1 /* $NetBSD: kern_module.c,v 1.69 2010/05/26 23:53:21 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 1.69 2010/05/26 23:53:21 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 int (*module_load_vfs_vec)(const char *, int, bool, module_t *, 82 prop_dictionary_t *) = (void *)eopnotsupp; 83 84 static kauth_listener_t module_listener; 85 86 /* Ensure that the kernel's link set isn't empty. */ 87 static modinfo_t module_dummy; 88 __link_set_add_rodata(modules, module_dummy); 89 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 *); 93 static int module_do_builtin(const char *, module_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 * Add modules to the builtin list. This can done at boottime or 159 * at runtime if the module is linked into the kernel with an 160 * external linker. All or none of the input will be handled. 161 * Optionally, the modules can be initialized. If they are not 162 * initialized, module_init_class() or module_load() can be used 163 * later, but these are not guaranteed to give atomic results. 164 */ 165 int 166 module_builtin_add(modinfo_t *const *mip, size_t nmodinfo, bool init) 167 { 168 struct module **modp = NULL, *mod_iter; 169 int rv = 0, i, mipskip; 170 171 if (init) { 172 rv = kauth_authorize_system(kauth_cred_get(), 173 KAUTH_SYSTEM_MODULE, 0, (void *)(uintptr_t)MODCTL_LOAD, 174 (void *)(uintptr_t)1, NULL); 175 if (rv) { 176 return rv; 177 } 178 } 179 180 for (i = 0, mipskip = 0; i < nmodinfo; i++) { 181 if (mip[i] == &module_dummy) { 182 KASSERT(nmodinfo > 0); 183 nmodinfo--; 184 } 185 } 186 if (nmodinfo == 0) 187 return 0; 188 189 modp = kmem_zalloc(sizeof(*modp) * nmodinfo, KM_SLEEP); 190 for (i = 0, mipskip = 0; i < nmodinfo; i++) { 191 if (mip[i+mipskip] == &module_dummy) { 192 mipskip++; 193 continue; 194 } 195 modp[i] = kmem_zalloc(sizeof(*modp[i]), KM_SLEEP); 196 modp[i]->mod_info = mip[i+mipskip]; 197 modp[i]->mod_source = MODULE_SOURCE_KERNEL; 198 } 199 mutex_enter(&module_lock); 200 201 /* do this in three stages for error recovery and atomicity */ 202 203 /* first check for presence */ 204 for (i = 0; i < nmodinfo; i++) { 205 TAILQ_FOREACH(mod_iter, &module_builtins, mod_chain) { 206 if (strcmp(mod_iter->mod_info->mi_name, 207 modp[i]->mod_info->mi_name) == 0) 208 break; 209 } 210 if (mod_iter) { 211 rv = EEXIST; 212 goto out; 213 } 214 215 if (module_lookup(modp[i]->mod_info->mi_name) != NULL) { 216 rv = EEXIST; 217 goto out; 218 } 219 } 220 221 /* then add to list */ 222 for (i = 0; i < nmodinfo; i++) { 223 TAILQ_INSERT_TAIL(&module_builtins, modp[i], mod_chain); 224 module_builtinlist++; 225 } 226 227 /* finally, init (if required) */ 228 if (init) { 229 for (i = 0; i < nmodinfo; i++) { 230 rv = module_do_builtin(modp[i]->mod_info->mi_name,NULL); 231 /* throw in the towel, recovery hard & not worth it */ 232 if (rv) 233 panic("builtin module \"%s\" init failed: %d", 234 modp[i]->mod_info->mi_name, rv); 235 } 236 } 237 238 out: 239 mutex_exit(&module_lock); 240 if (rv != 0) { 241 for (i = 0; i < nmodinfo; i++) { 242 if (modp[i]) 243 kmem_free(modp[i], sizeof(*modp[i])); 244 } 245 } 246 kmem_free(modp, sizeof(*modp) * nmodinfo); 247 return rv; 248 } 249 250 /* 251 * Optionally fini and remove builtin module from the kernel. 252 * Note: the module will now be unreachable except via mi && builtin_add. 253 */ 254 int 255 module_builtin_remove(modinfo_t *mi, bool fini) 256 { 257 struct module *mod; 258 int rv = 0; 259 260 if (fini) { 261 rv = kauth_authorize_system(kauth_cred_get(), 262 KAUTH_SYSTEM_MODULE, 0, (void *)(uintptr_t)MODCTL_UNLOAD, 263 NULL, NULL); 264 if (rv) 265 return rv; 266 267 mutex_enter(&module_lock); 268 rv = module_do_unload(mi->mi_name); 269 if (rv) { 270 goto out; 271 } 272 } else { 273 mutex_enter(&module_lock); 274 } 275 TAILQ_FOREACH(mod, &module_builtins, mod_chain) { 276 if (strcmp(mod->mod_info->mi_name, mi->mi_name) == 0) 277 break; 278 } 279 if (mod) { 280 TAILQ_REMOVE(&module_builtins, mod, mod_chain); 281 module_builtinlist--; 282 } else { 283 KASSERT(fini == false); 284 rv = ENOENT; 285 } 286 287 out: 288 mutex_exit(&module_lock); 289 return rv; 290 } 291 292 /* 293 * module_init: 294 * 295 * Initialize the module subsystem. 296 */ 297 void 298 module_init(void) 299 { 300 __link_set_decl(modules, modinfo_t); 301 extern struct vm_map *module_map; 302 modinfo_t *const *mip; 303 int rv; 304 305 if (module_map == NULL) { 306 module_map = kernel_map; 307 } 308 mutex_init(&module_lock, MUTEX_DEFAULT, IPL_NONE); 309 cv_init(&module_thread_cv, "modunload"); 310 mutex_init(&module_thread_lock, MUTEX_DEFAULT, IPL_NONE); 311 312 #ifdef MODULAR /* XXX */ 313 module_init_md(); 314 #endif 315 316 #if __NetBSD_Version__ / 1000000 % 100 == 99 /* -current */ 317 snprintf(module_base, sizeof(module_base), "/stand/%s/%s/modules", 318 machine, osrelease); 319 #else /* release */ 320 snprintf(module_base, sizeof(module_base), "/stand/%s/%d.%d/modules", 321 machine, __NetBSD_Version__ / 100000000, 322 __NetBSD_Version__ / 1000000 % 100); 323 #endif 324 325 module_listener = kauth_listen_scope(KAUTH_SCOPE_SYSTEM, 326 module_listener_cb, NULL); 327 328 __link_set_foreach(mip, modules) { 329 if ((rv = module_builtin_add(mip, 1, false) != 0)) 330 module_error("builtin %s failed: %d\n", 331 (*mip)->mi_name, rv); 332 } 333 334 sysctl_module_setup(); 335 } 336 337 /* 338 * module_init2: 339 * 340 * Start the auto unload kthread. 341 */ 342 void 343 module_init2(void) 344 { 345 int error; 346 347 error = kthread_create(PRI_VM, KTHREAD_MPSAFE, NULL, module_thread, 348 NULL, NULL, "modunload"); 349 if (error != 0) 350 panic("module_init: %d", error); 351 } 352 353 static struct sysctllog *module_sysctllog; 354 355 static void 356 sysctl_module_setup(void) 357 { 358 const struct sysctlnode *node = NULL; 359 360 sysctl_createv(&module_sysctllog, 0, NULL, NULL, 361 CTLFLAG_PERMANENT, 362 CTLTYPE_NODE, "kern", NULL, 363 NULL, 0, NULL, 0, 364 CTL_KERN, CTL_EOL); 365 sysctl_createv(&module_sysctllog, 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(&module_sysctllog, 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(&module_sysctllog, 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_vec(name, flags, autoload, mod, 850 &filedict); 851 if (error != 0) { 852 kmem_free(mod, sizeof(*mod)); 853 depth--; 854 return error; 855 } 856 mod->mod_source = MODULE_SOURCE_FILESYS; 857 TAILQ_INSERT_TAIL(&pending, mod, mod_chain); 858 859 error = module_fetch_info(mod); 860 if (error != 0) { 861 module_error("cannot fetch module info for `%s'", 862 name); 863 goto fail; 864 } 865 } 866 867 /* 868 * Check compatibility. 869 */ 870 mi = mod->mod_info; 871 if (strlen(mi->mi_name) >= MAXMODNAME) { 872 error = EINVAL; 873 module_error("module name `%s' too long", mi->mi_name); 874 goto fail; 875 } 876 if (!module_compatible(mi->mi_version, __NetBSD_Version__)) { 877 module_error("module built for `%d', system `%d'", 878 mi->mi_version, __NetBSD_Version__); 879 if ((flags & MODCTL_LOAD_FORCE) != 0) { 880 module_error("forced load, system may be unstable"); 881 } else { 882 error = EPROGMISMATCH; 883 goto fail; 884 } 885 } 886 887 /* 888 * If a specific kind of module was requested, ensure that we have 889 * a match. 890 */ 891 if (class != MODULE_CLASS_ANY && class != mi->mi_class) { 892 module_print("incompatible module class for `%s' (%d != %d)", 893 name, class, mi->mi_class); 894 error = ENOENT; 895 goto fail; 896 } 897 898 /* 899 * If loading a dependency, `name' is a plain module name. 900 * The name must match. 901 */ 902 if (isdep && strcmp(mi->mi_name, name) != 0) { 903 module_error("dependency name mismatch (`%s' != `%s')", 904 name, mi->mi_name); 905 error = ENOENT; 906 goto fail; 907 } 908 909 /* 910 * Check to see if the module is already loaded. If so, we may 911 * have been recursively called to handle a dependency, so be sure 912 * to set modp. 913 */ 914 if ((mod2 = module_lookup(mi->mi_name)) != NULL) { 915 if (modp != NULL) 916 *modp = mod2; 917 module_print("module `%s' already loaded", mi->mi_name); 918 error = EEXIST; 919 goto fail; 920 } 921 922 /* 923 * Block circular dependencies. 924 */ 925 TAILQ_FOREACH(mod2, &pending, mod_chain) { 926 if (mod == mod2) { 927 continue; 928 } 929 if (strcmp(mod2->mod_info->mi_name, mi->mi_name) == 0) { 930 error = EDEADLK; 931 module_error("circular dependency detected for `%s'", 932 mi->mi_name); 933 goto fail; 934 } 935 } 936 937 /* 938 * Now try to load any requisite modules. 939 */ 940 if (mi->mi_required != NULL) { 941 for (s = mi->mi_required; *s != '\0'; s = p) { 942 if (*s == ',') 943 s++; 944 p = s; 945 while (*p != '\0' && *p != ',') 946 p++; 947 len = p - s + 1; 948 if (len >= MAXMODNAME) { 949 error = EINVAL; 950 module_error("required module name `%s'" 951 " too long", mi->mi_required); 952 goto fail; 953 } 954 strlcpy(buf, s, len); 955 if (buf[0] == '\0') 956 break; 957 if (mod->mod_nrequired == MAXMODDEPS - 1) { 958 error = EINVAL; 959 module_error("too many required modules (%d)", 960 mod->mod_nrequired); 961 goto fail; 962 } 963 if (strcmp(buf, mi->mi_name) == 0) { 964 error = EDEADLK; 965 module_error("self-dependency detected for " 966 "`%s'", mi->mi_name); 967 goto fail; 968 } 969 error = module_do_load(buf, true, flags, NULL, 970 &mod->mod_required[mod->mod_nrequired++], 971 MODULE_CLASS_ANY, true); 972 if (error != 0) 973 goto fail; 974 } 975 } 976 977 /* 978 * We loaded all needed modules successfully: perform global 979 * relocations and initialize. 980 */ 981 error = kobj_affix(mod->mod_kobj, mi->mi_name); 982 if (error != 0) { 983 /* Cannot touch 'mi' as the module is now gone. */ 984 module_error("unable to affix module `%s'", name); 985 goto fail2; 986 } 987 988 if (filedict) { 989 if (!module_merge_dicts(filedict, props)) { 990 module_error("module properties failed"); 991 error = EINVAL; 992 goto fail; 993 } 994 } 995 KASSERT(module_active == NULL); 996 module_active = mod; 997 error = (*mi->mi_modcmd)(MODULE_CMD_INIT, filedict ? filedict : props); 998 module_active = NULL; 999 if (filedict) { 1000 prop_object_release(filedict); 1001 filedict = NULL; 1002 } 1003 if (error != 0) { 1004 module_error("modcmd function returned error %d for `%s'", 1005 error, mi->mi_name); 1006 goto fail; 1007 } 1008 1009 if (mi->mi_class == MODULE_CLASS_SECMODEL) 1010 secmodel_register(); 1011 1012 /* 1013 * Good, the module loaded successfully. Put it onto the 1014 * list and add references to its requisite modules. 1015 */ 1016 TAILQ_REMOVE(&pending, mod, mod_chain); 1017 module_enqueue(mod); 1018 if (modp != NULL) { 1019 *modp = mod; 1020 } 1021 if (autoload) { 1022 /* 1023 * Arrange to try unloading the module after 1024 * a short delay. 1025 */ 1026 mod->mod_autotime = time_second + module_autotime; 1027 module_thread_kick(); 1028 } 1029 depth--; 1030 return 0; 1031 1032 fail: 1033 kobj_unload(mod->mod_kobj); 1034 fail2: 1035 if (filedict != NULL) { 1036 prop_object_release(filedict); 1037 filedict = NULL; 1038 } 1039 TAILQ_REMOVE(&pending, mod, mod_chain); 1040 kmem_free(mod, sizeof(*mod)); 1041 depth--; 1042 return error; 1043 } 1044 1045 /* 1046 * module_do_unload: 1047 * 1048 * Helper routine: do the dirty work of unloading a module. 1049 */ 1050 static int 1051 module_do_unload(const char *name) 1052 { 1053 module_t *mod; 1054 int error; 1055 u_int i; 1056 1057 KASSERT(mutex_owned(&module_lock)); 1058 1059 mod = module_lookup(name); 1060 if (mod == NULL) { 1061 module_error("module `%s' not found", name); 1062 return ENOENT; 1063 } 1064 if (mod->mod_refcnt != 0) { 1065 module_print("module `%s' busy", name); 1066 return EBUSY; 1067 } 1068 KASSERT(module_active == NULL); 1069 module_active = mod; 1070 error = (*mod->mod_info->mi_modcmd)(MODULE_CMD_FINI, NULL); 1071 module_active = NULL; 1072 if (error != 0) { 1073 module_print("cannot unload module `%s' error=%d", name, 1074 error); 1075 return error; 1076 } 1077 if (mod->mod_info->mi_class == MODULE_CLASS_SECMODEL) 1078 secmodel_deregister(); 1079 module_count--; 1080 TAILQ_REMOVE(&module_list, mod, mod_chain); 1081 for (i = 0; i < mod->mod_nrequired; i++) { 1082 mod->mod_required[i]->mod_refcnt--; 1083 } 1084 if (mod->mod_kobj != NULL) { 1085 kobj_unload(mod->mod_kobj); 1086 } 1087 if (mod->mod_source == MODULE_SOURCE_KERNEL) { 1088 mod->mod_nrequired = 0; /* will be re-parsed */ 1089 TAILQ_INSERT_TAIL(&module_builtins, mod, mod_chain); 1090 module_builtinlist++; 1091 } else { 1092 kmem_free(mod, sizeof(*mod)); 1093 } 1094 module_gen++; 1095 1096 return 0; 1097 } 1098 1099 /* 1100 * module_prime: 1101 * 1102 * Push a module loaded by the bootloader onto our internal 1103 * list. 1104 */ 1105 int 1106 module_prime(void *base, size_t size) 1107 { 1108 module_t *mod; 1109 int error; 1110 1111 mod = kmem_zalloc(sizeof(*mod), KM_SLEEP); 1112 if (mod == NULL) { 1113 return ENOMEM; 1114 } 1115 mod->mod_source = MODULE_SOURCE_BOOT; 1116 1117 error = kobj_load_mem(&mod->mod_kobj, base, size); 1118 if (error != 0) { 1119 kmem_free(mod, sizeof(*mod)); 1120 module_error("unable to load object pushed by boot loader"); 1121 return error; 1122 } 1123 error = module_fetch_info(mod); 1124 if (error != 0) { 1125 kobj_unload(mod->mod_kobj); 1126 kmem_free(mod, sizeof(*mod)); 1127 module_error("unable to load object pushed by boot loader"); 1128 return error; 1129 } 1130 1131 TAILQ_INSERT_TAIL(&module_bootlist, mod, mod_chain); 1132 1133 return 0; 1134 } 1135 1136 /* 1137 * module_fetch_into: 1138 * 1139 * Fetch modinfo record from a loaded module. 1140 */ 1141 static int 1142 module_fetch_info(module_t *mod) 1143 { 1144 int error; 1145 void *addr; 1146 size_t size; 1147 1148 /* 1149 * Find module info record and check compatibility. 1150 */ 1151 error = kobj_find_section(mod->mod_kobj, "link_set_modules", 1152 &addr, &size); 1153 if (error != 0) { 1154 module_error("`link_set_modules' section not present"); 1155 return error; 1156 } 1157 if (size != sizeof(modinfo_t **)) { 1158 module_error("`link_set_modules' section wrong size"); 1159 return error; 1160 } 1161 mod->mod_info = *(modinfo_t **)addr; 1162 1163 return 0; 1164 } 1165 1166 /* 1167 * module_find_section: 1168 * 1169 * Allows a module that is being initialized to look up a section 1170 * within its ELF object. 1171 */ 1172 int 1173 module_find_section(const char *name, void **addr, size_t *size) 1174 { 1175 1176 KASSERT(mutex_owned(&module_lock)); 1177 KASSERT(module_active != NULL); 1178 1179 return kobj_find_section(module_active->mod_kobj, name, addr, size); 1180 } 1181 1182 /* 1183 * module_thread: 1184 * 1185 * Automatically unload modules. We try once to unload autoloaded 1186 * modules after module_autotime seconds. If the system is under 1187 * severe memory pressure, we'll try unloading all modules. 1188 */ 1189 static void 1190 module_thread(void *cookie) 1191 { 1192 module_t *mod, *next; 1193 modinfo_t *mi; 1194 int error; 1195 1196 for (;;) { 1197 mutex_enter(&module_lock); 1198 for (mod = TAILQ_FIRST(&module_list); mod != NULL; mod = next) { 1199 next = TAILQ_NEXT(mod, mod_chain); 1200 if (mod->mod_source == MODULE_SOURCE_KERNEL) 1201 continue; 1202 if (uvmexp.free < uvmexp.freemin) { 1203 module_thread_ticks = hz; 1204 } else if (mod->mod_autotime == 0) { 1205 continue; 1206 } else if (time_second < mod->mod_autotime) { 1207 module_thread_ticks = hz; 1208 continue; 1209 } else { 1210 mod->mod_autotime = 0; 1211 } 1212 /* 1213 * If this module wants to avoid autounload then 1214 * skip it. Some modules can ping-pong in and out 1215 * because their use is transient but often. 1216 * Example: exec_script. 1217 */ 1218 mi = mod->mod_info; 1219 error = (*mi->mi_modcmd)(MODULE_CMD_AUTOUNLOAD, NULL); 1220 if (error == 0 || error == ENOTTY) { 1221 (void)module_do_unload(mi->mi_name); 1222 } 1223 } 1224 mutex_exit(&module_lock); 1225 1226 mutex_enter(&module_thread_lock); 1227 (void)cv_timedwait(&module_thread_cv, &module_thread_lock, 1228 module_thread_ticks); 1229 module_thread_ticks = 0; 1230 mutex_exit(&module_thread_lock); 1231 } 1232 } 1233 1234 /* 1235 * module_thread: 1236 * 1237 * Kick the module thread into action, perhaps because the 1238 * system is low on memory. 1239 */ 1240 void 1241 module_thread_kick(void) 1242 { 1243 1244 mutex_enter(&module_thread_lock); 1245 module_thread_ticks = hz; 1246 cv_broadcast(&module_thread_cv); 1247 mutex_exit(&module_thread_lock); 1248 } 1249 1250 #ifdef DDB 1251 /* 1252 * module_whatis: 1253 * 1254 * Helper routine for DDB. 1255 */ 1256 void 1257 module_whatis(uintptr_t addr, void (*pr)(const char *, ...)) 1258 { 1259 module_t *mod; 1260 size_t msize; 1261 vaddr_t maddr; 1262 1263 TAILQ_FOREACH(mod, &module_list, mod_chain) { 1264 if (mod->mod_kobj == NULL) { 1265 continue; 1266 } 1267 if (kobj_stat(mod->mod_kobj, &maddr, &msize) != 0) 1268 continue; 1269 if (addr < maddr || addr >= maddr + msize) { 1270 continue; 1271 } 1272 (*pr)("%p is %p+%zu, in kernel module `%s'\n", 1273 (void *)addr, (void *)maddr, 1274 (size_t)(addr - maddr), mod->mod_info->mi_name); 1275 } 1276 } 1277 1278 /* 1279 * module_print_list: 1280 * 1281 * Helper routine for DDB. 1282 */ 1283 void 1284 module_print_list(void (*pr)(const char *, ...)) 1285 { 1286 const char *src; 1287 module_t *mod; 1288 size_t msize; 1289 vaddr_t maddr; 1290 1291 (*pr)("%16s %16s %8s %8s\n", "NAME", "TEXT/DATA", "SIZE", "SOURCE"); 1292 1293 TAILQ_FOREACH(mod, &module_list, mod_chain) { 1294 switch (mod->mod_source) { 1295 case MODULE_SOURCE_KERNEL: 1296 src = "builtin"; 1297 break; 1298 case MODULE_SOURCE_FILESYS: 1299 src = "filesys"; 1300 break; 1301 case MODULE_SOURCE_BOOT: 1302 src = "boot"; 1303 break; 1304 default: 1305 src = "unknown"; 1306 break; 1307 } 1308 if (mod->mod_kobj == NULL) { 1309 maddr = 0; 1310 msize = 0; 1311 } else if (kobj_stat(mod->mod_kobj, &maddr, &msize) != 0) 1312 continue; 1313 (*pr)("%16s %16lx %8ld %8s\n", mod->mod_info->mi_name, 1314 (long)maddr, (long)msize, src); 1315 } 1316 } 1317 #endif /* DDB */ 1318 1319 static bool 1320 module_merge_dicts(prop_dictionary_t existing_dict, 1321 const prop_dictionary_t new_dict) 1322 { 1323 prop_dictionary_keysym_t props_keysym; 1324 prop_object_iterator_t props_iter; 1325 prop_object_t props_obj; 1326 const char *props_key; 1327 bool error; 1328 1329 if (new_dict == NULL) { /* nothing to merge */ 1330 return true; 1331 } 1332 1333 error = false; 1334 props_iter = prop_dictionary_iterator(new_dict); 1335 if (props_iter == NULL) { 1336 return false; 1337 } 1338 1339 while ((props_obj = prop_object_iterator_next(props_iter)) != NULL) { 1340 props_keysym = (prop_dictionary_keysym_t)props_obj; 1341 props_key = prop_dictionary_keysym_cstring_nocopy(props_keysym); 1342 props_obj = prop_dictionary_get_keysym(new_dict, props_keysym); 1343 if ((props_obj == NULL) || !prop_dictionary_set(existing_dict, 1344 props_key, props_obj)) { 1345 error = true; 1346 goto out; 1347 } 1348 } 1349 error = false; 1350 1351 out: 1352 prop_object_iterator_release(props_iter); 1353 1354 return !error; 1355 } 1356