From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 33927CD6E57 for ; Wed, 3 Jun 2026 01:28:00 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 7DC24113BC1; Wed, 3 Jun 2026 01:27:59 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.b="j/Z8eUVs"; dkim-atps=neutral Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by gabe.freedesktop.org (Postfix) with ESMTPS id 1C950113BC0 for ; Wed, 3 Jun 2026 01:27:59 +0000 (UTC) Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id 41B37601E7; Wed, 3 Jun 2026 01:27:58 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 362E71F00893; Wed, 3 Jun 2026 01:27:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1780450077; bh=mDJGqICcZVxPtHlEwcDyvQr28S8ONtlLg4MREDp243s=; h=From:To:Cc:Subject:Date; b=j/Z8eUVsPRErshGfU43zK+45aN6/CeddZPC5D9inLoGX4zmR6VlQMgq/TsytMmUQn uSkRFZ9gCM3cjnUeulqgxn3IV3Iqz1hrJvscGXMuiZLfOBu0N1bcYZ5rnJQza5v5nN w4zW97d/luSl/ZYGli5pmT8vCBykHdv+gqo2VQiH43b9PlUDiiCffjRgCIGt+vOaNA GW4EzPNWUb9paCPvsDb9Hx0/nJBfwKqAC/boKMufhC7dthst81UFDVtXd3jQGalSSi 2zjGKzA1NCbs5FCwiWyhs6/+BxgpXrVWYyOiGGynm9o3WE0KhepauLO6mHceZDFwk+ 12mceVkpCoaDg== From: Danilo Krummrich To: dakr@kernel.org, aliceryhl@google.com, daniel.almeida@collabora.com, acourbot@nvidia.com, ecourtney@nvidia.com, ojeda@kernel.org, boqun@kernel.org, gary@garyguo.net, bjorn3_gh@protonmail.com, lossin@kernel.org, a.hindborg@kernel.org, tmgross@umich.edu, deborah.brouwer@collabora.com, boris.brezillon@collabora.com Cc: driver-core@lists.linux.dev, linux-kernel@vger.kernel.org, nova-gpu@lists.linux.dev, dri-devel@lists.freedesktop.org, rust-for-linux@vger.kernel.org Subject: [PATCH v2 0/7] rust: drm: Higher-Ranked Lifetime private data Date: Wed, 3 Jun 2026 03:15:42 +0200 Message-ID: <20260603011711.2077361-1-dakr@kernel.org> X-Mailer: git-send-email 2.54.0 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" DRM ioctls run in process context without any guarantee that the parent bus device is still bound. This series solves the problem by introducing UnbindGuard -- a guard representing a drm_dev_enter/exit SRCU critical section that proves the parent bus device is bound for the lifetime of the guard. On top of that, add RegistrationData as a ForLt associated type on drm::Driver, allowing drivers to store data whose lifetime is tied to the parent bus device binding scope. The data is allocated in Registration::new(), lifetime-erased to 'static for storage, and made accessible through UnbindGuard::registration_data_with(). The closure's HRTB ties the lifetime to the closure scope, and ForLt::cast_ref_unchecked shortens it from 'static internally. The reference is valid for the duration of the drm_dev_enter/exit critical section held by UnbindGuard. Also update the ioctl dispatch macro to wrap every handler in an UnbindGuard, returning ENODEV if the device has been unplugged, and pass both the bound parent bus device and the registration data as arguments to handlers. This series is based on [1]; a branch with all patches can be found in [2]. [1] https://lore.kernel.org/driver-core/20260603011020.2073650-1-dakr@kernel.org/ [2] https://git.kernel.org/pub/scm/linux/kernel/git/dakr/linux.git/log/?h=drm-lifetime Changes in v2: - Replace unsafe direct registration data access in ioctl dispatch with safe UnbindGuard::registration_data_with() closure - Eliminate unbind_guard() free function; use type-inference anchor to enable direct dev.unbind_guard() method call in the ioctl macro - UnbindGuard::registration_data_with() provides both parent device and registration data to the closure - Add nova-drm conversion patch demonstrating lifetime-aware registration data with &'bound auxiliary::Device - Various safety comment and documentation improvements Danilo Krummrich (7): rust: drm: Add Driver::ParentDevice associated type rust: drm: Add UnbindGuard for drm_dev_enter/exit critical sections rust: drm: Add RegistrationData to drm::Driver rust: drm: Wrap ioctl dispatch in UnbindGuard rust: drm: Pass bound parent device to ioctl handlers rust: drm: Pass registration data to ioctl handlers drm: nova: convert to use DRM registration data drivers/gpu/drm/nova/driver.rs | 38 +++++---- drivers/gpu/drm/nova/file.rs | 21 +++-- drivers/gpu/drm/tyr/driver.rs | 22 ++++-- drivers/gpu/drm/tyr/file.rs | 4 + rust/kernel/drm/device.rs | 138 ++++++++++++++++++++++++++++++++- rust/kernel/drm/driver.rs | 134 ++++++++++++++++++++++++-------- rust/kernel/drm/ioctl.rs | 33 +++++++- rust/kernel/drm/mod.rs | 1 + 8 files changed, 325 insertions(+), 66 deletions(-) base-commit: e3b6e4c944a174277729dced5ab4ad5c0e53ff92 -- 2.54.0