kern_linker.c revision 40859
1/*- 2 * Copyright (c) 1997 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 * $Id: kern_linker.c,v 1.11 1998/10/24 18:35:09 msmith Exp $ 27 */ 28 29#include "opt_ddb.h" 30 31#include <sys/param.h> 32#include <sys/kernel.h> 33#include <sys/systm.h> 34#include <sys/malloc.h> 35#include <sys/sysproto.h> 36#include <sys/sysent.h> 37#include <sys/proc.h> 38#include <sys/lock.h> 39#include <machine/cpu.h> 40#include <machine/bootinfo.h> 41#include <sys/module.h> 42#include <sys/linker.h> 43#include <sys/unistd.h> 44#include <sys/fcntl.h> 45#include <sys/libkern.h> 46#include <sys/namei.h> 47#include <sys/vnode.h> 48#include <sys/sysctl.h> 49 50MALLOC_DEFINE(M_LINKER, "kld", "kernel linker"); 51linker_file_t linker_current_file; 52 53static struct lock lock; /* lock for the file list */ 54static linker_class_list_t classes; 55static linker_file_list_t files; 56static int next_file_id = 1; 57 58static void 59linker_init(void* arg) 60{ 61 lockinit(&lock, PVM, "klink", 0, 0); 62 TAILQ_INIT(&classes); 63 TAILQ_INIT(&files); 64} 65 66SYSINIT(linker, SI_SUB_KLD, SI_ORDER_FIRST, linker_init, 0); 67 68int 69linker_add_class(const char* desc, void* priv, 70 struct linker_class_ops* ops) 71{ 72 linker_class_t lc; 73 74 lc = malloc(sizeof(struct linker_class), M_LINKER, M_NOWAIT); 75 if (!lc) 76 return ENOMEM; 77 bzero(lc, sizeof(*lc)); 78 79 lc->desc = desc; 80 lc->priv = priv; 81 lc->ops = ops; 82 TAILQ_INSERT_HEAD(&classes, lc, link); 83 84 return 0; 85} 86 87static void 88linker_file_sysinit(linker_file_t lf) 89{ 90 struct linker_set* sysinits; 91 struct sysinit** sipp; 92 struct sysinit** xipp; 93 struct sysinit* save; 94 moduledata_t *moddata; 95 96 KLD_DPF(FILE, ("linker_file_sysinit: calling SYSINITs for %s\n", 97 lf->filename)); 98 99 sysinits = (struct linker_set*) 100 linker_file_lookup_symbol(lf, "sysinit_set", 0); 101 102 KLD_DPF(FILE, ("linker_file_sysinit: SYSINITs %p\n", sysinits)); 103 if (!sysinits) 104 return; 105 106 /* HACK ALERT! */ 107 for (sipp = (struct sysinit **)sysinits->ls_items; *sipp; sipp++) { 108 if ((*sipp)->func == module_register_init) { 109 moddata = (*sipp)->udata; 110 moddata->_file = lf; 111 } 112 } 113 114 /* 115 * Perform a bubble sort of the system initialization objects by 116 * their subsystem (primary key) and order (secondary key). 117 * 118 * Since some things care about execution order, this is the 119 * operation which ensures continued function. 120 */ 121 for( sipp = (struct sysinit **)sysinits->ls_items; *sipp; sipp++) { 122 for( xipp = sipp + 1; *xipp; xipp++) { 123 if( (*sipp)->subsystem < (*xipp)->subsystem || 124 ( (*sipp)->subsystem == (*xipp)->subsystem && 125 (*sipp)->order < (*xipp)->order)) 126 continue; /* skip*/ 127 save = *sipp; 128 *sipp = *xipp; 129 *xipp = save; 130 } 131 } 132 133 134 /* 135 * Traverse the (now) ordered list of system initialization tasks. 136 * Perform each task, and continue on to the next task. 137 * 138 * The last item on the list is expected to be the scheduler, 139 * which will not return. 140 */ 141 for( sipp = (struct sysinit **)sysinits->ls_items; *sipp; sipp++) { 142 if( (*sipp)->subsystem == SI_SUB_DUMMY) 143 continue; /* skip dummy task(s)*/ 144 145 switch( (*sipp)->type) { 146 case SI_TYPE_DEFAULT: 147 /* no special processing*/ 148 (*((*sipp)->func))( (*sipp)->udata); 149 break; 150 151 case SI_TYPE_KTHREAD: 152#if !defined(SMP) 153 /* kernel thread*/ 154 if (fork1(&proc0, RFFDG|RFPROC|RFMEM)) 155 panic("fork kernel thread"); 156 cpu_set_fork_handler(pfind(proc0.p_retval[0]), 157 (*sipp)->func, (*sipp)->udata); 158 break; 159#endif 160 161 case SI_TYPE_KPROCESS: 162 /* kernel thread*/ 163 if (fork1(&proc0, RFFDG|RFPROC)) 164 panic("fork kernel process"); 165 cpu_set_fork_handler(pfind(proc0.p_retval[0]), 166 (*sipp)->func, (*sipp)->udata); 167 break; 168 169 default: 170 panic( "linker_file_sysinit: unrecognized init type"); 171 } 172 } 173} 174 175int 176linker_load_file(const char* filename, linker_file_t* result) 177{ 178 linker_class_t lc; 179 linker_file_t lf; 180 int error = 0; 181 182 lf = linker_find_file_by_name(filename); 183 if (lf) { 184 KLD_DPF(FILE, ("linker_load_file: file %s is already loaded, incrementing refs\n", filename)); 185 *result = lf; 186 lf->refs++; 187 goto out; 188 } 189 190 lf = NULL; 191 for (lc = TAILQ_FIRST(&classes); lc; lc = TAILQ_NEXT(lc, link)) { 192 KLD_DPF(FILE, ("linker_load_file: trying to load %s as %s\n", 193 filename, lc->desc)); 194 if (error = lc->ops->load_file(filename, &lf)) 195 goto out; 196 if (lf) { 197 linker_file_sysinit(lf); 198 199 *result = lf; 200 goto out; 201 } 202 } 203 error = ENOEXEC; /* format not recognised */ 204 205out: 206 return error; 207} 208 209linker_file_t 210linker_find_file_by_name(const char* filename) 211{ 212 linker_file_t lf = 0; 213 214 lockmgr(&lock, LK_SHARED, 0, curproc); 215 for (lf = TAILQ_FIRST(&files); lf; lf = TAILQ_NEXT(lf, link)) 216 if (!strcmp(lf->filename, filename)) 217 break; 218 lockmgr(&lock, LK_RELEASE, 0, curproc); 219 220 return lf; 221} 222 223linker_file_t 224linker_find_file_by_id(int fileid) 225{ 226 linker_file_t lf = 0; 227 228 lockmgr(&lock, LK_SHARED, 0, curproc); 229 for (lf = TAILQ_FIRST(&files); lf; lf = TAILQ_NEXT(lf, link)) 230 if (lf->id == fileid) 231 break; 232 lockmgr(&lock, LK_RELEASE, 0, curproc); 233 234 return lf; 235} 236 237linker_file_t 238linker_make_file(const char* pathname, void* priv, struct linker_file_ops* ops) 239{ 240 linker_file_t lf = 0; 241 int namelen; 242 const char *filename; 243 244 filename = rindex(pathname, '/'); 245 if (filename && filename[1]) 246 filename++; 247 else 248 filename = pathname; 249 250 KLD_DPF(FILE, ("linker_make_file: new file, filename=%s\n", filename)); 251 lockmgr(&lock, LK_EXCLUSIVE|LK_RETRY, 0, curproc); 252 namelen = strlen(filename) + 1; 253 lf = malloc(sizeof(struct linker_file) + namelen, M_LINKER, M_WAITOK); 254 if (!lf) 255 goto out; 256 bzero(lf, sizeof(*lf)); 257 258 lf->refs = 1; 259 lf->userrefs = 0; 260 lf->filename = (char*) (lf + 1); 261 strcpy(lf->filename, filename); 262 lf->id = next_file_id++; 263 lf->ndeps = 0; 264 lf->deps = NULL; 265 STAILQ_INIT(&lf->common); 266 TAILQ_INIT(&lf->modules); 267 268 lf->priv = priv; 269 lf->ops = ops; 270 TAILQ_INSERT_TAIL(&files, lf, link); 271 272out: 273 lockmgr(&lock, LK_RELEASE, 0, curproc); 274 return lf; 275} 276 277int 278linker_file_unload(linker_file_t file) 279{ 280 module_t mod, next; 281 struct common_symbol* cp; 282 int error = 0; 283 int i; 284 285 KLD_DPF(FILE, ("linker_file_unload: lf->refs=%d\n", file->refs)); 286 lockmgr(&lock, LK_EXCLUSIVE|LK_RETRY, 0, curproc); 287 if (file->refs == 1) { 288 KLD_DPF(FILE, ("linker_file_unload: file is unloading, informing modules\n")); 289 /* 290 * Inform any modules associated with this file. 291 */ 292 for (mod = TAILQ_FIRST(&file->modules); mod; mod = next) { 293 next = module_getfnext(mod); 294 295 /* 296 * Give the module a chance to veto the unload. 297 */ 298 if (error = module_unload(mod)) { 299 KLD_DPF(FILE, ("linker_file_unload: module %x vetoes unload\n", 300 mod)); 301 lockmgr(&lock, LK_RELEASE, 0, curproc); 302 goto out; 303 } 304 305 module_release(mod); 306 } 307 } 308 309 file->refs--; 310 if (file->refs > 0) { 311 lockmgr(&lock, LK_RELEASE, 0, curproc); 312 goto out; 313 } 314 315 TAILQ_REMOVE(&files, file, link); 316 lockmgr(&lock, LK_RELEASE, 0, curproc); 317 318 for (i = 0; i < file->ndeps; i++) 319 linker_file_unload(file->deps[i]); 320 free(file->deps, M_LINKER); 321 322 for (cp = STAILQ_FIRST(&file->common); cp; 323 cp = STAILQ_FIRST(&file->common)) { 324 STAILQ_REMOVE(&file->common, cp, common_symbol, link); 325 free(cp, M_LINKER); 326 } 327 328 file->ops->unload(file); 329 free(file, M_LINKER); 330 331out: 332 return error; 333} 334 335int 336linker_file_add_dependancy(linker_file_t file, linker_file_t dep) 337{ 338 linker_file_t* newdeps; 339 340 newdeps = malloc((file->ndeps + 1) * sizeof(linker_file_t*), 341 M_LINKER, M_WAITOK); 342 if (newdeps == NULL) 343 return ENOMEM; 344 bzero(newdeps, (file->ndeps + 1) * sizeof(linker_file_t*)); 345 346 if (file->deps) { 347 bcopy(file->deps, newdeps, file->ndeps * sizeof(linker_file_t*)); 348 free(file->deps, M_LINKER); 349 } 350 file->deps = newdeps; 351 file->deps[file->ndeps] = dep; 352 file->ndeps++; 353 354 return 0; 355} 356 357caddr_t 358linker_file_lookup_symbol(linker_file_t file, const char* name, int deps) 359{ 360 linker_sym_t sym; 361 linker_symval_t symval; 362 caddr_t address; 363 size_t common_size = 0; 364 int i; 365 366 KLD_DPF(SYM, ("linker_file_lookup_symbol: file=%x, name=%s, deps=%d\n", 367 file, name, deps)); 368 369 if (file->ops->lookup_symbol(file, name, &sym) == 0) { 370 file->ops->symbol_values(file, sym, &symval); 371 if (symval.value == 0) 372 /* 373 * For commons, first look them up in the dependancies and 374 * only allocate space if not found there. 375 */ 376 common_size = symval.size; 377 else { 378 KLD_DPF(SYM, ("linker_file_lookup_symbol: symbol.value=%x\n", symval.value)); 379 return symval.value; 380 } 381 } 382 383 if (deps) 384 for (i = 0; i < file->ndeps; i++) { 385 address = linker_file_lookup_symbol(file->deps[i], name, 0); 386 if (address) { 387 KLD_DPF(SYM, ("linker_file_lookup_symbol: deps value=%x\n", address)); 388 return address; 389 } 390 } 391 392 if (common_size > 0) { 393 /* 394 * This is a common symbol which was not found in the 395 * dependancies. We maintain a simple common symbol table in 396 * the file object. 397 */ 398 struct common_symbol* cp; 399 400 for (cp = STAILQ_FIRST(&file->common); cp; 401 cp = STAILQ_NEXT(cp, link)) 402 if (!strcmp(cp->name, name)) { 403 KLD_DPF(SYM, ("linker_file_lookup_symbol: old common value=%x\n", cp->address)); 404 return cp->address; 405 } 406 407 /* 408 * Round the symbol size up to align. 409 */ 410 common_size = (common_size + sizeof(int) - 1) & -sizeof(int); 411 cp = malloc(sizeof(struct common_symbol) 412 + common_size 413 + strlen(name) + 1, 414 M_LINKER, M_WAITOK); 415 if (!cp) { 416 KLD_DPF(SYM, ("linker_file_lookup_symbol: nomem\n")); 417 return 0; 418 } 419 bzero(cp, sizeof(struct common_symbol) + common_size + strlen(name)+ 1); 420 421 cp->address = (caddr_t) (cp + 1); 422 cp->name = cp->address + common_size; 423 strcpy(cp->name, name); 424 bzero(cp->address, common_size); 425 STAILQ_INSERT_TAIL(&file->common, cp, link); 426 427 KLD_DPF(SYM, ("linker_file_lookup_symbol: new common value=%x\n", cp->address)); 428 return cp->address; 429 } 430 431 KLD_DPF(SYM, ("linker_file_lookup_symbol: fail\n")); 432 return 0; 433} 434 435#ifdef DDB 436/* 437 * DDB Helpers. DDB has to look across multiple files with their own 438 * symbol tables and string tables. 439 * 440 * Note that we do not obey list locking protocols here. We really don't 441 * need DDB to hang because somebody's got the lock held. We'll take the 442 * chance that the files list is inconsistant instead. 443 */ 444 445int 446linker_ddb_lookup(char *symstr, linker_sym_t *sym) 447{ 448 linker_file_t lf; 449 450 for (lf = TAILQ_FIRST(&files); lf; lf = TAILQ_NEXT(lf, link)) { 451 if (lf->ops->lookup_symbol(lf, symstr, sym) == 0) 452 return 0; 453 } 454 return ENOENT; 455} 456 457int 458linker_ddb_search_symbol(caddr_t value, linker_sym_t *sym, long *diffp) 459{ 460 linker_file_t lf; 461 u_long off = (u_long)value; 462 u_long diff, bestdiff; 463 linker_sym_t best; 464 linker_sym_t es; 465 466 best = 0; 467 bestdiff = off; 468 for (lf = TAILQ_FIRST(&files); lf; lf = TAILQ_NEXT(lf, link)) { 469 if (lf->ops->search_symbol(lf, value, &es, &diff) != 0) 470 continue; 471 if (es != 0 && diff < bestdiff) { 472 best = es; 473 bestdiff = diff; 474 } 475 if (bestdiff == 0) 476 break; 477 } 478 if (best) { 479 *sym = best; 480 *diffp = bestdiff; 481 return 0; 482 } else { 483 *sym = 0; 484 *diffp = off; 485 return ENOENT; 486 } 487} 488 489int 490linker_ddb_symbol_values(linker_sym_t sym, linker_symval_t *symval) 491{ 492 linker_file_t lf; 493 494 for (lf = TAILQ_FIRST(&files); lf; lf = TAILQ_NEXT(lf, link)) { 495 if (lf->ops->symbol_values(lf, sym, symval) == 0) 496 return 0; 497 } 498 return ENOENT; 499} 500 501#endif 502 503/* 504 * Syscalls. 505 */ 506 507int 508kldload(struct proc* p, struct kldload_args* uap) 509{ 510 char* filename = NULL; 511 linker_file_t lf; 512 int error = 0; 513 514 p->p_retval[0] = -1; 515 516 if (securelevel > 0) 517 return EPERM; 518 519 if (error = suser(p->p_ucred, &p->p_acflag)) 520 return error; 521 522 filename = malloc(MAXPATHLEN, M_TEMP, M_WAITOK); 523 if (error = copyinstr(SCARG(uap, file), filename, MAXPATHLEN, NULL)) 524 goto out; 525 526 if (error = linker_load_file(filename, &lf)) 527 goto out; 528 529 lf->userrefs++; 530 p->p_retval[0] = lf->id; 531 532out: 533 if (filename) 534 free(filename, M_TEMP); 535 return error; 536} 537 538int 539kldunload(struct proc* p, struct kldunload_args* uap) 540{ 541 linker_file_t lf; 542 int error = 0; 543 544 if (securelevel > 0) 545 return EPERM; 546 547 if (error = suser(p->p_ucred, &p->p_acflag)) 548 return error; 549 550 lf = linker_find_file_by_id(SCARG(uap, fileid)); 551 if (lf) { 552 KLD_DPF(FILE, ("kldunload: lf->userrefs=%d\n", lf->userrefs)); 553 if (lf->userrefs == 0) { 554 printf("linkerunload: attempt to unload file which was not loaded by user\n"); 555 error = EBUSY; 556 goto out; 557 } 558 lf->userrefs--; 559 error = linker_file_unload(lf); 560 } else 561 error = ENOENT; 562 563out: 564 return error; 565} 566 567int 568kldfind(struct proc* p, struct kldfind_args* uap) 569{ 570 char* filename = NULL; 571 linker_file_t lf; 572 int error = 0; 573 574 p->p_retval[0] = -1; 575 576 filename = malloc(MAXPATHLEN, M_TEMP, M_WAITOK); 577 if (error = copyinstr(SCARG(uap, file), filename, MAXPATHLEN, NULL)) 578 goto out; 579 580 lf = linker_find_file_by_name(filename); 581 if (lf) 582 p->p_retval[0] = lf->id; 583 else 584 error = ENOENT; 585 586out: 587 if (filename) 588 free(filename, M_TEMP); 589 return error; 590} 591 592int 593kldnext(struct proc* p, struct kldnext_args* uap) 594{ 595 linker_file_t lf; 596 int error = 0; 597 598 if (SCARG(uap, fileid) == 0) { 599 if (TAILQ_FIRST(&files)) 600 p->p_retval[0] = TAILQ_FIRST(&files)->id; 601 else 602 p->p_retval[0] = 0; 603 return 0; 604 } 605 606 lf = linker_find_file_by_id(SCARG(uap, fileid)); 607 if (lf) { 608 if (TAILQ_NEXT(lf, link)) 609 p->p_retval[0] = TAILQ_NEXT(lf, link)->id; 610 else 611 p->p_retval[0] = 0; 612 } else 613 error = ENOENT; 614 615 return error; 616} 617 618int 619kldstat(struct proc* p, struct kldstat_args* uap) 620{ 621 linker_file_t lf; 622 int error = 0; 623 int version; 624 struct kld_file_stat* stat; 625 int namelen; 626 627 lf = linker_find_file_by_id(SCARG(uap, fileid)); 628 if (!lf) { 629 error = ENOENT; 630 goto out; 631 } 632 633 stat = SCARG(uap, stat); 634 635 /* 636 * Check the version of the user's structure. 637 */ 638 if (error = copyin(&stat->version, &version, sizeof(version))) 639 goto out; 640 if (version != sizeof(struct kld_file_stat)) { 641 error = EINVAL; 642 goto out; 643 } 644 645 namelen = strlen(lf->filename) + 1; 646 if (namelen > MAXPATHLEN) 647 namelen = MAXPATHLEN; 648 if (error = copyout(lf->filename, &stat->name[0], namelen)) 649 goto out; 650 if (error = copyout(&lf->refs, &stat->refs, sizeof(int))) 651 goto out; 652 if (error = copyout(&lf->id, &stat->id, sizeof(int))) 653 goto out; 654 if (error = copyout(&lf->address, &stat->address, sizeof(caddr_t))) 655 goto out; 656 if (error = copyout(&lf->size, &stat->size, sizeof(size_t))) 657 goto out; 658 659 p->p_retval[0] = 0; 660 661out: 662 return error; 663} 664 665int 666kldfirstmod(struct proc* p, struct kldfirstmod_args* uap) 667{ 668 linker_file_t lf; 669 int error = 0; 670 671 lf = linker_find_file_by_id(SCARG(uap, fileid)); 672 if (lf) { 673 if (TAILQ_FIRST(&lf->modules)) 674 p->p_retval[0] = module_getid(TAILQ_FIRST(&lf->modules)); 675 else 676 p->p_retval[0] = 0; 677 } else 678 error = ENOENT; 679 680 return error; 681} 682 683/* 684 * Preloaded module support 685 */ 686 687static void 688linker_preload(void* arg) 689{ 690 caddr_t modptr; 691 char *modname; 692 char *modtype; 693 linker_file_t lf; 694 linker_class_t lc; 695 int error; 696 struct linker_set *sysinits; 697 struct sysinit **sipp; 698 moduledata_t *moddata; 699 700 modptr = NULL; 701 while ((modptr = preload_search_next_name(modptr)) != NULL) { 702 modname = (char *)preload_search_info(modptr, MODINFO_NAME); 703 modtype = (char *)preload_search_info(modptr, MODINFO_TYPE); 704 if (modname == NULL) { 705 printf("Preloaded module at %p does not have a name!\n", modptr); 706 continue; 707 } 708 if (modtype == NULL) { 709 printf("Preloaded module at %p does not have a type!\n", modptr); 710 continue; 711 } 712 printf("Preloaded %s \"%s\" at %p.\n", modtype, modname, modptr); 713 lf = linker_find_file_by_name(modname); 714 if (lf) { 715 lf->userrefs++; 716 continue; 717 } 718 lf = NULL; 719 for (lc = TAILQ_FIRST(&classes); lc; lc = TAILQ_NEXT(lc, link)) { 720 error = lc->ops->load_file(modname, &lf); 721 if (error) { 722 lf = NULL; 723 break; 724 } 725 } 726 if (lf) { 727 lf->userrefs++; 728 729 sysinits = (struct linker_set*) 730 linker_file_lookup_symbol(lf, "sysinit_set", 0); 731 if (sysinits) { 732 /* HACK ALERT! 733 * This is to set the sysinit moduledata so that the module 734 * can attach itself to the correct containing file. 735 * The sysinit could be run at *any* time. 736 */ 737 for (sipp = (struct sysinit **)sysinits->ls_items; *sipp; sipp++) { 738 if ((*sipp)->func == module_register_init) { 739 moddata = (*sipp)->udata; 740 moddata->_file = lf; 741 } 742 } 743 sysinit_add((struct sysinit **)sysinits->ls_items); 744 } 745 } 746 } 747} 748 749SYSINIT(preload, SI_SUB_KLD, SI_ORDER_MIDDLE, linker_preload, 0); 750 751/* 752 * Search for a not-loaded module by name. 753 * 754 * Modules may be found in the following locations: 755 * 756 * - preloaded (result is just the module name) 757 * - on disk (result is full path to module) 758 * 759 * If the module name is qualified in any way (contains path, etc.) 760 * the we simply return a copy of it. 761 * 762 * The search path can be manipulated via sysctl. Note that we use the ';' 763 * character as a separator to be consistent with the bootloader. 764 */ 765 766static char linker_path[MAXPATHLEN + 1] = "/;/boot/;/modules/"; 767 768SYSCTL_STRING(_kern, OID_AUTO, module_path, CTLFLAG_RW, linker_path, 769 sizeof(linker_path), "module load search path"); 770 771static char * 772linker_strdup(const char *str) 773{ 774 char *result; 775 776 if ((result = malloc((strlen(str) + 1), M_LINKER, M_WAITOK)) != NULL) 777 strcpy(result, str); 778 return(result); 779} 780 781char * 782linker_search_path(const char *name) 783{ 784 struct nameidata nd; 785 struct proc *p = curproc; /* XXX */ 786 char *cp, *ep, *result; 787 int error; 788 enum vtype type; 789 790 /* qualified at all? */ 791 if (index(name, '/')) 792 return(linker_strdup(name)); 793 794 /* traverse the linker path */ 795 cp = linker_path; 796 for (;;) { 797 798 /* find the end of this component */ 799 for (ep = cp; (*ep != 0) && (*ep != ';'); ep++) 800 ; 801 result = malloc((strlen(name) + (ep - cp) + 1), M_LINKER, M_WAITOK); 802 if (result == NULL) /* actually ENOMEM */ 803 return(NULL); 804 805 strncpy(result, cp, ep - cp); 806 strcpy(result + (ep - cp), name); 807 808 /* 809 * Attempt to open the file, and return the path if we succeed and it's 810 * a regular file. 811 */ 812 NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, result, p); 813 error = vn_open(&nd, FREAD, 0); 814 if (error == 0) { 815 type = nd.ni_vp->v_type; 816 VOP_UNLOCK(nd.ni_vp, 0, p); 817 vn_close(nd.ni_vp, FREAD, p->p_ucred, p); 818 if (type == VREG) 819 return(result); 820 } 821 free(result, M_LINKER); 822 823 if (*ep == 0) 824 break; 825 cp = ep + 1; 826 } 827 return(NULL); 828} 829