Commit 784faa8eca82 for kernel

commit 784faa8eca8270671e0ed6d9d21f04bbb80fc5f7
Merge: 51ab33fc0a8b 54e3eae85562
Author: Linus Torvalds <torvalds@linux-foundation.org>
Date:   Wed Dec 3 14:16:49 2025 -0800

    Merge tag 'rust-6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux

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

       - Add support for 'syn'.

         Syn is a parsing library for parsing a stream of Rust tokens into a
         syntax tree of Rust source code.

         Currently this library is geared toward use in Rust procedural
         macros, but contains some APIs that may be useful more generally.

         'syn' allows us to greatly simplify writing complex macros such as
         'pin-init' (Benno has already prepared the 'syn'-based version). We
         will use it in the 'macros' crate too.

         'syn' is the most downloaded Rust crate (according to crates.io),
         and it is also used by the Rust compiler itself. While the amount
         of code is substantial, there should not be many updates needed for
         these crates, and even if there are, they should not be too big,
         e.g. +7k -3k lines across the 3 crates in the last year.

         'syn' requires two smaller dependencies: 'quote' and 'proc-macro2'.
         I only modified their code to remove a third dependency
         ('unicode-ident') and to add the SPDX identifiers. The code can be
         easily verified to exactly match upstream with the provided
         scripts.

         They are all licensed under "Apache-2.0 OR MIT", like the other
         vendored 'alloc' crate we had for a while.

         Please see the merge commit with the cover letter for more context.

       - Allow 'unreachable_pub' and 'clippy::disallowed_names' for
         doctests.

         Examples (i.e. doctests) may want to do things like show public
         items and use names such as 'foo'.

         Nevertheless, we still try to keep examples as close to real code
         as possible (this is part of why running Clippy on doctests is
         important for us, e.g. for safety comments, which userspace Rust
         does not support yet but we are stricter).

      'kernel' crate:

       - Replace our custom 'CStr' type with 'core::ffi::CStr'.

         Using the standard library type reduces our custom code footprint,
         and we retain needed custom functionality through an extension
         trait and a new 'fmt!' macro which replaces the previous 'core'
         import.

         This started in 6.17 and continued in 6.18, and we finally land the
         replacement now. This required quite some stamina from Tamir, who
         split the changes in steps to prepare for the flag day change here.

       - Replace 'kernel::c_str!' with C string literals.

         C string literals were added in Rust 1.77, which produce '&CStr's
         (the 'core' one), so now we can write:

             c"hi"

         instead of:

             c_str!("hi")

       - Add 'num' module for numerical features.

         It includes the 'Integer' trait, implemented for all primitive
         integer types.

         It also includes the 'Bounded' integer wrapping type: an integer
         value that requires only the 'N' least significant bits of the
         wrapped type to be encoded:

             // An unsigned 8-bit integer, of which only the 4 LSBs are used.
             let v = Bounded::<u8, 4>::new::<15>();
             assert_eq!(v.get(), 15);

         'Bounded' is useful to e.g. enforce guarantees when working with
         bitfields that have an arbitrary number of bits.

         Values can also be constructed from simple non-constant expressions
         or, for more complex ones, validated at runtime.

         'Bounded' also comes with comparison and arithmetic operations
         (with both their backing type and other 'Bounded's with a
         compatible backing type), casts to change the backing type,
         extending/shrinking and infallible/fallible conversions from/to
         primitives as applicable.

       - 'rbtree' module: add immutable cursor ('Cursor').

         It enables to use just an immutable tree reference where
         appropriate. The existing fully-featured mutable cursor is renamed
         to 'CursorMut'.

      kallsyms:

       - Fix wrong "big" kernel symbol type read from procfs.

      'pin-init' crate:

       - A couple minor fixes (Benno asked me to pick these patches up for
         him this cycle).

      Documentation:

       - Quick Start guide: add Debian 13 (Trixie).

         Debian Stable is now able to build Linux, since Debian 13 (released
         2025-08-09) packages Rust 1.85.0, which is recent enough.

         We are planning to propose that the minimum supported Rust version
         in Linux follows Debian Stable releases, with Debian 13 being the
         first one we upgrade to, i.e. Rust 1.85.

      MAINTAINERS:

       - Add entry for the new 'num' module.

       - Remove Alex as Rust maintainer: he hasn't had the time to
         contribute for a few years now, so it is a no-op change in
         practice.

      And a few other cleanups and improvements"

    * tag 'rust-6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux: (53 commits)
      rust: macros: support `proc-macro2`, `quote` and `syn`
      rust: syn: enable support in kbuild
      rust: syn: add `README.md`
      rust: syn: remove `unicode-ident` dependency
      rust: syn: add SPDX License Identifiers
      rust: syn: import crate
      rust: quote: enable support in kbuild
      rust: quote: add `README.md`
      rust: quote: add SPDX License Identifiers
      rust: quote: import crate
      rust: proc-macro2: enable support in kbuild
      rust: proc-macro2: add `README.md`
      rust: proc-macro2: remove `unicode_ident` dependency
      rust: proc-macro2: add SPDX License Identifiers
      rust: proc-macro2: import crate
      rust: kbuild: support using libraries in `rustc_procmacro`
      rust: kbuild: support skipping flags in `rustc_test_library`
      rust: kbuild: add proc macro library support
      rust: kbuild: simplify `--cfg` handling
      rust: kbuild: introduce `core-flags` and `core-skip_flags`
      ...

diff --cc rust/kernel/debugfs/traits.rs
index 92054fed2136,ad33bfbc7669..e8a8a98f18dc
--- a/rust/kernel/debugfs/traits.rs
+++ b/rust/kernel/debugfs/traits.rs
@@@ -3,12 -3,15 +3,12 @@@

  //! Traits for rendering or updating values exported to DebugFS.

+ use crate::fmt;
  use crate::prelude::*;
 +use crate::sync::atomic::{Atomic, AtomicBasicOps, AtomicType, Relaxed};
  use crate::sync::Mutex;
  use crate::uaccess::UserSliceReader;
- use core::fmt::{self, Debug, Formatter};
  use core::str::FromStr;
 -use core::sync::atomic::{
 -    AtomicI16, AtomicI32, AtomicI64, AtomicI8, AtomicIsize, AtomicU16, AtomicU32, AtomicU64,
 -    AtomicU8, AtomicUsize, Ordering,
 -};

  /// A trait for types that can be written into a string.
  ///
diff --cc rust/kernel/opp.rs
index f9641c639fff,9d6c58178a6f..a760fac28765
--- a/rust/kernel/opp.rs
+++ b/rust/kernel/opp.rs
@@@ -87,8 -87,8 +87,8 @@@ use core::{marker::PhantomData, ptr}

  use macros::vtable;

 -/// Creates a null-terminated slice of pointers to [`Cstring`]s.
 +/// Creates a null-terminated slice of pointers to [`CString`]s.
- fn to_c_str_array(names: &[CString]) -> Result<KVec<*const u8>> {
+ fn to_c_str_array(names: &[CString]) -> Result<KVec<*const c_char>> {
      // Allocated a null-terminated vector of pointers.
      let mut list = KVec::with_capacity(names.len() + 1, GFP_KERNEL)?;