1 // SPDX-License-Identifier: GPL-2.0 2 3 //! Crate for all kernel procedural macros. 4 5 #[macro_use] 6 mod quote; 7 mod concat_idents; 8 mod helpers; 9 mod module; 10 mod paste; 11 mod pin_data; 12 mod pinned_drop; 13 mod vtable; 14 mod zeroable; 15 16 use proc_macro::TokenStream; 17 18 /// Declares a kernel module. 19 /// 20 /// The `type` argument should be a type which implements the [`Module`] 21 /// trait. Also accepts various forms of kernel metadata. 22 /// 23 /// C header: [`include/linux/moduleparam.h`](../../../include/linux/moduleparam.h) 24 /// 25 /// [`Module`]: ../kernel/trait.Module.html 26 /// 27 /// # Examples 28 /// 29 /// ```ignore 30 /// use kernel::prelude::*; 31 /// 32 /// module!{ 33 /// type: MyModule, 34 /// name: "my_kernel_module", 35 /// author: "Rust for Linux Contributors", 36 /// description: "My very own kernel module!", 37 /// license: "GPL", 38 /// } 39 /// 40 /// struct MyModule; 41 /// 42 /// impl kernel::Module for MyModule { 43 /// fn init() -> Result<Self> { 44 /// // If the parameter is writeable, then the kparam lock must be 45 /// // taken to read the parameter: 46 /// { 47 /// let lock = THIS_MODULE.kernel_param_lock(); 48 /// pr_info!("i32 param is: {}\n", writeable_i32.read(&lock)); 49 /// } 50 /// // If the parameter is read only, it can be read without locking 51 /// // the kernel parameters: 52 /// pr_info!("i32 param is: {}\n", my_i32.read()); 53 /// Ok(Self) 54 /// } 55 /// } 56 /// ``` 57 /// 58 /// # Supported argument types 59 /// - `type`: type which implements the [`Module`] trait (required). 60 /// - `name`: byte array of the name of the kernel module (required). 61 /// - `author`: byte array of the author of the kernel module. 62 /// - `description`: byte array of the description of the kernel module. 63 /// - `license`: byte array of the license of the kernel module (required). 64 /// - `alias`: byte array of alias name of the kernel module. 65 #[proc_macro] 66 pub fn module(ts: TokenStream) -> TokenStream { 67 module::module(ts) 68 } 69 70 /// Declares or implements a vtable trait. 71 /// 72 /// Linux's use of pure vtables is very close to Rust traits, but they differ 73 /// in how unimplemented functions are represented. In Rust, traits can provide 74 /// default implementation for all non-required methods (and the default 75 /// implementation could just return `Error::EINVAL`); Linux typically use C 76 /// `NULL` pointers to represent these functions. 77 /// 78 /// This attribute is intended to close the gap. Traits can be declared and 79 /// implemented with the `#[vtable]` attribute, and a `HAS_*` associated constant 80 /// will be generated for each method in the trait, indicating if the implementor 81 /// has overridden a method. 82 /// 83 /// This attribute is not needed if all methods are required. 84 /// 85 /// # Examples 86 /// 87 /// ```ignore 88 /// use kernel::prelude::*; 89 /// 90 /// // Declares a `#[vtable]` trait 91 /// #[vtable] 92 /// pub trait Operations: Send + Sync + Sized { 93 /// fn foo(&self) -> Result<()> { 94 /// Err(EINVAL) 95 /// } 96 /// 97 /// fn bar(&self) -> Result<()> { 98 /// Err(EINVAL) 99 /// } 100 /// } 101 /// 102 /// struct Foo; 103 /// 104 /// // Implements the `#[vtable]` trait 105 /// #[vtable] 106 /// impl Operations for Foo { 107 /// fn foo(&self) -> Result<()> { 108 /// # Err(EINVAL) 109 /// // ... 110 /// } 111 /// } 112 /// 113 /// assert_eq!(<Foo as Operations>::HAS_FOO, true); 114 /// assert_eq!(<Foo as Operations>::HAS_BAR, false); 115 /// ``` 116 #[proc_macro_attribute] 117 pub fn vtable(attr: TokenStream, ts: TokenStream) -> TokenStream { 118 vtable::vtable(attr, ts) 119 } 120 121 /// Concatenate two identifiers. 122 /// 123 /// This is useful in macros that need to declare or reference items with names 124 /// starting with a fixed prefix and ending in a user specified name. The resulting 125 /// identifier has the span of the second argument. 126 /// 127 /// # Examples 128 /// 129 /// ```ignore 130 /// use kernel::macro::concat_idents; 131 /// 132 /// macro_rules! pub_no_prefix { 133 /// ($prefix:ident, $($newname:ident),+) => { 134 /// $(pub(crate) const $newname: u32 = kernel::macros::concat_idents!($prefix, $newname);)+ 135 /// }; 136 /// } 137 /// 138 /// pub_no_prefix!( 139 /// binder_driver_return_protocol_, 140 /// BR_OK, 141 /// BR_ERROR, 142 /// BR_TRANSACTION, 143 /// BR_REPLY, 144 /// BR_DEAD_REPLY, 145 /// BR_TRANSACTION_COMPLETE, 146 /// BR_INCREFS, 147 /// BR_ACQUIRE, 148 /// BR_RELEASE, 149 /// BR_DECREFS, 150 /// BR_NOOP, 151 /// BR_SPAWN_LOOPER, 152 /// BR_DEAD_BINDER, 153 /// BR_CLEAR_DEATH_NOTIFICATION_DONE, 154 /// BR_FAILED_REPLY 155 /// ); 156 /// 157 /// assert_eq!(BR_OK, binder_driver_return_protocol_BR_OK); 158 /// ``` 159 #[proc_macro] 160 pub fn concat_idents(ts: TokenStream) -> TokenStream { 161 concat_idents::concat_idents(ts) 162 } 163 164 /// Used to specify the pinning information of the fields of a struct. 165 /// 166 /// This is somewhat similar in purpose as 167 /// [pin-project-lite](https://crates.io/crates/pin-project-lite). 168 /// Place this macro on a struct definition and then `#[pin]` in front of the attributes of each 169 /// field you want to structurally pin. 170 /// 171 /// This macro enables the use of the [`pin_init!`] macro. When pin-initializing a `struct`, 172 /// then `#[pin]` directs the type of initializer that is required. 173 /// 174 /// If your `struct` implements `Drop`, then you need to add `PinnedDrop` as arguments to this 175 /// macro, and change your `Drop` implementation to `PinnedDrop` annotated with 176 /// `#[`[`macro@pinned_drop`]`]`, since dropping pinned values requires extra care. 177 /// 178 /// # Examples 179 /// 180 /// ```rust,ignore 181 /// #[pin_data] 182 /// struct DriverData { 183 /// #[pin] 184 /// queue: Mutex<Vec<Command>>, 185 /// buf: Box<[u8; 1024 * 1024]>, 186 /// } 187 /// ``` 188 /// 189 /// ```rust,ignore 190 /// #[pin_data(PinnedDrop)] 191 /// struct DriverData { 192 /// #[pin] 193 /// queue: Mutex<Vec<Command>>, 194 /// buf: Box<[u8; 1024 * 1024]>, 195 /// raw_info: *mut Info, 196 /// } 197 /// 198 /// #[pinned_drop] 199 /// impl PinnedDrop for DriverData { 200 /// fn drop(self: Pin<&mut Self>) { 201 /// unsafe { bindings::destroy_info(self.raw_info) }; 202 /// } 203 /// } 204 /// ``` 205 /// 206 /// [`pin_init!`]: ../kernel/macro.pin_init.html 207 // ^ cannot use direct link, since `kernel` is not a dependency of `macros`. 208 #[proc_macro_attribute] 209 pub fn pin_data(inner: TokenStream, item: TokenStream) -> TokenStream { 210 pin_data::pin_data(inner, item) 211 } 212 213 /// Used to implement `PinnedDrop` safely. 214 /// 215 /// Only works on structs that are annotated via `#[`[`macro@pin_data`]`]`. 216 /// 217 /// # Examples 218 /// 219 /// ```rust,ignore 220 /// #[pin_data(PinnedDrop)] 221 /// struct DriverData { 222 /// #[pin] 223 /// queue: Mutex<Vec<Command>>, 224 /// buf: Box<[u8; 1024 * 1024]>, 225 /// raw_info: *mut Info, 226 /// } 227 /// 228 /// #[pinned_drop] 229 /// impl PinnedDrop for DriverData { 230 /// fn drop(self: Pin<&mut Self>) { 231 /// unsafe { bindings::destroy_info(self.raw_info) }; 232 /// } 233 /// } 234 /// ``` 235 #[proc_macro_attribute] 236 pub fn pinned_drop(args: TokenStream, input: TokenStream) -> TokenStream { 237 pinned_drop::pinned_drop(args, input) 238 } 239 240 /// Paste identifiers together. 241 /// 242 /// Within the `paste!` macro, identifiers inside `[<` and `>]` are concatenated together to form a 243 /// single identifier. 244 /// 245 /// This is similar to the [`paste`] crate, but with pasting feature limited to identifiers 246 /// (literals, lifetimes and documentation strings are not supported). There is a difference in 247 /// supported modifiers as well. 248 /// 249 /// # Example 250 /// 251 /// ```ignore 252 /// use kernel::macro::paste; 253 /// 254 /// macro_rules! pub_no_prefix { 255 /// ($prefix:ident, $($newname:ident),+) => { 256 /// paste! { 257 /// $(pub(crate) const $newname: u32 = [<$prefix $newname>];)+ 258 /// } 259 /// }; 260 /// } 261 /// 262 /// pub_no_prefix!( 263 /// binder_driver_return_protocol_, 264 /// BR_OK, 265 /// BR_ERROR, 266 /// BR_TRANSACTION, 267 /// BR_REPLY, 268 /// BR_DEAD_REPLY, 269 /// BR_TRANSACTION_COMPLETE, 270 /// BR_INCREFS, 271 /// BR_ACQUIRE, 272 /// BR_RELEASE, 273 /// BR_DECREFS, 274 /// BR_NOOP, 275 /// BR_SPAWN_LOOPER, 276 /// BR_DEAD_BINDER, 277 /// BR_CLEAR_DEATH_NOTIFICATION_DONE, 278 /// BR_FAILED_REPLY 279 /// ); 280 /// 281 /// assert_eq!(BR_OK, binder_driver_return_protocol_BR_OK); 282 /// ``` 283 /// 284 /// # Modifiers 285 /// 286 /// For each identifier, it is possible to attach one or multiple modifiers to 287 /// it. 288 /// 289 /// Currently supported modifiers are: 290 /// * `span`: change the span of concatenated identifier to the span of the specified token. By 291 /// default the span of the `[< >]` group is used. 292 /// * `lower`: change the identifier to lower case. 293 /// * `upper`: change the identifier to upper case. 294 /// 295 /// ```ignore 296 /// use kernel::macro::paste; 297 /// 298 /// macro_rules! pub_no_prefix { 299 /// ($prefix:ident, $($newname:ident),+) => { 300 /// kernel::macros::paste! { 301 /// $(pub(crate) const fn [<$newname:lower:span>]: u32 = [<$prefix $newname:span>];)+ 302 /// } 303 /// }; 304 /// } 305 /// 306 /// pub_no_prefix!( 307 /// binder_driver_return_protocol_, 308 /// BR_OK, 309 /// BR_ERROR, 310 /// BR_TRANSACTION, 311 /// BR_REPLY, 312 /// BR_DEAD_REPLY, 313 /// BR_TRANSACTION_COMPLETE, 314 /// BR_INCREFS, 315 /// BR_ACQUIRE, 316 /// BR_RELEASE, 317 /// BR_DECREFS, 318 /// BR_NOOP, 319 /// BR_SPAWN_LOOPER, 320 /// BR_DEAD_BINDER, 321 /// BR_CLEAR_DEATH_NOTIFICATION_DONE, 322 /// BR_FAILED_REPLY 323 /// ); 324 /// 325 /// assert_eq!(br_ok(), binder_driver_return_protocol_BR_OK); 326 /// ``` 327 /// 328 /// [`paste`]: https://docs.rs/paste/ 329 #[proc_macro] 330 pub fn paste(input: TokenStream) -> TokenStream { 331 let mut tokens = input.into_iter().collect(); 332 paste::expand(&mut tokens); 333 tokens.into_iter().collect() 334 } 335 336 /// Derives the [`Zeroable`] trait for the given struct. 337 /// 338 /// This can only be used for structs where every field implements the [`Zeroable`] trait. 339 /// 340 /// # Examples 341 /// 342 /// ```rust,ignore 343 /// #[derive(Zeroable)] 344 /// pub struct DriverData { 345 /// id: i64, 346 /// buf_ptr: *mut u8, 347 /// len: usize, 348 /// } 349 /// ``` 350 #[proc_macro_derive(Zeroable)] 351 pub fn derive_zeroable(input: TokenStream) -> TokenStream { 352 zeroable::derive(input) 353 } 354