Rust support
This is the patch series (v6) 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
As usual, special thanks go to ISRG (Internet Security Research Group) and Google for their financial support on this endeavor.
Cheers, Miguel
--
# Rust support
This cover letter explains the major changes and updates done since the previous ones. For those, please see:
RFC: https://lore.kernel.org/lkml/20210414184604.23473-1-ojeda@kernel.org/ v1: https://lore.kernel.org/lkml/20210704202756.29107-1-ojeda@kernel.org/ v2: https://lore.kernel.org/lkml/20211206140313.5653-1-ojeda@kernel.org/ v3: https://lore.kernel.org/lkml/20220117053349.6804-1-ojeda@kernel.org/ v4: https://lore.kernel.org/lkml/20220212130410.6901-1-ojeda@kernel.org/ v5: https://lore.kernel.org/lkml/20220317181032.15436-1-ojeda@kernel.org/
## Infrastructure updates
There have been several improvements to the overall Rust support:
- The toolchain and `alloc` have been upgraded to Rust 1.60.0. This version stabilized `feature(maybe_uninit_extra)` that we are using.
- Support running documentation tests in-kernel, based on KUnit.
Rust documentation tests are typically examples of usage of any item (e.g. function, struct, module...). They are very convenient because they are just written alongside the documentation, e.g.:
/// Sums two numbers. /// /// # Examples /// /// ``` /// assert_eq!(mymod::f(10, 20), 30); /// ``` pub fn f(a: i32, b: i32) -> i32 { a + b }
So far, we were compiling and running them in the host as any other Rust documentation test. However, that meant we could not run tests that used kernel APIs (though we were compile-testing them, which was already useful to keep the documentation in sync with the code).
Now, the documentation tests for the `kernel` crate are transformed into a KUnit test suite during compilation and run within the kernel at boot time, if enabled. This means now we can run the tests that use kernel APIs.
They look like this (their name is generated by `rustdoc`, based on the file and line):
[ 0.581961] TAP version 14 [ 0.582092] 1..1 [ 0.582267] # Subtest: rust_kernel_doctests [ 0.582358] 1..70 [ 0.583626] ok 1 - rust_kernel_doctest_build_assert_rs_12_0 [ 0.584579] ok 2 - rust_kernel_doctest_build_assert_rs_55_0 [ 0.587357] ok 3 - rust_kernel_doctest_device_rs_361_0 [ 0.588037] ok 4 - rust_kernel_doctest_device_rs_386_0
...
[ 0.659249] ok 69 - rust_kernel_doctest_types_rs_445_0 [ 0.660451] ok 70 - rust_kernel_doctest_types_rs_509_0 [ 0.660680] # rust_kernel_doctests: pass:70 fail:0 skip:0 total:70 [ 0.660894] # Totals: pass:70 fail:0 skip:0 total:70 [ 0.661135] ok 1 - rust_kernel_doctests
There are other benefits from this, such as being able to remove unneeded wrapper functions (that were used to avoid running some tests) as well as ensuring test code would actually compile within the kernel (e.g. `alloc` used different `cfg`s).
- Tests are now (and are enforced to be) Clippy-clean, like the rest of the Rust kernel code (i.e. according to the same rules).
- Other cleanups, fixes and improvements.
## Abstractions and driver updates
Some of the improvements to the abstractions and example drivers are:
- The start of networking support (`net` module), with types like:
+ `Namespace` (based on `struct net`). + `SkBuff` (based on `struct sk_buff`). + `Ipv4Addr` (based on `struct in_addr`), and its v6 equivalent. + `SocketAddrV4` (based on `struct sockaddr_in`), and its v6 equivalent. + `TcpListener` and `TcpStream` (based on `struct socket`).
- The beginning of `async` support (`kasync` module).
Rust provides support for asynchronous programming in a way that can be used in constrained environments, including the kernel.
For instance, this allows us to write asynchronous TCP socket code within the kernel such as:
async fn echo_server(stream: TcpStream) -> Result { let mut buf = [0u8; 1024]; loop { let n = stream.read(&mut buf).await?; if n == 0 { return Ok(()); } stream.write_all(&buf[..n]).await?; } }
This code looks very close to a synchronous version, yet it supports being driven to completion "step by step" by an executor. The `read()`/`write_all()` calls above, instead of blocking the current thread, return a future which can be polled. The `.await` points poll the future and, if the result is not ready, suspend the state such that execution resumes there later on (the state machine needed for this gets implemented by the compiler). This allows an executor to drive multiple futures to completion concurrently on the same thread.
An executor is not included yet, but `kasync` includes async versions of `TcpListener` and `TcpStream` (based on the non-async ones) which employ `SocketFuture` (which in turn uses a `struct wait_queue_entry`).
- Support for network packet filters (`net::filter` module) and its related `rust_netfilter.rs` sample.
- Added `smutex::Mutex`: a simple mutex that does not require pinning, so that the ergonomics are much improved, though the implementation is not as feature-rich as the C-based one.
- New `NoWaitLock`: one that never waits, that is, if it is owned by another thread/CPU, then attempts to acquire it will fail (instead of, for example, blocking the caller).
- Added `RawSpinLock` (backed by `raw_spinlock_t`), used when code sections cannot sleep even in real-time variants of the kernel.
- Added `ARef`, an owned reference to an always-refcounted object, meant to simplify how we define wrappers to types defined on the C side of the source code.
- Other cleanups, fixes and improvements.
## Patch series status
The Rust support is still to be considered experimental. However, support is good enough that kernel developers can start working on the Rust abstractions for subsystems and write drivers and other modules.
The current series has just arrived in `linux-next`, as usual. Similarly, the preview docs for this series can be seen at:
https://rust-for-linux.github.io/docs/kernel/
As usual, please see the following link for the live list of unstable Rust features we are using:
https://github.com/Rust-for-Linux/linux/issues/2
## Conferences, meetings and liaisons
We would like to announce the Rust MC (microconference) in the upcoming LPC 2022 (Linux Plumbers Conference):
https://lpc.events/event/16/contributions/1159/
The Rust MC intends to cover talks and discussions on both Rust for Linux as well as other non-kernel Rust topics. The Call for Proposals is open!
Furthermore, we would like to thank you the venues we were invited to:
- Rust Linz 2022 - Linux Foundation Live Mentorship Series
## Related news
`rustc_codegen_gcc` (the GCC backend for `rustc`) can now bootstrap `rustc`! In addition, GCC 12.1 (just released) carries some of the patches that were needed by the project in upstream `libgccjit`; and the project is looking into getting distributed with `rustup`.
`gccrs` (the Rust frontend for GCC) has got a second full time developer working on it, Arthur Cohen, as well as a lot of technical progress too, such as a new testing project, slice generation support and macro-related work.
## 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 previous cover letter:
- Andy Shevchenko, Petr Mladek, Sergey Senozhatsky for their review of the `vsprintf` patch.
- Arnaldo Carvalho de Melo and Andrii Nakryiko for their input on `pahole` and BTF, Arnaldo for adding support `pahole` for `--lang` and `--lang_exclude` (useful to skip Rust CUs) and Martin Reboredo for reporting the `CONFIG_DEBUG_INFO_BTF` issue.
- Daniel Latypov, David Gow and Brendan Higgins for their input on KUnit and their reviews on a prerequisite Rust patch on it.
- Kees Cook for reviewing the kallsyms prerequisite patches.
- Greg Kroah-Hartman for his suggestions on the `alloc` patch.
- Daniel Paoliello for his ongoing work on adding more `try_*` methods to `Vec` in the standard library. Currently, we have some similar methods in our custom `alloc` that we could drop once equivalents arrive upstream. Also John Ericson for his reviews.
- bjorn3 for reviewing many PRs and the input around potential UB in doctests.
- As usual, bjorn3 and Gary Guo for all the input on Rust compiler details and suggestions.
- Adam Bratschi-Kaye for working on `seq_file` and `debugfs` abstractions.
- Maciej Falkowski for continuing his work on the Samsung Exynos TRNG driver and the required abstractions around it, such as adding `delay`, `ktime` and `iopoll` abstractions, new methods to `platform::Device` and run-time power management abstractions.
- Daniel Xu for working on adding a Rust allocator based on the `kvmalloc` family of functions.
- Hongyu Li for working on Rust iterators as the equivalent of `cpumask`'s `for_each_*_cpu`.
- Andreas Hindborg for adding support to `kernel::Pages` methods to allow read/write of multiple pages.
- Sergio González Collado for working on adding `#[cold]` attributes for error-related items and GitHub CI problem matchers.
- Sean Nash for updating the out-of-tree-module example due to a change in the main repository.
- Michael Ellerman, Nicholas Piggin, Paul E. McKenney and Zhouyi Zhou for debugging the `CONFIG_HIGH_RES_TIMERS=n` stall issue in PowerPC that we triggered in our CI.
- Jonathan Corbet for writing an LWN article on the crates discussion that took place in the Rust for Linux mailing list.
- Wei Liu for taking the time to answer questions from newcomers in Zulip.
- Philip Li, Yujie Liu et al. for continuing their work on adding Rust support to the Intel 0DAY/LKP kernel test robot.
- Philip Herron and Arthur Cohen (and his supporters Open Source Security and Embecosm) et al. for their ongoing work on GCC Rust.
- Antoni Boucher (and his supporters) et al. for their ongoing work on `rustc_codegen_gcc`.
- Mats Larsen, Marc Poulhiès et al. for their ongoing work on improving Rust support in Compiler Explorer.
- Many folks that have reported issues, tested the project, helped spread the word, joined discussions and contributed in other ways!
Please see also the acknowledgements on the previous cover letters.
Boqun Feng (1): kallsyms: avoid hardcoding the buffer size
Gary Guo (2): rust: add `build_error` crate vsprintf: add new `%pA` format specifier
Miguel Ojeda (16): kallsyms: support "big" kernel symbols kallsyms: increase maximum kernel symbol length to 512 kunit: take `kunit_assert` as `const` rust: add C helpers rust: add `compiler_builtins` crate rust: import upstream `alloc` crate rust: adapt `alloc` crate to the kernel rust: add `macros` crate rust: export generated symbols scripts: add `rustdoc_test_{builder,gen}.py` scripts scripts: add `generate_rust_analyzer.py` scripts scripts: decode_stacktrace: demangle Rust symbols docs: add Rust documentation Kbuild: add Rust support samples: add Rust examples MAINTAINERS: Rust
Wedson Almeida Filho (4): rust: add `kernel` crate's `sync` module rust: add `kernel` crate [RFC] drivers: gpio: PrimeCell PL061 in Rust [RFC] drivers: android: Binder IPC in Rust
.gitignore | 5 + .rustfmt.toml | 12 + Documentation/doc-guide/kernel-doc.rst | 3 + Documentation/index.rst | 1 + Documentation/kbuild/kbuild.rst | 17 + Documentation/kbuild/makefiles.rst | 50 +- Documentation/process/changes.rst | 41 + Documentation/rust/arch-support.rst | 34 + Documentation/rust/coding-guidelines.rst | 214 ++ Documentation/rust/general-information.rst | 77 + Documentation/rust/index.rst | 20 + Documentation/rust/logo.svg | 357 ++ Documentation/rust/quick-start.rst | 230 ++ MAINTAINERS | 15 + Makefile | 175 +- arch/Kconfig | 6 + arch/arm/Kconfig | 1 + arch/arm64/Kconfig | 1 + arch/powerpc/Kconfig | 1 + arch/riscv/Kconfig | 1 + arch/riscv/Makefile | 5 + arch/x86/Kconfig | 1 + arch/x86/Makefile | 14 + drivers/android/Kconfig | 6 + drivers/android/Makefile | 2 + drivers/android/allocation.rs | 266 ++ drivers/android/context.rs | 80 + drivers/android/defs.rs | 99 + drivers/android/node.rs | 476 +++ drivers/android/process.rs | 960 +++++ drivers/android/range_alloc.rs | 189 + drivers/android/rust_binder.rs | 111 + drivers/android/thread.rs | 870 +++++ drivers/android/transaction.rs | 326 ++ drivers/gpio/Kconfig | 8 + drivers/gpio/Makefile | 1 + drivers/gpio/gpio_pl061_rust.rs | 370 ++ include/kunit/test.h | 2 +- include/linux/kallsyms.h | 2 +- include/linux/spinlock.h | 25 +- include/uapi/linux/android/binder.h | 28 +- init/Kconfig | 45 +- kernel/kallsyms.c | 26 +- kernel/livepatch/core.c | 4 +- lib/Kconfig.debug | 155 + lib/kunit/test.c | 4 +- lib/vsprintf.c | 13 + rust/.gitignore | 10 + rust/Makefile | 397 +++ rust/alloc/README.md | 32 + rust/alloc/alloc.rs | 438 +++ rust/alloc/borrow.rs | 498 +++ rust/alloc/boxed.rs | 2007 +++++++++++ rust/alloc/collections/mod.rs | 156 + rust/alloc/fmt.rs | 601 ++++ rust/alloc/lib.rs | 226 ++ rust/alloc/macros.rs | 127 + rust/alloc/raw_vec.rs | 567 +++ rust/alloc/slice.rs | 1282 +++++++ rust/alloc/str.rs | 632 ++++ rust/alloc/string.rs | 2869 +++++++++++++++ rust/alloc/vec/drain.rs | 186 + rust/alloc/vec/drain_filter.rs | 145 + rust/alloc/vec/into_iter.rs | 356 ++ rust/alloc/vec/is_zero.rs | 106 + rust/alloc/vec/mod.rs | 3362 ++++++++++++++++++ rust/alloc/vec/partial_eq.rs | 49 + rust/alloc/vec/set_len_on_drop.rs | 30 + rust/alloc/vec/spec_extend.rs | 174 + rust/bindgen_parameters | 17 + rust/build_error.rs | 29 + rust/compiler_builtins.rs | 57 + rust/exports.c | 20 + rust/helpers.c | 639 ++++ rust/kernel/allocator.rs | 65 + rust/kernel/amba.rs | 257 ++ rust/kernel/bindings.rs | 47 + rust/kernel/bindings_helper.h | 46 + rust/kernel/build_assert.rs | 82 + rust/kernel/c_types.rs | 119 + rust/kernel/chrdev.rs | 207 ++ rust/kernel/clk.rs | 79 + rust/kernel/cred.rs | 46 + rust/kernel/device.rs | 546 +++ rust/kernel/driver.rs | 442 +++ rust/kernel/error.rs | 565 +++ rust/kernel/file.rs | 860 +++++ rust/kernel/gpio.rs | 478 +++ rust/kernel/hwrng.rs | 242 ++ rust/kernel/io_buffer.rs | 153 + rust/kernel/io_mem.rs | 275 ++ rust/kernel/iov_iter.rs | 81 + rust/kernel/irq.rs | 409 +++ rust/kernel/kasync.rs | 6 + rust/kernel/kasync/net.rs | 322 ++ rust/kernel/kunit.rs | 91 + rust/kernel/lib.rs | 260 ++ rust/kernel/linked_list.rs | 247 ++ rust/kernel/miscdev.rs | 291 ++ rust/kernel/mm.rs | 149 + rust/kernel/module_param.rs | 498 +++ rust/kernel/net.rs | 392 ++ rust/kernel/net/filter.rs | 447 +++ rust/kernel/of.rs | 63 + rust/kernel/pages.rs | 144 + rust/kernel/platform.rs | 223 ++ rust/kernel/power.rs | 118 + rust/kernel/prelude.rs | 36 + rust/kernel/print.rs | 405 +++ rust/kernel/random.rs | 42 + rust/kernel/raw_list.rs | 361 ++ rust/kernel/rbtree.rs | 563 +++ rust/kernel/revocable.rs | 161 + rust/kernel/security.rs | 38 + rust/kernel/static_assert.rs | 38 + rust/kernel/std_vendor.rs | 160 + rust/kernel/str.rs | 597 ++++ rust/kernel/sync.rs | 161 + rust/kernel/sync/arc.rs | 503 +++ rust/kernel/sync/condvar.rs | 138 + rust/kernel/sync/guard.rs | 169 + rust/kernel/sync/locked_by.rs | 111 + rust/kernel/sync/mutex.rs | 153 + rust/kernel/sync/nowait.rs | 188 + rust/kernel/sync/revocable.rs | 250 ++ rust/kernel/sync/rwsem.rs | 197 + rust/kernel/sync/seqlock.rs | 202 ++ rust/kernel/sync/smutex.rs | 295 ++ rust/kernel/sync/spinlock.rs | 360 ++ rust/kernel/sysctl.rs | 199 ++ rust/kernel/task.rs | 175 + rust/kernel/types.rs | 679 ++++ rust/kernel/user_ptr.rs | 175 + rust/macros/helpers.rs | 79 + rust/macros/lib.rs | 94 + rust/macros/module.rs | 631 ++++ samples/Kconfig | 2 + samples/Makefile | 1 + samples/rust/Kconfig | 140 + samples/rust/Makefile | 16 + samples/rust/hostprogs/.gitignore | 3 + samples/rust/hostprogs/Makefile | 5 + samples/rust/hostprogs/a.rs | 7 + samples/rust/hostprogs/b.rs | 5 + samples/rust/hostprogs/single.rs | 12 + samples/rust/rust_chrdev.rs | 50 + samples/rust/rust_minimal.rs | 35 + samples/rust/rust_miscdev.rs | 143 + samples/rust/rust_module_parameters.rs | 69 + samples/rust/rust_netfilter.rs | 54 + samples/rust/rust_platform.rs | 22 + samples/rust/rust_print.rs | 54 + samples/rust/rust_random.rs | 60 + samples/rust/rust_semaphore.rs | 171 + samples/rust/rust_semaphore_c.c | 212 ++ samples/rust/rust_stack_probing.rs | 36 + samples/rust/rust_sync.rs | 93 + scripts/.gitignore | 1 + scripts/Kconfig.include | 6 +- scripts/Makefile | 3 + scripts/Makefile.build | 60 + scripts/Makefile.debug | 10 + scripts/Makefile.host | 34 +- scripts/Makefile.lib | 12 + scripts/Makefile.modfinal | 8 +- scripts/cc-version.sh | 12 +- scripts/decode_stacktrace.sh | 14 + scripts/generate_rust_analyzer.py | 134 + scripts/generate_rust_target.rs | 227 ++ scripts/is_rust_module.sh | 13 + scripts/kallsyms.c | 47 +- scripts/kconfig/confdata.c | 75 + scripts/min-tool-version.sh | 6 + scripts/rust-is-available-bindgen-libclang.h | 2 + scripts/rust-is-available.sh | 158 + scripts/rustdoc_test_builder.py | 59 + scripts/rustdoc_test_gen.py | 164 + tools/include/linux/kallsyms.h | 2 +- tools/lib/perf/include/perf/event.h | 2 +- tools/lib/symbol/kallsyms.h | 2 +- 180 files changed, 37945 insertions(+), 67 deletions(-) create mode 100644 .rustfmt.toml create mode 100644 Documentation/rust/arch-support.rst create mode 100644 Documentation/rust/coding-guidelines.rst create mode 100644 Documentation/rust/general-information.rst create mode 100644 Documentation/rust/index.rst create mode 100644 Documentation/rust/logo.svg create mode 100644 Documentation/rust/quick-start.rst create mode 100644 drivers/android/allocation.rs create mode 100644 drivers/android/context.rs create mode 100644 drivers/android/defs.rs create mode 100644 drivers/android/node.rs create mode 100644 drivers/android/process.rs create mode 100644 drivers/android/range_alloc.rs create mode 100644 drivers/android/rust_binder.rs create mode 100644 drivers/android/thread.rs create mode 100644 drivers/android/transaction.rs create mode 100644 drivers/gpio/gpio_pl061_rust.rs create mode 100644 rust/.gitignore create mode 100644 rust/Makefile create mode 100644 rust/alloc/README.md create mode 100644 rust/alloc/alloc.rs create mode 100644 rust/alloc/borrow.rs create mode 100644 rust/alloc/boxed.rs create mode 100644 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/raw_vec.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/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/amba.rs create mode 100644 rust/kernel/bindings.rs create mode 100644 rust/kernel/bindings_helper.h 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/clk.rs create mode 100644 rust/kernel/cred.rs create mode 100644 rust/kernel/device.rs create mode 100644 rust/kernel/driver.rs create mode 100644 rust/kernel/error.rs create mode 100644 rust/kernel/file.rs create mode 100644 rust/kernel/gpio.rs create mode 100644 rust/kernel/hwrng.rs create mode 100644 rust/kernel/io_buffer.rs create mode 100644 rust/kernel/io_mem.rs create mode 100644 rust/kernel/iov_iter.rs create mode 100644 rust/kernel/irq.rs create mode 100644 rust/kernel/kasync.rs create mode 100644 rust/kernel/kasync/net.rs create mode 100644 rust/kernel/kunit.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/mm.rs create mode 100644 rust/kernel/module_param.rs create mode 100644 rust/kernel/net.rs create mode 100644 rust/kernel/net/filter.rs create mode 100644 rust/kernel/of.rs create mode 100644 rust/kernel/pages.rs create mode 100644 rust/kernel/platform.rs create mode 100644 rust/kernel/power.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 rust/kernel/raw_list.rs create mode 100644 rust/kernel/rbtree.rs create mode 100644 rust/kernel/revocable.rs create mode 100644 rust/kernel/security.rs create mode 100644 rust/kernel/static_assert.rs create mode 100644 rust/kernel/std_vendor.rs create mode 100644 rust/kernel/str.rs create mode 100644 rust/kernel/sync.rs create mode 100644 rust/kernel/sync/arc.rs create mode 100644 rust/kernel/sync/condvar.rs create mode 100644 rust/kernel/sync/guard.rs create mode 100644 rust/kernel/sync/locked_by.rs create mode 100644 rust/kernel/sync/mutex.rs create mode 100644 rust/kernel/sync/nowait.rs create mode 100644 rust/kernel/sync/revocable.rs create mode 100644 rust/kernel/sync/rwsem.rs create mode 100644 rust/kernel/sync/seqlock.rs create mode 100644 rust/kernel/sync/smutex.rs create mode 100644 rust/kernel/sync/spinlock.rs create mode 100644 rust/kernel/sysctl.rs create mode 100644 rust/kernel/task.rs create mode 100644 rust/kernel/types.rs create mode 100644 rust/kernel/user_ptr.rs create mode 100644 rust/macros/helpers.rs create mode 100644 rust/macros/lib.rs create mode 100644 rust/macros/module.rs create mode 100644 samples/rust/Kconfig create mode 100644 samples/rust/Makefile create mode 100644 samples/rust/hostprogs/.gitignore create mode 100644 samples/rust/hostprogs/Makefile create mode 100644 samples/rust/hostprogs/a.rs create mode 100644 samples/rust/hostprogs/b.rs create mode 100644 samples/rust/hostprogs/single.rs create mode 100644 samples/rust/rust_chrdev.rs create mode 100644 samples/rust/rust_minimal.rs create mode 100644 samples/rust/rust_miscdev.rs create mode 100644 samples/rust/rust_module_parameters.rs create mode 100644 samples/rust/rust_netfilter.rs create mode 100644 samples/rust/rust_platform.rs create mode 100644 samples/rust/rust_print.rs create mode 100644 samples/rust/rust_random.rs create mode 100644 samples/rust/rust_semaphore.rs create mode 100644 samples/rust/rust_semaphore_c.c create mode 100644 samples/rust/rust_stack_probing.rs create mode 100644 samples/rust/rust_sync.rs create mode 100755 scripts/generate_rust_analyzer.py create mode 100644 scripts/generate_rust_target.rs create mode 100755 scripts/is_rust_module.sh create mode 100644 scripts/rust-is-available-bindgen-libclang.h create mode 100755 scripts/rust-is-available.sh create mode 100755 scripts/rustdoc_test_builder.py create mode 100755 scripts/rustdoc_test_gen.py
base-commit: 672c0c5173427e6b3e2a9bbb7be51ceeec78093a
The `kunit_do_failed_assertion` function passes its `struct kunit_assert` argument to `kunit_fail`. This one, in turn, calls its `format` field passing the assert again as a `const` pointer.
Therefore, the whole chain may be made `const`.
Reviewed-by: Daniel Latypov dlatypov@google.com Signed-off-by: Miguel Ojeda ojeda@kernel.org --- This is a prerequisite patch, independently submitted at:
https://lore.kernel.org/lkml/20220502093625.GA23225@kernel.org/
include/kunit/test.h | 2 +- lib/kunit/test.c | 4 ++-- 2 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/include/kunit/test.h b/include/kunit/test.h index 00b9ff7783ab..2eff4f1beb42 100644 --- a/include/kunit/test.h +++ b/include/kunit/test.h @@ -774,7 +774,7 @@ void __printf(2, 3) kunit_log_append(char *log, const char *fmt, ...); void kunit_do_failed_assertion(struct kunit *test, const struct kunit_loc *loc, enum kunit_assert_type type, - struct kunit_assert *assert, + const struct kunit_assert *assert, const char *fmt, ...);
#define KUNIT_ASSERTION(test, assert_type, pass, assert_class, INITIALIZER, fmt, ...) do { \ diff --git a/lib/kunit/test.c b/lib/kunit/test.c index 3bca3bf5c15b..b84aed09a009 100644 --- a/lib/kunit/test.c +++ b/lib/kunit/test.c @@ -241,7 +241,7 @@ static void kunit_print_string_stream(struct kunit *test, }
static void kunit_fail(struct kunit *test, const struct kunit_loc *loc, - enum kunit_assert_type type, struct kunit_assert *assert, + enum kunit_assert_type type, const struct kunit_assert *assert, const struct va_format *message) { struct string_stream *stream; @@ -281,7 +281,7 @@ static void __noreturn kunit_abort(struct kunit *test) void kunit_do_failed_assertion(struct kunit *test, const struct kunit_loc *loc, enum kunit_assert_type type, - struct kunit_assert *assert, + const struct kunit_assert *assert, const char *fmt, ...) { va_list args;
On Sat, May 7, 2022 at 1:26 AM Miguel Ojeda ojeda@kernel.org wrote:
The `kunit_do_failed_assertion` function passes its `struct kunit_assert` argument to `kunit_fail`. This one, in turn, calls its `format` field passing the assert again as a `const` pointer.
Therefore, the whole chain may be made `const`.
Reviewed-by: Daniel Latypov dlatypov@google.com Signed-off-by: Miguel Ojeda ojeda@kernel.org
Reviewed-by: Brendan Higgins brendanhiggins@google.com
On Sat, May 07, 2022 at 07:23:58AM +0200, Miguel Ojeda wrote:
## Patch series status
The Rust support is still to be considered experimental. However, support is good enough that kernel developers can start working on the Rust abstractions for subsystems and write drivers and other modules.
I'd really like to see this landed for a few reasons:
- It's under active development, and I'd rather review the changes "normally", incrementally, etc. Right now it can be hard to re-review some of the "mostly the same each version" patches in the series.
- I'd like to break the catch-22 of "ask for a new driver to be written in rust but the rust support isn't landed" vs "the rust support isn't landed because there aren't enough drivers". It really feels like "release early, release often" is needed here; it's hard to develop against -next. :)
Should we give it a try for this coming merge window?
On Sat, May 07, 2022 at 01:06:18AM -0700, Kees Cook wrote:
On Sat, May 07, 2022 at 07:23:58AM +0200, Miguel Ojeda wrote:
## Patch series status
The Rust support is still to be considered experimental. However, support is good enough that kernel developers can start working on the Rust abstractions for subsystems and write drivers and other modules.
I'd really like to see this landed for a few reasons:
It's under active development, and I'd rather review the changes "normally", incrementally, etc. Right now it can be hard to re-review some of the "mostly the same each version" patches in the series.
I'd like to break the catch-22 of "ask for a new driver to be written in rust but the rust support isn't landed" vs "the rust support isn't landed because there aren't enough drivers". It really feels like "release early, release often" is needed here; it's hard to develop against -next. :)
Should we give it a try for this coming merge window?
I'm broadly in favour of that. It's just code, we can always drop it again or fix it. There's sufficient development community around it that it's hardly going to become abandonware.
On Sat, May 07, 2022 at 01:06:18AM -0700, Kees Cook wrote:
On Sat, May 07, 2022 at 07:23:58AM +0200, Miguel Ojeda wrote:
## Patch series status
The Rust support is still to be considered experimental. However, support is good enough that kernel developers can start working on the Rust abstractions for subsystems and write drivers and other modules.
I'd really like to see this landed for a few reasons:
It's under active development, and I'd rather review the changes "normally", incrementally, etc. Right now it can be hard to re-review some of the "mostly the same each version" patches in the series.
I'd like to break the catch-22 of "ask for a new driver to be written in rust but the rust support isn't landed" vs "the rust support isn't landed because there aren't enough drivers". It really feels like "release early, release often" is needed here; it's hard to develop against -next. :)
+1 to both points. :-)
On Sat, May 7, 2022 at 1:25 PM Miguel Ojeda ojeda@kernel.org wrote:
Rust support
<...>
Support running documentation tests in-kernel, based on KUnit.
Rust documentation tests are typically examples of usage of any item (e.g. function, struct, module...). They are very convenient because they are just written alongside the documentation, e.g.:
/// Sums two numbers. /// /// # Examples /// /// ``` /// assert_eq!(mymod::f(10, 20), 30); /// ``` pub fn f(a: i32, b: i32) -> i32 { a + b }So far, we were compiling and running them in the host as any other Rust documentation test. However, that meant we could not run tests that used kernel APIs (though we were compile-testing them, which was already useful to keep the documentation in sync with the code).
Now, the documentation tests for the `kernel` crate are transformed into a KUnit test suite during compilation and run within the kernel at boot time, if enabled. This means now we can run the tests that use kernel APIs.
They look like this (their name is generated by `rustdoc`, based on the file and line):
[ 0.581961] TAP version 14 [ 0.582092] 1..1 [ 0.582267] # Subtest: rust_kernel_doctests [ 0.582358] 1..70 [ 0.583626] ok 1 - rust_kernel_doctest_build_assert_rs_12_0 [ 0.584579] ok 2 - rust_kernel_doctest_build_assert_rs_55_0 [ 0.587357] ok 3 - rust_kernel_doctest_device_rs_361_0 [ 0.588037] ok 4 - rust_kernel_doctest_device_rs_386_0 ... [ 0.659249] ok 69 - rust_kernel_doctest_types_rs_445_0 [ 0.660451] ok 70 - rust_kernel_doctest_types_rs_509_0 [ 0.660680] # rust_kernel_doctests: pass:70 fail:0 skip:0 total:70 [ 0.660894] # Totals: pass:70 fail:0 skip:0 total:70 [ 0.661135] ok 1 - rust_kernel_doctestsThere are other benefits from this, such as being able to remove unneeded wrapper functions (that were used to avoid running some tests) as well as ensuring test code would actually compile within the kernel (e.g. `alloc` used different `cfg`s).
It's great to see some KUnit support here!
It's also possible to run these tests using the KUnit wrapper tool with: $ ./tools/testing/kunit/kunit.py run --kconfig_add CONFIG_RUST=y --make_options LLVM=1 --arch x86_64 'rust_kernel_doctests'
That also nicely formats the results.
(It obviously doesn't run under UML yet, though I did get it to work after indiscriminately hacking out everything that wasn't supported. Assuming we can hide the irq and iomem stuff behind the appropriate config options, and rework some of the architecture detection to either support SUBARCH or check for X86_64 instead of X86, it should be pretty easy to get going.)
That all being said, I can't say I'm thrilled with the test names here: none of them are particularly descriptive, and they'll probably not be static (which would make it difficult to track results / regressions / etc between kernel versions). Neither of those are necessarily deal breakers, though it might make sense to hide them behind a kernel option (like all other KUnit tests) so that they can easily be excluded where they would otherwise clutter up results. (And if there's a way to properly name them, or maybe even split them into per-file or per-module suites, that would make them a bit easier to deal.) Additionally, there are some plans to taint the kernel[1] when KUnit tests run, so having a way to turn them off would be very useful.
Regardless, this is very neat, and I'm looking forward to taking a closer look at it.
Cheers, -- David
[1]: https://lore.kernel.org/linux-kselftest/20220429043913.626647-1-davidgow@goo...
Hi David,
On Sat, May 7, 2022 at 11:29 AM David Gow davidgow@google.com wrote:
It's great to see some KUnit support here!
Thanks!
It's also possible to run these tests using the KUnit wrapper tool with: $ ./tools/testing/kunit/kunit.py run --kconfig_add CONFIG_RUST=y --make_options LLVM=1 --arch x86_64 'rust_kernel_doctests'
That also nicely formats the results.
Indeed!
[16:55:52] ============ rust_kernel_doctests (70 subtests) ============ [16:55:52] [PASSED] rust_kernel_doctest_build_assert_rs_12_0 [16:55:52] [PASSED] rust_kernel_doctest_build_assert_rs_55_0 ... [16:55:52] [PASSED] rust_kernel_doctest_types_rs_445_0 [16:55:52] [PASSED] rust_kernel_doctest_types_rs_509_0 [16:55:52] ============== [PASSED] rust_kernel_doctests =============== [16:55:52] ============================================================ [16:55:52] Testing complete. Passed: 70, Failed: 0, Crashed: 0, Skipped: 0, Errors: 0
That all being said, I can't say I'm thrilled with the test names here: none of them are particularly descriptive, and they'll probably not be static (which would make it difficult to track results / regressions / etc between kernel versions). Neither of those are
Yeah, the names are not great and would change from time to time across kernel versions.
We could ask example writers to give each example a name, but that would make them fairly less convenient. For instance, sometimes they may be very small snippets interleaved with docs' prose (where giving a name may feel a bit of a burden, and people may end writing `foo_example1`, `foo_example2` etc. for each small "step" of an explanation). In other cases they may be very long, testing a wide API surface (e.g. when describing a module or type), where it is also hard to give non-generic names like `rbtree_doctest`. In those kind of cases, I think we would end up with not much better names than automatically generated ones.
The other aspect is that, given they are part of the documentation, the prose or how things are explained/split may change, thus the doctests as well. For instance, one may need to split a very long `rbtree_doctest` in pieces, and then the name would need to change anyway.
So I think we should avoid asking documentation writers to add a manual name, even if that means a bit ugly test names. Also this way they are consistently named. What do you think?
One idea could be giving them a name based on the hash of the content and avoiding the line number, so that there is a higher chance for the name to stay the same even when the file gets modified for other reasons.
necessarily deal breakers, though it might make sense to hide them behind a kernel option (like all other KUnit tests) so that they can easily be excluded where they would otherwise clutter up results. (And
Currently they are under `CONFIG_RUST_KERNEL_KUNIT_TEST` -- or do you mean something else?
if there's a way to properly name them, or maybe even split them into per-file or per-module suites, that would make them a bit easier to deal.) Additionally, there are some plans to taint the kernel[1] when
Yeah, splitting them further is definitely possible. We are also likely splitting the `kernel` crate into several, which would also make the suites smaller etc. so perhaps further splits may not be needed.
Regardless, this is very neat, and I'm looking forward to taking a closer look at it.
Thanks again for taking a look and playing with it, I am glad you liked it! (even if it is just a first approximation, and only supports the `kernel` crate, etc.).
Cheers, Miguel
On Sat, May 7, 2022 at 11:03 PM Miguel Ojeda miguel.ojeda.sandonis@gmail.com wrote:
Hi David,
On Sat, May 7, 2022 at 11:29 AM David Gow davidgow@google.com wrote:
It's great to see some KUnit support here!
Thanks!
It's also possible to run these tests using the KUnit wrapper tool with: $ ./tools/testing/kunit/kunit.py run --kconfig_add CONFIG_RUST=y --make_options LLVM=1 --arch x86_64 'rust_kernel_doctests'
That also nicely formats the results.
Indeed!
[16:55:52] ============ rust_kernel_doctests (70 subtests) ============ [16:55:52] [PASSED] rust_kernel_doctest_build_assert_rs_12_0 [16:55:52] [PASSED] rust_kernel_doctest_build_assert_rs_55_0 ... [16:55:52] [PASSED] rust_kernel_doctest_types_rs_445_0 [16:55:52] [PASSED] rust_kernel_doctest_types_rs_509_0 [16:55:52] ============== [PASSED] rust_kernel_doctests =============== [16:55:52] ============================================================ [16:55:52] Testing complete. Passed: 70, Failed: 0, Crashed: 0, Skipped: 0, Errors: 0
I've just sent out a pull request to get this working under UML as well, which would simplify running these further: https://github.com/Rust-for-Linux/linux/pull/766
That all being said, I can't say I'm thrilled with the test names here: none of them are particularly descriptive, and they'll probably not be static (which would make it difficult to track results / regressions / etc between kernel versions). Neither of those are
Yeah, the names are not great and would change from time to time across kernel versions.
We could ask example writers to give each example a name, but that would make them fairly less convenient. For instance, sometimes they may be very small snippets interleaved with docs' prose (where giving a name may feel a bit of a burden, and people may end writing `foo_example1`, `foo_example2` etc. for each small "step" of an explanation). In other cases they may be very long, testing a wide API surface (e.g. when describing a module or type), where it is also hard to give non-generic names like `rbtree_doctest`. In those kind of cases, I think we would end up with not much better names than automatically generated ones.
The other aspect is that, given they are part of the documentation, the prose or how things are explained/split may change, thus the doctests as well. For instance, one may need to split a very long `rbtree_doctest` in pieces, and then the name would need to change anyway.
So I think we should avoid asking documentation writers to add a manual name, even if that means a bit ugly test names. Also this way they are consistently named. What do you think?
Yeah, these are all fair points: particularly for small doctests.
Maybe having an optional name, which more significant tests could use to override the file:line names? That could be useful for a few of the larger, more often referenced tests.
One idea could be giving them a name based on the hash of the content and avoiding the line number, so that there is a higher chance for the name to stay the same even when the file gets modified for other reasons.
Ugh: it's a bit ugly either way. I suspect that file:line is still probably better, if only because we need some way of looking up the test in the code if it fails. I'd hate for people to be randomly hashing bits of just to find out what test is failing.
necessarily deal breakers, though it might make sense to hide them behind a kernel option (like all other KUnit tests) so that they can easily be excluded where they would otherwise clutter up results. (And
Currently they are under `CONFIG_RUST_KERNEL_KUNIT_TEST` -- or do you mean something else?
Oops: I missed that (one of the issues with testing this on a different machine which had a rust toolchain). Looks good to me.
if there's a way to properly name them, or maybe even split them into per-file or per-module suites, that would make them a bit easier to deal.) Additionally, there are some plans to taint the kernel[1] when
Yeah, splitting them further is definitely possible. We are also likely splitting the `kernel` crate into several, which would also make the suites smaller etc. so perhaps further splits may not be needed.
Ah: I didn't realise the plan was always to have crate-specific suites, and possibly to split things up.
The KTAP output specification does actually support arbitrary nesting (though KUnit itself doesn't at the moment), which would potentially be an option if (e.g.) providing the complete module nesting made sense. I'm not convinced that'd make things easier to read, though.
Regardless, this is very neat, and I'm looking forward to taking a closer look at it.
Thanks again for taking a look and playing with it, I am glad you liked it! (even if it is just a first approximation, and only supports the `kernel` crate, etc.).
Cheers, Miguel
Thanks, -- David
Hi David,
On Tue, May 10, 2022 at 6:45 AM David Gow davidgow@google.com wrote:
I've just sent out a pull request to get this working under UML as well, which would simplify running these further: https://github.com/Rust-for-Linux/linux/pull/766
Thanks a lot!
Yeah, these are all fair points: particularly for small doctests.
Maybe having an optional name, which more significant tests could use to override the file:line names? That could be useful for a few of the larger, more often referenced tests.
Sounds reasonable. I can add support for that.
Ugh: it's a bit ugly either way. I suspect that file:line is still probably better, if only because we need some way of looking up the test in the code if it fails. I'd hate for people to be randomly hashing bits of just to find out what test is failing.
One redeeming quality is that the assertion prints the line/file number in the generated file, so it would still be possible to check where it came from:
[13:13:43] # rust_kernel_doctest_str_rs_somehash: ASSERTION FAILED at rust/doctests_kernel_generated.rs:2209 [13:13:43] Expected 2 > 3 to be true, but is false [13:13:43] not ok 43 - rust_kernel_doctest_str_rs_somehash [13:13:43] [FAILED] rust_kernel_doctest_str_rs_somehash
Another alternative is to keep the file:line information around without embedding it into the test name, e.g. in a TAP comment or a mapping file (which `kunit.py` could read).
But, yeah, before doing hashes or things like that, I would just go for simplicity and keep things as they are unless some use case really needs doctests to be stable.
Oops: I missed that (one of the issues with testing this on a different machine which had a rust toolchain). Looks good to me.
Ah: I didn't realise the plan was always to have crate-specific suites, and possibly to split things up.
The KTAP output specification does actually support arbitrary nesting (though KUnit itself doesn't at the moment), which would potentially be an option if (e.g.) providing the complete module nesting made sense. I'm not convinced that'd make things easier to read, though.
That is useful to know in case we need it, thanks!
Cheers, Miguel
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Miguel Ojeda -
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