<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/rust/kernel/types.rs, branch v7.2-rc1</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>rust: types: add `ForLt` trait for higher-ranked lifetime support</title>
<updated>2026-05-27T14:24:59+00:00</updated>
<author>
<name>Gary Guo</name>
<email>gary@garyguo.net</email>
</author>
<published>2026-05-25T20:21:09+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=e189bdb687a56bcf389798f1d3a2f261fff2ef54'/>
<id>e189bdb687a56bcf389798f1d3a2f261fff2ef54</id>
<content type='text'>
There are a few cases, e.g. when dealing with data referencing each
other, one might want to write code that is generic over lifetimes. For
example, if you want to take a function that takes `&amp;'a Foo` and gives
`Bar&lt;'a&gt;`, you can write:

    f: impl for&lt;'a&gt; FnOnce(&amp;'a Foo) -&gt; Bar&lt;'a&gt;,

However, it becomes tricky when you want that function to not have a
fixed `Bar`, but have it be generic again. In this case, one needs
something that is generic over types that are themselves generic over
lifetimes.

`ForLt` provides such support. It provides a trait `ForLt` which
describes a type generic over a lifetime. One may use `ForLt::Of&lt;'a&gt;` to
get an instance of a type for a specific lifetime.

For the case of cross referencing, one would almost always want the
lifetime to be covariant. Therefore this is also made a requirement for
the `ForLt` trait, so functions with `ForLt` trait bound can assume
covariance.

A macro `ForLt!()` is provided to be able to obtain a type that
implements `ForLt`. For example, `ForLt!(for&lt;'a&gt; Bar&lt;'a&gt;)` would yield a
type that `&lt;TheType as ForLt&gt;::Of&lt;'a&gt;` is `Bar&lt;'a&gt;`. This also works
with lifetime elision, e.g. `ForLt!(Bar&lt;'_&gt;)` or for types without
lifetime at all, e.g. `ForLt!(u32)`.

The API design draws inspiration from the higher-kinded-types [1] crate,
however a different design decision has been taken (e.g. covariance
requirement) and the implementation is independent.

License headers use "Apache-2.0 OR MIT" because I anticipate this to be
used in pin-init crate too which is licensed as such.

Link: https://docs.rs/higher-kinded-types/ [1]
Reviewed-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Reviewed-by: Eliot Courtney &lt;ecourtney@nvidia.com&gt;
Signed-off-by: Gary Guo &lt;gary@garyguo.net&gt;
Acked-by: Miguel Ojeda &lt;ojeda@kernel.org&gt;
Reviewed-by: Alexandre Courbot &lt;acourbot@nvidia.com&gt;
Link: https://patch.msgid.link/20260525202921.124698-23-dakr@kernel.org
[ Handle macro_rules! invocations in the ForLt! proc macro's covariance
  and WF checks. Since proc macros cannot expand macro_rules!, add a
  visit_macro() implementation to conservatively assume macro
  invocations may contain lifetimes, forcing them through the
  compiler-assisted covariance proof.

  Fix a few typos in the documentation and in the commit message, add
  empty lines before samples, add missing periods and consistently use
  markdown.

  - Danilo ]
Signed-off-by: Danilo Krummrich &lt;dakr@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
There are a few cases, e.g. when dealing with data referencing each
other, one might want to write code that is generic over lifetimes. For
example, if you want to take a function that takes `&amp;'a Foo` and gives
`Bar&lt;'a&gt;`, you can write:

    f: impl for&lt;'a&gt; FnOnce(&amp;'a Foo) -&gt; Bar&lt;'a&gt;,

However, it becomes tricky when you want that function to not have a
fixed `Bar`, but have it be generic again. In this case, one needs
something that is generic over types that are themselves generic over
lifetimes.

`ForLt` provides such support. It provides a trait `ForLt` which
describes a type generic over a lifetime. One may use `ForLt::Of&lt;'a&gt;` to
get an instance of a type for a specific lifetime.

For the case of cross referencing, one would almost always want the
lifetime to be covariant. Therefore this is also made a requirement for
the `ForLt` trait, so functions with `ForLt` trait bound can assume
covariance.

A macro `ForLt!()` is provided to be able to obtain a type that
implements `ForLt`. For example, `ForLt!(for&lt;'a&gt; Bar&lt;'a&gt;)` would yield a
type that `&lt;TheType as ForLt&gt;::Of&lt;'a&gt;` is `Bar&lt;'a&gt;`. This also works
with lifetime elision, e.g. `ForLt!(Bar&lt;'_&gt;)` or for types without
lifetime at all, e.g. `ForLt!(u32)`.

The API design draws inspiration from the higher-kinded-types [1] crate,
however a different design decision has been taken (e.g. covariance
requirement) and the implementation is independent.

License headers use "Apache-2.0 OR MIT" because I anticipate this to be
used in pin-init crate too which is licensed as such.

Link: https://docs.rs/higher-kinded-types/ [1]
Reviewed-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Reviewed-by: Eliot Courtney &lt;ecourtney@nvidia.com&gt;
Signed-off-by: Gary Guo &lt;gary@garyguo.net&gt;
Acked-by: Miguel Ojeda &lt;ojeda@kernel.org&gt;
Reviewed-by: Alexandre Courbot &lt;acourbot@nvidia.com&gt;
Link: https://patch.msgid.link/20260525202921.124698-23-dakr@kernel.org
[ Handle macro_rules! invocations in the ForLt! proc macro's covariance
  and WF checks. Since proc macros cannot expand macro_rules!, add a
  visit_macro() implementation to conservatively assume macro
  invocations may contain lifetimes, forcing them through the
  compiler-assisted covariance proof.

  Fix a few typos in the documentation and in the commit message, add
  empty lines before samples, add missing periods and consistently use
  markdown.

  - Danilo ]
Signed-off-by: Danilo Krummrich &lt;dakr@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>rust: alloc: remove `'static` bound on `ForeignOwnable`</title>
<updated>2026-05-27T14:22:41+00:00</updated>
<author>
<name>Gary Guo</name>
<email>gary@garyguo.net</email>
</author>
<published>2026-05-25T20:20:49+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=e9df918d61e08f4281c3bcd42486f1505f396b1d'/>
<id>e9df918d61e08f4281c3bcd42486f1505f396b1d</id>
<content type='text'>
The `'static` bound is currently necessary because there's no
restriction on the lifetime of the GAT. Add a `Self: 'a` bound to
restrict possible lifetimes on `Borrowed` and `BorrowedMut`, and lift
the `'static` requirement.

Reviewed-by: Alexandre Courbot &lt;acourbot@nvidia.com&gt;
Reviewed-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Gary Guo &lt;gary@garyguo.net&gt;
Acked-by: Miguel Ojeda &lt;ojeda@kernel.org&gt;
Link: https://patch.msgid.link/20260525202921.124698-3-dakr@kernel.org
Signed-off-by: Danilo Krummrich &lt;dakr@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The `'static` bound is currently necessary because there's no
restriction on the lifetime of the GAT. Add a `Self: 'a` bound to
restrict possible lifetimes on `Borrowed` and `BorrowedMut`, and lift
the `'static` requirement.

Reviewed-by: Alexandre Courbot &lt;acourbot@nvidia.com&gt;
Reviewed-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Gary Guo &lt;gary@garyguo.net&gt;
Acked-by: Miguel Ojeda &lt;ojeda@kernel.org&gt;
Link: https://patch.msgid.link/20260525202921.124698-3-dakr@kernel.org
Signed-off-by: Danilo Krummrich &lt;dakr@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>rust: types: remove temporary re-exports of ARef and AlwaysRefCounted</title>
<updated>2026-03-15T19:30:29+00:00</updated>
<author>
<name>Shankari Anand</name>
<email>shankari.ak0208@gmail.com</email>
</author>
<published>2026-01-02T20:27:14+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=79e25710e7227228902d672417b552dd1d7e5d3b'/>
<id>79e25710e7227228902d672417b552dd1d7e5d3b</id>
<content type='text'>
Remove the temporary re-exports of `ARef` and `AlwaysRefCounted`
from `types.rs` now that all in-tree users have been updated to
import them directly from `sync::aref`.

These re-exports were originally added to avoid breaking the
kernel build during the transition period while call sites were
incrementally migrated. With all users updated, they are no
longer needed.

Suggested-by: Benno Lossin &lt;lossin@kernel.org&gt;
Link: https://github.com/Rust-for-Linux/linux/issues/1173
Signed-off-by: Shankari Anand &lt;shankari.ak0208@gmail.com&gt;
Link: https://patch.msgid.link/20260102202714.184223-5-shankari.ak0208@gmail.com
Signed-off-by: Miguel Ojeda &lt;ojeda@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Remove the temporary re-exports of `ARef` and `AlwaysRefCounted`
from `types.rs` now that all in-tree users have been updated to
import them directly from `sync::aref`.

These re-exports were originally added to avoid breaking the
kernel build during the transition period while call sites were
incrementally migrated. With all users updated, they are no
longer needed.

Suggested-by: Benno Lossin &lt;lossin@kernel.org&gt;
Link: https://github.com/Rust-for-Linux/linux/issues/1173
Signed-off-by: Shankari Anand &lt;shankari.ak0208@gmail.com&gt;
Link: https://patch.msgid.link/20260102202714.184223-5-shankari.ak0208@gmail.com
Signed-off-by: Miguel Ojeda &lt;ojeda@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>rust: allow `clippy::disallowed_names` for doctests</title>
<updated>2025-11-17T21:53:27+00:00</updated>
<author>
<name>Miguel Ojeda</name>
<email>ojeda@kernel.org</email>
</author>
<published>2025-11-17T08:07:13+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=e5d330e13f67d574f683c052c9a342814fd8fa39'/>
<id>e5d330e13f67d574f683c052c9a342814fd8fa39</id>
<content type='text'>
Examples (i.e. doctests) may want to use names such as `foo`, thus the
`clippy::disallowed_names` lint [1] gets in the way.

Thus allow it for all doctests.

In addition, remove it from the existing `expect`s we have in a few
doctests.

This does not mean that we should stop trying to find good names for
our examples, though.

Link: https://rust-lang.github.io/rust-clippy/stable/index.html#disallowed_names [1]
Suggested-by: Alice Ryhl &lt;aliceryhl@google.com&gt;
Link: https://lore.kernel.org/rust-for-linux/aRHSLChi5HYXW4-9@google.com/
Reviewed-by: Alice Ryhl &lt;aliceryhl@google.com&gt;
Acked-by: Benno Lossin &lt;lossin@kernel.org&gt;
Link: https://patch.msgid.link/20251117080714.876978-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda &lt;ojeda@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Examples (i.e. doctests) may want to use names such as `foo`, thus the
`clippy::disallowed_names` lint [1] gets in the way.

Thus allow it for all doctests.

In addition, remove it from the existing `expect`s we have in a few
doctests.

This does not mean that we should stop trying to find good names for
our examples, though.

Link: https://rust-lang.github.io/rust-clippy/stable/index.html#disallowed_names [1]
Suggested-by: Alice Ryhl &lt;aliceryhl@google.com&gt;
Link: https://lore.kernel.org/rust-for-linux/aRHSLChi5HYXW4-9@google.com/
Reviewed-by: Alice Ryhl &lt;aliceryhl@google.com&gt;
Acked-by: Benno Lossin &lt;lossin@kernel.org&gt;
Link: https://patch.msgid.link/20251117080714.876978-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda &lt;ojeda@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>rust: allow `unreachable_pub` for doctests</title>
<updated>2025-11-17T07:41:31+00:00</updated>
<author>
<name>Miguel Ojeda</name>
<email>ojeda@kernel.org</email>
</author>
<published>2025-11-10T11:35:27+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=ab844cf32058d6ba9bd98a921afa2256085e21fc'/>
<id>ab844cf32058d6ba9bd98a921afa2256085e21fc</id>
<content type='text'>
Examples (i.e. doctests) may want to show public items such as structs,
thus the `unreachable_pub` warning is not very helpful.

Thus allow it for all doctests.

In addition, remove it from the existing `expect`s we have in a couple
doctests.

Suggested-by: Alice Ryhl &lt;aliceryhl@google.com&gt;
Link: https://lore.kernel.org/rust-for-linux/aRG9VjsaCjsvAwUn@google.com/
Reviewed-by: David Gow &lt;davidgow@google.com&gt;
Acked-by: Benno Lossin &lt;lossin@kernel.org&gt;
Reviewed-by: Alice Ryhl &lt;aliceryhl@google.com&gt;
Link: https://patch.msgid.link/20251110113528.1658238-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda &lt;ojeda@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Examples (i.e. doctests) may want to show public items such as structs,
thus the `unreachable_pub` warning is not very helpful.

Thus allow it for all doctests.

In addition, remove it from the existing `expect`s we have in a couple
doctests.

Suggested-by: Alice Ryhl &lt;aliceryhl@google.com&gt;
Link: https://lore.kernel.org/rust-for-linux/aRG9VjsaCjsvAwUn@google.com/
Reviewed-by: David Gow &lt;davidgow@google.com&gt;
Acked-by: Benno Lossin &lt;lossin@kernel.org&gt;
Reviewed-by: Alice Ryhl &lt;aliceryhl@google.com&gt;
Link: https://patch.msgid.link/20251110113528.1658238-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda &lt;ojeda@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'rust-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux</title>
<updated>2025-08-03T20:49:10+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2025-08-03T20:49:10+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=352af6a011d586ff042db4b2d1f7421875eb8a14'/>
<id>352af6a011d586ff042db4b2d1f7421875eb8a14</id>
<content type='text'>
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&lt;MyStruct&gt;) {
             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 '&amp;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&lt;L, R&gt;' 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&lt;T, A&gt;';
     and 'Borrow', 'BorrowMut' and 'Default' for 'Vec&lt;T, A&gt;'

   - '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&lt;T, E&gt; [Pin]Init&lt;T, E&gt; for Result&lt;T, E&gt;', 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&lt;&amp;T&gt;', 'Option&lt;&amp;mut T&gt;' and for
     'Option&lt;[unsafe] [extern "abi"] fn(...args...) -&gt; ret&gt;' for
     '"Rust"' and '"C"' ABIs and up to 20 arguments

   - Changed blanket impls of 'Init' and 'PinInit' from 'impl&lt;T, E&gt;
     [Pin]Init&lt;T, E&gt; for T' to 'impl&lt;T&gt; [Pin]Init&lt;T&gt; 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&lt;L, R&gt;`
  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
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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&lt;MyStruct&gt;) {
             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 '&amp;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&lt;L, R&gt;' 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&lt;T, A&gt;';
     and 'Borrow', 'BorrowMut' and 'Default' for 'Vec&lt;T, A&gt;'

   - '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&lt;T, E&gt; [Pin]Init&lt;T, E&gt; for Result&lt;T, E&gt;', 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&lt;&amp;T&gt;', 'Option&lt;&amp;mut T&gt;' and for
     'Option&lt;[unsafe] [extern "abi"] fn(...args...) -&gt; ret&gt;' for
     '"Rust"' and '"C"' ABIs and up to 20 arguments

   - Changed blanket impls of 'Init' and 'PinInit' from 'impl&lt;T, E&gt;
     [Pin]Init&lt;T, E&gt; for T' to 'impl&lt;T&gt; [Pin]Init&lt;T&gt; 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&lt;L, R&gt;`
  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
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>rust: kernel: move ARef and AlwaysRefCounted to sync::aref</title>
<updated>2025-07-22T11:52:14+00:00</updated>
<author>
<name>Shankari Anand</name>
<email>shankari.ak0208@gmail.com</email>
</author>
<published>2025-07-15T11:04:23+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=07dad44aa9a93b16af19e8609a10b241c352b440'/>
<id>07dad44aa9a93b16af19e8609a10b241c352b440</id>
<content type='text'>
Move the definitions of `ARef` and `AlwaysRefCounted` from `types.rs`
to a new file `sync/aref.rs`.  Define the corresponding `aref` module
under `rust/kernel/sync.rs`.  These types are better grouped in `sync`.

To avoid breaking existing imports, they are re-exported from `types.rs`.
Drop unused imports `mem::ManuallyDrop`, `ptr::NonNull` from `types.rs`,
they are now only used in `sync/aref.rs`, where they are already imported.

Suggested-by: Benno Lossin &lt;lossin@kernel.org&gt;
Link: https://github.com/Rust-for-Linux/linux/issues/1173
Signed-off-by: Shankari Anand &lt;shankari.ak0208@gmail.com&gt;
Reviewed-by: Benno Lossin &lt;lossin@kernel.org&gt;
Link: https://lore.kernel.org/r/20250715110423.334744-1-shankari.ak0208@gmail.com
[ Added missing `///`. Changed module title. Reworded slightly. - Miguel ]
Signed-off-by: Miguel Ojeda &lt;ojeda@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Move the definitions of `ARef` and `AlwaysRefCounted` from `types.rs`
to a new file `sync/aref.rs`.  Define the corresponding `aref` module
under `rust/kernel/sync.rs`.  These types are better grouped in `sync`.

To avoid breaking existing imports, they are re-exported from `types.rs`.
Drop unused imports `mem::ManuallyDrop`, `ptr::NonNull` from `types.rs`,
they are now only used in `sync/aref.rs`, where they are already imported.

Suggested-by: Benno Lossin &lt;lossin@kernel.org&gt;
Link: https://github.com/Rust-for-Linux/linux/issues/1173
Signed-off-by: Shankari Anand &lt;shankari.ak0208@gmail.com&gt;
Reviewed-by: Benno Lossin &lt;lossin@kernel.org&gt;
Link: https://lore.kernel.org/r/20250715110423.334744-1-shankari.ak0208@gmail.com
[ Added missing `///`. Changed module title. Reworded slightly. - Miguel ]
Signed-off-by: Miguel Ojeda &lt;ojeda@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>rust: types: remove `Either&lt;L, R&gt;`</title>
<updated>2025-07-21T21:54:19+00:00</updated>
<author>
<name>Benno Lossin</name>
<email>lossin@kernel.org</email>
</author>
<published>2025-05-19T12:43:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=28753212e0f9c61afd859acf1d678f5de7faa4b8'/>
<id>28753212e0f9c61afd859acf1d678f5de7faa4b8</id>
<content type='text'>
This enum is not used. Additionally, using it would result in poor
ergonomics, because in order to do any operation on a value it has to be
matched first. Our version of `Either` also doesn't provide any helper
methods making it even more difficult to use.

The alternative of creating a custom enum for the concrete use-case also
is much better for ergonomics. As one can provide functions on the type
directly and users don't need to match the value manually.

Signed-off-by: Benno Lossin &lt;lossin@kernel.org&gt;
Reviewed-by: Danilo Krummrich &lt;dakr@kernel.org&gt;
Link: https://lore.kernel.org/r/20250519124304.79237-1-lossin@kernel.org
Signed-off-by: Miguel Ojeda &lt;ojeda@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This enum is not used. Additionally, using it would result in poor
ergonomics, because in order to do any operation on a value it has to be
matched first. Our version of `Either` also doesn't provide any helper
methods making it even more difficult to use.

The alternative of creating a custom enum for the concrete use-case also
is much better for ergonomics. As one can provide functions on the type
directly and users don't need to match the value manually.

Signed-off-by: Benno Lossin &lt;lossin@kernel.org&gt;
Reviewed-by: Danilo Krummrich &lt;dakr@kernel.org&gt;
Link: https://lore.kernel.org/r/20250519124304.79237-1-lossin@kernel.org
Signed-off-by: Miguel Ojeda &lt;ojeda@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>rust: types: rename Opaque::raw_get to cast_into</title>
<updated>2025-07-15T20:26:11+00:00</updated>
<author>
<name>Alice Ryhl</name>
<email>aliceryhl@google.com</email>
</author>
<published>2025-06-24T15:27:56+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=64fb810bce03a4e2b4d3ecbba04bb97da3536dd8'/>
<id>64fb810bce03a4e2b4d3ecbba04bb97da3536dd8</id>
<content type='text'>
In the previous patch we added Opaque::cast_from() that performs the
opposite operation to Opaque::raw_get(). For consistency with this
naming, rename raw_get() to cast_from().

There are a few other options such as calling cast_from() something
closer to raw_get() rather than renaming this method. However, I could
not find a great naming scheme that works with raw_get(). The previous
version of this patch used from_raw(), but functions of that name
typically have a different signature, so that's not a great option.

Suggested-by: Danilo Krummrich &lt;dakr@kernel.org&gt;
Signed-off-by: Alice Ryhl &lt;aliceryhl@google.com&gt;
Acked-by: Benno Lossin &lt;lossin@kernel.org&gt;
Acked-by: Andreas Hindborg &lt;a.hindborg@kernel.org&gt;
Acked-by: Boqun Feng &lt;boqun.feng@gmail.com&gt;
Reviewed-by: Danilo Krummrich &lt;dakr@kernel.org&gt;
Acked-by: Danilo Krummrich &lt;dakr@kernel.org&gt;
Link: https://lore.kernel.org/r/20250624-opaque-from-raw-v2-2-e4da40bdc59c@google.com
[ Removed `HrTimer::raw_get` change. - Miguel ]
Signed-off-by: Miguel Ojeda &lt;ojeda@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
In the previous patch we added Opaque::cast_from() that performs the
opposite operation to Opaque::raw_get(). For consistency with this
naming, rename raw_get() to cast_from().

There are a few other options such as calling cast_from() something
closer to raw_get() rather than renaming this method. However, I could
not find a great naming scheme that works with raw_get(). The previous
version of this patch used from_raw(), but functions of that name
typically have a different signature, so that's not a great option.

Suggested-by: Danilo Krummrich &lt;dakr@kernel.org&gt;
Signed-off-by: Alice Ryhl &lt;aliceryhl@google.com&gt;
Acked-by: Benno Lossin &lt;lossin@kernel.org&gt;
Acked-by: Andreas Hindborg &lt;a.hindborg@kernel.org&gt;
Acked-by: Boqun Feng &lt;boqun.feng@gmail.com&gt;
Reviewed-by: Danilo Krummrich &lt;dakr@kernel.org&gt;
Acked-by: Danilo Krummrich &lt;dakr@kernel.org&gt;
Link: https://lore.kernel.org/r/20250624-opaque-from-raw-v2-2-e4da40bdc59c@google.com
[ Removed `HrTimer::raw_get` change. - Miguel ]
Signed-off-by: Miguel Ojeda &lt;ojeda@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>rust: types: add Opaque::cast_from</title>
<updated>2025-07-15T19:01:48+00:00</updated>
<author>
<name>Alice Ryhl</name>
<email>aliceryhl@google.com</email>
</author>
<published>2025-06-24T15:27:55+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=8802e168437840ea0b1d5ca571cd3e95681e9e2b'/>
<id>8802e168437840ea0b1d5ca571cd3e95681e9e2b</id>
<content type='text'>
Since commit b20fbbc08a36 ("rust: check type of `$ptr` in
`container_of!`") we have enforced that the field pointer passed to
container_of! must match the declared field. This caused mismatches when
using a pointer to bindings::x for fields of type Opaque&lt;bindings::x&gt;.

This situation encourages the user to simply pass field.cast() to the
container_of! macro, but this is not great because you might
accidentally pass a *mut bindings::y when the field type is
Opaque&lt;bindings::x&gt;, which would be wrong.

To help catch this kind of mistake, add a new Opaque::cast_from that
wraps a raw pointer in Opaque without changing the inner type. Also
update the docs to reflect this as well as some existing users.

Signed-off-by: Alice Ryhl &lt;aliceryhl@google.com&gt;
Acked-by: Andreas Hindborg &lt;a.hindborg@kernel.org&gt;
Acked-by: Boqun Feng &lt;boqun.feng@gmail.com&gt;
Reviewed-by: Danilo Krummrich &lt;dakr@kernel.org&gt;
Acked-by: Danilo Krummrich &lt;dakr@kernel.org&gt;
Link: https://lore.kernel.org/r/20250624-opaque-from-raw-v2-1-e4da40bdc59c@google.com
Signed-off-by: Miguel Ojeda &lt;ojeda@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Since commit b20fbbc08a36 ("rust: check type of `$ptr` in
`container_of!`") we have enforced that the field pointer passed to
container_of! must match the declared field. This caused mismatches when
using a pointer to bindings::x for fields of type Opaque&lt;bindings::x&gt;.

This situation encourages the user to simply pass field.cast() to the
container_of! macro, but this is not great because you might
accidentally pass a *mut bindings::y when the field type is
Opaque&lt;bindings::x&gt;, which would be wrong.

To help catch this kind of mistake, add a new Opaque::cast_from that
wraps a raw pointer in Opaque without changing the inner type. Also
update the docs to reflect this as well as some existing users.

Signed-off-by: Alice Ryhl &lt;aliceryhl@google.com&gt;
Acked-by: Andreas Hindborg &lt;a.hindborg@kernel.org&gt;
Acked-by: Boqun Feng &lt;boqun.feng@gmail.com&gt;
Reviewed-by: Danilo Krummrich &lt;dakr@kernel.org&gt;
Acked-by: Danilo Krummrich &lt;dakr@kernel.org&gt;
Link: https://lore.kernel.org/r/20250624-opaque-from-raw-v2-1-e4da40bdc59c@google.com
Signed-off-by: Miguel Ojeda &lt;ojeda@kernel.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
