1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 22 /* 23 * Copyright (c) 2004, 2010, Oracle and/or its affiliates. All rights reserved. 24 */ 25 26 /* Get the x86 version of the relocation engine */ 27 #define DO_RELOC_LIBLD_X86 28 29 #include <string.h> 30 #include <stdio.h> 31 #include <strings.h> 32 #include <sys/elf_amd64.h> 33 #include <debug.h> 34 #include <reloc.h> 35 #include <i386/machdep_x86.h> 36 #include "msg.h" 37 #include "_libld.h" 38 39 /* 40 * This module uses do_reloc_ld() to execute several synthesized relocations. 41 * That function expects to be passed two things that we need to construct 42 * here: 43 * 44 * 1) A Rel_desc descriptor for each relocation type, from which the 45 * rel_rtype field, and nothing else, is obtained. This is easily 46 * handled by constructing the necessary descriptors. 47 * 48 * 2) A function, which called with the Rel_desc descriptor, returns 49 * a string representing the name of the symbol associated with 50 * the descriptor. The usual function for this is ld_reloc_sym_name(). 51 * However, that function will not work in this case, as these synthetic 52 * relocations do not have an associated symbol. We supply the 53 * syn_rdesc_sym_name() function to simply return the fixed name. 54 */ 55 static Rel_desc rdesc_r_amd64_gotpcrel = { 56 NULL, NULL, NULL, 0, 0, 0, R_AMD64_GOTPCREL }; 57 static Rel_desc rdesc_r_amd64_32 = { 58 NULL, NULL, NULL, 0, 0, 0, R_AMD64_32 }; 59 static Rel_desc rdesc_r_amd64_pc32 = { 60 NULL, NULL, NULL, 0, 0, 0, R_AMD64_PC32 }; 61 62 /*ARGSUSED*/ 63 static const char * 64 syn_rdesc_sym_name(Rel_desc *rdesc) 65 { 66 return (MSG_ORIG(MSG_SYM_PLTENT)); 67 } 68 69 /* 70 * Search the GOT index list for a GOT entry with a matching reference and the 71 * proper addend. 72 */ 73 static Gotndx * 74 ld_find_got_ndx(Alist *alp, Gotref gref, Ofl_desc *ofl, Rel_desc *rdesc) 75 { 76 Aliste idx; 77 Gotndx *gnp; 78 79 assert(rdesc != 0); 80 81 if ((gref == GOT_REF_TLSLD) && ofl->ofl_tlsldgotndx) 82 return (ofl->ofl_tlsldgotndx); 83 84 for (ALIST_TRAVERSE(alp, idx, gnp)) { 85 if ((rdesc->rel_raddend == gnp->gn_addend) && 86 (gnp->gn_gotref == gref)) { 87 return (gnp); 88 } 89 } 90 return (NULL); 91 } 92 93 static Xword 94 ld_calc_got_offset(Rel_desc *rdesc, Ofl_desc *ofl) 95 { 96 Os_desc *osp = ofl->ofl_osgot; 97 Sym_desc *sdp = rdesc->rel_sym; 98 Xword gotndx; 99 Gotref gref; 100 Gotndx *gnp; 101 102 if (rdesc->rel_flags & FLG_REL_DTLS) 103 gref = GOT_REF_TLSGD; 104 else if (rdesc->rel_flags & FLG_REL_MTLS) 105 gref = GOT_REF_TLSLD; 106 else if (rdesc->rel_flags & FLG_REL_STLS) 107 gref = GOT_REF_TLSIE; 108 else 109 gref = GOT_REF_GENERIC; 110 111 gnp = ld_find_got_ndx(sdp->sd_GOTndxs, gref, ofl, rdesc); 112 assert(gnp); 113 114 gotndx = (Xword)gnp->gn_gotndx; 115 116 if ((rdesc->rel_flags & FLG_REL_DTLS) && 117 (rdesc->rel_rtype == R_AMD64_DTPOFF64)) 118 gotndx++; 119 120 return ((Xword)(osp->os_shdr->sh_addr + (gotndx * M_GOT_ENTSIZE))); 121 } 122 123 static Word 124 ld_init_rel(Rel_desc *reld, Word *typedata, void *reloc) 125 { 126 Rela *rel = (Rela *)reloc; 127 128 /* LINTED */ 129 reld->rel_rtype = (Word)ELF_R_TYPE(rel->r_info, M_MACH); 130 reld->rel_roffset = rel->r_offset; 131 reld->rel_raddend = rel->r_addend; 132 *typedata = 0; 133 134 reld->rel_flags |= FLG_REL_RELA; 135 136 return ((Word)ELF_R_SYM(rel->r_info)); 137 } 138 139 static void 140 ld_mach_eflags(Ehdr *ehdr, Ofl_desc *ofl) 141 { 142 ofl->ofl_dehdr->e_flags |= ehdr->e_flags; 143 } 144 145 static void 146 ld_mach_make_dynamic(Ofl_desc *ofl, size_t *cnt) 147 { 148 if (!(ofl->ofl_flags & FLG_OF_RELOBJ)) { 149 /* 150 * Create this entry if we are going to create a PLT table. 151 */ 152 if (ofl->ofl_pltcnt) 153 (*cnt)++; /* DT_PLTGOT */ 154 } 155 } 156 157 static void 158 ld_mach_update_odynamic(Ofl_desc *ofl, Dyn **dyn) 159 { 160 if (((ofl->ofl_flags & FLG_OF_RELOBJ) == 0) && ofl->ofl_pltcnt) { 161 (*dyn)->d_tag = DT_PLTGOT; 162 if (ofl->ofl_osgot) 163 (*dyn)->d_un.d_ptr = ofl->ofl_osgot->os_shdr->sh_addr; 164 else 165 (*dyn)->d_un.d_ptr = 0; 166 (*dyn)++; 167 } 168 } 169 170 static Xword 171 ld_calc_plt_addr(Sym_desc *sdp, Ofl_desc *ofl) 172 { 173 Xword value; 174 175 value = (Xword)(ofl->ofl_osplt->os_shdr->sh_addr) + 176 M_PLT_RESERVSZ + ((sdp->sd_aux->sa_PLTndx - 1) * M_PLT_ENTSIZE); 177 return (value); 178 } 179 180 /* 181 * Build a single plt entry - code is: 182 * JMP *name1@GOTPCREL(%rip) 183 * PUSHL $index 184 * JMP .PLT0 185 */ 186 static uchar_t pltn_entry[M_PLT_ENTSIZE] = { 187 /* 0x00 jmpq *name1@GOTPCREL(%rip) */ 0xff, 0x25, 0x00, 0x00, 0x00, 0x00, 188 /* 0x06 pushq $index */ 0x68, 0x00, 0x00, 0x00, 0x00, 189 /* 0x0b jmpq .plt0(%rip) */ 0xe9, 0x00, 0x00, 0x00, 0x00 190 /* 0x10 */ 191 }; 192 193 static uintptr_t 194 plt_entry(Ofl_desc * ofl, Sym_desc * sdp) 195 { 196 uchar_t *plt0, *pltent, *gotent; 197 Sword plt_off; 198 Word got_off; 199 Xword val1; 200 int bswap = (ofl->ofl_flags1 & FLG_OF1_ENCDIFF) != 0; 201 202 got_off = sdp->sd_aux->sa_PLTGOTndx * M_GOT_ENTSIZE; 203 plt_off = M_PLT_RESERVSZ + ((sdp->sd_aux->sa_PLTndx - 1) * 204 M_PLT_ENTSIZE); 205 plt0 = (uchar_t *)(ofl->ofl_osplt->os_outdata->d_buf); 206 pltent = plt0 + plt_off; 207 gotent = (uchar_t *)(ofl->ofl_osgot->os_outdata->d_buf) + got_off; 208 209 bcopy(pltn_entry, pltent, sizeof (pltn_entry)); 210 /* 211 * Fill in the got entry with the address of the next instruction. 212 */ 213 /* LINTED */ 214 *(Word *)gotent = ofl->ofl_osplt->os_shdr->sh_addr + plt_off + 215 M_PLT_INSSIZE; 216 if (bswap) 217 /* LINTED */ 218 *(Word *)gotent = ld_bswap_Word(*(Word *)gotent); 219 220 /* 221 * If '-z noreloc' is specified - skip the do_reloc_ld 222 * stage. 223 */ 224 if (!OFL_DO_RELOC(ofl)) 225 return (1); 226 227 /* 228 * patchup: 229 * jmpq *name1@gotpcrel(%rip) 230 * 231 * NOTE: 0x06 represents next instruction. 232 */ 233 val1 = (ofl->ofl_osgot->os_shdr->sh_addr + got_off) - 234 (ofl->ofl_osplt->os_shdr->sh_addr + plt_off) - 0x06; 235 236 if (do_reloc_ld(&rdesc_r_amd64_gotpcrel, &pltent[0x02], &val1, 237 syn_rdesc_sym_name, MSG_ORIG(MSG_SPECFIL_PLTENT), bswap, 238 ofl->ofl_lml) == 0) { 239 eprintf(ofl->ofl_lml, ERR_FATAL, MSG_INTL(MSG_PLT_PLTNFAIL), 240 sdp->sd_aux->sa_PLTndx, demangle(sdp->sd_name)); 241 return (S_ERROR); 242 } 243 244 /* 245 * patchup: 246 * pushq $pltndx 247 */ 248 val1 = (Xword)(sdp->sd_aux->sa_PLTndx - 1); 249 250 if (do_reloc_ld(&rdesc_r_amd64_32, &pltent[0x07], &val1, 251 syn_rdesc_sym_name, MSG_ORIG(MSG_SPECFIL_PLTENT), bswap, 252 ofl->ofl_lml) == 0) { 253 eprintf(ofl->ofl_lml, ERR_FATAL, MSG_INTL(MSG_PLT_PLTNFAIL), 254 sdp->sd_aux->sa_PLTndx, demangle(sdp->sd_name)); 255 return (S_ERROR); 256 } 257 258 /* 259 * patchup: 260 * jmpq .plt0(%rip) 261 * NOTE: 0x10 represents next instruction. The rather complex 262 * series of casts is necessary to sign extend an offset into 263 * a 64-bit value while satisfying various compiler error 264 * checks. Handle with care. 265 */ 266 val1 = (Xword)((intptr_t)((uintptr_t)plt0 - 267 (uintptr_t)(&pltent[0x10]))); 268 269 if (do_reloc_ld(&rdesc_r_amd64_pc32, &pltent[0x0c], &val1, 270 syn_rdesc_sym_name, MSG_ORIG(MSG_SPECFIL_PLTENT), bswap, 271 ofl->ofl_lml) == 0) { 272 eprintf(ofl->ofl_lml, ERR_FATAL, MSG_INTL(MSG_PLT_PLTNFAIL), 273 sdp->sd_aux->sa_PLTndx, demangle(sdp->sd_name)); 274 return (S_ERROR); 275 } 276 277 return (1); 278 } 279 280 static uintptr_t 281 ld_perform_outreloc(Rel_desc * orsp, Ofl_desc * ofl) 282 { 283 Os_desc * relosp, * osp = 0; 284 Word ndx; 285 Xword roffset, value; 286 Sxword raddend; 287 Rela rea; 288 char *relbits; 289 Sym_desc * sdp, * psym = (Sym_desc *)0; 290 int sectmoved = 0; 291 292 raddend = orsp->rel_raddend; 293 sdp = orsp->rel_sym; 294 295 /* 296 * If the section this relocation is against has been discarded 297 * (-zignore), then also discard (skip) the relocation itself. 298 */ 299 if (orsp->rel_isdesc && ((orsp->rel_flags & 300 (FLG_REL_GOT | FLG_REL_BSS | FLG_REL_PLT | FLG_REL_NOINFO)) == 0) && 301 (orsp->rel_isdesc->is_flags & FLG_IS_DISCARD)) { 302 DBG_CALL(Dbg_reloc_discard(ofl->ofl_lml, M_MACH, orsp)); 303 return (1); 304 } 305 306 /* 307 * If this is a relocation against a move table, or expanded move 308 * table, adjust the relocation entries. 309 */ 310 if (RELAUX_GET_MOVE(orsp)) 311 ld_adj_movereloc(ofl, orsp); 312 313 /* 314 * If this is a relocation against a section then we need to adjust the 315 * raddend field to compensate for the new position of the input section 316 * within the new output section. 317 */ 318 if (ELF_ST_TYPE(sdp->sd_sym->st_info) == STT_SECTION) { 319 if (ofl->ofl_parsyms && 320 (sdp->sd_isc->is_flags & FLG_IS_RELUPD) && 321 /* LINTED */ 322 (psym = ld_am_I_partial(orsp, orsp->rel_raddend))) { 323 DBG_CALL(Dbg_move_outsctadj(ofl->ofl_lml, psym)); 324 sectmoved = 1; 325 if (ofl->ofl_flags & FLG_OF_RELOBJ) 326 raddend = psym->sd_sym->st_value; 327 else 328 raddend = psym->sd_sym->st_value - 329 psym->sd_isc->is_osdesc->os_shdr->sh_addr; 330 /* LINTED */ 331 raddend += (Off)_elf_getxoff(psym->sd_isc->is_indata); 332 if (psym->sd_isc->is_shdr->sh_flags & SHF_ALLOC) 333 raddend += 334 psym->sd_isc->is_osdesc->os_shdr->sh_addr; 335 } else { 336 /* LINTED */ 337 raddend += (Off)_elf_getxoff(sdp->sd_isc->is_indata); 338 if (sdp->sd_isc->is_shdr->sh_flags & SHF_ALLOC) 339 raddend += 340 sdp->sd_isc->is_osdesc->os_shdr->sh_addr; 341 } 342 } 343 344 value = sdp->sd_sym->st_value; 345 346 if (orsp->rel_flags & FLG_REL_GOT) { 347 /* 348 * Note: for GOT relative relocations on amd64 349 * we discard the addend. It was relevant 350 * to the reference - not to the data item 351 * being referenced (ie: that -4 thing). 352 */ 353 raddend = 0; 354 osp = ofl->ofl_osgot; 355 roffset = ld_calc_got_offset(orsp, ofl); 356 357 } else if (orsp->rel_flags & FLG_REL_PLT) { 358 /* 359 * Note that relocations for PLT's actually 360 * cause a relocation againt the GOT. 361 */ 362 osp = ofl->ofl_osplt; 363 roffset = (ofl->ofl_osgot->os_shdr->sh_addr) + 364 sdp->sd_aux->sa_PLTGOTndx * M_GOT_ENTSIZE; 365 raddend = 0; 366 if (plt_entry(ofl, sdp) == S_ERROR) 367 return (S_ERROR); 368 369 } else if (orsp->rel_flags & FLG_REL_BSS) { 370 /* 371 * This must be a R_AMD64_COPY. For these set the roffset to 372 * point to the new symbols location. 373 */ 374 osp = ofl->ofl_isbss->is_osdesc; 375 roffset = value; 376 377 /* 378 * The raddend doesn't mean anything in a R_SPARC_COPY 379 * relocation. Null it out because it can confuse people. 380 */ 381 raddend = 0; 382 } else { 383 osp = RELAUX_GET_OSDESC(orsp); 384 385 /* 386 * Calculate virtual offset of reference point; equals offset 387 * into section + vaddr of section for loadable sections, or 388 * offset plus section displacement for nonloadable sections. 389 */ 390 roffset = orsp->rel_roffset + 391 (Off)_elf_getxoff(orsp->rel_isdesc->is_indata); 392 if (!(ofl->ofl_flags & FLG_OF_RELOBJ)) 393 roffset += orsp->rel_isdesc->is_osdesc-> 394 os_shdr->sh_addr; 395 } 396 397 if ((osp == 0) || ((relosp = osp->os_relosdesc) == 0)) 398 relosp = ofl->ofl_osrel; 399 400 /* 401 * Assign the symbols index for the output relocation. If the 402 * relocation refers to a SECTION symbol then it's index is based upon 403 * the output sections symbols index. Otherwise the index can be 404 * derived from the symbols index itself. 405 */ 406 if (orsp->rel_rtype == R_AMD64_RELATIVE) 407 ndx = STN_UNDEF; 408 else if ((orsp->rel_flags & FLG_REL_SCNNDX) || 409 (ELF_ST_TYPE(sdp->sd_sym->st_info) == STT_SECTION)) { 410 if (sectmoved == 0) { 411 /* 412 * Check for a null input section. This can 413 * occur if this relocation references a symbol 414 * generated by sym_add_sym(). 415 */ 416 if (sdp->sd_isc && sdp->sd_isc->is_osdesc) 417 ndx = sdp->sd_isc->is_osdesc->os_identndx; 418 else 419 ndx = sdp->sd_shndx; 420 } else 421 ndx = ofl->ofl_parexpnndx; 422 } else 423 ndx = sdp->sd_symndx; 424 425 /* 426 * Add the symbols 'value' to the addend field. 427 */ 428 if (orsp->rel_flags & FLG_REL_ADVAL) 429 raddend += value; 430 431 /* 432 * The addend field for R_AMD64_DTPMOD64 means nothing. The addend 433 * is propagated in the corresponding R_AMD64_DTPOFF64 relocation. 434 */ 435 if (orsp->rel_rtype == R_AMD64_DTPMOD64) 436 raddend = 0; 437 438 relbits = (char *)relosp->os_outdata->d_buf; 439 440 rea.r_info = ELF_R_INFO(ndx, orsp->rel_rtype); 441 rea.r_offset = roffset; 442 rea.r_addend = raddend; 443 DBG_CALL(Dbg_reloc_out(ofl, ELF_DBG_LD, SHT_RELA, &rea, relosp->os_name, 444 ld_reloc_sym_name(orsp))); 445 446 /* 447 * Assert we haven't walked off the end of our relocation table. 448 */ 449 assert(relosp->os_szoutrels <= relosp->os_shdr->sh_size); 450 451 (void) memcpy((relbits + relosp->os_szoutrels), 452 (char *)&rea, sizeof (Rela)); 453 relosp->os_szoutrels += (Xword)sizeof (Rela); 454 455 /* 456 * Determine if this relocation is against a non-writable, allocatable 457 * section. If so we may need to provide a text relocation diagnostic. 458 * Note that relocations against the .plt (R_AMD64_JUMP_SLOT) actually 459 * result in modifications to the .got. 460 */ 461 if (orsp->rel_rtype == R_AMD64_JUMP_SLOT) 462 osp = ofl->ofl_osgot; 463 464 ld_reloc_remain_entry(orsp, osp, ofl); 465 return (1); 466 } 467 468 /* 469 * amd64 Instructions for TLS processing 470 */ 471 static uchar_t tlsinstr_gd_ie[] = { 472 /* 473 * 0x00 movq %fs:0, %rax 474 */ 475 0x64, 0x48, 0x8b, 0x04, 0x25, 476 0x00, 0x00, 0x00, 0x00, 477 /* 478 * 0x09 addq x@gottpoff(%rip), %rax 479 */ 480 0x48, 0x03, 0x05, 0x00, 0x00, 481 0x00, 0x00 482 }; 483 484 static uchar_t tlsinstr_gd_le[] = { 485 /* 486 * 0x00 movq %fs:0, %rax 487 */ 488 0x64, 0x48, 0x8b, 0x04, 0x25, 489 0x00, 0x00, 0x00, 0x00, 490 /* 491 * 0x09 leaq x@gottpoff(%rip), %rax 492 */ 493 0x48, 0x8d, 0x80, 0x00, 0x00, 494 0x00, 0x00 495 }; 496 497 static uchar_t tlsinstr_ld_le[] = { 498 /* 499 * .byte 0x66 500 */ 501 0x66, 502 /* 503 * .byte 0x66 504 */ 505 0x66, 506 /* 507 * .byte 0x66 508 */ 509 0x66, 510 /* 511 * movq %fs:0, %rax 512 */ 513 0x64, 0x48, 0x8b, 0x04, 0x25, 514 0x00, 0x00, 0x00, 0x00 515 }; 516 517 518 static Fixupret 519 tls_fixups(Ofl_desc *ofl, Rel_desc *arsp) 520 { 521 Sym_desc *sdp = arsp->rel_sym; 522 Word rtype = arsp->rel_rtype; 523 uchar_t *offset; 524 525 offset = (uchar_t *)((uintptr_t)arsp->rel_roffset + 526 (uintptr_t)_elf_getxoff(arsp->rel_isdesc->is_indata) + 527 (uintptr_t)RELAUX_GET_OSDESC(arsp)->os_outdata->d_buf); 528 529 if (sdp->sd_ref == REF_DYN_NEED) { 530 /* 531 * IE reference model 532 */ 533 switch (rtype) { 534 case R_AMD64_TLSGD: 535 /* 536 * GD -> IE 537 * 538 * Transition: 539 * 0x00 .byte 0x66 540 * 0x01 leaq x@tlsgd(%rip), %rdi 541 * 0x08 .word 0x6666 542 * 0x0a rex64 543 * 0x0b call __tls_get_addr@plt 544 * 0x10 545 * To: 546 * 0x00 movq %fs:0, %rax 547 * 0x09 addq x@gottpoff(%rip), %rax 548 * 0x10 549 */ 550 DBG_CALL(Dbg_reloc_transition(ofl->ofl_lml, M_MACH, 551 R_AMD64_GOTTPOFF, arsp, ld_reloc_sym_name)); 552 arsp->rel_rtype = R_AMD64_GOTTPOFF; 553 arsp->rel_roffset += 8; 554 arsp->rel_raddend = (Sxword)-4; 555 556 /* 557 * Adjust 'offset' to beginning of instruction 558 * sequence. 559 */ 560 offset -= 4; 561 (void) memcpy(offset, tlsinstr_gd_ie, 562 sizeof (tlsinstr_gd_ie)); 563 return (FIX_RELOC); 564 565 case R_AMD64_PLT32: 566 /* 567 * Fixup done via the TLS_GD relocation. 568 */ 569 DBG_CALL(Dbg_reloc_transition(ofl->ofl_lml, M_MACH, 570 R_AMD64_NONE, arsp, ld_reloc_sym_name)); 571 return (FIX_DONE); 572 } 573 } 574 575 /* 576 * LE reference model 577 */ 578 switch (rtype) { 579 case R_AMD64_TLSGD: 580 /* 581 * GD -> LE 582 * 583 * Transition: 584 * 0x00 .byte 0x66 585 * 0x01 leaq x@tlsgd(%rip), %rdi 586 * 0x08 .word 0x6666 587 * 0x0a rex64 588 * 0x0b call __tls_get_addr@plt 589 * 0x10 590 * To: 591 * 0x00 movq %fs:0, %rax 592 * 0x09 leaq x@tpoff(%rax), %rax 593 * 0x10 594 */ 595 DBG_CALL(Dbg_reloc_transition(ofl->ofl_lml, M_MACH, 596 R_AMD64_TPOFF32, arsp, ld_reloc_sym_name)); 597 arsp->rel_rtype = R_AMD64_TPOFF32; 598 arsp->rel_roffset += 8; 599 arsp->rel_raddend = 0; 600 601 /* 602 * Adjust 'offset' to beginning of instruction sequence. 603 */ 604 offset -= 4; 605 (void) memcpy(offset, tlsinstr_gd_le, sizeof (tlsinstr_gd_le)); 606 return (FIX_RELOC); 607 608 case R_AMD64_GOTTPOFF: 609 /* 610 * IE -> LE 611 * 612 * Transition: 613 * 0x00 movq %fs:0, %rax 614 * 0x09 addq x@gottopoff(%rip), %rax 615 * 0x10 616 * To: 617 * 0x00 movq %fs:0, %rax 618 * 0x09 leaq x@tpoff(%rax), %rax 619 * 0x10 620 */ 621 DBG_CALL(Dbg_reloc_transition(ofl->ofl_lml, M_MACH, 622 R_AMD64_TPOFF32, arsp, ld_reloc_sym_name)); 623 arsp->rel_rtype = R_AMD64_TPOFF32; 624 arsp->rel_raddend = 0; 625 626 /* 627 * Adjust 'offset' to beginning of instruction sequence. 628 */ 629 offset -= 12; 630 631 /* 632 * Same code sequence used in the GD -> LE transition. 633 */ 634 (void) memcpy(offset, tlsinstr_gd_le, sizeof (tlsinstr_gd_le)); 635 return (FIX_RELOC); 636 637 case R_AMD64_TLSLD: 638 /* 639 * LD -> LE 640 * 641 * Transition 642 * 0x00 leaq x1@tlsgd(%rip), %rdi 643 * 0x07 call __tls_get_addr@plt 644 * 0x0c 645 * To: 646 * 0x00 .byte 0x66 647 * 0x01 .byte 0x66 648 * 0x02 .byte 0x66 649 * 0x03 movq %fs:0, %rax 650 */ 651 DBG_CALL(Dbg_reloc_transition(ofl->ofl_lml, M_MACH, 652 R_AMD64_NONE, arsp, ld_reloc_sym_name)); 653 offset -= 3; 654 (void) memcpy(offset, tlsinstr_ld_le, sizeof (tlsinstr_ld_le)); 655 return (FIX_DONE); 656 657 case R_AMD64_DTPOFF32: 658 /* 659 * LD->LE 660 * 661 * Transition: 662 * 0x00 leaq x1@dtpoff(%rax), %rcx 663 * To: 664 * 0x00 leaq x1@tpoff(%rax), %rcx 665 */ 666 DBG_CALL(Dbg_reloc_transition(ofl->ofl_lml, M_MACH, 667 R_AMD64_TPOFF32, arsp, ld_reloc_sym_name)); 668 arsp->rel_rtype = R_AMD64_TPOFF32; 669 arsp->rel_raddend = 0; 670 return (FIX_RELOC); 671 } 672 673 return (FIX_RELOC); 674 } 675 676 static uintptr_t 677 ld_do_activerelocs(Ofl_desc *ofl) 678 { 679 Rel_desc *arsp; 680 Rel_cachebuf *rcbp; 681 Aliste idx; 682 uintptr_t return_code = 1; 683 ofl_flag_t flags = ofl->ofl_flags; 684 685 if (aplist_nitems(ofl->ofl_actrels.rc_list) != 0) 686 DBG_CALL(Dbg_reloc_doact_title(ofl->ofl_lml)); 687 688 /* 689 * Process active relocations. 690 */ 691 REL_CACHE_TRAVERSE(&ofl->ofl_actrels, idx, rcbp, arsp) { 692 uchar_t *addr; 693 Xword value; 694 Sym_desc *sdp; 695 const char *ifl_name; 696 Xword refaddr; 697 int moved = 0; 698 Gotref gref; 699 Os_desc *osp; 700 701 /* 702 * If the section this relocation is against has been discarded 703 * (-zignore), then discard (skip) the relocation itself. 704 */ 705 if ((arsp->rel_isdesc->is_flags & FLG_IS_DISCARD) && 706 ((arsp->rel_flags & (FLG_REL_GOT | FLG_REL_BSS | 707 FLG_REL_PLT | FLG_REL_NOINFO)) == 0)) { 708 DBG_CALL(Dbg_reloc_discard(ofl->ofl_lml, M_MACH, arsp)); 709 continue; 710 } 711 712 /* 713 * We determine what the 'got reference' model (if required) 714 * is at this point. This needs to be done before tls_fixup() 715 * since it may 'transition' our instructions. 716 * 717 * The got table entries have already been assigned, 718 * and we bind to those initial entries. 719 */ 720 if (arsp->rel_flags & FLG_REL_DTLS) 721 gref = GOT_REF_TLSGD; 722 else if (arsp->rel_flags & FLG_REL_MTLS) 723 gref = GOT_REF_TLSLD; 724 else if (arsp->rel_flags & FLG_REL_STLS) 725 gref = GOT_REF_TLSIE; 726 else 727 gref = GOT_REF_GENERIC; 728 729 /* 730 * Perform any required TLS fixups. 731 */ 732 if (arsp->rel_flags & FLG_REL_TLSFIX) { 733 Fixupret ret; 734 735 if ((ret = tls_fixups(ofl, arsp)) == FIX_ERROR) 736 return (S_ERROR); 737 if (ret == FIX_DONE) 738 continue; 739 } 740 741 /* 742 * If this is a relocation against a move table, or 743 * expanded move table, adjust the relocation entries. 744 */ 745 if (RELAUX_GET_MOVE(arsp)) 746 ld_adj_movereloc(ofl, arsp); 747 748 sdp = arsp->rel_sym; 749 refaddr = arsp->rel_roffset + 750 (Off)_elf_getxoff(arsp->rel_isdesc->is_indata); 751 752 if ((arsp->rel_flags & FLG_REL_CLVAL) || 753 (arsp->rel_flags & FLG_REL_GOTCL)) 754 value = 0; 755 else if (ELF_ST_TYPE(sdp->sd_sym->st_info) == STT_SECTION) { 756 Sym_desc *sym; 757 758 /* 759 * The value for a symbol pointing to a SECTION 760 * is based off of that sections position. 761 */ 762 if ((sdp->sd_isc->is_flags & FLG_IS_RELUPD) && 763 /* LINTED */ 764 (sym = ld_am_I_partial(arsp, arsp->rel_raddend))) { 765 /* 766 * The symbol was moved, so adjust the value 767 * relative to the new section. 768 */ 769 value = sym->sd_sym->st_value; 770 moved = 1; 771 772 /* 773 * The original raddend covers the displacement 774 * from the section start to the desired 775 * address. The value computed above gets us 776 * from the section start to the start of the 777 * symbol range. Adjust the old raddend to 778 * remove the offset from section start to 779 * symbol start, leaving the displacement 780 * within the range of the symbol. 781 */ 782 arsp->rel_raddend -= sym->sd_osym->st_value; 783 } else { 784 value = _elf_getxoff(sdp->sd_isc->is_indata); 785 if (sdp->sd_isc->is_shdr->sh_flags & SHF_ALLOC) 786 value += sdp->sd_isc->is_osdesc-> 787 os_shdr->sh_addr; 788 } 789 if (sdp->sd_isc->is_shdr->sh_flags & SHF_TLS) 790 value -= ofl->ofl_tlsphdr->p_vaddr; 791 792 } else if (IS_SIZE(arsp->rel_rtype)) { 793 /* 794 * Size relocations require the symbols size. 795 */ 796 value = sdp->sd_sym->st_size; 797 798 } else if ((sdp->sd_flags & FLG_SY_CAP) && 799 sdp->sd_aux && sdp->sd_aux->sa_PLTndx) { 800 /* 801 * If relocation is against a capabilities symbol, we 802 * need to jump to an associated PLT, so that at runtime 803 * ld.so.1 is involved to determine the best binding 804 * choice. Otherwise, the value is the symbols value. 805 */ 806 value = ld_calc_plt_addr(sdp, ofl); 807 } else 808 value = sdp->sd_sym->st_value; 809 810 /* 811 * Relocation against the GLOBAL_OFFSET_TABLE. 812 */ 813 if ((arsp->rel_flags & FLG_REL_GOT) && 814 !ld_reloc_set_aux_osdesc(ofl, arsp, ofl->ofl_osgot)) 815 return (S_ERROR); 816 osp = RELAUX_GET_OSDESC(arsp); 817 818 /* 819 * If loadable and not producing a relocatable object add the 820 * sections virtual address to the reference address. 821 */ 822 if ((arsp->rel_flags & FLG_REL_LOAD) && 823 ((flags & FLG_OF_RELOBJ) == 0)) 824 refaddr += arsp->rel_isdesc->is_osdesc-> 825 os_shdr->sh_addr; 826 827 /* 828 * If this entry has a PLT assigned to it, its value is actually 829 * the address of the PLT (and not the address of the function). 830 */ 831 if (IS_PLT(arsp->rel_rtype)) { 832 if (sdp->sd_aux && sdp->sd_aux->sa_PLTndx) 833 value = ld_calc_plt_addr(sdp, ofl); 834 } 835 836 /* 837 * Add relocations addend to value. Add extra 838 * relocation addend if needed. 839 * 840 * Note: For GOT relative relocations on amd64 we discard the 841 * addend. It was relevant to the reference - not to the 842 * data item being referenced (ie: that -4 thing). 843 */ 844 if ((arsp->rel_flags & FLG_REL_GOT) == 0) 845 value += arsp->rel_raddend; 846 847 /* 848 * Determine whether the value needs further adjustment. Filter 849 * through the attributes of the relocation to determine what 850 * adjustment is required. Note, many of the following cases 851 * are only applicable when a .got is present. As a .got is 852 * not generated when a relocatable object is being built, 853 * any adjustments that require a .got need to be skipped. 854 */ 855 if ((arsp->rel_flags & FLG_REL_GOT) && 856 ((flags & FLG_OF_RELOBJ) == 0)) { 857 Xword R1addr; 858 uintptr_t R2addr; 859 Word gotndx; 860 Gotndx *gnp; 861 862 /* 863 * Perform relocation against GOT table. Since this 864 * doesn't fit exactly into a relocation we place the 865 * appropriate byte in the GOT directly 866 * 867 * Calculate offset into GOT at which to apply 868 * the relocation. 869 */ 870 gnp = ld_find_got_ndx(sdp->sd_GOTndxs, gref, ofl, arsp); 871 assert(gnp); 872 873 if (arsp->rel_rtype == R_AMD64_DTPOFF64) 874 gotndx = gnp->gn_gotndx + 1; 875 else 876 gotndx = gnp->gn_gotndx; 877 878 R1addr = (Xword)(gotndx * M_GOT_ENTSIZE); 879 880 /* 881 * Add the GOTs data's offset. 882 */ 883 R2addr = R1addr + (uintptr_t)osp->os_outdata->d_buf; 884 885 DBG_CALL(Dbg_reloc_doact(ofl->ofl_lml, ELF_DBG_LD_ACT, 886 M_MACH, SHT_RELA, arsp, R1addr, value, 887 ld_reloc_sym_name)); 888 889 /* 890 * And do it. 891 */ 892 if (ofl->ofl_flags1 & FLG_OF1_ENCDIFF) 893 *(Xword *)R2addr = ld_bswap_Xword(value); 894 else 895 *(Xword *)R2addr = value; 896 continue; 897 898 } else if (IS_GOT_BASED(arsp->rel_rtype) && 899 ((flags & FLG_OF_RELOBJ) == 0)) { 900 value -= ofl->ofl_osgot->os_shdr->sh_addr; 901 902 } else if (IS_GOTPCREL(arsp->rel_rtype) && 903 ((flags & FLG_OF_RELOBJ) == 0)) { 904 Gotndx *gnp; 905 906 /* 907 * Calculation: 908 * G + GOT + A - P 909 */ 910 gnp = ld_find_got_ndx(sdp->sd_GOTndxs, gref, ofl, arsp); 911 assert(gnp); 912 value = (Xword)(ofl->ofl_osgot->os_shdr-> sh_addr) + 913 ((Xword)gnp->gn_gotndx * M_GOT_ENTSIZE) + 914 arsp->rel_raddend - refaddr; 915 916 } else if (IS_GOT_PC(arsp->rel_rtype) && 917 ((flags & FLG_OF_RELOBJ) == 0)) { 918 value = (Xword)(ofl->ofl_osgot->os_shdr-> 919 sh_addr) - refaddr + arsp->rel_raddend; 920 921 } else if ((IS_PC_RELATIVE(arsp->rel_rtype)) && 922 (((flags & FLG_OF_RELOBJ) == 0) || 923 (osp == sdp->sd_isc->is_osdesc))) { 924 value -= refaddr; 925 926 } else if (IS_TLS_INS(arsp->rel_rtype) && 927 IS_GOT_RELATIVE(arsp->rel_rtype) && 928 ((flags & FLG_OF_RELOBJ) == 0)) { 929 Gotndx *gnp; 930 931 gnp = ld_find_got_ndx(sdp->sd_GOTndxs, gref, ofl, arsp); 932 assert(gnp); 933 value = (Xword)gnp->gn_gotndx * M_GOT_ENTSIZE; 934 935 } else if (IS_GOT_RELATIVE(arsp->rel_rtype) && 936 ((flags & FLG_OF_RELOBJ) == 0)) { 937 Gotndx *gnp; 938 939 gnp = ld_find_got_ndx(sdp->sd_GOTndxs, gref, ofl, arsp); 940 assert(gnp); 941 value = (Xword)gnp->gn_gotndx * M_GOT_ENTSIZE; 942 943 } else if ((arsp->rel_flags & FLG_REL_STLS) && 944 ((flags & FLG_OF_RELOBJ) == 0)) { 945 Xword tlsstatsize; 946 947 /* 948 * This is the LE TLS reference model. Static 949 * offset is hard-coded. 950 */ 951 tlsstatsize = S_ROUND(ofl->ofl_tlsphdr->p_memsz, 952 M_TLSSTATALIGN); 953 value = tlsstatsize - value; 954 955 /* 956 * Since this code is fixed up, it assumes a negative 957 * offset that can be added to the thread pointer. 958 */ 959 if (arsp->rel_rtype == R_AMD64_TPOFF32) 960 value = -value; 961 } 962 963 if (arsp->rel_isdesc->is_file) 964 ifl_name = arsp->rel_isdesc->is_file->ifl_name; 965 else 966 ifl_name = MSG_INTL(MSG_STR_NULL); 967 968 /* 969 * Make sure we have data to relocate. Compiler and assembler 970 * developers have been known to generate relocations against 971 * invalid sections (normally .bss), so for their benefit give 972 * them sufficient information to help analyze the problem. 973 * End users should never see this. 974 */ 975 if (arsp->rel_isdesc->is_indata->d_buf == 0) { 976 Conv_inv_buf_t inv_buf; 977 978 eprintf(ofl->ofl_lml, ERR_FATAL, 979 MSG_INTL(MSG_REL_EMPTYSEC), 980 conv_reloc_amd64_type(arsp->rel_rtype, 0, &inv_buf), 981 ifl_name, ld_reloc_sym_name(arsp), 982 EC_WORD(arsp->rel_isdesc->is_scnndx), 983 arsp->rel_isdesc->is_name); 984 return (S_ERROR); 985 } 986 987 /* 988 * Get the address of the data item we need to modify. 989 */ 990 addr = (uchar_t *)((uintptr_t)arsp->rel_roffset + 991 (uintptr_t)_elf_getxoff(arsp->rel_isdesc->is_indata)); 992 993 DBG_CALL(Dbg_reloc_doact(ofl->ofl_lml, ELF_DBG_LD_ACT, 994 M_MACH, SHT_RELA, arsp, EC_NATPTR(addr), value, 995 ld_reloc_sym_name)); 996 addr += (uintptr_t)osp->os_outdata->d_buf; 997 998 if ((((uintptr_t)addr - (uintptr_t)ofl->ofl_nehdr) > 999 ofl->ofl_size) || (arsp->rel_roffset > 1000 osp->os_shdr->sh_size)) { 1001 int class; 1002 Conv_inv_buf_t inv_buf; 1003 1004 if (((uintptr_t)addr - (uintptr_t)ofl->ofl_nehdr) > 1005 ofl->ofl_size) 1006 class = ERR_FATAL; 1007 else 1008 class = ERR_WARNING; 1009 1010 eprintf(ofl->ofl_lml, class, 1011 MSG_INTL(MSG_REL_INVALOFFSET), 1012 conv_reloc_amd64_type(arsp->rel_rtype, 0, &inv_buf), 1013 ifl_name, EC_WORD(arsp->rel_isdesc->is_scnndx), 1014 arsp->rel_isdesc->is_name, ld_reloc_sym_name(arsp), 1015 EC_ADDR((uintptr_t)addr - 1016 (uintptr_t)ofl->ofl_nehdr)); 1017 1018 if (class == ERR_FATAL) { 1019 return_code = S_ERROR; 1020 continue; 1021 } 1022 } 1023 1024 /* 1025 * The relocation is additive. Ignore the previous symbol 1026 * value if this local partial symbol is expanded. 1027 */ 1028 if (moved) 1029 value -= *addr; 1030 1031 /* 1032 * If '-z noreloc' is specified - skip the do_reloc_ld stage. 1033 */ 1034 if (OFL_DO_RELOC(ofl)) { 1035 /* 1036 * If this is a PROGBITS section and the running linker 1037 * has a different byte order than the target host, 1038 * tell do_reloc_ld() to swap bytes. 1039 */ 1040 if (do_reloc_ld(arsp, addr, &value, ld_reloc_sym_name, 1041 ifl_name, OFL_SWAP_RELOC_DATA(ofl, arsp), 1042 ofl->ofl_lml) == 0) 1043 return_code = S_ERROR; 1044 } 1045 } 1046 return (return_code); 1047 } 1048 1049 static uintptr_t 1050 ld_add_outrel(Word flags, Rel_desc *rsp, Ofl_desc *ofl) 1051 { 1052 Rel_desc *orsp; 1053 Sym_desc *sdp = rsp->rel_sym; 1054 1055 /* 1056 * Static executables *do not* want any relocations against them. 1057 * Since our engine still creates relocations against a WEAK UNDEFINED 1058 * symbol in a static executable, it's best to disable them here 1059 * instead of through out the relocation code. 1060 */ 1061 if (OFL_IS_STATIC_EXEC(ofl)) 1062 return (1); 1063 1064 /* 1065 * If we are adding a output relocation against a section 1066 * symbol (non-RELATIVE) then mark that section. These sections 1067 * will be added to the .dynsym symbol table. 1068 */ 1069 if (sdp && (rsp->rel_rtype != M_R_RELATIVE) && 1070 ((flags & FLG_REL_SCNNDX) || 1071 (ELF_ST_TYPE(sdp->sd_sym->st_info) == STT_SECTION))) { 1072 1073 /* 1074 * If this is a COMMON symbol - no output section 1075 * exists yet - (it's created as part of sym_validate()). 1076 * So - we mark here that when it's created it should 1077 * be tagged with the FLG_OS_OUTREL flag. 1078 */ 1079 if ((sdp->sd_flags & FLG_SY_SPECSEC) && 1080 (sdp->sd_sym->st_shndx == SHN_COMMON)) { 1081 if (ELF_ST_TYPE(sdp->sd_sym->st_info) != STT_TLS) 1082 ofl->ofl_flags1 |= FLG_OF1_BSSOREL; 1083 else 1084 ofl->ofl_flags1 |= FLG_OF1_TLSOREL; 1085 } else { 1086 Os_desc *osp; 1087 Is_desc *isp = sdp->sd_isc; 1088 1089 if (isp && ((osp = isp->is_osdesc) != NULL) && 1090 ((osp->os_flags & FLG_OS_OUTREL) == 0)) { 1091 ofl->ofl_dynshdrcnt++; 1092 osp->os_flags |= FLG_OS_OUTREL; 1093 } 1094 } 1095 } 1096 1097 /* Enter it into the output relocation cache */ 1098 if ((orsp = ld_reloc_enter(ofl, &ofl->ofl_outrels, rsp, flags)) == NULL) 1099 return (S_ERROR); 1100 1101 if (flags & FLG_REL_GOT) 1102 ofl->ofl_relocgotsz += (Xword)sizeof (Rela); 1103 else if (flags & FLG_REL_PLT) 1104 ofl->ofl_relocpltsz += (Xword)sizeof (Rela); 1105 else if (flags & FLG_REL_BSS) 1106 ofl->ofl_relocbsssz += (Xword)sizeof (Rela); 1107 else if (flags & FLG_REL_NOINFO) 1108 ofl->ofl_relocrelsz += (Xword)sizeof (Rela); 1109 else 1110 RELAUX_GET_OSDESC(orsp)->os_szoutrels += (Xword)sizeof (Rela); 1111 1112 if (orsp->rel_rtype == M_R_RELATIVE) 1113 ofl->ofl_relocrelcnt++; 1114 1115 /* 1116 * We don't perform sorting on PLT relocations because 1117 * they have already been assigned a PLT index and if we 1118 * were to sort them we would have to re-assign the plt indexes. 1119 */ 1120 if (!(flags & FLG_REL_PLT)) 1121 ofl->ofl_reloccnt++; 1122 1123 /* 1124 * Insure a GLOBAL_OFFSET_TABLE is generated if required. 1125 */ 1126 if (IS_GOT_REQUIRED(orsp->rel_rtype)) 1127 ofl->ofl_flags |= FLG_OF_BLDGOT; 1128 1129 /* 1130 * Identify and possibly warn of a displacement relocation. 1131 */ 1132 if (orsp->rel_flags & FLG_REL_DISP) { 1133 ofl->ofl_dtflags_1 |= DF_1_DISPRELPND; 1134 1135 if (ofl->ofl_flags & FLG_OF_VERBOSE) 1136 ld_disp_errmsg(MSG_INTL(MSG_REL_DISPREL4), orsp, ofl); 1137 } 1138 DBG_CALL(Dbg_reloc_ors_entry(ofl->ofl_lml, ELF_DBG_LD, SHT_RELA, 1139 M_MACH, orsp)); 1140 return (1); 1141 } 1142 1143 /* 1144 * process relocation for a LOCAL symbol 1145 */ 1146 static uintptr_t 1147 ld_reloc_local(Rel_desc * rsp, Ofl_desc * ofl) 1148 { 1149 ofl_flag_t flags = ofl->ofl_flags; 1150 Sym_desc *sdp = rsp->rel_sym; 1151 Word shndx = sdp->sd_sym->st_shndx; 1152 Word ortype = rsp->rel_rtype; 1153 1154 /* 1155 * if ((shared object) and (not pc relative relocation) and 1156 * (not against ABS symbol)) 1157 * then 1158 * build R_AMD64_RELATIVE 1159 * fi 1160 */ 1161 if ((flags & FLG_OF_SHAROBJ) && (rsp->rel_flags & FLG_REL_LOAD) && 1162 !(IS_PC_RELATIVE(rsp->rel_rtype)) && !(IS_SIZE(rsp->rel_rtype)) && 1163 !(IS_GOT_BASED(rsp->rel_rtype)) && 1164 !(rsp->rel_isdesc != NULL && 1165 (rsp->rel_isdesc->is_shdr->sh_type == SHT_SUNW_dof)) && 1166 (((sdp->sd_flags & FLG_SY_SPECSEC) == 0) || 1167 (shndx != SHN_ABS) || (sdp->sd_aux && sdp->sd_aux->sa_symspec))) { 1168 1169 /* 1170 * R_AMD64_RELATIVE updates a 64bit address, if this 1171 * relocation isn't a 64bit binding then we can not 1172 * simplify it to a RELATIVE relocation. 1173 */ 1174 if (reloc_table[ortype].re_fsize != sizeof (Addr)) { 1175 return (ld_add_outrel(0, rsp, ofl)); 1176 } 1177 1178 rsp->rel_rtype = R_AMD64_RELATIVE; 1179 if (ld_add_outrel(FLG_REL_ADVAL, rsp, ofl) == S_ERROR) 1180 return (S_ERROR); 1181 rsp->rel_rtype = ortype; 1182 return (1); 1183 } 1184 1185 /* 1186 * If the relocation is against a 'non-allocatable' section 1187 * and we can not resolve it now - then give a warning 1188 * message. 1189 * 1190 * We can not resolve the symbol if either: 1191 * a) it's undefined 1192 * b) it's defined in a shared library and a 1193 * COPY relocation hasn't moved it to the executable 1194 * 1195 * Note: because we process all of the relocations against the 1196 * text segment before any others - we know whether 1197 * or not a copy relocation will be generated before 1198 * we get here (see reloc_init()->reloc_segments()). 1199 */ 1200 if (!(rsp->rel_flags & FLG_REL_LOAD) && 1201 ((shndx == SHN_UNDEF) || 1202 ((sdp->sd_ref == REF_DYN_NEED) && 1203 ((sdp->sd_flags & FLG_SY_MVTOCOMM) == 0)))) { 1204 Conv_inv_buf_t inv_buf; 1205 Os_desc *osp = RELAUX_GET_OSDESC(rsp); 1206 1207 /* 1208 * If the relocation is against a SHT_SUNW_ANNOTATE 1209 * section - then silently ignore that the relocation 1210 * can not be resolved. 1211 */ 1212 if (osp && (osp->os_shdr->sh_type == SHT_SUNW_ANNOTATE)) 1213 return (0); 1214 (void) eprintf(ofl->ofl_lml, ERR_WARNING, 1215 MSG_INTL(MSG_REL_EXTERNSYM), 1216 conv_reloc_amd64_type(rsp->rel_rtype, 0, &inv_buf), 1217 rsp->rel_isdesc->is_file->ifl_name, 1218 ld_reloc_sym_name(rsp), osp->os_name); 1219 return (1); 1220 } 1221 1222 /* 1223 * Perform relocation. 1224 */ 1225 return (ld_add_actrel(NULL, rsp, ofl)); 1226 } 1227 1228 1229 static uintptr_t 1230 ld_reloc_TLS(Boolean local, Rel_desc * rsp, Ofl_desc * ofl) 1231 { 1232 Word rtype = rsp->rel_rtype; 1233 Sym_desc *sdp = rsp->rel_sym; 1234 ofl_flag_t flags = ofl->ofl_flags; 1235 Gotndx *gnp; 1236 1237 /* 1238 * If we're building an executable - use either the IE or LE access 1239 * model. If we're building a shared object process any IE model. 1240 */ 1241 if ((flags & FLG_OF_EXEC) || (IS_TLS_IE(rtype))) { 1242 /* 1243 * Set the DF_STATIC_TLS flag. 1244 */ 1245 ofl->ofl_dtflags |= DF_STATIC_TLS; 1246 1247 if (!local || ((flags & FLG_OF_EXEC) == 0)) { 1248 /* 1249 * Assign a GOT entry for static TLS references. 1250 */ 1251 if ((gnp = ld_find_got_ndx(sdp->sd_GOTndxs, 1252 GOT_REF_TLSIE, ofl, rsp)) == NULL) { 1253 1254 if (ld_assign_got_TLS(local, rsp, ofl, sdp, 1255 gnp, GOT_REF_TLSIE, FLG_REL_STLS, 1256 rtype, R_AMD64_TPOFF64, 0) == S_ERROR) 1257 return (S_ERROR); 1258 } 1259 1260 /* 1261 * IE access model. 1262 */ 1263 if (IS_TLS_IE(rtype)) 1264 return (ld_add_actrel(FLG_REL_STLS, rsp, ofl)); 1265 1266 /* 1267 * Fixups are required for other executable models. 1268 */ 1269 return (ld_add_actrel((FLG_REL_TLSFIX | FLG_REL_STLS), 1270 rsp, ofl)); 1271 } 1272 1273 /* 1274 * LE access model. 1275 */ 1276 if (IS_TLS_LE(rtype)) 1277 return (ld_add_actrel(FLG_REL_STLS, rsp, ofl)); 1278 1279 return (ld_add_actrel((FLG_REL_TLSFIX | FLG_REL_STLS), 1280 rsp, ofl)); 1281 } 1282 1283 /* 1284 * Building a shared object. 1285 * 1286 * Assign a GOT entry for a dynamic TLS reference. 1287 */ 1288 if (IS_TLS_LD(rtype) && ((gnp = ld_find_got_ndx(sdp->sd_GOTndxs, 1289 GOT_REF_TLSLD, ofl, rsp)) == NULL)) { 1290 1291 if (ld_assign_got_TLS(local, rsp, ofl, sdp, gnp, GOT_REF_TLSLD, 1292 FLG_REL_MTLS, rtype, R_AMD64_DTPMOD64, NULL) == S_ERROR) 1293 return (S_ERROR); 1294 1295 } else if (IS_TLS_GD(rtype) && 1296 ((gnp = ld_find_got_ndx(sdp->sd_GOTndxs, GOT_REF_TLSGD, 1297 ofl, rsp)) == NULL)) { 1298 1299 if (ld_assign_got_TLS(local, rsp, ofl, sdp, gnp, GOT_REF_TLSGD, 1300 FLG_REL_DTLS, rtype, R_AMD64_DTPMOD64, 1301 R_AMD64_DTPOFF64) == S_ERROR) 1302 return (S_ERROR); 1303 } 1304 1305 if (IS_TLS_LD(rtype)) 1306 return (ld_add_actrel(FLG_REL_MTLS, rsp, ofl)); 1307 1308 return (ld_add_actrel(FLG_REL_DTLS, rsp, ofl)); 1309 } 1310 1311 /* ARGSUSED5 */ 1312 static uintptr_t 1313 ld_assign_got_ndx(Alist **alpp, Gotndx *pgnp, Gotref gref, Ofl_desc *ofl, 1314 Rel_desc *rsp, Sym_desc *sdp) 1315 { 1316 Xword raddend; 1317 Gotndx gn, *gnp; 1318 Aliste idx; 1319 uint_t gotents; 1320 1321 raddend = rsp->rel_raddend; 1322 if (pgnp && (pgnp->gn_addend == raddend) && (pgnp->gn_gotref == gref)) 1323 return (1); 1324 1325 if ((gref == GOT_REF_TLSGD) || (gref == GOT_REF_TLSLD)) 1326 gotents = 2; 1327 else 1328 gotents = 1; 1329 1330 gn.gn_addend = raddend; 1331 gn.gn_gotndx = ofl->ofl_gotcnt; 1332 gn.gn_gotref = gref; 1333 1334 ofl->ofl_gotcnt += gotents; 1335 1336 if (gref == GOT_REF_TLSLD) { 1337 if (ofl->ofl_tlsldgotndx == NULL) { 1338 if ((gnp = libld_malloc(sizeof (Gotndx))) == NULL) 1339 return (S_ERROR); 1340 (void) memcpy(gnp, &gn, sizeof (Gotndx)); 1341 ofl->ofl_tlsldgotndx = gnp; 1342 } 1343 return (1); 1344 } 1345 1346 idx = 0; 1347 for (ALIST_TRAVERSE(*alpp, idx, gnp)) { 1348 if (gnp->gn_addend > raddend) 1349 break; 1350 } 1351 1352 /* 1353 * GOT indexes are maintained on an Alist, where there is typically 1354 * only one index. The usage of this list is to scan the list to find 1355 * an index, and then apply that index immediately to a relocation. 1356 * Thus there are no external references to these GOT index structures 1357 * that can be compromised by the Alist being reallocated. 1358 */ 1359 if (alist_insert(alpp, &gn, sizeof (Gotndx), 1360 AL_CNT_SDP_GOT, idx) == NULL) 1361 return (S_ERROR); 1362 1363 return (1); 1364 } 1365 1366 static void 1367 ld_assign_plt_ndx(Sym_desc * sdp, Ofl_desc *ofl) 1368 { 1369 sdp->sd_aux->sa_PLTndx = 1 + ofl->ofl_pltcnt++; 1370 sdp->sd_aux->sa_PLTGOTndx = ofl->ofl_gotcnt++; 1371 ofl->ofl_flags |= FLG_OF_BLDGOT; 1372 } 1373 1374 static uchar_t plt0_template[M_PLT_ENTSIZE] = { 1375 /* 0x00 PUSHQ GOT+8(%rip) */ 0xff, 0x35, 0x00, 0x00, 0x00, 0x00, 1376 /* 0x06 JMP *GOT+16(%rip) */ 0xff, 0x25, 0x00, 0x00, 0x00, 0x00, 1377 /* 0x0c NOP */ 0x90, 1378 /* 0x0d NOP */ 0x90, 1379 /* 0x0e NOP */ 0x90, 1380 /* 0x0f NOP */ 0x90 1381 }; 1382 1383 /* 1384 * Initializes .got[0] with the _DYNAMIC symbol value. 1385 */ 1386 static uintptr_t 1387 ld_fillin_gotplt(Ofl_desc *ofl) 1388 { 1389 int bswap = (ofl->ofl_flags1 & FLG_OF1_ENCDIFF) != 0; 1390 1391 if (ofl->ofl_osgot) { 1392 Sym_desc *sdp; 1393 1394 if ((sdp = ld_sym_find(MSG_ORIG(MSG_SYM_DYNAMIC_U), 1395 SYM_NOHASH, NULL, ofl)) != NULL) { 1396 uchar_t *genptr; 1397 1398 genptr = ((uchar_t *)ofl->ofl_osgot->os_outdata->d_buf + 1399 (M_GOT_XDYNAMIC * M_GOT_ENTSIZE)); 1400 /* LINTED */ 1401 *(Xword *)genptr = sdp->sd_sym->st_value; 1402 if (bswap) 1403 /* LINTED */ 1404 *(Xword *)genptr = 1405 /* LINTED */ 1406 ld_bswap_Xword(*(Xword *)genptr); 1407 } 1408 } 1409 1410 /* 1411 * Fill in the reserved slot in the procedure linkage table the first 1412 * entry is: 1413 * 0x00 PUSHQ GOT+8(%rip) # GOT[1] 1414 * 0x06 JMP *GOT+16(%rip) # GOT[2] 1415 * 0x0c NOP 1416 * 0x0d NOP 1417 * 0x0e NOP 1418 * 0x0f NOP 1419 */ 1420 if ((ofl->ofl_flags & FLG_OF_DYNAMIC) && ofl->ofl_osplt) { 1421 uchar_t *pltent; 1422 Xword val1; 1423 1424 pltent = (uchar_t *)ofl->ofl_osplt->os_outdata->d_buf; 1425 bcopy(plt0_template, pltent, sizeof (plt0_template)); 1426 1427 /* 1428 * If '-z noreloc' is specified - skip the do_reloc_ld 1429 * stage. 1430 */ 1431 if (!OFL_DO_RELOC(ofl)) 1432 return (1); 1433 1434 /* 1435 * filin: 1436 * PUSHQ GOT + 8(%rip) 1437 * 1438 * Note: 0x06 below represents the offset to the 1439 * next instruction - which is what %rip will 1440 * be pointing at. 1441 */ 1442 val1 = (ofl->ofl_osgot->os_shdr->sh_addr) + 1443 (M_GOT_XLINKMAP * M_GOT_ENTSIZE) - 1444 ofl->ofl_osplt->os_shdr->sh_addr - 0x06; 1445 1446 if (do_reloc_ld(&rdesc_r_amd64_gotpcrel, &pltent[0x02], 1447 &val1, syn_rdesc_sym_name, MSG_ORIG(MSG_SPECFIL_PLTENT), 1448 bswap, ofl->ofl_lml) == 0) { 1449 eprintf(ofl->ofl_lml, ERR_FATAL, 1450 MSG_INTL(MSG_PLT_PLT0FAIL)); 1451 return (S_ERROR); 1452 } 1453 1454 /* 1455 * filin: 1456 * JMP *GOT+16(%rip) 1457 */ 1458 val1 = (ofl->ofl_osgot->os_shdr->sh_addr) + 1459 (M_GOT_XRTLD * M_GOT_ENTSIZE) - 1460 ofl->ofl_osplt->os_shdr->sh_addr - 0x0c; 1461 1462 if (do_reloc_ld(&rdesc_r_amd64_gotpcrel, &pltent[0x08], 1463 &val1, syn_rdesc_sym_name, MSG_ORIG(MSG_SPECFIL_PLTENT), 1464 bswap, ofl->ofl_lml) == 0) { 1465 eprintf(ofl->ofl_lml, ERR_FATAL, 1466 MSG_INTL(MSG_PLT_PLT0FAIL)); 1467 return (S_ERROR); 1468 } 1469 } 1470 1471 return (1); 1472 } 1473 1474 1475 1476 /* 1477 * Template for generating "void (*)(void)" function 1478 */ 1479 static const uchar_t nullfunc_tmpl[] = { /* amd64 */ 1480 /* 0x00 */ 0x55, /* pushq %rbp */ 1481 /* 0x01 */ 0x48, 0x8b, 0xec, /* movq %rsp,%rbp */ 1482 /* 0x04 */ 0x48, 0x8b, 0xe5, /* movq %rbp,%rsp */ 1483 /* 0x07 */ 0x5d, /* popq %rbp */ 1484 /* 0x08 */ 0xc3 /* ret */ 1485 }; 1486 1487 1488 /* 1489 * Function used to provide fill padding in SHF_EXECINSTR sections 1490 * 1491 * entry: 1492 * 1493 * base - base address of section being filled 1494 * offset - starting offset for fill within memory referenced by base 1495 * cnt - # bytes to be filled 1496 * 1497 * exit: 1498 * The fill has been completed. 1499 */ 1500 static void 1501 execfill(void *base, off_t off, size_t cnt) 1502 { 1503 /* 1504 * 0x90 is an X86 NOP instruction in both 32 and 64-bit worlds. 1505 * There are no alignment constraints. 1506 */ 1507 (void) memset(off + (char *)base, 0x90, cnt); 1508 } 1509 1510 1511 /* 1512 * Return the ld_targ definition for this target. 1513 */ 1514 const Target * 1515 ld_targ_init_x86(void) 1516 { 1517 static const Target _ld_targ = { 1518 { /* Target_mach */ 1519 M_MACH, /* m_mach */ 1520 M_MACHPLUS, /* m_machplus */ 1521 M_FLAGSPLUS, /* m_flagsplus */ 1522 M_CLASS, /* m_class */ 1523 M_DATA, /* m_data */ 1524 1525 M_SEGM_ALIGN, /* m_segm_align */ 1526 M_SEGM_ORIGIN, /* m_segm_origin */ 1527 M_SEGM_AORIGIN, /* m_segm_aorigin */ 1528 M_DATASEG_PERM, /* m_dataseg_perm */ 1529 M_STACK_PERM, /* m_stack_perm */ 1530 M_WORD_ALIGN, /* m_word_align */ 1531 MSG_ORIG(MSG_PTH_RTLD_AMD64), /* m_def_interp */ 1532 1533 /* Relocation type codes */ 1534 M_R_ARRAYADDR, /* m_r_arrayaddr */ 1535 M_R_COPY, /* m_r_copy */ 1536 M_R_GLOB_DAT, /* m_r_glob_dat */ 1537 M_R_JMP_SLOT, /* m_r_jmp_slot */ 1538 M_R_NUM, /* m_r_num */ 1539 M_R_NONE, /* m_r_none */ 1540 M_R_RELATIVE, /* m_r_relative */ 1541 M_R_REGISTER, /* m_r_register */ 1542 1543 /* Relocation related constants */ 1544 M_REL_DT_COUNT, /* m_rel_dt_count */ 1545 M_REL_DT_ENT, /* m_rel_dt_ent */ 1546 M_REL_DT_SIZE, /* m_rel_dt_size */ 1547 M_REL_DT_TYPE, /* m_rel_dt_type */ 1548 M_REL_SHT_TYPE, /* m_rel_sht_type */ 1549 1550 /* GOT related constants */ 1551 M_GOT_ENTSIZE, /* m_got_entsize */ 1552 M_GOT_XNumber, /* m_got_xnumber */ 1553 1554 /* PLT related constants */ 1555 M_PLT_ALIGN, /* m_plt_align */ 1556 M_PLT_ENTSIZE, /* m_plt_entsize */ 1557 M_PLT_RESERVSZ, /* m_plt_reservsz */ 1558 M_PLT_SHF_FLAGS, /* m_plt_shf_flags */ 1559 1560 /* Section type of .eh_frame/.eh_frame_hdr sections */ 1561 SHT_AMD64_UNWIND, /* m_sht_unwind */ 1562 1563 M_DT_REGISTER, /* m_dt_register */ 1564 }, 1565 { /* Target_machid */ 1566 M_ID_ARRAY, /* id_array */ 1567 M_ID_BSS, /* id_bss */ 1568 M_ID_CAP, /* id_cap */ 1569 M_ID_CAPINFO, /* id_capinfo */ 1570 M_ID_CAPCHAIN, /* id_capchain */ 1571 M_ID_DATA, /* id_data */ 1572 M_ID_DYNAMIC, /* id_dynamic */ 1573 M_ID_DYNSORT, /* id_dynsort */ 1574 M_ID_DYNSTR, /* id_dynstr */ 1575 M_ID_DYNSYM, /* id_dynsym */ 1576 M_ID_DYNSYM_NDX, /* id_dynsym_ndx */ 1577 M_ID_GOT, /* id_got */ 1578 M_ID_UNKNOWN, /* id_gotdata (unused) */ 1579 M_ID_HASH, /* id_hash */ 1580 M_ID_INTERP, /* id_interp */ 1581 M_ID_LBSS, /* id_lbss */ 1582 M_ID_LDYNSYM, /* id_ldynsym */ 1583 M_ID_NOTE, /* id_note */ 1584 M_ID_NULL, /* id_null */ 1585 M_ID_PLT, /* id_plt */ 1586 M_ID_REL, /* id_rel */ 1587 M_ID_STRTAB, /* id_strtab */ 1588 M_ID_SYMINFO, /* id_syminfo */ 1589 M_ID_SYMTAB, /* id_symtab */ 1590 M_ID_SYMTAB_NDX, /* id_symtab_ndx */ 1591 M_ID_TEXT, /* id_text */ 1592 M_ID_TLS, /* id_tls */ 1593 M_ID_TLSBSS, /* id_tlsbss */ 1594 M_ID_UNKNOWN, /* id_unknown */ 1595 M_ID_UNWIND, /* id_unwind */ 1596 M_ID_UNWINDHDR, /* id_unwindhdr */ 1597 M_ID_USER, /* id_user */ 1598 M_ID_VERSION, /* id_version */ 1599 }, 1600 { /* Target_nullfunc */ 1601 nullfunc_tmpl, /* nf_template */ 1602 sizeof (nullfunc_tmpl), /* nf_size */ 1603 }, 1604 { /* Target_fillfunc */ 1605 execfill /* ff_execfill */ 1606 }, 1607 { /* Target_machrel */ 1608 reloc_table, 1609 1610 ld_init_rel, /* mr_init_rel */ 1611 ld_mach_eflags, /* mr_mach_eflags */ 1612 ld_mach_make_dynamic, /* mr_mach_make_dynamic */ 1613 ld_mach_update_odynamic, /* mr_mach_update_odynamic */ 1614 ld_calc_plt_addr, /* mr_calc_plt_addr */ 1615 ld_perform_outreloc, /* mr_perform_outreloc */ 1616 ld_do_activerelocs, /* mr_do_activerelocs */ 1617 ld_add_outrel, /* mr_add_outrel */ 1618 NULL, /* mr_reloc_register */ 1619 ld_reloc_local, /* mr_reloc_local */ 1620 NULL, /* mr_reloc_GOTOP */ 1621 ld_reloc_TLS, /* mr_reloc_TLS */ 1622 NULL, /* mr_assign_got */ 1623 ld_find_got_ndx, /* mr_find_got_ndx */ 1624 ld_calc_got_offset, /* mr_calc_got_offset */ 1625 ld_assign_got_ndx, /* mr_assign_got_ndx */ 1626 ld_assign_plt_ndx, /* mr_assign_plt_ndx */ 1627 NULL, /* mr_allocate_got */ 1628 ld_fillin_gotplt, /* mr_fillin_gotplt */ 1629 }, 1630 { /* Target_machsym */ 1631 NULL, /* ms_reg_check */ 1632 NULL, /* ms_mach_sym_typecheck */ 1633 NULL, /* ms_is_regsym */ 1634 NULL, /* ms_reg_find */ 1635 NULL /* ms_reg_enter */ 1636 } 1637 }; 1638 1639 return (&_ld_targ); 1640 } 1641