1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Copyright (C) 2002 Richard Henderson 4 * Copyright (C) 2001 Rusty Russell, 2002, 2010 Rusty Russell IBM. 5 * Copyright (C) 2023 Luis Chamberlain <mcgrof@kernel.org> 6 */ 7 8 #define INCLUDE_VERMAGIC 9 10 #include <linux/export.h> 11 #include <linux/extable.h> 12 #include <linux/moduleloader.h> 13 #include <linux/module_signature.h> 14 #include <linux/trace_events.h> 15 #include <linux/init.h> 16 #include <linux/kallsyms.h> 17 #include <linux/buildid.h> 18 #include <linux/fs.h> 19 #include <linux/kernel.h> 20 #include <linux/kernel_read_file.h> 21 #include <linux/kstrtox.h> 22 #include <linux/slab.h> 23 #include <linux/vmalloc.h> 24 #include <linux/elf.h> 25 #include <linux/seq_file.h> 26 #include <linux/syscalls.h> 27 #include <linux/fcntl.h> 28 #include <linux/rcupdate.h> 29 #include <linux/capability.h> 30 #include <linux/cpu.h> 31 #include <linux/moduleparam.h> 32 #include <linux/errno.h> 33 #include <linux/err.h> 34 #include <linux/vermagic.h> 35 #include <linux/notifier.h> 36 #include <linux/sched.h> 37 #include <linux/device.h> 38 #include <linux/string.h> 39 #include <linux/mutex.h> 40 #include <linux/rculist.h> 41 #include <linux/uaccess.h> 42 #include <asm/cacheflush.h> 43 #include <linux/set_memory.h> 44 #include <asm/mmu_context.h> 45 #include <linux/license.h> 46 #include <asm/sections.h> 47 #include <linux/tracepoint.h> 48 #include <linux/ftrace.h> 49 #include <linux/livepatch.h> 50 #include <linux/async.h> 51 #include <linux/percpu.h> 52 #include <linux/kmemleak.h> 53 #include <linux/jump_label.h> 54 #include <linux/pfn.h> 55 #include <linux/bsearch.h> 56 #include <linux/dynamic_debug.h> 57 #include <linux/audit.h> 58 #include <linux/cfi.h> 59 #include <linux/debugfs.h> 60 #include <uapi/linux/module.h> 61 #include "internal.h" 62 63 #define CREATE_TRACE_POINTS 64 #include <trace/events/module.h> 65 66 /* 67 * Mutex protects: 68 * 1) List of modules (also safely readable with preempt_disable), 69 * 2) module_use links, 70 * 3) mod_tree.addr_min/mod_tree.addr_max. 71 * (delete and add uses RCU list operations). 72 */ 73 DEFINE_MUTEX(module_mutex); 74 LIST_HEAD(modules); 75 76 /* Work queue for freeing init sections in success case */ 77 static void do_free_init(struct work_struct *w); 78 static DECLARE_WORK(init_free_wq, do_free_init); 79 static LLIST_HEAD(init_free_list); 80 81 struct mod_tree_root mod_tree __cacheline_aligned = { 82 .addr_min = -1UL, 83 }; 84 85 struct symsearch { 86 const struct kernel_symbol *start, *stop; 87 const s32 *crcs; 88 enum mod_license license; 89 }; 90 91 /* 92 * Bounds of module memory, for speeding up __module_address. 93 * Protected by module_mutex. 94 */ 95 static void __mod_update_bounds(enum mod_mem_type type __maybe_unused, void *base, 96 unsigned int size, struct mod_tree_root *tree) 97 { 98 unsigned long min = (unsigned long)base; 99 unsigned long max = min + size; 100 101 #ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC 102 if (mod_mem_type_is_core_data(type)) { 103 if (min < tree->data_addr_min) 104 tree->data_addr_min = min; 105 if (max > tree->data_addr_max) 106 tree->data_addr_max = max; 107 return; 108 } 109 #endif 110 if (min < tree->addr_min) 111 tree->addr_min = min; 112 if (max > tree->addr_max) 113 tree->addr_max = max; 114 } 115 116 static void mod_update_bounds(struct module *mod) 117 { 118 for_each_mod_mem_type(type) { 119 struct module_memory *mod_mem = &mod->mem[type]; 120 121 if (mod_mem->size) 122 __mod_update_bounds(type, mod_mem->base, mod_mem->size, &mod_tree); 123 } 124 } 125 126 /* Block module loading/unloading? */ 127 int modules_disabled; 128 core_param(nomodule, modules_disabled, bint, 0); 129 130 /* Waiting for a module to finish initializing? */ 131 static DECLARE_WAIT_QUEUE_HEAD(module_wq); 132 133 static BLOCKING_NOTIFIER_HEAD(module_notify_list); 134 135 int register_module_notifier(struct notifier_block *nb) 136 { 137 return blocking_notifier_chain_register(&module_notify_list, nb); 138 } 139 EXPORT_SYMBOL(register_module_notifier); 140 141 int unregister_module_notifier(struct notifier_block *nb) 142 { 143 return blocking_notifier_chain_unregister(&module_notify_list, nb); 144 } 145 EXPORT_SYMBOL(unregister_module_notifier); 146 147 /* 148 * We require a truly strong try_module_get(): 0 means success. 149 * Otherwise an error is returned due to ongoing or failed 150 * initialization etc. 151 */ 152 static inline int strong_try_module_get(struct module *mod) 153 { 154 BUG_ON(mod && mod->state == MODULE_STATE_UNFORMED); 155 if (mod && mod->state == MODULE_STATE_COMING) 156 return -EBUSY; 157 if (try_module_get(mod)) 158 return 0; 159 else 160 return -ENOENT; 161 } 162 163 static inline void add_taint_module(struct module *mod, unsigned flag, 164 enum lockdep_ok lockdep_ok) 165 { 166 add_taint(flag, lockdep_ok); 167 set_bit(flag, &mod->taints); 168 } 169 170 /* 171 * A thread that wants to hold a reference to a module only while it 172 * is running can call this to safely exit. 173 */ 174 void __noreturn __module_put_and_kthread_exit(struct module *mod, long code) 175 { 176 module_put(mod); 177 kthread_exit(code); 178 } 179 EXPORT_SYMBOL(__module_put_and_kthread_exit); 180 181 /* Find a module section: 0 means not found. */ 182 static unsigned int find_sec(const struct load_info *info, const char *name) 183 { 184 unsigned int i; 185 186 for (i = 1; i < info->hdr->e_shnum; i++) { 187 Elf_Shdr *shdr = &info->sechdrs[i]; 188 /* Alloc bit cleared means "ignore it." */ 189 if ((shdr->sh_flags & SHF_ALLOC) 190 && strcmp(info->secstrings + shdr->sh_name, name) == 0) 191 return i; 192 } 193 return 0; 194 } 195 196 /* Find a module section, or NULL. */ 197 static void *section_addr(const struct load_info *info, const char *name) 198 { 199 /* Section 0 has sh_addr 0. */ 200 return (void *)info->sechdrs[find_sec(info, name)].sh_addr; 201 } 202 203 /* Find a module section, or NULL. Fill in number of "objects" in section. */ 204 static void *section_objs(const struct load_info *info, 205 const char *name, 206 size_t object_size, 207 unsigned int *num) 208 { 209 unsigned int sec = find_sec(info, name); 210 211 /* Section 0 has sh_addr 0 and sh_size 0. */ 212 *num = info->sechdrs[sec].sh_size / object_size; 213 return (void *)info->sechdrs[sec].sh_addr; 214 } 215 216 /* Find a module section: 0 means not found. Ignores SHF_ALLOC flag. */ 217 static unsigned int find_any_sec(const struct load_info *info, const char *name) 218 { 219 unsigned int i; 220 221 for (i = 1; i < info->hdr->e_shnum; i++) { 222 Elf_Shdr *shdr = &info->sechdrs[i]; 223 if (strcmp(info->secstrings + shdr->sh_name, name) == 0) 224 return i; 225 } 226 return 0; 227 } 228 229 /* 230 * Find a module section, or NULL. Fill in number of "objects" in section. 231 * Ignores SHF_ALLOC flag. 232 */ 233 static __maybe_unused void *any_section_objs(const struct load_info *info, 234 const char *name, 235 size_t object_size, 236 unsigned int *num) 237 { 238 unsigned int sec = find_any_sec(info, name); 239 240 /* Section 0 has sh_addr 0 and sh_size 0. */ 241 *num = info->sechdrs[sec].sh_size / object_size; 242 return (void *)info->sechdrs[sec].sh_addr; 243 } 244 245 #ifndef CONFIG_MODVERSIONS 246 #define symversion(base, idx) NULL 247 #else 248 #define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL) 249 #endif 250 251 static const char *kernel_symbol_name(const struct kernel_symbol *sym) 252 { 253 #ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS 254 return offset_to_ptr(&sym->name_offset); 255 #else 256 return sym->name; 257 #endif 258 } 259 260 static const char *kernel_symbol_namespace(const struct kernel_symbol *sym) 261 { 262 #ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS 263 if (!sym->namespace_offset) 264 return NULL; 265 return offset_to_ptr(&sym->namespace_offset); 266 #else 267 return sym->namespace; 268 #endif 269 } 270 271 int cmp_name(const void *name, const void *sym) 272 { 273 return strcmp(name, kernel_symbol_name(sym)); 274 } 275 276 static bool find_exported_symbol_in_section(const struct symsearch *syms, 277 struct module *owner, 278 struct find_symbol_arg *fsa) 279 { 280 struct kernel_symbol *sym; 281 282 if (!fsa->gplok && syms->license == GPL_ONLY) 283 return false; 284 285 sym = bsearch(fsa->name, syms->start, syms->stop - syms->start, 286 sizeof(struct kernel_symbol), cmp_name); 287 if (!sym) 288 return false; 289 290 fsa->owner = owner; 291 fsa->crc = symversion(syms->crcs, sym - syms->start); 292 fsa->sym = sym; 293 fsa->license = syms->license; 294 295 return true; 296 } 297 298 /* 299 * Find an exported symbol and return it, along with, (optional) crc and 300 * (optional) module which owns it. Needs preempt disabled or module_mutex. 301 */ 302 bool find_symbol(struct find_symbol_arg *fsa) 303 { 304 static const struct symsearch arr[] = { 305 { __start___ksymtab, __stop___ksymtab, __start___kcrctab, 306 NOT_GPL_ONLY }, 307 { __start___ksymtab_gpl, __stop___ksymtab_gpl, 308 __start___kcrctab_gpl, 309 GPL_ONLY }, 310 }; 311 struct module *mod; 312 unsigned int i; 313 314 module_assert_mutex_or_preempt(); 315 316 for (i = 0; i < ARRAY_SIZE(arr); i++) 317 if (find_exported_symbol_in_section(&arr[i], NULL, fsa)) 318 return true; 319 320 list_for_each_entry_rcu(mod, &modules, list, 321 lockdep_is_held(&module_mutex)) { 322 struct symsearch arr[] = { 323 { mod->syms, mod->syms + mod->num_syms, mod->crcs, 324 NOT_GPL_ONLY }, 325 { mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms, 326 mod->gpl_crcs, 327 GPL_ONLY }, 328 }; 329 330 if (mod->state == MODULE_STATE_UNFORMED) 331 continue; 332 333 for (i = 0; i < ARRAY_SIZE(arr); i++) 334 if (find_exported_symbol_in_section(&arr[i], mod, fsa)) 335 return true; 336 } 337 338 pr_debug("Failed to find symbol %s\n", fsa->name); 339 return false; 340 } 341 342 /* 343 * Search for module by name: must hold module_mutex (or preempt disabled 344 * for read-only access). 345 */ 346 struct module *find_module_all(const char *name, size_t len, 347 bool even_unformed) 348 { 349 struct module *mod; 350 351 module_assert_mutex_or_preempt(); 352 353 list_for_each_entry_rcu(mod, &modules, list, 354 lockdep_is_held(&module_mutex)) { 355 if (!even_unformed && mod->state == MODULE_STATE_UNFORMED) 356 continue; 357 if (strlen(mod->name) == len && !memcmp(mod->name, name, len)) 358 return mod; 359 } 360 return NULL; 361 } 362 363 struct module *find_module(const char *name) 364 { 365 return find_module_all(name, strlen(name), false); 366 } 367 368 #ifdef CONFIG_SMP 369 370 static inline void __percpu *mod_percpu(struct module *mod) 371 { 372 return mod->percpu; 373 } 374 375 static int percpu_modalloc(struct module *mod, struct load_info *info) 376 { 377 Elf_Shdr *pcpusec = &info->sechdrs[info->index.pcpu]; 378 unsigned long align = pcpusec->sh_addralign; 379 380 if (!pcpusec->sh_size) 381 return 0; 382 383 if (align > PAGE_SIZE) { 384 pr_warn("%s: per-cpu alignment %li > %li\n", 385 mod->name, align, PAGE_SIZE); 386 align = PAGE_SIZE; 387 } 388 389 mod->percpu = __alloc_reserved_percpu(pcpusec->sh_size, align); 390 if (!mod->percpu) { 391 pr_warn("%s: Could not allocate %lu bytes percpu data\n", 392 mod->name, (unsigned long)pcpusec->sh_size); 393 return -ENOMEM; 394 } 395 mod->percpu_size = pcpusec->sh_size; 396 return 0; 397 } 398 399 static void percpu_modfree(struct module *mod) 400 { 401 free_percpu(mod->percpu); 402 } 403 404 static unsigned int find_pcpusec(struct load_info *info) 405 { 406 return find_sec(info, ".data..percpu"); 407 } 408 409 static void percpu_modcopy(struct module *mod, 410 const void *from, unsigned long size) 411 { 412 int cpu; 413 414 for_each_possible_cpu(cpu) 415 memcpy(per_cpu_ptr(mod->percpu, cpu), from, size); 416 } 417 418 bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr) 419 { 420 struct module *mod; 421 unsigned int cpu; 422 423 preempt_disable(); 424 425 list_for_each_entry_rcu(mod, &modules, list) { 426 if (mod->state == MODULE_STATE_UNFORMED) 427 continue; 428 if (!mod->percpu_size) 429 continue; 430 for_each_possible_cpu(cpu) { 431 void *start = per_cpu_ptr(mod->percpu, cpu); 432 void *va = (void *)addr; 433 434 if (va >= start && va < start + mod->percpu_size) { 435 if (can_addr) { 436 *can_addr = (unsigned long) (va - start); 437 *can_addr += (unsigned long) 438 per_cpu_ptr(mod->percpu, 439 get_boot_cpu_id()); 440 } 441 preempt_enable(); 442 return true; 443 } 444 } 445 } 446 447 preempt_enable(); 448 return false; 449 } 450 451 /** 452 * is_module_percpu_address() - test whether address is from module static percpu 453 * @addr: address to test 454 * 455 * Test whether @addr belongs to module static percpu area. 456 * 457 * Return: %true if @addr is from module static percpu area 458 */ 459 bool is_module_percpu_address(unsigned long addr) 460 { 461 return __is_module_percpu_address(addr, NULL); 462 } 463 464 #else /* ... !CONFIG_SMP */ 465 466 static inline void __percpu *mod_percpu(struct module *mod) 467 { 468 return NULL; 469 } 470 static int percpu_modalloc(struct module *mod, struct load_info *info) 471 { 472 /* UP modules shouldn't have this section: ENOMEM isn't quite right */ 473 if (info->sechdrs[info->index.pcpu].sh_size != 0) 474 return -ENOMEM; 475 return 0; 476 } 477 static inline void percpu_modfree(struct module *mod) 478 { 479 } 480 static unsigned int find_pcpusec(struct load_info *info) 481 { 482 return 0; 483 } 484 static inline void percpu_modcopy(struct module *mod, 485 const void *from, unsigned long size) 486 { 487 /* pcpusec should be 0, and size of that section should be 0. */ 488 BUG_ON(size != 0); 489 } 490 bool is_module_percpu_address(unsigned long addr) 491 { 492 return false; 493 } 494 495 bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr) 496 { 497 return false; 498 } 499 500 #endif /* CONFIG_SMP */ 501 502 #define MODINFO_ATTR(field) \ 503 static void setup_modinfo_##field(struct module *mod, const char *s) \ 504 { \ 505 mod->field = kstrdup(s, GFP_KERNEL); \ 506 } \ 507 static ssize_t show_modinfo_##field(struct module_attribute *mattr, \ 508 struct module_kobject *mk, char *buffer) \ 509 { \ 510 return scnprintf(buffer, PAGE_SIZE, "%s\n", mk->mod->field); \ 511 } \ 512 static int modinfo_##field##_exists(struct module *mod) \ 513 { \ 514 return mod->field != NULL; \ 515 } \ 516 static void free_modinfo_##field(struct module *mod) \ 517 { \ 518 kfree(mod->field); \ 519 mod->field = NULL; \ 520 } \ 521 static struct module_attribute modinfo_##field = { \ 522 .attr = { .name = __stringify(field), .mode = 0444 }, \ 523 .show = show_modinfo_##field, \ 524 .setup = setup_modinfo_##field, \ 525 .test = modinfo_##field##_exists, \ 526 .free = free_modinfo_##field, \ 527 }; 528 529 MODINFO_ATTR(version); 530 MODINFO_ATTR(srcversion); 531 532 static struct { 533 char name[MODULE_NAME_LEN + 1]; 534 char taints[MODULE_FLAGS_BUF_SIZE]; 535 } last_unloaded_module; 536 537 #ifdef CONFIG_MODULE_UNLOAD 538 539 EXPORT_TRACEPOINT_SYMBOL(module_get); 540 541 /* MODULE_REF_BASE is the base reference count by kmodule loader. */ 542 #define MODULE_REF_BASE 1 543 544 /* Init the unload section of the module. */ 545 static int module_unload_init(struct module *mod) 546 { 547 /* 548 * Initialize reference counter to MODULE_REF_BASE. 549 * refcnt == 0 means module is going. 550 */ 551 atomic_set(&mod->refcnt, MODULE_REF_BASE); 552 553 INIT_LIST_HEAD(&mod->source_list); 554 INIT_LIST_HEAD(&mod->target_list); 555 556 /* Hold reference count during initialization. */ 557 atomic_inc(&mod->refcnt); 558 559 return 0; 560 } 561 562 /* Does a already use b? */ 563 static int already_uses(struct module *a, struct module *b) 564 { 565 struct module_use *use; 566 567 list_for_each_entry(use, &b->source_list, source_list) { 568 if (use->source == a) 569 return 1; 570 } 571 pr_debug("%s does not use %s!\n", a->name, b->name); 572 return 0; 573 } 574 575 /* 576 * Module a uses b 577 * - we add 'a' as a "source", 'b' as a "target" of module use 578 * - the module_use is added to the list of 'b' sources (so 579 * 'b' can walk the list to see who sourced them), and of 'a' 580 * targets (so 'a' can see what modules it targets). 581 */ 582 static int add_module_usage(struct module *a, struct module *b) 583 { 584 struct module_use *use; 585 586 pr_debug("Allocating new usage for %s.\n", a->name); 587 use = kmalloc(sizeof(*use), GFP_ATOMIC); 588 if (!use) 589 return -ENOMEM; 590 591 use->source = a; 592 use->target = b; 593 list_add(&use->source_list, &b->source_list); 594 list_add(&use->target_list, &a->target_list); 595 return 0; 596 } 597 598 /* Module a uses b: caller needs module_mutex() */ 599 static int ref_module(struct module *a, struct module *b) 600 { 601 int err; 602 603 if (b == NULL || already_uses(a, b)) 604 return 0; 605 606 /* If module isn't available, we fail. */ 607 err = strong_try_module_get(b); 608 if (err) 609 return err; 610 611 err = add_module_usage(a, b); 612 if (err) { 613 module_put(b); 614 return err; 615 } 616 return 0; 617 } 618 619 /* Clear the unload stuff of the module. */ 620 static void module_unload_free(struct module *mod) 621 { 622 struct module_use *use, *tmp; 623 624 mutex_lock(&module_mutex); 625 list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) { 626 struct module *i = use->target; 627 pr_debug("%s unusing %s\n", mod->name, i->name); 628 module_put(i); 629 list_del(&use->source_list); 630 list_del(&use->target_list); 631 kfree(use); 632 } 633 mutex_unlock(&module_mutex); 634 } 635 636 #ifdef CONFIG_MODULE_FORCE_UNLOAD 637 static inline int try_force_unload(unsigned int flags) 638 { 639 int ret = (flags & O_TRUNC); 640 if (ret) 641 add_taint(TAINT_FORCED_RMMOD, LOCKDEP_NOW_UNRELIABLE); 642 return ret; 643 } 644 #else 645 static inline int try_force_unload(unsigned int flags) 646 { 647 return 0; 648 } 649 #endif /* CONFIG_MODULE_FORCE_UNLOAD */ 650 651 /* Try to release refcount of module, 0 means success. */ 652 static int try_release_module_ref(struct module *mod) 653 { 654 int ret; 655 656 /* Try to decrement refcnt which we set at loading */ 657 ret = atomic_sub_return(MODULE_REF_BASE, &mod->refcnt); 658 BUG_ON(ret < 0); 659 if (ret) 660 /* Someone can put this right now, recover with checking */ 661 ret = atomic_add_unless(&mod->refcnt, MODULE_REF_BASE, 0); 662 663 return ret; 664 } 665 666 static int try_stop_module(struct module *mod, int flags, int *forced) 667 { 668 /* If it's not unused, quit unless we're forcing. */ 669 if (try_release_module_ref(mod) != 0) { 670 *forced = try_force_unload(flags); 671 if (!(*forced)) 672 return -EWOULDBLOCK; 673 } 674 675 /* Mark it as dying. */ 676 mod->state = MODULE_STATE_GOING; 677 678 return 0; 679 } 680 681 /** 682 * module_refcount() - return the refcount or -1 if unloading 683 * @mod: the module we're checking 684 * 685 * Return: 686 * -1 if the module is in the process of unloading 687 * otherwise the number of references in the kernel to the module 688 */ 689 int module_refcount(struct module *mod) 690 { 691 return atomic_read(&mod->refcnt) - MODULE_REF_BASE; 692 } 693 EXPORT_SYMBOL(module_refcount); 694 695 /* This exists whether we can unload or not */ 696 static void free_module(struct module *mod); 697 698 SYSCALL_DEFINE2(delete_module, const char __user *, name_user, 699 unsigned int, flags) 700 { 701 struct module *mod; 702 char name[MODULE_NAME_LEN]; 703 char buf[MODULE_FLAGS_BUF_SIZE]; 704 int ret, forced = 0; 705 706 if (!capable(CAP_SYS_MODULE) || modules_disabled) 707 return -EPERM; 708 709 if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0) 710 return -EFAULT; 711 name[MODULE_NAME_LEN-1] = '\0'; 712 713 audit_log_kern_module(name); 714 715 if (mutex_lock_interruptible(&module_mutex) != 0) 716 return -EINTR; 717 718 mod = find_module(name); 719 if (!mod) { 720 ret = -ENOENT; 721 goto out; 722 } 723 724 if (!list_empty(&mod->source_list)) { 725 /* Other modules depend on us: get rid of them first. */ 726 ret = -EWOULDBLOCK; 727 goto out; 728 } 729 730 /* Doing init or already dying? */ 731 if (mod->state != MODULE_STATE_LIVE) { 732 /* FIXME: if (force), slam module count damn the torpedoes */ 733 pr_debug("%s already dying\n", mod->name); 734 ret = -EBUSY; 735 goto out; 736 } 737 738 /* If it has an init func, it must have an exit func to unload */ 739 if (mod->init && !mod->exit) { 740 forced = try_force_unload(flags); 741 if (!forced) { 742 /* This module can't be removed */ 743 ret = -EBUSY; 744 goto out; 745 } 746 } 747 748 ret = try_stop_module(mod, flags, &forced); 749 if (ret != 0) 750 goto out; 751 752 mutex_unlock(&module_mutex); 753 /* Final destruction now no one is using it. */ 754 if (mod->exit != NULL) 755 mod->exit(); 756 blocking_notifier_call_chain(&module_notify_list, 757 MODULE_STATE_GOING, mod); 758 klp_module_going(mod); 759 ftrace_release_mod(mod); 760 761 async_synchronize_full(); 762 763 /* Store the name and taints of the last unloaded module for diagnostic purposes */ 764 strscpy(last_unloaded_module.name, mod->name, sizeof(last_unloaded_module.name)); 765 strscpy(last_unloaded_module.taints, module_flags(mod, buf, false), sizeof(last_unloaded_module.taints)); 766 767 free_module(mod); 768 /* someone could wait for the module in add_unformed_module() */ 769 wake_up_all(&module_wq); 770 return 0; 771 out: 772 mutex_unlock(&module_mutex); 773 return ret; 774 } 775 776 void __symbol_put(const char *symbol) 777 { 778 struct find_symbol_arg fsa = { 779 .name = symbol, 780 .gplok = true, 781 }; 782 783 preempt_disable(); 784 BUG_ON(!find_symbol(&fsa)); 785 module_put(fsa.owner); 786 preempt_enable(); 787 } 788 EXPORT_SYMBOL(__symbol_put); 789 790 /* Note this assumes addr is a function, which it currently always is. */ 791 void symbol_put_addr(void *addr) 792 { 793 struct module *modaddr; 794 unsigned long a = (unsigned long)dereference_function_descriptor(addr); 795 796 if (core_kernel_text(a)) 797 return; 798 799 /* 800 * Even though we hold a reference on the module; we still need to 801 * disable preemption in order to safely traverse the data structure. 802 */ 803 preempt_disable(); 804 modaddr = __module_text_address(a); 805 BUG_ON(!modaddr); 806 module_put(modaddr); 807 preempt_enable(); 808 } 809 EXPORT_SYMBOL_GPL(symbol_put_addr); 810 811 static ssize_t show_refcnt(struct module_attribute *mattr, 812 struct module_kobject *mk, char *buffer) 813 { 814 return sprintf(buffer, "%i\n", module_refcount(mk->mod)); 815 } 816 817 static struct module_attribute modinfo_refcnt = 818 __ATTR(refcnt, 0444, show_refcnt, NULL); 819 820 void __module_get(struct module *module) 821 { 822 if (module) { 823 preempt_disable(); 824 atomic_inc(&module->refcnt); 825 trace_module_get(module, _RET_IP_); 826 preempt_enable(); 827 } 828 } 829 EXPORT_SYMBOL(__module_get); 830 831 bool try_module_get(struct module *module) 832 { 833 bool ret = true; 834 835 if (module) { 836 preempt_disable(); 837 /* Note: here, we can fail to get a reference */ 838 if (likely(module_is_live(module) && 839 atomic_inc_not_zero(&module->refcnt) != 0)) 840 trace_module_get(module, _RET_IP_); 841 else 842 ret = false; 843 844 preempt_enable(); 845 } 846 return ret; 847 } 848 EXPORT_SYMBOL(try_module_get); 849 850 void module_put(struct module *module) 851 { 852 int ret; 853 854 if (module) { 855 preempt_disable(); 856 ret = atomic_dec_if_positive(&module->refcnt); 857 WARN_ON(ret < 0); /* Failed to put refcount */ 858 trace_module_put(module, _RET_IP_); 859 preempt_enable(); 860 } 861 } 862 EXPORT_SYMBOL(module_put); 863 864 #else /* !CONFIG_MODULE_UNLOAD */ 865 static inline void module_unload_free(struct module *mod) 866 { 867 } 868 869 static int ref_module(struct module *a, struct module *b) 870 { 871 return strong_try_module_get(b); 872 } 873 874 static inline int module_unload_init(struct module *mod) 875 { 876 return 0; 877 } 878 #endif /* CONFIG_MODULE_UNLOAD */ 879 880 size_t module_flags_taint(unsigned long taints, char *buf) 881 { 882 size_t l = 0; 883 int i; 884 885 for (i = 0; i < TAINT_FLAGS_COUNT; i++) { 886 if (taint_flags[i].module && test_bit(i, &taints)) 887 buf[l++] = taint_flags[i].c_true; 888 } 889 890 return l; 891 } 892 893 static ssize_t show_initstate(struct module_attribute *mattr, 894 struct module_kobject *mk, char *buffer) 895 { 896 const char *state = "unknown"; 897 898 switch (mk->mod->state) { 899 case MODULE_STATE_LIVE: 900 state = "live"; 901 break; 902 case MODULE_STATE_COMING: 903 state = "coming"; 904 break; 905 case MODULE_STATE_GOING: 906 state = "going"; 907 break; 908 default: 909 BUG(); 910 } 911 return sprintf(buffer, "%s\n", state); 912 } 913 914 static struct module_attribute modinfo_initstate = 915 __ATTR(initstate, 0444, show_initstate, NULL); 916 917 static ssize_t store_uevent(struct module_attribute *mattr, 918 struct module_kobject *mk, 919 const char *buffer, size_t count) 920 { 921 int rc; 922 923 rc = kobject_synth_uevent(&mk->kobj, buffer, count); 924 return rc ? rc : count; 925 } 926 927 struct module_attribute module_uevent = 928 __ATTR(uevent, 0200, NULL, store_uevent); 929 930 static ssize_t show_coresize(struct module_attribute *mattr, 931 struct module_kobject *mk, char *buffer) 932 { 933 unsigned int size = mk->mod->mem[MOD_TEXT].size; 934 935 if (!IS_ENABLED(CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC)) { 936 for_class_mod_mem_type(type, core_data) 937 size += mk->mod->mem[type].size; 938 } 939 return sprintf(buffer, "%u\n", size); 940 } 941 942 static struct module_attribute modinfo_coresize = 943 __ATTR(coresize, 0444, show_coresize, NULL); 944 945 #ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC 946 static ssize_t show_datasize(struct module_attribute *mattr, 947 struct module_kobject *mk, char *buffer) 948 { 949 unsigned int size = 0; 950 951 for_class_mod_mem_type(type, core_data) 952 size += mk->mod->mem[type].size; 953 return sprintf(buffer, "%u\n", size); 954 } 955 956 static struct module_attribute modinfo_datasize = 957 __ATTR(datasize, 0444, show_datasize, NULL); 958 #endif 959 960 static ssize_t show_initsize(struct module_attribute *mattr, 961 struct module_kobject *mk, char *buffer) 962 { 963 unsigned int size = 0; 964 965 for_class_mod_mem_type(type, init) 966 size += mk->mod->mem[type].size; 967 return sprintf(buffer, "%u\n", size); 968 } 969 970 static struct module_attribute modinfo_initsize = 971 __ATTR(initsize, 0444, show_initsize, NULL); 972 973 static ssize_t show_taint(struct module_attribute *mattr, 974 struct module_kobject *mk, char *buffer) 975 { 976 size_t l; 977 978 l = module_flags_taint(mk->mod->taints, buffer); 979 buffer[l++] = '\n'; 980 return l; 981 } 982 983 static struct module_attribute modinfo_taint = 984 __ATTR(taint, 0444, show_taint, NULL); 985 986 struct module_attribute *modinfo_attrs[] = { 987 &module_uevent, 988 &modinfo_version, 989 &modinfo_srcversion, 990 &modinfo_initstate, 991 &modinfo_coresize, 992 #ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC 993 &modinfo_datasize, 994 #endif 995 &modinfo_initsize, 996 &modinfo_taint, 997 #ifdef CONFIG_MODULE_UNLOAD 998 &modinfo_refcnt, 999 #endif 1000 NULL, 1001 }; 1002 1003 size_t modinfo_attrs_count = ARRAY_SIZE(modinfo_attrs); 1004 1005 static const char vermagic[] = VERMAGIC_STRING; 1006 1007 int try_to_force_load(struct module *mod, const char *reason) 1008 { 1009 #ifdef CONFIG_MODULE_FORCE_LOAD 1010 if (!test_taint(TAINT_FORCED_MODULE)) 1011 pr_warn("%s: %s: kernel tainted.\n", mod->name, reason); 1012 add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_NOW_UNRELIABLE); 1013 return 0; 1014 #else 1015 return -ENOEXEC; 1016 #endif 1017 } 1018 1019 /* Parse tag=value strings from .modinfo section */ 1020 char *module_next_tag_pair(char *string, unsigned long *secsize) 1021 { 1022 /* Skip non-zero chars */ 1023 while (string[0]) { 1024 string++; 1025 if ((*secsize)-- <= 1) 1026 return NULL; 1027 } 1028 1029 /* Skip any zero padding. */ 1030 while (!string[0]) { 1031 string++; 1032 if ((*secsize)-- <= 1) 1033 return NULL; 1034 } 1035 return string; 1036 } 1037 1038 static char *get_next_modinfo(const struct load_info *info, const char *tag, 1039 char *prev) 1040 { 1041 char *p; 1042 unsigned int taglen = strlen(tag); 1043 Elf_Shdr *infosec = &info->sechdrs[info->index.info]; 1044 unsigned long size = infosec->sh_size; 1045 1046 /* 1047 * get_modinfo() calls made before rewrite_section_headers() 1048 * must use sh_offset, as sh_addr isn't set! 1049 */ 1050 char *modinfo = (char *)info->hdr + infosec->sh_offset; 1051 1052 if (prev) { 1053 size -= prev - modinfo; 1054 modinfo = module_next_tag_pair(prev, &size); 1055 } 1056 1057 for (p = modinfo; p; p = module_next_tag_pair(p, &size)) { 1058 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=') 1059 return p + taglen + 1; 1060 } 1061 return NULL; 1062 } 1063 1064 static char *get_modinfo(const struct load_info *info, const char *tag) 1065 { 1066 return get_next_modinfo(info, tag, NULL); 1067 } 1068 1069 static int verify_namespace_is_imported(const struct load_info *info, 1070 const struct kernel_symbol *sym, 1071 struct module *mod) 1072 { 1073 const char *namespace; 1074 char *imported_namespace; 1075 1076 namespace = kernel_symbol_namespace(sym); 1077 if (namespace && namespace[0]) { 1078 for_each_modinfo_entry(imported_namespace, info, "import_ns") { 1079 if (strcmp(namespace, imported_namespace) == 0) 1080 return 0; 1081 } 1082 #ifdef CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS 1083 pr_warn( 1084 #else 1085 pr_err( 1086 #endif 1087 "%s: module uses symbol (%s) from namespace %s, but does not import it.\n", 1088 mod->name, kernel_symbol_name(sym), namespace); 1089 #ifndef CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS 1090 return -EINVAL; 1091 #endif 1092 } 1093 return 0; 1094 } 1095 1096 static bool inherit_taint(struct module *mod, struct module *owner, const char *name) 1097 { 1098 if (!owner || !test_bit(TAINT_PROPRIETARY_MODULE, &owner->taints)) 1099 return true; 1100 1101 if (mod->using_gplonly_symbols) { 1102 pr_err("%s: module using GPL-only symbols uses symbols %s from proprietary module %s.\n", 1103 mod->name, name, owner->name); 1104 return false; 1105 } 1106 1107 if (!test_bit(TAINT_PROPRIETARY_MODULE, &mod->taints)) { 1108 pr_warn("%s: module uses symbols %s from proprietary module %s, inheriting taint.\n", 1109 mod->name, name, owner->name); 1110 set_bit(TAINT_PROPRIETARY_MODULE, &mod->taints); 1111 } 1112 return true; 1113 } 1114 1115 /* Resolve a symbol for this module. I.e. if we find one, record usage. */ 1116 static const struct kernel_symbol *resolve_symbol(struct module *mod, 1117 const struct load_info *info, 1118 const char *name, 1119 char ownername[]) 1120 { 1121 struct find_symbol_arg fsa = { 1122 .name = name, 1123 .gplok = !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), 1124 .warn = true, 1125 }; 1126 int err; 1127 1128 /* 1129 * The module_mutex should not be a heavily contended lock; 1130 * if we get the occasional sleep here, we'll go an extra iteration 1131 * in the wait_event_interruptible(), which is harmless. 1132 */ 1133 sched_annotate_sleep(); 1134 mutex_lock(&module_mutex); 1135 if (!find_symbol(&fsa)) 1136 goto unlock; 1137 1138 if (fsa.license == GPL_ONLY) 1139 mod->using_gplonly_symbols = true; 1140 1141 if (!inherit_taint(mod, fsa.owner, name)) { 1142 fsa.sym = NULL; 1143 goto getname; 1144 } 1145 1146 if (!check_version(info, name, mod, fsa.crc)) { 1147 fsa.sym = ERR_PTR(-EINVAL); 1148 goto getname; 1149 } 1150 1151 err = verify_namespace_is_imported(info, fsa.sym, mod); 1152 if (err) { 1153 fsa.sym = ERR_PTR(err); 1154 goto getname; 1155 } 1156 1157 err = ref_module(mod, fsa.owner); 1158 if (err) { 1159 fsa.sym = ERR_PTR(err); 1160 goto getname; 1161 } 1162 1163 getname: 1164 /* We must make copy under the lock if we failed to get ref. */ 1165 strncpy(ownername, module_name(fsa.owner), MODULE_NAME_LEN); 1166 unlock: 1167 mutex_unlock(&module_mutex); 1168 return fsa.sym; 1169 } 1170 1171 static const struct kernel_symbol * 1172 resolve_symbol_wait(struct module *mod, 1173 const struct load_info *info, 1174 const char *name) 1175 { 1176 const struct kernel_symbol *ksym; 1177 char owner[MODULE_NAME_LEN]; 1178 1179 if (wait_event_interruptible_timeout(module_wq, 1180 !IS_ERR(ksym = resolve_symbol(mod, info, name, owner)) 1181 || PTR_ERR(ksym) != -EBUSY, 1182 30 * HZ) <= 0) { 1183 pr_warn("%s: gave up waiting for init of module %s.\n", 1184 mod->name, owner); 1185 } 1186 return ksym; 1187 } 1188 1189 void __weak module_memfree(void *module_region) 1190 { 1191 /* 1192 * This memory may be RO, and freeing RO memory in an interrupt is not 1193 * supported by vmalloc. 1194 */ 1195 WARN_ON(in_interrupt()); 1196 vfree(module_region); 1197 } 1198 1199 void __weak module_arch_cleanup(struct module *mod) 1200 { 1201 } 1202 1203 void __weak module_arch_freeing_init(struct module *mod) 1204 { 1205 } 1206 1207 static bool mod_mem_use_vmalloc(enum mod_mem_type type) 1208 { 1209 return IS_ENABLED(CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC) && 1210 mod_mem_type_is_core_data(type); 1211 } 1212 1213 static void *module_memory_alloc(unsigned int size, enum mod_mem_type type) 1214 { 1215 if (mod_mem_use_vmalloc(type)) 1216 return vzalloc(size); 1217 return module_alloc(size); 1218 } 1219 1220 static void module_memory_free(void *ptr, enum mod_mem_type type) 1221 { 1222 if (mod_mem_use_vmalloc(type)) 1223 vfree(ptr); 1224 else 1225 module_memfree(ptr); 1226 } 1227 1228 static void free_mod_mem(struct module *mod) 1229 { 1230 for_each_mod_mem_type(type) { 1231 struct module_memory *mod_mem = &mod->mem[type]; 1232 1233 if (type == MOD_DATA) 1234 continue; 1235 1236 /* Free lock-classes; relies on the preceding sync_rcu(). */ 1237 lockdep_free_key_range(mod_mem->base, mod_mem->size); 1238 if (mod_mem->size) 1239 module_memory_free(mod_mem->base, type); 1240 } 1241 1242 /* MOD_DATA hosts mod, so free it at last */ 1243 lockdep_free_key_range(mod->mem[MOD_DATA].base, mod->mem[MOD_DATA].size); 1244 module_memory_free(mod->mem[MOD_DATA].base, MOD_DATA); 1245 } 1246 1247 /* Free a module, remove from lists, etc. */ 1248 static void free_module(struct module *mod) 1249 { 1250 trace_module_free(mod); 1251 1252 mod_sysfs_teardown(mod); 1253 1254 /* 1255 * We leave it in list to prevent duplicate loads, but make sure 1256 * that noone uses it while it's being deconstructed. 1257 */ 1258 mutex_lock(&module_mutex); 1259 mod->state = MODULE_STATE_UNFORMED; 1260 mutex_unlock(&module_mutex); 1261 1262 /* Arch-specific cleanup. */ 1263 module_arch_cleanup(mod); 1264 1265 /* Module unload stuff */ 1266 module_unload_free(mod); 1267 1268 /* Free any allocated parameters. */ 1269 destroy_params(mod->kp, mod->num_kp); 1270 1271 if (is_livepatch_module(mod)) 1272 free_module_elf(mod); 1273 1274 /* Now we can delete it from the lists */ 1275 mutex_lock(&module_mutex); 1276 /* Unlink carefully: kallsyms could be walking list. */ 1277 list_del_rcu(&mod->list); 1278 mod_tree_remove(mod); 1279 /* Remove this module from bug list, this uses list_del_rcu */ 1280 module_bug_cleanup(mod); 1281 /* Wait for RCU-sched synchronizing before releasing mod->list and buglist. */ 1282 synchronize_rcu(); 1283 if (try_add_tainted_module(mod)) 1284 pr_err("%s: adding tainted module to the unloaded tainted modules list failed.\n", 1285 mod->name); 1286 mutex_unlock(&module_mutex); 1287 1288 /* This may be empty, but that's OK */ 1289 module_arch_freeing_init(mod); 1290 kfree(mod->args); 1291 percpu_modfree(mod); 1292 1293 free_mod_mem(mod); 1294 } 1295 1296 void *__symbol_get(const char *symbol) 1297 { 1298 struct find_symbol_arg fsa = { 1299 .name = symbol, 1300 .gplok = true, 1301 .warn = true, 1302 }; 1303 1304 preempt_disable(); 1305 if (!find_symbol(&fsa) || strong_try_module_get(fsa.owner)) { 1306 preempt_enable(); 1307 return NULL; 1308 } 1309 preempt_enable(); 1310 return (void *)kernel_symbol_value(fsa.sym); 1311 } 1312 EXPORT_SYMBOL_GPL(__symbol_get); 1313 1314 /* 1315 * Ensure that an exported symbol [global namespace] does not already exist 1316 * in the kernel or in some other module's exported symbol table. 1317 * 1318 * You must hold the module_mutex. 1319 */ 1320 static int verify_exported_symbols(struct module *mod) 1321 { 1322 unsigned int i; 1323 const struct kernel_symbol *s; 1324 struct { 1325 const struct kernel_symbol *sym; 1326 unsigned int num; 1327 } arr[] = { 1328 { mod->syms, mod->num_syms }, 1329 { mod->gpl_syms, mod->num_gpl_syms }, 1330 }; 1331 1332 for (i = 0; i < ARRAY_SIZE(arr); i++) { 1333 for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) { 1334 struct find_symbol_arg fsa = { 1335 .name = kernel_symbol_name(s), 1336 .gplok = true, 1337 }; 1338 if (find_symbol(&fsa)) { 1339 pr_err("%s: exports duplicate symbol %s" 1340 " (owned by %s)\n", 1341 mod->name, kernel_symbol_name(s), 1342 module_name(fsa.owner)); 1343 return -ENOEXEC; 1344 } 1345 } 1346 } 1347 return 0; 1348 } 1349 1350 static bool ignore_undef_symbol(Elf_Half emachine, const char *name) 1351 { 1352 /* 1353 * On x86, PIC code and Clang non-PIC code may have call foo@PLT. GNU as 1354 * before 2.37 produces an unreferenced _GLOBAL_OFFSET_TABLE_ on x86-64. 1355 * i386 has a similar problem but may not deserve a fix. 1356 * 1357 * If we ever have to ignore many symbols, consider refactoring the code to 1358 * only warn if referenced by a relocation. 1359 */ 1360 if (emachine == EM_386 || emachine == EM_X86_64) 1361 return !strcmp(name, "_GLOBAL_OFFSET_TABLE_"); 1362 return false; 1363 } 1364 1365 /* Change all symbols so that st_value encodes the pointer directly. */ 1366 static int simplify_symbols(struct module *mod, const struct load_info *info) 1367 { 1368 Elf_Shdr *symsec = &info->sechdrs[info->index.sym]; 1369 Elf_Sym *sym = (void *)symsec->sh_addr; 1370 unsigned long secbase; 1371 unsigned int i; 1372 int ret = 0; 1373 const struct kernel_symbol *ksym; 1374 1375 for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) { 1376 const char *name = info->strtab + sym[i].st_name; 1377 1378 switch (sym[i].st_shndx) { 1379 case SHN_COMMON: 1380 /* Ignore common symbols */ 1381 if (!strncmp(name, "__gnu_lto", 9)) 1382 break; 1383 1384 /* 1385 * We compiled with -fno-common. These are not 1386 * supposed to happen. 1387 */ 1388 pr_debug("Common symbol: %s\n", name); 1389 pr_warn("%s: please compile with -fno-common\n", 1390 mod->name); 1391 ret = -ENOEXEC; 1392 break; 1393 1394 case SHN_ABS: 1395 /* Don't need to do anything */ 1396 pr_debug("Absolute symbol: 0x%08lx %s\n", 1397 (long)sym[i].st_value, name); 1398 break; 1399 1400 case SHN_LIVEPATCH: 1401 /* Livepatch symbols are resolved by livepatch */ 1402 break; 1403 1404 case SHN_UNDEF: 1405 ksym = resolve_symbol_wait(mod, info, name); 1406 /* Ok if resolved. */ 1407 if (ksym && !IS_ERR(ksym)) { 1408 sym[i].st_value = kernel_symbol_value(ksym); 1409 break; 1410 } 1411 1412 /* Ok if weak or ignored. */ 1413 if (!ksym && 1414 (ELF_ST_BIND(sym[i].st_info) == STB_WEAK || 1415 ignore_undef_symbol(info->hdr->e_machine, name))) 1416 break; 1417 1418 ret = PTR_ERR(ksym) ?: -ENOENT; 1419 pr_warn("%s: Unknown symbol %s (err %d)\n", 1420 mod->name, name, ret); 1421 break; 1422 1423 default: 1424 /* Divert to percpu allocation if a percpu var. */ 1425 if (sym[i].st_shndx == info->index.pcpu) 1426 secbase = (unsigned long)mod_percpu(mod); 1427 else 1428 secbase = info->sechdrs[sym[i].st_shndx].sh_addr; 1429 sym[i].st_value += secbase; 1430 break; 1431 } 1432 } 1433 1434 return ret; 1435 } 1436 1437 static int apply_relocations(struct module *mod, const struct load_info *info) 1438 { 1439 unsigned int i; 1440 int err = 0; 1441 1442 /* Now do relocations. */ 1443 for (i = 1; i < info->hdr->e_shnum; i++) { 1444 unsigned int infosec = info->sechdrs[i].sh_info; 1445 1446 /* Not a valid relocation section? */ 1447 if (infosec >= info->hdr->e_shnum) 1448 continue; 1449 1450 /* Don't bother with non-allocated sections */ 1451 if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC)) 1452 continue; 1453 1454 if (info->sechdrs[i].sh_flags & SHF_RELA_LIVEPATCH) 1455 err = klp_apply_section_relocs(mod, info->sechdrs, 1456 info->secstrings, 1457 info->strtab, 1458 info->index.sym, i, 1459 NULL); 1460 else if (info->sechdrs[i].sh_type == SHT_REL) 1461 err = apply_relocate(info->sechdrs, info->strtab, 1462 info->index.sym, i, mod); 1463 else if (info->sechdrs[i].sh_type == SHT_RELA) 1464 err = apply_relocate_add(info->sechdrs, info->strtab, 1465 info->index.sym, i, mod); 1466 if (err < 0) 1467 break; 1468 } 1469 return err; 1470 } 1471 1472 /* Additional bytes needed by arch in front of individual sections */ 1473 unsigned int __weak arch_mod_section_prepend(struct module *mod, 1474 unsigned int section) 1475 { 1476 /* default implementation just returns zero */ 1477 return 0; 1478 } 1479 1480 long module_get_offset_and_type(struct module *mod, enum mod_mem_type type, 1481 Elf_Shdr *sechdr, unsigned int section) 1482 { 1483 long offset; 1484 long mask = ((unsigned long)(type) & SH_ENTSIZE_TYPE_MASK) << SH_ENTSIZE_TYPE_SHIFT; 1485 1486 mod->mem[type].size += arch_mod_section_prepend(mod, section); 1487 offset = ALIGN(mod->mem[type].size, sechdr->sh_addralign ?: 1); 1488 mod->mem[type].size = offset + sechdr->sh_size; 1489 1490 WARN_ON_ONCE(offset & mask); 1491 return offset | mask; 1492 } 1493 1494 static bool module_init_layout_section(const char *sname) 1495 { 1496 #ifndef CONFIG_MODULE_UNLOAD 1497 if (module_exit_section(sname)) 1498 return true; 1499 #endif 1500 return module_init_section(sname); 1501 } 1502 1503 static void __layout_sections(struct module *mod, struct load_info *info, bool is_init) 1504 { 1505 unsigned int m, i; 1506 1507 static const unsigned long masks[][2] = { 1508 /* 1509 * NOTE: all executable code must be the first section 1510 * in this array; otherwise modify the text_size 1511 * finder in the two loops below 1512 */ 1513 { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL }, 1514 { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL }, 1515 { SHF_RO_AFTER_INIT | SHF_ALLOC, ARCH_SHF_SMALL }, 1516 { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL }, 1517 { ARCH_SHF_SMALL | SHF_ALLOC, 0 } 1518 }; 1519 static const int core_m_to_mem_type[] = { 1520 MOD_TEXT, 1521 MOD_RODATA, 1522 MOD_RO_AFTER_INIT, 1523 MOD_DATA, 1524 MOD_INVALID, /* This is needed to match the masks array */ 1525 }; 1526 static const int init_m_to_mem_type[] = { 1527 MOD_INIT_TEXT, 1528 MOD_INIT_RODATA, 1529 MOD_INVALID, 1530 MOD_INIT_DATA, 1531 MOD_INVALID, /* This is needed to match the masks array */ 1532 }; 1533 1534 for (m = 0; m < ARRAY_SIZE(masks); ++m) { 1535 enum mod_mem_type type = is_init ? init_m_to_mem_type[m] : core_m_to_mem_type[m]; 1536 1537 for (i = 0; i < info->hdr->e_shnum; ++i) { 1538 Elf_Shdr *s = &info->sechdrs[i]; 1539 const char *sname = info->secstrings + s->sh_name; 1540 1541 if ((s->sh_flags & masks[m][0]) != masks[m][0] 1542 || (s->sh_flags & masks[m][1]) 1543 || s->sh_entsize != ~0UL 1544 || is_init != module_init_layout_section(sname)) 1545 continue; 1546 1547 if (WARN_ON_ONCE(type == MOD_INVALID)) 1548 continue; 1549 1550 s->sh_entsize = module_get_offset_and_type(mod, type, s, i); 1551 pr_debug("\t%s\n", sname); 1552 } 1553 } 1554 } 1555 1556 /* 1557 * Lay out the SHF_ALLOC sections in a way not dissimilar to how ld 1558 * might -- code, read-only data, read-write data, small data. Tally 1559 * sizes, and place the offsets into sh_entsize fields: high bit means it 1560 * belongs in init. 1561 */ 1562 static void layout_sections(struct module *mod, struct load_info *info) 1563 { 1564 unsigned int i; 1565 1566 for (i = 0; i < info->hdr->e_shnum; i++) 1567 info->sechdrs[i].sh_entsize = ~0UL; 1568 1569 pr_debug("Core section allocation order for %s:\n", mod->name); 1570 __layout_sections(mod, info, false); 1571 1572 pr_debug("Init section allocation order for %s:\n", mod->name); 1573 __layout_sections(mod, info, true); 1574 } 1575 1576 static void module_license_taint_check(struct module *mod, const char *license) 1577 { 1578 if (!license) 1579 license = "unspecified"; 1580 1581 if (!license_is_gpl_compatible(license)) { 1582 if (!test_taint(TAINT_PROPRIETARY_MODULE)) 1583 pr_warn("%s: module license '%s' taints kernel.\n", 1584 mod->name, license); 1585 add_taint_module(mod, TAINT_PROPRIETARY_MODULE, 1586 LOCKDEP_NOW_UNRELIABLE); 1587 } 1588 } 1589 1590 static void setup_modinfo(struct module *mod, struct load_info *info) 1591 { 1592 struct module_attribute *attr; 1593 int i; 1594 1595 for (i = 0; (attr = modinfo_attrs[i]); i++) { 1596 if (attr->setup) 1597 attr->setup(mod, get_modinfo(info, attr->attr.name)); 1598 } 1599 } 1600 1601 static void free_modinfo(struct module *mod) 1602 { 1603 struct module_attribute *attr; 1604 int i; 1605 1606 for (i = 0; (attr = modinfo_attrs[i]); i++) { 1607 if (attr->free) 1608 attr->free(mod); 1609 } 1610 } 1611 1612 void * __weak module_alloc(unsigned long size) 1613 { 1614 return __vmalloc_node_range(size, 1, VMALLOC_START, VMALLOC_END, 1615 GFP_KERNEL, PAGE_KERNEL_EXEC, VM_FLUSH_RESET_PERMS, 1616 NUMA_NO_NODE, __builtin_return_address(0)); 1617 } 1618 1619 bool __weak module_init_section(const char *name) 1620 { 1621 return strstarts(name, ".init"); 1622 } 1623 1624 bool __weak module_exit_section(const char *name) 1625 { 1626 return strstarts(name, ".exit"); 1627 } 1628 1629 static int validate_section_offset(struct load_info *info, Elf_Shdr *shdr) 1630 { 1631 #if defined(CONFIG_64BIT) 1632 unsigned long long secend; 1633 #else 1634 unsigned long secend; 1635 #endif 1636 1637 /* 1638 * Check for both overflow and offset/size being 1639 * too large. 1640 */ 1641 secend = shdr->sh_offset + shdr->sh_size; 1642 if (secend < shdr->sh_offset || secend > info->len) 1643 return -ENOEXEC; 1644 1645 return 0; 1646 } 1647 1648 /* 1649 * Check userspace passed ELF module against our expectations, and cache 1650 * useful variables for further processing as we go. 1651 * 1652 * This does basic validity checks against section offsets and sizes, the 1653 * section name string table, and the indices used for it (sh_name). 1654 * 1655 * As a last step, since we're already checking the ELF sections we cache 1656 * useful variables which will be used later for our convenience: 1657 * 1658 * o pointers to section headers 1659 * o cache the modinfo symbol section 1660 * o cache the string symbol section 1661 * o cache the module section 1662 * 1663 * As a last step we set info->mod to the temporary copy of the module in 1664 * info->hdr. The final one will be allocated in move_module(). Any 1665 * modifications we make to our copy of the module will be carried over 1666 * to the final minted module. 1667 */ 1668 static int elf_validity_cache_copy(struct load_info *info, int flags) 1669 { 1670 unsigned int i; 1671 Elf_Shdr *shdr, *strhdr; 1672 int err; 1673 unsigned int num_mod_secs = 0, mod_idx; 1674 unsigned int num_info_secs = 0, info_idx; 1675 unsigned int num_sym_secs = 0, sym_idx; 1676 1677 if (info->len < sizeof(*(info->hdr))) { 1678 pr_err("Invalid ELF header len %lu\n", info->len); 1679 goto no_exec; 1680 } 1681 1682 if (memcmp(info->hdr->e_ident, ELFMAG, SELFMAG) != 0) { 1683 pr_err("Invalid ELF header magic: != %s\n", ELFMAG); 1684 goto no_exec; 1685 } 1686 if (info->hdr->e_type != ET_REL) { 1687 pr_err("Invalid ELF header type: %u != %u\n", 1688 info->hdr->e_type, ET_REL); 1689 goto no_exec; 1690 } 1691 if (!elf_check_arch(info->hdr)) { 1692 pr_err("Invalid architecture in ELF header: %u\n", 1693 info->hdr->e_machine); 1694 goto no_exec; 1695 } 1696 if (!module_elf_check_arch(info->hdr)) { 1697 pr_err("Invalid module architecture in ELF header: %u\n", 1698 info->hdr->e_machine); 1699 goto no_exec; 1700 } 1701 if (info->hdr->e_shentsize != sizeof(Elf_Shdr)) { 1702 pr_err("Invalid ELF section header size\n"); 1703 goto no_exec; 1704 } 1705 1706 /* 1707 * e_shnum is 16 bits, and sizeof(Elf_Shdr) is 1708 * known and small. So e_shnum * sizeof(Elf_Shdr) 1709 * will not overflow unsigned long on any platform. 1710 */ 1711 if (info->hdr->e_shoff >= info->len 1712 || (info->hdr->e_shnum * sizeof(Elf_Shdr) > 1713 info->len - info->hdr->e_shoff)) { 1714 pr_err("Invalid ELF section header overflow\n"); 1715 goto no_exec; 1716 } 1717 1718 info->sechdrs = (void *)info->hdr + info->hdr->e_shoff; 1719 1720 /* 1721 * Verify if the section name table index is valid. 1722 */ 1723 if (info->hdr->e_shstrndx == SHN_UNDEF 1724 || info->hdr->e_shstrndx >= info->hdr->e_shnum) { 1725 pr_err("Invalid ELF section name index: %d || e_shstrndx (%d) >= e_shnum (%d)\n", 1726 info->hdr->e_shstrndx, info->hdr->e_shstrndx, 1727 info->hdr->e_shnum); 1728 goto no_exec; 1729 } 1730 1731 strhdr = &info->sechdrs[info->hdr->e_shstrndx]; 1732 err = validate_section_offset(info, strhdr); 1733 if (err < 0) { 1734 pr_err("Invalid ELF section hdr(type %u)\n", strhdr->sh_type); 1735 return err; 1736 } 1737 1738 /* 1739 * The section name table must be NUL-terminated, as required 1740 * by the spec. This makes strcmp and pr_* calls that access 1741 * strings in the section safe. 1742 */ 1743 info->secstrings = (void *)info->hdr + strhdr->sh_offset; 1744 if (strhdr->sh_size == 0) { 1745 pr_err("empty section name table\n"); 1746 goto no_exec; 1747 } 1748 if (info->secstrings[strhdr->sh_size - 1] != '\0') { 1749 pr_err("ELF Spec violation: section name table isn't null terminated\n"); 1750 goto no_exec; 1751 } 1752 1753 /* 1754 * The code assumes that section 0 has a length of zero and 1755 * an addr of zero, so check for it. 1756 */ 1757 if (info->sechdrs[0].sh_type != SHT_NULL 1758 || info->sechdrs[0].sh_size != 0 1759 || info->sechdrs[0].sh_addr != 0) { 1760 pr_err("ELF Spec violation: section 0 type(%d)!=SH_NULL or non-zero len or addr\n", 1761 info->sechdrs[0].sh_type); 1762 goto no_exec; 1763 } 1764 1765 for (i = 1; i < info->hdr->e_shnum; i++) { 1766 shdr = &info->sechdrs[i]; 1767 switch (shdr->sh_type) { 1768 case SHT_NULL: 1769 case SHT_NOBITS: 1770 continue; 1771 case SHT_SYMTAB: 1772 if (shdr->sh_link == SHN_UNDEF 1773 || shdr->sh_link >= info->hdr->e_shnum) { 1774 pr_err("Invalid ELF sh_link!=SHN_UNDEF(%d) or (sh_link(%d) >= hdr->e_shnum(%d)\n", 1775 shdr->sh_link, shdr->sh_link, 1776 info->hdr->e_shnum); 1777 goto no_exec; 1778 } 1779 num_sym_secs++; 1780 sym_idx = i; 1781 fallthrough; 1782 default: 1783 err = validate_section_offset(info, shdr); 1784 if (err < 0) { 1785 pr_err("Invalid ELF section in module (section %u type %u)\n", 1786 i, shdr->sh_type); 1787 return err; 1788 } 1789 if (strcmp(info->secstrings + shdr->sh_name, 1790 ".gnu.linkonce.this_module") == 0) { 1791 num_mod_secs++; 1792 mod_idx = i; 1793 } else if (strcmp(info->secstrings + shdr->sh_name, 1794 ".modinfo") == 0) { 1795 num_info_secs++; 1796 info_idx = i; 1797 } 1798 1799 if (shdr->sh_flags & SHF_ALLOC) { 1800 if (shdr->sh_name >= strhdr->sh_size) { 1801 pr_err("Invalid ELF section name in module (section %u type %u)\n", 1802 i, shdr->sh_type); 1803 return -ENOEXEC; 1804 } 1805 } 1806 break; 1807 } 1808 } 1809 1810 if (num_info_secs > 1) { 1811 pr_err("Only one .modinfo section must exist.\n"); 1812 goto no_exec; 1813 } else if (num_info_secs == 1) { 1814 /* Try to find a name early so we can log errors with a module name */ 1815 info->index.info = info_idx; 1816 info->name = get_modinfo(info, "name"); 1817 } 1818 1819 if (num_sym_secs != 1) { 1820 pr_warn("%s: module has no symbols (stripped?)\n", 1821 info->name ?: "(missing .modinfo section or name field)"); 1822 goto no_exec; 1823 } 1824 1825 /* Sets internal symbols and strings. */ 1826 info->index.sym = sym_idx; 1827 shdr = &info->sechdrs[sym_idx]; 1828 info->index.str = shdr->sh_link; 1829 info->strtab = (char *)info->hdr + info->sechdrs[info->index.str].sh_offset; 1830 1831 /* 1832 * The ".gnu.linkonce.this_module" ELF section is special. It is 1833 * what modpost uses to refer to __this_module and let's use rely 1834 * on THIS_MODULE to point to &__this_module properly. The kernel's 1835 * modpost declares it on each modules's *.mod.c file. If the struct 1836 * module of the kernel changes a full kernel rebuild is required. 1837 * 1838 * We have a few expectaions for this special section, the following 1839 * code validates all this for us: 1840 * 1841 * o Only one section must exist 1842 * o We expect the kernel to always have to allocate it: SHF_ALLOC 1843 * o The section size must match the kernel's run time's struct module 1844 * size 1845 */ 1846 if (num_mod_secs != 1) { 1847 pr_err("module %s: Only one .gnu.linkonce.this_module section must exist.\n", 1848 info->name ?: "(missing .modinfo section or name field)"); 1849 goto no_exec; 1850 } 1851 1852 shdr = &info->sechdrs[mod_idx]; 1853 1854 /* 1855 * This is already implied on the switch above, however let's be 1856 * pedantic about it. 1857 */ 1858 if (shdr->sh_type == SHT_NOBITS) { 1859 pr_err("module %s: .gnu.linkonce.this_module section must have a size set\n", 1860 info->name ?: "(missing .modinfo section or name field)"); 1861 goto no_exec; 1862 } 1863 1864 if (!(shdr->sh_flags & SHF_ALLOC)) { 1865 pr_err("module %s: .gnu.linkonce.this_module must occupy memory during process execution\n", 1866 info->name ?: "(missing .modinfo section or name field)"); 1867 goto no_exec; 1868 } 1869 1870 if (shdr->sh_size != sizeof(struct module)) { 1871 pr_err("module %s: .gnu.linkonce.this_module section size must match the kernel's built struct module size at run time\n", 1872 info->name ?: "(missing .modinfo section or name field)"); 1873 goto no_exec; 1874 } 1875 1876 info->index.mod = mod_idx; 1877 1878 /* This is temporary: point mod into copy of data. */ 1879 info->mod = (void *)info->hdr + shdr->sh_offset; 1880 1881 /* 1882 * If we didn't load the .modinfo 'name' field earlier, fall back to 1883 * on-disk struct mod 'name' field. 1884 */ 1885 if (!info->name) 1886 info->name = info->mod->name; 1887 1888 if (flags & MODULE_INIT_IGNORE_MODVERSIONS) 1889 info->index.vers = 0; /* Pretend no __versions section! */ 1890 else 1891 info->index.vers = find_sec(info, "__versions"); 1892 1893 info->index.pcpu = find_pcpusec(info); 1894 1895 return 0; 1896 1897 no_exec: 1898 return -ENOEXEC; 1899 } 1900 1901 #define COPY_CHUNK_SIZE (16*PAGE_SIZE) 1902 1903 static int copy_chunked_from_user(void *dst, const void __user *usrc, unsigned long len) 1904 { 1905 do { 1906 unsigned long n = min(len, COPY_CHUNK_SIZE); 1907 1908 if (copy_from_user(dst, usrc, n) != 0) 1909 return -EFAULT; 1910 cond_resched(); 1911 dst += n; 1912 usrc += n; 1913 len -= n; 1914 } while (len); 1915 return 0; 1916 } 1917 1918 static int check_modinfo_livepatch(struct module *mod, struct load_info *info) 1919 { 1920 if (!get_modinfo(info, "livepatch")) 1921 /* Nothing more to do */ 1922 return 0; 1923 1924 if (set_livepatch_module(mod)) 1925 return 0; 1926 1927 pr_err("%s: module is marked as livepatch module, but livepatch support is disabled", 1928 mod->name); 1929 return -ENOEXEC; 1930 } 1931 1932 static void check_modinfo_retpoline(struct module *mod, struct load_info *info) 1933 { 1934 if (retpoline_module_ok(get_modinfo(info, "retpoline"))) 1935 return; 1936 1937 pr_warn("%s: loading module not compiled with retpoline compiler.\n", 1938 mod->name); 1939 } 1940 1941 /* Sets info->hdr and info->len. */ 1942 static int copy_module_from_user(const void __user *umod, unsigned long len, 1943 struct load_info *info) 1944 { 1945 int err; 1946 1947 info->len = len; 1948 if (info->len < sizeof(*(info->hdr))) 1949 return -ENOEXEC; 1950 1951 err = security_kernel_load_data(LOADING_MODULE, true); 1952 if (err) 1953 return err; 1954 1955 /* Suck in entire file: we'll want most of it. */ 1956 info->hdr = __vmalloc(info->len, GFP_KERNEL | __GFP_NOWARN); 1957 if (!info->hdr) 1958 return -ENOMEM; 1959 1960 if (copy_chunked_from_user(info->hdr, umod, info->len) != 0) { 1961 err = -EFAULT; 1962 goto out; 1963 } 1964 1965 err = security_kernel_post_load_data((char *)info->hdr, info->len, 1966 LOADING_MODULE, "init_module"); 1967 out: 1968 if (err) 1969 vfree(info->hdr); 1970 1971 return err; 1972 } 1973 1974 static void free_copy(struct load_info *info, int flags) 1975 { 1976 if (flags & MODULE_INIT_COMPRESSED_FILE) 1977 module_decompress_cleanup(info); 1978 else 1979 vfree(info->hdr); 1980 } 1981 1982 static int rewrite_section_headers(struct load_info *info, int flags) 1983 { 1984 unsigned int i; 1985 1986 /* This should always be true, but let's be sure. */ 1987 info->sechdrs[0].sh_addr = 0; 1988 1989 for (i = 1; i < info->hdr->e_shnum; i++) { 1990 Elf_Shdr *shdr = &info->sechdrs[i]; 1991 1992 /* 1993 * Mark all sections sh_addr with their address in the 1994 * temporary image. 1995 */ 1996 shdr->sh_addr = (size_t)info->hdr + shdr->sh_offset; 1997 1998 } 1999 2000 /* Track but don't keep modinfo and version sections. */ 2001 info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC; 2002 info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC; 2003 2004 return 0; 2005 } 2006 2007 /* 2008 * These calls taint the kernel depending certain module circumstances */ 2009 static void module_augment_kernel_taints(struct module *mod, struct load_info *info) 2010 { 2011 int prev_taint = test_taint(TAINT_PROPRIETARY_MODULE); 2012 2013 if (!get_modinfo(info, "intree")) { 2014 if (!test_taint(TAINT_OOT_MODULE)) 2015 pr_warn("%s: loading out-of-tree module taints kernel.\n", 2016 mod->name); 2017 add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK); 2018 } 2019 2020 check_modinfo_retpoline(mod, info); 2021 2022 if (get_modinfo(info, "staging")) { 2023 add_taint_module(mod, TAINT_CRAP, LOCKDEP_STILL_OK); 2024 pr_warn("%s: module is from the staging directory, the quality " 2025 "is unknown, you have been warned.\n", mod->name); 2026 } 2027 2028 if (is_livepatch_module(mod)) { 2029 add_taint_module(mod, TAINT_LIVEPATCH, LOCKDEP_STILL_OK); 2030 pr_notice_once("%s: tainting kernel with TAINT_LIVEPATCH\n", 2031 mod->name); 2032 } 2033 2034 module_license_taint_check(mod, get_modinfo(info, "license")); 2035 2036 if (get_modinfo(info, "test")) { 2037 if (!test_taint(TAINT_TEST)) 2038 pr_warn("%s: loading test module taints kernel.\n", 2039 mod->name); 2040 add_taint_module(mod, TAINT_TEST, LOCKDEP_STILL_OK); 2041 } 2042 #ifdef CONFIG_MODULE_SIG 2043 mod->sig_ok = info->sig_ok; 2044 if (!mod->sig_ok) { 2045 pr_notice_once("%s: module verification failed: signature " 2046 "and/or required key missing - tainting " 2047 "kernel\n", mod->name); 2048 add_taint_module(mod, TAINT_UNSIGNED_MODULE, LOCKDEP_STILL_OK); 2049 } 2050 #endif 2051 2052 /* 2053 * ndiswrapper is under GPL by itself, but loads proprietary modules. 2054 * Don't use add_taint_module(), as it would prevent ndiswrapper from 2055 * using GPL-only symbols it needs. 2056 */ 2057 if (strcmp(mod->name, "ndiswrapper") == 0) 2058 add_taint(TAINT_PROPRIETARY_MODULE, LOCKDEP_NOW_UNRELIABLE); 2059 2060 /* driverloader was caught wrongly pretending to be under GPL */ 2061 if (strcmp(mod->name, "driverloader") == 0) 2062 add_taint_module(mod, TAINT_PROPRIETARY_MODULE, 2063 LOCKDEP_NOW_UNRELIABLE); 2064 2065 /* lve claims to be GPL but upstream won't provide source */ 2066 if (strcmp(mod->name, "lve") == 0) 2067 add_taint_module(mod, TAINT_PROPRIETARY_MODULE, 2068 LOCKDEP_NOW_UNRELIABLE); 2069 2070 if (!prev_taint && test_taint(TAINT_PROPRIETARY_MODULE)) 2071 pr_warn("%s: module license taints kernel.\n", mod->name); 2072 2073 } 2074 2075 static int check_modinfo(struct module *mod, struct load_info *info, int flags) 2076 { 2077 const char *modmagic = get_modinfo(info, "vermagic"); 2078 int err; 2079 2080 if (flags & MODULE_INIT_IGNORE_VERMAGIC) 2081 modmagic = NULL; 2082 2083 /* This is allowed: modprobe --force will invalidate it. */ 2084 if (!modmagic) { 2085 err = try_to_force_load(mod, "bad vermagic"); 2086 if (err) 2087 return err; 2088 } else if (!same_magic(modmagic, vermagic, info->index.vers)) { 2089 pr_err("%s: version magic '%s' should be '%s'\n", 2090 info->name, modmagic, vermagic); 2091 return -ENOEXEC; 2092 } 2093 2094 err = check_modinfo_livepatch(mod, info); 2095 if (err) 2096 return err; 2097 2098 return 0; 2099 } 2100 2101 static int find_module_sections(struct module *mod, struct load_info *info) 2102 { 2103 mod->kp = section_objs(info, "__param", 2104 sizeof(*mod->kp), &mod->num_kp); 2105 mod->syms = section_objs(info, "__ksymtab", 2106 sizeof(*mod->syms), &mod->num_syms); 2107 mod->crcs = section_addr(info, "__kcrctab"); 2108 mod->gpl_syms = section_objs(info, "__ksymtab_gpl", 2109 sizeof(*mod->gpl_syms), 2110 &mod->num_gpl_syms); 2111 mod->gpl_crcs = section_addr(info, "__kcrctab_gpl"); 2112 2113 #ifdef CONFIG_CONSTRUCTORS 2114 mod->ctors = section_objs(info, ".ctors", 2115 sizeof(*mod->ctors), &mod->num_ctors); 2116 if (!mod->ctors) 2117 mod->ctors = section_objs(info, ".init_array", 2118 sizeof(*mod->ctors), &mod->num_ctors); 2119 else if (find_sec(info, ".init_array")) { 2120 /* 2121 * This shouldn't happen with same compiler and binutils 2122 * building all parts of the module. 2123 */ 2124 pr_warn("%s: has both .ctors and .init_array.\n", 2125 mod->name); 2126 return -EINVAL; 2127 } 2128 #endif 2129 2130 mod->noinstr_text_start = section_objs(info, ".noinstr.text", 1, 2131 &mod->noinstr_text_size); 2132 2133 #ifdef CONFIG_TRACEPOINTS 2134 mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs", 2135 sizeof(*mod->tracepoints_ptrs), 2136 &mod->num_tracepoints); 2137 #endif 2138 #ifdef CONFIG_TREE_SRCU 2139 mod->srcu_struct_ptrs = section_objs(info, "___srcu_struct_ptrs", 2140 sizeof(*mod->srcu_struct_ptrs), 2141 &mod->num_srcu_structs); 2142 #endif 2143 #ifdef CONFIG_BPF_EVENTS 2144 mod->bpf_raw_events = section_objs(info, "__bpf_raw_tp_map", 2145 sizeof(*mod->bpf_raw_events), 2146 &mod->num_bpf_raw_events); 2147 #endif 2148 #ifdef CONFIG_DEBUG_INFO_BTF_MODULES 2149 mod->btf_data = any_section_objs(info, ".BTF", 1, &mod->btf_data_size); 2150 #endif 2151 #ifdef CONFIG_JUMP_LABEL 2152 mod->jump_entries = section_objs(info, "__jump_table", 2153 sizeof(*mod->jump_entries), 2154 &mod->num_jump_entries); 2155 #endif 2156 #ifdef CONFIG_EVENT_TRACING 2157 mod->trace_events = section_objs(info, "_ftrace_events", 2158 sizeof(*mod->trace_events), 2159 &mod->num_trace_events); 2160 mod->trace_evals = section_objs(info, "_ftrace_eval_map", 2161 sizeof(*mod->trace_evals), 2162 &mod->num_trace_evals); 2163 #endif 2164 #ifdef CONFIG_TRACING 2165 mod->trace_bprintk_fmt_start = section_objs(info, "__trace_printk_fmt", 2166 sizeof(*mod->trace_bprintk_fmt_start), 2167 &mod->num_trace_bprintk_fmt); 2168 #endif 2169 #ifdef CONFIG_FTRACE_MCOUNT_RECORD 2170 /* sechdrs[0].sh_size is always zero */ 2171 mod->ftrace_callsites = section_objs(info, FTRACE_CALLSITE_SECTION, 2172 sizeof(*mod->ftrace_callsites), 2173 &mod->num_ftrace_callsites); 2174 #endif 2175 #ifdef CONFIG_FUNCTION_ERROR_INJECTION 2176 mod->ei_funcs = section_objs(info, "_error_injection_whitelist", 2177 sizeof(*mod->ei_funcs), 2178 &mod->num_ei_funcs); 2179 #endif 2180 #ifdef CONFIG_KPROBES 2181 mod->kprobes_text_start = section_objs(info, ".kprobes.text", 1, 2182 &mod->kprobes_text_size); 2183 mod->kprobe_blacklist = section_objs(info, "_kprobe_blacklist", 2184 sizeof(unsigned long), 2185 &mod->num_kprobe_blacklist); 2186 #endif 2187 #ifdef CONFIG_PRINTK_INDEX 2188 mod->printk_index_start = section_objs(info, ".printk_index", 2189 sizeof(*mod->printk_index_start), 2190 &mod->printk_index_size); 2191 #endif 2192 #ifdef CONFIG_HAVE_STATIC_CALL_INLINE 2193 mod->static_call_sites = section_objs(info, ".static_call_sites", 2194 sizeof(*mod->static_call_sites), 2195 &mod->num_static_call_sites); 2196 #endif 2197 #if IS_ENABLED(CONFIG_KUNIT) 2198 mod->kunit_suites = section_objs(info, ".kunit_test_suites", 2199 sizeof(*mod->kunit_suites), 2200 &mod->num_kunit_suites); 2201 #endif 2202 2203 mod->extable = section_objs(info, "__ex_table", 2204 sizeof(*mod->extable), &mod->num_exentries); 2205 2206 if (section_addr(info, "__obsparm")) 2207 pr_warn("%s: Ignoring obsolete parameters\n", mod->name); 2208 2209 #ifdef CONFIG_DYNAMIC_DEBUG_CORE 2210 mod->dyndbg_info.descs = section_objs(info, "__dyndbg", 2211 sizeof(*mod->dyndbg_info.descs), 2212 &mod->dyndbg_info.num_descs); 2213 mod->dyndbg_info.classes = section_objs(info, "__dyndbg_classes", 2214 sizeof(*mod->dyndbg_info.classes), 2215 &mod->dyndbg_info.num_classes); 2216 #endif 2217 2218 return 0; 2219 } 2220 2221 static int move_module(struct module *mod, struct load_info *info) 2222 { 2223 int i; 2224 void *ptr; 2225 enum mod_mem_type t = 0; 2226 int ret = -ENOMEM; 2227 2228 for_each_mod_mem_type(type) { 2229 if (!mod->mem[type].size) { 2230 mod->mem[type].base = NULL; 2231 continue; 2232 } 2233 mod->mem[type].size = PAGE_ALIGN(mod->mem[type].size); 2234 ptr = module_memory_alloc(mod->mem[type].size, type); 2235 /* 2236 * The pointer to these blocks of memory are stored on the module 2237 * structure and we keep that around so long as the module is 2238 * around. We only free that memory when we unload the module. 2239 * Just mark them as not being a leak then. The .init* ELF 2240 * sections *do* get freed after boot so we *could* treat them 2241 * slightly differently with kmemleak_ignore() and only grey 2242 * them out as they work as typical memory allocations which 2243 * *do* eventually get freed, but let's just keep things simple 2244 * and avoid *any* false positives. 2245 */ 2246 kmemleak_not_leak(ptr); 2247 if (!ptr) { 2248 t = type; 2249 goto out_enomem; 2250 } 2251 memset(ptr, 0, mod->mem[type].size); 2252 mod->mem[type].base = ptr; 2253 } 2254 2255 /* Transfer each section which specifies SHF_ALLOC */ 2256 pr_debug("Final section addresses for %s:\n", mod->name); 2257 for (i = 0; i < info->hdr->e_shnum; i++) { 2258 void *dest; 2259 Elf_Shdr *shdr = &info->sechdrs[i]; 2260 enum mod_mem_type type = shdr->sh_entsize >> SH_ENTSIZE_TYPE_SHIFT; 2261 2262 if (!(shdr->sh_flags & SHF_ALLOC)) 2263 continue; 2264 2265 dest = mod->mem[type].base + (shdr->sh_entsize & SH_ENTSIZE_OFFSET_MASK); 2266 2267 if (shdr->sh_type != SHT_NOBITS) { 2268 /* 2269 * Our ELF checker already validated this, but let's 2270 * be pedantic and make the goal clearer. We actually 2271 * end up copying over all modifications made to the 2272 * userspace copy of the entire struct module. 2273 */ 2274 if (i == info->index.mod && 2275 (WARN_ON_ONCE(shdr->sh_size != sizeof(struct module)))) { 2276 ret = -ENOEXEC; 2277 goto out_enomem; 2278 } 2279 memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size); 2280 } 2281 /* 2282 * Update the userspace copy's ELF section address to point to 2283 * our newly allocated memory as a pure convenience so that 2284 * users of info can keep taking advantage and using the newly 2285 * minted official memory area. 2286 */ 2287 shdr->sh_addr = (unsigned long)dest; 2288 pr_debug("\t0x%lx 0x%.8lx %s\n", (long)shdr->sh_addr, 2289 (long)shdr->sh_size, info->secstrings + shdr->sh_name); 2290 } 2291 2292 return 0; 2293 out_enomem: 2294 for (t--; t >= 0; t--) 2295 module_memory_free(mod->mem[t].base, t); 2296 return ret; 2297 } 2298 2299 static int check_export_symbol_versions(struct module *mod) 2300 { 2301 #ifdef CONFIG_MODVERSIONS 2302 if ((mod->num_syms && !mod->crcs) || 2303 (mod->num_gpl_syms && !mod->gpl_crcs)) { 2304 return try_to_force_load(mod, 2305 "no versions for exported symbols"); 2306 } 2307 #endif 2308 return 0; 2309 } 2310 2311 static void flush_module_icache(const struct module *mod) 2312 { 2313 /* 2314 * Flush the instruction cache, since we've played with text. 2315 * Do it before processing of module parameters, so the module 2316 * can provide parameter accessor functions of its own. 2317 */ 2318 for_each_mod_mem_type(type) { 2319 const struct module_memory *mod_mem = &mod->mem[type]; 2320 2321 if (mod_mem->size) { 2322 flush_icache_range((unsigned long)mod_mem->base, 2323 (unsigned long)mod_mem->base + mod_mem->size); 2324 } 2325 } 2326 } 2327 2328 bool __weak module_elf_check_arch(Elf_Ehdr *hdr) 2329 { 2330 return true; 2331 } 2332 2333 int __weak module_frob_arch_sections(Elf_Ehdr *hdr, 2334 Elf_Shdr *sechdrs, 2335 char *secstrings, 2336 struct module *mod) 2337 { 2338 return 0; 2339 } 2340 2341 /* module_blacklist is a comma-separated list of module names */ 2342 static char *module_blacklist; 2343 static bool blacklisted(const char *module_name) 2344 { 2345 const char *p; 2346 size_t len; 2347 2348 if (!module_blacklist) 2349 return false; 2350 2351 for (p = module_blacklist; *p; p += len) { 2352 len = strcspn(p, ","); 2353 if (strlen(module_name) == len && !memcmp(module_name, p, len)) 2354 return true; 2355 if (p[len] == ',') 2356 len++; 2357 } 2358 return false; 2359 } 2360 core_param(module_blacklist, module_blacklist, charp, 0400); 2361 2362 static struct module *layout_and_allocate(struct load_info *info, int flags) 2363 { 2364 struct module *mod; 2365 unsigned int ndx; 2366 int err; 2367 2368 /* Allow arches to frob section contents and sizes. */ 2369 err = module_frob_arch_sections(info->hdr, info->sechdrs, 2370 info->secstrings, info->mod); 2371 if (err < 0) 2372 return ERR_PTR(err); 2373 2374 err = module_enforce_rwx_sections(info->hdr, info->sechdrs, 2375 info->secstrings, info->mod); 2376 if (err < 0) 2377 return ERR_PTR(err); 2378 2379 /* We will do a special allocation for per-cpu sections later. */ 2380 info->sechdrs[info->index.pcpu].sh_flags &= ~(unsigned long)SHF_ALLOC; 2381 2382 /* 2383 * Mark ro_after_init section with SHF_RO_AFTER_INIT so that 2384 * layout_sections() can put it in the right place. 2385 * Note: ro_after_init sections also have SHF_{WRITE,ALLOC} set. 2386 */ 2387 ndx = find_sec(info, ".data..ro_after_init"); 2388 if (ndx) 2389 info->sechdrs[ndx].sh_flags |= SHF_RO_AFTER_INIT; 2390 /* 2391 * Mark the __jump_table section as ro_after_init as well: these data 2392 * structures are never modified, with the exception of entries that 2393 * refer to code in the __init section, which are annotated as such 2394 * at module load time. 2395 */ 2396 ndx = find_sec(info, "__jump_table"); 2397 if (ndx) 2398 info->sechdrs[ndx].sh_flags |= SHF_RO_AFTER_INIT; 2399 2400 /* 2401 * Determine total sizes, and put offsets in sh_entsize. For now 2402 * this is done generically; there doesn't appear to be any 2403 * special cases for the architectures. 2404 */ 2405 layout_sections(info->mod, info); 2406 layout_symtab(info->mod, info); 2407 2408 /* Allocate and move to the final place */ 2409 err = move_module(info->mod, info); 2410 if (err) 2411 return ERR_PTR(err); 2412 2413 /* Module has been copied to its final place now: return it. */ 2414 mod = (void *)info->sechdrs[info->index.mod].sh_addr; 2415 kmemleak_load_module(mod, info); 2416 return mod; 2417 } 2418 2419 /* mod is no longer valid after this! */ 2420 static void module_deallocate(struct module *mod, struct load_info *info) 2421 { 2422 percpu_modfree(mod); 2423 module_arch_freeing_init(mod); 2424 2425 free_mod_mem(mod); 2426 } 2427 2428 int __weak module_finalize(const Elf_Ehdr *hdr, 2429 const Elf_Shdr *sechdrs, 2430 struct module *me) 2431 { 2432 return 0; 2433 } 2434 2435 static int post_relocation(struct module *mod, const struct load_info *info) 2436 { 2437 /* Sort exception table now relocations are done. */ 2438 sort_extable(mod->extable, mod->extable + mod->num_exentries); 2439 2440 /* Copy relocated percpu area over. */ 2441 percpu_modcopy(mod, (void *)info->sechdrs[info->index.pcpu].sh_addr, 2442 info->sechdrs[info->index.pcpu].sh_size); 2443 2444 /* Setup kallsyms-specific fields. */ 2445 add_kallsyms(mod, info); 2446 2447 /* Arch-specific module finalizing. */ 2448 return module_finalize(info->hdr, info->sechdrs, mod); 2449 } 2450 2451 /* Call module constructors. */ 2452 static void do_mod_ctors(struct module *mod) 2453 { 2454 #ifdef CONFIG_CONSTRUCTORS 2455 unsigned long i; 2456 2457 for (i = 0; i < mod->num_ctors; i++) 2458 mod->ctors[i](); 2459 #endif 2460 } 2461 2462 /* For freeing module_init on success, in case kallsyms traversing */ 2463 struct mod_initfree { 2464 struct llist_node node; 2465 void *init_text; 2466 void *init_data; 2467 void *init_rodata; 2468 }; 2469 2470 static void do_free_init(struct work_struct *w) 2471 { 2472 struct llist_node *pos, *n, *list; 2473 struct mod_initfree *initfree; 2474 2475 list = llist_del_all(&init_free_list); 2476 2477 synchronize_rcu(); 2478 2479 llist_for_each_safe(pos, n, list) { 2480 initfree = container_of(pos, struct mod_initfree, node); 2481 module_memfree(initfree->init_text); 2482 module_memfree(initfree->init_data); 2483 module_memfree(initfree->init_rodata); 2484 kfree(initfree); 2485 } 2486 } 2487 2488 #undef MODULE_PARAM_PREFIX 2489 #define MODULE_PARAM_PREFIX "module." 2490 /* Default value for module->async_probe_requested */ 2491 static bool async_probe; 2492 module_param(async_probe, bool, 0644); 2493 2494 /* 2495 * This is where the real work happens. 2496 * 2497 * Keep it uninlined to provide a reliable breakpoint target, e.g. for the gdb 2498 * helper command 'lx-symbols'. 2499 */ 2500 static noinline int do_init_module(struct module *mod) 2501 { 2502 int ret = 0; 2503 struct mod_initfree *freeinit; 2504 #if defined(CONFIG_MODULE_STATS) 2505 unsigned int text_size = 0, total_size = 0; 2506 2507 for_each_mod_mem_type(type) { 2508 const struct module_memory *mod_mem = &mod->mem[type]; 2509 if (mod_mem->size) { 2510 total_size += mod_mem->size; 2511 if (type == MOD_TEXT || type == MOD_INIT_TEXT) 2512 text_size += mod_mem->size; 2513 } 2514 } 2515 #endif 2516 2517 freeinit = kmalloc(sizeof(*freeinit), GFP_KERNEL); 2518 if (!freeinit) { 2519 ret = -ENOMEM; 2520 goto fail; 2521 } 2522 freeinit->init_text = mod->mem[MOD_INIT_TEXT].base; 2523 freeinit->init_data = mod->mem[MOD_INIT_DATA].base; 2524 freeinit->init_rodata = mod->mem[MOD_INIT_RODATA].base; 2525 2526 do_mod_ctors(mod); 2527 /* Start the module */ 2528 if (mod->init != NULL) 2529 ret = do_one_initcall(mod->init); 2530 if (ret < 0) { 2531 goto fail_free_freeinit; 2532 } 2533 if (ret > 0) { 2534 pr_warn("%s: '%s'->init suspiciously returned %d, it should " 2535 "follow 0/-E convention\n" 2536 "%s: loading module anyway...\n", 2537 __func__, mod->name, ret, __func__); 2538 dump_stack(); 2539 } 2540 2541 /* Now it's a first class citizen! */ 2542 mod->state = MODULE_STATE_LIVE; 2543 blocking_notifier_call_chain(&module_notify_list, 2544 MODULE_STATE_LIVE, mod); 2545 2546 /* Delay uevent until module has finished its init routine */ 2547 kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD); 2548 2549 /* 2550 * We need to finish all async code before the module init sequence 2551 * is done. This has potential to deadlock if synchronous module 2552 * loading is requested from async (which is not allowed!). 2553 * 2554 * See commit 0fdff3ec6d87 ("async, kmod: warn on synchronous 2555 * request_module() from async workers") for more details. 2556 */ 2557 if (!mod->async_probe_requested) 2558 async_synchronize_full(); 2559 2560 ftrace_free_mem(mod, mod->mem[MOD_INIT_TEXT].base, 2561 mod->mem[MOD_INIT_TEXT].base + mod->mem[MOD_INIT_TEXT].size); 2562 mutex_lock(&module_mutex); 2563 /* Drop initial reference. */ 2564 module_put(mod); 2565 trim_init_extable(mod); 2566 #ifdef CONFIG_KALLSYMS 2567 /* Switch to core kallsyms now init is done: kallsyms may be walking! */ 2568 rcu_assign_pointer(mod->kallsyms, &mod->core_kallsyms); 2569 #endif 2570 module_enable_ro(mod, true); 2571 mod_tree_remove_init(mod); 2572 module_arch_freeing_init(mod); 2573 for_class_mod_mem_type(type, init) { 2574 mod->mem[type].base = NULL; 2575 mod->mem[type].size = 0; 2576 } 2577 2578 #ifdef CONFIG_DEBUG_INFO_BTF_MODULES 2579 /* .BTF is not SHF_ALLOC and will get removed, so sanitize pointer */ 2580 mod->btf_data = NULL; 2581 #endif 2582 /* 2583 * We want to free module_init, but be aware that kallsyms may be 2584 * walking this with preempt disabled. In all the failure paths, we 2585 * call synchronize_rcu(), but we don't want to slow down the success 2586 * path. module_memfree() cannot be called in an interrupt, so do the 2587 * work and call synchronize_rcu() in a work queue. 2588 * 2589 * Note that module_alloc() on most architectures creates W+X page 2590 * mappings which won't be cleaned up until do_free_init() runs. Any 2591 * code such as mark_rodata_ro() which depends on those mappings to 2592 * be cleaned up needs to sync with the queued work - ie 2593 * rcu_barrier() 2594 */ 2595 if (llist_add(&freeinit->node, &init_free_list)) 2596 schedule_work(&init_free_wq); 2597 2598 mutex_unlock(&module_mutex); 2599 wake_up_all(&module_wq); 2600 2601 mod_stat_add_long(text_size, &total_text_size); 2602 mod_stat_add_long(total_size, &total_mod_size); 2603 2604 mod_stat_inc(&modcount); 2605 2606 return 0; 2607 2608 fail_free_freeinit: 2609 kfree(freeinit); 2610 fail: 2611 /* Try to protect us from buggy refcounters. */ 2612 mod->state = MODULE_STATE_GOING; 2613 synchronize_rcu(); 2614 module_put(mod); 2615 blocking_notifier_call_chain(&module_notify_list, 2616 MODULE_STATE_GOING, mod); 2617 klp_module_going(mod); 2618 ftrace_release_mod(mod); 2619 free_module(mod); 2620 wake_up_all(&module_wq); 2621 2622 return ret; 2623 } 2624 2625 static int may_init_module(void) 2626 { 2627 if (!capable(CAP_SYS_MODULE) || modules_disabled) 2628 return -EPERM; 2629 2630 return 0; 2631 } 2632 2633 /* Is this module of this name done loading? No locks held. */ 2634 static bool finished_loading(const char *name) 2635 { 2636 struct module *mod; 2637 bool ret; 2638 2639 /* 2640 * The module_mutex should not be a heavily contended lock; 2641 * if we get the occasional sleep here, we'll go an extra iteration 2642 * in the wait_event_interruptible(), which is harmless. 2643 */ 2644 sched_annotate_sleep(); 2645 mutex_lock(&module_mutex); 2646 mod = find_module_all(name, strlen(name), true); 2647 ret = !mod || mod->state == MODULE_STATE_LIVE 2648 || mod->state == MODULE_STATE_GOING; 2649 mutex_unlock(&module_mutex); 2650 2651 return ret; 2652 } 2653 2654 /* Must be called with module_mutex held */ 2655 static int module_patient_check_exists(const char *name, 2656 enum fail_dup_mod_reason reason) 2657 { 2658 struct module *old; 2659 int err = 0; 2660 2661 old = find_module_all(name, strlen(name), true); 2662 if (old == NULL) 2663 return 0; 2664 2665 if (old->state == MODULE_STATE_COMING || 2666 old->state == MODULE_STATE_UNFORMED) { 2667 /* Wait in case it fails to load. */ 2668 mutex_unlock(&module_mutex); 2669 err = wait_event_interruptible(module_wq, 2670 finished_loading(name)); 2671 mutex_lock(&module_mutex); 2672 if (err) 2673 return err; 2674 2675 /* The module might have gone in the meantime. */ 2676 old = find_module_all(name, strlen(name), true); 2677 } 2678 2679 if (try_add_failed_module(name, reason)) 2680 pr_warn("Could not add fail-tracking for module: %s\n", name); 2681 2682 /* 2683 * We are here only when the same module was being loaded. Do 2684 * not try to load it again right now. It prevents long delays 2685 * caused by serialized module load failures. It might happen 2686 * when more devices of the same type trigger load of 2687 * a particular module. 2688 */ 2689 if (old && old->state == MODULE_STATE_LIVE) 2690 return -EEXIST; 2691 return -EBUSY; 2692 } 2693 2694 /* 2695 * We try to place it in the list now to make sure it's unique before 2696 * we dedicate too many resources. In particular, temporary percpu 2697 * memory exhaustion. 2698 */ 2699 static int add_unformed_module(struct module *mod) 2700 { 2701 int err; 2702 2703 mod->state = MODULE_STATE_UNFORMED; 2704 2705 mutex_lock(&module_mutex); 2706 err = module_patient_check_exists(mod->name, FAIL_DUP_MOD_LOAD); 2707 if (err) 2708 goto out; 2709 2710 mod_update_bounds(mod); 2711 list_add_rcu(&mod->list, &modules); 2712 mod_tree_insert(mod); 2713 err = 0; 2714 2715 out: 2716 mutex_unlock(&module_mutex); 2717 return err; 2718 } 2719 2720 static int complete_formation(struct module *mod, struct load_info *info) 2721 { 2722 int err; 2723 2724 mutex_lock(&module_mutex); 2725 2726 /* Find duplicate symbols (must be called under lock). */ 2727 err = verify_exported_symbols(mod); 2728 if (err < 0) 2729 goto out; 2730 2731 /* These rely on module_mutex for list integrity. */ 2732 module_bug_finalize(info->hdr, info->sechdrs, mod); 2733 module_cfi_finalize(info->hdr, info->sechdrs, mod); 2734 2735 module_enable_ro(mod, false); 2736 module_enable_nx(mod); 2737 module_enable_x(mod); 2738 2739 /* 2740 * Mark state as coming so strong_try_module_get() ignores us, 2741 * but kallsyms etc. can see us. 2742 */ 2743 mod->state = MODULE_STATE_COMING; 2744 mutex_unlock(&module_mutex); 2745 2746 return 0; 2747 2748 out: 2749 mutex_unlock(&module_mutex); 2750 return err; 2751 } 2752 2753 static int prepare_coming_module(struct module *mod) 2754 { 2755 int err; 2756 2757 ftrace_module_enable(mod); 2758 err = klp_module_coming(mod); 2759 if (err) 2760 return err; 2761 2762 err = blocking_notifier_call_chain_robust(&module_notify_list, 2763 MODULE_STATE_COMING, MODULE_STATE_GOING, mod); 2764 err = notifier_to_errno(err); 2765 if (err) 2766 klp_module_going(mod); 2767 2768 return err; 2769 } 2770 2771 static int unknown_module_param_cb(char *param, char *val, const char *modname, 2772 void *arg) 2773 { 2774 struct module *mod = arg; 2775 int ret; 2776 2777 if (strcmp(param, "async_probe") == 0) { 2778 if (kstrtobool(val, &mod->async_probe_requested)) 2779 mod->async_probe_requested = true; 2780 return 0; 2781 } 2782 2783 /* Check for magic 'dyndbg' arg */ 2784 ret = ddebug_dyndbg_module_param_cb(param, val, modname); 2785 if (ret != 0) 2786 pr_warn("%s: unknown parameter '%s' ignored\n", modname, param); 2787 return 0; 2788 } 2789 2790 /* Module within temporary copy, this doesn't do any allocation */ 2791 static int early_mod_check(struct load_info *info, int flags) 2792 { 2793 int err; 2794 2795 /* 2796 * Now that we know we have the correct module name, check 2797 * if it's blacklisted. 2798 */ 2799 if (blacklisted(info->name)) { 2800 pr_err("Module %s is blacklisted\n", info->name); 2801 return -EPERM; 2802 } 2803 2804 err = rewrite_section_headers(info, flags); 2805 if (err) 2806 return err; 2807 2808 /* Check module struct version now, before we try to use module. */ 2809 if (!check_modstruct_version(info, info->mod)) 2810 return -ENOEXEC; 2811 2812 err = check_modinfo(info->mod, info, flags); 2813 if (err) 2814 return err; 2815 2816 mutex_lock(&module_mutex); 2817 err = module_patient_check_exists(info->mod->name, FAIL_DUP_MOD_BECOMING); 2818 mutex_unlock(&module_mutex); 2819 2820 return err; 2821 } 2822 2823 /* 2824 * Allocate and load the module: note that size of section 0 is always 2825 * zero, and we rely on this for optional sections. 2826 */ 2827 static int load_module(struct load_info *info, const char __user *uargs, 2828 int flags) 2829 { 2830 struct module *mod; 2831 bool module_allocated = false; 2832 long err = 0; 2833 char *after_dashes; 2834 2835 /* 2836 * Do the signature check (if any) first. All that 2837 * the signature check needs is info->len, it does 2838 * not need any of the section info. That can be 2839 * set up later. This will minimize the chances 2840 * of a corrupt module causing problems before 2841 * we even get to the signature check. 2842 * 2843 * The check will also adjust info->len by stripping 2844 * off the sig length at the end of the module, making 2845 * checks against info->len more correct. 2846 */ 2847 err = module_sig_check(info, flags); 2848 if (err) 2849 goto free_copy; 2850 2851 /* 2852 * Do basic sanity checks against the ELF header and 2853 * sections. Cache useful sections and set the 2854 * info->mod to the userspace passed struct module. 2855 */ 2856 err = elf_validity_cache_copy(info, flags); 2857 if (err) 2858 goto free_copy; 2859 2860 err = early_mod_check(info, flags); 2861 if (err) 2862 goto free_copy; 2863 2864 /* Figure out module layout, and allocate all the memory. */ 2865 mod = layout_and_allocate(info, flags); 2866 if (IS_ERR(mod)) { 2867 err = PTR_ERR(mod); 2868 goto free_copy; 2869 } 2870 2871 module_allocated = true; 2872 2873 audit_log_kern_module(mod->name); 2874 2875 /* Reserve our place in the list. */ 2876 err = add_unformed_module(mod); 2877 if (err) 2878 goto free_module; 2879 2880 /* 2881 * We are tainting your kernel if your module gets into 2882 * the modules linked list somehow. 2883 */ 2884 module_augment_kernel_taints(mod, info); 2885 2886 /* To avoid stressing percpu allocator, do this once we're unique. */ 2887 err = percpu_modalloc(mod, info); 2888 if (err) 2889 goto unlink_mod; 2890 2891 /* Now module is in final location, initialize linked lists, etc. */ 2892 err = module_unload_init(mod); 2893 if (err) 2894 goto unlink_mod; 2895 2896 init_param_lock(mod); 2897 2898 /* 2899 * Now we've got everything in the final locations, we can 2900 * find optional sections. 2901 */ 2902 err = find_module_sections(mod, info); 2903 if (err) 2904 goto free_unload; 2905 2906 err = check_export_symbol_versions(mod); 2907 if (err) 2908 goto free_unload; 2909 2910 /* Set up MODINFO_ATTR fields */ 2911 setup_modinfo(mod, info); 2912 2913 /* Fix up syms, so that st_value is a pointer to location. */ 2914 err = simplify_symbols(mod, info); 2915 if (err < 0) 2916 goto free_modinfo; 2917 2918 err = apply_relocations(mod, info); 2919 if (err < 0) 2920 goto free_modinfo; 2921 2922 err = post_relocation(mod, info); 2923 if (err < 0) 2924 goto free_modinfo; 2925 2926 flush_module_icache(mod); 2927 2928 /* Now copy in args */ 2929 mod->args = strndup_user(uargs, ~0UL >> 1); 2930 if (IS_ERR(mod->args)) { 2931 err = PTR_ERR(mod->args); 2932 goto free_arch_cleanup; 2933 } 2934 2935 init_build_id(mod, info); 2936 2937 /* Ftrace init must be called in the MODULE_STATE_UNFORMED state */ 2938 ftrace_module_init(mod); 2939 2940 /* Finally it's fully formed, ready to start executing. */ 2941 err = complete_formation(mod, info); 2942 if (err) 2943 goto ddebug_cleanup; 2944 2945 err = prepare_coming_module(mod); 2946 if (err) 2947 goto bug_cleanup; 2948 2949 mod->async_probe_requested = async_probe; 2950 2951 /* Module is ready to execute: parsing args may do that. */ 2952 after_dashes = parse_args(mod->name, mod->args, mod->kp, mod->num_kp, 2953 -32768, 32767, mod, 2954 unknown_module_param_cb); 2955 if (IS_ERR(after_dashes)) { 2956 err = PTR_ERR(after_dashes); 2957 goto coming_cleanup; 2958 } else if (after_dashes) { 2959 pr_warn("%s: parameters '%s' after `--' ignored\n", 2960 mod->name, after_dashes); 2961 } 2962 2963 /* Link in to sysfs. */ 2964 err = mod_sysfs_setup(mod, info, mod->kp, mod->num_kp); 2965 if (err < 0) 2966 goto coming_cleanup; 2967 2968 if (is_livepatch_module(mod)) { 2969 err = copy_module_elf(mod, info); 2970 if (err < 0) 2971 goto sysfs_cleanup; 2972 } 2973 2974 /* Get rid of temporary copy. */ 2975 free_copy(info, flags); 2976 2977 /* Done! */ 2978 trace_module_load(mod); 2979 2980 return do_init_module(mod); 2981 2982 sysfs_cleanup: 2983 mod_sysfs_teardown(mod); 2984 coming_cleanup: 2985 mod->state = MODULE_STATE_GOING; 2986 destroy_params(mod->kp, mod->num_kp); 2987 blocking_notifier_call_chain(&module_notify_list, 2988 MODULE_STATE_GOING, mod); 2989 klp_module_going(mod); 2990 bug_cleanup: 2991 mod->state = MODULE_STATE_GOING; 2992 /* module_bug_cleanup needs module_mutex protection */ 2993 mutex_lock(&module_mutex); 2994 module_bug_cleanup(mod); 2995 mutex_unlock(&module_mutex); 2996 2997 ddebug_cleanup: 2998 ftrace_release_mod(mod); 2999 synchronize_rcu(); 3000 kfree(mod->args); 3001 free_arch_cleanup: 3002 module_arch_cleanup(mod); 3003 free_modinfo: 3004 free_modinfo(mod); 3005 free_unload: 3006 module_unload_free(mod); 3007 unlink_mod: 3008 mutex_lock(&module_mutex); 3009 /* Unlink carefully: kallsyms could be walking list. */ 3010 list_del_rcu(&mod->list); 3011 mod_tree_remove(mod); 3012 wake_up_all(&module_wq); 3013 /* Wait for RCU-sched synchronizing before releasing mod->list. */ 3014 synchronize_rcu(); 3015 mutex_unlock(&module_mutex); 3016 free_module: 3017 mod_stat_bump_invalid(info, flags); 3018 /* Free lock-classes; relies on the preceding sync_rcu() */ 3019 for_class_mod_mem_type(type, core_data) { 3020 lockdep_free_key_range(mod->mem[type].base, 3021 mod->mem[type].size); 3022 } 3023 3024 module_deallocate(mod, info); 3025 free_copy: 3026 /* 3027 * The info->len is always set. We distinguish between 3028 * failures once the proper module was allocated and 3029 * before that. 3030 */ 3031 if (!module_allocated) 3032 mod_stat_bump_becoming(info, flags); 3033 free_copy(info, flags); 3034 return err; 3035 } 3036 3037 SYSCALL_DEFINE3(init_module, void __user *, umod, 3038 unsigned long, len, const char __user *, uargs) 3039 { 3040 int err; 3041 struct load_info info = { }; 3042 3043 err = may_init_module(); 3044 if (err) 3045 return err; 3046 3047 pr_debug("init_module: umod=%p, len=%lu, uargs=%p\n", 3048 umod, len, uargs); 3049 3050 err = copy_module_from_user(umod, len, &info); 3051 if (err) { 3052 mod_stat_inc(&failed_kreads); 3053 mod_stat_add_long(len, &invalid_kread_bytes); 3054 return err; 3055 } 3056 3057 return load_module(&info, uargs, 0); 3058 } 3059 3060 SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags) 3061 { 3062 struct load_info info = { }; 3063 void *buf = NULL; 3064 int len; 3065 int err; 3066 3067 err = may_init_module(); 3068 if (err) 3069 return err; 3070 3071 pr_debug("finit_module: fd=%d, uargs=%p, flags=%i\n", fd, uargs, flags); 3072 3073 if (flags & ~(MODULE_INIT_IGNORE_MODVERSIONS 3074 |MODULE_INIT_IGNORE_VERMAGIC 3075 |MODULE_INIT_COMPRESSED_FILE)) 3076 return -EINVAL; 3077 3078 len = kernel_read_file_from_fd(fd, 0, &buf, INT_MAX, NULL, 3079 READING_MODULE); 3080 if (len < 0) { 3081 mod_stat_inc(&failed_kreads); 3082 mod_stat_add_long(len, &invalid_kread_bytes); 3083 return len; 3084 } 3085 3086 if (flags & MODULE_INIT_COMPRESSED_FILE) { 3087 err = module_decompress(&info, buf, len); 3088 vfree(buf); /* compressed data is no longer needed */ 3089 if (err) { 3090 mod_stat_inc(&failed_decompress); 3091 mod_stat_add_long(len, &invalid_decompress_bytes); 3092 return err; 3093 } 3094 } else { 3095 info.hdr = buf; 3096 info.len = len; 3097 } 3098 3099 return load_module(&info, uargs, flags); 3100 } 3101 3102 /* Keep in sync with MODULE_FLAGS_BUF_SIZE !!! */ 3103 char *module_flags(struct module *mod, char *buf, bool show_state) 3104 { 3105 int bx = 0; 3106 3107 BUG_ON(mod->state == MODULE_STATE_UNFORMED); 3108 if (!mod->taints && !show_state) 3109 goto out; 3110 if (mod->taints || 3111 mod->state == MODULE_STATE_GOING || 3112 mod->state == MODULE_STATE_COMING) { 3113 buf[bx++] = '('; 3114 bx += module_flags_taint(mod->taints, buf + bx); 3115 /* Show a - for module-is-being-unloaded */ 3116 if (mod->state == MODULE_STATE_GOING && show_state) 3117 buf[bx++] = '-'; 3118 /* Show a + for module-is-being-loaded */ 3119 if (mod->state == MODULE_STATE_COMING && show_state) 3120 buf[bx++] = '+'; 3121 buf[bx++] = ')'; 3122 } 3123 out: 3124 buf[bx] = '\0'; 3125 3126 return buf; 3127 } 3128 3129 /* Given an address, look for it in the module exception tables. */ 3130 const struct exception_table_entry *search_module_extables(unsigned long addr) 3131 { 3132 const struct exception_table_entry *e = NULL; 3133 struct module *mod; 3134 3135 preempt_disable(); 3136 mod = __module_address(addr); 3137 if (!mod) 3138 goto out; 3139 3140 if (!mod->num_exentries) 3141 goto out; 3142 3143 e = search_extable(mod->extable, 3144 mod->num_exentries, 3145 addr); 3146 out: 3147 preempt_enable(); 3148 3149 /* 3150 * Now, if we found one, we are running inside it now, hence 3151 * we cannot unload the module, hence no refcnt needed. 3152 */ 3153 return e; 3154 } 3155 3156 /** 3157 * is_module_address() - is this address inside a module? 3158 * @addr: the address to check. 3159 * 3160 * See is_module_text_address() if you simply want to see if the address 3161 * is code (not data). 3162 */ 3163 bool is_module_address(unsigned long addr) 3164 { 3165 bool ret; 3166 3167 preempt_disable(); 3168 ret = __module_address(addr) != NULL; 3169 preempt_enable(); 3170 3171 return ret; 3172 } 3173 3174 /** 3175 * __module_address() - get the module which contains an address. 3176 * @addr: the address. 3177 * 3178 * Must be called with preempt disabled or module mutex held so that 3179 * module doesn't get freed during this. 3180 */ 3181 struct module *__module_address(unsigned long addr) 3182 { 3183 struct module *mod; 3184 3185 if (addr >= mod_tree.addr_min && addr <= mod_tree.addr_max) 3186 goto lookup; 3187 3188 #ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC 3189 if (addr >= mod_tree.data_addr_min && addr <= mod_tree.data_addr_max) 3190 goto lookup; 3191 #endif 3192 3193 return NULL; 3194 3195 lookup: 3196 module_assert_mutex_or_preempt(); 3197 3198 mod = mod_find(addr, &mod_tree); 3199 if (mod) { 3200 BUG_ON(!within_module(addr, mod)); 3201 if (mod->state == MODULE_STATE_UNFORMED) 3202 mod = NULL; 3203 } 3204 return mod; 3205 } 3206 3207 /** 3208 * is_module_text_address() - is this address inside module code? 3209 * @addr: the address to check. 3210 * 3211 * See is_module_address() if you simply want to see if the address is 3212 * anywhere in a module. See kernel_text_address() for testing if an 3213 * address corresponds to kernel or module code. 3214 */ 3215 bool is_module_text_address(unsigned long addr) 3216 { 3217 bool ret; 3218 3219 preempt_disable(); 3220 ret = __module_text_address(addr) != NULL; 3221 preempt_enable(); 3222 3223 return ret; 3224 } 3225 3226 /** 3227 * __module_text_address() - get the module whose code contains an address. 3228 * @addr: the address. 3229 * 3230 * Must be called with preempt disabled or module mutex held so that 3231 * module doesn't get freed during this. 3232 */ 3233 struct module *__module_text_address(unsigned long addr) 3234 { 3235 struct module *mod = __module_address(addr); 3236 if (mod) { 3237 /* Make sure it's within the text section. */ 3238 if (!within_module_mem_type(addr, mod, MOD_TEXT) && 3239 !within_module_mem_type(addr, mod, MOD_INIT_TEXT)) 3240 mod = NULL; 3241 } 3242 return mod; 3243 } 3244 3245 /* Don't grab lock, we're oopsing. */ 3246 void print_modules(void) 3247 { 3248 struct module *mod; 3249 char buf[MODULE_FLAGS_BUF_SIZE]; 3250 3251 printk(KERN_DEFAULT "Modules linked in:"); 3252 /* Most callers should already have preempt disabled, but make sure */ 3253 preempt_disable(); 3254 list_for_each_entry_rcu(mod, &modules, list) { 3255 if (mod->state == MODULE_STATE_UNFORMED) 3256 continue; 3257 pr_cont(" %s%s", mod->name, module_flags(mod, buf, true)); 3258 } 3259 3260 print_unloaded_tainted_modules(); 3261 preempt_enable(); 3262 if (last_unloaded_module.name[0]) 3263 pr_cont(" [last unloaded: %s%s]", last_unloaded_module.name, 3264 last_unloaded_module.taints); 3265 pr_cont("\n"); 3266 } 3267 3268 #ifdef CONFIG_MODULE_DEBUGFS 3269 struct dentry *mod_debugfs_root; 3270 3271 static int module_debugfs_init(void) 3272 { 3273 mod_debugfs_root = debugfs_create_dir("modules", NULL); 3274 return 0; 3275 } 3276 module_init(module_debugfs_init); 3277 #endif 3278