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 } 102 103 impl ModuleInfo { 104 fn parse(it: &mut token_stream::IntoIter) -> Self { 105 let mut info = ModuleInfo::default(); 106 107 const EXPECTED_KEYS: &[&str] = &[ 108 "type", 109 "name", 110 "authors", 111 "description", 112 "license", 113 "alias", 114 "firmware", 115 ]; 116 const REQUIRED_KEYS: &[&str] = &["type", "name", "license"]; 117 let mut seen_keys = Vec::new(); 118 119 loop { 120 let key = match it.next() { 121 Some(TokenTree::Ident(ident)) => ident.to_string(), 122 Some(_) => panic!("Expected Ident or end"), 123 None => break, 124 }; 125 126 if seen_keys.contains(&key) { 127 panic!("Duplicated key \"{key}\". Keys can only be specified once."); 128 } 129 130 assert_eq!(expect_punct(it), ':'); 131 132 match key.as_str() { 133 "type" => info.type_ = expect_ident(it), 134 "name" => info.name = expect_string_ascii(it), 135 "authors" => info.authors = Some(expect_string_array(it)), 136 "description" => info.description = Some(expect_string(it)), 137 "license" => info.license = expect_string_ascii(it), 138 "alias" => info.alias = Some(expect_string_array(it)), 139 "firmware" => info.firmware = Some(expect_string_array(it)), 140 _ => panic!("Unknown key \"{key}\". Valid keys are: {EXPECTED_KEYS:?}."), 141 } 142 143 assert_eq!(expect_punct(it), ','); 144 145 seen_keys.push(key); 146 } 147 148 expect_end(it); 149 150 for key in REQUIRED_KEYS { 151 if !seen_keys.iter().any(|e| e == key) { 152 panic!("Missing required key \"{key}\"."); 153 } 154 } 155 156 let mut ordered_keys: Vec<&str> = Vec::new(); 157 for key in EXPECTED_KEYS { 158 if seen_keys.iter().any(|e| e == key) { 159 ordered_keys.push(key); 160 } 161 } 162 163 if seen_keys != ordered_keys { 164 panic!("Keys are not ordered as expected. Order them like: {ordered_keys:?}."); 165 } 166 167 info 168 } 169 } 170 171 pub(crate) fn module(ts: TokenStream) -> TokenStream { 172 let mut it = ts.into_iter(); 173 174 let info = ModuleInfo::parse(&mut it); 175 176 // Rust does not allow hyphens in identifiers, use underscore instead. 177 let ident = info.name.replace('-', "_"); 178 let mut modinfo = ModInfoBuilder::new(ident.as_ref()); 179 if let Some(authors) = info.authors { 180 for author in authors { 181 modinfo.emit("author", &author); 182 } 183 } 184 if let Some(description) = info.description { 185 modinfo.emit("description", &description); 186 } 187 modinfo.emit("license", &info.license); 188 if let Some(aliases) = info.alias { 189 for alias in aliases { 190 modinfo.emit("alias", &alias); 191 } 192 } 193 if let Some(firmware) = info.firmware { 194 for fw in firmware { 195 modinfo.emit("firmware", &fw); 196 } 197 } 198 199 // Built-in modules also export the `file` modinfo string. 200 let file = 201 std::env::var("RUST_MODFILE").expect("Unable to fetch RUST_MODFILE environmental variable"); 202 modinfo.emit_only_builtin("file", &file); 203 204 format!( 205 " 206 /// The module name. 207 /// 208 /// Used by the printing macros, e.g. [`info!`]. 209 const __LOG_PREFIX: &[u8] = b\"{name}\\0\"; 210 211 // SAFETY: `__this_module` is constructed by the kernel at load time and will not be 212 // freed until the module is unloaded. 213 #[cfg(MODULE)] 214 static THIS_MODULE: ::kernel::ThisModule = unsafe {{ 215 extern \"C\" {{ 216 static __this_module: ::kernel::types::Opaque<::kernel::bindings::module>; 217 }} 218 219 ::kernel::ThisModule::from_ptr(__this_module.get()) 220 }}; 221 #[cfg(not(MODULE))] 222 static THIS_MODULE: ::kernel::ThisModule = unsafe {{ 223 ::kernel::ThisModule::from_ptr(::core::ptr::null_mut()) 224 }}; 225 226 /// The `LocalModule` type is the type of the module created by `module!`, 227 /// `module_pci_driver!`, `module_platform_driver!`, etc. 228 type LocalModule = {type_}; 229 230 impl ::kernel::ModuleMetadata for {type_} {{ 231 const NAME: &'static ::kernel::str::CStr = ::kernel::c_str!(\"{name}\"); 232 }} 233 234 // Double nested modules, since then nobody can access the public items inside. 235 mod __module_init {{ 236 mod __module_init {{ 237 use super::super::{type_}; 238 use pin_init::PinInit; 239 240 /// The \"Rust loadable module\" mark. 241 // 242 // This may be best done another way later on, e.g. as a new modinfo 243 // key or a new section. For the moment, keep it simple. 244 #[cfg(MODULE)] 245 #[doc(hidden)] 246 #[used(compiler)] 247 static __IS_RUST_MODULE: () = (); 248 249 static mut __MOD: ::core::mem::MaybeUninit<{type_}> = 250 ::core::mem::MaybeUninit::uninit(); 251 252 // Loadable modules need to export the `{{init,cleanup}}_module` identifiers. 253 /// # Safety 254 /// 255 /// This function must not be called after module initialization, because it may be 256 /// freed after that completes. 257 #[cfg(MODULE)] 258 #[doc(hidden)] 259 #[no_mangle] 260 #[link_section = \".init.text\"] 261 pub unsafe extern \"C\" fn init_module() -> ::kernel::ffi::c_int {{ 262 // SAFETY: This function is inaccessible to the outside due to the double 263 // module wrapping it. It is called exactly once by the C side via its 264 // unique name. 265 unsafe {{ __init() }} 266 }} 267 268 #[cfg(MODULE)] 269 #[doc(hidden)] 270 #[used(compiler)] 271 #[link_section = \".init.data\"] 272 static __UNIQUE_ID___addressable_init_module: unsafe extern \"C\" fn() -> i32 = init_module; 273 274 #[cfg(MODULE)] 275 #[doc(hidden)] 276 #[no_mangle] 277 #[link_section = \".exit.text\"] 278 pub extern \"C\" fn cleanup_module() {{ 279 // SAFETY: 280 // - This function is inaccessible to the outside due to the double 281 // module wrapping it. It is called exactly once by the C side via its 282 // unique name, 283 // - furthermore it is only called after `init_module` has returned `0` 284 // (which delegates to `__init`). 285 unsafe {{ __exit() }} 286 }} 287 288 #[cfg(MODULE)] 289 #[doc(hidden)] 290 #[used(compiler)] 291 #[link_section = \".exit.data\"] 292 static __UNIQUE_ID___addressable_cleanup_module: extern \"C\" fn() = cleanup_module; 293 294 // Built-in modules are initialized through an initcall pointer 295 // and the identifiers need to be unique. 296 #[cfg(not(MODULE))] 297 #[cfg(not(CONFIG_HAVE_ARCH_PREL32_RELOCATIONS))] 298 #[doc(hidden)] 299 #[link_section = \"{initcall_section}\"] 300 #[used(compiler)] 301 pub static __{ident}_initcall: extern \"C\" fn() -> 302 ::kernel::ffi::c_int = __{ident}_init; 303 304 #[cfg(not(MODULE))] 305 #[cfg(CONFIG_HAVE_ARCH_PREL32_RELOCATIONS)] 306 ::core::arch::global_asm!( 307 r#\".section \"{initcall_section}\", \"a\" 308 __{ident}_initcall: 309 .long __{ident}_init - . 310 .previous 311 \"# 312 ); 313 314 #[cfg(not(MODULE))] 315 #[doc(hidden)] 316 #[no_mangle] 317 pub extern \"C\" fn __{ident}_init() -> ::kernel::ffi::c_int {{ 318 // SAFETY: This function is inaccessible to the outside due to the double 319 // module wrapping it. It is called exactly once by the C side via its 320 // placement above in the initcall section. 321 unsafe {{ __init() }} 322 }} 323 324 #[cfg(not(MODULE))] 325 #[doc(hidden)] 326 #[no_mangle] 327 pub extern \"C\" fn __{ident}_exit() {{ 328 // SAFETY: 329 // - 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 // unique name, 332 // - furthermore it is only called after `__{ident}_init` has 333 // returned `0` (which delegates to `__init`). 334 unsafe {{ __exit() }} 335 }} 336 337 /// # Safety 338 /// 339 /// This function must only be called once. 340 unsafe fn __init() -> ::kernel::ffi::c_int {{ 341 let initer = 342 <{type_} as ::kernel::InPlaceModule>::init(&super::super::THIS_MODULE); 343 // SAFETY: No data race, since `__MOD` can only be accessed by this module 344 // and there only `__init` and `__exit` access it. These functions are only 345 // called once and `__exit` cannot be called before or during `__init`. 346 match unsafe {{ initer.__pinned_init(__MOD.as_mut_ptr()) }} {{ 347 Ok(m) => 0, 348 Err(e) => e.to_errno(), 349 }} 350 }} 351 352 /// # Safety 353 /// 354 /// This function must 355 /// - only be called once, 356 /// - be called after `__init` has been called and returned `0`. 357 unsafe fn __exit() {{ 358 // SAFETY: No data race, since `__MOD` can only be accessed by this module 359 // and there only `__init` and `__exit` access it. These functions are only 360 // called once and `__init` was already called. 361 unsafe {{ 362 // Invokes `drop()` on `__MOD`, which should be used for cleanup. 363 __MOD.assume_init_drop(); 364 }} 365 }} 366 367 {modinfo} 368 }} 369 }} 370 ", 371 type_ = info.type_, 372 name = info.name, 373 ident = ident, 374 modinfo = modinfo.buffer, 375 initcall_section = ".initcall6.init" 376 ) 377 .parse() 378 .expect("Error parsing formatted string into token stream.") 379 } 380