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         struct completion *kobj_completion;
  46 };
  47
  48 struct module_attribute {
  49         struct attribute attr;
  50         ssize_t (*show)(struct module_attribute *, struct module_kobject *,
  51                         char *);
  52         ssize_t (*store)(struct module_attribute *, struct module_kobject *,
  53                          const char *, size_t count);
  54         void (*setup)(struct module *, const char *);
  55         int (*test)(struct module *);
  56         void (*free)(struct module *);
  57 };
  58
  59 struct module_version_attribute {
  60         struct module_attribute mattr;
  61         const char *module_name;
  62         const char *version;
  63 } __attribute__ ((__aligned__(sizeof(void *))));
  64
  65 extern ssize_t __modver_version_show(struct module_attribute *,
  66                                      struct module_kobject *, char *);
  67
  68 extern struct module_attribute module_uevent;
  69
  70 /* These are either module local, or the kernel's dummy ones. */
  71 extern int init_module(void);
  72 extern void cleanup_module(void);
  73
  74 /* Archs provide a method of finding the correct exception table. */
  75 struct exception_table_entry;
  76
  77 const struct exception_table_entry *
  78 search_extable(const struct exception_table_entry *first,
  79                const struct exception_table_entry *last,
  80                unsigned long value);
  81 void sort_extable(struct exception_table_entry *start,
  82                   struct exception_table_entry *finish);
  83 void sort_main_extable(void);
  84 void trim_init_extable(struct module *m);
  85
  86 #ifdef MODULE
  87 #define MODULE_GENERIC_TABLE(gtype,name)                        \
  88 extern const struct gtype##_id __mod_##gtype##_table            \
  89   __attribute__ ((unused, alias(__stringify(name))))
  90
  91 #else  /* !MODULE */
  92 #define MODULE_GENERIC_TABLE(gtype,name)
  93 #endif
  94
  95 /* Generic info of form tag = "info" */
  96 #define MODULE_INFO(tag, info) __MODULE_INFO(tag, tag, info)
  97
  98 /* For userspace: you can also call me... */
  99 #define MODULE_ALIAS(_alias) MODULE_INFO(alias, _alias)
 100
 101 /* Soft module dependencies. See man modprobe.d for details.
 102  * Example: MODULE_SOFTDEP("pre: module-foo module-bar post: module-baz")
 103  */
 104 #define MODULE_SOFTDEP(_softdep) MODULE_INFO(softdep, _softdep)
 105
 106 /*
 107  * The following license idents are currently accepted as indicating free
 108  * software modules
 109  *
 110  *      "GPL"                           [GNU Public License v2 or later]
 111  *      "GPL v2"                        [GNU Public License v2]
 112  *      "GPL and additional rights"     [GNU Public License v2 rights and more]
 113  *      "Dual BSD/GPL"                  [GNU Public License v2
 114  *                                       or BSD license choice]
 115  *      "Dual MIT/GPL"                  [GNU Public License v2
 116  *                                       or MIT license choice]
 117  *      "Dual MPL/GPL"                  [GNU Public License v2
 118  *                                       or Mozilla license choice]
 119  *
 120  * The following other idents are available
 121  *
 122  *      "Proprietary"                   [Non free products]
 123  *
 124  * There are dual licensed components, but when running with Linux it is the
 125  * GPL that is relevant so this is a non issue. Similarly LGPL linked with GPL
 126  * is a GPL combined work.
 127  *
 128  * This exists for several reasons
 129  * 1.   So modinfo can show license info for users wanting to vet their setup
 130  *      is free
 131  * 2.   So the community can ignore bug reports including proprietary modules
 132  * 3.   So vendors can do likewise based on their own policies
 133  */
 134 #define MODULE_LICENSE(_license) MODULE_INFO(license, _license)
 135
 136 /*
 137  * Author(s), use "Name <email>" or just "Name", for multiple
 138  * authors use multiple MODULE_AUTHOR() statements/lines.
 139  */
 140 #define MODULE_AUTHOR(_author) MODULE_INFO(author, _author)
 141
 142 /* What your module does. */
 143 #define MODULE_DESCRIPTION(_description) MODULE_INFO(description, _description)
 144
 145 #define MODULE_DEVICE_TABLE(type,name)          \
 146   MODULE_GENERIC_TABLE(type##_device,name)
 147
 148 /* Version of form [<epoch>:]<version>[-<extra-version>].
 149    Or for CVS/RCS ID version, everything but the number is stripped.
 150   <epoch>: A (small) unsigned integer which allows you to start versions
 151            anew. If not mentioned, it's zero.  eg. "2:1.0" is after
 152            "1:2.0".
 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   <extraversion>: Like <version>, but inserted for local
 157            customizations, eg "rh3" or "rusty1".
 158
 159   Using this automatically adds a checksum of the .c files and the
 160   local headers in "srcversion".
 161 */
 162
 163 #if defined(MODULE) || !defined(CONFIG_SYSFS)
 164 #define MODULE_VERSION(_version) MODULE_INFO(version, _version)
 165 #else
 166 #define MODULE_VERSION(_version)                                        \
 167         static struct module_version_attribute ___modver_attr = {       \
 168                 .mattr  = {                                             \
 169                         .attr   = {                                     \
 170                                 .name   = "version",                    \
 171                                 .mode   = S_IRUGO,                      \
 172                         },                                              \
 173                         .show   = __modver_version_show,                \
 174                 },                                                      \
 175                 .module_name    = KBUILD_MODNAME,                       \
 176                 .version        = _version,                             \
 177         };                                                              \
 178         static const struct module_version_attribute                    \
 179         __used __attribute__ ((__section__ ("__modver")))               \
 180         * __moduleparam_const __modver_attr = &___modver_attr
 181 #endif
 182
 183 /* Optional firmware file (or files) needed by the module
 184  * format is simply firmware file name.  Multiple firmware
 185  * files require multiple MODULE_FIRMWARE() specifiers */
 186 #define MODULE_FIRMWARE(_firmware) MODULE_INFO(firmware, _firmware)
 187
 188 /* Given an address, look for it in the exception tables */
 189 const struct exception_table_entry *search_exception_tables(unsigned long add);
 190
 191 struct notifier_block;
 192
 193 #ifdef CONFIG_MODULES
 194
 195 extern int modules_disabled; /* for sysctl */
 196 /* Get/put a kernel symbol (calls must be symmetric) */
 197 void *__symbol_get(const char *symbol);
 198 void *__symbol_get_gpl(const char *symbol);
 199 #define symbol_get(x) ((typeof(&x))(__symbol_get(VMLINUX_SYMBOL_STR(x))))
 200
 201 /* modules using other modules: kdb wants to see this. */
 202 struct module_use {
 203         struct list_head source_list;
 204         struct list_head target_list;
 205         struct module *source, *target;
 206 };
 207
 208 enum module_state {
 209         MODULE_STATE_LIVE,      /* Normal state. */
 210         MODULE_STATE_COMING,    /* Full formed, running module_init. */
 211         MODULE_STATE_GOING,     /* Going away. */
 212         MODULE_STATE_UNFORMED,  /* Still setting it up. */
 213 };
 214
 215 /**
 216  * struct module_ref - per cpu module reference counts
 217  * @incs: number of module get on this cpu
 218  * @decs: number of module put on this cpu
 219  *
 220  * We force an alignment on 8 or 16 bytes, so that alloc_percpu()
 221  * put @incs/@decs in same cache line, with no extra memory cost,
 222  * since alloc_percpu() is fine grained.
 223  */
 224 struct module_ref {
 225         unsigned long incs;
 226         unsigned long decs;
 227 } __attribute((aligned(2 * sizeof(unsigned long))));
 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         /*
 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         /* Who is waiting for us to be unloaded */
 371         struct task_struct *waiter;
 372
 373         /* Destruction function. */
 374         void (*exit)(void);
 375
 376         struct module_ref __percpu *refptr;
 377 #endif
 378
 379 #ifdef CONFIG_CONSTRUCTORS
 380         /* Constructor functions. */
 381         ctor_fn_t *ctors;
 382         unsigned int num_ctors;
 383 #endif
 384 };
 385 #ifndef MODULE_ARCH_INIT
 386 #define MODULE_ARCH_INIT {}
 387 #endif
 388
 389 extern struct mutex module_mutex;
 390
 391 /* FIXME: It'd be nice to isolate modules during init, too, so they
 392    aren't used before they (may) fail.  But presently too much code
 393    (IDE & SCSI) require entry into the module during init.*/
 394 static inline int module_is_live(struct module *mod)
 395 {
 396         return mod->state != MODULE_STATE_GOING;
 397 }
 398
 399 struct module *__module_text_address(unsigned long addr);
 400 struct module *__module_address(unsigned long addr);
 401 bool is_module_address(unsigned long addr);
 402 bool is_module_percpu_address(unsigned long addr);
 403 bool is_module_text_address(unsigned long addr);
 404
 405 static inline int within_module_core(unsigned long addr, const struct module *mod)
 406 {
 407         return (unsigned long)mod->module_core <= addr &&
 408                addr < (unsigned long)mod->module_core + mod->core_size;
 409 }
 410
 411 static inline int within_module_init(unsigned long addr, const struct module *mod)
 412 {
 413         return (unsigned long)mod->module_init <= addr &&
 414                addr < (unsigned long)mod->module_init + mod->init_size;
 415 }
 416
 417 /* Search for module by name: must hold module_mutex. */
 418 struct module *find_module(const char *name);
 419
 420 struct symsearch {
 421         const struct kernel_symbol *start, *stop;
 422         const unsigned long *crcs;
 423         enum {
 424                 NOT_GPL_ONLY,
 425                 GPL_ONLY,
 426                 WILL_BE_GPL_ONLY,
 427         } licence;
 428         bool unused;
 429 };
 430
 431 /* Search for an exported symbol by name. */
 432 const struct kernel_symbol *find_symbol(const char *name,
 433                                         struct module **owner,
 434                                         const unsigned long **crc,
 435                                         bool gplok,
 436                                         bool warn);
 437
 438 /* Walk the exported symbol table */
 439 bool each_symbol_section(bool (*fn)(const struct symsearch *arr,
 440                                     struct module *owner,
 441                                     void *data), void *data);
 442
 443 /* Returns 0 and fills in value, defined and namebuf, or -ERANGE if
 444    symnum out of range. */
 445 int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
 446                         char *name, char *module_name, int *exported);
 447
 448 /* Look for this name: can be of form module:name. */
 449 unsigned long module_kallsyms_lookup_name(const char *name);
 450
 451 int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
 452                                              struct module *, unsigned long),
 453                                    void *data);
 454
 455 extern void __module_put_and_exit(struct module *mod, long code)
 456         __attribute__((noreturn));
 457 #define module_put_and_exit(code) __module_put_and_exit(THIS_MODULE, code);
 458
 459 #ifdef CONFIG_MODULE_UNLOAD
 460 unsigned long module_refcount(struct module *mod);
 461 void __symbol_put(const char *symbol);
 462 #define symbol_put(x) __symbol_put(VMLINUX_SYMBOL_STR(x))
 463 void symbol_put_addr(void *addr);
 464
 465 /* Sometimes we know we already have a refcount, and it's easier not
 466    to handle the error case (which only happens with rmmod --wait). */
 467 extern void __module_get(struct module *module);
 468
 469 /* This is the Right Way to get a module: if it fails, it's being removed,
 470  * so pretend it's not there. */
 471 extern bool try_module_get(struct module *module);
 472
 473 extern void module_put(struct module *module);
 474
 475 #else /*!CONFIG_MODULE_UNLOAD*/
 476 static inline int try_module_get(struct module *module)
 477 {
 478         return !module || module_is_live(module);
 479 }
 480 static inline void module_put(struct module *module)
 481 {
 482 }
 483 static inline void __module_get(struct module *module)
 484 {
 485 }
 486 #define symbol_put(x) do { } while(0)
 487 #define symbol_put_addr(p) do { } while(0)
 488
 489 #endif /* CONFIG_MODULE_UNLOAD */
 490 int ref_module(struct module *a, struct module *b);
 491
 492 /* This is a #define so the string doesn't get put in every .o file */
 493 #define module_name(mod)                        \
 494 ({                                              \
 495         struct module *__mod = (mod);           \
 496         __mod ? __mod->name : "kernel";         \
 497 })
 498
 499 /* For kallsyms to ask for address resolution.  namebuf should be at
 500  * least KSYM_NAME_LEN long: a pointer to namebuf is returned if
 501  * found, otherwise NULL. */
 502 const char *module_address_lookup(unsigned long addr,
 503                             unsigned long *symbolsize,
 504                             unsigned long *offset,
 505                             char **modname,
 506                             char *namebuf);
 507 int lookup_module_symbol_name(unsigned long addr, char *symname);
 508 int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name);
 509
 510 /* For extable.c to search modules' exception tables. */
 511 const struct exception_table_entry *search_module_extables(unsigned long addr);
 512
 513 int register_module_notifier(struct notifier_block * nb);
 514 int unregister_module_notifier(struct notifier_block * nb);
 515
 516 extern void print_modules(void);
 517
 518 #else /* !CONFIG_MODULES... */
 519
 520 /* Given an address, look for it in the exception tables. */
 521 static inline const struct exception_table_entry *
 522 search_module_extables(unsigned long addr)
 523 {
 524         return NULL;
 525 }
 526
 527 static inline struct module *__module_address(unsigned long addr)
 528 {
 529         return NULL;
 530 }
 531
 532 static inline struct module *__module_text_address(unsigned long addr)
 533 {
 534         return NULL;
 535 }
 536
 537 static inline bool is_module_address(unsigned long addr)
 538 {
 539         return false;
 540 }
 541
 542 static inline bool is_module_percpu_address(unsigned long addr)
 543 {
 544         return false;
 545 }
 546
 547 static inline bool is_module_text_address(unsigned long addr)
 548 {
 549         return false;
 550 }
 551
 552 /* Get/put a kernel symbol (calls should be symmetric) */
 553 #define symbol_get(x) ({ extern typeof(x) x __attribute__((weak)); &(x); })
 554 #define symbol_put(x) do { } while(0)
 555 #define symbol_put_addr(x) do { } while(0)
 556
 557 static inline void __module_get(struct module *module)
 558 {
 559 }
 560
 561 static inline int try_module_get(struct module *module)
 562 {
 563         return 1;
 564 }
 565
 566 static inline void module_put(struct module *module)
 567 {
 568 }
 569
 570 #define module_name(mod) "kernel"
 571
 572 /* For kallsyms to ask for address resolution.  NULL means not found. */
 573 static inline const char *module_address_lookup(unsigned long addr,
 574                                           unsigned long *symbolsize,
 575                                           unsigned long *offset,
 576                                           char **modname,
 577                                           char *namebuf)
 578 {
 579         return NULL;
 580 }
 581
 582 static inline int lookup_module_symbol_name(unsigned long addr, char *symname)
 583 {
 584         return -ERANGE;
 585 }
 586
 587 static inline int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name)
 588 {
 589         return -ERANGE;
 590 }
 591
 592 static inline int module_get_kallsym(unsigned int symnum, unsigned long *value,
 593                                         char *type, char *name,
 594                                         char *module_name, int *exported)
 595 {
 596         return -ERANGE;
 597 }
 598
 599 static inline unsigned long module_kallsyms_lookup_name(const char *name)
 600 {
 601         return 0;
 602 }
 603
 604 static inline int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
 605                                                            struct module *,
 606                                                            unsigned long),
 607                                                  void *data)
 608 {
 609         return 0;
 610 }
 611
 612 static inline int register_module_notifier(struct notifier_block * nb)
 613 {
 614         /* no events will happen anyway, so this can always succeed */
 615         return 0;
 616 }
 617
 618 static inline int unregister_module_notifier(struct notifier_block * nb)
 619 {
 620         return 0;
 621 }
 622
 623 #define module_put_and_exit(code) do_exit(code)
 624
 625 static inline void print_modules(void)
 626 {
 627 }
 628 #endif /* CONFIG_MODULES */
 629
 630 #ifdef CONFIG_SYSFS
 631 extern struct kset *module_kset;
 632 extern struct kobj_type module_ktype;
 633 extern int module_sysfs_initialized;
 634 #endif /* CONFIG_SYSFS */
 635
 636 #define symbol_request(x) try_then_request_module(symbol_get(x), "symbol:" #x)
 637
 638 /* BELOW HERE ALL THESE ARE OBSOLETE AND WILL VANISH */
 639
 640 #define __MODULE_STRING(x) __stringify(x)
 641
 642 #ifdef CONFIG_DEBUG_SET_MODULE_RONX
 643 extern void set_all_modules_text_rw(void);
 644 extern void set_all_modules_text_ro(void);
 645 #else
 646 static inline void set_all_modules_text_rw(void) { }
 647 static inline void set_all_modules_text_ro(void) { }
 648 #endif
 649
 650 #ifdef CONFIG_GENERIC_BUG
 651 void module_bug_finalize(const Elf_Ehdr *, const Elf_Shdr *,
 652                          struct module *);
 653 void module_bug_cleanup(struct module *);
 654
 655 #else   /* !CONFIG_GENERIC_BUG */
 656
 657 static inline void module_bug_finalize(const Elf_Ehdr *hdr,
 658                                         const Elf_Shdr *sechdrs,
 659                                         struct module *mod)
 660 {
 661 }
 662 static inline void module_bug_cleanup(struct module *mod) {}
 663 #endif  /* CONFIG_GENERIC_BUG */
 664
 665 #endif /* _LINUX_MODULE_H */