xref: /linux-6.15/include/linux/module.h (revision 9d54c8a3)
1 #ifndef _LINUX_MODULE_H
2 #define _LINUX_MODULE_H
3 /*
4  * Dynamic loading of modules into the kernel.
5  *
6  * Rewritten by Richard Henderson <[email protected]> Dec 1996
7  * Rewritten again by Rusty Russell, 2002
8  */
9 #include <linux/list.h>
10 #include <linux/stat.h>
11 #include <linux/compiler.h>
12 #include <linux/cache.h>
13 #include <linux/kmod.h>
14 #include <linux/elf.h>
15 #include <linux/stringify.h>
16 #include <linux/kobject.h>
17 #include <linux/moduleparam.h>
18 #include <linux/tracepoint.h>
19 #include <linux/export.h>
20 
21 #include <linux/percpu.h>
22 #include <asm/module.h>
23 
24 /* In stripped ARM and x86-64 modules, ~ is surprisingly rare. */
25 #define MODULE_SIG_STRING "~Module signature appended~\n"
26 
27 /* Not Yet Implemented */
28 #define MODULE_SUPPORTED_DEVICE(name)
29 
30 #define MODULE_NAME_LEN MAX_PARAM_PREFIX_LEN
31 
32 struct modversion_info {
33 	unsigned long crc;
34 	char name[MODULE_NAME_LEN];
35 };
36 
37 struct module;
38 
39 struct module_kobject {
40 	struct kobject kobj;
41 	struct module *mod;
42 	struct kobject *drivers_dir;
43 	struct module_param_attrs *mp;
44 	struct completion *kobj_completion;
45 };
46 
47 struct module_attribute {
48 	struct attribute attr;
49 	ssize_t (*show)(struct module_attribute *, struct module_kobject *,
50 			char *);
51 	ssize_t (*store)(struct module_attribute *, struct module_kobject *,
52 			 const char *, size_t count);
53 	void (*setup)(struct module *, const char *);
54 	int (*test)(struct module *);
55 	void (*free)(struct module *);
56 };
57 
58 struct module_version_attribute {
59 	struct module_attribute mattr;
60 	const char *module_name;
61 	const char *version;
62 } __attribute__ ((__aligned__(sizeof(void *))));
63 
64 extern ssize_t __modver_version_show(struct module_attribute *,
65 				     struct module_kobject *, char *);
66 
67 extern struct module_attribute module_uevent;
68 
69 /* These are either module local, or the kernel's dummy ones. */
70 extern int init_module(void);
71 extern void cleanup_module(void);
72 
73 /* Archs provide a method of finding the correct exception table. */
74 struct exception_table_entry;
75 
76 const struct exception_table_entry *
77 search_extable(const struct exception_table_entry *first,
78 	       const struct exception_table_entry *last,
79 	       unsigned long value);
80 void sort_extable(struct exception_table_entry *start,
81 		  struct exception_table_entry *finish);
82 void sort_main_extable(void);
83 void trim_init_extable(struct module *m);
84 
85 #ifdef MODULE
86 #define MODULE_GENERIC_TABLE(gtype, name)			\
87 extern const struct gtype##_id __mod_##gtype##_table		\
88   __attribute__ ((unused, alias(__stringify(name))))
89 
90 #else  /* !MODULE */
91 #define MODULE_GENERIC_TABLE(gtype, name)
92 #endif
93 
94 /* Generic info of form tag = "info" */
95 #define MODULE_INFO(tag, info) __MODULE_INFO(tag, tag, info)
96 
97 /* For userspace: you can also call me... */
98 #define MODULE_ALIAS(_alias) MODULE_INFO(alias, _alias)
99 
100 /* Soft module dependencies. See man modprobe.d for details.
101  * Example: MODULE_SOFTDEP("pre: module-foo module-bar post: module-baz")
102  */
103 #define MODULE_SOFTDEP(_softdep) MODULE_INFO(softdep, _softdep)
104 
105 /*
106  * The following license idents are currently accepted as indicating free
107  * software modules
108  *
109  *	"GPL"				[GNU Public License v2 or later]
110  *	"GPL v2"			[GNU Public License v2]
111  *	"GPL and additional rights"	[GNU Public License v2 rights and more]
112  *	"Dual BSD/GPL"			[GNU Public License v2
113  *					 or BSD license choice]
114  *	"Dual MIT/GPL"			[GNU Public License v2
115  *					 or MIT license choice]
116  *	"Dual MPL/GPL"			[GNU Public License v2
117  *					 or Mozilla license choice]
118  *
119  * The following other idents are available
120  *
121  *	"Proprietary"			[Non free products]
122  *
123  * There are dual licensed components, but when running with Linux it is the
124  * GPL that is relevant so this is a non issue. Similarly LGPL linked with GPL
125  * is a GPL combined work.
126  *
127  * This exists for several reasons
128  * 1.	So modinfo can show license info for users wanting to vet their setup
129  *	is free
130  * 2.	So the community can ignore bug reports including proprietary modules
131  * 3.	So vendors can do likewise based on their own policies
132  */
133 #define MODULE_LICENSE(_license) MODULE_INFO(license, _license)
134 
135 /*
136  * Author(s), use "Name <email>" or just "Name", for multiple
137  * authors use multiple MODULE_AUTHOR() statements/lines.
138  */
139 #define MODULE_AUTHOR(_author) MODULE_INFO(author, _author)
140 
141 /* What your module does. */
142 #define MODULE_DESCRIPTION(_description) MODULE_INFO(description, _description)
143 
144 #define MODULE_DEVICE_TABLE(type, name)		\
145   MODULE_GENERIC_TABLE(type##_device, name)
146 
147 /* Version of form [<epoch>:]<version>[-<extra-version>].
148  * Or for CVS/RCS ID version, everything but the number is stripped.
149  * <epoch>: A (small) unsigned integer which allows you to start versions
150  * anew. If not mentioned, it's zero.  eg. "2:1.0" is after
151  * "1:2.0".
152 
153  * <version>: The <version> may contain only alphanumerics and the
154  * character `.'.  Ordered by numeric sort for numeric parts,
155  * ascii sort for ascii parts (as per RPM or DEB algorithm).
156 
157  * <extraversion>: Like <version>, but inserted for local
158  * customizations, eg "rh3" or "rusty1".
159 
160  * Using this automatically adds a checksum of the .c files and the
161  * local headers in "srcversion".
162  */
163 
164 #if defined(MODULE) || !defined(CONFIG_SYSFS)
165 #define MODULE_VERSION(_version) MODULE_INFO(version, _version)
166 #else
167 #define MODULE_VERSION(_version)					\
168 	static struct module_version_attribute ___modver_attr = {	\
169 		.mattr	= {						\
170 			.attr	= {					\
171 				.name	= "version",			\
172 				.mode	= S_IRUGO,			\
173 			},						\
174 			.show	= __modver_version_show,		\
175 		},							\
176 		.module_name	= KBUILD_MODNAME,			\
177 		.version	= _version,				\
178 	};								\
179 	static const struct module_version_attribute			\
180 	__used __attribute__ ((__section__ ("__modver")))		\
181 	* __moduleparam_const __modver_attr = &___modver_attr
182 #endif
183 
184 /* Optional firmware file (or files) needed by the module
185  * format is simply firmware file name.  Multiple firmware
186  * files require multiple MODULE_FIRMWARE() specifiers */
187 #define MODULE_FIRMWARE(_firmware) MODULE_INFO(firmware, _firmware)
188 
189 /* Given an address, look for it in the exception tables */
190 const struct exception_table_entry *search_exception_tables(unsigned long add);
191 
192 struct notifier_block;
193 
194 #ifdef CONFIG_MODULES
195 
196 extern int modules_disabled; /* for sysctl */
197 /* Get/put a kernel symbol (calls must be symmetric) */
198 void *__symbol_get(const char *symbol);
199 void *__symbol_get_gpl(const char *symbol);
200 #define symbol_get(x) ((typeof(&x))(__symbol_get(VMLINUX_SYMBOL_STR(x))))
201 
202 /* modules using other modules: kdb wants to see this. */
203 struct module_use {
204 	struct list_head source_list;
205 	struct list_head target_list;
206 	struct module *source, *target;
207 };
208 
209 enum module_state {
210 	MODULE_STATE_LIVE,	/* Normal state. */
211 	MODULE_STATE_COMING,	/* Full formed, running module_init. */
212 	MODULE_STATE_GOING,	/* Going away. */
213 	MODULE_STATE_UNFORMED,	/* Still setting it up. */
214 };
215 
216 /**
217  * struct module_ref - per cpu module reference counts
218  * @incs: number of module get on this cpu
219  * @decs: number of module put on this cpu
220  *
221  * We force an alignment on 8 or 16 bytes, so that alloc_percpu()
222  * put @incs/@decs in same cache line, with no extra memory cost,
223  * since alloc_percpu() is fine grained.
224  */
225 struct module_ref {
226 	unsigned long incs;
227 	unsigned long decs;
228 } __attribute((aligned(2 * sizeof(unsigned long))));
229 
230 struct module {
231 	enum module_state state;
232 
233 	/* Member of list of modules */
234 	struct list_head list;
235 
236 	/* Unique handle for this module */
237 	char name[MODULE_NAME_LEN];
238 
239 	/* Sysfs stuff. */
240 	struct module_kobject mkobj;
241 	struct module_attribute *modinfo_attrs;
242 	const char *version;
243 	const char *srcversion;
244 	struct kobject *holders_dir;
245 
246 	/* Exported symbols */
247 	const struct kernel_symbol *syms;
248 	const unsigned long *crcs;
249 	unsigned int num_syms;
250 
251 	/* Kernel parameters. */
252 	struct kernel_param *kp;
253 	unsigned int num_kp;
254 
255 	/* GPL-only exported symbols. */
256 	unsigned int num_gpl_syms;
257 	const struct kernel_symbol *gpl_syms;
258 	const unsigned long *gpl_crcs;
259 
260 #ifdef CONFIG_UNUSED_SYMBOLS
261 	/* unused exported symbols. */
262 	const struct kernel_symbol *unused_syms;
263 	const unsigned long *unused_crcs;
264 	unsigned int num_unused_syms;
265 
266 	/* GPL-only, unused exported symbols. */
267 	unsigned int num_unused_gpl_syms;
268 	const struct kernel_symbol *unused_gpl_syms;
269 	const unsigned long *unused_gpl_crcs;
270 #endif
271 
272 #ifdef CONFIG_MODULE_SIG
273 	/* Signature was verified. */
274 	bool sig_ok;
275 #endif
276 
277 	/* symbols that will be GPL-only in the near future. */
278 	const struct kernel_symbol *gpl_future_syms;
279 	const unsigned long *gpl_future_crcs;
280 	unsigned int num_gpl_future_syms;
281 
282 	/* Exception table */
283 	unsigned int num_exentries;
284 	struct exception_table_entry *extable;
285 
286 	/* Startup function. */
287 	int (*init)(void);
288 
289 	/* If this is non-NULL, vfree after init() returns */
290 	void *module_init;
291 
292 	/* Here is the actual code + data, vfree'd on unload. */
293 	void *module_core;
294 
295 	/* Here are the sizes of the init and core sections */
296 	unsigned int init_size, core_size;
297 
298 	/* The size of the executable code in each section.  */
299 	unsigned int init_text_size, core_text_size;
300 
301 	/* Size of RO sections of the module (text+rodata) */
302 	unsigned int init_ro_size, core_ro_size;
303 
304 	/* Arch-specific module values */
305 	struct mod_arch_specific arch;
306 
307 	unsigned int taints;	/* same bits as kernel:tainted */
308 
309 #ifdef CONFIG_GENERIC_BUG
310 	/* Support for BUG */
311 	unsigned num_bugs;
312 	struct list_head bug_list;
313 	struct bug_entry *bug_table;
314 #endif
315 
316 #ifdef CONFIG_KALLSYMS
317 	/*
318 	 * We keep the symbol and string tables for kallsyms.
319 	 * The core_* fields below are temporary, loader-only (they
320 	 * could really be discarded after module init).
321 	 */
322 	Elf_Sym *symtab, *core_symtab;
323 	unsigned int num_symtab, core_num_syms;
324 	char *strtab, *core_strtab;
325 
326 	/* Section attributes */
327 	struct module_sect_attrs *sect_attrs;
328 
329 	/* Notes attributes */
330 	struct module_notes_attrs *notes_attrs;
331 #endif
332 
333 	/* The command line arguments (may be mangled).  People like
334 	   keeping pointers to this stuff */
335 	char *args;
336 
337 #ifdef CONFIG_SMP
338 	/* Per-cpu data. */
339 	void __percpu *percpu;
340 	unsigned int percpu_size;
341 #endif
342 
343 #ifdef CONFIG_TRACEPOINTS
344 	unsigned int num_tracepoints;
345 	struct tracepoint * const *tracepoints_ptrs;
346 #endif
347 #ifdef HAVE_JUMP_LABEL
348 	struct jump_entry *jump_entries;
349 	unsigned int num_jump_entries;
350 #endif
351 #ifdef CONFIG_TRACING
352 	unsigned int num_trace_bprintk_fmt;
353 	const char **trace_bprintk_fmt_start;
354 #endif
355 #ifdef CONFIG_EVENT_TRACING
356 	struct ftrace_event_call **trace_events;
357 	unsigned int num_trace_events;
358 #endif
359 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
360 	unsigned int num_ftrace_callsites;
361 	unsigned long *ftrace_callsites;
362 #endif
363 
364 #ifdef CONFIG_MODULE_UNLOAD
365 	/* What modules depend on me? */
366 	struct list_head source_list;
367 	/* What modules do I depend on? */
368 	struct list_head target_list;
369 
370 	/* Destruction function. */
371 	void (*exit)(void);
372 
373 	struct module_ref __percpu *refptr;
374 #endif
375 
376 #ifdef CONFIG_CONSTRUCTORS
377 	/* Constructor functions. */
378 	ctor_fn_t *ctors;
379 	unsigned int num_ctors;
380 #endif
381 };
382 #ifndef MODULE_ARCH_INIT
383 #define MODULE_ARCH_INIT {}
384 #endif
385 
386 extern struct mutex module_mutex;
387 
388 /* FIXME: It'd be nice to isolate modules during init, too, so they
389    aren't used before they (may) fail.  But presently too much code
390    (IDE & SCSI) require entry into the module during init.*/
391 static inline int module_is_live(struct module *mod)
392 {
393 	return mod->state != MODULE_STATE_GOING;
394 }
395 
396 struct module *__module_text_address(unsigned long addr);
397 struct module *__module_address(unsigned long addr);
398 bool is_module_address(unsigned long addr);
399 bool is_module_percpu_address(unsigned long addr);
400 bool is_module_text_address(unsigned long addr);
401 
402 static inline int within_module_core(unsigned long addr, const struct module *mod)
403 {
404 	return (unsigned long)mod->module_core <= addr &&
405 	       addr < (unsigned long)mod->module_core + mod->core_size;
406 }
407 
408 static inline int within_module_init(unsigned long addr, const struct module *mod)
409 {
410 	return (unsigned long)mod->module_init <= addr &&
411 	       addr < (unsigned long)mod->module_init + mod->init_size;
412 }
413 
414 /* Search for module by name: must hold module_mutex. */
415 struct module *find_module(const char *name);
416 
417 struct symsearch {
418 	const struct kernel_symbol *start, *stop;
419 	const unsigned long *crcs;
420 	enum {
421 		NOT_GPL_ONLY,
422 		GPL_ONLY,
423 		WILL_BE_GPL_ONLY,
424 	} licence;
425 	bool unused;
426 };
427 
428 /* Search for an exported symbol by name. */
429 const struct kernel_symbol *find_symbol(const char *name,
430 					struct module **owner,
431 					const unsigned long **crc,
432 					bool gplok,
433 					bool warn);
434 
435 /* Walk the exported symbol table */
436 bool each_symbol_section(bool (*fn)(const struct symsearch *arr,
437 				    struct module *owner,
438 				    void *data), void *data);
439 
440 /* Returns 0 and fills in value, defined and namebuf, or -ERANGE if
441    symnum out of range. */
442 int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
443 			char *name, char *module_name, int *exported);
444 
445 /* Look for this name: can be of form module:name. */
446 unsigned long module_kallsyms_lookup_name(const char *name);
447 
448 int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
449 					     struct module *, unsigned long),
450 				   void *data);
451 
452 extern void __module_put_and_exit(struct module *mod, long code)
453 	__attribute__((noreturn));
454 #define module_put_and_exit(code) __module_put_and_exit(THIS_MODULE, code)
455 
456 #ifdef CONFIG_MODULE_UNLOAD
457 unsigned long module_refcount(struct module *mod);
458 void __symbol_put(const char *symbol);
459 #define symbol_put(x) __symbol_put(VMLINUX_SYMBOL_STR(x))
460 void symbol_put_addr(void *addr);
461 
462 /* Sometimes we know we already have a refcount, and it's easier not
463    to handle the error case (which only happens with rmmod --wait). */
464 extern void __module_get(struct module *module);
465 
466 /* This is the Right Way to get a module: if it fails, it's being removed,
467  * so pretend it's not there. */
468 extern bool try_module_get(struct module *module);
469 
470 extern void module_put(struct module *module);
471 
472 #else /*!CONFIG_MODULE_UNLOAD*/
473 static inline int try_module_get(struct module *module)
474 {
475 	return !module || module_is_live(module);
476 }
477 static inline void module_put(struct module *module)
478 {
479 }
480 static inline void __module_get(struct module *module)
481 {
482 }
483 #define symbol_put(x) do { } while (0)
484 #define symbol_put_addr(p) do { } while (0)
485 
486 #endif /* CONFIG_MODULE_UNLOAD */
487 int ref_module(struct module *a, struct module *b);
488 
489 /* This is a #define so the string doesn't get put in every .o file */
490 #define module_name(mod)			\
491 ({						\
492 	struct module *__mod = (mod);		\
493 	__mod ? __mod->name : "kernel";		\
494 })
495 
496 /* For kallsyms to ask for address resolution.  namebuf should be at
497  * least KSYM_NAME_LEN long: a pointer to namebuf is returned if
498  * found, otherwise NULL. */
499 const char *module_address_lookup(unsigned long addr,
500 			    unsigned long *symbolsize,
501 			    unsigned long *offset,
502 			    char **modname,
503 			    char *namebuf);
504 int lookup_module_symbol_name(unsigned long addr, char *symname);
505 int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name);
506 
507 /* For extable.c to search modules' exception tables. */
508 const struct exception_table_entry *search_module_extables(unsigned long addr);
509 
510 int register_module_notifier(struct notifier_block *nb);
511 int unregister_module_notifier(struct notifier_block *nb);
512 
513 extern void print_modules(void);
514 
515 #else /* !CONFIG_MODULES... */
516 
517 /* Given an address, look for it in the exception tables. */
518 static inline const struct exception_table_entry *
519 search_module_extables(unsigned long addr)
520 {
521 	return NULL;
522 }
523 
524 static inline struct module *__module_address(unsigned long addr)
525 {
526 	return NULL;
527 }
528 
529 static inline struct module *__module_text_address(unsigned long addr)
530 {
531 	return NULL;
532 }
533 
534 static inline bool is_module_address(unsigned long addr)
535 {
536 	return false;
537 }
538 
539 static inline bool is_module_percpu_address(unsigned long addr)
540 {
541 	return false;
542 }
543 
544 static inline bool is_module_text_address(unsigned long addr)
545 {
546 	return false;
547 }
548 
549 /* Get/put a kernel symbol (calls should be symmetric) */
550 #define symbol_get(x) ({ extern typeof(x) x __attribute__((weak)); &(x); })
551 #define symbol_put(x) do { } while (0)
552 #define symbol_put_addr(x) do { } while (0)
553 
554 static inline void __module_get(struct module *module)
555 {
556 }
557 
558 static inline int try_module_get(struct module *module)
559 {
560 	return 1;
561 }
562 
563 static inline void module_put(struct module *module)
564 {
565 }
566 
567 #define module_name(mod) "kernel"
568 
569 /* For kallsyms to ask for address resolution.  NULL means not found. */
570 static inline const char *module_address_lookup(unsigned long addr,
571 					  unsigned long *symbolsize,
572 					  unsigned long *offset,
573 					  char **modname,
574 					  char *namebuf)
575 {
576 	return NULL;
577 }
578 
579 static inline int lookup_module_symbol_name(unsigned long addr, char *symname)
580 {
581 	return -ERANGE;
582 }
583 
584 static inline int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name)
585 {
586 	return -ERANGE;
587 }
588 
589 static inline int module_get_kallsym(unsigned int symnum, unsigned long *value,
590 					char *type, char *name,
591 					char *module_name, int *exported)
592 {
593 	return -ERANGE;
594 }
595 
596 static inline unsigned long module_kallsyms_lookup_name(const char *name)
597 {
598 	return 0;
599 }
600 
601 static inline int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
602 							   struct module *,
603 							   unsigned long),
604 						 void *data)
605 {
606 	return 0;
607 }
608 
609 static inline int register_module_notifier(struct notifier_block *nb)
610 {
611 	/* no events will happen anyway, so this can always succeed */
612 	return 0;
613 }
614 
615 static inline int unregister_module_notifier(struct notifier_block *nb)
616 {
617 	return 0;
618 }
619 
620 #define module_put_and_exit(code) do_exit(code)
621 
622 static inline void print_modules(void)
623 {
624 }
625 #endif /* CONFIG_MODULES */
626 
627 #ifdef CONFIG_SYSFS
628 extern struct kset *module_kset;
629 extern struct kobj_type module_ktype;
630 extern int module_sysfs_initialized;
631 #endif /* CONFIG_SYSFS */
632 
633 #define symbol_request(x) try_then_request_module(symbol_get(x), "symbol:" #x)
634 
635 /* BELOW HERE ALL THESE ARE OBSOLETE AND WILL VANISH */
636 
637 #define __MODULE_STRING(x) __stringify(x)
638 
639 #ifdef CONFIG_DEBUG_SET_MODULE_RONX
640 extern void set_all_modules_text_rw(void);
641 extern void set_all_modules_text_ro(void);
642 #else
643 static inline void set_all_modules_text_rw(void) { }
644 static inline void set_all_modules_text_ro(void) { }
645 #endif
646 
647 #ifdef CONFIG_GENERIC_BUG
648 void module_bug_finalize(const Elf_Ehdr *, const Elf_Shdr *,
649 			 struct module *);
650 void module_bug_cleanup(struct module *);
651 
652 #else	/* !CONFIG_GENERIC_BUG */
653 
654 static inline void module_bug_finalize(const Elf_Ehdr *hdr,
655 					const Elf_Shdr *sechdrs,
656 					struct module *mod)
657 {
658 }
659 static inline void module_bug_cleanup(struct module *mod) {}
660 #endif	/* CONFIG_GENERIC_BUG */
661 
662 #endif /* _LINUX_MODULE_H */
663