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 /**
 209  * struct module_ref - per cpu module reference counts
 210  * @incs: number of module get on this cpu
 211  * @decs: number of module put on this cpu
 212  *
 213  * We force an alignment on 8 or 16 bytes, so that alloc_percpu()
 214  * put @incs/@decs in same cache line, with no extra memory cost,
 215  * since alloc_percpu() is fine grained.
 216  */
 217 struct module_ref {
 218         unsigned long incs;
 219         unsigned long decs;
 220 } __attribute((aligned(2 * sizeof(unsigned long))));
 221
 222 struct module
 223 {
 224         enum module_state state;
 225
 226         /* Member of list of modules */
 227         struct list_head list;
 228
 229         /* Unique handle for this module */
 230         char name[MODULE_NAME_LEN];
 231
 232         /* Sysfs stuff. */
 233         struct module_kobject mkobj;
 234         struct module_attribute *modinfo_attrs;
 235         const char *version;
 236         const char *srcversion;
 237         struct kobject *holders_dir;
 238
 239         /* Exported symbols */
 240         const struct kernel_symbol *syms;
 241         const unsigned long *crcs;
 242         unsigned int num_syms;
 243
 244         /* Kernel parameters. */
 245         struct kernel_param *kp;
 246         unsigned int num_kp;
 247
 248         /* GPL-only exported symbols. */
 249         unsigned int num_gpl_syms;
 250         const struct kernel_symbol *gpl_syms;
 251         const unsigned long *gpl_crcs;
 252
 253 #ifdef CONFIG_UNUSED_SYMBOLS
 254         /* unused exported symbols. */
 255         const struct kernel_symbol *unused_syms;
 256         const unsigned long *unused_crcs;
 257         unsigned int num_unused_syms;
 258
 259         /* GPL-only, unused exported symbols. */
 260         unsigned int num_unused_gpl_syms;
 261         const struct kernel_symbol *unused_gpl_syms;
 262         const unsigned long *unused_gpl_crcs;
 263 #endif
 264
 265         /* symbols that will be GPL-only in the near future. */
 266         const struct kernel_symbol *gpl_future_syms;
 267         const unsigned long *gpl_future_crcs;
 268         unsigned int num_gpl_future_syms;
 269
 270         /* Exception table */
 271         unsigned int num_exentries;
 272         struct exception_table_entry *extable;
 273
 274         /* Startup function. */
 275         int (*init)(void);
 276
 277         /* If this is non-NULL, vfree after init() returns */
 278         void *module_init;
 279
 280         /* Here is the actual code + data, vfree'd on unload. */
 281         void *module_core;
 282
 283         /* Here are the sizes of the init and core sections */
 284         unsigned int init_size, core_size;
 285
 286         /* The size of the executable code in each section.  */
 287         unsigned int init_text_size, core_text_size;
 288
 289         /* Size of RO sections of the module (text+rodata) */
 290         unsigned int init_ro_size, core_ro_size;
 291
 292         /* Arch-specific module values */
 293         struct mod_arch_specific arch;
 294
 295         unsigned int taints;    /* same bits as kernel:tainted */
 296
 297 #ifdef CONFIG_GENERIC_BUG
 298         /* Support for BUG */
 299         unsigned num_bugs;
 300         struct list_head bug_list;
 301         struct bug_entry *bug_table;
 302 #endif
 303
 304 #ifdef CONFIG_KALLSYMS
 305         /*
 306          * We keep the symbol and string tables for kallsyms.
 307          * The core_* fields below are temporary, loader-only (they
 308          * could really be discarded after module init).
 309          */
 310         Elf_Sym *symtab, *core_symtab;
 311         unsigned int num_symtab, core_num_syms;
 312         char *strtab, *core_strtab;
 313
 314         /* Section attributes */
 315         struct module_sect_attrs *sect_attrs;
 316
 317         /* Notes attributes */
 318         struct module_notes_attrs *notes_attrs;
 319 #endif
 320
 321         /* The command line arguments (may be mangled).  People like
 322            keeping pointers to this stuff */
 323         char *args;
 324
 325 #ifdef CONFIG_SMP
 326         /* Per-cpu data. */
 327         void __percpu *percpu;
 328         unsigned int percpu_size;
 329 #endif
 330
 331 #ifdef CONFIG_TRACEPOINTS
 332         unsigned int num_tracepoints;
 333         struct tracepoint * const *tracepoints_ptrs;
 334 #endif
 335 #ifdef HAVE_JUMP_LABEL
 336         struct jump_entry *jump_entries;
 337         unsigned int num_jump_entries;
 338 #endif
 339 #ifdef CONFIG_TRACING
 340         unsigned int num_trace_bprintk_fmt;
 341         const char **trace_bprintk_fmt_start;
 342 #endif
 343 #ifdef CONFIG_EVENT_TRACING
 344         struct ftrace_event_call **trace_events;
 345         unsigned int num_trace_events;
 346 #endif
 347 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
 348         unsigned int num_ftrace_callsites;
 349         unsigned long *ftrace_callsites;
 350 #endif
 351
 352 #ifdef CONFIG_MODULE_UNLOAD
 353         /* What modules depend on me? */
 354         struct list_head source_list;
 355         /* What modules do I depend on? */
 356         struct list_head target_list;
 357
 358         /* Who is waiting for us to be unloaded */
 359         struct task_struct *waiter;
 360
 361         /* Destruction function. */
 362         void (*exit)(void);
 363
 364         struct module_ref __percpu *refptr;
 365 #endif
 366
 367 #ifdef CONFIG_CONSTRUCTORS
 368         /* Constructor functions. */
 369         ctor_fn_t *ctors;
 370         unsigned int num_ctors;
 371 #endif
 372 };
 373 #ifndef MODULE_ARCH_INIT
 374 #define MODULE_ARCH_INIT {}
 375 #endif
 376
 377 extern struct mutex module_mutex;
 378
 379 /* FIXME: It'd be nice to isolate modules during init, too, so they
 380    aren't used before they (may) fail.  But presently too much code
 381    (IDE & SCSI) require entry into the module during init.*/
 382 static inline int module_is_live(struct module *mod)
 383 {
 384         return mod->state != MODULE_STATE_GOING;
 385 }
 386
 387 struct module *__module_text_address(unsigned long addr);
 388 struct module *__module_address(unsigned long addr);
 389 bool is_module_address(unsigned long addr);
 390 bool is_module_percpu_address(unsigned long addr);
 391 bool is_module_text_address(unsigned long addr);
 392
 393 static inline int within_module_core(unsigned long addr, struct module *mod)
 394 {
 395         return (unsigned long)mod->module_core <= addr &&
 396                addr < (unsigned long)mod->module_core + mod->core_size;
 397 }
 398
 399 static inline int within_module_init(unsigned long addr, 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 /* Search for module by name: must hold module_mutex. */
 406 struct module *find_module(const char *name);
 407
 408 struct symsearch {
 409         const struct kernel_symbol *start, *stop;
 410         const unsigned long *crcs;
 411         enum {
 412                 NOT_GPL_ONLY,
 413                 GPL_ONLY,
 414                 WILL_BE_GPL_ONLY,
 415         } licence;
 416         bool unused;
 417 };
 418
 419 /* Search for an exported symbol by name. */
 420 const struct kernel_symbol *find_symbol(const char *name,
 421                                         struct module **owner,
 422                                         const unsigned long **crc,
 423                                         bool gplok,
 424                                         bool warn);
 425
 426 /* Walk the exported symbol table */
 427 bool each_symbol_section(bool (*fn)(const struct symsearch *arr,
 428                                     struct module *owner,
 429                                     void *data), void *data);
 430
 431 /* Returns 0 and fills in value, defined and namebuf, or -ERANGE if
 432    symnum out of range. */
 433 int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
 434                         char *name, char *module_name, int *exported);
 435
 436 /* Look for this name: can be of form module:name. */
 437 unsigned long module_kallsyms_lookup_name(const char *name);
 438
 439 int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
 440                                              struct module *, unsigned long),
 441                                    void *data);
 442
 443 extern void __module_put_and_exit(struct module *mod, long code)
 444         __attribute__((noreturn));
 445 #define module_put_and_exit(code) __module_put_and_exit(THIS_MODULE, code);
 446
 447 #ifdef CONFIG_MODULE_UNLOAD
 448 unsigned long module_refcount(struct module *mod);
 449 void __symbol_put(const char *symbol);
 450 #define symbol_put(x) __symbol_put(MODULE_SYMBOL_PREFIX #x)
 451 void symbol_put_addr(void *addr);
 452
 453 /* Sometimes we know we already have a refcount, and it's easier not
 454    to handle the error case (which only happens with rmmod --wait). */
 455 static inline void __module_get(struct module *module)
 456 {
 457         if (module) {
 458                 preempt_disable();
 459                 __this_cpu_inc(module->refptr->incs);
 460                 trace_module_get(module, _THIS_IP_);
 461                 preempt_enable();
 462         }
 463 }
 464
 465 static inline int try_module_get(struct module *module)
 466 {
 467         int ret = 1;
 468
 469         if (module) {
 470                 preempt_disable();
 471
 472                 if (likely(module_is_live(module))) {
 473                         __this_cpu_inc(module->refptr->incs);
 474                         trace_module_get(module, _THIS_IP_);
 475                 } else
 476                         ret = 0;
 477
 478                 preempt_enable();
 479         }
 480         return ret;
 481 }
 482
 483 extern void module_put(struct module *module);
 484
 485 #else /*!CONFIG_MODULE_UNLOAD*/
 486 static inline int try_module_get(struct module *module)
 487 {
 488         return !module || module_is_live(module);
 489 }
 490 static inline void module_put(struct module *module)
 491 {
 492 }
 493 static inline void __module_get(struct module *module)
 494 {
 495 }
 496 #define symbol_put(x) do { } while(0)
 497 #define symbol_put_addr(p) do { } while(0)
 498
 499 #endif /* CONFIG_MODULE_UNLOAD */
 500 int ref_module(struct module *a, struct module *b);
 501
 502 /* This is a #define so the string doesn't get put in every .o file */
 503 #define module_name(mod)                        \
 504 ({                                              \
 505         struct module *__mod = (mod);           \
 506         __mod ? __mod->name : "kernel";         \
 507 })
 508
 509 /* For kallsyms to ask for address resolution.  namebuf should be at
 510  * least KSYM_NAME_LEN long: a pointer to namebuf is returned if
 511  * found, otherwise NULL. */
 512 const char *module_address_lookup(unsigned long addr,
 513                             unsigned long *symbolsize,
 514                             unsigned long *offset,
 515                             char **modname,
 516                             char *namebuf);
 517 int lookup_module_symbol_name(unsigned long addr, char *symname);
 518 int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name);
 519
 520 /* For extable.c to search modules' exception tables. */
 521 const struct exception_table_entry *search_module_extables(unsigned long addr);
 522
 523 int register_module_notifier(struct notifier_block * nb);
 524 int unregister_module_notifier(struct notifier_block * nb);
 525
 526 extern void print_modules(void);
 527
 528 #else /* !CONFIG_MODULES... */
 529
 530 /* Given an address, look for it in the exception tables. */
 531 static inline const struct exception_table_entry *
 532 search_module_extables(unsigned long addr)
 533 {
 534         return NULL;
 535 }
 536
 537 static inline struct module *__module_address(unsigned long addr)
 538 {
 539         return NULL;
 540 }
 541
 542 static inline struct module *__module_text_address(unsigned long addr)
 543 {
 544         return NULL;
 545 }
 546
 547 static inline bool is_module_address(unsigned long addr)
 548 {
 549         return false;
 550 }
 551
 552 static inline bool is_module_percpu_address(unsigned long addr)
 553 {
 554         return false;
 555 }
 556
 557 static inline bool is_module_text_address(unsigned long addr)
 558 {
 559         return false;
 560 }
 561
 562 /* Get/put a kernel symbol (calls should be symmetric) */
 563 #define symbol_get(x) ({ extern typeof(x) x __attribute__((weak)); &(x); })
 564 #define symbol_put(x) do { } while(0)
 565 #define symbol_put_addr(x) do { } while(0)
 566
 567 static inline void __module_get(struct module *module)
 568 {
 569 }
 570
 571 static inline int try_module_get(struct module *module)
 572 {
 573         return 1;
 574 }
 575
 576 static inline void module_put(struct module *module)
 577 {
 578 }
 579
 580 #define module_name(mod) "kernel"
 581
 582 /* For kallsyms to ask for address resolution.  NULL means not found. */
 583 static inline const char *module_address_lookup(unsigned long addr,
 584                                           unsigned long *symbolsize,
 585                                           unsigned long *offset,
 586                                           char **modname,
 587                                           char *namebuf)
 588 {
 589         return NULL;
 590 }
 591
 592 static inline int lookup_module_symbol_name(unsigned long addr, char *symname)
 593 {
 594         return -ERANGE;
 595 }
 596
 597 static inline int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name)
 598 {
 599         return -ERANGE;
 600 }
 601
 602 static inline int module_get_kallsym(unsigned int symnum, unsigned long *value,
 603                                         char *type, char *name,
 604                                         char *module_name, int *exported)
 605 {
 606         return -ERANGE;
 607 }
 608
 609 static inline unsigned long module_kallsyms_lookup_name(const char *name)
 610 {
 611         return 0;
 612 }
 613
 614 static inline int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
 615                                                            struct module *,
 616                                                            unsigned long),
 617                                                  void *data)
 618 {
 619         return 0;
 620 }
 621
 622 static inline int register_module_notifier(struct notifier_block * nb)
 623 {
 624         /* no events will happen anyway, so this can always succeed */
 625         return 0;
 626 }
 627
 628 static inline int unregister_module_notifier(struct notifier_block * nb)
 629 {
 630         return 0;
 631 }
 632
 633 #define module_put_and_exit(code) do_exit(code)
 634
 635 static inline void print_modules(void)
 636 {
 637 }
 638 #endif /* CONFIG_MODULES */
 639
 640 #ifdef CONFIG_SYSFS
 641 extern struct kset *module_kset;
 642 extern struct kobj_type module_ktype;
 643 extern int module_sysfs_initialized;
 644 #endif /* CONFIG_SYSFS */
 645
 646 #define symbol_request(x) try_then_request_module(symbol_get(x), "symbol:" #x)
 647
 648 /* BELOW HERE ALL THESE ARE OBSOLETE AND WILL VANISH */
 649
 650 #define __MODULE_STRING(x) __stringify(x)
 651
 652 #ifdef CONFIG_DEBUG_SET_MODULE_RONX
 653 extern void set_all_modules_text_rw(void);
 654 extern void set_all_modules_text_ro(void);
 655 #else
 656 static inline void set_all_modules_text_rw(void) { }
 657 static inline void set_all_modules_text_ro(void) { }
 658 #endif
 659
 660 #ifdef CONFIG_GENERIC_BUG
 661 void module_bug_finalize(const Elf_Ehdr *, const Elf_Shdr *,
 662                          struct module *);
 663 void module_bug_cleanup(struct module *);
 664
 665 #else   /* !CONFIG_GENERIC_BUG */
 666
 667 static inline void module_bug_finalize(const Elf_Ehdr *hdr,
 668                                         const Elf_Shdr *sechdrs,
 669                                         struct module *mod)
 670 {
 671 }
 672 static inline void module_bug_cleanup(struct module *mod) {}
 673 #endif  /* CONFIG_GENERIC_BUG */
 674
 675 #endif /* _LINUX_MODULE_H */