linux/include/linux/module.h
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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
  22#include <asm/module.h>
  23
  24/* Not Yet Implemented */
  25#define MODULE_SUPPORTED_DEVICE(name)
  26
  27/* v850 toolchain uses a `_' prefix for all user symbols */
  28#ifndef MODULE_SYMBOL_PREFIX
  29#define MODULE_SYMBOL_PREFIX ""
  30#endif
  31
  32#define MODULE_NAME_LEN (64 - sizeof(unsigned long))
  33
  34struct kernel_symbol
  35{
  36        unsigned long value;
  37        const char *name;
  38};
  39
  40struct modversion_info
  41{
  42        unsigned long crc;
  43        char name[MODULE_NAME_LEN];
  44};
  45
  46struct module;
  47
  48struct module_attribute {
  49        struct attribute attr;
  50        ssize_t (*show)(struct module_attribute *, struct module *, char *);
  51        ssize_t (*store)(struct module_attribute *, struct module *,
  52                         const char *, size_t count);
  53        void (*setup)(struct module *, const char *);
  54        int (*test)(struct module *);
  55        void (*free)(struct module *);
  56};
  57
  58struct module_kobject
  59{
  60        struct kobject kobj;
  61        struct module *mod;
  62};
  63
  64/* These are either module local, or the kernel's dummy ones. */
  65extern int init_module(void);
  66extern void cleanup_module(void);
  67
  68/* Archs provide a method of finding the correct exception table. */
  69struct exception_table_entry;
  70
  71const struct exception_table_entry *
  72search_extable(const struct exception_table_entry *first,
  73               const struct exception_table_entry *last,
  74               unsigned long value);
  75void sort_extable(struct exception_table_entry *start,
  76                  struct exception_table_entry *finish);
  77void sort_main_extable(void);
  78
  79extern struct subsystem module_subsys;
  80
  81#ifdef MODULE
  82#define MODULE_GENERIC_TABLE(gtype,name)                        \
  83extern const struct gtype##_id __mod_##gtype##_table            \
  84  __attribute__ ((unused, alias(__stringify(name))))
  85
  86extern struct module __this_module;
  87#define THIS_MODULE (&__this_module)
  88#else  /* !MODULE */
  89#define MODULE_GENERIC_TABLE(gtype,name)
  90#define THIS_MODULE ((struct module *)0)
  91#endif
  92
  93/* Generic info of form tag = "info" */
  94#define MODULE_INFO(tag, info) __MODULE_INFO(tag, tag, info)
  95
  96/* For userspace: you can also call me... */
  97#define MODULE_ALIAS(_alias) MODULE_INFO(alias, _alias)
  98
  99/*
 100 * The following license idents are currently accepted as indicating free
 101 * software modules
 102 *
 103 *      "GPL"                           [GNU Public License v2 or later]
 104 *      "GPL v2"                        [GNU Public License v2]
 105 *      "GPL and additional rights"     [GNU Public License v2 rights and more]
 106 *      "Dual BSD/GPL"                  [GNU Public License v2
 107 *                                       or BSD license choice]
 108 *      "Dual MIT/GPL"                  [GNU Public License v2
 109 *                                       or MIT license choice]
 110 *      "Dual MPL/GPL"                  [GNU Public License v2
 111 *                                       or Mozilla license choice]
 112 *
 113 * The following other idents are available
 114 *
 115 *      "Proprietary"                   [Non free products]
 116 *
 117 * There are dual licensed components, but when running with Linux it is the
 118 * GPL that is relevant so this is a non issue. Similarly LGPL linked with GPL
 119 * is a GPL combined work.
 120 *
 121 * This exists for several reasons
 122 * 1.   So modinfo can show license info for users wanting to vet their setup 
 123 *      is free
 124 * 2.   So the community can ignore bug reports including proprietary modules
 125 * 3.   So vendors can do likewise based on their own policies
 126 */
 127#define MODULE_LICENSE(_license) MODULE_INFO(license, _license)
 128
 129/* Author, ideally of form NAME <EMAIL>[, NAME <EMAIL>]*[ and NAME <EMAIL>] */
 130#define MODULE_AUTHOR(_author) MODULE_INFO(author, _author)
 131  
 132/* What your module does. */
 133#define MODULE_DESCRIPTION(_description) MODULE_INFO(description, _description)
 134
 135/* One for each parameter, describing how to use it.  Some files do
 136   multiple of these per line, so can't just use MODULE_INFO. */
 137#define MODULE_PARM_DESC(_parm, desc) \
 138        __MODULE_INFO(parm, _parm, #_parm ":" desc)
 139
 140#define MODULE_DEVICE_TABLE(type,name)          \
 141  MODULE_GENERIC_TABLE(type##_device,name)
 142
 143/* Version of form [<epoch>:]<version>[-<extra-version>].
 144   Or for CVS/RCS ID version, everything but the number is stripped.
 145  <epoch>: A (small) unsigned integer which allows you to start versions
 146           anew. If not mentioned, it's zero.  eg. "2:1.0" is after
 147           "1:2.0".
 148  <version>: The <version> may contain only alphanumerics and the
 149           character `.'.  Ordered by numeric sort for numeric parts,
 150           ascii sort for ascii parts (as per RPM or DEB algorithm).
 151  <extraversion>: Like <version>, but inserted for local
 152           customizations, eg "rh3" or "rusty1".
 153
 154  Using this automatically adds a checksum of the .c files and the
 155  local headers in "srcversion".
 156*/
 157#define MODULE_VERSION(_version) MODULE_INFO(version, _version)
 158
 159/* Given an address, look for it in the exception tables */
 160const struct exception_table_entry *search_exception_tables(unsigned long add);
 161
 162struct notifier_block;
 163
 164#ifdef CONFIG_MODULES
 165
 166/* Get/put a kernel symbol (calls must be symmetric) */
 167void *__symbol_get(const char *symbol);
 168void *__symbol_get_gpl(const char *symbol);
 169#define symbol_get(x) ((typeof(&x))(__symbol_get(MODULE_SYMBOL_PREFIX #x)))
 170
 171#ifndef __GENKSYMS__
 172#ifdef CONFIG_MODVERSIONS
 173/* Mark the CRC weak since genksyms apparently decides not to
 174 * generate a checksums for some symbols */
 175#define __CRC_SYMBOL(sym, sec)                                  \
 176        extern void *__crc_##sym __attribute__((weak));         \
 177        static const unsigned long __kcrctab_##sym              \
 178        __attribute_used__                                      \
 179        __attribute__((section("__kcrctab" sec), unused))       \
 180        = (unsigned long) &__crc_##sym;
 181#else
 182#define __CRC_SYMBOL(sym, sec)
 183#endif
 184
 185/* For every exported symbol, place a struct in the __ksymtab section */
 186#define __EXPORT_SYMBOL(sym, sec)                               \
 187        extern typeof(sym) sym;                                 \
 188        __CRC_SYMBOL(sym, sec)                                  \
 189        static const char __kstrtab_##sym[]                     \
 190        __attribute__((section("__ksymtab_strings")))           \
 191        = MODULE_SYMBOL_PREFIX #sym;                            \
 192        static const struct kernel_symbol __ksymtab_##sym       \
 193        __attribute_used__                                      \
 194        __attribute__((section("__ksymtab" sec), unused))       \
 195        = { (unsigned long)&sym, __kstrtab_##sym }
 196
 197#define EXPORT_SYMBOL(sym)                                      \
 198        __EXPORT_SYMBOL(sym, "")
 199
 200#define EXPORT_SYMBOL_GPL(sym)                                  \
 201        __EXPORT_SYMBOL(sym, "_gpl")
 202
 203#define EXPORT_SYMBOL_GPL_FUTURE(sym)                           \
 204        __EXPORT_SYMBOL(sym, "_gpl_future")
 205
 206
 207#ifdef CONFIG_UNUSED_SYMBOLS
 208#define EXPORT_UNUSED_SYMBOL(sym) __EXPORT_SYMBOL(sym, "_unused")
 209#define EXPORT_UNUSED_SYMBOL_GPL(sym) __EXPORT_SYMBOL(sym, "_unused_gpl")
 210#else
 211#define EXPORT_UNUSED_SYMBOL(sym)
 212#define EXPORT_UNUSED_SYMBOL_GPL(sym)
 213#endif
 214
 215#endif
 216
 217struct module_ref
 218{
 219        local_t count;
 220} ____cacheline_aligned;
 221
 222enum module_state
 223{
 224        MODULE_STATE_LIVE,
 225        MODULE_STATE_COMING,
 226        MODULE_STATE_GOING,
 227};
 228
 229/* Similar stuff for section attributes. */
 230#define MODULE_SECT_NAME_LEN 32
 231struct module_sect_attr
 232{
 233        struct module_attribute mattr;
 234        char name[MODULE_SECT_NAME_LEN];
 235        unsigned long address;
 236};
 237
 238struct module_sect_attrs
 239{
 240        struct attribute_group grp;
 241        struct module_sect_attr attrs[0];
 242};
 243
 244struct module_param_attrs;
 245
 246struct module
 247{
 248        enum module_state state;
 249
 250        /* Member of list of modules */
 251        struct list_head list;
 252
 253        /* Unique handle for this module */
 254        char name[MODULE_NAME_LEN];
 255
 256        /* Sysfs stuff. */
 257        struct module_kobject mkobj;
 258        struct module_param_attrs *param_attrs;
 259        struct module_attribute *modinfo_attrs;
 260        const char *version;
 261        const char *srcversion;
 262
 263        /* Exported symbols */
 264        const struct kernel_symbol *syms;
 265        unsigned int num_syms;
 266        const unsigned long *crcs;
 267
 268        /* GPL-only exported symbols. */
 269        const struct kernel_symbol *gpl_syms;
 270        unsigned int num_gpl_syms;
 271        const unsigned long *gpl_crcs;
 272
 273        /* unused exported symbols. */
 274        const struct kernel_symbol *unused_syms;
 275        unsigned int num_unused_syms;
 276        const unsigned long *unused_crcs;
 277        /* GPL-only, unused exported symbols. */
 278        const struct kernel_symbol *unused_gpl_syms;
 279        unsigned int num_unused_gpl_syms;
 280        const unsigned long *unused_gpl_crcs;
 281
 282        /* symbols that will be GPL-only in the near future. */
 283        const struct kernel_symbol *gpl_future_syms;
 284        unsigned int num_gpl_future_syms;
 285        const unsigned long *gpl_future_crcs;
 286
 287        /* Exception table */
 288        unsigned int num_exentries;
 289        const struct exception_table_entry *extable;
 290
 291        /* Startup function. */
 292        int (*init)(void);
 293
 294        /* If this is non-NULL, vfree after init() returns */
 295        void *module_init;
 296
 297        /* Here is the actual code + data, vfree'd on unload. */
 298        void *module_core;
 299
 300        /* Here are the sizes of the init and core sections */
 301        unsigned long init_size, core_size;
 302
 303        /* The size of the executable code in each section.  */
 304        unsigned long init_text_size, core_text_size;
 305
 306        /* The handle returned from unwind_add_table. */
 307        void *unwind_info;
 308
 309        /* Arch-specific module values */
 310        struct mod_arch_specific arch;
 311
 312        /* Am I unsafe to unload? */
 313        int unsafe;
 314
 315        /* Am I GPL-compatible */
 316        int license_gplok;
 317
 318#ifdef CONFIG_MODULE_UNLOAD
 319        /* Reference counts */
 320        struct module_ref ref[NR_CPUS];
 321
 322        /* What modules depend on me? */
 323        struct list_head modules_which_use_me;
 324
 325        /* Who is waiting for us to be unloaded */
 326        struct task_struct *waiter;
 327
 328        /* Destruction function. */
 329        void (*exit)(void);
 330#endif
 331
 332#ifdef CONFIG_KALLSYMS
 333        /* We keep the symbol and string tables for kallsyms. */
 334        Elf_Sym *symtab;
 335        unsigned long num_symtab;
 336        char *strtab;
 337
 338        /* Section attributes */
 339        struct module_sect_attrs *sect_attrs;
 340#endif
 341
 342        /* Per-cpu data. */
 343        void *percpu;
 344
 345        /* The command line arguments (may be mangled).  People like
 346           keeping pointers to this stuff */
 347        char *args;
 348};
 349
 350/* FIXME: It'd be nice to isolate modules during init, too, so they
 351   aren't used before they (may) fail.  But presently too much code
 352   (IDE & SCSI) require entry into the module during init.*/
 353static inline int module_is_live(struct module *mod)
 354{
 355        return mod->state != MODULE_STATE_GOING;
 356}
 357
 358/* Is this address in a module? (second is with no locks, for oops) */
 359struct module *module_text_address(unsigned long addr);
 360struct module *__module_text_address(unsigned long addr);
 361int is_module_address(unsigned long addr);
 362
 363/* Returns module and fills in value, defined and namebuf, or NULL if
 364   symnum out of range. */
 365struct module *module_get_kallsym(unsigned int symnum, unsigned long *value,
 366                                char *type, char *name, size_t namelen);
 367
 368/* Look for this name: can be of form module:name. */
 369unsigned long module_kallsyms_lookup_name(const char *name);
 370
 371int is_exported(const char *name, const struct module *mod);
 372
 373extern void __module_put_and_exit(struct module *mod, long code)
 374        __attribute__((noreturn));
 375#define module_put_and_exit(code) __module_put_and_exit(THIS_MODULE, code);
 376
 377#ifdef CONFIG_MODULE_UNLOAD
 378unsigned int module_refcount(struct module *mod);
 379void __symbol_put(const char *symbol);
 380#define symbol_put(x) __symbol_put(MODULE_SYMBOL_PREFIX #x)
 381void symbol_put_addr(void *addr);
 382
 383/* Sometimes we know we already have a refcount, and it's easier not
 384   to handle the error case (which only happens with rmmod --wait). */
 385static inline void __module_get(struct module *module)
 386{
 387        if (module) {
 388                BUG_ON(module_refcount(module) == 0);
 389                local_inc(&module->ref[get_cpu()].count);
 390                put_cpu();
 391        }
 392}
 393
 394static inline int try_module_get(struct module *module)
 395{
 396        int ret = 1;
 397
 398        if (module) {
 399                unsigned int cpu = get_cpu();
 400                if (likely(module_is_live(module)))
 401                        local_inc(&module->ref[cpu].count);
 402                else
 403                        ret = 0;
 404                put_cpu();
 405        }
 406        return ret;
 407}
 408
 409static inline void module_put(struct module *module)
 410{
 411        if (module) {
 412                unsigned int cpu = get_cpu();
 413                local_dec(&module->ref[cpu].count);
 414                /* Maybe they're waiting for us to drop reference? */
 415                if (unlikely(!module_is_live(module)))
 416                        wake_up_process(module->waiter);
 417                put_cpu();
 418        }
 419}
 420
 421#else /*!CONFIG_MODULE_UNLOAD*/
 422static inline int try_module_get(struct module *module)
 423{
 424        return !module || module_is_live(module);
 425}
 426static inline void module_put(struct module *module)
 427{
 428}
 429static inline void __module_get(struct module *module)
 430{
 431}
 432#define symbol_put(x) do { } while(0)
 433#define symbol_put_addr(p) do { } while(0)
 434
 435#endif /* CONFIG_MODULE_UNLOAD */
 436
 437/* This is a #define so the string doesn't get put in every .o file */
 438#define module_name(mod)                        \
 439({                                              \
 440        struct module *__mod = (mod);           \
 441        __mod ? __mod->name : "kernel";         \
 442})
 443
 444#define __unsafe(mod)                                                        \
 445do {                                                                         \
 446        if (mod && !(mod)->unsafe) {                                         \
 447                printk(KERN_WARNING                                          \
 448                       "Module %s cannot be unloaded due to unsafe usage in" \
 449                       " %s:%u\n", (mod)->name, __FILE__, __LINE__);         \
 450                (mod)->unsafe = 1;                                           \
 451        }                                                                    \
 452} while(0)
 453
 454/* For kallsyms to ask for address resolution.  NULL means not found. */
 455const char *module_address_lookup(unsigned long addr,
 456                                  unsigned long *symbolsize,
 457                                  unsigned long *offset,
 458                                  char **modname);
 459
 460/* For extable.c to search modules' exception tables. */
 461const struct exception_table_entry *search_module_extables(unsigned long addr);
 462
 463int register_module_notifier(struct notifier_block * nb);
 464int unregister_module_notifier(struct notifier_block * nb);
 465
 466extern void print_modules(void);
 467
 468struct device_driver;
 469void module_add_driver(struct module *, struct device_driver *);
 470void module_remove_driver(struct device_driver *);
 471
 472#else /* !CONFIG_MODULES... */
 473#define EXPORT_SYMBOL(sym)
 474#define EXPORT_SYMBOL_GPL(sym)
 475#define EXPORT_SYMBOL_GPL_FUTURE(sym)
 476#define EXPORT_UNUSED_SYMBOL(sym)
 477#define EXPORT_UNUSED_SYMBOL_GPL(sym)
 478
 479/* Given an address, look for it in the exception tables. */
 480static inline const struct exception_table_entry *
 481search_module_extables(unsigned long addr)
 482{
 483        return NULL;
 484}
 485
 486/* Is this address in a module? */
 487static inline struct module *module_text_address(unsigned long addr)
 488{
 489        return NULL;
 490}
 491
 492/* Is this address in a module? (don't take a lock, we're oopsing) */
 493static inline struct module *__module_text_address(unsigned long addr)
 494{
 495        return NULL;
 496}
 497
 498static inline int is_module_address(unsigned long addr)
 499{
 500        return 0;
 501}
 502
 503/* Get/put a kernel symbol (calls should be symmetric) */
 504#define symbol_get(x) ({ extern typeof(x) x __attribute__((weak)); &(x); })
 505#define symbol_put(x) do { } while(0)
 506#define symbol_put_addr(x) do { } while(0)
 507
 508static inline void __module_get(struct module *module)
 509{
 510}
 511
 512static inline int try_module_get(struct module *module)
 513{
 514        return 1;
 515}
 516
 517static inline void module_put(struct module *module)
 518{
 519}
 520
 521#define module_name(mod) "kernel"
 522
 523#define __unsafe(mod)
 524
 525/* For kallsyms to ask for address resolution.  NULL means not found. */
 526static inline const char *module_address_lookup(unsigned long addr,
 527                                                unsigned long *symbolsize,
 528                                                unsigned long *offset,
 529                                                char **modname)
 530{
 531        return NULL;
 532}
 533
 534static inline struct module *module_get_kallsym(unsigned int symnum,
 535                                                unsigned long *value,
 536                                                char *type, char *name,
 537                                                size_t namelen)
 538{
 539        return NULL;
 540}
 541
 542static inline unsigned long module_kallsyms_lookup_name(const char *name)
 543{
 544        return 0;
 545}
 546
 547static inline int is_exported(const char *name, const struct module *mod)
 548{
 549        return 0;
 550}
 551
 552static inline int register_module_notifier(struct notifier_block * nb)
 553{
 554        /* no events will happen anyway, so this can always succeed */
 555        return 0;
 556}
 557
 558static inline int unregister_module_notifier(struct notifier_block * nb)
 559{
 560        return 0;
 561}
 562
 563#define module_put_and_exit(code) do_exit(code)
 564
 565static inline void print_modules(void)
 566{
 567}
 568
 569struct device_driver;
 570struct module;
 571
 572static inline void module_add_driver(struct module *module, struct device_driver *driver)
 573{
 574}
 575
 576static inline void module_remove_driver(struct device_driver *driver)
 577{
 578}
 579
 580#endif /* CONFIG_MODULES */
 581
 582#define symbol_request(x) try_then_request_module(symbol_get(x), "symbol:" #x)
 583
 584/* BELOW HERE ALL THESE ARE OBSOLETE AND WILL VANISH */
 585
 586#define __MODULE_STRING(x) __stringify(x)
 587
 588#endif /* _LINUX_MODULE_H */
 589
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