Merge tag 'rust-6.10' of https://github.com/Rust-for-Linux/linux

Pull Rust updates from Miguel Ojeda:
 "The most notable change is the drop of the 'alloc' in-tree fork. This
  is nicely reflected in the diffstat as a ~10k lines drop. In turn,
  this makes the version upgrades way simpler and smaller in the future,
  e.g. the latest one in commit 56f64b370612 ("rust: upgrade to Rust
  1.78.0").

  More importantly, this increases the chances that a newer compiler
  version just works, which in turn means supporting several compiler
  versions is easier now. Thus we will look into finally setting a
  minimum version in the near future.

  Toolchain and infrastructure:

   - Upgrade to Rust 1.78.0

     This time around, due to how the kernel and Rust schedules have
     aligned, there are two upgrades in fact. These allow us to remove
     one more unstable feature ('offset_of') from the list, among other
     improvements

   - Drop 'alloc' in-tree fork of the standard library crate, which
     means all the unstable features used by 'alloc' (~30 language ones,
     ~60 library ones) are not a concern anymore

   - Support DWARFv5 via the '-Zdwarf-version' flag

   - Support zlib and zstd debuginfo compression via the
     '-Zdebuginfo-compression' flag

  'kernel' crate:

   - Support allocation flags ('GFP_*'), particularly in 'Box' (via
     'BoxExt'), 'Vec' (via 'VecExt'), 'Arc' and 'UniqueArc', as well as
     in the 'init' module APIs

   - Remove usage of the 'allocator_api' unstable feature

   - Remove 'try_' prefix in allocation APIs' names

   - Add 'VecExt' (an extension trait) to be able to drop the 'alloc'
     fork

   - Add the '{make,to}_{upper,lower}case()' methods to 'CStr'/'CString'

   - Add the 'as_ptr' method to 'ThisModule'

   - Add the 'from_raw' method to 'ArcBorrow'

   - Add the 'into_unique_or_drop' method to 'Arc'

   - Display column number in the 'dbg!' macro output by applying the
     equivalent change done to the standard library one

   - Migrate 'Work' to '#[pin_data]' thanks to the changes in the
     'macros' crate, which allows to remove an unsafe call in its 'new'
     associated function

   - Prevent namespacing issues when using the '[try_][pin_]init!'
     macros by changing the generated name of guard variables

   - Make the 'get' method in 'Opaque' const

   - Implement the 'Default' trait for 'LockClassKey'

   - Remove unneeded 'kernel::prelude' imports from doctests

   - Remove redundant imports

  'macros' crate:

   - Add 'decl_generics' to 'parse_generics()' to support default
     values, and use that to allow them in '#[pin_data]'

  Helpers:

   - Trivial English grammar fix

  Documentation:

   - Add section on Rust Kselftests to the 'Testing' document

   - Expand the 'Abstractions vs. bindings' section of the 'General
     Information' document"

* tag 'rust-6.10' of https://github.com/Rust-for-Linux/linux: (31 commits)
  rust: alloc: fix dangling pointer in VecExt<T>::reserve()
  rust: upgrade to Rust 1.78.0
  rust: kernel: remove redundant imports
  rust: sync: implement `Default` for `LockClassKey`
  docs: rust: extend abstraction and binding documentation
  docs: rust: Add instructions for the Rust kselftest
  rust: remove unneeded `kernel::prelude` imports from doctests
  rust: update `dbg!()` to format column number
  rust: helpers: Fix grammar in comment
  rust: init: change the generated name of guard variables
  rust: sync: add `Arc::into_unique_or_drop`
  rust: sync: add `ArcBorrow::from_raw`
  rust: types: Make Opaque::get const
  rust: kernel: remove usage of `allocator_api` unstable feature
  rust: init: update `init` module to take allocation flags
  rust: sync: update `Arc` and `UniqueArc` to take allocation flags
  rust: alloc: update `VecExt` to take allocation flags
  rust: alloc: introduce the `BoxExt` trait
  rust: alloc: introduce allocation flags
  rust: alloc: remove our fork of the `alloc` crate
  ...

43 files changed, 779 insertions, 10032 deletions

diff --git a/rust/Makefile b/rust/Makefile
index 86a125c4243c..eb585ef0e286 100644
--- a/rust/Makefile
+++ b/rust/Makefile
@@ -61,15 +61,9 @@ core-cfgs = \
     --cfg no_fp_fmt_parse
 
 alloc-cfgs = \
-    --cfg no_borrow \
-    --cfg no_fmt \
     --cfg no_global_oom_handling \
-    --cfg no_macros \
     --cfg no_rc \
-    --cfg no_str \
-    --cfg no_string \
-    --cfg no_sync \
-    --cfg no_thin
+    --cfg no_sync
 
 quiet_cmd_rustdoc = RUSTDOC $(if $(rustdoc_host),H, ) $<
       cmd_rustdoc = \
@@ -123,7 +117,7 @@ rustdoc-compiler_builtins: $(src)/compiler_builtins.rs rustdoc-core FORCE
 # due to things that are "configured out" vs. entirely non-existing ones.
 rustdoc-alloc: private rustc_target_flags = $(alloc-cfgs) \
     -Arustdoc::broken_intra_doc_links
-rustdoc-alloc: $(src)/alloc/lib.rs rustdoc-core rustdoc-compiler_builtins FORCE
+rustdoc-alloc: $(RUST_LIB_SRC)/alloc/src/lib.rs rustdoc-core rustdoc-compiler_builtins FORCE
 	+$(call if_changed,rustdoc)
 
 rustdoc-kernel: private rustc_target_flags = --extern alloc \
@@ -218,8 +212,6 @@ rusttest: rusttest-macros rusttest-kernel
 #   - `cargo` only considers the use case of building the standard library
 #     to use it in a given package. Thus we need to create a dummy package
 #     and pick the generated libraries from there.
-#   - Since we only keep a subset of upstream `alloc` in-tree, we need
-#     to recreate it on the fly by putting our sources on top.
 #   - The usual ways of modifying the dependency graph in `cargo` do not seem
 #     to apply for the `-Zbuild-std` steps, thus we have to mislead it
 #     by modifying the sources in the sysroot.
@@ -238,8 +230,6 @@ quiet_cmd_rustsysroot = RUSTSYSROOT
 	rm -rf $(objtree)/$(obj)/test; \
 	mkdir -p $(objtree)/$(obj)/test; \
 	cp -a $(rustc_sysroot) $(objtree)/$(obj)/test/sysroot; \
-	cp -r $(srctree)/$(src)/alloc/* \
-		$(objtree)/$(obj)/test/sysroot/lib/rustlib/src/rust/library/alloc/src; \
 	echo '\#!/bin/sh' > $(objtree)/$(obj)/test/rustc_sysroot; \
 	echo "$(RUSTC) --sysroot=$(abspath $(objtree)/$(obj)/test/sysroot) \"\$$@\"" \
 		>> $(objtree)/$(obj)/test/rustc_sysroot; \
@@ -447,7 +437,7 @@ $(obj)/compiler_builtins.o: $(src)/compiler_builtins.rs $(obj)/core.o FORCE
 $(obj)/alloc.o: private skip_clippy = 1
 $(obj)/alloc.o: private skip_flags = -Dunreachable_pub
 $(obj)/alloc.o: private rustc_target_flags = $(alloc-cfgs)
-$(obj)/alloc.o: $(src)/alloc/lib.rs $(obj)/compiler_builtins.o FORCE
+$(obj)/alloc.o: $(RUST_LIB_SRC)/alloc/src/lib.rs $(obj)/compiler_builtins.o FORCE
 	+$(call if_changed_dep,rustc_library)
 
 $(obj)/build_error.o: $(src)/build_error.rs $(obj)/compiler_builtins.o FORCE
diff --git a/rust/alloc/README.md b/rust/alloc/README.md
deleted file mode 100644
index eb6f22e94ebf..000000000000
--- a/rust/alloc/README.md
+++ /dev/null
@@ -1,36 +0,0 @@
-# `alloc`
-
-These source files come from the Rust standard library, hosted in
-the <https://github.com/rust-lang/rust> repository, licensed under
-"Apache-2.0 OR MIT" and adapted for kernel use. For copyright details,
-see <https://github.com/rust-lang/rust/blob/master/COPYRIGHT>.
-
-Please note that these files should be kept as close as possible to
-upstream. In general, only additions should be performed (e.g. new
-methods). Eventually, changes should make it into upstream so that,
-at some point, this fork can be dropped from the kernel tree.
-
-The Rust upstream version on top of which these files are based matches
-the output of `scripts/min-tool-version.sh rustc`.
-
-
-## Rationale
-
-On one hand, kernel folks wanted to keep `alloc` in-tree to have more
-freedom in both workflow and actual features if actually needed
-(e.g. receiver types if we ended up using them), which is reasonable.
-
-On the other hand, Rust folks wanted to keep `alloc` as close as
-upstream as possible and avoid as much divergence as possible, which
-is also reasonable.
-
-We agreed on a middle-ground: we would keep a subset of `alloc`
-in-tree that would be as small and as close as possible to upstream.
-Then, upstream can start adding the functions that we add to `alloc`
-etc., until we reach a point where the kernel already knows exactly
-what it needs in `alloc` and all the new methods are merged into
-upstream, so that we can drop `alloc` from the kernel tree and go back
-to using the upstream one.
-
-By doing this, the kernel can go a bit faster now, and Rust can
-slowly incorporate and discuss the changes as needed.
diff --git a/rust/alloc/alloc.rs b/rust/alloc/alloc.rs
deleted file mode 100644
index abb791cc2371..000000000000
--- a/rust/alloc/alloc.rs
+++ /dev/null
@@ -1,452 +0,0 @@
-// SPDX-License-Identifier: Apache-2.0 OR MIT
-
-//! Memory allocation APIs
-
-#![stable(feature = "alloc_module", since = "1.28.0")]
-
-#[cfg(not(test))]
-use core::intrinsics;
-
-#[cfg(not(test))]
-use core::ptr::{self, NonNull};
-
-#[stable(feature = "alloc_module", since = "1.28.0")]
-#[doc(inline)]
-pub use core::alloc::*;
-
-#[cfg(test)]
-mod tests;
-
-extern "Rust" {
-    // These are the magic symbols to call the global allocator. rustc generates
-    // them to call `__rg_alloc` etc. if there is a `#[global_allocator]` attribute
-    // (the code expanding that attribute macro generates those functions), or to call
-    // the default implementations in std (`__rdl_alloc` etc. in `library/std/src/alloc.rs`)
-    // otherwise.
-    // The rustc fork of LLVM 14 and earlier also special-cases these function names to be able to optimize them
-    // like `malloc`, `realloc`, and `free`, respectively.
-    #[rustc_allocator]
-    #[rustc_nounwind]
-    fn __rust_alloc(size: usize, align: usize) -> *mut u8;
-    #[rustc_deallocator]
-    #[rustc_nounwind]
-    fn __rust_dealloc(ptr: *mut u8, size: usize, align: usize);
-    #[rustc_reallocator]
-    #[rustc_nounwind]
-    fn __rust_realloc(ptr: *mut u8, old_size: usize, align: usize, new_size: usize) -> *mut u8;
-    #[rustc_allocator_zeroed]
-    #[rustc_nounwind]
-    fn __rust_alloc_zeroed(size: usize, align: usize) -> *mut u8;
-
-    static __rust_no_alloc_shim_is_unstable: u8;
-}
-
-/// The global memory allocator.
-///
-/// This type implements the [`Allocator`] trait by forwarding calls
-/// to the allocator registered with the `#[global_allocator]` attribute
-/// if there is one, or the `std` crate’s default.
-///
-/// Note: while this type is unstable, the functionality it provides can be
-/// accessed through the [free functions in `alloc`](self#functions).
-#[unstable(feature = "allocator_api", issue = "32838")]
-#[derive(Copy, Clone, Default, Debug)]
-#[cfg(not(test))]
-pub struct Global;
-
-#[cfg(test)]
-pub use std::alloc::Global;
-
-/// Allocate memory with the global allocator.
-///
-/// This function forwards calls to the [`GlobalAlloc::alloc`] method
-/// of the allocator registered with the `#[global_allocator]` attribute
-/// if there is one, or the `std` crate’s default.
-///
-/// This function is expected to be deprecated in favor of the `alloc` method
-/// of the [`Global`] type when it and the [`Allocator`] trait become stable.
-///
-/// # Safety
-///
-/// See [`GlobalAlloc::alloc`].
-///
-/// # Examples
-///
-/// ```
-/// use std::alloc::{alloc, dealloc, handle_alloc_error, Layout};
-///
-/// unsafe {
-///     let layout = Layout::new::<u16>();
-///     let ptr = alloc(layout);
-///     if ptr.is_null() {
-///         handle_alloc_error(layout);
-///     }
-///
-///     *(ptr as *mut u16) = 42;
-///     assert_eq!(*(ptr as *mut u16), 42);
-///
-///     dealloc(ptr, layout);
-/// }
-/// ```
-#[stable(feature = "global_alloc", since = "1.28.0")]
-#[must_use = "losing the pointer will leak memory"]
-#[inline]
-pub unsafe fn alloc(layout: Layout) -> *mut u8 {
-    unsafe {
-        // Make sure we don't accidentally allow omitting the allocator shim in
-        // stable code until it is actually stabilized.
-        core::ptr::read_volatile(&__rust_no_alloc_shim_is_unstable);
-
-        __rust_alloc(layout.size(), layout.align())
-    }
-}
-
-/// Deallocate memory with the global allocator.
-///
-/// This function forwards calls to the [`GlobalAlloc::dealloc`] method
-/// of the allocator registered with the `#[global_allocator]` attribute
-/// if there is one, or the `std` crate’s default.
-///
-/// This function is expected to be deprecated in favor of the `dealloc` method
-/// of the [`Global`] type when it and the [`Allocator`] trait become stable.
-///
-/// # Safety
-///
-/// See [`GlobalAlloc::dealloc`].
-#[stable(feature = "global_alloc", since = "1.28.0")]
-#[inline]
-pub unsafe fn dealloc(ptr: *mut u8, layout: Layout) {
-    unsafe { __rust_dealloc(ptr, layout.size(), layout.align()) }
-}
-
-/// Reallocate memory with the global allocator.
-///
-/// This function forwards calls to the [`GlobalAlloc::realloc`] method
-/// of the allocator registered with the `#[global_allocator]` attribute
-/// if there is one, or the `std` crate’s default.
-///
-/// This function is expected to be deprecated in favor of the `realloc` method
-/// of the [`Global`] type when it and the [`Allocator`] trait become stable.
-///
-/// # Safety
-///
-/// See [`GlobalAlloc::realloc`].
-#[stable(feature = "global_alloc", since = "1.28.0")]
-#[must_use = "losing the pointer will leak memory"]
-#[inline]
-pub unsafe fn realloc(ptr: *mut u8, layout: Layout, new_size: usize) -> *mut u8 {
-    unsafe { __rust_realloc(ptr, layout.size(), layout.align(), new_size) }
-}
-
-/// Allocate zero-initialized memory with the global allocator.
-///
-/// This function forwards calls to the [`GlobalAlloc::alloc_zeroed`] method
-/// of the allocator registered with the `#[global_allocator]` attribute
-/// if there is one, or the `std` crate’s default.
-///
-/// This function is expected to be deprecated in favor of the `alloc_zeroed` method
-/// of the [`Global`] type when it and the [`Allocator`] trait become stable.
-///
-/// # Safety
-///
-/// See [`GlobalAlloc::alloc_zeroed`].
-///
-/// # Examples
-///
-/// ```
-/// use std::alloc::{alloc_zeroed, dealloc, Layout};
-///
-/// unsafe {
-///     let layout = Layout::new::<u16>();
-///     let ptr = alloc_zeroed(layout);
-///
-///     assert_eq!(*(ptr as *mut u16), 0);
-///
-///     dealloc(ptr, layout);
-/// }
-/// ```
-#[stable(feature = "global_alloc", since = "1.28.0")]
-#[must_use = "losing the pointer will leak memory"]
-#[inline]
-pub unsafe fn alloc_zeroed(layout: Layout) -> *mut u8 {
-    unsafe { __rust_alloc_zeroed(layout.size(), layout.align()) }
-}
-
-#[cfg(not(test))]
-impl Global {
-    #[inline]
-    fn alloc_impl(&self, layout: Layout, zeroed: bool) -> Result<NonNull<[u8]>, AllocError> {
-        match layout.size() {
-            0 => Ok(NonNull::slice_from_raw_parts(layout.dangling(), 0)),
-            // SAFETY: `layout` is non-zero in size,
-            size => unsafe {
-                let raw_ptr = if zeroed { alloc_zeroed(layout) } else { alloc(layout) };
-                let ptr = NonNull::new(raw_ptr).ok_or(AllocError)?;
-                Ok(NonNull::slice_from_raw_parts(ptr, size))
-            },
-        }
-    }
-
-    // SAFETY: Same as `Allocator::grow`
-    #[inline]
-    unsafe fn grow_impl(
-        &self,
-        ptr: NonNull<u8>,
-        old_layout: Layout,
-        new_layout: Layout,
-        zeroed: bool,
-    ) -> Result<NonNull<[u8]>, AllocError> {
-        debug_assert!(
-            new_layout.size() >= old_layout.size(),
-            "`new_layout.size()` must be greater than or equal to `old_layout.size()`"
-        );
-
-        match old_layout.size() {
-            0 => self.alloc_impl(new_layout, zeroed),
-
-            // SAFETY: `new_size` is non-zero as `old_size` is greater than or equal to `new_size`
-            // as required by safety conditions. Other conditions must be upheld by the caller
-            old_size if old_layout.align() == new_layout.align() => unsafe {
-                let new_size = new_layout.size();
-
-                // `realloc` probably checks for `new_size >= old_layout.size()` or something similar.
-                intrinsics::assume(new_size >= old_layout.size());
-
-                let raw_ptr = realloc(ptr.as_ptr(), old_layout, new_size);
-                let ptr = NonNull::new(raw_ptr).ok_or(AllocError)?;
-                if zeroed {
-                    raw_ptr.add(old_size).write_bytes(0, new_size - old_size);
-                }
-                Ok(NonNull::slice_from_raw_parts(ptr, new_size))
-            },
-
-            // SAFETY: because `new_layout.size()` must be greater than or equal to `old_size`,
-            // both the old and new memory allocation are valid for reads and writes for `old_size`
-            // bytes. Also, because the old allocation wasn't yet deallocated, it cannot overlap
-            // `new_ptr`. Thus, the call to `copy_nonoverlapping` is safe. The safety contract
-            // for `dealloc` must be upheld by the caller.
-            old_size => unsafe {
-                let new_ptr = self.alloc_impl(new_layout, zeroed)?;
-                ptr::copy_nonoverlapping(ptr.as_ptr(), new_ptr.as_mut_ptr(), old_size);
-                self.deallocate(ptr, old_layout);
-                Ok(new_ptr)
-            },
-        }
-    }
-}
-
-#[unstable(feature = "allocator_api", issue = "32838")]
-#[cfg(not(test))]
-unsafe impl Allocator for Global {
-    #[inline]
-    fn allocate(&self, layout: Layout) -> Result<NonNull<[u8]>, AllocError> {
-        self.alloc_impl(layout, false)
-    }
-
-    #[inline]
-    fn allocate_zeroed(&self, layout: Layout) -> Result<NonNull<[u8]>, AllocError> {
-        self.alloc_impl(layout, true)
-    }
-
-    #[inline]
-    unsafe fn deallocate(&self, ptr: NonNull<u8>, layout: Layout) {
-        if layout.size() != 0 {
-            // SAFETY: `layout` is non-zero in size,
-            // other conditions must be upheld by the caller
-            unsafe { dealloc(ptr.as_ptr(), layout) }
-        }
-    }
-
-    #[inline]
-    unsafe fn grow(
-        &self,
-        ptr: NonNull<u8>,
-        old_layout: Layout,
-        new_layout: Layout,
-    ) -> Result<NonNull<[u8]>, AllocError> {
-        // SAFETY: all conditions must be upheld by the caller
-        unsafe { self.grow_impl(ptr, old_layout, new_layout, false) }
-    }
-
-    #[inline]
-    unsafe fn grow_zeroed(
-        &self,
-        ptr: NonNull<u8>,
-        old_layout: Layout,
-        new_layout: Layout,
-    ) -> Result<NonNull<[u8]>, AllocError> {
-        // SAFETY: all conditions must be upheld by the caller
-        unsafe { self.grow_impl(ptr, old_layout, new_layout, true) }
-    }
-
-    #[inline]
-    unsafe fn shrink(
-        &self,
-        ptr: NonNull<u8>,
-        old_layout: Layout,
-        new_layout: Layout,
-    ) -> Result<NonNull<[u8]>, AllocError> {
-        debug_assert!(
-            new_layout.size() <= old_layout.size(),
-            "`new_layout.size()` must be smaller than or equal to `old_layout.size()`"
-        );
-
-        match new_layout.size() {
-            // SAFETY: conditions must be upheld by the caller
-            0 => unsafe {
-                self.deallocate(ptr, old_layout);
-                Ok(NonNull::slice_from_raw_parts(new_layout.dangling(), 0))
-            },
-
-            // SAFETY: `new_size` is non-zero. Other conditions must be upheld by the caller
-            new_size if old_layout.align() == new_layout.align() => unsafe {
-                // `realloc` probably checks for `new_size <= old_layout.size()` or something similar.
-                intrinsics::assume(new_size <= old_layout.size());
-
-                let raw_ptr = realloc(ptr.as_ptr(), old_layout, new_size);
-                let ptr = NonNull::new(raw_ptr).ok_or(AllocError)?;
-                Ok(NonNull::slice_from_raw_parts(ptr, new_size))
-            },
-
-            // SAFETY: because `new_size` must be smaller than or equal to `old_layout.size()`,
-            // both the old and new memory allocation are valid for reads and writes for `new_size`
-            // bytes. Also, because the old allocation wasn't yet deallocated, it cannot overlap
-            // `new_ptr`. Thus, the call to `copy_nonoverlapping` is safe. The safety contract
-            // for `dealloc` must be upheld by the caller.
-            new_size => unsafe {
-                let new_ptr = self.allocate(new_layout)?;
-                ptr::copy_nonoverlapping(ptr.as_ptr(), new_ptr.as_mut_ptr(), new_size);
-                self.deallocate(ptr, old_layout);
-                Ok(new_ptr)
-            },
-        }
-    }
-}
-
-/// The allocator for unique pointers.
-#[cfg(all(not(no_global_oom_handling), not(test)))]
-#[lang = "exchange_malloc"]
-#[inline]
-unsafe fn exchange_malloc(size: usize, align: usize) -> *mut u8 {
-    let layout = unsafe { Layout::from_size_align_unchecked(size, align) };
-    match Global.allocate(layout) {
-        Ok(ptr) => ptr.as_mut_ptr(),
-        Err(_) => handle_alloc_error(layout),
-    }
-}
-
-// # Allocation error handler
-
-#[cfg(not(no_global_oom_handling))]
-extern "Rust" {
-    // This is the magic symbol to call the global alloc error handler. rustc generates
-    // it to call `__rg_oom` if there is a `#[alloc_error_handler]`, or to call the
-    // default implementations below (`__rdl_oom`) otherwise.
-    fn __rust_alloc_error_handler(size: usize, align: usize) -> !;
-}
-
-/// Signal a memory allocation error.
-///
-/// Callers of memory allocation APIs wishing to cease execution
-/// in response to an allocation error are encouraged to call this function,
-/// rather than directly invoking [`panic!`] or similar.
-///
-/// This function is guaranteed to diverge (not return normally with a value), but depending on
-/// global configuration, it may either panic (resulting in unwinding or aborting as per
-/// configuration for all panics), or abort the process (with no unwinding).
-///
-/// The default behavior is:
-///
-///  * If the binary links against `std` (typically the case), then
-///   print a message to standard error and abort the process.
-///   This behavior can be replaced with [`set_alloc_error_hook`] and [`take_alloc_error_hook`].
-///   Future versions of Rust may panic by default instead.
-///
-/// * If the binary does not link against `std` (all of its crates are marked
-///   [`#![no_std]`][no_std]), then call [`panic!`] with a message.
-///   [The panic handler] applies as to any panic.
-///
-/// [`set_alloc_error_hook`]: ../../std/alloc/fn.set_alloc_error_hook.html
-/// [`take_alloc_error_hook`]: ../../std/alloc/fn.take_alloc_error_hook.html
-/// [The panic handler]: https://doc.rust-lang.org/reference/runtime.html#the-panic_handler-attribute
-/// [no_std]: https://doc.rust-lang.org/reference/names/preludes.html#the-no_std-attribute
-#[stable(feature = "global_alloc", since = "1.28.0")]
-#[rustc_const_unstable(feature = "const_alloc_error", issue = "92523")]
-#[cfg(all(not(no_global_oom_handling), not(test)))]
-#[cold]
-pub const fn handle_alloc_error(layout: Layout) -> ! {
-    const fn ct_error(_: Layout) -> ! {
-        panic!("allocation failed");
-    }
-
-    #[inline]
-    fn rt_error(layout: Layout) -> ! {
-        unsafe {
-            __rust_alloc_error_handler(layout.size(), layout.align());
-        }
-    }
-
-    #[cfg(not(feature = "panic_immediate_abort"))]
-    unsafe {
-        core::intrinsics::const_eval_select((layout,), ct_error, rt_error)
-    }
-
-    #[cfg(feature = "panic_immediate_abort")]
-    ct_error(layout)
-}
-
-// For alloc test `std::alloc::handle_alloc_error` can be used directly.
-#[cfg(all(not(no_global_oom_handling), test))]
-pub use std::alloc::handle_alloc_error;
-
-#[cfg(all(not(no_global_oom_handling), not(test)))]
-#[doc(hidden)]
-#[allow(unused_attributes)]
-#[unstable(feature = "alloc_internals", issue = "none")]
-pub mod __alloc_error_handler {
-    // called via generated `__rust_alloc_error_handler` if there is no
-    // `#[alloc_error_handler]`.
-    #[rustc_std_internal_symbol]
-    pub unsafe fn __rdl_oom(size: usize, _align: usize) -> ! {
-        extern "Rust" {
-            // This symbol is emitted by rustc next to __rust_alloc_error_handler.
-            // Its value depends on the -Zoom={panic,abort} compiler option.
-            static __rust_alloc_error_handler_should_panic: u8;
-        }
-
-        if unsafe { __rust_alloc_error_handler_should_panic != 0 } {
-            panic!("memory allocation of {size} bytes failed")
-        } else {
-            core::panicking::panic_nounwind_fmt(
-                format_args!("memory allocation of {size} bytes failed"),
-                /* force_no_backtrace */ false,
-            )
-        }
-    }
-}
-
-#[cfg(not(no_global_oom_handling))]
-/// Specialize clones into pre-allocated, uninitialized memory.
-/// Used by `Box::clone` and `Rc`/`Arc::make_mut`.
-pub(crate) trait WriteCloneIntoRaw: Sized {
-    unsafe fn write_clone_into_raw(&self, target: *mut Self);
-}
-
-#[cfg(not(no_global_oom_handling))]
-impl<T: Clone> WriteCloneIntoRaw for T {
-    #[inline]
-    default unsafe fn write_clone_into_raw(&self, target: *mut Self) {
-        // Having allocated *first* may allow the optimizer to create
-        // the cloned value in-place, skipping the local and move.
-        unsafe { target.write(self.clone()) };
-    }
-}
-
-#[cfg(not(no_global_oom_handling))]
-impl<T: Copy> WriteCloneIntoRaw for T {
-    #[inline]
-    unsafe fn write_clone_into_raw(&self, target: *mut Self) {
-        // We can always copy in-place, without ever involving a local value.
-        unsafe { target.copy_from_nonoverlapping(self, 1) };
-    }
-}
diff --git a/rust/alloc/boxed.rs b/rust/alloc/boxed.rs
deleted file mode 100644
index c93a22a5c97f..000000000000
--- a/rust/alloc/boxed.rs
+++ /dev/null
@@ -1,2463 +0,0 @@
-// SPDX-License-Identifier: Apache-2.0 OR MIT
-
-//! The `Box<T>` type for heap allocation.
-//!
-//! [`Box<T>`], casually referred to as a 'box', provides the simplest form of
-//! heap allocation in Rust. Boxes provide ownership for this allocation, and