1 // SPDX-License-Identifier: GPL-2.0 2 3 use crate::helpers::*; 4 use proc_macro::{token_stream, Delimiter, Literal, TokenStream, TokenTree}; 5 use std::fmt::Write; 6 7 fn expect_string_array(it: &mut token_stream::IntoIter) -> Vec<String> { 8 let group = expect_group(it); 9 assert_eq!(group.delimiter(), Delimiter::Bracket); 10 let mut values = Vec::new(); 11 let mut it = group.stream().into_iter(); 12 13 while let Some(val) = try_string(&mut it) { 14 assert!(val.is_ascii(), "Expected ASCII string"); 15 values.push(val); 16 match it.next() { 17 Some(TokenTree::Punct(punct)) => assert_eq!(punct.as_char(), ','), 18 None => break, 19 _ => panic!("Expected ',' or end of array"), 20 } 21 } 22 values 23 } 24 25 struct ModInfoBuilder<'a> { 26 module: &'a str, 27 counter: usize, 28 buffer: String, 29 } 30 31 impl<'a> ModInfoBuilder<'a> { 32 fn new(module: &'a str) -> Self { 33 ModInfoBuilder { 34 module, 35 counter: 0, 36 buffer: String::new(), 37 } 38 } 39 40 fn emit_base(&mut self, field: &str, content: &str, builtin: bool) { 41 let string = if builtin { 42 // Built-in modules prefix their modinfo strings by `module.`. 43 format!( 44 "{module}.{field}={content}\0", 45 module = self.module, 46 field = field, 47 content = content 48 ) 49 } else { 50 // Loadable modules' modinfo strings go as-is. 51 format!("{field}={content}\0", field = field, content = content) 52 }; 53 54 write!( 55 &mut self.buffer, 56 " 57 {cfg} 58 #[doc(hidden)] 59 #[cfg_attr(not(target_os = \"macos\"), link_section = \".modinfo\")] 60 #[used] 61 pub static __{module}_{counter}: [u8; {length}] = *{string}; 62 ", 63 cfg = if builtin { 64 "#[cfg(not(MODULE))]" 65 } else { 66 "#[cfg(MODULE)]" 67 }, 68 module = self.module.to_uppercase(), 69 counter = self.counter, 70 length = string.len(), 71 string = Literal::byte_string(string.as_bytes()), 72 ) 73 .unwrap(); 74 75 self.counter += 1; 76 } 77 78 fn emit_only_builtin(&mut self, field: &str, content: &str) { 79 self.emit_base(field, content, true) 80 } 81 82 fn emit_only_loadable(&mut self, field: &str, content: &str) { 83 self.emit_base(field, content, false) 84 } 85 86 fn emit(&mut self, field: &str, content: &str) { 87 self.emit_only_builtin(field, content); 88 self.emit_only_loadable(field, content); 89 } 90 } 91 92 #[derive(Debug, Default)] 93 struct ModuleInfo { 94 type_: String, 95 license: String, 96 name: String, 97 author: Option<String>, 98 authors: Option<Vec<String>>, 99 description: Option<String>, 100 alias: Option<Vec<String>>, 101 firmware: Option<Vec<String>>, 102 } 103 104 impl ModuleInfo { 105 fn parse(it: &mut token_stream::IntoIter) -> Self { 106 let mut info = ModuleInfo::default(); 107 108 const EXPECTED_KEYS: &[&str] = &[ 109 "type", 110 "name", 111 "author", 112 "authors", 113 "description", 114 "license", 115 "alias", 116 "firmware", 117 ]; 118 const REQUIRED_KEYS: &[&str] = &["type", "name", "license"]; 119 let mut seen_keys = Vec::new(); 120 121 loop { 122 let key = match it.next() { 123 Some(TokenTree::Ident(ident)) => ident.to_string(), 124 Some(_) => panic!("Expected Ident or end"), 125 None => break, 126 }; 127 128 if seen_keys.contains(&key) { 129 panic!( 130 "Duplicated key \"{}\". Keys can only be specified once.", 131 key 132 ); 133 } 134 135 assert_eq!(expect_punct(it), ':'); 136 137 match key.as_str() { 138 "type" => info.type_ = expect_ident(it), 139 "name" => info.name = expect_string_ascii(it), 140 "author" => info.author = Some(expect_string(it)), 141 "authors" => info.authors = Some(expect_string_array(it)), 142 "description" => info.description = Some(expect_string(it)), 143 "license" => info.license = expect_string_ascii(it), 144 "alias" => info.alias = Some(expect_string_array(it)), 145 "firmware" => info.firmware = Some(expect_string_array(it)), 146 _ => panic!( 147 "Unknown key \"{}\". Valid keys are: {:?}.", 148 key, EXPECTED_KEYS 149 ), 150 } 151 152 assert_eq!(expect_punct(it), ','); 153 154 seen_keys.push(key); 155 } 156 157 expect_end(it); 158 159 for key in REQUIRED_KEYS { 160 if !seen_keys.iter().any(|e| e == key) { 161 panic!("Missing required key \"{}\".", key); 162 } 163 } 164 165 let mut ordered_keys: Vec<&str> = Vec::new(); 166 for key in EXPECTED_KEYS { 167 if seen_keys.iter().any(|e| e == key) { 168 ordered_keys.push(key); 169 } 170 } 171 172 if seen_keys != ordered_keys { 173 panic!( 174 "Keys are not ordered as expected. Order them like: {:?}.", 175 ordered_keys 176 ); 177 } 178 179 info 180 } 181 } 182 183 pub(crate) fn module(ts: TokenStream) -> TokenStream { 184 let mut it = ts.into_iter(); 185 186 let info = ModuleInfo::parse(&mut it); 187 188 let mut modinfo = ModInfoBuilder::new(info.name.as_ref()); 189 if let Some(author) = info.author { 190 modinfo.emit("author", &author); 191 } 192 if let Some(authors) = info.authors { 193 for author in authors { 194 modinfo.emit("author", &author); 195 } 196 } 197 if let Some(description) = info.description { 198 modinfo.emit("description", &description); 199 } 200 modinfo.emit("license", &info.license); 201 if let Some(aliases) = info.alias { 202 for alias in aliases { 203 modinfo.emit("alias", &alias); 204 } 205 } 206 if let Some(firmware) = info.firmware { 207 for fw in firmware { 208 modinfo.emit("firmware", &fw); 209 } 210 } 211 212 // Built-in modules also export the `file` modinfo string. 213 let file = 214 std::env::var("RUST_MODFILE").expect("Unable to fetch RUST_MODFILE environmental variable"); 215 modinfo.emit_only_builtin("file", &file); 216 217 format!( 218 " 219 /// The module name. 220 /// 221 /// Used by the printing macros, e.g. [`info!`]. 222 const __LOG_PREFIX: &[u8] = b\"{name}\\0\"; 223 224 // SAFETY: `__this_module` is constructed by the kernel at load time and will not be 225 // freed until the module is unloaded. 226 #[cfg(MODULE)] 227 static THIS_MODULE: kernel::ThisModule = unsafe {{ 228 extern \"C\" {{ 229 static __this_module: kernel::types::Opaque<kernel::bindings::module>; 230 }} 231 232 kernel::ThisModule::from_ptr(__this_module.get()) 233 }}; 234 #[cfg(not(MODULE))] 235 static THIS_MODULE: kernel::ThisModule = unsafe {{ 236 kernel::ThisModule::from_ptr(core::ptr::null_mut()) 237 }}; 238 239 /// The `LocalModule` type is the type of the module created by `module!`, 240 /// `module_pci_driver!`, `module_platform_driver!`, etc. 241 type LocalModule = {type_}; 242 243 impl kernel::ModuleMetadata for {type_} {{ 244 const NAME: &'static kernel::str::CStr = kernel::c_str!(\"{name}\"); 245 }} 246 247 // Double nested modules, since then nobody can access the public items inside. 248 mod __module_init {{ 249 mod __module_init {{ 250 use super::super::{type_}; 251 use pin_init::PinInit; 252 253 /// The \"Rust loadable module\" mark. 254 // 255 // This may be best done another way later on, e.g. as a new modinfo 256 // key or a new section. For the moment, keep it simple. 257 #[cfg(MODULE)] 258 #[doc(hidden)] 259 #[used] 260 static __IS_RUST_MODULE: () = (); 261 262 static mut __MOD: core::mem::MaybeUninit<{type_}> = 263 core::mem::MaybeUninit::uninit(); 264 265 // Loadable modules need to export the `{{init,cleanup}}_module` identifiers. 266 /// # Safety 267 /// 268 /// This function must not be called after module initialization, because it may be 269 /// freed after that completes. 270 #[cfg(MODULE)] 271 #[doc(hidden)] 272 #[no_mangle] 273 #[link_section = \".init.text\"] 274 pub unsafe extern \"C\" fn init_module() -> kernel::ffi::c_int {{ 275 // SAFETY: This function is inaccessible to the outside due to the double 276 // module wrapping it. It is called exactly once by the C side via its 277 // unique name. 278 unsafe {{ __init() }} 279 }} 280 281 #[cfg(MODULE)] 282 #[doc(hidden)] 283 #[used] 284 #[link_section = \".init.data\"] 285 static __UNIQUE_ID___addressable_init_module: unsafe extern \"C\" fn() -> i32 = init_module; 286 287 #[cfg(MODULE)] 288 #[doc(hidden)] 289 #[no_mangle] 290 pub extern \"C\" fn cleanup_module() {{ 291 // SAFETY: 292 // - This function is inaccessible to the outside due to the double 293 // module wrapping it. It is called exactly once by the C side via its 294 // unique name, 295 // - furthermore it is only called after `init_module` has returned `0` 296 // (which delegates to `__init`). 297 unsafe {{ __exit() }} 298 }} 299 300 #[cfg(MODULE)] 301 #[doc(hidden)] 302 #[used] 303 #[link_section = \".exit.data\"] 304 static __UNIQUE_ID___addressable_cleanup_module: extern \"C\" fn() = cleanup_module; 305 306 // Built-in modules are initialized through an initcall pointer 307 // and the identifiers need to be unique. 308 #[cfg(not(MODULE))] 309 #[cfg(not(CONFIG_HAVE_ARCH_PREL32_RELOCATIONS))] 310 #[doc(hidden)] 311 #[link_section = \"{initcall_section}\"] 312 #[used] 313 pub static __{name}_initcall: extern \"C\" fn() -> kernel::ffi::c_int = __{name}_init; 314 315 #[cfg(not(MODULE))] 316 #[cfg(CONFIG_HAVE_ARCH_PREL32_RELOCATIONS)] 317 core::arch::global_asm!( 318 r#\".section \"{initcall_section}\", \"a\" 319 __{name}_initcall: 320 .long __{name}_init - . 321 .previous 322 \"# 323 ); 324 325 #[cfg(not(MODULE))] 326 #[doc(hidden)] 327 #[no_mangle] 328 pub extern \"C\" fn __{name}_init() -> kernel::ffi::c_int {{ 329 // SAFETY: This function is inaccessible to the outside due to the double 330 // module wrapping it. It is called exactly once by the C side via its 331 // placement above in the initcall section. 332 unsafe {{ __init() }} 333 }} 334 335 #[cfg(not(MODULE))] 336 #[doc(hidden)] 337 #[no_mangle] 338 pub extern \"C\" fn __{name}_exit() {{ 339 // SAFETY: 340 // - This function is inaccessible to the outside due to the double 341 // module wrapping it. It is called exactly once by the C side via its 342 // unique name, 343 // - furthermore it is only called after `__{name}_init` has returned `0` 344 // (which delegates to `__init`). 345 unsafe {{ __exit() }} 346 }} 347 348 /// # Safety 349 /// 350 /// This function must only be called once. 351 unsafe fn __init() -> kernel::ffi::c_int {{ 352 let initer = 353 <{type_} as kernel::InPlaceModule>::init(&super::super::THIS_MODULE); 354 // SAFETY: No data race, since `__MOD` can only be accessed by this module 355 // and there only `__init` and `__exit` access it. These functions are only 356 // called once and `__exit` cannot be called before or during `__init`. 357 match unsafe {{ initer.__pinned_init(__MOD.as_mut_ptr()) }} {{ 358 Ok(m) => 0, 359 Err(e) => e.to_errno(), 360 }} 361 }} 362 363 /// # Safety 364 /// 365 /// This function must 366 /// - only be called once, 367 /// - be called after `__init` has been called and returned `0`. 368 unsafe fn __exit() {{ 369 // SAFETY: No data race, since `__MOD` can only be accessed by this module 370 // and there only `__init` and `__exit` access it. These functions are only 371 // called once and `__init` was already called. 372 unsafe {{ 373 // Invokes `drop()` on `__MOD`, which should be used for cleanup. 374 __MOD.assume_init_drop(); 375 }} 376 }} 377 378 {modinfo} 379 }} 380 }} 381 ", 382 type_ = info.type_, 383 name = info.name, 384 modinfo = modinfo.buffer, 385 initcall_section = ".initcall6.init" 386 ) 387 .parse() 388 .expect("Error parsing formatted string into token stream.") 389 } 390