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 struct module_kobject *lookup_or_create_module_kobject(const char *name); 166 167 /* Generic info of form tag = "info" */ 168 #define MODULE_INFO(tag, info) __MODULE_INFO(tag, tag, info) 169 170 /* For userspace: you can also call me... */ 171 #define MODULE_ALIAS(_alias) MODULE_INFO(alias, _alias) 172 173 /* Soft module dependencies. See man modprobe.d for details. 174 * Example: MODULE_SOFTDEP("pre: module-foo module-bar post: module-baz") 175 */ 176 #define MODULE_SOFTDEP(_softdep) MODULE_INFO(softdep, _softdep) 177 178 /* 179 * Weak module dependencies. See man modprobe.d for details. 180 * Example: MODULE_WEAKDEP("module-foo") 181 */ 182 #define MODULE_WEAKDEP(_weakdep) MODULE_INFO(weakdep, _weakdep) 183 184 /* 185 * MODULE_FILE is used for generating modules.builtin 186 * So, make it no-op when this is being built as a module 187 */ 188 #ifdef MODULE 189 #define MODULE_FILE 190 #else 191 #define MODULE_FILE MODULE_INFO(file, KBUILD_MODFILE); 192 #endif 193 194 /* 195 * The following license idents are currently accepted as indicating free 196 * software modules 197 * 198 * "GPL" [GNU Public License v2] 199 * "GPL v2" [GNU Public License v2] 200 * "GPL and additional rights" [GNU Public License v2 rights and more] 201 * "Dual BSD/GPL" [GNU Public License v2 202 * or BSD license choice] 203 * "Dual MIT/GPL" [GNU Public License v2 204 * or MIT license choice] 205 * "Dual MPL/GPL" [GNU Public License v2 206 * or Mozilla license choice] 207 * 208 * The following other idents are available 209 * 210 * "Proprietary" [Non free products] 211 * 212 * Both "GPL v2" and "GPL" (the latter also in dual licensed strings) are 213 * merely stating that the module is licensed under the GPL v2, but are not 214 * telling whether "GPL v2 only" or "GPL v2 or later". The reason why there 215 * are two variants is a historic and failed attempt to convey more 216 * information in the MODULE_LICENSE string. For module loading the 217 * "only/or later" distinction is completely irrelevant and does neither 218 * replace the proper license identifiers in the corresponding source file 219 * nor amends them in any way. The sole purpose is to make the 220 * 'Proprietary' flagging work and to refuse to bind symbols which are 221 * exported with EXPORT_SYMBOL_GPL when a non free module is loaded. 222 * 223 * In the same way "BSD" is not a clear license information. It merely 224 * states, that the module is licensed under one of the compatible BSD 225 * license variants. The detailed and correct license information is again 226 * to be found in the corresponding source files. 227 * 228 * There are dual licensed components, but when running with Linux it is the 229 * GPL that is relevant so this is a non issue. Similarly LGPL linked with GPL 230 * is a GPL combined work. 231 * 232 * This exists for several reasons 233 * 1. So modinfo can show license info for users wanting to vet their setup 234 * is free 235 * 2. So the community can ignore bug reports including proprietary modules 236 * 3. So vendors can do likewise based on their own policies 237 */ 238 #define MODULE_LICENSE(_license) MODULE_FILE MODULE_INFO(license, _license) 239 240 /* 241 * Author(s), use "Name <email>" or just "Name", for multiple 242 * authors use multiple MODULE_AUTHOR() statements/lines. 243 */ 244 #define MODULE_AUTHOR(_author) MODULE_INFO(author, _author) 245 246 /* What your module does. */ 247 #define MODULE_DESCRIPTION(_description) MODULE_INFO(description, _description) 248 249 #ifdef MODULE 250 /* Creates an alias so file2alias.c can find device table. */ 251 #define MODULE_DEVICE_TABLE(type, name) \ 252 extern typeof(name) __mod_device_table__##type##__##name \ 253 __attribute__ ((unused, alias(__stringify(name)))) 254 #else /* !MODULE */ 255 #define MODULE_DEVICE_TABLE(type, name) 256 #endif 257 258 /* Version of form [<epoch>:]<version>[-<extra-version>]. 259 * Or for CVS/RCS ID version, everything but the number is stripped. 260 * <epoch>: A (small) unsigned integer which allows you to start versions 261 * anew. If not mentioned, it's zero. eg. "2:1.0" is after 262 * "1:2.0". 263 264 * <version>: The <version> may contain only alphanumerics and the 265 * character `.'. Ordered by numeric sort for numeric parts, 266 * ascii sort for ascii parts (as per RPM or DEB algorithm). 267 268 * <extraversion>: Like <version>, but inserted for local 269 * customizations, eg "rh3" or "rusty1". 270 271 * Using this automatically adds a checksum of the .c files and the 272 * local headers in "srcversion". 273 */ 274 275 #if defined(MODULE) || !defined(CONFIG_SYSFS) 276 #define MODULE_VERSION(_version) MODULE_INFO(version, _version) 277 #else 278 #define MODULE_VERSION(_version) \ 279 MODULE_INFO(version, _version); \ 280 static const struct module_version_attribute __modver_attr \ 281 __used __section("__modver") \ 282 __aligned(__alignof__(struct module_version_attribute)) \ 283 = { \ 284 .mattr = { \ 285 .attr = { \ 286 .name = "version", \ 287 .mode = S_IRUGO, \ 288 }, \ 289 .show = __modver_version_show, \ 290 }, \ 291 .module_name = KBUILD_MODNAME, \ 292 .version = _version, \ 293 } 294 #endif 295 296 /* Optional firmware file (or files) needed by the module 297 * format is simply firmware file name. Multiple firmware 298 * files require multiple MODULE_FIRMWARE() specifiers */ 299 #define MODULE_FIRMWARE(_firmware) MODULE_INFO(firmware, _firmware) 300 301 #define MODULE_IMPORT_NS(ns) MODULE_INFO(import_ns, ns) 302 303 struct notifier_block; 304 305 #ifdef CONFIG_MODULES 306 307 extern int modules_disabled; /* for sysctl */ 308 /* Get/put a kernel symbol (calls must be symmetric) */ 309 void *__symbol_get(const char *symbol); 310 void *__symbol_get_gpl(const char *symbol); 311 #define symbol_get(x) ({ \ 312 static const char __notrim[] \ 313 __used __section(".no_trim_symbol") = __stringify(x); \ 314 (typeof(&x))(__symbol_get(__stringify(x))); }) 315 316 /* modules using other modules: kdb wants to see this. */ 317 struct module_use { 318 struct list_head source_list; 319 struct list_head target_list; 320 struct module *source, *target; 321 }; 322 323 enum module_state { 324 MODULE_STATE_LIVE, /* Normal state. */ 325 MODULE_STATE_COMING, /* Full formed, running module_init. */ 326 MODULE_STATE_GOING, /* Going away. */ 327 MODULE_STATE_UNFORMED, /* Still setting it up. */ 328 }; 329 330 struct mod_tree_node { 331 struct module *mod; 332 struct latch_tree_node node; 333 }; 334 335 enum mod_mem_type { 336 MOD_TEXT = 0, 337 MOD_DATA, 338 MOD_RODATA, 339 MOD_RO_AFTER_INIT, 340 MOD_INIT_TEXT, 341 MOD_INIT_DATA, 342 MOD_INIT_RODATA, 343 344 MOD_MEM_NUM_TYPES, 345 MOD_INVALID = -1, 346 }; 347 348 #define mod_mem_type_is_init(type) \ 349 ((type) == MOD_INIT_TEXT || \ 350 (type) == MOD_INIT_DATA || \ 351 (type) == MOD_INIT_RODATA) 352 353 #define mod_mem_type_is_core(type) (!mod_mem_type_is_init(type)) 354 355 #define mod_mem_type_is_text(type) \ 356 ((type) == MOD_TEXT || \ 357 (type) == MOD_INIT_TEXT) 358 359 #define mod_mem_type_is_data(type) (!mod_mem_type_is_text(type)) 360 361 #define mod_mem_type_is_core_data(type) \ 362 (mod_mem_type_is_core(type) && \ 363 mod_mem_type_is_data(type)) 364 365 #define for_each_mod_mem_type(type) \ 366 for (enum mod_mem_type (type) = 0; \ 367 (type) < MOD_MEM_NUM_TYPES; (type)++) 368 369 #define for_class_mod_mem_type(type, class) \ 370 for_each_mod_mem_type(type) \ 371 if (mod_mem_type_is_##class(type)) 372 373 struct module_memory { 374 void *base; 375 bool is_rox; 376 unsigned int size; 377 378 #ifdef CONFIG_MODULES_TREE_LOOKUP 379 struct mod_tree_node mtn; 380 #endif 381 }; 382 383 #ifdef CONFIG_MODULES_TREE_LOOKUP 384 /* Only touch one cacheline for common rbtree-for-core-layout case. */ 385 #define __module_memory_align ____cacheline_aligned 386 #else 387 #define __module_memory_align 388 #endif 389 390 struct mod_kallsyms { 391 Elf_Sym *symtab; 392 unsigned int num_symtab; 393 char *strtab; 394 char *typetab; 395 }; 396 397 #ifdef CONFIG_LIVEPATCH 398 /** 399 * struct klp_modinfo - ELF information preserved from the livepatch module 400 * 401 * @hdr: ELF header 402 * @sechdrs: Section header table 403 * @secstrings: String table for the section headers 404 * @symndx: The symbol table section index 405 */ 406 struct klp_modinfo { 407 Elf_Ehdr hdr; 408 Elf_Shdr *sechdrs; 409 char *secstrings; 410 unsigned int symndx; 411 }; 412 #endif 413 414 struct module { 415 enum module_state state; 416 417 /* Member of list of modules */ 418 struct list_head list; 419 420 /* Unique handle for this module */ 421 char name[MODULE_NAME_LEN]; 422 423 #ifdef CONFIG_STACKTRACE_BUILD_ID 424 /* Module build ID */ 425 unsigned char build_id[BUILD_ID_SIZE_MAX]; 426 #endif 427 428 /* Sysfs stuff. */ 429 struct module_kobject mkobj; 430 struct module_attribute *modinfo_attrs; 431 const char *version; 432 const char *srcversion; 433 struct kobject *holders_dir; 434 435 /* Exported symbols */ 436 const struct kernel_symbol *syms; 437 const u32 *crcs; 438 unsigned int num_syms; 439 440 #ifdef CONFIG_ARCH_USES_CFI_TRAPS 441 s32 *kcfi_traps; 442 s32 *kcfi_traps_end; 443 #endif 444 445 /* Kernel parameters. */ 446 #ifdef CONFIG_SYSFS 447 struct mutex param_lock; 448 #endif 449 struct kernel_param *kp; 450 unsigned int num_kp; 451 452 /* GPL-only exported symbols. */ 453 unsigned int num_gpl_syms; 454 const struct kernel_symbol *gpl_syms; 455 const u32 *gpl_crcs; 456 bool using_gplonly_symbols; 457 458 #ifdef CONFIG_MODULE_SIG 459 /* Signature was verified. */ 460 bool sig_ok; 461 #endif 462 463 bool async_probe_requested; 464 465 /* Exception table */ 466 unsigned int num_exentries; 467 struct exception_table_entry *extable; 468 469 /* Startup function. */ 470 int (*init)(void); 471 472 struct module_memory mem[MOD_MEM_NUM_TYPES] __module_memory_align; 473 474 /* Arch-specific module values */ 475 struct mod_arch_specific arch; 476 477 unsigned long taints; /* same bits as kernel:taint_flags */ 478 479 #ifdef CONFIG_GENERIC_BUG 480 /* Support for BUG */ 481 unsigned num_bugs; 482 struct list_head bug_list; 483 struct bug_entry *bug_table; 484 #endif 485 486 #ifdef CONFIG_KALLSYMS 487 /* Protected by RCU and/or module_mutex: use rcu_dereference() */ 488 struct mod_kallsyms __rcu *kallsyms; 489 struct mod_kallsyms core_kallsyms; 490 491 /* Section attributes */ 492 struct module_sect_attrs *sect_attrs; 493 494 /* Notes attributes */ 495 struct module_notes_attrs *notes_attrs; 496 #endif 497 498 /* The command line arguments (may be mangled). People like 499 keeping pointers to this stuff */ 500 char *args; 501 502 #ifdef CONFIG_SMP 503 /* Per-cpu data. */ 504 void __percpu *percpu; 505 unsigned int percpu_size; 506 #endif 507 void *noinstr_text_start; 508 unsigned int noinstr_text_size; 509 510 #ifdef CONFIG_TRACEPOINTS 511 unsigned int num_tracepoints; 512 tracepoint_ptr_t *tracepoints_ptrs; 513 #endif 514 #ifdef CONFIG_TREE_SRCU 515 unsigned int num_srcu_structs; 516 struct srcu_struct **srcu_struct_ptrs; 517 #endif 518 #ifdef CONFIG_BPF_EVENTS 519 unsigned int num_bpf_raw_events; 520 struct bpf_raw_event_map *bpf_raw_events; 521 #endif 522 #ifdef CONFIG_DEBUG_INFO_BTF_MODULES 523 unsigned int btf_data_size; 524 unsigned int btf_base_data_size; 525 void *btf_data; 526 void *btf_base_data; 527 #endif 528 #ifdef CONFIG_JUMP_LABEL 529 struct jump_entry *jump_entries; 530 unsigned int num_jump_entries; 531 #endif 532 #ifdef CONFIG_TRACING 533 unsigned int num_trace_bprintk_fmt; 534 const char **trace_bprintk_fmt_start; 535 #endif 536 #ifdef CONFIG_EVENT_TRACING 537 struct trace_event_call **trace_events; 538 unsigned int num_trace_events; 539 struct trace_eval_map **trace_evals; 540 unsigned int num_trace_evals; 541 #endif 542 #ifdef CONFIG_FTRACE_MCOUNT_RECORD 543 unsigned int num_ftrace_callsites; 544 unsigned long *ftrace_callsites; 545 #endif 546 #ifdef CONFIG_KPROBES 547 void *kprobes_text_start; 548 unsigned int kprobes_text_size; 549 unsigned long *kprobe_blacklist; 550 unsigned int num_kprobe_blacklist; 551 #endif 552 #ifdef CONFIG_HAVE_STATIC_CALL_INLINE 553 int num_static_call_sites; 554 struct static_call_site *static_call_sites; 555 #endif 556 #if IS_ENABLED(CONFIG_KUNIT) 557 int num_kunit_init_suites; 558 struct kunit_suite **kunit_init_suites; 559 int num_kunit_suites; 560 struct kunit_suite **kunit_suites; 561 #endif 562 563 564 #ifdef CONFIG_LIVEPATCH 565 bool klp; /* Is this a livepatch module? */ 566 bool klp_alive; 567 568 /* ELF information */ 569 struct klp_modinfo *klp_info; 570 #endif 571 572 #ifdef CONFIG_PRINTK_INDEX 573 unsigned int printk_index_size; 574 struct pi_entry **printk_index_start; 575 #endif 576 577 #ifdef CONFIG_MODULE_UNLOAD 578 /* What modules depend on me? */ 579 struct list_head source_list; 580 /* What modules do I depend on? */ 581 struct list_head target_list; 582 583 /* Destruction function. */ 584 void (*exit)(void); 585 586 atomic_t refcnt; 587 #endif 588 589 #ifdef CONFIG_CONSTRUCTORS 590 /* Constructor functions. */ 591 ctor_fn_t *ctors; 592 unsigned int num_ctors; 593 #endif 594 595 #ifdef CONFIG_FUNCTION_ERROR_INJECTION 596 struct error_injection_entry *ei_funcs; 597 unsigned int num_ei_funcs; 598 #endif 599 #ifdef CONFIG_DYNAMIC_DEBUG_CORE 600 struct _ddebug_info dyndbg_info; 601 #endif 602 } ____cacheline_aligned __randomize_layout; 603 #ifndef MODULE_ARCH_INIT 604 #define MODULE_ARCH_INIT {} 605 #endif 606 607 #ifndef HAVE_ARCH_KALLSYMS_SYMBOL_VALUE 608 static inline unsigned long kallsyms_symbol_value(const Elf_Sym *sym) 609 { 610 return sym->st_value; 611 } 612 #endif 613 614 /* FIXME: It'd be nice to isolate modules during init, too, so they 615 aren't used before they (may) fail. But presently too much code 616 (IDE & SCSI) require entry into the module during init.*/ 617 static inline bool module_is_live(struct module *mod) 618 { 619 return mod->state != MODULE_STATE_GOING; 620 } 621 622 static inline bool module_is_coming(struct module *mod) 623 { 624 return mod->state == MODULE_STATE_COMING; 625 } 626 627 struct module *__module_text_address(unsigned long addr); 628 struct module *__module_address(unsigned long addr); 629 bool is_module_address(unsigned long addr); 630 bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr); 631 bool is_module_percpu_address(unsigned long addr); 632 bool is_module_text_address(unsigned long addr); 633 634 static inline bool within_module_mem_type(unsigned long addr, 635 const struct module *mod, 636 enum mod_mem_type type) 637 { 638 unsigned long base, size; 639 640 base = (unsigned long)mod->mem[type].base; 641 size = mod->mem[type].size; 642 return addr - base < size; 643 } 644 645 static inline bool within_module_core(unsigned long addr, 646 const struct module *mod) 647 { 648 for_class_mod_mem_type(type, core) { 649 if (within_module_mem_type(addr, mod, type)) 650 return true; 651 } 652 return false; 653 } 654 655 static inline bool within_module_init(unsigned long addr, 656 const struct module *mod) 657 { 658 for_class_mod_mem_type(type, init) { 659 if (within_module_mem_type(addr, mod, type)) 660 return true; 661 } 662 return false; 663 } 664 665 static inline bool within_module(unsigned long addr, const struct module *mod) 666 { 667 return within_module_init(addr, mod) || within_module_core(addr, mod); 668 } 669 670 /* Search for module by name: must be in a RCU critical section. */ 671 struct module *find_module(const char *name); 672 673 extern void __noreturn __module_put_and_kthread_exit(struct module *mod, 674 long code); 675 #define module_put_and_kthread_exit(code) __module_put_and_kthread_exit(THIS_MODULE, code) 676 677 #ifdef CONFIG_MODULE_UNLOAD 678 int module_refcount(struct module *mod); 679 void __symbol_put(const char *symbol); 680 #define symbol_put(x) __symbol_put(__stringify(x)) 681 void symbol_put_addr(void *addr); 682 683 /* Sometimes we know we already have a refcount, and it's easier not 684 to handle the error case (which only happens with rmmod --wait). */ 685 extern void __module_get(struct module *module); 686 687 /** 688 * try_module_get() - take module refcount unless module is being removed 689 * @module: the module we should check for 690 * 691 * Only try to get a module reference count if the module is not being removed. 692 * This call will fail if the module is in the process of being removed. 693 * 694 * Care must also be taken to ensure the module exists and is alive prior to 695 * usage of this call. This can be gauranteed through two means: 696 * 697 * 1) Direct protection: you know an earlier caller must have increased the 698 * module reference through __module_get(). This can typically be achieved 699 * by having another entity other than the module itself increment the 700 * module reference count. 701 * 702 * 2) Implied protection: there is an implied protection against module 703 * removal. An example of this is the implied protection used by kernfs / 704 * sysfs. The sysfs store / read file operations are guaranteed to exist 705 * through the use of kernfs's active reference (see kernfs_active()) and a 706 * sysfs / kernfs file removal cannot happen unless the same file is not 707 * active. Therefore, if a sysfs file is being read or written to the module 708 * which created it must still exist. It is therefore safe to use 709 * try_module_get() on module sysfs store / read ops. 710 * 711 * One of the real values to try_module_get() is the module_is_live() check 712 * which ensures that the caller of try_module_get() can yield to userspace 713 * module removal requests and gracefully fail if the module is on its way out. 714 * 715 * Returns true if the reference count was successfully incremented. 716 */ 717 extern bool try_module_get(struct module *module); 718 719 /** 720 * module_put() - release a reference count to a module 721 * @module: the module we should release a reference count for 722 * 723 * If you successfully bump a reference count to a module with try_module_get(), 724 * when you are finished you must call module_put() to release that reference 725 * count. 726 */ 727 extern void module_put(struct module *module); 728 729 #else /*!CONFIG_MODULE_UNLOAD*/ 730 static inline bool try_module_get(struct module *module) 731 { 732 return !module || module_is_live(module); 733 } 734 static inline void module_put(struct module *module) 735 { 736 } 737 static inline void __module_get(struct module *module) 738 { 739 } 740 #define symbol_put(x) do { } while (0) 741 #define symbol_put_addr(p) do { } while (0) 742 743 #endif /* CONFIG_MODULE_UNLOAD */ 744 745 /* This is a #define so the string doesn't get put in every .o file */ 746 #define module_name(mod) \ 747 ({ \ 748 struct module *__mod = (mod); \ 749 __mod ? __mod->name : "kernel"; \ 750 }) 751 752 /* Dereference module function descriptor */ 753 void *dereference_module_function_descriptor(struct module *mod, void *ptr); 754 755 int register_module_notifier(struct notifier_block *nb); 756 int unregister_module_notifier(struct notifier_block *nb); 757 758 extern void print_modules(void); 759 760 static inline bool module_requested_async_probing(struct module *module) 761 { 762 return module && module->async_probe_requested; 763 } 764 765 static inline bool is_livepatch_module(struct module *mod) 766 { 767 #ifdef CONFIG_LIVEPATCH 768 return mod->klp; 769 #else 770 return false; 771 #endif 772 } 773 774 void set_module_sig_enforced(void); 775 776 void module_for_each_mod(int(*func)(struct module *mod, void *data), void *data); 777 778 #else /* !CONFIG_MODULES... */ 779 780 static inline struct module *__module_address(unsigned long addr) 781 { 782 return NULL; 783 } 784 785 static inline struct module *__module_text_address(unsigned long addr) 786 { 787 return NULL; 788 } 789 790 static inline bool is_module_address(unsigned long addr) 791 { 792 return false; 793 } 794 795 static inline bool is_module_percpu_address(unsigned long addr) 796 { 797 return false; 798 } 799 800 static inline bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr) 801 { 802 return false; 803 } 804 805 static inline bool is_module_text_address(unsigned long addr) 806 { 807 return false; 808 } 809 810 static inline bool within_module_core(unsigned long addr, 811 const struct module *mod) 812 { 813 return false; 814 } 815 816 static inline bool within_module_init(unsigned long addr, 817 const struct module *mod) 818 { 819 return false; 820 } 821 822 static inline bool within_module(unsigned long addr, const struct module *mod) 823 { 824 return false; 825 } 826 827 /* Get/put a kernel symbol (calls should be symmetric) */ 828 #define symbol_get(x) ({ extern typeof(x) x __attribute__((weak,visibility("hidden"))); &(x); }) 829 #define symbol_put(x) do { } while (0) 830 #define symbol_put_addr(x) do { } while (0) 831 832 static inline void __module_get(struct module *module) 833 { 834 } 835 836 static inline bool try_module_get(struct module *module) 837 { 838 return true; 839 } 840 841 static inline void module_put(struct module *module) 842 { 843 } 844 845 #define module_name(mod) "kernel" 846 847 static inline int register_module_notifier(struct notifier_block *nb) 848 { 849 /* no events will happen anyway, so this can always succeed */ 850 return 0; 851 } 852 853 static inline int unregister_module_notifier(struct notifier_block *nb) 854 { 855 return 0; 856 } 857 858 #define module_put_and_kthread_exit(code) kthread_exit(code) 859 860 static inline void print_modules(void) 861 { 862 } 863 864 static inline bool module_requested_async_probing(struct module *module) 865 { 866 return false; 867 } 868 869 870 static inline void set_module_sig_enforced(void) 871 { 872 } 873 874 /* Dereference module function descriptor */ 875 static inline 876 void *dereference_module_function_descriptor(struct module *mod, void *ptr) 877 { 878 return ptr; 879 } 880 881 static inline bool module_is_coming(struct module *mod) 882 { 883 return false; 884 } 885 886 static inline void module_for_each_mod(int(*func)(struct module *mod, void *data), void *data) 887 { 888 } 889 #endif /* CONFIG_MODULES */ 890 891 #ifdef CONFIG_SYSFS 892 extern struct kset *module_kset; 893 extern const struct kobj_type module_ktype; 894 #endif /* CONFIG_SYSFS */ 895 896 #define symbol_request(x) try_then_request_module(symbol_get(x), "symbol:" #x) 897 898 /* BELOW HERE ALL THESE ARE OBSOLETE AND WILL VANISH */ 899 900 #define __MODULE_STRING(x) __stringify(x) 901 902 #ifdef CONFIG_GENERIC_BUG 903 void module_bug_finalize(const Elf_Ehdr *, const Elf_Shdr *, 904 struct module *); 905 void module_bug_cleanup(struct module *); 906 907 #else /* !CONFIG_GENERIC_BUG */ 908 909 static inline void module_bug_finalize(const Elf_Ehdr *hdr, 910 const Elf_Shdr *sechdrs, 911 struct module *mod) 912 { 913 } 914 static inline void module_bug_cleanup(struct module *mod) {} 915 #endif /* CONFIG_GENERIC_BUG */ 916 917 #ifdef CONFIG_MITIGATION_RETPOLINE 918 extern bool retpoline_module_ok(bool has_retpoline); 919 #else 920 static inline bool retpoline_module_ok(bool has_retpoline) 921 { 922 return true; 923 } 924 #endif 925 926 #ifdef CONFIG_MODULE_SIG 927 bool is_module_sig_enforced(void); 928 929 static inline bool module_sig_ok(struct module *module) 930 { 931 return module->sig_ok; 932 } 933 #else /* !CONFIG_MODULE_SIG */ 934 static inline bool is_module_sig_enforced(void) 935 { 936 return false; 937 } 938 939 static inline bool module_sig_ok(struct module *module) 940 { 941 return true; 942 } 943 #endif /* CONFIG_MODULE_SIG */ 944 945 #if defined(CONFIG_MODULES) && defined(CONFIG_KALLSYMS) 946 int module_kallsyms_on_each_symbol(const char *modname, 947 int (*fn)(void *, const char *, unsigned long), 948 void *data); 949 950 /* For kallsyms to ask for address resolution. namebuf should be at 951 * least KSYM_NAME_LEN long: a pointer to namebuf is returned if 952 * found, otherwise NULL. 953 */ 954 int module_address_lookup(unsigned long addr, 955 unsigned long *symbolsize, 956 unsigned long *offset, 957 char **modname, const unsigned char **modbuildid, 958 char *namebuf); 959 int lookup_module_symbol_name(unsigned long addr, char *symname); 960 int lookup_module_symbol_attrs(unsigned long addr, 961 unsigned long *size, 962 unsigned long *offset, 963 char *modname, 964 char *name); 965 966 /* Returns 0 and fills in value, defined and namebuf, or -ERANGE if 967 * symnum out of range. 968 */ 969 int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type, 970 char *name, char *module_name, int *exported); 971 972 /* Look for this name: can be of form module:name. */ 973 unsigned long module_kallsyms_lookup_name(const char *name); 974 975 unsigned long find_kallsyms_symbol_value(struct module *mod, const char *name); 976 977 #else /* CONFIG_MODULES && CONFIG_KALLSYMS */ 978 979 static inline int module_kallsyms_on_each_symbol(const char *modname, 980 int (*fn)(void *, const char *, unsigned long), 981 void *data) 982 { 983 return -EOPNOTSUPP; 984 } 985 986 /* For kallsyms to ask for address resolution. NULL means not found. */ 987 static inline int module_address_lookup(unsigned long addr, 988 unsigned long *symbolsize, 989 unsigned long *offset, 990 char **modname, 991 const unsigned char **modbuildid, 992 char *namebuf) 993 { 994 return 0; 995 } 996 997 static inline int lookup_module_symbol_name(unsigned long addr, char *symname) 998 { 999 return -ERANGE; 1000 } 1001 1002 static inline int module_get_kallsym(unsigned int symnum, unsigned long *value, 1003 char *type, char *name, 1004 char *module_name, int *exported) 1005 { 1006 return -ERANGE; 1007 } 1008 1009 static inline unsigned long module_kallsyms_lookup_name(const char *name) 1010 { 1011 return 0; 1012 } 1013 1014 static inline unsigned long find_kallsyms_symbol_value(struct module *mod, 1015 const char *name) 1016 { 1017 return 0; 1018 } 1019 1020 #endif /* CONFIG_MODULES && CONFIG_KALLSYMS */ 1021 1022 #endif /* _LINUX_MODULE_H */ 1023