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 <linux/marker.h>
  19 #include <linux/tracepoint.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 /* some toolchains 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 MAX_PARAM_PREFIX_LEN
  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         struct kobject *drivers_dir;
  63         struct module_param_attrs *mp;
  64 };
  65
  66 /* These are either module local, or the kernel's dummy ones. */
  67 extern int init_module(void);
  68 extern void cleanup_module(void);
  69
  70 /* Archs provide a method of finding the correct exception table. */
  71 struct exception_table_entry;
  72
  73 const struct exception_table_entry *
  74 search_extable(const struct exception_table_entry *first,
  75                const struct exception_table_entry *last,
  76                unsigned long value);
  77 void sort_extable(struct exception_table_entry *start,
  78                   struct exception_table_entry *finish);
  79 void sort_main_extable(void);
  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[, NAME]*[ and NAME] */
 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 /* Optional firmware file (or files) needed by the module
 160  * format is simply firmware file name.  Multiple firmware
 161  * files require multiple MODULE_FIRMWARE() specifiers */
 162 #define MODULE_FIRMWARE(_firmware) MODULE_INFO(firmware, _firmware)
 163
 164 /* Given an address, look for it in the exception tables */
 165 const struct exception_table_entry *search_exception_tables(unsigned long add);
 166
 167 struct notifier_block;
 168
 169 #ifdef CONFIG_MODULES
 170
 171 /* Get/put a kernel symbol (calls must be symmetric) */
 172 void *__symbol_get(const char *symbol);
 173 void *__symbol_get_gpl(const char *symbol);
 174 #define symbol_get(x) ((typeof(&x))(__symbol_get(MODULE_SYMBOL_PREFIX #x)))
 175
 176 #ifndef __GENKSYMS__
 177 #ifdef CONFIG_MODVERSIONS
 178 /* Mark the CRC weak since genksyms apparently decides not to
 179  * generate a checksums for some symbols */
 180 #define __CRC_SYMBOL(sym, sec)                                  \
 181         extern void *__crc_##sym __attribute__((weak));         \
 182         static const unsigned long __kcrctab_##sym              \
 183         __used                                                  \
 184         __attribute__((section("__kcrctab" sec), unused))       \
 185         = (unsigned long) &__crc_##sym;
 186 #else
 187 #define __CRC_SYMBOL(sym, sec)
 188 #endif
 189
 190 /* For every exported symbol, place a struct in the __ksymtab section */
 191 #define __EXPORT_SYMBOL(sym, sec)                               \
 192         extern typeof(sym) sym;                                 \
 193         __CRC_SYMBOL(sym, sec)                                  \
 194         static const char __kstrtab_##sym[]                     \
 195         __attribute__((section("__ksymtab_strings"), aligned(1))) \
 196         = MODULE_SYMBOL_PREFIX #sym;                            \
 197         static const struct kernel_symbol __ksymtab_##sym       \
 198         __used                                                  \
 199         __attribute__((section("__ksymtab" sec), unused))       \
 200         = { (unsigned long)&sym, __kstrtab_##sym }
 201
 202 #define EXPORT_SYMBOL(sym)                                      \
 203         __EXPORT_SYMBOL(sym, "")
 204
 205 #define EXPORT_SYMBOL_GPL(sym)                                  \
 206         __EXPORT_SYMBOL(sym, "_gpl")
 207
 208 #define EXPORT_SYMBOL_GPL_FUTURE(sym)                           \
 209         __EXPORT_SYMBOL(sym, "_gpl_future")
 210
 211
 212 #ifdef CONFIG_UNUSED_SYMBOLS
 213 #define EXPORT_UNUSED_SYMBOL(sym) __EXPORT_SYMBOL(sym, "_unused")
 214 #define EXPORT_UNUSED_SYMBOL_GPL(sym) __EXPORT_SYMBOL(sym, "_unused_gpl")
 215 #else
 216 #define EXPORT_UNUSED_SYMBOL(sym)
 217 #define EXPORT_UNUSED_SYMBOL_GPL(sym)
 218 #endif
 219
 220 #endif
 221
 222 struct module_ref
 223 {
 224         local_t count;
 225 } ____cacheline_aligned;
 226
 227 enum module_state
 228 {
 229         MODULE_STATE_LIVE,
 230         MODULE_STATE_COMING,
 231         MODULE_STATE_GOING,
 232 };
 233
 234 struct module
 235 {
 236         enum module_state state;
 237
 238         /* Member of list of modules */
 239         struct list_head list;
 240
 241         /* Unique handle for this module */
 242         char name[MODULE_NAME_LEN];
 243
 244         /* Sysfs stuff. */
 245         struct module_kobject mkobj;
 246         struct module_attribute *modinfo_attrs;
 247         const char *version;
 248         const char *srcversion;
 249         struct kobject *holders_dir;
 250
 251         /* Exported symbols */
 252         const struct kernel_symbol *syms;
 253         const unsigned long *crcs;
 254         unsigned int num_syms;
 255
 256         /* GPL-only exported symbols. */
 257         unsigned int num_gpl_syms;
 258         const struct kernel_symbol *gpl_syms;
 259         const unsigned long *gpl_crcs;
 260
 261 #ifdef CONFIG_UNUSED_SYMBOLS
 262         /* unused exported symbols. */
 263         const struct kernel_symbol *unused_syms;
 264         const unsigned long *unused_crcs;
 265         unsigned int num_unused_syms;
 266
 267         /* GPL-only, unused exported symbols. */
 268         unsigned int num_unused_gpl_syms;
 269         const struct kernel_symbol *unused_gpl_syms;
 270         const unsigned long *unused_gpl_crcs;
 271 #endif
 272
 273         /* symbols that will be GPL-only in the near future. */
 274         const struct kernel_symbol *gpl_future_syms;
 275         const unsigned long *gpl_future_crcs;
 276         unsigned int num_gpl_future_syms;
 277
 278         /* Exception table */
 279         unsigned int num_exentries;
 280         struct exception_table_entry *extable;
 281
 282         /* Startup function. */
 283         int (*init)(void);
 284
 285         /* If this is non-NULL, vfree after init() returns */
 286         void *module_init;
 287
 288         /* Here is the actual code + data, vfree'd on unload. */
 289         void *module_core;
 290
 291         /* Here are the sizes of the init and core sections */
 292         unsigned int init_size, core_size;
 293
 294         /* The size of the executable code in each section.  */
 295         unsigned int init_text_size, core_text_size;
 296
 297         /* The handle returned from unwind_add_table. */
 298         void *unwind_info;
 299
 300         /* Arch-specific module values */
 301         struct mod_arch_specific arch;
 302
 303         unsigned int taints;    /* same bits as kernel:tainted */
 304
 305 #ifdef CONFIG_GENERIC_BUG
 306         /* Support for BUG */
 307         unsigned num_bugs;
 308         struct list_head bug_list;
 309         struct bug_entry *bug_table;
 310 #endif
 311
 312 #ifdef CONFIG_KALLSYMS
 313         /* We keep the symbol and string tables for kallsyms. */
 314         Elf_Sym *symtab;
 315         unsigned int num_symtab;
 316         char *strtab;
 317
 318         /* Section attributes */
 319         struct module_sect_attrs *sect_attrs;
 320
 321         /* Notes attributes */
 322         struct module_notes_attrs *notes_attrs;
 323 #endif
 324
 325         /* Per-cpu data. */
 326         void *percpu;
 327
 328         /* The command line arguments (may be mangled).  People like
 329            keeping pointers to this stuff */
 330         char *args;
 331 #ifdef CONFIG_MARKERS
 332         struct marker *markers;
 333         unsigned int num_markers;
 334 #endif
 335 #ifdef CONFIG_TRACEPOINTS
 336         struct tracepoint *tracepoints;
 337         unsigned int num_tracepoints;
 338 #endif
 339
 340 #ifdef CONFIG_MODULE_UNLOAD
 341         /* What modules depend on me? */
 342         struct list_head modules_which_use_me;
 343
 344         /* Who is waiting for us to be unloaded */
 345         struct task_struct *waiter;
 346
 347         /* Destruction function. */
 348         void (*exit)(void);
 349
 350         /* Reference counts */
 351         struct module_ref ref[NR_CPUS];
 352 #endif
 353 };
 354 #ifndef MODULE_ARCH_INIT
 355 #define MODULE_ARCH_INIT {}
 356 #endif
 357
 358 /* FIXME: It'd be nice to isolate modules during init, too, so they
 359    aren't used before they (may) fail.  But presently too much code
 360    (IDE & SCSI) require entry into the module during init.*/
 361 static inline int module_is_live(struct module *mod)
 362 {
 363         return mod->state != MODULE_STATE_GOING;
 364 }
 365
 366 /* Is this address in a module? (second is with no locks, for oops) */
 367 struct module *module_text_address(unsigned long addr);
 368 struct module *__module_text_address(unsigned long addr);
 369 int is_module_address(unsigned long addr);
 370
 371 /* Returns 0 and fills in value, defined and namebuf, or -ERANGE if
 372    symnum out of range. */
 373 int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
 374                         char *name, char *module_name, int *exported);
 375
 376 /* Look for this name: can be of form module:name. */
 377 unsigned long module_kallsyms_lookup_name(const char *name);
 378
 379 extern void __module_put_and_exit(struct module *mod, long code)
 380         __attribute__((noreturn));
 381 #define module_put_and_exit(code) __module_put_and_exit(THIS_MODULE, code);
 382
 383 #ifdef CONFIG_MODULE_UNLOAD
 384 unsigned int module_refcount(struct module *mod);
 385 void __symbol_put(const char *symbol);
 386 #define symbol_put(x) __symbol_put(MODULE_SYMBOL_PREFIX #x)
 387 void symbol_put_addr(void *addr);
 388
 389 /* Sometimes we know we already have a refcount, and it's easier not
 390    to handle the error case (which only happens with rmmod --wait). */
 391 static inline void __module_get(struct module *module)
 392 {
 393         if (module) {
 394                 BUG_ON(module_refcount(module) == 0);
 395                 local_inc(&module->ref[get_cpu()].count);
 396                 put_cpu();
 397         }
 398 }
 399
 400 static inline int try_module_get(struct module *module)
 401 {
 402         int ret = 1;
 403
 404         if (module) {
 405                 unsigned int cpu = get_cpu();
 406                 if (likely(module_is_live(module)))
 407                         local_inc(&module->ref[cpu].count);
 408                 else
 409                         ret = 0;
 410                 put_cpu();
 411         }
 412         return ret;
 413 }
 414
 415 extern void module_put(struct module *module);
 416
 417 #else /*!CONFIG_MODULE_UNLOAD*/
 418 static inline int try_module_get(struct module *module)
 419 {
 420         return !module || module_is_live(module);
 421 }
 422 static inline void module_put(struct module *module)
 423 {
 424 }
 425 static inline void __module_get(struct module *module)
 426 {
 427 }
 428 #define symbol_put(x) do { } while(0)
 429 #define symbol_put_addr(p) do { } while(0)
 430
 431 #endif /* CONFIG_MODULE_UNLOAD */
 432
 433 /* This is a #define so the string doesn't get put in every .o file */
 434 #define module_name(mod)                        \
 435 ({                                              \
 436         struct module *__mod = (mod);           \
 437         __mod ? __mod->name : "kernel";         \
 438 })
 439
 440 /* For kallsyms to ask for address resolution.  namebuf should be at
 441  * least KSYM_NAME_LEN long: a pointer to namebuf is returned if
 442  * found, otherwise NULL. */
 443 const char *module_address_lookup(unsigned long addr,
 444                             unsigned long *symbolsize,
 445                             unsigned long *offset,
 446                             char **modname,
 447                             char *namebuf);
 448 int lookup_module_symbol_name(unsigned long addr, char *symname);
 449 int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name);
 450
 451 /* For extable.c to search modules' exception tables. */
 452 const struct exception_table_entry *search_module_extables(unsigned long addr);
 453
 454 int register_module_notifier(struct notifier_block * nb);
 455 int unregister_module_notifier(struct notifier_block * nb);
 456
 457 extern void print_modules(void);
 458
 459 extern void module_update_markers(void);
 460
 461 extern void module_update_tracepoints(void);
 462 extern int module_get_iter_tracepoints(struct tracepoint_iter *iter);
 463
 464 #else /* !CONFIG_MODULES... */
 465 #define EXPORT_SYMBOL(sym)
 466 #define EXPORT_SYMBOL_GPL(sym)
 467 #define EXPORT_SYMBOL_GPL_FUTURE(sym)
 468 #define EXPORT_UNUSED_SYMBOL(sym)
 469 #define EXPORT_UNUSED_SYMBOL_GPL(sym)
 470
 471 /* Given an address, look for it in the exception tables. */
 472 static inline const struct exception_table_entry *
 473 search_module_extables(unsigned long addr)
 474 {
 475         return NULL;
 476 }
 477
 478 /* Is this address in a module? */
 479 static inline struct module *module_text_address(unsigned long addr)
 480 {
 481         return NULL;
 482 }
 483
 484 /* Is this address in a module? (don't take a lock, we're oopsing) */
 485 static inline struct module *__module_text_address(unsigned long addr)
 486 {
 487         return NULL;
 488 }
 489
 490 static inline int is_module_address(unsigned long addr)
 491 {
 492         return 0;
 493 }
 494
 495 /* Get/put a kernel symbol (calls should be symmetric) */
 496 #define symbol_get(x) ({ extern typeof(x) x __attribute__((weak)); &(x); })
 497 #define symbol_put(x) do { } while(0)
 498 #define symbol_put_addr(x) do { } while(0)
 499
 500 static inline void __module_get(struct module *module)
 501 {
 502 }
 503
 504 static inline int try_module_get(struct module *module)
 505 {
 506         return 1;
 507 }
 508
 509 static inline void module_put(struct module *module)
 510 {
 511 }
 512
 513 #define module_name(mod) "kernel"
 514
 515 /* For kallsyms to ask for address resolution.  NULL means not found. */
 516 static inline const char *module_address_lookup(unsigned long addr,
 517                                           unsigned long *symbolsize,
 518                                           unsigned long *offset,
 519                                           char **modname,
 520                                           char *namebuf)
 521 {
 522         return NULL;
 523 }
 524
 525 static inline int lookup_module_symbol_name(unsigned long addr, char *symname)
 526 {
 527         return -ERANGE;
 528 }
 529
 530 static inline int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name)
 531 {
 532         return -ERANGE;
 533 }
 534
 535 static inline int module_get_kallsym(unsigned int symnum, unsigned long *value,
 536                                         char *type, char *name,
 537                                         char *module_name, int *exported)
 538 {
 539         return -ERANGE;
 540 }
 541
 542 static inline unsigned long module_kallsyms_lookup_name(const char *name)
 543 {
 544         return 0;
 545 }
 546
 547 static inline int register_module_notifier(struct notifier_block * nb)
 548 {
 549         /* no events will happen anyway, so this can always succeed */
 550         return 0;
 551 }
 552
 553 static inline int unregister_module_notifier(struct notifier_block * nb)
 554 {
 555         return 0;
 556 }
 557
 558 #define module_put_and_exit(code) do_exit(code)
 559
 560 static inline void print_modules(void)
 561 {
 562 }
 563
 564 static inline void module_update_markers(void)
 565 {
 566 }
 567
 568 static inline void module_update_tracepoints(void)
 569 {
 570 }
 571
 572 static inline int module_get_iter_tracepoints(struct tracepoint_iter *iter)
 573 {
 574         return 0;
 575 }
 576
 577 #endif /* CONFIG_MODULES */
 578
 579 struct device_driver;
 580 #ifdef CONFIG_SYSFS
 581 struct module;
 582
 583 extern struct kset *module_kset;
 584 extern struct kobj_type module_ktype;
 585 extern int module_sysfs_initialized;
 586
 587 int mod_sysfs_init(struct module *mod);
 588 int mod_sysfs_setup(struct module *mod,
 589                            struct kernel_param *kparam,
 590                            unsigned int num_params);
 591 int module_add_modinfo_attrs(struct module *mod);
 592 void module_remove_modinfo_attrs(struct module *mod);
 593
 594 #else /* !CONFIG_SYSFS */
 595
 596 static inline int mod_sysfs_init(struct module *mod)
 597 {
 598         return 0;
 599 }
 600
 601 static inline int mod_sysfs_setup(struct module *mod,
 602                            struct kernel_param *kparam,
 603                            unsigned int num_params)
 604 {
 605         return 0;
 606 }
 607
 608 static inline int module_add_modinfo_attrs(struct module *mod)
 609 {
 610         return 0;
 611 }
 612
 613 static inline void module_remove_modinfo_attrs(struct module *mod)
 614 { }
 615
 616 #endif /* CONFIG_SYSFS */
 617
 618 #define symbol_request(x) try_then_request_module(symbol_get(x), "symbol:" #x)
 619
 620 /* BELOW HERE ALL THESE ARE OBSOLETE AND WILL VANISH */
 621
 622 #define __MODULE_STRING(x) __stringify(x)
 623
 624 #endif /* _LINUX_MODULE_H */