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