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Linus Torvalds e3610441d1 Rust changes for v6.14
Toolchain and infrastructure:
 
  - Finish the move to custom FFI integer types started in the previous
    cycle and finally map 'long' to 'isize' and 'char' to 'u8'. Do a few
    cleanups on top thanks to that.
 
  - Start to use 'derive(CoercePointee)' on Rust >= 1.84.0.
 
    This is a major milestone on the path to build the kernel using only
    stable Rust features. In particular, previously we were using the
    unstable features 'coerce_unsized', 'dispatch_from_dyn' and 'unsize',
    and now we will use the new 'derive_coerce_pointee' one, which is on
    track to stabilization. This new feature is a macro that essentially
    expands into code that internally uses the unstable features that we
    were using before, without having to expose those.
 
    With it, stable Rust users, including the kernel, will be able to
    build custom smart pointers that work with trait objects, e.g.:
 
        fn f(p: &Arc<dyn Display>) {
            pr_info!("{p}\n");
        }
 
        let a: Arc<dyn Display> = Arc::new(42i32, GFP_KERNEL)?;
        let b: Arc<dyn Display> = Arc::new("hello there", GFP_KERNEL)?;
 
        f(&a); // Prints "42".
        f(&b); // Prints "hello there".
 
    Together with the 'arbitrary_self_types' feature that we started
    using in the previous cycle, using our custom smart pointers like
    'Arc' will eventually only rely in stable Rust.
 
  - Introduce 'PROCMACROLDFLAGS' environment variable to allow to link
    Rust proc macros using different flags than those used for linking
    Rust host programs (e.g. when 'rustc' uses a different C library
    than the host programs' one), which Android needs.
 
  - Help kernel builds under macOS with Rust enabled by accomodating
    other naming conventions for dynamic libraries (i.e. '.so' vs.
    '.dylib') which are used for Rust procedural macros. The actual
    support for macOS (i.e. the rest of the pieces needed) is provided
    out-of-tree by others, following the policy used for other parts of
    the kernel by Kbuild.
 
  - Run Clippy for 'rusttest' code too and clean the bits it spotted.
 
  - Provide Clippy with the minimum supported Rust version to improve
    the suggestions it gives.
 
  - Document 'bindgen' 0.71.0 regression.
 
 'kernel' crate:
 
  - 'build_error!': move users of the hidden function to the documented
    macro, prevent such uses in the future by moving the function
    elsewhere and add the macro to the prelude.
 
  - 'types' module: add improved version of 'ForeignOwnable::borrow_mut'
    (which was removed in the past since it was problematic); change
    'ForeignOwnable' pointer type to '*mut'.
 
  - 'alloc' module: implement 'Display' for 'Box' and align the 'Debug'
    implementation to it; add example (doctest) for 'ArrayLayout::new()'.
 
  - 'sync' module: document 'PhantomData' in 'Arc'; use
    'NonNull::new_unchecked' in 'ForeignOwnable for Arc' impl.
 
  - 'uaccess' module: accept 'Vec's with different allocators in
    'UserSliceReader::read_all'.
 
  - 'workqueue' module: enable run-testing a couple more doctests.
 
  - 'error' module: simplify 'from_errno()'.
 
  - 'block' module: fix formatting in code documentation (a lint to catch
    these is being implemented).
 
  - Avoid 'unwrap()'s in doctests, which also improves the examples by
    showing how kernel code is supposed to be written.
 
  - Avoid 'as' casts with 'cast{,_mut}' calls which are a bit safer.
 
 And a few other cleanups.
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Merge tag 'rust-6.14' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux

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

   - Finish the move to custom FFI integer types started in the previous
     cycle and finally map 'long' to 'isize' and 'char' to 'u8'. Do a
     few cleanups on top thanks to that.

   - Start to use 'derive(CoercePointee)' on Rust >= 1.84.0.

     This is a major milestone on the path to build the kernel using
     only stable Rust features. In particular, previously we were using
     the unstable features 'coerce_unsized', 'dispatch_from_dyn' and
     'unsize', and now we will use the new 'derive_coerce_pointee' one,
     which is on track to stabilization. This new feature is a macro
     that essentially expands into code that internally uses the
     unstable features that we were using before, without having to
     expose those.

     With it, stable Rust users, including the kernel, will be able to
     build custom smart pointers that work with trait objects, e.g.:

         fn f(p: &Arc<dyn Display>) {
             pr_info!("{p}\n");
         }

         let a: Arc<dyn Display> = Arc::new(42i32, GFP_KERNEL)?;
         let b: Arc<dyn Display> = Arc::new("hello there", GFP_KERNEL)?;

         f(&a); // Prints "42".
         f(&b); // Prints "hello there".

     Together with the 'arbitrary_self_types' feature that we started
     using in the previous cycle, using our custom smart pointers like
     'Arc' will eventually only rely in stable Rust.

   - Introduce 'PROCMACROLDFLAGS' environment variable to allow to link
     Rust proc macros using different flags than those used for linking
     Rust host programs (e.g. when 'rustc' uses a different C library
     than the host programs' one), which Android needs.

   - Help kernel builds under macOS with Rust enabled by accomodating
     other naming conventions for dynamic libraries (i.e. '.so' vs.
     '.dylib') which are used for Rust procedural macros. The actual
     support for macOS (i.e. the rest of the pieces needed) is provided
     out-of-tree by others, following the policy used for other parts of
     the kernel by Kbuild.

   - Run Clippy for 'rusttest' code too and clean the bits it spotted.

   - Provide Clippy with the minimum supported Rust version to improve
     the suggestions it gives.

   - Document 'bindgen' 0.71.0 regression.

  'kernel' crate:

   - 'build_error!': move users of the hidden function to the documented
     macro, prevent such uses in the future by moving the function
     elsewhere and add the macro to the prelude.

   - 'types' module: add improved version of 'ForeignOwnable::borrow_mut'
     (which was removed in the past since it was problematic); change
     'ForeignOwnable' pointer type to '*mut'.

   - 'alloc' module: implement 'Display' for 'Box' and align the 'Debug'
     implementation to it; add example (doctest) for 'ArrayLayout::new()'

   - 'sync' module: document 'PhantomData' in 'Arc'; use
     'NonNull::new_unchecked' in 'ForeignOwnable for Arc' impl.

   - 'uaccess' module: accept 'Vec's with different allocators in
     'UserSliceReader::read_all'.

   - 'workqueue' module: enable run-testing a couple more doctests.

   - 'error' module: simplify 'from_errno()'.

   - 'block' module: fix formatting in code documentation (a lint to catch
     these is being implemented).

   - Avoid 'unwrap()'s in doctests, which also improves the examples by
     showing how kernel code is supposed to be written.

   - Avoid 'as' casts with 'cast{,_mut}' calls which are a bit safer.

  And a few other cleanups"

* tag 'rust-6.14' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux: (32 commits)
  kbuild: rust: add PROCMACROLDFLAGS
  rust: uaccess: generalize userSliceReader to support any Vec
  rust: kernel: add improved version of `ForeignOwnable::borrow_mut`
  rust: kernel: reorder `ForeignOwnable` items
  rust: kernel: change `ForeignOwnable` pointer to mut
  rust: arc: split unsafe block, add missing comment
  rust: types: avoid `as` casts
  rust: arc: use `NonNull::new_unchecked`
  rust: use derive(CoercePointee) on rustc >= 1.84.0
  rust: alloc: add doctest for `ArrayLayout::new()`
  rust: init: update `stack_try_pin_init` examples
  rust: error: import `kernel`'s `LayoutError` instead of `core`'s
  rust: str: replace unwraps with question mark operators
  rust: page: remove unnecessary helper function from doctest
  rust: rbtree: remove unwrap in asserts
  rust: init: replace unwraps with question mark operators
  rust: use host dylib naming convention to support macOS
  rust: add `build_error!` to the prelude
  rust: kernel: move `build_error` hidden function to prevent mistakes
  rust: use the `build_error!` macro, not the hidden function
  ...
2025-01-21 17:48:03 -08:00
arch Kthreads affinity follow either of 4 existing different patterns: 2025-01-21 17:10:05 -08:00
block for-6.14/io_uring-20250119 2025-01-20 20:27:33 -08:00
certs sign-file,extract-cert: use pkcs11 provider for OPENSSL MAJOR >= 3 2024-09-20 19:52:48 +03:00
crypto Kthreads affinity follow either of 4 existing different patterns: 2025-01-21 17:10:05 -08:00
Documentation Rust changes for v6.14 2025-01-21 17:48:03 -08:00
drivers Rust changes for v6.14 2025-01-21 17:48:03 -08:00
fs Kthreads affinity follow either of 4 existing different patterns: 2025-01-21 17:10:05 -08:00
include Kthreads affinity follow either of 4 existing different patterns: 2025-01-21 17:10:05 -08:00
init Rust changes for v6.14 2025-01-21 17:48:03 -08:00
io_uring for-6.14/io_uring-20250119 2025-01-20 20:27:33 -08:00
ipc - The series "resource: A couple of cleanups" from Andy Shevchenko 2024-11-25 16:09:48 -08:00
kernel Kthreads affinity follow either of 4 existing different patterns: 2025-01-21 17:10:05 -08:00
lib Kthreads affinity follow either of 4 existing different patterns: 2025-01-21 17:10:05 -08:00
LICENSES LICENSES: add 0BSD license text 2024-09-01 20:43:24 -07:00
mm Kthreads affinity follow either of 4 existing different patterns: 2025-01-21 17:10:05 -08:00
net Kthreads affinity follow either of 4 existing different patterns: 2025-01-21 17:10:05 -08:00
rust Rust changes for v6.14 2025-01-21 17:48:03 -08:00
samples Rust changes for v6.14 2025-01-21 17:48:03 -08:00
scripts Rust changes for v6.14 2025-01-21 17:48:03 -08:00
security vfs-6.14-rc1.misc 2025-01-20 09:40:49 -08:00
sound drm next for 6.14-rc1 2025-01-21 16:09:47 -08:00
tools ftrace updates for v6.14: 2025-01-21 15:15:28 -08:00
usr kbuild: Drop support for include/asm-<arch> in headers_check.pl 2024-12-21 11:43:17 +09:00
virt VFIO updates for v6.13 2024-11-27 12:57:03 -08:00
.clang-format clang-format: Update with v6.11-rc1's for_each macro list 2024-08-02 13:20:31 +02:00
.clippy.toml rust: give Clippy the minimum supported Rust version 2025-01-10 00:17:25 +01:00
.cocciconfig
.editorconfig .editorconfig: remove trim_trailing_whitespace option 2024-06-13 16:47:52 +02:00
.get_maintainer.ignore MAINTAINERS: Retire Ralf Baechle 2024-11-12 15:48:59 +01:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore rust: use host dylib naming convention to support macOS 2025-01-10 01:01:24 +01:00
.mailmap 7 singleton hotfixes. 6 are MM. 2 are cc:stable and the remainder 2025-01-16 21:24:34 -08:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: remove Andy Gospodarek from bonding 2025-01-09 08:30:01 -08:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS drm next for 6.14-rc1 2025-01-21 16:09:47 -08:00
Makefile Rust changes for v6.14 2025-01-21 17:48:03 -08:00
README README: Fix spelling 2024-03-18 03:36:32 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.