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") 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(compiler)] 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 authors: Option<Vec<String>>, 98 description: Option<String>, 99 alias: Option<Vec<String>>, 100 firmware: Option<Vec<String>>, 101 imports_ns: 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 "authors", 112 "description", 113 "license", 114 "alias", 115 "firmware", 116 "imports_ns", 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!("Duplicated key \"{key}\". Keys can only be specified once."); 130 } 131 132 assert_eq!(expect_punct(it), ':'); 133 134 match key.as_str() { 135 "type" => info.type_ = expect_ident(it), 136 "name" => info.name = expect_string_ascii(it), 137 "authors" => info.authors = Some(expect_string_array(it)), 138 "description" => info.description = Some(expect_string(it)), 139 "license" => info.license = expect_string_ascii(it), 140 "alias" => info.alias = Some(expect_string_array(it)), 141 "firmware" => info.firmware = Some(expect_string_array(it)), 142 "imports_ns" => info.imports_ns = Some(expect_string_array(it)), 143 _ => panic!("Unknown key \"{key}\". Valid keys are: {EXPECTED_KEYS:?}."), 144 } 145 146 assert_eq!(expect_punct(it), ','); 147 148 seen_keys.push(key); 149 } 150 151 expect_end(it); 152 153 for key in REQUIRED_KEYS { 154 if !seen_keys.iter().any(|e| e == key) { 155 panic!("Missing required key \"{key}\"."); 156 } 157 } 158 159 let mut ordered_keys: Vec<&str> = Vec::new(); 160 for key in EXPECTED_KEYS { 161 if seen_keys.iter().any(|e| e == key) { 162 ordered_keys.push(key); 163 } 164 } 165 166 if seen_keys != ordered_keys { 167 panic!("Keys are not ordered as expected. Order them like: {ordered_keys:?}."); 168 } 169 170 info 171 } 172 } 173 174 pub(crate) fn module(ts: TokenStream) -> TokenStream { 175 let mut it = ts.into_iter(); 176 177 let info = ModuleInfo::parse(&mut it); 178 179 // Rust does not allow hyphens in identifiers, use underscore instead. 180 let ident = info.name.replace('-', "_"); 181 let mut modinfo = ModInfoBuilder::new(ident.as_ref()); 182 if let Some(authors) = info.authors { 183 for author in authors { 184 modinfo.emit("author", &author); 185 } 186 } 187 if let Some(description) = info.description { 188 modinfo.emit("description", &description); 189 } 190 modinfo.emit("license", &info.license); 191 if let Some(aliases) = info.alias { 192 for alias in aliases { 193 modinfo.emit("alias", &alias); 194 } 195 } 196 if let Some(firmware) = info.firmware { 197 for fw in firmware { 198 modinfo.emit("firmware", &fw); 199 } 200 } 201 if let Some(imports) = info.imports_ns { 202 for ns in imports { 203 modinfo.emit("import_ns", &ns); 204 } 205 } 206 207 // Built-in modules also export the `file` modinfo string. 208 let file = 209 std::env::var("RUST_MODFILE").expect("Unable to fetch RUST_MODFILE environmental variable"); 210 modinfo.emit_only_builtin("file", &file); 211 212 format!( 213 " 214 /// The module name. 215 /// 216 /// Used by the printing macros, e.g. [`info!`]. 217 const __LOG_PREFIX: &[u8] = b\"{name}\\0\"; 218 219 // SAFETY: `__this_module` is constructed by the kernel at load time and will not be 220 // freed until the module is unloaded. 221 #[cfg(MODULE)] 222 static THIS_MODULE: ::kernel::ThisModule = unsafe {{ 223 extern \"C\" {{ 224 static __this_module: ::kernel::types::Opaque<::kernel::bindings::module>; 225 }} 226 227 ::kernel::ThisModule::from_ptr(__this_module.get()) 228 }}; 229 #[cfg(not(MODULE))] 230 static THIS_MODULE: ::kernel::ThisModule = unsafe {{ 231 ::kernel::ThisModule::from_ptr(::core::ptr::null_mut()) 232 }}; 233 234 /// The `LocalModule` type is the type of the module created by `module!`, 235 /// `module_pci_driver!`, `module_platform_driver!`, etc. 236 type LocalModule = {type_}; 237 238 impl ::kernel::ModuleMetadata for {type_} {{ 239 const NAME: &'static ::kernel::str::CStr = c\"{name}\"; 240 }} 241 242 // Double nested modules, since then nobody can access the public items inside. 243 mod __module_init {{ 244 mod __module_init {{ 245 use super::super::{type_}; 246 use pin_init::PinInit; 247 248 /// The \"Rust loadable module\" mark. 249 // 250 // This may be best done another way later on, e.g. as a new modinfo 251 // key or a new section. For the moment, keep it simple. 252 #[cfg(MODULE)] 253 #[doc(hidden)] 254 #[used(compiler)] 255 static __IS_RUST_MODULE: () = (); 256 257 static mut __MOD: ::core::mem::MaybeUninit<{type_}> = 258 ::core::mem::MaybeUninit::uninit(); 259 260 // Loadable modules need to export the `{{init,cleanup}}_module` identifiers. 261 /// # Safety 262 /// 263 /// This function must not be called after module initialization, because it may be 264 /// freed after that completes. 265 #[cfg(MODULE)] 266 #[doc(hidden)] 267 #[no_mangle] 268 #[link_section = \".init.text\"] 269 pub unsafe extern \"C\" fn init_module() -> ::kernel::ffi::c_int {{ 270 // SAFETY: This function is inaccessible to the outside due to the double 271 // module wrapping it. It is called exactly once by the C side via its 272 // unique name. 273 unsafe {{ __init() }} 274 }} 275 276 #[cfg(MODULE)] 277 #[doc(hidden)] 278 #[used(compiler)] 279 #[link_section = \".init.data\"] 280 static __UNIQUE_ID___addressable_init_module: unsafe extern \"C\" fn() -> i32 = init_module; 281 282 #[cfg(MODULE)] 283 #[doc(hidden)] 284 #[no_mangle] 285 #[link_section = \".exit.text\"] 286 pub extern \"C\" fn cleanup_module() {{ 287 // SAFETY: 288 // - This function is inaccessible to the outside due to the double 289 // module wrapping it. It is called exactly once by the C side via its 290 // unique name, 291 // - furthermore it is only called after `init_module` has returned `0` 292 // (which delegates to `__init`). 293 unsafe {{ __exit() }} 294 }} 295 296 #[cfg(MODULE)] 297 #[doc(hidden)] 298 #[used(compiler)] 299 #[link_section = \".exit.data\"] 300 static __UNIQUE_ID___addressable_cleanup_module: extern \"C\" fn() = cleanup_module; 301 302 // Built-in modules are initialized through an initcall pointer 303 // and the identifiers need to be unique. 304 #[cfg(not(MODULE))] 305 #[cfg(not(CONFIG_HAVE_ARCH_PREL32_RELOCATIONS))] 306 #[doc(hidden)] 307 #[link_section = \"{initcall_section}\"] 308 #[used(compiler)] 309 pub static __{ident}_initcall: extern \"C\" fn() -> 310 ::kernel::ffi::c_int = __{ident}_init; 311 312 #[cfg(not(MODULE))] 313 #[cfg(CONFIG_HAVE_ARCH_PREL32_RELOCATIONS)] 314 ::core::arch::global_asm!( 315 r#\".section \"{initcall_section}\", \"a\" 316 __{ident}_initcall: 317 .long __{ident}_init - . 318 .previous 319 \"# 320 ); 321 322 #[cfg(not(MODULE))] 323 #[doc(hidden)] 324 #[no_mangle] 325 pub extern \"C\" fn __{ident}_init() -> ::kernel::ffi::c_int {{ 326 // SAFETY: This function is inaccessible to the outside due to the double 327 // module wrapping it. It is called exactly once by the C side via its 328 // placement above in the initcall section. 329 unsafe {{ __init() }} 330 }} 331 332 #[cfg(not(MODULE))] 333 #[doc(hidden)] 334 #[no_mangle] 335 pub extern \"C\" fn __{ident}_exit() {{ 336 // SAFETY: 337 // - This function is inaccessible to the outside due to the double 338 // module wrapping it. It is called exactly once by the C side via its 339 // unique name, 340 // - furthermore it is only called after `__{ident}_init` has 341 // returned `0` (which delegates to `__init`). 342 unsafe {{ __exit() }} 343 }} 344 345 /// # Safety 346 /// 347 /// This function must only be called once. 348 unsafe fn __init() -> ::kernel::ffi::c_int {{ 349 let initer = 350 <{type_} as ::kernel::InPlaceModule>::init(&super::super::THIS_MODULE); 351 // SAFETY: No data race, since `__MOD` can only be accessed by this module 352 // and there only `__init` and `__exit` access it. These functions are only 353 // called once and `__exit` cannot be called before or during `__init`. 354 match unsafe {{ initer.__pinned_init(__MOD.as_mut_ptr()) }} {{ 355 Ok(m) => 0, 356 Err(e) => e.to_errno(), 357 }} 358 }} 359 360 /// # Safety 361 /// 362 /// This function must 363 /// - only be called once, 364 /// - be called after `__init` has been called and returned `0`. 365 unsafe fn __exit() {{ 366 // SAFETY: No data race, since `__MOD` can only be accessed by this module 367 // and there only `__init` and `__exit` access it. These functions are only 368 // called once and `__init` was already called. 369 unsafe {{ 370 // Invokes `drop()` on `__MOD`, which should be used for cleanup. 371 __MOD.assume_init_drop(); 372 }} 373 }} 374 375 {modinfo} 376 }} 377 }} 378 ", 379 type_ = info.type_, 380 name = info.name, 381 ident = ident, 382 modinfo = modinfo.buffer, 383 initcall_section = ".initcall6.init" 384 ) 385 .parse() 386 .expect("Error parsing formatted string into token stream.") 387 } 388