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_xlock(); 296 for (oidp = start; oidp < stop; oidp++) 297 sysctl_register_oid(*oidp); 298 sysctl_xunlock(); 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_xlock(); 317 for (oidp = start; oidp < stop; oidp++) 318 sysctl_unregister_oid(*oidp); 319 sysctl_xunlock(); 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->ctors_addr = 0; 577 lf->ctors_size = 0; 578 lf->refs = 1; 579 lf->userrefs = 0; 580 lf->flags = 0; 581 lf->filename = strdup(filename, M_LINKER); 582 lf->pathname = strdup(pathname, M_LINKER); 583 LINKER_GET_NEXT_FILE_ID(lf->id); 584 lf->ndeps = 0; 585 lf->deps = NULL; 586 lf->loadcnt = ++loadcnt; 587 STAILQ_INIT(&lf->common); 588 TAILQ_INIT(&lf->modules); 589 TAILQ_INSERT_TAIL(&linker_files, lf, link); 590 return (lf); 591 } 592 593 int 594 linker_file_unload(linker_file_t file, int flags) 595 { 596 module_t mod, next; 597 modlist_t ml, nextml; 598 struct common_symbol *cp; 599 int error, i; 600 601 /* Refuse to unload modules if securelevel raised. */ 602 if (prison0.pr_securelevel > 0) 603 return (EPERM); 604 605 sx_assert(&kld_sx, SA_XLOCKED); 606 KLD_DPF(FILE, ("linker_file_unload: lf->refs=%d\n", file->refs)); 607 608 /* Easy case of just dropping a reference. */ 609 if (file->refs > 1) { 610 file->refs--; 611 return (0); 612 } 613 614 /* Give eventhandlers a chance to prevent the unload. */ 615 error = 0; 616 EVENTHANDLER_INVOKE(kld_unload_try, file, &error); 617 if (error != 0) 618 return (EBUSY); 619 620 KLD_DPF(FILE, ("linker_file_unload: file is unloading," 621 " informing modules\n")); 622 623 /* 624 * Quiesce all the modules to give them a chance to veto the unload. 625 */ 626 MOD_SLOCK; 627 for (mod = TAILQ_FIRST(&file->modules); mod; 628 mod = module_getfnext(mod)) { 629 630 error = module_quiesce(mod); 631 if (error != 0 && flags != LINKER_UNLOAD_FORCE) { 632 KLD_DPF(FILE, ("linker_file_unload: module %s" 633 " vetoed unload\n", module_getname(mod))); 634 /* 635 * XXX: Do we need to tell all the quiesced modules 636 * that they can resume work now via a new module 637 * event? 638 */ 639 MOD_SUNLOCK; 640 return (error); 641 } 642 } 643 MOD_SUNLOCK; 644 645 /* 646 * Inform any modules associated with this file that they are 647 * being unloaded. 648 */ 649 MOD_XLOCK; 650 for (mod = TAILQ_FIRST(&file->modules); mod; mod = next) { 651 next = module_getfnext(mod); 652 MOD_XUNLOCK; 653 654 /* 655 * Give the module a chance to veto the unload. 656 */ 657 if ((error = module_unload(mod)) != 0) { 658 #ifdef KLD_DEBUG 659 MOD_SLOCK; 660 KLD_DPF(FILE, ("linker_file_unload: module %s" 661 " failed unload\n", module_getname(mod))); 662 MOD_SUNLOCK; 663 #endif 664 return (error); 665 } 666 MOD_XLOCK; 667 module_release(mod); 668 } 669 MOD_XUNLOCK; 670 671 TAILQ_FOREACH_SAFE(ml, &found_modules, link, nextml) { 672 if (ml->container == file) { 673 TAILQ_REMOVE(&found_modules, ml, link); 674 free(ml, M_LINKER); 675 } 676 } 677 678 /* 679 * Don't try to run SYSUNINITs if we are unloaded due to a 680 * link error. 681 */ 682 if (file->flags & LINKER_FILE_LINKED) { 683 file->flags &= ~LINKER_FILE_LINKED; 684 linker_file_sysuninit(file); 685 linker_file_unregister_sysctls(file); 686 } 687 TAILQ_REMOVE(&linker_files, file, link); 688 689 if (file->deps) { 690 for (i = 0; i < file->ndeps; i++) 691 linker_file_unload(file->deps[i], flags); 692 free(file->deps, M_LINKER); 693 file->deps = NULL; 694 } 695 while ((cp = STAILQ_FIRST(&file->common)) != NULL) { 696 STAILQ_REMOVE_HEAD(&file->common, link); 697 free(cp, M_LINKER); 698 } 699 700 LINKER_UNLOAD(file); 701 702 EVENTHANDLER_INVOKE(kld_unload, file->filename, file->address, 703 file->size); 704 705 if (file->filename) { 706 free(file->filename, M_LINKER); 707 file->filename = NULL; 708 } 709 if (file->pathname) { 710 free(file->pathname, M_LINKER); 711 file->pathname = NULL; 712 } 713 kobj_delete((kobj_t) file, M_LINKER); 714 return (0); 715 } 716 717 int 718 linker_ctf_get(linker_file_t file, linker_ctf_t *lc) 719 { 720 return (LINKER_CTF_GET(file, lc)); 721 } 722 723 static int 724 linker_file_add_dependency(linker_file_t file, linker_file_t dep) 725 { 726 linker_file_t *newdeps; 727 728 sx_assert(&kld_sx, SA_XLOCKED); 729 file->deps = realloc(file->deps, (file->ndeps + 1) * sizeof(*newdeps), 730 M_LINKER, M_WAITOK | M_ZERO); 731 file->deps[file->ndeps] = dep; 732 file->ndeps++; 733 KLD_DPF(FILE, ("linker_file_add_dependency:" 734 " adding %s as dependency for %s\n", 735 dep->filename, file->filename)); 736 return (0); 737 } 738 739 /* 740 * Locate a linker set and its contents. This is a helper function to avoid 741 * linker_if.h exposure elsewhere. Note: firstp and lastp are really void **. 742 * This function is used in this file so we can avoid having lots of (void **) 743 * casts. 744 */ 745 int 746 linker_file_lookup_set(linker_file_t file, const char *name, 747 void *firstp, void *lastp, int *countp) 748 { 749 750 sx_assert(&kld_sx, SA_LOCKED); 751 return (LINKER_LOOKUP_SET(file, name, firstp, lastp, countp)); 752 } 753 754 /* 755 * List all functions in a file. 756 */ 757 int 758 linker_file_function_listall(linker_file_t lf, 759 linker_function_nameval_callback_t callback_func, void *arg) 760 { 761 return (LINKER_EACH_FUNCTION_NAMEVAL(lf, callback_func, arg)); 762 } 763 764 caddr_t 765 linker_file_lookup_symbol(linker_file_t file, const char *name, int deps) 766 { 767 caddr_t sym; 768 int locked; 769 770 locked = sx_xlocked(&kld_sx); 771 if (!locked) 772 sx_xlock(&kld_sx); 773 sym = linker_file_lookup_symbol_internal(file, name, deps); 774 if (!locked) 775 sx_xunlock(&kld_sx); 776 return (sym); 777 } 778 779 static caddr_t 780 linker_file_lookup_symbol_internal(linker_file_t file, const char *name, 781 int deps) 782 { 783 c_linker_sym_t sym; 784 linker_symval_t symval; 785 caddr_t address; 786 size_t common_size = 0; 787 int i; 788 789 sx_assert(&kld_sx, SA_XLOCKED); 790 KLD_DPF(SYM, ("linker_file_lookup_symbol: file=%p, name=%s, deps=%d\n", 791 file, name, deps)); 792 793 if (LINKER_LOOKUP_SYMBOL(file, name, &sym) == 0) { 794 LINKER_SYMBOL_VALUES(file, sym, &symval); 795 if (symval.value == 0) 796 /* 797 * For commons, first look them up in the 798 * dependencies and only allocate space if not found 799 * there. 800 */ 801 common_size = symval.size; 802 else { 803 KLD_DPF(SYM, ("linker_file_lookup_symbol: symbol" 804 ".value=%p\n", symval.value)); 805 return (symval.value); 806 } 807 } 808 if (deps) { 809 for (i = 0; i < file->ndeps; i++) { 810 address = linker_file_lookup_symbol_internal( 811 file->deps[i], name, 0); 812 if (address) { 813 KLD_DPF(SYM, ("linker_file_lookup_symbol:" 814 " deps value=%p\n", address)); 815 return (address); 816 } 817 } 818 } 819 if (common_size > 0) { 820 /* 821 * This is a common symbol which was not found in the 822 * dependencies. We maintain a simple common symbol table in 823 * the file object. 824 */ 825 struct common_symbol *cp; 826 827 STAILQ_FOREACH(cp, &file->common, link) { 828 if (strcmp(cp->name, name) == 0) { 829 KLD_DPF(SYM, ("linker_file_lookup_symbol:" 830 " old common value=%p\n", cp->address)); 831 return (cp->address); 832 } 833 } 834 /* 835 * Round the symbol size up to align. 836 */ 837 common_size = (common_size + sizeof(int) - 1) & -sizeof(int); 838 cp = malloc(sizeof(struct common_symbol) 839 + common_size + strlen(name) + 1, M_LINKER, 840 M_WAITOK | M_ZERO); 841 cp->address = (caddr_t)(cp + 1); 842 cp->name = cp->address + common_size; 843 strcpy(cp->name, name); 844 bzero(cp->address, common_size); 845 STAILQ_INSERT_TAIL(&file->common, cp, link); 846 847 KLD_DPF(SYM, ("linker_file_lookup_symbol: new common" 848 " value=%p\n", cp->address)); 849 return (cp->address); 850 } 851 KLD_DPF(SYM, ("linker_file_lookup_symbol: fail\n")); 852 return (0); 853 } 854 855 /* 856 * Both DDB and stack(9) rely on the kernel linker to provide forward and 857 * backward lookup of symbols. However, DDB and sometimes stack(9) need to 858 * do this in a lockfree manner. We provide a set of internal helper 859 * routines to perform these operations without locks, and then wrappers that 860 * optionally lock. 861 * 862 * linker_debug_lookup() is ifdef DDB as currently it's only used by DDB. 863 */ 864 #ifdef DDB 865 static int 866 linker_debug_lookup(const char *symstr, c_linker_sym_t *sym) 867 { 868 linker_file_t lf; 869 870 TAILQ_FOREACH(lf, &linker_files, link) { 871 if (LINKER_LOOKUP_SYMBOL(lf, symstr, sym) == 0) 872 return (0); 873 } 874 return (ENOENT); 875 } 876 #endif 877 878 static int 879 linker_debug_search_symbol(caddr_t value, c_linker_sym_t *sym, long *diffp) 880 { 881 linker_file_t lf; 882 c_linker_sym_t best, es; 883 u_long diff, bestdiff, off; 884 885 best = 0; 886 off = (uintptr_t)value; 887 bestdiff = off; 888 TAILQ_FOREACH(lf, &linker_files, link) { 889 if (LINKER_SEARCH_SYMBOL(lf, value, &es, &diff) != 0) 890 continue; 891 if (es != 0 && diff < bestdiff) { 892 best = es; 893 bestdiff = diff; 894 } 895 if (bestdiff == 0) 896 break; 897 } 898 if (best) { 899 *sym = best; 900 *diffp = bestdiff; 901 return (0); 902 } else { 903 *sym = 0; 904 *diffp = off; 905 return (ENOENT); 906 } 907 } 908 909 static int 910 linker_debug_symbol_values(c_linker_sym_t sym, linker_symval_t *symval) 911 { 912 linker_file_t lf; 913 914 TAILQ_FOREACH(lf, &linker_files, link) { 915 if (LINKER_SYMBOL_VALUES(lf, sym, symval) == 0) 916 return (0); 917 } 918 return (ENOENT); 919 } 920 921 static int 922 linker_debug_search_symbol_name(caddr_t value, char *buf, u_int buflen, 923 long *offset) 924 { 925 linker_symval_t symval; 926 c_linker_sym_t sym; 927 int error; 928 929 *offset = 0; 930 error = linker_debug_search_symbol(value, &sym, offset); 931 if (error) 932 return (error); 933 error = linker_debug_symbol_values(sym, &symval); 934 if (error) 935 return (error); 936 strlcpy(buf, symval.name, buflen); 937 return (0); 938 } 939 940 /* 941 * DDB Helpers. DDB has to look across multiple files with their own symbol 942 * tables and string tables. 943 * 944 * Note that we do not obey list locking protocols here. We really don't need 945 * DDB to hang because somebody's got the lock held. We'll take the chance 946 * that the files list is inconsistant instead. 947 */ 948 #ifdef DDB 949 int 950 linker_ddb_lookup(const char *symstr, c_linker_sym_t *sym) 951 { 952 953 return (linker_debug_lookup(symstr, sym)); 954 } 955 #endif 956 957 int 958 linker_ddb_search_symbol(caddr_t value, c_linker_sym_t *sym, long *diffp) 959 { 960 961 return (linker_debug_search_symbol(value, sym, diffp)); 962 } 963 964 int 965 linker_ddb_symbol_values(c_linker_sym_t sym, linker_symval_t *symval) 966 { 967 968 return (linker_debug_symbol_values(sym, symval)); 969 } 970 971 int 972 linker_ddb_search_symbol_name(caddr_t value, char *buf, u_int buflen, 973 long *offset) 974 { 975 976 return (linker_debug_search_symbol_name(value, buf, buflen, offset)); 977 } 978 979 /* 980 * stack(9) helper for non-debugging environemnts. Unlike DDB helpers, we do 981 * obey locking protocols, and offer a significantly less complex interface. 982 */ 983 int 984 linker_search_symbol_name(caddr_t value, char *buf, u_int buflen, 985 long *offset) 986 { 987 int error; 988 989 sx_slock(&kld_sx); 990 error = linker_debug_search_symbol_name(value, buf, buflen, offset); 991 sx_sunlock(&kld_sx); 992 return (error); 993 } 994 995 /* 996 * Syscalls. 997 */ 998 int 999 kern_kldload(struct thread *td, const char *file, int *fileid) 1000 { 1001 const char *kldname, *modname; 1002 linker_file_t lf; 1003 int error; 1004 1005 if ((error = securelevel_gt(td->td_ucred, 0)) != 0) 1006 return (error); 1007 1008 if ((error = priv_check(td, PRIV_KLD_LOAD)) != 0) 1009 return (error); 1010 1011 /* 1012 * It is possible that kldloaded module will attach a new ifnet, 1013 * so vnet context must be set when this ocurs. 1014 */ 1015 CURVNET_SET(TD_TO_VNET(td)); 1016 1017 /* 1018 * If file does not contain a qualified name or any dot in it 1019 * (kldname.ko, or kldname.ver.ko) treat it as an interface 1020 * name. 1021 */ 1022 if (strchr(file, '/') || strchr(file, '.')) { 1023 kldname = file; 1024 modname = NULL; 1025 } else { 1026 kldname = NULL; 1027 modname = file; 1028 } 1029 1030 sx_xlock(&kld_sx); 1031 error = linker_load_module(kldname, modname, NULL, NULL, &lf); 1032 if (error) { 1033 sx_xunlock(&kld_sx); 1034 goto done; 1035 } 1036 lf->userrefs++; 1037 if (fileid != NULL) 1038 *fileid = lf->id; 1039 sx_xunlock(&kld_sx); 1040 1041 done: 1042 CURVNET_RESTORE(); 1043 return (error); 1044 } 1045 1046 int 1047 sys_kldload(struct thread *td, struct kldload_args *uap) 1048 { 1049 char *pathname = NULL; 1050 int error, fileid; 1051 1052 td->td_retval[0] = -1; 1053 1054 pathname = malloc(MAXPATHLEN, M_TEMP, M_WAITOK); 1055 error = copyinstr(uap->file, pathname, MAXPATHLEN, NULL); 1056 if (error == 0) { 1057 error = kern_kldload(td, pathname, &fileid); 1058 if (error == 0) 1059 td->td_retval[0] = fileid; 1060 } 1061 free(pathname, M_TEMP); 1062 return (error); 1063 } 1064 1065 int 1066 kern_kldunload(struct thread *td, int fileid, int flags) 1067 { 1068 linker_file_t lf; 1069 int error = 0; 1070 1071 if ((error = securelevel_gt(td->td_ucred, 0)) != 0) 1072 return (error); 1073 1074 if ((error = priv_check(td, PRIV_KLD_UNLOAD)) != 0) 1075 return (error); 1076 1077 CURVNET_SET(TD_TO_VNET(td)); 1078 sx_xlock(&kld_sx); 1079 lf = linker_find_file_by_id(fileid); 1080 if (lf) { 1081 KLD_DPF(FILE, ("kldunload: lf->userrefs=%d\n", lf->userrefs)); 1082 1083 if (lf->userrefs == 0) { 1084 /* 1085 * XXX: maybe LINKER_UNLOAD_FORCE should override ? 1086 */ 1087 printf("kldunload: attempt to unload file that was" 1088 " loaded by the kernel\n"); 1089 error = EBUSY; 1090 } else { 1091 lf->userrefs--; 1092 error = linker_file_unload(lf, flags); 1093 if (error) 1094 lf->userrefs++; 1095 } 1096 } else 1097 error = ENOENT; 1098 sx_xunlock(&kld_sx); 1099 1100 CURVNET_RESTORE(); 1101 return (error); 1102 } 1103 1104 int 1105 sys_kldunload(struct thread *td, struct kldunload_args *uap) 1106 { 1107 1108 return (kern_kldunload(td, uap->fileid, LINKER_UNLOAD_NORMAL)); 1109 } 1110 1111 int 1112 sys_kldunloadf(struct thread *td, struct kldunloadf_args *uap) 1113 { 1114 1115 if (uap->flags != LINKER_UNLOAD_NORMAL && 1116 uap->flags != LINKER_UNLOAD_FORCE) 1117 return (EINVAL); 1118 return (kern_kldunload(td, uap->fileid, uap->flags)); 1119 } 1120 1121 int 1122 sys_kldfind(struct thread *td, struct kldfind_args *uap) 1123 { 1124 char *pathname; 1125 const char *filename; 1126 linker_file_t lf; 1127 int error; 1128 1129 #ifdef MAC 1130 error = mac_kld_check_stat(td->td_ucred); 1131 if (error) 1132 return (error); 1133 #endif 1134 1135 td->td_retval[0] = -1; 1136 1137 pathname = malloc(MAXPATHLEN, M_TEMP, M_WAITOK); 1138 if ((error = copyinstr(uap->file, pathname, MAXPATHLEN, NULL)) != 0) 1139 goto out; 1140 1141 filename = linker_basename(pathname); 1142 sx_xlock(&kld_sx); 1143 lf = linker_find_file_by_name(filename); 1144 if (lf) 1145 td->td_retval[0] = lf->id; 1146 else 1147 error = ENOENT; 1148 sx_xunlock(&kld_sx); 1149 out: 1150 free(pathname, M_TEMP); 1151 return (error); 1152 } 1153 1154 int 1155 sys_kldnext(struct thread *td, struct kldnext_args *uap) 1156 { 1157 linker_file_t lf; 1158 int error = 0; 1159 1160 #ifdef MAC 1161 error = mac_kld_check_stat(td->td_ucred); 1162 if (error) 1163 return (error); 1164 #endif 1165 1166 sx_xlock(&kld_sx); 1167 if (uap->fileid == 0) 1168 lf = TAILQ_FIRST(&linker_files); 1169 else { 1170 lf = linker_find_file_by_id(uap->fileid); 1171 if (lf == NULL) { 1172 error = ENOENT; 1173 goto out; 1174 } 1175 lf = TAILQ_NEXT(lf, link); 1176 } 1177 1178 /* Skip partially loaded files. */ 1179 while (lf != NULL && !(lf->flags & LINKER_FILE_LINKED)) 1180 lf = TAILQ_NEXT(lf, link); 1181 1182 if (lf) 1183 td->td_retval[0] = lf->id; 1184 else 1185 td->td_retval[0] = 0; 1186 out: 1187 sx_xunlock(&kld_sx); 1188 return (error); 1189 } 1190 1191 int 1192 sys_kldstat(struct thread *td, struct kldstat_args *uap) 1193 { 1194 struct kld_file_stat stat; 1195 int error, version; 1196 1197 /* 1198 * Check the version of the user's structure. 1199 */ 1200 if ((error = copyin(&uap->stat->version, &version, sizeof(version))) 1201 != 0) 1202 return (error); 1203 if (version != sizeof(struct kld_file_stat_1) && 1204 version != sizeof(struct kld_file_stat)) 1205 return (EINVAL); 1206 1207 error = kern_kldstat(td, uap->fileid, &stat); 1208 if (error != 0) 1209 return (error); 1210 return (copyout(&stat, uap->stat, version)); 1211 } 1212 1213 int 1214 kern_kldstat(struct thread *td, int fileid, struct kld_file_stat *stat) 1215 { 1216 linker_file_t lf; 1217 int namelen; 1218 #ifdef MAC 1219 int error; 1220 1221 error = mac_kld_check_stat(td->td_ucred); 1222 if (error) 1223 return (error); 1224 #endif 1225 1226 sx_xlock(&kld_sx); 1227 lf = linker_find_file_by_id(fileid); 1228 if (lf == NULL) { 1229 sx_xunlock(&kld_sx); 1230 return (ENOENT); 1231 } 1232 1233 /* Version 1 fields: */ 1234 namelen = strlen(lf->filename) + 1; 1235 if (namelen > MAXPATHLEN) 1236 namelen = MAXPATHLEN; 1237 bcopy(lf->filename, &stat->name[0], namelen); 1238 stat->refs = lf->refs; 1239 stat->id = lf->id; 1240 stat->address = lf->address; 1241 stat->size = lf->size; 1242 /* Version 2 fields: */ 1243 namelen = strlen(lf->pathname) + 1; 1244 if (namelen > MAXPATHLEN) 1245 namelen = MAXPATHLEN; 1246 bcopy(lf->pathname, &stat->pathname[0], namelen); 1247 sx_xunlock(&kld_sx); 1248 1249 td->td_retval[0] = 0; 1250 return (0); 1251 } 1252 1253 int 1254 sys_kldfirstmod(struct thread *td, struct kldfirstmod_args *uap) 1255 { 1256 linker_file_t lf; 1257 module_t mp; 1258 int error = 0; 1259 1260 #ifdef MAC 1261 error = mac_kld_check_stat(td->td_ucred); 1262 if (error) 1263 return (error); 1264 #endif 1265 1266 sx_xlock(&kld_sx); 1267 lf = linker_find_file_by_id(uap->fileid); 1268 if (lf) { 1269 MOD_SLOCK; 1270 mp = TAILQ_FIRST(&lf->modules); 1271 if (mp != NULL) 1272 td->td_retval[0] = module_getid(mp); 1273 else 1274 td->td_retval[0] = 0; 1275 MOD_SUNLOCK; 1276 } else 1277 error = ENOENT; 1278 sx_xunlock(&kld_sx); 1279 return (error); 1280 } 1281 1282 int 1283 sys_kldsym(struct thread *td, struct kldsym_args *uap) 1284 { 1285 char *symstr = NULL; 1286 c_linker_sym_t sym; 1287 linker_symval_t symval; 1288 linker_file_t lf; 1289 struct kld_sym_lookup lookup; 1290 int error = 0; 1291 1292 #ifdef MAC 1293 error = mac_kld_check_stat(td->td_ucred); 1294 if (error) 1295 return (error); 1296 #endif 1297 1298 if ((error = copyin(uap->data, &lookup, sizeof(lookup))) != 0) 1299 return (error); 1300 if (lookup.version != sizeof(lookup) || 1301 uap->cmd != KLDSYM_LOOKUP) 1302 return (EINVAL); 1303 symstr = malloc(MAXPATHLEN, M_TEMP, M_WAITOK); 1304 if ((error = copyinstr(lookup.symname, symstr, MAXPATHLEN, NULL)) != 0) 1305 goto out; 1306 sx_xlock(&kld_sx); 1307 if (uap->fileid != 0) { 1308 lf = linker_find_file_by_id(uap->fileid); 1309 if (lf == NULL) 1310 error = ENOENT; 1311 else if (LINKER_LOOKUP_SYMBOL(lf, symstr, &sym) == 0 && 1312 LINKER_SYMBOL_VALUES(lf, sym, &symval) == 0) { 1313 lookup.symvalue = (uintptr_t) symval.value; 1314 lookup.symsize = symval.size; 1315 error = copyout(&lookup, uap->data, sizeof(lookup)); 1316 } else 1317 error = ENOENT; 1318 } else { 1319 TAILQ_FOREACH(lf, &linker_files, link) { 1320 if (LINKER_LOOKUP_SYMBOL(lf, symstr, &sym) == 0 && 1321 LINKER_SYMBOL_VALUES(lf, sym, &symval) == 0) { 1322 lookup.symvalue = (uintptr_t)symval.value; 1323 lookup.symsize = symval.size; 1324 error = copyout(&lookup, uap->data, 1325 sizeof(lookup)); 1326 break; 1327 } 1328 } 1329 if (lf == NULL) 1330 error = ENOENT; 1331 } 1332 sx_xunlock(&kld_sx); 1333 out: 1334 free(symstr, M_TEMP); 1335 return (error); 1336 } 1337 1338 /* 1339 * Preloaded module support 1340 */ 1341 1342 static modlist_t 1343 modlist_lookup(const char *name, int ver) 1344 { 1345 modlist_t mod; 1346 1347 TAILQ_FOREACH(mod, &found_modules, link) { 1348 if (strcmp(mod->name, name) == 0 && 1349 (ver == 0 || mod->version == ver)) 1350 return (mod); 1351 } 1352 return (NULL); 1353 } 1354 1355 static modlist_t 1356 modlist_lookup2(const char *name, struct mod_depend *verinfo) 1357 { 1358 modlist_t mod, bestmod; 1359 int ver; 1360 1361 if (verinfo == NULL) 1362 return (modlist_lookup(name, 0)); 1363 bestmod = NULL; 1364 TAILQ_FOREACH(mod, &found_modules, link) { 1365 if (strcmp(mod->name, name) != 0) 1366 continue; 1367 ver = mod->version; 1368 if (ver == verinfo->md_ver_preferred) 1369 return (mod); 1370 if (ver >= verinfo->md_ver_minimum && 1371 ver <= verinfo->md_ver_maximum && 1372 (bestmod == NULL || ver > bestmod->version)) 1373 bestmod = mod; 1374 } 1375 return (bestmod); 1376 } 1377 1378 static modlist_t 1379 modlist_newmodule(const char *modname, int version, linker_file_t container) 1380 { 1381 modlist_t mod; 1382 1383 mod = malloc(sizeof(struct modlist), M_LINKER, M_NOWAIT | M_ZERO); 1384 if (mod == NULL) 1385 panic("no memory for module list"); 1386 mod->container = container; 1387 mod->name = modname; 1388 mod->version = version; 1389 TAILQ_INSERT_TAIL(&found_modules, mod, link); 1390 return (mod); 1391 } 1392 1393 static void 1394 linker_addmodules(linker_file_t lf, struct mod_metadata **start, 1395 struct mod_metadata **stop, int preload) 1396 { 1397 struct mod_metadata *mp, **mdp; 1398 const char *modname; 1399 int ver; 1400 1401 for (mdp = start; mdp < stop; mdp++) { 1402 mp = *mdp; 1403 if (mp->md_type != MDT_VERSION) 1404 continue; 1405 modname = mp->md_cval; 1406 ver = ((struct mod_version *)mp->md_data)->mv_version; 1407 if (modlist_lookup(modname, ver) != NULL) { 1408 printf("module %s already present!\n", modname); 1409 /* XXX what can we do? this is a build error. :-( */ 1410 continue; 1411 } 1412 modlist_newmodule(modname, ver, lf); 1413 } 1414 } 1415 1416 static void 1417 linker_preload(void *arg) 1418 { 1419 caddr_t modptr; 1420 const char *modname, *nmodname; 1421 char *modtype; 1422 linker_file_t lf, nlf; 1423 linker_class_t lc; 1424 int error; 1425 linker_file_list_t loaded_files; 1426 linker_file_list_t depended_files; 1427 struct mod_metadata *mp, *nmp; 1428 struct mod_metadata **start, **stop, **mdp, **nmdp; 1429 struct mod_depend *verinfo; 1430 int nver; 1431 int resolves; 1432 modlist_t mod; 1433 struct sysinit **si_start, **si_stop; 1434 1435 TAILQ_INIT(&loaded_files); 1436 TAILQ_INIT(&depended_files); 1437 TAILQ_INIT(&found_modules); 1438 error = 0; 1439 1440 modptr = NULL; 1441 sx_xlock(&kld_sx); 1442 while ((modptr = preload_search_next_name(modptr)) != NULL) { 1443 modname = (char *)preload_search_info(modptr, MODINFO_NAME); 1444 modtype = (char *)preload_search_info(modptr, MODINFO_TYPE); 1445 if (modname == NULL) { 1446 printf("Preloaded module at %p does not have a" 1447 " name!\n", modptr); 1448 continue; 1449 } 1450 if (modtype == NULL) { 1451 printf("Preloaded module at %p does not have a type!\n", 1452 modptr); 1453 continue; 1454 } 1455 if (bootverbose) 1456 printf("Preloaded %s \"%s\" at %p.\n", modtype, modname, 1457 modptr); 1458 lf = NULL; 1459 TAILQ_FOREACH(lc, &classes, link) { 1460 error = LINKER_LINK_PRELOAD(lc, modname, &lf); 1461 if (!error) 1462 break; 1463 lf = NULL; 1464 } 1465 if (lf) 1466 TAILQ_INSERT_TAIL(&loaded_files, lf, loaded); 1467 } 1468 1469 /* 1470 * First get a list of stuff in the kernel. 1471 */ 1472 if (linker_file_lookup_set(linker_kernel_file, MDT_SETNAME, &start, 1473 &stop, NULL) == 0) 1474 linker_addmodules(linker_kernel_file, start, stop, 1); 1475 1476 /* 1477 * This is a once-off kinky bubble sort to resolve relocation 1478 * dependency requirements. 1479 */ 1480 restart: 1481 TAILQ_FOREACH(lf, &loaded_files, loaded) { 1482 error = linker_file_lookup_set(lf, MDT_SETNAME, &start, 1483 &stop, NULL); 1484 /* 1485 * First, look to see if we would successfully link with this 1486 * stuff. 1487 */ 1488 resolves = 1; /* unless we know otherwise */ 1489 if (!error) { 1490 for (mdp = start; mdp < stop; mdp++) { 1491 mp = *mdp; 1492 if (mp->md_type != MDT_DEPEND) 1493 continue; 1494 modname = mp->md_cval; 1495 verinfo = mp->md_data; 1496 for (nmdp = start; nmdp < stop; nmdp++) { 1497 nmp = *nmdp; 1498 if (nmp->md_type != MDT_VERSION) 1499 continue; 1500 nmodname = nmp->md_cval; 1501 if (strcmp(modname, nmodname) == 0) 1502 break; 1503 } 1504 if (nmdp < stop) /* it's a self reference */ 1505 continue; 1506 1507 /* 1508 * ok, the module isn't here yet, we 1509 * are not finished 1510 */ 1511 if (modlist_lookup2(modname, verinfo) == NULL) 1512 resolves = 0; 1513 } 1514 } 1515 /* 1516 * OK, if we found our modules, we can link. So, "provide" 1517 * the modules inside and add it to the end of the link order 1518 * list. 1519 */ 1520 if (resolves) { 1521 if (!error) { 1522 for (mdp = start; mdp < stop; mdp++) { 1523 mp = *mdp; 1524 if (mp->md_type != MDT_VERSION) 1525 continue; 1526 modname = mp->md_cval; 1527 nver = ((struct mod_version *) 1528 mp->md_data)->mv_version; 1529 if (modlist_lookup(modname, 1530 nver) != NULL) { 1531 printf("module %s already" 1532 " present!\n", modname); 1533 TAILQ_REMOVE(&loaded_files, 1534 lf, loaded); 1535 linker_file_unload(lf, 1536 LINKER_UNLOAD_FORCE); 1537 /* we changed tailq next ptr */ 1538 goto restart; 1539 } 1540 modlist_newmodule(modname, nver, lf); 1541 } 1542 } 1543 TAILQ_REMOVE(&loaded_files, lf, loaded); 1544 TAILQ_INSERT_TAIL(&depended_files, lf, loaded); 1545 /* 1546 * Since we provided modules, we need to restart the 1547 * sort so that the previous files that depend on us 1548 * have a chance. Also, we've busted the tailq next 1549 * pointer with the REMOVE. 1550 */ 1551 goto restart; 1552 } 1553 } 1554 1555 /* 1556 * At this point, we check to see what could not be resolved.. 1557 */ 1558 while ((lf = TAILQ_FIRST(&loaded_files)) != NULL) { 1559 TAILQ_REMOVE(&loaded_files, lf, loaded); 1560 printf("KLD file %s is missing dependencies\n", lf->filename); 1561 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 1562 } 1563 1564 /* 1565 * We made it. Finish off the linking in the order we determined. 1566 */ 1567 TAILQ_FOREACH_SAFE(lf, &depended_files, loaded, nlf) { 1568 if (linker_kernel_file) { 1569 linker_kernel_file->refs++; 1570 error = linker_file_add_dependency(lf, 1571 linker_kernel_file); 1572 if (error) 1573 panic("cannot add dependency"); 1574 } 1575 lf->userrefs++; /* so we can (try to) kldunload it */ 1576 error = linker_file_lookup_set(lf, MDT_SETNAME, &start, 1577 &stop, NULL); 1578 if (!error) { 1579 for (mdp = start; mdp < stop; mdp++) { 1580 mp = *mdp; 1581 if (mp->md_type != MDT_DEPEND) 1582 continue; 1583 modname = mp->md_cval; 1584 verinfo = mp->md_data; 1585 mod = modlist_lookup2(modname, verinfo); 1586 if (mod == NULL) { 1587 printf("KLD file %s - cannot find " 1588 "dependency \"%s\"\n", 1589 lf->filename, modname); 1590 goto fail; 1591 } 1592 /* Don't count self-dependencies */ 1593 if (lf == mod->container) 1594 continue; 1595 mod->container->refs++; 1596 error = linker_file_add_dependency(lf, 1597 mod->container); 1598 if (error) 1599 panic("cannot add dependency"); 1600 } 1601 } 1602 /* 1603 * Now do relocation etc using the symbol search paths 1604 * established by the dependencies 1605 */ 1606 error = LINKER_LINK_PRELOAD_FINISH(lf); 1607 if (error) { 1608 printf("KLD file %s - could not finalize loading\n", 1609 lf->filename); 1610 goto fail; 1611 } 1612 linker_file_register_modules(lf); 1613 if (linker_file_lookup_set(lf, "sysinit_set", &si_start, 1614 &si_stop, NULL) == 0) 1615 sysinit_add(si_start, si_stop); 1616 linker_file_register_sysctls(lf); 1617 lf->flags |= LINKER_FILE_LINKED; 1618 continue; 1619 fail: 1620 TAILQ_REMOVE(&depended_files, lf, loaded); 1621 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 1622 } 1623 sx_xunlock(&kld_sx); 1624 /* woohoo! we made it! */ 1625 } 1626 1627 SYSINIT(preload, SI_SUB_KLD, SI_ORDER_MIDDLE, linker_preload, 0); 1628 1629 /* 1630 * Search for a not-loaded module by name. 1631 * 1632 * Modules may be found in the following locations: 1633 * 1634 * - preloaded (result is just the module name) - on disk (result is full path 1635 * to module) 1636 * 1637 * If the module name is qualified in any way (contains path, etc.) the we 1638 * simply return a copy of it. 1639 * 1640 * The search path can be manipulated via sysctl. Note that we use the ';' 1641 * character as a separator to be consistent with the bootloader. 1642 */ 1643 1644 static char linker_hintfile[] = "linker.hints"; 1645 static char linker_path[MAXPATHLEN] = "/boot/kernel;/boot/modules"; 1646 1647 SYSCTL_STRING(_kern, OID_AUTO, module_path, CTLFLAG_RWTUN, linker_path, 1648 sizeof(linker_path), "module load search path"); 1649 1650 TUNABLE_STR("module_path", linker_path, sizeof(linker_path)); 1651 1652 static char *linker_ext_list[] = { 1653 "", 1654 ".ko", 1655 NULL 1656 }; 1657 1658 /* 1659 * Check if file actually exists either with or without extension listed in 1660 * the linker_ext_list. (probably should be generic for the rest of the 1661 * kernel) 1662 */ 1663 static char * 1664 linker_lookup_file(const char *path, int pathlen, const char *name, 1665 int namelen, struct vattr *vap) 1666 { 1667 struct nameidata nd; 1668 struct thread *td = curthread; /* XXX */ 1669 char *result, **cpp, *sep; 1670 int error, len, extlen, reclen, flags; 1671 enum vtype type; 1672 1673 extlen = 0; 1674 for (cpp = linker_ext_list; *cpp; cpp++) { 1675 len = strlen(*cpp); 1676 if (len > extlen) 1677 extlen = len; 1678 } 1679 extlen++; /* trailing '\0' */ 1680 sep = (path[pathlen - 1] != '/') ? "/" : ""; 1681 1682 reclen = pathlen + strlen(sep) + namelen + extlen + 1; 1683 result = malloc(reclen, M_LINKER, M_WAITOK); 1684 for (cpp = linker_ext_list; *cpp; cpp++) { 1685 snprintf(result, reclen, "%.*s%s%.*s%s", pathlen, path, sep, 1686 namelen, name, *cpp); 1687 /* 1688 * Attempt to open the file, and return the path if 1689 * we succeed and it's a regular file. 1690 */ 1691 NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, result, td); 1692 flags = FREAD; 1693 error = vn_open(&nd, &flags, 0, NULL); 1694 if (error == 0) { 1695 NDFREE(&nd, NDF_ONLY_PNBUF); 1696 type = nd.ni_vp->v_type; 1697 if (vap) 1698 VOP_GETATTR(nd.ni_vp, vap, td->td_ucred); 1699 VOP_UNLOCK(nd.ni_vp, 0); 1700 vn_close(nd.ni_vp, FREAD, td->td_ucred, td); 1701 if (type == VREG) 1702 return (result); 1703 } 1704 } 1705 free(result, M_LINKER); 1706 return (NULL); 1707 } 1708 1709 #define INT_ALIGN(base, ptr) ptr = \ 1710 (base) + (((ptr) - (base) + sizeof(int) - 1) & ~(sizeof(int) - 1)) 1711 1712 /* 1713 * Lookup KLD which contains requested module in the "linker.hints" file. If 1714 * version specification is available, then try to find the best KLD. 1715 * Otherwise just find the latest one. 1716 */ 1717 static char * 1718 linker_hints_lookup(const char *path, int pathlen, const char *modname, 1719 int modnamelen, struct mod_depend *verinfo) 1720 { 1721 struct thread *td = curthread; /* XXX */ 1722 struct ucred *cred = td ? td->td_ucred : NULL; 1723 struct nameidata nd; 1724 struct vattr vattr, mattr; 1725 u_char *hints = NULL; 1726 u_char *cp, *recptr, *bufend, *result, *best, *pathbuf, *sep; 1727 int error, ival, bestver, *intp, found, flags, clen, blen; 1728 ssize_t reclen; 1729 1730 result = NULL; 1731 bestver = found = 0; 1732 1733 sep = (path[pathlen - 1] != '/') ? "/" : ""; 1734 reclen = imax(modnamelen, strlen(linker_hintfile)) + pathlen + 1735 strlen(sep) + 1; 1736 pathbuf = malloc(reclen, M_LINKER, M_WAITOK); 1737 snprintf(pathbuf, reclen, "%.*s%s%s", pathlen, path, sep, 1738 linker_hintfile); 1739 1740 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, pathbuf, td); 1741 flags = FREAD; 1742 error = vn_open(&nd, &flags, 0, NULL); 1743 if (error) 1744 goto bad; 1745 NDFREE(&nd, NDF_ONLY_PNBUF); 1746 if (nd.ni_vp->v_type != VREG) 1747 goto bad; 1748 best = cp = NULL; 1749 error = VOP_GETATTR(nd.ni_vp, &vattr, cred); 1750 if (error) 1751 goto bad; 1752 /* 1753 * XXX: we need to limit this number to some reasonable value 1754 */ 1755 if (vattr.va_size > 100 * 1024) { 1756 printf("hints file too large %ld\n", (long)vattr.va_size); 1757 goto bad; 1758 } 1759 hints = malloc(vattr.va_size, M_TEMP, M_WAITOK); 1760 if (hints == NULL) 1761 goto bad; 1762 error = vn_rdwr(UIO_READ, nd.ni_vp, (caddr_t)hints, vattr.va_size, 0, 1763 UIO_SYSSPACE, IO_NODELOCKED, cred, NOCRED, &reclen, td); 1764 if (error) 1765 goto bad; 1766 VOP_UNLOCK(nd.ni_vp, 0); 1767 vn_close(nd.ni_vp, FREAD, cred, td); 1768 nd.ni_vp = NULL; 1769 if (reclen != 0) { 1770 printf("can't read %zd\n", reclen); 1771 goto bad; 1772 } 1773 intp = (int *)hints; 1774 ival = *intp++; 1775 if (ival != LINKER_HINTS_VERSION) { 1776 printf("hints file version mismatch %d\n", ival); 1777 goto bad; 1778 } 1779 bufend = hints + vattr.va_size; 1780 recptr = (u_char *)intp; 1781 clen = blen = 0; 1782 while (recptr < bufend && !found) { 1783 intp = (int *)recptr; 1784 reclen = *intp++; 1785 ival = *intp++; 1786 cp = (char *)intp; 1787 switch (ival) { 1788 case MDT_VERSION: 1789 clen = *cp++; 1790 if (clen != modnamelen || bcmp(cp, modname, clen) != 0) 1791 break; 1792 cp += clen; 1793 INT_ALIGN(hints, cp); 1794 ival = *(int *)cp; 1795 cp += sizeof(int); 1796 clen = *cp++; 1797 if (verinfo == NULL || 1798 ival == verinfo->md_ver_preferred) { 1799 found = 1; 1800 break; 1801 } 1802 if (ival >= verinfo->md_ver_minimum && 1803 ival <= verinfo->md_ver_maximum && 1804 ival > bestver) { 1805 bestver = ival; 1806 best = cp; 1807 blen = clen; 1808 } 1809 break; 1810 default: 1811 break; 1812 } 1813 recptr += reclen + sizeof(int); 1814 } 1815 /* 1816 * Finally check if KLD is in the place 1817 */ 1818 if (found) 1819 result = linker_lookup_file(path, pathlen, cp, clen, &mattr); 1820 else if (best) 1821 result = linker_lookup_file(path, pathlen, best, blen, &mattr); 1822 1823 /* 1824 * KLD is newer than hints file. What we should do now? 1825 */ 1826 if (result && timespeccmp(&mattr.va_mtime, &vattr.va_mtime, >)) 1827 printf("warning: KLD '%s' is newer than the linker.hints" 1828 " file\n", result); 1829 bad: 1830 free(pathbuf, M_LINKER); 1831 if (hints) 1832 free(hints, M_TEMP); 1833 if (nd.ni_vp != NULL) { 1834 VOP_UNLOCK(nd.ni_vp, 0); 1835 vn_close(nd.ni_vp, FREAD, cred, td); 1836 } 1837 /* 1838 * If nothing found or hints is absent - fallback to the old 1839 * way by using "kldname[.ko]" as module name. 1840 */ 1841 if (!found && !bestver && result == NULL) 1842 result = linker_lookup_file(path, pathlen, modname, 1843 modnamelen, NULL); 1844 return (result); 1845 } 1846 1847 /* 1848 * Lookup KLD which contains requested module in the all directories. 1849 */ 1850 static char * 1851 linker_search_module(const char *modname, int modnamelen, 1852 struct mod_depend *verinfo) 1853 { 1854 char *cp, *ep, *result; 1855 1856 /* 1857 * traverse the linker path 1858 */ 1859 for (cp = linker_path; *cp; cp = ep + 1) { 1860 /* find the end of this component */ 1861 for (ep = cp; (*ep != 0) && (*ep != ';'); ep++); 1862 result = linker_hints_lookup(cp, ep - cp, modname, 1863 modnamelen, verinfo); 1864 if (result != NULL) 1865 return (result); 1866 if (*ep == 0) 1867 break; 1868 } 1869 return (NULL); 1870 } 1871 1872 /* 1873 * Search for module in all directories listed in the linker_path. 1874 */ 1875 static char * 1876 linker_search_kld(const char *name) 1877 { 1878 char *cp, *ep, *result; 1879 int len; 1880 1881 /* qualified at all? */ 1882 if (strchr(name, '/')) 1883 return (strdup(name, M_LINKER)); 1884 1885 /* traverse the linker path */ 1886 len = strlen(name); 1887 for (ep = linker_path; *ep; ep++) { 1888 cp = ep; 1889 /* find the end of this component */ 1890 for (; *ep != 0 && *ep != ';'; ep++); 1891 result = linker_lookup_file(cp, ep - cp, name, len, NULL); 1892 if (result != NULL) 1893 return (result); 1894 } 1895 return (NULL); 1896 } 1897 1898 static const char * 1899 linker_basename(const char *path) 1900 { 1901 const char *filename; 1902 1903 filename = strrchr(path, '/'); 1904 if (filename == NULL) 1905 return path; 1906 if (filename[1]) 1907 filename++; 1908 return (filename); 1909 } 1910 1911 #ifdef HWPMC_HOOKS 1912 /* 1913 * Inform hwpmc about the set of kernel modules currently loaded. 1914 */ 1915 void * 1916 linker_hwpmc_list_objects(void) 1917 { 1918 linker_file_t lf; 1919 struct pmckern_map_in *kobase; 1920 int i, nmappings; 1921 1922 nmappings = 0; 1923 sx_slock(&kld_sx); 1924 TAILQ_FOREACH(lf, &linker_files, link) 1925 nmappings++; 1926 1927 /* Allocate nmappings + 1 entries. */ 1928 kobase = malloc((nmappings + 1) * sizeof(struct pmckern_map_in), 1929 M_LINKER, M_WAITOK | M_ZERO); 1930 i = 0; 1931 TAILQ_FOREACH(lf, &linker_files, link) { 1932 1933 /* Save the info for this linker file. */ 1934 kobase[i].pm_file = lf->filename; 1935 kobase[i].pm_address = (uintptr_t)lf->address; 1936 i++; 1937 } 1938 sx_sunlock(&kld_sx); 1939 1940 KASSERT(i > 0, ("linker_hpwmc_list_objects: no kernel objects?")); 1941 1942 /* The last entry of the malloced area comprises of all zeros. */ 1943 KASSERT(kobase[i].pm_file == NULL, 1944 ("linker_hwpmc_list_objects: last object not NULL")); 1945 1946 return ((void *)kobase); 1947 } 1948 #endif 1949 1950 /* 1951 * Find a file which contains given module and load it, if "parent" is not 1952 * NULL, register a reference to it. 1953 */ 1954 static int 1955 linker_load_module(const char *kldname, const char *modname, 1956 struct linker_file *parent, struct mod_depend *verinfo, 1957 struct linker_file **lfpp) 1958 { 1959 linker_file_t lfdep; 1960 const char *filename; 1961 char *pathname; 1962 int error; 1963 1964 sx_assert(&kld_sx, SA_XLOCKED); 1965 if (modname == NULL) { 1966 /* 1967 * We have to load KLD 1968 */ 1969 KASSERT(verinfo == NULL, ("linker_load_module: verinfo" 1970 " is not NULL")); 1971 pathname = linker_search_kld(kldname); 1972 } else { 1973 if (modlist_lookup2(modname, verinfo) != NULL) 1974 return (EEXIST); 1975 if (kldname != NULL) 1976 pathname = strdup(kldname, M_LINKER); 1977 else if (rootvnode == NULL) 1978 pathname = NULL; 1979 else 1980 /* 1981 * Need to find a KLD with required module 1982 */ 1983 pathname = linker_search_module(modname, 1984 strlen(modname), verinfo); 1985 } 1986 if (pathname == NULL) 1987 return (ENOENT); 1988 1989 /* 1990 * Can't load more than one file with the same basename XXX: 1991 * Actually it should be possible to have multiple KLDs with 1992 * the same basename but different path because they can 1993 * provide different versions of the same modules. 1994 */ 1995 filename = linker_basename(pathname); 1996 if (linker_find_file_by_name(filename)) 1997 error = EEXIST; 1998 else do { 1999 error = linker_load_file(pathname, &lfdep); 2000 if (error) 2001 break; 2002 if (modname && verinfo && 2003 modlist_lookup2(modname, verinfo) == NULL) { 2004 linker_file_unload(lfdep, LINKER_UNLOAD_FORCE); 2005 error = ENOENT; 2006 break; 2007 } 2008 if (parent) { 2009 error = linker_file_add_dependency(parent, lfdep); 2010 if (error) 2011 break; 2012 } 2013 if (lfpp) 2014 *lfpp = lfdep; 2015 } while (0); 2016 free(pathname, M_LINKER); 2017 return (error); 2018 } 2019 2020 /* 2021 * This routine is responsible for finding dependencies of userland initiated 2022 * kldload(2)'s of files. 2023 */ 2024 int 2025 linker_load_dependencies(linker_file_t lf) 2026 { 2027 linker_file_t lfdep; 2028 struct mod_metadata **start, **stop, **mdp, **nmdp; 2029 struct mod_metadata *mp, *nmp; 2030 struct mod_depend *verinfo; 2031 modlist_t mod; 2032 const char *modname, *nmodname; 2033 int ver, error = 0, count; 2034 2035 /* 2036 * All files are dependant on /kernel. 2037 */ 2038 sx_assert(&kld_sx, SA_XLOCKED); 2039 if (linker_kernel_file) { 2040 linker_kernel_file->refs++; 2041 error = linker_file_add_dependency(lf, linker_kernel_file); 2042 if (error) 2043 return (error); 2044 } 2045 if (linker_file_lookup_set(lf, MDT_SETNAME, &start, &stop, 2046 &count) != 0) 2047 return (0); 2048 for (mdp = start; mdp < stop; mdp++) { 2049 mp = *mdp; 2050 if (mp->md_type != MDT_VERSION) 2051 continue; 2052 modname = mp->md_cval; 2053 ver = ((struct mod_version *)mp->md_data)->mv_version; 2054 mod = modlist_lookup(modname, ver); 2055 if (mod != NULL) { 2056 printf("interface %s.%d already present in the KLD" 2057 " '%s'!\n", modname, ver, 2058 mod->container->filename); 2059 return (EEXIST); 2060 } 2061 } 2062 2063 for (mdp = start; mdp < stop; mdp++) { 2064 mp = *mdp; 2065 if (mp->md_type != MDT_DEPEND) 2066 continue; 2067 modname = mp->md_cval; 2068 verinfo = mp->md_data; 2069 nmodname = NULL; 2070 for (nmdp = start; nmdp < stop; nmdp++) { 2071 nmp = *nmdp; 2072 if (nmp->md_type != MDT_VERSION) 2073 continue; 2074 nmodname = nmp->md_cval; 2075 if (strcmp(modname, nmodname) == 0) 2076 break; 2077 } 2078 if (nmdp < stop)/* early exit, it's a self reference */ 2079 continue; 2080 mod = modlist_lookup2(modname, verinfo); 2081 if (mod) { /* woohoo, it's loaded already */ 2082 lfdep = mod->container; 2083 lfdep->refs++; 2084 error = linker_file_add_dependency(lf, lfdep); 2085 if (error) 2086 break; 2087 continue; 2088 } 2089 error = linker_load_module(NULL, modname, lf, verinfo, NULL); 2090 if (error) { 2091 printf("KLD %s: depends on %s - not available or" 2092 " version mismatch\n", lf->filename, modname); 2093 break; 2094 } 2095 } 2096 2097 if (error) 2098 return (error); 2099 linker_addmodules(lf, start, stop, 0); 2100 return (error); 2101 } 2102 2103 static int 2104 sysctl_kern_function_list_iterate(const char *name, void *opaque) 2105 { 2106 struct sysctl_req *req; 2107 2108 req = opaque; 2109 return (SYSCTL_OUT(req, name, strlen(name) + 1)); 2110 } 2111 2112 /* 2113 * Export a nul-separated, double-nul-terminated list of all function names 2114 * in the kernel. 2115 */ 2116 static int 2117 sysctl_kern_function_list(SYSCTL_HANDLER_ARGS) 2118 { 2119 linker_file_t lf; 2120 int error; 2121 2122 #ifdef MAC 2123 error = mac_kld_check_stat(req->td->td_ucred); 2124 if (error) 2125 return (error); 2126 #endif 2127 error = sysctl_wire_old_buffer(req, 0); 2128 if (error != 0) 2129 return (error); 2130 sx_xlock(&kld_sx); 2131 TAILQ_FOREACH(lf, &linker_files, link) { 2132 error = LINKER_EACH_FUNCTION_NAME(lf, 2133 sysctl_kern_function_list_iterate, req); 2134 if (error) { 2135 sx_xunlock(&kld_sx); 2136 return (error); 2137 } 2138 } 2139 sx_xunlock(&kld_sx); 2140 return (SYSCTL_OUT(req, "", 1)); 2141 } 2142 2143 SYSCTL_PROC(_kern, OID_AUTO, function_list, CTLTYPE_OPAQUE | CTLFLAG_RD, 2144 NULL, 0, sysctl_kern_function_list, "", "kernel function list"); 2145