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 seq_file; 52 pub mod sizes; 53 mod static_assert; 54 #[doc(hidden)] 55 pub mod std_vendor; 56 pub mod str; 57 pub mod sync; 58 pub mod task; 59 pub mod time; 60 pub mod types; 61 pub mod uaccess; 62 pub mod workqueue; 63 64 #[doc(hidden)] 65 pub use bindings; 66 pub use macros; 67 pub use uapi; 68 69 #[doc(hidden)] 70 pub use build_error::build_error; 71 72 /// Prefix to appear before log messages printed from within the `kernel` crate. 73 const __LOG_PREFIX: &[u8] = b"rust_kernel\0"; 74 75 /// The top level entrypoint to implementing a kernel module. 76 /// 77 /// For any teardown or cleanup operations, your type may implement [`Drop`]. 78 pub trait Module: Sized + Sync + Send { 79 /// Called at module initialization time. 80 /// 81 /// Use this method to perform whatever setup or registration your module 82 /// should do. 83 /// 84 /// Equivalent to the `module_init` macro in the C API. 85 fn init(module: &'static ThisModule) -> error::Result<Self>; 86 } 87 88 /// Equivalent to `THIS_MODULE` in the C API. 89 /// 90 /// C header: [`include/linux/export.h`](srctree/include/linux/export.h) 91 pub struct ThisModule(*mut bindings::module); 92 93 // SAFETY: `THIS_MODULE` may be used from all threads within a module. 94 unsafe impl Sync for ThisModule {} 95 96 impl ThisModule { 97 /// Creates a [`ThisModule`] given the `THIS_MODULE` pointer. 98 /// 99 /// # Safety 100 /// 101 /// The pointer must be equal to the right `THIS_MODULE`. 102 pub const unsafe fn from_ptr(ptr: *mut bindings::module) -> ThisModule { 103 ThisModule(ptr) 104 } 105 106 /// Access the raw pointer for this module. 107 /// 108 /// It is up to the user to use it correctly. 109 pub const fn as_ptr(&self) -> *mut bindings::module { 110 self.0 111 } 112 } 113 114 #[cfg(not(any(testlib, test)))] 115 #[panic_handler] 116 fn panic(info: &core::panic::PanicInfo<'_>) -> ! { 117 pr_emerg!("{}\n", info); 118 // SAFETY: FFI call. 119 unsafe { bindings::BUG() }; 120 } 121 122 /// Produces a pointer to an object from a pointer to one of its fields. 123 /// 124 /// # Safety 125 /// 126 /// The pointer passed to this macro, and the pointer returned by this macro, must both be in 127 /// bounds of the same allocation. 128 /// 129 /// # Examples 130 /// 131 /// ``` 132 /// # use kernel::container_of; 133 /// struct Test { 134 /// a: u64, 135 /// b: u32, 136 /// } 137 /// 138 /// let test = Test { a: 10, b: 20 }; 139 /// let b_ptr = &test.b; 140 /// // SAFETY: The pointer points at the `b` field of a `Test`, so the resulting pointer will be 141 /// // in-bounds of the same allocation as `b_ptr`. 142 /// let test_alias = unsafe { container_of!(b_ptr, Test, b) }; 143 /// assert!(core::ptr::eq(&test, test_alias)); 144 /// ``` 145 #[macro_export] 146 macro_rules! container_of { 147 ($ptr:expr, $type:ty, $($f:tt)*) => {{ 148 let ptr = $ptr as *const _ as *const u8; 149 let offset: usize = ::core::mem::offset_of!($type, $($f)*); 150 ptr.sub(offset) as *const $type 151 }} 152 } 153