Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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FreeBSD/Linux Kernel Cross Reference
sys/kern/kern_linker.c
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1 /*- 2 * Copyright (c) 1997-2000 Doug Rabson 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 */ 26 27 #include <sys/cdefs.h> 28 __FBSDID("$FreeBSD$"); 29 30 #include "opt_ddb.h" 31 #include "opt_hwpmc_hooks.h" 32 #include "opt_mac.h" 33 34 #include <sys/param.h> 35 #include <sys/kernel.h> 36 #include <sys/systm.h> 37 #include <sys/malloc.h> 38 #include <sys/sysproto.h> 39 #include <sys/sysent.h> 40 #include <sys/priv.h> 41 #include <sys/proc.h> 42 #include <sys/lock.h> 43 #include <sys/mutex.h> 44 #include <sys/sx.h> 45 #include <sys/module.h> 46 #include <sys/mount.h> 47 #include <sys/linker.h> 48 #include <sys/fcntl.h> 49 #include <sys/libkern.h> 50 #include <sys/namei.h> 51 #include <sys/vnode.h> 52 #include <sys/syscallsubr.h> 53 #include <sys/sysctl.h> 54 55 #include <security/mac/mac_framework.h> 56 57 #include "linker_if.h" 58 59 #ifdef HWPMC_HOOKS 60 #include <sys/pmckern.h> 61 #endif 62 63 #ifdef KLD_DEBUG 64 int kld_debug = 0; 65 #endif 66 67 #define KLD_LOCK() sx_xlock(&kld_sx) 68 #define KLD_UNLOCK() sx_xunlock(&kld_sx) 69 #define KLD_LOCKED() sx_xlocked(&kld_sx) 70 #define KLD_LOCK_ASSERT() do { \ 71 if (!cold) \ 72 sx_assert(&kld_sx, SX_XLOCKED); \ 73 } while (0) 74 75 /* 76 * static char *linker_search_path(const char *name, struct mod_depend 77 * *verinfo); 78 */ 79 static const char *linker_basename(const char *path); 80 81 /* 82 * Find a currently loaded file given its filename. 83 */ 84 static linker_file_t linker_find_file_by_name(const char* _filename); 85 86 /* 87 * Find a currently loaded file given its file id. 88 */ 89 static linker_file_t linker_find_file_by_id(int _fileid); 90 91 /* Metadata from the static kernel */ 92 SET_DECLARE(modmetadata_set, struct mod_metadata); 93 94 MALLOC_DEFINE(M_LINKER, "linker", "kernel linker"); 95 96 linker_file_t linker_kernel_file; 97 98 static struct sx kld_sx; /* kernel linker lock */ 99 100 static linker_class_list_t classes; 101 static linker_file_list_t linker_files; 102 static int next_file_id = 1; 103 static int linker_no_more_classes = 0; 104 105 #define LINKER_GET_NEXT_FILE_ID(a) do { \ 106 linker_file_t lftmp; \ 107 \ 108 KLD_LOCK_ASSERT(); \ 109 retry: \ 110 TAILQ_FOREACH(lftmp, &linker_files, link) { \ 111 if (next_file_id == lftmp->id) { \ 112 next_file_id++; \ 113 goto retry; \ 114 } \ 115 } \ 116 (a) = next_file_id; \ 117 } while(0) 118 119 120 /* XXX wrong name; we're looking at version provision tags here, not modules */ 121 typedef TAILQ_HEAD(, modlist) modlisthead_t; 122 struct modlist { 123 TAILQ_ENTRY(modlist) link; /* chain together all modules */ 124 linker_file_t container; 125 const char *name; 126 int version; 127 }; 128 typedef struct modlist *modlist_t; 129 static modlisthead_t found_modules; 130 131 static int linker_file_add_dependency(linker_file_t file, 132 linker_file_t dep); 133 static caddr_t linker_file_lookup_symbol_internal(linker_file_t file, 134 const char* name, int deps); 135 static int linker_load_module(const char *kldname, 136 const char *modname, struct linker_file *parent, 137 struct mod_depend *verinfo, struct linker_file **lfpp); 138 static modlist_t modlist_lookup2(const char *name, struct mod_depend *verinfo); 139 140 static char * 141 linker_strdup(const char *str) 142 { 143 char *result; 144 145 if ((result = malloc((strlen(str) + 1), M_LINKER, M_WAITOK)) != NULL) 146 strcpy(result, str); 147 return (result); 148 } 149 150 static void 151 linker_init(void *arg) 152 { 153 154 sx_init(&kld_sx, "kernel linker"); 155 TAILQ_INIT(&classes); 156 TAILQ_INIT(&linker_files); 157 } 158 159 SYSINIT(linker, SI_SUB_KLD, SI_ORDER_FIRST, linker_init, 0) 160 161 static void 162 linker_stop_class_add(void *arg) 163 { 164 165 linker_no_more_classes = 1; 166 } 167 168 SYSINIT(linker_class, SI_SUB_KLD, SI_ORDER_ANY, linker_stop_class_add, NULL) 169 170 int 171 linker_add_class(linker_class_t lc) 172 { 173 174 /* 175 * We disallow any class registration past SI_ORDER_ANY 176 * of SI_SUB_KLD. We bump the reference count to keep the 177 * ops from being freed. 178 */ 179 if (linker_no_more_classes == 1) 180 return (EPERM); 181 kobj_class_compile((kobj_class_t) lc); 182 ((kobj_class_t)lc)->refs++; /* XXX: kobj_mtx */ 183 TAILQ_INSERT_TAIL(&classes, lc, link); 184 return (0); 185 } 186 187 static void 188 linker_file_sysinit(linker_file_t lf) 189 { 190 struct sysinit **start, **stop, **sipp, **xipp, *save; 191 192 KLD_DPF(FILE, ("linker_file_sysinit: calling SYSINITs for %s\n", 193 lf->filename)); 194 195 if (linker_file_lookup_set(lf, "sysinit_set", &start, &stop, NULL) != 0) 196 return; 197 /* 198 * Perform a bubble sort of the system initialization objects by 199 * their subsystem (primary key) and order (secondary key). 200 * 201 * Since some things care about execution order, this is the operation 202 * which ensures continued function. 203 */ 204 for (sipp = start; sipp < stop; sipp++) { 205 for (xipp = sipp + 1; xipp < stop; xipp++) { 206 if ((*sipp)->subsystem < (*xipp)->subsystem || 207 ((*sipp)->subsystem == (*xipp)->subsystem && 208 (*sipp)->order <= (*xipp)->order)) 209 continue; /* skip */ 210 save = *sipp; 211 *sipp = *xipp; 212 *xipp = save; 213 } 214 } 215 216 /* 217 * Traverse the (now) ordered list of system initialization tasks. 218 * Perform each task, and continue on to the next task. 219 */ 220 mtx_lock(&Giant); 221 for (sipp = start; sipp < stop; sipp++) { 222 if ((*sipp)->subsystem == SI_SUB_DUMMY) 223 continue; /* skip dummy task(s) */ 224 225 /* Call function */ 226 (*((*sipp)->func)) ((*sipp)->udata); 227 } 228 mtx_unlock(&Giant); 229 } 230 231 static void 232 linker_file_sysuninit(linker_file_t lf) 233 { 234 struct sysinit **start, **stop, **sipp, **xipp, *save; 235 236 KLD_DPF(FILE, ("linker_file_sysuninit: calling SYSUNINITs for %s\n", 237 lf->filename)); 238 239 if (linker_file_lookup_set(lf, "sysuninit_set", &start, &stop, 240 NULL) != 0) 241 return; 242 243 /* 244 * Perform a reverse bubble sort of the system initialization objects 245 * by their subsystem (primary key) and order (secondary key). 246 * 247 * Since some things care about execution order, this is the operation 248 * which ensures continued function. 249 */ 250 for (sipp = start; sipp < stop; sipp++) { 251 for (xipp = sipp + 1; xipp < stop; xipp++) { 252 if ((*sipp)->subsystem > (*xipp)->subsystem || 253 ((*sipp)->subsystem == (*xipp)->subsystem && 254 (*sipp)->order >= (*xipp)->order)) 255 continue; /* skip */ 256 save = *sipp; 257 *sipp = *xipp; 258 *xipp = save; 259 } 260 } 261 262 /* 263 * Traverse the (now) ordered list of system initialization tasks. 264 * Perform each task, and continue on to the next task. 265 */ 266 mtx_lock(&Giant); 267 for (sipp = start; sipp < stop; sipp++) { 268 if ((*sipp)->subsystem == SI_SUB_DUMMY) 269 continue; /* skip dummy task(s) */ 270 271 /* Call function */ 272 (*((*sipp)->func)) ((*sipp)->udata); 273 } 274 mtx_unlock(&Giant); 275 } 276 277 static void 278 linker_file_register_sysctls(linker_file_t lf) 279 { 280 struct sysctl_oid **start, **stop, **oidp; 281 282 KLD_DPF(FILE, 283 ("linker_file_register_sysctls: registering SYSCTLs for %s\n", 284 lf->filename)); 285 286 if (linker_file_lookup_set(lf, "sysctl_set", &start, &stop, NULL) != 0) 287 return; 288 289 mtx_lock(&Giant); 290 for (oidp = start; oidp < stop; oidp++) 291 sysctl_register_oid(*oidp); 292 mtx_unlock(&Giant); 293 } 294 295 static void 296 linker_file_unregister_sysctls(linker_file_t lf) 297 { 298 struct sysctl_oid **start, **stop, **oidp; 299 300 KLD_DPF(FILE, ("linker_file_unregister_sysctls: registering SYSCTLs" 301 " for %s\n", lf->filename)); 302 303 if (linker_file_lookup_set(lf, "sysctl_set", &start, &stop, NULL) != 0) 304 return; 305 306 mtx_lock(&Giant); 307 for (oidp = start; oidp < stop; oidp++) 308 sysctl_unregister_oid(*oidp); 309 mtx_unlock(&Giant); 310 } 311 312 static int 313 linker_file_register_modules(linker_file_t lf) 314 { 315 struct mod_metadata **start, **stop, **mdp; 316 const moduledata_t *moddata; 317 int first_error, error; 318 319 KLD_DPF(FILE, ("linker_file_register_modules: registering modules" 320 " in %s\n", lf->filename)); 321 322 if (linker_file_lookup_set(lf, "modmetadata_set", &start, 323 &stop, NULL) != 0) { 324 /* 325 * This fallback should be unnecessary, but if we get booted 326 * from boot2 instead of loader and we are missing our 327 * metadata then we have to try the best we can. 328 */ 329 if (lf == linker_kernel_file) { 330 start = SET_BEGIN(modmetadata_set); 331 stop = SET_LIMIT(modmetadata_set); 332 } else 333 return (0); 334 } 335 first_error = 0; 336 for (mdp = start; mdp < stop; mdp++) { 337 if ((*mdp)->md_type != MDT_MODULE) 338 continue; 339 moddata = (*mdp)->md_data; 340 KLD_DPF(FILE, ("Registering module %s in %s\n", 341 moddata->name, lf->filename)); 342 error = module_register(moddata, lf); 343 if (error) { 344 printf("Module %s failed to register: %d\n", 345 moddata->name, error); 346 if (first_error == 0) 347 first_error = error; 348 } 349 } 350 return (first_error); 351 } 352 353 static void 354 linker_init_kernel_modules(void) 355 { 356 357 linker_file_register_modules(linker_kernel_file); 358 } 359 360 SYSINIT(linker_kernel, SI_SUB_KLD, SI_ORDER_ANY, linker_init_kernel_modules, 0) 361 362 static int 363 linker_load_file(const char *filename, linker_file_t *result) 364 { 365 linker_class_t lc; 366 linker_file_t lf; 367 int foundfile, error; 368 369 /* Refuse to load modules if securelevel raised */ 370 if (securelevel > 0) 371 return (EPERM); 372 373 KLD_LOCK_ASSERT(); 374 lf = linker_find_file_by_name(filename); 375 if (lf) { 376 KLD_DPF(FILE, ("linker_load_file: file %s is already loaded," 377 " incrementing refs\n", filename)); 378 *result = lf; 379 lf->refs++; 380 return (0); 381 } 382 foundfile = 0; 383 error = 0; 384 385 /* 386 * We do not need to protect (lock) classes here because there is 387 * no class registration past startup (SI_SUB_KLD, SI_ORDER_ANY) 388 * and there is no class deregistration mechanism at this time. 389 */ 390 TAILQ_FOREACH(lc, &classes, link) { 391 KLD_DPF(FILE, ("linker_load_file: trying to load %s\n", 392 filename)); 393 error = LINKER_LOAD_FILE(lc, filename, &lf); 394 /* 395 * If we got something other than ENOENT, then it exists but 396 * we cannot load it for some other reason. 397 */ 398 if (error != ENOENT) 399 foundfile = 1; 400 if (lf) { 401 error = linker_file_register_modules(lf); 402 if (error == EEXIST) { 403 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 404 return (error); 405 } 406 KLD_UNLOCK(); 407 linker_file_register_sysctls(lf); 408 linker_file_sysinit(lf); 409 KLD_LOCK(); 410 lf->flags |= LINKER_FILE_LINKED; 411 *result = lf; 412 return (0); 413 } 414 } 415 /* 416 * Less than ideal, but tells the user whether it failed to load or 417 * the module was not found. 418 */ 419 if (foundfile) { 420 /* 421 * Format not recognized or otherwise unloadable. 422 * When loading a module that is statically built into 423 * the kernel EEXIST percolates back up as the return 424 * value. Preserve this so that apps like sysinstall 425 * can recognize this special case and not post bogus 426 * dialog boxes. 427 */ 428 if (error != EEXIST) 429 error = ENOEXEC; 430 } else 431 error = ENOENT; /* Nothing found */ 432 return (error); 433 } 434 435 int 436 linker_reference_module(const char *modname, struct mod_depend *verinfo, 437 linker_file_t *result) 438 { 439 modlist_t mod; 440 int error; 441 442 KLD_LOCK(); 443 if ((mod = modlist_lookup2(modname, verinfo)) != NULL) { 444 *result = mod->container; 445 (*result)->refs++; 446 KLD_UNLOCK(); 447 return (0); 448 } 449 450 error = linker_load_module(NULL, modname, NULL, verinfo, result); 451 KLD_UNLOCK(); 452 return (error); 453 } 454 455 int 456 linker_release_module(const char *modname, struct mod_depend *verinfo, 457 linker_file_t lf) 458 { 459 modlist_t mod; 460 int error; 461 462 KLD_LOCK(); 463 if (lf == NULL) { 464 KASSERT(modname != NULL, 465 ("linker_release_module: no file or name")); 466 mod = modlist_lookup2(modname, verinfo); 467 if (mod == NULL) { 468 KLD_UNLOCK(); 469 return (ESRCH); 470 } 471 lf = mod->container; 472 } else 473 KASSERT(modname == NULL && verinfo == NULL, 474 ("linker_release_module: both file and name")); 475 error = linker_file_unload(lf, LINKER_UNLOAD_NORMAL); 476 KLD_UNLOCK(); 477 return (error); 478 } 479 480 static linker_file_t 481 linker_find_file_by_name(const char *filename) 482 { 483 linker_file_t lf; 484 char *koname; 485 486 koname = malloc(strlen(filename) + 4, M_LINKER, M_WAITOK); 487 sprintf(koname, "%s.ko", filename); 488 489 KLD_LOCK_ASSERT(); 490 TAILQ_FOREACH(lf, &linker_files, link) { 491 if (strcmp(lf->filename, koname) == 0) 492 break; 493 if (strcmp(lf->filename, filename) == 0) 494 break; 495 } 496 free(koname, M_LINKER); 497 return (lf); 498 } 499 500 static linker_file_t 501 linker_find_file_by_id(int fileid) 502 { 503 linker_file_t lf; 504 505 KLD_LOCK_ASSERT(); 506 TAILQ_FOREACH(lf, &linker_files, link) 507 if (lf->id == fileid && lf->flags & LINKER_FILE_LINKED) 508 break; 509 return (lf); 510 } 511 512 int 513 linker_file_foreach(linker_predicate_t *predicate, void *context) 514 { 515 linker_file_t lf; 516 int retval = 0; 517 518 KLD_LOCK(); 519 TAILQ_FOREACH(lf, &linker_files, link) { 520 retval = predicate(lf, context); 521 if (retval != 0) 522 break; 523 } 524 KLD_UNLOCK(); 525 return (retval); 526 } 527 528 linker_file_t 529 linker_make_file(const char *pathname, linker_class_t lc) 530 { 531 linker_file_t lf; 532 const char *filename; 533 534 KLD_LOCK_ASSERT(); 535 filename = linker_basename(pathname); 536 537 KLD_DPF(FILE, ("linker_make_file: new file, filename=%s\n", filename)); 538 lf = (linker_file_t)kobj_create((kobj_class_t)lc, M_LINKER, M_WAITOK); 539 if (lf == NULL) 540 return (NULL); 541 lf->refs = 1; 542 lf->userrefs = 0; 543 lf->flags = 0; 544 lf->filename = linker_strdup(filename); 545 LINKER_GET_NEXT_FILE_ID(lf->id); 546 lf->ndeps = 0; 547 lf->deps = NULL; 548 STAILQ_INIT(&lf->common); 549 TAILQ_INIT(&lf->modules); 550 TAILQ_INSERT_TAIL(&linker_files, lf, link); 551 return (lf); 552 } 553 554 int 555 linker_file_unload(linker_file_t file, int flags) 556 { 557 module_t mod, next; 558 modlist_t ml, nextml; 559 struct common_symbol *cp; 560 int error, i; 561 562 /* Refuse to unload modules if securelevel raised. */ 563 if (securelevel > 0) 564 return (EPERM); 565 566 KLD_LOCK_ASSERT(); 567 KLD_DPF(FILE, ("linker_file_unload: lf->refs=%d\n", file->refs)); 568 569 /* Easy case of just dropping a reference. */ 570 if (file->refs > 1) { 571 file->refs--; 572 return (0); 573 } 574 575 KLD_DPF(FILE, ("linker_file_unload: file is unloading," 576 " informing modules\n")); 577 578 /* 579 * Inform any modules associated with this file. 580 */ 581 MOD_XLOCK; 582 for (mod = TAILQ_FIRST(&file->modules); mod; mod = next) { 583 next = module_getfnext(mod); 584 MOD_XUNLOCK; 585 586 /* 587 * Give the module a chance to veto the unload. 588 */ 589 if ((error = module_unload(mod, flags)) != 0) { 590 KLD_DPF(FILE, ("linker_file_unload: module %p" 591 " vetoes unload\n", mod)); 592 return (error); 593 } 594 MOD_XLOCK; 595 module_release(mod); 596 } 597 MOD_XUNLOCK; 598 599 TAILQ_FOREACH_SAFE(ml, &found_modules, link, nextml) { 600 if (ml->container == file) { 601 TAILQ_REMOVE(&found_modules, ml, link); 602 free(ml, M_LINKER); 603 } 604 } 605 606 /* 607 * Don't try to run SYSUNINITs if we are unloaded due to a 608 * link error. 609 */ 610 if (file->flags & LINKER_FILE_LINKED) { 611 linker_file_sysuninit(file); 612 linker_file_unregister_sysctls(file); 613 } 614 TAILQ_REMOVE(&linker_files, file, link); 615 616 if (file->deps) { 617 for (i = 0; i < file->ndeps; i++) 618 linker_file_unload(file->deps[i], flags); 619 free(file->deps, M_LINKER); 620 file->deps = NULL; 621 } 622 while ((cp = STAILQ_FIRST(&file->common)) != NULL) { 623 STAILQ_REMOVE_HEAD(&file->common, link); 624 free(cp, M_LINKER); 625 } 626 627 LINKER_UNLOAD(file); 628 if (file->filename) { 629 free(file->filename, M_LINKER); 630 file->filename = NULL; 631 } 632 kobj_delete((kobj_t) file, M_LINKER); 633 return (0); 634 } 635 636 static int 637 linker_file_add_dependency(linker_file_t file, linker_file_t dep) 638 { 639 linker_file_t *newdeps; 640 641 KLD_LOCK_ASSERT(); 642 newdeps = malloc((file->ndeps + 1) * sizeof(linker_file_t *), 643 M_LINKER, M_WAITOK | M_ZERO); 644 if (newdeps == NULL) 645 return (ENOMEM); 646 647 if (file->deps) { 648 bcopy(file->deps, newdeps, 649 file->ndeps * sizeof(linker_file_t *)); 650 free(file->deps, M_LINKER); 651 } 652 file->deps = newdeps; 653 file->deps[file->ndeps] = dep; 654 file->ndeps++; 655 return (0); 656 } 657 658 /* 659 * Locate a linker set and its contents. This is a helper function to avoid 660 * linker_if.h exposure elsewhere. Note: firstp and lastp are really void **. 661 * This function is used in this file so we can avoid having lots of (void **) 662 * casts. 663 */ 664 int 665 linker_file_lookup_set(linker_file_t file, const char *name, 666 void *firstp, void *lastp, int *countp) 667 { 668 int error, locked; 669 670 locked = KLD_LOCKED(); 671 if (!locked) 672 KLD_LOCK(); 673 error = LINKER_LOOKUP_SET(file, name, firstp, lastp, countp); 674 if (!locked) 675 KLD_UNLOCK(); 676 return (error); 677 } 678 679 caddr_t 680 linker_file_lookup_symbol(linker_file_t file, const char *name, int deps) 681 { 682 caddr_t sym; 683 int locked; 684 685 locked = KLD_LOCKED(); 686 if (!locked) 687 KLD_LOCK(); 688 sym = linker_file_lookup_symbol_internal(file, name, deps); 689 if (!locked) 690 KLD_UNLOCK(); 691 return (sym); 692 } 693 694 static caddr_t 695 linker_file_lookup_symbol_internal(linker_file_t file, const char *name, 696 int deps) 697 { 698 c_linker_sym_t sym; 699 linker_symval_t symval; 700 caddr_t address; 701 size_t common_size = 0; 702 int i; 703 704 KLD_LOCK_ASSERT(); 705 KLD_DPF(SYM, ("linker_file_lookup_symbol: file=%p, name=%s, deps=%d\n", 706 file, name, deps)); 707 708 if (LINKER_LOOKUP_SYMBOL(file, name, &sym) == 0) { 709 LINKER_SYMBOL_VALUES(file, sym, &symval); 710 if (symval.value == 0) 711 /* 712 * For commons, first look them up in the 713 * dependencies and only allocate space if not found 714 * there. 715 */ 716 common_size = symval.size; 717 else { 718 KLD_DPF(SYM, ("linker_file_lookup_symbol: symbol" 719 ".value=%p\n", symval.value)); 720 return (symval.value); 721 } 722 } 723 if (deps) { 724 for (i = 0; i < file->ndeps; i++) { 725 address = linker_file_lookup_symbol_internal( 726 file->deps[i], name, 0); 727 if (address) { 728 KLD_DPF(SYM, ("linker_file_lookup_symbol:" 729 " deps value=%p\n", address)); 730 return (address); 731 } 732 } 733 } 734 if (common_size > 0) { 735 /* 736 * This is a common symbol which was not found in the 737 * dependencies. We maintain a simple common symbol table in 738 * the file object. 739 */ 740 struct common_symbol *cp; 741 742 STAILQ_FOREACH(cp, &file->common, link) { 743 if (strcmp(cp->name, name) == 0) { 744 KLD_DPF(SYM, ("linker_file_lookup_symbol:" 745 " old common value=%p\n", cp->address)); 746 return (cp->address); 747 } 748 } 749 /* 750 * Round the symbol size up to align. 751 */ 752 common_size = (common_size + sizeof(int) - 1) & -sizeof(int); 753 cp = malloc(sizeof(struct common_symbol) 754 + common_size + strlen(name) + 1, M_LINKER, 755 M_WAITOK | M_ZERO); 756 cp->address = (caddr_t)(cp + 1); 757 cp->name = cp->address + common_size; 758 strcpy(cp->name, name); 759 bzero(cp->address, common_size); 760 STAILQ_INSERT_TAIL(&file->common, cp, link); 761 762 KLD_DPF(SYM, ("linker_file_lookup_symbol: new common" 763 " value=%p\n", cp->address)); 764 return (cp->address); 765 } 766 KLD_DPF(SYM, ("linker_file_lookup_symbol: fail\n")); 767 return (0); 768 } 769 770 #ifdef DDB 771 /* 772 * DDB Helpers. DDB has to look across multiple files with their own symbol 773 * tables and string tables. 774 * 775 * Note that we do not obey list locking protocols here. We really don't need 776 * DDB to hang because somebody's got the lock held. We'll take the chance 777 * that the files list is inconsistant instead. 778 */ 779 780 int 781 linker_ddb_lookup(const char *symstr, c_linker_sym_t *sym) 782 { 783 linker_file_t lf; 784 785 TAILQ_FOREACH(lf, &linker_files, link) { 786 if (LINKER_LOOKUP_SYMBOL(lf, symstr, sym) == 0) 787 return (0); 788 } 789 return (ENOENT); 790 } 791 792 int 793 linker_ddb_search_symbol(caddr_t value, c_linker_sym_t *sym, long *diffp) 794 { 795 linker_file_t lf; 796 c_linker_sym_t best, es; 797 u_long diff, bestdiff, off; 798 799 best = 0; 800 off = (uintptr_t)value; 801 bestdiff = off; 802 TAILQ_FOREACH(lf, &linker_files, link) { 803 if (LINKER_SEARCH_SYMBOL(lf, value, &es, &diff) != 0) 804 continue; 805 if (es != 0 && diff < bestdiff) { 806 best = es; 807 bestdiff = diff; 808 } 809 if (bestdiff == 0) 810 break; 811 } 812 if (best) { 813 *sym = best; 814 *diffp = bestdiff; 815 return (0); 816 } else { 817 *sym = 0; 818 *diffp = off; 819 return (ENOENT); 820 } 821 } 822 823 int 824 linker_ddb_symbol_values(c_linker_sym_t sym, linker_symval_t *symval) 825 { 826 linker_file_t lf; 827 828 TAILQ_FOREACH(lf, &linker_files, link) { 829 if (LINKER_SYMBOL_VALUES(lf, sym, symval) == 0) 830 return (0); 831 } 832 return (ENOENT); 833 } 834 #endif 835 836 /* 837 * Syscalls. 838 */ 839 int 840 kern_kldload(struct thread *td, const char *file, int *fileid) 841 { 842 #ifdef HWPMC_HOOKS 843 struct pmckern_map_in pkm; 844 #endif 845 const char *kldname, *modname; 846 linker_file_t lf; 847 int error; 848 849 if ((error = securelevel_gt(td->td_ucred, 0)) != 0) 850 return (error); 851 852 if ((error = priv_check(td, PRIV_KLD_LOAD)) != 0) 853 return (error); 854 855 /* 856 * If file does not contain a qualified name or any dot in it 857 * (kldname.ko, or kldname.ver.ko) treat it as an interface 858 * name. 859 */ 860 if (index(file, '/') || index(file, '.')) { 861 kldname = file; 862 modname = NULL; 863 } else { 864 kldname = NULL; 865 modname = file; 866 } 867 868 KLD_LOCK(); 869 error = linker_load_module(kldname, modname, NULL, NULL, &lf); 870 if (error) 871 goto unlock; 872 #ifdef HWPMC_HOOKS 873 pkm.pm_file = lf->filename; 874 pkm.pm_address = (uintptr_t) lf->address; 875 PMC_CALL_HOOK(td, PMC_FN_KLD_LOAD, (void *) &pkm); 876 #endif 877 lf->userrefs++; 878 if (fileid != NULL) 879 *fileid = lf->id; 880 unlock: 881 KLD_UNLOCK(); 882 return (error); 883 } 884 885 int 886 kldload(struct thread *td, struct kldload_args *uap) 887 { 888 char *pathname = NULL; 889 int error, fileid; 890 891 td->td_retval[0] = -1; 892 893 pathname = malloc(MAXPATHLEN, M_TEMP, M_WAITOK); 894 error = copyinstr(uap->file, pathname, MAXPATHLEN, NULL); 895 if (error == 0) { 896 error = kern_kldload(td, pathname, &fileid); 897 if (error == 0) 898 td->td_retval[0] = fileid; 899 } 900 free(pathname, M_TEMP); 901 return (error); 902 } 903 904 int 905 kern_kldunload(struct thread *td, int fileid, int flags) 906 { 907 #ifdef HWPMC_HOOKS 908 struct pmckern_map_out pkm; 909 #endif 910 linker_file_t lf; 911 int error = 0; 912 913 if ((error = securelevel_gt(td->td_ucred, 0)) != 0) 914 return (error); 915 916 if ((error = priv_check(td, PRIV_KLD_UNLOAD)) != 0) 917 return (error); 918 919 KLD_LOCK(); 920 lf = linker_find_file_by_id(fileid); 921 if (lf) { 922 KLD_DPF(FILE, ("kldunload: lf->userrefs=%d\n", lf->userrefs)); 923 if (lf->userrefs == 0) { 924 /* 925 * XXX: maybe LINKER_UNLOAD_FORCE should override ? 926 */ 927 printf("kldunload: attempt to unload file that was" 928 " loaded by the kernel\n"); 929 error = EBUSY; 930 } else { 931 #ifdef HWPMC_HOOKS 932 /* Save data needed by hwpmc(4) before unloading. */ 933 pkm.pm_address = (uintptr_t) lf->address; 934 pkm.pm_size = lf->size; 935 #endif 936 lf->userrefs--; 937 error = linker_file_unload(lf, flags); 938 if (error) 939 lf->userrefs++; 940 } 941 } else 942 error = ENOENT; 943 944 #ifdef HWPMC_HOOKS 945 if (error == 0) 946 PMC_CALL_HOOK(td, PMC_FN_KLD_UNLOAD, (void *) &pkm); 947 #endif 948 KLD_UNLOCK(); 949 return (error); 950 } 951 952 int 953 kldunload(struct thread *td, struct kldunload_args *uap) 954 { 955 956 return (kern_kldunload(td, uap->fileid, LINKER_UNLOAD_NORMAL)); 957 } 958 959 int 960 kldunloadf(struct thread *td, struct kldunloadf_args *uap) 961 { 962 963 if (uap->flags != LINKER_UNLOAD_NORMAL && 964 uap->flags != LINKER_UNLOAD_FORCE) 965 return (EINVAL); 966 return (kern_kldunload(td, uap->fileid, uap->flags)); 967 } 968 969 int 970 kldfind(struct thread *td, struct kldfind_args *uap) 971 { 972 char *pathname; 973 const char *filename; 974 linker_file_t lf; 975 int error; 976 977 #ifdef MAC 978 error = mac_check_kld_stat(td->td_ucred); 979 if (error) 980 return (error); 981 #endif 982 983 td->td_retval[0] = -1; 984 985 pathname = malloc(MAXPATHLEN, M_TEMP, M_WAITOK); 986 if ((error = copyinstr(uap->file, pathname, MAXPATHLEN, NULL)) != 0) 987 goto out; 988 989 filename = linker_basename(pathname); 990 KLD_LOCK(); 991 lf = linker_find_file_by_name(filename); 992 if (lf) 993 td->td_retval[0] = lf->id; 994 else 995 error = ENOENT; 996 KLD_UNLOCK(); 997 out: 998 free(pathname, M_TEMP); 999 return (error); 1000 } 1001 1002 int 1003 kldnext(struct thread *td, struct kldnext_args *uap) 1004 { 1005 linker_file_t lf; 1006 int error = 0; 1007 1008 #ifdef MAC 1009 error = mac_check_kld_stat(td->td_ucred); 1010 if (error) 1011 return (error); 1012 #endif 1013 1014 KLD_LOCK(); 1015 if (uap->fileid == 0) 1016 lf = TAILQ_FIRST(&linker_files); 1017 else { 1018 lf = linker_find_file_by_id(uap->fileid); 1019 if (lf == NULL) { 1020 error = ENOENT; 1021 goto out; 1022 } 1023 lf = TAILQ_NEXT(lf, link); 1024 } 1025 1026 /* Skip partially loaded files. */ 1027 while (lf != NULL && !(lf->flags & LINKER_FILE_LINKED)) 1028 lf = TAILQ_NEXT(lf, link); 1029 1030 if (lf) 1031 td->td_retval[0] = lf->id; 1032 else 1033 td->td_retval[0] = 0; 1034 out: 1035 KLD_UNLOCK(); 1036 return (error); 1037 } 1038 1039 int 1040 kldstat(struct thread *td, struct kldstat_args *uap) 1041 { 1042 struct kld_file_stat stat; 1043 linker_file_t lf; 1044 int error, namelen; 1045 1046 /* 1047 * Check the version of the user's structure. 1048 */ 1049 error = copyin(uap->stat, &stat, sizeof(struct kld_file_stat)); 1050 if (error) 1051 return (error); 1052 if (stat.version != sizeof(struct kld_file_stat)) 1053 return (EINVAL); 1054 1055 #ifdef MAC 1056 error = mac_check_kld_stat(td->td_ucred); 1057 if (error) 1058 return (error); 1059 #endif 1060 1061 KLD_LOCK(); 1062 lf = linker_find_file_by_id(uap->fileid); 1063 if (lf == NULL) { 1064 KLD_UNLOCK(); 1065 return (ENOENT); 1066 } 1067 1068 namelen = strlen(lf->filename) + 1; 1069 if (namelen > MAXPATHLEN) 1070 namelen = MAXPATHLEN; 1071 bcopy(lf->filename, &stat.name[0], namelen); 1072 stat.refs = lf->refs; 1073 stat.id = lf->id; 1074 stat.address = lf->address; 1075 stat.size = lf->size; 1076 KLD_UNLOCK(); 1077 1078 td->td_retval[0] = 0; 1079 1080 return (copyout(&stat, uap->stat, sizeof(struct kld_file_stat))); 1081 } 1082 1083 int 1084 kldfirstmod(struct thread *td, struct kldfirstmod_args *uap) 1085 { 1086 linker_file_t lf; 1087 module_t mp; 1088 int error = 0; 1089 1090 #ifdef MAC 1091 error = mac_check_kld_stat(td->td_ucred); 1092 if (error) 1093 return (error); 1094 #endif 1095 1096 KLD_LOCK(); 1097 lf = linker_find_file_by_id(uap->fileid); 1098 if (lf) { 1099 MOD_SLOCK; 1100 mp = TAILQ_FIRST(&lf->modules); 1101 if (mp != NULL) 1102 td->td_retval[0] = module_getid(mp); 1103 else 1104 td->td_retval[0] = 0; 1105 MOD_SUNLOCK; 1106 } else 1107 error = ENOENT; 1108 KLD_UNLOCK(); 1109 return (error); 1110 } 1111 1112 int 1113 kldsym(struct thread *td, struct kldsym_args *uap) 1114 { 1115 char *symstr = NULL; 1116 c_linker_sym_t sym; 1117 linker_symval_t symval; 1118 linker_file_t lf; 1119 struct kld_sym_lookup lookup; 1120 int error = 0; 1121 1122 #ifdef MAC 1123 error = mac_check_kld_stat(td->td_ucred); 1124 if (error) 1125 return (error); 1126 #endif 1127 1128 if ((error = copyin(uap->data, &lookup, sizeof(lookup))) != 0) 1129 return (error); 1130 if (lookup.version != sizeof(lookup) || 1131 uap->cmd != KLDSYM_LOOKUP) 1132 return (EINVAL); 1133 symstr = malloc(MAXPATHLEN, M_TEMP, M_WAITOK); 1134 if ((error = copyinstr(lookup.symname, symstr, MAXPATHLEN, NULL)) != 0) 1135 goto out; 1136 KLD_LOCK(); 1137 if (uap->fileid != 0) { 1138 lf = linker_find_file_by_id(uap->fileid); 1139 if (lf == NULL) 1140 error = ENOENT; 1141 else if (LINKER_LOOKUP_SYMBOL(lf, symstr, &sym) == 0 && 1142 LINKER_SYMBOL_VALUES(lf, sym, &symval) == 0) { 1143 lookup.symvalue = (uintptr_t) symval.value; 1144 lookup.symsize = symval.size; 1145 error = copyout(&lookup, uap->data, sizeof(lookup)); 1146 } else 1147 error = ENOENT; 1148 } else { 1149 TAILQ_FOREACH(lf, &linker_files, link) { 1150 if (LINKER_LOOKUP_SYMBOL(lf, symstr, &sym) == 0 && 1151 LINKER_SYMBOL_VALUES(lf, sym, &symval) == 0) { 1152 lookup.symvalue = (uintptr_t)symval.value; 1153 lookup.symsize = symval.size; 1154 error = copyout(&lookup, uap->data, 1155 sizeof(lookup)); 1156 break; 1157 } 1158 } 1159 if (lf == NULL) 1160 error = ENOENT; 1161 } 1162 KLD_UNLOCK(); 1163 out: 1164 free(symstr, M_TEMP); 1165 return (error); 1166 } 1167 1168 /* 1169 * Preloaded module support 1170 */ 1171 1172 static modlist_t 1173 modlist_lookup(const char *name, int ver) 1174 { 1175 modlist_t mod; 1176 1177 TAILQ_FOREACH(mod, &found_modules, link) { 1178 if (strcmp(mod->name, name) == 0 && 1179 (ver == 0 || mod->version == ver)) 1180 return (mod); 1181 } 1182 return (NULL); 1183 } 1184 1185 static modlist_t 1186 modlist_lookup2(const char *name, struct mod_depend *verinfo) 1187 { 1188 modlist_t mod, bestmod; 1189 int ver; 1190 1191 if (verinfo == NULL) 1192 return (modlist_lookup(name, 0)); 1193 bestmod = NULL; 1194 TAILQ_FOREACH(mod, &found_modules, link) { 1195 if (strcmp(mod->name, name) != 0) 1196 continue; 1197 ver = mod->version; 1198 if (ver == verinfo->md_ver_preferred) 1199 return (mod); 1200 if (ver >= verinfo->md_ver_minimum && 1201 ver <= verinfo->md_ver_maximum && 1202 (bestmod == NULL || ver > bestmod->version)) 1203 bestmod = mod; 1204 } 1205 return (bestmod); 1206 } 1207 1208 static modlist_t 1209 modlist_newmodule(const char *modname, int version, linker_file_t container) 1210 { 1211 modlist_t mod; 1212 1213 mod = malloc(sizeof(struct modlist), M_LINKER, M_NOWAIT | M_ZERO); 1214 if (mod == NULL) 1215 panic("no memory for module list"); 1216 mod->container = container; 1217 mod->name = modname; 1218 mod->version = version; 1219 TAILQ_INSERT_TAIL(&found_modules, mod, link); 1220 return (mod); 1221 } 1222 1223 static void 1224 linker_addmodules(linker_file_t lf, struct mod_metadata **start, 1225 struct mod_metadata **stop, int preload) 1226 { 1227 struct mod_metadata *mp, **mdp; 1228 const char *modname; 1229 int ver; 1230 1231 for (mdp = start; mdp < stop; mdp++) { 1232 mp = *mdp; 1233 if (mp->md_type != MDT_VERSION) 1234 continue; 1235 modname = mp->md_cval; 1236 ver = ((struct mod_version *)mp->md_data)->mv_version; 1237 if (modlist_lookup(modname, ver) != NULL) { 1238 printf("module %s already present!\n", modname); 1239 /* XXX what can we do? this is a build error. :-( */ 1240 continue; 1241 } 1242 modlist_newmodule(modname, ver, lf); 1243 } 1244 } 1245 1246 static void 1247 linker_preload(void *arg) 1248 { 1249 caddr_t modptr; 1250 const char *modname, *nmodname; 1251 char *modtype; 1252 linker_file_t lf, nlf; 1253 linker_class_t lc; 1254 int error; 1255 linker_file_list_t loaded_files; 1256 linker_file_list_t depended_files; 1257 struct mod_metadata *mp, *nmp; 1258 struct mod_metadata **start, **stop, **mdp, **nmdp; 1259 struct mod_depend *verinfo; 1260 int nver; 1261 int resolves; 1262 modlist_t mod; 1263 struct sysinit **si_start, **si_stop; 1264 1265 TAILQ_INIT(&loaded_files); 1266 TAILQ_INIT(&depended_files); 1267 TAILQ_INIT(&found_modules); 1268 error = 0; 1269 1270 modptr = NULL; 1271 while ((modptr = preload_search_next_name(modptr)) != NULL) { 1272 modname = (char *)preload_search_info(modptr, MODINFO_NAME); 1273 modtype = (char *)preload_search_info(modptr, MODINFO_TYPE); 1274 if (modname == NULL) { 1275 printf("Preloaded module at %p does not have a" 1276 " name!\n", modptr); 1277 continue; 1278 } 1279 if (modtype == NULL) { 1280 printf("Preloaded module at %p does not have a type!\n", 1281 modptr); 1282 continue; 1283 } 1284 if (bootverbose) 1285 printf("Preloaded %s \"%s\" at %p.\n", modtype, modname, 1286 modptr); 1287 lf = NULL; 1288 TAILQ_FOREACH(lc, &classes, link) { 1289 error = LINKER_LINK_PRELOAD(lc, modname, &lf); 1290 if (!error) 1291 break; 1292 lf = NULL; 1293 } 1294 if (lf) 1295 TAILQ_INSERT_TAIL(&loaded_files, lf, loaded); 1296 } 1297 1298 /* 1299 * First get a list of stuff in the kernel. 1300 */ 1301 if (linker_file_lookup_set(linker_kernel_file, MDT_SETNAME, &start, 1302 &stop, NULL) == 0) 1303 linker_addmodules(linker_kernel_file, start, stop, 1); 1304 1305 /* 1306 * This is a once-off kinky bubble sort to resolve relocation 1307 * dependency requirements. 1308 */ 1309 restart: 1310 TAILQ_FOREACH(lf, &loaded_files, loaded) { 1311 error = linker_file_lookup_set(lf, MDT_SETNAME, &start, 1312 &stop, NULL); 1313 /* 1314 * First, look to see if we would successfully link with this 1315 * stuff. 1316 */ 1317 resolves = 1; /* unless we know otherwise */ 1318 if (!error) { 1319 for (mdp = start; mdp < stop; mdp++) { 1320 mp = *mdp; 1321 if (mp->md_type != MDT_DEPEND) 1322 continue; 1323 modname = mp->md_cval; 1324 verinfo = mp->md_data; 1325 for (nmdp = start; nmdp < stop; nmdp++) { 1326 nmp = *nmdp; 1327 if (nmp->md_type != MDT_VERSION) 1328 continue; 1329 nmodname = nmp->md_cval; 1330 if (strcmp(modname, nmodname) == 0) 1331 break; 1332 } 1333 if (nmdp < stop) /* it's a self reference */ 1334 continue; 1335 1336 /* 1337 * ok, the module isn't here yet, we 1338 * are not finished 1339 */ 1340 if (modlist_lookup2(modname, verinfo) == NULL) 1341 resolves = 0; 1342 } 1343 } 1344 /* 1345 * OK, if we found our modules, we can link. So, "provide" 1346 * the modules inside and add it to the end of the link order 1347 * list. 1348 */ 1349 if (resolves) { 1350 if (!error) { 1351 for (mdp = start; mdp < stop; mdp++) { 1352 mp = *mdp; 1353 if (mp->md_type != MDT_VERSION) 1354 continue; 1355 modname = mp->md_cval; 1356 nver = ((struct mod_version *) 1357 mp->md_data)->mv_version; 1358 if (modlist_lookup(modname, 1359 nver) != NULL) { 1360 printf("module %s already" 1361 " present!\n", modname); 1362 TAILQ_REMOVE(&loaded_files, 1363 lf, loaded); 1364 linker_file_unload(lf, 1365 LINKER_UNLOAD_FORCE); 1366 /* we changed tailq next ptr */ 1367 goto restart; 1368 } 1369 modlist_newmodule(modname, nver, lf); 1370 } 1371 } 1372 TAILQ_REMOVE(&loaded_files, lf, loaded); 1373 TAILQ_INSERT_TAIL(&depended_files, lf, loaded); 1374 /* 1375 * Since we provided modules, we need to restart the 1376 * sort so that the previous files that depend on us 1377 * have a chance. Also, we've busted the tailq next 1378 * pointer with the REMOVE. 1379 */ 1380 goto restart; 1381 } 1382 } 1383 1384 /* 1385 * At this point, we check to see what could not be resolved.. 1386 */ 1387 while ((lf = TAILQ_FIRST(&loaded_files)) != NULL) { 1388 TAILQ_REMOVE(&loaded_files, lf, loaded); 1389 printf("KLD file %s is missing dependencies\n", lf->filename); 1390 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 1391 } 1392 1393 /* 1394 * We made it. Finish off the linking in the order we determined. 1395 */ 1396 TAILQ_FOREACH_SAFE(lf, &depended_files, loaded, nlf) { 1397 if (linker_kernel_file) { 1398 linker_kernel_file->refs++; 1399 error = linker_file_add_dependency(lf, 1400 linker_kernel_file); 1401 if (error) 1402 panic("cannot add dependency"); 1403 } 1404 lf->userrefs++; /* so we can (try to) kldunload it */ 1405 error = linker_file_lookup_set(lf, MDT_SETNAME, &start, 1406 &stop, NULL); 1407 if (!error) { 1408 for (mdp = start; mdp < stop; mdp++) { 1409 mp = *mdp; 1410 if (mp->md_type != MDT_DEPEND) 1411 continue; 1412 modname = mp->md_cval; 1413 verinfo = mp->md_data; 1414 mod = modlist_lookup2(modname, verinfo); 1415 /* Don't count self-dependencies */ 1416 if (lf == mod->container) 1417 continue; 1418 mod->container->refs++; 1419 error = linker_file_add_dependency(lf, 1420 mod->container); 1421 if (error) 1422 panic("cannot add dependency"); 1423 } 1424 } 1425 /* 1426 * Now do relocation etc using the symbol search paths 1427 * established by the dependencies 1428 */ 1429 error = LINKER_LINK_PRELOAD_FINISH(lf); 1430 if (error) { 1431 TAILQ_REMOVE(&depended_files, lf, loaded); 1432 printf("KLD file %s - could not finalize loading\n", 1433 lf->filename); 1434 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 1435 continue; 1436 } 1437 linker_file_register_modules(lf); 1438 if (linker_file_lookup_set(lf, "sysinit_set", &si_start, 1439 &si_stop, NULL) == 0) 1440 sysinit_add(si_start, si_stop); 1441 linker_file_register_sysctls(lf); 1442 lf->flags |= LINKER_FILE_LINKED; 1443 } 1444 /* woohoo! we made it! */ 1445 } 1446 1447 SYSINIT(preload, SI_SUB_KLD, SI_ORDER_MIDDLE, linker_preload, 0) 1448 1449 /* 1450 * Search for a not-loaded module by name. 1451 * 1452 * Modules may be found in the following locations: 1453 * 1454 * - preloaded (result is just the module name) - on disk (result is full path 1455 * to module) 1456 * 1457 * If the module name is qualified in any way (contains path, etc.) the we 1458 * simply return a copy of it. 1459 * 1460 * The search path can be manipulated via sysctl. Note that we use the ';' 1461 * character as a separator to be consistent with the bootloader. 1462 */ 1463 1464 static char linker_hintfile[] = "linker.hints"; 1465 static char linker_path[MAXPATHLEN] = "/boot/kernel;/boot/modules"; 1466 1467 SYSCTL_STRING(_kern, OID_AUTO, module_path, CTLFLAG_RW, linker_path, 1468 sizeof(linker_path), "module load search path"); 1469 1470 TUNABLE_STR("module_path", linker_path, sizeof(linker_path)); 1471 1472 static char *linker_ext_list[] = { 1473 "", 1474 ".ko", 1475 NULL 1476 }; 1477 1478 /* 1479 * Check if file actually exists either with or without extension listed in 1480 * the linker_ext_list. (probably should be generic for the rest of the 1481 * kernel) 1482 */ 1483 static char * 1484 linker_lookup_file(const char *path, int pathlen, const char *name, 1485 int namelen, struct vattr *vap) 1486 { 1487 struct nameidata nd; 1488 struct thread *td = curthread; /* XXX */ 1489 char *result, **cpp, *sep; 1490 int error, len, extlen, reclen, flags, vfslocked; 1491 enum vtype type; 1492 1493 extlen = 0; 1494 for (cpp = linker_ext_list; *cpp; cpp++) { 1495 len = strlen(*cpp); 1496 if (len > extlen) 1497 extlen = len; 1498 } 1499 extlen++; /* trailing '\0' */ 1500 sep = (path[pathlen - 1] != '/') ? "/" : ""; 1501 1502 reclen = pathlen + strlen(sep) + namelen + extlen + 1; 1503 result = malloc(reclen, M_LINKER, M_WAITOK); 1504 for (cpp = linker_ext_list; *cpp; cpp++) { 1505 snprintf(result, reclen, "%.*s%s%.*s%s", pathlen, path, sep, 1506 namelen, name, *cpp); 1507 /* 1508 * Attempt to open the file, and return the path if 1509 * we succeed and it's a regular file. 1510 */ 1511 NDINIT(&nd, LOOKUP, FOLLOW | MPSAFE, UIO_SYSSPACE, result, td); 1512 flags = FREAD; 1513 error = vn_open(&nd, &flags, 0, NULL); 1514 if (error == 0) { 1515 vfslocked = NDHASGIANT(&nd); 1516 NDFREE(&nd, NDF_ONLY_PNBUF); 1517 type = nd.ni_vp->v_type; 1518 if (vap) 1519 VOP_GETATTR(nd.ni_vp, vap, td->td_ucred, td); 1520 VOP_UNLOCK(nd.ni_vp, 0, td); 1521 vn_close(nd.ni_vp, FREAD, td->td_ucred, td); 1522 VFS_UNLOCK_GIANT(vfslocked); 1523 if (type == VREG) 1524 return (result); 1525 } 1526 } 1527 free(result, M_LINKER); 1528 return (NULL); 1529 } 1530 1531 #define INT_ALIGN(base, ptr) ptr = \ 1532 (base) + (((ptr) - (base) + sizeof(int) - 1) & ~(sizeof(int) - 1)) 1533 1534 /* 1535 * Lookup KLD which contains requested module in the "linker.hints" file. If 1536 * version specification is available, then try to find the best KLD. 1537 * Otherwise just find the latest one. 1538 */ 1539 static char * 1540 linker_hints_lookup(const char *path, int pathlen, const char *modname, 1541 int modnamelen, struct mod_depend *verinfo) 1542 { 1543 struct thread *td = curthread; /* XXX */ 1544 struct ucred *cred = td ? td->td_ucred : NULL; 1545 struct nameidata nd; 1546 struct vattr vattr, mattr; 1547 u_char *hints = NULL; 1548 u_char *cp, *recptr, *bufend, *result, *best, *pathbuf, *sep; 1549 int error, ival, bestver, *intp, reclen, found, flags, clen, blen; 1550 int vfslocked = 0; 1551 1552 result = NULL; 1553 bestver = found = 0; 1554 1555 sep = (path[pathlen - 1] != '/') ? "/" : ""; 1556 reclen = imax(modnamelen, strlen(linker_hintfile)) + pathlen + 1557 strlen(sep) + 1; 1558 pathbuf = malloc(reclen, M_LINKER, M_WAITOK); 1559 snprintf(pathbuf, reclen, "%.*s%s%s", pathlen, path, sep, 1560 linker_hintfile); 1561 1562 NDINIT(&nd, LOOKUP, NOFOLLOW | MPSAFE, UIO_SYSSPACE, pathbuf, td); 1563 flags = FREAD; 1564 error = vn_open(&nd, &flags, 0, NULL); 1565 if (error) 1566 goto bad; 1567 vfslocked = NDHASGIANT(&nd); 1568 NDFREE(&nd, NDF_ONLY_PNBUF); 1569 if (nd.ni_vp->v_type != VREG) 1570 goto bad; 1571 best = cp = NULL; 1572 error = VOP_GETATTR(nd.ni_vp, &vattr, cred, td); 1573 if (error) 1574 goto bad; 1575 /* 1576 * XXX: we need to limit this number to some reasonable value 1577 */ 1578 if (vattr.va_size > 100 * 1024) { 1579 printf("hints file too large %ld\n", (long)vattr.va_size); 1580 goto bad; 1581 } 1582 hints = malloc(vattr.va_size, M_TEMP, M_WAITOK); 1583 if (hints == NULL) 1584 goto bad; 1585 error = vn_rdwr(UIO_READ, nd.ni_vp, (caddr_t)hints, vattr.va_size, 0, 1586 UIO_SYSSPACE, IO_NODELOCKED, cred, NOCRED, &reclen, td); 1587 if (error) 1588 goto bad; 1589 VOP_UNLOCK(nd.ni_vp, 0, td); 1590 vn_close(nd.ni_vp, FREAD, cred, td); 1591 VFS_UNLOCK_GIANT(vfslocked); 1592 nd.ni_vp = NULL; 1593 if (reclen != 0) { 1594 printf("can't read %d\n", reclen); 1595 goto bad; 1596 } 1597 intp = (int *)hints; 1598 ival = *intp++; 1599 if (ival != LINKER_HINTS_VERSION) { 1600 printf("hints file version mismatch %d\n", ival); 1601 goto bad; 1602 } 1603 bufend = hints + vattr.va_size; 1604 recptr = (u_char *)intp; 1605 clen = blen = 0; 1606 while (recptr < bufend && !found) { 1607 intp = (int *)recptr; 1608 reclen = *intp++; 1609 ival = *intp++; 1610 cp = (char *)intp; 1611 switch (ival) { 1612 case MDT_VERSION: 1613 clen = *cp++; 1614 if (clen != modnamelen || bcmp(cp, modname, clen) != 0) 1615 break; 1616 cp += clen; 1617 INT_ALIGN(hints, cp); 1618 ival = *(int *)cp; 1619 cp += sizeof(int); 1620 clen = *cp++; 1621 if (verinfo == NULL || 1622 ival == verinfo->md_ver_preferred) { 1623 found = 1; 1624 break; 1625 } 1626 if (ival >= verinfo->md_ver_minimum && 1627 ival <= verinfo->md_ver_maximum && 1628 ival > bestver) { 1629 bestver = ival; 1630 best = cp; 1631 blen = clen; 1632 } 1633 break; 1634 default: 1635 break; 1636 } 1637 recptr += reclen + sizeof(int); 1638 } 1639 /* 1640 * Finally check if KLD is in the place 1641 */ 1642 if (found) 1643 result = linker_lookup_file(path, pathlen, cp, clen, &mattr); 1644 else if (best) 1645 result = linker_lookup_file(path, pathlen, best, blen, &mattr); 1646 1647 /* 1648 * KLD is newer than hints file. What we should do now? 1649 */ 1650 if (result && timespeccmp(&mattr.va_mtime, &vattr.va_mtime, >)) 1651 printf("warning: KLD '%s' is newer than the linker.hints" 1652 " file\n", result); 1653 bad: 1654 free(pathbuf, M_LINKER); 1655 if (hints) 1656 free(hints, M_TEMP); 1657 if (nd.ni_vp != NULL) { 1658 VOP_UNLOCK(nd.ni_vp, 0, td); 1659 vn_close(nd.ni_vp, FREAD, cred, td); 1660 VFS_UNLOCK_GIANT(vfslocked); 1661 } 1662 /* 1663 * If nothing found or hints is absent - fallback to the old 1664 * way by using "kldname[.ko]" as module name. 1665 */ 1666 if (!found && !bestver && result == NULL) 1667 result = linker_lookup_file(path, pathlen, modname, 1668 modnamelen, NULL); 1669 return (result); 1670 } 1671 1672 /* 1673 * Lookup KLD which contains requested module in the all directories. 1674 */ 1675 static char * 1676 linker_search_module(const char *modname, int modnamelen, 1677 struct mod_depend *verinfo) 1678 { 1679 char *cp, *ep, *result; 1680 1681 /* 1682 * traverse the linker path 1683 */ 1684 for (cp = linker_path; *cp; cp = ep + 1) { 1685 /* find the end of this component */ 1686 for (ep = cp; (*ep != 0) && (*ep != ';'); ep++); 1687 result = linker_hints_lookup(cp, ep - cp, modname, 1688 modnamelen, verinfo); 1689 if (result != NULL) 1690 return (result); 1691 if (*ep == 0) 1692 break; 1693 } 1694 return (NULL); 1695 } 1696 1697 /* 1698 * Search for module in all directories listed in the linker_path. 1699 */ 1700 static char * 1701 linker_search_kld(const char *name) 1702 { 1703 char *cp, *ep, *result; 1704 int len; 1705 1706 /* qualified at all? */ 1707 if (index(name, '/')) 1708 return (linker_strdup(name)); 1709 1710 /* traverse the linker path */ 1711 len = strlen(name); 1712 for (ep = linker_path; *ep; ep++) { 1713 cp = ep; 1714 /* find the end of this component */ 1715 for (; *ep != 0 && *ep != ';'; ep++); 1716 result = linker_lookup_file(cp, ep - cp, name, len, NULL); 1717 if (result != NULL) 1718 return (result); 1719 } 1720 return (NULL); 1721 } 1722 1723 static const char * 1724 linker_basename(const char *path) 1725 { 1726 const char *filename; 1727 1728 filename = rindex(path, '/'); 1729 if (filename == NULL) 1730 return path; 1731 if (filename[1]) 1732 filename++; 1733 return (filename); 1734 } 1735 1736 #ifdef HWPMC_HOOKS 1737 1738 struct hwpmc_context { 1739 int nobjects; 1740 int nmappings; 1741 struct pmckern_map_in *kobase; 1742 }; 1743 1744 static int 1745 linker_hwpmc_list_object(linker_file_t lf, void *arg) 1746 { 1747 struct hwpmc_context *hc; 1748 1749 hc = arg; 1750 1751 /* If we run out of mappings, fail. */ 1752 if (hc->nobjects >= hc->nmappings) 1753 return (1); 1754 1755 /* Save the info for this linker file. */ 1756 hc->kobase[hc->nobjects].pm_file = lf->filename; 1757 hc->kobase[hc->nobjects].pm_address = (uintptr_t)lf->address; 1758 hc->nobjects++; 1759 return (0); 1760 } 1761 1762 /* 1763 * Inform hwpmc about the set of kernel modules currently loaded. 1764 */ 1765 void * 1766 linker_hwpmc_list_objects(void) 1767 { 1768 struct hwpmc_context hc; 1769 1770 hc.nmappings = 15; /* a reasonable default */ 1771 1772 retry: 1773 /* allocate nmappings+1 entries */ 1774 MALLOC(hc.kobase, struct pmckern_map_in *, 1775 (hc.nmappings + 1) * sizeof(struct pmckern_map_in), M_LINKER, 1776 M_WAITOK | M_ZERO); 1777 1778 hc.nobjects = 0; 1779 if (linker_file_foreach(linker_hwpmc_list_object, &hc) != 0) { 1780 hc.nmappings = hc.nobjects; 1781 FREE(hc.kobase, M_LINKER); 1782 goto retry; 1783 } 1784 1785 KASSERT(hc.nobjects > 0, ("linker_hpwmc_list_objects: no kernel " 1786 "objects?")); 1787 1788 /* The last entry of the malloced area comprises of all zeros. */ 1789 KASSERT(hc.kobase[hc.nobjects].pm_file == NULL, 1790 ("linker_hwpmc_list_objects: last object not NULL")); 1791 1792 return ((void *)hc.kobase); 1793 } 1794 #endif 1795 1796 /* 1797 * Find a file which contains given module and load it, if "parent" is not 1798 * NULL, register a reference to it. 1799 */ 1800 static int 1801 linker_load_module(const char *kldname, const char *modname, 1802 struct linker_file *parent, struct mod_depend *verinfo, 1803 struct linker_file **lfpp) 1804 { 1805 linker_file_t lfdep; 1806 const char *filename; 1807 char *pathname; 1808 int error; 1809 1810 KLD_LOCK_ASSERT(); 1811 if (modname == NULL) { 1812 /* 1813 * We have to load KLD 1814 */ 1815 KASSERT(verinfo == NULL, ("linker_load_module: verinfo" 1816 " is not NULL")); 1817 pathname = linker_search_kld(kldname); 1818 } else { 1819 if (modlist_lookup2(modname, verinfo) != NULL) 1820 return (EEXIST); 1821 if (kldname != NULL) 1822 pathname = linker_strdup(kldname); 1823 else if (rootvnode == NULL) 1824 pathname = NULL; 1825 else 1826 /* 1827 * Need to find a KLD with required module 1828 */ 1829 pathname = linker_search_module(modname, 1830 strlen(modname), verinfo); 1831 } 1832 if (pathname == NULL) 1833 return (ENOENT); 1834 1835 /* 1836 * Can't load more than one file with the same basename XXX: 1837 * Actually it should be possible to have multiple KLDs with 1838 * the same basename but different path because they can 1839 * provide different versions of the same modules. 1840 */ 1841 filename = linker_basename(pathname); 1842 if (linker_find_file_by_name(filename)) 1843 error = EEXIST; 1844 else do { 1845 error = linker_load_file(pathname, &lfdep); 1846 if (error) 1847 break; 1848 if (modname && verinfo && 1849 modlist_lookup2(modname, verinfo) == NULL) { 1850 linker_file_unload(lfdep, LINKER_UNLOAD_FORCE); 1851 error = ENOENT; 1852 break; 1853 } 1854 if (parent) { 1855 error = linker_file_add_dependency(parent, lfdep); 1856 if (error) 1857 break; 1858 } 1859 if (lfpp) 1860 *lfpp = lfdep; 1861 } while (0); 1862 free(pathname, M_LINKER); 1863 return (error); 1864 } 1865 1866 /* 1867 * This routine is responsible for finding dependencies of userland initiated 1868 * kldload(2)'s of files. 1869 */ 1870 int 1871 linker_load_dependencies(linker_file_t lf) 1872 { 1873 linker_file_t lfdep; 1874 struct mod_metadata **start, **stop, **mdp, **nmdp; 1875 struct mod_metadata *mp, *nmp; 1876 struct mod_depend *verinfo; 1877 modlist_t mod; 1878 const char *modname, *nmodname; 1879 int ver, error = 0, count; 1880 1881 /* 1882 * All files are dependant on /kernel. 1883 */ 1884 KLD_LOCK_ASSERT(); 1885 if (linker_kernel_file) { 1886 linker_kernel_file->refs++; 1887 error = linker_file_add_dependency(lf, linker_kernel_file); 1888 if (error) 1889 return (error); 1890 } 1891 if (linker_file_lookup_set(lf, MDT_SETNAME, &start, &stop, 1892 &count) != 0) 1893 return (0); 1894 for (mdp = start; mdp < stop; mdp++) { 1895 mp = *mdp; 1896 if (mp->md_type != MDT_VERSION) 1897 continue; 1898 modname = mp->md_cval; 1899 ver = ((struct mod_version *)mp->md_data)->mv_version; 1900 mod = modlist_lookup(modname, ver); 1901 if (mod != NULL) { 1902 printf("interface %s.%d already present in the KLD" 1903 " '%s'!\n", modname, ver, 1904 mod->container->filename); 1905 return (EEXIST); 1906 } 1907 } 1908 1909 for (mdp = start; mdp < stop; mdp++) { 1910 mp = *mdp; 1911 if (mp->md_type != MDT_DEPEND) 1912 continue; 1913 modname = mp->md_cval; 1914 verinfo = mp->md_data; 1915 nmodname = NULL; 1916 for (nmdp = start; nmdp < stop; nmdp++) { 1917 nmp = *nmdp; 1918 if (nmp->md_type != MDT_VERSION) 1919 continue; 1920 nmodname = nmp->md_cval; 1921 if (strcmp(modname, nmodname) == 0) 1922 break; 1923 } 1924 if (nmdp < stop)/* early exit, it's a self reference */ 1925 continue; 1926 mod = modlist_lookup2(modname, verinfo); 1927 if (mod) { /* woohoo, it's loaded already */ 1928 lfdep = mod->container; 1929 lfdep->refs++; 1930 error = linker_file_add_dependency(lf, lfdep); 1931 if (error) 1932 break; 1933 continue; 1934 } 1935 error = linker_load_module(NULL, modname, lf, verinfo, NULL); 1936 if (error) { 1937 printf("KLD %s: depends on %s - not available\n", 1938 lf->filename, modname); 1939 break; 1940 } 1941 } 1942 1943 if (error) 1944 return (error); 1945 linker_addmodules(lf, start, stop, 0); 1946 return (error); 1947 } 1948 1949 static int 1950 sysctl_kern_function_list_iterate(const char *name, void *opaque) 1951 { 1952 struct sysctl_req *req; 1953 1954 req = opaque; 1955 return (SYSCTL_OUT(req, name, strlen(name) + 1)); 1956 } 1957 1958 /* 1959 * Export a nul-separated, double-nul-terminated list of all function names 1960 * in the kernel. 1961 */ 1962 static int 1963 sysctl_kern_function_list(SYSCTL_HANDLER_ARGS) 1964 { 1965 linker_file_t lf; 1966 int error; 1967 1968 #ifdef MAC 1969 error = mac_check_kld_stat(req->td->td_ucred); 1970 if (error) 1971 return (error); 1972 #endif 1973 error = sysctl_wire_old_buffer(req, 0); 1974 if (error != 0) 1975 return (error); 1976 KLD_LOCK(); 1977 TAILQ_FOREACH(lf, &linker_files, link) { 1978 error = LINKER_EACH_FUNCTION_NAME(lf, 1979 sysctl_kern_function_list_iterate, req); 1980 if (error) { 1981 KLD_UNLOCK(); 1982 return (error); 1983 } 1984 } 1985 KLD_UNLOCK(); 1986 return (SYSCTL_OUT(req, "", 1)); 1987 } 1988 1989 SYSCTL_PROC(_kern, OID_AUTO, function_list, CTLFLAG_RD, 1990 NULL, 0, sysctl_kern_function_list, "", "kernel function list");
Cache object: 4b5da06315782aa46526cc9d6bb4e229
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