From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 5D7CB34252B; Fri, 14 Aug 2026 23:09:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786748981; cv=none; b=VA1NWLX3J37eNvm2kC6nOEfGDlWYXMBn1S/zpvmYc6XhCKIcZt44pFTHAgtzs+HsT3zd7J5qHRNuWr+799ZIyeHBFiR7RO1mPJ7SPEzNLgbjco/fwOD+YsBHx3k/Afu8FGJfkHId7HVe2R+zx+r1PtjZVpAZdty+stOOM/8wFSo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786748981; c=relaxed/simple; bh=G/1K1XMVr5yKDUV9iauQ7JNQt7DvZnhVUGWQIKfu9YI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=eNhcFP4WQenGZV68kQGh0WLzAcR6LCIL2DO7DYQH/CqwB1+E9unWEjLbfrsKJsDXq3X/EwGWiJGr1RUXNnE52eyRvpMT5ZdNZeWMPa+qHVgzKAUkOiFshTvmPKzovAtN/OyptERnl99qvXq47f/7dVwuE3TcdyuziGfCyMDCJVI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=f25gp82M; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="f25gp82M" Received: by smtp.kernel.org (Postfix) with ESMTPSA id BB8D01F00A3D; Fri, 14 Aug 2026 23:09:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1786748980; bh=sSKhhle7EcwGqQ4E8Sm0jDW4kZ+Q2qKC0uMRA8YVy+o=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=f25gp82M8K21LocoUm752Joix3iCnsavD6WDN+D9Ll7CTeAOL1aTTXNaJM7W+PYwP +2frfr1gC9oRe+tAkPppYQiwqgp72ZGN7AeW3bCzsEIlV/NJ1bc0PnvB20VbST+6XM DwAcUwGcDGjZKOaDyE/mi4l0OTBNaagsj0v+50bFrP5HYTlFvjoxlDg9DFZukkGyyU 8ObKe+ZdvsoydxwN2myzb4nRGXMjY9aCg/oBQrKWLblo5NTGjTYKHWkBlGIJ47BmHW LWoRcIkSIPoc57ksW6R6fGMD7FI0LcxWUgM9f1WbATTnLjZkx3cF+z3QAJw8tM9RVf REb7T99DaGeuw== From: Danilo Krummrich To: dakr@kernel.org, aliceryhl@google.com, acourbot@nvidia.com, daniel.almeida@collabora.com, ojeda@kernel.org, boqun@kernel.org, gary@garyguo.net, bjorn3_gh@protonmail.com, lossin@kernel.org, a.hindborg@kernel.org, tmgross@umich.edu, tamird@kernel.org, work@onurozkan.dev, brauner@kernel.org, lyude@redhat.com, j@jananu.net, alvin.sun@linux.dev, deborah.brouwer@collabora.com, laura.nao@collabora.com, beata.michalska@arm.com Cc: nova-gpu@lists.linux.dev, dri-devel@lists.freedesktop.org, rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 2/7] rust: drm: gem: gate open/close callbacks with RegistrationGuard Date: Sat, 15 Aug 2026 01:09:00 +0200 Message-ID: <20260814230923.1292966-3-dakr@kernel.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260814230923.1292966-1-dakr@kernel.org> References: <20260814230923.1292966-1-dakr@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Wrap the GEM object open and close callbacks with a RegistrationGuard (drm_dev_enter / drm_dev_exit) to ensure the driver callbacks only run while the parent bus device is bound. If the device has been unbound, open returns -ENODEV and close silently returns. This prevents driver code from accessing device resources after unbind and is a prerequisite for making drm::Driver::File lifetime-parameterized, since GEM callbacks receive a &drm::File that could otherwise be used to access invalidated file private data. Signed-off-by: Danilo Krummrich --- rust/kernel/drm/gem/mod.rs | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/rust/kernel/drm/gem/mod.rs b/rust/kernel/drm/gem/mod.rs index 80d8f524f9d5..560403ca8e38 100644 --- a/rust/kernel/drm/gem/mod.rs +++ b/rust/kernel/drm/gem/mod.rs @@ -128,6 +128,14 @@ extern "C" fn open_callback( raw_obj: *mut bindings::drm_gem_object, raw_file: *mut bindings::drm_file, ) -> core::ffi::c_int { + // SAFETY: `raw_obj` is a valid pointer to a `struct drm_gem_object` with a valid `dev`. + let dev: &drm::Device = + unsafe { drm::Device::from_raw((*raw_obj).dev) }; + + let Some(_guard) = dev.registration_guard() else { + return ENODEV.to_errno(); + }; + // SAFETY: `open_callback` is only ever called with a valid pointer to a `struct drm_file`. let file = unsafe { DriverFile::::from_raw(raw_file) }; @@ -148,6 +156,14 @@ extern "C" fn close_callback( raw_obj: *mut bindings::drm_gem_object, raw_file: *mut bindings::drm_file, ) { + // SAFETY: `raw_obj` is a valid pointer to a `struct drm_gem_object` with a valid `dev`. + let dev: &drm::Device = + unsafe { drm::Device::from_raw((*raw_obj).dev) }; + + let Some(_guard) = dev.registration_guard() else { + return; + }; + // SAFETY: `open_callback` is only ever called with a valid pointer to a `struct drm_file`. let file = unsafe { DriverFile::::from_raw(raw_file) }; -- 2.55.0