projects/linux·blob v6.2 · 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(core_ffi_c)]
17
18// Ensure conditional compilation based on the kernel configuration works;
19// otherwise we may silently break things like initcall handling.
20#[cfg(not(CONFIG_RUST))]
21compile_error!("Missing kernel configuration for conditional compilation");
22
23#[cfg(not(test))]
24#[cfg(not(testlib))]
25mod allocator;
26mod build_assert;
27pub mod error;
28pub mod prelude;
29pub mod print;
30mod static_assert;
31#[doc(hidden)]
32pub mod std_vendor;
33pub mod str;
34pub mod types;
35
36#[doc(hidden)]
37pub use bindings;
38pub use macros;
39
40#[doc(hidden)]
41pub use build_error::build_error;
42
43/// Prefix to appear before log messages printed from within the `kernel` crate.
44const __LOG_PREFIX: &[u8] = b"rust_kernel\0";
45
46/// The top level entrypoint to implementing a kernel module.
47///
48/// For any teardown or cleanup operations, your type may implement [`Drop`].
49pub trait Module: Sized + Sync {
50 /// Called at module initialization time.
51 ///
52 /// Use this method to perform whatever setup or registration your module
53 /// should do.
54 ///
55 /// Equivalent to the `module_init` macro in the C API.
56 fn init(module: &'static ThisModule) -> error::Result<Self>;
57}
58
59/// Equivalent to `THIS_MODULE` in the C API.
60///
61/// C header: `include/linux/export.h`
62pub struct ThisModule(*mut bindings::module);
63
64// SAFETY: `THIS_MODULE` may be used from all threads within a module.
65unsafe impl Sync for ThisModule {}
66
67impl ThisModule {
68 /// Creates a [`ThisModule`] given the `THIS_MODULE` pointer.
69 ///
70 /// # Safety
71 ///
72 /// The pointer must be equal to the right `THIS_MODULE`.
73 pub const unsafe fn from_ptr(ptr: *mut bindings::module) -> ThisModule {
74 ThisModule(ptr)
75 }
76}
77
78#[cfg(not(any(testlib, test)))]
79#[panic_handler]
80fn panic(info: &core::panic::PanicInfo<'_>) -> ! {
81 pr_emerg!("{}\n", info);
82 // SAFETY: FFI call.
83 unsafe { bindings::BUG() };
84 // Bindgen currently does not recognize `__noreturn` so `BUG` returns `()`
85 // instead of `!`. See <https://github.com/rust-lang/rust-bindgen/issues/2094>.
86 loop {}
87}