Merge tag 'rust-6.12' of https://github.com/Rust-for-Linux/linux

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

   - Support 'MITIGATION_{RETHUNK,RETPOLINE,SLS}' (which cleans up
     objtool warnings), teach objtool about 'noreturn' Rust symbols and
     mimic '___ADDRESSABLE()' for 'module_{init,exit}'. With that, we
     should be objtool-warning-free, so enable it to run for all Rust
     object files.

   - KASAN (no 'SW_TAGS'), KCFI and shadow call sanitizer support.

   - Support 'RUSTC_VERSION', including re-config and re-build on
     change.

   - Split helpers file into several files in a folder, to avoid
     conflicts in it. Eventually those files will be moved to the right
     places with the new build system. In addition, remove the need to
     manually export the symbols defined there, reusing existing
     machinery for that.

   - Relax restriction on configurations with Rust + GCC plugins to just
     the RANDSTRUCT plugin.

  'kernel' crate:

   - New 'list' module: doubly-linked linked list for use with reference
     counted values, which is heavily used by the upcoming Rust Binder.

     This includes 'ListArc' (a wrapper around 'Arc' that is guaranteed
     unique for the given ID), 'AtomicTracker' (tracks whether a
     'ListArc' exists using an atomic), 'ListLinks' (the prev/next
     pointers for an item in a linked list), 'List' (the linked list
     itself), 'Iter' (an iterator over a 'List'), 'Cursor' (a cursor
     into a 'List' that allows to remove elements), 'ListArcField' (a
     field exclusively owned by a 'ListArc'), as well as support for
     heterogeneous lists.

   - New 'rbtree' module: red-black tree abstractions used by the
     upcoming Rust Binder.

     This includes 'RBTree' (the red-black tree itself), 'RBTreeNode' (a
     node), 'RBTreeNodeReservation' (a memory reservation for a node),
     'Iter' and 'IterMut' (immutable and mutable iterators), 'Cursor'
     (bidirectional cursor that allows to remove elements), as well as
     an entry API similar to the Rust standard library one.

   - 'init' module: add 'write_[pin_]init' methods and the
     'InPlaceWrite' trait. Add the 'assert_pinned!' macro.

   - 'sync' module: implement the 'InPlaceInit' trait for 'Arc' by
     introducing an associated type in the trait.

   - 'alloc' module: add 'drop_contents' method to 'BoxExt'.

   - 'types' module: implement the 'ForeignOwnable' trait for
     'Pin<Box<T>>' and improve the trait's documentation. In addition,
     add the 'into_raw' method to the 'ARef' type.

   - 'error' module: in preparation for the upcoming Rust support for
     32-bit architectures, like arm, locally allow Clippy lint for
     those.

  Documentation:

   - https://rust.docs.kernel.org has been announced, so link to it.

   - Enable rustdoc's "jump to definition" feature, making its output a
     bit closer to the experience in a cross-referencer.

   - Debian Testing now also provides recent Rust releases (outside of
     the freeze period), so add it to the list.

  MAINTAINERS:

   - Trevor is joining as reviewer of the "RUST" entry.

  And a few other small bits"

* tag 'rust-6.12' of https://github.com/Rust-for-Linux/linux: (54 commits)
  kasan: rust: Add KASAN smoke test via UAF
  kbuild: rust: Enable KASAN support
  rust: kasan: Rust does not support KHWASAN
  kbuild: rust: Define probing macros for rustc
  kasan: simplify and clarify Makefile
  rust: cfi: add support for CFI_CLANG with Rust
  cfi: add CONFIG_CFI_ICALL_NORMALIZE_INTEGERS
  rust: support for shadow call stack sanitizer
  docs: rust: include other expressions in conditional compilation section
  kbuild: rust: replace proc macros dependency on `core.o` with the version text
  kbuild: rust: rebuild if the version text changes
  kbuild: rust: re-run Kconfig if the version text changes
  kbuild: rust: add `CONFIG_RUSTC_VERSION`
  rust: avoid `box_uninit_write` feature
  MAINTAINERS: add Trevor Gross as Rust reviewer
  rust: rbtree: add `RBTree::entry`
  rust: rbtree: add cursor
  rust: rbtree: add mutable iterator
  rust: rbtree: add iterator
  rust: rbtree: add red-black tree implementation backed by the C version
  ...

3 files changed, 40 insertions, 9 deletions

diff --git a/Documentation/rust/general-information.rst b/Documentation/rust/general-information.rst
index e3f388ef4ee4..6146b49b6a98 100644
--- a/Documentation/rust/general-information.rst
+++ b/Documentation/rust/general-information.rst
@@ -15,6 +15,8 @@ but not `std <https://doc.rust-lang.org/std/>`_. Crates for use in the
 kernel must opt into this behavior using the ``#![no_std]`` attribute.
 
 
+.. _rust_code_documentation:
+
 Code documentation
 ------------------
 
@@ -22,10 +24,17 @@ Rust kernel code is documented using ``rustdoc``, its built-in documentation
 generator.
 
 The generated HTML docs include integrated search, linked items (e.g. types,
-functions, constants), source code, etc. They may be read at (TODO: link when
-in mainline and generated alongside the rest of the documentation):
+functions, constants), source code, etc. They may be read at:
+
+	https://rust.docs.kernel.org
+
+For linux-next, please see:
+
+	https://rust.docs.kernel.org/next/
 
-	http://kernel.org/
+There are also tags for each main release, e.g.:
+
+	https://rust.docs.kernel.org/6.10/
 
 The docs can also be easily generated and read locally. This is quite fast
 (same order as compiling the code itself) and no special tools or environment
@@ -75,7 +84,7 @@ should provide as-safe-as-possible abstractions as needed.
 .. code-block::
 
 	                                                rust/bindings/
-	                                               (rust/helpers.c)
+	                                               (rust/helpers/)
 
 	                                                   include/ -----+ <-+
 	                                                                 |   |
@@ -112,7 +121,7 @@ output files in the ``rust/bindings/`` directory.
 
 For parts of the C header that ``bindgen`` does not auto generate, e.g. C
 ``inline`` functions or non-trivial macros, it is acceptable to add a small
-wrapper function to ``rust/helpers.c`` to make it available for the Rust side as
+wrapper function to ``rust/helpers/`` to make it available for the Rust side as
 well.
 
 Abstractions
@@ -142,3 +151,11 @@ configuration:
 	#[cfg(CONFIG_X="y")]   // Enabled as a built-in (`y`)
 	#[cfg(CONFIG_X="m")]   // Enabled as a module   (`m`)
 	#[cfg(not(CONFIG_X))]  // Disabled
+
+For other predicates that Rust's ``cfg`` does not support, e.g. expressions with
+numerical comparisons, one may define a new Kconfig symbol:
+
+.. code-block:: kconfig
+
+	config RUSTC_VERSION_MIN_107900
+		def_bool y if RUSTC_VERSION >= 107900
diff --git a/Documentation/rust/index.rst b/Documentation/rust/index.rst
index 46d35bd395cf..55dcde9e9e7e 100644
--- a/Documentation/rust/index.rst
+++ b/Documentation/rust/index.rst
@@ -25,13 +25,27 @@ support is still in development/experimental, especially for certain kernel
 configurations.
 
 
+Code documentation
+------------------
+
+Given a kernel configuration, the kernel may generate Rust code documentation,
+i.e. HTML rendered by the ``rustdoc`` tool.
+
 .. only:: rustdoc and html
 
-	You can also browse `rustdoc documentation <rustdoc/kernel/index.html>`_.
+	This kernel documentation was built with `Rust code documentation
+	<rustdoc/kernel/index.html>`_.
 
 .. only:: not rustdoc and html
 
-	This documentation does not include rustdoc generated information.
+	This kernel documentation was not built with Rust code documentation.
+
+A pregenerated version is provided at:
+
+	https://rust.docs.kernel.org
+
+Please see the :ref:`Code documentation <rust_code_documentation>` section for
+more details.
 
 .. toctree::
     :maxdepth: 1
diff --git a/Documentation/rust/quick-start.rst b/Documentation/rust/quick-start.rst
index 8e3ad9678719..2d107982c87b 100644
--- a/Documentation/rust/quick-start.rst
+++ b/Documentation/rust/quick-start.rst
@@ -39,8 +39,8 @@ of the box, e.g.::
 Debian
 ******
 
-Debian Unstable (Sid), outside of the freeze period, provides recent Rust
-releases and thus it should generally work out of the box, e.g.::
+Debian Testing and Debian Unstable (Sid), outside of the freeze period, provide
+recent Rust releases and thus they should generally work out of the box, e.g.::
 
 	apt install rustc rust-src bindgen rustfmt rust-clippy