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) ({ \ 310 static const char __notrim[] \ 311 __used __section(".no_trim_symbol") = __stringify(x); \ 312 (typeof(&x))(__symbol_get(__stringify(x))); }) 313 314 /* modules using other modules: kdb wants to see this. */ 315 struct module_use { 316 struct list_head source_list; 317 struct list_head target_list; 318 struct module *source, *target; 319 }; 320 321 enum module_state { 322 MODULE_STATE_LIVE, /* Normal state. */ 323 MODULE_STATE_COMING, /* Full formed, running module_init. */ 324 MODULE_STATE_GOING, /* Going away. */ 325 MODULE_STATE_UNFORMED, /* Still setting it up. */ 326 }; 327 328 struct mod_tree_node { 329 struct module *mod; 330 struct latch_tree_node node; 331 }; 332 333 enum mod_mem_type { 334 MOD_TEXT = 0, 335 MOD_DATA, 336 MOD_RODATA, 337 MOD_RO_AFTER_INIT, 338 MOD_INIT_TEXT, 339 MOD_INIT_DATA, 340 MOD_INIT_RODATA, 341 342 MOD_MEM_NUM_TYPES, 343 MOD_INVALID = -1, 344 }; 345 346 #define mod_mem_type_is_init(type) \ 347 ((type) == MOD_INIT_TEXT || \ 348 (type) == MOD_INIT_DATA || \ 349 (type) == MOD_INIT_RODATA) 350 351 #define mod_mem_type_is_core(type) (!mod_mem_type_is_init(type)) 352 353 #define mod_mem_type_is_text(type) \ 354 ((type) == MOD_TEXT || \ 355 (type) == MOD_INIT_TEXT) 356 357 #define mod_mem_type_is_data(type) (!mod_mem_type_is_text(type)) 358 359 #define mod_mem_type_is_core_data(type) \ 360 (mod_mem_type_is_core(type) && \ 361 mod_mem_type_is_data(type)) 362 363 #define for_each_mod_mem_type(type) \ 364 for (enum mod_mem_type (type) = 0; \ 365 (type) < MOD_MEM_NUM_TYPES; (type)++) 366 367 #define for_class_mod_mem_type(type, class) \ 368 for_each_mod_mem_type(type) \ 369 if (mod_mem_type_is_##class(type)) 370 371 struct module_memory { 372 void *base; 373 void *rw_copy; 374 bool is_rox; 375 unsigned int size; 376 377 #ifdef CONFIG_MODULES_TREE_LOOKUP 378 struct mod_tree_node mtn; 379 #endif 380 }; 381 382 #ifdef CONFIG_MODULES_TREE_LOOKUP 383 /* Only touch one cacheline for common rbtree-for-core-layout case. */ 384 #define __module_memory_align ____cacheline_aligned 385 #else 386 #define __module_memory_align 387 #endif 388 389 struct mod_kallsyms { 390 Elf_Sym *symtab; 391 unsigned int num_symtab; 392 char *strtab; 393 char *typetab; 394 }; 395 396 #ifdef CONFIG_LIVEPATCH 397 /** 398 * struct klp_modinfo - ELF information preserved from the livepatch module 399 * 400 * @hdr: ELF header 401 * @sechdrs: Section header table 402 * @secstrings: String table for the section headers 403 * @symndx: The symbol table section index 404 */ 405 struct klp_modinfo { 406 Elf_Ehdr hdr; 407 Elf_Shdr *sechdrs; 408 char *secstrings; 409 unsigned int symndx; 410 }; 411 #endif 412 413 struct module { 414 enum module_state state; 415 416 /* Member of list of modules */ 417 struct list_head list; 418 419 /* Unique handle for this module */ 420 char name[MODULE_NAME_LEN]; 421 422 #ifdef CONFIG_STACKTRACE_BUILD_ID 423 /* Module build ID */ 424 unsigned char build_id[BUILD_ID_SIZE_MAX]; 425 #endif 426 427 /* Sysfs stuff. */ 428 struct module_kobject mkobj; 429 struct module_attribute *modinfo_attrs; 430 const char *version; 431 const char *srcversion; 432 struct kobject *holders_dir; 433 434 /* Exported symbols */ 435 const struct kernel_symbol *syms; 436 const u32 *crcs; 437 unsigned int num_syms; 438 439 #ifdef CONFIG_ARCH_USES_CFI_TRAPS 440 s32 *kcfi_traps; 441 s32 *kcfi_traps_end; 442 #endif 443 444 /* Kernel parameters. */ 445 #ifdef CONFIG_SYSFS 446 struct mutex param_lock; 447 #endif 448 struct kernel_param *kp; 449 unsigned int num_kp; 450 451 /* GPL-only exported symbols. */ 452 unsigned int num_gpl_syms; 453 const struct kernel_symbol *gpl_syms; 454 const u32 *gpl_crcs; 455 bool using_gplonly_symbols; 456 457 #ifdef CONFIG_MODULE_SIG 458 /* Signature was verified. */ 459 bool sig_ok; 460 #endif 461 462 bool async_probe_requested; 463 464 /* Exception table */ 465 unsigned int num_exentries; 466 struct exception_table_entry *extable; 467 468 /* Startup function. */ 469 int (*init)(void); 470 471 struct module_memory mem[MOD_MEM_NUM_TYPES] __module_memory_align; 472 473 /* Arch-specific module values */ 474 struct mod_arch_specific arch; 475 476 unsigned long taints; /* same bits as kernel:taint_flags */ 477 478 #ifdef CONFIG_GENERIC_BUG 479 /* Support for BUG */ 480 unsigned num_bugs; 481 struct list_head bug_list; 482 struct bug_entry *bug_table; 483 #endif 484 485 #ifdef CONFIG_KALLSYMS 486 /* Protected by RCU and/or module_mutex: use rcu_dereference() */ 487 struct mod_kallsyms __rcu *kallsyms; 488 struct mod_kallsyms core_kallsyms; 489 490 /* Section attributes */ 491 struct module_sect_attrs *sect_attrs; 492 493 /* Notes attributes */ 494 struct module_notes_attrs *notes_attrs; 495 #endif 496 497 /* The command line arguments (may be mangled). People like 498 keeping pointers to this stuff */ 499 char *args; 500 501 #ifdef CONFIG_SMP 502 /* Per-cpu data. */ 503 void __percpu *percpu; 504 unsigned int percpu_size; 505 #endif 506 void *noinstr_text_start; 507 unsigned int noinstr_text_size; 508 509 #ifdef CONFIG_TRACEPOINTS 510 unsigned int num_tracepoints; 511 tracepoint_ptr_t *tracepoints_ptrs; 512 #endif 513 #ifdef CONFIG_TREE_SRCU 514 unsigned int num_srcu_structs; 515 struct srcu_struct **srcu_struct_ptrs; 516 #endif 517 #ifdef CONFIG_BPF_EVENTS 518 unsigned int num_bpf_raw_events; 519 struct bpf_raw_event_map *bpf_raw_events; 520 #endif 521 #ifdef CONFIG_DEBUG_INFO_BTF_MODULES 522 unsigned int btf_data_size; 523 unsigned int btf_base_data_size; 524 void *btf_data; 525 void *btf_base_data; 526 #endif 527 #ifdef CONFIG_JUMP_LABEL 528 struct jump_entry *jump_entries; 529 unsigned int num_jump_entries; 530 #endif 531 #ifdef CONFIG_TRACING 532 unsigned int num_trace_bprintk_fmt; 533 const char **trace_bprintk_fmt_start; 534 #endif 535 #ifdef CONFIG_EVENT_TRACING 536 struct trace_event_call **trace_events; 537 unsigned int num_trace_events; 538 struct trace_eval_map **trace_evals; 539 unsigned int num_trace_evals; 540 #endif 541 #ifdef CONFIG_FTRACE_MCOUNT_RECORD 542 unsigned int num_ftrace_callsites; 543 unsigned long *ftrace_callsites; 544 #endif 545 #ifdef CONFIG_KPROBES 546 void *kprobes_text_start; 547 unsigned int kprobes_text_size; 548 unsigned long *kprobe_blacklist; 549 unsigned int num_kprobe_blacklist; 550 #endif 551 #ifdef CONFIG_HAVE_STATIC_CALL_INLINE 552 int num_static_call_sites; 553 struct static_call_site *static_call_sites; 554 #endif 555 #if IS_ENABLED(CONFIG_KUNIT) 556 int num_kunit_init_suites; 557 struct kunit_suite **kunit_init_suites; 558 int num_kunit_suites; 559 struct kunit_suite **kunit_suites; 560 #endif 561 562 563 #ifdef CONFIG_LIVEPATCH 564 bool klp; /* Is this a livepatch module? */ 565 bool klp_alive; 566 567 /* ELF information */ 568 struct klp_modinfo *klp_info; 569 #endif 570 571 #ifdef CONFIG_PRINTK_INDEX 572 unsigned int printk_index_size; 573 struct pi_entry **printk_index_start; 574 #endif 575 576 #ifdef CONFIG_MODULE_UNLOAD 577 /* What modules depend on me? */ 578 struct list_head source_list; 579 /* What modules do I depend on? */ 580 struct list_head target_list; 581 582 /* Destruction function. */ 583 void (*exit)(void); 584 585 atomic_t refcnt; 586 #endif 587 588 #ifdef CONFIG_CONSTRUCTORS 589 /* Constructor functions. */ 590 ctor_fn_t *ctors; 591 unsigned int num_ctors; 592 #endif 593 594 #ifdef CONFIG_FUNCTION_ERROR_INJECTION 595 struct error_injection_entry *ei_funcs; 596 unsigned int num_ei_funcs; 597 #endif 598 #ifdef CONFIG_DYNAMIC_DEBUG_CORE 599 struct _ddebug_info dyndbg_info; 600 #endif 601 } ____cacheline_aligned __randomize_layout; 602 #ifndef MODULE_ARCH_INIT 603 #define MODULE_ARCH_INIT {} 604 #endif 605 606 #ifndef HAVE_ARCH_KALLSYMS_SYMBOL_VALUE 607 static inline unsigned long kallsyms_symbol_value(const Elf_Sym *sym) 608 { 609 return sym->st_value; 610 } 611 #endif 612 613 /* FIXME: It'd be nice to isolate modules during init, too, so they 614 aren't used before they (may) fail. But presently too much code 615 (IDE & SCSI) require entry into the module during init.*/ 616 static inline bool module_is_live(struct module *mod) 617 { 618 return mod->state != MODULE_STATE_GOING; 619 } 620 621 static inline bool module_is_coming(struct module *mod) 622 { 623 return mod->state == MODULE_STATE_COMING; 624 } 625 626 struct module *__module_text_address(unsigned long addr); 627 struct module *__module_address(unsigned long addr); 628 bool is_module_address(unsigned long addr); 629 bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr); 630 bool is_module_percpu_address(unsigned long addr); 631 bool is_module_text_address(unsigned long addr); 632 633 static inline bool within_module_mem_type(unsigned long addr, 634 const struct module *mod, 635 enum mod_mem_type type) 636 { 637 unsigned long base, size; 638 639 base = (unsigned long)mod->mem[type].base; 640 size = mod->mem[type].size; 641 return addr - base < size; 642 } 643 644 static inline bool within_module_core(unsigned long addr, 645 const struct module *mod) 646 { 647 for_class_mod_mem_type(type, core) { 648 if (within_module_mem_type(addr, mod, type)) 649 return true; 650 } 651 return false; 652 } 653 654 static inline bool within_module_init(unsigned long addr, 655 const struct module *mod) 656 { 657 for_class_mod_mem_type(type, init) { 658 if (within_module_mem_type(addr, mod, type)) 659 return true; 660 } 661 return false; 662 } 663 664 static inline bool within_module(unsigned long addr, const struct module *mod) 665 { 666 return within_module_init(addr, mod) || within_module_core(addr, mod); 667 } 668 669 /* Search for module by name: must be in a RCU-sched critical section. */ 670 struct module *find_module(const char *name); 671 672 extern void __noreturn __module_put_and_kthread_exit(struct module *mod, 673 long code); 674 #define module_put_and_kthread_exit(code) __module_put_and_kthread_exit(THIS_MODULE, code) 675 676 #ifdef CONFIG_MODULE_UNLOAD 677 int module_refcount(struct module *mod); 678 void __symbol_put(const char *symbol); 679 #define symbol_put(x) __symbol_put(__stringify(x)) 680 void symbol_put_addr(void *addr); 681 682 /* Sometimes we know we already have a refcount, and it's easier not 683 to handle the error case (which only happens with rmmod --wait). */ 684 extern void __module_get(struct module *module); 685 686 /** 687 * try_module_get() - take module refcount unless module is being removed 688 * @module: the module we should check for 689 * 690 * Only try to get a module reference count if the module is not being removed. 691 * This call will fail if the module is in the process of being removed. 692 * 693 * Care must also be taken to ensure the module exists and is alive prior to 694 * usage of this call. This can be gauranteed through two means: 695 * 696 * 1) Direct protection: you know an earlier caller must have increased the 697 * module reference through __module_get(). This can typically be achieved 698 * by having another entity other than the module itself increment the 699 * module reference count. 700 * 701 * 2) Implied protection: there is an implied protection against module 702 * removal. An example of this is the implied protection used by kernfs / 703 * sysfs. The sysfs store / read file operations are guaranteed to exist 704 * through the use of kernfs's active reference (see kernfs_active()) and a 705 * sysfs / kernfs file removal cannot happen unless the same file is not 706 * active. Therefore, if a sysfs file is being read or written to the module 707 * which created it must still exist. It is therefore safe to use 708 * try_module_get() on module sysfs store / read ops. 709 * 710 * One of the real values to try_module_get() is the module_is_live() check 711 * which ensures that the caller of try_module_get() can yield to userspace 712 * module removal requests and gracefully fail if the module is on its way out. 713 * 714 * Returns true if the reference count was successfully incremented. 715 */ 716 extern bool try_module_get(struct module *module); 717 718 /** 719 * module_put() - release a reference count to a module 720 * @module: the module we should release a reference count for 721 * 722 * If you successfully bump a reference count to a module with try_module_get(), 723 * when you are finished you must call module_put() to release that reference 724 * count. 725 */ 726 extern void module_put(struct module *module); 727 728 #else /*!CONFIG_MODULE_UNLOAD*/ 729 static inline bool try_module_get(struct module *module) 730 { 731 return !module || module_is_live(module); 732 } 733 static inline void module_put(struct module *module) 734 { 735 } 736 static inline void __module_get(struct module *module) 737 { 738 } 739 #define symbol_put(x) do { } while (0) 740 #define symbol_put_addr(p) do { } while (0) 741 742 #endif /* CONFIG_MODULE_UNLOAD */ 743 744 /* This is a #define so the string doesn't get put in every .o file */ 745 #define module_name(mod) \ 746 ({ \ 747 struct module *__mod = (mod); \ 748 __mod ? __mod->name : "kernel"; \ 749 }) 750 751 /* Dereference module function descriptor */ 752 void *dereference_module_function_descriptor(struct module *mod, void *ptr); 753 754 int register_module_notifier(struct notifier_block *nb); 755 int unregister_module_notifier(struct notifier_block *nb); 756 757 extern void print_modules(void); 758 759 static inline bool module_requested_async_probing(struct module *module) 760 { 761 return module && module->async_probe_requested; 762 } 763 764 static inline bool is_livepatch_module(struct module *mod) 765 { 766 #ifdef CONFIG_LIVEPATCH 767 return mod->klp; 768 #else 769 return false; 770 #endif 771 } 772 773 void set_module_sig_enforced(void); 774 775 void *__module_writable_address(struct module *mod, void *loc); 776 777 static inline void *module_writable_address(struct module *mod, void *loc) 778 { 779 if (!IS_ENABLED(CONFIG_ARCH_HAS_EXECMEM_ROX) || !mod || 780 mod->state != MODULE_STATE_UNFORMED) 781 return loc; 782 return __module_writable_address(mod, loc); 783 } 784 785 #else /* !CONFIG_MODULES... */ 786 787 static inline struct module *__module_address(unsigned long addr) 788 { 789 return NULL; 790 } 791 792 static inline struct module *__module_text_address(unsigned long addr) 793 { 794 return NULL; 795 } 796 797 static inline bool is_module_address(unsigned long addr) 798 { 799 return false; 800 } 801 802 static inline bool is_module_percpu_address(unsigned long addr) 803 { 804 return false; 805 } 806 807 static inline bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr) 808 { 809 return false; 810 } 811 812 static inline bool is_module_text_address(unsigned long addr) 813 { 814 return false; 815 } 816 817 static inline bool within_module_core(unsigned long addr, 818 const struct module *mod) 819 { 820 return false; 821 } 822 823 static inline bool within_module_init(unsigned long addr, 824 const struct module *mod) 825 { 826 return false; 827 } 828 829 static inline bool within_module(unsigned long addr, const struct module *mod) 830 { 831 return false; 832 } 833 834 /* Get/put a kernel symbol (calls should be symmetric) */ 835 #define symbol_get(x) ({ extern typeof(x) x __attribute__((weak,visibility("hidden"))); &(x); }) 836 #define symbol_put(x) do { } while (0) 837 #define symbol_put_addr(x) do { } while (0) 838 839 static inline void __module_get(struct module *module) 840 { 841 } 842 843 static inline bool try_module_get(struct module *module) 844 { 845 return true; 846 } 847 848 static inline void module_put(struct module *module) 849 { 850 } 851 852 #define module_name(mod) "kernel" 853 854 static inline int register_module_notifier(struct notifier_block *nb) 855 { 856 /* no events will happen anyway, so this can always succeed */ 857 return 0; 858 } 859 860 static inline int unregister_module_notifier(struct notifier_block *nb) 861 { 862 return 0; 863 } 864 865 #define module_put_and_kthread_exit(code) kthread_exit(code) 866 867 static inline void print_modules(void) 868 { 869 } 870 871 static inline bool module_requested_async_probing(struct module *module) 872 { 873 return false; 874 } 875 876 877 static inline void set_module_sig_enforced(void) 878 { 879 } 880 881 /* Dereference module function descriptor */ 882 static inline 883 void *dereference_module_function_descriptor(struct module *mod, void *ptr) 884 { 885 return ptr; 886 } 887 888 static inline bool module_is_coming(struct module *mod) 889 { 890 return false; 891 } 892 893 static inline void *module_writable_address(struct module *mod, void *loc) 894 { 895 return loc; 896 } 897 #endif /* CONFIG_MODULES */ 898 899 #ifdef CONFIG_SYSFS 900 extern struct kset *module_kset; 901 extern const struct kobj_type module_ktype; 902 #endif /* CONFIG_SYSFS */ 903 904 #define symbol_request(x) try_then_request_module(symbol_get(x), "symbol:" #x) 905 906 /* BELOW HERE ALL THESE ARE OBSOLETE AND WILL VANISH */ 907 908 #define __MODULE_STRING(x) __stringify(x) 909 910 #ifdef CONFIG_GENERIC_BUG 911 void module_bug_finalize(const Elf_Ehdr *, const Elf_Shdr *, 912 struct module *); 913 void module_bug_cleanup(struct module *); 914 915 #else /* !CONFIG_GENERIC_BUG */ 916 917 static inline void module_bug_finalize(const Elf_Ehdr *hdr, 918 const Elf_Shdr *sechdrs, 919 struct module *mod) 920 { 921 } 922 static inline void module_bug_cleanup(struct module *mod) {} 923 #endif /* CONFIG_GENERIC_BUG */ 924 925 #ifdef CONFIG_MITIGATION_RETPOLINE 926 extern bool retpoline_module_ok(bool has_retpoline); 927 #else 928 static inline bool retpoline_module_ok(bool has_retpoline) 929 { 930 return true; 931 } 932 #endif 933 934 #ifdef CONFIG_MODULE_SIG 935 bool is_module_sig_enforced(void); 936 937 static inline bool module_sig_ok(struct module *module) 938 { 939 return module->sig_ok; 940 } 941 #else /* !CONFIG_MODULE_SIG */ 942 static inline bool is_module_sig_enforced(void) 943 { 944 return false; 945 } 946 947 static inline bool module_sig_ok(struct module *module) 948 { 949 return true; 950 } 951 #endif /* CONFIG_MODULE_SIG */ 952 953 #if defined(CONFIG_MODULES) && defined(CONFIG_KALLSYMS) 954 int module_kallsyms_on_each_symbol(const char *modname, 955 int (*fn)(void *, const char *, unsigned long), 956 void *data); 957 958 /* For kallsyms to ask for address resolution. namebuf should be at 959 * least KSYM_NAME_LEN long: a pointer to namebuf is returned if 960 * found, otherwise NULL. 961 */ 962 int module_address_lookup(unsigned long addr, 963 unsigned long *symbolsize, 964 unsigned long *offset, 965 char **modname, const unsigned char **modbuildid, 966 char *namebuf); 967 int lookup_module_symbol_name(unsigned long addr, char *symname); 968 int lookup_module_symbol_attrs(unsigned long addr, 969 unsigned long *size, 970 unsigned long *offset, 971 char *modname, 972 char *name); 973 974 /* Returns 0 and fills in value, defined and namebuf, or -ERANGE if 975 * symnum out of range. 976 */ 977 int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type, 978 char *name, char *module_name, int *exported); 979 980 /* Look for this name: can be of form module:name. */ 981 unsigned long module_kallsyms_lookup_name(const char *name); 982 983 unsigned long find_kallsyms_symbol_value(struct module *mod, const char *name); 984 985 #else /* CONFIG_MODULES && CONFIG_KALLSYMS */ 986 987 static inline int module_kallsyms_on_each_symbol(const char *modname, 988 int (*fn)(void *, const char *, unsigned long), 989 void *data) 990 { 991 return -EOPNOTSUPP; 992 } 993 994 /* For kallsyms to ask for address resolution. NULL means not found. */ 995 static inline int module_address_lookup(unsigned long addr, 996 unsigned long *symbolsize, 997 unsigned long *offset, 998 char **modname, 999 const unsigned char **modbuildid, 1000 char *namebuf) 1001 { 1002 return 0; 1003 } 1004 1005 static inline int lookup_module_symbol_name(unsigned long addr, char *symname) 1006 { 1007 return -ERANGE; 1008 } 1009 1010 static inline int module_get_kallsym(unsigned int symnum, unsigned long *value, 1011 char *type, char *name, 1012 char *module_name, int *exported) 1013 { 1014 return -ERANGE; 1015 } 1016 1017 static inline unsigned long module_kallsyms_lookup_name(const char *name) 1018 { 1019 return 0; 1020 } 1021 1022 static inline unsigned long find_kallsyms_symbol_value(struct module *mod, 1023 const char *name) 1024 { 1025 return 0; 1026 } 1027 1028 #endif /* CONFIG_MODULES && CONFIG_KALLSYMS */ 1029 1030 #endif /* _LINUX_MODULE_H */ 1031