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