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`] 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 // 16 // Please see https://github.com/Rust-for-Linux/linux/issues/2 for details on 17 // the unstable features in use. 18 // 19 // Stable since Rust 1.87.0. 20 #![feature(unsigned_is_multiple_of)] 21 // 22 // Stable since Rust 1.89.0. 23 #![feature(generic_arg_infer)] 24 // 25 // Expected to become stable. 26 #![feature(arbitrary_self_types)] 27 #![feature(derive_coerce_pointee)] 28 // 29 // To be determined. 30 #![feature(used_with_arg)] 31 // 32 // `feature(file_with_nul)` is stable since Rust 1.92.0. Before Rust 1.89.0, it did not exist, so 33 // enable it conditionally. 34 #![cfg_attr(CONFIG_RUSTC_HAS_FILE_WITH_NUL, feature(file_with_nul))] 35 36 // Ensure conditional compilation based on the kernel configuration works; 37 // otherwise we may silently break things like initcall handling. 38 #[cfg(not(CONFIG_RUST))] 39 compile_error!("Missing kernel configuration for conditional compilation"); 40 41 // Allow proc-macros to refer to `::kernel` inside the `kernel` crate (this crate). 42 extern crate self as kernel; 43 44 pub use ffi; 45 46 pub mod acpi; 47 pub mod alloc; 48 #[cfg(CONFIG_AUXILIARY_BUS)] 49 pub mod auxiliary; 50 pub mod bitfield; 51 pub mod bitmap; 52 pub mod bits; 53 #[cfg(CONFIG_BLOCK)] 54 pub mod block; 55 pub mod bug; 56 pub mod build_assert; 57 pub mod clk; 58 #[cfg(CONFIG_CONFIGFS_FS)] 59 pub mod configfs; 60 pub mod cpu; 61 #[cfg(CONFIG_CPU_FREQ)] 62 pub mod cpufreq; 63 pub mod cpumask; 64 pub mod cred; 65 pub mod debugfs; 66 pub mod device; 67 pub mod device_id; 68 pub mod devres; 69 pub mod dma; 70 pub mod driver; 71 #[cfg(CONFIG_DRM = "y")] 72 pub mod drm; 73 pub mod error; 74 pub mod faux; 75 #[cfg(CONFIG_RUST_FW_LOADER_ABSTRACTIONS)] 76 pub mod firmware; 77 pub mod fmt; 78 pub mod fs; 79 #[cfg(CONFIG_GPU_BUDDY = "y")] 80 pub mod gpu; 81 #[cfg(CONFIG_I2C = "y")] 82 pub mod i2c; 83 pub mod id_pool; 84 #[doc(hidden)] 85 pub mod impl_flags; 86 pub mod init; 87 pub mod interop; 88 pub mod interrupt; 89 pub mod io; 90 pub mod ioctl; 91 pub mod iommu; 92 pub mod iov; 93 pub mod irq; 94 pub mod jump_label; 95 #[cfg(CONFIG_KUNIT)] 96 pub mod kunit; 97 pub mod list; 98 pub mod maple_tree; 99 pub mod miscdevice; 100 pub mod mm; 101 pub mod module; 102 pub mod module_param; 103 #[cfg(CONFIG_NET)] 104 pub mod net; 105 pub mod num; 106 pub mod of; 107 #[cfg(CONFIG_PM_OPP)] 108 pub mod opp; 109 pub mod page; 110 #[cfg(CONFIG_PCI)] 111 pub mod pci; 112 pub mod pid_namespace; 113 pub mod platform; 114 pub mod prelude; 115 pub mod print; 116 pub mod processor; 117 pub mod ptr; 118 #[cfg(CONFIG_RUST_PWM_ABSTRACTIONS)] 119 pub mod pwm; 120 pub mod rbtree; 121 pub mod regulator; 122 pub mod revocable; 123 pub mod safety; 124 pub mod scatterlist; 125 pub mod security; 126 pub mod seq_file; 127 #[cfg(CONFIG_RUST_SERIAL_DEV_BUS_ABSTRACTIONS)] 128 pub mod serdev; 129 pub mod sizes; 130 #[cfg(CONFIG_SOC_BUS)] 131 pub mod soc; 132 #[doc(hidden)] 133 pub mod std_vendor; 134 pub mod str; 135 pub mod sync; 136 pub mod task; 137 pub mod time; 138 pub mod tracepoint; 139 pub mod transmute; 140 pub mod types; 141 pub mod uaccess; 142 #[cfg(CONFIG_USB = "y")] 143 pub mod usb; 144 pub mod workqueue; 145 pub mod xarray; 146 147 #[doc(hidden)] 148 pub use bindings; 149 pub use macros; 150 pub use module::{ 151 InPlaceModule, 152 Module, 153 ModuleMetadata, 154 ThisModule, // 155 }; 156 pub use uapi; 157 158 /// Prefix to appear before log messages printed from within the `kernel` crate. 159 const __LOG_PREFIX: &[u8] = b"rust_kernel\0"; 160 161 /// Dummy module type for `#[vtable]` `impl` blocks within the `kernel` crate (e.g. KUnit tests). 162 // The `allow` is needed since it may be unused (e.g. KUnit tests may be disabled). 163 #[allow(dead_code)] 164 struct LocalModule; 165 166 impl ModuleMetadata for LocalModule { 167 const NAME: &'static str::CStr = c"rust_kernel"; 168 169 const THIS_MODULE: ThisModule = { 170 // SAFETY: `try_module_get`/`module_put` handle null module pointers gracefully. 171 unsafe { ThisModule::from_ptr(core::ptr::null_mut()) } 172 }; 173 } 174 175 #[cfg(not(testlib))] 176 #[panic_handler] 177 fn panic(info: &core::panic::PanicInfo<'_>) -> ! { 178 pr_emerg!("{}\n", info); 179 // SAFETY: FFI call. 180 unsafe { bindings::BUG() }; 181 } 182 183 /// Produces a pointer to an object from a pointer to one of its fields. 184 /// 185 /// If you encounter a type mismatch due to the [`Opaque`] type, then use [`Opaque::cast_into`] or 186 /// [`Opaque::cast_from`] to resolve the mismatch. 187 /// 188 /// [`Opaque`]: crate::types::Opaque 189 /// [`Opaque::cast_into`]: crate::types::Opaque::cast_into 190 /// [`Opaque::cast_from`]: crate::types::Opaque::cast_from 191 /// 192 /// # Safety 193 /// 194 /// The pointer passed to this macro, and the pointer returned by this macro, must both be in 195 /// bounds of the same allocation. 196 /// 197 /// # Examples 198 /// 199 /// ``` 200 /// # use kernel::container_of; 201 /// struct Test { 202 /// a: u64, 203 /// b: u32, 204 /// } 205 /// 206 /// let test = Test { a: 10, b: 20 }; 207 /// let b_ptr: *const _ = &test.b; 208 /// // SAFETY: The pointer points at the `b` field of a `Test`, so the resulting pointer will be 209 /// // in-bounds of the same allocation as `b_ptr`. 210 /// let test_alias = unsafe { container_of!(b_ptr, Test, b) }; 211 /// assert!(core::ptr::eq(&test, test_alias)); 212 /// ``` 213 #[macro_export] 214 macro_rules! container_of { 215 ($field_ptr:expr, $Container:ty, $($fields:tt)*) => {{ 216 let offset: usize = ::core::mem::offset_of!($Container, $($fields)*); 217 let field_ptr = $field_ptr; 218 let container_ptr = field_ptr.byte_sub(offset).cast::<$Container>(); 219 $crate::assert_same_type(field_ptr, (&raw const (*container_ptr).$($fields)*).cast_mut()); 220 container_ptr 221 }} 222 } 223 224 /// Helper for [`container_of!`]. 225 #[doc(hidden)] 226 pub fn assert_same_type<T>(_: T, _: T) {} 227 228 /// Helper for `.rs.S` files. 229 #[doc(hidden)] 230 #[macro_export] 231 macro_rules! concat_literals { 232 ($( $asm:literal )* ) => { 233 ::core::concat!($($asm),*) 234 }; 235 } 236 237 /// Wrapper around `asm!` configured for use in the kernel. 238 /// 239 /// Uses a semicolon to avoid parsing ambiguities, even though this does not match native `asm!` 240 /// syntax. 241 // For x86, `asm!` uses intel syntax by default, but we want to use at&t syntax in the kernel. 242 #[cfg(any(target_arch = "x86", target_arch = "x86_64"))] 243 #[macro_export] 244 macro_rules! asm { 245 ($($asm:expr),* ; $($rest:tt)*) => { 246 ::core::arch::asm!( $($asm)*, options(att_syntax), $($rest)* ) 247 }; 248 } 249 250 /// Wrapper around `asm!` configured for use in the kernel. 251 /// 252 /// Uses a semicolon to avoid parsing ambiguities, even though this does not match native `asm!` 253 /// syntax. 254 // For non-x86 arches we just pass through to `asm!`. 255 #[cfg(not(any(target_arch = "x86", target_arch = "x86_64")))] 256 #[macro_export] 257 macro_rules! asm { 258 ($($asm:expr),* ; $($rest:tt)*) => { 259 ::core::arch::asm!( $($asm)*, $($rest)* ) 260 }; 261 } 262 263 /// Gets the C string file name of a [`Location`]. 264 /// 265 /// If `Location::file_as_c_str()` is not available, returns a string that warns about it. 266 /// 267 /// [`Location`]: core::panic::Location 268 /// 269 /// # Examples 270 /// 271 /// ``` 272 /// # use kernel::file_from_location; 273 /// 274 /// #[track_caller] 275 /// fn foo() { 276 /// let caller = core::panic::Location::caller(); 277 /// 278 /// // Output: 279 /// // - A path like "rust/kernel/example.rs" if `file_as_c_str()` is available. 280 /// // - "<Location::file_as_c_str() not supported>" otherwise. 281 /// let caller_file = file_from_location(caller); 282 /// 283 /// // Prints out the message with caller's file name. 284 /// pr_info!("foo() called in file {caller_file:?}\n"); 285 /// 286 /// # if cfg!(CONFIG_RUSTC_HAS_FILE_WITH_NUL) { 287 /// # assert_eq!(Ok(caller.file()), caller_file.to_str()); 288 /// # } 289 /// } 290 /// 291 /// # foo(); 292 /// ``` 293 #[inline] 294 pub fn file_from_location<'a>(loc: &'a core::panic::Location<'a>) -> &'a core::ffi::CStr { 295 #[cfg(CONFIG_RUSTC_HAS_FILE_AS_C_STR)] 296 { 297 loc.file_as_c_str() 298 } 299 300 #[cfg(all(CONFIG_RUSTC_HAS_FILE_WITH_NUL, not(CONFIG_RUSTC_HAS_FILE_AS_C_STR)))] 301 { 302 loc.file_with_nul() 303 } 304 305 #[cfg(not(CONFIG_RUSTC_HAS_FILE_WITH_NUL))] 306 { 307 let _ = loc; 308 c"<Location::file_as_c_str() not supported>" 309 } 310 } 311