1 /* $NetBSD: kern_module.c,v 1.70 2010/06/26 07:23:57 pgoyette 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 1.70 2010/06/26 07:23:57 pgoyette 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 module_t *module_newmodule(modsrc_t); 91 static void module_require_force(module_t *); 92 static int module_do_load(const char *, bool, int, prop_dictionary_t, 93 module_t **, modclass_t class, bool); 94 static int module_do_unload(const char *, bool); 95 static int module_do_builtin(const char *, module_t **); 96 static int module_fetch_info(module_t *); 97 static void module_thread(void *); 98 99 static module_t *module_lookup(const char *); 100 static void module_enqueue(module_t *); 101 102 static bool module_merge_dicts(prop_dictionary_t, const prop_dictionary_t); 103 104 static void sysctl_module_setup(void); 105 106 /* 107 * module_error: 108 * 109 * Utility function: log an error. 110 */ 111 void 112 module_error(const char *fmt, ...) 113 { 114 va_list ap; 115 116 va_start(ap, fmt); 117 printf("WARNING: module error: "); 118 vprintf(fmt, ap); 119 printf("\n"); 120 va_end(ap); 121 } 122 123 /* 124 * module_print: 125 * 126 * Utility function: log verbose output. 127 */ 128 void 129 module_print(const char *fmt, ...) 130 { 131 va_list ap; 132 133 if (module_verbose_on) { 134 va_start(ap, fmt); 135 printf("DEBUG: module: "); 136 vprintf(fmt, ap); 137 printf("\n"); 138 va_end(ap); 139 } 140 } 141 142 static int 143 module_listener_cb(kauth_cred_t cred, kauth_action_t action, void *cookie, 144 void *arg0, void *arg1, void *arg2, void *arg3) 145 { 146 int result; 147 148 result = KAUTH_RESULT_DEFER; 149 150 if (action != KAUTH_SYSTEM_MODULE) 151 return result; 152 153 if ((uintptr_t)arg2 != 0) /* autoload */ 154 result = KAUTH_RESULT_ALLOW; 155 156 return result; 157 } 158 159 /* 160 * Allocate a new module_t 161 */ 162 static module_t * 163 module_newmodule(modsrc_t source) 164 { 165 module_t *mod; 166 167 mod = kmem_zalloc(sizeof(*mod), KM_SLEEP); 168 if (mod != NULL) { 169 mod->mod_source = source; 170 mod->mod_info = NULL; 171 mod->mod_flags = 0; 172 } 173 return mod; 174 } 175 176 /* 177 * Require the -f (force) flag to load a module 178 */ 179 static void 180 module_require_force(struct module *mod) 181 { 182 mod->mod_flags |= MODFLG_MUST_FORCE; 183 } 184 185 /* 186 * Add modules to the builtin list. This can done at boottime or 187 * at runtime if the module is linked into the kernel with an 188 * external linker. All or none of the input will be handled. 189 * Optionally, the modules can be initialized. If they are not 190 * initialized, module_init_class() or module_load() can be used 191 * later, but these are not guaranteed to give atomic results. 192 */ 193 int 194 module_builtin_add(modinfo_t *const *mip, size_t nmodinfo, bool init) 195 { 196 struct module **modp = NULL, *mod_iter; 197 int rv = 0, i, mipskip; 198 199 if (init) { 200 rv = kauth_authorize_system(kauth_cred_get(), 201 KAUTH_SYSTEM_MODULE, 0, (void *)(uintptr_t)MODCTL_LOAD, 202 (void *)(uintptr_t)1, NULL); 203 if (rv) { 204 return rv; 205 } 206 } 207 208 for (i = 0, mipskip = 0; i < nmodinfo; i++) { 209 if (mip[i] == &module_dummy) { 210 KASSERT(nmodinfo > 0); 211 nmodinfo--; 212 } 213 } 214 if (nmodinfo == 0) 215 return 0; 216 217 modp = kmem_zalloc(sizeof(*modp) * nmodinfo, KM_SLEEP); 218 for (i = 0, mipskip = 0; i < nmodinfo; i++) { 219 if (mip[i+mipskip] == &module_dummy) { 220 mipskip++; 221 continue; 222 } 223 modp[i] = module_newmodule(MODULE_SOURCE_KERNEL); 224 modp[i]->mod_info = mip[i+mipskip]; 225 } 226 mutex_enter(&module_lock); 227 228 /* do this in three stages for error recovery and atomicity */ 229 230 /* first check for presence */ 231 for (i = 0; i < nmodinfo; i++) { 232 TAILQ_FOREACH(mod_iter, &module_builtins, mod_chain) { 233 if (strcmp(mod_iter->mod_info->mi_name, 234 modp[i]->mod_info->mi_name) == 0) 235 break; 236 } 237 if (mod_iter) { 238 rv = EEXIST; 239 goto out; 240 } 241 242 if (module_lookup(modp[i]->mod_info->mi_name) != NULL) { 243 rv = EEXIST; 244 goto out; 245 } 246 } 247 248 /* then add to list */ 249 for (i = 0; i < nmodinfo; i++) { 250 TAILQ_INSERT_TAIL(&module_builtins, modp[i], mod_chain); 251 module_builtinlist++; 252 } 253 254 /* finally, init (if required) */ 255 if (init) { 256 for (i = 0; i < nmodinfo; i++) { 257 rv = module_do_builtin(modp[i]->mod_info->mi_name,NULL); 258 /* throw in the towel, recovery hard & not worth it */ 259 if (rv) 260 panic("builtin module \"%s\" init failed: %d", 261 modp[i]->mod_info->mi_name, rv); 262 } 263 } 264 265 out: 266 mutex_exit(&module_lock); 267 if (rv != 0) { 268 for (i = 0; i < nmodinfo; i++) { 269 if (modp[i]) 270 kmem_free(modp[i], sizeof(*modp[i])); 271 } 272 } 273 kmem_free(modp, sizeof(*modp) * nmodinfo); 274 return rv; 275 } 276 277 /* 278 * Optionally fini and remove builtin module from the kernel. 279 * Note: the module will now be unreachable except via mi && builtin_add. 280 */ 281 int 282 module_builtin_remove(modinfo_t *mi, bool fini) 283 { 284 struct module *mod; 285 int rv = 0; 286 287 if (fini) { 288 rv = kauth_authorize_system(kauth_cred_get(), 289 KAUTH_SYSTEM_MODULE, 0, (void *)(uintptr_t)MODCTL_UNLOAD, 290 NULL, NULL); 291 if (rv) 292 return rv; 293 294 mutex_enter(&module_lock); 295 rv = module_do_unload(mi->mi_name, true); 296 if (rv) { 297 goto out; 298 } 299 } else { 300 mutex_enter(&module_lock); 301 } 302 TAILQ_FOREACH(mod, &module_builtins, mod_chain) { 303 if (strcmp(mod->mod_info->mi_name, mi->mi_name) == 0) 304 break; 305 } 306 if (mod) { 307 TAILQ_REMOVE(&module_builtins, mod, mod_chain); 308 module_builtinlist--; 309 } else { 310 KASSERT(fini == false); 311 rv = ENOENT; 312 } 313 314 out: 315 mutex_exit(&module_lock); 316 return rv; 317 } 318 319 /* 320 * module_init: 321 * 322 * Initialize the module subsystem. 323 */ 324 void 325 module_init(void) 326 { 327 __link_set_decl(modules, modinfo_t); 328 extern struct vm_map *module_map; 329 modinfo_t *const *mip; 330 int rv; 331 332 if (module_map == NULL) { 333 module_map = kernel_map; 334 } 335 mutex_init(&module_lock, MUTEX_DEFAULT, IPL_NONE); 336 cv_init(&module_thread_cv, "modunload"); 337 mutex_init(&module_thread_lock, MUTEX_DEFAULT, IPL_NONE); 338 339 #ifdef MODULAR /* XXX */ 340 module_init_md(); 341 #endif 342 343 #if __NetBSD_Version__ / 1000000 % 100 == 99 /* -current */ 344 snprintf(module_base, sizeof(module_base), "/stand/%s/%s/modules", 345 machine, osrelease); 346 #else /* release */ 347 snprintf(module_base, sizeof(module_base), "/stand/%s/%d.%d/modules", 348 machine, __NetBSD_Version__ / 100000000, 349 __NetBSD_Version__ / 1000000 % 100); 350 #endif 351 352 module_listener = kauth_listen_scope(KAUTH_SCOPE_SYSTEM, 353 module_listener_cb, NULL); 354 355 __link_set_foreach(mip, modules) { 356 if ((rv = module_builtin_add(mip, 1, false) != 0)) 357 module_error("builtin %s failed: %d\n", 358 (*mip)->mi_name, rv); 359 } 360 361 sysctl_module_setup(); 362 } 363 364 /* 365 * module_start_unload_thread: 366 * 367 * Start the auto unload kthread. 368 */ 369 void 370 module_start_unload_thread(void) 371 { 372 int error; 373 374 error = kthread_create(PRI_VM, KTHREAD_MPSAFE, NULL, module_thread, 375 NULL, NULL, "modunload"); 376 if (error != 0) 377 panic("module_init: %d", error); 378 } 379 380 /* 381 * module_builtin_require_force 382 * 383 * Require MODCTL_MUST_FORCE to load any built-in modules that have 384 * not yet been initialized 385 */ 386 void 387 module_builtin_require_force(void) 388 { 389 module_t *mod; 390 391 mutex_enter(&module_lock); 392 TAILQ_FOREACH(mod, &module_builtins, mod_chain) { 393 module_require_force(mod); 394 } 395 mutex_exit(&module_lock); 396 } 397 398 static struct sysctllog *module_sysctllog; 399 400 static void 401 sysctl_module_setup(void) 402 { 403 const struct sysctlnode *node = NULL; 404 405 sysctl_createv(&module_sysctllog, 0, NULL, NULL, 406 CTLFLAG_PERMANENT, 407 CTLTYPE_NODE, "kern", NULL, 408 NULL, 0, NULL, 0, 409 CTL_KERN, CTL_EOL); 410 sysctl_createv(&module_sysctllog, 0, NULL, &node, 411 CTLFLAG_PERMANENT, 412 CTLTYPE_NODE, "module", 413 SYSCTL_DESCR("Module options"), 414 NULL, 0, NULL, 0, 415 CTL_KERN, CTL_CREATE, CTL_EOL); 416 417 if (node == NULL) 418 return; 419 420 sysctl_createv(&module_sysctllog, 0, &node, NULL, 421 CTLFLAG_PERMANENT | CTLFLAG_READWRITE, 422 CTLTYPE_BOOL, "autoload", 423 SYSCTL_DESCR("Enable automatic load of modules"), 424 NULL, 0, &module_autoload_on, 0, 425 CTL_CREATE, CTL_EOL); 426 sysctl_createv(&module_sysctllog, 0, &node, NULL, 427 CTLFLAG_PERMANENT | CTLFLAG_READWRITE, 428 CTLTYPE_BOOL, "verbose", 429 SYSCTL_DESCR("Enable verbose output"), 430 NULL, 0, &module_verbose_on, 0, 431 CTL_CREATE, CTL_EOL); 432 } 433 434 /* 435 * module_init_class: 436 * 437 * Initialize all built-in and pre-loaded modules of the 438 * specified class. 439 */ 440 void 441 module_init_class(modclass_t class) 442 { 443 TAILQ_HEAD(, module) bi_fail = TAILQ_HEAD_INITIALIZER(bi_fail); 444 module_t *mod; 445 modinfo_t *mi; 446 447 mutex_enter(&module_lock); 448 /* 449 * Builtins first. These will not depend on pre-loaded modules 450 * (because the kernel would not link). 451 */ 452 do { 453 TAILQ_FOREACH(mod, &module_builtins, mod_chain) { 454 mi = mod->mod_info; 455 if (class != MODULE_CLASS_ANY && class != mi->mi_class) 456 continue; 457 /* 458 * If initializing a builtin module fails, don't try 459 * to load it again. But keep it around and queue it 460 * on the builtins list after we're done with module 461 * init. Don't set it to MODFLG_MUST_FORCE in case a 462 * future attempt to initialize can be successful. 463 * (If the module has previously been set to 464 * MODFLG_MUST_FORCE, don't try to override that!) 465 */ 466 if (mod->mod_flags & MODFLG_MUST_FORCE || 467 module_do_builtin(mi->mi_name, NULL) != 0) { 468 TAILQ_REMOVE(&module_builtins, mod, mod_chain); 469 TAILQ_INSERT_TAIL(&bi_fail, mod, mod_chain); 470 } 471 break; 472 } 473 } while (mod != NULL); 474 475 /* 476 * Now preloaded modules. These will be pulled off the 477 * list as we call module_do_load(); 478 */ 479 do { 480 TAILQ_FOREACH(mod, &module_bootlist, mod_chain) { 481 mi = mod->mod_info; 482 if (class != MODULE_CLASS_ANY && class != mi->mi_class) 483 continue; 484 module_do_load(mi->mi_name, false, 0, NULL, NULL, 485 class, false); 486 break; 487 } 488 } while (mod != NULL); 489 490 /* return failed builtin modules to builtin list */ 491 while ((mod = TAILQ_FIRST(&bi_fail)) != NULL) { 492 TAILQ_REMOVE(&bi_fail, mod, mod_chain); 493 TAILQ_INSERT_TAIL(&module_builtins, mod, mod_chain); 494 } 495 496 mutex_exit(&module_lock); 497 } 498 499 /* 500 * module_compatible: 501 * 502 * Return true if the two supplied kernel versions are said to 503 * have the same binary interface for kernel code. The entire 504 * version is signficant for the development tree (-current), 505 * major and minor versions are significant for official 506 * releases of the system. 507 */ 508 bool 509 module_compatible(int v1, int v2) 510 { 511 512 #if __NetBSD_Version__ / 1000000 % 100 == 99 /* -current */ 513 return v1 == v2; 514 #else /* release */ 515 return abs(v1 - v2) < 10000; 516 #endif 517 } 518 519 /* 520 * module_load: 521 * 522 * Load a single module from the file system. 523 */ 524 int 525 module_load(const char *filename, int flags, prop_dictionary_t props, 526 modclass_t class) 527 { 528 int error; 529 530 /* Authorize. */ 531 error = kauth_authorize_system(kauth_cred_get(), KAUTH_SYSTEM_MODULE, 532 0, (void *)(uintptr_t)MODCTL_LOAD, NULL, NULL); 533 if (error != 0) { 534 return error; 535 } 536 537 mutex_enter(&module_lock); 538 error = module_do_load(filename, false, flags, props, NULL, class, 539 false); 540 mutex_exit(&module_lock); 541 542 return error; 543 } 544 545 /* 546 * module_autoload: 547 * 548 * Load a single module from the file system, system initiated. 549 */ 550 int 551 module_autoload(const char *filename, modclass_t class) 552 { 553 int error; 554 555 KASSERT(mutex_owned(&module_lock)); 556 557 /* Nothing if the user has disabled it. */ 558 if (!module_autoload_on) { 559 return EPERM; 560 } 561 562 /* Disallow path separators and magic symlinks. */ 563 if (strchr(filename, '/') != NULL || strchr(filename, '@') != NULL || 564 strchr(filename, '.') != NULL) { 565 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 if (error != 0) { 572 return error; 573 } 574 575 return module_do_load(filename, false, 0, NULL, NULL, class, true); 576 } 577 578 /* 579 * module_unload: 580 * 581 * Find and unload a module by name. 582 */ 583 int 584 module_unload(const char *name) 585 { 586 int error; 587 588 /* Authorize. */ 589 error = kauth_authorize_system(kauth_cred_get(), KAUTH_SYSTEM_MODULE, 590 0, (void *)(uintptr_t)MODCTL_UNLOAD, NULL, NULL); 591 if (error != 0) { 592 return error; 593 } 594 595 mutex_enter(&module_lock); 596 error = module_do_unload(name, true); 597 mutex_exit(&module_lock); 598 599 return error; 600 } 601 602 /* 603 * module_lookup: 604 * 605 * Look up a module by name. 606 */ 607 module_t * 608 module_lookup(const char *name) 609 { 610 module_t *mod; 611 612 KASSERT(mutex_owned(&module_lock)); 613 614 TAILQ_FOREACH(mod, &module_list, mod_chain) { 615 if (strcmp(mod->mod_info->mi_name, name) == 0) { 616 break; 617 } 618 } 619 620 return mod; 621 } 622 623 /* 624 * module_hold: 625 * 626 * Add a single reference to a module. It's the caller's 627 * responsibility to ensure that the reference is dropped 628 * later. 629 */ 630 int 631 module_hold(const char *name) 632 { 633 module_t *mod; 634 635 mutex_enter(&module_lock); 636 mod = module_lookup(name); 637 if (mod == NULL) { 638 mutex_exit(&module_lock); 639 return ENOENT; 640 } 641 mod->mod_refcnt++; 642 mutex_exit(&module_lock); 643 644 return 0; 645 } 646 647 /* 648 * module_rele: 649 * 650 * Release a reference acquired with module_hold(). 651 */ 652 void 653 module_rele(const char *name) 654 { 655 module_t *mod; 656 657 mutex_enter(&module_lock); 658 mod = module_lookup(name); 659 if (mod == NULL) { 660 mutex_exit(&module_lock); 661 panic("module_rele: gone"); 662 } 663 mod->mod_refcnt--; 664 mutex_exit(&module_lock); 665 } 666 667 /* 668 * module_enqueue: 669 * 670 * Put a module onto the global list and update counters. 671 */ 672 void 673 module_enqueue(module_t *mod) 674 { 675 int i; 676 677 KASSERT(mutex_owned(&module_lock)); 678 679 /* 680 * If there are requisite modules, put at the head of the queue. 681 * This is so that autounload can unload requisite modules with 682 * only one pass through the queue. 683 */ 684 if (mod->mod_nrequired) { 685 TAILQ_INSERT_HEAD(&module_list, mod, mod_chain); 686 687 /* Add references to the requisite modules. */ 688 for (i = 0; i < mod->mod_nrequired; i++) { 689 KASSERT(mod->mod_required[i] != NULL); 690 mod->mod_required[i]->mod_refcnt++; 691 } 692 } else { 693 TAILQ_INSERT_TAIL(&module_list, mod, mod_chain); 694 } 695 module_count++; 696 module_gen++; 697 } 698 699 /* 700 * module_do_builtin: 701 * 702 * Initialize a module from the list of modules that are 703 * already linked into the kernel. 704 */ 705 static int 706 module_do_builtin(const char *name, module_t **modp) 707 { 708 const char *p, *s; 709 char buf[MAXMODNAME]; 710 modinfo_t *mi = NULL; 711 module_t *mod, *mod2, *mod_loaded; 712 size_t len; 713 int error; 714 715 KASSERT(mutex_owned(&module_lock)); 716 717 /* 718 * Search the list to see if we have a module by this name. 719 */ 720 TAILQ_FOREACH(mod, &module_builtins, mod_chain) { 721 if (strcmp(mod->mod_info->mi_name, name) == 0) { 722 mi = mod->mod_info; 723 break; 724 } 725 } 726 727 /* 728 * Check to see if already loaded. This might happen if we 729 * were already loaded as a dependency. 730 */ 731 if ((mod_loaded = module_lookup(name)) != NULL) { 732 KASSERT(mod == NULL); 733 if (modp) 734 *modp = mod_loaded; 735 return 0; 736 } 737 738 /* Note! This is from TAILQ, not immediate above */ 739 if (mi == NULL) { 740 /* 741 * XXX: We'd like to panic here, but currently in some 742 * cases (such as nfsserver + nfs), the dependee can be 743 * succesfully linked without the dependencies. 744 */ 745 module_error("can't find builtin dependency `%s'", name); 746 return ENOENT; 747 } 748 749 /* 750 * Initialize pre-requisites. 751 */ 752 if (mi->mi_required != NULL) { 753 for (s = mi->mi_required; *s != '\0'; s = p) { 754 if (*s == ',') 755 s++; 756 p = s; 757 while (*p != '\0' && *p != ',') 758 p++; 759 len = min(p - s + 1, sizeof(buf)); 760 strlcpy(buf, s, len); 761 if (buf[0] == '\0') 762 break; 763 if (mod->mod_nrequired == MAXMODDEPS - 1) { 764 module_error("too many required modules"); 765 return EINVAL; 766 } 767 error = module_do_builtin(buf, &mod2); 768 if (error != 0) { 769 return error; 770 } 771 mod->mod_required[mod->mod_nrequired++] = mod2; 772 } 773 } 774 775 /* 776 * Try to initialize the module. 777 */ 778 KASSERT(module_active == NULL); 779 module_active = mod; 780 error = (*mi->mi_modcmd)(MODULE_CMD_INIT, NULL); 781 module_active = NULL; 782 if (error != 0) { 783 module_error("builtin module `%s' " 784 "failed to init", mi->mi_name); 785 return error; 786 } 787 788 /* load always succeeds after this point */ 789 790 TAILQ_REMOVE(&module_builtins, mod, mod_chain); 791 module_builtinlist--; 792 if (modp != NULL) { 793 *modp = mod; 794 } 795 if (mi->mi_class == MODULE_CLASS_SECMODEL) 796 secmodel_register(); 797 module_enqueue(mod); 798 return 0; 799 } 800 801 /* 802 * module_do_load: 803 * 804 * Helper routine: load a module from the file system, or one 805 * pushed by the boot loader. 806 */ 807 static int 808 module_do_load(const char *name, bool isdep, int flags, 809 prop_dictionary_t props, module_t **modp, modclass_t class, 810 bool autoload) 811 { 812 static TAILQ_HEAD(,module) pending = TAILQ_HEAD_INITIALIZER(pending); 813 static int depth; 814 const int maxdepth = 6; 815 modinfo_t *mi; 816 module_t *mod, *mod2; 817 prop_dictionary_t filedict; 818 char buf[MAXMODNAME]; 819 const char *s, *p; 820 int error; 821 size_t len; 822 823 KASSERT(mutex_owned(&module_lock)); 824 825 filedict = NULL; 826 error = 0; 827 828 /* 829 * Avoid recursing too far. 830 */ 831 if (++depth > maxdepth) { 832 module_error("too many required modules"); 833 depth--; 834 return EMLINK; 835 } 836 837 /* 838 * Search the list of disabled builtins first. 839 */ 840 TAILQ_FOREACH(mod, &module_builtins, mod_chain) { 841 if (strcmp(mod->mod_info->mi_name, name) == 0) { 842 break; 843 } 844 } 845 if (mod) { 846 if ((mod->mod_flags & MODFLG_MUST_FORCE) && 847 (flags & MODCTL_LOAD_FORCE) == 0) { 848 if (!autoload) { 849 module_error("use -f to reinstate " 850 "builtin module \"%s\"", name); 851 } 852 depth--; 853 return EPERM; 854 } else { 855 error = module_do_builtin(name, NULL); 856 depth--; 857 return error; 858 } 859 } 860 861 /* 862 * Load the module and link. Before going to the file system, 863 * scan the list of modules loaded by the boot loader. 864 */ 865 TAILQ_FOREACH(mod, &module_bootlist, mod_chain) { 866 if (strcmp(mod->mod_info->mi_name, name) == 0) { 867 TAILQ_REMOVE(&module_bootlist, mod, mod_chain); 868 break; 869 } 870 } 871 if (mod != NULL) { 872 TAILQ_INSERT_TAIL(&pending, mod, mod_chain); 873 } else { 874 /* 875 * If a requisite module, check to see if it is 876 * already present. 877 */ 878 if (isdep) { 879 TAILQ_FOREACH(mod, &module_list, mod_chain) { 880 if (strcmp(mod->mod_info->mi_name, name) == 0) { 881 break; 882 } 883 } 884 if (mod != NULL) { 885 if (modp != NULL) { 886 *modp = mod; 887 } 888 depth--; 889 return 0; 890 } 891 } 892 mod = module_newmodule(MODULE_SOURCE_FILESYS); 893 if (mod == NULL) { 894 module_error("out of memory for `%s'", name); 895 depth--; 896 return ENOMEM; 897 } 898 899 error = module_load_vfs_vec(name, flags, autoload, mod, 900 &filedict); 901 if (error != 0) { 902 kmem_free(mod, sizeof(*mod)); 903 depth--; 904 return error; 905 } 906 TAILQ_INSERT_TAIL(&pending, mod, mod_chain); 907 908 error = module_fetch_info(mod); 909 if (error != 0) { 910 module_error("cannot fetch module info for `%s'", 911 name); 912 goto fail; 913 } 914 } 915 916 /* 917 * Check compatibility. 918 */ 919 mi = mod->mod_info; 920 if (strlen(mi->mi_name) >= MAXMODNAME) { 921 error = EINVAL; 922 module_error("module name `%s' too long", mi->mi_name); 923 goto fail; 924 } 925 if (!module_compatible(mi->mi_version, __NetBSD_Version__)) { 926 module_error("module built for `%d', system `%d'", 927 mi->mi_version, __NetBSD_Version__); 928 if ((flags & MODCTL_LOAD_FORCE) != 0) { 929 module_error("forced load, system may be unstable"); 930 } else { 931 error = EPROGMISMATCH; 932 goto fail; 933 } 934 } 935 936 /* 937 * If a specific kind of module was requested, ensure that we have 938 * a match. 939 */ 940 if (class != MODULE_CLASS_ANY && class != mi->mi_class) { 941 module_print("incompatible module class for `%s' (%d != %d)", 942 name, class, mi->mi_class); 943 error = ENOENT; 944 goto fail; 945 } 946 947 /* 948 * If loading a dependency, `name' is a plain module name. 949 * The name must match. 950 */ 951 if (isdep && strcmp(mi->mi_name, name) != 0) { 952 module_error("dependency name mismatch (`%s' != `%s')", 953 name, mi->mi_name); 954 error = ENOENT; 955 goto fail; 956 } 957 958 /* 959 * Check to see if the module is already loaded. If so, we may 960 * have been recursively called to handle a dependency, so be sure 961 * to set modp. 962 */ 963 if ((mod2 = module_lookup(mi->mi_name)) != NULL) { 964 if (modp != NULL) 965 *modp = mod2; 966 module_print("module `%s' already loaded", mi->mi_name); 967 error = EEXIST; 968 goto fail; 969 } 970 971 /* 972 * Block circular dependencies. 973 */ 974 TAILQ_FOREACH(mod2, &pending, mod_chain) { 975 if (mod == mod2) { 976 continue; 977 } 978 if (strcmp(mod2->mod_info->mi_name, mi->mi_name) == 0) { 979 error = EDEADLK; 980 module_error("circular dependency detected for `%s'", 981 mi->mi_name); 982 goto fail; 983 } 984 } 985 986 /* 987 * Now try to load any requisite modules. 988 */ 989 if (mi->mi_required != NULL) { 990 for (s = mi->mi_required; *s != '\0'; s = p) { 991 if (*s == ',') 992 s++; 993 p = s; 994 while (*p != '\0' && *p != ',') 995 p++; 996 len = p - s + 1; 997 if (len >= MAXMODNAME) { 998 error = EINVAL; 999 module_error("required module name `%s'" 1000 " too long", mi->mi_required); 1001 goto fail; 1002 } 1003 strlcpy(buf, s, len); 1004 if (buf[0] == '\0') 1005 break; 1006 if (mod->mod_nrequired == MAXMODDEPS - 1) { 1007 error = EINVAL; 1008 module_error("too many required modules (%d)", 1009 mod->mod_nrequired); 1010 goto fail; 1011 } 1012 if (strcmp(buf, mi->mi_name) == 0) { 1013 error = EDEADLK; 1014 module_error("self-dependency detected for " 1015 "`%s'", mi->mi_name); 1016 goto fail; 1017 } 1018 error = module_do_load(buf, true, flags, NULL, 1019 &mod->mod_required[mod->mod_nrequired++], 1020 MODULE_CLASS_ANY, true); 1021 if (error != 0) 1022 goto fail; 1023 } 1024 } 1025 1026 /* 1027 * We loaded all needed modules successfully: perform global 1028 * relocations and initialize. 1029 */ 1030 error = kobj_affix(mod->mod_kobj, mi->mi_name); 1031 if (error != 0) { 1032 /* Cannot touch 'mi' as the module is now gone. */ 1033 module_error("unable to affix module `%s'", name); 1034 goto fail2; 1035 } 1036 1037 if (filedict) { 1038 if (!module_merge_dicts(filedict, props)) { 1039 module_error("module properties failed"); 1040 error = EINVAL; 1041 goto fail; 1042 } 1043 } 1044 KASSERT(module_active == NULL); 1045 module_active = mod; 1046 error = (*mi->mi_modcmd)(MODULE_CMD_INIT, filedict ? filedict : props); 1047 module_active = NULL; 1048 if (filedict) { 1049 prop_object_release(filedict); 1050 filedict = NULL; 1051 } 1052 if (error != 0) { 1053 module_error("modcmd function returned error %d for `%s'", 1054 error, mi->mi_name); 1055 goto fail; 1056 } 1057 1058 if (mi->mi_class == MODULE_CLASS_SECMODEL) 1059 secmodel_register(); 1060 1061 /* 1062 * Good, the module loaded successfully. Put it onto the 1063 * list and add references to its requisite modules. 1064 */ 1065 TAILQ_REMOVE(&pending, mod, mod_chain); 1066 module_enqueue(mod); 1067 if (modp != NULL) { 1068 *modp = mod; 1069 } 1070 if (autoload) { 1071 /* 1072 * Arrange to try unloading the module after 1073 * a short delay. 1074 */ 1075 mod->mod_autotime = time_second + module_autotime; 1076 module_thread_kick(); 1077 } 1078 depth--; 1079 return 0; 1080 1081 fail: 1082 kobj_unload(mod->mod_kobj); 1083 fail2: 1084 if (filedict != NULL) { 1085 prop_object_release(filedict); 1086 filedict = NULL; 1087 } 1088 TAILQ_REMOVE(&pending, mod, mod_chain); 1089 kmem_free(mod, sizeof(*mod)); 1090 depth--; 1091 return error; 1092 } 1093 1094 /* 1095 * module_do_unload: 1096 * 1097 * Helper routine: do the dirty work of unloading a module. 1098 */ 1099 static int 1100 module_do_unload(const char *name, bool load_requires_force) 1101 { 1102 module_t *mod; 1103 int error; 1104 u_int i; 1105 1106 KASSERT(mutex_owned(&module_lock)); 1107 1108 mod = module_lookup(name); 1109 if (mod == NULL) { 1110 module_error("module `%s' not found", name); 1111 return ENOENT; 1112 } 1113 if (mod->mod_refcnt != 0) { 1114 module_print("module `%s' busy", name); 1115 return EBUSY; 1116 } 1117 KASSERT(module_active == NULL); 1118 module_active = mod; 1119 error = (*mod->mod_info->mi_modcmd)(MODULE_CMD_FINI, NULL); 1120 module_active = NULL; 1121 if (error != 0) { 1122 module_print("cannot unload module `%s' error=%d", name, 1123 error); 1124 return error; 1125 } 1126 if (mod->mod_info->mi_class == MODULE_CLASS_SECMODEL) 1127 secmodel_deregister(); 1128 module_count--; 1129 TAILQ_REMOVE(&module_list, mod, mod_chain); 1130 for (i = 0; i < mod->mod_nrequired; i++) { 1131 mod->mod_required[i]->mod_refcnt--; 1132 } 1133 if (mod->mod_kobj != NULL) { 1134 kobj_unload(mod->mod_kobj); 1135 } 1136 if (mod->mod_source == MODULE_SOURCE_KERNEL) { 1137 mod->mod_nrequired = 0; /* will be re-parsed */ 1138 if (load_requires_force) 1139 module_require_force(mod); 1140 TAILQ_INSERT_TAIL(&module_builtins, mod, mod_chain); 1141 module_builtinlist++; 1142 } else { 1143 kmem_free(mod, sizeof(*mod)); 1144 } 1145 module_gen++; 1146 1147 return 0; 1148 } 1149 1150 /* 1151 * module_prime: 1152 * 1153 * Push a module loaded by the bootloader onto our internal 1154 * list. 1155 */ 1156 int 1157 module_prime(void *base, size_t size) 1158 { 1159 module_t *mod; 1160 int error; 1161 1162 mod = module_newmodule(MODULE_SOURCE_BOOT); 1163 if (mod == NULL) { 1164 return ENOMEM; 1165 } 1166 1167 error = kobj_load_mem(&mod->mod_kobj, base, size); 1168 if (error != 0) { 1169 kmem_free(mod, sizeof(*mod)); 1170 module_error("unable to load object pushed by boot loader"); 1171 return error; 1172 } 1173 error = module_fetch_info(mod); 1174 if (error != 0) { 1175 kobj_unload(mod->mod_kobj); 1176 kmem_free(mod, sizeof(*mod)); 1177 module_error("unable to load object pushed by boot loader"); 1178 return error; 1179 } 1180 1181 TAILQ_INSERT_TAIL(&module_bootlist, mod, mod_chain); 1182 1183 return 0; 1184 } 1185 1186 /* 1187 * module_fetch_into: 1188 * 1189 * Fetch modinfo record from a loaded module. 1190 */ 1191 static int 1192 module_fetch_info(module_t *mod) 1193 { 1194 int error; 1195 void *addr; 1196 size_t size; 1197 1198 /* 1199 * Find module info record and check compatibility. 1200 */ 1201 error = kobj_find_section(mod->mod_kobj, "link_set_modules", 1202 &addr, &size); 1203 if (error != 0) { 1204 module_error("`link_set_modules' section not present"); 1205 return error; 1206 } 1207 if (size != sizeof(modinfo_t **)) { 1208 module_error("`link_set_modules' section wrong size"); 1209 return error; 1210 } 1211 mod->mod_info = *(modinfo_t **)addr; 1212 1213 return 0; 1214 } 1215 1216 /* 1217 * module_find_section: 1218 * 1219 * Allows a module that is being initialized to look up a section 1220 * within its ELF object. 1221 */ 1222 int 1223 module_find_section(const char *name, void **addr, size_t *size) 1224 { 1225 1226 KASSERT(mutex_owned(&module_lock)); 1227 KASSERT(module_active != NULL); 1228 1229 return kobj_find_section(module_active->mod_kobj, name, addr, size); 1230 } 1231 1232 /* 1233 * module_thread: 1234 * 1235 * Automatically unload modules. We try once to unload autoloaded 1236 * modules after module_autotime seconds. If the system is under 1237 * severe memory pressure, we'll try unloading all modules. 1238 */ 1239 static void 1240 module_thread(void *cookie) 1241 { 1242 module_t *mod, *next; 1243 modinfo_t *mi; 1244 int error; 1245 1246 for (;;) { 1247 mutex_enter(&module_lock); 1248 for (mod = TAILQ_FIRST(&module_list); mod != NULL; mod = next) { 1249 next = TAILQ_NEXT(mod, mod_chain); 1250 if (mod->mod_source == MODULE_SOURCE_KERNEL) 1251 continue; 1252 if (uvmexp.free < uvmexp.freemin) { 1253 module_thread_ticks = hz; 1254 } else if (mod->mod_autotime == 0) { 1255 continue; 1256 } else if (time_second < mod->mod_autotime) { 1257 module_thread_ticks = hz; 1258 continue; 1259 } else { 1260 mod->mod_autotime = 0; 1261 } 1262 /* 1263 * If this module wants to avoid autounload then 1264 * skip it. Some modules can ping-pong in and out 1265 * because their use is transient but often. 1266 * Example: exec_script. 1267 */ 1268 mi = mod->mod_info; 1269 error = (*mi->mi_modcmd)(MODULE_CMD_AUTOUNLOAD, NULL); 1270 if (error == 0 || error == ENOTTY) { 1271 (void)module_do_unload(mi->mi_name, false); 1272 } 1273 } 1274 mutex_exit(&module_lock); 1275 1276 mutex_enter(&module_thread_lock); 1277 (void)cv_timedwait(&module_thread_cv, &module_thread_lock, 1278 module_thread_ticks); 1279 module_thread_ticks = 0; 1280 mutex_exit(&module_thread_lock); 1281 } 1282 } 1283 1284 /* 1285 * module_thread: 1286 * 1287 * Kick the module thread into action, perhaps because the 1288 * system is low on memory. 1289 */ 1290 void 1291 module_thread_kick(void) 1292 { 1293 1294 mutex_enter(&module_thread_lock); 1295 module_thread_ticks = hz; 1296 cv_broadcast(&module_thread_cv); 1297 mutex_exit(&module_thread_lock); 1298 } 1299 1300 #ifdef DDB 1301 /* 1302 * module_whatis: 1303 * 1304 * Helper routine for DDB. 1305 */ 1306 void 1307 module_whatis(uintptr_t addr, void (*pr)(const char *, ...)) 1308 { 1309 module_t *mod; 1310 size_t msize; 1311 vaddr_t maddr; 1312 1313 TAILQ_FOREACH(mod, &module_list, mod_chain) { 1314 if (mod->mod_kobj == NULL) { 1315 continue; 1316 } 1317 if (kobj_stat(mod->mod_kobj, &maddr, &msize) != 0) 1318 continue; 1319 if (addr < maddr || addr >= maddr + msize) { 1320 continue; 1321 } 1322 (*pr)("%p is %p+%zu, in kernel module `%s'\n", 1323 (void *)addr, (void *)maddr, 1324 (size_t)(addr - maddr), mod->mod_info->mi_name); 1325 } 1326 } 1327 1328 /* 1329 * module_print_list: 1330 * 1331 * Helper routine for DDB. 1332 */ 1333 void 1334 module_print_list(void (*pr)(const char *, ...)) 1335 { 1336 const char *src; 1337 module_t *mod; 1338 size_t msize; 1339 vaddr_t maddr; 1340 1341 (*pr)("%16s %16s %8s %8s\n", "NAME", "TEXT/DATA", "SIZE", "SOURCE"); 1342 1343 TAILQ_FOREACH(mod, &module_list, mod_chain) { 1344 switch (mod->mod_source) { 1345 case MODULE_SOURCE_KERNEL: 1346 src = "builtin"; 1347 break; 1348 case MODULE_SOURCE_FILESYS: 1349 src = "filesys"; 1350 break; 1351 case MODULE_SOURCE_BOOT: 1352 src = "boot"; 1353 break; 1354 default: 1355 src = "unknown"; 1356 break; 1357 } 1358 if (mod->mod_kobj == NULL) { 1359 maddr = 0; 1360 msize = 0; 1361 } else if (kobj_stat(mod->mod_kobj, &maddr, &msize) != 0) 1362 continue; 1363 (*pr)("%16s %16lx %8ld %8s\n", mod->mod_info->mi_name, 1364 (long)maddr, (long)msize, src); 1365 } 1366 } 1367 #endif /* DDB */ 1368 1369 static bool 1370 module_merge_dicts(prop_dictionary_t existing_dict, 1371 const prop_dictionary_t new_dict) 1372 { 1373 prop_dictionary_keysym_t props_keysym; 1374 prop_object_iterator_t props_iter; 1375 prop_object_t props_obj; 1376 const char *props_key; 1377 bool error; 1378 1379 if (new_dict == NULL) { /* nothing to merge */ 1380 return true; 1381 } 1382 1383 error = false; 1384 props_iter = prop_dictionary_iterator(new_dict); 1385 if (props_iter == NULL) { 1386 return false; 1387 } 1388 1389 while ((props_obj = prop_object_iterator_next(props_iter)) != NULL) { 1390 props_keysym = (prop_dictionary_keysym_t)props_obj; 1391 props_key = prop_dictionary_keysym_cstring_nocopy(props_keysym); 1392 props_obj = prop_dictionary_get_keysym(new_dict, props_keysym); 1393 if ((props_obj == NULL) || !prop_dictionary_set(existing_dict, 1394 props_key, props_obj)) { 1395 error = true; 1396 goto out; 1397 } 1398 } 1399 error = false; 1400 1401 out: 1402 prop_object_iterator_release(props_iter); 1403 1404 return !error; 1405 } 1406