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 /* 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 #ifdef MODULE
  86 #define MODULE_GENERIC_TABLE(gtype, name)                       \
  87 extern const struct gtype##_id __mod_##gtype##_table            \
  88   __attribute__ ((unused, alias(__stringify(name))))
  89
  90 #else  /* !MODULE */
  91 #define MODULE_GENERIC_TABLE(gtype, name)
  92 #endif
  93
  94 /* Generic info of form tag = "info" */
  95 #define MODULE_INFO(tag, info) __MODULE_INFO(tag, tag, info)
  96
  97 /* For userspace: you can also call me... */
  98 #define MODULE_ALIAS(_alias) MODULE_INFO(alias, _alias)
  99
 100 /* Soft module dependencies. See man modprobe.d for details.
 101  * Example: MODULE_SOFTDEP("pre: module-foo module-bar post: module-baz")
 102  */
 103 #define MODULE_SOFTDEP(_softdep) MODULE_INFO(softdep, _softdep)
 104
 105 /*
 106  * The following license idents are currently accepted as indicating free
 107  * software modules
 108  *
 109  *      "GPL"                           [GNU Public License v2 or later]
 110  *      "GPL v2"                        [GNU Public License v2]
 111  *      "GPL and additional rights"     [GNU Public License v2 rights and more]
 112  *      "Dual BSD/GPL"                  [GNU Public License v2
 113  *                                       or BSD license choice]
 114  *      "Dual MIT/GPL"                  [GNU Public License v2
 115  *                                       or MIT license choice]
 116  *      "Dual MPL/GPL"                  [GNU Public License v2
 117  *                                       or Mozilla license choice]
 118  *
 119  * The following other idents are available
 120  *
 121  *      "Proprietary"                   [Non free products]
 122  *
 123  * There are dual licensed components, but when running with Linux it is the
 124  * GPL that is relevant so this is a non issue. Similarly LGPL linked with GPL
 125  * is a GPL combined work.
 126  *
 127  * This exists for several reasons
 128  * 1.   So modinfo can show license info for users wanting to vet their setup
 129  *      is free
 130  * 2.   So the community can ignore bug reports including proprietary modules
 131  * 3.   So vendors can do likewise based on their own policies
 132  */
 133 #define MODULE_LICENSE(_license) MODULE_INFO(license, _license)
 134
 135 /*
 136  * Author(s), use "Name <email>" or just "Name", for multiple
 137  * authors use multiple MODULE_AUTHOR() statements/lines.
 138  */
 139 #define MODULE_AUTHOR(_author) MODULE_INFO(author, _author)
 140
 141 /* What your module does. */
 142 #define MODULE_DESCRIPTION(_description) MODULE_INFO(description, _description)
 143
 144 #define MODULE_DEVICE_TABLE(type, name)         \
 145   MODULE_GENERIC_TABLE(type##_device, name)
 146
 147 /* Version of form [<epoch>:]<version>[-<extra-version>].
 148  * Or for CVS/RCS ID version, everything but the number is stripped.
 149  * <epoch>: A (small) unsigned integer which allows you to start versions
 150  * anew. If not mentioned, it's zero.  eg. "2:1.0" is after
 151  * "1:2.0".
 152
 153  * <version>: The <version> may contain only alphanumerics and the
 154  * character `.'.  Ordered by numeric sort for numeric parts,
 155  * ascii sort for ascii parts (as per RPM or DEB algorithm).
 156
 157  * <extraversion>: Like <version>, but inserted for local
 158  * customizations, eg "rh3" or "rusty1".
 159
 160  * Using this automatically adds a checksum of the .c files and the
 161  * local headers in "srcversion".
 162  */
 163
 164 #if defined(MODULE) || !defined(CONFIG_SYSFS)
 165 #define MODULE_VERSION(_version) MODULE_INFO(version, _version)
 166 #else
 167 #define MODULE_VERSION(_version)                                        \
 168         static struct module_version_attribute ___modver_attr = {       \
 169                 .mattr  = {                                             \
 170                         .attr   = {                                     \
 171                                 .name   = "version",                    \
 172                                 .mode   = S_IRUGO,                      \
 173                         },                                              \
 174                         .show   = __modver_version_show,                \
 175                 },                                                      \
 176                 .module_name    = KBUILD_MODNAME,                       \
 177                 .version        = _version,                             \
 178         };                                                              \
 179         static const struct module_version_attribute                    \
 180         __used __attribute__ ((__section__ ("__modver")))               \
 181         * __moduleparam_const __modver_attr = &___modver_attr
 182 #endif
 183
 184 /* Optional firmware file (or files) needed by the module
 185  * format is simply firmware file name.  Multiple firmware
 186  * files require multiple MODULE_FIRMWARE() specifiers */
 187 #define MODULE_FIRMWARE(_firmware) MODULE_INFO(firmware, _firmware)
 188
 189 /* Given an address, look for it in the exception tables */
 190 const struct exception_table_entry *search_exception_tables(unsigned long add);
 191
 192 struct notifier_block;
 193
 194 #ifdef CONFIG_MODULES
 195
 196 extern int modules_disabled; /* for sysctl */
 197 /* Get/put a kernel symbol (calls must be symmetric) */
 198 void *__symbol_get(const char *symbol);
 199 void *__symbol_get_gpl(const char *symbol);
 200 #define symbol_get(x) ((typeof(&x))(__symbol_get(VMLINUX_SYMBOL_STR(x))))
 201
 202 /* modules using other modules: kdb wants to see this. */
 203 struct module_use {
 204         struct list_head source_list;
 205         struct list_head target_list;
 206         struct module *source, *target;
 207 };
 208
 209 enum module_state {
 210         MODULE_STATE_LIVE,      /* Normal state. */
 211         MODULE_STATE_COMING,    /* Full formed, running module_init. */
 212         MODULE_STATE_GOING,     /* Going away. */
 213         MODULE_STATE_UNFORMED,  /* Still setting it up. */
 214 };
 215
 216 /**
 217  * struct module_ref - per cpu module reference counts
 218  * @incs: number of module get on this cpu
 219  * @decs: number of module put on this cpu
 220  *
 221  * We force an alignment on 8 or 16 bytes, so that alloc_percpu()
 222  * put @incs/@decs in same cache line, with no extra memory cost,
 223  * since alloc_percpu() is fine grained.
 224  */
 225 struct module_ref {
 226         unsigned long incs;
 227         unsigned long decs;
 228 } __attribute((aligned(2 * sizeof(unsigned long))));
 229
 230 struct module {
 231         enum module_state state;
 232
 233         /* Member of list of modules */
 234         struct list_head list;
 235
 236         /* Unique handle for this module */
 237         char name[MODULE_NAME_LEN];
 238
 239         /* Sysfs stuff. */
 240         struct module_kobject mkobj;
 241         struct module_attribute *modinfo_attrs;
 242         const char *version;
 243         const char *srcversion;
 244         struct kobject *holders_dir;
 245
 246         /* Exported symbols */
 247         const struct kernel_symbol *syms;
 248         const unsigned long *crcs;
 249         unsigned int num_syms;
 250
 251         /* Kernel parameters. */
 252         struct kernel_param *kp;
 253         unsigned int num_kp;
 254
 255         /* GPL-only exported symbols. */
 256         unsigned int num_gpl_syms;
 257         const struct kernel_symbol *gpl_syms;
 258         const unsigned long *gpl_crcs;
 259
 260 #ifdef CONFIG_UNUSED_SYMBOLS
 261         /* unused exported symbols. */
 262         const struct kernel_symbol *unused_syms;
 263         const unsigned long *unused_crcs;
 264         unsigned int num_unused_syms;
 265
 266         /* GPL-only, unused exported symbols. */
 267         unsigned int num_unused_gpl_syms;
 268         const struct kernel_symbol *unused_gpl_syms;
 269         const unsigned long *unused_gpl_crcs;
 270 #endif
 271
 272 #ifdef CONFIG_MODULE_SIG
 273         /* Signature was verified. */
 274         bool sig_ok;
 275 #endif
 276
 277         /* symbols that will be GPL-only in the near future. */
 278         const struct kernel_symbol *gpl_future_syms;
 279         const unsigned long *gpl_future_crcs;
 280         unsigned int num_gpl_future_syms;
 281
 282         /* Exception table */
 283         unsigned int num_exentries;
 284         struct exception_table_entry *extable;
 285
 286         /* Startup function. */
 287         int (*init)(void);
 288
 289         /* If this is non-NULL, vfree after init() returns */
 290         void *module_init;
 291
 292         /* Here is the actual code + data, vfree'd on unload. */
 293         void *module_core;
 294
 295         /* Here are the sizes of the init and core sections */
 296         unsigned int init_size, core_size;
 297
 298         /* The size of the executable code in each section.  */
 299         unsigned int init_text_size, core_text_size;
 300
 301         /* Size of RO sections of the module (text+rodata) */
 302         unsigned int init_ro_size, core_ro_size;
 303
 304         /* Arch-specific module values */
 305         struct mod_arch_specific arch;
 306
 307         unsigned int taints;    /* same bits as kernel:tainted */
 308
 309 #ifdef CONFIG_GENERIC_BUG
 310         /* Support for BUG */
 311         unsigned num_bugs;
 312         struct list_head bug_list;
 313         struct bug_entry *bug_table;
 314 #endif
 315
 316 #ifdef CONFIG_KALLSYMS
 317         /*
 318          * We keep the symbol and string tables for kallsyms.
 319          * The core_* fields below are temporary, loader-only (they
 320          * could really be discarded after module init).
 321          */
 322         Elf_Sym *symtab, *core_symtab;
 323         unsigned int num_symtab, core_num_syms;
 324         char *strtab, *core_strtab;
 325
 326         /* Section attributes */
 327         struct module_sect_attrs *sect_attrs;
 328
 329         /* Notes attributes */
 330         struct module_notes_attrs *notes_attrs;
 331 #endif
 332
 333         /* The command line arguments (may be mangled).  People like
 334            keeping pointers to this stuff */
 335         char *args;
 336
 337 #ifdef CONFIG_SMP
 338         /* Per-cpu data. */
 339         void __percpu *percpu;
 340         unsigned int percpu_size;
 341 #endif
 342
 343 #ifdef CONFIG_TRACEPOINTS
 344         unsigned int num_tracepoints;
 345         struct tracepoint * const *tracepoints_ptrs;
 346 #endif
 347 #ifdef HAVE_JUMP_LABEL
 348         struct jump_entry *jump_entries;
 349         unsigned int num_jump_entries;
 350 #endif
 351 #ifdef CONFIG_TRACING
 352         unsigned int num_trace_bprintk_fmt;
 353         const char **trace_bprintk_fmt_start;
 354 #endif
 355 #ifdef CONFIG_EVENT_TRACING
 356         struct ftrace_event_call **trace_events;
 357         unsigned int num_trace_events;
 358 #endif
 359 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
 360         unsigned int num_ftrace_callsites;
 361         unsigned long *ftrace_callsites;
 362 #endif
 363
 364 #ifdef CONFIG_MODULE_UNLOAD
 365         /* What modules depend on me? */
 366         struct list_head source_list;
 367         /* What modules do I depend on? */
 368         struct list_head target_list;
 369
 370         /* Destruction function. */
 371         void (*exit)(void);
 372
 373         struct module_ref __percpu *refptr;
 374 #endif
 375
 376 #ifdef CONFIG_CONSTRUCTORS
 377         /* Constructor functions. */
 378         ctor_fn_t *ctors;
 379         unsigned int num_ctors;
 380 #endif
 381 };
 382 #ifndef MODULE_ARCH_INIT
 383 #define MODULE_ARCH_INIT {}
 384 #endif
 385
 386 extern struct mutex module_mutex;
 387
 388 /* FIXME: It'd be nice to isolate modules during init, too, so they
 389    aren't used before they (may) fail.  But presently too much code
 390    (IDE & SCSI) require entry into the module during init.*/
 391 static inline int module_is_live(struct module *mod)
 392 {
 393         return mod->state != MODULE_STATE_GOING;
 394 }
 395
 396 struct module *__module_text_address(unsigned long addr);
 397 struct module *__module_address(unsigned long addr);
 398 bool is_module_address(unsigned long addr);
 399 bool is_module_percpu_address(unsigned long addr);
 400 bool is_module_text_address(unsigned long addr);
 401
 402 static inline int within_module_core(unsigned long addr, const struct module *mod)
 403 {
 404         return (unsigned long)mod->module_core <= addr &&
 405                addr < (unsigned long)mod->module_core + mod->core_size;
 406 }
 407
 408 static inline int within_module_init(unsigned long addr, const struct module *mod)
 409 {
 410         return (unsigned long)mod->module_init <= addr &&
 411                addr < (unsigned long)mod->module_init + mod->init_size;
 412 }
 413
 414 /* Search for module by name: must hold module_mutex. */
 415 struct module *find_module(const char *name);
 416
 417 struct symsearch {
 418         const struct kernel_symbol *start, *stop;
 419         const unsigned long *crcs;
 420         enum {
 421                 NOT_GPL_ONLY,
 422                 GPL_ONLY,
 423                 WILL_BE_GPL_ONLY,
 424         } licence;
 425         bool unused;
 426 };
 427
 428 /* Search for an exported symbol by name. */
 429 const struct kernel_symbol *find_symbol(const char *name,
 430                                         struct module **owner,
 431                                         const unsigned long **crc,
 432                                         bool gplok,
 433                                         bool warn);
 434
 435 /* Walk the exported symbol table */
 436 bool each_symbol_section(bool (*fn)(const struct symsearch *arr,
 437                                     struct module *owner,
 438                                     void *data), void *data);
 439
 440 /* Returns 0 and fills in value, defined and namebuf, or -ERANGE if
 441    symnum out of range. */
 442 int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
 443                         char *name, char *module_name, int *exported);
 444
 445 /* Look for this name: can be of form module:name. */
 446 unsigned long module_kallsyms_lookup_name(const char *name);
 447
 448 int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
 449                                              struct module *, unsigned long),
 450                                    void *data);
 451
 452 extern void __module_put_and_exit(struct module *mod, long code)
 453         __attribute__((noreturn));
 454 #define module_put_and_exit(code) __module_put_and_exit(THIS_MODULE, code)
 455
 456 #ifdef CONFIG_MODULE_UNLOAD
 457 unsigned long module_refcount(struct module *mod);
 458 void __symbol_put(const char *symbol);
 459 #define symbol_put(x) __symbol_put(VMLINUX_SYMBOL_STR(x))
 460 void symbol_put_addr(void *addr);
 461
 462 /* Sometimes we know we already have a refcount, and it's easier not
 463    to handle the error case (which only happens with rmmod --wait). */
 464 extern void __module_get(struct module *module);
 465
 466 /* This is the Right Way to get a module: if it fails, it's being removed,
 467  * so pretend it's not there. */
 468 extern bool try_module_get(struct module *module);
 469
 470 extern void module_put(struct module *module);
 471
 472 #else /*!CONFIG_MODULE_UNLOAD*/
 473 static inline int try_module_get(struct module *module)
 474 {
 475         return !module || module_is_live(module);
 476 }
 477 static inline void module_put(struct module *module)
 478 {
 479 }
 480 static inline void __module_get(struct module *module)
 481 {
 482 }
 483 #define symbol_put(x) do { } while (0)
 484 #define symbol_put_addr(p) do { } while (0)
 485
 486 #endif /* CONFIG_MODULE_UNLOAD */
 487 int ref_module(struct module *a, struct module *b);
 488
 489 /* This is a #define so the string doesn't get put in every .o file */
 490 #define module_name(mod)                        \
 491 ({                                              \
 492         struct module *__mod = (mod);           \
 493         __mod ? __mod->name : "kernel";         \
 494 })
 495
 496 /* For kallsyms to ask for address resolution.  namebuf should be at
 497  * least KSYM_NAME_LEN long: a pointer to namebuf is returned if
 498  * found, otherwise NULL. */
 499 const char *module_address_lookup(unsigned long addr,
 500                             unsigned long *symbolsize,
 501                             unsigned long *offset,
 502                             char **modname,
 503                             char *namebuf);
 504 int lookup_module_symbol_name(unsigned long addr, char *symname);
 505 int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name);
 506
 507 /* For extable.c to search modules' exception tables. */
 508 const struct exception_table_entry *search_module_extables(unsigned long addr);
 509
 510 int register_module_notifier(struct notifier_block *nb);
 511 int unregister_module_notifier(struct notifier_block *nb);
 512
 513 extern void print_modules(void);
 514
 515 #else /* !CONFIG_MODULES... */
 516
 517 /* Given an address, look for it in the exception tables. */
 518 static inline const struct exception_table_entry *
 519 search_module_extables(unsigned long addr)
 520 {
 521         return NULL;
 522 }
 523
 524 static inline struct module *__module_address(unsigned long addr)
 525 {
 526         return NULL;
 527 }
 528
 529 static inline struct module *__module_text_address(unsigned long addr)
 530 {
 531         return NULL;
 532 }
 533
 534 static inline bool is_module_address(unsigned long addr)
 535 {
 536         return false;
 537 }
 538
 539 static inline bool is_module_percpu_address(unsigned long addr)
 540 {
 541         return false;
 542 }
 543
 544 static inline bool is_module_text_address(unsigned long addr)
 545 {
 546         return false;
 547 }
 548
 549 /* Get/put a kernel symbol (calls should be symmetric) */
 550 #define symbol_get(x) ({ extern typeof(x) x __attribute__((weak)); &(x); })
 551 #define symbol_put(x) do { } while (0)
 552 #define symbol_put_addr(x) do { } while (0)
 553
 554 static inline void __module_get(struct module *module)
 555 {
 556 }
 557
 558 static inline int try_module_get(struct module *module)
 559 {
 560         return 1;
 561 }
 562
 563 static inline void module_put(struct module *module)
 564 {
 565 }
 566
 567 #define module_name(mod) "kernel"
 568
 569 /* For kallsyms to ask for address resolution.  NULL means not found. */
 570 static inline const char *module_address_lookup(unsigned long addr,
 571                                           unsigned long *symbolsize,
 572                                           unsigned long *offset,
 573                                           char **modname,
 574                                           char *namebuf)
 575 {
 576         return NULL;
 577 }
 578
 579 static inline int lookup_module_symbol_name(unsigned long addr, char *symname)
 580 {
 581         return -ERANGE;
 582 }
 583
 584 static inline int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name)
 585 {
 586         return -ERANGE;
 587 }
 588
 589 static inline int module_get_kallsym(unsigned int symnum, unsigned long *value,
 590                                         char *type, char *name,
 591                                         char *module_name, int *exported)
 592 {
 593         return -ERANGE;
 594 }
 595
 596 static inline unsigned long module_kallsyms_lookup_name(const char *name)
 597 {
 598         return 0;
 599 }
 600
 601 static inline int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
 602                                                            struct module *,
 603                                                            unsigned long),
 604                                                  void *data)
 605 {
 606         return 0;
 607 }
 608
 609 static inline int register_module_notifier(struct notifier_block *nb)
 610 {
 611         /* no events will happen anyway, so this can always succeed */
 612         return 0;
 613 }
 614
 615 static inline int unregister_module_notifier(struct notifier_block *nb)
 616 {
 617         return 0;
 618 }
 619
 620 #define module_put_and_exit(code) do_exit(code)
 621
 622 static inline void print_modules(void)
 623 {
 624 }
 625 #endif /* CONFIG_MODULES */
 626
 627 #ifdef CONFIG_SYSFS
 628 extern struct kset *module_kset;
 629 extern struct kobj_type module_ktype;
 630 extern int module_sysfs_initialized;
 631 #endif /* CONFIG_SYSFS */
 632
 633 #define symbol_request(x) try_then_request_module(symbol_get(x), "symbol:" #x)
 634
 635 /* BELOW HERE ALL THESE ARE OBSOLETE AND WILL VANISH */
 636
 637 #define __MODULE_STRING(x) __stringify(x)
 638
 639 #ifdef CONFIG_DEBUG_SET_MODULE_RONX
 640 extern void set_all_modules_text_rw(void);
 641 extern void set_all_modules_text_ro(void);
 642 #else
 643 static inline void set_all_modules_text_rw(void) { }
 644 static inline void set_all_modules_text_ro(void) { }
 645 #endif
 646
 647 #ifdef CONFIG_GENERIC_BUG
 648 void module_bug_finalize(const Elf_Ehdr *, const Elf_Shdr *,
 649                          struct module *);
 650 void module_bug_cleanup(struct module *);
 651
 652 #else   /* !CONFIG_GENERIC_BUG */
 653
 654 static inline void module_bug_finalize(const Elf_Ehdr *hdr,
 655                                         const Elf_Shdr *sechdrs,
 656                                         struct module *mod)
 657 {
 658 }
 659 static inline void module_bug_cleanup(struct module *mod) {}
 660 #endif  /* CONFIG_GENERIC_BUG */
 661
 662 #endif /* _LINUX_MODULE_H */