1 /*- 2 * Copyright (c) 1997 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: src/sys/kern/kern_linker.c,v 1.41.2.3 2001/11/21 17:50:35 luigi Exp $ 27 * $DragonFly: src/sys/kern/kern_linker.c,v 1.44 2008/09/01 19:39:44 dillon Exp $ 28 */ 29 30 #include "opt_ddb.h" 31 32 #include <sys/param.h> 33 #include <sys/kernel.h> 34 #include <sys/systm.h> 35 #include <sys/malloc.h> 36 #include <sys/sysproto.h> 37 #include <sys/sysent.h> 38 #include <sys/proc.h> 39 #include <sys/priv.h> 40 #include <sys/lock.h> 41 #include <sys/module.h> 42 #include <sys/queue.h> 43 #include <sys/linker.h> 44 #include <sys/fcntl.h> 45 #include <sys/libkern.h> 46 #include <sys/nlookup.h> 47 #include <sys/vnode.h> 48 #include <sys/sysctl.h> 49 50 #include <vm/vm_zone.h> 51 52 #ifdef _KERNEL_VIRTUAL 53 #include <dlfcn.h> 54 #endif 55 56 #ifdef KLD_DEBUG 57 int kld_debug = 0; 58 #endif 59 60 /* Metadata from the static kernel */ 61 SET_DECLARE(modmetadata_set, struct mod_metadata); 62 MALLOC_DEFINE(M_LINKER, "kld", "kernel linker"); 63 64 linker_file_t linker_current_file; 65 linker_file_t linker_kernel_file; 66 67 static struct lock lock; /* lock for the file list */ 68 static linker_class_list_t classes; 69 static linker_file_list_t linker_files; 70 static int next_file_id = 1; 71 72 static void 73 linker_init(void* arg) 74 { 75 lockinit(&lock, "klink", 0, 0); 76 TAILQ_INIT(&classes); 77 TAILQ_INIT(&linker_files); 78 } 79 80 SYSINIT(linker, SI_BOOT2_KLD, SI_ORDER_FIRST, linker_init, 0); 81 82 int 83 linker_add_class(const char* desc, void* priv, 84 struct linker_class_ops* ops) 85 { 86 linker_class_t lc; 87 88 lc = kmalloc(sizeof(struct linker_class), M_LINKER, M_NOWAIT | M_ZERO); 89 if (!lc) 90 return ENOMEM; 91 92 lc->desc = desc; 93 lc->priv = priv; 94 lc->ops = ops; 95 TAILQ_INSERT_HEAD(&classes, lc, link); 96 97 return 0; 98 } 99 100 static int 101 linker_file_sysinit(linker_file_t lf) 102 { 103 struct sysinit** start, ** stop; 104 struct sysinit** sipp; 105 struct sysinit** xipp; 106 struct sysinit* save; 107 const moduledata_t *moddata; 108 int error; 109 110 KLD_DPF(FILE, ("linker_file_sysinit: calling SYSINITs for %s\n", 111 lf->filename)); 112 113 if (linker_file_lookup_set(lf, "sysinit_set", &start, &stop, NULL) != 0) 114 return 0; /* XXX is this correct ? No sysinit ? */ 115 116 /* HACK ALERT! */ 117 for (sipp = start; sipp < stop; sipp++) { 118 if ((*sipp)->func == module_register_init) { 119 moddata = (*sipp)->udata; 120 error = module_register(moddata, lf); 121 if (error) { 122 kprintf("linker_file_sysinit \"%s\" failed to register! %d\n", 123 lf->filename, error); 124 return error; 125 } 126 } 127 } 128 129 /* 130 * Perform a bubble sort of the system initialization objects by 131 * their subsystem (primary key) and order (secondary key). 132 * 133 * Since some things care about execution order, this is the 134 * operation which ensures continued function. 135 */ 136 for (sipp = start; sipp < stop; sipp++) { 137 for (xipp = sipp + 1; xipp < stop; xipp++) { 138 if ((*sipp)->subsystem < (*xipp)->subsystem || 139 ((*sipp)->subsystem == (*xipp)->subsystem && 140 (*sipp)->order <= (*xipp)->order)) 141 continue; /* skip*/ 142 save = *sipp; 143 *sipp = *xipp; 144 *xipp = save; 145 } 146 } 147 148 149 /* 150 * Traverse the (now) ordered list of system initialization tasks. 151 * Perform each task, and continue on to the next task. 152 */ 153 for (sipp = start; sipp < stop; sipp++) { 154 if ((*sipp)->subsystem == SI_SPECIAL_DUMMY) 155 continue; /* skip dummy task(s)*/ 156 157 /* Call function */ 158 (*((*sipp)->func))((*sipp)->udata); 159 } 160 return 0; /* no errors */ 161 } 162 163 static void 164 linker_file_sysuninit(linker_file_t lf) 165 { 166 struct sysinit** start, ** stop; 167 struct sysinit** sipp; 168 struct sysinit** xipp; 169 struct sysinit* save; 170 171 KLD_DPF(FILE, ("linker_file_sysuninit: calling SYSUNINITs for %s\n", 172 lf->filename)); 173 174 if (linker_file_lookup_set(lf, "sysuninit_set", &start, &stop, NULL) != 0) 175 return; 176 177 /* 178 * Perform a reverse bubble sort of the system initialization objects 179 * by their subsystem (primary key) and order (secondary key). 180 * 181 * Since some things care about execution order, this is the 182 * operation which ensures continued function. 183 */ 184 for (sipp = start; sipp < stop; sipp++) { 185 for (xipp = sipp + 1; xipp < stop; xipp++) { 186 if ((*sipp)->subsystem > (*xipp)->subsystem || 187 ((*sipp)->subsystem == (*xipp)->subsystem && 188 (*sipp)->order >= (*xipp)->order)) 189 continue; /* skip*/ 190 save = *sipp; 191 *sipp = *xipp; 192 *xipp = save; 193 } 194 } 195 196 197 /* 198 * Traverse the (now) ordered list of system initialization tasks. 199 * Perform each task, and continue on to the next task. 200 */ 201 for (sipp = start; sipp < stop; sipp++) { 202 if ((*sipp)->subsystem == SI_SPECIAL_DUMMY) 203 continue; /* skip dummy task(s)*/ 204 205 /* Call function */ 206 (*((*sipp)->func))((*sipp)->udata); 207 } 208 } 209 210 static void 211 linker_file_register_sysctls(linker_file_t lf) 212 { 213 struct sysctl_oid **start, **stop, **oidp; 214 215 KLD_DPF(FILE, ("linker_file_register_sysctls: registering SYSCTLs for %s\n", 216 lf->filename)); 217 218 if (linker_file_lookup_set(lf, "sysctl_set", &start, &stop, NULL) != 0) 219 return; 220 for (oidp = start; oidp < stop; oidp++) 221 sysctl_register_oid(*oidp); 222 } 223 224 static void 225 linker_file_unregister_sysctls(linker_file_t lf) 226 { 227 struct sysctl_oid **start, **stop, **oidp; 228 229 KLD_DPF(FILE, ("linker_file_unregister_sysctls: registering SYSCTLs for %s\n", 230 lf->filename)); 231 232 if (linker_file_lookup_set(lf, "sysctl_set", &start, &stop, NULL) != 0) 233 return; 234 for (oidp = start; oidp < stop; oidp++) 235 sysctl_unregister_oid(*oidp); 236 } 237 238 int 239 linker_load_file(const char* filename, linker_file_t* result) 240 { 241 linker_class_t lc; 242 linker_file_t lf; 243 int foundfile, error = 0; 244 char *koname = NULL; 245 246 /* Refuse to load modules if securelevel raised */ 247 if (securelevel > 0 || kernel_mem_readonly) 248 return EPERM; 249 250 lf = linker_find_file_by_name(filename); 251 if (lf) { 252 KLD_DPF(FILE, ("linker_load_file: file %s is already loaded, incrementing refs\n", filename)); 253 *result = lf; 254 lf->refs++; 255 goto out; 256 } 257 if (find_mod_metadata(filename)) { 258 if (linker_kernel_file) 259 ++linker_kernel_file->refs; 260 *result = linker_kernel_file; 261 goto out; 262 } 263 264 koname = kmalloc(strlen(filename) + 4, M_LINKER, M_WAITOK); 265 ksprintf(koname, "%s.ko", filename); 266 lf = NULL; 267 foundfile = 0; 268 TAILQ_FOREACH(lc, &classes, link) { 269 KLD_DPF(FILE, ("linker_load_file: trying to load %s as %s\n", 270 filename, lc->desc)); 271 272 error = lc->ops->load_file(koname, &lf); /* First with .ko */ 273 if (lf == NULL && error == ENOENT) 274 error = lc->ops->load_file(filename, &lf); /* Then try without */ 275 /* 276 * If we got something other than ENOENT, then it exists but we cannot 277 * load it for some other reason. 278 */ 279 if (error != ENOENT) 280 foundfile = 1; 281 if (lf) { 282 linker_file_register_sysctls(lf); 283 error = linker_file_sysinit(lf); 284 285 *result = lf; 286 goto out; 287 } 288 } 289 /* 290 * Less than ideal, but tells the user whether it failed to load or 291 * the module was not found. 292 */ 293 if (foundfile) { 294 /* 295 * Format not recognized or otherwise unloadable. 296 * When loading a module that is statically built into 297 * the kernel EEXIST percolates back up as the return 298 * value. Preserve this so that apps can recognize this 299 * special case. 300 */ 301 if (error != EEXIST) 302 error = ENOEXEC; 303 } else { 304 error = ENOENT; /* Nothing found */ 305 } 306 307 out: 308 if (koname) 309 kfree(koname, M_LINKER); 310 return error; 311 } 312 313 linker_file_t 314 linker_find_file_by_name(const char* filename) 315 { 316 linker_file_t lf = 0; 317 char *koname; 318 int i; 319 320 for (i = strlen(filename); i > 0 && filename[i-1] != '/'; --i) 321 ; 322 filename += i; 323 324 koname = kmalloc(strlen(filename) + 4, M_LINKER, M_WAITOK); 325 ksprintf(koname, "%s.ko", filename); 326 327 lockmgr(&lock, LK_SHARED); 328 TAILQ_FOREACH(lf, &linker_files, link) { 329 if (!strcmp(lf->filename, koname)) 330 break; 331 if (!strcmp(lf->filename, filename)) 332 break; 333 } 334 lockmgr(&lock, LK_RELEASE); 335 336 if (koname) 337 kfree(koname, M_LINKER); 338 return lf; 339 } 340 341 linker_file_t 342 linker_find_file_by_id(int fileid) 343 { 344 linker_file_t lf = 0; 345 346 lockmgr(&lock, LK_SHARED); 347 TAILQ_FOREACH(lf, &linker_files, link) 348 if (lf->id == fileid) 349 break; 350 lockmgr(&lock, LK_RELEASE); 351 352 return lf; 353 } 354 355 linker_file_t 356 linker_make_file(const char* pathname, void* priv, struct linker_file_ops* ops) 357 { 358 linker_file_t lf = 0; 359 int namelen; 360 const char *filename; 361 362 filename = rindex(pathname, '/'); 363 if (filename && filename[1]) 364 filename++; 365 else 366 filename = pathname; 367 368 KLD_DPF(FILE, ("linker_make_file: new file, filename=%s\n", filename)); 369 lockmgr(&lock, LK_EXCLUSIVE); 370 namelen = strlen(filename) + 1; 371 lf = kmalloc(sizeof(struct linker_file) + namelen, M_LINKER, M_WAITOK); 372 bzero(lf, sizeof(*lf)); 373 374 lf->refs = 1; 375 lf->userrefs = 0; 376 lf->flags = 0; 377 lf->filename = (char*) (lf + 1); 378 strcpy(lf->filename, filename); 379 lf->id = next_file_id++; 380 lf->ndeps = 0; 381 lf->deps = NULL; 382 STAILQ_INIT(&lf->common); 383 TAILQ_INIT(&lf->modules); 384 385 lf->priv = priv; 386 lf->ops = ops; 387 TAILQ_INSERT_TAIL(&linker_files, lf, link); 388 389 lockmgr(&lock, LK_RELEASE); 390 return lf; 391 } 392 393 int 394 linker_file_unload(linker_file_t file) 395 { 396 module_t mod, next; 397 struct common_symbol* cp; 398 int error = 0; 399 int i; 400 401 /* Refuse to unload modules if securelevel raised */ 402 if (securelevel > 0 || kernel_mem_readonly) 403 return EPERM; 404 405 KLD_DPF(FILE, ("linker_file_unload: lf->refs=%d\n", file->refs)); 406 lockmgr(&lock, LK_EXCLUSIVE); 407 if (file->refs == 1) { 408 KLD_DPF(FILE, ("linker_file_unload: file is unloading, informing modules\n")); 409 /* 410 * Temporarily bump file->refs to prevent recursive unloading 411 */ 412 ++file->refs; 413 414 /* 415 * Inform any modules associated with this file. 416 */ 417 mod = TAILQ_FIRST(&file->modules); 418 while (mod) { 419 /* 420 * Give the module a chance to veto the unload. Note that the 421 * act of unloading the module may cause other modules in the 422 * same file list to be unloaded recursively. 423 */ 424 if ((error = module_unload(mod)) != 0) { 425 KLD_DPF(FILE, ("linker_file_unload: module %x vetoes unload\n", 426 mod)); 427 lockmgr(&lock, LK_RELEASE); 428 file->refs--; 429 goto out; 430 } 431 432 /* 433 * Recursive relationships may prevent the release from 434 * immediately removing the module, or may remove other 435 * modules in the list. 436 */ 437 next = module_getfnext(mod); 438 module_release(mod); 439 mod = next; 440 } 441 442 /* 443 * Since we intend to destroy the file structure, we expect all 444 * modules to have been removed by now. 445 */ 446 for (mod = TAILQ_FIRST(&file->modules); 447 mod; 448 mod = module_getfnext(mod) 449 ) { 450 kprintf("linker_file_unload: module %p still has refs!\n", mod); 451 } 452 --file->refs; 453 } 454 455 file->refs--; 456 if (file->refs > 0) { 457 lockmgr(&lock, LK_RELEASE); 458 goto out; 459 } 460 461 /* Don't try to run SYSUNINITs if we are unloaded due to a link error */ 462 if (file->flags & LINKER_FILE_LINKED) { 463 linker_file_sysuninit(file); 464 linker_file_unregister_sysctls(file); 465 } 466 467 TAILQ_REMOVE(&linker_files, file, link); 468 lockmgr(&lock, LK_RELEASE); 469 470 for (i = 0; i < file->ndeps; i++) 471 linker_file_unload(file->deps[i]); 472 kfree(file->deps, M_LINKER); 473 474 for (cp = STAILQ_FIRST(&file->common); cp; 475 cp = STAILQ_FIRST(&file->common)) { 476 STAILQ_REMOVE(&file->common, cp, common_symbol, link); 477 kfree(cp, M_LINKER); 478 } 479 480 file->ops->unload(file); 481 kfree(file, M_LINKER); 482 483 out: 484 return error; 485 } 486 487 void 488 linker_file_add_dependancy(linker_file_t file, linker_file_t dep) 489 { 490 linker_file_t* newdeps; 491 492 newdeps = kmalloc((file->ndeps + 1) * sizeof(linker_file_t*), 493 M_LINKER, M_WAITOK | M_ZERO); 494 495 if (file->deps) { 496 bcopy(file->deps, newdeps, file->ndeps * sizeof(linker_file_t*)); 497 kfree(file->deps, M_LINKER); 498 } 499 file->deps = newdeps; 500 file->deps[file->ndeps] = dep; 501 file->ndeps++; 502 } 503 504 /* 505 * Locate a linker set and its contents. 506 * This is a helper function to avoid linker_if.h exposure elsewhere. 507 * Note: firstp and lastp are really void *** 508 */ 509 int 510 linker_file_lookup_set(linker_file_t file, const char *name, 511 void *firstp, void *lastp, int *countp) 512 { 513 return file->ops->lookup_set(file, name, firstp, lastp, countp); 514 } 515 516 int 517 linker_file_lookup_symbol(linker_file_t file, const char* name, int deps, caddr_t *raddr) 518 { 519 c_linker_sym_t sym; 520 linker_symval_t symval; 521 linker_file_t lf; 522 size_t common_size = 0; 523 int i; 524 525 KLD_DPF(SYM, ("linker_file_lookup_symbol: file=%x, name=%s, deps=%d\n", 526 file, name, deps)); 527 528 if (file->ops->lookup_symbol(file, name, &sym) == 0) { 529 file->ops->symbol_values(file, sym, &symval); 530 531 /* 532 * XXX Assume a common symbol if its value is 0 and it has a non-zero 533 * size, otherwise it could be an absolute symbol with a value of 0. 534 */ 535 if (symval.value == 0 && symval.size != 0) { 536 /* 537 * For commons, first look them up in the dependancies and 538 * only allocate space if not found there. 539 */ 540 common_size = symval.size; 541 } else { 542 KLD_DPF(SYM, ("linker_file_lookup_symbol: symbol.value=%x\n", symval.value)); 543 *raddr = symval.value; 544 return 0; 545 } 546 } 547 if (deps) { 548 for (i = 0; i < file->ndeps; i++) { 549 if (linker_file_lookup_symbol(file->deps[i], name, 0, raddr) == 0) { 550 KLD_DPF(SYM, ("linker_file_lookup_symbol: deps value=%x\n", *raddr)); 551 return 0; 552 } 553 } 554 555 /* If we have not found it in the dependencies, search globally */ 556 TAILQ_FOREACH(lf, &linker_files, link) { 557 /* But skip the current file if it's on the list */ 558 if (lf == file) 559 continue; 560 /* And skip the files we searched above */ 561 for (i = 0; i < file->ndeps; i++) 562 if (lf == file->deps[i]) 563 break; 564 if (i < file->ndeps) 565 continue; 566 if (linker_file_lookup_symbol(lf, name, 0, raddr) == 0) { 567 KLD_DPF(SYM, ("linker_file_lookup_symbol: global value=%x\n", *raddr)); 568 return 0; 569 } 570 } 571 } 572 573 if (common_size > 0) { 574 /* 575 * This is a common symbol which was not found in the 576 * dependancies. We maintain a simple common symbol table in 577 * the file object. 578 */ 579 struct common_symbol* cp; 580 581 STAILQ_FOREACH(cp, &file->common, link) 582 if (!strcmp(cp->name, name)) { 583 KLD_DPF(SYM, ("linker_file_lookup_symbol: old common value=%x\n", cp->address)); 584 *raddr = cp->address; 585 return 0; 586 } 587 588 /* 589 * Round the symbol size up to align. 590 */ 591 common_size = (common_size + sizeof(int) - 1) & -sizeof(int); 592 cp = kmalloc(sizeof(struct common_symbol) 593 + common_size 594 + strlen(name) + 1, 595 M_LINKER, M_WAITOK | M_ZERO); 596 597 cp->address = (caddr_t) (cp + 1); 598 cp->name = cp->address + common_size; 599 strcpy(cp->name, name); 600 bzero(cp->address, common_size); 601 STAILQ_INSERT_TAIL(&file->common, cp, link); 602 603 KLD_DPF(SYM, ("linker_file_lookup_symbol: new common value=%x\n", cp->address)); 604 *raddr = cp->address; 605 return 0; 606 } 607 608 #ifdef _KERNEL_VIRTUAL 609 *raddr = dlsym(RTLD_NEXT, name); 610 if (*raddr != NULL) { 611 KLD_DPF(SYM, ("linker_file_lookup_symbol: found dlsym=%x\n", *raddr)); 612 return 0; 613 } 614 #endif 615 616 KLD_DPF(SYM, ("linker_file_lookup_symbol: fail\n")); 617 return ENOENT; 618 } 619 620 #ifdef DDB 621 /* 622 * DDB Helpers. DDB has to look across multiple files with their own 623 * symbol tables and string tables. 624 * 625 * Note that we do not obey list locking protocols here. We really don't 626 * need DDB to hang because somebody's got the lock held. We'll take the 627 * chance that the files list is inconsistant instead. 628 */ 629 630 int 631 linker_ddb_lookup(const char *symstr, c_linker_sym_t *sym) 632 { 633 linker_file_t lf; 634 635 TAILQ_FOREACH(lf, &linker_files, link) { 636 if (lf->ops->lookup_symbol(lf, symstr, sym) == 0) 637 return 0; 638 } 639 return ENOENT; 640 } 641 642 int 643 linker_ddb_search_symbol(caddr_t value, c_linker_sym_t *sym, long *diffp) 644 { 645 linker_file_t lf; 646 u_long off = (uintptr_t)value; 647 u_long diff, bestdiff; 648 c_linker_sym_t best; 649 c_linker_sym_t es; 650 651 best = 0; 652 bestdiff = off; 653 TAILQ_FOREACH(lf, &linker_files, link) { 654 if (lf->ops->search_symbol(lf, value, &es, &diff) != 0) 655 continue; 656 if (es != 0 && diff < bestdiff) { 657 best = es; 658 bestdiff = diff; 659 } 660 if (bestdiff == 0) 661 break; 662 } 663 if (best) { 664 *sym = best; 665 *diffp = bestdiff; 666 return 0; 667 } else { 668 *sym = 0; 669 *diffp = off; 670 return ENOENT; 671 } 672 } 673 674 int 675 linker_ddb_symbol_values(c_linker_sym_t sym, linker_symval_t *symval) 676 { 677 linker_file_t lf; 678 679 TAILQ_FOREACH(lf, &linker_files, link) { 680 if (lf->ops->symbol_values(lf, sym, symval) == 0) 681 return 0; 682 } 683 return ENOENT; 684 } 685 686 #endif 687 688 /* 689 * Syscalls. 690 */ 691 692 int 693 sys_kldload(struct kldload_args *uap) 694 { 695 struct thread *td = curthread; 696 char* filename = NULL, *modulename; 697 linker_file_t lf; 698 int error = 0; 699 700 uap->sysmsg_result = -1; 701 702 if (securelevel > 0 || kernel_mem_readonly) /* redundant, but that's OK */ 703 return EPERM; 704 705 if ((error = priv_check(td, PRIV_ROOT)) != 0) 706 return error; 707 708 filename = kmalloc(MAXPATHLEN, M_TEMP, M_WAITOK); 709 if ((error = copyinstr(uap->file, filename, MAXPATHLEN, NULL)) != 0) 710 goto out; 711 712 /* Can't load more than one module with the same name */ 713 modulename = rindex(filename, '/'); 714 if (modulename == NULL) 715 modulename = filename; 716 else 717 modulename++; 718 if (linker_find_file_by_name(modulename)) { 719 error = EEXIST; 720 goto out; 721 } 722 723 if ((error = linker_load_file(filename, &lf)) != 0) 724 goto out; 725 726 lf->userrefs++; 727 uap->sysmsg_result = lf->id; 728 729 out: 730 if (filename) 731 kfree(filename, M_TEMP); 732 return error; 733 } 734 735 int 736 sys_kldunload(struct kldunload_args *uap) 737 { 738 struct thread *td = curthread; 739 linker_file_t lf; 740 int error = 0; 741 742 if (securelevel > 0 || kernel_mem_readonly) /* redundant, but that's OK */ 743 return EPERM; 744 745 if ((error = priv_check(td, PRIV_ROOT)) != 0) 746 return error; 747 748 lf = linker_find_file_by_id(uap->fileid); 749 if (lf) { 750 KLD_DPF(FILE, ("kldunload: lf->userrefs=%d\n", lf->userrefs)); 751 if (lf->userrefs == 0) { 752 kprintf("linkerunload: attempt to unload file that was loaded by the kernel\n"); 753 error = EBUSY; 754 goto out; 755 } 756 lf->userrefs--; 757 error = linker_file_unload(lf); 758 if (error) 759 lf->userrefs++; 760 } else 761 error = ENOENT; 762 763 out: 764 return error; 765 } 766 767 int 768 sys_kldfind(struct kldfind_args *uap) 769 { 770 char *filename = NULL, *modulename; 771 linker_file_t lf; 772 int error = 0; 773 774 uap->sysmsg_result = -1; 775 776 filename = kmalloc(MAXPATHLEN, M_TEMP, M_WAITOK); 777 if ((error = copyinstr(uap->file, filename, MAXPATHLEN, NULL)) != 0) 778 goto out; 779 780 modulename = rindex(filename, '/'); 781 if (modulename == NULL) 782 modulename = filename; 783 784 lf = linker_find_file_by_name(modulename); 785 if (lf) 786 uap->sysmsg_result = lf->id; 787 else 788 error = ENOENT; 789 790 out: 791 if (filename) 792 kfree(filename, M_TEMP); 793 return error; 794 } 795 796 int 797 sys_kldnext(struct kldnext_args *uap) 798 { 799 linker_file_t lf; 800 int error = 0; 801 802 if (uap->fileid == 0) { 803 if (TAILQ_FIRST(&linker_files)) 804 uap->sysmsg_result = TAILQ_FIRST(&linker_files)->id; 805 else 806 uap->sysmsg_result = 0; 807 return 0; 808 } 809 810 lf = linker_find_file_by_id(uap->fileid); 811 if (lf) { 812 if (TAILQ_NEXT(lf, link)) 813 uap->sysmsg_result = TAILQ_NEXT(lf, link)->id; 814 else 815 uap->sysmsg_result = 0; 816 } else 817 error = ENOENT; 818 819 return error; 820 } 821 822 int 823 sys_kldstat(struct kldstat_args *uap) 824 { 825 linker_file_t lf; 826 int error = 0; 827 int version; 828 struct kld_file_stat* stat; 829 int namelen; 830 831 lf = linker_find_file_by_id(uap->fileid); 832 if (!lf) { 833 error = ENOENT; 834 goto out; 835 } 836 837 stat = uap->stat; 838 839 /* 840 * Check the version of the user's structure. 841 */ 842 if ((error = copyin(&stat->version, &version, sizeof(version))) != 0) 843 goto out; 844 if (version != sizeof(struct kld_file_stat)) { 845 error = EINVAL; 846 goto out; 847 } 848 849 namelen = strlen(lf->filename) + 1; 850 if (namelen > MAXPATHLEN) 851 namelen = MAXPATHLEN; 852 if ((error = copyout(lf->filename, &stat->name[0], namelen)) != 0) 853 goto out; 854 if ((error = copyout(&lf->refs, &stat->refs, sizeof(int))) != 0) 855 goto out; 856 if ((error = copyout(&lf->id, &stat->id, sizeof(int))) != 0) 857 goto out; 858 if ((error = copyout(&lf->address, &stat->address, sizeof(caddr_t))) != 0) 859 goto out; 860 if ((error = copyout(&lf->size, &stat->size, sizeof(size_t))) != 0) 861 goto out; 862 863 uap->sysmsg_result = 0; 864 865 out: 866 return error; 867 } 868 869 int 870 sys_kldfirstmod(struct kldfirstmod_args *uap) 871 { 872 linker_file_t lf; 873 int error = 0; 874 875 lf = linker_find_file_by_id(uap->fileid); 876 if (lf) { 877 if (TAILQ_FIRST(&lf->modules)) 878 uap->sysmsg_result = module_getid(TAILQ_FIRST(&lf->modules)); 879 else 880 uap->sysmsg_result = 0; 881 } else 882 error = ENOENT; 883 884 return error; 885 } 886 887 int 888 sys_kldsym(struct kldsym_args *uap) 889 { 890 char *symstr = NULL; 891 c_linker_sym_t sym; 892 linker_symval_t symval; 893 linker_file_t lf; 894 struct kld_sym_lookup lookup; 895 int error = 0; 896 897 if ((error = copyin(uap->data, &lookup, sizeof(lookup))) != 0) 898 goto out; 899 if (lookup.version != sizeof(lookup) || uap->cmd != KLDSYM_LOOKUP) { 900 error = EINVAL; 901 goto out; 902 } 903 904 symstr = kmalloc(MAXPATHLEN, M_TEMP, M_WAITOK); 905 if ((error = copyinstr(lookup.symname, symstr, MAXPATHLEN, NULL)) != 0) 906 goto out; 907 908 if (uap->fileid != 0) { 909 lf = linker_find_file_by_id(uap->fileid); 910 if (lf == NULL) { 911 error = ENOENT; 912 goto out; 913 } 914 if (lf->ops->lookup_symbol(lf, symstr, &sym) == 0 && 915 lf->ops->symbol_values(lf, sym, &symval) == 0) { 916 lookup.symvalue = (uintptr_t)symval.value; 917 lookup.symsize = symval.size; 918 error = copyout(&lookup, uap->data, sizeof(lookup)); 919 } else 920 error = ENOENT; 921 } else { 922 TAILQ_FOREACH(lf, &linker_files, link) { 923 if (lf->ops->lookup_symbol(lf, symstr, &sym) == 0 && 924 lf->ops->symbol_values(lf, sym, &symval) == 0) { 925 lookup.symvalue = (uintptr_t)symval.value; 926 lookup.symsize = symval.size; 927 error = copyout(&lookup, uap->data, sizeof(lookup)); 928 break; 929 } 930 } 931 if (!lf) 932 error = ENOENT; 933 } 934 out: 935 if (symstr) 936 kfree(symstr, M_TEMP); 937 return error; 938 } 939 940 /* 941 * Look for module metadata in the static kernel 942 */ 943 struct mod_metadata * 944 find_mod_metadata(const char *modname) 945 { 946 int len; 947 struct mod_metadata **mdp; 948 struct mod_metadata *mdt; 949 950 /* 951 * Strip path prefixes and any dot extension. MDT_MODULE names 952 * are just the module name without a path or ".ko". 953 */ 954 for (len = strlen(modname) - 1; len >= 0; --len) { 955 if (modname[len] == '/') 956 break; 957 } 958 modname += len + 1; 959 for (len = 0; modname[len] && modname[len] != '.'; ++len) 960 ; 961 962 /* 963 * Look for the module declaration 964 */ 965 SET_FOREACH(mdp, modmetadata_set) { 966 mdt = *mdp; 967 if (mdt->md_type != MDT_MODULE) 968 continue; 969 if (strlen(mdt->md_cval) == len && 970 strncmp(mdt->md_cval, modname, len) == 0) { 971 return(mdt); 972 } 973 } 974 return(NULL); 975 } 976 977 /* 978 * Preloaded module support 979 */ 980 static void 981 linker_preload(void* arg) 982 { 983 caddr_t modptr; 984 char *modname; 985 char *modtype; 986 linker_file_t lf; 987 linker_class_t lc; 988 int error; 989 struct sysinit **sipp; 990 const moduledata_t *moddata; 991 struct sysinit **si_start, **si_stop; 992 993 modptr = NULL; 994 while ((modptr = preload_search_next_name(modptr)) != NULL) { 995 modname = (char *)preload_search_info(modptr, MODINFO_NAME); 996 modtype = (char *)preload_search_info(modptr, MODINFO_TYPE); 997 if (modname == NULL) { 998 kprintf("Preloaded module at %p does not have a name!\n", modptr); 999 continue; 1000 } 1001 if (modtype == NULL) { 1002 kprintf("Preloaded module at %p does not have a type!\n", modptr); 1003 continue; 1004 } 1005 1006 /* 1007 * This is a hack at the moment, but what's in FreeBSD-5 is even 1008 * worse so I'd rather the hack. 1009 */ 1010 kprintf("Preloaded %s \"%s\" at %p", modtype, modname, modptr); 1011 if (find_mod_metadata(modname)) { 1012 kprintf(" (ignored, already in static kernel)\n"); 1013 continue; 1014 } 1015 kprintf(".\n"); 1016 1017 lf = linker_find_file_by_name(modname); 1018 if (lf) { 1019 lf->refs++; 1020 lf->userrefs++; 1021 continue; 1022 } 1023 lf = NULL; 1024 TAILQ_FOREACH(lc, &classes, link) { 1025 error = lc->ops->load_file(modname, &lf); 1026 if (error) { 1027 lf = NULL; 1028 break; 1029 } 1030 } 1031 if (lf) { 1032 lf->userrefs++; 1033 1034 if (linker_file_lookup_set(lf, "sysinit_set", &si_start, &si_stop, NULL) == 0) { 1035 /* HACK ALERT! 1036 * This is to set the sysinit moduledata so that the module 1037 * can attach itself to the correct containing file. 1038 * The sysinit could be run at *any* time. 1039 */ 1040 for (sipp = si_start; sipp < si_stop; sipp++) { 1041 if ((*sipp)->func == module_register_init) { 1042 moddata = (*sipp)->udata; 1043 error = module_register(moddata, lf); 1044 if (error) 1045 kprintf("Preloaded %s \"%s\" failed to register: %d\n", 1046 modtype, modname, error); 1047 } 1048 } 1049 sysinit_add(si_start, si_stop); 1050 } 1051 linker_file_register_sysctls(lf); 1052 } 1053 } 1054 } 1055 1056 SYSINIT(preload, SI_BOOT2_KLD, SI_ORDER_MIDDLE, linker_preload, 0); 1057 1058 /* 1059 * Search for a not-loaded module by name. 1060 * 1061 * Modules may be found in the following locations: 1062 * 1063 * - preloaded (result is just the module name) 1064 * - on disk (result is full path to module) 1065 * 1066 * If the module name is qualified in any way (contains path, etc.) 1067 * the we simply return a copy of it. 1068 * 1069 * The search path can be manipulated via sysctl. Note that we use the ';' 1070 * character as a separator to be consistent with the bootloader. 1071 */ 1072 1073 static char linker_path[MAXPATHLEN] = "/boot;/boot/modules;/;/modules"; 1074 1075 SYSCTL_STRING(_kern, OID_AUTO, module_path, CTLFLAG_RW, linker_path, 1076 sizeof(linker_path), "module load search path"); 1077 TUNABLE_STR("module_path", linker_path, sizeof(linker_path)); 1078 1079 static char * 1080 linker_strdup(const char *str) 1081 { 1082 char *result; 1083 1084 result = kmalloc(strlen(str) + 1, M_LINKER, M_WAITOK); 1085 strcpy(result, str); 1086 return(result); 1087 } 1088 1089 char * 1090 linker_search_path(const char *name) 1091 { 1092 struct nlookupdata nd; 1093 char *cp, *ep, *result; 1094 size_t name_len, prefix_len; 1095 int sep; 1096 int error; 1097 enum vtype type; 1098 1099 /* qualified at all? */ 1100 if (index(name, '/')) 1101 return(linker_strdup(name)); 1102 1103 /* traverse the linker path */ 1104 cp = linker_path; 1105 name_len = strlen(name); 1106 for (;;) { 1107 1108 /* find the end of this component */ 1109 for (ep = cp; (*ep != 0) && (*ep != ';'); ep++) 1110 ; 1111 prefix_len = ep - cp; 1112 /* if this component doesn't end with a slash, add one */ 1113 if (ep == cp || *(ep - 1) != '/') 1114 sep = 1; 1115 else 1116 sep = 0; 1117 1118 /* 1119 * +2 : possible separator, plus terminator. 1120 */ 1121 result = kmalloc(prefix_len + name_len + 2, M_LINKER, M_WAITOK); 1122 1123 strncpy(result, cp, prefix_len); 1124 if (sep) 1125 result[prefix_len++] = '/'; 1126 strcpy(result + prefix_len, name); 1127 1128 /* 1129 * Attempt to open the file, and return the path if we succeed and it's 1130 * a regular file. 1131 */ 1132 error = nlookup_init(&nd, result, UIO_SYSSPACE, NLC_FOLLOW|NLC_LOCKVP); 1133 if (error == 0) 1134 error = vn_open(&nd, NULL, FREAD, 0); 1135 if (error == 0) { 1136 type = nd.nl_open_vp->v_type; 1137 if (type == VREG) { 1138 nlookup_done(&nd); 1139 return (result); 1140 } 1141 } 1142 nlookup_done(&nd); 1143 kfree(result, M_LINKER); 1144 1145 if (*ep == 0) 1146 break; 1147 cp = ep + 1; 1148 } 1149 return(NULL); 1150 } 1151