kern_linker.c revision 188209
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 188209 2009-02-05 23:01:36Z jhb $"); 29 30#include "opt_ddb.h" 31#include "opt_hwpmc_hooks.h" 32#include "opt_mac.h" 33 34#include <sys/param.h> 35#include <sys/kernel.h> 36#include <sys/systm.h> 37#include <sys/malloc.h> 38#include <sys/sysproto.h> 39#include <sys/sysent.h> 40#include <sys/priv.h> 41#include <sys/proc.h> 42#include <sys/lock.h> 43#include <sys/mutex.h> 44#include <sys/sx.h> 45#include <sys/module.h> 46#include <sys/mount.h> 47#include <sys/linker.h> 48#include <sys/fcntl.h> 49#include <sys/libkern.h> 50#include <sys/namei.h> 51#include <sys/vnode.h> 52#include <sys/syscallsubr.h> 53#include <sys/sysctl.h> 54#include <sys/vimage.h> 55 56#include <security/mac/mac_framework.h> 57 58#include "linker_if.h" 59 60#ifdef HWPMC_HOOKS 61#include <sys/pmckern.h> 62#endif 63 64#ifdef KLD_DEBUG 65int kld_debug = 0; 66#endif 67 68#define KLD_LOCK() sx_xlock(&kld_sx) 69#define KLD_UNLOCK() sx_xunlock(&kld_sx) 70#define KLD_LOCKED() sx_xlocked(&kld_sx) 71#define KLD_LOCK_ASSERT() do { \ 72 if (!cold) \ 73 sx_assert(&kld_sx, SX_XLOCKED); \ 74} while (0) 75 76/* 77 * static char *linker_search_path(const char *name, struct mod_depend 78 * *verinfo); 79 */ 80static const char *linker_basename(const char *path); 81 82/* 83 * Find a currently loaded file given its filename. 84 */ 85static linker_file_t linker_find_file_by_name(const char* _filename); 86 87/* 88 * Find a currently loaded file given its file id. 89 */ 90static linker_file_t linker_find_file_by_id(int _fileid); 91 92/* Metadata from the static kernel */ 93SET_DECLARE(modmetadata_set, struct mod_metadata); 94 95MALLOC_DEFINE(M_LINKER, "linker", "kernel linker"); 96 97linker_file_t linker_kernel_file; 98 99static struct sx kld_sx; /* kernel linker lock */ 100 101/* 102 * Load counter used by clients to determine if a linker file has been 103 * re-loaded. This counter is incremented for each file load. 104 */ 105static int loadcnt; 106 107static linker_class_list_t classes; 108static linker_file_list_t linker_files; 109static int next_file_id = 1; 110static int linker_no_more_classes = 0; 111 112#define LINKER_GET_NEXT_FILE_ID(a) do { \ 113 linker_file_t lftmp; \ 114 \ 115 KLD_LOCK_ASSERT(); \ 116retry: \ 117 TAILQ_FOREACH(lftmp, &linker_files, link) { \ 118 if (next_file_id == lftmp->id) { \ 119 next_file_id++; \ 120 goto retry; \ 121 } \ 122 } \ 123 (a) = next_file_id; \ 124} while(0) 125 126 127/* XXX wrong name; we're looking at version provision tags here, not modules */ 128typedef TAILQ_HEAD(, modlist) modlisthead_t; 129struct modlist { 130 TAILQ_ENTRY(modlist) link; /* chain together all modules */ 131 linker_file_t container; 132 const char *name; 133 int version; 134}; 135typedef struct modlist *modlist_t; 136static modlisthead_t found_modules; 137 138static int linker_file_add_dependency(linker_file_t file, 139 linker_file_t dep); 140static caddr_t linker_file_lookup_symbol_internal(linker_file_t file, 141 const char* name, int deps); 142static int linker_load_module(const char *kldname, 143 const char *modname, struct linker_file *parent, 144 struct mod_depend *verinfo, struct linker_file **lfpp); 145static modlist_t modlist_lookup2(const char *name, struct mod_depend *verinfo); 146 147static char * 148linker_strdup(const char *str) 149{ 150 char *result; 151 152 if ((result = malloc((strlen(str) + 1), M_LINKER, M_WAITOK)) != NULL) 153 strcpy(result, str); 154 return (result); 155} 156 157static void 158linker_init(void *arg) 159{ 160 161 sx_init(&kld_sx, "kernel linker"); 162 TAILQ_INIT(&classes); 163 TAILQ_INIT(&linker_files); 164} 165 166SYSINIT(linker, SI_SUB_KLD, SI_ORDER_FIRST, linker_init, 0); 167 168static void 169linker_stop_class_add(void *arg) 170{ 171 172 linker_no_more_classes = 1; 173} 174 175SYSINIT(linker_class, SI_SUB_KLD, SI_ORDER_ANY, linker_stop_class_add, NULL); 176 177int 178linker_add_class(linker_class_t lc) 179{ 180 181 /* 182 * We disallow any class registration past SI_ORDER_ANY 183 * of SI_SUB_KLD. We bump the reference count to keep the 184 * ops from being freed. 185 */ 186 if (linker_no_more_classes == 1) 187 return (EPERM); 188 kobj_class_compile((kobj_class_t) lc); 189 ((kobj_class_t)lc)->refs++; /* XXX: kobj_mtx */ 190 TAILQ_INSERT_TAIL(&classes, lc, link); 191 return (0); 192} 193 194static void 195linker_file_sysinit(linker_file_t lf) 196{ 197 struct sysinit **start, **stop, **sipp, **xipp, *save; 198 199 KLD_DPF(FILE, ("linker_file_sysinit: calling SYSINITs for %s\n", 200 lf->filename)); 201 202 if (linker_file_lookup_set(lf, "sysinit_set", &start, &stop, NULL) != 0) 203 return; 204 /* 205 * Perform a bubble sort of the system initialization objects by 206 * their subsystem (primary key) and order (secondary key). 207 * 208 * Since some things care about execution order, this is the operation 209 * which ensures continued function. 210 */ 211 for (sipp = start; sipp < stop; sipp++) { 212 for (xipp = sipp + 1; xipp < stop; xipp++) { 213 if ((*sipp)->subsystem < (*xipp)->subsystem || 214 ((*sipp)->subsystem == (*xipp)->subsystem && 215 (*sipp)->order <= (*xipp)->order)) 216 continue; /* skip */ 217 save = *sipp; 218 *sipp = *xipp; 219 *xipp = save; 220 } 221 } 222 223 /* 224 * Traverse the (now) ordered list of system initialization tasks. 225 * Perform each task, and continue on to the next task. 226 */ 227 mtx_lock(&Giant); 228 for (sipp = start; sipp < stop; sipp++) { 229 if ((*sipp)->subsystem == SI_SUB_DUMMY) 230 continue; /* skip dummy task(s) */ 231 232 /* Call function */ 233 (*((*sipp)->func)) ((*sipp)->udata); 234 } 235 mtx_unlock(&Giant); 236} 237 238static void 239linker_file_sysuninit(linker_file_t lf) 240{ 241 struct sysinit **start, **stop, **sipp, **xipp, *save; 242 243 KLD_DPF(FILE, ("linker_file_sysuninit: calling SYSUNINITs for %s\n", 244 lf->filename)); 245 246 if (linker_file_lookup_set(lf, "sysuninit_set", &start, &stop, 247 NULL) != 0) 248 return; 249 250 /* 251 * Perform a reverse bubble sort of the system initialization objects 252 * by their subsystem (primary key) and order (secondary key). 253 * 254 * Since some things care about execution order, this is the operation 255 * which ensures continued function. 256 */ 257 for (sipp = start; sipp < stop; sipp++) { 258 for (xipp = sipp + 1; xipp < stop; xipp++) { 259 if ((*sipp)->subsystem > (*xipp)->subsystem || 260 ((*sipp)->subsystem == (*xipp)->subsystem && 261 (*sipp)->order >= (*xipp)->order)) 262 continue; /* skip */ 263 save = *sipp; 264 *sipp = *xipp; 265 *xipp = save; 266 } 267 } 268 269 /* 270 * Traverse the (now) ordered list of system initialization tasks. 271 * Perform each task, and continue on to the next task. 272 */ 273 mtx_lock(&Giant); 274 for (sipp = start; sipp < stop; sipp++) { 275 if ((*sipp)->subsystem == SI_SUB_DUMMY) 276 continue; /* skip dummy task(s) */ 277 278 /* Call function */ 279 (*((*sipp)->func)) ((*sipp)->udata); 280 } 281 mtx_unlock(&Giant); 282} 283 284static void 285linker_file_register_sysctls(linker_file_t lf) 286{ 287 struct sysctl_oid **start, **stop, **oidp; 288 289 KLD_DPF(FILE, 290 ("linker_file_register_sysctls: registering SYSCTLs for %s\n", 291 lf->filename)); 292 293 if (linker_file_lookup_set(lf, "sysctl_set", &start, &stop, NULL) != 0) 294 return; 295 296 mtx_lock(&Giant); 297 for (oidp = start; oidp < stop; oidp++) 298 sysctl_register_oid(*oidp); 299 mtx_unlock(&Giant); 300} 301 302static void 303linker_file_unregister_sysctls(linker_file_t lf) 304{ 305 struct sysctl_oid **start, **stop, **oidp; 306 307 KLD_DPF(FILE, ("linker_file_unregister_sysctls: registering SYSCTLs" 308 " for %s\n", lf->filename)); 309 310 if (linker_file_lookup_set(lf, "sysctl_set", &start, &stop, NULL) != 0) 311 return; 312 313 mtx_lock(&Giant); 314 for (oidp = start; oidp < stop; oidp++) 315 sysctl_unregister_oid(*oidp); 316 mtx_unlock(&Giant); 317} 318 319static int 320linker_file_register_modules(linker_file_t lf) 321{ 322 struct mod_metadata **start, **stop, **mdp; 323 const moduledata_t *moddata; 324 int first_error, error; 325 326 KLD_DPF(FILE, ("linker_file_register_modules: registering modules" 327 " in %s\n", lf->filename)); 328 329 if (linker_file_lookup_set(lf, "modmetadata_set", &start, 330 &stop, NULL) != 0) { 331 /* 332 * This fallback should be unnecessary, but if we get booted 333 * from boot2 instead of loader and we are missing our 334 * metadata then we have to try the best we can. 335 */ 336 if (lf == linker_kernel_file) { 337 start = SET_BEGIN(modmetadata_set); 338 stop = SET_LIMIT(modmetadata_set); 339 } else 340 return (0); 341 } 342 first_error = 0; 343 for (mdp = start; mdp < stop; mdp++) { 344 if ((*mdp)->md_type != MDT_MODULE) 345 continue; 346 moddata = (*mdp)->md_data; 347 KLD_DPF(FILE, ("Registering module %s in %s\n", 348 moddata->name, lf->filename)); 349 error = module_register(moddata, lf); 350 if (error) { 351 printf("Module %s failed to register: %d\n", 352 moddata->name, error); 353 if (first_error == 0) 354 first_error = error; 355 } 356 } 357 return (first_error); 358} 359 360static void 361linker_init_kernel_modules(void) 362{ 363 364 linker_file_register_modules(linker_kernel_file); 365} 366 367SYSINIT(linker_kernel, SI_SUB_KLD, SI_ORDER_ANY, linker_init_kernel_modules, 368 0); 369 370static int 371linker_load_file(const char *filename, linker_file_t *result) 372{ 373 linker_class_t lc; 374 linker_file_t lf; 375 int foundfile, error; 376 377 /* Refuse to load modules if securelevel raised */ 378 if (securelevel > 0) 379 return (EPERM); 380 381 KLD_LOCK_ASSERT(); 382 lf = linker_find_file_by_name(filename); 383 if (lf) { 384 KLD_DPF(FILE, ("linker_load_file: file %s is already loaded," 385 " incrementing refs\n", filename)); 386 *result = lf; 387 lf->refs++; 388 return (0); 389 } 390 foundfile = 0; 391 error = 0; 392 393 /* 394 * We do not need to protect (lock) classes here because there is 395 * no class registration past startup (SI_SUB_KLD, SI_ORDER_ANY) 396 * and there is no class deregistration mechanism at this time. 397 */ 398 TAILQ_FOREACH(lc, &classes, link) { 399 KLD_DPF(FILE, ("linker_load_file: trying to load %s\n", 400 filename)); 401 error = LINKER_LOAD_FILE(lc, filename, &lf); 402 /* 403 * If we got something other than ENOENT, then it exists but 404 * we cannot load it for some other reason. 405 */ 406 if (error != ENOENT) 407 foundfile = 1; 408 if (lf) { 409 error = linker_file_register_modules(lf); 410 if (error == EEXIST) { 411 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 412 return (error); 413 } 414 KLD_UNLOCK(); 415 linker_file_register_sysctls(lf); 416 linker_file_sysinit(lf); 417 KLD_LOCK(); 418 lf->flags |= LINKER_FILE_LINKED; 419 *result = lf; 420 return (0); 421 } 422 } 423 /* 424 * Less than ideal, but tells the user whether it failed to load or 425 * the module was not found. 426 */ 427 if (foundfile) { 428 /* 429 * Format not recognized or otherwise unloadable. 430 * When loading a module that is statically built into 431 * the kernel EEXIST percolates back up as the return 432 * value. Preserve this so that apps like sysinstall 433 * can recognize this special case and not post bogus 434 * dialog boxes. 435 */ 436 if (error != EEXIST) 437 error = ENOEXEC; 438 } else 439 error = ENOENT; /* Nothing found */ 440 return (error); 441} 442 443int 444linker_reference_module(const char *modname, struct mod_depend *verinfo, 445 linker_file_t *result) 446{ 447 modlist_t mod; 448 int error; 449 450 KLD_LOCK(); 451 if ((mod = modlist_lookup2(modname, verinfo)) != NULL) { 452 *result = mod->container; 453 (*result)->refs++; 454 KLD_UNLOCK(); 455 return (0); 456 } 457 458 error = linker_load_module(NULL, modname, NULL, verinfo, result); 459 KLD_UNLOCK(); 460 return (error); 461} 462 463int 464linker_release_module(const char *modname, struct mod_depend *verinfo, 465 linker_file_t lf) 466{ 467 modlist_t mod; 468 int error; 469 470 KLD_LOCK(); 471 if (lf == NULL) { 472 KASSERT(modname != NULL, 473 ("linker_release_module: no file or name")); 474 mod = modlist_lookup2(modname, verinfo); 475 if (mod == NULL) { 476 KLD_UNLOCK(); 477 return (ESRCH); 478 } 479 lf = mod->container; 480 } else 481 KASSERT(modname == NULL && verinfo == NULL, 482 ("linker_release_module: both file and name")); 483 error = linker_file_unload(lf, LINKER_UNLOAD_NORMAL); 484 KLD_UNLOCK(); 485 return (error); 486} 487 488static linker_file_t 489linker_find_file_by_name(const char *filename) 490{ 491 linker_file_t lf; 492 char *koname; 493 494 koname = malloc(strlen(filename) + 4, M_LINKER, M_WAITOK); 495 sprintf(koname, "%s.ko", filename); 496 497 KLD_LOCK_ASSERT(); 498 TAILQ_FOREACH(lf, &linker_files, link) { 499 if (strcmp(lf->filename, koname) == 0) 500 break; 501 if (strcmp(lf->filename, filename) == 0) 502 break; 503 } 504 free(koname, M_LINKER); 505 return (lf); 506} 507 508static linker_file_t 509linker_find_file_by_id(int fileid) 510{ 511 linker_file_t lf; 512 513 KLD_LOCK_ASSERT(); 514 TAILQ_FOREACH(lf, &linker_files, link) 515 if (lf->id == fileid && lf->flags & LINKER_FILE_LINKED) 516 break; 517 return (lf); 518} 519 520int 521linker_file_foreach(linker_predicate_t *predicate, void *context) 522{ 523 linker_file_t lf; 524 int retval = 0; 525 526 KLD_LOCK(); 527 TAILQ_FOREACH(lf, &linker_files, link) { 528 retval = predicate(lf, context); 529 if (retval != 0) 530 break; 531 } 532 KLD_UNLOCK(); 533 return (retval); 534} 535 536linker_file_t 537linker_make_file(const char *pathname, linker_class_t lc) 538{ 539 linker_file_t lf; 540 const char *filename; 541 542 KLD_LOCK_ASSERT(); 543 filename = linker_basename(pathname); 544 545 KLD_DPF(FILE, ("linker_make_file: new file, filename='%s' for pathname='%s'\n", filename, pathname)); 546 lf = (linker_file_t)kobj_create((kobj_class_t)lc, M_LINKER, M_WAITOK); 547 if (lf == NULL) 548 return (NULL); 549 lf->refs = 1; 550 lf->userrefs = 0; 551 lf->flags = 0; 552 lf->filename = linker_strdup(filename); 553 lf->pathname = linker_strdup(pathname); 554 LINKER_GET_NEXT_FILE_ID(lf->id); 555 lf->ndeps = 0; 556 lf->deps = NULL; 557 lf->loadcnt = ++loadcnt; 558 lf->sdt_probes = NULL; 559 lf->sdt_nprobes = 0; 560 STAILQ_INIT(&lf->common); 561 TAILQ_INIT(&lf->modules); 562 TAILQ_INSERT_TAIL(&linker_files, lf, link); 563 return (lf); 564} 565 566int 567linker_file_unload(linker_file_t file, int flags) 568{ 569 module_t mod, next; 570 modlist_t ml, nextml; 571 struct common_symbol *cp; 572 int error, i; 573 574 /* Refuse to unload modules if securelevel raised. */ 575 if (securelevel > 0) 576 return (EPERM); 577 578 KLD_LOCK_ASSERT(); 579 KLD_DPF(FILE, ("linker_file_unload: lf->refs=%d\n", file->refs)); 580 581 /* Easy case of just dropping a reference. */ 582 if (file->refs > 1) { 583 file->refs--; 584 return (0); 585 } 586 587 KLD_DPF(FILE, ("linker_file_unload: file is unloading," 588 " informing modules\n")); 589 590 /* 591 * Quiesce all the modules to give them a chance to veto the unload. 592 */ 593 MOD_SLOCK; 594 for (mod = TAILQ_FIRST(&file->modules); mod; 595 mod = module_getfnext(mod)) { 596 597 error = module_quiesce(mod); 598 if (error != 0 && flags != LINKER_UNLOAD_FORCE) { 599 KLD_DPF(FILE, ("linker_file_unload: module %s" 600 " vetoed unload\n", module_getname(mod))); 601 /* 602 * XXX: Do we need to tell all the quiesced modules 603 * that they can resume work now via a new module 604 * event? 605 */ 606 MOD_SUNLOCK; 607 return (error); 608 } 609 } 610 MOD_SUNLOCK; 611 612 /* 613 * Inform any modules associated with this file that they are 614 * being be unloaded. 615 */ 616 MOD_XLOCK; 617 for (mod = TAILQ_FIRST(&file->modules); mod; mod = next) { 618 next = module_getfnext(mod); 619 MOD_XUNLOCK; 620 621 /* 622 * Give the module a chance to veto the unload. 623 */ 624 if ((error = module_unload(mod)) != 0) { 625 KLD_DPF(FILE, ("linker_file_unload: module %s" 626 " failed unload\n", mod)); 627 return (error); 628 } 629 MOD_XLOCK; 630 module_release(mod); 631 } 632 MOD_XUNLOCK; 633 634 TAILQ_FOREACH_SAFE(ml, &found_modules, link, nextml) { 635 if (ml->container == file) { 636 TAILQ_REMOVE(&found_modules, ml, link); 637 free(ml, M_LINKER); 638 } 639 } 640 641 /* 642 * Don't try to run SYSUNINITs if we are unloaded due to a 643 * link error. 644 */ 645 if (file->flags & LINKER_FILE_LINKED) { 646 file->flags &= ~LINKER_FILE_LINKED; 647 KLD_UNLOCK(); 648 linker_file_sysuninit(file); 649 linker_file_unregister_sysctls(file); 650 KLD_LOCK(); 651 } 652 TAILQ_REMOVE(&linker_files, file, link); 653 654 if (file->deps) { 655 for (i = 0; i < file->ndeps; i++) 656 linker_file_unload(file->deps[i], flags); 657 free(file->deps, M_LINKER); 658 file->deps = NULL; 659 } 660 while ((cp = STAILQ_FIRST(&file->common)) != NULL) { 661 STAILQ_REMOVE_HEAD(&file->common, link); 662 free(cp, M_LINKER); 663 } 664 665 LINKER_UNLOAD(file); 666 if (file->filename) { 667 free(file->filename, M_LINKER); 668 file->filename = NULL; 669 } 670 if (file->pathname) { 671 free(file->pathname, M_LINKER); 672 file->pathname = NULL; 673 } 674 kobj_delete((kobj_t) file, M_LINKER); 675 return (0); 676} 677 678int 679linker_ctf_get(linker_file_t file, linker_ctf_t *lc) 680{ 681 return (LINKER_CTF_GET(file, lc)); 682} 683 684static int 685linker_file_add_dependency(linker_file_t file, linker_file_t dep) 686{ 687 linker_file_t *newdeps; 688 689 KLD_LOCK_ASSERT(); 690 newdeps = malloc((file->ndeps + 1) * sizeof(linker_file_t *), 691 M_LINKER, M_WAITOK | M_ZERO); 692 if (newdeps == NULL) 693 return (ENOMEM); 694 695 if (file->deps) { 696 bcopy(file->deps, newdeps, 697 file->ndeps * sizeof(linker_file_t *)); 698 free(file->deps, M_LINKER); 699 } 700 file->deps = newdeps; 701 file->deps[file->ndeps] = dep; 702 file->ndeps++; 703 return (0); 704} 705 706/* 707 * Locate a linker set and its contents. This is a helper function to avoid 708 * linker_if.h exposure elsewhere. Note: firstp and lastp are really void **. 709 * This function is used in this file so we can avoid having lots of (void **) 710 * casts. 711 */ 712int 713linker_file_lookup_set(linker_file_t file, const char *name, 714 void *firstp, void *lastp, int *countp) 715{ 716 int error, locked; 717 718 locked = KLD_LOCKED(); 719 if (!locked) 720 KLD_LOCK(); 721 error = LINKER_LOOKUP_SET(file, name, firstp, lastp, countp); 722 if (!locked) 723 KLD_UNLOCK(); 724 return (error); 725} 726 727/* 728 * List all functions in a file. 729 */ 730int 731linker_file_function_listall(linker_file_t lf, 732 linker_function_nameval_callback_t callback_func, void *arg) 733{ 734 return (LINKER_EACH_FUNCTION_NAMEVAL(lf, callback_func, arg)); 735} 736 737caddr_t 738linker_file_lookup_symbol(linker_file_t file, const char *name, int deps) 739{ 740 caddr_t sym; 741 int locked; 742 743 locked = KLD_LOCKED(); 744 if (!locked) 745 KLD_LOCK(); 746 sym = linker_file_lookup_symbol_internal(file, name, deps); 747 if (!locked) 748 KLD_UNLOCK(); 749 return (sym); 750} 751 752static caddr_t 753linker_file_lookup_symbol_internal(linker_file_t file, const char *name, 754 int deps) 755{ 756 c_linker_sym_t sym; 757 linker_symval_t symval; 758 caddr_t address; 759 size_t common_size = 0; 760 int i; 761 762 KLD_LOCK_ASSERT(); 763 KLD_DPF(SYM, ("linker_file_lookup_symbol: file=%p, name=%s, deps=%d\n", 764 file, name, deps)); 765 766 if (LINKER_LOOKUP_SYMBOL(file, name, &sym) == 0) { 767 LINKER_SYMBOL_VALUES(file, sym, &symval); 768 if (symval.value == 0) 769 /* 770 * For commons, first look them up in the 771 * dependencies and only allocate space if not found 772 * there. 773 */ 774 common_size = symval.size; 775 else { 776 KLD_DPF(SYM, ("linker_file_lookup_symbol: symbol" 777 ".value=%p\n", symval.value)); 778 return (symval.value); 779 } 780 } 781 if (deps) { 782 for (i = 0; i < file->ndeps; i++) { 783 address = linker_file_lookup_symbol_internal( 784 file->deps[i], name, 0); 785 if (address) { 786 KLD_DPF(SYM, ("linker_file_lookup_symbol:" 787 " deps value=%p\n", address)); 788 return (address); 789 } 790 } 791 } 792 if (common_size > 0) { 793 /* 794 * This is a common symbol which was not found in the 795 * dependencies. We maintain a simple common symbol table in 796 * the file object. 797 */ 798 struct common_symbol *cp; 799 800 STAILQ_FOREACH(cp, &file->common, link) { 801 if (strcmp(cp->name, name) == 0) { 802 KLD_DPF(SYM, ("linker_file_lookup_symbol:" 803 " old common value=%p\n", cp->address)); 804 return (cp->address); 805 } 806 } 807 /* 808 * Round the symbol size up to align. 809 */ 810 common_size = (common_size + sizeof(int) - 1) & -sizeof(int); 811 cp = malloc(sizeof(struct common_symbol) 812 + common_size + strlen(name) + 1, M_LINKER, 813 M_WAITOK | M_ZERO); 814 cp->address = (caddr_t)(cp + 1); 815 cp->name = cp->address + common_size; 816 strcpy(cp->name, name); 817 bzero(cp->address, common_size); 818 STAILQ_INSERT_TAIL(&file->common, cp, link); 819 820 KLD_DPF(SYM, ("linker_file_lookup_symbol: new common" 821 " value=%p\n", cp->address)); 822 return (cp->address); 823 } 824 KLD_DPF(SYM, ("linker_file_lookup_symbol: fail\n")); 825 return (0); 826} 827 828/* 829 * Both DDB and stack(9) rely on the kernel linker to provide forward and 830 * backward lookup of symbols. However, DDB and sometimes stack(9) need to 831 * do this in a lockfree manner. We provide a set of internal helper 832 * routines to perform these operations without locks, and then wrappers that 833 * optionally lock. 834 * 835 * linker_debug_lookup() is ifdef DDB as currently it's only used by DDB. 836 */ 837#ifdef DDB 838static int 839linker_debug_lookup(const char *symstr, c_linker_sym_t *sym) 840{ 841 linker_file_t lf; 842 843 TAILQ_FOREACH(lf, &linker_files, link) { 844 if (LINKER_LOOKUP_SYMBOL(lf, symstr, sym) == 0) 845 return (0); 846 } 847 return (ENOENT); 848} 849#endif 850 851static int 852linker_debug_search_symbol(caddr_t value, c_linker_sym_t *sym, long *diffp) 853{ 854 linker_file_t lf; 855 c_linker_sym_t best, es; 856 u_long diff, bestdiff, off; 857 858 best = 0; 859 off = (uintptr_t)value; 860 bestdiff = off; 861 TAILQ_FOREACH(lf, &linker_files, link) { 862 if (LINKER_SEARCH_SYMBOL(lf, value, &es, &diff) != 0) 863 continue; 864 if (es != 0 && diff < bestdiff) { 865 best = es; 866 bestdiff = diff; 867 } 868 if (bestdiff == 0) 869 break; 870 } 871 if (best) { 872 *sym = best; 873 *diffp = bestdiff; 874 return (0); 875 } else { 876 *sym = 0; 877 *diffp = off; 878 return (ENOENT); 879 } 880} 881 882static int 883linker_debug_symbol_values(c_linker_sym_t sym, linker_symval_t *symval) 884{ 885 linker_file_t lf; 886 887 TAILQ_FOREACH(lf, &linker_files, link) { 888 if (LINKER_SYMBOL_VALUES(lf, sym, symval) == 0) 889 return (0); 890 } 891 return (ENOENT); 892} 893 894static int 895linker_debug_search_symbol_name(caddr_t value, char *buf, u_int buflen, 896 long *offset) 897{ 898 linker_symval_t symval; 899 c_linker_sym_t sym; 900 int error; 901 902 *offset = 0; 903 error = linker_debug_search_symbol(value, &sym, offset); 904 if (error) 905 return (error); 906 error = linker_debug_symbol_values(sym, &symval); 907 if (error) 908 return (error); 909 strlcpy(buf, symval.name, buflen); 910 return (0); 911} 912 913#ifdef DDB 914/* 915 * DDB Helpers. DDB has to look across multiple files with their own symbol 916 * tables and string tables. 917 * 918 * Note that we do not obey list locking protocols here. We really don't need 919 * DDB to hang because somebody's got the lock held. We'll take the chance 920 * that the files list is inconsistant instead. 921 */ 922int 923linker_ddb_lookup(const char *symstr, c_linker_sym_t *sym) 924{ 925 926 return (linker_debug_lookup(symstr, sym)); 927} 928 929int 930linker_ddb_search_symbol(caddr_t value, c_linker_sym_t *sym, long *diffp) 931{ 932 933 return (linker_debug_search_symbol(value, sym, diffp)); 934} 935 936int 937linker_ddb_symbol_values(c_linker_sym_t sym, linker_symval_t *symval) 938{ 939 940 return (linker_debug_symbol_values(sym, symval)); 941} 942 943int 944linker_ddb_search_symbol_name(caddr_t value, char *buf, u_int buflen, 945 long *offset) 946{ 947 948 return (linker_debug_search_symbol_name(value, buf, buflen, offset)); 949} 950#endif 951 952/* 953 * stack(9) helper for non-debugging environemnts. Unlike DDB helpers, we do 954 * obey locking protocols, and offer a significantly less complex interface. 955 */ 956int 957linker_search_symbol_name(caddr_t value, char *buf, u_int buflen, 958 long *offset) 959{ 960 int error; 961 962 KLD_LOCK(); 963 error = linker_debug_search_symbol_name(value, buf, buflen, offset); 964 KLD_UNLOCK(); 965 return (error); 966} 967 968/* 969 * Syscalls. 970 */ 971int 972kern_kldload(struct thread *td, const char *file, int *fileid) 973{ 974#ifdef HWPMC_HOOKS 975 struct pmckern_map_in pkm; 976#endif 977 const char *kldname, *modname; 978 linker_file_t lf; 979 int error; 980 981 if ((error = securelevel_gt(td->td_ucred, 0)) != 0) 982 return (error); 983 984 if ((error = priv_check(td, PRIV_KLD_LOAD)) != 0) 985 return (error); 986 987 /* 988 * If file does not contain a qualified name or any dot in it 989 * (kldname.ko, or kldname.ver.ko) treat it as an interface 990 * name. 991 */ 992 if (index(file, '/') || index(file, '.')) { 993 kldname = file; 994 modname = NULL; 995 } else { 996 kldname = NULL; 997 modname = file; 998 } 999 1000 KLD_LOCK(); 1001 error = linker_load_module(kldname, modname, NULL, NULL, &lf); 1002 if (error) 1003 goto unlock; 1004#ifdef HWPMC_HOOKS 1005 pkm.pm_file = lf->filename; 1006 pkm.pm_address = (uintptr_t) lf->address; 1007 PMC_CALL_HOOK(td, PMC_FN_KLD_LOAD, (void *) &pkm); 1008#endif 1009 lf->userrefs++; 1010 if (fileid != NULL) 1011 *fileid = lf->id; 1012unlock: 1013 KLD_UNLOCK(); 1014 return (error); 1015} 1016 1017int 1018kldload(struct thread *td, struct kldload_args *uap) 1019{ 1020 char *pathname = NULL; 1021 int error, fileid; 1022 1023 td->td_retval[0] = -1; 1024 1025 pathname = malloc(MAXPATHLEN, M_TEMP, M_WAITOK); 1026 error = copyinstr(uap->file, pathname, MAXPATHLEN, NULL); 1027 if (error == 0) { 1028 error = kern_kldload(td, pathname, &fileid); 1029 if (error == 0) 1030 td->td_retval[0] = fileid; 1031 } 1032 free(pathname, M_TEMP); 1033 return (error); 1034} 1035 1036int 1037kern_kldunload(struct thread *td, int fileid, int flags) 1038{ 1039#ifdef HWPMC_HOOKS 1040 struct pmckern_map_out pkm; 1041#endif 1042 linker_file_t lf; 1043 int error = 0; 1044 1045 if ((error = securelevel_gt(td->td_ucred, 0)) != 0) 1046 return (error); 1047 1048 if ((error = priv_check(td, PRIV_KLD_UNLOAD)) != 0) 1049 return (error); 1050 1051 KLD_LOCK(); 1052 lf = linker_find_file_by_id(fileid); 1053 if (lf) { 1054 KLD_DPF(FILE, ("kldunload: lf->userrefs=%d\n", lf->userrefs)); 1055 1056 /* Check if there are DTrace probes enabled on this file. */ 1057 if (lf->nenabled > 0) { 1058 printf("kldunload: attempt to unload file that has" 1059 " DTrace probes enabled\n"); 1060 error = EBUSY; 1061 } else if (lf->userrefs == 0) { 1062 /* 1063 * XXX: maybe LINKER_UNLOAD_FORCE should override ? 1064 */ 1065 printf("kldunload: attempt to unload file that was" 1066 " loaded by the kernel\n"); 1067 error = EBUSY; 1068 } else { 1069#ifdef HWPMC_HOOKS 1070 /* Save data needed by hwpmc(4) before unloading. */ 1071 pkm.pm_address = (uintptr_t) lf->address; 1072 pkm.pm_size = lf->size; 1073#endif 1074 lf->userrefs--; 1075 error = linker_file_unload(lf, flags); 1076 if (error) 1077 lf->userrefs++; 1078 } 1079 } else 1080 error = ENOENT; 1081 1082#ifdef HWPMC_HOOKS 1083 if (error == 0) 1084 PMC_CALL_HOOK(td, PMC_FN_KLD_UNLOAD, (void *) &pkm); 1085#endif 1086 KLD_UNLOCK(); 1087 return (error); 1088} 1089 1090int 1091kldunload(struct thread *td, struct kldunload_args *uap) 1092{ 1093 1094 return (kern_kldunload(td, uap->fileid, LINKER_UNLOAD_NORMAL)); 1095} 1096 1097int 1098kldunloadf(struct thread *td, struct kldunloadf_args *uap) 1099{ 1100 1101 if (uap->flags != LINKER_UNLOAD_NORMAL && 1102 uap->flags != LINKER_UNLOAD_FORCE) 1103 return (EINVAL); 1104 return (kern_kldunload(td, uap->fileid, uap->flags)); 1105} 1106 1107int 1108kldfind(struct thread *td, struct kldfind_args *uap) 1109{ 1110 char *pathname; 1111 const char *filename; 1112 linker_file_t lf; 1113 int error; 1114 1115#ifdef MAC 1116 error = mac_kld_check_stat(td->td_ucred); 1117 if (error) 1118 return (error); 1119#endif 1120 1121 td->td_retval[0] = -1; 1122 1123 pathname = malloc(MAXPATHLEN, M_TEMP, M_WAITOK); 1124 if ((error = copyinstr(uap->file, pathname, MAXPATHLEN, NULL)) != 0) 1125 goto out; 1126 1127 filename = linker_basename(pathname); 1128 KLD_LOCK(); 1129 lf = linker_find_file_by_name(filename); 1130 if (lf) 1131 td->td_retval[0] = lf->id; 1132 else 1133 error = ENOENT; 1134 KLD_UNLOCK(); 1135out: 1136 free(pathname, M_TEMP); 1137 return (error); 1138} 1139 1140int 1141kldnext(struct thread *td, struct kldnext_args *uap) 1142{ 1143 linker_file_t lf; 1144 int error = 0; 1145 1146#ifdef MAC 1147 error = mac_kld_check_stat(td->td_ucred); 1148 if (error) 1149 return (error); 1150#endif 1151 1152 KLD_LOCK(); 1153 if (uap->fileid == 0) 1154 lf = TAILQ_FIRST(&linker_files); 1155 else { 1156 lf = linker_find_file_by_id(uap->fileid); 1157 if (lf == NULL) { 1158 error = ENOENT; 1159 goto out; 1160 } 1161 lf = TAILQ_NEXT(lf, link); 1162 } 1163 1164 /* Skip partially loaded files. */ 1165 while (lf != NULL && !(lf->flags & LINKER_FILE_LINKED)) 1166 lf = TAILQ_NEXT(lf, link); 1167 1168 if (lf) 1169 td->td_retval[0] = lf->id; 1170 else 1171 td->td_retval[0] = 0; 1172out: 1173 KLD_UNLOCK(); 1174 return (error); 1175} 1176 1177int 1178kldstat(struct thread *td, struct kldstat_args *uap) 1179{ 1180 struct kld_file_stat stat; 1181 linker_file_t lf; 1182 int error, namelen, version, version_num; 1183 1184 /* 1185 * Check the version of the user's structure. 1186 */ 1187 if ((error = copyin(&uap->stat->version, &version, sizeof(version))) != 0) 1188 return (error); 1189 if (version == sizeof(struct kld_file_stat_1)) 1190 version_num = 1; 1191 else if (version == sizeof(struct kld_file_stat)) 1192 version_num = 2; 1193 else 1194 return (EINVAL); 1195 1196#ifdef MAC 1197 error = mac_kld_check_stat(td->td_ucred); 1198 if (error) 1199 return (error); 1200#endif 1201 1202 KLD_LOCK(); 1203 lf = linker_find_file_by_id(uap->fileid); 1204 if (lf == NULL) { 1205 KLD_UNLOCK(); 1206 return (ENOENT); 1207 } 1208 1209 /* Version 1 fields: */ 1210 namelen = strlen(lf->filename) + 1; 1211 if (namelen > MAXPATHLEN) 1212 namelen = MAXPATHLEN; 1213 bcopy(lf->filename, &stat.name[0], namelen); 1214 stat.refs = lf->refs; 1215 stat.id = lf->id; 1216 stat.address = lf->address; 1217 stat.size = lf->size; 1218 if (version_num > 1) { 1219 /* Version 2 fields: */ 1220 namelen = strlen(lf->pathname) + 1; 1221 if (namelen > MAXPATHLEN) 1222 namelen = MAXPATHLEN; 1223 bcopy(lf->pathname, &stat.pathname[0], namelen); 1224 } 1225 KLD_UNLOCK(); 1226 1227 td->td_retval[0] = 0; 1228 1229 return (copyout(&stat, uap->stat, version)); 1230} 1231 1232int 1233kldfirstmod(struct thread *td, struct kldfirstmod_args *uap) 1234{ 1235 linker_file_t lf; 1236 module_t mp; 1237 int error = 0; 1238 1239#ifdef MAC 1240 error = mac_kld_check_stat(td->td_ucred); 1241 if (error) 1242 return (error); 1243#endif 1244 1245 KLD_LOCK(); 1246 lf = linker_find_file_by_id(uap->fileid); 1247 if (lf) { 1248 MOD_SLOCK; 1249 mp = TAILQ_FIRST(&lf->modules); 1250 if (mp != NULL) 1251 td->td_retval[0] = module_getid(mp); 1252 else 1253 td->td_retval[0] = 0; 1254 MOD_SUNLOCK; 1255 } else 1256 error = ENOENT; 1257 KLD_UNLOCK(); 1258 return (error); 1259} 1260 1261int 1262kldsym(struct thread *td, struct kldsym_args *uap) 1263{ 1264 char *symstr = NULL; 1265 c_linker_sym_t sym; 1266 linker_symval_t symval; 1267 linker_file_t lf; 1268 struct kld_sym_lookup lookup; 1269 int error = 0; 1270 1271#ifdef MAC 1272 error = mac_kld_check_stat(td->td_ucred); 1273 if (error) 1274 return (error); 1275#endif 1276 1277 if ((error = copyin(uap->data, &lookup, sizeof(lookup))) != 0) 1278 return (error); 1279 if (lookup.version != sizeof(lookup) || 1280 uap->cmd != KLDSYM_LOOKUP) 1281 return (EINVAL); 1282 symstr = malloc(MAXPATHLEN, M_TEMP, M_WAITOK); 1283 if ((error = copyinstr(lookup.symname, symstr, MAXPATHLEN, NULL)) != 0) 1284 goto out; 1285 KLD_LOCK(); 1286 if (uap->fileid != 0) { 1287 lf = linker_find_file_by_id(uap->fileid); 1288 if (lf == NULL) 1289 error = ENOENT; 1290 else if (LINKER_LOOKUP_SYMBOL(lf, symstr, &sym) == 0 && 1291 LINKER_SYMBOL_VALUES(lf, sym, &symval) == 0) { 1292 lookup.symvalue = (uintptr_t) symval.value; 1293 lookup.symsize = symval.size; 1294 error = copyout(&lookup, uap->data, sizeof(lookup)); 1295 } else 1296 error = ENOENT; 1297 } else { 1298 TAILQ_FOREACH(lf, &linker_files, link) { 1299 if (LINKER_LOOKUP_SYMBOL(lf, symstr, &sym) == 0 && 1300 LINKER_SYMBOL_VALUES(lf, sym, &symval) == 0) { 1301 lookup.symvalue = (uintptr_t)symval.value; 1302 lookup.symsize = symval.size; 1303 error = copyout(&lookup, uap->data, 1304 sizeof(lookup)); 1305 break; 1306 } 1307 } 1308#ifndef VIMAGE_GLOBALS 1309 /* 1310 * If the symbol is not found in global namespace, 1311 * try to look it up in the current vimage namespace. 1312 */ 1313 if (lf == NULL) { 1314 CURVNET_SET(TD_TO_VNET(td)); 1315 error = vi_symlookup(&lookup, symstr); 1316 CURVNET_RESTORE(); 1317 if (error == 0) 1318 error = copyout(&lookup, uap->data, 1319 sizeof(lookup)); 1320 } 1321#else 1322 if (lf == NULL) 1323 error = ENOENT; 1324#endif 1325 } 1326 KLD_UNLOCK(); 1327out: 1328 free(symstr, M_TEMP); 1329 return (error); 1330} 1331 1332/* 1333 * Preloaded module support 1334 */ 1335 1336static modlist_t 1337modlist_lookup(const char *name, int ver) 1338{ 1339 modlist_t mod; 1340 1341 TAILQ_FOREACH(mod, &found_modules, link) { 1342 if (strcmp(mod->name, name) == 0 && 1343 (ver == 0 || mod->version == ver)) 1344 return (mod); 1345 } 1346 return (NULL); 1347} 1348 1349static modlist_t 1350modlist_lookup2(const char *name, struct mod_depend *verinfo) 1351{ 1352 modlist_t mod, bestmod; 1353 int ver; 1354 1355 if (verinfo == NULL) 1356 return (modlist_lookup(name, 0)); 1357 bestmod = NULL; 1358 TAILQ_FOREACH(mod, &found_modules, link) { 1359 if (strcmp(mod->name, name) != 0) 1360 continue; 1361 ver = mod->version; 1362 if (ver == verinfo->md_ver_preferred) 1363 return (mod); 1364 if (ver >= verinfo->md_ver_minimum && 1365 ver <= verinfo->md_ver_maximum && 1366 (bestmod == NULL || ver > bestmod->version)) 1367 bestmod = mod; 1368 } 1369 return (bestmod); 1370} 1371 1372static modlist_t 1373modlist_newmodule(const char *modname, int version, linker_file_t container) 1374{ 1375 modlist_t mod; 1376 1377 mod = malloc(sizeof(struct modlist), M_LINKER, M_NOWAIT | M_ZERO); 1378 if (mod == NULL) 1379 panic("no memory for module list"); 1380 mod->container = container; 1381 mod->name = modname; 1382 mod->version = version; 1383 TAILQ_INSERT_TAIL(&found_modules, mod, link); 1384 return (mod); 1385} 1386 1387static void 1388linker_addmodules(linker_file_t lf, struct mod_metadata **start, 1389 struct mod_metadata **stop, int preload) 1390{ 1391 struct mod_metadata *mp, **mdp; 1392 const char *modname; 1393 int ver; 1394 1395 for (mdp = start; mdp < stop; mdp++) { 1396 mp = *mdp; 1397 if (mp->md_type != MDT_VERSION) 1398 continue; 1399 modname = mp->md_cval; 1400 ver = ((struct mod_version *)mp->md_data)->mv_version; 1401 if (modlist_lookup(modname, ver) != NULL) { 1402 printf("module %s already present!\n", modname); 1403 /* XXX what can we do? this is a build error. :-( */ 1404 continue; 1405 } 1406 modlist_newmodule(modname, ver, lf); 1407 } 1408} 1409 1410static void 1411linker_preload(void *arg) 1412{ 1413 caddr_t modptr; 1414 const char *modname, *nmodname; 1415 char *modtype; 1416 linker_file_t lf, nlf; 1417 linker_class_t lc; 1418 int error; 1419 linker_file_list_t loaded_files; 1420 linker_file_list_t depended_files; 1421 struct mod_metadata *mp, *nmp; 1422 struct mod_metadata **start, **stop, **mdp, **nmdp; 1423 struct mod_depend *verinfo; 1424 int nver; 1425 int resolves; 1426 modlist_t mod; 1427 struct sysinit **si_start, **si_stop; 1428 1429 TAILQ_INIT(&loaded_files); 1430 TAILQ_INIT(&depended_files); 1431 TAILQ_INIT(&found_modules); 1432 error = 0; 1433 1434 modptr = NULL; 1435 while ((modptr = preload_search_next_name(modptr)) != NULL) { 1436 modname = (char *)preload_search_info(modptr, MODINFO_NAME); 1437 modtype = (char *)preload_search_info(modptr, MODINFO_TYPE); 1438 if (modname == NULL) { 1439 printf("Preloaded module at %p does not have a" 1440 " name!\n", modptr); 1441 continue; 1442 } 1443 if (modtype == NULL) { 1444 printf("Preloaded module at %p does not have a type!\n", 1445 modptr); 1446 continue; 1447 } 1448 if (bootverbose) 1449 printf("Preloaded %s \"%s\" at %p.\n", modtype, modname, 1450 modptr); 1451 lf = NULL; 1452 TAILQ_FOREACH(lc, &classes, link) { 1453 error = LINKER_LINK_PRELOAD(lc, modname, &lf); 1454 if (!error) 1455 break; 1456 lf = NULL; 1457 } 1458 if (lf) 1459 TAILQ_INSERT_TAIL(&loaded_files, lf, loaded); 1460 } 1461 1462 /* 1463 * First get a list of stuff in the kernel. 1464 */ 1465 if (linker_file_lookup_set(linker_kernel_file, MDT_SETNAME, &start, 1466 &stop, NULL) == 0) 1467 linker_addmodules(linker_kernel_file, start, stop, 1); 1468 1469 /* 1470 * This is a once-off kinky bubble sort to resolve relocation 1471 * dependency requirements. 1472 */ 1473restart: 1474 TAILQ_FOREACH(lf, &loaded_files, loaded) { 1475 error = linker_file_lookup_set(lf, MDT_SETNAME, &start, 1476 &stop, NULL); 1477 /* 1478 * First, look to see if we would successfully link with this 1479 * stuff. 1480 */ 1481 resolves = 1; /* unless we know otherwise */ 1482 if (!error) { 1483 for (mdp = start; mdp < stop; mdp++) { 1484 mp = *mdp; 1485 if (mp->md_type != MDT_DEPEND) 1486 continue; 1487 modname = mp->md_cval; 1488 verinfo = mp->md_data; 1489 for (nmdp = start; nmdp < stop; nmdp++) { 1490 nmp = *nmdp; 1491 if (nmp->md_type != MDT_VERSION) 1492 continue; 1493 nmodname = nmp->md_cval; 1494 if (strcmp(modname, nmodname) == 0) 1495 break; 1496 } 1497 if (nmdp < stop) /* it's a self reference */ 1498 continue; 1499 1500 /* 1501 * ok, the module isn't here yet, we 1502 * are not finished 1503 */ 1504 if (modlist_lookup2(modname, verinfo) == NULL) 1505 resolves = 0; 1506 } 1507 } 1508 /* 1509 * OK, if we found our modules, we can link. So, "provide" 1510 * the modules inside and add it to the end of the link order 1511 * list. 1512 */ 1513 if (resolves) { 1514 if (!error) { 1515 for (mdp = start; mdp < stop; mdp++) { 1516 mp = *mdp; 1517 if (mp->md_type != MDT_VERSION) 1518 continue; 1519 modname = mp->md_cval; 1520 nver = ((struct mod_version *) 1521 mp->md_data)->mv_version; 1522 if (modlist_lookup(modname, 1523 nver) != NULL) { 1524 printf("module %s already" 1525 " present!\n", modname); 1526 TAILQ_REMOVE(&loaded_files, 1527 lf, loaded); 1528 linker_file_unload(lf, 1529 LINKER_UNLOAD_FORCE); 1530 /* we changed tailq next ptr */ 1531 goto restart; 1532 } 1533 modlist_newmodule(modname, nver, lf); 1534 } 1535 } 1536 TAILQ_REMOVE(&loaded_files, lf, loaded); 1537 TAILQ_INSERT_TAIL(&depended_files, lf, loaded); 1538 /* 1539 * Since we provided modules, we need to restart the 1540 * sort so that the previous files that depend on us 1541 * have a chance. Also, we've busted the tailq next 1542 * pointer with the REMOVE. 1543 */ 1544 goto restart; 1545 } 1546 } 1547 1548 /* 1549 * At this point, we check to see what could not be resolved.. 1550 */ 1551 while ((lf = TAILQ_FIRST(&loaded_files)) != NULL) { 1552 TAILQ_REMOVE(&loaded_files, lf, loaded); 1553 printf("KLD file %s is missing dependencies\n", lf->filename); 1554 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 1555 } 1556 1557 /* 1558 * We made it. Finish off the linking in the order we determined. 1559 */ 1560 TAILQ_FOREACH_SAFE(lf, &depended_files, loaded, nlf) { 1561 if (linker_kernel_file) { 1562 linker_kernel_file->refs++; 1563 error = linker_file_add_dependency(lf, 1564 linker_kernel_file); 1565 if (error) 1566 panic("cannot add dependency"); 1567 } 1568 lf->userrefs++; /* so we can (try to) kldunload it */ 1569 error = linker_file_lookup_set(lf, MDT_SETNAME, &start, 1570 &stop, NULL); 1571 if (!error) { 1572 for (mdp = start; mdp < stop; mdp++) { 1573 mp = *mdp; 1574 if (mp->md_type != MDT_DEPEND) 1575 continue; 1576 modname = mp->md_cval; 1577 verinfo = mp->md_data; 1578 mod = modlist_lookup2(modname, verinfo); 1579 /* Don't count self-dependencies */ 1580 if (lf == mod->container) 1581 continue; 1582 mod->container->refs++; 1583 error = linker_file_add_dependency(lf, 1584 mod->container); 1585 if (error) 1586 panic("cannot add dependency"); 1587 } 1588 } 1589 /* 1590 * Now do relocation etc using the symbol search paths 1591 * established by the dependencies 1592 */ 1593 error = LINKER_LINK_PRELOAD_FINISH(lf); 1594 if (error) { 1595 TAILQ_REMOVE(&depended_files, lf, loaded); 1596 printf("KLD file %s - could not finalize loading\n", 1597 lf->filename); 1598 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 1599 continue; 1600 } 1601 linker_file_register_modules(lf); 1602 if (linker_file_lookup_set(lf, "sysinit_set", &si_start, 1603 &si_stop, NULL) == 0) 1604 sysinit_add(si_start, si_stop); 1605 linker_file_register_sysctls(lf); 1606 lf->flags |= LINKER_FILE_LINKED; 1607 } 1608 /* woohoo! we made it! */ 1609} 1610 1611SYSINIT(preload, SI_SUB_KLD, SI_ORDER_MIDDLE, linker_preload, 0); 1612 1613/* 1614 * Search for a not-loaded module by name. 1615 * 1616 * Modules may be found in the following locations: 1617 * 1618 * - preloaded (result is just the module name) - on disk (result is full path 1619 * to module) 1620 * 1621 * If the module name is qualified in any way (contains path, etc.) the we 1622 * simply return a copy of it. 1623 * 1624 * The search path can be manipulated via sysctl. Note that we use the ';' 1625 * character as a separator to be consistent with the bootloader. 1626 */ 1627 1628static char linker_hintfile[] = "linker.hints"; 1629static char linker_path[MAXPATHLEN] = "/boot/kernel;/boot/modules"; 1630 1631SYSCTL_STRING(_kern, OID_AUTO, module_path, CTLFLAG_RW, linker_path, 1632 sizeof(linker_path), "module load search path"); 1633 1634TUNABLE_STR("module_path", linker_path, sizeof(linker_path)); 1635 1636static char *linker_ext_list[] = { 1637 "", 1638 ".ko", 1639 NULL 1640}; 1641 1642/* 1643 * Check if file actually exists either with or without extension listed in 1644 * the linker_ext_list. (probably should be generic for the rest of the 1645 * kernel) 1646 */ 1647static char * 1648linker_lookup_file(const char *path, int pathlen, const char *name, 1649 int namelen, struct vattr *vap) 1650{ 1651 struct nameidata nd; 1652 struct thread *td = curthread; /* XXX */ 1653 char *result, **cpp, *sep; 1654 int error, len, extlen, reclen, flags, vfslocked; 1655 enum vtype type; 1656 1657 extlen = 0; 1658 for (cpp = linker_ext_list; *cpp; cpp++) { 1659 len = strlen(*cpp); 1660 if (len > extlen) 1661 extlen = len; 1662 } 1663 extlen++; /* trailing '\0' */ 1664 sep = (path[pathlen - 1] != '/') ? "/" : ""; 1665 1666 reclen = pathlen + strlen(sep) + namelen + extlen + 1; 1667 result = malloc(reclen, M_LINKER, M_WAITOK); 1668 for (cpp = linker_ext_list; *cpp; cpp++) { 1669 snprintf(result, reclen, "%.*s%s%.*s%s", pathlen, path, sep, 1670 namelen, name, *cpp); 1671 /* 1672 * Attempt to open the file, and return the path if 1673 * we succeed and it's a regular file. 1674 */ 1675 NDINIT(&nd, LOOKUP, FOLLOW | MPSAFE, UIO_SYSSPACE, result, td); 1676 flags = FREAD; 1677 error = vn_open(&nd, &flags, 0, NULL); 1678 if (error == 0) { 1679 vfslocked = NDHASGIANT(&nd); 1680 NDFREE(&nd, NDF_ONLY_PNBUF); 1681 type = nd.ni_vp->v_type; 1682 if (vap) 1683 VOP_GETATTR(nd.ni_vp, vap, td->td_ucred); 1684 VOP_UNLOCK(nd.ni_vp, 0); 1685 vn_close(nd.ni_vp, FREAD, td->td_ucred, td); 1686 VFS_UNLOCK_GIANT(vfslocked); 1687 if (type == VREG) 1688 return (result); 1689 } 1690 } 1691 free(result, M_LINKER); 1692 return (NULL); 1693} 1694 1695#define INT_ALIGN(base, ptr) ptr = \ 1696 (base) + (((ptr) - (base) + sizeof(int) - 1) & ~(sizeof(int) - 1)) 1697 1698/* 1699 * Lookup KLD which contains requested module in the "linker.hints" file. If 1700 * version specification is available, then try to find the best KLD. 1701 * Otherwise just find the latest one. 1702 */ 1703static char * 1704linker_hints_lookup(const char *path, int pathlen, const char *modname, 1705 int modnamelen, struct mod_depend *verinfo) 1706{ 1707 struct thread *td = curthread; /* XXX */ 1708 struct ucred *cred = td ? td->td_ucred : NULL; 1709 struct nameidata nd; 1710 struct vattr vattr, mattr; 1711 u_char *hints = NULL; 1712 u_char *cp, *recptr, *bufend, *result, *best, *pathbuf, *sep; 1713 int error, ival, bestver, *intp, reclen, found, flags, clen, blen; 1714 int vfslocked = 0; 1715 1716 result = NULL; 1717 bestver = found = 0; 1718 1719 sep = (path[pathlen - 1] != '/') ? "/" : ""; 1720 reclen = imax(modnamelen, strlen(linker_hintfile)) + pathlen + 1721 strlen(sep) + 1; 1722 pathbuf = malloc(reclen, M_LINKER, M_WAITOK); 1723 snprintf(pathbuf, reclen, "%.*s%s%s", pathlen, path, sep, 1724 linker_hintfile); 1725 1726 NDINIT(&nd, LOOKUP, NOFOLLOW | MPSAFE, UIO_SYSSPACE, pathbuf, td); 1727 flags = FREAD; 1728 error = vn_open(&nd, &flags, 0, NULL); 1729 if (error) 1730 goto bad; 1731 vfslocked = NDHASGIANT(&nd); 1732 NDFREE(&nd, NDF_ONLY_PNBUF); 1733 if (nd.ni_vp->v_type != VREG) 1734 goto bad; 1735 best = cp = NULL; 1736 error = VOP_GETATTR(nd.ni_vp, &vattr, cred); 1737 if (error) 1738 goto bad; 1739 /* 1740 * XXX: we need to limit this number to some reasonable value 1741 */ 1742 if (vattr.va_size > 100 * 1024) { 1743 printf("hints file too large %ld\n", (long)vattr.va_size); 1744 goto bad; 1745 } 1746 hints = malloc(vattr.va_size, M_TEMP, M_WAITOK); 1747 if (hints == NULL) 1748 goto bad; 1749 error = vn_rdwr(UIO_READ, nd.ni_vp, (caddr_t)hints, vattr.va_size, 0, 1750 UIO_SYSSPACE, IO_NODELOCKED, cred, NOCRED, &reclen, td); 1751 if (error) 1752 goto bad; 1753 VOP_UNLOCK(nd.ni_vp, 0); 1754 vn_close(nd.ni_vp, FREAD, cred, td); 1755 VFS_UNLOCK_GIANT(vfslocked); 1756 nd.ni_vp = NULL; 1757 if (reclen != 0) { 1758 printf("can't read %d\n", reclen); 1759 goto bad; 1760 } 1761 intp = (int *)hints; 1762 ival = *intp++; 1763 if (ival != LINKER_HINTS_VERSION) { 1764 printf("hints file version mismatch %d\n", ival); 1765 goto bad; 1766 } 1767 bufend = hints + vattr.va_size; 1768 recptr = (u_char *)intp; 1769 clen = blen = 0; 1770 while (recptr < bufend && !found) { 1771 intp = (int *)recptr; 1772 reclen = *intp++; 1773 ival = *intp++; 1774 cp = (char *)intp; 1775 switch (ival) { 1776 case MDT_VERSION: 1777 clen = *cp++; 1778 if (clen != modnamelen || bcmp(cp, modname, clen) != 0) 1779 break; 1780 cp += clen; 1781 INT_ALIGN(hints, cp); 1782 ival = *(int *)cp; 1783 cp += sizeof(int); 1784 clen = *cp++; 1785 if (verinfo == NULL || 1786 ival == verinfo->md_ver_preferred) { 1787 found = 1; 1788 break; 1789 } 1790 if (ival >= verinfo->md_ver_minimum && 1791 ival <= verinfo->md_ver_maximum && 1792 ival > bestver) { 1793 bestver = ival; 1794 best = cp; 1795 blen = clen; 1796 } 1797 break; 1798 default: 1799 break; 1800 } 1801 recptr += reclen + sizeof(int); 1802 } 1803 /* 1804 * Finally check if KLD is in the place 1805 */ 1806 if (found) 1807 result = linker_lookup_file(path, pathlen, cp, clen, &mattr); 1808 else if (best) 1809 result = linker_lookup_file(path, pathlen, best, blen, &mattr); 1810 1811 /* 1812 * KLD is newer than hints file. What we should do now? 1813 */ 1814 if (result && timespeccmp(&mattr.va_mtime, &vattr.va_mtime, >)) 1815 printf("warning: KLD '%s' is newer than the linker.hints" 1816 " file\n", result); 1817bad: 1818 free(pathbuf, M_LINKER); 1819 if (hints) 1820 free(hints, M_TEMP); 1821 if (nd.ni_vp != NULL) { 1822 VOP_UNLOCK(nd.ni_vp, 0); 1823 vn_close(nd.ni_vp, FREAD, cred, td); 1824 VFS_UNLOCK_GIANT(vfslocked); 1825 } 1826 /* 1827 * If nothing found or hints is absent - fallback to the old 1828 * way by using "kldname[.ko]" as module name. 1829 */ 1830 if (!found && !bestver && result == NULL) 1831 result = linker_lookup_file(path, pathlen, modname, 1832 modnamelen, NULL); 1833 return (result); 1834} 1835 1836/* 1837 * Lookup KLD which contains requested module in the all directories. 1838 */ 1839static char * 1840linker_search_module(const char *modname, int modnamelen, 1841 struct mod_depend *verinfo) 1842{ 1843 char *cp, *ep, *result; 1844 1845 /* 1846 * traverse the linker path 1847 */ 1848 for (cp = linker_path; *cp; cp = ep + 1) { 1849 /* find the end of this component */ 1850 for (ep = cp; (*ep != 0) && (*ep != ';'); ep++); 1851 result = linker_hints_lookup(cp, ep - cp, modname, 1852 modnamelen, verinfo); 1853 if (result != NULL) 1854 return (result); 1855 if (*ep == 0) 1856 break; 1857 } 1858 return (NULL); 1859} 1860 1861/* 1862 * Search for module in all directories listed in the linker_path. 1863 */ 1864static char * 1865linker_search_kld(const char *name) 1866{ 1867 char *cp, *ep, *result; 1868 int len; 1869 1870 /* qualified at all? */ 1871 if (index(name, '/')) 1872 return (linker_strdup(name)); 1873 1874 /* traverse the linker path */ 1875 len = strlen(name); 1876 for (ep = linker_path; *ep; ep++) { 1877 cp = ep; 1878 /* find the end of this component */ 1879 for (; *ep != 0 && *ep != ';'; ep++); 1880 result = linker_lookup_file(cp, ep - cp, name, len, NULL); 1881 if (result != NULL) 1882 return (result); 1883 } 1884 return (NULL); 1885} 1886 1887static const char * 1888linker_basename(const char *path) 1889{ 1890 const char *filename; 1891 1892 filename = rindex(path, '/'); 1893 if (filename == NULL) 1894 return path; 1895 if (filename[1]) 1896 filename++; 1897 return (filename); 1898} 1899 1900#ifdef HWPMC_HOOKS 1901 1902struct hwpmc_context { 1903 int nobjects; 1904 int nmappings; 1905 struct pmckern_map_in *kobase; 1906}; 1907 1908static int 1909linker_hwpmc_list_object(linker_file_t lf, void *arg) 1910{ 1911 struct hwpmc_context *hc; 1912 1913 hc = arg; 1914 1915 /* If we run out of mappings, fail. */ 1916 if (hc->nobjects >= hc->nmappings) 1917 return (1); 1918 1919 /* Save the info for this linker file. */ 1920 hc->kobase[hc->nobjects].pm_file = lf->filename; 1921 hc->kobase[hc->nobjects].pm_address = (uintptr_t)lf->address; 1922 hc->nobjects++; 1923 return (0); 1924} 1925 1926/* 1927 * Inform hwpmc about the set of kernel modules currently loaded. 1928 */ 1929void * 1930linker_hwpmc_list_objects(void) 1931{ 1932 struct hwpmc_context hc; 1933 1934 hc.nmappings = 15; /* a reasonable default */ 1935 1936 retry: 1937 /* allocate nmappings+1 entries */ 1938 hc.kobase = malloc((hc.nmappings + 1) * sizeof(struct pmckern_map_in), 1939 M_LINKER, M_WAITOK | M_ZERO); 1940 1941 hc.nobjects = 0; 1942 if (linker_file_foreach(linker_hwpmc_list_object, &hc) != 0) { 1943 hc.nmappings = hc.nobjects; 1944 free(hc.kobase, M_LINKER); 1945 goto retry; 1946 } 1947 1948 KASSERT(hc.nobjects > 0, ("linker_hpwmc_list_objects: no kernel " 1949 "objects?")); 1950 1951 /* The last entry of the malloced area comprises of all zeros. */ 1952 KASSERT(hc.kobase[hc.nobjects].pm_file == NULL, 1953 ("linker_hwpmc_list_objects: last object not NULL")); 1954 1955 return ((void *)hc.kobase); 1956} 1957#endif 1958 1959/* 1960 * Find a file which contains given module and load it, if "parent" is not 1961 * NULL, register a reference to it. 1962 */ 1963static int 1964linker_load_module(const char *kldname, const char *modname, 1965 struct linker_file *parent, struct mod_depend *verinfo, 1966 struct linker_file **lfpp) 1967{ 1968 linker_file_t lfdep; 1969 const char *filename; 1970 char *pathname; 1971 int error; 1972 1973 KLD_LOCK_ASSERT(); 1974 if (modname == NULL) { 1975 /* 1976 * We have to load KLD 1977 */ 1978 KASSERT(verinfo == NULL, ("linker_load_module: verinfo" 1979 " is not NULL")); 1980 pathname = linker_search_kld(kldname); 1981 } else { 1982 if (modlist_lookup2(modname, verinfo) != NULL) 1983 return (EEXIST); 1984 if (kldname != NULL) 1985 pathname = linker_strdup(kldname); 1986 else if (rootvnode == NULL) 1987 pathname = NULL; 1988 else 1989 /* 1990 * Need to find a KLD with required module 1991 */ 1992 pathname = linker_search_module(modname, 1993 strlen(modname), verinfo); 1994 } 1995 if (pathname == NULL) 1996 return (ENOENT); 1997 1998 /* 1999 * Can't load more than one file with the same basename XXX: 2000 * Actually it should be possible to have multiple KLDs with 2001 * the same basename but different path because they can 2002 * provide different versions of the same modules. 2003 */ 2004 filename = linker_basename(pathname); 2005 if (linker_find_file_by_name(filename)) 2006 error = EEXIST; 2007 else do { 2008 error = linker_load_file(pathname, &lfdep); 2009 if (error) 2010 break; 2011 if (modname && verinfo && 2012 modlist_lookup2(modname, verinfo) == NULL) { 2013 linker_file_unload(lfdep, LINKER_UNLOAD_FORCE); 2014 error = ENOENT; 2015 break; 2016 } 2017 if (parent) { 2018 error = linker_file_add_dependency(parent, lfdep); 2019 if (error) 2020 break; 2021 } 2022 if (lfpp) 2023 *lfpp = lfdep; 2024 } while (0); 2025 free(pathname, M_LINKER); 2026 return (error); 2027} 2028 2029/* 2030 * This routine is responsible for finding dependencies of userland initiated 2031 * kldload(2)'s of files. 2032 */ 2033int 2034linker_load_dependencies(linker_file_t lf) 2035{ 2036 linker_file_t lfdep; 2037 struct mod_metadata **start, **stop, **mdp, **nmdp; 2038 struct mod_metadata *mp, *nmp; 2039 struct mod_depend *verinfo; 2040 modlist_t mod; 2041 const char *modname, *nmodname; 2042 int ver, error = 0, count; 2043 2044 /* 2045 * All files are dependant on /kernel. 2046 */ 2047 KLD_LOCK_ASSERT(); 2048 if (linker_kernel_file) { 2049 linker_kernel_file->refs++; 2050 error = linker_file_add_dependency(lf, linker_kernel_file); 2051 if (error) 2052 return (error); 2053 } 2054 if (linker_file_lookup_set(lf, MDT_SETNAME, &start, &stop, 2055 &count) != 0) 2056 return (0); 2057 for (mdp = start; mdp < stop; mdp++) { 2058 mp = *mdp; 2059 if (mp->md_type != MDT_VERSION) 2060 continue; 2061 modname = mp->md_cval; 2062 ver = ((struct mod_version *)mp->md_data)->mv_version; 2063 mod = modlist_lookup(modname, ver); 2064 if (mod != NULL) { 2065 printf("interface %s.%d already present in the KLD" 2066 " '%s'!\n", modname, ver, 2067 mod->container->filename); 2068 return (EEXIST); 2069 } 2070 } 2071 2072 for (mdp = start; mdp < stop; mdp++) { 2073 mp = *mdp; 2074 if (mp->md_type != MDT_DEPEND) 2075 continue; 2076 modname = mp->md_cval; 2077 verinfo = mp->md_data; 2078 nmodname = NULL; 2079 for (nmdp = start; nmdp < stop; nmdp++) { 2080 nmp = *nmdp; 2081 if (nmp->md_type != MDT_VERSION) 2082 continue; 2083 nmodname = nmp->md_cval; 2084 if (strcmp(modname, nmodname) == 0) 2085 break; 2086 } 2087 if (nmdp < stop)/* early exit, it's a self reference */ 2088 continue; 2089 mod = modlist_lookup2(modname, verinfo); 2090 if (mod) { /* woohoo, it's loaded already */ 2091 lfdep = mod->container; 2092 lfdep->refs++; 2093 error = linker_file_add_dependency(lf, lfdep); 2094 if (error) 2095 break; 2096 continue; 2097 } 2098 error = linker_load_module(NULL, modname, lf, verinfo, NULL); 2099 if (error) { 2100 printf("KLD %s: depends on %s - not available\n", 2101 lf->filename, modname); 2102 break; 2103 } 2104 } 2105 2106 if (error) 2107 return (error); 2108 linker_addmodules(lf, start, stop, 0); 2109 return (error); 2110} 2111 2112static int 2113sysctl_kern_function_list_iterate(const char *name, void *opaque) 2114{ 2115 struct sysctl_req *req; 2116 2117 req = opaque; 2118 return (SYSCTL_OUT(req, name, strlen(name) + 1)); 2119} 2120 2121/* 2122 * Export a nul-separated, double-nul-terminated list of all function names 2123 * in the kernel. 2124 */ 2125static int 2126sysctl_kern_function_list(SYSCTL_HANDLER_ARGS) 2127{ 2128 linker_file_t lf; 2129 int error; 2130 2131#ifdef MAC 2132 error = mac_kld_check_stat(req->td->td_ucred); 2133 if (error) 2134 return (error); 2135#endif 2136 error = sysctl_wire_old_buffer(req, 0); 2137 if (error != 0) 2138 return (error); 2139 KLD_LOCK(); 2140 TAILQ_FOREACH(lf, &linker_files, link) { 2141 error = LINKER_EACH_FUNCTION_NAME(lf, 2142 sysctl_kern_function_list_iterate, req); 2143 if (error) { 2144 KLD_UNLOCK(); 2145 return (error); 2146 } 2147 } 2148 KLD_UNLOCK(); 2149 return (SYSCTL_OUT(req, "", 1)); 2150} 2151 2152SYSCTL_PROC(_kern, OID_AUTO, function_list, CTLFLAG_RD, 2153 NULL, 0, sysctl_kern_function_list, "", "kernel function list"); 2154