linux/rust/pin-init, branch v6.16

Merge tag 'pin-init-v6.16' of https://github.com/Rust-for-Linux/linux into rust-next

2025-05-18T18:42:49Z

Pull pin-init updates from Benno Lossin: "Added: - 'Wrapper' trait for creating pin-initializers for wrapper structs with a structurally pinned value such as 'UnsafeCell' or 'MaybeUninit'. - 'MaybeZeroable' derive macro to try to derive 'Zeroable', but not error if not all fields implement it. This is needed to derive 'Zeroable' for all bindgen-generated structs. - 'unsafe fn cast_[pin_]init()' functions to unsafely change the initialized type of an initializer. These are utilized by the 'Wrapper' implementations. Changed: - Added support for visibility in 'Zeroable' derive macro. - Added support for 'union's in 'Zeroable' derive macro. Upstream dev news: - The CI has been streamlined & some bugs with it have been fixed. I also added new workflows to check if the user-space version and the one in the kernel tree have diverged. - I also started to use the issues [1] tab to keep track of any problems or unexpected/unwanted things. This should help folks report and diagnose issues w.r.t. 'pin-init' better. [1] https://github.com/rust-for-linux/pin-init/issues" * tag 'pin-init-v6.16' of https://github.com/Rust-for-Linux/linux: rust: pin-init: improve documentation for `Zeroable` derive macros rust: pin-init: fix typos rust: pin-init: add `MaybeZeroable` derive macro rust: pin-init: allow `Zeroable` derive macro to also be applied to unions rust: pin-init: allow `pub` fields in `derive(Zeroable)` rust: pin-init: Update the structural pinning link in readme. rust: pin-init: Update Changelog and Readme rust: pin-init: Implement `Wrapper` for `UnsafePinned` behind feature flag. rust: pin-init: Add the `Wrapper` trait. rust: pin-init: add `cast_[pin_]init` functions to change the initialized type rust: pin-init: examples: use `allow` instead of `expect` rust: pin-init: examples: conditionally enable `feature(lint_reasons)` rust: pin-init: internal: skip rustfmt formatting of kernel-only module rust: pin-init: synchronize README.md

rust: clean Rust 1.88.0's `clippy::uninlined_format_args` lint

2025-05-06T22:11:47Z

Starting with Rust 1.88.0 (expected 2025-06-26) [1], `rustc` may move back the `uninlined_format_args` to `style` from `pedantic` (it was there waiting for rust-analyzer suppotr), and thus we will start to see lints like: warning: variables can be used directly in the `format!` string --> rust/macros/kunit.rs:105:37 | 105 | let kunit_wrapper_fn_name = format!("kunit_rust_wrapper_{}", test); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#uninlined_format_args help: change this to | 105 - let kunit_wrapper_fn_name = format!("kunit_rust_wrapper_{}", test); 105 + let kunit_wrapper_fn_name = format!("kunit_rust_wrapper_{test}"); There is even a case that is a pure removal: warning: variables can be used directly in the `format!` string --> rust/macros/module.rs:51:13 | 51 | format!("{field}={content}\0", field = field, content = content) | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#uninlined_format_args help: change this to | 51 - format!("{field}={content}\0", field = field, content = content) 51 + format!("{field}={content}\0") The lints all seem like nice cleanups, thus just apply them. We may want to disable `allow-mixed-uninlined-format-args` in the future. Cc: stable@vger.kernel.org # Needed in 6.12.y and later (Rust is pinned in older LTSs). Link: https://github.com/rust-lang/rust-clippy/pull/14160 [1] Acked-by: Benno Lossin Reviewed-by: Tamir Duberstein Reviewed-by: Alice Ryhl Link: https://lore.kernel.org/r/20250502140237.1659624-6-ojeda@kernel.org Signed-off-by: Miguel Ojeda

rust: pin-init: improve documentation for `Zeroable` derive macros

2025-05-01T16:16:22Z

Specify that both `MaybeZeroable` and `Zeroable` work on `union`s. Add a doc example for a union. Also include an example with visibility on the field. Link: https://github.com/Rust-for-Linux/pin-init/pull/48/commits/ab0985a0e08df06c60a32ca5888f74adcc2c1cf3 Reviewed-by: Christian Schrefl Signed-off-by: Benno Lossin

rust: pin-init: fix typos

2025-05-01T16:15:37Z

Correct two typos in the `Wrapper::pin_init` documentation. Link: https://github.com/Rust-for-Linux/pin-init/pull/48/commits/fd0bf5e244b685188dc642fc4a0bd3f042468fdb Reviewed-by: Christian Schrefl Signed-off-by: Benno Lossin

rust: pin-init: add `MaybeZeroable` derive macro

2025-05-01T16:15:26Z

This derive macro implements `Zeroable` for structs & unions precisely if all fields also implement `Zeroable` and does nothing otherwise. The plain `Zeroable` derive macro instead errors when it cannot derive `Zeroable` safely. The `MaybeZeroable` derive macro is useful in cases where manual checking is infeasible such as with the bindings crate. Move the zeroable generics parsing into a standalone function in order to avoid code duplication between the two derive macros. Link: https://github.com/Rust-for-Linux/pin-init/pull/42/commits/1165cdad1a391b923efaf30cf76bc61e38da022e Signed-off-by: Benno Lossin

rust: pin-init: allow `Zeroable` derive macro to also be applied to unions

2025-05-01T16:15:12Z

Enabling the same behavior for unions as for structs is correct, but could be relaxed: the valid bit patterns for unions are the union of all valid bit patterns of their fields. So for a union to implement `Zeroable`, only a single field needs to implement `Zeroable`. This can be a future improvement, as it is currently only needed for unions where all fields implement `Zeroable`. There is no danger for mis-parsing with the two optional tokens (ie neither one or both tokens are parsed), as the compiler will already have rejected that before giving it as the input to the derive macro. Link: https://github.com/Rust-for-Linux/pin-init/pull/42/commits/5927b497ce522d82f6c082d5ba9235df57bfdb32 Signed-off-by: Benno Lossin

rust: pin-init: allow `pub` fields in `derive(Zeroable)`

2025-05-01T16:14:46Z

Add support for parsing `pub`, `pub(crate)` and `pub(super)` to the derive macro `Zeroable`. Link: https://github.com/Rust-for-Linux/pin-init/pull/42/commits/e8311e52ca57273e7ed6d099144384971677a0ba Signed-off-by: Benno Lossin

rust: pin-init: Update the structural pinning link in readme.

2025-05-01T16:14:40Z

The previous link anchor was broken in rust 1.77, because the documentation was refactored in upstream rust. Change the link to refer to the new section in the rust documentation. Signed-off-by: Christian Schrefl Link: https://github.com/Rust-for-Linux/pin-init/pull/37/commits/a146142fe18cafa52f8c6da306ca2729d789cfbf [ Fixed commit authorship. - Benno ] Signed-off-by: Benno Lossin

rust: pin-init: Update Changelog and Readme

2025-05-01T16:14:29Z

Add Changelog entry for the `Wrapper` trait and document the `unsafe-pinned` feature in the Readme. Signed-off-by: Christian Schrefl Link: https://github.com/Rust-for-Linux/pin-init/pull/37/commits/986555f564645efb238e8092c6314388c859efe5 [ Fixed commit authorship. - Benno ] Signed-off-by: Benno Lossin

rust: pin-init: Implement `Wrapper` for `UnsafePinned` behind feature flag.

2025-05-01T16:13:56Z

Add the `unsafe-pinned` feature which gates the `Wrapper` implementation of the `core::pin::UnsafePinned` struct. For now this is just a cargo feature, but once `core::pin::UnsafePinned` is stable a config flag can be added to allow the usage of this implementation in the linux kernel. Signed-off-by: Christian Schrefl Link: https://github.com/Rust-for-Linux/pin-init/pull/37/commits/99cb1934425357e780ea5b0628f66633123847b8 [ Fixed commit authorship. - Benno ] Signed-off-by: Benno Lossin