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/tracepoint.h>
  19#include <linux/export.h>
  20
  21#include <linux/percpu.h>
  22#include <asm/module.h>
  23
  24/* Not Yet Implemented */
  25#define MODULE_SUPPORTED_DEVICE(name)
  26
  27#define MODULE_NAME_LEN MAX_PARAM_PREFIX_LEN
  28
  29struct modversion_info
  30{
  31        unsigned long crc;
  32        char name[MODULE_NAME_LEN];
  33};
  34
  35struct module;
  36
  37struct module_kobject {
  38        struct kobject kobj;
  39        struct module *mod;
  40        struct kobject *drivers_dir;
  41        struct module_param_attrs *mp;
  42};
  43
  44struct module_attribute {
  45        struct attribute attr;
  46        ssize_t (*show)(struct module_attribute *, struct module_kobject *,
  47                        char *);
  48        ssize_t (*store)(struct module_attribute *, struct module_kobject *,
  49                         const char *, size_t count);
  50        void (*setup)(struct module *, const char *);
  51        int (*test)(struct module *);
  52        void (*free)(struct module *);
  53};
  54
  55struct module_version_attribute {
  56        struct module_attribute mattr;
  57        const char *module_name;
  58        const char *version;
  59} __attribute__ ((__aligned__(sizeof(void *))));
  60
  61extern ssize_t __modver_version_show(struct module_attribute *,
  62                                     struct module_kobject *, char *);
  63
  64extern struct module_attribute module_uevent;
  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);
  80void trim_init_extable(struct module *m);
  81
  82#ifdef MODULE
  83#define MODULE_GENERIC_TABLE(gtype,name)                        \
  84extern const struct gtype##_id __mod_##gtype##_table            \
  85  __attribute__ ((unused, alias(__stringify(name))))
  86
  87#else  /* !MODULE */
  88#define MODULE_GENERIC_TABLE(gtype,name)
  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/*
 128 * Author(s), use "Name <email>" or just "Name", for multiple
 129 * authors use multiple MODULE_AUTHOR() statements/lines.
 130 */
 131#define MODULE_AUTHOR(_author) MODULE_INFO(author, _author)
 132  
 133/* What your module does. */
 134#define MODULE_DESCRIPTION(_description) MODULE_INFO(description, _description)
 135
 136#define MODULE_DEVICE_TABLE(type,name)          \
 137  MODULE_GENERIC_TABLE(type##_device,name)
 138
 139/* Version of form [<epoch>:]<version>[-<extra-version>].
 140   Or for CVS/RCS ID version, everything but the number is stripped.
 141  <epoch>: A (small) unsigned integer which allows you to start versions
 142           anew. If not mentioned, it's zero.  eg. "2:1.0" is after
 143           "1:2.0".
 144  <version>: The <version> may contain only alphanumerics and the
 145           character `.'.  Ordered by numeric sort for numeric parts,
 146           ascii sort for ascii parts (as per RPM or DEB algorithm).
 147  <extraversion>: Like <version>, but inserted for local
 148           customizations, eg "rh3" or "rusty1".
 149
 150  Using this automatically adds a checksum of the .c files and the
 151  local headers in "srcversion".
 152*/
 153
 154#if defined(MODULE) || !defined(CONFIG_SYSFS)
 155#define MODULE_VERSION(_version) MODULE_INFO(version, _version)
 156#else
 157#define MODULE_VERSION(_version)                                        \
 158        static struct module_version_attribute ___modver_attr = {       \
 159                .mattr  = {                                             \
 160                        .attr   = {                                     \
 161                                .name   = "version",                    \
 162                                .mode   = S_IRUGO,                      \
 163                        },                                              \
 164                        .show   = __modver_version_show,                \
 165                },                                                      \
 166                .module_name    = KBUILD_MODNAME,                       \
 167                .version        = _version,                             \
 168        };                                                              \
 169        static const struct module_version_attribute                    \
 170        __used __attribute__ ((__section__ ("__modver")))               \
 171        * __moduleparam_const __modver_attr = &___modver_attr
 172#endif
 173
 174/* Optional firmware file (or files) needed by the module
 175 * format is simply firmware file name.  Multiple firmware
 176 * files require multiple MODULE_FIRMWARE() specifiers */
 177#define MODULE_FIRMWARE(_firmware) MODULE_INFO(firmware, _firmware)
 178
 179/* Given an address, look for it in the exception tables */
 180const struct exception_table_entry *search_exception_tables(unsigned long add);
 181
 182struct notifier_block;
 183
 184#ifdef CONFIG_MODULES
 185
 186extern int modules_disabled; /* for sysctl */
 187/* Get/put a kernel symbol (calls must be symmetric) */
 188void *__symbol_get(const char *symbol);
 189void *__symbol_get_gpl(const char *symbol);
 190#define symbol_get(x) ((typeof(&x))(__symbol_get(MODULE_SYMBOL_PREFIX #x)))
 191
 192/* modules using other modules: kdb wants to see this. */
 193struct module_use {
 194        struct list_head source_list;
 195        struct list_head target_list;
 196        struct module *source, *target;
 197};
 198
 199enum module_state
 200{
 201        MODULE_STATE_LIVE,
 202        MODULE_STATE_COMING,
 203        MODULE_STATE_GOING,
 204};
 205
 206/**
 207 * struct module_ref - per cpu module reference counts
 208 * @incs: number of module get on this cpu
 209 * @decs: number of module put on this cpu
 210 *
 211 * We force an alignment on 8 or 16 bytes, so that alloc_percpu()
 212 * put @incs/@decs in same cache line, with no extra memory cost,
 213 * since alloc_percpu() is fine grained.
 214 */
 215struct module_ref {
 216        unsigned long incs;
 217        unsigned long decs;
 218} __attribute((aligned(2 * sizeof(unsigned long))));
 219
 220struct module
 221{
 222        enum module_state state;
 223
 224        /* Member of list of modules */
 225        struct list_head list;
 226
 227        /* Unique handle for this module */
 228        char name[MODULE_NAME_LEN];
 229
 230        /* Sysfs stuff. */
 231        struct module_kobject mkobj;
 232        struct module_attribute *modinfo_attrs;
 233        const char *version;
 234        const char *srcversion;
 235        struct kobject *holders_dir;
 236
 237        /* Exported symbols */
 238        const struct kernel_symbol *syms;
 239        const unsigned long *crcs;
 240        unsigned int num_syms;
 241
 242        /* Kernel parameters. */
 243        struct kernel_param *kp;
 244        unsigned int num_kp;
 245
 246        /* GPL-only exported symbols. */
 247        unsigned int num_gpl_syms;
 248        const struct kernel_symbol *gpl_syms;
 249        const unsigned long *gpl_crcs;
 250
 251#ifdef CONFIG_UNUSED_SYMBOLS
 252        /* unused exported symbols. */
 253        const struct kernel_symbol *unused_syms;
 254        const unsigned long *unused_crcs;
 255        unsigned int num_unused_syms;
 256
 257        /* GPL-only, unused exported symbols. */
 258        unsigned int num_unused_gpl_syms;
 259        const struct kernel_symbol *unused_gpl_syms;
 260        const unsigned long *unused_gpl_crcs;
 261#endif
 262
 263        /* symbols that will be GPL-only in the near future. */
 264        const struct kernel_symbol *gpl_future_syms;
 265        const unsigned long *gpl_future_crcs;
 266        unsigned int num_gpl_future_syms;
 267
 268        /* Exception table */
 269        unsigned int num_exentries;
 270        struct exception_table_entry *extable;
 271
 272        /* Startup function. */
 273        int (*init)(void);
 274
 275        /* If this is non-NULL, vfree after init() returns */
 276        void *module_init;
 277
 278        /* Here is the actual code + data, vfree'd on unload. */
 279        void *module_core;
 280
 281        /* Here are the sizes of the init and core sections */
 282        unsigned int init_size, core_size;
 283
 284        /* The size of the executable code in each section.  */
 285        unsigned int init_text_size, core_text_size;
 286
 287        /* Size of RO sections of the module (text+rodata) */
 288        unsigned int init_ro_size, core_ro_size;
 289
 290        /* Arch-specific module values */
 291        struct mod_arch_specific arch;
 292
 293        unsigned int taints;    /* same bits as kernel:tainted */
 294
 295#ifdef CONFIG_GENERIC_BUG
 296        /* Support for BUG */
 297        unsigned num_bugs;
 298        struct list_head bug_list;
 299        struct bug_entry *bug_table;
 300#endif
 301
 302#ifdef CONFIG_KALLSYMS
 303        /*
 304         * We keep the symbol and string tables for kallsyms.
 305         * The core_* fields below are temporary, loader-only (they
 306         * could really be discarded after module init).
 307         */
 308        Elf_Sym *symtab, *core_symtab;
 309        unsigned int num_symtab, core_num_syms;
 310        char *strtab, *core_strtab;
 311
 312        /* Section attributes */
 313        struct module_sect_attrs *sect_attrs;
 314
 315        /* Notes attributes */
 316        struct module_notes_attrs *notes_attrs;
 317#endif
 318
 319        /* The command line arguments (may be mangled).  People like
 320           keeping pointers to this stuff */
 321        char *args;
 322
 323#ifdef CONFIG_SMP
 324        /* Per-cpu data. */
 325        void __percpu *percpu;
 326        unsigned int percpu_size;
 327#endif
 328
 329#ifdef CONFIG_TRACEPOINTS
 330        unsigned int num_tracepoints;
 331        struct tracepoint * const *tracepoints_ptrs;
 332#endif
 333#ifdef HAVE_JUMP_LABEL
 334        struct jump_entry *jump_entries;
 335        unsigned int num_jump_entries;
 336#endif
 337#ifdef CONFIG_TRACING
 338        unsigned int num_trace_bprintk_fmt;
 339        const char **trace_bprintk_fmt_start;
 340#endif
 341#ifdef CONFIG_EVENT_TRACING
 342        struct ftrace_event_call **trace_events;
 343        unsigned int num_trace_events;
 344#endif
 345#ifdef CONFIG_FTRACE_MCOUNT_RECORD
 346        unsigned int num_ftrace_callsites;
 347        unsigned long *ftrace_callsites;
 348#endif
 349
 350#ifdef CONFIG_MODULE_UNLOAD
 351        /* What modules depend on me? */
 352        struct list_head source_list;
 353        /* What modules do I depend on? */
 354        struct list_head target_list;
 355
 356        /* Who is waiting for us to be unloaded */
 357        struct task_struct *waiter;
 358
 359        /* Destruction function. */
 360        void (*exit)(void);
 361
 362        struct module_ref __percpu *refptr;
 363#endif
 364
 365#ifdef CONFIG_CONSTRUCTORS
 366        /* Constructor functions. */
 367        ctor_fn_t *ctors;
 368        unsigned int num_ctors;
 369#endif
 370};
 371#ifndef MODULE_ARCH_INIT
 372#define MODULE_ARCH_INIT {}
 373#endif
 374
 375extern struct mutex module_mutex;
 376
 377/* FIXME: It'd be nice to isolate modules during init, too, so they
 378   aren't used before they (may) fail.  But presently too much code
 379   (IDE & SCSI) require entry into the module during init.*/
 380static inline int module_is_live(struct module *mod)
 381{
 382        return mod->state != MODULE_STATE_GOING;
 383}
 384
 385struct module *__module_text_address(unsigned long addr);
 386struct module *__module_address(unsigned long addr);
 387bool is_module_address(unsigned long addr);
 388bool is_module_percpu_address(unsigned long addr);
 389bool is_module_text_address(unsigned long addr);
 390
 391static inline int within_module_core(unsigned long addr, struct module *mod)
 392{
 393        return (unsigned long)mod->module_core <= addr &&
 394               addr < (unsigned long)mod->module_core + mod->core_size;
 395}
 396
 397static inline int within_module_init(unsigned long addr, struct module *mod)
 398{
 399        return (unsigned long)mod->module_init <= addr &&
 400               addr < (unsigned long)mod->module_init + mod->init_size;
 401}
 402
 403/* Search for module by name: must hold module_mutex. */
 404struct module *find_module(const char *name);
 405
 406struct symsearch {
 407        const struct kernel_symbol *start, *stop;
 408        const unsigned long *crcs;
 409        enum {
 410                NOT_GPL_ONLY,
 411                GPL_ONLY,
 412                WILL_BE_GPL_ONLY,
 413        } licence;
 414        bool unused;
 415};
 416
 417/* Search for an exported symbol by name. */
 418const struct kernel_symbol *find_symbol(const char *name,
 419                                        struct module **owner,
 420                                        const unsigned long **crc,
 421                                        bool gplok,
 422                                        bool warn);
 423
 424/* Walk the exported symbol table */
 425bool each_symbol_section(bool (*fn)(const struct symsearch *arr,
 426                                    struct module *owner,
 427                                    void *data), void *data);
 428
 429/* Returns 0 and fills in value, defined and namebuf, or -ERANGE if
 430   symnum out of range. */
 431int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
 432                        char *name, char *module_name, int *exported);
 433
 434/* Look for this name: can be of form module:name. */
 435unsigned long module_kallsyms_lookup_name(const char *name);
 436
 437int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
 438                                             struct module *, unsigned long),
 439                                   void *data);
 440
 441extern void __module_put_and_exit(struct module *mod, long code)
 442        __attribute__((noreturn));
 443#define module_put_and_exit(code) __module_put_and_exit(THIS_MODULE, code);
 444
 445#ifdef CONFIG_MODULE_UNLOAD
 446unsigned long module_refcount(struct module *mod);
 447void __symbol_put(const char *symbol);
 448#define symbol_put(x) __symbol_put(MODULE_SYMBOL_PREFIX #x)
 449void symbol_put_addr(void *addr);
 450
 451/* Sometimes we know we already have a refcount, and it's easier not
 452   to handle the error case (which only happens with rmmod --wait). */
 453extern void __module_get(struct module *module);
 454
 455/* This is the Right Way to get a module: if it fails, it's being removed,
 456 * so pretend it's not there. */
 457extern bool try_module_get(struct module *module);
 458
 459extern void module_put(struct module *module);
 460
 461#else /*!CONFIG_MODULE_UNLOAD*/
 462static inline int try_module_get(struct module *module)
 463{
 464        return !module || module_is_live(module);
 465}
 466static inline void module_put(struct module *module)
 467{
 468}
 469static inline void __module_get(struct module *module)
 470{
 471}
 472#define symbol_put(x) do { } while(0)
 473#define symbol_put_addr(p) do { } while(0)
 474
 475#endif /* CONFIG_MODULE_UNLOAD */
 476int ref_module(struct module *a, struct module *b);
 477
 478/* This is a #define so the string doesn't get put in every .o file */
 479#define module_name(mod)                        \
 480({                                              \
 481        struct module *__mod = (mod);           \
 482        __mod ? __mod->name : "kernel";         \
 483})
 484
 485/* For kallsyms to ask for address resolution.  namebuf should be at
 486 * least KSYM_NAME_LEN long: a pointer to namebuf is returned if
 487 * found, otherwise NULL. */
 488const char *module_address_lookup(unsigned long addr,
 489                            unsigned long *symbolsize,
 490                            unsigned long *offset,
 491                            char **modname,
 492                            char *namebuf);
 493int lookup_module_symbol_name(unsigned long addr, char *symname);
 494int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name);
 495
 496/* For extable.c to search modules' exception tables. */
 497const struct exception_table_entry *search_module_extables(unsigned long addr);
 498
 499int register_module_notifier(struct notifier_block * nb);
 500int unregister_module_notifier(struct notifier_block * nb);
 501
 502extern void print_modules(void);
 503
 504#else /* !CONFIG_MODULES... */
 505
 506/* Given an address, look for it in the exception tables. */
 507static inline const struct exception_table_entry *
 508search_module_extables(unsigned long addr)
 509{
 510        return NULL;
 511}
 512
 513static inline struct module *__module_address(unsigned long addr)
 514{
 515        return NULL;
 516}
 517
 518static inline struct module *__module_text_address(unsigned long addr)
 519{
 520        return NULL;
 521}
 522
 523static inline bool is_module_address(unsigned long addr)
 524{
 525        return false;
 526}
 527
 528static inline bool is_module_percpu_address(unsigned long addr)
 529{
 530        return false;
 531}
 532
 533static inline bool is_module_text_address(unsigned long addr)
 534{
 535        return false;
 536}
 537
 538/* Get/put a kernel symbol (calls should be symmetric) */
 539#define symbol_get(x) ({ extern typeof(x) x __attribute__((weak)); &(x); })
 540#define symbol_put(x) do { } while(0)
 541#define symbol_put_addr(x) do { } while(0)
 542
 543static inline void __module_get(struct module *module)
 544{
 545}
 546
 547static inline int try_module_get(struct module *module)
 548{
 549        return 1;
 550}
 551
 552static inline void module_put(struct module *module)
 553{
 554}
 555
 556#define module_name(mod) "kernel"
 557
 558/* For kallsyms to ask for address resolution.  NULL means not found. */
 559static inline const char *module_address_lookup(unsigned long addr,
 560                                          unsigned long *symbolsize,
 561                                          unsigned long *offset,
 562                                          char **modname,
 563                                          char *namebuf)
 564{
 565        return NULL;
 566}
 567
 568static inline int lookup_module_symbol_name(unsigned long addr, char *symname)
 569{
 570        return -ERANGE;
 571}
 572
 573static inline int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name)
 574{
 575        return -ERANGE;
 576}
 577
 578static inline int module_get_kallsym(unsigned int symnum, unsigned long *value,
 579                                        char *type, char *name,
 580                                        char *module_name, int *exported)
 581{
 582        return -ERANGE;
 583}
 584
 585static inline unsigned long module_kallsyms_lookup_name(const char *name)
 586{
 587        return 0;
 588}
 589
 590static inline int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
 591                                                           struct module *,
 592                                                           unsigned long),
 593                                                 void *data)
 594{
 595        return 0;
 596}
 597
 598static inline int register_module_notifier(struct notifier_block * nb)
 599{
 600        /* no events will happen anyway, so this can always succeed */
 601        return 0;
 602}
 603
 604static inline int unregister_module_notifier(struct notifier_block * nb)
 605{
 606        return 0;
 607}
 608
 609#define module_put_and_exit(code) do_exit(code)
 610
 611static inline void print_modules(void)
 612{
 613}
 614#endif /* CONFIG_MODULES */
 615
 616#ifdef CONFIG_SYSFS
 617extern struct kset *module_kset;
 618extern struct kobj_type module_ktype;
 619extern int module_sysfs_initialized;
 620#endif /* CONFIG_SYSFS */
 621
 622#define symbol_request(x) try_then_request_module(symbol_get(x), "symbol:" #x)
 623
 624/* BELOW HERE ALL THESE ARE OBSOLETE AND WILL VANISH */
 625
 626#define __MODULE_STRING(x) __stringify(x)
 627
 628#ifdef CONFIG_DEBUG_SET_MODULE_RONX
 629extern void set_all_modules_text_rw(void);
 630extern void set_all_modules_text_ro(void);
 631#else
 632static inline void set_all_modules_text_rw(void) { }
 633static inline void set_all_modules_text_ro(void) { }
 634#endif
 635
 636#ifdef CONFIG_GENERIC_BUG
 637void module_bug_finalize(const Elf_Ehdr *, const Elf_Shdr *,
 638                         struct module *);
 639void module_bug_cleanup(struct module *);
 640
 641#else   /* !CONFIG_GENERIC_BUG */
 642
 643static inline void module_bug_finalize(const Elf_Ehdr *hdr,
 644                                        const Elf_Shdr *sechdrs,
 645                                        struct module *mod)
 646{
 647}
 648static inline void module_bug_cleanup(struct module *mod) {}
 649#endif  /* CONFIG_GENERIC_BUG */
 650
 651#endif /* _LINUX_MODULE_H */
 652