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_RW | CTLFLAG_TUN, 70 &kld_debug, 0, "Set various levels of KLD debug"); 71 TUNABLE_INT("debug.kld_debug", &kld_debug); 72 #endif 73 74 /* 75 * static char *linker_search_path(const char *name, struct mod_depend 76 * *verinfo); 77 */ 78 static const char *linker_basename(const char *path); 79 80 /* 81 * Find a currently loaded file given its filename. 82 */ 83 static linker_file_t linker_find_file_by_name(const char* _filename); 84 85 /* 86 * Find a currently loaded file given its file id. 87 */ 88 static linker_file_t linker_find_file_by_id(int _fileid); 89 90 /* Metadata from the static kernel */ 91 SET_DECLARE(modmetadata_set, struct mod_metadata); 92 93 MALLOC_DEFINE(M_LINKER, "linker", "kernel linker"); 94 95 linker_file_t linker_kernel_file; 96 97 static struct sx kld_sx; /* kernel linker lock */ 98 99 /* 100 * Load counter used by clients to determine if a linker file has been 101 * re-loaded. This counter is incremented for each file load. 102 */ 103 static int loadcnt; 104 105 static linker_class_list_t classes; 106 static linker_file_list_t linker_files; 107 static int next_file_id = 1; 108 static int linker_no_more_classes = 0; 109 110 #define LINKER_GET_NEXT_FILE_ID(a) do { \ 111 linker_file_t lftmp; \ 112 \ 113 if (!cold) \ 114 sx_assert(&kld_sx, SA_XLOCKED); \ 115 retry: \ 116 TAILQ_FOREACH(lftmp, &linker_files, link) { \ 117 if (next_file_id == lftmp->id) { \ 118 next_file_id++; \ 119 goto retry; \ 120 } \ 121 } \ 122 (a) = next_file_id; \ 123 } while(0) 124 125 126 /* XXX wrong name; we're looking at version provision tags here, not modules */ 127 typedef TAILQ_HEAD(, modlist) modlisthead_t; 128 struct modlist { 129 TAILQ_ENTRY(modlist) link; /* chain together all modules */ 130 linker_file_t container; 131 const char *name; 132 int version; 133 }; 134 typedef struct modlist *modlist_t; 135 static modlisthead_t found_modules; 136 137 static int linker_file_add_dependency(linker_file_t file, 138 linker_file_t dep); 139 static caddr_t linker_file_lookup_symbol_internal(linker_file_t file, 140 const char* name, int deps); 141 static int linker_load_module(const char *kldname, 142 const char *modname, struct linker_file *parent, 143 struct mod_depend *verinfo, struct linker_file **lfpp); 144 static modlist_t modlist_lookup2(const char *name, struct mod_depend *verinfo); 145 146 static void 147 linker_init(void *arg) 148 { 149 150 sx_init(&kld_sx, "kernel linker"); 151 TAILQ_INIT(&classes); 152 TAILQ_INIT(&linker_files); 153 } 154 155 SYSINIT(linker, SI_SUB_KLD, SI_ORDER_FIRST, linker_init, 0); 156 157 static void 158 linker_stop_class_add(void *arg) 159 { 160 161 linker_no_more_classes = 1; 162 } 163 164 SYSINIT(linker_class, SI_SUB_KLD, SI_ORDER_ANY, linker_stop_class_add, NULL); 165 166 int 167 linker_add_class(linker_class_t lc) 168 { 169 170 /* 171 * We disallow any class registration past SI_ORDER_ANY 172 * of SI_SUB_KLD. We bump the reference count to keep the 173 * ops from being freed. 174 */ 175 if (linker_no_more_classes == 1) 176 return (EPERM); 177 kobj_class_compile((kobj_class_t) lc); 178 ((kobj_class_t)lc)->refs++; /* XXX: kobj_mtx */ 179 TAILQ_INSERT_TAIL(&classes, lc, link); 180 return (0); 181 } 182 183 static void 184 linker_file_sysinit(linker_file_t lf) 185 { 186 struct sysinit **start, **stop, **sipp, **xipp, *save; 187 188 KLD_DPF(FILE, ("linker_file_sysinit: calling SYSINITs for %s\n", 189 lf->filename)); 190 191 sx_assert(&kld_sx, SA_XLOCKED); 192 193 if (linker_file_lookup_set(lf, "sysinit_set", &start, &stop, NULL) != 0) 194 return; 195 /* 196 * Perform a bubble sort of the system initialization objects by 197 * their subsystem (primary key) and order (secondary key). 198 * 199 * Since some things care about execution order, this is the operation 200 * which ensures continued function. 201 */ 202 for (sipp = start; sipp < stop; sipp++) { 203 for (xipp = sipp + 1; xipp < stop; xipp++) { 204 if ((*sipp)->subsystem < (*xipp)->subsystem || 205 ((*sipp)->subsystem == (*xipp)->subsystem && 206 (*sipp)->order <= (*xipp)->order)) 207 continue; /* skip */ 208 save = *sipp; 209 *sipp = *xipp; 210 *xipp = save; 211 } 212 } 213 214 /* 215 * Traverse the (now) ordered list of system initialization tasks. 216 * Perform each task, and continue on to the next task. 217 */ 218 sx_xunlock(&kld_sx); 219 mtx_lock(&Giant); 220 for (sipp = start; sipp < stop; sipp++) { 221 if ((*sipp)->subsystem == SI_SUB_DUMMY) 222 continue; /* skip dummy task(s) */ 223 224 /* Call function */ 225 (*((*sipp)->func)) ((*sipp)->udata); 226 } 227 mtx_unlock(&Giant); 228 sx_xlock(&kld_sx); 229 } 230 231 static void 232 linker_file_sysuninit(linker_file_t lf) 233 { 234 struct sysinit **start, **stop, **sipp, **xipp, *save; 235 236 KLD_DPF(FILE, ("linker_file_sysuninit: calling SYSUNINITs for %s\n", 237 lf->filename)); 238 239 sx_assert(&kld_sx, SA_XLOCKED); 240 241 if (linker_file_lookup_set(lf, "sysuninit_set", &start, &stop, 242 NULL) != 0) 243 return; 244 245 /* 246 * Perform a reverse bubble sort of the system initialization objects 247 * by their subsystem (primary key) and order (secondary key). 248 * 249 * Since some things care about execution order, this is the operation 250 * which ensures continued function. 251 */ 252 for (sipp = start; sipp < stop; sipp++) { 253 for (xipp = sipp + 1; xipp < stop; xipp++) { 254 if ((*sipp)->subsystem > (*xipp)->subsystem || 255 ((*sipp)->subsystem == (*xipp)->subsystem && 256 (*sipp)->order >= (*xipp)->order)) 257 continue; /* skip */ 258 save = *sipp; 259 *sipp = *xipp; 260 *xipp = save; 261 } 262 } 263 264 /* 265 * Traverse the (now) ordered list of system initialization tasks. 266 * Perform each task, and continue on to the next task. 267 */ 268 sx_xunlock(&kld_sx); 269 mtx_lock(&Giant); 270 for (sipp = start; sipp < stop; sipp++) { 271 if ((*sipp)->subsystem == SI_SUB_DUMMY) 272 continue; /* skip dummy task(s) */ 273 274 /* Call function */ 275 (*((*sipp)->func)) ((*sipp)->udata); 276 } 277 mtx_unlock(&Giant); 278 sx_xlock(&kld_sx); 279 } 280 281 static void 282 linker_file_register_sysctls(linker_file_t lf) 283 { 284 struct sysctl_oid **start, **stop, **oidp; 285 286 KLD_DPF(FILE, 287 ("linker_file_register_sysctls: registering SYSCTLs for %s\n", 288 lf->filename)); 289 290 sx_assert(&kld_sx, SA_XLOCKED); 291 292 if (linker_file_lookup_set(lf, "sysctl_set", &start, &stop, NULL) != 0) 293 return; 294 295 sx_xunlock(&kld_sx); 296 sysctl_lock(); 297 for (oidp = start; oidp < stop; oidp++) 298 sysctl_register_oid(*oidp); 299 sysctl_unlock(); 300 sx_xlock(&kld_sx); 301 } 302 303 static void 304 linker_file_unregister_sysctls(linker_file_t lf) 305 { 306 struct sysctl_oid **start, **stop, **oidp; 307 308 KLD_DPF(FILE, ("linker_file_unregister_sysctls: unregistering SYSCTLs" 309 " for %s\n", lf->filename)); 310 311 sx_assert(&kld_sx, SA_XLOCKED); 312 313 if (linker_file_lookup_set(lf, "sysctl_set", &start, &stop, NULL) != 0) 314 return; 315 316 sx_xunlock(&kld_sx); 317 sysctl_lock(); 318 for (oidp = start; oidp < stop; oidp++) 319 sysctl_unregister_oid(*oidp); 320 sysctl_unlock(); 321 sx_xlock(&kld_sx); 322 } 323 324 static int 325 linker_file_register_modules(linker_file_t lf) 326 { 327 struct mod_metadata **start, **stop, **mdp; 328 const moduledata_t *moddata; 329 int first_error, error; 330 331 KLD_DPF(FILE, ("linker_file_register_modules: registering modules" 332 " in %s\n", lf->filename)); 333 334 sx_assert(&kld_sx, SA_XLOCKED); 335 336 if (linker_file_lookup_set(lf, "modmetadata_set", &start, 337 &stop, NULL) != 0) { 338 /* 339 * This fallback should be unnecessary, but if we get booted 340 * from boot2 instead of loader and we are missing our 341 * metadata then we have to try the best we can. 342 */ 343 if (lf == linker_kernel_file) { 344 start = SET_BEGIN(modmetadata_set); 345 stop = SET_LIMIT(modmetadata_set); 346 } else 347 return (0); 348 } 349 first_error = 0; 350 for (mdp = start; mdp < stop; mdp++) { 351 if ((*mdp)->md_type != MDT_MODULE) 352 continue; 353 moddata = (*mdp)->md_data; 354 KLD_DPF(FILE, ("Registering module %s in %s\n", 355 moddata->name, lf->filename)); 356 error = module_register(moddata, lf); 357 if (error) { 358 printf("Module %s failed to register: %d\n", 359 moddata->name, error); 360 if (first_error == 0) 361 first_error = error; 362 } 363 } 364 return (first_error); 365 } 366 367 static void 368 linker_init_kernel_modules(void) 369 { 370 371 sx_xlock(&kld_sx); 372 linker_file_register_modules(linker_kernel_file); 373 sx_xunlock(&kld_sx); 374 } 375 376 SYSINIT(linker_kernel, SI_SUB_KLD, SI_ORDER_ANY, linker_init_kernel_modules, 377 0); 378 379 static int 380 linker_load_file(const char *filename, linker_file_t *result) 381 { 382 linker_class_t lc; 383 linker_file_t lf; 384 int foundfile, error, modules; 385 386 /* Refuse to load modules if securelevel raised */ 387 if (prison0.pr_securelevel > 0) 388 return (EPERM); 389 390 sx_assert(&kld_sx, SA_XLOCKED); 391 lf = linker_find_file_by_name(filename); 392 if (lf) { 393 KLD_DPF(FILE, ("linker_load_file: file %s is already loaded," 394 " incrementing refs\n", filename)); 395 *result = lf; 396 lf->refs++; 397 return (0); 398 } 399 foundfile = 0; 400 error = 0; 401 402 /* 403 * We do not need to protect (lock) classes here because there is 404 * no class registration past startup (SI_SUB_KLD, SI_ORDER_ANY) 405 * and there is no class deregistration mechanism at this time. 406 */ 407 TAILQ_FOREACH(lc, &classes, link) { 408 KLD_DPF(FILE, ("linker_load_file: trying to load %s\n", 409 filename)); 410 error = LINKER_LOAD_FILE(lc, filename, &lf); 411 /* 412 * If we got something other than ENOENT, then it exists but 413 * we cannot load it for some other reason. 414 */ 415 if (error != ENOENT) 416 foundfile = 1; 417 if (lf) { 418 error = linker_file_register_modules(lf); 419 if (error == EEXIST) { 420 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 421 return (error); 422 } 423 modules = !TAILQ_EMPTY(&lf->modules); 424 linker_file_register_sysctls(lf); 425 linker_file_sysinit(lf); 426 lf->flags |= LINKER_FILE_LINKED; 427 428 /* 429 * If all of the modules in this file failed 430 * to load, unload the file and return an 431 * error of ENOEXEC. 432 */ 433 if (modules && TAILQ_EMPTY(&lf->modules)) { 434 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 435 return (ENOEXEC); 436 } 437 EVENTHANDLER_INVOKE(kld_load, lf); 438 *result = lf; 439 return (0); 440 } 441 } 442 /* 443 * Less than ideal, but tells the user whether it failed to load or 444 * the module was not found. 445 */ 446 if (foundfile) { 447 448 /* 449 * If the file type has not been recognized by the last try 450 * printout a message before to fail. 451 */ 452 if (error == ENOSYS) 453 printf("linker_load_file: Unsupported file type\n"); 454 455 /* 456 * Format not recognized or otherwise unloadable. 457 * When loading a module that is statically built into 458 * the kernel EEXIST percolates back up as the return 459 * value. Preserve this so that apps like sysinstall 460 * can recognize this special case and not post bogus 461 * dialog boxes. 462 */ 463 if (error != EEXIST) 464 error = ENOEXEC; 465 } else 466 error = ENOENT; /* Nothing found */ 467 return (error); 468 } 469 470 int 471 linker_reference_module(const char *modname, struct mod_depend *verinfo, 472 linker_file_t *result) 473 { 474 modlist_t mod; 475 int error; 476 477 sx_xlock(&kld_sx); 478 if ((mod = modlist_lookup2(modname, verinfo)) != NULL) { 479 *result = mod->container; 480 (*result)->refs++; 481 sx_xunlock(&kld_sx); 482 return (0); 483 } 484 485 error = linker_load_module(NULL, modname, NULL, verinfo, result); 486 sx_xunlock(&kld_sx); 487 return (error); 488 } 489 490 int 491 linker_release_module(const char *modname, struct mod_depend *verinfo, 492 linker_file_t lf) 493 { 494 modlist_t mod; 495 int error; 496 497 sx_xlock(&kld_sx); 498 if (lf == NULL) { 499 KASSERT(modname != NULL, 500 ("linker_release_module: no file or name")); 501 mod = modlist_lookup2(modname, verinfo); 502 if (mod == NULL) { 503 sx_xunlock(&kld_sx); 504 return (ESRCH); 505 } 506 lf = mod->container; 507 } else 508 KASSERT(modname == NULL && verinfo == NULL, 509 ("linker_release_module: both file and name")); 510 error = linker_file_unload(lf, LINKER_UNLOAD_NORMAL); 511 sx_xunlock(&kld_sx); 512 return (error); 513 } 514 515 static linker_file_t 516 linker_find_file_by_name(const char *filename) 517 { 518 linker_file_t lf; 519 char *koname; 520 521 koname = malloc(strlen(filename) + 4, M_LINKER, M_WAITOK); 522 sprintf(koname, "%s.ko", filename); 523 524 sx_assert(&kld_sx, SA_XLOCKED); 525 TAILQ_FOREACH(lf, &linker_files, link) { 526 if (strcmp(lf->filename, koname) == 0) 527 break; 528 if (strcmp(lf->filename, filename) == 0) 529 break; 530 } 531 free(koname, M_LINKER); 532 return (lf); 533 } 534 535 static linker_file_t 536 linker_find_file_by_id(int fileid) 537 { 538 linker_file_t lf; 539 540 sx_assert(&kld_sx, SA_XLOCKED); 541 TAILQ_FOREACH(lf, &linker_files, link) 542 if (lf->id == fileid && lf->flags & LINKER_FILE_LINKED) 543 break; 544 return (lf); 545 } 546 547 int 548 linker_file_foreach(linker_predicate_t *predicate, void *context) 549 { 550 linker_file_t lf; 551 int retval = 0; 552 553 sx_xlock(&kld_sx); 554 TAILQ_FOREACH(lf, &linker_files, link) { 555 retval = predicate(lf, context); 556 if (retval != 0) 557 break; 558 } 559 sx_xunlock(&kld_sx); 560 return (retval); 561 } 562 563 linker_file_t 564 linker_make_file(const char *pathname, linker_class_t lc) 565 { 566 linker_file_t lf; 567 const char *filename; 568 569 if (!cold) 570 sx_assert(&kld_sx, SA_XLOCKED); 571 filename = linker_basename(pathname); 572 573 KLD_DPF(FILE, ("linker_make_file: new file, filename='%s' for pathname='%s'\n", filename, pathname)); 574 lf = (linker_file_t)kobj_create((kobj_class_t)lc, M_LINKER, M_WAITOK); 575 if (lf == NULL) 576 return (NULL); 577 lf->refs = 1; 578 lf->userrefs = 0; 579 lf->flags = 0; 580 lf->filename = strdup(filename, M_LINKER); 581 lf->pathname = strdup(pathname, M_LINKER); 582 LINKER_GET_NEXT_FILE_ID(lf->id); 583 lf->ndeps = 0; 584 lf->deps = NULL; 585 lf->loadcnt = ++loadcnt; 586 STAILQ_INIT(&lf->common); 587 TAILQ_INIT(&lf->modules); 588 TAILQ_INSERT_TAIL(&linker_files, lf, link); 589 return (lf); 590 } 591 592 int 593 linker_file_unload(linker_file_t file, int flags) 594 { 595 module_t mod, next; 596 modlist_t ml, nextml; 597 struct common_symbol *cp; 598 int error, i; 599 600 /* Refuse to unload modules if securelevel raised. */ 601 if (prison0.pr_securelevel > 0) 602 return (EPERM); 603 604 sx_assert(&kld_sx, SA_XLOCKED); 605 KLD_DPF(FILE, ("linker_file_unload: lf->refs=%d\n", file->refs)); 606 607 /* Easy case of just dropping a reference. */ 608 if (file->refs > 1) { 609 file->refs--; 610 return (0); 611 } 612 613 /* Give eventhandlers a chance to prevent the unload. */ 614 error = 0; 615 EVENTHANDLER_INVOKE(kld_unload_try, file, &error); 616 if (error != 0) 617 return (EBUSY); 618 619 KLD_DPF(FILE, ("linker_file_unload: file is unloading," 620 " informing modules\n")); 621 622 /* 623 * Quiesce all the modules to give them a chance to veto the unload. 624 */ 625 MOD_SLOCK; 626 for (mod = TAILQ_FIRST(&file->modules); mod; 627 mod = module_getfnext(mod)) { 628 629 error = module_quiesce(mod); 630 if (error != 0 && flags != LINKER_UNLOAD_FORCE) { 631 KLD_DPF(FILE, ("linker_file_unload: module %s" 632 " vetoed unload\n", module_getname(mod))); 633 /* 634 * XXX: Do we need to tell all the quiesced modules 635 * that they can resume work now via a new module 636 * event? 637 */ 638 MOD_SUNLOCK; 639 return (error); 640 } 641 } 642 MOD_SUNLOCK; 643 644 /* 645 * Inform any modules associated with this file that they are 646 * being unloaded. 647 */ 648 MOD_XLOCK; 649 for (mod = TAILQ_FIRST(&file->modules); mod; mod = next) { 650 next = module_getfnext(mod); 651 MOD_XUNLOCK; 652 653 /* 654 * Give the module a chance to veto the unload. 655 */ 656 if ((error = module_unload(mod)) != 0) { 657 #ifdef KLD_DEBUG 658 MOD_SLOCK; 659 KLD_DPF(FILE, ("linker_file_unload: module %s" 660 " failed unload\n", module_getname(mod))); 661 MOD_SUNLOCK; 662 #endif 663 return (error); 664 } 665 MOD_XLOCK; 666 module_release(mod); 667 } 668 MOD_XUNLOCK; 669 670 TAILQ_FOREACH_SAFE(ml, &found_modules, link, nextml) { 671 if (ml->container == file) { 672 TAILQ_REMOVE(&found_modules, ml, link); 673 free(ml, M_LINKER); 674 } 675 } 676 677 /* 678 * Don't try to run SYSUNINITs if we are unloaded due to a 679 * link error. 680 */ 681 if (file->flags & LINKER_FILE_LINKED) { 682 file->flags &= ~LINKER_FILE_LINKED; 683 linker_file_sysuninit(file); 684 linker_file_unregister_sysctls(file); 685 } 686 TAILQ_REMOVE(&linker_files, file, link); 687 688 if (file->deps) { 689 for (i = 0; i < file->ndeps; i++) 690 linker_file_unload(file->deps[i], flags); 691 free(file->deps, M_LINKER); 692 file->deps = NULL; 693 } 694 while ((cp = STAILQ_FIRST(&file->common)) != NULL) { 695 STAILQ_REMOVE_HEAD(&file->common, link); 696 free(cp, M_LINKER); 697 } 698 699 LINKER_UNLOAD(file); 700 701 EVENTHANDLER_INVOKE(kld_unload, file->filename, file->address, 702 file->size); 703 704 if (file->filename) { 705 free(file->filename, M_LINKER); 706 file->filename = NULL; 707 } 708 if (file->pathname) { 709 free(file->pathname, M_LINKER); 710 file->pathname = NULL; 711 } 712 kobj_delete((kobj_t) file, M_LINKER); 713 return (0); 714 } 715 716 int 717 linker_ctf_get(linker_file_t file, linker_ctf_t *lc) 718 { 719 return (LINKER_CTF_GET(file, lc)); 720 } 721 722 static int 723 linker_file_add_dependency(linker_file_t file, linker_file_t dep) 724 { 725 linker_file_t *newdeps; 726 727 sx_assert(&kld_sx, SA_XLOCKED); 728 file->deps = realloc(file->deps, (file->ndeps + 1) * sizeof(*newdeps), 729 M_LINKER, M_WAITOK | M_ZERO); 730 file->deps[file->ndeps] = dep; 731 file->ndeps++; 732 KLD_DPF(FILE, ("linker_file_add_dependency:" 733 " adding %s as dependency for %s\n", 734 dep->filename, file->filename)); 735 return (0); 736 } 737 738 /* 739 * Locate a linker set and its contents. This is a helper function to avoid 740 * linker_if.h exposure elsewhere. Note: firstp and lastp are really void **. 741 * This function is used in this file so we can avoid having lots of (void **) 742 * casts. 743 */ 744 int 745 linker_file_lookup_set(linker_file_t file, const char *name, 746 void *firstp, void *lastp, int *countp) 747 { 748 749 sx_assert(&kld_sx, SA_LOCKED); 750 return (LINKER_LOOKUP_SET(file, name, firstp, lastp, countp)); 751 } 752 753 /* 754 * List all functions in a file. 755 */ 756 int 757 linker_file_function_listall(linker_file_t lf, 758 linker_function_nameval_callback_t callback_func, void *arg) 759 { 760 return (LINKER_EACH_FUNCTION_NAMEVAL(lf, callback_func, arg)); 761 } 762 763 caddr_t 764 linker_file_lookup_symbol(linker_file_t file, const char *name, int deps) 765 { 766 caddr_t sym; 767 int locked; 768 769 locked = sx_xlocked(&kld_sx); 770 if (!locked) 771 sx_xlock(&kld_sx); 772 sym = linker_file_lookup_symbol_internal(file, name, deps); 773 if (!locked) 774 sx_xunlock(&kld_sx); 775 return (sym); 776 } 777 778 static caddr_t 779 linker_file_lookup_symbol_internal(linker_file_t file, const char *name, 780 int deps) 781 { 782 c_linker_sym_t sym; 783 linker_symval_t symval; 784 caddr_t address; 785 size_t common_size = 0; 786 int i; 787 788 sx_assert(&kld_sx, SA_XLOCKED); 789 KLD_DPF(SYM, ("linker_file_lookup_symbol: file=%p, name=%s, deps=%d\n", 790 file, name, deps)); 791 792 if (LINKER_LOOKUP_SYMBOL(file, name, &sym) == 0) { 793 LINKER_SYMBOL_VALUES(file, sym, &symval); 794 if (symval.value == 0) 795 /* 796 * For commons, first look them up in the 797 * dependencies and only allocate space if not found 798 * there. 799 */ 800 common_size = symval.size; 801 else { 802 KLD_DPF(SYM, ("linker_file_lookup_symbol: symbol" 803 ".value=%p\n", symval.value)); 804 return (symval.value); 805 } 806 } 807 if (deps) { 808 for (i = 0; i < file->ndeps; i++) { 809 address = linker_file_lookup_symbol_internal( 810 file->deps[i], name, 0); 811 if (address) { 812 KLD_DPF(SYM, ("linker_file_lookup_symbol:" 813 " deps value=%p\n", address)); 814 return (address); 815 } 816 } 817 } 818 if (common_size > 0) { 819 /* 820 * This is a common symbol which was not found in the 821 * dependencies. We maintain a simple common symbol table in 822 * the file object. 823 */ 824 struct common_symbol *cp; 825 826 STAILQ_FOREACH(cp, &file->common, link) { 827 if (strcmp(cp->name, name) == 0) { 828 KLD_DPF(SYM, ("linker_file_lookup_symbol:" 829 " old common value=%p\n", cp->address)); 830 return (cp->address); 831 } 832 } 833 /* 834 * Round the symbol size up to align. 835 */ 836 common_size = (common_size + sizeof(int) - 1) & -sizeof(int); 837 cp = malloc(sizeof(struct common_symbol) 838 + common_size + strlen(name) + 1, M_LINKER, 839 M_WAITOK | M_ZERO); 840 cp->address = (caddr_t)(cp + 1); 841 cp->name = cp->address + common_size; 842 strcpy(cp->name, name); 843 bzero(cp->address, common_size); 844 STAILQ_INSERT_TAIL(&file->common, cp, link); 845 846 KLD_DPF(SYM, ("linker_file_lookup_symbol: new common" 847 " value=%p\n", cp->address)); 848 return (cp->address); 849 } 850 KLD_DPF(SYM, ("linker_file_lookup_symbol: fail\n")); 851 return (0); 852 } 853 854 /* 855 * Both DDB and stack(9) rely on the kernel linker to provide forward and 856 * backward lookup of symbols. However, DDB and sometimes stack(9) need to 857 * do this in a lockfree manner. We provide a set of internal helper 858 * routines to perform these operations without locks, and then wrappers that 859 * optionally lock. 860 * 861 * linker_debug_lookup() is ifdef DDB as currently it's only used by DDB. 862 */ 863 #ifdef DDB 864 static int 865 linker_debug_lookup(const char *symstr, c_linker_sym_t *sym) 866 { 867 linker_file_t lf; 868 869 TAILQ_FOREACH(lf, &linker_files, link) { 870 if (LINKER_LOOKUP_SYMBOL(lf, symstr, sym) == 0) 871 return (0); 872 } 873 return (ENOENT); 874 } 875 #endif 876 877 static int 878 linker_debug_search_symbol(caddr_t value, c_linker_sym_t *sym, long *diffp) 879 { 880 linker_file_t lf; 881 c_linker_sym_t best, es; 882 u_long diff, bestdiff, off; 883 884 best = 0; 885 off = (uintptr_t)value; 886 bestdiff = off; 887 TAILQ_FOREACH(lf, &linker_files, link) { 888 if (LINKER_SEARCH_SYMBOL(lf, value, &es, &diff) != 0) 889 continue; 890 if (es != 0 && diff < bestdiff) { 891 best = es; 892 bestdiff = diff; 893 } 894 if (bestdiff == 0) 895 break; 896 } 897 if (best) { 898 *sym = best; 899 *diffp = bestdiff; 900 return (0); 901 } else { 902 *sym = 0; 903 *diffp = off; 904 return (ENOENT); 905 } 906 } 907 908 static int 909 linker_debug_symbol_values(c_linker_sym_t sym, linker_symval_t *symval) 910 { 911 linker_file_t lf; 912 913 TAILQ_FOREACH(lf, &linker_files, link) { 914 if (LINKER_SYMBOL_VALUES(lf, sym, symval) == 0) 915 return (0); 916 } 917 return (ENOENT); 918 } 919 920 static int 921 linker_debug_search_symbol_name(caddr_t value, char *buf, u_int buflen, 922 long *offset) 923 { 924 linker_symval_t symval; 925 c_linker_sym_t sym; 926 int error; 927 928 *offset = 0; 929 error = linker_debug_search_symbol(value, &sym, offset); 930 if (error) 931 return (error); 932 error = linker_debug_symbol_values(sym, &symval); 933 if (error) 934 return (error); 935 strlcpy(buf, symval.name, buflen); 936 return (0); 937 } 938 939 /* 940 * DDB Helpers. DDB has to look across multiple files with their own symbol 941 * tables and string tables. 942 * 943 * Note that we do not obey list locking protocols here. We really don't need 944 * DDB to hang because somebody's got the lock held. We'll take the chance 945 * that the files list is inconsistant instead. 946 */ 947 #ifdef DDB 948 int 949 linker_ddb_lookup(const char *symstr, c_linker_sym_t *sym) 950 { 951 952 return (linker_debug_lookup(symstr, sym)); 953 } 954 #endif 955 956 int 957 linker_ddb_search_symbol(caddr_t value, c_linker_sym_t *sym, long *diffp) 958 { 959 960 return (linker_debug_search_symbol(value, sym, diffp)); 961 } 962 963 int 964 linker_ddb_symbol_values(c_linker_sym_t sym, linker_symval_t *symval) 965 { 966 967 return (linker_debug_symbol_values(sym, symval)); 968 } 969 970 int 971 linker_ddb_search_symbol_name(caddr_t value, char *buf, u_int buflen, 972 long *offset) 973 { 974 975 return (linker_debug_search_symbol_name(value, buf, buflen, offset)); 976 } 977 978 /* 979 * stack(9) helper for non-debugging environemnts. Unlike DDB helpers, we do 980 * obey locking protocols, and offer a significantly less complex interface. 981 */ 982 int 983 linker_search_symbol_name(caddr_t value, char *buf, u_int buflen, 984 long *offset) 985 { 986 int error; 987 988 sx_xlock(&kld_sx); 989 error = linker_debug_search_symbol_name(value, buf, buflen, offset); 990 sx_xunlock(&kld_sx); 991 return (error); 992 } 993 994 /* 995 * Syscalls. 996 */ 997 int 998 kern_kldload(struct thread *td, const char *file, int *fileid) 999 { 1000 const char *kldname, *modname; 1001 linker_file_t lf; 1002 int error; 1003 1004 if ((error = securelevel_gt(td->td_ucred, 0)) != 0) 1005 return (error); 1006 1007 if ((error = priv_check(td, PRIV_KLD_LOAD)) != 0) 1008 return (error); 1009 1010 /* 1011 * It is possible that kldloaded module will attach a new ifnet, 1012 * so vnet context must be set when this ocurs. 1013 */ 1014 CURVNET_SET(TD_TO_VNET(td)); 1015 1016 /* 1017 * If file does not contain a qualified name or any dot in it 1018 * (kldname.ko, or kldname.ver.ko) treat it as an interface 1019 * name. 1020 */ 1021 if (strchr(file, '/') || strchr(file, '.')) { 1022 kldname = file; 1023 modname = NULL; 1024 } else { 1025 kldname = NULL; 1026 modname = file; 1027 } 1028 1029 sx_xlock(&kld_sx); 1030 error = linker_load_module(kldname, modname, NULL, NULL, &lf); 1031 if (error) { 1032 sx_xunlock(&kld_sx); 1033 goto done; 1034 } 1035 lf->userrefs++; 1036 if (fileid != NULL) 1037 *fileid = lf->id; 1038 sx_xunlock(&kld_sx); 1039 1040 done: 1041 CURVNET_RESTORE(); 1042 return (error); 1043 } 1044 1045 int 1046 sys_kldload(struct thread *td, struct kldload_args *uap) 1047 { 1048 char *pathname = NULL; 1049 int error, fileid; 1050 1051 td->td_retval[0] = -1; 1052 1053 pathname = malloc(MAXPATHLEN, M_TEMP, M_WAITOK); 1054 error = copyinstr(uap->file, pathname, MAXPATHLEN, NULL); 1055 if (error == 0) { 1056 error = kern_kldload(td, pathname, &fileid); 1057 if (error == 0) 1058 td->td_retval[0] = fileid; 1059 } 1060 free(pathname, M_TEMP); 1061 return (error); 1062 } 1063 1064 int 1065 kern_kldunload(struct thread *td, int fileid, int flags) 1066 { 1067 linker_file_t lf; 1068 int error = 0; 1069 1070 if ((error = securelevel_gt(td->td_ucred, 0)) != 0) 1071 return (error); 1072 1073 if ((error = priv_check(td, PRIV_KLD_UNLOAD)) != 0) 1074 return (error); 1075 1076 CURVNET_SET(TD_TO_VNET(td)); 1077 sx_xlock(&kld_sx); 1078 lf = linker_find_file_by_id(fileid); 1079 if (lf) { 1080 KLD_DPF(FILE, ("kldunload: lf->userrefs=%d\n", lf->userrefs)); 1081 1082 if (lf->userrefs == 0) { 1083 /* 1084 * XXX: maybe LINKER_UNLOAD_FORCE should override ? 1085 */ 1086 printf("kldunload: attempt to unload file that was" 1087 " loaded by the kernel\n"); 1088 error = EBUSY; 1089 } else { 1090 lf->userrefs--; 1091 error = linker_file_unload(lf, flags); 1092 if (error) 1093 lf->userrefs++; 1094 } 1095 } else 1096 error = ENOENT; 1097 sx_xunlock(&kld_sx); 1098 1099 CURVNET_RESTORE(); 1100 return (error); 1101 } 1102 1103 int 1104 sys_kldunload(struct thread *td, struct kldunload_args *uap) 1105 { 1106 1107 return (kern_kldunload(td, uap->fileid, LINKER_UNLOAD_NORMAL)); 1108 } 1109 1110 int 1111 sys_kldunloadf(struct thread *td, struct kldunloadf_args *uap) 1112 { 1113 1114 if (uap->flags != LINKER_UNLOAD_NORMAL && 1115 uap->flags != LINKER_UNLOAD_FORCE) 1116 return (EINVAL); 1117 return (kern_kldunload(td, uap->fileid, uap->flags)); 1118 } 1119 1120 int 1121 sys_kldfind(struct thread *td, struct kldfind_args *uap) 1122 { 1123 char *pathname; 1124 const char *filename; 1125 linker_file_t lf; 1126 int error; 1127 1128 #ifdef MAC 1129 error = mac_kld_check_stat(td->td_ucred); 1130 if (error) 1131 return (error); 1132 #endif 1133 1134 td->td_retval[0] = -1; 1135 1136 pathname = malloc(MAXPATHLEN, M_TEMP, M_WAITOK); 1137 if ((error = copyinstr(uap->file, pathname, MAXPATHLEN, NULL)) != 0) 1138 goto out; 1139 1140 filename = linker_basename(pathname); 1141 sx_xlock(&kld_sx); 1142 lf = linker_find_file_by_name(filename); 1143 if (lf) 1144 td->td_retval[0] = lf->id; 1145 else 1146 error = ENOENT; 1147 sx_xunlock(&kld_sx); 1148 out: 1149 free(pathname, M_TEMP); 1150 return (error); 1151 } 1152 1153 int 1154 sys_kldnext(struct thread *td, struct kldnext_args *uap) 1155 { 1156 linker_file_t lf; 1157 int error = 0; 1158 1159 #ifdef MAC 1160 error = mac_kld_check_stat(td->td_ucred); 1161 if (error) 1162 return (error); 1163 #endif 1164 1165 sx_xlock(&kld_sx); 1166 if (uap->fileid == 0) 1167 lf = TAILQ_FIRST(&linker_files); 1168 else { 1169 lf = linker_find_file_by_id(uap->fileid); 1170 if (lf == NULL) { 1171 error = ENOENT; 1172 goto out; 1173 } 1174 lf = TAILQ_NEXT(lf, link); 1175 } 1176 1177 /* Skip partially loaded files. */ 1178 while (lf != NULL && !(lf->flags & LINKER_FILE_LINKED)) 1179 lf = TAILQ_NEXT(lf, link); 1180 1181 if (lf) 1182 td->td_retval[0] = lf->id; 1183 else 1184 td->td_retval[0] = 0; 1185 out: 1186 sx_xunlock(&kld_sx); 1187 return (error); 1188 } 1189 1190 int 1191 sys_kldstat(struct thread *td, struct kldstat_args *uap) 1192 { 1193 struct kld_file_stat stat; 1194 int error, version; 1195 1196 /* 1197 * Check the version of the user's structure. 1198 */ 1199 if ((error = copyin(&uap->stat->version, &version, sizeof(version))) 1200 != 0) 1201 return (error); 1202 if (version != sizeof(struct kld_file_stat_1) && 1203 version != sizeof(struct kld_file_stat)) 1204 return (EINVAL); 1205 1206 error = kern_kldstat(td, uap->fileid, &stat); 1207 if (error != 0) 1208 return (error); 1209 return (copyout(&stat, uap->stat, version)); 1210 } 1211 1212 int 1213 kern_kldstat(struct thread *td, int fileid, struct kld_file_stat *stat) 1214 { 1215 linker_file_t lf; 1216 int namelen; 1217 #ifdef MAC 1218 int error; 1219 1220 error = mac_kld_check_stat(td->td_ucred); 1221 if (error) 1222 return (error); 1223 #endif 1224 1225 sx_xlock(&kld_sx); 1226 lf = linker_find_file_by_id(fileid); 1227 if (lf == NULL) { 1228 sx_xunlock(&kld_sx); 1229 return (ENOENT); 1230 } 1231 1232 /* Version 1 fields: */ 1233 namelen = strlen(lf->filename) + 1; 1234 if (namelen > MAXPATHLEN) 1235 namelen = MAXPATHLEN; 1236 bcopy(lf->filename, &stat->name[0], namelen); 1237 stat->refs = lf->refs; 1238 stat->id = lf->id; 1239 stat->address = lf->address; 1240 stat->size = lf->size; 1241 /* Version 2 fields: */ 1242 namelen = strlen(lf->pathname) + 1; 1243 if (namelen > MAXPATHLEN) 1244 namelen = MAXPATHLEN; 1245 bcopy(lf->pathname, &stat->pathname[0], namelen); 1246 sx_xunlock(&kld_sx); 1247 1248 td->td_retval[0] = 0; 1249 return (0); 1250 } 1251 1252 int 1253 sys_kldfirstmod(struct thread *td, struct kldfirstmod_args *uap) 1254 { 1255 linker_file_t lf; 1256 module_t mp; 1257 int error = 0; 1258 1259 #ifdef MAC 1260 error = mac_kld_check_stat(td->td_ucred); 1261 if (error) 1262 return (error); 1263 #endif 1264 1265 sx_xlock(&kld_sx); 1266 lf = linker_find_file_by_id(uap->fileid); 1267 if (lf) { 1268 MOD_SLOCK; 1269 mp = TAILQ_FIRST(&lf->modules); 1270 if (mp != NULL) 1271 td->td_retval[0] = module_getid(mp); 1272 else 1273 td->td_retval[0] = 0; 1274 MOD_SUNLOCK; 1275 } else 1276 error = ENOENT; 1277 sx_xunlock(&kld_sx); 1278 return (error); 1279 } 1280 1281 int 1282 sys_kldsym(struct thread *td, struct kldsym_args *uap) 1283 { 1284 char *symstr = NULL; 1285 c_linker_sym_t sym; 1286 linker_symval_t symval; 1287 linker_file_t lf; 1288 struct kld_sym_lookup lookup; 1289 int error = 0; 1290 1291 #ifdef MAC 1292 error = mac_kld_check_stat(td->td_ucred); 1293 if (error) 1294 return (error); 1295 #endif 1296 1297 if ((error = copyin(uap->data, &lookup, sizeof(lookup))) != 0) 1298 return (error); 1299 if (lookup.version != sizeof(lookup) || 1300 uap->cmd != KLDSYM_LOOKUP) 1301 return (EINVAL); 1302 symstr = malloc(MAXPATHLEN, M_TEMP, M_WAITOK); 1303 if ((error = copyinstr(lookup.symname, symstr, MAXPATHLEN, NULL)) != 0) 1304 goto out; 1305 sx_xlock(&kld_sx); 1306 if (uap->fileid != 0) { 1307 lf = linker_find_file_by_id(uap->fileid); 1308 if (lf == NULL) 1309 error = ENOENT; 1310 else if (LINKER_LOOKUP_SYMBOL(lf, symstr, &sym) == 0 && 1311 LINKER_SYMBOL_VALUES(lf, sym, &symval) == 0) { 1312 lookup.symvalue = (uintptr_t) symval.value; 1313 lookup.symsize = symval.size; 1314 error = copyout(&lookup, uap->data, sizeof(lookup)); 1315 } else 1316 error = ENOENT; 1317 } else { 1318 TAILQ_FOREACH(lf, &linker_files, link) { 1319 if (LINKER_LOOKUP_SYMBOL(lf, symstr, &sym) == 0 && 1320 LINKER_SYMBOL_VALUES(lf, sym, &symval) == 0) { 1321 lookup.symvalue = (uintptr_t)symval.value; 1322 lookup.symsize = symval.size; 1323 error = copyout(&lookup, uap->data, 1324 sizeof(lookup)); 1325 break; 1326 } 1327 } 1328 if (lf == NULL) 1329 error = ENOENT; 1330 } 1331 sx_xunlock(&kld_sx); 1332 out: 1333 free(symstr, M_TEMP); 1334 return (error); 1335 } 1336 1337 /* 1338 * Preloaded module support 1339 */ 1340 1341 static modlist_t 1342 modlist_lookup(const char *name, int ver) 1343 { 1344 modlist_t mod; 1345 1346 TAILQ_FOREACH(mod, &found_modules, link) { 1347 if (strcmp(mod->name, name) == 0 && 1348 (ver == 0 || mod->version == ver)) 1349 return (mod); 1350 } 1351 return (NULL); 1352 } 1353 1354 static modlist_t 1355 modlist_lookup2(const char *name, struct mod_depend *verinfo) 1356 { 1357 modlist_t mod, bestmod; 1358 int ver; 1359 1360 if (verinfo == NULL) 1361 return (modlist_lookup(name, 0)); 1362 bestmod = NULL; 1363 TAILQ_FOREACH(mod, &found_modules, link) { 1364 if (strcmp(mod->name, name) != 0) 1365 continue; 1366 ver = mod->version; 1367 if (ver == verinfo->md_ver_preferred) 1368 return (mod); 1369 if (ver >= verinfo->md_ver_minimum && 1370 ver <= verinfo->md_ver_maximum && 1371 (bestmod == NULL || ver > bestmod->version)) 1372 bestmod = mod; 1373 } 1374 return (bestmod); 1375 } 1376 1377 static modlist_t 1378 modlist_newmodule(const char *modname, int version, linker_file_t container) 1379 { 1380 modlist_t mod; 1381 1382 mod = malloc(sizeof(struct modlist), M_LINKER, M_NOWAIT | M_ZERO); 1383 if (mod == NULL) 1384 panic("no memory for module list"); 1385 mod->container = container; 1386 mod->name = modname; 1387 mod->version = version; 1388 TAILQ_INSERT_TAIL(&found_modules, mod, link); 1389 return (mod); 1390 } 1391 1392 static void 1393 linker_addmodules(linker_file_t lf, struct mod_metadata **start, 1394 struct mod_metadata **stop, int preload) 1395 { 1396 struct mod_metadata *mp, **mdp; 1397 const char *modname; 1398 int ver; 1399 1400 for (mdp = start; mdp < stop; mdp++) { 1401 mp = *mdp; 1402 if (mp->md_type != MDT_VERSION) 1403 continue; 1404 modname = mp->md_cval; 1405 ver = ((struct mod_version *)mp->md_data)->mv_version; 1406 if (modlist_lookup(modname, ver) != NULL) { 1407 printf("module %s already present!\n", modname); 1408 /* XXX what can we do? this is a build error. :-( */ 1409 continue; 1410 } 1411 modlist_newmodule(modname, ver, lf); 1412 } 1413 } 1414 1415 static void 1416 linker_preload(void *arg) 1417 { 1418 caddr_t modptr; 1419 const char *modname, *nmodname; 1420 char *modtype; 1421 linker_file_t lf, nlf; 1422 linker_class_t lc; 1423 int error; 1424 linker_file_list_t loaded_files; 1425 linker_file_list_t depended_files; 1426 struct mod_metadata *mp, *nmp; 1427 struct mod_metadata **start, **stop, **mdp, **nmdp; 1428 struct mod_depend *verinfo; 1429 int nver; 1430 int resolves; 1431 modlist_t mod; 1432 struct sysinit **si_start, **si_stop; 1433 1434 TAILQ_INIT(&loaded_files); 1435 TAILQ_INIT(&depended_files); 1436 TAILQ_INIT(&found_modules); 1437 error = 0; 1438 1439 modptr = NULL; 1440 sx_xlock(&kld_sx); 1441 while ((modptr = preload_search_next_name(modptr)) != NULL) { 1442 modname = (char *)preload_search_info(modptr, MODINFO_NAME); 1443 modtype = (char *)preload_search_info(modptr, MODINFO_TYPE); 1444 if (modname == NULL) { 1445 printf("Preloaded module at %p does not have a" 1446 " name!\n", modptr); 1447 continue; 1448 } 1449 if (modtype == NULL) { 1450 printf("Preloaded module at %p does not have a type!\n", 1451 modptr); 1452 continue; 1453 } 1454 if (bootverbose) 1455 printf("Preloaded %s \"%s\" at %p.\n", modtype, modname, 1456 modptr); 1457 lf = NULL; 1458 TAILQ_FOREACH(lc, &classes, link) { 1459 error = LINKER_LINK_PRELOAD(lc, modname, &lf); 1460 if (!error) 1461 break; 1462 lf = NULL; 1463 } 1464 if (lf) 1465 TAILQ_INSERT_TAIL(&loaded_files, lf, loaded); 1466 } 1467 1468 /* 1469 * First get a list of stuff in the kernel. 1470 */ 1471 if (linker_file_lookup_set(linker_kernel_file, MDT_SETNAME, &start, 1472 &stop, NULL) == 0) 1473 linker_addmodules(linker_kernel_file, start, stop, 1); 1474 1475 /* 1476 * This is a once-off kinky bubble sort to resolve relocation 1477 * dependency requirements. 1478 */ 1479 restart: 1480 TAILQ_FOREACH(lf, &loaded_files, loaded) { 1481 error = linker_file_lookup_set(lf, MDT_SETNAME, &start, 1482 &stop, NULL); 1483 /* 1484 * First, look to see if we would successfully link with this 1485 * stuff. 1486 */ 1487 resolves = 1; /* unless we know otherwise */ 1488 if (!error) { 1489 for (mdp = start; mdp < stop; mdp++) { 1490 mp = *mdp; 1491 if (mp->md_type != MDT_DEPEND) 1492 continue; 1493 modname = mp->md_cval; 1494 verinfo = mp->md_data; 1495 for (nmdp = start; nmdp < stop; nmdp++) { 1496 nmp = *nmdp; 1497 if (nmp->md_type != MDT_VERSION) 1498 continue; 1499 nmodname = nmp->md_cval; 1500 if (strcmp(modname, nmodname) == 0) 1501 break; 1502 } 1503 if (nmdp < stop) /* it's a self reference */ 1504 continue; 1505 1506 /* 1507 * ok, the module isn't here yet, we 1508 * are not finished 1509 */ 1510 if (modlist_lookup2(modname, verinfo) == NULL) 1511 resolves = 0; 1512 } 1513 } 1514 /* 1515 * OK, if we found our modules, we can link. So, "provide" 1516 * the modules inside and add it to the end of the link order 1517 * list. 1518 */ 1519 if (resolves) { 1520 if (!error) { 1521 for (mdp = start; mdp < stop; mdp++) { 1522 mp = *mdp; 1523 if (mp->md_type != MDT_VERSION) 1524 continue; 1525 modname = mp->md_cval; 1526 nver = ((struct mod_version *) 1527 mp->md_data)->mv_version; 1528 if (modlist_lookup(modname, 1529 nver) != NULL) { 1530 printf("module %s already" 1531 " present!\n", modname); 1532 TAILQ_REMOVE(&loaded_files, 1533 lf, loaded); 1534 linker_file_unload(lf, 1535 LINKER_UNLOAD_FORCE); 1536 /* we changed tailq next ptr */ 1537 goto restart; 1538 } 1539 modlist_newmodule(modname, nver, lf); 1540 } 1541 } 1542 TAILQ_REMOVE(&loaded_files, lf, loaded); 1543 TAILQ_INSERT_TAIL(&depended_files, lf, loaded); 1544 /* 1545 * Since we provided modules, we need to restart the 1546 * sort so that the previous files that depend on us 1547 * have a chance. Also, we've busted the tailq next 1548 * pointer with the REMOVE. 1549 */ 1550 goto restart; 1551 } 1552 } 1553 1554 /* 1555 * At this point, we check to see what could not be resolved.. 1556 */ 1557 while ((lf = TAILQ_FIRST(&loaded_files)) != NULL) { 1558 TAILQ_REMOVE(&loaded_files, lf, loaded); 1559 printf("KLD file %s is missing dependencies\n", lf->filename); 1560 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 1561 } 1562 1563 /* 1564 * We made it. Finish off the linking in the order we determined. 1565 */ 1566 TAILQ_FOREACH_SAFE(lf, &depended_files, loaded, nlf) { 1567 if (linker_kernel_file) { 1568 linker_kernel_file->refs++; 1569 error = linker_file_add_dependency(lf, 1570 linker_kernel_file); 1571 if (error) 1572 panic("cannot add dependency"); 1573 } 1574 lf->userrefs++; /* so we can (try to) kldunload it */ 1575 error = linker_file_lookup_set(lf, MDT_SETNAME, &start, 1576 &stop, NULL); 1577 if (!error) { 1578 for (mdp = start; mdp < stop; mdp++) { 1579 mp = *mdp; 1580 if (mp->md_type != MDT_DEPEND) 1581 continue; 1582 modname = mp->md_cval; 1583 verinfo = mp->md_data; 1584 mod = modlist_lookup2(modname, verinfo); 1585 if (mod == NULL) { 1586 printf("KLD file %s - cannot find " 1587 "dependency \"%s\"\n", 1588 lf->filename, modname); 1589 goto fail; 1590 } 1591 /* Don't count self-dependencies */ 1592 if (lf == mod->container) 1593 continue; 1594 mod->container->refs++; 1595 error = linker_file_add_dependency(lf, 1596 mod->container); 1597 if (error) 1598 panic("cannot add dependency"); 1599 } 1600 } 1601 /* 1602 * Now do relocation etc using the symbol search paths 1603 * established by the dependencies 1604 */ 1605 error = LINKER_LINK_PRELOAD_FINISH(lf); 1606 if (error) { 1607 printf("KLD file %s - could not finalize loading\n", 1608 lf->filename); 1609 goto fail; 1610 } 1611 linker_file_register_modules(lf); 1612 if (linker_file_lookup_set(lf, "sysinit_set", &si_start, 1613 &si_stop, NULL) == 0) 1614 sysinit_add(si_start, si_stop); 1615 linker_file_register_sysctls(lf); 1616 lf->flags |= LINKER_FILE_LINKED; 1617 continue; 1618 fail: 1619 TAILQ_REMOVE(&depended_files, lf, loaded); 1620 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 1621 } 1622 sx_xunlock(&kld_sx); 1623 /* woohoo! we made it! */ 1624 } 1625 1626 SYSINIT(preload, SI_SUB_KLD, SI_ORDER_MIDDLE, linker_preload, 0); 1627 1628 /* 1629 * Search for a not-loaded module by name. 1630 * 1631 * Modules may be found in the following locations: 1632 * 1633 * - preloaded (result is just the module name) - on disk (result is full path 1634 * to module) 1635 * 1636 * If the module name is qualified in any way (contains path, etc.) the we 1637 * simply return a copy of it. 1638 * 1639 * The search path can be manipulated via sysctl. Note that we use the ';' 1640 * character as a separator to be consistent with the bootloader. 1641 */ 1642 1643 static char linker_hintfile[] = "linker.hints"; 1644 static char linker_path[MAXPATHLEN] = "/boot/kernel;/boot/modules"; 1645 1646 SYSCTL_STRING(_kern, OID_AUTO, module_path, CTLFLAG_RW, linker_path, 1647 sizeof(linker_path), "module load search path"); 1648 1649 TUNABLE_STR("module_path", linker_path, sizeof(linker_path)); 1650 1651 static char *linker_ext_list[] = { 1652 "", 1653 ".ko", 1654 NULL 1655 }; 1656 1657 /* 1658 * Check if file actually exists either with or without extension listed in 1659 * the linker_ext_list. (probably should be generic for the rest of the 1660 * kernel) 1661 */ 1662 static char * 1663 linker_lookup_file(const char *path, int pathlen, const char *name, 1664 int namelen, struct vattr *vap) 1665 { 1666 struct nameidata nd; 1667 struct thread *td = curthread; /* XXX */ 1668 char *result, **cpp, *sep; 1669 int error, len, extlen, reclen, flags; 1670 enum vtype type; 1671 1672 extlen = 0; 1673 for (cpp = linker_ext_list; *cpp; cpp++) { 1674 len = strlen(*cpp); 1675 if (len > extlen) 1676 extlen = len; 1677 } 1678 extlen++; /* trailing '\0' */ 1679 sep = (path[pathlen - 1] != '/') ? "/" : ""; 1680 1681 reclen = pathlen + strlen(sep) + namelen + extlen + 1; 1682 result = malloc(reclen, M_LINKER, M_WAITOK); 1683 for (cpp = linker_ext_list; *cpp; cpp++) { 1684 snprintf(result, reclen, "%.*s%s%.*s%s", pathlen, path, sep, 1685 namelen, name, *cpp); 1686 /* 1687 * Attempt to open the file, and return the path if 1688 * we succeed and it's a regular file. 1689 */ 1690 NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, result, td); 1691 flags = FREAD; 1692 error = vn_open(&nd, &flags, 0, NULL); 1693 if (error == 0) { 1694 NDFREE(&nd, NDF_ONLY_PNBUF); 1695 type = nd.ni_vp->v_type; 1696 if (vap) 1697 VOP_GETATTR(nd.ni_vp, vap, td->td_ucred); 1698 VOP_UNLOCK(nd.ni_vp, 0); 1699 vn_close(nd.ni_vp, FREAD, td->td_ucred, td); 1700 if (type == VREG) 1701 return (result); 1702 } 1703 } 1704 free(result, M_LINKER); 1705 return (NULL); 1706 } 1707 1708 #define INT_ALIGN(base, ptr) ptr = \ 1709 (base) + (((ptr) - (base) + sizeof(int) - 1) & ~(sizeof(int) - 1)) 1710 1711 /* 1712 * Lookup KLD which contains requested module in the "linker.hints" file. If 1713 * version specification is available, then try to find the best KLD. 1714 * Otherwise just find the latest one. 1715 */ 1716 static char * 1717 linker_hints_lookup(const char *path, int pathlen, const char *modname, 1718 int modnamelen, struct mod_depend *verinfo) 1719 { 1720 struct thread *td = curthread; /* XXX */ 1721 struct ucred *cred = td ? td->td_ucred : NULL; 1722 struct nameidata nd; 1723 struct vattr vattr, mattr; 1724 u_char *hints = NULL; 1725 u_char *cp, *recptr, *bufend, *result, *best, *pathbuf, *sep; 1726 int error, ival, bestver, *intp, found, flags, clen, blen; 1727 ssize_t reclen; 1728 1729 result = NULL; 1730 bestver = found = 0; 1731 1732 sep = (path[pathlen - 1] != '/') ? "/" : ""; 1733 reclen = imax(modnamelen, strlen(linker_hintfile)) + pathlen + 1734 strlen(sep) + 1; 1735 pathbuf = malloc(reclen, M_LINKER, M_WAITOK); 1736 snprintf(pathbuf, reclen, "%.*s%s%s", pathlen, path, sep, 1737 linker_hintfile); 1738 1739 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, pathbuf, td); 1740 flags = FREAD; 1741 error = vn_open(&nd, &flags, 0, NULL); 1742 if (error) 1743 goto bad; 1744 NDFREE(&nd, NDF_ONLY_PNBUF); 1745 if (nd.ni_vp->v_type != VREG) 1746 goto bad; 1747 best = cp = NULL; 1748 error = VOP_GETATTR(nd.ni_vp, &vattr, cred); 1749 if (error) 1750 goto bad; 1751 /* 1752 * XXX: we need to limit this number to some reasonable value 1753 */ 1754 if (vattr.va_size > 100 * 1024) { 1755 printf("hints file too large %ld\n", (long)vattr.va_size); 1756 goto bad; 1757 } 1758 hints = malloc(vattr.va_size, M_TEMP, M_WAITOK); 1759 if (hints == NULL) 1760 goto bad; 1761 error = vn_rdwr(UIO_READ, nd.ni_vp, (caddr_t)hints, vattr.va_size, 0, 1762 UIO_SYSSPACE, IO_NODELOCKED, cred, NOCRED, &reclen, td); 1763 if (error) 1764 goto bad; 1765 VOP_UNLOCK(nd.ni_vp, 0); 1766 vn_close(nd.ni_vp, FREAD, cred, td); 1767 nd.ni_vp = NULL; 1768 if (reclen != 0) { 1769 printf("can't read %zd\n", reclen); 1770 goto bad; 1771 } 1772 intp = (int *)hints; 1773 ival = *intp++; 1774 if (ival != LINKER_HINTS_VERSION) { 1775 printf("hints file version mismatch %d\n", ival); 1776 goto bad; 1777 } 1778 bufend = hints + vattr.va_size; 1779 recptr = (u_char *)intp; 1780 clen = blen = 0; 1781 while (recptr < bufend && !found) { 1782 intp = (int *)recptr; 1783 reclen = *intp++; 1784 ival = *intp++; 1785 cp = (char *)intp; 1786 switch (ival) { 1787 case MDT_VERSION: 1788 clen = *cp++; 1789 if (clen != modnamelen || bcmp(cp, modname, clen) != 0) 1790 break; 1791 cp += clen; 1792 INT_ALIGN(hints, cp); 1793 ival = *(int *)cp; 1794 cp += sizeof(int); 1795 clen = *cp++; 1796 if (verinfo == NULL || 1797 ival == verinfo->md_ver_preferred) { 1798 found = 1; 1799 break; 1800 } 1801 if (ival >= verinfo->md_ver_minimum && 1802 ival <= verinfo->md_ver_maximum && 1803 ival > bestver) { 1804 bestver = ival; 1805 best = cp; 1806 blen = clen; 1807 } 1808 break; 1809 default: 1810 break; 1811 } 1812 recptr += reclen + sizeof(int); 1813 } 1814 /* 1815 * Finally check if KLD is in the place 1816 */ 1817 if (found) 1818 result = linker_lookup_file(path, pathlen, cp, clen, &mattr); 1819 else if (best) 1820 result = linker_lookup_file(path, pathlen, best, blen, &mattr); 1821 1822 /* 1823 * KLD is newer than hints file. What we should do now? 1824 */ 1825 if (result && timespeccmp(&mattr.va_mtime, &vattr.va_mtime, >)) 1826 printf("warning: KLD '%s' is newer than the linker.hints" 1827 " file\n", result); 1828 bad: 1829 free(pathbuf, M_LINKER); 1830 if (hints) 1831 free(hints, M_TEMP); 1832 if (nd.ni_vp != NULL) { 1833 VOP_UNLOCK(nd.ni_vp, 0); 1834 vn_close(nd.ni_vp, FREAD, cred, td); 1835 } 1836 /* 1837 * If nothing found or hints is absent - fallback to the old 1838 * way by using "kldname[.ko]" as module name. 1839 */ 1840 if (!found && !bestver && result == NULL) 1841 result = linker_lookup_file(path, pathlen, modname, 1842 modnamelen, NULL); 1843 return (result); 1844 } 1845 1846 /* 1847 * Lookup KLD which contains requested module in the all directories. 1848 */ 1849 static char * 1850 linker_search_module(const char *modname, int modnamelen, 1851 struct mod_depend *verinfo) 1852 { 1853 char *cp, *ep, *result; 1854 1855 /* 1856 * traverse the linker path 1857 */ 1858 for (cp = linker_path; *cp; cp = ep + 1) { 1859 /* find the end of this component */ 1860 for (ep = cp; (*ep != 0) && (*ep != ';'); ep++); 1861 result = linker_hints_lookup(cp, ep - cp, modname, 1862 modnamelen, verinfo); 1863 if (result != NULL) 1864 return (result); 1865 if (*ep == 0) 1866 break; 1867 } 1868 return (NULL); 1869 } 1870 1871 /* 1872 * Search for module in all directories listed in the linker_path. 1873 */ 1874 static char * 1875 linker_search_kld(const char *name) 1876 { 1877 char *cp, *ep, *result; 1878 int len; 1879 1880 /* qualified at all? */ 1881 if (strchr(name, '/')) 1882 return (strdup(name, M_LINKER)); 1883 1884 /* traverse the linker path */ 1885 len = strlen(name); 1886 for (ep = linker_path; *ep; ep++) { 1887 cp = ep; 1888 /* find the end of this component */ 1889 for (; *ep != 0 && *ep != ';'; ep++); 1890 result = linker_lookup_file(cp, ep - cp, name, len, NULL); 1891 if (result != NULL) 1892 return (result); 1893 } 1894 return (NULL); 1895 } 1896 1897 static const char * 1898 linker_basename(const char *path) 1899 { 1900 const char *filename; 1901 1902 filename = strrchr(path, '/'); 1903 if (filename == NULL) 1904 return path; 1905 if (filename[1]) 1906 filename++; 1907 return (filename); 1908 } 1909 1910 #ifdef HWPMC_HOOKS 1911 /* 1912 * Inform hwpmc about the set of kernel modules currently loaded. 1913 */ 1914 void * 1915 linker_hwpmc_list_objects(void) 1916 { 1917 linker_file_t lf; 1918 struct pmckern_map_in *kobase; 1919 int i, nmappings; 1920 1921 nmappings = 0; 1922 sx_slock(&kld_sx); 1923 TAILQ_FOREACH(lf, &linker_files, link) 1924 nmappings++; 1925 1926 /* Allocate nmappings + 1 entries. */ 1927 kobase = malloc((nmappings + 1) * sizeof(struct pmckern_map_in), 1928 M_LINKER, M_WAITOK | M_ZERO); 1929 i = 0; 1930 TAILQ_FOREACH(lf, &linker_files, link) { 1931 1932 /* Save the info for this linker file. */ 1933 kobase[i].pm_file = lf->filename; 1934 kobase[i].pm_address = (uintptr_t)lf->address; 1935 i++; 1936 } 1937 sx_sunlock(&kld_sx); 1938 1939 KASSERT(i > 0, ("linker_hpwmc_list_objects: no kernel objects?")); 1940 1941 /* The last entry of the malloced area comprises of all zeros. */ 1942 KASSERT(kobase[i].pm_file == NULL, 1943 ("linker_hwpmc_list_objects: last object not NULL")); 1944 1945 return ((void *)kobase); 1946 } 1947 #endif 1948 1949 /* 1950 * Find a file which contains given module and load it, if "parent" is not 1951 * NULL, register a reference to it. 1952 */ 1953 static int 1954 linker_load_module(const char *kldname, const char *modname, 1955 struct linker_file *parent, struct mod_depend *verinfo, 1956 struct linker_file **lfpp) 1957 { 1958 linker_file_t lfdep; 1959 const char *filename; 1960 char *pathname; 1961 int error; 1962 1963 sx_assert(&kld_sx, SA_XLOCKED); 1964 if (modname == NULL) { 1965 /* 1966 * We have to load KLD 1967 */ 1968 KASSERT(verinfo == NULL, ("linker_load_module: verinfo" 1969 " is not NULL")); 1970 pathname = linker_search_kld(kldname); 1971 } else { 1972 if (modlist_lookup2(modname, verinfo) != NULL) 1973 return (EEXIST); 1974 if (kldname != NULL) 1975 pathname = strdup(kldname, M_LINKER); 1976 else if (rootvnode == NULL) 1977 pathname = NULL; 1978 else 1979 /* 1980 * Need to find a KLD with required module 1981 */ 1982 pathname = linker_search_module(modname, 1983 strlen(modname), verinfo); 1984 } 1985 if (pathname == NULL) 1986 return (ENOENT); 1987 1988 /* 1989 * Can't load more than one file with the same basename XXX: 1990 * Actually it should be possible to have multiple KLDs with 1991 * the same basename but different path because they can 1992 * provide different versions of the same modules. 1993 */ 1994 filename = linker_basename(pathname); 1995 if (linker_find_file_by_name(filename)) 1996 error = EEXIST; 1997 else do { 1998 error = linker_load_file(pathname, &lfdep); 1999 if (error) 2000 break; 2001 if (modname && verinfo && 2002 modlist_lookup2(modname, verinfo) == NULL) { 2003 linker_file_unload(lfdep, LINKER_UNLOAD_FORCE); 2004 error = ENOENT; 2005 break; 2006 } 2007 if (parent) { 2008 error = linker_file_add_dependency(parent, lfdep); 2009 if (error) 2010 break; 2011 } 2012 if (lfpp) 2013 *lfpp = lfdep; 2014 } while (0); 2015 free(pathname, M_LINKER); 2016 return (error); 2017 } 2018 2019 /* 2020 * This routine is responsible for finding dependencies of userland initiated 2021 * kldload(2)'s of files. 2022 */ 2023 int 2024 linker_load_dependencies(linker_file_t lf) 2025 { 2026 linker_file_t lfdep; 2027 struct mod_metadata **start, **stop, **mdp, **nmdp; 2028 struct mod_metadata *mp, *nmp; 2029 struct mod_depend *verinfo; 2030 modlist_t mod; 2031 const char *modname, *nmodname; 2032 int ver, error = 0, count; 2033 2034 /* 2035 * All files are dependant on /kernel. 2036 */ 2037 sx_assert(&kld_sx, SA_XLOCKED); 2038 if (linker_kernel_file) { 2039 linker_kernel_file->refs++; 2040 error = linker_file_add_dependency(lf, linker_kernel_file); 2041 if (error) 2042 return (error); 2043 } 2044 if (linker_file_lookup_set(lf, MDT_SETNAME, &start, &stop, 2045 &count) != 0) 2046 return (0); 2047 for (mdp = start; mdp < stop; mdp++) { 2048 mp = *mdp; 2049 if (mp->md_type != MDT_VERSION) 2050 continue; 2051 modname = mp->md_cval; 2052 ver = ((struct mod_version *)mp->md_data)->mv_version; 2053 mod = modlist_lookup(modname, ver); 2054 if (mod != NULL) { 2055 printf("interface %s.%d already present in the KLD" 2056 " '%s'!\n", modname, ver, 2057 mod->container->filename); 2058 return (EEXIST); 2059 } 2060 } 2061 2062 for (mdp = start; mdp < stop; mdp++) { 2063 mp = *mdp; 2064 if (mp->md_type != MDT_DEPEND) 2065 continue; 2066 modname = mp->md_cval; 2067 verinfo = mp->md_data; 2068 nmodname = NULL; 2069 for (nmdp = start; nmdp < stop; nmdp++) { 2070 nmp = *nmdp; 2071 if (nmp->md_type != MDT_VERSION) 2072 continue; 2073 nmodname = nmp->md_cval; 2074 if (strcmp(modname, nmodname) == 0) 2075 break; 2076 } 2077 if (nmdp < stop)/* early exit, it's a self reference */ 2078 continue; 2079 mod = modlist_lookup2(modname, verinfo); 2080 if (mod) { /* woohoo, it's loaded already */ 2081 lfdep = mod->container; 2082 lfdep->refs++; 2083 error = linker_file_add_dependency(lf, lfdep); 2084 if (error) 2085 break; 2086 continue; 2087 } 2088 error = linker_load_module(NULL, modname, lf, verinfo, NULL); 2089 if (error) { 2090 printf("KLD %s: depends on %s - not available or" 2091 " version mismatch\n", lf->filename, modname); 2092 break; 2093 } 2094 } 2095 2096 if (error) 2097 return (error); 2098 linker_addmodules(lf, start, stop, 0); 2099 return (error); 2100 } 2101 2102 static int 2103 sysctl_kern_function_list_iterate(const char *name, void *opaque) 2104 { 2105 struct sysctl_req *req; 2106 2107 req = opaque; 2108 return (SYSCTL_OUT(req, name, strlen(name) + 1)); 2109 } 2110 2111 /* 2112 * Export a nul-separated, double-nul-terminated list of all function names 2113 * in the kernel. 2114 */ 2115 static int 2116 sysctl_kern_function_list(SYSCTL_HANDLER_ARGS) 2117 { 2118 linker_file_t lf; 2119 int error; 2120 2121 #ifdef MAC 2122 error = mac_kld_check_stat(req->td->td_ucred); 2123 if (error) 2124 return (error); 2125 #endif 2126 error = sysctl_wire_old_buffer(req, 0); 2127 if (error != 0) 2128 return (error); 2129 sx_xlock(&kld_sx); 2130 TAILQ_FOREACH(lf, &linker_files, link) { 2131 error = LINKER_EACH_FUNCTION_NAME(lf, 2132 sysctl_kern_function_list_iterate, req); 2133 if (error) { 2134 sx_xunlock(&kld_sx); 2135 return (error); 2136 } 2137 } 2138 sx_xunlock(&kld_sx); 2139 return (SYSCTL_OUT(req, "", 1)); 2140 } 2141 2142 SYSCTL_PROC(_kern, OID_AUTO, function_list, CTLTYPE_OPAQUE | CTLFLAG_RD, 2143 NULL, 0, sysctl_kern_function_list, "", "kernel function list"); 2144