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