Merge tag 'rust-6.6' of https://github.com/Rust-for-Linux/linux

Pull rust updates from Miguel Ojeda:
 "In terms of lines, most changes this time are on the pinned-init API
  and infrastructure. While we have a Rust version upgrade, and thus a
  bunch of changes from the vendored 'alloc' crate as usual, this time
  those do not account for many lines.

  Toolchain and infrastructure:

   - Upgrade to Rust 1.71.1. This is the second such upgrade, which is a
     smaller jump compared to the last time.

     This version allows us to remove the '__rust_*' allocator functions
     -- the compiler now generates them as expected, thus now our
     'KernelAllocator' is used.

     It also introduces the 'offset_of!' macro in the standard library
     (as an unstable feature) which we will need soon. So far, we were
     using a declarative macro as a prerequisite in some not-yet-landed
     patch series, which did not support sub-fields (i.e. nested
     structs):

         #[repr(C)]
         struct S {
             a: u16,
             b: (u8, u8),
         }

         assert_eq!(offset_of!(S, b.1), 3);

   - Upgrade to bindgen 0.65.1. This is the first time we upgrade its
     version.

     Given it is a fairly big jump, it comes with a fair number of
     improvements/changes that affect us, such as a fix needed to
     support LLVM 16 as well as proper support for '__noreturn' C
     functions, which are now mapped to return the '!' type in Rust:

         void __noreturn f(void); // C
         pub fn f() -> !;         // Rust

   - 'scripts/rust_is_available.sh' improvements and fixes.

     This series takes care of all the issues known so far and adds a
     few new checks to cover for even more cases, plus adds some more
     help texts. All this together will hopefully make problematic
     setups easier to identify and to be solved by users building the
     kernel.

     In addition, it adds a test suite which covers all branches of the
     shell script, as well as tests for the issues found so far.

   - Support rust-analyzer for out-of-tree modules too.

   - Give 'cfg's to rust-analyzer for the 'core' and 'alloc' crates.

   - Drop 'scripts/is_rust_module.sh' since it is not needed anymore.

  Macros crate:

   - New 'paste!' proc macro.

     This macro is a more flexible version of 'concat_idents!': it
     allows the resulting identifier to be used to declare new items and
     it allows to transform the identifiers before concatenating them,
     e.g.

         let x_1 = 42;
         paste!(let [<x _2>] = [<x _1>];);
         assert!(x_1 == x_2);

     The macro is then used for several of the pinned-init API changes
     in this pull.

  Pinned-init API:

   - Make '#[pin_data]' compatible with conditional compilation of
     fields, allowing to write code like:

         #[pin_data]
         pub struct Foo {
             #[cfg(CONFIG_BAR)]
             a: Bar,
             #[cfg(not(CONFIG_BAR))]
             a: Baz,
         }

   - New '#[derive(Zeroable)]' proc macro for the 'Zeroable' trait,
     which allows 'unsafe' implementations for structs where every field
     implements the 'Zeroable' trait, e.g.:

         #[derive(Zeroable)]
         pub struct DriverData {
             id: i64,
             buf_ptr: *mut u8,
             len: usize,
         }

   - Add '..Zeroable::zeroed()' syntax to the 'pin_init!' macro for
     zeroing all other fields, e.g.:

         pin_init!(Buf {
             buf: [1; 64],
             ..Zeroable::zeroed()
         });

   - New '{,pin_}init_array_from_fn()' functions to create array
     initializers given a generator function, e.g.:

         let b: Box<[usize; 1_000]> = Box::init::<Error>(
             init_array_from_fn(|i| i)
         ).unwrap();

         assert_eq!(b.len(), 1_000);
         assert_eq!(b[123], 123);

   - New '{,pin_}chain' methods for '{,Pin}Init<T, E>' that allow to
     execute a closure on the value directly after initialization, e.g.:

         let foo = init!(Foo {
             buf <- init::zeroed()
         }).chain(|foo| {
             foo.setup();
             Ok(())
         });

   - Support arbitrary paths in init macros, instead of just identifiers
     and generic types.

   - Implement the 'Zeroable' trait for the 'UnsafeCell<T>' and
     'Opaque<T>' types.

   - Make initializer values inaccessible after initialization.

   - Make guards in the init macros hygienic.

  'allocator' module:

   - Use 'krealloc_aligned()' in 'KernelAllocator::alloc' preventing
     misaligned allocations when the Rust 1.71.1 upgrade is applied
     later in this pull.

     The equivalent fix for the previous compiler version (where
     'KernelAllocator' is not yet used) was merged into 6.5 already,
     which added the 'krealloc_aligned()' function used here.

   - Implement 'KernelAllocator::{realloc, alloc_zeroed}' for
     performance, using 'krealloc_aligned()' too, which forwards the
     call to the C API.

  'types' module:

   - Make 'Opaque' be '!Unpin', removing the need to add a
     'PhantomPinned' field to Rust structs that contain C structs which
     must not be moved.

   - Make 'Opaque' use 'UnsafeCell' as the outer type, rather than
     inner.

  Documentation:

   - Suggest obtaining the source code of the Rust's 'core' library
     using the tarball instead of the repository.

  MAINTAINERS:

   - Andreas and Alice, from Samsung and Google respectively, are
     joining as reviewers of the "RUST" entry.

  As well as a few other minor changes and cleanups"

* tag 'rust-6.6' of https://github.com/Rust-for-Linux/linux: (42 commits)
  rust: init: update expanded macro explanation
  rust: init: add `{pin_}chain` functions to `{Pin}Init<T, E>`
  rust: init: make `PinInit<T, E>` a supertrait of `Init<T, E>`
  rust: init: implement `Zeroable` for `UnsafeCell<T>` and `Opaque<T>`
  rust: init: add support for arbitrary paths in init macros
  rust: init: add functions to create array initializers
  rust: init: add `..Zeroable::zeroed()` syntax for zeroing all missing fields
  rust: init: make initializer values inaccessible after initializing
  rust: init: wrap type checking struct initializers in a closure
  rust: init: make guards in the init macros hygienic
  rust: add derive macro for `Zeroable`
  rust: init: make `#[pin_data]` compatible with conditional compilation of fields
  rust: init: consolidate init macros
  docs: rust: clarify what 'rustup override' does
  docs: rust: update instructions for obtaining 'core' source
  docs: rust: add command line to rust-analyzer section
  scripts: generate_rust_analyzer: provide `cfg`s for `core` and `alloc`
  rust: bindgen: upgrade to 0.65.1
  rust: enable `no_mangle_with_rust_abi` Clippy lint
  rust: upgrade to Rust 1.71.1
  ...

8 files changed, 803 insertions, 517 deletions

diff --git a/rust/kernel/allocator.rs b/rust/kernel/allocator.rs
index 9363b527be66..a8f3d5be1af1 100644
--- a/rust/kernel/allocator.rs
+++ b/rust/kernel/allocator.rs
@@ -41,9 +41,9 @@ unsafe fn krealloc_aligned(ptr: *mut u8, new_layout: Layout, flags: bindings::gf
 
 unsafe impl GlobalAlloc for KernelAllocator {
     unsafe fn alloc(&self, layout: Layout) -> *mut u8 {
-        // `krealloc()` is used instead of `kmalloc()` because the latter is
-        // an inline function and cannot be bound to as a result.
-        unsafe { bindings::krealloc(ptr::null(), layout.size(), bindings::GFP_KERNEL) as *mut u8 }
+        // SAFETY: `ptr::null_mut()` is null and `layout` has a non-zero size by the function safety
+        // requirement.
+        unsafe { krealloc_aligned(ptr::null_mut(), layout, bindings::GFP_KERNEL) }
     }
 
     unsafe fn dealloc(&self, ptr: *mut u8, _layout: Layout) {
@@ -51,58 +51,38 @@ unsafe impl GlobalAlloc for KernelAllocator {
             bindings::kfree(ptr as *const core::ffi::c_void);
         }
     }
-}
-
-#[global_allocator]
-static ALLOCATOR: KernelAllocator = KernelAllocator;
-
-// `rustc` only generates these for some crate types. Even then, we would need
-// to extract the object file that has them from the archive. For the moment,
-// let's generate them ourselves instead.
-//
-// Note: Although these are *safe* functions, they are called by the compiler
-// with parameters that obey the same `GlobalAlloc` function safety
-// requirements: size and align should form a valid layout, and size is
-// greater than 0.
-//
-// Note that `#[no_mangle]` implies exported too, nowadays.
-#[no_mangle]
-fn __rust_alloc(size: usize, align: usize) -> *mut u8 {
-    // SAFETY: See assumption above.
-    let layout = unsafe { Layout::from_size_align_unchecked(size, align) };
 
-    // SAFETY: `ptr::null_mut()` is null, per assumption above the size of `layout` is greater
-    // than 0.
-    unsafe { krealloc_aligned(ptr::null_mut(), layout, bindings::GFP_KERNEL) }
-}
+    unsafe fn realloc(&self, ptr: *mut u8, layout: Layout, new_size: usize) -> *mut u8 {
+        // SAFETY:
+        // - `new_size`, when rounded up to the nearest multiple of `layout.align()`, will not
+        //   overflow `isize` by the function safety requirement.
+        // - `layout.align()` is a proper alignment (i.e. not zero and must be a power of two).
+        let layout = unsafe { Layout::from_size_align_unchecked(new_size, layout.align()) };
+
+        // SAFETY:
+        // - `ptr` is either null or a pointer allocated by this allocator by the function safety
+        //   requirement.
+        // - the size of `layout` is not zero because `new_size` is not zero by the function safety
+        //   requirement.
+        unsafe { krealloc_aligned(ptr, layout, bindings::GFP_KERNEL) }
+    }
 
-#[no_mangle]
-fn __rust_dealloc(ptr: *mut u8, _size: usize, _align: usize) {
-    unsafe { bindings::kfree(ptr as *const core::ffi::c_void) };
+    unsafe fn alloc_zeroed(&self, layout: Layout) -> *mut u8 {
+        // SAFETY: `ptr::null_mut()` is null and `layout` has a non-zero size by the function safety
+        // requirement.
+        unsafe {
+            krealloc_aligned(
+                ptr::null_mut(),
+                layout,
+                bindings::GFP_KERNEL | bindings::__GFP_ZERO,
+            )
+        }
+    }
 }
 
-#[no_mangle]
-fn __rust_realloc(ptr: *mut u8, _old_size: usize, align: usize, new_size: usize) -> *mut u8 {
-    // SAFETY: See assumption above.
-    let new_layout = unsafe { Layout::from_size_align_unchecked(new_size, align) };
-
-    // SAFETY: Per assumption above, `ptr` is allocated by `__rust_*` before, and the size of
-    // `new_layout` is greater than 0.
-    unsafe { krealloc_aligned(ptr, new_layout, bindings::GFP_KERNEL) }
-}
+#[global_allocator]
+static ALLOCATOR: KernelAllocator = KernelAllocator;
 
+// See <https://github.com/rust-lang/rust/pull/86844>.
 #[no_mangle]
-fn __rust_alloc_zeroed(size: usize, align: usize) -> *mut u8 {
-    // SAFETY: See assumption above.
-    let layout = unsafe { Layout::from_size_align_unchecked(size, align) };
-
-    // SAFETY: `ptr::null_mut()` is null, per assumption above the size of `layout` is greater
-    // than 0.
-    unsafe {
-        krealloc_aligned(
-            ptr::null_mut(),
-            layout,
-            bindings::GFP_KERNEL | bindings::__GFP_ZERO,
-        )
-    }
-}
+static __rust_no_alloc_shim_is_unstable: u8 = 0;
diff --git a/rust/kernel/init.rs b/rust/kernel/init.rs
index e05563aad2ed..4ebb6f23fc2e 100644
--- a/rust/kernel/init.rs
+++ b/rust/kernel/init.rs
@@ -212,11 +212,12 @@
 use crate::{
     error::{self, Error},
     sync::UniqueArc,
+    types::{Opaque, ScopeGuard},
 };
 use alloc::boxed::Box;
 use core::{
     alloc::AllocError,
-    cell::Cell,
+    cell::UnsafeCell,
     convert::Infallible,
     marker::PhantomData,
     mem::MaybeUninit,
@@ -518,13 +519,17 @@ macro_rules! stack_try_pin_init {
 /// - Fields that you want to initialize in-place have to use `<-` instead of `:`.
 /// - In front of the initializer you can write `&this in` to have access to a [`NonNull<Self>`]
 ///   pointer named `this` inside of the initializer.
+/// - Using struct update syntax one can place `..Zeroable::zeroed()` at the very end of the
+///   struct, this initializes every field with 0 and then runs all initializers specified in the
+///   body. This can only be done if [`Zeroable`] is implemented for the struct.
 ///
 /// For instance:
 ///
 /// ```rust
-/// # use kernel::{macros::pin_data, pin_init};
+/// # use kernel::{macros::{Zeroable, pin_data}, pin_init};
 /// # use core::{ptr::addr_of_mut, marker::PhantomPinned};
 /// #[pin_data]
+/// #[derive(Zeroable)]
 /// struct Buf {
 ///     // `ptr` points into `buf`.
 ///     ptr: *mut u8,
@@ -537,6 +542,10 @@ macro_rules! stack_try_pin_init {
 ///     ptr: unsafe { addr_of_mut!((*this.as_ptr()).buf).cast() },
 ///     pin: PhantomPinned,
 /// });
+/// pin_init!(Buf {
+///     buf: [1; 64],
+///     ..Zeroable::zeroed()
+/// });
 /// ```
 ///
 /// [`try_pin_init!`]: kernel::try_pin_init
@@ -548,11 +557,15 @@ macro_rules! pin_init {
     ($(&$this:ident in)? $t:ident $(::<$($generics:ty),* $(,)?>)? {
         $($fields:tt)*
     }) => {
-        $crate::try_pin_init!(
+        $crate::__init_internal!(
             @this($($this)?),
             @typ($t $(::<$($generics),*>)?),
             @fields($($fields)*),
             @error(::core::convert::Infallible),
+            @data(PinData, use_data),
+            @has_data(HasPinData, __pin_data),
+            @construct_closure(pin_init_from_closure),
+            @munch_fields($($fields)*),
         )
     };
 }
@@ -601,205 +614,31 @@ macro_rules! try_pin_init {
     ($(&$this:ident in)? $t:ident $(::<$($generics:ty),* $(,)?>)? {
         $($fields:tt)*
     }) => {
-        $crate::try_pin_init!(
+        $crate::__init_internal!(
             @this($($this)?),
             @typ($t $(::<$($generics),*>)? ),
             @fields($($fields)*),
             @error($crate::error::Error),
+            @data(PinData, use_data),
+            @has_data(HasPinData, __pin_data),
+            @construct_closure(pin_init_from_closure),
+            @munch_fields($($fields)*),
         )
     };
     ($(&$this:ident in)? $t:ident $(::<$($generics:ty),* $(,)?>)? {
         $($fields:tt)*
     }? $err:ty) => {
-        $crate::try_pin_init!(
+        $crate::__init_internal!(
             @this($($this)?),
             @typ($t $(::<$($generics),*>)? ),
             @fields($($fields)*),
             @error($err),
+            @data(PinData, use_data),
+            @has_data(HasPinData, __pin_data),
+            @construct_closure(pin_init_from_closure),
+            @munch_fields($($fields)*),
         )
     };
-    (
-        @this($($this:ident)?),
-        @typ($t:ident $(::<$($generics:ty),*>)?),
-        @fields($($fields:tt)*),
-        @error($err:ty),
-    ) => {{
-        // We do not want to allow arbitrary returns, so we declare this type as the `Ok` return
-        // type and shadow it later when we insert the arbitrary user code. That way there will be
-        // no possibility of returning without `unsafe`.
-        struct __InitOk;
-        // Get the pin data from the supplied type.
-        let data = unsafe {
-            use $crate::init::__internal::HasPinData;
-            $t$(::<$($generics),*>)?::__pin_data()
-        };
-        // Ensure that `data` really is of type `PinData` and help with type inference:
-        let init = $crate::init::__internal::PinData::make_closure::<_, __InitOk, $err>(
-            data,
-            move |slot| {
-                {
-                    // Shadow the structure so it cannot be used to return early.
-                    struct __InitOk;
-                    // Create the `this` so it can be referenced by the user inside of the
-                    // expressions creating the individual fields.
-                    $(let $this = unsafe { ::core::ptr::NonNull::new_unchecked(slot) };)?
-                    // Initialize every field.
-                    $crate::try_pin_init!(init_slot:
-                        @data(data),
-                        @slot(slot),
-                        @munch_fields($($fields)*,),
-                    );
-                    // We use unreachable code to ensure that all fields have been mentioned exactly
-                    // once, this struct initializer will still be type-checked and complain with a
-                    // very natural error message if a field is forgotten/mentioned more than once.
-                    #[allow(unreachable_code, clippy::diverging_sub_expression)]
-                    if false {
-                        $crate::try_pin_init!(make_initializer:
-                            @slot(slot),
-                            @type_name($t),
-                            @munch_fields($($fields)*,),
-                            @acc(),
-                        );
-                    }
-                    // Forget all guards, since initialization was a success.
-                    $crate::try_pin_init!(forget_guards:
-                        @munch_fields($($fields)*,),
-                    );
-                }
-                Ok(__InitOk)
-            }
-        );
-        let init = move |slot| -> ::core::result::Result<(), $err> {
-            init(slot).map(|__InitOk| ())
-        };
-        let init = unsafe { $crate::init::pin_init_from_closure::<_, $err>(init) };
-        init
-    }};
-    (init_slot:
-        @data($data:ident),
-        @slot($slot:ident),
-        @munch_fields($(,)?),
-    ) => {
-        // Endpoint of munching, no fields are left.
-    };
-    (init_slot:
-        @data($data:ident),
-        @slot($slot:ident),
-        // In-place initialization syntax.
-        @munch_fields($field:ident <- $val:expr, $($rest:tt)*),
-    ) => {
-        let $field = $val;
-        // Call the initializer.
-        //
-        // SAFETY: `slot` is valid, because we are inside of an initializer closure, we
-        // return when an error/panic occurs.
-        // We also use the `data` to require the correct trait (`Init` or `PinInit`) for `$field`.
-        unsafe { $data.$field(::core::ptr::addr_of_mut!((*$slot).$field), $field)? };
-        // Create the drop guard.
-        //
-        // We only give access to `&DropGuard`, so it cannot be forgotten via safe code.
-        //
-        // SAFETY: We forget the guard later when initialization has succeeded.
-        let $field = &unsafe {
-            $crate::init::__internal::DropGuard::new(::core::ptr::addr_of_mut!((*$slot).$field))
-        };
-
-        $crate::try_pin_init!(init_slot:
-            @data($data),
-            @slot($slot),
-            @munch_fields($($rest)*),
-        );
-    };
-    (init_slot:
-        @data($data:ident),
-        @slot($slot:ident),
-        // Direct value init, this is safe for every field.
-        @munch_fields($field:ident $(: $val:expr)?, $($rest:tt)*),
-    ) => {
-        $(let $field = $val;)?
-        // Initialize the field.
-        //
-        // SAFETY: The memory at `slot` is uninitialized.
-        unsafe { ::core::ptr::write(::core::ptr::addr_of_mut!((*$slot).$field), $field) };
-        // Create the drop guard:
-        //
-        // We only give access to `&DropGuard`, so it cannot be accidentally forgotten.
-        //
-        // SAFETY: We forget the guard later when initialization has succeeded.
-        let $field = &unsafe {
-            $crate::init::__internal::DropGuard::new(::core::ptr::addr_of_mut!((*$slot).$field))
-        };
-
-        $crate::try_pin_init!(init_slot:
-            @data($data),
-            @slot($slot),
-            @munch_fields($($rest)*),
-        );
-    };
-    (make_initializer:
-        @slot($slot:ident),
-        @type_name($t:ident),
-        @munch_fields($(,)?),
-        @acc($($acc:tt)*),
-    ) => {
-        // Endpoint, nothing more to munch, create the initializer.
-        // Since we are in the `if false` branch, this will never get executed. We abuse `slot` to
-        // get the correct type inference here:
-        unsafe {
-            ::core::ptr::write($slot, $t {
-                $($acc)*
-            });
-        }
-    };
-    (make_initializer:
-        @slot($slot:ident),
-        @type_name($t:ident),
-        @munch_fields($field:ident <- $val:expr, $($rest:tt)*),
-        @acc($($acc:tt)*),
-    ) => {
-        $crate::try_pin_init!(make_initializer:
-            @slot($slot),
-            @type_name($t),
-            @munch_fields($($rest)*),
-            @acc($($acc)* $field: ::core::panic!(),),
-        );
-    };
-    (make_initializer:
-        @slot($slot:ident),
-        @type_name($t:ident),
-        @munch_fields($field:ident $(: $val:expr)?, $($rest:tt)*),
-        @acc($($acc:tt)*),
-    ) => {
-        $crate::try_pin_init!(make_initializer:
-            @slot($slot),
-            @type_name($t),
-            @munch_fields($($rest)*),
-            @acc($($acc)* $field: ::core::panic!(),),
-        );
-    };
-    (forget_guards:
-        @munch_fields($(,)?),
-    ) => {
-        // Munching finished.
-    };
-    (forget_guards:
-        @munch_fields($field:ident <- $val:expr, $($rest:tt)*),
-    ) => {
-        unsafe { $crate::init::__internal::DropGuard::forget($field) };
-
-        $crate::try_pin_init!(forget_guards:
-            @munch_fields($($rest)*),
-        );
-    };
-    (forget_guards:
-        @munch_fields($field:ident $(: $val:expr)?, $($rest:tt)*),
-    ) => {
-        unsafe { $crate::init::__internal::DropGuard::forget($field) };
-
-        $crate::try_pin_init!(forget_guards:
-            @munch_fields($($rest)*),
-        );
-    };
 }
 
 /// Construct an in-place initializer for `struct`s.
@@ -824,11 +663,15 @@ macro_rules! init {
     ($(&$this:ident in)? $t:ident $(::<$($generics:ty),* $(,)?>)? {
         $($fields:tt)*
     }) => {
-        $crate::try_init!(
+        $crate::__init_internal!(
             @this($($this)?),
             @typ($t $(::<$($generics),*>)?),
             @fields($($fields)*),
             @error(::core::convert::Infallible),
+            @data(InitData, /*no use_data*/),
+            @has_data(HasInitData, __init_data),
+            @construct_closure(init_from_closure),
+            @munch_fields($($fields)*),
         )
     }
 }
@@ -871,199 +714,31 @@ macro_rules! try_init {
     ($(&$this:ident in)? $t:ident $(::<$($generics:ty),* $(,)?>)? {
         $($fields:tt)*
     }) => {
-        $crate::try_init!(
+        $crate::__init_internal!(
             @this($($this)?),
             @typ($t $(::<$($generics),*>)?),
             @fields($($fields)*),
             @error($crate::error::Error),
+            @data(InitData, /*no use_data*/),
+            @has_data(HasInitData, __init_data),
+            @construct_closure(init_from_closure),
+            @munch_fields($($fields)*),
         )
     };
     ($(&$this:ident in)? $t:ident $(::<$($generics:ty),* $(,)?>)? {
         $($fields:tt)*
     }? $err:ty) => {
-        $crate::try_init!(
+        $crate::__init_internal!(
             @this($($this)?),
             @typ($t $(::<$($generics),*>)?),
             @fields($($fields)*),
             @error($err),
+            @data(InitData, /*no use_data*/),
+            @has_data(HasInitData, __init_data),
+            @construct_closure(init_from_closure),
+            @munch_fields($($fields)*),
         )
     };
-    (
-        @this($($this:ident)?),
-        @typ($t:ident $(::<$($generics:ty),*>)?),
-        @fields($($fields:tt)*),
-        @error($err:ty),
-    ) => {{
-        // We do not want to allow arbitrary returns, so we declare this type as the `Ok` return
-        // type and shadow it later when we insert the arbitrary user code. That way there will be
-        // no possibility of returning without `unsafe`.
-        struct __InitOk;
-        // Get the init data from the supplied type.
-        let data = unsafe {
-            use $crate::init::__internal::HasInitData;
-            $t$(::<$($generics),*>)?::__init_data()
-        };
-        // Ensure that `data` really is of type `InitData` and help with type inference:
-        let init = $crate::init::__internal::InitData::make_closure::<_, __InitOk, $err>(
-            data,
-            move |slot| {
-                {
-                    // Shadow the structure so it cannot be used to return early.
-                    struct __InitOk;
-                    // Create the `this` so it can be referenced by the user inside of the
-                    // expressions creating the individual fields.
-                    $(let $this = unsafe { ::core::ptr::NonNull::new_unchecked(slot) };)?
-                    // Initialize every field.
-                    $crate::try_init!(init_slot:
-                        @slot(slot),
-                        @munch_fields($($fields)*,),
-                    );
-                    // We use unreachable code to ensure that all fields have been mentioned exactly
-                    // once, this struct initializer will still be type-checked and complain with a
-                    // very natural error message if a field is forgotten/mentioned more than once.
-                    #[allow(unreachable_code, clippy::diverging_sub_expression)]
-                    if false {
-                        $crate::try_init!(make_initializer:
-                            @slot(slot),
-                            @type_name($t),
-                            @munch_fields($($fields)*,),
-                            @acc(),
-                        );
-                    }
-                    // Forget all guards, since initialization was a success.
-                    $crate::try_init!(forget_guards:
-                        @munch_fields($($fields)*,),
-                    );
-                }
-                Ok(__InitOk)
-            }
-        );
-        let init = move |slot| -> ::core::result::Result<(), $err> {
-            init(slot).map(|__InitOk| ())
-        };
-        let init = unsafe { $crate::init::init_from_closure::<_, $err>(init) };
-        init
-    }};
-    (init_slot:
-        @slot($slot:ident),
-        @munch_fields( $(,)?),
-    ) => {
-        // Endpoint of munching, no fields are left.
-    };
-    (init_slot:
-        @slot($slot:ident),
-        @munch_fields($field:ident <- $val:expr, $($rest:tt)*),
-    ) => {
-        let $field = $val;
-        // Call the initializer.
-        //
-        // SAFETY: `slot` is valid, because we are inside of an initializer closure, we
-        // return when an error/panic occurs.
-        unsafe {
-            $crate::init::Init::__init($field, ::core::ptr::addr_of_mut!((*$slot).$field))?;
-        }
-        // Create the drop guard.
-        //
-        // We only give access to `&DropGuard`, so it cannot be accidentally forgotten.
-        //
-        // SAFETY: We forget the guard later when initialization has succeeded.
-        let $field = &unsafe {
-            $crate::init::__internal::DropGuard::new(::core::ptr::addr_of_mut!((*$slot).$field))
-        };
-
-        $crate::try_init!(init_slot:
-            @slot($slot),
-            @munch_fields($($rest)*),
-        );
-    };
-    (init_slot:
-        @slot($slot:ident),
-        // Direct value init.
-        @munch_fields($field:ident $(: $val:expr)?, $($rest:tt)*),
-    ) => {
-        $(let $field = $val;)?
-        // Call the initializer.
-        //
-        // SAFETY: The memory at `slot` is uninitialized.
-        unsafe { ::core::ptr::write(::core::ptr::addr_of_mut!((*$slot).$field), $field) };
-        // Create the drop guard.
-        //
-        // We only give access to `&DropGuard`, so it cannot be accidentally forgotten.
-        //
-        // SAFETY: We forget the guard later when initialization has succeeded.
-        let $field = &unsafe {
-            $crate::init::__internal::DropGuard::new(::core::ptr::addr_of_mut!((*$slot).$field))
-        };
-
-        $crate::try_init!(init_slot:
-            @slot($slot),
-            @munch_fields($($rest)*),
-        );
-    };
-    (make_initializer:
-        @slot($slot:ident),
-        @type_name($t:ident),
-        @munch_fields( $(,)?),
-        @acc($($acc:tt)*),
-    ) => {
-        // Endpoint, nothing more to munch, create the initializer.
-        // Since we are in the `if false` branch, this will never get executed. We abuse `slot` to
-        // get the correct type inference here:
-        unsafe {
-            ::core::ptr::write($slot, $t {
-                $($acc)*
-            });
-        }
-    };
-    (make_initializer:
-        @slot($slot:ident),
-        @type_name($t:ident),
-        @munch_fields($field:ident <- $val:expr, $($rest:tt)*),
-        @acc($($acc:tt)*),
-    ) => {
-        $crate::try_init!(make_initializer:
-            @slot($slot),
-            @type_name($t),
-            @munch_fields($($rest)*),
-            @acc($($acc)*$field: ::core::panic!(),),
-        );
-    };
-    (make_initializer:
-        @slot($slot:ident),
-        @type_name($t:ident),
-        @munch_fields($field:ident $(: $val:expr)?, $($rest:tt)*),
-        @acc($($acc:tt)*),
-    ) => {
-        $crate::try_init!(make_initializer:
-            @slot($slot),
-            @type_name($t),
-            @munch_fields($($rest)*),
-            @acc($($acc)*$field: ::core::panic!(),),
-        );
-    };
-    (forget_guards:
-        @munch_fields($(,)?),
-    ) => {
-        // Munching finished.
-    };
-    (forget_guards:
-        @munch_fields($field:ident <- $val:expr, $($rest:tt)*),
-    ) => {
-        unsafe { $crate::init::__internal::DropGuard::forget($field) };
-
-        $crate::try_init!(forget_guards:
-            @munch_fields($($rest)*),
-        );
-    };
-    (forget_guards:
-        @munch_fields($field:ident $(: $val:expr)?, $($rest:tt)*),
-    ) => {
-        unsafe { $crate::init::__internal::DropGuard::forget($field) };
-
-        $crate::try_init!(forget_guards:
-            @munch_fields($($rest)*),
-        );
-    };
 }
 
 /// A pin-initializer for the type `T`.
@@ -1100,6 +775,79 @@ pub unsafe trait PinInit<T: ?Sized, E = Infallible>: Sized {
     ///   deallocate.
     /// - `slot` will not move until it is dropped, i.e. it will be pinned.
     unsafe fn __pinned_init(self, slot: *mut T) -> Result<(), E>;
+
+    /// First initializes the value using `self` then calls the function `f` with the initialized
+    /// value.
+    ///
+    /// If `f` returns an error the value is dropped and the initializer will forward the error.
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # #![allow(clippy::disallowed_names)]
+    /// use kernel::{types::Opaque, init::pin_init_from_closure};
+    /// #[repr(C)]
+    /// struct RawFoo([u8; 16]);
+    /// extern {
+    ///     fn init_foo(_: *mut RawFoo);
+    /// }
+    ///
+    /// #[pin_data]
+    /// struct Foo {
+    ///     #[pin]
+    ///     raw: Opaque<RawFoo>,
+    /// }
+    ///
+    /// impl Foo {
+    ///     fn setup(self: Pin<&mut Self>) {
+    ///         pr_info!("Setting up foo");
+    ///     }
+    /// }
+    ///
+    /// let foo = pin_init!(Foo {
+    ///     raw <- unsafe {
+    ///         Opaque::ffi_init(|s| {
+    ///             init_foo(s);
+    ///         })
+    ///     },
+    /// }).pin_chain(|foo| {
+    ///     foo.setup();
+    ///     Ok(())
+    /// });
+    /// ```
+    fn pin_chain<F>(self, f: F) -> ChainPinInit<Self, F, T, E>
+    where
+        F: FnOnce(Pin<&mut T>) -> Result<(), E>,
+    {
+        ChainPinInit(self, f, PhantomData)
+    }
+}
+
+/// An initializer returned by [`PinInit::pin_chain`].
+pub struct ChainPinInit<I, F, T: ?Sized, E>(I, F, __internal::Invariant<(E, Box<T>)>);
+
+// SAFETY: The `__pinned_init` function is implemented such that it
+// - returns `Ok(())` on successful initialization,
+// - returns `Err(err)` on error and in this case `slot` will be dropped.
+// - considers `slot` pinned.
+unsafe impl<T: ?Sized, E, I, F> PinInit<T, E> for ChainPinInit<I, F, T, E>
+where
+    I: PinInit<T, E>,
+    F: FnOnce(Pin<&mut T>) -> Result<(), E>,
+{
+    unsafe fn __pinned_init(self, slot: *mut T) -> Result<(), E> {
+        // SAFETY: All requirements fulfilled since this function is `__pinned_init`.
+        unsafe { self.0.__pinned_init(slot)? };
+        // SAFETY: The above call initialized `slot` and we still have unique access.
+        let val = unsafe { &mut *slot };
+        // SAFETY: `slot` is considered pinned.
+        let val = unsafe { Pin::new_unchecked(val) };
+        (self.1)(val).map_err(|e| {
+            // SAFETY: `slot` was initialized above.
+            unsafe { core::ptr::drop_in_place(slot) };
+            e
+        })
+    }
 }
 
 /// An initializer for `T`.
@@ -1132,7 +880,7 @@ pub unsafe trait PinInit<T: ?Sized, E = Infallible>: Sized {
 ///
 /// [`Arc<T>`]: crate::sync::Arc
 #[must_use = "An initializer must be used in order to create its value."]
-pub unsafe trait Init<T: ?Sized, E = Infallible>: Sized {
+pub unsafe trait Init<T: ?Sized, E = Infallible>: PinInit<T, E> {
     /// Initializes `slot`.
     ///
     /// # Safety
@@ -1141,16 +889,73 @@ pub unsafe trait Init<T: ?Sized, E = Infallible>: Sized {
     /// - the caller does not touch `slot` when `Err` is returned, they are only permitted to
     ///   deallocate.
     unsafe fn __init(self, slot: *mut T) -> Result<(), E>;
+
+    /// First initializes the value using `self` then calls the function `f` with the initialized
+    /// value.
+    ///
+    /// If `f` returns an error the value is dropped and the initializer will forward the error.
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # #![allow(clippy::disallowed_names)]
+    /// use kernel::{types::Opaque, init::{self, init_from_closure}};
+    /// struct Foo {
+    ///     buf: [u8; 1_000_000],
+    /// }
+    ///
+    /// impl Foo {
+    ///     fn setup(&mut self) {
+    ///         pr_info!("Setting up foo");
+    ///     }
+    /// }
+    ///
+    /// let foo = init!(Foo {
+    ///     buf <- init::zeroed()
+    /// }).chain(|foo| {
+    ///     foo.setup();
+    ///     Ok(())
+    /// });
+    /// ```
+    fn chain<F>(self, f: F) -> ChainInit<Self, F, T, E>
+    where
+        F: FnOnce(&mut T) -> Result<(), E>,
+    {
+        ChainInit(self, f, PhantomData)
+    }
 }
 
-// SAFETY: Every in-place initializer can also be used as a pin-initializer.
-unsafe impl<T: ?Sized, E, I> PinInit<T, E> for I
+/// An initializer returned by [`Init::chain`].
+pub struct ChainInit<I, F, T: ?Sized, E>(I, F, __internal::Invariant<(E, Box<T>)>);
+
+// SAFETY: The `__init` function is implemented such that it
+// - returns `Ok(())` on successful initialization,
+// - returns `Err(err)` on error and in this case `slot` will be dropped.
+unsafe impl<T: ?Sized, E, I, F> Init<T, E> for ChainInit<I, F, T, E>
 where
     I: Init<T, E>,
+    F: FnOnce(&mut T) -> Result<(), E>,
+{
+    unsafe fn __init(self, slot: *mut T) -> Result<(), E> {
+        // SAFETY: All requirements fulfilled since this function is `__init`.
+        unsafe { self.0.__pinned_init(slot)? };
+        // SAFETY: The above call initialized `slot` and we still have unique access.
+        (self.1)(unsafe { &mut *slot }).map_err(|e| {
+            // SAFETY: `slot` was initialized above.
+            unsafe { core::ptr::drop_in_place(slot) };
+            e
+        })
+    }
+}
+
+// SAFETY: `__pinned_init` behaves exactly the same as `__init`.
+unsafe impl<T: ?Sized, E, I, F> PinInit<T, E> for ChainInit<I, F, T, E>
+where
+    I: Init<T, E>,
+    F: FnOnce(&mut T) -> Result<(), E>,
 {
     unsafe fn __pinned_init(self, slot: *mut T) -> Result<(), E> {
-        // SAFETY: `__init` meets the same requirements as `__pinned_init`, except that it does not
-        // require `slot` to not move after init.
+        // SAFETY: `__init` has less strict requirements compared to `__pinned_init`.
         unsafe { self.__init(slot) }
     }
 }
@@ -1202,6 +1007,93 @@ pub fn uninit<T, E>() -> impl Init<MaybeUninit<T>, E> {
     unsafe { init_from_closure(|_| Ok(())) }
 }
 
+/// Initializes an array by initializing each element via the provided initializer.
+///
+/// # Examples
+///
+/// ```rust
+/// use kernel::{error::Error, init::init_array_from_fn};
+/// let array: Box<[usize; 1_000]>= Box::init::<Error>(init_array_from_fn(|i| i)).unwrap();
+/// assert_eq!(array.len(), 1_000);
+/// ```
+pub fn init_array_from_fn<I, const N: usize, T, E>(
+    mut make_init: impl FnMut(usize) -> I,
+) -> impl Init<[T; N], E>
+where
+    I: Init<T, E>,
+{
+    let init = move |slot: *mut [T; N]| {
+        let slot = slot.cast::<T>();
+        // Counts the number of initialized elements and when dropped drops that many elements from
+        // `slot`.
+        let mut init_count = ScopeGuard::new_with_data(0, |i| {
+            // We now free every element that has been initialized before:
+            // SAFETY: The loop initialized exactly the values from 0..i and since we
+            // return `Err` below, the caller will consider the memory at `slot` as
+            // uninitialized.
+            unsafe { ptr::drop_in_place(ptr::slice_from_raw_parts_mut(slot, i)) };
+        });
+        for i in 0..N {
+            let init = make_init(i);
+            // SAFETY: Since 0 <= `i` < N, it is still in bounds of `[T; N]`.
+            let ptr = unsafe { slot.add(i) };
+            // SAFETY: The pointer is derived from `slot` and thus satisfies the `__init`
+            // requirements.
+            unsafe { init.__init(ptr) }?;
+            *init_count += 1;
+        }
+        init_count.dismiss();
+        Ok(())
+    };
+    // SAFETY: The initializer above initializes every element of the array. On failure it drops
+    // any initialized elements and returns `Err`.
+    unsafe { init_from_closure(init) }
+}
+
+/// Initializes an array by initializing each element via the provided initializer.
+///
+/// # Examples
+///
+/// ```rust
+/// use kernel::{sync::{Arc, Mutex}, init::pin_init_array_from_fn, new_mutex};
+/// let array: Arc<[Mutex<usize>; 1_000]>=
+///     Arc::pin_init(pin_init_array_from_fn(|i| new_mutex!(i))).unwrap();
+/// assert_eq!(array.len(), 1_000);
+/// ```
+pub fn pin_init_array_from_fn<I, const N: usize, T, E>(
+    mut make_init: impl FnMut(usize) -> I,
+) -> impl PinInit<[T; N], E>
+where
+    I: PinInit<T, E>,
+{
+    let init = move |slot: *mut [T; N]| {
+        let slot = slot.cast::<T>();
+        // Counts the number of initialized elements and when dropped drops that many elements from
+        // `slot`.
+        let mut init_count = ScopeGuard::new_with_data(0, |i| {
+            // We now free every element that has been initialized before:
+            // SAFETY: The loop initialized exactly the values from 0..i and since we
+            // return `Err` below, the caller will consider the memory at `slot` as
+            // uninitialized.
+            unsafe { ptr::drop_in_place(ptr::slice_from_raw_parts_mut(slot, i)) };
+        });
+        for i in 0..N {
+            let init = make_init(i);
+            // SAFETY: Since 0 <= `i` < N, it is still in bounds of `[T; N]`.
+            let ptr = unsafe { slot.add(i) };
+            // SAFETY: The pointer is derived from `slot` and thus satisfies the `__init`
+            // requirements.
+            unsafe { init.__pinned_init(ptr) }?;
+            *init_count += 1;
+        }
+        init_count.dismiss();
+        Ok(())
+    };
+    // SAFETY: The initializer above initializes every element of the array. On failure it drops
+    // any initialized elements and returns `Err`.
+    unsafe { pin_init_from_closure(init) }
+}
+
 // SAFETY: Every type can be initialized by-value.
 unsafe impl<T, E> Init<T, E> for T {
     unsafe fn __init(self, slot: *mut T) -> Result<(), E> {
@@ -1210,6 +1102,13 @@ unsafe impl<T, E> Init<T, E> for T {
     }
 }
 
+// SAFETY: Every type can be initialized by-value. `__pinned_init` calls `__init`.
+unsafe impl<T, E> PinInit<T, E> for T {
+    unsafe fn __pinned_init(self, slot: *mut T) -> Result<(), E> {
+        unsafe { self.__init(slot) }
+    }
+}
+
 /// Smart pointer that can initialize memory in-place.
 pub trait InPlaceInit<T>: Sized {
     /// Use the given pin-initializer to pin-initialize a `T` inside of a new smart pointer of this
@@ -1398,6 +1297,11 @@ impl_zeroable! {
 
     // SAFETY: Type is allowed to take any value, including all zeros.
     {<T>} MaybeUninit<T>,
+    // SAFETY: Type is allowed to take any value, including all zeros.
+    {<T>} Opaque<T>,
+
+    // SAFETY: `T: Zeroable` and `UnsafeCell` is `repr(transparent)`.
+    {<T: ?Sized + Zeroable>} UnsafeCell<T>,
 
     // SAFETY: All zeros is equivalent to `None` (option layout optimization guarantee).
     Option<NonZeroU8>, Option<NonZeroU16>, Option<NonZeroU32>, Option<NonZeroU64>,
diff --git a/rust/kernel/init/__internal.rs b/rust/kernel/init/__internal.rs
index 44751fb62b51..db3372619ecd 100644
--- a/rust/kernel/init/__internal.rs
+++ b/rust/kernel/init/__internal.rs
@@ -13,7 +13,7 @@ use super::*;
 ///
 /// [nomicon]: https://doc.rust-lang.org/nomicon/subtyping.html
 /// [this table]: https://doc.rust-lang.org/nomicon/phantom-data.html#table-of-phantomdata-patterns
-type Invariant<T> = PhantomData<fn(*mut T) -> *mut T>;
+pub(super) type Invariant<T> = PhantomData<fn(*mut T) -> *mut T>;
 
 /// This is the module-internal type implementing `PinInit` and `Init`. It is unsafe to create this
 /// type, since the closure needs to fulfill the same safety requirement as the
@@ -32,6 +32,18 @@ where
     }
 }
 
+// SAFETY: While constructing the `InitClosure`, the user promised that it upholds the
+// `__pinned_init` invariants.
+unsafe impl<T: ?Sized, F, E> PinInit<T, E> for InitClosure<F, T, E>
+where
+    F: FnOnce(*mut T) -> Result<(), E>,
+{
+    #[inline]
+    unsafe fn __pinned_init(self, slot: *mut T) -> Result<(), E> {
+        (self.0)(slot)
+    }
+}
+
 /// This trait is only implemented via the `#[pin_data]` proc-macro. It is used to facilitate
 /// the pin projections within the initializers.
 ///
@@ -174,7 +186,6 @@ impl<T> StackInit<T> {
 /// Can be forgotten to prevent the drop.
 pub struct DropGuard<T: ?Sized> {
     ptr: *mut T,
-    do_drop: Cell<bool>,
 }
 
 impl<T: ?Sized> DropGuard<T> {
@@ -190,32 +201,16 @@ impl<T: ?Sized> DropGuard<T> {
     /// - will not be dropped by any other means.
     #[inline]
     pub unsafe fn new(ptr: *mut T) -> Self {
-        Self {
-            ptr,
-            do_drop: Cell::new(true),
-        }
-    }
-
-    /// Prevents this guard from dropping the supplied pointer.
-    ///
-    /// # Safety
-    ///
-    /// This function is unsafe in order to prevent safe code from forgetting this guard. It should
-    /// only be called by the macros in this module.
-    #[inline]
-    pub unsafe fn forget(&self) {
-        self.do_drop.set(false);
+        Self { ptr }
     }
 }
 
 impl<T: ?Sized> Drop for DropGuard<T> {
     #[inline]
     fn drop(&mut self) {
-        if self.do_drop.get() {
-            // SAFETY: A `DropGuard` can only be constructed using the unsafe `new` function
-            // ensuring that this operation is safe.
-            unsafe { ptr::drop_in_place(self.ptr) }
-        }
+        // SAFETY: A `DropGuard` can only be constructed using the unsafe `new` function
+        // ensuring that this operation is safe.
+        unsafe { ptr::drop_in_place(self.ptr) }
     }
 }
 
diff --git a/rust/kernel/init/macros.rs b/rust/kernel/init/macros.rs
index 00aa4e956c0a..cb6e61b6c50b 100644
--- a/rust/kernel/init/macros.rs
+++ b/rust/kernel/init/macros.rs
@@ -1,10 +1,12 @@
 // SPDX-License-Identifier: Apache-2.0 OR MIT
 
 //! This module provides the macros that actually implement the proc-macros `pin_data` and
-//! `pinned_drop`.
+//! `pinned_drop`. It also contains `__init_internal` the implementation of the `{try_}{pin_}init!`
+//! macros.
 //!
 //! These macros should never be called directly, since they expect their input to be
-//! in a certain format which is internal. Use the proc-macros instead.
+//! in a certain format which is internal. If used incorrectly, these macros can lead to UB even in
+//! safe code! Use the public facing macros instead.
 //!
 //! This architecture has been chosen because the kernel does not yet have access to `syn` which
 //! would make matters a lot easier for implementing these as proc-macros.
@@ -43,7 +45,7 @@
 //! #[pinned_drop]
 //! impl PinnedDrop for Foo {
 //!     fn drop(self: Pin<&mut Self>) {
-//!         println!("{self:p} is getting dropped.");
+//!         pr_info!("{self:p} is getting dropped.");
 //!     }
 //! }
 //!
@@ -168,8 +170,10 @@
 //!         t: T,
 //!     }
 //!     #[doc(hidden)]
-//!     impl<'__pin, T>
-//!         ::core::marker::Unpin for Bar<T> where __Unpin<'__pin, T>: ::core::marker::Unpin {}
+//!     impl<'__pin, T> ::core::marker::Unpin for Bar<T>
+//!     where
+//!         __Unpin<'__pin, T>: ::core::marker::Unpin,
+//!     {}
 //!     // Now we need to ensure that `Bar` does not implement `Drop`, since that would give users
 //!     // access to `&mut self` inside of `drop` even if the struct was pinned. This could lead to
 //!     // UB with only safe code, so we disallow this by giving a trait implementation error using
@@ -186,8 +190,9 @@
 //!     // for safety, but a good sanity check, since no normal code calls `PinnedDrop::drop`.
 //!     #[allow(non_camel_case_types)]
 //!     trait UselessPinnedDropImpl_you_need_to_specify_PinnedDrop {}
-//!     impl<T: ::kernel::init::PinnedDrop>
-//!         UselessPinnedDropImpl_you_need_to_specify_PinnedDrop for T {}
+//!     impl<
+//!         T: ::kernel::init::PinnedDrop,
+//!     > UselessPinnedDropImpl_you_need_to_specify_PinnedDrop for T {}
 //!     impl<T> UselessPinnedDropImpl_you_need_to_specify_PinnedDrop for Bar<T> {}
 //! };
 //! ```
@@ -217,7 +222,7 @@
 //!             // return type and shadow it later when we insert the arbitrary user code. That way
 //!             // there will be no possibility of returning without `unsafe`.
 //!             struct __InitOk;
-//!             // Get the pin-data type from the initialized type.
+//!             // Get the data about fields from the supplied type.
 //!             // - the function is unsafe, hence the unsafe block
 //!             // - we `use` the `HasPinData` trait in the block, it is only available in that
 //!             //   scope.
@@ -225,8 +230,7 @@
 //!                 use ::kernel::init::__internal::HasPinData;
 //!                 Self::__pin_data()
 //!             };
-//!             // Use `data` to help with type inference, the closure supplied will have the type
-//!             // `FnOnce(*mut Self) -> Result<__InitOk, Infallible>`.
+//!             // Ensure that `data` really is of type `PinData` and help with type inference:
 //!             let init = ::kernel::init::__internal::PinData::make_closure::<
 //!                 _,
 //!                 __InitOk,
@@ -234,71 +238,75 @@
 //!             >(data, move |slot| {
 //!                 {
 //!                     // Shadow the structure so it cannot be used to return early. If a user
-//!                     // tries to write `return Ok(__InitOk)`, then they get a type error, since
-//!                     // that will refer to this struct instead of the one defined above.
+//!                     // tries to write `return Ok(__InitOk)`, then they get a type error,
+//!                     // since that will refer to this struct instead of the one defined
+//!                     // above.
 //!                     struct __InitOk;
 //!                     // This is the expansion of `t,`, which is syntactic sugar for `t: t,`.
-//!                     unsafe { ::core::ptr::write(::core::addr_of_mut!((*slot).t), t) };
-//!                     // Since initialization could fail later (not in this case, since the error
-//!                     // type is `Infallible`) we will need to drop this field if there is an
-//!                     // error later. This `DropGuard` will drop the field when it gets dropped
-//!                     // and has not yet been forgotten. We make a reference to it, so users
-//!                     // cannot `mem::forget` it from the initializer, since the name is the same
-//!                     // as the field (including hygiene).
-//!                     let t = &unsafe {
-//!                         ::kernel::init::__internal::DropGuard::new(
-//!                             ::core::addr_of_mut!((*slot).t),
-//!                         )
+//!                     {
+//!                         unsafe { ::core::ptr::write(::core::addr_of_mut!((*slot).t), t) };
+//!                     }
+//!                     // Since initialization could fail later (not in this case, since the
+//!                     // error type is `Infallible`) we will need to drop this field if there
+//!                     // is an error later. This `DropGuard` will drop the field when it gets
+//!                     // dropped and has not yet been forgotten.
+//!                     let t = unsafe {
+//!                         ::pinned_init::__internal::DropGuard::new(::core::addr_of_mut!((*slot).t))
 //!                     };
 //!                     // Expansion of `x: 0,`:
-//!                     // Since this can be an arbitrary expression we cannot place it inside of
-//!                     // the `unsafe` block, so we bind it here.
-//!                     let x = 0;
-//!                     unsafe { ::core::ptr::write(::core::addr_of_mut!((*slot).x), x) };
+//!                     // Since this can be an arbitrary expression we cannot place it inside
+//!                     // of the `unsafe` block, so we bind it here.
+//!                     {
+//!                         let x = 0;
+//!                         unsafe { ::core::ptr::write(::core::addr_of_mut!((*slot).x), x) };
+//!                     }
 //!                     // We again create a `DropGuard`.
-//!                     let x = &unsafe {
-//!                         ::kernel::init::__internal::DropGuard::new(
-//!                             ::core::addr_of_mut!((*slot).x),
-//!                         )
+//!                     let x = unsafe {
+//!                         ::kernel::init::__internal::DropGuard::new(::core::addr_of_mut!((*slot).x))
 //!                     };
-//!
+//!                     // Since initialization has successfully completed, we can now forget
+//!                     // the guards. This is not `mem::forget`, since we only have
+//!                     // `&DropGuard`.
+//!                     ::core::mem::forget(x);
+//!                     ::core::mem::forget(t);
 //!                     // Here we use the type checker to ensure that every field has been
 //!                     // initialized exactly once, since this is `if false` it will never get
 //!                     // executed, but still type-checked.
-//!                     // Additionally we abuse `slot` to automatically infer the correct type for
-//!                     // the struct. This is also another check that every field is accessible
-//!                     // from this scope.
+//!                     // Additionally we abuse `slot` to automatically infer the correct type
+//!                     // for the struct. This is also another check that every field is
+//!                     // accessible from this scope.
 //!                     #[allow(unreachable_code, clippy::diverging_sub_expression)]
-//!                     if false {
+//!                     let _ = || {
 //!                         unsafe {
 //!                             ::core::ptr::write(
 //!                                 slot,
 //!                                 Self {
-//!                                     // We only care about typecheck finding every field here,
-//!                                     // the expression does not matter, just conjure one using
-//!                                     // `panic!()`:
+//!                                     // We only care about typecheck finding every field
+//!                                     // here, the expression does not matter, just conjure
+//!                                     // one using `panic!()`:
 //!                                     t: ::core::panic!(),
 //!                                     x: ::core::panic!(),
 //!                                 },
 //!                             );
 //!                         };
-//!                     }
-//!                     // Since initialization has successfully completed, we can now forget the
-//!                     // guards. This is not `mem::forget`, since we only have `&DropGuard`.
-//!                     unsafe { ::kernel::init::__internal::DropGuard::forget(t) };
-//!                     unsafe { ::kernel::init::__internal::DropGuard::forget(x) };
+//!                     };
 //!                 }
 //!                 // We leave the scope above and gain access to the previously shadowed
 //!                 // `__InitOk` that we need to return.
 //!                 Ok(__InitOk)
 //!             });
 //!             // Change the return type from `__InitOk` to `()`.
-//!             let init = move |slot| -> ::core::result::Result<(), ::core::convert::Infallible> {
+//!             let init = move |
+//!                 slot,
+//!             | -> ::core::result::Result<(), ::core::convert::Infallible> {
 //!                 init(slot).map(|__InitOk| ())
 //!             };
 //!             // Construct the initializer.
 //!             let init = unsafe {
-//!                 ::kernel::init::pin_init_from_closure::<_, ::core::convert::Infallible>(init)
+//!                 ::kernel::init::pin_init_from_closure::<
+//!                     _,
+//!                     ::core::convert::Infallible,
+//!                 >(init)
 //!             };
 //!             init
 //!         }
@@ -372,7 +380,10 @@
 //!         b: Bar<u32>,
 //!     }
 //!     #[doc(hidden)]
-//!     impl<'__pin> ::core::marker::Unpin for Foo where __Unpin<'__pin>: ::core::marker::Unpin {}
+//!     impl<'__pin> ::core::marker::Unpin for Foo
+//!     where
+//!         __Unpin<'__pin>: ::core::marker::Unpin,
+//!     {}
 //!     // Since we specified `PinnedDrop` as the argument to `#[pin_data]`, we expect `Foo` to
 //!     // implement `PinnedDrop`. Thus we do not need to prevent `Drop` implementations like
 //!     // before, instead we implement `Drop` here and delegate to `PinnedDrop`.
@@ -401,7 +412,7 @@
 //! #[pinned_drop]
 //! impl PinnedDrop for Foo {
 //!     fn drop(self: Pin<&mut Self>) {
-//!         println!("{self:p} is getting dropped.");
+//!         pr_info!("{self:p} is getting dropped.");
 //!     }
 //! }
 //! ```
@@ -412,7 +423,7 @@
 //! // `unsafe`, full path and the token parameter are added, everything else stays the same.
 //! unsafe impl ::kernel::init::PinnedDrop for Foo {
 //!     fn drop(self: Pin<&mut Self>, _: ::kernel::init::__internal::OnlyCallFromDrop) {
-//!         println!("{self:p} is getting dropped.");
+//!         pr_info!("{self:p} is getting dropped.");
 //!     }
 //! }
 //! ```
@@ -447,18 +458,21 @@
 //!     >(data, move |slot| {
 //!         {
 //!             struct __InitOk;
-//!             unsafe { ::core::ptr::write(::core::addr_of_mut!((*slot).a), a) };
-//!             let a = &unsafe {
+//!             {
+//!                 unsafe { ::core::ptr::write(::core::addr_of_mut!((*slot).a), a) };
+//!             }
+//!             let a = unsafe {
 //!                 ::kernel::init::__internal::DropGuard::new(::core::addr_of_mut!((*slot).a))
 //!             };
-//!             let b = Bar::new(36);
+//!             let init = Bar::new(36);
 //!             unsafe { data.b(::core::addr_of_mut!((*slot).b), b)? };
-//!             let b = &unsafe {
+//!             let b = unsafe {
 //!                 ::kernel::init::__internal::DropGuard::new(::core::addr_of_mut!((*slot).b))
 //!             };
-//!
+//!             ::core::mem::forget(b);
+//!             ::core::mem::forget(a);
 //!             #[allow(unreachable_code, clippy::diverging_sub_expression)]
-//!             if false {
+//!             let _ = || {
 //!                 unsafe {
 //!                     ::core::ptr::write(
 //!                         slot,
@@ -468,13 +482,13 @@
 //!                         },
 //!                     );
 //!                 };
-//!             }
-//!             unsafe { ::kernel::init::__internal::DropGuard::forget(a) };
-//!             unsafe { ::kernel::init::__internal::DropGuard::forget(b) };
+//!             };
 //!         }
 //!         Ok(__InitOk)
 //!     });
-//!     let init = move |slot| -> ::core::result::Result<(), ::core::convert::Infallible> {
+//!     let init = move |
+//!         slot,
+//!     | -> ::core::result::Result<(), ::core::convert::Infallible> {
 //!         init(slot).map(|__InitOk| ())
 //!     };
 //!     let init = unsafe {
@@ -960,6 +974,7 @@ macro_rules! __pin_data {
         where $($whr)*
         {
             $(
+                $(#[$($p_attr)*])*
                 $pvis unsafe fn $p_field<E>(
                     self,
                     slot: *mut $p_type,
@@ -969,6 +984,7 @@ macro_rules! __pin_data {
                 }
             )*
             $(
+                $(#[$($attr)*])*
                 $fvis unsafe fn $field<E>(
                     self,
                     slot: *mut $type,
@@ -980,3 +996,388 @@ macro_rules! __pin_data {
         }
     };
 }
+
+/// The internal init macro. Do not call manually!
+///
+/// This is called by the `{try_}{pin_}init!` macros with various inputs.
+///
+/// This macro has multiple internal call configurations, these are always the very first ident:
+/// - nothing: this is the base case and called by the `{try_}{pin_}init!` macros.
+/// - `with_update_parsed`: when the `..Zeroable::zeroed()` syntax has been handled.
+/// - `init_slot`: recursively creates the code that initializes all fields in `slot`.
+/// - `make_initializer`: recursively create the struct initializer that guarantees that every
+///   field has been initialized exactly once.
+#[doc(hidden)]
+#[macro_export]
+macro_rules! __init_internal {
+    (
+        @this($($this:ident)?),
+        @typ($t:path),
+        @fields($($fields:tt)*),
+        @error($err:ty),
+        // Either `PinData` or `InitData`, `$use_data` should only be present in the `PinData`
+        // case.
+        @data($data:ident, $($use_data:ident)?),
+        // `HasPinData` or `HasInitData`.
+        @has_data($has_data:ident, $get_data:ident),
+        // `pin_init_from_closure` or `init_from_closure`.
+        @construct_closure($construct_closure:ident),
+        @munch_fields(),
+    ) => {
+        $crate::__init_internal!(with_update_parsed:
+            @this($($this)?),
+            @typ($t),
+            @fields($($fields)*),
+            @error($err),
+            @data($data, $($use_data)?),
+            @has_data($has_data, $get_data),
+            @construct_closure($construct_closure),
+            @zeroed(), // Nothing means default behavior.
+        )
+    };
+    (
+        @this($($this:ident)?),
+        @typ($t:path),
+        @fields($($fields:tt)*),
+        @error($err:ty),
+        // Either `PinData` or `InitData`, `$use_data` should only be present in the `PinData`
+        // case.
+        @data($data:ident, $($use_data:ident)?),
+        // `HasPinData` or `HasInitData`.
+        @has_data($has_data:ident, $get_data:ident),
+        // `pin_init_from_closure` or `init_from_closure`.
+        @construct_closure($construct_closure:ident),
+        @munch_fields(..Zeroable::zeroed()),
+    ) => {
+        $crate::__init_internal!(with_update_parsed:
+            @this($($this)?),
+            @typ($t),
+            @fields($($fields)*),
+            @error($err),
+            @data($data, $($use_data)?),
+            @has_data($has_data, $get_data),
+            @construct_closure($construct_closure),
+            @zeroed(()), // `()` means zero all fields not mentioned.
+        )
+    };
+    (
+        @this($($this:ident)?),
+        @typ($t:path),
+        @fields($($fields:tt)*),
+        @error($err:ty),
+        // Either `PinData` or `InitData`, `$use_data` should only be present in the `PinData`
+        // case.
+        @data($data:ident, $($use_data:ident)?),
+        // `HasPinData` or `HasInitData`.
+        @has_data($has_data:ident, $get_data:ident),
+        // `pin_init_from_closure` or `init_from_closure`.
+        @construct_closure($construct_closure:ident),
+        @munch_fields($ignore:tt $($rest:tt)*),
+    ) => {
+        $crate::__init_internal!(
+            @this($($this)?),
+            @typ($t),
+            @fields($($fields)*),
+            @error($err),
+            @data($data, $($use_data)?),
+            @has_data($has_data, $get_data),
+            @construct_closure($construct_closure),
+            @munch_fields($($rest)*),
+        )
+    };
+    (with_update_parsed:
+        @this($($this:ident)?),
+        @typ($t:path),
+        @fields($($fields:tt)*),
+        @error($err:ty),
+        // Either `PinData` or `InitData`, `$use_data` should only be present in the `PinData`
+        // case.
+        @data($data:ident, $($use_data:ident)?),
+        // `HasPinData` or `HasInitData`.
+        @has_data($has_data:ident, $get_data:ident),
+        // `pin_init_from_closure` or `init_from_closure`.
+        @construct_closure($construct_closure:ident),
+        @zeroed($($init_zeroed:expr)?),
+    ) => {{
+        // We do not want to allow arbitrary returns, so we declare this type as the `Ok` return
+        // type and shadow it later when we insert the arbitrary user code. That way there will be
+        // no possibility of returning without `unsafe`.
+        struct __InitOk;
+        // Get the data about fields from the supplied type.
+        let data = unsafe {
+            use $crate::init::__internal::$has_data;
+            // Here we abuse `paste!` to retokenize `$t`. Declarative macros have some internal
+            // information that is associated to already parsed fragments, so a path fragment
+            // cannot be used in this position. Doing the retokenization results in valid rust
+            // code.
+            ::kernel::macros::paste!($t::$get_data())
+        };
+        // Ensure that `data` really is of type `$data` and help with type inference:
+        let init = $crate::init::__internal::$data::make_closure::<_, __InitOk, $err>(
+            data,
+            move |slot| {
+                {
+                    // Shadow the structure so it cannot be used to return early.
+                    struct __InitOk;
+                    // If `$init_zeroed` is present we should zero the slot now and not emit an
+                    // error when fields are missing (since they will be zeroed). We also have to
+                    // check that the type actually implements `Zeroable`.
+                    $({
+                        fn assert_zeroable<T: $crate::init::Zeroable>(_: *mut T) {}
+                        // Ensure that the struct is indeed `Zeroable`.
+                        assert_zeroable(slot);
+                        // SAFETY: The type implements `Zeroable` by the check above.
+                        unsafe { ::core::ptr::write_bytes(slot, 0, 1) };
+                        $init_zeroed // This will be `()` if set.
+                    })?
+                    // Create the `this` so it can be referenced by the user inside of the
+                    // expressions creating the individual fields.
+                    $(let $this = unsafe { ::core::ptr::NonNull::new_unchecked(slot) };)?
+                    // Initialize every field.
+                    $crate::__init_internal!(init_slot($($use_data)?):
+                        @data(data),
+                        @slot(slot),
+                        @guards(),
+                        @munch_fields($($fields)*,),
+                    );
+                    // We use unreachable code to ensure that all fields have been mentioned exactly
+                    // once, this struct initializer will still be type-checked and complain with a
+                    // very natural error message if a field is forgotten/mentioned more than once.
+                    #[allow(unreachable_code, clippy::diverging_sub_expression)]
+                    let _ = || {
+                        $crate::__init_internal!(make_initializer:
+                            @slot(slot),
+                            @type_name($t),
+                            @munch_fields($($fields)*,),
+                            @acc(),
+                        );
+                    };
+                }
+                Ok(__InitOk)
+            }
+        );
+        let init = move |slot| -> ::core::result::Result<(), $err> {
+            init(slot).map(|__InitOk| ())
+        };
+        let init = unsafe { $crate::init::$construct_closure::<_, $err>(init) };
+        init
+    }};
+    (init_slot($($use_data:ident)?):
+        @data($data:ident),
+        @slot($slot:ident),
+        @guards($($guards:ident,)*),
+        @munch_fields($(..Zeroable::zeroed())? $(,)?),
+    ) => {
+        // Endpoint of munching, no fields are left. If execution reaches this point, all fields
+        // have been initialized. Therefore we can now dismiss the guards by forgetting them.
+        $(::core::mem::forget($guards);)*
+    };
+    (init_slot($use_data:ident): // `use_data` is present, so we use the `data` to init fields.
+        @data($data:ident),
+        @slot($slot:ident),
+        @guards($($guards:ident,)*),
+        // In-place initialization syntax.
+        @munch_fields($field:ident <- $val:expr, $($rest:tt)*),
+    ) => {
+        let init = $val;
+        // Call the initializer.
+        //
+        // SAFETY: `slot` is valid, because we are inside of an initializer closure, we
+        // return when an error/panic occurs.
+        // We also use the `data` to require the correct trait (`Init` or `PinInit`) for `$field`.
+        unsafe { $data.$field(::core::ptr::addr_of_mut!((*$slot).$field), init)? };
+        // Create the drop guard:
+        //
+        // We rely on macro hygiene to make it impossible for users to access this local variable.
+        // We use `paste!` to create new hygiene for `$field`.
+        ::kernel::macros::paste! {
+            // SAFETY: We forget the guard later when initialization has succeeded.
+            let [<$field>] = unsafe {
+                $crate::init::__internal::DropGuard::new(::core::ptr::addr_of_mut!((*$slot).$field))
+            };
+
+            $crate::__init_internal!(init_slot($use_data):
+                @data($data),
+                @slot($slot),
+                @guards([<$field>], $($guards,)*),
+                @munch_fields($($rest)*),
+            );
+        }
+    };
+    (init_slot(): // No `use_data`, so we use `Init::__init` directly.
+        @data($data:ident),
+        @slot($slot:ident),
+        @guards($($guards:ident,)*),
+        // In-place initialization syntax.
+        @munch_fields($field:ident <- $val:expr, $($rest:tt)*),
+    ) => {
+        let init = $val;
+        // Call the initializer.
+        //
+        // SAFETY: `slot` is valid, because we are inside of an initializer closure, we
+        // return when an error/panic occurs.
+        unsafe { $crate::init::Init::__init(init, ::core::ptr::addr_of_mut!((*$slot).$field))? };
+        // Create the drop guard:
+        //
+        // We rely on macro hygiene to make it impossible for users to access this local variable.
+        // We use `paste!` to create new hygiene for `$field`.
+        ::kernel::macros::paste! {
+            // SAFETY: We forget the guard later when initialization has succeeded.
+            let [<$field>] = unsafe {
+                $crate::init::__internal::DropGuard::new(::core::ptr::addr_of_mut!((*$slot).$field))
+            };
+
+            $crate::__init_internal!(init_slot():
+                @data($data),
+                @slot($slot),
+                @guards([<$field>], $($guards,)*),
+                @munch_fields($($rest)*),
+            );
+        }
+    };
+    (init_slot($($use_data:ident)?):
+        @data($data:ident),
+        @slot($slot:ident),
+        @guards($($guards:ident,)*),
+        // Init by-value.
+        @munch_fields($field:ident $(: $val:expr)?, $($rest:tt)*),
+    ) => {
+        {
+            $(let $field = $val;)?
+            // Initialize the field.
+            //
+            // SAFETY: The memory at `slot` is uninitialized.
+            unsafe { ::core::ptr::write(::core::ptr::addr_of_mut!((*$slot).$field), $field) };
+        }
+        // Create the drop guard:
+        //
+        // We rely on macro hygiene to make it impossible for users to access this local variable.
+        // We use `paste!` to create new hygiene for `$field`.
+        ::kernel::macros::paste! {
+            // SAFETY: We forget the guard later when initialization has succeeded.
+            let [<$field>] = unsafe {
+                $crate::init::__internal::DropGuard::new(::core::ptr::addr_of_mut!((*$slot).$field))
+            };
+
+            $crate::__init_internal!(init_slot($($use_data)?):
+                @data($data),
+                @slot($slot),
+                @guards([<$field>], $($guards,)*),
+                @munch_fields($($rest)*),
+            );
+        }
+    };
+    (make_initializer:
+        @slot($slot:ident),
+        @type_name($t:path),
+        @munch_fields(..Zeroable::zeroed() $(,)?),
+        @acc($($acc:tt)*),
+    ) => {
+        // Endpoint, nothing more to munch, create the initializer. Since the users specified
+        // `..Zeroable::zeroed()`, the slot will already have been zeroed and all field that have
+        // not been overwritten are thus zero and initialized. We still check that all fields are
+        // actually accessible by using the struct update syntax ourselves.
+        // We are inside of a closure that is never executed and thus we can abuse `slot` to
+        // get the correct type inference here:
+        #[allow(unused_assignments)]
+        unsafe {
+            let mut zeroed = ::core::mem::zeroed();
+            // We have to use type inference here to make zeroed have the correct type. This does
+            // not get executed, so it has no effect.
+            ::core::ptr::write($slot, zeroed);
+            zeroed = ::core::mem::zeroed();
+            // Here we abuse `paste!` to retokenize `$t`. Declarative macros have some internal
+            // information that is associated to already parsed fragments, so a path fragment
+            // cannot be used in this position. Doing the retokenization results in valid rust
+            // code.
+            ::kernel::macros::paste!(
+                ::core::ptr::write($slot, $t {
+                    $($acc)*
+                    ..zeroed
+                });
+            );
+        }
+    };
+    (make_initializer:
+        @slot($slot:ident),
+        @type_name($t:path),
+        @munch_fields($(,)?),
+        @acc($($acc:tt)*),
+    ) => {
+        // Endpoint, nothing more to munch, create the initializer.
+        // Since we are in the closure that is never called, this will never get executed.
+        // We abuse `slot` to get the correct type inference here:
+        unsafe {
+            // Here we abuse `paste!` to retokenize `$t`. Declarative macros have some internal
+            // information that is associated to already parsed fragments, so a path fragment
+            // cannot be used in this position. Doing the retokenization results in valid rust
+            // code.
+            ::kernel::macros::paste!(
+                ::core::ptr::write($slot, $t {
+                    $($acc)*
+                });
+            );
+        }
+    };
+    (make_initializer:
+        @slot($slot:ident),
+        @type_name($t:path),
+        @munch_fields($field:ident <- $val:expr, $($rest:tt)*),
+        @acc($($acc:tt)*),
+    ) => {
+        $crate::__init_internal!(make_initializer:
+            @slot($slot),
+            @type_name($t),
+            @munch_fields($($rest)*),
+            @acc($($acc)* $field: ::core::panic!(),),
+        );
+    };
+    (make_initializer:
+        @slot($slot:ident),
+        @type_name($t:path),
+        @munch_fields($field:ident $(: $val:expr)?, $($rest:tt)*),
+        @acc($($acc:tt)*),
+    ) => {
+        $crate::__init_internal!(make_initializer:
+            @slot($slot),
+            @type_name($t),
+            @munch_fields($($rest)*),
+            @acc($($acc)* $field: ::core::panic!(),),
+        );
+    };
+}
+
+#[doc(hidden)]
+#[macro_export]
+macro_rules! __derive_zeroable {
+    (parse_input:
+        @sig(
+            $(#[$($struct_attr:tt)*])*
+            $vis:vis struct $name:ident
+            $(where $($whr:tt)*)?
+        ),
+        @impl_generics($($impl_generics:tt)*),
+        @ty_generics($($ty_generics:tt)*),
+        @body({
+            $(
+                $(#[$($field_attr:tt)*])*
+                $field:ident : $field_ty:ty
+            ),* $(,)?
+        }),
+    ) => {
+        // SAFETY: Every field type implements `Zeroable` and padding bytes may be zero.
+        #[automatically_derived]
+        unsafe impl<$($impl_generics)*> $crate::init::Zeroable for $name<$($ty_generics)*>
+        where
+            $($($whr)*)?
+        {}
+        const _: () = {
+            fn assert_zeroable<T: ?::core::marker::Sized + $crate::init::Zeroable>() {}
+            fn ensure_zeroable<$($impl_generics)*>()
+                where $($($whr)*)?
+            {
+                $(assert_zeroable::<$field_ty>();)*
+            }
+        };
+    };
+}
diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs
index 3642cadc34b1..e8811700239a 100644
--- a/rust/kernel/lib.rs
+++ b/rust/kernel/lib.rs
@@ -95,7 +95,4 @@ fn panic(info: &core::panic::PanicInfo<'_>) -> ! {
     pr_emerg!("{}\n", info);
     // SAFETY: FFI call.
     unsafe { bindings::BUG() };
-    // Bindgen currently does not recognize `__noreturn` so `BUG` returns `()`
-    // instead of `!`. See <https://github.com/rust-lang/rust-bindgen/issues/2094>.
-    loop {}
 }
diff --git a/rust/kernel/prelude.rs b/rust/kernel/prelude.rs
index c28587d68ebc..ae21600970b3 100644
--- a/rust/kernel/prelude.rs
+++ b/rust/kernel/prelude.rs
@@ -18,7 +18,7 @@ pub use core::pin::Pin;
 pub use alloc::{boxed::Box, vec::Vec};
 
 #[doc(no_inline)]
-pub use macros::{module, pin_data, pinned_drop, vtable};
+pub use macros::{module, pin_data, pinned_drop, vtable, Zeroable};
 
 pub use super::build_assert;
 
diff --git a/rust/kernel/sync/lock.rs b/rust/kernel/sync/lock.rs
index a2216325632d..70a785f04754 100644
--- a/rust/kernel/sync/lock.rs
+++ b/rust/kernel/sync/lock.rs
@@ -72,8 +72,8 @@ pub unsafe trait Backend {
 
 /// A mutual exclusion primitive.
 ///
-/// Exposes one of the kernel locking primitives. Which one is exposed depends on the lock backend
-/// specified as the generic parameter `B`.
+/// Exposes one of the kernel locking primitives. Which one is exposed depends on the lock
+/// [`Backend`] specified as the generic parameter `B`.
 #[pin_data]
 pub struct Lock<T: ?Sized, B: Backend> {
     /// The kernel lock object.
@@ -126,7 +126,7 @@ impl<T: ?Sized, B: Backend> Lock<T, B> {
 
 /// A lock guard.
 ///
-/// Allows mutual exclusion primitives that implement the `Backend` trait to automatically unlock
+/// Allows mutual exclusion primitives that implement the [`Backend`] trait to automatically unlock
 /// when a guard goes out of scope. It also provides a safe and convenient way to access the data
 /// protected by the lock.
 #[must_use = "the lock unlocks immediately when the guard is unused"]
diff --git a/rust/kernel/types.rs b/rust/kernel/types.rs
index e33b901ab0a4..fdb778e65d79 100644
--- a/rust/kernel/types.rs
+++ b/rust/kernel/types.rs
@@ -6,7 +6,7 @@ use crate::init::{self, PinInit};
 use alloc::boxed::Box;
 use core::{
     cell::UnsafeCell,
-    marker::PhantomData,
+    marker::{PhantomData, PhantomPinned},
     mem::MaybeUninit,
     ops::{Deref, DerefMut},
     ptr::NonNull,
@@ -206,17 +206,26 @@ impl<T, F: FnOnce(T)> Drop for ScopeGuard<T, F> {
 ///
 /// This is meant to be used with FFI objects that are never interpreted by Rust code.
 #[repr(transparent)]
-pub struct Opaque<T>(MaybeUninit<UnsafeCell<T>>);
+pub struct Opaque<T> {
+    value: UnsafeCell<MaybeUninit<T>>,
+    _pin: PhantomPinned,
+}
 
 impl<T> Opaque<T> {
     /// Creates a new opaque value.
     pub const fn new(value: T) -> Self {
-        Self(MaybeUninit::new(UnsafeCell::new(value)))
+        Self {
+            value: UnsafeCell::new(MaybeUninit::new(value)),
+            _pin: PhantomPinned,
+        }
     }
 
     /// Creates an uninitialised value.
     pub const fn uninit() -> Self {
-        Self(MaybeUninit::uninit())
+        Self {
+            value: UnsafeCell::new(MaybeUninit::uninit()),
+            _pin: PhantomPinned,
+        }
     }
 
     /// Creates a pin-initializer from the given initializer closure.
@@ -240,7 +249,7 @@ impl<T> Opaque<T> {
 
     /// Returns a raw pointer to the opaque data.
     pub fn get(&self) -> *mut T {
-        UnsafeCell::raw_get(self.0.as_ptr())
+        UnsafeCell::get(&self.value).cast::<T>()
     }
 
     /// Gets the value behind `this`.
@@ -248,7 +257,7 @@ impl<T> Opaque<T> {
     /// This function is useful to get access to the value without creating intermediate
     /// references.
     pub const fn raw_get(this: *const Self) -> *mut T {
-        UnsafeCell::raw_get(this.cast::<UnsafeCell<T>>())
+        UnsafeCell::raw_get(this.cast::<UnsafeCell<MaybeUninit<T>>>()).cast::<T>()
     }
 }