1 // SPDX-License-Identifier: GPL-2.0 2 3 use crate::helpers::*; 4 use proc_macro::{token_stream, Literal, TokenStream, TokenTree}; 5 use std::fmt::Write; 6 7 struct ModInfoBuilder<'a> { 8 module: &'a str, 9 counter: usize, 10 buffer: String, 11 } 12 13 impl<'a> ModInfoBuilder<'a> { 14 fn new(module: &'a str) -> Self { 15 ModInfoBuilder { 16 module, 17 counter: 0, 18 buffer: String::new(), 19 } 20 } 21 22 fn emit_base(&mut self, field: &str, content: &str, builtin: bool) { 23 let string = if builtin { 24 // Built-in modules prefix their modinfo strings by `module.`. 25 format!( 26 "{module}.{field}={content}\0", 27 module = self.module, 28 field = field, 29 content = content 30 ) 31 } else { 32 // Loadable modules' modinfo strings go as-is. 33 format!("{field}={content}\0", field = field, content = content) 34 }; 35 36 write!( 37 &mut self.buffer, 38 " 39 {cfg} 40 #[doc(hidden)] 41 #[link_section = \".modinfo\"] 42 #[used] 43 pub static __{module}_{counter}: [u8; {length}] = *{string}; 44 ", 45 cfg = if builtin { 46 "#[cfg(not(MODULE))]" 47 } else { 48 "#[cfg(MODULE)]" 49 }, 50 module = self.module.to_uppercase(), 51 counter = self.counter, 52 length = string.len(), 53 string = Literal::byte_string(string.as_bytes()), 54 ) 55 .unwrap(); 56 57 self.counter += 1; 58 } 59 60 fn emit_only_builtin(&mut self, field: &str, content: &str) { 61 self.emit_base(field, content, true) 62 } 63 64 fn emit_only_loadable(&mut self, field: &str, content: &str) { 65 self.emit_base(field, content, false) 66 } 67 68 fn emit(&mut self, field: &str, content: &str) { 69 self.emit_only_builtin(field, content); 70 self.emit_only_loadable(field, content); 71 } 72 } 73 74 #[derive(Debug, Default)] 75 struct ModuleInfo { 76 type_: String, 77 license: String, 78 name: String, 79 author: Option<String>, 80 description: Option<String>, 81 alias: Option<String>, 82 } 83 84 impl ModuleInfo { 85 fn parse(it: &mut token_stream::IntoIter) -> Self { 86 let mut info = ModuleInfo::default(); 87 88 const EXPECTED_KEYS: &[&str] = 89 &["type", "name", "author", "description", "license", "alias"]; 90 const REQUIRED_KEYS: &[&str] = &["type", "name", "license"]; 91 let mut seen_keys = Vec::new(); 92 93 loop { 94 let key = match it.next() { 95 Some(TokenTree::Ident(ident)) => ident.to_string(), 96 Some(_) => panic!("Expected Ident or end"), 97 None => break, 98 }; 99 100 if seen_keys.contains(&key) { 101 panic!( 102 "Duplicated key \"{}\". Keys can only be specified once.", 103 key 104 ); 105 } 106 107 assert_eq!(expect_punct(it), ':'); 108 109 match key.as_str() { 110 "type" => info.type_ = expect_ident(it), 111 "name" => info.name = expect_string_ascii(it), 112 "author" => info.author = Some(expect_string(it)), 113 "description" => info.description = Some(expect_string(it)), 114 "license" => info.license = expect_string_ascii(it), 115 "alias" => info.alias = Some(expect_string_ascii(it)), 116 _ => panic!( 117 "Unknown key \"{}\". Valid keys are: {:?}.", 118 key, EXPECTED_KEYS 119 ), 120 } 121 122 assert_eq!(expect_punct(it), ','); 123 124 seen_keys.push(key); 125 } 126 127 expect_end(it); 128 129 for key in REQUIRED_KEYS { 130 if !seen_keys.iter().any(|e| e == key) { 131 panic!("Missing required key \"{}\".", key); 132 } 133 } 134 135 let mut ordered_keys: Vec<&str> = Vec::new(); 136 for key in EXPECTED_KEYS { 137 if seen_keys.iter().any(|e| e == key) { 138 ordered_keys.push(key); 139 } 140 } 141 142 if seen_keys != ordered_keys { 143 panic!( 144 "Keys are not ordered as expected. Order them like: {:?}.", 145 ordered_keys 146 ); 147 } 148 149 info 150 } 151 } 152 153 pub(crate) fn module(ts: TokenStream) -> TokenStream { 154 let mut it = ts.into_iter(); 155 156 let info = ModuleInfo::parse(&mut it); 157 158 let mut modinfo = ModInfoBuilder::new(info.name.as_ref()); 159 if let Some(author) = info.author { 160 modinfo.emit("author", &author); 161 } 162 if let Some(description) = info.description { 163 modinfo.emit("description", &description); 164 } 165 modinfo.emit("license", &info.license); 166 if let Some(alias) = info.alias { 167 modinfo.emit("alias", &alias); 168 } 169 170 // Built-in modules also export the `file` modinfo string. 171 let file = 172 std::env::var("RUST_MODFILE").expect("Unable to fetch RUST_MODFILE environmental variable"); 173 modinfo.emit_only_builtin("file", &file); 174 175 format!( 176 " 177 /// The module name. 178 /// 179 /// Used by the printing macros, e.g. [`info!`]. 180 const __LOG_PREFIX: &[u8] = b\"{name}\\0\"; 181 182 /// The \"Rust loadable module\" mark, for `scripts/is_rust_module.sh`. 183 // 184 // This may be best done another way later on, e.g. as a new modinfo 185 // key or a new section. For the moment, keep it simple. 186 #[cfg(MODULE)] 187 #[doc(hidden)] 188 #[used] 189 static __IS_RUST_MODULE: () = (); 190 191 static mut __MOD: Option<{type_}> = None; 192 193 // SAFETY: `__this_module` is constructed by the kernel at load time and will not be 194 // freed until the module is unloaded. 195 #[cfg(MODULE)] 196 static THIS_MODULE: kernel::ThisModule = unsafe {{ 197 kernel::ThisModule::from_ptr(&kernel::bindings::__this_module as *const _ as *mut _) 198 }}; 199 #[cfg(not(MODULE))] 200 static THIS_MODULE: kernel::ThisModule = unsafe {{ 201 kernel::ThisModule::from_ptr(core::ptr::null_mut()) 202 }}; 203 204 // Loadable modules need to export the `{{init,cleanup}}_module` identifiers. 205 #[cfg(MODULE)] 206 #[doc(hidden)] 207 #[no_mangle] 208 pub extern \"C\" fn init_module() -> core::ffi::c_int {{ 209 __init() 210 }} 211 212 #[cfg(MODULE)] 213 #[doc(hidden)] 214 #[no_mangle] 215 pub extern \"C\" fn cleanup_module() {{ 216 __exit() 217 }} 218 219 // Built-in modules are initialized through an initcall pointer 220 // and the identifiers need to be unique. 221 #[cfg(not(MODULE))] 222 #[cfg(not(CONFIG_HAVE_ARCH_PREL32_RELOCATIONS))] 223 #[doc(hidden)] 224 #[link_section = \"{initcall_section}\"] 225 #[used] 226 pub static __{name}_initcall: extern \"C\" fn() -> core::ffi::c_int = __{name}_init; 227 228 #[cfg(not(MODULE))] 229 #[cfg(CONFIG_HAVE_ARCH_PREL32_RELOCATIONS)] 230 core::arch::global_asm!( 231 r#\".section \"{initcall_section}\", \"a\" 232 __{name}_initcall: 233 .long __{name}_init - . 234 .previous 235 \"# 236 ); 237 238 #[cfg(not(MODULE))] 239 #[doc(hidden)] 240 #[no_mangle] 241 pub extern \"C\" fn __{name}_init() -> core::ffi::c_int {{ 242 __init() 243 }} 244 245 #[cfg(not(MODULE))] 246 #[doc(hidden)] 247 #[no_mangle] 248 pub extern \"C\" fn __{name}_exit() {{ 249 __exit() 250 }} 251 252 fn __init() -> core::ffi::c_int {{ 253 match <{type_} as kernel::Module>::init(&THIS_MODULE) {{ 254 Ok(m) => {{ 255 unsafe {{ 256 __MOD = Some(m); 257 }} 258 return 0; 259 }} 260 Err(e) => {{ 261 return e.to_kernel_errno(); 262 }} 263 }} 264 }} 265 266 fn __exit() {{ 267 unsafe {{ 268 // Invokes `drop()` on `__MOD`, which should be used for cleanup. 269 __MOD = None; 270 }} 271 }} 272 273 {modinfo} 274 ", 275 type_ = info.type_, 276 name = info.name, 277 modinfo = modinfo.buffer, 278 initcall_section = ".initcall6.init" 279 ) 280 .parse() 281 .expect("Error parsing formatted string into token stream.") 282 } 283