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