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