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