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 #[cfg(CONFIG_BLOCK)] 31 pub mod block; 32 mod build_assert; 33 pub mod device; 34 pub mod error; 35 #[cfg(CONFIG_RUST_FW_LOADER_ABSTRACTIONS)] 36 pub mod firmware; 37 pub mod init; 38 pub mod ioctl; 39 #[cfg(CONFIG_KUNIT)] 40 pub mod kunit; 41 pub mod list; 42 #[cfg(CONFIG_NET)] 43 pub mod net; 44 pub mod page; 45 pub mod prelude; 46 pub mod print; 47 pub mod rbtree; 48 pub mod sizes; 49 mod static_assert; 50 #[doc(hidden)] 51 pub mod std_vendor; 52 pub mod str; 53 pub mod sync; 54 pub mod task; 55 pub mod time; 56 pub mod types; 57 pub mod uaccess; 58 pub mod workqueue; 59 60 #[doc(hidden)] 61 pub use bindings; 62 pub use macros; 63 pub use uapi; 64 65 #[doc(hidden)] 66 pub use build_error::build_error; 67 68 /// Prefix to appear before log messages printed from within the `kernel` crate. 69 const __LOG_PREFIX: &[u8] = b"rust_kernel\0"; 70 71 /// The top level entrypoint to implementing a kernel module. 72 /// 73 /// For any teardown or cleanup operations, your type may implement [`Drop`]. 74 pub trait Module: Sized + Sync + Send { 75 /// Called at module initialization time. 76 /// 77 /// Use this method to perform whatever setup or registration your module 78 /// should do. 79 /// 80 /// Equivalent to the `module_init` macro in the C API. 81 fn init(module: &'static ThisModule) -> error::Result<Self>; 82 } 83 84 /// Equivalent to `THIS_MODULE` in the C API. 85 /// 86 /// C header: [`include/linux/export.h`](srctree/include/linux/export.h) 87 pub struct ThisModule(*mut bindings::module); 88 89 // SAFETY: `THIS_MODULE` may be used from all threads within a module. 90 unsafe impl Sync for ThisModule {} 91 92 impl ThisModule { 93 /// Creates a [`ThisModule`] given the `THIS_MODULE` pointer. 94 /// 95 /// # Safety 96 /// 97 /// The pointer must be equal to the right `THIS_MODULE`. 98 pub const unsafe fn from_ptr(ptr: *mut bindings::module) -> ThisModule { 99 ThisModule(ptr) 100 } 101 102 /// Access the raw pointer for this module. 103 /// 104 /// It is up to the user to use it correctly. 105 pub const fn as_ptr(&self) -> *mut bindings::module { 106 self.0 107 } 108 } 109 110 #[cfg(not(any(testlib, test)))] 111 #[panic_handler] 112 fn panic(info: &core::panic::PanicInfo<'_>) -> ! { 113 pr_emerg!("{}\n", info); 114 // SAFETY: FFI call. 115 unsafe { bindings::BUG() }; 116 } 117 118 /// Produces a pointer to an object from a pointer to one of its fields. 119 /// 120 /// # Safety 121 /// 122 /// The pointer passed to this macro, and the pointer returned by this macro, must both be in 123 /// bounds of the same allocation. 124 /// 125 /// # Examples 126 /// 127 /// ``` 128 /// # use kernel::container_of; 129 /// struct Test { 130 /// a: u64, 131 /// b: u32, 132 /// } 133 /// 134 /// let test = Test { a: 10, b: 20 }; 135 /// let b_ptr = &test.b; 136 /// // SAFETY: The pointer points at the `b` field of a `Test`, so the resulting pointer will be 137 /// // in-bounds of the same allocation as `b_ptr`. 138 /// let test_alias = unsafe { container_of!(b_ptr, Test, b) }; 139 /// assert!(core::ptr::eq(&test, test_alias)); 140 /// ``` 141 #[macro_export] 142 macro_rules! container_of { 143 ($ptr:expr, $type:ty, $($f:tt)*) => {{ 144 let ptr = $ptr as *const _ as *const u8; 145 let offset: usize = ::core::mem::offset_of!($type, $($f)*); 146 ptr.sub(offset) as *const $type 147 }} 148 } 149