xref: /linux/rust/kernel/lib.rs (revision d642ef71)
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(offset_of)]
20 #![feature(ptr_metadata)]
21 #![feature(receiver_trait)]
22 #![feature(unsize)]
23 
24 // Ensure conditional compilation based on the kernel configuration works;
25 // otherwise we may silently break things like initcall handling.
26 #[cfg(not(CONFIG_RUST))]
27 compile_error!("Missing kernel configuration for conditional compilation");
28 
29 // Allow proc-macros to refer to `::kernel` inside the `kernel` crate (this crate).
30 extern crate self as kernel;
31 
32 #[cfg(not(test))]
33 #[cfg(not(testlib))]
34 mod allocator;
35 mod build_assert;
36 pub mod error;
37 pub mod init;
38 pub mod ioctl;
39 #[cfg(CONFIG_KUNIT)]
40 pub mod kunit;
41 pub mod prelude;
42 pub mod print;
43 mod static_assert;
44 #[doc(hidden)]
45 pub mod std_vendor;
46 pub mod str;
47 pub mod sync;
48 pub mod task;
49 pub mod types;
50 pub mod workqueue;
51 
52 #[doc(hidden)]
53 pub use bindings;
54 pub use macros;
55 pub use uapi;
56 
57 #[doc(hidden)]
58 pub use build_error::build_error;
59 
60 /// Prefix to appear before log messages printed from within the `kernel` crate.
61 const __LOG_PREFIX: &[u8] = b"rust_kernel\0";
62 
63 /// The top level entrypoint to implementing a kernel module.
64 ///
65 /// For any teardown or cleanup operations, your type may implement [`Drop`].
66 pub trait Module: Sized + Sync {
67     /// Called at module initialization time.
68     ///
69     /// Use this method to perform whatever setup or registration your module
70     /// should do.
71     ///
72     /// Equivalent to the `module_init` macro in the C API.
73     fn init(module: &'static ThisModule) -> error::Result<Self>;
74 }
75 
76 /// Equivalent to `THIS_MODULE` in the C API.
77 ///
78 /// C header: `include/linux/export.h`
79 pub struct ThisModule(*mut bindings::module);
80 
81 // SAFETY: `THIS_MODULE` may be used from all threads within a module.
82 unsafe impl Sync for ThisModule {}
83 
84 impl ThisModule {
85     /// Creates a [`ThisModule`] given the `THIS_MODULE` pointer.
86     ///
87     /// # Safety
88     ///
89     /// The pointer must be equal to the right `THIS_MODULE`.
90     pub const unsafe fn from_ptr(ptr: *mut bindings::module) -> ThisModule {
91         ThisModule(ptr)
92     }
93 }
94 
95 #[cfg(not(any(testlib, test)))]
96 #[panic_handler]
97 fn panic(info: &core::panic::PanicInfo<'_>) -> ! {
98     pr_emerg!("{}\n", info);
99     // SAFETY: FFI call.
100     unsafe { bindings::BUG() };
101 }
102