1 /* SPDX-License-Identifier: GPL-2.0-only */ 2 /* 3 * Dynamic loading of modules into the kernel. 4 * 5 * Rewritten by Richard Henderson <[email protected]> Dec 1996 6 * Rewritten again by Rusty Russell, 2002 7 */ 8 9 #ifndef _LINUX_MODULE_H 10 #define _LINUX_MODULE_H 11 12 #include <linux/list.h> 13 #include <linux/stat.h> 14 #include <linux/buildid.h> 15 #include <linux/compiler.h> 16 #include <linux/cache.h> 17 #include <linux/kmod.h> 18 #include <linux/init.h> 19 #include <linux/elf.h> 20 #include <linux/stringify.h> 21 #include <linux/kobject.h> 22 #include <linux/moduleparam.h> 23 #include <linux/jump_label.h> 24 #include <linux/export.h> 25 #include <linux/rbtree_latch.h> 26 #include <linux/error-injection.h> 27 #include <linux/tracepoint-defs.h> 28 #include <linux/srcu.h> 29 #include <linux/static_call_types.h> 30 #include <linux/dynamic_debug.h> 31 32 #include <linux/percpu.h> 33 #include <asm/module.h> 34 35 #define MODULE_NAME_LEN MAX_PARAM_PREFIX_LEN 36 37 struct modversion_info { 38 unsigned long crc; 39 char name[MODULE_NAME_LEN]; 40 }; 41 42 struct module; 43 struct exception_table_entry; 44 45 struct module_kobject { 46 struct kobject kobj; 47 struct module *mod; 48 struct kobject *drivers_dir; 49 struct module_param_attrs *mp; 50 struct completion *kobj_completion; 51 } __randomize_layout; 52 53 struct module_attribute { 54 struct attribute attr; 55 ssize_t (*show)(const struct module_attribute *, struct module_kobject *, 56 char *); 57 ssize_t (*store)(const struct module_attribute *, struct module_kobject *, 58 const char *, size_t count); 59 void (*setup)(struct module *, const char *); 60 int (*test)(struct module *); 61 void (*free)(struct module *); 62 }; 63 64 struct module_version_attribute { 65 struct module_attribute mattr; 66 const char *module_name; 67 const char *version; 68 }; 69 70 extern ssize_t __modver_version_show(const struct module_attribute *, 71 struct module_kobject *, char *); 72 73 extern const struct module_attribute module_uevent; 74 75 /* These are either module local, or the kernel's dummy ones. */ 76 extern int init_module(void); 77 extern void cleanup_module(void); 78 79 #ifndef MODULE 80 /** 81 * module_init() - driver initialization entry point 82 * @x: function to be run at kernel boot time or module insertion 83 * 84 * module_init() will either be called during do_initcalls() (if 85 * builtin) or at module insertion time (if a module). There can only 86 * be one per module. 87 */ 88 #define module_init(x) __initcall(x); 89 90 /** 91 * module_exit() - driver exit entry point 92 * @x: function to be run when driver is removed 93 * 94 * module_exit() will wrap the driver clean-up code 95 * with cleanup_module() when used with rmmod when 96 * the driver is a module. If the driver is statically 97 * compiled into the kernel, module_exit() has no effect. 98 * There can only be one per module. 99 */ 100 #define module_exit(x) __exitcall(x); 101 102 #else /* MODULE */ 103 104 /* 105 * In most cases loadable modules do not need custom 106 * initcall levels. There are still some valid cases where 107 * a driver may be needed early if built in, and does not 108 * matter when built as a loadable module. Like bus 109 * snooping debug drivers. 110 */ 111 #define early_initcall(fn) module_init(fn) 112 #define core_initcall(fn) module_init(fn) 113 #define core_initcall_sync(fn) module_init(fn) 114 #define postcore_initcall(fn) module_init(fn) 115 #define postcore_initcall_sync(fn) module_init(fn) 116 #define arch_initcall(fn) module_init(fn) 117 #define subsys_initcall(fn) module_init(fn) 118 #define subsys_initcall_sync(fn) module_init(fn) 119 #define fs_initcall(fn) module_init(fn) 120 #define fs_initcall_sync(fn) module_init(fn) 121 #define rootfs_initcall(fn) module_init(fn) 122 #define device_initcall(fn) module_init(fn) 123 #define device_initcall_sync(fn) module_init(fn) 124 #define late_initcall(fn) module_init(fn) 125 #define late_initcall_sync(fn) module_init(fn) 126 127 #define console_initcall(fn) module_init(fn) 128 129 /* Each module must use one module_init(). */ 130 #define module_init(initfn) \ 131 static inline initcall_t __maybe_unused __inittest(void) \ 132 { return initfn; } \ 133 int init_module(void) __copy(initfn) \ 134 __attribute__((alias(#initfn))); \ 135 ___ADDRESSABLE(init_module, __initdata); 136 137 /* This is only required if you want to be unloadable. */ 138 #define module_exit(exitfn) \ 139 static inline exitcall_t __maybe_unused __exittest(void) \ 140 { return exitfn; } \ 141 void cleanup_module(void) __copy(exitfn) \ 142 __attribute__((alias(#exitfn))); \ 143 ___ADDRESSABLE(cleanup_module, __exitdata); 144 145 #endif 146 147 /* This means "can be init if no module support, otherwise module load 148 may call it." */ 149 #ifdef CONFIG_MODULES 150 #define __init_or_module 151 #define __initdata_or_module 152 #define __initconst_or_module 153 #define __INIT_OR_MODULE .text 154 #define __INITDATA_OR_MODULE .data 155 #define __INITRODATA_OR_MODULE .section ".rodata","a",%progbits 156 #else 157 #define __init_or_module __init 158 #define __initdata_or_module __initdata 159 #define __initconst_or_module __initconst 160 #define __INIT_OR_MODULE __INIT 161 #define __INITDATA_OR_MODULE __INITDATA 162 #define __INITRODATA_OR_MODULE __INITRODATA 163 #endif /*CONFIG_MODULES*/ 164 165 /* Generic info of form tag = "info" */ 166 #define MODULE_INFO(tag, info) __MODULE_INFO(tag, tag, info) 167 168 /* For userspace: you can also call me... */ 169 #define MODULE_ALIAS(_alias) MODULE_INFO(alias, _alias) 170 171 /* Soft module dependencies. See man modprobe.d for details. 172 * Example: MODULE_SOFTDEP("pre: module-foo module-bar post: module-baz") 173 */ 174 #define MODULE_SOFTDEP(_softdep) MODULE_INFO(softdep, _softdep) 175 176 /* 177 * Weak module dependencies. See man modprobe.d for details. 178 * Example: MODULE_WEAKDEP("module-foo") 179 */ 180 #define MODULE_WEAKDEP(_weakdep) MODULE_INFO(weakdep, _weakdep) 181 182 /* 183 * MODULE_FILE is used for generating modules.builtin 184 * So, make it no-op when this is being built as a module 185 */ 186 #ifdef MODULE 187 #define MODULE_FILE 188 #else 189 #define MODULE_FILE MODULE_INFO(file, KBUILD_MODFILE); 190 #endif 191 192 /* 193 * The following license idents are currently accepted as indicating free 194 * software modules 195 * 196 * "GPL" [GNU Public License v2] 197 * "GPL v2" [GNU Public License v2] 198 * "GPL and additional rights" [GNU Public License v2 rights and more] 199 * "Dual BSD/GPL" [GNU Public License v2 200 * or BSD license choice] 201 * "Dual MIT/GPL" [GNU Public License v2 202 * or MIT license choice] 203 * "Dual MPL/GPL" [GNU Public License v2 204 * or Mozilla license choice] 205 * 206 * The following other idents are available 207 * 208 * "Proprietary" [Non free products] 209 * 210 * Both "GPL v2" and "GPL" (the latter also in dual licensed strings) are 211 * merely stating that the module is licensed under the GPL v2, but are not 212 * telling whether "GPL v2 only" or "GPL v2 or later". The reason why there 213 * are two variants is a historic and failed attempt to convey more 214 * information in the MODULE_LICENSE string. For module loading the 215 * "only/or later" distinction is completely irrelevant and does neither 216 * replace the proper license identifiers in the corresponding source file 217 * nor amends them in any way. The sole purpose is to make the 218 * 'Proprietary' flagging work and to refuse to bind symbols which are 219 * exported with EXPORT_SYMBOL_GPL when a non free module is loaded. 220 * 221 * In the same way "BSD" is not a clear license information. It merely 222 * states, that the module is licensed under one of the compatible BSD 223 * license variants. The detailed and correct license information is again 224 * to be found in the corresponding source files. 225 * 226 * There are dual licensed components, but when running with Linux it is the 227 * GPL that is relevant so this is a non issue. Similarly LGPL linked with GPL 228 * is a GPL combined work. 229 * 230 * This exists for several reasons 231 * 1. So modinfo can show license info for users wanting to vet their setup 232 * is free 233 * 2. So the community can ignore bug reports including proprietary modules 234 * 3. So vendors can do likewise based on their own policies 235 */ 236 #define MODULE_LICENSE(_license) MODULE_FILE MODULE_INFO(license, _license) 237 238 /* 239 * Author(s), use "Name <email>" or just "Name", for multiple 240 * authors use multiple MODULE_AUTHOR() statements/lines. 241 */ 242 #define MODULE_AUTHOR(_author) MODULE_INFO(author, _author) 243 244 /* What your module does. */ 245 #define MODULE_DESCRIPTION(_description) MODULE_INFO(description, _description) 246 247 #ifdef MODULE 248 /* Creates an alias so file2alias.c can find device table. */ 249 #define MODULE_DEVICE_TABLE(type, name) \ 250 extern typeof(name) __mod_device_table__##type##__##name \ 251 __attribute__ ((unused, alias(__stringify(name)))) 252 #else /* !MODULE */ 253 #define MODULE_DEVICE_TABLE(type, name) 254 #endif 255 256 /* Version of form [<epoch>:]<version>[-<extra-version>]. 257 * Or for CVS/RCS ID version, everything but the number is stripped. 258 * <epoch>: A (small) unsigned integer which allows you to start versions 259 * anew. If not mentioned, it's zero. eg. "2:1.0" is after 260 * "1:2.0". 261 262 * <version>: The <version> may contain only alphanumerics and the 263 * character `.'. Ordered by numeric sort for numeric parts, 264 * ascii sort for ascii parts (as per RPM or DEB algorithm). 265 266 * <extraversion>: Like <version>, but inserted for local 267 * customizations, eg "rh3" or "rusty1". 268 269 * Using this automatically adds a checksum of the .c files and the 270 * local headers in "srcversion". 271 */ 272 273 #if defined(MODULE) || !defined(CONFIG_SYSFS) 274 #define MODULE_VERSION(_version) MODULE_INFO(version, _version) 275 #else 276 #define MODULE_VERSION(_version) \ 277 MODULE_INFO(version, _version); \ 278 static const struct module_version_attribute __modver_attr \ 279 __used __section("__modver") \ 280 __aligned(__alignof__(struct module_version_attribute)) \ 281 = { \ 282 .mattr = { \ 283 .attr = { \ 284 .name = "version", \ 285 .mode = S_IRUGO, \ 286 }, \ 287 .show = __modver_version_show, \ 288 }, \ 289 .module_name = KBUILD_MODNAME, \ 290 .version = _version, \ 291 } 292 #endif 293 294 /* Optional firmware file (or files) needed by the module 295 * format is simply firmware file name. Multiple firmware 296 * files require multiple MODULE_FIRMWARE() specifiers */ 297 #define MODULE_FIRMWARE(_firmware) MODULE_INFO(firmware, _firmware) 298 299 #define MODULE_IMPORT_NS(ns) MODULE_INFO(import_ns, ns) 300 301 struct notifier_block; 302 303 #ifdef CONFIG_MODULES 304 305 extern int modules_disabled; /* for sysctl */ 306 /* Get/put a kernel symbol (calls must be symmetric) */ 307 void *__symbol_get(const char *symbol); 308 void *__symbol_get_gpl(const char *symbol); 309 #define symbol_get(x) ((typeof(&x))(__symbol_get(__stringify(x)))) 310 311 /* modules using other modules: kdb wants to see this. */ 312 struct module_use { 313 struct list_head source_list; 314 struct list_head target_list; 315 struct module *source, *target; 316 }; 317 318 enum module_state { 319 MODULE_STATE_LIVE, /* Normal state. */ 320 MODULE_STATE_COMING, /* Full formed, running module_init. */ 321 MODULE_STATE_GOING, /* Going away. */ 322 MODULE_STATE_UNFORMED, /* Still setting it up. */ 323 }; 324 325 struct mod_tree_node { 326 struct module *mod; 327 struct latch_tree_node node; 328 }; 329 330 enum mod_mem_type { 331 MOD_TEXT = 0, 332 MOD_DATA, 333 MOD_RODATA, 334 MOD_RO_AFTER_INIT, 335 MOD_INIT_TEXT, 336 MOD_INIT_DATA, 337 MOD_INIT_RODATA, 338 339 MOD_MEM_NUM_TYPES, 340 MOD_INVALID = -1, 341 }; 342 343 #define mod_mem_type_is_init(type) \ 344 ((type) == MOD_INIT_TEXT || \ 345 (type) == MOD_INIT_DATA || \ 346 (type) == MOD_INIT_RODATA) 347 348 #define mod_mem_type_is_core(type) (!mod_mem_type_is_init(type)) 349 350 #define mod_mem_type_is_text(type) \ 351 ((type) == MOD_TEXT || \ 352 (type) == MOD_INIT_TEXT) 353 354 #define mod_mem_type_is_data(type) (!mod_mem_type_is_text(type)) 355 356 #define mod_mem_type_is_core_data(type) \ 357 (mod_mem_type_is_core(type) && \ 358 mod_mem_type_is_data(type)) 359 360 #define for_each_mod_mem_type(type) \ 361 for (enum mod_mem_type (type) = 0; \ 362 (type) < MOD_MEM_NUM_TYPES; (type)++) 363 364 #define for_class_mod_mem_type(type, class) \ 365 for_each_mod_mem_type(type) \ 366 if (mod_mem_type_is_##class(type)) 367 368 struct module_memory { 369 void *base; 370 bool is_rox; 371 unsigned int size; 372 373 #ifdef CONFIG_MODULES_TREE_LOOKUP 374 struct mod_tree_node mtn; 375 #endif 376 }; 377 378 #ifdef CONFIG_MODULES_TREE_LOOKUP 379 /* Only touch one cacheline for common rbtree-for-core-layout case. */ 380 #define __module_memory_align ____cacheline_aligned 381 #else 382 #define __module_memory_align 383 #endif 384 385 struct mod_kallsyms { 386 Elf_Sym *symtab; 387 unsigned int num_symtab; 388 char *strtab; 389 char *typetab; 390 }; 391 392 #ifdef CONFIG_LIVEPATCH 393 /** 394 * struct klp_modinfo - ELF information preserved from the livepatch module 395 * 396 * @hdr: ELF header 397 * @sechdrs: Section header table 398 * @secstrings: String table for the section headers 399 * @symndx: The symbol table section index 400 */ 401 struct klp_modinfo { 402 Elf_Ehdr hdr; 403 Elf_Shdr *sechdrs; 404 char *secstrings; 405 unsigned int symndx; 406 }; 407 #endif 408 409 struct module { 410 enum module_state state; 411 412 /* Member of list of modules */ 413 struct list_head list; 414 415 /* Unique handle for this module */ 416 char name[MODULE_NAME_LEN]; 417 418 #ifdef CONFIG_STACKTRACE_BUILD_ID 419 /* Module build ID */ 420 unsigned char build_id[BUILD_ID_SIZE_MAX]; 421 #endif 422 423 /* Sysfs stuff. */ 424 struct module_kobject mkobj; 425 struct module_attribute *modinfo_attrs; 426 const char *version; 427 const char *srcversion; 428 struct kobject *holders_dir; 429 430 /* Exported symbols */ 431 const struct kernel_symbol *syms; 432 const u32 *crcs; 433 unsigned int num_syms; 434 435 #ifdef CONFIG_ARCH_USES_CFI_TRAPS 436 s32 *kcfi_traps; 437 s32 *kcfi_traps_end; 438 #endif 439 440 /* Kernel parameters. */ 441 #ifdef CONFIG_SYSFS 442 struct mutex param_lock; 443 #endif 444 struct kernel_param *kp; 445 unsigned int num_kp; 446 447 /* GPL-only exported symbols. */ 448 unsigned int num_gpl_syms; 449 const struct kernel_symbol *gpl_syms; 450 const u32 *gpl_crcs; 451 bool using_gplonly_symbols; 452 453 #ifdef CONFIG_MODULE_SIG 454 /* Signature was verified. */ 455 bool sig_ok; 456 #endif 457 458 bool async_probe_requested; 459 460 /* Exception table */ 461 unsigned int num_exentries; 462 struct exception_table_entry *extable; 463 464 /* Startup function. */ 465 int (*init)(void); 466 467 struct module_memory mem[MOD_MEM_NUM_TYPES] __module_memory_align; 468 469 /* Arch-specific module values */ 470 struct mod_arch_specific arch; 471 472 unsigned long taints; /* same bits as kernel:taint_flags */ 473 474 #ifdef CONFIG_GENERIC_BUG 475 /* Support for BUG */ 476 unsigned num_bugs; 477 struct list_head bug_list; 478 struct bug_entry *bug_table; 479 #endif 480 481 #ifdef CONFIG_KALLSYMS 482 /* Protected by RCU and/or module_mutex: use rcu_dereference() */ 483 struct mod_kallsyms __rcu *kallsyms; 484 struct mod_kallsyms core_kallsyms; 485 486 /* Section attributes */ 487 struct module_sect_attrs *sect_attrs; 488 489 /* Notes attributes */ 490 struct module_notes_attrs *notes_attrs; 491 #endif 492 493 /* The command line arguments (may be mangled). People like 494 keeping pointers to this stuff */ 495 char *args; 496 497 #ifdef CONFIG_SMP 498 /* Per-cpu data. */ 499 void __percpu *percpu; 500 unsigned int percpu_size; 501 #endif 502 void *noinstr_text_start; 503 unsigned int noinstr_text_size; 504 505 #ifdef CONFIG_TRACEPOINTS 506 unsigned int num_tracepoints; 507 tracepoint_ptr_t *tracepoints_ptrs; 508 #endif 509 #ifdef CONFIG_TREE_SRCU 510 unsigned int num_srcu_structs; 511 struct srcu_struct **srcu_struct_ptrs; 512 #endif 513 #ifdef CONFIG_BPF_EVENTS 514 unsigned int num_bpf_raw_events; 515 struct bpf_raw_event_map *bpf_raw_events; 516 #endif 517 #ifdef CONFIG_DEBUG_INFO_BTF_MODULES 518 unsigned int btf_data_size; 519 unsigned int btf_base_data_size; 520 void *btf_data; 521 void *btf_base_data; 522 #endif 523 #ifdef CONFIG_JUMP_LABEL 524 struct jump_entry *jump_entries; 525 unsigned int num_jump_entries; 526 #endif 527 #ifdef CONFIG_TRACING 528 unsigned int num_trace_bprintk_fmt; 529 const char **trace_bprintk_fmt_start; 530 #endif 531 #ifdef CONFIG_EVENT_TRACING 532 struct trace_event_call **trace_events; 533 unsigned int num_trace_events; 534 struct trace_eval_map **trace_evals; 535 unsigned int num_trace_evals; 536 #endif 537 #ifdef CONFIG_FTRACE_MCOUNT_RECORD 538 unsigned int num_ftrace_callsites; 539 unsigned long *ftrace_callsites; 540 #endif 541 #ifdef CONFIG_KPROBES 542 void *kprobes_text_start; 543 unsigned int kprobes_text_size; 544 unsigned long *kprobe_blacklist; 545 unsigned int num_kprobe_blacklist; 546 #endif 547 #ifdef CONFIG_HAVE_STATIC_CALL_INLINE 548 int num_static_call_sites; 549 struct static_call_site *static_call_sites; 550 #endif 551 #if IS_ENABLED(CONFIG_KUNIT) 552 int num_kunit_init_suites; 553 struct kunit_suite **kunit_init_suites; 554 int num_kunit_suites; 555 struct kunit_suite **kunit_suites; 556 #endif 557 558 559 #ifdef CONFIG_LIVEPATCH 560 bool klp; /* Is this a livepatch module? */ 561 bool klp_alive; 562 563 /* ELF information */ 564 struct klp_modinfo *klp_info; 565 #endif 566 567 #ifdef CONFIG_PRINTK_INDEX 568 unsigned int printk_index_size; 569 struct pi_entry **printk_index_start; 570 #endif 571 572 #ifdef CONFIG_MODULE_UNLOAD 573 /* What modules depend on me? */ 574 struct list_head source_list; 575 /* What modules do I depend on? */ 576 struct list_head target_list; 577 578 /* Destruction function. */ 579 void (*exit)(void); 580 581 atomic_t refcnt; 582 #endif 583 584 #ifdef CONFIG_CONSTRUCTORS 585 /* Constructor functions. */ 586 ctor_fn_t *ctors; 587 unsigned int num_ctors; 588 #endif 589 590 #ifdef CONFIG_FUNCTION_ERROR_INJECTION 591 struct error_injection_entry *ei_funcs; 592 unsigned int num_ei_funcs; 593 #endif 594 #ifdef CONFIG_DYNAMIC_DEBUG_CORE 595 struct _ddebug_info dyndbg_info; 596 #endif 597 } ____cacheline_aligned __randomize_layout; 598 #ifndef MODULE_ARCH_INIT 599 #define MODULE_ARCH_INIT {} 600 #endif 601 602 #ifndef HAVE_ARCH_KALLSYMS_SYMBOL_VALUE 603 static inline unsigned long kallsyms_symbol_value(const Elf_Sym *sym) 604 { 605 return sym->st_value; 606 } 607 #endif 608 609 /* FIXME: It'd be nice to isolate modules during init, too, so they 610 aren't used before they (may) fail. But presently too much code 611 (IDE & SCSI) require entry into the module during init.*/ 612 static inline bool module_is_live(struct module *mod) 613 { 614 return mod->state != MODULE_STATE_GOING; 615 } 616 617 static inline bool module_is_coming(struct module *mod) 618 { 619 return mod->state == MODULE_STATE_COMING; 620 } 621 622 struct module *__module_text_address(unsigned long addr); 623 struct module *__module_address(unsigned long addr); 624 bool is_module_address(unsigned long addr); 625 bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr); 626 bool is_module_percpu_address(unsigned long addr); 627 bool is_module_text_address(unsigned long addr); 628 629 static inline bool within_module_mem_type(unsigned long addr, 630 const struct module *mod, 631 enum mod_mem_type type) 632 { 633 unsigned long base, size; 634 635 base = (unsigned long)mod->mem[type].base; 636 size = mod->mem[type].size; 637 return addr - base < size; 638 } 639 640 static inline bool within_module_core(unsigned long addr, 641 const struct module *mod) 642 { 643 for_class_mod_mem_type(type, core) { 644 if (within_module_mem_type(addr, mod, type)) 645 return true; 646 } 647 return false; 648 } 649 650 static inline bool within_module_init(unsigned long addr, 651 const struct module *mod) 652 { 653 for_class_mod_mem_type(type, init) { 654 if (within_module_mem_type(addr, mod, type)) 655 return true; 656 } 657 return false; 658 } 659 660 static inline bool within_module(unsigned long addr, const struct module *mod) 661 { 662 return within_module_init(addr, mod) || within_module_core(addr, mod); 663 } 664 665 /* Search for module by name: must be in a RCU-sched critical section. */ 666 struct module *find_module(const char *name); 667 668 extern void __noreturn __module_put_and_kthread_exit(struct module *mod, 669 long code); 670 #define module_put_and_kthread_exit(code) __module_put_and_kthread_exit(THIS_MODULE, code) 671 672 #ifdef CONFIG_MODULE_UNLOAD 673 int module_refcount(struct module *mod); 674 void __symbol_put(const char *symbol); 675 #define symbol_put(x) __symbol_put(__stringify(x)) 676 void symbol_put_addr(void *addr); 677 678 /* Sometimes we know we already have a refcount, and it's easier not 679 to handle the error case (which only happens with rmmod --wait). */ 680 extern void __module_get(struct module *module); 681 682 /** 683 * try_module_get() - take module refcount unless module is being removed 684 * @module: the module we should check for 685 * 686 * Only try to get a module reference count if the module is not being removed. 687 * This call will fail if the module is in the process of being removed. 688 * 689 * Care must also be taken to ensure the module exists and is alive prior to 690 * usage of this call. This can be gauranteed through two means: 691 * 692 * 1) Direct protection: you know an earlier caller must have increased the 693 * module reference through __module_get(). This can typically be achieved 694 * by having another entity other than the module itself increment the 695 * module reference count. 696 * 697 * 2) Implied protection: there is an implied protection against module 698 * removal. An example of this is the implied protection used by kernfs / 699 * sysfs. The sysfs store / read file operations are guaranteed to exist 700 * through the use of kernfs's active reference (see kernfs_active()) and a 701 * sysfs / kernfs file removal cannot happen unless the same file is not 702 * active. Therefore, if a sysfs file is being read or written to the module 703 * which created it must still exist. It is therefore safe to use 704 * try_module_get() on module sysfs store / read ops. 705 * 706 * One of the real values to try_module_get() is the module_is_live() check 707 * which ensures that the caller of try_module_get() can yield to userspace 708 * module removal requests and gracefully fail if the module is on its way out. 709 * 710 * Returns true if the reference count was successfully incremented. 711 */ 712 extern bool try_module_get(struct module *module); 713 714 /** 715 * module_put() - release a reference count to a module 716 * @module: the module we should release a reference count for 717 * 718 * If you successfully bump a reference count to a module with try_module_get(), 719 * when you are finished you must call module_put() to release that reference 720 * count. 721 */ 722 extern void module_put(struct module *module); 723 724 #else /*!CONFIG_MODULE_UNLOAD*/ 725 static inline bool try_module_get(struct module *module) 726 { 727 return !module || module_is_live(module); 728 } 729 static inline void module_put(struct module *module) 730 { 731 } 732 static inline void __module_get(struct module *module) 733 { 734 } 735 #define symbol_put(x) do { } while (0) 736 #define symbol_put_addr(p) do { } while (0) 737 738 #endif /* CONFIG_MODULE_UNLOAD */ 739 740 /* This is a #define so the string doesn't get put in every .o file */ 741 #define module_name(mod) \ 742 ({ \ 743 struct module *__mod = (mod); \ 744 __mod ? __mod->name : "kernel"; \ 745 }) 746 747 /* Dereference module function descriptor */ 748 void *dereference_module_function_descriptor(struct module *mod, void *ptr); 749 750 int register_module_notifier(struct notifier_block *nb); 751 int unregister_module_notifier(struct notifier_block *nb); 752 753 extern void print_modules(void); 754 755 static inline bool module_requested_async_probing(struct module *module) 756 { 757 return module && module->async_probe_requested; 758 } 759 760 static inline bool is_livepatch_module(struct module *mod) 761 { 762 #ifdef CONFIG_LIVEPATCH 763 return mod->klp; 764 #else 765 return false; 766 #endif 767 } 768 769 void set_module_sig_enforced(void); 770 771 static inline void *module_writable_address(struct module *mod, void *loc) 772 { 773 return loc; 774 } 775 776 #else /* !CONFIG_MODULES... */ 777 778 static inline struct module *__module_address(unsigned long addr) 779 { 780 return NULL; 781 } 782 783 static inline struct module *__module_text_address(unsigned long addr) 784 { 785 return NULL; 786 } 787 788 static inline bool is_module_address(unsigned long addr) 789 { 790 return false; 791 } 792 793 static inline bool is_module_percpu_address(unsigned long addr) 794 { 795 return false; 796 } 797 798 static inline bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr) 799 { 800 return false; 801 } 802 803 static inline bool is_module_text_address(unsigned long addr) 804 { 805 return false; 806 } 807 808 static inline bool within_module_core(unsigned long addr, 809 const struct module *mod) 810 { 811 return false; 812 } 813 814 static inline bool within_module_init(unsigned long addr, 815 const struct module *mod) 816 { 817 return false; 818 } 819 820 static inline bool within_module(unsigned long addr, const struct module *mod) 821 { 822 return false; 823 } 824 825 /* Get/put a kernel symbol (calls should be symmetric) */ 826 #define symbol_get(x) ({ extern typeof(x) x __attribute__((weak,visibility("hidden"))); &(x); }) 827 #define symbol_put(x) do { } while (0) 828 #define symbol_put_addr(x) do { } while (0) 829 830 static inline void __module_get(struct module *module) 831 { 832 } 833 834 static inline bool try_module_get(struct module *module) 835 { 836 return true; 837 } 838 839 static inline void module_put(struct module *module) 840 { 841 } 842 843 #define module_name(mod) "kernel" 844 845 static inline int register_module_notifier(struct notifier_block *nb) 846 { 847 /* no events will happen anyway, so this can always succeed */ 848 return 0; 849 } 850 851 static inline int unregister_module_notifier(struct notifier_block *nb) 852 { 853 return 0; 854 } 855 856 #define module_put_and_kthread_exit(code) kthread_exit(code) 857 858 static inline void print_modules(void) 859 { 860 } 861 862 static inline bool module_requested_async_probing(struct module *module) 863 { 864 return false; 865 } 866 867 868 static inline void set_module_sig_enforced(void) 869 { 870 } 871 872 /* Dereference module function descriptor */ 873 static inline 874 void *dereference_module_function_descriptor(struct module *mod, void *ptr) 875 { 876 return ptr; 877 } 878 879 static inline bool module_is_coming(struct module *mod) 880 { 881 return false; 882 } 883 884 static inline void *module_writable_address(struct module *mod, void *loc) 885 { 886 return loc; 887 } 888 #endif /* CONFIG_MODULES */ 889 890 #ifdef CONFIG_SYSFS 891 extern struct kset *module_kset; 892 extern const struct kobj_type module_ktype; 893 #endif /* CONFIG_SYSFS */ 894 895 #define symbol_request(x) try_then_request_module(symbol_get(x), "symbol:" #x) 896 897 /* BELOW HERE ALL THESE ARE OBSOLETE AND WILL VANISH */ 898 899 #define __MODULE_STRING(x) __stringify(x) 900 901 #ifdef CONFIG_GENERIC_BUG 902 void module_bug_finalize(const Elf_Ehdr *, const Elf_Shdr *, 903 struct module *); 904 void module_bug_cleanup(struct module *); 905 906 #else /* !CONFIG_GENERIC_BUG */ 907 908 static inline void module_bug_finalize(const Elf_Ehdr *hdr, 909 const Elf_Shdr *sechdrs, 910 struct module *mod) 911 { 912 } 913 static inline void module_bug_cleanup(struct module *mod) {} 914 #endif /* CONFIG_GENERIC_BUG */ 915 916 #ifdef CONFIG_MITIGATION_RETPOLINE 917 extern bool retpoline_module_ok(bool has_retpoline); 918 #else 919 static inline bool retpoline_module_ok(bool has_retpoline) 920 { 921 return true; 922 } 923 #endif 924 925 #ifdef CONFIG_MODULE_SIG 926 bool is_module_sig_enforced(void); 927 928 static inline bool module_sig_ok(struct module *module) 929 { 930 return module->sig_ok; 931 } 932 #else /* !CONFIG_MODULE_SIG */ 933 static inline bool is_module_sig_enforced(void) 934 { 935 return false; 936 } 937 938 static inline bool module_sig_ok(struct module *module) 939 { 940 return true; 941 } 942 #endif /* CONFIG_MODULE_SIG */ 943 944 #if defined(CONFIG_MODULES) && defined(CONFIG_KALLSYMS) 945 int module_kallsyms_on_each_symbol(const char *modname, 946 int (*fn)(void *, const char *, unsigned long), 947 void *data); 948 949 /* For kallsyms to ask for address resolution. namebuf should be at 950 * least KSYM_NAME_LEN long: a pointer to namebuf is returned if 951 * found, otherwise NULL. 952 */ 953 int module_address_lookup(unsigned long addr, 954 unsigned long *symbolsize, 955 unsigned long *offset, 956 char **modname, const unsigned char **modbuildid, 957 char *namebuf); 958 int lookup_module_symbol_name(unsigned long addr, char *symname); 959 int lookup_module_symbol_attrs(unsigned long addr, 960 unsigned long *size, 961 unsigned long *offset, 962 char *modname, 963 char *name); 964 965 /* Returns 0 and fills in value, defined and namebuf, or -ERANGE if 966 * symnum out of range. 967 */ 968 int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type, 969 char *name, char *module_name, int *exported); 970 971 /* Look for this name: can be of form module:name. */ 972 unsigned long module_kallsyms_lookup_name(const char *name); 973 974 unsigned long find_kallsyms_symbol_value(struct module *mod, const char *name); 975 976 #else /* CONFIG_MODULES && CONFIG_KALLSYMS */ 977 978 static inline int module_kallsyms_on_each_symbol(const char *modname, 979 int (*fn)(void *, const char *, unsigned long), 980 void *data) 981 { 982 return -EOPNOTSUPP; 983 } 984 985 /* For kallsyms to ask for address resolution. NULL means not found. */ 986 static inline int module_address_lookup(unsigned long addr, 987 unsigned long *symbolsize, 988 unsigned long *offset, 989 char **modname, 990 const unsigned char **modbuildid, 991 char *namebuf) 992 { 993 return 0; 994 } 995 996 static inline int lookup_module_symbol_name(unsigned long addr, char *symname) 997 { 998 return -ERANGE; 999 } 1000 1001 static inline int module_get_kallsym(unsigned int symnum, unsigned long *value, 1002 char *type, char *name, 1003 char *module_name, int *exported) 1004 { 1005 return -ERANGE; 1006 } 1007 1008 static inline unsigned long module_kallsyms_lookup_name(const char *name) 1009 { 1010 return 0; 1011 } 1012 1013 static inline unsigned long find_kallsyms_symbol_value(struct module *mod, 1014 const char *name) 1015 { 1016 return 0; 1017 } 1018 1019 #endif /* CONFIG_MODULES && CONFIG_KALLSYMS */ 1020 1021 #endif /* _LINUX_MODULE_H */ 1022