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/spinlock.h>
  10 #include <linux/list.h>
  11 #include <linux/stat.h>
  12 #include <linux/compiler.h>
  13 #include <linux/cache.h>
  14 #include <linux/kmod.h>
  15 #include <linux/elf.h>
  16 #include <linux/stringify.h>
  17 #include <linux/kobject.h>
  18 #include <linux/moduleparam.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 /* v850 toolchain 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 <EMAIL>[, NAME <EMAIL>]*[ and NAME <EMAIL>] */
 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         __attribute_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")))           \
 194         = MODULE_SYMBOL_PREFIX #sym;                            \
 195         static const struct kernel_symbol __ksymtab_##sym       \
 196         __attribute_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 /* Similar stuff for section attributes. */
 233 struct module_sect_attr
 234 {
 235         struct module_attribute mattr;
 236         char *name;
 237         unsigned long address;
 238 };
 239
 240 struct module_sect_attrs
 241 {
 242         struct attribute_group grp;
 243         int nsections;
 244         struct module_sect_attr attrs[0];
 245 };
 246
 247 struct module_param_attrs;
 248
 249 struct module
 250 {
 251         enum module_state state;
 252
 253         /* Member of list of modules */
 254         struct list_head list;
 255
 256         /* Unique handle for this module */
 257         char name[MODULE_NAME_LEN];
 258
 259         /* Sysfs stuff. */
 260         struct module_kobject mkobj;
 261         struct module_param_attrs *param_attrs;
 262         struct module_attribute *modinfo_attrs;
 263         const char *version;
 264         const char *srcversion;
 265         struct kobject *holders_dir;
 266
 267         /* Exported symbols */
 268         const struct kernel_symbol *syms;
 269         unsigned int num_syms;
 270         const unsigned long *crcs;
 271
 272         /* GPL-only exported symbols. */
 273         const struct kernel_symbol *gpl_syms;
 274         unsigned int num_gpl_syms;
 275         const unsigned long *gpl_crcs;
 276
 277         /* unused exported symbols. */
 278         const struct kernel_symbol *unused_syms;
 279         unsigned int num_unused_syms;
 280         const unsigned long *unused_crcs;
 281         /* GPL-only, unused exported symbols. */
 282         const struct kernel_symbol *unused_gpl_syms;
 283         unsigned int num_unused_gpl_syms;
 284         const unsigned long *unused_gpl_crcs;
 285
 286         /* symbols that will be GPL-only in the near future. */
 287         const struct kernel_symbol *gpl_future_syms;
 288         unsigned int num_gpl_future_syms;
 289         const unsigned long *gpl_future_crcs;
 290
 291         /* Exception table */
 292         unsigned int num_exentries;
 293         const 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 long init_size, core_size;
 306
 307         /* The size of the executable code in each section.  */
 308         unsigned long init_text_size, core_text_size;
 309
 310         /* The handle returned from unwind_add_table. */
 311         void *unwind_info;
 312
 313         /* Arch-specific module values */
 314         struct mod_arch_specific arch;
 315
 316         /* Am I unsafe to unload? */
 317         int unsafe;
 318
 319         unsigned int taints;    /* same bits as kernel:tainted */
 320
 321 #ifdef CONFIG_GENERIC_BUG
 322         /* Support for BUG */
 323         struct list_head bug_list;
 324         struct bug_entry *bug_table;
 325         unsigned num_bugs;
 326 #endif
 327
 328 #ifdef CONFIG_MODULE_UNLOAD
 329         /* Reference counts */
 330         struct module_ref ref[NR_CPUS];
 331
 332         /* What modules depend on me? */
 333         struct list_head modules_which_use_me;
 334
 335         /* Who is waiting for us to be unloaded */
 336         struct task_struct *waiter;
 337
 338         /* Destruction function. */
 339         void (*exit)(void);
 340 #endif
 341
 342 #ifdef CONFIG_KALLSYMS
 343         /* We keep the symbol and string tables for kallsyms. */
 344         Elf_Sym *symtab;
 345         unsigned long num_symtab;
 346         char *strtab;
 347
 348         /* Section attributes */
 349         struct module_sect_attrs *sect_attrs;
 350 #endif
 351
 352         /* Per-cpu data. */
 353         void *percpu;
 354
 355         /* The command line arguments (may be mangled).  People like
 356            keeping pointers to this stuff */
 357         char *args;
 358 };
 359
 360 /* FIXME: It'd be nice to isolate modules during init, too, so they
 361    aren't used before they (may) fail.  But presently too much code
 362    (IDE & SCSI) require entry into the module during init.*/
 363 static inline int module_is_live(struct module *mod)
 364 {
 365         return mod->state != MODULE_STATE_GOING;
 366 }
 367
 368 /* Is this address in a module? (second is with no locks, for oops) */
 369 struct module *module_text_address(unsigned long addr);
 370 struct module *__module_text_address(unsigned long addr);
 371 int is_module_address(unsigned long addr);
 372
 373 /* Returns module and fills in value, defined and namebuf, or NULL if
 374    symnum out of range. */
 375 struct module *module_get_kallsym(unsigned int symnum, unsigned long *value,
 376                                 char *type, char *name, size_t namelen);
 377
 378 /* Look for this name: can be of form module:name. */
 379 unsigned long module_kallsyms_lookup_name(const char *name);
 380
 381 int is_exported(const char *name, const struct module *mod);
 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
 460 /* For extable.c to search modules' exception tables. */
 461 const struct exception_table_entry *search_module_extables(unsigned long addr);
 462
 463 int register_module_notifier(struct notifier_block * nb);
 464 int unregister_module_notifier(struct notifier_block * nb);
 465
 466 extern void print_modules(void);
 467
 468 #else /* !CONFIG_MODULES... */
 469 #define EXPORT_SYMBOL(sym)
 470 #define EXPORT_SYMBOL_GPL(sym)
 471 #define EXPORT_SYMBOL_GPL_FUTURE(sym)
 472 #define EXPORT_UNUSED_SYMBOL(sym)
 473 #define EXPORT_UNUSED_SYMBOL_GPL(sym)
 474
 475 /* Given an address, look for it in the exception tables. */
 476 static inline const struct exception_table_entry *
 477 search_module_extables(unsigned long addr)
 478 {
 479         return NULL;
 480 }
 481
 482 /* Is this address in a module? */
 483 static inline struct module *module_text_address(unsigned long addr)
 484 {
 485         return NULL;
 486 }
 487
 488 /* Is this address in a module? (don't take a lock, we're oopsing) */
 489 static inline struct module *__module_text_address(unsigned long addr)
 490 {
 491         return NULL;
 492 }
 493
 494 static inline int is_module_address(unsigned long addr)
 495 {
 496         return 0;
 497 }
 498
 499 /* Get/put a kernel symbol (calls should be symmetric) */
 500 #define symbol_get(x) ({ extern typeof(x) x __attribute__((weak)); &(x); })
 501 #define symbol_put(x) do { } while(0)
 502 #define symbol_put_addr(x) do { } while(0)
 503
 504 static inline void __module_get(struct module *module)
 505 {
 506 }
 507
 508 static inline int try_module_get(struct module *module)
 509 {
 510         return 1;
 511 }
 512
 513 static inline void module_put(struct module *module)
 514 {
 515 }
 516
 517 #define module_name(mod) "kernel"
 518
 519 #define __unsafe(mod)
 520
 521 /* For kallsyms to ask for address resolution.  NULL means not found. */
 522 static inline const char *module_address_lookup(unsigned long addr,
 523                                                 unsigned long *symbolsize,
 524                                                 unsigned long *offset,
 525                                                 char **modname)
 526 {
 527         return NULL;
 528 }
 529
 530 static inline struct module *module_get_kallsym(unsigned int symnum,
 531                                                 unsigned long *value,
 532                                                 char *type, char *name,
 533                                                 size_t namelen)
 534 {
 535         return NULL;
 536 }
 537
 538 static inline unsigned long module_kallsyms_lookup_name(const char *name)
 539 {
 540         return 0;
 541 }
 542
 543 static inline int is_exported(const char *name, const struct module *mod)
 544 {
 545         return 0;
 546 }
 547
 548 static inline int register_module_notifier(struct notifier_block * nb)
 549 {
 550         /* no events will happen anyway, so this can always succeed */
 551         return 0;
 552 }
 553
 554 static inline int unregister_module_notifier(struct notifier_block * nb)
 555 {
 556         return 0;
 557 }
 558
 559 #define module_put_and_exit(code) do_exit(code)
 560
 561 static inline void print_modules(void)
 562 {
 563 }
 564
 565 #endif /* CONFIG_MODULES */
 566
 567 struct device_driver;
 568 #ifdef CONFIG_SYSFS
 569 struct module;
 570
 571 extern struct subsystem module_subsys;
 572
 573 int mod_sysfs_init(struct module *mod);
 574 int mod_sysfs_setup(struct module *mod,
 575                            struct kernel_param *kparam,
 576                            unsigned int num_params);
 577 int module_add_modinfo_attrs(struct module *mod);
 578 void module_remove_modinfo_attrs(struct module *mod);
 579
 580 #else /* !CONFIG_SYSFS */
 581
 582 static inline int mod_sysfs_init(struct module *mod)
 583 {
 584         return 0;
 585 }
 586
 587 static inline int mod_sysfs_setup(struct module *mod,
 588                            struct kernel_param *kparam,
 589                            unsigned int num_params)
 590 {
 591         return 0;
 592 }
 593
 594 static inline int module_add_modinfo_attrs(struct module *mod)
 595 {
 596         return 0;
 597 }
 598
 599 static inline void module_remove_modinfo_attrs(struct module *mod)
 600 { }
 601
 602 #endif /* CONFIG_SYSFS */
 603
 604 #if defined(CONFIG_SYSFS) && defined(CONFIG_MODULES)
 605
 606 void module_add_driver(struct module *mod, struct device_driver *drv);
 607 void module_remove_driver(struct device_driver *drv);
 608
 609 #else /* not both CONFIG_SYSFS && CONFIG_MODULES */
 610
 611 static inline void module_add_driver(struct module *mod, struct device_driver *drv)
 612 { }
 613
 614 static inline void module_remove_driver(struct device_driver *drv)
 615 { }
 616
 617 #endif
 618
 619 #define symbol_request(x) try_then_request_module(symbol_get(x), "symbol:" #x)
 620
 621 /* BELOW HERE ALL THESE ARE OBSOLETE AND WILL VANISH */
 622
 623 #define __MODULE_STRING(x) __stringify(x)
 624
 625 #endif /* _LINUX_MODULE_H */