kern_linker.c revision 40162
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 1.8 1998/10/10 00:07:53 peter 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 78 lc->desc = desc; 79 lc->priv = priv; 80 lc->ops = ops; 81 TAILQ_INSERT_HEAD(&classes, lc, link); 82 83 return 0; 84} 85 86static void 87linker_file_sysinit(linker_file_t lf) 88{ 89 struct linker_set* sysinits; 90 struct sysinit** sipp; 91 struct sysinit** xipp; 92 struct sysinit* save; 93 moduledata_t *moddata; 94 95 KLD_DPF(FILE, ("linker_file_sysinit: calling SYSINITs for %s\n", 96 lf->filename)); 97 98 sysinits = (struct linker_set*) 99 linker_file_lookup_symbol(lf, "sysinit_set", 0); 100 101 KLD_DPF(FILE, ("linker_file_sysinit: SYSINITs %p\n", sysinits)); 102 if (!sysinits) 103 return; 104 105 /* HACK ALERT! */ 106 for (sipp = (struct sysinit **)sysinits->ls_items; *sipp; sipp++) { 107 if ((*sipp)->func == module_register_init) { 108 moddata = (*sipp)->udata; 109 moddata->_file = lf; 110 } 111 } 112 113 /* 114 * Perform a bubble sort of the system initialization objects by 115 * their subsystem (primary key) and order (secondary key). 116 * 117 * Since some things care about execution order, this is the 118 * operation which ensures continued function. 119 */ 120 for( sipp = (struct sysinit **)sysinits->ls_items; *sipp; sipp++) { 121 for( xipp = sipp + 1; *xipp; xipp++) { 122 if( (*sipp)->subsystem < (*xipp)->subsystem || 123 ( (*sipp)->subsystem == (*xipp)->subsystem && 124 (*sipp)->order < (*xipp)->order)) 125 continue; /* skip*/ 126 save = *sipp; 127 *sipp = *xipp; 128 *xipp = save; 129 } 130 } 131 132 133 /* 134 * Traverse the (now) ordered list of system initialization tasks. 135 * Perform each task, and continue on to the next task. 136 * 137 * The last item on the list is expected to be the scheduler, 138 * which will not return. 139 */ 140 for( sipp = (struct sysinit **)sysinits->ls_items; *sipp; sipp++) { 141 if( (*sipp)->subsystem == SI_SUB_DUMMY) 142 continue; /* skip dummy task(s)*/ 143 144 switch( (*sipp)->type) { 145 case SI_TYPE_DEFAULT: 146 /* no special processing*/ 147 (*((*sipp)->func))( (*sipp)->udata); 148 break; 149 150 case SI_TYPE_KTHREAD: 151#if !defined(SMP) 152 /* kernel thread*/ 153 if (fork1(&proc0, RFFDG|RFPROC|RFMEM)) 154 panic("fork kernel thread"); 155 cpu_set_fork_handler(pfind(proc0.p_retval[0]), 156 (*sipp)->func, (*sipp)->udata); 157 break; 158#endif 159 160 case SI_TYPE_KPROCESS: 161 /* kernel thread*/ 162 if (fork1(&proc0, RFFDG|RFPROC)) 163 panic("fork kernel process"); 164 cpu_set_fork_handler(pfind(proc0.p_retval[0]), 165 (*sipp)->func, (*sipp)->udata); 166 break; 167 168 default: 169 panic( "linker_file_sysinit: unrecognized init type"); 170 } 171 } 172} 173 174int 175linker_load_file(const char* filename, linker_file_t* result) 176{ 177 linker_class_t lc; 178 linker_file_t lf; 179 int error = 0; 180 181 lf = linker_find_file_by_name(filename); 182 if (lf) { 183 KLD_DPF(FILE, ("linker_load_file: file %s is already loaded, incrementing refs\n", filename)); 184 *result = lf; 185 lf->refs++; 186 goto out; 187 } 188 189 lf = NULL; 190 for (lc = TAILQ_FIRST(&classes); lc; lc = TAILQ_NEXT(lc, link)) { 191 KLD_DPF(FILE, ("linker_load_file: trying to load %s as %s\n", 192 filename, lc->desc)); 193 if (error = lc->ops->load_file(filename, &lf)) 194 goto out; 195 if (lf) { 196 linker_file_sysinit(lf); 197 198 *result = lf; 199 goto out; 200 } 201 } 202 error = ENOEXEC; /* format not recognised */ 203 204out: 205 return error; 206} 207 208linker_file_t 209linker_find_file_by_name(const char* filename) 210{ 211 linker_file_t lf = 0; 212 213 lockmgr(&lock, LK_SHARED, 0, curproc); 214 for (lf = TAILQ_FIRST(&files); lf; lf = TAILQ_NEXT(lf, link)) 215 if (!strcmp(lf->filename, filename)) 216 break; 217 lockmgr(&lock, LK_RELEASE, 0, curproc); 218 219 return lf; 220} 221 222linker_file_t 223linker_find_file_by_id(int fileid) 224{ 225 linker_file_t lf = 0; 226 227 lockmgr(&lock, LK_SHARED, 0, curproc); 228 for (lf = TAILQ_FIRST(&files); lf; lf = TAILQ_NEXT(lf, link)) 229 if (lf->id == fileid) 230 break; 231 lockmgr(&lock, LK_RELEASE, 0, curproc); 232 233 return lf; 234} 235 236linker_file_t 237linker_make_file(const char* pathname, void* priv, struct linker_file_ops* ops) 238{ 239 linker_file_t lf = 0; 240 int namelen; 241 const char *filename; 242 243 filename = rindex(pathname, '/'); 244 if (filename && filename[1]) 245 filename++; 246 else 247 filename = pathname; 248 249 KLD_DPF(FILE, ("linker_make_file: new file, filename=%s\n", filename)); 250 lockmgr(&lock, LK_EXCLUSIVE|LK_RETRY, 0, curproc); 251 namelen = strlen(filename) + 1; 252 lf = malloc(sizeof(struct linker_file) + namelen, M_LINKER, M_WAITOK); 253 if (!lf) 254 goto out; 255 256 lf->refs = 1; 257 lf->userrefs = 0; 258 lf->filename = (char*) (lf + 1); 259 strcpy(lf->filename, filename); 260 lf->id = next_file_id++; 261 lf->ndeps = 0; 262 lf->deps = NULL; 263 STAILQ_INIT(&lf->common); 264 TAILQ_INIT(&lf->modules); 265 266 lf->priv = priv; 267 lf->ops = ops; 268 TAILQ_INSERT_TAIL(&files, lf, link); 269 270out: 271 lockmgr(&lock, LK_RELEASE, 0, curproc); 272 return lf; 273} 274 275int 276linker_file_unload(linker_file_t file) 277{ 278 module_t mod, next; 279 struct common_symbol* cp; 280 int error = 0; 281 int i; 282 283 KLD_DPF(FILE, ("linker_file_unload: lf->refs=%d\n", file->refs)); 284 lockmgr(&lock, LK_EXCLUSIVE|LK_RETRY, 0, curproc); 285 if (file->refs == 1) { 286 KLD_DPF(FILE, ("linker_file_unload: file is unloading, informing modules\n")); 287 /* 288 * Inform any modules associated with this file. 289 */ 290 for (mod = TAILQ_FIRST(&file->modules); mod; mod = next) { 291 next = module_getfnext(mod); 292 293 /* 294 * Give the module a chance to veto the unload. 295 */ 296 if (error = module_unload(mod)) { 297 KLD_DPF(FILE, ("linker_file_unload: module %x vetoes unload\n", 298 mod)); 299 lockmgr(&lock, LK_RELEASE, 0, curproc); 300 goto out; 301 } 302 303 module_release(mod); 304 } 305 } 306 307 file->refs--; 308 if (file->refs > 0) { 309 lockmgr(&lock, LK_RELEASE, 0, curproc); 310 goto out; 311 } 312 313 TAILQ_REMOVE(&files, file, link); 314 lockmgr(&lock, LK_RELEASE, 0, curproc); 315 316 for (i = 0; i < file->ndeps; i++) 317 linker_file_unload(file->deps[i]); 318 free(file->deps, M_LINKER); 319 320 for (cp = STAILQ_FIRST(&file->common); cp; 321 cp = STAILQ_FIRST(&file->common)) { 322 STAILQ_REMOVE(&file->common, cp, common_symbol, link); 323 free(cp, M_LINKER); 324 } 325 326 file->ops->unload(file); 327 free(file, M_LINKER); 328 329out: 330 return error; 331} 332 333int 334linker_file_add_dependancy(linker_file_t file, linker_file_t dep) 335{ 336 linker_file_t* newdeps; 337 338 newdeps = malloc((file->ndeps + 1) * sizeof(linker_file_t*), 339 M_LINKER, M_WAITOK); 340 if (newdeps == NULL) 341 return ENOMEM; 342 343 if (file->deps) { 344 bcopy(file->deps, newdeps, file->ndeps * sizeof(linker_file_t*)); 345 free(file->deps, M_LINKER); 346 } 347 file->deps = newdeps; 348 file->deps[file->ndeps] = dep; 349 file->ndeps++; 350 351 return 0; 352} 353 354caddr_t 355linker_file_lookup_symbol(linker_file_t file, const char* name, int deps) 356{ 357 linker_sym_t sym; 358 linker_symval_t symval; 359 caddr_t address; 360 size_t common_size = 0; 361 int i; 362 363 KLD_DPF(SYM, ("linker_file_lookup_symbol: file=%x, name=%s, deps=%d\n", 364 file, name, deps)); 365 366 if (file->ops->lookup_symbol(file, name, &sym) == 0) { 367 file->ops->symbol_values(file, sym, &symval); 368 if (symval.value == 0) 369 /* 370 * For commons, first look them up in the dependancies and 371 * only allocate space if not found there. 372 */ 373 common_size = symval.size; 374 else { 375 KLD_DPF(SYM, ("linker_file_lookup_symbol: symbol.value=%x\n", symval.value)); 376 return symval.value; 377 } 378 } 379 380 if (deps) 381 for (i = 0; i < file->ndeps; i++) { 382 address = linker_file_lookup_symbol(file->deps[i], name, 0); 383 if (address) { 384 KLD_DPF(SYM, ("linker_file_lookup_symbol: deps value=%x\n", address)); 385 return address; 386 } 387 } 388 389 if (common_size > 0) { 390 /* 391 * This is a common symbol which was not found in the 392 * dependancies. We maintain a simple common symbol table in 393 * the file object. 394 */ 395 struct common_symbol* cp; 396 397 for (cp = STAILQ_FIRST(&file->common); cp; 398 cp = STAILQ_NEXT(cp, link)) 399 if (!strcmp(cp->name, name)) { 400 KLD_DPF(SYM, ("linker_file_lookup_symbol: old common value=%x\n", cp->address)); 401 return cp->address; 402 } 403 404 /* 405 * Round the symbol size up to align. 406 */ 407 common_size = (common_size + sizeof(int) - 1) & -sizeof(int); 408 cp = malloc(sizeof(struct common_symbol) 409 + common_size 410 + strlen(name) + 1, 411 M_LINKER, M_WAITOK); 412 if (!cp) { 413 KLD_DPF(SYM, ("linker_file_lookup_symbol: nomem\n")); 414 return 0; 415 } 416 417 cp->address = (caddr_t) (cp + 1); 418 cp->name = cp->address + common_size; 419 strcpy(cp->name, name); 420 bzero(cp->address, common_size); 421 STAILQ_INSERT_TAIL(&file->common, cp, link); 422 423 KLD_DPF(SYM, ("linker_file_lookup_symbol: new common value=%x\n", cp->address)); 424 return cp->address; 425 } 426 427 KLD_DPF(SYM, ("linker_file_lookup_symbol: fail\n")); 428 return 0; 429} 430 431#ifdef DDB 432/* 433 * DDB Helpers. DDB has to look across multiple files with their own 434 * symbol tables and string tables. 435 * 436 * Note that we do not obey list locking protocols here. We really don't 437 * need DDB to hang because somebody's got the lock held. We'll take the 438 * chance that the files list is inconsistant instead. 439 */ 440 441int 442linker_ddb_lookup(char *symstr, linker_sym_t *sym) 443{ 444 linker_file_t lf; 445 446 for (lf = TAILQ_FIRST(&files); lf; lf = TAILQ_NEXT(lf, link)) { 447 if (lf->ops->lookup_symbol(lf, symstr, sym) == 0) 448 return 0; 449 } 450 return ENOENT; 451} 452 453int 454linker_ddb_search_symbol(caddr_t value, linker_sym_t *sym, long *diffp) 455{ 456 linker_file_t lf; 457 u_long off = (u_long)value; 458 u_long diff, bestdiff; 459 linker_sym_t best; 460 linker_sym_t es; 461 462 best = 0; 463 bestdiff = off; 464 for (lf = TAILQ_FIRST(&files); lf; lf = TAILQ_NEXT(lf, link)) { 465 if (lf->ops->search_symbol(lf, value, &es, &diff) != 0) 466 continue; 467 if (es != 0 && diff < bestdiff) { 468 best = es; 469 bestdiff = diff; 470 } 471 if (bestdiff == 0) 472 break; 473 } 474 if (best) { 475 *sym = best; 476 *diffp = bestdiff; 477 return 0; 478 } else { 479 *sym = 0; 480 *diffp = off; 481 return ENOENT; 482 } 483} 484 485int 486linker_ddb_symbol_values(linker_sym_t sym, linker_symval_t *symval) 487{ 488 linker_file_t lf; 489 490 for (lf = TAILQ_FIRST(&files); lf; lf = TAILQ_NEXT(lf, link)) { 491 if (lf->ops->symbol_values(lf, sym, symval) == 0) 492 return 0; 493 } 494 return ENOENT; 495} 496 497#endif 498 499/* 500 * Syscalls. 501 */ 502 503int 504kldload(struct proc* p, struct kldload_args* uap) 505{ 506 char* filename = NULL; 507 linker_file_t lf; 508 int error = 0; 509 510 p->p_retval[0] = -1; 511 512 if (securelevel > 0) 513 return EPERM; 514 515 if (error = suser(p->p_ucred, &p->p_acflag)) 516 return error; 517 518 filename = malloc(MAXPATHLEN, M_TEMP, M_WAITOK); 519 if (error = copyinstr(SCARG(uap, file), filename, MAXPATHLEN, NULL)) 520 goto out; 521 522 if (error = linker_load_file(uap->file, &lf)) 523 goto out; 524 525 lf->userrefs++; 526 p->p_retval[0] = lf->id; 527 528out: 529 if (filename) 530 free(filename, M_TEMP); 531 return error; 532} 533 534int 535kldunload(struct proc* p, struct kldunload_args* uap) 536{ 537 linker_file_t lf; 538 int error = 0; 539 540 if (securelevel > 0) 541 return EPERM; 542 543 if (error = suser(p->p_ucred, &p->p_acflag)) 544 return error; 545 546 lf = linker_find_file_by_id(SCARG(uap, fileid)); 547 if (lf) { 548 KLD_DPF(FILE, ("kldunload: lf->userrefs=%d\n", lf->userrefs)); 549 if (lf->userrefs == 0) { 550 printf("linkerunload: attempt to unload file which was not loaded by user\n"); 551 error = EBUSY; 552 goto out; 553 } 554 lf->userrefs--; 555 error = linker_file_unload(lf); 556 } else 557 error = ENOENT; 558 559out: 560 return error; 561} 562 563int 564kldfind(struct proc* p, struct kldfind_args* uap) 565{ 566 char* filename = NULL; 567 linker_file_t lf; 568 int error = 0; 569 570 p->p_retval[0] = -1; 571 572 filename = malloc(MAXPATHLEN, M_TEMP, M_WAITOK); 573 if (error = copyinstr(SCARG(uap, file), filename, MAXPATHLEN, NULL)) 574 goto out; 575 576 lf = linker_find_file_by_name(filename); 577 if (lf) 578 p->p_retval[0] = lf->id; 579 else 580 error = ENOENT; 581 582out: 583 if (filename) 584 free(filename, M_TEMP); 585 return error; 586} 587 588int 589kldnext(struct proc* p, struct kldnext_args* uap) 590{ 591 linker_file_t lf; 592 int error = 0; 593 594 if (SCARG(uap, fileid) == 0) { 595 if (TAILQ_FIRST(&files)) 596 p->p_retval[0] = TAILQ_FIRST(&files)->id; 597 else 598 p->p_retval[0] = 0; 599 return 0; 600 } 601 602 lf = linker_find_file_by_id(SCARG(uap, fileid)); 603 if (lf) { 604 if (TAILQ_NEXT(lf, link)) 605 p->p_retval[0] = TAILQ_NEXT(lf, link)->id; 606 else 607 p->p_retval[0] = 0; 608 } else 609 error = ENOENT; 610 611 return error; 612} 613 614int 615kldstat(struct proc* p, struct kldstat_args* uap) 616{ 617 linker_file_t lf; 618 int error = 0; 619 int version; 620 struct kld_file_stat* stat; 621 int namelen; 622 623 lf = linker_find_file_by_id(SCARG(uap, fileid)); 624 if (!lf) { 625 error = ENOENT; 626 goto out; 627 } 628 629 stat = SCARG(uap, stat); 630 631 /* 632 * Check the version of the user's structure. 633 */ 634 if (error = copyin(&stat->version, &version, sizeof(version))) 635 goto out; 636 if (version != sizeof(struct kld_file_stat)) { 637 error = EINVAL; 638 goto out; 639 } 640 641 namelen = strlen(lf->filename) + 1; 642 if (namelen > MAXPATHLEN) 643 namelen = MAXPATHLEN; 644 if (error = copyout(lf->filename, &stat->name[0], namelen)) 645 goto out; 646 if (error = copyout(&lf->refs, &stat->refs, sizeof(int))) 647 goto out; 648 if (error = copyout(&lf->id, &stat->id, sizeof(int))) 649 goto out; 650 if (error = copyout(&lf->address, &stat->address, sizeof(caddr_t))) 651 goto out; 652 if (error = copyout(&lf->size, &stat->size, sizeof(size_t))) 653 goto out; 654 655 p->p_retval[0] = 0; 656 657out: 658 return error; 659} 660 661int 662kldfirstmod(struct proc* p, struct kldfirstmod_args* uap) 663{ 664 linker_file_t lf; 665 int error = 0; 666 667 lf = linker_find_file_by_id(SCARG(uap, fileid)); 668 if (lf) { 669 if (TAILQ_FIRST(&lf->modules)) 670 p->p_retval[0] = module_getid(TAILQ_FIRST(&lf->modules)); 671 else 672 p->p_retval[0] = 0; 673 } else 674 error = ENOENT; 675 676 return error; 677} 678 679/* 680 * Preloaded module support 681 */ 682 683static void 684linker_preload(void* arg) 685{ 686 caddr_t modptr; 687 char *modname; 688 char *modtype; 689 linker_file_t lf; 690 linker_class_t lc; 691 int error; 692 struct linker_set *sysinits; 693 struct sysinit **sipp; 694 moduledata_t *moddata; 695 696 modptr = NULL; 697 while ((modptr = preload_search_next_name(modptr)) != NULL) { 698 modname = (char *)preload_search_info(modptr, MODINFO_NAME); 699 modtype = (char *)preload_search_info(modptr, MODINFO_TYPE); 700 if (modname == NULL) { 701 printf("Preloaded module at 0x%p does not have a name!\n", modptr); 702 continue; 703 } 704 if (modtype == NULL) { 705 printf("Preloaded module at 0x%p does not have a type!\n", modptr); 706 continue; 707 } 708 printf("Preloaded %s \"%s\" at 0x%p.\n", modtype, modname, modptr); 709 lf = linker_find_file_by_name(modname); 710 if (lf) { 711 lf->userrefs++; 712 continue; 713 } 714 lf = NULL; 715 for (lc = TAILQ_FIRST(&classes); lc; lc = TAILQ_NEXT(lc, link)) { 716 error = lc->ops->load_file(modname, &lf); 717 if (error) { 718 lf = NULL; 719 break; 720 } 721 } 722 if (lf) { 723 lf->userrefs++; 724 725 sysinits = (struct linker_set*) 726 linker_file_lookup_symbol(lf, "sysinit_set", 0); 727 if (sysinits) { 728 /* HACK ALERT! 729 * This is to set the sysinit moduledata so that the module 730 * can attach itself to the correct containing file. 731 * The sysinit could be run at *any* time. 732 */ 733 for (sipp = (struct sysinit **)sysinits->ls_items; *sipp; sipp++) { 734 if ((*sipp)->func == module_register_init) { 735 moddata = (*sipp)->udata; 736 moddata->_file = lf; 737 } 738 } 739 sysinit_add((struct sysinit **)sysinits->ls_items); 740 } 741 742 break; 743 } 744 } 745} 746 747SYSINIT(preload, SI_SUB_KLD, SI_ORDER_MIDDLE, linker_preload, 0); 748 749/* 750 * Search for a not-loaded module by name. 751 * 752 * Modules may be found in the following locations: 753 * 754 * - preloaded (result is just the module name) 755 * - on disk (result is full path to module) 756 * 757 * If the module name is qualified in any way (contains path, etc.) 758 * the we simply return a copy of it. 759 * 760 * The search path can be manipulated via sysctl. Note that we use the ';' 761 * character as a separator to be consistent with the bootloader. 762 */ 763 764static char linker_path[MAXPATHLEN + 1] = "/;/boot/;/modules/"; 765 766SYSCTL_STRING(_kern, OID_AUTO, module_path, CTLFLAG_RW, linker_path, 767 sizeof(linker_path), "module load search path"); 768 769static char * 770linker_strdup(const char *str) 771{ 772 char *result; 773 774 if ((result = malloc((strlen(str) + 1), M_LINKER, M_WAITOK)) != NULL) 775 strcpy(result, str); 776 return(result); 777} 778 779char * 780linker_search_path(const char *name) 781{ 782 struct nameidata nd; 783 struct proc *p = curproc; /* XXX */ 784 char *cp, *ep, *result; 785 int error; 786 enum vtype type; 787 788 /* qualified at all? */ 789 if (index(name, '/')) 790 return(linker_strdup(name)); 791 792 /* traverse the linker path */ 793 cp = linker_path; 794 for (;;) { 795 796 /* find the end of this component */ 797 for (ep = cp; (*ep != 0) && (*ep != ';'); ep++) 798 ; 799 result = malloc((strlen(name) + (ep - cp) + 1), M_LINKER, M_WAITOK); 800 if (result == NULL) /* actually ENOMEM */ 801 return(NULL); 802 803 strncpy(result, cp, ep - cp); 804 strcpy(result + (ep - cp), name); 805 806 /* 807 * Attempt to open the file, and return the path if we succeed and it's 808 * a regular file. 809 */ 810 NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, result, p); 811 error = vn_open(&nd, FREAD, 0); 812 if (error == 0) { 813 type = nd.ni_vp->v_type; 814 VOP_UNLOCK(nd.ni_vp, 0, p); 815 vn_close(nd.ni_vp, FREAD, p->p_ucred, p); 816 if (type == VREG) 817 return(result); 818 } 819 free(result, M_LINKER); 820 821 if (*ep == 0) 822 break; 823 cp = ep + 1; 824 } 825 return(NULL); 826} 827