1 /* $NetBSD: kern_module.c,v 1.65 2010/05/02 11:01:03 pooka 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 1.65 2010/05/02 11:01:03 pooka 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/kauth.h> 55 #include <sys/kthread.h> 56 #include <sys/sysctl.h> 57 #include <sys/lock.h> 58 59 #include <uvm/uvm_extern.h> 60 61 #include <machine/stdarg.h> 62 63 struct vm_map *module_map; 64 char module_base[MODULE_BASE_SIZE]; 65 66 struct modlist module_list = TAILQ_HEAD_INITIALIZER(module_list); 67 struct modlist module_builtins = TAILQ_HEAD_INITIALIZER(module_builtins); 68 static struct modlist module_bootlist = TAILQ_HEAD_INITIALIZER(module_bootlist); 69 70 static module_t *module_active; 71 static int module_verbose_on; 72 static int module_autoload_on = 1; 73 u_int module_count; 74 u_int module_builtinlist; 75 kmutex_t module_lock; 76 u_int module_autotime = 10; 77 u_int module_gen = 1; 78 static kcondvar_t module_thread_cv; 79 static kmutex_t module_thread_lock; 80 static int module_thread_ticks; 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 int module_do_load(const char *, bool, int, prop_dictionary_t, 89 module_t **, modclass_t class, bool); 90 static int module_do_unload(const char *); 91 static int module_do_builtin(const char *, module_t **); 92 static int module_fetch_info(module_t *); 93 static void module_thread(void *); 94 95 static module_t *module_lookup(const char *); 96 static void module_enqueue(module_t *); 97 98 static bool module_merge_dicts(prop_dictionary_t, const prop_dictionary_t); 99 100 int module_eopnotsupp(void); 101 102 int 103 module_eopnotsupp(void) 104 { 105 106 return EOPNOTSUPP; 107 } 108 __weak_alias(module_load_vfs,module_eopnotsupp); 109 110 /* 111 * module_error: 112 * 113 * Utility function: log an error. 114 */ 115 void 116 module_error(const char *fmt, ...) 117 { 118 va_list ap; 119 120 va_start(ap, fmt); 121 printf("WARNING: module error: "); 122 vprintf(fmt, ap); 123 printf("\n"); 124 va_end(ap); 125 } 126 127 /* 128 * module_print: 129 * 130 * Utility function: log verbose output. 131 */ 132 void 133 module_print(const char *fmt, ...) 134 { 135 va_list ap; 136 137 if (module_verbose_on) { 138 va_start(ap, fmt); 139 printf("DEBUG: module: "); 140 vprintf(fmt, ap); 141 printf("\n"); 142 va_end(ap); 143 } 144 } 145 146 static int 147 module_listener_cb(kauth_cred_t cred, kauth_action_t action, void *cookie, 148 void *arg0, void *arg1, void *arg2, void *arg3) 149 { 150 int result; 151 152 result = KAUTH_RESULT_DEFER; 153 154 if (action != KAUTH_SYSTEM_MODULE) 155 return result; 156 157 if ((uintptr_t)arg2 != 0) /* autoload */ 158 result = KAUTH_RESULT_ALLOW; 159 160 return result; 161 } 162 163 /* 164 * Add modules to the builtin list. This can done at boottime or 165 * at runtime if the module is linked into the kernel with an 166 * external linker. All or none of the input will be handled. 167 * Optionally, the modules can be initialized. If they are not 168 * initialized, module_init_class() or module_load() can be used 169 * later, but these are not guaranteed to give atomic results. 170 */ 171 int 172 module_builtin_add(modinfo_t *const *mip, size_t nmodinfo, bool init) 173 { 174 struct module **modp = NULL, *mod_iter; 175 int rv = 0, i, mipskip; 176 177 if (init) { 178 rv = kauth_authorize_system(kauth_cred_get(), 179 KAUTH_SYSTEM_MODULE, 0, (void *)(uintptr_t)MODCTL_LOAD, 180 (void *)(uintptr_t)1, NULL); 181 if (rv) { 182 return rv; 183 } 184 } 185 186 for (i = 0, mipskip = 0; i < nmodinfo; i++) { 187 if (mip[i] == &module_dummy) { 188 KASSERT(nmodinfo > 0); 189 nmodinfo--; 190 } 191 } 192 if (nmodinfo == 0) 193 return 0; 194 195 modp = kmem_zalloc(sizeof(*modp) * nmodinfo, KM_SLEEP); 196 for (i = 0, mipskip = 0; i < nmodinfo; i++) { 197 if (mip[i+mipskip] == &module_dummy) { 198 mipskip++; 199 continue; 200 } 201 modp[i] = kmem_zalloc(sizeof(*modp[i]), KM_SLEEP); 202 modp[i]->mod_info = mip[i+mipskip]; 203 modp[i]->mod_source = MODULE_SOURCE_KERNEL; 204 } 205 mutex_enter(&module_lock); 206 207 /* do this in three stages for error recovery and atomicity */ 208 209 /* first check for presence */ 210 for (i = 0; i < nmodinfo; i++) { 211 TAILQ_FOREACH(mod_iter, &module_builtins, mod_chain) { 212 if (strcmp(mod_iter->mod_info->mi_name, 213 modp[i]->mod_info->mi_name) == 0) 214 break; 215 } 216 if (mod_iter) { 217 rv = EEXIST; 218 goto out; 219 } 220 221 if (module_lookup(modp[i]->mod_info->mi_name) != NULL) { 222 rv = EEXIST; 223 goto out; 224 } 225 } 226 227 /* then add to list */ 228 for (i = 0; i < nmodinfo; i++) { 229 TAILQ_INSERT_TAIL(&module_builtins, modp[i], mod_chain); 230 module_builtinlist++; 231 } 232 233 /* finally, init (if required) */ 234 if (init) { 235 for (i = 0; i < nmodinfo; i++) { 236 rv = module_do_builtin(modp[i]->mod_info->mi_name,NULL); 237 /* throw in the towel, recovery hard & not worth it */ 238 if (rv) 239 panic("builtin module \"%s\" init failed: %d", 240 modp[i]->mod_info->mi_name, rv); 241 } 242 } 243 244 out: 245 mutex_exit(&module_lock); 246 if (rv != 0) { 247 for (i = 0; i < nmodinfo; i++) { 248 if (modp[i]) 249 kmem_free(modp[i], sizeof(*modp[i])); 250 } 251 } 252 kmem_free(modp, sizeof(*modp) * nmodinfo); 253 return rv; 254 } 255 256 /* 257 * Optionally fini and remove builtin module from the kernel. 258 * Note: the module will now be unreachable except via mi && builtin_add. 259 */ 260 int 261 module_builtin_remove(modinfo_t *mi, bool fini) 262 { 263 struct module *mod; 264 int rv = 0; 265 266 if (fini) { 267 rv = kauth_authorize_system(kauth_cred_get(), 268 KAUTH_SYSTEM_MODULE, 0, (void *)(uintptr_t)MODCTL_UNLOAD, 269 NULL, NULL); 270 if (rv) 271 return rv; 272 273 mutex_enter(&module_lock); 274 rv = module_do_unload(mi->mi_name); 275 if (rv) { 276 goto out; 277 } 278 } else { 279 mutex_enter(&module_lock); 280 } 281 TAILQ_FOREACH(mod, &module_builtins, mod_chain) { 282 if (strcmp(mod->mod_info->mi_name, mi->mi_name) == 0) 283 break; 284 } 285 if (mod) { 286 TAILQ_REMOVE(&module_builtins, mod, mod_chain); 287 module_builtinlist--; 288 } else { 289 KASSERT(fini == false); 290 rv = ENOENT; 291 } 292 293 out: 294 mutex_exit(&module_lock); 295 return rv; 296 } 297 298 /* 299 * module_init: 300 * 301 * Initialize the module subsystem. 302 */ 303 void 304 module_init(void) 305 { 306 __link_set_decl(modules, modinfo_t); 307 extern struct vm_map *module_map; 308 modinfo_t *const *mip; 309 int rv; 310 311 if (module_map == NULL) { 312 module_map = kernel_map; 313 } 314 mutex_init(&module_lock, MUTEX_DEFAULT, IPL_NONE); 315 cv_init(&module_thread_cv, "modunload"); 316 mutex_init(&module_thread_lock, MUTEX_DEFAULT, IPL_NONE); 317 #ifdef MODULAR /* XXX */ 318 module_init_md(); 319 #endif 320 321 #if __NetBSD_Version__ / 1000000 % 100 == 99 /* -current */ 322 snprintf(module_base, sizeof(module_base), "/stand/%s/%s/modules", 323 machine, osrelease); 324 #else /* release */ 325 snprintf(module_base, sizeof(module_base), "/stand/%s/%d.%d/modules", 326 machine, __NetBSD_Version__ / 100000000, 327 __NetBSD_Version__ / 1000000 % 100); 328 #endif 329 330 module_listener = kauth_listen_scope(KAUTH_SCOPE_SYSTEM, 331 module_listener_cb, NULL); 332 333 __link_set_foreach(mip, modules) { 334 if ((rv = module_builtin_add(mip, 1, false) != 0)) 335 module_error("builtin %s failed: %d\n", 336 (*mip)->mi_name, rv); 337 } 338 } 339 340 /* 341 * module_init2: 342 * 343 * Start the auto unload kthread. 344 */ 345 void 346 module_init2(void) 347 { 348 int error; 349 350 error = kthread_create(PRI_VM, KTHREAD_MPSAFE, NULL, module_thread, 351 NULL, NULL, "modunload"); 352 if (error != 0) 353 panic("module_init: %d", error); 354 } 355 356 SYSCTL_SETUP(sysctl_module_setup, "sysctl module setup") 357 { 358 const struct sysctlnode *node = NULL; 359 360 sysctl_createv(clog, 0, NULL, NULL, 361 CTLFLAG_PERMANENT, 362 CTLTYPE_NODE, "kern", NULL, 363 NULL, 0, NULL, 0, 364 CTL_KERN, CTL_EOL); 365 sysctl_createv(clog, 0, NULL, &node, 366 CTLFLAG_PERMANENT, 367 CTLTYPE_NODE, "module", 368 SYSCTL_DESCR("Module options"), 369 NULL, 0, NULL, 0, 370 CTL_KERN, CTL_CREATE, CTL_EOL); 371 372 if (node == NULL) 373 return; 374 375 sysctl_createv(clog, 0, &node, NULL, 376 CTLFLAG_PERMANENT | CTLFLAG_READWRITE, 377 CTLTYPE_BOOL, "autoload", 378 SYSCTL_DESCR("Enable automatic load of modules"), 379 NULL, 0, &module_autoload_on, 0, 380 CTL_CREATE, CTL_EOL); 381 sysctl_createv(clog, 0, &node, NULL, 382 CTLFLAG_PERMANENT | CTLFLAG_READWRITE, 383 CTLTYPE_BOOL, "verbose", 384 SYSCTL_DESCR("Enable verbose output"), 385 NULL, 0, &module_verbose_on, 0, 386 CTL_CREATE, CTL_EOL); 387 } 388 389 /* 390 * module_init_class: 391 * 392 * Initialize all built-in and pre-loaded modules of the 393 * specified class. 394 */ 395 void 396 module_init_class(modclass_t class) 397 { 398 TAILQ_HEAD(, module) bi_fail = TAILQ_HEAD_INITIALIZER(bi_fail); 399 module_t *mod; 400 modinfo_t *mi; 401 402 mutex_enter(&module_lock); 403 /* 404 * Builtins first. These will not depend on pre-loaded modules 405 * (because the kernel would not link). 406 */ 407 do { 408 TAILQ_FOREACH(mod, &module_builtins, mod_chain) { 409 mi = mod->mod_info; 410 if (class != MODULE_CLASS_ANY && class != mi->mi_class) 411 continue; 412 /* 413 * If initializing a builtin module fails, don't try 414 * to load it again. But keep it around and queue it 415 * on the disabled list after we're done with module 416 * init. 417 */ 418 if (module_do_builtin(mi->mi_name, NULL) != 0) { 419 TAILQ_REMOVE(&module_builtins, mod, mod_chain); 420 TAILQ_INSERT_TAIL(&bi_fail, mod, mod_chain); 421 } 422 break; 423 } 424 } while (mod != NULL); 425 426 /* 427 * Now preloaded modules. These will be pulled off the 428 * list as we call module_do_load(); 429 */ 430 do { 431 TAILQ_FOREACH(mod, &module_bootlist, mod_chain) { 432 mi = mod->mod_info; 433 if (class != MODULE_CLASS_ANY && class != mi->mi_class) 434 continue; 435 module_do_load(mi->mi_name, false, 0, NULL, NULL, 436 class, false); 437 break; 438 } 439 } while (mod != NULL); 440 441 /* failed builtin modules remain disabled */ 442 while ((mod = TAILQ_FIRST(&bi_fail)) != NULL) { 443 TAILQ_REMOVE(&bi_fail, mod, mod_chain); 444 TAILQ_INSERT_TAIL(&module_builtins, mod, mod_chain); 445 } 446 447 mutex_exit(&module_lock); 448 } 449 450 /* 451 * module_compatible: 452 * 453 * Return true if the two supplied kernel versions are said to 454 * have the same binary interface for kernel code. The entire 455 * version is signficant for the development tree (-current), 456 * major and minor versions are significant for official 457 * releases of the system. 458 */ 459 bool 460 module_compatible(int v1, int v2) 461 { 462 463 #if __NetBSD_Version__ / 1000000 % 100 == 99 /* -current */ 464 return v1 == v2; 465 #else /* release */ 466 return abs(v1 - v2) < 10000; 467 #endif 468 } 469 470 /* 471 * module_load: 472 * 473 * Load a single module from the file system. 474 */ 475 int 476 module_load(const char *filename, int flags, prop_dictionary_t props, 477 modclass_t class) 478 { 479 int error; 480 481 /* Authorize. */ 482 error = kauth_authorize_system(kauth_cred_get(), KAUTH_SYSTEM_MODULE, 483 0, (void *)(uintptr_t)MODCTL_LOAD, NULL, NULL); 484 if (error != 0) { 485 return error; 486 } 487 488 mutex_enter(&module_lock); 489 error = module_do_load(filename, false, flags, props, NULL, class, 490 false); 491 mutex_exit(&module_lock); 492 493 return error; 494 } 495 496 /* 497 * module_autoload: 498 * 499 * Load a single module from the file system, system initiated. 500 */ 501 int 502 module_autoload(const char *filename, modclass_t class) 503 { 504 int error; 505 506 KASSERT(mutex_owned(&module_lock)); 507 508 /* Nothing if the user has disabled it. */ 509 if (!module_autoload_on) { 510 return EPERM; 511 } 512 513 /* Disallow path separators and magic symlinks. */ 514 if (strchr(filename, '/') != NULL || strchr(filename, '@') != NULL || 515 strchr(filename, '.') != NULL) { 516 return EPERM; 517 } 518 519 /* Authorize. */ 520 error = kauth_authorize_system(kauth_cred_get(), KAUTH_SYSTEM_MODULE, 521 0, (void *)(uintptr_t)MODCTL_LOAD, (void *)(uintptr_t)1, NULL); 522 if (error != 0) { 523 return error; 524 } 525 526 return module_do_load(filename, false, 0, NULL, NULL, class, true); 527 } 528 529 /* 530 * module_unload: 531 * 532 * Find and unload a module by name. 533 */ 534 int 535 module_unload(const char *name) 536 { 537 int error; 538 539 /* Authorize. */ 540 error = kauth_authorize_system(kauth_cred_get(), KAUTH_SYSTEM_MODULE, 541 0, (void *)(uintptr_t)MODCTL_UNLOAD, NULL, NULL); 542 if (error != 0) { 543 return error; 544 } 545 546 mutex_enter(&module_lock); 547 error = module_do_unload(name); 548 mutex_exit(&module_lock); 549 550 return error; 551 } 552 553 /* 554 * module_lookup: 555 * 556 * Look up a module by name. 557 */ 558 module_t * 559 module_lookup(const char *name) 560 { 561 module_t *mod; 562 563 KASSERT(mutex_owned(&module_lock)); 564 565 TAILQ_FOREACH(mod, &module_list, mod_chain) { 566 if (strcmp(mod->mod_info->mi_name, name) == 0) { 567 break; 568 } 569 } 570 571 return mod; 572 } 573 574 /* 575 * module_hold: 576 * 577 * Add a single reference to a module. It's the caller's 578 * responsibility to ensure that the reference is dropped 579 * later. 580 */ 581 int 582 module_hold(const char *name) 583 { 584 module_t *mod; 585 586 mutex_enter(&module_lock); 587 mod = module_lookup(name); 588 if (mod == NULL) { 589 mutex_exit(&module_lock); 590 return ENOENT; 591 } 592 mod->mod_refcnt++; 593 mutex_exit(&module_lock); 594 595 return 0; 596 } 597 598 /* 599 * module_rele: 600 * 601 * Release a reference acquired with module_hold(). 602 */ 603 void 604 module_rele(const char *name) 605 { 606 module_t *mod; 607 608 mutex_enter(&module_lock); 609 mod = module_lookup(name); 610 if (mod == NULL) { 611 mutex_exit(&module_lock); 612 panic("module_rele: gone"); 613 } 614 mod->mod_refcnt--; 615 mutex_exit(&module_lock); 616 } 617 618 /* 619 * module_enqueue: 620 * 621 * Put a module onto the global list and update counters. 622 */ 623 void 624 module_enqueue(module_t *mod) 625 { 626 int i; 627 628 KASSERT(mutex_owned(&module_lock)); 629 630 /* 631 * If there are requisite modules, put at the head of the queue. 632 * This is so that autounload can unload requisite modules with 633 * only one pass through the queue. 634 */ 635 if (mod->mod_nrequired) { 636 TAILQ_INSERT_HEAD(&module_list, mod, mod_chain); 637 638 /* Add references to the requisite modules. */ 639 for (i = 0; i < mod->mod_nrequired; i++) { 640 KASSERT(mod->mod_required[i] != NULL); 641 mod->mod_required[i]->mod_refcnt++; 642 } 643 } else { 644 TAILQ_INSERT_TAIL(&module_list, mod, mod_chain); 645 } 646 module_count++; 647 module_gen++; 648 } 649 650 /* 651 * module_do_builtin: 652 * 653 * Initialize a module from the list of modules that are 654 * already linked into the kernel. 655 */ 656 static int 657 module_do_builtin(const char *name, module_t **modp) 658 { 659 const char *p, *s; 660 char buf[MAXMODNAME]; 661 modinfo_t *mi = NULL; 662 module_t *mod, *mod2, *mod_loaded; 663 size_t len; 664 int error; 665 666 KASSERT(mutex_owned(&module_lock)); 667 668 /* 669 * Search the list to see if we have a module by this name. 670 */ 671 TAILQ_FOREACH(mod, &module_builtins, mod_chain) { 672 if (strcmp(mod->mod_info->mi_name, name) == 0) { 673 mi = mod->mod_info; 674 break; 675 } 676 } 677 678 /* 679 * Check to see if already loaded. This might happen if we 680 * were already loaded as a dependency. 681 */ 682 if ((mod_loaded = module_lookup(name)) != NULL) { 683 KASSERT(mod == NULL); 684 if (modp) 685 *modp = mod_loaded; 686 return 0; 687 } 688 689 /* Note! This is from TAILQ, not immediate above */ 690 if (mi == NULL) { 691 /* 692 * XXX: We'd like to panic here, but currently in some 693 * cases (such as nfsserver + nfs), the dependee can be 694 * succesfully linked without the dependencies. 695 */ 696 module_error("can't find builtin dependency `%s'", name); 697 return ENOENT; 698 } 699 700 /* 701 * Initialize pre-requisites. 702 */ 703 if (mi->mi_required != NULL) { 704 for (s = mi->mi_required; *s != '\0'; s = p) { 705 if (*s == ',') 706 s++; 707 p = s; 708 while (*p != '\0' && *p != ',') 709 p++; 710 len = min(p - s + 1, sizeof(buf)); 711 strlcpy(buf, s, len); 712 if (buf[0] == '\0') 713 break; 714 if (mod->mod_nrequired == MAXMODDEPS - 1) { 715 module_error("too many required modules"); 716 return EINVAL; 717 } 718 error = module_do_builtin(buf, &mod2); 719 if (error != 0) { 720 return error; 721 } 722 mod->mod_required[mod->mod_nrequired++] = mod2; 723 } 724 } 725 726 /* 727 * Try to initialize the module. 728 */ 729 KASSERT(module_active == NULL); 730 module_active = mod; 731 error = (*mi->mi_modcmd)(MODULE_CMD_INIT, NULL); 732 module_active = NULL; 733 if (error != 0) { 734 module_error("builtin module `%s' " 735 "failed to init", mi->mi_name); 736 return error; 737 } 738 739 /* load always succeeds after this point */ 740 741 TAILQ_REMOVE(&module_builtins, mod, mod_chain); 742 module_builtinlist--; 743 if (modp != NULL) { 744 *modp = mod; 745 } 746 if (mi->mi_class == MODULE_CLASS_SECMODEL) 747 secmodel_register(); 748 module_enqueue(mod); 749 return 0; 750 } 751 752 /* 753 * module_do_load: 754 * 755 * Helper routine: load a module from the file system, or one 756 * pushed by the boot loader. 757 */ 758 static int 759 module_do_load(const char *name, bool isdep, int flags, 760 prop_dictionary_t props, module_t **modp, modclass_t class, 761 bool autoload) 762 { 763 static TAILQ_HEAD(,module) pending = TAILQ_HEAD_INITIALIZER(pending); 764 static int depth; 765 const int maxdepth = 6; 766 modinfo_t *mi; 767 module_t *mod, *mod2; 768 prop_dictionary_t filedict; 769 char buf[MAXMODNAME]; 770 const char *s, *p; 771 int error; 772 size_t len; 773 774 KASSERT(mutex_owned(&module_lock)); 775 776 filedict = NULL; 777 error = 0; 778 779 /* 780 * Avoid recursing too far. 781 */ 782 if (++depth > maxdepth) { 783 module_error("too many required modules"); 784 depth--; 785 return EMLINK; 786 } 787 788 /* 789 * Search the list of disabled builtins first. 790 */ 791 TAILQ_FOREACH(mod, &module_builtins, mod_chain) { 792 if (strcmp(mod->mod_info->mi_name, name) == 0) { 793 break; 794 } 795 } 796 if (mod) { 797 if ((flags & MODCTL_LOAD_FORCE) == 0) { 798 if (!autoload) { 799 module_error("use -f to reinstate " 800 "builtin module \"%s\"", name); 801 } 802 depth--; 803 return EPERM; 804 } else { 805 error = module_do_builtin(name, NULL); 806 depth--; 807 return error; 808 } 809 } 810 811 /* 812 * Load the module and link. Before going to the file system, 813 * scan the list of modules loaded by the boot loader. 814 */ 815 TAILQ_FOREACH(mod, &module_bootlist, mod_chain) { 816 if (strcmp(mod->mod_info->mi_name, name) == 0) { 817 TAILQ_REMOVE(&module_bootlist, mod, mod_chain); 818 break; 819 } 820 } 821 if (mod != NULL) { 822 TAILQ_INSERT_TAIL(&pending, mod, mod_chain); 823 } else { 824 /* 825 * If a requisite module, check to see if it is 826 * already present. 827 */ 828 if (isdep) { 829 TAILQ_FOREACH(mod, &module_list, mod_chain) { 830 if (strcmp(mod->mod_info->mi_name, name) == 0) { 831 break; 832 } 833 } 834 if (mod != NULL) { 835 if (modp != NULL) { 836 *modp = mod; 837 } 838 depth--; 839 return 0; 840 } 841 } 842 mod = kmem_zalloc(sizeof(*mod), KM_SLEEP); 843 if (mod == NULL) { 844 module_error("out of memory for `%s'", name); 845 depth--; 846 return ENOMEM; 847 } 848 849 error = module_load_vfs(name, flags, autoload, mod, &filedict); 850 if (error != 0) { 851 kmem_free(mod, sizeof(*mod)); 852 depth--; 853 return error; 854 } 855 mod->mod_source = MODULE_SOURCE_FILESYS; 856 TAILQ_INSERT_TAIL(&pending, mod, mod_chain); 857 858 error = module_fetch_info(mod); 859 if (error != 0) { 860 module_error("cannot fetch module info for `%s'", 861 name); 862 goto fail; 863 } 864 } 865 866 /* 867 * Check compatibility. 868 */ 869 mi = mod->mod_info; 870 if (strlen(mi->mi_name) >= MAXMODNAME) { 871 error = EINVAL; 872 module_error("module name `%s' too long", mi->mi_name); 873 goto fail; 874 } 875 if (!module_compatible(mi->mi_version, __NetBSD_Version__)) { 876 module_error("module built for `%d', system `%d'", 877 mi->mi_version, __NetBSD_Version__); 878 if ((flags & MODCTL_LOAD_FORCE) != 0) { 879 module_error("forced load, system may be unstable"); 880 } else { 881 error = EPROGMISMATCH; 882 goto fail; 883 } 884 } 885 886 /* 887 * If a specific kind of module was requested, ensure that we have 888 * a match. 889 */ 890 if (class != MODULE_CLASS_ANY && class != mi->mi_class) { 891 module_print("incompatible module class for `%s' (%d != %d)", 892 name, class, mi->mi_class); 893 error = ENOENT; 894 goto fail; 895 } 896 897 /* 898 * If loading a dependency, `name' is a plain module name. 899 * The name must match. 900 */ 901 if (isdep && strcmp(mi->mi_name, name) != 0) { 902 module_error("dependency name mismatch (`%s' != `%s')", 903 name, mi->mi_name); 904 error = ENOENT; 905 goto fail; 906 } 907 908 /* 909 * Check to see if the module is already loaded. If so, we may 910 * have been recursively called to handle a dependency, so be sure 911 * to set modp. 912 */ 913 if ((mod2 = module_lookup(mi->mi_name)) != NULL) { 914 if (modp != NULL) 915 *modp = mod2; 916 module_print("module `%s' already loaded", mi->mi_name); 917 error = EEXIST; 918 goto fail; 919 } 920 921 /* 922 * Block circular dependencies. 923 */ 924 TAILQ_FOREACH(mod2, &pending, mod_chain) { 925 if (mod == mod2) { 926 continue; 927 } 928 if (strcmp(mod2->mod_info->mi_name, mi->mi_name) == 0) { 929 error = EDEADLK; 930 module_error("circular dependency detected for `%s'", 931 mi->mi_name); 932 goto fail; 933 } 934 } 935 936 /* 937 * Now try to load any requisite modules. 938 */ 939 if (mi->mi_required != NULL) { 940 for (s = mi->mi_required; *s != '\0'; s = p) { 941 if (*s == ',') 942 s++; 943 p = s; 944 while (*p != '\0' && *p != ',') 945 p++; 946 len = p - s + 1; 947 if (len >= MAXMODNAME) { 948 error = EINVAL; 949 module_error("required module name `%s'" 950 " too long", mi->mi_required); 951 goto fail; 952 } 953 strlcpy(buf, s, len); 954 if (buf[0] == '\0') 955 break; 956 if (mod->mod_nrequired == MAXMODDEPS - 1) { 957 error = EINVAL; 958 module_error("too many required modules (%d)", 959 mod->mod_nrequired); 960 goto fail; 961 } 962 if (strcmp(buf, mi->mi_name) == 0) { 963 error = EDEADLK; 964 module_error("self-dependency detected for " 965 "`%s'", mi->mi_name); 966 goto fail; 967 } 968 error = module_do_load(buf, true, flags, NULL, 969 &mod->mod_required[mod->mod_nrequired++], 970 MODULE_CLASS_ANY, true); 971 if (error != 0) 972 goto fail; 973 } 974 } 975 976 /* 977 * We loaded all needed modules successfully: perform global 978 * relocations and initialize. 979 */ 980 error = kobj_affix(mod->mod_kobj, mi->mi_name); 981 if (error != 0) { 982 /* Cannot touch 'mi' as the module is now gone. */ 983 module_error("unable to affix module `%s'", name); 984 goto fail2; 985 } 986 987 if (filedict) { 988 if (!module_merge_dicts(filedict, props)) { 989 module_error("module properties failed"); 990 error = EINVAL; 991 goto fail; 992 } 993 } 994 KASSERT(module_active == NULL); 995 module_active = mod; 996 error = (*mi->mi_modcmd)(MODULE_CMD_INIT, filedict ? filedict : props); 997 module_active = NULL; 998 if (filedict) { 999 prop_object_release(filedict); 1000 filedict = NULL; 1001 } 1002 if (error != 0) { 1003 module_error("modcmd function returned error %d for `%s'", 1004 error, mi->mi_name); 1005 goto fail; 1006 } 1007 1008 if (mi->mi_class == MODULE_CLASS_SECMODEL) 1009 secmodel_register(); 1010 1011 /* 1012 * Good, the module loaded successfully. Put it onto the 1013 * list and add references to its requisite modules. 1014 */ 1015 TAILQ_REMOVE(&pending, mod, mod_chain); 1016 module_enqueue(mod); 1017 if (modp != NULL) { 1018 *modp = mod; 1019 } 1020 if (autoload) { 1021 /* 1022 * Arrange to try unloading the module after 1023 * a short delay. 1024 */ 1025 mod->mod_autotime = time_second + module_autotime; 1026 module_thread_kick(); 1027 } 1028 depth--; 1029 return 0; 1030 1031 fail: 1032 kobj_unload(mod->mod_kobj); 1033 fail2: 1034 if (filedict != NULL) { 1035 prop_object_release(filedict); 1036 filedict = NULL; 1037 } 1038 TAILQ_REMOVE(&pending, mod, mod_chain); 1039 kmem_free(mod, sizeof(*mod)); 1040 depth--; 1041 return error; 1042 } 1043 1044 /* 1045 * module_do_unload: 1046 * 1047 * Helper routine: do the dirty work of unloading a module. 1048 */ 1049 static int 1050 module_do_unload(const char *name) 1051 { 1052 module_t *mod; 1053 int error; 1054 u_int i; 1055 1056 KASSERT(mutex_owned(&module_lock)); 1057 1058 mod = module_lookup(name); 1059 if (mod == NULL) { 1060 module_error("module `%s' not found", name); 1061 return ENOENT; 1062 } 1063 if (mod->mod_refcnt != 0) { 1064 module_print("module `%s' busy", name); 1065 return EBUSY; 1066 } 1067 KASSERT(module_active == NULL); 1068 module_active = mod; 1069 error = (*mod->mod_info->mi_modcmd)(MODULE_CMD_FINI, NULL); 1070 module_active = NULL; 1071 if (error != 0) { 1072 module_print("cannot unload module `%s' error=%d", name, 1073 error); 1074 return error; 1075 } 1076 if (mod->mod_info->mi_class == MODULE_CLASS_SECMODEL) 1077 secmodel_deregister(); 1078 module_count--; 1079 TAILQ_REMOVE(&module_list, mod, mod_chain); 1080 for (i = 0; i < mod->mod_nrequired; i++) { 1081 mod->mod_required[i]->mod_refcnt--; 1082 } 1083 if (mod->mod_kobj != NULL) { 1084 kobj_unload(mod->mod_kobj); 1085 } 1086 if (mod->mod_source == MODULE_SOURCE_KERNEL) { 1087 mod->mod_nrequired = 0; /* will be re-parsed */ 1088 TAILQ_INSERT_TAIL(&module_builtins, mod, mod_chain); 1089 module_builtinlist++; 1090 } else { 1091 kmem_free(mod, sizeof(*mod)); 1092 } 1093 module_gen++; 1094 1095 return 0; 1096 } 1097 1098 /* 1099 * module_prime: 1100 * 1101 * Push a module loaded by the bootloader onto our internal 1102 * list. 1103 */ 1104 int 1105 module_prime(void *base, size_t size) 1106 { 1107 module_t *mod; 1108 int error; 1109 1110 mod = kmem_zalloc(sizeof(*mod), KM_SLEEP); 1111 if (mod == NULL) { 1112 return ENOMEM; 1113 } 1114 mod->mod_source = MODULE_SOURCE_BOOT; 1115 1116 error = kobj_load_mem(&mod->mod_kobj, base, size); 1117 if (error != 0) { 1118 kmem_free(mod, sizeof(*mod)); 1119 module_error("unable to load object pushed by boot loader"); 1120 return error; 1121 } 1122 error = module_fetch_info(mod); 1123 if (error != 0) { 1124 kobj_unload(mod->mod_kobj); 1125 kmem_free(mod, sizeof(*mod)); 1126 module_error("unable to load object pushed by boot loader"); 1127 return error; 1128 } 1129 1130 TAILQ_INSERT_TAIL(&module_bootlist, mod, mod_chain); 1131 1132 return 0; 1133 } 1134 1135 /* 1136 * module_fetch_into: 1137 * 1138 * Fetch modinfo record from a loaded module. 1139 */ 1140 static int 1141 module_fetch_info(module_t *mod) 1142 { 1143 int error; 1144 void *addr; 1145 size_t size; 1146 1147 /* 1148 * Find module info record and check compatibility. 1149 */ 1150 error = kobj_find_section(mod->mod_kobj, "link_set_modules", 1151 &addr, &size); 1152 if (error != 0) { 1153 module_error("`link_set_modules' section not present"); 1154 return error; 1155 } 1156 if (size != sizeof(modinfo_t **)) { 1157 module_error("`link_set_modules' section wrong size"); 1158 return error; 1159 } 1160 mod->mod_info = *(modinfo_t **)addr; 1161 1162 return 0; 1163 } 1164 1165 /* 1166 * module_find_section: 1167 * 1168 * Allows a module that is being initialized to look up a section 1169 * within its ELF object. 1170 */ 1171 int 1172 module_find_section(const char *name, void **addr, size_t *size) 1173 { 1174 1175 KASSERT(mutex_owned(&module_lock)); 1176 KASSERT(module_active != NULL); 1177 1178 return kobj_find_section(module_active->mod_kobj, name, addr, size); 1179 } 1180 1181 /* 1182 * module_thread: 1183 * 1184 * Automatically unload modules. We try once to unload autoloaded 1185 * modules after module_autotime seconds. If the system is under 1186 * severe memory pressure, we'll try unloading all modules. 1187 */ 1188 static void 1189 module_thread(void *cookie) 1190 { 1191 module_t *mod, *next; 1192 modinfo_t *mi; 1193 int error; 1194 1195 for (;;) { 1196 mutex_enter(&module_lock); 1197 for (mod = TAILQ_FIRST(&module_list); mod != NULL; mod = next) { 1198 next = TAILQ_NEXT(mod, mod_chain); 1199 if (mod->mod_source == MODULE_SOURCE_KERNEL) 1200 continue; 1201 if (uvmexp.free < uvmexp.freemin) { 1202 module_thread_ticks = hz; 1203 } else if (mod->mod_autotime == 0) { 1204 continue; 1205 } else if (time_second < mod->mod_autotime) { 1206 module_thread_ticks = hz; 1207 continue; 1208 } else { 1209 mod->mod_autotime = 0; 1210 } 1211 /* 1212 * If this module wants to avoid autounload then 1213 * skip it. Some modules can ping-pong in and out 1214 * because their use is transient but often. 1215 * Example: exec_script. 1216 */ 1217 mi = mod->mod_info; 1218 error = (*mi->mi_modcmd)(MODULE_CMD_AUTOUNLOAD, NULL); 1219 if (error == 0 || error == ENOTTY) { 1220 (void)module_do_unload(mi->mi_name); 1221 } 1222 } 1223 mutex_exit(&module_lock); 1224 1225 mutex_enter(&module_thread_lock); 1226 (void)cv_timedwait(&module_thread_cv, &module_thread_lock, 1227 module_thread_ticks); 1228 module_thread_ticks = 0; 1229 mutex_exit(&module_thread_lock); 1230 } 1231 } 1232 1233 /* 1234 * module_thread: 1235 * 1236 * Kick the module thread into action, perhaps because the 1237 * system is low on memory. 1238 */ 1239 void 1240 module_thread_kick(void) 1241 { 1242 1243 mutex_enter(&module_thread_lock); 1244 module_thread_ticks = hz; 1245 cv_broadcast(&module_thread_cv); 1246 mutex_exit(&module_thread_lock); 1247 } 1248 1249 #ifdef DDB 1250 /* 1251 * module_whatis: 1252 * 1253 * Helper routine for DDB. 1254 */ 1255 void 1256 module_whatis(uintptr_t addr, void (*pr)(const char *, ...)) 1257 { 1258 module_t *mod; 1259 size_t msize; 1260 vaddr_t maddr; 1261 1262 TAILQ_FOREACH(mod, &module_list, mod_chain) { 1263 if (mod->mod_kobj == NULL) { 1264 continue; 1265 } 1266 if (kobj_stat(mod->mod_kobj, &maddr, &msize) != 0) 1267 continue; 1268 if (addr < maddr || addr >= maddr + msize) { 1269 continue; 1270 } 1271 (*pr)("%p is %p+%zu, in kernel module `%s'\n", 1272 (void *)addr, (void *)maddr, 1273 (size_t)(addr - maddr), mod->mod_info->mi_name); 1274 } 1275 } 1276 1277 /* 1278 * module_print_list: 1279 * 1280 * Helper routine for DDB. 1281 */ 1282 void 1283 module_print_list(void (*pr)(const char *, ...)) 1284 { 1285 const char *src; 1286 module_t *mod; 1287 size_t msize; 1288 vaddr_t maddr; 1289 1290 (*pr)("%16s %16s %8s %8s\n", "NAME", "TEXT/DATA", "SIZE", "SOURCE"); 1291 1292 TAILQ_FOREACH(mod, &module_list, mod_chain) { 1293 switch (mod->mod_source) { 1294 case MODULE_SOURCE_KERNEL: 1295 src = "builtin"; 1296 break; 1297 case MODULE_SOURCE_FILESYS: 1298 src = "filesys"; 1299 break; 1300 case MODULE_SOURCE_BOOT: 1301 src = "boot"; 1302 break; 1303 default: 1304 src = "unknown"; 1305 break; 1306 } 1307 if (mod->mod_kobj == NULL) { 1308 maddr = 0; 1309 msize = 0; 1310 } else if (kobj_stat(mod->mod_kobj, &maddr, &msize) != 0) 1311 continue; 1312 (*pr)("%16s %16lx %8ld %8s\n", mod->mod_info->mi_name, 1313 (long)maddr, (long)msize, src); 1314 } 1315 } 1316 #endif /* DDB */ 1317 1318 static bool 1319 module_merge_dicts(prop_dictionary_t existing_dict, 1320 const prop_dictionary_t new_dict) 1321 { 1322 prop_dictionary_keysym_t props_keysym; 1323 prop_object_iterator_t props_iter; 1324 prop_object_t props_obj; 1325 const char *props_key; 1326 bool error; 1327 1328 if (new_dict == NULL) { /* nothing to merge */ 1329 return true; 1330 } 1331 1332 error = false; 1333 props_iter = prop_dictionary_iterator(new_dict); 1334 if (props_iter == NULL) { 1335 return false; 1336 } 1337 1338 while ((props_obj = prop_object_iterator_next(props_iter)) != NULL) { 1339 props_keysym = (prop_dictionary_keysym_t)props_obj; 1340 props_key = prop_dictionary_keysym_cstring_nocopy(props_keysym); 1341 props_obj = prop_dictionary_get_keysym(new_dict, props_keysym); 1342 if ((props_obj == NULL) || !prop_dictionary_set(existing_dict, 1343 props_key, props_obj)) { 1344 error = true; 1345 goto out; 1346 } 1347 } 1348 error = false; 1349 1350 out: 1351 prop_object_iterator_release(props_iter); 1352 1353 return !error; 1354 } 1355