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smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=NCP68KFo; 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="NCP68KFo" Received: by smtp.kernel.org (Postfix) with ESMTPSA id DB7ECC4CED1; Thu, 5 Dec 2024 08:41:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1733388066; bh=WYpbDWRtvOOHP+CzCeri9xxwbKUUtMqW3Q/EKdGc6xc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=NCP68KFoAZzpghFtITq6Gd8lUmfrY+TdR5YugXOjvNXMPhjEwStMTHeFM3hrSovLf y4bWNc3L4Il3BbBH0SLLgQ4gL4uvQDajfYCNdRPAxl4BoaScWSVmtaxm6XTmDB5GZk /8hgtsixQEoWknOYMrF4/8WGYXf36fzVfeVgrwyZTCc7wDLjkoLu39CcELNH5FpBnw uyuqWFBVtT5etU8UlB4F4+Cg5rGP2EqoNsY1ciNcxiSUZTzBbR5TzQtPeYZykTd2sV V4FFQxE+duk+gpo17bJ0oXO+7MpzsffLApceWDRpMWLTNnIBBkN2Wv/ve8+XcMLQre euQHiMMlx1nrw== Date: Thu, 5 Dec 2024 08:41:01 +0000 From: Lee Jones To: Greg KH Cc: linux-kernel@vger.kernel.org, ojeda@kernel.org, alex.gaynor@gmail.com, boqun.feng@gmail.com, gary@garyguo.net, bjorn3_gh@protonmail.com, benno.lossin@proton.me, a.hindborg@kernel.org, aliceryhl@google.com, tmgross@umich.edu, rust-for-linux@vger.kernel.org Subject: Re: [PATCH 1/2] samples: rust: Provide example using the new Rust MiscDevice abstraction Message-ID: <20241205084101.GE7451@google.com> References: <20241204174627.1151288-1-lee@kernel.org> <2024120427-scurvy-fidgety-06fc@gregkh> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <2024120427-scurvy-fidgety-06fc@gregkh> On Wed, 04 Dec 2024, Greg KH wrote: > On Wed, Dec 04, 2024 at 05:46:24PM +0000, Lee Jones wrote: > > This sample driver demonstrates the following basic operations: > > > > * Register a Misc Device > > * Create /dev/rust-misc-device > > * Open the aforementioned character device > > * Operate on the character device via a simple ioctl() > > * Close the character device > > > > Signed-off-by: Lee Jones > > --- > > samples/rust/Kconfig | 10 ++++ > > samples/rust/Makefile | 1 + > > samples/rust/rust_misc_device.rs | 84 ++++++++++++++++++++++++++++++++ > > 3 files changed, 95 insertions(+) > > create mode 100644 samples/rust/rust_misc_device.rs > > > > diff --git a/samples/rust/Kconfig b/samples/rust/Kconfig > > index b0f74a81c8f9..df384e679901 100644 > > --- a/samples/rust/Kconfig > > +++ b/samples/rust/Kconfig > > @@ -20,6 +20,16 @@ config SAMPLE_RUST_MINIMAL > > > > If unsure, say N. > > > > +config SAMPLE_RUST_MISC_DEVICE > > + tristate "Misc device" > > + help > > + This option builds the Rust misc device. > > + > > + To compile this as a module, choose M here: > > + the module will be called rust_misc_device. > > + > > + If unsure, say N. > > + > > config SAMPLE_RUST_PRINT > > tristate "Printing macros" > > help > > diff --git a/samples/rust/Makefile b/samples/rust/Makefile > > index c1a5c1655395..ad4b97a98580 100644 > > --- a/samples/rust/Makefile > > +++ b/samples/rust/Makefile > > @@ -2,6 +2,7 @@ > > ccflags-y += -I$(src) # needed for trace events > > > > obj-$(CONFIG_SAMPLE_RUST_MINIMAL) += rust_minimal.o > > +obj-$(CONFIG_SAMPLE_RUST_MISC_DEVICE) += rust_misc_device.o > > obj-$(CONFIG_SAMPLE_RUST_PRINT) += rust_print.o > > > > rust_print-y := rust_print_main.o rust_print_events.o > > diff --git a/samples/rust/rust_misc_device.rs b/samples/rust/rust_misc_device.rs > > new file mode 100644 > > index 000000000000..5f1b69569ef7 > > --- /dev/null > > +++ b/samples/rust/rust_misc_device.rs > > @@ -0,0 +1,84 @@ > > +// SPDX-License-Identifier: GPL-2.0 > > Nit, you forgot a copyright line here :) I can add one, but none of the other drivers in this directory has one. >> > + > > +//! Rust misc device sample. > > + > > +use kernel::{ > > + c_str, > > + ioctl::_IO, > > + miscdevice::{MiscDevice, MiscDeviceOptions, MiscDeviceRegistration}, > > + prelude::*, > > +}; > > + > > +const RUST_MISC_DEV_HELLO: u32 = _IO('R' as u32, 9); > > + > > +module! { > > + type: RustMiscDeviceModule, > > + name: "rust_misc_device", > > + author: "Lee Jones", > > + description: "Rust misc device sample", > > + license: "GPL", > > +} > > + > > +struct RustMiscDeviceModule { > > + _miscdev: Pin>>, > > +} > > + > > +impl kernel::Module for RustMiscDeviceModule { > > + fn init(_module: &'static ThisModule) -> Result { > > + pr_info!("Initialising Rust Misc Device Sample\n"); > > + > > + let options = MiscDeviceOptions { > > + name: c_str!("rust-misc-device"), > > + }; > > + > > + Ok(Self { > > + _miscdev: KBox::pin_init( > > + MiscDeviceRegistration::::register(options), > > + GFP_KERNEL, > > + )?, > > + }) > > + } > > +} > > + > > +struct RustMiscDevice; > > + > > +impl RustMiscDevice { > > + fn new() -> Self { > > + Self > > + } > > +} > > + > > +#[vtable] > > +impl MiscDevice for RustMiscDevice { > > + type Ptr = KBox; > > + > > + fn open() -> Result> { > > + pr_info!("Opening Rust Misc Device Sample\n"); > > + > > + Ok(KBox::new(RustMiscDevice::new(), GFP_KERNEL)?) > > + } > > + > > + fn ioctl( > > + _device: ::Borrowed<'_>, > > + cmd: u32, > > + _arg: usize, > > + ) -> Result { > > + pr_info!("IOCTLing Rust Misc Device Sample\n"); > > + > > + match cmd { > > + RUST_MISC_DEV_HELLO => pr_info!("Hello from the Rust Misc Device\n"), > > + _ => { > > + pr_err!("IOCTL not recognised: {}\n", cmd); > > + return Err(EINVAL); > > + } > > + } > > + > > + Ok(0) > > + } > > +} > > + > > +impl Drop for RustMiscDevice { > > + fn drop(&mut self) { > > + pr_info!("Exiting the Rust Misc Device Sample\n"); > > + } > > Cool! But no read/write functionality? :) Happy to add it subsequently. > Anyway, other than the copyright, this looks good to me. > > Although we should get the "validate the data" rust patch set in here > soon, so we don't have to go and fix up all users of the miscdev rust > api at once. Maybe I'll dig that series up over the holiday break if > someone doesn't beat me to it. What needs doing? Do you have a link? -- Lee Jones [李琼斯]