kern_linker.c revision 59751
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 59751 2000-04-29 13:19:31Z peter $ 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/module.h> 40#include <sys/linker.h> 41#include <sys/fcntl.h> 42#include <sys/libkern.h> 43#include <sys/namei.h> 44#include <sys/vnode.h> 45#include <sys/sysctl.h> 46 47#include <vm/vm_zone.h> 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 58MALLOC_DEFINE(M_LINKER, "linker", "kernel linker"); 59 60linker_file_t linker_kernel_file; 61 62static struct lock lock; /* lock for the file list */ 63static linker_class_list_t classes; 64static linker_file_list_t linker_files; 65static int next_file_id = 1; 66 67/* XXX wrong name; we're looking at version provision tags here, not modules */ 68typedef TAILQ_HEAD(, modlist) modlisthead_t; 69struct modlist { 70 TAILQ_ENTRY(modlist) link; /* chain together all modules */ 71 linker_file_t container; 72 const char *name; 73}; 74typedef struct modlist *modlist_t; 75static modlisthead_t found_modules; 76 77static char * 78linker_strdup(const char *str) 79{ 80 char *result; 81 82 if ((result = malloc((strlen(str) + 1), M_LINKER, M_WAITOK)) != NULL) 83 strcpy(result, str); 84 return(result); 85} 86 87static void 88linker_init(void* arg) 89{ 90 lockinit(&lock, PVM, "klink", 0, 0); 91 TAILQ_INIT(&classes); 92 TAILQ_INIT(&linker_files); 93} 94 95SYSINIT(linker, SI_SUB_KLD, SI_ORDER_FIRST, linker_init, 0); 96 97int 98linker_add_class(linker_class_t lc) 99{ 100 kobj_class_compile((kobj_class_t) lc); 101 TAILQ_INSERT_TAIL(&classes, lc, link); 102 return 0; 103} 104 105static void 106linker_file_sysinit(linker_file_t lf) 107{ 108 struct linker_set* sysinits; 109 struct sysinit** sipp; 110 struct sysinit** xipp; 111 struct sysinit* save; 112 113 KLD_DPF(FILE, ("linker_file_sysinit: calling SYSINITs for %s\n", 114 lf->filename)); 115 116 sysinits = (struct linker_set*) 117 linker_file_lookup_symbol(lf, "sysinit_set", 0); 118 119 KLD_DPF(FILE, ("linker_file_sysinit: SYSINITs %p\n", sysinits)); 120 if (!sysinits) 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 = (struct sysinit **)sysinits->ls_items; *sipp; sipp++) { 130 for (xipp = sipp + 1; *xipp; 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 = (struct sysinit **)sysinits->ls_items; *sipp; 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 linker_set* sysuninits; 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 sysuninits = (struct linker_set*) 167 linker_file_lookup_symbol(lf, "sysuninit_set", 0); 168 169 KLD_DPF(FILE, ("linker_file_sysuninit: SYSUNINITs %p\n", sysuninits)); 170 if (!sysuninits) 171 return; 172 173 /* 174 * Perform a reverse bubble sort of the system initialization objects 175 * by their subsystem (primary key) and order (secondary key). 176 * 177 * Since some things care about execution order, this is the 178 * operation which ensures continued function. 179 */ 180 for (sipp = (struct sysinit **)sysuninits->ls_items; *sipp; sipp++) { 181 for (xipp = sipp + 1; *xipp; xipp++) { 182 if ((*sipp)->subsystem >= (*xipp)->subsystem || 183 ((*sipp)->subsystem == (*xipp)->subsystem && 184 (*sipp)->order >= (*xipp)->order)) 185 continue; /* skip*/ 186 save = *sipp; 187 *sipp = *xipp; 188 *xipp = save; 189 } 190 } 191 192 /* 193 * Traverse the (now) ordered list of system initialization tasks. 194 * Perform each task, and continue on to the next task. 195 */ 196 for (sipp = (struct sysinit **)sysuninits->ls_items; *sipp; sipp++) { 197 if ((*sipp)->subsystem == SI_SUB_DUMMY) 198 continue; /* skip dummy task(s)*/ 199 200 /* Call function */ 201 (*((*sipp)->func))((*sipp)->udata); 202 } 203} 204 205static void 206linker_file_register_sysctls(linker_file_t lf) 207{ 208 struct linker_set* sysctls; 209 210 KLD_DPF(FILE, ("linker_file_register_sysctls: registering SYSCTLs for %s\n", 211 lf->filename)); 212 213 sysctls = (struct linker_set*) 214 linker_file_lookup_symbol(lf, "sysctl_set", 0); 215 216 KLD_DPF(FILE, ("linker_file_register_sysctls: SYSCTLs %p\n", sysctls)); 217 if (!sysctls) 218 return; 219 220 sysctl_register_set(sysctls); 221} 222 223static void 224linker_file_unregister_sysctls(linker_file_t lf) 225{ 226 struct linker_set* sysctls; 227 228 KLD_DPF(FILE, ("linker_file_unregister_sysctls: registering SYSCTLs for %s\n", 229 lf->filename)); 230 231 sysctls = (struct linker_set*) 232 linker_file_lookup_symbol(lf, "sysctl_set", 0); 233 234 KLD_DPF(FILE, ("linker_file_unregister_sysctls: SYSCTLs %p\n", sysctls)); 235 if (!sysctls) 236 return; 237 238 sysctl_unregister_set(sysctls); 239} 240 241static int 242linker_file_register_modules(linker_file_t lf) 243{ 244 int error, mcount; 245 struct linker_set *modules; 246 struct mod_metadata **mdpp; 247 const moduledata_t *moddata; 248 struct sysinit **sipp; 249 250 KLD_DPF(FILE, ("linker_file_register_modules: registering modules in %s\n", 251 lf->filename)); 252 253 modules = (struct linker_set*) 254 linker_file_lookup_symbol(lf, "modmetadata_set", 0); 255 mcount = 0; 256 if (modules) { 257 for (mdpp = (struct mod_metadata**)modules->ls_items; *mdpp; mdpp++) { 258 if ((*mdpp)->md_type != MDT_MODULE) 259 continue; 260 mcount++; 261 moddata = (*mdpp)->md_data; 262 KLD_DPF(FILE, ("Registering module %s in %s\n", 263 moddata->name, lf->filename)); 264 error = module_register(moddata, lf); 265 if (error) 266 printf("Module %s failed to register: %d\n", moddata->name, error); 267 } 268 } 269 if (mcount) 270 return mcount; /* Do not mix old and new style */ 271 272 /* Hack - handle old kld's without metadata */ 273 modules = (struct linker_set*) 274 linker_file_lookup_symbol(lf, "sysinit_set", 0); 275 if (modules) { 276 for (sipp = (struct sysinit **)modules->ls_items; *sipp; sipp++) { 277 if ((*sipp)->func != module_register_init) 278 continue; 279 mcount++; 280 moddata = (*sipp)->udata; 281 printf("Old-style KLD file %s found\n", moddata->name); 282 error = module_register(moddata, lf); 283 if (error) 284 printf("Old-style KLD file %s failed to register: %d\n", moddata->name, error); 285 } 286 } 287 return mcount; 288} 289 290static void 291linker_init_kernel_modules(void) 292{ 293 linker_file_register_modules(linker_kernel_file); 294} 295 296SYSINIT(linker_kernel, SI_SUB_KLD, SI_ORDER_ANY, linker_init_kernel_modules, 0); 297 298int 299linker_load_file(const char* filename, linker_file_t* result) 300{ 301 linker_class_t lc; 302 linker_file_t lf; 303 int foundfile, error = 0; 304 305 lf = linker_find_file_by_name(filename); 306 if (lf) { 307 KLD_DPF(FILE, ("linker_load_file: file %s is already loaded, incrementing refs\n", filename)); 308 *result = lf; 309 lf->refs++; 310 goto out; 311 } 312 313 lf = NULL; 314 foundfile = 0; 315 for (lc = TAILQ_FIRST(&classes); lc; lc = TAILQ_NEXT(lc, link)) { 316 KLD_DPF(FILE, ("linker_load_file: trying to load %s as %s\n", 317 filename, lc->desc)); 318 error = LINKER_LOAD_FILE(lc, filename, &lf); 319 /* 320 * If we got something other than ENOENT, then it exists but we cannot 321 * load it for some other reason. 322 */ 323 if (error != ENOENT) 324 foundfile = 1; 325 if (lf) { 326 linker_file_register_modules(lf); 327 linker_file_register_sysctls(lf); 328 linker_file_sysinit(lf); 329 lf->flags |= LINKER_FILE_LINKED; 330 331 *result = lf; 332 error = 0; 333 goto out; 334 } 335 } 336 /* 337 * Less than ideal, but tells the user whether it failed to load or 338 * the module was not found. 339 */ 340 if (foundfile) 341 error = ENOEXEC; /* Format not recognised (or unloadable) */ 342 else 343 error = ENOENT; /* Nothing found */ 344 345out: 346 return error; 347} 348 349linker_file_t 350linker_find_file_by_name(const char* filename) 351{ 352 linker_file_t lf = 0; 353 char *koname; 354 355 koname = malloc(strlen(filename) + 4, M_LINKER, M_WAITOK); 356 if (koname == NULL) 357 goto out; 358 sprintf(koname, "%s.ko", filename); 359 360 lockmgr(&lock, LK_SHARED, 0, curproc); 361 for (lf = TAILQ_FIRST(&linker_files); lf; lf = TAILQ_NEXT(lf, link)) { 362 if (!strcmp(lf->filename, koname)) 363 break; 364 if (!strcmp(lf->filename, filename)) 365 break; 366 } 367 lockmgr(&lock, LK_RELEASE, 0, curproc); 368 369out: 370 if (koname) 371 free(koname, M_LINKER); 372 return lf; 373} 374 375linker_file_t 376linker_find_file_by_id(int fileid) 377{ 378 linker_file_t lf = 0; 379 380 lockmgr(&lock, LK_SHARED, 0, curproc); 381 for (lf = TAILQ_FIRST(&linker_files); lf; lf = TAILQ_NEXT(lf, link)) 382 if (lf->id == fileid) 383 break; 384 lockmgr(&lock, LK_RELEASE, 0, curproc); 385 386 return lf; 387} 388 389linker_file_t 390linker_make_file(const char* pathname, linker_class_t lc) 391{ 392 linker_file_t lf = 0; 393 const char *filename; 394 395 filename = linker_basename(pathname); 396 397 KLD_DPF(FILE, ("linker_make_file: new file, filename=%s\n", filename)); 398 lockmgr(&lock, LK_EXCLUSIVE, 0, curproc); 399 lf = (linker_file_t) kobj_create((kobj_class_t) lc, M_LINKER, M_WAITOK); 400 if (!lf) 401 goto out; 402 403 lf->refs = 1; 404 lf->userrefs = 0; 405 lf->flags = 0; 406 lf->filename = linker_strdup(filename); 407 lf->id = next_file_id++; 408 lf->ndeps = 0; 409 lf->deps = NULL; 410 STAILQ_INIT(&lf->common); 411 TAILQ_INIT(&lf->modules); 412 413 TAILQ_INSERT_TAIL(&linker_files, lf, link); 414 415out: 416 lockmgr(&lock, LK_RELEASE, 0, curproc); 417 return lf; 418} 419 420int 421linker_file_unload(linker_file_t file) 422{ 423 module_t mod, next; 424 modlist_t ml, nextml; 425 struct common_symbol* cp; 426 int error = 0; 427 int i; 428 429 KLD_DPF(FILE, ("linker_file_unload: lf->refs=%d\n", file->refs)); 430 lockmgr(&lock, LK_EXCLUSIVE, 0, curproc); 431 if (file->refs == 1) { 432 KLD_DPF(FILE, ("linker_file_unload: file is unloading, informing modules\n")); 433 /* 434 * Inform any modules associated with this file. 435 */ 436 for (mod = TAILQ_FIRST(&file->modules); mod; mod = next) { 437 next = module_getfnext(mod); 438 439 /* 440 * Give the module a chance to veto the unload. 441 */ 442 if ((error = module_unload(mod)) != 0) { 443 KLD_DPF(FILE, ("linker_file_unload: module %x vetoes unload\n", 444 mod)); 445 lockmgr(&lock, LK_RELEASE, 0, curproc); 446 goto out; 447 } 448 449 module_release(mod); 450 } 451 } 452 453 file->refs--; 454 if (file->refs > 0) { 455 lockmgr(&lock, LK_RELEASE, 0, curproc); 456 goto out; 457 } 458 459 for (ml = TAILQ_FIRST(&found_modules); ml; ml = nextml) { 460 nextml = TAILQ_NEXT(ml, link); 461 if (ml->container == file) { 462 TAILQ_REMOVE(&found_modules, ml, link); 463 } 464 } 465 466 /* Don't try to run SYSUNINITs if we are unloaded due to a link error */ 467 if (file->flags & LINKER_FILE_LINKED) { 468 linker_file_sysuninit(file); 469 linker_file_unregister_sysctls(file); 470 } 471 472 TAILQ_REMOVE(&linker_files, file, link); 473 lockmgr(&lock, LK_RELEASE, 0, curproc); 474 475 if (file->deps) { 476 for (i = 0; i < file->ndeps; i++) 477 linker_file_unload(file->deps[i]); 478 free(file->deps, M_LINKER); 479 file->deps = NULL; 480 } 481 482 for (cp = STAILQ_FIRST(&file->common); cp; 483 cp = STAILQ_FIRST(&file->common)) { 484 STAILQ_REMOVE(&file->common, cp, common_symbol, link); 485 free(cp, M_LINKER); 486 } 487 488 LINKER_UNLOAD(file); 489 if (file->filename) { 490 free(file->filename, M_LINKER); 491 file->filename = NULL; 492 } 493 kobj_delete((kobj_t) file, M_LINKER); 494 495out: 496 return error; 497} 498 499int 500linker_file_add_dependancy(linker_file_t file, linker_file_t dep) 501{ 502 linker_file_t* newdeps; 503 504 newdeps = malloc((file->ndeps + 1) * sizeof(linker_file_t*), 505 M_LINKER, M_WAITOK); 506 if (newdeps == NULL) 507 return ENOMEM; 508 bzero(newdeps, (file->ndeps + 1) * sizeof(linker_file_t*)); 509 510 if (file->deps) { 511 bcopy(file->deps, newdeps, file->ndeps * sizeof(linker_file_t*)); 512 free(file->deps, M_LINKER); 513 } 514 file->deps = newdeps; 515 file->deps[file->ndeps] = dep; 516 file->ndeps++; 517 518 return 0; 519} 520 521caddr_t 522linker_file_lookup_symbol(linker_file_t file, const char* name, int deps) 523{ 524 c_linker_sym_t sym; 525 linker_symval_t symval; 526 caddr_t address; 527 size_t common_size = 0; 528 int i; 529 530 KLD_DPF(SYM, ("linker_file_lookup_symbol: file=%x, name=%s, deps=%d\n", 531 file, name, deps)); 532 533 if (LINKER_LOOKUP_SYMBOL(file, name, &sym) == 0) { 534 LINKER_SYMBOL_VALUES(file, sym, &symval); 535 if (symval.value == 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 return symval.value; 544 } 545 } 546 547 if (deps) { 548 for (i = 0; i < file->ndeps; i++) { 549 address = linker_file_lookup_symbol(file->deps[i], name, 0); 550 if (address) { 551 KLD_DPF(SYM, ("linker_file_lookup_symbol: deps value=%x\n", address)); 552 return address; 553 } 554 } 555 } 556 557 if (common_size > 0) { 558 /* 559 * This is a common symbol which was not found in the 560 * dependancies. We maintain a simple common symbol table in 561 * the file object. 562 */ 563 struct common_symbol* cp; 564 565 for (cp = STAILQ_FIRST(&file->common); cp; 566 cp = STAILQ_NEXT(cp, link)) 567 if (!strcmp(cp->name, name)) { 568 KLD_DPF(SYM, ("linker_file_lookup_symbol: old common value=%x\n", cp->address)); 569 return cp->address; 570 } 571 572 /* 573 * Round the symbol size up to align. 574 */ 575 common_size = (common_size + sizeof(int) - 1) & -sizeof(int); 576 cp = malloc(sizeof(struct common_symbol) 577 + common_size 578 + strlen(name) + 1, 579 M_LINKER, M_WAITOK); 580 if (!cp) { 581 KLD_DPF(SYM, ("linker_file_lookup_symbol: nomem\n")); 582 return 0; 583 } 584 bzero(cp, sizeof(struct common_symbol) + common_size + strlen(name)+ 1); 585 586 cp->address = (caddr_t) (cp + 1); 587 cp->name = cp->address + common_size; 588 strcpy(cp->name, name); 589 bzero(cp->address, common_size); 590 STAILQ_INSERT_TAIL(&file->common, cp, link); 591 592 KLD_DPF(SYM, ("linker_file_lookup_symbol: new common value=%x\n", cp->address)); 593 return cp->address; 594 } 595 596 KLD_DPF(SYM, ("linker_file_lookup_symbol: fail\n")); 597 return 0; 598} 599 600#ifdef DDB 601/* 602 * DDB Helpers. DDB has to look across multiple files with their own 603 * symbol tables and string tables. 604 * 605 * Note that we do not obey list locking protocols here. We really don't 606 * need DDB to hang because somebody's got the lock held. We'll take the 607 * chance that the files list is inconsistant instead. 608 */ 609 610int 611linker_ddb_lookup(const char *symstr, c_linker_sym_t *sym) 612{ 613 linker_file_t lf; 614 615 for (lf = TAILQ_FIRST(&linker_files); lf; lf = TAILQ_NEXT(lf, link)) { 616 if (LINKER_LOOKUP_SYMBOL(lf, symstr, sym) == 0) 617 return 0; 618 } 619 return ENOENT; 620} 621 622int 623linker_ddb_search_symbol(caddr_t value, c_linker_sym_t *sym, long *diffp) 624{ 625 linker_file_t lf; 626 u_long off = (uintptr_t)value; 627 u_long diff, bestdiff; 628 c_linker_sym_t best; 629 c_linker_sym_t es; 630 631 best = 0; 632 bestdiff = off; 633 for (lf = TAILQ_FIRST(&linker_files); lf; lf = TAILQ_NEXT(lf, link)) { 634 if (LINKER_SEARCH_SYMBOL(lf, value, &es, &diff) != 0) 635 continue; 636 if (es != 0 && diff < bestdiff) { 637 best = es; 638 bestdiff = diff; 639 } 640 if (bestdiff == 0) 641 break; 642 } 643 if (best) { 644 *sym = best; 645 *diffp = bestdiff; 646 return 0; 647 } else { 648 *sym = 0; 649 *diffp = off; 650 return ENOENT; 651 } 652} 653 654int 655linker_ddb_symbol_values(c_linker_sym_t sym, linker_symval_t *symval) 656{ 657 linker_file_t lf; 658 659 for (lf = TAILQ_FIRST(&linker_files); lf; lf = TAILQ_NEXT(lf, link)) { 660 if (LINKER_SYMBOL_VALUES(lf, sym, symval) == 0) 661 return 0; 662 } 663 return ENOENT; 664} 665 666#endif 667 668/* 669 * Syscalls. 670 */ 671 672int 673kldload(struct proc* p, struct kldload_args* uap) 674{ 675 char* pathname, *realpath; 676 const char *filename; 677 linker_file_t lf; 678 int error = 0; 679 680 p->p_retval[0] = -1; 681 682 if (securelevel > 0) 683 return EPERM; 684 685 if ((error = suser(p)) != 0) 686 return error; 687 688 realpath = NULL; 689 pathname = malloc(MAXPATHLEN, M_TEMP, M_WAITOK); 690 if ((error = copyinstr(SCARG(uap, file), pathname, MAXPATHLEN, NULL)) != 0) 691 goto out; 692 693 realpath = linker_search_path(pathname); 694 if (realpath == NULL) { 695 error = ENOENT; 696 goto out; 697 } 698 /* Can't load more than one file with the same name */ 699 filename = linker_basename(realpath); 700 if (linker_find_file_by_name(filename)) { 701 error = EEXIST; 702 goto out; 703 } 704 705 if ((error = linker_load_file(realpath, &lf)) != 0) 706 goto out; 707 708 lf->userrefs++; 709 p->p_retval[0] = lf->id; 710 711out: 712 if (pathname) 713 free(pathname, M_TEMP); 714 if (realpath) 715 free(realpath, M_LINKER); 716 return error; 717} 718 719int 720kldunload(struct proc* p, struct kldunload_args* uap) 721{ 722 linker_file_t lf; 723 int error = 0; 724 725 if (securelevel > 0) 726 return EPERM; 727 728 if ((error = suser(p)) != 0) 729 return error; 730 731 lf = linker_find_file_by_id(SCARG(uap, fileid)); 732 if (lf) { 733 KLD_DPF(FILE, ("kldunload: lf->userrefs=%d\n", lf->userrefs)); 734 if (lf->userrefs == 0) { 735 printf("kldunload: attempt to unload file that was loaded by the kernel\n"); 736 error = EBUSY; 737 goto out; 738 } 739 lf->userrefs--; 740 error = linker_file_unload(lf); 741 if (error) 742 lf->userrefs++; 743 } else 744 error = ENOENT; 745 746out: 747 return error; 748} 749 750int 751kldfind(struct proc* p, struct kldfind_args* uap) 752{ 753 char* pathname; 754 const char *filename; 755 linker_file_t lf; 756 int error = 0; 757 758 p->p_retval[0] = -1; 759 760 pathname = malloc(MAXPATHLEN, M_TEMP, M_WAITOK); 761 if ((error = copyinstr(SCARG(uap, file), pathname, MAXPATHLEN, NULL)) != 0) 762 goto out; 763 764 filename = linker_basename(pathname); 765 766 lf = linker_find_file_by_name(filename); 767 if (lf) 768 p->p_retval[0] = lf->id; 769 else 770 error = ENOENT; 771 772out: 773 if (pathname) 774 free(pathname, M_TEMP); 775 return error; 776} 777 778int 779kldnext(struct proc* p, struct kldnext_args* uap) 780{ 781 linker_file_t lf; 782 int error = 0; 783 784 if (SCARG(uap, fileid) == 0) { 785 if (TAILQ_FIRST(&linker_files)) 786 p->p_retval[0] = TAILQ_FIRST(&linker_files)->id; 787 else 788 p->p_retval[0] = 0; 789 return 0; 790 } 791 792 lf = linker_find_file_by_id(SCARG(uap, fileid)); 793 if (lf) { 794 if (TAILQ_NEXT(lf, link)) 795 p->p_retval[0] = TAILQ_NEXT(lf, link)->id; 796 else 797 p->p_retval[0] = 0; 798 } else 799 error = ENOENT; 800 801 return error; 802} 803 804int 805kldstat(struct proc* p, struct kldstat_args* uap) 806{ 807 linker_file_t lf; 808 int error = 0; 809 int version; 810 struct kld_file_stat* stat; 811 int namelen; 812 813 lf = linker_find_file_by_id(SCARG(uap, fileid)); 814 if (!lf) { 815 error = ENOENT; 816 goto out; 817 } 818 819 stat = SCARG(uap, stat); 820 821 /* 822 * Check the version of the user's structure. 823 */ 824 if ((error = copyin(&stat->version, &version, sizeof(version))) != 0) 825 goto out; 826 if (version != sizeof(struct kld_file_stat)) { 827 error = EINVAL; 828 goto out; 829 } 830 831 namelen = strlen(lf->filename) + 1; 832 if (namelen > MAXPATHLEN) 833 namelen = MAXPATHLEN; 834 if ((error = copyout(lf->filename, &stat->name[0], namelen)) != 0) 835 goto out; 836 if ((error = copyout(&lf->refs, &stat->refs, sizeof(int))) != 0) 837 goto out; 838 if ((error = copyout(&lf->id, &stat->id, sizeof(int))) != 0) 839 goto out; 840 if ((error = copyout(&lf->address, &stat->address, sizeof(caddr_t))) != 0) 841 goto out; 842 if ((error = copyout(&lf->size, &stat->size, sizeof(size_t))) != 0) 843 goto out; 844 845 p->p_retval[0] = 0; 846 847out: 848 return error; 849} 850 851int 852kldfirstmod(struct proc* p, struct kldfirstmod_args* uap) 853{ 854 linker_file_t lf; 855 int error = 0; 856 857 lf = linker_find_file_by_id(SCARG(uap, fileid)); 858 if (lf) { 859 if (TAILQ_FIRST(&lf->modules)) 860 p->p_retval[0] = module_getid(TAILQ_FIRST(&lf->modules)); 861 else 862 p->p_retval[0] = 0; 863 } else 864 error = ENOENT; 865 866 return error; 867} 868 869int 870kldsym(struct proc *p, struct kldsym_args *uap) 871{ 872 char *symstr = NULL; 873 c_linker_sym_t sym; 874 linker_symval_t symval; 875 linker_file_t lf; 876 struct kld_sym_lookup lookup; 877 int error = 0; 878 879 if ((error = copyin(SCARG(uap, data), &lookup, sizeof(lookup))) != 0) 880 goto out; 881 if (lookup.version != sizeof(lookup) || SCARG(uap, cmd) != KLDSYM_LOOKUP) { 882 error = EINVAL; 883 goto out; 884 } 885 886 symstr = malloc(MAXPATHLEN, M_TEMP, M_WAITOK); 887 if ((error = copyinstr(lookup.symname, symstr, MAXPATHLEN, NULL)) != 0) 888 goto out; 889 890 if (SCARG(uap, fileid) != 0) { 891 lf = linker_find_file_by_id(SCARG(uap, fileid)); 892 if (lf == NULL) { 893 error = ENOENT; 894 goto out; 895 } 896 if (LINKER_LOOKUP_SYMBOL(lf, symstr, &sym) == 0 && 897 LINKER_SYMBOL_VALUES(lf, sym, &symval) == 0) { 898 lookup.symvalue = (uintptr_t)symval.value; 899 lookup.symsize = symval.size; 900 error = copyout(&lookup, SCARG(uap, data), sizeof(lookup)); 901 } else 902 error = ENOENT; 903 } else { 904 for (lf = TAILQ_FIRST(&linker_files); lf; lf = TAILQ_NEXT(lf, link)) { 905 if (LINKER_LOOKUP_SYMBOL(lf, symstr, &sym) == 0 && 906 LINKER_SYMBOL_VALUES(lf, sym, &symval) == 0) { 907 lookup.symvalue = (uintptr_t)symval.value; 908 lookup.symsize = symval.size; 909 error = copyout(&lookup, SCARG(uap, data), sizeof(lookup)); 910 break; 911 } 912 } 913 if (!lf) 914 error = ENOENT; 915 } 916out: 917 if (symstr) 918 free(symstr, M_TEMP); 919 return error; 920} 921 922/* 923 * Preloaded module support 924 */ 925 926static modlist_t 927modlist_lookup(const char *name) 928{ 929 modlist_t mod; 930 931 for (mod = TAILQ_FIRST(&found_modules); mod; mod = TAILQ_NEXT(mod, link)) { 932 if (!strcmp(mod->name, name)) 933 return mod; 934 } 935 return NULL; 936} 937 938/* 939 * This routine is cheap and nasty but will work for data pointers. 940 */ 941static void * 942linker_reloc_ptr(linker_file_t lf, void *offset) 943{ 944 return lf->address + (uintptr_t)offset; 945} 946 947static void 948linker_preload(void* arg) 949{ 950 caddr_t modptr; 951 char *modname; 952 char *modtype; 953 linker_file_t lf; 954 linker_class_t lc; 955 int error, mcount; 956 struct linker_set *sysinits; 957 linker_file_list_t loaded_files; 958 linker_file_list_t depended_files; 959 struct linker_set *deps; 960 struct mod_metadata *mp; 961 int i; 962 int resolves; 963 modlist_t mod; 964 965 TAILQ_INIT(&loaded_files); 966 TAILQ_INIT(&depended_files); 967 TAILQ_INIT(&found_modules); 968 error = 0; 969 970 modptr = NULL; 971 while ((modptr = preload_search_next_name(modptr)) != NULL) { 972 modname = (char *)preload_search_info(modptr, MODINFO_NAME); 973 modtype = (char *)preload_search_info(modptr, MODINFO_TYPE); 974 if (modname == NULL) { 975 printf("Preloaded module at %p does not have a name!\n", modptr); 976 continue; 977 } 978 if (modtype == NULL) { 979 printf("Preloaded module at %p does not have a type!\n", modptr); 980 continue; 981 } 982 printf("Preloaded %s \"%s\" at %p.\n", modtype, modname, modptr); 983 lf = NULL; 984 for (lc = TAILQ_FIRST(&classes); lc; lc = TAILQ_NEXT(lc, link)) { 985 error = LINKER_LINK_PRELOAD(lc, modname, &lf); 986 if (error) { 987 lf = NULL; 988 break; 989 } 990 } 991 if (lf) 992 TAILQ_INSERT_TAIL(&loaded_files, lf, loaded); 993 } 994 995 /* 996 * First get a list of stuff in the kernel. 997 */ 998 deps = (struct linker_set*) 999 linker_file_lookup_symbol(linker_kernel_file, MDT_SETNAME, 0); 1000 if (deps) { 1001 for (i = 0; i < deps->ls_length; i++) { 1002 mp = deps->ls_items[i]; 1003 if (mp->md_type != MDT_VERSION) 1004 continue; 1005 modname = mp->md_cval; 1006 if (modlist_lookup(modname) != NULL) { 1007 printf("module %s already present!\n", modname); 1008 /* XXX what can we do? this is a build error. :-( */ 1009 continue; 1010 } 1011 mod = malloc(sizeof(struct modlist), M_LINKER, M_NOWAIT); 1012 if (mod == NULL) 1013 panic("no memory for module list"); 1014 bzero(mod, sizeof(*mod)); 1015 mod->container = linker_kernel_file; 1016 mod->name = modname; 1017 TAILQ_INSERT_TAIL(&found_modules, mod, link); 1018 } 1019 } 1020 1021 /* 1022 * this is a once-off kinky bubble sort 1023 * resolve relocation dependency requirements 1024 */ 1025restart: 1026 for (lf = TAILQ_FIRST(&loaded_files); lf; lf = TAILQ_NEXT(lf, loaded)) { 1027 deps = (struct linker_set*) 1028 linker_file_lookup_symbol(lf, MDT_SETNAME, 0); 1029 /* 1030 * First, look to see if we would successfully link with this stuff. 1031 */ 1032 resolves = 1; /* unless we know otherwise */ 1033 if (deps) { 1034 for (i = 0; i < deps->ls_length; i++) { 1035 mp = linker_reloc_ptr(lf, deps->ls_items[i]); 1036 if (mp->md_type != MDT_DEPEND) 1037 continue; 1038 modname = linker_reloc_ptr(lf, mp->md_cval); 1039 if (modlist_lookup(modname) == NULL) { 1040 /* ok, the module isn't here yet, we are not finished */ 1041 resolves = 0; 1042 } 1043 } 1044 } 1045 /* 1046 * OK, if we found our modules, we can link. So, "provide" the 1047 * modules inside and add it to the end of the link order list. 1048 */ 1049 if (resolves) { 1050 if (deps) { 1051 for (i = 0; i < deps->ls_length; i++) { 1052 mp = linker_reloc_ptr(lf, deps->ls_items[i]); 1053 if (mp->md_type != MDT_VERSION) 1054 continue; 1055 modname = linker_reloc_ptr(lf, mp->md_cval); 1056 if (modlist_lookup(modname) != NULL) { 1057 printf("module %s already present!\n", modname); 1058 linker_file_unload(lf); 1059 TAILQ_REMOVE(&loaded_files, lf, loaded); 1060 goto restart; /* we changed the tailq next ptr */ 1061 } 1062 mod = malloc(sizeof(struct modlist), M_LINKER, M_NOWAIT); 1063 if (mod == NULL) 1064 panic("no memory for module list"); 1065 bzero(mod, sizeof(*mod)); 1066 mod->container = lf; 1067 mod->name = modname; 1068 TAILQ_INSERT_TAIL(&found_modules, mod, link); 1069 } 1070 } 1071 TAILQ_REMOVE(&loaded_files, lf, loaded); 1072 TAILQ_INSERT_TAIL(&depended_files, lf, loaded); 1073 /* 1074 * Since we provided modules, we need to restart the sort so 1075 * that the previous files that depend on us have a chance. 1076 * Also, we've busted the tailq next pointer with the REMOVE. 1077 */ 1078 goto restart; 1079 } 1080 } 1081 1082 /* 1083 * At this point, we check to see what could not be resolved.. 1084 */ 1085 for (lf = TAILQ_FIRST(&loaded_files); lf; lf = TAILQ_NEXT(lf, loaded)) { 1086 printf("KLD file %s is missing dependencies\n", lf->filename); 1087 linker_file_unload(lf); 1088 TAILQ_REMOVE(&loaded_files, lf, loaded); 1089 } 1090 1091 /* 1092 * We made it. Finish off the linking in the order we determined. 1093 */ 1094 for (lf = TAILQ_FIRST(&depended_files); lf; lf = TAILQ_NEXT(lf, loaded)) { 1095 if (linker_kernel_file) { 1096 linker_kernel_file->refs++; 1097 error = linker_file_add_dependancy(lf, linker_kernel_file); 1098 if (error) 1099 panic("cannot add dependency"); 1100 } 1101 lf->userrefs++; /* so we can (try to) kldunload it */ 1102 deps = (struct linker_set*) 1103 linker_file_lookup_symbol(lf, MDT_SETNAME, 0); 1104 if (deps) { 1105 for (i = 0; i < deps->ls_length; i++) { 1106 mp = linker_reloc_ptr(lf, deps->ls_items[i]); 1107 if (mp->md_type != MDT_DEPEND) 1108 continue; 1109 modname = linker_reloc_ptr(lf, mp->md_cval); 1110 mod = modlist_lookup(modname); 1111 mod->container->refs++; 1112 error = linker_file_add_dependancy(lf, mod->container); 1113 if (error) 1114 panic("cannot add dependency"); 1115 } 1116 } 1117 1118 /* Now do relocation etc using the symbol search paths established by the dependencies */ 1119 error = LINKER_LINK_PRELOAD_FINISH(lf); 1120 if (error) { 1121 printf("KLD file %s - could not finalize loading\n", lf->filename); 1122 linker_file_unload(lf); 1123 continue; 1124 } 1125 1126 mcount = linker_file_register_modules(lf); 1127 sysinits = (struct linker_set*) 1128 linker_file_lookup_symbol(lf, "sysinit_set", 0); 1129 if (sysinits) 1130 sysinit_add((struct sysinit **)sysinits->ls_items); 1131 linker_file_register_sysctls(lf); 1132 lf->flags |= LINKER_FILE_LINKED; 1133 } 1134 /* woohoo! we made it! */ 1135} 1136 1137SYSINIT(preload, SI_SUB_KLD, SI_ORDER_MIDDLE, linker_preload, 0); 1138 1139/* 1140 * Search for a not-loaded module by name. 1141 * 1142 * Modules may be found in the following locations: 1143 * 1144 * - preloaded (result is just the module name) 1145 * - on disk (result is full path to module) 1146 * 1147 * If the module name is qualified in any way (contains path, etc.) 1148 * the we simply return a copy of it. 1149 * 1150 * The search path can be manipulated via sysctl. Note that we use the ';' 1151 * character as a separator to be consistent with the bootloader. 1152 */ 1153 1154static char linker_path[MAXPATHLEN] = "/;/boot/;/modules/"; 1155 1156SYSCTL_STRING(_kern, OID_AUTO, module_path, CTLFLAG_RW, linker_path, 1157 sizeof(linker_path), "module load search path"); 1158 1159static char *linker_ext_list[] = { 1160 ".ko", 1161 "", 1162 NULL 1163}; 1164 1165static char * 1166linker_search_path(const char *name) 1167{ 1168 struct nameidata nd; 1169 struct proc *p = curproc; /* XXX */ 1170 char *cp, *ep, *result, **cpp; 1171 int error, extlen, len; 1172 enum vtype type; 1173 1174 /* qualified at all? */ 1175 if (index(name, '/')) 1176 return(linker_strdup(name)); 1177 1178 extlen = 0; 1179 for (cpp = linker_ext_list; *cpp; cpp++) { 1180 len = strlen(*cpp); 1181 if (len > extlen) 1182 extlen = len; 1183 } 1184 extlen++; /* trailing '\0' */ 1185 1186 /* traverse the linker path */ 1187 cp = linker_path; 1188 len = strlen(name); 1189 for (;;) { 1190 1191 /* find the end of this component */ 1192 for (ep = cp; (*ep != 0) && (*ep != ';'); ep++) 1193 ; 1194 result = malloc((len + (ep - cp) + extlen), M_LINKER, M_WAITOK); 1195 if (result == NULL) /* actually ENOMEM */ 1196 return(NULL); 1197 for (cpp = linker_ext_list; *cpp; cpp++) { 1198 strncpy(result, cp, ep - cp); 1199 strcpy(result + (ep - cp), name); 1200 strcat(result, *cpp); 1201 1202 /* 1203 * Attempt to open the file, and return the path if we succeed 1204 * and it's a regular file. 1205 */ 1206 NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, result, p); 1207 error = vn_open(&nd, FREAD, 0); 1208 if (error == 0) { 1209 NDFREE(&nd, NDF_ONLY_PNBUF); 1210 type = nd.ni_vp->v_type; 1211 VOP_UNLOCK(nd.ni_vp, 0, p); 1212 vn_close(nd.ni_vp, FREAD, p->p_ucred, p); 1213 if (type == VREG) 1214 return(result); 1215 } 1216 } 1217 free(result, M_LINKER); 1218 1219 if (*ep == 0) 1220 break; 1221 cp = ep + 1; 1222 } 1223 return(NULL); 1224} 1225 1226static const char * 1227linker_basename(const char* path) 1228{ 1229 const char *filename; 1230 1231 filename = rindex(path, '/'); 1232 if (filename == NULL) 1233 return path; 1234 if (filename[1]) 1235 filename++; 1236 return filename; 1237} 1238 1239/* 1240 * Find a file which contains given module and load it, 1241 * if "parent" is not NULL, register a reference to it. 1242 */ 1243static int 1244linker_load_module(const char *modname, struct linker_file *parent) 1245{ 1246 linker_file_t lfdep; 1247 const char *filename; 1248 char *pathname; 1249 int error; 1250 1251 /* 1252 * There will be a system to look up or guess a file name from 1253 * a module name. 1254 * For now we just try to load a file with the same name. 1255 */ 1256 pathname = linker_search_path(modname); 1257 if (pathname == NULL) 1258 return ENOENT; 1259 1260 /* Can't load more than one file with the same basename */ 1261 filename = linker_basename(pathname); 1262 if (linker_find_file_by_name(filename)) { 1263 error = EEXIST; 1264 goto out; 1265 } 1266 1267 do { 1268 error = linker_load_file(pathname, &lfdep); 1269 if (error) 1270 break; 1271 if (parent) { 1272 error = linker_file_add_dependancy(parent, lfdep); 1273 if (error) 1274 break; 1275 } 1276 } while(0); 1277out: 1278 if (pathname) 1279 free(pathname, M_LINKER); 1280 return error; 1281} 1282 1283/* 1284 * This routine is responsible for finding dependencies of userland 1285 * initiated kldload(2)'s of files. 1286 */ 1287int 1288linker_load_dependancies(linker_file_t lf) 1289{ 1290 linker_file_t lfdep; 1291 struct linker_set *deps; 1292 struct mod_metadata *mp, *nmp; 1293 modlist_t mod; 1294 char *modname, *nmodname; 1295 int i, j, error = 0; 1296 1297 /* 1298 * All files are dependant on /kernel. 1299 */ 1300 if (linker_kernel_file) { 1301 linker_kernel_file->refs++; 1302 error = linker_file_add_dependancy(lf, linker_kernel_file); 1303 if (error) 1304 return error; 1305 } 1306 1307 deps = (struct linker_set*) 1308 linker_file_lookup_symbol(lf, MDT_SETNAME, 0); 1309 if (deps != NULL) { 1310 for (i = 0; i < deps->ls_length; i++) { 1311 mp = linker_reloc_ptr(lf, deps->ls_items[i]); 1312 if (mp->md_type != MDT_VERSION) 1313 continue; 1314 modname = linker_reloc_ptr(lf, mp->md_cval); 1315 if (modlist_lookup(modname) != NULL) { 1316 printf("module %s already present!\n", modname); 1317 return EEXIST; 1318 } 1319 } 1320 } 1321 if (deps != NULL) { 1322 for (i = 0; i < deps->ls_length; i++) { 1323 mp = linker_reloc_ptr(lf, deps->ls_items[i]); 1324 if (mp->md_type != MDT_DEPEND) 1325 continue; 1326 modname = linker_reloc_ptr(lf, mp->md_cval); 1327 nmodname = NULL; 1328 for (j = 0; j < deps->ls_length; j++) { 1329 nmp = linker_reloc_ptr(lf, deps->ls_items[j]); 1330 if (nmp->md_type != MDT_VERSION) 1331 continue; 1332 nmodname = linker_reloc_ptr(lf, nmp->md_cval); 1333 if (strcmp(modname, nmodname) == 0) 1334 break; 1335 } 1336 if (j < deps->ls_length) /* early exit, it's a self reference */ 1337 continue; 1338 mod = modlist_lookup(modname); 1339 if (mod) { /* woohoo, it's loaded already */ 1340 lfdep = mod->container; 1341 lfdep->refs++; 1342 error = linker_file_add_dependancy(lf, lfdep); 1343 if (error) 1344 break; 1345 continue; 1346 } 1347 error = linker_load_module(modname, lf); 1348 if (error) { 1349 printf("KLD %s: depends on %s - not available\n", 1350 lf->filename, modname); 1351 break; 1352 } 1353 } 1354 1355 } 1356 if (error == 0 && deps) { 1357 for (i = 0; i < deps->ls_length; i++) { 1358 mp = linker_reloc_ptr(lf, deps->ls_items[i]); 1359 if (mp->md_type != MDT_VERSION) 1360 continue; 1361 modname = linker_reloc_ptr(lf, mp->md_cval); 1362 mod = malloc(sizeof(struct modlist), M_LINKER, M_NOWAIT); 1363 if (mod == NULL) 1364 panic("no memory for module list"); 1365 bzero(mod, sizeof(*mod)); 1366 mod->container = lf; 1367 mod->name = modname; 1368 TAILQ_INSERT_TAIL(&found_modules, mod, link); 1369 } 1370 } 1371 return error; 1372} 1373