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(coerce_unsized)] 16 #![feature(dispatch_from_dyn)] 17 #![feature(new_uninit)] 18 #![feature(receiver_trait)] 19 #![feature(unsize)] 20 21 // Ensure conditional compilation based on the kernel configuration works; 22 // otherwise we may silently break things like initcall handling. 23 #[cfg(not(CONFIG_RUST))] 24 compile_error!("Missing kernel configuration for conditional compilation"); 25 26 // Allow proc-macros to refer to `::kernel` inside the `kernel` crate (this crate). 27 extern crate self as kernel; 28 29 pub mod alloc; 30 mod build_assert; 31 pub mod device; 32 pub mod error; 33 #[cfg(CONFIG_RUST_FW_LOADER_ABSTRACTIONS)] 34 pub mod firmware; 35 pub mod init; 36 pub mod ioctl; 37 #[cfg(CONFIG_KUNIT)] 38 pub mod kunit; 39 #[cfg(CONFIG_NET)] 40 pub mod net; 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 time; 50 pub mod types; 51 pub mod workqueue; 52 53 #[doc(hidden)] 54 pub use bindings; 55 pub use macros; 56 pub use uapi; 57 58 #[doc(hidden)] 59 pub use build_error::build_error; 60 61 /// Prefix to appear before log messages printed from within the `kernel` crate. 62 const __LOG_PREFIX: &[u8] = b"rust_kernel\0"; 63 64 /// The top level entrypoint to implementing a kernel module. 65 /// 66 /// For any teardown or cleanup operations, your type may implement [`Drop`]. 67 pub trait Module: Sized + Sync + Send { 68 /// Called at module initialization time. 69 /// 70 /// Use this method to perform whatever setup or registration your module 71 /// should do. 72 /// 73 /// Equivalent to the `module_init` macro in the C API. 74 fn init(module: &'static ThisModule) -> error::Result<Self>; 75 } 76 77 /// Equivalent to `THIS_MODULE` in the C API. 78 /// 79 /// C header: [`include/linux/export.h`](srctree/include/linux/export.h) 80 pub struct ThisModule(*mut bindings::module); 81 82 // SAFETY: `THIS_MODULE` may be used from all threads within a module. 83 unsafe impl Sync for ThisModule {} 84 85 impl ThisModule { 86 /// Creates a [`ThisModule`] given the `THIS_MODULE` pointer. 87 /// 88 /// # Safety 89 /// 90 /// The pointer must be equal to the right `THIS_MODULE`. 91 pub const unsafe fn from_ptr(ptr: *mut bindings::module) -> ThisModule { 92 ThisModule(ptr) 93 } 94 95 /// Access the raw pointer for this module. 96 /// 97 /// It is up to the user to use it correctly. 98 pub const fn as_ptr(&self) -> *mut bindings::module { 99 self.0 100 } 101 } 102 103 #[cfg(not(any(testlib, test)))] 104 #[panic_handler] 105 fn panic(info: &core::panic::PanicInfo<'_>) -> ! { 106 pr_emerg!("{}\n", info); 107 // SAFETY: FFI call. 108 unsafe { bindings::BUG() }; 109 } 110 111 /// Produces a pointer to an object from a pointer to one of its fields. 112 /// 113 /// # Safety 114 /// 115 /// The pointer passed to this macro, and the pointer returned by this macro, must both be in 116 /// bounds of the same allocation. 117 /// 118 /// # Examples 119 /// 120 /// ``` 121 /// # use kernel::container_of; 122 /// struct Test { 123 /// a: u64, 124 /// b: u32, 125 /// } 126 /// 127 /// let test = Test { a: 10, b: 20 }; 128 /// let b_ptr = &test.b; 129 /// // SAFETY: The pointer points at the `b` field of a `Test`, so the resulting pointer will be 130 /// // in-bounds of the same allocation as `b_ptr`. 131 /// let test_alias = unsafe { container_of!(b_ptr, Test, b) }; 132 /// assert!(core::ptr::eq(&test, test_alias)); 133 /// ``` 134 #[macro_export] 135 macro_rules! container_of { 136 ($ptr:expr, $type:ty, $($f:tt)*) => {{ 137 let ptr = $ptr as *const _ as *const u8; 138 let offset: usize = ::core::mem::offset_of!($type, $($f)*); 139 ptr.sub(offset) as *const $type 140 }} 141 } 142