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/sched.h>
  10 #include <linux/spinlock.h>
  11 #include <linux/list.h>
  12 #include <linux/stat.h>
  13 #include <linux/compiler.h>
  14 #include <linux/cache.h>
  15 #include <linux/kmod.h>
  16 #include <linux/elf.h>
  17 #include <linux/stringify.h>
  18 #include <linux/kobject.h>
  19 #include <linux/moduleparam.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 /* v850 toolchain 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 (64 - sizeof(unsigned long))
  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 };
  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 extern struct subsystem module_subsys;
  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 <EMAIL>[, NAME <EMAIL>]*[ and NAME <EMAIL>] */
 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 /* Given an address, look for it in the exception tables */
 160 const struct exception_table_entry *search_exception_tables(unsigned long add);
 161
 162 struct notifier_block;
 163
 164 #ifdef CONFIG_MODULES
 165
 166 /* Get/put a kernel symbol (calls must be symmetric) */
 167 void *__symbol_get(const char *symbol);
 168 void *__symbol_get_gpl(const char *symbol);
 169 #define symbol_get(x) ((typeof(&x))(__symbol_get(MODULE_SYMBOL_PREFIX #x)))
 170
 171 #ifndef __GENKSYMS__
 172 #ifdef CONFIG_MODVERSIONS
 173 /* Mark the CRC weak since genksyms apparently decides not to
 174  * generate a checksums for some symbols */
 175 #define __CRC_SYMBOL(sym, sec)                                  \
 176         extern void *__crc_##sym __attribute__((weak));         \
 177         static const unsigned long __kcrctab_##sym              \
 178         __attribute_used__                                      \
 179         __attribute__((section("__kcrctab" sec), unused))       \
 180         = (unsigned long) &__crc_##sym;
 181 #else
 182 #define __CRC_SYMBOL(sym, sec)
 183 #endif
 184
 185 /* For every exported symbol, place a struct in the __ksymtab section */
 186 #define __EXPORT_SYMBOL(sym, sec)                               \
 187         extern typeof(sym) sym;                                 \
 188         __CRC_SYMBOL(sym, sec)                                  \
 189         static const char __kstrtab_##sym[]                     \
 190         __attribute__((section("__ksymtab_strings")))           \
 191         = MODULE_SYMBOL_PREFIX #sym;                            \
 192         static const struct kernel_symbol __ksymtab_##sym       \
 193         __attribute_used__                                      \
 194         __attribute__((section("__ksymtab" sec), unused))       \
 195         = { (unsigned long)&sym, __kstrtab_##sym }
 196
 197 #define EXPORT_SYMBOL(sym)                                      \
 198         __EXPORT_SYMBOL(sym, "")
 199
 200 #define EXPORT_SYMBOL_GPL(sym)                                  \
 201         __EXPORT_SYMBOL(sym, "_gpl")
 202
 203 #define EXPORT_SYMBOL_GPL_FUTURE(sym)                           \
 204         __EXPORT_SYMBOL(sym, "_gpl_future")
 205
 206 #endif
 207
 208 struct module_ref
 209 {
 210         local_t count;
 211 } ____cacheline_aligned;
 212
 213 enum module_state
 214 {
 215         MODULE_STATE_LIVE,
 216         MODULE_STATE_COMING,
 217         MODULE_STATE_GOING,
 218 };
 219
 220 /* Similar stuff for section attributes. */
 221 #define MODULE_SECT_NAME_LEN 32
 222 struct module_sect_attr
 223 {
 224         struct module_attribute mattr;
 225         char name[MODULE_SECT_NAME_LEN];
 226         unsigned long address;
 227 };
 228
 229 struct module_sect_attrs
 230 {
 231         struct attribute_group grp;
 232         struct module_sect_attr attrs[0];
 233 };
 234
 235 struct module_param_attrs;
 236
 237 struct module
 238 {
 239         enum module_state state;
 240
 241         /* Member of list of modules */
 242         struct list_head list;
 243
 244         /* Unique handle for this module */
 245         char name[MODULE_NAME_LEN];
 246
 247         /* Sysfs stuff. */
 248         struct module_kobject mkobj;
 249         struct module_param_attrs *param_attrs;
 250         struct module_attribute *modinfo_attrs;
 251         const char *version;
 252         const char *srcversion;
 253
 254         /* Exported symbols */
 255         const struct kernel_symbol *syms;
 256         unsigned int num_syms;
 257         const unsigned long *crcs;
 258
 259         /* GPL-only exported symbols. */
 260         const struct kernel_symbol *gpl_syms;
 261         unsigned int num_gpl_syms;
 262         const unsigned long *gpl_crcs;
 263
 264         /* symbols that will be GPL-only in the near future. */
 265         const struct kernel_symbol *gpl_future_syms;
 266         unsigned int num_gpl_future_syms;
 267         const unsigned long *gpl_future_crcs;
 268
 269         /* Exception table */
 270         unsigned int num_exentries;
 271         const struct exception_table_entry *extable;
 272
 273         /* Startup function. */
 274         int (*init)(void);
 275
 276         /* If this is non-NULL, vfree after init() returns */
 277         void *module_init;
 278
 279         /* Here is the actual code + data, vfree'd on unload. */
 280         void *module_core;
 281
 282         /* Here are the sizes of the init and core sections */
 283         unsigned long init_size, core_size;
 284
 285         /* The size of the executable code in each section.  */
 286         unsigned long init_text_size, core_text_size;
 287
 288         /* Arch-specific module values */
 289         struct mod_arch_specific arch;
 290
 291         /* Am I unsafe to unload? */
 292         int unsafe;
 293
 294         /* Am I GPL-compatible */
 295         int license_gplok;
 296
 297 #ifdef CONFIG_MODULE_UNLOAD
 298         /* Reference counts */
 299         struct module_ref ref[NR_CPUS];
 300
 301         /* What modules depend on me? */
 302         struct list_head modules_which_use_me;
 303
 304         /* Who is waiting for us to be unloaded */
 305         struct task_struct *waiter;
 306
 307         /* Destruction function. */
 308         void (*exit)(void);
 309 #endif
 310
 311 #ifdef CONFIG_KALLSYMS
 312         /* We keep the symbol and string tables for kallsyms. */
 313         Elf_Sym *symtab;
 314         unsigned long num_symtab;
 315         char *strtab;
 316
 317         /* Section attributes */
 318         struct module_sect_attrs *sect_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 };
 328
 329 /* FIXME: It'd be nice to isolate modules during init, too, so they
 330    aren't used before they (may) fail.  But presently too much code
 331    (IDE & SCSI) require entry into the module during init.*/
 332 static inline int module_is_live(struct module *mod)
 333 {
 334         return mod->state != MODULE_STATE_GOING;
 335 }
 336
 337 /* Is this address in a module? (second is with no locks, for oops) */
 338 struct module *module_text_address(unsigned long addr);
 339 struct module *__module_text_address(unsigned long addr);
 340
 341 /* Returns module and fills in value, defined and namebuf, or NULL if
 342    symnum out of range. */
 343 struct module *module_get_kallsym(unsigned int symnum,
 344                                   unsigned long *value,
 345                                   char *type,
 346                                   char namebuf[128]);
 347
 348 /* Look for this name: can be of form module:name. */
 349 unsigned long module_kallsyms_lookup_name(const char *name);
 350
 351 int is_exported(const char *name, const struct module *mod);
 352
 353 extern void __module_put_and_exit(struct module *mod, long code)
 354         __attribute__((noreturn));
 355 #define module_put_and_exit(code) __module_put_and_exit(THIS_MODULE, code);
 356
 357 #ifdef CONFIG_MODULE_UNLOAD
 358 unsigned int module_refcount(struct module *mod);
 359 void __symbol_put(const char *symbol);
 360 #define symbol_put(x) __symbol_put(MODULE_SYMBOL_PREFIX #x)
 361 void symbol_put_addr(void *addr);
 362
 363 /* Sometimes we know we already have a refcount, and it's easier not
 364    to handle the error case (which only happens with rmmod --wait). */
 365 static inline void __module_get(struct module *module)
 366 {
 367         if (module) {
 368                 BUG_ON(module_refcount(module) == 0);
 369                 local_inc(&module->ref[get_cpu()].count);
 370                 put_cpu();
 371         }
 372 }
 373
 374 static inline int try_module_get(struct module *module)
 375 {
 376         int ret = 1;
 377
 378         if (module) {
 379                 unsigned int cpu = get_cpu();
 380                 if (likely(module_is_live(module)))
 381                         local_inc(&module->ref[cpu].count);
 382                 else
 383                         ret = 0;
 384                 put_cpu();
 385         }
 386         return ret;
 387 }
 388
 389 static inline void module_put(struct module *module)
 390 {
 391         if (module) {
 392                 unsigned int cpu = get_cpu();
 393                 local_dec(&module->ref[cpu].count);
 394                 /* Maybe they're waiting for us to drop reference? */
 395                 if (unlikely(!module_is_live(module)))
 396                         wake_up_process(module->waiter);
 397                 put_cpu();
 398         }
 399 }
 400
 401 #else /*!CONFIG_MODULE_UNLOAD*/
 402 static inline int try_module_get(struct module *module)
 403 {
 404         return !module || module_is_live(module);
 405 }
 406 static inline void module_put(struct module *module)
 407 {
 408 }
 409 static inline void __module_get(struct module *module)
 410 {
 411 }
 412 #define symbol_put(x) do { } while(0)
 413 #define symbol_put_addr(p) do { } while(0)
 414
 415 #endif /* CONFIG_MODULE_UNLOAD */
 416
 417 /* This is a #define so the string doesn't get put in every .o file */
 418 #define module_name(mod)                        \
 419 ({                                              \
 420         struct module *__mod = (mod);           \
 421         __mod ? __mod->name : "kernel";         \
 422 })
 423
 424 #define __unsafe(mod)                                                        \
 425 do {                                                                         \
 426         if (mod && !(mod)->unsafe) {                                         \
 427                 printk(KERN_WARNING                                          \
 428                        "Module %s cannot be unloaded due to unsafe usage in" \
 429                        " %s:%u\n", (mod)->name, __FILE__, __LINE__);         \
 430                 (mod)->unsafe = 1;                                           \
 431         }                                                                    \
 432 } while(0)
 433
 434 /* For kallsyms to ask for address resolution.  NULL means not found. */
 435 const char *module_address_lookup(unsigned long addr,
 436                                   unsigned long *symbolsize,
 437                                   unsigned long *offset,
 438                                   char **modname);
 439
 440 /* For extable.c to search modules' exception tables. */
 441 const struct exception_table_entry *search_module_extables(unsigned long addr);
 442
 443 int register_module_notifier(struct notifier_block * nb);
 444 int unregister_module_notifier(struct notifier_block * nb);
 445
 446 extern void print_modules(void);
 447
 448 struct device_driver;
 449 void module_add_driver(struct module *, struct device_driver *);
 450 void module_remove_driver(struct device_driver *);
 451
 452 #else /* !CONFIG_MODULES... */
 453 #define EXPORT_SYMBOL(sym)
 454 #define EXPORT_SYMBOL_GPL(sym)
 455 #define EXPORT_SYMBOL_GPL_FUTURE(sym)
 456
 457 /* Given an address, look for it in the exception tables. */
 458 static inline const struct exception_table_entry *
 459 search_module_extables(unsigned long addr)
 460 {
 461         return NULL;
 462 }
 463
 464 /* Is this address in a module? */
 465 static inline struct module *module_text_address(unsigned long addr)
 466 {
 467         return NULL;
 468 }
 469
 470 /* Is this address in a module? (don't take a lock, we're oopsing) */
 471 static inline struct module *__module_text_address(unsigned long addr)
 472 {
 473         return NULL;
 474 }
 475
 476 /* Get/put a kernel symbol (calls should be symmetric) */
 477 #define symbol_get(x) ({ extern typeof(x) x __attribute__((weak)); &(x); })
 478 #define symbol_put(x) do { } while(0)
 479 #define symbol_put_addr(x) do { } while(0)
 480
 481 static inline void __module_get(struct module *module)
 482 {
 483 }
 484
 485 static inline int try_module_get(struct module *module)
 486 {
 487         return 1;
 488 }
 489
 490 static inline void module_put(struct module *module)
 491 {
 492 }
 493
 494 #define module_name(mod) "kernel"
 495
 496 #define __unsafe(mod)
 497
 498 /* For kallsyms to ask for address resolution.  NULL means not found. */
 499 static inline const char *module_address_lookup(unsigned long addr,
 500                                                 unsigned long *symbolsize,
 501                                                 unsigned long *offset,
 502                                                 char **modname)
 503 {
 504         return NULL;
 505 }
 506
 507 static inline struct module *module_get_kallsym(unsigned int symnum,
 508                                                 unsigned long *value,
 509                                                 char *type,
 510                                                 char namebuf[128])
 511 {
 512         return NULL;
 513 }
 514
 515 static inline unsigned long module_kallsyms_lookup_name(const char *name)
 516 {
 517         return 0;
 518 }
 519
 520 static inline int is_exported(const char *name, const struct module *mod)
 521 {
 522         return 0;
 523 }
 524
 525 static inline int register_module_notifier(struct notifier_block * nb)
 526 {
 527         /* no events will happen anyway, so this can always succeed */
 528         return 0;
 529 }
 530
 531 static inline int unregister_module_notifier(struct notifier_block * nb)
 532 {
 533         return 0;
 534 }
 535
 536 #define module_put_and_exit(code) do_exit(code)
 537
 538 static inline void print_modules(void)
 539 {
 540 }
 541
 542 struct device_driver;
 543 struct module;
 544
 545 static inline void module_add_driver(struct module *module, struct device_driver *driver)
 546 {
 547 }
 548
 549 static inline void module_remove_driver(struct device_driver *driver)
 550 {
 551 }
 552
 553 #endif /* CONFIG_MODULES */
 554
 555 #define symbol_request(x) try_then_request_module(symbol_get(x), "symbol:" #x)
 556
 557 /* BELOW HERE ALL THESE ARE OBSOLETE AND WILL VANISH */
 558
 559 #define __MODULE_STRING(x) __stringify(x)
 560
 561 #endif /* _LINUX_MODULE_H */