linux/include/linux/module.h History
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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/list.h>
  10#include <linux/stat.h>
  11#include <linux/compiler.h>
  12#include <linux/cache.h>
  13#include <linux/kmod.h>
  14#include <linux/elf.h>
  15#include <linux/stringify.h>
  16#include <linux/kobject.h>
  17#include <linux/moduleparam.h>
  18#include <linux/marker.h>
  19#include <asm/local.h>
  20
  21#include <asm/module.h>
  22
  23/* Not Yet Implemented */
  24#define MODULE_SUPPORTED_DEVICE(name)
  25
  26/* some toolchains uses a `_' prefix for all user symbols */
  27#ifndef MODULE_SYMBOL_PREFIX
  28#define MODULE_SYMBOL_PREFIX ""
  29#endif
  30
  31#define MODULE_NAME_LEN (64 - sizeof(unsigned long))
  32
  33struct kernel_symbol
  34{
  35        unsigned long value;
  36        const char *name;
  37};
  38
  39struct modversion_info
  40{
  41        unsigned long crc;
  42        char name[MODULE_NAME_LEN];
  43};
  44
  45struct module;
  46
  47struct module_attribute {
  48        struct attribute attr;
  49        ssize_t (*show)(struct module_attribute *, struct module *, char *);
  50        ssize_t (*store)(struct module_attribute *, struct module *,
  51                         const char *, size_t count);
  52        void (*setup)(struct module *, const char *);
  53        int (*test)(struct module *);
  54        void (*free)(struct module *);
  55};
  56
  57struct module_kobject
  58{
  59        struct kobject kobj;
  60        struct module *mod;
  61        struct kobject *drivers_dir;
  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
  79#ifdef MODULE
  80#define MODULE_GENERIC_TABLE(gtype,name)                        \
  81extern const struct gtype##_id __mod_##gtype##_table            \
  82  __attribute__ ((unused, alias(__stringify(name))))
  83
  84extern 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 MIT/GPL"                  [GNU Public License v2
 107 *                                       or MIT license choice]
 108 *      "Dual MPL/GPL"                  [GNU Public License v2
 109 *                                       or Mozilla license choice]
 110 *
 111 * The following other idents are available
 112 *
 113 *      "Proprietary"                   [Non free products]
 114 *
 115 * There are dual licensed components, but when running with Linux it is the
 116 * GPL that is relevant so this is a non issue. Similarly LGPL linked with GPL
 117 * is a GPL combined work.
 118 *
 119 * This exists for several reasons
 120 * 1.   So modinfo can show license info for users wanting to vet their setup 
 121 *      is free
 122 * 2.   So the community can ignore bug reports including proprietary modules
 123 * 3.   So vendors can do likewise based on their own policies
 124 */
 125#define MODULE_LICENSE(_license) MODULE_INFO(license, _license)
 126
 127/* Author, ideally of form NAME[, NAME]*[ and NAME] */
 128#define MODULE_AUTHOR(_author) MODULE_INFO(author, _author)
 129  
 130/* What your module does. */
 131#define MODULE_DESCRIPTION(_description) MODULE_INFO(description, _description)
 132
 133/* One for each parameter, describing how to use it.  Some files do
 134   multiple of these per line, so can't just use MODULE_INFO. */
 135#define MODULE_PARM_DESC(_parm, desc) \
 136        __MODULE_INFO(parm, _parm, #_parm ":" desc)
 137
 138#define MODULE_DEVICE_TABLE(type,name)          \
 139  MODULE_GENERIC_TABLE(type##_device,name)
 140
 141/* Version of form [<epoch>:]<version>[-<extra-version>].
 142   Or for CVS/RCS ID version, everything but the number is stripped.
 143  <epoch>: A (small) unsigned integer which allows you to start versions
 144           anew. If not mentioned, it's zero.  eg. "2:1.0" is after
 145           "1:2.0".
 146  <version>: The <version> may contain only alphanumerics and the
 147           character `.'.  Ordered by numeric sort for numeric parts,
 148           ascii sort for ascii parts (as per RPM or DEB algorithm).
 149  <extraversion>: Like <version>, but inserted for local
 150           customizations, eg "rh3" or "rusty1".
 151
 152  Using this automatically adds a checksum of the .c files and the
 153  local headers in "srcversion".
 154*/
 155#define MODULE_VERSION(_version) MODULE_INFO(version, _version)
 156
 157/* Optional firmware file (or files) needed by the module
 158 * format is simply firmware file name.  Multiple firmware
 159 * files require multiple MODULE_FIRMWARE() specifiers */
 160#define MODULE_FIRMWARE(_firmware) MODULE_INFO(firmware, _firmware)
 161
 162/* Given an address, look for it in the exception tables */
 163const struct exception_table_entry *search_exception_tables(unsigned long add);
 164
 165struct notifier_block;
 166
 167#ifdef CONFIG_MODULES
 168
 169/* Get/put a kernel symbol (calls must be symmetric) */
 170void *__symbol_get(const char *symbol);
 171void *__symbol_get_gpl(const char *symbol);
 172#define symbol_get(x) ((typeof(&x))(__symbol_get(MODULE_SYMBOL_PREFIX #x)))
 173
 174#ifndef __GENKSYMS__
 175#ifdef CONFIG_MODVERSIONS
 176/* Mark the CRC weak since genksyms apparently decides not to
 177 * generate a checksums for some symbols */
 178#define __CRC_SYMBOL(sym, sec)                                  \
 179        extern void *__crc_##sym __attribute__((weak));         \
 180        static const unsigned long __kcrctab_##sym              \
 181        __used                                                  \
 182        __attribute__((section("__kcrctab" sec), unused))       \
 183        = (unsigned long) &__crc_##sym;
 184#else
 185#define __CRC_SYMBOL(sym, sec)
 186#endif
 187
 188/* For every exported symbol, place a struct in the __ksymtab section */
 189#define __EXPORT_SYMBOL(sym, sec)                               \
 190        extern typeof(sym) sym;                                 \
 191        __CRC_SYMBOL(sym, sec)                                  \
 192        static const char __kstrtab_##sym[]                     \
 193        __attribute__((section("__ksymtab_strings"), aligned(1))) \
 194        = MODULE_SYMBOL_PREFIX #sym;                            \
 195        static const struct kernel_symbol __ksymtab_##sym       \
 196        __used                                                  \
 197        __attribute__((section("__ksymtab" sec), unused))       \
 198        = { (unsigned long)&sym, __kstrtab_##sym }
 199
 200#define EXPORT_SYMBOL(sym)                                      \
 201        __EXPORT_SYMBOL(sym, "")
 202
 203#define EXPORT_SYMBOL_GPL(sym)                                  \
 204        __EXPORT_SYMBOL(sym, "_gpl")
 205
 206#define EXPORT_SYMBOL_GPL_FUTURE(sym)                           \
 207        __EXPORT_SYMBOL(sym, "_gpl_future")
 208
 209
 210#ifdef CONFIG_UNUSED_SYMBOLS
 211#define EXPORT_UNUSED_SYMBOL(sym) __EXPORT_SYMBOL(sym, "_unused")
 212#define EXPORT_UNUSED_SYMBOL_GPL(sym) __EXPORT_SYMBOL(sym, "_unused_gpl")
 213#else
 214#define EXPORT_UNUSED_SYMBOL(sym)
 215#define EXPORT_UNUSED_SYMBOL_GPL(sym)
 216#endif
 217
 218#endif
 219
 220struct module_ref
 221{
 222        local_t count;
 223} ____cacheline_aligned;
 224
 225enum module_state
 226{
 227        MODULE_STATE_LIVE,
 228        MODULE_STATE_COMING,
 229        MODULE_STATE_GOING,
 230};
 231
 232struct module
 233{
 234        enum module_state state;
 235
 236        /* Member of list of modules */
 237        struct list_head list;
 238
 239        /* Unique handle for this module */
 240        char name[MODULE_NAME_LEN];
 241
 242        /* Sysfs stuff. */
 243        struct module_kobject mkobj;
 244        struct module_param_attrs *param_attrs;
 245        struct module_attribute *modinfo_attrs;
 246        const char *version;
 247        const char *srcversion;
 248        struct kobject *holders_dir;
 249
 250        /* Exported symbols */
 251        const struct kernel_symbol *syms;
 252        const unsigned long *crcs;
 253        unsigned int num_syms;
 254
 255        /* GPL-only exported symbols. */
 256        unsigned int num_gpl_syms;
 257        const struct kernel_symbol *gpl_syms;
 258        const unsigned long *gpl_crcs;
 259
 260#ifdef CONFIG_UNUSED_SYMBOLS
 261        /* unused exported symbols. */
 262        const struct kernel_symbol *unused_syms;
 263        const unsigned long *unused_crcs;
 264        unsigned int num_unused_syms;
 265
 266        /* GPL-only, unused exported symbols. */
 267        unsigned int num_unused_gpl_syms;
 268        const struct kernel_symbol *unused_gpl_syms;
 269        const unsigned long *unused_gpl_crcs;
 270#endif
 271
 272        /* symbols that will be GPL-only in the near future. */
 273        const struct kernel_symbol *gpl_future_syms;
 274        const unsigned long *gpl_future_crcs;
 275        unsigned int num_gpl_future_syms;
 276
 277        /* Exception table */
 278        unsigned int num_exentries;
 279        const struct exception_table_entry *extable;
 280
 281        /* Startup function. */
 282        int (*init)(void);
 283
 284        /* If this is non-NULL, vfree after init() returns */
 285        void *module_init;
 286
 287        /* Here is the actual code + data, vfree'd on unload. */
 288        void *module_core;
 289
 290        /* Here are the sizes of the init and core sections */
 291        unsigned int init_size, core_size;
 292
 293        /* The size of the executable code in each section.  */
 294        unsigned int init_text_size, core_text_size;
 295
 296        /* The handle returned from unwind_add_table. */
 297        void *unwind_info;
 298
 299        /* Arch-specific module values */
 300        struct mod_arch_specific arch;
 301
 302        unsigned int taints;    /* same bits as kernel:tainted */
 303
 304#ifdef CONFIG_GENERIC_BUG
 305        /* Support for BUG */
 306        unsigned num_bugs;
 307        struct list_head bug_list;
 308        struct bug_entry *bug_table;
 309#endif
 310
 311#ifdef CONFIG_KALLSYMS
 312        /* We keep the symbol and string tables for kallsyms. */
 313        Elf_Sym *symtab;
 314        unsigned int num_symtab;
 315        char *strtab;
 316
 317        /* Section attributes */
 318        struct module_sect_attrs *sect_attrs;
 319
 320        /* Notes attributes */
 321        struct module_notes_attrs *notes_attrs;
 322#endif
 323
 324        /* Per-cpu data. */
 325        void *percpu;
 326
 327        /* The command line arguments (may be mangled).  People like
 328           keeping pointers to this stuff */
 329        char *args;
 330#ifdef CONFIG_MARKERS
 331        struct marker *markers;
 332        unsigned int num_markers;
 333#endif
 334
 335#ifdef CONFIG_MODULE_UNLOAD
 336        /* What modules depend on me? */
 337        struct list_head modules_which_use_me;
 338
 339        /* Who is waiting for us to be unloaded */
 340        struct task_struct *waiter;
 341
 342        /* Destruction function. */
 343        void (*exit)(void);
 344
 345        /* Reference counts */
 346        struct module_ref ref[NR_CPUS];
 347#endif
 348
 349};
 350#ifndef MODULE_ARCH_INIT
 351#define MODULE_ARCH_INIT {}
 352#endif
 353
 354/* FIXME: It'd be nice to isolate modules during init, too, so they
 355   aren't used before they (may) fail.  But presently too much code
 356   (IDE & SCSI) require entry into the module during init.*/
 357static inline int module_is_live(struct module *mod)
 358{
 359        return mod->state != MODULE_STATE_GOING;
 360}
 361
 362/* Is this address in a module? (second is with no locks, for oops) */
 363struct module *module_text_address(unsigned long addr);
 364struct module *__module_text_address(unsigned long addr);
 365int is_module_address(unsigned long addr);
 366
 367/* Returns 0 and fills in value, defined and namebuf, or -ERANGE if
 368   symnum out of range. */
 369int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
 370                        char *name, char *module_name, int *exported);
 371
 372/* Look for this name: can be of form module:name. */
 373unsigned long module_kallsyms_lookup_name(const char *name);
 374
 375extern void __module_put_and_exit(struct module *mod, long code)
 376        __attribute__((noreturn));
 377#define module_put_and_exit(code) __module_put_and_exit(THIS_MODULE, code);
 378
 379#ifdef CONFIG_MODULE_UNLOAD
 380unsigned int module_refcount(struct module *mod);
 381void __symbol_put(const char *symbol);
 382#define symbol_put(x) __symbol_put(MODULE_SYMBOL_PREFIX #x)
 383void symbol_put_addr(void *addr);
 384
 385/* Sometimes we know we already have a refcount, and it's easier not
 386   to handle the error case (which only happens with rmmod --wait). */
 387static inline void __module_get(struct module *module)
 388{
 389        if (module) {
 390                BUG_ON(module_refcount(module) == 0);
 391                local_inc(&module->ref[get_cpu()].count);
 392                put_cpu();
 393        }
 394}
 395
 396static inline int try_module_get(struct module *module)
 397{
 398        int ret = 1;
 399
 400        if (module) {
 401                unsigned int cpu = get_cpu();
 402                if (likely(module_is_live(module)))
 403                        local_inc(&module->ref[cpu].count);
 404                else
 405                        ret = 0;
 406                put_cpu();
 407        }
 408        return ret;
 409}
 410
 411extern void module_put(struct module *module);
 412
 413#else /*!CONFIG_MODULE_UNLOAD*/
 414static inline int try_module_get(struct module *module)
 415{
 416        return !module || module_is_live(module);
 417}
 418static inline void module_put(struct module *module)
 419{
 420}
 421static inline void __module_get(struct module *module)
 422{
 423}
 424#define symbol_put(x) do { } while(0)
 425#define symbol_put_addr(p) do { } while(0)
 426
 427#endif /* CONFIG_MODULE_UNLOAD */
 428
 429/* This is a #define so the string doesn't get put in every .o file */
 430#define module_name(mod)                        \
 431({                                              \
 432        struct module *__mod = (mod);           \
 433        __mod ? __mod->name : "kernel";         \
 434})
 435
 436/* For kallsyms to ask for address resolution.  namebuf should be at
 437 * least KSYM_NAME_LEN long: a pointer to namebuf is returned if
 438 * found, otherwise NULL. */
 439const char *module_address_lookup(unsigned long addr,
 440                            unsigned long *symbolsize,
 441                            unsigned long *offset,
 442                            char **modname,
 443                            char *namebuf);
 444int lookup_module_symbol_name(unsigned long addr, char *symname);
 445int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name);
 446
 447/* For extable.c to search modules' exception tables. */
 448const struct exception_table_entry *search_module_extables(unsigned long addr);
 449
 450int register_module_notifier(struct notifier_block * nb);
 451int unregister_module_notifier(struct notifier_block * nb);
 452
 453extern void print_modules(void);
 454
 455extern void module_update_markers(void);
 456
 457#else /* !CONFIG_MODULES... */
 458#define EXPORT_SYMBOL(sym)
 459#define EXPORT_SYMBOL_GPL(sym)
 460#define EXPORT_SYMBOL_GPL_FUTURE(sym)
 461#define EXPORT_UNUSED_SYMBOL(sym)
 462#define EXPORT_UNUSED_SYMBOL_GPL(sym)
 463
 464/* Given an address, look for it in the exception tables. */
 465static inline const struct exception_table_entry *
 466search_module_extables(unsigned long addr)
 467{
 468        return NULL;
 469}
 470
 471/* Is this address in a module? */
 472static inline struct module *module_text_address(unsigned long addr)
 473{
 474        return NULL;
 475}
 476
 477/* Is this address in a module? (don't take a lock, we're oopsing) */
 478static inline struct module *__module_text_address(unsigned long addr)
 479{
 480        return NULL;
 481}
 482
 483static inline int is_module_address(unsigned long addr)
 484{
 485        return 0;
 486}
 487
 488/* Get/put a kernel symbol (calls should be symmetric) */
 489#define symbol_get(x) ({ extern typeof(x) x __attribute__((weak)); &(x); })
 490#define symbol_put(x) do { } while(0)
 491#define symbol_put_addr(x) do { } while(0)
 492
 493static inline void __module_get(struct module *module)
 494{
 495}
 496
 497static inline int try_module_get(struct module *module)
 498{
 499        return 1;
 500}
 501
 502static inline void module_put(struct module *module)
 503{
 504}
 505
 506#define module_name(mod) "kernel"
 507
 508/* For kallsyms to ask for address resolution.  NULL means not found. */
 509static inline const char *module_address_lookup(unsigned long addr,
 510                                          unsigned long *symbolsize,
 511                                          unsigned long *offset,
 512                                          char **modname,
 513                                          char *namebuf)
 514{
 515        return NULL;
 516}
 517
 518static inline int lookup_module_symbol_name(unsigned long addr, char *symname)
 519{
 520        return -ERANGE;
 521}
 522
 523static inline int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name)
 524{
 525        return -ERANGE;
 526}
 527
 528static inline int module_get_kallsym(unsigned int symnum, unsigned long *value,
 529                                        char *type, char *name,
 530                                        char *module_name, int *exported)
 531{
 532        return -ERANGE;
 533}
 534
 535static inline unsigned long module_kallsyms_lookup_name(const char *name)
 536{
 537        return 0;
 538}
 539
 540static inline int register_module_notifier(struct notifier_block * nb)
 541{
 542        /* no events will happen anyway, so this can always succeed */
 543        return 0;
 544}
 545
 546static inline int unregister_module_notifier(struct notifier_block * nb)
 547{
 548        return 0;
 549}
 550
 551#define module_put_and_exit(code) do_exit(code)
 552
 553static inline void print_modules(void)
 554{
 555}
 556
 557static inline void module_update_markers(void)
 558{
 559}
 560
 561#endif /* CONFIG_MODULES */
 562
 563struct device_driver;
 564#ifdef CONFIG_SYSFS
 565struct module;
 566
 567extern struct kset *module_kset;
 568extern struct kobj_type module_ktype;
 569extern int module_sysfs_initialized;
 570
 571int mod_sysfs_init(struct module *mod);
 572int mod_sysfs_setup(struct module *mod,
 573                           struct kernel_param *kparam,
 574                           unsigned int num_params);
 575int module_add_modinfo_attrs(struct module *mod);
 576void module_remove_modinfo_attrs(struct module *mod);
 577
 578#else /* !CONFIG_SYSFS */
 579
 580static inline int mod_sysfs_init(struct module *mod)
 581{
 582        return 0;
 583}
 584
 585static inline int mod_sysfs_setup(struct module *mod,
 586                           struct kernel_param *kparam,
 587                           unsigned int num_params)
 588{
 589        return 0;
 590}
 591
 592static inline int module_add_modinfo_attrs(struct module *mod)
 593{
 594        return 0;
 595}
 596
 597static inline void module_remove_modinfo_attrs(struct module *mod)
 598{ }
 599
 600#endif /* CONFIG_SYSFS */
 601
 602#define symbol_request(x) try_then_request_module(symbol_get(x), "symbol:" #x)
 603
 604/* BELOW HERE ALL THESE ARE OBSOLETE AND WILL VANISH */
 605
 606#define __MODULE_STRING(x) __stringify(x)
 607
 608#endif /* _LINUX_MODULE_H */
 609
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