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
expect_string_array(it: &mut token_stream::IntoIter) -> Vec<String>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> {
new(module: &'a str) -> Self32 fn new(module: &'a str) -> Self {
33 ModInfoBuilder {
34 module,
35 counter: 0,
36 buffer: String::new(),
37 }
38 }
39
emit_base(&mut self, field: &str, content: &str, builtin: bool)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(compiler)]
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
emit_only_builtin(&mut self, field: &str, content: &str)78 fn emit_only_builtin(&mut self, field: &str, content: &str) {
79 self.emit_base(field, content, true)
80 }
81
emit_only_loadable(&mut self, field: &str, content: &str)82 fn emit_only_loadable(&mut self, field: &str, content: &str) {
83 self.emit_base(field, content, false)
84 }
85
emit(&mut self, field: &str, content: &str)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 authors: Option<Vec<String>>,
98 description: Option<String>,
99 alias: Option<Vec<String>>,
100 firmware: Option<Vec<String>>,
101 }
102
103 impl ModuleInfo {
parse(it: &mut token_stream::IntoIter) -> Self104 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 "authors",
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!("Duplicated key \"{key}\". Keys can only be specified once.");
128 }
129
130 assert_eq!(expect_punct(it), ':');
131
132 match key.as_str() {
133 "type" => info.type_ = expect_ident(it),
134 "name" => info.name = expect_string_ascii(it),
135 "authors" => info.authors = Some(expect_string_array(it)),
136 "description" => info.description = Some(expect_string(it)),
137 "license" => info.license = expect_string_ascii(it),
138 "alias" => info.alias = Some(expect_string_array(it)),
139 "firmware" => info.firmware = Some(expect_string_array(it)),
140 _ => panic!("Unknown key \"{key}\". Valid keys are: {EXPECTED_KEYS:?}."),
141 }
142
143 assert_eq!(expect_punct(it), ',');
144
145 seen_keys.push(key);
146 }
147
148 expect_end(it);
149
150 for key in REQUIRED_KEYS {
151 if !seen_keys.iter().any(|e| e == key) {
152 panic!("Missing required key \"{key}\".");
153 }
154 }
155
156 let mut ordered_keys: Vec<&str> = Vec::new();
157 for key in EXPECTED_KEYS {
158 if seen_keys.iter().any(|e| e == key) {
159 ordered_keys.push(key);
160 }
161 }
162
163 if seen_keys != ordered_keys {
164 panic!("Keys are not ordered as expected. Order them like: {ordered_keys:?}.");
165 }
166
167 info
168 }
169 }
170
module(ts: TokenStream) -> TokenStream171 pub(crate) fn module(ts: TokenStream) -> TokenStream {
172 let mut it = ts.into_iter();
173
174 let info = ModuleInfo::parse(&mut it);
175
176 // Rust does not allow hyphens in identifiers, use underscore instead.
177 let ident = info.name.replace('-', "_");
178 let mut modinfo = ModInfoBuilder::new(ident.as_ref());
179 if let Some(authors) = info.authors {
180 for author in authors {
181 modinfo.emit("author", &author);
182 }
183 }
184 if let Some(description) = info.description {
185 modinfo.emit("description", &description);
186 }
187 modinfo.emit("license", &info.license);
188 if let Some(aliases) = info.alias {
189 for alias in aliases {
190 modinfo.emit("alias", &alias);
191 }
192 }
193 if let Some(firmware) = info.firmware {
194 for fw in firmware {
195 modinfo.emit("firmware", &fw);
196 }
197 }
198
199 // Built-in modules also export the `file` modinfo string.
200 let file =
201 std::env::var("RUST_MODFILE").expect("Unable to fetch RUST_MODFILE environmental variable");
202 modinfo.emit_only_builtin("file", &file);
203
204 format!(
205 "
206 /// The module name.
207 ///
208 /// Used by the printing macros, e.g. [`info!`].
209 const __LOG_PREFIX: &[u8] = b\"{name}\\0\";
210
211 // SAFETY: `__this_module` is constructed by the kernel at load time and will not be
212 // freed until the module is unloaded.
213 #[cfg(MODULE)]
214 static THIS_MODULE: ::kernel::ThisModule = unsafe {{
215 extern \"C\" {{
216 static __this_module: ::kernel::types::Opaque<::kernel::bindings::module>;
217 }}
218
219 ::kernel::ThisModule::from_ptr(__this_module.get())
220 }};
221 #[cfg(not(MODULE))]
222 static THIS_MODULE: ::kernel::ThisModule = unsafe {{
223 ::kernel::ThisModule::from_ptr(::core::ptr::null_mut())
224 }};
225
226 /// The `LocalModule` type is the type of the module created by `module!`,
227 /// `module_pci_driver!`, `module_platform_driver!`, etc.
228 type LocalModule = {type_};
229
230 impl ::kernel::ModuleMetadata for {type_} {{
231 const NAME: &'static ::kernel::str::CStr = ::kernel::c_str!(\"{name}\");
232 }}
233
234 // Double nested modules, since then nobody can access the public items inside.
235 mod __module_init {{
236 mod __module_init {{
237 use super::super::{type_};
238 use pin_init::PinInit;
239
240 /// The \"Rust loadable module\" mark.
241 //
242 // This may be best done another way later on, e.g. as a new modinfo
243 // key or a new section. For the moment, keep it simple.
244 #[cfg(MODULE)]
245 #[doc(hidden)]
246 #[used(compiler)]
247 static __IS_RUST_MODULE: () = ();
248
249 static mut __MOD: ::core::mem::MaybeUninit<{type_}> =
250 ::core::mem::MaybeUninit::uninit();
251
252 // Loadable modules need to export the `{{init,cleanup}}_module` identifiers.
253 /// # Safety
254 ///
255 /// This function must not be called after module initialization, because it may be
256 /// freed after that completes.
257 #[cfg(MODULE)]
258 #[doc(hidden)]
259 #[no_mangle]
260 #[link_section = \".init.text\"]
261 pub unsafe extern \"C\" fn init_module() -> ::kernel::ffi::c_int {{
262 // SAFETY: This function is inaccessible to the outside due to the double
263 // module wrapping it. It is called exactly once by the C side via its
264 // unique name.
265 unsafe {{ __init() }}
266 }}
267
268 #[cfg(MODULE)]
269 #[doc(hidden)]
270 #[used(compiler)]
271 #[link_section = \".init.data\"]
272 static __UNIQUE_ID___addressable_init_module: unsafe extern \"C\" fn() -> i32 = init_module;
273
274 #[cfg(MODULE)]
275 #[doc(hidden)]
276 #[no_mangle]
277 #[link_section = \".exit.text\"]
278 pub extern \"C\" fn cleanup_module() {{
279 // SAFETY:
280 // - This function is inaccessible to the outside due to the double
281 // module wrapping it. It is called exactly once by the C side via its
282 // unique name,
283 // - furthermore it is only called after `init_module` has returned `0`
284 // (which delegates to `__init`).
285 unsafe {{ __exit() }}
286 }}
287
288 #[cfg(MODULE)]
289 #[doc(hidden)]
290 #[used(compiler)]
291 #[link_section = \".exit.data\"]
292 static __UNIQUE_ID___addressable_cleanup_module: extern \"C\" fn() = cleanup_module;
293
294 // Built-in modules are initialized through an initcall pointer
295 // and the identifiers need to be unique.
296 #[cfg(not(MODULE))]
297 #[cfg(not(CONFIG_HAVE_ARCH_PREL32_RELOCATIONS))]
298 #[doc(hidden)]
299 #[link_section = \"{initcall_section}\"]
300 #[used(compiler)]
301 pub static __{ident}_initcall: extern \"C\" fn() ->
302 ::kernel::ffi::c_int = __{ident}_init;
303
304 #[cfg(not(MODULE))]
305 #[cfg(CONFIG_HAVE_ARCH_PREL32_RELOCATIONS)]
306 ::core::arch::global_asm!(
307 r#\".section \"{initcall_section}\", \"a\"
308 __{ident}_initcall:
309 .long __{ident}_init - .
310 .previous
311 \"#
312 );
313
314 #[cfg(not(MODULE))]
315 #[doc(hidden)]
316 #[no_mangle]
317 pub extern \"C\" fn __{ident}_init() -> ::kernel::ffi::c_int {{
318 // SAFETY: This function is inaccessible to the outside due to the double
319 // module wrapping it. It is called exactly once by the C side via its
320 // placement above in the initcall section.
321 unsafe {{ __init() }}
322 }}
323
324 #[cfg(not(MODULE))]
325 #[doc(hidden)]
326 #[no_mangle]
327 pub extern \"C\" fn __{ident}_exit() {{
328 // SAFETY:
329 // - This function is inaccessible to the outside due to the double
330 // module wrapping it. It is called exactly once by the C side via its
331 // unique name,
332 // - furthermore it is only called after `__{ident}_init` has
333 // returned `0` (which delegates to `__init`).
334 unsafe {{ __exit() }}
335 }}
336
337 /// # Safety
338 ///
339 /// This function must only be called once.
340 unsafe fn __init() -> ::kernel::ffi::c_int {{
341 let initer =
342 <{type_} as ::kernel::InPlaceModule>::init(&super::super::THIS_MODULE);
343 // SAFETY: No data race, since `__MOD` can only be accessed by this module
344 // and there only `__init` and `__exit` access it. These functions are only
345 // called once and `__exit` cannot be called before or during `__init`.
346 match unsafe {{ initer.__pinned_init(__MOD.as_mut_ptr()) }} {{
347 Ok(m) => 0,
348 Err(e) => e.to_errno(),
349 }}
350 }}
351
352 /// # Safety
353 ///
354 /// This function must
355 /// - only be called once,
356 /// - be called after `__init` has been called and returned `0`.
357 unsafe fn __exit() {{
358 // SAFETY: No data race, since `__MOD` can only be accessed by this module
359 // and there only `__init` and `__exit` access it. These functions are only
360 // called once and `__init` was already called.
361 unsafe {{
362 // Invokes `drop()` on `__MOD`, which should be used for cleanup.
363 __MOD.assume_init_drop();
364 }}
365 }}
366
367 {modinfo}
368 }}
369 }}
370 ",
371 type_ = info.type_,
372 name = info.name,
373 ident = ident,
374 modinfo = modinfo.buffer,
375 initcall_section = ".initcall6.init"
376 )
377 .parse()
378 .expect("Error parsing formatted string into token stream.")
379 }
380