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        struct completion *kobj_completion;
  46};
  47
  48struct module_attribute {
  49        struct attribute attr;
  50        ssize_t (*show)(struct module_attribute *, struct module_kobject *,
  51                        char *);
  52        ssize_t (*store)(struct module_attribute *, struct module_kobject *,
  53                         const char *, size_t count);
  54        void (*setup)(struct module *, const char *);
  55        int (*test)(struct module *);
  56        void (*free)(struct module *);
  57};
  58
  59struct module_version_attribute {
  60        struct module_attribute mattr;
  61        const char *module_name;
  62        const char *version;
  63} __attribute__ ((__aligned__(sizeof(void *))));
  64
  65extern ssize_t __modver_version_show(struct module_attribute *,
  66                                     struct module_kobject *, char *);
  67
  68extern struct module_attribute module_uevent;
  69
  70/* These are either module local, or the kernel's dummy ones. */
  71extern int init_module(void);
  72extern void cleanup_module(void);
  73
  74/* Archs provide a method of finding the correct exception table. */
  75struct exception_table_entry;
  76
  77const struct exception_table_entry *
  78search_extable(const struct exception_table_entry *first,
  79               const struct exception_table_entry *last,
  80               unsigned long value);
  81void sort_extable(struct exception_table_entry *start,
  82                  struct exception_table_entry *finish);
  83void sort_main_extable(void);
  84void trim_init_extable(struct module *m);
  85
  86#ifdef MODULE
  87#define MODULE_GENERIC_TABLE(gtype,name)                        \
  88extern const struct gtype##_id __mod_##gtype##_table            \
  89  __attribute__ ((unused, alias(__stringify(name))))
  90
  91#else  /* !MODULE */
  92#define MODULE_GENERIC_TABLE(gtype,name)
  93#endif
  94
  95/* Generic info of form tag = "info" */
  96#define MODULE_INFO(tag, info) __MODULE_INFO(tag, tag, info)
  97
  98/* For userspace: you can also call me... */
  99#define MODULE_ALIAS(_alias) MODULE_INFO(alias, _alias)
 100
 101/* Soft module dependencies. See man modprobe.d for details.
 102 * Example: MODULE_SOFTDEP("pre: module-foo module-bar post: module-baz")
 103 */
 104#define MODULE_SOFTDEP(_softdep) MODULE_INFO(softdep, _softdep)
 105
 106/*
 107 * The following license idents are currently accepted as indicating free
 108 * software modules
 109 *
 110 *      "GPL"                           [GNU Public License v2 or later]
 111 *      "GPL v2"                        [GNU Public License v2]
 112 *      "GPL and additional rights"     [GNU Public License v2 rights and more]
 113 *      "Dual BSD/GPL"                  [GNU Public License v2
 114 *                                       or BSD license choice]
 115 *      "Dual MIT/GPL"                  [GNU Public License v2
 116 *                                       or MIT license choice]
 117 *      "Dual MPL/GPL"                  [GNU Public License v2
 118 *                                       or Mozilla license choice]
 119 *
 120 * The following other idents are available
 121 *
 122 *      "Proprietary"                   [Non free products]
 123 *
 124 * There are dual licensed components, but when running with Linux it is the
 125 * GPL that is relevant so this is a non issue. Similarly LGPL linked with GPL
 126 * is a GPL combined work.
 127 *
 128 * This exists for several reasons
 129 * 1.   So modinfo can show license info for users wanting to vet their setup 
 130 *      is free
 131 * 2.   So the community can ignore bug reports including proprietary modules
 132 * 3.   So vendors can do likewise based on their own policies
 133 */
 134#define MODULE_LICENSE(_license) MODULE_INFO(license, _license)
 135
 136/*
 137 * Author(s), use "Name <email>" or just "Name", for multiple
 138 * authors use multiple MODULE_AUTHOR() statements/lines.
 139 */
 140#define MODULE_AUTHOR(_author) MODULE_INFO(author, _author)
 141  
 142/* What your module does. */
 143#define MODULE_DESCRIPTION(_description) MODULE_INFO(description, _description)
 144
 145#define MODULE_DEVICE_TABLE(type,name)          \
 146  MODULE_GENERIC_TABLE(type##_device,name)
 147
 148/* Version of form [<epoch>:]<version>[-<extra-version>].
 149   Or for CVS/RCS ID version, everything but the number is stripped.
 150  <epoch>: A (small) unsigned integer which allows you to start versions
 151           anew. If not mentioned, it's zero.  eg. "2:1.0" is after
 152           "1:2.0".
 153  <version>: The <version> may contain only alphanumerics and the
 154           character `.'.  Ordered by numeric sort for numeric parts,
 155           ascii sort for ascii parts (as per RPM or DEB algorithm).
 156  <extraversion>: Like <version>, but inserted for local
 157           customizations, eg "rh3" or "rusty1".
 158
 159  Using this automatically adds a checksum of the .c files and the
 160  local headers in "srcversion".
 161*/
 162
 163#if defined(MODULE) || !defined(CONFIG_SYSFS)
 164#define MODULE_VERSION(_version) MODULE_INFO(version, _version)
 165#else
 166#define MODULE_VERSION(_version)                                        \
 167        static struct module_version_attribute ___modver_attr = {       \
 168                .mattr  = {                                             \
 169                        .attr   = {                                     \
 170                                .name   = "version",                    \
 171                                .mode   = S_IRUGO,                      \
 172                        },                                              \
 173                        .show   = __modver_version_show,                \
 174                },                                                      \
 175                .module_name    = KBUILD_MODNAME,                       \
 176                .version        = _version,                             \
 177        };                                                              \
 178        static const struct module_version_attribute                    \
 179        __used __attribute__ ((__section__ ("__modver")))               \
 180        * __moduleparam_const __modver_attr = &___modver_attr
 181#endif
 182
 183/* Optional firmware file (or files) needed by the module
 184 * format is simply firmware file name.  Multiple firmware
 185 * files require multiple MODULE_FIRMWARE() specifiers */
 186#define MODULE_FIRMWARE(_firmware) MODULE_INFO(firmware, _firmware)
 187
 188/* Given an address, look for it in the exception tables */
 189const struct exception_table_entry *search_exception_tables(unsigned long add);
 190
 191struct notifier_block;
 192
 193#ifdef CONFIG_MODULES
 194
 195extern int modules_disabled; /* for sysctl */
 196/* Get/put a kernel symbol (calls must be symmetric) */
 197void *__symbol_get(const char *symbol);
 198void *__symbol_get_gpl(const char *symbol);
 199#define symbol_get(x) ((typeof(&x))(__symbol_get(VMLINUX_SYMBOL_STR(x))))
 200
 201/* modules using other modules: kdb wants to see this. */
 202struct module_use {
 203        struct list_head source_list;
 204        struct list_head target_list;
 205        struct module *source, *target;
 206};
 207
 208enum module_state {
 209        MODULE_STATE_LIVE,      /* Normal state. */
 210        MODULE_STATE_COMING,    /* Full formed, running module_init. */
 211        MODULE_STATE_GOING,     /* Going away. */
 212        MODULE_STATE_UNFORMED,  /* Still setting it up. */
 213};
 214
 215/**
 216 * struct module_ref - per cpu module reference counts
 217 * @incs: number of module get on this cpu
 218 * @decs: number of module put on this cpu
 219 *
 220 * We force an alignment on 8 or 16 bytes, so that alloc_percpu()
 221 * put @incs/@decs in same cache line, with no extra memory cost,
 222 * since alloc_percpu() is fine grained.
 223 */
 224struct module_ref {
 225        unsigned long incs;
 226        unsigned long decs;
 227} __attribute((aligned(2 * sizeof(unsigned long))));
 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#ifdef CONFIG_MODULE_SIG
 273        /* Signature was verified. */
 274        bool sig_ok;
 275#endif
 276
 277        /* symbols that will be GPL-only in the near future. */
 278        const struct kernel_symbol *gpl_future_syms;
 279        const unsigned long *gpl_future_crcs;
 280        unsigned int num_gpl_future_syms;
 281
 282        /* Exception table */
 283        unsigned int num_exentries;
 284        struct exception_table_entry *extable;
 285
 286        /* Startup function. */
 287        int (*init)(void);
 288
 289        /* If this is non-NULL, vfree after init() returns */
 290        void *module_init;
 291
 292        /* Here is the actual code + data, vfree'd on unload. */
 293        void *module_core;
 294
 295        /* Here are the sizes of the init and core sections */
 296        unsigned int init_size, core_size;
 297
 298        /* The size of the executable code in each section.  */
 299        unsigned int init_text_size, core_text_size;
 300
 301        /* Size of RO sections of the module (text+rodata) */
 302        unsigned int init_ro_size, core_ro_size;
 303
 304        /* Arch-specific module values */
 305        struct mod_arch_specific arch;
 306
 307        unsigned int taints;    /* same bits as kernel:tainted */
 308
 309#ifdef CONFIG_GENERIC_BUG
 310        /* Support for BUG */
 311        unsigned num_bugs;
 312        struct list_head bug_list;
 313        struct bug_entry *bug_table;
 314#endif
 315
 316#ifdef CONFIG_KALLSYMS
 317        /*
 318         * We keep the symbol and string tables for kallsyms.
 319         * The core_* fields below are temporary, loader-only (they
 320         * could really be discarded after module init).
 321         */
 322        Elf_Sym *symtab, *core_symtab;
 323        unsigned int num_symtab, core_num_syms;
 324        char *strtab, *core_strtab;
 325
 326        /* Section attributes */
 327        struct module_sect_attrs *sect_attrs;
 328
 329        /* Notes attributes */
 330        struct module_notes_attrs *notes_attrs;
 331#endif
 332
 333        /* The command line arguments (may be mangled).  People like
 334           keeping pointers to this stuff */
 335        char *args;
 336
 337#ifdef CONFIG_SMP
 338        /* Per-cpu data. */
 339        void __percpu *percpu;
 340        unsigned int percpu_size;
 341#endif
 342
 343#ifdef CONFIG_TRACEPOINTS
 344        unsigned int num_tracepoints;
 345        struct tracepoint * const *tracepoints_ptrs;
 346#endif
 347#ifdef HAVE_JUMP_LABEL
 348        struct jump_entry *jump_entries;
 349        unsigned int num_jump_entries;
 350#endif
 351#ifdef CONFIG_TRACING
 352        unsigned int num_trace_bprintk_fmt;
 353        const char **trace_bprintk_fmt_start;
 354#endif
 355#ifdef CONFIG_EVENT_TRACING
 356        struct ftrace_event_call **trace_events;
 357        unsigned int num_trace_events;
 358#endif
 359#ifdef CONFIG_FTRACE_MCOUNT_RECORD
 360        unsigned int num_ftrace_callsites;
 361        unsigned long *ftrace_callsites;
 362#endif
 363
 364#ifdef CONFIG_MODULE_UNLOAD
 365        /* What modules depend on me? */
 366        struct list_head source_list;
 367        /* What modules do I depend on? */
 368        struct list_head target_list;
 369
 370        /* Who is waiting for us to be unloaded */
 371        struct task_struct *waiter;
 372
 373        /* Destruction function. */
 374        void (*exit)(void);
 375
 376        struct module_ref __percpu *refptr;
 377#endif
 378
 379#ifdef CONFIG_CONSTRUCTORS
 380        /* Constructor functions. */
 381        ctor_fn_t *ctors;
 382        unsigned int num_ctors;
 383#endif
 384};
 385#ifndef MODULE_ARCH_INIT
 386#define MODULE_ARCH_INIT {}
 387#endif
 388
 389extern struct mutex module_mutex;
 390
 391/* FIXME: It'd be nice to isolate modules during init, too, so they
 392   aren't used before they (may) fail.  But presently too much code
 393   (IDE & SCSI) require entry into the module during init.*/
 394static inline int module_is_live(struct module *mod)
 395{
 396        return mod->state != MODULE_STATE_GOING;
 397}
 398
 399struct module *__module_text_address(unsigned long addr);
 400struct module *__module_address(unsigned long addr);
 401bool is_module_address(unsigned long addr);
 402bool is_module_percpu_address(unsigned long addr);
 403bool is_module_text_address(unsigned long addr);
 404
 405static inline int within_module_core(unsigned long addr, const struct module *mod)
 406{
 407        return (unsigned long)mod->module_core <= addr &&
 408               addr < (unsigned long)mod->module_core + mod->core_size;
 409}
 410
 411static inline int within_module_init(unsigned long addr, const struct module *mod)
 412{
 413        return (unsigned long)mod->module_init <= addr &&
 414               addr < (unsigned long)mod->module_init + mod->init_size;
 415}
 416
 417/* Search for module by name: must hold module_mutex. */
 418struct module *find_module(const char *name);
 419
 420struct symsearch {
 421        const struct kernel_symbol *start, *stop;
 422        const unsigned long *crcs;
 423        enum {
 424                NOT_GPL_ONLY,
 425                GPL_ONLY,
 426                WILL_BE_GPL_ONLY,
 427        } licence;
 428        bool unused;
 429};
 430
 431/* Search for an exported symbol by name. */
 432const struct kernel_symbol *find_symbol(const char *name,
 433                                        struct module **owner,
 434                                        const unsigned long **crc,
 435                                        bool gplok,
 436                                        bool warn);
 437
 438/* Walk the exported symbol table */
 439bool each_symbol_section(bool (*fn)(const struct symsearch *arr,
 440                                    struct module *owner,
 441                                    void *data), void *data);
 442
 443/* Returns 0 and fills in value, defined and namebuf, or -ERANGE if
 444   symnum out of range. */
 445int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
 446                        char *name, char *module_name, int *exported);
 447
 448/* Look for this name: can be of form module:name. */
 449unsigned long module_kallsyms_lookup_name(const char *name);
 450
 451int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
 452                                             struct module *, unsigned long),
 453                                   void *data);
 454
 455extern void __module_put_and_exit(struct module *mod, long code)
 456        __attribute__((noreturn));
 457#define module_put_and_exit(code) __module_put_and_exit(THIS_MODULE, code);
 458
 459#ifdef CONFIG_MODULE_UNLOAD
 460unsigned long module_refcount(struct module *mod);
 461void __symbol_put(const char *symbol);
 462#define symbol_put(x) __symbol_put(VMLINUX_SYMBOL_STR(x))
 463void symbol_put_addr(void *addr);
 464
 465/* Sometimes we know we already have a refcount, and it's easier not
 466   to handle the error case (which only happens with rmmod --wait). */
 467extern void __module_get(struct module *module);
 468
 469/* This is the Right Way to get a module: if it fails, it's being removed,
 470 * so pretend it's not there. */
 471extern bool try_module_get(struct module *module);
 472
 473extern void module_put(struct module *module);
 474
 475#else /*!CONFIG_MODULE_UNLOAD*/
 476static inline int try_module_get(struct module *module)
 477{
 478        return !module || module_is_live(module);
 479}
 480static inline void module_put(struct module *module)
 481{
 482}
 483static inline void __module_get(struct module *module)
 484{
 485}
 486#define symbol_put(x) do { } while(0)
 487#define symbol_put_addr(p) do { } while(0)
 488
 489#endif /* CONFIG_MODULE_UNLOAD */
 490int ref_module(struct module *a, struct module *b);
 491
 492/* This is a #define so the string doesn't get put in every .o file */
 493#define module_name(mod)                        \
 494({                                              \
 495        struct module *__mod = (mod);           \
 496        __mod ? __mod->name : "kernel";         \
 497})
 498
 499/* For kallsyms to ask for address resolution.  namebuf should be at
 500 * least KSYM_NAME_LEN long: a pointer to namebuf is returned if
 501 * found, otherwise NULL. */
 502const char *module_address_lookup(unsigned long addr,
 503                            unsigned long *symbolsize,
 504                            unsigned long *offset,
 505                            char **modname,
 506                            char *namebuf);
 507int lookup_module_symbol_name(unsigned long addr, char *symname);
 508int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name);
 509
 510/* For extable.c to search modules' exception tables. */
 511const struct exception_table_entry *search_module_extables(unsigned long addr);
 512
 513int register_module_notifier(struct notifier_block * nb);
 514int unregister_module_notifier(struct notifier_block * nb);
 515
 516extern void print_modules(void);
 517
 518#else /* !CONFIG_MODULES... */
 519
 520/* Given an address, look for it in the exception tables. */
 521static inline const struct exception_table_entry *
 522search_module_extables(unsigned long addr)
 523{
 524        return NULL;
 525}
 526
 527static inline struct module *__module_address(unsigned long addr)
 528{
 529        return NULL;
 530}
 531
 532static inline struct module *__module_text_address(unsigned long addr)
 533{
 534        return NULL;
 535}
 536
 537static inline bool is_module_address(unsigned long addr)
 538{
 539        return false;
 540}
 541
 542static inline bool is_module_percpu_address(unsigned long addr)
 543{
 544        return false;
 545}
 546
 547static inline bool is_module_text_address(unsigned long addr)
 548{
 549        return false;
 550}
 551
 552/* Get/put a kernel symbol (calls should be symmetric) */
 553#define symbol_get(x) ({ extern typeof(x) x __attribute__((weak)); &(x); })
 554#define symbol_put(x) do { } while(0)
 555#define symbol_put_addr(x) do { } while(0)
 556
 557static inline void __module_get(struct module *module)
 558{
 559}
 560
 561static inline int try_module_get(struct module *module)
 562{
 563        return 1;
 564}
 565
 566static inline void module_put(struct module *module)
 567{
 568}
 569
 570#define module_name(mod) "kernel"
 571
 572/* For kallsyms to ask for address resolution.  NULL means not found. */
 573static inline const char *module_address_lookup(unsigned long addr,
 574                                          unsigned long *symbolsize,
 575                                          unsigned long *offset,
 576                                          char **modname,
 577                                          char *namebuf)
 578{
 579        return NULL;
 580}
 581
 582static inline int lookup_module_symbol_name(unsigned long addr, char *symname)
 583{
 584        return -ERANGE;
 585}
 586
 587static inline int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name)
 588{
 589        return -ERANGE;
 590}
 591
 592static inline int module_get_kallsym(unsigned int symnum, unsigned long *value,
 593                                        char *type, char *name,
 594                                        char *module_name, int *exported)
 595{
 596        return -ERANGE;
 597}
 598
 599static inline unsigned long module_kallsyms_lookup_name(const char *name)
 600{
 601        return 0;
 602}
 603
 604static inline int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
 605                                                           struct module *,
 606                                                           unsigned long),
 607                                                 void *data)
 608{
 609        return 0;
 610}
 611
 612static inline int register_module_notifier(struct notifier_block * nb)
 613{
 614        /* no events will happen anyway, so this can always succeed */
 615        return 0;
 616}
 617
 618static inline int unregister_module_notifier(struct notifier_block * nb)
 619{
 620        return 0;
 621}
 622
 623#define module_put_and_exit(code) do_exit(code)
 624
 625static inline void print_modules(void)
 626{
 627}
 628#endif /* CONFIG_MODULES */
 629
 630#ifdef CONFIG_SYSFS
 631extern struct kset *module_kset;
 632extern struct kobj_type module_ktype;
 633extern int module_sysfs_initialized;
 634#endif /* CONFIG_SYSFS */
 635
 636#define symbol_request(x) try_then_request_module(symbol_get(x), "symbol:" #x)
 637
 638/* BELOW HERE ALL THESE ARE OBSOLETE AND WILL VANISH */
 639
 640#define __MODULE_STRING(x) __stringify(x)
 641
 642#ifdef CONFIG_DEBUG_SET_MODULE_RONX
 643extern void set_all_modules_text_rw(void);
 644extern void set_all_modules_text_ro(void);
 645#else
 646static inline void set_all_modules_text_rw(void) { }
 647static inline void set_all_modules_text_ro(void) { }
 648#endif
 649
 650#ifdef CONFIG_GENERIC_BUG
 651void module_bug_finalize(const Elf_Ehdr *, const Elf_Shdr *,
 652                         struct module *);
 653void module_bug_cleanup(struct module *);
 654
 655#else   /* !CONFIG_GENERIC_BUG */
 656
 657static inline void module_bug_finalize(const Elf_Ehdr *hdr,
 658                                        const Elf_Shdr *sechdrs,
 659                                        struct module *mod)
 660{
 661}
 662static inline void module_bug_cleanup(struct module *mod) {}
 663#endif  /* CONFIG_GENERIC_BUG */
 664
 665#endif /* _LINUX_MODULE_H */
 666