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/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 <linux/tracepoint.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/* some toolchains 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 MAX_PARAM_PREFIX_LEN
  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        struct kobject *drivers_dir;
  63        struct module_param_attrs *mp;
  64};
  65
  66/* These are either module local, or the kernel's dummy ones. */
  67extern int init_module(void);
  68extern void cleanup_module(void);
  69
  70/* Archs provide a method of finding the correct exception table. */
  71struct exception_table_entry;
  72
  73const struct exception_table_entry *
  74search_extable(const struct exception_table_entry *first,
  75               const struct exception_table_entry *last,
  76               unsigned long value);
  77void sort_extable(struct exception_table_entry *start,
  78                  struct exception_table_entry *finish);
  79void sort_main_extable(void);
  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[, NAME]*[ and NAME] */
 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/* Optional firmware file (or files) needed by the module
 160 * format is simply firmware file name.  Multiple firmware
 161 * files require multiple MODULE_FIRMWARE() specifiers */
 162#define MODULE_FIRMWARE(_firmware) MODULE_INFO(firmware, _firmware)
 163
 164/* Given an address, look for it in the exception tables */
 165const struct exception_table_entry *search_exception_tables(unsigned long add);
 166
 167struct notifier_block;
 168
 169#ifdef CONFIG_MODULES
 170
 171/* Get/put a kernel symbol (calls must be symmetric) */
 172void *__symbol_get(const char *symbol);
 173void *__symbol_get_gpl(const char *symbol);
 174#define symbol_get(x) ((typeof(&x))(__symbol_get(MODULE_SYMBOL_PREFIX #x)))
 175
 176#ifndef __GENKSYMS__
 177#ifdef CONFIG_MODVERSIONS
 178/* Mark the CRC weak since genksyms apparently decides not to
 179 * generate a checksums for some symbols */
 180#define __CRC_SYMBOL(sym, sec)                                  \
 181        extern void *__crc_##sym __attribute__((weak));         \
 182        static const unsigned long __kcrctab_##sym              \
 183        __used                                                  \
 184        __attribute__((section("__kcrctab" sec), unused))       \
 185        = (unsigned long) &__crc_##sym;
 186#else
 187#define __CRC_SYMBOL(sym, sec)
 188#endif
 189
 190/* For every exported symbol, place a struct in the __ksymtab section */
 191#define __EXPORT_SYMBOL(sym, sec)                               \
 192        extern typeof(sym) sym;                                 \
 193        __CRC_SYMBOL(sym, sec)                                  \
 194        static const char __kstrtab_##sym[]                     \
 195        __attribute__((section("__ksymtab_strings"), aligned(1))) \
 196        = MODULE_SYMBOL_PREFIX #sym;                            \
 197        static const struct kernel_symbol __ksymtab_##sym       \
 198        __used                                                  \
 199        __attribute__((section("__ksymtab" sec), unused))       \
 200        = { (unsigned long)&sym, __kstrtab_##sym }
 201
 202#define EXPORT_SYMBOL(sym)                                      \
 203        __EXPORT_SYMBOL(sym, "")
 204
 205#define EXPORT_SYMBOL_GPL(sym)                                  \
 206        __EXPORT_SYMBOL(sym, "_gpl")
 207
 208#define EXPORT_SYMBOL_GPL_FUTURE(sym)                           \
 209        __EXPORT_SYMBOL(sym, "_gpl_future")
 210
 211
 212#ifdef CONFIG_UNUSED_SYMBOLS
 213#define EXPORT_UNUSED_SYMBOL(sym) __EXPORT_SYMBOL(sym, "_unused")
 214#define EXPORT_UNUSED_SYMBOL_GPL(sym) __EXPORT_SYMBOL(sym, "_unused_gpl")
 215#else
 216#define EXPORT_UNUSED_SYMBOL(sym)
 217#define EXPORT_UNUSED_SYMBOL_GPL(sym)
 218#endif
 219
 220#endif
 221
 222struct module_ref
 223{
 224        local_t count;
 225} ____cacheline_aligned;
 226
 227enum module_state
 228{
 229        MODULE_STATE_LIVE,
 230        MODULE_STATE_COMING,
 231        MODULE_STATE_GOING,
 232};
 233
 234struct module
 235{
 236        enum module_state state;
 237
 238        /* Member of list of modules */
 239        struct list_head list;
 240
 241        /* Unique handle for this module */
 242        char name[MODULE_NAME_LEN];
 243
 244        /* Sysfs stuff. */
 245        struct module_kobject mkobj;
 246        struct module_attribute *modinfo_attrs;
 247        const char *version;
 248        const char *srcversion;
 249        struct kobject *holders_dir;
 250
 251        /* Exported symbols */
 252        const struct kernel_symbol *syms;
 253        const unsigned long *crcs;
 254        unsigned int num_syms;
 255
 256        /* GPL-only exported symbols. */
 257        unsigned int num_gpl_syms;
 258        const struct kernel_symbol *gpl_syms;
 259        const unsigned long *gpl_crcs;
 260
 261#ifdef CONFIG_UNUSED_SYMBOLS
 262        /* unused exported symbols. */
 263        const struct kernel_symbol *unused_syms;
 264        const unsigned long *unused_crcs;
 265        unsigned int num_unused_syms;
 266
 267        /* GPL-only, unused exported symbols. */
 268        unsigned int num_unused_gpl_syms;
 269        const struct kernel_symbol *unused_gpl_syms;
 270        const unsigned long *unused_gpl_crcs;
 271#endif
 272
 273        /* symbols that will be GPL-only in the near future. */
 274        const struct kernel_symbol *gpl_future_syms;
 275        const unsigned long *gpl_future_crcs;
 276        unsigned int num_gpl_future_syms;
 277
 278        /* Exception table */
 279        unsigned int num_exentries;
 280        struct exception_table_entry *extable;
 281
 282        /* Startup function. */
 283        int (*init)(void);
 284
 285        /* If this is non-NULL, vfree after init() returns */
 286        void *module_init;
 287
 288        /* Here is the actual code + data, vfree'd on unload. */
 289        void *module_core;
 290
 291        /* Here are the sizes of the init and core sections */
 292        unsigned int init_size, core_size;
 293
 294        /* The size of the executable code in each section.  */
 295        unsigned int init_text_size, core_text_size;
 296
 297        /* The handle returned from unwind_add_table. */
 298        void *unwind_info;
 299
 300        /* Arch-specific module values */
 301        struct mod_arch_specific arch;
 302
 303        unsigned int taints;    /* same bits as kernel:tainted */
 304
 305#ifdef CONFIG_GENERIC_BUG
 306        /* Support for BUG */
 307        unsigned num_bugs;
 308        struct list_head bug_list;
 309        struct bug_entry *bug_table;
 310#endif
 311
 312#ifdef CONFIG_KALLSYMS
 313        /* We keep the symbol and string tables for kallsyms. */
 314        Elf_Sym *symtab;
 315        unsigned int num_symtab;
 316        char *strtab;
 317
 318        /* Section attributes */
 319        struct module_sect_attrs *sect_attrs;
 320
 321        /* Notes attributes */
 322        struct module_notes_attrs *notes_attrs;
 323#endif
 324
 325        /* Per-cpu data. */
 326        void *percpu;
 327
 328        /* The command line arguments (may be mangled).  People like
 329           keeping pointers to this stuff */
 330        char *args;
 331#ifdef CONFIG_MARKERS
 332        struct marker *markers;
 333        unsigned int num_markers;
 334#endif
 335#ifdef CONFIG_TRACEPOINTS
 336        struct tracepoint *tracepoints;
 337        unsigned int num_tracepoints;
 338#endif
 339
 340#ifdef CONFIG_MODULE_UNLOAD
 341        /* What modules depend on me? */
 342        struct list_head modules_which_use_me;
 343
 344        /* Who is waiting for us to be unloaded */
 345        struct task_struct *waiter;
 346
 347        /* Destruction function. */
 348        void (*exit)(void);
 349
 350        /* Reference counts */
 351        struct module_ref ref[NR_CPUS];
 352#endif
 353};
 354#ifndef MODULE_ARCH_INIT
 355#define MODULE_ARCH_INIT {}
 356#endif
 357
 358/* FIXME: It'd be nice to isolate modules during init, too, so they
 359   aren't used before they (may) fail.  But presently too much code
 360   (IDE & SCSI) require entry into the module during init.*/
 361static inline int module_is_live(struct module *mod)
 362{
 363        return mod->state != MODULE_STATE_GOING;
 364}
 365
 366/* Is this address in a module? (second is with no locks, for oops) */
 367struct module *module_text_address(unsigned long addr);
 368struct module *__module_text_address(unsigned long addr);
 369int is_module_address(unsigned long addr);
 370
 371/* Returns 0 and fills in value, defined and namebuf, or -ERANGE if
 372   symnum out of range. */
 373int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
 374                        char *name, char *module_name, int *exported);
 375
 376/* Look for this name: can be of form module:name. */
 377unsigned long module_kallsyms_lookup_name(const char *name);
 378
 379extern void __module_put_and_exit(struct module *mod, long code)
 380        __attribute__((noreturn));
 381#define module_put_and_exit(code) __module_put_and_exit(THIS_MODULE, code);
 382
 383#ifdef CONFIG_MODULE_UNLOAD
 384unsigned int module_refcount(struct module *mod);
 385void __symbol_put(const char *symbol);
 386#define symbol_put(x) __symbol_put(MODULE_SYMBOL_PREFIX #x)
 387void symbol_put_addr(void *addr);
 388
 389/* Sometimes we know we already have a refcount, and it's easier not
 390   to handle the error case (which only happens with rmmod --wait). */
 391static inline void __module_get(struct module *module)
 392{
 393        if (module) {
 394                BUG_ON(module_refcount(module) == 0);
 395                local_inc(&module->ref[get_cpu()].count);
 396                put_cpu();
 397        }
 398}
 399
 400static inline int try_module_get(struct module *module)
 401{
 402        int ret = 1;
 403
 404        if (module) {
 405                unsigned int cpu = get_cpu();
 406                if (likely(module_is_live(module)))
 407                        local_inc(&module->ref[cpu].count);
 408                else
 409                        ret = 0;
 410                put_cpu();
 411        }
 412        return ret;
 413}
 414
 415extern void module_put(struct module *module);
 416
 417#else /*!CONFIG_MODULE_UNLOAD*/
 418static inline int try_module_get(struct module *module)
 419{
 420        return !module || module_is_live(module);
 421}
 422static inline void module_put(struct module *module)
 423{
 424}
 425static inline void __module_get(struct module *module)
 426{
 427}
 428#define symbol_put(x) do { } while(0)
 429#define symbol_put_addr(p) do { } while(0)
 430
 431#endif /* CONFIG_MODULE_UNLOAD */
 432
 433/* This is a #define so the string doesn't get put in every .o file */
 434#define module_name(mod)                        \
 435({                                              \
 436        struct module *__mod = (mod);           \
 437        __mod ? __mod->name : "kernel";         \
 438})
 439
 440/* For kallsyms to ask for address resolution.  namebuf should be at
 441 * least KSYM_NAME_LEN long: a pointer to namebuf is returned if
 442 * found, otherwise NULL. */
 443const char *module_address_lookup(unsigned long addr,
 444                            unsigned long *symbolsize,
 445                            unsigned long *offset,
 446                            char **modname,
 447                            char *namebuf);
 448int lookup_module_symbol_name(unsigned long addr, char *symname);
 449int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name);
 450
 451/* For extable.c to search modules' exception tables. */
 452const struct exception_table_entry *search_module_extables(unsigned long addr);
 453
 454int register_module_notifier(struct notifier_block * nb);
 455int unregister_module_notifier(struct notifier_block * nb);
 456
 457extern void print_modules(void);
 458
 459extern void module_update_markers(void);
 460
 461extern void module_update_tracepoints(void);
 462extern int module_get_iter_tracepoints(struct tracepoint_iter *iter);
 463
 464#else /* !CONFIG_MODULES... */
 465#define EXPORT_SYMBOL(sym)
 466#define EXPORT_SYMBOL_GPL(sym)
 467#define EXPORT_SYMBOL_GPL_FUTURE(sym)
 468#define EXPORT_UNUSED_SYMBOL(sym)
 469#define EXPORT_UNUSED_SYMBOL_GPL(sym)
 470
 471/* Given an address, look for it in the exception tables. */
 472static inline const struct exception_table_entry *
 473search_module_extables(unsigned long addr)
 474{
 475        return NULL;
 476}
 477
 478/* Is this address in a module? */
 479static inline struct module *module_text_address(unsigned long addr)
 480{
 481        return NULL;
 482}
 483
 484/* Is this address in a module? (don't take a lock, we're oopsing) */
 485static inline struct module *__module_text_address(unsigned long addr)
 486{
 487        return NULL;
 488}
 489
 490static inline int is_module_address(unsigned long addr)
 491{
 492        return 0;
 493}
 494
 495/* Get/put a kernel symbol (calls should be symmetric) */
 496#define symbol_get(x) ({ extern typeof(x) x __attribute__((weak)); &(x); })
 497#define symbol_put(x) do { } while(0)
 498#define symbol_put_addr(x) do { } while(0)
 499
 500static inline void __module_get(struct module *module)
 501{
 502}
 503
 504static inline int try_module_get(struct module *module)
 505{
 506        return 1;
 507}
 508
 509static inline void module_put(struct module *module)
 510{
 511}
 512
 513#define module_name(mod) "kernel"
 514
 515/* For kallsyms to ask for address resolution.  NULL means not found. */
 516static inline const char *module_address_lookup(unsigned long addr,
 517                                          unsigned long *symbolsize,
 518                                          unsigned long *offset,
 519                                          char **modname,
 520                                          char *namebuf)
 521{
 522        return NULL;
 523}
 524
 525static inline int lookup_module_symbol_name(unsigned long addr, char *symname)
 526{
 527        return -ERANGE;
 528}
 529
 530static inline int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name)
 531{
 532        return -ERANGE;
 533}
 534
 535static inline int module_get_kallsym(unsigned int symnum, unsigned long *value,
 536                                        char *type, char *name,
 537                                        char *module_name, int *exported)
 538{
 539        return -ERANGE;
 540}
 541
 542static inline unsigned long module_kallsyms_lookup_name(const char *name)
 543{
 544        return 0;
 545}
 546
 547static inline int register_module_notifier(struct notifier_block * nb)
 548{
 549        /* no events will happen anyway, so this can always succeed */
 550        return 0;
 551}
 552
 553static inline int unregister_module_notifier(struct notifier_block * nb)
 554{
 555        return 0;
 556}
 557
 558#define module_put_and_exit(code) do_exit(code)
 559
 560static inline void print_modules(void)
 561{
 562}
 563
 564static inline void module_update_markers(void)
 565{
 566}
 567
 568static inline void module_update_tracepoints(void)
 569{
 570}
 571
 572static inline int module_get_iter_tracepoints(struct tracepoint_iter *iter)
 573{
 574        return 0;
 575}
 576
 577#endif /* CONFIG_MODULES */
 578
 579struct device_driver;
 580#ifdef CONFIG_SYSFS
 581struct module;
 582
 583extern struct kset *module_kset;
 584extern struct kobj_type module_ktype;
 585extern int module_sysfs_initialized;
 586
 587int mod_sysfs_init(struct module *mod);
 588int mod_sysfs_setup(struct module *mod,
 589                           struct kernel_param *kparam,
 590                           unsigned int num_params);
 591int module_add_modinfo_attrs(struct module *mod);
 592void module_remove_modinfo_attrs(struct module *mod);
 593
 594#else /* !CONFIG_SYSFS */
 595
 596static inline int mod_sysfs_init(struct module *mod)
 597{
 598        return 0;
 599}
 600
 601static inline int mod_sysfs_setup(struct module *mod,
 602                           struct kernel_param *kparam,
 603                           unsigned int num_params)
 604{
 605        return 0;
 606}
 607
 608static inline int module_add_modinfo_attrs(struct module *mod)
 609{
 610        return 0;
 611}
 612
 613static inline void module_remove_modinfo_attrs(struct module *mod)
 614{ }
 615
 616#endif /* CONFIG_SYSFS */
 617
 618#define symbol_request(x) try_then_request_module(symbol_get(x), "symbol:" #x)
 619
 620/* BELOW HERE ALL THESE ARE OBSOLETE AND WILL VANISH */
 621
 622#define __MODULE_STRING(x) __stringify(x)
 623
 624#endif /* _LINUX_MODULE_H */
 625
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