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 };
  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 extern struct subsystem module_subsys;
  79
  80 #ifdef MODULE
  81 #define MODULE_GENERIC_TABLE(gtype,name)                        \
  82 extern const struct gtype##_id __mod_##gtype##_table            \
  83   __attribute__ ((unused, alias(__stringify(name))))
  84
  85 extern struct module __this_module;
  86 #define THIS_MODULE (&__this_module)
  87 #else  /* !MODULE */
  88 #define MODULE_GENERIC_TABLE(gtype,name)
  89 #define THIS_MODULE ((struct module *)0)
  90 #endif
  91
  92 /* Generic info of form tag = "info" */
  93 #define MODULE_INFO(tag, info) __MODULE_INFO(tag, tag, info)
  94
  95 /* For userspace: you can also call me... */
  96 #define MODULE_ALIAS(_alias) MODULE_INFO(alias, _alias)
  97
  98 /*
  99  * The following license idents are currently accepted as indicating free
 100  * software modules
 101  *
 102  *      "GPL"                           [GNU Public License v2 or later]
 103  *      "GPL v2"                        [GNU Public License v2]
 104  *      "GPL and additional rights"     [GNU Public License v2 rights and more]
 105  *      "Dual BSD/GPL"                  [GNU Public License v2
 106  *                                       or BSD license choice]
 107  *      "Dual MIT/GPL"                  [GNU Public License v2
 108  *                                       or MIT 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 /* Optional firmware file (or files) needed by the module
 159  * format is simply firmware file name.  Multiple firmware
 160  * files require multiple MODULE_FIRMWARE() specifiers */
 161 #define MODULE_FIRMWARE(_firmware) MODULE_INFO(firmware, _firmware)
 162
 163 /* Given an address, look for it in the exception tables */
 164 const struct exception_table_entry *search_exception_tables(unsigned long add);
 165
 166 struct notifier_block;
 167
 168 #ifdef CONFIG_MODULES
 169
 170 /* Get/put a kernel symbol (calls must be symmetric) */
 171 void *__symbol_get(const char *symbol);
 172 void *__symbol_get_gpl(const char *symbol);
 173 #define symbol_get(x) ((typeof(&x))(__symbol_get(MODULE_SYMBOL_PREFIX #x)))
 174
 175 #ifndef __GENKSYMS__
 176 #ifdef CONFIG_MODVERSIONS
 177 /* Mark the CRC weak since genksyms apparently decides not to
 178  * generate a checksums for some symbols */
 179 #define __CRC_SYMBOL(sym, sec)                                  \
 180         extern void *__crc_##sym __attribute__((weak));         \
 181         static const unsigned long __kcrctab_##sym              \
 182         __attribute_used__                                      \
 183         __attribute__((section("__kcrctab" sec), unused))       \
 184         = (unsigned long) &__crc_##sym;
 185 #else
 186 #define __CRC_SYMBOL(sym, sec)
 187 #endif
 188
 189 /* For every exported symbol, place a struct in the __ksymtab section */
 190 #define __EXPORT_SYMBOL(sym, sec)                               \
 191         extern typeof(sym) sym;                                 \
 192         __CRC_SYMBOL(sym, sec)                                  \
 193         static const char __kstrtab_##sym[]                     \
 194         __attribute__((section("__ksymtab_strings")))           \
 195         = MODULE_SYMBOL_PREFIX #sym;                            \
 196         static const struct kernel_symbol __ksymtab_##sym       \
 197         __attribute_used__                                      \
 198         __attribute__((section("__ksymtab" sec), unused))       \
 199         = { (unsigned long)&sym, __kstrtab_##sym }
 200
 201 #define EXPORT_SYMBOL(sym)                                      \
 202         __EXPORT_SYMBOL(sym, "")
 203
 204 #define EXPORT_SYMBOL_GPL(sym)                                  \
 205         __EXPORT_SYMBOL(sym, "_gpl")
 206
 207 #define EXPORT_SYMBOL_GPL_FUTURE(sym)                           \
 208         __EXPORT_SYMBOL(sym, "_gpl_future")
 209
 210
 211 #ifdef CONFIG_UNUSED_SYMBOLS
 212 #define EXPORT_UNUSED_SYMBOL(sym) __EXPORT_SYMBOL(sym, "_unused")
 213 #define EXPORT_UNUSED_SYMBOL_GPL(sym) __EXPORT_SYMBOL(sym, "_unused_gpl")
 214 #else
 215 #define EXPORT_UNUSED_SYMBOL(sym)
 216 #define EXPORT_UNUSED_SYMBOL_GPL(sym)
 217 #endif
 218
 219 #endif
 220
 221 struct module_ref
 222 {
 223         local_t count;
 224 } ____cacheline_aligned;
 225
 226 enum module_state
 227 {
 228         MODULE_STATE_LIVE,
 229         MODULE_STATE_COMING,
 230         MODULE_STATE_GOING,
 231 };
 232
 233 /* Similar stuff for section attributes. */
 234 struct module_sect_attr
 235 {
 236         struct module_attribute mattr;
 237         char *name;
 238         unsigned long address;
 239 };
 240
 241 struct module_sect_attrs
 242 {
 243         struct attribute_group grp;
 244         int nsections;
 245         struct module_sect_attr attrs[0];
 246 };
 247
 248 struct module_param_attrs;
 249
 250 struct module
 251 {
 252         enum module_state state;
 253
 254         /* Member of list of modules */
 255         struct list_head list;
 256
 257         /* Unique handle for this module */
 258         char name[MODULE_NAME_LEN];
 259
 260         /* Sysfs stuff. */
 261         struct module_kobject mkobj;
 262         struct module_param_attrs *param_attrs;
 263         struct module_attribute *modinfo_attrs;
 264         const char *version;
 265         const char *srcversion;
 266         struct kobject *drivers_dir;
 267
 268         /* Exported symbols */
 269         const struct kernel_symbol *syms;
 270         unsigned int num_syms;
 271         const unsigned long *crcs;
 272
 273         /* GPL-only exported symbols. */
 274         const struct kernel_symbol *gpl_syms;
 275         unsigned int num_gpl_syms;
 276         const unsigned long *gpl_crcs;
 277
 278         /* unused exported symbols. */
 279         const struct kernel_symbol *unused_syms;
 280         unsigned int num_unused_syms;
 281         const unsigned long *unused_crcs;
 282         /* GPL-only, unused exported symbols. */
 283         const struct kernel_symbol *unused_gpl_syms;
 284         unsigned int num_unused_gpl_syms;
 285         const unsigned long *unused_gpl_crcs;
 286
 287         /* symbols that will be GPL-only in the near future. */
 288         const struct kernel_symbol *gpl_future_syms;
 289         unsigned int num_gpl_future_syms;
 290         const unsigned long *gpl_future_crcs;
 291
 292         /* Exception table */
 293         unsigned int num_exentries;
 294         const struct exception_table_entry *extable;
 295
 296         /* Startup function. */
 297         int (*init)(void);
 298
 299         /* If this is non-NULL, vfree after init() returns */
 300         void *module_init;
 301
 302         /* Here is the actual code + data, vfree'd on unload. */
 303         void *module_core;
 304
 305         /* Here are the sizes of the init and core sections */
 306         unsigned long init_size, core_size;
 307
 308         /* The size of the executable code in each section.  */
 309         unsigned long init_text_size, core_text_size;
 310
 311         /* The handle returned from unwind_add_table. */
 312         void *unwind_info;
 313
 314         /* Arch-specific module values */
 315         struct mod_arch_specific arch;
 316
 317         /* Am I unsafe to unload? */
 318         int unsafe;
 319
 320         unsigned int taints;    /* same bits as kernel:tainted */
 321
 322 #ifdef CONFIG_MODULE_UNLOAD
 323         /* Reference counts */
 324         struct module_ref ref[NR_CPUS];
 325
 326         /* What modules depend on me? */
 327         struct list_head modules_which_use_me;
 328
 329         /* Who is waiting for us to be unloaded */
 330         struct task_struct *waiter;
 331
 332         /* Destruction function. */
 333         void (*exit)(void);
 334 #endif
 335
 336 #ifdef CONFIG_KALLSYMS
 337         /* We keep the symbol and string tables for kallsyms. */
 338         Elf_Sym *symtab;
 339         unsigned long num_symtab;
 340         char *strtab;
 341
 342         /* Section attributes */
 343         struct module_sect_attrs *sect_attrs;
 344 #endif
 345
 346         /* Per-cpu data. */
 347         void *percpu;
 348
 349         /* The command line arguments (may be mangled).  People like
 350            keeping pointers to this stuff */
 351         char *args;
 352 };
 353
 354 /* FIXME: It'd be nice to isolate modules during init, too, so they
 355    aren't used before they (may) fail.  But presently too much code
 356    (IDE & SCSI) require entry into the module during init.*/
 357 static inline int module_is_live(struct module *mod)
 358 {
 359         return mod->state != MODULE_STATE_GOING;
 360 }
 361
 362 /* Is this address in a module? (second is with no locks, for oops) */
 363 struct module *module_text_address(unsigned long addr);
 364 struct module *__module_text_address(unsigned long addr);
 365 int is_module_address(unsigned long addr);
 366
 367 /* Returns module and fills in value, defined and namebuf, or NULL if
 368    symnum out of range. */
 369 struct module *module_get_kallsym(unsigned int symnum, unsigned long *value,
 370                                 char *type, char *name, size_t namelen);
 371
 372 /* Look for this name: can be of form module:name. */
 373 unsigned long module_kallsyms_lookup_name(const char *name);
 374
 375 int is_exported(const char *name, const struct module *mod);
 376
 377 extern void __module_put_and_exit(struct module *mod, long code)
 378         __attribute__((noreturn));
 379 #define module_put_and_exit(code) __module_put_and_exit(THIS_MODULE, code);
 380
 381 #ifdef CONFIG_MODULE_UNLOAD
 382 unsigned int module_refcount(struct module *mod);
 383 void __symbol_put(const char *symbol);
 384 #define symbol_put(x) __symbol_put(MODULE_SYMBOL_PREFIX #x)
 385 void symbol_put_addr(void *addr);
 386
 387 /* Sometimes we know we already have a refcount, and it's easier not
 388    to handle the error case (which only happens with rmmod --wait). */
 389 static inline void __module_get(struct module *module)
 390 {
 391         if (module) {
 392                 BUG_ON(module_refcount(module) == 0);
 393                 local_inc(&module->ref[get_cpu()].count);
 394                 put_cpu();
 395         }
 396 }
 397
 398 static inline int try_module_get(struct module *module)
 399 {
 400         int ret = 1;
 401
 402         if (module) {
 403                 unsigned int cpu = get_cpu();
 404                 if (likely(module_is_live(module)))
 405                         local_inc(&module->ref[cpu].count);
 406                 else
 407                         ret = 0;
 408                 put_cpu();
 409         }
 410         return ret;
 411 }
 412
 413 extern void module_put(struct module *module);
 414
 415 #else /*!CONFIG_MODULE_UNLOAD*/
 416 static inline int try_module_get(struct module *module)
 417 {
 418         return !module || module_is_live(module);
 419 }
 420 static inline void module_put(struct module *module)
 421 {
 422 }
 423 static inline void __module_get(struct module *module)
 424 {
 425 }
 426 #define symbol_put(x) do { } while(0)
 427 #define symbol_put_addr(p) do { } while(0)
 428
 429 #endif /* CONFIG_MODULE_UNLOAD */
 430
 431 /* This is a #define so the string doesn't get put in every .o file */
 432 #define module_name(mod)                        \
 433 ({                                              \
 434         struct module *__mod = (mod);           \
 435         __mod ? __mod->name : "kernel";         \
 436 })
 437
 438 #define __unsafe(mod)                                                        \
 439 do {                                                                         \
 440         if (mod && !(mod)->unsafe) {                                         \
 441                 printk(KERN_WARNING                                          \
 442                        "Module %s cannot be unloaded due to unsafe usage in" \
 443                        " %s:%u\n", (mod)->name, __FILE__, __LINE__);         \
 444                 (mod)->unsafe = 1;                                           \
 445         }                                                                    \
 446 } while(0)
 447
 448 /* For kallsyms to ask for address resolution.  NULL means not found. */
 449 const char *module_address_lookup(unsigned long addr,
 450                                   unsigned long *symbolsize,
 451                                   unsigned long *offset,
 452                                   char **modname);
 453
 454 /* For extable.c to search modules' exception tables. */
 455 const struct exception_table_entry *search_module_extables(unsigned long addr);
 456
 457 int register_module_notifier(struct notifier_block * nb);
 458 int unregister_module_notifier(struct notifier_block * nb);
 459
 460 extern void print_modules(void);
 461
 462 struct device_driver;
 463 void module_add_driver(struct module *, struct device_driver *);
 464 void module_remove_driver(struct device_driver *);
 465
 466 #else /* !CONFIG_MODULES... */
 467 #define EXPORT_SYMBOL(sym)
 468 #define EXPORT_SYMBOL_GPL(sym)
 469 #define EXPORT_SYMBOL_GPL_FUTURE(sym)
 470 #define EXPORT_UNUSED_SYMBOL(sym)
 471 #define EXPORT_UNUSED_SYMBOL_GPL(sym)
 472
 473 /* Given an address, look for it in the exception tables. */
 474 static inline const struct exception_table_entry *
 475 search_module_extables(unsigned long addr)
 476 {
 477         return NULL;
 478 }
 479
 480 /* Is this address in a module? */
 481 static inline struct module *module_text_address(unsigned long addr)
 482 {
 483         return NULL;
 484 }
 485
 486 /* Is this address in a module? (don't take a lock, we're oopsing) */
 487 static inline struct module *__module_text_address(unsigned long addr)
 488 {
 489         return NULL;
 490 }
 491
 492 static inline int is_module_address(unsigned long addr)
 493 {
 494         return 0;
 495 }
 496
 497 /* Get/put a kernel symbol (calls should be symmetric) */
 498 #define symbol_get(x) ({ extern typeof(x) x __attribute__((weak)); &(x); })
 499 #define symbol_put(x) do { } while(0)
 500 #define symbol_put_addr(x) do { } while(0)
 501
 502 static inline void __module_get(struct module *module)
 503 {
 504 }
 505
 506 static inline int try_module_get(struct module *module)
 507 {
 508         return 1;
 509 }
 510
 511 static inline void module_put(struct module *module)
 512 {
 513 }
 514
 515 #define module_name(mod) "kernel"
 516
 517 #define __unsafe(mod)
 518
 519 /* For kallsyms to ask for address resolution.  NULL means not found. */
 520 static inline const char *module_address_lookup(unsigned long addr,
 521                                                 unsigned long *symbolsize,
 522                                                 unsigned long *offset,
 523                                                 char **modname)
 524 {
 525         return NULL;
 526 }
 527
 528 static inline struct module *module_get_kallsym(unsigned int symnum,
 529                                                 unsigned long *value,
 530                                                 char *type, char *name,
 531                                                 size_t namelen)
 532 {
 533         return NULL;
 534 }
 535
 536 static inline unsigned long module_kallsyms_lookup_name(const char *name)
 537 {
 538         return 0;
 539 }
 540
 541 static inline int is_exported(const char *name, const struct module *mod)
 542 {
 543         return 0;
 544 }
 545
 546 static inline int register_module_notifier(struct notifier_block * nb)
 547 {
 548         /* no events will happen anyway, so this can always succeed */
 549         return 0;
 550 }
 551
 552 static inline int unregister_module_notifier(struct notifier_block * nb)
 553 {
 554         return 0;
 555 }
 556
 557 #define module_put_and_exit(code) do_exit(code)
 558
 559 static inline void print_modules(void)
 560 {
 561 }
 562
 563 struct device_driver;
 564 struct module;
 565
 566 static inline void module_add_driver(struct module *module, struct device_driver *driver)
 567 {
 568 }
 569
 570 static inline void module_remove_driver(struct device_driver *driver)
 571 {
 572 }
 573
 574 #endif /* CONFIG_MODULES */
 575
 576 #define symbol_request(x) try_then_request_module(symbol_get(x), "symbol:" #x)
 577
 578 /* BELOW HERE ALL THESE ARE OBSOLETE AND WILL VANISH */
 579
 580 #define __MODULE_STRING(x) __stringify(x)
 581
 582 #endif /* _LINUX_MODULE_H */