From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794018029; b=gVkpShadBmjG3Pb7SM5ihQgCqjwr856oaZN2Hkw8lnzL4bu0ZNYo5QXVxKmaxVmTxkiP ALGsdaCgNnbXYP3jlOSBNBN0ZD0hqEscGIXKRfHhbnKMyaU+NXjpOM8lDzkZlT8amM5rK f8lIX4dhmTVEzNpUIqqsS03s7AH7da0MTi62kNNNw2A/HKw/LTwdopE2aNrpjJn9Y1M+w p6jJrEVTKMepeSrTu4vprXI661YxuNFjWsfgJsYo56Nsge4dldc7L4M9YN8Z+qUAhHKFa HjL3u9W5KewMkefyFf8ULs12XlEMnbKE3Z4JH4V3/CcgEKei67CKwN3rGekdaDh83AQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794018029; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:Content-Transfer-Encoding; bh=GQNExV2IBW/VIXiP+QKPq05xQXuih8H7xGZygNB42ds=; b=RVf9ExtUVFV4JRnTiMjyRKeUi5ezzwagiqO6CJ+qBwdNlW13cXuwcnrgqKt2UbItUyn0 ZS2M7y01qwUXCEP6IuUhxysuQHet23m3lLbl7TXvAxa5EvpjHuoNQhejzOh0Om8GcFU02 gZzJmaxDeaOXtVx6G0sxtL3YWnxxoIGHlURJZUMV8efA+v45FqT3K/zc/nLRFJIBChXiq aLNe96B+nn2BvmTPjVLzuv5vUEb6OhJIC5TCfAb1C0iXqnPCiJAz6pZ+Z11rcj7fF8Ct6 4DBSX9O67KgE6FvEhPApiPttVxnYwZDruUxxpohNjQFEVrmGEzRe3FN5EWNcy0qnspg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=VZG1LcMF; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 93100606A326; Sat, 7 Nov 2026 02:20:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=VZG1LcMF Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7C4DD1F008A3; Sat, 7 Nov 2026 02:20:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794018029; bh=GQNExV2IBW/VIXiP+QKPq05xQXuih8H7xGZygNB42ds=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=VZG1LcMFLK+j+r6SEp67HSNoHe81odWNIkDi9DME3e9tBooSE5IWxcPaslSi8HqUH C84gS9G+hliw3eWpKdf25eor+MavBp1HQsBs38+02DpLYRyIDiszJSRMJcS5sFB+oq 7frnYU+TUngxm6yrZeRftEYxlfd17zIKUH2fO1U5EeEn3xQ6YddOC4s/6ruoddjOz/ QcDCSJczb1iUmHrKi95X1Pn3Kd4s4KkkXJO2V1hUkG4jHskRhrOGJTatlFUtNTpTMH iJv2SfkEsVXTSMr9TcfVoYEOLslAzIafhFltAhfZ2O4oAaSsvTmr014KeFh+Dp3ii+ m8M39LkGSGnnA== 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 v2 2/7] rust: drm: gem: gate open/close callbacks with RegistrationGuard Date: Sat, 7 Nov 2026 03:03:20 +0100 Message-ID: <20261107021427.2105374-3-dakr@kernel.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261107021427.2105374-1-dakr@kernel.org> References: <20261107021427.2105374-1-dakr@kernel.org> X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list 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. Reviewed-by: Alice Ryhl Reviewed-by: Daniel Almeida 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 85657a39e146..94355081edab 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) }; -- 2.56.0