projects/linux·blob v6.1 · refs

78 lines · 2.4 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(core_ffi_c)]
16
17// Ensure conditional compilation based on the kernel configuration works;
18// otherwise we may silently break things like initcall handling.
19#[cfg(not(CONFIG_RUST))]
20compile_error!("Missing kernel configuration for conditional compilation");
21
22#[cfg(not(test))]
23#[cfg(not(testlib))]
24mod allocator;
25pub mod error;
26pub mod prelude;
27pub mod print;
28pub mod str;
29
30#[doc(hidden)]
31pub use bindings;
32pub use macros;
33
34/// Prefix to appear before log messages printed from within the `kernel` crate.
35const __LOG_PREFIX: &[u8] = b"rust_kernel\0";
36
37/// The top level entrypoint to implementing a kernel module.
38///
39/// For any teardown or cleanup operations, your type may implement [`Drop`].
40pub trait Module: Sized + Sync {
41 /// Called at module initialization time.
42 ///
43 /// Use this method to perform whatever setup or registration your module
44 /// should do.
45 ///
46 /// Equivalent to the `module_init` macro in the C API.
47 fn init(module: &'static ThisModule) -> error::Result<Self>;
48}
49
50/// Equivalent to `THIS_MODULE` in the C API.
51///
52/// C header: `include/linux/export.h`
53pub struct ThisModule(*mut bindings::module);
54
55// SAFETY: `THIS_MODULE` may be used from all threads within a module.
56unsafe impl Sync for ThisModule {}
57
58impl ThisModule {
59 /// Creates a [`ThisModule`] given the `THIS_MODULE` pointer.
60 ///
61 /// # Safety
62 ///
63 /// The pointer must be equal to the right `THIS_MODULE`.
64 pub const unsafe fn from_ptr(ptr: *mut bindings::module) -> ThisModule {
65 ThisModule(ptr)
66 }
67}
68
69#[cfg(not(any(testlib, test)))]
70#[panic_handler]
71fn panic(info: &core::panic::PanicInfo<'_>) -> ! {
72 pr_emerg!("{}\n", info);
73 // SAFETY: FFI call.
74 unsafe { bindings::BUG() };
75 // Bindgen currently does not recognize `__noreturn` so `BUG` returns `()`
76 // instead of `!`. See <https://github.com/rust-lang/rust-bindgen/issues/2094>.
77 loop {}
78}