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, 367 0); 368 369 static int 370 linker_load_file(const char *filename, linker_file_t *result) 371 { 372 linker_class_t lc; 373 linker_file_t lf; 374 int foundfile, error; 375 376 /* Refuse to load modules if securelevel raised */ 377 if (securelevel > 0) 378 return (EPERM); 379 380 KLD_LOCK_ASSERT(); 381 lf = linker_find_file_by_name(filename); 382 if (lf) { 383 KLD_DPF(FILE, ("linker_load_file: file %s is already loaded," 384 " incrementing refs\n", filename)); 385 *result = lf; 386 lf->refs++; 387 return (0); 388 } 389 foundfile = 0; 390 error = 0; 391 392 /* 393 * We do not need to protect (lock) classes here because there is 394 * no class registration past startup (SI_SUB_KLD, SI_ORDER_ANY) 395 * and there is no class deregistration mechanism at this time. 396 */ 397 TAILQ_FOREACH(lc, &classes, link) { 398 KLD_DPF(FILE, ("linker_load_file: trying to load %s\n", 399 filename)); 400 error = LINKER_LOAD_FILE(lc, filename, &lf); 401 /* 402 * If we got something other than ENOENT, then it exists but 403 * we cannot load it for some other reason. 404 */ 405 if (error != ENOENT) 406 foundfile = 1; 407 if (lf) { 408 error = linker_file_register_modules(lf); 409 if (error == EEXIST) { 410 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 411 return (error); 412 } 413 KLD_UNLOCK(); 414 linker_file_register_sysctls(lf); 415 linker_file_sysinit(lf); 416 KLD_LOCK(); 417 lf->flags |= LINKER_FILE_LINKED; 418 *result = lf; 419 return (0); 420 } 421 } 422 /* 423 * Less than ideal, but tells the user whether it failed to load or 424 * the module was not found. 425 */ 426 if (foundfile) { 427 /* 428 * Format not recognized or otherwise unloadable. 429 * When loading a module that is statically built into 430 * the kernel EEXIST percolates back up as the return 431 * value. Preserve this so that apps like sysinstall 432 * can recognize this special case and not post bogus 433 * dialog boxes. 434 */ 435 if (error != EEXIST) 436 error = ENOEXEC; 437 } else 438 error = ENOENT; /* Nothing found */ 439 return (error); 440 } 441 442 int 443 linker_reference_module(const char *modname, struct mod_depend *verinfo, 444 linker_file_t *result) 445 { 446 modlist_t mod; 447 int error; 448 449 KLD_LOCK(); 450 if ((mod = modlist_lookup2(modname, verinfo)) != NULL) { 451 *result = mod->container; 452 (*result)->refs++; 453 KLD_UNLOCK(); 454 return (0); 455 } 456 457 error = linker_load_module(NULL, modname, NULL, verinfo, result); 458 KLD_UNLOCK(); 459 return (error); 460 } 461 462 int 463 linker_release_module(const char *modname, struct mod_depend *verinfo, 464 linker_file_t lf) 465 { 466 modlist_t mod; 467 int error; 468 469 KLD_LOCK(); 470 if (lf == NULL) { 471 KASSERT(modname != NULL, 472 ("linker_release_module: no file or name")); 473 mod = modlist_lookup2(modname, verinfo); 474 if (mod == NULL) { 475 KLD_UNLOCK(); 476 return (ESRCH); 477 } 478 lf = mod->container; 479 } else 480 KASSERT(modname == NULL && verinfo == NULL, 481 ("linker_release_module: both file and name")); 482 error = linker_file_unload(lf, LINKER_UNLOAD_NORMAL); 483 KLD_UNLOCK(); 484 return (error); 485 } 486 487 static linker_file_t 488 linker_find_file_by_name(const char *filename) 489 { 490 linker_file_t lf; 491 char *koname; 492 493 koname = malloc(strlen(filename) + 4, M_LINKER, M_WAITOK); 494 sprintf(koname, "%s.ko", filename); 495 496 KLD_LOCK_ASSERT(); 497 TAILQ_FOREACH(lf, &linker_files, link) { 498 if (strcmp(lf->filename, koname) == 0) 499 break; 500 if (strcmp(lf->filename, filename) == 0) 501 break; 502 } 503 free(koname, M_LINKER); 504 return (lf); 505 } 506 507 static linker_file_t 508 linker_find_file_by_id(int fileid) 509 { 510 linker_file_t lf; 511 512 KLD_LOCK_ASSERT(); 513 TAILQ_FOREACH(lf, &linker_files, link) 514 if (lf->id == fileid && lf->flags & LINKER_FILE_LINKED) 515 break; 516 return (lf); 517 } 518 519 int 520 linker_file_foreach(linker_predicate_t *predicate, void *context) 521 { 522 linker_file_t lf; 523 int retval = 0; 524 525 KLD_LOCK(); 526 TAILQ_FOREACH(lf, &linker_files, link) { 527 retval = predicate(lf, context); 528 if (retval != 0) 529 break; 530 } 531 KLD_UNLOCK(); 532 return (retval); 533 } 534 535 linker_file_t 536 linker_make_file(const char *pathname, linker_class_t lc) 537 { 538 linker_file_t lf; 539 const char *filename; 540 541 KLD_LOCK_ASSERT(); 542 filename = linker_basename(pathname); 543 544 KLD_DPF(FILE, ("linker_make_file: new file, filename='%s' for pathname='%s'\n", filename, pathname)); 545 lf = (linker_file_t)kobj_create((kobj_class_t)lc, M_LINKER, M_WAITOK); 546 if (lf == NULL) 547 return (NULL); 548 lf->refs = 1; 549 lf->userrefs = 0; 550 lf->flags = 0; 551 lf->filename = linker_strdup(filename); 552 lf->pathname = linker_strdup(pathname); 553 LINKER_GET_NEXT_FILE_ID(lf->id); 554 lf->ndeps = 0; 555 lf->deps = NULL; 556 lf->loadcnt = ++loadcnt; 557 lf->sdt_probes = NULL; 558 lf->sdt_nprobes = 0; 559 STAILQ_INIT(&lf->common); 560 TAILQ_INIT(&lf->modules); 561 TAILQ_INSERT_TAIL(&linker_files, lf, link); 562 return (lf); 563 } 564 565 int 566 linker_file_unload(linker_file_t file, int flags) 567 { 568 module_t mod, next; 569 modlist_t ml, nextml; 570 struct common_symbol *cp; 571 int error, i; 572 573 /* Refuse to unload modules if securelevel raised. */ 574 if (securelevel > 0) 575 return (EPERM); 576 577 KLD_LOCK_ASSERT(); 578 KLD_DPF(FILE, ("linker_file_unload: lf->refs=%d\n", file->refs)); 579 580 /* Easy case of just dropping a reference. */ 581 if (file->refs > 1) { 582 file->refs--; 583 return (0); 584 } 585 586 KLD_DPF(FILE, ("linker_file_unload: file is unloading," 587 " informing modules\n")); 588 589 /* 590 * Inform any modules associated with this file. 591 */ 592 MOD_XLOCK; 593 for (mod = TAILQ_FIRST(&file->modules); mod; mod = next) { 594 next = module_getfnext(mod); 595 MOD_XUNLOCK; 596 597 /* 598 * Give the module a chance to veto the unload. 599 */ 600 if ((error = module_unload(mod, flags)) != 0) { 601 KLD_DPF(FILE, ("linker_file_unload: module %p" 602 " vetoes unload\n", mod)); 603 return (error); 604 } 605 MOD_XLOCK; 606 module_release(mod); 607 } 608 MOD_XUNLOCK; 609 610 TAILQ_FOREACH_SAFE(ml, &found_modules, link, nextml) { 611 if (ml->container == file) { 612 TAILQ_REMOVE(&found_modules, ml, link); 613 free(ml, M_LINKER); 614 } 615 } 616 617 /* 618 * Don't try to run SYSUNINITs if we are unloaded due to a 619 * link error. 620 */ 621 if (file->flags & LINKER_FILE_LINKED) { 622 linker_file_sysuninit(file); 623 linker_file_unregister_sysctls(file); 624 } 625 TAILQ_REMOVE(&linker_files, file, link); 626 627 if (file->deps) { 628 for (i = 0; i < file->ndeps; i++) 629 linker_file_unload(file->deps[i], flags); 630 free(file->deps, M_LINKER); 631 file->deps = NULL; 632 } 633 while ((cp = STAILQ_FIRST(&file->common)) != NULL) { 634 STAILQ_REMOVE_HEAD(&file->common, link); 635 free(cp, M_LINKER); 636 } 637 638 LINKER_UNLOAD(file); 639 if (file->filename) { 640 free(file->filename, M_LINKER); 641 file->filename = NULL; 642 } 643 if (file->pathname) { 644 free(file->pathname, M_LINKER); 645 file->pathname = NULL; 646 } 647 kobj_delete((kobj_t) file, M_LINKER); 648 return (0); 649 } 650 651 static int 652 linker_file_add_dependency(linker_file_t file, linker_file_t dep) 653 { 654 linker_file_t *newdeps; 655 656 KLD_LOCK_ASSERT(); 657 newdeps = malloc((file->ndeps + 1) * sizeof(linker_file_t *), 658 M_LINKER, M_WAITOK | M_ZERO); 659 if (newdeps == NULL) 660 return (ENOMEM); 661 662 if (file->deps) { 663 bcopy(file->deps, newdeps, 664 file->ndeps * sizeof(linker_file_t *)); 665 free(file->deps, M_LINKER); 666 } 667 file->deps = newdeps; 668 file->deps[file->ndeps] = dep; 669 file->ndeps++; 670 return (0); 671 } 672 673 /* 674 * Locate a linker set and its contents. This is a helper function to avoid 675 * linker_if.h exposure elsewhere. Note: firstp and lastp are really void **. 676 * This function is used in this file so we can avoid having lots of (void **) 677 * casts. 678 */ 679 int 680 linker_file_lookup_set(linker_file_t file, const char *name, 681 void *firstp, void *lastp, int *countp) 682 { 683 int error, locked; 684 685 locked = KLD_LOCKED(); 686 if (!locked) 687 KLD_LOCK(); 688 error = LINKER_LOOKUP_SET(file, name, firstp, lastp, countp); 689 if (!locked) 690 KLD_UNLOCK(); 691 return (error); 692 } 693 694 /* 695 * List all functions in a file. 696 */ 697 int 698 linker_file_function_listall(linker_file_t lf, 699 int (*callback_func)(linker_file_t, linker_symval_t *, void *), void *arg) 700 { 701 return (LINKER_EACH_FUNCTION_NAMEVAL(lf, callback_func, arg)); 702 } 703 704 caddr_t 705 linker_file_lookup_symbol(linker_file_t file, const char *name, int deps) 706 { 707 caddr_t sym; 708 int locked; 709 710 locked = KLD_LOCKED(); 711 if (!locked) 712 KLD_LOCK(); 713 sym = linker_file_lookup_symbol_internal(file, name, deps); 714 if (!locked) 715 KLD_UNLOCK(); 716 return (sym); 717 } 718 719 static caddr_t 720 linker_file_lookup_symbol_internal(linker_file_t file, const char *name, 721 int deps) 722 { 723 c_linker_sym_t sym; 724 linker_symval_t symval; 725 caddr_t address; 726 size_t common_size = 0; 727 int i; 728 729 KLD_LOCK_ASSERT(); 730 KLD_DPF(SYM, ("linker_file_lookup_symbol: file=%p, name=%s, deps=%d\n", 731 file, name, deps)); 732 733 if (LINKER_LOOKUP_SYMBOL(file, name, &sym) == 0) { 734 LINKER_SYMBOL_VALUES(file, sym, &symval); 735 if (symval.value == 0) 736 /* 737 * For commons, first look them up in the 738 * dependencies and only allocate space if not found 739 * there. 740 */ 741 common_size = symval.size; 742 else { 743 KLD_DPF(SYM, ("linker_file_lookup_symbol: symbol" 744 ".value=%p\n", symval.value)); 745 return (symval.value); 746 } 747 } 748 if (deps) { 749 for (i = 0; i < file->ndeps; i++) { 750 address = linker_file_lookup_symbol_internal( 751 file->deps[i], name, 0); 752 if (address) { 753 KLD_DPF(SYM, ("linker_file_lookup_symbol:" 754 " deps value=%p\n", address)); 755 return (address); 756 } 757 } 758 } 759 if (common_size > 0) { 760 /* 761 * This is a common symbol which was not found in the 762 * dependencies. We maintain a simple common symbol table in 763 * the file object. 764 */ 765 struct common_symbol *cp; 766 767 STAILQ_FOREACH(cp, &file->common, link) { 768 if (strcmp(cp->name, name) == 0) { 769 KLD_DPF(SYM, ("linker_file_lookup_symbol:" 770 " old common value=%p\n", cp->address)); 771 return (cp->address); 772 } 773 } 774 /* 775 * Round the symbol size up to align. 776 */ 777 common_size = (common_size + sizeof(int) - 1) & -sizeof(int); 778 cp = malloc(sizeof(struct common_symbol) 779 + common_size + strlen(name) + 1, M_LINKER, 780 M_WAITOK | M_ZERO); 781 cp->address = (caddr_t)(cp + 1); 782 cp->name = cp->address + common_size; 783 strcpy(cp->name, name); 784 bzero(cp->address, common_size); 785 STAILQ_INSERT_TAIL(&file->common, cp, link); 786 787 KLD_DPF(SYM, ("linker_file_lookup_symbol: new common" 788 " value=%p\n", cp->address)); 789 return (cp->address); 790 } 791 KLD_DPF(SYM, ("linker_file_lookup_symbol: fail\n")); 792 return (0); 793 } 794 795 /* 796 * Both DDB and stack(9) rely on the kernel linker to provide forward and 797 * backward lookup of symbols. However, DDB and sometimes stack(9) need to 798 * do this in a lockfree manner. We provide a set of internal helper 799 * routines to perform these operations without locks, and then wrappers that 800 * optionally lock. 801 * 802 * linker_debug_lookup() is ifdef DDB as currently it's only used by DDB. 803 */ 804 #ifdef DDB 805 static int 806 linker_debug_lookup(const char *symstr, c_linker_sym_t *sym) 807 { 808 linker_file_t lf; 809 810 TAILQ_FOREACH(lf, &linker_files, link) { 811 if (LINKER_LOOKUP_SYMBOL(lf, symstr, sym) == 0) 812 return (0); 813 } 814 return (ENOENT); 815 } 816 #endif 817 818 static int 819 linker_debug_search_symbol(caddr_t value, c_linker_sym_t *sym, long *diffp) 820 { 821 linker_file_t lf; 822 c_linker_sym_t best, es; 823 u_long diff, bestdiff, off; 824 825 best = 0; 826 off = (uintptr_t)value; 827 bestdiff = off; 828 TAILQ_FOREACH(lf, &linker_files, link) { 829 if (LINKER_SEARCH_SYMBOL(lf, value, &es, &diff) != 0) 830 continue; 831 if (es != 0 && diff < bestdiff) { 832 best = es; 833 bestdiff = diff; 834 } 835 if (bestdiff == 0) 836 break; 837 } 838 if (best) { 839 *sym = best; 840 *diffp = bestdiff; 841 return (0); 842 } else { 843 *sym = 0; 844 *diffp = off; 845 return (ENOENT); 846 } 847 } 848 849 static int 850 linker_debug_symbol_values(c_linker_sym_t sym, linker_symval_t *symval) 851 { 852 linker_file_t lf; 853 854 TAILQ_FOREACH(lf, &linker_files, link) { 855 if (LINKER_SYMBOL_VALUES(lf, sym, symval) == 0) 856 return (0); 857 } 858 return (ENOENT); 859 } 860 861 static int 862 linker_debug_search_symbol_name(caddr_t value, char *buf, u_int buflen, 863 long *offset) 864 { 865 linker_symval_t symval; 866 c_linker_sym_t sym; 867 int error; 868 869 *offset = 0; 870 error = linker_debug_search_symbol(value, &sym, offset); 871 if (error) 872 return (error); 873 error = linker_debug_symbol_values(sym, &symval); 874 if (error) 875 return (error); 876 strlcpy(buf, symval.name, buflen); 877 return (0); 878 } 879 880 #ifdef DDB 881 /* 882 * DDB Helpers. DDB has to look across multiple files with their own symbol 883 * tables and string tables. 884 * 885 * Note that we do not obey list locking protocols here. We really don't need 886 * DDB to hang because somebody's got the lock held. We'll take the chance 887 * that the files list is inconsistant instead. 888 */ 889 int 890 linker_ddb_lookup(const char *symstr, c_linker_sym_t *sym) 891 { 892 893 return (linker_debug_lookup(symstr, sym)); 894 } 895 896 int 897 linker_ddb_search_symbol(caddr_t value, c_linker_sym_t *sym, long *diffp) 898 { 899 900 return (linker_debug_search_symbol(value, sym, diffp)); 901 } 902 903 int 904 linker_ddb_symbol_values(c_linker_sym_t sym, linker_symval_t *symval) 905 { 906 907 return (linker_debug_symbol_values(sym, symval)); 908 } 909 910 int 911 linker_ddb_search_symbol_name(caddr_t value, char *buf, u_int buflen, 912 long *offset) 913 { 914 915 return (linker_debug_search_symbol_name(value, buf, buflen, offset)); 916 } 917 #endif 918 919 /* 920 * stack(9) helper for non-debugging environemnts. Unlike DDB helpers, we do 921 * obey locking protocols, and offer a significantly less complex interface. 922 */ 923 int 924 linker_search_symbol_name(caddr_t value, char *buf, u_int buflen, 925 long *offset) 926 { 927 int error; 928 929 KLD_LOCK(); 930 error = linker_debug_search_symbol_name(value, buf, buflen, offset); 931 KLD_UNLOCK(); 932 return (error); 933 } 934 935 /* 936 * Syscalls. 937 */ 938 int 939 kern_kldload(struct thread *td, const char *file, int *fileid) 940 { 941 #ifdef HWPMC_HOOKS 942 struct pmckern_map_in pkm; 943 #endif 944 const char *kldname, *modname; 945 linker_file_t lf; 946 int error; 947 948 if ((error = securelevel_gt(td->td_ucred, 0)) != 0) 949 return (error); 950 951 if ((error = priv_check(td, PRIV_KLD_LOAD)) != 0) 952 return (error); 953 954 /* 955 * If file does not contain a qualified name or any dot in it 956 * (kldname.ko, or kldname.ver.ko) treat it as an interface 957 * name. 958 */ 959 if (index(file, '/') || index(file, '.')) { 960 kldname = file; 961 modname = NULL; 962 } else { 963 kldname = NULL; 964 modname = file; 965 } 966 967 KLD_LOCK(); 968 error = linker_load_module(kldname, modname, NULL, NULL, &lf); 969 if (error) 970 goto unlock; 971 #ifdef HWPMC_HOOKS 972 pkm.pm_file = lf->filename; 973 pkm.pm_address = (uintptr_t) lf->address; 974 PMC_CALL_HOOK(td, PMC_FN_KLD_LOAD, (void *) &pkm); 975 #endif 976 lf->userrefs++; 977 if (fileid != NULL) 978 *fileid = lf->id; 979 unlock: 980 KLD_UNLOCK(); 981 return (error); 982 } 983 984 int 985 kldload(struct thread *td, struct kldload_args *uap) 986 { 987 char *pathname = NULL; 988 int error, fileid; 989 990 td->td_retval[0] = -1; 991 992 pathname = malloc(MAXPATHLEN, M_TEMP, M_WAITOK); 993 error = copyinstr(uap->file, pathname, MAXPATHLEN, NULL); 994 if (error == 0) { 995 error = kern_kldload(td, pathname, &fileid); 996 if (error == 0) 997 td->td_retval[0] = fileid; 998 } 999 free(pathname, M_TEMP); 1000 return (error); 1001 } 1002 1003 int 1004 kern_kldunload(struct thread *td, int fileid, int flags) 1005 { 1006 #ifdef HWPMC_HOOKS 1007 struct pmckern_map_out pkm; 1008 #endif 1009 linker_file_t lf; 1010 int error = 0; 1011 1012 if ((error = securelevel_gt(td->td_ucred, 0)) != 0) 1013 return (error); 1014 1015 if ((error = priv_check(td, PRIV_KLD_UNLOAD)) != 0) 1016 return (error); 1017 1018 KLD_LOCK(); 1019 lf = linker_find_file_by_id(fileid); 1020 if (lf) { 1021 KLD_DPF(FILE, ("kldunload: lf->userrefs=%d\n", lf->userrefs)); 1022 1023 /* Check if there are DTrace probes enabled on this file. */ 1024 if (lf->nenabled > 0) { 1025 printf("kldunload: attempt to unload file that has" 1026 " DTrace probes enabled\n"); 1027 error = EBUSY; 1028 } else if (lf->userrefs == 0) { 1029 /* 1030 * XXX: maybe LINKER_UNLOAD_FORCE should override ? 1031 */ 1032 printf("kldunload: attempt to unload file that was" 1033 " loaded by the kernel\n"); 1034 error = EBUSY; 1035 } else { 1036 #ifdef HWPMC_HOOKS 1037 /* Save data needed by hwpmc(4) before unloading. */ 1038 pkm.pm_address = (uintptr_t) lf->address; 1039 pkm.pm_size = lf->size; 1040 #endif 1041 lf->userrefs--; 1042 error = linker_file_unload(lf, flags); 1043 if (error) 1044 lf->userrefs++; 1045 } 1046 } else 1047 error = ENOENT; 1048 1049 #ifdef HWPMC_HOOKS 1050 if (error == 0) 1051 PMC_CALL_HOOK(td, PMC_FN_KLD_UNLOAD, (void *) &pkm); 1052 #endif 1053 KLD_UNLOCK(); 1054 return (error); 1055 } 1056 1057 int 1058 kldunload(struct thread *td, struct kldunload_args *uap) 1059 { 1060 1061 return (kern_kldunload(td, uap->fileid, LINKER_UNLOAD_NORMAL)); 1062 } 1063 1064 int 1065 kldunloadf(struct thread *td, struct kldunloadf_args *uap) 1066 { 1067 1068 if (uap->flags != LINKER_UNLOAD_NORMAL && 1069 uap->flags != LINKER_UNLOAD_FORCE) 1070 return (EINVAL); 1071 return (kern_kldunload(td, uap->fileid, uap->flags)); 1072 } 1073 1074 int 1075 kldfind(struct thread *td, struct kldfind_args *uap) 1076 { 1077 char *pathname; 1078 const char *filename; 1079 linker_file_t lf; 1080 int error; 1081 1082 #ifdef MAC 1083 error = mac_kld_check_stat(td->td_ucred); 1084 if (error) 1085 return (error); 1086 #endif 1087 1088 td->td_retval[0] = -1; 1089 1090 pathname = malloc(MAXPATHLEN, M_TEMP, M_WAITOK); 1091 if ((error = copyinstr(uap->file, pathname, MAXPATHLEN, NULL)) != 0) 1092 goto out; 1093 1094 filename = linker_basename(pathname); 1095 KLD_LOCK(); 1096 lf = linker_find_file_by_name(filename); 1097 if (lf) 1098 td->td_retval[0] = lf->id; 1099 else 1100 error = ENOENT; 1101 KLD_UNLOCK(); 1102 out: 1103 free(pathname, M_TEMP); 1104 return (error); 1105 } 1106 1107 int 1108 kldnext(struct thread *td, struct kldnext_args *uap) 1109 { 1110 linker_file_t lf; 1111 int error = 0; 1112 1113 #ifdef MAC 1114 error = mac_kld_check_stat(td->td_ucred); 1115 if (error) 1116 return (error); 1117 #endif 1118 1119 KLD_LOCK(); 1120 if (uap->fileid == 0) 1121 lf = TAILQ_FIRST(&linker_files); 1122 else { 1123 lf = linker_find_file_by_id(uap->fileid); 1124 if (lf == NULL) { 1125 error = ENOENT; 1126 goto out; 1127 } 1128 lf = TAILQ_NEXT(lf, link); 1129 } 1130 1131 /* Skip partially loaded files. */ 1132 while (lf != NULL && !(lf->flags & LINKER_FILE_LINKED)) 1133 lf = TAILQ_NEXT(lf, link); 1134 1135 if (lf) 1136 td->td_retval[0] = lf->id; 1137 else 1138 td->td_retval[0] = 0; 1139 out: 1140 KLD_UNLOCK(); 1141 return (error); 1142 } 1143 1144 int 1145 kldstat(struct thread *td, struct kldstat_args *uap) 1146 { 1147 struct kld_file_stat stat; 1148 linker_file_t lf; 1149 int error, namelen, version, version_num; 1150 1151 /* 1152 * Check the version of the user's structure. 1153 */ 1154 if ((error = copyin(&uap->stat->version, &version, sizeof(version))) != 0) 1155 return (error); 1156 if (version == sizeof(struct kld_file_stat_1)) 1157 version_num = 1; 1158 else if (version == sizeof(struct kld_file_stat)) 1159 version_num = 2; 1160 else 1161 return (EINVAL); 1162 1163 #ifdef MAC 1164 error = mac_kld_check_stat(td->td_ucred); 1165 if (error) 1166 return (error); 1167 #endif 1168 1169 KLD_LOCK(); 1170 lf = linker_find_file_by_id(uap->fileid); 1171 if (lf == NULL) { 1172 KLD_UNLOCK(); 1173 return (ENOENT); 1174 } 1175 1176 /* Version 1 fields: */ 1177 namelen = strlen(lf->filename) + 1; 1178 if (namelen > MAXPATHLEN) 1179 namelen = MAXPATHLEN; 1180 bcopy(lf->filename, &stat.name[0], namelen); 1181 stat.refs = lf->refs; 1182 stat.id = lf->id; 1183 stat.address = lf->address; 1184 stat.size = lf->size; 1185 if (version_num > 1) { 1186 /* Version 2 fields: */ 1187 namelen = strlen(lf->pathname) + 1; 1188 if (namelen > MAXPATHLEN) 1189 namelen = MAXPATHLEN; 1190 bcopy(lf->pathname, &stat.pathname[0], namelen); 1191 } 1192 KLD_UNLOCK(); 1193 1194 td->td_retval[0] = 0; 1195 1196 return (copyout(&stat, uap->stat, version)); 1197 } 1198 1199 int 1200 kldfirstmod(struct thread *td, struct kldfirstmod_args *uap) 1201 { 1202 linker_file_t lf; 1203 module_t mp; 1204 int error = 0; 1205 1206 #ifdef MAC 1207 error = mac_kld_check_stat(td->td_ucred); 1208 if (error) 1209 return (error); 1210 #endif 1211 1212 KLD_LOCK(); 1213 lf = linker_find_file_by_id(uap->fileid); 1214 if (lf) { 1215 MOD_SLOCK; 1216 mp = TAILQ_FIRST(&lf->modules); 1217 if (mp != NULL) 1218 td->td_retval[0] = module_getid(mp); 1219 else 1220 td->td_retval[0] = 0; 1221 MOD_SUNLOCK; 1222 } else 1223 error = ENOENT; 1224 KLD_UNLOCK(); 1225 return (error); 1226 } 1227 1228 int 1229 kldsym(struct thread *td, struct kldsym_args *uap) 1230 { 1231 char *symstr = NULL; 1232 c_linker_sym_t sym; 1233 linker_symval_t symval; 1234 linker_file_t lf; 1235 struct kld_sym_lookup lookup; 1236 int error = 0; 1237 1238 #ifdef MAC 1239 error = mac_kld_check_stat(td->td_ucred); 1240 if (error) 1241 return (error); 1242 #endif 1243 1244 if ((error = copyin(uap->data, &lookup, sizeof(lookup))) != 0) 1245 return (error); 1246 if (lookup.version != sizeof(lookup) || 1247 uap->cmd != KLDSYM_LOOKUP) 1248 return (EINVAL); 1249 symstr = malloc(MAXPATHLEN, M_TEMP, M_WAITOK); 1250 if ((error = copyinstr(lookup.symname, symstr, MAXPATHLEN, NULL)) != 0) 1251 goto out; 1252 KLD_LOCK(); 1253 if (uap->fileid != 0) { 1254 lf = linker_find_file_by_id(uap->fileid); 1255 if (lf == NULL) 1256 error = ENOENT; 1257 else if (LINKER_LOOKUP_SYMBOL(lf, symstr, &sym) == 0 && 1258 LINKER_SYMBOL_VALUES(lf, sym, &symval) == 0) { 1259 lookup.symvalue = (uintptr_t) symval.value; 1260 lookup.symsize = symval.size; 1261 error = copyout(&lookup, uap->data, sizeof(lookup)); 1262 } else 1263 error = ENOENT; 1264 } else { 1265 TAILQ_FOREACH(lf, &linker_files, link) { 1266 if (LINKER_LOOKUP_SYMBOL(lf, symstr, &sym) == 0 && 1267 LINKER_SYMBOL_VALUES(lf, sym, &symval) == 0) { 1268 lookup.symvalue = (uintptr_t)symval.value; 1269 lookup.symsize = symval.size; 1270 error = copyout(&lookup, uap->data, 1271 sizeof(lookup)); 1272 break; 1273 } 1274 } 1275 if (lf == NULL) 1276 error = ENOENT; 1277 } 1278 KLD_UNLOCK(); 1279 out: 1280 free(symstr, M_TEMP); 1281 return (error); 1282 } 1283 1284 /* 1285 * Preloaded module support 1286 */ 1287 1288 static modlist_t 1289 modlist_lookup(const char *name, int ver) 1290 { 1291 modlist_t mod; 1292 1293 TAILQ_FOREACH(mod, &found_modules, link) { 1294 if (strcmp(mod->name, name) == 0 && 1295 (ver == 0 || mod->version == ver)) 1296 return (mod); 1297 } 1298 return (NULL); 1299 } 1300 1301 static modlist_t 1302 modlist_lookup2(const char *name, struct mod_depend *verinfo) 1303 { 1304 modlist_t mod, bestmod; 1305 int ver; 1306 1307 if (verinfo == NULL) 1308 return (modlist_lookup(name, 0)); 1309 bestmod = NULL; 1310 TAILQ_FOREACH(mod, &found_modules, link) { 1311 if (strcmp(mod->name, name) != 0) 1312 continue; 1313 ver = mod->version; 1314 if (ver == verinfo->md_ver_preferred) 1315 return (mod); 1316 if (ver >= verinfo->md_ver_minimum && 1317 ver <= verinfo->md_ver_maximum && 1318 (bestmod == NULL || ver > bestmod->version)) 1319 bestmod = mod; 1320 } 1321 return (bestmod); 1322 } 1323 1324 static modlist_t 1325 modlist_newmodule(const char *modname, int version, linker_file_t container) 1326 { 1327 modlist_t mod; 1328 1329 mod = malloc(sizeof(struct modlist), M_LINKER, M_NOWAIT | M_ZERO); 1330 if (mod == NULL) 1331 panic("no memory for module list"); 1332 mod->container = container; 1333 mod->name = modname; 1334 mod->version = version; 1335 TAILQ_INSERT_TAIL(&found_modules, mod, link); 1336 return (mod); 1337 } 1338 1339 static void 1340 linker_addmodules(linker_file_t lf, struct mod_metadata **start, 1341 struct mod_metadata **stop, int preload) 1342 { 1343 struct mod_metadata *mp, **mdp; 1344 const char *modname; 1345 int ver; 1346 1347 for (mdp = start; mdp < stop; mdp++) { 1348 mp = *mdp; 1349 if (mp->md_type != MDT_VERSION) 1350 continue; 1351 modname = mp->md_cval; 1352 ver = ((struct mod_version *)mp->md_data)->mv_version; 1353 if (modlist_lookup(modname, ver) != NULL) { 1354 printf("module %s already present!\n", modname); 1355 /* XXX what can we do? this is a build error. :-( */ 1356 continue; 1357 } 1358 modlist_newmodule(modname, ver, lf); 1359 } 1360 } 1361 1362 static void 1363 linker_preload(void *arg) 1364 { 1365 caddr_t modptr; 1366 const char *modname, *nmodname; 1367 char *modtype; 1368 linker_file_t lf, nlf; 1369 linker_class_t lc; 1370 int error; 1371 linker_file_list_t loaded_files; 1372 linker_file_list_t depended_files; 1373 struct mod_metadata *mp, *nmp; 1374 struct mod_metadata **start, **stop, **mdp, **nmdp; 1375 struct mod_depend *verinfo; 1376 int nver; 1377 int resolves; 1378 modlist_t mod; 1379 struct sysinit **si_start, **si_stop; 1380 1381 TAILQ_INIT(&loaded_files); 1382 TAILQ_INIT(&depended_files); 1383 TAILQ_INIT(&found_modules); 1384 error = 0; 1385 1386 modptr = NULL; 1387 while ((modptr = preload_search_next_name(modptr)) != NULL) { 1388 modname = (char *)preload_search_info(modptr, MODINFO_NAME); 1389 modtype = (char *)preload_search_info(modptr, MODINFO_TYPE); 1390 if (modname == NULL) { 1391 printf("Preloaded module at %p does not have a" 1392 " name!\n", modptr); 1393 continue; 1394 } 1395 if (modtype == NULL) { 1396 printf("Preloaded module at %p does not have a type!\n", 1397 modptr); 1398 continue; 1399 } 1400 if (bootverbose) 1401 printf("Preloaded %s \"%s\" at %p.\n", modtype, modname, 1402 modptr); 1403 lf = NULL; 1404 TAILQ_FOREACH(lc, &classes, link) { 1405 error = LINKER_LINK_PRELOAD(lc, modname, &lf); 1406 if (!error) 1407 break; 1408 lf = NULL; 1409 } 1410 if (lf) 1411 TAILQ_INSERT_TAIL(&loaded_files, lf, loaded); 1412 } 1413 1414 /* 1415 * First get a list of stuff in the kernel. 1416 */ 1417 if (linker_file_lookup_set(linker_kernel_file, MDT_SETNAME, &start, 1418 &stop, NULL) == 0) 1419 linker_addmodules(linker_kernel_file, start, stop, 1); 1420 1421 /* 1422 * This is a once-off kinky bubble sort to resolve relocation 1423 * dependency requirements. 1424 */ 1425 restart: 1426 TAILQ_FOREACH(lf, &loaded_files, loaded) { 1427 error = linker_file_lookup_set(lf, MDT_SETNAME, &start, 1428 &stop, NULL); 1429 /* 1430 * First, look to see if we would successfully link with this 1431 * stuff. 1432 */ 1433 resolves = 1; /* unless we know otherwise */ 1434 if (!error) { 1435 for (mdp = start; mdp < stop; mdp++) { 1436 mp = *mdp; 1437 if (mp->md_type != MDT_DEPEND) 1438 continue; 1439 modname = mp->md_cval; 1440 verinfo = mp->md_data; 1441 for (nmdp = start; nmdp < stop; nmdp++) { 1442 nmp = *nmdp; 1443 if (nmp->md_type != MDT_VERSION) 1444 continue; 1445 nmodname = nmp->md_cval; 1446 if (strcmp(modname, nmodname) == 0) 1447 break; 1448 } 1449 if (nmdp < stop) /* it's a self reference */ 1450 continue; 1451 1452 /* 1453 * ok, the module isn't here yet, we 1454 * are not finished 1455 */ 1456 if (modlist_lookup2(modname, verinfo) == NULL) 1457 resolves = 0; 1458 } 1459 } 1460 /* 1461 * OK, if we found our modules, we can link. So, "provide" 1462 * the modules inside and add it to the end of the link order 1463 * list. 1464 */ 1465 if (resolves) { 1466 if (!error) { 1467 for (mdp = start; mdp < stop; mdp++) { 1468 mp = *mdp; 1469 if (mp->md_type != MDT_VERSION) 1470 continue; 1471 modname = mp->md_cval; 1472 nver = ((struct mod_version *) 1473 mp->md_data)->mv_version; 1474 if (modlist_lookup(modname, 1475 nver) != NULL) { 1476 printf("module %s already" 1477 " present!\n", modname); 1478 TAILQ_REMOVE(&loaded_files, 1479 lf, loaded); 1480 linker_file_unload(lf, 1481 LINKER_UNLOAD_FORCE); 1482 /* we changed tailq next ptr */ 1483 goto restart; 1484 } 1485 modlist_newmodule(modname, nver, lf); 1486 } 1487 } 1488 TAILQ_REMOVE(&loaded_files, lf, loaded); 1489 TAILQ_INSERT_TAIL(&depended_files, lf, loaded); 1490 /* 1491 * Since we provided modules, we need to restart the 1492 * sort so that the previous files that depend on us 1493 * have a chance. Also, we've busted the tailq next 1494 * pointer with the REMOVE. 1495 */ 1496 goto restart; 1497 } 1498 } 1499 1500 /* 1501 * At this point, we check to see what could not be resolved.. 1502 */ 1503 while ((lf = TAILQ_FIRST(&loaded_files)) != NULL) { 1504 TAILQ_REMOVE(&loaded_files, lf, loaded); 1505 printf("KLD file %s is missing dependencies\n", lf->filename); 1506 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 1507 } 1508 1509 /* 1510 * We made it. Finish off the linking in the order we determined. 1511 */ 1512 TAILQ_FOREACH_SAFE(lf, &depended_files, loaded, nlf) { 1513 if (linker_kernel_file) { 1514 linker_kernel_file->refs++; 1515 error = linker_file_add_dependency(lf, 1516 linker_kernel_file); 1517 if (error) 1518 panic("cannot add dependency"); 1519 } 1520 lf->userrefs++; /* so we can (try to) kldunload it */ 1521 error = linker_file_lookup_set(lf, MDT_SETNAME, &start, 1522 &stop, NULL); 1523 if (!error) { 1524 for (mdp = start; mdp < stop; mdp++) { 1525 mp = *mdp; 1526 if (mp->md_type != MDT_DEPEND) 1527 continue; 1528 modname = mp->md_cval; 1529 verinfo = mp->md_data; 1530 mod = modlist_lookup2(modname, verinfo); 1531 /* Don't count self-dependencies */ 1532 if (lf == mod->container) 1533 continue; 1534 mod->container->refs++; 1535 error = linker_file_add_dependency(lf, 1536 mod->container); 1537 if (error) 1538 panic("cannot add dependency"); 1539 } 1540 } 1541 /* 1542 * Now do relocation etc using the symbol search paths 1543 * established by the dependencies 1544 */ 1545 error = LINKER_LINK_PRELOAD_FINISH(lf); 1546 if (error) { 1547 TAILQ_REMOVE(&depended_files, lf, loaded); 1548 printf("KLD file %s - could not finalize loading\n", 1549 lf->filename); 1550 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 1551 continue; 1552 } 1553 linker_file_register_modules(lf); 1554 if (linker_file_lookup_set(lf, "sysinit_set", &si_start, 1555 &si_stop, NULL) == 0) 1556 sysinit_add(si_start, si_stop); 1557 linker_file_register_sysctls(lf); 1558 lf->flags |= LINKER_FILE_LINKED; 1559 } 1560 /* woohoo! we made it! */ 1561 } 1562 1563 SYSINIT(preload, SI_SUB_KLD, SI_ORDER_MIDDLE, linker_preload, 0); 1564 1565 /* 1566 * Search for a not-loaded module by name. 1567 * 1568 * Modules may be found in the following locations: 1569 * 1570 * - preloaded (result is just the module name) - on disk (result is full path 1571 * to module) 1572 * 1573 * If the module name is qualified in any way (contains path, etc.) the we 1574 * simply return a copy of it. 1575 * 1576 * The search path can be manipulated via sysctl. Note that we use the ';' 1577 * character as a separator to be consistent with the bootloader. 1578 */ 1579 1580 static char linker_hintfile[] = "linker.hints"; 1581 static char linker_path[MAXPATHLEN] = "/boot/kernel;/boot/modules"; 1582 1583 SYSCTL_STRING(_kern, OID_AUTO, module_path, CTLFLAG_RW, linker_path, 1584 sizeof(linker_path), "module load search path"); 1585 1586 TUNABLE_STR("module_path", linker_path, sizeof(linker_path)); 1587 1588 static char *linker_ext_list[] = { 1589 "", 1590 ".ko", 1591 NULL 1592 }; 1593 1594 /* 1595 * Check if file actually exists either with or without extension listed in 1596 * the linker_ext_list. (probably should be generic for the rest of the 1597 * kernel) 1598 */ 1599 static char * 1600 linker_lookup_file(const char *path, int pathlen, const char *name, 1601 int namelen, struct vattr *vap) 1602 { 1603 struct nameidata nd; 1604 struct thread *td = curthread; /* XXX */ 1605 char *result, **cpp, *sep; 1606 int error, len, extlen, reclen, flags, vfslocked; 1607 enum vtype type; 1608 1609 extlen = 0; 1610 for (cpp = linker_ext_list; *cpp; cpp++) { 1611 len = strlen(*cpp); 1612 if (len > extlen) 1613 extlen = len; 1614 } 1615 extlen++; /* trailing '\0' */ 1616 sep = (path[pathlen - 1] != '/') ? "/" : ""; 1617 1618 reclen = pathlen + strlen(sep) + namelen + extlen + 1; 1619 result = malloc(reclen, M_LINKER, M_WAITOK); 1620 for (cpp = linker_ext_list; *cpp; cpp++) { 1621 snprintf(result, reclen, "%.*s%s%.*s%s", pathlen, path, sep, 1622 namelen, name, *cpp); 1623 /* 1624 * Attempt to open the file, and return the path if 1625 * we succeed and it's a regular file. 1626 */ 1627 NDINIT(&nd, LOOKUP, FOLLOW | MPSAFE, UIO_SYSSPACE, result, td); 1628 flags = FREAD; 1629 error = vn_open(&nd, &flags, 0, NULL); 1630 if (error == 0) { 1631 vfslocked = NDHASGIANT(&nd); 1632 NDFREE(&nd, NDF_ONLY_PNBUF); 1633 type = nd.ni_vp->v_type; 1634 if (vap) 1635 VOP_GETATTR(nd.ni_vp, vap, td->td_ucred, td); 1636 VOP_UNLOCK(nd.ni_vp, 0); 1637 vn_close(nd.ni_vp, FREAD, td->td_ucred, td); 1638 VFS_UNLOCK_GIANT(vfslocked); 1639 if (type == VREG) 1640 return (result); 1641 } 1642 } 1643 free(result, M_LINKER); 1644 return (NULL); 1645 } 1646 1647 #define INT_ALIGN(base, ptr) ptr = \ 1648 (base) + (((ptr) - (base) + sizeof(int) - 1) & ~(sizeof(int) - 1)) 1649 1650 /* 1651 * Lookup KLD which contains requested module in the "linker.hints" file. If 1652 * version specification is available, then try to find the best KLD. 1653 * Otherwise just find the latest one. 1654 */ 1655 static char * 1656 linker_hints_lookup(const char *path, int pathlen, const char *modname, 1657 int modnamelen, struct mod_depend *verinfo) 1658 { 1659 struct thread *td = curthread; /* XXX */ 1660 struct ucred *cred = td ? td->td_ucred : NULL; 1661 struct nameidata nd; 1662 struct vattr vattr, mattr; 1663 u_char *hints = NULL; 1664 u_char *cp, *recptr, *bufend, *result, *best, *pathbuf, *sep; 1665 int error, ival, bestver, *intp, reclen, found, flags, clen, blen; 1666 int vfslocked = 0; 1667 1668 result = NULL; 1669 bestver = found = 0; 1670 1671 sep = (path[pathlen - 1] != '/') ? "/" : ""; 1672 reclen = imax(modnamelen, strlen(linker_hintfile)) + pathlen + 1673 strlen(sep) + 1; 1674 pathbuf = malloc(reclen, M_LINKER, M_WAITOK); 1675 snprintf(pathbuf, reclen, "%.*s%s%s", pathlen, path, sep, 1676 linker_hintfile); 1677 1678 NDINIT(&nd, LOOKUP, NOFOLLOW | MPSAFE, UIO_SYSSPACE, pathbuf, td); 1679 flags = FREAD; 1680 error = vn_open(&nd, &flags, 0, NULL); 1681 if (error) 1682 goto bad; 1683 vfslocked = NDHASGIANT(&nd); 1684 NDFREE(&nd, NDF_ONLY_PNBUF); 1685 if (nd.ni_vp->v_type != VREG) 1686 goto bad; 1687 best = cp = NULL; 1688 error = VOP_GETATTR(nd.ni_vp, &vattr, cred, td); 1689 if (error) 1690 goto bad; 1691 /* 1692 * XXX: we need to limit this number to some reasonable value 1693 */ 1694 if (vattr.va_size > 100 * 1024) { 1695 printf("hints file too large %ld\n", (long)vattr.va_size); 1696 goto bad; 1697 } 1698 hints = malloc(vattr.va_size, M_TEMP, M_WAITOK); 1699 if (hints == NULL) 1700 goto bad; 1701 error = vn_rdwr(UIO_READ, nd.ni_vp, (caddr_t)hints, vattr.va_size, 0, 1702 UIO_SYSSPACE, IO_NODELOCKED, cred, NOCRED, &reclen, td); 1703 if (error) 1704 goto bad; 1705 VOP_UNLOCK(nd.ni_vp, 0); 1706 vn_close(nd.ni_vp, FREAD, cred, td); 1707 VFS_UNLOCK_GIANT(vfslocked); 1708 nd.ni_vp = NULL; 1709 if (reclen != 0) { 1710 printf("can't read %d\n", reclen); 1711 goto bad; 1712 } 1713 intp = (int *)hints; 1714 ival = *intp++; 1715 if (ival != LINKER_HINTS_VERSION) { 1716 printf("hints file version mismatch %d\n", ival); 1717 goto bad; 1718 } 1719 bufend = hints + vattr.va_size; 1720 recptr = (u_char *)intp; 1721 clen = blen = 0; 1722 while (recptr < bufend && !found) { 1723 intp = (int *)recptr; 1724 reclen = *intp++; 1725 ival = *intp++; 1726 cp = (char *)intp; 1727 switch (ival) { 1728 case MDT_VERSION: 1729 clen = *cp++; 1730 if (clen != modnamelen || bcmp(cp, modname, clen) != 0) 1731 break; 1732 cp += clen; 1733 INT_ALIGN(hints, cp); 1734 ival = *(int *)cp; 1735 cp += sizeof(int); 1736 clen = *cp++; 1737 if (verinfo == NULL || 1738 ival == verinfo->md_ver_preferred) { 1739 found = 1; 1740 break; 1741 } 1742 if (ival >= verinfo->md_ver_minimum && 1743 ival <= verinfo->md_ver_maximum && 1744 ival > bestver) { 1745 bestver = ival; 1746 best = cp; 1747 blen = clen; 1748 } 1749 break; 1750 default: 1751 break; 1752 } 1753 recptr += reclen + sizeof(int); 1754 } 1755 /* 1756 * Finally check if KLD is in the place 1757 */ 1758 if (found) 1759 result = linker_lookup_file(path, pathlen, cp, clen, &mattr); 1760 else if (best) 1761 result = linker_lookup_file(path, pathlen, best, blen, &mattr); 1762 1763 /* 1764 * KLD is newer than hints file. What we should do now? 1765 */ 1766 if (result && timespeccmp(&mattr.va_mtime, &vattr.va_mtime, >)) 1767 printf("warning: KLD '%s' is newer than the linker.hints" 1768 " file\n", result); 1769 bad: 1770 free(pathbuf, M_LINKER); 1771 if (hints) 1772 free(hints, M_TEMP); 1773 if (nd.ni_vp != NULL) { 1774 VOP_UNLOCK(nd.ni_vp, 0); 1775 vn_close(nd.ni_vp, FREAD, cred, td); 1776 VFS_UNLOCK_GIANT(vfslocked); 1777 } 1778 /* 1779 * If nothing found or hints is absent - fallback to the old 1780 * way by using "kldname[.ko]" as module name. 1781 */ 1782 if (!found && !bestver && result == NULL) 1783 result = linker_lookup_file(path, pathlen, modname, 1784 modnamelen, NULL); 1785 return (result); 1786 } 1787 1788 /* 1789 * Lookup KLD which contains requested module in the all directories. 1790 */ 1791 static char * 1792 linker_search_module(const char *modname, int modnamelen, 1793 struct mod_depend *verinfo) 1794 { 1795 char *cp, *ep, *result; 1796 1797 /* 1798 * traverse the linker path 1799 */ 1800 for (cp = linker_path; *cp; cp = ep + 1) { 1801 /* find the end of this component */ 1802 for (ep = cp; (*ep != 0) && (*ep != ';'); ep++); 1803 result = linker_hints_lookup(cp, ep - cp, modname, 1804 modnamelen, verinfo); 1805 if (result != NULL) 1806 return (result); 1807 if (*ep == 0) 1808 break; 1809 } 1810 return (NULL); 1811 } 1812 1813 /* 1814 * Search for module in all directories listed in the linker_path. 1815 */ 1816 static char * 1817 linker_search_kld(const char *name) 1818 { 1819 char *cp, *ep, *result; 1820 int len; 1821 1822 /* qualified at all? */ 1823 if (index(name, '/')) 1824 return (linker_strdup(name)); 1825 1826 /* traverse the linker path */ 1827 len = strlen(name); 1828 for (ep = linker_path; *ep; ep++) { 1829 cp = ep; 1830 /* find the end of this component */ 1831 for (; *ep != 0 && *ep != ';'; ep++); 1832 result = linker_lookup_file(cp, ep - cp, name, len, NULL); 1833 if (result != NULL) 1834 return (result); 1835 } 1836 return (NULL); 1837 } 1838 1839 static const char * 1840 linker_basename(const char *path) 1841 { 1842 const char *filename; 1843 1844 filename = rindex(path, '/'); 1845 if (filename == NULL) 1846 return path; 1847 if (filename[1]) 1848 filename++; 1849 return (filename); 1850 } 1851 1852 #ifdef HWPMC_HOOKS 1853 1854 struct hwpmc_context { 1855 int nobjects; 1856 int nmappings; 1857 struct pmckern_map_in *kobase; 1858 }; 1859 1860 static int 1861 linker_hwpmc_list_object(linker_file_t lf, void *arg) 1862 { 1863 struct hwpmc_context *hc; 1864 1865 hc = arg; 1866 1867 /* If we run out of mappings, fail. */ 1868 if (hc->nobjects >= hc->nmappings) 1869 return (1); 1870 1871 /* Save the info for this linker file. */ 1872 hc->kobase[hc->nobjects].pm_file = lf->filename; 1873 hc->kobase[hc->nobjects].pm_address = (uintptr_t)lf->address; 1874 hc->nobjects++; 1875 return (0); 1876 } 1877 1878 /* 1879 * Inform hwpmc about the set of kernel modules currently loaded. 1880 */ 1881 void * 1882 linker_hwpmc_list_objects(void) 1883 { 1884 struct hwpmc_context hc; 1885 1886 hc.nmappings = 15; /* a reasonable default */ 1887 1888 retry: 1889 /* allocate nmappings+1 entries */ 1890 MALLOC(hc.kobase, struct pmckern_map_in *, 1891 (hc.nmappings + 1) * sizeof(struct pmckern_map_in), M_LINKER, 1892 M_WAITOK | M_ZERO); 1893 1894 hc.nobjects = 0; 1895 if (linker_file_foreach(linker_hwpmc_list_object, &hc) != 0) { 1896 hc.nmappings = hc.nobjects; 1897 FREE(hc.kobase, M_LINKER); 1898 goto retry; 1899 } 1900 1901 KASSERT(hc.nobjects > 0, ("linker_hpwmc_list_objects: no kernel " 1902 "objects?")); 1903 1904 /* The last entry of the malloced area comprises of all zeros. */ 1905 KASSERT(hc.kobase[hc.nobjects].pm_file == NULL, 1906 ("linker_hwpmc_list_objects: last object not NULL")); 1907 1908 return ((void *)hc.kobase); 1909 } 1910 #endif 1911 1912 /* 1913 * Find a file which contains given module and load it, if "parent" is not 1914 * NULL, register a reference to it. 1915 */ 1916 static int 1917 linker_load_module(const char *kldname, const char *modname, 1918 struct linker_file *parent, struct mod_depend *verinfo, 1919 struct linker_file **lfpp) 1920 { 1921 linker_file_t lfdep; 1922 const char *filename; 1923 char *pathname; 1924 int error; 1925 1926 KLD_LOCK_ASSERT(); 1927 if (modname == NULL) { 1928 /* 1929 * We have to load KLD 1930 */ 1931 KASSERT(verinfo == NULL, ("linker_load_module: verinfo" 1932 " is not NULL")); 1933 pathname = linker_search_kld(kldname); 1934 } else { 1935 if (modlist_lookup2(modname, verinfo) != NULL) 1936 return (EEXIST); 1937 if (kldname != NULL) 1938 pathname = linker_strdup(kldname); 1939 else if (rootvnode == NULL) 1940 pathname = NULL; 1941 else 1942 /* 1943 * Need to find a KLD with required module 1944 */ 1945 pathname = linker_search_module(modname, 1946 strlen(modname), verinfo); 1947 } 1948 if (pathname == NULL) 1949 return (ENOENT); 1950 1951 /* 1952 * Can't load more than one file with the same basename XXX: 1953 * Actually it should be possible to have multiple KLDs with 1954 * the same basename but different path because they can 1955 * provide different versions of the same modules. 1956 */ 1957 filename = linker_basename(pathname); 1958 if (linker_find_file_by_name(filename)) 1959 error = EEXIST; 1960 else do { 1961 error = linker_load_file(pathname, &lfdep); 1962 if (error) 1963 break; 1964 if (modname && verinfo && 1965 modlist_lookup2(modname, verinfo) == NULL) { 1966 linker_file_unload(lfdep, LINKER_UNLOAD_FORCE); 1967 error = ENOENT; 1968 break; 1969 } 1970 if (parent) { 1971 error = linker_file_add_dependency(parent, lfdep); 1972 if (error) 1973 break; 1974 } 1975 if (lfpp) 1976 *lfpp = lfdep; 1977 } while (0); 1978 free(pathname, M_LINKER); 1979 return (error); 1980 } 1981 1982 /* 1983 * This routine is responsible for finding dependencies of userland initiated 1984 * kldload(2)'s of files. 1985 */ 1986 int 1987 linker_load_dependencies(linker_file_t lf) 1988 { 1989 linker_file_t lfdep; 1990 struct mod_metadata **start, **stop, **mdp, **nmdp; 1991 struct mod_metadata *mp, *nmp; 1992 struct mod_depend *verinfo; 1993 modlist_t mod; 1994 const char *modname, *nmodname; 1995 int ver, error = 0, count; 1996 1997 /* 1998 * All files are dependant on /kernel. 1999 */ 2000 KLD_LOCK_ASSERT(); 2001 if (linker_kernel_file) { 2002 linker_kernel_file->refs++; 2003 error = linker_file_add_dependency(lf, linker_kernel_file); 2004 if (error) 2005 return (error); 2006 } 2007 if (linker_file_lookup_set(lf, MDT_SETNAME, &start, &stop, 2008 &count) != 0) 2009 return (0); 2010 for (mdp = start; mdp < stop; mdp++) { 2011 mp = *mdp; 2012 if (mp->md_type != MDT_VERSION) 2013 continue; 2014 modname = mp->md_cval; 2015 ver = ((struct mod_version *)mp->md_data)->mv_version; 2016 mod = modlist_lookup(modname, ver); 2017 if (mod != NULL) { 2018 printf("interface %s.%d already present in the KLD" 2019 " '%s'!\n", modname, ver, 2020 mod->container->filename); 2021 return (EEXIST); 2022 } 2023 } 2024 2025 for (mdp = start; mdp < stop; mdp++) { 2026 mp = *mdp; 2027 if (mp->md_type != MDT_DEPEND) 2028 continue; 2029 modname = mp->md_cval; 2030 verinfo = mp->md_data; 2031 nmodname = NULL; 2032 for (nmdp = start; nmdp < stop; nmdp++) { 2033 nmp = *nmdp; 2034 if (nmp->md_type != MDT_VERSION) 2035 continue; 2036 nmodname = nmp->md_cval; 2037 if (strcmp(modname, nmodname) == 0) 2038 break; 2039 } 2040 if (nmdp < stop)/* early exit, it's a self reference */ 2041 continue; 2042 mod = modlist_lookup2(modname, verinfo); 2043 if (mod) { /* woohoo, it's loaded already */ 2044 lfdep = mod->container; 2045 lfdep->refs++; 2046 error = linker_file_add_dependency(lf, lfdep); 2047 if (error) 2048 break; 2049 continue; 2050 } 2051 error = linker_load_module(NULL, modname, lf, verinfo, NULL); 2052 if (error) { 2053 printf("KLD %s: depends on %s - not available\n", 2054 lf->filename, modname); 2055 break; 2056 } 2057 } 2058 2059 if (error) 2060 return (error); 2061 linker_addmodules(lf, start, stop, 0); 2062 return (error); 2063 } 2064 2065 static int 2066 sysctl_kern_function_list_iterate(const char *name, void *opaque) 2067 { 2068 struct sysctl_req *req; 2069 2070 req = opaque; 2071 return (SYSCTL_OUT(req, name, strlen(name) + 1)); 2072 } 2073 2074 /* 2075 * Export a nul-separated, double-nul-terminated list of all function names 2076 * in the kernel. 2077 */ 2078 static int 2079 sysctl_kern_function_list(SYSCTL_HANDLER_ARGS) 2080 { 2081 linker_file_t lf; 2082 int error; 2083 2084 #ifdef MAC 2085 error = mac_kld_check_stat(req->td->td_ucred); 2086 if (error) 2087 return (error); 2088 #endif 2089 error = sysctl_wire_old_buffer(req, 0); 2090 if (error != 0) 2091 return (error); 2092 KLD_LOCK(); 2093 TAILQ_FOREACH(lf, &linker_files, link) { 2094 error = LINKER_EACH_FUNCTION_NAME(lf, 2095 sysctl_kern_function_list_iterate, req); 2096 if (error) { 2097 KLD_UNLOCK(); 2098 return (error); 2099 } 2100 } 2101 KLD_UNLOCK(); 2102 return (SYSCTL_OUT(req, "", 1)); 2103 } 2104 2105 SYSCTL_PROC(_kern, OID_AUTO, function_list, CTLFLAG_RD, 2106 NULL, 0, sysctl_kern_function_list, "", "kernel function list"); 2107