// SPDX-License-Identifier: GPL-2.0 //! The `kernel` crate.//!//! This crate contains the kernel APIs that have been ported or wrapped for//! 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`] 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. #![no_std]//// Please see https://github.com/Rust-for-Linux/linux/issues/2 for details on// the unstable features in use.//// Stable since Rust 1.79.0.#![feature(generic_nonzero)]#![feature(inline_const)]#![feature(pointer_is_aligned)]#![feature(slice_ptr_len)]//// Stable since Rust 1.80.0.#![feature(slice_flatten)]//// Stable since Rust 1.81.0.#![feature(lint_reasons)]//// Stable since Rust 1.82.0.#![feature(raw_ref_op)]//// Stable since Rust 1.83.0.#![feature(const_maybe_uninit_as_mut_ptr)]#![feature(const_mut_refs)]#![feature(const_option)]#![feature(const_ptr_write)]#![feature(const_refs_to_cell)]//// Stable since Rust 1.84.0.#![feature(strict_provenance)]//// Expected to become stable.#![feature(arbitrary_self_types)]//// To be determined.#![feature(used_with_arg)]//// `feature(derive_coerce_pointee)` is expected to become stable. Before Rust// 1.84.0, it did not exist, so enable the predecessor features.#![cfg_attr(CONFIG_RUSTC_HAS_COERCE_POINTEE, feature(derive_coerce_pointee))]#![cfg_attr(not(CONFIG_RUSTC_HAS_COERCE_POINTEE), feature(coerce_unsized))]#![cfg_attr(not(CONFIG_RUSTC_HAS_COERCE_POINTEE), feature(dispatch_from_dyn))]#![cfg_attr(not(CONFIG_RUSTC_HAS_COERCE_POINTEE), feature(unsize))]//// `feature(file_with_nul)` is expected to become stable. Before Rust 1.89.0, it did not exist, so// enable it conditionally.#![cfg_attr(CONFIG_RUSTC_HAS_FILE_WITH_NUL, feature(file_with_nul))] // Ensure conditional compilation based on the kernel configuration works;// otherwise we may silently break things like initcall handling.#[cfg(not(CONFIG_RUST))]compile_error!("Missing kernel configuration for conditional compilation"); // Allow proc-macros to refer to `::kernel` inside the `kernel` crate (this crate).extern crate self as kernel; pub use ffi; pub mod acpi;pub mod alloc;#[cfg(CONFIG_AUXILIARY_BUS)]pub mod auxiliary;pub mod bitmap;pub mod bits;#[cfg(CONFIG_BLOCK)]pub mod block;pub mod bug;#[doc(hidden)]pub mod build_assert;pub mod clk;#[cfg(CONFIG_CONFIGFS_FS)]pub mod configfs;pub mod cpu;#[cfg(CONFIG_CPU_FREQ)]pub mod cpufreq;pub mod cpumask;pub mod cred;pub mod debugfs;pub mod device;pub mod device_id;pub mod devres;pub mod dma;pub mod driver;#[cfg(CONFIG_DRM = "y")]pub mod drm;pub mod error;pub mod faux;#[cfg(CONFIG_RUST_FW_LOADER_ABSTRACTIONS)]pub mod firmware;pub mod fmt;pub mod fs;#[cfg(CONFIG_I2C = "y")]pub mod i2c;pub mod id_pool;#[doc(hidden)]pub mod impl_flags;pub mod init;pub mod io;pub mod ioctl;pub mod iommu;pub mod iov;pub mod irq;pub mod jump_label;#[cfg(CONFIG_KUNIT)]pub mod kunit;pub mod list;pub mod maple_tree;pub mod miscdevice;pub mod mm;pub mod module_param;#[cfg(CONFIG_NET)]pub mod net;pub mod num;pub mod of;#[cfg(CONFIG_PM_OPP)]pub mod opp;pub mod page;#[cfg(CONFIG_PCI)]pub mod pci;pub mod pid_namespace;pub mod platform;pub mod prelude;pub mod print;pub mod processor;pub mod ptr;#[cfg(CONFIG_RUST_PWM_ABSTRACTIONS)]pub mod pwm;pub mod rbtree;pub mod regulator;pub mod revocable;pub mod safety;pub mod scatterlist;pub mod security;pub mod seq_file;pub mod sizes;pub mod slice;#[cfg(CONFIG_SOC_BUS)]pub mod soc;mod static_assert;#[doc(hidden)]pub mod std_vendor;pub mod str;pub mod sync;pub mod task;pub mod time;pub mod tracepoint;pub mod transmute;pub mod types;pub mod uaccess;#[cfg(CONFIG_USB = "y")]pub mod usb;pub mod workqueue;pub mod xarray; #[doc(hidden)]pub use bindings;pub use macros;pub use uapi; /// Prefix to appear before log messages printed from within the `kernel` crate.const __LOG_PREFIX: &[u8] = b"rust_kernel\0"; /// The top level entrypoint to implementing a kernel module.////// For any teardown or cleanup operations, your type may implement [`Drop`].pub trait Module: Sized + Sync + Send { /// Called at module initialization time. /// /// Use this method to perform whatever setup or registration your module /// should do. /// /// Equivalent to the `module_init` macro in the C API. fn init(module: &'static ThisModule) -> error::Result<Self>;} /// A module that is pinned and initialised in-place.pub trait InPlaceModule: Sync + Send { /// Creates an initialiser for the module. /// /// It is called when the module is loaded. fn init(module: &'static ThisModule) -> impl pin_init::PinInit<Self, error::Error>;} impl<T: Module> InPlaceModule for T { fn init(module: &'static ThisModule) -> impl pin_init::PinInit<Self, error::Error> { let initer = move |slot: *mut Self| { let m = <Self as Module>::init(module)?; // SAFETY: `slot` is valid for write per the contract with `pin_init_from_closure`. unsafe { slot.write(m) }; Ok(()) }; // SAFETY: On success, `initer` always fully initialises an instance of `Self`. unsafe { pin_init::pin_init_from_closure(initer) } }} /// Metadata attached to a [`Module`] or [`InPlaceModule`].pub trait ModuleMetadata { /// The name of the module as specified in the `module!` macro. const NAME: &'static crate::str::CStr;} /// Equivalent to `THIS_MODULE` in the C API.////// C header: [`include/linux/init.h`](srctree/include/linux/init.h)pub struct ThisModule(*mut bindings::module); // SAFETY: `THIS_MODULE` may be used from all threads within a module.unsafe impl Sync for ThisModule {} impl ThisModule { /// Creates a [`ThisModule`] given the `THIS_MODULE` pointer. /// /// # Safety /// /// The pointer must be equal to the right `THIS_MODULE`. pub const unsafe fn from_ptr(ptr: *mut bindings::module) -> ThisModule { ThisModule(ptr) } /// Access the raw pointer for this module. /// /// It is up to the user to use it correctly. pub const fn as_ptr(&self) -> *mut bindings::module { self.0 }} #[cfg(not(testlib))]#[panic_handler]fn panic(info: &core::panic::PanicInfo<'_>) -> ! { pr_emerg!("{}\n", info); // SAFETY: FFI call. unsafe { bindings::BUG() };} /// Produces a pointer to an object from a pointer to one of its fields.////// If you encounter a type mismatch due to the [`Opaque`] type, then use [`Opaque::cast_into`] or/// [`Opaque::cast_from`] to resolve the mismatch.////// [`Opaque`]: crate::types::Opaque/// [`Opaque::cast_into`]: crate::types::Opaque::cast_into/// [`Opaque::cast_from`]: crate::types::Opaque::cast_from////// # 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: *const _ = &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 { ($field_ptr:expr, $Container:ty, $($fields:tt)*) => {{ let offset: usize = ::core::mem::offset_of!($Container, $($fields)*); let field_ptr = $field_ptr; let container_ptr = field_ptr.byte_sub(offset).cast::<$Container>(); $crate::assert_same_type(field_ptr, (&raw const (*container_ptr).$($fields)*).cast_mut()); container_ptr }}} /// Helper for [`container_of!`].#[doc(hidden)]pub fn assert_same_type<T>(_: T, _: T) {} /// Helper for `.rs.S` files.#[doc(hidden)]#[macro_export]macro_rules! concat_literals { ($( $asm:literal )* ) => { ::core::concat!($($asm),*) };} /// Wrapper around `asm!` configured for use in the kernel.////// Uses a semicolon to avoid parsing ambiguities, even though this does not match native `asm!`/// syntax.// For x86, `asm!` uses intel syntax by default, but we want to use at&t syntax in the kernel.#[cfg(any(target_arch = "x86", target_arch = "x86_64"))]#[macro_export]macro_rules! asm { ($($asm:expr),* ; $($rest:tt)*) => { ::core::arch::asm!( $($asm)*, options(att_syntax), $($rest)* ) };} /// Wrapper around `asm!` configured for use in the kernel.////// Uses a semicolon to avoid parsing ambiguities, even though this does not match native `asm!`/// syntax.// For non-x86 arches we just pass through to `asm!`.#[cfg(not(any(target_arch = "x86", target_arch = "x86_64")))]#[macro_export]macro_rules! asm { ($($asm:expr),* ; $($rest:tt)*) => { ::core::arch::asm!( $($asm)*, $($rest)* ) };} /// Gets the C string file name of a [`Location`].////// If `Location::file_as_c_str()` is not available, returns a string that warns about it.////// [`Location`]: core::panic::Location////// # Examples////// ```/// # use kernel::file_from_location;////// #[track_caller]/// fn foo() {/// let caller = core::panic::Location::caller();////// // Output:/// // - A path like "rust/kernel/example.rs" if `file_as_c_str()` is available./// // - "<Location::file_as_c_str() not supported>" otherwise./// let caller_file = file_from_location(caller);////// // Prints out the message with caller's file name./// pr_info!("foo() called in file {caller_file:?}\n");////// # if cfg!(CONFIG_RUSTC_HAS_FILE_WITH_NUL) {/// # assert_eq!(Ok(caller.file()), caller_file.to_str());/// # }/// }////// # foo();/// ```#[inline]pub fn file_from_location<'a>(loc: &'a core::panic::Location<'a>) -> &'a core::ffi::CStr { #[cfg(CONFIG_RUSTC_HAS_FILE_AS_C_STR)] { loc.file_as_c_str() } #[cfg(all(CONFIG_RUSTC_HAS_FILE_WITH_NUL, not(CONFIG_RUSTC_HAS_FILE_AS_C_STR)))] { loc.file_with_nul() } #[cfg(not(CONFIG_RUSTC_HAS_FILE_WITH_NUL))] { let _ = loc; c"<Location::file_as_c_str() not supported>" }}
// SPDX-License-Identifier: GPL-2.0
//! The `kernel` crate.
//!
//! This crate contains the kernel APIs that have been ported or wrapped for
//! 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`] 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.
#![no_std]
//
// Please see https://github.com/Rust-for-Linux/linux/issues/2 for details on
// the unstable features in use.
//
// Stable since Rust 1.79.0.
#![feature(generic_nonzero)]
#![feature(inline_const)]
#![feature(pointer_is_aligned)]
#![feature(slice_ptr_len)]
//
// Stable since Rust 1.80.0.
#![feature(slice_flatten)]
//
// Stable since Rust 1.81.0.
#![feature(lint_reasons)]
//
// Stable since Rust 1.82.0.
#![feature(raw_ref_op)]
//
// Stable since Rust 1.83.0.
#![feature(const_maybe_uninit_as_mut_ptr)]
#![feature(const_mut_refs)]
#![feature(const_option)]
#![feature(const_ptr_write)]
#![feature(const_refs_to_cell)]
//
// Stable since Rust 1.84.0.
#![feature(strict_provenance)]
//
// Expected to become stable.
#![feature(arbitrary_self_types)]
//
// To be determined.
#![feature(used_with_arg)]
//
// `feature(derive_coerce_pointee)` is expected to become stable. Before Rust
// 1.84.0, it did not exist, so enable the predecessor features.
#![cfg_attr(CONFIG_RUSTC_HAS_COERCE_POINTEE, feature(derive_coerce_pointee))]
#![cfg_attr(not(CONFIG_RUSTC_HAS_COERCE_POINTEE), feature(coerce_unsized))]
#![cfg_attr(not(CONFIG_RUSTC_HAS_COERCE_POINTEE), feature(dispatch_from_dyn))]
#![cfg_attr(not(CONFIG_RUSTC_HAS_COERCE_POINTEE), feature(unsize))]
//
// `feature(file_with_nul)` is expected to become stable. Before Rust 1.89.0, it did not exist, so
// enable it conditionally.
#![cfg_attr(CONFIG_RUSTC_HAS_FILE_WITH_NUL, feature(file_with_nul))]
// Ensure conditional compilation based on the kernel configuration works;
// otherwise we may silently break things like initcall handling.
#[cfg(not(CONFIG_RUST))]
compile_error!("Missing kernel configuration for conditional compilation");
// Allow proc-macros to refer to `::kernel` inside the `kernel` crate (this crate).
extern crate self as kernel;
pub use ffi;
pub mod acpi;
pub mod alloc;
#[cfg(CONFIG_AUXILIARY_BUS)]
pub mod auxiliary;
pub mod bitmap;
pub mod bits;
#[cfg(CONFIG_BLOCK)]
pub mod block;
pub mod bug;
#[doc(hidden)]
pub mod build_assert;
pub mod clk;
#[cfg(CONFIG_CONFIGFS_FS)]
pub mod configfs;
pub mod cpu;
#[cfg(CONFIG_CPU_FREQ)]
pub mod cpufreq;
pub mod cpumask;
pub mod cred;
pub mod debugfs;
pub mod device;
pub mod device_id;
pub mod devres;
pub mod dma;
pub mod driver;
#[cfg(CONFIG_DRM = "y")]
pub mod drm;
pub mod error;
pub mod faux;
#[cfg(CONFIG_RUST_FW_LOADER_ABSTRACTIONS)]
pub mod firmware;
pub mod fmt;
pub mod fs;
#[cfg(CONFIG_I2C = "y")]
pub mod i2c;
pub mod id_pool;
#[doc(hidden)]
pub mod impl_flags;
pub mod init;
pub mod io;
pub mod ioctl;
pub mod iommu;
pub mod iov;
pub mod irq;
pub mod jump_label;
#[cfg(CONFIG_KUNIT)]
pub mod kunit;
pub mod list;
pub mod maple_tree;
pub mod miscdevice;
pub mod mm;
pub mod module_param;
#[cfg(CONFIG_NET)]
pub mod net;
pub mod num;
pub mod of;
#[cfg(CONFIG_PM_OPP)]
pub mod opp;
pub mod page;
#[cfg(CONFIG_PCI)]
pub mod pci;
pub mod pid_namespace;
pub mod platform;
pub mod prelude;
pub mod print;
pub mod processor;
pub mod ptr;
#[cfg(CONFIG_RUST_PWM_ABSTRACTIONS)]
pub mod pwm;
pub mod rbtree;
pub mod regulator;
pub mod revocable;
pub mod safety;
pub mod scatterlist;
pub mod security;
pub mod seq_file;
pub mod sizes;
pub mod slice;
#[cfg(CONFIG_SOC_BUS)]
pub mod soc;
mod static_assert;
#[doc(hidden)]
pub mod std_vendor;
pub mod str;
pub mod sync;
pub mod task;
pub mod time;
pub mod tracepoint;
pub mod transmute;
pub mod types;
pub mod uaccess;
#[cfg(CONFIG_USB = "y")]
pub mod usb;
pub mod workqueue;
pub mod xarray;
#[doc(hidden)]
pub use bindings;
pub use macros;
pub use uapi;
/// Prefix to appear before log messages printed from within the `kernel` crate.
const __LOG_PREFIX: &[u8] = b"rust_kernel\0";
/// The top level entrypoint to implementing a kernel module.
///
/// For any teardown or cleanup operations, your type may implement [`Drop`].
pub trait Module: Sized + Sync + Send {
/// Called at module initialization time.
///
/// Use this method to perform whatever setup or registration your module
/// should do.
///
/// Equivalent to the `module_init` macro in the C API.
fn init(module: &'static ThisModule) -> error::Result<Self>;
}
/// A module that is pinned and initialised in-place.
pub trait InPlaceModule: Sync + Send {
/// Creates an initialiser for the module.
///
/// It is called when the module is loaded.
fn init(module: &'static ThisModule) -> impl pin_init::PinInit<Self, error::Error>;
}
impl<T: Module> InPlaceModule for T {
fn init(module: &'static ThisModule) -> impl pin_init::PinInit<Self, error::Error> {
let initer = move |slot: *mut Self| {
let m = <Self as Module>::init(module)?;
// SAFETY: `slot` is valid for write per the contract with `pin_init_from_closure`.
unsafe { slot.write(m) };
Ok(())
};
// SAFETY: On success, `initer` always fully initialises an instance of `Self`.
unsafe { pin_init::pin_init_from_closure(initer) }
}
}
/// Metadata attached to a [`Module`] or [`InPlaceModule`].
pub trait ModuleMetadata {
/// The name of the module as specified in the `module!` macro.
const NAME: &'static crate::str::CStr;
}
/// Equivalent to `THIS_MODULE` in the C API.
///
/// C header: [`include/linux/init.h`](srctree/include/linux/init.h)
pub struct ThisModule(*mut bindings::module);
// SAFETY: `THIS_MODULE` may be used from all threads within a module.
unsafe impl Sync for ThisModule {}
impl ThisModule {
/// Creates a [`ThisModule`] given the `THIS_MODULE` pointer.
///
/// # Safety
///
/// The pointer must be equal to the right `THIS_MODULE`.
pub const unsafe fn from_ptr(ptr: *mut bindings::module) -> ThisModule {
ThisModule(ptr)
}
/// Access the raw pointer for this module.
///
/// It is up to the user to use it correctly.
pub const fn as_ptr(&self) -> *mut bindings::module {
self.0
}
}
#[cfg(not(testlib))]
#[panic_handler]
fn panic(info: &core::panic::PanicInfo<'_>) -> ! {
pr_emerg!("{}\n", info);
// SAFETY: FFI call.
unsafe { bindings::BUG() };
}
/// Produces a pointer to an object from a pointer to one of its fields.
///
/// If you encounter a type mismatch due to the [`Opaque`] type, then use [`Opaque::cast_into`] or
/// [`Opaque::cast_from`] to resolve the mismatch.
///
/// [`Opaque`]: crate::types::Opaque
/// [`Opaque::cast_into`]: crate::types::Opaque::cast_into
/// [`Opaque::cast_from`]: crate::types::Opaque::cast_from
///
/// # 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: *const _ = &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 {
($field_ptr:expr, $Container:ty, $($fields:tt)*) => {{
let offset: usize = ::core::mem::offset_of!($Container, $($fields)*);
let field_ptr = $field_ptr;
let container_ptr = field_ptr.byte_sub(offset).cast::<$Container>();
$crate::assert_same_type(field_ptr, (&raw const (*container_ptr).$($fields)*).cast_mut());
container_ptr
}}
}
/// Helper for [`container_of!`].
#[doc(hidden)]
pub fn assert_same_type<T>(_: T, _: T) {}
/// Helper for `.rs.S` files.
#[doc(hidden)]
#[macro_export]
macro_rules! concat_literals {
($( $asm:literal )* ) => {
::core::concat!($($asm),*)
};
}
/// Wrapper around `asm!` configured for use in the kernel.
///
/// Uses a semicolon to avoid parsing ambiguities, even though this does not match native `asm!`
/// syntax.
// For x86, `asm!` uses intel syntax by default, but we want to use at&t syntax in the kernel.
#[cfg(any(target_arch = "x86", target_arch = "x86_64"))]
#[macro_export]
macro_rules! asm {
($($asm:expr),* ; $($rest:tt)*) => {
::core::arch::asm!( $($asm)*, options(att_syntax), $($rest)* )
};
}
/// Wrapper around `asm!` configured for use in the kernel.
///
/// Uses a semicolon to avoid parsing ambiguities, even though this does not match native `asm!`
/// syntax.
// For non-x86 arches we just pass through to `asm!`.
#[cfg(not(any(target_arch = "x86", target_arch = "x86_64")))]
#[macro_export]
macro_rules! asm {
($($asm:expr),* ; $($rest:tt)*) => {
::core::arch::asm!( $($asm)*, $($rest)* )
};
}
/// Gets the C string file name of a [`Location`].
///
/// If `Location::file_as_c_str()` is not available, returns a string that warns about it.
///
/// [`Location`]: core::panic::Location
///
/// # Examples
///
/// ```
/// # use kernel::file_from_location;
///
/// #[track_caller]
/// fn foo() {
/// let caller = core::panic::Location::caller();
///
/// // Output:
/// // - A path like "rust/kernel/example.rs" if `file_as_c_str()` is available.
/// // - "<Location::file_as_c_str() not supported>" otherwise.
/// let caller_file = file_from_location(caller);
///
/// // Prints out the message with caller's file name.
/// pr_info!("foo() called in file {caller_file:?}\n");
///
/// # if cfg!(CONFIG_RUSTC_HAS_FILE_WITH_NUL) {
/// # assert_eq!(Ok(caller.file()), caller_file.to_str());
/// # }
/// }
///
/// # foo();
/// ```
#[inline]
pub fn file_from_location<'a>(loc: &'a core::panic::Location<'a>) -> &'a core::ffi::CStr {
#[cfg(CONFIG_RUSTC_HAS_FILE_AS_C_STR)]
{
loc.file_as_c_str()
}
#[cfg(all(CONFIG_RUSTC_HAS_FILE_WITH_NUL, not(CONFIG_RUSTC_HAS_FILE_AS_C_STR)))]
{
loc.file_with_nul()
}
#[cfg(not(CONFIG_RUSTC_HAS_FILE_WITH_NUL))]
{
let _ = loc;
c"<Location::file_as_c_str() not supported>"
}
}