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 cred; 34 pub mod device; 35 pub mod error; 36 #[cfg(CONFIG_RUST_FW_LOADER_ABSTRACTIONS)] 37 pub mod firmware; 38 pub mod fs; 39 pub mod init; 40 pub mod ioctl; 41 #[cfg(CONFIG_KUNIT)] 42 pub mod kunit; 43 pub mod list; 44 #[cfg(CONFIG_NET)] 45 pub mod net; 46 pub mod page; 47 pub mod prelude; 48 pub mod print; 49 pub mod rbtree; 50 pub mod security; 51 pub mod sizes; 52 mod static_assert; 53 #[doc(hidden)] 54 pub mod std_vendor; 55 pub mod str; 56 pub mod sync; 57 pub mod task; 58 pub mod time; 59 pub mod types; 60 pub mod uaccess; 61 pub mod workqueue; 62 63 #[doc(hidden)] 64 pub use bindings; 65 pub use macros; 66 pub use uapi; 67 68 #[doc(hidden)] 69 pub use build_error::build_error; 70 71 /// Prefix to appear before log messages printed from within the `kernel` crate. 72 const __LOG_PREFIX: &[u8] = b"rust_kernel\0"; 73 74 /// The top level entrypoint to implementing a kernel module. 75 /// 76 /// For any teardown or cleanup operations, your type may implement [`Drop`]. 77 pub trait Module: Sized + Sync + Send { 78 /// Called at module initialization time. 79 /// 80 /// Use this method to perform whatever setup or registration your module 81 /// should do. 82 /// 83 /// Equivalent to the `module_init` macro in the C API. 84 fn init(module: &'static ThisModule) -> error::Result<Self>; 85 } 86 87 /// Equivalent to `THIS_MODULE` in the C API. 88 /// 89 /// C header: [`include/linux/export.h`](srctree/include/linux/export.h) 90 pub struct ThisModule(*mut bindings::module); 91 92 // SAFETY: `THIS_MODULE` may be used from all threads within a module. 93 unsafe impl Sync for ThisModule {} 94 95 impl ThisModule { 96 /// Creates a [`ThisModule`] given the `THIS_MODULE` pointer. 97 /// 98 /// # Safety 99 /// 100 /// The pointer must be equal to the right `THIS_MODULE`. 101 pub const unsafe fn from_ptr(ptr: *mut bindings::module) -> ThisModule { 102 ThisModule(ptr) 103 } 104 105 /// Access the raw pointer for this module. 106 /// 107 /// It is up to the user to use it correctly. 108 pub const fn as_ptr(&self) -> *mut bindings::module { 109 self.0 110 } 111 } 112 113 #[cfg(not(any(testlib, test)))] 114 #[panic_handler] 115 fn panic(info: &core::panic::PanicInfo<'_>) -> ! { 116 pr_emerg!("{}\n", info); 117 // SAFETY: FFI call. 118 unsafe { bindings::BUG() }; 119 } 120 121 /// Produces a pointer to an object from a pointer to one of its fields. 122 /// 123 /// # Safety 124 /// 125 /// The pointer passed to this macro, and the pointer returned by this macro, must both be in 126 /// bounds of the same allocation. 127 /// 128 /// # Examples 129 /// 130 /// ``` 131 /// # use kernel::container_of; 132 /// struct Test { 133 /// a: u64, 134 /// b: u32, 135 /// } 136 /// 137 /// let test = Test { a: 10, b: 20 }; 138 /// let b_ptr = &test.b; 139 /// // SAFETY: The pointer points at the `b` field of a `Test`, so the resulting pointer will be 140 /// // in-bounds of the same allocation as `b_ptr`. 141 /// let test_alias = unsafe { container_of!(b_ptr, Test, b) }; 142 /// assert!(core::ptr::eq(&test, test_alias)); 143 /// ``` 144 #[macro_export] 145 macro_rules! container_of { 146 ($ptr:expr, $type:ty, $($f:tt)*) => {{ 147 let ptr = $ptr as *const _ as *const u8; 148 let offset: usize = ::core::mem::offset_of!($type, $($f)*); 149 ptr.sub(offset) as *const $type 150 }} 151 } 152