Merging upstream version 6.9.7.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

18 files changed, 479 insertions, 144 deletions

diff --git a/rust/kernel/allocator.rs b/rust/kernel/allocator.rs
index 4b057e8373..01ad139e19 100644
--- a/rust/kernel/allocator.rs
+++ b/rust/kernel/allocator.rs
@@ -35,7 +35,7 @@ unsafe fn krealloc_aligned(ptr: *mut u8, new_layout: Layout, flags: bindings::gf
     // - `ptr` is either null or a pointer returned from a previous `k{re}alloc()` by the
     //   function safety requirement.
     // - `size` is greater than 0 since it's either a `layout.size()` (which cannot be zero
-    //    according to the function safety requirement) or a result from `next_power_of_two()`.
+    //   according to the function safety requirement) or a result from `next_power_of_two()`.
     unsafe { bindings::krealloc(ptr as *const core::ffi::c_void, size, flags) as *mut u8 }
 }
 
diff --git a/rust/kernel/error.rs b/rust/kernel/error.rs
index 4f0c1edd63..4786d3ee1e 100644
--- a/rust/kernel/error.rs
+++ b/rust/kernel/error.rs
@@ -264,13 +264,9 @@ pub fn to_result(err: core::ffi::c_int) -> Result {
 ///     pdev: &mut PlatformDevice,
 ///     index: u32,
 /// ) -> Result<*mut core::ffi::c_void> {
-///     // SAFETY: FFI call.
-///     unsafe {
-///         from_err_ptr(bindings::devm_platform_ioremap_resource(
-///             pdev.to_ptr(),
-///             index,
-///         ))
-///     }
+///     // SAFETY: `pdev` points to a valid platform device. There are no safety requirements
+///     // on `index`.
+///     from_err_ptr(unsafe { bindings::devm_platform_ioremap_resource(pdev.to_ptr(), index) })
 /// }
 /// ```
 // TODO: Remove `dead_code` marker once an in-kernel client is available.
diff --git a/rust/kernel/init.rs b/rust/kernel/init.rs
index cf9575f156..09004b56fb 100644
--- a/rust/kernel/init.rs
+++ b/rust/kernel/init.rs
@@ -36,7 +36,7 @@
 //!
 //! ```rust
 //! # #![allow(clippy::disallowed_names)]
-//! use kernel::{prelude::*, sync::Mutex, new_mutex};
+//! use kernel::sync::{new_mutex, Mutex};
 //! # use core::pin::Pin;
 //! #[pin_data]
 //! struct Foo {
@@ -56,7 +56,7 @@
 //!
 //! ```rust
 //! # #![allow(clippy::disallowed_names)]
-//! # use kernel::{prelude::*, sync::Mutex, new_mutex};
+//! # use kernel::sync::{new_mutex, Mutex};
 //! # use core::pin::Pin;
 //! # #[pin_data]
 //! # struct Foo {
@@ -79,7 +79,7 @@
 //! above method only works for types where you can access the fields.
 //!
 //! ```rust
-//! # use kernel::{new_mutex, sync::{Arc, Mutex}};
+//! # use kernel::sync::{new_mutex, Arc, Mutex};
 //! let mtx: Result<Arc<Mutex<usize>>> = Arc::pin_init(new_mutex!(42, "example::mtx"));
 //! ```
 //!
@@ -751,10 +751,10 @@ macro_rules! try_init {
 ///
 /// # Safety
 ///
-/// When implementing this type you will need to take great care. Also there are probably very few
+/// When implementing this trait you will need to take great care. Also there are probably very few
 /// cases where a manual implementation is necessary. Use [`pin_init_from_closure`] where possible.
 ///
-/// The [`PinInit::__pinned_init`] function
+/// The [`PinInit::__pinned_init`] function:
 /// - returns `Ok(())` if it initialized every field of `slot`,
 /// - returns `Err(err)` if it encountered an error and then cleaned `slot`, this means:
 ///     - `slot` can be deallocated without UB occurring,
@@ -861,10 +861,10 @@ where
 ///
 /// # Safety
 ///
-/// When implementing this type you will need to take great care. Also there are probably very few
+/// When implementing this trait you will need to take great care. Also there are probably very few
 /// cases where a manual implementation is necessary. Use [`init_from_closure`] where possible.
 ///
-/// The [`Init::__init`] function
+/// The [`Init::__init`] function:
 /// - returns `Ok(())` if it initialized every field of `slot`,
 /// - returns `Err(err)` if it encountered an error and then cleaned `slot`, this means:
 ///     - `slot` can be deallocated without UB occurring,
@@ -1013,7 +1013,7 @@ pub fn uninit<T, E>() -> impl Init<MaybeUninit<T>, E> {
 ///
 /// ```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();
+/// 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>(
@@ -1027,7 +1027,7 @@ where
         // 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:
+            // 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.
@@ -1056,7 +1056,7 @@ where
 ///
 /// ```rust
 /// use kernel::{sync::{Arc, Mutex}, init::pin_init_array_from_fn, new_mutex};
-/// let array: Arc<[Mutex<usize>; 1_000]>=
+/// 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);
 /// ```
@@ -1071,7 +1071,7 @@ where
         // 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:
+            // 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.
diff --git a/rust/kernel/ioctl.rs b/rust/kernel/ioctl.rs
index f1d42ab699..cfa7d080b5 100644
--- a/rust/kernel/ioctl.rs
+++ b/rust/kernel/ioctl.rs
@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0
 
-//! ioctl() number definitions
+//! `ioctl()` number definitions.
 //!
 //! C header: [`include/asm-generic/ioctl.h`](srctree/include/asm-generic/ioctl.h)
 
@@ -28,13 +28,13 @@ pub const fn _IO(ty: u32, nr: u32) -> u32 {
     _IOC(uapi::_IOC_NONE, ty, nr, 0)
 }
 
-/// Build an ioctl number for an read-only ioctl.
+/// Build an ioctl number for a read-only ioctl.
 #[inline(always)]
 pub const fn _IOR<T>(ty: u32, nr: u32) -> u32 {
     _IOC(uapi::_IOC_READ, ty, nr, core::mem::size_of::<T>())
 }
 
-/// Build an ioctl number for an write-only ioctl.
+/// Build an ioctl number for a write-only ioctl.
 #[inline(always)]
 pub const fn _IOW<T>(ty: u32, nr: u32) -> u32 {
     _IOC(uapi::_IOC_WRITE, ty, nr, core::mem::size_of::<T>())
diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs
index 75efe47522..6858e2f8a3 100644
--- a/rust/kernel/lib.rs
+++ b/rust/kernel/lib.rs
@@ -14,11 +14,9 @@
 #![no_std]
 #![feature(allocator_api)]
 #![feature(coerce_unsized)]
-#![feature(const_maybe_uninit_zeroed)]
 #![feature(dispatch_from_dyn)]
 #![feature(new_uninit)]
 #![feature(offset_of)]
-#![feature(ptr_metadata)]
 #![feature(receiver_trait)]
 #![feature(unsize)]
 
@@ -49,6 +47,7 @@ pub mod std_vendor;
 pub mod str;
 pub mod sync;
 pub mod task;
+pub mod time;
 pub mod types;
 pub mod workqueue;
 
@@ -78,7 +77,7 @@ pub trait Module: Sized + Sync + Send {
 
 /// Equivalent to `THIS_MODULE` in the C API.
 ///
-/// C header: `include/linux/export.h`
+/// C header: [`include/linux/export.h`](srctree/include/linux/export.h)
 pub struct ThisModule(*mut bindings::module);
 
 // SAFETY: `THIS_MODULE` may be used from all threads within a module.
@@ -102,3 +101,35 @@ fn panic(info: &core::panic::PanicInfo<'_>) -> ! {
     // SAFETY: FFI call.
     unsafe { bindings::BUG() };
 }
+
+/// Produces a pointer to an object from a pointer to one of its fields.
+///
+/// # Safety
+///
+/// The pointer passed to this macro, and the pointer returned by this macro, must both be in
+/// bounds of the same allocation.
+///
+/// # Examples
+///
+/// ```
+/// # use kernel::container_of;
+/// struct Test {
+///     a: u64,
+///     b: u32,
+/// }
+///
+/// let test = Test { a: 10, b: 20 };
+/// let b_ptr = &test.b;
+/// // SAFETY: The pointer points at the `b` field of a `Test`, so the resulting pointer will be
+/// // in-bounds of the same allocation as `b_ptr`.
+/// let test_alias = unsafe { container_of!(b_ptr, Test, b) };
+/// assert!(core::ptr::eq(&test, test_alias));
+/// ```
+#[macro_export]
+macro_rules! container_of {
+    ($ptr:expr, $type:ty, $($f:tt)*) => {{
+        let ptr = $ptr as *const _ as *const u8;
+        let offset: usize = ::core::mem::offset_of!($type, $($f)*);
+        ptr.sub(offset) as *const $type
+    }}
+}
diff --git a/rust/kernel/net/phy.rs b/rust/kernel/net/phy.rs
index 869797745b..265d0e1c13 100644
--- a/rust/kernel/net/phy.rs
+++ b/rust/kernel/net/phy.rs
@@ -4,7 +4,7 @@
 
 //! Network PHY device.
 //!
-//! C headers: [`include/linux/phy.h`](../../../../../../../include/linux/phy.h).
+//! C headers: [`include/linux/phy.h`](srctree/include/linux/phy.h).
 
 use crate::{bindings, error::*, prelude::*, str::CStr, types::Opaque};
 
@@ -16,7 +16,7 @@ use core::marker::PhantomData;
 ///
 /// Some of PHY drivers access to the state of PHY's software state machine.
 ///
-/// [`enum phy_state`]: ../../../../../../../include/linux/phy.h
+/// [`enum phy_state`]: srctree/include/linux/phy.h
 #[derive(PartialEq, Eq)]
 pub enum DeviceState {
     /// PHY device and driver are not ready for anything.
@@ -61,7 +61,7 @@ pub enum DuplexMode {
 /// Referencing a `phy_device` using this struct asserts that you are in
 /// a context where all methods defined on this struct are safe to call.
 ///
-/// [`struct phy_device`]: ../../../../../../../include/linux/phy.h
+/// [`struct phy_device`]: srctree/include/linux/phy.h
 // During the calls to most functions in [`Driver`], the C side (`PHYLIB`) holds a lock that is
 // unique for every instance of [`Device`]. `PHYLIB` uses a different serialization technique for
 // [`Driver::resume`] and [`Driver::suspend`]: `PHYLIB` updates `phy_device`'s state with
@@ -486,7 +486,7 @@ impl<T: Driver> Adapter<T> {
 ///
 /// `self.0` is always in a valid state.
 ///
-/// [`struct phy_driver`]: ../../../../../../../include/linux/phy.h
+/// [`struct phy_driver`]: srctree/include/linux/phy.h
 #[repr(transparent)]
 pub struct DriverVTable(Opaque<bindings::phy_driver>);
 
@@ -580,12 +580,12 @@ pub trait Driver {
 
     /// Issues a PHY software reset.
     fn soft_reset(_dev: &mut Device) -> Result {
-        Err(code::ENOTSUPP)
+        kernel::build_error(VTABLE_DEFAULT_ERROR)
     }
 
     /// Probes the hardware to determine what abilities it has.
     fn get_features(_dev: &mut Device) -> Result {
-        Err(code::ENOTSUPP)
+        kernel::build_error(VTABLE_DEFAULT_ERROR)
     }
 
     /// Returns true if this is a suitable driver for the given phydev.
@@ -597,32 +597,32 @@ pub trait Driver {
     /// Configures the advertisement and resets auto-negotiation
     /// if auto-negotiation is enabled.
     fn config_aneg(_dev: &mut Device) -> Result {
-        Err(code::ENOTSUPP)
+        kernel::build_error(VTABLE_DEFAULT_ERROR)
     }
 
     /// Determines the negotiated speed and duplex.
     fn read_status(_dev: &mut Device) -> Result<u16> {
-        Err(code::ENOTSUPP)
+        kernel::build_error(VTABLE_DEFAULT_ERROR)
     }
 
     /// Suspends the hardware, saving state if needed.
     fn suspend(_dev: &mut Device) -> Result {
-        Err(code::ENOTSUPP)
+        kernel::build_error(VTABLE_DEFAULT_ERROR)
     }
 
     /// Resumes the hardware, restoring state if needed.
     fn resume(_dev: &mut Device) -> Result {
-        Err(code::ENOTSUPP)
+        kernel::build_error(VTABLE_DEFAULT_ERROR)
     }
 
     /// Overrides the default MMD read function for reading a MMD register.
     fn read_mmd(_dev: &mut Device, _devnum: u8, _regnum: u16) -> Result<u16> {
-        Err(code::ENOTSUPP)
+        kernel::build_error(VTABLE_DEFAULT_ERROR)
     }
 
     /// Overrides the default MMD write function for writing a MMD register.
     fn write_mmd(_dev: &mut Device, _devnum: u8, _regnum: u16, _val: u16) -> Result {
-        Err(code::ENOTSUPP)
+        kernel::build_error(VTABLE_DEFAULT_ERROR)
     }
 
     /// Callback for notification of link change.
diff --git a/rust/kernel/str.rs b/rust/kernel/str.rs
index 7d848b83ad..925ced8fdc 100644
--- a/rust/kernel/str.rs
+++ b/rust/kernel/str.rs
@@ -13,9 +13,102 @@ use crate::{
 };
 
 /// Byte string without UTF-8 validity guarantee.
-///
-/// `BStr` is simply an alias to `[u8]`, but has a more evident semantical meaning.
-pub type BStr = [u8];
+#[repr(transparent)]
+pub struct BStr([u8]);
+
+impl BStr {
+    /// Returns the length of this string.
+    #[inline]
+    pub const fn len(&self) -> usize {
+        self.0.len()
+    }
+
+    /// Returns `true` if the string is empty.
+    #[inline]
+    pub const fn is_empty(&self) -> bool {
+        self.len() == 0
+    }
+
+    /// Creates a [`BStr`] from a `[u8]`.
+    #[inline]
+    pub const fn from_bytes(bytes: &[u8]) -> &Self {
+        // SAFETY: `BStr` is transparent to `[u8]`.
+        unsafe { &*(bytes as *const [u8] as *const BStr) }
+    }
+}
+
+impl fmt::Display for BStr {
+    /// Formats printable ASCII characters, escaping the rest.
+    ///
+    /// ```
+    /// # use kernel::{fmt, b_str, str::{BStr, CString}};
+    /// let ascii = b_str!("Hello, BStr!");
+    /// let s = CString::try_from_fmt(fmt!("{}", ascii)).unwrap();
+    /// assert_eq!(s.as_bytes(), "Hello, BStr!".as_bytes());
+    ///
+    /// let non_ascii = b_str!("🦀");
+    /// let s = CString::try_from_fmt(fmt!("{}", non_ascii)).unwrap();
+    /// assert_eq!(s.as_bytes(), "\\xf0\\x9f\\xa6\\x80".as_bytes());
+    /// ```
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        for &b in &self.0 {
+            match b {
+                // Common escape codes.
+                b'\t' => f.write_str("\\t")?,
+                b'\n' => f.write_str("\\n")?,
+                b'\r' => f.write_str("\\r")?,
+                // Printable characters.
+                0x20..=0x7e => f.write_char(b as char)?,
+                _ => write!(f, "\\x{:02x}", b)?,
+            }
+        }
+        Ok(())
+    }
+}
+
+impl fmt::Debug for BStr {
+    /// Formats printable ASCII characters with a double quote on either end,
+    /// escaping the rest.
+    ///
+    /// ```
+    /// # use kernel::{fmt, b_str, str::{BStr, CString}};
+    /// // Embedded double quotes are escaped.
+    /// let ascii = b_str!("Hello, \"BStr\"!");
+    /// let s = CString::try_from_fmt(fmt!("{:?}", ascii)).unwrap();
+    /// assert_eq!(s.as_bytes(), "\"Hello, \\\"BStr\\\"!\"".as_bytes());
+    ///
+    /// let non_ascii = b_str!("😺");
+    /// let s = CString::try_from_fmt(fmt!("{:?}", non_ascii)).unwrap();
+    /// assert_eq!(s.as_bytes(), "\"\\xf0\\x9f\\x98\\xba\"".as_bytes());
+    /// ```
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.write_char('"')?;
+        for &b in &self.0 {
+            match b {
+                // Common escape codes.
+                b'\t' => f.write_str("\\t")?,
+                b'\n' => f.write_str("\\n")?,
+                b'\r' => f.write_str("\\r")?,
+                // String escape characters.
+                b'\"' => f.write_str("\\\"")?,
+                b'\\' => f.write_str("\\\\")?,
+                // Printable characters.
+                0x20..=0x7e => f.write_char(b as char)?,
+                _ => write!(f, "\\x{:02x}", b)?,
+            }
+        }
+        f.write_char('"')
+    }
+}
+
+impl Deref for BStr {
+    type Target = [u8];
+
+    #[inline]
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
 
 /// Creates a new [`BStr`] from a string literal.
 ///
@@ -33,7 +126,7 @@ pub type BStr = [u8];
 macro_rules! b_str {
     ($str:literal) => {{
         const S: &'static str = $str;
-        const C: &'static $crate::str::BStr = S.as_bytes();
+        const C: &'static $crate::str::BStr = $crate::str::BStr::from_bytes(S.as_bytes());
         C
     }};
 }
@@ -149,13 +242,13 @@ impl CStr {
         self.0.as_ptr() as _
     }
 
-    /// Convert the string to a byte slice without the trailing 0 byte.
+    /// Convert the string to a byte slice without the trailing `NUL` byte.
     #[inline]
     pub fn as_bytes(&self) -> &[u8] {
         &self.0[..self.len()]
     }
 
-    /// Convert the string to a byte slice containing the trailing 0 byte.
+    /// Convert the string to a byte slice containing the trailing `NUL` byte.
     #[inline]
     pub const fn as_bytes_with_nul(&self) -> &[u8] {
         &self.0
@@ -191,9 +284,9 @@ impl CStr {
     /// ```
     /// # use kernel::c_str;
     /// # use kernel::str::CStr;
+    /// let bar = c_str!("ツ");
     /// // SAFETY: String literals are guaranteed to be valid UTF-8
     /// // by the Rust compiler.
-    /// let bar = c_str!("ツ");
     /// assert_eq!(unsafe { bar.as_str_unchecked() }, "ツ");
     /// ```
     #[inline]
@@ -271,7 +364,7 @@ impl fmt::Debug for CStr {
 impl AsRef<BStr> for CStr {
     #[inline]
     fn as_ref(&self) -> &BStr {
-        self.as_bytes()
+        BStr::from_bytes(self.as_bytes())
     }
 }
 
@@ -280,7 +373,7 @@ impl Deref for CStr {
 
     #[inline]
     fn deref(&self) -> &Self::Target {
-        self.as_bytes()
+        self.as_ref()
     }
 }
 
@@ -327,7 +420,7 @@ where
 
     #[inline]
     fn index(&self, index: Idx) -> &Self::Output {
-        &self.as_bytes()[index]
+        &self.as_ref()[index]
     }
 }
 
@@ -357,6 +450,21 @@ macro_rules! c_str {
 #[cfg(test)]
 mod tests {
     use super::*;
+    use alloc::format;
+
+    const ALL_ASCII_CHARS: &'static str =
+        "\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\x09\\x0a\\x0b\\x0c\\x0d\\x0e\\x0f\
+        \\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f \
+        !\"#$%&'()*+,-./0123456789:;<=>?@\
+        ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_`abcdefghijklmnopqrstuvwxyz{|}~\\x7f\
+        \\x80\\x81\\x82\\x83\\x84\\x85\\x86\\x87\\x88\\x89\\x8a\\x8b\\x8c\\x8d\\x8e\\x8f\
+        \\x90\\x91\\x92\\x93\\x94\\x95\\x96\\x97\\x98\\x99\\x9a\\x9b\\x9c\\x9d\\x9e\\x9f\
+        \\xa0\\xa1\\xa2\\xa3\\xa4\\xa5\\xa6\\xa7\\xa8\\xa9\\xaa\\xab\\xac\\xad\\xae\\xaf\
+        \\xb0\\xb1\\xb2\\xb3\\xb4\\xb5\\xb6\\xb7\\xb8\\xb9\\xba\\xbb\\xbc\\xbd\\xbe\\xbf\
+        \\xc0\\xc1\\xc2\\xc3\\xc4\\xc5\\xc6\\xc7\\xc8\\xc9\\xca\\xcb\\xcc\\xcd\\xce\\xcf\
+        \\xd0\\xd1\\xd2\\xd3\\xd4\\xd5\\xd6\\xd7\\xd8\\xd9\\xda\\xdb\\xdc\\xdd\\xde\\xdf\
+        \\xe0\\xe1\\xe2\\xe3\\xe4\\xe5\\xe6\\xe7\\xe8\\xe9\\xea\\xeb\\xec\\xed\\xee\\xef\
+        \\xf0\\xf1\\xf2\\xf3\\xf4\\xf5\\xf6\\xf7\\xf8\\xf9\\xfa\\xfb\\xfc\\xfd\\xfe\\xff";
 
     #[test]
     fn test_cstr_to_str() {
@@ -381,6 +489,69 @@ mod tests {
         let unchecked_str = unsafe { checked_cstr.as_str_unchecked() };
         assert_eq!(unchecked_str, "🐧");
     }
+
+    #[test]
+    fn test_cstr_display() {
+        let hello_world = CStr::from_bytes_with_nul(b"hello, world!\0").unwrap();
+        assert_eq!(format!("{}", hello_world), "hello, world!");
+        let non_printables = CStr::from_bytes_with_nul(b"\x01\x09\x0a\0").unwrap();
+        assert_eq!(format!("{}", non_printables), "\\x01\\x09\\x0a");
+        let non_ascii = CStr::from_bytes_with_nul(b"d\xe9j\xe0 vu\0").unwrap();
+        assert_eq!(format!("{}", non_ascii), "d\\xe9j\\xe0 vu");
+        let good_bytes = CStr::from_bytes_with_nul(b"\xf0\x9f\xa6\x80\0").unwrap();
+        assert_eq!(format!("{}", good_bytes), "\\xf0\\x9f\\xa6\\x80");
+    }
+
+    #[test]
+    fn test_cstr_display_all_bytes() {
+        let mut bytes: [u8; 256] = [0; 256];
+        // fill `bytes` with [1..=255] + [0]
+        for i in u8::MIN..=u8::MAX {
+            bytes[i as usize] = i.wrapping_add(1);
+        }
+        let cstr = CStr::from_bytes_with_nul(&bytes).unwrap();
+        assert_eq!(format!("{}", cstr), ALL_ASCII_CHARS);
+    }
+
+    #[test]
+    fn test_cstr_debug() {
+        let hello_world = CStr::from_bytes_with_nul(b"hello, world!\0").unwrap();
+        assert_eq!(format!("{:?}", hello_world), "\"hello, world!\"");
+        let non_printables = CStr::from_bytes_with_nul(b"\x01\x09\x0a\0").unwrap();
+        assert_eq!(format!("{:?}", non_printables), "\"\\x01\\x09\\x0a\"");
+        let non_ascii = CStr::from_bytes_with_nul(b"d\xe9j\xe0 vu\0").unwrap();
+        assert_eq!(format!("{:?}", non_ascii), "\"d\\xe9j\\xe0 vu\"");
+        let good_bytes = CStr::from_bytes_with_nul(b"\xf0\x9f\xa6\x80\0").unwrap();
+        assert_eq!(format!("{:?}", good_bytes), "\"\\xf0\\x9f\\xa6\\x80\"");
+    }
+
+    #[test]
+    fn test_bstr_display() {
+        let hello_world = BStr::from_bytes(b"hello, world!");
+        assert_eq!(format!("{}", hello_world), "hello, world!");
+        let escapes = BStr::from_bytes(b"_\t_\n_\r_\\_\'_\"_");
+        assert_eq!(format!("{}", escapes), "_\\t_\\n_\\r_\\_'_\"_");
+        let others = BStr::from_bytes(b"\x01");
+        assert_eq!(format!("{}", others), "\\x01");
+        let non_ascii = BStr::from_bytes(b"d\xe9j\xe0 vu");
+        assert_eq!(format!("{}", non_ascii), "d\\xe9j\\xe0 vu");
+        let good_bytes = BStr::from_bytes(b"\xf0\x9f\xa6\x80");
+        assert_eq!(format!("{}", good_bytes), "\\xf0\\x9f\\xa6\\x80");
+    }
+
+    #[test]
+    fn test_bstr_debug() {
+        let hello_world = BStr::from_bytes(b"hello, world!");
+        assert_eq!(format!("{:?}", hello_world), "\"hello, world!\"");
+        let escapes = BStr::from_bytes(b"_\t_\n_\r_\\_\'_\"_");
+        assert_eq!(format!("{:?}", escapes), "\"_\\t_\\n_\\r_\\\\_'_\\\"_\"");
+        let others = BStr::from_bytes(b"\x01");
+        assert_eq!(format!("{:?}", others), "\"\\x01\"");
+        let non_ascii = BStr::from_bytes(b"d\xe9j\xe0 vu");
+        assert_eq!(format!("{:?}", non_ascii), "\"d\\xe9j\\xe0 vu\"");
+        let good_bytes = BStr::from_bytes(b"\xf0\x9f\xa6\x80");
+        assert_eq!(format!("{:?}", good_bytes), "\"\\xf0\\x9f\\xa6\\x80\"");
+    }
 }
 
 /// Allows formatting of [`fmt::Arguments`] into a raw buffer.
@@ -449,7 +620,7 @@ impl RawFormatter {
         self.pos as _
     }
 
-    /// Return the number of bytes written to the formatter.
+    /// Returns the number of bytes written to the formatter.
     pub(crate) fn bytes_written(&self) -> usize {
         self.pos - self.beg
     }
diff --git a/rust/kernel/sync.rs b/rust/kernel/sync.rs
index d219ee518e..c983f63fd5 100644
--- a/rust/kernel/sync.rs
+++ b/rust/kernel/sync.rs
@@ -13,8 +13,9 @@ pub mod lock;
 mod locked_by;
 
 pub use arc::{Arc, ArcBorrow, UniqueArc};
-pub use condvar::CondVar;
-pub use lock::{mutex::Mutex, spinlock::SpinLock};
+pub use condvar::{new_condvar, CondVar, CondVarTimeoutResult};
+pub use lock::mutex::{new_mutex, Mutex};
+pub use lock::spinlock::{new_spinlock, SpinLock};
 pub use locked_by::LockedBy;
 
 /// Represents a lockdep class. It's a wrapper around C's `lock_class_key`.
diff --git a/rust/kernel/sync/arc.rs b/rust/kernel/sync/arc.rs
index 77cdbcf7bd..7d4c4bf583 100644
--- a/rust/kernel/sync/arc.rs
+++ b/rust/kernel/sync/arc.rs
@@ -30,7 +30,7 @@ use core::{
     mem::{ManuallyDrop, MaybeUninit},
     ops::{Deref, DerefMut},
     pin::Pin,
-    ptr::{NonNull, Pointee},
+    ptr::NonNull,
 };
 use macros::pin_data;
 
@@ -56,7 +56,7 @@ mod std_vendor;
 ///     b: u32,
 /// }
 ///
-/// // Create a ref-counted instance of `Example`.
+/// // Create a refcounted instance of `Example`.
 /// let obj = Arc::try_new(Example { a: 10, b: 20 })?;
 ///
 /// // Get a new pointer to `obj` and increment the refcount.
@@ -239,22 +239,20 @@ impl<T: ?Sized> Arc<T> {
         // binary, so its layout is not so large that it can trigger arithmetic overflow.
         let val_offset = unsafe { refcount_layout.extend(val_layout).unwrap_unchecked().1 };
 
-        let metadata: <T as Pointee>::Metadata = core::ptr::metadata(ptr);
-        // SAFETY: The metadata of `T` and `ArcInner<T>` is the same because `ArcInner` is a struct
-        // with `T` as its last field.
+        // Pointer casts leave the metadata unchanged. This is okay because the metadata of `T` and
+        // `ArcInner<T>` is the same since `ArcInner` is a struct with `T` as its last field.
         //
         // This is documented at:
         // <https://doc.rust-lang.org/std/ptr/trait.Pointee.html>.
-        let metadata: <ArcInner<T> as Pointee>::Metadata =
-            unsafe { core::mem::transmute_copy(&metadata) };
+        let ptr = ptr as *const ArcInner<T>;
+
         // SAFETY: The pointer is in-bounds of an allocation both before and after offsetting the
         // pointer, since it originates from a previous call to `Arc::into_raw` and is still valid.
-        let ptr = unsafe { (ptr as *mut u8).sub(val_offset) as *mut () };
-        let ptr = core::ptr::from_raw_parts_mut(ptr, metadata);
+        let ptr = unsafe { ptr.byte_sub(val_offset) };
 
         // SAFETY: By the safety requirements we know that `ptr` came from `Arc::into_raw`, so the
         // reference count held then will be owned by the new `Arc` object.
-        unsafe { Self::from_inner(NonNull::new_unchecked(ptr)) }
+        unsafe { Self::from_inner(NonNull::new_unchecked(ptr.cast_mut())) }
     }
 
     /// Returns an [`ArcBorrow`] from the given [`Arc`].
@@ -365,12 +363,12 @@ impl<T: ?Sized> From<Pin<UniqueArc<T>>> for Arc<T> {
 /// A borrowed reference to an [`Arc`] instance.
 ///
 /// For cases when one doesn't ever need to increment the refcount on the allocation, it is simpler
-/// to use just `&T`, which we can trivially get from an `Arc<T>` instance.
+/// to use just `&T`, which we can trivially get from an [`Arc<T>`] instance.
 ///
 /// However, when one may need to increment the refcount, it is preferable to use an `ArcBorrow<T>`
 /// over `&Arc<T>` because the latter results in a double-indirection: a pointer (shared reference)
-/// to a pointer (`Arc<T>`) to the object (`T`). An [`ArcBorrow`] eliminates this double
-/// indirection while still allowing one to increment the refcount and getting an `Arc<T>` when/if
+/// to a pointer ([`Arc<T>`]) to the object (`T`). An [`ArcBorrow`] eliminates this double
+/// indirection while still allowing one to increment the refcount and getting an [`Arc<T>`] when/if
 /// needed.
 ///
 /// # Invariants
@@ -510,7 +508,7 @@ impl<T: ?Sized> Deref for ArcBorrow<'_, T> {
 /// # test().unwrap();
 /// ```
 ///
-/// In the following example we first allocate memory for a ref-counted `Example` but we don't
+/// In the following example we first allocate memory for a refcounted `Example` but we don't
 /// initialise it on allocation. We do initialise it later with a call to [`UniqueArc::write`],
 /// followed by a conversion to `Arc<Example>`. This is particularly useful when allocation happens
 /// in one context (e.g., sleepable) and initialisation in another (e.g., atomic):
@@ -560,7 +558,7 @@ impl<T> UniqueArc<T> {
     /// Tries to allocate a new [`UniqueArc`] instance.
     pub fn try_new(value: T) -> Result<Self, AllocError> {
         Ok(Self {
-            // INVARIANT: The newly-created object has a ref-count of 1.
+            // INVARIANT: The newly-created object has a refcount of 1.
             inner: Arc::try_new(value)?,
         })
     }
@@ -574,7 +572,7 @@ impl<T> UniqueArc<T> {
             data <- init::uninit::<T, AllocError>(),
         }? AllocError))?;
         Ok(UniqueArc {
-            // INVARIANT: The newly-created object has a ref-count of 1.
+            // INVARIANT: The newly-created object has a refcount of 1.
             // SAFETY: The pointer from the `Box` is valid.
             inner: unsafe { Arc::from_inner(Box::leak(inner).into()) },
         })
diff --git a/rust/kernel/sync/condvar.rs b/rust/kernel/sync/condvar.rs
index f65e19d5a3..0c3671caff 100644
--- a/rust/kernel/sync/condvar.rs
+++ b/rust/kernel/sync/condvar.rs
@@ -6,8 +6,18 @@
 //! variable.
 
 use super::{lock::Backend, lock::Guard, LockClassKey};
-use crate::{bindings, init::PinInit, pin_init, str::CStr, types::Opaque};
+use crate::{
+    bindings,
+    init::PinInit,
+    pin_init,
+    str::CStr,
+    task::{MAX_SCHEDULE_TIMEOUT, TASK_INTERRUPTIBLE, TASK_NORMAL, TASK_UNINTERRUPTIBLE},
+    time::Jiffies,
+    types::Opaque,
+};
+use core::ffi::{c_int, c_long};
 use core::marker::PhantomPinned;
+use core::ptr;
 use macros::pin_data;
 
 /// Creates a [`CondVar`] initialiser with the given name and a newly-created lock class.
@@ -17,6 +27,7 @@ macro_rules! new_condvar {
         $crate::sync::CondVar::new($crate::optional_name!($($name)?), $crate::static_lock_class!())
     };
 }
+pub use new_condvar;
 
 /// A conditional variable.
 ///
@@ -34,8 +45,7 @@ macro_rules! new_condvar {
 /// The following is an example of using a condvar with a mutex:
 ///
 /// ```
-/// use kernel::sync::{CondVar, Mutex};
-/// use kernel::{new_condvar, new_mutex};
+/// use kernel::sync::{new_condvar, new_mutex, CondVar, Mutex};
 ///
 /// #[pin_data]
 /// pub struct Example {
@@ -73,10 +83,12 @@ macro_rules! new_condvar {
 #[pin_data]
 pub struct CondVar {
     #[pin]
-    pub(crate) wait_list: Opaque<bindings::wait_queue_head>,
+    pub(crate) wait_queue_head: Opaque<bindings::wait_queue_head>,
 
     /// A condvar needs to be pinned because it contains a [`struct list_head`] that is
     /// self-referential, so it cannot be safely moved once it is initialised.
+    ///
+    /// [`struct list_head`]: srctree/include/linux/types.h
     #[pin]
     _pin: PhantomPinned,
 }
@@ -96,28 +108,35 @@ impl CondVar {
             _pin: PhantomPinned,
             // SAFETY: `slot` is valid while the closure is called and both `name` and `key` have
             // static lifetimes so they live indefinitely.
-            wait_list <- Opaque::ffi_init(|slot| unsafe {
+            wait_queue_head <- Opaque::ffi_init(|slot| unsafe {
                 bindings::__init_waitqueue_head(slot, name.as_char_ptr(), key.as_ptr())
             }),
         })
     }
 
-    fn wait_internal<T: ?Sized, B: Backend>(&self, wait_state: u32, guard: &mut Guard<'_, T, B>) {
+    fn wait_internal<T: ?Sized, B: Backend>(
+        &self,
+        wait_state: c_int,
+        guard: &mut Guard<'_, T, B>,
+        timeout_in_jiffies: c_long,
+    ) -> c_long {
         let wait = Opaque::<bindings::wait_queue_entry>::uninit();
 
         // SAFETY: `wait` points to valid memory.
         unsafe { bindings::init_wait(wait.get()) };
 
-        // SAFETY: Both `wait` and `wait_list` point to valid memory.
+        // SAFETY: Both `wait` and `wait_queue_head` point to valid memory.
         unsafe {
-            bindings::prepare_to_wait_exclusive(self.wait_list.get(), wait.get(), wait_state as _)
+            bindings::prepare_to_wait_exclusive(self.wait_queue_head.get(), wait.get(), wait_state)
         };
 
-        // SAFETY: No arguments, switches to another thread.
-        guard.do_unlocked(|| unsafe { bindings::schedule() });
+        // SAFETY: Switches to another thread. The timeout can be any number.
+        let ret = guard.do_unlocked(|| unsafe { bindings::schedule_timeout(timeout_in_jiffies) });
+
+        // SAFETY: Both `wait` and `wait_queue_head` point to valid memory.
+        unsafe { bindings::finish_wait(self.wait_queue_head.get(), wait.get()) };
 
-        // SAFETY: Both `wait` and `wait_list` point to valid memory.
-        unsafe { bindings::finish_wait(self.wait_list.get(), wait.get()) };
+        ret
     }
 
     /// Releases the lock and waits for a notification in uninterruptible mode.
@@ -127,7 +146,7 @@ impl CondVar {
     /// [`CondVar::notify_one`] or [`CondVar::notify_all`]. Note that it may also wake up
     /// spuriously.
     pub fn wait<T: ?Sized, B: Backend>(&self, guard: &mut Guard<'_, T, B>) {
-        self.wait_internal(bindings::TASK_UNINTERRUPTIBLE, guard);
+        self.wait_internal(TASK_UNINTERRUPTIBLE, guard, MAX_SCHEDULE_TIMEOUT);
     }
 
     /// Releases the lock and waits for a notification in interruptible mode.
@@ -138,29 +157,60 @@ impl CondVar {
     /// Returns whether there is a signal pending.
     #[must_use = "wait_interruptible returns if a signal is pending, so the caller must check the return value"]
     pub fn wait_interruptible<T: ?Sized, B: Backend>(&self, guard: &mut Guard<'_, T, B>) -> bool {
-        self.wait_internal(bindings::TASK_INTERRUPTIBLE, guard);
+        self.wait_internal(TASK_INTERRUPTIBLE, guard, MAX_SCHEDULE_TIMEOUT);
         crate::current!().signal_pending()
     }
 
-    /// Calls the kernel function to notify the appropriate number of threads with the given flags.
-    fn notify(&self, count: i32, flags: u32) {
-        // SAFETY: `wait_list` points to valid memory.
+    /// Releases the lock and waits for a notification in interruptible mode.
+    ///
+    /// Atomically releases the given lock (whose ownership is proven by the guard) and puts the
+    /// thread to sleep. It wakes up when notified by [`CondVar::notify_one`] or
+    /// [`CondVar::notify_all`], or when a timeout occurs, or when the thread receives a signal.
+    #[must_use = "wait_interruptible_timeout returns if a signal is pending, so the caller must check the return value"]
+    pub fn wait_interruptible_timeout<T: ?Sized, B: Backend>(
+        &self,
+        guard: &mut Guard<'_, T, B>,
+        jiffies: Jiffies,
+    ) -> CondVarTimeoutResult {
+        let jiffies = jiffies.try_into().unwrap_or(MAX_SCHEDULE_TIMEOUT);
+        let res = self.wait_internal(TASK_INTERRUPTIBLE, guard, jiffies);
+
+        match (res as Jiffies, crate::current!().signal_pending()) {
+            (jiffies, true) => CondVarTimeoutResult::Signal { jiffies },
+            (0, false) => CondVarTimeoutResult::Timeout,
+            (jiffies, false) => CondVarTimeoutResult::Woken { jiffies },
+        }
+    }
+
+    /// Calls the kernel function to notify the appropriate number of threads.
+    fn notify(&self, count: c_int) {
+        // SAFETY: `wait_queue_head` points to valid memory.
         unsafe {
             bindings::__wake_up(
-                self.wait_list.get(),
-                bindings::TASK_NORMAL,
+                self.wait_queue_head.get(),
+                TASK_NORMAL,
                 count,
-                flags as _,
+                ptr::null_mut(),
             )
         };
     }
 
+    /// Calls the kernel function to notify one thread synchronously.
+    ///
+    /// This method behaves like `notify_one`, except that it hints to the scheduler that the
+    /// current thread is about to go to sleep, so it should schedule the target thread on the same
+    /// CPU.
+    pub fn notify_sync(&self) {
+        // SAFETY: `wait_queue_head` points to valid memory.
+        unsafe { bindings::__wake_up_sync(self.wait_queue_head.get(), TASK_NORMAL) };
+    }
+
     /// Wakes a single waiter up, if any.
     ///
     /// This is not 'sticky' in the sense that if no thread is waiting, the notification is lost
     /// completely (as opposed to automatically waking up the next waiter).
     pub fn notify_one(&self) {
-        self.notify(1, 0);
+        self.notify(1);
     }
 
     /// Wakes all waiters up, if any.
@@ -168,6 +218,22 @@ impl CondVar {
     /// This is not 'sticky' in the sense that if no thread is waiting, the notification is lost
     /// completely (as opposed to automatically waking up the next waiter).
     pub fn notify_all(&self) {
-        self.notify(0, 0);
+        self.notify(0);
     }
 }
+
+/// The return type of `wait_timeout`.
+pub enum CondVarTimeoutResult {
+    /// The timeout was reached.
+    Timeout,
+    /// Somebody woke us up.
+    Woken {
+        /// Remaining sleep duration.
+        jiffies: Jiffies,
+    },
+    /// A signal occurred.
+    Signal {
+        /// Remaining sleep duration.
+        jiffies: Jiffies,
+    },
+}
diff --git a/rust/kernel/sync/lock.rs b/rust/kernel/sync/lock.rs
index f12a684bc9..5b5c8efe42 100644
--- a/rust/kernel/sync/lock.rs
+++ b/rust/kernel/sync/lock.rs
@@ -21,14 +21,21 @@ pub mod spinlock;
 /// # Safety
 ///
 /// - Implementers must ensure that only one thread/CPU may access the protected data once the lock
-/// is owned, that is, between calls to `lock` and `unlock`.
-/// - Implementers must also ensure that `relock` uses the same locking method as the original
-/// lock operation.
+///   is owned, that is, between calls to [`lock`] and [`unlock`].
+/// - Implementers must also ensure that [`relock`] uses the same locking method as the original
+///   lock operation.
+///
+/// [`lock`]: Backend::lock
+/// [`unlock`]: Backend::unlock
+/// [`relock`]: Backend::relock
 pub unsafe trait Backend {
     /// The state required by the lock.
     type State;
 
-    /// The state required to be kept between lock and unlock.
+    /// The state required to be kept between [`lock`] and [`unlock`].
+    ///
+    /// [`lock`]: Backend::lock
+    /// [`unlock`]: Backend::unlock
     type GuardState;
 
     /// Initialises the lock.
@@ -139,7 +146,7 @@ pub struct Guard<'a, T: ?Sized, B: Backend> {
 unsafe impl<T: Sync + ?Sized, B: Backend> Sync for Guard<'_, T, B> {}
 
 impl<T: ?Sized, B: Backend> Guard<'_, T, B> {
-    pub(crate) fn do_unlocked(&mut self, cb: impl FnOnce()) {
+    pub(crate) fn do_unlocked<U>(&mut self, cb: impl FnOnce() -> U) -> U {
         // SAFETY: The caller owns the lock, so it is safe to unlock it.
         unsafe { B::unlock(self.lock.state.get(), &self.state) };
 
@@ -147,7 +154,7 @@ impl<T: ?Sized, B: Backend> Guard<'_, T, B> {
         let _relock =
             ScopeGuard::new(|| unsafe { B::relock(self.lock.state.get(), &mut self.state) });
 
-        cb();
+        cb()
     }
 }
 
diff --git a/rust/kernel/sync/lock/mutex.rs b/rust/kernel/sync/lock/mutex.rs
index 8c524a3ec4..ef4c4634d2 100644
--- a/rust/kernel/sync/lock/mutex.rs
+++ b/rust/kernel/sync/lock/mutex.rs
@@ -17,6 +17,7 @@ macro_rules! new_mutex {
             $inner, $crate::optional_name!($($name)?), $crate::static_lock_class!())
     };
 }
+pub use new_mutex;
 
 /// A mutual exclusion primitive.
 ///
@@ -35,7 +36,7 @@ macro_rules! new_mutex {
 /// contains an inner struct (`Inner`) that is protected by a mutex.
 ///
 /// ```
-/// use kernel::{init::InPlaceInit, init::PinInit, new_mutex, pin_init, sync::Mutex};
+/// use kernel::sync::{new_mutex, Mutex};
 ///
 /// struct Inner {
 ///     a: u32,
diff --git a/rust/kernel/sync/lock/spinlock.rs b/rust/kernel/sync/lock/spinlock.rs
index 068535ce1b..0b22c63563 100644
--- a/rust/kernel/sync/lock/spinlock.rs
+++ b/rust/kernel/sync/lock/spinlock.rs
@@ -17,6 +17,7 @@ macro_rules! new_spinlock {
             $inner, $crate::optional_name!($($name)?), $crate::static_lock_class!())
     };
 }
+pub use new_spinlock;
 
 /// A spinlock.
 ///
@@ -33,7 +34,7 @@ macro_rules! new_spinlock {
 /// contains an inner struct (`Inner`) that is protected by a spinlock.
 ///
 /// ```
-/// use kernel::{init::InPlaceInit, init::PinInit, new_spinlock, pin_init, sync::SpinLock};
+/// use kernel::sync::{new_spinlock, SpinLock};
 ///
 /// struct Inner {
 ///     a: u32,
@@ -112,7 +113,7 @@ unsafe impl super::Backend for SpinLockBackend {
 
     unsafe fn unlock(ptr: *mut Self::State, _guard_state: &Self::GuardState) {
         // SAFETY: The safety requirements of this function ensure that `ptr` is valid and that the
-        // caller is the owner of the mutex.
+        // caller is the owner of the spinlock.
         unsafe { bindings::spin_unlock(ptr) }
     }
 }
diff --git a/rust/kernel/sync/locked_by.rs b/rust/kernel/sync/locked_by.rs
index b17ee5cd98..babc731bd5 100644
--- a/rust/kernel/sync/locked_by.rs
+++ b/rust/kernel/sync/locked_by.rs
@@ -9,14 +9,17 @@ use core::{cell::UnsafeCell, mem::size_of, ptr};
 /// Allows access to some data to be serialised by a lock that does not wrap it.
 ///
 /// In most cases, data protected by a lock is wrapped by the appropriate lock type, e.g.,
-/// [`super::Mutex`] or [`super::SpinLock`]. [`LockedBy`] is meant for cases when this is not
-/// possible. For example, if a container has a lock and some data in the contained elements needs
+/// [`Mutex`] or [`SpinLock`]. [`LockedBy`] is meant for cases when this is not possible.
+/// For example, if a container has a lock and some data in the contained elements needs
 /// to be protected by the same lock.
 ///
 /// [`LockedBy`] wraps the data in lieu of another locking primitive, and only allows access to it
 /// when the caller shows evidence that the 'external' lock is locked. It panics if the evidence
 /// refers to the wrong instance of the lock.
 ///
+/// [`Mutex`]: super::Mutex
+/// [`SpinLock`]: super::SpinLock
+///
 /// # Examples
 ///
 /// The following is an example for illustrative purposes: `InnerDirectory::bytes_used` is an
diff --git a/rust/kernel/task.rs b/rust/kernel/task.rs
index 9451932d5d..ca6e7e31d7 100644
--- a/rust/kernel/task.rs
+++ b/rust/kernel/task.rs
@@ -5,7 +5,23 @@
 //! C header: [`include/linux/sched.h`](srctree/include/linux/sched.h).
 
 use crate::{bindings, types::Opaque};
-use core::{marker::PhantomData, ops::Deref, ptr};
+use core::{
+    ffi::{c_int, c_long, c_uint},
+    marker::PhantomData,
+    ops::Deref,
+    ptr,
+};
+
+/// A sentinel value used for infinite timeouts.
+pub const MAX_SCHEDULE_TIMEOUT: c_long = c_long::MAX;
+
+/// Bitmask for tasks that are sleeping in an interruptible state.
+pub const TASK_INTERRUPTIBLE: c_int = bindings::TASK_INTERRUPTIBLE as c_int;
+/// Bitmask for tasks that are sleeping in an uninterruptible state.
+pub const TASK_UNINTERRUPTIBLE: c_int = bindings::TASK_UNINTERRUPTIBLE as c_int;
+/// Convenience constant for waking up tasks regardless of whether they are in interruptible or
+/// uninterruptible sleep.
+pub const TASK_NORMAL: c_uint = bindings::TASK_NORMAL as c_uint;
 
 /// Returns the currently running task.
 #[macro_export]
@@ -23,7 +39,7 @@ macro_rules! current {
 ///
 /// All instances are valid tasks created by the C portion of the kernel.
 ///
-/// Instances of this type are always ref-counted, that is, a call to `get_task_struct` ensures
+/// Instances of this type are always refcounted, that is, a call to `get_task_struct` ensures
 /// that the allocation remains valid at least until the matching call to `put_task_struct`.
 ///
 /// # Examples
@@ -116,7 +132,7 @@ impl Task {
     /// Returns the group leader of the given task.
     pub fn group_leader(&self) -> &Task {
         // SAFETY: By the type invariant, we know that `self.0` is a valid task. Valid tasks always
-        // have a valid group_leader.
+        // have a valid `group_leader`.
         let ptr = unsafe { *ptr::addr_of!((*self.0.get()).group_leader) };
 
         // SAFETY: The lifetime of the returned task reference is tied to the lifetime of `self`,
@@ -147,7 +163,7 @@ impl Task {
     }
 }
 
-// SAFETY: The type invariants guarantee that `Task` is always ref-counted.
+// SAFETY: The type invariants guarantee that `Task` is always refcounted.
 unsafe impl crate::types::AlwaysRefCounted for Task {
     fn inc_ref(&self) {
         // SAFETY: The existence of a shared reference means that the refcount is nonzero.
diff --git a/rust/kernel/time.rs b/rust/kernel/time.rs
new file mode 100644
index 0000000000..25a896eed4
--- /dev/null
+++ b/rust/kernel/time.rs
@@ -0,0 +1,20 @@
+// SPDX-License-Identifier: GPL-2.0
+
+//! Time related primitives.
+//!
+//! This module contains the kernel APIs related to time and timers that
+//! have been ported or wrapped for usage by Rust code in the kernel.
+
+/// The time unit of Linux kernel. One jiffy equals (1/HZ) second.
+pub type Jiffies = core::ffi::c_ulong;
+
+/// The millisecond time unit.
+pub type Msecs = core::ffi::c_uint;
+
+/// Converts milliseconds to jiffies.
+#[inline]
+pub fn msecs_to_jiffies(msecs: Msecs) -> Jiffies {
+    // SAFETY: The `__msecs_to_jiffies` function is always safe to call no
+    // matter what the argument is.
+    unsafe { bindings::__msecs_to_jiffies(msecs) }
+}
diff --git a/rust/kernel/types.rs b/rust/kernel/types.rs
index fdb778e65d..aa77bad9bc 100644
--- a/rust/kernel/types.rs
+++ b/rust/kernel/types.rs
@@ -46,6 +46,25 @@ pub trait ForeignOwnable: Sized {
     /// Additionally, all instances (if any) of values returned by [`ForeignOwnable::borrow`] for
     /// this object must have been dropped.
     unsafe fn from_foreign(ptr: *const core::ffi::c_void) -> Self;
+
+    /// Tries to convert a foreign-owned object back to a Rust-owned one.
+    ///
+    /// A convenience wrapper over [`ForeignOwnable::from_foreign`] that returns [`None`] if `ptr`
+    /// is null.
+    ///
+    /// # Safety
+    ///
+    /// `ptr` must either be null or satisfy the safety requirements for
+    /// [`ForeignOwnable::from_foreign`].
+    unsafe fn try_from_foreign(ptr: *const core::ffi::c_void) -> Option<Self> {
+        if ptr.is_null() {
+            None
+        } else {
+            // SAFETY: Since `ptr` is not null here, then `ptr` satisfies the safety requirements
+            // of `from_foreign` given the safety requirements of this function.
+            unsafe { Some(Self::from_foreign(ptr)) }
+        }
+    }
 }
 
 impl<T: 'static> ForeignOwnable for Box<T> {
@@ -90,6 +109,7 @@ impl ForeignOwnable for () {
 ///
 /// In the example below, we have multiple exit paths and we want to log regardless of which one is
 /// taken:
+///
 /// ```
 /// # use kernel::types::ScopeGuard;
 /// fn example1(arg: bool) {
@@ -108,6 +128,7 @@ impl ForeignOwnable for () {
 ///
 /// In the example below, we want to log the same message on all early exits but a different one on
 /// the main exit path:
+///
 /// ```
 /// # use kernel::types::ScopeGuard;
 /// fn example2(arg: bool) {
@@ -129,6 +150,7 @@ impl ForeignOwnable for () {
 ///
 /// In the example below, we need a mutable object (the vector) to be accessible within the log
 /// function, so we wrap it in the [`ScopeGuard`]:
+///
 /// ```
 /// # use kernel::types::ScopeGuard;
 /// fn example3(arg: bool) -> Result {
diff --git a/rust/kernel/workqueue.rs b/rust/kernel/workqueue.rs
index 4983978773..480cb292e7 100644
--- a/rust/kernel/workqueue.rs
+++ b/rust/kernel/workqueue.rs
@@ -12,19 +12,19 @@
 //!
 //! # The raw API
 //!
-//! The raw API consists of the `RawWorkItem` trait, where the work item needs to provide an
+//! The raw API consists of the [`RawWorkItem`] trait, where the work item needs to provide an
 //! arbitrary function that knows how to enqueue the work item. It should usually not be used
 //! directly, but if you want to, you can use it without using the pieces from the safe API.
 //!
 //! # The safe API
 //!
-//! The safe API is used via the `Work` struct and `WorkItem` traits. Furthermore, it also includes
-//! a trait called `WorkItemPointer`, which is usually not used directly by the user.
+//! The safe API is used via the [`Work`] struct and [`WorkItem`] traits. Furthermore, it also
+//! includes a trait called [`WorkItemPointer`], which is usually not used directly by the user.
 //!
-//!  * The `Work` struct is the Rust wrapper for the C `work_struct` type.
-//!  * The `WorkItem` trait is implemented for structs that can be enqueued to a workqueue.
-//!  * The `WorkItemPointer` trait is implemented for the pointer type that points at a something
-//!    that implements `WorkItem`.
+//!  * The [`Work`] struct is the Rust wrapper for the C `work_struct` type.
+//!  * The [`WorkItem`] trait is implemented for structs that can be enqueued to a workqueue.
+//!  * The [`WorkItemPointer`] trait is implemented for the pointer type that points at a something
+//!    that implements [`WorkItem`].
 //!
 //! ## Example
 //!
@@ -35,8 +35,7 @@
 //! ```
 //! use kernel::prelude::*;
 //! use kernel::sync::Arc;
-//! use kernel::workqueue::{self, Work, WorkItem};
-//! use kernel::{impl_has_work, new_work};
+//! use kernel::workqueue::{self, impl_has_work, new_work, Work, WorkItem};
 //!
 //! #[pin_data]
 //! struct MyStruct {
@@ -78,8 +77,7 @@
 //! ```
 //! use kernel::prelude::*;
 //! use kernel::sync::Arc;
-//! use kernel::workqueue::{self, Work, WorkItem};
-//! use kernel::{impl_has_work, new_work};
+//! use kernel::workqueue::{self, impl_has_work, new_work, Work, WorkItem};
 //!
 //! #[pin_data]
 //! struct MyStruct {
@@ -147,6 +145,7 @@ macro_rules! new_work {
         $crate::workqueue::Work::new($crate::optional_name!($($name)?), $crate::static_lock_class!())
     };
 }
+pub use new_work;
 
 /// A kernel work queue.
 ///
@@ -168,7 +167,7 @@ impl Queue {
     /// # Safety
     ///
     /// The caller must ensure that the provided raw pointer is not dangling, that it points at a
-    /// valid workqueue, and that it remains valid until the end of 'a.
+    /// valid workqueue, and that it remains valid until the end of `'a`.
     pub unsafe fn from_raw<'a>(ptr: *const bindings::workqueue_struct) -> &'a Queue {
         // SAFETY: The `Queue` type is `#[repr(transparent)]`, so the pointer cast is valid. The
         // caller promises that the pointer is not dangling.
@@ -199,7 +198,11 @@ impl Queue {
         // stay valid until we call the function pointer in the `work_struct`, so the access is ok.
         unsafe {
             w.__enqueue(move |work_ptr| {
-                bindings::queue_work_on(bindings::WORK_CPU_UNBOUND as _, queue_ptr, work_ptr)
+                bindings::queue_work_on(
+                    bindings::wq_misc_consts_WORK_CPU_UNBOUND as _,
+                    queue_ptr,
+                    work_ptr,
+                )
             })
         }
     }
@@ -218,7 +221,9 @@ impl Queue {
     }
 }
 
-/// A helper type used in `try_spawn`.
+/// A helper type used in [`try_spawn`].
+///
+/// [`try_spawn`]: Queue::try_spawn
 #[pin_data]
 struct ClosureWork<T> {
     #[pin]
@@ -253,14 +258,16 @@ impl<T: FnOnce()> WorkItem for ClosureWork<T> {
 /// actual value of the id is not important as long as you use different ids for different fields
 /// of the same struct. (Fields of different structs need not use different ids.)
 ///
-/// Note that the id is used only to select the right method to call during compilation. It wont be
+/// Note that the id is used only to select the right method to call during compilation. It won't be
 /// part of the final executable.
 ///
 /// # Safety
 ///
-/// Implementers must ensure that any pointers passed to a `queue_work_on` closure by `__enqueue`
+/// Implementers must ensure that any pointers passed to a `queue_work_on` closure by [`__enqueue`]
 /// remain valid for the duration specified in the guarantees section of the documentation for
-/// `__enqueue`.
+/// [`__enqueue`].
+///
+/// [`__enqueue`]: RawWorkItem::__enqueue
 pub unsafe trait RawWorkItem<const ID: u64> {
     /// The return type of [`Queue::enqueue`].
     type EnqueueOutput;
@@ -290,10 +297,11 @@ pub unsafe trait RawWorkItem<const ID: u64> {
 
 /// Defines the method that should be called directly when a work item is executed.
 ///
-/// This trait is implemented by `Pin<Box<T>>` and `Arc<T>`, and is mainly intended to be
+/// This trait is implemented by `Pin<Box<T>>` and [`Arc<T>`], and is mainly intended to be
 /// implemented for smart pointer types. For your own structs, you would implement [`WorkItem`]
-/// instead. The `run` method on this trait will usually just perform the appropriate
-/// `container_of` translation and then call into the `run` method from the [`WorkItem`] trait.
+/// instead. The [`run`] method on this trait will usually just perform the appropriate
+/// `container_of` translation and then call into the [`run`][WorkItem::run] method from the
+/// [`WorkItem`] trait.
 ///
 /// This trait is used when the `work_struct` field is defined using the [`Work`] helper.
 ///
@@ -309,8 +317,10 @@ pub unsafe trait WorkItemPointer<const ID: u64>: RawWorkItem<ID> {
     ///
     /// # Safety
     ///
-    /// The provided `work_struct` pointer must originate from a previous call to `__enqueue` where
-    /// the `queue_work_on` closure returned true, and the pointer must still be valid.
+    /// The provided `work_struct` pointer must originate from a previous call to [`__enqueue`]
+    /// where the `queue_work_on` closure returned true, and the pointer must still be valid.
+    ///
+    /// [`__enqueue`]: RawWorkItem::__enqueue
     unsafe extern "C" fn run(ptr: *mut bindings::work_struct);
 }
 
@@ -328,12 +338,14 @@ pub trait WorkItem<const ID: u64 = 0> {
 
 /// Links for a work item.
 ///
-/// This struct contains a function pointer to the `run` function from the [`WorkItemPointer`]
+/// This struct contains a function pointer to the [`run`] function from the [`WorkItemPointer`]
 /// trait, and defines the linked list pointers necessary to enqueue a work item in a workqueue.
 ///
 /// Wraps the kernel's C `struct work_struct`.
 ///
 /// This is a helper type used to associate a `work_struct` with the [`WorkItem`] that uses it.
+///
+/// [`run`]: WorkItemPointer::run
 #[repr(transparent)]
 pub struct Work<T: ?Sized, const ID: u64 = 0> {
     work: Opaque<bindings::work_struct>,
@@ -396,9 +408,8 @@ impl<T: ?Sized, const ID: u64> Work<T, ID> {
 /// like this:
 ///
 /// ```no_run
-/// use kernel::impl_has_work;
 /// use kernel::prelude::*;
-/// use kernel::workqueue::Work;
+/// use kernel::workqueue::{impl_has_work, Work};
 ///
 /// struct MyWorkItem {
 ///     work_field: Work<MyWorkItem, 1>,
@@ -409,28 +420,25 @@ impl<T: ?Sized, const ID: u64> Work<T, ID> {
 /// }
 /// ```
 ///
-/// Note that since the `Work` type is annotated with an id, you can have several `work_struct`
+/// Note that since the [`Work`] type is annotated with an id, you can have several `work_struct`
 /// fields by using a different id for each one.
 ///
 /// # Safety
 ///
-/// The [`OFFSET`] constant must be the offset of a field in Self of type [`Work<T, ID>`]. The methods on
-/// this trait must have exactly the behavior that the definitions given below have.
+/// The [`OFFSET`] constant must be the offset of a field in `Self` of type [`Work<T, ID>`]. The
+/// methods on this trait must have exactly the behavior that the definitions given below have.
 ///
-/// [`Work<T, ID>`]: Work
 /// [`impl_has_work!`]: crate::impl_has_work
 /// [`OFFSET`]: HasWork::OFFSET
 pub unsafe trait HasWork<T, const ID: u64 = 0> {
     /// The offset of the [`Work<T, ID>`] field.
-    ///
-    /// [`Work<T, ID>`]: Work
     const OFFSET: usize;
 
     /// Returns the offset of the [`Work<T, ID>`] field.
     ///
-    /// This method exists because the [`OFFSET`] constant cannot be accessed if the type is not Sized.
+    /// This method exists because the [`OFFSET`] constant cannot be accessed if the type is not
+    /// [`Sized`].
     ///
-    /// [`Work<T, ID>`]: Work
     /// [`OFFSET`]: HasWork::OFFSET
     #[inline]
     fn get_work_offset(&self) -> usize {
@@ -442,8 +450,6 @@ pub unsafe trait HasWork<T, const ID: u64 = 0> {
     /// # Safety
     ///
     /// The provided pointer must point at a valid struct of type `Self`.
-    ///
-    /// [`Work<T, ID>`]: Work
     #[inline]
     unsafe fn raw_get_work(ptr: *mut Self) -> *mut Work<T, ID> {
         // SAFETY: The caller promises that the pointer is valid.
@@ -455,8 +461,6 @@ pub unsafe trait HasWork<T, const ID: u64 = 0> {
     /// # Safety
     ///
     /// The pointer must point at a [`Work<T, ID>`] field in a struct of type `Self`.
-    ///
-    /// [`Work<T, ID>`]: Work
     #[inline]
     unsafe fn work_container_of(ptr: *mut Work<T, ID>) -> *mut Self
     where
@@ -473,9 +477,8 @@ pub unsafe trait HasWork<T, const ID: u64 = 0> {
 /// # Examples
 ///
 /// ```
-/// use kernel::impl_has_work;
 /// use kernel::sync::Arc;
-/// use kernel::workqueue::{self, Work};
+/// use kernel::workqueue::{self, impl_has_work, Work};
 ///
 /// struct MyStruct {
 ///     work_field: Work<MyStruct, 17>,
@@ -485,8 +488,6 @@ pub unsafe trait HasWork<T, const ID: u64 = 0> {
 ///     impl HasWork<MyStruct, 17> for MyStruct { self.work_field }
 /// }
 /// ```
-///
-/// [`HasWork<T, ID>`]: HasWork
 #[macro_export]
 macro_rules! impl_has_work {
     ($(impl$(<$($implarg:ident),*>)?
@@ -509,6 +510,7 @@ macro_rules! impl_has_work {
         }
     )*};
 }
+pub use impl_has_work;
 
 impl_has_work! {
     impl<T> HasWork<Self> for ClosureWork<T> { self.work }