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 #[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 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 "author", 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!( 128 "Duplicated key \"{}\". Keys can only be specified once.", 129 key 130 ); 131 } 132 133 assert_eq!(expect_punct(it), ':'); 134 135 match key.as_str() { 136 "type" => info.type_ = expect_ident(it), 137 "name" => info.name = expect_string_ascii(it), 138 "author" => info.author = Some(expect_string(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!( 144 "Unknown key \"{}\". Valid keys are: {:?}.", 145 key, EXPECTED_KEYS 146 ), 147 } 148 149 assert_eq!(expect_punct(it), ','); 150 151 seen_keys.push(key); 152 } 153 154 expect_end(it); 155 156 for key in REQUIRED_KEYS { 157 if !seen_keys.iter().any(|e| e == key) { 158 panic!("Missing required key \"{}\".", key); 159 } 160 } 161 162 let mut ordered_keys: Vec<&str> = Vec::new(); 163 for key in EXPECTED_KEYS { 164 if seen_keys.iter().any(|e| e == key) { 165 ordered_keys.push(key); 166 } 167 } 168 169 if seen_keys != ordered_keys { 170 panic!( 171 "Keys are not ordered as expected. Order them like: {:?}.", 172 ordered_keys 173 ); 174 } 175 176 info 177 } 178 } 179 180 pub(crate) fn module(ts: TokenStream) -> TokenStream { 181 let mut it = ts.into_iter(); 182 183 let info = ModuleInfo::parse(&mut it); 184 185 let mut modinfo = ModInfoBuilder::new(info.name.as_ref()); 186 if let Some(author) = info.author { 187 modinfo.emit("author", &author); 188 } 189 if let Some(description) = info.description { 190 modinfo.emit("description", &description); 191 } 192 modinfo.emit("license", &info.license); 193 if let Some(aliases) = info.alias { 194 for alias in aliases { 195 modinfo.emit("alias", &alias); 196 } 197 } 198 if let Some(firmware) = info.firmware { 199 for fw in firmware { 200 modinfo.emit("firmware", &fw); 201 } 202 } 203 204 // Built-in modules also export the `file` modinfo string. 205 let file = 206 std::env::var("RUST_MODFILE").expect("Unable to fetch RUST_MODFILE environmental variable"); 207 modinfo.emit_only_builtin("file", &file); 208 209 format!( 210 " 211 /// The module name. 212 /// 213 /// Used by the printing macros, e.g. [`info!`]. 214 const __LOG_PREFIX: &[u8] = b\"{name}\\0\"; 215 216 // SAFETY: `__this_module` is constructed by the kernel at load time and will not be 217 // freed until the module is unloaded. 218 #[cfg(MODULE)] 219 static THIS_MODULE: kernel::ThisModule = unsafe {{ 220 extern \"C\" {{ 221 static __this_module: kernel::types::Opaque<kernel::bindings::module>; 222 }} 223 224 kernel::ThisModule::from_ptr(__this_module.get()) 225 }}; 226 #[cfg(not(MODULE))] 227 static THIS_MODULE: kernel::ThisModule = unsafe {{ 228 kernel::ThisModule::from_ptr(core::ptr::null_mut()) 229 }}; 230 231 // Double nested modules, since then nobody can access the public items inside. 232 mod __module_init {{ 233 mod __module_init {{ 234 use super::super::{type_}; 235 use kernel::init::PinInit; 236 237 /// The \"Rust loadable module\" mark. 238 // 239 // This may be best done another way later on, e.g. as a new modinfo 240 // key or a new section. For the moment, keep it simple. 241 #[cfg(MODULE)] 242 #[doc(hidden)] 243 #[used] 244 static __IS_RUST_MODULE: () = (); 245 246 static mut __MOD: core::mem::MaybeUninit<{type_}> = 247 core::mem::MaybeUninit::uninit(); 248 249 // Loadable modules need to export the `{{init,cleanup}}_module` identifiers. 250 /// # Safety 251 /// 252 /// This function must not be called after module initialization, because it may be 253 /// freed after that completes. 254 #[cfg(MODULE)] 255 #[doc(hidden)] 256 #[no_mangle] 257 #[link_section = \".init.text\"] 258 pub unsafe extern \"C\" fn init_module() -> kernel::ffi::c_int {{ 259 // SAFETY: This function is inaccessible to the outside due to the double 260 // module wrapping it. It is called exactly once by the C side via its 261 // unique name. 262 unsafe {{ __init() }} 263 }} 264 265 #[cfg(MODULE)] 266 #[doc(hidden)] 267 #[used] 268 #[link_section = \".init.data\"] 269 static __UNIQUE_ID___addressable_init_module: unsafe extern \"C\" fn() -> i32 = init_module; 270 271 #[cfg(MODULE)] 272 #[doc(hidden)] 273 #[no_mangle] 274 pub extern \"C\" fn cleanup_module() {{ 275 // SAFETY: 276 // - This function is inaccessible to the outside due to the double 277 // module wrapping it. It is called exactly once by the C side via its 278 // unique name, 279 // - furthermore it is only called after `init_module` has returned `0` 280 // (which delegates to `__init`). 281 unsafe {{ __exit() }} 282 }} 283 284 #[cfg(MODULE)] 285 #[doc(hidden)] 286 #[used] 287 #[link_section = \".exit.data\"] 288 static __UNIQUE_ID___addressable_cleanup_module: extern \"C\" fn() = cleanup_module; 289 290 // Built-in modules are initialized through an initcall pointer 291 // and the identifiers need to be unique. 292 #[cfg(not(MODULE))] 293 #[cfg(not(CONFIG_HAVE_ARCH_PREL32_RELOCATIONS))] 294 #[doc(hidden)] 295 #[link_section = \"{initcall_section}\"] 296 #[used] 297 pub static __{name}_initcall: extern \"C\" fn() -> kernel::ffi::c_int = __{name}_init; 298 299 #[cfg(not(MODULE))] 300 #[cfg(CONFIG_HAVE_ARCH_PREL32_RELOCATIONS)] 301 core::arch::global_asm!( 302 r#\".section \"{initcall_section}\", \"a\" 303 __{name}_initcall: 304 .long __{name}_init - . 305 .previous 306 \"# 307 ); 308 309 #[cfg(not(MODULE))] 310 #[doc(hidden)] 311 #[no_mangle] 312 pub extern \"C\" fn __{name}_init() -> kernel::ffi::c_int {{ 313 // SAFETY: This function is inaccessible to the outside due to the double 314 // module wrapping it. It is called exactly once by the C side via its 315 // placement above in the initcall section. 316 unsafe {{ __init() }} 317 }} 318 319 #[cfg(not(MODULE))] 320 #[doc(hidden)] 321 #[no_mangle] 322 pub extern \"C\" fn __{name}_exit() {{ 323 // SAFETY: 324 // - This function is inaccessible to the outside due to the double 325 // module wrapping it. It is called exactly once by the C side via its 326 // unique name, 327 // - furthermore it is only called after `__{name}_init` has returned `0` 328 // (which delegates to `__init`). 329 unsafe {{ __exit() }} 330 }} 331 332 /// # Safety 333 /// 334 /// This function must only be called once. 335 unsafe fn __init() -> kernel::ffi::c_int {{ 336 let initer = 337 <{type_} as kernel::InPlaceModule>::init(&super::super::THIS_MODULE); 338 // SAFETY: No data race, since `__MOD` can only be accessed by this module 339 // and there only `__init` and `__exit` access it. These functions are only 340 // called once and `__exit` cannot be called before or during `__init`. 341 match unsafe {{ initer.__pinned_init(__MOD.as_mut_ptr()) }} {{ 342 Ok(m) => 0, 343 Err(e) => e.to_errno(), 344 }} 345 }} 346 347 /// # Safety 348 /// 349 /// This function must 350 /// - only be called once, 351 /// - be called after `__init` has been called and returned `0`. 352 unsafe fn __exit() {{ 353 // SAFETY: No data race, since `__MOD` can only be accessed by this module 354 // and there only `__init` and `__exit` access it. These functions are only 355 // called once and `__init` was already called. 356 unsafe {{ 357 // Invokes `drop()` on `__MOD`, which should be used for cleanup. 358 __MOD.assume_init_drop(); 359 }} 360 }} 361 362 {modinfo} 363 }} 364 }} 365 ", 366 type_ = info.type_, 367 name = info.name, 368 modinfo = modinfo.buffer, 369 initcall_section = ".initcall6.init" 370 ) 371 .parse() 372 .expect("Error parsing formatted string into token stream.") 373 } 374