1 /*- 2 * Copyright (c) 1997-2000 Doug Rabson 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 */ 26 27 #include <sys/cdefs.h> 28 __FBSDID("$FreeBSD$"); 29 30 #include "opt_ddb.h" 31 #include "opt_kld.h" 32 #include "opt_hwpmc_hooks.h" 33 34 #include <sys/param.h> 35 #include <sys/kernel.h> 36 #include <sys/systm.h> 37 #include <sys/malloc.h> 38 #include <sys/sysproto.h> 39 #include <sys/sysent.h> 40 #include <sys/priv.h> 41 #include <sys/proc.h> 42 #include <sys/lock.h> 43 #include <sys/mutex.h> 44 #include <sys/sx.h> 45 #include <sys/module.h> 46 #include <sys/mount.h> 47 #include <sys/linker.h> 48 #include <sys/eventhandler.h> 49 #include <sys/fcntl.h> 50 #include <sys/jail.h> 51 #include <sys/libkern.h> 52 #include <sys/namei.h> 53 #include <sys/vnode.h> 54 #include <sys/syscallsubr.h> 55 #include <sys/sysctl.h> 56 57 #include <net/vnet.h> 58 59 #include <security/mac/mac_framework.h> 60 61 #include "linker_if.h" 62 63 #ifdef HWPMC_HOOKS 64 #include <sys/pmckern.h> 65 #endif 66 67 #ifdef KLD_DEBUG 68 int kld_debug = 0; 69 SYSCTL_INT(_debug, OID_AUTO, kld_debug, CTLFLAG_RWTUN, 70 &kld_debug, 0, "Set various levels of KLD debug"); 71 #endif 72 73 /* 74 * static char *linker_search_path(const char *name, struct mod_depend 75 * *verinfo); 76 */ 77 static const char *linker_basename(const char *path); 78 79 /* 80 * Find a currently loaded file given its filename. 81 */ 82 static linker_file_t linker_find_file_by_name(const char* _filename); 83 84 /* 85 * Find a currently loaded file given its file id. 86 */ 87 static linker_file_t linker_find_file_by_id(int _fileid); 88 89 /* Metadata from the static kernel */ 90 SET_DECLARE(modmetadata_set, struct mod_metadata); 91 92 MALLOC_DEFINE(M_LINKER, "linker", "kernel linker"); 93 94 linker_file_t linker_kernel_file; 95 96 static struct sx kld_sx; /* kernel linker lock */ 97 98 /* 99 * Load counter used by clients to determine if a linker file has been 100 * re-loaded. This counter is incremented for each file load. 101 */ 102 static int loadcnt; 103 104 static linker_class_list_t classes; 105 static linker_file_list_t linker_files; 106 static int next_file_id = 1; 107 static int linker_no_more_classes = 0; 108 109 #define LINKER_GET_NEXT_FILE_ID(a) do { \ 110 linker_file_t lftmp; \ 111 \ 112 if (!cold) \ 113 sx_assert(&kld_sx, SA_XLOCKED); \ 114 retry: \ 115 TAILQ_FOREACH(lftmp, &linker_files, link) { \ 116 if (next_file_id == lftmp->id) { \ 117 next_file_id++; \ 118 goto retry; \ 119 } \ 120 } \ 121 (a) = next_file_id; \ 122 } while(0) 123 124 125 /* XXX wrong name; we're looking at version provision tags here, not modules */ 126 typedef TAILQ_HEAD(, modlist) modlisthead_t; 127 struct modlist { 128 TAILQ_ENTRY(modlist) link; /* chain together all modules */ 129 linker_file_t container; 130 const char *name; 131 int version; 132 }; 133 typedef struct modlist *modlist_t; 134 static modlisthead_t found_modules; 135 136 static int linker_file_add_dependency(linker_file_t file, 137 linker_file_t dep); 138 static caddr_t linker_file_lookup_symbol_internal(linker_file_t file, 139 const char* name, int deps); 140 static int linker_load_module(const char *kldname, 141 const char *modname, struct linker_file *parent, 142 struct mod_depend *verinfo, struct linker_file **lfpp); 143 static modlist_t modlist_lookup2(const char *name, struct mod_depend *verinfo); 144 145 static void 146 linker_init(void *arg) 147 { 148 149 sx_init(&kld_sx, "kernel linker"); 150 TAILQ_INIT(&classes); 151 TAILQ_INIT(&linker_files); 152 } 153 154 SYSINIT(linker, SI_SUB_KLD, SI_ORDER_FIRST, linker_init, 0); 155 156 static void 157 linker_stop_class_add(void *arg) 158 { 159 160 linker_no_more_classes = 1; 161 } 162 163 SYSINIT(linker_class, SI_SUB_KLD, SI_ORDER_ANY, linker_stop_class_add, NULL); 164 165 int 166 linker_add_class(linker_class_t lc) 167 { 168 169 /* 170 * We disallow any class registration past SI_ORDER_ANY 171 * of SI_SUB_KLD. We bump the reference count to keep the 172 * ops from being freed. 173 */ 174 if (linker_no_more_classes == 1) 175 return (EPERM); 176 kobj_class_compile((kobj_class_t) lc); 177 ((kobj_class_t)lc)->refs++; /* XXX: kobj_mtx */ 178 TAILQ_INSERT_TAIL(&classes, lc, link); 179 return (0); 180 } 181 182 static void 183 linker_file_sysinit(linker_file_t lf) 184 { 185 struct sysinit **start, **stop, **sipp, **xipp, *save; 186 187 KLD_DPF(FILE, ("linker_file_sysinit: calling SYSINITs for %s\n", 188 lf->filename)); 189 190 sx_assert(&kld_sx, SA_XLOCKED); 191 192 if (linker_file_lookup_set(lf, "sysinit_set", &start, &stop, NULL) != 0) 193 return; 194 /* 195 * Perform a bubble sort of the system initialization objects by 196 * their subsystem (primary key) and order (secondary key). 197 * 198 * Since some things care about execution order, this is the operation 199 * which ensures continued function. 200 */ 201 for (sipp = start; sipp < stop; sipp++) { 202 for (xipp = sipp + 1; xipp < stop; xipp++) { 203 if ((*sipp)->subsystem < (*xipp)->subsystem || 204 ((*sipp)->subsystem == (*xipp)->subsystem && 205 (*sipp)->order <= (*xipp)->order)) 206 continue; /* skip */ 207 save = *sipp; 208 *sipp = *xipp; 209 *xipp = save; 210 } 211 } 212 213 /* 214 * Traverse the (now) ordered list of system initialization tasks. 215 * Perform each task, and continue on to the next task. 216 */ 217 sx_xunlock(&kld_sx); 218 mtx_lock(&Giant); 219 for (sipp = start; sipp < stop; sipp++) { 220 if ((*sipp)->subsystem == SI_SUB_DUMMY) 221 continue; /* skip dummy task(s) */ 222 223 /* Call function */ 224 (*((*sipp)->func)) ((*sipp)->udata); 225 } 226 mtx_unlock(&Giant); 227 sx_xlock(&kld_sx); 228 } 229 230 static void 231 linker_file_sysuninit(linker_file_t lf) 232 { 233 struct sysinit **start, **stop, **sipp, **xipp, *save; 234 235 KLD_DPF(FILE, ("linker_file_sysuninit: calling SYSUNINITs for %s\n", 236 lf->filename)); 237 238 sx_assert(&kld_sx, SA_XLOCKED); 239 240 if (linker_file_lookup_set(lf, "sysuninit_set", &start, &stop, 241 NULL) != 0) 242 return; 243 244 /* 245 * Perform a reverse bubble sort of the system initialization objects 246 * by their subsystem (primary key) and order (secondary key). 247 * 248 * Since some things care about execution order, this is the operation 249 * which ensures continued function. 250 */ 251 for (sipp = start; sipp < stop; sipp++) { 252 for (xipp = sipp + 1; xipp < stop; xipp++) { 253 if ((*sipp)->subsystem > (*xipp)->subsystem || 254 ((*sipp)->subsystem == (*xipp)->subsystem && 255 (*sipp)->order >= (*xipp)->order)) 256 continue; /* skip */ 257 save = *sipp; 258 *sipp = *xipp; 259 *xipp = save; 260 } 261 } 262 263 /* 264 * Traverse the (now) ordered list of system initialization tasks. 265 * Perform each task, and continue on to the next task. 266 */ 267 sx_xunlock(&kld_sx); 268 mtx_lock(&Giant); 269 for (sipp = start; sipp < stop; sipp++) { 270 if ((*sipp)->subsystem == SI_SUB_DUMMY) 271 continue; /* skip dummy task(s) */ 272 273 /* Call function */ 274 (*((*sipp)->func)) ((*sipp)->udata); 275 } 276 mtx_unlock(&Giant); 277 sx_xlock(&kld_sx); 278 } 279 280 static void 281 linker_file_register_sysctls(linker_file_t lf) 282 { 283 struct sysctl_oid **start, **stop, **oidp; 284 285 KLD_DPF(FILE, 286 ("linker_file_register_sysctls: registering SYSCTLs for %s\n", 287 lf->filename)); 288 289 sx_assert(&kld_sx, SA_XLOCKED); 290 291 if (linker_file_lookup_set(lf, "sysctl_set", &start, &stop, NULL) != 0) 292 return; 293 294 sx_xunlock(&kld_sx); 295 sysctl_lock(); 296 for (oidp = start; oidp < stop; oidp++) 297 sysctl_register_oid(*oidp); 298 sysctl_unlock(); 299 sx_xlock(&kld_sx); 300 } 301 302 static void 303 linker_file_unregister_sysctls(linker_file_t lf) 304 { 305 struct sysctl_oid **start, **stop, **oidp; 306 307 KLD_DPF(FILE, ("linker_file_unregister_sysctls: unregistering SYSCTLs" 308 " for %s\n", lf->filename)); 309 310 sx_assert(&kld_sx, SA_XLOCKED); 311 312 if (linker_file_lookup_set(lf, "sysctl_set", &start, &stop, NULL) != 0) 313 return; 314 315 sx_xunlock(&kld_sx); 316 sysctl_lock(); 317 for (oidp = start; oidp < stop; oidp++) 318 sysctl_unregister_oid(*oidp); 319 sysctl_unlock(); 320 sx_xlock(&kld_sx); 321 } 322 323 static int 324 linker_file_register_modules(linker_file_t lf) 325 { 326 struct mod_metadata **start, **stop, **mdp; 327 const moduledata_t *moddata; 328 int first_error, error; 329 330 KLD_DPF(FILE, ("linker_file_register_modules: registering modules" 331 " in %s\n", lf->filename)); 332 333 sx_assert(&kld_sx, SA_XLOCKED); 334 335 if (linker_file_lookup_set(lf, "modmetadata_set", &start, 336 &stop, NULL) != 0) { 337 /* 338 * This fallback should be unnecessary, but if we get booted 339 * from boot2 instead of loader and we are missing our 340 * metadata then we have to try the best we can. 341 */ 342 if (lf == linker_kernel_file) { 343 start = SET_BEGIN(modmetadata_set); 344 stop = SET_LIMIT(modmetadata_set); 345 } else 346 return (0); 347 } 348 first_error = 0; 349 for (mdp = start; mdp < stop; mdp++) { 350 if ((*mdp)->md_type != MDT_MODULE) 351 continue; 352 moddata = (*mdp)->md_data; 353 KLD_DPF(FILE, ("Registering module %s in %s\n", 354 moddata->name, lf->filename)); 355 error = module_register(moddata, lf); 356 if (error) { 357 printf("Module %s failed to register: %d\n", 358 moddata->name, error); 359 if (first_error == 0) 360 first_error = error; 361 } 362 } 363 return (first_error); 364 } 365 366 static void 367 linker_init_kernel_modules(void) 368 { 369 370 sx_xlock(&kld_sx); 371 linker_file_register_modules(linker_kernel_file); 372 sx_xunlock(&kld_sx); 373 } 374 375 SYSINIT(linker_kernel, SI_SUB_KLD, SI_ORDER_ANY, linker_init_kernel_modules, 376 0); 377 378 static int 379 linker_load_file(const char *filename, linker_file_t *result) 380 { 381 linker_class_t lc; 382 linker_file_t lf; 383 int foundfile, error, modules; 384 385 /* Refuse to load modules if securelevel raised */ 386 if (prison0.pr_securelevel > 0) 387 return (EPERM); 388 389 sx_assert(&kld_sx, SA_XLOCKED); 390 lf = linker_find_file_by_name(filename); 391 if (lf) { 392 KLD_DPF(FILE, ("linker_load_file: file %s is already loaded," 393 " incrementing refs\n", filename)); 394 *result = lf; 395 lf->refs++; 396 return (0); 397 } 398 foundfile = 0; 399 error = 0; 400 401 /* 402 * We do not need to protect (lock) classes here because there is 403 * no class registration past startup (SI_SUB_KLD, SI_ORDER_ANY) 404 * and there is no class deregistration mechanism at this time. 405 */ 406 TAILQ_FOREACH(lc, &classes, link) { 407 KLD_DPF(FILE, ("linker_load_file: trying to load %s\n", 408 filename)); 409 error = LINKER_LOAD_FILE(lc, filename, &lf); 410 /* 411 * If we got something other than ENOENT, then it exists but 412 * we cannot load it for some other reason. 413 */ 414 if (error != ENOENT) 415 foundfile = 1; 416 if (lf) { 417 error = linker_file_register_modules(lf); 418 if (error == EEXIST) { 419 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 420 return (error); 421 } 422 modules = !TAILQ_EMPTY(&lf->modules); 423 linker_file_register_sysctls(lf); 424 linker_file_sysinit(lf); 425 lf->flags |= LINKER_FILE_LINKED; 426 427 /* 428 * If all of the modules in this file failed 429 * to load, unload the file and return an 430 * error of ENOEXEC. 431 */ 432 if (modules && TAILQ_EMPTY(&lf->modules)) { 433 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 434 return (ENOEXEC); 435 } 436 EVENTHANDLER_INVOKE(kld_load, lf); 437 *result = lf; 438 return (0); 439 } 440 } 441 /* 442 * Less than ideal, but tells the user whether it failed to load or 443 * the module was not found. 444 */ 445 if (foundfile) { 446 447 /* 448 * If the file type has not been recognized by the last try 449 * printout a message before to fail. 450 */ 451 if (error == ENOSYS) 452 printf("linker_load_file: Unsupported file type\n"); 453 454 /* 455 * Format not recognized or otherwise unloadable. 456 * When loading a module that is statically built into 457 * the kernel EEXIST percolates back up as the return 458 * value. Preserve this so that apps like sysinstall 459 * can recognize this special case and not post bogus 460 * dialog boxes. 461 */ 462 if (error != EEXIST) 463 error = ENOEXEC; 464 } else 465 error = ENOENT; /* Nothing found */ 466 return (error); 467 } 468 469 int 470 linker_reference_module(const char *modname, struct mod_depend *verinfo, 471 linker_file_t *result) 472 { 473 modlist_t mod; 474 int error; 475 476 sx_xlock(&kld_sx); 477 if ((mod = modlist_lookup2(modname, verinfo)) != NULL) { 478 *result = mod->container; 479 (*result)->refs++; 480 sx_xunlock(&kld_sx); 481 return (0); 482 } 483 484 error = linker_load_module(NULL, modname, NULL, verinfo, result); 485 sx_xunlock(&kld_sx); 486 return (error); 487 } 488 489 int 490 linker_release_module(const char *modname, struct mod_depend *verinfo, 491 linker_file_t lf) 492 { 493 modlist_t mod; 494 int error; 495 496 sx_xlock(&kld_sx); 497 if (lf == NULL) { 498 KASSERT(modname != NULL, 499 ("linker_release_module: no file or name")); 500 mod = modlist_lookup2(modname, verinfo); 501 if (mod == NULL) { 502 sx_xunlock(&kld_sx); 503 return (ESRCH); 504 } 505 lf = mod->container; 506 } else 507 KASSERT(modname == NULL && verinfo == NULL, 508 ("linker_release_module: both file and name")); 509 error = linker_file_unload(lf, LINKER_UNLOAD_NORMAL); 510 sx_xunlock(&kld_sx); 511 return (error); 512 } 513 514 static linker_file_t 515 linker_find_file_by_name(const char *filename) 516 { 517 linker_file_t lf; 518 char *koname; 519 520 koname = malloc(strlen(filename) + 4, M_LINKER, M_WAITOK); 521 sprintf(koname, "%s.ko", filename); 522 523 sx_assert(&kld_sx, SA_XLOCKED); 524 TAILQ_FOREACH(lf, &linker_files, link) { 525 if (strcmp(lf->filename, koname) == 0) 526 break; 527 if (strcmp(lf->filename, filename) == 0) 528 break; 529 } 530 free(koname, M_LINKER); 531 return (lf); 532 } 533 534 static linker_file_t 535 linker_find_file_by_id(int fileid) 536 { 537 linker_file_t lf; 538 539 sx_assert(&kld_sx, SA_XLOCKED); 540 TAILQ_FOREACH(lf, &linker_files, link) 541 if (lf->id == fileid && lf->flags & LINKER_FILE_LINKED) 542 break; 543 return (lf); 544 } 545 546 int 547 linker_file_foreach(linker_predicate_t *predicate, void *context) 548 { 549 linker_file_t lf; 550 int retval = 0; 551 552 sx_xlock(&kld_sx); 553 TAILQ_FOREACH(lf, &linker_files, link) { 554 retval = predicate(lf, context); 555 if (retval != 0) 556 break; 557 } 558 sx_xunlock(&kld_sx); 559 return (retval); 560 } 561 562 linker_file_t 563 linker_make_file(const char *pathname, linker_class_t lc) 564 { 565 linker_file_t lf; 566 const char *filename; 567 568 if (!cold) 569 sx_assert(&kld_sx, SA_XLOCKED); 570 filename = linker_basename(pathname); 571 572 KLD_DPF(FILE, ("linker_make_file: new file, filename='%s' for pathname='%s'\n", filename, pathname)); 573 lf = (linker_file_t)kobj_create((kobj_class_t)lc, M_LINKER, M_WAITOK); 574 if (lf == NULL) 575 return (NULL); 576 lf->refs = 1; 577 lf->userrefs = 0; 578 lf->flags = 0; 579 lf->filename = strdup(filename, M_LINKER); 580 lf->pathname = strdup(pathname, M_LINKER); 581 LINKER_GET_NEXT_FILE_ID(lf->id); 582 lf->ndeps = 0; 583 lf->deps = NULL; 584 lf->loadcnt = ++loadcnt; 585 STAILQ_INIT(&lf->common); 586 TAILQ_INIT(&lf->modules); 587 TAILQ_INSERT_TAIL(&linker_files, lf, link); 588 return (lf); 589 } 590 591 int 592 linker_file_unload(linker_file_t file, int flags) 593 { 594 module_t mod, next; 595 modlist_t ml, nextml; 596 struct common_symbol *cp; 597 int error, i; 598 599 /* Refuse to unload modules if securelevel raised. */ 600 if (prison0.pr_securelevel > 0) 601 return (EPERM); 602 603 sx_assert(&kld_sx, SA_XLOCKED); 604 KLD_DPF(FILE, ("linker_file_unload: lf->refs=%d\n", file->refs)); 605 606 /* Easy case of just dropping a reference. */ 607 if (file->refs > 1) { 608 file->refs--; 609 return (0); 610 } 611 612 /* Give eventhandlers a chance to prevent the unload. */ 613 error = 0; 614 EVENTHANDLER_INVOKE(kld_unload_try, file, &error); 615 if (error != 0) 616 return (EBUSY); 617 618 KLD_DPF(FILE, ("linker_file_unload: file is unloading," 619 " informing modules\n")); 620 621 /* 622 * Quiesce all the modules to give them a chance to veto the unload. 623 */ 624 MOD_SLOCK; 625 for (mod = TAILQ_FIRST(&file->modules); mod; 626 mod = module_getfnext(mod)) { 627 628 error = module_quiesce(mod); 629 if (error != 0 && flags != LINKER_UNLOAD_FORCE) { 630 KLD_DPF(FILE, ("linker_file_unload: module %s" 631 " vetoed unload\n", module_getname(mod))); 632 /* 633 * XXX: Do we need to tell all the quiesced modules 634 * that they can resume work now via a new module 635 * event? 636 */ 637 MOD_SUNLOCK; 638 return (error); 639 } 640 } 641 MOD_SUNLOCK; 642 643 /* 644 * Inform any modules associated with this file that they are 645 * being unloaded. 646 */ 647 MOD_XLOCK; 648 for (mod = TAILQ_FIRST(&file->modules); mod; mod = next) { 649 next = module_getfnext(mod); 650 MOD_XUNLOCK; 651 652 /* 653 * Give the module a chance to veto the unload. 654 */ 655 if ((error = module_unload(mod)) != 0) { 656 #ifdef KLD_DEBUG 657 MOD_SLOCK; 658 KLD_DPF(FILE, ("linker_file_unload: module %s" 659 " failed unload\n", module_getname(mod))); 660 MOD_SUNLOCK; 661 #endif 662 return (error); 663 } 664 MOD_XLOCK; 665 module_release(mod); 666 } 667 MOD_XUNLOCK; 668 669 TAILQ_FOREACH_SAFE(ml, &found_modules, link, nextml) { 670 if (ml->container == file) { 671 TAILQ_REMOVE(&found_modules, ml, link); 672 free(ml, M_LINKER); 673 } 674 } 675 676 /* 677 * Don't try to run SYSUNINITs if we are unloaded due to a 678 * link error. 679 */ 680 if (file->flags & LINKER_FILE_LINKED) { 681 file->flags &= ~LINKER_FILE_LINKED; 682 linker_file_sysuninit(file); 683 linker_file_unregister_sysctls(file); 684 } 685 TAILQ_REMOVE(&linker_files, file, link); 686 687 if (file->deps) { 688 for (i = 0; i < file->ndeps; i++) 689 linker_file_unload(file->deps[i], flags); 690 free(file->deps, M_LINKER); 691 file->deps = NULL; 692 } 693 while ((cp = STAILQ_FIRST(&file->common)) != NULL) { 694 STAILQ_REMOVE_HEAD(&file->common, link); 695 free(cp, M_LINKER); 696 } 697 698 LINKER_UNLOAD(file); 699 700 EVENTHANDLER_INVOKE(kld_unload, file->filename, file->address, 701 file->size); 702 703 if (file->filename) { 704 free(file->filename, M_LINKER); 705 file->filename = NULL; 706 } 707 if (file->pathname) { 708 free(file->pathname, M_LINKER); 709 file->pathname = NULL; 710 } 711 kobj_delete((kobj_t) file, M_LINKER); 712 return (0); 713 } 714 715 int 716 linker_ctf_get(linker_file_t file, linker_ctf_t *lc) 717 { 718 return (LINKER_CTF_GET(file, lc)); 719 } 720 721 static int 722 linker_file_add_dependency(linker_file_t file, linker_file_t dep) 723 { 724 linker_file_t *newdeps; 725 726 sx_assert(&kld_sx, SA_XLOCKED); 727 file->deps = realloc(file->deps, (file->ndeps + 1) * sizeof(*newdeps), 728 M_LINKER, M_WAITOK | M_ZERO); 729 file->deps[file->ndeps] = dep; 730 file->ndeps++; 731 KLD_DPF(FILE, ("linker_file_add_dependency:" 732 " adding %s as dependency for %s\n", 733 dep->filename, file->filename)); 734 return (0); 735 } 736 737 /* 738 * Locate a linker set and its contents. This is a helper function to avoid 739 * linker_if.h exposure elsewhere. Note: firstp and lastp are really void **. 740 * This function is used in this file so we can avoid having lots of (void **) 741 * casts. 742 */ 743 int 744 linker_file_lookup_set(linker_file_t file, const char *name, 745 void *firstp, void *lastp, int *countp) 746 { 747 748 sx_assert(&kld_sx, SA_LOCKED); 749 return (LINKER_LOOKUP_SET(file, name, firstp, lastp, countp)); 750 } 751 752 /* 753 * List all functions in a file. 754 */ 755 int 756 linker_file_function_listall(linker_file_t lf, 757 linker_function_nameval_callback_t callback_func, void *arg) 758 { 759 return (LINKER_EACH_FUNCTION_NAMEVAL(lf, callback_func, arg)); 760 } 761 762 caddr_t 763 linker_file_lookup_symbol(linker_file_t file, const char *name, int deps) 764 { 765 caddr_t sym; 766 int locked; 767 768 locked = sx_xlocked(&kld_sx); 769 if (!locked) 770 sx_xlock(&kld_sx); 771 sym = linker_file_lookup_symbol_internal(file, name, deps); 772 if (!locked) 773 sx_xunlock(&kld_sx); 774 return (sym); 775 } 776 777 static caddr_t 778 linker_file_lookup_symbol_internal(linker_file_t file, const char *name, 779 int deps) 780 { 781 c_linker_sym_t sym; 782 linker_symval_t symval; 783 caddr_t address; 784 size_t common_size = 0; 785 int i; 786 787 sx_assert(&kld_sx, SA_XLOCKED); 788 KLD_DPF(SYM, ("linker_file_lookup_symbol: file=%p, name=%s, deps=%d\n", 789 file, name, deps)); 790 791 if (LINKER_LOOKUP_SYMBOL(file, name, &sym) == 0) { 792 LINKER_SYMBOL_VALUES(file, sym, &symval); 793 if (symval.value == 0) 794 /* 795 * For commons, first look them up in the 796 * dependencies and only allocate space if not found 797 * there. 798 */ 799 common_size = symval.size; 800 else { 801 KLD_DPF(SYM, ("linker_file_lookup_symbol: symbol" 802 ".value=%p\n", symval.value)); 803 return (symval.value); 804 } 805 } 806 if (deps) { 807 for (i = 0; i < file->ndeps; i++) { 808 address = linker_file_lookup_symbol_internal( 809 file->deps[i], name, 0); 810 if (address) { 811 KLD_DPF(SYM, ("linker_file_lookup_symbol:" 812 " deps value=%p\n", address)); 813 return (address); 814 } 815 } 816 } 817 if (common_size > 0) { 818 /* 819 * This is a common symbol which was not found in the 820 * dependencies. We maintain a simple common symbol table in 821 * the file object. 822 */ 823 struct common_symbol *cp; 824 825 STAILQ_FOREACH(cp, &file->common, link) { 826 if (strcmp(cp->name, name) == 0) { 827 KLD_DPF(SYM, ("linker_file_lookup_symbol:" 828 " old common value=%p\n", cp->address)); 829 return (cp->address); 830 } 831 } 832 /* 833 * Round the symbol size up to align. 834 */ 835 common_size = (common_size + sizeof(int) - 1) & -sizeof(int); 836 cp = malloc(sizeof(struct common_symbol) 837 + common_size + strlen(name) + 1, M_LINKER, 838 M_WAITOK | M_ZERO); 839 cp->address = (caddr_t)(cp + 1); 840 cp->name = cp->address + common_size; 841 strcpy(cp->name, name); 842 bzero(cp->address, common_size); 843 STAILQ_INSERT_TAIL(&file->common, cp, link); 844 845 KLD_DPF(SYM, ("linker_file_lookup_symbol: new common" 846 " value=%p\n", cp->address)); 847 return (cp->address); 848 } 849 KLD_DPF(SYM, ("linker_file_lookup_symbol: fail\n")); 850 return (0); 851 } 852 853 /* 854 * Both DDB and stack(9) rely on the kernel linker to provide forward and 855 * backward lookup of symbols. However, DDB and sometimes stack(9) need to 856 * do this in a lockfree manner. We provide a set of internal helper 857 * routines to perform these operations without locks, and then wrappers that 858 * optionally lock. 859 * 860 * linker_debug_lookup() is ifdef DDB as currently it's only used by DDB. 861 */ 862 #ifdef DDB 863 static int 864 linker_debug_lookup(const char *symstr, c_linker_sym_t *sym) 865 { 866 linker_file_t lf; 867 868 TAILQ_FOREACH(lf, &linker_files, link) { 869 if (LINKER_LOOKUP_SYMBOL(lf, symstr, sym) == 0) 870 return (0); 871 } 872 return (ENOENT); 873 } 874 #endif 875 876 static int 877 linker_debug_search_symbol(caddr_t value, c_linker_sym_t *sym, long *diffp) 878 { 879 linker_file_t lf; 880 c_linker_sym_t best, es; 881 u_long diff, bestdiff, off; 882 883 best = 0; 884 off = (uintptr_t)value; 885 bestdiff = off; 886 TAILQ_FOREACH(lf, &linker_files, link) { 887 if (LINKER_SEARCH_SYMBOL(lf, value, &es, &diff) != 0) 888 continue; 889 if (es != 0 && diff < bestdiff) { 890 best = es; 891 bestdiff = diff; 892 } 893 if (bestdiff == 0) 894 break; 895 } 896 if (best) { 897 *sym = best; 898 *diffp = bestdiff; 899 return (0); 900 } else { 901 *sym = 0; 902 *diffp = off; 903 return (ENOENT); 904 } 905 } 906 907 static int 908 linker_debug_symbol_values(c_linker_sym_t sym, linker_symval_t *symval) 909 { 910 linker_file_t lf; 911 912 TAILQ_FOREACH(lf, &linker_files, link) { 913 if (LINKER_SYMBOL_VALUES(lf, sym, symval) == 0) 914 return (0); 915 } 916 return (ENOENT); 917 } 918 919 static int 920 linker_debug_search_symbol_name(caddr_t value, char *buf, u_int buflen, 921 long *offset) 922 { 923 linker_symval_t symval; 924 c_linker_sym_t sym; 925 int error; 926 927 *offset = 0; 928 error = linker_debug_search_symbol(value, &sym, offset); 929 if (error) 930 return (error); 931 error = linker_debug_symbol_values(sym, &symval); 932 if (error) 933 return (error); 934 strlcpy(buf, symval.name, buflen); 935 return (0); 936 } 937 938 /* 939 * DDB Helpers. DDB has to look across multiple files with their own symbol 940 * tables and string tables. 941 * 942 * Note that we do not obey list locking protocols here. We really don't need 943 * DDB to hang because somebody's got the lock held. We'll take the chance 944 * that the files list is inconsistant instead. 945 */ 946 #ifdef DDB 947 int 948 linker_ddb_lookup(const char *symstr, c_linker_sym_t *sym) 949 { 950 951 return (linker_debug_lookup(symstr, sym)); 952 } 953 #endif 954 955 int 956 linker_ddb_search_symbol(caddr_t value, c_linker_sym_t *sym, long *diffp) 957 { 958 959 return (linker_debug_search_symbol(value, sym, diffp)); 960 } 961 962 int 963 linker_ddb_symbol_values(c_linker_sym_t sym, linker_symval_t *symval) 964 { 965 966 return (linker_debug_symbol_values(sym, symval)); 967 } 968 969 int 970 linker_ddb_search_symbol_name(caddr_t value, char *buf, u_int buflen, 971 long *offset) 972 { 973 974 return (linker_debug_search_symbol_name(value, buf, buflen, offset)); 975 } 976 977 /* 978 * stack(9) helper for non-debugging environemnts. Unlike DDB helpers, we do 979 * obey locking protocols, and offer a significantly less complex interface. 980 */ 981 int 982 linker_search_symbol_name(caddr_t value, char *buf, u_int buflen, 983 long *offset) 984 { 985 int error; 986 987 sx_xlock(&kld_sx); 988 error = linker_debug_search_symbol_name(value, buf, buflen, offset); 989 sx_xunlock(&kld_sx); 990 return (error); 991 } 992 993 /* 994 * Syscalls. 995 */ 996 int 997 kern_kldload(struct thread *td, const char *file, int *fileid) 998 { 999 const char *kldname, *modname; 1000 linker_file_t lf; 1001 int error; 1002 1003 if ((error = securelevel_gt(td->td_ucred, 0)) != 0) 1004 return (error); 1005 1006 if ((error = priv_check(td, PRIV_KLD_LOAD)) != 0) 1007 return (error); 1008 1009 /* 1010 * It is possible that kldloaded module will attach a new ifnet, 1011 * so vnet context must be set when this ocurs. 1012 */ 1013 CURVNET_SET(TD_TO_VNET(td)); 1014 1015 /* 1016 * If file does not contain a qualified name or any dot in it 1017 * (kldname.ko, or kldname.ver.ko) treat it as an interface 1018 * name. 1019 */ 1020 if (strchr(file, '/') || strchr(file, '.')) { 1021 kldname = file; 1022 modname = NULL; 1023 } else { 1024 kldname = NULL; 1025 modname = file; 1026 } 1027 1028 sx_xlock(&kld_sx); 1029 error = linker_load_module(kldname, modname, NULL, NULL, &lf); 1030 if (error) { 1031 sx_xunlock(&kld_sx); 1032 goto done; 1033 } 1034 lf->userrefs++; 1035 if (fileid != NULL) 1036 *fileid = lf->id; 1037 sx_xunlock(&kld_sx); 1038 1039 done: 1040 CURVNET_RESTORE(); 1041 return (error); 1042 } 1043 1044 int 1045 sys_kldload(struct thread *td, struct kldload_args *uap) 1046 { 1047 char *pathname = NULL; 1048 int error, fileid; 1049 1050 td->td_retval[0] = -1; 1051 1052 pathname = malloc(MAXPATHLEN, M_TEMP, M_WAITOK); 1053 error = copyinstr(uap->file, pathname, MAXPATHLEN, NULL); 1054 if (error == 0) { 1055 error = kern_kldload(td, pathname, &fileid); 1056 if (error == 0) 1057 td->td_retval[0] = fileid; 1058 } 1059 free(pathname, M_TEMP); 1060 return (error); 1061 } 1062 1063 int 1064 kern_kldunload(struct thread *td, int fileid, int flags) 1065 { 1066 linker_file_t lf; 1067 int error = 0; 1068 1069 if ((error = securelevel_gt(td->td_ucred, 0)) != 0) 1070 return (error); 1071 1072 if ((error = priv_check(td, PRIV_KLD_UNLOAD)) != 0) 1073 return (error); 1074 1075 CURVNET_SET(TD_TO_VNET(td)); 1076 sx_xlock(&kld_sx); 1077 lf = linker_find_file_by_id(fileid); 1078 if (lf) { 1079 KLD_DPF(FILE, ("kldunload: lf->userrefs=%d\n", lf->userrefs)); 1080 1081 if (lf->userrefs == 0) { 1082 /* 1083 * XXX: maybe LINKER_UNLOAD_FORCE should override ? 1084 */ 1085 printf("kldunload: attempt to unload file that was" 1086 " loaded by the kernel\n"); 1087 error = EBUSY; 1088 } else { 1089 lf->userrefs--; 1090 error = linker_file_unload(lf, flags); 1091 if (error) 1092 lf->userrefs++; 1093 } 1094 } else 1095 error = ENOENT; 1096 sx_xunlock(&kld_sx); 1097 1098 CURVNET_RESTORE(); 1099 return (error); 1100 } 1101 1102 int 1103 sys_kldunload(struct thread *td, struct kldunload_args *uap) 1104 { 1105 1106 return (kern_kldunload(td, uap->fileid, LINKER_UNLOAD_NORMAL)); 1107 } 1108 1109 int 1110 sys_kldunloadf(struct thread *td, struct kldunloadf_args *uap) 1111 { 1112 1113 if (uap->flags != LINKER_UNLOAD_NORMAL && 1114 uap->flags != LINKER_UNLOAD_FORCE) 1115 return (EINVAL); 1116 return (kern_kldunload(td, uap->fileid, uap->flags)); 1117 } 1118 1119 int 1120 sys_kldfind(struct thread *td, struct kldfind_args *uap) 1121 { 1122 char *pathname; 1123 const char *filename; 1124 linker_file_t lf; 1125 int error; 1126 1127 #ifdef MAC 1128 error = mac_kld_check_stat(td->td_ucred); 1129 if (error) 1130 return (error); 1131 #endif 1132 1133 td->td_retval[0] = -1; 1134 1135 pathname = malloc(MAXPATHLEN, M_TEMP, M_WAITOK); 1136 if ((error = copyinstr(uap->file, pathname, MAXPATHLEN, NULL)) != 0) 1137 goto out; 1138 1139 filename = linker_basename(pathname); 1140 sx_xlock(&kld_sx); 1141 lf = linker_find_file_by_name(filename); 1142 if (lf) 1143 td->td_retval[0] = lf->id; 1144 else 1145 error = ENOENT; 1146 sx_xunlock(&kld_sx); 1147 out: 1148 free(pathname, M_TEMP); 1149 return (error); 1150 } 1151 1152 int 1153 sys_kldnext(struct thread *td, struct kldnext_args *uap) 1154 { 1155 linker_file_t lf; 1156 int error = 0; 1157 1158 #ifdef MAC 1159 error = mac_kld_check_stat(td->td_ucred); 1160 if (error) 1161 return (error); 1162 #endif 1163 1164 sx_xlock(&kld_sx); 1165 if (uap->fileid == 0) 1166 lf = TAILQ_FIRST(&linker_files); 1167 else { 1168 lf = linker_find_file_by_id(uap->fileid); 1169 if (lf == NULL) { 1170 error = ENOENT; 1171 goto out; 1172 } 1173 lf = TAILQ_NEXT(lf, link); 1174 } 1175 1176 /* Skip partially loaded files. */ 1177 while (lf != NULL && !(lf->flags & LINKER_FILE_LINKED)) 1178 lf = TAILQ_NEXT(lf, link); 1179 1180 if (lf) 1181 td->td_retval[0] = lf->id; 1182 else 1183 td->td_retval[0] = 0; 1184 out: 1185 sx_xunlock(&kld_sx); 1186 return (error); 1187 } 1188 1189 int 1190 sys_kldstat(struct thread *td, struct kldstat_args *uap) 1191 { 1192 struct kld_file_stat stat; 1193 int error, version; 1194 1195 /* 1196 * Check the version of the user's structure. 1197 */ 1198 if ((error = copyin(&uap->stat->version, &version, sizeof(version))) 1199 != 0) 1200 return (error); 1201 if (version != sizeof(struct kld_file_stat_1) && 1202 version != sizeof(struct kld_file_stat)) 1203 return (EINVAL); 1204 1205 error = kern_kldstat(td, uap->fileid, &stat); 1206 if (error != 0) 1207 return (error); 1208 return (copyout(&stat, uap->stat, version)); 1209 } 1210 1211 int 1212 kern_kldstat(struct thread *td, int fileid, struct kld_file_stat *stat) 1213 { 1214 linker_file_t lf; 1215 int namelen; 1216 #ifdef MAC 1217 int error; 1218 1219 error = mac_kld_check_stat(td->td_ucred); 1220 if (error) 1221 return (error); 1222 #endif 1223 1224 sx_xlock(&kld_sx); 1225 lf = linker_find_file_by_id(fileid); 1226 if (lf == NULL) { 1227 sx_xunlock(&kld_sx); 1228 return (ENOENT); 1229 } 1230 1231 /* Version 1 fields: */ 1232 namelen = strlen(lf->filename) + 1; 1233 if (namelen > MAXPATHLEN) 1234 namelen = MAXPATHLEN; 1235 bcopy(lf->filename, &stat->name[0], namelen); 1236 stat->refs = lf->refs; 1237 stat->id = lf->id; 1238 stat->address = lf->address; 1239 stat->size = lf->size; 1240 /* Version 2 fields: */ 1241 namelen = strlen(lf->pathname) + 1; 1242 if (namelen > MAXPATHLEN) 1243 namelen = MAXPATHLEN; 1244 bcopy(lf->pathname, &stat->pathname[0], namelen); 1245 sx_xunlock(&kld_sx); 1246 1247 td->td_retval[0] = 0; 1248 return (0); 1249 } 1250 1251 int 1252 sys_kldfirstmod(struct thread *td, struct kldfirstmod_args *uap) 1253 { 1254 linker_file_t lf; 1255 module_t mp; 1256 int error = 0; 1257 1258 #ifdef MAC 1259 error = mac_kld_check_stat(td->td_ucred); 1260 if (error) 1261 return (error); 1262 #endif 1263 1264 sx_xlock(&kld_sx); 1265 lf = linker_find_file_by_id(uap->fileid); 1266 if (lf) { 1267 MOD_SLOCK; 1268 mp = TAILQ_FIRST(&lf->modules); 1269 if (mp != NULL) 1270 td->td_retval[0] = module_getid(mp); 1271 else 1272 td->td_retval[0] = 0; 1273 MOD_SUNLOCK; 1274 } else 1275 error = ENOENT; 1276 sx_xunlock(&kld_sx); 1277 return (error); 1278 } 1279 1280 int 1281 sys_kldsym(struct thread *td, struct kldsym_args *uap) 1282 { 1283 char *symstr = NULL; 1284 c_linker_sym_t sym; 1285 linker_symval_t symval; 1286 linker_file_t lf; 1287 struct kld_sym_lookup lookup; 1288 int error = 0; 1289 1290 #ifdef MAC 1291 error = mac_kld_check_stat(td->td_ucred); 1292 if (error) 1293 return (error); 1294 #endif 1295 1296 if ((error = copyin(uap->data, &lookup, sizeof(lookup))) != 0) 1297 return (error); 1298 if (lookup.version != sizeof(lookup) || 1299 uap->cmd != KLDSYM_LOOKUP) 1300 return (EINVAL); 1301 symstr = malloc(MAXPATHLEN, M_TEMP, M_WAITOK); 1302 if ((error = copyinstr(lookup.symname, symstr, MAXPATHLEN, NULL)) != 0) 1303 goto out; 1304 sx_xlock(&kld_sx); 1305 if (uap->fileid != 0) { 1306 lf = linker_find_file_by_id(uap->fileid); 1307 if (lf == NULL) 1308 error = ENOENT; 1309 else if (LINKER_LOOKUP_SYMBOL(lf, symstr, &sym) == 0 && 1310 LINKER_SYMBOL_VALUES(lf, sym, &symval) == 0) { 1311 lookup.symvalue = (uintptr_t) symval.value; 1312 lookup.symsize = symval.size; 1313 error = copyout(&lookup, uap->data, sizeof(lookup)); 1314 } else 1315 error = ENOENT; 1316 } else { 1317 TAILQ_FOREACH(lf, &linker_files, link) { 1318 if (LINKER_LOOKUP_SYMBOL(lf, symstr, &sym) == 0 && 1319 LINKER_SYMBOL_VALUES(lf, sym, &symval) == 0) { 1320 lookup.symvalue = (uintptr_t)symval.value; 1321 lookup.symsize = symval.size; 1322 error = copyout(&lookup, uap->data, 1323 sizeof(lookup)); 1324 break; 1325 } 1326 } 1327 if (lf == NULL) 1328 error = ENOENT; 1329 } 1330 sx_xunlock(&kld_sx); 1331 out: 1332 free(symstr, M_TEMP); 1333 return (error); 1334 } 1335 1336 /* 1337 * Preloaded module support 1338 */ 1339 1340 static modlist_t 1341 modlist_lookup(const char *name, int ver) 1342 { 1343 modlist_t mod; 1344 1345 TAILQ_FOREACH(mod, &found_modules, link) { 1346 if (strcmp(mod->name, name) == 0 && 1347 (ver == 0 || mod->version == ver)) 1348 return (mod); 1349 } 1350 return (NULL); 1351 } 1352 1353 static modlist_t 1354 modlist_lookup2(const char *name, struct mod_depend *verinfo) 1355 { 1356 modlist_t mod, bestmod; 1357 int ver; 1358 1359 if (verinfo == NULL) 1360 return (modlist_lookup(name, 0)); 1361 bestmod = NULL; 1362 TAILQ_FOREACH(mod, &found_modules, link) { 1363 if (strcmp(mod->name, name) != 0) 1364 continue; 1365 ver = mod->version; 1366 if (ver == verinfo->md_ver_preferred) 1367 return (mod); 1368 if (ver >= verinfo->md_ver_minimum && 1369 ver <= verinfo->md_ver_maximum && 1370 (bestmod == NULL || ver > bestmod->version)) 1371 bestmod = mod; 1372 } 1373 return (bestmod); 1374 } 1375 1376 static modlist_t 1377 modlist_newmodule(const char *modname, int version, linker_file_t container) 1378 { 1379 modlist_t mod; 1380 1381 mod = malloc(sizeof(struct modlist), M_LINKER, M_NOWAIT | M_ZERO); 1382 if (mod == NULL) 1383 panic("no memory for module list"); 1384 mod->container = container; 1385 mod->name = modname; 1386 mod->version = version; 1387 TAILQ_INSERT_TAIL(&found_modules, mod, link); 1388 return (mod); 1389 } 1390 1391 static void 1392 linker_addmodules(linker_file_t lf, struct mod_metadata **start, 1393 struct mod_metadata **stop, int preload) 1394 { 1395 struct mod_metadata *mp, **mdp; 1396 const char *modname; 1397 int ver; 1398 1399 for (mdp = start; mdp < stop; mdp++) { 1400 mp = *mdp; 1401 if (mp->md_type != MDT_VERSION) 1402 continue; 1403 modname = mp->md_cval; 1404 ver = ((struct mod_version *)mp->md_data)->mv_version; 1405 if (modlist_lookup(modname, ver) != NULL) { 1406 printf("module %s already present!\n", modname); 1407 /* XXX what can we do? this is a build error. :-( */ 1408 continue; 1409 } 1410 modlist_newmodule(modname, ver, lf); 1411 } 1412 } 1413 1414 static void 1415 linker_preload(void *arg) 1416 { 1417 caddr_t modptr; 1418 const char *modname, *nmodname; 1419 char *modtype; 1420 linker_file_t lf, nlf; 1421 linker_class_t lc; 1422 int error; 1423 linker_file_list_t loaded_files; 1424 linker_file_list_t depended_files; 1425 struct mod_metadata *mp, *nmp; 1426 struct mod_metadata **start, **stop, **mdp, **nmdp; 1427 struct mod_depend *verinfo; 1428 int nver; 1429 int resolves; 1430 modlist_t mod; 1431 struct sysinit **si_start, **si_stop; 1432 1433 TAILQ_INIT(&loaded_files); 1434 TAILQ_INIT(&depended_files); 1435 TAILQ_INIT(&found_modules); 1436 error = 0; 1437 1438 modptr = NULL; 1439 sx_xlock(&kld_sx); 1440 while ((modptr = preload_search_next_name(modptr)) != NULL) { 1441 modname = (char *)preload_search_info(modptr, MODINFO_NAME); 1442 modtype = (char *)preload_search_info(modptr, MODINFO_TYPE); 1443 if (modname == NULL) { 1444 printf("Preloaded module at %p does not have a" 1445 " name!\n", modptr); 1446 continue; 1447 } 1448 if (modtype == NULL) { 1449 printf("Preloaded module at %p does not have a type!\n", 1450 modptr); 1451 continue; 1452 } 1453 if (bootverbose) 1454 printf("Preloaded %s \"%s\" at %p.\n", modtype, modname, 1455 modptr); 1456 lf = NULL; 1457 TAILQ_FOREACH(lc, &classes, link) { 1458 error = LINKER_LINK_PRELOAD(lc, modname, &lf); 1459 if (!error) 1460 break; 1461 lf = NULL; 1462 } 1463 if (lf) 1464 TAILQ_INSERT_TAIL(&loaded_files, lf, loaded); 1465 } 1466 1467 /* 1468 * First get a list of stuff in the kernel. 1469 */ 1470 if (linker_file_lookup_set(linker_kernel_file, MDT_SETNAME, &start, 1471 &stop, NULL) == 0) 1472 linker_addmodules(linker_kernel_file, start, stop, 1); 1473 1474 /* 1475 * This is a once-off kinky bubble sort to resolve relocation 1476 * dependency requirements. 1477 */ 1478 restart: 1479 TAILQ_FOREACH(lf, &loaded_files, loaded) { 1480 error = linker_file_lookup_set(lf, MDT_SETNAME, &start, 1481 &stop, NULL); 1482 /* 1483 * First, look to see if we would successfully link with this 1484 * stuff. 1485 */ 1486 resolves = 1; /* unless we know otherwise */ 1487 if (!error) { 1488 for (mdp = start; mdp < stop; mdp++) { 1489 mp = *mdp; 1490 if (mp->md_type != MDT_DEPEND) 1491 continue; 1492 modname = mp->md_cval; 1493 verinfo = mp->md_data; 1494 for (nmdp = start; nmdp < stop; nmdp++) { 1495 nmp = *nmdp; 1496 if (nmp->md_type != MDT_VERSION) 1497 continue; 1498 nmodname = nmp->md_cval; 1499 if (strcmp(modname, nmodname) == 0) 1500 break; 1501 } 1502 if (nmdp < stop) /* it's a self reference */ 1503 continue; 1504 1505 /* 1506 * ok, the module isn't here yet, we 1507 * are not finished 1508 */ 1509 if (modlist_lookup2(modname, verinfo) == NULL) 1510 resolves = 0; 1511 } 1512 } 1513 /* 1514 * OK, if we found our modules, we can link. So, "provide" 1515 * the modules inside and add it to the end of the link order 1516 * list. 1517 */ 1518 if (resolves) { 1519 if (!error) { 1520 for (mdp = start; mdp < stop; mdp++) { 1521 mp = *mdp; 1522 if (mp->md_type != MDT_VERSION) 1523 continue; 1524 modname = mp->md_cval; 1525 nver = ((struct mod_version *) 1526 mp->md_data)->mv_version; 1527 if (modlist_lookup(modname, 1528 nver) != NULL) { 1529 printf("module %s already" 1530 " present!\n", modname); 1531 TAILQ_REMOVE(&loaded_files, 1532 lf, loaded); 1533 linker_file_unload(lf, 1534 LINKER_UNLOAD_FORCE); 1535 /* we changed tailq next ptr */ 1536 goto restart; 1537 } 1538 modlist_newmodule(modname, nver, lf); 1539 } 1540 } 1541 TAILQ_REMOVE(&loaded_files, lf, loaded); 1542 TAILQ_INSERT_TAIL(&depended_files, lf, loaded); 1543 /* 1544 * Since we provided modules, we need to restart the 1545 * sort so that the previous files that depend on us 1546 * have a chance. Also, we've busted the tailq next 1547 * pointer with the REMOVE. 1548 */ 1549 goto restart; 1550 } 1551 } 1552 1553 /* 1554 * At this point, we check to see what could not be resolved.. 1555 */ 1556 while ((lf = TAILQ_FIRST(&loaded_files)) != NULL) { 1557 TAILQ_REMOVE(&loaded_files, lf, loaded); 1558 printf("KLD file %s is missing dependencies\n", lf->filename); 1559 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 1560 } 1561 1562 /* 1563 * We made it. Finish off the linking in the order we determined. 1564 */ 1565 TAILQ_FOREACH_SAFE(lf, &depended_files, loaded, nlf) { 1566 if (linker_kernel_file) { 1567 linker_kernel_file->refs++; 1568 error = linker_file_add_dependency(lf, 1569 linker_kernel_file); 1570 if (error) 1571 panic("cannot add dependency"); 1572 } 1573 lf->userrefs++; /* so we can (try to) kldunload it */ 1574 error = linker_file_lookup_set(lf, MDT_SETNAME, &start, 1575 &stop, NULL); 1576 if (!error) { 1577 for (mdp = start; mdp < stop; mdp++) { 1578 mp = *mdp; 1579 if (mp->md_type != MDT_DEPEND) 1580 continue; 1581 modname = mp->md_cval; 1582 verinfo = mp->md_data; 1583 mod = modlist_lookup2(modname, verinfo); 1584 if (mod == NULL) { 1585 printf("KLD file %s - cannot find " 1586 "dependency \"%s\"\n", 1587 lf->filename, modname); 1588 goto fail; 1589 } 1590 /* Don't count self-dependencies */ 1591 if (lf == mod->container) 1592 continue; 1593 mod->container->refs++; 1594 error = linker_file_add_dependency(lf, 1595 mod->container); 1596 if (error) 1597 panic("cannot add dependency"); 1598 } 1599 } 1600 /* 1601 * Now do relocation etc using the symbol search paths 1602 * established by the dependencies 1603 */ 1604 error = LINKER_LINK_PRELOAD_FINISH(lf); 1605 if (error) { 1606 printf("KLD file %s - could not finalize loading\n", 1607 lf->filename); 1608 goto fail; 1609 } 1610 linker_file_register_modules(lf); 1611 if (linker_file_lookup_set(lf, "sysinit_set", &si_start, 1612 &si_stop, NULL) == 0) 1613 sysinit_add(si_start, si_stop); 1614 linker_file_register_sysctls(lf); 1615 lf->flags |= LINKER_FILE_LINKED; 1616 continue; 1617 fail: 1618 TAILQ_REMOVE(&depended_files, lf, loaded); 1619 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 1620 } 1621 sx_xunlock(&kld_sx); 1622 /* woohoo! we made it! */ 1623 } 1624 1625 SYSINIT(preload, SI_SUB_KLD, SI_ORDER_MIDDLE, linker_preload, 0); 1626 1627 /* 1628 * Search for a not-loaded module by name. 1629 * 1630 * Modules may be found in the following locations: 1631 * 1632 * - preloaded (result is just the module name) - on disk (result is full path 1633 * to module) 1634 * 1635 * If the module name is qualified in any way (contains path, etc.) the we 1636 * simply return a copy of it. 1637 * 1638 * The search path can be manipulated via sysctl. Note that we use the ';' 1639 * character as a separator to be consistent with the bootloader. 1640 */ 1641 1642 static char linker_hintfile[] = "linker.hints"; 1643 static char linker_path[MAXPATHLEN] = "/boot/kernel;/boot/modules"; 1644 1645 SYSCTL_STRING(_kern, OID_AUTO, module_path, CTLFLAG_RWTUN, linker_path, 1646 sizeof(linker_path), "module load search path"); 1647 1648 TUNABLE_STR("module_path", linker_path, sizeof(linker_path)); 1649 1650 static char *linker_ext_list[] = { 1651 "", 1652 ".ko", 1653 NULL 1654 }; 1655 1656 /* 1657 * Check if file actually exists either with or without extension listed in 1658 * the linker_ext_list. (probably should be generic for the rest of the 1659 * kernel) 1660 */ 1661 static char * 1662 linker_lookup_file(const char *path, int pathlen, const char *name, 1663 int namelen, struct vattr *vap) 1664 { 1665 struct nameidata nd; 1666 struct thread *td = curthread; /* XXX */ 1667 char *result, **cpp, *sep; 1668 int error, len, extlen, reclen, flags; 1669 enum vtype type; 1670 1671 extlen = 0; 1672 for (cpp = linker_ext_list; *cpp; cpp++) { 1673 len = strlen(*cpp); 1674 if (len > extlen) 1675 extlen = len; 1676 } 1677 extlen++; /* trailing '\0' */ 1678 sep = (path[pathlen - 1] != '/') ? "/" : ""; 1679 1680 reclen = pathlen + strlen(sep) + namelen + extlen + 1; 1681 result = malloc(reclen, M_LINKER, M_WAITOK); 1682 for (cpp = linker_ext_list; *cpp; cpp++) { 1683 snprintf(result, reclen, "%.*s%s%.*s%s", pathlen, path, sep, 1684 namelen, name, *cpp); 1685 /* 1686 * Attempt to open the file, and return the path if 1687 * we succeed and it's a regular file. 1688 */ 1689 NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, result, td); 1690 flags = FREAD; 1691 error = vn_open(&nd, &flags, 0, NULL); 1692 if (error == 0) { 1693 NDFREE(&nd, NDF_ONLY_PNBUF); 1694 type = nd.ni_vp->v_type; 1695 if (vap) 1696 VOP_GETATTR(nd.ni_vp, vap, td->td_ucred); 1697 VOP_UNLOCK(nd.ni_vp, 0); 1698 vn_close(nd.ni_vp, FREAD, td->td_ucred, td); 1699 if (type == VREG) 1700 return (result); 1701 } 1702 } 1703 free(result, M_LINKER); 1704 return (NULL); 1705 } 1706 1707 #define INT_ALIGN(base, ptr) ptr = \ 1708 (base) + (((ptr) - (base) + sizeof(int) - 1) & ~(sizeof(int) - 1)) 1709 1710 /* 1711 * Lookup KLD which contains requested module in the "linker.hints" file. If 1712 * version specification is available, then try to find the best KLD. 1713 * Otherwise just find the latest one. 1714 */ 1715 static char * 1716 linker_hints_lookup(const char *path, int pathlen, const char *modname, 1717 int modnamelen, struct mod_depend *verinfo) 1718 { 1719 struct thread *td = curthread; /* XXX */ 1720 struct ucred *cred = td ? td->td_ucred : NULL; 1721 struct nameidata nd; 1722 struct vattr vattr, mattr; 1723 u_char *hints = NULL; 1724 u_char *cp, *recptr, *bufend, *result, *best, *pathbuf, *sep; 1725 int error, ival, bestver, *intp, found, flags, clen, blen; 1726 ssize_t reclen; 1727 1728 result = NULL; 1729 bestver = found = 0; 1730 1731 sep = (path[pathlen - 1] != '/') ? "/" : ""; 1732 reclen = imax(modnamelen, strlen(linker_hintfile)) + pathlen + 1733 strlen(sep) + 1; 1734 pathbuf = malloc(reclen, M_LINKER, M_WAITOK); 1735 snprintf(pathbuf, reclen, "%.*s%s%s", pathlen, path, sep, 1736 linker_hintfile); 1737 1738 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, pathbuf, td); 1739 flags = FREAD; 1740 error = vn_open(&nd, &flags, 0, NULL); 1741 if (error) 1742 goto bad; 1743 NDFREE(&nd, NDF_ONLY_PNBUF); 1744 if (nd.ni_vp->v_type != VREG) 1745 goto bad; 1746 best = cp = NULL; 1747 error = VOP_GETATTR(nd.ni_vp, &vattr, cred); 1748 if (error) 1749 goto bad; 1750 /* 1751 * XXX: we need to limit this number to some reasonable value 1752 */ 1753 if (vattr.va_size > 100 * 1024) { 1754 printf("hints file too large %ld\n", (long)vattr.va_size); 1755 goto bad; 1756 } 1757 hints = malloc(vattr.va_size, M_TEMP, M_WAITOK); 1758 if (hints == NULL) 1759 goto bad; 1760 error = vn_rdwr(UIO_READ, nd.ni_vp, (caddr_t)hints, vattr.va_size, 0, 1761 UIO_SYSSPACE, IO_NODELOCKED, cred, NOCRED, &reclen, td); 1762 if (error) 1763 goto bad; 1764 VOP_UNLOCK(nd.ni_vp, 0); 1765 vn_close(nd.ni_vp, FREAD, cred, td); 1766 nd.ni_vp = NULL; 1767 if (reclen != 0) { 1768 printf("can't read %zd\n", reclen); 1769 goto bad; 1770 } 1771 intp = (int *)hints; 1772 ival = *intp++; 1773 if (ival != LINKER_HINTS_VERSION) { 1774 printf("hints file version mismatch %d\n", ival); 1775 goto bad; 1776 } 1777 bufend = hints + vattr.va_size; 1778 recptr = (u_char *)intp; 1779 clen = blen = 0; 1780 while (recptr < bufend && !found) { 1781 intp = (int *)recptr; 1782 reclen = *intp++; 1783 ival = *intp++; 1784 cp = (char *)intp; 1785 switch (ival) { 1786 case MDT_VERSION: 1787 clen = *cp++; 1788 if (clen != modnamelen || bcmp(cp, modname, clen) != 0) 1789 break; 1790 cp += clen; 1791 INT_ALIGN(hints, cp); 1792 ival = *(int *)cp; 1793 cp += sizeof(int); 1794 clen = *cp++; 1795 if (verinfo == NULL || 1796 ival == verinfo->md_ver_preferred) { 1797 found = 1; 1798 break; 1799 } 1800 if (ival >= verinfo->md_ver_minimum && 1801 ival <= verinfo->md_ver_maximum && 1802 ival > bestver) { 1803 bestver = ival; 1804 best = cp; 1805 blen = clen; 1806 } 1807 break; 1808 default: 1809 break; 1810 } 1811 recptr += reclen + sizeof(int); 1812 } 1813 /* 1814 * Finally check if KLD is in the place 1815 */ 1816 if (found) 1817 result = linker_lookup_file(path, pathlen, cp, clen, &mattr); 1818 else if (best) 1819 result = linker_lookup_file(path, pathlen, best, blen, &mattr); 1820 1821 /* 1822 * KLD is newer than hints file. What we should do now? 1823 */ 1824 if (result && timespeccmp(&mattr.va_mtime, &vattr.va_mtime, >)) 1825 printf("warning: KLD '%s' is newer than the linker.hints" 1826 " file\n", result); 1827 bad: 1828 free(pathbuf, M_LINKER); 1829 if (hints) 1830 free(hints, M_TEMP); 1831 if (nd.ni_vp != NULL) { 1832 VOP_UNLOCK(nd.ni_vp, 0); 1833 vn_close(nd.ni_vp, FREAD, cred, td); 1834 } 1835 /* 1836 * If nothing found or hints is absent - fallback to the old 1837 * way by using "kldname[.ko]" as module name. 1838 */ 1839 if (!found && !bestver && result == NULL) 1840 result = linker_lookup_file(path, pathlen, modname, 1841 modnamelen, NULL); 1842 return (result); 1843 } 1844 1845 /* 1846 * Lookup KLD which contains requested module in the all directories. 1847 */ 1848 static char * 1849 linker_search_module(const char *modname, int modnamelen, 1850 struct mod_depend *verinfo) 1851 { 1852 char *cp, *ep, *result; 1853 1854 /* 1855 * traverse the linker path 1856 */ 1857 for (cp = linker_path; *cp; cp = ep + 1) { 1858 /* find the end of this component */ 1859 for (ep = cp; (*ep != 0) && (*ep != ';'); ep++); 1860 result = linker_hints_lookup(cp, ep - cp, modname, 1861 modnamelen, verinfo); 1862 if (result != NULL) 1863 return (result); 1864 if (*ep == 0) 1865 break; 1866 } 1867 return (NULL); 1868 } 1869 1870 /* 1871 * Search for module in all directories listed in the linker_path. 1872 */ 1873 static char * 1874 linker_search_kld(const char *name) 1875 { 1876 char *cp, *ep, *result; 1877 int len; 1878 1879 /* qualified at all? */ 1880 if (strchr(name, '/')) 1881 return (strdup(name, M_LINKER)); 1882 1883 /* traverse the linker path */ 1884 len = strlen(name); 1885 for (ep = linker_path; *ep; ep++) { 1886 cp = ep; 1887 /* find the end of this component */ 1888 for (; *ep != 0 && *ep != ';'; ep++); 1889 result = linker_lookup_file(cp, ep - cp, name, len, NULL); 1890 if (result != NULL) 1891 return (result); 1892 } 1893 return (NULL); 1894 } 1895 1896 static const char * 1897 linker_basename(const char *path) 1898 { 1899 const char *filename; 1900 1901 filename = strrchr(path, '/'); 1902 if (filename == NULL) 1903 return path; 1904 if (filename[1]) 1905 filename++; 1906 return (filename); 1907 } 1908 1909 #ifdef HWPMC_HOOKS 1910 /* 1911 * Inform hwpmc about the set of kernel modules currently loaded. 1912 */ 1913 void * 1914 linker_hwpmc_list_objects(void) 1915 { 1916 linker_file_t lf; 1917 struct pmckern_map_in *kobase; 1918 int i, nmappings; 1919 1920 nmappings = 0; 1921 sx_slock(&kld_sx); 1922 TAILQ_FOREACH(lf, &linker_files, link) 1923 nmappings++; 1924 1925 /* Allocate nmappings + 1 entries. */ 1926 kobase = malloc((nmappings + 1) * sizeof(struct pmckern_map_in), 1927 M_LINKER, M_WAITOK | M_ZERO); 1928 i = 0; 1929 TAILQ_FOREACH(lf, &linker_files, link) { 1930 1931 /* Save the info for this linker file. */ 1932 kobase[i].pm_file = lf->filename; 1933 kobase[i].pm_address = (uintptr_t)lf->address; 1934 i++; 1935 } 1936 sx_sunlock(&kld_sx); 1937 1938 KASSERT(i > 0, ("linker_hpwmc_list_objects: no kernel objects?")); 1939 1940 /* The last entry of the malloced area comprises of all zeros. */ 1941 KASSERT(kobase[i].pm_file == NULL, 1942 ("linker_hwpmc_list_objects: last object not NULL")); 1943 1944 return ((void *)kobase); 1945 } 1946 #endif 1947 1948 /* 1949 * Find a file which contains given module and load it, if "parent" is not 1950 * NULL, register a reference to it. 1951 */ 1952 static int 1953 linker_load_module(const char *kldname, const char *modname, 1954 struct linker_file *parent, struct mod_depend *verinfo, 1955 struct linker_file **lfpp) 1956 { 1957 linker_file_t lfdep; 1958 const char *filename; 1959 char *pathname; 1960 int error; 1961 1962 sx_assert(&kld_sx, SA_XLOCKED); 1963 if (modname == NULL) { 1964 /* 1965 * We have to load KLD 1966 */ 1967 KASSERT(verinfo == NULL, ("linker_load_module: verinfo" 1968 " is not NULL")); 1969 pathname = linker_search_kld(kldname); 1970 } else { 1971 if (modlist_lookup2(modname, verinfo) != NULL) 1972 return (EEXIST); 1973 if (kldname != NULL) 1974 pathname = strdup(kldname, M_LINKER); 1975 else if (rootvnode == NULL) 1976 pathname = NULL; 1977 else 1978 /* 1979 * Need to find a KLD with required module 1980 */ 1981 pathname = linker_search_module(modname, 1982 strlen(modname), verinfo); 1983 } 1984 if (pathname == NULL) 1985 return (ENOENT); 1986 1987 /* 1988 * Can't load more than one file with the same basename XXX: 1989 * Actually it should be possible to have multiple KLDs with 1990 * the same basename but different path because they can 1991 * provide different versions of the same modules. 1992 */ 1993 filename = linker_basename(pathname); 1994 if (linker_find_file_by_name(filename)) 1995 error = EEXIST; 1996 else do { 1997 error = linker_load_file(pathname, &lfdep); 1998 if (error) 1999 break; 2000 if (modname && verinfo && 2001 modlist_lookup2(modname, verinfo) == NULL) { 2002 linker_file_unload(lfdep, LINKER_UNLOAD_FORCE); 2003 error = ENOENT; 2004 break; 2005 } 2006 if (parent) { 2007 error = linker_file_add_dependency(parent, lfdep); 2008 if (error) 2009 break; 2010 } 2011 if (lfpp) 2012 *lfpp = lfdep; 2013 } while (0); 2014 free(pathname, M_LINKER); 2015 return (error); 2016 } 2017 2018 /* 2019 * This routine is responsible for finding dependencies of userland initiated 2020 * kldload(2)'s of files. 2021 */ 2022 int 2023 linker_load_dependencies(linker_file_t lf) 2024 { 2025 linker_file_t lfdep; 2026 struct mod_metadata **start, **stop, **mdp, **nmdp; 2027 struct mod_metadata *mp, *nmp; 2028 struct mod_depend *verinfo; 2029 modlist_t mod; 2030 const char *modname, *nmodname; 2031 int ver, error = 0, count; 2032 2033 /* 2034 * All files are dependant on /kernel. 2035 */ 2036 sx_assert(&kld_sx, SA_XLOCKED); 2037 if (linker_kernel_file) { 2038 linker_kernel_file->refs++; 2039 error = linker_file_add_dependency(lf, linker_kernel_file); 2040 if (error) 2041 return (error); 2042 } 2043 if (linker_file_lookup_set(lf, MDT_SETNAME, &start, &stop, 2044 &count) != 0) 2045 return (0); 2046 for (mdp = start; mdp < stop; mdp++) { 2047 mp = *mdp; 2048 if (mp->md_type != MDT_VERSION) 2049 continue; 2050 modname = mp->md_cval; 2051 ver = ((struct mod_version *)mp->md_data)->mv_version; 2052 mod = modlist_lookup(modname, ver); 2053 if (mod != NULL) { 2054 printf("interface %s.%d already present in the KLD" 2055 " '%s'!\n", modname, ver, 2056 mod->container->filename); 2057 return (EEXIST); 2058 } 2059 } 2060 2061 for (mdp = start; mdp < stop; mdp++) { 2062 mp = *mdp; 2063 if (mp->md_type != MDT_DEPEND) 2064 continue; 2065 modname = mp->md_cval; 2066 verinfo = mp->md_data; 2067 nmodname = NULL; 2068 for (nmdp = start; nmdp < stop; nmdp++) { 2069 nmp = *nmdp; 2070 if (nmp->md_type != MDT_VERSION) 2071 continue; 2072 nmodname = nmp->md_cval; 2073 if (strcmp(modname, nmodname) == 0) 2074 break; 2075 } 2076 if (nmdp < stop)/* early exit, it's a self reference */ 2077 continue; 2078 mod = modlist_lookup2(modname, verinfo); 2079 if (mod) { /* woohoo, it's loaded already */ 2080 lfdep = mod->container; 2081 lfdep->refs++; 2082 error = linker_file_add_dependency(lf, lfdep); 2083 if (error) 2084 break; 2085 continue; 2086 } 2087 error = linker_load_module(NULL, modname, lf, verinfo, NULL); 2088 if (error) { 2089 printf("KLD %s: depends on %s - not available or" 2090 " version mismatch\n", lf->filename, modname); 2091 break; 2092 } 2093 } 2094 2095 if (error) 2096 return (error); 2097 linker_addmodules(lf, start, stop, 0); 2098 return (error); 2099 } 2100 2101 static int 2102 sysctl_kern_function_list_iterate(const char *name, void *opaque) 2103 { 2104 struct sysctl_req *req; 2105 2106 req = opaque; 2107 return (SYSCTL_OUT(req, name, strlen(name) + 1)); 2108 } 2109 2110 /* 2111 * Export a nul-separated, double-nul-terminated list of all function names 2112 * in the kernel. 2113 */ 2114 static int 2115 sysctl_kern_function_list(SYSCTL_HANDLER_ARGS) 2116 { 2117 linker_file_t lf; 2118 int error; 2119 2120 #ifdef MAC 2121 error = mac_kld_check_stat(req->td->td_ucred); 2122 if (error) 2123 return (error); 2124 #endif 2125 error = sysctl_wire_old_buffer(req, 0); 2126 if (error != 0) 2127 return (error); 2128 sx_xlock(&kld_sx); 2129 TAILQ_FOREACH(lf, &linker_files, link) { 2130 error = LINKER_EACH_FUNCTION_NAME(lf, 2131 sysctl_kern_function_list_iterate, req); 2132 if (error) { 2133 sx_xunlock(&kld_sx); 2134 return (error); 2135 } 2136 } 2137 sx_xunlock(&kld_sx); 2138 return (SYSCTL_OUT(req, "", 1)); 2139 } 2140 2141 SYSCTL_PROC(_kern, OID_AUTO, function_list, CTLTYPE_OPAQUE | CTLFLAG_RD, 2142 NULL, 0, sysctl_kern_function_list, "", "kernel function list"); 2143