Merge tag 'rust-6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux

Pull Rust updates from Miguel Ojeda:
"Toolchain and infrastructure:

- KUnit '#[test]'s:

- Support KUnit

Merge tag 'rust-6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux

Pull Rust updates from Miguel Ojeda:
"Toolchain and infrastructure:

- KUnit '#[test]'s:

- Support KUnit-mapped 'assert!' macros.

The support that landed last cycle was very basic, and the
'assert!' macros panicked since they were the standard library
ones. Now, they are mapped to the KUnit ones in a similar way to
how is done for doctests, reusing the infrastructure there.

With this, a failing test like:

#[test]
fn my_first_test() {
assert_eq!(42, 43);
}

will report:

# my_first_test: ASSERTION FAILED at rust/kernel/lib.rs:251
Expected 42 == 43 to be true, but is false
# my_first_test.speed: normal
not ok 1 my_first_test

- Support tests with checked 'Result' return types.

The return value of test functions that return a 'Result' will
be checked, thus one can now easily catch errors when e.g. using
the '?' operator in tests.

With this, a failing test like:

#[test]
fn my_test() -> Result {
f()?;
Ok(())
}

will report:

# my_test: ASSERTION FAILED at rust/kernel/lib.rs:321
Expected is_test_result_ok(my_test()) to be true, but is false
# my_test.speed: normal
not ok 1 my_test

- Add 'kunit_tests' to the prelude.

- Clarify the remaining language unstable features in use.

- Compile 'core' with edition 2024 for Rust >= 1.87.

- Workaround 'bindgen' issue with forward references to 'enum' types.

- objtool: relax slice condition to cover more 'noreturn' functions.

- Use absolute paths in macros referencing 'core' and 'kernel'
crates.

- Skip '-mno-fdpic' flag for bindgen in GCC 32-bit arm builds.

- Clean some 'doc_markdown' lint hits -- we may enable it later on.

'kernel' crate:

- 'alloc' module:

- 'Box': support for type coercion, e.g. 'Box<T>' to 'Box<dyn U>'
if 'T' implements 'U'.

- 'Vec': implement new methods (prerequisites for nova-core and
binder): 'truncate', 'resize', 'clear', 'pop',
'push_within_capacity' (with new error type 'PushError'),
'drain_all', 'retain', 'remove' (with new error type
'RemoveError'), insert_within_capacity' (with new error type
'InsertError').

In addition, simplify 'push' using 'spare_capacity_mut', split
'set_len' into 'inc_len' and 'dec_len', add type invariant 'len
<= capacity' and simplify 'truncate' using 'dec_len'.

- 'time' module:

- Morph the Rust hrtimer subsystem into the Rust timekeeping
subsystem, covering delay, sleep, timekeeping, timers. This new
subsystem has all the relevant timekeeping C maintainers listed
in the entry.

- Replace 'Ktime' with 'Delta' and 'Instant' types to represent a
duration of time and a point in time.

- Temporarily add 'Ktime' to 'hrtimer' module to allow 'hrtimer'
to delay converting to 'Instant' and 'Delta'.

- 'xarray' module:

- 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.

- Allow 'ForeignOwnable' to carry information about the pointed-to
type. This helps asserting alignment requirements for the
pointer passed to the foreign language.

- 'container_of!': retain pointer mut-ness and add a compile-time
check of the type of the first parameter ('$field_ptr').

- Support optional message in 'static_assert!'.

- Add C FFI types (e.g. 'c_int') to the prelude.

- 'str' module: simplify KUnit tests 'format!' macro, convert
'rusttest' tests into KUnit, take advantage of the '-> Result'
support in KUnit '#[test]'s.

- 'list' module: add examples for 'List', fix path of
'assert_pinned!' (so far unused macro rule).

- 'workqueue' module: remove 'HasWork::OFFSET'.

- 'page' module: add 'inline' attribute.

'macros' crate:

- 'module' macro: place 'cleanup_module()' in '.exit.text' section.

'pin-init' crate:

- Add 'Wrapper<T>' trait for creating pin-initializers for wrapper
structs with a structurally pinned value such as 'UnsafeCell<T>' or
'MaybeUninit<T>'.

- Add '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.

- Add 'unsafe fn cast_[pin_]init()' functions to unsafely change the
initialized type of an initializer. These are utilized by the
'Wrapper<T>' implementations.

- Add support for visibility in 'Zeroable' derive macro.

- Add support for 'union's in 'Zeroable' derive macro.

- Upstream dev news: streamline CI, fix some bugs. Add new workflows
to check if the user-space version and the one in the kernel tree
have diverged. Use the issues tab [1] to track them, which should
help folks report and diagnose issues w.r.t. 'pin-init' better.

[1] https://github.com/rust-for-linux/pin-init/issues

Documentation:

- Testing: add docs on the new KUnit '#[test]' tests.

- Coding guidelines: explain that '///' vs. '//' applies to private
items too. Add section on C FFI types.

- Quick Start guide: update Ubuntu instructions and split them into
"25.04" and "24.04 LTS and older".

And a few other cleanups and improvements"

* tag 'rust-6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux: (78 commits)
rust: list: Fix typo `much` in arc.rs
rust: check type of `$ptr` in `container_of!`
rust: workqueue: remove HasWork::OFFSET
rust: retain pointer mut-ness in `container_of!`
Documentation: rust: testing: add docs on the new KUnit `#[test]` tests
Documentation: rust: rename `#[test]`s to "`rusttest` host tests"
rust: str: take advantage of the `-> Result` support in KUnit `#[test]`'s
rust: str: simplify KUnit tests `format!` macro
rust: str: convert `rusttest` tests into KUnit
rust: add `kunit_tests` to the prelude
rust: kunit: support checked `-> Result`s in KUnit `#[test]`s
rust: kunit: support KUnit-mapped `assert!` macros in `#[test]`s
rust: make section names plural
rust: list: fix path of `assert_pinned!`
rust: compile libcore with edition 2024 for 1.87+
rust: dma: add missing Markdown code span
rust: task: add missing Markdown code spans and intra-doc links
rust: pci: fix docs related to missing Markdown code spans
rust: alloc: add missing Markdown code span
rust: alloc: add missing Markdown code spans
...

show more ...

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

Pull alloc updates from Danilo Krummrich:
"Box:

- Support for type coercion, e.g. 'Box<T>' to '

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

Pull alloc updates from Danilo Krummrich:
"Box:

- Support for type coercion, e.g. 'Box<T>' to 'Box<dyn U>' 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<T>` to `Box<dyn U>` 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()

show more ...

rust: alloc: add Vec::insert_within_capacity

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 f

rust: alloc: add Vec::insert_within_capacity

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 <aliceryhl@google.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Benno Lossin <lossin@kernel.org>
Link: https://lore.kernel.org/r/20250502-vec-methods-v5-7-06d20ad9366f@google.com
Signed-off-by: Danilo Krummrich <dakr@kernel.org>

show more ...

rust: alloc: add Vec::remove

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, s

rust: alloc: add Vec::remove

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<T> to let callers handle errors with ?.

Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Benno Lossin <lossin@kernel.org>
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 <dakr@kernel.org>

show more ...

rust: alloc: add Vec::push_within_capacity

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 wi

rust: alloc: add Vec::push_within_capacity

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 <aliceryhl@google.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Benno Lossin <lossin@kernel.org>
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 <dakr@kernel.org>

show more ...