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2026-04-07docs: rust: general-information: use real exampleMiguel Ojeda1-2/+2
Currently the example in the documentation shows a version-based name for the Kconfig example: RUSTC_VERSION_MIN_107900 The reason behind it was to possibly avoid repetition in case several features used the same minimum. However, we ended up preferring to give them a descriptive name for each feature added even if that could lead to some repetition. In practice, the repetition has not happened so far, and even if it does at some point, it is not a big deal. Thus replace the example in the documentation with one of our current examples (after removing previous ones from the bump), to show how they actually look like, and in case someone `grep`s for it. In addition, it has the advantage that it shows the `RUSTC_HAS_*` pattern we follow in `init/Kconfig`, similar to the C side. Reviewed-by: Tamir Duberstein <tamird@kernel.org> Reviewed-by: Gary Guo <gary@garyguo.net> Link: https://patch.msgid.link/20260405235309.418950-31-ojeda@kernel.org Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2026-04-07docs: rust: general-information: simplify Kconfig exampleMiguel Ojeda1-1/+1
There is no need to use `def_bool y if <expr>` -- one can simply write `def_bool <expr>`. In fact, the simpler form is how we actually use them in practice in `init/Kconfig`. Thus simplify the example. Reviewed-by: Tamir Duberstein <tamird@kernel.org> Reviewed-by: Gary Guo <gary@garyguo.net> Link: https://patch.msgid.link/20260405235309.418950-30-ojeda@kernel.org Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2026-04-07docs: rust: quick-start: remove GDB/Binutils mentionMiguel Ojeda1-9/+0
The versions provided nowadays by even a distribution like Debian Stable (and Debian Old Stable) are newer than those mentioned [1]. Thus remove the workaround. Note that the minimum binutils version in the kernel is still 2.30, so one could argue part of the note is still relevant, but it is unlikely a kernel developer using such an old binutils is enabling Rust on a modern kernel, especially when using distribution toolchains, e.g. the Rust minimum version is not satisfied by Debian Old Stable. So we are at the point where keeping the docs short and relevant for essentially everyone is probably the better trade-off. Link: https://packages.debian.org/search?suite=all&searchon=names&keywords=binutils [1] Link: https://lore.kernel.org/all/CANiq72mCpc9=2TN_zC4NeDMpFQtPXAFvyiP+gRApg2vzspPWmw@mail.gmail.com/ Reviewed-by: Tamir Duberstein <tamird@kernel.org> Reviewed-by: Gary Guo <gary@garyguo.net> Link: https://patch.msgid.link/20260405235309.418950-29-ojeda@kernel.org Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2026-04-07docs: rust: quick-start: remove Nix "unstable channel" noteMiguel Ojeda1-2/+2
Nix does not need the "unstable channel" note, since its packages are recent enough even in the stable channel [1][2]. Thus remove it to simplify the documentation. Link: https://search.nixos.org/packages?channel=25.11&query=rust [1] Link: https://search.nixos.org/packages?channel=25.11&query=bindgen [2] Reviewed-by: Tamir Duberstein <tamird@kernel.org> Reviewed-by: Gary Guo <gary@garyguo.net> Link: https://patch.msgid.link/20260405235309.418950-28-ojeda@kernel.org Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2026-04-07docs: rust: quick-start: remove Gentoo "testing" noteMiguel Ojeda1-2/+2
Gentoo does not need the "testing" note, since its packages are recent enough even in the stable branch [1][2]. Thus remove it to simplify the documentation. Link: https://packages.gentoo.org/packages/dev-lang/rust [1] Link: https://packages.gentoo.org/packages/dev-util/bindgen [2] Reviewed-by: Tamir Duberstein <tamird@kernel.org> Link: https://patch.msgid.link/20260405235309.418950-27-ojeda@kernel.org Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2026-04-07docs: rust: quick-start: add Ubuntu 26.04 LTS and remove subsection titleMiguel Ojeda1-4/+1
Ubuntu 26.04 LTS (Resolute Raccoon) is scheduled to be released in a few weeks [1], and it has a recent enough Rust toolchain, just like Ubuntu 25.10 has [2][3]. We could update the title and the paragraph, but to simplify and to make it more consistent with the other distributions' sections, let's instead just remove that title. It will also reduce the differences later on to keep it updated. Eventually, when we remove the remaining subsection for older LTSs, Ubuntu should be a small section like the other distributions. Thus remove the title and add the mention of Ubuntu 26.04 LTS. Link: https://documentation.ubuntu.com/release-notes/26.04/schedule/#resolute-raccoon-schedule [1] Link: https://packages.ubuntu.com/search?keywords=rustc&searchon=names&exact=1&suite=all&section=all [2] Link: https://packages.ubuntu.com/search?keywords=bindgen&searchon=names&exact=1&suite=all&section=all [3] Reviewed-by: Tamir Duberstein <tamird@kernel.org> Link: https://patch.msgid.link/20260405235309.418950-26-ojeda@kernel.org Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2026-04-07docs: rust: quick-start: update minimum Ubuntu versionMiguel Ojeda1-1/+1
Ubuntu 25.04 is out of support [1], and Ubuntu 25.10 is the latest supported one. Moreover, Ubuntu 25.10 is the first that provides a recent enough Rust given the minimum bump -- they provide 1.85.1 [2]. Thus update it. Link: https://ubuntu.com/about/release-cycle [1] Link: https://packages.ubuntu.com/search?keywords=rustc&searchon=names&exact=1&suite=all&section=all [2] Reviewed-by: Tamir Duberstein <tamird@kernel.org> Link: https://patch.msgid.link/20260405235309.418950-25-ojeda@kernel.org Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2026-04-07docs: rust: quick-start: update Ubuntu versioned packagesMiguel Ojeda1-14/+14
Now that the minimum supported Rust version is bumped, bump the versioned Rust packages [1][2][3][4] to that version for Ubuntu in the Quick Start guide. In addition, add "may" to the `RUST_LIB_SRC` line since it does not look like it is needed from a quick test in a Ubuntu 24.04 LTS container. Link: https://packages.ubuntu.com/search?suite=all&searchon=names&keywords=rustc [1] Link: https://packages.ubuntu.com/search?suite=all&searchon=names&keywords=bindgen [2] Link: https://launchpad.net/ubuntu/+source/rustc-1.85 [3] Link: https://launchpad.net/ubuntu/+source/rust-bindgen-0.71 [4] Reviewed-by: Tamir Duberstein <tamird@kernel.org> Link: https://patch.msgid.link/20260405235309.418950-24-ojeda@kernel.org Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2026-04-07docs: rust: quick-start: openSUSE provides `rust-src` package nowadaysMiguel Ojeda1-1/+1
Both openSUSE Tumbleweed and Slowroll provide the `rust-src` package nowadays [1]. Thus remove the version-specific one from the Quick Start guide. Link: https://software.opensuse.org/package/rust-src?search_term=rust-src [1] Reviewed-by: Tamir Duberstein <tamird@kernel.org> Link: https://patch.msgid.link/20260405235309.418950-23-ojeda@kernel.org Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2026-02-10Merge tag 'rust-6.20-7.0' of ↵Linus Torvalds1-18/+0
git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux Pull rust updates from Miguel Ojeda: "Toolchain and infrastructure: - Add '__rust_helper' annotation to the C helpers This is needed to inline these helpers into Rust code - Remove imports available via the prelude, treewide This was possible thanks to a new lint in Klint that Gary has implemented -- more Klint-related changes, including initial upstream support, are coming - Deduplicate pin-init flags 'kernel' crate: - Add support for calling a function exactly once with the new 'do_once_lite!' macro (and 'OnceLite' type) Based on this, add 'pr_*_once!' macros to print only once - Add 'impl_flags!' macro for defining common bitflags operations: impl_flags!( /// Represents multiple permissions. #[derive(Debug, Clone, Default, Copy, PartialEq, Eq)] pub struct Permissions(u32); /// Represents a single permission. #[derive(Debug, Clone, Copy, PartialEq, Eq)] pub enum Permission { /// Read permission. Read = 1 << 0, /// Write permission. Write = 1 << 1, /// Execute permission. Execute = 1 << 2, } ); let mut f: Permissions = Permission::Read | Permission::Write; assert!(f.contains(Permission::Read)); assert!(!f.contains(Permission::Execute)); f |= Permission::Execute; assert!(f.contains(Permission::Execute)); let f2: Permissions = Permission::Write | Permission::Execute; assert!((f ^ f2).contains(Permission::Read)); assert!(!(f ^ f2).contains(Permission::Write)); - 'bug' module: support 'CONFIG_DEBUG_BUGVERBOSE_DETAILED' in the 'warn_on!' macro in order to show the evaluated condition alongside the file path: ------------[ cut here ]------------ WARNING: [val == 1] linux/samples/rust/rust_minimal.rs:27 at ... Modules linked in: rust_minimal(+) - Add safety module with 'unsafe_precondition_assert!' macro, currently a wrapper for 'debug_assert!', intended to mark the validation of safety preconditions where possible: /// # Safety /// /// The caller must ensure that `index` is less than `N`. unsafe fn set_unchecked(&mut self, index: usize, value: T) { unsafe_precondition_assert!( index < N, "set_unchecked() requires index ({index}) < N ({N})" ); ... } - Add instructions to 'build_assert!' documentation requesting to always inline functions when used with function arguments - 'ptr' module: replace 'build_assert!' with a 'const' one - 'rbtree' module: reduce unsafe blocks on pointer derefs - 'transmute' module: implement 'FromBytes' and 'AsBytes' for inhabited ZSTs, and use it in Nova - More treewide replacements of 'c_str!' with C string literals 'macros' crate: - Rewrite most procedural macros ('module!', 'concat_idents!', '#[export]', '#[vtable]', '#[kunit_tests]') to use the 'syn' parsing library which we introduced last cycle, with better diagnostics This also allows to support '#[cfg]' properly in the '#[vtable]' macro, to support arbitrary types in 'module!' macro (not just an identifier) and to remove several custom parsing helpers we had - Use 'quote!' from the recently vendored 'quote' library and remove our custom one The vendored one also allows us to avoid quoting '"' and '{}' inside the template anymore and editors can now highlight it. In addition, it improves robustness as it eliminates the need for string quoting and escaping - Use 'pin_init::zeroed()' to simplify KUnit code 'pin-init' crate: - Rewrite all procedural macros ('[pin_]init!', '#[pin_data]', '#[pinned_drop]', 'derive([Maybe]Zeroable)') to use the 'syn' parsing library which we introduced last cycle, with better diagnostics - Implement 'InPlaceWrite' for '&'static mut MaybeUninit<T>'. This enables users to use external allocation mechanisms such as 'static_cell' - Support tuple structs in 'derive([Maybe]Zeroable)' - Support attributes on fields in '[pin_]init!' (such as '#[cfg(...)]') - Add a '#[default_error(<type>)]' attribute to '[pin_]init!' to override the default error (when no '? Error' is specified) - Support packed structs in '[pin_]init!' with '#[disable_initialized_field_access]' - Remove 'try_[pin_]init!' in favor of merging their feature with '[pin_]init!'. Update the kernel's own 'try_[pin_]init!' macros to use the 'default_error' attribute - Correct 'T: Sized' bounds to 'T: ?Sized' in the generated 'PinnedDrop' check by '#[pin_data]' Documentation: - Conclude the Rust experiment MAINTAINERS: - Add "RUST [RUST-ANALYZER]" entry for the rust-analyzer support. Tamir and Jesung will take care of it. They have both been active around it for a while. The new tree will flow through the Rust one - Add Gary as maintainer for "RUST [PIN-INIT]" - Update Boqun and Tamir emails to their kernel.org accounts And a few other cleanups and improvements" * tag 'rust-6.20-7.0' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux: (59 commits) rust: safety: introduce `unsafe_precondition_assert!` macro rust: add `impl_flags!` macro for defining common bitflag operations rust: print: Add pr_*_once macros rust: bug: Support DEBUG_BUGVERBOSE_DETAILED option rust: print: Add support for calling a function exactly once rust: kbuild: deduplicate pin-init flags gpu: nova-core: remove imports available via prelude rust: clk: replace `kernel::c_str!` with C-Strings MAINTAINERS: Update my email address to @kernel.org rust: macros: support `#[cfg]` properly in `#[vtable]` macro. rust: kunit: use `pin_init::zeroed` instead of custom null value rust: macros: rearrange `#[doc(hidden)]` in `module!` macro rust: macros: allow arbitrary types to be used in `module!` macro rust: macros: convert `#[kunit_tests]` macro to use `syn` rust: macros: convert `concat_idents!` to use `syn` rust: macros: convert `#[export]` to use `syn` rust: macros: use `quote!` for `module!` macro rust: macros: use `syn` to parse `module!` macro rust: macros: convert `#[vtable]` macro to use `syn` rust: macros: use `quote!` from vendored crate ...
2026-01-23Documentation: use a source-read extension for the index link boilerplateJani Nikula1-7/+0
The root document usually has a special :ref:`genindex` link to the generated index. This is also the case for Documentation/index.rst. The other index.rst files deeper in the directory hierarchy usually don't. For SPHINXDIRS builds, the root document isn't Documentation/index.rst, but some other index.rst in the hierarchy. Currently they have a ".. only::" block to add the index link when doing SPHINXDIRS html builds. This is obviously very tedious and repetitive. The link is also added to all index.rst files in the hierarchy for SPHINXDIRS builds, not just the root document. Put the boilerplate in a sphinx-includes/subproject-index.rst file, and include it at the end of the root document for subproject builds in an ad-hoc source-read extension defined in conf.py. For now, keep having the boilerplate in translations, because this approach currently doesn't cover translated index link headers. Cc: Jonathan Corbet <corbet@lwn.net> Cc: Mauro Carvalho Chehab <mchehab@kernel.org> Cc: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Jani Nikula <jani.nikula@intel.com> Tested-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Reviewed-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> [jc: did s/doctree/kern_doc_dir/ ] Signed-off-by: Jonathan Corbet <corbet@lwn.net> Message-ID: <20260123143149.2024303-1-jani.nikula@intel.com>
2026-01-19rust: conclude the Rust experimentMiguel Ojeda1-18/+0
The Rust support was merged in v6.1 into mainline in order to help determine whether Rust as a language was suitable for the kernel, i.e. worth the tradeoffs, technically, procedurally and socially. At the 2025 Linux Kernel Maintainers Summit, the experiment has just been deemed concluded [1]. Thus remove the section -- it was not fully true already anyway, since there are already uses of Rust in production out there, some well-known Linux distributions enable it and it is already in millions of devices via Android. Obviously, this does not mean that everything works for every kernel configuration, architecture, toolchain etc., or that there won't be new issues. There is still a ton of work to do in all areas, from the kernel to upstream Rust, GCC and other projects. And, in fact, certain combinations (such as the mixed GCC+LLVM builds and the upcoming GCC support) are still quite experimental but getting there. But the experiment is done, i.e. Rust is here to stay. I hope this signals commitment from the kernel to companies and other entities to invest more into it, e.g. into giving time to their kernel developers to train themselves in Rust. Thanks to the many kernel maintainers that gave the project their support and patience throughout these years, and to the many other developers, whether in the kernel or in other projects, that have made this possible. I had a long list of 173 names in the credits of the original pull that merged the support into the kernel [2], and now such a list would be way longer, so I will not even try to compose one, but again, thanks a lot, everybody. Link: https://lwn.net/Articles/1050174/ [1] Link: https://git.kernel.org/linus/8aebac82933f [2] Reviewed-by: Gary Guo <gary@garyguo.net> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Benno Lossin <lossin@kernel.org> Acked-by: Andreas Hindborg <a.hindborg@kernel.org> Acked-by: Danilo Krummrich <dakr@kernel.org> Reviewed-by: Boqun Feng <boqun.feng@gmail.com> Link: https://patch.msgid.link/20251213000042.23072-1-ojeda@kernel.org Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-11-04docs: rust: quick-start: add Debian 13 (Trixie)Miguel Ojeda1-2/+2
Debian 13 (released 2025-08-09) packages Rust 1.85.0 [1], which is recent enough to build Linux. Thus document it. In fact, we are planning to propose that the minimum supported Rust version in Linux follows Debian Stable releases, with Debian 13 being the first one we upgrade to, i.e. Rust 1.85. Link: https://www.debian.org/News/2025/20250809 [1] Link: https://patch.msgid.link/20251012224645.1148411-1-ojeda@kernel.org Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-10-17docs: rust: add section on imports formattingMiguel Ojeda1-0/+75
`rustfmt`, by default, formats imports in a way that is prone to conflicts while merging and rebasing, since in some cases it condenses several items into the same line. For instance, Linus mentioned [1] that the following case: use crate::{ fmt, page::AsPageIter, }; is compressed by `rustfmt` into: use crate::{fmt, page::AsPageIter}; which is undesirable. Similarly, `rustfmt` may put several items in the same line even if the braces span already multiple lines, e.g.: use kernel::{ acpi, c_str, device::{property, Core}, of, platform, }; The options that control the formatting behavior around imports are generally unstable, and `rustfmt` releases do not allow to use nightly features, unlike the compiler and other Rust tooling [2]. For the moment, we can introduce a workaround to prevent `rustfmt` from compressing the example above -- the "trailing empty comment": use crate::{ fmt, page::AsPageIter, // }; which is reminiscent of the trailing comma behavior in other formatters. We already used empty comments for formatting purposes in the past, e.g. in commit b9b701fce49a ("rust: clarify the language unstable features in use"). In addition, `rustfmt` actually reformats with a vertical layout (i.e. it does not put two items in the same line) when seeing such a comment, i.e. it doesn't just preserve the formatting, which is good in the sense that we can use it to easily reformat some imports, since it matches the style we generally want to have. A Git merge driver would help (suggested by Gary and Wedson), though maintainers would need to set it up, the diffs would still be larger and the formatting rules for imports would remain hard to predict. Thus document the style that we will follow in the coding guidelines by introducing a new section and explain how the trailing empty comment works there too. We discussed the issue with upstream Rust in our usual Rust <-> Rust for Linux meeting [3], and there have also been a few other discussions in parallel in issues [4][5] and Zulip [6]. We will see what happens, but upstream Rust has already created a subteam of `rustfmt` to try to overcome the bandwidth issue [7], which is a good signal, and some organization work has already started (e.g. tracking issues). We will continue our discussions with them about it. Cc: Caleb Cartwright <caleb.cartwright@outlook.com> Cc: Yacin Tmimi <yacintmimi@gmail.com> Cc: Manish Goregaokar <manishsmail@gmail.com> Cc: Deadbeef <ent3rm4n@gmail.com> Cc: Cameron Steffen <cam.steffen94@gmail.com> Cc: Jieyou Xu <jieyouxu@outlook.com> Link: https://lore.kernel.org/all/CAHk-=wgO7S_FZUSBbngG5vtejWOpzDfTTBkVvP3_yjJmFddbzA@mail.gmail.com/ [1] Link: https://github.com/rust-lang/rustfmt/issues/4884 [2] Link: https://hackmd.io/iSCyY3JTTz-g8YM-nnzTTA [3] Link: https://github.com/rust-lang/rustfmt/issues/4991 [4] Link: https://github.com/rust-lang/rustfmt/issues/3361 [5] Link: https://rust-lang.zulipchat.com/#narrow/channel/392734-council/topic/rustfmt.20maintenance/near/543815381 [6] Link: https://github.com/rust-lang/team/pull/2017 [7] Reviewed-by: Benno Lossin <lossin@kernel.org> Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-05-27Documentation: rust: testing: add docs on the new KUnit `#[test]` testsMiguel Ojeda1-0/+71
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>
2025-05-27Documentation: rust: rename `#[test]`s to "`rusttest` host tests"Miguel Ojeda1-6/+7
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>
2025-05-23rust: add C FFI types to the preludeMiguel Ojeda1-0/+17
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>
2025-05-23docs: rust: quick-start: update Ubuntu instructionsIgor Korotin1-3/+41
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>
2025-05-12docs: rust: explain that `///` vs. `//` applies to private items tooMiguel Ojeda1-0/+12
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>
2025-04-03Merge tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rmk/linuxLinus Torvalds1-0/+1
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
2025-03-30Merge tag 'rust-6.15' of ↵Linus Torvalds2-0/+15
git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux 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` ...
2025-03-26ARM: 9441/1: rust: Enable Rust support for ARMv7Christian Schrrefl1-0/+1
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>
2025-03-08docs: rust: Add error handling sectionsDirk Behme2-0/+15
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>
2025-03-06rust: docs: add missing newline to printing macro examplesAlban Kurti1-1/+1
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>
2025-03-05rust: remove leftover mentions of the `alloc` crateMiguel Ojeda1-1/+1
In commit 392e34b6bc22 ("kbuild: rust: remove the `alloc` crate and `GlobalAlloc`") we stopped using the upstream `alloc` crate. Thus remove a few leftover mentions treewide. Cc: stable@vger.kernel.org # Also to 6.12.y after the `alloc` backport lands Fixes: 392e34b6bc22 ("kbuild: rust: remove the `alloc` crate and `GlobalAlloc`") Reviewed-by: Danilo Krummrich <dakr@kernel.org> Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org> Link: https://lore.kernel.org/r/20250303171030.1081134-1-ojeda@kernel.org Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-11-26Merge tag 'rust-6.13' of https://github.com/Rust-for-Linux/linuxLinus Torvalds2-0/+163
Pull rust updates from Miguel Ojeda: "Toolchain and infrastructure: - Enable a series of lints, including safety-related ones, e.g. the compiler will now warn about missing safety comments, as well as unnecessary ones. How safety documentation is organized is a frequent source of review comments, thus having the compiler guide new developers on where they are expected (and where not) is very nice. - Start using '#[expect]': an interesting feature in Rust (stabilized in 1.81.0) that makes the compiler warn if an expected warning was _not_ emitted. This is useful to avoid forgetting cleaning up locally ignored diagnostics ('#[allow]'s). - Introduce '.clippy.toml' configuration file for Clippy, the Rust linter, which will allow us to tweak its behaviour. For instance, our first use cases are declaring a disallowed macro and, more importantly, enabling the checking of private items. - Lints-related fixes and cleanups related to the items above. - Migrate from 'receiver_trait' to 'arbitrary_self_types': to get the kernel into stable Rust, one of the major pieces of the puzzle is the support to write custom types that can be used as 'self', i.e. as receivers, since the kernel needs to write types such as 'Arc' that common userspace Rust would not. 'arbitrary_self_types' has been accepted to become stable, and this is one of the steps required to get there. - Remove usage of the 'new_uninit' unstable feature. - Use custom C FFI types. Includes a new 'ffi' crate to contain our custom mapping, instead of using the standard library 'core::ffi' one. The actual remapping will be introduced in a later cycle. - Map '__kernel_{size_t,ssize_t,ptrdiff_t}' to 'usize'/'isize' instead of 32/64-bit integers. - Fix 'size_t' in bindgen generated prototypes of C builtins. - Warn on bindgen < 0.69.5 and libclang >= 19.1 due to a double issue in the projects, which we managed to trigger with the upcoming tracepoint support. It includes a build test since some distributions backported the fix (e.g. Debian -- thanks!). All major distributions we list should be now OK except Ubuntu non-LTS. 'macros' crate: - Adapt the build system to be able run the doctests there too; and clean up and enable the corresponding doctests. 'kernel' crate: - Add 'alloc' module with generic kernel allocator support and remove the dependency on the Rust standard library 'alloc' and the extension traits we used to provide fallible methods with flags. Add the 'Allocator' trait and its implementations '{K,V,KV}malloc'. Add the 'Box' type (a heap allocation for a single value of type 'T' that is also generic over an allocator and considers the kernel's GFP flags) and its shorthand aliases '{K,V,KV}Box'. Add 'ArrayLayout' type. Add 'Vec' (a contiguous growable array type) and its shorthand aliases '{K,V,KV}Vec', including iterator support. For instance, now we may write code such as: let mut v = KVec::new(); v.push(1, GFP_KERNEL)?; assert_eq!(&v, &[1]); Treewide, move as well old users to these new types. - 'sync' module: add global lock support, including the 'GlobalLockBackend' trait; the 'Global{Lock,Guard,LockedBy}' types and the 'global_lock!' macro. Add the 'Lock::try_lock' method. - 'error' module: optimize 'Error' type to use 'NonZeroI32' and make conversion functions public. - 'page' module: add 'page_align' function. - Add 'transmute' module with the existing 'FromBytes' and 'AsBytes' traits. - 'block::mq::request' module: improve rendered documentation. - 'types' module: extend 'Opaque' type documentation and add simple examples for the 'Either' types. drm/panic: - Clean up a series of Clippy warnings. Documentation: - Add coding guidelines for lints and the '#[expect]' feature. - Add Ubuntu to the list of distributions in the Quick Start guide. MAINTAINERS: - Add Danilo Krummrich as maintainer of the new 'alloc' module. And a few other small cleanups and fixes" * tag 'rust-6.13' of https://github.com/Rust-for-Linux/linux: (82 commits) rust: alloc: Fix `ArrayLayout` allocations docs: rust: remove spurious item in `expect` list rust: allow `clippy::needless_lifetimes` rust: warn on bindgen < 0.69.5 and libclang >= 19.1 rust: use custom FFI integer types rust: map `__kernel_size_t` and friends also to usize/isize rust: fix size_t in bindgen prototypes of C builtins rust: sync: add global lock support rust: macros: enable the rest of the tests rust: macros: enable paste! use from macro_rules! rust: enable macros::module! tests rust: kbuild: expand rusttest target for macros rust: types: extend `Opaque` documentation rust: block: fix formatting of `kernel::block::mq::request` module rust: macros: fix documentation of the paste! macro rust: kernel: fix THIS_MODULE header path in ThisModule doc comment rust: page: add Rust version of PAGE_ALIGN rust: helpers: remove unnecessary header includes rust: exports: improve grammar in commentary drm/panic: allow verbose version check ...
2024-11-25docs: rust: remove spurious item in `expect` listMiguel Ojeda1-3/+1
This list started as a "when to prefer `expect`" list, but at some point during writing I changed it to a "prefer `expect` unless..." one. However, the first bullet remained, which does not make sense anymore. Thus remove it. In addition, fix nearby typo. Fixes: 04866494e936 ("Documentation: rust: discuss `#[expect(...)]` in the guidelines") Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org> Link: https://lore.kernel.org/r/20241117133127.473937-1-ojeda@kernel.org Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-11-20Merge tag 'docs-6.13' of git://git.lwn.net/linuxLinus Torvalds1-0/+3
Pull documentation updates from Jonathan Corbet: "Another moderately busy cycle in docsland: - Work on Chinese translations has picked up again. Happily, they are maintaining the existing translations and not just adding new ones. - Some maintenance of the Japanese and Italian translations as well. - The removal of the venerable "dontdiff" file. It has long outlived its usefulness and contained entries ("parse.*") that would actively mask actual source change. - The addition of enforcement information to the code-of-conduct documentation. Along with some build-system fixes and a lot of typo and language fixes" * tag 'docs-6.13' of git://git.lwn.net/linux: (52 commits) Documentation/CoC: spell out enforcement for unacceptable behaviors docs: fix typos and whitespace in Documentation/process/backporting.rst docs/zh_CN: fix one sentence in llvm.rst docs: bug-bisect: add a note about bisecting -next docs/zh_CN: add the translation of kbuild/llvm.rst Documentation: Fix incorrect paths/magic in magic numbers rst Documentation/maintainer-tip: Fix typos Documentation: Improve crash_kexec_post_notifiers description Docs/zh_CN: Translate physical_memory.rst to Simplified Chinese Documentation: admin: reorganize kernel-parameters intro docs/zh_CN: update the translation of process/programming-language.rst docs/zh_CN: update the translation of mm/page_owner.rst docs/zh_CN: update the translation of mm/page_table_check.rst docs/zh_CN: update the translation of mm/overcommit-accounting.rst docs/zh_CN: update the translation of mm/admon/faq.rst docs/zh_CN: update the translation of mm/active_mm.rst docs/zh_CN: update the translation of mm/hmm.rst docs: remove Documentation/dontdiff docs/zh_CN: Add a entry in Chinese glossary Docs/zh_CN: Fix the pfn calculation error in page_tables.rst ...
2024-10-25RISC-V: disallow gcc + rust buildsConor Dooley1-1/+1
During the discussion before supporting rust on riscv, it was decided not to support gcc yet, due to differences in extension handling compared to llvm (only the version of libclang matching the c compiler is supported). Recently Jason Montleon reported [1] that building with gcc caused build issues, due to unsupported arguments being passed to libclang. After some discussion between myself and Miguel, it is better to disable gcc + rust builds to match the original intent, and subsequently support it when an appropriate set of extensions can be deduced from the version of libclang. Closes: https://lore.kernel.org/all/20240917000848.720765-2-jmontleo@redhat.com/ [1] Link: https://lore.kernel.org/all/20240926-battering-revolt-6c6a7827413e@spud/ [2] Fixes: 70a57b247251a ("RISC-V: enable building 64-bit kernels with rust support") Cc: stable@vger.kernel.org Reported-by: Jason Montleon <jmontleo@redhat.com> Signed-off-by: Conor Dooley <conor.dooley@microchip.com> Acked-by: Miguel Ojeda <ojeda@kernel.org> Reviewed-by: Nathan Chancellor <nathan@kernel.org> Link: https://lore.kernel.org/r/20241001-playlist-deceiving-16ece2f440f5@spud Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-10-14kernel-docs: Add new section for Rust learning materialsCarlos Bilbao1-0/+3
Include a new section in the Index of Further Kernel Documentation with resources to learn Rust. Reference it in the Rust index. The resources are a product of a survey among assistants to the conference Kangrejos'24. Signed-off-by: Carlos Bilbao <carlos.bilbao.osdev@gmail.com> Reviewed-by: Dirk Behme <dirk.behme@de.bosch.com> Acked-by: Miguel Ojeda <ojeda@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net> Link: https://lore.kernel.org/r/20240922160411.274949-1-carlos.bilbao.osdev@gmail.com
2024-10-07Documentation: rust: discuss `#[expect(...)]` in the guidelinesMiguel Ojeda1-0/+110
Discuss `#[expect(...)]` in the Lints sections of the coding guidelines document, which is an upcoming feature in Rust 1.81.0, and explain that it is generally to be preferred over `allow` unless there is a reason not to use it (e.g. conditional compilation being involved). Tested-by: Gary Guo <gary@garyguo.net> Reviewed-by: Gary Guo <gary@garyguo.net> Link: https://lore.kernel.org/r/20240904204347.168520-19-ojeda@kernel.org Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-10-07Documentation: rust: add coding guidelines on lintsMiguel Ojeda1-0/+38
In the C side, disabling diagnostics locally, i.e. within the source code, is rare (at least in the kernel). Sometimes warnings are manipulated via the flags at the translation unit level, but that is about it. In Rust, it is easier to change locally the "level" of lints (e.g. allowing them locally). In turn, this means it is easier to globally enable more lints that may trigger a few false positives here and there that need to be allowed locally, but that generally can spot issues or bugs. Thus document this. Reviewed-by: Trevor Gross <tmgross@umich.edu> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Tested-by: Gary Guo <gary@garyguo.net> Reviewed-by: Gary Guo <gary@garyguo.net> Link: https://lore.kernel.org/r/20240904204347.168520-17-ojeda@kernel.org Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-10-07docs: rust: quick-start: add UbuntuMiguel Ojeda1-0/+17
Ubuntu has changed their maintenance model for Rust toolchains and is now providing recent Rust releases in their releases, including both LTS and non-LTS (interim) releases. Therefore, add instructions to the Quick Start guide for Ubuntu, like it is done for the other distributions. Link: https://packages.ubuntu.com/search?keywords=rustc-1 Link: https://packages.ubuntu.com/search?keywords=bindgen-0 Cc: Zixing Liu <zixing.liu@canonical.com> Cc: William Grant <wgrant@ubuntu.com> Reviewed-by: Kees Cook <kees@kernel.org> Link: https://lore.kernel.org/r/20240925140600.275429-1-ojeda@kernel.org Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-09-25Merge tag 'rust-6.12' of https://github.com/Rust-for-Linux/linuxLinus Torvalds3-9/+40
Pull Rust updates from Miguel Ojeda: "Toolchain and infrastructure: - Support 'MITIGATION_{RETHUNK,RETPOLINE,SLS}' (which cleans up objtool warnings), teach objtool about 'noreturn' Rust symbols and mimic '___ADDRESSABLE()' for 'module_{init,exit}'. With that, we should be objtool-warning-free, so enable it to run for all Rust object files. - KASAN (no 'SW_TAGS'), KCFI and sh