1 /* SPDX-License-Identifier: GPL-2.0-only */ 2 /* 3 * Dynamic loading of modules into the kernel. 4 * 5 * Rewritten by Richard Henderson <rth@tamu.edu> 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)(struct module_attribute *, struct module_kobject *, 56 char *); 57 ssize_t (*store)(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(struct module_attribute *, 71 struct module_kobject *, char *); 72 73 extern 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_##type##__##name##_device_table \ 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 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, __stringify(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 unsigned int size; 371 372 #ifdef CONFIG_MODULES_TREE_LOOKUP 373 struct mod_tree_node mtn; 374 #endif 375 }; 376 377 #ifdef CONFIG_MODULES_TREE_LOOKUP 378 /* Only touch one cacheline for common rbtree-for-core-layout case. */ 379 #define __module_memory_align ____cacheline_aligned 380 #else 381 #define __module_memory_align 382 #endif 383 384 struct mod_kallsyms { 385 Elf_Sym *symtab; 386 unsigned int num_symtab; 387 char *strtab; 388 char *typetab; 389 }; 390 391 #ifdef CONFIG_LIVEPATCH 392 /** 393 * struct klp_modinfo - ELF information preserved from the livepatch module 394 * 395 * @hdr: ELF header 396 * @sechdrs: Section header table 397 * @secstrings: String table for the section headers 398 * @symndx: The symbol table section index 399 */ 400 struct klp_modinfo { 401 Elf_Ehdr hdr; 402 Elf_Shdr *sechdrs; 403 char *secstrings; 404 unsigned int symndx; 405 }; 406 #endif 407 408 struct module { 409 enum module_state state; 410 411 /* Member of list of modules */ 412 struct list_head list; 413 414 /* Unique handle for this module */ 415 char name[MODULE_NAME_LEN]; 416 417 #ifdef CONFIG_STACKTRACE_BUILD_ID 418 /* Module build ID */ 419 unsigned char build_id[BUILD_ID_SIZE_MAX]; 420 #endif 421 422 /* Sysfs stuff. */ 423 struct module_kobject mkobj; 424 struct module_attribute *modinfo_attrs; 425 const char *version; 426 const char *srcversion; 427 struct kobject *holders_dir; 428 429 /* Exported symbols */ 430 const struct kernel_symbol *syms; 431 const s32 *crcs; 432 unsigned int num_syms; 433 434 #ifdef CONFIG_ARCH_USES_CFI_TRAPS 435 s32 *kcfi_traps; 436 s32 *kcfi_traps_end; 437 #endif 438 439 /* Kernel parameters. */ 440 #ifdef CONFIG_SYSFS 441 struct mutex param_lock; 442 #endif 443 struct kernel_param *kp; 444 unsigned int num_kp; 445 446 /* GPL-only exported symbols. */ 447 unsigned int num_gpl_syms; 448 const struct kernel_symbol *gpl_syms; 449 const s32 *gpl_crcs; 450 bool using_gplonly_symbols; 451 452 #ifdef CONFIG_MODULE_SIG 453 /* Signature was verified. */ 454 bool sig_ok; 455 #endif 456 457 bool async_probe_requested; 458 459 /* Exception table */ 460 unsigned int num_exentries; 461 struct exception_table_entry *extable; 462 463 /* Startup function. */ 464 int (*init)(void); 465 466 struct module_memory mem[MOD_MEM_NUM_TYPES] __module_memory_align; 467 468 /* Arch-specific module values */ 469 struct mod_arch_specific arch; 470 471 unsigned long taints; /* same bits as kernel:taint_flags */ 472 473 #ifdef CONFIG_GENERIC_BUG 474 /* Support for BUG */ 475 unsigned num_bugs; 476 struct list_head bug_list; 477 struct bug_entry *bug_table; 478 #endif 479 480 #ifdef CONFIG_KALLSYMS 481 /* Protected by RCU and/or module_mutex: use rcu_dereference() */ 482 struct mod_kallsyms __rcu *kallsyms; 483 struct mod_kallsyms core_kallsyms; 484 485 /* Section attributes */ 486 struct module_sect_attrs *sect_attrs; 487 488 /* Notes attributes */ 489 struct module_notes_attrs *notes_attrs; 490 #endif 491 492 /* The command line arguments (may be mangled). People like 493 keeping pointers to this stuff */ 494 char *args; 495 496 #ifdef CONFIG_SMP 497 /* Per-cpu data. */ 498 void __percpu *percpu; 499 unsigned int percpu_size; 500 #endif 501 void *noinstr_text_start; 502 unsigned int noinstr_text_size; 503 504 #ifdef CONFIG_TRACEPOINTS 505 unsigned int num_tracepoints; 506 tracepoint_ptr_t *tracepoints_ptrs; 507 #endif 508 #ifdef CONFIG_TREE_SRCU 509 unsigned int num_srcu_structs; 510 struct srcu_struct **srcu_struct_ptrs; 511 #endif 512 #ifdef CONFIG_BPF_EVENTS 513 unsigned int num_bpf_raw_events; 514 struct bpf_raw_event_map *bpf_raw_events; 515 #endif 516 #ifdef CONFIG_DEBUG_INFO_BTF_MODULES 517 unsigned int btf_data_size; 518 unsigned int btf_base_data_size; 519 void *btf_data; 520 void *btf_base_data; 521 #endif 522 #ifdef CONFIG_JUMP_LABEL 523 struct jump_entry *jump_entries; 524 unsigned int num_jump_entries; 525 #endif 526 #ifdef CONFIG_TRACING 527 unsigned int num_trace_bprintk_fmt; 528 const char **trace_bprintk_fmt_start; 529 #endif 530 #ifdef CONFIG_EVENT_TRACING 531 struct trace_event_call **trace_events; 532 unsigned int num_trace_events; 533 struct trace_eval_map **trace_evals; 534 unsigned int num_trace_evals; 535 #endif 536 #ifdef CONFIG_FTRACE_MCOUNT_RECORD 537 unsigned int num_ftrace_callsites; 538 unsigned long *ftrace_callsites; 539 #endif 540 #ifdef CONFIG_KPROBES 541 void *kprobes_text_start; 542 unsigned int kprobes_text_size; 543 unsigned long *kprobe_blacklist; 544 unsigned int num_kprobe_blacklist; 545 #endif 546 #ifdef CONFIG_HAVE_STATIC_CALL_INLINE 547 int num_static_call_sites; 548 struct static_call_site *static_call_sites; 549 #endif 550 #if IS_ENABLED(CONFIG_KUNIT) 551 int num_kunit_init_suites; 552 struct kunit_suite **kunit_init_suites; 553 int num_kunit_suites; 554 struct kunit_suite **kunit_suites; 555 #endif 556 557 558 #ifdef CONFIG_LIVEPATCH 559 bool klp; /* Is this a livepatch module? */ 560 bool klp_alive; 561 562 /* ELF information */ 563 struct klp_modinfo *klp_info; 564 #endif 565 566 #ifdef CONFIG_PRINTK_INDEX 567 unsigned int printk_index_size; 568 struct pi_entry **printk_index_start; 569 #endif 570 571 #ifdef CONFIG_MODULE_UNLOAD 572 /* What modules depend on me? */ 573 struct list_head source_list; 574 /* What modules do I depend on? */ 575 struct list_head target_list; 576 577 /* Destruction function. */ 578 void (*exit)(void); 579 580 atomic_t refcnt; 581 #endif 582 583 #ifdef CONFIG_CONSTRUCTORS 584 /* Constructor functions. */ 585 ctor_fn_t *ctors; 586 unsigned int num_ctors; 587 #endif 588 589 #ifdef CONFIG_FUNCTION_ERROR_INJECTION 590 struct error_injection_entry *ei_funcs; 591 unsigned int num_ei_funcs; 592 #endif 593 #ifdef CONFIG_DYNAMIC_DEBUG_CORE 594 struct _ddebug_info dyndbg_info; 595 #endif 596 } ____cacheline_aligned __randomize_layout; 597 #ifndef MODULE_ARCH_INIT 598 #define MODULE_ARCH_INIT {} 599 #endif 600 601 #ifndef HAVE_ARCH_KALLSYMS_SYMBOL_VALUE kallsyms_symbol_value(const Elf_Sym * sym)602 static inline unsigned long kallsyms_symbol_value(const Elf_Sym *sym) 603 { 604 return sym->st_value; 605 } 606 #endif 607 608 /* FIXME: It'd be nice to isolate modules during init, too, so they 609 aren't used before they (may) fail. But presently too much code 610 (IDE & SCSI) require entry into the module during init.*/ module_is_live(struct module * mod)611 static inline bool module_is_live(struct module *mod) 612 { 613 return mod->state != MODULE_STATE_GOING; 614 } 615 module_is_coming(struct module * mod)616 static inline bool module_is_coming(struct module *mod) 617 { 618 return mod->state == MODULE_STATE_COMING; 619 } 620 621 struct module *__module_text_address(unsigned long addr); 622 struct module *__module_address(unsigned long addr); 623 bool is_module_address(unsigned long addr); 624 bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr); 625 bool is_module_percpu_address(unsigned long addr); 626 bool is_module_text_address(unsigned long addr); 627 within_module_mem_type(unsigned long addr,const struct module * mod,enum mod_mem_type type)628 static inline bool within_module_mem_type(unsigned long addr, 629 const struct module *mod, 630 enum mod_mem_type type) 631 { 632 unsigned long base, size; 633 634 base = (unsigned long)mod->mem[type].base; 635 size = mod->mem[type].size; 636 return addr - base < size; 637 } 638 within_module_core(unsigned long addr,const struct module * mod)639 static inline bool within_module_core(unsigned long addr, 640 const struct module *mod) 641 { 642 for_class_mod_mem_type(type, core) { 643 if (within_module_mem_type(addr, mod, type)) 644 return true; 645 } 646 return false; 647 } 648 within_module_init(unsigned long addr,const struct module * mod)649 static inline bool within_module_init(unsigned long addr, 650 const struct module *mod) 651 { 652 for_class_mod_mem_type(type, init) { 653 if (within_module_mem_type(addr, mod, type)) 654 return true; 655 } 656 return false; 657 } 658 within_module(unsigned long addr,const struct module * mod)659 static inline bool within_module(unsigned long addr, const struct module *mod) 660 { 661 return within_module_init(addr, mod) || within_module_core(addr, mod); 662 } 663 664 /* Search for module by name: must be in a RCU-sched critical section. */ 665 struct module *find_module(const char *name); 666 667 extern void __noreturn __module_put_and_kthread_exit(struct module *mod, 668 long code); 669 #define module_put_and_kthread_exit(code) __module_put_and_kthread_exit(THIS_MODULE, code) 670 671 #ifdef CONFIG_MODULE_UNLOAD 672 int module_refcount(struct module *mod); 673 void __symbol_put(const char *symbol); 674 #define symbol_put(x) __symbol_put(__stringify(x)) 675 void symbol_put_addr(void *addr); 676 677 /* Sometimes we know we already have a refcount, and it's easier not 678 to handle the error case (which only happens with rmmod --wait). */ 679 extern void __module_get(struct module *module); 680 681 /** 682 * try_module_get() - take module refcount unless module is being removed 683 * @module: the module we should check for 684 * 685 * Only try to get a module reference count if the module is not being removed. 686 * This call will fail if the module is in the process of being removed. 687 * 688 * Care must also be taken to ensure the module exists and is alive prior to 689 * usage of this call. This can be gauranteed through two means: 690 * 691 * 1) Direct protection: you know an earlier caller must have increased the 692 * module reference through __module_get(). This can typically be achieved 693 * by having another entity other than the module itself increment the 694 * module reference count. 695 * 696 * 2) Implied protection: there is an implied protection against module 697 * removal. An example of this is the implied protection used by kernfs / 698 * sysfs. The sysfs store / read file operations are guaranteed to exist 699 * through the use of kernfs's active reference (see kernfs_active()) and a 700 * sysfs / kernfs file removal cannot happen unless the same file is not 701 * active. Therefore, if a sysfs file is being read or written to the module 702 * which created it must still exist. It is therefore safe to use 703 * try_module_get() on module sysfs store / read ops. 704 * 705 * One of the real values to try_module_get() is the module_is_live() check 706 * which ensures that the caller of try_module_get() can yield to userspace 707 * module removal requests and gracefully fail if the module is on its way out. 708 * 709 * Returns true if the reference count was successfully incremented. 710 */ 711 extern bool try_module_get(struct module *module); 712 713 /** 714 * module_put() - release a reference count to a module 715 * @module: the module we should release a reference count for 716 * 717 * If you successfully bump a reference count to a module with try_module_get(), 718 * when you are finished you must call module_put() to release that reference 719 * count. 720 */ 721 extern void module_put(struct module *module); 722 723 #else /*!CONFIG_MODULE_UNLOAD*/ try_module_get(struct module * module)724 static inline bool try_module_get(struct module *module) 725 { 726 return !module || module_is_live(module); 727 } module_put(struct module * module)728 static inline void module_put(struct module *module) 729 { 730 } __module_get(struct module * module)731 static inline void __module_get(struct module *module) 732 { 733 } 734 #define symbol_put(x) do { } while (0) 735 #define symbol_put_addr(p) do { } while (0) 736 737 #endif /* CONFIG_MODULE_UNLOAD */ 738 739 /* This is a #define so the string doesn't get put in every .o file */ 740 #define module_name(mod) \ 741 ({ \ 742 struct module *__mod = (mod); \ 743 __mod ? __mod->name : "kernel"; \ 744 }) 745 746 /* Dereference module function descriptor */ 747 void *dereference_module_function_descriptor(struct module *mod, void *ptr); 748 749 int register_module_notifier(struct notifier_block *nb); 750 int unregister_module_notifier(struct notifier_block *nb); 751 752 extern void print_modules(void); 753 module_requested_async_probing(struct module * module)754 static inline bool module_requested_async_probing(struct module *module) 755 { 756 return module && module->async_probe_requested; 757 } 758 is_livepatch_module(struct module * mod)759 static inline bool is_livepatch_module(struct module *mod) 760 { 761 #ifdef CONFIG_LIVEPATCH 762 return mod->klp; 763 #else 764 return false; 765 #endif 766 } 767 768 void set_module_sig_enforced(void); 769 770 #else /* !CONFIG_MODULES... */ 771 __module_address(unsigned long addr)772 static inline struct module *__module_address(unsigned long addr) 773 { 774 return NULL; 775 } 776 __module_text_address(unsigned long addr)777 static inline struct module *__module_text_address(unsigned long addr) 778 { 779 return NULL; 780 } 781 is_module_address(unsigned long addr)782 static inline bool is_module_address(unsigned long addr) 783 { 784 return false; 785 } 786 is_module_percpu_address(unsigned long addr)787 static inline bool is_module_percpu_address(unsigned long addr) 788 { 789 return false; 790 } 791 __is_module_percpu_address(unsigned long addr,unsigned long * can_addr)792 static inline bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr) 793 { 794 return false; 795 } 796 is_module_text_address(unsigned long addr)797 static inline bool is_module_text_address(unsigned long addr) 798 { 799 return false; 800 } 801 within_module_core(unsigned long addr,const struct module * mod)802 static inline bool within_module_core(unsigned long addr, 803 const struct module *mod) 804 { 805 return false; 806 } 807 within_module_init(unsigned long addr,const struct module * mod)808 static inline bool within_module_init(unsigned long addr, 809 const struct module *mod) 810 { 811 return false; 812 } 813 within_module(unsigned long addr,const struct module * mod)814 static inline bool within_module(unsigned long addr, const struct module *mod) 815 { 816 return false; 817 } 818 819 /* Get/put a kernel symbol (calls should be symmetric) */ 820 #define symbol_get(x) ({ extern typeof(x) x __attribute__((weak,visibility("hidden"))); &(x); }) 821 #define symbol_put(x) do { } while (0) 822 #define symbol_put_addr(x) do { } while (0) 823 __module_get(struct module * module)824 static inline void __module_get(struct module *module) 825 { 826 } 827 try_module_get(struct module * module)828 static inline bool try_module_get(struct module *module) 829 { 830 return true; 831 } 832 module_put(struct module * module)833 static inline void module_put(struct module *module) 834 { 835 } 836 837 #define module_name(mod) "kernel" 838 register_module_notifier(struct notifier_block * nb)839 static inline int register_module_notifier(struct notifier_block *nb) 840 { 841 /* no events will happen anyway, so this can always succeed */ 842 return 0; 843 } 844 unregister_module_notifier(struct notifier_block * nb)845 static inline int unregister_module_notifier(struct notifier_block *nb) 846 { 847 return 0; 848 } 849 850 #define module_put_and_kthread_exit(code) kthread_exit(code) 851 print_modules(void)852 static inline void print_modules(void) 853 { 854 } 855 module_requested_async_probing(struct module * module)856 static inline bool module_requested_async_probing(struct module *module) 857 { 858 return false; 859 } 860 861 set_module_sig_enforced(void)862 static inline void set_module_sig_enforced(void) 863 { 864 } 865 866 /* Dereference module function descriptor */ 867 static inline dereference_module_function_descriptor(struct module * mod,void * ptr)868 void *dereference_module_function_descriptor(struct module *mod, void *ptr) 869 { 870 return ptr; 871 } 872 module_is_coming(struct module * mod)873 static inline bool module_is_coming(struct module *mod) 874 { 875 return false; 876 } 877 #endif /* CONFIG_MODULES */ 878 879 #ifdef CONFIG_SYSFS 880 extern struct kset *module_kset; 881 extern const struct kobj_type module_ktype; 882 #endif /* CONFIG_SYSFS */ 883 884 #define symbol_request(x) try_then_request_module(symbol_get(x), "symbol:" #x) 885 886 /* BELOW HERE ALL THESE ARE OBSOLETE AND WILL VANISH */ 887 888 #define __MODULE_STRING(x) __stringify(x) 889 890 #ifdef CONFIG_GENERIC_BUG 891 void module_bug_finalize(const Elf_Ehdr *, const Elf_Shdr *, 892 struct module *); 893 void module_bug_cleanup(struct module *); 894 895 #else /* !CONFIG_GENERIC_BUG */ 896 module_bug_finalize(const Elf_Ehdr * hdr,const Elf_Shdr * sechdrs,struct module * mod)897 static inline void module_bug_finalize(const Elf_Ehdr *hdr, 898 const Elf_Shdr *sechdrs, 899 struct module *mod) 900 { 901 } module_bug_cleanup(struct module * mod)902 static inline void module_bug_cleanup(struct module *mod) {} 903 #endif /* CONFIG_GENERIC_BUG */ 904 905 #ifdef CONFIG_MITIGATION_RETPOLINE 906 extern bool retpoline_module_ok(bool has_retpoline); 907 #else retpoline_module_ok(bool has_retpoline)908 static inline bool retpoline_module_ok(bool has_retpoline) 909 { 910 return true; 911 } 912 #endif 913 914 #ifdef CONFIG_MODULE_SIG 915 bool is_module_sig_enforced(void); 916 module_sig_ok(struct module * module)917 static inline bool module_sig_ok(struct module *module) 918 { 919 return module->sig_ok; 920 } 921 #else /* !CONFIG_MODULE_SIG */ is_module_sig_enforced(void)922 static inline bool is_module_sig_enforced(void) 923 { 924 return false; 925 } 926 module_sig_ok(struct module * module)927 static inline bool module_sig_ok(struct module *module) 928 { 929 return true; 930 } 931 #endif /* CONFIG_MODULE_SIG */ 932 933 #if defined(CONFIG_MODULES) && defined(CONFIG_KALLSYMS) 934 int module_kallsyms_on_each_symbol(const char *modname, 935 int (*fn)(void *, const char *, unsigned long), 936 void *data); 937 938 /* For kallsyms to ask for address resolution. namebuf should be at 939 * least KSYM_NAME_LEN long: a pointer to namebuf is returned if 940 * found, otherwise NULL. 941 */ 942 int module_address_lookup(unsigned long addr, 943 unsigned long *symbolsize, 944 unsigned long *offset, 945 char **modname, const unsigned char **modbuildid, 946 char *namebuf); 947 int lookup_module_symbol_name(unsigned long addr, char *symname); 948 int lookup_module_symbol_attrs(unsigned long addr, 949 unsigned long *size, 950 unsigned long *offset, 951 char *modname, 952 char *name); 953 954 /* Returns 0 and fills in value, defined and namebuf, or -ERANGE if 955 * symnum out of range. 956 */ 957 int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type, 958 char *name, char *module_name, int *exported); 959 960 /* Look for this name: can be of form module:name. */ 961 unsigned long module_kallsyms_lookup_name(const char *name); 962 963 unsigned long find_kallsyms_symbol_value(struct module *mod, const char *name); 964 965 #else /* CONFIG_MODULES && CONFIG_KALLSYMS */ 966 module_kallsyms_on_each_symbol(const char * modname,int (* fn)(void *,const char *,unsigned long),void * data)967 static inline int module_kallsyms_on_each_symbol(const char *modname, 968 int (*fn)(void *, const char *, unsigned long), 969 void *data) 970 { 971 return -EOPNOTSUPP; 972 } 973 974 /* For kallsyms to ask for address resolution. NULL means not found. */ module_address_lookup(unsigned long addr,unsigned long * symbolsize,unsigned long * offset,char ** modname,const unsigned char ** modbuildid,char * namebuf)975 static inline int module_address_lookup(unsigned long addr, 976 unsigned long *symbolsize, 977 unsigned long *offset, 978 char **modname, 979 const unsigned char **modbuildid, 980 char *namebuf) 981 { 982 return 0; 983 } 984 lookup_module_symbol_name(unsigned long addr,char * symname)985 static inline int lookup_module_symbol_name(unsigned long addr, char *symname) 986 { 987 return -ERANGE; 988 } 989 module_get_kallsym(unsigned int symnum,unsigned long * value,char * type,char * name,char * module_name,int * exported)990 static inline int module_get_kallsym(unsigned int symnum, unsigned long *value, 991 char *type, char *name, 992 char *module_name, int *exported) 993 { 994 return -ERANGE; 995 } 996 module_kallsyms_lookup_name(const char * name)997 static inline unsigned long module_kallsyms_lookup_name(const char *name) 998 { 999 return 0; 1000 } 1001 find_kallsyms_symbol_value(struct module * mod,const char * name)1002 static inline unsigned long find_kallsyms_symbol_value(struct module *mod, 1003 const char *name) 1004 { 1005 return 0; 1006 } 1007 1008 #endif /* CONFIG_MODULES && CONFIG_KALLSYMS */ 1009 1010 #endif /* _LINUX_MODULE_H */ 1011