include/linux/module.h

   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
  23 #include <asm/module.h>
  24
  25 /* Not Yet Implemented */
  26 #define MODULE_SUPPORTED_DEVICE(name)
  27
  28 /* v850 toolchain uses a `_' prefix for all user symbols */
  29 #ifndef MODULE_SYMBOL_PREFIX
  30 #define MODULE_SYMBOL_PREFIX ""
  31 #endif
  32
  33 #define MODULE_NAME_LEN (64 - sizeof(unsigned long))
  34
  35 struct kernel_symbol
  36 {
  37         unsigned long value;
  38         const char *name;
  39 };
  40
  41 struct modversion_info
  42 {
  43         unsigned long crc;
  44         char name[MODULE_NAME_LEN];
  45 };
  46
  47 struct module;
  48
  49 struct module_attribute {
  50         struct attribute attr;
  51         ssize_t (*show)(struct module_attribute *, struct module *, char *);
  52         ssize_t (*store)(struct module_attribute *, struct module *,
  53                          const char *, size_t count);
  54 };
  55
  56 struct module_kobject
  57 {
  58         struct kobject kobj;
  59         struct module *mod;
  60 };
  61
  62 /* These are either module local, or the kernel's dummy ones. */
  63 extern int init_module(void);
  64 extern void cleanup_module(void);
  65
  66 /* Archs provide a method of finding the correct exception table. */
  67 struct exception_table_entry;
  68
  69 const struct exception_table_entry *
  70 search_extable(const struct exception_table_entry *first,
  71                const struct exception_table_entry *last,
  72                unsigned long value);
  73 void sort_extable(struct exception_table_entry *start,
  74                   struct exception_table_entry *finish);
  75 void sort_main_extable(void);
  76
  77 extern struct subsystem module_subsys;
  78
  79 #ifdef MODULE
  80 #define MODULE_GENERIC_TABLE(gtype,name)                        \
  81 extern const struct gtype##_id __mod_##gtype##_table            \
  82   __attribute__ ((unused, alias(__stringify(name))))
  83
  84 extern struct module __this_module;
  85 #define THIS_MODULE (&__this_module)
  86 #else  /* !MODULE */
  87 #define MODULE_GENERIC_TABLE(gtype,name)
  88 #define THIS_MODULE ((struct module *)0)
  89 #endif
  90
  91 /* Generic info of form tag = "info" */
  92 #define MODULE_INFO(tag, info) __MODULE_INFO(tag, tag, info)
  93
  94 /* For userspace: you can also call me... */
  95 #define MODULE_ALIAS(_alias) MODULE_INFO(alias, _alias)
  96
  97 /*
  98  * The following license idents are currently accepted as indicating free
  99  * software modules
 100  *
 101  *      "GPL"                           [GNU Public License v2 or later]
 102  *      "GPL v2"                        [GNU Public License v2]
 103  *      "GPL and additional rights"     [GNU Public License v2 rights and more]
 104  *      "Dual BSD/GPL"                  [GNU Public License v2
 105  *                                       or BSD license choice]
 106  *      "Dual MPL/GPL"                  [GNU Public License v2
 107  *                                       or Mozilla license choice]
 108  *
 109  * The following other idents are available
 110  *
 111  *      "Proprietary"                   [Non free products]
 112  *
 113  * There are dual licensed components, but when running with Linux it is the
 114  * GPL that is relevant so this is a non issue. Similarly LGPL linked with GPL
 115  * is a GPL combined work.
 116  *
 117  * This exists for several reasons
 118  * 1.   So modinfo can show license info for users wanting to vet their setup
 119  *      is free
 120  * 2.   So the community can ignore bug reports including proprietary modules
 121  * 3.   So vendors can do likewise based on their own policies
 122  */
 123 #define MODULE_LICENSE(_license) MODULE_INFO(license, _license)
 124
 125 /* Author, ideally of form NAME <EMAIL>[, NAME <EMAIL>]*[ and NAME <EMAIL>] */
 126 #define MODULE_AUTHOR(_author) MODULE_INFO(author, _author)
 127
 128 /* What your module does. */
 129 #define MODULE_DESCRIPTION(_description) MODULE_INFO(description, _description)
 130
 131 /* One for each parameter, describing how to use it.  Some files do
 132    multiple of these per line, so can't just use MODULE_INFO. */
 133 #define MODULE_PARM_DESC(_parm, desc) \
 134         __MODULE_INFO(parm, _parm, #_parm ":" desc)
 135
 136 #define MODULE_DEVICE_TABLE(type,name)          \
 137   MODULE_GENERIC_TABLE(type##_device,name)
 138
 139 /* Version of form [<epoch>:]<version>[-<extra-version>].
 140    Or for CVS/RCS ID version, everything but the number is stripped.
 141   <epoch>: A (small) unsigned integer which allows you to start versions
 142            anew. If not mentioned, it's zero.  eg. "2:1.0" is after
 143            "1:2.0".
 144   <version>: The <version> may contain only alphanumerics and the
 145            character `.'.  Ordered by numeric sort for numeric parts,
 146            ascii sort for ascii parts (as per RPM or DEB algorithm).
 147   <extraversion>: Like <version>, but inserted for local
 148            customizations, eg "rh3" or "rusty1".
 149
 150   Using this automatically adds a checksum of the .c files and the
 151   local headers in "srcversion".
 152 */
 153 #define MODULE_VERSION(_version) MODULE_INFO(version, _version)
 154
 155 /* Given an address, look for it in the exception tables */
 156 const struct exception_table_entry *search_exception_tables(unsigned long add);
 157
 158 struct notifier_block;
 159
 160 #ifdef CONFIG_MODULES
 161
 162 /* Get/put a kernel symbol (calls must be symmetric) */
 163 void *__symbol_get(const char *symbol);
 164 void *__symbol_get_gpl(const char *symbol);
 165 #define symbol_get(x) ((typeof(&x))(__symbol_get(MODULE_SYMBOL_PREFIX #x)))
 166
 167 #ifndef __GENKSYMS__
 168 #ifdef CONFIG_MODVERSIONS
 169 /* Mark the CRC weak since genksyms apparently decides not to
 170  * generate a checksums for some symbols */
 171 #define __CRC_SYMBOL(sym, sec)                                  \
 172         extern void *__crc_##sym __attribute__((weak));         \
 173         static const unsigned long __kcrctab_##sym              \
 174         __attribute_used__                                      \
 175         __attribute__((section("__kcrctab" sec), unused))       \
 176         = (unsigned long) &__crc_##sym;
 177 #else
 178 #define __CRC_SYMBOL(sym, sec)
 179 #endif
 180
 181 /* For every exported symbol, place a struct in the __ksymtab section */
 182 #define __EXPORT_SYMBOL(sym, sec)                               \
 183         __CRC_SYMBOL(sym, sec)                                  \
 184         static const char __kstrtab_##sym[]                     \
 185         __attribute__((section("__ksymtab_strings")))           \
 186         = MODULE_SYMBOL_PREFIX #sym;                            \
 187         static const struct kernel_symbol __ksymtab_##sym       \
 188         __attribute_used__                                      \
 189         __attribute__((section("__ksymtab" sec), unused))       \
 190         = { (unsigned long)&sym, __kstrtab_##sym }
 191
 192 #define EXPORT_SYMBOL(sym)                                      \
 193         __EXPORT_SYMBOL(sym, "")
 194
 195 #define EXPORT_SYMBOL_GPL(sym)                                  \
 196         __EXPORT_SYMBOL(sym, "_gpl")
 197
 198 #endif
 199
 200 struct module_ref
 201 {
 202         local_t count;
 203 } ____cacheline_aligned;
 204
 205 enum module_state
 206 {
 207         MODULE_STATE_LIVE,
 208         MODULE_STATE_COMING,
 209         MODULE_STATE_GOING,
 210 };
 211
 212 /* Similar stuff for section attributes. */
 213 #define MODULE_SECT_NAME_LEN 32
 214 struct module_sect_attr
 215 {
 216         struct module_attribute mattr;
 217         char name[MODULE_SECT_NAME_LEN];
 218         unsigned long address;
 219 };
 220
 221 struct module_sect_attrs
 222 {
 223         struct attribute_group grp;
 224         struct module_sect_attr attrs[0];
 225 };
 226
 227 struct module_param_attrs;
 228
 229 struct module
 230 {
 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_param_attrs *param_attrs;
 242
 243         /* Exported symbols */
 244         const struct kernel_symbol *syms;
 245         unsigned int num_syms;
 246         const unsigned long *crcs;
 247
 248         /* GPL-only exported symbols. */
 249         const struct kernel_symbol *gpl_syms;
 250         unsigned int num_gpl_syms;
 251         const unsigned long *gpl_crcs;
 252
 253         /* Exception table */
 254         unsigned int num_exentries;
 255         const struct exception_table_entry *extable;
 256
 257         /* Startup function. */
 258         int (*init)(void);
 259
 260         /* If this is non-NULL, vfree after init() returns */
 261         void *module_init;
 262
 263         /* Here is the actual code + data, vfree'd on unload. */
 264         void *module_core;
 265
 266         /* Here are the sizes of the init and core sections */
 267         unsigned long init_size, core_size;
 268
 269         /* The size of the executable code in each section.  */
 270         unsigned long init_text_size, core_text_size;
 271
 272         /* Arch-specific module values */
 273         struct mod_arch_specific arch;
 274
 275         /* Am I unsafe to unload? */
 276         int unsafe;
 277
 278         /* Am I GPL-compatible */
 279         int license_gplok;
 280
 281 #ifdef CONFIG_MODULE_UNLOAD
 282         /* Reference counts */
 283         struct module_ref ref[NR_CPUS];
 284
 285         /* What modules depend on me? */
 286         struct list_head modules_which_use_me;
 287
 288         /* Who is waiting for us to be unloaded */
 289         struct task_struct *waiter;
 290
 291         /* Destruction function. */
 292         void (*exit)(void);
 293 #endif
 294
 295 #ifdef CONFIG_KALLSYMS
 296         /* We keep the symbol and string tables for kallsyms. */
 297         Elf_Sym *symtab;
 298         unsigned long num_symtab;
 299         char *strtab;
 300
 301         /* Section attributes */
 302         struct module_sect_attrs *sect_attrs;
 303 #endif
 304
 305         /* Per-cpu data. */
 306         void *percpu;
 307
 308         /* The command line arguments (may be mangled).  People like
 309            keeping pointers to this stuff */
 310         char *args;
 311 };
 312
 313 /* FIXME: It'd be nice to isolate modules during init, too, so they
 314    aren't used before they (may) fail.  But presently too much code
 315    (IDE & SCSI) require entry into the module during init.*/
 316 static inline int module_is_live(struct module *mod)
 317 {
 318         return mod->state != MODULE_STATE_GOING;
 319 }
 320
 321 /* Is this address in a module? (second is with no locks, for oops) */
 322 struct module *module_text_address(unsigned long addr);
 323 struct module *__module_text_address(unsigned long addr);
 324
 325 /* Returns module and fills in value, defined and namebuf, or NULL if
 326    symnum out of range. */
 327 struct module *module_get_kallsym(unsigned int symnum,
 328                                   unsigned long *value,
 329                                   char *type,
 330                                   char namebuf[128]);
 331
 332 /* Look for this name: can be of form module:name. */
 333 unsigned long module_kallsyms_lookup_name(const char *name);
 334
 335 int is_exported(const char *name, const struct module *mod);
 336
 337 extern void __module_put_and_exit(struct module *mod, long code)
 338         __attribute__((noreturn));
 339 #define module_put_and_exit(code) __module_put_and_exit(THIS_MODULE, code);
 340
 341 #ifdef CONFIG_MODULE_UNLOAD
 342 unsigned int module_refcount(struct module *mod);
 343 void __symbol_put(const char *symbol);
 344 #define symbol_put(x) __symbol_put(MODULE_SYMBOL_PREFIX #x)
 345 void symbol_put_addr(void *addr);
 346
 347 /* Sometimes we know we already have a refcount, and it's easier not
 348    to handle the error case (which only happens with rmmod --wait). */
 349 static inline void __module_get(struct module *module)
 350 {
 351         if (module) {
 352                 BUG_ON(module_refcount(module) == 0);
 353                 local_inc(&module->ref[get_cpu()].count);
 354                 put_cpu();
 355         }
 356 }
 357
 358 static inline int try_module_get(struct module *module)
 359 {
 360         int ret = 1;
 361
 362         if (module) {
 363                 unsigned int cpu = get_cpu();
 364                 if (likely(module_is_live(module)))
 365                         local_inc(&module->ref[cpu].count);
 366                 else
 367                         ret = 0;
 368                 put_cpu();
 369         }
 370         return ret;
 371 }
 372
 373 static inline void module_put(struct module *module)
 374 {
 375         if (module) {
 376                 unsigned int cpu = get_cpu();
 377                 local_dec(&module->ref[cpu].count);
 378                 /* Maybe they're waiting for us to drop reference? */
 379                 if (unlikely(!module_is_live(module)))
 380                         wake_up_process(module->waiter);
 381                 put_cpu();
 382         }
 383 }
 384
 385 #else /*!CONFIG_MODULE_UNLOAD*/
 386 static inline int try_module_get(struct module *module)
 387 {
 388         return !module || module_is_live(module);
 389 }
 390 static inline void module_put(struct module *module)
 391 {
 392 }
 393 static inline void __module_get(struct module *module)
 394 {
 395 }
 396 #define symbol_put(x) do { } while(0)
 397 #define symbol_put_addr(p) do { } while(0)
 398
 399 #endif /* CONFIG_MODULE_UNLOAD */
 400
 401 /* This is a #define so the string doesn't get put in every .o file */
 402 #define module_name(mod)                        \
 403 ({                                              \
 404         struct module *__mod = (mod);           \
 405         __mod ? __mod->name : "kernel";         \
 406 })
 407
 408 #define __unsafe(mod)                                                        \
 409 do {                                                                         \
 410         if (mod && !(mod)->unsafe) {                                         \
 411                 printk(KERN_WARNING                                          \
 412                        "Module %s cannot be unloaded due to unsafe usage in" \
 413                        " %s:%u\n", (mod)->name, __FILE__, __LINE__);         \
 414                 (mod)->unsafe = 1;                                           \
 415         }                                                                    \
 416 } while(0)
 417
 418 /* For kallsyms to ask for address resolution.  NULL means not found. */
 419 const char *module_address_lookup(unsigned long addr,
 420                                   unsigned long *symbolsize,
 421                                   unsigned long *offset,
 422                                   char **modname);
 423
 424 /* For extable.c to search modules' exception tables. */
 425 const struct exception_table_entry *search_module_extables(unsigned long addr);
 426
 427 int register_module_notifier(struct notifier_block * nb);
 428 int unregister_module_notifier(struct notifier_block * nb);
 429
 430 extern void print_modules(void);
 431
 432 struct device_driver;
 433 void module_add_driver(struct module *, struct device_driver *);
 434 void module_remove_driver(struct device_driver *);
 435
 436 #else /* !CONFIG_MODULES... */
 437 #define EXPORT_SYMBOL(sym)
 438 #define EXPORT_SYMBOL_GPL(sym)
 439
 440 /* Given an address, look for it in the exception tables. */
 441 static inline const struct exception_table_entry *
 442 search_module_extables(unsigned long addr)
 443 {
 444         return NULL;
 445 }
 446
 447 /* Is this address in a module? */
 448 static inline struct module *module_text_address(unsigned long addr)
 449 {
 450         return NULL;
 451 }
 452
 453 /* Is this address in a module? (don't take a lock, we're oopsing) */
 454 static inline struct module *__module_text_address(unsigned long addr)
 455 {
 456         return NULL;
 457 }
 458
 459 /* Get/put a kernel symbol (calls should be symmetric) */
 460 #define symbol_get(x) ({ extern typeof(x) x __attribute__((weak)); &(x); })
 461 #define symbol_put(x) do { } while(0)
 462 #define symbol_put_addr(x) do { } while(0)
 463
 464 static inline void __module_get(struct module *module)
 465 {
 466 }
 467
 468 static inline int try_module_get(struct module *module)
 469 {
 470         return 1;
 471 }
 472
 473 static inline void module_put(struct module *module)
 474 {
 475 }
 476
 477 #define module_name(mod) "kernel"
 478
 479 #define __unsafe(mod)
 480
 481 /* For kallsyms to ask for address resolution.  NULL means not found. */
 482 static inline const char *module_address_lookup(unsigned long addr,
 483                                                 unsigned long *symbolsize,
 484                                                 unsigned long *offset,
 485                                                 char **modname)
 486 {
 487         return NULL;
 488 }
 489
 490 static inline struct module *module_get_kallsym(unsigned int symnum,
 491                                                 unsigned long *value,
 492                                                 char *type,
 493                                                 char namebuf[128])
 494 {
 495         return NULL;
 496 }
 497
 498 static inline unsigned long module_kallsyms_lookup_name(const char *name)
 499 {
 500         return 0;
 501 }
 502
 503 static inline int is_exported(const char *name, const struct module *mod)
 504 {
 505         return 0;
 506 }
 507
 508 static inline int register_module_notifier(struct notifier_block * nb)
 509 {
 510         /* no events will happen anyway, so this can always succeed */
 511         return 0;
 512 }
 513
 514 static inline int unregister_module_notifier(struct notifier_block * nb)
 515 {
 516         return 0;
 517 }
 518
 519 #define module_put_and_exit(code) do_exit(code)
 520
 521 static inline void print_modules(void)
 522 {
 523 }
 524
 525 struct device_driver;
 526 struct module;
 527
 528 static inline void module_add_driver(struct module *module, struct device_driver *driver)
 529 {
 530 }
 531
 532 static inline void module_remove_driver(struct device_driver *driver)
 533 {
 534 }
 535
 536 #endif /* CONFIG_MODULES */
 537
 538 #define symbol_request(x) try_then_request_module(symbol_get(x), "symbol:" #x)
 539
 540 /* BELOW HERE ALL THESE ARE OBSOLETE AND WILL VANISH */
 541
 542 struct obsolete_modparm {
 543         char name[64];
 544         char type[64-sizeof(void *)];
 545         void *addr;
 546 };
 547
 548 static inline void MODULE_PARM_(void) { }
 549 #ifdef MODULE
 550 /* DEPRECATED: Do not use. */
 551 #define MODULE_PARM(var,type)                                               \
 552 struct obsolete_modparm __parm_##var __attribute__((section("__obsparm"))) = \
 553 { __stringify(var), type, &MODULE_PARM_ }; \
 554 __MODULE_PARM_TYPE(var, type);
 555 #else
 556 #define MODULE_PARM(var,type) static void __attribute__((__unused__)) *__parm_##var = &MODULE_PARM_;
 557 #endif
 558
 559 #define __MODULE_STRING(x) __stringify(x)
 560
 561 /* Use symbol_get and symbol_put instead.  You'll thank me. */
 562 #define HAVE_INTER_MODULE
 563 extern void __deprecated inter_module_register(const char *,
 564                 struct module *, const void *);
 565 extern void __deprecated inter_module_unregister(const char *);
 566 extern const void * __deprecated inter_module_get_request(const char *,
 567                 const char *);
 568 extern void __deprecated inter_module_put(const char *);
 569
 570 #endif /* _LINUX_MODULE_H */