kern_linker.c revision 284153
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 284153 2015-06-08 14:06:47Z jhb $"); 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_RWTUN, 70 &kld_debug, 0, "Set various levels of KLD debug"); 71#endif 72 73/* 74 * static char *linker_search_path(const char *name, struct mod_depend 75 * *verinfo); 76 */ 77static const char *linker_basename(const char *path); 78 79/* 80 * Find a currently loaded file given its filename. 81 */ 82static linker_file_t linker_find_file_by_name(const char* _filename); 83 84/* 85 * Find a currently loaded file given its file id. 86 */ 87static linker_file_t linker_find_file_by_id(int _fileid); 88 89/* Metadata from the static kernel */ 90SET_DECLARE(modmetadata_set, struct mod_metadata); 91 92MALLOC_DEFINE(M_LINKER, "linker", "kernel linker"); 93 94linker_file_t linker_kernel_file; 95 96static struct sx kld_sx; /* kernel linker lock */ 97 98/* 99 * Load counter used by clients to determine if a linker file has been 100 * re-loaded. This counter is incremented for each file load. 101 */ 102static int loadcnt; 103 104static linker_class_list_t classes; 105static linker_file_list_t linker_files; 106static int next_file_id = 1; 107static int linker_no_more_classes = 0; 108 109#define LINKER_GET_NEXT_FILE_ID(a) do { \ 110 linker_file_t lftmp; \ 111 \ 112 if (!cold) \ 113 sx_assert(&kld_sx, SA_XLOCKED); \ 114retry: \ 115 TAILQ_FOREACH(lftmp, &linker_files, link) { \ 116 if (next_file_id == lftmp->id) { \ 117 next_file_id++; \ 118 goto retry; \ 119 } \ 120 } \ 121 (a) = next_file_id; \ 122} while(0) 123 124 125/* XXX wrong name; we're looking at version provision tags here, not modules */ 126typedef TAILQ_HEAD(, modlist) modlisthead_t; 127struct modlist { 128 TAILQ_ENTRY(modlist) link; /* chain together all modules */ 129 linker_file_t container; 130 const char *name; 131 int version; 132}; 133typedef struct modlist *modlist_t; 134static modlisthead_t found_modules; 135 136static int linker_file_add_dependency(linker_file_t file, 137 linker_file_t dep); 138static caddr_t linker_file_lookup_symbol_internal(linker_file_t file, 139 const char* name, int deps); 140static int linker_file_lookup_set_locked(linker_file_t file, 141 const char *name, void *firstp, void *lastp, int *countp); 142static int linker_load_module(const char *kldname, 143 const char *modname, struct linker_file *parent, 144 const struct mod_depend *verinfo, struct linker_file **lfpp); 145static modlist_t modlist_lookup2(const char *name, const struct mod_depend *verinfo); 146 147static void 148linker_init(void *arg) 149{ 150 151 sx_init(&kld_sx, "kernel linker"); 152 TAILQ_INIT(&classes); 153 TAILQ_INIT(&linker_files); 154} 155 156SYSINIT(linker, SI_SUB_KLD, SI_ORDER_FIRST, linker_init, 0); 157 158static void 159linker_stop_class_add(void *arg) 160{ 161 162 linker_no_more_classes = 1; 163} 164 165SYSINIT(linker_class, SI_SUB_KLD, SI_ORDER_ANY, linker_stop_class_add, NULL); 166 167int 168linker_add_class(linker_class_t lc) 169{ 170 171 /* 172 * We disallow any class registration past SI_ORDER_ANY 173 * of SI_SUB_KLD. We bump the reference count to keep the 174 * ops from being freed. 175 */ 176 if (linker_no_more_classes == 1) 177 return (EPERM); 178 kobj_class_compile((kobj_class_t) lc); 179 ((kobj_class_t)lc)->refs++; /* XXX: kobj_mtx */ 180 TAILQ_INSERT_TAIL(&classes, lc, link); 181 return (0); 182} 183 184static void 185linker_file_sysinit(linker_file_t lf) 186{ 187 struct sysinit **start, **stop, **sipp, **xipp, *save; 188 189 KLD_DPF(FILE, ("linker_file_sysinit: calling SYSINITs for %s\n", 190 lf->filename)); 191 192 sx_assert(&kld_sx, SA_XLOCKED); 193 194 if (linker_file_lookup_set_locked(lf, "sysinit_set", &start, &stop, 195 NULL) != 0) 196 return; 197 /* 198 * Perform a bubble sort of the system initialization objects by 199 * their subsystem (primary key) and order (secondary key). 200 * 201 * Since some things care about execution order, this is the operation 202 * which ensures continued function. 203 */ 204 for (sipp = start; sipp < stop; sipp++) { 205 for (xipp = sipp + 1; xipp < stop; xipp++) { 206 if ((*sipp)->subsystem < (*xipp)->subsystem || 207 ((*sipp)->subsystem == (*xipp)->subsystem && 208 (*sipp)->order <= (*xipp)->order)) 209 continue; /* skip */ 210 save = *sipp; 211 *sipp = *xipp; 212 *xipp = save; 213 } 214 } 215 216 /* 217 * Traverse the (now) ordered list of system initialization tasks. 218 * Perform each task, and continue on to the next task. 219 */ 220 sx_xunlock(&kld_sx); 221 mtx_lock(&Giant); 222 for (sipp = start; sipp < stop; sipp++) { 223 if ((*sipp)->subsystem == SI_SUB_DUMMY) 224 continue; /* skip dummy task(s) */ 225 226 /* Call function */ 227 (*((*sipp)->func)) ((*sipp)->udata); 228 } 229 mtx_unlock(&Giant); 230 sx_xlock(&kld_sx); 231} 232 233static void 234linker_file_sysuninit(linker_file_t lf) 235{ 236 struct sysinit **start, **stop, **sipp, **xipp, *save; 237 238 KLD_DPF(FILE, ("linker_file_sysuninit: calling SYSUNINITs for %s\n", 239 lf->filename)); 240 241 sx_assert(&kld_sx, SA_XLOCKED); 242 243 if (linker_file_lookup_set_locked(lf, "sysuninit_set", &start, &stop, 244 NULL) != 0) 245 return; 246 247 /* 248 * Perform a reverse bubble sort of the system initialization objects 249 * by their subsystem (primary key) and order (secondary key). 250 * 251 * Since some things care about execution order, this is the operation 252 * which ensures continued function. 253 */ 254 for (sipp = start; sipp < stop; sipp++) { 255 for (xipp = sipp + 1; xipp < stop; xipp++) { 256 if ((*sipp)->subsystem > (*xipp)->subsystem || 257 ((*sipp)->subsystem == (*xipp)->subsystem && 258 (*sipp)->order >= (*xipp)->order)) 259 continue; /* skip */ 260 save = *sipp; 261 *sipp = *xipp; 262 *xipp = save; 263 } 264 } 265 266 /* 267 * Traverse the (now) ordered list of system initialization tasks. 268 * Perform each task, and continue on to the next task. 269 */ 270 sx_xunlock(&kld_sx); 271 mtx_lock(&Giant); 272 for (sipp = start; sipp < stop; sipp++) { 273 if ((*sipp)->subsystem == SI_SUB_DUMMY) 274 continue; /* skip dummy task(s) */ 275 276 /* Call function */ 277 (*((*sipp)->func)) ((*sipp)->udata); 278 } 279 mtx_unlock(&Giant); 280 sx_xlock(&kld_sx); 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 sx_assert(&kld_sx, SA_XLOCKED); 293 294 if (linker_file_lookup_set_locked(lf, "sysctl_set", &start, &stop, 295 NULL) != 0) 296 return; 297 298 sx_xunlock(&kld_sx); 299 sysctl_xlock(); 300 for (oidp = start; oidp < stop; oidp++) 301 sysctl_register_oid(*oidp); 302 sysctl_xunlock(); 303 sx_xlock(&kld_sx); 304} 305 306static void 307linker_file_unregister_sysctls(linker_file_t lf) 308{ 309 struct sysctl_oid **start, **stop, **oidp; 310 311 KLD_DPF(FILE, ("linker_file_unregister_sysctls: unregistering SYSCTLs" 312 " for %s\n", lf->filename)); 313 314 sx_assert(&kld_sx, SA_XLOCKED); 315 316 if (linker_file_lookup_set_locked(lf, "sysctl_set", &start, &stop, 317 NULL) != 0) 318 return; 319 320 sx_xunlock(&kld_sx); 321 sysctl_xlock(); 322 for (oidp = start; oidp < stop; oidp++) 323 sysctl_unregister_oid(*oidp); 324 sysctl_xunlock(); 325 sx_xlock(&kld_sx); 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 sx_assert(&kld_sx, SA_XLOCKED); 339 340 if (linker_file_lookup_set_locked(lf, "modmetadata_set", &start, 341 &stop, NULL) != 0) { 342 /* 343 * This fallback should be unnecessary, but if we get booted 344 * from boot2 instead of loader and we are missing our 345 * metadata then we have to try the best we can. 346 */ 347 if (lf == linker_kernel_file) { 348 start = SET_BEGIN(modmetadata_set); 349 stop = SET_LIMIT(modmetadata_set); 350 } else 351 return (0); 352 } 353 first_error = 0; 354 for (mdp = start; mdp < stop; mdp++) { 355 if ((*mdp)->md_type != MDT_MODULE) 356 continue; 357 moddata = (*mdp)->md_data; 358 KLD_DPF(FILE, ("Registering module %s in %s\n", 359 moddata->name, lf->filename)); 360 error = module_register(moddata, lf); 361 if (error) { 362 printf("Module %s failed to register: %d\n", 363 moddata->name, error); 364 if (first_error == 0) 365 first_error = error; 366 } 367 } 368 return (first_error); 369} 370 371static void 372linker_init_kernel_modules(void) 373{ 374 375 sx_xlock(&kld_sx); 376 linker_file_register_modules(linker_kernel_file); 377 sx_xunlock(&kld_sx); 378} 379 380SYSINIT(linker_kernel, SI_SUB_KLD, SI_ORDER_ANY, linker_init_kernel_modules, 381 0); 382 383static int 384linker_load_file(const char *filename, linker_file_t *result) 385{ 386 linker_class_t lc; 387 linker_file_t lf; 388 int foundfile, error, modules; 389 390 /* Refuse to load modules if securelevel raised */ 391 if (prison0.pr_securelevel > 0) 392 return (EPERM); 393 394 sx_assert(&kld_sx, SA_XLOCKED); 395 lf = linker_find_file_by_name(filename); 396 if (lf) { 397 KLD_DPF(FILE, ("linker_load_file: file %s is already loaded," 398 " incrementing refs\n", filename)); 399 *result = lf; 400 lf->refs++; 401 return (0); 402 } 403 foundfile = 0; 404 error = 0; 405 406 /* 407 * We do not need to protect (lock) classes here because there is 408 * no class registration past startup (SI_SUB_KLD, SI_ORDER_ANY) 409 * and there is no class deregistration mechanism at this time. 410 */ 411 TAILQ_FOREACH(lc, &classes, link) { 412 KLD_DPF(FILE, ("linker_load_file: trying to load %s\n", 413 filename)); 414 error = LINKER_LOAD_FILE(lc, filename, &lf); 415 /* 416 * If we got something other than ENOENT, then it exists but 417 * we cannot load it for some other reason. 418 */ 419 if (error != ENOENT) 420 foundfile = 1; 421 if (lf) { 422 error = linker_file_register_modules(lf); 423 if (error == EEXIST) { 424 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 425 return (error); 426 } 427 modules = !TAILQ_EMPTY(&lf->modules); 428 linker_file_register_sysctls(lf); 429 linker_file_sysinit(lf); 430 lf->flags |= LINKER_FILE_LINKED; 431 432 /* 433 * If all of the modules in this file failed 434 * to load, unload the file and return an 435 * error of ENOEXEC. 436 */ 437 if (modules && TAILQ_EMPTY(&lf->modules)) { 438 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 439 return (ENOEXEC); 440 } 441 EVENTHANDLER_INVOKE(kld_load, lf); 442 *result = lf; 443 return (0); 444 } 445 } 446 /* 447 * Less than ideal, but tells the user whether it failed to load or 448 * the module was not found. 449 */ 450 if (foundfile) { 451 452 /* 453 * If the file type has not been recognized by the last try 454 * printout a message before to fail. 455 */ 456 if (error == ENOSYS) 457 printf("linker_load_file: Unsupported file type\n"); 458 459 /* 460 * Format not recognized or otherwise unloadable. 461 * When loading a module that is statically built into 462 * the kernel EEXIST percolates back up as the return 463 * value. Preserve this so that apps like sysinstall 464 * can recognize this special case and not post bogus 465 * dialog boxes. 466 */ 467 if (error != EEXIST) 468 error = ENOEXEC; 469 } else 470 error = ENOENT; /* Nothing found */ 471 return (error); 472} 473 474int 475linker_reference_module(const char *modname, struct mod_depend *verinfo, 476 linker_file_t *result) 477{ 478 modlist_t mod; 479 int error; 480 481 sx_xlock(&kld_sx); 482 if ((mod = modlist_lookup2(modname, verinfo)) != NULL) { 483 *result = mod->container; 484 (*result)->refs++; 485 sx_xunlock(&kld_sx); 486 return (0); 487 } 488 489 error = linker_load_module(NULL, modname, NULL, verinfo, result); 490 sx_xunlock(&kld_sx); 491 return (error); 492} 493 494int 495linker_release_module(const char *modname, struct mod_depend *verinfo, 496 linker_file_t lf) 497{ 498 modlist_t mod; 499 int error; 500 501 sx_xlock(&kld_sx); 502 if (lf == NULL) { 503 KASSERT(modname != NULL, 504 ("linker_release_module: no file or name")); 505 mod = modlist_lookup2(modname, verinfo); 506 if (mod == NULL) { 507 sx_xunlock(&kld_sx); 508 return (ESRCH); 509 } 510 lf = mod->container; 511 } else 512 KASSERT(modname == NULL && verinfo == NULL, 513 ("linker_release_module: both file and name")); 514 error = linker_file_unload(lf, LINKER_UNLOAD_NORMAL); 515 sx_xunlock(&kld_sx); 516 return (error); 517} 518 519static linker_file_t 520linker_find_file_by_name(const char *filename) 521{ 522 linker_file_t lf; 523 char *koname; 524 525 koname = malloc(strlen(filename) + 4, M_LINKER, M_WAITOK); 526 sprintf(koname, "%s.ko", filename); 527 528 sx_assert(&kld_sx, SA_XLOCKED); 529 TAILQ_FOREACH(lf, &linker_files, link) { 530 if (strcmp(lf->filename, koname) == 0) 531 break; 532 if (strcmp(lf->filename, filename) == 0) 533 break; 534 } 535 free(koname, M_LINKER); 536 return (lf); 537} 538 539static linker_file_t 540linker_find_file_by_id(int fileid) 541{ 542 linker_file_t lf; 543 544 sx_assert(&kld_sx, SA_XLOCKED); 545 TAILQ_FOREACH(lf, &linker_files, link) 546 if (lf->id == fileid && lf->flags & LINKER_FILE_LINKED) 547 break; 548 return (lf); 549} 550 551int 552linker_file_foreach(linker_predicate_t *predicate, void *context) 553{ 554 linker_file_t lf; 555 int retval = 0; 556 557 sx_xlock(&kld_sx); 558 TAILQ_FOREACH(lf, &linker_files, link) { 559 retval = predicate(lf, context); 560 if (retval != 0) 561 break; 562 } 563 sx_xunlock(&kld_sx); 564 return (retval); 565} 566 567linker_file_t 568linker_make_file(const char *pathname, linker_class_t lc) 569{ 570 linker_file_t lf; 571 const char *filename; 572 573 if (!cold) 574 sx_assert(&kld_sx, SA_XLOCKED); 575 filename = linker_basename(pathname); 576 577 KLD_DPF(FILE, ("linker_make_file: new file, filename='%s' for pathname='%s'\n", filename, pathname)); 578 lf = (linker_file_t)kobj_create((kobj_class_t)lc, M_LINKER, M_WAITOK); 579 if (lf == NULL) 580 return (NULL); 581 lf->ctors_addr = 0; 582 lf->ctors_size = 0; 583 lf->refs = 1; 584 lf->userrefs = 0; 585 lf->flags = 0; 586 lf->filename = strdup(filename, M_LINKER); 587 lf->pathname = strdup(pathname, M_LINKER); 588 LINKER_GET_NEXT_FILE_ID(lf->id); 589 lf->ndeps = 0; 590 lf->deps = NULL; 591 lf->loadcnt = ++loadcnt; 592 STAILQ_INIT(&lf->common); 593 TAILQ_INIT(&lf->modules); 594 TAILQ_INSERT_TAIL(&linker_files, lf, link); 595 return (lf); 596} 597 598int 599linker_file_unload(linker_file_t file, int flags) 600{ 601 module_t mod, next; 602 modlist_t ml, nextml; 603 struct common_symbol *cp; 604 int error, i; 605 606 /* Refuse to unload modules if securelevel raised. */ 607 if (prison0.pr_securelevel > 0) 608 return (EPERM); 609 610 sx_assert(&kld_sx, SA_XLOCKED); 611 KLD_DPF(FILE, ("linker_file_unload: lf->refs=%d\n", file->refs)); 612 613 /* Easy case of just dropping a reference. */ 614 if (file->refs > 1) { 615 file->refs--; 616 return (0); 617 } 618 619 /* Give eventhandlers a chance to prevent the unload. */ 620 error = 0; 621 EVENTHANDLER_INVOKE(kld_unload_try, file, &error); 622 if (error != 0) 623 return (EBUSY); 624 625 KLD_DPF(FILE, ("linker_file_unload: file is unloading," 626 " informing modules\n")); 627 628 /* 629 * Quiesce all the modules to give them a chance to veto the unload. 630 */ 631 MOD_SLOCK; 632 for (mod = TAILQ_FIRST(&file->modules); mod; 633 mod = module_getfnext(mod)) { 634 635 error = module_quiesce(mod); 636 if (error != 0 && flags != LINKER_UNLOAD_FORCE) { 637 KLD_DPF(FILE, ("linker_file_unload: module %s" 638 " vetoed unload\n", module_getname(mod))); 639 /* 640 * XXX: Do we need to tell all the quiesced modules 641 * that they can resume work now via a new module 642 * event? 643 */ 644 MOD_SUNLOCK; 645 return (error); 646 } 647 } 648 MOD_SUNLOCK; 649 650 /* 651 * Inform any modules associated with this file that they are 652 * being unloaded. 653 */ 654 MOD_XLOCK; 655 for (mod = TAILQ_FIRST(&file->modules); mod; mod = next) { 656 next = module_getfnext(mod); 657 MOD_XUNLOCK; 658 659 /* 660 * Give the module a chance to veto the unload. 661 */ 662 if ((error = module_unload(mod)) != 0) { 663#ifdef KLD_DEBUG 664 MOD_SLOCK; 665 KLD_DPF(FILE, ("linker_file_unload: module %s" 666 " failed unload\n", module_getname(mod))); 667 MOD_SUNLOCK; 668#endif 669 return (error); 670 } 671 MOD_XLOCK; 672 module_release(mod); 673 } 674 MOD_XUNLOCK; 675 676 TAILQ_FOREACH_SAFE(ml, &found_modules, link, nextml) { 677 if (ml->container == file) { 678 TAILQ_REMOVE(&found_modules, ml, link); 679 free(ml, M_LINKER); 680 } 681 } 682 683 /* 684 * Don't try to run SYSUNINITs if we are unloaded due to a 685 * link error. 686 */ 687 if (file->flags & LINKER_FILE_LINKED) { 688 file->flags &= ~LINKER_FILE_LINKED; 689 linker_file_sysuninit(file); 690 linker_file_unregister_sysctls(file); 691 } 692 TAILQ_REMOVE(&linker_files, file, link); 693 694 if (file->deps) { 695 for (i = 0; i < file->ndeps; i++) 696 linker_file_unload(file->deps[i], flags); 697 free(file->deps, M_LINKER); 698 file->deps = NULL; 699 } 700 while ((cp = STAILQ_FIRST(&file->common)) != NULL) { 701 STAILQ_REMOVE_HEAD(&file->common, link); 702 free(cp, M_LINKER); 703 } 704 705 LINKER_UNLOAD(file); 706 707 EVENTHANDLER_INVOKE(kld_unload, file->filename, file->address, 708 file->size); 709 710 if (file->filename) { 711 free(file->filename, M_LINKER); 712 file->filename = NULL; 713 } 714 if (file->pathname) { 715 free(file->pathname, M_LINKER); 716 file->pathname = NULL; 717 } 718 kobj_delete((kobj_t) file, M_LINKER); 719 return (0); 720} 721 722int 723linker_ctf_get(linker_file_t file, linker_ctf_t *lc) 724{ 725 return (LINKER_CTF_GET(file, lc)); 726} 727 728static int 729linker_file_add_dependency(linker_file_t file, linker_file_t dep) 730{ 731 linker_file_t *newdeps; 732 733 sx_assert(&kld_sx, SA_XLOCKED); 734 file->deps = realloc(file->deps, (file->ndeps + 1) * sizeof(*newdeps), 735 M_LINKER, M_WAITOK | M_ZERO); 736 file->deps[file->ndeps] = dep; 737 file->ndeps++; 738 KLD_DPF(FILE, ("linker_file_add_dependency:" 739 " adding %s as dependency for %s\n", 740 dep->filename, file->filename)); 741 return (0); 742} 743 744/* 745 * Locate a linker set and its contents. This is a helper function to avoid 746 * linker_if.h exposure elsewhere. Note: firstp and lastp are really void **. 747 * This function is used in this file so we can avoid having lots of (void **) 748 * casts. 749 */ 750static int 751linker_file_lookup_set_locked(linker_file_t file, const char *name, 752 void *firstp, void *lastp, int *countp) 753{ 754 755 sx_assert(&kld_sx, SA_LOCKED); 756 return (LINKER_LOOKUP_SET(file, name, firstp, lastp, countp)); 757} 758 759int 760linker_file_lookup_set(linker_file_t file, const char *name, 761 void *firstp, void *lastp, int *countp) 762{ 763 int error; 764 765 sx_slock(&kld_sx); 766 error = linker_file_lookup_set_locked(file, name, firstp, lastp, 767 countp); 768 sx_sunlock(&kld_sx); 769 return (error); 770} 771 772/* 773 * List all functions in a file. 774 */ 775int 776linker_file_function_listall(linker_file_t lf, 777 linker_function_nameval_callback_t callback_func, void *arg) 778{ 779 return (LINKER_EACH_FUNCTION_NAMEVAL(lf, callback_func, arg)); 780} 781 782caddr_t 783linker_file_lookup_symbol(linker_file_t file, const char *name, int deps) 784{ 785 caddr_t sym; 786 int locked; 787 788 locked = sx_xlocked(&kld_sx); 789 if (!locked) 790 sx_xlock(&kld_sx); 791 sym = linker_file_lookup_symbol_internal(file, name, deps); 792 if (!locked) 793 sx_xunlock(&kld_sx); 794 return (sym); 795} 796 797static caddr_t 798linker_file_lookup_symbol_internal(linker_file_t file, const char *name, 799 int deps) 800{ 801 c_linker_sym_t sym; 802 linker_symval_t symval; 803 caddr_t address; 804 size_t common_size = 0; 805 int i; 806 807 sx_assert(&kld_sx, SA_XLOCKED); 808 KLD_DPF(SYM, ("linker_file_lookup_symbol: file=%p, name=%s, deps=%d\n", 809 file, name, deps)); 810 811 if (LINKER_LOOKUP_SYMBOL(file, name, &sym) == 0) { 812 LINKER_SYMBOL_VALUES(file, sym, &symval); 813 if (symval.value == 0) 814 /* 815 * For commons, first look them up in the 816 * dependencies and only allocate space if not found 817 * there. 818 */ 819 common_size = symval.size; 820 else { 821 KLD_DPF(SYM, ("linker_file_lookup_symbol: symbol" 822 ".value=%p\n", symval.value)); 823 return (symval.value); 824 } 825 } 826 if (deps) { 827 for (i = 0; i < file->ndeps; i++) { 828 address = linker_file_lookup_symbol_internal( 829 file->deps[i], name, 0); 830 if (address) { 831 KLD_DPF(SYM, ("linker_file_lookup_symbol:" 832 " deps value=%p\n", address)); 833 return (address); 834 } 835 } 836 } 837 if (common_size > 0) { 838 /* 839 * This is a common symbol which was not found in the 840 * dependencies. We maintain a simple common symbol table in 841 * the file object. 842 */ 843 struct common_symbol *cp; 844 845 STAILQ_FOREACH(cp, &file->common, link) { 846 if (strcmp(cp->name, name) == 0) { 847 KLD_DPF(SYM, ("linker_file_lookup_symbol:" 848 " old common value=%p\n", cp->address)); 849 return (cp->address); 850 } 851 } 852 /* 853 * Round the symbol size up to align. 854 */ 855 common_size = (common_size + sizeof(int) - 1) & -sizeof(int); 856 cp = malloc(sizeof(struct common_symbol) 857 + common_size + strlen(name) + 1, M_LINKER, 858 M_WAITOK | M_ZERO); 859 cp->address = (caddr_t)(cp + 1); 860 cp->name = cp->address + common_size; 861 strcpy(cp->name, name); 862 bzero(cp->address, common_size); 863 STAILQ_INSERT_TAIL(&file->common, cp, link); 864 865 KLD_DPF(SYM, ("linker_file_lookup_symbol: new common" 866 " value=%p\n", cp->address)); 867 return (cp->address); 868 } 869 KLD_DPF(SYM, ("linker_file_lookup_symbol: fail\n")); 870 return (0); 871} 872 873/* 874 * Both DDB and stack(9) rely on the kernel linker to provide forward and 875 * backward lookup of symbols. However, DDB and sometimes stack(9) need to 876 * do this in a lockfree manner. We provide a set of internal helper 877 * routines to perform these operations without locks, and then wrappers that 878 * optionally lock. 879 * 880 * linker_debug_lookup() is ifdef DDB as currently it's only used by DDB. 881 */ 882#ifdef DDB 883static int 884linker_debug_lookup(const char *symstr, c_linker_sym_t *sym) 885{ 886 linker_file_t lf; 887 888 TAILQ_FOREACH(lf, &linker_files, link) { 889 if (LINKER_LOOKUP_SYMBOL(lf, symstr, sym) == 0) 890 return (0); 891 } 892 return (ENOENT); 893} 894#endif 895 896static int 897linker_debug_search_symbol(caddr_t value, c_linker_sym_t *sym, long *diffp) 898{ 899 linker_file_t lf; 900 c_linker_sym_t best, es; 901 u_long diff, bestdiff, off; 902 903 best = 0; 904 off = (uintptr_t)value; 905 bestdiff = off; 906 TAILQ_FOREACH(lf, &linker_files, link) { 907 if (LINKER_SEARCH_SYMBOL(lf, value, &es, &diff) != 0) 908 continue; 909 if (es != 0 && diff < bestdiff) { 910 best = es; 911 bestdiff = diff; 912 } 913 if (bestdiff == 0) 914 break; 915 } 916 if (best) { 917 *sym = best; 918 *diffp = bestdiff; 919 return (0); 920 } else { 921 *sym = 0; 922 *diffp = off; 923 return (ENOENT); 924 } 925} 926 927static int 928linker_debug_symbol_values(c_linker_sym_t sym, linker_symval_t *symval) 929{ 930 linker_file_t lf; 931 932 TAILQ_FOREACH(lf, &linker_files, link) { 933 if (LINKER_SYMBOL_VALUES(lf, sym, symval) == 0) 934 return (0); 935 } 936 return (ENOENT); 937} 938 939static int 940linker_debug_search_symbol_name(caddr_t value, char *buf, u_int buflen, 941 long *offset) 942{ 943 linker_symval_t symval; 944 c_linker_sym_t sym; 945 int error; 946 947 *offset = 0; 948 error = linker_debug_search_symbol(value, &sym, offset); 949 if (error) 950 return (error); 951 error = linker_debug_symbol_values(sym, &symval); 952 if (error) 953 return (error); 954 strlcpy(buf, symval.name, buflen); 955 return (0); 956} 957 958/* 959 * DDB Helpers. DDB has to look across multiple files with their own symbol 960 * tables and string tables. 961 * 962 * Note that we do not obey list locking protocols here. We really don't need 963 * DDB to hang because somebody's got the lock held. We'll take the chance 964 * that the files list is inconsistant instead. 965 */ 966#ifdef DDB 967int 968linker_ddb_lookup(const char *symstr, c_linker_sym_t *sym) 969{ 970 971 return (linker_debug_lookup(symstr, sym)); 972} 973#endif 974 975int 976linker_ddb_search_symbol(caddr_t value, c_linker_sym_t *sym, long *diffp) 977{ 978 979 return (linker_debug_search_symbol(value, sym, diffp)); 980} 981 982int 983linker_ddb_symbol_values(c_linker_sym_t sym, linker_symval_t *symval) 984{ 985 986 return (linker_debug_symbol_values(sym, symval)); 987} 988 989int 990linker_ddb_search_symbol_name(caddr_t value, char *buf, u_int buflen, 991 long *offset) 992{ 993 994 return (linker_debug_search_symbol_name(value, buf, buflen, offset)); 995} 996 997/* 998 * stack(9) helper for non-debugging environemnts. Unlike DDB helpers, we do 999 * obey locking protocols, and offer a significantly less complex interface. 1000 */ 1001int 1002linker_search_symbol_name(caddr_t value, char *buf, u_int buflen, 1003 long *offset) 1004{ 1005 int error; 1006 1007 sx_slock(&kld_sx); 1008 error = linker_debug_search_symbol_name(value, buf, buflen, offset); 1009 sx_sunlock(&kld_sx); 1010 return (error); 1011} 1012 1013/* 1014 * Syscalls. 1015 */ 1016int 1017kern_kldload(struct thread *td, const char *file, int *fileid) 1018{ 1019 const char *kldname, *modname; 1020 linker_file_t lf; 1021 int error; 1022 1023 if ((error = securelevel_gt(td->td_ucred, 0)) != 0) 1024 return (error); 1025 1026 if ((error = priv_check(td, PRIV_KLD_LOAD)) != 0) 1027 return (error); 1028 1029 /* 1030 * It is possible that kldloaded module will attach a new ifnet, 1031 * so vnet context must be set when this ocurs. 1032 */ 1033 CURVNET_SET(TD_TO_VNET(td)); 1034 1035 /* 1036 * If file does not contain a qualified name or any dot in it 1037 * (kldname.ko, or kldname.ver.ko) treat it as an interface 1038 * name. 1039 */ 1040 if (strchr(file, '/') || strchr(file, '.')) { 1041 kldname = file; 1042 modname = NULL; 1043 } else { 1044 kldname = NULL; 1045 modname = file; 1046 } 1047 1048 sx_xlock(&kld_sx); 1049 error = linker_load_module(kldname, modname, NULL, NULL, &lf); 1050 if (error) { 1051 sx_xunlock(&kld_sx); 1052 goto done; 1053 } 1054 lf->userrefs++; 1055 if (fileid != NULL) 1056 *fileid = lf->id; 1057 sx_xunlock(&kld_sx); 1058 1059done: 1060 CURVNET_RESTORE(); 1061 return (error); 1062} 1063 1064int 1065sys_kldload(struct thread *td, struct kldload_args *uap) 1066{ 1067 char *pathname = NULL; 1068 int error, fileid; 1069 1070 td->td_retval[0] = -1; 1071 1072 pathname = malloc(MAXPATHLEN, M_TEMP, M_WAITOK); 1073 error = copyinstr(uap->file, pathname, MAXPATHLEN, NULL); 1074 if (error == 0) { 1075 error = kern_kldload(td, pathname, &fileid); 1076 if (error == 0) 1077 td->td_retval[0] = fileid; 1078 } 1079 free(pathname, M_TEMP); 1080 return (error); 1081} 1082 1083int 1084kern_kldunload(struct thread *td, int fileid, int flags) 1085{ 1086 linker_file_t lf; 1087 int error = 0; 1088 1089 if ((error = securelevel_gt(td->td_ucred, 0)) != 0) 1090 return (error); 1091 1092 if ((error = priv_check(td, PRIV_KLD_UNLOAD)) != 0) 1093 return (error); 1094 1095 CURVNET_SET(TD_TO_VNET(td)); 1096 sx_xlock(&kld_sx); 1097 lf = linker_find_file_by_id(fileid); 1098 if (lf) { 1099 KLD_DPF(FILE, ("kldunload: lf->userrefs=%d\n", lf->userrefs)); 1100 1101 if (lf->userrefs == 0) { 1102 /* 1103 * XXX: maybe LINKER_UNLOAD_FORCE should override ? 1104 */ 1105 printf("kldunload: attempt to unload file that was" 1106 " loaded by the kernel\n"); 1107 error = EBUSY; 1108 } else { 1109 lf->userrefs--; 1110 error = linker_file_unload(lf, flags); 1111 if (error) 1112 lf->userrefs++; 1113 } 1114 } else 1115 error = ENOENT; 1116 sx_xunlock(&kld_sx); 1117 1118 CURVNET_RESTORE(); 1119 return (error); 1120} 1121 1122int 1123sys_kldunload(struct thread *td, struct kldunload_args *uap) 1124{ 1125 1126 return (kern_kldunload(td, uap->fileid, LINKER_UNLOAD_NORMAL)); 1127} 1128 1129int 1130sys_kldunloadf(struct thread *td, struct kldunloadf_args *uap) 1131{ 1132 1133 if (uap->flags != LINKER_UNLOAD_NORMAL && 1134 uap->flags != LINKER_UNLOAD_FORCE) 1135 return (EINVAL); 1136 return (kern_kldunload(td, uap->fileid, uap->flags)); 1137} 1138 1139int 1140sys_kldfind(struct thread *td, struct kldfind_args *uap) 1141{ 1142 char *pathname; 1143 const char *filename; 1144 linker_file_t lf; 1145 int error; 1146 1147#ifdef MAC 1148 error = mac_kld_check_stat(td->td_ucred); 1149 if (error) 1150 return (error); 1151#endif 1152 1153 td->td_retval[0] = -1; 1154 1155 pathname = malloc(MAXPATHLEN, M_TEMP, M_WAITOK); 1156 if ((error = copyinstr(uap->file, pathname, MAXPATHLEN, NULL)) != 0) 1157 goto out; 1158 1159 filename = linker_basename(pathname); 1160 sx_xlock(&kld_sx); 1161 lf = linker_find_file_by_name(filename); 1162 if (lf) 1163 td->td_retval[0] = lf->id; 1164 else 1165 error = ENOENT; 1166 sx_xunlock(&kld_sx); 1167out: 1168 free(pathname, M_TEMP); 1169 return (error); 1170} 1171 1172int 1173sys_kldnext(struct thread *td, struct kldnext_args *uap) 1174{ 1175 linker_file_t lf; 1176 int error = 0; 1177 1178#ifdef MAC 1179 error = mac_kld_check_stat(td->td_ucred); 1180 if (error) 1181 return (error); 1182#endif 1183 1184 sx_xlock(&kld_sx); 1185 if (uap->fileid == 0) 1186 lf = TAILQ_FIRST(&linker_files); 1187 else { 1188 lf = linker_find_file_by_id(uap->fileid); 1189 if (lf == NULL) { 1190 error = ENOENT; 1191 goto out; 1192 } 1193 lf = TAILQ_NEXT(lf, link); 1194 } 1195 1196 /* Skip partially loaded files. */ 1197 while (lf != NULL && !(lf->flags & LINKER_FILE_LINKED)) 1198 lf = TAILQ_NEXT(lf, link); 1199 1200 if (lf) 1201 td->td_retval[0] = lf->id; 1202 else 1203 td->td_retval[0] = 0; 1204out: 1205 sx_xunlock(&kld_sx); 1206 return (error); 1207} 1208 1209int 1210sys_kldstat(struct thread *td, struct kldstat_args *uap) 1211{ 1212 struct kld_file_stat stat; 1213 int error, version; 1214 1215 /* 1216 * Check the version of the user's structure. 1217 */ 1218 if ((error = copyin(&uap->stat->version, &version, sizeof(version))) 1219 != 0) 1220 return (error); 1221 if (version != sizeof(struct kld_file_stat_1) && 1222 version != sizeof(struct kld_file_stat)) 1223 return (EINVAL); 1224 1225 error = kern_kldstat(td, uap->fileid, &stat); 1226 if (error != 0) 1227 return (error); 1228 return (copyout(&stat, uap->stat, version)); 1229} 1230 1231int 1232kern_kldstat(struct thread *td, int fileid, struct kld_file_stat *stat) 1233{ 1234 linker_file_t lf; 1235 int namelen; 1236#ifdef MAC 1237 int error; 1238 1239 error = mac_kld_check_stat(td->td_ucred); 1240 if (error) 1241 return (error); 1242#endif 1243 1244 sx_xlock(&kld_sx); 1245 lf = linker_find_file_by_id(fileid); 1246 if (lf == NULL) { 1247 sx_xunlock(&kld_sx); 1248 return (ENOENT); 1249 } 1250 1251 /* Version 1 fields: */ 1252 namelen = strlen(lf->filename) + 1; 1253 if (namelen > MAXPATHLEN) 1254 namelen = MAXPATHLEN; 1255 bcopy(lf->filename, &stat->name[0], namelen); 1256 stat->refs = lf->refs; 1257 stat->id = lf->id; 1258 stat->address = lf->address; 1259 stat->size = lf->size; 1260 /* Version 2 fields: */ 1261 namelen = strlen(lf->pathname) + 1; 1262 if (namelen > MAXPATHLEN) 1263 namelen = MAXPATHLEN; 1264 bcopy(lf->pathname, &stat->pathname[0], namelen); 1265 sx_xunlock(&kld_sx); 1266 1267 td->td_retval[0] = 0; 1268 return (0); 1269} 1270 1271int 1272sys_kldfirstmod(struct thread *td, struct kldfirstmod_args *uap) 1273{ 1274 linker_file_t lf; 1275 module_t mp; 1276 int error = 0; 1277 1278#ifdef MAC 1279 error = mac_kld_check_stat(td->td_ucred); 1280 if (error) 1281 return (error); 1282#endif 1283 1284 sx_xlock(&kld_sx); 1285 lf = linker_find_file_by_id(uap->fileid); 1286 if (lf) { 1287 MOD_SLOCK; 1288 mp = TAILQ_FIRST(&lf->modules); 1289 if (mp != NULL) 1290 td->td_retval[0] = module_getid(mp); 1291 else 1292 td->td_retval[0] = 0; 1293 MOD_SUNLOCK; 1294 } else 1295 error = ENOENT; 1296 sx_xunlock(&kld_sx); 1297 return (error); 1298} 1299 1300int 1301sys_kldsym(struct thread *td, struct kldsym_args *uap) 1302{ 1303 char *symstr = NULL; 1304 c_linker_sym_t sym; 1305 linker_symval_t symval; 1306 linker_file_t lf; 1307 struct kld_sym_lookup lookup; 1308 int error = 0; 1309 1310#ifdef MAC 1311 error = mac_kld_check_stat(td->td_ucred); 1312 if (error) 1313 return (error); 1314#endif 1315 1316 if ((error = copyin(uap->data, &lookup, sizeof(lookup))) != 0) 1317 return (error); 1318 if (lookup.version != sizeof(lookup) || 1319 uap->cmd != KLDSYM_LOOKUP) 1320 return (EINVAL); 1321 symstr = malloc(MAXPATHLEN, M_TEMP, M_WAITOK); 1322 if ((error = copyinstr(lookup.symname, symstr, MAXPATHLEN, NULL)) != 0) 1323 goto out; 1324 sx_xlock(&kld_sx); 1325 if (uap->fileid != 0) { 1326 lf = linker_find_file_by_id(uap->fileid); 1327 if (lf == NULL) 1328 error = ENOENT; 1329 else if (LINKER_LOOKUP_SYMBOL(lf, symstr, &sym) == 0 && 1330 LINKER_SYMBOL_VALUES(lf, sym, &symval) == 0) { 1331 lookup.symvalue = (uintptr_t) symval.value; 1332 lookup.symsize = symval.size; 1333 error = copyout(&lookup, uap->data, sizeof(lookup)); 1334 } else 1335 error = ENOENT; 1336 } else { 1337 TAILQ_FOREACH(lf, &linker_files, link) { 1338 if (LINKER_LOOKUP_SYMBOL(lf, symstr, &sym) == 0 && 1339 LINKER_SYMBOL_VALUES(lf, sym, &symval) == 0) { 1340 lookup.symvalue = (uintptr_t)symval.value; 1341 lookup.symsize = symval.size; 1342 error = copyout(&lookup, uap->data, 1343 sizeof(lookup)); 1344 break; 1345 } 1346 } 1347 if (lf == NULL) 1348 error = ENOENT; 1349 } 1350 sx_xunlock(&kld_sx); 1351out: 1352 free(symstr, M_TEMP); 1353 return (error); 1354} 1355 1356/* 1357 * Preloaded module support 1358 */ 1359 1360static modlist_t 1361modlist_lookup(const char *name, int ver) 1362{ 1363 modlist_t mod; 1364 1365 TAILQ_FOREACH(mod, &found_modules, link) { 1366 if (strcmp(mod->name, name) == 0 && 1367 (ver == 0 || mod->version == ver)) 1368 return (mod); 1369 } 1370 return (NULL); 1371} 1372 1373static modlist_t 1374modlist_lookup2(const char *name, const struct mod_depend *verinfo) 1375{ 1376 modlist_t mod, bestmod; 1377 int ver; 1378 1379 if (verinfo == NULL) 1380 return (modlist_lookup(name, 0)); 1381 bestmod = NULL; 1382 TAILQ_FOREACH(mod, &found_modules, link) { 1383 if (strcmp(mod->name, name) != 0) 1384 continue; 1385 ver = mod->version; 1386 if (ver == verinfo->md_ver_preferred) 1387 return (mod); 1388 if (ver >= verinfo->md_ver_minimum && 1389 ver <= verinfo->md_ver_maximum && 1390 (bestmod == NULL || ver > bestmod->version)) 1391 bestmod = mod; 1392 } 1393 return (bestmod); 1394} 1395 1396static modlist_t 1397modlist_newmodule(const char *modname, int version, linker_file_t container) 1398{ 1399 modlist_t mod; 1400 1401 mod = malloc(sizeof(struct modlist), M_LINKER, M_NOWAIT | M_ZERO); 1402 if (mod == NULL) 1403 panic("no memory for module list"); 1404 mod->container = container; 1405 mod->name = modname; 1406 mod->version = version; 1407 TAILQ_INSERT_TAIL(&found_modules, mod, link); 1408 return (mod); 1409} 1410 1411static void 1412linker_addmodules(linker_file_t lf, struct mod_metadata **start, 1413 struct mod_metadata **stop, int preload) 1414{ 1415 struct mod_metadata *mp, **mdp; 1416 const char *modname; 1417 int ver; 1418 1419 for (mdp = start; mdp < stop; mdp++) { 1420 mp = *mdp; 1421 if (mp->md_type != MDT_VERSION) 1422 continue; 1423 modname = mp->md_cval; 1424 ver = ((struct mod_version *)mp->md_data)->mv_version; 1425 if (modlist_lookup(modname, ver) != NULL) { 1426 printf("module %s already present!\n", modname); 1427 /* XXX what can we do? this is a build error. :-( */ 1428 continue; 1429 } 1430 modlist_newmodule(modname, ver, lf); 1431 } 1432} 1433 1434static void 1435linker_preload(void *arg) 1436{ 1437 caddr_t modptr; 1438 const char *modname, *nmodname; 1439 char *modtype; 1440 linker_file_t lf, nlf; 1441 linker_class_t lc; 1442 int error; 1443 linker_file_list_t loaded_files; 1444 linker_file_list_t depended_files; 1445 struct mod_metadata *mp, *nmp; 1446 struct mod_metadata **start, **stop, **mdp, **nmdp; 1447 const struct mod_depend *verinfo; 1448 int nver; 1449 int resolves; 1450 modlist_t mod; 1451 struct sysinit **si_start, **si_stop; 1452 1453 TAILQ_INIT(&loaded_files); 1454 TAILQ_INIT(&depended_files); 1455 TAILQ_INIT(&found_modules); 1456 error = 0; 1457 1458 modptr = NULL; 1459 sx_xlock(&kld_sx); 1460 while ((modptr = preload_search_next_name(modptr)) != NULL) { 1461 modname = (char *)preload_search_info(modptr, MODINFO_NAME); 1462 modtype = (char *)preload_search_info(modptr, MODINFO_TYPE); 1463 if (modname == NULL) { 1464 printf("Preloaded module at %p does not have a" 1465 " name!\n", modptr); 1466 continue; 1467 } 1468 if (modtype == NULL) { 1469 printf("Preloaded module at %p does not have a type!\n", 1470 modptr); 1471 continue; 1472 } 1473 if (bootverbose) 1474 printf("Preloaded %s \"%s\" at %p.\n", modtype, modname, 1475 modptr); 1476 lf = NULL; 1477 TAILQ_FOREACH(lc, &classes, link) { 1478 error = LINKER_LINK_PRELOAD(lc, modname, &lf); 1479 if (!error) 1480 break; 1481 lf = NULL; 1482 } 1483 if (lf) 1484 TAILQ_INSERT_TAIL(&loaded_files, lf, loaded); 1485 } 1486 1487 /* 1488 * First get a list of stuff in the kernel. 1489 */ 1490 if (linker_file_lookup_set_locked(linker_kernel_file, MDT_SETNAME, 1491 &start, &stop, NULL) == 0) 1492 linker_addmodules(linker_kernel_file, start, stop, 1); 1493 1494 /* 1495 * This is a once-off kinky bubble sort to resolve relocation 1496 * dependency requirements. 1497 */ 1498restart: 1499 TAILQ_FOREACH(lf, &loaded_files, loaded) { 1500 error = linker_file_lookup_set_locked(lf, MDT_SETNAME, &start, 1501 &stop, NULL); 1502 /* 1503 * First, look to see if we would successfully link with this 1504 * stuff. 1505 */ 1506 resolves = 1; /* unless we know otherwise */ 1507 if (!error) { 1508 for (mdp = start; mdp < stop; mdp++) { 1509 mp = *mdp; 1510 if (mp->md_type != MDT_DEPEND) 1511 continue; 1512 modname = mp->md_cval; 1513 verinfo = mp->md_data; 1514 for (nmdp = start; nmdp < stop; nmdp++) { 1515 nmp = *nmdp; 1516 if (nmp->md_type != MDT_VERSION) 1517 continue; 1518 nmodname = nmp->md_cval; 1519 if (strcmp(modname, nmodname) == 0) 1520 break; 1521 } 1522 if (nmdp < stop) /* it's a self reference */ 1523 continue; 1524 1525 /* 1526 * ok, the module isn't here yet, we 1527 * are not finished 1528 */ 1529 if (modlist_lookup2(modname, verinfo) == NULL) 1530 resolves = 0; 1531 } 1532 } 1533 /* 1534 * OK, if we found our modules, we can link. So, "provide" 1535 * the modules inside and add it to the end of the link order 1536 * list. 1537 */ 1538 if (resolves) { 1539 if (!error) { 1540 for (mdp = start; mdp < stop; mdp++) { 1541 mp = *mdp; 1542 if (mp->md_type != MDT_VERSION) 1543 continue; 1544 modname = mp->md_cval; 1545 nver = ((struct mod_version *) 1546 mp->md_data)->mv_version; 1547 if (modlist_lookup(modname, 1548 nver) != NULL) { 1549 printf("module %s already" 1550 " present!\n", modname); 1551 TAILQ_REMOVE(&loaded_files, 1552 lf, loaded); 1553 linker_file_unload(lf, 1554 LINKER_UNLOAD_FORCE); 1555 /* we changed tailq next ptr */ 1556 goto restart; 1557 } 1558 modlist_newmodule(modname, nver, lf); 1559 } 1560 } 1561 TAILQ_REMOVE(&loaded_files, lf, loaded); 1562 TAILQ_INSERT_TAIL(&depended_files, lf, loaded); 1563 /* 1564 * Since we provided modules, we need to restart the 1565 * sort so that the previous files that depend on us 1566 * have a chance. Also, we've busted the tailq next 1567 * pointer with the REMOVE. 1568 */ 1569 goto restart; 1570 } 1571 } 1572 1573 /* 1574 * At this point, we check to see what could not be resolved.. 1575 */ 1576 while ((lf = TAILQ_FIRST(&loaded_files)) != NULL) { 1577 TAILQ_REMOVE(&loaded_files, lf, loaded); 1578 printf("KLD file %s is missing dependencies\n", lf->filename); 1579 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 1580 } 1581 1582 /* 1583 * We made it. Finish off the linking in the order we determined. 1584 */ 1585 TAILQ_FOREACH_SAFE(lf, &depended_files, loaded, nlf) { 1586 if (linker_kernel_file) { 1587 linker_kernel_file->refs++; 1588 error = linker_file_add_dependency(lf, 1589 linker_kernel_file); 1590 if (error) 1591 panic("cannot add dependency"); 1592 } 1593 lf->userrefs++; /* so we can (try to) kldunload it */ 1594 error = linker_file_lookup_set_locked(lf, MDT_SETNAME, &start, 1595 &stop, NULL); 1596 if (!error) { 1597 for (mdp = start; mdp < stop; mdp++) { 1598 mp = *mdp; 1599 if (mp->md_type != MDT_DEPEND) 1600 continue; 1601 modname = mp->md_cval; 1602 verinfo = mp->md_data; 1603 mod = modlist_lookup2(modname, verinfo); 1604 if (mod == NULL) { 1605 printf("KLD file %s - cannot find " 1606 "dependency \"%s\"\n", 1607 lf->filename, modname); 1608 goto fail; 1609 } 1610 /* Don't count self-dependencies */ 1611 if (lf == mod->container) 1612 continue; 1613 mod->container->refs++; 1614 error = linker_file_add_dependency(lf, 1615 mod->container); 1616 if (error) 1617 panic("cannot add dependency"); 1618 } 1619 } 1620 /* 1621 * Now do relocation etc using the symbol search paths 1622 * established by the dependencies 1623 */ 1624 error = LINKER_LINK_PRELOAD_FINISH(lf); 1625 if (error) { 1626 printf("KLD file %s - could not finalize loading\n", 1627 lf->filename); 1628 goto fail; 1629 } 1630 linker_file_register_modules(lf); 1631 if (linker_file_lookup_set_locked(lf, "sysinit_set", &si_start, 1632 &si_stop, NULL) == 0) 1633 sysinit_add(si_start, si_stop); 1634 linker_file_register_sysctls(lf); 1635 lf->flags |= LINKER_FILE_LINKED; 1636 continue; 1637fail: 1638 TAILQ_REMOVE(&depended_files, lf, loaded); 1639 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 1640 } 1641 sx_xunlock(&kld_sx); 1642 /* woohoo! we made it! */ 1643} 1644 1645SYSINIT(preload, SI_SUB_KLD, SI_ORDER_MIDDLE, linker_preload, 0); 1646 1647/* 1648 * Search for a not-loaded module by name. 1649 * 1650 * Modules may be found in the following locations: 1651 * 1652 * - preloaded (result is just the module name) - on disk (result is full path 1653 * to module) 1654 * 1655 * If the module name is qualified in any way (contains path, etc.) the we 1656 * simply return a copy of it. 1657 * 1658 * The search path can be manipulated via sysctl. Note that we use the ';' 1659 * character as a separator to be consistent with the bootloader. 1660 */ 1661 1662static char linker_hintfile[] = "linker.hints"; 1663static char linker_path[MAXPATHLEN] = "/boot/kernel;/boot/modules"; 1664 1665SYSCTL_STRING(_kern, OID_AUTO, module_path, CTLFLAG_RWTUN, linker_path, 1666 sizeof(linker_path), "module load search path"); 1667 1668TUNABLE_STR("module_path", linker_path, sizeof(linker_path)); 1669 1670static char *linker_ext_list[] = { 1671 "", 1672 ".ko", 1673 NULL 1674}; 1675 1676/* 1677 * Check if file actually exists either with or without extension listed in 1678 * the linker_ext_list. (probably should be generic for the rest of the 1679 * kernel) 1680 */ 1681static char * 1682linker_lookup_file(const char *path, int pathlen, const char *name, 1683 int namelen, struct vattr *vap) 1684{ 1685 struct nameidata nd; 1686 struct thread *td = curthread; /* XXX */ 1687 char *result, **cpp, *sep; 1688 int error, len, extlen, reclen, flags; 1689 enum vtype type; 1690 1691 extlen = 0; 1692 for (cpp = linker_ext_list; *cpp; cpp++) { 1693 len = strlen(*cpp); 1694 if (len > extlen) 1695 extlen = len; 1696 } 1697 extlen++; /* trailing '\0' */ 1698 sep = (path[pathlen - 1] != '/') ? "/" : ""; 1699 1700 reclen = pathlen + strlen(sep) + namelen + extlen + 1; 1701 result = malloc(reclen, M_LINKER, M_WAITOK); 1702 for (cpp = linker_ext_list; *cpp; cpp++) { 1703 snprintf(result, reclen, "%.*s%s%.*s%s", pathlen, path, sep, 1704 namelen, name, *cpp); 1705 /* 1706 * Attempt to open the file, and return the path if 1707 * we succeed and it's a regular file. 1708 */ 1709 NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, result, td); 1710 flags = FREAD; 1711 error = vn_open(&nd, &flags, 0, NULL); 1712 if (error == 0) { 1713 NDFREE(&nd, NDF_ONLY_PNBUF); 1714 type = nd.ni_vp->v_type; 1715 if (vap) 1716 VOP_GETATTR(nd.ni_vp, vap, td->td_ucred); 1717 VOP_UNLOCK(nd.ni_vp, 0); 1718 vn_close(nd.ni_vp, FREAD, td->td_ucred, td); 1719 if (type == VREG) 1720 return (result); 1721 } 1722 } 1723 free(result, M_LINKER); 1724 return (NULL); 1725} 1726 1727#define INT_ALIGN(base, ptr) ptr = \ 1728 (base) + (((ptr) - (base) + sizeof(int) - 1) & ~(sizeof(int) - 1)) 1729 1730/* 1731 * Lookup KLD which contains requested module in the "linker.hints" file. If 1732 * version specification is available, then try to find the best KLD. 1733 * Otherwise just find the latest one. 1734 */ 1735static char * 1736linker_hints_lookup(const char *path, int pathlen, const char *modname, 1737 int modnamelen, const struct mod_depend *verinfo) 1738{ 1739 struct thread *td = curthread; /* XXX */ 1740 struct ucred *cred = td ? td->td_ucred : NULL; 1741 struct nameidata nd; 1742 struct vattr vattr, mattr; 1743 u_char *hints = NULL; 1744 u_char *cp, *recptr, *bufend, *result, *best, *pathbuf, *sep; 1745 int error, ival, bestver, *intp, found, flags, clen, blen; 1746 ssize_t reclen; 1747 1748 result = NULL; 1749 bestver = found = 0; 1750 1751 sep = (path[pathlen - 1] != '/') ? "/" : ""; 1752 reclen = imax(modnamelen, strlen(linker_hintfile)) + pathlen + 1753 strlen(sep) + 1; 1754 pathbuf = malloc(reclen, M_LINKER, M_WAITOK); 1755 snprintf(pathbuf, reclen, "%.*s%s%s", pathlen, path, sep, 1756 linker_hintfile); 1757 1758 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, pathbuf, td); 1759 flags = FREAD; 1760 error = vn_open(&nd, &flags, 0, NULL); 1761 if (error) 1762 goto bad; 1763 NDFREE(&nd, NDF_ONLY_PNBUF); 1764 if (nd.ni_vp->v_type != VREG) 1765 goto bad; 1766 best = cp = NULL; 1767 error = VOP_GETATTR(nd.ni_vp, &vattr, cred); 1768 if (error) 1769 goto bad; 1770 /* 1771 * XXX: we need to limit this number to some reasonable value 1772 */ 1773 if (vattr.va_size > LINKER_HINTS_MAX) { 1774 printf("hints file too large %ld\n", (long)vattr.va_size); 1775 goto bad; 1776 } 1777 hints = malloc(vattr.va_size, M_TEMP, M_WAITOK); 1778 if (hints == NULL) 1779 goto bad; 1780 error = vn_rdwr(UIO_READ, nd.ni_vp, (caddr_t)hints, vattr.va_size, 0, 1781 UIO_SYSSPACE, IO_NODELOCKED, cred, NOCRED, &reclen, td); 1782 if (error) 1783 goto bad; 1784 VOP_UNLOCK(nd.ni_vp, 0); 1785 vn_close(nd.ni_vp, FREAD, cred, td); 1786 nd.ni_vp = NULL; 1787 if (reclen != 0) { 1788 printf("can't read %zd\n", reclen); 1789 goto bad; 1790 } 1791 intp = (int *)hints; 1792 ival = *intp++; 1793 if (ival != LINKER_HINTS_VERSION) { 1794 printf("hints file version mismatch %d\n", ival); 1795 goto bad; 1796 } 1797 bufend = hints + vattr.va_size; 1798 recptr = (u_char *)intp; 1799 clen = blen = 0; 1800 while (recptr < bufend && !found) { 1801 intp = (int *)recptr; 1802 reclen = *intp++; 1803 ival = *intp++; 1804 cp = (char *)intp; 1805 switch (ival) { 1806 case MDT_VERSION: 1807 clen = *cp++; 1808 if (clen != modnamelen || bcmp(cp, modname, clen) != 0) 1809 break; 1810 cp += clen; 1811 INT_ALIGN(hints, cp); 1812 ival = *(int *)cp; 1813 cp += sizeof(int); 1814 clen = *cp++; 1815 if (verinfo == NULL || 1816 ival == verinfo->md_ver_preferred) { 1817 found = 1; 1818 break; 1819 } 1820 if (ival >= verinfo->md_ver_minimum && 1821 ival <= verinfo->md_ver_maximum && 1822 ival > bestver) { 1823 bestver = ival; 1824 best = cp; 1825 blen = clen; 1826 } 1827 break; 1828 default: 1829 break; 1830 } 1831 recptr += reclen + sizeof(int); 1832 } 1833 /* 1834 * Finally check if KLD is in the place 1835 */ 1836 if (found) 1837 result = linker_lookup_file(path, pathlen, cp, clen, &mattr); 1838 else if (best) 1839 result = linker_lookup_file(path, pathlen, best, blen, &mattr); 1840 1841 /* 1842 * KLD is newer than hints file. What we should do now? 1843 */ 1844 if (result && timespeccmp(&mattr.va_mtime, &vattr.va_mtime, >)) 1845 printf("warning: KLD '%s' is newer than the linker.hints" 1846 " file\n", result); 1847bad: 1848 free(pathbuf, M_LINKER); 1849 if (hints) 1850 free(hints, M_TEMP); 1851 if (nd.ni_vp != NULL) { 1852 VOP_UNLOCK(nd.ni_vp, 0); 1853 vn_close(nd.ni_vp, FREAD, cred, td); 1854 } 1855 /* 1856 * If nothing found or hints is absent - fallback to the old 1857 * way by using "kldname[.ko]" as module name. 1858 */ 1859 if (!found && !bestver && result == NULL) 1860 result = linker_lookup_file(path, pathlen, modname, 1861 modnamelen, NULL); 1862 return (result); 1863} 1864 1865/* 1866 * Lookup KLD which contains requested module in the all directories. 1867 */ 1868static char * 1869linker_search_module(const char *modname, int modnamelen, 1870 const struct mod_depend *verinfo) 1871{ 1872 char *cp, *ep, *result; 1873 1874 /* 1875 * traverse the linker path 1876 */ 1877 for (cp = linker_path; *cp; cp = ep + 1) { 1878 /* find the end of this component */ 1879 for (ep = cp; (*ep != 0) && (*ep != ';'); ep++); 1880 result = linker_hints_lookup(cp, ep - cp, modname, 1881 modnamelen, verinfo); 1882 if (result != NULL) 1883 return (result); 1884 if (*ep == 0) 1885 break; 1886 } 1887 return (NULL); 1888} 1889 1890/* 1891 * Search for module in all directories listed in the linker_path. 1892 */ 1893static char * 1894linker_search_kld(const char *name) 1895{ 1896 char *cp, *ep, *result; 1897 int len; 1898 1899 /* qualified at all? */ 1900 if (strchr(name, '/')) 1901 return (strdup(name, M_LINKER)); 1902 1903 /* traverse the linker path */ 1904 len = strlen(name); 1905 for (ep = linker_path; *ep; ep++) { 1906 cp = ep; 1907 /* find the end of this component */ 1908 for (; *ep != 0 && *ep != ';'; ep++); 1909 result = linker_lookup_file(cp, ep - cp, name, len, NULL); 1910 if (result != NULL) 1911 return (result); 1912 } 1913 return (NULL); 1914} 1915 1916static const char * 1917linker_basename(const char *path) 1918{ 1919 const char *filename; 1920 1921 filename = strrchr(path, '/'); 1922 if (filename == NULL) 1923 return path; 1924 if (filename[1]) 1925 filename++; 1926 return (filename); 1927} 1928 1929#ifdef HWPMC_HOOKS 1930/* 1931 * Inform hwpmc about the set of kernel modules currently loaded. 1932 */ 1933void * 1934linker_hwpmc_list_objects(void) 1935{ 1936 linker_file_t lf; 1937 struct pmckern_map_in *kobase; 1938 int i, nmappings; 1939 1940 nmappings = 0; 1941 sx_slock(&kld_sx); 1942 TAILQ_FOREACH(lf, &linker_files, link) 1943 nmappings++; 1944 1945 /* Allocate nmappings + 1 entries. */ 1946 kobase = malloc((nmappings + 1) * sizeof(struct pmckern_map_in), 1947 M_LINKER, M_WAITOK | M_ZERO); 1948 i = 0; 1949 TAILQ_FOREACH(lf, &linker_files, link) { 1950 1951 /* Save the info for this linker file. */ 1952 kobase[i].pm_file = lf->filename; 1953 kobase[i].pm_address = (uintptr_t)lf->address; 1954 i++; 1955 } 1956 sx_sunlock(&kld_sx); 1957 1958 KASSERT(i > 0, ("linker_hpwmc_list_objects: no kernel objects?")); 1959 1960 /* The last entry of the malloced area comprises of all zeros. */ 1961 KASSERT(kobase[i].pm_file == NULL, 1962 ("linker_hwpmc_list_objects: last object not NULL")); 1963 1964 return ((void *)kobase); 1965} 1966#endif 1967 1968/* 1969 * Find a file which contains given module and load it, if "parent" is not 1970 * NULL, register a reference to it. 1971 */ 1972static int 1973linker_load_module(const char *kldname, const char *modname, 1974 struct linker_file *parent, const struct mod_depend *verinfo, 1975 struct linker_file **lfpp) 1976{ 1977 linker_file_t lfdep; 1978 const char *filename; 1979 char *pathname; 1980 int error; 1981 1982 sx_assert(&kld_sx, SA_XLOCKED); 1983 if (modname == NULL) { 1984 /* 1985 * We have to load KLD 1986 */ 1987 KASSERT(verinfo == NULL, ("linker_load_module: verinfo" 1988 " is not NULL")); 1989 pathname = linker_search_kld(kldname); 1990 } else { 1991 if (modlist_lookup2(modname, verinfo) != NULL) 1992 return (EEXIST); 1993 if (kldname != NULL) 1994 pathname = strdup(kldname, M_LINKER); 1995 else if (rootvnode == NULL) 1996 pathname = NULL; 1997 else 1998 /* 1999 * Need to find a KLD with required module 2000 */ 2001 pathname = linker_search_module(modname, 2002 strlen(modname), verinfo); 2003 } 2004 if (pathname == NULL) 2005 return (ENOENT); 2006 2007 /* 2008 * Can't load more than one file with the same basename XXX: 2009 * Actually it should be possible to have multiple KLDs with 2010 * the same basename but different path because they can 2011 * provide different versions of the same modules. 2012 */ 2013 filename = linker_basename(pathname); 2014 if (linker_find_file_by_name(filename)) 2015 error = EEXIST; 2016 else do { 2017 error = linker_load_file(pathname, &lfdep); 2018 if (error) 2019 break; 2020 if (modname && verinfo && 2021 modlist_lookup2(modname, verinfo) == NULL) { 2022 linker_file_unload(lfdep, LINKER_UNLOAD_FORCE); 2023 error = ENOENT; 2024 break; 2025 } 2026 if (parent) { 2027 error = linker_file_add_dependency(parent, lfdep); 2028 if (error) 2029 break; 2030 } 2031 if (lfpp) 2032 *lfpp = lfdep; 2033 } while (0); 2034 free(pathname, M_LINKER); 2035 return (error); 2036} 2037 2038/* 2039 * This routine is responsible for finding dependencies of userland initiated 2040 * kldload(2)'s of files. 2041 */ 2042int 2043linker_load_dependencies(linker_file_t lf) 2044{ 2045 linker_file_t lfdep; 2046 struct mod_metadata **start, **stop, **mdp, **nmdp; 2047 struct mod_metadata *mp, *nmp; 2048 const struct mod_depend *verinfo; 2049 modlist_t mod; 2050 const char *modname, *nmodname; 2051 int ver, error = 0, count; 2052 2053 /* 2054 * All files are dependant on /kernel. 2055 */ 2056 sx_assert(&kld_sx, SA_XLOCKED); 2057 if (linker_kernel_file) { 2058 linker_kernel_file->refs++; 2059 error = linker_file_add_dependency(lf, linker_kernel_file); 2060 if (error) 2061 return (error); 2062 } 2063 if (linker_file_lookup_set_locked(lf, MDT_SETNAME, &start, &stop, 2064 &count) != 0) 2065 return (0); 2066 for (mdp = start; mdp < stop; mdp++) { 2067 mp = *mdp; 2068 if (mp->md_type != MDT_VERSION) 2069 continue; 2070 modname = mp->md_cval; 2071 ver = ((struct mod_version *)mp->md_data)->mv_version; 2072 mod = modlist_lookup(modname, ver); 2073 if (mod != NULL) { 2074 printf("interface %s.%d already present in the KLD" 2075 " '%s'!\n", modname, ver, 2076 mod->container->filename); 2077 return (EEXIST); 2078 } 2079 } 2080 2081 for (mdp = start; mdp < stop; mdp++) { 2082 mp = *mdp; 2083 if (mp->md_type != MDT_DEPEND) 2084 continue; 2085 modname = mp->md_cval; 2086 verinfo = mp->md_data; 2087 nmodname = NULL; 2088 for (nmdp = start; nmdp < stop; nmdp++) { 2089 nmp = *nmdp; 2090 if (nmp->md_type != MDT_VERSION) 2091 continue; 2092 nmodname = nmp->md_cval; 2093 if (strcmp(modname, nmodname) == 0) 2094 break; 2095 } 2096 if (nmdp < stop)/* early exit, it's a self reference */ 2097 continue; 2098 mod = modlist_lookup2(modname, verinfo); 2099 if (mod) { /* woohoo, it's loaded already */ 2100 lfdep = mod->container; 2101 lfdep->refs++; 2102 error = linker_file_add_dependency(lf, lfdep); 2103 if (error) 2104 break; 2105 continue; 2106 } 2107 error = linker_load_module(NULL, modname, lf, verinfo, NULL); 2108 if (error) { 2109 printf("KLD %s: depends on %s - not available or" 2110 " version mismatch\n", lf->filename, modname); 2111 break; 2112 } 2113 } 2114 2115 if (error) 2116 return (error); 2117 linker_addmodules(lf, start, stop, 0); 2118 return (error); 2119} 2120 2121static int 2122sysctl_kern_function_list_iterate(const char *name, void *opaque) 2123{ 2124 struct sysctl_req *req; 2125 2126 req = opaque; 2127 return (SYSCTL_OUT(req, name, strlen(name) + 1)); 2128} 2129 2130/* 2131 * Export a nul-separated, double-nul-terminated list of all function names 2132 * in the kernel. 2133 */ 2134static int 2135sysctl_kern_function_list(SYSCTL_HANDLER_ARGS) 2136{ 2137 linker_file_t lf; 2138 int error; 2139 2140#ifdef MAC 2141 error = mac_kld_check_stat(req->td->td_ucred); 2142 if (error) 2143 return (error); 2144#endif 2145 error = sysctl_wire_old_buffer(req, 0); 2146 if (error != 0) 2147 return (error); 2148 sx_xlock(&kld_sx); 2149 TAILQ_FOREACH(lf, &linker_files, link) { 2150 error = LINKER_EACH_FUNCTION_NAME(lf, 2151 sysctl_kern_function_list_iterate, req); 2152 if (error) { 2153 sx_xunlock(&kld_sx); 2154 return (error); 2155 } 2156 } 2157 sx_xunlock(&kld_sx); 2158 return (SYSCTL_OUT(req, "", 1)); 2159} 2160 2161SYSCTL_PROC(_kern, OID_AUTO, function_list, CTLTYPE_OPAQUE | CTLFLAG_RD, 2162 NULL, 0, sysctl_kern_function_list, "", "kernel function list"); 2163