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 struct type##_device_id __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 /**
 214  * struct module_ref - per cpu module reference counts
 215  * @incs: number of module get on this cpu
 216  * @decs: number of module put on this cpu
 217  *
 218  * We force an alignment on 8 or 16 bytes, so that alloc_percpu()
 219  * put @incs/@decs in same cache line, with no extra memory cost,
 220  * since alloc_percpu() is fine grained.
 221  */
 222 struct module_ref {
 223         unsigned long incs;
 224         unsigned long decs;
 225 } __attribute((aligned(2 * sizeof(unsigned long))));
 226
 227 struct module {
 228         enum module_state state;
 229
 230         /* Member of list of modules */
 231         struct list_head list;
 232
 233         /* Unique handle for this module */
 234         char name[MODULE_NAME_LEN];
 235
 236         /* Sysfs stuff. */
 237         struct module_kobject mkobj;
 238         struct module_attribute *modinfo_attrs;
 239         const char *version;
 240         const char *srcversion;
 241         struct kobject *holders_dir;
 242
 243         /* Exported symbols */
 244         const struct kernel_symbol *syms;
 245         const unsigned long *crcs;
 246         unsigned int num_syms;
 247
 248         /* Kernel parameters. */
 249         struct kernel_param *kp;
 250         unsigned int num_kp;
 251
 252         /* GPL-only exported symbols. */
 253         unsigned int num_gpl_syms;
 254         const struct kernel_symbol *gpl_syms;
 255         const unsigned long *gpl_crcs;
 256
 257 #ifdef CONFIG_UNUSED_SYMBOLS
 258         /* unused exported symbols. */
 259         const struct kernel_symbol *unused_syms;
 260         const unsigned long *unused_crcs;
 261         unsigned int num_unused_syms;
 262
 263         /* GPL-only, unused exported symbols. */
 264         unsigned int num_unused_gpl_syms;
 265         const struct kernel_symbol *unused_gpl_syms;
 266         const unsigned long *unused_gpl_crcs;
 267 #endif
 268
 269 #ifdef CONFIG_MODULE_SIG
 270         /* Signature was verified. */
 271         bool sig_ok;
 272 #endif
 273
 274         /* symbols that will be GPL-only in the near future. */
 275         const struct kernel_symbol *gpl_future_syms;
 276         const unsigned long *gpl_future_crcs;
 277         unsigned int num_gpl_future_syms;
 278
 279         /* Exception table */
 280         unsigned int num_exentries;
 281         struct exception_table_entry *extable;
 282
 283         /* Startup function. */
 284         int (*init)(void);
 285
 286         /* If this is non-NULL, vfree after init() returns */
 287         void *module_init;
 288
 289         /* Here is the actual code + data, vfree'd on unload. */
 290         void *module_core;
 291
 292         /* Here are the sizes of the init and core sections */
 293         unsigned int init_size, core_size;
 294
 295         /* The size of the executable code in each section.  */
 296         unsigned int init_text_size, core_text_size;
 297
 298         /* Size of RO sections of the module (text+rodata) */
 299         unsigned int init_ro_size, core_ro_size;
 300
 301         /* Arch-specific module values */
 302         struct mod_arch_specific arch;
 303
 304         unsigned int taints;    /* same bits as kernel:tainted */
 305
 306 #ifdef CONFIG_GENERIC_BUG
 307         /* Support for BUG */
 308         unsigned num_bugs;
 309         struct list_head bug_list;
 310         struct bug_entry *bug_table;
 311 #endif
 312
 313 #ifdef CONFIG_KALLSYMS
 314         /*
 315          * We keep the symbol and string tables for kallsyms.
 316          * The core_* fields below are temporary, loader-only (they
 317          * could really be discarded after module init).
 318          */
 319         Elf_Sym *symtab, *core_symtab;
 320         unsigned int num_symtab, core_num_syms;
 321         char *strtab, *core_strtab;
 322
 323         /* Section attributes */
 324         struct module_sect_attrs *sect_attrs;
 325
 326         /* Notes attributes */
 327         struct module_notes_attrs *notes_attrs;
 328 #endif
 329
 330         /* The command line arguments (may be mangled).  People like
 331            keeping pointers to this stuff */
 332         char *args;
 333
 334 #ifdef CONFIG_SMP
 335         /* Per-cpu data. */
 336         void __percpu *percpu;
 337         unsigned int percpu_size;
 338 #endif
 339
 340 #ifdef CONFIG_TRACEPOINTS
 341         unsigned int num_tracepoints;
 342         struct tracepoint * const *tracepoints_ptrs;
 343 #endif
 344 #ifdef HAVE_JUMP_LABEL
 345         struct jump_entry *jump_entries;
 346         unsigned int num_jump_entries;
 347 #endif
 348 #ifdef CONFIG_TRACING
 349         unsigned int num_trace_bprintk_fmt;
 350         const char **trace_bprintk_fmt_start;
 351 #endif
 352 #ifdef CONFIG_EVENT_TRACING
 353         struct ftrace_event_call **trace_events;
 354         unsigned int num_trace_events;
 355 #endif
 356 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
 357         unsigned int num_ftrace_callsites;
 358         unsigned long *ftrace_callsites;
 359 #endif
 360
 361 #ifdef CONFIG_MODULE_UNLOAD
 362         /* What modules depend on me? */
 363         struct list_head source_list;
 364         /* What modules do I depend on? */
 365         struct list_head target_list;
 366
 367         /* Destruction function. */
 368         void (*exit)(void);
 369
 370         struct module_ref __percpu *refptr;
 371 #endif
 372
 373 #ifdef CONFIG_CONSTRUCTORS
 374         /* Constructor functions. */
 375         ctor_fn_t *ctors;
 376         unsigned int num_ctors;
 377 #endif
 378 };
 379 #ifndef MODULE_ARCH_INIT
 380 #define MODULE_ARCH_INIT {}
 381 #endif
 382
 383 extern struct mutex module_mutex;
 384
 385 /* FIXME: It'd be nice to isolate modules during init, too, so they
 386    aren't used before they (may) fail.  But presently too much code
 387    (IDE & SCSI) require entry into the module during init.*/
 388 static inline int module_is_live(struct module *mod)
 389 {
 390         return mod->state != MODULE_STATE_GOING;
 391 }
 392
 393 struct module *__module_text_address(unsigned long addr);
 394 struct module *__module_address(unsigned long addr);
 395 bool is_module_address(unsigned long addr);
 396 bool is_module_percpu_address(unsigned long addr);
 397 bool is_module_text_address(unsigned long addr);
 398
 399 static inline bool within_module_core(unsigned long addr,
 400                                       const struct module *mod)
 401 {
 402         return (unsigned long)mod->module_core <= addr &&
 403                addr < (unsigned long)mod->module_core + mod->core_size;
 404 }
 405
 406 static inline bool within_module_init(unsigned long addr,
 407                                       const struct module *mod)
 408 {
 409         return (unsigned long)mod->module_init <= addr &&
 410                addr < (unsigned long)mod->module_init + mod->init_size;
 411 }
 412
 413 static inline bool within_module(unsigned long addr, const struct module *mod)
 414 {
 415         return within_module_init(addr, mod) || within_module_core(addr, mod);
 416 }
 417
 418 /* Search for module by name: must hold module_mutex. */
 419 struct module *find_module(const char *name);
 420
 421 struct symsearch {
 422         const struct kernel_symbol *start, *stop;
 423         const unsigned long *crcs;
 424         enum {
 425                 NOT_GPL_ONLY,
 426                 GPL_ONLY,
 427                 WILL_BE_GPL_ONLY,
 428         } licence;
 429         bool unused;
 430 };
 431
 432 /* Search for an exported symbol by name. */
 433 const struct kernel_symbol *find_symbol(const char *name,
 434                                         struct module **owner,
 435                                         const unsigned long **crc,
 436                                         bool gplok,
 437                                         bool warn);
 438
 439 /* Walk the exported symbol table */
 440 bool each_symbol_section(bool (*fn)(const struct symsearch *arr,
 441                                     struct module *owner,
 442                                     void *data), void *data);
 443
 444 /* Returns 0 and fills in value, defined and namebuf, or -ERANGE if
 445    symnum out of range. */
 446 int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
 447                         char *name, char *module_name, int *exported);
 448
 449 /* Look for this name: can be of form module:name. */
 450 unsigned long module_kallsyms_lookup_name(const char *name);
 451
 452 int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
 453                                              struct module *, unsigned long),
 454                                    void *data);
 455
 456 extern void __module_put_and_exit(struct module *mod, long code)
 457         __attribute__((noreturn));
 458 #define module_put_and_exit(code) __module_put_and_exit(THIS_MODULE, code)
 459
 460 #ifdef CONFIG_MODULE_UNLOAD
 461 unsigned long module_refcount(struct module *mod);
 462 void __symbol_put(const char *symbol);
 463 #define symbol_put(x) __symbol_put(VMLINUX_SYMBOL_STR(x))
 464 void symbol_put_addr(void *addr);
 465
 466 /* Sometimes we know we already have a refcount, and it's easier not
 467    to handle the error case (which only happens with rmmod --wait). */
 468 extern void __module_get(struct module *module);
 469
 470 /* This is the Right Way to get a module: if it fails, it's being removed,
 471  * so pretend it's not there. */
 472 extern bool try_module_get(struct module *module);
 473
 474 extern void module_put(struct module *module);
 475
 476 #else /*!CONFIG_MODULE_UNLOAD*/
 477 static inline int try_module_get(struct module *module)
 478 {
 479         return !module || module_is_live(module);
 480 }
 481 static inline void module_put(struct module *module)
 482 {
 483 }
 484 static inline void __module_get(struct module *module)
 485 {
 486 }
 487 #define symbol_put(x) do { } while (0)
 488 #define symbol_put_addr(p) do { } while (0)
 489
 490 #endif /* CONFIG_MODULE_UNLOAD */
 491 int ref_module(struct module *a, struct module *b);
 492
 493 /* This is a #define so the string doesn't get put in every .o file */
 494 #define module_name(mod)                        \
 495 ({                                              \
 496         struct module *__mod = (mod);           \
 497         __mod ? __mod->name : "kernel";         \
 498 })
 499
 500 /* For kallsyms to ask for address resolution.  namebuf should be at
 501  * least KSYM_NAME_LEN long: a pointer to namebuf is returned if
 502  * found, otherwise NULL. */
 503 const char *module_address_lookup(unsigned long addr,
 504                             unsigned long *symbolsize,
 505                             unsigned long *offset,
 506                             char **modname,
 507                             char *namebuf);
 508 int lookup_module_symbol_name(unsigned long addr, char *symname);
 509 int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name);
 510
 511 /* For extable.c to search modules' exception tables. */
 512 const struct exception_table_entry *search_module_extables(unsigned long addr);
 513
 514 int register_module_notifier(struct notifier_block *nb);
 515 int unregister_module_notifier(struct notifier_block *nb);
 516
 517 extern void print_modules(void);
 518
 519 #else /* !CONFIG_MODULES... */
 520
 521 /* Given an address, look for it in the exception tables. */
 522 static inline const struct exception_table_entry *
 523 search_module_extables(unsigned long addr)
 524 {
 525         return NULL;
 526 }
 527
 528 static inline struct module *__module_address(unsigned long addr)
 529 {
 530         return NULL;
 531 }
 532
 533 static inline struct module *__module_text_address(unsigned long addr)
 534 {
 535         return NULL;
 536 }
 537
 538 static inline bool is_module_address(unsigned long addr)
 539 {
 540         return false;
 541 }
 542
 543 static inline bool is_module_percpu_address(unsigned long addr)
 544 {
 545         return false;
 546 }
 547
 548 static inline bool is_module_text_address(unsigned long addr)
 549 {
 550         return false;
 551 }
 552
 553 /* Get/put a kernel symbol (calls should be symmetric) */
 554 #define symbol_get(x) ({ extern typeof(x) x __attribute__((weak)); &(x); })
 555 #define symbol_put(x) do { } while (0)
 556 #define symbol_put_addr(x) do { } while (0)
 557
 558 static inline void __module_get(struct module *module)
 559 {
 560 }
 561
 562 static inline int try_module_get(struct module *module)
 563 {
 564         return 1;
 565 }
 566
 567 static inline void module_put(struct module *module)
 568 {
 569 }
 570
 571 #define module_name(mod) "kernel"
 572
 573 /* For kallsyms to ask for address resolution.  NULL means not found. */
 574 static inline const char *module_address_lookup(unsigned long addr,
 575                                           unsigned long *symbolsize,
 576                                           unsigned long *offset,
 577                                           char **modname,
 578                                           char *namebuf)
 579 {
 580         return NULL;
 581 }
 582
 583 static inline int lookup_module_symbol_name(unsigned long addr, char *symname)
 584 {
 585         return -ERANGE;
 586 }
 587
 588 static inline int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name)
 589 {
 590         return -ERANGE;
 591 }
 592
 593 static inline int module_get_kallsym(unsigned int symnum, unsigned long *value,
 594                                         char *type, char *name,
 595                                         char *module_name, int *exported)
 596 {
 597         return -ERANGE;
 598 }
 599
 600 static inline unsigned long module_kallsyms_lookup_name(const char *name)
 601 {
 602         return 0;
 603 }
 604
 605 static inline int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
 606                                                            struct module *,
 607                                                            unsigned long),
 608                                                  void *data)
 609 {
 610         return 0;
 611 }
 612
 613 static inline int register_module_notifier(struct notifier_block *nb)
 614 {
 615         /* no events will happen anyway, so this can always succeed */
 616         return 0;
 617 }
 618
 619 static inline int unregister_module_notifier(struct notifier_block *nb)
 620 {
 621         return 0;
 622 }
 623
 624 #define module_put_and_exit(code) do_exit(code)
 625
 626 static inline void print_modules(void)
 627 {
 628 }
 629 #endif /* CONFIG_MODULES */
 630
 631 #ifdef CONFIG_SYSFS
 632 extern struct kset *module_kset;
 633 extern struct kobj_type module_ktype;
 634 extern int module_sysfs_initialized;
 635 #endif /* CONFIG_SYSFS */
 636
 637 #define symbol_request(x) try_then_request_module(symbol_get(x), "symbol:" #x)
 638
 639 /* BELOW HERE ALL THESE ARE OBSOLETE AND WILL VANISH */
 640
 641 #define __MODULE_STRING(x) __stringify(x)
 642
 643 #ifdef CONFIG_DEBUG_SET_MODULE_RONX
 644 extern void set_all_modules_text_rw(void);
 645 extern void set_all_modules_text_ro(void);
 646 #else
 647 static inline void set_all_modules_text_rw(void) { }
 648 static inline void set_all_modules_text_ro(void) { }
 649 #endif
 650
 651 #ifdef CONFIG_GENERIC_BUG
 652 void module_bug_finalize(const Elf_Ehdr *, const Elf_Shdr *,
 653                          struct module *);
 654 void module_bug_cleanup(struct module *);
 655
 656 #else   /* !CONFIG_GENERIC_BUG */
 657
 658 static inline void module_bug_finalize(const Elf_Ehdr *hdr,
 659                                         const Elf_Shdr *sechdrs,
 660                                         struct module *mod)
 661 {
 662 }
 663 static inline void module_bug_cleanup(struct module *mod) {}
 664 #endif  /* CONFIG_GENERIC_BUG */
 665
 666 #endif /* _LINUX_MODULE_H */