9 files changed, 42 insertions, 35 deletions
diff --git a/rust/kernel/alloc/allocator_test.rs b/rust/kernel/alloc/allocator_test.rs
index e3240d16040b..c37d4c0c64e9 100644
--- a/rust/kernel/alloc/allocator_test.rs
+++ b/rust/kernel/alloc/allocator_test.rs
@@ -62,6 +62,24 @@ unsafe impl Allocator for Cmalloc {
             ));
         }
 
+        // ISO C (ISO/IEC 9899:2011) defines `aligned_alloc`:
+        //
+        // > The value of alignment shall be a valid alignment supported by the implementation
+        // [...].
+        //
+        // As an example of the "supported by the implementation" requirement, POSIX.1-2001 (IEEE
+        // 1003.1-2001) defines `posix_memalign`:
+        //
+        // > The value of alignment shall be a power of two multiple of sizeof (void *).
+        //
+        // and POSIX-based implementations of `aligned_alloc` inherit this requirement. At the time
+        // of writing, this is known to be the case on macOS (but not in glibc).
+        //
+        // Satisfy the stricter requirement to avoid spurious test failures on some platforms.
+        let min_align = core::mem::size_of::<*const crate::ffi::c_void>();
+        let layout = layout.align_to(min_align).map_err(|_| AllocError)?;
+        let layout = layout.pad_to_align();
+
         // SAFETY: Returns either NULL or a pointer to a memory allocation that satisfies or
         // exceeds the given size and alignment requirements.
         let dst = unsafe { libc_aligned_alloc(layout.align(), layout.size()) } as *mut u8;
diff --git a/rust/kernel/error.rs b/rust/kernel/error.rs
index f6ecf09cb65f..a194d83e6835 100644
--- a/rust/kernel/error.rs
+++ b/rust/kernel/error.rs
@@ -107,7 +107,7 @@ impl Error {
         } else {
             // TODO: Make it a `WARN_ONCE` once available.
             crate::pr_warn!(
-                "attempted to create `Error` with out of range `errno`: {}",
+                "attempted to create `Error` with out of range `errno`: {}\n",
                 errno
             );
             code::EINVAL
diff --git a/rust/kernel/init.rs b/rust/kernel/init.rs
index 7fd1ea8265a5..e25d047f3c82 100644
--- a/rust/kernel/init.rs
+++ b/rust/kernel/init.rs
@@ -259,7 +259,7 @@ pub mod macros;
 ///     },
 /// }));
 /// let foo: Pin<&mut Foo> = foo;
-/// pr_info!("a: {}", &*foo.a.lock());
+/// pr_info!("a: {}\n", &*foo.a.lock());
 /// ```
 ///
 /// # Syntax
@@ -319,7 +319,7 @@ macro_rules! stack_pin_init {
 ///     }, GFP_KERNEL)?,
 /// }));
 /// let foo = foo.unwrap();
-/// pr_info!("a: {}", &*foo.a.lock());
+/// pr_info!("a: {}\n", &*foo.a.lock());
 /// ```
 ///
 /// ```rust,ignore
@@ -352,7 +352,7 @@ macro_rules! stack_pin_init {
 ///         x: 64,
 ///     }, GFP_KERNEL)?,
 /// }));
-/// pr_info!("a: {}", &*foo.a.lock());
+/// pr_info!("a: {}\n", &*foo.a.lock());
 /// # Ok::<_, AllocError>(())
 /// ```
 ///
@@ -882,7 +882,7 @@ pub unsafe trait PinInit<T: ?Sized, E = Infallible>: Sized {
     ///
     /// impl Foo {
     ///     fn setup(self: Pin<&mut Self>) {
-    ///         pr_info!("Setting up foo");
+    ///         pr_info!("Setting up foo\n");
     ///     }
     /// }
     ///
@@ -986,7 +986,7 @@ pub unsafe trait Init<T: ?Sized, E = Infallible>: PinInit<T, E> {
     ///
     /// impl Foo {
     ///     fn setup(&mut self) {
-    ///         pr_info!("Setting up foo");
+    ///         pr_info!("Setting up foo\n");
     ///     }
     /// }
     ///
@@ -1336,7 +1336,7 @@ impl<T> InPlaceWrite<T> for UniqueArc<MaybeUninit<T>> {
 /// #[pinned_drop]
 /// impl PinnedDrop for Foo {
 ///     fn drop(self: Pin<&mut Self>) {
-///         pr_info!("Foo is being dropped!");
+///         pr_info!("Foo is being dropped!\n");
 ///     }
 /// }
 /// ```
@@ -1418,17 +1418,14 @@ impl_zeroable! {
     // SAFETY: `T: Zeroable` and `UnsafeCell` is `repr(transparent)`.
     {<T: ?Sized + Zeroable>} UnsafeCell<T>,
 
-    // SAFETY: All zeros is equivalent to `None` (option layout optimization guarantee).
+    // SAFETY: All zeros is equivalent to `None` (option layout optimization guarantee:
+    // https://doc.rust-lang.org/stable/std/option/index.html#representation).
     Option<NonZeroU8>, Option<NonZeroU16>, Option<NonZeroU32>, Option<NonZeroU64>,
     Option<NonZeroU128>, Option<NonZeroUsize>,
     Option<NonZeroI8>, Option<NonZeroI16>, Option<NonZeroI32>, Option<NonZeroI64>,
     Option<NonZeroI128>, Option<NonZeroIsize>,
-
-    // SAFETY: All zeros is equivalent to `None` (option layout optimization guarantee).
-    //
-    // In this case we are allowed to use `T: ?Sized`, since all zeros is the `None` variant.
-    {<T: ?Sized>} Option<NonNull<T>>,
-    {<T: ?Sized>} Option<KBox<T>>,
+    {<T>} Option<NonNull<T>>,
+    {<T>} Option<KBox<T>>,
 
     // SAFETY: `null` pointer is valid.
     //
diff --git a/rust/kernel/init/macros.rs b/rust/kernel/init/macros.rs
index 1fd146a83241..b7213962a6a5 100644
--- a/rust/kernel/init/macros.rs
+++ b/rust/kernel/init/macros.rs
@@ -45,7 +45,7 @@
 //! #[pinned_drop]
 //! impl PinnedDrop for Foo {
 //!     fn drop(self: Pin<&mut Self>) {
-//!         pr_info!("{self:p} is getting dropped.");
+//!         pr_info!("{self:p} is getting dropped.\n");
 //!     }
 //! }
 //!
@@ -412,7 +412,7 @@
 //! #[pinned_drop]
 //! impl PinnedDrop for Foo {
 //!     fn drop(self: Pin<&mut Self>) {
-//!         pr_info!("{self:p} is getting dropped.");
+//!         pr_info!("{self:p} is getting dropped.\n");
 //!     }
 //! }
 //! ```
@@ -423,7 +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) {
-//!         pr_info!("{self:p} is getting dropped.");
+//!         pr_info!("{self:p} is getting dropped.\n");
 //!     }
 //! }
 //! ```
diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs
index 398242f92a96..7697c60b2d1a 100644
--- a/rust/kernel/lib.rs
+++ b/rust/kernel/lib.rs
@@ -6,7 +6,7 @@
 //! usage by Rust code in the kernel and is shared by all of them.
 //!
 //! In other words, all the rest of the Rust code in the kernel (e.g. kernel
-//! modules written in Rust) depends on [`core`], [`alloc`] and this crate.
+//! modules written in Rust) depends on [`core`] and this crate.
 //!
 //! If you need a kernel C API that is not ported or wrapped yet here, then
 //! do so first instead of bypassing this crate.
diff --git a/rust/kernel/sync.rs b/rust/kernel/sync.rs
index 3498fb344dc9..16eab9138b2b 100644
--- a/rust/kernel/sync.rs
+++ b/rust/kernel/sync.rs
@@ -30,28 +30,20 @@ pub struct LockClassKey(Opaque<bindings::lock_class_key>);
 unsafe impl Sync for LockClassKey {}
 
 impl LockClassKey {
-    /// Creates a new lock class key.
-    pub const fn new() -> Self {
-        Self(Opaque::uninit())
-    }
-
     pub(crate) fn as_ptr(&self) -> *mut bindings::lock_class_key {
         self.0.get()
     }
 }
 
-impl Default for LockClassKey {
-    fn default() -> Self {
-        Self::new()
-    }
-}
-
 /// Defines a new static lock class and returns a pointer to it.
 #[doc(hidden)]
 #[macro_export]
 macro_rules! static_lock_class {
     () => {{
-        static CLASS: $crate::sync::LockClassKey = $crate::sync::LockClassKey::new();
+        static CLASS: $crate::sync::LockClassKey =
+            // SAFETY: lockdep expects uninitialized memory when it's handed a statically allocated
+            // lock_class_key
+            unsafe { ::core::mem::MaybeUninit::uninit().assume_init() };
         &CLASS
     }};
 }
diff --git a/rust/kernel/sync/locked_by.rs b/rust/kernel/sync/locked_by.rs
index a7b244675c2b..61f100a45b35 100644
--- a/rust/kernel/sync/locked_by.rs
+++ b/rust/kernel/sync/locked_by.rs
@@ -55,7 +55,7 @@ use core::{cell::UnsafeCell, mem::size_of, ptr};
 /// fn print_bytes_used(dir: &Directory, file: &File) {
 ///     let guard = dir.inner.lock();
 ///     let inner_file = file.inner.access(&guard);
-///     pr_info!("{} {}", guard.bytes_used, inner_file.bytes_used);
+///     pr_info!("{} {}\n", guard.bytes_used, inner_file.bytes_used);
 /// }
 ///
 /// /// Increments `bytes_used` for both the directory and file.
diff --git a/rust/kernel/task.rs b/rust/kernel/task.rs
index 07bc22a7645c..38da555a2bdb 100644
--- a/rust/kernel/task.rs
+++ b/rust/kernel/task.rs
@@ -320,7 +320,7 @@ impl Task {
 
     /// Wakes up the task.
     pub fn wake_up(&self) {
-        // SAFETY: It's always safe to call `signal_pending` on a valid task, even if the task
+        // SAFETY: It's always safe to call `wake_up_process` on a valid task, even if the task
         // running.
         unsafe { bindings::wake_up_process(self.as_ptr()) };
     }
diff --git a/rust/kernel/workqueue.rs b/rust/kernel/workqueue.rs
index 0cd100d2aefb..b7be224cdf4b 100644
--- a/rust/kernel/workqueue.rs
+++ b/rust/kernel/workqueue.rs
@@ -60,7 +60,7 @@
 //!     type Pointer = Arc<MyStruct>;
 //!
 //!     fn run(this: Arc<MyStruct>) {
-//!         pr_info!("The value is: {}", this.value);
+//!         pr_info!("The value is: {}\n", this.value);
 //!     }
 //! }
 //!
@@ -108,7 +108,7 @@
 //!     type Pointer = Arc<MyStruct>;
 //!
 //!     fn run(this: Arc<MyStruct>) {
-//!         pr_info!("The value is: {}", this.value_1);
+//!         pr_info!("The value is: {}\n", this.value_1);
 //!     }
 //! }
 //!
@@ -116,7 +116,7 @@
 //!     type Pointer = Arc<MyStruct>;
 //!
 //!     fn run(this: Arc<MyStruct>) {
-//!         pr_info!("The second value is: {}", this.value_2);
+//!         pr_info!("The second value is: {}\n", this.value_2);
 //!     }
 //! }
 //!