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
 222enum module_state
 223{
 224        MODULE_STATE_LIVE,
 225        MODULE_STATE_COMING,
 226        MODULE_STATE_GOING,
 227};
 228
 229struct 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_attribute *modinfo_attrs;
 242        const char *version;
 243        const char *srcversion;
 244        struct kobject *holders_dir;
 245
 246        /* Exported symbols */
 247        const struct kernel_symbol *syms;
 248        const unsigned long *crcs;
 249        unsigned int num_syms;
 250
 251        /* Kernel parameters. */
 252        struct kernel_param *kp;
 253        unsigned int num_kp;
 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        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        /* Arch-specific module values */
 297        struct mod_arch_specific arch;
 298
 299        unsigned int taints;    /* same bits as kernel:tainted */
 300
 301#ifdef CONFIG_GENERIC_BUG
 302        /* Support for BUG */
 303        unsigned num_bugs;
 304        struct list_head bug_list;
 305        struct bug_entry *bug_table;
 306#endif
 307
 308#ifdef CONFIG_KALLSYMS
 309        /* We keep the symbol and string tables for kallsyms. */
 310        Elf_Sym *symtab;
 311        unsigned int num_symtab;
 312        char *strtab;
 313
 314        /* Section attributes */
 315        struct module_sect_attrs *sect_attrs;
 316
 317        /* Notes attributes */
 318        struct module_notes_attrs *notes_attrs;
 319#endif
 320
 321        /* Per-cpu data. */
 322        void *percpu;
 323
 324        /* The command line arguments (may be mangled).  People like
 325           keeping pointers to this stuff */
 326        char *args;
 327#ifdef CONFIG_MARKERS
 328        struct marker *markers;
 329        unsigned int num_markers;
 330#endif
 331#ifdef CONFIG_TRACEPOINTS
 332        struct tracepoint *tracepoints;
 333        unsigned int num_tracepoints;
 334#endif
 335
 336#ifdef CONFIG_TRACING
 337        const char **trace_bprintk_fmt_start;
 338        unsigned int num_trace_bprintk_fmt;
 339#endif
 340
 341#ifdef CONFIG_MODULE_UNLOAD
 342        /* What modules depend on me? */
 343        struct list_head modules_which_use_me;
 344
 345        /* Who is waiting for us to be unloaded */
 346        struct task_struct *waiter;
 347
 348        /* Destruction function. */
 349        void (*exit)(void);
 350
 351#ifdef CONFIG_SMP
 352        char *refptr;
 353#else
 354        local_t ref;
 355#endif
 356#endif
 357};
 358#ifndef MODULE_ARCH_INIT
 359#define MODULE_ARCH_INIT {}
 360#endif
 361
 362extern struct mutex module_mutex;
 363
 364/* FIXME: It'd be nice to isolate modules during init, too, so they
 365   aren't used before they (may) fail.  But presently too much code
 366   (IDE & SCSI) require entry into the module during init.*/
 367static inline int module_is_live(struct module *mod)
 368{
 369        return mod->state != MODULE_STATE_GOING;
 370}
 371
 372struct module *__module_text_address(unsigned long addr);
 373struct module *__module_address(unsigned long addr);
 374bool is_module_address(unsigned long addr);
 375bool is_module_text_address(unsigned long addr);
 376
 377static inline int within_module_core(unsigned long addr, struct module *mod)
 378{
 379        return (unsigned long)mod->module_core <= addr &&
 380               addr < (unsigned long)mod->module_core + mod->core_size;
 381}
 382
 383static inline int within_module_init(unsigned long addr, struct module *mod)
 384{
 385        return (unsigned long)mod->module_init <= addr &&
 386               addr < (unsigned long)mod->module_init + mod->init_size;
 387}
 388
 389/* Search for module by name: must hold module_mutex. */
 390struct module *find_module(const char *name);
 391
 392struct symsearch {
 393        const struct kernel_symbol *start, *stop;
 394        const unsigned long *crcs;
 395        enum {
 396                NOT_GPL_ONLY,
 397                GPL_ONLY,
 398                WILL_BE_GPL_ONLY,
 399        } licence;
 400        bool unused;
 401};
 402
 403/* Search for an exported symbol by name. */
 404const struct kernel_symbol *find_symbol(const char *name,
 405                                        struct module **owner,
 406                                        const unsigned long **crc,
 407                                        bool gplok,
 408                                        bool warn);
 409
 410/* Walk the exported symbol table */
 411bool each_symbol(bool (*fn)(const struct symsearch *arr, struct module *owner,
 412                            unsigned int symnum, void *data), void *data);
 413
 414/* Returns 0 and fills in value, defined and namebuf, or -ERANGE if
 415   symnum out of range. */
 416int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
 417                        char *name, char *module_name, int *exported);
 418
 419/* Look for this name: can be of form module:name. */
 420unsigned long module_kallsyms_lookup_name(const char *name);
 421
 422int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
 423                                             struct module *, unsigned long),
 424                                   void *data);
 425
 426extern void __module_put_and_exit(struct module *mod, long code)
 427        __attribute__((noreturn));
 428#define module_put_and_exit(code) __module_put_and_exit(THIS_MODULE, code);
 429
 430#ifdef CONFIG_MODULE_UNLOAD
 431unsigned int module_refcount(struct module *mod);
 432void __symbol_put(const char *symbol);
 433#define symbol_put(x) __symbol_put(MODULE_SYMBOL_PREFIX #x)
 434void symbol_put_addr(void *addr);
 435
 436static inline local_t *__module_ref_addr(struct module *mod, int cpu)
 437{
 438#ifdef CONFIG_SMP
 439        return (local_t *) (mod->refptr + per_cpu_offset(cpu));
 440#else
 441        return &mod->ref;
 442#endif
 443}
 444
 445/* Sometimes we know we already have a refcount, and it's easier not
 446   to handle the error case (which only happens with rmmod --wait). */
 447static inline void __module_get(struct module *module)
 448{
 449        if (module) {
 450                local_inc(__module_ref_addr(module, get_cpu()));
 451                put_cpu();
 452        }
 453}
 454
 455static inline int try_module_get(struct module *module)
 456{
 457        int ret = 1;
 458
 459        if (module) {
 460                unsigned int cpu = get_cpu();
 461                if (likely(module_is_live(module)))
 462                        local_inc(__module_ref_addr(module, cpu));
 463                else
 464                        ret = 0;
 465                put_cpu();
 466        }
 467        return ret;
 468}
 469
 470extern void module_put(struct module *module);
 471
 472#else /*!CONFIG_MODULE_UNLOAD*/
 473static inline int try_module_get(struct module *module)
 474{
 475        return !module || module_is_live(module);
 476}
 477static inline void module_put(struct module *module)
 478{
 479}
 480static inline void __module_get(struct module *module)
 481{
 482}
 483#define symbol_put(x) do { } while(0)
 484#define symbol_put_addr(p) do { } while(0)
 485
 486#endif /* CONFIG_MODULE_UNLOAD */
 487int use_module(struct module *a, struct module *b);
 488
 489/* This is a #define so the string doesn't get put in every .o file */
 490#define module_name(mod)                        \
 491({                                              \
 492        struct module *__mod = (mod);           \
 493        __mod ? __mod->name : "kernel";         \
 494})
 495
 496/* For kallsyms to ask for address resolution.  namebuf should be at
 497 * least KSYM_NAME_LEN long: a pointer to namebuf is returned if
 498 * found, otherwise NULL. */
 499const char *module_address_lookup(unsigned long addr,
 500                            unsigned long *symbolsize,
 501                            unsigned long *offset,
 502                            char **modname,
 503                            char *namebuf);
 504int lookup_module_symbol_name(unsigned long addr, char *symname);
 505int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name);
 506
 507/* For extable.c to search modules' exception tables. */
 508const struct exception_table_entry *search_module_extables(unsigned long addr);
 509
 510int register_module_notifier(struct notifier_block * nb);
 511int unregister_module_notifier(struct notifier_block * nb);
 512
 513extern void print_modules(void);
 514
 515extern void module_update_markers(void);
 516
 517extern void module_update_tracepoints(void);
 518extern int module_get_iter_tracepoints(struct tracepoint_iter *iter);
 519
 520#else /* !CONFIG_MODULES... */
 521#define EXPORT_SYMBOL(sym)
 522#define EXPORT_SYMBOL_GPL(sym)
 523#define EXPORT_SYMBOL_GPL_FUTURE(sym)
 524#define EXPORT_UNUSED_SYMBOL(sym)
 525#define EXPORT_UNUSED_SYMBOL_GPL(sym)
 526
 527/* Given an address, look for it in the exception tables. */
 528static inline const struct exception_table_entry *
 529search_module_extables(unsigned long addr)
 530{
 531        return NULL;
 532}
 533
 534static inline struct module *__module_address(unsigned long addr)
 535{
 536        return NULL;
 537}
 538
 539static inline struct module *__module_text_address(unsigned long addr)
 540{
 541        return NULL;
 542}
 543
 544static inline bool is_module_address(unsigned long addr)
 545{
 546        return false;
 547}
 548
 549static inline bool is_module_text_address(unsigned long addr)
 550{
 551        return false;
 552}
 553
 554/* Get/put a kernel symbol (calls should be symmetric) */
 555#define symbol_get(x) ({ extern typeof(x) x __attribute__((weak)); &(x); })
 556#define symbol_put(x) do { } while(0)
 557#define symbol_put_addr(x) do { } while(0)
 558
 559static inline void __module_get(struct module *module)
 560{
 561}
 562
 563static inline int try_module_get(struct module *module)
 564{
 565        return 1;
 566}
 567
 568static inline void module_put(struct module *module)
 569{
 570}
 571
 572#define module_name(mod) "kernel"
 573
 574/* For kallsyms to ask for address resolution.  NULL means not found. */
 575static inline const char *module_address_lookup(unsigned long addr,
 576                                          unsigned long *symbolsize,
 577                                          unsigned long *offset,
 578                                          char **modname,
 579                                          char *namebuf)
 580{
 581        return NULL;
 582}
 583
 584static inline int lookup_module_symbol_name(unsigned long addr, char *symname)
 585{
 586        return -ERANGE;
 587}
 588
 589static inline int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name)
 590{
 591        return -ERANGE;
 592}
 593
 594static inline int module_get_kallsym(unsigned int symnum, unsigned long *value,
 595                                        char *type, char *name,
 596                                        char *module_name, int *exported)
 597{
 598        return -ERANGE;
 599}
 600
 601static inline unsigned long module_kallsyms_lookup_name(const char *name)
 602{
 603        return 0;
 604}
 605
 606static inline int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
 607                                                           struct module *,
 608                                                           unsigned long),
 609                                                 void *data)
 610{
 611        return 0;
 612}
 613
 614static inline int register_module_notifier(struct notifier_block * nb)
 615{
 616        /* no events will happen anyway, so this can always succeed */
 617        return 0;
 618}
 619
 620static inline int unregister_module_notifier(struct notifier_block * nb)
 621{
 622        return 0;
 623}
 624
 625#define module_put_and_exit(code) do_exit(code)
 626
 627static inline void print_modules(void)
 628{
 629}
 630
 631static inline void module_update_markers(void)
 632{
 633}
 634
 635static inline void module_update_tracepoints(void)
 636{
 637}
 638
 639static inline int module_get_iter_tracepoints(struct tracepoint_iter *iter)
 640{
 641        return 0;
 642}
 643
 644#endif /* CONFIG_MODULES */
 645
 646struct device_driver;
 647#ifdef CONFIG_SYSFS
 648struct module;
 649
 650extern struct kset *module_kset;
 651extern struct kobj_type module_ktype;
 652extern int module_sysfs_initialized;
 653
 654int mod_sysfs_init(struct module *mod);
 655int mod_sysfs_setup(struct module *mod,
 656                           struct kernel_param *kparam,
 657                           unsigned int num_params);
 658int module_add_modinfo_attrs(struct module *mod);
 659void module_remove_modinfo_attrs(struct module *mod);
 660
 661#else /* !CONFIG_SYSFS */
 662
 663static inline int mod_sysfs_init(struct module *mod)
 664{
 665        return 0;
 666}
 667
 668static inline int mod_sysfs_setup(struct module *mod,
 669                           struct kernel_param *kparam,
 670                           unsigned int num_params)
 671{
 672        return 0;
 673}
 674
 675static inline int module_add_modinfo_attrs(struct module *mod)
 676{
 677        return 0;
 678}
 679
 680static inline void module_remove_modinfo_attrs(struct module *mod)
 681{ }
 682
 683#endif /* CONFIG_SYSFS */
 684
 685#define symbol_request(x) try_then_request_module(symbol_get(x), "symbol:" #x)
 686
 687/* BELOW HERE ALL THESE ARE OBSOLETE AND WILL VANISH */
 688
 689#define __MODULE_STRING(x) __stringify(x)
 690
 691#endif /* _LINUX_MODULE_H */
 692
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