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_RUST_FWCTL_ABSTRACTIONS)] 80 pub mod fwctl; 81 #[cfg(CONFIG_GPU_BUDDY = "y")] 82 pub mod gpu; 83 #[cfg(CONFIG_I2C = "y")] 84 pub mod i2c; 85 pub mod id_pool; 86 #[doc(hidden)] 87 pub mod impl_flags; 88 pub mod init; 89 pub mod interop; 90 pub mod interrupt; 91 pub mod io; 92 pub mod ioctl; 93 pub mod iommu; 94 pub mod iov; 95 pub mod irq; 96 pub mod jump_label; 97 #[cfg(CONFIG_KUNIT)] 98 pub mod kunit; 99 pub mod list; 100 pub mod maple_tree; 101 pub mod miscdevice; 102 pub mod mm; 103 pub mod module; 104 pub mod module_param; 105 #[cfg(CONFIG_NET)] 106 pub mod net; 107 pub mod num; 108 pub mod of; 109 #[cfg(CONFIG_PM_OPP)] 110 pub mod opp; 111 pub mod page; 112 #[cfg(CONFIG_PCI)] 113 pub mod pci; 114 pub mod pid_namespace; 115 pub mod platform; 116 pub mod prelude; 117 pub mod print; 118 pub mod processor; 119 pub mod ptr; 120 #[cfg(CONFIG_RUST_PWM_ABSTRACTIONS)] 121 pub mod pwm; 122 pub mod rbtree; 123 pub mod regulator; 124 pub mod revocable; 125 pub mod safety; 126 pub mod scatterlist; 127 pub mod security; 128 pub mod seq_file; 129 #[cfg(CONFIG_RUST_SERIAL_DEV_BUS_ABSTRACTIONS)] 130 pub mod serdev; 131 pub mod sizes; 132 #[cfg(CONFIG_SOC_BUS)] 133 pub mod soc; 134 #[doc(hidden)] 135 pub mod std_vendor; 136 pub mod str; 137 pub mod sync; 138 pub mod task; 139 pub mod time; 140 pub mod tracepoint; 141 pub mod transmute; 142 pub mod types; 143 pub mod uaccess; 144 #[cfg(CONFIG_USB = "y")] 145 pub mod usb; 146 pub mod workqueue; 147 pub mod xarray; 148 149 #[doc(hidden)] 150 pub use bindings; 151 pub use macros; 152 pub use module::{ 153 InPlaceModule, 154 Module, 155 ModuleMetadata, 156 ThisModule, // 157 }; 158 pub use uapi; 159 160 /// Prefix to appear before log messages printed from within the `kernel` crate. 161 const __LOG_PREFIX: &[u8] = b"rust_kernel\0"; 162 163 /// Dummy module type for `#[vtable]` `impl` blocks within the `kernel` crate (e.g. KUnit tests). 164 // The `allow` is needed since it may be unused (e.g. KUnit tests may be disabled). 165 #[allow(dead_code)] 166 struct LocalModule; 167 168 impl ModuleMetadata for LocalModule { 169 const NAME: &'static str::CStr = c"rust_kernel"; 170 171 const THIS_MODULE: ThisModule = { 172 // SAFETY: `try_module_get`/`module_put` handle null module pointers gracefully. 173 unsafe { ThisModule::from_ptr(core::ptr::null_mut()) } 174 }; 175 } 176 177 #[cfg(not(testlib))] 178 #[panic_handler] 179 fn panic(info: &core::panic::PanicInfo<'_>) -> ! { 180 pr_emerg!("{}\n", info); 181 // SAFETY: FFI call. 182 unsafe { bindings::BUG() }; 183 } 184 185 /// Produces a pointer to an object from a pointer to one of its fields. 186 /// 187 /// If you encounter a type mismatch due to the [`Opaque`] type, then use [`Opaque::cast_into`] or 188 /// [`Opaque::cast_from`] to resolve the mismatch. 189 /// 190 /// [`Opaque`]: crate::types::Opaque 191 /// [`Opaque::cast_into`]: crate::types::Opaque::cast_into 192 /// [`Opaque::cast_from`]: crate::types::Opaque::cast_from 193 /// 194 /// # Safety 195 /// 196 /// The pointer passed to this macro, and the pointer returned by this macro, must both be in 197 /// bounds of the same allocation. 198 /// 199 /// # Examples 200 /// 201 /// ``` 202 /// # use kernel::container_of; 203 /// struct Test { 204 /// a: u64, 205 /// b: u32, 206 /// } 207 /// 208 /// let test = Test { a: 10, b: 20 }; 209 /// let b_ptr: *const _ = &test.b; 210 /// // SAFETY: The pointer points at the `b` field of a `Test`, so the resulting pointer will be 211 /// // in-bounds of the same allocation as `b_ptr`. 212 /// let test_alias = unsafe { container_of!(b_ptr, Test, b) }; 213 /// assert!(core::ptr::eq(&test, test_alias)); 214 /// ``` 215 #[macro_export] 216 macro_rules! container_of { 217 ($field_ptr:expr, $Container:ty, $($fields:tt)*) => {{ 218 let offset: usize = ::core::mem::offset_of!($Container, $($fields)*); 219 let field_ptr = $field_ptr; 220 let container_ptr = field_ptr.byte_sub(offset).cast::<$Container>(); 221 $crate::assert_same_type(field_ptr, (&raw const (*container_ptr).$($fields)*).cast_mut()); 222 container_ptr 223 }} 224 } 225 226 /// Helper for [`container_of!`]. 227 #[doc(hidden)] 228 pub fn assert_same_type<T>(_: T, _: T) {} 229 230 /// Helper for `.rs.S` files. 231 #[doc(hidden)] 232 #[macro_export] 233 macro_rules! concat_literals { 234 ($( $asm:literal )* ) => { 235 ::core::concat!($($asm),*) 236 }; 237 } 238 239 /// Wrapper around `asm!` configured for use in the kernel. 240 /// 241 /// Uses a semicolon to avoid parsing ambiguities, even though this does not match native `asm!` 242 /// syntax. 243 // For x86, `asm!` uses intel syntax by default, but we want to use at&t syntax in the kernel. 244 #[cfg(any(target_arch = "x86", target_arch = "x86_64"))] 245 #[macro_export] 246 macro_rules! asm { 247 ($($asm:expr),* ; $($rest:tt)*) => { 248 ::core::arch::asm!( $($asm)*, options(att_syntax), $($rest)* ) 249 }; 250 } 251 252 /// Wrapper around `asm!` configured for use in the kernel. 253 /// 254 /// Uses a semicolon to avoid parsing ambiguities, even though this does not match native `asm!` 255 /// syntax. 256 // For non-x86 arches we just pass through to `asm!`. 257 #[cfg(not(any(target_arch = "x86", target_arch = "x86_64")))] 258 #[macro_export] 259 macro_rules! asm { 260 ($($asm:expr),* ; $($rest:tt)*) => { 261 ::core::arch::asm!( $($asm)*, $($rest)* ) 262 }; 263 } 264 265 /// Gets the C string file name of a [`Location`]. 266 /// 267 /// If `Location::file_as_c_str()` is not available, returns a string that warns about it. 268 /// 269 /// [`Location`]: core::panic::Location 270 /// 271 /// # Examples 272 /// 273 /// ``` 274 /// # use kernel::file_from_location; 275 /// 276 /// #[track_caller] 277 /// fn foo() { 278 /// let caller = core::panic::Location::caller(); 279 /// 280 /// // Output: 281 /// // - A path like "rust/kernel/example.rs" if `file_as_c_str()` is available. 282 /// // - "<Location::file_as_c_str() not supported>" otherwise. 283 /// let caller_file = file_from_location(caller); 284 /// 285 /// // Prints out the message with caller's file name. 286 /// pr_info!("foo() called in file {caller_file:?}\n"); 287 /// 288 /// # if cfg!(CONFIG_RUSTC_HAS_FILE_WITH_NUL) { 289 /// # assert_eq!(Ok(caller.file()), caller_file.to_str()); 290 /// # } 291 /// } 292 /// 293 /// # foo(); 294 /// ``` 295 #[inline] 296 pub fn file_from_location<'a>(loc: &'a core::panic::Location<'a>) -> &'a core::ffi::CStr { 297 #[cfg(CONFIG_RUSTC_HAS_FILE_AS_C_STR)] 298 { 299 loc.file_as_c_str() 300 } 301 302 #[cfg(all(CONFIG_RUSTC_HAS_FILE_WITH_NUL, not(CONFIG_RUSTC_HAS_FILE_AS_C_STR)))] 303 { 304 loc.file_with_nul() 305 } 306 307 #[cfg(not(CONFIG_RUSTC_HAS_FILE_WITH_NUL))] 308 { 309 let _ = loc; 310 c"<Location::file_as_c_str() not supported>" 311 } 312 } 313