378 lines · rust
1// SPDX-License-Identifier: GPL-2.02 3use crate::helpers::*;4use proc_macro::{token_stream, Delimiter, Literal, TokenStream, TokenTree};5use std::fmt::Write;6 7fn 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 values23}24 25struct ModInfoBuilder<'a> {26 module: &'a str,27 counter: usize,28 buffer: String,29}30 31impl<'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 = content48 )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)]93struct 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 103impl 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 key130 );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_KEYS146 ),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_keys173 );174 }175 176 info177 }178}179 180pub(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 be217 // 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_};235 236 /// The \"Rust loadable module\" mark.237 //238 // This may be best done another way later on, e.g. as a new modinfo239 // key or a new section. For the moment, keep it simple.240 #[cfg(MODULE)]241 #[doc(hidden)]242 #[used]243 static __IS_RUST_MODULE: () = ();244 245 static mut __MOD: Option<{type_}> = None;246 247 // Loadable modules need to export the `{{init,cleanup}}_module` identifiers.248 /// # Safety249 ///250 /// This function must not be called after module initialization, because it may be251 /// freed after that completes.252 #[cfg(MODULE)]253 #[doc(hidden)]254 #[no_mangle]255 #[link_section = \".init.text\"]256 pub unsafe extern \"C\" fn init_module() -> core::ffi::c_int {{257 // SAFETY: This function is inaccessible to the outside due to the double258 // module wrapping it. It is called exactly once by the C side via its259 // unique name.260 unsafe {{ __init() }}261 }}262 263 #[cfg(MODULE)]264 #[doc(hidden)]265 #[used]266 #[link_section = \".init.data\"]267 static __UNIQUE_ID___addressable_init_module: unsafe extern \"C\" fn() -> i32 = init_module;268 269 #[cfg(MODULE)]270 #[doc(hidden)]271 #[no_mangle]272 pub extern \"C\" fn cleanup_module() {{273 // SAFETY:274 // - This function is inaccessible to the outside due to the double275 // module wrapping it. It is called exactly once by the C side via its276 // unique name,277 // - furthermore it is only called after `init_module` has returned `0`278 // (which delegates to `__init`).279 unsafe {{ __exit() }}280 }}281 282 #[cfg(MODULE)]283 #[doc(hidden)]284 #[used]285 #[link_section = \".exit.data\"]286 static __UNIQUE_ID___addressable_cleanup_module: extern \"C\" fn() = cleanup_module;287 288 // Built-in modules are initialized through an initcall pointer289 // and the identifiers need to be unique.290 #[cfg(not(MODULE))]291 #[cfg(not(CONFIG_HAVE_ARCH_PREL32_RELOCATIONS))]292 #[doc(hidden)]293 #[link_section = \"{initcall_section}\"]294 #[used]295 pub static __{name}_initcall: extern \"C\" fn() -> core::ffi::c_int = __{name}_init;296 297 #[cfg(not(MODULE))]298 #[cfg(CONFIG_HAVE_ARCH_PREL32_RELOCATIONS)]299 core::arch::global_asm!(300 r#\".section \"{initcall_section}\", \"a\"301 __{name}_initcall:302 .long __{name}_init - .303 .previous304 \"#305 );306 307 #[cfg(not(MODULE))]308 #[doc(hidden)]309 #[no_mangle]310 pub extern \"C\" fn __{name}_init() -> core::ffi::c_int {{311 // SAFETY: This function is inaccessible to the outside due to the double312 // module wrapping it. It is called exactly once by the C side via its313 // placement above in the initcall section.314 unsafe {{ __init() }}315 }}316 317 #[cfg(not(MODULE))]318 #[doc(hidden)]319 #[no_mangle]320 pub extern \"C\" fn __{name}_exit() {{321 // SAFETY:322 // - This function is inaccessible to the outside due to the double323 // module wrapping it. It is called exactly once by the C side via its324 // unique name,325 // - furthermore it is only called after `__{name}_init` has returned `0`326 // (which delegates to `__init`).327 unsafe {{ __exit() }}328 }}329 330 /// # Safety331 ///332 /// This function must only be called once.333 unsafe fn __init() -> core::ffi::c_int {{334 match <{type_} as kernel::Module>::init(&super::super::THIS_MODULE) {{335 Ok(m) => {{336 // SAFETY: No data race, since `__MOD` can only be accessed by this337 // module and there only `__init` and `__exit` access it. These338 // functions are only called once and `__exit` cannot be called339 // before or during `__init`.340 unsafe {{341 __MOD = Some(m);342 }}343 return 0;344 }}345 Err(e) => {{346 return e.to_errno();347 }}348 }}349 }}350 351 /// # Safety352 ///353 /// This function must354 /// - only be called once,355 /// - be called after `__init` has been called and returned `0`.356 unsafe fn __exit() {{357 // SAFETY: No data race, since `__MOD` can only be accessed by this module358 // and there only `__init` and `__exit` access it. These functions are only359 // called once and `__init` was already called.360 unsafe {{361 // Invokes `drop()` on `__MOD`, which should be used for cleanup.362 __MOD = None;363 }}364 }}365 366 {modinfo}367 }}368 }}369 ",370 type_ = info.type_,371 name = info.name,372 modinfo = modinfo.buffer,373 initcall_section = ".initcall6.init"374 )375 .parse()376 .expect("Error parsing formatted string into token stream.")377}378