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/jump_label.h>
  19#include <linux/export.h>
  20
  21#include <linux/percpu.h>
  22#include <asm/module.h>
  23
  24/* In stripped ARM and x86-64 modules, ~ is surprisingly rare. */
  25#define MODULE_SIG_STRING "~Module signature appended~\n"
  26
  27/* Not Yet Implemented */
  28#define MODULE_SUPPORTED_DEVICE(name)
  29
  30#define MODULE_NAME_LEN MAX_PARAM_PREFIX_LEN
  31
  32struct modversion_info {
  33        unsigned long crc;
  34        char name[MODULE_NAME_LEN];
  35};
  36
  37struct module;
  38
  39struct module_kobject {
  40        struct kobject kobj;
  41        struct module *mod;
  42        struct kobject *drivers_dir;
  43        struct module_param_attrs *mp;
  44        struct completion *kobj_completion;
  45};
  46
  47struct module_attribute {
  48        struct attribute attr;
  49        ssize_t (*show)(struct module_attribute *, struct module_kobject *,
  50                        char *);
  51        ssize_t (*store)(struct module_attribute *, struct module_kobject *,
  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_version_attribute {
  59        struct module_attribute mattr;
  60        const char *module_name;
  61        const char *version;
  62} __attribute__ ((__aligned__(sizeof(void *))));
  63
  64extern ssize_t __modver_version_show(struct module_attribute *,
  65                                     struct module_kobject *, char *);
  66
  67extern struct module_attribute module_uevent;
  68
  69/* These are either module local, or the kernel's dummy ones. */
  70extern int init_module(void);
  71extern void cleanup_module(void);
  72
  73/* Archs provide a method of finding the correct exception table. */
  74struct exception_table_entry;
  75
  76const struct exception_table_entry *
  77search_extable(const struct exception_table_entry *first,
  78               const struct exception_table_entry *last,
  79               unsigned long value);
  80void sort_extable(struct exception_table_entry *start,
  81                  struct exception_table_entry *finish);
  82void sort_main_extable(void);
  83void trim_init_extable(struct module *m);
  84
  85/* Generic info of form tag = "info" */
  86#define MODULE_INFO(tag, info) __MODULE_INFO(tag, tag, info)
  87
  88/* For userspace: you can also call me... */
  89#define MODULE_ALIAS(_alias) MODULE_INFO(alias, _alias)
  90
  91/* Soft module dependencies. See man modprobe.d for details.
  92 * Example: MODULE_SOFTDEP("pre: module-foo module-bar post: module-baz")
  93 */
  94#define MODULE_SOFTDEP(_softdep) MODULE_INFO(softdep, _softdep)
  95
  96/*
  97 * The following license idents are currently accepted as indicating free
  98 * software modules
  99 *
 100 *      "GPL"                           [GNU Public License v2 or later]
 101 *      "GPL v2"                        [GNU Public License v2]
 102 *      "GPL and additional rights"     [GNU Public License v2 rights and more]
 103 *      "Dual BSD/GPL"                  [GNU Public License v2
 104 *                                       or BSD license choice]
 105 *      "Dual MIT/GPL"                  [GNU Public License v2
 106 *                                       or MIT license choice]
 107 *      "Dual MPL/GPL"                  [GNU Public License v2
 108 *                                       or Mozilla license choice]
 109 *
 110 * The following other idents are available
 111 *
 112 *      "Proprietary"                   [Non free products]
 113 *
 114 * There are dual licensed components, but when running with Linux it is the
 115 * GPL that is relevant so this is a non issue. Similarly LGPL linked with GPL
 116 * is a GPL combined work.
 117 *
 118 * This exists for several reasons
 119 * 1.   So modinfo can show license info for users wanting to vet their setup
 120 *      is free
 121 * 2.   So the community can ignore bug reports including proprietary modules
 122 * 3.   So vendors can do likewise based on their own policies
 123 */
 124#define MODULE_LICENSE(_license) MODULE_INFO(license, _license)
 125
 126/*
 127 * Author(s), use "Name <email>" or just "Name", for multiple
 128 * authors use multiple MODULE_AUTHOR() statements/lines.
 129 */
 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#ifdef MODULE
 136/* Creates an alias so file2alias.c can find device table. */
 137#define MODULE_DEVICE_TABLE(type, name)                                 \
 138  extern const struct type##_device_id __mod_##type##__##name##_device_table \
 139  __attribute__ ((unused, alias(__stringify(name))))
 140#else  /* !MODULE */
 141#define MODULE_DEVICE_TABLE(type, name)
 142#endif
 143
 144/* Version of form [<epoch>:]<version>[-<extra-version>].
 145 * Or for CVS/RCS ID version, everything but the number is stripped.
 146 * <epoch>: A (small) unsigned integer which allows you to start versions
 147 * anew. If not mentioned, it's zero.  eg. "2:1.0" is after
 148 * "1:2.0".
 149
 150 * <version>: The <version> may contain only alphanumerics and the
 151 * character `.'.  Ordered by numeric sort for numeric parts,
 152 * ascii sort for ascii parts (as per RPM or DEB algorithm).
 153
 154 * <extraversion>: Like <version>, but inserted for local
 155 * customizations, eg "rh3" or "rusty1".
 156
 157 * Using this automatically adds a checksum of the .c files and the
 158 * local headers in "srcversion".
 159 */
 160
 161#if defined(MODULE) || !defined(CONFIG_SYSFS)
 162#define MODULE_VERSION(_version) MODULE_INFO(version, _version)
 163#else
 164#define MODULE_VERSION(_version)                                        \
 165        static struct module_version_attribute ___modver_attr = {       \
 166                .mattr  = {                                             \
 167                        .attr   = {                                     \
 168                                .name   = "version",                    \
 169                                .mode   = S_IRUGO,                      \
 170                        },                                              \
 171                        .show   = __modver_version_show,                \
 172                },                                                      \
 173                .module_name    = KBUILD_MODNAME,                       \
 174                .version        = _version,                             \
 175        };                                                              \
 176        static const struct module_version_attribute                    \
 177        __used __attribute__ ((__section__ ("__modver")))               \
 178        * __moduleparam_const __modver_attr = &___modver_attr
 179#endif
 180
 181/* Optional firmware file (or files) needed by the module
 182 * format is simply firmware file name.  Multiple firmware
 183 * files require multiple MODULE_FIRMWARE() specifiers */
 184#define MODULE_FIRMWARE(_firmware) MODULE_INFO(firmware, _firmware)
 185
 186/* Given an address, look for it in the exception tables */
 187const struct exception_table_entry *search_exception_tables(unsigned long add);
 188
 189struct notifier_block;
 190
 191#ifdef CONFIG_MODULES
 192
 193extern int modules_disabled; /* for sysctl */
 194/* Get/put a kernel symbol (calls must be symmetric) */
 195void *__symbol_get(const char *symbol);
 196void *__symbol_get_gpl(const char *symbol);
 197#define symbol_get(x) ((typeof(&x))(__symbol_get(VMLINUX_SYMBOL_STR(x))))
 198
 199/* modules using other modules: kdb wants to see this. */
 200struct module_use {
 201        struct list_head source_list;
 202        struct list_head target_list;
 203        struct module *source, *target;
 204};
 205
 206enum module_state {
 207        MODULE_STATE_LIVE,      /* Normal state. */
 208        MODULE_STATE_COMING,    /* Full formed, running module_init. */
 209        MODULE_STATE_GOING,     /* Going away. */
 210        MODULE_STATE_UNFORMED,  /* Still setting it up. */
 211};
 212
 213/**
 214 * struct module_ref - per cpu module reference counts
 215 * @incs: number of module get on this cpu
 216 * @decs: number of module put on this cpu
 217 *
 218 * We force an alignment on 8 or 16 bytes, so that alloc_percpu()
 219 * put @incs/@decs in same cache line, with no extra memory cost,
 220 * since alloc_percpu() is fine grained.
 221 */
 222struct module_ref {
 223        unsigned long incs;
 224        unsigned long decs;
 225} __attribute((aligned(2 * sizeof(unsigned long))));
 226
 227struct module {
 228        enum module_state state;
 229
 230        /* Member of list of modules */
 231        struct list_head list;
 232
 233        /* Unique handle for this module */
 234        char name[MODULE_NAME_LEN];
 235
 236        /* Sysfs stuff. */
 237        struct module_kobject mkobj;
 238        struct module_attribute *modinfo_attrs;
 239        const char *version;
 240        const char *srcversion;
 241        struct kobject *holders_dir;
 242
 243        /* Exported symbols */
 244        const struct kernel_symbol *syms;
 245        const unsigned long *crcs;
 246        unsigned int num_syms;
 247
 248        /* Kernel parameters. */
 249        struct kernel_param *kp;
 250        unsigned int num_kp;
 251
 252        /* GPL-only exported symbols. */
 253        unsigned int num_gpl_syms;
 254        const struct kernel_symbol *gpl_syms;
 255        const unsigned long *gpl_crcs;
 256
 257#ifdef CONFIG_UNUSED_SYMBOLS
 258        /* unused exported symbols. */
 259        const struct kernel_symbol *unused_syms;
 260        const unsigned long *unused_crcs;
 261        unsigned int num_unused_syms;
 262
 263        /* GPL-only, unused exported symbols. */
 264        unsigned int num_unused_gpl_syms;
 265        const struct kernel_symbol *unused_gpl_syms;
 266        const unsigned long *unused_gpl_crcs;
 267#endif
 268
 269#ifdef CONFIG_MODULE_SIG
 270        /* Signature was verified. */
 271        bool sig_ok;
 272#endif
 273
 274        /* symbols that will be GPL-only in the near future. */
 275        const struct kernel_symbol *gpl_future_syms;
 276        const unsigned long *gpl_future_crcs;
 277        unsigned int num_gpl_future_syms;
 278
 279        /* Exception table */
 280        unsigned int num_exentries;
 281        struct exception_table_entry *extable;
 282
 283        /* Startup function. */
 284        int (*init)(void);
 285
 286        /* If this is non-NULL, vfree after init() returns */
 287        void *module_init;
 288
 289        /* Here is the actual code + data, vfree'd on unload. */
 290        void *module_core;
 291
 292        /* Here are the sizes of the init and core sections */
 293        unsigned int init_size, core_size;
 294
 295        /* The size of the executable code in each section.  */
 296        unsigned int init_text_size, core_text_size;
 297
 298        /* Size of RO sections of the module (text+rodata) */
 299        unsigned int init_ro_size, core_ro_size;
 300
 301        /* Arch-specific module values */
 302        struct mod_arch_specific arch;
 303
 304        unsigned int taints;    /* same bits as kernel:tainted */
 305
 306#ifdef CONFIG_GENERIC_BUG
 307        /* Support for BUG */
 308        unsigned num_bugs;
 309        struct list_head bug_list;
 310        struct bug_entry *bug_table;
 311#endif
 312
 313#ifdef CONFIG_KALLSYMS
 314        /*
 315         * We keep the symbol and string tables for kallsyms.
 316         * The core_* fields below are temporary, loader-only (they
 317         * could really be discarded after module init).
 318         */
 319        Elf_Sym *symtab, *core_symtab;
 320        unsigned int num_symtab, core_num_syms;
 321        char *strtab, *core_strtab;
 322
 323        /* Section attributes */
 324        struct module_sect_attrs *sect_attrs;
 325
 326        /* Notes attributes */
 327        struct module_notes_attrs *notes_attrs;
 328#endif
 329
 330        /* The command line arguments (may be mangled).  People like
 331           keeping pointers to this stuff */
 332        char *args;
 333
 334#ifdef CONFIG_SMP
 335        /* Per-cpu data. */
 336        void __percpu *percpu;
 337        unsigned int percpu_size;
 338#endif
 339
 340#ifdef CONFIG_TRACEPOINTS
 341        unsigned int num_tracepoints;
 342        struct tracepoint * const *tracepoints_ptrs;
 343#endif
 344#ifdef HAVE_JUMP_LABEL
 345        struct jump_entry *jump_entries;
 346        unsigned int num_jump_entries;
 347#endif
 348#ifdef CONFIG_TRACING
 349        unsigned int num_trace_bprintk_fmt;
 350        const char **trace_bprintk_fmt_start;
 351#endif
 352#ifdef CONFIG_EVENT_TRACING
 353        struct ftrace_event_call **trace_events;
 354        unsigned int num_trace_events;
 355#endif
 356#ifdef CONFIG_FTRACE_MCOUNT_RECORD
 357        unsigned int num_ftrace_callsites;
 358        unsigned long *ftrace_callsites;
 359#endif
 360
 361#ifdef CONFIG_MODULE_UNLOAD
 362        /* What modules depend on me? */
 363        struct list_head source_list;
 364        /* What modules do I depend on? */
 365        struct list_head target_list;
 366
 367        /* Destruction function. */
 368        void (*exit)(void);
 369
 370        struct module_ref __percpu *refptr;
 371#endif
 372
 373#ifdef CONFIG_CONSTRUCTORS
 374        /* Constructor functions. */
 375        ctor_fn_t *ctors;
 376        unsigned int num_ctors;
 377#endif
 378};
 379#ifndef MODULE_ARCH_INIT
 380#define MODULE_ARCH_INIT {}
 381#endif
 382
 383extern struct mutex module_mutex;
 384
 385/* FIXME: It'd be nice to isolate modules during init, too, so they
 386   aren't used before they (may) fail.  But presently too much code
 387   (IDE & SCSI) require entry into the module during init.*/
 388static inline int module_is_live(struct module *mod)
 389{
 390        return mod->state != MODULE_STATE_GOING;
 391}
 392
 393struct module *__module_text_address(unsigned long addr);
 394struct module *__module_address(unsigned long addr);
 395bool is_module_address(unsigned long addr);
 396bool is_module_percpu_address(unsigned long addr);
 397bool is_module_text_address(unsigned long addr);
 398
 399static inline bool within_module_core(unsigned long addr,
 400                                      const struct module *mod)
 401{
 402        return (unsigned long)mod->module_core <= addr &&
 403               addr < (unsigned long)mod->module_core + mod->core_size;
 404}
 405
 406static inline bool within_module_init(unsigned long addr,
 407                                      const struct module *mod)
 408{
 409        return (unsigned long)mod->module_init <= addr &&
 410               addr < (unsigned long)mod->module_init + mod->init_size;
 411}
 412
 413static inline bool within_module(unsigned long addr, const struct module *mod)
 414{
 415        return within_module_init(addr, mod) || within_module_core(addr, mod);
 416}
 417
 418/* Search for module by name: must hold module_mutex. */
 419struct module *find_module(const char *name);
 420
 421struct symsearch {
 422        const struct kernel_symbol *start, *stop;
 423        const unsigned long *crcs;
 424        enum {
 425                NOT_GPL_ONLY,
 426                GPL_ONLY,
 427                WILL_BE_GPL_ONLY,
 428        } licence;
 429        bool unused;
 430};
 431
 432/* Search for an exported symbol by name. */
 433const struct kernel_symbol *find_symbol(const char *name,
 434                                        struct module **owner,
 435                                        const unsigned long **crc,
 436                                        bool gplok,
 437                                        bool warn);
 438
 439/* Walk the exported symbol table */
 440bool each_symbol_section(bool (*fn)(const struct symsearch *arr,
 441                                    struct module *owner,
 442                                    void *data), void *data);
 443
 444/* Returns 0 and fills in value, defined and namebuf, or -ERANGE if
 445   symnum out of range. */
 446int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
 447                        char *name, char *module_name, int *exported);
 448
 449/* Look for this name: can be of form module:name. */
 450unsigned long module_kallsyms_lookup_name(const char *name);
 451
 452int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
 453                                             struct module *, unsigned long),
 454                                   void *data);
 455
 456extern void __module_put_and_exit(struct module *mod, long code)
 457        __attribute__((noreturn));
 458#define module_put_and_exit(code) __module_put_and_exit(THIS_MODULE, code)
 459
 460#ifdef CONFIG_MODULE_UNLOAD
 461unsigned long module_refcount(struct module *mod);
 462void __symbol_put(const char *symbol);
 463#define symbol_put(x) __symbol_put(VMLINUX_SYMBOL_STR(x))
 464void symbol_put_addr(void *addr);
 465
 466/* Sometimes we know we already have a refcount, and it's easier not
 467   to handle the error case (which only happens with rmmod --wait). */
 468extern void __module_get(struct module *module);
 469
 470/* This is the Right Way to get a module: if it fails, it's being removed,
 471 * so pretend it's not there. */
 472extern bool try_module_get(struct module *module);
 473
 474extern void module_put(struct module *module);
 475
 476#else /*!CONFIG_MODULE_UNLOAD*/
 477static inline int try_module_get(struct module *module)
 478{
 479        return !module || module_is_live(module);
 480}
 481static inline void module_put(struct module *module)
 482{
 483}
 484static inline void __module_get(struct module *module)
 485{
 486}
 487#define symbol_put(x) do { } while (0)
 488#define symbol_put_addr(p) do { } while (0)
 489
 490#endif /* CONFIG_MODULE_UNLOAD */
 491int ref_module(struct module *a, struct module *b);
 492
 493/* This is a #define so the string doesn't get put in every .o file */
 494#define module_name(mod)                        \
 495({                                              \
 496        struct module *__mod = (mod);           \
 497        __mod ? __mod->name : "kernel";         \
 498})
 499
 500/* For kallsyms to ask for address resolution.  namebuf should be at
 501 * least KSYM_NAME_LEN long: a pointer to namebuf is returned if
 502 * found, otherwise NULL. */
 503const char *module_address_lookup(unsigned long addr,
 504                            unsigned long *symbolsize,
 505                            unsigned long *offset,
 506                            char **modname,
 507                            char *namebuf);
 508int lookup_module_symbol_name(unsigned long addr, char *symname);
 509int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name);
 510
 511/* For extable.c to search modules' exception tables. */
 512const struct exception_table_entry *search_module_extables(unsigned long addr);
 513
 514int register_module_notifier(struct notifier_block *nb);
 515int unregister_module_notifier(struct notifier_block *nb);
 516
 517extern void print_modules(void);
 518
 519#else /* !CONFIG_MODULES... */
 520
 521/* Given an address, look for it in the exception tables. */
 522static inline const struct exception_table_entry *
 523search_module_extables(unsigned long addr)
 524{
 525        return NULL;
 526}
 527
 528static inline struct module *__module_address(unsigned long addr)
 529{
 530        return NULL;
 531}
 532
 533static inline struct module *__module_text_address(unsigned long addr)
 534{
 535        return NULL;
 536}
 537
 538static inline bool is_module_address(unsigned long addr)
 539{
 540        return false;
 541}
 542
 543static inline bool is_module_percpu_address(unsigned long addr)
 544{
 545        return false;
 546}
 547
 548static inline bool is_module_text_address(unsigned long addr)
 549{
 550        return false;
 551}
 552
 553/* Get/put a kernel symbol (calls should be symmetric) */
 554#define symbol_get(x) ({ extern typeof(x) x __attribute__((weak)); &(x); })
 555#define symbol_put(x) do { } while (0)
 556#define symbol_put_addr(x) do { } while (0)
 557
 558static inline void __module_get(struct module *module)
 559{
 560}
 561
 562static inline int try_module_get(struct module *module)
 563{
 564        return 1;
 565}
 566
 567static inline void module_put(struct module *module)
 568{
 569}
 570
 571#define module_name(mod) "kernel"
 572
 573/* For kallsyms to ask for address resolution.  NULL means not found. */
 574static inline const char *module_address_lookup(unsigned long addr,
 575                                          unsigned long *symbolsize,
 576                                          unsigned long *offset,
 577                                          char **modname,
 578                                          char *namebuf)
 579{
 580        return NULL;
 581}
 582
 583static inline int lookup_module_symbol_name(unsigned long addr, char *symname)
 584{
 585        return -ERANGE;
 586}
 587
 588static inline int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name)
 589{
 590        return -ERANGE;
 591}
 592
 593static inline int module_get_kallsym(unsigned int symnum, unsigned long *value,
 594                                        char *type, char *name,
 595                                        char *module_name, int *exported)
 596{
 597        return -ERANGE;
 598}
 599
 600static inline unsigned long module_kallsyms_lookup_name(const char *name)
 601{
 602        return 0;
 603}
 604
 605static inline int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
 606                                                           struct module *,
 607                                                           unsigned long),
 608                                                 void *data)
 609{
 610        return 0;
 611}
 612
 613static inline int register_module_notifier(struct notifier_block *nb)
 614{
 615        /* no events will happen anyway, so this can always succeed */
 616        return 0;
 617}
 618
 619static inline int unregister_module_notifier(struct notifier_block *nb)
 620{
 621        return 0;
 622}
 623
 624#define module_put_and_exit(code) do_exit(code)
 625
 626static inline void print_modules(void)
 627{
 628}
 629#endif /* CONFIG_MODULES */
 630
 631#ifdef CONFIG_SYSFS
 632extern struct kset *module_kset;
 633extern struct kobj_type module_ktype;
 634extern int module_sysfs_initialized;
 635#endif /* CONFIG_SYSFS */
 636
 637#define symbol_request(x) try_then_request_module(symbol_get(x), "symbol:" #x)
 638
 639/* BELOW HERE ALL THESE ARE OBSOLETE AND WILL VANISH */
 640
 641#define __MODULE_STRING(x) __stringify(x)
 642
 643#ifdef CONFIG_DEBUG_SET_MODULE_RONX
 644extern void set_all_modules_text_rw(void);
 645extern void set_all_modules_text_ro(void);
 646#else
 647static inline void set_all_modules_text_rw(void) { }
 648static inline void set_all_modules_text_ro(void) { }
 649#endif
 650
 651#ifdef CONFIG_GENERIC_BUG
 652void module_bug_finalize(const Elf_Ehdr *, const Elf_Shdr *,
 653                         struct module *);
 654void module_bug_cleanup(struct module *);
 655
 656#else   /* !CONFIG_GENERIC_BUG */
 657
 658static inline void module_bug_finalize(const Elf_Ehdr *hdr,
 659                                        const Elf_Shdr *sechdrs,
 660                                        struct module *mod)
 661{
 662}
 663static inline void module_bug_cleanup(struct module *mod) {}
 664#endif  /* CONFIG_GENERIC_BUG */
 665
 666#endif /* _LINUX_MODULE_H */
 667