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: releng/6.3/sys/kern/kern_linker.c 173886 2007-11-24 19:45:58Z cvs2svn $"); 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 past SI_ORDER_ANY 145 * of SI_SUB_KLD. We bump the reference count to keep the 146 * ops from being freed. 147 */ 148 if (linker_no_more_classes == 1) 149 return (EPERM); 150 kobj_class_compile((kobj_class_t) lc); 151 ((kobj_class_t)lc)->refs++; /* XXX: kobj_mtx */ 152 TAILQ_INSERT_TAIL(&classes, lc, link); 153 return (0); 154 } 155 156 static void 157 linker_file_sysinit(linker_file_t lf) 158 { 159 struct sysinit **start, **stop, **sipp, **xipp, *save; 160 161 KLD_DPF(FILE, ("linker_file_sysinit: calling SYSINITs for %s\n", 162 lf->filename)); 163 164 if (linker_file_lookup_set(lf, "sysinit_set", &start, &stop, NULL) != 0) 165 return; 166 /* 167 * Perform a bubble sort of the system initialization objects by 168 * their subsystem (primary key) and order (secondary key). 169 * 170 * Since some things care about execution order, this is the operation 171 * which ensures continued function. 172 */ 173 for (sipp = start; sipp < stop; sipp++) { 174 for (xipp = sipp + 1; xipp < stop; xipp++) { 175 if ((*sipp)->subsystem < (*xipp)->subsystem || 176 ((*sipp)->subsystem == (*xipp)->subsystem && 177 (*sipp)->order <= (*xipp)->order)) 178 continue; /* skip */ 179 save = *sipp; 180 *sipp = *xipp; 181 *xipp = save; 182 } 183 } 184 185 /* 186 * Traverse the (now) ordered list of system initialization tasks. 187 * Perform each task, and continue on to the next task. 188 */ 189 for (sipp = start; sipp < stop; sipp++) { 190 if ((*sipp)->subsystem == SI_SUB_DUMMY) 191 continue; /* skip dummy task(s) */ 192 193 /* Call function */ 194 (*((*sipp)->func)) ((*sipp)->udata); 195 } 196 } 197 198 static void 199 linker_file_sysuninit(linker_file_t lf) 200 { 201 struct sysinit **start, **stop, **sipp, **xipp, *save; 202 203 KLD_DPF(FILE, ("linker_file_sysuninit: calling SYSUNINITs for %s\n", 204 lf->filename)); 205 206 if (linker_file_lookup_set(lf, "sysuninit_set", &start, &stop, 207 NULL) != 0) 208 return; 209 210 /* 211 * Perform a reverse bubble sort of the system initialization objects 212 * by their subsystem (primary key) and order (secondary key). 213 * 214 * Since some things care about execution order, this is the operation 215 * which ensures continued function. 216 */ 217 for (sipp = start; sipp < stop; sipp++) { 218 for (xipp = sipp + 1; xipp < stop; xipp++) { 219 if ((*sipp)->subsystem > (*xipp)->subsystem || 220 ((*sipp)->subsystem == (*xipp)->subsystem && 221 (*sipp)->order >= (*xipp)->order)) 222 continue; /* skip */ 223 save = *sipp; 224 *sipp = *xipp; 225 *xipp = save; 226 } 227 } 228 229 /* 230 * Traverse the (now) ordered list of system initialization tasks. 231 * Perform each task, and continue on to the next task. 232 */ 233 for (sipp = start; sipp < stop; sipp++) { 234 if ((*sipp)->subsystem == SI_SUB_DUMMY) 235 continue; /* skip dummy task(s) */ 236 237 /* Call function */ 238 (*((*sipp)->func)) ((*sipp)->udata); 239 } 240 } 241 242 static void 243 linker_file_register_sysctls(linker_file_t lf) 244 { 245 struct sysctl_oid **start, **stop, **oidp; 246 247 KLD_DPF(FILE, 248 ("linker_file_register_sysctls: registering SYSCTLs for %s\n", 249 lf->filename)); 250 251 if (linker_file_lookup_set(lf, "sysctl_set", &start, &stop, NULL) != 0) 252 return; 253 254 for (oidp = start; oidp < stop; oidp++) 255 sysctl_register_oid(*oidp); 256 } 257 258 static void 259 linker_file_unregister_sysctls(linker_file_t lf) 260 { 261 struct sysctl_oid **start, **stop, **oidp; 262 263 KLD_DPF(FILE, ("linker_file_unregister_sysctls: registering SYSCTLs" 264 " for %s\n", lf->filename)); 265 266 if (linker_file_lookup_set(lf, "sysctl_set", &start, &stop, NULL) != 0) 267 return; 268 269 for (oidp = start; oidp < stop; oidp++) 270 sysctl_unregister_oid(*oidp); 271 } 272 273 static int 274 linker_file_register_modules(linker_file_t lf) 275 { 276 struct mod_metadata **start, **stop, **mdp; 277 const moduledata_t *moddata; 278 int first_error, error; 279 280 KLD_DPF(FILE, ("linker_file_register_modules: registering modules" 281 " in %s\n", lf->filename)); 282 283 if (linker_file_lookup_set(lf, "modmetadata_set", &start, 284 &stop, 0) != 0) { 285 /* 286 * This fallback should be unnecessary, but if we get booted 287 * from boot2 instead of loader and we are missing our 288 * metadata then we have to try the best we can. 289 */ 290 if (lf == linker_kernel_file) { 291 start = SET_BEGIN(modmetadata_set); 292 stop = SET_LIMIT(modmetadata_set); 293 } else 294 return (0); 295 } 296 first_error = 0; 297 for (mdp = start; mdp < stop; mdp++) { 298 if ((*mdp)->md_type != MDT_MODULE) 299 continue; 300 moddata = (*mdp)->md_data; 301 KLD_DPF(FILE, ("Registering module %s in %s\n", 302 moddata->name, lf->filename)); 303 error = module_register(moddata, lf); 304 if (error) { 305 printf("Module %s failed to register: %d\n", 306 moddata->name, error); 307 if (first_error == 0) 308 first_error = error; 309 } 310 } 311 return (first_error); 312 } 313 314 static void 315 linker_init_kernel_modules(void) 316 { 317 318 linker_file_register_modules(linker_kernel_file); 319 } 320 321 SYSINIT(linker_kernel, SI_SUB_KLD, SI_ORDER_ANY, linker_init_kernel_modules, 0) 322 323 static int 324 linker_load_file(const char *filename, linker_file_t *result) 325 { 326 linker_class_t lc; 327 linker_file_t lf; 328 int foundfile, error = 0; 329 330 /* Refuse to load modules if securelevel raised */ 331 if (securelevel > 0) 332 return (EPERM); 333 334 lf = linker_find_file_by_name(filename); 335 if (lf) { 336 KLD_DPF(FILE, ("linker_load_file: file %s is already loaded," 337 " incrementing refs\n", filename)); 338 *result = lf; 339 lf->refs++; 340 goto out; 341 } 342 lf = NULL; 343 foundfile = 0; 344 345 /* 346 * We do not need to protect (lock) classes here because there is 347 * no class registration past startup (SI_SUB_KLD, SI_ORDER_ANY) 348 * and there is no class deregistration mechanism at this time. 349 */ 350 TAILQ_FOREACH(lc, &classes, link) { 351 KLD_DPF(FILE, ("linker_load_file: trying to load %s\n", 352 filename)); 353 error = LINKER_LOAD_FILE(lc, filename, &lf); 354 /* 355 * If we got something other than ENOENT, then it exists but 356 * we cannot load it for some other reason. 357 */ 358 if (error != ENOENT) 359 foundfile = 1; 360 if (lf) { 361 error = linker_file_register_modules(lf); 362 if (error == EEXIST) { 363 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 364 goto out; 365 } 366 linker_file_register_sysctls(lf); 367 linker_file_sysinit(lf); 368 lf->flags |= LINKER_FILE_LINKED; 369 *result = lf; 370 error = 0; 371 goto out; 372 } 373 } 374 /* 375 * Less than ideal, but tells the user whether it failed to load or 376 * the module was not found. 377 */ 378 if (foundfile) { 379 /* 380 * Format not recognized or otherwise unloadable. 381 * When loading a module that is statically built into 382 * the kernel EEXIST percolates back up as the return 383 * value. Preserve this so that apps like sysinstall 384 * can recognize this special case and not post bogus 385 * dialog boxes. 386 */ 387 if (error != EEXIST) 388 error = ENOEXEC; 389 } else 390 error = ENOENT; /* Nothing found */ 391 out: 392 return (error); 393 } 394 395 int 396 linker_reference_module(const char *modname, struct mod_depend *verinfo, 397 linker_file_t *result) 398 { 399 modlist_t mod; 400 int error; 401 402 mtx_lock(&Giant); 403 if ((mod = modlist_lookup2(modname, verinfo)) != NULL) { 404 *result = mod->container; 405 (*result)->refs++; 406 mtx_unlock(&Giant); 407 return (0); 408 } 409 410 error = linker_load_module(NULL, modname, NULL, verinfo, result); 411 mtx_unlock(&Giant); 412 return (error); 413 } 414 415 int 416 linker_release_module(const char *modname, struct mod_depend *verinfo, 417 linker_file_t lf) 418 { 419 modlist_t mod; 420 int error; 421 422 mtx_lock(&Giant); 423 if (lf == NULL) { 424 KASSERT(modname != NULL, 425 ("linker_release_module: no file or name")); 426 mod = modlist_lookup2(modname, verinfo); 427 if (mod == NULL) { 428 mtx_unlock(&Giant); 429 return (ESRCH); 430 } 431 lf = mod->container; 432 } else 433 KASSERT(modname == NULL && verinfo == NULL, 434 ("linker_release_module: both file and name")); 435 error = linker_file_unload(lf, LINKER_UNLOAD_NORMAL); 436 mtx_unlock(&Giant); 437 return (error); 438 } 439 440 linker_file_t 441 linker_find_file_by_name(const char *filename) 442 { 443 linker_file_t lf = 0; 444 char *koname; 445 446 koname = malloc(strlen(filename) + 4, M_LINKER, M_WAITOK); 447 if (koname == NULL) 448 goto out; 449 sprintf(koname, "%s.ko", filename); 450 451 mtx_lock(&kld_mtx); 452 TAILQ_FOREACH(lf, &linker_files, link) { 453 if (strcmp(lf->filename, koname) == 0) 454 break; 455 if (strcmp(lf->filename, filename) == 0) 456 break; 457 } 458 mtx_unlock(&kld_mtx); 459 out: 460 if (koname) 461 free(koname, M_LINKER); 462 return (lf); 463 } 464 465 linker_file_t 466 linker_find_file_by_id(int fileid) 467 { 468 linker_file_t lf = 0; 469 470 mtx_lock(&kld_mtx); 471 TAILQ_FOREACH(lf, &linker_files, link) 472 if (lf->id == fileid) 473 break; 474 mtx_unlock(&kld_mtx); 475 return (lf); 476 } 477 478 linker_file_t 479 linker_make_file(const char *pathname, linker_class_t lc) 480 { 481 linker_file_t lf; 482 const char *filename; 483 484 lf = NULL; 485 filename = linker_basename(pathname); 486 487 KLD_DPF(FILE, ("linker_make_file: new file, filename=%s\n", filename)); 488 lf = (linker_file_t)kobj_create((kobj_class_t)lc, M_LINKER, M_WAITOK); 489 if (lf == NULL) 490 goto out; 491 lf->refs = 1; 492 lf->userrefs = 0; 493 lf->flags = 0; 494 lf->filename = linker_strdup(filename); 495 lf->pathname = linker_strdup(pathname); 496 LINKER_GET_NEXT_FILE_ID(lf->id); 497 lf->ndeps = 0; 498 lf->deps = NULL; 499 STAILQ_INIT(&lf->common); 500 TAILQ_INIT(&lf->modules); 501 mtx_lock(&kld_mtx); 502 TAILQ_INSERT_TAIL(&linker_files, lf, link); 503 mtx_unlock(&kld_mtx); 504 out: 505 return (lf); 506 } 507 508 int 509 linker_file_unload(linker_file_t file, int flags) 510 { 511 module_t mod, next; 512 modlist_t ml, nextml; 513 struct common_symbol *cp; 514 int error, i; 515 516 error = 0; 517 518 /* Refuse to unload modules if securelevel raised. */ 519 if (securelevel > 0) 520 return (EPERM); 521 #ifdef MAC 522 error = mac_check_kld_unload(curthread->td_ucred); 523 if (error) 524 return (error); 525 #endif 526 527 KLD_DPF(FILE, ("linker_file_unload: lf->refs=%d\n", file->refs)); 528 if (file->refs == 1) { 529 KLD_DPF(FILE, ("linker_file_unload: file is unloading," 530 " informing modules\n")); 531 532 /* 533 * Inform any modules associated with this file. 534 */ 535 MOD_XLOCK; 536 for (mod = TAILQ_FIRST(&file->modules); mod; mod = next) { 537 next = module_getfnext(mod); 538 MOD_XUNLOCK; 539 540 /* 541 * Give the module a chance to veto the unload. 542 */ 543 if ((error = module_unload(mod, flags)) != 0) { 544 KLD_DPF(FILE, ("linker_file_unload: module %p" 545 " vetoes unload\n", mod)); 546 goto out; 547 } else 548 MOD_XLOCK; 549 module_release(mod); 550 } 551 MOD_XUNLOCK; 552 } 553 file->refs--; 554 if (file->refs > 0) { 555 goto out; 556 } 557 for (ml = TAILQ_FIRST(&found_modules); ml; ml = nextml) { 558 nextml = TAILQ_NEXT(ml, link); 559 if (ml->container == file) { 560 TAILQ_REMOVE(&found_modules, ml, link); 561 free(ml, M_LINKER); 562 } 563 } 564 565 /* 566 * Don't try to run SYSUNINITs if we are unloaded due to a 567 * link error. 568 */ 569 if (file->flags & LINKER_FILE_LINKED) { 570 linker_file_sysuninit(file); 571 linker_file_unregister_sysctls(file); 572 } 573 mtx_lock(&kld_mtx); 574 TAILQ_REMOVE(&linker_files, file, link); 575 mtx_unlock(&kld_mtx); 576 577 if (file->deps) { 578 for (i = 0; i < file->ndeps; i++) 579 linker_file_unload(file->deps[i], flags); 580 free(file->deps, M_LINKER); 581 file->deps = NULL; 582 } 583 for (cp = STAILQ_FIRST(&file->common); cp; 584 cp = STAILQ_FIRST(&file->common)) { 585 STAILQ_REMOVE(&file->common, cp, common_symbol, link); 586 free(cp, M_LINKER); 587 } 588 589 LINKER_UNLOAD(file); 590 if (file->filename) { 591 free(file->filename, M_LINKER); 592 file->filename = NULL; 593 } 594 if (file->pathname) { 595 free(file->pathname, M_LINKER); 596 file->pathname = NULL; 597 } 598 kobj_delete((kobj_t) file, M_LINKER); 599 out: 600 return (error); 601 } 602 603 int 604 linker_file_add_dependency(linker_file_t file, linker_file_t dep) 605 { 606 linker_file_t *newdeps; 607 608 newdeps = malloc((file->ndeps + 1) * sizeof(linker_file_t *), 609 M_LINKER, M_WAITOK | M_ZERO); 610 if (newdeps == NULL) 611 return (ENOMEM); 612 613 if (file->deps) { 614 bcopy(file->deps, newdeps, 615 file->ndeps * sizeof(linker_file_t *)); 616 free(file->deps, M_LINKER); 617 } 618 file->deps = newdeps; 619 file->deps[file->ndeps] = dep; 620 file->ndeps++; 621 return (0); 622 } 623 624 /* 625 * Locate a linker set and its contents. This is a helper function to avoid 626 * linker_if.h exposure elsewhere. Note: firstp and lastp are really void *** 627 */ 628 int 629 linker_file_lookup_set(linker_file_t file, const char *name, 630 void *firstp, void *lastp, int *countp) 631 { 632 633 return (LINKER_LOOKUP_SET(file, name, firstp, lastp, countp)); 634 } 635 636 caddr_t 637 linker_file_lookup_symbol(linker_file_t file, const char *name, int deps) 638 { 639 c_linker_sym_t sym; 640 linker_symval_t symval; 641 caddr_t address; 642 size_t common_size = 0; 643 int i; 644 645 KLD_DPF(SYM, ("linker_file_lookup_symbol: file=%p, name=%s, deps=%d\n", 646 file, name, deps)); 647 648 if (LINKER_LOOKUP_SYMBOL(file, name, &sym) == 0) { 649 LINKER_SYMBOL_VALUES(file, sym, &symval); 650 if (symval.value == 0) 651 /* 652 * For commons, first look them up in the 653 * dependencies and only allocate space if not found 654 * there. 655 */ 656 common_size = symval.size; 657 else { 658 KLD_DPF(SYM, ("linker_file_lookup_symbol: symbol" 659 ".value=%p\n", symval.value)); 660 return (symval.value); 661 } 662 } 663 if (deps) { 664 for (i = 0; i < file->ndeps; i++) { 665 address = linker_file_lookup_symbol(file->deps[i], 666 name, 0); 667 if (address) { 668 KLD_DPF(SYM, ("linker_file_lookup_symbol:" 669 " deps value=%p\n", address)); 670 return (address); 671 } 672 } 673 } 674 if (common_size > 0) { 675 /* 676 * This is a common symbol which was not found in the 677 * dependencies. We maintain a simple common symbol table in 678 * the file object. 679 */ 680 struct common_symbol *cp; 681 682 STAILQ_FOREACH(cp, &file->common, link) { 683 if (strcmp(cp->name, name) == 0) { 684 KLD_DPF(SYM, ("linker_file_lookup_symbol:" 685 " old common value=%p\n", cp->address)); 686 return (cp->address); 687 } 688 } 689 /* 690 * Round the symbol size up to align. 691 */ 692 common_size = (common_size + sizeof(int) - 1) & -sizeof(int); 693 cp = malloc(sizeof(struct common_symbol) 694 + common_size + strlen(name) + 1, M_LINKER, 695 M_WAITOK | M_ZERO); 696 if (cp == NULL) { 697 KLD_DPF(SYM, ("linker_file_lookup_symbol: nomem\n")); 698 return (0); 699 } 700 cp->address = (caddr_t)(cp + 1); 701 cp->name = cp->address + common_size; 702 strcpy(cp->name, name); 703 bzero(cp->address, common_size); 704 STAILQ_INSERT_TAIL(&file->common, cp, link); 705 706 KLD_DPF(SYM, ("linker_file_lookup_symbol: new common" 707 " value=%p\n", cp->address)); 708 return (cp->address); 709 } 710 KLD_DPF(SYM, ("linker_file_lookup_symbol: fail\n")); 711 return (0); 712 } 713 714 #ifdef DDB 715 /* 716 * DDB Helpers. DDB has to look across multiple files with their own symbol 717 * tables and string tables. 718 * 719 * Note that we do not obey list locking protocols here. We really don't need 720 * DDB to hang because somebody's got the lock held. We'll take the chance 721 * that the files list is inconsistant instead. 722 */ 723 724 int 725 linker_ddb_lookup(const char *symstr, c_linker_sym_t *sym) 726 { 727 linker_file_t lf; 728 729 TAILQ_FOREACH(lf, &linker_files, link) { 730 if (LINKER_LOOKUP_SYMBOL(lf, symstr, sym) == 0) 731 return (0); 732 } 733 return (ENOENT); 734 } 735 736 int 737 linker_ddb_search_symbol(caddr_t value, c_linker_sym_t *sym, long *diffp) 738 { 739 linker_file_t lf; 740 c_linker_sym_t best, es; 741 u_long diff, bestdiff, off; 742 743 best = 0; 744 off = (uintptr_t)value; 745 bestdiff = off; 746 TAILQ_FOREACH(lf, &linker_files, link) { 747 if (LINKER_SEARCH_SYMBOL(lf, value, &es, &diff) != 0) 748 continue; 749 if (es != 0 && diff < bestdiff) { 750 best = es; 751 bestdiff = diff; 752 } 753 if (bestdiff == 0) 754 break; 755 } 756 if (best) { 757 *sym = best; 758 *diffp = bestdiff; 759 return (0); 760 } else { 761 *sym = 0; 762 *diffp = off; 763 return (ENOENT); 764 } 765 } 766 767 int 768 linker_ddb_symbol_values(c_linker_sym_t sym, linker_symval_t *symval) 769 { 770 linker_file_t lf; 771 772 TAILQ_FOREACH(lf, &linker_files, link) { 773 if (LINKER_SYMBOL_VALUES(lf, sym, symval) == 0) 774 return (0); 775 } 776 return (ENOENT); 777 } 778 #endif 779 780 /* 781 * Syscalls. 782 */ 783 /* 784 * MPSAFE 785 */ 786 int 787 kldload(struct thread *td, struct kldload_args *uap) 788 { 789 char *kldname, *modname; 790 char *pathname = NULL; 791 linker_file_t lf; 792 int error = 0; 793 794 td->td_retval[0] = -1; 795 796 mtx_lock(&Giant); 797 798 if ((error = securelevel_gt(td->td_ucred, 0)) != 0) 799 goto out; 800 801 if ((error = suser(td)) != 0) 802 goto out; 803 804 pathname = malloc(MAXPATHLEN, M_TEMP, M_WAITOK); 805 if ((error = copyinstr(uap->file, pathname, MAXPATHLEN, NULL)) != 0) 806 goto out; 807 808 /* 809 * If path do not contain qualified name or any dot in it 810 * (kldname.ko, or kldname.ver.ko) treat it as interface 811 * name. 812 */ 813 if (index(pathname, '/') || index(pathname, '.')) { 814 kldname = pathname; 815 modname = NULL; 816 } else { 817 kldname = NULL; 818 modname = pathname; 819 } 820 error = linker_load_module(kldname, modname, NULL, NULL, &lf); 821 if (error) 822 goto out; 823 824 lf->userrefs++; 825 td->td_retval[0] = lf->id; 826 out: 827 if (pathname) 828 free(pathname, M_TEMP); 829 mtx_unlock(&Giant); 830 return (error); 831 } 832 833 /* 834 * MPSAFE 835 */ 836 static int 837 kern_kldunload(struct thread *td, int fileid, int flags) 838 { 839 linker_file_t lf; 840 int error = 0; 841 842 mtx_lock(&Giant); 843 844 if ((error = securelevel_gt(td->td_ucred, 0)) != 0) 845 goto out; 846 847 if ((error = suser(td)) != 0) 848 goto out; 849 850 lf = linker_find_file_by_id(fileid); 851 if (lf) { 852 KLD_DPF(FILE, ("kldunload: lf->userrefs=%d\n", lf->userrefs)); 853 if (lf->userrefs == 0) { 854 /* 855 * XXX: maybe LINKER_UNLOAD_FORCE should override ? 856 */ 857 printf("kldunload: attempt to unload file that was" 858 " loaded by the kernel\n"); 859 error = EBUSY; 860 goto out; 861 } 862 lf->userrefs--; 863 error = linker_file_unload(lf, flags); 864 if (error) 865 lf->userrefs++; 866 } else 867 error = ENOENT; 868 out: 869 mtx_unlock(&Giant); 870 return (error); 871 } 872 873 /* 874 * MPSAFE 875 */ 876 int 877 kldunload(struct thread *td, struct kldunload_args *uap) 878 { 879 880 return (kern_kldunload(td, uap->fileid, LINKER_UNLOAD_NORMAL)); 881 } 882 883 /* 884 * MPSAFE 885 */ 886 int 887 kldunloadf(struct thread *td, struct kldunloadf_args *uap) 888 { 889 890 if (uap->flags != LINKER_UNLOAD_NORMAL && 891 uap->flags != LINKER_UNLOAD_FORCE) 892 return (EINVAL); 893 return (kern_kldunload(td, uap->fileid, uap->flags)); 894 } 895 896 /* 897 * MPSAFE 898 */ 899 int 900 kldfind(struct thread *td, struct kldfind_args *uap) 901 { 902 char *pathname; 903 const char *filename; 904 linker_file_t lf; 905 int error = 0; 906 907 #ifdef MAC 908 error = mac_check_kld_stat(td->td_ucred); 909 if (error) 910 return (error); 911 #endif 912 913 mtx_lock(&Giant); 914 td->td_retval[0] = -1; 915 916 pathname = malloc(MAXPATHLEN, M_TEMP, M_WAITOK); 917 if ((error = copyinstr(uap->file, pathname, MAXPATHLEN, NULL)) != 0) 918 goto out; 919 920 filename = linker_basename(pathname); 921 lf = linker_find_file_by_name(filename); 922 if (lf) 923 td->td_retval[0] = lf->id; 924 else 925 error = ENOENT; 926 out: 927 if (pathname) 928 free(pathname, M_TEMP); 929 mtx_unlock(&Giant); 930 return (error); 931 } 932 933 /* 934 * MPSAFE 935 */ 936 int 937 kldnext(struct thread *td, struct kldnext_args *uap) 938 { 939 linker_file_t lf; 940 int error = 0; 941 942 #ifdef MAC 943 error = mac_check_kld_stat(td->td_ucred); 944 if (error) 945 return (error); 946 #endif 947 948 mtx_lock(&Giant); 949 950 if (uap->fileid == 0) { 951 mtx_lock(&kld_mtx); 952 if (TAILQ_FIRST(&linker_files)) 953 td->td_retval[0] = TAILQ_FIRST(&linker_files)->id; 954 else 955 td->td_retval[0] = 0; 956 mtx_unlock(&kld_mtx); 957 goto out; 958 } 959 lf = linker_find_file_by_id(uap->fileid); 960 if (lf) { 961 if (TAILQ_NEXT(lf, link)) 962 td->td_retval[0] = TAILQ_NEXT(lf, link)->id; 963 else 964 td->td_retval[0] = 0; 965 } else 966 error = ENOENT; 967 out: 968 mtx_unlock(&Giant); 969 return (error); 970 } 971 972 /* 973 * MPSAFE 974 */ 975 int 976 kldstat(struct thread *td, struct kldstat_args *uap) 977 { 978 linker_file_t lf; 979 int error = 0; 980 int namelen, version, version_num; 981 struct kld_file_stat *stat; 982 983 #ifdef MAC 984 error = mac_check_kld_stat(td->td_ucred); 985 if (error) 986 return (error); 987 #endif 988 989 mtx_lock(&Giant); 990 991 lf = linker_find_file_by_id(uap->fileid); 992 if (lf == NULL) { 993 error = ENOENT; 994 goto out; 995 } 996 stat = uap->stat; 997 998 /* 999 * Check the version of the user's structure. 1000 */ 1001 if ((error = copyin(&stat->version, &version, sizeof(version))) != 0) 1002 goto out; 1003 if (version == sizeof(struct kld_file_stat_1)) 1004 version_num = 1; 1005 else if (version == sizeof(struct kld_file_stat)) 1006 version_num = 2; 1007 else { 1008 error = EINVAL; 1009 goto out; 1010 } 1011 1012 /* Version 1 fields: */ 1013 namelen = strlen(lf->filename) + 1; 1014 if (namelen > MAXPATHLEN) 1015 namelen = MAXPATHLEN; 1016 if ((error = copyout(lf->filename, &stat->name[0], namelen)) != 0) 1017 goto out; 1018 if ((error = copyout(&lf->refs, &stat->refs, sizeof(int))) != 0) 1019 goto out; 1020 if ((error = copyout(&lf->id, &stat->id, sizeof(int))) != 0) 1021 goto out; 1022 if ((error = copyout(&lf->address, &stat->address, 1023 sizeof(caddr_t))) != 0) 1024 goto out; 1025 if ((error = copyout(&lf->size, &stat->size, sizeof(size_t))) != 0) 1026 goto out; 1027 if (version_num > 1) { 1028 /* Version 2 fields: */ 1029 namelen = strlen(lf->pathname) + 1; 1030 if (namelen > MAXPATHLEN) 1031 namelen = MAXPATHLEN; 1032 if ((error = copyout(lf->pathname, &stat->pathname[0], 1033 namelen)) != 0) 1034 goto out; 1035 } 1036 1037 td->td_retval[0] = 0; 1038 out: 1039 mtx_unlock(&Giant); 1040 return (error); 1041 } 1042 1043 /* 1044 * MPSAFE 1045 */ 1046 int 1047 kldfirstmod(struct thread *td, struct kldfirstmod_args *uap) 1048 { 1049 linker_file_t lf; 1050 module_t mp; 1051 int error = 0; 1052 1053 #ifdef MAC 1054 error = mac_check_kld_stat(td->td_ucred); 1055 if (error) 1056 return (error); 1057 #endif 1058 1059 mtx_lock(&Giant); 1060 lf = linker_find_file_by_id(uap->fileid); 1061 if (lf) { 1062 MOD_SLOCK; 1063 mp = TAILQ_FIRST(&lf->modules); 1064 if (mp != NULL) 1065 td->td_retval[0] = module_getid(mp); 1066 else 1067 td->td_retval[0] = 0; 1068 MOD_SUNLOCK; 1069 } else 1070 error = ENOENT; 1071 mtx_unlock(&Giant); 1072 return (error); 1073 } 1074 1075 /* 1076 * MPSAFE 1077 */ 1078 int 1079 kldsym(struct thread *td, struct kldsym_args *uap) 1080 { 1081 char *symstr = NULL; 1082 c_linker_sym_t sym; 1083 linker_symval_t symval; 1084 linker_file_t lf; 1085 struct kld_sym_lookup lookup; 1086 int error = 0; 1087 1088 #ifdef MAC 1089 error = mac_check_kld_stat(td->td_ucred); 1090 if (error) 1091 return (error); 1092 #endif 1093 1094 mtx_lock(&Giant); 1095 1096 if ((error = copyin(uap->data, &lookup, sizeof(lookup))) != 0) 1097 goto out; 1098 if (lookup.version != sizeof(lookup) || 1099 uap->cmd != KLDSYM_LOOKUP) { 1100 error = EINVAL; 1101 goto out; 1102 } 1103 symstr = malloc(MAXPATHLEN, M_TEMP, M_WAITOK); 1104 if ((error = copyinstr(lookup.symname, symstr, MAXPATHLEN, NULL)) != 0) 1105 goto out; 1106 if (uap->fileid != 0) { 1107 lf = linker_find_file_by_id(uap->fileid); 1108 if (lf == NULL) { 1109 error = ENOENT; 1110 goto out; 1111 } 1112 if (LINKER_LOOKUP_SYMBOL(lf, symstr, &sym) == 0 && 1113 LINKER_SYMBOL_VALUES(lf, sym, &symval) == 0) { 1114 lookup.symvalue = (uintptr_t) symval.value; 1115 lookup.symsize = symval.size; 1116 error = copyout(&lookup, uap->data, sizeof(lookup)); 1117 } else 1118 error = ENOENT; 1119 } else { 1120 mtx_lock(&kld_mtx); 1121 TAILQ_FOREACH(lf, &linker_files, link) { 1122 if (LINKER_LOOKUP_SYMBOL(lf, symstr, &sym) == 0 && 1123 LINKER_SYMBOL_VALUES(lf, sym, &symval) == 0) { 1124 lookup.symvalue = (uintptr_t)symval.value; 1125 lookup.symsize = symval.size; 1126 error = copyout(&lookup, uap->data, 1127 sizeof(lookup)); 1128 break; 1129 } 1130 } 1131 mtx_unlock(&kld_mtx); 1132 if (lf == NULL) 1133 error = ENOENT; 1134 } 1135 out: 1136 if (symstr) 1137 free(symstr, M_TEMP); 1138 mtx_unlock(&Giant); 1139 return (error); 1140 } 1141 1142 /* 1143 * Preloaded module support 1144 */ 1145 1146 static modlist_t 1147 modlist_lookup(const char *name, int ver) 1148 { 1149 modlist_t mod; 1150 1151 TAILQ_FOREACH(mod, &found_modules, link) { 1152 if (strcmp(mod->name, name) == 0 && 1153 (ver == 0 || mod->version == ver)) 1154 return (mod); 1155 } 1156 return (NULL); 1157 } 1158 1159 static modlist_t 1160 modlist_lookup2(const char *name, struct mod_depend *verinfo) 1161 { 1162 modlist_t mod, bestmod; 1163 int ver; 1164 1165 if (verinfo == NULL) 1166 return (modlist_lookup(name, 0)); 1167 bestmod = NULL; 1168 for (mod = TAILQ_FIRST(&found_modules); mod; 1169 mod = TAILQ_NEXT(mod, link)) { 1170 if (strcmp(mod->name, name) != 0) 1171 continue; 1172 ver = mod->version; 1173 if (ver == verinfo->md_ver_preferred) 1174 return (mod); 1175 if (ver >= verinfo->md_ver_minimum && 1176 ver <= verinfo->md_ver_maximum && 1177 (bestmod == NULL || ver > bestmod->version)) 1178 bestmod = mod; 1179 } 1180 return (bestmod); 1181 } 1182 1183 static modlist_t 1184 modlist_newmodule(const char *modname, int version, linker_file_t container) 1185 { 1186 modlist_t mod; 1187 1188 mod = malloc(sizeof(struct modlist), M_LINKER, M_NOWAIT | M_ZERO); 1189 if (mod == NULL) 1190 panic("no memory for module list"); 1191 mod->container = container; 1192 mod->name = modname; 1193 mod->version = version; 1194 TAILQ_INSERT_TAIL(&found_modules, mod, link); 1195 return (mod); 1196 } 1197 1198 static void 1199 linker_addmodules(linker_file_t lf, struct mod_metadata **start, 1200 struct mod_metadata **stop, int preload) 1201 { 1202 struct mod_metadata *mp, **mdp; 1203 const char *modname; 1204 int ver; 1205 1206 for (mdp = start; mdp < stop; mdp++) { 1207 mp = *mdp; 1208 if (mp->md_type != MDT_VERSION) 1209 continue; 1210 modname = mp->md_cval; 1211 ver = ((struct mod_version *)mp->md_data)->mv_version; 1212 if (modlist_lookup(modname, ver) != NULL) { 1213 printf("module %s already present!\n", modname); 1214 /* XXX what can we do? this is a build error. :-( */ 1215 continue; 1216 } 1217 modlist_newmodule(modname, ver, lf); 1218 } 1219 } 1220 1221 static void 1222 linker_preload(void *arg) 1223 { 1224 caddr_t modptr; 1225 const char *modname, *nmodname; 1226 char *modtype; 1227 linker_file_t lf; 1228 linker_class_t lc; 1229 int error; 1230 linker_file_list_t loaded_files; 1231 linker_file_list_t depended_files; 1232 struct mod_metadata *mp, *nmp; 1233 struct mod_metadata **start, **stop, **mdp, **nmdp; 1234 struct mod_depend *verinfo; 1235 int nver; 1236 int resolves; 1237 modlist_t mod; 1238 struct sysinit **si_start, **si_stop; 1239 1240 TAILQ_INIT(&loaded_files); 1241 TAILQ_INIT(&depended_files); 1242 TAILQ_INIT(&found_modules); 1243 error = 0; 1244 1245 modptr = NULL; 1246 while ((modptr = preload_search_next_name(modptr)) != NULL) { 1247 modname = (char *)preload_search_info(modptr, MODINFO_NAME); 1248 modtype = (char *)preload_search_info(modptr, MODINFO_TYPE); 1249 if (modname == NULL) { 1250 printf("Preloaded module at %p does not have a" 1251 " name!\n", modptr); 1252 continue; 1253 } 1254 if (modtype == NULL) { 1255 printf("Preloaded module at %p does not have a type!\n", 1256 modptr); 1257 continue; 1258 } 1259 if (bootverbose) 1260 printf("Preloaded %s \"%s\" at %p.\n", modtype, modname, 1261 modptr); 1262 lf = NULL; 1263 TAILQ_FOREACH(lc, &classes, link) { 1264 error = LINKER_LINK_PRELOAD(lc, modname, &lf); 1265 if (!error) 1266 break; 1267 lf = NULL; 1268 } 1269 if (lf) 1270 TAILQ_INSERT_TAIL(&loaded_files, lf, loaded); 1271 } 1272 1273 /* 1274 * First get a list of stuff in the kernel. 1275 */ 1276 if (linker_file_lookup_set(linker_kernel_file, MDT_SETNAME, &start, 1277 &stop, NULL) == 0) 1278 linker_addmodules(linker_kernel_file, start, stop, 1); 1279 1280 /* 1281 * this is a once-off kinky bubble sort resolve relocation dependency 1282 * requirements 1283 */ 1284 restart: 1285 TAILQ_FOREACH(lf, &loaded_files, loaded) { 1286 error = linker_file_lookup_set(lf, MDT_SETNAME, &start, 1287 &stop, NULL); 1288 /* 1289 * First, look to see if we would successfully link with this 1290 * stuff. 1291 */ 1292 resolves = 1; /* unless we know otherwise */ 1293 if (!error) { 1294 for (mdp = start; mdp < stop; mdp++) { 1295 mp = *mdp; 1296 if (mp->md_type != MDT_DEPEND) 1297 continue; 1298 modname = mp->md_cval; 1299 verinfo = mp->md_data; 1300 for (nmdp = start; nmdp < stop; nmdp++) { 1301 nmp = *nmdp; 1302 if (nmp->md_type != MDT_VERSION) 1303 continue; 1304 nmodname = nmp->md_cval; 1305 if (strcmp(modname, nmodname) == 0) 1306 break; 1307 } 1308 if (nmdp < stop) /* it's a self reference */ 1309 continue; 1310 1311 /* 1312 * ok, the module isn't here yet, we 1313 * are not finished 1314 */ 1315 if (modlist_lookup2(modname, verinfo) == NULL) 1316 resolves = 0; 1317 } 1318 } 1319 /* 1320 * OK, if we found our modules, we can link. So, "provide" 1321 * the modules inside and add it to the end of the link order 1322 * list. 1323 */ 1324 if (resolves) { 1325 if (!error) { 1326 for (mdp = start; mdp < stop; mdp++) { 1327 mp = *mdp; 1328 if (mp->md_type != MDT_VERSION) 1329 continue; 1330 modname = mp->md_cval; 1331 nver = ((struct mod_version *) 1332 mp->md_data)->mv_version; 1333 if (modlist_lookup(modname, 1334 nver) != NULL) { 1335 printf("module %s already" 1336 " present!\n", modname); 1337 linker_file_unload(lf, 1338 LINKER_UNLOAD_FORCE); 1339 TAILQ_REMOVE(&loaded_files, 1340 lf, loaded); 1341 /* we changed tailq next ptr */ 1342 goto restart; 1343 } 1344 modlist_newmodule(modname, nver, lf); 1345 } 1346 } 1347 TAILQ_REMOVE(&loaded_files, lf, loaded); 1348 TAILQ_INSERT_TAIL(&depended_files, lf, loaded); 1349 /* 1350 * Since we provided modules, we need to restart the 1351 * sort so that the previous files that depend on us 1352 * have a chance. Also, we've busted the tailq next 1353 * pointer with the REMOVE. 1354 */ 1355 goto restart; 1356 } 1357 } 1358 1359 /* 1360 * At this point, we check to see what could not be resolved.. 1361 */ 1362 TAILQ_FOREACH(lf, &loaded_files, loaded) { 1363 printf("KLD file %s is missing dependencies\n", lf->filename); 1364 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 1365 TAILQ_REMOVE(&loaded_files, lf, loaded); 1366 } 1367 1368 /* 1369 * We made it. Finish off the linking in the order we determined. 1370 */ 1371 TAILQ_FOREACH(lf, &depended_files, loaded) { 1372 if (linker_kernel_file) { 1373 linker_kernel_file->refs++; 1374 error = linker_file_add_dependency(lf, 1375 linker_kernel_file); 1376 if (error) 1377 panic("cannot add dependency"); 1378 } 1379 lf->userrefs++; /* so we can (try to) kldunload it */ 1380 error = linker_file_lookup_set(lf, MDT_SETNAME, &start, 1381 &stop, NULL); 1382 if (!error) { 1383 for (mdp = start; mdp < stop; mdp++) { 1384 mp = *mdp; 1385 if (mp->md_type != MDT_DEPEND) 1386 continue; 1387 modname = mp->md_cval; 1388 verinfo = mp->md_data; 1389 mod = modlist_lookup2(modname, verinfo); 1390 /* Don't count self-dependencies */ 1391 if (lf == mod->container) 1392 continue; 1393 mod->container->refs++; 1394 error = linker_file_add_dependency(lf, 1395 mod->container); 1396 if (error) 1397 panic("cannot add dependency"); 1398 } 1399 } 1400 /* 1401 * Now do relocation etc using the symbol search paths 1402 * established by the dependencies 1403 */ 1404 error = LINKER_LINK_PRELOAD_FINISH(lf); 1405 if (error) { 1406 printf("KLD file %s - could not finalize loading\n", 1407 lf->filename); 1408 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 1409 continue; 1410 } 1411 linker_file_register_modules(lf); 1412 if (linker_file_lookup_set(lf, "sysinit_set", &si_start, 1413 &si_stop, NULL) == 0) 1414 sysinit_add(si_start, si_stop); 1415 linker_file_register_sysctls(lf); 1416 lf->flags |= LINKER_FILE_LINKED; 1417 } 1418 /* woohoo! we made it! */ 1419 } 1420 1421 SYSINIT(preload, SI_SUB_KLD, SI_ORDER_MIDDLE, linker_preload, 0) 1422 1423 /* 1424 * Search for a not-loaded module by name. 1425 * 1426 * Modules may be found in the following locations: 1427 * 1428 * - preloaded (result is just the module name) - on disk (result is full path 1429 * to module) 1430 * 1431 * If the module name is qualified in any way (contains path, etc.) the we 1432 * simply return a copy of it. 1433 * 1434 * The search path can be manipulated via sysctl. Note that we use the ';' 1435 * character as a separator to be consistent with the bootloader. 1436 */ 1437 1438 static char linker_hintfile[] = "linker.hints"; 1439 static char linker_path[MAXPATHLEN] = "/boot/kernel;/boot/modules"; 1440 1441 SYSCTL_STRING(_kern, OID_AUTO, module_path, CTLFLAG_RW, linker_path, 1442 sizeof(linker_path), "module load search path"); 1443 1444 TUNABLE_STR("module_path", linker_path, sizeof(linker_path)); 1445 1446 static char *linker_ext_list[] = { 1447 "", 1448 ".ko", 1449 NULL 1450 }; 1451 1452 /* 1453 * Check if file actually exists either with or without extension listed in 1454 * the linker_ext_list. (probably should be generic for the rest of the 1455 * kernel) 1456 */ 1457 static char * 1458 linker_lookup_file(const char *path, int pathlen, const char *name, 1459 int namelen, struct vattr *vap) 1460 { 1461 struct nameidata nd; 1462 struct thread *td = curthread; /* XXX */ 1463 char *result, **cpp, *sep; 1464 int error, len, extlen, reclen, flags; 1465 enum vtype type; 1466 1467 extlen = 0; 1468 for (cpp = linker_ext_list; *cpp; cpp++) { 1469 len = strlen(*cpp); 1470 if (len > extlen) 1471 extlen = len; 1472 } 1473 extlen++; /* trailing '\0' */ 1474 sep = (path[pathlen - 1] != '/') ? "/" : ""; 1475 1476 reclen = pathlen + strlen(sep) + namelen + extlen + 1; 1477 result = malloc(reclen, M_LINKER, M_WAITOK); 1478 for (cpp = linker_ext_list; *cpp; cpp++) { 1479 snprintf(result, reclen, "%.*s%s%.*s%s", pathlen, path, sep, 1480 namelen, name, *cpp); 1481 /* 1482 * Attempt to open the file, and return the path if 1483 * we succeed and it's a regular file. 1484 */ 1485 NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, result, td); 1486 flags = FREAD; 1487 error = vn_open(&nd, &flags, 0, -1); 1488 if (error == 0) { 1489 NDFREE(&nd, NDF_ONLY_PNBUF); 1490 type = nd.ni_vp->v_type; 1491 if (vap) 1492 VOP_GETATTR(nd.ni_vp, vap, td->td_ucred, td); 1493 VOP_UNLOCK(nd.ni_vp, 0, td); 1494 vn_close(nd.ni_vp, FREAD, td->td_ucred, td); 1495 if (type == VREG) 1496 return (result); 1497 } 1498 } 1499 free(result, M_LINKER); 1500 return (NULL); 1501 } 1502 1503 #define INT_ALIGN(base, ptr) ptr = \ 1504 (base) + (((ptr) - (base) + sizeof(int) - 1) & ~(sizeof(int) - 1)) 1505 1506 /* 1507 * Lookup KLD which contains requested module in the "linker.hints" file. If 1508 * version specification is available, then try to find the best KLD. 1509 * Otherwise just find the latest one. 1510 */ 1511 static char * 1512 linker_hints_lookup(const char *path, int pathlen, const char *modname, 1513 int modnamelen, struct mod_depend *verinfo) 1514 { 1515 struct thread *td = curthread; /* XXX */ 1516 struct ucred *cred = td ? td->td_ucred : NULL; 1517 struct nameidata nd; 1518 struct vattr vattr, mattr; 1519 u_char *hints = NULL; 1520 u_char *cp, *recptr, *bufend, *result, *best, *pathbuf, *sep; 1521 int error, ival, bestver, *intp, reclen, found, flags, clen, blen; 1522 1523 result = NULL; 1524 bestver = found = 0; 1525 1526 sep = (path[pathlen - 1] != '/') ? "/" : ""; 1527 reclen = imax(modnamelen, strlen(linker_hintfile)) + pathlen + 1528 strlen(sep) + 1; 1529 pathbuf = malloc(reclen, M_LINKER, M_WAITOK); 1530 snprintf(pathbuf, reclen, "%.*s%s%s", pathlen, path, sep, 1531 linker_hintfile); 1532 1533 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, pathbuf, td); 1534 flags = FREAD; 1535 error = vn_open(&nd, &flags, 0, -1); 1536 if (error) 1537 goto bad; 1538 NDFREE(&nd, NDF_ONLY_PNBUF); 1539 if (nd.ni_vp->v_type != VREG) 1540 goto bad; 1541 best = cp = NULL; 1542 error = VOP_GETATTR(nd.ni_vp, &vattr, cred, td); 1543 if (error) 1544 goto bad; 1545 /* 1546 * XXX: we need to limit this number to some reasonable value 1547 */ 1548 if (vattr.va_size > 100 * 1024) { 1549 printf("hints file too large %ld\n", (long)vattr.va_size); 1550 goto bad; 1551 } 1552 hints = malloc(vattr.va_size, M_TEMP, M_WAITOK); 1553 if (hints == NULL) 1554 goto bad; 1555 error = vn_rdwr(UIO_READ, nd.ni_vp, (caddr_t)hints, vattr.va_size, 0, 1556 UIO_SYSSPACE, IO_NODELOCKED, cred, NOCRED, &reclen, td); 1557 if (error) 1558 goto bad; 1559 VOP_UNLOCK(nd.ni_vp, 0, td); 1560 vn_close(nd.ni_vp, FREAD, cred, td); 1561 nd.ni_vp = NULL; 1562 if (reclen != 0) { 1563 printf("can't read %d\n", reclen); 1564 goto bad; 1565 } 1566 intp = (int *)hints; 1567 ival = *intp++; 1568 if (ival != LINKER_HINTS_VERSION) { 1569 printf("hints file version mismatch %d\n", ival); 1570 goto bad; 1571 } 1572 bufend = hints + vattr.va_size; 1573 recptr = (u_char *)intp; 1574 clen = blen = 0; 1575 while (recptr < bufend && !found) { 1576 intp = (int *)recptr; 1577 reclen = *intp++; 1578 ival = *intp++; 1579 cp = (char *)intp; 1580 switch (ival) { 1581 case MDT_VERSION: 1582 clen = *cp++; 1583 if (clen != modnamelen || bcmp(cp, modname, clen) != 0) 1584 break; 1585 cp += clen; 1586 INT_ALIGN(hints, cp); 1587 ival = *(int *)cp; 1588 cp += sizeof(int); 1589 clen = *cp++; 1590 if (verinfo == NULL || 1591 ival == verinfo->md_ver_preferred) { 1592 found = 1; 1593 break; 1594 } 1595 if (ival >= verinfo->md_ver_minimum && 1596 ival <= verinfo->md_ver_maximum && 1597 ival > bestver) { 1598 bestver = ival; 1599 best = cp; 1600 blen = clen; 1601 } 1602 break; 1603 default: 1604 break; 1605 } 1606 recptr += reclen + sizeof(int); 1607 } 1608 /* 1609 * Finally check if KLD is in the place 1610 */ 1611 if (found) 1612 result = linker_lookup_file(path, pathlen, cp, clen, &mattr); 1613 else if (best) 1614 result = linker_lookup_file(path, pathlen, best, blen, &mattr); 1615 1616 /* 1617 * KLD is newer than hints file. What we should do now? 1618 */ 1619 if (result && timespeccmp(&mattr.va_mtime, &vattr.va_mtime, >)) 1620 printf("warning: KLD '%s' is newer than the linker.hints" 1621 " file\n", result); 1622 bad: 1623 free(pathbuf, M_LINKER); 1624 if (hints) 1625 free(hints, M_TEMP); 1626 if (nd.ni_vp != NULL) { 1627 VOP_UNLOCK(nd.ni_vp, 0, td); 1628 vn_close(nd.ni_vp, FREAD, cred, td); 1629 } 1630 /* 1631 * If nothing found or hints is absent - fallback to the old 1632 * way by using "kldname[.ko]" as module name. 1633 */ 1634 if (!found && !bestver && result == NULL) 1635 result = linker_lookup_file(path, pathlen, modname, 1636 modnamelen, NULL); 1637 return (result); 1638 } 1639 1640 /* 1641 * Lookup KLD which contains requested module in the all directories. 1642 */ 1643 static char * 1644 linker_search_module(const char *modname, int modnamelen, 1645 struct mod_depend *verinfo) 1646 { 1647 char *cp, *ep, *result; 1648 1649 /* 1650 * traverse the linker path 1651 */ 1652 for (cp = linker_path; *cp; cp = ep + 1) { 1653 /* find the end of this component */ 1654 for (ep = cp; (*ep != 0) && (*ep != ';'); ep++); 1655 result = linker_hints_lookup(cp, ep - cp, modname, 1656 modnamelen, verinfo); 1657 if (result != NULL) 1658 return (result); 1659 if (*ep == 0) 1660 break; 1661 } 1662 return (NULL); 1663 } 1664 1665 /* 1666 * Search for module in all directories listed in the linker_path. 1667 */ 1668 static char * 1669 linker_search_kld(const char *name) 1670 { 1671 char *cp, *ep, *result, **cpp; 1672 int extlen, len; 1673 1674 /* qualified at all? */ 1675 if (index(name, '/')) 1676 return (linker_strdup(name)); 1677 1678 extlen = 0; 1679 for (cpp = linker_ext_list; *cpp; cpp++) { 1680 len = strlen(*cpp); 1681 if (len > extlen) 1682 extlen = len; 1683 } 1684 extlen++; /* trailing '\0' */ 1685 1686 /* traverse the linker path */ 1687 len = strlen(name); 1688 for (ep = linker_path; *ep; ep++) { 1689 cp = ep; 1690 /* find the end of this component */ 1691 for (; *ep != 0 && *ep != ';'; ep++); 1692 result = linker_lookup_file(cp, ep - cp, name, len, NULL); 1693 if (result != NULL) 1694 return (result); 1695 } 1696 return (NULL); 1697 } 1698 1699 static const char * 1700 linker_basename(const char *path) 1701 { 1702 const char *filename; 1703 1704 filename = rindex(path, '/'); 1705 if (filename == NULL) 1706 return path; 1707 if (filename[1]) 1708 filename++; 1709 return (filename); 1710 } 1711 1712 /* 1713 * Find a file which contains given module and load it, if "parent" is not 1714 * NULL, register a reference to it. 1715 */ 1716 int 1717 linker_load_module(const char *kldname, const char *modname, 1718 struct linker_file *parent, struct mod_depend *verinfo, 1719 struct linker_file **lfpp) 1720 { 1721 linker_file_t lfdep; 1722 const char *filename; 1723 char *pathname; 1724 int error; 1725 1726 if (modname == NULL) { 1727 /* 1728 * We have to load KLD 1729 */ 1730 KASSERT(verinfo == NULL, ("linker_load_module: verinfo" 1731 " is not NULL")); 1732 pathname = linker_search_kld(kldname); 1733 } else { 1734 if (modlist_lookup2(modname, verinfo) != NULL) 1735 return (EEXIST); 1736 if (kldname != NULL) 1737 pathname = linker_strdup(kldname); 1738 else if (rootvnode == NULL) 1739 pathname = NULL; 1740 else 1741 /* 1742 * Need to find a KLD with required module 1743 */ 1744 pathname = linker_search_module(modname, 1745 strlen(modname), verinfo); 1746 } 1747 if (pathname == NULL) 1748 return (ENOENT); 1749 1750 /* 1751 * Can't load more than one file with the same basename XXX: 1752 * Actually it should be possible to have multiple KLDs with 1753 * the same basename but different path because they can 1754 * provide different versions of the same modules. 1755 */ 1756 filename = linker_basename(pathname); 1757 if (linker_find_file_by_name(filename)) { 1758 error = EEXIST; 1759 goto out; 1760 } 1761 do { 1762 error = linker_load_file(pathname, &lfdep); 1763 if (error) 1764 break; 1765 if (modname && verinfo && 1766 modlist_lookup2(modname, verinfo) == NULL) { 1767 linker_file_unload(lfdep, LINKER_UNLOAD_FORCE); 1768 error = ENOENT; 1769 break; 1770 } 1771 if (parent) { 1772 error = linker_file_add_dependency(parent, lfdep); 1773 if (error) 1774 break; 1775 } 1776 if (lfpp) 1777 *lfpp = lfdep; 1778 } while (0); 1779 out: 1780 if (pathname) 1781 free(pathname, M_LINKER); 1782 return (error); 1783 } 1784 1785 /* 1786 * This routine is responsible for finding dependencies of userland initiated 1787 * kldload(2)'s of files. 1788 */ 1789 int 1790 linker_load_dependencies(linker_file_t lf) 1791 { 1792 linker_file_t lfdep; 1793 struct mod_metadata **start, **stop, **mdp, **nmdp; 1794 struct mod_metadata *mp, *nmp; 1795 struct mod_depend *verinfo; 1796 modlist_t mod; 1797 const char *modname, *nmodname; 1798 int ver, error = 0, count; 1799 1800 /* 1801 * All files are dependant on /kernel. 1802 */ 1803 if (linker_kernel_file) { 1804 linker_kernel_file->refs++; 1805 error = linker_file_add_dependency(lf, linker_kernel_file); 1806 if (error) 1807 return (error); 1808 } 1809 if (linker_file_lookup_set(lf, MDT_SETNAME, &start, &stop, 1810 &count) != 0) 1811 return (0); 1812 for (mdp = start; mdp < stop; mdp++) { 1813 mp = *mdp; 1814 if (mp->md_type != MDT_VERSION) 1815 continue; 1816 modname = mp->md_cval; 1817 ver = ((struct mod_version *)mp->md_data)->mv_version; 1818 mod = modlist_lookup(modname, ver); 1819 if (mod != NULL) { 1820 printf("interface %s.%d already present in the KLD" 1821 " '%s'!\n", modname, ver, 1822 mod->container->filename); 1823 return (EEXIST); 1824 } 1825 } 1826 1827 for (mdp = start; mdp < stop; mdp++) { 1828 mp = *mdp; 1829 if (mp->md_type != MDT_DEPEND) 1830 continue; 1831 modname = mp->md_cval; 1832 verinfo = mp->md_data; 1833 nmodname = NULL; 1834 for (nmdp = start; nmdp < stop; nmdp++) { 1835 nmp = *nmdp; 1836 if (nmp->md_type != MDT_VERSION) 1837 continue; 1838 nmodname = nmp->md_cval; 1839 if (strcmp(modname, nmodname) == 0) 1840 break; 1841 } 1842 if (nmdp < stop)/* early exit, it's a self reference */ 1843 continue; 1844 mod = modlist_lookup2(modname, verinfo); 1845 if (mod) { /* woohoo, it's loaded already */ 1846 lfdep = mod->container; 1847 lfdep->refs++; 1848 error = linker_file_add_dependency(lf, lfdep); 1849 if (error) 1850 break; 1851 continue; 1852 } 1853 error = linker_load_module(NULL, modname, lf, verinfo, NULL); 1854 if (error) { 1855 printf("KLD %s: depends on %s - not available\n", 1856 lf->filename, modname); 1857 break; 1858 } 1859 } 1860 1861 if (error) 1862 return (error); 1863 linker_addmodules(lf, start, stop, 0); 1864 return (error); 1865 } 1866 1867 static int 1868 sysctl_kern_function_list_iterate(const char *name, void *opaque) 1869 { 1870 struct sysctl_req *req; 1871 1872 req = opaque; 1873 return (SYSCTL_OUT(req, name, strlen(name) + 1)); 1874 } 1875 1876 /* 1877 * Export a nul-separated, double-nul-terminated list of all function names 1878 * in the kernel. 1879 */ 1880 static int 1881 sysctl_kern_function_list(SYSCTL_HANDLER_ARGS) 1882 { 1883 linker_file_t lf; 1884 int error; 1885 1886 #ifdef MAC 1887 error = mac_check_kld_stat(req->td->td_ucred); 1888 if (error) 1889 return (error); 1890 #endif 1891 error = sysctl_wire_old_buffer(req, 0); 1892 if (error != 0) 1893 return (error); 1894 mtx_lock(&kld_mtx); 1895 TAILQ_FOREACH(lf, &linker_files, link) { 1896 error = LINKER_EACH_FUNCTION_NAME(lf, 1897 sysctl_kern_function_list_iterate, req); 1898 if (error) { 1899 mtx_unlock(&kld_mtx); 1900 return (error); 1901 } 1902 } 1903 mtx_unlock(&kld_mtx); 1904 return (SYSCTL_OUT(req, "", 1)); 1905 } 1906 1907 SYSCTL_PROC(_kern, OID_AUTO, function_list, CTLFLAG_RD, 1908 NULL, 0, sysctl_kern_function_list, "", "kernel function list");
Cache object: f82ba50a6375082e05a4240f02ce288e
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