module.h 16 KB

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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 <rth@tamu.edu> Dec 1996
  7. * Rewritten again by Rusty Russell, 2002
  8. */
  9. #include <linux/sched.h>
  10. #include <linux/spinlock.h>
  11. #include <linux/list.h>
  12. #include <linux/stat.h>
  13. #include <linux/compiler.h>
  14. #include <linux/cache.h>
  15. #include <linux/kmod.h>
  16. #include <linux/elf.h>
  17. #include <linux/stringify.h>
  18. #include <linux/kobject.h>
  19. #include <linux/moduleparam.h>
  20. #include <asm/local.h>
  21. #include <asm/module.h>
  22. /* Not Yet Implemented */
  23. #define MODULE_SUPPORTED_DEVICE(name)
  24. /* v850 toolchain uses a `_' prefix for all user symbols */
  25. #ifndef MODULE_SYMBOL_PREFIX
  26. #define MODULE_SYMBOL_PREFIX ""
  27. #endif
  28. #define MODULE_NAME_LEN (64 - sizeof(unsigned long))
  29. struct kernel_symbol
  30. {
  31. unsigned long value;
  32. const char *name;
  33. };
  34. struct modversion_info
  35. {
  36. unsigned long crc;
  37. char name[MODULE_NAME_LEN];
  38. };
  39. struct module;
  40. struct module_attribute {
  41. struct attribute attr;
  42. ssize_t (*show)(struct module_attribute *, struct module *, char *);
  43. ssize_t (*store)(struct module_attribute *, struct module *,
  44. const char *, size_t count);
  45. void (*setup)(struct module *, const char *);
  46. int (*test)(struct module *);
  47. void (*free)(struct module *);
  48. };
  49. struct module_kobject
  50. {
  51. struct kobject kobj;
  52. struct module *mod;
  53. };
  54. /* These are either module local, or the kernel's dummy ones. */
  55. extern int init_module(void);
  56. extern void cleanup_module(void);
  57. /* Archs provide a method of finding the correct exception table. */
  58. struct exception_table_entry;
  59. const struct exception_table_entry *
  60. search_extable(const struct exception_table_entry *first,
  61. const struct exception_table_entry *last,
  62. unsigned long value);
  63. void sort_extable(struct exception_table_entry *start,
  64. struct exception_table_entry *finish);
  65. void sort_main_extable(void);
  66. extern struct subsystem module_subsys;
  67. #ifdef MODULE
  68. #define MODULE_GENERIC_TABLE(gtype,name) \
  69. extern const struct gtype##_id __mod_##gtype##_table \
  70. __attribute__ ((unused, alias(__stringify(name))))
  71. extern struct module __this_module;
  72. #define THIS_MODULE (&__this_module)
  73. #else /* !MODULE */
  74. #define MODULE_GENERIC_TABLE(gtype,name)
  75. #define THIS_MODULE ((struct module *)0)
  76. #endif
  77. /* Generic info of form tag = "info" */
  78. #define MODULE_INFO(tag, info) __MODULE_INFO(tag, tag, info)
  79. /* For userspace: you can also call me... */
  80. #define MODULE_ALIAS(_alias) MODULE_INFO(alias, _alias)
  81. /*
  82. * The following license idents are currently accepted as indicating free
  83. * software modules
  84. *
  85. * "GPL" [GNU Public License v2 or later]
  86. * "GPL v2" [GNU Public License v2]
  87. * "GPL and additional rights" [GNU Public License v2 rights and more]
  88. * "Dual BSD/GPL" [GNU Public License v2
  89. * or BSD license choice]
  90. * "Dual MIT/GPL" [GNU Public License v2
  91. * or MIT license choice]
  92. * "Dual MPL/GPL" [GNU Public License v2
  93. * or Mozilla license choice]
  94. *
  95. * The following other idents are available
  96. *
  97. * "Proprietary" [Non free products]
  98. *
  99. * There are dual licensed components, but when running with Linux it is the
  100. * GPL that is relevant so this is a non issue. Similarly LGPL linked with GPL
  101. * is a GPL combined work.
  102. *
  103. * This exists for several reasons
  104. * 1. So modinfo can show license info for users wanting to vet their setup
  105. * is free
  106. * 2. So the community can ignore bug reports including proprietary modules
  107. * 3. So vendors can do likewise based on their own policies
  108. */
  109. #define MODULE_LICENSE(_license) MODULE_INFO(license, _license)
  110. /* Author, ideally of form NAME <EMAIL>[, NAME <EMAIL>]*[ and NAME <EMAIL>] */
  111. #define MODULE_AUTHOR(_author) MODULE_INFO(author, _author)
  112. /* What your module does. */
  113. #define MODULE_DESCRIPTION(_description) MODULE_INFO(description, _description)
  114. /* One for each parameter, describing how to use it. Some files do
  115. multiple of these per line, so can't just use MODULE_INFO. */
  116. #define MODULE_PARM_DESC(_parm, desc) \
  117. __MODULE_INFO(parm, _parm, #_parm ":" desc)
  118. #define MODULE_DEVICE_TABLE(type,name) \
  119. MODULE_GENERIC_TABLE(type##_device,name)
  120. /* Version of form [<epoch>:]<version>[-<extra-version>].
  121. Or for CVS/RCS ID version, everything but the number is stripped.
  122. <epoch>: A (small) unsigned integer which allows you to start versions
  123. anew. If not mentioned, it's zero. eg. "2:1.0" is after
  124. "1:2.0".
  125. <version>: The <version> may contain only alphanumerics and the
  126. character `.'. Ordered by numeric sort for numeric parts,
  127. ascii sort for ascii parts (as per RPM or DEB algorithm).
  128. <extraversion>: Like <version>, but inserted for local
  129. customizations, eg "rh3" or "rusty1".
  130. Using this automatically adds a checksum of the .c files and the
  131. local headers in "srcversion".
  132. */
  133. #define MODULE_VERSION(_version) MODULE_INFO(version, _version)
  134. /* Optional firmware file (or files) needed by the module
  135. * format is simply firmware file name. Multiple firmware
  136. * files require multiple MODULE_FIRMWARE() specifiers */
  137. #define MODULE_FIRMWARE(_firmware) MODULE_INFO(firmware, _firmware)
  138. /* Given an address, look for it in the exception tables */
  139. const struct exception_table_entry *search_exception_tables(unsigned long add);
  140. struct notifier_block;
  141. #ifdef CONFIG_MODULES
  142. /* Get/put a kernel symbol (calls must be symmetric) */
  143. void *__symbol_get(const char *symbol);
  144. void *__symbol_get_gpl(const char *symbol);
  145. #define symbol_get(x) ((typeof(&x))(__symbol_get(MODULE_SYMBOL_PREFIX #x)))
  146. #ifndef __GENKSYMS__
  147. #ifdef CONFIG_MODVERSIONS
  148. /* Mark the CRC weak since genksyms apparently decides not to
  149. * generate a checksums for some symbols */
  150. #define __CRC_SYMBOL(sym, sec) \
  151. extern void *__crc_##sym __attribute__((weak)); \
  152. static const unsigned long __kcrctab_##sym \
  153. __attribute_used__ \
  154. __attribute__((section("__kcrctab" sec), unused)) \
  155. = (unsigned long) &__crc_##sym;
  156. #else
  157. #define __CRC_SYMBOL(sym, sec)
  158. #endif
  159. /* For every exported symbol, place a struct in the __ksymtab section */
  160. #define __EXPORT_SYMBOL(sym, sec) \
  161. extern typeof(sym) sym; \
  162. __CRC_SYMBOL(sym, sec) \
  163. static const char __kstrtab_##sym[] \
  164. __attribute__((section("__ksymtab_strings"))) \
  165. = MODULE_SYMBOL_PREFIX #sym; \
  166. static const struct kernel_symbol __ksymtab_##sym \
  167. __attribute_used__ \
  168. __attribute__((section("__ksymtab" sec), unused)) \
  169. = { (unsigned long)&sym, __kstrtab_##sym }
  170. #define EXPORT_SYMBOL(sym) \
  171. __EXPORT_SYMBOL(sym, "")
  172. #define EXPORT_SYMBOL_GPL(sym) \
  173. __EXPORT_SYMBOL(sym, "_gpl")
  174. #define EXPORT_SYMBOL_GPL_FUTURE(sym) \
  175. __EXPORT_SYMBOL(sym, "_gpl_future")
  176. #ifdef CONFIG_UNUSED_SYMBOLS
  177. #define EXPORT_UNUSED_SYMBOL(sym) __EXPORT_SYMBOL(sym, "_unused")
  178. #define EXPORT_UNUSED_SYMBOL_GPL(sym) __EXPORT_SYMBOL(sym, "_unused_gpl")
  179. #else
  180. #define EXPORT_UNUSED_SYMBOL(sym)
  181. #define EXPORT_UNUSED_SYMBOL_GPL(sym)
  182. #endif
  183. #endif
  184. struct module_ref
  185. {
  186. local_t count;
  187. } ____cacheline_aligned;
  188. enum module_state
  189. {
  190. MODULE_STATE_LIVE,
  191. MODULE_STATE_COMING,
  192. MODULE_STATE_GOING,
  193. };
  194. /* Similar stuff for section attributes. */
  195. struct module_sect_attr
  196. {
  197. struct module_attribute mattr;
  198. char *name;
  199. unsigned long address;
  200. };
  201. struct module_sect_attrs
  202. {
  203. struct attribute_group grp;
  204. int nsections;
  205. struct module_sect_attr attrs[0];
  206. };
  207. struct module_param_attrs;
  208. struct module
  209. {
  210. enum module_state state;
  211. /* Member of list of modules */
  212. struct list_head list;
  213. /* Unique handle for this module */
  214. char name[MODULE_NAME_LEN];
  215. /* Sysfs stuff. */
  216. struct module_kobject mkobj;
  217. struct module_param_attrs *param_attrs;
  218. struct module_attribute *modinfo_attrs;
  219. const char *version;
  220. const char *srcversion;
  221. /* Exported symbols */
  222. const struct kernel_symbol *syms;
  223. unsigned int num_syms;
  224. const unsigned long *crcs;
  225. /* GPL-only exported symbols. */
  226. const struct kernel_symbol *gpl_syms;
  227. unsigned int num_gpl_syms;
  228. const unsigned long *gpl_crcs;
  229. /* unused exported symbols. */
  230. const struct kernel_symbol *unused_syms;
  231. unsigned int num_unused_syms;
  232. const unsigned long *unused_crcs;
  233. /* GPL-only, unused exported symbols. */
  234. const struct kernel_symbol *unused_gpl_syms;
  235. unsigned int num_unused_gpl_syms;
  236. const unsigned long *unused_gpl_crcs;
  237. /* symbols that will be GPL-only in the near future. */
  238. const struct kernel_symbol *gpl_future_syms;
  239. unsigned int num_gpl_future_syms;
  240. const unsigned long *gpl_future_crcs;
  241. /* Exception table */
  242. unsigned int num_exentries;
  243. const struct exception_table_entry *extable;
  244. /* Startup function. */
  245. int (*init)(void);
  246. /* If this is non-NULL, vfree after init() returns */
  247. void *module_init;
  248. /* Here is the actual code + data, vfree'd on unload. */
  249. void *module_core;
  250. /* Here are the sizes of the init and core sections */
  251. unsigned long init_size, core_size;
  252. /* The size of the executable code in each section. */
  253. unsigned long init_text_size, core_text_size;
  254. /* The handle returned from unwind_add_table. */
  255. void *unwind_info;
  256. /* Arch-specific module values */
  257. struct mod_arch_specific arch;
  258. /* Am I unsafe to unload? */
  259. int unsafe;
  260. /* Am I GPL-compatible */
  261. int license_gplok;
  262. unsigned int taints; /* same bits as kernel:tainted */
  263. #ifdef CONFIG_MODULE_UNLOAD
  264. /* Reference counts */
  265. struct module_ref ref[NR_CPUS];
  266. /* What modules depend on me? */
  267. struct list_head modules_which_use_me;
  268. /* Who is waiting for us to be unloaded */
  269. struct task_struct *waiter;
  270. /* Destruction function. */
  271. void (*exit)(void);
  272. #endif
  273. #ifdef CONFIG_KALLSYMS
  274. /* We keep the symbol and string tables for kallsyms. */
  275. Elf_Sym *symtab;
  276. unsigned long num_symtab;
  277. char *strtab;
  278. /* Section attributes */
  279. struct module_sect_attrs *sect_attrs;
  280. #endif
  281. /* Per-cpu data. */
  282. void *percpu;
  283. /* The command line arguments (may be mangled). People like
  284. keeping pointers to this stuff */
  285. char *args;
  286. };
  287. /* FIXME: It'd be nice to isolate modules during init, too, so they
  288. aren't used before they (may) fail. But presently too much code
  289. (IDE & SCSI) require entry into the module during init.*/
  290. static inline int module_is_live(struct module *mod)
  291. {
  292. return mod->state != MODULE_STATE_GOING;
  293. }
  294. /* Is this address in a module? (second is with no locks, for oops) */
  295. struct module *module_text_address(unsigned long addr);
  296. struct module *__module_text_address(unsigned long addr);
  297. int is_module_address(unsigned long addr);
  298. /* Returns module and fills in value, defined and namebuf, or NULL if
  299. symnum out of range. */
  300. struct module *module_get_kallsym(unsigned int symnum, unsigned long *value,
  301. char *type, char *name, size_t namelen);
  302. /* Look for this name: can be of form module:name. */
  303. unsigned long module_kallsyms_lookup_name(const char *name);
  304. int is_exported(const char *name, const struct module *mod);
  305. extern void __module_put_and_exit(struct module *mod, long code)
  306. __attribute__((noreturn));
  307. #define module_put_and_exit(code) __module_put_and_exit(THIS_MODULE, code);
  308. #ifdef CONFIG_MODULE_UNLOAD
  309. unsigned int module_refcount(struct module *mod);
  310. void __symbol_put(const char *symbol);
  311. #define symbol_put(x) __symbol_put(MODULE_SYMBOL_PREFIX #x)
  312. void symbol_put_addr(void *addr);
  313. /* Sometimes we know we already have a refcount, and it's easier not
  314. to handle the error case (which only happens with rmmod --wait). */
  315. static inline void __module_get(struct module *module)
  316. {
  317. if (module) {
  318. BUG_ON(module_refcount(module) == 0);
  319. local_inc(&module->ref[get_cpu()].count);
  320. put_cpu();
  321. }
  322. }
  323. static inline int try_module_get(struct module *module)
  324. {
  325. int ret = 1;
  326. if (module) {
  327. unsigned int cpu = get_cpu();
  328. if (likely(module_is_live(module)))
  329. local_inc(&module->ref[cpu].count);
  330. else
  331. ret = 0;
  332. put_cpu();
  333. }
  334. return ret;
  335. }
  336. static inline void module_put(struct module *module)
  337. {
  338. if (module) {
  339. unsigned int cpu = get_cpu();
  340. local_dec(&module->ref[cpu].count);
  341. /* Maybe they're waiting for us to drop reference? */
  342. if (unlikely(!module_is_live(module)))
  343. wake_up_process(module->waiter);
  344. put_cpu();
  345. }
  346. }
  347. #else /*!CONFIG_MODULE_UNLOAD*/
  348. static inline int try_module_get(struct module *module)
  349. {
  350. return !module || module_is_live(module);
  351. }
  352. static inline void module_put(struct module *module)
  353. {
  354. }
  355. static inline void __module_get(struct module *module)
  356. {
  357. }
  358. #define symbol_put(x) do { } while(0)
  359. #define symbol_put_addr(p) do { } while(0)
  360. #endif /* CONFIG_MODULE_UNLOAD */
  361. /* This is a #define so the string doesn't get put in every .o file */
  362. #define module_name(mod) \
  363. ({ \
  364. struct module *__mod = (mod); \
  365. __mod ? __mod->name : "kernel"; \
  366. })
  367. #define __unsafe(mod) \
  368. do { \
  369. if (mod && !(mod)->unsafe) { \
  370. printk(KERN_WARNING \
  371. "Module %s cannot be unloaded due to unsafe usage in" \
  372. " %s:%u\n", (mod)->name, __FILE__, __LINE__); \
  373. (mod)->unsafe = 1; \
  374. } \
  375. } while(0)
  376. /* For kallsyms to ask for address resolution. NULL means not found. */
  377. const char *module_address_lookup(unsigned long addr,
  378. unsigned long *symbolsize,
  379. unsigned long *offset,
  380. char **modname);
  381. /* For extable.c to search modules' exception tables. */
  382. const struct exception_table_entry *search_module_extables(unsigned long addr);
  383. int register_module_notifier(struct notifier_block * nb);
  384. int unregister_module_notifier(struct notifier_block * nb);
  385. extern void print_modules(void);
  386. struct device_driver;
  387. void module_add_driver(struct module *, struct device_driver *);
  388. void module_remove_driver(struct device_driver *);
  389. #else /* !CONFIG_MODULES... */
  390. #define EXPORT_SYMBOL(sym)
  391. #define EXPORT_SYMBOL_GPL(sym)
  392. #define EXPORT_SYMBOL_GPL_FUTURE(sym)
  393. #define EXPORT_UNUSED_SYMBOL(sym)
  394. #define EXPORT_UNUSED_SYMBOL_GPL(sym)
  395. /* Given an address, look for it in the exception tables. */
  396. static inline const struct exception_table_entry *
  397. search_module_extables(unsigned long addr)
  398. {
  399. return NULL;
  400. }
  401. /* Is this address in a module? */
  402. static inline struct module *module_text_address(unsigned long addr)
  403. {
  404. return NULL;
  405. }
  406. /* Is this address in a module? (don't take a lock, we're oopsing) */
  407. static inline struct module *__module_text_address(unsigned long addr)
  408. {
  409. return NULL;
  410. }
  411. static inline int is_module_address(unsigned long addr)
  412. {
  413. return 0;
  414. }
  415. /* Get/put a kernel symbol (calls should be symmetric) */
  416. #define symbol_get(x) ({ extern typeof(x) x __attribute__((weak)); &(x); })
  417. #define symbol_put(x) do { } while(0)
  418. #define symbol_put_addr(x) do { } while(0)
  419. static inline void __module_get(struct module *module)
  420. {
  421. }
  422. static inline int try_module_get(struct module *module)
  423. {
  424. return 1;
  425. }
  426. static inline void module_put(struct module *module)
  427. {
  428. }
  429. #define module_name(mod) "kernel"
  430. #define __unsafe(mod)
  431. /* For kallsyms to ask for address resolution. NULL means not found. */
  432. static inline const char *module_address_lookup(unsigned long addr,
  433. unsigned long *symbolsize,
  434. unsigned long *offset,
  435. char **modname)
  436. {
  437. return NULL;
  438. }
  439. static inline struct module *module_get_kallsym(unsigned int symnum,
  440. unsigned long *value,
  441. char *type, char *name,
  442. size_t namelen)
  443. {
  444. return NULL;
  445. }
  446. static inline unsigned long module_kallsyms_lookup_name(const char *name)
  447. {
  448. return 0;
  449. }
  450. static inline int is_exported(const char *name, const struct module *mod)
  451. {
  452. return 0;
  453. }
  454. static inline int register_module_notifier(struct notifier_block * nb)
  455. {
  456. /* no events will happen anyway, so this can always succeed */
  457. return 0;
  458. }
  459. static inline int unregister_module_notifier(struct notifier_block * nb)
  460. {
  461. return 0;
  462. }
  463. #define module_put_and_exit(code) do_exit(code)
  464. static inline void print_modules(void)
  465. {
  466. }
  467. struct device_driver;
  468. struct module;
  469. static inline void module_add_driver(struct module *module, struct device_driver *driver)
  470. {
  471. }
  472. static inline void module_remove_driver(struct device_driver *driver)
  473. {
  474. }
  475. #endif /* CONFIG_MODULES */
  476. #define symbol_request(x) try_then_request_module(symbol_get(x), "symbol:" #x)
  477. /* BELOW HERE ALL THESE ARE OBSOLETE AND WILL VANISH */
  478. #define __MODULE_STRING(x) __stringify(x)
  479. #endif /* _LINUX_MODULE_H */