projects/linux·blob v6.11 · refs

145 lines · 3.9 KiB

1// SPDX-License-Identifier: GPL-2.0
2
3//! The `kernel` crate.
4//!
5//! This crate contains the kernel APIs that have been ported or wrapped for
6//! usage by Rust code in the kernel and is shared by all of them.
7//!
8//! In other words, all the rest of the Rust code in the kernel (e.g. kernel
9//! modules written in Rust) depends on [`core`], [`alloc`] and this crate.
10//!
11//! If you need a kernel C API that is not ported or wrapped yet here, then
12//! do so first instead of bypassing this crate.
13
14#![no_std]
15#![feature(coerce_unsized)]
16#![feature(dispatch_from_dyn)]
17#![feature(new_uninit)]
18#![feature(receiver_trait)]
19#![feature(unsize)]
20
21// Ensure conditional compilation based on the kernel configuration works;
22// otherwise we may silently break things like initcall handling.
23#[cfg(not(CONFIG_RUST))]
24compile_error!("Missing kernel configuration for conditional compilation");
25
26// Allow proc-macros to refer to `::kernel` inside the `kernel` crate (this crate).
27extern crate self as kernel;
28
29pub mod alloc;
30#[cfg(CONFIG_BLOCK)]
31pub mod block;
32mod build_assert;
33pub mod device;
34pub mod error;
35#[cfg(CONFIG_RUST_FW_LOADER_ABSTRACTIONS)]
36pub mod firmware;
37pub mod init;
38pub mod ioctl;
39#[cfg(CONFIG_KUNIT)]
40pub mod kunit;
41#[cfg(CONFIG_NET)]
42pub mod net;
43pub mod page;
44pub mod prelude;
45pub mod print;
46mod static_assert;
47#[doc(hidden)]
48pub mod std_vendor;
49pub mod str;
50pub mod sync;
51pub mod task;
52pub mod time;
53pub mod types;
54pub mod uaccess;
55pub mod workqueue;
56
57#[doc(hidden)]
58pub use bindings;
59pub use macros;
60pub use uapi;
61
62#[doc(hidden)]
63pub use build_error::build_error;
64
65/// Prefix to appear before log messages printed from within the `kernel` crate.
66const __LOG_PREFIX: &[u8] = b"rust_kernel\0";
67
68/// The top level entrypoint to implementing a kernel module.
69///
70/// For any teardown or cleanup operations, your type may implement [`Drop`].
71pub trait Module: Sized + Sync + Send {
72 /// Called at module initialization time.
73 ///
74 /// Use this method to perform whatever setup or registration your module
75 /// should do.
76 ///
77 /// Equivalent to the `module_init` macro in the C API.
78 fn init(module: &'static ThisModule) -> error::Result<Self>;
79}
80
81/// Equivalent to `THIS_MODULE` in the C API.
82///
83/// C header: [`include/linux/export.h`](srctree/include/linux/export.h)
84pub struct ThisModule(*mut bindings::module);
85
86// SAFETY: `THIS_MODULE` may be used from all threads within a module.
87unsafe impl Sync for ThisModule {}
88
89impl ThisModule {
90 /// Creates a [`ThisModule`] given the `THIS_MODULE` pointer.
91 ///
92 /// # Safety
93 ///
94 /// The pointer must be equal to the right `THIS_MODULE`.
95 pub const unsafe fn from_ptr(ptr: *mut bindings::module) -> ThisModule {
96 ThisModule(ptr)
97 }
98
99 /// Access the raw pointer for this module.
100 ///
101 /// It is up to the user to use it correctly.
102 pub const fn as_ptr(&self) -> *mut bindings::module {
103 self.0
104 }
105}
106
107#[cfg(not(any(testlib, test)))]
108#[panic_handler]
109fn panic(info: &core::panic::PanicInfo<'_>) -> ! {
110 pr_emerg!("{}\n", info);
111 // SAFETY: FFI call.
112 unsafe { bindings::BUG() };
113}
114
115/// Produces a pointer to an object from a pointer to one of its fields.
116///
117/// # Safety
118///
119/// The pointer passed to this macro, and the pointer returned by this macro, must both be in
120/// bounds of the same allocation.
121///
122/// # Examples
123///
124/// ```
125/// # use kernel::container_of;
126/// struct Test {
127/// a: u64,
128/// b: u32,
129/// }
130///
131/// let test = Test { a: 10, b: 20 };
132/// let b_ptr = &test.b;
133/// // SAFETY: The pointer points at the `b` field of a `Test`, so the resulting pointer will be
134/// // in-bounds of the same allocation as `b_ptr`.
135/// let test_alias = unsafe { container_of!(b_ptr, Test, b) };
136/// assert!(core::ptr::eq(&test, test_alias));
137/// ```
138#[macro_export]
139macro_rules! container_of {
140 ($ptr:expr, $type:ty, $($f:tt)*) => {{
141 let ptr = $ptr as *const _ as *const u8;
142 let offset: usize = ::core::mem::offset_of!($type, $($f)*);
143 ptr.sub(offset) as *const $type
144 }}
145}