Merge tag 'rust-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux

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

- Enable a set of Clippy lints: 'ptr_as_pt

Merge tag 'rust-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux

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

- Enable a set of Clippy lints: 'ptr_as_ptr', 'ptr_cast_constness',
'as_ptr_cast_mut', 'as_underscore', 'cast_lossless' and
'ref_as_ptr'

These are intended to avoid type casts with the 'as' operator,
which are quite powerful, into restricted variants that are less
powerful and thus should help to avoid mistakes

- Remove the 'author' key now that most instances were moved to the
plural one in the previous cycle

'kernel' crate:

- New 'bug' module: add 'warn_on!' macro which reuses the existing
'BUG'/'WARN' infrastructure, i.e. it respects the usual sysctls and
kernel parameters:

warn_on!(value == 42);

To avoid duplicating the assembly code, the same strategy is
followed as for the static branch code in order to share the
assembly between both C and Rust

This required a few rearrangements on C arch headers -- the
existing C macros should still generate the same outputs, thus no
functional change expected there

- 'workqueue' module: add delayed work items, including a
'DelayedWork' struct, a 'impl_has_delayed_work!' macro and an
'enqueue_delayed' method, e.g.:

/// Enqueue the struct for execution on the system workqueue,
/// where its value will be printed 42 jiffies later.
fn print_later(value: Arc<MyStruct>) {
let _ = workqueue::system().enqueue_delayed(value, 42);
}

- New 'bits' module: add support for 'bit' and 'genmask' functions,
with runtime- and compile-time variants, e.g.:

static_assert!(0b00010000 == bit_u8(4));
static_assert!(0b00011110 == genmask_u8(1..=4));

assert!(checked_bit_u32(u32::BITS).is_none());

- 'uaccess' module: add 'UserSliceReader::strcpy_into_buf', which
reads NUL-terminated strings from userspace into a '&CStr'

Introduce 'UserPtr' newtype, similar in purpose to '__user' in C,
to minimize mistakes handling userspace pointers, including mixing
them up with integers and leaking them via the 'Debug' trait. Add
it to the prelude, too

- Start preparations for the replacement of our custom 'CStr' type
with the analogous type in the 'core' standard library. This will
take place across several cycles to make it easier. For this one,
it includes a new 'fmt' module, using upstream method names and
some other cleanups

Replace 'fmt!' with a re-export, which helps Clippy lint properly,
and clean up the found 'uninlined-format-args' instances

- 'dma' module:

- Clarify wording and be consistent in 'coherent' nomenclature

- Convert the 'read!()' and 'write!()' macros to return a 'Result'

- Add 'as_slice()', 'write()' methods in 'CoherentAllocation'

- Expose 'count()' and 'size()' in 'CoherentAllocation' and add
the corresponding type invariants

- Implement 'CoherentAllocation::dma_handle_with_offset()'

- 'time' module:

- Make 'Instant' generic over clock source. This allows the
compiler to assert that arithmetic expressions involving the
'Instant' use 'Instants' based on the same clock source

- Make 'HrTimer' generic over the timer mode. 'HrTimer' timers
take a 'Duration' or an 'Instant' when setting the expiry time,
depending on the timer mode. With this change, the compiler can
check the type matches the timer mode

- Add an abstraction for 'fsleep'. 'fsleep' is a flexible sleep
function that will select an appropriate sleep method depending
on the requested sleep time

- Avoid 64-bit divisions on 32-bit hardware when calculating
timestamps

- Seal the 'HrTimerMode' trait. This prevents users of the
'HrTimerMode' from implementing the trait on their own types

- Pass the correct timer mode ID to 'hrtimer_start_range_ns()'

- 'list' module: remove 'OFFSET' constants, allowing to remove
pointer arithmetic; now 'impl_list_item!' invokes
'impl_has_list_links!' or 'impl_has_list_links_self_ptr!'. Other
simplifications too

- 'types' module: remove 'ForeignOwnable::PointedTo' in favor of a
constant, which avoids exposing the type of the opaque pointer, and
require 'into_foreign' to return non-null

Remove the 'Either<L, R>' type as well. It is unused, and we want
to encourage the use of custom enums for concrete use cases

- 'sync' module: implement 'Borrow' and 'BorrowMut' for 'Arc' types
to allow them to be used in generic APIs

- 'alloc' module: implement 'Borrow' and 'BorrowMut' for 'Box<T, A>';
and 'Borrow', 'BorrowMut' and 'Default' for 'Vec<T, A>'

- 'Opaque' type: add 'cast_from' method to perform a restricted cast
that cannot change the inner type and use it in callers of
'container_of!'. Rename 'raw_get' to 'cast_into' to match it

- 'rbtree' module: add 'is_empty' method

- 'sync' module: new 'aref' submodule to hold 'AlwaysRefCounted' and
'ARef', which are moved from the too general 'types' module which
we want to reduce or eventually remove. Also fix a safety comment
in 'static_lock_class'

'pin-init' crate:

- Add 'impl<T, E> [Pin]Init<T, E> for Result<T, E>', so results are
now (pin-)initializers

- Add 'Zeroable::init_zeroed()' that delegates to 'init_zeroed()'

- New 'zeroed()', a safe version of 'mem::zeroed()' and also provide
it via 'Zeroable::zeroed()'

- Implement 'Zeroable' for 'Option<&T>', 'Option<&mut T>' and for
'Option<[unsafe] [extern "abi"] fn(...args...) -> ret>' for
'"Rust"' and '"C"' ABIs and up to 20 arguments

- Changed blanket impls of 'Init' and 'PinInit' from 'impl<T, E>
[Pin]Init<T, E> for T' to 'impl<T> [Pin]Init<T> for T'

- Renamed 'zeroed()' to 'init_zeroed()'

- Upstream dev news: improve CI more to deny warnings, use
'--all-targets'. Check the synchronization status of the two
'-next' branches in upstream and the kernel

MAINTAINERS:

- Add Vlastimil Babka, Liam R. Howlett, Uladzislau Rezki and Lorenzo
Stoakes as reviewers (thanks everyone)

And a few other cleanups and improvements"

* tag 'rust-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux: (76 commits)
rust: Add warn_on macro
arm64/bug: Add ARCH_WARN_ASM macro for BUG/WARN asm code sharing with Rust
riscv/bug: Add ARCH_WARN_ASM macro for BUG/WARN asm code sharing with Rust
x86/bug: Add ARCH_WARN_ASM macro for BUG/WARN asm code sharing with Rust
rust: kernel: move ARef and AlwaysRefCounted to sync::aref
rust: sync: fix safety comment for `static_lock_class`
rust: types: remove `Either<L, R>`
rust: kernel: use `core::ffi::CStr` method names
rust: str: add `CStr` methods matching `core::ffi::CStr`
rust: str: remove unnecessary qualification
rust: use `kernel::{fmt,prelude::fmt!}`
rust: kernel: add `fmt` module
rust: kernel: remove `fmt!`, fix clippy::uninlined-format-args
scripts: rust: emit path candidates in panic message
scripts: rust: replace length checks with match
rust: list: remove nonexistent generic parameter in link
rust: bits: add support for bits/genmask macros
rust: list: remove OFFSET constants
rust: list: add `impl_list_item!` examples
rust: list: use fully qualified path
...

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