kern_linker.c revision 78161
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 * $FreeBSD: head/sys/kern/kern_linker.c 78161 2001-06-13 10:58:39Z peter $ 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 <sys/module.h> 40#include <sys/linker.h> 41#include <sys/fcntl.h> 42#include <sys/libkern.h> 43#include <sys/namei.h> 44#include <sys/vnode.h> 45#include <sys/sysctl.h> 46 47 48#include "linker_if.h" 49 50#ifdef KLD_DEBUG 51int kld_debug = 0; 52#endif 53 54static char *linker_search_path(const char *name); 55static const char *linker_basename(const char* path); 56 57/* Metadata from the static kernel */ 58SET_DECLARE(modmetadata_set, struct mod_metadata); 59 60MALLOC_DEFINE(M_LINKER, "linker", "kernel linker"); 61 62linker_file_t linker_kernel_file; 63 64static struct lock lock; /* lock for the file list */ 65static linker_class_list_t classes; 66static linker_file_list_t linker_files; 67static int next_file_id = 1; 68 69/* XXX wrong name; we're looking at version provision tags here, not modules */ 70typedef TAILQ_HEAD(, modlist) modlisthead_t; 71struct modlist { 72 TAILQ_ENTRY(modlist) link; /* chain together all modules */ 73 linker_file_t container; 74 const char *name; 75 int version; 76}; 77typedef struct modlist *modlist_t; 78static modlisthead_t found_modules; 79 80static char * 81linker_strdup(const char *str) 82{ 83 char *result; 84 85 if ((result = malloc((strlen(str) + 1), M_LINKER, M_WAITOK)) != NULL) 86 strcpy(result, str); 87 return(result); 88} 89 90static void 91linker_init(void* arg) 92{ 93 lockinit(&lock, PVM, "klink", 0, 0); 94 TAILQ_INIT(&classes); 95 TAILQ_INIT(&linker_files); 96} 97 98SYSINIT(linker, SI_SUB_KLD, SI_ORDER_FIRST, linker_init, 0); 99 100int 101linker_add_class(linker_class_t lc) 102{ 103 kobj_class_compile((kobj_class_t) lc); 104 TAILQ_INSERT_TAIL(&classes, lc, link); 105 return 0; 106} 107 108static void 109linker_file_sysinit(linker_file_t lf) 110{ 111 struct sysinit** start, ** stop; 112 struct sysinit** sipp; 113 struct sysinit** xipp; 114 struct sysinit* save; 115 116 KLD_DPF(FILE, ("linker_file_sysinit: calling SYSINITs for %s\n", 117 lf->filename)); 118 119 if (linker_file_lookup_set(lf, "sysinit_set", &start, &stop, NULL) != 0) 120 return; 121 /* 122 * Perform a bubble sort of the system initialization objects by 123 * their subsystem (primary key) and order (secondary key). 124 * 125 * Since some things care about execution order, this is the 126 * operation which ensures continued function. 127 */ 128 for (sipp = start; sipp < stop; sipp++) { 129 for (xipp = sipp + 1; xipp < stop; xipp++) { 130 if ((*sipp)->subsystem < (*xipp)->subsystem || 131 ((*sipp)->subsystem == (*xipp)->subsystem && 132 (*sipp)->order <= (*xipp)->order)) 133 continue; /* skip*/ 134 save = *sipp; 135 *sipp = *xipp; 136 *xipp = save; 137 } 138 } 139 140 141 /* 142 * Traverse the (now) ordered list of system initialization tasks. 143 * Perform each task, and continue on to the next task. 144 */ 145 for (sipp = start; sipp < stop; sipp++) { 146 if ((*sipp)->subsystem == SI_SUB_DUMMY) 147 continue; /* skip dummy task(s)*/ 148 149 /* Call function */ 150 (*((*sipp)->func))((*sipp)->udata); 151 } 152} 153 154static void 155linker_file_sysuninit(linker_file_t lf) 156{ 157 struct sysinit** start, ** stop; 158 struct sysinit** sipp; 159 struct sysinit** xipp; 160 struct sysinit* save; 161 162 KLD_DPF(FILE, ("linker_file_sysuninit: calling SYSUNINITs for %s\n", 163 lf->filename)); 164 165 if (linker_file_lookup_set(lf, "sysuninit_set", &start, &stop, NULL) != 0) 166 return; 167 168 /* 169 * Perform a reverse bubble sort of the system initialization objects 170 * by their subsystem (primary key) and order (secondary key). 171 * 172 * Since some things care about execution order, this is the 173 * operation which ensures continued function. 174 */ 175 for (sipp = start; sipp < stop; sipp++) { 176 for (xipp = sipp + 1; xipp < stop; xipp++) { 177 if ((*sipp)->subsystem > (*xipp)->subsystem || 178 ((*sipp)->subsystem == (*xipp)->subsystem && 179 (*sipp)->order >= (*xipp)->order)) 180 continue; /* skip*/ 181 save = *sipp; 182 *sipp = *xipp; 183 *xipp = save; 184 } 185 } 186 187 /* 188 * Traverse the (now) ordered list of system initialization tasks. 189 * Perform each task, and continue on to the next task. 190 */ 191 for (sipp = start; sipp < stop; sipp++) { 192 if ((*sipp)->subsystem == SI_SUB_DUMMY) 193 continue; /* skip dummy task(s)*/ 194 195 /* Call function */ 196 (*((*sipp)->func))((*sipp)->udata); 197 } 198} 199 200static void 201linker_file_register_sysctls(linker_file_t lf) 202{ 203 struct sysctl_oid **start, **stop, **oidp; 204 205 KLD_DPF(FILE, ("linker_file_register_sysctls: registering SYSCTLs for %s\n", 206 lf->filename)); 207 208 if (linker_file_lookup_set(lf, "sysctl_set", &start, &stop, NULL) != 0) 209 return; 210 211 for (oidp = start; oidp < stop; oidp++) 212 sysctl_register_oid(*oidp); 213} 214 215static void 216linker_file_unregister_sysctls(linker_file_t lf) 217{ 218 struct sysctl_oid **start, **stop, **oidp; 219 220 KLD_DPF(FILE, ("linker_file_unregister_sysctls: registering SYSCTLs for %s\n", 221 lf->filename)); 222 223 if (linker_file_lookup_set(lf, "sysctl_set", &start, &stop, NULL) != 0) 224 return; 225 226 for (oidp = start; oidp < stop; oidp++) 227 sysctl_unregister_oid(*oidp); 228} 229 230static int 231linker_file_register_modules(linker_file_t lf) 232{ 233 int error; 234 struct mod_metadata **start, **stop; 235 struct mod_metadata **mdp; 236 const moduledata_t *moddata; 237 238 KLD_DPF(FILE, ("linker_file_register_modules: registering modules in %s\n", 239 lf->filename)); 240 241 if (linker_file_lookup_set(lf, "modmetadata_set", &start, &stop, 0) != 0) { 242 /* 243 * This fallback should be unnecessary, but if we get booted from 244 * boot2 instead of loader and we are missing our metadata then 245 * we have to try the best we can. 246 */ 247 if (lf == linker_kernel_file) { 248 start = SET_BEGIN(modmetadata_set); 249 stop = SET_LIMIT(modmetadata_set); 250 } else { 251 return 0; 252 } 253 } 254 for (mdp = start; mdp < stop; mdp++) { 255 if ((*mdp)->md_type != MDT_MODULE) 256 continue; 257 moddata = (*mdp)->md_data; 258 KLD_DPF(FILE, ("Registering module %s in %s\n", 259 moddata->name, lf->filename)); 260 if (module_lookupbyname(moddata->name) != NULL) { 261 printf("Warning: module %s already exists\n", moddata->name); 262 continue; /* or return a error ? */ 263 } 264 error = module_register(moddata, lf); 265 if (error) 266 printf("Module %s failed to register: %d\n", moddata->name, error); 267 } 268 return 0; 269} 270 271static void 272linker_init_kernel_modules(void) 273{ 274 linker_file_register_modules(linker_kernel_file); 275} 276 277SYSINIT(linker_kernel, SI_SUB_KLD, SI_ORDER_ANY, linker_init_kernel_modules, 0); 278 279int 280linker_load_file(const char* filename, linker_file_t* result) 281{ 282 linker_class_t lc; 283 linker_file_t lf; 284 int foundfile, error = 0; 285 286 /* Refuse to load modules if securelevel raised */ 287 if (securelevel > 0) 288 return EPERM; 289 290 lf = linker_find_file_by_name(filename); 291 if (lf) { 292 KLD_DPF(FILE, ("linker_load_file: file %s is already loaded, incrementing refs\n", filename)); 293 *result = lf; 294 lf->refs++; 295 goto out; 296 } 297 298 lf = NULL; 299 foundfile = 0; 300 TAILQ_FOREACH(lc, &classes, link) { 301 KLD_DPF(FILE, ("linker_load_file: trying to load %s as %s\n", 302 filename, lc->desc)); 303 error = LINKER_LOAD_FILE(lc, filename, &lf); 304 /* 305 * If we got something other than ENOENT, then it exists but we cannot 306 * load it for some other reason. 307 */ 308 if (error != ENOENT) 309 foundfile = 1; 310 if (lf) { 311 linker_file_register_modules(lf); 312 linker_file_register_sysctls(lf); 313 linker_file_sysinit(lf); 314 lf->flags |= LINKER_FILE_LINKED; 315 316 *result = lf; 317 error = 0; 318 goto out; 319 } 320 } 321 /* 322 * Less than ideal, but tells the user whether it failed to load or 323 * the module was not found. 324 */ 325 if (foundfile) 326 error = ENOEXEC; /* Format not recognised (or unloadable) */ 327 else 328 error = ENOENT; /* Nothing found */ 329 330out: 331 return error; 332} 333 334linker_file_t 335linker_find_file_by_name(const char* filename) 336{ 337 linker_file_t lf = 0; 338 char *koname; 339 340 koname = malloc(strlen(filename) + 4, M_LINKER, M_WAITOK); 341 if (koname == NULL) 342 goto out; 343 sprintf(koname, "%s.ko", filename); 344 345 lockmgr(&lock, LK_SHARED, 0, curproc); 346 TAILQ_FOREACH(lf, &linker_files, link) { 347 if (!strcmp(lf->filename, koname)) 348 break; 349 if (!strcmp(lf->filename, filename)) 350 break; 351 } 352 lockmgr(&lock, LK_RELEASE, 0, curproc); 353 354out: 355 if (koname) 356 free(koname, M_LINKER); 357 return lf; 358} 359 360linker_file_t 361linker_find_file_by_id(int fileid) 362{ 363 linker_file_t lf = 0; 364 365 lockmgr(&lock, LK_SHARED, 0, curproc); 366 TAILQ_FOREACH(lf, &linker_files, link) 367 if (lf->id == fileid) 368 break; 369 lockmgr(&lock, LK_RELEASE, 0, curproc); 370 371 return lf; 372} 373 374linker_file_t 375linker_make_file(const char* pathname, linker_class_t lc) 376{ 377 linker_file_t lf = 0; 378 const char *filename; 379 380 filename = linker_basename(pathname); 381 382 KLD_DPF(FILE, ("linker_make_file: new file, filename=%s\n", filename)); 383 lockmgr(&lock, LK_EXCLUSIVE, 0, curproc); 384 lf = (linker_file_t) kobj_create((kobj_class_t) lc, M_LINKER, M_WAITOK); 385 if (!lf) 386 goto out; 387 388 lf->refs = 1; 389 lf->userrefs = 0; 390 lf->flags = 0; 391 lf->filename = linker_strdup(filename); 392 lf->id = next_file_id++; 393 lf->ndeps = 0; 394 lf->deps = NULL; 395 STAILQ_INIT(&lf->common); 396 TAILQ_INIT(&lf->modules); 397 398 TAILQ_INSERT_TAIL(&linker_files, lf, link); 399 400out: 401 lockmgr(&lock, LK_RELEASE, 0, curproc); 402 return lf; 403} 404 405int 406linker_file_unload(linker_file_t file) 407{ 408 module_t mod, next; 409 modlist_t ml, nextml; 410 struct common_symbol* cp; 411 int error = 0; 412 int i; 413 414 /* Refuse to unload modules if securelevel raised */ 415 if (securelevel > 0) 416 return EPERM; 417 418 KLD_DPF(FILE, ("linker_file_unload: lf->refs=%d\n", file->refs)); 419 lockmgr(&lock, LK_EXCLUSIVE, 0, curproc); 420 if (file->refs == 1) { 421 KLD_DPF(FILE, ("linker_file_unload: file is unloading, informing modules\n")); 422 /* 423 * Inform any modules associated with this file. 424 */ 425 for (mod = TAILQ_FIRST(&file->modules); mod; mod = next) { 426 next = module_getfnext(mod); 427 428 /* 429 * Give the module a chance to veto the unload. 430 */ 431 if ((error = module_unload(mod)) != 0) { 432 KLD_DPF(FILE, ("linker_file_unload: module %x vetoes unload\n", 433 mod)); 434 lockmgr(&lock, LK_RELEASE, 0, curproc); 435 goto out; 436 } 437 438 module_release(mod); 439 } 440 } 441 442 file->refs--; 443 if (file->refs > 0) { 444 lockmgr(&lock, LK_RELEASE, 0, curproc); 445 goto out; 446 } 447 448 for (ml = TAILQ_FIRST(&found_modules); ml; ml = nextml) { 449 nextml = TAILQ_NEXT(ml, link); 450 if (ml->container == file) { 451 TAILQ_REMOVE(&found_modules, ml, link); 452 } 453 } 454 455 /* Don't try to run SYSUNINITs if we are unloaded due to a link error */ 456 if (file->flags & LINKER_FILE_LINKED) { 457 linker_file_sysuninit(file); 458 linker_file_unregister_sysctls(file); 459 } 460 461 TAILQ_REMOVE(&linker_files, file, link); 462 lockmgr(&lock, LK_RELEASE, 0, curproc); 463 464 if (file->deps) { 465 for (i = 0; i < file->ndeps; i++) 466 linker_file_unload(file->deps[i]); 467 free(file->deps, M_LINKER); 468 file->deps = NULL; 469 } 470 471 for (cp = STAILQ_FIRST(&file->common); cp; 472 cp = STAILQ_FIRST(&file->common)) { 473 STAILQ_REMOVE(&file->common, cp, common_symbol, link); 474 free(cp, M_LINKER); 475 } 476 477 LINKER_UNLOAD(file); 478 if (file->filename) { 479 free(file->filename, M_LINKER); 480 file->filename = NULL; 481 } 482 kobj_delete((kobj_t) file, M_LINKER); 483 484out: 485 return error; 486} 487 488int 489linker_file_add_dependancy(linker_file_t file, linker_file_t dep) 490{ 491 linker_file_t* newdeps; 492 493 newdeps = malloc((file->ndeps + 1) * sizeof(linker_file_t*), 494 M_LINKER, M_WAITOK | M_ZERO); 495 if (newdeps == NULL) 496 return ENOMEM; 497 498 if (file->deps) { 499 bcopy(file->deps, newdeps, file->ndeps * sizeof(linker_file_t*)); 500 free(file->deps, M_LINKER); 501 } 502 file->deps = newdeps; 503 file->deps[file->ndeps] = dep; 504 file->ndeps++; 505 506 return 0; 507} 508 509/* 510 * Locate a linker set and its contents. 511 * This is a helper function to avoid linker_if.h exposure elsewhere. 512 * Note: firstp and lastp are really void *** 513 */ 514int 515linker_file_lookup_set(linker_file_t file, const char *name, 516 void *firstp, void *lastp, int *countp) 517{ 518 519 return LINKER_LOOKUP_SET(file, name, firstp, lastp, countp); 520} 521 522caddr_t 523linker_file_lookup_symbol(linker_file_t file, const char* name, int deps) 524{ 525 c_linker_sym_t sym; 526 linker_symval_t symval; 527 caddr_t address; 528 size_t common_size = 0; 529 int i; 530 531 KLD_DPF(SYM, ("linker_file_lookup_symbol: file=%x, name=%s, deps=%d\n", 532 file, name, deps)); 533 534 if (LINKER_LOOKUP_SYMBOL(file, name, &sym) == 0) { 535 LINKER_SYMBOL_VALUES(file, sym, &symval); 536 if (symval.value == 0) 537 /* 538 * For commons, first look them up in the dependancies and 539 * only allocate space if not found there. 540 */ 541 common_size = symval.size; 542 else { 543 KLD_DPF(SYM, ("linker_file_lookup_symbol: symbol.value=%x\n", symval.value)); 544 return symval.value; 545 } 546 } 547 548 if (deps) { 549 for (i = 0; i < file->ndeps; i++) { 550 address = linker_file_lookup_symbol(file->deps[i], name, 0); 551 if (address) { 552 KLD_DPF(SYM, ("linker_file_lookup_symbol: deps value=%x\n", address)); 553 return address; 554 } 555 } 556 } 557 558 if (common_size > 0) { 559 /* 560 * This is a common symbol which was not found in the 561 * dependancies. We maintain a simple common symbol table in 562 * the file object. 563 */ 564 struct common_symbol* cp; 565 566 STAILQ_FOREACH(cp, &file->common, link) 567 if (!strcmp(cp->name, name)) { 568 KLD_DPF(SYM, ("linker_file_lookup_symbol: old common value=%x\n", cp->address)); 569 return cp->address; 570 } 571 572 /* 573 * Round the symbol size up to align. 574 */ 575 common_size = (common_size + sizeof(int) - 1) & -sizeof(int); 576 cp = malloc(sizeof(struct common_symbol) 577 + common_size 578 + strlen(name) + 1, 579 M_LINKER, M_WAITOK | M_ZERO); 580 if (!cp) { 581 KLD_DPF(SYM, ("linker_file_lookup_symbol: nomem\n")); 582 return 0; 583 } 584 585 cp->address = (caddr_t) (cp + 1); 586 cp->name = cp->address + common_size; 587 strcpy(cp->name, name); 588 bzero(cp->address, common_size); 589 STAILQ_INSERT_TAIL(&file->common, cp, link); 590 591 KLD_DPF(SYM, ("linker_file_lookup_symbol: new common value=%x\n", cp->address)); 592 return cp->address; 593 } 594 595 KLD_DPF(SYM, ("linker_file_lookup_symbol: fail\n")); 596 return 0; 597} 598 599#ifdef DDB 600/* 601 * DDB Helpers. DDB has to look across multiple files with their own 602 * symbol tables and string tables. 603 * 604 * Note that we do not obey list locking protocols here. We really don't 605 * need DDB to hang because somebody's got the lock held. We'll take the 606 * chance that the files list is inconsistant instead. 607 */ 608 609int 610linker_ddb_lookup(const char *symstr, c_linker_sym_t *sym) 611{ 612 linker_file_t lf; 613 614 TAILQ_FOREACH(lf, &linker_files, link) { 615 if (LINKER_LOOKUP_SYMBOL(lf, symstr, sym) == 0) 616 return 0; 617 } 618 return ENOENT; 619} 620 621int 622linker_ddb_search_symbol(caddr_t value, c_linker_sym_t *sym, long *diffp) 623{ 624 linker_file_t lf; 625 u_long off = (uintptr_t)value; 626 u_long diff, bestdiff; 627 c_linker_sym_t best; 628 c_linker_sym_t es; 629 630 best = 0; 631 bestdiff = off; 632 TAILQ_FOREACH(lf, &linker_files, link) { 633 if (LINKER_SEARCH_SYMBOL(lf, value, &es, &diff) != 0) 634 continue; 635 if (es != 0 && diff < bestdiff) { 636 best = es; 637 bestdiff = diff; 638 } 639 if (bestdiff == 0) 640 break; 641 } 642 if (best) { 643 *sym = best; 644 *diffp = bestdiff; 645 return 0; 646 } else { 647 *sym = 0; 648 *diffp = off; 649 return ENOENT; 650 } 651} 652 653int 654linker_ddb_symbol_values(c_linker_sym_t sym, linker_symval_t *symval) 655{ 656 linker_file_t lf; 657 658 TAILQ_FOREACH(lf, &linker_files, link) { 659 if (LINKER_SYMBOL_VALUES(lf, sym, symval) == 0) 660 return 0; 661 } 662 return ENOENT; 663} 664 665#endif 666 667/* 668 * Syscalls. 669 */ 670 671int 672kldload(struct proc* p, struct kldload_args* uap) 673{ 674 char* pathname, *realpath; 675 const char *filename; 676 linker_file_t lf; 677 int error = 0; 678 679 p->p_retval[0] = -1; 680 681 if (securelevel > 0) /* redundant, but that's OK */ 682 return EPERM; 683 684 if ((error = suser(p)) != 0) 685 return error; 686 687 realpath = NULL; 688 pathname = malloc(MAXPATHLEN, M_TEMP, M_WAITOK); 689 if ((error = copyinstr(SCARG(uap, file), pathname, MAXPATHLEN, NULL)) != 0) 690 goto out; 691 692 realpath = linker_search_path(pathname); 693 if (realpath == NULL) { 694 error = ENOENT; 695 goto out; 696 } 697 /* Can't load more than one file with the same name */ 698 filename = linker_basename(realpath); 699 if (linker_find_file_by_name(filename)) { 700 error = EEXIST; 701 goto out; 702 } 703 704 if ((error = linker_load_file(realpath, &lf)) != 0) 705 goto out; 706 707 lf->userrefs++; 708 p->p_retval[0] = lf->id; 709 710out: 711 if (pathname) 712 free(pathname, M_TEMP); 713 if (realpath) 714 free(realpath, M_LINKER); 715 return error; 716} 717 718int 719kldunload(struct proc* p, struct kldunload_args* uap) 720{ 721 linker_file_t lf; 722 int error = 0; 723 724 if (securelevel > 0) /* redundant, but that's OK */ 725 return EPERM; 726 727 if ((error = suser(p)) != 0) 728 return error; 729 730 lf = linker_find_file_by_id(SCARG(uap, fileid)); 731 if (lf) { 732 KLD_DPF(FILE, ("kldunload: lf->userrefs=%d\n", lf->userrefs)); 733 if (lf->userrefs == 0) { 734 printf("kldunload: attempt to unload file that was loaded by the kernel\n"); 735 error = EBUSY; 736 goto out; 737 } 738 lf->userrefs--; 739 error = linker_file_unload(lf); 740 if (error) 741 lf->userrefs++; 742 } else 743 error = ENOENT; 744 745out: 746 return error; 747} 748 749int 750kldfind(struct proc* p, struct kldfind_args* uap) 751{ 752 char* pathname; 753 const char *filename; 754 linker_file_t lf; 755 int error = 0; 756 757 p->p_retval[0] = -1; 758 759 pathname = malloc(MAXPATHLEN, M_TEMP, M_WAITOK); 760 if ((error = copyinstr(SCARG(uap, file), pathname, MAXPATHLEN, NULL)) != 0) 761 goto out; 762 763 filename = linker_basename(pathname); 764 765 lf = linker_find_file_by_name(filename); 766 if (lf) 767 p->p_retval[0] = lf->id; 768 else 769 error = ENOENT; 770 771out: 772 if (pathname) 773 free(pathname, M_TEMP); 774 return error; 775} 776 777int 778kldnext(struct proc* p, struct kldnext_args* uap) 779{ 780 linker_file_t lf; 781 int error = 0; 782 783 if (SCARG(uap, fileid) == 0) { 784 if (TAILQ_FIRST(&linker_files)) 785 p->p_retval[0] = TAILQ_FIRST(&linker_files)->id; 786 else 787 p->p_retval[0] = 0; 788 return 0; 789 } 790 791 lf = linker_find_file_by_id(SCARG(uap, fileid)); 792 if (lf) { 793 if (TAILQ_NEXT(lf, link)) 794 p->p_retval[0] = TAILQ_NEXT(lf, link)->id; 795 else 796 p->p_retval[0] = 0; 797 } else 798 error = ENOENT; 799 800 return error; 801} 802 803int 804kldstat(struct proc* p, struct kldstat_args* uap) 805{ 806 linker_file_t lf; 807 int error = 0; 808 int version; 809 struct kld_file_stat* stat; 810 int namelen; 811 812 lf = linker_find_file_by_id(SCARG(uap, fileid)); 813 if (!lf) { 814 error = ENOENT; 815 goto out; 816 } 817 818 stat = SCARG(uap, stat); 819 820 /* 821 * Check the version of the user's structure. 822 */ 823 if ((error = copyin(&stat->version, &version, sizeof(version))) != 0) 824 goto out; 825 if (version != sizeof(struct kld_file_stat)) { 826 error = EINVAL; 827 goto out; 828 } 829 830 namelen = strlen(lf->filename) + 1; 831 if (namelen > MAXPATHLEN) 832 namelen = MAXPATHLEN; 833 if ((error = copyout(lf->filename, &stat->name[0], namelen)) != 0) 834 goto out; 835 if ((error = copyout(&lf->refs, &stat->refs, sizeof(int))) != 0) 836 goto out; 837 if ((error = copyout(&lf->id, &stat->id, sizeof(int))) != 0) 838 goto out; 839 if ((error = copyout(&lf->address, &stat->address, sizeof(caddr_t))) != 0) 840 goto out; 841 if ((error = copyout(&lf->size, &stat->size, sizeof(size_t))) != 0) 842 goto out; 843 844 p->p_retval[0] = 0; 845 846out: 847 return error; 848} 849 850int 851kldfirstmod(struct proc* p, struct kldfirstmod_args* uap) 852{ 853 linker_file_t lf; 854 int error = 0; 855 856 lf = linker_find_file_by_id(SCARG(uap, fileid)); 857 if (lf) { 858 if (TAILQ_FIRST(&lf->modules)) 859 p->p_retval[0] = module_getid(TAILQ_FIRST(&lf->modules)); 860 else 861 p->p_retval[0] = 0; 862 } else 863 error = ENOENT; 864 865 return error; 866} 867 868int 869kldsym(struct proc *p, struct kldsym_args *uap) 870{ 871 char *symstr = NULL; 872 c_linker_sym_t sym; 873 linker_symval_t symval; 874 linker_file_t lf; 875 struct kld_sym_lookup lookup; 876 int error = 0; 877 878 if ((error = copyin(SCARG(uap, data), &lookup, sizeof(lookup))) != 0) 879 goto out; 880 if (lookup.version != sizeof(lookup) || SCARG(uap, cmd) != KLDSYM_LOOKUP) { 881 error = EINVAL; 882 goto out; 883 } 884 885 symstr = malloc(MAXPATHLEN, M_TEMP, M_WAITOK); 886 if ((error = copyinstr(lookup.symname, symstr, MAXPATHLEN, NULL)) != 0) 887 goto out; 888 889 if (SCARG(uap, fileid) != 0) { 890 lf = linker_find_file_by_id(SCARG(uap, fileid)); 891 if (lf == NULL) { 892 error = ENOENT; 893 goto out; 894 } 895 if (LINKER_LOOKUP_SYMBOL(lf, symstr, &sym) == 0 && 896 LINKER_SYMBOL_VALUES(lf, sym, &symval) == 0) { 897 lookup.symvalue = (uintptr_t)symval.value; 898 lookup.symsize = symval.size; 899 error = copyout(&lookup, SCARG(uap, data), sizeof(lookup)); 900 } else 901 error = ENOENT; 902 } else { 903 TAILQ_FOREACH(lf, &linker_files, link) { 904 if (LINKER_LOOKUP_SYMBOL(lf, symstr, &sym) == 0 && 905 LINKER_SYMBOL_VALUES(lf, sym, &symval) == 0) { 906 lookup.symvalue = (uintptr_t)symval.value; 907 lookup.symsize = symval.size; 908 error = copyout(&lookup, SCARG(uap, data), sizeof(lookup)); 909 break; 910 } 911 } 912 if (!lf) 913 error = ENOENT; 914 } 915out: 916 if (symstr) 917 free(symstr, M_TEMP); 918 return error; 919} 920 921/* 922 * Preloaded module support 923 */ 924 925static modlist_t 926modlist_lookup(const char *name, int ver) 927{ 928 modlist_t mod; 929 930 TAILQ_FOREACH(mod, &found_modules, link) { 931 if (strcmp(mod->name, name) == 0 && (ver == 0 || mod->version == ver)) 932 return mod; 933 } 934 return NULL; 935} 936 937static modlist_t 938modlist_newmodule(char *modname, int version, linker_file_t container) 939{ 940 modlist_t mod; 941 942 mod = malloc(sizeof(struct modlist), M_LINKER, M_NOWAIT); 943 if (mod == NULL) 944 panic("no memory for module list"); 945 bzero(mod, sizeof(*mod)); 946 mod->container = container; 947 mod->name = modname; 948 mod->version = version; 949 TAILQ_INSERT_TAIL(&found_modules, mod, link); 950 return mod; 951} 952 953/* 954 * This routine is cheap and nasty but will work for data pointers. 955 */ 956static void * 957linker_reloc_ptr(linker_file_t lf, void *offset) 958{ 959 return lf->address + (uintptr_t)offset; 960} 961 962/* 963 * Dereference MDT_VERSION metadata into module name and version 964 */ 965static void 966linker_mdt_version(linker_file_t lf, struct mod_metadata *mp, 967 char **modname, int *version) 968{ 969 struct mod_version *mvp; 970 971 if (modname) 972 *modname = linker_reloc_ptr(lf, mp->md_cval); 973 if (version) { 974 mvp = linker_reloc_ptr(lf, mp->md_data); 975 *version = mvp->mv_version; 976 } 977} 978 979/* 980 * Dereference MDT_DEPEND metadata into module name and mod_depend structure 981 */ 982static void 983linker_mdt_depend(linker_file_t lf, struct mod_metadata *mp, 984 char **modname, struct mod_depend **verinfo) 985{ 986 987 if (modname) 988 *modname = linker_reloc_ptr(lf, mp->md_cval); 989 if (verinfo) 990 *verinfo = linker_reloc_ptr(lf, mp->md_data); 991} 992 993static void 994linker_addmodules(linker_file_t lf, struct mod_metadata **start, 995 struct mod_metadata **stop, int preload) 996{ 997 struct mod_metadata *mp, **mdp; 998 char *modname; 999 int ver; 1000 1001 for (mdp = start; mdp < stop; mdp++) { 1002 if (preload) 1003 mp = *mdp; 1004 else 1005 mp = linker_reloc_ptr(lf, *mdp); 1006 if (mp->md_type != MDT_VERSION) 1007 continue; 1008 if (preload) { 1009 modname = mp->md_cval; 1010 ver = ((struct mod_version*)mp->md_data)->mv_version; 1011 } else 1012 linker_mdt_version(lf, mp, &modname, &ver); 1013 if (modlist_lookup(modname, ver) != NULL) { 1014 printf("module %s already present!\n", modname); 1015 /* XXX what can we do? this is a build error. :-( */ 1016 continue; 1017 } 1018 modlist_newmodule(modname, ver, lf); 1019 } 1020} 1021 1022static void 1023linker_preload(void* arg) 1024{ 1025 caddr_t modptr; 1026 char *modname, *nmodname; 1027 char *modtype; 1028 linker_file_t lf; 1029 linker_class_t lc; 1030 int error; 1031 linker_file_list_t loaded_files; 1032 linker_file_list_t depended_files; 1033 struct mod_metadata *mp, *nmp; 1034 struct mod_metadata **start, **stop, **mdp, **nmdp; 1035 struct mod_depend *verinfo; 1036 int nver; 1037 int resolves; 1038 modlist_t mod; 1039 struct sysinit **si_start, **si_stop; 1040 1041 TAILQ_INIT(&loaded_files); 1042 TAILQ_INIT(&depended_files); 1043 TAILQ_INIT(&found_modules); 1044 error = 0; 1045 1046 modptr = NULL; 1047 while ((modptr = preload_search_next_name(modptr)) != NULL) { 1048 modname = (char *)preload_search_info(modptr, MODINFO_NAME); 1049 modtype = (char *)preload_search_info(modptr, MODINFO_TYPE); 1050 if (modname == NULL) { 1051 printf("Preloaded module at %p does not have a name!\n", modptr); 1052 continue; 1053 } 1054 if (modtype == NULL) { 1055 printf("Preloaded module at %p does not have a type!\n", modptr); 1056 continue; 1057 } 1058 printf("Preloaded %s \"%s\" at %p.\n", modtype, modname, modptr); 1059 lf = NULL; 1060 TAILQ_FOREACH(lc, &classes, link) { 1061 error = LINKER_LINK_PRELOAD(lc, modname, &lf); 1062 if (error) { 1063 lf = NULL; 1064 break; 1065 } 1066 } 1067 if (lf) 1068 TAILQ_INSERT_TAIL(&loaded_files, lf, loaded); 1069 } 1070 1071 /* 1072 * First get a list of stuff in the kernel. 1073 */ 1074 if (linker_file_lookup_set(linker_kernel_file, MDT_SETNAME, &start, &stop, 1075 NULL) == 0) 1076 linker_addmodules(linker_kernel_file, start, stop, 1); 1077 1078 /* 1079 * this is a once-off kinky bubble sort 1080 * resolve relocation dependency requirements 1081 */ 1082restart: 1083 TAILQ_FOREACH(lf, &loaded_files, loaded) { 1084 error = linker_file_lookup_set(lf, MDT_SETNAME, &start, &stop, NULL); 1085 /* 1086 * First, look to see if we would successfully link with this stuff. 1087 */ 1088 resolves = 1; /* unless we know otherwise */ 1089 if (!error) { 1090 for (mdp = start; mdp < stop; mdp++) { 1091 mp = linker_reloc_ptr(lf, *mdp); 1092 if (mp->md_type != MDT_DEPEND) 1093 continue; 1094 linker_mdt_depend(lf, mp, &modname, &verinfo); 1095 for (nmdp = start; nmdp < stop; nmdp++) { 1096 nmp = linker_reloc_ptr(lf, *nmdp); 1097 if (nmp->md_type != MDT_VERSION) 1098 continue; 1099 linker_mdt_version(lf, nmp, &nmodname, NULL); 1100 nmodname = linker_reloc_ptr(lf, nmp->md_cval); 1101 if (strcmp(modname, nmodname) == 0) 1102 break; 1103 } 1104 if (nmdp < stop) /* it's a self reference */ 1105 continue; 1106 if (modlist_lookup(modname, 0) == NULL) { 1107 /* ok, the module isn't here yet, we are not finished */ 1108 resolves = 0; 1109 } 1110 } 1111 } 1112 /* 1113 * OK, if we found our modules, we can link. So, "provide" the 1114 * modules inside and add it to the end of the link order list. 1115 */ 1116 if (resolves) { 1117 if (!error) { 1118 for (mdp = start; mdp < stop; mdp++) { 1119 mp = linker_reloc_ptr(lf, *mdp); 1120 if (mp->md_type != MDT_VERSION) 1121 continue; 1122 linker_mdt_version(lf, mp, &modname, &nver); 1123 if (modlist_lookup(modname, nver) != NULL) { 1124 printf("module %s already present!\n", modname); 1125 linker_file_unload(lf); 1126 TAILQ_REMOVE(&loaded_files, lf, loaded); 1127 goto restart; /* we changed the tailq next ptr */ 1128 } 1129 modlist_newmodule(modname, nver, lf); 1130 } 1131 } 1132 TAILQ_REMOVE(&loaded_files, lf, loaded); 1133 TAILQ_INSERT_TAIL(&depended_files, lf, loaded); 1134 /* 1135 * Since we provided modules, we need to restart the sort so 1136 * that the previous files that depend on us have a chance. 1137 * Also, we've busted the tailq next pointer with the REMOVE. 1138 */ 1139 goto restart; 1140 } 1141 } 1142 1143 /* 1144 * At this point, we check to see what could not be resolved.. 1145 */ 1146 TAILQ_FOREACH(lf, &loaded_files, loaded) { 1147 printf("KLD file %s is missing dependencies\n", lf->filename); 1148 linker_file_unload(lf); 1149 TAILQ_REMOVE(&loaded_files, lf, loaded); 1150 } 1151 1152 /* 1153 * We made it. Finish off the linking in the order we determined. 1154 */ 1155 TAILQ_FOREACH(lf, &depended_files, loaded) { 1156 if (linker_kernel_file) { 1157 linker_kernel_file->refs++; 1158 error = linker_file_add_dependancy(lf, linker_kernel_file); 1159 if (error) 1160 panic("cannot add dependency"); 1161 } 1162 lf->userrefs++; /* so we can (try to) kldunload it */ 1163 error = linker_file_lookup_set(lf, MDT_SETNAME, &start, &stop, NULL); 1164 if (!error) { 1165 for (mdp = start; mdp < stop; mdp++) { 1166 mp = linker_reloc_ptr(lf, *mdp); 1167 if (mp->md_type != MDT_DEPEND) 1168 continue; 1169 linker_mdt_depend(lf, mp, &modname, &verinfo); 1170 mod = modlist_lookup(modname, 0); 1171 mod->container->refs++; 1172 error = linker_file_add_dependancy(lf, mod->container); 1173 if (error) 1174 panic("cannot add dependency"); 1175 } 1176 } 1177 1178 /* 1179 * Now do relocation etc using the symbol search paths established by 1180 * the dependencies 1181 */ 1182 error = LINKER_LINK_PRELOAD_FINISH(lf); 1183 if (error) { 1184 printf("KLD file %s - could not finalize loading\n", lf->filename); 1185 linker_file_unload(lf); 1186 continue; 1187 } 1188 1189 linker_file_register_modules(lf); 1190 if (linker_file_lookup_set(lf, "sysinit_set", &si_start, &si_stop, NULL) == 0) 1191 sysinit_add(si_start, si_stop); 1192 linker_file_register_sysctls(lf); 1193 lf->flags |= LINKER_FILE_LINKED; 1194 } 1195 /* woohoo! we made it! */ 1196} 1197 1198SYSINIT(preload, SI_SUB_KLD, SI_ORDER_MIDDLE, linker_preload, 0); 1199 1200/* 1201 * Search for a not-loaded module by name. 1202 * 1203 * Modules may be found in the following locations: 1204 * 1205 * - preloaded (result is just the module name) 1206 * - on disk (result is full path to module) 1207 * 1208 * If the module name is qualified in any way (contains path, etc.) 1209 * the we simply return a copy of it. 1210 * 1211 * The search path can be manipulated via sysctl. Note that we use the ';' 1212 * character as a separator to be consistent with the bootloader. 1213 */ 1214 1215static char linker_path[MAXPATHLEN] = "/boot/modules/;/modules/;/boot/kernel/"; 1216 1217SYSCTL_STRING(_kern, OID_AUTO, module_path, CTLFLAG_RW, linker_path, 1218 sizeof(linker_path), "module load search path"); 1219 1220TUNABLE_STR("module_path", linker_path, sizeof(linker_path)); 1221 1222static char *linker_ext_list[] = { 1223 ".ko", 1224 "", 1225 NULL 1226}; 1227 1228static char * 1229linker_search_path(const char *name) 1230{ 1231 struct nameidata nd; 1232 struct proc *p = curproc; /* XXX */ 1233 char *cp, *ep, *result, **cpp; 1234 int error, extlen, len, flags; 1235 enum vtype type; 1236 1237 /* qualified at all? */ 1238 if (index(name, '/')) 1239 return(linker_strdup(name)); 1240 1241 extlen = 0; 1242 for (cpp = linker_ext_list; *cpp; cpp++) { 1243 len = strlen(*cpp); 1244 if (len > extlen) 1245 extlen = len; 1246 } 1247 extlen++; /* trailing '\0' */ 1248 1249 /* traverse the linker path */ 1250 cp = linker_path; 1251 len = strlen(name); 1252 for (;;) { 1253 1254 /* find the end of this component */ 1255 for (ep = cp; (*ep != 0) && (*ep != ';'); ep++) 1256 ; 1257 result = malloc((len + (ep - cp) + extlen + 1), M_LINKER, M_WAITOK); 1258 if (result == NULL) /* actually ENOMEM */ 1259 return(NULL); 1260 for (cpp = linker_ext_list; *cpp; cpp++) { 1261 strncpy(result, cp, ep - cp); 1262 strcpy(result + (ep - cp), "/"); 1263 strcat(result, name); 1264 strcat(result, *cpp); 1265 /* 1266 * Attempt to open the file, and return the path if we succeed 1267 * and it's a regular file. 1268 */ 1269 NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, result, p); 1270 flags = FREAD; 1271 error = vn_open(&nd, &flags, 0); 1272 if (error == 0) { 1273 NDFREE(&nd, NDF_ONLY_PNBUF); 1274 type = nd.ni_vp->v_type; 1275 VOP_UNLOCK(nd.ni_vp, 0, p); 1276 vn_close(nd.ni_vp, FREAD, p->p_ucred, p); 1277 if (type == VREG) 1278 return(result); 1279 } 1280 } 1281 free(result, M_LINKER); 1282 1283 if (*ep == 0) 1284 break; 1285 cp = ep + 1; 1286 } 1287 return(NULL); 1288} 1289 1290static const char * 1291linker_basename(const char* path) 1292{ 1293 const char *filename; 1294 1295 filename = rindex(path, '/'); 1296 if (filename == NULL) 1297 return path; 1298 if (filename[1]) 1299 filename++; 1300 return filename; 1301} 1302 1303/* 1304 * Find a file which contains given module and load it, 1305 * if "parent" is not NULL, register a reference to it. 1306 */ 1307static int 1308linker_load_module(const char *modname, struct linker_file *parent) 1309{ 1310 linker_file_t lfdep; 1311 const char *filename; 1312 char *pathname; 1313 int error; 1314 1315 /* 1316 * There will be a system to look up or guess a file name from 1317 * a module name. 1318 * For now we just try to load a file with the same name. 1319 */ 1320 pathname = linker_search_path(modname); 1321 if (pathname == NULL) 1322 return ENOENT; 1323 1324 /* Can't load more than one file with the same basename */ 1325 filename = linker_basename(pathname); 1326 if (linker_find_file_by_name(filename)) { 1327 error = EEXIST; 1328 goto out; 1329 } 1330 1331 do { 1332 error = linker_load_file(pathname, &lfdep); 1333 if (error) 1334 break; 1335 if (parent) { 1336 error = linker_file_add_dependancy(parent, lfdep); 1337 if (error) 1338 break; 1339 } 1340 } while(0); 1341out: 1342 if (pathname) 1343 free(pathname, M_LINKER); 1344 return error; 1345} 1346 1347/* 1348 * This routine is responsible for finding dependencies of userland 1349 * initiated kldload(2)'s of files. 1350 */ 1351int 1352linker_load_dependancies(linker_file_t lf) 1353{ 1354 linker_file_t lfdep; 1355 struct mod_metadata **start, **stop, **mdp, **nmdp; 1356 struct mod_metadata *mp, *nmp; 1357 modlist_t mod; 1358 char *modname, *nmodname; 1359 int ver, error = 0, count; 1360 1361 /* 1362 * All files are dependant on /kernel. 1363 */ 1364 if (linker_kernel_file) { 1365 linker_kernel_file->refs++; 1366 error = linker_file_add_dependancy(lf, linker_kernel_file); 1367 if (error) 1368 return error; 1369 } 1370 1371 if (linker_file_lookup_set(lf, MDT_SETNAME, &start, &stop, &count) != 0) 1372 return 0; 1373 for (mdp = start; mdp < stop; mdp++) { 1374 mp = linker_reloc_ptr(lf, *mdp); 1375 if (mp->md_type != MDT_VERSION) 1376 continue; 1377 linker_mdt_version(lf, mp, &modname, &ver); 1378 mod = modlist_lookup(modname, ver); 1379 if (mod != NULL) { 1380 printf("interface %s.%d already present in the KLD '%s'!\n", 1381 modname, ver, mod->container->filename); 1382 return EEXIST; 1383 } 1384 } 1385 1386 for (mdp = start; mdp < stop; mdp++) { 1387 mp = linker_reloc_ptr(lf, *mdp); 1388 if (mp->md_type != MDT_DEPEND) 1389 continue; 1390 modname = linker_reloc_ptr(lf, mp->md_cval); 1391 nmodname = NULL; 1392 for (nmdp = start; nmdp < stop; nmdp++) { 1393 nmp = linker_reloc_ptr(lf, *nmdp); 1394 if (nmp->md_type != MDT_VERSION) 1395 continue; 1396 nmodname = linker_reloc_ptr(lf, nmp->md_cval); 1397 if (strcmp(modname, nmodname) == 0) 1398 break; 1399 } 1400 if (nmdp < stop) /* early exit, it's a self reference */ 1401 continue; 1402 mod = modlist_lookup(modname, 0); 1403 if (mod) { /* woohoo, it's loaded already */ 1404 lfdep = mod->container; 1405 lfdep->refs++; 1406 error = linker_file_add_dependancy(lf, lfdep); 1407 if (error) 1408 break; 1409 continue; 1410 } 1411 error = linker_load_module(modname, lf); 1412 if (error) { 1413 printf("KLD %s: depends on %s - not available\n", 1414 lf->filename, modname); 1415 break; 1416 } 1417 } 1418 1419 if (error) 1420 return error; 1421 linker_addmodules(lf, start, stop, 0); 1422 return error; 1423} 1424