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/jump_label.h>
  19 #include <linux/export.h>
  20
  21 #include <linux/percpu.h>
  22 #include <asm/module.h>
  23
  24 /* In stripped ARM and x86-64 modules, ~ is surprisingly rare. */
  25 #define MODULE_SIG_STRING "~Module signature appended~\n"
  26
  27 /* Not Yet Implemented */
  28 #define MODULE_SUPPORTED_DEVICE(name)
  29
  30 #define MODULE_NAME_LEN MAX_PARAM_PREFIX_LEN
  31
  32 struct modversion_info {
  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         struct completion *kobj_completion;
  45 };
  46
  47 struct module_attribute {
  48         struct attribute attr;
  49         ssize_t (*show)(struct module_attribute *, struct module_kobject *,
  50                         char *);
  51         ssize_t (*store)(struct module_attribute *, struct module_kobject *,
  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_version_attribute {
  59         struct module_attribute mattr;
  60         const char *module_name;
  61         const char *version;
  62 } __attribute__ ((__aligned__(sizeof(void *))));
  63
  64 extern ssize_t __modver_version_show(struct module_attribute *,
  65                                      struct module_kobject *, char *);
  66
  67 extern struct module_attribute module_uevent;
  68
  69 /* These are either module local, or the kernel's dummy ones. */
  70 extern int init_module(void);
  71 extern void cleanup_module(void);
  72
  73 /* Archs provide a method of finding the correct exception table. */
  74 struct exception_table_entry;
  75
  76 const struct exception_table_entry *
  77 search_extable(const struct exception_table_entry *first,
  78                const struct exception_table_entry *last,
  79                unsigned long value);
  80 void sort_extable(struct exception_table_entry *start,
  81                   struct exception_table_entry *finish);
  82 void sort_main_extable(void);
  83 void trim_init_extable(struct module *m);
  84
  85 /* Generic info of form tag = "info" */
  86 #define MODULE_INFO(tag, info) __MODULE_INFO(tag, tag, info)
  87
  88 /* For userspace: you can also call me... */
  89 #define MODULE_ALIAS(_alias) MODULE_INFO(alias, _alias)
  90
  91 /* Soft module dependencies. See man modprobe.d for details.
  92  * Example: MODULE_SOFTDEP("pre: module-foo module-bar post: module-baz")
  93  */
  94 #define MODULE_SOFTDEP(_softdep) MODULE_INFO(softdep, _softdep)
  95
  96 /*
  97  * The following license idents are currently accepted as indicating free
  98  * software modules
  99  *
 100  *      "GPL"                           [GNU Public License v2 or later]
 101  *      "GPL v2"                        [GNU Public License v2]
 102  *      "GPL and additional rights"     [GNU Public License v2 rights and more]
 103  *      "Dual BSD/GPL"                  [GNU Public License v2
 104  *                                       or BSD license choice]
 105  *      "Dual MIT/GPL"                  [GNU Public License v2
 106  *                                       or MIT license choice]
 107  *      "Dual MPL/GPL"                  [GNU Public License v2
 108  *                                       or Mozilla license choice]
 109  *
 110  * The following other idents are available
 111  *
 112  *      "Proprietary"                   [Non free products]
 113  *
 114  * There are dual licensed components, but when running with Linux it is the
 115  * GPL that is relevant so this is a non issue. Similarly LGPL linked with GPL
 116  * is a GPL combined work.
 117  *
 118  * This exists for several reasons
 119  * 1.   So modinfo can show license info for users wanting to vet their setup
 120  *      is free
 121  * 2.   So the community can ignore bug reports including proprietary modules
 122  * 3.   So vendors can do likewise based on their own policies
 123  */
 124 #define MODULE_LICENSE(_license) MODULE_INFO(license, _license)
 125
 126 /*
 127  * Author(s), use "Name <email>" or just "Name", for multiple
 128  * authors use multiple MODULE_AUTHOR() statements/lines.
 129  */
 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 #ifdef MODULE
 136 /* Creates an alias so file2alias.c can find device table. */
 137 #define MODULE_DEVICE_TABLE(type, name)                                 \
 138 extern const typeof(name) __mod_##type##__##name##_device_table         \
 139   __attribute__ ((unused, alias(__stringify(name))))
 140 #else  /* !MODULE */
 141 #define MODULE_DEVICE_TABLE(type, name)
 142 #endif
 143
 144 /* Version of form [<epoch>:]<version>[-<extra-version>].
 145  * Or for CVS/RCS ID version, everything but the number is stripped.
 146  * <epoch>: A (small) unsigned integer which allows you to start versions
 147  * anew. If not mentioned, it's zero.  eg. "2:1.0" is after
 148  * "1:2.0".
 149
 150  * <version>: The <version> may contain only alphanumerics and the
 151  * character `.'.  Ordered by numeric sort for numeric parts,
 152  * ascii sort for ascii parts (as per RPM or DEB algorithm).
 153
 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(VMLINUX_SYMBOL_STR(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         MODULE_STATE_LIVE,      /* Normal state. */
 208         MODULE_STATE_COMING,    /* Full formed, running module_init. */
 209         MODULE_STATE_GOING,     /* Going away. */
 210         MODULE_STATE_UNFORMED,  /* Still setting it up. */
 211 };
 212
 213 struct module {
 214         enum module_state state;
 215
 216         /* Member of list of modules */
 217         struct list_head list;
 218
 219         /* Unique handle for this module */
 220         char name[MODULE_NAME_LEN];
 221
 222         /* Sysfs stuff. */
 223         struct module_kobject mkobj;
 224         struct module_attribute *modinfo_attrs;
 225         const char *version;
 226         const char *srcversion;
 227         struct kobject *holders_dir;
 228
 229         /* Exported symbols */
 230         const struct kernel_symbol *syms;
 231         const unsigned long *crcs;
 232         unsigned int num_syms;
 233
 234         /* Kernel parameters. */
 235         struct kernel_param *kp;
 236         unsigned int num_kp;
 237
 238         /* GPL-only exported symbols. */
 239         unsigned int num_gpl_syms;
 240         const struct kernel_symbol *gpl_syms;
 241         const unsigned long *gpl_crcs;
 242
 243 #ifdef CONFIG_UNUSED_SYMBOLS
 244         /* unused exported symbols. */
 245         const struct kernel_symbol *unused_syms;
 246         const unsigned long *unused_crcs;
 247         unsigned int num_unused_syms;
 248
 249         /* GPL-only, unused exported symbols. */
 250         unsigned int num_unused_gpl_syms;
 251         const struct kernel_symbol *unused_gpl_syms;
 252         const unsigned long *unused_gpl_crcs;
 253 #endif
 254
 255 #ifdef CONFIG_MODULE_SIG
 256         /* Signature was verified. */
 257         bool sig_ok;
 258 #endif
 259
 260         /* symbols that will be GPL-only in the near future. */
 261         const struct kernel_symbol *gpl_future_syms;
 262         const unsigned long *gpl_future_crcs;
 263         unsigned int num_gpl_future_syms;
 264
 265         /* Exception table */
 266         unsigned int num_exentries;
 267         struct exception_table_entry *extable;
 268
 269         /* Startup function. */
 270         int (*init)(void);
 271
 272         /* If this is non-NULL, vfree after init() returns */
 273         void *module_init;
 274
 275         /* Here is the actual code + data, vfree'd on unload. */
 276         void *module_core;
 277
 278         /* Here are the sizes of the init and core sections */
 279         unsigned int init_size, core_size;
 280
 281         /* The size of the executable code in each section.  */
 282         unsigned int init_text_size, core_text_size;
 283
 284         /* Size of RO sections of the module (text+rodata) */
 285         unsigned int init_ro_size, core_ro_size;
 286
 287         /* Arch-specific module values */
 288         struct mod_arch_specific arch;
 289
 290         unsigned int taints;    /* same bits as kernel:tainted */
 291
 292 #ifdef CONFIG_GENERIC_BUG
 293         /* Support for BUG */
 294         unsigned num_bugs;
 295         struct list_head bug_list;
 296         struct bug_entry *bug_table;
 297 #endif
 298
 299 #ifdef CONFIG_KALLSYMS
 300         /*
 301          * We keep the symbol and string tables for kallsyms.
 302          * The core_* fields below are temporary, loader-only (they
 303          * could really be discarded after module init).
 304          */
 305         Elf_Sym *symtab, *core_symtab;
 306         unsigned int num_symtab, core_num_syms;
 307         char *strtab, *core_strtab;
 308
 309         /* Section attributes */
 310         struct module_sect_attrs *sect_attrs;
 311
 312         /* Notes attributes */
 313         struct module_notes_attrs *notes_attrs;
 314 #endif
 315
 316         /* The command line arguments (may be mangled).  People like
 317            keeping pointers to this stuff */
 318         char *args;
 319
 320 #ifdef CONFIG_SMP
 321         /* Per-cpu data. */
 322         void __percpu *percpu;
 323         unsigned int percpu_size;
 324 #endif
 325
 326 #ifdef CONFIG_TRACEPOINTS
 327         unsigned int num_tracepoints;
 328         struct tracepoint * const *tracepoints_ptrs;
 329 #endif
 330 #ifdef HAVE_JUMP_LABEL
 331         struct jump_entry *jump_entries;
 332         unsigned int num_jump_entries;
 333 #endif
 334 #ifdef CONFIG_TRACING
 335         unsigned int num_trace_bprintk_fmt;
 336         const char **trace_bprintk_fmt_start;
 337 #endif
 338 #ifdef CONFIG_EVENT_TRACING
 339         struct ftrace_event_call **trace_events;
 340         unsigned int num_trace_events;
 341         struct trace_enum_map **trace_enums;
 342         unsigned int num_trace_enums;
 343 #endif
 344 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
 345         unsigned int num_ftrace_callsites;
 346         unsigned long *ftrace_callsites;
 347 #endif
 348
 349 #ifdef CONFIG_LIVEPATCH
 350         bool klp_alive;
 351 #endif
 352
 353 #ifdef CONFIG_MODULE_UNLOAD
 354         /* What modules depend on me? */
 355         struct list_head source_list;
 356         /* What modules do I depend on? */
 357         struct list_head target_list;
 358
 359         /* Destruction function. */
 360         void (*exit)(void);
 361
 362         atomic_t refcnt;
 363 #endif
 364
 365 #ifdef CONFIG_CONSTRUCTORS
 366         /* Constructor functions. */
 367         ctor_fn_t *ctors;
 368         unsigned int num_ctors;
 369 #endif
 370 };
 371 #ifndef MODULE_ARCH_INIT
 372 #define MODULE_ARCH_INIT {}
 373 #endif
 374
 375 extern struct mutex module_mutex;
 376
 377 /* FIXME: It'd be nice to isolate modules during init, too, so they
 378    aren't used before they (may) fail.  But presently too much code
 379    (IDE & SCSI) require entry into the module during init.*/
 380 static inline int module_is_live(struct module *mod)
 381 {
 382         return mod->state != MODULE_STATE_GOING;
 383 }
 384
 385 struct module *__module_text_address(unsigned long addr);
 386 struct module *__module_address(unsigned long addr);
 387 bool is_module_address(unsigned long addr);
 388 bool is_module_percpu_address(unsigned long addr);
 389 bool is_module_text_address(unsigned long addr);
 390
 391 static inline bool within_module_core(unsigned long addr,
 392                                       const struct module *mod)
 393 {
 394         return (unsigned long)mod->module_core <= addr &&
 395                addr < (unsigned long)mod->module_core + mod->core_size;
 396 }
 397
 398 static inline bool within_module_init(unsigned long addr,
 399                                       const struct module *mod)
 400 {
 401         return (unsigned long)mod->module_init <= addr &&
 402                addr < (unsigned long)mod->module_init + mod->init_size;
 403 }
 404
 405 static inline bool within_module(unsigned long addr, const struct module *mod)
 406 {
 407         return within_module_init(addr, mod) || within_module_core(addr, mod);
 408 }
 409
 410 /* Search for module by name: must hold module_mutex. */
 411 struct module *find_module(const char *name);
 412
 413 struct symsearch {
 414         const struct kernel_symbol *start, *stop;
 415         const unsigned long *crcs;
 416         enum {
 417                 NOT_GPL_ONLY,
 418                 GPL_ONLY,
 419                 WILL_BE_GPL_ONLY,
 420         } licence;
 421         bool unused;
 422 };
 423
 424 /* Search for an exported symbol by name. */
 425 const struct kernel_symbol *find_symbol(const char *name,
 426                                         struct module **owner,
 427                                         const unsigned long **crc,
 428                                         bool gplok,
 429                                         bool warn);
 430
 431 /* Walk the exported symbol table */
 432 bool each_symbol_section(bool (*fn)(const struct symsearch *arr,
 433                                     struct module *owner,
 434                                     void *data), void *data);
 435
 436 /* Returns 0 and fills in value, defined and namebuf, or -ERANGE if
 437    symnum out of range. */
 438 int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
 439                         char *name, char *module_name, int *exported);
 440
 441 /* Look for this name: can be of form module:name. */
 442 unsigned long module_kallsyms_lookup_name(const char *name);
 443
 444 int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
 445                                              struct module *, unsigned long),
 446                                    void *data);
 447
 448 extern void __module_put_and_exit(struct module *mod, long code)
 449         __attribute__((noreturn));
 450 #define module_put_and_exit(code) __module_put_and_exit(THIS_MODULE, code)
 451
 452 #ifdef CONFIG_MODULE_UNLOAD
 453 int module_refcount(struct module *mod);
 454 void __symbol_put(const char *symbol);
 455 #define symbol_put(x) __symbol_put(VMLINUX_SYMBOL_STR(x))
 456 void symbol_put_addr(void *addr);
 457
 458 /* Sometimes we know we already have a refcount, and it's easier not
 459    to handle the error case (which only happens with rmmod --wait). */
 460 extern void __module_get(struct module *module);
 461
 462 /* This is the Right Way to get a module: if it fails, it's being removed,
 463  * so pretend it's not there. */
 464 extern bool try_module_get(struct module *module);
 465
 466 extern void module_put(struct module *module);
 467
 468 #else /*!CONFIG_MODULE_UNLOAD*/
 469 static inline int try_module_get(struct module *module)
 470 {
 471         return !module || module_is_live(module);
 472 }
 473 static inline void module_put(struct module *module)
 474 {
 475 }
 476 static inline void __module_get(struct module *module)
 477 {
 478 }
 479 #define symbol_put(x) do { } while (0)
 480 #define symbol_put_addr(p) do { } while (0)
 481
 482 #endif /* CONFIG_MODULE_UNLOAD */
 483 int ref_module(struct module *a, struct module *b);
 484
 485 /* This is a #define so the string doesn't get put in every .o file */
 486 #define module_name(mod)                        \
 487 ({                                              \
 488         struct module *__mod = (mod);           \
 489         __mod ? __mod->name : "kernel";         \
 490 })
 491
 492 /* For kallsyms to ask for address resolution.  namebuf should be at
 493  * least KSYM_NAME_LEN long: a pointer to namebuf is returned if
 494  * found, otherwise NULL. */
 495 const char *module_address_lookup(unsigned long addr,
 496                             unsigned long *symbolsize,
 497                             unsigned long *offset,
 498                             char **modname,
 499                             char *namebuf);
 500 int lookup_module_symbol_name(unsigned long addr, char *symname);
 501 int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name);
 502
 503 /* For extable.c to search modules' exception tables. */
 504 const struct exception_table_entry *search_module_extables(unsigned long addr);
 505
 506 int register_module_notifier(struct notifier_block *nb);
 507 int unregister_module_notifier(struct notifier_block *nb);
 508
 509 extern void print_modules(void);
 510
 511 #else /* !CONFIG_MODULES... */
 512
 513 /* Given an address, look for it in the exception tables. */
 514 static inline const struct exception_table_entry *
 515 search_module_extables(unsigned long addr)
 516 {
 517         return NULL;
 518 }
 519
 520 static inline struct module *__module_address(unsigned long addr)
 521 {
 522         return NULL;
 523 }
 524
 525 static inline struct module *__module_text_address(unsigned long addr)
 526 {
 527         return NULL;
 528 }
 529
 530 static inline bool is_module_address(unsigned long addr)
 531 {
 532         return false;
 533 }
 534
 535 static inline bool is_module_percpu_address(unsigned long addr)
 536 {
 537         return false;
 538 }
 539
 540 static inline bool is_module_text_address(unsigned long addr)
 541 {
 542         return false;
 543 }
 544
 545 /* Get/put a kernel symbol (calls should be symmetric) */
 546 #define symbol_get(x) ({ extern typeof(x) x __attribute__((weak)); &(x); })
 547 #define symbol_put(x) do { } while (0)
 548 #define symbol_put_addr(x) do { } while (0)
 549
 550 static inline void __module_get(struct module *module)
 551 {
 552 }
 553
 554 static inline int try_module_get(struct module *module)
 555 {
 556         return 1;
 557 }
 558
 559 static inline void module_put(struct module *module)
 560 {
 561 }
 562
 563 #define module_name(mod) "kernel"
 564
 565 /* For kallsyms to ask for address resolution.  NULL means not found. */
 566 static inline const char *module_address_lookup(unsigned long addr,
 567                                           unsigned long *symbolsize,
 568                                           unsigned long *offset,
 569                                           char **modname,
 570                                           char *namebuf)
 571 {
 572         return NULL;
 573 }
 574
 575 static inline int lookup_module_symbol_name(unsigned long addr, char *symname)
 576 {
 577         return -ERANGE;
 578 }
 579
 580 static inline int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name)
 581 {
 582         return -ERANGE;
 583 }
 584
 585 static inline int module_get_kallsym(unsigned int symnum, unsigned long *value,
 586                                         char *type, char *name,
 587                                         char *module_name, int *exported)
 588 {
 589         return -ERANGE;
 590 }
 591
 592 static inline unsigned long module_kallsyms_lookup_name(const char *name)
 593 {
 594         return 0;
 595 }
 596
 597 static inline int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
 598                                                            struct module *,
 599                                                            unsigned long),
 600                                                  void *data)
 601 {
 602         return 0;
 603 }
 604
 605 static inline int register_module_notifier(struct notifier_block *nb)
 606 {
 607         /* no events will happen anyway, so this can always succeed */
 608         return 0;
 609 }
 610
 611 static inline int unregister_module_notifier(struct notifier_block *nb)
 612 {
 613         return 0;
 614 }
 615
 616 #define module_put_and_exit(code) do_exit(code)
 617
 618 static inline void print_modules(void)
 619 {
 620 }
 621 #endif /* CONFIG_MODULES */
 622
 623 #ifdef CONFIG_SYSFS
 624 extern struct kset *module_kset;
 625 extern struct kobj_type module_ktype;
 626 extern int module_sysfs_initialized;
 627 #endif /* CONFIG_SYSFS */
 628
 629 #define symbol_request(x) try_then_request_module(symbol_get(x), "symbol:" #x)
 630
 631 /* BELOW HERE ALL THESE ARE OBSOLETE AND WILL VANISH */
 632
 633 #define __MODULE_STRING(x) __stringify(x)
 634
 635 #ifdef CONFIG_DEBUG_SET_MODULE_RONX
 636 extern void set_all_modules_text_rw(void);
 637 extern void set_all_modules_text_ro(void);
 638 #else
 639 static inline void set_all_modules_text_rw(void) { }
 640 static inline void set_all_modules_text_ro(void) { }
 641 #endif
 642
 643 #ifdef CONFIG_GENERIC_BUG
 644 void module_bug_finalize(const Elf_Ehdr *, const Elf_Shdr *,
 645                          struct module *);
 646 void module_bug_cleanup(struct module *);
 647
 648 #else   /* !CONFIG_GENERIC_BUG */
 649
 650 static inline void module_bug_finalize(const Elf_Ehdr *hdr,
 651                                         const Elf_Shdr *sechdrs,
 652                                         struct module *mod)
 653 {
 654 }
 655 static inline void module_bug_cleanup(struct module *mod) {}
 656 #endif  /* CONFIG_GENERIC_BUG */
 657
 658 #endif /* _LINUX_MODULE_H */