kern_linker.c revision 178284
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: head/sys/kern/kern_linker.c 178284 2008-04-17 19:19:40Z pjd $"); 29 30#include "opt_ddb.h" 31#include "opt_hwpmc_hooks.h" 32#include "opt_mac.h" 33 34#include <sys/param.h> 35#include <sys/kernel.h> 36#include <sys/systm.h> 37#include <sys/malloc.h> 38#include <sys/sysproto.h> 39#include <sys/sysent.h> 40#include <sys/priv.h> 41#include <sys/proc.h> 42#include <sys/lock.h> 43#include <sys/mutex.h> 44#include <sys/sx.h> 45#include <sys/module.h> 46#include <sys/mount.h> 47#include <sys/linker.h> 48#include <sys/fcntl.h> 49#include <sys/libkern.h> 50#include <sys/namei.h> 51#include <sys/vnode.h> 52#include <sys/syscallsubr.h> 53#include <sys/sysctl.h> 54 55#include <security/mac/mac_framework.h> 56 57#include "linker_if.h" 58 59#ifdef HWPMC_HOOKS 60#include <sys/pmckern.h> 61#endif 62 63#ifdef KLD_DEBUG 64int kld_debug = 0; 65#endif 66 67#define KLD_LOCK() sx_xlock(&kld_sx) 68#define KLD_UNLOCK() sx_xunlock(&kld_sx) 69#define KLD_LOCKED() sx_xlocked(&kld_sx) 70#define KLD_LOCK_ASSERT() do { \ 71 if (!cold) \ 72 sx_assert(&kld_sx, SX_XLOCKED); \ 73} while (0) 74 75/* 76 * static char *linker_search_path(const char *name, struct mod_depend 77 * *verinfo); 78 */ 79static const char *linker_basename(const char *path); 80 81/* 82 * Find a currently loaded file given its filename. 83 */ 84static linker_file_t linker_find_file_by_name(const char* _filename); 85 86/* 87 * Find a currently loaded file given its file id. 88 */ 89static linker_file_t linker_find_file_by_id(int _fileid); 90 91/* Metadata from the static kernel */ 92SET_DECLARE(modmetadata_set, struct mod_metadata); 93 94MALLOC_DEFINE(M_LINKER, "linker", "kernel linker"); 95 96linker_file_t linker_kernel_file; 97 98static struct sx kld_sx; /* kernel linker lock */ 99 100/* 101 * Load counter used by clients to determine if a linker file has been 102 * re-loaded. This counter is incremented for each file load. 103 */ 104static int loadcnt; 105 106static linker_class_list_t classes; 107static linker_file_list_t linker_files; 108static int next_file_id = 1; 109static int linker_no_more_classes = 0; 110 111#define LINKER_GET_NEXT_FILE_ID(a) do { \ 112 linker_file_t lftmp; \ 113 \ 114 KLD_LOCK_ASSERT(); \ 115retry: \ 116 TAILQ_FOREACH(lftmp, &linker_files, link) { \ 117 if (next_file_id == lftmp->id) { \ 118 next_file_id++; \ 119 goto retry; \ 120 } \ 121 } \ 122 (a) = next_file_id; \ 123} while(0) 124 125 126/* XXX wrong name; we're looking at version provision tags here, not modules */ 127typedef TAILQ_HEAD(, modlist) modlisthead_t; 128struct modlist { 129 TAILQ_ENTRY(modlist) link; /* chain together all modules */ 130 linker_file_t container; 131 const char *name; 132 int version; 133}; 134typedef struct modlist *modlist_t; 135static modlisthead_t found_modules; 136 137static int linker_file_add_dependency(linker_file_t file, 138 linker_file_t dep); 139static caddr_t linker_file_lookup_symbol_internal(linker_file_t file, 140 const char* name, int deps); 141static int linker_load_module(const char *kldname, 142 const char *modname, struct linker_file *parent, 143 struct mod_depend *verinfo, struct linker_file **lfpp); 144static modlist_t modlist_lookup2(const char *name, struct mod_depend *verinfo); 145 146static char * 147linker_strdup(const char *str) 148{ 149 char *result; 150 151 if ((result = malloc((strlen(str) + 1), M_LINKER, M_WAITOK)) != NULL) 152 strcpy(result, str); 153 return (result); 154} 155 156static void 157linker_init(void *arg) 158{ 159 160 sx_init(&kld_sx, "kernel linker"); 161 TAILQ_INIT(&classes); 162 TAILQ_INIT(&linker_files); 163} 164 165SYSINIT(linker, SI_SUB_KLD, SI_ORDER_FIRST, linker_init, 0); 166 167static void 168linker_stop_class_add(void *arg) 169{ 170 171 linker_no_more_classes = 1; 172} 173 174SYSINIT(linker_class, SI_SUB_KLD, SI_ORDER_ANY, linker_stop_class_add, NULL); 175 176int 177linker_add_class(linker_class_t lc) 178{ 179 180 /* 181 * We disallow any class registration past SI_ORDER_ANY 182 * of SI_SUB_KLD. We bump the reference count to keep the 183 * ops from being freed. 184 */ 185 if (linker_no_more_classes == 1) 186 return (EPERM); 187 kobj_class_compile((kobj_class_t) lc); 188 ((kobj_class_t)lc)->refs++; /* XXX: kobj_mtx */ 189 TAILQ_INSERT_TAIL(&classes, lc, link); 190 return (0); 191} 192 193static void 194linker_file_sysinit(linker_file_t lf) 195{ 196 struct sysinit **start, **stop, **sipp, **xipp, *save; 197 198 KLD_DPF(FILE, ("linker_file_sysinit: calling SYSINITs for %s\n", 199 lf->filename)); 200 201 if (linker_file_lookup_set(lf, "sysinit_set", &start, &stop, NULL) != 0) 202 return; 203 /* 204 * Perform a bubble sort of the system initialization objects by 205 * their subsystem (primary key) and order (secondary key). 206 * 207 * Since some things care about execution order, this is the operation 208 * which ensures continued function. 209 */ 210 for (sipp = start; sipp < stop; sipp++) { 211 for (xipp = sipp + 1; xipp < stop; xipp++) { 212 if ((*sipp)->subsystem < (*xipp)->subsystem || 213 ((*sipp)->subsystem == (*xipp)->subsystem && 214 (*sipp)->order <= (*xipp)->order)) 215 continue; /* skip */ 216 save = *sipp; 217 *sipp = *xipp; 218 *xipp = save; 219 } 220 } 221 222 /* 223 * Traverse the (now) ordered list of system initialization tasks. 224 * Perform each task, and continue on to the next task. 225 */ 226 mtx_lock(&Giant); 227 for (sipp = start; sipp < stop; sipp++) { 228 if ((*sipp)->subsystem == SI_SUB_DUMMY) 229 continue; /* skip dummy task(s) */ 230 231 /* Call function */ 232 (*((*sipp)->func)) ((*sipp)->udata); 233 } 234 mtx_unlock(&Giant); 235} 236 237static void 238linker_file_sysuninit(linker_file_t lf) 239{ 240 struct sysinit **start, **stop, **sipp, **xipp, *save; 241 242 KLD_DPF(FILE, ("linker_file_sysuninit: calling SYSUNINITs for %s\n", 243 lf->filename)); 244 245 if (linker_file_lookup_set(lf, "sysuninit_set", &start, &stop, 246 NULL) != 0) 247 return; 248 249 /* 250 * Perform a reverse bubble sort of the system initialization objects 251 * by their subsystem (primary key) and order (secondary key). 252 * 253 * Since some things care about execution order, this is the operation 254 * which ensures continued function. 255 */ 256 for (sipp = start; sipp < stop; sipp++) { 257 for (xipp = sipp + 1; xipp < stop; xipp++) { 258 if ((*sipp)->subsystem > (*xipp)->subsystem || 259 ((*sipp)->subsystem == (*xipp)->subsystem && 260 (*sipp)->order >= (*xipp)->order)) 261 continue; /* skip */ 262 save = *sipp; 263 *sipp = *xipp; 264 *xipp = save; 265 } 266 } 267 268 /* 269 * Traverse the (now) ordered list of system initialization tasks. 270 * Perform each task, and continue on to the next task. 271 */ 272 mtx_lock(&Giant); 273 for (sipp = start; sipp < stop; sipp++) { 274 if ((*sipp)->subsystem == SI_SUB_DUMMY) 275 continue; /* skip dummy task(s) */ 276 277 /* Call function */ 278 (*((*sipp)->func)) ((*sipp)->udata); 279 } 280 mtx_unlock(&Giant); 281} 282 283static void 284linker_file_register_sysctls(linker_file_t lf) 285{ 286 struct sysctl_oid **start, **stop, **oidp; 287 288 KLD_DPF(FILE, 289 ("linker_file_register_sysctls: registering SYSCTLs for %s\n", 290 lf->filename)); 291 292 if (linker_file_lookup_set(lf, "sysctl_set", &start, &stop, NULL) != 0) 293 return; 294 295 mtx_lock(&Giant); 296 for (oidp = start; oidp < stop; oidp++) 297 sysctl_register_oid(*oidp); 298 mtx_unlock(&Giant); 299} 300 301static void 302linker_file_unregister_sysctls(linker_file_t lf) 303{ 304 struct sysctl_oid **start, **stop, **oidp; 305 306 KLD_DPF(FILE, ("linker_file_unregister_sysctls: registering SYSCTLs" 307 " for %s\n", lf->filename)); 308 309 if (linker_file_lookup_set(lf, "sysctl_set", &start, &stop, NULL) != 0) 310 return; 311 312 mtx_lock(&Giant); 313 for (oidp = start; oidp < stop; oidp++) 314 sysctl_unregister_oid(*oidp); 315 mtx_unlock(&Giant); 316} 317 318static int 319linker_file_register_modules(linker_file_t lf) 320{ 321 struct mod_metadata **start, **stop, **mdp; 322 const moduledata_t *moddata; 323 int first_error, error; 324 325 KLD_DPF(FILE, ("linker_file_register_modules: registering modules" 326 " in %s\n", lf->filename)); 327 328 if (linker_file_lookup_set(lf, "modmetadata_set", &start, 329 &stop, NULL) != 0) { 330 /* 331 * This fallback should be unnecessary, but if we get booted 332 * from boot2 instead of loader and we are missing our 333 * metadata then we have to try the best we can. 334 */ 335 if (lf == linker_kernel_file) { 336 start = SET_BEGIN(modmetadata_set); 337 stop = SET_LIMIT(modmetadata_set); 338 } else 339 return (0); 340 } 341 first_error = 0; 342 for (mdp = start; mdp < stop; mdp++) { 343 if ((*mdp)->md_type != MDT_MODULE) 344 continue; 345 moddata = (*mdp)->md_data; 346 KLD_DPF(FILE, ("Registering module %s in %s\n", 347 moddata->name, lf->filename)); 348 error = module_register(moddata, lf); 349 if (error) { 350 printf("Module %s failed to register: %d\n", 351 moddata->name, error); 352 if (first_error == 0) 353 first_error = error; 354 } 355 } 356 return (first_error); 357} 358 359static void 360linker_init_kernel_modules(void) 361{ 362 363 linker_file_register_modules(linker_kernel_file); 364} 365 366SYSINIT(linker_kernel, SI_SUB_KLD, SI_ORDER_ANY, linker_init_kernel_modules, 367 0); 368 369static int 370linker_load_file(const char *filename, linker_file_t *result) 371{ 372 linker_class_t lc; 373 linker_file_t lf; 374 int foundfile, error; 375 376 /* Refuse to load modules if securelevel raised */ 377 if (securelevel > 0) 378 return (EPERM); 379 380 KLD_LOCK_ASSERT(); 381 lf = linker_find_file_by_name(filename); 382 if (lf) { 383 KLD_DPF(FILE, ("linker_load_file: file %s is already loaded," 384 " incrementing refs\n", filename)); 385 *result = lf; 386 lf->refs++; 387 return (0); 388 } 389 foundfile = 0; 390 error = 0; 391 392 /* 393 * We do not need to protect (lock) classes here because there is 394 * no class registration past startup (SI_SUB_KLD, SI_ORDER_ANY) 395 * and there is no class deregistration mechanism at this time. 396 */ 397 TAILQ_FOREACH(lc, &classes, link) { 398 KLD_DPF(FILE, ("linker_load_file: trying to load %s\n", 399 filename)); 400 error = LINKER_LOAD_FILE(lc, filename, &lf); 401 /* 402 * If we got something other than ENOENT, then it exists but 403 * we cannot load it for some other reason. 404 */ 405 if (error != ENOENT) 406 foundfile = 1; 407 if (lf) { 408 error = linker_file_register_modules(lf); 409 if (error == EEXIST) { 410 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 411 return (error); 412 } 413 KLD_UNLOCK(); 414 linker_file_register_sysctls(lf); 415 linker_file_sysinit(lf); 416 KLD_LOCK(); 417 lf->flags |= LINKER_FILE_LINKED; 418 *result = lf; 419 return (0); 420 } 421 } 422 /* 423 * Less than ideal, but tells the user whether it failed to load or 424 * the module was not found. 425 */ 426 if (foundfile) { 427 /* 428 * Format not recognized or otherwise unloadable. 429 * When loading a module that is statically built into 430 * the kernel EEXIST percolates back up as the return 431 * value. Preserve this so that apps like sysinstall 432 * can recognize this special case and not post bogus 433 * dialog boxes. 434 */ 435 if (error != EEXIST) 436 error = ENOEXEC; 437 } else 438 error = ENOENT; /* Nothing found */ 439 return (error); 440} 441 442int 443linker_reference_module(const char *modname, struct mod_depend *verinfo, 444 linker_file_t *result) 445{ 446 modlist_t mod; 447 int error; 448 449 KLD_LOCK(); 450 if ((mod = modlist_lookup2(modname, verinfo)) != NULL) { 451 *result = mod->container; 452 (*result)->refs++; 453 KLD_UNLOCK(); 454 return (0); 455 } 456 457 error = linker_load_module(NULL, modname, NULL, verinfo, result); 458 KLD_UNLOCK(); 459 return (error); 460} 461 462int 463linker_release_module(const char *modname, struct mod_depend *verinfo, 464 linker_file_t lf) 465{ 466 modlist_t mod; 467 int error; 468 469 KLD_LOCK(); 470 if (lf == NULL) { 471 KASSERT(modname != NULL, 472 ("linker_release_module: no file or name")); 473 mod = modlist_lookup2(modname, verinfo); 474 if (mod == NULL) { 475 KLD_UNLOCK(); 476 return (ESRCH); 477 } 478 lf = mod->container; 479 } else 480 KASSERT(modname == NULL && verinfo == NULL, 481 ("linker_release_module: both file and name")); 482 error = linker_file_unload(lf, LINKER_UNLOAD_NORMAL); 483 KLD_UNLOCK(); 484 return (error); 485} 486 487static linker_file_t 488linker_find_file_by_name(const char *filename) 489{ 490 linker_file_t lf; 491 char *koname; 492 493 koname = malloc(strlen(filename) + 4, M_LINKER, M_WAITOK); 494 sprintf(koname, "%s.ko", filename); 495 496 KLD_LOCK_ASSERT(); 497 TAILQ_FOREACH(lf, &linker_files, link) { 498 if (strcmp(lf->filename, koname) == 0) 499 break; 500 if (strcmp(lf->filename, filename) == 0) 501 break; 502 } 503 free(koname, M_LINKER); 504 return (lf); 505} 506 507static linker_file_t 508linker_find_file_by_id(int fileid) 509{ 510 linker_file_t lf; 511 512 KLD_LOCK_ASSERT(); 513 TAILQ_FOREACH(lf, &linker_files, link) 514 if (lf->id == fileid && lf->flags & LINKER_FILE_LINKED) 515 break; 516 return (lf); 517} 518 519int 520linker_file_foreach(linker_predicate_t *predicate, void *context) 521{ 522 linker_file_t lf; 523 int retval = 0; 524 525 KLD_LOCK(); 526 TAILQ_FOREACH(lf, &linker_files, link) { 527 retval = predicate(lf, context); 528 if (retval != 0) 529 break; 530 } 531 KLD_UNLOCK(); 532 return (retval); 533} 534 535linker_file_t 536linker_make_file(const char *pathname, linker_class_t lc) 537{ 538 linker_file_t lf; 539 const char *filename; 540 541 KLD_LOCK_ASSERT(); 542 filename = linker_basename(pathname); 543 544 KLD_DPF(FILE, ("linker_make_file: new file, filename='%s' for pathname='%s'\n", filename, pathname)); 545 lf = (linker_file_t)kobj_create((kobj_class_t)lc, M_LINKER, M_WAITOK); 546 if (lf == NULL) 547 return (NULL); 548 lf->refs = 1; 549 lf->userrefs = 0; 550 lf->flags = 0; 551 lf->filename = linker_strdup(filename); 552 lf->pathname = linker_strdup(pathname); 553 LINKER_GET_NEXT_FILE_ID(lf->id); 554 lf->ndeps = 0; 555 lf->deps = NULL; 556 lf->loadcnt = ++loadcnt; 557 lf->sdt_probes = NULL; 558 lf->sdt_nprobes = 0; 559 STAILQ_INIT(&lf->common); 560 TAILQ_INIT(&lf->modules); 561 TAILQ_INSERT_TAIL(&linker_files, lf, link); 562 return (lf); 563} 564 565int 566linker_file_unload(linker_file_t file, int flags) 567{ 568 module_t mod, next; 569 modlist_t ml, nextml; 570 struct common_symbol *cp; 571 int error, i; 572 573 /* Refuse to unload modules if securelevel raised. */ 574 if (securelevel > 0) 575 return (EPERM); 576 577 KLD_LOCK_ASSERT(); 578 KLD_DPF(FILE, ("linker_file_unload: lf->refs=%d\n", file->refs)); 579 580 /* Easy case of just dropping a reference. */ 581 if (file->refs > 1) { 582 file->refs--; 583 return (0); 584 } 585 586 KLD_DPF(FILE, ("linker_file_unload: file is unloading," 587 " informing modules\n")); 588 589 /* 590 * Inform any modules associated with this file. 591 */ 592 MOD_XLOCK; 593 for (mod = TAILQ_FIRST(&file->modules); mod; mod = next) { 594 next = module_getfnext(mod); 595 MOD_XUNLOCK; 596 597 /* 598 * Give the module a chance to veto the unload. 599 */ 600 if ((error = module_unload(mod, flags)) != 0) { 601 KLD_DPF(FILE, ("linker_file_unload: module %p" 602 " vetoes unload\n", mod)); 603 return (error); 604 } 605 MOD_XLOCK; 606 module_release(mod); 607 } 608 MOD_XUNLOCK; 609 610 TAILQ_FOREACH_SAFE(ml, &found_modules, link, nextml) { 611 if (ml->container == file) { 612 TAILQ_REMOVE(&found_modules, ml, link); 613 free(ml, M_LINKER); 614 } 615 } 616 617 /* 618 * Don't try to run SYSUNINITs if we are unloaded due to a 619 * link error. 620 */ 621 if (file->flags & LINKER_FILE_LINKED) { 622 linker_file_sysuninit(file); 623 linker_file_unregister_sysctls(file); 624 } 625 TAILQ_REMOVE(&linker_files, file, link); 626 627 if (file->deps) { 628 for (i = 0; i < file->ndeps; i++) 629 linker_file_unload(file->deps[i], flags); 630 free(file->deps, M_LINKER); 631 file->deps = NULL; 632 } 633 while ((cp = STAILQ_FIRST(&file->common)) != NULL) { 634 STAILQ_REMOVE_HEAD(&file->common, link); 635 free(cp, M_LINKER); 636 } 637 638 LINKER_UNLOAD(file); 639 if (file->filename) { 640 free(file->filename, M_LINKER); 641 file->filename = NULL; 642 } 643 if (file->pathname) { 644 free(file->pathname, M_LINKER); 645 file->pathname = NULL; 646 } 647 kobj_delete((kobj_t) file, M_LINKER); 648 return (0); 649} 650 651static int 652linker_file_add_dependency(linker_file_t file, linker_file_t dep) 653{ 654 linker_file_t *newdeps; 655 656 KLD_LOCK_ASSERT(); 657 newdeps = malloc((file->ndeps + 1) * sizeof(linker_file_t *), 658 M_LINKER, M_WAITOK | M_ZERO); 659 if (newdeps == NULL) 660 return (ENOMEM); 661 662 if (file->deps) { 663 bcopy(file->deps, newdeps, 664 file->ndeps * sizeof(linker_file_t *)); 665 free(file->deps, M_LINKER); 666 } 667 file->deps = newdeps; 668 file->deps[file->ndeps] = dep; 669 file->ndeps++; 670 return (0); 671} 672 673/* 674 * Locate a linker set and its contents. This is a helper function to avoid 675 * linker_if.h exposure elsewhere. Note: firstp and lastp are really void **. 676 * This function is used in this file so we can avoid having lots of (void **) 677 * casts. 678 */ 679int 680linker_file_lookup_set(linker_file_t file, const char *name, 681 void *firstp, void *lastp, int *countp) 682{ 683 int error, locked; 684 685 locked = KLD_LOCKED(); 686 if (!locked) 687 KLD_LOCK(); 688 error = LINKER_LOOKUP_SET(file, name, firstp, lastp, countp); 689 if (!locked) 690 KLD_UNLOCK(); 691 return (error); 692} 693 694/* 695 * List all functions in a file. 696 */ 697int 698linker_file_function_listall(linker_file_t lf, 699 int (*callback_func)(linker_file_t, linker_symval_t *, void *), void *arg) 700{ 701 return (LINKER_EACH_FUNCTION_NAMEVAL(lf, callback_func, arg)); 702} 703 704caddr_t 705linker_file_lookup_symbol(linker_file_t file, const char *name, int deps) 706{ 707 caddr_t sym; 708 int locked; 709 710 locked = KLD_LOCKED(); 711 if (!locked) 712 KLD_LOCK(); 713 sym = linker_file_lookup_symbol_internal(file, name, deps); 714 if (!locked) 715 KLD_UNLOCK(); 716 return (sym); 717} 718 719static caddr_t 720linker_file_lookup_symbol_internal(linker_file_t file, const char *name, 721 int deps) 722{ 723 c_linker_sym_t sym; 724 linker_symval_t symval; 725 caddr_t address; 726 size_t common_size = 0; 727 int i; 728 729 KLD_LOCK_ASSERT(); 730 KLD_DPF(SYM, ("linker_file_lookup_symbol: file=%p, name=%s, deps=%d\n", 731 file, name, deps)); 732 733 if (LINKER_LOOKUP_SYMBOL(file, name, &sym) == 0) { 734 LINKER_SYMBOL_VALUES(file, sym, &symval); 735 if (symval.value == 0) 736 /* 737 * For commons, first look them up in the 738 * dependencies and only allocate space if not found 739 * there. 740 */ 741 common_size = symval.size; 742 else { 743 KLD_DPF(SYM, ("linker_file_lookup_symbol: symbol" 744 ".value=%p\n", symval.value)); 745 return (symval.value); 746 } 747 } 748 if (deps) { 749 for (i = 0; i < file->ndeps; i++) { 750 address = linker_file_lookup_symbol_internal( 751 file->deps[i], name, 0); 752 if (address) { 753 KLD_DPF(SYM, ("linker_file_lookup_symbol:" 754 " deps value=%p\n", address)); 755 return (address); 756 } 757 } 758 } 759 if (common_size > 0) { 760 /* 761 * This is a common symbol which was not found in the 762 * dependencies. We maintain a simple common symbol table in 763 * the file object. 764 */ 765 struct common_symbol *cp; 766 767 STAILQ_FOREACH(cp, &file->common, link) { 768 if (strcmp(cp->name, name) == 0) { 769 KLD_DPF(SYM, ("linker_file_lookup_symbol:" 770 " old common value=%p\n", cp->address)); 771 return (cp->address); 772 } 773 } 774 /* 775 * Round the symbol size up to align. 776 */ 777 common_size = (common_size + sizeof(int) - 1) & -sizeof(int); 778 cp = malloc(sizeof(struct common_symbol) 779 + common_size + strlen(name) + 1, M_LINKER, 780 M_WAITOK | M_ZERO); 781 cp->address = (caddr_t)(cp + 1); 782 cp->name = cp->address + common_size; 783 strcpy(cp->name, name); 784 bzero(cp->address, common_size); 785 STAILQ_INSERT_TAIL(&file->common, cp, link); 786 787 KLD_DPF(SYM, ("linker_file_lookup_symbol: new common" 788 " value=%p\n", cp->address)); 789 return (cp->address); 790 } 791 KLD_DPF(SYM, ("linker_file_lookup_symbol: fail\n")); 792 return (0); 793} 794 795/* 796 * Both DDB and stack(9) rely on the kernel linker to provide forward and 797 * backward lookup of symbols. However, DDB and sometimes stack(9) need to 798 * do this in a lockfree manner. We provide a set of internal helper 799 * routines to perform these operations without locks, and then wrappers that 800 * optionally lock. 801 * 802 * linker_debug_lookup() is ifdef DDB as currently it's only used by DDB. 803 */ 804#ifdef DDB 805static int 806linker_debug_lookup(const char *symstr, c_linker_sym_t *sym) 807{ 808 linker_file_t lf; 809 810 TAILQ_FOREACH(lf, &linker_files, link) { 811 if (LINKER_LOOKUP_SYMBOL(lf, symstr, sym) == 0) 812 return (0); 813 } 814 return (ENOENT); 815} 816#endif 817 818static int 819linker_debug_search_symbol(caddr_t value, c_linker_sym_t *sym, long *diffp) 820{ 821 linker_file_t lf; 822 c_linker_sym_t best, es; 823 u_long diff, bestdiff, off; 824 825 best = 0; 826 off = (uintptr_t)value; 827 bestdiff = off; 828 TAILQ_FOREACH(lf, &linker_files, link) { 829 if (LINKER_SEARCH_SYMBOL(lf, value, &es, &diff) != 0) 830 continue; 831 if (es != 0 && diff < bestdiff) { 832 best = es; 833 bestdiff = diff; 834 } 835 if (bestdiff == 0) 836 break; 837 } 838 if (best) { 839 *sym = best; 840 *diffp = bestdiff; 841 return (0); 842 } else { 843 *sym = 0; 844 *diffp = off; 845 return (ENOENT); 846 } 847} 848 849static int 850linker_debug_symbol_values(c_linker_sym_t sym, linker_symval_t *symval) 851{ 852 linker_file_t lf; 853 854 TAILQ_FOREACH(lf, &linker_files, link) { 855 if (LINKER_SYMBOL_VALUES(lf, sym, symval) == 0) 856 return (0); 857 } 858 return (ENOENT); 859} 860 861static int 862linker_debug_search_symbol_name(caddr_t value, char *buf, u_int buflen, 863 long *offset) 864{ 865 linker_symval_t symval; 866 c_linker_sym_t sym; 867 int error; 868 869 *offset = 0; 870 error = linker_debug_search_symbol(value, &sym, offset); 871 if (error) 872 return (error); 873 error = linker_debug_symbol_values(sym, &symval); 874 if (error) 875 return (error); 876 strlcpy(buf, symval.name, buflen); 877 return (0); 878} 879 880#ifdef DDB 881/* 882 * DDB Helpers. DDB has to look across multiple files with their own symbol 883 * tables and string tables. 884 * 885 * Note that we do not obey list locking protocols here. We really don't need 886 * DDB to hang because somebody's got the lock held. We'll take the chance 887 * that the files list is inconsistant instead. 888 */ 889int 890linker_ddb_lookup(const char *symstr, c_linker_sym_t *sym) 891{ 892 893 return (linker_debug_lookup(symstr, sym)); 894} 895 896int 897linker_ddb_search_symbol(caddr_t value, c_linker_sym_t *sym, long *diffp) 898{ 899 900 return (linker_debug_search_symbol(value, sym, diffp)); 901} 902 903int 904linker_ddb_symbol_values(c_linker_sym_t sym, linker_symval_t *symval) 905{ 906 907 return (linker_debug_symbol_values(sym, symval)); 908} 909 910int 911linker_ddb_search_symbol_name(caddr_t value, char *buf, u_int buflen, 912 long *offset) 913{ 914 915 return (linker_debug_search_symbol_name(value, buf, buflen, offset)); 916} 917#endif 918 919/* 920 * stack(9) helper for non-debugging environemnts. Unlike DDB helpers, we do 921 * obey locking protocols, and offer a significantly less complex interface. 922 */ 923int 924linker_search_symbol_name(caddr_t value, char *buf, u_int buflen, 925 long *offset) 926{ 927 int error, locked; 928 929 locked = KLD_LOCKED(); 930 if (!locked) 931 KLD_LOCK(); 932 error = linker_debug_search_symbol_name(value, buf, buflen, offset); 933 if (!locked) 934 KLD_UNLOCK(); 935 return (error); 936} 937 938/* 939 * Syscalls. 940 */ 941int 942kern_kldload(struct thread *td, const char *file, int *fileid) 943{ 944#ifdef HWPMC_HOOKS 945 struct pmckern_map_in pkm; 946#endif 947 const char *kldname, *modname; 948 linker_file_t lf; 949 int error; 950 951 if ((error = securelevel_gt(td->td_ucred, 0)) != 0) 952 return (error); 953 954 if ((error = priv_check(td, PRIV_KLD_LOAD)) != 0) 955 return (error); 956 957 /* 958 * If file does not contain a qualified name or any dot in it 959 * (kldname.ko, or kldname.ver.ko) treat it as an interface 960 * name. 961 */ 962 if (index(file, '/') || index(file, '.')) { 963 kldname = file; 964 modname = NULL; 965 } else { 966 kldname = NULL; 967 modname = file; 968 } 969 970 KLD_LOCK(); 971 error = linker_load_module(kldname, modname, NULL, NULL, &lf); 972 if (error) 973 goto unlock; 974#ifdef HWPMC_HOOKS 975 pkm.pm_file = lf->filename; 976 pkm.pm_address = (uintptr_t) lf->address; 977 PMC_CALL_HOOK(td, PMC_FN_KLD_LOAD, (void *) &pkm); 978#endif 979 lf->userrefs++; 980 if (fileid != NULL) 981 *fileid = lf->id; 982unlock: 983 KLD_UNLOCK(); 984 return (error); 985} 986 987int 988kldload(struct thread *td, struct kldload_args *uap) 989{ 990 char *pathname = NULL; 991 int error, fileid; 992 993 td->td_retval[0] = -1; 994 995 pathname = malloc(MAXPATHLEN, M_TEMP, M_WAITOK); 996 error = copyinstr(uap->file, pathname, MAXPATHLEN, NULL); 997 if (error == 0) { 998 error = kern_kldload(td, pathname, &fileid); 999 if (error == 0) 1000 td->td_retval[0] = fileid; 1001 } 1002 free(pathname, M_TEMP); 1003 return (error); 1004} 1005 1006int 1007kern_kldunload(struct thread *td, int fileid, int flags) 1008{ 1009#ifdef HWPMC_HOOKS 1010 struct pmckern_map_out pkm; 1011#endif 1012 linker_file_t lf; 1013 int error = 0; 1014 1015 if ((error = securelevel_gt(td->td_ucred, 0)) != 0) 1016 return (error); 1017 1018 if ((error = priv_check(td, PRIV_KLD_UNLOAD)) != 0) 1019 return (error); 1020 1021 KLD_LOCK(); 1022 lf = linker_find_file_by_id(fileid); 1023 if (lf) { 1024 KLD_DPF(FILE, ("kldunload: lf->userrefs=%d\n", lf->userrefs)); 1025 1026 /* Check if there are DTrace probes enabled on this file. */ 1027 if (lf->nenabled > 0) { 1028 printf("kldunload: attempt to unload file that has" 1029 " DTrace probes enabled\n"); 1030 error = EBUSY; 1031 } else if (lf->userrefs == 0) { 1032 /* 1033 * XXX: maybe LINKER_UNLOAD_FORCE should override ? 1034 */ 1035 printf("kldunload: attempt to unload file that was" 1036 " loaded by the kernel\n"); 1037 error = EBUSY; 1038 } else { 1039#ifdef HWPMC_HOOKS 1040 /* Save data needed by hwpmc(4) before unloading. */ 1041 pkm.pm_address = (uintptr_t) lf->address; 1042 pkm.pm_size = lf->size; 1043#endif 1044 lf->userrefs--; 1045 error = linker_file_unload(lf, flags); 1046 if (error) 1047 lf->userrefs++; 1048 } 1049 } else 1050 error = ENOENT; 1051 1052#ifdef HWPMC_HOOKS 1053 if (error == 0) 1054 PMC_CALL_HOOK(td, PMC_FN_KLD_UNLOAD, (void *) &pkm); 1055#endif 1056 KLD_UNLOCK(); 1057 return (error); 1058} 1059 1060int 1061kldunload(struct thread *td, struct kldunload_args *uap) 1062{ 1063 1064 return (kern_kldunload(td, uap->fileid, LINKER_UNLOAD_NORMAL)); 1065} 1066 1067int 1068kldunloadf(struct thread *td, struct kldunloadf_args *uap) 1069{ 1070 1071 if (uap->flags != LINKER_UNLOAD_NORMAL && 1072 uap->flags != LINKER_UNLOAD_FORCE) 1073 return (EINVAL); 1074 return (kern_kldunload(td, uap->fileid, uap->flags)); 1075} 1076 1077int 1078kldfind(struct thread *td, struct kldfind_args *uap) 1079{ 1080 char *pathname; 1081 const char *filename; 1082 linker_file_t lf; 1083 int error; 1084 1085#ifdef MAC 1086 error = mac_kld_check_stat(td->td_ucred); 1087 if (error) 1088 return (error); 1089#endif 1090 1091 td->td_retval[0] = -1; 1092 1093 pathname = malloc(MAXPATHLEN, M_TEMP, M_WAITOK); 1094 if ((error = copyinstr(uap->file, pathname, MAXPATHLEN, NULL)) != 0) 1095 goto out; 1096 1097 filename = linker_basename(pathname); 1098 KLD_LOCK(); 1099 lf = linker_find_file_by_name(filename); 1100 if (lf) 1101 td->td_retval[0] = lf->id; 1102 else 1103 error = ENOENT; 1104 KLD_UNLOCK(); 1105out: 1106 free(pathname, M_TEMP); 1107 return (error); 1108} 1109 1110int 1111kldnext(struct thread *td, struct kldnext_args *uap) 1112{ 1113 linker_file_t lf; 1114 int error = 0; 1115 1116#ifdef MAC 1117 error = mac_kld_check_stat(td->td_ucred); 1118 if (error) 1119 return (error); 1120#endif 1121 1122 KLD_LOCK(); 1123 if (uap->fileid == 0) 1124 lf = TAILQ_FIRST(&linker_files); 1125 else { 1126 lf = linker_find_file_by_id(uap->fileid); 1127 if (lf == NULL) { 1128 error = ENOENT; 1129 goto out; 1130 } 1131 lf = TAILQ_NEXT(lf, link); 1132 } 1133 1134 /* Skip partially loaded files. */ 1135 while (lf != NULL && !(lf->flags & LINKER_FILE_LINKED)) 1136 lf = TAILQ_NEXT(lf, link); 1137 1138 if (lf) 1139 td->td_retval[0] = lf->id; 1140 else 1141 td->td_retval[0] = 0; 1142out: 1143 KLD_UNLOCK(); 1144 return (error); 1145} 1146 1147int 1148kldstat(struct thread *td, struct kldstat_args *uap) 1149{ 1150 struct kld_file_stat stat; 1151 linker_file_t lf; 1152 int error, namelen, version, version_num; 1153 1154 /* 1155 * Check the version of the user's structure. 1156 */ 1157 if ((error = copyin(&uap->stat->version, &version, sizeof(version))) != 0) 1158 return (error); 1159 if (version == sizeof(struct kld_file_stat_1)) 1160 version_num = 1; 1161 else if (version == sizeof(struct kld_file_stat)) 1162 version_num = 2; 1163 else 1164 return (EINVAL); 1165 1166#ifdef MAC 1167 error = mac_kld_check_stat(td->td_ucred); 1168 if (error) 1169 return (error); 1170#endif 1171 1172 KLD_LOCK(); 1173 lf = linker_find_file_by_id(uap->fileid); 1174 if (lf == NULL) { 1175 KLD_UNLOCK(); 1176 return (ENOENT); 1177 } 1178 1179 /* Version 1 fields: */ 1180 namelen = strlen(lf->filename) + 1; 1181 if (namelen > MAXPATHLEN) 1182 namelen = MAXPATHLEN; 1183 bcopy(lf->filename, &stat.name[0], namelen); 1184 stat.refs = lf->refs; 1185 stat.id = lf->id; 1186 stat.address = lf->address; 1187 stat.size = lf->size; 1188 if (version_num > 1) { 1189 /* Version 2 fields: */ 1190 namelen = strlen(lf->pathname) + 1; 1191 if (namelen > MAXPATHLEN) 1192 namelen = MAXPATHLEN; 1193 bcopy(lf->pathname, &stat.pathname[0], namelen); 1194 } 1195 KLD_UNLOCK(); 1196 1197 td->td_retval[0] = 0; 1198 1199 return (copyout(&stat, uap->stat, version)); 1200} 1201 1202int 1203kldfirstmod(struct thread *td, struct kldfirstmod_args *uap) 1204{ 1205 linker_file_t lf; 1206 module_t mp; 1207 int error = 0; 1208 1209#ifdef MAC 1210 error = mac_kld_check_stat(td->td_ucred); 1211 if (error) 1212 return (error); 1213#endif 1214 1215 KLD_LOCK(); 1216 lf = linker_find_file_by_id(uap->fileid); 1217 if (lf) { 1218 MOD_SLOCK; 1219 mp = TAILQ_FIRST(&lf->modules); 1220 if (mp != NULL) 1221 td->td_retval[0] = module_getid(mp); 1222 else 1223 td->td_retval[0] = 0; 1224 MOD_SUNLOCK; 1225 } else 1226 error = ENOENT; 1227 KLD_UNLOCK(); 1228 return (error); 1229} 1230 1231int 1232kldsym(struct thread *td, struct kldsym_args *uap) 1233{ 1234 char *symstr = NULL; 1235 c_linker_sym_t sym; 1236 linker_symval_t symval; 1237 linker_file_t lf; 1238 struct kld_sym_lookup lookup; 1239 int error = 0; 1240 1241#ifdef MAC 1242 error = mac_kld_check_stat(td->td_ucred); 1243 if (error) 1244 return (error); 1245#endif 1246 1247 if ((error = copyin(uap->data, &lookup, sizeof(lookup))) != 0) 1248 return (error); 1249 if (lookup.version != sizeof(lookup) || 1250 uap->cmd != KLDSYM_LOOKUP) 1251 return (EINVAL); 1252 symstr = malloc(MAXPATHLEN, M_TEMP, M_WAITOK); 1253 if ((error = copyinstr(lookup.symname, symstr, MAXPATHLEN, NULL)) != 0) 1254 goto out; 1255 KLD_LOCK(); 1256 if (uap->fileid != 0) { 1257 lf = linker_find_file_by_id(uap->fileid); 1258 if (lf == NULL) 1259 error = ENOENT; 1260 else if (LINKER_LOOKUP_SYMBOL(lf, symstr, &sym) == 0 && 1261 LINKER_SYMBOL_VALUES(lf, sym, &symval) == 0) { 1262 lookup.symvalue = (uintptr_t) symval.value; 1263 lookup.symsize = symval.size; 1264 error = copyout(&lookup, uap->data, sizeof(lookup)); 1265 } else 1266 error = ENOENT; 1267 } else { 1268 TAILQ_FOREACH(lf, &linker_files, link) { 1269 if (LINKER_LOOKUP_SYMBOL(lf, symstr, &sym) == 0 && 1270 LINKER_SYMBOL_VALUES(lf, sym, &symval) == 0) { 1271 lookup.symvalue = (uintptr_t)symval.value; 1272 lookup.symsize = symval.size; 1273 error = copyout(&lookup, uap->data, 1274 sizeof(lookup)); 1275 break; 1276 } 1277 } 1278 if (lf == NULL) 1279 error = ENOENT; 1280 } 1281 KLD_UNLOCK(); 1282out: 1283 free(symstr, M_TEMP); 1284 return (error); 1285} 1286 1287/* 1288 * Preloaded module support 1289 */ 1290 1291static modlist_t 1292modlist_lookup(const char *name, int ver) 1293{ 1294 modlist_t mod; 1295 1296 TAILQ_FOREACH(mod, &found_modules, link) { 1297 if (strcmp(mod->name, name) == 0 && 1298 (ver == 0 || mod->version == ver)) 1299 return (mod); 1300 } 1301 return (NULL); 1302} 1303 1304static modlist_t 1305modlist_lookup2(const char *name, struct mod_depend *verinfo) 1306{ 1307 modlist_t mod, bestmod; 1308 int ver; 1309 1310 if (verinfo == NULL) 1311 return (modlist_lookup(name, 0)); 1312 bestmod = NULL; 1313 TAILQ_FOREACH(mod, &found_modules, link) { 1314 if (strcmp(mod->name, name) != 0) 1315 continue; 1316 ver = mod->version; 1317 if (ver == verinfo->md_ver_preferred) 1318 return (mod); 1319 if (ver >= verinfo->md_ver_minimum && 1320 ver <= verinfo->md_ver_maximum && 1321 (bestmod == NULL || ver > bestmod->version)) 1322 bestmod = mod; 1323 } 1324 return (bestmod); 1325} 1326 1327static modlist_t 1328modlist_newmodule(const char *modname, int version, linker_file_t container) 1329{ 1330 modlist_t mod; 1331 1332 mod = malloc(sizeof(struct modlist), M_LINKER, M_NOWAIT | M_ZERO); 1333 if (mod == NULL) 1334 panic("no memory for module list"); 1335 mod->container = container; 1336 mod->name = modname; 1337 mod->version = version; 1338 TAILQ_INSERT_TAIL(&found_modules, mod, link); 1339 return (mod); 1340} 1341 1342static void 1343linker_addmodules(linker_file_t lf, struct mod_metadata **start, 1344 struct mod_metadata **stop, int preload) 1345{ 1346 struct mod_metadata *mp, **mdp; 1347 const char *modname; 1348 int ver; 1349 1350 for (mdp = start; mdp < stop; mdp++) { 1351 mp = *mdp; 1352 if (mp->md_type != MDT_VERSION) 1353 continue; 1354 modname = mp->md_cval; 1355 ver = ((struct mod_version *)mp->md_data)->mv_version; 1356 if (modlist_lookup(modname, ver) != NULL) { 1357 printf("module %s already present!\n", modname); 1358 /* XXX what can we do? this is a build error. :-( */ 1359 continue; 1360 } 1361 modlist_newmodule(modname, ver, lf); 1362 } 1363} 1364 1365static void 1366linker_preload(void *arg) 1367{ 1368 caddr_t modptr; 1369 const char *modname, *nmodname; 1370 char *modtype; 1371 linker_file_t lf, nlf; 1372 linker_class_t lc; 1373 int error; 1374 linker_file_list_t loaded_files; 1375 linker_file_list_t depended_files; 1376 struct mod_metadata *mp, *nmp; 1377 struct mod_metadata **start, **stop, **mdp, **nmdp; 1378 struct mod_depend *verinfo; 1379 int nver; 1380 int resolves; 1381 modlist_t mod; 1382 struct sysinit **si_start, **si_stop; 1383 1384 TAILQ_INIT(&loaded_files); 1385 TAILQ_INIT(&depended_files); 1386 TAILQ_INIT(&found_modules); 1387 error = 0; 1388 1389 modptr = NULL; 1390 while ((modptr = preload_search_next_name(modptr)) != NULL) { 1391 modname = (char *)preload_search_info(modptr, MODINFO_NAME); 1392 modtype = (char *)preload_search_info(modptr, MODINFO_TYPE); 1393 if (modname == NULL) { 1394 printf("Preloaded module at %p does not have a" 1395 " name!\n", modptr); 1396 continue; 1397 } 1398 if (modtype == NULL) { 1399 printf("Preloaded module at %p does not have a type!\n", 1400 modptr); 1401 continue; 1402 } 1403 if (bootverbose) 1404 printf("Preloaded %s \"%s\" at %p.\n", modtype, modname, 1405 modptr); 1406 lf = NULL; 1407 TAILQ_FOREACH(lc, &classes, link) { 1408 error = LINKER_LINK_PRELOAD(lc, modname, &lf); 1409 if (!error) 1410 break; 1411 lf = NULL; 1412 } 1413 if (lf) 1414 TAILQ_INSERT_TAIL(&loaded_files, lf, loaded); 1415 } 1416 1417 /* 1418 * First get a list of stuff in the kernel. 1419 */ 1420 if (linker_file_lookup_set(linker_kernel_file, MDT_SETNAME, &start, 1421 &stop, NULL) == 0) 1422 linker_addmodules(linker_kernel_file, start, stop, 1); 1423 1424 /* 1425 * This is a once-off kinky bubble sort to resolve relocation 1426 * dependency requirements. 1427 */ 1428restart: 1429 TAILQ_FOREACH(lf, &loaded_files, loaded) { 1430 error = linker_file_lookup_set(lf, MDT_SETNAME, &start, 1431 &stop, NULL); 1432 /* 1433 * First, look to see if we would successfully link with this 1434 * stuff. 1435 */ 1436 resolves = 1; /* unless we know otherwise */ 1437 if (!error) { 1438 for (mdp = start; mdp < stop; mdp++) { 1439 mp = *mdp; 1440 if (mp->md_type != MDT_DEPEND) 1441 continue; 1442 modname = mp->md_cval; 1443 verinfo = mp->md_data; 1444 for (nmdp = start; nmdp < stop; nmdp++) { 1445 nmp = *nmdp; 1446 if (nmp->md_type != MDT_VERSION) 1447 continue; 1448 nmodname = nmp->md_cval; 1449 if (strcmp(modname, nmodname) == 0) 1450 break; 1451 } 1452 if (nmdp < stop) /* it's a self reference */ 1453 continue; 1454 1455 /* 1456 * ok, the module isn't here yet, we 1457 * are not finished 1458 */ 1459 if (modlist_lookup2(modname, verinfo) == NULL) 1460 resolves = 0; 1461 } 1462 } 1463 /* 1464 * OK, if we found our modules, we can link. So, "provide" 1465 * the modules inside and add it to the end of the link order 1466 * list. 1467 */ 1468 if (resolves) { 1469 if (!error) { 1470 for (mdp = start; mdp < stop; mdp++) { 1471 mp = *mdp; 1472 if (mp->md_type != MDT_VERSION) 1473 continue; 1474 modname = mp->md_cval; 1475 nver = ((struct mod_version *) 1476 mp->md_data)->mv_version; 1477 if (modlist_lookup(modname, 1478 nver) != NULL) { 1479 printf("module %s already" 1480 " present!\n", modname); 1481 TAILQ_REMOVE(&loaded_files, 1482 lf, loaded); 1483 linker_file_unload(lf, 1484 LINKER_UNLOAD_FORCE); 1485 /* we changed tailq next ptr */ 1486 goto restart; 1487 } 1488 modlist_newmodule(modname, nver, lf); 1489 } 1490 } 1491 TAILQ_REMOVE(&loaded_files, lf, loaded); 1492 TAILQ_INSERT_TAIL(&depended_files, lf, loaded); 1493 /* 1494 * Since we provided modules, we need to restart the 1495 * sort so that the previous files that depend on us 1496 * have a chance. Also, we've busted the tailq next 1497 * pointer with the REMOVE. 1498 */ 1499 goto restart; 1500 } 1501 } 1502 1503 /* 1504 * At this point, we check to see what could not be resolved.. 1505 */ 1506 while ((lf = TAILQ_FIRST(&loaded_files)) != NULL) { 1507 TAILQ_REMOVE(&loaded_files, lf, loaded); 1508 printf("KLD file %s is missing dependencies\n", lf->filename); 1509 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 1510 } 1511 1512 /* 1513 * We made it. Finish off the linking in the order we determined. 1514 */ 1515 TAILQ_FOREACH_SAFE(lf, &depended_files, loaded, nlf) { 1516 if (linker_kernel_file) { 1517 linker_kernel_file->refs++; 1518 error = linker_file_add_dependency(lf, 1519 linker_kernel_file); 1520 if (error) 1521 panic("cannot add dependency"); 1522 } 1523 lf->userrefs++; /* so we can (try to) kldunload it */ 1524 error = linker_file_lookup_set(lf, MDT_SETNAME, &start, 1525 &stop, NULL); 1526 if (!error) { 1527 for (mdp = start; mdp < stop; mdp++) { 1528 mp = *mdp; 1529 if (mp->md_type != MDT_DEPEND) 1530 continue; 1531 modname = mp->md_cval; 1532 verinfo = mp->md_data; 1533 mod = modlist_lookup2(modname, verinfo); 1534 /* Don't count self-dependencies */ 1535 if (lf == mod->container) 1536 continue; 1537 mod->container->refs++; 1538 error = linker_file_add_dependency(lf, 1539 mod->container); 1540 if (error) 1541 panic("cannot add dependency"); 1542 } 1543 } 1544 /* 1545 * Now do relocation etc using the symbol search paths 1546 * established by the dependencies 1547 */ 1548 error = LINKER_LINK_PRELOAD_FINISH(lf); 1549 if (error) { 1550 TAILQ_REMOVE(&depended_files, lf, loaded); 1551 printf("KLD file %s - could not finalize loading\n", 1552 lf->filename); 1553 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 1554 continue; 1555 } 1556 linker_file_register_modules(lf); 1557 if (linker_file_lookup_set(lf, "sysinit_set", &si_start, 1558 &si_stop, NULL) == 0) 1559 sysinit_add(si_start, si_stop); 1560 linker_file_register_sysctls(lf); 1561 lf->flags |= LINKER_FILE_LINKED; 1562 } 1563 /* woohoo! we made it! */ 1564} 1565 1566SYSINIT(preload, SI_SUB_KLD, SI_ORDER_MIDDLE, linker_preload, 0); 1567 1568/* 1569 * Search for a not-loaded module by name. 1570 * 1571 * Modules may be found in the following locations: 1572 * 1573 * - preloaded (result is just the module name) - on disk (result is full path 1574 * to module) 1575 * 1576 * If the module name is qualified in any way (contains path, etc.) the we 1577 * simply return a copy of it. 1578 * 1579 * The search path can be manipulated via sysctl. Note that we use the ';' 1580 * character as a separator to be consistent with the bootloader. 1581 */ 1582 1583static char linker_hintfile[] = "linker.hints"; 1584static char linker_path[MAXPATHLEN] = "/boot/kernel;/boot/modules"; 1585 1586SYSCTL_STRING(_kern, OID_AUTO, module_path, CTLFLAG_RW, linker_path, 1587 sizeof(linker_path), "module load search path"); 1588 1589TUNABLE_STR("module_path", linker_path, sizeof(linker_path)); 1590 1591static char *linker_ext_list[] = { 1592 "", 1593 ".ko", 1594 NULL 1595}; 1596 1597/* 1598 * Check if file actually exists either with or without extension listed in 1599 * the linker_ext_list. (probably should be generic for the rest of the 1600 * kernel) 1601 */ 1602static char * 1603linker_lookup_file(const char *path, int pathlen, const char *name, 1604 int namelen, struct vattr *vap) 1605{ 1606 struct nameidata nd; 1607 struct thread *td = curthread; /* XXX */ 1608 char *result, **cpp, *sep; 1609 int error, len, extlen, reclen, flags, vfslocked; 1610 enum vtype type; 1611 1612 extlen = 0; 1613 for (cpp = linker_ext_list; *cpp; cpp++) { 1614 len = strlen(*cpp); 1615 if (len > extlen) 1616 extlen = len; 1617 } 1618 extlen++; /* trailing '\0' */ 1619 sep = (path[pathlen - 1] != '/') ? "/" : ""; 1620 1621 reclen = pathlen + strlen(sep) + namelen + extlen + 1; 1622 result = malloc(reclen, M_LINKER, M_WAITOK); 1623 for (cpp = linker_ext_list; *cpp; cpp++) { 1624 snprintf(result, reclen, "%.*s%s%.*s%s", pathlen, path, sep, 1625 namelen, name, *cpp); 1626 /* 1627 * Attempt to open the file, and return the path if 1628 * we succeed and it's a regular file. 1629 */ 1630 NDINIT(&nd, LOOKUP, FOLLOW | MPSAFE, UIO_SYSSPACE, result, td); 1631 flags = FREAD; 1632 error = vn_open(&nd, &flags, 0, NULL); 1633 if (error == 0) { 1634 vfslocked = NDHASGIANT(&nd); 1635 NDFREE(&nd, NDF_ONLY_PNBUF); 1636 type = nd.ni_vp->v_type; 1637 if (vap) 1638 VOP_GETATTR(nd.ni_vp, vap, td->td_ucred, td); 1639 VOP_UNLOCK(nd.ni_vp, 0); 1640 vn_close(nd.ni_vp, FREAD, td->td_ucred, td); 1641 VFS_UNLOCK_GIANT(vfslocked); 1642 if (type == VREG) 1643 return (result); 1644 } 1645 } 1646 free(result, M_LINKER); 1647 return (NULL); 1648} 1649 1650#define INT_ALIGN(base, ptr) ptr = \ 1651 (base) + (((ptr) - (base) + sizeof(int) - 1) & ~(sizeof(int) - 1)) 1652 1653/* 1654 * Lookup KLD which contains requested module in the "linker.hints" file. If 1655 * version specification is available, then try to find the best KLD. 1656 * Otherwise just find the latest one. 1657 */ 1658static char * 1659linker_hints_lookup(const char *path, int pathlen, const char *modname, 1660 int modnamelen, struct mod_depend *verinfo) 1661{ 1662 struct thread *td = curthread; /* XXX */ 1663 struct ucred *cred = td ? td->td_ucred : NULL; 1664 struct nameidata nd; 1665 struct vattr vattr, mattr; 1666 u_char *hints = NULL; 1667 u_char *cp, *recptr, *bufend, *result, *best, *pathbuf, *sep; 1668 int error, ival, bestver, *intp, reclen, found, flags, clen, blen; 1669 int vfslocked = 0; 1670 1671 result = NULL; 1672 bestver = found = 0; 1673 1674 sep = (path[pathlen - 1] != '/') ? "/" : ""; 1675 reclen = imax(modnamelen, strlen(linker_hintfile)) + pathlen + 1676 strlen(sep) + 1; 1677 pathbuf = malloc(reclen, M_LINKER, M_WAITOK); 1678 snprintf(pathbuf, reclen, "%.*s%s%s", pathlen, path, sep, 1679 linker_hintfile); 1680 1681 NDINIT(&nd, LOOKUP, NOFOLLOW | MPSAFE, UIO_SYSSPACE, pathbuf, td); 1682 flags = FREAD; 1683 error = vn_open(&nd, &flags, 0, NULL); 1684 if (error) 1685 goto bad; 1686 vfslocked = NDHASGIANT(&nd); 1687 NDFREE(&nd, NDF_ONLY_PNBUF); 1688 if (nd.ni_vp->v_type != VREG) 1689 goto bad; 1690 best = cp = NULL; 1691 error = VOP_GETATTR(nd.ni_vp, &vattr, cred, td); 1692 if (error) 1693 goto bad; 1694 /* 1695 * XXX: we need to limit this number to some reasonable value 1696 */ 1697 if (vattr.va_size > 100 * 1024) { 1698 printf("hints file too large %ld\n", (long)vattr.va_size); 1699 goto bad; 1700 } 1701 hints = malloc(vattr.va_size, M_TEMP, M_WAITOK); 1702 if (hints == NULL) 1703 goto bad; 1704 error = vn_rdwr(UIO_READ, nd.ni_vp, (caddr_t)hints, vattr.va_size, 0, 1705 UIO_SYSSPACE, IO_NODELOCKED, cred, NOCRED, &reclen, td); 1706 if (error) 1707 goto bad; 1708 VOP_UNLOCK(nd.ni_vp, 0); 1709 vn_close(nd.ni_vp, FREAD, cred, td); 1710 VFS_UNLOCK_GIANT(vfslocked); 1711 nd.ni_vp = NULL; 1712 if (reclen != 0) { 1713 printf("can't read %d\n", reclen); 1714 goto bad; 1715 } 1716 intp = (int *)hints; 1717 ival = *intp++; 1718 if (ival != LINKER_HINTS_VERSION) { 1719 printf("hints file version mismatch %d\n", ival); 1720 goto bad; 1721 } 1722 bufend = hints + vattr.va_size; 1723 recptr = (u_char *)intp; 1724 clen = blen = 0; 1725 while (recptr < bufend && !found) { 1726 intp = (int *)recptr; 1727 reclen = *intp++; 1728 ival = *intp++; 1729 cp = (char *)intp; 1730 switch (ival) { 1731 case MDT_VERSION: 1732 clen = *cp++; 1733 if (clen != modnamelen || bcmp(cp, modname, clen) != 0) 1734 break; 1735 cp += clen; 1736 INT_ALIGN(hints, cp); 1737 ival = *(int *)cp; 1738 cp += sizeof(int); 1739 clen = *cp++; 1740 if (verinfo == NULL || 1741 ival == verinfo->md_ver_preferred) { 1742 found = 1; 1743 break; 1744 } 1745 if (ival >= verinfo->md_ver_minimum && 1746 ival <= verinfo->md_ver_maximum && 1747 ival > bestver) { 1748 bestver = ival; 1749 best = cp; 1750 blen = clen; 1751 } 1752 break; 1753 default: 1754 break; 1755 } 1756 recptr += reclen + sizeof(int); 1757 } 1758 /* 1759 * Finally check if KLD is in the place 1760 */ 1761 if (found) 1762 result = linker_lookup_file(path, pathlen, cp, clen, &mattr); 1763 else if (best) 1764 result = linker_lookup_file(path, pathlen, best, blen, &mattr); 1765 1766 /* 1767 * KLD is newer than hints file. What we should do now? 1768 */ 1769 if (result && timespeccmp(&mattr.va_mtime, &vattr.va_mtime, >)) 1770 printf("warning: KLD '%s' is newer than the linker.hints" 1771 " file\n", result); 1772bad: 1773 free(pathbuf, M_LINKER); 1774 if (hints) 1775 free(hints, M_TEMP); 1776 if (nd.ni_vp != NULL) { 1777 VOP_UNLOCK(nd.ni_vp, 0); 1778 vn_close(nd.ni_vp, FREAD, cred, td); 1779 VFS_UNLOCK_GIANT(vfslocked); 1780 } 1781 /* 1782 * If nothing found or hints is absent - fallback to the old 1783 * way by using "kldname[.ko]" as module name. 1784 */ 1785 if (!found && !bestver && result == NULL) 1786 result = linker_lookup_file(path, pathlen, modname, 1787 modnamelen, NULL); 1788 return (result); 1789} 1790 1791/* 1792 * Lookup KLD which contains requested module in the all directories. 1793 */ 1794static char * 1795linker_search_module(const char *modname, int modnamelen, 1796 struct mod_depend *verinfo) 1797{ 1798 char *cp, *ep, *result; 1799 1800 /* 1801 * traverse the linker path 1802 */ 1803 for (cp = linker_path; *cp; cp = ep + 1) { 1804 /* find the end of this component */ 1805 for (ep = cp; (*ep != 0) && (*ep != ';'); ep++); 1806 result = linker_hints_lookup(cp, ep - cp, modname, 1807 modnamelen, verinfo); 1808 if (result != NULL) 1809 return (result); 1810 if (*ep == 0) 1811 break; 1812 } 1813 return (NULL); 1814} 1815 1816/* 1817 * Search for module in all directories listed in the linker_path. 1818 */ 1819static char * 1820linker_search_kld(const char *name) 1821{ 1822 char *cp, *ep, *result; 1823 int len; 1824 1825 /* qualified at all? */ 1826 if (index(name, '/')) 1827 return (linker_strdup(name)); 1828 1829 /* traverse the linker path */ 1830 len = strlen(name); 1831 for (ep = linker_path; *ep; ep++) { 1832 cp = ep; 1833 /* find the end of this component */ 1834 for (; *ep != 0 && *ep != ';'; ep++); 1835 result = linker_lookup_file(cp, ep - cp, name, len, NULL); 1836 if (result != NULL) 1837 return (result); 1838 } 1839 return (NULL); 1840} 1841 1842static const char * 1843linker_basename(const char *path) 1844{ 1845 const char *filename; 1846 1847 filename = rindex(path, '/'); 1848 if (filename == NULL) 1849 return path; 1850 if (filename[1]) 1851 filename++; 1852 return (filename); 1853} 1854 1855#ifdef HWPMC_HOOKS 1856 1857struct hwpmc_context { 1858 int nobjects; 1859 int nmappings; 1860 struct pmckern_map_in *kobase; 1861}; 1862 1863static int 1864linker_hwpmc_list_object(linker_file_t lf, void *arg) 1865{ 1866 struct hwpmc_context *hc; 1867 1868 hc = arg; 1869 1870 /* If we run out of mappings, fail. */ 1871 if (hc->nobjects >= hc->nmappings) 1872 return (1); 1873 1874 /* Save the info for this linker file. */ 1875 hc->kobase[hc->nobjects].pm_file = lf->filename; 1876 hc->kobase[hc->nobjects].pm_address = (uintptr_t)lf->address; 1877 hc->nobjects++; 1878 return (0); 1879} 1880 1881/* 1882 * Inform hwpmc about the set of kernel modules currently loaded. 1883 */ 1884void * 1885linker_hwpmc_list_objects(void) 1886{ 1887 struct hwpmc_context hc; 1888 1889 hc.nmappings = 15; /* a reasonable default */ 1890 1891 retry: 1892 /* allocate nmappings+1 entries */ 1893 MALLOC(hc.kobase, struct pmckern_map_in *, 1894 (hc.nmappings + 1) * sizeof(struct pmckern_map_in), M_LINKER, 1895 M_WAITOK | M_ZERO); 1896 1897 hc.nobjects = 0; 1898 if (linker_file_foreach(linker_hwpmc_list_object, &hc) != 0) { 1899 hc.nmappings = hc.nobjects; 1900 FREE(hc.kobase, M_LINKER); 1901 goto retry; 1902 } 1903 1904 KASSERT(hc.nobjects > 0, ("linker_hpwmc_list_objects: no kernel " 1905 "objects?")); 1906 1907 /* The last entry of the malloced area comprises of all zeros. */ 1908 KASSERT(hc.kobase[hc.nobjects].pm_file == NULL, 1909 ("linker_hwpmc_list_objects: last object not NULL")); 1910 1911 return ((void *)hc.kobase); 1912} 1913#endif 1914 1915/* 1916 * Find a file which contains given module and load it, if "parent" is not 1917 * NULL, register a reference to it. 1918 */ 1919static int 1920linker_load_module(const char *kldname, const char *modname, 1921 struct linker_file *parent, struct mod_depend *verinfo, 1922 struct linker_file **lfpp) 1923{ 1924 linker_file_t lfdep; 1925 const char *filename; 1926 char *pathname; 1927 int error; 1928 1929 KLD_LOCK_ASSERT(); 1930 if (modname == NULL) { 1931 /* 1932 * We have to load KLD 1933 */ 1934 KASSERT(verinfo == NULL, ("linker_load_module: verinfo" 1935 " is not NULL")); 1936 pathname = linker_search_kld(kldname); 1937 } else { 1938 if (modlist_lookup2(modname, verinfo) != NULL) 1939 return (EEXIST); 1940 if (kldname != NULL) 1941 pathname = linker_strdup(kldname); 1942 else if (rootvnode == NULL) 1943 pathname = NULL; 1944 else 1945 /* 1946 * Need to find a KLD with required module 1947 */ 1948 pathname = linker_search_module(modname, 1949 strlen(modname), verinfo); 1950 } 1951 if (pathname == NULL) 1952 return (ENOENT); 1953 1954 /* 1955 * Can't load more than one file with the same basename XXX: 1956 * Actually it should be possible to have multiple KLDs with 1957 * the same basename but different path because they can 1958 * provide different versions of the same modules. 1959 */ 1960 filename = linker_basename(pathname); 1961 if (linker_find_file_by_name(filename)) 1962 error = EEXIST; 1963 else do { 1964 error = linker_load_file(pathname, &lfdep); 1965 if (error) 1966 break; 1967 if (modname && verinfo && 1968 modlist_lookup2(modname, verinfo) == NULL) { 1969 linker_file_unload(lfdep, LINKER_UNLOAD_FORCE); 1970 error = ENOENT; 1971 break; 1972 } 1973 if (parent) { 1974 error = linker_file_add_dependency(parent, lfdep); 1975 if (error) 1976 break; 1977 } 1978 if (lfpp) 1979 *lfpp = lfdep; 1980 } while (0); 1981 free(pathname, M_LINKER); 1982 return (error); 1983} 1984 1985/* 1986 * This routine is responsible for finding dependencies of userland initiated 1987 * kldload(2)'s of files. 1988 */ 1989int 1990linker_load_dependencies(linker_file_t lf) 1991{ 1992 linker_file_t lfdep; 1993 struct mod_metadata **start, **stop, **mdp, **nmdp; 1994 struct mod_metadata *mp, *nmp; 1995 struct mod_depend *verinfo; 1996 modlist_t mod; 1997 const char *modname, *nmodname; 1998 int ver, error = 0, count; 1999 2000 /* 2001 * All files are dependant on /kernel. 2002 */ 2003 KLD_LOCK_ASSERT(); 2004 if (linker_kernel_file) { 2005 linker_kernel_file->refs++; 2006 error = linker_file_add_dependency(lf, linker_kernel_file); 2007 if (error) 2008 return (error); 2009 } 2010 if (linker_file_lookup_set(lf, MDT_SETNAME, &start, &stop, 2011 &count) != 0) 2012 return (0); 2013 for (mdp = start; mdp < stop; mdp++) { 2014 mp = *mdp; 2015 if (mp->md_type != MDT_VERSION) 2016 continue; 2017 modname = mp->md_cval; 2018 ver = ((struct mod_version *)mp->md_data)->mv_version; 2019 mod = modlist_lookup(modname, ver); 2020 if (mod != NULL) { 2021 printf("interface %s.%d already present in the KLD" 2022 " '%s'!\n", modname, ver, 2023 mod->container->filename); 2024 return (EEXIST); 2025 } 2026 } 2027 2028 for (mdp = start; mdp < stop; mdp++) { 2029 mp = *mdp; 2030 if (mp->md_type != MDT_DEPEND) 2031 continue; 2032 modname = mp->md_cval; 2033 verinfo = mp->md_data; 2034 nmodname = NULL; 2035 for (nmdp = start; nmdp < stop; nmdp++) { 2036 nmp = *nmdp; 2037 if (nmp->md_type != MDT_VERSION) 2038 continue; 2039 nmodname = nmp->md_cval; 2040 if (strcmp(modname, nmodname) == 0) 2041 break; 2042 } 2043 if (nmdp < stop)/* early exit, it's a self reference */ 2044 continue; 2045 mod = modlist_lookup2(modname, verinfo); 2046 if (mod) { /* woohoo, it's loaded already */ 2047 lfdep = mod->container; 2048 lfdep->refs++; 2049 error = linker_file_add_dependency(lf, lfdep); 2050 if (error) 2051 break; 2052 continue; 2053 } 2054 error = linker_load_module(NULL, modname, lf, verinfo, NULL); 2055 if (error) { 2056 printf("KLD %s: depends on %s - not available\n", 2057 lf->filename, modname); 2058 break; 2059 } 2060 } 2061 2062 if (error) 2063 return (error); 2064 linker_addmodules(lf, start, stop, 0); 2065 return (error); 2066} 2067 2068static int 2069sysctl_kern_function_list_iterate(const char *name, void *opaque) 2070{ 2071 struct sysctl_req *req; 2072 2073 req = opaque; 2074 return (SYSCTL_OUT(req, name, strlen(name) + 1)); 2075} 2076 2077/* 2078 * Export a nul-separated, double-nul-terminated list of all function names 2079 * in the kernel. 2080 */ 2081static int 2082sysctl_kern_function_list(SYSCTL_HANDLER_ARGS) 2083{ 2084 linker_file_t lf; 2085 int error; 2086 2087#ifdef MAC 2088 error = mac_kld_check_stat(req->td->td_ucred); 2089 if (error) 2090 return (error); 2091#endif 2092 error = sysctl_wire_old_buffer(req, 0); 2093 if (error != 0) 2094 return (error); 2095 KLD_LOCK(); 2096 TAILQ_FOREACH(lf, &linker_files, link) { 2097 error = LINKER_EACH_FUNCTION_NAME(lf, 2098 sysctl_kern_function_list_iterate, req); 2099 if (error) { 2100 KLD_UNLOCK(); 2101 return (error); 2102 } 2103 } 2104 KLD_UNLOCK(); 2105 return (SYSCTL_OUT(req, "", 1)); 2106} 2107 2108SYSCTL_PROC(_kern, OID_AUTO, function_list, CTLFLAG_RD, 2109 NULL, 0, sysctl_kern_function_list, "", "kernel function list"); 2110