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/tracepoint.h>
  19 #include <linux/export.h>
  20
  21 #include <linux/percpu.h>
  22 #include <asm/module.h>
  23
  24 #include <trace/events/module.h>
  25
  26 /* Not Yet Implemented */
  27 #define MODULE_SUPPORTED_DEVICE(name)
  28
  29 #define MODULE_NAME_LEN MAX_PARAM_PREFIX_LEN
  30
  31 struct modversion_info
  32 {
  33         unsigned long crc;
  34         char name[MODULE_NAME_LEN];
  35 };
  36
  37 struct module;
  38
  39 struct module_kobject {
  40         struct kobject kobj;
  41         struct module *mod;
  42         struct kobject *drivers_dir;
  43         struct module_param_attrs *mp;
  44 };
  45
  46 struct module_attribute {
  47         struct attribute attr;
  48         ssize_t (*show)(struct module_attribute *, struct module_kobject *,
  49                         char *);
  50         ssize_t (*store)(struct module_attribute *, struct module_kobject *,
  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_version_attribute {
  58         struct module_attribute mattr;
  59         const char *module_name;
  60         const char *version;
  61 } __attribute__ ((__aligned__(sizeof(void *))));
  62
  63 extern ssize_t __modver_version_show(struct module_attribute *,
  64                                      struct module_kobject *, char *);
  65
  66 extern struct module_attribute module_uevent;
  67
  68 /* These are either module local, or the kernel's dummy ones. */
  69 extern int init_module(void);
  70 extern void cleanup_module(void);
  71
  72 /* Archs provide a method of finding the correct exception table. */
  73 struct exception_table_entry;
  74
  75 const struct exception_table_entry *
  76 search_extable(const struct exception_table_entry *first,
  77                const struct exception_table_entry *last,
  78                unsigned long value);
  79 void sort_extable(struct exception_table_entry *start,
  80                   struct exception_table_entry *finish);
  81 void sort_main_extable(void);
  82 void trim_init_extable(struct module *m);
  83
  84 #ifdef MODULE
  85 #define MODULE_GENERIC_TABLE(gtype,name)                        \
  86 extern const struct gtype##_id __mod_##gtype##_table            \
  87   __attribute__ ((unused, alias(__stringify(name))))
  88
  89 #else  /* !MODULE */
  90 #define MODULE_GENERIC_TABLE(gtype,name)
  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 /*
 130  * Author(s), use "Name <email>" or just "Name", for multiple
 131  * authors use multiple MODULE_AUTHOR() statements/lines.
 132  */
 133 #define MODULE_AUTHOR(_author) MODULE_INFO(author, _author)
 134
 135 /* What your module does. */
 136 #define MODULE_DESCRIPTION(_description) MODULE_INFO(description, _description)
 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
 156 #if defined(MODULE) || !defined(CONFIG_SYSFS)
 157 #define MODULE_VERSION(_version) MODULE_INFO(version, _version)
 158 #else
 159 #define MODULE_VERSION(_version)                                        \
 160         static struct module_version_attribute ___modver_attr = {       \
 161                 .mattr  = {                                             \
 162                         .attr   = {                                     \
 163                                 .name   = "version",                    \
 164                                 .mode   = S_IRUGO,                      \
 165                         },                                              \
 166                         .show   = __modver_version_show,                \
 167                 },                                                      \
 168                 .module_name    = KBUILD_MODNAME,                       \
 169                 .version        = _version,                             \
 170         };                                                              \
 171         static const struct module_version_attribute                    \
 172         __used __attribute__ ((__section__ ("__modver")))               \
 173         * __moduleparam_const __modver_attr = &___modver_attr
 174 #endif
 175
 176 /* Optional firmware file (or files) needed by the module
 177  * format is simply firmware file name.  Multiple firmware
 178  * files require multiple MODULE_FIRMWARE() specifiers */
 179 #define MODULE_FIRMWARE(_firmware) MODULE_INFO(firmware, _firmware)
 180
 181 /* Given an address, look for it in the exception tables */
 182 const struct exception_table_entry *search_exception_tables(unsigned long add);
 183
 184 struct notifier_block;
 185
 186 #ifdef CONFIG_MODULES
 187
 188 extern int modules_disabled; /* for sysctl */
 189 /* Get/put a kernel symbol (calls must be symmetric) */
 190 void *__symbol_get(const char *symbol);
 191 void *__symbol_get_gpl(const char *symbol);
 192 #define symbol_get(x) ((typeof(&x))(__symbol_get(MODULE_SYMBOL_PREFIX #x)))
 193
 194 /* modules using other modules: kdb wants to see this. */
 195 struct module_use {
 196         struct list_head source_list;
 197         struct list_head target_list;
 198         struct module *source, *target;
 199 };
 200
 201 enum module_state
 202 {
 203         MODULE_STATE_LIVE,
 204         MODULE_STATE_COMING,
 205         MODULE_STATE_GOING,
 206 };
 207
 208 struct module
 209 {
 210         enum module_state state;
 211
 212         /* Member of list of modules */
 213         struct list_head list;
 214
 215         /* Unique handle for this module */
 216         char name[MODULE_NAME_LEN];
 217
 218         /* Sysfs stuff. */
 219         struct module_kobject mkobj;
 220         struct module_attribute *modinfo_attrs;
 221         const char *version;
 222         const char *srcversion;
 223         struct kobject *holders_dir;
 224
 225         /* Exported symbols */
 226         const struct kernel_symbol *syms;
 227         const unsigned long *crcs;
 228         unsigned int num_syms;
 229
 230         /* Kernel parameters. */
 231         struct kernel_param *kp;
 232         unsigned int num_kp;
 233
 234         /* GPL-only exported symbols. */
 235         unsigned int num_gpl_syms;
 236         const struct kernel_symbol *gpl_syms;
 237         const unsigned long *gpl_crcs;
 238
 239 #ifdef CONFIG_UNUSED_SYMBOLS
 240         /* unused exported symbols. */
 241         const struct kernel_symbol *unused_syms;
 242         const unsigned long *unused_crcs;
 243         unsigned int num_unused_syms;
 244
 245         /* GPL-only, unused exported symbols. */
 246         unsigned int num_unused_gpl_syms;
 247         const struct kernel_symbol *unused_gpl_syms;
 248         const unsigned long *unused_gpl_crcs;
 249 #endif
 250
 251         /* symbols that will be GPL-only in the near future. */
 252         const struct kernel_symbol *gpl_future_syms;
 253         const unsigned long *gpl_future_crcs;
 254         unsigned int num_gpl_future_syms;
 255
 256         /* Exception table */
 257         unsigned int num_exentries;
 258         struct exception_table_entry *extable;
 259
 260         /* Startup function. */
 261         int (*init)(void);
 262
 263         /* If this is non-NULL, vfree after init() returns */
 264         void *module_init;
 265
 266         /* Here is the actual code + data, vfree'd on unload. */
 267         void *module_core;
 268
 269         /* Here are the sizes of the init and core sections */
 270         unsigned int init_size, core_size;
 271
 272         /* The size of the executable code in each section.  */
 273         unsigned int init_text_size, core_text_size;
 274
 275         /* Size of RO sections of the module (text+rodata) */
 276         unsigned int init_ro_size, core_ro_size;
 277
 278         /* Arch-specific module values */
 279         struct mod_arch_specific arch;
 280
 281         unsigned int taints;    /* same bits as kernel:tainted */
 282
 283 #ifdef CONFIG_GENERIC_BUG
 284         /* Support for BUG */
 285         unsigned num_bugs;
 286         struct list_head bug_list;
 287         struct bug_entry *bug_table;
 288 #endif
 289
 290 #ifdef CONFIG_KALLSYMS
 291         /*
 292          * We keep the symbol and string tables for kallsyms.
 293          * The core_* fields below are temporary, loader-only (they
 294          * could really be discarded after module init).
 295          */
 296         Elf_Sym *symtab, *core_symtab;
 297         unsigned int num_symtab, core_num_syms;
 298         char *strtab, *core_strtab;
 299
 300         /* Section attributes */
 301         struct module_sect_attrs *sect_attrs;
 302
 303         /* Notes attributes */
 304         struct module_notes_attrs *notes_attrs;
 305 #endif
 306
 307         /* The command line arguments (may be mangled).  People like
 308            keeping pointers to this stuff */
 309         char *args;
 310
 311 #ifdef CONFIG_SMP
 312         /* Per-cpu data. */
 313         void __percpu *percpu;
 314         unsigned int percpu_size;
 315 #endif
 316
 317 #ifdef CONFIG_TRACEPOINTS
 318         unsigned int num_tracepoints;
 319         struct tracepoint * const *tracepoints_ptrs;
 320 #endif
 321 #ifdef HAVE_JUMP_LABEL
 322         struct jump_entry *jump_entries;
 323         unsigned int num_jump_entries;
 324 #endif
 325 #ifdef CONFIG_TRACING
 326         unsigned int num_trace_bprintk_fmt;
 327         const char **trace_bprintk_fmt_start;
 328 #endif
 329 #ifdef CONFIG_EVENT_TRACING
 330         struct ftrace_event_call **trace_events;
 331         unsigned int num_trace_events;
 332 #endif
 333 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
 334         unsigned int num_ftrace_callsites;
 335         unsigned long *ftrace_callsites;
 336 #endif
 337
 338 #ifdef CONFIG_MODULE_UNLOAD
 339         /* What modules depend on me? */
 340         struct list_head source_list;
 341         /* What modules do I depend on? */
 342         struct list_head target_list;
 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         struct module_ref {
 351                 unsigned int incs;
 352                 unsigned int decs;
 353         } __percpu *refptr;
 354 #endif
 355
 356 #ifdef CONFIG_CONSTRUCTORS
 357         /* Constructor functions. */
 358         ctor_fn_t *ctors;
 359         unsigned int num_ctors;
 360 #endif
 361 };
 362 #ifndef MODULE_ARCH_INIT
 363 #define MODULE_ARCH_INIT {}
 364 #endif
 365
 366 extern struct mutex module_mutex;
 367
 368 /* FIXME: It'd be nice to isolate modules during init, too, so they
 369    aren't used before they (may) fail.  But presently too much code
 370    (IDE & SCSI) require entry into the module during init.*/
 371 static inline int module_is_live(struct module *mod)
 372 {
 373         return mod->state != MODULE_STATE_GOING;
 374 }
 375
 376 struct module *__module_text_address(unsigned long addr);
 377 struct module *__module_address(unsigned long addr);
 378 bool is_module_address(unsigned long addr);
 379 bool is_module_percpu_address(unsigned long addr);
 380 bool is_module_text_address(unsigned long addr);
 381
 382 static inline int within_module_core(unsigned long addr, struct module *mod)
 383 {
 384         return (unsigned long)mod->module_core <= addr &&
 385                addr < (unsigned long)mod->module_core + mod->core_size;
 386 }
 387
 388 static inline int within_module_init(unsigned long addr, struct module *mod)
 389 {
 390         return (unsigned long)mod->module_init <= addr &&
 391                addr < (unsigned long)mod->module_init + mod->init_size;
 392 }
 393
 394 /* Search for module by name: must hold module_mutex. */
 395 struct module *find_module(const char *name);
 396
 397 struct symsearch {
 398         const struct kernel_symbol *start, *stop;
 399         const unsigned long *crcs;
 400         enum {
 401                 NOT_GPL_ONLY,
 402                 GPL_ONLY,
 403                 WILL_BE_GPL_ONLY,
 404         } licence;
 405         bool unused;
 406 };
 407
 408 /* Search for an exported symbol by name. */
 409 const struct kernel_symbol *find_symbol(const char *name,
 410                                         struct module **owner,
 411                                         const unsigned long **crc,
 412                                         bool gplok,
 413                                         bool warn);
 414
 415 /* Walk the exported symbol table */
 416 bool each_symbol_section(bool (*fn)(const struct symsearch *arr,
 417                                     struct module *owner,
 418                                     void *data), void *data);
 419
 420 /* Returns 0 and fills in value, defined and namebuf, or -ERANGE if
 421    symnum out of range. */
 422 int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
 423                         char *name, char *module_name, int *exported);
 424
 425 /* Look for this name: can be of form module:name. */
 426 unsigned long module_kallsyms_lookup_name(const char *name);
 427
 428 int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
 429                                              struct module *, unsigned long),
 430                                    void *data);
 431
 432 extern void __module_put_and_exit(struct module *mod, long code)
 433         __attribute__((noreturn));
 434 #define module_put_and_exit(code) __module_put_and_exit(THIS_MODULE, code);
 435
 436 #ifdef CONFIG_MODULE_UNLOAD
 437 unsigned int module_refcount(struct module *mod);
 438 void __symbol_put(const char *symbol);
 439 #define symbol_put(x) __symbol_put(MODULE_SYMBOL_PREFIX #x)
 440 void symbol_put_addr(void *addr);
 441
 442 /* Sometimes we know we already have a refcount, and it's easier not
 443    to handle the error case (which only happens with rmmod --wait). */
 444 static inline void __module_get(struct module *module)
 445 {
 446         if (module) {
 447                 preempt_disable();
 448                 __this_cpu_inc(module->refptr->incs);
 449                 trace_module_get(module, _THIS_IP_);
 450                 preempt_enable();
 451         }
 452 }
 453
 454 static inline int try_module_get(struct module *module)
 455 {
 456         int ret = 1;
 457
 458         if (module) {
 459                 preempt_disable();
 460
 461                 if (likely(module_is_live(module))) {
 462                         __this_cpu_inc(module->refptr->incs);
 463                         trace_module_get(module, _THIS_IP_);
 464                 } else
 465                         ret = 0;
 466
 467                 preempt_enable();
 468         }
 469         return ret;
 470 }
 471
 472 extern void module_put(struct module *module);
 473
 474 #else /*!CONFIG_MODULE_UNLOAD*/
 475 static inline int try_module_get(struct module *module)
 476 {
 477         return !module || module_is_live(module);
 478 }
 479 static inline void module_put(struct module *module)
 480 {
 481 }
 482 static inline void __module_get(struct module *module)
 483 {
 484 }
 485 #define symbol_put(x) do { } while(0)
 486 #define symbol_put_addr(p) do { } while(0)
 487
 488 #endif /* CONFIG_MODULE_UNLOAD */
 489 int ref_module(struct module *a, struct module *b);
 490
 491 /* This is a #define so the string doesn't get put in every .o file */
 492 #define module_name(mod)                        \
 493 ({                                              \
 494         struct module *__mod = (mod);           \
 495         __mod ? __mod->name : "kernel";         \
 496 })
 497
 498 /* For kallsyms to ask for address resolution.  namebuf should be at
 499  * least KSYM_NAME_LEN long: a pointer to namebuf is returned if
 500  * found, otherwise NULL. */
 501 const char *module_address_lookup(unsigned long addr,
 502                             unsigned long *symbolsize,
 503                             unsigned long *offset,
 504                             char **modname,
 505                             char *namebuf);
 506 int lookup_module_symbol_name(unsigned long addr, char *symname);
 507 int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name);
 508
 509 /* For extable.c to search modules' exception tables. */
 510 const struct exception_table_entry *search_module_extables(unsigned long addr);
 511
 512 int register_module_notifier(struct notifier_block * nb);
 513 int unregister_module_notifier(struct notifier_block * nb);
 514
 515 extern void print_modules(void);
 516
 517 #else /* !CONFIG_MODULES... */
 518
 519 /* Given an address, look for it in the exception tables. */
 520 static inline const struct exception_table_entry *
 521 search_module_extables(unsigned long addr)
 522 {
 523         return NULL;
 524 }
 525
 526 static inline struct module *__module_address(unsigned long addr)
 527 {
 528         return NULL;
 529 }
 530
 531 static inline struct module *__module_text_address(unsigned long addr)
 532 {
 533         return NULL;
 534 }
 535
 536 static inline bool is_module_address(unsigned long addr)
 537 {
 538         return false;
 539 }
 540
 541 static inline bool is_module_percpu_address(unsigned long addr)
 542 {
 543         return false;
 544 }
 545
 546 static inline bool is_module_text_address(unsigned long addr)
 547 {
 548         return false;
 549 }
 550
 551 /* Get/put a kernel symbol (calls should be symmetric) */
 552 #define symbol_get(x) ({ extern typeof(x) x __attribute__((weak)); &(x); })
 553 #define symbol_put(x) do { } while(0)
 554 #define symbol_put_addr(x) do { } while(0)
 555
 556 static inline void __module_get(struct module *module)
 557 {
 558 }
 559
 560 static inline int try_module_get(struct module *module)
 561 {
 562         return 1;
 563 }
 564
 565 static inline void module_put(struct module *module)
 566 {
 567 }
 568
 569 #define module_name(mod) "kernel"
 570
 571 /* For kallsyms to ask for address resolution.  NULL means not found. */
 572 static inline const char *module_address_lookup(unsigned long addr,
 573                                           unsigned long *symbolsize,
 574                                           unsigned long *offset,
 575                                           char **modname,
 576                                           char *namebuf)
 577 {
 578         return NULL;
 579 }
 580
 581 static inline int lookup_module_symbol_name(unsigned long addr, char *symname)
 582 {
 583         return -ERANGE;
 584 }
 585
 586 static inline int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name)
 587 {
 588         return -ERANGE;
 589 }
 590
 591 static inline int module_get_kallsym(unsigned int symnum, unsigned long *value,
 592                                         char *type, char *name,
 593                                         char *module_name, int *exported)
 594 {
 595         return -ERANGE;
 596 }
 597
 598 static inline unsigned long module_kallsyms_lookup_name(const char *name)
 599 {
 600         return 0;
 601 }
 602
 603 static inline int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
 604                                                            struct module *,
 605                                                            unsigned long),
 606                                                  void *data)
 607 {
 608         return 0;
 609 }
 610
 611 static inline int register_module_notifier(struct notifier_block * nb)
 612 {
 613         /* no events will happen anyway, so this can always succeed */
 614         return 0;
 615 }
 616
 617 static inline int unregister_module_notifier(struct notifier_block * nb)
 618 {
 619         return 0;
 620 }
 621
 622 #define module_put_and_exit(code) do_exit(code)
 623
 624 static inline void print_modules(void)
 625 {
 626 }
 627 #endif /* CONFIG_MODULES */
 628
 629 #ifdef CONFIG_SYSFS
 630 extern struct kset *module_kset;
 631 extern struct kobj_type module_ktype;
 632 extern int module_sysfs_initialized;
 633 #endif /* CONFIG_SYSFS */
 634
 635 #define symbol_request(x) try_then_request_module(symbol_get(x), "symbol:" #x)
 636
 637 /* BELOW HERE ALL THESE ARE OBSOLETE AND WILL VANISH */
 638
 639 #define __MODULE_STRING(x) __stringify(x)
 640
 641 #ifdef CONFIG_DEBUG_SET_MODULE_RONX
 642 extern void set_all_modules_text_rw(void);
 643 extern void set_all_modules_text_ro(void);
 644 #else
 645 static inline void set_all_modules_text_rw(void) { }
 646 static inline void set_all_modules_text_ro(void) { }
 647 #endif
 648
 649 #ifdef CONFIG_GENERIC_BUG
 650 void module_bug_finalize(const Elf_Ehdr *, const Elf_Shdr *,
 651                          struct module *);
 652 void module_bug_cleanup(struct module *);
 653
 654 #else   /* !CONFIG_GENERIC_BUG */
 655
 656 static inline void module_bug_finalize(const Elf_Ehdr *hdr,
 657                                         const Elf_Shdr *sechdrs,
 658                                         struct module *mod)
 659 {
 660 }
 661 static inline void module_bug_cleanup(struct module *mod) {}
 662 #endif  /* CONFIG_GENERIC_BUG */
 663
 664 #endif /* _LINUX_MODULE_H */