projects/linux·blob v6.3 · refs

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