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/* 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{
  34        unsigned long crc;
  35        char name[MODULE_NAME_LEN];
  36};
  37
  38struct module;
  39
  40struct module_kobject {
  41        struct kobject kobj;
  42        struct module *mod;
  43        struct kobject *drivers_dir;
  44        struct module_param_attrs *mp;
  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#ifdef MODULE
  86#define MODULE_GENERIC_TABLE(gtype,name)                        \
  87extern const struct gtype##_id __mod_##gtype##_table            \
  88  __attribute__ ((unused, alias(__stringify(name))))
  89
  90#else  /* !MODULE */
  91#define MODULE_GENERIC_TABLE(gtype,name)
  92#endif
  93
  94/* Generic info of form tag = "info" */
  95#define MODULE_INFO(tag, info) __MODULE_INFO(tag, tag, info)
  96
  97/* For userspace: you can also call me... */
  98#define MODULE_ALIAS(_alias) MODULE_INFO(alias, _alias)
  99
 100/*
 101 * The following license idents are currently accepted as indicating free
 102 * software modules
 103 *
 104 *      "GPL"                           [GNU Public License v2 or later]
 105 *      "GPL v2"                        [GNU Public License v2]
 106 *      "GPL and additional rights"     [GNU Public License v2 rights and more]
 107 *      "Dual BSD/GPL"                  [GNU Public License v2
 108 *                                       or BSD license choice]
 109 *      "Dual MIT/GPL"                  [GNU Public License v2
 110 *                                       or MIT license choice]
 111 *      "Dual MPL/GPL"                  [GNU Public License v2
 112 *                                       or Mozilla license choice]
 113 *
 114 * The following other idents are available
 115 *
 116 *      "Proprietary"                   [Non free products]
 117 *
 118 * There are dual licensed components, but when running with Linux it is the
 119 * GPL that is relevant so this is a non issue. Similarly LGPL linked with GPL
 120 * is a GPL combined work.
 121 *
 122 * This exists for several reasons
 123 * 1.   So modinfo can show license info for users wanting to vet their setup 
 124 *      is free
 125 * 2.   So the community can ignore bug reports including proprietary modules
 126 * 3.   So vendors can do likewise based on their own policies
 127 */
 128#define MODULE_LICENSE(_license) MODULE_INFO(license, _license)
 129
 130/*
 131 * Author(s), use "Name <email>" or just "Name", for multiple
 132 * authors use multiple MODULE_AUTHOR() statements/lines.
 133 */
 134#define MODULE_AUTHOR(_author) MODULE_INFO(author, _author)
 135  
 136/* What your module does. */
 137#define MODULE_DESCRIPTION(_description) MODULE_INFO(description, _description)
 138
 139#define MODULE_DEVICE_TABLE(type,name)          \
 140  MODULE_GENERIC_TABLE(type##_device,name)
 141
 142/* Version of form [<epoch>:]<version>[-<extra-version>].
 143   Or for CVS/RCS ID version, everything but the number is stripped.
 144  <epoch>: A (small) unsigned integer which allows you to start versions
 145           anew. If not mentioned, it's zero.  eg. "2:1.0" is after
 146           "1:2.0".
 147  <version>: The <version> may contain only alphanumerics and the
 148           character `.'.  Ordered by numeric sort for numeric parts,
 149           ascii sort for ascii parts (as per RPM or DEB algorithm).
 150  <extraversion>: Like <version>, but inserted for local
 151           customizations, eg "rh3" or "rusty1".
 152
 153  Using this automatically adds a checksum of the .c files and the
 154  local headers in "srcversion".
 155*/
 156
 157#if defined(MODULE) || !defined(CONFIG_SYSFS)
 158#define MODULE_VERSION(_version) MODULE_INFO(version, _version)
 159#else
 160#define MODULE_VERSION(_version)                                        \
 161        static struct module_version_attribute ___modver_attr = {       \
 162                .mattr  = {                                             \
 163                        .attr   = {                                     \
 164                                .name   = "version",                    \
 165                                .mode   = S_IRUGO,                      \
 166                        },                                              \
 167                        .show   = __modver_version_show,                \
 168                },                                                      \
 169                .module_name    = KBUILD_MODNAME,                       \
 170                .version        = _version,                             \
 171        };                                                              \
 172        static const struct module_version_attribute                    \
 173        __used __attribute__ ((__section__ ("__modver")))               \
 174        * __moduleparam_const __modver_attr = &___modver_attr
 175#endif
 176
 177/* Optional firmware file (or files) needed by the module
 178 * format is simply firmware file name.  Multiple firmware
 179 * files require multiple MODULE_FIRMWARE() specifiers */
 180#define MODULE_FIRMWARE(_firmware) MODULE_INFO(firmware, _firmware)
 181
 182/* Given an address, look for it in the exception tables */
 183const struct exception_table_entry *search_exception_tables(unsigned long add);
 184
 185struct notifier_block;
 186
 187#ifdef CONFIG_MODULES
 188
 189extern int modules_disabled; /* for sysctl */
 190/* Get/put a kernel symbol (calls must be symmetric) */
 191void *__symbol_get(const char *symbol);
 192void *__symbol_get_gpl(const char *symbol);
 193#define symbol_get(x) ((typeof(&x))(__symbol_get(VMLINUX_SYMBOL_STR(x))))
 194
 195/* modules using other modules: kdb wants to see this. */
 196struct module_use {
 197        struct list_head source_list;
 198        struct list_head target_list;
 199        struct module *source, *target;
 200};
 201
 202enum module_state {
 203        MODULE_STATE_LIVE,      /* Normal state. */
 204        MODULE_STATE_COMING,    /* Full formed, running module_init. */
 205        MODULE_STATE_GOING,     /* Going away. */
 206        MODULE_STATE_UNFORMED,  /* Still setting it up. */
 207};
 208
 209/**
 210 * struct module_ref - per cpu module reference counts
 211 * @incs: number of module get on this cpu
 212 * @decs: number of module put on this cpu
 213 *
 214 * We force an alignment on 8 or 16 bytes, so that alloc_percpu()
 215 * put @incs/@decs in same cache line, with no extra memory cost,
 216 * since alloc_percpu() is fine grained.
 217 */
 218struct module_ref {
 219        unsigned long incs;
 220        unsigned long decs;
 221} __attribute((aligned(2 * sizeof(unsigned long))));
 222
 223struct module
 224{
 225        enum module_state state;
 226
 227        /* Member of list of modules */
 228        struct list_head list;
 229
 230        /* Unique handle for this module */
 231        char name[MODULE_NAME_LEN];
 232
 233        /* Sysfs stuff. */
 234        struct module_kobject mkobj;
 235        struct module_attribute *modinfo_attrs;
 236        const char *version;
 237        const char *srcversion;
 238        struct kobject *holders_dir;
 239
 240        /* Exported symbols */
 241        const struct kernel_symbol *syms;
 242        const unsigned long *crcs;
 243        unsigned int num_syms;
 244
 245        /* Kernel parameters. */
 246        struct kernel_param *kp;
 247        unsigned int num_kp;
 248
 249        /* GPL-only exported symbols. */
 250        unsigned int num_gpl_syms;
 251        const struct kernel_symbol *gpl_syms;
 252        const unsigned long *gpl_crcs;
 253
 254#ifdef CONFIG_UNUSED_SYMBOLS
 255        /* unused exported symbols. */
 256        const struct kernel_symbol *unused_syms;
 257        const unsigned long *unused_crcs;
 258        unsigned int num_unused_syms;
 259
 260        /* GPL-only, unused exported symbols. */
 261        unsigned int num_unused_gpl_syms;
 262        const struct kernel_symbol *unused_gpl_syms;
 263        const unsigned long *unused_gpl_crcs;
 264#endif
 265
 266#ifdef CONFIG_MODULE_SIG
 267        /* Signature was verified. */
 268        bool sig_ok;
 269#endif
 270
 271        /* symbols that will be GPL-only in the near future. */
 272        const struct kernel_symbol *gpl_future_syms;
 273        const unsigned long *gpl_future_crcs;
 274        unsigned int num_gpl_future_syms;
 275
 276        /* Exception table */
 277        unsigned int num_exentries;
 278        struct exception_table_entry *extable;
 279
 280        /* Startup function. */
 281        int (*init)(void);
 282
 283        /* If this is non-NULL, vfree after init() returns */
 284        void *module_init;
 285
 286        /* Here is the actual code + data, vfree'd on unload. */
 287        void *module_core;
 288
 289        /* Here are the sizes of the init and core sections */
 290        unsigned int init_size, core_size;
 291
 292        /* The size of the executable code in each section.  */
 293        unsigned int init_text_size, core_text_size;
 294
 295        /* Size of RO sections of the module (text+rodata) */
 296        unsigned int init_ro_size, core_ro_size;
 297
 298        /* Arch-specific module values */
 299        struct mod_arch_specific arch;
 300
 301        unsigned int taints;    /* same bits as kernel:tainted */
 302
 303#ifdef CONFIG_GENERIC_BUG
 304        /* Support for BUG */
 305        unsigned num_bugs;
 306        struct list_head bug_list;
 307        struct bug_entry *bug_table;
 308#endif
 309
 310#ifdef CONFIG_KALLSYMS
 311        /*
 312         * We keep the symbol and string tables for kallsyms.
 313         * The core_* fields below are temporary, loader-only (they
 314         * could really be discarded after module init).
 315         */
 316        Elf_Sym *symtab, *core_symtab;
 317        unsigned int num_symtab, core_num_syms;
 318        char *strtab, *core_strtab;
 319
 320        /* Section attributes */
 321        struct module_sect_attrs *sect_attrs;
 322
 323        /* Notes attributes */
 324        struct module_notes_attrs *notes_attrs;
 325#endif
 326
 327        /* The command line arguments (may be mangled).  People like
 328           keeping pointers to this stuff */
 329        char *args;
 330
 331#ifdef CONFIG_SMP
 332        /* Per-cpu data. */
 333        void __percpu *percpu;
 334        unsigned int percpu_size;
 335#endif
 336
 337#ifdef CONFIG_TRACEPOINTS
 338        unsigned int num_tracepoints;
 339        struct tracepoint * const *tracepoints_ptrs;
 340#endif
 341#ifdef HAVE_JUMP_LABEL
 342        struct jump_entry *jump_entries;
 343        unsigned int num_jump_entries;
 344#endif
 345#ifdef CONFIG_TRACING
 346        unsigned int num_trace_bprintk_fmt;
 347        const char **trace_bprintk_fmt_start;
 348#endif
 349#ifdef CONFIG_EVENT_TRACING
 350        struct ftrace_event_call **trace_events;
 351        unsigned int num_trace_events;
 352#endif
 353#ifdef CONFIG_FTRACE_MCOUNT_RECORD
 354        unsigned int num_ftrace_callsites;
 355        unsigned long *ftrace_callsites;
 356#endif
 357
 358#ifdef CONFIG_MODULE_UNLOAD
 359        /* What modules depend on me? */
 360        struct list_head source_list;
 361        /* What modules do I depend on? */
 362        struct list_head target_list;
 363
 364        /* Who is waiting for us to be unloaded */
 365        struct task_struct *waiter;
 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 int within_module_core(unsigned long addr, const struct module *mod)
 400{
 401        return (unsigned long)mod->module_core <= addr &&
 402               addr < (unsigned long)mod->module_core + mod->core_size;
 403}
 404
 405static inline int within_module_init(unsigned long addr, const struct module *mod)
 406{
 407        return (unsigned long)mod->module_init <= addr &&
 408               addr < (unsigned long)mod->module_init + mod->init_size;
 409}
 410
 411/* Search for module by name: must hold module_mutex. */
 412struct module *find_module(const char *name);
 413
 414struct symsearch {
 415        const struct kernel_symbol *start, *stop;
 416        const unsigned long *crcs;
 417        enum {
 418                NOT_GPL_ONLY,
 419                GPL_ONLY,
 420                WILL_BE_GPL_ONLY,
 421        } licence;
 422        bool unused;
 423};
 424
 425/* Search for an exported symbol by name. */
 426const struct kernel_symbol *find_symbol(const char *name,
 427                                        struct module **owner,
 428                                        const unsigned long **crc,
 429                                        bool gplok,
 430                                        bool warn);
 431
 432/* Walk the exported symbol table */
 433bool each_symbol_section(bool (*fn)(const struct symsearch *arr,
 434                                    struct module *owner,
 435                                    void *data), void *data);
 436
 437/* Returns 0 and fills in value, defined and namebuf, or -ERANGE if
 438   symnum out of range. */
 439int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
 440                        char *name, char *module_name, int *exported);
 441
 442/* Look for this name: can be of form module:name. */
 443unsigned long module_kallsyms_lookup_name(const char *name);
 444
 445int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
 446                                             struct module *, unsigned long),
 447                                   void *data);
 448
 449extern void __module_put_and_exit(struct module *mod, long code)
 450        __attribute__((noreturn));
 451#define module_put_and_exit(code) __module_put_and_exit(THIS_MODULE, code);
 452
 453#ifdef CONFIG_MODULE_UNLOAD
 454unsigned long module_refcount(struct module *mod);
 455void __symbol_put(const char *symbol);
 456#define symbol_put(x) __symbol_put(VMLINUX_SYMBOL_STR(x))
 457void symbol_put_addr(void *addr);
 458
 459/* Sometimes we know we already have a refcount, and it's easier not
 460   to handle the error case (which only happens with rmmod --wait). */
 461extern void __module_get(struct module *module);
 462
 463/* This is the Right Way to get a module: if it fails, it's being removed,
 464 * so pretend it's not there. */
 465extern bool try_module_get(struct module *module);
 466
 467extern void module_put(struct module *module);
 468
 469#else /*!CONFIG_MODULE_UNLOAD*/
 470static inline int try_module_get(struct module *module)
 471{
 472        return !module || module_is_live(module);
 473}
 474static inline void module_put(struct module *module)
 475{
 476}
 477static inline void __module_get(struct module *module)
 478{
 479}
 480#define symbol_put(x) do { } while(0)
 481#define symbol_put_addr(p) do { } while(0)
 482
 483#endif /* CONFIG_MODULE_UNLOAD */
 484int ref_module(struct module *a, struct module *b);
 485
 486/* This is a #define so the string doesn't get put in every .o file */
 487#define module_name(mod)                        \
 488({                                              \
 489        struct module *__mod = (mod);           \
 490        __mod ? __mod->name : "kernel";         \
 491})
 492
 493/* For kallsyms to ask for address resolution.  namebuf should be at
 494 * least KSYM_NAME_LEN long: a pointer to namebuf is returned if
 495 * found, otherwise NULL. */
 496const char *module_address_lookup(unsigned long addr,
 497                            unsigned long *symbolsize,
 498                            unsigned long *offset,
 499                            char **modname,
 500                            char *namebuf);
 501int lookup_module_symbol_name(unsigned long addr, char *symname);
 502int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name);
 503
 504/* For extable.c to search modules' exception tables. */
 505const struct exception_table_entry *search_module_extables(unsigned long addr);
 506
 507int register_module_notifier(struct notifier_block * nb);
 508int unregister_module_notifier(struct notifier_block * nb);
 509
 510extern void print_modules(void);
 511
 512#else /* !CONFIG_MODULES... */
 513
 514/* Given an address, look for it in the exception tables. */
 515static inline const struct exception_table_entry *
 516search_module_extables(unsigned long addr)
 517{
 518        return NULL;
 519}
 520
 521static inline struct module *__module_address(unsigned long addr)
 522{
 523        return NULL;
 524}
 525
 526static inline struct module *__module_text_address(unsigned long addr)
 527{
 528        return NULL;
 529}
 530
 531static inline bool is_module_address(unsigned long addr)
 532{
 533        return false;
 534}
 535
 536static inline bool is_module_percpu_address(unsigned long addr)
 537{
 538        return false;
 539}
 540
 541static inline bool is_module_text_address(unsigned long addr)
 542{
 543        return false;
 544}
 545
 546/* Get/put a kernel symbol (calls should be symmetric) */
 547#define symbol_get(x) ({ extern typeof(x) x __attribute__((weak)); &(x); })
 548#define symbol_put(x) do { } while(0)
 549#define symbol_put_addr(x) do { } while(0)
 550
 551static inline void __module_get(struct module *module)
 552{
 553}
 554
 555static inline int try_module_get(struct module *module)
 556{
 557        return 1;
 558}
 559
 560static inline void module_put(struct module *module)
 561{
 562}
 563
 564#define module_name(mod) "kernel"
 565
 566/* For kallsyms to ask for address resolution.  NULL means not found. */
 567static inline const char *module_address_lookup(unsigned long addr,
 568                                          unsigned long *symbolsize,
 569                                          unsigned long *offset,
 570                                          char **modname,
 571                                          char *namebuf)
 572{
 573        return NULL;
 574}
 575
 576static inline int lookup_module_symbol_name(unsigned long addr, char *symname)
 577{
 578        return -ERANGE;
 579}
 580
 581static inline int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name)
 582{
 583        return -ERANGE;
 584}
 585
 586static inline int module_get_kallsym(unsigned int symnum, unsigned long *value,
 587                                        char *type, char *name,
 588                                        char *module_name, int *exported)
 589{
 590        return -ERANGE;
 591}
 592
 593static inline unsigned long module_kallsyms_lookup_name(const char *name)
 594{
 595        return 0;
 596}
 597
 598static inline int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
 599                                                           struct module *,
 600                                                           unsigned long),
 601                                                 void *data)
 602{
 603        return 0;
 604}
 605
 606static inline int register_module_notifier(struct notifier_block * nb)
 607{
 608        /* no events will happen anyway, so this can always succeed */
 609        return 0;
 610}
 611
 612static inline int unregister_module_notifier(struct notifier_block * nb)
 613{
 614        return 0;
 615}
 616
 617#define module_put_and_exit(code) do_exit(code)
 618
 619static inline void print_modules(void)
 620{
 621}
 622#endif /* CONFIG_MODULES */
 623
 624#ifdef CONFIG_SYSFS
 625extern struct kset *module_kset;
 626extern struct kobj_type module_ktype;
 627extern int module_sysfs_initialized;
 628#endif /* CONFIG_SYSFS */
 629
 630#define symbol_request(x) try_then_request_module(symbol_get(x), "symbol:" #x)
 631
 632/* BELOW HERE ALL THESE ARE OBSOLETE AND WILL VANISH */
 633
 634#define __MODULE_STRING(x) __stringify(x)
 635
 636#ifdef CONFIG_DEBUG_SET_MODULE_RONX
 637extern void set_all_modules_text_rw(void);
 638extern void set_all_modules_text_ro(void);
 639#else
 640static inline void set_all_modules_text_rw(void) { }
 641static inline void set_all_modules_text_ro(void) { }
 642#endif
 643
 644#ifdef CONFIG_GENERIC_BUG
 645void module_bug_finalize(const Elf_Ehdr *, const Elf_Shdr *,
 646                         struct module *);
 647void module_bug_cleanup(struct module *);
 648
 649#else   /* !CONFIG_GENERIC_BUG */
 650
 651static inline void module_bug_finalize(const Elf_Ehdr *hdr,
 652                                        const Elf_Shdr *sechdrs,
 653                                        struct module *mod)
 654{
 655}
 656static inline void module_bug_cleanup(struct module *mod) {}
 657#endif  /* CONFIG_GENERIC_BUG */
 658
 659#endif /* _LINUX_MODULE_H */
 660