1 /* $NetBSD: kern_module.c,v 1.84 2011/11/06 12:40:04 tron Exp $ */ 2 3 /*- 4 * Copyright (c) 2008 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software developed for The NetBSD Foundation 8 * by Andrew Doran. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 /* 33 * Kernel module support. 34 */ 35 36 #include <sys/cdefs.h> 37 __KERNEL_RCSID(0, "$NetBSD: kern_module.c,v 1.84 2011/11/06 12:40:04 tron Exp $"); 38 39 #define _MODULE_INTERNAL 40 41 #ifdef _KERNEL_OPT 42 #include "opt_ddb.h" 43 #include "opt_modular.h" 44 #endif 45 46 #include <sys/param.h> 47 #include <sys/systm.h> 48 #include <sys/kernel.h> 49 #include <sys/proc.h> 50 #include <sys/kauth.h> 51 #include <sys/kobj.h> 52 #include <sys/kmem.h> 53 #include <sys/module.h> 54 #include <sys/kthread.h> 55 #include <sys/sysctl.h> 56 #include <sys/lock.h> 57 58 #include <uvm/uvm_extern.h> 59 60 struct vm_map *module_map; 61 char *module_machine; 62 char module_base[MODULE_BASE_SIZE]; 63 64 struct modlist module_list = TAILQ_HEAD_INITIALIZER(module_list); 65 struct modlist module_builtins = TAILQ_HEAD_INITIALIZER(module_builtins); 66 static struct modlist module_bootlist = TAILQ_HEAD_INITIALIZER(module_bootlist); 67 68 static module_t *module_active; 69 static bool module_verbose_on; 70 static bool module_autoload_on = true; 71 u_int module_count; 72 u_int module_builtinlist; 73 u_int module_autotime = 10; 74 u_int module_gen = 1; 75 static kcondvar_t module_thread_cv; 76 static kmutex_t module_thread_lock; 77 static int module_thread_ticks; 78 int (*module_load_vfs_vec)(const char *, int, bool, module_t *, 79 prop_dictionary_t *) = (void *)eopnotsupp; 80 81 static kauth_listener_t module_listener; 82 83 /* Ensure that the kernel's link set isn't empty. */ 84 static modinfo_t module_dummy; 85 __link_set_add_rodata(modules, module_dummy); 86 87 static module_t *module_newmodule(modsrc_t); 88 static void module_require_force(module_t *); 89 static int module_do_load(const char *, bool, int, prop_dictionary_t, 90 module_t **, modclass_t class, bool); 91 static int module_do_unload(const char *, bool); 92 static int module_do_builtin(const char *, module_t **, prop_dictionary_t); 93 static int module_fetch_info(module_t *); 94 static void module_thread(void *); 95 96 static module_t *module_lookup(const char *); 97 static void module_enqueue(module_t *); 98 99 static bool module_merge_dicts(prop_dictionary_t, const prop_dictionary_t); 100 101 static void sysctl_module_setup(void); 102 103 /* 104 * module_error: 105 * 106 * Utility function: log an error. 107 */ 108 void 109 module_error(const char *fmt, ...) 110 { 111 va_list ap; 112 113 va_start(ap, fmt); 114 printf("WARNING: module error: "); 115 vprintf(fmt, ap); 116 printf("\n"); 117 va_end(ap); 118 } 119 120 /* 121 * module_print: 122 * 123 * Utility function: log verbose output. 124 */ 125 void 126 module_print(const char *fmt, ...) 127 { 128 va_list ap; 129 130 if (module_verbose_on) { 131 va_start(ap, fmt); 132 printf("DEBUG: module: "); 133 vprintf(fmt, ap); 134 printf("\n"); 135 va_end(ap); 136 } 137 } 138 139 static int 140 module_listener_cb(kauth_cred_t cred, kauth_action_t action, void *cookie, 141 void *arg0, void *arg1, void *arg2, void *arg3) 142 { 143 int result; 144 145 result = KAUTH_RESULT_DEFER; 146 147 if (action != KAUTH_SYSTEM_MODULE) 148 return result; 149 150 if ((uintptr_t)arg2 != 0) /* autoload */ 151 result = KAUTH_RESULT_ALLOW; 152 153 return result; 154 } 155 156 /* 157 * Allocate a new module_t 158 */ 159 static module_t * 160 module_newmodule(modsrc_t source) 161 { 162 module_t *mod; 163 164 mod = kmem_zalloc(sizeof(*mod), KM_SLEEP); 165 if (mod != NULL) { 166 mod->mod_source = source; 167 mod->mod_info = NULL; 168 mod->mod_flags = 0; 169 } 170 return mod; 171 } 172 173 /* 174 * Require the -f (force) flag to load a module 175 */ 176 static void 177 module_require_force(struct module *mod) 178 { 179 mod->mod_flags |= MODFLG_MUST_FORCE; 180 } 181 182 /* 183 * Add modules to the builtin list. This can done at boottime or 184 * at runtime if the module is linked into the kernel with an 185 * external linker. All or none of the input will be handled. 186 * Optionally, the modules can be initialized. If they are not 187 * initialized, module_init_class() or module_load() can be used 188 * later, but these are not guaranteed to give atomic results. 189 */ 190 int 191 module_builtin_add(modinfo_t *const *mip, size_t nmodinfo, bool init) 192 { 193 struct module **modp = NULL, *mod_iter; 194 int rv = 0, i, mipskip; 195 196 if (init) { 197 rv = kauth_authorize_system(kauth_cred_get(), 198 KAUTH_SYSTEM_MODULE, 0, (void *)(uintptr_t)MODCTL_LOAD, 199 (void *)(uintptr_t)1, NULL); 200 if (rv) { 201 return rv; 202 } 203 } 204 205 for (i = 0, mipskip = 0; i < nmodinfo; i++) { 206 if (mip[i] == &module_dummy) { 207 KASSERT(nmodinfo > 0); 208 nmodinfo--; 209 } 210 } 211 if (nmodinfo == 0) 212 return 0; 213 214 modp = kmem_zalloc(sizeof(*modp) * nmodinfo, KM_SLEEP); 215 for (i = 0, mipskip = 0; i < nmodinfo; i++) { 216 if (mip[i+mipskip] == &module_dummy) { 217 mipskip++; 218 continue; 219 } 220 modp[i] = module_newmodule(MODULE_SOURCE_KERNEL); 221 modp[i]->mod_info = mip[i+mipskip]; 222 } 223 kernconfig_lock(); 224 225 /* do this in three stages for error recovery and atomicity */ 226 227 /* first check for presence */ 228 for (i = 0; i < nmodinfo; i++) { 229 TAILQ_FOREACH(mod_iter, &module_builtins, mod_chain) { 230 if (strcmp(mod_iter->mod_info->mi_name, 231 modp[i]->mod_info->mi_name) == 0) 232 break; 233 } 234 if (mod_iter) { 235 rv = EEXIST; 236 goto out; 237 } 238 239 if (module_lookup(modp[i]->mod_info->mi_name) != NULL) { 240 rv = EEXIST; 241 goto out; 242 } 243 } 244 245 /* then add to list */ 246 for (i = 0; i < nmodinfo; i++) { 247 TAILQ_INSERT_TAIL(&module_builtins, modp[i], mod_chain); 248 module_builtinlist++; 249 } 250 251 /* finally, init (if required) */ 252 if (init) { 253 for (i = 0; i < nmodinfo; i++) { 254 rv = module_do_builtin(modp[i]->mod_info->mi_name, 255 NULL, NULL); 256 /* throw in the towel, recovery hard & not worth it */ 257 if (rv) 258 panic("builtin module \"%s\" init failed: %d", 259 modp[i]->mod_info->mi_name, rv); 260 } 261 } 262 263 out: 264 kernconfig_unlock(); 265 if (rv != 0) { 266 for (i = 0; i < nmodinfo; i++) { 267 if (modp[i]) 268 kmem_free(modp[i], sizeof(*modp[i])); 269 } 270 } 271 kmem_free(modp, sizeof(*modp) * nmodinfo); 272 return rv; 273 } 274 275 /* 276 * Optionally fini and remove builtin module from the kernel. 277 * Note: the module will now be unreachable except via mi && builtin_add. 278 */ 279 int 280 module_builtin_remove(modinfo_t *mi, bool fini) 281 { 282 struct module *mod; 283 int rv = 0; 284 285 if (fini) { 286 rv = kauth_authorize_system(kauth_cred_get(), 287 KAUTH_SYSTEM_MODULE, 0, (void *)(uintptr_t)MODCTL_UNLOAD, 288 NULL, NULL); 289 if (rv) 290 return rv; 291 292 kernconfig_lock(); 293 rv = module_do_unload(mi->mi_name, true); 294 if (rv) { 295 goto out; 296 } 297 } else { 298 kernconfig_lock(); 299 } 300 TAILQ_FOREACH(mod, &module_builtins, mod_chain) { 301 if (strcmp(mod->mod_info->mi_name, mi->mi_name) == 0) 302 break; 303 } 304 if (mod) { 305 TAILQ_REMOVE(&module_builtins, mod, mod_chain); 306 module_builtinlist--; 307 } else { 308 KASSERT(fini == false); 309 rv = ENOENT; 310 } 311 312 out: 313 kernconfig_unlock(); 314 return rv; 315 } 316 317 /* 318 * module_init: 319 * 320 * Initialize the module subsystem. 321 */ 322 void 323 module_init(void) 324 { 325 __link_set_decl(modules, modinfo_t); 326 extern struct vm_map *module_map; 327 modinfo_t *const *mip; 328 int rv; 329 330 if (module_map == NULL) { 331 module_map = kernel_map; 332 } 333 cv_init(&module_thread_cv, "mod_unld"); 334 mutex_init(&module_thread_lock, MUTEX_DEFAULT, IPL_NONE); 335 336 #ifdef MODULAR /* XXX */ 337 module_init_md(); 338 #endif 339 340 if (!module_machine) 341 module_machine = machine; 342 #if __NetBSD_Version__ / 1000000 % 100 == 99 /* -current */ 343 snprintf(module_base, sizeof(module_base), "/stand/%s/%s/modules", 344 module_machine, osrelease); 345 #else /* release */ 346 snprintf(module_base, sizeof(module_base), "/stand/%s/%d.%d/modules", 347 module_machine, __NetBSD_Version__ / 100000000, 348 __NetBSD_Version__ / 1000000 % 100); 349 #endif 350 351 module_listener = kauth_listen_scope(KAUTH_SCOPE_SYSTEM, 352 module_listener_cb, NULL); 353 354 __link_set_foreach(mip, modules) { 355 if ((rv = module_builtin_add(mip, 1, false)) != 0) 356 module_error("builtin %s failed: %d\n", 357 (*mip)->mi_name, rv); 358 } 359 360 sysctl_module_setup(); 361 } 362 363 /* 364 * module_start_unload_thread: 365 * 366 * Start the auto unload kthread. 367 */ 368 void 369 module_start_unload_thread(void) 370 { 371 int error; 372 373 error = kthread_create(PRI_VM, KTHREAD_MPSAFE, NULL, module_thread, 374 NULL, NULL, "modunload"); 375 if (error != 0) 376 panic("module_init: %d", error); 377 } 378 379 /* 380 * module_builtin_require_force 381 * 382 * Require MODCTL_MUST_FORCE to load any built-in modules that have 383 * not yet been initialized 384 */ 385 void 386 module_builtin_require_force(void) 387 { 388 module_t *mod; 389 390 kernconfig_lock(); 391 TAILQ_FOREACH(mod, &module_builtins, mod_chain) { 392 module_require_force(mod); 393 } 394 kernconfig_unlock(); 395 } 396 397 static struct sysctllog *module_sysctllog; 398 399 static void 400 sysctl_module_setup(void) 401 { 402 const struct sysctlnode *node = NULL; 403 404 sysctl_createv(&module_sysctllog, 0, NULL, NULL, 405 CTLFLAG_PERMANENT, 406 CTLTYPE_NODE, "kern", NULL, 407 NULL, 0, NULL, 0, 408 CTL_KERN, CTL_EOL); 409 sysctl_createv(&module_sysctllog, 0, NULL, &node, 410 CTLFLAG_PERMANENT, 411 CTLTYPE_NODE, "module", 412 SYSCTL_DESCR("Module options"), 413 NULL, 0, NULL, 0, 414 CTL_KERN, CTL_CREATE, CTL_EOL); 415 416 if (node == NULL) 417 return; 418 419 sysctl_createv(&module_sysctllog, 0, &node, NULL, 420 CTLFLAG_PERMANENT | CTLFLAG_READWRITE, 421 CTLTYPE_BOOL, "autoload", 422 SYSCTL_DESCR("Enable automatic load of modules"), 423 NULL, 0, &module_autoload_on, 0, 424 CTL_CREATE, CTL_EOL); 425 sysctl_createv(&module_sysctllog, 0, &node, NULL, 426 CTLFLAG_PERMANENT | CTLFLAG_READWRITE, 427 CTLTYPE_BOOL, "verbose", 428 SYSCTL_DESCR("Enable verbose output"), 429 NULL, 0, &module_verbose_on, 0, 430 CTL_CREATE, CTL_EOL); 431 } 432 433 /* 434 * module_init_class: 435 * 436 * Initialize all built-in and pre-loaded modules of the 437 * specified class. 438 */ 439 void 440 module_init_class(modclass_t class) 441 { 442 TAILQ_HEAD(, module) bi_fail = TAILQ_HEAD_INITIALIZER(bi_fail); 443 module_t *mod; 444 modinfo_t *mi; 445 446 kernconfig_lock(); 447 /* 448 * Builtins first. These will not depend on pre-loaded modules 449 * (because the kernel would not link). 450 */ 451 do { 452 TAILQ_FOREACH(mod, &module_builtins, mod_chain) { 453 mi = mod->mod_info; 454 if (class != MODULE_CLASS_ANY && class != mi->mi_class) 455 continue; 456 /* 457 * If initializing a builtin module fails, don't try 458 * to load it again. But keep it around and queue it 459 * on the builtins list after we're done with module 460 * init. Don't set it to MODFLG_MUST_FORCE in case a 461 * future attempt to initialize can be successful. 462 * (If the module has previously been set to 463 * MODFLG_MUST_FORCE, don't try to override that!) 464 */ 465 if (mod->mod_flags & MODFLG_MUST_FORCE || 466 module_do_builtin(mi->mi_name, NULL, NULL) != 0) { 467 TAILQ_REMOVE(&module_builtins, mod, mod_chain); 468 TAILQ_INSERT_TAIL(&bi_fail, mod, mod_chain); 469 } 470 break; 471 } 472 } while (mod != NULL); 473 474 /* 475 * Now preloaded modules. These will be pulled off the 476 * list as we call module_do_load(); 477 */ 478 do { 479 TAILQ_FOREACH(mod, &module_bootlist, mod_chain) { 480 mi = mod->mod_info; 481 if (class != MODULE_CLASS_ANY && class != mi->mi_class) 482 continue; 483 module_do_load(mi->mi_name, false, 0, NULL, NULL, 484 class, false); 485 break; 486 } 487 } while (mod != NULL); 488 489 /* return failed builtin modules to builtin list */ 490 while ((mod = TAILQ_FIRST(&bi_fail)) != NULL) { 491 TAILQ_REMOVE(&bi_fail, mod, mod_chain); 492 TAILQ_INSERT_TAIL(&module_builtins, mod, mod_chain); 493 } 494 495 kernconfig_unlock(); 496 } 497 498 /* 499 * module_compatible: 500 * 501 * Return true if the two supplied kernel versions are said to 502 * have the same binary interface for kernel code. The entire 503 * version is signficant for the development tree (-current), 504 * major and minor versions are significant for official 505 * releases of the system. 506 */ 507 bool 508 module_compatible(int v1, int v2) 509 { 510 511 #if __NetBSD_Version__ / 1000000 % 100 == 99 /* -current */ 512 return v1 == v2; 513 #else /* release */ 514 return abs(v1 - v2) < 10000; 515 #endif 516 } 517 518 /* 519 * module_load: 520 * 521 * Load a single module from the file system. 522 */ 523 int 524 module_load(const char *filename, int flags, prop_dictionary_t props, 525 modclass_t class) 526 { 527 int error; 528 529 /* Authorize. */ 530 error = kauth_authorize_system(kauth_cred_get(), KAUTH_SYSTEM_MODULE, 531 0, (void *)(uintptr_t)MODCTL_LOAD, NULL, NULL); 532 if (error != 0) { 533 return error; 534 } 535 536 kernconfig_lock(); 537 error = module_do_load(filename, false, flags, props, NULL, class, 538 false); 539 kernconfig_unlock(); 540 541 return error; 542 } 543 544 /* 545 * module_autoload: 546 * 547 * Load a single module from the file system, system initiated. 548 */ 549 int 550 module_autoload(const char *filename, modclass_t class) 551 { 552 int error; 553 554 kernconfig_lock(); 555 556 /* Nothing if the user has disabled it. */ 557 if (!module_autoload_on) { 558 kernconfig_unlock(); 559 return EPERM; 560 } 561 562 /* Disallow path separators and magic symlinks. */ 563 if (strchr(filename, '/') != NULL || strchr(filename, '@') != NULL || 564 strchr(filename, '.') != NULL) { 565 kernconfig_unlock(); 566 return EPERM; 567 } 568 569 /* Authorize. */ 570 error = kauth_authorize_system(kauth_cred_get(), KAUTH_SYSTEM_MODULE, 571 0, (void *)(uintptr_t)MODCTL_LOAD, (void *)(uintptr_t)1, NULL); 572 573 if (error == 0) 574 error = module_do_load(filename, false, 0, NULL, NULL, class, 575 true); 576 577 kernconfig_unlock(); 578 return error; 579 } 580 581 /* 582 * module_unload: 583 * 584 * Find and unload a module by name. 585 */ 586 int 587 module_unload(const char *name) 588 { 589 int error; 590 591 /* Authorize. */ 592 error = kauth_authorize_system(kauth_cred_get(), KAUTH_SYSTEM_MODULE, 593 0, (void *)(uintptr_t)MODCTL_UNLOAD, NULL, NULL); 594 if (error != 0) { 595 return error; 596 } 597 598 kernconfig_lock(); 599 error = module_do_unload(name, true); 600 kernconfig_unlock(); 601 602 return error; 603 } 604 605 /* 606 * module_lookup: 607 * 608 * Look up a module by name. 609 */ 610 module_t * 611 module_lookup(const char *name) 612 { 613 module_t *mod; 614 615 KASSERT(kernconfig_is_held()); 616 617 TAILQ_FOREACH(mod, &module_list, mod_chain) { 618 if (strcmp(mod->mod_info->mi_name, name) == 0) { 619 break; 620 } 621 } 622 623 return mod; 624 } 625 626 /* 627 * module_hold: 628 * 629 * Add a single reference to a module. It's the caller's 630 * responsibility to ensure that the reference is dropped 631 * later. 632 */ 633 int 634 module_hold(const char *name) 635 { 636 module_t *mod; 637 638 kernconfig_lock(); 639 mod = module_lookup(name); 640 if (mod == NULL) { 641 kernconfig_unlock(); 642 return ENOENT; 643 } 644 mod->mod_refcnt++; 645 kernconfig_unlock(); 646 647 return 0; 648 } 649 650 /* 651 * module_rele: 652 * 653 * Release a reference acquired with module_hold(). 654 */ 655 void 656 module_rele(const char *name) 657 { 658 module_t *mod; 659 660 kernconfig_lock(); 661 mod = module_lookup(name); 662 if (mod == NULL) { 663 kernconfig_unlock(); 664 panic("module_rele: gone"); 665 } 666 mod->mod_refcnt--; 667 kernconfig_unlock(); 668 } 669 670 /* 671 * module_enqueue: 672 * 673 * Put a module onto the global list and update counters. 674 */ 675 void 676 module_enqueue(module_t *mod) 677 { 678 int i; 679 680 KASSERT(kernconfig_is_held()); 681 682 /* 683 * If there are requisite modules, put at the head of the queue. 684 * This is so that autounload can unload requisite modules with 685 * only one pass through the queue. 686 */ 687 if (mod->mod_nrequired) { 688 TAILQ_INSERT_HEAD(&module_list, mod, mod_chain); 689 690 /* Add references to the requisite modules. */ 691 for (i = 0; i < mod->mod_nrequired; i++) { 692 KASSERT(mod->mod_required[i] != NULL); 693 mod->mod_required[i]->mod_refcnt++; 694 } 695 } else { 696 TAILQ_INSERT_TAIL(&module_list, mod, mod_chain); 697 } 698 module_count++; 699 module_gen++; 700 } 701 702 /* 703 * module_do_builtin: 704 * 705 * Initialize a module from the list of modules that are 706 * already linked into the kernel. 707 */ 708 static int 709 module_do_builtin(const char *name, module_t **modp, prop_dictionary_t props) 710 { 711 const char *p, *s; 712 char buf[MAXMODNAME]; 713 modinfo_t *mi = NULL; 714 module_t *mod, *mod2, *mod_loaded, *prev_active; 715 size_t len; 716 int error; 717 718 KASSERT(kernconfig_is_held()); 719 720 /* 721 * Search the list to see if we have a module by this name. 722 */ 723 TAILQ_FOREACH(mod, &module_builtins, mod_chain) { 724 if (strcmp(mod->mod_info->mi_name, name) == 0) { 725 mi = mod->mod_info; 726 break; 727 } 728 } 729 730 /* 731 * Check to see if already loaded. This might happen if we 732 * were already loaded as a dependency. 733 */ 734 if ((mod_loaded = module_lookup(name)) != NULL) { 735 KASSERT(mod == NULL); 736 if (modp) 737 *modp = mod_loaded; 738 return 0; 739 } 740 741 /* Note! This is from TAILQ, not immediate above */ 742 if (mi == NULL) { 743 /* 744 * XXX: We'd like to panic here, but currently in some 745 * cases (such as nfsserver + nfs), the dependee can be 746 * succesfully linked without the dependencies. 747 */ 748 module_error("can't find builtin dependency `%s'", name); 749 return ENOENT; 750 } 751 752 /* 753 * Initialize pre-requisites. 754 */ 755 if (mi->mi_required != NULL) { 756 for (s = mi->mi_required; *s != '\0'; s = p) { 757 if (*s == ',') 758 s++; 759 p = s; 760 while (*p != '\0' && *p != ',') 761 p++; 762 len = min(p - s + 1, sizeof(buf)); 763 strlcpy(buf, s, len); 764 if (buf[0] == '\0') 765 break; 766 if (mod->mod_nrequired == MAXMODDEPS - 1) { 767 module_error("too many required modules"); 768 return EINVAL; 769 } 770 error = module_do_builtin(buf, &mod2, NULL); 771 if (error != 0) { 772 return error; 773 } 774 mod->mod_required[mod->mod_nrequired++] = mod2; 775 } 776 } 777 778 /* 779 * Try to initialize the module. 780 */ 781 prev_active = module_active; 782 module_active = mod; 783 error = (*mi->mi_modcmd)(MODULE_CMD_INIT, props); 784 module_active = prev_active; 785 if (error != 0) { 786 module_error("builtin module `%s' " 787 "failed to init", mi->mi_name); 788 return error; 789 } 790 791 /* load always succeeds after this point */ 792 793 TAILQ_REMOVE(&module_builtins, mod, mod_chain); 794 module_builtinlist--; 795 if (modp != NULL) { 796 *modp = mod; 797 } 798 if (mi->mi_class == MODULE_CLASS_SECMODEL) 799 secmodel_register(); 800 module_enqueue(mod); 801 return 0; 802 } 803 804 /* 805 * module_do_load: 806 * 807 * Helper routine: load a module from the file system, or one 808 * pushed by the boot loader. 809 */ 810 static int 811 module_do_load(const char *name, bool isdep, int flags, 812 prop_dictionary_t props, module_t **modp, modclass_t class, 813 bool autoload) 814 { 815 #define MODULE_MAX_DEPTH 6 816 817 TAILQ_HEAD(pending_t, module); 818 static int depth = 0; 819 static struct pending_t *pending_lists[MODULE_MAX_DEPTH]; 820 struct pending_t *pending; 821 struct pending_t new_pending = TAILQ_HEAD_INITIALIZER(new_pending); 822 modinfo_t *mi; 823 module_t *mod, *mod2, *prev_active; 824 prop_dictionary_t filedict; 825 char buf[MAXMODNAME]; 826 const char *s, *p; 827 int error; 828 size_t len; 829 830 KASSERT(kernconfig_is_held()); 831 832 filedict = NULL; 833 error = 0; 834 835 /* 836 * Avoid recursing too far. 837 */ 838 if (++depth > MODULE_MAX_DEPTH) { 839 module_error("recursion too deep"); 840 depth--; 841 return EMLINK; 842 } 843 844 /* 845 * Set up the pending list for this depth. If this is a 846 * recursive entry, then use same list as for outer call, 847 * else use the locally allocated list. In either case, 848 * remember which one we're using. 849 */ 850 if (isdep) { 851 KASSERT(depth > 1); 852 pending = pending_lists[depth - 2]; 853 } else 854 pending = &new_pending; 855 pending_lists[depth - 1] = pending; 856 857 /* 858 * Search the list of disabled builtins first. 859 */ 860 TAILQ_FOREACH(mod, &module_builtins, mod_chain) { 861 if (strcmp(mod->mod_info->mi_name, name) == 0) { 862 break; 863 } 864 } 865 if (mod) { 866 if ((mod->mod_flags & MODFLG_MUST_FORCE) && 867 (flags & MODCTL_LOAD_FORCE) == 0) { 868 if (!autoload) { 869 module_error("use -f to reinstate " 870 "builtin module \"%s\"", name); 871 } 872 depth--; 873 return EPERM; 874 } else { 875 error = module_do_builtin(name, modp, props); 876 depth--; 877 return error; 878 } 879 } 880 881 /* 882 * Load the module and link. Before going to the file system, 883 * scan the list of modules loaded by the boot loader. 884 */ 885 TAILQ_FOREACH(mod, &module_bootlist, mod_chain) { 886 if (strcmp(mod->mod_info->mi_name, name) == 0) { 887 TAILQ_REMOVE(&module_bootlist, mod, mod_chain); 888 break; 889 } 890 } 891 if (mod != NULL) { 892 TAILQ_INSERT_TAIL(pending, mod, mod_chain); 893 } else { 894 /* 895 * If a requisite module, check to see if it is 896 * already present. 897 */ 898 if (isdep) { 899 mod = module_lookup(name); 900 if (mod != NULL) { 901 if (modp != NULL) { 902 *modp = mod; 903 } 904 depth--; 905 return 0; 906 } 907 } 908 mod = module_newmodule(MODULE_SOURCE_FILESYS); 909 if (mod == NULL) { 910 module_error("out of memory for `%s'", name); 911 depth--; 912 return ENOMEM; 913 } 914 915 error = module_load_vfs_vec(name, flags, autoload, mod, 916 &filedict); 917 if (error != 0) { 918 kmem_free(mod, sizeof(*mod)); 919 depth--; 920 return error; 921 } 922 TAILQ_INSERT_TAIL(pending, mod, mod_chain); 923 924 error = module_fetch_info(mod); 925 if (error != 0) { 926 module_error("cannot fetch module info for `%s'", 927 name); 928 goto fail; 929 } 930 } 931 932 /* 933 * Check compatibility. 934 */ 935 mi = mod->mod_info; 936 if (strlen(mi->mi_name) >= MAXMODNAME) { 937 error = EINVAL; 938 module_error("module name `%s' too long", mi->mi_name); 939 goto fail; 940 } 941 if (!module_compatible(mi->mi_version, __NetBSD_Version__)) { 942 module_error("module built for `%d', system `%d'", 943 mi->mi_version, __NetBSD_Version__); 944 if ((flags & MODCTL_LOAD_FORCE) != 0) { 945 module_error("forced load, system may be unstable"); 946 } else { 947 error = EPROGMISMATCH; 948 goto fail; 949 } 950 } 951 952 /* 953 * If a specific kind of module was requested, ensure that we have 954 * a match. 955 */ 956 if (class != MODULE_CLASS_ANY && class != mi->mi_class) { 957 module_print("incompatible module class for `%s' (%d != %d)", 958 name, class, mi->mi_class); 959 error = ENOENT; 960 goto fail; 961 } 962 963 /* 964 * If loading a dependency, `name' is a plain module name. 965 * The name must match. 966 */ 967 if (isdep && strcmp(mi->mi_name, name) != 0) { 968 module_error("dependency name mismatch (`%s' != `%s')", 969 name, mi->mi_name); 970 error = ENOENT; 971 goto fail; 972 } 973 974 /* 975 * Check to see if the module is already loaded. If so, we may 976 * have been recursively called to handle a dependency, so be sure 977 * to set modp. 978 */ 979 if ((mod2 = module_lookup(mi->mi_name)) != NULL) { 980 if (modp != NULL) 981 *modp = mod2; 982 module_print("module `%s' already loaded", mi->mi_name); 983 error = EEXIST; 984 goto fail; 985 } 986 987 /* 988 * Block circular dependencies. 989 */ 990 TAILQ_FOREACH(mod2, pending, mod_chain) { 991 if (mod == mod2) { 992 continue; 993 } 994 if (strcmp(mod2->mod_info->mi_name, mi->mi_name) == 0) { 995 error = EDEADLK; 996 module_error("circular dependency detected for `%s'", 997 mi->mi_name); 998 goto fail; 999 } 1000 } 1001 1002 /* 1003 * Now try to load any requisite modules. 1004 */ 1005 if (mi->mi_required != NULL) { 1006 for (s = mi->mi_required; *s != '\0'; s = p) { 1007 if (*s == ',') 1008 s++; 1009 p = s; 1010 while (*p != '\0' && *p != ',') 1011 p++; 1012 len = p - s + 1; 1013 if (len >= MAXMODNAME) { 1014 error = EINVAL; 1015 module_error("required module name `%s'" 1016 " too long", mi->mi_required); 1017 goto fail; 1018 } 1019 strlcpy(buf, s, len); 1020 if (buf[0] == '\0') 1021 break; 1022 if (mod->mod_nrequired == MAXMODDEPS - 1) { 1023 error = EINVAL; 1024 module_error("too many required modules (%d)", 1025 mod->mod_nrequired); 1026 goto fail; 1027 } 1028 if (strcmp(buf, mi->mi_name) == 0) { 1029 error = EDEADLK; 1030 module_error("self-dependency detected for " 1031 "`%s'", mi->mi_name); 1032 goto fail; 1033 } 1034 error = module_do_load(buf, true, flags, NULL, 1035 &mod2, MODULE_CLASS_ANY, true); 1036 if (error != 0) 1037 goto fail; 1038 mod->mod_required[mod->mod_nrequired++] = mod2; 1039 } 1040 } 1041 1042 /* 1043 * We loaded all needed modules successfully: perform global 1044 * relocations and initialize. 1045 */ 1046 error = kobj_affix(mod->mod_kobj, mi->mi_name); 1047 if (error != 0) { 1048 /* Cannot touch 'mi' as the module is now gone. */ 1049 module_error("unable to affix module `%s'", name); 1050 goto fail2; 1051 } 1052 1053 if (filedict) { 1054 if (!module_merge_dicts(filedict, props)) { 1055 module_error("module properties failed"); 1056 error = EINVAL; 1057 goto fail; 1058 } 1059 } 1060 prev_active = module_active; 1061 module_active = mod; 1062 error = (*mi->mi_modcmd)(MODULE_CMD_INIT, filedict ? filedict : props); 1063 module_active = prev_active; 1064 if (filedict) { 1065 prop_object_release(filedict); 1066 filedict = NULL; 1067 } 1068 if (error != 0) { 1069 module_error("modcmd function returned error %d for `%s'", 1070 error, mi->mi_name); 1071 goto fail; 1072 } 1073 1074 if (mi->mi_class == MODULE_CLASS_SECMODEL) 1075 secmodel_register(); 1076 1077 /* 1078 * Good, the module loaded successfully. Put it onto the 1079 * list and add references to its requisite modules. 1080 */ 1081 TAILQ_REMOVE(pending, mod, mod_chain); 1082 module_enqueue(mod); 1083 if (modp != NULL) { 1084 *modp = mod; 1085 } 1086 if (autoload) { 1087 /* 1088 * Arrange to try unloading the module after 1089 * a short delay. 1090 */ 1091 mod->mod_autotime = time_second + module_autotime; 1092 mod->mod_flags |= MODFLG_AUTO_LOADED; 1093 module_thread_kick(); 1094 } 1095 depth--; 1096 return 0; 1097 1098 fail: 1099 kobj_unload(mod->mod_kobj); 1100 fail2: 1101 if (filedict != NULL) { 1102 prop_object_release(filedict); 1103 filedict = NULL; 1104 } 1105 TAILQ_REMOVE(pending, mod, mod_chain); 1106 kmem_free(mod, sizeof(*mod)); 1107 depth--; 1108 return error; 1109 } 1110 1111 /* 1112 * module_do_unload: 1113 * 1114 * Helper routine: do the dirty work of unloading a module. 1115 */ 1116 static int 1117 module_do_unload(const char *name, bool load_requires_force) 1118 { 1119 module_t *mod, *prev_active; 1120 int error; 1121 u_int i; 1122 1123 KASSERT(kernconfig_is_held()); 1124 1125 mod = module_lookup(name); 1126 if (mod == NULL) { 1127 module_error("module `%s' not found", name); 1128 return ENOENT; 1129 } 1130 if (mod->mod_refcnt != 0) { 1131 module_print("module `%s' busy", name); 1132 return EBUSY; 1133 } 1134 1135 /* 1136 * Builtin secmodels are there to stay. 1137 */ 1138 if (mod->mod_source == MODULE_SOURCE_KERNEL && 1139 mod->mod_info->mi_class == MODULE_CLASS_SECMODEL) { 1140 return EPERM; 1141 } 1142 1143 prev_active = module_active; 1144 module_active = mod; 1145 error = (*mod->mod_info->mi_modcmd)(MODULE_CMD_FINI, NULL); 1146 module_active = prev_active; 1147 if (error != 0) { 1148 module_print("cannot unload module `%s' error=%d", name, 1149 error); 1150 return error; 1151 } 1152 if (mod->mod_info->mi_class == MODULE_CLASS_SECMODEL) 1153 secmodel_deregister(); 1154 module_count--; 1155 TAILQ_REMOVE(&module_list, mod, mod_chain); 1156 for (i = 0; i < mod->mod_nrequired; i++) { 1157 mod->mod_required[i]->mod_refcnt--; 1158 } 1159 if (mod->mod_kobj != NULL) { 1160 kobj_unload(mod->mod_kobj); 1161 } 1162 if (mod->mod_source == MODULE_SOURCE_KERNEL) { 1163 mod->mod_nrequired = 0; /* will be re-parsed */ 1164 if (load_requires_force) 1165 module_require_force(mod); 1166 TAILQ_INSERT_TAIL(&module_builtins, mod, mod_chain); 1167 module_builtinlist++; 1168 } else { 1169 kmem_free(mod, sizeof(*mod)); 1170 } 1171 module_gen++; 1172 1173 module_print("unloaded module `%s'", name); 1174 return 0; 1175 } 1176 1177 /* 1178 * module_prime: 1179 * 1180 * Push a module loaded by the bootloader onto our internal 1181 * list. 1182 */ 1183 int 1184 module_prime(const char *name, void *base, size_t size) 1185 { 1186 module_t *mod; 1187 int error; 1188 1189 mod = module_newmodule(MODULE_SOURCE_BOOT); 1190 if (mod == NULL) { 1191 return ENOMEM; 1192 } 1193 1194 error = kobj_load_mem(&mod->mod_kobj, name, base, size); 1195 if (error != 0) { 1196 kmem_free(mod, sizeof(*mod)); 1197 module_error("unable to load object pushed by boot loader"); 1198 return error; 1199 } 1200 error = module_fetch_info(mod); 1201 if (error != 0) { 1202 kobj_unload(mod->mod_kobj); 1203 kmem_free(mod, sizeof(*mod)); 1204 module_error("unable to load object pushed by boot loader"); 1205 return error; 1206 } 1207 1208 TAILQ_INSERT_TAIL(&module_bootlist, mod, mod_chain); 1209 1210 return 0; 1211 } 1212 1213 /* 1214 * module_fetch_into: 1215 * 1216 * Fetch modinfo record from a loaded module. 1217 */ 1218 static int 1219 module_fetch_info(module_t *mod) 1220 { 1221 int error; 1222 void *addr; 1223 size_t size; 1224 1225 /* 1226 * Find module info record and check compatibility. 1227 */ 1228 error = kobj_find_section(mod->mod_kobj, "link_set_modules", 1229 &addr, &size); 1230 if (error != 0) { 1231 module_error("`link_set_modules' section not present"); 1232 return error; 1233 } 1234 if (size != sizeof(modinfo_t **)) { 1235 module_error("`link_set_modules' section wrong size"); 1236 return ENOEXEC; 1237 } 1238 mod->mod_info = *(modinfo_t **)addr; 1239 1240 return 0; 1241 } 1242 1243 /* 1244 * module_find_section: 1245 * 1246 * Allows a module that is being initialized to look up a section 1247 * within its ELF object. 1248 */ 1249 int 1250 module_find_section(const char *name, void **addr, size_t *size) 1251 { 1252 1253 KASSERT(kernconfig_is_held()); 1254 KASSERT(module_active != NULL); 1255 1256 return kobj_find_section(module_active->mod_kobj, name, addr, size); 1257 } 1258 1259 /* 1260 * module_thread: 1261 * 1262 * Automatically unload modules. We try once to unload autoloaded 1263 * modules after module_autotime seconds. If the system is under 1264 * severe memory pressure, we'll try unloading all modules. 1265 */ 1266 static void 1267 module_thread(void *cookie) 1268 { 1269 module_t *mod, *next; 1270 modinfo_t *mi; 1271 int error; 1272 1273 for (;;) { 1274 kernconfig_lock(); 1275 for (mod = TAILQ_FIRST(&module_list); mod != NULL; mod = next) { 1276 next = TAILQ_NEXT(mod, mod_chain); 1277 1278 /* skip built-in modules */ 1279 if (mod->mod_source == MODULE_SOURCE_KERNEL) 1280 continue; 1281 /* skip modules that weren't auto-loaded */ 1282 if ((mod->mod_flags & MODFLG_AUTO_LOADED) == 0) 1283 continue; 1284 1285 if (uvmexp.free < uvmexp.freemin) { 1286 module_thread_ticks = hz; 1287 } else if (mod->mod_autotime == 0) { 1288 continue; 1289 } else if (time_second < mod->mod_autotime) { 1290 module_thread_ticks = hz; 1291 continue; 1292 } else { 1293 mod->mod_autotime = 0; 1294 } 1295 1296 /* 1297 * If this module wants to avoid autounload then 1298 * skip it. Some modules can ping-pong in and out 1299 * because their use is transient but often. 1300 * Example: exec_script. 1301 */ 1302 mi = mod->mod_info; 1303 error = (*mi->mi_modcmd)(MODULE_CMD_AUTOUNLOAD, NULL); 1304 if (error == 0 || error == ENOTTY) { 1305 (void)module_do_unload(mi->mi_name, false); 1306 } 1307 } 1308 kernconfig_unlock(); 1309 1310 mutex_enter(&module_thread_lock); 1311 (void)cv_timedwait(&module_thread_cv, &module_thread_lock, 1312 module_thread_ticks); 1313 module_thread_ticks = 0; 1314 mutex_exit(&module_thread_lock); 1315 } 1316 } 1317 1318 /* 1319 * module_thread: 1320 * 1321 * Kick the module thread into action, perhaps because the 1322 * system is low on memory. 1323 */ 1324 void 1325 module_thread_kick(void) 1326 { 1327 1328 mutex_enter(&module_thread_lock); 1329 module_thread_ticks = hz; 1330 cv_broadcast(&module_thread_cv); 1331 mutex_exit(&module_thread_lock); 1332 } 1333 1334 #ifdef DDB 1335 /* 1336 * module_whatis: 1337 * 1338 * Helper routine for DDB. 1339 */ 1340 void 1341 module_whatis(uintptr_t addr, void (*pr)(const char *, ...)) 1342 { 1343 module_t *mod; 1344 size_t msize; 1345 vaddr_t maddr; 1346 1347 TAILQ_FOREACH(mod, &module_list, mod_chain) { 1348 if (mod->mod_kobj == NULL) { 1349 continue; 1350 } 1351 if (kobj_stat(mod->mod_kobj, &maddr, &msize) != 0) 1352 continue; 1353 if (addr < maddr || addr >= maddr + msize) { 1354 continue; 1355 } 1356 (*pr)("%p is %p+%zu, in kernel module `%s'\n", 1357 (void *)addr, (void *)maddr, 1358 (size_t)(addr - maddr), mod->mod_info->mi_name); 1359 } 1360 } 1361 1362 /* 1363 * module_print_list: 1364 * 1365 * Helper routine for DDB. 1366 */ 1367 void 1368 module_print_list(void (*pr)(const char *, ...)) 1369 { 1370 const char *src; 1371 module_t *mod; 1372 size_t msize; 1373 vaddr_t maddr; 1374 1375 (*pr)("%16s %16s %8s %8s\n", "NAME", "TEXT/DATA", "SIZE", "SOURCE"); 1376 1377 TAILQ_FOREACH(mod, &module_list, mod_chain) { 1378 switch (mod->mod_source) { 1379 case MODULE_SOURCE_KERNEL: 1380 src = "builtin"; 1381 break; 1382 case MODULE_SOURCE_FILESYS: 1383 src = "filesys"; 1384 break; 1385 case MODULE_SOURCE_BOOT: 1386 src = "boot"; 1387 break; 1388 default: 1389 src = "unknown"; 1390 break; 1391 } 1392 if (mod->mod_kobj == NULL) { 1393 maddr = 0; 1394 msize = 0; 1395 } else if (kobj_stat(mod->mod_kobj, &maddr, &msize) != 0) 1396 continue; 1397 (*pr)("%16s %16lx %8ld %8s\n", mod->mod_info->mi_name, 1398 (long)maddr, (long)msize, src); 1399 } 1400 } 1401 #endif /* DDB */ 1402 1403 static bool 1404 module_merge_dicts(prop_dictionary_t existing_dict, 1405 const prop_dictionary_t new_dict) 1406 { 1407 prop_dictionary_keysym_t props_keysym; 1408 prop_object_iterator_t props_iter; 1409 prop_object_t props_obj; 1410 const char *props_key; 1411 bool error; 1412 1413 if (new_dict == NULL) { /* nothing to merge */ 1414 return true; 1415 } 1416 1417 error = false; 1418 props_iter = prop_dictionary_iterator(new_dict); 1419 if (props_iter == NULL) { 1420 return false; 1421 } 1422 1423 while ((props_obj = prop_object_iterator_next(props_iter)) != NULL) { 1424 props_keysym = (prop_dictionary_keysym_t)props_obj; 1425 props_key = prop_dictionary_keysym_cstring_nocopy(props_keysym); 1426 props_obj = prop_dictionary_get_keysym(new_dict, props_keysym); 1427 if ((props_obj == NULL) || !prop_dictionary_set(existing_dict, 1428 props_key, props_obj)) { 1429 error = true; 1430 goto out; 1431 } 1432 } 1433 error = false; 1434 1435 out: 1436 prop_object_iterator_release(props_iter); 1437 1438 return !error; 1439 } 1440