kern_linker.c revision 192895
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 192895 2009-05-27 14:11:23Z jamie $"); 29 30#include "opt_ddb.h" 31#include "opt_hwpmc_hooks.h" 32#include "opt_mac.h" 33 34#include <sys/param.h> 35#include <sys/kernel.h> 36#include <sys/systm.h> 37#include <sys/malloc.h> 38#include <sys/sysproto.h> 39#include <sys/sysent.h> 40#include <sys/priv.h> 41#include <sys/proc.h> 42#include <sys/lock.h> 43#include <sys/mutex.h> 44#include <sys/sx.h> 45#include <sys/module.h> 46#include <sys/mount.h> 47#include <sys/linker.h> 48#include <sys/fcntl.h> 49#include <sys/jail.h> 50#include <sys/libkern.h> 51#include <sys/namei.h> 52#include <sys/vnode.h> 53#include <sys/syscallsubr.h> 54#include <sys/sysctl.h> 55#include <sys/vimage.h> 56 57#include <security/mac/mac_framework.h> 58 59#include "linker_if.h" 60 61#ifdef HWPMC_HOOKS 62#include <sys/pmckern.h> 63#endif 64 65#ifdef KLD_DEBUG 66int kld_debug = 0; 67#endif 68 69#define KLD_LOCK() sx_xlock(&kld_sx) 70#define KLD_UNLOCK() sx_xunlock(&kld_sx) 71#define KLD_LOCKED() sx_xlocked(&kld_sx) 72#define KLD_LOCK_ASSERT() do { \ 73 if (!cold) \ 74 sx_assert(&kld_sx, SX_XLOCKED); \ 75} while (0) 76 77/* 78 * static char *linker_search_path(const char *name, struct mod_depend 79 * *verinfo); 80 */ 81static const char *linker_basename(const char *path); 82 83/* 84 * Find a currently loaded file given its filename. 85 */ 86static linker_file_t linker_find_file_by_name(const char* _filename); 87 88/* 89 * Find a currently loaded file given its file id. 90 */ 91static linker_file_t linker_find_file_by_id(int _fileid); 92 93/* Metadata from the static kernel */ 94SET_DECLARE(modmetadata_set, struct mod_metadata); 95 96MALLOC_DEFINE(M_LINKER, "linker", "kernel linker"); 97 98linker_file_t linker_kernel_file; 99 100static struct sx kld_sx; /* kernel linker lock */ 101 102/* 103 * Load counter used by clients to determine if a linker file has been 104 * re-loaded. This counter is incremented for each file load. 105 */ 106static int loadcnt; 107 108static linker_class_list_t classes; 109static linker_file_list_t linker_files; 110static int next_file_id = 1; 111static int linker_no_more_classes = 0; 112 113#define LINKER_GET_NEXT_FILE_ID(a) do { \ 114 linker_file_t lftmp; \ 115 \ 116 KLD_LOCK_ASSERT(); \ 117retry: \ 118 TAILQ_FOREACH(lftmp, &linker_files, link) { \ 119 if (next_file_id == lftmp->id) { \ 120 next_file_id++; \ 121 goto retry; \ 122 } \ 123 } \ 124 (a) = next_file_id; \ 125} while(0) 126 127 128/* XXX wrong name; we're looking at version provision tags here, not modules */ 129typedef TAILQ_HEAD(, modlist) modlisthead_t; 130struct modlist { 131 TAILQ_ENTRY(modlist) link; /* chain together all modules */ 132 linker_file_t container; 133 const char *name; 134 int version; 135}; 136typedef struct modlist *modlist_t; 137static modlisthead_t found_modules; 138 139static int linker_file_add_dependency(linker_file_t file, 140 linker_file_t dep); 141static caddr_t linker_file_lookup_symbol_internal(linker_file_t file, 142 const char* name, int deps); 143static int linker_load_module(const char *kldname, 144 const char *modname, struct linker_file *parent, 145 struct mod_depend *verinfo, struct linker_file **lfpp); 146static modlist_t modlist_lookup2(const char *name, struct mod_depend *verinfo); 147 148static char * 149linker_strdup(const char *str) 150{ 151 char *result; 152 153 if ((result = malloc((strlen(str) + 1), M_LINKER, M_WAITOK)) != NULL) 154 strcpy(result, str); 155 return (result); 156} 157 158static void 159linker_init(void *arg) 160{ 161 162 sx_init(&kld_sx, "kernel linker"); 163 TAILQ_INIT(&classes); 164 TAILQ_INIT(&linker_files); 165} 166 167SYSINIT(linker, SI_SUB_KLD, SI_ORDER_FIRST, linker_init, 0); 168 169static void 170linker_stop_class_add(void *arg) 171{ 172 173 linker_no_more_classes = 1; 174} 175 176SYSINIT(linker_class, SI_SUB_KLD, SI_ORDER_ANY, linker_stop_class_add, NULL); 177 178int 179linker_add_class(linker_class_t lc) 180{ 181 182 /* 183 * We disallow any class registration past SI_ORDER_ANY 184 * of SI_SUB_KLD. We bump the reference count to keep the 185 * ops from being freed. 186 */ 187 if (linker_no_more_classes == 1) 188 return (EPERM); 189 kobj_class_compile((kobj_class_t) lc); 190 ((kobj_class_t)lc)->refs++; /* XXX: kobj_mtx */ 191 TAILQ_INSERT_TAIL(&classes, lc, link); 192 return (0); 193} 194 195static void 196linker_file_sysinit(linker_file_t lf) 197{ 198 struct sysinit **start, **stop, **sipp, **xipp, *save; 199 200 KLD_DPF(FILE, ("linker_file_sysinit: calling SYSINITs for %s\n", 201 lf->filename)); 202 203 if (linker_file_lookup_set(lf, "sysinit_set", &start, &stop, NULL) != 0) 204 return; 205 /* 206 * Perform a bubble sort of the system initialization objects by 207 * their subsystem (primary key) and order (secondary key). 208 * 209 * Since some things care about execution order, this is the operation 210 * which ensures continued function. 211 */ 212 for (sipp = start; sipp < stop; sipp++) { 213 for (xipp = sipp + 1; xipp < stop; xipp++) { 214 if ((*sipp)->subsystem < (*xipp)->subsystem || 215 ((*sipp)->subsystem == (*xipp)->subsystem && 216 (*sipp)->order <= (*xipp)->order)) 217 continue; /* skip */ 218 save = *sipp; 219 *sipp = *xipp; 220 *xipp = save; 221 } 222 } 223 224 /* 225 * Traverse the (now) ordered list of system initialization tasks. 226 * Perform each task, and continue on to the next task. 227 */ 228 mtx_lock(&Giant); 229 for (sipp = start; sipp < stop; sipp++) { 230 if ((*sipp)->subsystem == SI_SUB_DUMMY) 231 continue; /* skip dummy task(s) */ 232 233 /* Call function */ 234 (*((*sipp)->func)) ((*sipp)->udata); 235 } 236 mtx_unlock(&Giant); 237} 238 239static void 240linker_file_sysuninit(linker_file_t lf) 241{ 242 struct sysinit **start, **stop, **sipp, **xipp, *save; 243 244 KLD_DPF(FILE, ("linker_file_sysuninit: calling SYSUNINITs for %s\n", 245 lf->filename)); 246 247 if (linker_file_lookup_set(lf, "sysuninit_set", &start, &stop, 248 NULL) != 0) 249 return; 250 251 /* 252 * Perform a reverse bubble sort of the system initialization objects 253 * by their subsystem (primary key) and order (secondary key). 254 * 255 * Since some things care about execution order, this is the operation 256 * which ensures continued function. 257 */ 258 for (sipp = start; sipp < stop; sipp++) { 259 for (xipp = sipp + 1; xipp < stop; xipp++) { 260 if ((*sipp)->subsystem > (*xipp)->subsystem || 261 ((*sipp)->subsystem == (*xipp)->subsystem && 262 (*sipp)->order >= (*xipp)->order)) 263 continue; /* skip */ 264 save = *sipp; 265 *sipp = *xipp; 266 *xipp = save; 267 } 268 } 269 270 /* 271 * Traverse the (now) ordered list of system initialization tasks. 272 * Perform each task, and continue on to the next task. 273 */ 274 mtx_lock(&Giant); 275 for (sipp = start; sipp < stop; sipp++) { 276 if ((*sipp)->subsystem == SI_SUB_DUMMY) 277 continue; /* skip dummy task(s) */ 278 279 /* Call function */ 280 (*((*sipp)->func)) ((*sipp)->udata); 281 } 282 mtx_unlock(&Giant); 283} 284 285static void 286linker_file_register_sysctls(linker_file_t lf) 287{ 288 struct sysctl_oid **start, **stop, **oidp; 289 290 KLD_DPF(FILE, 291 ("linker_file_register_sysctls: registering SYSCTLs for %s\n", 292 lf->filename)); 293 294 if (linker_file_lookup_set(lf, "sysctl_set", &start, &stop, NULL) != 0) 295 return; 296 297 sysctl_lock(); 298 for (oidp = start; oidp < stop; oidp++) 299 sysctl_register_oid(*oidp); 300 sysctl_unlock(); 301} 302 303static void 304linker_file_unregister_sysctls(linker_file_t lf) 305{ 306 struct sysctl_oid **start, **stop, **oidp; 307 308 KLD_DPF(FILE, ("linker_file_unregister_sysctls: registering SYSCTLs" 309 " for %s\n", lf->filename)); 310 311 if (linker_file_lookup_set(lf, "sysctl_set", &start, &stop, NULL) != 0) 312 return; 313 314 sysctl_lock(); 315 for (oidp = start; oidp < stop; oidp++) 316 sysctl_unregister_oid(*oidp); 317 sysctl_unlock(); 318} 319 320static int 321linker_file_register_modules(linker_file_t lf) 322{ 323 struct mod_metadata **start, **stop, **mdp; 324 const moduledata_t *moddata; 325 int first_error, error; 326 327 KLD_DPF(FILE, ("linker_file_register_modules: registering modules" 328 " in %s\n", lf->filename)); 329 330 if (linker_file_lookup_set(lf, "modmetadata_set", &start, 331 &stop, NULL) != 0) { 332 /* 333 * This fallback should be unnecessary, but if we get booted 334 * from boot2 instead of loader and we are missing our 335 * metadata then we have to try the best we can. 336 */ 337 if (lf == linker_kernel_file) { 338 start = SET_BEGIN(modmetadata_set); 339 stop = SET_LIMIT(modmetadata_set); 340 } else 341 return (0); 342 } 343 first_error = 0; 344 for (mdp = start; mdp < stop; mdp++) { 345 if ((*mdp)->md_type != MDT_MODULE) 346 continue; 347 moddata = (*mdp)->md_data; 348 KLD_DPF(FILE, ("Registering module %s in %s\n", 349 moddata->name, lf->filename)); 350 error = module_register(moddata, lf); 351 if (error) { 352 printf("Module %s failed to register: %d\n", 353 moddata->name, error); 354 if (first_error == 0) 355 first_error = error; 356 } 357 } 358 return (first_error); 359} 360 361static void 362linker_init_kernel_modules(void) 363{ 364 365 linker_file_register_modules(linker_kernel_file); 366} 367 368SYSINIT(linker_kernel, SI_SUB_KLD, SI_ORDER_ANY, linker_init_kernel_modules, 369 0); 370 371static int 372linker_load_file(const char *filename, linker_file_t *result) 373{ 374 linker_class_t lc; 375 linker_file_t lf; 376 int foundfile, error; 377 378 /* Refuse to load modules if securelevel raised */ 379 if (prison0.pr_securelevel > 0) 380 return (EPERM); 381 382 KLD_LOCK_ASSERT(); 383 lf = linker_find_file_by_name(filename); 384 if (lf) { 385 KLD_DPF(FILE, ("linker_load_file: file %s is already loaded," 386 " incrementing refs\n", filename)); 387 *result = lf; 388 lf->refs++; 389 return (0); 390 } 391 foundfile = 0; 392 error = 0; 393 394 /* 395 * We do not need to protect (lock) classes here because there is 396 * no class registration past startup (SI_SUB_KLD, SI_ORDER_ANY) 397 * and there is no class deregistration mechanism at this time. 398 */ 399 TAILQ_FOREACH(lc, &classes, link) { 400 KLD_DPF(FILE, ("linker_load_file: trying to load %s\n", 401 filename)); 402 error = LINKER_LOAD_FILE(lc, filename, &lf); 403 /* 404 * If we got something other than ENOENT, then it exists but 405 * we cannot load it for some other reason. 406 */ 407 if (error != ENOENT) 408 foundfile = 1; 409 if (lf) { 410 error = linker_file_register_modules(lf); 411 if (error == EEXIST) { 412 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 413 return (error); 414 } 415 KLD_UNLOCK(); 416 linker_file_register_sysctls(lf); 417 linker_file_sysinit(lf); 418 KLD_LOCK(); 419 lf->flags |= LINKER_FILE_LINKED; 420 *result = lf; 421 return (0); 422 } 423 } 424 /* 425 * Less than ideal, but tells the user whether it failed to load or 426 * the module was not found. 427 */ 428 if (foundfile) { 429 430 /* 431 * If the file type has not been recognized by the last try 432 * printout a message before to fail. 433 */ 434 if (error == ENOSYS) 435 printf("linker_load_file: Unsupported file type\n"); 436 437 /* 438 * Format not recognized or otherwise unloadable. 439 * When loading a module that is statically built into 440 * the kernel EEXIST percolates back up as the return 441 * value. Preserve this so that apps like sysinstall 442 * can recognize this special case and not post bogus 443 * dialog boxes. 444 */ 445 if (error != EEXIST) 446 error = ENOEXEC; 447 } else 448 error = ENOENT; /* Nothing found */ 449 return (error); 450} 451 452int 453linker_reference_module(const char *modname, struct mod_depend *verinfo, 454 linker_file_t *result) 455{ 456 modlist_t mod; 457 int error; 458 459 KLD_LOCK(); 460 if ((mod = modlist_lookup2(modname, verinfo)) != NULL) { 461 *result = mod->container; 462 (*result)->refs++; 463 KLD_UNLOCK(); 464 return (0); 465 } 466 467 error = linker_load_module(NULL, modname, NULL, verinfo, result); 468 KLD_UNLOCK(); 469 return (error); 470} 471 472int 473linker_release_module(const char *modname, struct mod_depend *verinfo, 474 linker_file_t lf) 475{ 476 modlist_t mod; 477 int error; 478 479 KLD_LOCK(); 480 if (lf == NULL) { 481 KASSERT(modname != NULL, 482 ("linker_release_module: no file or name")); 483 mod = modlist_lookup2(modname, verinfo); 484 if (mod == NULL) { 485 KLD_UNLOCK(); 486 return (ESRCH); 487 } 488 lf = mod->container; 489 } else 490 KASSERT(modname == NULL && verinfo == NULL, 491 ("linker_release_module: both file and name")); 492 error = linker_file_unload(lf, LINKER_UNLOAD_NORMAL); 493 KLD_UNLOCK(); 494 return (error); 495} 496 497static linker_file_t 498linker_find_file_by_name(const char *filename) 499{ 500 linker_file_t lf; 501 char *koname; 502 503 koname = malloc(strlen(filename) + 4, M_LINKER, M_WAITOK); 504 sprintf(koname, "%s.ko", filename); 505 506 KLD_LOCK_ASSERT(); 507 TAILQ_FOREACH(lf, &linker_files, link) { 508 if (strcmp(lf->filename, koname) == 0) 509 break; 510 if (strcmp(lf->filename, filename) == 0) 511 break; 512 } 513 free(koname, M_LINKER); 514 return (lf); 515} 516 517static linker_file_t 518linker_find_file_by_id(int fileid) 519{ 520 linker_file_t lf; 521 522 KLD_LOCK_ASSERT(); 523 TAILQ_FOREACH(lf, &linker_files, link) 524 if (lf->id == fileid && lf->flags & LINKER_FILE_LINKED) 525 break; 526 return (lf); 527} 528 529int 530linker_file_foreach(linker_predicate_t *predicate, void *context) 531{ 532 linker_file_t lf; 533 int retval = 0; 534 535 KLD_LOCK(); 536 TAILQ_FOREACH(lf, &linker_files, link) { 537 retval = predicate(lf, context); 538 if (retval != 0) 539 break; 540 } 541 KLD_UNLOCK(); 542 return (retval); 543} 544 545linker_file_t 546linker_make_file(const char *pathname, linker_class_t lc) 547{ 548 linker_file_t lf; 549 const char *filename; 550 551 KLD_LOCK_ASSERT(); 552 filename = linker_basename(pathname); 553 554 KLD_DPF(FILE, ("linker_make_file: new file, filename='%s' for pathname='%s'\n", filename, pathname)); 555 lf = (linker_file_t)kobj_create((kobj_class_t)lc, M_LINKER, M_WAITOK); 556 if (lf == NULL) 557 return (NULL); 558 lf->refs = 1; 559 lf->userrefs = 0; 560 lf->flags = 0; 561 lf->filename = linker_strdup(filename); 562 lf->pathname = linker_strdup(pathname); 563 LINKER_GET_NEXT_FILE_ID(lf->id); 564 lf->ndeps = 0; 565 lf->deps = NULL; 566 lf->loadcnt = ++loadcnt; 567 lf->sdt_probes = NULL; 568 lf->sdt_nprobes = 0; 569 STAILQ_INIT(&lf->common); 570 TAILQ_INIT(&lf->modules); 571 TAILQ_INSERT_TAIL(&linker_files, lf, link); 572 return (lf); 573} 574 575int 576linker_file_unload(linker_file_t file, int flags) 577{ 578 module_t mod, next; 579 modlist_t ml, nextml; 580 struct common_symbol *cp; 581 int error, i; 582 583 /* Refuse to unload modules if securelevel raised. */ 584 if (prison0.pr_securelevel > 0) 585 return (EPERM); 586 587 KLD_LOCK_ASSERT(); 588 KLD_DPF(FILE, ("linker_file_unload: lf->refs=%d\n", file->refs)); 589 590 /* Easy case of just dropping a reference. */ 591 if (file->refs > 1) { 592 file->refs--; 593 return (0); 594 } 595 596 KLD_DPF(FILE, ("linker_file_unload: file is unloading," 597 " informing modules\n")); 598 599 /* 600 * Quiesce all the modules to give them a chance to veto the unload. 601 */ 602 MOD_SLOCK; 603 for (mod = TAILQ_FIRST(&file->modules); mod; 604 mod = module_getfnext(mod)) { 605 606 error = module_quiesce(mod); 607 if (error != 0 && flags != LINKER_UNLOAD_FORCE) { 608 KLD_DPF(FILE, ("linker_file_unload: module %s" 609 " vetoed unload\n", module_getname(mod))); 610 /* 611 * XXX: Do we need to tell all the quiesced modules 612 * that they can resume work now via a new module 613 * event? 614 */ 615 MOD_SUNLOCK; 616 return (error); 617 } 618 } 619 MOD_SUNLOCK; 620 621 /* 622 * Inform any modules associated with this file that they are 623 * being be unloaded. 624 */ 625 MOD_XLOCK; 626 for (mod = TAILQ_FIRST(&file->modules); mod; mod = next) { 627 next = module_getfnext(mod); 628 MOD_XUNLOCK; 629 630 /* 631 * Give the module a chance to veto the unload. 632 */ 633 if ((error = module_unload(mod)) != 0) { 634 KLD_DPF(FILE, ("linker_file_unload: module %s" 635 " failed unload\n", mod)); 636 return (error); 637 } 638 MOD_XLOCK; 639 module_release(mod); 640 } 641 MOD_XUNLOCK; 642 643 TAILQ_FOREACH_SAFE(ml, &found_modules, link, nextml) { 644 if (ml->container == file) { 645 TAILQ_REMOVE(&found_modules, ml, link); 646 free(ml, M_LINKER); 647 } 648 } 649 650 /* 651 * Don't try to run SYSUNINITs if we are unloaded due to a 652 * link error. 653 */ 654 if (file->flags & LINKER_FILE_LINKED) { 655 file->flags &= ~LINKER_FILE_LINKED; 656 KLD_UNLOCK(); 657 linker_file_sysuninit(file); 658 linker_file_unregister_sysctls(file); 659 KLD_LOCK(); 660 } 661 TAILQ_REMOVE(&linker_files, file, link); 662 663 if (file->deps) { 664 for (i = 0; i < file->ndeps; i++) 665 linker_file_unload(file->deps[i], flags); 666 free(file->deps, M_LINKER); 667 file->deps = NULL; 668 } 669 while ((cp = STAILQ_FIRST(&file->common)) != NULL) { 670 STAILQ_REMOVE_HEAD(&file->common, link); 671 free(cp, M_LINKER); 672 } 673 674 LINKER_UNLOAD(file); 675 if (file->filename) { 676 free(file->filename, M_LINKER); 677 file->filename = NULL; 678 } 679 if (file->pathname) { 680 free(file->pathname, M_LINKER); 681 file->pathname = NULL; 682 } 683 kobj_delete((kobj_t) file, M_LINKER); 684 return (0); 685} 686 687int 688linker_ctf_get(linker_file_t file, linker_ctf_t *lc) 689{ 690 return (LINKER_CTF_GET(file, lc)); 691} 692 693static int 694linker_file_add_dependency(linker_file_t file, linker_file_t dep) 695{ 696 linker_file_t *newdeps; 697 698 KLD_LOCK_ASSERT(); 699 newdeps = malloc((file->ndeps + 1) * sizeof(linker_file_t *), 700 M_LINKER, M_WAITOK | M_ZERO); 701 if (newdeps == NULL) 702 return (ENOMEM); 703 704 if (file->deps) { 705 bcopy(file->deps, newdeps, 706 file->ndeps * sizeof(linker_file_t *)); 707 free(file->deps, M_LINKER); 708 } 709 file->deps = newdeps; 710 file->deps[file->ndeps] = dep; 711 file->ndeps++; 712 return (0); 713} 714 715/* 716 * Locate a linker set and its contents. This is a helper function to avoid 717 * linker_if.h exposure elsewhere. Note: firstp and lastp are really void **. 718 * This function is used in this file so we can avoid having lots of (void **) 719 * casts. 720 */ 721int 722linker_file_lookup_set(linker_file_t file, const char *name, 723 void *firstp, void *lastp, int *countp) 724{ 725 int error, locked; 726 727 locked = KLD_LOCKED(); 728 if (!locked) 729 KLD_LOCK(); 730 error = LINKER_LOOKUP_SET(file, name, firstp, lastp, countp); 731 if (!locked) 732 KLD_UNLOCK(); 733 return (error); 734} 735 736/* 737 * List all functions in a file. 738 */ 739int 740linker_file_function_listall(linker_file_t lf, 741 linker_function_nameval_callback_t callback_func, void *arg) 742{ 743 return (LINKER_EACH_FUNCTION_NAMEVAL(lf, callback_func, arg)); 744} 745 746caddr_t 747linker_file_lookup_symbol(linker_file_t file, const char *name, int deps) 748{ 749 caddr_t sym; 750 int locked; 751 752 locked = KLD_LOCKED(); 753 if (!locked) 754 KLD_LOCK(); 755 sym = linker_file_lookup_symbol_internal(file, name, deps); 756 if (!locked) 757 KLD_UNLOCK(); 758 return (sym); 759} 760 761static caddr_t 762linker_file_lookup_symbol_internal(linker_file_t file, const char *name, 763 int deps) 764{ 765 c_linker_sym_t sym; 766 linker_symval_t symval; 767 caddr_t address; 768 size_t common_size = 0; 769 int i; 770 771 KLD_LOCK_ASSERT(); 772 KLD_DPF(SYM, ("linker_file_lookup_symbol: file=%p, name=%s, deps=%d\n", 773 file, name, deps)); 774 775 if (LINKER_LOOKUP_SYMBOL(file, name, &sym) == 0) { 776 LINKER_SYMBOL_VALUES(file, sym, &symval); 777 if (symval.value == 0) 778 /* 779 * For commons, first look them up in the 780 * dependencies and only allocate space if not found 781 * there. 782 */ 783 common_size = symval.size; 784 else { 785 KLD_DPF(SYM, ("linker_file_lookup_symbol: symbol" 786 ".value=%p\n", symval.value)); 787 return (symval.value); 788 } 789 } 790 if (deps) { 791 for (i = 0; i < file->ndeps; i++) { 792 address = linker_file_lookup_symbol_internal( 793 file->deps[i], name, 0); 794 if (address) { 795 KLD_DPF(SYM, ("linker_file_lookup_symbol:" 796 " deps value=%p\n", address)); 797 return (address); 798 } 799 } 800 } 801 if (common_size > 0) { 802 /* 803 * This is a common symbol which was not found in the 804 * dependencies. We maintain a simple common symbol table in 805 * the file object. 806 */ 807 struct common_symbol *cp; 808 809 STAILQ_FOREACH(cp, &file->common, link) { 810 if (strcmp(cp->name, name) == 0) { 811 KLD_DPF(SYM, ("linker_file_lookup_symbol:" 812 " old common value=%p\n", cp->address)); 813 return (cp->address); 814 } 815 } 816 /* 817 * Round the symbol size up to align. 818 */ 819 common_size = (common_size + sizeof(int) - 1) & -sizeof(int); 820 cp = malloc(sizeof(struct common_symbol) 821 + common_size + strlen(name) + 1, M_LINKER, 822 M_WAITOK | M_ZERO); 823 cp->address = (caddr_t)(cp + 1); 824 cp->name = cp->address + common_size; 825 strcpy(cp->name, name); 826 bzero(cp->address, common_size); 827 STAILQ_INSERT_TAIL(&file->common, cp, link); 828 829 KLD_DPF(SYM, ("linker_file_lookup_symbol: new common" 830 " value=%p\n", cp->address)); 831 return (cp->address); 832 } 833 KLD_DPF(SYM, ("linker_file_lookup_symbol: fail\n")); 834 return (0); 835} 836 837/* 838 * Both DDB and stack(9) rely on the kernel linker to provide forward and 839 * backward lookup of symbols. However, DDB and sometimes stack(9) need to 840 * do this in a lockfree manner. We provide a set of internal helper 841 * routines to perform these operations without locks, and then wrappers that 842 * optionally lock. 843 * 844 * linker_debug_lookup() is ifdef DDB as currently it's only used by DDB. 845 */ 846#ifdef DDB 847static int 848linker_debug_lookup(const char *symstr, c_linker_sym_t *sym) 849{ 850 linker_file_t lf; 851 852 TAILQ_FOREACH(lf, &linker_files, link) { 853 if (LINKER_LOOKUP_SYMBOL(lf, symstr, sym) == 0) 854 return (0); 855 } 856 return (ENOENT); 857} 858#endif 859 860static int 861linker_debug_search_symbol(caddr_t value, c_linker_sym_t *sym, long *diffp) 862{ 863 linker_file_t lf; 864 c_linker_sym_t best, es; 865 u_long diff, bestdiff, off; 866 867 best = 0; 868 off = (uintptr_t)value; 869 bestdiff = off; 870 TAILQ_FOREACH(lf, &linker_files, link) { 871 if (LINKER_SEARCH_SYMBOL(lf, value, &es, &diff) != 0) 872 continue; 873 if (es != 0 && diff < bestdiff) { 874 best = es; 875 bestdiff = diff; 876 } 877 if (bestdiff == 0) 878 break; 879 } 880 if (best) { 881 *sym = best; 882 *diffp = bestdiff; 883 return (0); 884 } else { 885 *sym = 0; 886 *diffp = off; 887 return (ENOENT); 888 } 889} 890 891static int 892linker_debug_symbol_values(c_linker_sym_t sym, linker_symval_t *symval) 893{ 894 linker_file_t lf; 895 896 TAILQ_FOREACH(lf, &linker_files, link) { 897 if (LINKER_SYMBOL_VALUES(lf, sym, symval) == 0) 898 return (0); 899 } 900 return (ENOENT); 901} 902 903static int 904linker_debug_search_symbol_name(caddr_t value, char *buf, u_int buflen, 905 long *offset) 906{ 907 linker_symval_t symval; 908 c_linker_sym_t sym; 909 int error; 910 911 *offset = 0; 912 error = linker_debug_search_symbol(value, &sym, offset); 913 if (error) 914 return (error); 915 error = linker_debug_symbol_values(sym, &symval); 916 if (error) 917 return (error); 918 strlcpy(buf, symval.name, buflen); 919 return (0); 920} 921 922#ifdef DDB 923/* 924 * DDB Helpers. DDB has to look across multiple files with their own symbol 925 * tables and string tables. 926 * 927 * Note that we do not obey list locking protocols here. We really don't need 928 * DDB to hang because somebody's got the lock held. We'll take the chance 929 * that the files list is inconsistant instead. 930 */ 931int 932linker_ddb_lookup(const char *symstr, c_linker_sym_t *sym) 933{ 934 935 return (linker_debug_lookup(symstr, sym)); 936} 937 938int 939linker_ddb_search_symbol(caddr_t value, c_linker_sym_t *sym, long *diffp) 940{ 941 942 return (linker_debug_search_symbol(value, sym, diffp)); 943} 944 945int 946linker_ddb_symbol_values(c_linker_sym_t sym, linker_symval_t *symval) 947{ 948 949 return (linker_debug_symbol_values(sym, symval)); 950} 951 952int 953linker_ddb_search_symbol_name(caddr_t value, char *buf, u_int buflen, 954 long *offset) 955{ 956 957 return (linker_debug_search_symbol_name(value, buf, buflen, offset)); 958} 959#endif 960 961/* 962 * stack(9) helper for non-debugging environemnts. Unlike DDB helpers, we do 963 * obey locking protocols, and offer a significantly less complex interface. 964 */ 965int 966linker_search_symbol_name(caddr_t value, char *buf, u_int buflen, 967 long *offset) 968{ 969 int error; 970 971 KLD_LOCK(); 972 error = linker_debug_search_symbol_name(value, buf, buflen, offset); 973 KLD_UNLOCK(); 974 return (error); 975} 976 977/* 978 * Syscalls. 979 */ 980int 981kern_kldload(struct thread *td, const char *file, int *fileid) 982{ 983#ifdef HWPMC_HOOKS 984 struct pmckern_map_in pkm; 985#endif 986 const char *kldname, *modname; 987 linker_file_t lf; 988 int error; 989 990 if ((error = securelevel_gt(td->td_ucred, 0)) != 0) 991 return (error); 992 993 if ((error = priv_check(td, PRIV_KLD_LOAD)) != 0) 994 return (error); 995 996#ifdef VIMAGE 997 /* Only the default vimage is permitted to kldload modules. */ 998 if (!IS_DEFAULT_VIMAGE(TD_TO_VIMAGE(td))) 999 return (EPERM); 1000#endif 1001 1002 /* 1003 * It is possible that kldloaded module will attach a new ifnet, 1004 * so vnet context must be set when this ocurs. 1005 */ 1006 CURVNET_SET(TD_TO_VNET(td)); 1007 1008 /* 1009 * If file does not contain a qualified name or any dot in it 1010 * (kldname.ko, or kldname.ver.ko) treat it as an interface 1011 * name. 1012 */ 1013 if (index(file, '/') || index(file, '.')) { 1014 kldname = file; 1015 modname = NULL; 1016 } else { 1017 kldname = NULL; 1018 modname = file; 1019 } 1020 1021 KLD_LOCK(); 1022 error = linker_load_module(kldname, modname, NULL, NULL, &lf); 1023 if (error) 1024 goto unlock; 1025#ifdef HWPMC_HOOKS 1026 pkm.pm_file = lf->filename; 1027 pkm.pm_address = (uintptr_t) lf->address; 1028 PMC_CALL_HOOK(td, PMC_FN_KLD_LOAD, (void *) &pkm); 1029#endif 1030 lf->userrefs++; 1031 if (fileid != NULL) 1032 *fileid = lf->id; 1033unlock: 1034 KLD_UNLOCK(); 1035 CURVNET_RESTORE(); 1036 return (error); 1037} 1038 1039int 1040kldload(struct thread *td, struct kldload_args *uap) 1041{ 1042 char *pathname = NULL; 1043 int error, fileid; 1044 1045 td->td_retval[0] = -1; 1046 1047 pathname = malloc(MAXPATHLEN, M_TEMP, M_WAITOK); 1048 error = copyinstr(uap->file, pathname, MAXPATHLEN, NULL); 1049 if (error == 0) { 1050 error = kern_kldload(td, pathname, &fileid); 1051 if (error == 0) 1052 td->td_retval[0] = fileid; 1053 } 1054 free(pathname, M_TEMP); 1055 return (error); 1056} 1057 1058int 1059kern_kldunload(struct thread *td, int fileid, int flags) 1060{ 1061#ifdef HWPMC_HOOKS 1062 struct pmckern_map_out pkm; 1063#endif 1064 linker_file_t lf; 1065 int error = 0; 1066 1067 if ((error = securelevel_gt(td->td_ucred, 0)) != 0) 1068 return (error); 1069 1070 if ((error = priv_check(td, PRIV_KLD_UNLOAD)) != 0) 1071 return (error); 1072 1073#ifdef VIMAGE 1074 /* Only the default vimage is permitted to kldunload modules. */ 1075 if (!IS_DEFAULT_VIMAGE(TD_TO_VIMAGE(td))) 1076 return (EPERM); 1077#endif 1078 1079 CURVNET_SET(TD_TO_VNET(td)); 1080 KLD_LOCK(); 1081 lf = linker_find_file_by_id(fileid); 1082 if (lf) { 1083 KLD_DPF(FILE, ("kldunload: lf->userrefs=%d\n", lf->userrefs)); 1084 1085 /* Check if there are DTrace probes enabled on this file. */ 1086 if (lf->nenabled > 0) { 1087 printf("kldunload: attempt to unload file that has" 1088 " DTrace probes enabled\n"); 1089 error = EBUSY; 1090 } else if (lf->userrefs == 0) { 1091 /* 1092 * XXX: maybe LINKER_UNLOAD_FORCE should override ? 1093 */ 1094 printf("kldunload: attempt to unload file that was" 1095 " loaded by the kernel\n"); 1096 error = EBUSY; 1097 } else { 1098#ifdef HWPMC_HOOKS 1099 /* Save data needed by hwpmc(4) before unloading. */ 1100 pkm.pm_address = (uintptr_t) lf->address; 1101 pkm.pm_size = lf->size; 1102#endif 1103 lf->userrefs--; 1104 error = linker_file_unload(lf, flags); 1105 if (error) 1106 lf->userrefs++; 1107 } 1108 } else 1109 error = ENOENT; 1110 1111#ifdef HWPMC_HOOKS 1112 if (error == 0) 1113 PMC_CALL_HOOK(td, PMC_FN_KLD_UNLOAD, (void *) &pkm); 1114#endif 1115 KLD_UNLOCK(); 1116 CURVNET_RESTORE(); 1117 return (error); 1118} 1119 1120int 1121kldunload(struct thread *td, struct kldunload_args *uap) 1122{ 1123 1124 return (kern_kldunload(td, uap->fileid, LINKER_UNLOAD_NORMAL)); 1125} 1126 1127int 1128kldunloadf(struct thread *td, struct kldunloadf_args *uap) 1129{ 1130 1131 if (uap->flags != LINKER_UNLOAD_NORMAL && 1132 uap->flags != LINKER_UNLOAD_FORCE) 1133 return (EINVAL); 1134 return (kern_kldunload(td, uap->fileid, uap->flags)); 1135} 1136 1137int 1138kldfind(struct thread *td, struct kldfind_args *uap) 1139{ 1140 char *pathname; 1141 const char *filename; 1142 linker_file_t lf; 1143 int error; 1144 1145#ifdef MAC 1146 error = mac_kld_check_stat(td->td_ucred); 1147 if (error) 1148 return (error); 1149#endif 1150 1151 td->td_retval[0] = -1; 1152 1153 pathname = malloc(MAXPATHLEN, M_TEMP, M_WAITOK); 1154 if ((error = copyinstr(uap->file, pathname, MAXPATHLEN, NULL)) != 0) 1155 goto out; 1156 1157 filename = linker_basename(pathname); 1158 KLD_LOCK(); 1159 lf = linker_find_file_by_name(filename); 1160 if (lf) 1161 td->td_retval[0] = lf->id; 1162 else 1163 error = ENOENT; 1164 KLD_UNLOCK(); 1165out: 1166 free(pathname, M_TEMP); 1167 return (error); 1168} 1169 1170int 1171kldnext(struct thread *td, struct kldnext_args *uap) 1172{ 1173 linker_file_t lf; 1174 int error = 0; 1175 1176#ifdef MAC 1177 error = mac_kld_check_stat(td->td_ucred); 1178 if (error) 1179 return (error); 1180#endif 1181 1182 KLD_LOCK(); 1183 if (uap->fileid == 0) 1184 lf = TAILQ_FIRST(&linker_files); 1185 else { 1186 lf = linker_find_file_by_id(uap->fileid); 1187 if (lf == NULL) { 1188 error = ENOENT; 1189 goto out; 1190 } 1191 lf = TAILQ_NEXT(lf, link); 1192 } 1193 1194 /* Skip partially loaded files. */ 1195 while (lf != NULL && !(lf->flags & LINKER_FILE_LINKED)) 1196 lf = TAILQ_NEXT(lf, link); 1197 1198 if (lf) 1199 td->td_retval[0] = lf->id; 1200 else 1201 td->td_retval[0] = 0; 1202out: 1203 KLD_UNLOCK(); 1204 return (error); 1205} 1206 1207int 1208kldstat(struct thread *td, struct kldstat_args *uap) 1209{ 1210 struct kld_file_stat stat; 1211 linker_file_t lf; 1212 int error, namelen, version, version_num; 1213 1214 /* 1215 * Check the version of the user's structure. 1216 */ 1217 if ((error = copyin(&uap->stat->version, &version, sizeof(version))) != 0) 1218 return (error); 1219 if (version == sizeof(struct kld_file_stat_1)) 1220 version_num = 1; 1221 else if (version == sizeof(struct kld_file_stat)) 1222 version_num = 2; 1223 else 1224 return (EINVAL); 1225 1226#ifdef MAC 1227 error = mac_kld_check_stat(td->td_ucred); 1228 if (error) 1229 return (error); 1230#endif 1231 1232 KLD_LOCK(); 1233 lf = linker_find_file_by_id(uap->fileid); 1234 if (lf == NULL) { 1235 KLD_UNLOCK(); 1236 return (ENOENT); 1237 } 1238 1239 /* Version 1 fields: */ 1240 namelen = strlen(lf->filename) + 1; 1241 if (namelen > MAXPATHLEN) 1242 namelen = MAXPATHLEN; 1243 bcopy(lf->filename, &stat.name[0], namelen); 1244 stat.refs = lf->refs; 1245 stat.id = lf->id; 1246 stat.address = lf->address; 1247 stat.size = lf->size; 1248 if (version_num > 1) { 1249 /* Version 2 fields: */ 1250 namelen = strlen(lf->pathname) + 1; 1251 if (namelen > MAXPATHLEN) 1252 namelen = MAXPATHLEN; 1253 bcopy(lf->pathname, &stat.pathname[0], namelen); 1254 } 1255 KLD_UNLOCK(); 1256 1257 td->td_retval[0] = 0; 1258 1259 return (copyout(&stat, uap->stat, version)); 1260} 1261 1262int 1263kldfirstmod(struct thread *td, struct kldfirstmod_args *uap) 1264{ 1265 linker_file_t lf; 1266 module_t mp; 1267 int error = 0; 1268 1269#ifdef MAC 1270 error = mac_kld_check_stat(td->td_ucred); 1271 if (error) 1272 return (error); 1273#endif 1274 1275 KLD_LOCK(); 1276 lf = linker_find_file_by_id(uap->fileid); 1277 if (lf) { 1278 MOD_SLOCK; 1279 mp = TAILQ_FIRST(&lf->modules); 1280 if (mp != NULL) 1281 td->td_retval[0] = module_getid(mp); 1282 else 1283 td->td_retval[0] = 0; 1284 MOD_SUNLOCK; 1285 } else 1286 error = ENOENT; 1287 KLD_UNLOCK(); 1288 return (error); 1289} 1290 1291int 1292kldsym(struct thread *td, struct kldsym_args *uap) 1293{ 1294 char *symstr = NULL; 1295 c_linker_sym_t sym; 1296 linker_symval_t symval; 1297 linker_file_t lf; 1298 struct kld_sym_lookup lookup; 1299 int error = 0; 1300 1301#ifdef MAC 1302 error = mac_kld_check_stat(td->td_ucred); 1303 if (error) 1304 return (error); 1305#endif 1306 1307 if ((error = copyin(uap->data, &lookup, sizeof(lookup))) != 0) 1308 return (error); 1309 if (lookup.version != sizeof(lookup) || 1310 uap->cmd != KLDSYM_LOOKUP) 1311 return (EINVAL); 1312 symstr = malloc(MAXPATHLEN, M_TEMP, M_WAITOK); 1313 if ((error = copyinstr(lookup.symname, symstr, MAXPATHLEN, NULL)) != 0) 1314 goto out; 1315 KLD_LOCK(); 1316 if (uap->fileid != 0) { 1317 lf = linker_find_file_by_id(uap->fileid); 1318 if (lf == NULL) 1319 error = ENOENT; 1320 else if (LINKER_LOOKUP_SYMBOL(lf, symstr, &sym) == 0 && 1321 LINKER_SYMBOL_VALUES(lf, sym, &symval) == 0) { 1322 lookup.symvalue = (uintptr_t) symval.value; 1323 lookup.symsize = symval.size; 1324 error = copyout(&lookup, uap->data, sizeof(lookup)); 1325 } else 1326 error = ENOENT; 1327 } else { 1328 TAILQ_FOREACH(lf, &linker_files, link) { 1329 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, 1334 sizeof(lookup)); 1335 break; 1336 } 1337 } 1338#ifndef VIMAGE_GLOBALS 1339 /* 1340 * If the symbol is not found in global namespace, 1341 * try to look it up in the current vimage namespace. 1342 */ 1343 if (lf == NULL) { 1344 CURVNET_SET(TD_TO_VNET(td)); 1345 error = vi_symlookup(&lookup, symstr); 1346 CURVNET_RESTORE(); 1347 if (error == 0) 1348 error = copyout(&lookup, uap->data, 1349 sizeof(lookup)); 1350 } 1351#else 1352 if (lf == NULL) 1353 error = ENOENT; 1354#endif 1355 } 1356 KLD_UNLOCK(); 1357out: 1358 free(symstr, M_TEMP); 1359 return (error); 1360} 1361 1362/* 1363 * Preloaded module support 1364 */ 1365 1366static modlist_t 1367modlist_lookup(const char *name, int ver) 1368{ 1369 modlist_t mod; 1370 1371 TAILQ_FOREACH(mod, &found_modules, link) { 1372 if (strcmp(mod->name, name) == 0 && 1373 (ver == 0 || mod->version == ver)) 1374 return (mod); 1375 } 1376 return (NULL); 1377} 1378 1379static modlist_t 1380modlist_lookup2(const char *name, struct mod_depend *verinfo) 1381{ 1382 modlist_t mod, bestmod; 1383 int ver; 1384 1385 if (verinfo == NULL) 1386 return (modlist_lookup(name, 0)); 1387 bestmod = NULL; 1388 TAILQ_FOREACH(mod, &found_modules, link) { 1389 if (strcmp(mod->name, name) != 0) 1390 continue; 1391 ver = mod->version; 1392 if (ver == verinfo->md_ver_preferred) 1393 return (mod); 1394 if (ver >= verinfo->md_ver_minimum && 1395 ver <= verinfo->md_ver_maximum && 1396 (bestmod == NULL || ver > bestmod->version)) 1397 bestmod = mod; 1398 } 1399 return (bestmod); 1400} 1401 1402static modlist_t 1403modlist_newmodule(const char *modname, int version, linker_file_t container) 1404{ 1405 modlist_t mod; 1406 1407 mod = malloc(sizeof(struct modlist), M_LINKER, M_NOWAIT | M_ZERO); 1408 if (mod == NULL) 1409 panic("no memory for module list"); 1410 mod->container = container; 1411 mod->name = modname; 1412 mod->version = version; 1413 TAILQ_INSERT_TAIL(&found_modules, mod, link); 1414 return (mod); 1415} 1416 1417static void 1418linker_addmodules(linker_file_t lf, struct mod_metadata **start, 1419 struct mod_metadata **stop, int preload) 1420{ 1421 struct mod_metadata *mp, **mdp; 1422 const char *modname; 1423 int ver; 1424 1425 for (mdp = start; mdp < stop; mdp++) { 1426 mp = *mdp; 1427 if (mp->md_type != MDT_VERSION) 1428 continue; 1429 modname = mp->md_cval; 1430 ver = ((struct mod_version *)mp->md_data)->mv_version; 1431 if (modlist_lookup(modname, ver) != NULL) { 1432 printf("module %s already present!\n", modname); 1433 /* XXX what can we do? this is a build error. :-( */ 1434 continue; 1435 } 1436 modlist_newmodule(modname, ver, lf); 1437 } 1438} 1439 1440static void 1441linker_preload(void *arg) 1442{ 1443 caddr_t modptr; 1444 const char *modname, *nmodname; 1445 char *modtype; 1446 linker_file_t lf, nlf; 1447 linker_class_t lc; 1448 int error; 1449 linker_file_list_t loaded_files; 1450 linker_file_list_t depended_files; 1451 struct mod_metadata *mp, *nmp; 1452 struct mod_metadata **start, **stop, **mdp, **nmdp; 1453 struct mod_depend *verinfo; 1454 int nver; 1455 int resolves; 1456 modlist_t mod; 1457 struct sysinit **si_start, **si_stop; 1458 1459 TAILQ_INIT(&loaded_files); 1460 TAILQ_INIT(&depended_files); 1461 TAILQ_INIT(&found_modules); 1462 error = 0; 1463 1464 modptr = NULL; 1465 while ((modptr = preload_search_next_name(modptr)) != NULL) { 1466 modname = (char *)preload_search_info(modptr, MODINFO_NAME); 1467 modtype = (char *)preload_search_info(modptr, MODINFO_TYPE); 1468 if (modname == NULL) { 1469 printf("Preloaded module at %p does not have a" 1470 " name!\n", modptr); 1471 continue; 1472 } 1473 if (modtype == NULL) { 1474 printf("Preloaded module at %p does not have a type!\n", 1475 modptr); 1476 continue; 1477 } 1478 if (bootverbose) 1479 printf("Preloaded %s \"%s\" at %p.\n", modtype, modname, 1480 modptr); 1481 lf = NULL; 1482 TAILQ_FOREACH(lc, &classes, link) { 1483 error = LINKER_LINK_PRELOAD(lc, modname, &lf); 1484 if (!error) 1485 break; 1486 lf = NULL; 1487 } 1488 if (lf) 1489 TAILQ_INSERT_TAIL(&loaded_files, lf, loaded); 1490 } 1491 1492 /* 1493 * First get a list of stuff in the kernel. 1494 */ 1495 if (linker_file_lookup_set(linker_kernel_file, MDT_SETNAME, &start, 1496 &stop, NULL) == 0) 1497 linker_addmodules(linker_kernel_file, start, stop, 1); 1498 1499 /* 1500 * This is a once-off kinky bubble sort to resolve relocation 1501 * dependency requirements. 1502 */ 1503restart: 1504 TAILQ_FOREACH(lf, &loaded_files, loaded) { 1505 error = linker_file_lookup_set(lf, MDT_SETNAME, &start, 1506 &stop, NULL); 1507 /* 1508 * First, look to see if we would successfully link with this 1509 * stuff. 1510 */ 1511 resolves = 1; /* unless we know otherwise */ 1512 if (!error) { 1513 for (mdp = start; mdp < stop; mdp++) { 1514 mp = *mdp; 1515 if (mp->md_type != MDT_DEPEND) 1516 continue; 1517 modname = mp->md_cval; 1518 verinfo = mp->md_data; 1519 for (nmdp = start; nmdp < stop; nmdp++) { 1520 nmp = *nmdp; 1521 if (nmp->md_type != MDT_VERSION) 1522 continue; 1523 nmodname = nmp->md_cval; 1524 if (strcmp(modname, nmodname) == 0) 1525 break; 1526 } 1527 if (nmdp < stop) /* it's a self reference */ 1528 continue; 1529 1530 /* 1531 * ok, the module isn't here yet, we 1532 * are not finished 1533 */ 1534 if (modlist_lookup2(modname, verinfo) == NULL) 1535 resolves = 0; 1536 } 1537 } 1538 /* 1539 * OK, if we found our modules, we can link. So, "provide" 1540 * the modules inside and add it to the end of the link order 1541 * list. 1542 */ 1543 if (resolves) { 1544 if (!error) { 1545 for (mdp = start; mdp < stop; mdp++) { 1546 mp = *mdp; 1547 if (mp->md_type != MDT_VERSION) 1548 continue; 1549 modname = mp->md_cval; 1550 nver = ((struct mod_version *) 1551 mp->md_data)->mv_version; 1552 if (modlist_lookup(modname, 1553 nver) != NULL) { 1554 printf("module %s already" 1555 " present!\n", modname); 1556 TAILQ_REMOVE(&loaded_files, 1557 lf, loaded); 1558 linker_file_unload(lf, 1559 LINKER_UNLOAD_FORCE); 1560 /* we changed tailq next ptr */ 1561 goto restart; 1562 } 1563 modlist_newmodule(modname, nver, lf); 1564 } 1565 } 1566 TAILQ_REMOVE(&loaded_files, lf, loaded); 1567 TAILQ_INSERT_TAIL(&depended_files, lf, loaded); 1568 /* 1569 * Since we provided modules, we need to restart the 1570 * sort so that the previous files that depend on us 1571 * have a chance. Also, we've busted the tailq next 1572 * pointer with the REMOVE. 1573 */ 1574 goto restart; 1575 } 1576 } 1577 1578 /* 1579 * At this point, we check to see what could not be resolved.. 1580 */ 1581 while ((lf = TAILQ_FIRST(&loaded_files)) != NULL) { 1582 TAILQ_REMOVE(&loaded_files, lf, loaded); 1583 printf("KLD file %s is missing dependencies\n", lf->filename); 1584 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 1585 } 1586 1587 /* 1588 * We made it. Finish off the linking in the order we determined. 1589 */ 1590 TAILQ_FOREACH_SAFE(lf, &depended_files, loaded, nlf) { 1591 if (linker_kernel_file) { 1592 linker_kernel_file->refs++; 1593 error = linker_file_add_dependency(lf, 1594 linker_kernel_file); 1595 if (error) 1596 panic("cannot add dependency"); 1597 } 1598 lf->userrefs++; /* so we can (try to) kldunload it */ 1599 error = linker_file_lookup_set(lf, MDT_SETNAME, &start, 1600 &stop, NULL); 1601 if (!error) { 1602 for (mdp = start; mdp < stop; mdp++) { 1603 mp = *mdp; 1604 if (mp->md_type != MDT_DEPEND) 1605 continue; 1606 modname = mp->md_cval; 1607 verinfo = mp->md_data; 1608 mod = modlist_lookup2(modname, verinfo); 1609 /* Don't count self-dependencies */ 1610 if (lf == mod->container) 1611 continue; 1612 mod->container->refs++; 1613 error = linker_file_add_dependency(lf, 1614 mod->container); 1615 if (error) 1616 panic("cannot add dependency"); 1617 } 1618 } 1619 /* 1620 * Now do relocation etc using the symbol search paths 1621 * established by the dependencies 1622 */ 1623 error = LINKER_LINK_PRELOAD_FINISH(lf); 1624 if (error) { 1625 TAILQ_REMOVE(&depended_files, lf, loaded); 1626 printf("KLD file %s - could not finalize loading\n", 1627 lf->filename); 1628 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 1629 continue; 1630 } 1631 linker_file_register_modules(lf); 1632 if (linker_file_lookup_set(lf, "sysinit_set", &si_start, 1633 &si_stop, NULL) == 0) 1634 sysinit_add(si_start, si_stop); 1635 linker_file_register_sysctls(lf); 1636 lf->flags |= LINKER_FILE_LINKED; 1637 } 1638 /* woohoo! we made it! */ 1639} 1640 1641SYSINIT(preload, SI_SUB_KLD, SI_ORDER_MIDDLE, linker_preload, 0); 1642 1643/* 1644 * Search for a not-loaded module by name. 1645 * 1646 * Modules may be found in the following locations: 1647 * 1648 * - preloaded (result is just the module name) - on disk (result is full path 1649 * to module) 1650 * 1651 * If the module name is qualified in any way (contains path, etc.) the we 1652 * simply return a copy of it. 1653 * 1654 * The search path can be manipulated via sysctl. Note that we use the ';' 1655 * character as a separator to be consistent with the bootloader. 1656 */ 1657 1658static char linker_hintfile[] = "linker.hints"; 1659static char linker_path[MAXPATHLEN] = "/boot/kernel;/boot/modules"; 1660 1661SYSCTL_STRING(_kern, OID_AUTO, module_path, CTLFLAG_RW, linker_path, 1662 sizeof(linker_path), "module load search path"); 1663 1664TUNABLE_STR("module_path", linker_path, sizeof(linker_path)); 1665 1666static char *linker_ext_list[] = { 1667 "", 1668 ".ko", 1669 NULL 1670}; 1671 1672/* 1673 * Check if file actually exists either with or without extension listed in 1674 * the linker_ext_list. (probably should be generic for the rest of the 1675 * kernel) 1676 */ 1677static char * 1678linker_lookup_file(const char *path, int pathlen, const char *name, 1679 int namelen, struct vattr *vap) 1680{ 1681 struct nameidata nd; 1682 struct thread *td = curthread; /* XXX */ 1683 char *result, **cpp, *sep; 1684 int error, len, extlen, reclen, flags, vfslocked; 1685 enum vtype type; 1686 1687 extlen = 0; 1688 for (cpp = linker_ext_list; *cpp; cpp++) { 1689 len = strlen(*cpp); 1690 if (len > extlen) 1691 extlen = len; 1692 } 1693 extlen++; /* trailing '\0' */ 1694 sep = (path[pathlen - 1] != '/') ? "/" : ""; 1695 1696 reclen = pathlen + strlen(sep) + namelen + extlen + 1; 1697 result = malloc(reclen, M_LINKER, M_WAITOK); 1698 for (cpp = linker_ext_list; *cpp; cpp++) { 1699 snprintf(result, reclen, "%.*s%s%.*s%s", pathlen, path, sep, 1700 namelen, name, *cpp); 1701 /* 1702 * Attempt to open the file, and return the path if 1703 * we succeed and it's a regular file. 1704 */ 1705 NDINIT(&nd, LOOKUP, FOLLOW | MPSAFE, UIO_SYSSPACE, result, td); 1706 flags = FREAD; 1707 error = vn_open(&nd, &flags, 0, NULL); 1708 if (error == 0) { 1709 vfslocked = NDHASGIANT(&nd); 1710 NDFREE(&nd, NDF_ONLY_PNBUF); 1711 type = nd.ni_vp->v_type; 1712 if (vap) 1713 VOP_GETATTR(nd.ni_vp, vap, td->td_ucred); 1714 VOP_UNLOCK(nd.ni_vp, 0); 1715 vn_close(nd.ni_vp, FREAD, td->td_ucred, td); 1716 VFS_UNLOCK_GIANT(vfslocked); 1717 if (type == VREG) 1718 return (result); 1719 } 1720 } 1721 free(result, M_LINKER); 1722 return (NULL); 1723} 1724 1725#define INT_ALIGN(base, ptr) ptr = \ 1726 (base) + (((ptr) - (base) + sizeof(int) - 1) & ~(sizeof(int) - 1)) 1727 1728/* 1729 * Lookup KLD which contains requested module in the "linker.hints" file. If 1730 * version specification is available, then try to find the best KLD. 1731 * Otherwise just find the latest one. 1732 */ 1733static char * 1734linker_hints_lookup(const char *path, int pathlen, const char *modname, 1735 int modnamelen, struct mod_depend *verinfo) 1736{ 1737 struct thread *td = curthread; /* XXX */ 1738 struct ucred *cred = td ? td->td_ucred : NULL; 1739 struct nameidata nd; 1740 struct vattr vattr, mattr; 1741 u_char *hints = NULL; 1742 u_char *cp, *recptr, *bufend, *result, *best, *pathbuf, *sep; 1743 int error, ival, bestver, *intp, reclen, found, flags, clen, blen; 1744 int vfslocked = 0; 1745 1746 result = NULL; 1747 bestver = found = 0; 1748 1749 sep = (path[pathlen - 1] != '/') ? "/" : ""; 1750 reclen = imax(modnamelen, strlen(linker_hintfile)) + pathlen + 1751 strlen(sep) + 1; 1752 pathbuf = malloc(reclen, M_LINKER, M_WAITOK); 1753 snprintf(pathbuf, reclen, "%.*s%s%s", pathlen, path, sep, 1754 linker_hintfile); 1755 1756 NDINIT(&nd, LOOKUP, NOFOLLOW | MPSAFE, UIO_SYSSPACE, pathbuf, td); 1757 flags = FREAD; 1758 error = vn_open(&nd, &flags, 0, NULL); 1759 if (error) 1760 goto bad; 1761 vfslocked = NDHASGIANT(&nd); 1762 NDFREE(&nd, NDF_ONLY_PNBUF); 1763 if (nd.ni_vp->v_type != VREG) 1764 goto bad; 1765 best = cp = NULL; 1766 error = VOP_GETATTR(nd.ni_vp, &vattr, cred); 1767 if (error) 1768 goto bad; 1769 /* 1770 * XXX: we need to limit this number to some reasonable value 1771 */ 1772 if (vattr.va_size > 100 * 1024) { 1773 printf("hints file too large %ld\n", (long)vattr.va_size); 1774 goto bad; 1775 } 1776 hints = malloc(vattr.va_size, M_TEMP, M_WAITOK); 1777 if (hints == NULL) 1778 goto bad; 1779 error = vn_rdwr(UIO_READ, nd.ni_vp, (caddr_t)hints, vattr.va_size, 0, 1780 UIO_SYSSPACE, IO_NODELOCKED, cred, NOCRED, &reclen, td); 1781 if (error) 1782 goto bad; 1783 VOP_UNLOCK(nd.ni_vp, 0); 1784 vn_close(nd.ni_vp, FREAD, cred, td); 1785 VFS_UNLOCK_GIANT(vfslocked); 1786 nd.ni_vp = NULL; 1787 if (reclen != 0) { 1788 printf("can't read %d\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 VFS_UNLOCK_GIANT(vfslocked); 1855 } 1856 /* 1857 * If nothing found or hints is absent - fallback to the old 1858 * way by using "kldname[.ko]" as module name. 1859 */ 1860 if (!found && !bestver && result == NULL) 1861 result = linker_lookup_file(path, pathlen, modname, 1862 modnamelen, NULL); 1863 return (result); 1864} 1865 1866/* 1867 * Lookup KLD which contains requested module in the all directories. 1868 */ 1869static char * 1870linker_search_module(const char *modname, int modnamelen, 1871 struct mod_depend *verinfo) 1872{ 1873 char *cp, *ep, *result; 1874 1875 /* 1876 * traverse the linker path 1877 */ 1878 for (cp = linker_path; *cp; cp = ep + 1) { 1879 /* find the end of this component */ 1880 for (ep = cp; (*ep != 0) && (*ep != ';'); ep++); 1881 result = linker_hints_lookup(cp, ep - cp, modname, 1882 modnamelen, verinfo); 1883 if (result != NULL) 1884 return (result); 1885 if (*ep == 0) 1886 break; 1887 } 1888 return (NULL); 1889} 1890 1891/* 1892 * Search for module in all directories listed in the linker_path. 1893 */ 1894static char * 1895linker_search_kld(const char *name) 1896{ 1897 char *cp, *ep, *result; 1898 int len; 1899 1900 /* qualified at all? */ 1901 if (index(name, '/')) 1902 return (linker_strdup(name)); 1903 1904 /* traverse the linker path */ 1905 len = strlen(name); 1906 for (ep = linker_path; *ep; ep++) { 1907 cp = ep; 1908 /* find the end of this component */ 1909 for (; *ep != 0 && *ep != ';'; ep++); 1910 result = linker_lookup_file(cp, ep - cp, name, len, NULL); 1911 if (result != NULL) 1912 return (result); 1913 } 1914 return (NULL); 1915} 1916 1917static const char * 1918linker_basename(const char *path) 1919{ 1920 const char *filename; 1921 1922 filename = rindex(path, '/'); 1923 if (filename == NULL) 1924 return path; 1925 if (filename[1]) 1926 filename++; 1927 return (filename); 1928} 1929 1930#ifdef HWPMC_HOOKS 1931 1932struct hwpmc_context { 1933 int nobjects; 1934 int nmappings; 1935 struct pmckern_map_in *kobase; 1936}; 1937 1938static int 1939linker_hwpmc_list_object(linker_file_t lf, void *arg) 1940{ 1941 struct hwpmc_context *hc; 1942 1943 hc = arg; 1944 1945 /* If we run out of mappings, fail. */ 1946 if (hc->nobjects >= hc->nmappings) 1947 return (1); 1948 1949 /* Save the info for this linker file. */ 1950 hc->kobase[hc->nobjects].pm_file = lf->filename; 1951 hc->kobase[hc->nobjects].pm_address = (uintptr_t)lf->address; 1952 hc->nobjects++; 1953 return (0); 1954} 1955 1956/* 1957 * Inform hwpmc about the set of kernel modules currently loaded. 1958 */ 1959void * 1960linker_hwpmc_list_objects(void) 1961{ 1962 struct hwpmc_context hc; 1963 1964 hc.nmappings = 15; /* a reasonable default */ 1965 1966 retry: 1967 /* allocate nmappings+1 entries */ 1968 hc.kobase = malloc((hc.nmappings + 1) * sizeof(struct pmckern_map_in), 1969 M_LINKER, M_WAITOK | M_ZERO); 1970 1971 hc.nobjects = 0; 1972 if (linker_file_foreach(linker_hwpmc_list_object, &hc) != 0) { 1973 hc.nmappings = hc.nobjects; 1974 free(hc.kobase, M_LINKER); 1975 goto retry; 1976 } 1977 1978 KASSERT(hc.nobjects > 0, ("linker_hpwmc_list_objects: no kernel " 1979 "objects?")); 1980 1981 /* The last entry of the malloced area comprises of all zeros. */ 1982 KASSERT(hc.kobase[hc.nobjects].pm_file == NULL, 1983 ("linker_hwpmc_list_objects: last object not NULL")); 1984 1985 return ((void *)hc.kobase); 1986} 1987#endif 1988 1989/* 1990 * Find a file which contains given module and load it, if "parent" is not 1991 * NULL, register a reference to it. 1992 */ 1993static int 1994linker_load_module(const char *kldname, const char *modname, 1995 struct linker_file *parent, struct mod_depend *verinfo, 1996 struct linker_file **lfpp) 1997{ 1998 linker_file_t lfdep; 1999 const char *filename; 2000 char *pathname; 2001 int error; 2002 2003 KLD_LOCK_ASSERT(); 2004 if (modname == NULL) { 2005 /* 2006 * We have to load KLD 2007 */ 2008 KASSERT(verinfo == NULL, ("linker_load_module: verinfo" 2009 " is not NULL")); 2010 pathname = linker_search_kld(kldname); 2011 } else { 2012 if (modlist_lookup2(modname, verinfo) != NULL) 2013 return (EEXIST); 2014 if (kldname != NULL) 2015 pathname = linker_strdup(kldname); 2016 else if (rootvnode == NULL) 2017 pathname = NULL; 2018 else 2019 /* 2020 * Need to find a KLD with required module 2021 */ 2022 pathname = linker_search_module(modname, 2023 strlen(modname), verinfo); 2024 } 2025 if (pathname == NULL) 2026 return (ENOENT); 2027 2028 /* 2029 * Can't load more than one file with the same basename XXX: 2030 * Actually it should be possible to have multiple KLDs with 2031 * the same basename but different path because they can 2032 * provide different versions of the same modules. 2033 */ 2034 filename = linker_basename(pathname); 2035 if (linker_find_file_by_name(filename)) 2036 error = EEXIST; 2037 else do { 2038 error = linker_load_file(pathname, &lfdep); 2039 if (error) 2040 break; 2041 if (modname && verinfo && 2042 modlist_lookup2(modname, verinfo) == NULL) { 2043 linker_file_unload(lfdep, LINKER_UNLOAD_FORCE); 2044 error = ENOENT; 2045 break; 2046 } 2047 if (parent) { 2048 error = linker_file_add_dependency(parent, lfdep); 2049 if (error) 2050 break; 2051 } 2052 if (lfpp) 2053 *lfpp = lfdep; 2054 } while (0); 2055 free(pathname, M_LINKER); 2056 return (error); 2057} 2058 2059/* 2060 * This routine is responsible for finding dependencies of userland initiated 2061 * kldload(2)'s of files. 2062 */ 2063int 2064linker_load_dependencies(linker_file_t lf) 2065{ 2066 linker_file_t lfdep; 2067 struct mod_metadata **start, **stop, **mdp, **nmdp; 2068 struct mod_metadata *mp, *nmp; 2069 struct mod_depend *verinfo; 2070 modlist_t mod; 2071 const char *modname, *nmodname; 2072 int ver, error = 0, count; 2073 2074 /* 2075 * All files are dependant on /kernel. 2076 */ 2077 KLD_LOCK_ASSERT(); 2078 if (linker_kernel_file) { 2079 linker_kernel_file->refs++; 2080 error = linker_file_add_dependency(lf, linker_kernel_file); 2081 if (error) 2082 return (error); 2083 } 2084 if (linker_file_lookup_set(lf, MDT_SETNAME, &start, &stop, 2085 &count) != 0) 2086 return (0); 2087 for (mdp = start; mdp < stop; mdp++) { 2088 mp = *mdp; 2089 if (mp->md_type != MDT_VERSION) 2090 continue; 2091 modname = mp->md_cval; 2092 ver = ((struct mod_version *)mp->md_data)->mv_version; 2093 mod = modlist_lookup(modname, ver); 2094 if (mod != NULL) { 2095 printf("interface %s.%d already present in the KLD" 2096 " '%s'!\n", modname, ver, 2097 mod->container->filename); 2098 return (EEXIST); 2099 } 2100 } 2101 2102 for (mdp = start; mdp < stop; mdp++) { 2103 mp = *mdp; 2104 if (mp->md_type != MDT_DEPEND) 2105 continue; 2106 modname = mp->md_cval; 2107 verinfo = mp->md_data; 2108 nmodname = NULL; 2109 for (nmdp = start; nmdp < stop; nmdp++) { 2110 nmp = *nmdp; 2111 if (nmp->md_type != MDT_VERSION) 2112 continue; 2113 nmodname = nmp->md_cval; 2114 if (strcmp(modname, nmodname) == 0) 2115 break; 2116 } 2117 if (nmdp < stop)/* early exit, it's a self reference */ 2118 continue; 2119 mod = modlist_lookup2(modname, verinfo); 2120 if (mod) { /* woohoo, it's loaded already */ 2121 lfdep = mod->container; 2122 lfdep->refs++; 2123 error = linker_file_add_dependency(lf, lfdep); 2124 if (error) 2125 break; 2126 continue; 2127 } 2128 error = linker_load_module(NULL, modname, lf, verinfo, NULL); 2129 if (error) { 2130 printf("KLD %s: depends on %s - not available\n", 2131 lf->filename, modname); 2132 break; 2133 } 2134 } 2135 2136 if (error) 2137 return (error); 2138 linker_addmodules(lf, start, stop, 0); 2139 return (error); 2140} 2141 2142static int 2143sysctl_kern_function_list_iterate(const char *name, void *opaque) 2144{ 2145 struct sysctl_req *req; 2146 2147 req = opaque; 2148 return (SYSCTL_OUT(req, name, strlen(name) + 1)); 2149} 2150 2151/* 2152 * Export a nul-separated, double-nul-terminated list of all function names 2153 * in the kernel. 2154 */ 2155static int 2156sysctl_kern_function_list(SYSCTL_HANDLER_ARGS) 2157{ 2158 linker_file_t lf; 2159 int error; 2160 2161#ifdef MAC 2162 error = mac_kld_check_stat(req->td->td_ucred); 2163 if (error) 2164 return (error); 2165#endif 2166 error = sysctl_wire_old_buffer(req, 0); 2167 if (error != 0) 2168 return (error); 2169 KLD_LOCK(); 2170 TAILQ_FOREACH(lf, &linker_files, link) { 2171 error = LINKER_EACH_FUNCTION_NAME(lf, 2172 sysctl_kern_function_list_iterate, req); 2173 if (error) { 2174 KLD_UNLOCK(); 2175 return (error); 2176 } 2177 } 2178 KLD_UNLOCK(); 2179 return (SYSCTL_OUT(req, "", 1)); 2180} 2181 2182SYSCTL_PROC(_kern, OID_AUTO, function_list, CTLFLAG_RD, 2183 NULL, 0, sysctl_kern_function_list, "", "kernel function list"); 2184