projects/linux·blob v6.5 · refs

99 lines · 2.8 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(allocator_api)]
16#![feature(coerce_unsized)]
17#![feature(dispatch_from_dyn)]
18#![feature(new_uninit)]
19#![feature(receiver_trait)]
20#![feature(unsize)]
21
22// Ensure conditional compilation based on the kernel configuration works;
23// otherwise we may silently break things like initcall handling.
24#[cfg(not(CONFIG_RUST))]
25compile_error!("Missing kernel configuration for conditional compilation");
26
27// Allow proc-macros to refer to `::kernel` inside the `kernel` crate (this crate).
28extern crate self as kernel;
29
30#[cfg(not(test))]
31#[cfg(not(testlib))]
32mod allocator;
33mod build_assert;
34pub mod error;
35pub mod init;
36pub mod ioctl;
37pub mod prelude;
38pub mod print;
39mod static_assert;
40#[doc(hidden)]
41pub mod std_vendor;
42pub mod str;
43pub mod sync;
44pub mod task;
45pub mod types;
46
47#[doc(hidden)]
48pub use bindings;
49pub use macros;
50pub use uapi;
51
52#[doc(hidden)]
53pub use build_error::build_error;
54
55/// Prefix to appear before log messages printed from within the `kernel` crate.
56const __LOG_PREFIX: &[u8] = b"rust_kernel\0";
57
58/// The top level entrypoint to implementing a kernel module.
59///
60/// For any teardown or cleanup operations, your type may implement [`Drop`].
61pub trait Module: Sized + Sync {
62 /// Called at module initialization time.
63 ///
64 /// Use this method to perform whatever setup or registration your module
65 /// should do.
66 ///
67 /// Equivalent to the `module_init` macro in the C API.
68 fn init(module: &'static ThisModule) -> error::Result<Self>;
69}
70
71/// Equivalent to `THIS_MODULE` in the C API.
72///
73/// C header: `include/linux/export.h`
74pub struct ThisModule(*mut bindings::module);
75
76// SAFETY: `THIS_MODULE` may be used from all threads within a module.
77unsafe impl Sync for ThisModule {}
78
79impl ThisModule {
80 /// Creates a [`ThisModule`] given the `THIS_MODULE` pointer.
81 ///
82 /// # Safety
83 ///
84 /// The pointer must be equal to the right `THIS_MODULE`.
85 pub const unsafe fn from_ptr(ptr: *mut bindings::module) -> ThisModule {
86 ThisModule(ptr)
87 }
88}
89
90#[cfg(not(any(testlib, test)))]
91#[panic_handler]
92fn panic(info: &core::panic::PanicInfo<'_>) -> ! {
93 pr_emerg!("{}\n", info);
94 // SAFETY: FFI call.
95 unsafe { bindings::BUG() };
96 // Bindgen currently does not recognize `__noreturn` so `BUG` returns `()`
97 // instead of `!`. See <https://github.com/rust-lang/rust-bindgen/issues/2094>.
98 loop {}
99}