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))] 25 compile_error!("Missing kernel configuration for conditional compilation"); 26 27 // Allow proc-macros to refer to `::kernel` inside the `kernel` crate (this crate). 28 extern crate self as kernel; 29 30 #[cfg(not(test))] 31 #[cfg(not(testlib))] 32 mod allocator; 33 mod build_assert; 34 pub mod error; 35 pub mod init; 36 pub mod ioctl; 37 pub mod prelude; 38 pub mod print; 39 mod static_assert; 40 #[doc(hidden)] 41 pub mod std_vendor; 42 pub mod str; 43 pub mod sync; 44 pub mod task; 45 pub mod types; 46 47 #[doc(hidden)] 48 pub use bindings; 49 pub use macros; 50 pub use uapi; 51 52 #[doc(hidden)] 53 pub use build_error::build_error; 54 55 /// Prefix to appear before log messages printed from within the `kernel` crate. 56 const __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`]. 61 pub 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` 74 pub struct ThisModule(*mut bindings::module); 75 76 // SAFETY: `THIS_MODULE` may be used from all threads within a module. 77 unsafe impl Sync for ThisModule {} 78 79 impl 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] 92 fn 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 } 100