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 /* One for each parameter, describing how to use it.  Some files do
 139    multiple of these per line, so can't just use MODULE_INFO. */
 140 #define MODULE_PARM_DESC(_parm, desc) \
 141         __MODULE_INFO(parm, _parm, #_parm ":" desc)
 142
 143 #define MODULE_DEVICE_TABLE(type,name)          \
 144   MODULE_GENERIC_TABLE(type##_device,name)
 145
 146 /* Version of form [<epoch>:]<version>[-<extra-version>].
 147    Or for CVS/RCS ID version, everything but the number is stripped.
 148   <epoch>: A (small) unsigned integer which allows you to start versions
 149            anew. If not mentioned, it's zero.  eg. "2:1.0" is after
 150            "1:2.0".
 151   <version>: The <version> may contain only alphanumerics and the
 152            character `.'.  Ordered by numeric sort for numeric parts,
 153            ascii sort for ascii parts (as per RPM or DEB algorithm).
 154   <extraversion>: Like <version>, but inserted for local
 155            customizations, eg "rh3" or "rusty1".
 156
 157   Using this automatically adds a checksum of the .c files and the
 158   local headers in "srcversion".
 159 */
 160
 161 #if defined(MODULE) || !defined(CONFIG_SYSFS)
 162 #define MODULE_VERSION(_version) MODULE_INFO(version, _version)
 163 #else
 164 #define MODULE_VERSION(_version)                                        \
 165         static struct module_version_attribute ___modver_attr = {       \
 166                 .mattr  = {                                             \
 167                         .attr   = {                                     \
 168                                 .name   = "version",                    \
 169                                 .mode   = S_IRUGO,                      \
 170                         },                                              \
 171                         .show   = __modver_version_show,                \
 172                 },                                                      \
 173                 .module_name    = KBUILD_MODNAME,                       \
 174                 .version        = _version,                             \
 175         };                                                              \
 176         static const struct module_version_attribute                    \
 177         __used __attribute__ ((__section__ ("__modver")))               \
 178         * __moduleparam_const __modver_attr = &___modver_attr
 179 #endif
 180
 181 /* Optional firmware file (or files) needed by the module
 182  * format is simply firmware file name.  Multiple firmware
 183  * files require multiple MODULE_FIRMWARE() specifiers */
 184 #define MODULE_FIRMWARE(_firmware) MODULE_INFO(firmware, _firmware)
 185
 186 /* Given an address, look for it in the exception tables */
 187 const struct exception_table_entry *search_exception_tables(unsigned long add);
 188
 189 struct notifier_block;
 190
 191 #ifdef CONFIG_MODULES
 192
 193 extern int modules_disabled; /* for sysctl */
 194 /* Get/put a kernel symbol (calls must be symmetric) */
 195 void *__symbol_get(const char *symbol);
 196 void *__symbol_get_gpl(const char *symbol);
 197 #define symbol_get(x) ((typeof(&x))(__symbol_get(MODULE_SYMBOL_PREFIX #x)))
 198
 199 /* modules using other modules: kdb wants to see this. */
 200 struct module_use {
 201         struct list_head source_list;
 202         struct list_head target_list;
 203         struct module *source, *target;
 204 };
 205
 206 enum module_state
 207 {
 208         MODULE_STATE_LIVE,
 209         MODULE_STATE_COMING,
 210         MODULE_STATE_GOING,
 211 };
 212
 213 struct module
 214 {
 215         enum module_state state;
 216
 217         /* Member of list of modules */
 218         struct list_head list;
 219
 220         /* Unique handle for this module */
 221         char name[MODULE_NAME_LEN];
 222
 223         /* Sysfs stuff. */
 224         struct module_kobject mkobj;
 225         struct module_attribute *modinfo_attrs;
 226         const char *version;
 227         const char *srcversion;
 228         struct kobject *holders_dir;
 229
 230         /* Exported symbols */
 231         const struct kernel_symbol *syms;
 232         const unsigned long *crcs;
 233         unsigned int num_syms;
 234
 235         /* Kernel parameters. */
 236         struct kernel_param *kp;
 237         unsigned int num_kp;
 238
 239         /* GPL-only exported symbols. */
 240         unsigned int num_gpl_syms;
 241         const struct kernel_symbol *gpl_syms;
 242         const unsigned long *gpl_crcs;
 243
 244 #ifdef CONFIG_UNUSED_SYMBOLS
 245         /* unused exported symbols. */
 246         const struct kernel_symbol *unused_syms;
 247         const unsigned long *unused_crcs;
 248         unsigned int num_unused_syms;
 249
 250         /* GPL-only, unused exported symbols. */
 251         unsigned int num_unused_gpl_syms;
 252         const struct kernel_symbol *unused_gpl_syms;
 253         const unsigned long *unused_gpl_crcs;
 254 #endif
 255
 256         /* symbols that will be GPL-only in the near future. */
 257         const struct kernel_symbol *gpl_future_syms;
 258         const unsigned long *gpl_future_crcs;
 259         unsigned int num_gpl_future_syms;
 260
 261         /* Exception table */
 262         unsigned int num_exentries;
 263         struct exception_table_entry *extable;
 264
 265         /* Startup function. */
 266         int (*init)(void);
 267
 268         /* If this is non-NULL, vfree after init() returns */
 269         void *module_init;
 270
 271         /* Here is the actual code + data, vfree'd on unload. */
 272         void *module_core;
 273
 274         /* Here are the sizes of the init and core sections */
 275         unsigned int init_size, core_size;
 276
 277         /* The size of the executable code in each section.  */
 278         unsigned int init_text_size, core_text_size;
 279
 280         /* Size of RO sections of the module (text+rodata) */
 281         unsigned int init_ro_size, core_ro_size;
 282
 283         /* Arch-specific module values */
 284         struct mod_arch_specific arch;
 285
 286         unsigned int taints;    /* same bits as kernel:tainted */
 287
 288 #ifdef CONFIG_GENERIC_BUG
 289         /* Support for BUG */
 290         unsigned num_bugs;
 291         struct list_head bug_list;
 292         struct bug_entry *bug_table;
 293 #endif
 294
 295 #ifdef CONFIG_KALLSYMS
 296         /*
 297          * We keep the symbol and string tables for kallsyms.
 298          * The core_* fields below are temporary, loader-only (they
 299          * could really be discarded after module init).
 300          */
 301         Elf_Sym *symtab, *core_symtab;
 302         unsigned int num_symtab, core_num_syms;
 303         char *strtab, *core_strtab;
 304
 305         /* Section attributes */
 306         struct module_sect_attrs *sect_attrs;
 307
 308         /* Notes attributes */
 309         struct module_notes_attrs *notes_attrs;
 310 #endif
 311
 312         /* The command line arguments (may be mangled).  People like
 313            keeping pointers to this stuff */
 314         char *args;
 315
 316 #ifdef CONFIG_SMP
 317         /* Per-cpu data. */
 318         void __percpu *percpu;
 319         unsigned int percpu_size;
 320 #endif
 321
 322 #ifdef CONFIG_TRACEPOINTS
 323         unsigned int num_tracepoints;
 324         struct tracepoint * const *tracepoints_ptrs;
 325 #endif
 326 #ifdef HAVE_JUMP_LABEL
 327         struct jump_entry *jump_entries;
 328         unsigned int num_jump_entries;
 329 #endif
 330 #ifdef CONFIG_TRACING
 331         unsigned int num_trace_bprintk_fmt;
 332         const char **trace_bprintk_fmt_start;
 333 #endif
 334 #ifdef CONFIG_EVENT_TRACING
 335         struct ftrace_event_call **trace_events;
 336         unsigned int num_trace_events;
 337 #endif
 338 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
 339         unsigned int num_ftrace_callsites;
 340         unsigned long *ftrace_callsites;
 341 #endif
 342
 343 #ifdef CONFIG_MODULE_UNLOAD
 344         /* What modules depend on me? */
 345         struct list_head source_list;
 346         /* What modules do I depend on? */
 347         struct list_head target_list;
 348
 349         /* Who is waiting for us to be unloaded */
 350         struct task_struct *waiter;
 351
 352         /* Destruction function. */
 353         void (*exit)(void);
 354
 355         struct module_ref {
 356                 unsigned int incs;
 357                 unsigned int decs;
 358         } __percpu *refptr;
 359 #endif
 360
 361 #ifdef CONFIG_CONSTRUCTORS
 362         /* Constructor functions. */
 363         ctor_fn_t *ctors;
 364         unsigned int num_ctors;
 365 #endif
 366 };
 367 #ifndef MODULE_ARCH_INIT
 368 #define MODULE_ARCH_INIT {}
 369 #endif
 370
 371 extern struct mutex module_mutex;
 372
 373 /* FIXME: It'd be nice to isolate modules during init, too, so they
 374    aren't used before they (may) fail.  But presently too much code
 375    (IDE & SCSI) require entry into the module during init.*/
 376 static inline int module_is_live(struct module *mod)
 377 {
 378         return mod->state != MODULE_STATE_GOING;
 379 }
 380
 381 struct module *__module_text_address(unsigned long addr);
 382 struct module *__module_address(unsigned long addr);
 383 bool is_module_address(unsigned long addr);
 384 bool is_module_percpu_address(unsigned long addr);
 385 bool is_module_text_address(unsigned long addr);
 386
 387 static inline int within_module_core(unsigned long addr, struct module *mod)
 388 {
 389         return (unsigned long)mod->module_core <= addr &&
 390                addr < (unsigned long)mod->module_core + mod->core_size;
 391 }
 392
 393 static inline int within_module_init(unsigned long addr, struct module *mod)
 394 {
 395         return (unsigned long)mod->module_init <= addr &&
 396                addr < (unsigned long)mod->module_init + mod->init_size;
 397 }
 398
 399 /* Search for module by name: must hold module_mutex. */
 400 struct module *find_module(const char *name);
 401
 402 struct symsearch {
 403         const struct kernel_symbol *start, *stop;
 404         const unsigned long *crcs;
 405         enum {
 406                 NOT_GPL_ONLY,
 407                 GPL_ONLY,
 408                 WILL_BE_GPL_ONLY,
 409         } licence;
 410         bool unused;
 411 };
 412
 413 /* Search for an exported symbol by name. */
 414 const struct kernel_symbol *find_symbol(const char *name,
 415                                         struct module **owner,
 416                                         const unsigned long **crc,
 417                                         bool gplok,
 418                                         bool warn);
 419
 420 /* Walk the exported symbol table */
 421 bool each_symbol_section(bool (*fn)(const struct symsearch *arr,
 422                                     struct module *owner,
 423                                     void *data), void *data);
 424
 425 /* Returns 0 and fills in value, defined and namebuf, or -ERANGE if
 426    symnum out of range. */
 427 int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
 428                         char *name, char *module_name, int *exported);
 429
 430 /* Look for this name: can be of form module:name. */
 431 unsigned long module_kallsyms_lookup_name(const char *name);
 432
 433 int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
 434                                              struct module *, unsigned long),
 435                                    void *data);
 436
 437 extern void __module_put_and_exit(struct module *mod, long code)
 438         __attribute__((noreturn));
 439 #define module_put_and_exit(code) __module_put_and_exit(THIS_MODULE, code);
 440
 441 #ifdef CONFIG_MODULE_UNLOAD
 442 unsigned int module_refcount(struct module *mod);
 443 void __symbol_put(const char *symbol);
 444 #define symbol_put(x) __symbol_put(MODULE_SYMBOL_PREFIX #x)
 445 void symbol_put_addr(void *addr);
 446
 447 /* Sometimes we know we already have a refcount, and it's easier not
 448    to handle the error case (which only happens with rmmod --wait). */
 449 static inline void __module_get(struct module *module)
 450 {
 451         if (module) {
 452                 preempt_disable();
 453                 __this_cpu_inc(module->refptr->incs);
 454                 trace_module_get(module, _THIS_IP_);
 455                 preempt_enable();
 456         }
 457 }
 458
 459 static inline int try_module_get(struct module *module)
 460 {
 461         int ret = 1;
 462
 463         if (module) {
 464                 preempt_disable();
 465
 466                 if (likely(module_is_live(module))) {
 467                         __this_cpu_inc(module->refptr->incs);
 468                         trace_module_get(module, _THIS_IP_);
 469                 } else
 470                         ret = 0;
 471
 472                 preempt_enable();
 473         }
 474         return ret;
 475 }
 476
 477 extern void module_put(struct module *module);
 478
 479 #else /*!CONFIG_MODULE_UNLOAD*/
 480 static inline int try_module_get(struct module *module)
 481 {
 482         return !module || module_is_live(module);
 483 }
 484 static inline void module_put(struct module *module)
 485 {
 486 }
 487 static inline void __module_get(struct module *module)
 488 {
 489 }
 490 #define symbol_put(x) do { } while(0)
 491 #define symbol_put_addr(p) do { } while(0)
 492
 493 #endif /* CONFIG_MODULE_UNLOAD */
 494 int ref_module(struct module *a, struct module *b);
 495
 496 /* This is a #define so the string doesn't get put in every .o file */
 497 #define module_name(mod)                        \
 498 ({                                              \
 499         struct module *__mod = (mod);           \
 500         __mod ? __mod->name : "kernel";         \
 501 })
 502
 503 /* For kallsyms to ask for address resolution.  namebuf should be at
 504  * least KSYM_NAME_LEN long: a pointer to namebuf is returned if
 505  * found, otherwise NULL. */
 506 const char *module_address_lookup(unsigned long addr,
 507                             unsigned long *symbolsize,
 508                             unsigned long *offset,
 509                             char **modname,
 510                             char *namebuf);
 511 int lookup_module_symbol_name(unsigned long addr, char *symname);
 512 int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name);
 513
 514 /* For extable.c to search modules' exception tables. */
 515 const struct exception_table_entry *search_module_extables(unsigned long addr);
 516
 517 int register_module_notifier(struct notifier_block * nb);
 518 int unregister_module_notifier(struct notifier_block * nb);
 519
 520 extern void print_modules(void);
 521
 522 extern void module_update_tracepoints(void);
 523 extern int module_get_iter_tracepoints(struct tracepoint_iter *iter);
 524
 525 #else /* !CONFIG_MODULES... */
 526
 527 /* Given an address, look for it in the exception tables. */
 528 static inline const struct exception_table_entry *
 529 search_module_extables(unsigned long addr)
 530 {
 531         return NULL;
 532 }
 533
 534 static inline struct module *__module_address(unsigned long addr)
 535 {
 536         return NULL;
 537 }
 538
 539 static inline struct module *__module_text_address(unsigned long addr)
 540 {
 541         return NULL;
 542 }
 543
 544 static inline bool is_module_address(unsigned long addr)
 545 {
 546         return false;
 547 }
 548
 549 static inline bool is_module_percpu_address(unsigned long addr)
 550 {
 551         return false;
 552 }
 553
 554 static inline bool is_module_text_address(unsigned long addr)
 555 {
 556         return false;
 557 }
 558
 559 /* Get/put a kernel symbol (calls should be symmetric) */
 560 #define symbol_get(x) ({ extern typeof(x) x __attribute__((weak)); &(x); })
 561 #define symbol_put(x) do { } while(0)
 562 #define symbol_put_addr(x) do { } while(0)
 563
 564 static inline void __module_get(struct module *module)
 565 {
 566 }
 567
 568 static inline int try_module_get(struct module *module)
 569 {
 570         return 1;
 571 }
 572
 573 static inline void module_put(struct module *module)
 574 {
 575 }
 576
 577 #define module_name(mod) "kernel"
 578
 579 /* For kallsyms to ask for address resolution.  NULL means not found. */
 580 static inline const char *module_address_lookup(unsigned long addr,
 581                                           unsigned long *symbolsize,
 582                                           unsigned long *offset,
 583                                           char **modname,
 584                                           char *namebuf)
 585 {
 586         return NULL;
 587 }
 588
 589 static inline int lookup_module_symbol_name(unsigned long addr, char *symname)
 590 {
 591         return -ERANGE;
 592 }
 593
 594 static inline int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name)
 595 {
 596         return -ERANGE;
 597 }
 598
 599 static inline int module_get_kallsym(unsigned int symnum, unsigned long *value,
 600                                         char *type, char *name,
 601                                         char *module_name, int *exported)
 602 {
 603         return -ERANGE;
 604 }
 605
 606 static inline unsigned long module_kallsyms_lookup_name(const char *name)
 607 {
 608         return 0;
 609 }
 610
 611 static inline int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
 612                                                            struct module *,
 613                                                            unsigned long),
 614                                                  void *data)
 615 {
 616         return 0;
 617 }
 618
 619 static inline int register_module_notifier(struct notifier_block * nb)
 620 {
 621         /* no events will happen anyway, so this can always succeed */
 622         return 0;
 623 }
 624
 625 static inline int unregister_module_notifier(struct notifier_block * nb)
 626 {
 627         return 0;
 628 }
 629
 630 #define module_put_and_exit(code) do_exit(code)
 631
 632 static inline void print_modules(void)
 633 {
 634 }
 635
 636 static inline void module_update_tracepoints(void)
 637 {
 638 }
 639
 640 static inline int module_get_iter_tracepoints(struct tracepoint_iter *iter)
 641 {
 642         return 0;
 643 }
 644 #endif /* CONFIG_MODULES */
 645
 646 #ifdef CONFIG_SYSFS
 647 extern struct kset *module_kset;
 648 extern struct kobj_type module_ktype;
 649 extern int module_sysfs_initialized;
 650 #endif /* CONFIG_SYSFS */
 651
 652 #define symbol_request(x) try_then_request_module(symbol_get(x), "symbol:" #x)
 653
 654 /* BELOW HERE ALL THESE ARE OBSOLETE AND WILL VANISH */
 655
 656 #define __MODULE_STRING(x) __stringify(x)
 657
 658 #ifdef CONFIG_DEBUG_SET_MODULE_RONX
 659 extern void set_all_modules_text_rw(void);
 660 extern void set_all_modules_text_ro(void);
 661 #else
 662 static inline void set_all_modules_text_rw(void) { }
 663 static inline void set_all_modules_text_ro(void) { }
 664 #endif
 665
 666 #ifdef CONFIG_GENERIC_BUG
 667 void module_bug_finalize(const Elf_Ehdr *, const Elf_Shdr *,
 668                          struct module *);
 669 void module_bug_cleanup(struct module *);
 670
 671 #else   /* !CONFIG_GENERIC_BUG */
 672
 673 static inline void module_bug_finalize(const Elf_Ehdr *hdr,
 674                                         const Elf_Shdr *sechdrs,
 675                                         struct module *mod)
 676 {
 677 }
 678 static inline void module_bug_cleanup(struct module *mod) {}
 679 #endif  /* CONFIG_GENERIC_BUG */
 680
 681 #endif /* _LINUX_MODULE_H */