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