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 /* Not Yet Implemented */
  25 #define MODULE_SUPPORTED_DEVICE(name)
  26
  27 #define MODULE_NAME_LEN MAX_PARAM_PREFIX_LEN
  28
  29 struct modversion_info
  30 {
  31         unsigned long crc;
  32         char name[MODULE_NAME_LEN];
  33 };
  34
  35 struct module;
  36
  37 struct module_kobject {
  38         struct kobject kobj;
  39         struct module *mod;
  40         struct kobject *drivers_dir;
  41         struct module_param_attrs *mp;
  42 };
  43
  44 struct module_attribute {
  45         struct attribute attr;
  46         ssize_t (*show)(struct module_attribute *, struct module_kobject *,
  47                         char *);
  48         ssize_t (*store)(struct module_attribute *, struct module_kobject *,
  49                          const char *, size_t count);
  50         void (*setup)(struct module *, const char *);
  51         int (*test)(struct module *);
  52         void (*free)(struct module *);
  53 };
  54
  55 struct module_version_attribute {
  56         struct module_attribute mattr;
  57         const char *module_name;
  58         const char *version;
  59 } __attribute__ ((__aligned__(sizeof(void *))));
  60
  61 extern ssize_t __modver_version_show(struct module_attribute *,
  62                                      struct module_kobject *, char *);
  63
  64 extern struct module_attribute module_uevent;
  65
  66 /* These are either module local, or the kernel's dummy ones. */
  67 extern int init_module(void);
  68 extern void cleanup_module(void);
  69
  70 /* Archs provide a method of finding the correct exception table. */
  71 struct exception_table_entry;
  72
  73 const struct exception_table_entry *
  74 search_extable(const struct exception_table_entry *first,
  75                const struct exception_table_entry *last,
  76                unsigned long value);
  77 void sort_extable(struct exception_table_entry *start,
  78                   struct exception_table_entry *finish);
  79 void sort_main_extable(void);
  80 void trim_init_extable(struct module *m);
  81
  82 #ifdef MODULE
  83 #define MODULE_GENERIC_TABLE(gtype,name)                        \
  84 extern const struct gtype##_id __mod_##gtype##_table            \
  85   __attribute__ ((unused, alias(__stringify(name))))
  86
  87 #else  /* !MODULE */
  88 #define MODULE_GENERIC_TABLE(gtype,name)
  89 #endif
  90
  91 /* Generic info of form tag = "info" */
  92 #define MODULE_INFO(tag, info) __MODULE_INFO(tag, tag, info)
  93
  94 /* For userspace: you can also call me... */
  95 #define MODULE_ALIAS(_alias) MODULE_INFO(alias, _alias)
  96
  97 /*
  98  * The following license idents are currently accepted as indicating free
  99  * software modules
 100  *
 101  *      "GPL"                           [GNU Public License v2 or later]
 102  *      "GPL v2"                        [GNU Public License v2]
 103  *      "GPL and additional rights"     [GNU Public License v2 rights and more]
 104  *      "Dual BSD/GPL"                  [GNU Public License v2
 105  *                                       or BSD license choice]
 106  *      "Dual MIT/GPL"                  [GNU Public License v2
 107  *                                       or MIT license choice]
 108  *      "Dual MPL/GPL"                  [GNU Public License v2
 109  *                                       or Mozilla license choice]
 110  *
 111  * The following other idents are available
 112  *
 113  *      "Proprietary"                   [Non free products]
 114  *
 115  * There are dual licensed components, but when running with Linux it is the
 116  * GPL that is relevant so this is a non issue. Similarly LGPL linked with GPL
 117  * is a GPL combined work.
 118  *
 119  * This exists for several reasons
 120  * 1.   So modinfo can show license info for users wanting to vet their setup
 121  *      is free
 122  * 2.   So the community can ignore bug reports including proprietary modules
 123  * 3.   So vendors can do likewise based on their own policies
 124  */
 125 #define MODULE_LICENSE(_license) MODULE_INFO(license, _license)
 126
 127 /*
 128  * Author(s), use "Name <email>" or just "Name", for multiple
 129  * authors use multiple MODULE_AUTHOR() statements/lines.
 130  */
 131 #define MODULE_AUTHOR(_author) MODULE_INFO(author, _author)
 132
 133 /* What your module does. */
 134 #define MODULE_DESCRIPTION(_description) MODULE_INFO(description, _description)
 135
 136 #define MODULE_DEVICE_TABLE(type,name)          \
 137   MODULE_GENERIC_TABLE(type##_device,name)
 138
 139 /* Version of form [<epoch>:]<version>[-<extra-version>].
 140    Or for CVS/RCS ID version, everything but the number is stripped.
 141   <epoch>: A (small) unsigned integer which allows you to start versions
 142            anew. If not mentioned, it's zero.  eg. "2:1.0" is after
 143            "1:2.0".
 144   <version>: The <version> may contain only alphanumerics and the
 145            character `.'.  Ordered by numeric sort for numeric parts,
 146            ascii sort for ascii parts (as per RPM or DEB algorithm).
 147   <extraversion>: Like <version>, but inserted for local
 148            customizations, eg "rh3" or "rusty1".
 149
 150   Using this automatically adds a checksum of the .c files and the
 151   local headers in "srcversion".
 152 */
 153
 154 #if defined(MODULE) || !defined(CONFIG_SYSFS)
 155 #define MODULE_VERSION(_version) MODULE_INFO(version, _version)
 156 #else
 157 #define MODULE_VERSION(_version)                                        \
 158         static struct module_version_attribute ___modver_attr = {       \
 159                 .mattr  = {                                             \
 160                         .attr   = {                                     \
 161                                 .name   = "version",                    \
 162                                 .mode   = S_IRUGO,                      \
 163                         },                                              \
 164                         .show   = __modver_version_show,                \
 165                 },                                                      \
 166                 .module_name    = KBUILD_MODNAME,                       \
 167                 .version        = _version,                             \
 168         };                                                              \
 169         static const struct module_version_attribute                    \
 170         __used __attribute__ ((__section__ ("__modver")))               \
 171         * __moduleparam_const __modver_attr = &___modver_attr
 172 #endif
 173
 174 /* Optional firmware file (or files) needed by the module
 175  * format is simply firmware file name.  Multiple firmware
 176  * files require multiple MODULE_FIRMWARE() specifiers */
 177 #define MODULE_FIRMWARE(_firmware) MODULE_INFO(firmware, _firmware)
 178
 179 /* Given an address, look for it in the exception tables */
 180 const struct exception_table_entry *search_exception_tables(unsigned long add);
 181
 182 struct notifier_block;
 183
 184 #ifdef CONFIG_MODULES
 185
 186 extern int modules_disabled; /* for sysctl */
 187 /* Get/put a kernel symbol (calls must be symmetric) */
 188 void *__symbol_get(const char *symbol);
 189 void *__symbol_get_gpl(const char *symbol);
 190 #define symbol_get(x) ((typeof(&x))(__symbol_get(MODULE_SYMBOL_PREFIX #x)))
 191
 192 /* modules using other modules: kdb wants to see this. */
 193 struct module_use {
 194         struct list_head source_list;
 195         struct list_head target_list;
 196         struct module *source, *target;
 197 };
 198
 199 enum module_state
 200 {
 201         MODULE_STATE_LIVE,
 202         MODULE_STATE_COMING,
 203         MODULE_STATE_GOING,
 204 };
 205
 206 /**
 207  * struct module_ref - per cpu module reference counts
 208  * @incs: number of module get on this cpu
 209  * @decs: number of module put on this cpu
 210  *
 211  * We force an alignment on 8 or 16 bytes, so that alloc_percpu()
 212  * put @incs/@decs in same cache line, with no extra memory cost,
 213  * since alloc_percpu() is fine grained.
 214  */
 215 struct module_ref {
 216         unsigned long incs;
 217         unsigned long decs;
 218 } __attribute((aligned(2 * sizeof(unsigned long))));
 219
 220 struct module
 221 {
 222         enum module_state state;
 223
 224         /* Member of list of modules */
 225         struct list_head list;
 226
 227         /* Unique handle for this module */
 228         char name[MODULE_NAME_LEN];
 229
 230         /* Sysfs stuff. */
 231         struct module_kobject mkobj;
 232         struct module_attribute *modinfo_attrs;
 233         const char *version;
 234         const char *srcversion;
 235         struct kobject *holders_dir;
 236
 237         /* Exported symbols */
 238         const struct kernel_symbol *syms;
 239         const unsigned long *crcs;
 240         unsigned int num_syms;
 241
 242         /* Kernel parameters. */
 243         struct kernel_param *kp;
 244         unsigned int num_kp;
 245
 246         /* GPL-only exported symbols. */
 247         unsigned int num_gpl_syms;
 248         const struct kernel_symbol *gpl_syms;
 249         const unsigned long *gpl_crcs;
 250
 251 #ifdef CONFIG_UNUSED_SYMBOLS
 252         /* unused exported symbols. */
 253         const struct kernel_symbol *unused_syms;
 254         const unsigned long *unused_crcs;
 255         unsigned int num_unused_syms;
 256
 257         /* GPL-only, unused exported symbols. */
 258         unsigned int num_unused_gpl_syms;
 259         const struct kernel_symbol *unused_gpl_syms;
 260         const unsigned long *unused_gpl_crcs;
 261 #endif
 262
 263         /* symbols that will be GPL-only in the near future. */
 264         const struct kernel_symbol *gpl_future_syms;
 265         const unsigned long *gpl_future_crcs;
 266         unsigned int num_gpl_future_syms;
 267
 268         /* Exception table */
 269         unsigned int num_exentries;
 270         struct exception_table_entry *extable;
 271
 272         /* Startup function. */
 273         int (*init)(void);
 274
 275         /* If this is non-NULL, vfree after init() returns */
 276         void *module_init;
 277
 278         /* Here is the actual code + data, vfree'd on unload. */
 279         void *module_core;
 280
 281         /* Here are the sizes of the init and core sections */
 282         unsigned int init_size, core_size;
 283
 284         /* The size of the executable code in each section.  */
 285         unsigned int init_text_size, core_text_size;
 286
 287         /* Size of RO sections of the module (text+rodata) */
 288         unsigned int init_ro_size, core_ro_size;
 289
 290         /* Arch-specific module values */
 291         struct mod_arch_specific arch;
 292
 293         unsigned int taints;    /* same bits as kernel:tainted */
 294
 295 #ifdef CONFIG_GENERIC_BUG
 296         /* Support for BUG */
 297         unsigned num_bugs;
 298         struct list_head bug_list;
 299         struct bug_entry *bug_table;
 300 #endif
 301
 302 #ifdef CONFIG_KALLSYMS
 303         /*
 304          * We keep the symbol and string tables for kallsyms.
 305          * The core_* fields below are temporary, loader-only (they
 306          * could really be discarded after module init).
 307          */
 308         Elf_Sym *symtab, *core_symtab;
 309         unsigned int num_symtab, core_num_syms;
 310         char *strtab, *core_strtab;
 311
 312         /* Section attributes */
 313         struct module_sect_attrs *sect_attrs;
 314
 315         /* Notes attributes */
 316         struct module_notes_attrs *notes_attrs;
 317 #endif
 318
 319         /* The command line arguments (may be mangled).  People like
 320            keeping pointers to this stuff */
 321         char *args;
 322
 323 #ifdef CONFIG_SMP
 324         /* Per-cpu data. */
 325         void __percpu *percpu;
 326         unsigned int percpu_size;
 327 #endif
 328
 329 #ifdef CONFIG_TRACEPOINTS
 330         unsigned int num_tracepoints;
 331         struct tracepoint * const *tracepoints_ptrs;
 332 #endif
 333 #ifdef HAVE_JUMP_LABEL
 334         struct jump_entry *jump_entries;
 335         unsigned int num_jump_entries;
 336 #endif
 337 #ifdef CONFIG_TRACING
 338         unsigned int num_trace_bprintk_fmt;
 339         const char **trace_bprintk_fmt_start;
 340 #endif
 341 #ifdef CONFIG_EVENT_TRACING
 342         struct ftrace_event_call **trace_events;
 343         unsigned int num_trace_events;
 344 #endif
 345 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
 346         unsigned int num_ftrace_callsites;
 347         unsigned long *ftrace_callsites;
 348 #endif
 349
 350 #ifdef CONFIG_MODULE_UNLOAD
 351         /* What modules depend on me? */
 352         struct list_head source_list;
 353         /* What modules do I depend on? */
 354         struct list_head target_list;
 355
 356         /* Who is waiting for us to be unloaded */
 357         struct task_struct *waiter;
 358
 359         /* Destruction function. */
 360         void (*exit)(void);
 361
 362         struct module_ref __percpu *refptr;
 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 int within_module_core(unsigned long addr, struct module *mod)
 392 {
 393         return (unsigned long)mod->module_core <= addr &&
 394                addr < (unsigned long)mod->module_core + mod->core_size;
 395 }
 396
 397 static inline int within_module_init(unsigned long addr, struct module *mod)
 398 {
 399         return (unsigned long)mod->module_init <= addr &&
 400                addr < (unsigned long)mod->module_init + mod->init_size;
 401 }
 402
 403 /* Search for module by name: must hold module_mutex. */
 404 struct module *find_module(const char *name);
 405
 406 struct symsearch {
 407         const struct kernel_symbol *start, *stop;
 408         const unsigned long *crcs;
 409         enum {
 410                 NOT_GPL_ONLY,
 411                 GPL_ONLY,
 412                 WILL_BE_GPL_ONLY,
 413         } licence;
 414         bool unused;
 415 };
 416
 417 /* Search for an exported symbol by name. */
 418 const struct kernel_symbol *find_symbol(const char *name,
 419                                         struct module **owner,
 420                                         const unsigned long **crc,
 421                                         bool gplok,
 422                                         bool warn);
 423
 424 /* Walk the exported symbol table */
 425 bool each_symbol_section(bool (*fn)(const struct symsearch *arr,
 426                                     struct module *owner,
 427                                     void *data), void *data);
 428
 429 /* Returns 0 and fills in value, defined and namebuf, or -ERANGE if
 430    symnum out of range. */
 431 int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
 432                         char *name, char *module_name, int *exported);
 433
 434 /* Look for this name: can be of form module:name. */
 435 unsigned long module_kallsyms_lookup_name(const char *name);
 436
 437 int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
 438                                              struct module *, unsigned long),
 439                                    void *data);
 440
 441 extern void __module_put_and_exit(struct module *mod, long code)
 442         __attribute__((noreturn));
 443 #define module_put_and_exit(code) __module_put_and_exit(THIS_MODULE, code);
 444
 445 #ifdef CONFIG_MODULE_UNLOAD
 446 unsigned long module_refcount(struct module *mod);
 447 void __symbol_put(const char *symbol);
 448 #define symbol_put(x) __symbol_put(MODULE_SYMBOL_PREFIX #x)
 449 void symbol_put_addr(void *addr);
 450
 451 /* Sometimes we know we already have a refcount, and it's easier not
 452    to handle the error case (which only happens with rmmod --wait). */
 453 extern void __module_get(struct module *module);
 454
 455 /* This is the Right Way to get a module: if it fails, it's being removed,
 456  * so pretend it's not there. */
 457 extern bool try_module_get(struct module *module);
 458
 459 extern void module_put(struct module *module);
 460
 461 #else /*!CONFIG_MODULE_UNLOAD*/
 462 static inline int try_module_get(struct module *module)
 463 {
 464         return !module || module_is_live(module);
 465 }
 466 static inline void module_put(struct module *module)
 467 {
 468 }
 469 static inline void __module_get(struct module *module)
 470 {
 471 }
 472 #define symbol_put(x) do { } while(0)
 473 #define symbol_put_addr(p) do { } while(0)
 474
 475 #endif /* CONFIG_MODULE_UNLOAD */
 476 int ref_module(struct module *a, struct module *b);
 477
 478 /* This is a #define so the string doesn't get put in every .o file */
 479 #define module_name(mod)                        \
 480 ({                                              \
 481         struct module *__mod = (mod);           \
 482         __mod ? __mod->name : "kernel";         \
 483 })
 484
 485 /* For kallsyms to ask for address resolution.  namebuf should be at
 486  * least KSYM_NAME_LEN long: a pointer to namebuf is returned if
 487  * found, otherwise NULL. */
 488 const char *module_address_lookup(unsigned long addr,
 489                             unsigned long *symbolsize,
 490                             unsigned long *offset,
 491                             char **modname,
 492                             char *namebuf);
 493 int lookup_module_symbol_name(unsigned long addr, char *symname);
 494 int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name);
 495
 496 /* For extable.c to search modules' exception tables. */
 497 const struct exception_table_entry *search_module_extables(unsigned long addr);
 498
 499 int register_module_notifier(struct notifier_block * nb);
 500 int unregister_module_notifier(struct notifier_block * nb);
 501
 502 extern void print_modules(void);
 503
 504 #else /* !CONFIG_MODULES... */
 505
 506 /* Given an address, look for it in the exception tables. */
 507 static inline const struct exception_table_entry *
 508 search_module_extables(unsigned long addr)
 509 {
 510         return NULL;
 511 }
 512
 513 static inline struct module *__module_address(unsigned long addr)
 514 {
 515         return NULL;
 516 }
 517
 518 static inline struct module *__module_text_address(unsigned long addr)
 519 {
 520         return NULL;
 521 }
 522
 523 static inline bool is_module_address(unsigned long addr)
 524 {
 525         return false;
 526 }
 527
 528 static inline bool is_module_percpu_address(unsigned long addr)
 529 {
 530         return false;
 531 }
 532
 533 static inline bool is_module_text_address(unsigned long addr)
 534 {
 535         return false;
 536 }
 537
 538 /* Get/put a kernel symbol (calls should be symmetric) */
 539 #define symbol_get(x) ({ extern typeof(x) x __attribute__((weak)); &(x); })
 540 #define symbol_put(x) do { } while(0)
 541 #define symbol_put_addr(x) do { } while(0)
 542
 543 static inline void __module_get(struct module *module)
 544 {
 545 }
 546
 547 static inline int try_module_get(struct module *module)
 548 {
 549         return 1;
 550 }
 551
 552 static inline void module_put(struct module *module)
 553 {
 554 }
 555
 556 #define module_name(mod) "kernel"
 557
 558 /* For kallsyms to ask for address resolution.  NULL means not found. */
 559 static inline const char *module_address_lookup(unsigned long addr,
 560                                           unsigned long *symbolsize,
 561                                           unsigned long *offset,
 562                                           char **modname,
 563                                           char *namebuf)
 564 {
 565         return NULL;
 566 }
 567
 568 static inline int lookup_module_symbol_name(unsigned long addr, char *symname)
 569 {
 570         return -ERANGE;
 571 }
 572
 573 static inline int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name)
 574 {
 575         return -ERANGE;
 576 }
 577
 578 static inline int module_get_kallsym(unsigned int symnum, unsigned long *value,
 579                                         char *type, char *name,
 580                                         char *module_name, int *exported)
 581 {
 582         return -ERANGE;
 583 }
 584
 585 static inline unsigned long module_kallsyms_lookup_name(const char *name)
 586 {
 587         return 0;
 588 }
 589
 590 static inline int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
 591                                                            struct module *,
 592                                                            unsigned long),
 593                                                  void *data)
 594 {
 595         return 0;
 596 }
 597
 598 static inline int register_module_notifier(struct notifier_block * nb)
 599 {
 600         /* no events will happen anyway, so this can always succeed */
 601         return 0;
 602 }
 603
 604 static inline int unregister_module_notifier(struct notifier_block * nb)
 605 {
 606         return 0;
 607 }
 608
 609 #define module_put_and_exit(code) do_exit(code)
 610
 611 static inline void print_modules(void)
 612 {
 613 }
 614 #endif /* CONFIG_MODULES */
 615
 616 #ifdef CONFIG_SYSFS
 617 extern struct kset *module_kset;
 618 extern struct kobj_type module_ktype;
 619 extern int module_sysfs_initialized;
 620 #endif /* CONFIG_SYSFS */
 621
 622 #define symbol_request(x) try_then_request_module(symbol_get(x), "symbol:" #x)
 623
 624 /* BELOW HERE ALL THESE ARE OBSOLETE AND WILL VANISH */
 625
 626 #define __MODULE_STRING(x) __stringify(x)
 627
 628 #ifdef CONFIG_DEBUG_SET_MODULE_RONX
 629 extern void set_all_modules_text_rw(void);
 630 extern void set_all_modules_text_ro(void);
 631 #else
 632 static inline void set_all_modules_text_rw(void) { }
 633 static inline void set_all_modules_text_ro(void) { }
 634 #endif
 635
 636 #ifdef CONFIG_GENERIC_BUG
 637 void module_bug_finalize(const Elf_Ehdr *, const Elf_Shdr *,
 638                          struct module *);
 639 void module_bug_cleanup(struct module *);
 640
 641 #else   /* !CONFIG_GENERIC_BUG */
 642
 643 static inline void module_bug_finalize(const Elf_Ehdr *hdr,
 644                                         const Elf_Shdr *sechdrs,
 645                                         struct module *mod)
 646 {
 647 }
 648 static inline void module_bug_cleanup(struct module *mod) {}
 649 #endif  /* CONFIG_GENERIC_BUG */
 650
 651 #endif /* _LINUX_MODULE_H */