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

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

rust: pin-init: Add the `Wrapper` trait.

2025-05-01T16:10:54Z

This trait allows creating `PinInitializers` for wrapper or new-type structs with the inner value structurally pinned, when given the initializer for the inner value. Implement this trait for `UnsafeCell` and `MaybeUninit`. Signed-off-by: Christian Schrefl Link: https://github.com/Rust-for-Linux/pin-init/pull/37/commits/3ab4db083bd7b41a1bc23d937224f975d7400e50 [ Reworded commit message into imperative mode, fixed typo and fixed commit authorship. - Benno ] Signed-off-by: Benno Lossin

rust: pin-init: add `cast_[pin_]init` functions to change the initialized type

2025-05-01T16:08:52Z

These functions cast the given pointer from one type to another. They are particularly useful when initializing transparent wrapper types. Link: https://github.com/Rust-for-Linux/pin-init/pull/39/commits/80c03ddee41b154f1099fd8cc7c2bbd8c80af0ad Reviewed-by: Christian Schrefl Signed-off-by: Benno Lossin