include/linux/module.h

   1 #ifndef _LINUX_MODULE_H
   2 #define _LINUX_MODULE_H
   3 /*
   4  * Dynamic loading of modules into the kernel.
   5  *
   6  * Rewritten by Richard Henderson <rth@tamu.edu> Dec 1996
   7  * Rewritten again by Rusty Russell, 2002
   8  */
   9 #include <linux/list.h>
  10 #include <linux/stat.h>
  11 #include <linux/compiler.h>
  12 #include <linux/cache.h>
  13 #include <linux/kmod.h>
  14 #include <linux/elf.h>
  15 #include <linux/stringify.h>
  16 #include <linux/kobject.h>
  17 #include <linux/moduleparam.h>
  18 #include <linux/marker.h>
  19 #include <linux/tracepoint.h>
  20 #include <asm/local.h>
  21
  22 #include <asm/module.h>
  23
  24 /* Not Yet Implemented */
  25 #define MODULE_SUPPORTED_DEVICE(name)
  26
  27 /* some toolchains uses a `_' prefix for all user symbols */
  28 #ifndef MODULE_SYMBOL_PREFIX
  29 #define MODULE_SYMBOL_PREFIX ""
  30 #endif
  31
  32 #define MODULE_NAME_LEN MAX_PARAM_PREFIX_LEN
  33
  34 struct kernel_symbol
  35 {
  36         unsigned long value;
  37         const char *name;
  38 };
  39
  40 struct modversion_info
  41 {
  42         unsigned long crc;
  43         char name[MODULE_NAME_LEN];
  44 };
  45
  46 struct module;
  47
  48 struct module_attribute {
  49         struct attribute attr;
  50         ssize_t (*show)(struct module_attribute *, struct module *, char *);
  51         ssize_t (*store)(struct module_attribute *, struct module *,
  52                          const char *, size_t count);
  53         void (*setup)(struct module *, const char *);
  54         int (*test)(struct module *);
  55         void (*free)(struct module *);
  56 };
  57
  58 struct module_kobject
  59 {
  60         struct kobject kobj;
  61         struct module *mod;
  62         struct kobject *drivers_dir;
  63         struct module_param_attrs *mp;
  64 };
  65
  66 /* These are either module local, or the kernel's dummy ones. */
  67 extern int init_module(void);
  68 extern void cleanup_module(void);
  69
  70 /* Archs provide a method of finding the correct exception table. */
  71 struct exception_table_entry;
  72
  73 const struct exception_table_entry *
  74 search_extable(const struct exception_table_entry *first,
  75                const struct exception_table_entry *last,
  76                unsigned long value);
  77 void sort_extable(struct exception_table_entry *start,
  78                   struct exception_table_entry *finish);
  79 void sort_main_extable(void);
  80
  81 /*
  82  * Return a pointer to the current module, but only if within a module
  83  */
  84 #ifdef MODULE
  85 extern struct module __this_module;
  86 #define THIS_MODULE (&__this_module)
  87 #else  /* !MODULE */
  88 #define THIS_MODULE ((struct module *)0)
  89 #endif
  90
  91 /*
  92  * Declare a module table
  93  * - this suppresses "'name' defined but not used" warnings from the compiler
  94  *   as the table may not actually be used by the code within the module
  95  */
  96 #ifdef MODULE
  97 #define MODULE_GENERIC_TABLE(gtype,name)                        \
  98 extern const struct gtype##_id __mod_##gtype##_table            \
  99   __attribute__ ((unused, alias(__stringify(name))))
 100 #define MODULE_STATIC_GENERIC_TABLE(gtype,name)                 \
 101 extern const struct gtype##_id __mod_##gtype##_table            \
 102   __attribute__ ((unused, alias(__stringify(name))))
 103 #else
 104 #define MODULE_GENERIC_TABLE(gtype,name)
 105 #define MODULE_STATIC_GENERIC_TABLE(gtype,name) \
 106 static __typeof__((name)) name __attribute__((unused));
 107 #endif
 108
 109 /* Generic info of form tag = "info" */
 110 #define MODULE_INFO(tag, info) __MODULE_INFO(tag, tag, info)
 111
 112 /* For userspace: you can also call me... */
 113 #define MODULE_ALIAS(_alias) MODULE_INFO(alias, _alias)
 114
 115 /*
 116  * The following license idents are currently accepted as indicating free
 117  * software modules
 118  *
 119  *      "GPL"                           [GNU Public License v2 or later]
 120  *      "GPL v2"                        [GNU Public License v2]
 121  *      "GPL and additional rights"     [GNU Public License v2 rights and more]
 122  *      "Dual BSD/GPL"                  [GNU Public License v2
 123  *                                       or BSD license choice]
 124  *      "Dual MIT/GPL"                  [GNU Public License v2
 125  *                                       or MIT license choice]
 126  *      "Dual MPL/GPL"                  [GNU Public License v2
 127  *                                       or Mozilla license choice]
 128  *
 129  * The following other idents are available
 130  *
 131  *      "Proprietary"                   [Non free products]
 132  *
 133  * There are dual licensed components, but when running with Linux it is the
 134  * GPL that is relevant so this is a non issue. Similarly LGPL linked with GPL
 135  * is a GPL combined work.
 136  *
 137  * This exists for several reasons
 138  * 1.   So modinfo can show license info for users wanting to vet their setup
 139  *      is free
 140  * 2.   So the community can ignore bug reports including proprietary modules
 141  * 3.   So vendors can do likewise based on their own policies
 142  */
 143 #define MODULE_LICENSE(_license) MODULE_INFO(license, _license)
 144
 145 /* Author, ideally of form NAME[, NAME]*[ and NAME] */
 146 #define MODULE_AUTHOR(_author) MODULE_INFO(author, _author)
 147
 148 /* What your module does. */
 149 #define MODULE_DESCRIPTION(_description) MODULE_INFO(description, _description)
 150
 151 /* One for each parameter, describing how to use it.  Some files do
 152    multiple of these per line, so can't just use MODULE_INFO. */
 153 #define MODULE_PARM_DESC(_parm, desc) \
 154         __MODULE_INFO(parm, _parm, #_parm ":" desc)
 155
 156 #define MODULE_DEVICE_TABLE(type,name)          \
 157   MODULE_GENERIC_TABLE(type##_device,name)
 158 #define MODULE_STATIC_DEVICE_TABLE(type,name)           \
 159   MODULE_STATIC_GENERIC_TABLE(type##_device,name)
 160
 161 /* Version of form [<epoch>:]<version>[-<extra-version>].
 162    Or for CVS/RCS ID version, everything but the number is stripped.
 163   <epoch>: A (small) unsigned integer which allows you to start versions
 164            anew. If not mentioned, it's zero.  eg. "2:1.0" is after
 165            "1:2.0".
 166   <version>: The <version> may contain only alphanumerics and the
 167            character `.'.  Ordered by numeric sort for numeric parts,
 168            ascii sort for ascii parts (as per RPM or DEB algorithm).
 169   <extraversion>: Like <version>, but inserted for local
 170            customizations, eg "rh3" or "rusty1".
 171
 172   Using this automatically adds a checksum of the .c files and the
 173   local headers in "srcversion".
 174 */
 175 #define MODULE_VERSION(_version) MODULE_INFO(version, _version)
 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 */
 183 const struct exception_table_entry *search_exception_tables(unsigned long add);
 184
 185 struct notifier_block;
 186
 187 #ifdef CONFIG_MODULES
 188
 189 /* Get/put a kernel symbol (calls must be symmetric) */
 190 void *__symbol_get(const char *symbol);
 191 void *__symbol_get_gpl(const char *symbol);
 192 #define symbol_get(x) ((typeof(&x))(__symbol_get(MODULE_SYMBOL_PREFIX #x)))
 193
 194 #ifndef __GENKSYMS__
 195 #ifdef CONFIG_MODVERSIONS
 196 /* Mark the CRC weak since genksyms apparently decides not to
 197  * generate a checksums for some symbols */
 198 #define __CRC_SYMBOL(sym, sec)                                  \
 199         extern void *__crc_##sym __attribute__((weak));         \
 200         static const unsigned long __kcrctab_##sym              \
 201         __used                                                  \
 202         __attribute__((section("__kcrctab" sec), unused))       \
 203         = (unsigned long) &__crc_##sym;
 204 #else
 205 #define __CRC_SYMBOL(sym, sec)
 206 #endif
 207
 208 /* For every exported symbol, place a struct in the __ksymtab section */
 209 #define __EXPORT_SYMBOL(sym, sec)                               \
 210         extern typeof(sym) sym;                                 \
 211         __CRC_SYMBOL(sym, sec)                                  \
 212         static const char __kstrtab_##sym[]                     \
 213         __attribute__((section("__ksymtab_strings"), aligned(1))) \
 214         = MODULE_SYMBOL_PREFIX #sym;                            \
 215         static const struct kernel_symbol __ksymtab_##sym       \
 216         __used                                                  \
 217         __attribute__((section("__ksymtab" sec), unused))       \
 218         = { (unsigned long)&sym, __kstrtab_##sym }
 219
 220 #define EXPORT_SYMBOL(sym)                                      \
 221         __EXPORT_SYMBOL(sym, "")
 222
 223 #define EXPORT_SYMBOL_GPL(sym)                                  \
 224         __EXPORT_SYMBOL(sym, "_gpl")
 225
 226 #define EXPORT_SYMBOL_GPL_FUTURE(sym)                           \
 227         __EXPORT_SYMBOL(sym, "_gpl_future")
 228
 229
 230 #ifdef CONFIG_UNUSED_SYMBOLS
 231 #define EXPORT_UNUSED_SYMBOL(sym) __EXPORT_SYMBOL(sym, "_unused")
 232 #define EXPORT_UNUSED_SYMBOL_GPL(sym) __EXPORT_SYMBOL(sym, "_unused_gpl")
 233 #else
 234 #define EXPORT_UNUSED_SYMBOL(sym)
 235 #define EXPORT_UNUSED_SYMBOL_GPL(sym)
 236 #endif
 237
 238 #endif
 239
 240 enum module_state
 241 {
 242         MODULE_STATE_LIVE,
 243         MODULE_STATE_COMING,
 244         MODULE_STATE_GOING,
 245 };
 246
 247 struct module
 248 {
 249         enum module_state state;
 250
 251         /* Member of list of modules */
 252         struct list_head list;
 253
 254         /* Unique handle for this module */
 255         char name[MODULE_NAME_LEN];
 256
 257         /* Sysfs stuff. */
 258         struct module_kobject mkobj;
 259         struct module_attribute *modinfo_attrs;
 260         const char *version;
 261         const char *srcversion;
 262         struct kobject *holders_dir;
 263
 264         /* Exported symbols */
 265         const struct kernel_symbol *syms;
 266         const unsigned long *crcs;
 267         unsigned int num_syms;
 268
 269         /* GPL-only exported symbols. */
 270         unsigned int num_gpl_syms;
 271         const struct kernel_symbol *gpl_syms;
 272         const unsigned long *gpl_crcs;
 273
 274 #ifdef CONFIG_UNUSED_SYMBOLS
 275         /* unused exported symbols. */
 276         const struct kernel_symbol *unused_syms;
 277         const unsigned long *unused_crcs;
 278         unsigned int num_unused_syms;
 279
 280         /* GPL-only, unused exported symbols. */
 281         unsigned int num_unused_gpl_syms;
 282         const struct kernel_symbol *unused_gpl_syms;
 283         const unsigned long *unused_gpl_crcs;
 284 #endif
 285
 286         /* symbols that will be GPL-only in the near future. */
 287         const struct kernel_symbol *gpl_future_syms;
 288         const unsigned long *gpl_future_crcs;
 289         unsigned int num_gpl_future_syms;
 290
 291         /* Exception table */
 292         unsigned int num_exentries;
 293         struct exception_table_entry *extable;
 294
 295         /* Startup function. */
 296         int (*init)(void);
 297
 298         /* If this is non-NULL, vfree after init() returns */
 299         void *module_init;
 300
 301         /* Here is the actual code + data, vfree'd on unload. */
 302         void *module_core;
 303
 304         /* Here are the sizes of the init and core sections */
 305         unsigned int init_size, core_size;
 306
 307         /* The size of the executable code in each section.  */
 308         unsigned int init_text_size, core_text_size;
 309
 310         /* Arch-specific module values */
 311         struct mod_arch_specific arch;
 312
 313         unsigned int taints;    /* same bits as kernel:tainted */
 314
 315 #ifdef CONFIG_GENERIC_BUG
 316         /* Support for BUG */
 317         unsigned num_bugs;
 318         struct list_head bug_list;
 319         struct bug_entry *bug_table;
 320 #endif
 321
 322 #ifdef CONFIG_KALLSYMS
 323         /* We keep the symbol and string tables for kallsyms. */
 324         Elf_Sym *symtab;
 325         unsigned int num_symtab;
 326         char *strtab;
 327
 328         /* Section attributes */
 329         struct module_sect_attrs *sect_attrs;
 330
 331         /* Notes attributes */
 332         struct module_notes_attrs *notes_attrs;
 333 #endif
 334
 335         /* Per-cpu data. */
 336         void *percpu;
 337
 338         /* The command line arguments (may be mangled).  People like
 339            keeping pointers to this stuff */
 340         char *args;
 341 #ifdef CONFIG_MARKERS
 342         struct marker *markers;
 343         unsigned int num_markers;
 344 #endif
 345 #ifdef CONFIG_TRACEPOINTS
 346         struct tracepoint *tracepoints;
 347         unsigned int num_tracepoints;
 348 #endif
 349
 350 #ifdef CONFIG_TRACING
 351         const char **trace_bprintk_fmt_start;
 352         unsigned int num_trace_bprintk_fmt;
 353 #endif
 354
 355 #ifdef CONFIG_MODULE_UNLOAD
 356         /* What modules depend on me? */
 357         struct list_head modules_which_use_me;
 358
 359         /* Who is waiting for us to be unloaded */
 360         struct task_struct *waiter;
 361
 362         /* Destruction function. */
 363         void (*exit)(void);
 364
 365 #ifdef CONFIG_SMP
 366         char *refptr;
 367 #else
 368         local_t ref;
 369 #endif
 370 #endif
 371 };
 372 #ifndef MODULE_ARCH_INIT
 373 #define MODULE_ARCH_INIT {}
 374 #endif
 375
 376 /* FIXME: It'd be nice to isolate modules during init, too, so they
 377    aren't used before they (may) fail.  But presently too much code
 378    (IDE & SCSI) require entry into the module during init.*/
 379 static inline int module_is_live(struct module *mod)
 380 {
 381         return mod->state != MODULE_STATE_GOING;
 382 }
 383
 384 /* Is this address in a module? (second is with no locks, for oops) */
 385 struct module *module_text_address(unsigned long addr);
 386 struct module *__module_text_address(unsigned long addr);
 387 int is_module_address(unsigned long addr);
 388
 389 static inline int within_module_core(unsigned long addr, struct module *mod)
 390 {
 391         return (unsigned long)mod->module_core <= addr &&
 392                addr < (unsigned long)mod->module_core + mod->core_size;
 393 }
 394
 395 static inline int within_module_init(unsigned long addr, struct module *mod)
 396 {
 397         return (unsigned long)mod->module_init <= addr &&
 398                addr < (unsigned long)mod->module_init + mod->init_size;
 399 }
 400
 401 /* Returns 0 and fills in value, defined and namebuf, or -ERANGE if
 402    symnum out of range. */
 403 int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
 404                         char *name, char *module_name, int *exported);
 405
 406 /* Look for this name: can be of form module:name. */
 407 unsigned long module_kallsyms_lookup_name(const char *name);
 408
 409 extern void __module_put_and_exit(struct module *mod, long code)
 410         __attribute__((noreturn));
 411 #define module_put_and_exit(code) __module_put_and_exit(THIS_MODULE, code);
 412
 413 #ifdef CONFIG_MODULE_UNLOAD
 414 unsigned int module_refcount(struct module *mod);
 415 void __symbol_put(const char *symbol);
 416 #define symbol_put(x) __symbol_put(MODULE_SYMBOL_PREFIX #x)
 417 void symbol_put_addr(void *addr);
 418
 419 static inline local_t *__module_ref_addr(struct module *mod, int cpu)
 420 {
 421 #ifdef CONFIG_SMP
 422         return (local_t *) (mod->refptr + per_cpu_offset(cpu));
 423 #else
 424         return &mod->ref;
 425 #endif
 426 }
 427
 428 /* Sometimes we know we already have a refcount, and it's easier not
 429    to handle the error case (which only happens with rmmod --wait). */
 430 static inline void __module_get(struct module *module)
 431 {
 432         if (module) {
 433                 local_inc(__module_ref_addr(module, get_cpu()));
 434                 put_cpu();
 435         }
 436 }
 437
 438 static inline int try_module_get(struct module *module)
 439 {
 440         int ret = 1;
 441
 442         if (module) {
 443                 unsigned int cpu = get_cpu();
 444                 if (likely(module_is_live(module)))
 445                         local_inc(__module_ref_addr(module, cpu));
 446                 else
 447                         ret = 0;
 448                 put_cpu();
 449         }
 450         return ret;
 451 }
 452
 453 extern void module_put(struct module *module);
 454
 455 #else /*!CONFIG_MODULE_UNLOAD*/
 456 static inline int try_module_get(struct module *module)
 457 {
 458         return !module || module_is_live(module);
 459 }
 460 static inline void module_put(struct module *module)
 461 {
 462 }
 463 static inline void __module_get(struct module *module)
 464 {
 465 }
 466 #define symbol_put(x) do { } while(0)
 467 #define symbol_put_addr(p) do { } while(0)
 468
 469 #endif /* CONFIG_MODULE_UNLOAD */
 470
 471 /* This is a #define so the string doesn't get put in every .o file */
 472 #define module_name(mod)                        \
 473 ({                                              \
 474         struct module *__mod = (mod);           \
 475         __mod ? __mod->name : "kernel";         \
 476 })
 477
 478 /* For kallsyms to ask for address resolution.  namebuf should be at
 479  * least KSYM_NAME_LEN long: a pointer to namebuf is returned if
 480  * found, otherwise NULL. */
 481 const char *module_address_lookup(unsigned long addr,
 482                             unsigned long *symbolsize,
 483                             unsigned long *offset,
 484                             char **modname,
 485                             char *namebuf);
 486 int lookup_module_symbol_name(unsigned long addr, char *symname);
 487 int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name);
 488
 489 /* For extable.c to search modules' exception tables. */
 490 const struct exception_table_entry *search_module_extables(unsigned long addr);
 491
 492 int register_module_notifier(struct notifier_block * nb);
 493 int unregister_module_notifier(struct notifier_block * nb);
 494
 495 extern void print_modules(void);
 496
 497 extern void module_update_markers(void);
 498
 499 extern void module_update_tracepoints(void);
 500 extern int module_get_iter_tracepoints(struct tracepoint_iter *iter);
 501
 502 #else /* !CONFIG_MODULES... */
 503 #define EXPORT_SYMBOL(sym)
 504 #define EXPORT_SYMBOL_GPL(sym)
 505 #define EXPORT_SYMBOL_GPL_FUTURE(sym)
 506 #define EXPORT_UNUSED_SYMBOL(sym)
 507 #define EXPORT_UNUSED_SYMBOL_GPL(sym)
 508
 509 /* Given an address, look for it in the exception tables. */
 510 static inline const struct exception_table_entry *
 511 search_module_extables(unsigned long addr)
 512 {
 513         return NULL;
 514 }
 515
 516 /* Is this address in a module? */
 517 static inline struct module *module_text_address(unsigned long addr)
 518 {
 519         return NULL;
 520 }
 521
 522 /* Is this address in a module? (don't take a lock, we're oopsing) */
 523 static inline struct module *__module_text_address(unsigned long addr)
 524 {
 525         return NULL;
 526 }
 527
 528 static inline int is_module_address(unsigned long addr)
 529 {
 530         return 0;
 531 }
 532
 533 /* Get/put a kernel symbol (calls should be symmetric) */
 534 #define symbol_get(x) ({ extern typeof(x) x __attribute__((weak)); &(x); })
 535 #define symbol_put(x) do { } while(0)
 536 #define symbol_put_addr(x) do { } while(0)
 537
 538 static inline void __module_get(struct module *module)
 539 {
 540 }
 541
 542 static inline int try_module_get(struct module *module)
 543 {
 544         return 1;
 545 }
 546
 547 static inline void module_put(struct module *module)
 548 {
 549 }
 550
 551 #define module_name(mod) "kernel"
 552
 553 /* For kallsyms to ask for address resolution.  NULL means not found. */
 554 static inline const char *module_address_lookup(unsigned long addr,
 555                                           unsigned long *symbolsize,
 556                                           unsigned long *offset,
 557                                           char **modname,
 558                                           char *namebuf)
 559 {
 560         return NULL;
 561 }
 562
 563 static inline int lookup_module_symbol_name(unsigned long addr, char *symname)
 564 {
 565         return -ERANGE;
 566 }
 567
 568 static inline int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name)
 569 {
 570         return -ERANGE;
 571 }
 572
 573 static inline int module_get_kallsym(unsigned int symnum, unsigned long *value,
 574                                         char *type, char *name,
 575                                         char *module_name, int *exported)
 576 {
 577         return -ERANGE;
 578 }
 579
 580 static inline unsigned long module_kallsyms_lookup_name(const char *name)
 581 {
 582         return 0;
 583 }
 584
 585 static inline int register_module_notifier(struct notifier_block * nb)
 586 {
 587         /* no events will happen anyway, so this can always succeed */
 588         return 0;
 589 }
 590
 591 static inline int unregister_module_notifier(struct notifier_block * nb)
 592 {
 593         return 0;
 594 }
 595
 596 #define module_put_and_exit(code) do_exit(code)
 597
 598 static inline void print_modules(void)
 599 {
 600 }
 601
 602 static inline void module_update_markers(void)
 603 {
 604 }
 605
 606 static inline void module_update_tracepoints(void)
 607 {
 608 }
 609
 610 static inline int module_get_iter_tracepoints(struct tracepoint_iter *iter)
 611 {
 612         return 0;
 613 }
 614
 615 #endif /* CONFIG_MODULES */
 616
 617 struct device_driver;
 618 #ifdef CONFIG_SYSFS
 619 struct module;
 620
 621 extern struct kset *module_kset;
 622 extern struct kobj_type module_ktype;
 623 extern int module_sysfs_initialized;
 624
 625 int mod_sysfs_init(struct module *mod);
 626 int mod_sysfs_setup(struct module *mod,
 627                            struct kernel_param *kparam,
 628                            unsigned int num_params);
 629 int module_add_modinfo_attrs(struct module *mod);
 630 void module_remove_modinfo_attrs(struct module *mod);
 631
 632 #else /* !CONFIG_SYSFS */
 633
 634 static inline int mod_sysfs_init(struct module *mod)
 635 {
 636         return 0;
 637 }
 638
 639 static inline int mod_sysfs_setup(struct module *mod,
 640                            struct kernel_param *kparam,
 641                            unsigned int num_params)
 642 {
 643         return 0;
 644 }
 645
 646 static inline int module_add_modinfo_attrs(struct module *mod)
 647 {
 648         return 0;
 649 }
 650
 651 static inline void module_remove_modinfo_attrs(struct module *mod)
 652 { }
 653
 654 #endif /* CONFIG_SYSFS */
 655
 656 #define symbol_request(x) try_then_request_module(symbol_get(x), "symbol:" #x)
 657
 658 /* BELOW HERE ALL THESE ARE OBSOLETE AND WILL VANISH */
 659
 660 #define __MODULE_STRING(x) __stringify(x)
 661
 662 #endif /* _LINUX_MODULE_H */