1 /* $NetBSD: kern_module.c,v 1.75 2011/01/14 10:18:21 martin 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 1.75 2011/01/14 10:18:21 martin 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 #include <machine/stdarg.h> 61 62 struct vm_map *module_map; 63 char module_base[MODULE_BASE_SIZE]; 64 65 struct modlist module_list = TAILQ_HEAD_INITIALIZER(module_list); 66 struct modlist module_builtins = TAILQ_HEAD_INITIALIZER(module_builtins); 67 static struct modlist module_bootlist = TAILQ_HEAD_INITIALIZER(module_bootlist); 68 69 static module_t *module_active; 70 static bool module_verbose_on; 71 static bool module_autoload_on = true; 72 u_int module_count; 73 u_int module_builtinlist; 74 u_int module_autotime = 10; 75 u_int module_gen = 1; 76 static kcondvar_t module_thread_cv; 77 static kmutex_t module_thread_lock; 78 static int module_thread_ticks; 79 int (*module_load_vfs_vec)(const char *, int, bool, module_t *, 80 prop_dictionary_t *) = (void *)eopnotsupp; 81 82 static kauth_listener_t module_listener; 83 84 /* Ensure that the kernel's link set isn't empty. */ 85 static modinfo_t module_dummy; 86 __link_set_add_rodata(modules, module_dummy); 87 88 static module_t *module_newmodule(modsrc_t); 89 static void module_require_force(module_t *); 90 static int module_do_load(const char *, bool, int, prop_dictionary_t, 91 module_t **, modclass_t class, bool); 92 static int module_do_unload(const char *, bool); 93 static int module_do_builtin(const char *, module_t **, prop_dictionary_t); 94 static int module_fetch_info(module_t *); 95 static void module_thread(void *); 96 97 static module_t *module_lookup(const char *); 98 static void module_enqueue(module_t *); 99 100 static bool module_merge_dicts(prop_dictionary_t, const prop_dictionary_t); 101 102 static void sysctl_module_setup(void); 103 104 /* 105 * module_error: 106 * 107 * Utility function: log an error. 108 */ 109 void 110 module_error(const char *fmt, ...) 111 { 112 va_list ap; 113 114 va_start(ap, fmt); 115 printf("WARNING: module error: "); 116 vprintf(fmt, ap); 117 printf("\n"); 118 va_end(ap); 119 } 120 121 /* 122 * module_print: 123 * 124 * Utility function: log verbose output. 125 */ 126 void 127 module_print(const char *fmt, ...) 128 { 129 va_list ap; 130 131 if (module_verbose_on) { 132 va_start(ap, fmt); 133 printf("DEBUG: module: "); 134 vprintf(fmt, ap); 135 printf("\n"); 136 va_end(ap); 137 } 138 } 139 140 static int 141 module_listener_cb(kauth_cred_t cred, kauth_action_t action, void *cookie, 142 void *arg0, void *arg1, void *arg2, void *arg3) 143 { 144 int result; 145 146 result = KAUTH_RESULT_DEFER; 147 148 if (action != KAUTH_SYSTEM_MODULE) 149 return result; 150 151 if ((uintptr_t)arg2 != 0) /* autoload */ 152 result = KAUTH_RESULT_ALLOW; 153 154 return result; 155 } 156 157 /* 158 * Allocate a new module_t 159 */ 160 static module_t * 161 module_newmodule(modsrc_t source) 162 { 163 module_t *mod; 164 165 mod = kmem_zalloc(sizeof(*mod), KM_SLEEP); 166 if (mod != NULL) { 167 mod->mod_source = source; 168 mod->mod_info = NULL; 169 mod->mod_flags = 0; 170 } 171 return mod; 172 } 173 174 /* 175 * Require the -f (force) flag to load a module 176 */ 177 static void 178 module_require_force(struct module *mod) 179 { 180 mod->mod_flags |= MODFLG_MUST_FORCE; 181 } 182 183 /* 184 * Add modules to the builtin list. This can done at boottime or 185 * at runtime if the module is linked into the kernel with an 186 * external linker. All or none of the input will be handled. 187 * Optionally, the modules can be initialized. If they are not 188 * initialized, module_init_class() or module_load() can be used 189 * later, but these are not guaranteed to give atomic results. 190 */ 191 int 192 module_builtin_add(modinfo_t *const *mip, size_t nmodinfo, bool init) 193 { 194 struct module **modp = NULL, *mod_iter; 195 int rv = 0, i, mipskip; 196 197 if (init) { 198 rv = kauth_authorize_system(kauth_cred_get(), 199 KAUTH_SYSTEM_MODULE, 0, (void *)(uintptr_t)MODCTL_LOAD, 200 (void *)(uintptr_t)1, NULL); 201 if (rv) { 202 return rv; 203 } 204 } 205 206 for (i = 0, mipskip = 0; i < nmodinfo; i++) { 207 if (mip[i] == &module_dummy) { 208 KASSERT(nmodinfo > 0); 209 nmodinfo--; 210 } 211 } 212 if (nmodinfo == 0) 213 return 0; 214 215 modp = kmem_zalloc(sizeof(*modp) * nmodinfo, KM_SLEEP); 216 for (i = 0, mipskip = 0; i < nmodinfo; i++) { 217 if (mip[i+mipskip] == &module_dummy) { 218 mipskip++; 219 continue; 220 } 221 modp[i] = module_newmodule(MODULE_SOURCE_KERNEL); 222 modp[i]->mod_info = mip[i+mipskip]; 223 } 224 kernconfig_lock(); 225 226 /* do this in three stages for error recovery and atomicity */ 227 228 /* first check for presence */ 229 for (i = 0; i < nmodinfo; i++) { 230 TAILQ_FOREACH(mod_iter, &module_builtins, mod_chain) { 231 if (strcmp(mod_iter->mod_info->mi_name, 232 modp[i]->mod_info->mi_name) == 0) 233 break; 234 } 235 if (mod_iter) { 236 rv = EEXIST; 237 goto out; 238 } 239 240 if (module_lookup(modp[i]->mod_info->mi_name) != NULL) { 241 rv = EEXIST; 242 goto out; 243 } 244 } 245 246 /* then add to list */ 247 for (i = 0; i < nmodinfo; i++) { 248 TAILQ_INSERT_TAIL(&module_builtins, modp[i], mod_chain); 249 module_builtinlist++; 250 } 251 252 /* finally, init (if required) */ 253 if (init) { 254 for (i = 0; i < nmodinfo; i++) { 255 rv = module_do_builtin(modp[i]->mod_info->mi_name, 256 NULL, NULL); 257 /* throw in the towel, recovery hard & not worth it */ 258 if (rv) 259 panic("builtin module \"%s\" init failed: %d", 260 modp[i]->mod_info->mi_name, rv); 261 } 262 } 263 264 out: 265 kernconfig_unlock(); 266 if (rv != 0) { 267 for (i = 0; i < nmodinfo; i++) { 268 if (modp[i]) 269 kmem_free(modp[i], sizeof(*modp[i])); 270 } 271 } 272 kmem_free(modp, sizeof(*modp) * nmodinfo); 273 return rv; 274 } 275 276 /* 277 * Optionally fini and remove builtin module from the kernel. 278 * Note: the module will now be unreachable except via mi && builtin_add. 279 */ 280 int 281 module_builtin_remove(modinfo_t *mi, bool fini) 282 { 283 struct module *mod; 284 int rv = 0; 285 286 if (fini) { 287 rv = kauth_authorize_system(kauth_cred_get(), 288 KAUTH_SYSTEM_MODULE, 0, (void *)(uintptr_t)MODCTL_UNLOAD, 289 NULL, NULL); 290 if (rv) 291 return rv; 292 293 kernconfig_lock(); 294 rv = module_do_unload(mi->mi_name, true); 295 if (rv) { 296 goto out; 297 } 298 } else { 299 kernconfig_lock(); 300 } 301 TAILQ_FOREACH(mod, &module_builtins, mod_chain) { 302 if (strcmp(mod->mod_info->mi_name, mi->mi_name) == 0) 303 break; 304 } 305 if (mod) { 306 TAILQ_REMOVE(&module_builtins, mod, mod_chain); 307 module_builtinlist--; 308 } else { 309 KASSERT(fini == false); 310 rv = ENOENT; 311 } 312 313 out: 314 kernconfig_unlock(); 315 return rv; 316 } 317 318 /* 319 * module_init: 320 * 321 * Initialize the module subsystem. 322 */ 323 void 324 module_init(void) 325 { 326 __link_set_decl(modules, modinfo_t); 327 extern struct vm_map *module_map; 328 modinfo_t *const *mip; 329 int rv; 330 331 if (module_map == NULL) { 332 module_map = kernel_map; 333 } 334 cv_init(&module_thread_cv, "mod_unld"); 335 mutex_init(&module_thread_lock, MUTEX_DEFAULT, IPL_NONE); 336 337 #ifdef MODULAR /* XXX */ 338 module_init_md(); 339 #endif 340 341 #if __NetBSD_Version__ / 1000000 % 100 == 99 /* -current */ 342 snprintf(module_base, sizeof(module_base), "/stand/%s/%s/modules", 343 machine, osrelease); 344 #else /* release */ 345 snprintf(module_base, sizeof(module_base), "/stand/%s/%d.%d/modules", 346 machine, __NetBSD_Version__ / 100000000, 347 __NetBSD_Version__ / 1000000 % 100); 348 #endif 349 350 module_listener = kauth_listen_scope(KAUTH_SCOPE_SYSTEM, 351 module_listener_cb, NULL); 352 353 __link_set_foreach(mip, modules) { 354 if ((rv = module_builtin_add(mip, 1, false) != 0)) 355 module_error("builtin %s failed: %d\n", 356 (*mip)->mi_name, rv); 357 } 358 359 sysctl_module_setup(); 360 } 361 362 /* 363 * module_start_unload_thread: 364 * 365 * Start the auto unload kthread. 366 */ 367 void 368 module_start_unload_thread(void) 369 { 370 int error; 371 372 error = kthread_create(PRI_VM, KTHREAD_MPSAFE, NULL, module_thread, 373 NULL, NULL, "modunload"); 374 if (error != 0) 375 panic("module_init: %d", error); 376 } 377 378 /* 379 * module_builtin_require_force 380 * 381 * Require MODCTL_MUST_FORCE to load any built-in modules that have 382 * not yet been initialized 383 */ 384 void 385 module_builtin_require_force(void) 386 { 387 module_t *mod; 388 389 kernconfig_lock(); 390 TAILQ_FOREACH(mod, &module_builtins, mod_chain) { 391 module_require_force(mod); 392 } 393 kernconfig_unlock(); 394 } 395 396 static struct sysctllog *module_sysctllog; 397 398 static void 399 sysctl_module_setup(void) 400 { 401 const struct sysctlnode *node = NULL; 402 403 sysctl_createv(&module_sysctllog, 0, NULL, NULL, 404 CTLFLAG_PERMANENT, 405 CTLTYPE_NODE, "kern", NULL, 406 NULL, 0, NULL, 0, 407 CTL_KERN, CTL_EOL); 408 sysctl_createv(&module_sysctllog, 0, NULL, &node, 409 CTLFLAG_PERMANENT, 410 CTLTYPE_NODE, "module", 411 SYSCTL_DESCR("Module options"), 412 NULL, 0, NULL, 0, 413 CTL_KERN, CTL_CREATE, CTL_EOL); 414 415 if (node == NULL) 416 return; 417 418 sysctl_createv(&module_sysctllog, 0, &node, NULL, 419 CTLFLAG_PERMANENT | CTLFLAG_READWRITE, 420 CTLTYPE_BOOL, "autoload", 421 SYSCTL_DESCR("Enable automatic load of modules"), 422 NULL, 0, &module_autoload_on, 0, 423 CTL_CREATE, CTL_EOL); 424 sysctl_createv(&module_sysctllog, 0, &node, NULL, 425 CTLFLAG_PERMANENT | CTLFLAG_READWRITE, 426 CTLTYPE_BOOL, "verbose", 427 SYSCTL_DESCR("Enable verbose output"), 428 NULL, 0, &module_verbose_on, 0, 429 CTL_CREATE, CTL_EOL); 430 } 431 432 /* 433 * module_init_class: 434 * 435 * Initialize all built-in and pre-loaded modules of the 436 * specified class. 437 */ 438 void 439 module_init_class(modclass_t class) 440 { 441 TAILQ_HEAD(, module) bi_fail = TAILQ_HEAD_INITIALIZER(bi_fail); 442 module_t *mod; 443 modinfo_t *mi; 444 445 kernconfig_lock(); 446 /* 447 * Builtins first. These will not depend on pre-loaded modules 448 * (because the kernel would not link). 449 */ 450 do { 451 TAILQ_FOREACH(mod, &module_builtins, mod_chain) { 452 mi = mod->mod_info; 453 if (class != MODULE_CLASS_ANY && class != mi->mi_class) 454 continue; 455 /* 456 * If initializing a builtin module fails, don't try 457 * to load it again. But keep it around and queue it 458 * on the builtins list after we're done with module 459 * init. Don't set it to MODFLG_MUST_FORCE in case a 460 * future attempt to initialize can be successful. 461 * (If the module has previously been set to 462 * MODFLG_MUST_FORCE, don't try to override that!) 463 */ 464 if (mod->mod_flags & MODFLG_MUST_FORCE || 465 module_do_builtin(mi->mi_name, NULL, NULL) != 0) { 466 TAILQ_REMOVE(&module_builtins, mod, mod_chain); 467 TAILQ_INSERT_TAIL(&bi_fail, mod, mod_chain); 468 } 469 break; 470 } 471 } while (mod != NULL); 472 473 /* 474 * Now preloaded modules. These will be pulled off the 475 * list as we call module_do_load(); 476 */ 477 do { 478 TAILQ_FOREACH(mod, &module_bootlist, mod_chain) { 479 mi = mod->mod_info; 480 if (class != MODULE_CLASS_ANY && class != mi->mi_class) 481 continue; 482 module_do_load(mi->mi_name, false, 0, NULL, NULL, 483 class, false); 484 break; 485 } 486 } while (mod != NULL); 487 488 /* return failed builtin modules to builtin list */ 489 while ((mod = TAILQ_FIRST(&bi_fail)) != NULL) { 490 TAILQ_REMOVE(&bi_fail, mod, mod_chain); 491 TAILQ_INSERT_TAIL(&module_builtins, mod, mod_chain); 492 } 493 494 kernconfig_unlock(); 495 } 496 497 /* 498 * module_compatible: 499 * 500 * Return true if the two supplied kernel versions are said to 501 * have the same binary interface for kernel code. The entire 502 * version is signficant for the development tree (-current), 503 * major and minor versions are significant for official 504 * releases of the system. 505 */ 506 bool 507 module_compatible(int v1, int v2) 508 { 509 510 #if __NetBSD_Version__ / 1000000 % 100 == 99 /* -current */ 511 return v1 == v2; 512 #else /* release */ 513 return abs(v1 - v2) < 10000; 514 #endif 515 } 516 517 /* 518 * module_load: 519 * 520 * Load a single module from the file system. 521 */ 522 int 523 module_load(const char *filename, int flags, prop_dictionary_t props, 524 modclass_t class) 525 { 526 int error; 527 528 /* Authorize. */ 529 error = kauth_authorize_system(kauth_cred_get(), KAUTH_SYSTEM_MODULE, 530 0, (void *)(uintptr_t)MODCTL_LOAD, NULL, NULL); 531 if (error != 0) { 532 return error; 533 } 534 535 kernconfig_lock(); 536 error = module_do_load(filename, false, flags, props, NULL, class, 537 false); 538 kernconfig_unlock(); 539 540 return error; 541 } 542 543 /* 544 * module_autoload: 545 * 546 * Load a single module from the file system, system initiated. 547 */ 548 int 549 module_autoload(const char *filename, modclass_t class) 550 { 551 int error; 552 553 kernconfig_lock(); 554 555 /* Nothing if the user has disabled it. */ 556 if (!module_autoload_on) { 557 kernconfig_unlock(); 558 return EPERM; 559 } 560 561 /* Disallow path separators and magic symlinks. */ 562 if (strchr(filename, '/') != NULL || strchr(filename, '@') != NULL || 563 strchr(filename, '.') != NULL) { 564 kernconfig_unlock(); 565 return EPERM; 566 } 567 568 /* Authorize. */ 569 error = kauth_authorize_system(kauth_cred_get(), KAUTH_SYSTEM_MODULE, 570 0, (void *)(uintptr_t)MODCTL_LOAD, (void *)(uintptr_t)1, NULL); 571 572 if (error == 0) 573 error = module_do_load(filename, false, 0, NULL, NULL, class, 574 true); 575 576 kernconfig_unlock(); 577 return error; 578 } 579 580 /* 581 * module_unload: 582 * 583 * Find and unload a module by name. 584 */ 585 int 586 module_unload(const char *name) 587 { 588 int error; 589 590 /* Authorize. */ 591 error = kauth_authorize_system(kauth_cred_get(), KAUTH_SYSTEM_MODULE, 592 0, (void *)(uintptr_t)MODCTL_UNLOAD, NULL, NULL); 593 if (error != 0) { 594 return error; 595 } 596 597 kernconfig_lock(); 598 error = module_do_unload(name, true); 599 kernconfig_unlock(); 600 601 return error; 602 } 603 604 /* 605 * module_lookup: 606 * 607 * Look up a module by name. 608 */ 609 module_t * 610 module_lookup(const char *name) 611 { 612 module_t *mod; 613 614 KASSERT(kernconfig_is_held()); 615 616 TAILQ_FOREACH(mod, &module_list, mod_chain) { 617 if (strcmp(mod->mod_info->mi_name, name) == 0) { 618 break; 619 } 620 } 621 622 return mod; 623 } 624 625 /* 626 * module_hold: 627 * 628 * Add a single reference to a module. It's the caller's 629 * responsibility to ensure that the reference is dropped 630 * later. 631 */ 632 int 633 module_hold(const char *name) 634 { 635 module_t *mod; 636 637 kernconfig_lock(); 638 mod = module_lookup(name); 639 if (mod == NULL) { 640 kernconfig_unlock(); 641 return ENOENT; 642 } 643 mod->mod_refcnt++; 644 kernconfig_unlock(); 645 646 return 0; 647 } 648 649 /* 650 * module_rele: 651 * 652 * Release a reference acquired with module_hold(). 653 */ 654 void 655 module_rele(const char *name) 656 { 657 module_t *mod; 658 659 kernconfig_lock(); 660 mod = module_lookup(name); 661 if (mod == NULL) { 662 kernconfig_unlock(); 663 panic("module_rele: gone"); 664 } 665 mod->mod_refcnt--; 666 kernconfig_unlock(); 667 } 668 669 /* 670 * module_enqueue: 671 * 672 * Put a module onto the global list and update counters. 673 */ 674 void 675 module_enqueue(module_t *mod) 676 { 677 int i; 678 679 KASSERT(kernconfig_is_held()); 680 681 /* 682 * If there are requisite modules, put at the head of the queue. 683 * This is so that autounload can unload requisite modules with 684 * only one pass through the queue. 685 */ 686 if (mod->mod_nrequired) { 687 TAILQ_INSERT_HEAD(&module_list, mod, mod_chain); 688 689 /* Add references to the requisite modules. */ 690 for (i = 0; i < mod->mod_nrequired; i++) { 691 KASSERT(mod->mod_required[i] != NULL); 692 mod->mod_required[i]->mod_refcnt++; 693 } 694 } else { 695 TAILQ_INSERT_TAIL(&module_list, mod, mod_chain); 696 } 697 module_count++; 698 module_gen++; 699 } 700 701 /* 702 * module_do_builtin: 703 * 704 * Initialize a module from the list of modules that are 705 * already linked into the kernel. 706 */ 707 static int 708 module_do_builtin(const char *name, module_t **modp, prop_dictionary_t props) 709 { 710 const char *p, *s; 711 char buf[MAXMODNAME]; 712 modinfo_t *mi = NULL; 713 module_t *mod, *mod2, *mod_loaded, *prev_active; 714 size_t len; 715 int error; 716 717 KASSERT(kernconfig_is_held()); 718 719 /* 720 * Search the list to see if we have a module by this name. 721 */ 722 TAILQ_FOREACH(mod, &module_builtins, mod_chain) { 723 if (strcmp(mod->mod_info->mi_name, name) == 0) { 724 mi = mod->mod_info; 725 break; 726 } 727 } 728 729 /* 730 * Check to see if already loaded. This might happen if we 731 * were already loaded as a dependency. 732 */ 733 if ((mod_loaded = module_lookup(name)) != NULL) { 734 KASSERT(mod == NULL); 735 if (modp) 736 *modp = mod_loaded; 737 return 0; 738 } 739 740 /* Note! This is from TAILQ, not immediate above */ 741 if (mi == NULL) { 742 /* 743 * XXX: We'd like to panic here, but currently in some 744 * cases (such as nfsserver + nfs), the dependee can be 745 * succesfully linked without the dependencies. 746 */ 747 module_error("can't find builtin dependency `%s'", name); 748 return ENOENT; 749 } 750 751 /* 752 * Initialize pre-requisites. 753 */ 754 if (mi->mi_required != NULL) { 755 for (s = mi->mi_required; *s != '\0'; s = p) { 756 if (*s == ',') 757 s++; 758 p = s; 759 while (*p != '\0' && *p != ',') 760 p++; 761 len = min(p - s + 1, sizeof(buf)); 762 strlcpy(buf, s, len); 763 if (buf[0] == '\0') 764 break; 765 if (mod->mod_nrequired == MAXMODDEPS - 1) { 766 module_error("too many required modules"); 767 return EINVAL; 768 } 769 error = module_do_builtin(buf, &mod2, NULL); 770 if (error != 0) { 771 return error; 772 } 773 mod->mod_required[mod->mod_nrequired++] = mod2; 774 } 775 } 776 777 /* 778 * Try to initialize the module. 779 */ 780 prev_active = module_active; 781 module_active = mod; 782 error = (*mi->mi_modcmd)(MODULE_CMD_INIT, props); 783 module_active = prev_active; 784 if (error != 0) { 785 module_error("builtin module `%s' " 786 "failed to init", mi->mi_name); 787 return error; 788 } 789 790 /* load always succeeds after this point */ 791 792 TAILQ_REMOVE(&module_builtins, mod, mod_chain); 793 module_builtinlist--; 794 if (modp != NULL) { 795 *modp = mod; 796 } 797 if (mi->mi_class == MODULE_CLASS_SECMODEL) 798 secmodel_register(); 799 module_enqueue(mod); 800 return 0; 801 } 802 803 /* 804 * module_do_load: 805 * 806 * Helper routine: load a module from the file system, or one 807 * pushed by the boot loader. 808 */ 809 static int 810 module_do_load(const char *name, bool isdep, int flags, 811 prop_dictionary_t props, module_t **modp, modclass_t class, 812 bool autoload) 813 { 814 #define MODULE_MAX_DEPTH 6 815 816 TAILQ_HEAD(pending_t, module); 817 static int depth = 0; 818 static struct pending_t *pending_lists[MODULE_MAX_DEPTH]; 819 struct pending_t *pending; 820 struct pending_t new_pending = TAILQ_HEAD_INITIALIZER(new_pending); 821 modinfo_t *mi; 822 module_t *mod, *mod2, *prev_active; 823 prop_dictionary_t filedict; 824 char buf[MAXMODNAME]; 825 const char *s, *p; 826 int error; 827 size_t len; 828 829 KASSERT(kernconfig_is_held()); 830 831 filedict = NULL; 832 error = 0; 833 834 /* 835 * Avoid recursing too far. 836 */ 837 if (++depth > MODULE_MAX_DEPTH) { 838 module_error("recursion too deep"); 839 depth--; 840 return EMLINK; 841 } 842 843 /* 844 * Set up the pending list for this depth. If this is a 845 * recursive entry, then use same list as for outer call, 846 * else use the locally allocated list. In either case, 847 * remember which one we're using. 848 */ 849 if (isdep) { 850 KASSERT(depth > 1); 851 pending = pending_lists[depth - 2]; 852 } else 853 pending = &new_pending; 854 pending_lists[depth - 1] = pending; 855 856 /* 857 * Search the list of disabled builtins first. 858 */ 859 TAILQ_FOREACH(mod, &module_builtins, mod_chain) { 860 if (strcmp(mod->mod_info->mi_name, name) == 0) { 861 break; 862 } 863 } 864 if (mod) { 865 if ((mod->mod_flags & MODFLG_MUST_FORCE) && 866 (flags & MODCTL_LOAD_FORCE) == 0) { 867 if (!autoload) { 868 module_error("use -f to reinstate " 869 "builtin module \"%s\"", name); 870 } 871 depth--; 872 return EPERM; 873 } else { 874 error = module_do_builtin(name, NULL, props); 875 depth--; 876 return error; 877 } 878 } 879 880 /* 881 * Load the module and link. Before going to the file system, 882 * scan the list of modules loaded by the boot loader. 883 */ 884 TAILQ_FOREACH(mod, &module_bootlist, mod_chain) { 885 if (strcmp(mod->mod_info->mi_name, name) == 0) { 886 TAILQ_REMOVE(&module_bootlist, mod, mod_chain); 887 break; 888 } 889 } 890 if (mod != NULL) { 891 TAILQ_INSERT_TAIL(pending, mod, mod_chain); 892 } else { 893 /* 894 * If a requisite module, check to see if it is 895 * already present. 896 */ 897 if (isdep) { 898 mod = module_lookup(name); 899 if (mod != NULL) { 900 if (modp != NULL) { 901 *modp = mod; 902 } 903 depth--; 904 return 0; 905 } 906 } 907 mod = module_newmodule(MODULE_SOURCE_FILESYS); 908 if (mod == NULL) { 909 module_error("out of memory for `%s'", name); 910 depth--; 911 return ENOMEM; 912 } 913 914 error = module_load_vfs_vec(name, flags, autoload, mod, 915 &filedict); 916 if (error != 0) { 917 kmem_free(mod, sizeof(*mod)); 918 depth--; 919 return error; 920 } 921 TAILQ_INSERT_TAIL(pending, mod, mod_chain); 922 923 error = module_fetch_info(mod); 924 if (error != 0) { 925 module_error("cannot fetch module info for `%s'", 926 name); 927 goto fail; 928 } 929 } 930 931 /* 932 * Check compatibility. 933 */ 934 mi = mod->mod_info; 935 if (strlen(mi->mi_name) >= MAXMODNAME) { 936 error = EINVAL; 937 module_error("module name `%s' too long", mi->mi_name); 938 goto fail; 939 } 940 if (!module_compatible(mi->mi_version, __NetBSD_Version__)) { 941 module_error("module built for `%d', system `%d'", 942 mi->mi_version, __NetBSD_Version__); 943 if ((flags & MODCTL_LOAD_FORCE) != 0) { 944 module_error("forced load, system may be unstable"); 945 } else { 946 error = EPROGMISMATCH; 947 goto fail; 948 } 949 } 950 951 /* 952 * If a specific kind of module was requested, ensure that we have 953 * a match. 954 */ 955 if (class != MODULE_CLASS_ANY && class != mi->mi_class) { 956 module_print("incompatible module class for `%s' (%d != %d)", 957 name, class, mi->mi_class); 958 error = ENOENT; 959 goto fail; 960 } 961 962 /* 963 * If loading a dependency, `name' is a plain module name. 964 * The name must match. 965 */ 966 if (isdep && strcmp(mi->mi_name, name) != 0) { 967 module_error("dependency name mismatch (`%s' != `%s')", 968 name, mi->mi_name); 969 error = ENOENT; 970 goto fail; 971 } 972 973 /* 974 * Check to see if the module is already loaded. If so, we may 975 * have been recursively called to handle a dependency, so be sure 976 * to set modp. 977 */ 978 if ((mod2 = module_lookup(mi->mi_name)) != NULL) { 979 if (modp != NULL) 980 *modp = mod2; 981 module_print("module `%s' already loaded", mi->mi_name); 982 error = EEXIST; 983 goto fail; 984 } 985 986 /* 987 * Block circular dependencies. 988 */ 989 TAILQ_FOREACH(mod2, pending, mod_chain) { 990 if (mod == mod2) { 991 continue; 992 } 993 if (strcmp(mod2->mod_info->mi_name, mi->mi_name) == 0) { 994 error = EDEADLK; 995 module_error("circular dependency detected for `%s'", 996 mi->mi_name); 997 goto fail; 998 } 999 } 1000 1001 /* 1002 * Now try to load any requisite modules. 1003 */ 1004 if (mi->mi_required != NULL) { 1005 for (s = mi->mi_required; *s != '\0'; s = p) { 1006 if (*s == ',') 1007 s++; 1008 p = s; 1009 while (*p != '\0' && *p != ',') 1010 p++; 1011 len = p - s + 1; 1012 if (len >= MAXMODNAME) { 1013 error = EINVAL; 1014 module_error("required module name `%s'" 1015 " too long", mi->mi_required); 1016 goto fail; 1017 } 1018 strlcpy(buf, s, len); 1019 if (buf[0] == '\0') 1020 break; 1021 if (mod->mod_nrequired == MAXMODDEPS - 1) { 1022 error = EINVAL; 1023 module_error("too many required modules (%d)", 1024 mod->mod_nrequired); 1025 goto fail; 1026 } 1027 if (strcmp(buf, mi->mi_name) == 0) { 1028 error = EDEADLK; 1029 module_error("self-dependency detected for " 1030 "`%s'", mi->mi_name); 1031 goto fail; 1032 } 1033 error = module_do_load(buf, true, flags, NULL, 1034 &mod->mod_required[mod->mod_nrequired++], 1035 MODULE_CLASS_ANY, true); 1036 if (error != 0) 1037 goto fail; 1038 } 1039 } 1040 1041 /* 1042 * We loaded all needed modules successfully: perform global 1043 * relocations and initialize. 1044 */ 1045 error = kobj_affix(mod->mod_kobj, mi->mi_name); 1046 if (error != 0) { 1047 /* Cannot touch 'mi' as the module is now gone. */ 1048 module_error("unable to affix module `%s'", name); 1049 goto fail2; 1050 } 1051 1052 if (filedict) { 1053 if (!module_merge_dicts(filedict, props)) { 1054 module_error("module properties failed"); 1055 error = EINVAL; 1056 goto fail; 1057 } 1058 } 1059 prev_active = module_active; 1060 module_active = mod; 1061 error = (*mi->mi_modcmd)(MODULE_CMD_INIT, filedict ? filedict : props); 1062 module_active = prev_active; 1063 if (filedict) { 1064 prop_object_release(filedict); 1065 filedict = NULL; 1066 } 1067 if (error != 0) { 1068 module_error("modcmd function returned error %d for `%s'", 1069 error, mi->mi_name); 1070 goto fail; 1071 } 1072 1073 if (mi->mi_class == MODULE_CLASS_SECMODEL) 1074 secmodel_register(); 1075 1076 /* 1077 * Good, the module loaded successfully. Put it onto the 1078 * list and add references to its requisite modules. 1079 */ 1080 TAILQ_REMOVE(pending, mod, mod_chain); 1081 module_enqueue(mod); 1082 if (modp != NULL) { 1083 *modp = mod; 1084 } 1085 if (autoload) { 1086 /* 1087 * Arrange to try unloading the module after 1088 * a short delay. 1089 */ 1090 mod->mod_autotime = time_second + module_autotime; 1091 module_thread_kick(); 1092 } 1093 depth--; 1094 return 0; 1095 1096 fail: 1097 kobj_unload(mod->mod_kobj); 1098 fail2: 1099 if (filedict != NULL) { 1100 prop_object_release(filedict); 1101 filedict = NULL; 1102 } 1103 TAILQ_REMOVE(pending, mod, mod_chain); 1104 kmem_free(mod, sizeof(*mod)); 1105 depth--; 1106 return error; 1107 } 1108 1109 /* 1110 * module_do_unload: 1111 * 1112 * Helper routine: do the dirty work of unloading a module. 1113 */ 1114 static int 1115 module_do_unload(const char *name, bool load_requires_force) 1116 { 1117 module_t *mod, *prev_active; 1118 int error; 1119 u_int i; 1120 1121 KASSERT(kernconfig_is_held()); 1122 1123 mod = module_lookup(name); 1124 if (mod == NULL) { 1125 module_error("module `%s' not found", name); 1126 return ENOENT; 1127 } 1128 if (mod->mod_refcnt != 0) { 1129 module_print("module `%s' busy", name); 1130 return EBUSY; 1131 } 1132 prev_active = module_active; 1133 module_active = mod; 1134 error = (*mod->mod_info->mi_modcmd)(MODULE_CMD_FINI, NULL); 1135 module_active = prev_active; 1136 if (error != 0) { 1137 module_print("cannot unload module `%s' error=%d", name, 1138 error); 1139 return error; 1140 } 1141 if (mod->mod_info->mi_class == MODULE_CLASS_SECMODEL) 1142 secmodel_deregister(); 1143 module_count--; 1144 TAILQ_REMOVE(&module_list, mod, mod_chain); 1145 for (i = 0; i < mod->mod_nrequired; i++) { 1146 mod->mod_required[i]->mod_refcnt--; 1147 } 1148 if (mod->mod_kobj != NULL) { 1149 kobj_unload(mod->mod_kobj); 1150 } 1151 if (mod->mod_source == MODULE_SOURCE_KERNEL) { 1152 mod->mod_nrequired = 0; /* will be re-parsed */ 1153 if (load_requires_force) 1154 module_require_force(mod); 1155 TAILQ_INSERT_TAIL(&module_builtins, mod, mod_chain); 1156 module_builtinlist++; 1157 } else { 1158 kmem_free(mod, sizeof(*mod)); 1159 } 1160 module_gen++; 1161 1162 return 0; 1163 } 1164 1165 /* 1166 * module_prime: 1167 * 1168 * Push a module loaded by the bootloader onto our internal 1169 * list. 1170 */ 1171 int 1172 module_prime(void *base, size_t size) 1173 { 1174 module_t *mod; 1175 int error; 1176 1177 mod = module_newmodule(MODULE_SOURCE_BOOT); 1178 if (mod == NULL) { 1179 return ENOMEM; 1180 } 1181 1182 error = kobj_load_mem(&mod->mod_kobj, base, size); 1183 if (error != 0) { 1184 kmem_free(mod, sizeof(*mod)); 1185 module_error("unable to load object pushed by boot loader"); 1186 return error; 1187 } 1188 error = module_fetch_info(mod); 1189 if (error != 0) { 1190 kobj_unload(mod->mod_kobj); 1191 kmem_free(mod, sizeof(*mod)); 1192 module_error("unable to load object pushed by boot loader"); 1193 return error; 1194 } 1195 1196 TAILQ_INSERT_TAIL(&module_bootlist, mod, mod_chain); 1197 1198 return 0; 1199 } 1200 1201 /* 1202 * module_fetch_into: 1203 * 1204 * Fetch modinfo record from a loaded module. 1205 */ 1206 static int 1207 module_fetch_info(module_t *mod) 1208 { 1209 int error; 1210 void *addr; 1211 size_t size; 1212 1213 /* 1214 * Find module info record and check compatibility. 1215 */ 1216 error = kobj_find_section(mod->mod_kobj, "link_set_modules", 1217 &addr, &size); 1218 if (error != 0) { 1219 module_error("`link_set_modules' section not present"); 1220 return error; 1221 } 1222 if (size != sizeof(modinfo_t **)) { 1223 module_error("`link_set_modules' section wrong size"); 1224 return error; 1225 } 1226 mod->mod_info = *(modinfo_t **)addr; 1227 1228 return 0; 1229 } 1230 1231 /* 1232 * module_find_section: 1233 * 1234 * Allows a module that is being initialized to look up a section 1235 * within its ELF object. 1236 */ 1237 int 1238 module_find_section(const char *name, void **addr, size_t *size) 1239 { 1240 1241 KASSERT(kernconfig_is_held()); 1242 KASSERT(module_active != NULL); 1243 1244 return kobj_find_section(module_active->mod_kobj, name, addr, size); 1245 } 1246 1247 /* 1248 * module_thread: 1249 * 1250 * Automatically unload modules. We try once to unload autoloaded 1251 * modules after module_autotime seconds. If the system is under 1252 * severe memory pressure, we'll try unloading all modules. 1253 */ 1254 static void 1255 module_thread(void *cookie) 1256 { 1257 module_t *mod, *next; 1258 modinfo_t *mi; 1259 int error; 1260 1261 for (;;) { 1262 kernconfig_lock(); 1263 for (mod = TAILQ_FIRST(&module_list); mod != NULL; mod = next) { 1264 next = TAILQ_NEXT(mod, mod_chain); 1265 if (mod->mod_source == MODULE_SOURCE_KERNEL) 1266 continue; 1267 if (uvmexp.free < uvmexp.freemin) { 1268 module_thread_ticks = hz; 1269 } else if (mod->mod_autotime == 0) { 1270 continue; 1271 } else if (time_second < mod->mod_autotime) { 1272 module_thread_ticks = hz; 1273 continue; 1274 } else { 1275 mod->mod_autotime = 0; 1276 } 1277 /* 1278 * If this module wants to avoid autounload then 1279 * skip it. Some modules can ping-pong in and out 1280 * because their use is transient but often. 1281 * Example: exec_script. 1282 */ 1283 mi = mod->mod_info; 1284 error = (*mi->mi_modcmd)(MODULE_CMD_AUTOUNLOAD, NULL); 1285 if (error == 0 || error == ENOTTY) { 1286 (void)module_do_unload(mi->mi_name, false); 1287 } 1288 } 1289 kernconfig_unlock(); 1290 1291 mutex_enter(&module_thread_lock); 1292 (void)cv_timedwait(&module_thread_cv, &module_thread_lock, 1293 module_thread_ticks); 1294 module_thread_ticks = 0; 1295 mutex_exit(&module_thread_lock); 1296 } 1297 } 1298 1299 /* 1300 * module_thread: 1301 * 1302 * Kick the module thread into action, perhaps because the 1303 * system is low on memory. 1304 */ 1305 void 1306 module_thread_kick(void) 1307 { 1308 1309 mutex_enter(&module_thread_lock); 1310 module_thread_ticks = hz; 1311 cv_broadcast(&module_thread_cv); 1312 mutex_exit(&module_thread_lock); 1313 } 1314 1315 #ifdef DDB 1316 /* 1317 * module_whatis: 1318 * 1319 * Helper routine for DDB. 1320 */ 1321 void 1322 module_whatis(uintptr_t addr, void (*pr)(const char *, ...)) 1323 { 1324 module_t *mod; 1325 size_t msize; 1326 vaddr_t maddr; 1327 1328 TAILQ_FOREACH(mod, &module_list, mod_chain) { 1329 if (mod->mod_kobj == NULL) { 1330 continue; 1331 } 1332 if (kobj_stat(mod->mod_kobj, &maddr, &msize) != 0) 1333 continue; 1334 if (addr < maddr || addr >= maddr + msize) { 1335 continue; 1336 } 1337 (*pr)("%p is %p+%zu, in kernel module `%s'\n", 1338 (void *)addr, (void *)maddr, 1339 (size_t)(addr - maddr), mod->mod_info->mi_name); 1340 } 1341 } 1342 1343 /* 1344 * module_print_list: 1345 * 1346 * Helper routine for DDB. 1347 */ 1348 void 1349 module_print_list(void (*pr)(const char *, ...)) 1350 { 1351 const char *src; 1352 module_t *mod; 1353 size_t msize; 1354 vaddr_t maddr; 1355 1356 (*pr)("%16s %16s %8s %8s\n", "NAME", "TEXT/DATA", "SIZE", "SOURCE"); 1357 1358 TAILQ_FOREACH(mod, &module_list, mod_chain) { 1359 switch (mod->mod_source) { 1360 case MODULE_SOURCE_KERNEL: 1361 src = "builtin"; 1362 break; 1363 case MODULE_SOURCE_FILESYS: 1364 src = "filesys"; 1365 break; 1366 case MODULE_SOURCE_BOOT: 1367 src = "boot"; 1368 break; 1369 default: 1370 src = "unknown"; 1371 break; 1372 } 1373 if (mod->mod_kobj == NULL) { 1374 maddr = 0; 1375 msize = 0; 1376 } else if (kobj_stat(mod->mod_kobj, &maddr, &msize) != 0) 1377 continue; 1378 (*pr)("%16s %16lx %8ld %8s\n", mod->mod_info->mi_name, 1379 (long)maddr, (long)msize, src); 1380 } 1381 } 1382 #endif /* DDB */ 1383 1384 static bool 1385 module_merge_dicts(prop_dictionary_t existing_dict, 1386 const prop_dictionary_t new_dict) 1387 { 1388 prop_dictionary_keysym_t props_keysym; 1389 prop_object_iterator_t props_iter; 1390 prop_object_t props_obj; 1391 const char *props_key; 1392 bool error; 1393 1394 if (new_dict == NULL) { /* nothing to merge */ 1395 return true; 1396 } 1397 1398 error = false; 1399 props_iter = prop_dictionary_iterator(new_dict); 1400 if (props_iter == NULL) { 1401 return false; 1402 } 1403 1404 while ((props_obj = prop_object_iterator_next(props_iter)) != NULL) { 1405 props_keysym = (prop_dictionary_keysym_t)props_obj; 1406 props_key = prop_dictionary_keysym_cstring_nocopy(props_keysym); 1407 props_obj = prop_dictionary_get_keysym(new_dict, props_keysym); 1408 if ((props_obj == NULL) || !prop_dictionary_set(existing_dict, 1409 props_key, props_obj)) { 1410 error = true; 1411 goto out; 1412 } 1413 } 1414 error = false; 1415 1416 out: 1417 prop_object_iterator_release(props_iter); 1418 1419 return !error; 1420 } 1421