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 X-Spam-Level: X-Spam-Status: No, score=-17.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D99C6C07E96 for ; Sun, 4 Jul 2021 20:28:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B5F256115C for ; Sun, 4 Jul 2021 20:28:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229788AbhGDUbL (ORCPT ); Sun, 4 Jul 2021 16:31:11 -0400 Received: from mail.kernel.org ([198.145.29.99]:36468 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229549AbhGDUbL (ORCPT ); Sun, 4 Jul 2021 16:31:11 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id CAAC96115C; Sun, 4 Jul 2021 20:28:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1625430515; bh=n3LljfKpRHuXWIoIp69UEVTQbXFDjTbuAHNJvxk07Wg=; h=From:To:Cc:Subject:Date:From; b=GPrOrMpZjgWKYSUTHzSeDNf7KOU/lTI03+AS6tM1FBbx9oYbKlWHF28v46iVsWfKc bON3JJAKbU9nOuuYOr8T3tNGakmJ+jKONBX3/F8cDPAj7BjIdzIQRWavI+C19qckdX Fr0bDPDEdhoHxSrgPQFuRIBLC1SYms6cr4nHuqVW9MRzelrDTKRXnoiMGRnLEo3F3T wuT8ADtxvoFdIqUkA9Zvq6L8g0mN0aj70mZ2iCR6j+yWWB822XMgVHzroGTkjIBh0H zIePnyUhuyQZxqBj8PvRa7DrEIo5+5w0JuF3pggleB/flaU7naGi84jNFRfMs2moMK SlgC/2yL3xiOQ== From: ojeda@kernel.org To: Linus Torvalds , Greg Kroah-Hartman Cc: rust-for-linux@vger.kernel.org, linux-kbuild@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, Miguel Ojeda Subject: [PATCH 00/17] Rust support Date: Sun, 4 Jul 2021 22:27:39 +0200 Message-Id: <20210704202756.29107-1-ojeda@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: rust-for-linux@vger.kernel.org From: Miguel Ojeda Rust support This is the patch series to add support for Rust as a second language to the Linux kernel. If you are interested in following this effort, please join us in the mailing list at: rust-for-linux@vger.kernel.org and take a look at the project itself at: https://github.com/Rust-for-Linux Cheers, Miguel -- # Rust support This cover letter explains the major changes and updates done since the RFC sent in the previous merge window back in April, plus a few extra notes and announcements. For the RFC, please see: https://lore.kernel.org/lkml/20210414184604.23473-1-ojeda@kernel.org/ ## Rust infrastructure updates There have been several major improvements to the overall Rust support. The following subsections cover these. ### Removed panicking allocations We have removed infallible allocations. In order to do so, we have integrated a subset of the `alloc` standard library crate, with some additions on top. This allows us to customize things to our needs, while giving upstream the time they need to evaluate our changes. Eventually, the goal is to have everything the kernel needs in upstream `alloc` and drop it from the kernel tree. We have already started this process and some changes have been already accepted upstream. On top of that, `alloc` is now compiled with panicking allocation methods disabled, thus they cannot be used within the kernel by mistake either. Moreover, the documentation for this customized `alloc` crate (as well as for `core`) is now generated alongside the rest of the Rust kernel documentation. Thus kernel developers can now easily browse the subset that is available within the kernel. Like last time, you can take a look at a preview of the documentation at: https://rust-for-linux.github.io/docs/alloc/ Note that the `compiler_builtins` panicking intrinsics are still there, but those will be solved by partitioning `core` via feature gates. The first one, for disabling floating-point functionality, has just been accepted upstream. ### Beta compiler supported Up until now, we have been using nightly releases of `rustc` because we need some of the latest fixes and unstable features. However, the kernel can now be compiled with beta and stable `rustc` releases. At the moment, we are using the 1.54-beta1 version as our reference compiler. At the end of this month, `rustc` 1.54 will be released, and we will move to that version as our reference. Note that the kernel still requires unstable features, even if it is compiled with a stable `rustc` release, thus we cannot guarantee that future `rustc` versions will work without changes to the kernel tree. Thus, until all the unstable features we need are stabilized, we will support a single `rustc` version for each kernel release. ### Testing support Another big addition has been the support for testing. We now support the standard Rust `#[test]` attribute to easily write tests, e.g.: #[test] fn f() { let a = 20; let b = 22; assert_eq!(a + b, 42); } Furthermore, we are now also supporting Rust documentation tests ("doctests"). These allow us to make sure our examples remain up to date, and also double as tests too, e.g.: /// ``` /// assert_eq!(foo::f(), 42); /// ``` pub fn f() -> i32 { 42 } For the moment, both kinds of tests are run in the host only, but the goal is to have them running in kernel space, so that we can test code that depends on kernel features, and to allow any kernel module to declare and use them. ### Architectures and compiler support `arm` (i.e. 32-bit) and `riscv` are now also supported. On compilers, we would like to mention all the work that has been going in GCC Rust (a GCC frontend for the Rust language) and `rustc_codegen_gcc` (a `rustc` backend for GCC). The latter now passes all `core` tests, and the former is now working on traits. We continue to track their progress as they may become the best way to have GCC-built kernels with Rust support enabled. Their latest reports can be found at: https://blog.antoyo.xyz/rustc_codegen_gcc-progress-report-1 https://thephilbert.io/2021/06/28/gcc-rust-weekly-status-report-20/ On top of that, we requested Compiler Explorer to add support to all the alternative compilers. At the time of writing, they have already added `mrustc` and GCC Rust; and `rustc_codegen_gcc` is coming soon. See a live example at: https://godbolt.org/z/8o74c57Yj ## Rust abstractions and driver updates We have developed new Rust abstractions that use the kernel C implementations: red-black trees, reference-counted objects, file descriptor creation, tasks, files, io vectors... Additionally, we have improved driver support: improvements to `file_operations` (more operations supported, arbitrary state), reduced boiler-plate code, improved `module!` macro, registration macros, rudimentary (`probe` and `remove`) platform drivers... On Binder, there is now support for transferring files descriptors and LSM hooks; and we are working on preliminary performance numbers. Moreover, there is ongoing work on a Rust example driver, `bcm2835-rng`. This is the hardware random-number generator present on Raspberry Pi Zero(W), Classic, Two, and Three. There are other small improvements, such as drivers being restricted on what unstable features they can use. ## Patch series status Like it was mentioned in the RFC, the Rust support is still to be considered experimental. However, as noted back in April, support is good enough that kernel developers can start working on the Rust abstractions for subsystems and write drivers and other modules. Please note that the current series have just arrived in `linux-next`, thus the first run will happen on Tuesday. ## Industry and academia support We have been in contact with a set of companies and academia members that would like to use Rust as a second language in the kernel. Some of them have already started to evaluate Rust for their needs using the infrastructure we have already in place. In particular, we have got a few statements from major companies. In no particular order: Microsoft's Linux Systems Group is interested in contributing to getting Rust into Linux kernel. Hopefully we will be able to submit select Hyper-V drivers written in Rust in the coming months. Arm recognises the Rust value proposition and is actively working with the Rust community to improve Rust for Arm based systems. A good example is Arm’s RFC contribution to the Rust language which made Linux on 64-bit Arm systems a Tier-1 Rust supported platform. Rustaceans at Arm are excited about the Rust for Linux initiative and look forward to assisting in this effort. Google supports and contributes directly to the Rust for Linux project. Our Android team is evaluating a new Binder implementation and considering other drivers where Rust could be adopted. In addition, IBM contributed the Rust kernel support for PowerPC which was already included in the RFC. In addition, from academia, there are already several projects around Rust for Linux going on. As an example, members of LSE (Systems Research Laboratory) at EPITA (École pour l'informatique et les techniques avancées) are developing an SPI Rust driver. And, of course, special thanks go to ISRG (Internet Security Research Group) and Google for their financial support on this endeavor. ## Conferences and talks We have submitted talk proposals for LPC (Linux Plumbers Conference). The main one will describe the work we have done so far and ideally will also serve as an introduction for other kernel developers interested in using Rust in the kernel. It will cover an introduction of the language within the context of the kernel, how the overall Rust support works, how code is documented, how tests are written, a tour of available tooling, an explanation of coding guidelines, how kernel driver code looks like, etc. In addition, we would like to announce that we are organizing a new conference that focuses on Rust and the Linux kernel. The first edition will be virtual and will take place before LPC. Details will be announced soon. ## Acknowledgements The signatures in the main commits correspond to the people that wrote code that has ended up in them at the present time. For details on contributions to code and discussions, please see our repository: https://github.com/Rust-for-Linux/linux However, we would like to give credit to everyone that has contributed in one way or another to the Rust for Linux project. Since the RFC: - bjorn3 for all the input on Rust compiler details and all the reviews and suggestions. - Arthur Cohen, Esteban Blanc and Martin Schmidt for their ongoing work on the SPI abstractions and driver. - Dan Robertson for his ongoing work on softdeps in the `module!` macro and the addition of a few safety comments. - Paul Römer for his ongoing experiment on using `NonNull` as much as possible. - Sladyn Nunes for his ongoing sorting of error constants. - Jonathan Corbet and the LPC organizers for lending us the Linux Plumbers Conference infrastructure so that we can have an easy time setting up the new conference. - John Ericson for quickly implementing the `no_global_oom_handling` `cfg` feature in upstream `alloc` to easily disable all functionality that relies on panicking allocations. - Josh Triplett and John Ericson for their input on `alloc` which helped us decide what to do with it (i.e. fully custom vs. slightly custom in-tree copy vs. upstream), as well as offering to help moving forward some needed features on the Rust side. - Mark Rousskov for answering some questions about beta backports and scheduling, as well as working on unsticking `1.54.0-beta.1`. - Philipp Krones for his input on Clippy lints and discussing extensions for developing custom lints. - Antoni Boucher for his work on `rustc_codegen_gcc`. - Philip Herrons (and his supporters Open Source Security and Embecosm) for his work on GCC Rust. - Marc Poulhiès for his work on Compiler Explorer to add the alternative Rust compilers we requested. - Many folks that have reported issues, tested the project, helped spread the word, joined discussions and contributed in other ways! In no particular order: Chenguang Wang, Greg Morenz, John Baublitz, Leah Leshchinsky, Caedin Cook, Liam Arzola, Fabio Aiuto, Hanqing Zhao, Robin Randhawa, Michal Rostecki, Wei Liu... For additional acknowledgements, please see the RFC from April. Miguel Ojeda (17): kallsyms: support big kernel symbols (2-byte lengths) kallsyms: increase maximum kernel symbol length to 512 Makefile: generate `CLANG_FLAGS` even in GCC builds vsprintf: add new `%pA` format specifier rust: add C helpers rust: add `compiler_builtins` crate rust: add `alloc` crate rust: add `build_error` crate rust: add `macros` crate rust: add `kernel` crate rust: export generated symbols Kbuild: add Rust support docs: add Rust documentation samples: add Rust examples scripts: add `generate_rust_analyzer.py` MAINTAINERS: Rust Android: Binder IPC in Rust (WIP) .gitignore | 5 + .rustfmt.toml | 12 + Documentation/doc-guide/kernel-doc.rst | 3 + Documentation/index.rst | 1 + Documentation/kbuild/kbuild.rst | 4 + Documentation/process/changes.rst | 13 + Documentation/rust/arch-support.rst | 35 + Documentation/rust/assets/favicon-16x16.png | Bin 0 -> 798 bytes Documentation/rust/assets/favicon-32x32.png | Bin 0 -> 2076 bytes Documentation/rust/assets/rust-logo.png | Bin 0 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include/uapi/linux/android/binder.h | 28 +- init/Kconfig | 28 + kernel/kallsyms.c | 7 + kernel/livepatch/core.c | 4 +- kernel/printk/printk.c | 5 +- lib/Kconfig.debug | 144 + lib/vsprintf.c | 12 + rust/.gitignore | 6 + rust/Makefile | 316 ++ rust/alloc/README.md | 32 + rust/alloc/alloc.rs | 425 +++ rust/alloc/borrow.rs | 493 +++ rust/alloc/boxed.rs | 1728 ++++++++++ rust/alloc/collections/mod.rs | 116 + rust/alloc/fmt.rs | 587 ++++ rust/alloc/lib.rs | 197 ++ rust/alloc/macros.rs | 128 + rust/alloc/prelude/mod.rs | 17 + rust/alloc/prelude/v1.rs | 16 + rust/alloc/raw_vec.rs | 612 ++++ rust/alloc/rc.rs | 2539 +++++++++++++++ rust/alloc/slice.rs | 1271 ++++++++ rust/alloc/str.rs | 614 ++++ rust/alloc/string.rs | 2847 ++++++++++++++++ rust/alloc/sync.rs | 2631 +++++++++++++++ rust/alloc/vec/drain.rs | 157 + rust/alloc/vec/drain_filter.rs | 145 + rust/alloc/vec/into_iter.rs | 296 ++ rust/alloc/vec/is_zero.rs | 106 + rust/alloc/vec/mod.rs | 3255 +++++++++++++++++++ rust/alloc/vec/partial_eq.rs | 49 + rust/alloc/vec/set_len_on_drop.rs | 30 + rust/alloc/vec/spec_extend.rs | 170 + rust/bindgen_parameters | 13 + rust/build_error.rs | 33 + rust/compiler_builtins.rs | 146 + rust/exports.c | 16 + rust/helpers.c | 235 ++ rust/kernel/allocator.rs | 63 + rust/kernel/bindings.rs | 28 + rust/kernel/bindings_helper.h | 24 + rust/kernel/buffer.rs | 39 + rust/kernel/build_assert.rs | 80 + rust/kernel/c_types.rs | 119 + rust/kernel/chrdev.rs | 212 ++ rust/kernel/error.rs | 272 ++ rust/kernel/file.rs | 130 + rust/kernel/file_operations.rs | 698 ++++ rust/kernel/io_buffer.rs | 153 + rust/kernel/iov_iter.rs | 95 + rust/kernel/lib.rs | 220 ++ rust/kernel/linked_list.rs | 245 ++ rust/kernel/miscdev.rs | 113 + rust/kernel/module_param.rs | 497 +++ rust/kernel/of.rs | 101 + rust/kernel/pages.rs | 176 + rust/kernel/platdev.rs | 166 + rust/kernel/prelude.rs | 28 + rust/kernel/print.rs | 412 +++ rust/kernel/random.rs | 50 + rust/kernel/raw_list.rs | 361 ++ rust/kernel/rbtree.rs | 570 ++++ rust/kernel/security.rs | 79 + rust/kernel/static_assert.rs | 39 + rust/kernel/str.rs | 259 ++ rust/kernel/sync/arc.rs | 227 ++ rust/kernel/sync/condvar.rs | 136 + rust/kernel/sync/guard.rs | 82 + rust/kernel/sync/locked_by.rs | 112 + rust/kernel/sync/mod.rs | 84 + rust/kernel/sync/mutex.rs | 101 + rust/kernel/sync/spinlock.rs | 109 + rust/kernel/sysctl.rs | 198 ++ rust/kernel/task.rs | 193 ++ rust/kernel/traits.rs | 26 + rust/kernel/types.rs | 249 ++ rust/kernel/user_ptr.rs | 191 ++ rust/macros/lib.rs | 127 + rust/macros/module.rs | 754 +++++ samples/Kconfig | 2 + samples/Makefile | 1 + samples/rust/Kconfig | 113 + samples/rust/Makefile | 12 + samples/rust/rust_chrdev.rs | 51 + samples/rust/rust_minimal.rs | 38 + samples/rust/rust_miscdev.rs | 150 + samples/rust/rust_module_parameters.rs | 72 + samples/rust/rust_print.rs | 57 + samples/rust/rust_random.rs | 61 + samples/rust/rust_semaphore.rs | 177 + samples/rust/rust_semaphore_c.c | 212 ++ samples/rust/rust_stack_probing.rs | 40 + samples/rust/rust_sync.rs | 81 + scripts/Makefile.build | 22 + scripts/Makefile.lib | 12 + scripts/generate_rust_analyzer.py | 143 + scripts/kallsyms.c | 33 +- scripts/kconfig/confdata.c | 67 +- scripts/rust-version.sh | 31 + tools/include/linux/kallsyms.h | 2 +- tools/include/linux/lockdep.h | 2 +- tools/lib/perf/include/perf/event.h | 2 +- tools/lib/symbol/kallsyms.h | 2 +- 141 files changed, 33003 insertions(+), 45 deletions(-) create mode 100644 .rustfmt.toml create mode 100644 Documentation/rust/arch-support.rst create mode 100644 Documentation/rust/assets/favicon-16x16.png create mode 100644 Documentation/rust/assets/favicon-32x32.png create mode 100644 Documentation/rust/assets/rust-logo.png create mode 100644 Documentation/rust/coding.rst create mode 100644 Documentation/rust/docs.rst create mode 100644 Documentation/rust/index.rst create mode 100644 Documentation/rust/quick-start.rst create mode 100644 arch/arm/rust/target.json create 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rust/alloc/collections/mod.rs create mode 100644 rust/alloc/fmt.rs create mode 100644 rust/alloc/lib.rs create mode 100644 rust/alloc/macros.rs create mode 100644 rust/alloc/prelude/mod.rs create mode 100644 rust/alloc/prelude/v1.rs create mode 100644 rust/alloc/raw_vec.rs create mode 100644 rust/alloc/rc.rs create mode 100644 rust/alloc/slice.rs create mode 100644 rust/alloc/str.rs create mode 100644 rust/alloc/string.rs create mode 100644 rust/alloc/sync.rs create mode 100644 rust/alloc/vec/drain.rs create mode 100644 rust/alloc/vec/drain_filter.rs create mode 100644 rust/alloc/vec/into_iter.rs create mode 100644 rust/alloc/vec/is_zero.rs create mode 100644 rust/alloc/vec/mod.rs create mode 100644 rust/alloc/vec/partial_eq.rs create mode 100644 rust/alloc/vec/set_len_on_drop.rs create mode 100644 rust/alloc/vec/spec_extend.rs create mode 100644 rust/bindgen_parameters create mode 100644 rust/build_error.rs create mode 100644 rust/compiler_builtins.rs create mode 100644 rust/exports.c create mode 100644 rust/helpers.c create mode 100644 rust/kernel/allocator.rs create mode 100644 rust/kernel/bindings.rs create mode 100644 rust/kernel/bindings_helper.h create mode 100644 rust/kernel/buffer.rs create mode 100644 rust/kernel/build_assert.rs create mode 100644 rust/kernel/c_types.rs create mode 100644 rust/kernel/chrdev.rs create mode 100644 rust/kernel/error.rs create mode 100644 rust/kernel/file.rs create mode 100644 rust/kernel/file_operations.rs create mode 100644 rust/kernel/io_buffer.rs create mode 100644 rust/kernel/iov_iter.rs create mode 100644 rust/kernel/lib.rs create mode 100644 rust/kernel/linked_list.rs create mode 100644 rust/kernel/miscdev.rs create mode 100644 rust/kernel/module_param.rs create mode 100644 rust/kernel/of.rs create mode 100644 rust/kernel/pages.rs create mode 100644 rust/kernel/platdev.rs create mode 100644 rust/kernel/prelude.rs create mode 100644 rust/kernel/print.rs create mode 100644 rust/kernel/random.rs create mode 100644 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