm.com> <6DB37626-8817-4939-AE8E-6A463186A550@collabora.com> To: Beata Michalska X-Mailer: Apple Mail (2.3826.600.51.1.1) X-ZohoMailClient: External Hi Beata, > There is no concurrent access nor shared references, unless the > handler decides otherwise It can=E2=80=99t do so in safe code. There is no way to manufacture a = shared reference from a mutable one in safe code and if it passes that to C, = then it=E2=80=99s already using a unsafe block for the ffi call. Unless I missed something? =E2=80=94 Daniel=