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 /* These are either module local, or the kernel's dummy ones. */
  48 extern int init_module(void);
  49 extern void cleanup_module(void);
  50
  51 /* Archs provide a method of finding the correct exception table. */
  52 struct exception_table_entry;
  53
  54 const struct exception_table_entry *
  55 search_extable(const struct exception_table_entry *first,
  56                const struct exception_table_entry *last,
  57                unsigned long value);
  58 void sort_extable(struct exception_table_entry *start,
  59                   struct exception_table_entry *finish);
  60 void sort_main_extable(void);
  61
  62 #ifdef MODULE
  63 #define ___module_cat(a,b) __mod_ ## a ## b
  64 #define __module_cat(a,b) ___module_cat(a,b)
  65 #define __MODULE_INFO(tag, name, info)                                    \
  66 static const char __module_cat(name,__LINE__)[]                           \
  67   __attribute_used__                                                      \
  68   __attribute__((section(".modinfo"),unused)) = __stringify(tag) "=" info
  69
  70 #define MODULE_GENERIC_TABLE(gtype,name)                        \
  71 extern const struct gtype##_id __mod_##gtype##_table            \
  72   __attribute__ ((unused, alias(__stringify(name))))
  73
  74 extern struct module __this_module;
  75 #define THIS_MODULE (&__this_module)
  76
  77 #else  /* !MODULE */
  78
  79 #define MODULE_GENERIC_TABLE(gtype,name)
  80 #define __MODULE_INFO(tag, name, info)
  81 #define THIS_MODULE ((struct module *)0)
  82 #endif
  83
  84 /* Generic info of form tag = "info" */
  85 #define MODULE_INFO(tag, info) __MODULE_INFO(tag, tag, info)
  86
  87 /* For userspace: you can also call me... */
  88 #define MODULE_ALIAS(_alias) MODULE_INFO(alias, _alias)
  89
  90 /*
  91  * The following license idents are currently accepted as indicating free
  92  * software modules
  93  *
  94  *      "GPL"                           [GNU Public License v2 or later]
  95  *      "GPL v2"                        [GNU Public License v2]
  96  *      "GPL and additional rights"     [GNU Public License v2 rights and more]
  97  *      "Dual BSD/GPL"                  [GNU Public License v2
  98  *                                       or BSD license choice]
  99  *      "Dual MPL/GPL"                  [GNU Public License v2
 100  *                                       or Mozilla license choice]
 101  *
 102  * The following other idents are available
 103  *
 104  *      "Proprietary"                   [Non free products]
 105  *
 106  * There are dual licensed components, but when running with Linux it is the
 107  * GPL that is relevant so this is a non issue. Similarly LGPL linked with GPL
 108  * is a GPL combined work.
 109  *
 110  * This exists for several reasons
 111  * 1.   So modinfo can show license info for users wanting to vet their setup
 112  *      is free
 113  * 2.   So the community can ignore bug reports including proprietary modules
 114  * 3.   So vendors can do likewise based on their own policies
 115  */
 116 #define MODULE_LICENSE(_license) MODULE_INFO(license, _license)
 117
 118 /* Author, ideally of form NAME <EMAIL>[, NAME <EMAIL>]*[ and NAME <EMAIL>] */
 119 #define MODULE_AUTHOR(_author) MODULE_INFO(author, _author)
 120
 121 /* What your module does. */
 122 #define MODULE_DESCRIPTION(_description) MODULE_INFO(description, _description)
 123
 124 /* One for each parameter, describing how to use it.  Some files do
 125    multiple of these per line, so can't just use MODULE_INFO. */
 126 #define MODULE_PARM_DESC(_parm, desc) \
 127         __MODULE_INFO(parm, _parm, #_parm ":" desc)
 128
 129 #define MODULE_DEVICE_TABLE(type,name)          \
 130   MODULE_GENERIC_TABLE(type##_device,name)
 131
 132 /* Version of form [<epoch>:]<version>[-<extra-version>].
 133    Or for CVS/RCS ID version, everything but the number is stripped.
 134   <epoch>: A (small) unsigned integer which allows you to start versions
 135            anew. If not mentioned, it's zero.  eg. "2:1.0" is after
 136            "1:2.0".
 137   <version>: The <version> may contain only alphanumerics and the
 138            character `.'.  Ordered by numeric sort for numeric parts,
 139            ascii sort for ascii parts (as per RPM or DEB algorithm).
 140   <extraversion>: Like <version>, but inserted for local
 141            customizations, eg "rh3" or "rusty1".
 142
 143   Using this automatically adds a checksum of the .c files and the
 144   local headers to the end.  Use MODULE_VERSION("") if you want just
 145   this.  Macro includes room for this.
 146 */
 147 #define MODULE_VERSION(_version) \
 148   MODULE_INFO(version, _version "\0xxxxxxxxxxxxxxxxxxxxxxxx")
 149
 150 /* Given an address, look for it in the exception tables */
 151 const struct exception_table_entry *search_exception_tables(unsigned long add);
 152
 153 struct notifier_block;
 154
 155 #ifdef CONFIG_MODULES
 156
 157 /* Get/put a kernel symbol (calls must be symmetric) */
 158 void *__symbol_get(const char *symbol);
 159 void *__symbol_get_gpl(const char *symbol);
 160 #define symbol_get(x) ((typeof(&x))(__symbol_get(MODULE_SYMBOL_PREFIX #x)))
 161
 162 #ifndef __GENKSYMS__
 163 #ifdef CONFIG_MODVERSIONS
 164 /* Mark the CRC weak since genksyms apparently decides not to
 165  * generate a checksums for some symbols */
 166 #define __CRC_SYMBOL(sym, sec)                                  \
 167         extern void *__crc_##sym __attribute__((weak));         \
 168         static const unsigned long __kcrctab_##sym              \
 169         __attribute_used__                                      \
 170         __attribute__((section("__kcrctab" sec), unused))       \
 171         = (unsigned long) &__crc_##sym;
 172 #else
 173 #define __CRC_SYMBOL(sym, sec)
 174 #endif
 175
 176 /* For every exported symbol, place a struct in the __ksymtab section */
 177 #define __EXPORT_SYMBOL(sym, sec)                               \
 178         __CRC_SYMBOL(sym, sec)                                  \
 179         static const char __kstrtab_##sym[]                     \
 180         __attribute__((section("__ksymtab_strings")))           \
 181         = MODULE_SYMBOL_PREFIX #sym;                            \
 182         static const struct kernel_symbol __ksymtab_##sym       \
 183         __attribute_used__                                      \
 184         __attribute__((section("__ksymtab" sec), unused))       \
 185         = { (unsigned long)&sym, __kstrtab_##sym }
 186
 187 #define EXPORT_SYMBOL(sym)                                      \
 188         __EXPORT_SYMBOL(sym, "")
 189
 190 #define EXPORT_SYMBOL_GPL(sym)                                  \
 191         __EXPORT_SYMBOL(sym, "_gpl")
 192
 193 #endif
 194
 195 /* We don't mangle the actual symbol anymore, so no need for
 196  * special casing EXPORT_SYMBOL_NOVERS.  FIXME: Deprecated */
 197 #define EXPORT_SYMBOL_NOVERS(sym) EXPORT_SYMBOL(sym)
 198
 199 struct module_ref
 200 {
 201         local_t count;
 202 } ____cacheline_aligned;
 203
 204 enum module_state
 205 {
 206         MODULE_STATE_LIVE,
 207         MODULE_STATE_COMING,
 208         MODULE_STATE_GOING,
 209 };
 210
 211 /* sysfs stuff */
 212 struct module_attribute
 213 {
 214         struct attribute attr;
 215         struct kernel_param *param;
 216 };
 217
 218 struct module_kobject
 219 {
 220         /* Everyone should have one of these. */
 221         struct kobject kobj;
 222
 223         /* We always have refcnt, we may have others from module_param(). */
 224         unsigned int num_attributes;
 225         struct module_attribute attr[0];
 226 };
 227
 228 /* Similar stuff for section attributes. */
 229 #define MODULE_SECT_NAME_LEN 32
 230 struct module_sect_attr
 231 {
 232         struct attribute attr;
 233         char name[MODULE_SECT_NAME_LEN];
 234         unsigned long address;
 235 };
 236
 237 struct module_sections
 238 {
 239         struct kobject kobj;
 240         struct module_sect_attr attrs[0];
 241 };
 242
 243
 244 struct module
 245 {
 246         enum module_state state;
 247
 248         /* Member of list of modules */
 249         struct list_head list;
 250
 251         /* Unique handle for this module */
 252         char name[MODULE_NAME_LEN];
 253
 254         /* Sysfs stuff. */
 255         struct module_kobject *mkobj;
 256
 257         /* Exported symbols */
 258         const struct kernel_symbol *syms;
 259         unsigned int num_syms;
 260         const unsigned long *crcs;
 261
 262         /* GPL-only exported symbols. */
 263         const struct kernel_symbol *gpl_syms;
 264         unsigned int num_gpl_syms;
 265         const unsigned long *gpl_crcs;
 266
 267         /* Exception table */
 268         unsigned int num_exentries;
 269         const struct exception_table_entry *extable;
 270
 271         /* Startup function. */
 272         int (*init)(void);
 273
 274         /* If this is non-NULL, vfree after init() returns */
 275         void *module_init;
 276
 277         /* Here is the actual code + data, vfree'd on unload. */
 278         void *module_core;
 279
 280         /* Here are the sizes of the init and core sections */
 281         unsigned long init_size, core_size;
 282
 283         /* The size of the executable code in each section.  */
 284         unsigned long init_text_size, core_text_size;
 285
 286         /* Arch-specific module values */
 287         struct mod_arch_specific arch;
 288
 289         /* Am I unsafe to unload? */
 290         int unsafe;
 291
 292         /* Am I GPL-compatible */
 293         int license_gplok;
 294
 295 #ifdef CONFIG_MODULE_UNLOAD
 296         /* Reference counts */
 297         struct module_ref ref[NR_CPUS];
 298
 299         /* What modules depend on me? */
 300         struct list_head modules_which_use_me;
 301
 302         /* Who is waiting for us to be unloaded */
 303         struct task_struct *waiter;
 304
 305         /* Destruction function. */
 306         void (*exit)(void);
 307
 308         /* Fake kernel param for refcnt. */
 309         struct kernel_param refcnt_param;
 310 #endif
 311
 312 #ifdef CONFIG_KALLSYMS
 313         /* We keep the symbol and string tables for kallsyms. */
 314         Elf_Sym *symtab;
 315         unsigned long num_symtab;
 316         char *strtab;
 317
 318         /* Section attributes */
 319         struct module_sections *sect_attrs;
 320 #endif
 321
 322         /* Per-cpu data. */
 323         void *percpu;
 324
 325         /* The command line arguments (may be mangled).  People like
 326            keeping pointers to this stuff */
 327         char *args;
 328 };
 329
 330 /* FIXME: It'd be nice to isolate modules during init, too, so they
 331    aren't used before they (may) fail.  But presently too much code
 332    (IDE & SCSI) require entry into the module during init.*/
 333 static inline int module_is_live(struct module *mod)
 334 {
 335         return mod->state != MODULE_STATE_GOING;
 336 }
 337
 338 /* Is this address in a module? (second is with no locks, for oops) */
 339 struct module *module_text_address(unsigned long addr);
 340 struct module *__module_text_address(unsigned long addr);
 341
 342 /* Returns module and fills in value, defined and namebuf, or NULL if
 343    symnum out of range. */
 344 struct module *module_get_kallsym(unsigned int symnum,
 345                                   unsigned long *value,
 346                                   char *type,
 347                                   char namebuf[128]);
 348
 349 /* Look for this name: can be of form module:name. */
 350 unsigned long module_kallsyms_lookup_name(const char *name);
 351
 352 int is_exported(const char *name, const struct module *mod);
 353
 354 extern void __module_put_and_exit(struct module *mod, long code)
 355         __attribute__((noreturn));
 356 #define module_put_and_exit(code) __module_put_and_exit(THIS_MODULE, code);
 357
 358 #ifdef CONFIG_MODULE_UNLOAD
 359 unsigned int module_refcount(struct module *mod);
 360 void __symbol_put(const char *symbol);
 361 #define symbol_put(x) __symbol_put(MODULE_SYMBOL_PREFIX #x)
 362 void symbol_put_addr(void *addr);
 363
 364 /* Sometimes we know we already have a refcount, and it's easier not
 365    to handle the error case (which only happens with rmmod --wait). */
 366 static inline void __module_get(struct module *module)
 367 {
 368         if (module) {
 369                 BUG_ON(module_refcount(module) == 0);
 370                 local_inc(&module->ref[get_cpu()].count);
 371                 put_cpu();
 372         }
 373 }
 374
 375 static inline int try_module_get(struct module *module)
 376 {
 377         int ret = 1;
 378
 379         if (module) {
 380                 unsigned int cpu = get_cpu();
 381                 if (likely(module_is_live(module)))
 382                         local_inc(&module->ref[cpu].count);
 383                 else
 384                         ret = 0;
 385                 put_cpu();
 386         }
 387         return ret;
 388 }
 389
 390 static inline void module_put(struct module *module)
 391 {
 392         if (module) {
 393                 unsigned int cpu = get_cpu();
 394                 local_dec(&module->ref[cpu].count);
 395                 /* Maybe they're waiting for us to drop reference? */
 396                 if (unlikely(!module_is_live(module)))
 397                         wake_up_process(module->waiter);
 398                 put_cpu();
 399         }
 400 }
 401
 402 #else /*!CONFIG_MODULE_UNLOAD*/
 403 static inline int try_module_get(struct module *module)
 404 {
 405         return !module || module_is_live(module);
 406 }
 407 static inline void module_put(struct module *module)
 408 {
 409 }
 410 static inline void __module_get(struct module *module)
 411 {
 412 }
 413 #define symbol_put(x) do { } while(0)
 414 #define symbol_put_addr(p) do { } while(0)
 415
 416 #endif /* CONFIG_MODULE_UNLOAD */
 417
 418 /* This is a #define so the string doesn't get put in every .o file */
 419 #define module_name(mod)                        \
 420 ({                                              \
 421         struct module *__mod = (mod);           \
 422         __mod ? __mod->name : "kernel";         \
 423 })
 424
 425 #define __unsafe(mod)                                                        \
 426 do {                                                                         \
 427         if (mod && !(mod)->unsafe) {                                         \
 428                 printk(KERN_WARNING                                          \
 429                        "Module %s cannot be unloaded due to unsafe usage in" \
 430                        " %s:%u\n", (mod)->name, __FILE__, __LINE__);         \
 431                 (mod)->unsafe = 1;                                           \
 432         }                                                                    \
 433 } while(0)
 434
 435 /* For kallsyms to ask for address resolution.  NULL means not found. */
 436 const char *module_address_lookup(unsigned long addr,
 437                                   unsigned long *symbolsize,
 438                                   unsigned long *offset,
 439                                   char **modname);
 440
 441 /* For extable.c to search modules' exception tables. */
 442 const struct exception_table_entry *search_module_extables(unsigned long addr);
 443
 444 int register_module_notifier(struct notifier_block * nb);
 445 int unregister_module_notifier(struct notifier_block * nb);
 446
 447 extern void print_modules(void);
 448 #else /* !CONFIG_MODULES... */
 449 #define EXPORT_SYMBOL(sym)
 450 #define EXPORT_SYMBOL_GPL(sym)
 451 #define EXPORT_SYMBOL_NOVERS(sym)
 452
 453 /* Given an address, look for it in the exception tables. */
 454 static inline const struct exception_table_entry *
 455 search_module_extables(unsigned long addr)
 456 {
 457         return NULL;
 458 }
 459
 460 /* Is this address in a module? */
 461 static inline struct module *module_text_address(unsigned long addr)
 462 {
 463         return NULL;
 464 }
 465
 466 /* Is this address in a module? (don't take a lock, we're oopsing) */
 467 static inline struct module *__module_text_address(unsigned long addr)
 468 {
 469         return NULL;
 470 }
 471
 472 /* Get/put a kernel symbol (calls should be symmetric) */
 473 #define symbol_get(x) ({ extern typeof(x) x __attribute__((weak)); &(x); })
 474 #define symbol_put(x) do { } while(0)
 475 #define symbol_put_addr(x) do { } while(0)
 476
 477 static inline void __module_get(struct module *module)
 478 {
 479 }
 480
 481 static inline int try_module_get(struct module *module)
 482 {
 483         return 1;
 484 }
 485
 486 static inline void module_put(struct module *module)
 487 {
 488 }
 489
 490 #define module_name(mod) "kernel"
 491
 492 #define __unsafe(mod)
 493
 494 /* For kallsyms to ask for address resolution.  NULL means not found. */
 495 static inline const char *module_address_lookup(unsigned long addr,
 496                                                 unsigned long *symbolsize,
 497                                                 unsigned long *offset,
 498                                                 char **modname)
 499 {
 500         return NULL;
 501 }
 502
 503 static inline struct module *module_get_kallsym(unsigned int symnum,
 504                                                 unsigned long *value,
 505                                                 char *type,
 506                                                 char namebuf[128])
 507 {
 508         return NULL;
 509 }
 510
 511 static inline unsigned long module_kallsyms_lookup_name(const char *name)
 512 {
 513         return 0;
 514 }
 515
 516 static inline int is_exported(const char *name, const struct module *mod)
 517 {
 518         return 0;
 519 }
 520
 521 static inline int register_module_notifier(struct notifier_block * nb)
 522 {
 523         /* no events will happen anyway, so this can always succeed */
 524         return 0;
 525 }
 526
 527 static inline int unregister_module_notifier(struct notifier_block * nb)
 528 {
 529         return 0;
 530 }
 531
 532 #define module_put_and_exit(code) do_exit(code)
 533
 534 static inline void print_modules(void)
 535 {
 536 }
 537 #endif /* CONFIG_MODULES */
 538
 539 #define symbol_request(x) try_then_request_module(symbol_get(x), "symbol:" #x)
 540
 541 /* BELOW HERE ALL THESE ARE OBSOLETE AND WILL VANISH */
 542
 543 struct obsolete_modparm {
 544         char name[64];
 545         char type[64-sizeof(void *)];
 546         void *addr;
 547 };
 548 #ifdef MODULE
 549 /* DEPRECATED: Do not use. */
 550 #define MODULE_PARM(var,type)                                               \
 551 struct obsolete_modparm __parm_##var __attribute__((section("__obsparm"))) = \
 552 { __stringify(var), type };
 553
 554 static inline void __deprecated MOD_INC_USE_COUNT(struct module *module)
 555 {
 556         __unsafe(module);
 557
 558 #if defined(CONFIG_MODULE_UNLOAD) && defined(MODULE)
 559         local_inc(&module->ref[get_cpu()].count);
 560         put_cpu();
 561 #else
 562         (void)try_module_get(module);
 563 #endif
 564 }
 565
 566 static inline void __deprecated MOD_DEC_USE_COUNT(struct module *module)
 567 {
 568         module_put(module);
 569 }
 570
 571 #define MOD_INC_USE_COUNT       MOD_INC_USE_COUNT(THIS_MODULE)
 572 #define MOD_DEC_USE_COUNT       MOD_DEC_USE_COUNT(THIS_MODULE)
 573 #else
 574 #define MODULE_PARM(var,type)
 575 #define MOD_INC_USE_COUNT       do { } while (0)
 576 #define MOD_DEC_USE_COUNT       do { } while (0)
 577 #endif
 578
 579 #define __MODULE_STRING(x) __stringify(x)
 580
 581 /* Use symbol_get and symbol_put instead.  You'll thank me. */
 582 #define HAVE_INTER_MODULE
 583 extern void inter_module_register(const char *, struct module *, const void *);
 584 extern void inter_module_unregister(const char *);
 585 extern const void *inter_module_get(const char *);
 586 extern const void *inter_module_get_request(const char *, const char *);
 587 extern void inter_module_put(const char *);
 588
 589 #endif /* _LINUX_MODULE_H */