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. /* Given an address, look for it in the exception tables */
  135. const struct exception_table_entry *search_exception_tables(unsigned long add);
  136. struct notifier_block;
  137. #ifdef CONFIG_MODULES
  138. /* Get/put a kernel symbol (calls must be symmetric) */
  139. void *__symbol_get(const char *symbol);
  140. void *__symbol_get_gpl(const char *symbol);
  141. #define symbol_get(x) ((typeof(&x))(__symbol_get(MODULE_SYMBOL_PREFIX #x)))
  142. #ifndef __GENKSYMS__
  143. #ifdef CONFIG_MODVERSIONS
  144. /* Mark the CRC weak since genksyms apparently decides not to
  145. * generate a checksums for some symbols */
  146. #define __CRC_SYMBOL(sym, sec) \
  147. extern void *__crc_##sym __attribute__((weak)); \
  148. static const unsigned long __kcrctab_##sym \
  149. __attribute_used__ \
  150. __attribute__((section("__kcrctab" sec), unused)) \
  151. = (unsigned long) &__crc_##sym;
  152. #else
  153. #define __CRC_SYMBOL(sym, sec)
  154. #endif
  155. /* For every exported symbol, place a struct in the __ksymtab section */
  156. #define __EXPORT_SYMBOL(sym, sec) \
  157. extern typeof(sym) sym; \
  158. __CRC_SYMBOL(sym, sec) \
  159. static const char __kstrtab_##sym[] \
  160. __attribute__((section("__ksymtab_strings"))) \
  161. = MODULE_SYMBOL_PREFIX #sym; \
  162. static const struct kernel_symbol __ksymtab_##sym \
  163. __attribute_used__ \
  164. __attribute__((section("__ksymtab" sec), unused)) \
  165. = { (unsigned long)&sym, __kstrtab_##sym }
  166. #define EXPORT_SYMBOL(sym) \
  167. __EXPORT_SYMBOL(sym, "")
  168. #define EXPORT_SYMBOL_GPL(sym) \
  169. __EXPORT_SYMBOL(sym, "_gpl")
  170. #define EXPORT_SYMBOL_GPL_FUTURE(sym) \
  171. __EXPORT_SYMBOL(sym, "_gpl_future")
  172. #ifdef CONFIG_UNUSED_SYMBOLS
  173. #define EXPORT_UNUSED_SYMBOL(sym) __EXPORT_SYMBOL(sym, "_unused")
  174. #define EXPORT_UNUSED_SYMBOL_GPL(sym) __EXPORT_SYMBOL(sym, "_unused_gpl")
  175. #else
  176. #define EXPORT_UNUSED_SYMBOL(sym)
  177. #define EXPORT_UNUSED_SYMBOL_GPL(sym)
  178. #endif
  179. #endif
  180. struct module_ref
  181. {
  182. local_t count;
  183. } ____cacheline_aligned;
  184. enum module_state
  185. {
  186. MODULE_STATE_LIVE,
  187. MODULE_STATE_COMING,
  188. MODULE_STATE_GOING,
  189. };
  190. /* Similar stuff for section attributes. */
  191. #define MODULE_SECT_NAME_LEN 32
  192. struct module_sect_attr
  193. {
  194. struct module_attribute mattr;
  195. char name[MODULE_SECT_NAME_LEN];
  196. unsigned long address;
  197. };
  198. struct module_sect_attrs
  199. {
  200. struct attribute_group grp;
  201. struct module_sect_attr attrs[0];
  202. };
  203. struct module_param_attrs;
  204. struct module
  205. {
  206. enum module_state state;
  207. /* Member of list of modules */
  208. struct list_head list;
  209. /* Unique handle for this module */
  210. char name[MODULE_NAME_LEN];
  211. /* Sysfs stuff. */
  212. struct module_kobject mkobj;
  213. struct module_param_attrs *param_attrs;
  214. struct module_attribute *modinfo_attrs;
  215. const char *version;
  216. const char *srcversion;
  217. /* Exported symbols */
  218. const struct kernel_symbol *syms;
  219. unsigned int num_syms;
  220. const unsigned long *crcs;
  221. /* GPL-only exported symbols. */
  222. const struct kernel_symbol *gpl_syms;
  223. unsigned int num_gpl_syms;
  224. const unsigned long *gpl_crcs;
  225. /* unused exported symbols. */
  226. const struct kernel_symbol *unused_syms;
  227. unsigned int num_unused_syms;
  228. const unsigned long *unused_crcs;
  229. /* GPL-only, unused exported symbols. */
  230. const struct kernel_symbol *unused_gpl_syms;
  231. unsigned int num_unused_gpl_syms;
  232. const unsigned long *unused_gpl_crcs;
  233. /* symbols that will be GPL-only in the near future. */
  234. const struct kernel_symbol *gpl_future_syms;
  235. unsigned int num_gpl_future_syms;
  236. const unsigned long *gpl_future_crcs;
  237. /* Exception table */
  238. unsigned int num_exentries;
  239. const struct exception_table_entry *extable;
  240. /* Startup function. */
  241. int (*init)(void);
  242. /* If this is non-NULL, vfree after init() returns */
  243. void *module_init;
  244. /* Here is the actual code + data, vfree'd on unload. */
  245. void *module_core;
  246. /* Here are the sizes of the init and core sections */
  247. unsigned long init_size, core_size;
  248. /* The size of the executable code in each section. */
  249. unsigned long init_text_size, core_text_size;
  250. /* The handle returned from unwind_add_table. */
  251. void *unwind_info;
  252. /* Arch-specific module values */
  253. struct mod_arch_specific arch;
  254. /* Am I unsafe to unload? */
  255. int unsafe;
  256. /* Am I GPL-compatible */
  257. int license_gplok;
  258. #ifdef CONFIG_MODULE_UNLOAD
  259. /* Reference counts */
  260. struct module_ref ref[NR_CPUS];
  261. /* What modules depend on me? */
  262. struct list_head modules_which_use_me;
  263. /* Who is waiting for us to be unloaded */
  264. struct task_struct *waiter;
  265. /* Destruction function. */
  266. void (*exit)(void);
  267. #endif
  268. #ifdef CONFIG_KALLSYMS
  269. /* We keep the symbol and string tables for kallsyms. */
  270. Elf_Sym *symtab;
  271. unsigned long num_symtab;
  272. char *strtab;
  273. /* Section attributes */
  274. struct module_sect_attrs *sect_attrs;
  275. #endif
  276. /* Per-cpu data. */
  277. void *percpu;
  278. /* The command line arguments (may be mangled). People like
  279. keeping pointers to this stuff */
  280. char *args;
  281. };
  282. /* FIXME: It'd be nice to isolate modules during init, too, so they
  283. aren't used before they (may) fail. But presently too much code
  284. (IDE & SCSI) require entry into the module during init.*/
  285. static inline int module_is_live(struct module *mod)
  286. {
  287. return mod->state != MODULE_STATE_GOING;
  288. }
  289. /* Is this address in a module? (second is with no locks, for oops) */
  290. struct module *module_text_address(unsigned long addr);
  291. struct module *__module_text_address(unsigned long addr);
  292. int is_module_address(unsigned long addr);
  293. /* Returns module and fills in value, defined and namebuf, or NULL if
  294. symnum out of range. */
  295. struct module *module_get_kallsym(unsigned int symnum, unsigned long *value,
  296. char *type, char *name, size_t namelen);
  297. /* Look for this name: can be of form module:name. */
  298. unsigned long module_kallsyms_lookup_name(const char *name);
  299. int is_exported(const char *name, const struct module *mod);
  300. extern void __module_put_and_exit(struct module *mod, long code)
  301. __attribute__((noreturn));
  302. #define module_put_and_exit(code) __module_put_and_exit(THIS_MODULE, code);
  303. #ifdef CONFIG_MODULE_UNLOAD
  304. unsigned int module_refcount(struct module *mod);
  305. void __symbol_put(const char *symbol);
  306. #define symbol_put(x) __symbol_put(MODULE_SYMBOL_PREFIX #x)
  307. void symbol_put_addr(void *addr);
  308. /* Sometimes we know we already have a refcount, and it's easier not
  309. to handle the error case (which only happens with rmmod --wait). */
  310. static inline void __module_get(struct module *module)
  311. {
  312. if (module) {
  313. BUG_ON(module_refcount(module) == 0);
  314. local_inc(&module->ref[get_cpu()].count);
  315. put_cpu();
  316. }
  317. }
  318. static inline int try_module_get(struct module *module)
  319. {
  320. int ret = 1;
  321. if (module) {
  322. unsigned int cpu = get_cpu();
  323. if (likely(module_is_live(module)))
  324. local_inc(&module->ref[cpu].count);
  325. else
  326. ret = 0;
  327. put_cpu();
  328. }
  329. return ret;
  330. }
  331. static inline void module_put(struct module *module)
  332. {
  333. if (module) {
  334. unsigned int cpu = get_cpu();
  335. local_dec(&module->ref[cpu].count);
  336. /* Maybe they're waiting for us to drop reference? */
  337. if (unlikely(!module_is_live(module)))
  338. wake_up_process(module->waiter);
  339. put_cpu();
  340. }
  341. }
  342. #else /*!CONFIG_MODULE_UNLOAD*/
  343. static inline int try_module_get(struct module *module)
  344. {
  345. return !module || module_is_live(module);
  346. }
  347. static inline void module_put(struct module *module)
  348. {
  349. }
  350. static inline void __module_get(struct module *module)
  351. {
  352. }
  353. #define symbol_put(x) do { } while(0)
  354. #define symbol_put_addr(p) do { } while(0)
  355. #endif /* CONFIG_MODULE_UNLOAD */
  356. /* This is a #define so the string doesn't get put in every .o file */
  357. #define module_name(mod) \
  358. ({ \
  359. struct module *__mod = (mod); \
  360. __mod ? __mod->name : "kernel"; \
  361. })
  362. #define __unsafe(mod) \
  363. do { \
  364. if (mod && !(mod)->unsafe) { \
  365. printk(KERN_WARNING \
  366. "Module %s cannot be unloaded due to unsafe usage in" \
  367. " %s:%u\n", (mod)->name, __FILE__, __LINE__); \
  368. (mod)->unsafe = 1; \
  369. } \
  370. } while(0)
  371. /* For kallsyms to ask for address resolution. NULL means not found. */
  372. const char *module_address_lookup(unsigned long addr,
  373. unsigned long *symbolsize,
  374. unsigned long *offset,
  375. char **modname);
  376. /* For extable.c to search modules' exception tables. */
  377. const struct exception_table_entry *search_module_extables(unsigned long addr);
  378. int register_module_notifier(struct notifier_block * nb);
  379. int unregister_module_notifier(struct notifier_block * nb);
  380. extern void print_modules(void);
  381. struct device_driver;
  382. void module_add_driver(struct module *, struct device_driver *);
  383. void module_remove_driver(struct device_driver *);
  384. #else /* !CONFIG_MODULES... */
  385. #define EXPORT_SYMBOL(sym)
  386. #define EXPORT_SYMBOL_GPL(sym)
  387. #define EXPORT_SYMBOL_GPL_FUTURE(sym)
  388. #define EXPORT_UNUSED_SYMBOL(sym)
  389. #define EXPORT_UNUSED_SYMBOL_GPL(sym)
  390. /* Given an address, look for it in the exception tables. */
  391. static inline const struct exception_table_entry *
  392. search_module_extables(unsigned long addr)
  393. {
  394. return NULL;
  395. }
  396. /* Is this address in a module? */
  397. static inline struct module *module_text_address(unsigned long addr)
  398. {
  399. return NULL;
  400. }
  401. /* Is this address in a module? (don't take a lock, we're oopsing) */
  402. static inline struct module *__module_text_address(unsigned long addr)
  403. {
  404. return NULL;
  405. }
  406. static inline int is_module_address(unsigned long addr)
  407. {
  408. return 0;
  409. }
  410. /* Get/put a kernel symbol (calls should be symmetric) */
  411. #define symbol_get(x) ({ extern typeof(x) x __attribute__((weak)); &(x); })
  412. #define symbol_put(x) do { } while(0)
  413. #define symbol_put_addr(x) do { } while(0)
  414. static inline void __module_get(struct module *module)
  415. {
  416. }
  417. static inline int try_module_get(struct module *module)
  418. {
  419. return 1;
  420. }
  421. static inline void module_put(struct module *module)
  422. {
  423. }
  424. #define module_name(mod) "kernel"
  425. #define __unsafe(mod)
  426. /* For kallsyms to ask for address resolution. NULL means not found. */
  427. static inline const char *module_address_lookup(unsigned long addr,
  428. unsigned long *symbolsize,
  429. unsigned long *offset,
  430. char **modname)
  431. {
  432. return NULL;
  433. }
  434. static inline struct module *module_get_kallsym(unsigned int symnum,
  435. unsigned long *value,
  436. char *type, char *name,
  437. size_t namelen)
  438. {
  439. return NULL;
  440. }
  441. static inline unsigned long module_kallsyms_lookup_name(const char *name)
  442. {
  443. return 0;
  444. }
  445. static inline int is_exported(const char *name, const struct module *mod)
  446. {
  447. return 0;
  448. }
  449. static inline int register_module_notifier(struct notifier_block * nb)
  450. {
  451. /* no events will happen anyway, so this can always succeed */
  452. return 0;
  453. }
  454. static inline int unregister_module_notifier(struct notifier_block * nb)
  455. {
  456. return 0;
  457. }
  458. #define module_put_and_exit(code) do_exit(code)
  459. static inline void print_modules(void)
  460. {
  461. }
  462. struct device_driver;
  463. struct module;
  464. static inline void module_add_driver(struct module *module, struct device_driver *driver)
  465. {
  466. }
  467. static inline void module_remove_driver(struct device_driver *driver)
  468. {
  469. }
  470. #endif /* CONFIG_MODULES */
  471. #define symbol_request(x) try_then_request_module(symbol_get(x), "symbol:" #x)
  472. /* BELOW HERE ALL THESE ARE OBSOLETE AND WILL VANISH */
  473. #define __MODULE_STRING(x) __stringify(x)
  474. #endif /* _LINUX_MODULE_H */