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: src/sys/kern/kern_linker.c,v 1.113.2.3 2005/11/04 17:18:29 jdp Exp $"); 29 30 #include "opt_ddb.h" 31 #include "opt_mac.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/proc.h> 40 #include <sys/lock.h> 41 #include <sys/mutex.h> 42 #include <sys/sx.h> 43 #include <sys/mac.h> 44 #include <sys/module.h> 45 #include <sys/linker.h> 46 #include <sys/fcntl.h> 47 #include <sys/libkern.h> 48 #include <sys/namei.h> 49 #include <sys/vnode.h> 50 #include <sys/sysctl.h> 51 52 #include "linker_if.h" 53 54 #ifdef KLD_DEBUG 55 int kld_debug = 0; 56 #endif 57 58 /* 59 * static char *linker_search_path(const char *name, struct mod_depend 60 * *verinfo); 61 */ 62 static const char *linker_basename(const char *path); 63 64 /* Metadata from the static kernel */ 65 SET_DECLARE(modmetadata_set, struct mod_metadata); 66 67 MALLOC_DEFINE(M_LINKER, "linker", "kernel linker"); 68 69 linker_file_t linker_kernel_file; 70 71 static struct mtx kld_mtx; /* kernel linker mutex */ 72 73 static linker_class_list_t classes; 74 static linker_file_list_t linker_files; 75 static int next_file_id = 1; 76 static int linker_no_more_classes = 0; 77 78 #define LINKER_GET_NEXT_FILE_ID(a) do { \ 79 linker_file_t lftmp; \ 80 \ 81 retry: \ 82 mtx_lock(&kld_mtx); \ 83 TAILQ_FOREACH(lftmp, &linker_files, link) { \ 84 if (next_file_id == lftmp->id) { \ 85 next_file_id++; \ 86 mtx_unlock(&kld_mtx); \ 87 goto retry; \ 88 } \ 89 } \ 90 (a) = next_file_id; \ 91 mtx_unlock(&kld_mtx); /* Hold for safe read of id variable */ \ 92 } while(0) 93 94 95 /* XXX wrong name; we're looking at version provision tags here, not modules */ 96 typedef TAILQ_HEAD(, modlist) modlisthead_t; 97 struct modlist { 98 TAILQ_ENTRY(modlist) link; /* chain together all modules */ 99 linker_file_t container; 100 const char *name; 101 int version; 102 }; 103 typedef struct modlist *modlist_t; 104 static modlisthead_t found_modules; 105 106 static modlist_t modlist_lookup2(const char *name, 107 struct mod_depend *verinfo); 108 109 static char * 110 linker_strdup(const char *str) 111 { 112 char *result; 113 114 if ((result = malloc((strlen(str) + 1), M_LINKER, M_WAITOK)) != NULL) 115 strcpy(result, str); 116 return (result); 117 } 118 119 static void 120 linker_init(void *arg) 121 { 122 123 mtx_init(&kld_mtx, "kernel linker", NULL, MTX_DEF); 124 TAILQ_INIT(&classes); 125 TAILQ_INIT(&linker_files); 126 } 127 128 SYSINIT(linker, SI_SUB_KLD, SI_ORDER_FIRST, linker_init, 0) 129 130 static void 131 linker_stop_class_add(void *arg) 132 { 133 134 linker_no_more_classes = 1; 135 } 136 137 SYSINIT(linker_class, SI_SUB_KLD, SI_ORDER_ANY, linker_stop_class_add, NULL) 138 139 int 140 linker_add_class(linker_class_t lc) 141 { 142 143 /* 144 * We disallow any class registration passt SI_ORDER_ANY 145 * of SI_SUB_KLD. 146 */ 147 if (linker_no_more_classes == 1) 148 return (EPERM); 149 kobj_class_compile((kobj_class_t) lc); 150 ((kobj_class_t)lc)->refs++; /* prevent ops being freed */ 151 TAILQ_INSERT_TAIL(&classes, lc, link); 152 return (0); 153 } 154 155 static void 156 linker_file_sysinit(linker_file_t lf) 157 { 158 struct sysinit **start, **stop, **sipp, **xipp, *save; 159 160 KLD_DPF(FILE, ("linker_file_sysinit: calling SYSINITs for %s\n", 161 lf->filename)); 162 163 if (linker_file_lookup_set(lf, "sysinit_set", &start, &stop, NULL) != 0) 164 return; 165 /* 166 * Perform a bubble sort of the system initialization objects by 167 * their subsystem (primary key) and order (secondary key). 168 * 169 * Since some things care about execution order, this is the operation 170 * which ensures continued function. 171 */ 172 for (sipp = start; sipp < stop; sipp++) { 173 for (xipp = sipp + 1; xipp < stop; xipp++) { 174 if ((*sipp)->subsystem < (*xipp)->subsystem || 175 ((*sipp)->subsystem == (*xipp)->subsystem && 176 (*sipp)->order <= (*xipp)->order)) 177 continue; /* skip */ 178 save = *sipp; 179 *sipp = *xipp; 180 *xipp = save; 181 } 182 } 183 184 /* 185 * Traverse the (now) ordered list of system initialization tasks. 186 * Perform each task, and continue on to the next task. 187 */ 188 for (sipp = start; sipp < stop; sipp++) { 189 if ((*sipp)->subsystem == SI_SUB_DUMMY) 190 continue; /* skip dummy task(s) */ 191 192 /* Call function */ 193 (*((*sipp)->func)) ((*sipp)->udata); 194 } 195 } 196 197 static void 198 linker_file_sysuninit(linker_file_t lf) 199 { 200 struct sysinit **start, **stop, **sipp, **xipp, *save; 201 202 KLD_DPF(FILE, ("linker_file_sysuninit: calling SYSUNINITs for %s\n", 203 lf->filename)); 204 205 if (linker_file_lookup_set(lf, "sysuninit_set", &start, &stop, 206 NULL) != 0) 207 return; 208 209 /* 210 * Perform a reverse bubble sort of the system initialization objects 211 * by their subsystem (primary key) and order (secondary key). 212 * 213 * Since some things care about execution order, this is the operation 214 * which ensures continued function. 215 */ 216 for (sipp = start; sipp < stop; sipp++) { 217 for (xipp = sipp + 1; xipp < stop; xipp++) { 218 if ((*sipp)->subsystem > (*xipp)->subsystem || 219 ((*sipp)->subsystem == (*xipp)->subsystem && 220 (*sipp)->order >= (*xipp)->order)) 221 continue; /* skip */ 222 save = *sipp; 223 *sipp = *xipp; 224 *xipp = save; 225 } 226 } 227 228 /* 229 * Traverse the (now) ordered list of system initialization tasks. 230 * Perform each task, and continue on to the next task. 231 */ 232 for (sipp = start; sipp < stop; sipp++) { 233 if ((*sipp)->subsystem == SI_SUB_DUMMY) 234 continue; /* skip dummy task(s) */ 235 236 /* Call function */ 237 (*((*sipp)->func)) ((*sipp)->udata); 238 } 239 } 240 241 static void 242 linker_file_register_sysctls(linker_file_t lf) 243 { 244 struct sysctl_oid **start, **stop, **oidp; 245 246 KLD_DPF(FILE, 247 ("linker_file_register_sysctls: registering SYSCTLs for %s\n", 248 lf->filename)); 249 250 if (linker_file_lookup_set(lf, "sysctl_set", &start, &stop, NULL) != 0) 251 return; 252 253 for (oidp = start; oidp < stop; oidp++) 254 sysctl_register_oid(*oidp); 255 } 256 257 static void 258 linker_file_unregister_sysctls(linker_file_t lf) 259 { 260 struct sysctl_oid **start, **stop, **oidp; 261 262 KLD_DPF(FILE, ("linker_file_unregister_sysctls: registering SYSCTLs" 263 " for %s\n", lf->filename)); 264 265 if (linker_file_lookup_set(lf, "sysctl_set", &start, &stop, NULL) != 0) 266 return; 267 268 for (oidp = start; oidp < stop; oidp++) 269 sysctl_unregister_oid(*oidp); 270 } 271 272 static int 273 linker_file_register_modules(linker_file_t lf) 274 { 275 struct mod_metadata **start, **stop, **mdp; 276 const moduledata_t *moddata; 277 int first_error, error; 278 279 KLD_DPF(FILE, ("linker_file_register_modules: registering modules" 280 " in %s\n", lf->filename)); 281 282 if (linker_file_lookup_set(lf, "modmetadata_set", &start, 283 &stop, 0) != 0) { 284 /* 285 * This fallback should be unnecessary, but if we get booted 286 * from boot2 instead of loader and we are missing our 287 * metadata then we have to try the best we can. 288 */ 289 if (lf == linker_kernel_file) { 290 start = SET_BEGIN(modmetadata_set); 291 stop = SET_LIMIT(modmetadata_set); 292 } else 293 return (0); 294 } 295 first_error = 0; 296 for (mdp = start; mdp < stop; mdp++) { 297 if ((*mdp)->md_type != MDT_MODULE) 298 continue; 299 moddata = (*mdp)->md_data; 300 KLD_DPF(FILE, ("Registering module %s in %s\n", 301 moddata->name, lf->filename)); 302 error = module_register(moddata, lf); 303 if (error) { 304 printf("Module %s failed to register: %d\n", 305 moddata->name, error); 306 if (first_error == 0) 307 first_error = error; 308 } 309 } 310 return (first_error); 311 } 312 313 static void 314 linker_init_kernel_modules(void) 315 { 316 317 linker_file_register_modules(linker_kernel_file); 318 } 319 320 SYSINIT(linker_kernel, SI_SUB_KLD, SI_ORDER_ANY, linker_init_kernel_modules, 0) 321 322 static int 323 linker_load_file(const char *filename, linker_file_t *result) 324 { 325 linker_class_t lc; 326 linker_file_t lf; 327 int foundfile, error = 0; 328 329 /* Refuse to load modules if securelevel raised */ 330 if (securelevel > 0) 331 return (EPERM); 332 333 lf = linker_find_file_by_name(filename); 334 if (lf) { 335 KLD_DPF(FILE, ("linker_load_file: file %s is already loaded," 336 " incrementing refs\n", filename)); 337 *result = lf; 338 lf->refs++; 339 goto out; 340 } 341 lf = NULL; 342 foundfile = 0; 343 344 /* 345 * We do not need to protect (lock) classes here because there is 346 * no class registration past startup (SI_SUB_KLD, SI_ORDER_ANY) 347 * and there is no class deregistration mechanism at this time. 348 */ 349 TAILQ_FOREACH(lc, &classes, link) { 350 KLD_DPF(FILE, ("linker_load_file: trying to load %s\n", 351 filename)); 352 error = LINKER_LOAD_FILE(lc, filename, &lf); 353 /* 354 * If we got something other than ENOENT, then it exists but 355 * we cannot load it for some other reason. 356 */ 357 if (error != ENOENT) 358 foundfile = 1; 359 if (lf) { 360 error = linker_file_register_modules(lf); 361 if (error == EEXIST) { 362 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 363 goto out; 364 } 365 linker_file_register_sysctls(lf); 366 linker_file_sysinit(lf); 367 lf->flags |= LINKER_FILE_LINKED; 368 *result = lf; 369 error = 0; 370 goto out; 371 } 372 } 373 /* 374 * Less than ideal, but tells the user whether it failed to load or 375 * the module was not found. 376 */ 377 if (foundfile) { 378 /* 379 * Format not recognized or otherwise unloadable. 380 * When loading a module that is statically built into 381 * the kernel EEXIST percolates back up as the return 382 * value. Preserve this so that apps like sysinstall 383 * can recognize this special case and not post bogus 384 * dialog boxes. 385 */ 386 if (error != EEXIST) 387 error = ENOEXEC; 388 } else 389 error = ENOENT; /* Nothing found */ 390 out: 391 return (error); 392 } 393 394 int 395 linker_reference_module(const char *modname, struct mod_depend *verinfo, 396 linker_file_t *result) 397 { 398 modlist_t mod; 399 400 if ((mod = modlist_lookup2(modname, verinfo)) != NULL) { 401 *result = mod->container; 402 (*result)->refs++; 403 return (0); 404 } 405 406 return (linker_load_module(NULL, modname, NULL, verinfo, result)); 407 } 408 409 linker_file_t 410 linker_find_file_by_name(const char *filename) 411 { 412 linker_file_t lf = 0; 413 char *koname; 414 415 koname = malloc(strlen(filename) + 4, M_LINKER, M_WAITOK); 416 if (koname == NULL) 417 goto out; 418 sprintf(koname, "%s.ko", filename); 419 420 mtx_lock(&kld_mtx); 421 TAILQ_FOREACH(lf, &linker_files, link) { 422 if (strcmp(lf->filename, koname) == 0) 423 break; 424 if (strcmp(lf->filename, filename) == 0) 425 break; 426 } 427 mtx_unlock(&kld_mtx); 428 out: 429 if (koname) 430 free(koname, M_LINKER); 431 return (lf); 432 } 433 434 linker_file_t 435 linker_find_file_by_id(int fileid) 436 { 437 linker_file_t lf = 0; 438 439 mtx_lock(&kld_mtx); 440 TAILQ_FOREACH(lf, &linker_files, link) 441 if (lf->id == fileid) 442 break; 443 mtx_unlock(&kld_mtx); 444 return (lf); 445 } 446 447 linker_file_t 448 linker_make_file(const char *pathname, linker_class_t lc) 449 { 450 linker_file_t lf; 451 const char *filename; 452 453 lf = NULL; 454 filename = linker_basename(pathname); 455 456 KLD_DPF(FILE, ("linker_make_file: new file, filename=%s\n", filename)); 457 lf = (linker_file_t)kobj_create((kobj_class_t)lc, M_LINKER, M_WAITOK); 458 if (lf == NULL) 459 goto out; 460 lf->refs = 1; 461 lf->userrefs = 0; 462 lf->flags = 0; 463 lf->filename = linker_strdup(filename); 464 LINKER_GET_NEXT_FILE_ID(lf->id); 465 lf->ndeps = 0; 466 lf->deps = NULL; 467 STAILQ_INIT(&lf->common); 468 TAILQ_INIT(&lf->modules); 469 mtx_lock(&kld_mtx); 470 TAILQ_INSERT_TAIL(&linker_files, lf, link); 471 mtx_unlock(&kld_mtx); 472 out: 473 return (lf); 474 } 475 476 int 477 linker_file_unload(linker_file_t file, int flags) 478 { 479 module_t mod, next; 480 modlist_t ml, nextml; 481 struct common_symbol *cp; 482 int error, i; 483 484 error = 0; 485 486 /* Refuse to unload modules if securelevel raised. */ 487 if (securelevel > 0) 488 return (EPERM); 489 #ifdef MAC 490 error = mac_check_kld_unload(curthread->td_ucred); 491 if (error) 492 return (error); 493 #endif 494 495 KLD_DPF(FILE, ("linker_file_unload: lf->refs=%d\n", file->refs)); 496 if (file->refs == 1) { 497 KLD_DPF(FILE, ("linker_file_unload: file is unloading," 498 " informing modules\n")); 499 500 /* 501 * Inform any modules associated with this file. 502 */ 503 MOD_XLOCK; 504 for (mod = TAILQ_FIRST(&file->modules); mod; mod = next) { 505 next = module_getfnext(mod); 506 MOD_XUNLOCK; 507 508 /* 509 * Give the module a chance to veto the unload. 510 */ 511 if ((error = module_unload(mod, flags)) != 0) { 512 KLD_DPF(FILE, ("linker_file_unload: module %p" 513 " vetoes unload\n", mod)); 514 goto out; 515 } else 516 MOD_XLOCK; 517 module_release(mod); 518 } 519 MOD_XUNLOCK; 520 } 521 file->refs--; 522 if (file->refs > 0) { 523 goto out; 524 } 525 for (ml = TAILQ_FIRST(&found_modules); ml; ml = nextml) { 526 nextml = TAILQ_NEXT(ml, link); 527 if (ml->container == file) { 528 TAILQ_REMOVE(&found_modules, ml, link); 529 free(ml, M_LINKER); 530 } 531 } 532 533 /* 534 * Don't try to run SYSUNINITs if we are unloaded due to a 535 * link error. 536 */ 537 if (file->flags & LINKER_FILE_LINKED) { 538 linker_file_sysuninit(file); 539 linker_file_unregister_sysctls(file); 540 } 541 mtx_lock(&kld_mtx); 542 TAILQ_REMOVE(&linker_files, file, link); 543 mtx_unlock(&kld_mtx); 544 545 if (file->deps) { 546 for (i = 0; i < file->ndeps; i++) 547 linker_file_unload(file->deps[i], flags); 548 free(file->deps, M_LINKER); 549 file->deps = NULL; 550 } 551 for (cp = STAILQ_FIRST(&file->common); cp; 552 cp = STAILQ_FIRST(&file->common)) { 553 STAILQ_REMOVE(&file->common, cp, common_symbol, link); 554 free(cp, M_LINKER); 555 } 556 557 LINKER_UNLOAD(file); 558 if (file->filename) { 559 free(file->filename, M_LINKER); 560 file->filename = NULL; 561 } 562 kobj_delete((kobj_t) file, M_LINKER); 563 out: 564 return (error); 565 } 566 567 int 568 linker_file_add_dependency(linker_file_t file, linker_file_t dep) 569 { 570 linker_file_t *newdeps; 571 572 newdeps = malloc((file->ndeps + 1) * sizeof(linker_file_t *), 573 M_LINKER, M_WAITOK | M_ZERO); 574 if (newdeps == NULL) 575 return (ENOMEM); 576 577 if (file->deps) { 578 bcopy(file->deps, newdeps, 579 file->ndeps * sizeof(linker_file_t *)); 580 free(file->deps, M_LINKER); 581 } 582 file->deps = newdeps; 583 file->deps[file->ndeps] = dep; 584 file->ndeps++; 585 return (0); 586 } 587 588 /* 589 * Locate a linker set and its contents. This is a helper function to avoid 590 * linker_if.h exposure elsewhere. Note: firstp and lastp are really void *** 591 */ 592 int 593 linker_file_lookup_set(linker_file_t file, const char *name, 594 void *firstp, void *lastp, int *countp) 595 { 596 597 return (LINKER_LOOKUP_SET(file, name, firstp, lastp, countp)); 598 } 599 600 caddr_t 601 linker_file_lookup_symbol(linker_file_t file, const char *name, int deps) 602 { 603 c_linker_sym_t sym; 604 linker_symval_t symval; 605 caddr_t address; 606 size_t common_size = 0; 607 int i; 608 609 KLD_DPF(SYM, ("linker_file_lookup_symbol: file=%p, name=%s, deps=%d\n", 610 file, name, deps)); 611 612 if (LINKER_LOOKUP_SYMBOL(file, name, &sym) == 0) { 613 LINKER_SYMBOL_VALUES(file, sym, &symval); 614 if (symval.value == 0) 615 /* 616 * For commons, first look them up in the 617 * dependencies and only allocate space if not found 618 * there. 619 */ 620 common_size = symval.size; 621 else { 622 KLD_DPF(SYM, ("linker_file_lookup_symbol: symbol" 623 ".value=%p\n", symval.value)); 624 return (symval.value); 625 } 626 } 627 if (deps) { 628 for (i = 0; i < file->ndeps; i++) { 629 address = linker_file_lookup_symbol(file->deps[i], 630 name, 0); 631 if (address) { 632 KLD_DPF(SYM, ("linker_file_lookup_symbol:" 633 " deps value=%p\n", address)); 634 return (address); 635 } 636 } 637 } 638 if (common_size > 0) { 639 /* 640 * This is a common symbol which was not found in the 641 * dependencies. We maintain a simple common symbol table in 642 * the file object. 643 */ 644 struct common_symbol *cp; 645 646 STAILQ_FOREACH(cp, &file->common, link) { 647 if (strcmp(cp->name, name) == 0) { 648 KLD_DPF(SYM, ("linker_file_lookup_symbol:" 649 " old common value=%p\n", cp->address)); 650 return (cp->address); 651 } 652 } 653 /* 654 * Round the symbol size up to align. 655 */ 656 common_size = (common_size + sizeof(int) - 1) & -sizeof(int); 657 cp = malloc(sizeof(struct common_symbol) 658 + common_size + strlen(name) + 1, M_LINKER, 659 M_WAITOK | M_ZERO); 660 if (cp == NULL) { 661 KLD_DPF(SYM, ("linker_file_lookup_symbol: nomem\n")); 662 return (0); 663 } 664 cp->address = (caddr_t)(cp + 1); 665 cp->name = cp->address + common_size; 666 strcpy(cp->name, name); 667 bzero(cp->address, common_size); 668 STAILQ_INSERT_TAIL(&file->common, cp, link); 669 670 KLD_DPF(SYM, ("linker_file_lookup_symbol: new common" 671 " value=%p\n", cp->address)); 672 return (cp->address); 673 } 674 KLD_DPF(SYM, ("linker_file_lookup_symbol: fail\n")); 675 return (0); 676 } 677 678 #ifdef DDB 679 /* 680 * DDB Helpers. DDB has to look across multiple files with their own symbol 681 * tables and string tables. 682 * 683 * Note that we do not obey list locking protocols here. We really don't need 684 * DDB to hang because somebody's got the lock held. We'll take the chance 685 * that the files list is inconsistant instead. 686 */ 687 688 int 689 linker_ddb_lookup(const char *symstr, c_linker_sym_t *sym) 690 { 691 linker_file_t lf; 692 693 TAILQ_FOREACH(lf, &linker_files, link) { 694 if (LINKER_LOOKUP_SYMBOL(lf, symstr, sym) == 0) 695 return (0); 696 } 697 return (ENOENT); 698 } 699 700 int 701 linker_ddb_search_symbol(caddr_t value, c_linker_sym_t *sym, long *diffp) 702 { 703 linker_file_t lf; 704 c_linker_sym_t best, es; 705 u_long diff, bestdiff, off; 706 707 best = 0; 708 off = (uintptr_t)value; 709 bestdiff = off; 710 TAILQ_FOREACH(lf, &linker_files, link) { 711 if (LINKER_SEARCH_SYMBOL(lf, value, &es, &diff) != 0) 712 continue; 713 if (es != 0 && diff < bestdiff) { 714 best = es; 715 bestdiff = diff; 716 } 717 if (bestdiff == 0) 718 break; 719 } 720 if (best) { 721 *sym = best; 722 *diffp = bestdiff; 723 return (0); 724 } else { 725 *sym = 0; 726 *diffp = off; 727 return (ENOENT); 728 } 729 } 730 731 int 732 linker_ddb_symbol_values(c_linker_sym_t sym, linker_symval_t *symval) 733 { 734 linker_file_t lf; 735 736 TAILQ_FOREACH(lf, &linker_files, link) { 737 if (LINKER_SYMBOL_VALUES(lf, sym, symval) == 0) 738 return (0); 739 } 740 return (ENOENT); 741 } 742 #endif 743 744 /* 745 * Syscalls. 746 */ 747 /* 748 * MPSAFE 749 */ 750 int 751 kldload(struct thread *td, struct kldload_args *uap) 752 { 753 char *kldname, *modname; 754 char *pathname = NULL; 755 linker_file_t lf; 756 int error = 0; 757 758 td->td_retval[0] = -1; 759 760 mtx_lock(&Giant); 761 762 if ((error = securelevel_gt(td->td_ucred, 0)) != 0) 763 goto out; 764 765 if ((error = suser(td)) != 0) 766 goto out; 767 768 pathname = malloc(MAXPATHLEN, M_TEMP, M_WAITOK); 769 if ((error = copyinstr(uap->file, pathname, MAXPATHLEN, NULL)) != 0) 770 goto out; 771 772 /* 773 * If path do not contain qualified name or any dot in it 774 * (kldname.ko, or kldname.ver.ko) treat it as interface 775 * name. 776 */ 777 if (index(pathname, '/') || index(pathname, '.')) { 778 kldname = pathname; 779 modname = NULL; 780 } else { 781 kldname = NULL; 782 modname = pathname; 783 } 784 error = linker_load_module(kldname, modname, NULL, NULL, &lf); 785 if (error) 786 goto out; 787 788 lf->userrefs++; 789 td->td_retval[0] = lf->id; 790 out: 791 if (pathname) 792 free(pathname, M_TEMP); 793 mtx_unlock(&Giant); 794 return (error); 795 } 796 797 /* 798 * MPSAFE 799 */ 800 static int 801 kern_kldunload(struct thread *td, int fileid, int flags) 802 { 803 linker_file_t lf; 804 int error = 0; 805 806 mtx_lock(&Giant); 807 808 if ((error = securelevel_gt(td->td_ucred, 0)) != 0) 809 goto out; 810 811 if ((error = suser(td)) != 0) 812 goto out; 813 814 lf = linker_find_file_by_id(fileid); 815 if (lf) { 816 KLD_DPF(FILE, ("kldunload: lf->userrefs=%d\n", lf->userrefs)); 817 if (lf->userrefs == 0) { 818 /* 819 * XXX: maybe LINKER_UNLOAD_FORCE should override ? 820 */ 821 printf("kldunload: attempt to unload file that was" 822 " loaded by the kernel\n"); 823 error = EBUSY; 824 goto out; 825 } 826 lf->userrefs--; 827 error = linker_file_unload(lf, flags); 828 if (error) 829 lf->userrefs++; 830 } else 831 error = ENOENT; 832 out: 833 mtx_unlock(&Giant); 834 return (error); 835 } 836 837 /* 838 * MPSAFE 839 */ 840 int 841 kldunload(struct thread *td, struct kldunload_args *uap) 842 { 843 844 return (kern_kldunload(td, uap->fileid, LINKER_UNLOAD_NORMAL)); 845 } 846 847 /* 848 * MPSAFE 849 */ 850 int 851 kldunloadf(struct thread *td, struct kldunloadf_args *uap) 852 { 853 854 if (uap->flags != LINKER_UNLOAD_NORMAL && 855 uap->flags != LINKER_UNLOAD_FORCE) 856 return (EINVAL); 857 return (kern_kldunload(td, uap->fileid, uap->flags)); 858 } 859 860 /* 861 * MPSAFE 862 */ 863 int 864 kldfind(struct thread *td, struct kldfind_args *uap) 865 { 866 char *pathname; 867 const char *filename; 868 linker_file_t lf; 869 int error = 0; 870 871 #ifdef MAC 872 error = mac_check_kld_stat(td->td_ucred); 873 if (error) 874 return (error); 875 #endif 876 877 mtx_lock(&Giant); 878 td->td_retval[0] = -1; 879 880 pathname = malloc(MAXPATHLEN, M_TEMP, M_WAITOK); 881 if ((error = copyinstr(uap->file, pathname, MAXPATHLEN, NULL)) != 0) 882 goto out; 883 884 filename = linker_basename(pathname); 885 lf = linker_find_file_by_name(filename); 886 if (lf) 887 td->td_retval[0] = lf->id; 888 else 889 error = ENOENT; 890 out: 891 if (pathname) 892 free(pathname, M_TEMP); 893 mtx_unlock(&Giant); 894 return (error); 895 } 896 897 /* 898 * MPSAFE 899 */ 900 int 901 kldnext(struct thread *td, struct kldnext_args *uap) 902 { 903 linker_file_t lf; 904 int error = 0; 905 906 #ifdef MAC 907 error = mac_check_kld_stat(td->td_ucred); 908 if (error) 909 return (error); 910 #endif 911 912 mtx_lock(&Giant); 913 914 if (uap->fileid == 0) { 915 mtx_lock(&kld_mtx); 916 if (TAILQ_FIRST(&linker_files)) 917 td->td_retval[0] = TAILQ_FIRST(&linker_files)->id; 918 else 919 td->td_retval[0] = 0; 920 mtx_unlock(&kld_mtx); 921 goto out; 922 } 923 lf = linker_find_file_by_id(uap->fileid); 924 if (lf) { 925 if (TAILQ_NEXT(lf, link)) 926 td->td_retval[0] = TAILQ_NEXT(lf, link)->id; 927 else 928 td->td_retval[0] = 0; 929 } else 930 error = ENOENT; 931 out: 932 mtx_unlock(&Giant); 933 return (error); 934 } 935 936 /* 937 * MPSAFE 938 */ 939 int 940 kldstat(struct thread *td, struct kldstat_args *uap) 941 { 942 linker_file_t lf; 943 int error = 0; 944 int namelen, version; 945 struct kld_file_stat *stat; 946 947 #ifdef MAC 948 error = mac_check_kld_stat(td->td_ucred); 949 if (error) 950 return (error); 951 #endif 952 953 mtx_lock(&Giant); 954 955 lf = linker_find_file_by_id(uap->fileid); 956 if (lf == NULL) { 957 error = ENOENT; 958 goto out; 959 } 960 stat = uap->stat; 961 962 /* 963 * Check the version of the user's structure. 964 */ 965 if ((error = copyin(&stat->version, &version, sizeof(version))) != 0) 966 goto out; 967 if (version != sizeof(struct kld_file_stat)) { 968 error = EINVAL; 969 goto out; 970 } 971 namelen = strlen(lf->filename) + 1; 972 if (namelen > MAXPATHLEN) 973 namelen = MAXPATHLEN; 974 if ((error = copyout(lf->filename, &stat->name[0], namelen)) != 0) 975 goto out; 976 if ((error = copyout(&lf->refs, &stat->refs, sizeof(int))) != 0) 977 goto out; 978 if ((error = copyout(&lf->id, &stat->id, sizeof(int))) != 0) 979 goto out; 980 if ((error = copyout(&lf->address, &stat->address, 981 sizeof(caddr_t))) != 0) 982 goto out; 983 if ((error = copyout(&lf->size, &stat->size, sizeof(size_t))) != 0) 984 goto out; 985 986 td->td_retval[0] = 0; 987 out: 988 mtx_unlock(&Giant); 989 return (error); 990 } 991 992 /* 993 * MPSAFE 994 */ 995 int 996 kldfirstmod(struct thread *td, struct kldfirstmod_args *uap) 997 { 998 linker_file_t lf; 999 module_t mp; 1000 int error = 0; 1001 1002 #ifdef MAC 1003 error = mac_check_kld_stat(td->td_ucred); 1004 if (error) 1005 return (error); 1006 #endif 1007 1008 mtx_lock(&Giant); 1009 lf = linker_find_file_by_id(uap->fileid); 1010 if (lf) { 1011 MOD_SLOCK; 1012 mp = TAILQ_FIRST(&lf->modules); 1013 if (mp != NULL) 1014 td->td_retval[0] = module_getid(mp); 1015 else 1016 td->td_retval[0] = 0; 1017 MOD_SUNLOCK; 1018 } else 1019 error = ENOENT; 1020 mtx_unlock(&Giant); 1021 return (error); 1022 } 1023 1024 /* 1025 * MPSAFE 1026 */ 1027 int 1028 kldsym(struct thread *td, struct kldsym_args *uap) 1029 { 1030 char *symstr = NULL; 1031 c_linker_sym_t sym; 1032 linker_symval_t symval; 1033 linker_file_t lf; 1034 struct kld_sym_lookup lookup; 1035 int error = 0; 1036 1037 #ifdef MAC 1038 error = mac_check_kld_stat(td->td_ucred); 1039 if (error) 1040 return (error); 1041 #endif 1042 1043 mtx_lock(&Giant); 1044 1045 if ((error = copyin(uap->data, &lookup, sizeof(lookup))) != 0) 1046 goto out; 1047 if (lookup.version != sizeof(lookup) || 1048 uap->cmd != KLDSYM_LOOKUP) { 1049 error = EINVAL; 1050 goto out; 1051 } 1052 symstr = malloc(MAXPATHLEN, M_TEMP, M_WAITOK); 1053 if ((error = copyinstr(lookup.symname, symstr, MAXPATHLEN, NULL)) != 0) 1054 goto out; 1055 if (uap->fileid != 0) { 1056 lf = linker_find_file_by_id(uap->fileid); 1057 if (lf == NULL) { 1058 error = ENOENT; 1059 goto out; 1060 } 1061 if (LINKER_LOOKUP_SYMBOL(lf, symstr, &sym) == 0 && 1062 LINKER_SYMBOL_VALUES(lf, sym, &symval) == 0) { 1063 lookup.symvalue = (uintptr_t) symval.value; 1064 lookup.symsize = symval.size; 1065 error = copyout(&lookup, uap->data, sizeof(lookup)); 1066 } else 1067 error = ENOENT; 1068 } else { 1069 mtx_lock(&kld_mtx); 1070 TAILQ_FOREACH(lf, &linker_files, link) { 1071 if (LINKER_LOOKUP_SYMBOL(lf, symstr, &sym) == 0 && 1072 LINKER_SYMBOL_VALUES(lf, sym, &symval) == 0) { 1073 lookup.symvalue = (uintptr_t)symval.value; 1074 lookup.symsize = symval.size; 1075 error = copyout(&lookup, uap->data, 1076 sizeof(lookup)); 1077 break; 1078 } 1079 } 1080 mtx_unlock(&kld_mtx); 1081 if (lf == NULL) 1082 error = ENOENT; 1083 } 1084 out: 1085 if (symstr) 1086 free(symstr, M_TEMP); 1087 mtx_unlock(&Giant); 1088 return (error); 1089 } 1090 1091 /* 1092 * Preloaded module support 1093 */ 1094 1095 static modlist_t 1096 modlist_lookup(const char *name, int ver) 1097 { 1098 modlist_t mod; 1099 1100 TAILQ_FOREACH(mod, &found_modules, link) { 1101 if (strcmp(mod->name, name) == 0 && 1102 (ver == 0 || mod->version == ver)) 1103 return (mod); 1104 } 1105 return (NULL); 1106 } 1107 1108 static modlist_t 1109 modlist_lookup2(const char *name, struct mod_depend *verinfo) 1110 { 1111 modlist_t mod, bestmod; 1112 int ver; 1113 1114 if (verinfo == NULL) 1115 return (modlist_lookup(name, 0)); 1116 bestmod = NULL; 1117 for (mod = TAILQ_FIRST(&found_modules); mod; 1118 mod = TAILQ_NEXT(mod, link)) { 1119 if (strcmp(mod->name, name) != 0) 1120 continue; 1121 ver = mod->version; 1122 if (ver == verinfo->md_ver_preferred) 1123 return (mod); 1124 if (ver >= verinfo->md_ver_minimum && 1125 ver <= verinfo->md_ver_maximum && 1126 (bestmod == NULL || ver > bestmod->version)) 1127 bestmod = mod; 1128 } 1129 return (bestmod); 1130 } 1131 1132 static modlist_t 1133 modlist_newmodule(const char *modname, int version, linker_file_t container) 1134 { 1135 modlist_t mod; 1136 1137 mod = malloc(sizeof(struct modlist), M_LINKER, M_NOWAIT | M_ZERO); 1138 if (mod == NULL) 1139 panic("no memory for module list"); 1140 mod->container = container; 1141 mod->name = modname; 1142 mod->version = version; 1143 TAILQ_INSERT_TAIL(&found_modules, mod, link); 1144 return (mod); 1145 } 1146 1147 static void 1148 linker_addmodules(linker_file_t lf, struct mod_metadata **start, 1149 struct mod_metadata **stop, int preload) 1150 { 1151 struct mod_metadata *mp, **mdp; 1152 const char *modname; 1153 int ver; 1154 1155 for (mdp = start; mdp < stop; mdp++) { 1156 mp = *mdp; 1157 if (mp->md_type != MDT_VERSION) 1158 continue; 1159 modname = mp->md_cval; 1160 ver = ((struct mod_version *)mp->md_data)->mv_version; 1161 if (modlist_lookup(modname, ver) != NULL) { 1162 printf("module %s already present!\n", modname); 1163 /* XXX what can we do? this is a build error. :-( */ 1164 continue; 1165 } 1166 modlist_newmodule(modname, ver, lf); 1167 } 1168 } 1169 1170 static void 1171 linker_preload(void *arg) 1172 { 1173 caddr_t modptr; 1174 const char *modname, *nmodname; 1175 char *modtype; 1176 linker_file_t lf; 1177 linker_class_t lc; 1178 int error; 1179 linker_file_list_t loaded_files; 1180 linker_file_list_t depended_files; 1181 struct mod_metadata *mp, *nmp; 1182 struct mod_metadata **start, **stop, **mdp, **nmdp; 1183 struct mod_depend *verinfo; 1184 int nver; 1185 int resolves; 1186 modlist_t mod; 1187 struct sysinit **si_start, **si_stop; 1188 1189 TAILQ_INIT(&loaded_files); 1190 TAILQ_INIT(&depended_files); 1191 TAILQ_INIT(&found_modules); 1192 error = 0; 1193 1194 modptr = NULL; 1195 while ((modptr = preload_search_next_name(modptr)) != NULL) { 1196 modname = (char *)preload_search_info(modptr, MODINFO_NAME); 1197 modtype = (char *)preload_search_info(modptr, MODINFO_TYPE); 1198 if (modname == NULL) { 1199 printf("Preloaded module at %p does not have a" 1200 " name!\n", modptr); 1201 continue; 1202 } 1203 if (modtype == NULL) { 1204 printf("Preloaded module at %p does not have a type!\n", 1205 modptr); 1206 continue; 1207 } 1208 if (bootverbose) 1209 printf("Preloaded %s \"%s\" at %p.\n", modtype, modname, 1210 modptr); 1211 lf = NULL; 1212 TAILQ_FOREACH(lc, &classes, link) { 1213 error = LINKER_LINK_PRELOAD(lc, modname, &lf); 1214 if (!error) 1215 break; 1216 lf = NULL; 1217 } 1218 if (lf) 1219 TAILQ_INSERT_TAIL(&loaded_files, lf, loaded); 1220 } 1221 1222 /* 1223 * First get a list of stuff in the kernel. 1224 */ 1225 if (linker_file_lookup_set(linker_kernel_file, MDT_SETNAME, &start, 1226 &stop, NULL) == 0) 1227 linker_addmodules(linker_kernel_file, start, stop, 1); 1228 1229 /* 1230 * this is a once-off kinky bubble sort resolve relocation dependency 1231 * requirements 1232 */ 1233 restart: 1234 TAILQ_FOREACH(lf, &loaded_files, loaded) { 1235 error = linker_file_lookup_set(lf, MDT_SETNAME, &start, 1236 &stop, NULL); 1237 /* 1238 * First, look to see if we would successfully link with this 1239 * stuff. 1240 */ 1241 resolves = 1; /* unless we know otherwise */ 1242 if (!error) { 1243 for (mdp = start; mdp < stop; mdp++) { 1244 mp = *mdp; 1245 if (mp->md_type != MDT_DEPEND) 1246 continue; 1247 modname = mp->md_cval; 1248 verinfo = mp->md_data; 1249 for (nmdp = start; nmdp < stop; nmdp++) { 1250 nmp = *nmdp; 1251 if (nmp->md_type != MDT_VERSION) 1252 continue; 1253 nmodname = nmp->md_cval; 1254 if (strcmp(modname, nmodname) == 0) 1255 break; 1256 } 1257 if (nmdp < stop) /* it's a self reference */ 1258 continue; 1259 1260 /* 1261 * ok, the module isn't here yet, we 1262 * are not finished 1263 */ 1264 if (modlist_lookup2(modname, verinfo) == NULL) 1265 resolves = 0; 1266 } 1267 } 1268 /* 1269 * OK, if we found our modules, we can link. So, "provide" 1270 * the modules inside and add it to the end of the link order 1271 * list. 1272 */ 1273 if (resolves) { 1274 if (!error) { 1275 for (mdp = start; mdp < stop; mdp++) { 1276 mp = *mdp; 1277 if (mp->md_type != MDT_VERSION) 1278 continue; 1279 modname = mp->md_cval; 1280 nver = ((struct mod_version *) 1281 mp->md_data)->mv_version; 1282 if (modlist_lookup(modname, 1283 nver) != NULL) { 1284 printf("module %s already" 1285 " present!\n", modname); 1286 linker_file_unload(lf, 1287 LINKER_UNLOAD_FORCE); 1288 TAILQ_REMOVE(&loaded_files, 1289 lf, loaded); 1290 /* we changed tailq next ptr */ 1291 goto restart; 1292 } 1293 modlist_newmodule(modname, nver, lf); 1294 } 1295 } 1296 TAILQ_REMOVE(&loaded_files, lf, loaded); 1297 TAILQ_INSERT_TAIL(&depended_files, lf, loaded); 1298 /* 1299 * Since we provided modules, we need to restart the 1300 * sort so that the previous files that depend on us 1301 * have a chance. Also, we've busted the tailq next 1302 * pointer with the REMOVE. 1303 */ 1304 goto restart; 1305 } 1306 } 1307 1308 /* 1309 * At this point, we check to see what could not be resolved.. 1310 */ 1311 TAILQ_FOREACH(lf, &loaded_files, loaded) { 1312 printf("KLD file %s is missing dependencies\n", lf->filename); 1313 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 1314 TAILQ_REMOVE(&loaded_files, lf, loaded); 1315 } 1316 1317 /* 1318 * We made it. Finish off the linking in the order we determined. 1319 */ 1320 TAILQ_FOREACH(lf, &depended_files, loaded) { 1321 if (linker_kernel_file) { 1322 linker_kernel_file->refs++; 1323 error = linker_file_add_dependency(lf, 1324 linker_kernel_file); 1325 if (error) 1326 panic("cannot add dependency"); 1327 } 1328 lf->userrefs++; /* so we can (try to) kldunload it */ 1329 error = linker_file_lookup_set(lf, MDT_SETNAME, &start, 1330 &stop, NULL); 1331 if (!error) { 1332 for (mdp = start; mdp < stop; mdp++) { 1333 mp = *mdp; 1334 if (mp->md_type != MDT_DEPEND) 1335 continue; 1336 modname = mp->md_cval; 1337 verinfo = mp->md_data; 1338 mod = modlist_lookup2(modname, verinfo); 1339 /* Don't count self-dependencies */ 1340 if (lf == mod->container) 1341 continue; 1342 mod->container->refs++; 1343 error = linker_file_add_dependency(lf, 1344 mod->container); 1345 if (error) 1346 panic("cannot add dependency"); 1347 } 1348 } 1349 /* 1350 * Now do relocation etc using the symbol search paths 1351 * established by the dependencies 1352 */ 1353 error = LINKER_LINK_PRELOAD_FINISH(lf); 1354 if (error) { 1355 printf("KLD file %s - could not finalize loading\n", 1356 lf->filename); 1357 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 1358 continue; 1359 } 1360 linker_file_register_modules(lf); 1361 if (linker_file_lookup_set(lf, "sysinit_set", &si_start, 1362 &si_stop, NULL) == 0) 1363 sysinit_add(si_start, si_stop); 1364 linker_file_register_sysctls(lf); 1365 lf->flags |= LINKER_FILE_LINKED; 1366 } 1367 /* woohoo! we made it! */ 1368 } 1369 1370 SYSINIT(preload, SI_SUB_KLD, SI_ORDER_MIDDLE, linker_preload, 0) 1371 1372 /* 1373 * Search for a not-loaded module by name. 1374 * 1375 * Modules may be found in the following locations: 1376 * 1377 * - preloaded (result is just the module name) - on disk (result is full path 1378 * to module) 1379 * 1380 * If the module name is qualified in any way (contains path, etc.) the we 1381 * simply return a copy of it. 1382 * 1383 * The search path can be manipulated via sysctl. Note that we use the ';' 1384 * character as a separator to be consistent with the bootloader. 1385 */ 1386 1387 static char linker_hintfile[] = "linker.hints"; 1388 static char linker_path[MAXPATHLEN] = "/boot/kernel;/boot/modules"; 1389 1390 SYSCTL_STRING(_kern, OID_AUTO, module_path, CTLFLAG_RW, linker_path, 1391 sizeof(linker_path), "module load search path"); 1392 1393 TUNABLE_STR("module_path", linker_path, sizeof(linker_path)); 1394 1395 static char *linker_ext_list[] = { 1396 "", 1397 ".ko", 1398 NULL 1399 }; 1400 1401 /* 1402 * Check if file actually exists either with or without extension listed in 1403 * the linker_ext_list. (probably should be generic for the rest of the 1404 * kernel) 1405 */ 1406 static char * 1407 linker_lookup_file(const char *path, int pathlen, const char *name, 1408 int namelen, struct vattr *vap) 1409 { 1410 struct nameidata nd; 1411 struct thread *td = curthread; /* XXX */ 1412 char *result, **cpp, *sep; 1413 int error, len, extlen, reclen, flags; 1414 enum vtype type; 1415 1416 extlen = 0; 1417 for (cpp = linker_ext_list; *cpp; cpp++) { 1418 len = strlen(*cpp); 1419 if (len > extlen) 1420 extlen = len; 1421 } 1422 extlen++; /* trailing '\0' */ 1423 sep = (path[pathlen - 1] != '/') ? "/" : ""; 1424 1425 reclen = pathlen + strlen(sep) + namelen + extlen + 1; 1426 result = malloc(reclen, M_LINKER, M_WAITOK); 1427 for (cpp = linker_ext_list; *cpp; cpp++) { 1428 snprintf(result, reclen, "%.*s%s%.*s%s", pathlen, path, sep, 1429 namelen, name, *cpp); 1430 /* 1431 * Attempt to open the file, and return the path if 1432 * we succeed and it's a regular file. 1433 */ 1434 NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, result, td); 1435 flags = FREAD; 1436 error = vn_open(&nd, &flags, 0, -1); 1437 if (error == 0) { 1438 NDFREE(&nd, NDF_ONLY_PNBUF); 1439 type = nd.ni_vp->v_type; 1440 if (vap) 1441 VOP_GETATTR(nd.ni_vp, vap, td->td_ucred, td); 1442 VOP_UNLOCK(nd.ni_vp, 0, td); 1443 vn_close(nd.ni_vp, FREAD, td->td_ucred, td); 1444 if (type == VREG) 1445 return (result); 1446 } 1447 } 1448 free(result, M_LINKER); 1449 return (NULL); 1450 } 1451 1452 #define INT_ALIGN(base, ptr) ptr = \ 1453 (base) + (((ptr) - (base) + sizeof(int) - 1) & ~(sizeof(int) - 1)) 1454 1455 /* 1456 * Lookup KLD which contains requested module in the "linker.hints" file. If 1457 * version specification is available, then try to find the best KLD. 1458 * Otherwise just find the latest one. 1459 */ 1460 static char * 1461 linker_hints_lookup(const char *path, int pathlen, const char *modname, 1462 int modnamelen, struct mod_depend *verinfo) 1463 { 1464 struct thread *td = curthread; /* XXX */ 1465 struct ucred *cred = td ? td->td_ucred : NULL; 1466 struct nameidata nd; 1467 struct vattr vattr, mattr; 1468 u_char *hints = NULL; 1469 u_char *cp, *recptr, *bufend, *result, *best, *pathbuf, *sep; 1470 int error, ival, bestver, *intp, reclen, found, flags, clen, blen; 1471 1472 result = NULL; 1473 bestver = found = 0; 1474 1475 sep = (path[pathlen - 1] != '/') ? "/" : ""; 1476 reclen = imax(modnamelen, strlen(linker_hintfile)) + pathlen + 1477 strlen(sep) + 1; 1478 pathbuf = malloc(reclen, M_LINKER, M_WAITOK); 1479 snprintf(pathbuf, reclen, "%.*s%s%s", pathlen, path, sep, 1480 linker_hintfile); 1481 1482 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, pathbuf, td); 1483 flags = FREAD; 1484 error = vn_open(&nd, &flags, 0, -1); 1485 if (error) 1486 goto bad; 1487 NDFREE(&nd, NDF_ONLY_PNBUF); 1488 if (nd.ni_vp->v_type != VREG) 1489 goto bad; 1490 best = cp = NULL; 1491 error = VOP_GETATTR(nd.ni_vp, &vattr, cred, td); 1492 if (error) 1493 goto bad; 1494 /* 1495 * XXX: we need to limit this number to some reasonable value 1496 */ 1497 if (vattr.va_size > 100 * 1024) { 1498 printf("hints file too large %ld\n", (long)vattr.va_size); 1499 goto bad; 1500 } 1501 hints = malloc(vattr.va_size, M_TEMP, M_WAITOK); 1502 if (hints == NULL) 1503 goto bad; 1504 error = vn_rdwr(UIO_READ, nd.ni_vp, (caddr_t)hints, vattr.va_size, 0, 1505 UIO_SYSSPACE, IO_NODELOCKED, cred, NOCRED, &reclen, td); 1506 if (error) 1507 goto bad; 1508 VOP_UNLOCK(nd.ni_vp, 0, td); 1509 vn_close(nd.ni_vp, FREAD, cred, td); 1510 nd.ni_vp = NULL; 1511 if (reclen != 0) { 1512 printf("can't read %d\n", reclen); 1513 goto bad; 1514 } 1515 intp = (int *)hints; 1516 ival = *intp++; 1517 if (ival != LINKER_HINTS_VERSION) { 1518 printf("hints file version mismatch %d\n", ival); 1519 goto bad; 1520 } 1521 bufend = hints + vattr.va_size; 1522 recptr = (u_char *)intp; 1523 clen = blen = 0; 1524 while (recptr < bufend && !found) { 1525 intp = (int *)recptr; 1526 reclen = *intp++; 1527 ival = *intp++; 1528 cp = (char *)intp; 1529 switch (ival) { 1530 case MDT_VERSION: 1531 clen = *cp++; 1532 if (clen != modnamelen || bcmp(cp, modname, clen) != 0) 1533 break; 1534 cp += clen; 1535 INT_ALIGN(hints, cp); 1536 ival = *(int *)cp; 1537 cp += sizeof(int); 1538 clen = *cp++; 1539 if (verinfo == NULL || 1540 ival == verinfo->md_ver_preferred) { 1541 found = 1; 1542 break; 1543 } 1544 if (ival >= verinfo->md_ver_minimum && 1545 ival <= verinfo->md_ver_maximum && 1546 ival > bestver) { 1547 bestver = ival; 1548 best = cp; 1549 blen = clen; 1550 } 1551 break; 1552 default: 1553 break; 1554 } 1555 recptr += reclen + sizeof(int); 1556 } 1557 /* 1558 * Finally check if KLD is in the place 1559 */ 1560 if (found) 1561 result = linker_lookup_file(path, pathlen, cp, clen, &mattr); 1562 else if (best) 1563 result = linker_lookup_file(path, pathlen, best, blen, &mattr); 1564 1565 /* 1566 * KLD is newer than hints file. What we should do now? 1567 */ 1568 if (result && timespeccmp(&mattr.va_mtime, &vattr.va_mtime, >)) 1569 printf("warning: KLD '%s' is newer than the linker.hints" 1570 " file\n", result); 1571 bad: 1572 free(pathbuf, M_LINKER); 1573 if (hints) 1574 free(hints, M_TEMP); 1575 if (nd.ni_vp != NULL) { 1576 VOP_UNLOCK(nd.ni_vp, 0, td); 1577 vn_close(nd.ni_vp, FREAD, cred, td); 1578 } 1579 /* 1580 * If nothing found or hints is absent - fallback to the old 1581 * way by using "kldname[.ko]" as module name. 1582 */ 1583 if (!found && !bestver && result == NULL) 1584 result = linker_lookup_file(path, pathlen, modname, 1585 modnamelen, NULL); 1586 return (result); 1587 } 1588 1589 /* 1590 * Lookup KLD which contains requested module in the all directories. 1591 */ 1592 static char * 1593 linker_search_module(const char *modname, int modnamelen, 1594 struct mod_depend *verinfo) 1595 { 1596 char *cp, *ep, *result; 1597 1598 /* 1599 * traverse the linker path 1600 */ 1601 for (cp = linker_path; *cp; cp = ep + 1) { 1602 /* find the end of this component */ 1603 for (ep = cp; (*ep != 0) && (*ep != ';'); ep++); 1604 result = linker_hints_lookup(cp, ep - cp, modname, 1605 modnamelen, verinfo); 1606 if (result != NULL) 1607 return (result); 1608 if (*ep == 0) 1609 break; 1610 } 1611 return (NULL); 1612 } 1613 1614 /* 1615 * Search for module in all directories listed in the linker_path. 1616 */ 1617 static char * 1618 linker_search_kld(const char *name) 1619 { 1620 char *cp, *ep, *result, **cpp; 1621 int extlen, len; 1622 1623 /* qualified at all? */ 1624 if (index(name, '/')) 1625 return (linker_strdup(name)); 1626 1627 extlen = 0; 1628 for (cpp = linker_ext_list; *cpp; cpp++) { 1629 len = strlen(*cpp); 1630 if (len > extlen) 1631 extlen = len; 1632 } 1633 extlen++; /* trailing '\0' */ 1634 1635 /* traverse the linker path */ 1636 len = strlen(name); 1637 for (ep = linker_path; *ep; ep++) { 1638 cp = ep; 1639 /* find the end of this component */ 1640 for (; *ep != 0 && *ep != ';'; ep++); 1641 result = linker_lookup_file(cp, ep - cp, name, len, NULL); 1642 if (result != NULL) 1643 return (result); 1644 } 1645 return (NULL); 1646 } 1647 1648 static const char * 1649 linker_basename(const char *path) 1650 { 1651 const char *filename; 1652 1653 filename = rindex(path, '/'); 1654 if (filename == NULL) 1655 return path; 1656 if (filename[1]) 1657 filename++; 1658 return (filename); 1659 } 1660 1661 /* 1662 * Find a file which contains given module and load it, if "parent" is not 1663 * NULL, register a reference to it. 1664 */ 1665 int 1666 linker_load_module(const char *kldname, const char *modname, 1667 struct linker_file *parent, struct mod_depend *verinfo, 1668 struct linker_file **lfpp) 1669 { 1670 linker_file_t lfdep; 1671 const char *filename; 1672 char *pathname; 1673 int error; 1674 1675 if (modname == NULL) { 1676 /* 1677 * We have to load KLD 1678 */ 1679 KASSERT(verinfo == NULL, ("linker_load_module: verinfo" 1680 " is not NULL")); 1681 pathname = linker_search_kld(kldname); 1682 } else { 1683 if (modlist_lookup2(modname, verinfo) != NULL) 1684 return (EEXIST); 1685 if (kldname != NULL) 1686 pathname = linker_strdup(kldname); 1687 else if (rootvnode == NULL) 1688 pathname = NULL; 1689 else 1690 /* 1691 * Need to find a KLD with required module 1692 */ 1693 pathname = linker_search_module(modname, 1694 strlen(modname), verinfo); 1695 } 1696 if (pathname == NULL) 1697 return (ENOENT); 1698 1699 /* 1700 * Can't load more than one file with the same basename XXX: 1701 * Actually it should be possible to have multiple KLDs with 1702 * the same basename but different path because they can 1703 * provide different versions of the same modules. 1704 */ 1705 filename = linker_basename(pathname); 1706 if (linker_find_file_by_name(filename)) { 1707 error = EEXIST; 1708 goto out; 1709 } 1710 do { 1711 error = linker_load_file(pathname, &lfdep); 1712 if (error) 1713 break; 1714 if (modname && verinfo && 1715 modlist_lookup2(modname, verinfo) == NULL) { 1716 linker_file_unload(lfdep, LINKER_UNLOAD_FORCE); 1717 error = ENOENT; 1718 break; 1719 } 1720 if (parent) { 1721 error = linker_file_add_dependency(parent, lfdep); 1722 if (error) 1723 break; 1724 } 1725 if (lfpp) 1726 *lfpp = lfdep; 1727 } while (0); 1728 out: 1729 if (pathname) 1730 free(pathname, M_LINKER); 1731 return (error); 1732 } 1733 1734 /* 1735 * This routine is responsible for finding dependencies of userland initiated 1736 * kldload(2)'s of files. 1737 */ 1738 int 1739 linker_load_dependencies(linker_file_t lf) 1740 { 1741 linker_file_t lfdep; 1742 struct mod_metadata **start, **stop, **mdp, **nmdp; 1743 struct mod_metadata *mp, *nmp; 1744 struct mod_depend *verinfo; 1745 modlist_t mod; 1746 const char *modname, *nmodname; 1747 int ver, error = 0, count; 1748 1749 /* 1750 * All files are dependant on /kernel. 1751 */ 1752 if (linker_kernel_file) { 1753 linker_kernel_file->refs++; 1754 error = linker_file_add_dependency(lf, linker_kernel_file); 1755 if (error) 1756 return (error); 1757 } 1758 if (linker_file_lookup_set(lf, MDT_SETNAME, &start, &stop, 1759 &count) != 0) 1760 return (0); 1761 for (mdp = start; mdp < stop; mdp++) { 1762 mp = *mdp; 1763 if (mp->md_type != MDT_VERSION) 1764 continue; 1765 modname = mp->md_cval; 1766 ver = ((struct mod_version *)mp->md_data)->mv_version; 1767 mod = modlist_lookup(modname, ver); 1768 if (mod != NULL) { 1769 printf("interface %s.%d already present in the KLD" 1770 " '%s'!\n", modname, ver, 1771 mod->container->filename); 1772 return (EEXIST); 1773 } 1774 } 1775 1776 for (mdp = start; mdp < stop; mdp++) { 1777 mp = *mdp; 1778 if (mp->md_type != MDT_DEPEND) 1779 continue; 1780 modname = mp->md_cval; 1781 verinfo = mp->md_data; 1782 nmodname = NULL; 1783 for (nmdp = start; nmdp < stop; nmdp++) { 1784 nmp = *nmdp; 1785 if (nmp->md_type != MDT_VERSION) 1786 continue; 1787 nmodname = nmp->md_cval; 1788 if (strcmp(modname, nmodname) == 0) 1789 break; 1790 } 1791 if (nmdp < stop)/* early exit, it's a self reference */ 1792 continue; 1793 mod = modlist_lookup2(modname, verinfo); 1794 if (mod) { /* woohoo, it's loaded already */ 1795 lfdep = mod->container; 1796 lfdep->refs++; 1797 error = linker_file_add_dependency(lf, lfdep); 1798 if (error) 1799 break; 1800 continue; 1801 } 1802 error = linker_load_module(NULL, modname, lf, verinfo, NULL); 1803 if (error) { 1804 printf("KLD %s: depends on %s - not available\n", 1805 lf->filename, modname); 1806 break; 1807 } 1808 } 1809 1810 if (error) 1811 return (error); 1812 linker_addmodules(lf, start, stop, 0); 1813 return (error); 1814 } 1815 1816 static int 1817 sysctl_kern_function_list_iterate(const char *name, void *opaque) 1818 { 1819 struct sysctl_req *req; 1820 1821 req = opaque; 1822 return (SYSCTL_OUT(req, name, strlen(name) + 1)); 1823 } 1824 1825 /* 1826 * Export a nul-separated, double-nul-terminated list of all function names 1827 * in the kernel. 1828 */ 1829 static int 1830 sysctl_kern_function_list(SYSCTL_HANDLER_ARGS) 1831 { 1832 linker_file_t lf; 1833 int error; 1834 1835 #ifdef MAC 1836 error = mac_check_kld_stat(req->td->td_ucred); 1837 if (error) 1838 return (error); 1839 #endif 1840 error = sysctl_wire_old_buffer(req, 0); 1841 if (error != 0) 1842 return (error); 1843 mtx_lock(&kld_mtx); 1844 TAILQ_FOREACH(lf, &linker_files, link) { 1845 error = LINKER_EACH_FUNCTION_NAME(lf, 1846 sysctl_kern_function_list_iterate, req); 1847 if (error) { 1848 mtx_unlock(&kld_mtx); 1849 return (error); 1850 } 1851 } 1852 mtx_unlock(&kld_mtx); 1853 return (SYSCTL_OUT(req, "", 1)); 1854 } 1855 1856 SYSCTL_PROC(_kern, OID_AUTO, function_list, CTLFLAG_RD, 1857 NULL, 0, sysctl_kern_function_list, "", "kernel function list");
Cache object: 2057a8fdf750a92e5e31b91143a99c81
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