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 <asm/local.h>
  19
  20 #include <asm/module.h>
  21
  22 /* Not Yet Implemented */
  23 #define MODULE_SUPPORTED_DEVICE(name)
  24
  25 /* v850 toolchain uses a `_' prefix for all user symbols */
  26 #ifndef MODULE_SYMBOL_PREFIX
  27 #define MODULE_SYMBOL_PREFIX ""
  28 #endif
  29
  30 #define MODULE_NAME_LEN (64 - sizeof(unsigned long))
  31
  32 struct kernel_symbol
  33 {
  34         unsigned long value;
  35         const char *name;
  36 };
  37
  38 struct modversion_info
  39 {
  40         unsigned long crc;
  41         char name[MODULE_NAME_LEN];
  42 };
  43
  44 struct module;
  45
  46 struct module_attribute {
  47         struct attribute attr;
  48         ssize_t (*show)(struct module_attribute *, struct module *, char *);
  49         ssize_t (*store)(struct module_attribute *, struct module *,
  50                          const char *, size_t count);
  51         void (*setup)(struct module *, const char *);
  52         int (*test)(struct module *);
  53         void (*free)(struct module *);
  54 };
  55
  56 struct module_kobject
  57 {
  58         struct kobject kobj;
  59         struct module *mod;
  60         struct kobject *drivers_dir;
  61 };
  62
  63 /* These are either module local, or the kernel's dummy ones. */
  64 extern int init_module(void);
  65 extern void cleanup_module(void);
  66
  67 /* Archs provide a method of finding the correct exception table. */
  68 struct exception_table_entry;
  69
  70 const struct exception_table_entry *
  71 search_extable(const struct exception_table_entry *first,
  72                const struct exception_table_entry *last,
  73                unsigned long value);
  74 void sort_extable(struct exception_table_entry *start,
  75                   struct exception_table_entry *finish);
  76 void sort_main_extable(void);
  77
  78 #ifdef MODULE
  79 #define MODULE_GENERIC_TABLE(gtype,name)                        \
  80 extern const struct gtype##_id __mod_##gtype##_table            \
  81   __attribute__ ((unused, alias(__stringify(name))))
  82
  83 extern struct module __this_module;
  84 #define THIS_MODULE (&__this_module)
  85 #else  /* !MODULE */
  86 #define MODULE_GENERIC_TABLE(gtype,name)
  87 #define THIS_MODULE ((struct module *)0)
  88 #endif
  89
  90 /* Generic info of form tag = "info" */
  91 #define MODULE_INFO(tag, info) __MODULE_INFO(tag, tag, info)
  92
  93 /* For userspace: you can also call me... */
  94 #define MODULE_ALIAS(_alias) MODULE_INFO(alias, _alias)
  95
  96 /*
  97  * The following license idents are currently accepted as indicating free
  98  * software modules
  99  *
 100  *      "GPL"                           [GNU Public License v2 or later]
 101  *      "GPL v2"                        [GNU Public License v2]
 102  *      "GPL and additional rights"     [GNU Public License v2 rights and more]
 103  *      "Dual BSD/GPL"                  [GNU Public License v2
 104  *                                       or BSD license choice]
 105  *      "Dual MIT/GPL"                  [GNU Public License v2
 106  *                                       or MIT license choice]
 107  *      "Dual MPL/GPL"                  [GNU Public License v2
 108  *                                       or Mozilla license choice]
 109  *
 110  * The following other idents are available
 111  *
 112  *      "Proprietary"                   [Non free products]
 113  *
 114  * There are dual licensed components, but when running with Linux it is the
 115  * GPL that is relevant so this is a non issue. Similarly LGPL linked with GPL
 116  * is a GPL combined work.
 117  *
 118  * This exists for several reasons
 119  * 1.   So modinfo can show license info for users wanting to vet their setup
 120  *      is free
 121  * 2.   So the community can ignore bug reports including proprietary modules
 122  * 3.   So vendors can do likewise based on their own policies
 123  */
 124 #define MODULE_LICENSE(_license) MODULE_INFO(license, _license)
 125
 126 /* Author, ideally of form NAME[, NAME]*[ and NAME] */
 127 #define MODULE_AUTHOR(_author) MODULE_INFO(author, _author)
 128
 129 /* What your module does. */
 130 #define MODULE_DESCRIPTION(_description) MODULE_INFO(description, _description)
 131
 132 /* One for each parameter, describing how to use it.  Some files do
 133    multiple of these per line, so can't just use MODULE_INFO. */
 134 #define MODULE_PARM_DESC(_parm, desc) \
 135         __MODULE_INFO(parm, _parm, #_parm ":" desc)
 136
 137 #define MODULE_DEVICE_TABLE(type,name)          \
 138   MODULE_GENERIC_TABLE(type##_device,name)
 139
 140 /* Version of form [<epoch>:]<version>[-<extra-version>].
 141    Or for CVS/RCS ID version, everything but the number is stripped.
 142   <epoch>: A (small) unsigned integer which allows you to start versions
 143            anew. If not mentioned, it's zero.  eg. "2:1.0" is after
 144            "1:2.0".
 145   <version>: The <version> may contain only alphanumerics and the
 146            character `.'.  Ordered by numeric sort for numeric parts,
 147            ascii sort for ascii parts (as per RPM or DEB algorithm).
 148   <extraversion>: Like <version>, but inserted for local
 149            customizations, eg "rh3" or "rusty1".
 150
 151   Using this automatically adds a checksum of the .c files and the
 152   local headers in "srcversion".
 153 */
 154 #define MODULE_VERSION(_version) MODULE_INFO(version, _version)
 155
 156 /* Optional firmware file (or files) needed by the module
 157  * format is simply firmware file name.  Multiple firmware
 158  * files require multiple MODULE_FIRMWARE() specifiers */
 159 #define MODULE_FIRMWARE(_firmware) MODULE_INFO(firmware, _firmware)
 160
 161 /* Given an address, look for it in the exception tables */
 162 const struct exception_table_entry *search_exception_tables(unsigned long add);
 163
 164 struct notifier_block;
 165
 166 #ifdef CONFIG_MODULES
 167
 168 /* Get/put a kernel symbol (calls must be symmetric) */
 169 void *__symbol_get(const char *symbol);
 170 void *__symbol_get_gpl(const char *symbol);
 171 #define symbol_get(x) ((typeof(&x))(__symbol_get(MODULE_SYMBOL_PREFIX #x)))
 172
 173 #ifndef __GENKSYMS__
 174 #ifdef CONFIG_MODVERSIONS
 175 /* Mark the CRC weak since genksyms apparently decides not to
 176  * generate a checksums for some symbols */
 177 #define __CRC_SYMBOL(sym, sec)                                  \
 178         extern void *__crc_##sym __attribute__((weak));         \
 179         static const unsigned long __kcrctab_##sym              \
 180         __attribute_used__                                      \
 181         __attribute__((section("__kcrctab" sec), unused))       \
 182         = (unsigned long) &__crc_##sym;
 183 #else
 184 #define __CRC_SYMBOL(sym, sec)
 185 #endif
 186
 187 /* For every exported symbol, place a struct in the __ksymtab section */
 188 #define __EXPORT_SYMBOL(sym, sec)                               \
 189         extern typeof(sym) sym;                                 \
 190         __CRC_SYMBOL(sym, sec)                                  \
 191         static const char __kstrtab_##sym[]                     \
 192         __attribute__((section("__ksymtab_strings")))           \
 193         = MODULE_SYMBOL_PREFIX #sym;                            \
 194         static const struct kernel_symbol __ksymtab_##sym       \
 195         __attribute_used__                                      \
 196         __attribute__((section("__ksymtab" sec), unused))       \
 197         = { (unsigned long)&sym, __kstrtab_##sym }
 198
 199 #define EXPORT_SYMBOL(sym)                                      \
 200         __EXPORT_SYMBOL(sym, "")
 201
 202 #define EXPORT_SYMBOL_GPL(sym)                                  \
 203         __EXPORT_SYMBOL(sym, "_gpl")
 204
 205 #define EXPORT_SYMBOL_GPL_FUTURE(sym)                           \
 206         __EXPORT_SYMBOL(sym, "_gpl_future")
 207
 208
 209 #ifdef CONFIG_UNUSED_SYMBOLS
 210 #define EXPORT_UNUSED_SYMBOL(sym) __EXPORT_SYMBOL(sym, "_unused")
 211 #define EXPORT_UNUSED_SYMBOL_GPL(sym) __EXPORT_SYMBOL(sym, "_unused_gpl")
 212 #else
 213 #define EXPORT_UNUSED_SYMBOL(sym)
 214 #define EXPORT_UNUSED_SYMBOL_GPL(sym)
 215 #endif
 216
 217 #endif
 218
 219 struct module_ref
 220 {
 221         local_t count;
 222 } ____cacheline_aligned;
 223
 224 enum module_state
 225 {
 226         MODULE_STATE_LIVE,
 227         MODULE_STATE_COMING,
 228         MODULE_STATE_GOING,
 229 };
 230
 231 /* Similar stuff for section attributes. */
 232 struct module_sect_attr
 233 {
 234         struct module_attribute mattr;
 235         char *name;
 236         unsigned long address;
 237 };
 238
 239 struct module_sect_attrs
 240 {
 241         struct attribute_group grp;
 242         int nsections;
 243         struct module_sect_attr attrs[0];
 244 };
 245
 246 struct module_param_attrs;
 247
 248 struct module
 249 {
 250         enum module_state state;
 251
 252         /* Member of list of modules */
 253         struct list_head list;
 254
 255         /* Unique handle for this module */
 256         char name[MODULE_NAME_LEN];
 257
 258         /* Sysfs stuff. */
 259         struct module_kobject mkobj;
 260         struct module_param_attrs *param_attrs;
 261         struct module_attribute *modinfo_attrs;
 262         const char *version;
 263         const char *srcversion;
 264         struct kobject *holders_dir;
 265
 266         /* Exported symbols */
 267         const struct kernel_symbol *syms;
 268         unsigned int num_syms;
 269         const unsigned long *crcs;
 270
 271         /* GPL-only exported symbols. */
 272         const struct kernel_symbol *gpl_syms;
 273         unsigned int num_gpl_syms;
 274         const unsigned long *gpl_crcs;
 275
 276         /* unused exported symbols. */
 277         const struct kernel_symbol *unused_syms;
 278         unsigned int num_unused_syms;
 279         const unsigned long *unused_crcs;
 280         /* GPL-only, unused exported symbols. */
 281         const struct kernel_symbol *unused_gpl_syms;
 282         unsigned int num_unused_gpl_syms;
 283         const unsigned long *unused_gpl_crcs;
 284
 285         /* symbols that will be GPL-only in the near future. */
 286         const struct kernel_symbol *gpl_future_syms;
 287         unsigned int num_gpl_future_syms;
 288         const unsigned long *gpl_future_crcs;
 289
 290         /* Exception table */
 291         unsigned int num_exentries;
 292         const struct exception_table_entry *extable;
 293
 294         /* Startup function. */
 295         int (*init)(void);
 296
 297         /* If this is non-NULL, vfree after init() returns */
 298         void *module_init;
 299
 300         /* Here is the actual code + data, vfree'd on unload. */
 301         void *module_core;
 302
 303         /* Here are the sizes of the init and core sections */
 304         unsigned long init_size, core_size;
 305
 306         /* The size of the executable code in each section.  */
 307         unsigned long init_text_size, core_text_size;
 308
 309         /* The handle returned from unwind_add_table. */
 310         void *unwind_info;
 311
 312         /* Arch-specific module values */
 313         struct mod_arch_specific arch;
 314
 315         /* Am I unsafe to unload? */
 316         int unsafe;
 317
 318         unsigned int taints;    /* same bits as kernel:tainted */
 319
 320 #ifdef CONFIG_GENERIC_BUG
 321         /* Support for BUG */
 322         struct list_head bug_list;
 323         struct bug_entry *bug_table;
 324         unsigned num_bugs;
 325 #endif
 326
 327 #ifdef CONFIG_MODULE_UNLOAD
 328         /* Reference counts */
 329         struct module_ref ref[NR_CPUS];
 330
 331         /* What modules depend on me? */
 332         struct list_head modules_which_use_me;
 333
 334         /* Who is waiting for us to be unloaded */
 335         struct task_struct *waiter;
 336
 337         /* Destruction function. */
 338         void (*exit)(void);
 339 #endif
 340
 341 #ifdef CONFIG_KALLSYMS
 342         /* We keep the symbol and string tables for kallsyms. */
 343         Elf_Sym *symtab;
 344         unsigned long num_symtab;
 345         char *strtab;
 346
 347         /* Section attributes */
 348         struct module_sect_attrs *sect_attrs;
 349 #endif
 350
 351         /* Per-cpu data. */
 352         void *percpu;
 353
 354         /* The command line arguments (may be mangled).  People like
 355            keeping pointers to this stuff */
 356         char *args;
 357 };
 358 #ifndef MODULE_ARCH_INIT
 359 #define MODULE_ARCH_INIT {}
 360 #endif
 361
 362 /* FIXME: It'd be nice to isolate modules during init, too, so they
 363    aren't used before they (may) fail.  But presently too much code
 364    (IDE & SCSI) require entry into the module during init.*/
 365 static inline int module_is_live(struct module *mod)
 366 {
 367         return mod->state != MODULE_STATE_GOING;
 368 }
 369
 370 /* Is this address in a module? (second is with no locks, for oops) */
 371 struct module *module_text_address(unsigned long addr);
 372 struct module *__module_text_address(unsigned long addr);
 373 int is_module_address(unsigned long addr);
 374
 375 /* Returns 0 and fills in value, defined and namebuf, or -ERANGE if
 376    symnum out of range. */
 377 int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
 378                         char *name, char *module_name, int *exported);
 379
 380 /* Look for this name: can be of form module:name. */
 381 unsigned long module_kallsyms_lookup_name(const char *name);
 382
 383 extern void __module_put_and_exit(struct module *mod, long code)
 384         __attribute__((noreturn));
 385 #define module_put_and_exit(code) __module_put_and_exit(THIS_MODULE, code);
 386
 387 #ifdef CONFIG_MODULE_UNLOAD
 388 unsigned int module_refcount(struct module *mod);
 389 void __symbol_put(const char *symbol);
 390 #define symbol_put(x) __symbol_put(MODULE_SYMBOL_PREFIX #x)
 391 void symbol_put_addr(void *addr);
 392
 393 /* Sometimes we know we already have a refcount, and it's easier not
 394    to handle the error case (which only happens with rmmod --wait). */
 395 static inline void __module_get(struct module *module)
 396 {
 397         if (module) {
 398                 BUG_ON(module_refcount(module) == 0);
 399                 local_inc(&module->ref[get_cpu()].count);
 400                 put_cpu();
 401         }
 402 }
 403
 404 static inline int try_module_get(struct module *module)
 405 {
 406         int ret = 1;
 407
 408         if (module) {
 409                 unsigned int cpu = get_cpu();
 410                 if (likely(module_is_live(module)))
 411                         local_inc(&module->ref[cpu].count);
 412                 else
 413                         ret = 0;
 414                 put_cpu();
 415         }
 416         return ret;
 417 }
 418
 419 extern void module_put(struct module *module);
 420
 421 #else /*!CONFIG_MODULE_UNLOAD*/
 422 static inline int try_module_get(struct module *module)
 423 {
 424         return !module || module_is_live(module);
 425 }
 426 static inline void module_put(struct module *module)
 427 {
 428 }
 429 static inline void __module_get(struct module *module)
 430 {
 431 }
 432 #define symbol_put(x) do { } while(0)
 433 #define symbol_put_addr(p) do { } while(0)
 434
 435 #endif /* CONFIG_MODULE_UNLOAD */
 436
 437 /* This is a #define so the string doesn't get put in every .o file */
 438 #define module_name(mod)                        \
 439 ({                                              \
 440         struct module *__mod = (mod);           \
 441         __mod ? __mod->name : "kernel";         \
 442 })
 443
 444 #define __unsafe(mod)                                                        \
 445 do {                                                                         \
 446         if (mod && !(mod)->unsafe) {                                         \
 447                 printk(KERN_WARNING                                          \
 448                        "Module %s cannot be unloaded due to unsafe usage in" \
 449                        " %s:%u\n", (mod)->name, __FILE__, __LINE__);         \
 450                 (mod)->unsafe = 1;                                           \
 451         }                                                                    \
 452 } while(0)
 453
 454 /* For kallsyms to ask for address resolution.  NULL means not found. */
 455 const char *module_address_lookup(unsigned long addr,
 456                                   unsigned long *symbolsize,
 457                                   unsigned long *offset,
 458                                   char **modname);
 459 int lookup_module_symbol_name(unsigned long addr, char *symname);
 460 int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name);
 461
 462 /* For extable.c to search modules' exception tables. */
 463 const struct exception_table_entry *search_module_extables(unsigned long addr);
 464
 465 int register_module_notifier(struct notifier_block * nb);
 466 int unregister_module_notifier(struct notifier_block * nb);
 467
 468 extern void print_modules(void);
 469
 470 #else /* !CONFIG_MODULES... */
 471 #define EXPORT_SYMBOL(sym)
 472 #define EXPORT_SYMBOL_GPL(sym)
 473 #define EXPORT_SYMBOL_GPL_FUTURE(sym)
 474 #define EXPORT_UNUSED_SYMBOL(sym)
 475 #define EXPORT_UNUSED_SYMBOL_GPL(sym)
 476
 477 /* Given an address, look for it in the exception tables. */
 478 static inline const struct exception_table_entry *
 479 search_module_extables(unsigned long addr)
 480 {
 481         return NULL;
 482 }
 483
 484 /* Is this address in a module? */
 485 static inline struct module *module_text_address(unsigned long addr)
 486 {
 487         return NULL;
 488 }
 489
 490 /* Is this address in a module? (don't take a lock, we're oopsing) */
 491 static inline struct module *__module_text_address(unsigned long addr)
 492 {
 493         return NULL;
 494 }
 495
 496 static inline int is_module_address(unsigned long addr)
 497 {
 498         return 0;
 499 }
 500
 501 /* Get/put a kernel symbol (calls should be symmetric) */
 502 #define symbol_get(x) ({ extern typeof(x) x __attribute__((weak)); &(x); })
 503 #define symbol_put(x) do { } while(0)
 504 #define symbol_put_addr(x) do { } while(0)
 505
 506 static inline void __module_get(struct module *module)
 507 {
 508 }
 509
 510 static inline int try_module_get(struct module *module)
 511 {
 512         return 1;
 513 }
 514
 515 static inline void module_put(struct module *module)
 516 {
 517 }
 518
 519 #define module_name(mod) "kernel"
 520
 521 #define __unsafe(mod)
 522
 523 /* For kallsyms to ask for address resolution.  NULL means not found. */
 524 static inline const char *module_address_lookup(unsigned long addr,
 525                                                 unsigned long *symbolsize,
 526                                                 unsigned long *offset,
 527                                                 char **modname)
 528 {
 529         return NULL;
 530 }
 531
 532 static inline int lookup_module_symbol_name(unsigned long addr, char *symname)
 533 {
 534         return -ERANGE;
 535 }
 536
 537 static inline int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name)
 538 {
 539         return -ERANGE;
 540 }
 541
 542 static inline int module_get_kallsym(unsigned int symnum, unsigned long *value,
 543                                         char *type, char *name,
 544                                         char *module_name, int *exported)
 545 {
 546         return -ERANGE;
 547 }
 548
 549 static inline unsigned long module_kallsyms_lookup_name(const char *name)
 550 {
 551         return 0;
 552 }
 553
 554 static inline int register_module_notifier(struct notifier_block * nb)
 555 {
 556         /* no events will happen anyway, so this can always succeed */
 557         return 0;
 558 }
 559
 560 static inline int unregister_module_notifier(struct notifier_block * nb)
 561 {
 562         return 0;
 563 }
 564
 565 #define module_put_and_exit(code) do_exit(code)
 566
 567 static inline void print_modules(void)
 568 {
 569 }
 570
 571 #endif /* CONFIG_MODULES */
 572
 573 struct device_driver;
 574 #ifdef CONFIG_SYSFS
 575 struct module;
 576
 577 extern struct kset module_subsys;
 578
 579 int mod_sysfs_init(struct module *mod);
 580 int mod_sysfs_setup(struct module *mod,
 581                            struct kernel_param *kparam,
 582                            unsigned int num_params);
 583 int module_add_modinfo_attrs(struct module *mod);
 584 void module_remove_modinfo_attrs(struct module *mod);
 585
 586 #else /* !CONFIG_SYSFS */
 587
 588 static inline int mod_sysfs_init(struct module *mod)
 589 {
 590         return 0;
 591 }
 592
 593 static inline int mod_sysfs_setup(struct module *mod,
 594                            struct kernel_param *kparam,
 595                            unsigned int num_params)
 596 {
 597         return 0;
 598 }
 599
 600 static inline int module_add_modinfo_attrs(struct module *mod)
 601 {
 602         return 0;
 603 }
 604
 605 static inline void module_remove_modinfo_attrs(struct module *mod)
 606 { }
 607
 608 #endif /* CONFIG_SYSFS */
 609
 610 #if defined(CONFIG_SYSFS) && defined(CONFIG_MODULES)
 611
 612 void module_add_driver(struct module *mod, struct device_driver *drv);
 613 void module_remove_driver(struct device_driver *drv);
 614
 615 #else /* not both CONFIG_SYSFS && CONFIG_MODULES */
 616
 617 static inline void module_add_driver(struct module *mod, struct device_driver *drv)
 618 { }
 619
 620 static inline void module_remove_driver(struct device_driver *drv)
 621 { }
 622
 623 #endif
 624
 625 #define symbol_request(x) try_then_request_module(symbol_get(x), "symbol:" #x)
 626
 627 /* BELOW HERE ALL THESE ARE OBSOLETE AND WILL VANISH */
 628
 629 #define __MODULE_STRING(x) __stringify(x)
 630
 631 #endif /* _LINUX_MODULE_H */