1/*- 2 * Copyright (c) 1998-2000 Doug Rabson 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 */ 26 27#include <sys/cdefs.h> 28__FBSDID("$FreeBSD$"); 29 30#include "opt_ddb.h" 31#include "opt_gdb.h" 32 33#include <sys/param.h> 34#include <sys/systm.h> 35#ifdef GPROF 36#include <sys/gmon.h> 37#endif 38#include <sys/kernel.h> 39#include <sys/lock.h> 40#include <sys/malloc.h> 41#include <sys/mutex.h> 42#include <sys/mount.h> 43#include <sys/pcpu.h> 44#include <sys/proc.h> 45#include <sys/namei.h> 46#include <sys/fcntl.h> 47#include <sys/vnode.h> 48#include <sys/linker.h> 49 50#include <machine/elf.h> 51 52#include <net/vnet.h> 53 54#include <security/mac/mac_framework.h> 55 56#include <vm/vm.h> 57#include <vm/vm_param.h> 58#ifdef SPARSE_MAPPING 59#include <vm/vm_object.h> 60#include <vm/vm_kern.h> 61#include <vm/vm_extern.h> 62#endif 63#include <vm/pmap.h> 64#include <vm/vm_map.h> 65 66#include <sys/link_elf.h> 67 68#ifdef DDB_CTF 69#include <net/zlib.h> 70#endif 71 72#include "linker_if.h" 73 74#define MAXSEGS 4 75 76typedef struct elf_file { 77 struct linker_file lf; /* Common fields */ 78 int preloaded; /* Was file pre-loaded */ 79 caddr_t address; /* Relocation address */ 80#ifdef SPARSE_MAPPING 81 vm_object_t object; /* VM object to hold file pages */ 82#endif 83 Elf_Dyn *dynamic; /* Symbol table etc. */ 84 Elf_Hashelt nbuckets; /* DT_HASH info */ 85 Elf_Hashelt nchains; 86 const Elf_Hashelt *buckets; 87 const Elf_Hashelt *chains; 88 caddr_t hash; 89 caddr_t strtab; /* DT_STRTAB */ 90 int strsz; /* DT_STRSZ */ 91 const Elf_Sym *symtab; /* DT_SYMTAB */ 92 Elf_Addr *got; /* DT_PLTGOT */ 93 const Elf_Rel *pltrel; /* DT_JMPREL */ 94 int pltrelsize; /* DT_PLTRELSZ */ 95 const Elf_Rela *pltrela; /* DT_JMPREL */ 96 int pltrelasize; /* DT_PLTRELSZ */ 97 const Elf_Rel *rel; /* DT_REL */ 98 int relsize; /* DT_RELSZ */ 99 const Elf_Rela *rela; /* DT_RELA */ 100 int relasize; /* DT_RELASZ */ 101 caddr_t modptr; 102 const Elf_Sym *ddbsymtab; /* The symbol table we are using */ 103 long ddbsymcnt; /* Number of symbols */ 104 caddr_t ddbstrtab; /* String table */ 105 long ddbstrcnt; /* number of bytes in string table */ 106 caddr_t symbase; /* malloc'ed symbold base */ 107 caddr_t strbase; /* malloc'ed string base */ 108 caddr_t ctftab; /* CTF table */ 109 long ctfcnt; /* number of bytes in CTF table */ 110 caddr_t ctfoff; /* CTF offset table */ 111 caddr_t typoff; /* Type offset table */ 112 long typlen; /* Number of type entries. */ 113 Elf_Addr pcpu_start; /* Pre-relocation pcpu set start. */ 114 Elf_Addr pcpu_stop; /* Pre-relocation pcpu set stop. */ 115 Elf_Addr pcpu_base; /* Relocated pcpu set address. */ 116#ifdef VIMAGE 117 Elf_Addr vnet_start; /* Pre-relocation vnet set start. */ 118 Elf_Addr vnet_stop; /* Pre-relocation vnet set stop. */ 119 Elf_Addr vnet_base; /* Relocated vnet set address. */ 120#endif 121#ifdef GDB 122 struct link_map gdb; /* hooks for gdb */ 123#endif 124} *elf_file_t; 125 126struct elf_set { 127 Elf_Addr es_start; 128 Elf_Addr es_stop; 129 Elf_Addr es_base; 130 TAILQ_ENTRY(elf_set) es_link; 131}; 132 133TAILQ_HEAD(elf_set_head, elf_set); 134 135#include <kern/kern_ctf.c> 136 137static int link_elf_link_common_finish(linker_file_t); 138static int link_elf_link_preload(linker_class_t cls, 139 const char *, linker_file_t *); 140static int link_elf_link_preload_finish(linker_file_t); 141static int link_elf_load_file(linker_class_t, const char *, 142 linker_file_t *); 143static int link_elf_lookup_symbol(linker_file_t, const char *, 144 c_linker_sym_t *); 145static int link_elf_symbol_values(linker_file_t, c_linker_sym_t, 146 linker_symval_t *); 147static int link_elf_search_symbol(linker_file_t, caddr_t, 148 c_linker_sym_t *, long *); 149 150static void link_elf_unload_file(linker_file_t); 151static void link_elf_unload_preload(linker_file_t); 152static int link_elf_lookup_set(linker_file_t, const char *, 153 void ***, void ***, int *); 154static int link_elf_each_function_name(linker_file_t, 155 int (*)(const char *, void *), void *); 156static int link_elf_each_function_nameval(linker_file_t, 157 linker_function_nameval_callback_t, void *); 158static void link_elf_reloc_local(linker_file_t); 159static long link_elf_symtab_get(linker_file_t, const Elf_Sym **); 160static long link_elf_strtab_get(linker_file_t, caddr_t *); 161static Elf_Addr elf_lookup(linker_file_t, Elf_Size, int); 162 163static kobj_method_t link_elf_methods[] = { 164 KOBJMETHOD(linker_lookup_symbol, link_elf_lookup_symbol), 165 KOBJMETHOD(linker_symbol_values, link_elf_symbol_values), 166 KOBJMETHOD(linker_search_symbol, link_elf_search_symbol), 167 KOBJMETHOD(linker_unload, link_elf_unload_file), 168 KOBJMETHOD(linker_load_file, link_elf_load_file), 169 KOBJMETHOD(linker_link_preload, link_elf_link_preload), 170 KOBJMETHOD(linker_link_preload_finish, link_elf_link_preload_finish), 171 KOBJMETHOD(linker_lookup_set, link_elf_lookup_set), 172 KOBJMETHOD(linker_each_function_name, link_elf_each_function_name), 173 KOBJMETHOD(linker_each_function_nameval, link_elf_each_function_nameval), 174 KOBJMETHOD(linker_ctf_get, link_elf_ctf_get), 175 KOBJMETHOD(linker_symtab_get, link_elf_symtab_get), 176 KOBJMETHOD(linker_strtab_get, link_elf_strtab_get), 177 { 0, 0 } 178}; 179 180static struct linker_class link_elf_class = { 181#if ELF_TARG_CLASS == ELFCLASS32 182 "elf32", 183#else 184 "elf64", 185#endif 186 link_elf_methods, sizeof(struct elf_file) 187}; 188 189static int parse_dynamic(elf_file_t); 190static int relocate_file(elf_file_t); 191static int link_elf_preload_parse_symbols(elf_file_t); 192 193static struct elf_set_head set_pcpu_list; 194#ifdef VIMAGE 195static struct elf_set_head set_vnet_list; 196#endif 197 198static void 199elf_set_add(struct elf_set_head *list, Elf_Addr start, Elf_Addr stop, Elf_Addr base) 200{ 201 struct elf_set *set, *iter; 202 203 set = malloc(sizeof(*set), M_LINKER, M_WAITOK); 204 set->es_start = start; 205 set->es_stop = stop; 206 set->es_base = base; 207 208 TAILQ_FOREACH(iter, list, es_link) { 209 210 KASSERT((set->es_start < iter->es_start && set->es_stop < iter->es_stop) || 211 (set->es_start > iter->es_start && set->es_stop > iter->es_stop), 212 ("linker sets intersection: to insert: 0x%jx-0x%jx; inserted: 0x%jx-0x%jx", 213 (uintmax_t)set->es_start, (uintmax_t)set->es_stop, 214 (uintmax_t)iter->es_start, (uintmax_t)iter->es_stop)); 215 216 if (iter->es_start > set->es_start) { 217 TAILQ_INSERT_BEFORE(iter, set, es_link); 218 break; 219 } 220 } 221 222 if (iter == NULL) 223 TAILQ_INSERT_TAIL(list, set, es_link); 224} 225 226static int 227elf_set_find(struct elf_set_head *list, Elf_Addr addr, Elf_Addr *start, Elf_Addr *base) 228{ 229 struct elf_set *set; 230 231 TAILQ_FOREACH(set, list, es_link) { 232 if (addr < set->es_start) 233 return (0); 234 if (addr < set->es_stop) { 235 *start = set->es_start; 236 *base = set->es_base; 237 return (1); 238 } 239 } 240 241 return (0); 242} 243 244static void 245elf_set_delete(struct elf_set_head *list, Elf_Addr start) 246{ 247 struct elf_set *set; 248 249 TAILQ_FOREACH(set, list, es_link) { 250 if (start < set->es_start) 251 break; 252 if (start == set->es_start) { 253 TAILQ_REMOVE(list, set, es_link); 254 free(set, M_LINKER); 255 return; 256 } 257 } 258 KASSERT(0, ("deleting unknown linker set (start = 0x%jx)", 259 (uintmax_t)start)); 260} 261 262#ifdef GDB 263static void r_debug_state(struct r_debug *, struct link_map *); 264 265/* 266 * A list of loaded modules for GDB to use for loading symbols. 267 */ 268struct r_debug r_debug; 269 270#define GDB_STATE(s) do { \ 271 r_debug.r_state = s; r_debug_state(NULL, NULL); \ 272} while (0) 273 274/* 275 * Function for the debugger to set a breakpoint on to gain control. 276 */ 277static void 278r_debug_state(struct r_debug *dummy_one __unused, 279 struct link_map *dummy_two __unused) 280{ 281} 282 283static void 284link_elf_add_gdb(struct link_map *l) 285{ 286 struct link_map *prev; 287 288 l->l_next = NULL; 289 290 if (r_debug.r_map == NULL) { 291 /* Add first. */ 292 l->l_prev = NULL; 293 r_debug.r_map = l; 294 } else { 295 /* Append to list. */ 296 for (prev = r_debug.r_map; 297 prev->l_next != NULL; 298 prev = prev->l_next) 299 ; 300 l->l_prev = prev; 301 prev->l_next = l; 302 } 303} 304 305static void 306link_elf_delete_gdb(struct link_map *l) 307{ 308 if (l->l_prev == NULL) { 309 /* Remove first. */ 310 if ((r_debug.r_map = l->l_next) != NULL) 311 l->l_next->l_prev = NULL; 312 } else { 313 /* Remove any but first. */ 314 if ((l->l_prev->l_next = l->l_next) != NULL) 315 l->l_next->l_prev = l->l_prev; 316 } 317} 318#endif /* GDB */ 319 320#ifdef __ia64__ 321Elf_Addr link_elf_get_gp(linker_file_t); 322#endif 323 324/* 325 * The kernel symbol table starts here. 326 */ 327extern struct _dynamic _DYNAMIC; 328 329static void 330link_elf_error(const char *filename, const char *s) 331{ 332 if (filename == NULL) 333 printf("kldload: %s\n", s); 334 else 335 printf("kldload: %s: %s\n", filename, s); 336} 337 338/* 339 * Actions performed after linking/loading both the preloaded kernel and any 340 * modules; whether preloaded or dynamicly loaded. 341 */ 342static int 343link_elf_link_common_finish(linker_file_t lf) 344{ 345#ifdef GDB 346 elf_file_t ef = (elf_file_t)lf; 347 char *newfilename; 348#endif 349 int error; 350 351 /* Notify MD code that a module is being loaded. */ 352 error = elf_cpu_load_file(lf); 353 if (error != 0) 354 return (error); 355 356#ifdef GDB 357 GDB_STATE(RT_ADD); 358 ef->gdb.l_addr = lf->address; 359 newfilename = malloc(strlen(lf->filename) + 1, M_LINKER, M_WAITOK); 360 strcpy(newfilename, lf->filename); 361 ef->gdb.l_name = newfilename; 362 ef->gdb.l_ld = ef->dynamic; 363 link_elf_add_gdb(&ef->gdb); 364 GDB_STATE(RT_CONSISTENT); 365#endif 366 367 return (0); 368} 369 370static void 371link_elf_init(void* arg) 372{ 373 Elf_Dyn *dp; 374 caddr_t modptr, baseptr, sizeptr; 375 elf_file_t ef; 376 char *modname; 377 378 linker_add_class(&link_elf_class); 379 380 dp = (Elf_Dyn *)&_DYNAMIC; 381 modname = NULL; 382 modptr = preload_search_by_type("elf" __XSTRING(__ELF_WORD_SIZE) " kernel"); 383 if (modptr == NULL) 384 modptr = preload_search_by_type("elf kernel"); 385 if (modptr != NULL) 386 modname = (char *)preload_search_info(modptr, MODINFO_NAME); 387 if (modname == NULL) 388 modname = "kernel"; 389 linker_kernel_file = linker_make_file(modname, &link_elf_class); 390 if (linker_kernel_file == NULL) 391 panic("%s: Can't create linker structures for kernel", 392 __func__); 393 394 ef = (elf_file_t) linker_kernel_file; 395 ef->preloaded = 1; 396 ef->address = 0; 397#ifdef SPARSE_MAPPING 398 ef->object = 0; 399#endif 400 ef->dynamic = dp; 401 402 if (dp != NULL) 403 parse_dynamic(ef); 404 linker_kernel_file->address = (caddr_t) KERNBASE; 405 linker_kernel_file->size = -(intptr_t)linker_kernel_file->address; 406 407 if (modptr != NULL) { 408 ef->modptr = modptr; 409 baseptr = preload_search_info(modptr, MODINFO_ADDR); 410 if (baseptr != NULL) 411 linker_kernel_file->address = *(caddr_t *)baseptr; 412 sizeptr = preload_search_info(modptr, MODINFO_SIZE); 413 if (sizeptr != NULL) 414 linker_kernel_file->size = *(size_t *)sizeptr; 415 } 416 (void)link_elf_preload_parse_symbols(ef); 417 418#ifdef GDB 419 r_debug.r_map = NULL; 420 r_debug.r_brk = r_debug_state; 421 r_debug.r_state = RT_CONSISTENT; 422#endif 423 424 (void)link_elf_link_common_finish(linker_kernel_file); 425 linker_kernel_file->flags |= LINKER_FILE_LINKED; 426 TAILQ_INIT(&set_pcpu_list); 427#ifdef VIMAGE 428 TAILQ_INIT(&set_vnet_list); 429#endif 430} 431 432SYSINIT(link_elf, SI_SUB_KLD, SI_ORDER_THIRD, link_elf_init, 0); 433 434static int 435link_elf_preload_parse_symbols(elf_file_t ef) 436{ 437 caddr_t pointer; 438 caddr_t ssym, esym, base; 439 caddr_t strtab; 440 int strcnt; 441 Elf_Sym *symtab; 442 int symcnt; 443 444 if (ef->modptr == NULL) 445 return (0); 446 pointer = preload_search_info(ef->modptr, 447 MODINFO_METADATA | MODINFOMD_SSYM); 448 if (pointer == NULL) 449 return (0); 450 ssym = *(caddr_t *)pointer; 451 pointer = preload_search_info(ef->modptr, 452 MODINFO_METADATA | MODINFOMD_ESYM); 453 if (pointer == NULL) 454 return (0); 455 esym = *(caddr_t *)pointer; 456 457 base = ssym; 458 459 symcnt = *(long *)base; 460 base += sizeof(long); 461 symtab = (Elf_Sym *)base; 462 base += roundup(symcnt, sizeof(long)); 463 464 if (base > esym || base < ssym) { 465 printf("Symbols are corrupt!\n"); 466 return (EINVAL); 467 } 468 469 strcnt = *(long *)base; 470 base += sizeof(long); 471 strtab = base; 472 base += roundup(strcnt, sizeof(long)); 473 474 if (base > esym || base < ssym) { 475 printf("Symbols are corrupt!\n"); 476 return (EINVAL); 477 } 478 479 ef->ddbsymtab = symtab; 480 ef->ddbsymcnt = symcnt / sizeof(Elf_Sym); 481 ef->ddbstrtab = strtab; 482 ef->ddbstrcnt = strcnt; 483 484 return (0); 485} 486 487static int 488parse_dynamic(elf_file_t ef) 489{ 490 Elf_Dyn *dp; 491 int plttype = DT_REL; 492 493 for (dp = ef->dynamic; dp->d_tag != DT_NULL; dp++) { 494 switch (dp->d_tag) { 495 case DT_HASH: 496 { 497 /* From src/libexec/rtld-elf/rtld.c */ 498 const Elf_Hashelt *hashtab = (const Elf_Hashelt *) 499 (ef->address + dp->d_un.d_ptr); 500 ef->nbuckets = hashtab[0]; 501 ef->nchains = hashtab[1]; 502 ef->buckets = hashtab + 2; 503 ef->chains = ef->buckets + ef->nbuckets; 504 break; 505 } 506 case DT_STRTAB: 507 ef->strtab = (caddr_t) (ef->address + dp->d_un.d_ptr); 508 break; 509 case DT_STRSZ: 510 ef->strsz = dp->d_un.d_val; 511 break; 512 case DT_SYMTAB: 513 ef->symtab = (Elf_Sym*) (ef->address + dp->d_un.d_ptr); 514 break; 515 case DT_SYMENT: 516 if (dp->d_un.d_val != sizeof(Elf_Sym)) 517 return (ENOEXEC); 518 break; 519 case DT_PLTGOT: 520 ef->got = (Elf_Addr *) (ef->address + dp->d_un.d_ptr); 521 break; 522 case DT_REL: 523 ef->rel = (const Elf_Rel *) (ef->address + dp->d_un.d_ptr); 524 break; 525 case DT_RELSZ: 526 ef->relsize = dp->d_un.d_val; 527 break; 528 case DT_RELENT: 529 if (dp->d_un.d_val != sizeof(Elf_Rel)) 530 return (ENOEXEC); 531 break; 532 case DT_JMPREL: 533 ef->pltrel = (const Elf_Rel *) (ef->address + dp->d_un.d_ptr); 534 break; 535 case DT_PLTRELSZ: 536 ef->pltrelsize = dp->d_un.d_val; 537 break; 538 case DT_RELA: 539 ef->rela = (const Elf_Rela *) (ef->address + dp->d_un.d_ptr); 540 break; 541 case DT_RELASZ: 542 ef->relasize = dp->d_un.d_val; 543 break; 544 case DT_RELAENT: 545 if (dp->d_un.d_val != sizeof(Elf_Rela)) 546 return (ENOEXEC); 547 break; 548 case DT_PLTREL: 549 plttype = dp->d_un.d_val; 550 if (plttype != DT_REL && plttype != DT_RELA) 551 return (ENOEXEC); 552 break; 553#ifdef GDB 554 case DT_DEBUG: 555 dp->d_un.d_ptr = (Elf_Addr)&r_debug; 556 break; 557#endif 558 } 559 } 560 561 if (plttype == DT_RELA) { 562 ef->pltrela = (const Elf_Rela *)ef->pltrel; 563 ef->pltrel = NULL; 564 ef->pltrelasize = ef->pltrelsize; 565 ef->pltrelsize = 0; 566 } 567 568 ef->ddbsymtab = ef->symtab; 569 ef->ddbsymcnt = ef->nchains; 570 ef->ddbstrtab = ef->strtab; 571 ef->ddbstrcnt = ef->strsz; 572 573 return (0); 574} 575 576static int 577parse_dpcpu(elf_file_t ef) 578{ 579 int count; 580 int error; 581 582 ef->pcpu_start = 0; 583 ef->pcpu_stop = 0; 584 error = link_elf_lookup_set(&ef->lf, "pcpu", (void ***)&ef->pcpu_start, 585 (void ***)&ef->pcpu_stop, &count); 586 /* Error just means there is no pcpu set to relocate. */ 587 if (error != 0) 588 return (0); 589 count *= sizeof(void *); 590 /* 591 * Allocate space in the primary pcpu area. Copy in our 592 * initialization from the data section and then initialize 593 * all per-cpu storage from that. 594 */ 595 ef->pcpu_base = (Elf_Addr)(uintptr_t)dpcpu_alloc(count); 596 if (ef->pcpu_base == 0) 597 return (ENOSPC); 598 memcpy((void *)ef->pcpu_base, (void *)ef->pcpu_start, count); 599 dpcpu_copy((void *)ef->pcpu_base, count); 600 elf_set_add(&set_pcpu_list, ef->pcpu_start, ef->pcpu_stop, 601 ef->pcpu_base); 602 603 return (0); 604} 605 606#ifdef VIMAGE 607static int 608parse_vnet(elf_file_t ef) 609{ 610 int count; 611 int error; 612 613 ef->vnet_start = 0; 614 ef->vnet_stop = 0; 615 error = link_elf_lookup_set(&ef->lf, "vnet", (void ***)&ef->vnet_start, 616 (void ***)&ef->vnet_stop, &count); 617 /* Error just means there is no vnet data set to relocate. */ 618 if (error != 0) 619 return (0); 620 count *= sizeof(void *); 621 /* 622 * Allocate space in the primary vnet area. Copy in our 623 * initialization from the data section and then initialize 624 * all per-vnet storage from that. 625 */ 626 ef->vnet_base = (Elf_Addr)(uintptr_t)vnet_data_alloc(count); 627 if (ef->vnet_base == 0) 628 return (ENOSPC); 629 memcpy((void *)ef->vnet_base, (void *)ef->vnet_start, count); 630 vnet_data_copy((void *)ef->vnet_base, count); 631 elf_set_add(&set_vnet_list, ef->vnet_start, ef->vnet_stop, 632 ef->vnet_base); 633 634 return (0); 635} 636#endif 637 638static int 639link_elf_link_preload(linker_class_t cls, 640 const char* filename, linker_file_t *result) 641{ 642 caddr_t modptr, baseptr, sizeptr, dynptr; 643 char *type; 644 elf_file_t ef; 645 linker_file_t lf; 646 int error; 647 vm_offset_t dp; 648 649 /* Look to see if we have the file preloaded */ 650 modptr = preload_search_by_name(filename); 651 if (modptr == NULL) 652 return (ENOENT); 653 654 type = (char *)preload_search_info(modptr, MODINFO_TYPE); 655 baseptr = preload_search_info(modptr, MODINFO_ADDR); 656 sizeptr = preload_search_info(modptr, MODINFO_SIZE); 657 dynptr = preload_search_info(modptr, 658 MODINFO_METADATA | MODINFOMD_DYNAMIC); 659 if (type == NULL || 660 (strcmp(type, "elf" __XSTRING(__ELF_WORD_SIZE) " module") != 0 && 661 strcmp(type, "elf module") != 0)) 662 return (EFTYPE); 663 if (baseptr == NULL || sizeptr == NULL || dynptr == NULL) 664 return (EINVAL); 665 666 lf = linker_make_file(filename, &link_elf_class); 667 if (lf == NULL) 668 return (ENOMEM); 669 670 ef = (elf_file_t) lf; 671 ef->preloaded = 1; 672 ef->modptr = modptr; 673 ef->address = *(caddr_t *)baseptr; 674#ifdef SPARSE_MAPPING 675 ef->object = 0; 676#endif 677 dp = (vm_offset_t)ef->address + *(vm_offset_t *)dynptr; 678 ef->dynamic = (Elf_Dyn *)dp; 679 lf->address = ef->address; 680 lf->size = *(size_t *)sizeptr; 681 682 error = parse_dynamic(ef); 683 if (error == 0) 684 error = parse_dpcpu(ef); 685#ifdef VIMAGE 686 if (error == 0) 687 error = parse_vnet(ef); 688#endif 689 if (error != 0) { 690 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 691 return (error); 692 } 693 link_elf_reloc_local(lf); 694 *result = lf; 695 return (0); 696} 697 698static int 699link_elf_link_preload_finish(linker_file_t lf) 700{ 701 elf_file_t ef; 702 int error; 703 704 ef = (elf_file_t) lf; 705#if 0 /* this will be more trouble than it's worth for now */ 706 for (dp = ef->dynamic; dp->d_tag != DT_NULL; dp++) { 707 if (dp->d_tag != DT_NEEDED) 708 continue; 709 modname = ef->strtab + dp->d_un.d_val; 710 error = linker_load_module(modname, lf); 711 if (error != 0) 712 goto out; 713 } 714#endif 715 error = relocate_file(ef); 716 if (error != 0) 717 return (error); 718 (void)link_elf_preload_parse_symbols(ef); 719 720 return (link_elf_link_common_finish(lf)); 721} 722 723static int 724link_elf_load_file(linker_class_t cls, const char* filename, 725 linker_file_t* result) 726{ 727 struct nameidata nd; 728 struct thread* td = curthread; /* XXX */ 729 Elf_Ehdr *hdr; 730 caddr_t firstpage; 731 int nbytes, i; 732 Elf_Phdr *phdr; 733 Elf_Phdr *phlimit; 734 Elf_Phdr *segs[MAXSEGS]; 735 int nsegs; 736 Elf_Phdr *phdyn; 737 Elf_Phdr *phphdr; 738 caddr_t mapbase; 739 size_t mapsize; 740 Elf_Off base_offset; 741 Elf_Addr base_vaddr; 742 Elf_Addr base_vlimit; 743 int error = 0; 744 ssize_t resid; 745 int flags; 746 elf_file_t ef; 747 linker_file_t lf; 748 Elf_Shdr *shdr; 749 int symtabindex; 750 int symstrindex; 751 int symcnt; 752 int strcnt; 753 int vfslocked; 754 755 shdr = NULL; 756 lf = NULL; 757 758 NDINIT(&nd, LOOKUP, FOLLOW | MPSAFE, UIO_SYSSPACE, filename, td); 759 flags = FREAD; 760 error = vn_open(&nd, &flags, 0, NULL); 761 if (error != 0) 762 return (error); 763 vfslocked = NDHASGIANT(&nd); 764 NDFREE(&nd, NDF_ONLY_PNBUF); 765 if (nd.ni_vp->v_type != VREG) { 766 error = ENOEXEC; 767 firstpage = NULL; 768 goto out; 769 } 770#ifdef MAC 771 error = mac_kld_check_load(curthread->td_ucred, nd.ni_vp); 772 if (error != 0) { 773 firstpage = NULL; 774 goto out; 775 } 776#endif 777 778 /* 779 * Read the elf header from the file. 780 */ 781 firstpage = malloc(PAGE_SIZE, M_LINKER, M_WAITOK); 782 hdr = (Elf_Ehdr *)firstpage; 783 error = vn_rdwr(UIO_READ, nd.ni_vp, firstpage, PAGE_SIZE, 0, 784 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 785 &resid, td); 786 nbytes = PAGE_SIZE - resid; 787 if (error != 0) 788 goto out; 789 790 if (!IS_ELF(*hdr)) { 791 error = ENOEXEC; 792 goto out; 793 } 794 795 if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS || 796 hdr->e_ident[EI_DATA] != ELF_TARG_DATA) { 797 link_elf_error(filename, "Unsupported file layout"); 798 error = ENOEXEC; 799 goto out; 800 } 801 if (hdr->e_ident[EI_VERSION] != EV_CURRENT || 802 hdr->e_version != EV_CURRENT) { 803 link_elf_error(filename, "Unsupported file version"); 804 error = ENOEXEC; 805 goto out; 806 } 807 if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN) { 808 error = ENOSYS; 809 goto out; 810 } 811 if (hdr->e_machine != ELF_TARG_MACH) { 812 link_elf_error(filename, "Unsupported machine"); 813 error = ENOEXEC; 814 goto out; 815 } 816 817 /* 818 * We rely on the program header being in the first page. 819 * This is not strictly required by the ABI specification, but 820 * it seems to always true in practice. And, it simplifies 821 * things considerably. 822 */ 823 if (!((hdr->e_phentsize == sizeof(Elf_Phdr)) && 824 (hdr->e_phoff + hdr->e_phnum*sizeof(Elf_Phdr) <= PAGE_SIZE) && 825 (hdr->e_phoff + hdr->e_phnum*sizeof(Elf_Phdr) <= nbytes))) 826 link_elf_error(filename, "Unreadable program headers"); 827 828 /* 829 * Scan the program header entries, and save key information. 830 * 831 * We rely on there being exactly two load segments, text and data, 832 * in that order. 833 */ 834 phdr = (Elf_Phdr *) (firstpage + hdr->e_phoff); 835 phlimit = phdr + hdr->e_phnum; 836 nsegs = 0; 837 phdyn = NULL; 838 phphdr = NULL; 839 while (phdr < phlimit) { 840 switch (phdr->p_type) { 841 case PT_LOAD: 842 if (nsegs == MAXSEGS) { 843 link_elf_error(filename, "Too many sections"); 844 error = ENOEXEC; 845 goto out; 846 } 847 /* 848 * XXX: We just trust they come in right order ?? 849 */ 850 segs[nsegs] = phdr; 851 ++nsegs; 852 break; 853 854 case PT_PHDR: 855 phphdr = phdr; 856 break; 857 858 case PT_DYNAMIC: 859 phdyn = phdr; 860 break; 861 862 case PT_INTERP: 863 error = ENOSYS; 864 goto out; 865 } 866 867 ++phdr; 868 } 869 if (phdyn == NULL) { 870 link_elf_error(filename, "Object is not dynamically-linked"); 871 error = ENOEXEC; 872 goto out; 873 } 874 if (nsegs == 0) { 875 link_elf_error(filename, "No sections"); 876 error = ENOEXEC; 877 goto out; 878 } 879 880 /* 881 * Allocate the entire address space of the object, to stake 882 * out our contiguous region, and to establish the base 883 * address for relocation. 884 */ 885 base_offset = trunc_page(segs[0]->p_offset); 886 base_vaddr = trunc_page(segs[0]->p_vaddr); 887 base_vlimit = round_page(segs[nsegs - 1]->p_vaddr + 888 segs[nsegs - 1]->p_memsz); 889 mapsize = base_vlimit - base_vaddr; 890 891 lf = linker_make_file(filename, &link_elf_class); 892 if (lf == NULL) { 893 error = ENOMEM; 894 goto out; 895 } 896 897 ef = (elf_file_t) lf; 898#ifdef SPARSE_MAPPING 899 ef->object = vm_object_allocate(OBJT_DEFAULT, mapsize >> PAGE_SHIFT); 900 if (ef->object == NULL) { 901 error = ENOMEM; 902 goto out; 903 } 904 ef->address = (caddr_t) vm_map_min(kernel_map); 905 error = vm_map_find(kernel_map, ef->object, 0, 906 (vm_offset_t *) &ef->address, mapsize, 1, 907 VM_PROT_ALL, VM_PROT_ALL, 0); 908 if (error != 0) { 909 vm_object_deallocate(ef->object); 910 ef->object = 0; 911 goto out; 912 } 913#else 914 ef->address = malloc(mapsize, M_LINKER, M_WAITOK); 915#endif 916 mapbase = ef->address; 917 918 /* 919 * Read the text and data sections and zero the bss. 920 */ 921 for (i = 0; i < nsegs; i++) { 922 caddr_t segbase = mapbase + segs[i]->p_vaddr - base_vaddr; 923 error = vn_rdwr(UIO_READ, nd.ni_vp, 924 segbase, segs[i]->p_filesz, segs[i]->p_offset, 925 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 926 &resid, td); 927 if (error != 0) 928 goto out; 929 bzero(segbase + segs[i]->p_filesz, 930 segs[i]->p_memsz - segs[i]->p_filesz); 931 932#ifdef SPARSE_MAPPING 933 /* 934 * Wire down the pages 935 */ 936 error = vm_map_wire(kernel_map, 937 (vm_offset_t) segbase, 938 (vm_offset_t) segbase + segs[i]->p_memsz, 939 VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES); 940 if (error != KERN_SUCCESS) { 941 error = ENOMEM; 942 goto out; 943 } 944#endif 945 } 946 947#ifdef GPROF 948 /* Update profiling information with the new text segment. */ 949 mtx_lock(&Giant); 950 kmupetext((uintfptr_t)(mapbase + segs[0]->p_vaddr - base_vaddr + 951 segs[0]->p_memsz)); 952 mtx_unlock(&Giant); 953#endif 954 955 ef->dynamic = (Elf_Dyn *) (mapbase + phdyn->p_vaddr - base_vaddr); 956 957 lf->address = ef->address; 958 lf->size = mapsize; 959 960 error = parse_dynamic(ef); 961 if (error != 0) 962 goto out; 963 error = parse_dpcpu(ef); 964 if (error != 0) 965 goto out; 966#ifdef VIMAGE 967 error = parse_vnet(ef); 968 if (error != 0) 969 goto out; 970#endif 971 link_elf_reloc_local(lf); 972 973 VOP_UNLOCK(nd.ni_vp, 0); 974 error = linker_load_dependencies(lf); 975 vn_lock(nd.ni_vp, LK_EXCLUSIVE | LK_RETRY); 976 if (error != 0) 977 goto out; 978#if 0 /* this will be more trouble than it's worth for now */ 979 for (dp = ef->dynamic; dp->d_tag != DT_NULL; dp++) { 980 if (dp->d_tag != DT_NEEDED) 981 continue; 982 modname = ef->strtab + dp->d_un.d_val; 983 error = linker_load_module(modname, lf); 984 if (error != 0) 985 goto out; 986 } 987#endif 988 error = relocate_file(ef); 989 if (error != 0) 990 goto out; 991 992 /* 993 * Try and load the symbol table if it's present. (you can 994 * strip it!) 995 */ 996 nbytes = hdr->e_shnum * hdr->e_shentsize; 997 if (nbytes == 0 || hdr->e_shoff == 0) 998 goto nosyms; 999 shdr = malloc(nbytes, M_LINKER, M_WAITOK | M_ZERO); 1000 error = vn_rdwr(UIO_READ, nd.ni_vp, 1001 (caddr_t)shdr, nbytes, hdr->e_shoff, 1002 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 1003 &resid, td); 1004 if (error != 0) 1005 goto out; 1006 symtabindex = -1; 1007 symstrindex = -1; 1008 for (i = 0; i < hdr->e_shnum; i++) { 1009 if (shdr[i].sh_type == SHT_SYMTAB) { 1010 symtabindex = i; 1011 symstrindex = shdr[i].sh_link; 1012 } 1013 } 1014 if (symtabindex < 0 || symstrindex < 0) 1015 goto nosyms; 1016 1017 symcnt = shdr[symtabindex].sh_size; 1018 ef->symbase = malloc(symcnt, M_LINKER, M_WAITOK); 1019 strcnt = shdr[symstrindex].sh_size; 1020 ef->strbase = malloc(strcnt, M_LINKER, M_WAITOK); 1021 1022 error = vn_rdwr(UIO_READ, nd.ni_vp, 1023 ef->symbase, symcnt, shdr[symtabindex].sh_offset, 1024 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 1025 &resid, td); 1026 if (error != 0) 1027 goto out; 1028 error = vn_rdwr(UIO_READ, nd.ni_vp, 1029 ef->strbase, strcnt, shdr[symstrindex].sh_offset, 1030 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 1031 &resid, td); 1032 if (error != 0) 1033 goto out; 1034 1035 ef->ddbsymcnt = symcnt / sizeof(Elf_Sym); 1036 ef->ddbsymtab = (const Elf_Sym *)ef->symbase; 1037 ef->ddbstrcnt = strcnt; 1038 ef->ddbstrtab = ef->strbase; 1039 1040nosyms: 1041 error = link_elf_link_common_finish(lf); 1042 if (error != 0) 1043 goto out; 1044 1045 *result = lf; 1046 1047out: 1048 VOP_UNLOCK(nd.ni_vp, 0); 1049 vn_close(nd.ni_vp, FREAD, td->td_ucred, td); 1050 VFS_UNLOCK_GIANT(vfslocked); 1051 if (error != 0 && lf != NULL) 1052 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 1053 if (shdr != NULL) 1054 free(shdr, M_LINKER); 1055 if (firstpage != NULL) 1056 free(firstpage, M_LINKER); 1057 1058 return (error); 1059} 1060 1061Elf_Addr 1062elf_relocaddr(linker_file_t lf, Elf_Addr x) 1063{ 1064 elf_file_t ef; 1065 1066 ef = (elf_file_t)lf; 1067 if (x >= ef->pcpu_start && x < ef->pcpu_stop) 1068 return ((x - ef->pcpu_start) + ef->pcpu_base); 1069#ifdef VIMAGE 1070 if (x >= ef->vnet_start && x < ef->vnet_stop) 1071 return ((x - ef->vnet_start) + ef->vnet_base); 1072#endif 1073 return (x); 1074} 1075 1076 1077static void 1078link_elf_unload_file(linker_file_t file) 1079{ 1080 elf_file_t ef = (elf_file_t) file; 1081 1082 if (ef->pcpu_base != 0) { 1083 dpcpu_free((void *)ef->pcpu_base, 1084 ef->pcpu_stop - ef->pcpu_start); 1085 elf_set_delete(&set_pcpu_list, ef->pcpu_start); 1086 } 1087#ifdef VIMAGE 1088 if (ef->vnet_base != 0) { 1089 vnet_data_free((void *)ef->vnet_base, 1090 ef->vnet_stop - ef->vnet_start); 1091 elf_set_delete(&set_vnet_list, ef->vnet_start); 1092 } 1093#endif 1094#ifdef GDB 1095 if (ef->gdb.l_ld != NULL) { 1096 GDB_STATE(RT_DELETE); 1097 free((void *)(uintptr_t)ef->gdb.l_name, M_LINKER); 1098 link_elf_delete_gdb(&ef->gdb); 1099 GDB_STATE(RT_CONSISTENT); 1100 } 1101#endif 1102 1103 /* Notify MD code that a module is being unloaded. */ 1104 elf_cpu_unload_file(file); 1105 1106 if (ef->preloaded) { 1107 link_elf_unload_preload(file); 1108 return; 1109 } 1110 1111#ifdef SPARSE_MAPPING 1112 if (ef->object != NULL) { 1113 vm_map_remove(kernel_map, (vm_offset_t) ef->address, 1114 (vm_offset_t) ef->address 1115 + (ef->object->size << PAGE_SHIFT)); 1116 } 1117#else 1118 if (ef->address != NULL) 1119 free(ef->address, M_LINKER); 1120#endif 1121 if (ef->symbase != NULL) 1122 free(ef->symbase, M_LINKER); 1123 if (ef->strbase != NULL) 1124 free(ef->strbase, M_LINKER); 1125 if (ef->ctftab != NULL) 1126 free(ef->ctftab, M_LINKER); 1127 if (ef->ctfoff != NULL) 1128 free(ef->ctfoff, M_LINKER); 1129 if (ef->typoff != NULL) 1130 free(ef->typoff, M_LINKER); 1131} 1132 1133static void 1134link_elf_unload_preload(linker_file_t file) 1135{ 1136 if (file->filename != NULL) 1137 preload_delete_name(file->filename); 1138} 1139 1140static const char * 1141symbol_name(elf_file_t ef, Elf_Size r_info) 1142{ 1143 const Elf_Sym *ref; 1144 1145 if (ELF_R_SYM(r_info)) { 1146 ref = ef->symtab + ELF_R_SYM(r_info); 1147 return (ef->strtab + ref->st_name); 1148 } 1149 return (NULL); 1150} 1151 1152static int 1153relocate_file(elf_file_t ef) 1154{ 1155 const Elf_Rel *rellim; 1156 const Elf_Rel *rel; 1157 const Elf_Rela *relalim; 1158 const Elf_Rela *rela; 1159 const char *symname; 1160 1161 /* Perform relocations without addend if there are any: */ 1162 rel = ef->rel; 1163 if (rel != NULL) { 1164 rellim = (const Elf_Rel *) 1165 ((const char *)ef->rel + ef->relsize); 1166 while (rel < rellim) { 1167 if (elf_reloc(&ef->lf, (Elf_Addr)ef->address, rel, 1168 ELF_RELOC_REL, elf_lookup)) { 1169 symname = symbol_name(ef, rel->r_info); 1170 printf("link_elf: symbol %s undefined\n", symname); 1171 return (ENOENT); 1172 } 1173 rel++; 1174 } 1175 } 1176 1177 /* Perform relocations with addend if there are any: */ 1178 rela = ef->rela; 1179 if (rela != NULL) { 1180 relalim = (const Elf_Rela *) 1181 ((const char *)ef->rela + ef->relasize); 1182 while (rela < relalim) { 1183 if (elf_reloc(&ef->lf, (Elf_Addr)ef->address, rela, 1184 ELF_RELOC_RELA, elf_lookup)) { 1185 symname = symbol_name(ef, rela->r_info); 1186 printf("link_elf: symbol %s undefined\n", 1187 symname); 1188 return (ENOENT); 1189 } 1190 rela++; 1191 } 1192 } 1193 1194 /* Perform PLT relocations without addend if there are any: */ 1195 rel = ef->pltrel; 1196 if (rel != NULL) { 1197 rellim = (const Elf_Rel *) 1198 ((const char *)ef->pltrel + ef->pltrelsize); 1199 while (rel < rellim) { 1200 if (elf_reloc(&ef->lf, (Elf_Addr)ef->address, rel, 1201 ELF_RELOC_REL, elf_lookup)) { 1202 symname = symbol_name(ef, rel->r_info); 1203 printf("link_elf: symbol %s undefined\n", 1204 symname); 1205 return (ENOENT); 1206 } 1207 rel++; 1208 } 1209 } 1210 1211 /* Perform relocations with addend if there are any: */ 1212 rela = ef->pltrela; 1213 if (rela != NULL) { 1214 relalim = (const Elf_Rela *) 1215 ((const char *)ef->pltrela + ef->pltrelasize); 1216 while (rela < relalim) { 1217 if (elf_reloc(&ef->lf, (Elf_Addr)ef->address, rela, 1218 ELF_RELOC_RELA, elf_lookup)) { 1219 symname = symbol_name(ef, rela->r_info); 1220 printf("link_elf: symbol %s undefined\n", 1221 symname); 1222 return (ENOENT); 1223 } 1224 rela++; 1225 } 1226 } 1227 1228 return (0); 1229} 1230 1231/* 1232 * Hash function for symbol table lookup. Don't even think about changing 1233 * this. It is specified by the System V ABI. 1234 */ 1235static unsigned long 1236elf_hash(const char *name) 1237{ 1238 const unsigned char *p = (const unsigned char *) name; 1239 unsigned long h = 0; 1240 unsigned long g; 1241 1242 while (*p != '\0') { 1243 h = (h << 4) + *p++; 1244 if ((g = h & 0xf0000000) != 0) 1245 h ^= g >> 24; 1246 h &= ~g; 1247 } 1248 return (h); 1249} 1250 1251static int 1252link_elf_lookup_symbol(linker_file_t lf, const char* name, c_linker_sym_t* sym) 1253{ 1254 elf_file_t ef = (elf_file_t) lf; 1255 unsigned long symnum; 1256 const Elf_Sym* symp; 1257 const char *strp; 1258 unsigned long hash; 1259 int i; 1260 1261 /* If we don't have a hash, bail. */ 1262 if (ef->buckets == NULL || ef->nbuckets == 0) { 1263 printf("link_elf_lookup_symbol: missing symbol hash table\n"); 1264 return (ENOENT); 1265 } 1266 1267 /* First, search hashed global symbols */ 1268 hash = elf_hash(name); 1269 symnum = ef->buckets[hash % ef->nbuckets]; 1270 1271 while (symnum != STN_UNDEF) { 1272 if (symnum >= ef->nchains) { 1273 printf("%s: corrupt symbol table\n", __func__); 1274 return (ENOENT); 1275 } 1276 1277 symp = ef->symtab + symnum; 1278 if (symp->st_name == 0) { 1279 printf("%s: corrupt symbol table\n", __func__); 1280 return (ENOENT); 1281 } 1282 1283 strp = ef->strtab + symp->st_name; 1284 1285 if (strcmp(name, strp) == 0) { 1286 if (symp->st_shndx != SHN_UNDEF || 1287 (symp->st_value != 0 && 1288 ELF_ST_TYPE(symp->st_info) == STT_FUNC)) { 1289 *sym = (c_linker_sym_t) symp; 1290 return (0); 1291 } 1292 return (ENOENT); 1293 } 1294 1295 symnum = ef->chains[symnum]; 1296 } 1297 1298 /* If we have not found it, look at the full table (if loaded) */ 1299 if (ef->symtab == ef->ddbsymtab) 1300 return (ENOENT); 1301 1302 /* Exhaustive search */ 1303 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) { 1304 strp = ef->ddbstrtab + symp->st_name; 1305 if (strcmp(name, strp) == 0) { 1306 if (symp->st_shndx != SHN_UNDEF || 1307 (symp->st_value != 0 && 1308 ELF_ST_TYPE(symp->st_info) == STT_FUNC)) { 1309 *sym = (c_linker_sym_t) symp; 1310 return (0); 1311 } 1312 return (ENOENT); 1313 } 1314 } 1315 1316 return (ENOENT); 1317} 1318 1319static int 1320link_elf_symbol_values(linker_file_t lf, c_linker_sym_t sym, 1321 linker_symval_t *symval) 1322{ 1323 elf_file_t ef = (elf_file_t) lf; 1324 const Elf_Sym* es = (const Elf_Sym*) sym; 1325 1326 if (es >= ef->symtab && es < (ef->symtab + ef->nchains)) { 1327 symval->name = ef->strtab + es->st_name; 1328 symval->value = (caddr_t) ef->address + es->st_value; 1329 symval->size = es->st_size; 1330 return (0); 1331 } 1332 if (ef->symtab == ef->ddbsymtab) 1333 return (ENOENT); 1334 if (es >= ef->ddbsymtab && es < (ef->ddbsymtab + ef->ddbsymcnt)) { 1335 symval->name = ef->ddbstrtab + es->st_name; 1336 symval->value = (caddr_t) ef->address + es->st_value; 1337 symval->size = es->st_size; 1338 return (0); 1339 } 1340 return (ENOENT); 1341} 1342 1343static int 1344link_elf_search_symbol(linker_file_t lf, caddr_t value, 1345 c_linker_sym_t *sym, long *diffp) 1346{ 1347 elf_file_t ef = (elf_file_t) lf; 1348 u_long off = (uintptr_t) (void *) value; 1349 u_long diff = off; 1350 u_long st_value; 1351 const Elf_Sym* es; 1352 const Elf_Sym* best = 0; 1353 int i; 1354 1355 for (i = 0, es = ef->ddbsymtab; i < ef->ddbsymcnt; i++, es++) { 1356 if (es->st_name == 0) 1357 continue; 1358 st_value = es->st_value + (uintptr_t) (void *) ef->address; 1359 if (off >= st_value) { 1360 if (off - st_value < diff) { 1361 diff = off - st_value; 1362 best = es; 1363 if (diff == 0) 1364 break; 1365 } else if (off - st_value == diff) { 1366 best = es; 1367 } 1368 } 1369 } 1370 if (best == 0) 1371 *diffp = off; 1372 else 1373 *diffp = diff; 1374 *sym = (c_linker_sym_t) best; 1375 1376 return (0); 1377} 1378 1379/* 1380 * Look up a linker set on an ELF system. 1381 */ 1382static int 1383link_elf_lookup_set(linker_file_t lf, const char *name, 1384 void ***startp, void ***stopp, int *countp) 1385{ 1386 c_linker_sym_t sym; 1387 linker_symval_t symval; 1388 char *setsym; 1389 void **start, **stop; 1390 int len, error = 0, count; 1391 1392 len = strlen(name) + sizeof("__start_set_"); /* sizeof includes \0 */ 1393 setsym = malloc(len, M_LINKER, M_WAITOK); 1394 1395 /* get address of first entry */ 1396 snprintf(setsym, len, "%s%s", "__start_set_", name); 1397 error = link_elf_lookup_symbol(lf, setsym, &sym); 1398 if (error != 0) 1399 goto out; 1400 link_elf_symbol_values(lf, sym, &symval); 1401 if (symval.value == 0) { 1402 error = ESRCH; 1403 goto out; 1404 } 1405 start = (void **)symval.value; 1406 1407 /* get address of last entry */ 1408 snprintf(setsym, len, "%s%s", "__stop_set_", name); 1409 error = link_elf_lookup_symbol(lf, setsym, &sym); 1410 if (error != 0) 1411 goto out; 1412 link_elf_symbol_values(lf, sym, &symval); 1413 if (symval.value == 0) { 1414 error = ESRCH; 1415 goto out; 1416 } 1417 stop = (void **)symval.value; 1418 1419 /* and the number of entries */ 1420 count = stop - start; 1421 1422 /* and copy out */ 1423 if (startp != NULL) 1424 *startp = start; 1425 if (stopp != NULL) 1426 *stopp = stop; 1427 if (countp != NULL) 1428 *countp = count; 1429 1430out: 1431 free(setsym, M_LINKER); 1432 return (error); 1433} 1434 1435static int 1436link_elf_each_function_name(linker_file_t file, 1437 int (*callback)(const char *, void *), void *opaque) 1438{ 1439 elf_file_t ef = (elf_file_t)file; 1440 const Elf_Sym *symp; 1441 int i, error; 1442 1443 /* Exhaustive search */ 1444 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) { 1445 if (symp->st_value != 0 && 1446 ELF_ST_TYPE(symp->st_info) == STT_FUNC) { 1447 error = callback(ef->ddbstrtab + symp->st_name, opaque); 1448 if (error != 0) 1449 return (error); 1450 } 1451 } 1452 return (0); 1453} 1454 1455static int 1456link_elf_each_function_nameval(linker_file_t file, 1457 linker_function_nameval_callback_t callback, void *opaque) 1458{ 1459 linker_symval_t symval; 1460 elf_file_t ef = (elf_file_t)file; 1461 const Elf_Sym* symp; 1462 int i, error; 1463 1464 /* Exhaustive search */ 1465 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) { 1466 if (symp->st_value != 0 && 1467 ELF_ST_TYPE(symp->st_info) == STT_FUNC) { 1468 error = link_elf_symbol_values(file, 1469 (c_linker_sym_t) symp, &symval); 1470 if (error != 0) 1471 return (error); 1472 error = callback(file, i, &symval, opaque); 1473 if (error != 0) 1474 return (error); 1475 } 1476 } 1477 return (0); 1478} 1479 1480#ifdef __ia64__ 1481/* 1482 * Each KLD has its own GP. The GP value for each load module is given by 1483 * DT_PLTGOT on ia64. We need GP to construct function descriptors, but 1484 * don't have direct access to the ELF file structure. The link_elf_get_gp() 1485 * function returns the GP given a pointer to a generic linker file struct. 1486 */ 1487Elf_Addr 1488link_elf_get_gp(linker_file_t lf) 1489{ 1490 elf_file_t ef = (elf_file_t)lf; 1491 return ((Elf_Addr)ef->got); 1492} 1493#endif 1494 1495const Elf_Sym * 1496elf_get_sym(linker_file_t lf, Elf_Size symidx) 1497{ 1498 elf_file_t ef = (elf_file_t)lf; 1499 1500 if (symidx >= ef->nchains) 1501 return (NULL); 1502 return (ef->symtab + symidx); 1503} 1504 1505const char * 1506elf_get_symname(linker_file_t lf, Elf_Size symidx) 1507{ 1508 elf_file_t ef = (elf_file_t)lf; 1509 const Elf_Sym *sym; 1510 1511 if (symidx >= ef->nchains) 1512 return (NULL); 1513 sym = ef->symtab + symidx; 1514 return (ef->strtab + sym->st_name); 1515} 1516 1517/* 1518 * Symbol lookup function that can be used when the symbol index is known (ie 1519 * in relocations). It uses the symbol index instead of doing a fully fledged 1520 * hash table based lookup when such is valid. For example for local symbols. 1521 * This is not only more efficient, it's also more correct. It's not always 1522 * the case that the symbol can be found through the hash table. 1523 */ 1524static Elf_Addr 1525elf_lookup(linker_file_t lf, Elf_Size symidx, int deps) 1526{ 1527 elf_file_t ef = (elf_file_t)lf; 1528 const Elf_Sym *sym; 1529 const char *symbol; 1530 Elf_Addr addr, start, base; 1531 1532 /* Don't even try to lookup the symbol if the index is bogus. */ 1533 if (symidx >= ef->nchains) 1534 return (0); 1535 1536 sym = ef->symtab + symidx; 1537 1538 /* 1539 * Don't do a full lookup when the symbol is local. It may even 1540 * fail because it may not be found through the hash table. 1541 */ 1542 if (ELF_ST_BIND(sym->st_info) == STB_LOCAL) { 1543 /* Force lookup failure when we have an insanity. */ 1544 if (sym->st_shndx == SHN_UNDEF || sym->st_value == 0) 1545 return (0); 1546 return ((Elf_Addr)ef->address + sym->st_value); 1547 } 1548 1549 /* 1550 * XXX we can avoid doing a hash table based lookup for global 1551 * symbols as well. This however is not always valid, so we'll 1552 * just do it the hard way for now. Performance tweaks can 1553 * always be added. 1554 */ 1555 1556 symbol = ef->strtab + sym->st_name; 1557 1558 /* Force a lookup failure if the symbol name is bogus. */ 1559 if (*symbol == 0) 1560 return (0); 1561 1562 addr = ((Elf_Addr)linker_file_lookup_symbol(lf, symbol, deps)); 1563 1564 if (elf_set_find(&set_pcpu_list, addr, &start, &base)) 1565 addr = addr - start + base; 1566#ifdef VIMAGE 1567 else if (elf_set_find(&set_vnet_list, addr, &start, &base)) 1568 addr = addr - start + base; 1569#endif 1570 return addr; 1571} 1572 1573static void 1574link_elf_reloc_local(linker_file_t lf) 1575{ 1576 const Elf_Rel *rellim; 1577 const Elf_Rel *rel; 1578 const Elf_Rela *relalim; 1579 const Elf_Rela *rela; 1580 elf_file_t ef = (elf_file_t)lf; 1581 1582 /* Perform relocations without addend if there are any: */ 1583 if ((rel = ef->rel) != NULL) { 1584 rellim = (const Elf_Rel *)((const char *)ef->rel + ef->relsize); 1585 while (rel < rellim) { 1586 elf_reloc_local(lf, (Elf_Addr)ef->address, rel, 1587 ELF_RELOC_REL, elf_lookup); 1588 rel++; 1589 } 1590 } 1591 1592 /* Perform relocations with addend if there are any: */ 1593 if ((rela = ef->rela) != NULL) { 1594 relalim = (const Elf_Rela *) 1595 ((const char *)ef->rela + ef->relasize); 1596 while (rela < relalim) { 1597 elf_reloc_local(lf, (Elf_Addr)ef->address, rela, 1598 ELF_RELOC_RELA, elf_lookup); 1599 rela++; 1600 } 1601 } 1602} 1603 1604static long 1605link_elf_symtab_get(linker_file_t lf, const Elf_Sym **symtab) 1606{ 1607 elf_file_t ef = (elf_file_t)lf; 1608 1609 *symtab = ef->ddbsymtab; 1610 1611 if (*symtab == NULL) 1612 return (0); 1613 1614 return (ef->ddbsymcnt); 1615} 1616 1617static long 1618link_elf_strtab_get(linker_file_t lf, caddr_t *strtab) 1619{ 1620 elf_file_t ef = (elf_file_t)lf; 1621 1622 *strtab = ef->ddbstrtab; 1623 1624 if (*strtab == NULL) 1625 return (0); 1626 1627 return (ef->ddbstrcnt); 1628} 1629