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))] 20 compile_error!("Missing kernel configuration for conditional compilation"); 21 22 #[cfg(not(test))] 23 #[cfg(not(testlib))] 24 mod allocator; 25 pub mod error; 26 pub mod prelude; 27 pub mod print; 28 pub mod str; 29 30 #[doc(hidden)] 31 pub use bindings; 32 pub use macros; 33 34 /// Prefix to appear before log messages printed from within the `kernel` crate. 35 const __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`]. 40 pub 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` 53 pub struct ThisModule(*mut bindings::module); 54 55 // SAFETY: `THIS_MODULE` may be used from all threads within a module. 56 unsafe impl Sync for ThisModule {} 57 58 impl 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] 71 fn 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 } 79