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 param_buffer: String,
30 }
31
32 impl<'a> ModInfoBuilder<'a> {
new(module: &'a str) -> Self33 fn new(module: &'a str) -> Self {
34 ModInfoBuilder {
35 module,
36 counter: 0,
37 buffer: String::new(),
38 param_buffer: String::new(),
39 }
40 }
41
emit_base(&mut self, field: &str, content: &str, builtin: bool, param: bool)42 fn emit_base(&mut self, field: &str, content: &str, builtin: bool, param: bool) {
43 let string = if builtin {
44 // Built-in modules prefix their modinfo strings by `module.`.
45 format!(
46 "{module}.{field}={content}\0",
47 module = self.module,
48 field = field,
49 content = content
50 )
51 } else {
52 // Loadable modules' modinfo strings go as-is.
53 format!("{field}={content}\0")
54 };
55
56 let buffer = if param {
57 &mut self.param_buffer
58 } else {
59 &mut self.buffer
60 };
61
62 write!(
63 buffer,
64 "
65 {cfg}
66 #[doc(hidden)]
67 #[cfg_attr(not(target_os = \"macos\"), link_section = \".modinfo\")]
68 #[used(compiler)]
69 pub static __{module}_{counter}: [u8; {length}] = *{string};
70 ",
71 cfg = if builtin {
72 "#[cfg(not(MODULE))]"
73 } else {
74 "#[cfg(MODULE)]"
75 },
76 module = self.module.to_uppercase(),
77 counter = self.counter,
78 length = string.len(),
79 string = Literal::byte_string(string.as_bytes()),
80 )
81 .unwrap();
82
83 self.counter += 1;
84 }
85
emit_only_builtin(&mut self, field: &str, content: &str, param: bool)86 fn emit_only_builtin(&mut self, field: &str, content: &str, param: bool) {
87 self.emit_base(field, content, true, param)
88 }
89
emit_only_loadable(&mut self, field: &str, content: &str, param: bool)90 fn emit_only_loadable(&mut self, field: &str, content: &str, param: bool) {
91 self.emit_base(field, content, false, param)
92 }
93
emit(&mut self, field: &str, content: &str)94 fn emit(&mut self, field: &str, content: &str) {
95 self.emit_internal(field, content, false);
96 }
97
emit_internal(&mut self, field: &str, content: &str, param: bool)98 fn emit_internal(&mut self, field: &str, content: &str, param: bool) {
99 self.emit_only_builtin(field, content, param);
100 self.emit_only_loadable(field, content, param);
101 }
102
emit_param(&mut self, field: &str, param: &str, content: &str)103 fn emit_param(&mut self, field: &str, param: &str, content: &str) {
104 let content = format!("{param}:{content}", param = param, content = content);
105 self.emit_internal(field, &content, true);
106 }
107
emit_params(&mut self, info: &ModuleInfo)108 fn emit_params(&mut self, info: &ModuleInfo) {
109 let Some(params) = &info.params else {
110 return;
111 };
112
113 for param in params {
114 let ops = param_ops_path(¶m.ptype);
115
116 // Note: The spelling of these fields is dictated by the user space
117 // tool `modinfo`.
118 self.emit_param("parmtype", ¶m.name, ¶m.ptype);
119 self.emit_param("parm", ¶m.name, ¶m.description);
120
121 write!(
122 self.param_buffer,
123 "
124 pub(crate) static {param_name}:
125 ::kernel::module_param::ModuleParamAccess<{param_type}> =
126 ::kernel::module_param::ModuleParamAccess::new({param_default});
127
128 const _: () = {{
129 #[link_section = \"__param\"]
130 #[used]
131 static __{module_name}_{param_name}_struct:
132 ::kernel::module_param::KernelParam =
133 ::kernel::module_param::KernelParam::new(
134 ::kernel::bindings::kernel_param {{
135 name: if ::core::cfg!(MODULE) {{
136 ::kernel::c_str!(\"{param_name}\").to_bytes_with_nul()
137 }} else {{
138 ::kernel::c_str!(\"{module_name}.{param_name}\")
139 .to_bytes_with_nul()
140 }}.as_ptr(),
141 // SAFETY: `__this_module` is constructed by the kernel at load
142 // time and will not be freed until the module is unloaded.
143 #[cfg(MODULE)]
144 mod_: unsafe {{
145 core::ptr::from_ref(&::kernel::bindings::__this_module)
146 .cast_mut()
147 }},
148 #[cfg(not(MODULE))]
149 mod_: ::core::ptr::null_mut(),
150 ops: core::ptr::from_ref(&{ops}),
151 perm: 0, // Will not appear in sysfs
152 level: -1,
153 flags: 0,
154 __bindgen_anon_1: ::kernel::bindings::kernel_param__bindgen_ty_1 {{
155 arg: {param_name}.as_void_ptr()
156 }},
157 }}
158 );
159 }};
160 ",
161 module_name = info.name,
162 param_type = param.ptype,
163 param_default = param.default,
164 param_name = param.name,
165 ops = ops,
166 )
167 .unwrap();
168 }
169 }
170 }
171
param_ops_path(param_type: &str) -> &'static str172 fn param_ops_path(param_type: &str) -> &'static str {
173 match param_type {
174 "i8" => "::kernel::module_param::PARAM_OPS_I8",
175 "u8" => "::kernel::module_param::PARAM_OPS_U8",
176 "i16" => "::kernel::module_param::PARAM_OPS_I16",
177 "u16" => "::kernel::module_param::PARAM_OPS_U16",
178 "i32" => "::kernel::module_param::PARAM_OPS_I32",
179 "u32" => "::kernel::module_param::PARAM_OPS_U32",
180 "i64" => "::kernel::module_param::PARAM_OPS_I64",
181 "u64" => "::kernel::module_param::PARAM_OPS_U64",
182 "isize" => "::kernel::module_param::PARAM_OPS_ISIZE",
183 "usize" => "::kernel::module_param::PARAM_OPS_USIZE",
184 t => panic!("Unsupported parameter type {}", t),
185 }
186 }
187
expect_param_default(param_it: &mut token_stream::IntoIter) -> String188 fn expect_param_default(param_it: &mut token_stream::IntoIter) -> String {
189 assert_eq!(expect_ident(param_it), "default");
190 assert_eq!(expect_punct(param_it), ':');
191 let sign = try_sign(param_it);
192 let default = try_literal(param_it).expect("Expected default param value");
193 assert_eq!(expect_punct(param_it), ',');
194 let mut value = sign.map(String::from).unwrap_or_default();
195 value.push_str(&default);
196 value
197 }
198
199 #[derive(Debug, Default)]
200 struct ModuleInfo {
201 type_: String,
202 license: String,
203 name: String,
204 authors: Option<Vec<String>>,
205 description: Option<String>,
206 alias: Option<Vec<String>>,
207 firmware: Option<Vec<String>>,
208 imports_ns: Option<Vec<String>>,
209 params: Option<Vec<Parameter>>,
210 }
211
212 #[derive(Debug)]
213 struct Parameter {
214 name: String,
215 ptype: String,
216 default: String,
217 description: String,
218 }
219
expect_params(it: &mut token_stream::IntoIter) -> Vec<Parameter>220 fn expect_params(it: &mut token_stream::IntoIter) -> Vec<Parameter> {
221 let params = expect_group(it);
222 assert_eq!(params.delimiter(), Delimiter::Brace);
223 let mut it = params.stream().into_iter();
224 let mut parsed = Vec::new();
225
226 loop {
227 let param_name = match it.next() {
228 Some(TokenTree::Ident(ident)) => ident.to_string(),
229 Some(_) => panic!("Expected Ident or end"),
230 None => break,
231 };
232
233 assert_eq!(expect_punct(&mut it), ':');
234 let param_type = expect_ident(&mut it);
235 let group = expect_group(&mut it);
236 assert_eq!(group.delimiter(), Delimiter::Brace);
237 assert_eq!(expect_punct(&mut it), ',');
238
239 let mut param_it = group.stream().into_iter();
240 let param_default = expect_param_default(&mut param_it);
241 let param_description = expect_string_field(&mut param_it, "description");
242 expect_end(&mut param_it);
243
244 parsed.push(Parameter {
245 name: param_name,
246 ptype: param_type,
247 default: param_default,
248 description: param_description,
249 })
250 }
251
252 parsed
253 }
254
255 impl ModuleInfo {
parse(it: &mut token_stream::IntoIter) -> Self256 fn parse(it: &mut token_stream::IntoIter) -> Self {
257 let mut info = ModuleInfo::default();
258
259 const EXPECTED_KEYS: &[&str] = &[
260 "type",
261 "name",
262 "authors",
263 "description",
264 "license",
265 "alias",
266 "firmware",
267 "imports_ns",
268 "params",
269 ];
270 const REQUIRED_KEYS: &[&str] = &["type", "name", "license"];
271 let mut seen_keys = Vec::new();
272
273 loop {
274 let key = match it.next() {
275 Some(TokenTree::Ident(ident)) => ident.to_string(),
276 Some(_) => panic!("Expected Ident or end"),
277 None => break,
278 };
279
280 if seen_keys.contains(&key) {
281 panic!("Duplicated key \"{key}\". Keys can only be specified once.");
282 }
283
284 assert_eq!(expect_punct(it), ':');
285
286 match key.as_str() {
287 "type" => info.type_ = expect_ident(it),
288 "name" => info.name = expect_string_ascii(it),
289 "authors" => info.authors = Some(expect_string_array(it)),
290 "description" => info.description = Some(expect_string(it)),
291 "license" => info.license = expect_string_ascii(it),
292 "alias" => info.alias = Some(expect_string_array(it)),
293 "firmware" => info.firmware = Some(expect_string_array(it)),
294 "imports_ns" => info.imports_ns = Some(expect_string_array(it)),
295 "params" => info.params = Some(expect_params(it)),
296 _ => panic!("Unknown key \"{key}\". Valid keys are: {EXPECTED_KEYS:?}."),
297 }
298
299 assert_eq!(expect_punct(it), ',');
300
301 seen_keys.push(key);
302 }
303
304 expect_end(it);
305
306 for key in REQUIRED_KEYS {
307 if !seen_keys.iter().any(|e| e == key) {
308 panic!("Missing required key \"{key}\".");
309 }
310 }
311
312 let mut ordered_keys: Vec<&str> = Vec::new();
313 for key in EXPECTED_KEYS {
314 if seen_keys.iter().any(|e| e == key) {
315 ordered_keys.push(key);
316 }
317 }
318
319 if seen_keys != ordered_keys {
320 panic!("Keys are not ordered as expected. Order them like: {ordered_keys:?}.");
321 }
322
323 info
324 }
325 }
326
module(ts: TokenStream) -> TokenStream327 pub(crate) fn module(ts: TokenStream) -> TokenStream {
328 let mut it = ts.into_iter();
329
330 let info = ModuleInfo::parse(&mut it);
331
332 // Rust does not allow hyphens in identifiers, use underscore instead.
333 let ident = info.name.replace('-', "_");
334 let mut modinfo = ModInfoBuilder::new(ident.as_ref());
335 if let Some(authors) = &info.authors {
336 for author in authors {
337 modinfo.emit("author", author);
338 }
339 }
340 if let Some(description) = &info.description {
341 modinfo.emit("description", description);
342 }
343 modinfo.emit("license", &info.license);
344 if let Some(aliases) = &info.alias {
345 for alias in aliases {
346 modinfo.emit("alias", alias);
347 }
348 }
349 if let Some(firmware) = &info.firmware {
350 for fw in firmware {
351 modinfo.emit("firmware", fw);
352 }
353 }
354 if let Some(imports) = &info.imports_ns {
355 for ns in imports {
356 modinfo.emit("import_ns", ns);
357 }
358 }
359
360 // Built-in modules also export the `file` modinfo string.
361 let file =
362 std::env::var("RUST_MODFILE").expect("Unable to fetch RUST_MODFILE environmental variable");
363 modinfo.emit_only_builtin("file", &file, false);
364
365 modinfo.emit_params(&info);
366
367 format!(
368 "
369 /// The module name.
370 ///
371 /// Used by the printing macros, e.g. [`info!`].
372 const __LOG_PREFIX: &[u8] = b\"{name}\\0\";
373
374 // SAFETY: `__this_module` is constructed by the kernel at load time and will not be
375 // freed until the module is unloaded.
376 #[cfg(MODULE)]
377 static THIS_MODULE: ::kernel::ThisModule = unsafe {{
378 extern \"C\" {{
379 static __this_module: ::kernel::types::Opaque<::kernel::bindings::module>;
380 }}
381
382 ::kernel::ThisModule::from_ptr(__this_module.get())
383 }};
384 #[cfg(not(MODULE))]
385 static THIS_MODULE: ::kernel::ThisModule = unsafe {{
386 ::kernel::ThisModule::from_ptr(::core::ptr::null_mut())
387 }};
388
389 /// The `LocalModule` type is the type of the module created by `module!`,
390 /// `module_pci_driver!`, `module_platform_driver!`, etc.
391 type LocalModule = {type_};
392
393 impl ::kernel::ModuleMetadata for {type_} {{
394 const NAME: &'static ::kernel::str::CStr = c\"{name}\";
395 }}
396
397 // Double nested modules, since then nobody can access the public items inside.
398 mod __module_init {{
399 mod __module_init {{
400 use super::super::{type_};
401 use pin_init::PinInit;
402
403 /// The \"Rust loadable module\" mark.
404 //
405 // This may be best done another way later on, e.g. as a new modinfo
406 // key or a new section. For the moment, keep it simple.
407 #[cfg(MODULE)]
408 #[doc(hidden)]
409 #[used(compiler)]
410 static __IS_RUST_MODULE: () = ();
411
412 static mut __MOD: ::core::mem::MaybeUninit<{type_}> =
413 ::core::mem::MaybeUninit::uninit();
414
415 // Loadable modules need to export the `{{init,cleanup}}_module` identifiers.
416 /// # Safety
417 ///
418 /// This function must not be called after module initialization, because it may be
419 /// freed after that completes.
420 #[cfg(MODULE)]
421 #[doc(hidden)]
422 #[no_mangle]
423 #[link_section = \".init.text\"]
424 pub unsafe extern \"C\" fn init_module() -> ::kernel::ffi::c_int {{
425 // SAFETY: This function is inaccessible to the outside due to the double
426 // module wrapping it. It is called exactly once by the C side via its
427 // unique name.
428 unsafe {{ __init() }}
429 }}
430
431 #[cfg(MODULE)]
432 #[doc(hidden)]
433 #[used(compiler)]
434 #[link_section = \".init.data\"]
435 static __UNIQUE_ID___addressable_init_module: unsafe extern \"C\" fn() -> i32 = init_module;
436
437 #[cfg(MODULE)]
438 #[doc(hidden)]
439 #[no_mangle]
440 #[link_section = \".exit.text\"]
441 pub extern \"C\" fn cleanup_module() {{
442 // SAFETY:
443 // - This function is inaccessible to the outside due to the double
444 // module wrapping it. It is called exactly once by the C side via its
445 // unique name,
446 // - furthermore it is only called after `init_module` has returned `0`
447 // (which delegates to `__init`).
448 unsafe {{ __exit() }}
449 }}
450
451 #[cfg(MODULE)]
452 #[doc(hidden)]
453 #[used(compiler)]
454 #[link_section = \".exit.data\"]
455 static __UNIQUE_ID___addressable_cleanup_module: extern \"C\" fn() = cleanup_module;
456
457 // Built-in modules are initialized through an initcall pointer
458 // and the identifiers need to be unique.
459 #[cfg(not(MODULE))]
460 #[cfg(not(CONFIG_HAVE_ARCH_PREL32_RELOCATIONS))]
461 #[doc(hidden)]
462 #[link_section = \"{initcall_section}\"]
463 #[used(compiler)]
464 pub static __{ident}_initcall: extern \"C\" fn() ->
465 ::kernel::ffi::c_int = __{ident}_init;
466
467 #[cfg(not(MODULE))]
468 #[cfg(CONFIG_HAVE_ARCH_PREL32_RELOCATIONS)]
469 ::core::arch::global_asm!(
470 r#\".section \"{initcall_section}\", \"a\"
471 __{ident}_initcall:
472 .long __{ident}_init - .
473 .previous
474 \"#
475 );
476
477 #[cfg(not(MODULE))]
478 #[doc(hidden)]
479 #[no_mangle]
480 pub extern \"C\" fn __{ident}_init() -> ::kernel::ffi::c_int {{
481 // SAFETY: This function is inaccessible to the outside due to the double
482 // module wrapping it. It is called exactly once by the C side via its
483 // placement above in the initcall section.
484 unsafe {{ __init() }}
485 }}
486
487 #[cfg(not(MODULE))]
488 #[doc(hidden)]
489 #[no_mangle]
490 pub extern \"C\" fn __{ident}_exit() {{
491 // SAFETY:
492 // - This function is inaccessible to the outside due to the double
493 // module wrapping it. It is called exactly once by the C side via its
494 // unique name,
495 // - furthermore it is only called after `__{ident}_init` has
496 // returned `0` (which delegates to `__init`).
497 unsafe {{ __exit() }}
498 }}
499
500 /// # Safety
501 ///
502 /// This function must only be called once.
503 unsafe fn __init() -> ::kernel::ffi::c_int {{
504 let initer =
505 <{type_} as ::kernel::InPlaceModule>::init(&super::super::THIS_MODULE);
506 // SAFETY: No data race, since `__MOD` can only be accessed by this module
507 // and there only `__init` and `__exit` access it. These functions are only
508 // called once and `__exit` cannot be called before or during `__init`.
509 match unsafe {{ initer.__pinned_init(__MOD.as_mut_ptr()) }} {{
510 Ok(m) => 0,
511 Err(e) => e.to_errno(),
512 }}
513 }}
514
515 /// # Safety
516 ///
517 /// This function must
518 /// - only be called once,
519 /// - be called after `__init` has been called and returned `0`.
520 unsafe fn __exit() {{
521 // SAFETY: No data race, since `__MOD` can only be accessed by this module
522 // and there only `__init` and `__exit` access it. These functions are only
523 // called once and `__init` was already called.
524 unsafe {{
525 // Invokes `drop()` on `__MOD`, which should be used for cleanup.
526 __MOD.assume_init_drop();
527 }}
528 }}
529 {modinfo}
530 }}
531 }}
532 mod module_parameters {{
533 {params}
534 }}
535 ",
536 type_ = info.type_,
537 name = info.name,
538 ident = ident,
539 modinfo = modinfo.buffer,
540 params = modinfo.param_buffer,
541 initcall_section = ".initcall6.init"
542 )
543 .parse()
544 .expect("Error parsing formatted string into token stream.")
545 }
546