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