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