kernel/linux.git/rust/macros/lib.rs, branch v7.0-rc7

Merge tag 'rust-6.20-7.0' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux

2026-02-10T19:53:01+00:00

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'. 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()]' 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 ...

rust: macros: convert `#[kunit_tests]` macro to use `syn`

2026-01-28T12:43:36+00:00

Make use of `syn` to parse the module structurally and thus improve the robustness of parsing. String interpolation is avoided by generating tokens directly using `quote!`. Reviewed-by: Tamir Duberstein Signed-off-by: Gary Guo Reviewed-by: Benno Lossin Reviewed-by: David Gow Link: https://patch.msgid.link/20260112170919.1888584-9-gary@kernel.org [ Pass C string to match commit 6c37b6841a92 ("rust: kunit: replace `kernel::c_str!` with C-Strings"). - Miguel ] Signed-off-by: Miguel Ojeda

rust: macros: convert `concat_idents!` to use `syn`

2026-01-27T23:55:25+00:00

This eliminates the need for `expect_punct` helper. Reviewed-by: Tamir Duberstein Reviewed-by: Benno Lossin Signed-off-by: Gary Guo Link: https://patch.msgid.link/20260112170919.1888584-8-gary@kernel.org Signed-off-by: Miguel Ojeda

rust: macros: convert `#[export]` to use `syn`

2026-01-27T23:55:25+00:00

This eliminates the custom `function_name` helper. Reviewed-by: Tamir Duberstein Reviewed-by: Benno Lossin Signed-off-by: Gary Guo Link: https://patch.msgid.link/20260112170919.1888584-7-gary@kernel.org Signed-off-by: Miguel Ojeda

rust: macros: use `syn` to parse `module!` macro

2026-01-27T23:55:24+00:00

With `syn` being available in the kernel, use it to parse the complex custom `module!` macro to replace existing helpers. Only parsing is changed in this commit, the code generation is untouched. This has the benefit of better error message when the macro is used incorrectly, as it can point to a concrete span on what's going wrong. For example, if a field is specified twice, previously it reads: error: proc macro panicked --> samples/rust/rust_minimal.rs:7:1 | 7 | / module! { 8 | | type: RustMinimal, 9 | | name: "rust_minimal", 10 | | author: "Rust for Linux Contributors", 11 | | description: "Rust minimal sample", 12 | | license: "GPL", 13 | | license: "GPL", 14 | | } | |_^ | = help: message: Duplicated key "license". Keys can only be specified once. now it reads: error: duplicated key "license". Keys can only be specified once. --> samples/rust/rust_minimal.rs:13:5 | 13 | license: "GPL", | ^^^^^^^ Reviewed-by: Tamir Duberstein Signed-off-by: Gary Guo Reviewed-by: Benno Lossin Link: https://patch.msgid.link/20260112170919.1888584-5-gary@kernel.org Signed-off-by: Miguel Ojeda

rust: macros: convert `#[vtable]` macro to use `syn`

2026-01-27T23:55:24+00:00

`#[vtable]` is converted to use syn. This is more robust than the previous heuristic-based searching of defined methods and functions. When doing so, the trait and impl are split into two code paths as the types are distinct when parsed by `syn`. Reviewed-by: Tamir Duberstein Signed-off-by: Gary Guo Reviewed-by: Benno Lossin Link: https://patch.msgid.link/20260112170919.1888584-4-gary@kernel.org Signed-off-by: Miguel Ojeda

rust: macros: use `quote!` from vendored crate

2026-01-27T23:55:24+00:00

With `quote` crate now vendored in the kernel, we can remove our custom `quote!` macro implementation and just rely on that crate instead. The `quote` crate uses types from the `proc-macro2` library so we also update to use that, and perform conversion in the top-level lib.rs. Clippy complains about unnecessary `.to_string()` as `proc-macro2` provides additional `PartialEq` impl, so they are removed. Reviewed-by: Tamir Duberstein Reviewed-by: Benno Lossin Signed-off-by: Gary Guo Acked-by: David Gow # for kunit Link: https://patch.msgid.link/20260112170919.1888584-3-gary@kernel.org Signed-off-by: Miguel Ojeda

rust: use consistent backtick formatting for NULL in docs

2026-01-26T02:13:27+00:00

Some doc comments use `NULL` while others use plain NULL. Make it consistent by adding backticks everywhere, matching the majority of existing usage. Signed-off-by: Peter Novak Acked-by: Stephen Boyd Acked-by: David Gow Reviewed-by: Alexandre Courbot Acked-by: Danilo Krummrich Link: https://patch.msgid.link/20251130211233.367946-1-seimun018r@gmail.com [ Reworded slightly. - Miguel ] Signed-off-by: Miguel Ojeda

rust: macros: ignore example with module parameters

2026-01-14T18:52:43+00:00

`ModuleParamAccess` uses `SetOnce`, which depends on the helper functions so the `macros` crate example under `rusttest` fails to build: ---- rust/macros/lib.rs - module (line 62) stdout ---- error: linking with `cc` failed: exit status: 1 | = note: "cc" "-m64" ... = note: some arguments are omitted. use `--verbose` to show all linker arguments = note: rust-lld: error: undefined symbol: rust_helper_atomic_try_cmpxchg_relaxed >>> referenced by kernel.ecd446ce39a5fcbb-cgu.3 >>> kernel.kernel.ecd446ce39a5fcbb-cgu.3.rcgu.o:(kernel::sync::set_once::SetOnce$LT$T$GT$::populate::h8b02644e30bd70bc) in archive ./rust/test/libkernel.rlib rust-lld: error: undefined symbol: rust_helper_atomic_set_release >>> referenced by kernel.ecd446ce39a5fcbb-cgu.3 >>> kernel.kernel.ecd446ce39a5fcbb-cgu.3.rcgu.o:(kernel::sync::set_once::SetOnce$LT$T$GT$::populate::h8b02644e30bd70bc) in archive ./rust/test/libkernel.rlib collect2: error: ld returned 1 exit status Thus ignore that example to fix the error. [ Only the first one is needed (the other example does not use parameters), so we can keep it enabled. Thus I removed that second deletion (and reworded a bit). We may want to do something better here later on; on the other hand, we should get KUnit tests for `macros` too eventually, so we may end up removing or repurposing that target anyway, so it is not a big deal. - Miguel ] Reported-by: Miguel Ojeda Closes: https://lore.kernel.org/rust-for-linux/CANiq72mEYacdZmHKvpbahJzO_X_qqYyiSiSTYaWEQZAfp6sbxg@mail.gmail.com/ Signed-off-by: FUJITA Tomonori Fixes: 0b24f9740f26 ("rust: module: update the module macro with module parameter support") Link: https://patch.msgid.link/20251210.082603.290476643413141778.fujita.tomonori@gmail.com Signed-off-by: Miguel Ojeda

Merge tag 'modules-6.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/modules/linux

2025-12-06T16:27:07+00:00

Pull module updates from Daniel Gomez: "Rust module parameter support: - Add Rust module parameter support, enabling Rust kernel modules to declare and use module parameters. The rust_minimal sample module demonstrates this, and the rust null block driver will be the first to use it in the next cycle. This also adds the Rust module files under the modules subsystem as agreed between the Rust and modules maintainers. Hardening: - Add compile-time check for embedded NUL characters in MODULE_*() macros. This module metadata was once used (and maybe still) to bypass license enforcement (LWN article from 2003): https://lwn.net/Articles/82305/ [1] MAINTAINERS: - Add Aaron Tomlin as reviewer for the Modules subsystem" * tag 'modules-6.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/modules/linux: MAINTAINERS: Add myself as reviewer for module support module: Add compile-time check for embedded NUL characters media: radio: si470x: Fix DRIVER_AUTHOR macro definition media: dvb-usb-v2: lmedm04: Fix firmware macro definitions modules: add rust modules files to MAINTAINERS rust: samples: add a module parameter to the rust_minimal sample rust: module: update the module macro with module parameter support rust: module: use a reference in macros::module::module rust: introduce module_param module rust: str: add radix prefixed integer parsing functions rust: sync: add `SetOnce`