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(arbitrary_self_types)] 16 #![feature(coerce_unsized)] 17 #![feature(dispatch_from_dyn)] 18 #![feature(inline_const)] 19 #![feature(lint_reasons)] 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 pub mod alloc; 31 #[cfg(CONFIG_BLOCK)] 32 pub mod block; 33 mod build_assert; 34 pub mod device; 35 pub mod error; 36 #[cfg(CONFIG_RUST_FW_LOADER_ABSTRACTIONS)] 37 pub mod firmware; 38 pub mod init; 39 pub mod ioctl; 40 #[cfg(CONFIG_KUNIT)] 41 pub mod kunit; 42 pub mod list; 43 #[cfg(CONFIG_NET)] 44 pub mod net; 45 pub mod page; 46 pub mod prelude; 47 pub mod print; 48 pub mod rbtree; 49 pub mod sizes; 50 mod static_assert; 51 #[doc(hidden)] 52 pub mod std_vendor; 53 pub mod str; 54 pub mod sync; 55 pub mod task; 56 pub mod time; 57 pub mod transmute; 58 pub mod types; 59 pub mod uaccess; 60 pub mod workqueue; 61 62 #[doc(hidden)] 63 pub use bindings; 64 pub use macros; 65 pub use uapi; 66 67 #[doc(hidden)] 68 pub use build_error::build_error; 69 70 /// Prefix to appear before log messages printed from within the `kernel` crate. 71 const __LOG_PREFIX: &[u8] = b"rust_kernel\0"; 72 73 /// The top level entrypoint to implementing a kernel module. 74 /// 75 /// For any teardown or cleanup operations, your type may implement [`Drop`]. 76 pub trait Module: Sized + Sync + Send { 77 /// Called at module initialization time. 78 /// 79 /// Use this method to perform whatever setup or registration your module 80 /// should do. 81 /// 82 /// Equivalent to the `module_init` macro in the C API. 83 fn init(module: &'static ThisModule) -> error::Result<Self>; 84 } 85 86 /// Equivalent to `THIS_MODULE` in the C API. 87 /// 88 /// C header: [`include/linux/init.h`](srctree/include/linux/init.h) 89 pub struct ThisModule(*mut bindings::module); 90 91 // SAFETY: `THIS_MODULE` may be used from all threads within a module. 92 unsafe impl Sync for ThisModule {} 93 94 impl ThisModule { 95 /// Creates a [`ThisModule`] given the `THIS_MODULE` pointer. 96 /// 97 /// # Safety 98 /// 99 /// The pointer must be equal to the right `THIS_MODULE`. 100 pub const unsafe fn from_ptr(ptr: *mut bindings::module) -> ThisModule { 101 ThisModule(ptr) 102 } 103 104 /// Access the raw pointer for this module. 105 /// 106 /// It is up to the user to use it correctly. 107 pub const fn as_ptr(&self) -> *mut bindings::module { 108 self.0 109 } 110 } 111 112 #[cfg(not(any(testlib, test)))] 113 #[panic_handler] 114 fn panic(info: &core::panic::PanicInfo<'_>) -> ! { 115 pr_emerg!("{}\n", info); 116 // SAFETY: FFI call. 117 unsafe { bindings::BUG() }; 118 } 119 120 /// Produces a pointer to an object from a pointer to one of its fields. 121 /// 122 /// # Safety 123 /// 124 /// The pointer passed to this macro, and the pointer returned by this macro, must both be in 125 /// bounds of the same allocation. 126 /// 127 /// # Examples 128 /// 129 /// ``` 130 /// # use kernel::container_of; 131 /// struct Test { 132 /// a: u64, 133 /// b: u32, 134 /// } 135 /// 136 /// let test = Test { a: 10, b: 20 }; 137 /// let b_ptr = &test.b; 138 /// // SAFETY: The pointer points at the `b` field of a `Test`, so the resulting pointer will be 139 /// // in-bounds of the same allocation as `b_ptr`. 140 /// let test_alias = unsafe { container_of!(b_ptr, Test, b) }; 141 /// assert!(core::ptr::eq(&test, test_alias)); 142 /// ``` 143 #[macro_export] 144 macro_rules! container_of { 145 ($ptr:expr, $type:ty, $($f:tt)*) => {{ 146 let ptr = $ptr as *const _ as *const u8; 147 let offset: usize = ::core::mem::offset_of!($type, $($f)*); 148 ptr.sub(offset) as *const $type 149 }} 150 } 151