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 76 typedef 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; 125 126 struct 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 }; 132 133 TAILQ_HEAD(elf_set_head, elf_set); 134 135 #include <kern/kern_ctf.c> 136 137 static int link_elf_link_common_finish(linker_file_t); 138 static int link_elf_link_preload(linker_class_t cls, 139 const char *, linker_file_t *); 140 static int link_elf_link_preload_finish(linker_file_t); 141 static int link_elf_load_file(linker_class_t, const char *, 142 linker_file_t *); 143 static int link_elf_lookup_symbol(linker_file_t, const char *, 144 c_linker_sym_t *); 145 static int link_elf_symbol_values(linker_file_t, c_linker_sym_t, 146 linker_symval_t *); 147 static int link_elf_search_symbol(linker_file_t, caddr_t, 148 c_linker_sym_t *, long *); 149 150 static void link_elf_unload_file(linker_file_t); 151 static void link_elf_unload_preload(linker_file_t); 152 static int link_elf_lookup_set(linker_file_t, const char *, 153 void ***, void ***, int *); 154 static int link_elf_each_function_name(linker_file_t, 155 int (*)(const char *, void *), void *); 156 static int link_elf_each_function_nameval(linker_file_t, 157 linker_function_nameval_callback_t, void *); 158 static void link_elf_reloc_local(linker_file_t); 159 static long link_elf_symtab_get(linker_file_t, const Elf_Sym **); 160 static long link_elf_strtab_get(linker_file_t, caddr_t *); 161 static Elf_Addr elf_lookup(linker_file_t, Elf_Size, int); 162 163 static 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 }; 179 180 static 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 }; 188 189 static int parse_dynamic(elf_file_t); 190 static int relocate_file(elf_file_t); 191 static int link_elf_preload_parse_symbols(elf_file_t); 192 193 static struct elf_set_head set_pcpu_list; 194 #ifdef VIMAGE 195 static struct elf_set_head set_vnet_list; 196 #endif 197 198 static void 199 elf_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 } 225 226 static int 227 elf_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 } 243 244 static void 245 elf_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 263 static 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 */ 268 struct 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 */ 277 static void 278 r_debug_state(struct r_debug *dummy_one __unused, 279 struct link_map *dummy_two __unused) 280 { 281 } 282 283 static void 284 link_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 } 304 305 static void 306 link_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 /* 321 * The kernel symbol table starts here. 322 */ 323 extern struct _dynamic _DYNAMIC; 324 325 static void 326 link_elf_error(const char *filename, const char *s) 327 { 328 if (filename == NULL) 329 printf("kldload: %s\n", s); 330 else 331 printf("kldload: %s: %s\n", filename, s); 332 } 333 334 /* 335 * Actions performed after linking/loading both the preloaded kernel and any 336 * modules; whether preloaded or dynamicly loaded. 337 */ 338 static int 339 link_elf_link_common_finish(linker_file_t lf) 340 { 341 #ifdef GDB 342 elf_file_t ef = (elf_file_t)lf; 343 char *newfilename; 344 #endif 345 int error; 346 347 /* Notify MD code that a module is being loaded. */ 348 error = elf_cpu_load_file(lf); 349 if (error != 0) 350 return (error); 351 352 #ifdef GDB 353 GDB_STATE(RT_ADD); 354 ef->gdb.l_addr = lf->address; 355 newfilename = malloc(strlen(lf->filename) + 1, M_LINKER, M_WAITOK); 356 strcpy(newfilename, lf->filename); 357 ef->gdb.l_name = newfilename; 358 ef->gdb.l_ld = ef->dynamic; 359 link_elf_add_gdb(&ef->gdb); 360 GDB_STATE(RT_CONSISTENT); 361 #endif 362 363 return (0); 364 } 365 366 static void 367 link_elf_init(void* arg) 368 { 369 Elf_Dyn *dp; 370 caddr_t modptr, baseptr, sizeptr; 371 elf_file_t ef; 372 char *modname; 373 374 linker_add_class(&link_elf_class); 375 376 dp = (Elf_Dyn *)&_DYNAMIC; 377 modname = NULL; 378 modptr = preload_search_by_type("elf" __XSTRING(__ELF_WORD_SIZE) " kernel"); 379 if (modptr == NULL) 380 modptr = preload_search_by_type("elf kernel"); 381 if (modptr != NULL) 382 modname = (char *)preload_search_info(modptr, MODINFO_NAME); 383 if (modname == NULL) 384 modname = "kernel"; 385 linker_kernel_file = linker_make_file(modname, &link_elf_class); 386 if (linker_kernel_file == NULL) 387 panic("%s: Can't create linker structures for kernel", 388 __func__); 389 390 ef = (elf_file_t) linker_kernel_file; 391 ef->preloaded = 1; 392 ef->address = 0; 393 #ifdef SPARSE_MAPPING 394 ef->object = 0; 395 #endif 396 ef->dynamic = dp; 397 398 if (dp != NULL) 399 parse_dynamic(ef); 400 linker_kernel_file->address = (caddr_t) KERNBASE; 401 linker_kernel_file->size = -(intptr_t)linker_kernel_file->address; 402 403 if (modptr != NULL) { 404 ef->modptr = modptr; 405 baseptr = preload_search_info(modptr, MODINFO_ADDR); 406 if (baseptr != NULL) 407 linker_kernel_file->address = *(caddr_t *)baseptr; 408 sizeptr = preload_search_info(modptr, MODINFO_SIZE); 409 if (sizeptr != NULL) 410 linker_kernel_file->size = *(size_t *)sizeptr; 411 } 412 (void)link_elf_preload_parse_symbols(ef); 413 414 #ifdef GDB 415 r_debug.r_map = NULL; 416 r_debug.r_brk = r_debug_state; 417 r_debug.r_state = RT_CONSISTENT; 418 #endif 419 420 (void)link_elf_link_common_finish(linker_kernel_file); 421 linker_kernel_file->flags |= LINKER_FILE_LINKED; 422 TAILQ_INIT(&set_pcpu_list); 423 #ifdef VIMAGE 424 TAILQ_INIT(&set_vnet_list); 425 #endif 426 } 427 428 SYSINIT(link_elf, SI_SUB_KLD, SI_ORDER_THIRD, link_elf_init, 0); 429 430 static int 431 link_elf_preload_parse_symbols(elf_file_t ef) 432 { 433 caddr_t pointer; 434 caddr_t ssym, esym, base; 435 caddr_t strtab; 436 int strcnt; 437 Elf_Sym *symtab; 438 int symcnt; 439 440 if (ef->modptr == NULL) 441 return (0); 442 pointer = preload_search_info(ef->modptr, 443 MODINFO_METADATA | MODINFOMD_SSYM); 444 if (pointer == NULL) 445 return (0); 446 ssym = *(caddr_t *)pointer; 447 pointer = preload_search_info(ef->modptr, 448 MODINFO_METADATA | MODINFOMD_ESYM); 449 if (pointer == NULL) 450 return (0); 451 esym = *(caddr_t *)pointer; 452 453 base = ssym; 454 455 symcnt = *(long *)base; 456 base += sizeof(long); 457 symtab = (Elf_Sym *)base; 458 base += roundup(symcnt, sizeof(long)); 459 460 if (base > esym || base < ssym) { 461 printf("Symbols are corrupt!\n"); 462 return (EINVAL); 463 } 464 465 strcnt = *(long *)base; 466 base += sizeof(long); 467 strtab = base; 468 base += roundup(strcnt, sizeof(long)); 469 470 if (base > esym || base < ssym) { 471 printf("Symbols are corrupt!\n"); 472 return (EINVAL); 473 } 474 475 ef->ddbsymtab = symtab; 476 ef->ddbsymcnt = symcnt / sizeof(Elf_Sym); 477 ef->ddbstrtab = strtab; 478 ef->ddbstrcnt = strcnt; 479 480 return (0); 481 } 482 483 static int 484 parse_dynamic(elf_file_t ef) 485 { 486 Elf_Dyn *dp; 487 int plttype = DT_REL; 488 489 for (dp = ef->dynamic; dp->d_tag != DT_NULL; dp++) { 490 switch (dp->d_tag) { 491 case DT_HASH: 492 { 493 /* From src/libexec/rtld-elf/rtld.c */ 494 const Elf_Hashelt *hashtab = (const Elf_Hashelt *) 495 (ef->address + dp->d_un.d_ptr); 496 ef->nbuckets = hashtab[0]; 497 ef->nchains = hashtab[1]; 498 ef->buckets = hashtab + 2; 499 ef->chains = ef->buckets + ef->nbuckets; 500 break; 501 } 502 case DT_STRTAB: 503 ef->strtab = (caddr_t) (ef->address + dp->d_un.d_ptr); 504 break; 505 case DT_STRSZ: 506 ef->strsz = dp->d_un.d_val; 507 break; 508 case DT_SYMTAB: 509 ef->symtab = (Elf_Sym*) (ef->address + dp->d_un.d_ptr); 510 break; 511 case DT_SYMENT: 512 if (dp->d_un.d_val != sizeof(Elf_Sym)) 513 return (ENOEXEC); 514 break; 515 case DT_PLTGOT: 516 ef->got = (Elf_Addr *) (ef->address + dp->d_un.d_ptr); 517 break; 518 case DT_REL: 519 ef->rel = (const Elf_Rel *) (ef->address + dp->d_un.d_ptr); 520 break; 521 case DT_RELSZ: 522 ef->relsize = dp->d_un.d_val; 523 break; 524 case DT_RELENT: 525 if (dp->d_un.d_val != sizeof(Elf_Rel)) 526 return (ENOEXEC); 527 break; 528 case DT_JMPREL: 529 ef->pltrel = (const Elf_Rel *) (ef->address + dp->d_un.d_ptr); 530 break; 531 case DT_PLTRELSZ: 532 ef->pltrelsize = dp->d_un.d_val; 533 break; 534 case DT_RELA: 535 ef->rela = (const Elf_Rela *) (ef->address + dp->d_un.d_ptr); 536 break; 537 case DT_RELASZ: 538 ef->relasize = dp->d_un.d_val; 539 break; 540 case DT_RELAENT: 541 if (dp->d_un.d_val != sizeof(Elf_Rela)) 542 return (ENOEXEC); 543 break; 544 case DT_PLTREL: 545 plttype = dp->d_un.d_val; 546 if (plttype != DT_REL && plttype != DT_RELA) 547 return (ENOEXEC); 548 break; 549 #ifdef GDB 550 case DT_DEBUG: 551 dp->d_un.d_ptr = (Elf_Addr)&r_debug; 552 break; 553 #endif 554 } 555 } 556 557 if (plttype == DT_RELA) { 558 ef->pltrela = (const Elf_Rela *)ef->pltrel; 559 ef->pltrel = NULL; 560 ef->pltrelasize = ef->pltrelsize; 561 ef->pltrelsize = 0; 562 } 563 564 ef->ddbsymtab = ef->symtab; 565 ef->ddbsymcnt = ef->nchains; 566 ef->ddbstrtab = ef->strtab; 567 ef->ddbstrcnt = ef->strsz; 568 569 return (0); 570 } 571 572 static int 573 parse_dpcpu(elf_file_t ef) 574 { 575 int count; 576 int error; 577 578 ef->pcpu_start = 0; 579 ef->pcpu_stop = 0; 580 error = link_elf_lookup_set(&ef->lf, "pcpu", (void ***)&ef->pcpu_start, 581 (void ***)&ef->pcpu_stop, &count); 582 /* Error just means there is no pcpu set to relocate. */ 583 if (error != 0) 584 return (0); 585 count *= sizeof(void *); 586 /* 587 * Allocate space in the primary pcpu area. Copy in our 588 * initialization from the data section and then initialize 589 * all per-cpu storage from that. 590 */ 591 ef->pcpu_base = (Elf_Addr)(uintptr_t)dpcpu_alloc(count); 592 if (ef->pcpu_base == 0) 593 return (ENOSPC); 594 memcpy((void *)ef->pcpu_base, (void *)ef->pcpu_start, count); 595 dpcpu_copy((void *)ef->pcpu_base, count); 596 elf_set_add(&set_pcpu_list, ef->pcpu_start, ef->pcpu_stop, 597 ef->pcpu_base); 598 599 return (0); 600 } 601 602 #ifdef VIMAGE 603 static int 604 parse_vnet(elf_file_t ef) 605 { 606 int count; 607 int error; 608 609 ef->vnet_start = 0; 610 ef->vnet_stop = 0; 611 error = link_elf_lookup_set(&ef->lf, "vnet", (void ***)&ef->vnet_start, 612 (void ***)&ef->vnet_stop, &count); 613 /* Error just means there is no vnet data set to relocate. */ 614 if (error != 0) 615 return (0); 616 count *= sizeof(void *); 617 /* 618 * Allocate space in the primary vnet area. Copy in our 619 * initialization from the data section and then initialize 620 * all per-vnet storage from that. 621 */ 622 ef->vnet_base = (Elf_Addr)(uintptr_t)vnet_data_alloc(count); 623 if (ef->vnet_base == 0) 624 return (ENOSPC); 625 memcpy((void *)ef->vnet_base, (void *)ef->vnet_start, count); 626 vnet_data_copy((void *)ef->vnet_base, count); 627 elf_set_add(&set_vnet_list, ef->vnet_start, ef->vnet_stop, 628 ef->vnet_base); 629 630 return (0); 631 } 632 #endif 633 634 static int 635 link_elf_link_preload(linker_class_t cls, 636 const char* filename, linker_file_t *result) 637 { 638 caddr_t modptr, baseptr, sizeptr, dynptr; 639 char *type; 640 elf_file_t ef; 641 linker_file_t lf; 642 int error; 643 vm_offset_t dp; 644 645 /* Look to see if we have the file preloaded */ 646 modptr = preload_search_by_name(filename); 647 if (modptr == NULL) 648 return (ENOENT); 649 650 type = (char *)preload_search_info(modptr, MODINFO_TYPE); 651 baseptr = preload_search_info(modptr, MODINFO_ADDR); 652 sizeptr = preload_search_info(modptr, MODINFO_SIZE); 653 dynptr = preload_search_info(modptr, 654 MODINFO_METADATA | MODINFOMD_DYNAMIC); 655 if (type == NULL || 656 (strcmp(type, "elf" __XSTRING(__ELF_WORD_SIZE) " module") != 0 && 657 strcmp(type, "elf module") != 0)) 658 return (EFTYPE); 659 if (baseptr == NULL || sizeptr == NULL || dynptr == NULL) 660 return (EINVAL); 661 662 lf = linker_make_file(filename, &link_elf_class); 663 if (lf == NULL) 664 return (ENOMEM); 665 666 ef = (elf_file_t) lf; 667 ef->preloaded = 1; 668 ef->modptr = modptr; 669 ef->address = *(caddr_t *)baseptr; 670 #ifdef SPARSE_MAPPING 671 ef->object = 0; 672 #endif 673 dp = (vm_offset_t)ef->address + *(vm_offset_t *)dynptr; 674 ef->dynamic = (Elf_Dyn *)dp; 675 lf->address = ef->address; 676 lf->size = *(size_t *)sizeptr; 677 678 error = parse_dynamic(ef); 679 if (error == 0) 680 error = parse_dpcpu(ef); 681 #ifdef VIMAGE 682 if (error == 0) 683 error = parse_vnet(ef); 684 #endif 685 if (error != 0) { 686 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 687 return (error); 688 } 689 link_elf_reloc_local(lf); 690 *result = lf; 691 return (0); 692 } 693 694 static int 695 link_elf_link_preload_finish(linker_file_t lf) 696 { 697 elf_file_t ef; 698 int error; 699 700 ef = (elf_file_t) lf; 701 error = relocate_file(ef); 702 if (error != 0) 703 return (error); 704 (void)link_elf_preload_parse_symbols(ef); 705 706 return (link_elf_link_common_finish(lf)); 707 } 708 709 static int 710 link_elf_load_file(linker_class_t cls, const char* filename, 711 linker_file_t* result) 712 { 713 struct nameidata nd; 714 struct thread* td = curthread; /* XXX */ 715 Elf_Ehdr *hdr; 716 caddr_t firstpage; 717 int nbytes, i; 718 Elf_Phdr *phdr; 719 Elf_Phdr *phlimit; 720 Elf_Phdr *segs[MAXSEGS]; 721 int nsegs; 722 Elf_Phdr *phdyn; 723 Elf_Phdr *phphdr; 724 caddr_t mapbase; 725 size_t mapsize; 726 Elf_Off base_offset; 727 Elf_Addr base_vaddr; 728 Elf_Addr base_vlimit; 729 int error = 0; 730 ssize_t resid; 731 int flags; 732 elf_file_t ef; 733 linker_file_t lf; 734 Elf_Shdr *shdr; 735 int symtabindex; 736 int symstrindex; 737 int symcnt; 738 int strcnt; 739 740 shdr = NULL; 741 lf = NULL; 742 743 NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, filename, td); 744 flags = FREAD; 745 error = vn_open(&nd, &flags, 0, NULL); 746 if (error != 0) 747 return (error); 748 NDFREE(&nd, NDF_ONLY_PNBUF); 749 if (nd.ni_vp->v_type != VREG) { 750 error = ENOEXEC; 751 firstpage = NULL; 752 goto out; 753 } 754 #ifdef MAC 755 error = mac_kld_check_load(curthread->td_ucred, nd.ni_vp); 756 if (error != 0) { 757 firstpage = NULL; 758 goto out; 759 } 760 #endif 761 762 /* 763 * Read the elf header from the file. 764 */ 765 firstpage = malloc(PAGE_SIZE, M_LINKER, M_WAITOK); 766 hdr = (Elf_Ehdr *)firstpage; 767 error = vn_rdwr(UIO_READ, nd.ni_vp, firstpage, PAGE_SIZE, 0, 768 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 769 &resid, td); 770 nbytes = PAGE_SIZE - resid; 771 if (error != 0) 772 goto out; 773 774 if (!IS_ELF(*hdr)) { 775 error = ENOEXEC; 776 goto out; 777 } 778 779 if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS || 780 hdr->e_ident[EI_DATA] != ELF_TARG_DATA) { 781 link_elf_error(filename, "Unsupported file layout"); 782 error = ENOEXEC; 783 goto out; 784 } 785 if (hdr->e_ident[EI_VERSION] != EV_CURRENT || 786 hdr->e_version != EV_CURRENT) { 787 link_elf_error(filename, "Unsupported file version"); 788 error = ENOEXEC; 789 goto out; 790 } 791 if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN) { 792 error = ENOSYS; 793 goto out; 794 } 795 if (hdr->e_machine != ELF_TARG_MACH) { 796 link_elf_error(filename, "Unsupported machine"); 797 error = ENOEXEC; 798 goto out; 799 } 800 801 /* 802 * We rely on the program header being in the first page. 803 * This is not strictly required by the ABI specification, but 804 * it seems to always true in practice. And, it simplifies 805 * things considerably. 806 */ 807 if (!((hdr->e_phentsize == sizeof(Elf_Phdr)) && 808 (hdr->e_phoff + hdr->e_phnum*sizeof(Elf_Phdr) <= PAGE_SIZE) && 809 (hdr->e_phoff + hdr->e_phnum*sizeof(Elf_Phdr) <= nbytes))) 810 link_elf_error(filename, "Unreadable program headers"); 811 812 /* 813 * Scan the program header entries, and save key information. 814 * 815 * We rely on there being exactly two load segments, text and data, 816 * in that order. 817 */ 818 phdr = (Elf_Phdr *) (firstpage + hdr->e_phoff); 819 phlimit = phdr + hdr->e_phnum; 820 nsegs = 0; 821 phdyn = NULL; 822 phphdr = NULL; 823 while (phdr < phlimit) { 824 switch (phdr->p_type) { 825 case PT_LOAD: 826 if (nsegs == MAXSEGS) { 827 link_elf_error(filename, "Too many sections"); 828 error = ENOEXEC; 829 goto out; 830 } 831 /* 832 * XXX: We just trust they come in right order ?? 833 */ 834 segs[nsegs] = phdr; 835 ++nsegs; 836 break; 837 838 case PT_PHDR: 839 phphdr = phdr; 840 break; 841 842 case PT_DYNAMIC: 843 phdyn = phdr; 844 break; 845 846 case PT_INTERP: 847 error = ENOSYS; 848 goto out; 849 } 850 851 ++phdr; 852 } 853 if (phdyn == NULL) { 854 link_elf_error(filename, "Object is not dynamically-linked"); 855 error = ENOEXEC; 856 goto out; 857 } 858 if (nsegs == 0) { 859 link_elf_error(filename, "No sections"); 860 error = ENOEXEC; 861 goto out; 862 } 863 864 /* 865 * Allocate the entire address space of the object, to stake 866 * out our contiguous region, and to establish the base 867 * address for relocation. 868 */ 869 base_offset = trunc_page(segs[0]->p_offset); 870 base_vaddr = trunc_page(segs[0]->p_vaddr); 871 base_vlimit = round_page(segs[nsegs - 1]->p_vaddr + 872 segs[nsegs - 1]->p_memsz); 873 mapsize = base_vlimit - base_vaddr; 874 875 lf = linker_make_file(filename, &link_elf_class); 876 if (lf == NULL) { 877 error = ENOMEM; 878 goto out; 879 } 880 881 ef = (elf_file_t) lf; 882 #ifdef SPARSE_MAPPING 883 ef->object = vm_object_allocate(OBJT_DEFAULT, mapsize >> PAGE_SHIFT); 884 if (ef->object == NULL) { 885 error = ENOMEM; 886 goto out; 887 } 888 ef->address = (caddr_t) vm_map_min(kernel_map); 889 error = vm_map_find(kernel_map, ef->object, 0, 890 (vm_offset_t *) &ef->address, mapsize, 0, VMFS_OPTIMAL_SPACE, 891 VM_PROT_ALL, VM_PROT_ALL, 0); 892 if (error != 0) { 893 vm_object_deallocate(ef->object); 894 ef->object = 0; 895 goto out; 896 } 897 #else 898 ef->address = malloc(mapsize, M_LINKER, M_WAITOK); 899 #endif 900 mapbase = ef->address; 901 902 /* 903 * Read the text and data sections and zero the bss. 904 */ 905 for (i = 0; i < nsegs; i++) { 906 caddr_t segbase = mapbase + segs[i]->p_vaddr - base_vaddr; 907 error = vn_rdwr(UIO_READ, nd.ni_vp, 908 segbase, segs[i]->p_filesz, segs[i]->p_offset, 909 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 910 &resid, td); 911 if (error != 0) 912 goto out; 913 bzero(segbase + segs[i]->p_filesz, 914 segs[i]->p_memsz - segs[i]->p_filesz); 915 916 #ifdef SPARSE_MAPPING 917 /* 918 * Wire down the pages 919 */ 920 error = vm_map_wire(kernel_map, 921 (vm_offset_t) segbase, 922 (vm_offset_t) segbase + segs[i]->p_memsz, 923 VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES); 924 if (error != KERN_SUCCESS) { 925 error = ENOMEM; 926 goto out; 927 } 928 #endif 929 } 930 931 #ifdef GPROF 932 /* Update profiling information with the new text segment. */ 933 mtx_lock(&Giant); 934 kmupetext((uintfptr_t)(mapbase + segs[0]->p_vaddr - base_vaddr + 935 segs[0]->p_memsz)); 936 mtx_unlock(&Giant); 937 #endif 938 939 ef->dynamic = (Elf_Dyn *) (mapbase + phdyn->p_vaddr - base_vaddr); 940 941 lf->address = ef->address; 942 lf->size = mapsize; 943 944 error = parse_dynamic(ef); 945 if (error != 0) 946 goto out; 947 error = parse_dpcpu(ef); 948 if (error != 0) 949 goto out; 950 #ifdef VIMAGE 951 error = parse_vnet(ef); 952 if (error != 0) 953 goto out; 954 #endif 955 link_elf_reloc_local(lf); 956 957 VOP_UNLOCK(nd.ni_vp, 0); 958 error = linker_load_dependencies(lf); 959 vn_lock(nd.ni_vp, LK_EXCLUSIVE | LK_RETRY); 960 if (error != 0) 961 goto out; 962 error = relocate_file(ef); 963 if (error != 0) 964 goto out; 965 966 /* 967 * Try and load the symbol table if it's present. (you can 968 * strip it!) 969 */ 970 nbytes = hdr->e_shnum * hdr->e_shentsize; 971 if (nbytes == 0 || hdr->e_shoff == 0) 972 goto nosyms; 973 shdr = malloc(nbytes, M_LINKER, M_WAITOK | M_ZERO); 974 error = vn_rdwr(UIO_READ, nd.ni_vp, 975 (caddr_t)shdr, nbytes, hdr->e_shoff, 976 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 977 &resid, td); 978 if (error != 0) 979 goto out; 980 symtabindex = -1; 981 symstrindex = -1; 982 for (i = 0; i < hdr->e_shnum; i++) { 983 if (shdr[i].sh_type == SHT_SYMTAB) { 984 symtabindex = i; 985 symstrindex = shdr[i].sh_link; 986 } 987 } 988 if (symtabindex < 0 || symstrindex < 0) 989 goto nosyms; 990 991 symcnt = shdr[symtabindex].sh_size; 992 ef->symbase = malloc(symcnt, M_LINKER, M_WAITOK); 993 strcnt = shdr[symstrindex].sh_size; 994 ef->strbase = malloc(strcnt, M_LINKER, M_WAITOK); 995 996 error = vn_rdwr(UIO_READ, nd.ni_vp, 997 ef->symbase, symcnt, shdr[symtabindex].sh_offset, 998 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 999 &resid, td); 1000 if (error != 0) 1001 goto out; 1002 error = vn_rdwr(UIO_READ, nd.ni_vp, 1003 ef->strbase, strcnt, shdr[symstrindex].sh_offset, 1004 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 1005 &resid, td); 1006 if (error != 0) 1007 goto out; 1008 1009 ef->ddbsymcnt = symcnt / sizeof(Elf_Sym); 1010 ef->ddbsymtab = (const Elf_Sym *)ef->symbase; 1011 ef->ddbstrcnt = strcnt; 1012 ef->ddbstrtab = ef->strbase; 1013 1014 nosyms: 1015 error = link_elf_link_common_finish(lf); 1016 if (error != 0) 1017 goto out; 1018 1019 *result = lf; 1020 1021 out: 1022 VOP_UNLOCK(nd.ni_vp, 0); 1023 vn_close(nd.ni_vp, FREAD, td->td_ucred, td); 1024 if (error != 0 && lf != NULL) 1025 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 1026 if (shdr != NULL) 1027 free(shdr, M_LINKER); 1028 if (firstpage != NULL) 1029 free(firstpage, M_LINKER); 1030 1031 return (error); 1032 } 1033 1034 Elf_Addr 1035 elf_relocaddr(linker_file_t lf, Elf_Addr x) 1036 { 1037 elf_file_t ef; 1038 1039 ef = (elf_file_t)lf; 1040 if (x >= ef->pcpu_start && x < ef->pcpu_stop) 1041 return ((x - ef->pcpu_start) + ef->pcpu_base); 1042 #ifdef VIMAGE 1043 if (x >= ef->vnet_start && x < ef->vnet_stop) 1044 return ((x - ef->vnet_start) + ef->vnet_base); 1045 #endif 1046 return (x); 1047 } 1048 1049 1050 static void 1051 link_elf_unload_file(linker_file_t file) 1052 { 1053 elf_file_t ef = (elf_file_t) file; 1054 1055 if (ef->pcpu_base != 0) { 1056 dpcpu_free((void *)ef->pcpu_base, 1057 ef->pcpu_stop - ef->pcpu_start); 1058 elf_set_delete(&set_pcpu_list, ef->pcpu_start); 1059 } 1060 #ifdef VIMAGE 1061 if (ef->vnet_base != 0) { 1062 vnet_data_free((void *)ef->vnet_base, 1063 ef->vnet_stop - ef->vnet_start); 1064 elf_set_delete(&set_vnet_list, ef->vnet_start); 1065 } 1066 #endif 1067 #ifdef GDB 1068 if (ef->gdb.l_ld != NULL) { 1069 GDB_STATE(RT_DELETE); 1070 free((void *)(uintptr_t)ef->gdb.l_name, M_LINKER); 1071 link_elf_delete_gdb(&ef->gdb); 1072 GDB_STATE(RT_CONSISTENT); 1073 } 1074 #endif 1075 1076 /* Notify MD code that a module is being unloaded. */ 1077 elf_cpu_unload_file(file); 1078 1079 if (ef->preloaded) { 1080 link_elf_unload_preload(file); 1081 return; 1082 } 1083 1084 #ifdef SPARSE_MAPPING 1085 if (ef->object != NULL) { 1086 vm_map_remove(kernel_map, (vm_offset_t) ef->address, 1087 (vm_offset_t) ef->address 1088 + (ef->object->size << PAGE_SHIFT)); 1089 } 1090 #else 1091 if (ef->address != NULL) 1092 free(ef->address, M_LINKER); 1093 #endif 1094 if (ef->symbase != NULL) 1095 free(ef->symbase, M_LINKER); 1096 if (ef->strbase != NULL) 1097 free(ef->strbase, M_LINKER); 1098 if (ef->ctftab != NULL) 1099 free(ef->ctftab, M_LINKER); 1100 if (ef->ctfoff != NULL) 1101 free(ef->ctfoff, M_LINKER); 1102 if (ef->typoff != NULL) 1103 free(ef->typoff, M_LINKER); 1104 } 1105 1106 static void 1107 link_elf_unload_preload(linker_file_t file) 1108 { 1109 if (file->filename != NULL) 1110 preload_delete_name(file->filename); 1111 } 1112 1113 static const char * 1114 symbol_name(elf_file_t ef, Elf_Size r_info) 1115 { 1116 const Elf_Sym *ref; 1117 1118 if (ELF_R_SYM(r_info)) { 1119 ref = ef->symtab + ELF_R_SYM(r_info); 1120 return (ef->strtab + ref->st_name); 1121 } 1122 return (NULL); 1123 } 1124 1125 static int 1126 relocate_file(elf_file_t ef) 1127 { 1128 const Elf_Rel *rellim; 1129 const Elf_Rel *rel; 1130 const Elf_Rela *relalim; 1131 const Elf_Rela *rela; 1132 const char *symname; 1133 1134 /* Perform relocations without addend if there are any: */ 1135 rel = ef->rel; 1136 if (rel != NULL) { 1137 rellim = (const Elf_Rel *) 1138 ((const char *)ef->rel + ef->relsize); 1139 while (rel < rellim) { 1140 if (elf_reloc(&ef->lf, (Elf_Addr)ef->address, rel, 1141 ELF_RELOC_REL, elf_lookup)) { 1142 symname = symbol_name(ef, rel->r_info); 1143 printf("link_elf: symbol %s undefined\n", symname); 1144 return (ENOENT); 1145 } 1146 rel++; 1147 } 1148 } 1149 1150 /* Perform relocations with addend if there are any: */ 1151 rela = ef->rela; 1152 if (rela != NULL) { 1153 relalim = (const Elf_Rela *) 1154 ((const char *)ef->rela + ef->relasize); 1155 while (rela < relalim) { 1156 if (elf_reloc(&ef->lf, (Elf_Addr)ef->address, rela, 1157 ELF_RELOC_RELA, elf_lookup)) { 1158 symname = symbol_name(ef, rela->r_info); 1159 printf("link_elf: symbol %s undefined\n", 1160 symname); 1161 return (ENOENT); 1162 } 1163 rela++; 1164 } 1165 } 1166 1167 /* Perform PLT relocations without addend if there are any: */ 1168 rel = ef->pltrel; 1169 if (rel != NULL) { 1170 rellim = (const Elf_Rel *) 1171 ((const char *)ef->pltrel + ef->pltrelsize); 1172 while (rel < rellim) { 1173 if (elf_reloc(&ef->lf, (Elf_Addr)ef->address, rel, 1174 ELF_RELOC_REL, elf_lookup)) { 1175 symname = symbol_name(ef, rel->r_info); 1176 printf("link_elf: symbol %s undefined\n", 1177 symname); 1178 return (ENOENT); 1179 } 1180 rel++; 1181 } 1182 } 1183 1184 /* Perform relocations with addend if there are any: */ 1185 rela = ef->pltrela; 1186 if (rela != NULL) { 1187 relalim = (const Elf_Rela *) 1188 ((const char *)ef->pltrela + ef->pltrelasize); 1189 while (rela < relalim) { 1190 if (elf_reloc(&ef->lf, (Elf_Addr)ef->address, rela, 1191 ELF_RELOC_RELA, elf_lookup)) { 1192 symname = symbol_name(ef, rela->r_info); 1193 printf("link_elf: symbol %s undefined\n", 1194 symname); 1195 return (ENOENT); 1196 } 1197 rela++; 1198 } 1199 } 1200 1201 return (0); 1202 } 1203 1204 /* 1205 * Hash function for symbol table lookup. Don't even think about changing 1206 * this. It is specified by the System V ABI. 1207 */ 1208 static unsigned long 1209 elf_hash(const char *name) 1210 { 1211 const unsigned char *p = (const unsigned char *) name; 1212 unsigned long h = 0; 1213 unsigned long g; 1214 1215 while (*p != '\0') { 1216 h = (h << 4) + *p++; 1217 if ((g = h & 0xf0000000) != 0) 1218 h ^= g >> 24; 1219 h &= ~g; 1220 } 1221 return (h); 1222 } 1223 1224 static int 1225 link_elf_lookup_symbol(linker_file_t lf, const char* name, c_linker_sym_t* sym) 1226 { 1227 elf_file_t ef = (elf_file_t) lf; 1228 unsigned long symnum; 1229 const Elf_Sym* symp; 1230 const char *strp; 1231 unsigned long hash; 1232 int i; 1233 1234 /* If we don't have a hash, bail. */ 1235 if (ef->buckets == NULL || ef->nbuckets == 0) { 1236 printf("link_elf_lookup_symbol: missing symbol hash table\n"); 1237 return (ENOENT); 1238 } 1239 1240 /* First, search hashed global symbols */ 1241 hash = elf_hash(name); 1242 symnum = ef->buckets[hash % ef->nbuckets]; 1243 1244 while (symnum != STN_UNDEF) { 1245 if (symnum >= ef->nchains) { 1246 printf("%s: corrupt symbol table\n", __func__); 1247 return (ENOENT); 1248 } 1249 1250 symp = ef->symtab + symnum; 1251 if (symp->st_name == 0) { 1252 printf("%s: corrupt symbol table\n", __func__); 1253 return (ENOENT); 1254 } 1255 1256 strp = ef->strtab + symp->st_name; 1257 1258 if (strcmp(name, strp) == 0) { 1259 if (symp->st_shndx != SHN_UNDEF || 1260 (symp->st_value != 0 && 1261 ELF_ST_TYPE(symp->st_info) == STT_FUNC)) { 1262 *sym = (c_linker_sym_t) symp; 1263 return (0); 1264 } 1265 return (ENOENT); 1266 } 1267 1268 symnum = ef->chains[symnum]; 1269 } 1270 1271 /* If we have not found it, look at the full table (if loaded) */ 1272 if (ef->symtab == ef->ddbsymtab) 1273 return (ENOENT); 1274 1275 /* Exhaustive search */ 1276 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) { 1277 strp = ef->ddbstrtab + symp->st_name; 1278 if (strcmp(name, strp) == 0) { 1279 if (symp->st_shndx != SHN_UNDEF || 1280 (symp->st_value != 0 && 1281 ELF_ST_TYPE(symp->st_info) == STT_FUNC)) { 1282 *sym = (c_linker_sym_t) symp; 1283 return (0); 1284 } 1285 return (ENOENT); 1286 } 1287 } 1288 1289 return (ENOENT); 1290 } 1291 1292 static int 1293 link_elf_symbol_values(linker_file_t lf, c_linker_sym_t sym, 1294 linker_symval_t *symval) 1295 { 1296 elf_file_t ef = (elf_file_t) lf; 1297 const Elf_Sym* es = (const Elf_Sym*) sym; 1298 1299 if (es >= ef->symtab && es < (ef->symtab + ef->nchains)) { 1300 symval->name = ef->strtab + es->st_name; 1301 symval->value = (caddr_t) ef->address + es->st_value; 1302 symval->size = es->st_size; 1303 return (0); 1304 } 1305 if (ef->symtab == ef->ddbsymtab) 1306 return (ENOENT); 1307 if (es >= ef->ddbsymtab && es < (ef->ddbsymtab + ef->ddbsymcnt)) { 1308 symval->name = ef->ddbstrtab + es->st_name; 1309 symval->value = (caddr_t) ef->address + es->st_value; 1310 symval->size = es->st_size; 1311 return (0); 1312 } 1313 return (ENOENT); 1314 } 1315 1316 static int 1317 link_elf_search_symbol(linker_file_t lf, caddr_t value, 1318 c_linker_sym_t *sym, long *diffp) 1319 { 1320 elf_file_t ef = (elf_file_t) lf; 1321 u_long off = (uintptr_t) (void *) value; 1322 u_long diff = off; 1323 u_long st_value; 1324 const Elf_Sym* es; 1325 const Elf_Sym* best = 0; 1326 int i; 1327 1328 for (i = 0, es = ef->ddbsymtab; i < ef->ddbsymcnt; i++, es++) { 1329 if (es->st_name == 0) 1330 continue; 1331 st_value = es->st_value + (uintptr_t) (void *) ef->address; 1332 if (off >= st_value) { 1333 if (off - st_value < diff) { 1334 diff = off - st_value; 1335 best = es; 1336 if (diff == 0) 1337 break; 1338 } else if (off - st_value == diff) { 1339 best = es; 1340 } 1341 } 1342 } 1343 if (best == 0) 1344 *diffp = off; 1345 else 1346 *diffp = diff; 1347 *sym = (c_linker_sym_t) best; 1348 1349 return (0); 1350 } 1351 1352 /* 1353 * Look up a linker set on an ELF system. 1354 */ 1355 static int 1356 link_elf_lookup_set(linker_file_t lf, const char *name, 1357 void ***startp, void ***stopp, int *countp) 1358 { 1359 c_linker_sym_t sym; 1360 linker_symval_t symval; 1361 char *setsym; 1362 void **start, **stop; 1363 int len, error = 0, count; 1364 1365 len = strlen(name) + sizeof("__start_set_"); /* sizeof includes \0 */ 1366 setsym = malloc(len, M_LINKER, M_WAITOK); 1367 1368 /* get address of first entry */ 1369 snprintf(setsym, len, "%s%s", "__start_set_", name); 1370 error = link_elf_lookup_symbol(lf, setsym, &sym); 1371 if (error != 0) 1372 goto out; 1373 link_elf_symbol_values(lf, sym, &symval); 1374 if (symval.value == 0) { 1375 error = ESRCH; 1376 goto out; 1377 } 1378 start = (void **)symval.value; 1379 1380 /* get address of last entry */ 1381 snprintf(setsym, len, "%s%s", "__stop_set_", name); 1382 error = link_elf_lookup_symbol(lf, setsym, &sym); 1383 if (error != 0) 1384 goto out; 1385 link_elf_symbol_values(lf, sym, &symval); 1386 if (symval.value == 0) { 1387 error = ESRCH; 1388 goto out; 1389 } 1390 stop = (void **)symval.value; 1391 1392 /* and the number of entries */ 1393 count = stop - start; 1394 1395 /* and copy out */ 1396 if (startp != NULL) 1397 *startp = start; 1398 if (stopp != NULL) 1399 *stopp = stop; 1400 if (countp != NULL) 1401 *countp = count; 1402 1403 out: 1404 free(setsym, M_LINKER); 1405 return (error); 1406 } 1407 1408 static int 1409 link_elf_each_function_name(linker_file_t file, 1410 int (*callback)(const char *, void *), void *opaque) 1411 { 1412 elf_file_t ef = (elf_file_t)file; 1413 const Elf_Sym *symp; 1414 int i, error; 1415 1416 /* Exhaustive search */ 1417 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) { 1418 if (symp->st_value != 0 && 1419 ELF_ST_TYPE(symp->st_info) == STT_FUNC) { 1420 error = callback(ef->ddbstrtab + symp->st_name, opaque); 1421 if (error != 0) 1422 return (error); 1423 } 1424 } 1425 return (0); 1426 } 1427 1428 static int 1429 link_elf_each_function_nameval(linker_file_t file, 1430 linker_function_nameval_callback_t callback, void *opaque) 1431 { 1432 linker_symval_t symval; 1433 elf_file_t ef = (elf_file_t)file; 1434 const Elf_Sym* symp; 1435 int i, error; 1436 1437 /* Exhaustive search */ 1438 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) { 1439 if (symp->st_value != 0 && 1440 ELF_ST_TYPE(symp->st_info) == STT_FUNC) { 1441 error = link_elf_symbol_values(file, 1442 (c_linker_sym_t) symp, &symval); 1443 if (error != 0) 1444 return (error); 1445 error = callback(file, i, &symval, opaque); 1446 if (error != 0) 1447 return (error); 1448 } 1449 } 1450 return (0); 1451 } 1452 1453 const Elf_Sym * 1454 elf_get_sym(linker_file_t lf, Elf_Size symidx) 1455 { 1456 elf_file_t ef = (elf_file_t)lf; 1457 1458 if (symidx >= ef->nchains) 1459 return (NULL); 1460 return (ef->symtab + symidx); 1461 } 1462 1463 const char * 1464 elf_get_symname(linker_file_t lf, Elf_Size symidx) 1465 { 1466 elf_file_t ef = (elf_file_t)lf; 1467 const Elf_Sym *sym; 1468 1469 if (symidx >= ef->nchains) 1470 return (NULL); 1471 sym = ef->symtab + symidx; 1472 return (ef->strtab + sym->st_name); 1473 } 1474 1475 /* 1476 * Symbol lookup function that can be used when the symbol index is known (ie 1477 * in relocations). It uses the symbol index instead of doing a fully fledged 1478 * hash table based lookup when such is valid. For example for local symbols. 1479 * This is not only more efficient, it's also more correct. It's not always 1480 * the case that the symbol can be found through the hash table. 1481 */ 1482 static Elf_Addr 1483 elf_lookup(linker_file_t lf, Elf_Size symidx, int deps) 1484 { 1485 elf_file_t ef = (elf_file_t)lf; 1486 const Elf_Sym *sym; 1487 const char *symbol; 1488 Elf_Addr addr, start, base; 1489 1490 /* Don't even try to lookup the symbol if the index is bogus. */ 1491 if (symidx >= ef->nchains) 1492 return (0); 1493 1494 sym = ef->symtab + symidx; 1495 1496 /* 1497 * Don't do a full lookup when the symbol is local. It may even 1498 * fail because it may not be found through the hash table. 1499 */ 1500 if (ELF_ST_BIND(sym->st_info) == STB_LOCAL) { 1501 /* Force lookup failure when we have an insanity. */ 1502 if (sym->st_shndx == SHN_UNDEF || sym->st_value == 0) 1503 return (0); 1504 return ((Elf_Addr)ef->address + sym->st_value); 1505 } 1506 1507 /* 1508 * XXX we can avoid doing a hash table based lookup for global 1509 * symbols as well. This however is not always valid, so we'll 1510 * just do it the hard way for now. Performance tweaks can 1511 * always be added. 1512 */ 1513 1514 symbol = ef->strtab + sym->st_name; 1515 1516 /* Force a lookup failure if the symbol name is bogus. */ 1517 if (*symbol == 0) 1518 return (0); 1519 1520 addr = ((Elf_Addr)linker_file_lookup_symbol(lf, symbol, deps)); 1521 1522 if (elf_set_find(&set_pcpu_list, addr, &start, &base)) 1523 addr = addr - start + base; 1524 #ifdef VIMAGE 1525 else if (elf_set_find(&set_vnet_list, addr, &start, &base)) 1526 addr = addr - start + base; 1527 #endif 1528 return addr; 1529 } 1530 1531 static void 1532 link_elf_reloc_local(linker_file_t lf) 1533 { 1534 const Elf_Rel *rellim; 1535 const Elf_Rel *rel; 1536 const Elf_Rela *relalim; 1537 const Elf_Rela *rela; 1538 elf_file_t ef = (elf_file_t)lf; 1539 1540 /* Perform relocations without addend if there are any: */ 1541 if ((rel = ef->rel) != NULL) { 1542 rellim = (const Elf_Rel *)((const char *)ef->rel + ef->relsize); 1543 while (rel < rellim) { 1544 elf_reloc_local(lf, (Elf_Addr)ef->address, rel, 1545 ELF_RELOC_REL, elf_lookup); 1546 rel++; 1547 } 1548 } 1549 1550 /* Perform relocations with addend if there are any: */ 1551 if ((rela = ef->rela) != NULL) { 1552 relalim = (const Elf_Rela *) 1553 ((const char *)ef->rela + ef->relasize); 1554 while (rela < relalim) { 1555 elf_reloc_local(lf, (Elf_Addr)ef->address, rela, 1556 ELF_RELOC_RELA, elf_lookup); 1557 rela++; 1558 } 1559 } 1560 } 1561 1562 static long 1563 link_elf_symtab_get(linker_file_t lf, const Elf_Sym **symtab) 1564 { 1565 elf_file_t ef = (elf_file_t)lf; 1566 1567 *symtab = ef->ddbsymtab; 1568 1569 if (*symtab == NULL) 1570 return (0); 1571 1572 return (ef->ddbsymcnt); 1573 } 1574 1575 static long 1576 link_elf_strtab_get(linker_file_t lf, caddr_t *strtab) 1577 { 1578 elf_file_t ef = (elf_file_t)lf; 1579 1580 *strtab = ef->ddbstrtab; 1581 1582 if (*strtab == NULL) 1583 return (0); 1584 1585 return (ef->ddbstrcnt); 1586 } 1587