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 {
  34         unsigned long crc;
  35         char name[MODULE_NAME_LEN];
  36 };
  37
  38 struct module;
  39
  40 struct module_kobject {
  41         struct kobject kobj;
  42         struct module *mod;
  43         struct kobject *drivers_dir;
  44         struct module_param_attrs *mp;
  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 /*
 101  * The following license idents are currently accepted as indicating free
 102  * software modules
 103  *
 104  *      "GPL"                           [GNU Public License v2 or later]
 105  *      "GPL v2"                        [GNU Public License v2]
 106  *      "GPL and additional rights"     [GNU Public License v2 rights and more]
 107  *      "Dual BSD/GPL"                  [GNU Public License v2
 108  *                                       or BSD license choice]
 109  *      "Dual MIT/GPL"                  [GNU Public License v2
 110  *                                       or MIT license choice]
 111  *      "Dual MPL/GPL"                  [GNU Public License v2
 112  *                                       or Mozilla license choice]
 113  *
 114  * The following other idents are available
 115  *
 116  *      "Proprietary"                   [Non free products]
 117  *
 118  * There are dual licensed components, but when running with Linux it is the
 119  * GPL that is relevant so this is a non issue. Similarly LGPL linked with GPL
 120  * is a GPL combined work.
 121  *
 122  * This exists for several reasons
 123  * 1.   So modinfo can show license info for users wanting to vet their setup
 124  *      is free
 125  * 2.   So the community can ignore bug reports including proprietary modules
 126  * 3.   So vendors can do likewise based on their own policies
 127  */
 128 #define MODULE_LICENSE(_license) MODULE_INFO(license, _license)
 129
 130 /*
 131  * Author(s), use "Name <email>" or just "Name", for multiple
 132  * authors use multiple MODULE_AUTHOR() statements/lines.
 133  */
 134 #define MODULE_AUTHOR(_author) MODULE_INFO(author, _author)
 135
 136 /* What your module does. */
 137 #define MODULE_DESCRIPTION(_description) MODULE_INFO(description, _description)
 138
 139 #define MODULE_DEVICE_TABLE(type,name)          \
 140   MODULE_GENERIC_TABLE(type##_device,name)
 141
 142 /* Version of form [<epoch>:]<version>[-<extra-version>].
 143    Or for CVS/RCS ID version, everything but the number is stripped.
 144   <epoch>: A (small) unsigned integer which allows you to start versions
 145            anew. If not mentioned, it's zero.  eg. "2:1.0" is after
 146            "1:2.0".
 147   <version>: The <version> may contain only alphanumerics and the
 148            character `.'.  Ordered by numeric sort for numeric parts,
 149            ascii sort for ascii parts (as per RPM or DEB algorithm).
 150   <extraversion>: Like <version>, but inserted for local
 151            customizations, eg "rh3" or "rusty1".
 152
 153   Using this automatically adds a checksum of the .c files and the
 154   local headers in "srcversion".
 155 */
 156
 157 #if defined(MODULE) || !defined(CONFIG_SYSFS)
 158 #define MODULE_VERSION(_version) MODULE_INFO(version, _version)
 159 #else
 160 #define MODULE_VERSION(_version)                                        \
 161         static struct module_version_attribute ___modver_attr = {       \
 162                 .mattr  = {                                             \
 163                         .attr   = {                                     \
 164                                 .name   = "version",                    \
 165                                 .mode   = S_IRUGO,                      \
 166                         },                                              \
 167                         .show   = __modver_version_show,                \
 168                 },                                                      \
 169                 .module_name    = KBUILD_MODNAME,                       \
 170                 .version        = _version,                             \
 171         };                                                              \
 172         static const struct module_version_attribute                    \
 173         __used __attribute__ ((__section__ ("__modver")))               \
 174         * __moduleparam_const __modver_attr = &___modver_attr
 175 #endif
 176
 177 /* Optional firmware file (or files) needed by the module
 178  * format is simply firmware file name.  Multiple firmware
 179  * files require multiple MODULE_FIRMWARE() specifiers */
 180 #define MODULE_FIRMWARE(_firmware) MODULE_INFO(firmware, _firmware)
 181
 182 /* Given an address, look for it in the exception tables */
 183 const struct exception_table_entry *search_exception_tables(unsigned long add);
 184
 185 struct notifier_block;
 186
 187 #ifdef CONFIG_MODULES
 188
 189 extern int modules_disabled; /* for sysctl */
 190 /* Get/put a kernel symbol (calls must be symmetric) */
 191 void *__symbol_get(const char *symbol);
 192 void *__symbol_get_gpl(const char *symbol);
 193 #define symbol_get(x) ((typeof(&x))(__symbol_get(VMLINUX_SYMBOL_STR(x))))
 194
 195 /* modules using other modules: kdb wants to see this. */
 196 struct module_use {
 197         struct list_head source_list;
 198         struct list_head target_list;
 199         struct module *source, *target;
 200 };
 201
 202 enum module_state {
 203         MODULE_STATE_LIVE,      /* Normal state. */
 204         MODULE_STATE_COMING,    /* Full formed, running module_init. */
 205         MODULE_STATE_GOING,     /* Going away. */
 206         MODULE_STATE_UNFORMED,  /* Still setting it up. */
 207 };
 208
 209 /**
 210  * struct module_ref - per cpu module reference counts
 211  * @incs: number of module get on this cpu
 212  * @decs: number of module put on this cpu
 213  *
 214  * We force an alignment on 8 or 16 bytes, so that alloc_percpu()
 215  * put @incs/@decs in same cache line, with no extra memory cost,
 216  * since alloc_percpu() is fine grained.
 217  */
 218 struct module_ref {
 219         unsigned long incs;
 220         unsigned long decs;
 221 } __attribute((aligned(2 * sizeof(unsigned long))));
 222
 223 struct module
 224 {
 225         enum module_state state;
 226
 227         /* Member of list of modules */
 228         struct list_head list;
 229
 230         /* Unique handle for this module */
 231         char name[MODULE_NAME_LEN];
 232
 233         /* Sysfs stuff. */
 234         struct module_kobject mkobj;
 235         struct module_attribute *modinfo_attrs;
 236         const char *version;
 237         const char *srcversion;
 238         struct kobject *holders_dir;
 239
 240         /* Exported symbols */
 241         const struct kernel_symbol *syms;
 242         const unsigned long *crcs;
 243         unsigned int num_syms;
 244
 245         /* Kernel parameters. */
 246         struct kernel_param *kp;
 247         unsigned int num_kp;
 248
 249         /* GPL-only exported symbols. */
 250         unsigned int num_gpl_syms;
 251         const struct kernel_symbol *gpl_syms;
 252         const unsigned long *gpl_crcs;
 253
 254 #ifdef CONFIG_UNUSED_SYMBOLS
 255         /* unused exported symbols. */
 256         const struct kernel_symbol *unused_syms;
 257         const unsigned long *unused_crcs;
 258         unsigned int num_unused_syms;
 259
 260         /* GPL-only, unused exported symbols. */
 261         unsigned int num_unused_gpl_syms;
 262         const struct kernel_symbol *unused_gpl_syms;
 263         const unsigned long *unused_gpl_crcs;
 264 #endif
 265
 266 #ifdef CONFIG_MODULE_SIG
 267         /* Signature was verified. */
 268         bool sig_ok;
 269 #endif
 270
 271         /* symbols that will be GPL-only in the near future. */
 272         const struct kernel_symbol *gpl_future_syms;
 273         const unsigned long *gpl_future_crcs;
 274         unsigned int num_gpl_future_syms;
 275
 276         /* Exception table */
 277         unsigned int num_exentries;
 278         struct exception_table_entry *extable;
 279
 280         /* Startup function. */
 281         int (*init)(void);
 282
 283         /* If this is non-NULL, vfree after init() returns */
 284         void *module_init;
 285
 286         /* Here is the actual code + data, vfree'd on unload. */
 287         void *module_core;
 288
 289         /* Here are the sizes of the init and core sections */
 290         unsigned int init_size, core_size;
 291
 292         /* The size of the executable code in each section.  */
 293         unsigned int init_text_size, core_text_size;
 294
 295         /* Size of RO sections of the module (text+rodata) */
 296         unsigned int init_ro_size, core_ro_size;
 297
 298         /* Arch-specific module values */
 299         struct mod_arch_specific arch;
 300
 301         unsigned int taints;    /* same bits as kernel:tainted */
 302
 303 #ifdef CONFIG_GENERIC_BUG
 304         /* Support for BUG */
 305         unsigned num_bugs;
 306         struct list_head bug_list;
 307         struct bug_entry *bug_table;
 308 #endif
 309
 310 #ifdef CONFIG_KALLSYMS
 311         /*
 312          * We keep the symbol and string tables for kallsyms.
 313          * The core_* fields below are temporary, loader-only (they
 314          * could really be discarded after module init).
 315          */
 316         Elf_Sym *symtab, *core_symtab;
 317         unsigned int num_symtab, core_num_syms;
 318         char *strtab, *core_strtab;
 319
 320         /* Section attributes */
 321         struct module_sect_attrs *sect_attrs;
 322
 323         /* Notes attributes */
 324         struct module_notes_attrs *notes_attrs;
 325 #endif
 326
 327         /* The command line arguments (may be mangled).  People like
 328            keeping pointers to this stuff */
 329         char *args;
 330
 331 #ifdef CONFIG_SMP
 332         /* Per-cpu data. */
 333         void __percpu *percpu;
 334         unsigned int percpu_size;
 335 #endif
 336
 337 #ifdef CONFIG_TRACEPOINTS
 338         unsigned int num_tracepoints;
 339         struct tracepoint * const *tracepoints_ptrs;
 340 #endif
 341 #ifdef HAVE_JUMP_LABEL
 342         struct jump_entry *jump_entries;
 343         unsigned int num_jump_entries;
 344 #endif
 345 #ifdef CONFIG_TRACING
 346         unsigned int num_trace_bprintk_fmt;
 347         const char **trace_bprintk_fmt_start;
 348 #endif
 349 #ifdef CONFIG_EVENT_TRACING
 350         struct ftrace_event_call **trace_events;
 351         unsigned int num_trace_events;
 352 #endif
 353 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
 354         unsigned int num_ftrace_callsites;
 355         unsigned long *ftrace_callsites;
 356 #endif
 357
 358 #ifdef CONFIG_MODULE_UNLOAD
 359         /* What modules depend on me? */
 360         struct list_head source_list;
 361         /* What modules do I depend on? */
 362         struct list_head target_list;
 363
 364         /* Who is waiting for us to be unloaded */
 365         struct task_struct *waiter;
 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 int within_module_core(unsigned long addr, const struct module *mod)
 400 {
 401         return (unsigned long)mod->module_core <= addr &&
 402                addr < (unsigned long)mod->module_core + mod->core_size;
 403 }
 404
 405 static inline int within_module_init(unsigned long addr, const struct module *mod)
 406 {
 407         return (unsigned long)mod->module_init <= addr &&
 408                addr < (unsigned long)mod->module_init + mod->init_size;
 409 }
 410
 411 /* Search for module by name: must hold module_mutex. */
 412 struct module *find_module(const char *name);
 413
 414 struct symsearch {
 415         const struct kernel_symbol *start, *stop;
 416         const unsigned long *crcs;
 417         enum {
 418                 NOT_GPL_ONLY,
 419                 GPL_ONLY,
 420                 WILL_BE_GPL_ONLY,
 421         } licence;
 422         bool unused;
 423 };
 424
 425 /* Search for an exported symbol by name. */
 426 const struct kernel_symbol *find_symbol(const char *name,
 427                                         struct module **owner,
 428                                         const unsigned long **crc,
 429                                         bool gplok,
 430                                         bool warn);
 431
 432 /* Walk the exported symbol table */
 433 bool each_symbol_section(bool (*fn)(const struct symsearch *arr,
 434                                     struct module *owner,
 435                                     void *data), void *data);
 436
 437 /* Returns 0 and fills in value, defined and namebuf, or -ERANGE if
 438    symnum out of range. */
 439 int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
 440                         char *name, char *module_name, int *exported);
 441
 442 /* Look for this name: can be of form module:name. */
 443 unsigned long module_kallsyms_lookup_name(const char *name);
 444
 445 int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
 446                                              struct module *, unsigned long),
 447                                    void *data);
 448
 449 extern void __module_put_and_exit(struct module *mod, long code)
 450         __attribute__((noreturn));
 451 #define module_put_and_exit(code) __module_put_and_exit(THIS_MODULE, code);
 452
 453 #ifdef CONFIG_MODULE_UNLOAD
 454 unsigned long module_refcount(struct module *mod);
 455 void __symbol_put(const char *symbol);
 456 #define symbol_put(x) __symbol_put(VMLINUX_SYMBOL_STR(x))
 457 void symbol_put_addr(void *addr);
 458
 459 /* Sometimes we know we already have a refcount, and it's easier not
 460    to handle the error case (which only happens with rmmod --wait). */
 461 extern void __module_get(struct module *module);
 462
 463 /* This is the Right Way to get a module: if it fails, it's being removed,
 464  * so pretend it's not there. */
 465 extern bool try_module_get(struct module *module);
 466
 467 extern void module_put(struct module *module);
 468
 469 #else /*!CONFIG_MODULE_UNLOAD*/
 470 static inline int try_module_get(struct module *module)
 471 {
 472         return !module || module_is_live(module);
 473 }
 474 static inline void module_put(struct module *module)
 475 {
 476 }
 477 static inline void __module_get(struct module *module)
 478 {
 479 }
 480 #define symbol_put(x) do { } while(0)
 481 #define symbol_put_addr(p) do { } while(0)
 482
 483 #endif /* CONFIG_MODULE_UNLOAD */
 484 int ref_module(struct module *a, struct module *b);
 485
 486 /* This is a #define so the string doesn't get put in every .o file */
 487 #define module_name(mod)                        \
 488 ({                                              \
 489         struct module *__mod = (mod);           \
 490         __mod ? __mod->name : "kernel";         \
 491 })
 492
 493 /* For kallsyms to ask for address resolution.  namebuf should be at
 494  * least KSYM_NAME_LEN long: a pointer to namebuf is returned if
 495  * found, otherwise NULL. */
 496 const char *module_address_lookup(unsigned long addr,
 497                             unsigned long *symbolsize,
 498                             unsigned long *offset,
 499                             char **modname,
 500                             char *namebuf);
 501 int lookup_module_symbol_name(unsigned long addr, char *symname);
 502 int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name);
 503
 504 /* For extable.c to search modules' exception tables. */
 505 const struct exception_table_entry *search_module_extables(unsigned long addr);
 506
 507 int register_module_notifier(struct notifier_block * nb);
 508 int unregister_module_notifier(struct notifier_block * nb);
 509
 510 extern void print_modules(void);
 511
 512 #else /* !CONFIG_MODULES... */
 513
 514 /* Given an address, look for it in the exception tables. */
 515 static inline const struct exception_table_entry *
 516 search_module_extables(unsigned long addr)
 517 {
 518         return NULL;
 519 }
 520
 521 static inline struct module *__module_address(unsigned long addr)
 522 {
 523         return NULL;
 524 }
 525
 526 static inline struct module *__module_text_address(unsigned long addr)
 527 {
 528         return NULL;
 529 }
 530
 531 static inline bool is_module_address(unsigned long addr)
 532 {
 533         return false;
 534 }
 535
 536 static inline bool is_module_percpu_address(unsigned long addr)
 537 {
 538         return false;
 539 }
 540
 541 static inline bool is_module_text_address(unsigned long addr)
 542 {
 543         return false;
 544 }
 545
 546 /* Get/put a kernel symbol (calls should be symmetric) */
 547 #define symbol_get(x) ({ extern typeof(x) x __attribute__((weak)); &(x); })
 548 #define symbol_put(x) do { } while(0)
 549 #define symbol_put_addr(x) do { } while(0)
 550
 551 static inline void __module_get(struct module *module)
 552 {
 553 }
 554
 555 static inline int try_module_get(struct module *module)
 556 {
 557         return 1;
 558 }
 559
 560 static inline void module_put(struct module *module)
 561 {
 562 }
 563
 564 #define module_name(mod) "kernel"
 565
 566 /* For kallsyms to ask for address resolution.  NULL means not found. */
 567 static inline const char *module_address_lookup(unsigned long addr,
 568                                           unsigned long *symbolsize,
 569                                           unsigned long *offset,
 570                                           char **modname,
 571                                           char *namebuf)
 572 {
 573         return NULL;
 574 }
 575
 576 static inline int lookup_module_symbol_name(unsigned long addr, char *symname)
 577 {
 578         return -ERANGE;
 579 }
 580
 581 static inline int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name)
 582 {
 583         return -ERANGE;
 584 }
 585
 586 static inline int module_get_kallsym(unsigned int symnum, unsigned long *value,
 587                                         char *type, char *name,
 588                                         char *module_name, int *exported)
 589 {
 590         return -ERANGE;
 591 }
 592
 593 static inline unsigned long module_kallsyms_lookup_name(const char *name)
 594 {
 595         return 0;
 596 }
 597
 598 static inline int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
 599                                                            struct module *,
 600                                                            unsigned long),
 601                                                  void *data)
 602 {
 603         return 0;
 604 }
 605
 606 static inline int register_module_notifier(struct notifier_block * nb)
 607 {
 608         /* no events will happen anyway, so this can always succeed */
 609         return 0;
 610 }
 611
 612 static inline int unregister_module_notifier(struct notifier_block * nb)
 613 {
 614         return 0;
 615 }
 616
 617 #define module_put_and_exit(code) do_exit(code)
 618
 619 static inline void print_modules(void)
 620 {
 621 }
 622 #endif /* CONFIG_MODULES */
 623
 624 #ifdef CONFIG_SYSFS
 625 extern struct kset *module_kset;
 626 extern struct kobj_type module_ktype;
 627 extern int module_sysfs_initialized;
 628 #endif /* CONFIG_SYSFS */
 629
 630 #define symbol_request(x) try_then_request_module(symbol_get(x), "symbol:" #x)
 631
 632 /* BELOW HERE ALL THESE ARE OBSOLETE AND WILL VANISH */
 633
 634 #define __MODULE_STRING(x) __stringify(x)
 635
 636 #ifdef CONFIG_DEBUG_SET_MODULE_RONX
 637 extern void set_all_modules_text_rw(void);
 638 extern void set_all_modules_text_ro(void);
 639 #else
 640 static inline void set_all_modules_text_rw(void) { }
 641 static inline void set_all_modules_text_ro(void) { }
 642 #endif
 643
 644 #ifdef CONFIG_GENERIC_BUG
 645 void module_bug_finalize(const Elf_Ehdr *, const Elf_Shdr *,
 646                          struct module *);
 647 void module_bug_cleanup(struct module *);
 648
 649 #else   /* !CONFIG_GENERIC_BUG */
 650
 651 static inline void module_bug_finalize(const Elf_Ehdr *hdr,
 652                                         const Elf_Shdr *sechdrs,
 653                                         struct module *mod)
 654 {
 655 }
 656 static inline void module_bug_cleanup(struct module *mod) {}
 657 #endif  /* CONFIG_GENERIC_BUG */
 658
 659 #endif /* _LINUX_MODULE_H */