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 mod_kallsyms {
 224         Elf_Sym *symtab;
 225         unsigned int num_symtab;
 226         char *strtab;
 227 };
 228
 229 struct module
 230 {
 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         /* Protected by RCU and/or module_mutex: use rcu_dereference() */
 318         struct mod_kallsyms *kallsyms;
 319         struct mod_kallsyms core_kallsyms;
 320
 321         /* Section attributes */
 322         struct module_sect_attrs *sect_attrs;
 323
 324         /* Notes attributes */
 325         struct module_notes_attrs *notes_attrs;
 326 #endif
 327
 328         /* The command line arguments (may be mangled).  People like
 329            keeping pointers to this stuff */
 330         char *args;
 331
 332 #ifdef CONFIG_SMP
 333         /* Per-cpu data. */
 334         void __percpu *percpu;
 335         unsigned int percpu_size;
 336 #endif
 337
 338 #ifdef CONFIG_TRACEPOINTS
 339         unsigned int num_tracepoints;
 340         struct tracepoint * const *tracepoints_ptrs;
 341 #endif
 342 #ifdef HAVE_JUMP_LABEL
 343         struct jump_entry *jump_entries;
 344         unsigned int num_jump_entries;
 345 #endif
 346 #ifdef CONFIG_TRACING
 347         unsigned int num_trace_bprintk_fmt;
 348         const char **trace_bprintk_fmt_start;
 349 #endif
 350 #ifdef CONFIG_EVENT_TRACING
 351         struct ftrace_event_call **trace_events;
 352         unsigned int num_trace_events;
 353 #endif
 354 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
 355         unsigned int num_ftrace_callsites;
 356         unsigned long *ftrace_callsites;
 357 #endif
 358
 359 #ifdef CONFIG_MODULE_UNLOAD
 360         /* What modules depend on me? */
 361         struct list_head source_list;
 362         /* What modules do I depend on? */
 363         struct list_head target_list;
 364
 365         /* Who is waiting for us to be unloaded */
 366         struct task_struct *waiter;
 367
 368         /* Destruction function. */
 369         void (*exit)(void);
 370
 371         struct module_ref __percpu *refptr;
 372 #endif
 373
 374 #ifdef CONFIG_CONSTRUCTORS
 375         /* Constructor functions. */
 376         ctor_fn_t *ctors;
 377         unsigned int num_ctors;
 378 #endif
 379 };
 380 #ifndef MODULE_ARCH_INIT
 381 #define MODULE_ARCH_INIT {}
 382 #endif
 383
 384 extern struct mutex module_mutex;
 385
 386 /* FIXME: It'd be nice to isolate modules during init, too, so they
 387    aren't used before they (may) fail.  But presently too much code
 388    (IDE & SCSI) require entry into the module during init.*/
 389 static inline int module_is_live(struct module *mod)
 390 {
 391         return mod->state != MODULE_STATE_GOING;
 392 }
 393
 394 struct module *__module_text_address(unsigned long addr);
 395 struct module *__module_address(unsigned long addr);
 396 bool is_module_address(unsigned long addr);
 397 bool is_module_percpu_address(unsigned long addr);
 398 bool is_module_text_address(unsigned long addr);
 399
 400 static inline int within_module_core(unsigned long addr, const struct module *mod)
 401 {
 402         return (unsigned long)mod->module_core <= addr &&
 403                addr < (unsigned long)mod->module_core + mod->core_size;
 404 }
 405
 406 static inline int within_module_init(unsigned long addr, const struct module *mod)
 407 {
 408         return (unsigned long)mod->module_init <= addr &&
 409                addr < (unsigned long)mod->module_init + mod->init_size;
 410 }
 411
 412 /* Search for module by name: must hold module_mutex. */
 413 struct module *find_module(const char *name);
 414
 415 struct symsearch {
 416         const struct kernel_symbol *start, *stop;
 417         const unsigned long *crcs;
 418         enum {
 419                 NOT_GPL_ONLY,
 420                 GPL_ONLY,
 421                 WILL_BE_GPL_ONLY,
 422         } licence;
 423         bool unused;
 424 };
 425
 426 /* Search for an exported symbol by name. */
 427 const struct kernel_symbol *find_symbol(const char *name,
 428                                         struct module **owner,
 429                                         const unsigned long **crc,
 430                                         bool gplok,
 431                                         bool warn);
 432
 433 /* Walk the exported symbol table */
 434 bool each_symbol_section(bool (*fn)(const struct symsearch *arr,
 435                                     struct module *owner,
 436                                     void *data), void *data);
 437
 438 /* Returns 0 and fills in value, defined and namebuf, or -ERANGE if
 439    symnum out of range. */
 440 int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
 441                         char *name, char *module_name, int *exported);
 442
 443 /* Look for this name: can be of form module:name. */
 444 unsigned long module_kallsyms_lookup_name(const char *name);
 445
 446 int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
 447                                              struct module *, unsigned long),
 448                                    void *data);
 449
 450 extern void __module_put_and_exit(struct module *mod, long code)
 451         __attribute__((noreturn));
 452 #define module_put_and_exit(code) __module_put_and_exit(THIS_MODULE, code);
 453
 454 #ifdef CONFIG_MODULE_UNLOAD
 455 unsigned long module_refcount(struct module *mod);
 456 void __symbol_put(const char *symbol);
 457 #define symbol_put(x) __symbol_put(VMLINUX_SYMBOL_STR(x))
 458 void symbol_put_addr(void *addr);
 459
 460 /* Sometimes we know we already have a refcount, and it's easier not
 461    to handle the error case (which only happens with rmmod --wait). */
 462 extern void __module_get(struct module *module);
 463
 464 /* This is the Right Way to get a module: if it fails, it's being removed,
 465  * so pretend it's not there. */
 466 extern bool try_module_get(struct module *module);
 467
 468 extern void module_put(struct module *module);
 469
 470 #else /*!CONFIG_MODULE_UNLOAD*/
 471 static inline int try_module_get(struct module *module)
 472 {
 473         return !module || module_is_live(module);
 474 }
 475 static inline void module_put(struct module *module)
 476 {
 477 }
 478 static inline void __module_get(struct module *module)
 479 {
 480 }
 481 #define symbol_put(x) do { } while(0)
 482 #define symbol_put_addr(p) do { } while(0)
 483
 484 #endif /* CONFIG_MODULE_UNLOAD */
 485 int ref_module(struct module *a, struct module *b);
 486
 487 /* This is a #define so the string doesn't get put in every .o file */
 488 #define module_name(mod)                        \
 489 ({                                              \
 490         struct module *__mod = (mod);           \
 491         __mod ? __mod->name : "kernel";         \
 492 })
 493
 494 /* For kallsyms to ask for address resolution.  namebuf should be at
 495  * least KSYM_NAME_LEN long: a pointer to namebuf is returned if
 496  * found, otherwise NULL. */
 497 const char *module_address_lookup(unsigned long addr,
 498                             unsigned long *symbolsize,
 499                             unsigned long *offset,
 500                             char **modname,
 501                             char *namebuf);
 502 int lookup_module_symbol_name(unsigned long addr, char *symname);
 503 int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name);
 504
 505 /* For extable.c to search modules' exception tables. */
 506 const struct exception_table_entry *search_module_extables(unsigned long addr);
 507
 508 int register_module_notifier(struct notifier_block * nb);
 509 int unregister_module_notifier(struct notifier_block * nb);
 510
 511 extern void print_modules(void);
 512
 513 #else /* !CONFIG_MODULES... */
 514
 515 /* Given an address, look for it in the exception tables. */
 516 static inline const struct exception_table_entry *
 517 search_module_extables(unsigned long addr)
 518 {
 519         return NULL;
 520 }
 521
 522 static inline struct module *__module_address(unsigned long addr)
 523 {
 524         return NULL;
 525 }
 526
 527 static inline struct module *__module_text_address(unsigned long addr)
 528 {
 529         return NULL;
 530 }
 531
 532 static inline bool is_module_address(unsigned long addr)
 533 {
 534         return false;
 535 }
 536
 537 static inline bool is_module_percpu_address(unsigned long addr)
 538 {
 539         return false;
 540 }
 541
 542 static inline bool is_module_text_address(unsigned long addr)
 543 {
 544         return false;
 545 }
 546
 547 /* Get/put a kernel symbol (calls should be symmetric) */
 548 #define symbol_get(x) ({ extern typeof(x) x __attribute__((weak)); &(x); })
 549 #define symbol_put(x) do { } while(0)
 550 #define symbol_put_addr(x) do { } while(0)
 551
 552 static inline void __module_get(struct module *module)
 553 {
 554 }
 555
 556 static inline int try_module_get(struct module *module)
 557 {
 558         return 1;
 559 }
 560
 561 static inline void module_put(struct module *module)
 562 {
 563 }
 564
 565 #define module_name(mod) "kernel"
 566
 567 /* For kallsyms to ask for address resolution.  NULL means not found. */
 568 static inline const char *module_address_lookup(unsigned long addr,
 569                                           unsigned long *symbolsize,
 570                                           unsigned long *offset,
 571                                           char **modname,
 572                                           char *namebuf)
 573 {
 574         return NULL;
 575 }
 576
 577 static inline int lookup_module_symbol_name(unsigned long addr, char *symname)
 578 {
 579         return -ERANGE;
 580 }
 581
 582 static inline int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name)
 583 {
 584         return -ERANGE;
 585 }
 586
 587 static inline int module_get_kallsym(unsigned int symnum, unsigned long *value,
 588                                         char *type, char *name,
 589                                         char *module_name, int *exported)
 590 {
 591         return -ERANGE;
 592 }
 593
 594 static inline unsigned long module_kallsyms_lookup_name(const char *name)
 595 {
 596         return 0;
 597 }
 598
 599 static inline int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
 600                                                            struct module *,
 601                                                            unsigned long),
 602                                                  void *data)
 603 {
 604         return 0;
 605 }
 606
 607 static inline int register_module_notifier(struct notifier_block * nb)
 608 {
 609         /* no events will happen anyway, so this can always succeed */
 610         return 0;
 611 }
 612
 613 static inline int unregister_module_notifier(struct notifier_block * nb)
 614 {
 615         return 0;
 616 }
 617
 618 #define module_put_and_exit(code) do_exit(code)
 619
 620 static inline void print_modules(void)
 621 {
 622 }
 623 #endif /* CONFIG_MODULES */
 624
 625 #ifdef CONFIG_SYSFS
 626 extern struct kset *module_kset;
 627 extern struct kobj_type module_ktype;
 628 extern int module_sysfs_initialized;
 629 #endif /* CONFIG_SYSFS */
 630
 631 #define symbol_request(x) try_then_request_module(symbol_get(x), "symbol:" #x)
 632
 633 /* BELOW HERE ALL THESE ARE OBSOLETE AND WILL VANISH */
 634
 635 #define __MODULE_STRING(x) __stringify(x)
 636
 637 #ifdef CONFIG_DEBUG_SET_MODULE_RONX
 638 extern void set_all_modules_text_rw(void);
 639 extern void set_all_modules_text_ro(void);
 640 #else
 641 static inline void set_all_modules_text_rw(void) { }
 642 static inline void set_all_modules_text_ro(void) { }
 643 #endif
 644
 645 #ifdef CONFIG_GENERIC_BUG
 646 void module_bug_finalize(const Elf_Ehdr *, const Elf_Shdr *,
 647                          struct module *);
 648 void module_bug_cleanup(struct module *);
 649
 650 #else   /* !CONFIG_GENERIC_BUG */
 651
 652 static inline void module_bug_finalize(const Elf_Ehdr *hdr,
 653                                         const Elf_Shdr *sechdrs,
 654                                         struct module *mod)
 655 {
 656 }
 657 static inline void module_bug_cleanup(struct module *mod) {}
 658 #endif  /* CONFIG_GENERIC_BUG */
 659
 660 #endif /* _LINUX_MODULE_H */