1 // SPDX-License-Identifier: GPL-2.0 2 3 //! Crate for all kernel procedural macros. 4 5 // When fixdep scans this, it will find this string `CONFIG_RUSTC_VERSION_TEXT` 6 // and thus add a dependency on `include/config/RUSTC_VERSION_TEXT`, which is 7 // touched by Kconfig when the version string from the compiler changes. 8 9 #[macro_use] 10 mod quote; 11 mod concat_idents; 12 mod export; 13 mod helpers; 14 mod module; 15 mod paste; 16 #[path = "../pin-init/internal/src/pin_data.rs"] 17 mod pin_data; 18 #[path = "../pin-init/internal/src/pinned_drop.rs"] 19 mod pinned_drop; 20 mod vtable; 21 #[path = "../pin-init/internal/src/zeroable.rs"] 22 mod zeroable; 23 24 use proc_macro::TokenStream; 25 26 /// Declares a kernel module. 27 /// 28 /// The `type` argument should be a type which implements the [`Module`] 29 /// trait. Also accepts various forms of kernel metadata. 30 /// 31 /// C header: [`include/linux/moduleparam.h`](srctree/include/linux/moduleparam.h) 32 /// 33 /// [`Module`]: ../kernel/trait.Module.html 34 /// 35 /// # Examples 36 /// 37 /// ``` 38 /// use kernel::prelude::*; 39 /// 40 /// module!{ 41 /// type: MyModule, 42 /// name: "my_kernel_module", 43 /// authors: ["Rust for Linux Contributors"], 44 /// description: "My very own kernel module!", 45 /// license: "GPL", 46 /// alias: ["alternate_module_name"], 47 /// } 48 /// 49 /// struct MyModule(i32); 50 /// 51 /// impl kernel::Module for MyModule { 52 /// fn init(_module: &'static ThisModule) -> Result<Self> { 53 /// let foo: i32 = 42; 54 /// pr_info!("I contain: {}\n", foo); 55 /// Ok(Self(foo)) 56 /// } 57 /// } 58 /// # fn main() {} 59 /// ``` 60 /// 61 /// ## Firmware 62 /// 63 /// The following example shows how to declare a kernel module that needs 64 /// to load binary firmware files. You need to specify the file names of 65 /// the firmware in the `firmware` field. The information is embedded 66 /// in the `modinfo` section of the kernel module. For example, a tool to 67 /// build an initramfs uses this information to put the firmware files into 68 /// the initramfs image. 69 /// 70 /// ``` 71 /// use kernel::prelude::*; 72 /// 73 /// module!{ 74 /// type: MyDeviceDriverModule, 75 /// name: "my_device_driver_module", 76 /// authors: ["Rust for Linux Contributors"], 77 /// description: "My device driver requires firmware", 78 /// license: "GPL", 79 /// firmware: ["my_device_firmware1.bin", "my_device_firmware2.bin"], 80 /// } 81 /// 82 /// struct MyDeviceDriverModule; 83 /// 84 /// impl kernel::Module for MyDeviceDriverModule { 85 /// fn init(_module: &'static ThisModule) -> Result<Self> { 86 /// Ok(Self) 87 /// } 88 /// } 89 /// # fn main() {} 90 /// ``` 91 /// 92 /// # Supported argument types 93 /// - `type`: type which implements the [`Module`] trait (required). 94 /// - `name`: ASCII string literal of the name of the kernel module (required). 95 /// - `authors`: array of ASCII string literals of the authors of the kernel module. 96 /// - `description`: string literal of the description of the kernel module. 97 /// - `license`: ASCII string literal of the license of the kernel module (required). 98 /// - `alias`: array of ASCII string literals of the alias names of the kernel module. 99 /// - `firmware`: array of ASCII string literals of the firmware files of 100 /// the kernel module. 101 #[proc_macro] 102 pub fn module(ts: TokenStream) -> TokenStream { 103 module::module(ts) 104 } 105 106 /// Declares or implements a vtable trait. 107 /// 108 /// Linux's use of pure vtables is very close to Rust traits, but they differ 109 /// in how unimplemented functions are represented. In Rust, traits can provide 110 /// default implementation for all non-required methods (and the default 111 /// implementation could just return `Error::EINVAL`); Linux typically use C 112 /// `NULL` pointers to represent these functions. 113 /// 114 /// This attribute closes that gap. A trait can be annotated with the 115 /// `#[vtable]` attribute. Implementers of the trait will then also have to 116 /// annotate the trait with `#[vtable]`. This attribute generates a `HAS_*` 117 /// associated constant bool for each method in the trait that is set to true if 118 /// the implementer has overridden the associated method. 119 /// 120 /// For a trait method to be optional, it must have a default implementation. 121 /// This is also the case for traits annotated with `#[vtable]`, but in this 122 /// case the default implementation will never be executed. The reason for this 123 /// is that the functions will be called through function pointers installed in 124 /// C side vtables. When an optional method is not implemented on a `#[vtable]` 125 /// trait, a NULL entry is installed in the vtable. Thus the default 126 /// implementation is never called. Since these traits are not designed to be 127 /// used on the Rust side, it should not be possible to call the default 128 /// implementation. This is done to ensure that we call the vtable methods 129 /// through the C vtable, and not through the Rust vtable. Therefore, the 130 /// default implementation should call `build_error!`, which prevents 131 /// calls to this function at compile time: 132 /// 133 /// ```compile_fail 134 /// # // Intentionally missing `use`s to simplify `rusttest`. 135 /// build_error!(VTABLE_DEFAULT_ERROR) 136 /// ``` 137 /// 138 /// Note that you might need to import [`kernel::error::VTABLE_DEFAULT_ERROR`]. 139 /// 140 /// This macro should not be used when all functions are required. 141 /// 142 /// # Examples 143 /// 144 /// ``` 145 /// use kernel::error::VTABLE_DEFAULT_ERROR; 146 /// use kernel::prelude::*; 147 /// 148 /// // Declares a `#[vtable]` trait 149 /// #[vtable] 150 /// pub trait Operations: Send + Sync + Sized { 151 /// fn foo(&self) -> Result<()> { 152 /// build_error!(VTABLE_DEFAULT_ERROR) 153 /// } 154 /// 155 /// fn bar(&self) -> Result<()> { 156 /// build_error!(VTABLE_DEFAULT_ERROR) 157 /// } 158 /// } 159 /// 160 /// struct Foo; 161 /// 162 /// // Implements the `#[vtable]` trait 163 /// #[vtable] 164 /// impl Operations for Foo { 165 /// fn foo(&self) -> Result<()> { 166 /// # Err(EINVAL) 167 /// // ... 168 /// } 169 /// } 170 /// 171 /// assert_eq!(<Foo as Operations>::HAS_FOO, true); 172 /// assert_eq!(<Foo as Operations>::HAS_BAR, false); 173 /// ``` 174 /// 175 /// [`kernel::error::VTABLE_DEFAULT_ERROR`]: ../kernel/error/constant.VTABLE_DEFAULT_ERROR.html 176 #[proc_macro_attribute] 177 pub fn vtable(attr: TokenStream, ts: TokenStream) -> TokenStream { 178 vtable::vtable(attr, ts) 179 } 180 181 /// Export a function so that C code can call it via a header file. 182 /// 183 /// Functions exported using this macro can be called from C code using the declaration in the 184 /// appropriate header file. It should only be used in cases where C calls the function through a 185 /// header file; cases where C calls into Rust via a function pointer in a vtable (such as 186 /// `file_operations`) should not use this macro. 187 /// 188 /// This macro has the following effect: 189 /// 190 /// * Disables name mangling for this function. 191 /// * Verifies at compile-time that the function signature matches the declaration in the header 192 /// file. 193 /// 194 /// You must declare the signature of the Rust function in a header file that is included by 195 /// `rust/bindings/bindings_helper.h`. 196 /// 197 /// This macro is *not* the same as the C macros `EXPORT_SYMBOL_*`. All Rust symbols are currently 198 /// automatically exported with `EXPORT_SYMBOL_GPL`. 199 #[proc_macro_attribute] 200 pub fn export(attr: TokenStream, ts: TokenStream) -> TokenStream { 201 export::export(attr, ts) 202 } 203 204 /// Concatenate two identifiers. 205 /// 206 /// This is useful in macros that need to declare or reference items with names 207 /// starting with a fixed prefix and ending in a user specified name. The resulting 208 /// identifier has the span of the second argument. 209 /// 210 /// # Examples 211 /// 212 /// ``` 213 /// # const binder_driver_return_protocol_BR_OK: u32 = 0; 214 /// # const binder_driver_return_protocol_BR_ERROR: u32 = 1; 215 /// # const binder_driver_return_protocol_BR_TRANSACTION: u32 = 2; 216 /// # const binder_driver_return_protocol_BR_REPLY: u32 = 3; 217 /// # const binder_driver_return_protocol_BR_DEAD_REPLY: u32 = 4; 218 /// # const binder_driver_return_protocol_BR_TRANSACTION_COMPLETE: u32 = 5; 219 /// # const binder_driver_return_protocol_BR_INCREFS: u32 = 6; 220 /// # const binder_driver_return_protocol_BR_ACQUIRE: u32 = 7; 221 /// # const binder_driver_return_protocol_BR_RELEASE: u32 = 8; 222 /// # const binder_driver_return_protocol_BR_DECREFS: u32 = 9; 223 /// # const binder_driver_return_protocol_BR_NOOP: u32 = 10; 224 /// # const binder_driver_return_protocol_BR_SPAWN_LOOPER: u32 = 11; 225 /// # const binder_driver_return_protocol_BR_DEAD_BINDER: u32 = 12; 226 /// # const binder_driver_return_protocol_BR_CLEAR_DEATH_NOTIFICATION_DONE: u32 = 13; 227 /// # const binder_driver_return_protocol_BR_FAILED_REPLY: u32 = 14; 228 /// use kernel::macros::concat_idents; 229 /// 230 /// macro_rules! pub_no_prefix { 231 /// ($prefix:ident, $($newname:ident),+) => { 232 /// $(pub(crate) const $newname: u32 = concat_idents!($prefix, $newname);)+ 233 /// }; 234 /// } 235 /// 236 /// pub_no_prefix!( 237 /// binder_driver_return_protocol_, 238 /// BR_OK, 239 /// BR_ERROR, 240 /// BR_TRANSACTION, 241 /// BR_REPLY, 242 /// BR_DEAD_REPLY, 243 /// BR_TRANSACTION_COMPLETE, 244 /// BR_INCREFS, 245 /// BR_ACQUIRE, 246 /// BR_RELEASE, 247 /// BR_DECREFS, 248 /// BR_NOOP, 249 /// BR_SPAWN_LOOPER, 250 /// BR_DEAD_BINDER, 251 /// BR_CLEAR_DEATH_NOTIFICATION_DONE, 252 /// BR_FAILED_REPLY 253 /// ); 254 /// 255 /// assert_eq!(BR_OK, binder_driver_return_protocol_BR_OK); 256 /// ``` 257 #[proc_macro] 258 pub fn concat_idents(ts: TokenStream) -> TokenStream { 259 concat_idents::concat_idents(ts) 260 } 261 262 /// Paste identifiers together. 263 /// 264 /// Within the `paste!` macro, identifiers inside `[<` and `>]` are concatenated together to form a 265 /// single identifier. 266 /// 267 /// This is similar to the [`paste`] crate, but with pasting feature limited to identifiers and 268 /// literals (lifetimes and documentation strings are not supported). There is a difference in 269 /// supported modifiers as well. 270 /// 271 /// # Example 272 /// 273 /// ``` 274 /// # const binder_driver_return_protocol_BR_OK: u32 = 0; 275 /// # const binder_driver_return_protocol_BR_ERROR: u32 = 1; 276 /// # const binder_driver_return_protocol_BR_TRANSACTION: u32 = 2; 277 /// # const binder_driver_return_protocol_BR_REPLY: u32 = 3; 278 /// # const binder_driver_return_protocol_BR_DEAD_REPLY: u32 = 4; 279 /// # const binder_driver_return_protocol_BR_TRANSACTION_COMPLETE: u32 = 5; 280 /// # const binder_driver_return_protocol_BR_INCREFS: u32 = 6; 281 /// # const binder_driver_return_protocol_BR_ACQUIRE: u32 = 7; 282 /// # const binder_driver_return_protocol_BR_RELEASE: u32 = 8; 283 /// # const binder_driver_return_protocol_BR_DECREFS: u32 = 9; 284 /// # const binder_driver_return_protocol_BR_NOOP: u32 = 10; 285 /// # const binder_driver_return_protocol_BR_SPAWN_LOOPER: u32 = 11; 286 /// # const binder_driver_return_protocol_BR_DEAD_BINDER: u32 = 12; 287 /// # const binder_driver_return_protocol_BR_CLEAR_DEATH_NOTIFICATION_DONE: u32 = 13; 288 /// # const binder_driver_return_protocol_BR_FAILED_REPLY: u32 = 14; 289 /// macro_rules! pub_no_prefix { 290 /// ($prefix:ident, $($newname:ident),+) => { 291 /// kernel::macros::paste! { 292 /// $(pub(crate) const $newname: u32 = [<$prefix $newname>];)+ 293 /// } 294 /// }; 295 /// } 296 /// 297 /// pub_no_prefix!( 298 /// binder_driver_return_protocol_, 299 /// BR_OK, 300 /// BR_ERROR, 301 /// BR_TRANSACTION, 302 /// BR_REPLY, 303 /// BR_DEAD_REPLY, 304 /// BR_TRANSACTION_COMPLETE, 305 /// BR_INCREFS, 306 /// BR_ACQUIRE, 307 /// BR_RELEASE, 308 /// BR_DECREFS, 309 /// BR_NOOP, 310 /// BR_SPAWN_LOOPER, 311 /// BR_DEAD_BINDER, 312 /// BR_CLEAR_DEATH_NOTIFICATION_DONE, 313 /// BR_FAILED_REPLY 314 /// ); 315 /// 316 /// assert_eq!(BR_OK, binder_driver_return_protocol_BR_OK); 317 /// ``` 318 /// 319 /// # Modifiers 320 /// 321 /// For each identifier, it is possible to attach one or multiple modifiers to 322 /// it. 323 /// 324 /// Currently supported modifiers are: 325 /// * `span`: change the span of concatenated identifier to the span of the specified token. By 326 /// default the span of the `[< >]` group is used. 327 /// * `lower`: change the identifier to lower case. 328 /// * `upper`: change the identifier to upper case. 329 /// 330 /// ``` 331 /// # const binder_driver_return_protocol_BR_OK: u32 = 0; 332 /// # const binder_driver_return_protocol_BR_ERROR: u32 = 1; 333 /// # const binder_driver_return_protocol_BR_TRANSACTION: u32 = 2; 334 /// # const binder_driver_return_protocol_BR_REPLY: u32 = 3; 335 /// # const binder_driver_return_protocol_BR_DEAD_REPLY: u32 = 4; 336 /// # const binder_driver_return_protocol_BR_TRANSACTION_COMPLETE: u32 = 5; 337 /// # const binder_driver_return_protocol_BR_INCREFS: u32 = 6; 338 /// # const binder_driver_return_protocol_BR_ACQUIRE: u32 = 7; 339 /// # const binder_driver_return_protocol_BR_RELEASE: u32 = 8; 340 /// # const binder_driver_return_protocol_BR_DECREFS: u32 = 9; 341 /// # const binder_driver_return_protocol_BR_NOOP: u32 = 10; 342 /// # const binder_driver_return_protocol_BR_SPAWN_LOOPER: u32 = 11; 343 /// # const binder_driver_return_protocol_BR_DEAD_BINDER: u32 = 12; 344 /// # const binder_driver_return_protocol_BR_CLEAR_DEATH_NOTIFICATION_DONE: u32 = 13; 345 /// # const binder_driver_return_protocol_BR_FAILED_REPLY: u32 = 14; 346 /// macro_rules! pub_no_prefix { 347 /// ($prefix:ident, $($newname:ident),+) => { 348 /// kernel::macros::paste! { 349 /// $(pub(crate) const fn [<$newname:lower:span>]() -> u32 { [<$prefix $newname:span>] })+ 350 /// } 351 /// }; 352 /// } 353 /// 354 /// pub_no_prefix!( 355 /// binder_driver_return_protocol_, 356 /// BR_OK, 357 /// BR_ERROR, 358 /// BR_TRANSACTION, 359 /// BR_REPLY, 360 /// BR_DEAD_REPLY, 361 /// BR_TRANSACTION_COMPLETE, 362 /// BR_INCREFS, 363 /// BR_ACQUIRE, 364 /// BR_RELEASE, 365 /// BR_DECREFS, 366 /// BR_NOOP, 367 /// BR_SPAWN_LOOPER, 368 /// BR_DEAD_BINDER, 369 /// BR_CLEAR_DEATH_NOTIFICATION_DONE, 370 /// BR_FAILED_REPLY 371 /// ); 372 /// 373 /// assert_eq!(br_ok(), binder_driver_return_protocol_BR_OK); 374 /// ``` 375 /// 376 /// # Literals 377 /// 378 /// Literals can also be concatenated with other identifiers: 379 /// 380 /// ``` 381 /// macro_rules! create_numbered_fn { 382 /// ($name:literal, $val:literal) => { 383 /// kernel::macros::paste! { 384 /// fn [<some_ $name _fn $val>]() -> u32 { $val } 385 /// } 386 /// }; 387 /// } 388 /// 389 /// create_numbered_fn!("foo", 100); 390 /// 391 /// assert_eq!(some_foo_fn100(), 100) 392 /// ``` 393 /// 394 /// [`paste`]: https://docs.rs/paste/ 395 #[proc_macro] 396 pub fn paste(input: TokenStream) -> TokenStream { 397 let mut tokens = input.into_iter().collect(); 398 paste::expand(&mut tokens); 399 tokens.into_iter().collect() 400 } 401 402 include!("../pin-init/internal/src/lib.rs"); 403