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