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 #ifdef MODULE
  82 #define MODULE_GENERIC_TABLE(gtype,name)                        \
  83 extern const struct gtype##_id __mod_##gtype##_table            \
  84   __attribute__ ((unused, alias(__stringify(name))))
  85
  86 extern struct module __this_module;
  87 #define THIS_MODULE (&__this_module)
  88 #else  /* !MODULE */
  89 #define MODULE_GENERIC_TABLE(gtype,name)
  90 #define THIS_MODULE ((struct module *)0)
  91 #endif
  92
  93 /* Generic info of form tag = "info" */
  94 #define MODULE_INFO(tag, info) __MODULE_INFO(tag, tag, info)
  95
  96 /* For userspace: you can also call me... */
  97 #define MODULE_ALIAS(_alias) MODULE_INFO(alias, _alias)
  98
  99 /*
 100  * The following license idents are currently accepted as indicating free
 101  * software modules
 102  *
 103  *      "GPL"                           [GNU Public License v2 or later]
 104  *      "GPL v2"                        [GNU Public License v2]
 105  *      "GPL and additional rights"     [GNU Public License v2 rights and more]
 106  *      "Dual BSD/GPL"                  [GNU Public License v2
 107  *                                       or BSD license choice]
 108  *      "Dual MIT/GPL"                  [GNU Public License v2
 109  *                                       or MIT license choice]
 110  *      "Dual MPL/GPL"                  [GNU Public License v2
 111  *                                       or Mozilla license choice]
 112  *
 113  * The following other idents are available
 114  *
 115  *      "Proprietary"                   [Non free products]
 116  *
 117  * There are dual licensed components, but when running with Linux it is the
 118  * GPL that is relevant so this is a non issue. Similarly LGPL linked with GPL
 119  * is a GPL combined work.
 120  *
 121  * This exists for several reasons
 122  * 1.   So modinfo can show license info for users wanting to vet their setup
 123  *      is free
 124  * 2.   So the community can ignore bug reports including proprietary modules
 125  * 3.   So vendors can do likewise based on their own policies
 126  */
 127 #define MODULE_LICENSE(_license) MODULE_INFO(license, _license)
 128
 129 /* Author, ideally of form NAME[, NAME]*[ and NAME] */
 130 #define MODULE_AUTHOR(_author) MODULE_INFO(author, _author)
 131
 132 /* What your module does. */
 133 #define MODULE_DESCRIPTION(_description) MODULE_INFO(description, _description)
 134
 135 /* One for each parameter, describing how to use it.  Some files do
 136    multiple of these per line, so can't just use MODULE_INFO. */
 137 #define MODULE_PARM_DESC(_parm, desc) \
 138         __MODULE_INFO(parm, _parm, #_parm ":" desc)
 139
 140 #define MODULE_DEVICE_TABLE(type,name)          \
 141   MODULE_GENERIC_TABLE(type##_device,name)
 142
 143 /* Version of form [<epoch>:]<version>[-<extra-version>].
 144    Or for CVS/RCS ID version, everything but the number is stripped.
 145   <epoch>: A (small) unsigned integer which allows you to start versions
 146            anew. If not mentioned, it's zero.  eg. "2:1.0" is after
 147            "1:2.0".
 148   <version>: The <version> may contain only alphanumerics and the
 149            character `.'.  Ordered by numeric sort for numeric parts,
 150            ascii sort for ascii parts (as per RPM or DEB algorithm).
 151   <extraversion>: Like <version>, but inserted for local
 152            customizations, eg "rh3" or "rusty1".
 153
 154   Using this automatically adds a checksum of the .c files and the
 155   local headers in "srcversion".
 156 */
 157 #define MODULE_VERSION(_version) MODULE_INFO(version, _version)
 158
 159 /* Optional firmware file (or files) needed by the module
 160  * format is simply firmware file name.  Multiple firmware
 161  * files require multiple MODULE_FIRMWARE() specifiers */
 162 #define MODULE_FIRMWARE(_firmware) MODULE_INFO(firmware, _firmware)
 163
 164 /* Given an address, look for it in the exception tables */
 165 const struct exception_table_entry *search_exception_tables(unsigned long add);
 166
 167 struct notifier_block;
 168
 169 #ifdef CONFIG_MODULES
 170
 171 /* Get/put a kernel symbol (calls must be symmetric) */
 172 void *__symbol_get(const char *symbol);
 173 void *__symbol_get_gpl(const char *symbol);
 174 #define symbol_get(x) ((typeof(&x))(__symbol_get(MODULE_SYMBOL_PREFIX #x)))
 175
 176 #ifndef __GENKSYMS__
 177 #ifdef CONFIG_MODVERSIONS
 178 /* Mark the CRC weak since genksyms apparently decides not to
 179  * generate a checksums for some symbols */
 180 #define __CRC_SYMBOL(sym, sec)                                  \
 181         extern void *__crc_##sym __attribute__((weak));         \
 182         static const unsigned long __kcrctab_##sym              \
 183         __used                                                  \
 184         __attribute__((section("__kcrctab" sec), unused))       \
 185         = (unsigned long) &__crc_##sym;
 186 #else
 187 #define __CRC_SYMBOL(sym, sec)
 188 #endif
 189
 190 /* For every exported symbol, place a struct in the __ksymtab section */
 191 #define __EXPORT_SYMBOL(sym, sec)                               \
 192         extern typeof(sym) sym;                                 \
 193         __CRC_SYMBOL(sym, sec)                                  \
 194         static const char __kstrtab_##sym[]                     \
 195         __attribute__((section("__ksymtab_strings"), aligned(1))) \
 196         = MODULE_SYMBOL_PREFIX #sym;                            \
 197         static const struct kernel_symbol __ksymtab_##sym       \
 198         __used                                                  \
 199         __attribute__((section("__ksymtab" sec), unused))       \
 200         = { (unsigned long)&sym, __kstrtab_##sym }
 201
 202 #define EXPORT_SYMBOL(sym)                                      \
 203         __EXPORT_SYMBOL(sym, "")
 204
 205 #define EXPORT_SYMBOL_GPL(sym)                                  \
 206         __EXPORT_SYMBOL(sym, "_gpl")
 207
 208 #define EXPORT_SYMBOL_GPL_FUTURE(sym)                           \
 209         __EXPORT_SYMBOL(sym, "_gpl_future")
 210
 211
 212 #ifdef CONFIG_UNUSED_SYMBOLS
 213 #define EXPORT_UNUSED_SYMBOL(sym) __EXPORT_SYMBOL(sym, "_unused")
 214 #define EXPORT_UNUSED_SYMBOL_GPL(sym) __EXPORT_SYMBOL(sym, "_unused_gpl")
 215 #else
 216 #define EXPORT_UNUSED_SYMBOL(sym)
 217 #define EXPORT_UNUSED_SYMBOL_GPL(sym)
 218 #endif
 219
 220 #endif
 221
 222 enum module_state
 223 {
 224         MODULE_STATE_LIVE,
 225         MODULE_STATE_COMING,
 226         MODULE_STATE_GOING,
 227 };
 228
 229 struct 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         /* symbols that will be GPL-only in the near future. */
 273         const struct kernel_symbol *gpl_future_syms;
 274         const unsigned long *gpl_future_crcs;
 275         unsigned int num_gpl_future_syms;
 276
 277         /* Exception table */
 278         unsigned int num_exentries;
 279         struct exception_table_entry *extable;
 280
 281         /* Startup function. */
 282         int (*init)(void);
 283
 284         /* If this is non-NULL, vfree after init() returns */
 285         void *module_init;
 286
 287         /* Here is the actual code + data, vfree'd on unload. */
 288         void *module_core;
 289
 290         /* Here are the sizes of the init and core sections */
 291         unsigned int init_size, core_size;
 292
 293         /* The size of the executable code in each section.  */
 294         unsigned int init_text_size, core_text_size;
 295
 296         /* Arch-specific module values */
 297         struct mod_arch_specific arch;
 298
 299         unsigned int taints;    /* same bits as kernel:tainted */
 300
 301 #ifdef CONFIG_GENERIC_BUG
 302         /* Support for BUG */
 303         unsigned num_bugs;
 304         struct list_head bug_list;
 305         struct bug_entry *bug_table;
 306 #endif
 307
 308 #ifdef CONFIG_KALLSYMS
 309         /* We keep the symbol and string tables for kallsyms. */
 310         Elf_Sym *symtab;
 311         unsigned int num_symtab;
 312         char *strtab;
 313
 314         /* Section attributes */
 315         struct module_sect_attrs *sect_attrs;
 316
 317         /* Notes attributes */
 318         struct module_notes_attrs *notes_attrs;
 319 #endif
 320
 321         /* Per-cpu data. */
 322         void *percpu;
 323
 324         /* The command line arguments (may be mangled).  People like
 325            keeping pointers to this stuff */
 326         char *args;
 327 #ifdef CONFIG_MARKERS
 328         struct marker *markers;
 329         unsigned int num_markers;
 330 #endif
 331 #ifdef CONFIG_TRACEPOINTS
 332         struct tracepoint *tracepoints;
 333         unsigned int num_tracepoints;
 334 #endif
 335
 336 #ifdef CONFIG_TRACING
 337         const char **trace_bprintk_fmt_start;
 338         unsigned int num_trace_bprintk_fmt;
 339 #endif
 340
 341 #ifdef CONFIG_MODULE_UNLOAD
 342         /* What modules depend on me? */
 343         struct list_head modules_which_use_me;
 344
 345         /* Who is waiting for us to be unloaded */
 346         struct task_struct *waiter;
 347
 348         /* Destruction function. */
 349         void (*exit)(void);
 350
 351 #ifdef CONFIG_SMP
 352         char *refptr;
 353 #else
 354         local_t ref;
 355 #endif
 356 #endif
 357 };
 358 #ifndef MODULE_ARCH_INIT
 359 #define MODULE_ARCH_INIT {}
 360 #endif
 361
 362 extern struct mutex module_mutex;
 363
 364 /* FIXME: It'd be nice to isolate modules during init, too, so they
 365    aren't used before they (may) fail.  But presently too much code
 366    (IDE & SCSI) require entry into the module during init.*/
 367 static inline int module_is_live(struct module *mod)
 368 {
 369         return mod->state != MODULE_STATE_GOING;
 370 }
 371
 372 struct module *__module_text_address(unsigned long addr);
 373 struct module *__module_address(unsigned long addr);
 374 bool is_module_address(unsigned long addr);
 375 bool is_module_text_address(unsigned long addr);
 376
 377 static inline int within_module_core(unsigned long addr, struct module *mod)
 378 {
 379         return (unsigned long)mod->module_core <= addr &&
 380                addr < (unsigned long)mod->module_core + mod->core_size;
 381 }
 382
 383 static inline int within_module_init(unsigned long addr, struct module *mod)
 384 {
 385         return (unsigned long)mod->module_init <= addr &&
 386                addr < (unsigned long)mod->module_init + mod->init_size;
 387 }
 388
 389 /* Search for module by name: must hold module_mutex. */
 390 struct module *find_module(const char *name);
 391
 392 struct symsearch {
 393         const struct kernel_symbol *start, *stop;
 394         const unsigned long *crcs;
 395         enum {
 396                 NOT_GPL_ONLY,
 397                 GPL_ONLY,
 398                 WILL_BE_GPL_ONLY,
 399         } licence;
 400         bool unused;
 401 };
 402
 403 /* Search for an exported symbol by name. */
 404 const struct kernel_symbol *find_symbol(const char *name,
 405                                         struct module **owner,
 406                                         const unsigned long **crc,
 407                                         bool gplok,
 408                                         bool warn);
 409
 410 /* Walk the exported symbol table */
 411 bool each_symbol(bool (*fn)(const struct symsearch *arr, struct module *owner,
 412                             unsigned int symnum, void *data), void *data);
 413
 414 /* Returns 0 and fills in value, defined and namebuf, or -ERANGE if
 415    symnum out of range. */
 416 int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
 417                         char *name, char *module_name, int *exported);
 418
 419 /* Look for this name: can be of form module:name. */
 420 unsigned long module_kallsyms_lookup_name(const char *name);
 421
 422 int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
 423                                              struct module *, unsigned long),
 424                                    void *data);
 425
 426 extern void __module_put_and_exit(struct module *mod, long code)
 427         __attribute__((noreturn));
 428 #define module_put_and_exit(code) __module_put_and_exit(THIS_MODULE, code);
 429
 430 #ifdef CONFIG_MODULE_UNLOAD
 431 unsigned int module_refcount(struct module *mod);
 432 void __symbol_put(const char *symbol);
 433 #define symbol_put(x) __symbol_put(MODULE_SYMBOL_PREFIX #x)
 434 void symbol_put_addr(void *addr);
 435
 436 static inline local_t *__module_ref_addr(struct module *mod, int cpu)
 437 {
 438 #ifdef CONFIG_SMP
 439         return (local_t *) (mod->refptr + per_cpu_offset(cpu));
 440 #else
 441         return &mod->ref;
 442 #endif
 443 }
 444
 445 /* Sometimes we know we already have a refcount, and it's easier not
 446    to handle the error case (which only happens with rmmod --wait). */
 447 static inline void __module_get(struct module *module)
 448 {
 449         if (module) {
 450                 local_inc(__module_ref_addr(module, get_cpu()));
 451                 put_cpu();
 452         }
 453 }
 454
 455 static inline int try_module_get(struct module *module)
 456 {
 457         int ret = 1;
 458
 459         if (module) {
 460                 unsigned int cpu = get_cpu();
 461                 if (likely(module_is_live(module)))
 462                         local_inc(__module_ref_addr(module, cpu));
 463                 else
 464                         ret = 0;
 465                 put_cpu();
 466         }
 467         return ret;
 468 }
 469
 470 extern void module_put(struct module *module);
 471
 472 #else /*!CONFIG_MODULE_UNLOAD*/
 473 static inline int try_module_get(struct module *module)
 474 {
 475         return !module || module_is_live(module);
 476 }
 477 static inline void module_put(struct module *module)
 478 {
 479 }
 480 static inline void __module_get(struct module *module)
 481 {
 482 }
 483 #define symbol_put(x) do { } while(0)
 484 #define symbol_put_addr(p) do { } while(0)
 485
 486 #endif /* CONFIG_MODULE_UNLOAD */
 487 int use_module(struct module *a, struct module *b);
 488
 489 /* This is a #define so the string doesn't get put in every .o file */
 490 #define module_name(mod)                        \
 491 ({                                              \
 492         struct module *__mod = (mod);           \
 493         __mod ? __mod->name : "kernel";         \
 494 })
 495
 496 /* For kallsyms to ask for address resolution.  namebuf should be at
 497  * least KSYM_NAME_LEN long: a pointer to namebuf is returned if
 498  * found, otherwise NULL. */
 499 const char *module_address_lookup(unsigned long addr,
 500                             unsigned long *symbolsize,
 501                             unsigned long *offset,
 502                             char **modname,
 503                             char *namebuf);
 504 int lookup_module_symbol_name(unsigned long addr, char *symname);
 505 int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name);
 506
 507 /* For extable.c to search modules' exception tables. */
 508 const struct exception_table_entry *search_module_extables(unsigned long addr);
 509
 510 int register_module_notifier(struct notifier_block * nb);
 511 int unregister_module_notifier(struct notifier_block * nb);
 512
 513 extern void print_modules(void);
 514
 515 extern void module_update_markers(void);
 516
 517 extern void module_update_tracepoints(void);
 518 extern int module_get_iter_tracepoints(struct tracepoint_iter *iter);
 519
 520 #else /* !CONFIG_MODULES... */
 521 #define EXPORT_SYMBOL(sym)
 522 #define EXPORT_SYMBOL_GPL(sym)
 523 #define EXPORT_SYMBOL_GPL_FUTURE(sym)
 524 #define EXPORT_UNUSED_SYMBOL(sym)
 525 #define EXPORT_UNUSED_SYMBOL_GPL(sym)
 526
 527 /* Given an address, look for it in the exception tables. */
 528 static inline const struct exception_table_entry *
 529 search_module_extables(unsigned long addr)
 530 {
 531         return NULL;
 532 }
 533
 534 static inline struct module *__module_address(unsigned long addr)
 535 {
 536         return NULL;
 537 }
 538
 539 static inline struct module *__module_text_address(unsigned long addr)
 540 {
 541         return NULL;
 542 }
 543
 544 static inline bool is_module_address(unsigned long addr)
 545 {
 546         return false;
 547 }
 548
 549 static inline bool is_module_text_address(unsigned long addr)
 550 {
 551         return false;
 552 }
 553
 554 /* Get/put a kernel symbol (calls should be symmetric) */
 555 #define symbol_get(x) ({ extern typeof(x) x __attribute__((weak)); &(x); })
 556 #define symbol_put(x) do { } while(0)
 557 #define symbol_put_addr(x) do { } while(0)
 558
 559 static inline void __module_get(struct module *module)
 560 {
 561 }
 562
 563 static inline int try_module_get(struct module *module)
 564 {
 565         return 1;
 566 }
 567
 568 static inline void module_put(struct module *module)
 569 {
 570 }
 571
 572 #define module_name(mod) "kernel"
 573
 574 /* For kallsyms to ask for address resolution.  NULL means not found. */
 575 static inline const char *module_address_lookup(unsigned long addr,
 576                                           unsigned long *symbolsize,
 577                                           unsigned long *offset,
 578                                           char **modname,
 579                                           char *namebuf)
 580 {
 581         return NULL;
 582 }
 583
 584 static inline int lookup_module_symbol_name(unsigned long addr, char *symname)
 585 {
 586         return -ERANGE;
 587 }
 588
 589 static inline int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name)
 590 {
 591         return -ERANGE;
 592 }
 593
 594 static inline int module_get_kallsym(unsigned int symnum, unsigned long *value,
 595                                         char *type, char *name,
 596                                         char *module_name, int *exported)
 597 {
 598         return -ERANGE;
 599 }
 600
 601 static inline unsigned long module_kallsyms_lookup_name(const char *name)
 602 {
 603         return 0;
 604 }
 605
 606 static inline int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
 607                                                            struct module *,
 608                                                            unsigned long),
 609                                                  void *data)
 610 {
 611         return 0;
 612 }
 613
 614 static inline int register_module_notifier(struct notifier_block * nb)
 615 {
 616         /* no events will happen anyway, so this can always succeed */
 617         return 0;
 618 }
 619
 620 static inline int unregister_module_notifier(struct notifier_block * nb)
 621 {
 622         return 0;
 623 }
 624
 625 #define module_put_and_exit(code) do_exit(code)
 626
 627 static inline void print_modules(void)
 628 {
 629 }
 630
 631 static inline void module_update_markers(void)
 632 {
 633 }
 634
 635 static inline void module_update_tracepoints(void)
 636 {
 637 }
 638
 639 static inline int module_get_iter_tracepoints(struct tracepoint_iter *iter)
 640 {
 641         return 0;
 642 }
 643
 644 #endif /* CONFIG_MODULES */
 645
 646 struct device_driver;
 647 #ifdef CONFIG_SYSFS
 648 struct module;
 649
 650 extern struct kset *module_kset;
 651 extern struct kobj_type module_ktype;
 652 extern int module_sysfs_initialized;
 653
 654 int mod_sysfs_init(struct module *mod);
 655 int mod_sysfs_setup(struct module *mod,
 656                            struct kernel_param *kparam,
 657                            unsigned int num_params);
 658 int module_add_modinfo_attrs(struct module *mod);
 659 void module_remove_modinfo_attrs(struct module *mod);
 660
 661 #else /* !CONFIG_SYSFS */
 662
 663 static inline int mod_sysfs_init(struct module *mod)
 664 {
 665         return 0;
 666 }
 667
 668 static inline int mod_sysfs_setup(struct module *mod,
 669                            struct kernel_param *kparam,
 670                            unsigned int num_params)
 671 {
 672         return 0;
 673 }
 674
 675 static inline int module_add_modinfo_attrs(struct module *mod)
 676 {
 677         return 0;
 678 }
 679
 680 static inline void module_remove_modinfo_attrs(struct module *mod)
 681 { }
 682
 683 #endif /* CONFIG_SYSFS */
 684
 685 #define symbol_request(x) try_then_request_module(symbol_get(x), "symbol:" #x)
 686
 687 /* BELOW HERE ALL THESE ARE OBSOLETE AND WILL VANISH */
 688
 689 #define __MODULE_STRING(x) __stringify(x)
 690
 691 #endif /* _LINUX_MODULE_H */