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]
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 author: Option<String>,
98 authors: Option<Vec<String>>,
99 description: Option<String>,
100 alias: Option<Vec<String>>,
101 firmware: Option<Vec<String>>,
102 }
103
104 impl ModuleInfo {
parse(it: &mut token_stream::IntoIter) -> Self105 fn parse(it: &mut token_stream::IntoIter) -> Self {
106 let mut info = ModuleInfo::default();
107
108 const EXPECTED_KEYS: &[&str] = &[
109 "type",
110 "name",
111 "author",
112 "authors",
113 "description",
114 "license",
115 "alias",
116 "firmware",
117 ];
118 const REQUIRED_KEYS: &[&str] = &["type", "name", "license"];
119 let mut seen_keys = Vec::new();
120
121 loop {
122 let key = match it.next() {
123 Some(TokenTree::Ident(ident)) => ident.to_string(),
124 Some(_) => panic!("Expected Ident or end"),
125 None => break,
126 };
127
128 if seen_keys.contains(&key) {
129 panic!("Duplicated key \"{key}\". Keys can only be specified once.");
130 }
131
132 assert_eq!(expect_punct(it), ':');
133
134 match key.as_str() {
135 "type" => info.type_ = expect_ident(it),
136 "name" => info.name = expect_string_ascii(it),
137 "author" => info.author = Some(expect_string(it)),
138 "authors" => info.authors = Some(expect_string_array(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!("Unknown key \"{key}\". Valid keys are: {EXPECTED_KEYS:?}."),
144 }
145
146 assert_eq!(expect_punct(it), ',');
147
148 seen_keys.push(key);
149 }
150
151 expect_end(it);
152
153 for key in REQUIRED_KEYS {
154 if !seen_keys.iter().any(|e| e == key) {
155 panic!("Missing required key \"{key}\".");
156 }
157 }
158
159 let mut ordered_keys: Vec<&str> = Vec::new();
160 for key in EXPECTED_KEYS {
161 if seen_keys.iter().any(|e| e == key) {
162 ordered_keys.push(key);
163 }
164 }
165
166 if seen_keys != ordered_keys {
167 panic!("Keys are not ordered as expected. Order them like: {ordered_keys:?}.");
168 }
169
170 info
171 }
172 }
173
module(ts: TokenStream) -> TokenStream174 pub(crate) fn module(ts: TokenStream) -> TokenStream {
175 let mut it = ts.into_iter();
176
177 let info = ModuleInfo::parse(&mut it);
178
179 // Rust does not allow hyphens in identifiers, use underscore instead.
180 let ident = info.name.replace('-', "_");
181 let mut modinfo = ModInfoBuilder::new(ident.as_ref());
182 if let Some(author) = info.author {
183 modinfo.emit("author", &author);
184 }
185 if let Some(authors) = info.authors {
186 for author in authors {
187 modinfo.emit("author", &author);
188 }
189 }
190 if let Some(description) = info.description {
191 modinfo.emit("description", &description);
192 }
193 modinfo.emit("license", &info.license);
194 if let Some(aliases) = info.alias {
195 for alias in aliases {
196 modinfo.emit("alias", &alias);
197 }
198 }
199 if let Some(firmware) = info.firmware {
200 for fw in firmware {
201 modinfo.emit("firmware", &fw);
202 }
203 }
204
205 // Built-in modules also export the `file` modinfo string.
206 let file =
207 std::env::var("RUST_MODFILE").expect("Unable to fetch RUST_MODFILE environmental variable");
208 modinfo.emit_only_builtin("file", &file);
209
210 format!(
211 "
212 /// The module name.
213 ///
214 /// Used by the printing macros, e.g. [`info!`].
215 const __LOG_PREFIX: &[u8] = b\"{name}\\0\";
216
217 // SAFETY: `__this_module` is constructed by the kernel at load time and will not be
218 // freed until the module is unloaded.
219 #[cfg(MODULE)]
220 static THIS_MODULE: ::kernel::ThisModule = unsafe {{
221 extern \"C\" {{
222 static __this_module: ::kernel::types::Opaque<::kernel::bindings::module>;
223 }}
224
225 ::kernel::ThisModule::from_ptr(__this_module.get())
226 }};
227 #[cfg(not(MODULE))]
228 static THIS_MODULE: ::kernel::ThisModule = unsafe {{
229 ::kernel::ThisModule::from_ptr(::core::ptr::null_mut())
230 }};
231
232 /// The `LocalModule` type is the type of the module created by `module!`,
233 /// `module_pci_driver!`, `module_platform_driver!`, etc.
234 type LocalModule = {type_};
235
236 impl ::kernel::ModuleMetadata for {type_} {{
237 const NAME: &'static ::kernel::str::CStr = ::kernel::c_str!(\"{name}\");
238 }}
239
240 // Double nested modules, since then nobody can access the public items inside.
241 mod __module_init {{
242 mod __module_init {{
243 use super::super::{type_};
244 use pin_init::PinInit;
245
246 /// The \"Rust loadable module\" mark.
247 //
248 // This may be best done another way later on, e.g. as a new modinfo
249 // key or a new section. For the moment, keep it simple.
250 #[cfg(MODULE)]
251 #[doc(hidden)]
252 #[used]
253 static __IS_RUST_MODULE: () = ();
254
255 static mut __MOD: ::core::mem::MaybeUninit<{type_}> =
256 ::core::mem::MaybeUninit::uninit();
257
258 // Loadable modules need to export the `{{init,cleanup}}_module` identifiers.
259 /// # Safety
260 ///
261 /// This function must not be called after module initialization, because it may be
262 /// freed after that completes.
263 #[cfg(MODULE)]
264 #[doc(hidden)]
265 #[no_mangle]
266 #[link_section = \".init.text\"]
267 pub unsafe extern \"C\" fn init_module() -> ::kernel::ffi::c_int {{
268 // SAFETY: This function is inaccessible to the outside due to the double
269 // module wrapping it. It is called exactly once by the C side via its
270 // unique name.
271 unsafe {{ __init() }}
272 }}
273
274 #[cfg(MODULE)]
275 #[doc(hidden)]
276 #[used]
277 #[link_section = \".init.data\"]
278 static __UNIQUE_ID___addressable_init_module: unsafe extern \"C\" fn() -> i32 = init_module;
279
280 #[cfg(MODULE)]
281 #[doc(hidden)]
282 #[no_mangle]
283 #[link_section = \".exit.text\"]
284 pub extern \"C\" fn cleanup_module() {{
285 // SAFETY:
286 // - This function is inaccessible to the outside due to the double
287 // module wrapping it. It is called exactly once by the C side via its
288 // unique name,
289 // - furthermore it is only called after `init_module` has returned `0`
290 // (which delegates to `__init`).
291 unsafe {{ __exit() }}
292 }}
293
294 #[cfg(MODULE)]
295 #[doc(hidden)]
296 #[used]
297 #[link_section = \".exit.data\"]
298 static __UNIQUE_ID___addressable_cleanup_module: extern \"C\" fn() = cleanup_module;
299
300 // Built-in modules are initialized through an initcall pointer
301 // and the identifiers need to be unique.
302 #[cfg(not(MODULE))]
303 #[cfg(not(CONFIG_HAVE_ARCH_PREL32_RELOCATIONS))]
304 #[doc(hidden)]
305 #[link_section = \"{initcall_section}\"]
306 #[used]
307 pub static __{ident}_initcall: extern \"C\" fn() ->
308 ::kernel::ffi::c_int = __{ident}_init;
309
310 #[cfg(not(MODULE))]
311 #[cfg(CONFIG_HAVE_ARCH_PREL32_RELOCATIONS)]
312 ::core::arch::global_asm!(
313 r#\".section \"{initcall_section}\", \"a\"
314 __{ident}_initcall:
315 .long __{ident}_init - .
316 .previous
317 \"#
318 );
319
320 #[cfg(not(MODULE))]
321 #[doc(hidden)]
322 #[no_mangle]
323 pub extern \"C\" fn __{ident}_init() -> ::kernel::ffi::c_int {{
324 // SAFETY: 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 // placement above in the initcall section.
327 unsafe {{ __init() }}
328 }}
329
330 #[cfg(not(MODULE))]
331 #[doc(hidden)]
332 #[no_mangle]
333 pub extern \"C\" fn __{ident}_exit() {{
334 // SAFETY:
335 // - This function is inaccessible to the outside due to the double
336 // module wrapping it. It is called exactly once by the C side via its
337 // unique name,
338 // - furthermore it is only called after `__{ident}_init` has
339 // returned `0` (which delegates to `__init`).
340 unsafe {{ __exit() }}
341 }}
342
343 /// # Safety
344 ///
345 /// This function must only be called once.
346 unsafe fn __init() -> ::kernel::ffi::c_int {{
347 let initer =
348 <{type_} as ::kernel::InPlaceModule>::init(&super::super::THIS_MODULE);
349 // SAFETY: No data race, since `__MOD` can only be accessed by this module
350 // and there only `__init` and `__exit` access it. These functions are only
351 // called once and `__exit` cannot be called before or during `__init`.
352 match unsafe {{ initer.__pinned_init(__MOD.as_mut_ptr()) }} {{
353 Ok(m) => 0,
354 Err(e) => e.to_errno(),
355 }}
356 }}
357
358 /// # Safety
359 ///
360 /// This function must
361 /// - only be called once,
362 /// - be called after `__init` has been called and returned `0`.
363 unsafe fn __exit() {{
364 // SAFETY: No data race, since `__MOD` can only be accessed by this module
365 // and there only `__init` and `__exit` access it. These functions are only
366 // called once and `__init` was already called.
367 unsafe {{
368 // Invokes `drop()` on `__MOD`, which should be used for cleanup.
369 __MOD.assume_init_drop();
370 }}
371 }}
372
373 {modinfo}
374 }}
375 }}
376 ",
377 type_ = info.type_,
378 name = info.name,
379 ident = ident,
380 modinfo = modinfo.buffer,
381 initcall_section = ".initcall6.init"
382 )
383 .parse()
384 .expect("Error parsing formatted string into token stream.")
385 }
386