linux/rust/kernel/alloc, branch v6.16

rust: alloc: add missing Markdown code span

2025-05-25T20:58:35Z

Add missing Markdown code span. This was found using the Clippy `doc_markdown` lint, which we may want to enable. Fixes: dd09538fb409 ("rust: alloc: implement `Cmalloc` in module allocator_test") Reviewed-by: Benno Lossin Acked-by: Danilo Krummrich Link: https://lore.kernel.org/r/20250324210359.1199574-5-ojeda@kernel.org Signed-off-by: Miguel Ojeda

rust: remove unneeded Rust 1.87.0 `allow(clippy::ptr_eq)`

2025-05-22T09:46:50Z

For the Rust 1.87.0 release, Clippy was expected to warn with: error: use `core::ptr::eq` when comparing raw pointers --> rust/kernel/list.rs:438:12 | 438 | if self.first == item { | ^^^^^^^^^^^^^^^^^^ help: try: `core::ptr::eq(self.first, item)` | = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#ptr_eq = note: `-D clippy::ptr-eq` implied by `-D warnings` = help: to override `-D warnings` add `#[allow(clippy::ptr_eq)]` However, a backport to relax a bit the `clippy::ptr_eq` finally landed, and thus Clippy did not warn by the time the release happened. Thus remove the `allow`s added back then, which were added just in case the backport did not land in time. See commit a39f30870927 ("rust: allow Rust 1.87.0's `clippy::ptr_eq` lint") for details. Link: https://github.com/rust-lang/rust/pull/140859 [1] Reviewed-by: Alice Ryhl Link: https://lore.kernel.org/r/20250520182125.806758-1-ojeda@kernel.org [ Reworded for clarity. - Miguel ] Signed-off-by: Miguel Ojeda

Merge tag 'alloc-next-v6.16-2025-05-13' of https://github.com/Rust-for-Linux/linux into rust-next

2025-05-18T18:56:03Z

Pull alloc updates from Danilo Krummrich: "Box: - Support for type coercion, e.g. 'Box' to 'Box' if T implements U Vec: - Implement new methods (prerequisites for nova-core and binder) - Vec::truncate() - Vec::resize() - Vec::clear() - Vec::pop() - Vec::push_within_capacity() - New error type: PushError - Vec::drain_all() - Vec::retain() - Vec::remove() - New error type: RemoveError - Vec::insert_within_capacity - New error type: InsertError - Simplify Vec::push() using Vec::spare_capacity_mut() - Split Vec::set_len() into Vec::inc_len() and Vec::dec_len() - Add type invariant Vec::len() <= Vec::capacity - Simplify Vec::truncate() using Vec::dec_len()" * tag 'alloc-next-v6.16-2025-05-13' of https://github.com/Rust-for-Linux/linux: rust: alloc: add Vec::insert_within_capacity rust: alloc: add Vec::remove rust: alloc: add Vec::retain rust: alloc: add Vec::drain_all rust: alloc: add Vec::push_within_capacity rust: alloc: add Vec::pop rust: alloc: add Vec::clear rust: alloc: replace `Vec::set_len` with `inc_len` rust: alloc: refactor `Vec::truncate` using `dec_len` rust: alloc: add `Vec::dec_len` rust: alloc: add Vec::len() <= Vec::capacity invariant rust: alloc: allow coercion from `Box` to `Box` if T implements U rust: alloc: use `spare_capacity_mut` to reduce unsafe rust: alloc: add Vec::resize method rust: alloc: add Vec::truncate method rust: alloc: add missing invariant in Vec::set_len()

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

2025-05-18T18:36:56Z

Pull XArray updates from Andreas Hindborg: "Introduce Rust support for the 'xarray' data structure: - Add a Rust abstraction for the 'xarray' data structure. This abstraction allows Rust code to leverage the 'xarray' to store types that implement 'ForeignOwnable'. This support is a dependency for memory backing feature of the Rust null block driver, which is waiting to be merged. - Set up an entry in MAINTAINERS for the XArray Rust support. Patches will go to the new Rust XArray tree and then via the Rust subsystem tree for now. 'kernel' crate: - Allow 'ForeignOwnable' to carry information about the pointed-to type. This helps asserting alignment requirements for the pointer passed to the foreign language." * tag 'rust-xarray-for-v6.16' of https://github.com/Rust-for-Linux/linux: MAINTAINERS: add entry for Rust XArray API rust: xarray: Add an abstraction for XArray rust: types: add `ForeignOwnable::PointedTo`

rust: convert raw URLs to Markdown autolinks in comments

2025-05-11T22:20:25Z

Some comments in Rust files use raw URLs (http://example.com) rather than Markdown autolinks . This inconsistency makes the documentation less uniform and harder to maintain. This patch converts all remaining raw URLs in Rust code comments to use the Markdown autolink format, maintaining consistency with the rest of the codebase which already uses this style. Suggested-by: Miguel Ojeda Link: https://github.com/Rust-for-Linux/linux/issues/1153 Signed-off-by: Xizhe Yin Link: https://lore.kernel.org/r/509F0B66E3C1575D+20250407033441.5567-1-xizheyin@smail.nju.edu.cn [ Used From form for Signed-off-by. Sorted tags. - Miguel ] Signed-off-by: Miguel Ojeda

rust: alloc: add Vec::insert_within_capacity

2025-05-07T16:40:45Z

This adds a variant of Vec::insert that does not allocate memory. This makes it safe to use this function while holding a spinlock. Rust Binder uses it for the range allocator fast path. Signed-off-by: Alice Ryhl Reviewed-by: Greg Kroah-Hartman Reviewed-by: Benno Lossin Link: https://lore.kernel.org/r/20250502-vec-methods-v5-7-06d20ad9366f@google.com Signed-off-by: Danilo Krummrich

rust: alloc: add Vec::remove

2025-05-07T16:40:02Z

This is needed by Rust Binder in the range allocator, and by upcoming GPU drivers during firmware initialization. Panics in the kernel are best avoided when possible, so an error is returned if the index is out of bounds. An error type is used rather than just returning Option to let callers handle errors with ?. Signed-off-by: Alice Ryhl Reviewed-by: Greg Kroah-Hartman Reviewed-by: Benno Lossin Link: https://lore.kernel.org/r/20250502-vec-methods-v5-6-06d20ad9366f@google.com [ Remove `# Panics` section; `Vec::remove() handles the error properly.` - Danilo ] Signed-off-by: Danilo Krummrich

rust: alloc: add Vec::retain

2025-05-07T16:39:39Z

This adds a common Vec method called `retain` that removes all elements that don't match a certain condition. Rust Binder uses it to find all processes that match a given pid. The stdlib retain method takes &T rather than &mut T and has a separate retain_mut for the &mut T case. However, this is considered an API mistake that can't be fixed now due to backwards compatibility. There's no reason for us to repeat that mistake. Signed-off-by: Alice Ryhl Reviewed-by: Greg Kroah-Hartman Reviewed-by: Benno Lossin Link: https://lore.kernel.org/r/20250502-vec-methods-v5-5-06d20ad9366f@google.com Signed-off-by: Danilo Krummrich

rust: alloc: add Vec::drain_all

2025-05-07T16:39:22Z

This is like the stdlib method drain, except that it's hard-coded to use the entire vector's range. Rust Binder uses it in the range allocator to take ownership of everything in a vector in a case where reusing the vector is desirable. Implementing `DrainAll` in terms of `slice::IterMut` lets us reuse some nice optimizations in core for the case where T is a ZST. Signed-off-by: Alice Ryhl Reviewed-by: Greg Kroah-Hartman Reviewed-by: Benno Lossin Link: https://lore.kernel.org/r/20250502-vec-methods-v5-4-06d20ad9366f@google.com Signed-off-by: Danilo Krummrich

rust: alloc: add Vec::push_within_capacity

2025-05-07T16:39:01Z

This introduces a new method called `push_within_capacity` for appending to a vector without attempting to allocate if the capacity is full. Rust Binder will use this in various places to safely push to a vector while holding a spinlock. The implementation is moved to a push_within_capacity_unchecked method. This is preferred over having push() call push_within_capacity() followed by an unwrap_unchecked() for simpler unsafe. Panics in the kernel are best avoided when possible, so an error is returned if the vector does not have sufficient capacity. An error type is used rather than just returning Result<(),T> to make it more convenient for callers (i.e. they can use ? or unwrap). Signed-off-by: Alice Ryhl Reviewed-by: Greg Kroah-Hartman Reviewed-by: Benno Lossin Link: https://lore.kernel.org/r/20250502-vec-methods-v5-3-06d20ad9366f@google.com [ Remove public visibility from `Vec::push_within_capacity_unchecked()`. - Danilo ] Signed-off-by: Danilo Krummrich