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 33 #include <sys/param.h> 34 #include <sys/kernel.h> 35 #include <sys/systm.h> 36 #include <sys/malloc.h> 37 #include <sys/sysproto.h> 38 #include <sys/sysent.h> 39 #include <sys/priv.h> 40 #include <sys/proc.h> 41 #include <sys/lock.h> 42 #include <sys/mutex.h> 43 #include <sys/sx.h> 44 #include <sys/module.h> 45 #include <sys/mount.h> 46 #include <sys/linker.h> 47 #include <sys/fcntl.h> 48 #include <sys/jail.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 <net/vnet.h> 56 57 #include <security/mac/mac_framework.h> 58 59 #include "linker_if.h" 60 61 #ifdef HWPMC_HOOKS 62 #include <sys/pmckern.h> 63 #endif 64 65 #ifdef KLD_DEBUG 66 int kld_debug = 0; 67 SYSCTL_INT(_debug, OID_AUTO, kld_debug, CTLFLAG_RW, 68 &kld_debug, 0, "Set various levels of KLD debug"); 69 #endif 70 71 #define KLD_LOCK() sx_xlock(&kld_sx) 72 #define KLD_UNLOCK() sx_xunlock(&kld_sx) 73 #define KLD_LOCKED() sx_xlocked(&kld_sx) 74 #define KLD_LOCK_ASSERT() do { \ 75 if (!cold) \ 76 sx_assert(&kld_sx, SX_XLOCKED); \ 77 } while (0) 78 79 /* 80 * static char *linker_search_path(const char *name, struct mod_depend 81 * *verinfo); 82 */ 83 static const char *linker_basename(const char *path); 84 85 /* 86 * Find a currently loaded file given its filename. 87 */ 88 static linker_file_t linker_find_file_by_name(const char* _filename); 89 90 /* 91 * Find a currently loaded file given its file id. 92 */ 93 static linker_file_t linker_find_file_by_id(int _fileid); 94 95 /* Metadata from the static kernel */ 96 SET_DECLARE(modmetadata_set, struct mod_metadata); 97 98 MALLOC_DEFINE(M_LINKER, "linker", "kernel linker"); 99 100 linker_file_t linker_kernel_file; 101 102 static struct sx kld_sx; /* kernel linker lock */ 103 104 /* 105 * Load counter used by clients to determine if a linker file has been 106 * re-loaded. This counter is incremented for each file load. 107 */ 108 static int loadcnt; 109 110 static linker_class_list_t classes; 111 static linker_file_list_t linker_files; 112 static int next_file_id = 1; 113 static int linker_no_more_classes = 0; 114 115 #define LINKER_GET_NEXT_FILE_ID(a) do { \ 116 linker_file_t lftmp; \ 117 \ 118 KLD_LOCK_ASSERT(); \ 119 retry: \ 120 TAILQ_FOREACH(lftmp, &linker_files, link) { \ 121 if (next_file_id == lftmp->id) { \ 122 next_file_id++; \ 123 goto retry; \ 124 } \ 125 } \ 126 (a) = next_file_id; \ 127 } while(0) 128 129 130 /* XXX wrong name; we're looking at version provision tags here, not modules */ 131 typedef TAILQ_HEAD(, modlist) modlisthead_t; 132 struct modlist { 133 TAILQ_ENTRY(modlist) link; /* chain together all modules */ 134 linker_file_t container; 135 const char *name; 136 int version; 137 }; 138 typedef struct modlist *modlist_t; 139 static modlisthead_t found_modules; 140 141 static int linker_file_add_dependency(linker_file_t file, 142 linker_file_t dep); 143 static caddr_t linker_file_lookup_symbol_internal(linker_file_t file, 144 const char* name, int deps); 145 static int linker_load_module(const char *kldname, 146 const char *modname, struct linker_file *parent, 147 struct mod_depend *verinfo, struct linker_file **lfpp); 148 static modlist_t modlist_lookup2(const char *name, struct mod_depend *verinfo); 149 150 static char * 151 linker_strdup(const char *str) 152 { 153 char *result; 154 155 if ((result = malloc((strlen(str) + 1), M_LINKER, M_WAITOK)) != NULL) 156 strcpy(result, str); 157 return (result); 158 } 159 160 static void 161 linker_init(void *arg) 162 { 163 164 sx_init(&kld_sx, "kernel linker"); 165 TAILQ_INIT(&classes); 166 TAILQ_INIT(&linker_files); 167 } 168 169 SYSINIT(linker, SI_SUB_KLD, SI_ORDER_FIRST, linker_init, 0); 170 171 static void 172 linker_stop_class_add(void *arg) 173 { 174 175 linker_no_more_classes = 1; 176 } 177 178 SYSINIT(linker_class, SI_SUB_KLD, SI_ORDER_ANY, linker_stop_class_add, NULL); 179 180 int 181 linker_add_class(linker_class_t lc) 182 { 183 184 /* 185 * We disallow any class registration past SI_ORDER_ANY 186 * of SI_SUB_KLD. We bump the reference count to keep the 187 * ops from being freed. 188 */ 189 if (linker_no_more_classes == 1) 190 return (EPERM); 191 kobj_class_compile((kobj_class_t) lc); 192 ((kobj_class_t)lc)->refs++; /* XXX: kobj_mtx */ 193 TAILQ_INSERT_TAIL(&classes, lc, link); 194 return (0); 195 } 196 197 static void 198 linker_file_sysinit(linker_file_t lf) 199 { 200 struct sysinit **start, **stop, **sipp, **xipp, *save; 201 202 KLD_DPF(FILE, ("linker_file_sysinit: calling SYSINITs for %s\n", 203 lf->filename)); 204 205 if (linker_file_lookup_set(lf, "sysinit_set", &start, &stop, NULL) != 0) 206 return; 207 /* 208 * Perform a bubble sort of the system initialization objects by 209 * their subsystem (primary key) and order (secondary key). 210 * 211 * Since some things care about execution order, this is the operation 212 * which ensures continued function. 213 */ 214 for (sipp = start; sipp < stop; sipp++) { 215 for (xipp = sipp + 1; xipp < stop; xipp++) { 216 if ((*sipp)->subsystem < (*xipp)->subsystem || 217 ((*sipp)->subsystem == (*xipp)->subsystem && 218 (*sipp)->order <= (*xipp)->order)) 219 continue; /* skip */ 220 save = *sipp; 221 *sipp = *xipp; 222 *xipp = save; 223 } 224 } 225 226 /* 227 * Traverse the (now) ordered list of system initialization tasks. 228 * Perform each task, and continue on to the next task. 229 */ 230 mtx_lock(&Giant); 231 for (sipp = start; sipp < stop; sipp++) { 232 if ((*sipp)->subsystem == SI_SUB_DUMMY) 233 continue; /* skip dummy task(s) */ 234 235 /* Call function */ 236 (*((*sipp)->func)) ((*sipp)->udata); 237 } 238 mtx_unlock(&Giant); 239 } 240 241 static void 242 linker_file_sysuninit(linker_file_t lf) 243 { 244 struct sysinit **start, **stop, **sipp, **xipp, *save; 245 246 KLD_DPF(FILE, ("linker_file_sysuninit: calling SYSUNINITs for %s\n", 247 lf->filename)); 248 249 if (linker_file_lookup_set(lf, "sysuninit_set", &start, &stop, 250 NULL) != 0) 251 return; 252 253 /* 254 * Perform a reverse bubble sort of the system initialization objects 255 * by their subsystem (primary key) and order (secondary key). 256 * 257 * Since some things care about execution order, this is the operation 258 * which ensures continued function. 259 */ 260 for (sipp = start; sipp < stop; sipp++) { 261 for (xipp = sipp + 1; xipp < stop; xipp++) { 262 if ((*sipp)->subsystem > (*xipp)->subsystem || 263 ((*sipp)->subsystem == (*xipp)->subsystem && 264 (*sipp)->order >= (*xipp)->order)) 265 continue; /* skip */ 266 save = *sipp; 267 *sipp = *xipp; 268 *xipp = save; 269 } 270 } 271 272 /* 273 * Traverse the (now) ordered list of system initialization tasks. 274 * Perform each task, and continue on to the next task. 275 */ 276 mtx_lock(&Giant); 277 for (sipp = start; sipp < stop; sipp++) { 278 if ((*sipp)->subsystem == SI_SUB_DUMMY) 279 continue; /* skip dummy task(s) */ 280 281 /* Call function */ 282 (*((*sipp)->func)) ((*sipp)->udata); 283 } 284 mtx_unlock(&Giant); 285 } 286 287 static void 288 linker_file_register_sysctls(linker_file_t lf) 289 { 290 struct sysctl_oid **start, **stop, **oidp; 291 292 KLD_DPF(FILE, 293 ("linker_file_register_sysctls: registering SYSCTLs for %s\n", 294 lf->filename)); 295 296 if (linker_file_lookup_set(lf, "sysctl_set", &start, &stop, NULL) != 0) 297 return; 298 299 sysctl_lock(); 300 for (oidp = start; oidp < stop; oidp++) 301 sysctl_register_oid(*oidp); 302 sysctl_unlock(); 303 } 304 305 static void 306 linker_file_unregister_sysctls(linker_file_t lf) 307 { 308 struct sysctl_oid **start, **stop, **oidp; 309 310 KLD_DPF(FILE, ("linker_file_unregister_sysctls: registering SYSCTLs" 311 " for %s\n", lf->filename)); 312 313 if (linker_file_lookup_set(lf, "sysctl_set", &start, &stop, NULL) != 0) 314 return; 315 316 sysctl_lock(); 317 for (oidp = start; oidp < stop; oidp++) 318 sysctl_unregister_oid(*oidp); 319 sysctl_unlock(); 320 } 321 322 static int 323 linker_file_register_modules(linker_file_t lf) 324 { 325 struct mod_metadata **start, **stop, **mdp; 326 const moduledata_t *moddata; 327 int first_error, error; 328 329 KLD_DPF(FILE, ("linker_file_register_modules: registering modules" 330 " in %s\n", lf->filename)); 331 332 if (linker_file_lookup_set(lf, "modmetadata_set", &start, 333 &stop, NULL) != 0) { 334 /* 335 * This fallback should be unnecessary, but if we get booted 336 * from boot2 instead of loader and we are missing our 337 * metadata then we have to try the best we can. 338 */ 339 if (lf == linker_kernel_file) { 340 start = SET_BEGIN(modmetadata_set); 341 stop = SET_LIMIT(modmetadata_set); 342 } else 343 return (0); 344 } 345 first_error = 0; 346 for (mdp = start; mdp < stop; mdp++) { 347 if ((*mdp)->md_type != MDT_MODULE) 348 continue; 349 moddata = (*mdp)->md_data; 350 KLD_DPF(FILE, ("Registering module %s in %s\n", 351 moddata->name, lf->filename)); 352 error = module_register(moddata, lf); 353 if (error) { 354 printf("Module %s failed to register: %d\n", 355 moddata->name, error); 356 if (first_error == 0) 357 first_error = error; 358 } 359 } 360 return (first_error); 361 } 362 363 static void 364 linker_init_kernel_modules(void) 365 { 366 367 linker_file_register_modules(linker_kernel_file); 368 } 369 370 SYSINIT(linker_kernel, SI_SUB_KLD, SI_ORDER_ANY, linker_init_kernel_modules, 371 0); 372 373 static int 374 linker_load_file(const char *filename, linker_file_t *result) 375 { 376 linker_class_t lc; 377 linker_file_t lf; 378 int foundfile, error; 379 380 /* Refuse to load modules if securelevel raised */ 381 if (prison0.pr_securelevel > 0) 382 return (EPERM); 383 384 KLD_LOCK_ASSERT(); 385 lf = linker_find_file_by_name(filename); 386 if (lf) { 387 KLD_DPF(FILE, ("linker_load_file: file %s is already loaded," 388 " incrementing refs\n", filename)); 389 *result = lf; 390 lf->refs++; 391 return (0); 392 } 393 foundfile = 0; 394 error = 0; 395 396 /* 397 * We do not need to protect (lock) classes here because there is 398 * no class registration past startup (SI_SUB_KLD, SI_ORDER_ANY) 399 * and there is no class deregistration mechanism at this time. 400 */ 401 TAILQ_FOREACH(lc, &classes, link) { 402 KLD_DPF(FILE, ("linker_load_file: trying to load %s\n", 403 filename)); 404 error = LINKER_LOAD_FILE(lc, filename, &lf); 405 /* 406 * If we got something other than ENOENT, then it exists but 407 * we cannot load it for some other reason. 408 */ 409 if (error != ENOENT) 410 foundfile = 1; 411 if (lf) { 412 error = linker_file_register_modules(lf); 413 if (error == EEXIST) { 414 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 415 return (error); 416 } 417 KLD_UNLOCK(); 418 linker_file_register_sysctls(lf); 419 linker_file_sysinit(lf); 420 KLD_LOCK(); 421 lf->flags |= LINKER_FILE_LINKED; 422 *result = lf; 423 return (0); 424 } 425 } 426 /* 427 * Less than ideal, but tells the user whether it failed to load or 428 * the module was not found. 429 */ 430 if (foundfile) { 431 432 /* 433 * If the file type has not been recognized by the last try 434 * printout a message before to fail. 435 */ 436 if (error == ENOSYS) 437 printf("linker_load_file: Unsupported file type\n"); 438 439 /* 440 * Format not recognized or otherwise unloadable. 441 * When loading a module that is statically built into 442 * the kernel EEXIST percolates back up as the return 443 * value. Preserve this so that apps like sysinstall 444 * can recognize this special case and not post bogus 445 * dialog boxes. 446 */ 447 if (error != EEXIST) 448 error = ENOEXEC; 449 } else 450 error = ENOENT; /* Nothing found */ 451 return (error); 452 } 453 454 int 455 linker_reference_module(const char *modname, struct mod_depend *verinfo, 456 linker_file_t *result) 457 { 458 modlist_t mod; 459 int error; 460 461 KLD_LOCK(); 462 if ((mod = modlist_lookup2(modname, verinfo)) != NULL) { 463 *result = mod->container; 464 (*result)->refs++; 465 KLD_UNLOCK(); 466 return (0); 467 } 468 469 error = linker_load_module(NULL, modname, NULL, verinfo, result); 470 KLD_UNLOCK(); 471 return (error); 472 } 473 474 int 475 linker_release_module(const char *modname, struct mod_depend *verinfo, 476 linker_file_t lf) 477 { 478 modlist_t mod; 479 int error; 480 481 KLD_LOCK(); 482 if (lf == NULL) { 483 KASSERT(modname != NULL, 484 ("linker_release_module: no file or name")); 485 mod = modlist_lookup2(modname, verinfo); 486 if (mod == NULL) { 487 KLD_UNLOCK(); 488 return (ESRCH); 489 } 490 lf = mod->container; 491 } else 492 KASSERT(modname == NULL && verinfo == NULL, 493 ("linker_release_module: both file and name")); 494 error = linker_file_unload(lf, LINKER_UNLOAD_NORMAL); 495 KLD_UNLOCK(); 496 return (error); 497 } 498 499 static linker_file_t 500 linker_find_file_by_name(const char *filename) 501 { 502 linker_file_t lf; 503 char *koname; 504 505 koname = malloc(strlen(filename) + 4, M_LINKER, M_WAITOK); 506 sprintf(koname, "%s.ko", filename); 507 508 KLD_LOCK_ASSERT(); 509 TAILQ_FOREACH(lf, &linker_files, link) { 510 if (strcmp(lf->filename, koname) == 0) 511 break; 512 if (strcmp(lf->filename, filename) == 0) 513 break; 514 } 515 free(koname, M_LINKER); 516 return (lf); 517 } 518 519 static linker_file_t 520 linker_find_file_by_id(int fileid) 521 { 522 linker_file_t lf; 523 524 KLD_LOCK_ASSERT(); 525 TAILQ_FOREACH(lf, &linker_files, link) 526 if (lf->id == fileid && lf->flags & LINKER_FILE_LINKED) 527 break; 528 return (lf); 529 } 530 531 int 532 linker_file_foreach(linker_predicate_t *predicate, void *context) 533 { 534 linker_file_t lf; 535 int retval = 0; 536 537 KLD_LOCK(); 538 TAILQ_FOREACH(lf, &linker_files, link) { 539 retval = predicate(lf, context); 540 if (retval != 0) 541 break; 542 } 543 KLD_UNLOCK(); 544 return (retval); 545 } 546 547 linker_file_t 548 linker_make_file(const char *pathname, linker_class_t lc) 549 { 550 linker_file_t lf; 551 const char *filename; 552 553 KLD_LOCK_ASSERT(); 554 filename = linker_basename(pathname); 555 556 KLD_DPF(FILE, ("linker_make_file: new file, filename='%s' for pathname='%s'\n", filename, pathname)); 557 lf = (linker_file_t)kobj_create((kobj_class_t)lc, M_LINKER, M_WAITOK); 558 if (lf == NULL) 559 return (NULL); 560 lf->refs = 1; 561 lf->userrefs = 0; 562 lf->flags = 0; 563 lf->filename = linker_strdup(filename); 564 lf->pathname = linker_strdup(pathname); 565 LINKER_GET_NEXT_FILE_ID(lf->id); 566 lf->ndeps = 0; 567 lf->deps = NULL; 568 lf->loadcnt = ++loadcnt; 569 lf->sdt_probes = NULL; 570 lf->sdt_nprobes = 0; 571 STAILQ_INIT(&lf->common); 572 TAILQ_INIT(&lf->modules); 573 TAILQ_INSERT_TAIL(&linker_files, lf, link); 574 return (lf); 575 } 576 577 int 578 linker_file_unload(linker_file_t file, int flags) 579 { 580 module_t mod, next; 581 modlist_t ml, nextml; 582 struct common_symbol *cp; 583 int error, i; 584 585 /* Refuse to unload modules if securelevel raised. */ 586 if (prison0.pr_securelevel > 0) 587 return (EPERM); 588 589 KLD_LOCK_ASSERT(); 590 KLD_DPF(FILE, ("linker_file_unload: lf->refs=%d\n", file->refs)); 591 592 /* Easy case of just dropping a reference. */ 593 if (file->refs > 1) { 594 file->refs--; 595 return (0); 596 } 597 598 KLD_DPF(FILE, ("linker_file_unload: file is unloading," 599 " informing modules\n")); 600 601 /* 602 * Quiesce all the modules to give them a chance to veto the unload. 603 */ 604 MOD_SLOCK; 605 for (mod = TAILQ_FIRST(&file->modules); mod; 606 mod = module_getfnext(mod)) { 607 608 error = module_quiesce(mod); 609 if (error != 0 && flags != LINKER_UNLOAD_FORCE) { 610 KLD_DPF(FILE, ("linker_file_unload: module %s" 611 " vetoed unload\n", module_getname(mod))); 612 /* 613 * XXX: Do we need to tell all the quiesced modules 614 * that they can resume work now via a new module 615 * event? 616 */ 617 MOD_SUNLOCK; 618 return (error); 619 } 620 } 621 MOD_SUNLOCK; 622 623 /* 624 * Inform any modules associated with this file that they are 625 * being be unloaded. 626 */ 627 MOD_XLOCK; 628 for (mod = TAILQ_FIRST(&file->modules); mod; mod = next) { 629 next = module_getfnext(mod); 630 MOD_XUNLOCK; 631 632 /* 633 * Give the module a chance to veto the unload. 634 */ 635 if ((error = module_unload(mod)) != 0) { 636 KLD_DPF(FILE, ("linker_file_unload: module %s" 637 " failed unload\n", module_getname(mod))); 638 return (error); 639 } 640 MOD_XLOCK; 641 module_release(mod); 642 } 643 MOD_XUNLOCK; 644 645 TAILQ_FOREACH_SAFE(ml, &found_modules, link, nextml) { 646 if (ml->container == file) { 647 TAILQ_REMOVE(&found_modules, ml, link); 648 free(ml, M_LINKER); 649 } 650 } 651 652 /* 653 * Don't try to run SYSUNINITs if we are unloaded due to a 654 * link error. 655 */ 656 if (file->flags & LINKER_FILE_LINKED) { 657 file->flags &= ~LINKER_FILE_LINKED; 658 KLD_UNLOCK(); 659 linker_file_sysuninit(file); 660 linker_file_unregister_sysctls(file); 661 KLD_LOCK(); 662 } 663 TAILQ_REMOVE(&linker_files, file, link); 664 665 if (file->deps) { 666 for (i = 0; i < file->ndeps; i++) 667 linker_file_unload(file->deps[i], flags); 668 free(file->deps, M_LINKER); 669 file->deps = NULL; 670 } 671 while ((cp = STAILQ_FIRST(&file->common)) != NULL) { 672 STAILQ_REMOVE_HEAD(&file->common, link); 673 free(cp, M_LINKER); 674 } 675 676 LINKER_UNLOAD(file); 677 if (file->filename) { 678 free(file->filename, M_LINKER); 679 file->filename = NULL; 680 } 681 if (file->pathname) { 682 free(file->pathname, M_LINKER); 683 file->pathname = NULL; 684 } 685 kobj_delete((kobj_t) file, M_LINKER); 686 return (0); 687 } 688 689 int 690 linker_ctf_get(linker_file_t file, linker_ctf_t *lc) 691 { 692 return (LINKER_CTF_GET(file, lc)); 693 } 694 695 static int 696 linker_file_add_dependency(linker_file_t file, linker_file_t dep) 697 { 698 linker_file_t *newdeps; 699 700 KLD_LOCK_ASSERT(); 701 newdeps = malloc((file->ndeps + 1) * sizeof(linker_file_t *), 702 M_LINKER, M_WAITOK | M_ZERO); 703 if (newdeps == NULL) 704 return (ENOMEM); 705 706 if (file->deps) { 707 bcopy(file->deps, newdeps, 708 file->ndeps * sizeof(linker_file_t *)); 709 free(file->deps, M_LINKER); 710 } 711 file->deps = newdeps; 712 file->deps[file->ndeps] = dep; 713 file->ndeps++; 714 KLD_DPF(FILE, ("linker_file_add_dependency:" 715 " adding %s as dependency for %s\n", 716 dep->filename, file->filename)); 717 return (0); 718 } 719 720 /* 721 * Locate a linker set and its contents. This is a helper function to avoid 722 * linker_if.h exposure elsewhere. Note: firstp and lastp are really void **. 723 * This function is used in this file so we can avoid having lots of (void **) 724 * casts. 725 */ 726 int 727 linker_file_lookup_set(linker_file_t file, const char *name, 728 void *firstp, void *lastp, int *countp) 729 { 730 int error, locked; 731 732 locked = KLD_LOCKED(); 733 if (!locked) 734 KLD_LOCK(); 735 error = LINKER_LOOKUP_SET(file, name, firstp, lastp, countp); 736 if (!locked) 737 KLD_UNLOCK(); 738 return (error); 739 } 740 741 /* 742 * List all functions in a file. 743 */ 744 int 745 linker_file_function_listall(linker_file_t lf, 746 linker_function_nameval_callback_t callback_func, void *arg) 747 { 748 return (LINKER_EACH_FUNCTION_NAMEVAL(lf, callback_func, arg)); 749 } 750 751 caddr_t 752 linker_file_lookup_symbol(linker_file_t file, const char *name, int deps) 753 { 754 caddr_t sym; 755 int locked; 756 757 locked = KLD_LOCKED(); 758 if (!locked) 759 KLD_LOCK(); 760 sym = linker_file_lookup_symbol_internal(file, name, deps); 761 if (!locked) 762 KLD_UNLOCK(); 763 return (sym); 764 } 765 766 static caddr_t 767 linker_file_lookup_symbol_internal(linker_file_t file, const char *name, 768 int deps) 769 { 770 c_linker_sym_t sym; 771 linker_symval_t symval; 772 caddr_t address; 773 size_t common_size = 0; 774 int i; 775 776 KLD_LOCK_ASSERT(); 777 KLD_DPF(SYM, ("linker_file_lookup_symbol: file=%p, name=%s, deps=%d\n", 778 file, name, deps)); 779 780 if (LINKER_LOOKUP_SYMBOL(file, name, &sym) == 0) { 781 LINKER_SYMBOL_VALUES(file, sym, &symval); 782 if (symval.value == 0) 783 /* 784 * For commons, first look them up in the 785 * dependencies and only allocate space if not found 786 * there. 787 */ 788 common_size = symval.size; 789 else { 790 KLD_DPF(SYM, ("linker_file_lookup_symbol: symbol" 791 ".value=%p\n", symval.value)); 792 return (symval.value); 793 } 794 } 795 if (deps) { 796 for (i = 0; i < file->ndeps; i++) { 797 address = linker_file_lookup_symbol_internal( 798 file->deps[i], name, 0); 799 if (address) { 800 KLD_DPF(SYM, ("linker_file_lookup_symbol:" 801 " deps value=%p\n", address)); 802 return (address); 803 } 804 } 805 } 806 if (common_size > 0) { 807 /* 808 * This is a common symbol which was not found in the 809 * dependencies. We maintain a simple common symbol table in 810 * the file object. 811 */ 812 struct common_symbol *cp; 813 814 STAILQ_FOREACH(cp, &file->common, link) { 815 if (strcmp(cp->name, name) == 0) { 816 KLD_DPF(SYM, ("linker_file_lookup_symbol:" 817 " old common value=%p\n", cp->address)); 818 return (cp->address); 819 } 820 } 821 /* 822 * Round the symbol size up to align. 823 */ 824 common_size = (common_size + sizeof(int) - 1) & -sizeof(int); 825 cp = malloc(sizeof(struct common_symbol) 826 + common_size + strlen(name) + 1, M_LINKER, 827 M_WAITOK | M_ZERO); 828 cp->address = (caddr_t)(cp + 1); 829 cp->name = cp->address + common_size; 830 strcpy(cp->name, name); 831 bzero(cp->address, common_size); 832 STAILQ_INSERT_TAIL(&file->common, cp, link); 833 834 KLD_DPF(SYM, ("linker_file_lookup_symbol: new common" 835 " value=%p\n", cp->address)); 836 return (cp->address); 837 } 838 KLD_DPF(SYM, ("linker_file_lookup_symbol: fail\n")); 839 return (0); 840 } 841 842 /* 843 * Both DDB and stack(9) rely on the kernel linker to provide forward and 844 * backward lookup of symbols. However, DDB and sometimes stack(9) need to 845 * do this in a lockfree manner. We provide a set of internal helper 846 * routines to perform these operations without locks, and then wrappers that 847 * optionally lock. 848 * 849 * linker_debug_lookup() is ifdef DDB as currently it's only used by DDB. 850 */ 851 #ifdef DDB 852 static int 853 linker_debug_lookup(const char *symstr, c_linker_sym_t *sym) 854 { 855 linker_file_t lf; 856 857 TAILQ_FOREACH(lf, &linker_files, link) { 858 if (LINKER_LOOKUP_SYMBOL(lf, symstr, sym) == 0) 859 return (0); 860 } 861 return (ENOENT); 862 } 863 #endif 864 865 static int 866 linker_debug_search_symbol(caddr_t value, c_linker_sym_t *sym, long *diffp) 867 { 868 linker_file_t lf; 869 c_linker_sym_t best, es; 870 u_long diff, bestdiff, off; 871 872 best = 0; 873 off = (uintptr_t)value; 874 bestdiff = off; 875 TAILQ_FOREACH(lf, &linker_files, link) { 876 if (LINKER_SEARCH_SYMBOL(lf, value, &es, &diff) != 0) 877 continue; 878 if (es != 0 && diff < bestdiff) { 879 best = es; 880 bestdiff = diff; 881 } 882 if (bestdiff == 0) 883 break; 884 } 885 if (best) { 886 *sym = best; 887 *diffp = bestdiff; 888 return (0); 889 } else { 890 *sym = 0; 891 *diffp = off; 892 return (ENOENT); 893 } 894 } 895 896 static int 897 linker_debug_symbol_values(c_linker_sym_t sym, linker_symval_t *symval) 898 { 899 linker_file_t lf; 900 901 TAILQ_FOREACH(lf, &linker_files, link) { 902 if (LINKER_SYMBOL_VALUES(lf, sym, symval) == 0) 903 return (0); 904 } 905 return (ENOENT); 906 } 907 908 static int 909 linker_debug_search_symbol_name(caddr_t value, char *buf, u_int buflen, 910 long *offset) 911 { 912 linker_symval_t symval; 913 c_linker_sym_t sym; 914 int error; 915 916 *offset = 0; 917 error = linker_debug_search_symbol(value, &sym, offset); 918 if (error) 919 return (error); 920 error = linker_debug_symbol_values(sym, &symval); 921 if (error) 922 return (error); 923 strlcpy(buf, symval.name, buflen); 924 return (0); 925 } 926 927 /* 928 * DDB Helpers. DDB has to look across multiple files with their own symbol 929 * tables and string tables. 930 * 931 * Note that we do not obey list locking protocols here. We really don't need 932 * DDB to hang because somebody's got the lock held. We'll take the chance 933 * that the files list is inconsistant instead. 934 */ 935 #ifdef DDB 936 int 937 linker_ddb_lookup(const char *symstr, c_linker_sym_t *sym) 938 { 939 940 return (linker_debug_lookup(symstr, sym)); 941 } 942 #endif 943 944 int 945 linker_ddb_search_symbol(caddr_t value, c_linker_sym_t *sym, long *diffp) 946 { 947 948 return (linker_debug_search_symbol(value, sym, diffp)); 949 } 950 951 int 952 linker_ddb_symbol_values(c_linker_sym_t sym, linker_symval_t *symval) 953 { 954 955 return (linker_debug_symbol_values(sym, symval)); 956 } 957 958 int 959 linker_ddb_search_symbol_name(caddr_t value, char *buf, u_int buflen, 960 long *offset) 961 { 962 963 return (linker_debug_search_symbol_name(value, buf, buflen, offset)); 964 } 965 966 /* 967 * stack(9) helper for non-debugging environemnts. Unlike DDB helpers, we do 968 * obey locking protocols, and offer a significantly less complex interface. 969 */ 970 int 971 linker_search_symbol_name(caddr_t value, char *buf, u_int buflen, 972 long *offset) 973 { 974 int error; 975 976 KLD_LOCK(); 977 error = linker_debug_search_symbol_name(value, buf, buflen, offset); 978 KLD_UNLOCK(); 979 return (error); 980 } 981 982 /* 983 * Syscalls. 984 */ 985 int 986 kern_kldload(struct thread *td, const char *file, int *fileid) 987 { 988 #ifdef HWPMC_HOOKS 989 struct pmckern_map_in pkm; 990 #endif 991 const char *kldname, *modname; 992 linker_file_t lf; 993 int error; 994 995 if ((error = securelevel_gt(td->td_ucred, 0)) != 0) 996 return (error); 997 998 if ((error = priv_check(td, PRIV_KLD_LOAD)) != 0) 999 return (error); 1000 1001 /* 1002 * It is possible that kldloaded module will attach a new ifnet, 1003 * so vnet context must be set when this ocurs. 1004 */ 1005 CURVNET_SET(TD_TO_VNET(td)); 1006 1007 /* 1008 * If file does not contain a qualified name or any dot in it 1009 * (kldname.ko, or kldname.ver.ko) treat it as an interface 1010 * name. 1011 */ 1012 if (index(file, '/') || index(file, '.')) { 1013 kldname = file; 1014 modname = NULL; 1015 } else { 1016 kldname = NULL; 1017 modname = file; 1018 } 1019 1020 KLD_LOCK(); 1021 error = linker_load_module(kldname, modname, NULL, NULL, &lf); 1022 if (error) 1023 goto unlock; 1024 #ifdef HWPMC_HOOKS 1025 pkm.pm_file = lf->filename; 1026 pkm.pm_address = (uintptr_t) lf->address; 1027 PMC_CALL_HOOK(td, PMC_FN_KLD_LOAD, (void *) &pkm); 1028 #endif 1029 lf->userrefs++; 1030 if (fileid != NULL) 1031 *fileid = lf->id; 1032 unlock: 1033 KLD_UNLOCK(); 1034 CURVNET_RESTORE(); 1035 return (error); 1036 } 1037 1038 int 1039 kldload(struct thread *td, struct kldload_args *uap) 1040 { 1041 char *pathname = NULL; 1042 int error, fileid; 1043 1044 td->td_retval[0] = -1; 1045 1046 pathname = malloc(MAXPATHLEN, M_TEMP, M_WAITOK); 1047 error = copyinstr(uap->file, pathname, MAXPATHLEN, NULL); 1048 if (error == 0) { 1049 error = kern_kldload(td, pathname, &fileid); 1050 if (error == 0) 1051 td->td_retval[0] = fileid; 1052 } 1053 free(pathname, M_TEMP); 1054 return (error); 1055 } 1056 1057 int 1058 kern_kldunload(struct thread *td, int fileid, int flags) 1059 { 1060 #ifdef HWPMC_HOOKS 1061 struct pmckern_map_out pkm; 1062 #endif 1063 linker_file_t lf; 1064 int error = 0; 1065 1066 if ((error = securelevel_gt(td->td_ucred, 0)) != 0) 1067 return (error); 1068 1069 if ((error = priv_check(td, PRIV_KLD_UNLOAD)) != 0) 1070 return (error); 1071 1072 CURVNET_SET(TD_TO_VNET(td)); 1073 KLD_LOCK(); 1074 lf = linker_find_file_by_id(fileid); 1075 if (lf) { 1076 KLD_DPF(FILE, ("kldunload: lf->userrefs=%d\n", lf->userrefs)); 1077 1078 /* Check if there are DTrace probes enabled on this file. */ 1079 if (lf->nenabled > 0) { 1080 printf("kldunload: attempt to unload file that has" 1081 " DTrace probes enabled\n"); 1082 error = EBUSY; 1083 } else if (lf->userrefs == 0) { 1084 /* 1085 * XXX: maybe LINKER_UNLOAD_FORCE should override ? 1086 */ 1087 printf("kldunload: attempt to unload file that was" 1088 " loaded by the kernel\n"); 1089 error = EBUSY; 1090 } else { 1091 #ifdef HWPMC_HOOKS 1092 /* Save data needed by hwpmc(4) before unloading. */ 1093 pkm.pm_address = (uintptr_t) lf->address; 1094 pkm.pm_size = lf->size; 1095 #endif 1096 lf->userrefs--; 1097 error = linker_file_unload(lf, flags); 1098 if (error) 1099 lf->userrefs++; 1100 } 1101 } else 1102 error = ENOENT; 1103 1104 #ifdef HWPMC_HOOKS 1105 if (error == 0) 1106 PMC_CALL_HOOK(td, PMC_FN_KLD_UNLOAD, (void *) &pkm); 1107 #endif 1108 KLD_UNLOCK(); 1109 CURVNET_RESTORE(); 1110 return (error); 1111 } 1112 1113 int 1114 kldunload(struct thread *td, struct kldunload_args *uap) 1115 { 1116 1117 return (kern_kldunload(td, uap->fileid, LINKER_UNLOAD_NORMAL)); 1118 } 1119 1120 int 1121 kldunloadf(struct thread *td, struct kldunloadf_args *uap) 1122 { 1123 1124 if (uap->flags != LINKER_UNLOAD_NORMAL && 1125 uap->flags != LINKER_UNLOAD_FORCE) 1126 return (EINVAL); 1127 return (kern_kldunload(td, uap->fileid, uap->flags)); 1128 } 1129 1130 int 1131 kldfind(struct thread *td, struct kldfind_args *uap) 1132 { 1133 char *pathname; 1134 const char *filename; 1135 linker_file_t lf; 1136 int error; 1137 1138 #ifdef MAC 1139 error = mac_kld_check_stat(td->td_ucred); 1140 if (error) 1141 return (error); 1142 #endif 1143 1144 td->td_retval[0] = -1; 1145 1146 pathname = malloc(MAXPATHLEN, M_TEMP, M_WAITOK); 1147 if ((error = copyinstr(uap->file, pathname, MAXPATHLEN, NULL)) != 0) 1148 goto out; 1149 1150 filename = linker_basename(pathname); 1151 KLD_LOCK(); 1152 lf = linker_find_file_by_name(filename); 1153 if (lf) 1154 td->td_retval[0] = lf->id; 1155 else 1156 error = ENOENT; 1157 KLD_UNLOCK(); 1158 out: 1159 free(pathname, M_TEMP); 1160 return (error); 1161 } 1162 1163 int 1164 kldnext(struct thread *td, struct kldnext_args *uap) 1165 { 1166 linker_file_t lf; 1167 int error = 0; 1168 1169 #ifdef MAC 1170 error = mac_kld_check_stat(td->td_ucred); 1171 if (error) 1172 return (error); 1173 #endif 1174 1175 KLD_LOCK(); 1176 if (uap->fileid == 0) 1177 lf = TAILQ_FIRST(&linker_files); 1178 else { 1179 lf = linker_find_file_by_id(uap->fileid); 1180 if (lf == NULL) { 1181 error = ENOENT; 1182 goto out; 1183 } 1184 lf = TAILQ_NEXT(lf, link); 1185 } 1186 1187 /* Skip partially loaded files. */ 1188 while (lf != NULL && !(lf->flags & LINKER_FILE_LINKED)) 1189 lf = TAILQ_NEXT(lf, link); 1190 1191 if (lf) 1192 td->td_retval[0] = lf->id; 1193 else 1194 td->td_retval[0] = 0; 1195 out: 1196 KLD_UNLOCK(); 1197 return (error); 1198 } 1199 1200 int 1201 kldstat(struct thread *td, struct kldstat_args *uap) 1202 { 1203 struct kld_file_stat stat; 1204 int error, version; 1205 1206 /* 1207 * Check the version of the user's structure. 1208 */ 1209 if ((error = copyin(&uap->stat->version, &version, sizeof(version))) 1210 != 0) 1211 return (error); 1212 if (version != sizeof(struct kld_file_stat_1) && 1213 version != sizeof(struct kld_file_stat)) 1214 return (EINVAL); 1215 1216 error = kern_kldstat(td, uap->fileid, &stat); 1217 if (error != 0) 1218 return (error); 1219 return (copyout(&stat, uap->stat, version)); 1220 } 1221 1222 int 1223 kern_kldstat(struct thread *td, int fileid, struct kld_file_stat *stat) 1224 { 1225 linker_file_t lf; 1226 int namelen; 1227 #ifdef MAC 1228 int error; 1229 1230 error = mac_kld_check_stat(td->td_ucred); 1231 if (error) 1232 return (error); 1233 #endif 1234 1235 KLD_LOCK(); 1236 lf = linker_find_file_by_id(fileid); 1237 if (lf == NULL) { 1238 KLD_UNLOCK(); 1239 return (ENOENT); 1240 } 1241 1242 /* Version 1 fields: */ 1243 namelen = strlen(lf->filename) + 1; 1244 if (namelen > MAXPATHLEN) 1245 namelen = MAXPATHLEN; 1246 bcopy(lf->filename, &stat->name[0], namelen); 1247 stat->refs = lf->refs; 1248 stat->id = lf->id; 1249 stat->address = lf->address; 1250 stat->size = lf->size; 1251 /* Version 2 fields: */ 1252 namelen = strlen(lf->pathname) + 1; 1253 if (namelen > MAXPATHLEN) 1254 namelen = MAXPATHLEN; 1255 bcopy(lf->pathname, &stat->pathname[0], namelen); 1256 KLD_UNLOCK(); 1257 1258 td->td_retval[0] = 0; 1259 return (0); 1260 } 1261 1262 int 1263 kldfirstmod(struct thread *td, struct kldfirstmod_args *uap) 1264 { 1265 linker_file_t lf; 1266 module_t mp; 1267 int error = 0; 1268 1269 #ifdef MAC 1270 error = mac_kld_check_stat(td->td_ucred); 1271 if (error) 1272 return (error); 1273 #endif 1274 1275 KLD_LOCK(); 1276 lf = linker_find_file_by_id(uap->fileid); 1277 if (lf) { 1278 MOD_SLOCK; 1279 mp = TAILQ_FIRST(&lf->modules); 1280 if (mp != NULL) 1281 td->td_retval[0] = module_getid(mp); 1282 else 1283 td->td_retval[0] = 0; 1284 MOD_SUNLOCK; 1285 } else 1286 error = ENOENT; 1287 KLD_UNLOCK(); 1288 return (error); 1289 } 1290 1291 int 1292 kldsym(struct thread *td, struct kldsym_args *uap) 1293 { 1294 char *symstr = NULL; 1295 c_linker_sym_t sym; 1296 linker_symval_t symval; 1297 linker_file_t lf; 1298 struct kld_sym_lookup lookup; 1299 int error = 0; 1300 1301 #ifdef MAC 1302 error = mac_kld_check_stat(td->td_ucred); 1303 if (error) 1304 return (error); 1305 #endif 1306 1307 if ((error = copyin(uap->data, &lookup, sizeof(lookup))) != 0) 1308 return (error); 1309 if (lookup.version != sizeof(lookup) || 1310 uap->cmd != KLDSYM_LOOKUP) 1311 return (EINVAL); 1312 symstr = malloc(MAXPATHLEN, M_TEMP, M_WAITOK); 1313 if ((error = copyinstr(lookup.symname, symstr, MAXPATHLEN, NULL)) != 0) 1314 goto out; 1315 KLD_LOCK(); 1316 if (uap->fileid != 0) { 1317 lf = linker_find_file_by_id(uap->fileid); 1318 if (lf == NULL) 1319 error = ENOENT; 1320 else if (LINKER_LOOKUP_SYMBOL(lf, symstr, &sym) == 0 && 1321 LINKER_SYMBOL_VALUES(lf, sym, &symval) == 0) { 1322 lookup.symvalue = (uintptr_t) symval.value; 1323 lookup.symsize = symval.size; 1324 error = copyout(&lookup, uap->data, sizeof(lookup)); 1325 } else 1326 error = ENOENT; 1327 } else { 1328 TAILQ_FOREACH(lf, &linker_files, link) { 1329 if (LINKER_LOOKUP_SYMBOL(lf, symstr, &sym) == 0 && 1330 LINKER_SYMBOL_VALUES(lf, sym, &symval) == 0) { 1331 lookup.symvalue = (uintptr_t)symval.value; 1332 lookup.symsize = symval.size; 1333 error = copyout(&lookup, uap->data, 1334 sizeof(lookup)); 1335 break; 1336 } 1337 } 1338 if (lf == NULL) 1339 error = ENOENT; 1340 } 1341 KLD_UNLOCK(); 1342 out: 1343 free(symstr, M_TEMP); 1344 return (error); 1345 } 1346 1347 /* 1348 * Preloaded module support 1349 */ 1350 1351 static modlist_t 1352 modlist_lookup(const char *name, int ver) 1353 { 1354 modlist_t mod; 1355 1356 TAILQ_FOREACH(mod, &found_modules, link) { 1357 if (strcmp(mod->name, name) == 0 && 1358 (ver == 0 || mod->version == ver)) 1359 return (mod); 1360 } 1361 return (NULL); 1362 } 1363 1364 static modlist_t 1365 modlist_lookup2(const char *name, struct mod_depend *verinfo) 1366 { 1367 modlist_t mod, bestmod; 1368 int ver; 1369 1370 if (verinfo == NULL) 1371 return (modlist_lookup(name, 0)); 1372 bestmod = NULL; 1373 TAILQ_FOREACH(mod, &found_modules, link) { 1374 if (strcmp(mod->name, name) != 0) 1375 continue; 1376 ver = mod->version; 1377 if (ver == verinfo->md_ver_preferred) 1378 return (mod); 1379 if (ver >= verinfo->md_ver_minimum && 1380 ver <= verinfo->md_ver_maximum && 1381 (bestmod == NULL || ver > bestmod->version)) 1382 bestmod = mod; 1383 } 1384 return (bestmod); 1385 } 1386 1387 static modlist_t 1388 modlist_newmodule(const char *modname, int version, linker_file_t container) 1389 { 1390 modlist_t mod; 1391 1392 mod = malloc(sizeof(struct modlist), M_LINKER, M_NOWAIT | M_ZERO); 1393 if (mod == NULL) 1394 panic("no memory for module list"); 1395 mod->container = container; 1396 mod->name = modname; 1397 mod->version = version; 1398 TAILQ_INSERT_TAIL(&found_modules, mod, link); 1399 return (mod); 1400 } 1401 1402 static void 1403 linker_addmodules(linker_file_t lf, struct mod_metadata **start, 1404 struct mod_metadata **stop, int preload) 1405 { 1406 struct mod_metadata *mp, **mdp; 1407 const char *modname; 1408 int ver; 1409 1410 for (mdp = start; mdp < stop; mdp++) { 1411 mp = *mdp; 1412 if (mp->md_type != MDT_VERSION) 1413 continue; 1414 modname = mp->md_cval; 1415 ver = ((struct mod_version *)mp->md_data)->mv_version; 1416 if (modlist_lookup(modname, ver) != NULL) { 1417 printf("module %s already present!\n", modname); 1418 /* XXX what can we do? this is a build error. :-( */ 1419 continue; 1420 } 1421 modlist_newmodule(modname, ver, lf); 1422 } 1423 } 1424 1425 static void 1426 linker_preload(void *arg) 1427 { 1428 caddr_t modptr; 1429 const char *modname, *nmodname; 1430 char *modtype; 1431 linker_file_t lf, nlf; 1432 linker_class_t lc; 1433 int error; 1434 linker_file_list_t loaded_files; 1435 linker_file_list_t depended_files; 1436 struct mod_metadata *mp, *nmp; 1437 struct mod_metadata **start, **stop, **mdp, **nmdp; 1438 struct mod_depend *verinfo; 1439 int nver; 1440 int resolves; 1441 modlist_t mod; 1442 struct sysinit **si_start, **si_stop; 1443 1444 TAILQ_INIT(&loaded_files); 1445 TAILQ_INIT(&depended_files); 1446 TAILQ_INIT(&found_modules); 1447 error = 0; 1448 1449 modptr = NULL; 1450 while ((modptr = preload_search_next_name(modptr)) != NULL) { 1451 modname = (char *)preload_search_info(modptr, MODINFO_NAME); 1452 modtype = (char *)preload_search_info(modptr, MODINFO_TYPE); 1453 if (modname == NULL) { 1454 printf("Preloaded module at %p does not have a" 1455 " name!\n", modptr); 1456 continue; 1457 } 1458 if (modtype == NULL) { 1459 printf("Preloaded module at %p does not have a type!\n", 1460 modptr); 1461 continue; 1462 } 1463 if (bootverbose) 1464 printf("Preloaded %s \"%s\" at %p.\n", modtype, modname, 1465 modptr); 1466 lf = NULL; 1467 TAILQ_FOREACH(lc, &classes, link) { 1468 error = LINKER_LINK_PRELOAD(lc, modname, &lf); 1469 if (!error) 1470 break; 1471 lf = NULL; 1472 } 1473 if (lf) 1474 TAILQ_INSERT_TAIL(&loaded_files, lf, loaded); 1475 } 1476 1477 /* 1478 * First get a list of stuff in the kernel. 1479 */ 1480 if (linker_file_lookup_set(linker_kernel_file, MDT_SETNAME, &start, 1481 &stop, NULL) == 0) 1482 linker_addmodules(linker_kernel_file, start, stop, 1); 1483 1484 /* 1485 * This is a once-off kinky bubble sort to resolve relocation 1486 * dependency requirements. 1487 */ 1488 restart: 1489 TAILQ_FOREACH(lf, &loaded_files, loaded) { 1490 error = linker_file_lookup_set(lf, MDT_SETNAME, &start, 1491 &stop, NULL); 1492 /* 1493 * First, look to see if we would successfully link with this 1494 * stuff. 1495 */ 1496 resolves = 1; /* unless we know otherwise */ 1497 if (!error) { 1498 for (mdp = start; mdp < stop; mdp++) { 1499 mp = *mdp; 1500 if (mp->md_type != MDT_DEPEND) 1501 continue; 1502 modname = mp->md_cval; 1503 verinfo = mp->md_data; 1504 for (nmdp = start; nmdp < stop; nmdp++) { 1505 nmp = *nmdp; 1506 if (nmp->md_type != MDT_VERSION) 1507 continue; 1508 nmodname = nmp->md_cval; 1509 if (strcmp(modname, nmodname) == 0) 1510 break; 1511 } 1512 if (nmdp < stop) /* it's a self reference */ 1513 continue; 1514 1515 /* 1516 * ok, the module isn't here yet, we 1517 * are not finished 1518 */ 1519 if (modlist_lookup2(modname, verinfo) == NULL) 1520 resolves = 0; 1521 } 1522 } 1523 /* 1524 * OK, if we found our modules, we can link. So, "provide" 1525 * the modules inside and add it to the end of the link order 1526 * list. 1527 */ 1528 if (resolves) { 1529 if (!error) { 1530 for (mdp = start; mdp < stop; mdp++) { 1531 mp = *mdp; 1532 if (mp->md_type != MDT_VERSION) 1533 continue; 1534 modname = mp->md_cval; 1535 nver = ((struct mod_version *) 1536 mp->md_data)->mv_version; 1537 if (modlist_lookup(modname, 1538 nver) != NULL) { 1539 printf("module %s already" 1540 " present!\n", modname); 1541 TAILQ_REMOVE(&loaded_files, 1542 lf, loaded); 1543 linker_file_unload(lf, 1544 LINKER_UNLOAD_FORCE); 1545 /* we changed tailq next ptr */ 1546 goto restart; 1547 } 1548 modlist_newmodule(modname, nver, lf); 1549 } 1550 } 1551 TAILQ_REMOVE(&loaded_files, lf, loaded); 1552 TAILQ_INSERT_TAIL(&depended_files, lf, loaded); 1553 /* 1554 * Since we provided modules, we need to restart the 1555 * sort so that the previous files that depend on us 1556 * have a chance. Also, we've busted the tailq next 1557 * pointer with the REMOVE. 1558 */ 1559 goto restart; 1560 } 1561 } 1562 1563 /* 1564 * At this point, we check to see what could not be resolved.. 1565 */ 1566 while ((lf = TAILQ_FIRST(&loaded_files)) != NULL) { 1567 TAILQ_REMOVE(&loaded_files, lf, loaded); 1568 printf("KLD file %s is missing dependencies\n", lf->filename); 1569 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 1570 } 1571 1572 /* 1573 * We made it. Finish off the linking in the order we determined. 1574 */ 1575 TAILQ_FOREACH_SAFE(lf, &depended_files, loaded, nlf) { 1576 if (linker_kernel_file) { 1577 linker_kernel_file->refs++; 1578 error = linker_file_add_dependency(lf, 1579 linker_kernel_file); 1580 if (error) 1581 panic("cannot add dependency"); 1582 } 1583 lf->userrefs++; /* so we can (try to) kldunload it */ 1584 error = linker_file_lookup_set(lf, MDT_SETNAME, &start, 1585 &stop, NULL); 1586 if (!error) { 1587 for (mdp = start; mdp < stop; mdp++) { 1588 mp = *mdp; 1589 if (mp->md_type != MDT_DEPEND) 1590 continue; 1591 modname = mp->md_cval; 1592 verinfo = mp->md_data; 1593 mod = modlist_lookup2(modname, verinfo); 1594 if (mod == NULL) { 1595 printf("KLD file %s - cannot find " 1596 "dependency \"%s\"\n", 1597 lf->filename, modname); 1598 goto fail; 1599 } 1600 /* Don't count self-dependencies */ 1601 if (lf == mod->container) 1602 continue; 1603 mod->container->refs++; 1604 error = linker_file_add_dependency(lf, 1605 mod->container); 1606 if (error) 1607 panic("cannot add dependency"); 1608 } 1609 } 1610 /* 1611 * Now do relocation etc using the symbol search paths 1612 * established by the dependencies 1613 */ 1614 error = LINKER_LINK_PRELOAD_FINISH(lf); 1615 if (error) { 1616 printf("KLD file %s - could not finalize loading\n", 1617 lf->filename); 1618 goto fail; 1619 } 1620 linker_file_register_modules(lf); 1621 if (linker_file_lookup_set(lf, "sysinit_set", &si_start, 1622 &si_stop, NULL) == 0) 1623 sysinit_add(si_start, si_stop); 1624 linker_file_register_sysctls(lf); 1625 lf->flags |= LINKER_FILE_LINKED; 1626 continue; 1627 fail: 1628 TAILQ_REMOVE(&depended_files, lf, loaded); 1629 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 1630 } 1631 /* woohoo! we made it! */ 1632 } 1633 1634 SYSINIT(preload, SI_SUB_KLD, SI_ORDER_MIDDLE, linker_preload, 0); 1635 1636 /* 1637 * Search for a not-loaded module by name. 1638 * 1639 * Modules may be found in the following locations: 1640 * 1641 * - preloaded (result is just the module name) - on disk (result is full path 1642 * to module) 1643 * 1644 * If the module name is qualified in any way (contains path, etc.) the we 1645 * simply return a copy of it. 1646 * 1647 * The search path can be manipulated via sysctl. Note that we use the ';' 1648 * character as a separator to be consistent with the bootloader. 1649 */ 1650 1651 static char linker_hintfile[] = "linker.hints"; 1652 static char linker_path[MAXPATHLEN] = "/boot/kernel;/boot/modules"; 1653 1654 SYSCTL_STRING(_kern, OID_AUTO, module_path, CTLFLAG_RW, linker_path, 1655 sizeof(linker_path), "module load search path"); 1656 1657 TUNABLE_STR("module_path", linker_path, sizeof(linker_path)); 1658 1659 static char *linker_ext_list[] = { 1660 "", 1661 ".ko", 1662 NULL 1663 }; 1664 1665 /* 1666 * Check if file actually exists either with or without extension listed in 1667 * the linker_ext_list. (probably should be generic for the rest of the 1668 * kernel) 1669 */ 1670 static char * 1671 linker_lookup_file(const char *path, int pathlen, const char *name, 1672 int namelen, struct vattr *vap) 1673 { 1674 struct nameidata nd; 1675 struct thread *td = curthread; /* XXX */ 1676 char *result, **cpp, *sep; 1677 int error, len, extlen, reclen, flags, vfslocked; 1678 enum vtype type; 1679 1680 extlen = 0; 1681 for (cpp = linker_ext_list; *cpp; cpp++) { 1682 len = strlen(*cpp); 1683 if (len > extlen) 1684 extlen = len; 1685 } 1686 extlen++; /* trailing '\0' */ 1687 sep = (path[pathlen - 1] != '/') ? "/" : ""; 1688 1689 reclen = pathlen + strlen(sep) + namelen + extlen + 1; 1690 result = malloc(reclen, M_LINKER, M_WAITOK); 1691 for (cpp = linker_ext_list; *cpp; cpp++) { 1692 snprintf(result, reclen, "%.*s%s%.*s%s", pathlen, path, sep, 1693 namelen, name, *cpp); 1694 /* 1695 * Attempt to open the file, and return the path if 1696 * we succeed and it's a regular file. 1697 */ 1698 NDINIT(&nd, LOOKUP, FOLLOW | MPSAFE, UIO_SYSSPACE, result, td); 1699 flags = FREAD; 1700 error = vn_open(&nd, &flags, 0, NULL); 1701 if (error == 0) { 1702 vfslocked = NDHASGIANT(&nd); 1703 NDFREE(&nd, NDF_ONLY_PNBUF); 1704 type = nd.ni_vp->v_type; 1705 if (vap) 1706 VOP_GETATTR(nd.ni_vp, vap, td->td_ucred); 1707 VOP_UNLOCK(nd.ni_vp, 0); 1708 vn_close(nd.ni_vp, FREAD, td->td_ucred, td); 1709 VFS_UNLOCK_GIANT(vfslocked); 1710 if (type == VREG) 1711 return (result); 1712 } 1713 } 1714 free(result, M_LINKER); 1715 return (NULL); 1716 } 1717 1718 #define INT_ALIGN(base, ptr) ptr = \ 1719 (base) + (((ptr) - (base) + sizeof(int) - 1) & ~(sizeof(int) - 1)) 1720 1721 /* 1722 * Lookup KLD which contains requested module in the "linker.hints" file. If 1723 * version specification is available, then try to find the best KLD. 1724 * Otherwise just find the latest one. 1725 */ 1726 static char * 1727 linker_hints_lookup(const char *path, int pathlen, const char *modname, 1728 int modnamelen, struct mod_depend *verinfo) 1729 { 1730 struct thread *td = curthread; /* XXX */ 1731 struct ucred *cred = td ? td->td_ucred : NULL; 1732 struct nameidata nd; 1733 struct vattr vattr, mattr; 1734 u_char *hints = NULL; 1735 u_char *cp, *recptr, *bufend, *result, *best, *pathbuf, *sep; 1736 int error, ival, bestver, *intp, reclen, found, flags, clen, blen; 1737 int vfslocked = 0; 1738 1739 result = NULL; 1740 bestver = found = 0; 1741 1742 sep = (path[pathlen - 1] != '/') ? "/" : ""; 1743 reclen = imax(modnamelen, strlen(linker_hintfile)) + pathlen + 1744 strlen(sep) + 1; 1745 pathbuf = malloc(reclen, M_LINKER, M_WAITOK); 1746 snprintf(pathbuf, reclen, "%.*s%s%s", pathlen, path, sep, 1747 linker_hintfile); 1748 1749 NDINIT(&nd, LOOKUP, NOFOLLOW | MPSAFE, UIO_SYSSPACE, pathbuf, td); 1750 flags = FREAD; 1751 error = vn_open(&nd, &flags, 0, NULL); 1752 if (error) 1753 goto bad; 1754 vfslocked = NDHASGIANT(&nd); 1755 NDFREE(&nd, NDF_ONLY_PNBUF); 1756 if (nd.ni_vp->v_type != VREG) 1757 goto bad; 1758 best = cp = NULL; 1759 error = VOP_GETATTR(nd.ni_vp, &vattr, cred); 1760 if (error) 1761 goto bad; 1762 /* 1763 * XXX: we need to limit this number to some reasonable value 1764 */ 1765 if (vattr.va_size > 100 * 1024) { 1766 printf("hints file too large %ld\n", (long)vattr.va_size); 1767 goto bad; 1768 } 1769 hints = malloc(vattr.va_size, M_TEMP, M_WAITOK); 1770 if (hints == NULL) 1771 goto bad; 1772 error = vn_rdwr(UIO_READ, nd.ni_vp, (caddr_t)hints, vattr.va_size, 0, 1773 UIO_SYSSPACE, IO_NODELOCKED, cred, NOCRED, &reclen, td); 1774 if (error) 1775 goto bad; 1776 VOP_UNLOCK(nd.ni_vp, 0); 1777 vn_close(nd.ni_vp, FREAD, cred, td); 1778 VFS_UNLOCK_GIANT(vfslocked); 1779 nd.ni_vp = NULL; 1780 if (reclen != 0) { 1781 printf("can't read %d\n", reclen); 1782 goto bad; 1783 } 1784 intp = (int *)hints; 1785 ival = *intp++; 1786 if (ival != LINKER_HINTS_VERSION) { 1787 printf("hints file version mismatch %d\n", ival); 1788 goto bad; 1789 } 1790 bufend = hints + vattr.va_size; 1791 recptr = (u_char *)intp; 1792 clen = blen = 0; 1793 while (recptr < bufend && !found) { 1794 intp = (int *)recptr; 1795 reclen = *intp++; 1796 ival = *intp++; 1797 cp = (char *)intp; 1798 switch (ival) { 1799 case MDT_VERSION: 1800 clen = *cp++; 1801 if (clen != modnamelen || bcmp(cp, modname, clen) != 0) 1802 break; 1803 cp += clen; 1804 INT_ALIGN(hints, cp); 1805 ival = *(int *)cp; 1806 cp += sizeof(int); 1807 clen = *cp++; 1808 if (verinfo == NULL || 1809 ival == verinfo->md_ver_preferred) { 1810 found = 1; 1811 break; 1812 } 1813 if (ival >= verinfo->md_ver_minimum && 1814 ival <= verinfo->md_ver_maximum && 1815 ival > bestver) { 1816 bestver = ival; 1817 best = cp; 1818 blen = clen; 1819 } 1820 break; 1821 default: 1822 break; 1823 } 1824 recptr += reclen + sizeof(int); 1825 } 1826 /* 1827 * Finally check if KLD is in the place 1828 */ 1829 if (found) 1830 result = linker_lookup_file(path, pathlen, cp, clen, &mattr); 1831 else if (best) 1832 result = linker_lookup_file(path, pathlen, best, blen, &mattr); 1833 1834 /* 1835 * KLD is newer than hints file. What we should do now? 1836 */ 1837 if (result && timespeccmp(&mattr.va_mtime, &vattr.va_mtime, >)) 1838 printf("warning: KLD '%s' is newer than the linker.hints" 1839 " file\n", result); 1840 bad: 1841 free(pathbuf, M_LINKER); 1842 if (hints) 1843 free(hints, M_TEMP); 1844 if (nd.ni_vp != NULL) { 1845 VOP_UNLOCK(nd.ni_vp, 0); 1846 vn_close(nd.ni_vp, FREAD, cred, td); 1847 VFS_UNLOCK_GIANT(vfslocked); 1848 } 1849 /* 1850 * If nothing found or hints is absent - fallback to the old 1851 * way by using "kldname[.ko]" as module name. 1852 */ 1853 if (!found && !bestver && result == NULL) 1854 result = linker_lookup_file(path, pathlen, modname, 1855 modnamelen, NULL); 1856 return (result); 1857 } 1858 1859 /* 1860 * Lookup KLD which contains requested module in the all directories. 1861 */ 1862 static char * 1863 linker_search_module(const char *modname, int modnamelen, 1864 struct mod_depend *verinfo) 1865 { 1866 char *cp, *ep, *result; 1867 1868 /* 1869 * traverse the linker path 1870 */ 1871 for (cp = linker_path; *cp; cp = ep + 1) { 1872 /* find the end of this component */ 1873 for (ep = cp; (*ep != 0) && (*ep != ';'); ep++); 1874 result = linker_hints_lookup(cp, ep - cp, modname, 1875 modnamelen, verinfo); 1876 if (result != NULL) 1877 return (result); 1878 if (*ep == 0) 1879 break; 1880 } 1881 return (NULL); 1882 } 1883 1884 /* 1885 * Search for module in all directories listed in the linker_path. 1886 */ 1887 static char * 1888 linker_search_kld(const char *name) 1889 { 1890 char *cp, *ep, *result; 1891 int len; 1892 1893 /* qualified at all? */ 1894 if (index(name, '/')) 1895 return (linker_strdup(name)); 1896 1897 /* traverse the linker path */ 1898 len = strlen(name); 1899 for (ep = linker_path; *ep; ep++) { 1900 cp = ep; 1901 /* find the end of this component */ 1902 for (; *ep != 0 && *ep != ';'; ep++); 1903 result = linker_lookup_file(cp, ep - cp, name, len, NULL); 1904 if (result != NULL) 1905 return (result); 1906 } 1907 return (NULL); 1908 } 1909 1910 static const char * 1911 linker_basename(const char *path) 1912 { 1913 const char *filename; 1914 1915 filename = rindex(path, '/'); 1916 if (filename == NULL) 1917 return path; 1918 if (filename[1]) 1919 filename++; 1920 return (filename); 1921 } 1922 1923 #ifdef HWPMC_HOOKS 1924 /* 1925 * Inform hwpmc about the set of kernel modules currently loaded. 1926 */ 1927 void * 1928 linker_hwpmc_list_objects(void) 1929 { 1930 linker_file_t lf; 1931 struct pmckern_map_in *kobase; 1932 int i, nmappings; 1933 1934 nmappings = 0; 1935 KLD_LOCK(); 1936 TAILQ_FOREACH(lf, &linker_files, link) 1937 nmappings++; 1938 1939 /* Allocate nmappings + 1 entries. */ 1940 kobase = malloc((nmappings + 1) * sizeof(struct pmckern_map_in), 1941 M_LINKER, M_WAITOK | M_ZERO); 1942 i = 0; 1943 TAILQ_FOREACH(lf, &linker_files, link) { 1944 1945 /* Save the info for this linker file. */ 1946 kobase[i].pm_file = lf->filename; 1947 kobase[i].pm_address = (uintptr_t)lf->address; 1948 i++; 1949 } 1950 KLD_UNLOCK(); 1951 1952 KASSERT(i > 0, ("linker_hpwmc_list_objects: no kernel objects?")); 1953 1954 /* The last entry of the malloced area comprises of all zeros. */ 1955 KASSERT(kobase[i].pm_file == NULL, 1956 ("linker_hwpmc_list_objects: last object not NULL")); 1957 1958 return ((void *)kobase); 1959 } 1960 #endif 1961 1962 /* 1963 * Find a file which contains given module and load it, if "parent" is not 1964 * NULL, register a reference to it. 1965 */ 1966 static int 1967 linker_load_module(const char *kldname, const char *modname, 1968 struct linker_file *parent, struct mod_depend *verinfo, 1969 struct linker_file **lfpp) 1970 { 1971 linker_file_t lfdep; 1972 const char *filename; 1973 char *pathname; 1974 int error; 1975 1976 KLD_LOCK_ASSERT(); 1977 if (modname == NULL) { 1978 /* 1979 * We have to load KLD 1980 */ 1981 KASSERT(verinfo == NULL, ("linker_load_module: verinfo" 1982 " is not NULL")); 1983 pathname = linker_search_kld(kldname); 1984 } else { 1985 if (modlist_lookup2(modname, verinfo) != NULL) 1986 return (EEXIST); 1987 if (kldname != NULL) 1988 pathname = linker_strdup(kldname); 1989 else if (rootvnode == NULL) 1990 pathname = NULL; 1991 else 1992 /* 1993 * Need to find a KLD with required module 1994 */ 1995 pathname = linker_search_module(modname, 1996 strlen(modname), verinfo); 1997 } 1998 if (pathname == NULL) 1999 return (ENOENT); 2000 2001 /* 2002 * Can't load more than one file with the same basename XXX: 2003 * Actually it should be possible to have multiple KLDs with 2004 * the same basename but different path because they can 2005 * provide different versions of the same modules. 2006 */ 2007 filename = linker_basename(pathname); 2008 if (linker_find_file_by_name(filename)) 2009 error = EEXIST; 2010 else do { 2011 error = linker_load_file(pathname, &lfdep); 2012 if (error) 2013 break; 2014 if (modname && verinfo && 2015 modlist_lookup2(modname, verinfo) == NULL) { 2016 linker_file_unload(lfdep, LINKER_UNLOAD_FORCE); 2017 error = ENOENT; 2018 break; 2019 } 2020 if (parent) { 2021 error = linker_file_add_dependency(parent, lfdep); 2022 if (error) 2023 break; 2024 } 2025 if (lfpp) 2026 *lfpp = lfdep; 2027 } while (0); 2028 free(pathname, M_LINKER); 2029 return (error); 2030 } 2031 2032 /* 2033 * This routine is responsible for finding dependencies of userland initiated 2034 * kldload(2)'s of files. 2035 */ 2036 int 2037 linker_load_dependencies(linker_file_t lf) 2038 { 2039 linker_file_t lfdep; 2040 struct mod_metadata **start, **stop, **mdp, **nmdp; 2041 struct mod_metadata *mp, *nmp; 2042 struct mod_depend *verinfo; 2043 modlist_t mod; 2044 const char *modname, *nmodname; 2045 int ver, error = 0, count; 2046 2047 /* 2048 * All files are dependant on /kernel. 2049 */ 2050 KLD_LOCK_ASSERT(); 2051 if (linker_kernel_file) { 2052 linker_kernel_file->refs++; 2053 error = linker_file_add_dependency(lf, linker_kernel_file); 2054 if (error) 2055 return (error); 2056 } 2057 if (linker_file_lookup_set(lf, MDT_SETNAME, &start, &stop, 2058 &count) != 0) 2059 return (0); 2060 for (mdp = start; mdp < stop; mdp++) { 2061 mp = *mdp; 2062 if (mp->md_type != MDT_VERSION) 2063 continue; 2064 modname = mp->md_cval; 2065 ver = ((struct mod_version *)mp->md_data)->mv_version; 2066 mod = modlist_lookup(modname, ver); 2067 if (mod != NULL) { 2068 printf("interface %s.%d already present in the KLD" 2069 " '%s'!\n", modname, ver, 2070 mod->container->filename); 2071 return (EEXIST); 2072 } 2073 } 2074 2075 for (mdp = start; mdp < stop; mdp++) { 2076 mp = *mdp; 2077 if (mp->md_type != MDT_DEPEND) 2078 continue; 2079 modname = mp->md_cval; 2080 verinfo = mp->md_data; 2081 nmodname = NULL; 2082 for (nmdp = start; nmdp < stop; nmdp++) { 2083 nmp = *nmdp; 2084 if (nmp->md_type != MDT_VERSION) 2085 continue; 2086 nmodname = nmp->md_cval; 2087 if (strcmp(modname, nmodname) == 0) 2088 break; 2089 } 2090 if (nmdp < stop)/* early exit, it's a self reference */ 2091 continue; 2092 mod = modlist_lookup2(modname, verinfo); 2093 if (mod) { /* woohoo, it's loaded already */ 2094 lfdep = mod->container; 2095 lfdep->refs++; 2096 error = linker_file_add_dependency(lf, lfdep); 2097 if (error) 2098 break; 2099 continue; 2100 } 2101 error = linker_load_module(NULL, modname, lf, verinfo, NULL); 2102 if (error) { 2103 printf("KLD %s: depends on %s - not available or" 2104 " version mismatch\n", lf->filename, modname); 2105 break; 2106 } 2107 } 2108 2109 if (error) 2110 return (error); 2111 linker_addmodules(lf, start, stop, 0); 2112 return (error); 2113 } 2114 2115 static int 2116 sysctl_kern_function_list_iterate(const char *name, void *opaque) 2117 { 2118 struct sysctl_req *req; 2119 2120 req = opaque; 2121 return (SYSCTL_OUT(req, name, strlen(name) + 1)); 2122 } 2123 2124 /* 2125 * Export a nul-separated, double-nul-terminated list of all function names 2126 * in the kernel. 2127 */ 2128 static int 2129 sysctl_kern_function_list(SYSCTL_HANDLER_ARGS) 2130 { 2131 linker_file_t lf; 2132 int error; 2133 2134 #ifdef MAC 2135 error = mac_kld_check_stat(req->td->td_ucred); 2136 if (error) 2137 return (error); 2138 #endif 2139 error = sysctl_wire_old_buffer(req, 0); 2140 if (error != 0) 2141 return (error); 2142 KLD_LOCK(); 2143 TAILQ_FOREACH(lf, &linker_files, link) { 2144 error = LINKER_EACH_FUNCTION_NAME(lf, 2145 sysctl_kern_function_list_iterate, req); 2146 if (error) { 2147 KLD_UNLOCK(); 2148 return (error); 2149 } 2150 } 2151 KLD_UNLOCK(); 2152 return (SYSCTL_OUT(req, "", 1)); 2153 } 2154 2155 SYSCTL_PROC(_kern, OID_AUTO, function_list, CTLTYPE_OPAQUE | CTLFLAG_RD, 2156 NULL, 0, sysctl_kern_function_list, "", "kernel function list"); 2157