There was no documentation yet on the KUnit-based `#[test]`s. Thus add it now. It includes an explanation about the `assert*!` macros being mapped to KUnit and the support for `-> Result` introduced in these series. Reviewed-by: David Gow <davidgow@google.com> Acked-by: Danilo Krummrich <dakr@kernel.org> Link: https://lore.kernel.org/r/20250502215133.1923676-8-ojeda@kernel.org Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Now that `rusttest`s are not really used much, clarify the section of the documentation that describes them. In addition, free the section name for the KUnit-based `#[test]`s that will be added afterwards. To do so, rename the section into `rusttest` host tests. Reviewed-by: David Gow <davidgow@google.com> Acked-by: Danilo Krummrich <dakr@kernel.org> Link: https://lore.kernel.org/r/20250502215133.1923676-7-ojeda@kernel.org Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Rust kernel code is supposed to use the custom mapping of C FFI types, i.e. those from the `ffi` crate, rather than the ones coming from `core`. Thus, to minimize mistakes and to simplify the code everywhere, just provide them in the `kernel` prelude and ask in the Coding Guidelines to use them directly, i.e. as a single segment path. After this lands, we can start cleaning up the existing users. Ideally, we would use something like Clippy's `disallowed-types` to prevent the use of the `core` ones, but that one sees through aliases. Link: https://lore.kernel.org/rust-for-linux/CANiq72kc4gzfieD-FjuWfELRDXXD2vLgPv4wqk3nt4pjdPQ=qg@mail.gmail.com/ Reviewed-by: Danilo Krummrich <dakr@kernel.org> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Link: https://lore.kernel.org/r/20250413005650.1745894-1-ojeda@kernel.org [ Reworded content of the documentation to focus on how to use the aliases first. - Miguel ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Split installation instructions for Ubuntu into 2 different sections: - For Ubuntu 25.04: this release provides easy-to-install Rust packages. - For Ubuntu 24.10 and below: these releases provide rust-1.80 and bindgen-0.65, which do not set their tools as defaults. The instructions for these versions have been updated to configure Rust tools properly. Signed-off-by: Igor Korotin <igor.korotin@yahoo.com> Link: https://lore.kernel.org/r/20250402160047.1827500-1-igor.korotin@yahoo.com [ Dropped 24.10 -- it is soon out of support and their `bindgen` issue (reported as issue #2086639) was never patched anyway. Removed trailing spaces. Split into subheaders. Added `rustfmt` link. Removed spurious backquotes. Reworded contents slightly. - Miguel ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Sometimes kernel developers use `//` for documenting private items, since those do not get rendered at the moment. That is reasonable, but the intention behind `///` (and `//!`) vs. `//` is to convey the distinction between documentation and other kinds of comments, such as implementation details or TODOs. It also increases consistency with the public items and thus e.g. allows to change visibility of an item with less changes involved. It is not just useful for human readers, but also tooling. For instance, we may want to eventually generate documentation for private items (perhaps as a toggle in the HTML UI). On top of that, `rustdoc` lints as usual for those, too, so we may want to do it even if we do not use the result. Thus document this explicitly. Link: https://lore.kernel.org/rust-for-linux/CANiq72n_C7exSOMe5yf-7jKKnhSCv+a9QcD=OE2B_Q2UFBL3Xg@mail.gmail.com/ Link: https://github.com/Rust-for-Linux/linux/issues/1157 Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Christian Schrefl <chrisi.schrefl@gmail.com> Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org> Link: https://lore.kernel.org/r/20250416112454.2503872-1-ojeda@kernel.org [ Fixed typo. - Miguel ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Pull ARM and clkdev updates from Russell King: - Simplify ARM_MMU_KEEP usage - Add Rust support for ARM architecture version 7 - Align IPIs reported in /proc/interrupts - require linker to support KEEP within OVERLAY - add KEEP() for ARM vectors - add __printf() attribute for clkdev functions * tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rmk/linux: ARM: 9445/1: clkdev: Mark some functions with __printf() attribute ARM: 9444/1: add KEEP() keyword to ARM_VECTORS ARM: 9443/1: Require linker to support KEEP within OVERLAY for DCE ARM: 9442/1: smp: Fix IPI alignment in /proc/interrupts ARM: 9441/1: rust: Enable Rust support for ARMv7 ARM: 9439/1: arm32: simplify ARM_MMU_KEEP usage
Pull Rust updates from Miguel Ojeda:
"Toolchain and infrastructure:
- Extract the 'pin-init' API from the 'kernel' crate and make it into
a standalone crate.
In order to do this, the contents are rearranged so that they can
easily be kept in sync with the version maintained out-of-tree that
other projects have started to use too (or plan to, like QEMU).
This will reduce the maintenance burden for Benno, who will now
have his own sub-tree, and will simplify future expected changes
like the move to use 'syn' to simplify the implementation.
- Add '#[test]'-like support based on KUnit.
We already had doctests support based on KUnit, which takes the
examples in our Rust documentation and runs them under KUnit.
Now, we are adding the beginning of the support for "normal" tests,
similar to those the '#[test]' tests in userspace Rust. For
instance:
#[kunit_tests(my_suite)]
mod tests {
#[test]
fn my_test() {
assert_eq!(1 + 1, 2);
}
}
Unlike with doctests, the 'assert*!'s do not map to the KUnit
assertion APIs yet.
- Check Rust signatures at compile time for functions called from C
by name.
In particular, introduce a new '#[export]' macro that can be placed
in the Rust function definition. It will ensure that the function
declaration on the C side matches the signature on the Rust
function:
#[export]
pub unsafe extern "C" fn my_function(a: u8, b: i32) -> usize {
// ...
}
The macro essentially forces the compiler to compare the types of
the actual Rust function and the 'bindgen'-processed C signature.
These cases are rare so far. In the future, we may consider
introducing another tool, 'cbindgen', to generate C headers
automatically. Even then, having these functions explicitly marked
may be a good idea anyway.
- Enable the 'raw_ref_op' Rust feature: it is already stable, and
allows us to use the new '&raw' syntax, avoiding a couple macros.
After everyone has migrated, we will disallow the macros.
- Pass the correct target to 'bindgen' on Usermode Linux.
- Fix 'rusttest' build in macOS.
'kernel' crate:
- New 'hrtimer' module: add support for setting up intrusive timers
without allocating when starting the timer. Add support for
'Pin<Box<_>>', 'Arc<_>', 'Pin<&_>' and 'Pin<&mut _>' as pointer
types for use with timer callbacks. Add support for setting clock
source and timer mode.
- New 'dma' module: add a simple DMA coherent allocator abstraction
and a test sample driver.
- 'list' module: make the linked list 'Cursor' point between
elements, rather than at an element, which is more convenient to us
and allows for cursors to empty lists; and document it with
examples of how to perform common operations with the provided
methods.
- 'str' module: implement a few traits for 'BStr' as well as the
'strip_prefix()' method.
- 'sync' module: add 'Arc::as_ptr'.
- 'alloc' module: add 'Box::into_pin'.
- 'error' module: extend the 'Result' documentation, including a few
examples on different ways of handling errors, a warning about
using methods that may panic, and links to external documentation.
'macros' crate:
- 'module' macro: add the 'authors' key to support multiple authors.
The original key will be kept until everyone has migrated.
Documentation:
- Add error handling sections.
MAINTAINERS:
- Add Danilo Krummrich as reviewer of the Rust "subsystem".
- Add 'RUST [PIN-INIT]' entry with Benno Lossin as maintainer. It has
its own sub-tree.
- Add sub-tree for 'RUST [ALLOC]'.
- Add 'DMA MAPPING HELPERS DEVICE DRIVER API [RUST]' entry with
Abdiel Janulgue as primary maintainer. It will go through the
sub-tree of the 'RUST [ALLOC]' entry.
- Add 'HIGH-RESOLUTION TIMERS [RUST]' entry with Andreas Hindborg as
maintainer. It has its own sub-tree.
And a few other cleanups and improvements"
* tag 'rust-6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux: (71 commits)
rust: dma: add `Send` implementation for `CoherentAllocation`
rust: macros: fix `make rusttest` build on macOS
rust: block: refactor to use `&raw mut`
rust: enable `raw_ref_op` feature
rust: uaccess: name the correct function
rust: rbtree: fix comments referring to Box instead of KBox
rust: hrtimer: add maintainer entry
rust: hrtimer: add clocksource selection through `ClockId`
rust: hrtimer: add `HrTimerMode`
rust: hrtimer: implement `HrTimerPointer` for `Pin<Box<T>>`
rust: alloc: add `Box::into_pin`
rust: hrtimer: implement `UnsafeHrTimerPointer` for `Pin<&mut T>`
rust: hrtimer: implement `UnsafeHrTimerPointer` for `Pin<&T>`
rust: hrtimer: add `hrtimer::ScopedHrTimerPointer`
rust: hrtimer: add `UnsafeHrTimerPointer`
rust: hrtimer: allow timer restart from timer handler
rust: str: implement `strip_prefix` for `BStr`
rust: str: implement `AsRef<BStr>` for `[u8]` and `BStr`
rust: str: implement `Index` for `BStr`
rust: str: implement `PartialEq` for `BStr`
...
This commit allows building ARMv7 kernels with Rust support. The rust core library expects some __eabi_... functions that are not implemented in the kernel. Those functions are some float operations and __aeabi_uldivmod. For now those are implemented with define_panicking_intrinsics!. This is based on the code by Sven Van Asbroeck from the original rust branch and inspired by the AArch version by Jamie Cunliffe. I have tested the rust samples and a custom simple MMIO module on hardware (De1SoC FPGA + Arm A9 CPU). Tested-by: Rudraksha Gupta <guptarud@gmail.com> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Acked-by: Miguel Ojeda <ojeda@kernel.org> Tested-by: Miguel Ojeda <ojeda@kernel.org> Acked-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Christian Schrefl <chrisi.schrefl@gmail.com> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Add error handling sections to the documentation and use it to link to the existing code documentation. This will allow to extend that documentation, use intra-doc links and test the examples. Suggested-by: Miguel Ojeda <ojeda@kernel.org> Link: https://lore.kernel.org/rust-for-linux/CANiq72keOdXy0LFKk9SzYWwSjiD710v=hQO4xi+5E4xNALa6cA@mail.gmail.com/ Signed-off-by: Dirk Behme <dirk.behme@de.bosch.com> Link: https://lore.kernel.org/r/20250115062552.1970768-1-dirk.behme@de.bosch.com [ Slightly tweaked wording. - Miguel ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Fix adding a newline at the end of the usage of pr_info! in the
documentation
Fixes: e3c3d34507c7 ("docs: rust: Add description of Rust documentation test as KUnit ones")
Reported-by: Miguel Ojeda <ojeda@kernel.org>
Link: https://github.com/Rust-for-Linux/linux/issues/1139
Signed-off-by: Alban Kurti <kurti@invicto.ai>
Reviewed-by: David Gow <davidgow@google.com>
Link: https://lore.kernel.org/r/20250206-printing_fix-v3-1-a85273b501ae@invicto.ai
[ Replaced Closes with Link since it fixes part of the issue. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>