158 { 0, 0 } 159}; 160 161static struct linker_class link_elf_class = { 162#if ELF_TARG_CLASS == ELFCLASS32 163 "elf32", 164#else 165 "elf64", 166#endif 167 link_elf_methods, sizeof(struct elf_file) 168}; 169 170static int parse_dynamic(elf_file_t ef); 171static int relocate_file(elf_file_t ef); 172static int link_elf_preload_parse_symbols(elf_file_t ef); 173 174#ifdef GDB 175static void r_debug_state(struct r_debug *dummy_one, 176 struct link_map *dummy_two); 177 178/* 179 * A list of loaded modules for GDB to use for loading symbols. 180 */ 181struct r_debug r_debug; 182 183#define GDB_STATE(s) r_debug.r_state = s; r_debug_state(NULL, NULL); 184 185/* 186 * Function for the debugger to set a breakpoint on to gain control. 187 */ 188static void 189r_debug_state(struct r_debug *dummy_one __unused, 190 struct link_map *dummy_two __unused) 191{ 192} 193 194static void 195link_elf_add_gdb(struct link_map *l) 196{ 197 struct link_map *prev; 198 199 l->l_next = NULL; 200 201 if (r_debug.r_map == NULL) { 202 /* Add first. */ 203 l->l_prev = NULL; 204 r_debug.r_map = l; 205 } else { 206 /* Append to list. */ 207 for (prev = r_debug.r_map; prev->l_next != NULL; prev = prev->l_next) 208 ; 209 l->l_prev = prev; 210 prev->l_next = l; 211 } 212} 213 214static void 215link_elf_delete_gdb(struct link_map *l) 216{ 217 if (l->l_prev == NULL) { 218 /* Remove first. */ 219 if ((r_debug.r_map = l->l_next) != NULL) 220 l->l_next->l_prev = NULL; 221 } else { 222 /* Remove any but first. */ 223 if ((l->l_prev->l_next = l->l_next) != NULL) 224 l->l_next->l_prev = l->l_prev; 225 } 226} 227#endif /* GDB */ 228 229#ifdef __ia64__ 230Elf_Addr link_elf_get_gp(linker_file_t); 231#endif 232 233/* 234 * The kernel symbol table starts here. 235 */ 236extern struct _dynamic _DYNAMIC; 237 238static void 239link_elf_error(const char *filename, const char *s) 240{ 241 if (filename == NULL) 242 printf("kldload: %s\n", s); 243 else 244 printf("kldload: %s: %s\n", filename, s); 245} 246 247/* 248 * Actions performed after linking/loading both the preloaded kernel and any 249 * modules; whether preloaded or dynamicly loaded. 250 */ 251static int 252link_elf_link_common_finish(linker_file_t lf) 253{ 254#ifdef GDB 255 elf_file_t ef = (elf_file_t)lf; 256 char *newfilename; 257#endif 258 int error; 259 260 /* Notify MD code that a module is being loaded. */ 261 error = elf_cpu_load_file(lf); 262 if (error) 263 return (error); 264 265#ifdef GDB 266 GDB_STATE(RT_ADD); 267 ef->gdb.l_addr = lf->address; 268 newfilename = malloc(strlen(lf->filename) + 1, M_LINKER, M_WAITOK); 269 strcpy(newfilename, lf->filename); 270 ef->gdb.l_name = newfilename; 271 ef->gdb.l_ld = ef->dynamic; 272 link_elf_add_gdb(&ef->gdb); 273 GDB_STATE(RT_CONSISTENT); 274#endif 275 276 return (0); 277} 278 279static void 280link_elf_init(void* arg) 281{ 282 Elf_Dyn *dp; 283 caddr_t modptr, baseptr, sizeptr; 284 elf_file_t ef; 285 char *modname; 286 287 linker_add_class(&link_elf_class); 288 289 dp = (Elf_Dyn*) &_DYNAMIC; 290 modname = NULL; 291 modptr = preload_search_by_type("elf" __XSTRING(__ELF_WORD_SIZE) " kernel"); 292 if (modptr == NULL) 293 modptr = preload_search_by_type("elf kernel"); 294 if (modptr) 295 modname = (char *)preload_search_info(modptr, MODINFO_NAME); 296 if (modname == NULL) 297 modname = "kernel"; 298 linker_kernel_file = linker_make_file(modname, &link_elf_class); 299 if (linker_kernel_file == NULL) 300 panic("link_elf_init: Can't create linker structures for kernel"); 301 302 ef = (elf_file_t) linker_kernel_file; 303 ef->preloaded = 1; 304 ef->address = 0; 305#ifdef SPARSE_MAPPING 306 ef->object = 0; 307#endif 308 ef->dynamic = dp; 309 310 if (dp) 311 parse_dynamic(ef); 312 linker_kernel_file->address = (caddr_t) KERNBASE; 313 linker_kernel_file->size = -(intptr_t)linker_kernel_file->address; 314 315 if (modptr) { 316 ef->modptr = modptr; 317 baseptr = preload_search_info(modptr, MODINFO_ADDR); 318 if (baseptr) 319 linker_kernel_file->address = *(caddr_t *)baseptr; 320 sizeptr = preload_search_info(modptr, MODINFO_SIZE); 321 if (sizeptr) 322 linker_kernel_file->size = *(size_t *)sizeptr; 323 } 324 (void)link_elf_preload_parse_symbols(ef); 325 326#ifdef GDB 327 r_debug.r_map = NULL; 328 r_debug.r_brk = r_debug_state; 329 r_debug.r_state = RT_CONSISTENT; 330#endif 331 332 (void)link_elf_link_common_finish(linker_kernel_file); 333 linker_kernel_file->flags |= LINKER_FILE_LINKED; 334} 335 336SYSINIT(link_elf, SI_SUB_KLD, SI_ORDER_THIRD, link_elf_init, 0); 337 338static int 339link_elf_preload_parse_symbols(elf_file_t ef) 340{ 341 caddr_t pointer; 342 caddr_t ssym, esym, base; 343 caddr_t strtab; 344 int strcnt; 345 Elf_Sym* symtab; 346 int symcnt; 347 348 if (ef->modptr == NULL) 349 return 0; 350 pointer = preload_search_info(ef->modptr, MODINFO_METADATA|MODINFOMD_SSYM); 351 if (pointer == NULL) 352 return 0; 353 ssym = *(caddr_t *)pointer; 354 pointer = preload_search_info(ef->modptr, MODINFO_METADATA|MODINFOMD_ESYM); 355 if (pointer == NULL) 356 return 0; 357 esym = *(caddr_t *)pointer; 358 359 base = ssym; 360 361 symcnt = *(long *)base; 362 base += sizeof(long); 363 symtab = (Elf_Sym *)base; 364 base += roundup(symcnt, sizeof(long)); 365 366 if (base > esym || base < ssym) { 367 printf("Symbols are corrupt!\n"); 368 return EINVAL; 369 } 370 371 strcnt = *(long *)base; 372 base += sizeof(long); 373 strtab = base; 374 base += roundup(strcnt, sizeof(long)); 375 376 if (base > esym || base < ssym) { 377 printf("Symbols are corrupt!\n"); 378 return EINVAL; 379 } 380 381 ef->ddbsymtab = symtab; 382 ef->ddbsymcnt = symcnt / sizeof(Elf_Sym); 383 ef->ddbstrtab = strtab; 384 ef->ddbstrcnt = strcnt; 385 386 return 0; 387} 388 389static int 390parse_dynamic(elf_file_t ef) 391{ 392 Elf_Dyn *dp; 393 int plttype = DT_REL; 394 395 for (dp = ef->dynamic; dp->d_tag != DT_NULL; dp++) { 396 switch (dp->d_tag) { 397 case DT_HASH: 398 { 399 /* From src/libexec/rtld-elf/rtld.c */ 400 const Elf_Hashelt *hashtab = (const Elf_Hashelt *) 401 (ef->address + dp->d_un.d_ptr); 402 ef->nbuckets = hashtab[0]; 403 ef->nchains = hashtab[1]; 404 ef->buckets = hashtab + 2; 405 ef->chains = ef->buckets + ef->nbuckets; 406 break; 407 } 408 case DT_STRTAB: 409 ef->strtab = (caddr_t) (ef->address + dp->d_un.d_ptr); 410 break; 411 case DT_STRSZ: 412 ef->strsz = dp->d_un.d_val; 413 break; 414 case DT_SYMTAB: 415 ef->symtab = (Elf_Sym*) (ef->address + dp->d_un.d_ptr); 416 break; 417 case DT_SYMENT: 418 if (dp->d_un.d_val != sizeof(Elf_Sym)) 419 return ENOEXEC; 420 break; 421 case DT_PLTGOT: 422 ef->got = (Elf_Addr *) (ef->address + dp->d_un.d_ptr); 423 break; 424 case DT_REL: 425 ef->rel = (const Elf_Rel *) (ef->address + dp->d_un.d_ptr); 426 break; 427 case DT_RELSZ: 428 ef->relsize = dp->d_un.d_val; 429 break; 430 case DT_RELENT: 431 if (dp->d_un.d_val != sizeof(Elf_Rel)) 432 return ENOEXEC; 433 break; 434 case DT_JMPREL: 435 ef->pltrel = (const Elf_Rel *) (ef->address + dp->d_un.d_ptr); 436 break; 437 case DT_PLTRELSZ: 438 ef->pltrelsize = dp->d_un.d_val; 439 break; 440 case DT_RELA: 441 ef->rela = (const Elf_Rela *) (ef->address + dp->d_un.d_ptr); 442 break; 443 case DT_RELASZ: 444 ef->relasize = dp->d_un.d_val; 445 break; 446 case DT_RELAENT: 447 if (dp->d_un.d_val != sizeof(Elf_Rela)) 448 return ENOEXEC; 449 break; 450 case DT_PLTREL: 451 plttype = dp->d_un.d_val; 452 if (plttype != DT_REL && plttype != DT_RELA) 453 return ENOEXEC; 454 break; 455#ifdef GDB 456 case DT_DEBUG: 457 dp->d_un.d_ptr = (Elf_Addr) &r_debug; 458 break; 459#endif 460 } 461 } 462 463 if (plttype == DT_RELA) { 464 ef->pltrela = (const Elf_Rela *) ef->pltrel; 465 ef->pltrel = NULL; 466 ef->pltrelasize = ef->pltrelsize; 467 ef->pltrelsize = 0; 468 } 469 470 ef->ddbsymtab = ef->symtab; 471 ef->ddbsymcnt = ef->nchains; 472 ef->ddbstrtab = ef->strtab; 473 ef->ddbstrcnt = ef->strsz; 474 475 return 0; 476} 477 478static int 479link_elf_link_preload(linker_class_t cls, 480 const char* filename, linker_file_t *result) 481{ 482 caddr_t modptr, baseptr, sizeptr, dynptr; 483 char *type; 484 elf_file_t ef; 485 linker_file_t lf; 486 int error; 487 vm_offset_t dp; 488 489 /* Look to see if we have the file preloaded */ 490 modptr = preload_search_by_name(filename); 491 if (modptr == NULL) 492 return ENOENT; 493 494 type = (char *)preload_search_info(modptr, MODINFO_TYPE); 495 baseptr = preload_search_info(modptr, MODINFO_ADDR); 496 sizeptr = preload_search_info(modptr, MODINFO_SIZE); 497 dynptr = preload_search_info(modptr, MODINFO_METADATA|MODINFOMD_DYNAMIC); 498 if (type == NULL || 499 (strcmp(type, "elf" __XSTRING(__ELF_WORD_SIZE) " module") != 0 && 500 strcmp(type, "elf module") != 0)) 501 return (EFTYPE); 502 if (baseptr == NULL || sizeptr == NULL || dynptr == NULL) 503 return (EINVAL); 504 505 lf = linker_make_file(filename, &link_elf_class); 506 if (lf == NULL) { 507 return ENOMEM; 508 } 509 510 ef = (elf_file_t) lf; 511 ef->preloaded = 1; 512 ef->modptr = modptr; 513 ef->address = *(caddr_t *)baseptr; 514#ifdef SPARSE_MAPPING 515 ef->object = 0; 516#endif 517 dp = (vm_offset_t)ef->address + *(vm_offset_t *)dynptr; 518 ef->dynamic = (Elf_Dyn *)dp; 519 lf->address = ef->address; 520 lf->size = *(size_t *)sizeptr; 521 522 error = parse_dynamic(ef); 523 if (error) { 524 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 525 return error; 526 } 527 link_elf_reloc_local(lf); 528 *result = lf; 529 return (0); 530} 531 532static int 533link_elf_link_preload_finish(linker_file_t lf) 534{ 535 elf_file_t ef; 536 int error; 537 538 ef = (elf_file_t) lf; 539#if 0 /* this will be more trouble than it's worth for now */ 540 for (dp = ef->dynamic; dp->d_tag != DT_NULL; dp++) { 541 if (dp->d_tag != DT_NEEDED) 542 continue; 543 modname = ef->strtab + dp->d_un.d_val; 544 error = linker_load_module(modname, lf); 545 if (error) 546 goto out; 547 } 548#endif 549 error = relocate_file(ef); 550 if (error) 551 return error; 552 (void)link_elf_preload_parse_symbols(ef); 553 554 return (link_elf_link_common_finish(lf)); 555} 556 557static int 558link_elf_load_file(linker_class_t cls, const char* filename, 559 linker_file_t* result) 560{ 561 struct nameidata nd; 562 struct thread* td = curthread; /* XXX */ 563 Elf_Ehdr *hdr; 564 caddr_t firstpage; 565 int nbytes, i; 566 Elf_Phdr *phdr; 567 Elf_Phdr *phlimit; 568 Elf_Phdr *segs[MAXSEGS]; 569 int nsegs; 570 Elf_Phdr *phdyn; 571 Elf_Phdr *phphdr; 572 caddr_t mapbase; 573 size_t mapsize; 574 Elf_Off base_offset; 575 Elf_Addr base_vaddr; 576 Elf_Addr base_vlimit; 577 int error = 0; 578 int resid, flags; 579 elf_file_t ef; 580 linker_file_t lf; 581 Elf_Shdr *shdr; 582 int symtabindex; 583 int symstrindex; 584 int symcnt; 585 int strcnt; 586 int vfslocked; 587 588 shdr = NULL; 589 lf = NULL; 590 591 NDINIT(&nd, LOOKUP, FOLLOW | MPSAFE, UIO_SYSSPACE, filename, td); 592 flags = FREAD; 593 error = vn_open(&nd, &flags, 0, NULL); 594 if (error) 595 return error; 596 vfslocked = NDHASGIANT(&nd); 597 NDFREE(&nd, NDF_ONLY_PNBUF); 598 if (nd.ni_vp->v_type != VREG) { 599 error = ENOEXEC; 600 firstpage = NULL; 601 goto out; 602 } 603#ifdef MAC 604 error = mac_kld_check_load(curthread->td_ucred, nd.ni_vp); 605 if (error) { 606 firstpage = NULL; 607 goto out; 608 } 609#endif 610 611 /* 612 * Read the elf header from the file. 613 */ 614 firstpage = malloc(PAGE_SIZE, M_LINKER, M_WAITOK); 615 if (firstpage == NULL) { 616 error = ENOMEM; 617 goto out; 618 } 619 hdr = (Elf_Ehdr *)firstpage; 620 error = vn_rdwr(UIO_READ, nd.ni_vp, firstpage, PAGE_SIZE, 0, 621 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 622 &resid, td); 623 nbytes = PAGE_SIZE - resid; 624 if (error) 625 goto out; 626 627 if (!IS_ELF(*hdr)) { 628 error = ENOEXEC; 629 goto out; 630 } 631 632 if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS 633 || hdr->e_ident[EI_DATA] != ELF_TARG_DATA) { 634 link_elf_error(filename, "Unsupported file layout"); 635 error = ENOEXEC; 636 goto out; 637 } 638 if (hdr->e_ident[EI_VERSION] != EV_CURRENT 639 || hdr->e_version != EV_CURRENT) { 640 link_elf_error(filename, "Unsupported file version"); 641 error = ENOEXEC; 642 goto out; 643 } 644 if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN) { 645 error = ENOSYS; 646 goto out; 647 } 648 if (hdr->e_machine != ELF_TARG_MACH) { 649 link_elf_error(filename, "Unsupported machine"); 650 error = ENOEXEC; 651 goto out; 652 } 653 654 /* 655 * We rely on the program header being in the first page. This is 656 * not strictly required by the ABI specification, but it seems to 657 * always true in practice. And, it simplifies things considerably. 658 */ 659 if (!((hdr->e_phentsize == sizeof(Elf_Phdr)) && 660 (hdr->e_phoff + hdr->e_phnum*sizeof(Elf_Phdr) <= PAGE_SIZE) && 661 (hdr->e_phoff + hdr->e_phnum*sizeof(Elf_Phdr) <= nbytes))) 662 link_elf_error(filename, "Unreadable program headers"); 663 664 /* 665 * Scan the program header entries, and save key information. 666 * 667 * We rely on there being exactly two load segments, text and data, 668 * in that order. 669 */ 670 phdr = (Elf_Phdr *) (firstpage + hdr->e_phoff); 671 phlimit = phdr + hdr->e_phnum; 672 nsegs = 0; 673 phdyn = NULL; 674 phphdr = NULL; 675 while (phdr < phlimit) { 676 switch (phdr->p_type) { 677 678 case PT_LOAD: 679 if (nsegs == MAXSEGS) { 680 link_elf_error(filename, "Too many sections"); 681 error = ENOEXEC; 682 goto out; 683 } 684 /* 685 * XXX: We just trust they come in right order ?? 686 */ 687 segs[nsegs] = phdr; 688 ++nsegs; 689 break; 690 691 case PT_PHDR: 692 phphdr = phdr; 693 break; 694 695 case PT_DYNAMIC: 696 phdyn = phdr; 697 break; 698 699 case PT_INTERP: 700 error = ENOSYS; 701 goto out; 702 } 703 704 ++phdr; 705 } 706 if (phdyn == NULL) { 707 link_elf_error(filename, "Object is not dynamically-linked"); 708 error = ENOEXEC; 709 goto out; 710 } 711 if (nsegs == 0) { 712 link_elf_error(filename, "No sections"); 713 error = ENOEXEC; 714 goto out; 715 } 716 717 /* 718 * Allocate the entire address space of the object, to stake out our 719 * contiguous region, and to establish the base address for relocation. 720 */ 721 base_offset = trunc_page(segs[0]->p_offset); 722 base_vaddr = trunc_page(segs[0]->p_vaddr); 723 base_vlimit = round_page(segs[nsegs - 1]->p_vaddr + 724 segs[nsegs - 1]->p_memsz); 725 mapsize = base_vlimit - base_vaddr; 726 727 lf = linker_make_file(filename, &link_elf_class); 728 if (!lf) { 729 error = ENOMEM; 730 goto out; 731 } 732 733 ef = (elf_file_t) lf; 734#ifdef SPARSE_MAPPING 735 ef->object = vm_object_allocate(OBJT_DEFAULT, mapsize >> PAGE_SHIFT); 736 if (ef->object == NULL) { 737 error = ENOMEM; 738 goto out; 739 } 740 ef->address = (caddr_t) vm_map_min(kernel_map); 741 error = vm_map_find(kernel_map, ef->object, 0, 742 (vm_offset_t *) &ef->address, 743 mapsize, 1, 744 VM_PROT_ALL, VM_PROT_ALL, 0); 745 if (error) { 746 vm_object_deallocate(ef->object); 747 ef->object = 0; 748 goto out; 749 } 750#else 751 ef->address = malloc(mapsize, M_LINKER, M_WAITOK); 752 if (!ef->address) { 753 error = ENOMEM; 754 goto out; 755 } 756#endif 757 mapbase = ef->address; 758 759 /* 760 * Read the text and data sections and zero the bss. 761 */ 762 for (i = 0; i < nsegs; i++) { 763 caddr_t segbase = mapbase + segs[i]->p_vaddr - base_vaddr; 764 error = vn_rdwr(UIO_READ, nd.ni_vp, 765 segbase, segs[i]->p_filesz, segs[i]->p_offset, 766 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 767 &resid, td); 768 if (error) { 769 goto out; 770 } 771 bzero(segbase + segs[i]->p_filesz, 772 segs[i]->p_memsz - segs[i]->p_filesz); 773 774#ifdef SPARSE_MAPPING 775 /* 776 * Wire down the pages 777 */ 778 error = vm_map_wire(kernel_map, 779 (vm_offset_t) segbase, 780 (vm_offset_t) segbase + segs[i]->p_memsz, 781 VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES); 782 if (error != KERN_SUCCESS) { 783 error = ENOMEM; 784 goto out; 785 } 786#endif 787 } 788 789#ifdef GPROF 790 /* Update profiling information with the new text segment. */ 791 mtx_lock(&Giant); 792 kmupetext((uintfptr_t)(mapbase + segs[0]->p_vaddr - base_vaddr + 793 segs[0]->p_memsz)); 794 mtx_unlock(&Giant); 795#endif 796 797 ef->dynamic = (Elf_Dyn *) (mapbase + phdyn->p_vaddr - base_vaddr); 798 799 lf->address = ef->address; 800 lf->size = mapsize; 801 802 error = parse_dynamic(ef); 803 if (error) 804 goto out; 805 link_elf_reloc_local(lf); 806 807 VOP_UNLOCK(nd.ni_vp, 0); 808 error = linker_load_dependencies(lf); 809 vn_lock(nd.ni_vp, LK_EXCLUSIVE | LK_RETRY); 810 if (error) 811 goto out; 812#if 0 /* this will be more trouble than it's worth for now */ 813 for (dp = ef->dynamic; dp->d_tag != DT_NULL; dp++) { 814 if (dp->d_tag != DT_NEEDED) 815 continue; 816 modname = ef->strtab + dp->d_un.d_val; 817 error = linker_load_module(modname, lf); 818 if (error) 819 goto out; 820 } 821#endif 822 error = relocate_file(ef); 823 if (error) 824 goto out; 825 826 /* Try and load the symbol table if it's present. (you can strip it!) */ 827 nbytes = hdr->e_shnum * hdr->e_shentsize; 828 if (nbytes == 0 || hdr->e_shoff == 0) 829 goto nosyms; 830 shdr = malloc(nbytes, M_LINKER, M_WAITOK | M_ZERO); 831 if (shdr == NULL) { 832 error = ENOMEM; 833 goto out; 834 } 835 error = vn_rdwr(UIO_READ, nd.ni_vp, 836 (caddr_t)shdr, nbytes, hdr->e_shoff, 837 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 838 &resid, td); 839 if (error) 840 goto out; 841 symtabindex = -1; 842 symstrindex = -1; 843 for (i = 0; i < hdr->e_shnum; i++) { 844 if (shdr[i].sh_type == SHT_SYMTAB) { 845 symtabindex = i; 846 symstrindex = shdr[i].sh_link; 847 } 848 } 849 if (symtabindex < 0 || symstrindex < 0) 850 goto nosyms; 851 852 symcnt = shdr[symtabindex].sh_size; 853 ef->symbase = malloc(symcnt, M_LINKER, M_WAITOK); 854 strcnt = shdr[symstrindex].sh_size; 855 ef->strbase = malloc(strcnt, M_LINKER, M_WAITOK); 856 857 if (ef->symbase == NULL || ef->strbase == NULL) { 858 error = ENOMEM; 859 goto out; 860 } 861 error = vn_rdwr(UIO_READ, nd.ni_vp, 862 ef->symbase, symcnt, shdr[symtabindex].sh_offset, 863 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 864 &resid, td); 865 if (error) 866 goto out; 867 error = vn_rdwr(UIO_READ, nd.ni_vp, 868 ef->strbase, strcnt, shdr[symstrindex].sh_offset, 869 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 870 &resid, td); 871 if (error) 872 goto out; 873 874 ef->ddbsymcnt = symcnt / sizeof(Elf_Sym); 875 ef->ddbsymtab = (const Elf_Sym *)ef->symbase; 876 ef->ddbstrcnt = strcnt; 877 ef->ddbstrtab = ef->strbase; 878 879 error = link_elf_link_common_finish(lf); 880 if (error) 881 goto out; 882 883nosyms: 884 885 *result = lf; 886 887out: 888 if (error && lf) 889 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 890 if (shdr) 891 free(shdr, M_LINKER); 892 if (firstpage) 893 free(firstpage, M_LINKER); 894 VOP_UNLOCK(nd.ni_vp, 0); 895 vn_close(nd.ni_vp, FREAD, td->td_ucred, td); 896 VFS_UNLOCK_GIANT(vfslocked); 897 898 return error; 899} 900 901static void 902link_elf_unload_file(linker_file_t file) 903{ 904 elf_file_t ef = (elf_file_t) file; 905 906#ifdef GDB 907 if (ef->gdb.l_ld) { 908 GDB_STATE(RT_DELETE); 909 free((void *)(uintptr_t)ef->gdb.l_name, M_LINKER); 910 link_elf_delete_gdb(&ef->gdb); 911 GDB_STATE(RT_CONSISTENT); 912 } 913#endif 914 915 /* Notify MD code that a module is being unloaded. */ 916 elf_cpu_unload_file(file); 917 918 if (ef->preloaded) { 919 link_elf_unload_preload(file); 920 return; 921 } 922 923#ifdef SPARSE_MAPPING 924 if (ef->object) { 925 vm_map_remove(kernel_map, (vm_offset_t) ef->address, 926 (vm_offset_t) ef->address 927 + (ef->object->size << PAGE_SHIFT)); 928 } 929#else 930 if (ef->address) 931 free(ef->address, M_LINKER); 932#endif 933 if (ef->symbase) 934 free(ef->symbase, M_LINKER); 935 if (ef->strbase) 936 free(ef->strbase, M_LINKER); 937 if (ef->ctftab) 938 free(ef->ctftab, M_LINKER); 939 if (ef->ctfoff) 940 free(ef->ctfoff, M_LINKER); 941 if (ef->typoff) 942 free(ef->typoff, M_LINKER); 943} 944 945static void 946link_elf_unload_preload(linker_file_t file) 947{ 948 if (file->filename) 949 preload_delete_name(file->filename); 950} 951 952static const char * 953symbol_name(elf_file_t ef, Elf_Size r_info) 954{ 955 const Elf_Sym *ref; 956 957 if (ELF_R_SYM(r_info)) { 958 ref = ef->symtab + ELF_R_SYM(r_info); 959 return ef->strtab + ref->st_name; 960 } else 961 return NULL; 962} 963 964static int 965relocate_file(elf_file_t ef) 966{ 967 const Elf_Rel *rellim; 968 const Elf_Rel *rel; 969 const Elf_Rela *relalim; 970 const Elf_Rela *rela; 971 const char *symname; 972 973 /* Perform relocations without addend if there are any: */ 974 rel = ef->rel; 975 if (rel) { 976 rellim = (const Elf_Rel *)((const char *)ef->rel + ef->relsize); 977 while (rel < rellim) { 978 if (elf_reloc(&ef->lf, (Elf_Addr)ef->address, rel, ELF_RELOC_REL, 979 elf_lookup)) { 980 symname = symbol_name(ef, rel->r_info); 981 printf("link_elf: symbol %s undefined\n", symname); 982 return ENOENT; 983 } 984 rel++; 985 } 986 } 987 988 /* Perform relocations with addend if there are any: */ 989 rela = ef->rela; 990 if (rela) { 991 relalim = (const Elf_Rela *)((const char *)ef->rela + ef->relasize); 992 while (rela < relalim) { 993 if (elf_reloc(&ef->lf, (Elf_Addr)ef->address, rela, ELF_RELOC_RELA, 994 elf_lookup)) { 995 symname = symbol_name(ef, rela->r_info); 996 printf("link_elf: symbol %s undefined\n", symname); 997 return ENOENT; 998 } 999 rela++; 1000 } 1001 } 1002 1003 /* Perform PLT relocations without addend if there are any: */ 1004 rel = ef->pltrel; 1005 if (rel) { 1006 rellim = (const Elf_Rel *)((const char *)ef->pltrel + ef->pltrelsize); 1007 while (rel < rellim) { 1008 if (elf_reloc(&ef->lf, (Elf_Addr)ef->address, rel, ELF_RELOC_REL, 1009 elf_lookup)) { 1010 symname = symbol_name(ef, rel->r_info); 1011 printf("link_elf: symbol %s undefined\n", symname); 1012 return ENOENT; 1013 } 1014 rel++; 1015 } 1016 } 1017 1018 /* Perform relocations with addend if there are any: */ 1019 rela = ef->pltrela; 1020 if (rela) { 1021 relalim = (const Elf_Rela *)((const char *)ef->pltrela + ef->pltrelasize); 1022 while (rela < relalim) { 1023 if (elf_reloc(&ef->lf, (Elf_Addr)ef->address, rela, ELF_RELOC_RELA, 1024 elf_lookup)) { 1025 symname = symbol_name(ef, rela->r_info); 1026 printf("link_elf: symbol %s undefined\n", symname); 1027 return ENOENT; 1028 } 1029 rela++; 1030 } 1031 } 1032 1033 return 0; 1034} 1035 1036/* 1037 * Hash function for symbol table lookup. Don't even think about changing 1038 * this. It is specified by the System V ABI. 1039 */ 1040static unsigned long 1041elf_hash(const char *name) 1042{ 1043 const unsigned char *p = (const unsigned char *) name; 1044 unsigned long h = 0; 1045 unsigned long g; 1046 1047 while (*p != '\0') { 1048 h = (h << 4) + *p++; 1049 if ((g = h & 0xf0000000) != 0) 1050 h ^= g >> 24; 1051 h &= ~g; 1052 } 1053 return h; 1054} 1055 1056static int 1057link_elf_lookup_symbol(linker_file_t lf, const char* name, c_linker_sym_t* sym) 1058{ 1059 elf_file_t ef = (elf_file_t) lf; 1060 unsigned long symnum; 1061 const Elf_Sym* symp; 1062 const char *strp; 1063 unsigned long hash; 1064 int i; 1065 1066 /* If we don't have a hash, bail. */ 1067 if (ef->buckets == NULL || ef->nbuckets == 0) { 1068 printf("link_elf_lookup_symbol: missing symbol hash table\n"); 1069 return ENOENT; 1070 } 1071 1072 /* First, search hashed global symbols */ 1073 hash = elf_hash(name); 1074 symnum = ef->buckets[hash % ef->nbuckets]; 1075 1076 while (symnum != STN_UNDEF) { 1077 if (symnum >= ef->nchains) { 1078 printf("link_elf_lookup_symbol: corrupt symbol table\n"); 1079 return ENOENT; 1080 } 1081 1082 symp = ef->symtab + symnum; 1083 if (symp->st_name == 0) { 1084 printf("link_elf_lookup_symbol: corrupt symbol table\n"); 1085 return ENOENT; 1086 } 1087 1088 strp = ef->strtab + symp->st_name; 1089 1090 if (strcmp(name, strp) == 0) { 1091 if (symp->st_shndx != SHN_UNDEF || 1092 (symp->st_value != 0 && 1093 ELF_ST_TYPE(symp->st_info) == STT_FUNC)) { 1094 *sym = (c_linker_sym_t) symp; 1095 return 0; 1096 } else 1097 return ENOENT; 1098 } 1099 1100 symnum = ef->chains[symnum]; 1101 } 1102 1103 /* If we have not found it, look at the full table (if loaded) */ 1104 if (ef->symtab == ef->ddbsymtab) 1105 return ENOENT; 1106 1107 /* Exhaustive search */ 1108 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) { 1109 strp = ef->ddbstrtab + symp->st_name; 1110 if (strcmp(name, strp) == 0) { 1111 if (symp->st_shndx != SHN_UNDEF || 1112 (symp->st_value != 0 && 1113 ELF_ST_TYPE(symp->st_info) == STT_FUNC)) { 1114 *sym = (c_linker_sym_t) symp; 1115 return 0; 1116 } else 1117 return ENOENT; 1118 } 1119 } 1120 1121 return ENOENT; 1122} 1123 1124static int 1125link_elf_symbol_values(linker_file_t lf, c_linker_sym_t sym, linker_symval_t* symval) 1126{ 1127 elf_file_t ef = (elf_file_t) lf; 1128 const Elf_Sym* es = (const Elf_Sym*) sym; 1129 1130 if (es >= ef->symtab && es < (ef->symtab + ef->nchains)) { 1131 symval->name = ef->strtab + es->st_name; 1132 symval->value = (caddr_t) ef->address + es->st_value; 1133 symval->size = es->st_size; 1134 return 0; 1135 } 1136 if (ef->symtab == ef->ddbsymtab) 1137 return ENOENT; 1138 if (es >= ef->ddbsymtab && es < (ef->ddbsymtab + ef->ddbsymcnt)) { 1139 symval->name = ef->ddbstrtab + es->st_name; 1140 symval->value = (caddr_t) ef->address + es->st_value; 1141 symval->size = es->st_size; 1142 return 0; 1143 } 1144 return ENOENT; 1145} 1146 1147static int 1148link_elf_search_symbol(linker_file_t lf, caddr_t value, 1149 c_linker_sym_t* sym, long* diffp) 1150{ 1151 elf_file_t ef = (elf_file_t) lf; 1152 u_long off = (uintptr_t) (void *) value; 1153 u_long diff = off; 1154 u_long st_value; 1155 const Elf_Sym* es; 1156 const Elf_Sym* best = 0; 1157 int i; 1158 1159 for (i = 0, es = ef->ddbsymtab; i < ef->ddbsymcnt; i++, es++) { 1160 if (es->st_name == 0) 1161 continue; 1162 st_value = es->st_value + (uintptr_t) (void *) ef->address; 1163 if (off >= st_value) { 1164 if (off - st_value < diff) { 1165 diff = off - st_value; 1166 best = es; 1167 if (diff == 0) 1168 break; 1169 } else if (off - st_value == diff) { 1170 best = es; 1171 } 1172 } 1173 } 1174 if (best == 0) 1175 *diffp = off; 1176 else 1177 *diffp = diff; 1178 *sym = (c_linker_sym_t) best; 1179 1180 return 0; 1181} 1182 1183/* 1184 * Look up a linker set on an ELF system. 1185 */ 1186static int 1187link_elf_lookup_set(linker_file_t lf, const char *name, 1188 void ***startp, void ***stopp, int *countp) 1189{ 1190 c_linker_sym_t sym; 1191 linker_symval_t symval; 1192 char *setsym; 1193 void **start, **stop; 1194 int len, error = 0, count; 1195 1196 len = strlen(name) + sizeof("__start_set_"); /* sizeof includes \0 */ 1197 setsym = malloc(len, M_LINKER, M_WAITOK); 1198 if (setsym == NULL) 1199 return ENOMEM; 1200 1201 /* get address of first entry */ 1202 snprintf(setsym, len, "%s%s", "__start_set_", name); 1203 error = link_elf_lookup_symbol(lf, setsym, &sym); 1204 if (error) 1205 goto out; 1206 link_elf_symbol_values(lf, sym, &symval); 1207 if (symval.value == 0) { 1208 error = ESRCH; 1209 goto out; 1210 } 1211 start = (void **)symval.value; 1212 1213 /* get address of last entry */ 1214 snprintf(setsym, len, "%s%s", "__stop_set_", name); 1215 error = link_elf_lookup_symbol(lf, setsym, &sym); 1216 if (error) 1217 goto out; 1218 link_elf_symbol_values(lf, sym, &symval); 1219 if (symval.value == 0) { 1220 error = ESRCH; 1221 goto out; 1222 } 1223 stop = (void **)symval.value; 1224 1225 /* and the number of entries */ 1226 count = stop - start; 1227 1228 /* and copy out */ 1229 if (startp) 1230 *startp = start; 1231 if (stopp) 1232 *stopp = stop; 1233 if (countp) 1234 *countp = count; 1235 1236out: 1237 free(setsym, M_LINKER); 1238 return error; 1239} 1240 1241static int 1242link_elf_each_function_name(linker_file_t file, 1243 int (*callback)(const char *, void *), void *opaque) { 1244 elf_file_t ef = (elf_file_t)file; 1245 const Elf_Sym* symp; 1246 int i, error; 1247 1248 /* Exhaustive search */ 1249 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) { 1250 if (symp->st_value != 0 && 1251 ELF_ST_TYPE(symp->st_info) == STT_FUNC) { 1252 error = callback(ef->ddbstrtab + symp->st_name, opaque); 1253 if (error) 1254 return (error); 1255 } 1256 } 1257 return (0); 1258} 1259 1260static int 1261link_elf_each_function_nameval(linker_file_t file, 1262 linker_function_nameval_callback_t callback, void *opaque) 1263{ 1264 linker_symval_t symval; 1265 elf_file_t ef = (elf_file_t)file; 1266 const Elf_Sym* symp; 1267 int i, error; 1268 1269 /* Exhaustive search */ 1270 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) { 1271 if (symp->st_value != 0 && 1272 ELF_ST_TYPE(symp->st_info) == STT_FUNC) { 1273 error = link_elf_symbol_values(file, (c_linker_sym_t) symp, &symval); 1274 if (error) 1275 return (error); 1276 error = callback(file, i, &symval, opaque); 1277 if (error) 1278 return (error); 1279 } 1280 } 1281 return (0); 1282} 1283 1284#ifdef __ia64__ 1285/* 1286 * Each KLD has its own GP. The GP value for each load module is given by 1287 * DT_PLTGOT on ia64. We need GP to construct function descriptors, but 1288 * don't have direct access to the ELF file structure. The link_elf_get_gp() 1289 * function returns the GP given a pointer to a generic linker file struct. 1290 */ 1291Elf_Addr 1292link_elf_get_gp(linker_file_t lf) 1293{ 1294 elf_file_t ef = (elf_file_t)lf; 1295 return (Elf_Addr)ef->got; 1296} 1297#endif 1298 1299const Elf_Sym * 1300elf_get_sym(linker_file_t lf, Elf_Size symidx) 1301{ 1302 elf_file_t ef = (elf_file_t)lf; 1303 1304 if (symidx >= ef->nchains) 1305 return (NULL); 1306 return (ef->symtab + symidx); 1307} 1308 1309const char * 1310elf_get_symname(linker_file_t lf, Elf_Size symidx) 1311{ 1312 elf_file_t ef = (elf_file_t)lf; 1313 const Elf_Sym *sym; 1314 1315 if (symidx >= ef->nchains) 1316 return (NULL); 1317 sym = ef->symtab + symidx; 1318 return (ef->strtab + sym->st_name); 1319} 1320 1321/* 1322 * Symbol lookup function that can be used when the symbol index is known (ie 1323 * in relocations). It uses the symbol index instead of doing a fully fledged 1324 * hash table based lookup when such is valid. For example for local symbols. 1325 * This is not only more efficient, it's also more correct. It's not always 1326 * the case that the symbol can be found through the hash table. 1327 */ 1328static Elf_Addr 1329elf_lookup(linker_file_t lf, Elf_Size symidx, int deps) 1330{ 1331 elf_file_t ef = (elf_file_t)lf; 1332 const Elf_Sym *sym; 1333 const char *symbol; 1334 1335 /* Don't even try to lookup the symbol if the index is bogus. */ 1336 if (symidx >= ef->nchains) 1337 return (0); 1338 1339 sym = ef->symtab + symidx; 1340 1341 /* 1342 * Don't do a full lookup when the symbol is local. It may even 1343 * fail because it may not be found through the hash table. 1344 */ 1345 if (ELF_ST_BIND(sym->st_info) == STB_LOCAL) { 1346 /* Force lookup failure when we have an insanity. */ 1347 if (sym->st_shndx == SHN_UNDEF || sym->st_value == 0) 1348 return (0); 1349 return ((Elf_Addr)ef->address + sym->st_value); 1350 } 1351 1352 /* 1353 * XXX we can avoid doing a hash table based lookup for global 1354 * symbols as well. This however is not always valid, so we'll 1355 * just do it the hard way for now. Performance tweaks can 1356 * always be added. 1357 */ 1358 1359 symbol = ef->strtab + sym->st_name; 1360 1361 /* Force a lookup failure if the symbol name is bogus. */ 1362 if (*symbol == 0) 1363 return (0); 1364 1365 return ((Elf_Addr)linker_file_lookup_symbol(lf, symbol, deps)); 1366} 1367 1368static void 1369link_elf_reloc_local(linker_file_t lf) 1370{ 1371 const Elf_Rel *rellim; 1372 const Elf_Rel *rel; 1373 const Elf_Rela *relalim; 1374 const Elf_Rela *rela; 1375 elf_file_t ef = (elf_file_t)lf; 1376 1377 /* Perform relocations without addend if there are any: */ 1378 if ((rel = ef->rel) != NULL) { 1379 rellim = (const Elf_Rel *)((const char *)ef->rel + ef->relsize); 1380 while (rel < rellim) { 1381 elf_reloc_local(lf, (Elf_Addr)ef->address, rel, ELF_RELOC_REL, 1382 elf_lookup); 1383 rel++; 1384 } 1385 } 1386 1387 /* Perform relocations with addend if there are any: */ 1388 if ((rela = ef->rela) != NULL) { 1389 relalim = (const Elf_Rela *)((const char *)ef->rela + ef->relasize); 1390 while (rela < relalim) { 1391 elf_reloc_local(lf, (Elf_Addr)ef->address, rela, ELF_RELOC_RELA, 1392 elf_lookup); 1393 rela++; 1394 } 1395 } 1396}
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