reloc.c revision 1.24
1 /* $NetBSD: reloc.c,v 1.24 1999/12/08 08:47:10 itohy Exp $ */ 2 3 /* 4 * Copyright 1996 John D. Polstra. 5 * Copyright 1996 Matt Thomas <matt (at) 3am-software.com> 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by John Polstra. 19 * 4. The name of the author may not be used to endorse or promote products 20 * derived from this software without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 23 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 24 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 25 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 26 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 27 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 28 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 29 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 30 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 31 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 32 */ 33 34 /* 35 * Dynamic linker for ELF. 36 * 37 * John Polstra <jdp (at) polstra.com>. 38 */ 39 40 #include <err.h> 41 #include <errno.h> 42 #include <fcntl.h> 43 #include <stdarg.h> 44 #include <stdio.h> 45 #include <stdlib.h> 46 #include <string.h> 47 #include <unistd.h> 48 #include <sys/types.h> 49 #include <sys/mman.h> 50 #include <dirent.h> 51 52 #include "debug.h" 53 #include "rtld.h" 54 55 #ifndef RTLD_INHIBIT_COPY_RELOCS 56 static int _rtld_do_copy_relocation __P((const Obj_Entry *, const Elf_RelA *, 57 bool)); 58 59 /* 60 * XXX: These don't work for the alpha and i386; don't know about powerpc 61 * The alpha and the i386 avoid the problem by compiling everything PIC. 62 * These relocation are supposed to be writing the address of the 63 * function to be called on the bss.rel or bss.rela segment, but: 64 * - st_size == 0 65 * - on the i386 at least the call instruction is a direct call 66 * not an indirect call. 67 */ 68 static int 69 _rtld_do_copy_relocation(dstobj, rela, dodebug) 70 const Obj_Entry *dstobj; 71 const Elf_RelA *rela; 72 bool dodebug; 73 { 74 void *dstaddr = (void *)(dstobj->relocbase + rela->r_offset); 75 const Elf_Sym *dstsym = dstobj->symtab + ELF_R_SYM(rela->r_info); 76 const char *name = dstobj->strtab + dstsym->st_name; 77 unsigned long hash = _rtld_elf_hash(name); 78 size_t size = dstsym->st_size; 79 const void *srcaddr; 80 const Elf_Sym *srcsym; 81 Obj_Entry *srcobj; 82 83 for (srcobj = dstobj->next; srcobj != NULL; srcobj = srcobj->next) 84 if ((srcsym = _rtld_symlook_obj(name, hash, srcobj, 85 false)) != NULL) 86 break; 87 88 if (srcobj == NULL) { 89 _rtld_error("Undefined symbol \"%s\" referenced from COPY" 90 " relocation in %s", name, dstobj->path); 91 return (-1); 92 } 93 srcaddr = (const void *)(srcobj->relocbase + srcsym->st_value); 94 (void)memcpy(dstaddr, srcaddr, size); 95 rdbg(dodebug, ("COPY %s %s %s --> src=%p dst=%p *dst= %p size %ld", 96 dstobj->path, srcobj->path, name, (void *)srcaddr, 97 (void *)dstaddr, (void *)*(long *)dstaddr, (long)size)); 98 return (0); 99 } 100 #endif /* RTLD_INHIBIT_COPY_RELOCS */ 101 102 103 /* 104 * Process the special R_xxx_COPY relocations in the main program. These 105 * copy data from a shared object into a region in the main program's BSS 106 * segment. 107 * 108 * Returns 0 on success, -1 on failure. 109 */ 110 int 111 _rtld_do_copy_relocations(dstobj, dodebug) 112 const Obj_Entry *dstobj; 113 bool dodebug; 114 { 115 #ifndef RTLD_INHIBIT_COPY_RELOCS 116 117 /* COPY relocations are invalid elsewhere */ 118 assert(dstobj->mainprog); 119 120 if (dstobj->rel != NULL) { 121 const Elf_Rel *rel; 122 for (rel = dstobj->rel; rel < dstobj->rellim; ++rel) { 123 if (ELF_R_TYPE(rel->r_info) == R_TYPE(COPY)) { 124 Elf_RelA ourrela; 125 ourrela.r_info = rel->r_info; 126 ourrela.r_offset = rel->r_offset; 127 ourrela.r_addend = 0; 128 if (_rtld_do_copy_relocation(dstobj, 129 &ourrela, dodebug) < 0) 130 return (-1); 131 } 132 } 133 } 134 if (dstobj->rela != NULL) { 135 const Elf_RelA *rela; 136 for (rela = dstobj->rela; rela < dstobj->relalim; ++rela) { 137 if (ELF_R_TYPE(rela->r_info) == R_TYPE(COPY)) { 138 if (_rtld_do_copy_relocation(dstobj, rela, 139 dodebug) < 0) 140 return (-1); 141 } 142 } 143 } 144 #endif /* RTLD_INHIBIT_COPY_RELOCS */ 145 146 return (0); 147 } 148 149 150 #ifndef __sparc__ 151 int 152 _rtld_relocate_nonplt_object(obj, rela, dodebug) 153 Obj_Entry *obj; 154 const Elf_RelA *rela; 155 bool dodebug; 156 { 157 Elf_Addr *where = (Elf_Addr *)(obj->relocbase + rela->r_offset); 158 const Elf_Sym *def; 159 const Obj_Entry *defobj; 160 #if defined(__alpha__) || defined(__i386__) || defined(__m68k__) 161 extern Elf_Addr _GLOBAL_OFFSET_TABLE_[]; 162 extern Elf_Dyn _DYNAMIC; 163 #endif 164 #if defined(__alpha__) || defined(__i386__) || defined(__m68k__) || \ 165 defined(__powerpc__) || defined(__vax__) 166 Elf_Addr tmp; 167 #endif 168 169 switch (ELF_R_TYPE(rela->r_info)) { 170 171 case R_TYPE(NONE): 172 break; 173 174 #if defined(__i386__) 175 case R_TYPE(GOT32): 176 177 def = _rtld_find_symdef(_rtld_objlist, rela->r_info, NULL, obj, 178 &defobj, false); 179 if (def == NULL) 180 return -1; 181 182 tmp = (Elf_Addr)(defobj->relocbase + def->st_value); 183 if (*where != tmp) 184 *where = tmp; 185 rdbg(dodebug, ("GOT32 %s in %s --> %p in %s", 186 defobj->strtab + def->st_name, obj->path, 187 (void *)*where, defobj->path)); 188 break; 189 190 case R_TYPE(PC32): 191 /* 192 * I don't think the dynamic linker should ever see this 193 * type of relocation. But the binutils-2.6 tools sometimes 194 * generate it. 195 */ 196 197 def = _rtld_find_symdef(_rtld_objlist, rela->r_info, NULL, obj, 198 &defobj, false); 199 if (def == NULL) 200 return -1; 201 202 *where += (Elf_Addr)(defobj->relocbase + def->st_value) - 203 (Elf_Addr)where; 204 rdbg(dodebug, ("PC32 %s in %s --> %p in %s", 205 defobj->strtab + def->st_name, obj->path, 206 (void *)*where, defobj->path)); 207 break; 208 209 case R_TYPE(32): 210 def = _rtld_find_symdef(_rtld_objlist, rela->r_info, NULL, obj, 211 &defobj, false); 212 if (def == NULL) 213 return -1; 214 215 *where += (Elf_Addr)(defobj->relocbase + def->st_value); 216 rdbg(dodebug, ("32 %s in %s --> %p in %s", 217 defobj->strtab + def->st_name, obj->path, 218 (void *)*where, defobj->path)); 219 break; 220 #endif /* __i386__ */ 221 222 #if defined(__m68k__) 223 case R_TYPE(GOT32): 224 def = _rtld_find_symdef(_rtld_objlist, rela->r_info, NULL, obj, 225 &defobj, false); 226 if (def == NULL) 227 return -1; 228 229 tmp = (Elf_Addr)(defobj->relocbase + def->st_value + 230 rela->r_addend); 231 if (*where != tmp) 232 *where = tmp; 233 rdbg(dodebug, ("GOT32 %s in %s --> %p in %s", 234 defobj->strtab + def->st_name, obj->path, 235 (void *)*where, defobj->path)); 236 break; 237 238 case R_TYPE(PC32): 239 def = _rtld_find_symdef(_rtld_objlist, rela->r_info, NULL, obj, 240 &defobj, false); 241 if (def == NULL) 242 return -1; 243 244 tmp = (Elf_Addr)(defobj->relocbase + def->st_value + 245 rela->r_addend) - (Elf_Addr)where; 246 if (*where != tmp) 247 *where = tmp; 248 rdbg(dodebug, ("PC32 %s in %s --> %p in %s", 249 defobj->strtab + def->st_name, obj->path, 250 (void *)*where, defobj->path)); 251 break; 252 253 case R_TYPE(32): 254 def = _rtld_find_symdef(_rtld_objlist, rela->r_info, NULL, obj, 255 &defobj, false); 256 if (def == NULL) 257 return -1; 258 259 tmp = (Elf_Addr)(defobj->relocbase + def->st_value + 260 rela->r_addend); 261 if (*where != tmp) 262 *where = tmp; 263 rdbg(dodebug, ("32 %s in %s --> %p in %s", 264 defobj->strtab + def->st_name, obj->path, 265 (void *)*where, defobj->path)); 266 break; 267 #endif /* __m68k__ */ 268 269 #if defined(__alpha__) 270 case R_TYPE(REFQUAD): 271 def = _rtld_find_symdef(_rtld_objlist, rela->r_info, NULL, obj, 272 &defobj, false); 273 if (def == NULL) 274 return -1; 275 276 tmp = (Elf_Addr)(defobj->relocbase + def->st_value) + 277 *where + rela->r_addend; 278 if (*where != tmp) 279 *where = tmp; 280 rdbg(dodebug, ("REFQUAD %s in %s --> %p in %s", 281 defobj->strtab + def->st_name, obj->path, 282 (void *)*where, defobj->path)); 283 break; 284 #endif /* __alpha__ */ 285 286 #if defined(__alpha__) || defined(__i386__) || defined(__m68k__) 287 case R_TYPE(GLOB_DAT): 288 def = _rtld_find_symdef(_rtld_objlist, rela->r_info, NULL, obj, 289 &defobj, false); 290 if (def == NULL) 291 return -1; 292 293 if (*where != (Elf_Addr)(defobj->relocbase + def->st_value)) 294 *where = (Elf_Addr)(defobj->relocbase + def->st_value); 295 rdbg(dodebug, ("GLOB_DAT %s in %s --> %p in %s", 296 defobj->strtab + def->st_name, obj->path, 297 (void *)*where, defobj->path)); 298 break; 299 300 case R_TYPE(RELATIVE): 301 if (!dodebug || 302 (caddr_t)where < (caddr_t)_GLOBAL_OFFSET_TABLE_ || 303 (caddr_t)where >= (caddr_t)&_DYNAMIC) { 304 *where += (Elf_Addr)obj->relocbase; 305 rdbg(dodebug, ("RELATIVE in %s --> %p", obj->path, 306 (void *)*where)); 307 } 308 else 309 rdbg(dodebug, ("RELATIVE in %s stays at %p", 310 obj->path, (void *)*where)); 311 break; 312 313 case R_TYPE(COPY): 314 /* 315 * These are deferred until all other relocations have 316 * been done. All we do here is make sure that the COPY 317 * relocation is not in a shared library. They are allowed 318 * only in executable files. 319 */ 320 if (!obj->mainprog) { 321 _rtld_error( 322 "%s: Unexpected R_COPY relocation in shared library", 323 obj->path); 324 return -1; 325 } 326 rdbg(dodebug, ("COPY (avoid in main)")); 327 break; 328 #endif /* __i386__ || __alpha__ */ 329 330 #if defined(__mips__) 331 case R_TYPE(REL32): 332 /* 32-bit PC-relative reference */ 333 def = obj->symtab + ELF_R_SYM(rela->r_info); 334 335 if (ELFDEFNNAME(ST_BIND)(def->st_info) == STB_LOCAL && 336 (ELFDEFNNAME(ST_TYPE)(def->st_info) == STT_SECTION || 337 ELFDEFNNAME(ST_TYPE)(def->st_info) == STT_NOTYPE)) { 338 *where += (Elf_Addr)obj->relocbase; 339 rdbg(dodebug, ("REL32 in %s --> %p", obj->path, 340 (void *)*where)); 341 } else { 342 /* XXX maybe do something re: bootstrapping? */ 343 def = _rtld_find_symdef(_rtld_objlist, rela->r_info, 344 NULL, obj, &defobj, false); 345 if (def == NULL) 346 return -1; 347 *where += (Elf_Addr)(defobj->relocbase + def->st_value); 348 rdbg(dodebug, ("REL32 %s in %s --> %p in %s", 349 defobj->strtab + def->st_name, obj->path, 350 (void *)*where, defobj->path)); 351 } 352 break; 353 354 #endif /* __mips__ */ 355 356 #if defined(__powerpc__) || defined(__vax__) 357 case R_TYPE(32): /* word32 S + A */ 358 case R_TYPE(GLOB_DAT): /* word32 S + A */ 359 def = _rtld_find_symdef(_rtld_objlist, rela->r_info, NULL, obj, 360 &defobj, false); 361 if (def == NULL) 362 return -1; 363 364 tmp = (Elf_Addr)(defobj->relocbase + def->st_value + 365 rela->r_addend); 366 367 if (*where != tmp) 368 *where = tmp; 369 rdbg(dodebug, ("32/GLOB_DAT %s in %s --> %p in %s", 370 defobj->strtab + def->st_name, obj->path, 371 (void *)*where, defobj->path)); 372 break; 373 374 case R_TYPE(COPY): 375 rdbg(dodebug, ("COPY")); 376 break; 377 378 case R_TYPE(JMP_SLOT): 379 rdbg(dodebug, ("JMP_SLOT")); 380 break; 381 382 case R_TYPE(RELATIVE): /* word32 B + A */ 383 tmp = (Elf_Addr)(obj->relocbase + rela->r_addend); 384 if (*where != tmp) 385 *where = tmp; 386 rdbg(dodebug, ("RELATIVE in %s --> %p", obj->path, 387 (void *)*where)); 388 break; 389 #endif /* __powerpc__ || __vax__ */ 390 391 #if defined(__vax__) 392 case R_TYPE(REL32): 393 def = _rtld_find_symdef(_rtld_objlist, rela->r_info, NULL, obj, 394 &defobj, false); 395 if (def == NULL) 396 return -1; 397 398 *where += (Elf_Addr)(defobj->relocbase + def->st_value 399 + rela->r_addend); 400 rdbg(dodebug, ("32 %s in %s --> %p in %s", 401 defobj->strtab + def->st_name, obj->path, 402 (void *)*where, defobj->path)); 403 break; 404 #endif /* __vax__ */ 405 406 default: 407 def = _rtld_find_symdef(_rtld_objlist, rela->r_info, NULL, obj, 408 &defobj, true); 409 rdbg(dodebug, ("sym = %lu, type = %lu, offset = %p, " 410 "addend = %p, contents = %p, symbol = %s", 411 (u_long)ELF_R_SYM(rela->r_info), 412 (u_long)ELF_R_TYPE(rela->r_info), 413 (void *)rela->r_offset, (void *)rela->r_addend, 414 (void *)*where, 415 def ? defobj->strtab + def->st_name : "??")); 416 _rtld_error("%s: Unsupported relocation type %d" 417 "in non-PLT relocations\n", 418 obj->path, ELF_R_TYPE(rela->r_info)); 419 return -1; 420 } 421 return 0; 422 } 423 424 425 426 int 427 _rtld_relocate_plt_object(obj, rela, addrp, bind_now, dodebug) 428 Obj_Entry *obj; 429 const Elf_RelA *rela; 430 caddr_t *addrp; 431 bool bind_now; 432 bool dodebug; 433 { 434 Elf_Addr *where = (Elf_Addr *)(obj->relocbase + rela->r_offset); 435 Elf_Addr new_value; 436 437 /* Fully resolve procedure addresses now */ 438 439 #if defined(__powerpc__) 440 return _rtld_reloc_powerpc_plt(obj, rela, bind_now); 441 #endif 442 443 #if defined(__alpha__) || defined(__i386__) || defined(__m68k__) || \ 444 defined(__vax__) 445 if (bind_now || obj->pltgot == NULL) { 446 const Elf_Sym *def; 447 const Obj_Entry *defobj; 448 449 assert(ELF_R_TYPE(rela->r_info) == R_TYPE(JMP_SLOT)); 450 451 def = _rtld_find_symdef(_rtld_objlist, rela->r_info, NULL, obj, 452 &defobj, true); 453 if (def == NULL) 454 return -1; 455 456 new_value = (Elf_Addr)(defobj->relocbase + def->st_value); 457 rdbg(dodebug, ("bind now %d/fixup in %s --> old=%p new=%p", 458 (int)bind_now, 459 defobj->strtab + def->st_name, 460 (void *)*where, (void *)new_value)); 461 } else 462 #endif /* __alpha__ || __i386__ || __m68k__ || __vax__ */ 463 if (!obj->mainprog) { 464 /* Just relocate the GOT slots pointing into the PLT */ 465 new_value = *where + (Elf_Addr)(obj->relocbase); 466 rdbg(dodebug, ("fixup !main in %s --> %p", obj->path, 467 (void *)*where)); 468 } else { 469 return 0; 470 } 471 /* 472 * Since this page is probably copy-on-write, let's not write 473 * it unless we really really have to. 474 */ 475 if (*where != new_value) 476 *where = new_value; 477 if (addrp != NULL) 478 *addrp = *(caddr_t *)(obj->relocbase + rela->r_offset); 479 return 0; 480 } 481 #endif /* __sparc__ */ 482 483 caddr_t 484 _rtld_bind(obj, reloff) 485 Obj_Entry *obj; 486 Elf_Word reloff; 487 { 488 const Elf_RelA *rela; 489 Elf_RelA ourrela; 490 caddr_t addr; 491 492 if (obj->pltrel != NULL) { 493 const Elf_Rel *rel; 494 495 rel = (const Elf_Rel *)((caddr_t) obj->pltrel + reloff); 496 ourrela.r_info = rel->r_info; 497 ourrela.r_offset = rel->r_offset; 498 rela = &ourrela; 499 } else { 500 rela = (const Elf_RelA *)((caddr_t) obj->pltrela + reloff); 501 } 502 503 if (_rtld_relocate_plt_object(obj, rela, &addr, true, true) < 0) 504 _rtld_die(); 505 506 return addr; 507 } 508 509 /* 510 * Relocate newly-loaded shared objects. The argument is a pointer to 511 * the Obj_Entry for the first such object. All objects from the first 512 * to the end of the list of objects are relocated. Returns 0 on success, 513 * or -1 on failure. 514 */ 515 int 516 _rtld_relocate_objects(first, bind_now, dodebug) 517 Obj_Entry *first; 518 bool bind_now; 519 bool dodebug; 520 { 521 Obj_Entry *obj; 522 int ok = 1; 523 524 for (obj = first; obj != NULL; obj = obj->next) { 525 if (obj->nbuckets == 0 || obj->nchains == 0 || 526 obj->buckets == NULL || obj->symtab == NULL || 527 obj->strtab == NULL) { 528 _rtld_error("%s: Shared object has no run-time" 529 " symbol table", obj->path); 530 return -1; 531 } 532 rdbg(dodebug, (" relocating %s (%ld/%ld rel/rela, " 533 "%ld/%ld plt rel/rela)", 534 obj->path, 535 (long)(obj->rellim - obj->rel), 536 (long)(obj->relalim - obj->rela), 537 (long)(obj->pltrellim - obj->pltrel), 538 (long)(obj->pltrelalim - obj->pltrela))); 539 540 if (obj->textrel) { 541 /* 542 * There are relocations to the write-protected text 543 * segment. 544 */ 545 if (mprotect(obj->mapbase, obj->textsize, 546 PROT_READ | PROT_WRITE | PROT_EXEC) == -1) { 547 _rtld_error("%s: Cannot write-enable text " 548 "segment: %s", obj->path, xstrerror(errno)); 549 return -1; 550 } 551 } 552 if (obj->rel != NULL) { 553 /* Process the non-PLT relocations. */ 554 const Elf_Rel *rel; 555 for (rel = obj->rel; rel < obj->rellim; ++rel) { 556 Elf_RelA ourrela; 557 ourrela.r_info = rel->r_info; 558 ourrela.r_offset = rel->r_offset; 559 #if defined(__mips__) 560 /* rel->r_offset is not valid on mips? */ 561 if (ELF_R_TYPE(ourrela.r_info) == R_TYPE(NONE)) 562 ourrela.r_addend = 0; 563 else 564 #endif 565 ourrela.r_addend = 566 *(Elf_Word *)(obj->relocbase + 567 rel->r_offset); 568 569 if (_rtld_relocate_nonplt_object(obj, &ourrela, 570 dodebug) < 0) 571 ok = 0; 572 } 573 } 574 if (obj->rela != NULL) { 575 /* Process the non-PLT relocations. */ 576 const Elf_RelA *rela; 577 for (rela = obj->rela; rela < obj->relalim; ++rela) { 578 if (_rtld_relocate_nonplt_object(obj, rela, 579 dodebug) < 0) 580 ok = 0; 581 } 582 } 583 if (obj->textrel) { /* Re-protected the text segment. */ 584 if (mprotect(obj->mapbase, obj->textsize, 585 PROT_READ | PROT_EXEC) == -1) { 586 _rtld_error("%s: Cannot write-protect text " 587 "segment: %s", obj->path, xstrerror(errno)); 588 return -1; 589 } 590 } 591 /* Process the PLT relocations. */ 592 if (obj->pltrel != NULL) { 593 const Elf_Rel *rel; 594 for (rel = obj->pltrel; rel < obj->pltrellim; ++rel) { 595 Elf_RelA ourrela; 596 ourrela.r_info = rel->r_info; 597 ourrela.r_offset = rel->r_offset; 598 ourrela.r_addend = 599 *(Elf_Word *)(obj->relocbase + 600 rel->r_offset); 601 if (_rtld_relocate_plt_object(obj, &ourrela, 602 NULL, bind_now, dodebug) < 0) 603 ok = 0; 604 } 605 } 606 if (obj->pltrela != NULL) { 607 const Elf_RelA *rela; 608 for (rela = obj->pltrela; rela < obj->pltrelalim; 609 ++rela) { 610 if (_rtld_relocate_plt_object(obj, rela, 611 NULL, bind_now, dodebug) < 0) 612 ok = 0; 613 } 614 } 615 if (!ok) 616 return -1; 617 618 619 /* Set some sanity-checking numbers in the Obj_Entry. */ 620 obj->magic = RTLD_MAGIC; 621 obj->version = RTLD_VERSION; 622 623 /* Fill in the dynamic linker entry points. */ 624 obj->dlopen = _rtld_dlopen; 625 obj->dlsym = _rtld_dlsym; 626 obj->dlerror = _rtld_dlerror; 627 obj->dlclose = _rtld_dlclose; 628 629 /* Set the special PLTGOT entries. */ 630 if (obj->pltgot != NULL) { 631 #if defined(__i386__) || defined(__m68k__) 632 obj->pltgot[1] = (Elf_Addr) obj; 633 obj->pltgot[2] = (Elf_Addr) & _rtld_bind_start; 634 #endif 635 #if defined(__alpha__) 636 /* 637 * This function will be called to perform the 638 * relocation. 639 */ 640 obj->pltgot[2] = (Elf_Addr) & _rtld_bind_start; 641 /* Identify this shared object */ 642 obj->pltgot[3] = (Elf_Addr) obj; 643 #endif 644 #if defined(__mips__) 645 _rtld_relocate_mips_got(obj); 646 647 obj->pltgot[0] = (Elf_Addr) & _rtld_bind_start; 648 /* XXX only if obj->pltgot[1] & 0x80000000 ?? */ 649 obj->pltgot[1] |= (Elf_Addr) obj; 650 #endif 651 #if defined(__powerpc__) 652 _rtld_setup_powerpc_plt(obj); 653 #endif 654 #if defined(__sparc__) 655 /* 656 * PLTGOT is the PLT on the sparc. 657 * The first entry holds the call the dynamic linker. 658 * We construct a `call' sequence that transfers 659 * to `_rtld_bind_start()'. 660 * The second entry holds the object identification. 661 * Note: each PLT entry is three words long. 662 */ 663 #define SAVE 0x9de3bfc0 /* i.e. `save %sp,-64,%sp' */ 664 #define CALL 0x40000000 665 #define NOP 0x01000000 666 obj->pltgot[0] = SAVE; 667 obj->pltgot[1] = CALL | 668 ((Elf_Addr)&_rtld_bind_start - 669 (Elf_Addr)&obj->pltgot[1]) >> 2; 670 obj->pltgot[2] = NOP; 671 672 obj->pltgot[3] = (Elf_Addr) obj; 673 #endif 674 #if defined(__vax__) 675 obj->pltgot[0] = (Elf_Addr) & _rtld_bind_start; 676 obj->pltgot[1] = (Elf_Addr) obj; 677 #endif 678 } 679 } 680 681 return 0; 682 } 683
Indexes created Tue Sep 30 07:10:03 GMT 2025