1 /* $NetBSD: kern_module.c,v 1.42 2009/02/13 22:41:04 apb 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 1.42 2009/02/13 22:41:04 apb Exp $"); 38 39 #ifdef _KERNEL_OPT 40 #include "opt_ddb.h" 41 #include "opt_modular.h" 42 #endif 43 44 #include <sys/param.h> 45 #include <sys/systm.h> 46 #include <sys/kernel.h> 47 #include <sys/fcntl.h> 48 #include <sys/proc.h> 49 #include <sys/kauth.h> 50 #include <sys/kobj.h> 51 #include <sys/kmem.h> 52 #include <sys/module.h> 53 #include <sys/kauth.h> 54 #include <sys/kthread.h> 55 #include <sys/sysctl.h> 56 57 #include <uvm/uvm_extern.h> 58 59 #include <machine/stdarg.h> 60 61 struct vm_map *module_map; 62 63 struct modlist module_list = TAILQ_HEAD_INITIALIZER(module_list); 64 struct modlist module_bootlist = TAILQ_HEAD_INITIALIZER(module_bootlist); 65 static module_t *module_active; 66 static char module_base[64]; 67 static int module_verbose_on; 68 static int module_autoload_on = 1; 69 u_int module_count; 70 kmutex_t module_lock; 71 u_int module_autotime = 10; 72 u_int module_gen = 1; 73 static kcondvar_t module_thread_cv; 74 static kmutex_t module_thread_lock; 75 static int module_thread_ticks; 76 77 /* Ensure that the kernel's link set isn't empty. */ 78 static modinfo_t module_dummy; 79 __link_set_add_rodata(modules, module_dummy); 80 81 static module_t *module_lookup(const char *); 82 static int module_do_load(const char *, bool, int, prop_dictionary_t, 83 module_t **, modclass_t class, bool); 84 static int module_do_unload(const char *); 85 static void module_error(const char *, ...) 86 __attribute__((__format__(__printf__,1,2))); 87 static void module_print(const char *, ...) 88 __attribute__((__format__(__printf__,1,2))); 89 static int module_do_builtin(const char *, module_t **); 90 static int module_fetch_info(module_t *); 91 static void module_thread(void *); 92 93 /* 94 * module_error: 95 * 96 * Utility function: log an error. 97 */ 98 static void 99 module_error(const char *fmt, ...) 100 { 101 va_list ap; 102 103 va_start(ap, fmt); 104 printf("WARNING: module error: "); 105 vprintf(fmt, ap); 106 printf("\n"); 107 va_end(ap); 108 } 109 110 /* 111 * module_print: 112 * 113 * Utility function: log verbose output. 114 */ 115 static void 116 module_print(const char *fmt, ...) 117 { 118 va_list ap; 119 120 if (module_verbose_on) { 121 va_start(ap, fmt); 122 printf("DEBUG: module: "); 123 vprintf(fmt, ap); 124 printf("\n"); 125 va_end(ap); 126 } 127 } 128 129 /* 130 * module_init: 131 * 132 * Initialize the module subsystem. 133 */ 134 void 135 module_init(void) 136 { 137 extern struct vm_map *module_map; 138 int error; 139 140 if (module_map == NULL) { 141 module_map = kernel_map; 142 } 143 mutex_init(&module_lock, MUTEX_DEFAULT, IPL_NONE); 144 cv_init(&module_thread_cv, "modunload"); 145 mutex_init(&module_thread_lock, MUTEX_DEFAULT, IPL_NONE); 146 #ifdef MODULAR /* XXX */ 147 module_init_md(); 148 #endif 149 150 #if __NetBSD_Version__ / 1000000 % 100 == 99 /* -current */ 151 snprintf(module_base, sizeof(module_base), "/stand/%s/%s/modules", 152 machine, osrelease); 153 #else /* release */ 154 snprintf(module_base, sizeof(module_base), "/stand/%s/%d.%d/modules", 155 machine, __NetBSD_Version__ / 100000000, 156 __NetBSD_Version__ / 1000000 % 100); 157 #endif 158 159 error = kthread_create(PRI_VM, KTHREAD_MPSAFE, NULL, module_thread, 160 NULL, NULL, "modunload"); 161 if (error != 0) 162 panic("module_init: %d", error); 163 } 164 165 SYSCTL_SETUP(sysctl_module_setup, "sysctl module setup") 166 { 167 const struct sysctlnode *node = NULL; 168 169 sysctl_createv(clog, 0, NULL, NULL, 170 CTLFLAG_PERMANENT, 171 CTLTYPE_NODE, "kern", NULL, 172 NULL, 0, NULL, 0, 173 CTL_KERN, CTL_EOL); 174 sysctl_createv(clog, 0, NULL, &node, 175 CTLFLAG_PERMANENT, 176 CTLTYPE_NODE, "module", 177 SYSCTL_DESCR("Module options"), 178 NULL, 0, NULL, 0, 179 CTL_KERN, CTL_CREATE, CTL_EOL); 180 181 if (node == NULL) 182 return; 183 184 sysctl_createv(clog, 0, &node, NULL, 185 CTLFLAG_PERMANENT | CTLFLAG_READWRITE, 186 CTLTYPE_INT, "autoload", 187 SYSCTL_DESCR("Enable automatic load of modules"), 188 NULL, 0, &module_autoload_on, 0, 189 CTL_CREATE, CTL_EOL); 190 sysctl_createv(clog, 0, &node, NULL, 191 CTLFLAG_PERMANENT | CTLFLAG_READWRITE, 192 CTLTYPE_INT, "verbose", 193 SYSCTL_DESCR("Enable verbose output"), 194 NULL, 0, &module_verbose_on, 0, 195 CTL_CREATE, CTL_EOL); 196 } 197 198 /* 199 * module_init_class: 200 * 201 * Initialize all built-in and pre-loaded modules of the 202 * specified class. 203 */ 204 void 205 module_init_class(modclass_t class) 206 { 207 __link_set_decl(modules, modinfo_t); 208 modinfo_t *const *mip, *mi; 209 module_t *mod; 210 211 mutex_enter(&module_lock); 212 /* 213 * Builtins first. These can't depend on pre-loaded modules. 214 */ 215 __link_set_foreach(mip, modules) { 216 mi = *mip; 217 if (mi == &module_dummy) { 218 continue; 219 } 220 if (class != MODULE_CLASS_ANY && class != mi->mi_class) { 221 continue; 222 } 223 (void)module_do_builtin(mi->mi_name, NULL); 224 } 225 /* 226 * Now preloaded modules. These will be pulled off the 227 * list as we call module_do_load(); 228 */ 229 do { 230 TAILQ_FOREACH(mod, &module_bootlist, mod_chain) { 231 mi = mod->mod_info; 232 if (class != MODULE_CLASS_ANY && 233 class != mi->mi_class) 234 continue; 235 module_do_load(mi->mi_name, false, 0, NULL, NULL, 236 class, false); 237 break; 238 } 239 } while (mod != NULL); 240 mutex_exit(&module_lock); 241 } 242 243 /* 244 * module_compatible: 245 * 246 * Return true if the two supplied kernel versions are said to 247 * have the same binary interface for kernel code. The entire 248 * version is signficant for the development tree (-current), 249 * major and minor versions are significant for official 250 * releases of the system. 251 */ 252 bool 253 module_compatible(int v1, int v2) 254 { 255 256 #if __NetBSD_Version__ / 1000000 % 100 == 99 /* -current */ 257 return v1 == v2; 258 #else /* release */ 259 return abs(v1 - v2) < 10000; 260 #endif 261 } 262 263 /* 264 * module_load: 265 * 266 * Load a single module from the file system. 267 */ 268 int 269 module_load(const char *filename, int flags, prop_dictionary_t props, 270 modclass_t class) 271 { 272 int error; 273 274 /* Authorize. */ 275 error = kauth_authorize_system(kauth_cred_get(), KAUTH_SYSTEM_MODULE, 276 0, (void *)(uintptr_t)MODCTL_LOAD, NULL, NULL); 277 if (error != 0) { 278 return error; 279 } 280 281 mutex_enter(&module_lock); 282 error = module_do_load(filename, false, flags, props, NULL, class, 283 false); 284 mutex_exit(&module_lock); 285 286 return error; 287 } 288 289 /* 290 * module_autoload: 291 * 292 * Load a single module from the file system, system initiated. 293 */ 294 int 295 module_autoload(const char *filename, modclass_t class) 296 { 297 int error; 298 299 KASSERT(mutex_owned(&module_lock)); 300 301 /* Nothing if the user has disabled it. */ 302 if (!module_autoload_on) { 303 return EPERM; 304 } 305 306 /* Disallow path seperators and magic symlinks. */ 307 if (strchr(filename, '/') != NULL || strchr(filename, '@') != NULL || 308 strchr(filename, '.') != NULL) { 309 return EPERM; 310 } 311 312 /* Authorize. */ 313 error = kauth_authorize_system(kauth_cred_get(), KAUTH_SYSTEM_MODULE, 314 0, (void *)(uintptr_t)MODCTL_LOAD, (void *)(uintptr_t)1, NULL); 315 if (error != 0) { 316 return error; 317 } 318 319 return module_do_load(filename, false, 0, NULL, NULL, class, true); 320 } 321 322 /* 323 * module_unload: 324 * 325 * Find and unload a module by name. 326 */ 327 int 328 module_unload(const char *name) 329 { 330 int error; 331 332 /* Authorize. */ 333 error = kauth_authorize_system(kauth_cred_get(), KAUTH_SYSTEM_MODULE, 334 0, (void *)(uintptr_t)MODCTL_UNLOAD, NULL, NULL); 335 if (error != 0) { 336 return error; 337 } 338 339 mutex_enter(&module_lock); 340 error = module_do_unload(name); 341 mutex_exit(&module_lock); 342 343 return error; 344 } 345 346 /* 347 * module_lookup: 348 * 349 * Look up a module by name. 350 */ 351 module_t * 352 module_lookup(const char *name) 353 { 354 module_t *mod; 355 356 KASSERT(mutex_owned(&module_lock)); 357 358 TAILQ_FOREACH(mod, &module_list, mod_chain) { 359 if (strcmp(mod->mod_info->mi_name, name) == 0) { 360 break; 361 } 362 } 363 364 return mod; 365 } 366 367 /* 368 * module_hold: 369 * 370 * Add a single reference to a module. It's the caller's 371 * responsibility to ensure that the reference is dropped 372 * later. 373 */ 374 int 375 module_hold(const char *name) 376 { 377 module_t *mod; 378 379 mutex_enter(&module_lock); 380 mod = module_lookup(name); 381 if (mod == NULL) { 382 mutex_exit(&module_lock); 383 return ENOENT; 384 } 385 mod->mod_refcnt++; 386 mutex_exit(&module_lock); 387 388 return 0; 389 } 390 391 /* 392 * module_rele: 393 * 394 * Release a reference acquired with module_hold(). 395 */ 396 void 397 module_rele(const char *name) 398 { 399 module_t *mod; 400 401 mutex_enter(&module_lock); 402 mod = module_lookup(name); 403 if (mod == NULL) { 404 mutex_exit(&module_lock); 405 panic("module_rele: gone"); 406 } 407 mod->mod_refcnt--; 408 mutex_exit(&module_lock); 409 } 410 411 /* 412 * module_enqueue: 413 * 414 * Put a module onto the global list and update counters. 415 */ 416 static void 417 module_enqueue(module_t *mod) 418 { 419 int i; 420 421 /* 422 * If there are requisite modules, put at the head of the queue. 423 * This is so that autounload can unload requisite modules with 424 * only one pass through the queue. 425 */ 426 if (mod->mod_nrequired) { 427 TAILQ_INSERT_HEAD(&module_list, mod, mod_chain); 428 429 /* Add references to the requisite modules. */ 430 for (i = 0; i < mod->mod_nrequired; i++) { 431 KASSERT(mod->mod_required[i] != NULL); 432 mod->mod_required[i]->mod_refcnt++; 433 } 434 } else { 435 TAILQ_INSERT_TAIL(&module_list, mod, mod_chain); 436 } 437 module_count++; 438 module_gen++; 439 } 440 441 /* 442 * module_do_builtin: 443 * 444 * Initialize a single module from the list of modules that are 445 * built into the kernel (linked into the kernel image). 446 */ 447 static int 448 module_do_builtin(const char *name, module_t **modp) 449 { 450 __link_set_decl(modules, modinfo_t); 451 modinfo_t *const *mip; 452 const char *p, *s; 453 char buf[MAXMODNAME]; 454 modinfo_t *mi; 455 module_t *mod, *mod2; 456 size_t len; 457 int error; 458 459 KASSERT(mutex_owned(&module_lock)); 460 461 /* 462 * Check to see if already loaded. 463 */ 464 if ((mod = module_lookup(name)) != NULL) { 465 if (modp != NULL) { 466 *modp = mod; 467 } 468 return 0; 469 } 470 471 /* 472 * Search the list to see if we have a module by this name. 473 */ 474 error = ENOENT; 475 __link_set_foreach(mip, modules) { 476 mi = *mip; 477 if (mi == &module_dummy) { 478 continue; 479 } 480 if (strcmp(mi->mi_name, name) == 0) { 481 error = 0; 482 break; 483 } 484 } 485 if (error != 0) { 486 module_error("can't find `%s'", name); 487 return error; 488 } 489 490 /* 491 * Initialize pre-requisites. 492 */ 493 mod = kmem_zalloc(sizeof(*mod), KM_SLEEP); 494 if (mod == NULL) { 495 module_error("out of memory for `%s'", name); 496 return ENOMEM; 497 } 498 if (modp != NULL) { 499 *modp = mod; 500 } 501 if (mi->mi_required != NULL) { 502 for (s = mi->mi_required; *s != '\0'; s = p) { 503 if (*s == ',') 504 s++; 505 p = s; 506 while (*p != '\0' && *p != ',') 507 p++; 508 len = min(p - s + 1, sizeof(buf)); 509 strlcpy(buf, s, len); 510 if (buf[0] == '\0') 511 break; 512 if (mod->mod_nrequired == MAXMODDEPS - 1) { 513 module_error("too many required modules"); 514 kmem_free(mod, sizeof(*mod)); 515 return EINVAL; 516 } 517 error = module_do_builtin(buf, &mod2); 518 if (error != 0) { 519 kmem_free(mod, sizeof(*mod)); 520 return error; 521 } 522 mod->mod_required[mod->mod_nrequired++] = mod2; 523 } 524 } 525 526 /* 527 * Try to initialize the module. 528 */ 529 KASSERT(module_active == NULL); 530 module_active = mod; 531 error = (*mi->mi_modcmd)(MODULE_CMD_INIT, NULL); 532 module_active = NULL; 533 if (error != 0) { 534 module_error("builtin module `%s' " 535 "failed to init", mi->mi_name); 536 kmem_free(mod, sizeof(*mod)); 537 return error; 538 } 539 mod->mod_info = mi; 540 mod->mod_source = MODULE_SOURCE_KERNEL; 541 module_enqueue(mod); 542 return 0; 543 } 544 545 /* 546 * module_do_load: 547 * 548 * Helper routine: load a module from the file system, or one 549 * pushed by the boot loader. 550 */ 551 static int 552 module_do_load(const char *name, bool isdep, int flags, 553 prop_dictionary_t props, module_t **modp, modclass_t class, 554 bool autoload) 555 { 556 static TAILQ_HEAD(,module) pending = TAILQ_HEAD_INITIALIZER(pending); 557 static int depth; 558 const int maxdepth = 6; 559 modinfo_t *mi; 560 module_t *mod, *mod2; 561 char buf[MAXMODNAME]; 562 const char *s, *p; 563 int error; 564 size_t len; 565 566 KASSERT(mutex_owned(&module_lock)); 567 568 error = 0; 569 570 /* 571 * Avoid recursing too far. 572 */ 573 if (++depth > maxdepth) { 574 module_error("too many required modules"); 575 depth--; 576 return EMLINK; 577 } 578 579 /* 580 * Load the module and link. Before going to the file system, 581 * scan the list of modules loaded by the boot loader. Just 582 * before init is started the list of modules loaded at boot 583 * will be purged. Before init is started we can assume that 584 * `name' is a module name and not a path name. 585 */ 586 TAILQ_FOREACH(mod, &module_bootlist, mod_chain) { 587 if (strcmp(mod->mod_info->mi_name, name) == 0) { 588 TAILQ_REMOVE(&module_bootlist, mod, mod_chain); 589 break; 590 } 591 } 592 if (mod != NULL) { 593 TAILQ_INSERT_TAIL(&pending, mod, mod_chain); 594 } else { 595 /* 596 * If a requisite module, check to see if it is 597 * already present. 598 */ 599 if (isdep) { 600 TAILQ_FOREACH(mod, &module_list, mod_chain) { 601 if (strcmp(mod->mod_info->mi_name, name) == 0) { 602 break; 603 } 604 } 605 if (mod != NULL) { 606 if (modp != NULL) { 607 *modp = mod; 608 } 609 depth--; 610 return 0; 611 } 612 } 613 mod = kmem_zalloc(sizeof(*mod), KM_SLEEP); 614 if (mod == NULL) { 615 module_error("out of memory for `%s'", name); 616 depth--; 617 return ENOMEM; 618 } 619 error = kobj_load_file(&mod->mod_kobj, name, module_base, 620 autoload); 621 if (error != 0) { 622 kmem_free(mod, sizeof(*mod)); 623 depth--; 624 if (autoload) { 625 module_print("Cannot load kernel object `%s'" 626 " error=%d", name, error); 627 } else { 628 module_error("Cannot load kernel object `%s'" 629 " error=%d", name, error); 630 } 631 return error; 632 } 633 TAILQ_INSERT_TAIL(&pending, mod, mod_chain); 634 mod->mod_source = MODULE_SOURCE_FILESYS; 635 error = module_fetch_info(mod); 636 if (error != 0) { 637 module_error("cannot fetch module info for `%s'", 638 name); 639 goto fail; 640 } 641 } 642 643 /* 644 * Check compatibility. 645 */ 646 mi = mod->mod_info; 647 if (strlen(mi->mi_name) >= MAXMODNAME) { 648 error = EINVAL; 649 module_error("module name `%s' too long", mi->mi_name); 650 goto fail; 651 } 652 if (!module_compatible(mi->mi_version, __NetBSD_Version__)) { 653 module_error("module built for `%d', system `%d'", 654 mi->mi_version, __NetBSD_Version__); 655 if ((flags & MODCTL_LOAD_FORCE) != 0) { 656 module_error("forced load, system may be unstable"); 657 } else { 658 error = EPROGMISMATCH; 659 goto fail; 660 } 661 } 662 663 /* 664 * If a specific kind of module was requested, ensure that we have 665 * a match. 666 */ 667 if (class != MODULE_CLASS_ANY && class != mi->mi_class) { 668 module_print("incompatible module class for `%s' (%d != %d)", 669 name, class, mi->mi_class); 670 error = ENOENT; 671 goto fail; 672 } 673 674 /* 675 * If loading a dependency, `name' is a plain module name. 676 * The name must match. 677 */ 678 if (isdep && strcmp(mi->mi_name, name) != 0) { 679 module_error("dependency name mismatch (`%s' != `%s')", 680 name, mi->mi_name); 681 error = ENOENT; 682 goto fail; 683 } 684 685 /* 686 * Check to see if the module is already loaded. If so, we may 687 * have been recursively called to handle a dependency, so be sure 688 * to set modp. 689 */ 690 if ((mod2 = module_lookup(mi->mi_name)) != NULL) { 691 if (modp != NULL) 692 *modp = mod2; 693 module_print("module `%s' already loaded", mi->mi_name); 694 error = EEXIST; 695 goto fail; 696 } 697 698 /* 699 * Block circular dependencies. 700 */ 701 TAILQ_FOREACH(mod2, &pending, mod_chain) { 702 if (mod == mod2) { 703 continue; 704 } 705 if (strcmp(mod2->mod_info->mi_name, mi->mi_name) == 0) { 706 error = EDEADLK; 707 module_error("circular dependency detected for `%s'", 708 mi->mi_name); 709 goto fail; 710 } 711 } 712 713 /* 714 * Now try to load any requisite modules. 715 */ 716 if (mi->mi_required != NULL) { 717 for (s = mi->mi_required; *s != '\0'; s = p) { 718 if (*s == ',') 719 s++; 720 p = s; 721 while (*p != '\0' && *p != ',') 722 p++; 723 len = p - s + 1; 724 if (len >= MAXMODNAME) { 725 error = EINVAL; 726 module_error("required module name `%s'" 727 " too long", mi->mi_required); 728 goto fail; 729 } 730 strlcpy(buf, s, len); 731 if (buf[0] == '\0') 732 break; 733 if (mod->mod_nrequired == MAXMODDEPS - 1) { 734 error = EINVAL; 735 module_error("too many required modules (%d)", 736 mod->mod_nrequired); 737 goto fail; 738 } 739 if (strcmp(buf, mi->mi_name) == 0) { 740 error = EDEADLK; 741 module_error("self-dependency detected for " 742 "`%s'", mi->mi_name); 743 goto fail; 744 } 745 error = module_do_load(buf, true, flags, NULL, 746 &mod->mod_required[mod->mod_nrequired++], 747 MODULE_CLASS_ANY, true); 748 if (error != 0) 749 goto fail; 750 } 751 } 752 753 /* 754 * We loaded all needed modules successfully: perform global 755 * relocations and initialize. 756 */ 757 error = kobj_affix(mod->mod_kobj, mi->mi_name); 758 if (error != 0) { 759 /* Cannot touch 'mi' as the module is now gone. */ 760 module_error("unable to affix module `%s'", name); 761 goto fail2; 762 } 763 764 KASSERT(module_active == NULL); 765 module_active = mod; 766 error = (*mi->mi_modcmd)(MODULE_CMD_INIT, props); 767 module_active = NULL; 768 if (error != 0) { 769 module_error("modcmd function returned error %d for `%s'", 770 error, mi->mi_name); 771 goto fail; 772 } 773 774 /* 775 * Good, the module loaded successfully. Put it onto the 776 * list and add references to its requisite modules. 777 */ 778 TAILQ_REMOVE(&pending, mod, mod_chain); 779 module_enqueue(mod); 780 if (modp != NULL) { 781 *modp = mod; 782 } 783 if (autoload) { 784 /* 785 * Arrange to try unloading the module after 786 * a short delay. 787 */ 788 mod->mod_autotime = time_second + module_autotime; 789 module_thread_kick(); 790 } 791 depth--; 792 return 0; 793 794 fail: 795 kobj_unload(mod->mod_kobj); 796 fail2: 797 TAILQ_REMOVE(&pending, mod, mod_chain); 798 kmem_free(mod, sizeof(*mod)); 799 depth--; 800 return error; 801 } 802 803 /* 804 * module_do_unload: 805 * 806 * Helper routine: do the dirty work of unloading a module. 807 */ 808 static int 809 module_do_unload(const char *name) 810 { 811 module_t *mod; 812 int error; 813 u_int i; 814 815 KASSERT(mutex_owned(&module_lock)); 816 817 mod = module_lookup(name); 818 if (mod == NULL) { 819 module_error("module `%s' not found", name); 820 return ENOENT; 821 } 822 if (mod->mod_refcnt != 0 || mod->mod_source == MODULE_SOURCE_KERNEL) { 823 module_print("module `%s' busy", name); 824 return EBUSY; 825 } 826 KASSERT(module_active == NULL); 827 module_active = mod; 828 error = (*mod->mod_info->mi_modcmd)(MODULE_CMD_FINI, NULL); 829 module_active = NULL; 830 if (error != 0) { 831 module_print("cannot unload module `%s' error=%d", name, 832 error); 833 return error; 834 } 835 module_count--; 836 TAILQ_REMOVE(&module_list, mod, mod_chain); 837 for (i = 0; i < mod->mod_nrequired; i++) { 838 mod->mod_required[i]->mod_refcnt--; 839 } 840 if (mod->mod_kobj != NULL) { 841 kobj_unload(mod->mod_kobj); 842 } 843 kmem_free(mod, sizeof(*mod)); 844 module_gen++; 845 846 return 0; 847 } 848 849 /* 850 * module_prime: 851 * 852 * Push a module loaded by the bootloader onto our internal 853 * list. 854 */ 855 int 856 module_prime(void *base, size_t size) 857 { 858 module_t *mod; 859 int error; 860 861 mod = kmem_zalloc(sizeof(*mod), KM_SLEEP); 862 if (mod == NULL) { 863 return ENOMEM; 864 } 865 mod->mod_source = MODULE_SOURCE_BOOT; 866 867 error = kobj_load_mem(&mod->mod_kobj, base, size); 868 if (error != 0) { 869 kmem_free(mod, sizeof(*mod)); 870 module_error("unable to load object pushed by boot loader"); 871 return error; 872 } 873 error = module_fetch_info(mod); 874 if (error != 0) { 875 kobj_unload(mod->mod_kobj); 876 kmem_free(mod, sizeof(*mod)); 877 module_error("unable to load object pushed by boot loader"); 878 return error; 879 } 880 881 TAILQ_INSERT_TAIL(&module_bootlist, mod, mod_chain); 882 883 return 0; 884 } 885 886 /* 887 * module_fetch_into: 888 * 889 * Fetch modinfo record from a loaded module. 890 */ 891 static int 892 module_fetch_info(module_t *mod) 893 { 894 int error; 895 void *addr; 896 size_t size; 897 898 /* 899 * Find module info record and check compatibility. 900 */ 901 error = kobj_find_section(mod->mod_kobj, "link_set_modules", 902 &addr, &size); 903 if (error != 0) { 904 module_error("`link_set_modules' section not present"); 905 return error; 906 } 907 if (size != sizeof(modinfo_t **)) { 908 module_error("`link_set_modules' section wrong size"); 909 return error; 910 } 911 mod->mod_info = *(modinfo_t **)addr; 912 913 return 0; 914 } 915 916 /* 917 * module_find_section: 918 * 919 * Allows a module that is being initialized to look up a section 920 * within its ELF object. 921 */ 922 int 923 module_find_section(const char *name, void **addr, size_t *size) 924 { 925 926 KASSERT(mutex_owned(&module_lock)); 927 KASSERT(module_active != NULL); 928 929 return kobj_find_section(module_active->mod_kobj, name, addr, size); 930 } 931 932 /* 933 * module_thread: 934 * 935 * Automatically unload modules. We try once to unload autoloaded 936 * modules after module_autotime seconds. If the system is under 937 * severe memory pressure, we'll try unloading all modules. 938 */ 939 static void 940 module_thread(void *cookie) 941 { 942 module_t *mod, *next; 943 modinfo_t *mi; 944 int error; 945 946 for (;;) { 947 mutex_enter(&module_lock); 948 for (mod = TAILQ_FIRST(&module_list); mod != NULL; mod = next) { 949 next = TAILQ_NEXT(mod, mod_chain); 950 if (uvmexp.free < uvmexp.freemin) { 951 module_thread_ticks = hz; 952 } else if (mod->mod_autotime == 0) { 953 continue; 954 } else if (time_second < mod->mod_autotime) { 955 module_thread_ticks = hz; 956 continue; 957 } else { 958 mod->mod_autotime = 0; 959 } 960 /* 961 * If this module wants to avoid autounload then 962 * skip it. Some modules can ping-pong in and out 963 * because their use is transient but often. 964 * Example: exec_script. 965 */ 966 mi = mod->mod_info; 967 error = (*mi->mi_modcmd)(MODULE_CMD_AUTOUNLOAD, NULL); 968 if (error == 0 || error == ENOTTY) { 969 (void)module_do_unload(mi->mi_name); 970 } 971 } 972 mutex_exit(&module_lock); 973 974 mutex_enter(&module_thread_lock); 975 (void)cv_timedwait(&module_thread_cv, &module_thread_lock, 976 module_thread_ticks); 977 module_thread_ticks = 0; 978 mutex_exit(&module_thread_lock); 979 } 980 } 981 982 /* 983 * module_thread: 984 * 985 * Kick the module thread into action, perhaps because the 986 * system is low on memory. 987 */ 988 void 989 module_thread_kick(void) 990 { 991 992 mutex_enter(&module_thread_lock); 993 module_thread_ticks = hz; 994 cv_broadcast(&module_thread_cv); 995 mutex_exit(&module_thread_lock); 996 } 997 998 #ifdef DDB 999 /* 1000 * module_whatis: 1001 * 1002 * Helper routine for DDB. 1003 */ 1004 void 1005 module_whatis(uintptr_t addr, void (*pr)(const char *, ...)) 1006 { 1007 module_t *mod; 1008 size_t msize; 1009 vaddr_t maddr; 1010 1011 TAILQ_FOREACH(mod, &module_list, mod_chain) { 1012 kobj_stat(mod->mod_kobj, &maddr, &msize); 1013 if (addr < maddr || addr >= maddr + msize) { 1014 continue; 1015 } 1016 (*pr)("%p is %p+%zu, in kernel module `%s'\n", 1017 (void *)addr, (void *)maddr, 1018 (size_t)(addr - maddr), mod->mod_info->mi_name); 1019 } 1020 } 1021 1022 /* 1023 * module_print_list: 1024 * 1025 * Helper routine for DDB. 1026 */ 1027 void 1028 module_print_list(void (*pr)(const char *, ...)) 1029 { 1030 const char *src; 1031 module_t *mod; 1032 size_t msize; 1033 vaddr_t maddr; 1034 1035 (*pr)("%16s %16s %8s %8s\n", "NAME", "TEXT/DATA", "SIZE", "SOURCE"); 1036 1037 TAILQ_FOREACH(mod, &module_list, mod_chain) { 1038 switch (mod->mod_source) { 1039 case MODULE_SOURCE_KERNEL: 1040 src = "builtin"; 1041 break; 1042 case MODULE_SOURCE_FILESYS: 1043 src = "filesys"; 1044 break; 1045 case MODULE_SOURCE_BOOT: 1046 src = "boot"; 1047 break; 1048 default: 1049 src = "unknown"; 1050 break; 1051 } 1052 kobj_stat(mod->mod_kobj, &maddr, &msize); 1053 (*pr)("%16s %16lx %8ld %8s\n", mod->mod_info->mi_name, 1054 (long)maddr, (long)msize, src); 1055 } 1056 } 1057 #endif /* DDB */ 1058