kern_linker.c revision 82749
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 * $FreeBSD: head/sys/kern/kern_linker.c 82749 2001-09-01 19:04:37Z dillon $ 27 */ 28 29#include "opt_ddb.h" 30 31#include <sys/param.h> 32#include <sys/kernel.h> 33#include <sys/systm.h> 34#include <sys/malloc.h> 35#include <sys/sysproto.h> 36#include <sys/sysent.h> 37#include <sys/proc.h> 38#include <sys/lock.h> 39#include <sys/mutex.h> 40#include <sys/module.h> 41#include <sys/linker.h> 42#include <sys/fcntl.h> 43#include <sys/libkern.h> 44#include <sys/namei.h> 45#include <sys/vnode.h> 46#include <sys/sysctl.h> 47 48 49#include "linker_if.h" 50 51#ifdef KLD_DEBUG 52int kld_debug = 0; 53#endif 54 55static char *linker_search_path(const char *name); 56static const char *linker_basename(const char* path); 57 58/* Metadata from the static kernel */ 59SET_DECLARE(modmetadata_set, struct mod_metadata); 60 61MALLOC_DEFINE(M_LINKER, "linker", "kernel linker"); 62 63linker_file_t linker_kernel_file; 64 65static struct lock lock; /* lock for the file list */ 66static linker_class_list_t classes; 67static linker_file_list_t linker_files; 68static int next_file_id = 1; 69 70/* XXX wrong name; we're looking at version provision tags here, not modules */ 71typedef TAILQ_HEAD(, modlist) modlisthead_t; 72struct modlist { 73 TAILQ_ENTRY(modlist) link; /* chain together all modules */ 74 linker_file_t container; 75 const char *name; 76 int version; 77}; 78typedef struct modlist *modlist_t; 79static modlisthead_t found_modules; 80 81static char * 82linker_strdup(const char *str) 83{ 84 char *result; 85 86 if ((result = malloc((strlen(str) + 1), M_LINKER, M_WAITOK)) != NULL) 87 strcpy(result, str); 88 return(result); 89} 90 91static void 92linker_init(void* arg) 93{ 94 lockinit(&lock, PVM, "klink", 0, 0); 95 TAILQ_INIT(&classes); 96 TAILQ_INIT(&linker_files); 97} 98 99SYSINIT(linker, SI_SUB_KLD, SI_ORDER_FIRST, linker_init, 0); 100 101int 102linker_add_class(linker_class_t lc) 103{ 104 kobj_class_compile((kobj_class_t) lc); 105 TAILQ_INSERT_TAIL(&classes, lc, link); 106 return 0; 107} 108 109static void 110linker_file_sysinit(linker_file_t lf) 111{ 112 struct sysinit** start, ** stop; 113 struct sysinit** sipp; 114 struct sysinit** xipp; 115 struct sysinit* save; 116 117 KLD_DPF(FILE, ("linker_file_sysinit: calling SYSINITs for %s\n", 118 lf->filename)); 119 120 if (linker_file_lookup_set(lf, "sysinit_set", &start, &stop, NULL) != 0) 121 return; 122 /* 123 * Perform a bubble sort of the system initialization objects by 124 * their subsystem (primary key) and order (secondary key). 125 * 126 * Since some things care about execution order, this is the 127 * operation which ensures continued function. 128 */ 129 for (sipp = start; sipp < stop; sipp++) { 130 for (xipp = sipp + 1; xipp < stop; xipp++) { 131 if ((*sipp)->subsystem < (*xipp)->subsystem || 132 ((*sipp)->subsystem == (*xipp)->subsystem && 133 (*sipp)->order <= (*xipp)->order)) 134 continue; /* skip*/ 135 save = *sipp; 136 *sipp = *xipp; 137 *xipp = save; 138 } 139 } 140 141 142 /* 143 * Traverse the (now) ordered list of system initialization tasks. 144 * Perform each task, and continue on to the next task. 145 */ 146 for (sipp = start; sipp < stop; sipp++) { 147 if ((*sipp)->subsystem == SI_SUB_DUMMY) 148 continue; /* skip dummy task(s)*/ 149 150 /* Call function */ 151 (*((*sipp)->func))((*sipp)->udata); 152 } 153} 154 155static void 156linker_file_sysuninit(linker_file_t lf) 157{ 158 struct sysinit** start, ** stop; 159 struct sysinit** sipp; 160 struct sysinit** xipp; 161 struct sysinit* save; 162 163 KLD_DPF(FILE, ("linker_file_sysuninit: calling SYSUNINITs for %s\n", 164 lf->filename)); 165 166 if (linker_file_lookup_set(lf, "sysuninit_set", &start, &stop, NULL) != 0) 167 return; 168 169 /* 170 * Perform a reverse bubble sort of the system initialization objects 171 * by their subsystem (primary key) and order (secondary key). 172 * 173 * Since some things care about execution order, this is the 174 * operation which ensures continued function. 175 */ 176 for (sipp = start; sipp < stop; sipp++) { 177 for (xipp = sipp + 1; xipp < stop; xipp++) { 178 if ((*sipp)->subsystem > (*xipp)->subsystem || 179 ((*sipp)->subsystem == (*xipp)->subsystem && 180 (*sipp)->order >= (*xipp)->order)) 181 continue; /* skip*/ 182 save = *sipp; 183 *sipp = *xipp; 184 *xipp = save; 185 } 186 } 187 188 /* 189 * Traverse the (now) ordered list of system initialization tasks. 190 * Perform each task, and continue on to the next task. 191 */ 192 for (sipp = start; sipp < stop; sipp++) { 193 if ((*sipp)->subsystem == SI_SUB_DUMMY) 194 continue; /* skip dummy task(s)*/ 195 196 /* Call function */ 197 (*((*sipp)->func))((*sipp)->udata); 198 } 199} 200 201static void 202linker_file_register_sysctls(linker_file_t lf) 203{ 204 struct sysctl_oid **start, **stop, **oidp; 205 206 KLD_DPF(FILE, ("linker_file_register_sysctls: registering SYSCTLs for %s\n", 207 lf->filename)); 208 209 if (linker_file_lookup_set(lf, "sysctl_set", &start, &stop, NULL) != 0) 210 return; 211 212 for (oidp = start; oidp < stop; oidp++) 213 sysctl_register_oid(*oidp); 214} 215 216static void 217linker_file_unregister_sysctls(linker_file_t lf) 218{ 219 struct sysctl_oid **start, **stop, **oidp; 220 221 KLD_DPF(FILE, ("linker_file_unregister_sysctls: registering SYSCTLs for %s\n", 222 lf->filename)); 223 224 if (linker_file_lookup_set(lf, "sysctl_set", &start, &stop, NULL) != 0) 225 return; 226 227 for (oidp = start; oidp < stop; oidp++) 228 sysctl_unregister_oid(*oidp); 229} 230 231static int 232linker_file_register_modules(linker_file_t lf) 233{ 234 int error; 235 struct mod_metadata **start, **stop; 236 struct mod_metadata **mdp; 237 const moduledata_t *moddata; 238 239 KLD_DPF(FILE, ("linker_file_register_modules: registering modules in %s\n", 240 lf->filename)); 241 242 if (linker_file_lookup_set(lf, "modmetadata_set", &start, &stop, 0) != 0) { 243 /* 244 * This fallback should be unnecessary, but if we get booted from 245 * boot2 instead of loader and we are missing our metadata then 246 * we have to try the best we can. 247 */ 248 if (lf == linker_kernel_file) { 249 start = SET_BEGIN(modmetadata_set); 250 stop = SET_LIMIT(modmetadata_set); 251 } else { 252 return 0; 253 } 254 } 255 for (mdp = start; mdp < stop; mdp++) { 256 if ((*mdp)->md_type != MDT_MODULE) 257 continue; 258 moddata = (*mdp)->md_data; 259 KLD_DPF(FILE, ("Registering module %s in %s\n", 260 moddata->name, lf->filename)); 261 if (module_lookupbyname(moddata->name) != NULL) { 262 printf("Warning: module %s already exists\n", moddata->name); 263 continue; /* or return a error ? */ 264 } 265 error = module_register(moddata, lf); 266 if (error) 267 printf("Module %s failed to register: %d\n", moddata->name, error); 268 } 269 return 0; 270} 271 272static void 273linker_init_kernel_modules(void) 274{ 275 linker_file_register_modules(linker_kernel_file); 276} 277 278SYSINIT(linker_kernel, SI_SUB_KLD, SI_ORDER_ANY, linker_init_kernel_modules, 0); 279 280int 281linker_load_file(const char* filename, linker_file_t* result) 282{ 283 linker_class_t lc; 284 linker_file_t lf; 285 int foundfile, error = 0; 286 287 /* Refuse to load modules if securelevel raised */ 288 if (securelevel > 0) 289 return EPERM; 290 291 lf = linker_find_file_by_name(filename); 292 if (lf) { 293 KLD_DPF(FILE, ("linker_load_file: file %s is already loaded, incrementing refs\n", filename)); 294 *result = lf; 295 lf->refs++; 296 goto out; 297 } 298 299 lf = NULL; 300 foundfile = 0; 301 TAILQ_FOREACH(lc, &classes, link) { 302 KLD_DPF(FILE, ("linker_load_file: trying to load %s\n", 303 filename)); 304 error = LINKER_LOAD_FILE(lc, filename, &lf); 305 /* 306 * If we got something other than ENOENT, then it exists but we cannot 307 * load it for some other reason. 308 */ 309 if (error != ENOENT) 310 foundfile = 1; 311 if (lf) { 312 linker_file_register_modules(lf); 313 linker_file_register_sysctls(lf); 314 linker_file_sysinit(lf); 315 lf->flags |= LINKER_FILE_LINKED; 316 317 *result = lf; 318 error = 0; 319 goto out; 320 } 321 } 322 /* 323 * Less than ideal, but tells the user whether it failed to load or 324 * the module was not found. 325 */ 326 if (foundfile) 327 error = ENOEXEC; /* Format not recognised (or unloadable) */ 328 else 329 error = ENOENT; /* Nothing found */ 330 331out: 332 return error; 333} 334 335int 336linker_reference_module(const char *modname, linker_file_t *result) 337{ 338 char *pathname; 339 int res; 340 341 /* 342 * There will be a system to look up or guess a file name from 343 * a module name. 344 * For now we just try to load a file with the same name. 345 */ 346 if ((pathname = linker_search_path(modname)) == NULL) 347 return (ENOENT); 348 349 /* 350 * If the module is already loaded or built into the kernel, 351 * linker_load_file() simply bumps it's refcount. 352 */ 353 res = linker_load_file(pathname, result); 354 355 free(pathname, M_LINKER); 356 357 return (res); 358} 359 360linker_file_t 361linker_find_file_by_name(const char* filename) 362{ 363 linker_file_t lf = 0; 364 char *koname; 365 366 koname = malloc(strlen(filename) + 4, M_LINKER, M_WAITOK); 367 if (koname == NULL) 368 goto out; 369 sprintf(koname, "%s.ko", filename); 370 371 lockmgr(&lock, LK_SHARED, 0, curproc); 372 TAILQ_FOREACH(lf, &linker_files, link) { 373 if (!strcmp(lf->filename, koname)) 374 break; 375 if (!strcmp(lf->filename, filename)) 376 break; 377 } 378 lockmgr(&lock, LK_RELEASE, 0, curproc); 379 380out: 381 if (koname) 382 free(koname, M_LINKER); 383 return lf; 384} 385 386linker_file_t 387linker_find_file_by_id(int fileid) 388{ 389 linker_file_t lf = 0; 390 391 lockmgr(&lock, LK_SHARED, 0, curproc); 392 TAILQ_FOREACH(lf, &linker_files, link) 393 if (lf->id == fileid) 394 break; 395 lockmgr(&lock, LK_RELEASE, 0, curproc); 396 397 return lf; 398} 399 400linker_file_t 401linker_make_file(const char* pathname, linker_class_t lc) 402{ 403 linker_file_t lf = 0; 404 const char *filename; 405 406 filename = linker_basename(pathname); 407 408 KLD_DPF(FILE, ("linker_make_file: new file, filename=%s\n", filename)); 409 lockmgr(&lock, LK_EXCLUSIVE, 0, curproc); 410 lf = (linker_file_t) kobj_create((kobj_class_t) lc, M_LINKER, M_WAITOK); 411 if (!lf) 412 goto out; 413 414 lf->refs = 1; 415 lf->userrefs = 0; 416 lf->flags = 0; 417 lf->filename = linker_strdup(filename); 418 lf->id = next_file_id++; 419 lf->ndeps = 0; 420 lf->deps = NULL; 421 STAILQ_INIT(&lf->common); 422 TAILQ_INIT(&lf->modules); 423 424 TAILQ_INSERT_TAIL(&linker_files, lf, link); 425 426out: 427 lockmgr(&lock, LK_RELEASE, 0, curproc); 428 return lf; 429} 430 431int 432linker_file_unload(linker_file_t file) 433{ 434 module_t mod, next; 435 modlist_t ml, nextml; 436 struct common_symbol* cp; 437 int error = 0; 438 int i; 439 440 /* Refuse to unload modules if securelevel raised */ 441 if (securelevel > 0) 442 return EPERM; 443 444 KLD_DPF(FILE, ("linker_file_unload: lf->refs=%d\n", file->refs)); 445 lockmgr(&lock, LK_EXCLUSIVE, 0, curproc); 446 if (file->refs == 1) { 447 KLD_DPF(FILE, ("linker_file_unload: file is unloading, informing modules\n")); 448 /* 449 * Inform any modules associated with this file. 450 */ 451 for (mod = TAILQ_FIRST(&file->modules); mod; mod = next) { 452 next = module_getfnext(mod); 453 454 /* 455 * Give the module a chance to veto the unload. 456 */ 457 if ((error = module_unload(mod)) != 0) { 458 KLD_DPF(FILE, ("linker_file_unload: module %x vetoes unload\n", 459 mod)); 460 lockmgr(&lock, LK_RELEASE, 0, curproc); 461 goto out; 462 } 463 464 module_release(mod); 465 } 466 } 467 468 file->refs--; 469 if (file->refs > 0) { 470 lockmgr(&lock, LK_RELEASE, 0, curproc); 471 goto out; 472 } 473 474 for (ml = TAILQ_FIRST(&found_modules); ml; ml = nextml) { 475 nextml = TAILQ_NEXT(ml, link); 476 if (ml->container == file) { 477 TAILQ_REMOVE(&found_modules, ml, link); 478 } 479 } 480 481 /* Don't try to run SYSUNINITs if we are unloaded due to a link error */ 482 if (file->flags & LINKER_FILE_LINKED) { 483 linker_file_sysuninit(file); 484 linker_file_unregister_sysctls(file); 485 } 486 487 TAILQ_REMOVE(&linker_files, file, link); 488 lockmgr(&lock, LK_RELEASE, 0, curproc); 489 490 if (file->deps) { 491 for (i = 0; i < file->ndeps; i++) 492 linker_file_unload(file->deps[i]); 493 free(file->deps, M_LINKER); 494 file->deps = NULL; 495 } 496 497 for (cp = STAILQ_FIRST(&file->common); cp; 498 cp = STAILQ_FIRST(&file->common)) { 499 STAILQ_REMOVE(&file->common, cp, common_symbol, link); 500 free(cp, M_LINKER); 501 } 502 503 LINKER_UNLOAD(file); 504 if (file->filename) { 505 free(file->filename, M_LINKER); 506 file->filename = NULL; 507 } 508 kobj_delete((kobj_t) file, M_LINKER); 509 510out: 511 return error; 512} 513 514int 515linker_file_add_dependancy(linker_file_t file, linker_file_t dep) 516{ 517 linker_file_t* newdeps; 518 519 newdeps = malloc((file->ndeps + 1) * sizeof(linker_file_t*), 520 M_LINKER, M_WAITOK | M_ZERO); 521 if (newdeps == NULL) 522 return ENOMEM; 523 524 if (file->deps) { 525 bcopy(file->deps, newdeps, file->ndeps * sizeof(linker_file_t*)); 526 free(file->deps, M_LINKER); 527 } 528 file->deps = newdeps; 529 file->deps[file->ndeps] = dep; 530 file->ndeps++; 531 532 return 0; 533} 534 535/* 536 * Locate a linker set and its contents. 537 * This is a helper function to avoid linker_if.h exposure elsewhere. 538 * Note: firstp and lastp are really void *** 539 */ 540int 541linker_file_lookup_set(linker_file_t file, const char *name, 542 void *firstp, void *lastp, int *countp) 543{ 544 545 return LINKER_LOOKUP_SET(file, name, firstp, lastp, countp); 546} 547 548caddr_t 549linker_file_lookup_symbol(linker_file_t file, const char* name, int deps) 550{ 551 c_linker_sym_t sym; 552 linker_symval_t symval; 553 caddr_t address; 554 size_t common_size = 0; 555 int i; 556 557 KLD_DPF(SYM, ("linker_file_lookup_symbol: file=%x, name=%s, deps=%d\n", 558 file, name, deps)); 559 560 if (LINKER_LOOKUP_SYMBOL(file, name, &sym) == 0) { 561 LINKER_SYMBOL_VALUES(file, sym, &symval); 562 if (symval.value == 0) 563 /* 564 * For commons, first look them up in the dependancies and 565 * only allocate space if not found there. 566 */ 567 common_size = symval.size; 568 else { 569 KLD_DPF(SYM, ("linker_file_lookup_symbol: symbol.value=%x\n", symval.value)); 570 return symval.value; 571 } 572 } 573 574 if (deps) { 575 for (i = 0; i < file->ndeps; i++) { 576 address = linker_file_lookup_symbol(file->deps[i], name, 0); 577 if (address) { 578 KLD_DPF(SYM, ("linker_file_lookup_symbol: deps value=%x\n", address)); 579 return address; 580 } 581 } 582 } 583 584 if (common_size > 0) { 585 /* 586 * This is a common symbol which was not found in the 587 * dependancies. We maintain a simple common symbol table in 588 * the file object. 589 */ 590 struct common_symbol* cp; 591 592 STAILQ_FOREACH(cp, &file->common, link) 593 if (!strcmp(cp->name, name)) { 594 KLD_DPF(SYM, ("linker_file_lookup_symbol: old common value=%x\n", cp->address)); 595 return cp->address; 596 } 597 598 /* 599 * Round the symbol size up to align. 600 */ 601 common_size = (common_size + sizeof(int) - 1) & -sizeof(int); 602 cp = malloc(sizeof(struct common_symbol) 603 + common_size 604 + strlen(name) + 1, 605 M_LINKER, M_WAITOK | M_ZERO); 606 if (!cp) { 607 KLD_DPF(SYM, ("linker_file_lookup_symbol: nomem\n")); 608 return 0; 609 } 610 611 cp->address = (caddr_t) (cp + 1); 612 cp->name = cp->address + common_size; 613 strcpy(cp->name, name); 614 bzero(cp->address, common_size); 615 STAILQ_INSERT_TAIL(&file->common, cp, link); 616 617 KLD_DPF(SYM, ("linker_file_lookup_symbol: new common value=%x\n", cp->address)); 618 return cp->address; 619 } 620 621 KLD_DPF(SYM, ("linker_file_lookup_symbol: fail\n")); 622 return 0; 623} 624 625#ifdef DDB 626/* 627 * DDB Helpers. DDB has to look across multiple files with their own 628 * symbol tables and string tables. 629 * 630 * Note that we do not obey list locking protocols here. We really don't 631 * need DDB to hang because somebody's got the lock held. We'll take the 632 * chance that the files list is inconsistant instead. 633 */ 634 635int 636linker_ddb_lookup(const char *symstr, c_linker_sym_t *sym) 637{ 638 linker_file_t lf; 639 640 TAILQ_FOREACH(lf, &linker_files, link) { 641 if (LINKER_LOOKUP_SYMBOL(lf, symstr, sym) == 0) 642 return 0; 643 } 644 return ENOENT; 645} 646 647int 648linker_ddb_search_symbol(caddr_t value, c_linker_sym_t *sym, long *diffp) 649{ 650 linker_file_t lf; 651 u_long off = (uintptr_t)value; 652 u_long diff, bestdiff; 653 c_linker_sym_t best; 654 c_linker_sym_t es; 655 656 best = 0; 657 bestdiff = off; 658 TAILQ_FOREACH(lf, &linker_files, link) { 659 if (LINKER_SEARCH_SYMBOL(lf, value, &es, &diff) != 0) 660 continue; 661 if (es != 0 && diff < bestdiff) { 662 best = es; 663 bestdiff = diff; 664 } 665 if (bestdiff == 0) 666 break; 667 } 668 if (best) { 669 *sym = best; 670 *diffp = bestdiff; 671 return 0; 672 } else { 673 *sym = 0; 674 *diffp = off; 675 return ENOENT; 676 } 677} 678 679int 680linker_ddb_symbol_values(c_linker_sym_t sym, linker_symval_t *symval) 681{ 682 linker_file_t lf; 683 684 TAILQ_FOREACH(lf, &linker_files, link) { 685 if (LINKER_SYMBOL_VALUES(lf, sym, symval) == 0) 686 return 0; 687 } 688 return ENOENT; 689} 690 691#endif 692 693/* 694 * Syscalls. 695 */ 696/* 697 * MPSAFE 698 */ 699int 700kldload(struct proc* p, struct kldload_args* uap) 701{ 702 char *pathname = NULL; 703 char *realpath = NULL; 704 const char *filename; 705 linker_file_t lf; 706 int error = 0; 707 708 p->p_retval[0] = -1; 709 710 if (securelevel > 0) /* redundant, but that's OK */ 711 return EPERM; 712 713 mtx_lock(&Giant); 714 715 if ((error = suser(p)) != 0) 716 goto out; 717 718 pathname = malloc(MAXPATHLEN, M_TEMP, M_WAITOK); 719 if ((error = copyinstr(SCARG(uap, file), pathname, MAXPATHLEN, NULL)) != 0) 720 goto out; 721 722 realpath = linker_search_path(pathname); 723 if (realpath == NULL) { 724 error = ENOENT; 725 goto out; 726 } 727 /* Can't load more than one file with the same name */ 728 filename = linker_basename(realpath); 729 if (linker_find_file_by_name(filename)) { 730 error = EEXIST; 731 goto out; 732 } 733 734 if ((error = linker_load_file(realpath, &lf)) != 0) 735 goto out; 736 737 lf->userrefs++; 738 p->p_retval[0] = lf->id; 739 740out: 741 if (pathname) 742 free(pathname, M_TEMP); 743 if (realpath) 744 free(realpath, M_LINKER); 745 mtx_unlock(&Giant); 746 return (error); 747} 748 749/* 750 * MPSAFE 751 */ 752int 753kldunload(struct proc* p, struct kldunload_args* uap) 754{ 755 linker_file_t lf; 756 int error = 0; 757 758 if (securelevel > 0) /* redundant, but that's OK */ 759 return EPERM; 760 761 mtx_lock(&Giant); 762 763 if ((error = suser(p)) != 0) 764 goto out; 765 766 lf = linker_find_file_by_id(SCARG(uap, fileid)); 767 if (lf) { 768 KLD_DPF(FILE, ("kldunload: lf->userrefs=%d\n", lf->userrefs)); 769 if (lf->userrefs == 0) { 770 printf("kldunload: attempt to unload file that was loaded by the kernel\n"); 771 error = EBUSY; 772 goto out; 773 } 774 lf->userrefs--; 775 error = linker_file_unload(lf); 776 if (error) 777 lf->userrefs++; 778 } else { 779 error = ENOENT; 780 } 781out: 782 mtx_unlock(&Giant); 783 return (error); 784} 785 786/* 787 * MPSAFE 788 */ 789int 790kldfind(struct proc* p, struct kldfind_args* uap) 791{ 792 char* pathname; 793 const char *filename; 794 linker_file_t lf; 795 int error = 0; 796 797 mtx_lock(&Giant); 798 799 p->p_retval[0] = -1; 800 801 pathname = malloc(MAXPATHLEN, M_TEMP, M_WAITOK); 802 if ((error = copyinstr(SCARG(uap, file), pathname, MAXPATHLEN, NULL)) != 0) 803 goto out; 804 805 filename = linker_basename(pathname); 806 807 lf = linker_find_file_by_name(filename); 808 if (lf) 809 p->p_retval[0] = lf->id; 810 else 811 error = ENOENT; 812 813out: 814 if (pathname) 815 free(pathname, M_TEMP); 816 mtx_unlock(&Giant); 817 return (error); 818} 819 820/* 821 * MPSAFE 822 */ 823int 824kldnext(struct proc* p, struct kldnext_args* uap) 825{ 826 linker_file_t lf; 827 int error = 0; 828 829 mtx_lock(&Giant); 830 831 if (SCARG(uap, fileid) == 0) { 832 if (TAILQ_FIRST(&linker_files)) 833 p->p_retval[0] = TAILQ_FIRST(&linker_files)->id; 834 else 835 p->p_retval[0] = 0; 836 goto out; 837 } 838 839 lf = linker_find_file_by_id(SCARG(uap, fileid)); 840 if (lf) { 841 if (TAILQ_NEXT(lf, link)) 842 p->p_retval[0] = TAILQ_NEXT(lf, link)->id; 843 else 844 p->p_retval[0] = 0; 845 } else { 846 error = ENOENT; 847 } 848out: 849 mtx_unlock(&Giant); 850 return (error); 851} 852 853/* 854 * MPSAFE 855 */ 856int 857kldstat(struct proc* p, struct kldstat_args* uap) 858{ 859 linker_file_t lf; 860 int error = 0; 861 int version; 862 struct kld_file_stat* stat; 863 int namelen; 864 865 mtx_lock(&Giant); 866 867 lf = linker_find_file_by_id(SCARG(uap, fileid)); 868 if (!lf) { 869 error = ENOENT; 870 goto out; 871 } 872 873 stat = SCARG(uap, stat); 874 875 /* 876 * Check the version of the user's structure. 877 */ 878 if ((error = copyin(&stat->version, &version, sizeof(version))) != 0) 879 goto out; 880 if (version != sizeof(struct kld_file_stat)) { 881 error = EINVAL; 882 goto out; 883 } 884 885 namelen = strlen(lf->filename) + 1; 886 if (namelen > MAXPATHLEN) 887 namelen = MAXPATHLEN; 888 if ((error = copyout(lf->filename, &stat->name[0], namelen)) != 0) 889 goto out; 890 if ((error = copyout(&lf->refs, &stat->refs, sizeof(int))) != 0) 891 goto out; 892 if ((error = copyout(&lf->id, &stat->id, sizeof(int))) != 0) 893 goto out; 894 if ((error = copyout(&lf->address, &stat->address, sizeof(caddr_t))) != 0) 895 goto out; 896 if ((error = copyout(&lf->size, &stat->size, sizeof(size_t))) != 0) 897 goto out; 898 899 p->p_retval[0] = 0; 900 901out: 902 mtx_unlock(&Giant); 903 return (error); 904} 905 906/* 907 * MPSAFE 908 */ 909int 910kldfirstmod(struct proc* p, struct kldfirstmod_args* uap) 911{ 912 linker_file_t lf; 913 int error = 0; 914 915 mtx_lock(&Giant); 916 lf = linker_find_file_by_id(SCARG(uap, fileid)); 917 if (lf) { 918 if (TAILQ_FIRST(&lf->modules)) 919 p->p_retval[0] = module_getid(TAILQ_FIRST(&lf->modules)); 920 else 921 p->p_retval[0] = 0; 922 } else { 923 error = ENOENT; 924 } 925 mtx_unlock(&Giant); 926 return (error); 927} 928 929/* 930 * MPSAFE 931 */ 932int 933kldsym(struct proc *p, struct kldsym_args *uap) 934{ 935 char *symstr = NULL; 936 c_linker_sym_t sym; 937 linker_symval_t symval; 938 linker_file_t lf; 939 struct kld_sym_lookup lookup; 940 int error = 0; 941 942 mtx_lock(&Giant); 943 944 if ((error = copyin(SCARG(uap, data), &lookup, sizeof(lookup))) != 0) 945 goto out; 946 if (lookup.version != sizeof(lookup) || SCARG(uap, cmd) != KLDSYM_LOOKUP) { 947 error = EINVAL; 948 goto out; 949 } 950 951 symstr = malloc(MAXPATHLEN, M_TEMP, M_WAITOK); 952 if ((error = copyinstr(lookup.symname, symstr, MAXPATHLEN, NULL)) != 0) 953 goto out; 954 955 if (SCARG(uap, fileid) != 0) { 956 lf = linker_find_file_by_id(SCARG(uap, fileid)); 957 if (lf == NULL) { 958 error = ENOENT; 959 goto out; 960 } 961 if (LINKER_LOOKUP_SYMBOL(lf, symstr, &sym) == 0 && 962 LINKER_SYMBOL_VALUES(lf, sym, &symval) == 0) { 963 lookup.symvalue = (uintptr_t)symval.value; 964 lookup.symsize = symval.size; 965 error = copyout(&lookup, SCARG(uap, data), sizeof(lookup)); 966 } else 967 error = ENOENT; 968 } else { 969 TAILQ_FOREACH(lf, &linker_files, link) { 970 if (LINKER_LOOKUP_SYMBOL(lf, symstr, &sym) == 0 && 971 LINKER_SYMBOL_VALUES(lf, sym, &symval) == 0) { 972 lookup.symvalue = (uintptr_t)symval.value; 973 lookup.symsize = symval.size; 974 error = copyout(&lookup, SCARG(uap, data), sizeof(lookup)); 975 break; 976 } 977 } 978 if (!lf) 979 error = ENOENT; 980 } 981out: 982 if (symstr) 983 free(symstr, M_TEMP); 984 mtx_unlock(&Giant); 985 return (error); 986} 987 988/* 989 * Preloaded module support 990 */ 991 992static modlist_t 993modlist_lookup(const char *name, int ver) 994{ 995 modlist_t mod; 996 997 TAILQ_FOREACH(mod, &found_modules, link) { 998 if (strcmp(mod->name, name) == 0 && (ver == 0 || mod->version == ver)) 999 return mod; 1000 } 1001 return NULL; 1002} 1003 1004static modlist_t 1005modlist_newmodule(const char *modname, int version, linker_file_t container) 1006{ 1007 modlist_t mod; 1008 1009 mod = malloc(sizeof(struct modlist), M_LINKER, M_NOWAIT); 1010 if (mod == NULL) 1011 panic("no memory for module list"); 1012 bzero(mod, sizeof(*mod)); 1013 mod->container = container; 1014 mod->name = modname; 1015 mod->version = version; 1016 TAILQ_INSERT_TAIL(&found_modules, mod, link); 1017 return mod; 1018} 1019 1020/* 1021 * This routine is cheap and nasty but will work for data pointers. 1022 */ 1023static void * 1024linker_reloc_ptr(linker_file_t lf, const void *offset) 1025{ 1026 return lf->address + (uintptr_t)offset; 1027} 1028 1029/* 1030 * Dereference MDT_VERSION metadata into module name and version 1031 */ 1032static void 1033linker_mdt_version(linker_file_t lf, struct mod_metadata *mp, 1034 const char **modname, int *version) 1035{ 1036 struct mod_version *mvp; 1037 1038 if (modname) 1039 *modname = linker_reloc_ptr(lf, mp->md_cval); 1040 if (version) { 1041 mvp = linker_reloc_ptr(lf, mp->md_data); 1042 *version = mvp->mv_version; 1043 } 1044} 1045 1046/* 1047 * Dereference MDT_DEPEND metadata into module name and mod_depend structure 1048 */ 1049static void 1050linker_mdt_depend(linker_file_t lf, struct mod_metadata *mp, 1051 const char **modname, struct mod_depend **verinfo) 1052{ 1053 1054 if (modname) 1055 *modname = linker_reloc_ptr(lf, mp->md_cval); 1056 if (verinfo) 1057 *verinfo = linker_reloc_ptr(lf, mp->md_data); 1058} 1059 1060static void 1061linker_addmodules(linker_file_t lf, struct mod_metadata **start, 1062 struct mod_metadata **stop, int preload) 1063{ 1064 struct mod_metadata *mp, **mdp; 1065 const char *modname; 1066 int ver; 1067 1068 for (mdp = start; mdp < stop; mdp++) { 1069 if (preload) 1070 mp = *mdp; 1071 else 1072 mp = linker_reloc_ptr(lf, *mdp); 1073 if (mp->md_type != MDT_VERSION) 1074 continue; 1075 if (preload) { 1076 modname = mp->md_cval; 1077 ver = ((struct mod_version*)mp->md_data)->mv_version; 1078 } else 1079 linker_mdt_version(lf, mp, &modname, &ver); 1080 if (modlist_lookup(modname, ver) != NULL) { 1081 printf("module %s already present!\n", modname); 1082 /* XXX what can we do? this is a build error. :-( */ 1083 continue; 1084 } 1085 modlist_newmodule(modname, ver, lf); 1086 } 1087} 1088 1089static void 1090linker_preload(void* arg) 1091{ 1092 caddr_t modptr; 1093 const char *modname, *nmodname; 1094 char *modtype; 1095 linker_file_t lf; 1096 linker_class_t lc; 1097 int error; 1098 linker_file_list_t loaded_files; 1099 linker_file_list_t depended_files; 1100 struct mod_metadata *mp, *nmp; 1101 struct mod_metadata **start, **stop, **mdp, **nmdp; 1102 struct mod_depend *verinfo; 1103 int nver; 1104 int resolves; 1105 modlist_t mod; 1106 struct sysinit **si_start, **si_stop; 1107 1108 TAILQ_INIT(&loaded_files); 1109 TAILQ_INIT(&depended_files); 1110 TAILQ_INIT(&found_modules); 1111 error = 0; 1112 1113 modptr = NULL; 1114 while ((modptr = preload_search_next_name(modptr)) != NULL) { 1115 modname = (char *)preload_search_info(modptr, MODINFO_NAME); 1116 modtype = (char *)preload_search_info(modptr, MODINFO_TYPE); 1117 if (modname == NULL) { 1118 printf("Preloaded module at %p does not have a name!\n", modptr); 1119 continue; 1120 } 1121 if (modtype == NULL) { 1122 printf("Preloaded module at %p does not have a type!\n", modptr); 1123 continue; 1124 } 1125 printf("Preloaded %s \"%s\" at %p.\n", modtype, modname, modptr); 1126 lf = NULL; 1127 TAILQ_FOREACH(lc, &classes, link) { 1128 error = LINKER_LINK_PRELOAD(lc, modname, &lf); 1129 if (error) { 1130 lf = NULL; 1131 break; 1132 } 1133 } 1134 if (lf) 1135 TAILQ_INSERT_TAIL(&loaded_files, lf, loaded); 1136 } 1137 1138 /* 1139 * First get a list of stuff in the kernel. 1140 */ 1141 if (linker_file_lookup_set(linker_kernel_file, MDT_SETNAME, &start, &stop, 1142 NULL) == 0) 1143 linker_addmodules(linker_kernel_file, start, stop, 1); 1144 1145 /* 1146 * this is a once-off kinky bubble sort 1147 * resolve relocation dependency requirements 1148 */ 1149restart: 1150 TAILQ_FOREACH(lf, &loaded_files, loaded) { 1151 error = linker_file_lookup_set(lf, MDT_SETNAME, &start, &stop, NULL); 1152 /* 1153 * First, look to see if we would successfully link with this stuff. 1154 */ 1155 resolves = 1; /* unless we know otherwise */ 1156 if (!error) { 1157 for (mdp = start; mdp < stop; mdp++) { 1158 mp = linker_reloc_ptr(lf, *mdp); 1159 if (mp->md_type != MDT_DEPEND) 1160 continue; 1161 linker_mdt_depend(lf, mp, &modname, &verinfo); 1162 for (nmdp = start; nmdp < stop; nmdp++) { 1163 nmp = linker_reloc_ptr(lf, *nmdp); 1164 if (nmp->md_type != MDT_VERSION) 1165 continue; 1166 linker_mdt_version(lf, nmp, &nmodname, NULL); 1167 nmodname = linker_reloc_ptr(lf, nmp->md_cval); 1168 if (strcmp(modname, nmodname) == 0) 1169 break; 1170 } 1171 if (nmdp < stop) /* it's a self reference */ 1172 continue; 1173 if (modlist_lookup(modname, 0) == NULL) { 1174 /* ok, the module isn't here yet, we are not finished */ 1175 resolves = 0; 1176 } 1177 } 1178 } 1179 /* 1180 * OK, if we found our modules, we can link. So, "provide" the 1181 * modules inside and add it to the end of the link order list. 1182 */ 1183 if (resolves) { 1184 if (!error) { 1185 for (mdp = start; mdp < stop; mdp++) { 1186 mp = linker_reloc_ptr(lf, *mdp); 1187 if (mp->md_type != MDT_VERSION) 1188 continue; 1189 linker_mdt_version(lf, mp, &modname, &nver); 1190 if (modlist_lookup(modname, nver) != NULL) { 1191 printf("module %s already present!\n", modname); 1192 linker_file_unload(lf); 1193 TAILQ_REMOVE(&loaded_files, lf, loaded); 1194 goto restart; /* we changed the tailq next ptr */ 1195 } 1196 modlist_newmodule(modname, nver, lf); 1197 } 1198 } 1199 TAILQ_REMOVE(&loaded_files, lf, loaded); 1200 TAILQ_INSERT_TAIL(&depended_files, lf, loaded); 1201 /* 1202 * Since we provided modules, we need to restart the sort so 1203 * that the previous files that depend on us have a chance. 1204 * Also, we've busted the tailq next pointer with the REMOVE. 1205 */ 1206 goto restart; 1207 } 1208 } 1209 1210 /* 1211 * At this point, we check to see what could not be resolved.. 1212 */ 1213 TAILQ_FOREACH(lf, &loaded_files, loaded) { 1214 printf("KLD file %s is missing dependencies\n", lf->filename); 1215 linker_file_unload(lf); 1216 TAILQ_REMOVE(&loaded_files, lf, loaded); 1217 } 1218 1219 /* 1220 * We made it. Finish off the linking in the order we determined. 1221 */ 1222 TAILQ_FOREACH(lf, &depended_files, loaded) { 1223 if (linker_kernel_file) { 1224 linker_kernel_file->refs++; 1225 error = linker_file_add_dependancy(lf, linker_kernel_file); 1226 if (error) 1227 panic("cannot add dependency"); 1228 } 1229 lf->userrefs++; /* so we can (try to) kldunload it */ 1230 error = linker_file_lookup_set(lf, MDT_SETNAME, &start, &stop, NULL); 1231 if (!error) { 1232 for (mdp = start; mdp < stop; mdp++) { 1233 mp = linker_reloc_ptr(lf, *mdp); 1234 if (mp->md_type != MDT_DEPEND) 1235 continue; 1236 linker_mdt_depend(lf, mp, &modname, &verinfo); 1237 mod = modlist_lookup(modname, 0); 1238 mod->container->refs++; 1239 error = linker_file_add_dependancy(lf, mod->container); 1240 if (error) 1241 panic("cannot add dependency"); 1242 } 1243 } 1244 1245 /* 1246 * Now do relocation etc using the symbol search paths established by 1247 * the dependencies 1248 */ 1249 error = LINKER_LINK_PRELOAD_FINISH(lf); 1250 if (error) { 1251 printf("KLD file %s - could not finalize loading\n", lf->filename); 1252 linker_file_unload(lf); 1253 continue; 1254 } 1255 1256 linker_file_register_modules(lf); 1257 if (linker_file_lookup_set(lf, "sysinit_set", &si_start, &si_stop, NULL) == 0) 1258 sysinit_add(si_start, si_stop); 1259 linker_file_register_sysctls(lf); 1260 lf->flags |= LINKER_FILE_LINKED; 1261 } 1262 /* woohoo! we made it! */ 1263} 1264 1265SYSINIT(preload, SI_SUB_KLD, SI_ORDER_MIDDLE, linker_preload, 0); 1266 1267/* 1268 * Search for a not-loaded module by name. 1269 * 1270 * Modules may be found in the following locations: 1271 * 1272 * - preloaded (result is just the module name) 1273 * - on disk (result is full path to module) 1274 * 1275 * If the module name is qualified in any way (contains path, etc.) 1276 * the we simply return a copy of it. 1277 * 1278 * The search path can be manipulated via sysctl. Note that we use the ';' 1279 * character as a separator to be consistent with the bootloader. 1280 */ 1281 1282static char linker_path[MAXPATHLEN] = "/boot/kernel;/boot/modules/;/modules/"; 1283 1284SYSCTL_STRING(_kern, OID_AUTO, module_path, CTLFLAG_RW, linker_path, 1285 sizeof(linker_path), "module load search path"); 1286 1287TUNABLE_STR("module_path", linker_path, sizeof(linker_path)); 1288 1289static char *linker_ext_list[] = { 1290 ".ko", 1291 "", 1292 NULL 1293}; 1294 1295static char * 1296linker_search_path(const char *name) 1297{ 1298 struct nameidata nd; 1299 struct proc *p = curproc; /* XXX */ 1300 char *cp, *ep, *result, **cpp; 1301 int error, extlen, len, flags; 1302 enum vtype type; 1303 1304 /* qualified at all? */ 1305 if (index(name, '/')) 1306 return(linker_strdup(name)); 1307 1308 extlen = 0; 1309 for (cpp = linker_ext_list; *cpp; cpp++) { 1310 len = strlen(*cpp); 1311 if (len > extlen) 1312 extlen = len; 1313 } 1314 extlen++; /* trailing '\0' */ 1315 1316 /* traverse the linker path */ 1317 cp = linker_path; 1318 len = strlen(name); 1319 for (;;) { 1320 1321 /* find the end of this component */ 1322 for (ep = cp; (*ep != 0) && (*ep != ';'); ep++) 1323 ; 1324 result = malloc((len + (ep - cp) + extlen + 1), M_LINKER, M_WAITOK); 1325 if (result == NULL) /* actually ENOMEM */ 1326 return(NULL); 1327 for (cpp = linker_ext_list; *cpp; cpp++) { 1328 strncpy(result, cp, ep - cp); 1329 strcpy(result + (ep - cp), "/"); 1330 strcat(result, name); 1331 strcat(result, *cpp); 1332 /* 1333 * Attempt to open the file, and return the path if we succeed 1334 * and it's a regular file. 1335 */ 1336 NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, result, p); 1337 flags = FREAD; 1338 error = vn_open(&nd, &flags, 0); 1339 if (error == 0) { 1340 NDFREE(&nd, NDF_ONLY_PNBUF); 1341 type = nd.ni_vp->v_type; 1342 VOP_UNLOCK(nd.ni_vp, 0, p); 1343 vn_close(nd.ni_vp, FREAD, p->p_ucred, p); 1344 if (type == VREG) 1345 return(result); 1346 } 1347 } 1348 free(result, M_LINKER); 1349 1350 if (*ep == 0) 1351 break; 1352 cp = ep + 1; 1353 } 1354 return(NULL); 1355} 1356 1357static const char * 1358linker_basename(const char* path) 1359{ 1360 const char *filename; 1361 1362 filename = rindex(path, '/'); 1363 if (filename == NULL) 1364 return path; 1365 if (filename[1]) 1366 filename++; 1367 return filename; 1368} 1369 1370/* 1371 * Find a file which contains given module and load it, 1372 * if "parent" is not NULL, register a reference to it. 1373 */ 1374static int 1375linker_load_module(const char *modname, struct linker_file *parent) 1376{ 1377 linker_file_t lfdep; 1378 const char *filename; 1379 char *pathname; 1380 int error; 1381 1382 /* 1383 * There will be a system to look up or guess a file name from 1384 * a module name. 1385 * For now we just try to load a file with the same name. 1386 */ 1387 pathname = linker_search_path(modname); 1388 if (pathname == NULL) 1389 return ENOENT; 1390 1391 /* Can't load more than one file with the same basename */ 1392 filename = linker_basename(pathname); 1393 if (linker_find_file_by_name(filename)) { 1394 error = EEXIST; 1395 goto out; 1396 } 1397 1398 do { 1399 error = linker_load_file(pathname, &lfdep); 1400 if (error) 1401 break; 1402 if (parent) { 1403 error = linker_file_add_dependancy(parent, lfdep); 1404 if (error) 1405 break; 1406 } 1407 } while(0); 1408out: 1409 if (pathname) 1410 free(pathname, M_LINKER); 1411 return error; 1412} 1413 1414/* 1415 * This routine is responsible for finding dependencies of userland 1416 * initiated kldload(2)'s of files. 1417 */ 1418int 1419linker_load_dependancies(linker_file_t lf) 1420{ 1421 linker_file_t lfdep; 1422 struct mod_metadata **start, **stop, **mdp, **nmdp; 1423 struct mod_metadata *mp, *nmp; 1424 modlist_t mod; 1425 const char *modname, *nmodname; 1426 int ver, error = 0, count; 1427 1428 /* 1429 * All files are dependant on /kernel. 1430 */ 1431 if (linker_kernel_file) { 1432 linker_kernel_file->refs++; 1433 error = linker_file_add_dependancy(lf, linker_kernel_file); 1434 if (error) 1435 return error; 1436 } 1437 1438 if (linker_file_lookup_set(lf, MDT_SETNAME, &start, &stop, &count) != 0) 1439 return 0; 1440 for (mdp = start; mdp < stop; mdp++) { 1441 mp = linker_reloc_ptr(lf, *mdp); 1442 if (mp->md_type != MDT_VERSION) 1443 continue; 1444 linker_mdt_version(lf, mp, &modname, &ver); 1445 mod = modlist_lookup(modname, ver); 1446 if (mod != NULL) { 1447 printf("interface %s.%d already present in the KLD '%s'!\n", 1448 modname, ver, mod->container->filename); 1449 return EEXIST; 1450 } 1451 } 1452 1453 for (mdp = start; mdp < stop; mdp++) { 1454 mp = linker_reloc_ptr(lf, *mdp); 1455 if (mp->md_type != MDT_DEPEND) 1456 continue; 1457 modname = linker_reloc_ptr(lf, mp->md_cval); 1458 nmodname = NULL; 1459 for (nmdp = start; nmdp < stop; nmdp++) { 1460 nmp = linker_reloc_ptr(lf, *nmdp); 1461 if (nmp->md_type != MDT_VERSION) 1462 continue; 1463 nmodname = linker_reloc_ptr(lf, nmp->md_cval); 1464 if (strcmp(modname, nmodname) == 0) 1465 break; 1466 } 1467 if (nmdp < stop) /* early exit, it's a self reference */ 1468 continue; 1469 mod = modlist_lookup(modname, 0); 1470 if (mod) { /* woohoo, it's loaded already */ 1471 lfdep = mod->container; 1472 lfdep->refs++; 1473 error = linker_file_add_dependancy(lf, lfdep); 1474 if (error) 1475 break; 1476 continue; 1477 } 1478 error = linker_load_module(modname, lf); 1479 if (error) { 1480 printf("KLD %s: depends on %s - not available\n", 1481 lf->filename, modname); 1482 break; 1483 } 1484 } 1485 1486 if (error) 1487 return error; 1488 linker_addmodules(lf, start, stop, 0); 1489 return error; 1490} 1491