projects/linux·blob v6.12 · refs

148 lines · 4.0 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;
41pub mod list;
42#[cfg(CONFIG_NET)]
43pub mod net;
44pub mod page;
45pub mod prelude;
46pub mod print;
47pub mod rbtree;
48pub mod sizes;
49mod static_assert;
50#[doc(hidden)]
51pub mod std_vendor;
52pub mod str;
53pub mod sync;
54pub mod task;
55pub mod time;
56pub mod types;
57pub mod uaccess;
58pub mod workqueue;
59
60#[doc(hidden)]
61pub use bindings;
62pub use macros;
63pub use uapi;
64
65#[doc(hidden)]
66pub use build_error::build_error;
67
68/// Prefix to appear before log messages printed from within the `kernel` crate.
69const __LOG_PREFIX: &[u8] = b"rust_kernel\0";
70
71/// The top level entrypoint to implementing a kernel module.
72///
73/// For any teardown or cleanup operations, your type may implement [`Drop`].
74pub trait Module: Sized + Sync + Send {
75 /// Called at module initialization time.
76 ///
77 /// Use this method to perform whatever setup or registration your module
78 /// should do.
79 ///
80 /// Equivalent to the `module_init` macro in the C API.
81 fn init(module: &'static ThisModule) -> error::Result<Self>;
82}
83
84/// Equivalent to `THIS_MODULE` in the C API.
85///
86/// C header: [`include/linux/export.h`](srctree/include/linux/export.h)
87pub struct ThisModule(*mut bindings::module);
88
89// SAFETY: `THIS_MODULE` may be used from all threads within a module.
90unsafe impl Sync for ThisModule {}
91
92impl ThisModule {
93 /// Creates a [`ThisModule`] given the `THIS_MODULE` pointer.
94 ///
95 /// # Safety
96 ///
97 /// The pointer must be equal to the right `THIS_MODULE`.
98 pub const unsafe fn from_ptr(ptr: *mut bindings::module) -> ThisModule {
99 ThisModule(ptr)
100 }
101
102 /// Access the raw pointer for this module.
103 ///
104 /// It is up to the user to use it correctly.
105 pub const fn as_ptr(&self) -> *mut bindings::module {
106 self.0
107 }
108}
109
110#[cfg(not(any(testlib, test)))]
111#[panic_handler]
112fn panic(info: &core::panic::PanicInfo<'_>) -> ! {
113 pr_emerg!("{}\n", info);
114 // SAFETY: FFI call.
115 unsafe { bindings::BUG() };
116}
117
118/// Produces a pointer to an object from a pointer to one of its fields.
119///
120/// # Safety
121///
122/// The pointer passed to this macro, and the pointer returned by this macro, must both be in
123/// bounds of the same allocation.
124///
125/// # Examples
126///
127/// ```
128/// # use kernel::container_of;
129/// struct Test {
130/// a: u64,
131/// b: u32,
132/// }
133///
134/// let test = Test { a: 10, b: 20 };
135/// let b_ptr = &test.b;
136/// // SAFETY: The pointer points at the `b` field of a `Test`, so the resulting pointer will be
137/// // in-bounds of the same allocation as `b_ptr`.
138/// let test_alias = unsafe { container_of!(b_ptr, Test, b) };
139/// assert!(core::ptr::eq(&test, test_alias));
140/// ```
141#[macro_export]
142macro_rules! container_of {
143 ($ptr:expr, $type:ty, $($f:tt)*) => {{
144 let ptr = $ptr as *const _ as *const u8;
145 let offset: usize = ::core::mem::offset_of!($type, $($f)*);
146 ptr.sub(offset) as *const $type
147 }}
148}