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 } 101 102 impl ModuleInfo { 103 fn parse(it: &mut token_stream::IntoIter) -> Self { 104 let mut info = ModuleInfo::default(); 105 106 const EXPECTED_KEYS: &[&str] = 107 &["type", "name", "author", "description", "license", "alias"]; 108 const REQUIRED_KEYS: &[&str] = &["type", "name", "license"]; 109 let mut seen_keys = Vec::new(); 110 111 loop { 112 let key = match it.next() { 113 Some(TokenTree::Ident(ident)) => ident.to_string(), 114 Some(_) => panic!("Expected Ident or end"), 115 None => break, 116 }; 117 118 if seen_keys.contains(&key) { 119 panic!( 120 "Duplicated key \"{}\". Keys can only be specified once.", 121 key 122 ); 123 } 124 125 assert_eq!(expect_punct(it), ':'); 126 127 match key.as_str() { 128 "type" => info.type_ = expect_ident(it), 129 "name" => info.name = expect_string_ascii(it), 130 "author" => info.author = Some(expect_string(it)), 131 "description" => info.description = Some(expect_string(it)), 132 "license" => info.license = expect_string_ascii(it), 133 "alias" => info.alias = Some(expect_string_array(it)), 134 _ => panic!( 135 "Unknown key \"{}\". Valid keys are: {:?}.", 136 key, EXPECTED_KEYS 137 ), 138 } 139 140 assert_eq!(expect_punct(it), ','); 141 142 seen_keys.push(key); 143 } 144 145 expect_end(it); 146 147 for key in REQUIRED_KEYS { 148 if !seen_keys.iter().any(|e| e == key) { 149 panic!("Missing required key \"{}\".", key); 150 } 151 } 152 153 let mut ordered_keys: Vec<&str> = Vec::new(); 154 for key in EXPECTED_KEYS { 155 if seen_keys.iter().any(|e| e == key) { 156 ordered_keys.push(key); 157 } 158 } 159 160 if seen_keys != ordered_keys { 161 panic!( 162 "Keys are not ordered as expected. Order them like: {:?}.", 163 ordered_keys 164 ); 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 let mut modinfo = ModInfoBuilder::new(info.name.as_ref()); 177 if let Some(author) = info.author { 178 modinfo.emit("author", &author); 179 } 180 if let Some(description) = info.description { 181 modinfo.emit("description", &description); 182 } 183 modinfo.emit("license", &info.license); 184 if let Some(aliases) = info.alias { 185 for alias in aliases { 186 modinfo.emit("alias", &alias); 187 } 188 } 189 190 // Built-in modules also export the `file` modinfo string. 191 let file = 192 std::env::var("RUST_MODFILE").expect("Unable to fetch RUST_MODFILE environmental variable"); 193 modinfo.emit_only_builtin("file", &file); 194 195 format!( 196 " 197 /// The module name. 198 /// 199 /// Used by the printing macros, e.g. [`info!`]. 200 const __LOG_PREFIX: &[u8] = b\"{name}\\0\"; 201 202 /// The \"Rust loadable module\" mark, for `scripts/is_rust_module.sh`. 203 // 204 // This may be best done another way later on, e.g. as a new modinfo 205 // key or a new section. For the moment, keep it simple. 206 #[cfg(MODULE)] 207 #[doc(hidden)] 208 #[used] 209 static __IS_RUST_MODULE: () = (); 210 211 static mut __MOD: Option<{type_}> = None; 212 213 // SAFETY: `__this_module` is constructed by the kernel at load time and will not be 214 // freed until the module is unloaded. 215 #[cfg(MODULE)] 216 static THIS_MODULE: kernel::ThisModule = unsafe {{ 217 kernel::ThisModule::from_ptr(&kernel::bindings::__this_module as *const _ as *mut _) 218 }}; 219 #[cfg(not(MODULE))] 220 static THIS_MODULE: kernel::ThisModule = unsafe {{ 221 kernel::ThisModule::from_ptr(core::ptr::null_mut()) 222 }}; 223 224 // Loadable modules need to export the `{{init,cleanup}}_module` identifiers. 225 #[cfg(MODULE)] 226 #[doc(hidden)] 227 #[no_mangle] 228 pub extern \"C\" fn init_module() -> core::ffi::c_int {{ 229 __init() 230 }} 231 232 #[cfg(MODULE)] 233 #[doc(hidden)] 234 #[no_mangle] 235 pub extern \"C\" fn cleanup_module() {{ 236 __exit() 237 }} 238 239 // Built-in modules are initialized through an initcall pointer 240 // and the identifiers need to be unique. 241 #[cfg(not(MODULE))] 242 #[cfg(not(CONFIG_HAVE_ARCH_PREL32_RELOCATIONS))] 243 #[doc(hidden)] 244 #[link_section = \"{initcall_section}\"] 245 #[used] 246 pub static __{name}_initcall: extern \"C\" fn() -> core::ffi::c_int = __{name}_init; 247 248 #[cfg(not(MODULE))] 249 #[cfg(CONFIG_HAVE_ARCH_PREL32_RELOCATIONS)] 250 core::arch::global_asm!( 251 r#\".section \"{initcall_section}\", \"a\" 252 __{name}_initcall: 253 .long __{name}_init - . 254 .previous 255 \"# 256 ); 257 258 #[cfg(not(MODULE))] 259 #[doc(hidden)] 260 #[no_mangle] 261 pub extern \"C\" fn __{name}_init() -> core::ffi::c_int {{ 262 __init() 263 }} 264 265 #[cfg(not(MODULE))] 266 #[doc(hidden)] 267 #[no_mangle] 268 pub extern \"C\" fn __{name}_exit() {{ 269 __exit() 270 }} 271 272 fn __init() -> core::ffi::c_int {{ 273 match <{type_} as kernel::Module>::init(&THIS_MODULE) {{ 274 Ok(m) => {{ 275 unsafe {{ 276 __MOD = Some(m); 277 }} 278 return 0; 279 }} 280 Err(e) => {{ 281 return e.to_errno(); 282 }} 283 }} 284 }} 285 286 fn __exit() {{ 287 unsafe {{ 288 // Invokes `drop()` on `__MOD`, which should be used for cleanup. 289 __MOD = None; 290 }} 291 }} 292 293 {modinfo} 294 ", 295 type_ = info.type_, 296 name = info.name, 297 modinfo = modinfo.buffer, 298 initcall_section = ".initcall6.init" 299 ) 300 .parse() 301 .expect("Error parsing formatted string into token stream.") 302 } 303