kern_linker.c revision 254267
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 254267 2013-08-13 03:09:00Z markj $"); 29 30#include "opt_ddb.h" 31#include "opt_kld.h" 32#include "opt_hwpmc_hooks.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/eventhandler.h> 49#include <sys/fcntl.h> 50#include <sys/jail.h> 51#include <sys/libkern.h> 52#include <sys/namei.h> 53#include <sys/vnode.h> 54#include <sys/syscallsubr.h> 55#include <sys/sysctl.h> 56 57#include <net/vnet.h> 58 59#include <security/mac/mac_framework.h> 60 61#include "linker_if.h" 62 63#ifdef HWPMC_HOOKS 64#include <sys/pmckern.h> 65#endif 66 67#ifdef KLD_DEBUG 68int kld_debug = 0; 69SYSCTL_INT(_debug, OID_AUTO, kld_debug, CTLFLAG_RW | CTLFLAG_TUN, 70 &kld_debug, 0, "Set various levels of KLD debug"); 71TUNABLE_INT("debug.kld_debug", &kld_debug); 72#endif 73 74#define KLD_LOCK() sx_xlock(&kld_sx) 75#define KLD_UNLOCK() sx_xunlock(&kld_sx) 76#define KLD_DOWNGRADE() sx_downgrade(&kld_sx) 77#define KLD_LOCK_READ() sx_slock(&kld_sx) 78#define KLD_UNLOCK_READ() sx_sunlock(&kld_sx) 79#define KLD_LOCKED() sx_xlocked(&kld_sx) 80#define KLD_LOCK_ASSERT() do { \ 81 if (!cold) \ 82 sx_assert(&kld_sx, SX_XLOCKED); \ 83} while (0) 84 85/* 86 * static char *linker_search_path(const char *name, struct mod_depend 87 * *verinfo); 88 */ 89static const char *linker_basename(const char *path); 90 91/* 92 * Find a currently loaded file given its filename. 93 */ 94static linker_file_t linker_find_file_by_name(const char* _filename); 95 96/* 97 * Find a currently loaded file given its file id. 98 */ 99static linker_file_t linker_find_file_by_id(int _fileid); 100 101/* Metadata from the static kernel */ 102SET_DECLARE(modmetadata_set, struct mod_metadata); 103 104MALLOC_DEFINE(M_LINKER, "linker", "kernel linker"); 105 106linker_file_t linker_kernel_file; 107 108static struct sx kld_sx; /* kernel linker lock */ 109 110/* 111 * Load counter used by clients to determine if a linker file has been 112 * re-loaded. This counter is incremented for each file load. 113 */ 114static int loadcnt; 115 116static linker_class_list_t classes; 117static linker_file_list_t linker_files; 118static int next_file_id = 1; 119static int linker_no_more_classes = 0; 120 121#define LINKER_GET_NEXT_FILE_ID(a) do { \ 122 linker_file_t lftmp; \ 123 \ 124 KLD_LOCK_ASSERT(); \ 125retry: \ 126 TAILQ_FOREACH(lftmp, &linker_files, link) { \ 127 if (next_file_id == lftmp->id) { \ 128 next_file_id++; \ 129 goto retry; \ 130 } \ 131 } \ 132 (a) = next_file_id; \ 133} while(0) 134 135 136/* XXX wrong name; we're looking at version provision tags here, not modules */ 137typedef TAILQ_HEAD(, modlist) modlisthead_t; 138struct modlist { 139 TAILQ_ENTRY(modlist) link; /* chain together all modules */ 140 linker_file_t container; 141 const char *name; 142 int version; 143}; 144typedef struct modlist *modlist_t; 145static modlisthead_t found_modules; 146 147static int linker_file_add_dependency(linker_file_t file, 148 linker_file_t dep); 149static caddr_t linker_file_lookup_symbol_internal(linker_file_t file, 150 const char* name, int deps); 151static int linker_load_module(const char *kldname, 152 const char *modname, struct linker_file *parent, 153 struct mod_depend *verinfo, struct linker_file **lfpp); 154static modlist_t modlist_lookup2(const char *name, struct mod_depend *verinfo); 155 156static char * 157linker_strdup(const char *str) 158{ 159 char *result; 160 161 if ((result = malloc((strlen(str) + 1), M_LINKER, M_WAITOK)) != NULL) 162 strcpy(result, str); 163 return (result); 164} 165 166static void 167linker_init(void *arg) 168{ 169 170 sx_init(&kld_sx, "kernel linker"); 171 TAILQ_INIT(&classes); 172 TAILQ_INIT(&linker_files); 173} 174 175SYSINIT(linker, SI_SUB_KLD, SI_ORDER_FIRST, linker_init, 0); 176 177static void 178linker_stop_class_add(void *arg) 179{ 180 181 linker_no_more_classes = 1; 182} 183 184SYSINIT(linker_class, SI_SUB_KLD, SI_ORDER_ANY, linker_stop_class_add, NULL); 185 186int 187linker_add_class(linker_class_t lc) 188{ 189 190 /* 191 * We disallow any class registration past SI_ORDER_ANY 192 * of SI_SUB_KLD. We bump the reference count to keep the 193 * ops from being freed. 194 */ 195 if (linker_no_more_classes == 1) 196 return (EPERM); 197 kobj_class_compile((kobj_class_t) lc); 198 ((kobj_class_t)lc)->refs++; /* XXX: kobj_mtx */ 199 TAILQ_INSERT_TAIL(&classes, lc, link); 200 return (0); 201} 202 203static void 204linker_file_sysinit(linker_file_t lf) 205{ 206 struct sysinit **start, **stop, **sipp, **xipp, *save; 207 208 KLD_DPF(FILE, ("linker_file_sysinit: calling SYSINITs for %s\n", 209 lf->filename)); 210 211 if (linker_file_lookup_set(lf, "sysinit_set", &start, &stop, NULL) != 0) 212 return; 213 /* 214 * Perform a bubble sort of the system initialization objects by 215 * their subsystem (primary key) and order (secondary key). 216 * 217 * Since some things care about execution order, this is the operation 218 * which ensures continued function. 219 */ 220 for (sipp = start; sipp < stop; sipp++) { 221 for (xipp = sipp + 1; xipp < stop; xipp++) { 222 if ((*sipp)->subsystem < (*xipp)->subsystem || 223 ((*sipp)->subsystem == (*xipp)->subsystem && 224 (*sipp)->order <= (*xipp)->order)) 225 continue; /* skip */ 226 save = *sipp; 227 *sipp = *xipp; 228 *xipp = save; 229 } 230 } 231 232 /* 233 * Traverse the (now) ordered list of system initialization tasks. 234 * Perform each task, and continue on to the next task. 235 */ 236 mtx_lock(&Giant); 237 for (sipp = start; sipp < stop; sipp++) { 238 if ((*sipp)->subsystem == SI_SUB_DUMMY) 239 continue; /* skip dummy task(s) */ 240 241 /* Call function */ 242 (*((*sipp)->func)) ((*sipp)->udata); 243 } 244 mtx_unlock(&Giant); 245} 246 247static void 248linker_file_sysuninit(linker_file_t lf) 249{ 250 struct sysinit **start, **stop, **sipp, **xipp, *save; 251 252 KLD_DPF(FILE, ("linker_file_sysuninit: calling SYSUNINITs for %s\n", 253 lf->filename)); 254 255 if (linker_file_lookup_set(lf, "sysuninit_set", &start, &stop, 256 NULL) != 0) 257 return; 258 259 /* 260 * Perform a reverse bubble sort of the system initialization objects 261 * by their subsystem (primary key) and order (secondary key). 262 * 263 * Since some things care about execution order, this is the operation 264 * which ensures continued function. 265 */ 266 for (sipp = start; sipp < stop; sipp++) { 267 for (xipp = sipp + 1; xipp < stop; xipp++) { 268 if ((*sipp)->subsystem > (*xipp)->subsystem || 269 ((*sipp)->subsystem == (*xipp)->subsystem && 270 (*sipp)->order >= (*xipp)->order)) 271 continue; /* skip */ 272 save = *sipp; 273 *sipp = *xipp; 274 *xipp = save; 275 } 276 } 277 278 /* 279 * Traverse the (now) ordered list of system initialization tasks. 280 * Perform each task, and continue on to the next task. 281 */ 282 mtx_lock(&Giant); 283 for (sipp = start; sipp < stop; sipp++) { 284 if ((*sipp)->subsystem == SI_SUB_DUMMY) 285 continue; /* skip dummy task(s) */ 286 287 /* Call function */ 288 (*((*sipp)->func)) ((*sipp)->udata); 289 } 290 mtx_unlock(&Giant); 291} 292 293static void 294linker_file_register_sysctls(linker_file_t lf) 295{ 296 struct sysctl_oid **start, **stop, **oidp; 297 298 KLD_DPF(FILE, 299 ("linker_file_register_sysctls: registering SYSCTLs for %s\n", 300 lf->filename)); 301 302 if (linker_file_lookup_set(lf, "sysctl_set", &start, &stop, NULL) != 0) 303 return; 304 305 sysctl_lock(); 306 for (oidp = start; oidp < stop; oidp++) 307 sysctl_register_oid(*oidp); 308 sysctl_unlock(); 309} 310 311static void 312linker_file_unregister_sysctls(linker_file_t lf) 313{ 314 struct sysctl_oid **start, **stop, **oidp; 315 316 KLD_DPF(FILE, ("linker_file_unregister_sysctls: unregistering SYSCTLs" 317 " for %s\n", lf->filename)); 318 319 if (linker_file_lookup_set(lf, "sysctl_set", &start, &stop, NULL) != 0) 320 return; 321 322 sysctl_lock(); 323 for (oidp = start; oidp < stop; oidp++) 324 sysctl_unregister_oid(*oidp); 325 sysctl_unlock(); 326} 327 328static int 329linker_file_register_modules(linker_file_t lf) 330{ 331 struct mod_metadata **start, **stop, **mdp; 332 const moduledata_t *moddata; 333 int first_error, error; 334 335 KLD_DPF(FILE, ("linker_file_register_modules: registering modules" 336 " in %s\n", lf->filename)); 337 338 if (linker_file_lookup_set(lf, "modmetadata_set", &start, 339 &stop, NULL) != 0) { 340 /* 341 * This fallback should be unnecessary, but if we get booted 342 * from boot2 instead of loader and we are missing our 343 * metadata then we have to try the best we can. 344 */ 345 if (lf == linker_kernel_file) { 346 start = SET_BEGIN(modmetadata_set); 347 stop = SET_LIMIT(modmetadata_set); 348 } else 349 return (0); 350 } 351 first_error = 0; 352 for (mdp = start; mdp < stop; mdp++) { 353 if ((*mdp)->md_type != MDT_MODULE) 354 continue; 355 moddata = (*mdp)->md_data; 356 KLD_DPF(FILE, ("Registering module %s in %s\n", 357 moddata->name, lf->filename)); 358 error = module_register(moddata, lf); 359 if (error) { 360 printf("Module %s failed to register: %d\n", 361 moddata->name, error); 362 if (first_error == 0) 363 first_error = error; 364 } 365 } 366 return (first_error); 367} 368 369static void 370linker_init_kernel_modules(void) 371{ 372 373 linker_file_register_modules(linker_kernel_file); 374} 375 376SYSINIT(linker_kernel, SI_SUB_KLD, SI_ORDER_ANY, linker_init_kernel_modules, 377 0); 378 379static int 380linker_load_file(const char *filename, linker_file_t *result) 381{ 382 linker_class_t lc; 383 linker_file_t lf; 384 int foundfile, error, modules; 385 386 /* Refuse to load modules if securelevel raised */ 387 if (prison0.pr_securelevel > 0) 388 return (EPERM); 389 390 KLD_LOCK_ASSERT(); 391 lf = linker_find_file_by_name(filename); 392 if (lf) { 393 KLD_DPF(FILE, ("linker_load_file: file %s is already loaded," 394 " incrementing refs\n", filename)); 395 *result = lf; 396 lf->refs++; 397 return (0); 398 } 399 foundfile = 0; 400 error = 0; 401 402 /* 403 * We do not need to protect (lock) classes here because there is 404 * no class registration past startup (SI_SUB_KLD, SI_ORDER_ANY) 405 * and there is no class deregistration mechanism at this time. 406 */ 407 TAILQ_FOREACH(lc, &classes, link) { 408 KLD_DPF(FILE, ("linker_load_file: trying to load %s\n", 409 filename)); 410 error = LINKER_LOAD_FILE(lc, filename, &lf); 411 /* 412 * If we got something other than ENOENT, then it exists but 413 * we cannot load it for some other reason. 414 */ 415 if (error != ENOENT) 416 foundfile = 1; 417 if (lf) { 418 error = linker_file_register_modules(lf); 419 if (error == EEXIST) { 420 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 421 return (error); 422 } 423 modules = !TAILQ_EMPTY(&lf->modules); 424 KLD_UNLOCK(); 425 linker_file_register_sysctls(lf); 426 linker_file_sysinit(lf); 427 KLD_LOCK(); 428 lf->flags |= LINKER_FILE_LINKED; 429 430 /* 431 * If all of the modules in this file failed 432 * to load, unload the file and return an 433 * error of ENOEXEC. 434 */ 435 if (modules && TAILQ_EMPTY(&lf->modules)) { 436 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 437 return (ENOEXEC); 438 } 439 *result = lf; 440 return (0); 441 } 442 } 443 /* 444 * Less than ideal, but tells the user whether it failed to load or 445 * the module was not found. 446 */ 447 if (foundfile) { 448 449 /* 450 * If the file type has not been recognized by the last try 451 * printout a message before to fail. 452 */ 453 if (error == ENOSYS) 454 printf("linker_load_file: Unsupported file type\n"); 455 456 /* 457 * Format not recognized or otherwise unloadable. 458 * When loading a module that is statically built into 459 * the kernel EEXIST percolates back up as the return 460 * value. Preserve this so that apps like sysinstall 461 * can recognize this special case and not post bogus 462 * dialog boxes. 463 */ 464 if (error != EEXIST) 465 error = ENOEXEC; 466 } else 467 error = ENOENT; /* Nothing found */ 468 return (error); 469} 470 471int 472linker_reference_module(const char *modname, struct mod_depend *verinfo, 473 linker_file_t *result) 474{ 475 modlist_t mod; 476 int error; 477 478 KLD_LOCK(); 479 if ((mod = modlist_lookup2(modname, verinfo)) != NULL) { 480 *result = mod->container; 481 (*result)->refs++; 482 KLD_UNLOCK(); 483 return (0); 484 } 485 486 error = linker_load_module(NULL, modname, NULL, verinfo, result); 487 KLD_UNLOCK(); 488 return (error); 489} 490 491int 492linker_release_module(const char *modname, struct mod_depend *verinfo, 493 linker_file_t lf) 494{ 495 modlist_t mod; 496 int error; 497 498 KLD_LOCK(); 499 if (lf == NULL) { 500 KASSERT(modname != NULL, 501 ("linker_release_module: no file or name")); 502 mod = modlist_lookup2(modname, verinfo); 503 if (mod == NULL) { 504 KLD_UNLOCK(); 505 return (ESRCH); 506 } 507 lf = mod->container; 508 } else 509 KASSERT(modname == NULL && verinfo == NULL, 510 ("linker_release_module: both file and name")); 511 error = linker_file_unload(lf, LINKER_UNLOAD_NORMAL); 512 KLD_UNLOCK(); 513 return (error); 514} 515 516static linker_file_t 517linker_find_file_by_name(const char *filename) 518{ 519 linker_file_t lf; 520 char *koname; 521 522 koname = malloc(strlen(filename) + 4, M_LINKER, M_WAITOK); 523 sprintf(koname, "%s.ko", filename); 524 525 KLD_LOCK_ASSERT(); 526 TAILQ_FOREACH(lf, &linker_files, link) { 527 if (strcmp(lf->filename, koname) == 0) 528 break; 529 if (strcmp(lf->filename, filename) == 0) 530 break; 531 } 532 free(koname, M_LINKER); 533 return (lf); 534} 535 536static linker_file_t 537linker_find_file_by_id(int fileid) 538{ 539 linker_file_t lf; 540 541 KLD_LOCK_ASSERT(); 542 TAILQ_FOREACH(lf, &linker_files, link) 543 if (lf->id == fileid && lf->flags & LINKER_FILE_LINKED) 544 break; 545 return (lf); 546} 547 548int 549linker_file_foreach(linker_predicate_t *predicate, void *context) 550{ 551 linker_file_t lf; 552 int retval = 0; 553 554 KLD_LOCK(); 555 TAILQ_FOREACH(lf, &linker_files, link) { 556 retval = predicate(lf, context); 557 if (retval != 0) 558 break; 559 } 560 KLD_UNLOCK(); 561 return (retval); 562} 563 564linker_file_t 565linker_make_file(const char *pathname, linker_class_t lc) 566{ 567 linker_file_t lf; 568 const char *filename; 569 570 KLD_LOCK_ASSERT(); 571 filename = linker_basename(pathname); 572 573 KLD_DPF(FILE, ("linker_make_file: new file, filename='%s' for pathname='%s'\n", filename, pathname)); 574 lf = (linker_file_t)kobj_create((kobj_class_t)lc, M_LINKER, M_WAITOK); 575 if (lf == NULL) 576 return (NULL); 577 lf->refs = 1; 578 lf->userrefs = 0; 579 lf->flags = 0; 580 lf->filename = linker_strdup(filename); 581 lf->pathname = linker_strdup(pathname); 582 LINKER_GET_NEXT_FILE_ID(lf->id); 583 lf->ndeps = 0; 584 lf->deps = NULL; 585 lf->loadcnt = ++loadcnt; 586 STAILQ_INIT(&lf->common); 587 TAILQ_INIT(&lf->modules); 588 TAILQ_INSERT_TAIL(&linker_files, lf, link); 589 return (lf); 590} 591 592int 593linker_file_unload(linker_file_t file, int flags) 594{ 595 module_t mod, next; 596 modlist_t ml, nextml; 597 struct common_symbol *cp; 598 int error, i; 599 600 /* Refuse to unload modules if securelevel raised. */ 601 if (prison0.pr_securelevel > 0) 602 return (EPERM); 603 604 KLD_LOCK_ASSERT(); 605 KLD_DPF(FILE, ("linker_file_unload: lf->refs=%d\n", file->refs)); 606 607 /* Easy case of just dropping a reference. */ 608 if (file->refs > 1) { 609 file->refs--; 610 return (0); 611 } 612 613 KLD_DPF(FILE, ("linker_file_unload: file is unloading," 614 " informing modules\n")); 615 616 /* 617 * Quiesce all the modules to give them a chance to veto the unload. 618 */ 619 MOD_SLOCK; 620 for (mod = TAILQ_FIRST(&file->modules); mod; 621 mod = module_getfnext(mod)) { 622 623 error = module_quiesce(mod); 624 if (error != 0 && flags != LINKER_UNLOAD_FORCE) { 625 KLD_DPF(FILE, ("linker_file_unload: module %s" 626 " vetoed unload\n", module_getname(mod))); 627 /* 628 * XXX: Do we need to tell all the quiesced modules 629 * that they can resume work now via a new module 630 * event? 631 */ 632 MOD_SUNLOCK; 633 return (error); 634 } 635 } 636 MOD_SUNLOCK; 637 638 /* 639 * Inform any modules associated with this file that they are 640 * being unloaded. 641 */ 642 MOD_XLOCK; 643 for (mod = TAILQ_FIRST(&file->modules); mod; mod = next) { 644 next = module_getfnext(mod); 645 MOD_XUNLOCK; 646 647 /* 648 * Give the module a chance to veto the unload. 649 */ 650 if ((error = module_unload(mod)) != 0) { 651#ifdef KLD_DEBUG 652 MOD_SLOCK; 653 KLD_DPF(FILE, ("linker_file_unload: module %s" 654 " failed unload\n", module_getname(mod))); 655 MOD_SUNLOCK; 656#endif 657 return (error); 658 } 659 MOD_XLOCK; 660 module_release(mod); 661 } 662 MOD_XUNLOCK; 663 664 TAILQ_FOREACH_SAFE(ml, &found_modules, link, nextml) { 665 if (ml->container == file) { 666 TAILQ_REMOVE(&found_modules, ml, link); 667 free(ml, M_LINKER); 668 } 669 } 670 671 /* 672 * Don't try to run SYSUNINITs if we are unloaded due to a 673 * link error. 674 */ 675 if (file->flags & LINKER_FILE_LINKED) { 676 file->flags &= ~LINKER_FILE_LINKED; 677 KLD_UNLOCK(); 678 linker_file_sysuninit(file); 679 linker_file_unregister_sysctls(file); 680 KLD_LOCK(); 681 } 682 TAILQ_REMOVE(&linker_files, file, link); 683 684 if (file->deps) { 685 for (i = 0; i < file->ndeps; i++) 686 linker_file_unload(file->deps[i], flags); 687 free(file->deps, M_LINKER); 688 file->deps = NULL; 689 } 690 while ((cp = STAILQ_FIRST(&file->common)) != NULL) { 691 STAILQ_REMOVE_HEAD(&file->common, link); 692 free(cp, M_LINKER); 693 } 694 695 LINKER_UNLOAD(file); 696 if (file->filename) { 697 free(file->filename, M_LINKER); 698 file->filename = NULL; 699 } 700 if (file->pathname) { 701 free(file->pathname, M_LINKER); 702 file->pathname = NULL; 703 } 704 kobj_delete((kobj_t) file, M_LINKER); 705 return (0); 706} 707 708int 709linker_ctf_get(linker_file_t file, linker_ctf_t *lc) 710{ 711 return (LINKER_CTF_GET(file, lc)); 712} 713 714static int 715linker_file_add_dependency(linker_file_t file, linker_file_t dep) 716{ 717 linker_file_t *newdeps; 718 719 KLD_LOCK_ASSERT(); 720 newdeps = malloc((file->ndeps + 1) * sizeof(linker_file_t *), 721 M_LINKER, M_WAITOK | M_ZERO); 722 if (newdeps == NULL) 723 return (ENOMEM); 724 725 if (file->deps) { 726 bcopy(file->deps, newdeps, 727 file->ndeps * sizeof(linker_file_t *)); 728 free(file->deps, M_LINKER); 729 } 730 file->deps = newdeps; 731 file->deps[file->ndeps] = dep; 732 file->ndeps++; 733 KLD_DPF(FILE, ("linker_file_add_dependency:" 734 " adding %s as dependency for %s\n", 735 dep->filename, file->filename)); 736 return (0); 737} 738 739/* 740 * Locate a linker set and its contents. This is a helper function to avoid 741 * linker_if.h exposure elsewhere. Note: firstp and lastp are really void **. 742 * This function is used in this file so we can avoid having lots of (void **) 743 * casts. 744 */ 745int 746linker_file_lookup_set(linker_file_t file, const char *name, 747 void *firstp, void *lastp, int *countp) 748{ 749 int error, locked; 750 751 locked = KLD_LOCKED(); 752 if (!locked) 753 KLD_LOCK(); 754 error = LINKER_LOOKUP_SET(file, name, firstp, lastp, countp); 755 if (!locked) 756 KLD_UNLOCK(); 757 return (error); 758} 759 760/* 761 * List all functions in a file. 762 */ 763int 764linker_file_function_listall(linker_file_t lf, 765 linker_function_nameval_callback_t callback_func, void *arg) 766{ 767 return (LINKER_EACH_FUNCTION_NAMEVAL(lf, callback_func, arg)); 768} 769 770caddr_t 771linker_file_lookup_symbol(linker_file_t file, const char *name, int deps) 772{ 773 caddr_t sym; 774 int locked; 775 776 locked = KLD_LOCKED(); 777 if (!locked) 778 KLD_LOCK(); 779 sym = linker_file_lookup_symbol_internal(file, name, deps); 780 if (!locked) 781 KLD_UNLOCK(); 782 return (sym); 783} 784 785static caddr_t 786linker_file_lookup_symbol_internal(linker_file_t file, const char *name, 787 int deps) 788{ 789 c_linker_sym_t sym; 790 linker_symval_t symval; 791 caddr_t address; 792 size_t common_size = 0; 793 int i; 794 795 KLD_LOCK_ASSERT(); 796 KLD_DPF(SYM, ("linker_file_lookup_symbol: file=%p, name=%s, deps=%d\n", 797 file, name, deps)); 798 799 if (LINKER_LOOKUP_SYMBOL(file, name, &sym) == 0) { 800 LINKER_SYMBOL_VALUES(file, sym, &symval); 801 if (symval.value == 0) 802 /* 803 * For commons, first look them up in the 804 * dependencies and only allocate space if not found 805 * there. 806 */ 807 common_size = symval.size; 808 else { 809 KLD_DPF(SYM, ("linker_file_lookup_symbol: symbol" 810 ".value=%p\n", symval.value)); 811 return (symval.value); 812 } 813 } 814 if (deps) { 815 for (i = 0; i < file->ndeps; i++) { 816 address = linker_file_lookup_symbol_internal( 817 file->deps[i], name, 0); 818 if (address) { 819 KLD_DPF(SYM, ("linker_file_lookup_symbol:" 820 " deps value=%p\n", address)); 821 return (address); 822 } 823 } 824 } 825 if (common_size > 0) { 826 /* 827 * This is a common symbol which was not found in the 828 * dependencies. We maintain a simple common symbol table in 829 * the file object. 830 */ 831 struct common_symbol *cp; 832 833 STAILQ_FOREACH(cp, &file->common, link) { 834 if (strcmp(cp->name, name) == 0) { 835 KLD_DPF(SYM, ("linker_file_lookup_symbol:" 836 " old common value=%p\n", cp->address)); 837 return (cp->address); 838 } 839 } 840 /* 841 * Round the symbol size up to align. 842 */ 843 common_size = (common_size + sizeof(int) - 1) & -sizeof(int); 844 cp = malloc(sizeof(struct common_symbol) 845 + common_size + strlen(name) + 1, M_LINKER, 846 M_WAITOK | M_ZERO); 847 cp->address = (caddr_t)(cp + 1); 848 cp->name = cp->address + common_size; 849 strcpy(cp->name, name); 850 bzero(cp->address, common_size); 851 STAILQ_INSERT_TAIL(&file->common, cp, link); 852 853 KLD_DPF(SYM, ("linker_file_lookup_symbol: new common" 854 " value=%p\n", cp->address)); 855 return (cp->address); 856 } 857 KLD_DPF(SYM, ("linker_file_lookup_symbol: fail\n")); 858 return (0); 859} 860 861/* 862 * Both DDB and stack(9) rely on the kernel linker to provide forward and 863 * backward lookup of symbols. However, DDB and sometimes stack(9) need to 864 * do this in a lockfree manner. We provide a set of internal helper 865 * routines to perform these operations without locks, and then wrappers that 866 * optionally lock. 867 * 868 * linker_debug_lookup() is ifdef DDB as currently it's only used by DDB. 869 */ 870#ifdef DDB 871static int 872linker_debug_lookup(const char *symstr, c_linker_sym_t *sym) 873{ 874 linker_file_t lf; 875 876 TAILQ_FOREACH(lf, &linker_files, link) { 877 if (LINKER_LOOKUP_SYMBOL(lf, symstr, sym) == 0) 878 return (0); 879 } 880 return (ENOENT); 881} 882#endif 883 884static int 885linker_debug_search_symbol(caddr_t value, c_linker_sym_t *sym, long *diffp) 886{ 887 linker_file_t lf; 888 c_linker_sym_t best, es; 889 u_long diff, bestdiff, off; 890 891 best = 0; 892 off = (uintptr_t)value; 893 bestdiff = off; 894 TAILQ_FOREACH(lf, &linker_files, link) { 895 if (LINKER_SEARCH_SYMBOL(lf, value, &es, &diff) != 0) 896 continue; 897 if (es != 0 && diff < bestdiff) { 898 best = es; 899 bestdiff = diff; 900 } 901 if (bestdiff == 0) 902 break; 903 } 904 if (best) { 905 *sym = best; 906 *diffp = bestdiff; 907 return (0); 908 } else { 909 *sym = 0; 910 *diffp = off; 911 return (ENOENT); 912 } 913} 914 915static int 916linker_debug_symbol_values(c_linker_sym_t sym, linker_symval_t *symval) 917{ 918 linker_file_t lf; 919 920 TAILQ_FOREACH(lf, &linker_files, link) { 921 if (LINKER_SYMBOL_VALUES(lf, sym, symval) == 0) 922 return (0); 923 } 924 return (ENOENT); 925} 926 927static int 928linker_debug_search_symbol_name(caddr_t value, char *buf, u_int buflen, 929 long *offset) 930{ 931 linker_symval_t symval; 932 c_linker_sym_t sym; 933 int error; 934 935 *offset = 0; 936 error = linker_debug_search_symbol(value, &sym, offset); 937 if (error) 938 return (error); 939 error = linker_debug_symbol_values(sym, &symval); 940 if (error) 941 return (error); 942 strlcpy(buf, symval.name, buflen); 943 return (0); 944} 945 946/* 947 * DDB Helpers. DDB has to look across multiple files with their own symbol 948 * tables and string tables. 949 * 950 * Note that we do not obey list locking protocols here. We really don't need 951 * DDB to hang because somebody's got the lock held. We'll take the chance 952 * that the files list is inconsistant instead. 953 */ 954#ifdef DDB 955int 956linker_ddb_lookup(const char *symstr, c_linker_sym_t *sym) 957{ 958 959 return (linker_debug_lookup(symstr, sym)); 960} 961#endif 962 963int 964linker_ddb_search_symbol(caddr_t value, c_linker_sym_t *sym, long *diffp) 965{ 966 967 return (linker_debug_search_symbol(value, sym, diffp)); 968} 969 970int 971linker_ddb_symbol_values(c_linker_sym_t sym, linker_symval_t *symval) 972{ 973 974 return (linker_debug_symbol_values(sym, symval)); 975} 976 977int 978linker_ddb_search_symbol_name(caddr_t value, char *buf, u_int buflen, 979 long *offset) 980{ 981 982 return (linker_debug_search_symbol_name(value, buf, buflen, offset)); 983} 984 985/* 986 * stack(9) helper for non-debugging environemnts. Unlike DDB helpers, we do 987 * obey locking protocols, and offer a significantly less complex interface. 988 */ 989int 990linker_search_symbol_name(caddr_t value, char *buf, u_int buflen, 991 long *offset) 992{ 993 int error; 994 995 KLD_LOCK(); 996 error = linker_debug_search_symbol_name(value, buf, buflen, offset); 997 KLD_UNLOCK(); 998 return (error); 999} 1000 1001/* 1002 * Syscalls. 1003 */ 1004int 1005kern_kldload(struct thread *td, const char *file, int *fileid) 1006{ 1007#ifdef HWPMC_HOOKS 1008 struct pmckern_map_in pkm; 1009#endif 1010 const char *kldname, *modname; 1011 linker_file_t lf; 1012 int error; 1013 1014 if ((error = securelevel_gt(td->td_ucred, 0)) != 0) 1015 return (error); 1016 1017 if ((error = priv_check(td, PRIV_KLD_LOAD)) != 0) 1018 return (error); 1019 1020 /* 1021 * It is possible that kldloaded module will attach a new ifnet, 1022 * so vnet context must be set when this ocurs. 1023 */ 1024 CURVNET_SET(TD_TO_VNET(td)); 1025 1026 /* 1027 * If file does not contain a qualified name or any dot in it 1028 * (kldname.ko, or kldname.ver.ko) treat it as an interface 1029 * name. 1030 */ 1031 if (strchr(file, '/') || strchr(file, '.')) { 1032 kldname = file; 1033 modname = NULL; 1034 } else { 1035 kldname = NULL; 1036 modname = file; 1037 } 1038 1039 KLD_LOCK(); 1040 error = linker_load_module(kldname, modname, NULL, NULL, &lf); 1041 if (error) { 1042 KLD_UNLOCK(); 1043 goto done; 1044 } 1045 lf->userrefs++; 1046 if (fileid != NULL) 1047 *fileid = lf->id; 1048 1049 EVENTHANDLER_INVOKE(mod_load, lf); 1050 1051#ifdef HWPMC_HOOKS 1052 KLD_DOWNGRADE(); 1053 pkm.pm_file = lf->filename; 1054 pkm.pm_address = (uintptr_t) lf->address; 1055 PMC_CALL_HOOK(td, PMC_FN_KLD_LOAD, (void *) &pkm); 1056 KLD_UNLOCK_READ(); 1057#else 1058 KLD_UNLOCK(); 1059#endif 1060 1061done: 1062 CURVNET_RESTORE(); 1063 return (error); 1064} 1065 1066int 1067sys_kldload(struct thread *td, struct kldload_args *uap) 1068{ 1069 char *pathname = NULL; 1070 int error, fileid; 1071 1072 td->td_retval[0] = -1; 1073 1074 pathname = malloc(MAXPATHLEN, M_TEMP, M_WAITOK); 1075 error = copyinstr(uap->file, pathname, MAXPATHLEN, NULL); 1076 if (error == 0) { 1077 error = kern_kldload(td, pathname, &fileid); 1078 if (error == 0) 1079 td->td_retval[0] = fileid; 1080 } 1081 free(pathname, M_TEMP); 1082 return (error); 1083} 1084 1085int 1086kern_kldunload(struct thread *td, int fileid, int flags) 1087{ 1088#ifdef HWPMC_HOOKS 1089 struct pmckern_map_out pkm; 1090#endif 1091 linker_file_t lf; 1092 int error = 0; 1093 1094 if ((error = securelevel_gt(td->td_ucred, 0)) != 0) 1095 return (error); 1096 1097 if ((error = priv_check(td, PRIV_KLD_UNLOAD)) != 0) 1098 return (error); 1099 1100 CURVNET_SET(TD_TO_VNET(td)); 1101 KLD_LOCK(); 1102 lf = linker_find_file_by_id(fileid); 1103 if (lf) { 1104 KLD_DPF(FILE, ("kldunload: lf->userrefs=%d\n", lf->userrefs)); 1105 1106 EVENTHANDLER_INVOKE(mod_unload, lf, &error); 1107 if (error != 0) 1108 error = EBUSY; 1109 else if (lf->nenabled > 0) { 1110 printf("kldunload: attempt to unload file that has" 1111 " DTrace probes enabled\n"); 1112 error = EBUSY; 1113 } else if (lf->userrefs == 0) { 1114 /* 1115 * XXX: maybe LINKER_UNLOAD_FORCE should override ? 1116 */ 1117 printf("kldunload: attempt to unload file that was" 1118 " loaded by the kernel\n"); 1119 error = EBUSY; 1120 } else { 1121#ifdef HWPMC_HOOKS 1122 /* Save data needed by hwpmc(4) before unloading. */ 1123 pkm.pm_address = (uintptr_t) lf->address; 1124 pkm.pm_size = lf->size; 1125#endif 1126 lf->userrefs--; 1127 error = linker_file_unload(lf, flags); 1128 if (error) 1129 lf->userrefs++; 1130 } 1131 } else 1132 error = ENOENT; 1133 1134#ifdef HWPMC_HOOKS 1135 if (error == 0) { 1136 KLD_DOWNGRADE(); 1137 PMC_CALL_HOOK(td, PMC_FN_KLD_UNLOAD, (void *) &pkm); 1138 KLD_UNLOCK_READ(); 1139 } else 1140 KLD_UNLOCK(); 1141#else 1142 KLD_UNLOCK(); 1143#endif 1144 CURVNET_RESTORE(); 1145 return (error); 1146} 1147 1148int 1149sys_kldunload(struct thread *td, struct kldunload_args *uap) 1150{ 1151 1152 return (kern_kldunload(td, uap->fileid, LINKER_UNLOAD_NORMAL)); 1153} 1154 1155int 1156sys_kldunloadf(struct thread *td, struct kldunloadf_args *uap) 1157{ 1158 1159 if (uap->flags != LINKER_UNLOAD_NORMAL && 1160 uap->flags != LINKER_UNLOAD_FORCE) 1161 return (EINVAL); 1162 return (kern_kldunload(td, uap->fileid, uap->flags)); 1163} 1164 1165int 1166sys_kldfind(struct thread *td, struct kldfind_args *uap) 1167{ 1168 char *pathname; 1169 const char *filename; 1170 linker_file_t lf; 1171 int error; 1172 1173#ifdef MAC 1174 error = mac_kld_check_stat(td->td_ucred); 1175 if (error) 1176 return (error); 1177#endif 1178 1179 td->td_retval[0] = -1; 1180 1181 pathname = malloc(MAXPATHLEN, M_TEMP, M_WAITOK); 1182 if ((error = copyinstr(uap->file, pathname, MAXPATHLEN, NULL)) != 0) 1183 goto out; 1184 1185 filename = linker_basename(pathname); 1186 KLD_LOCK(); 1187 lf = linker_find_file_by_name(filename); 1188 if (lf) 1189 td->td_retval[0] = lf->id; 1190 else 1191 error = ENOENT; 1192 KLD_UNLOCK(); 1193out: 1194 free(pathname, M_TEMP); 1195 return (error); 1196} 1197 1198int 1199sys_kldnext(struct thread *td, struct kldnext_args *uap) 1200{ 1201 linker_file_t lf; 1202 int error = 0; 1203 1204#ifdef MAC 1205 error = mac_kld_check_stat(td->td_ucred); 1206 if (error) 1207 return (error); 1208#endif 1209 1210 KLD_LOCK(); 1211 if (uap->fileid == 0) 1212 lf = TAILQ_FIRST(&linker_files); 1213 else { 1214 lf = linker_find_file_by_id(uap->fileid); 1215 if (lf == NULL) { 1216 error = ENOENT; 1217 goto out; 1218 } 1219 lf = TAILQ_NEXT(lf, link); 1220 } 1221 1222 /* Skip partially loaded files. */ 1223 while (lf != NULL && !(lf->flags & LINKER_FILE_LINKED)) 1224 lf = TAILQ_NEXT(lf, link); 1225 1226 if (lf) 1227 td->td_retval[0] = lf->id; 1228 else 1229 td->td_retval[0] = 0; 1230out: 1231 KLD_UNLOCK(); 1232 return (error); 1233} 1234 1235int 1236sys_kldstat(struct thread *td, struct kldstat_args *uap) 1237{ 1238 struct kld_file_stat stat; 1239 int error, version; 1240 1241 /* 1242 * Check the version of the user's structure. 1243 */ 1244 if ((error = copyin(&uap->stat->version, &version, sizeof(version))) 1245 != 0) 1246 return (error); 1247 if (version != sizeof(struct kld_file_stat_1) && 1248 version != sizeof(struct kld_file_stat)) 1249 return (EINVAL); 1250 1251 error = kern_kldstat(td, uap->fileid, &stat); 1252 if (error != 0) 1253 return (error); 1254 return (copyout(&stat, uap->stat, version)); 1255} 1256 1257int 1258kern_kldstat(struct thread *td, int fileid, struct kld_file_stat *stat) 1259{ 1260 linker_file_t lf; 1261 int namelen; 1262#ifdef MAC 1263 int error; 1264 1265 error = mac_kld_check_stat(td->td_ucred); 1266 if (error) 1267 return (error); 1268#endif 1269 1270 KLD_LOCK(); 1271 lf = linker_find_file_by_id(fileid); 1272 if (lf == NULL) { 1273 KLD_UNLOCK(); 1274 return (ENOENT); 1275 } 1276 1277 /* Version 1 fields: */ 1278 namelen = strlen(lf->filename) + 1; 1279 if (namelen > MAXPATHLEN) 1280 namelen = MAXPATHLEN; 1281 bcopy(lf->filename, &stat->name[0], namelen); 1282 stat->refs = lf->refs; 1283 stat->id = lf->id; 1284 stat->address = lf->address; 1285 stat->size = lf->size; 1286 /* Version 2 fields: */ 1287 namelen = strlen(lf->pathname) + 1; 1288 if (namelen > MAXPATHLEN) 1289 namelen = MAXPATHLEN; 1290 bcopy(lf->pathname, &stat->pathname[0], namelen); 1291 KLD_UNLOCK(); 1292 1293 td->td_retval[0] = 0; 1294 return (0); 1295} 1296 1297int 1298sys_kldfirstmod(struct thread *td, struct kldfirstmod_args *uap) 1299{ 1300 linker_file_t lf; 1301 module_t mp; 1302 int error = 0; 1303 1304#ifdef MAC 1305 error = mac_kld_check_stat(td->td_ucred); 1306 if (error) 1307 return (error); 1308#endif 1309 1310 KLD_LOCK(); 1311 lf = linker_find_file_by_id(uap->fileid); 1312 if (lf) { 1313 MOD_SLOCK; 1314 mp = TAILQ_FIRST(&lf->modules); 1315 if (mp != NULL) 1316 td->td_retval[0] = module_getid(mp); 1317 else 1318 td->td_retval[0] = 0; 1319 MOD_SUNLOCK; 1320 } else 1321 error = ENOENT; 1322 KLD_UNLOCK(); 1323 return (error); 1324} 1325 1326int 1327sys_kldsym(struct thread *td, struct kldsym_args *uap) 1328{ 1329 char *symstr = NULL; 1330 c_linker_sym_t sym; 1331 linker_symval_t symval; 1332 linker_file_t lf; 1333 struct kld_sym_lookup lookup; 1334 int error = 0; 1335 1336#ifdef MAC 1337 error = mac_kld_check_stat(td->td_ucred); 1338 if (error) 1339 return (error); 1340#endif 1341 1342 if ((error = copyin(uap->data, &lookup, sizeof(lookup))) != 0) 1343 return (error); 1344 if (lookup.version != sizeof(lookup) || 1345 uap->cmd != KLDSYM_LOOKUP) 1346 return (EINVAL); 1347 symstr = malloc(MAXPATHLEN, M_TEMP, M_WAITOK); 1348 if ((error = copyinstr(lookup.symname, symstr, MAXPATHLEN, NULL)) != 0) 1349 goto out; 1350 KLD_LOCK(); 1351 if (uap->fileid != 0) { 1352 lf = linker_find_file_by_id(uap->fileid); 1353 if (lf == NULL) 1354 error = ENOENT; 1355 else if (LINKER_LOOKUP_SYMBOL(lf, symstr, &sym) == 0 && 1356 LINKER_SYMBOL_VALUES(lf, sym, &symval) == 0) { 1357 lookup.symvalue = (uintptr_t) symval.value; 1358 lookup.symsize = symval.size; 1359 error = copyout(&lookup, uap->data, sizeof(lookup)); 1360 } else 1361 error = ENOENT; 1362 } else { 1363 TAILQ_FOREACH(lf, &linker_files, link) { 1364 if (LINKER_LOOKUP_SYMBOL(lf, symstr, &sym) == 0 && 1365 LINKER_SYMBOL_VALUES(lf, sym, &symval) == 0) { 1366 lookup.symvalue = (uintptr_t)symval.value; 1367 lookup.symsize = symval.size; 1368 error = copyout(&lookup, uap->data, 1369 sizeof(lookup)); 1370 break; 1371 } 1372 } 1373 if (lf == NULL) 1374 error = ENOENT; 1375 } 1376 KLD_UNLOCK(); 1377out: 1378 free(symstr, M_TEMP); 1379 return (error); 1380} 1381 1382/* 1383 * Preloaded module support 1384 */ 1385 1386static modlist_t 1387modlist_lookup(const char *name, int ver) 1388{ 1389 modlist_t mod; 1390 1391 TAILQ_FOREACH(mod, &found_modules, link) { 1392 if (strcmp(mod->name, name) == 0 && 1393 (ver == 0 || mod->version == ver)) 1394 return (mod); 1395 } 1396 return (NULL); 1397} 1398 1399static modlist_t 1400modlist_lookup2(const char *name, struct mod_depend *verinfo) 1401{ 1402 modlist_t mod, bestmod; 1403 int ver; 1404 1405 if (verinfo == NULL) 1406 return (modlist_lookup(name, 0)); 1407 bestmod = NULL; 1408 TAILQ_FOREACH(mod, &found_modules, link) { 1409 if (strcmp(mod->name, name) != 0) 1410 continue; 1411 ver = mod->version; 1412 if (ver == verinfo->md_ver_preferred) 1413 return (mod); 1414 if (ver >= verinfo->md_ver_minimum && 1415 ver <= verinfo->md_ver_maximum && 1416 (bestmod == NULL || ver > bestmod->version)) 1417 bestmod = mod; 1418 } 1419 return (bestmod); 1420} 1421 1422static modlist_t 1423modlist_newmodule(const char *modname, int version, linker_file_t container) 1424{ 1425 modlist_t mod; 1426 1427 mod = malloc(sizeof(struct modlist), M_LINKER, M_NOWAIT | M_ZERO); 1428 if (mod == NULL) 1429 panic("no memory for module list"); 1430 mod->container = container; 1431 mod->name = modname; 1432 mod->version = version; 1433 TAILQ_INSERT_TAIL(&found_modules, mod, link); 1434 return (mod); 1435} 1436 1437static void 1438linker_addmodules(linker_file_t lf, struct mod_metadata **start, 1439 struct mod_metadata **stop, int preload) 1440{ 1441 struct mod_metadata *mp, **mdp; 1442 const char *modname; 1443 int ver; 1444 1445 for (mdp = start; mdp < stop; mdp++) { 1446 mp = *mdp; 1447 if (mp->md_type != MDT_VERSION) 1448 continue; 1449 modname = mp->md_cval; 1450 ver = ((struct mod_version *)mp->md_data)->mv_version; 1451 if (modlist_lookup(modname, ver) != NULL) { 1452 printf("module %s already present!\n", modname); 1453 /* XXX what can we do? this is a build error. :-( */ 1454 continue; 1455 } 1456 modlist_newmodule(modname, ver, lf); 1457 } 1458} 1459 1460static void 1461linker_preload(void *arg) 1462{ 1463 caddr_t modptr; 1464 const char *modname, *nmodname; 1465 char *modtype; 1466 linker_file_t lf, nlf; 1467 linker_class_t lc; 1468 int error; 1469 linker_file_list_t loaded_files; 1470 linker_file_list_t depended_files; 1471 struct mod_metadata *mp, *nmp; 1472 struct mod_metadata **start, **stop, **mdp, **nmdp; 1473 struct mod_depend *verinfo; 1474 int nver; 1475 int resolves; 1476 modlist_t mod; 1477 struct sysinit **si_start, **si_stop; 1478 1479 TAILQ_INIT(&loaded_files); 1480 TAILQ_INIT(&depended_files); 1481 TAILQ_INIT(&found_modules); 1482 error = 0; 1483 1484 modptr = NULL; 1485 while ((modptr = preload_search_next_name(modptr)) != NULL) { 1486 modname = (char *)preload_search_info(modptr, MODINFO_NAME); 1487 modtype = (char *)preload_search_info(modptr, MODINFO_TYPE); 1488 if (modname == NULL) { 1489 printf("Preloaded module at %p does not have a" 1490 " name!\n", modptr); 1491 continue; 1492 } 1493 if (modtype == NULL) { 1494 printf("Preloaded module at %p does not have a type!\n", 1495 modptr); 1496 continue; 1497 } 1498 if (bootverbose) 1499 printf("Preloaded %s \"%s\" at %p.\n", modtype, modname, 1500 modptr); 1501 lf = NULL; 1502 TAILQ_FOREACH(lc, &classes, link) { 1503 error = LINKER_LINK_PRELOAD(lc, modname, &lf); 1504 if (!error) 1505 break; 1506 lf = NULL; 1507 } 1508 if (lf) 1509 TAILQ_INSERT_TAIL(&loaded_files, lf, loaded); 1510 } 1511 1512 /* 1513 * First get a list of stuff in the kernel. 1514 */ 1515 if (linker_file_lookup_set(linker_kernel_file, MDT_SETNAME, &start, 1516 &stop, NULL) == 0) 1517 linker_addmodules(linker_kernel_file, start, stop, 1); 1518 1519 /* 1520 * This is a once-off kinky bubble sort to resolve relocation 1521 * dependency requirements. 1522 */ 1523restart: 1524 TAILQ_FOREACH(lf, &loaded_files, loaded) { 1525 error = linker_file_lookup_set(lf, MDT_SETNAME, &start, 1526 &stop, NULL); 1527 /* 1528 * First, look to see if we would successfully link with this 1529 * stuff. 1530 */ 1531 resolves = 1; /* unless we know otherwise */ 1532 if (!error) { 1533 for (mdp = start; mdp < stop; mdp++) { 1534 mp = *mdp; 1535 if (mp->md_type != MDT_DEPEND) 1536 continue; 1537 modname = mp->md_cval; 1538 verinfo = mp->md_data; 1539 for (nmdp = start; nmdp < stop; nmdp++) { 1540 nmp = *nmdp; 1541 if (nmp->md_type != MDT_VERSION) 1542 continue; 1543 nmodname = nmp->md_cval; 1544 if (strcmp(modname, nmodname) == 0) 1545 break; 1546 } 1547 if (nmdp < stop) /* it's a self reference */ 1548 continue; 1549 1550 /* 1551 * ok, the module isn't here yet, we 1552 * are not finished 1553 */ 1554 if (modlist_lookup2(modname, verinfo) == NULL) 1555 resolves = 0; 1556 } 1557 } 1558 /* 1559 * OK, if we found our modules, we can link. So, "provide" 1560 * the modules inside and add it to the end of the link order 1561 * list. 1562 */ 1563 if (resolves) { 1564 if (!error) { 1565 for (mdp = start; mdp < stop; mdp++) { 1566 mp = *mdp; 1567 if (mp->md_type != MDT_VERSION) 1568 continue; 1569 modname = mp->md_cval; 1570 nver = ((struct mod_version *) 1571 mp->md_data)->mv_version; 1572 if (modlist_lookup(modname, 1573 nver) != NULL) { 1574 printf("module %s already" 1575 " present!\n", modname); 1576 TAILQ_REMOVE(&loaded_files, 1577 lf, loaded); 1578 linker_file_unload(lf, 1579 LINKER_UNLOAD_FORCE); 1580 /* we changed tailq next ptr */ 1581 goto restart; 1582 } 1583 modlist_newmodule(modname, nver, lf); 1584 } 1585 } 1586 TAILQ_REMOVE(&loaded_files, lf, loaded); 1587 TAILQ_INSERT_TAIL(&depended_files, lf, loaded); 1588 /* 1589 * Since we provided modules, we need to restart the 1590 * sort so that the previous files that depend on us 1591 * have a chance. Also, we've busted the tailq next 1592 * pointer with the REMOVE. 1593 */ 1594 goto restart; 1595 } 1596 } 1597 1598 /* 1599 * At this point, we check to see what could not be resolved.. 1600 */ 1601 while ((lf = TAILQ_FIRST(&loaded_files)) != NULL) { 1602 TAILQ_REMOVE(&loaded_files, lf, loaded); 1603 printf("KLD file %s is missing dependencies\n", lf->filename); 1604 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 1605 } 1606 1607 /* 1608 * We made it. Finish off the linking in the order we determined. 1609 */ 1610 TAILQ_FOREACH_SAFE(lf, &depended_files, loaded, nlf) { 1611 if (linker_kernel_file) { 1612 linker_kernel_file->refs++; 1613 error = linker_file_add_dependency(lf, 1614 linker_kernel_file); 1615 if (error) 1616 panic("cannot add dependency"); 1617 } 1618 lf->userrefs++; /* so we can (try to) kldunload it */ 1619 error = linker_file_lookup_set(lf, MDT_SETNAME, &start, 1620 &stop, NULL); 1621 if (!error) { 1622 for (mdp = start; mdp < stop; mdp++) { 1623 mp = *mdp; 1624 if (mp->md_type != MDT_DEPEND) 1625 continue; 1626 modname = mp->md_cval; 1627 verinfo = mp->md_data; 1628 mod = modlist_lookup2(modname, verinfo); 1629 if (mod == NULL) { 1630 printf("KLD file %s - cannot find " 1631 "dependency \"%s\"\n", 1632 lf->filename, modname); 1633 goto fail; 1634 } 1635 /* Don't count self-dependencies */ 1636 if (lf == mod->container) 1637 continue; 1638 mod->container->refs++; 1639 error = linker_file_add_dependency(lf, 1640 mod->container); 1641 if (error) 1642 panic("cannot add dependency"); 1643 } 1644 } 1645 /* 1646 * Now do relocation etc using the symbol search paths 1647 * established by the dependencies 1648 */ 1649 error = LINKER_LINK_PRELOAD_FINISH(lf); 1650 if (error) { 1651 printf("KLD file %s - could not finalize loading\n", 1652 lf->filename); 1653 goto fail; 1654 } 1655 linker_file_register_modules(lf); 1656 if (linker_file_lookup_set(lf, "sysinit_set", &si_start, 1657 &si_stop, NULL) == 0) 1658 sysinit_add(si_start, si_stop); 1659 linker_file_register_sysctls(lf); 1660 lf->flags |= LINKER_FILE_LINKED; 1661 continue; 1662fail: 1663 TAILQ_REMOVE(&depended_files, lf, loaded); 1664 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 1665 } 1666 /* woohoo! we made it! */ 1667} 1668 1669SYSINIT(preload, SI_SUB_KLD, SI_ORDER_MIDDLE, linker_preload, 0); 1670 1671/* 1672 * Search for a not-loaded module by name. 1673 * 1674 * Modules may be found in the following locations: 1675 * 1676 * - preloaded (result is just the module name) - on disk (result is full path 1677 * to module) 1678 * 1679 * If the module name is qualified in any way (contains path, etc.) the we 1680 * simply return a copy of it. 1681 * 1682 * The search path can be manipulated via sysctl. Note that we use the ';' 1683 * character as a separator to be consistent with the bootloader. 1684 */ 1685 1686static char linker_hintfile[] = "linker.hints"; 1687static char linker_path[MAXPATHLEN] = "/boot/kernel;/boot/modules"; 1688 1689SYSCTL_STRING(_kern, OID_AUTO, module_path, CTLFLAG_RW, linker_path, 1690 sizeof(linker_path), "module load search path"); 1691 1692TUNABLE_STR("module_path", linker_path, sizeof(linker_path)); 1693 1694static char *linker_ext_list[] = { 1695 "", 1696 ".ko", 1697 NULL 1698}; 1699 1700/* 1701 * Check if file actually exists either with or without extension listed in 1702 * the linker_ext_list. (probably should be generic for the rest of the 1703 * kernel) 1704 */ 1705static char * 1706linker_lookup_file(const char *path, int pathlen, const char *name, 1707 int namelen, struct vattr *vap) 1708{ 1709 struct nameidata nd; 1710 struct thread *td = curthread; /* XXX */ 1711 char *result, **cpp, *sep; 1712 int error, len, extlen, reclen, flags; 1713 enum vtype type; 1714 1715 extlen = 0; 1716 for (cpp = linker_ext_list; *cpp; cpp++) { 1717 len = strlen(*cpp); 1718 if (len > extlen) 1719 extlen = len; 1720 } 1721 extlen++; /* trailing '\0' */ 1722 sep = (path[pathlen - 1] != '/') ? "/" : ""; 1723 1724 reclen = pathlen + strlen(sep) + namelen + extlen + 1; 1725 result = malloc(reclen, M_LINKER, M_WAITOK); 1726 for (cpp = linker_ext_list; *cpp; cpp++) { 1727 snprintf(result, reclen, "%.*s%s%.*s%s", pathlen, path, sep, 1728 namelen, name, *cpp); 1729 /* 1730 * Attempt to open the file, and return the path if 1731 * we succeed and it's a regular file. 1732 */ 1733 NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, result, td); 1734 flags = FREAD; 1735 error = vn_open(&nd, &flags, 0, NULL); 1736 if (error == 0) { 1737 NDFREE(&nd, NDF_ONLY_PNBUF); 1738 type = nd.ni_vp->v_type; 1739 if (vap) 1740 VOP_GETATTR(nd.ni_vp, vap, td->td_ucred); 1741 VOP_UNLOCK(nd.ni_vp, 0); 1742 vn_close(nd.ni_vp, FREAD, td->td_ucred, td); 1743 if (type == VREG) 1744 return (result); 1745 } 1746 } 1747 free(result, M_LINKER); 1748 return (NULL); 1749} 1750 1751#define INT_ALIGN(base, ptr) ptr = \ 1752 (base) + (((ptr) - (base) + sizeof(int) - 1) & ~(sizeof(int) - 1)) 1753 1754/* 1755 * Lookup KLD which contains requested module in the "linker.hints" file. If 1756 * version specification is available, then try to find the best KLD. 1757 * Otherwise just find the latest one. 1758 */ 1759static char * 1760linker_hints_lookup(const char *path, int pathlen, const char *modname, 1761 int modnamelen, struct mod_depend *verinfo) 1762{ 1763 struct thread *td = curthread; /* XXX */ 1764 struct ucred *cred = td ? td->td_ucred : NULL; 1765 struct nameidata nd; 1766 struct vattr vattr, mattr; 1767 u_char *hints = NULL; 1768 u_char *cp, *recptr, *bufend, *result, *best, *pathbuf, *sep; 1769 int error, ival, bestver, *intp, found, flags, clen, blen; 1770 ssize_t reclen; 1771 1772 result = NULL; 1773 bestver = found = 0; 1774 1775 sep = (path[pathlen - 1] != '/') ? "/" : ""; 1776 reclen = imax(modnamelen, strlen(linker_hintfile)) + pathlen + 1777 strlen(sep) + 1; 1778 pathbuf = malloc(reclen, M_LINKER, M_WAITOK); 1779 snprintf(pathbuf, reclen, "%.*s%s%s", pathlen, path, sep, 1780 linker_hintfile); 1781 1782 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, pathbuf, td); 1783 flags = FREAD; 1784 error = vn_open(&nd, &flags, 0, NULL); 1785 if (error) 1786 goto bad; 1787 NDFREE(&nd, NDF_ONLY_PNBUF); 1788 if (nd.ni_vp->v_type != VREG) 1789 goto bad; 1790 best = cp = NULL; 1791 error = VOP_GETATTR(nd.ni_vp, &vattr, cred); 1792 if (error) 1793 goto bad; 1794 /* 1795 * XXX: we need to limit this number to some reasonable value 1796 */ 1797 if (vattr.va_size > 100 * 1024) { 1798 printf("hints file too large %ld\n", (long)vattr.va_size); 1799 goto bad; 1800 } 1801 hints = malloc(vattr.va_size, M_TEMP, M_WAITOK); 1802 if (hints == NULL) 1803 goto bad; 1804 error = vn_rdwr(UIO_READ, nd.ni_vp, (caddr_t)hints, vattr.va_size, 0, 1805 UIO_SYSSPACE, IO_NODELOCKED, cred, NOCRED, &reclen, td); 1806 if (error) 1807 goto bad; 1808 VOP_UNLOCK(nd.ni_vp, 0); 1809 vn_close(nd.ni_vp, FREAD, cred, td); 1810 nd.ni_vp = NULL; 1811 if (reclen != 0) { 1812 printf("can't read %zd\n", reclen); 1813 goto bad; 1814 } 1815 intp = (int *)hints; 1816 ival = *intp++; 1817 if (ival != LINKER_HINTS_VERSION) { 1818 printf("hints file version mismatch %d\n", ival); 1819 goto bad; 1820 } 1821 bufend = hints + vattr.va_size; 1822 recptr = (u_char *)intp; 1823 clen = blen = 0; 1824 while (recptr < bufend && !found) { 1825 intp = (int *)recptr; 1826 reclen = *intp++; 1827 ival = *intp++; 1828 cp = (char *)intp; 1829 switch (ival) { 1830 case MDT_VERSION: 1831 clen = *cp++; 1832 if (clen != modnamelen || bcmp(cp, modname, clen) != 0) 1833 break; 1834 cp += clen; 1835 INT_ALIGN(hints, cp); 1836 ival = *(int *)cp; 1837 cp += sizeof(int); 1838 clen = *cp++; 1839 if (verinfo == NULL || 1840 ival == verinfo->md_ver_preferred) { 1841 found = 1; 1842 break; 1843 } 1844 if (ival >= verinfo->md_ver_minimum && 1845 ival <= verinfo->md_ver_maximum && 1846 ival > bestver) { 1847 bestver = ival; 1848 best = cp; 1849 blen = clen; 1850 } 1851 break; 1852 default: 1853 break; 1854 } 1855 recptr += reclen + sizeof(int); 1856 } 1857 /* 1858 * Finally check if KLD is in the place 1859 */ 1860 if (found) 1861 result = linker_lookup_file(path, pathlen, cp, clen, &mattr); 1862 else if (best) 1863 result = linker_lookup_file(path, pathlen, best, blen, &mattr); 1864 1865 /* 1866 * KLD is newer than hints file. What we should do now? 1867 */ 1868 if (result && timespeccmp(&mattr.va_mtime, &vattr.va_mtime, >)) 1869 printf("warning: KLD '%s' is newer than the linker.hints" 1870 " file\n", result); 1871bad: 1872 free(pathbuf, M_LINKER); 1873 if (hints) 1874 free(hints, M_TEMP); 1875 if (nd.ni_vp != NULL) { 1876 VOP_UNLOCK(nd.ni_vp, 0); 1877 vn_close(nd.ni_vp, FREAD, cred, td); 1878 } 1879 /* 1880 * If nothing found or hints is absent - fallback to the old 1881 * way by using "kldname[.ko]" as module name. 1882 */ 1883 if (!found && !bestver && result == NULL) 1884 result = linker_lookup_file(path, pathlen, modname, 1885 modnamelen, NULL); 1886 return (result); 1887} 1888 1889/* 1890 * Lookup KLD which contains requested module in the all directories. 1891 */ 1892static char * 1893linker_search_module(const char *modname, int modnamelen, 1894 struct mod_depend *verinfo) 1895{ 1896 char *cp, *ep, *result; 1897 1898 /* 1899 * traverse the linker path 1900 */ 1901 for (cp = linker_path; *cp; cp = ep + 1) { 1902 /* find the end of this component */ 1903 for (ep = cp; (*ep != 0) && (*ep != ';'); ep++); 1904 result = linker_hints_lookup(cp, ep - cp, modname, 1905 modnamelen, verinfo); 1906 if (result != NULL) 1907 return (result); 1908 if (*ep == 0) 1909 break; 1910 } 1911 return (NULL); 1912} 1913 1914/* 1915 * Search for module in all directories listed in the linker_path. 1916 */ 1917static char * 1918linker_search_kld(const char *name) 1919{ 1920 char *cp, *ep, *result; 1921 int len; 1922 1923 /* qualified at all? */ 1924 if (strchr(name, '/')) 1925 return (linker_strdup(name)); 1926 1927 /* traverse the linker path */ 1928 len = strlen(name); 1929 for (ep = linker_path; *ep; ep++) { 1930 cp = ep; 1931 /* find the end of this component */ 1932 for (; *ep != 0 && *ep != ';'; ep++); 1933 result = linker_lookup_file(cp, ep - cp, name, len, NULL); 1934 if (result != NULL) 1935 return (result); 1936 } 1937 return (NULL); 1938} 1939 1940static const char * 1941linker_basename(const char *path) 1942{ 1943 const char *filename; 1944 1945 filename = strrchr(path, '/'); 1946 if (filename == NULL) 1947 return path; 1948 if (filename[1]) 1949 filename++; 1950 return (filename); 1951} 1952 1953#ifdef HWPMC_HOOKS 1954/* 1955 * Inform hwpmc about the set of kernel modules currently loaded. 1956 */ 1957void * 1958linker_hwpmc_list_objects(void) 1959{ 1960 linker_file_t lf; 1961 struct pmckern_map_in *kobase; 1962 int i, nmappings; 1963 1964 nmappings = 0; 1965 KLD_LOCK_READ(); 1966 TAILQ_FOREACH(lf, &linker_files, link) 1967 nmappings++; 1968 1969 /* Allocate nmappings + 1 entries. */ 1970 kobase = malloc((nmappings + 1) * sizeof(struct pmckern_map_in), 1971 M_LINKER, M_WAITOK | M_ZERO); 1972 i = 0; 1973 TAILQ_FOREACH(lf, &linker_files, link) { 1974 1975 /* Save the info for this linker file. */ 1976 kobase[i].pm_file = lf->filename; 1977 kobase[i].pm_address = (uintptr_t)lf->address; 1978 i++; 1979 } 1980 KLD_UNLOCK_READ(); 1981 1982 KASSERT(i > 0, ("linker_hpwmc_list_objects: no kernel objects?")); 1983 1984 /* The last entry of the malloced area comprises of all zeros. */ 1985 KASSERT(kobase[i].pm_file == NULL, 1986 ("linker_hwpmc_list_objects: last object not NULL")); 1987 1988 return ((void *)kobase); 1989} 1990#endif 1991 1992/* 1993 * Find a file which contains given module and load it, if "parent" is not 1994 * NULL, register a reference to it. 1995 */ 1996static int 1997linker_load_module(const char *kldname, const char *modname, 1998 struct linker_file *parent, struct mod_depend *verinfo, 1999 struct linker_file **lfpp) 2000{ 2001 linker_file_t lfdep; 2002 const char *filename; 2003 char *pathname; 2004 int error; 2005 2006 KLD_LOCK_ASSERT(); 2007 if (modname == NULL) { 2008 /* 2009 * We have to load KLD 2010 */ 2011 KASSERT(verinfo == NULL, ("linker_load_module: verinfo" 2012 " is not NULL")); 2013 pathname = linker_search_kld(kldname); 2014 } else { 2015 if (modlist_lookup2(modname, verinfo) != NULL) 2016 return (EEXIST); 2017 if (kldname != NULL) 2018 pathname = linker_strdup(kldname); 2019 else if (rootvnode == NULL) 2020 pathname = NULL; 2021 else 2022 /* 2023 * Need to find a KLD with required module 2024 */ 2025 pathname = linker_search_module(modname, 2026 strlen(modname), verinfo); 2027 } 2028 if (pathname == NULL) 2029 return (ENOENT); 2030 2031 /* 2032 * Can't load more than one file with the same basename XXX: 2033 * Actually it should be possible to have multiple KLDs with 2034 * the same basename but different path because they can 2035 * provide different versions of the same modules. 2036 */ 2037 filename = linker_basename(pathname); 2038 if (linker_find_file_by_name(filename)) 2039 error = EEXIST; 2040 else do { 2041 error = linker_load_file(pathname, &lfdep); 2042 if (error) 2043 break; 2044 if (modname && verinfo && 2045 modlist_lookup2(modname, verinfo) == NULL) { 2046 linker_file_unload(lfdep, LINKER_UNLOAD_FORCE); 2047 error = ENOENT; 2048 break; 2049 } 2050 if (parent) { 2051 error = linker_file_add_dependency(parent, lfdep); 2052 if (error) 2053 break; 2054 } 2055 if (lfpp) 2056 *lfpp = lfdep; 2057 } while (0); 2058 free(pathname, M_LINKER); 2059 return (error); 2060} 2061 2062/* 2063 * This routine is responsible for finding dependencies of userland initiated 2064 * kldload(2)'s of files. 2065 */ 2066int 2067linker_load_dependencies(linker_file_t lf) 2068{ 2069 linker_file_t lfdep; 2070 struct mod_metadata **start, **stop, **mdp, **nmdp; 2071 struct mod_metadata *mp, *nmp; 2072 struct mod_depend *verinfo; 2073 modlist_t mod; 2074 const char *modname, *nmodname; 2075 int ver, error = 0, count; 2076 2077 /* 2078 * All files are dependant on /kernel. 2079 */ 2080 KLD_LOCK_ASSERT(); 2081 if (linker_kernel_file) { 2082 linker_kernel_file->refs++; 2083 error = linker_file_add_dependency(lf, linker_kernel_file); 2084 if (error) 2085 return (error); 2086 } 2087 if (linker_file_lookup_set(lf, MDT_SETNAME, &start, &stop, 2088 &count) != 0) 2089 return (0); 2090 for (mdp = start; mdp < stop; mdp++) { 2091 mp = *mdp; 2092 if (mp->md_type != MDT_VERSION) 2093 continue; 2094 modname = mp->md_cval; 2095 ver = ((struct mod_version *)mp->md_data)->mv_version; 2096 mod = modlist_lookup(modname, ver); 2097 if (mod != NULL) { 2098 printf("interface %s.%d already present in the KLD" 2099 " '%s'!\n", modname, ver, 2100 mod->container->filename); 2101 return (EEXIST); 2102 } 2103 } 2104 2105 for (mdp = start; mdp < stop; mdp++) { 2106 mp = *mdp; 2107 if (mp->md_type != MDT_DEPEND) 2108 continue; 2109 modname = mp->md_cval; 2110 verinfo = mp->md_data; 2111 nmodname = NULL; 2112 for (nmdp = start; nmdp < stop; nmdp++) { 2113 nmp = *nmdp; 2114 if (nmp->md_type != MDT_VERSION) 2115 continue; 2116 nmodname = nmp->md_cval; 2117 if (strcmp(modname, nmodname) == 0) 2118 break; 2119 } 2120 if (nmdp < stop)/* early exit, it's a self reference */ 2121 continue; 2122 mod = modlist_lookup2(modname, verinfo); 2123 if (mod) { /* woohoo, it's loaded already */ 2124 lfdep = mod->container; 2125 lfdep->refs++; 2126 error = linker_file_add_dependency(lf, lfdep); 2127 if (error) 2128 break; 2129 continue; 2130 } 2131 error = linker_load_module(NULL, modname, lf, verinfo, NULL); 2132 if (error) { 2133 printf("KLD %s: depends on %s - not available or" 2134 " version mismatch\n", lf->filename, modname); 2135 break; 2136 } 2137 } 2138 2139 if (error) 2140 return (error); 2141 linker_addmodules(lf, start, stop, 0); 2142 return (error); 2143} 2144 2145static int 2146sysctl_kern_function_list_iterate(const char *name, void *opaque) 2147{ 2148 struct sysctl_req *req; 2149 2150 req = opaque; 2151 return (SYSCTL_OUT(req, name, strlen(name) + 1)); 2152} 2153 2154/* 2155 * Export a nul-separated, double-nul-terminated list of all function names 2156 * in the kernel. 2157 */ 2158static int 2159sysctl_kern_function_list(SYSCTL_HANDLER_ARGS) 2160{ 2161 linker_file_t lf; 2162 int error; 2163 2164#ifdef MAC 2165 error = mac_kld_check_stat(req->td->td_ucred); 2166 if (error) 2167 return (error); 2168#endif 2169 error = sysctl_wire_old_buffer(req, 0); 2170 if (error != 0) 2171 return (error); 2172 KLD_LOCK(); 2173 TAILQ_FOREACH(lf, &linker_files, link) { 2174 error = LINKER_EACH_FUNCTION_NAME(lf, 2175 sysctl_kern_function_list_iterate, req); 2176 if (error) { 2177 KLD_UNLOCK(); 2178 return (error); 2179 } 2180 } 2181 KLD_UNLOCK(); 2182 return (SYSCTL_OUT(req, "", 1)); 2183} 2184 2185SYSCTL_PROC(_kern, OID_AUTO, function_list, CTLTYPE_OPAQUE | CTLFLAG_RD, 2186 NULL, 0, sysctl_kern_function_list, "", "kernel function list"); 2187