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