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 2009 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27 /* 28 * Copyright (c) 1988 AT&T 29 * All Rights Reserved 30 */ 31 32 /* 33 * x86 machine dependent and ELF file class dependent functions. 34 * Contains routines for performing function binding and symbol relocations. 35 */ 36 37 #include <stdio.h> 38 #include <sys/elf.h> 39 #include <sys/elf_386.h> 40 #include <sys/mman.h> 41 #include <dlfcn.h> 42 #include <synch.h> 43 #include <string.h> 44 #include <debug.h> 45 #include <reloc.h> 46 #include <conv.h> 47 #include "_rtld.h" 48 #include "_audit.h" 49 #include "_elf.h" 50 #include "_inline.h" 51 #include "msg.h" 52 53 extern void elf_rtbndr(Rt_map *, ulong_t, caddr_t); 54 55 int 56 elf_mach_flags_check(Rej_desc *rej, Ehdr *ehdr) 57 { 58 /* 59 * Check machine type and flags. 60 */ 61 if (ehdr->e_flags != 0) { 62 rej->rej_type = SGS_REJ_BADFLAG; 63 rej->rej_info = (uint_t)ehdr->e_flags; 64 return (0); 65 } 66 return (1); 67 } 68 69 void 70 ldso_plt_init(Rt_map *lmp) 71 { 72 /* 73 * There is no need to analyze ld.so because we don't map in any of 74 * its dependencies. However we may map these dependencies in later 75 * (as if ld.so had dlopened them), so initialize the plt and the 76 * permission information. 77 */ 78 if (PLTGOT(lmp)) 79 elf_plt_init((PLTGOT(lmp)), (caddr_t)lmp); 80 } 81 82 static const uchar_t dyn_plt_template[] = { 83 /* 0x00 */ 0x55, /* pushl %ebp */ 84 /* 0x01 */ 0x8b, 0xec, /* movl %esp, %ebp */ 85 /* 0x03 */ 0x68, 0x00, 0x00, 0x00, 0x00, /* pushl trace_fields */ 86 /* 0x08 */ 0xe9, 0xfc, 0xff, 0xff, 0xff, 0xff /* jmp elf_plt_trace */ 87 }; 88 int dyn_plt_ent_size = sizeof (dyn_plt_template); 89 90 /* 91 * the dynamic plt entry is: 92 * 93 * pushl %ebp 94 * movl %esp, %ebp 95 * pushl tfp 96 * jmp elf_plt_trace 97 * dyn_data: 98 * .align 4 99 * uintptr_t reflmp 100 * uintptr_t deflmp 101 * uint_t symndx 102 * uint_t sb_flags 103 * Sym symdef 104 */ 105 static caddr_t 106 elf_plt_trace_write(uint_t roffset, Rt_map *rlmp, Rt_map *dlmp, Sym *sym, 107 uint_t symndx, uint_t pltndx, caddr_t to, uint_t sb_flags, int *fail) 108 { 109 extern int elf_plt_trace(); 110 ulong_t got_entry; 111 uchar_t *dyn_plt; 112 uintptr_t *dyndata; 113 114 /* 115 * We only need to add the glue code if there is an auditing 116 * library that is interested in this binding. 117 */ 118 dyn_plt = (uchar_t *)((uintptr_t)AUDINFO(rlmp)->ai_dynplts + 119 (pltndx * dyn_plt_ent_size)); 120 121 /* 122 * Have we initialized this dynamic plt entry yet? If we haven't do it 123 * now. Otherwise this function has been called before, but from a 124 * different plt (ie. from another shared object). In that case 125 * we just set the plt to point to the new dyn_plt. 126 */ 127 if (*dyn_plt == 0) { 128 Sym *symp; 129 Word symvalue; 130 Lm_list *lml = LIST(rlmp); 131 132 (void) memcpy((void *)dyn_plt, dyn_plt_template, 133 sizeof (dyn_plt_template)); 134 dyndata = (uintptr_t *)((uintptr_t)dyn_plt + 135 ROUND(sizeof (dyn_plt_template), M_WORD_ALIGN)); 136 137 /* 138 * relocate: 139 * pushl dyn_data 140 */ 141 symvalue = (Word)dyndata; 142 if (do_reloc_rtld(R_386_32, &dyn_plt[4], &symvalue, 143 MSG_ORIG(MSG_SYM_LADYNDATA), 144 MSG_ORIG(MSG_SPECFIL_DYNPLT), lml) == 0) { 145 *fail = 1; 146 return (0); 147 } 148 149 /* 150 * jmps are relative, so I need to figure out the relative 151 * address to elf_plt_trace. 152 * 153 * relocating: 154 * jmp elf_plt_trace 155 */ 156 symvalue = (ulong_t)(elf_plt_trace) - (ulong_t)(dyn_plt + 9); 157 if (do_reloc_rtld(R_386_PC32, &dyn_plt[9], &symvalue, 158 MSG_ORIG(MSG_SYM_ELFPLTTRACE), 159 MSG_ORIG(MSG_SPECFIL_DYNPLT), lml) == 0) { 160 *fail = 1; 161 return (0); 162 } 163 164 *dyndata++ = (uintptr_t)rlmp; 165 *dyndata++ = (uintptr_t)dlmp; 166 *dyndata++ = (uint_t)symndx; 167 *dyndata++ = (uint_t)sb_flags; 168 symp = (Sym *)dyndata; 169 *symp = *sym; 170 symp->st_name += (Word)STRTAB(dlmp); 171 symp->st_value = (Addr)to; 172 } 173 174 got_entry = (ulong_t)roffset; 175 *(ulong_t *)got_entry = (ulong_t)dyn_plt; 176 return ((caddr_t)dyn_plt); 177 } 178 179 /* 180 * Function binding routine - invoked on the first call to a function through 181 * the procedure linkage table; 182 * passes first through an assembly language interface. 183 * 184 * Takes the offset into the relocation table of the associated 185 * relocation entry and the address of the link map (rt_private_map struct) 186 * for the entry. 187 * 188 * Returns the address of the function referenced after re-writing the PLT 189 * entry to invoke the function directly. 190 * 191 * On error, causes process to terminate with a signal. 192 */ 193 ulong_t 194 elf_bndr(Rt_map *lmp, ulong_t reloff, caddr_t from) 195 { 196 Rt_map *nlmp, *llmp; 197 ulong_t addr, symval, rsymndx; 198 char *name; 199 Rel *rptr; 200 Sym *rsym, *nsym; 201 uint_t binfo, sb_flags = 0, dbg_class; 202 Slookup sl; 203 int entry, lmflags; 204 Lm_list *lml; 205 206 /* 207 * For compatibility with libthread (TI_VERSION 1) we track the entry 208 * value. A zero value indicates we have recursed into ld.so.1 to 209 * further process a locking request. Under this recursion we disable 210 * tsort and cleanup activities. 211 */ 212 entry = enter(0); 213 214 lml = LIST(lmp); 215 if ((lmflags = lml->lm_flags) & LML_FLG_RTLDLM) { 216 dbg_class = dbg_desc->d_class; 217 dbg_desc->d_class = 0; 218 } 219 220 /* 221 * Perform some basic sanity checks. If we didn't get a load map or 222 * the relocation offset is invalid then its possible someone has walked 223 * over the .got entries or jumped to plt0 out of the blue. 224 */ 225 if (!lmp || ((reloff % sizeof (Rel)) != 0)) { 226 Conv_inv_buf_t inv_buf; 227 228 eprintf(lml, ERR_FATAL, MSG_INTL(MSG_REL_PLTREF), 229 conv_reloc_386_type(R_386_JMP_SLOT, 0, &inv_buf), 230 EC_NATPTR(lmp), EC_XWORD(reloff), EC_NATPTR(from)); 231 rtldexit(lml, 1); 232 } 233 234 /* 235 * Use relocation entry to get symbol table entry and symbol name. 236 */ 237 addr = (ulong_t)JMPREL(lmp); 238 rptr = (Rel *)(addr + reloff); 239 rsymndx = ELF_R_SYM(rptr->r_info); 240 rsym = (Sym *)((ulong_t)SYMTAB(lmp) + (rsymndx * SYMENT(lmp))); 241 name = (char *)(STRTAB(lmp) + rsym->st_name); 242 243 /* 244 * Determine the last link-map of this list, this'll be the starting 245 * point for any tsort() processing. 246 */ 247 llmp = lml->lm_tail; 248 249 /* 250 * Find definition for symbol. Initialize the symbol lookup data 251 * structure. 252 */ 253 SLOOKUP_INIT(sl, name, lmp, lml->lm_head, ld_entry_cnt, 0, 254 rsymndx, rsym, 0, LKUP_DEFT); 255 256 if ((nsym = lookup_sym(&sl, &nlmp, &binfo, NULL)) == 0) { 257 eprintf(lml, ERR_FATAL, MSG_INTL(MSG_REL_NOSYM), NAME(lmp), 258 demangle(name)); 259 rtldexit(lml, 1); 260 } 261 262 symval = nsym->st_value; 263 if (!(FLAGS(nlmp) & FLG_RT_FIXED) && 264 (nsym->st_shndx != SHN_ABS)) 265 symval += ADDR(nlmp); 266 if ((lmp != nlmp) && ((FLAGS1(nlmp) & FL1_RT_NOINIFIN) == 0)) { 267 /* 268 * Record that this new link map is now bound to the caller. 269 */ 270 if (bind_one(lmp, nlmp, BND_REFER) == 0) 271 rtldexit(lml, 1); 272 } 273 274 if ((lml->lm_tflags | AFLAGS(lmp)) & LML_TFLG_AUD_SYMBIND) { 275 uint_t symndx = (((uintptr_t)nsym - 276 (uintptr_t)SYMTAB(nlmp)) / SYMENT(nlmp)); 277 symval = audit_symbind(lmp, nlmp, nsym, symndx, symval, 278 &sb_flags); 279 } 280 281 if (!(rtld_flags & RT_FL_NOBIND)) { 282 addr = rptr->r_offset; 283 if (!(FLAGS(lmp) & FLG_RT_FIXED)) 284 addr += ADDR(lmp); 285 if (((lml->lm_tflags | AFLAGS(lmp)) & 286 (LML_TFLG_AUD_PLTENTER | LML_TFLG_AUD_PLTEXIT)) && 287 AUDINFO(lmp)->ai_dynplts) { 288 int fail = 0; 289 uint_t pltndx = reloff / sizeof (Rel); 290 uint_t symndx = (((uintptr_t)nsym - 291 (uintptr_t)SYMTAB(nlmp)) / SYMENT(nlmp)); 292 293 symval = (ulong_t)elf_plt_trace_write(addr, lmp, nlmp, 294 nsym, symndx, pltndx, (caddr_t)symval, sb_flags, 295 &fail); 296 if (fail) 297 rtldexit(lml, 1); 298 } else { 299 /* 300 * Write standard PLT entry to jump directly 301 * to newly bound function. 302 */ 303 *(ulong_t *)addr = symval; 304 } 305 } 306 307 /* 308 * Print binding information and rebuild PLT entry. 309 */ 310 DBG_CALL(Dbg_bind_global(lmp, (Addr)from, (Off)(from - ADDR(lmp)), 311 (Xword)(reloff / sizeof (Rel)), PLT_T_FULL, nlmp, (Addr)symval, 312 nsym->st_value, name, binfo)); 313 314 /* 315 * Complete any processing for newly loaded objects. Note we don't 316 * know exactly where any new objects are loaded (we know the object 317 * that supplied the symbol, but others may have been loaded lazily as 318 * we searched for the symbol), so sorting starts from the last 319 * link-map know on entry to this routine. 320 */ 321 if (entry) 322 load_completion(llmp); 323 324 /* 325 * Some operations like dldump() or dlopen()'ing a relocatable object 326 * result in objects being loaded on rtld's link-map, make sure these 327 * objects are initialized also. 328 */ 329 if ((LIST(nlmp)->lm_flags & LML_FLG_RTLDLM) && LIST(nlmp)->lm_init) 330 load_completion(nlmp); 331 332 /* 333 * Make sure the object to which we've bound has had it's .init fired. 334 * Cleanup before return to user code. 335 */ 336 if (entry) { 337 is_dep_init(nlmp, lmp); 338 leave(lml, 0); 339 } 340 341 if (lmflags & LML_FLG_RTLDLM) 342 dbg_desc->d_class = dbg_class; 343 344 return (symval); 345 } 346 347 /* 348 * Read and process the relocations for one link object, we assume all 349 * relocation sections for loadable segments are stored contiguously in 350 * the file. 351 */ 352 int 353 elf_reloc(Rt_map *lmp, uint_t plt, int *in_nfavl, APlist **textrel) 354 { 355 ulong_t relbgn, relend, relsiz, basebgn, pltbgn, pltend; 356 ulong_t _pltbgn, _pltend; 357 ulong_t dsymndx, roffset, rsymndx, psymndx = 0; 358 uchar_t rtype; 359 long value, pvalue; 360 Sym *symref, *psymref, *symdef, *psymdef; 361 char *name, *pname; 362 Rt_map *_lmp, *plmp; 363 int ret = 1, noplt = 0; 364 int relacount = RELACOUNT(lmp), plthint = 0; 365 Rel *rel; 366 uint_t binfo, pbinfo; 367 APlist *bound = NULL; 368 369 /* 370 * Although only necessary for lazy binding, initialize the first 371 * global offset entry to go to elf_rtbndr(). dbx(1) seems 372 * to find this useful. 373 */ 374 if ((plt == 0) && PLTGOT(lmp)) { 375 mmapobj_result_t *mpp; 376 377 /* 378 * Make sure the segment is writable. 379 */ 380 if ((((mpp = 381 find_segment((caddr_t)PLTGOT(lmp), lmp)) != NULL) && 382 ((mpp->mr_prot & PROT_WRITE) == 0)) && 383 ((set_prot(lmp, mpp, 1) == 0) || 384 (aplist_append(textrel, mpp, AL_CNT_TEXTREL) == NULL))) 385 return (0); 386 387 elf_plt_init(PLTGOT(lmp), (caddr_t)lmp); 388 } 389 390 /* 391 * Initialize the plt start and end addresses. 392 */ 393 if ((pltbgn = (ulong_t)JMPREL(lmp)) != 0) 394 pltend = pltbgn + (ulong_t)(PLTRELSZ(lmp)); 395 396 relsiz = (ulong_t)(RELENT(lmp)); 397 basebgn = ADDR(lmp); 398 399 if (PLTRELSZ(lmp)) 400 plthint = PLTRELSZ(lmp) / relsiz; 401 402 /* 403 * If we've been called upon to promote an RTLD_LAZY object to an 404 * RTLD_NOW then we're only interested in scaning the .plt table. 405 * An uninitialized .plt is the case where the associated got entry 406 * points back to the plt itself. Determine the range of the real .plt 407 * entries using the _PROCEDURE_LINKAGE_TABLE_ symbol. 408 */ 409 if (plt) { 410 Slookup sl; 411 412 relbgn = pltbgn; 413 relend = pltend; 414 if (!relbgn || (relbgn == relend)) 415 return (1); 416 417 /* 418 * Initialize the symbol lookup data structure. 419 */ 420 SLOOKUP_INIT(sl, MSG_ORIG(MSG_SYM_PLT), lmp, lmp, ld_entry_cnt, 421 elf_hash(MSG_ORIG(MSG_SYM_PLT)), 0, 0, 0, LKUP_DEFT); 422 423 if ((symdef = elf_find_sym(&sl, &_lmp, &binfo, NULL)) == 0) 424 return (1); 425 426 _pltbgn = symdef->st_value; 427 if (!(FLAGS(lmp) & FLG_RT_FIXED) && 428 (symdef->st_shndx != SHN_ABS)) 429 _pltbgn += basebgn; 430 _pltend = _pltbgn + (((PLTRELSZ(lmp) / relsiz)) * 431 M_PLT_ENTSIZE) + M_PLT_RESERVSZ; 432 433 } else { 434 /* 435 * The relocation sections appear to the run-time linker as a 436 * single table. Determine the address of the beginning and end 437 * of this table. There are two different interpretations of 438 * the ABI at this point: 439 * 440 * o The REL table and its associated RELSZ indicate the 441 * concatenation of *all* relocation sections (this is the 442 * model our link-editor constructs). 443 * 444 * o The REL table and its associated RELSZ indicate the 445 * concatenation of all *but* the .plt relocations. These 446 * relocations are specified individually by the JMPREL and 447 * PLTRELSZ entries. 448 * 449 * Determine from our knowledege of the relocation range and 450 * .plt range, the range of the total relocation table. Note 451 * that one other ABI assumption seems to be that the .plt 452 * relocations always follow any other relocations, the 453 * following range checking drops that assumption. 454 */ 455 relbgn = (ulong_t)(REL(lmp)); 456 relend = relbgn + (ulong_t)(RELSZ(lmp)); 457 if (pltbgn) { 458 if (!relbgn || (relbgn > pltbgn)) 459 relbgn = pltbgn; 460 if (!relbgn || (relend < pltend)) 461 relend = pltend; 462 } 463 } 464 if (!relbgn || (relbgn == relend)) { 465 DBG_CALL(Dbg_reloc_run(lmp, 0, plt, DBG_REL_NONE)); 466 return (1); 467 } 468 DBG_CALL(Dbg_reloc_run(lmp, M_REL_SHT_TYPE, plt, DBG_REL_START)); 469 470 /* 471 * If we're processing a dynamic executable in lazy mode there is no 472 * need to scan the .rel.plt table, however if we're processing a shared 473 * object in lazy mode the .got addresses associated to each .plt must 474 * be relocated to reflect the location of the shared object. 475 */ 476 if (pltbgn && ((MODE(lmp) & RTLD_NOW) == 0) && 477 (FLAGS(lmp) & FLG_RT_FIXED)) 478 noplt = 1; 479 480 /* 481 * Loop through relocations. 482 */ 483 while (relbgn < relend) { 484 mmapobj_result_t *mpp; 485 uint_t sb_flags = 0; 486 487 rtype = ELF_R_TYPE(((Rel *)relbgn)->r_info, M_MACH); 488 489 /* 490 * If this is a RELATIVE relocation in a shared object (the 491 * common case), and if we are not debugging, then jump into a 492 * tighter relocation loop (elf_reloc_relative). 493 */ 494 if ((rtype == R_386_RELATIVE) && 495 ((FLAGS(lmp) & FLG_RT_FIXED) == 0) && (DBG_ENABLED == 0)) { 496 if (relacount) { 497 relbgn = elf_reloc_relative_count(relbgn, 498 relacount, relsiz, basebgn, lmp, textrel); 499 relacount = 0; 500 } else { 501 relbgn = elf_reloc_relative(relbgn, relend, 502 relsiz, basebgn, lmp, textrel); 503 } 504 if (relbgn >= relend) 505 break; 506 rtype = ELF_R_TYPE(((Rel *)relbgn)->r_info, M_MACH); 507 } 508 509 roffset = ((Rel *)relbgn)->r_offset; 510 511 /* 512 * If this is a shared object, add the base address to offset. 513 */ 514 if (!(FLAGS(lmp) & FLG_RT_FIXED)) { 515 /* 516 * If we're processing lazy bindings, we have to step 517 * through the plt entries and add the base address 518 * to the corresponding got entry. 519 */ 520 if (plthint && (plt == 0) && 521 (rtype == R_386_JMP_SLOT) && 522 ((MODE(lmp) & RTLD_NOW) == 0)) { 523 relbgn = elf_reloc_relative_count(relbgn, 524 plthint, relsiz, basebgn, lmp, textrel); 525 plthint = 0; 526 continue; 527 } 528 roffset += basebgn; 529 } 530 531 rsymndx = ELF_R_SYM(((Rel *)relbgn)->r_info); 532 rel = (Rel *)relbgn; 533 relbgn += relsiz; 534 535 /* 536 * Optimizations. 537 */ 538 if (rtype == R_386_NONE) 539 continue; 540 if (noplt && ((ulong_t)rel >= pltbgn) && 541 ((ulong_t)rel < pltend)) { 542 relbgn = pltend; 543 continue; 544 } 545 546 /* 547 * If we're promoting plts, determine if this one has already 548 * been written. 549 */ 550 if (plt && ((*(ulong_t *)roffset < _pltbgn) || 551 (*(ulong_t *)roffset > _pltend))) 552 continue; 553 554 /* 555 * If this relocation is not against part of the image 556 * mapped into memory we skip it. 557 */ 558 if ((mpp = find_segment((caddr_t)roffset, lmp)) == NULL) { 559 elf_reloc_bad(lmp, (void *)rel, rtype, roffset, 560 rsymndx); 561 continue; 562 } 563 564 binfo = 0; 565 /* 566 * If a symbol index is specified then get the symbol table 567 * entry, locate the symbol definition, and determine its 568 * address. 569 */ 570 if (rsymndx) { 571 /* 572 * Get the local symbol table entry. 573 */ 574 symref = (Sym *)((ulong_t)SYMTAB(lmp) + 575 (rsymndx * SYMENT(lmp))); 576 577 /* 578 * If this is a local symbol, just use the base address. 579 * (we should have no local relocations in the 580 * executable). 581 */ 582 if (ELF_ST_BIND(symref->st_info) == STB_LOCAL) { 583 value = basebgn; 584 name = (char *)0; 585 586 /* 587 * Special case TLS relocations. 588 */ 589 if (rtype == R_386_TLS_DTPMOD32) { 590 /* 591 * Use the TLS modid. 592 */ 593 value = TLSMODID(lmp); 594 595 } else if (rtype == R_386_TLS_TPOFF) { 596 if ((value = elf_static_tls(lmp, symref, 597 rel, rtype, 0, roffset, 0)) == 0) { 598 ret = 0; 599 break; 600 } 601 } 602 } else { 603 /* 604 * If the symbol index is equal to the previous 605 * symbol index relocation we processed then 606 * reuse the previous values. (Note that there 607 * have been cases where a relocation exists 608 * against a copy relocation symbol, our ld(1) 609 * should optimize this away, but make sure we 610 * don't use the same symbol information should 611 * this case exist). 612 */ 613 if ((rsymndx == psymndx) && 614 (rtype != R_386_COPY)) { 615 /* LINTED */ 616 if (psymdef == 0) { 617 DBG_CALL(Dbg_bind_weak(lmp, 618 (Addr)roffset, (Addr) 619 (roffset - basebgn), name)); 620 continue; 621 } 622 /* LINTED */ 623 value = pvalue; 624 /* LINTED */ 625 name = pname; 626 /* LINTED */ 627 symdef = psymdef; 628 /* LINTED */ 629 symref = psymref; 630 /* LINTED */ 631 _lmp = plmp; 632 /* LINTED */ 633 binfo = pbinfo; 634 635 if ((LIST(_lmp)->lm_tflags | 636 AFLAGS(_lmp)) & 637 LML_TFLG_AUD_SYMBIND) { 638 value = audit_symbind(lmp, _lmp, 639 /* LINTED */ 640 symdef, dsymndx, value, 641 &sb_flags); 642 } 643 } else { 644 Slookup sl; 645 646 /* 647 * Lookup the symbol definition. 648 * Initialize the symbol lookup data 649 * structure. 650 */ 651 name = (char *)(STRTAB(lmp) + 652 symref->st_name); 653 654 SLOOKUP_INIT(sl, name, lmp, 0, 655 ld_entry_cnt, 0, rsymndx, symref, 656 rtype, LKUP_STDRELOC); 657 658 symdef = lookup_sym(&sl, &_lmp, 659 &binfo, in_nfavl); 660 661 /* 662 * If the symbol is not found and the 663 * reference was not to a weak symbol, 664 * report an error. Weak references 665 * may be unresolved. 666 */ 667 /* BEGIN CSTYLED */ 668 if (symdef == 0) { 669 if (sl.sl_bind != STB_WEAK) { 670 if (elf_reloc_error(lmp, name, 671 rel, binfo)) 672 continue; 673 674 ret = 0; 675 break; 676 677 } else { 678 psymndx = rsymndx; 679 psymdef = 0; 680 681 DBG_CALL(Dbg_bind_weak(lmp, 682 (Addr)roffset, (Addr) 683 (roffset - basebgn), name)); 684 continue; 685 } 686 } 687 /* END CSTYLED */ 688 689 /* 690 * If symbol was found in an object 691 * other than the referencing object 692 * then record the binding. 693 */ 694 if ((lmp != _lmp) && ((FLAGS1(_lmp) & 695 FL1_RT_NOINIFIN) == 0)) { 696 if (aplist_test(&bound, _lmp, 697 AL_CNT_RELBIND) == 0) { 698 ret = 0; 699 break; 700 } 701 } 702 703 /* 704 * Calculate the location of definition; 705 * symbol value plus base address of 706 * containing shared object. 707 */ 708 if (IS_SIZE(rtype)) 709 value = symdef->st_size; 710 else 711 value = symdef->st_value; 712 713 if (!(FLAGS(_lmp) & FLG_RT_FIXED) && 714 !(IS_SIZE(rtype)) && 715 (symdef->st_shndx != SHN_ABS) && 716 (ELF_ST_TYPE(symdef->st_info) != 717 STT_TLS)) 718 value += ADDR(_lmp); 719 720 /* 721 * Retain this symbol index and the 722 * value in case it can be used for the 723 * subsequent relocations. 724 */ 725 if (rtype != R_386_COPY) { 726 psymndx = rsymndx; 727 pvalue = value; 728 pname = name; 729 psymdef = symdef; 730 psymref = symref; 731 plmp = _lmp; 732 pbinfo = binfo; 733 } 734 if ((LIST(_lmp)->lm_tflags | 735 AFLAGS(_lmp)) & 736 LML_TFLG_AUD_SYMBIND) { 737 dsymndx = (((uintptr_t)symdef - 738 (uintptr_t)SYMTAB(_lmp)) / 739 SYMENT(_lmp)); 740 value = audit_symbind(lmp, _lmp, 741 symdef, dsymndx, value, 742 &sb_flags); 743 } 744 } 745 746 /* 747 * If relocation is PC-relative, subtract 748 * offset address. 749 */ 750 if (IS_PC_RELATIVE(rtype)) 751 value -= roffset; 752 753 /* 754 * Special case TLS relocations. 755 */ 756 if (rtype == R_386_TLS_DTPMOD32) { 757 /* 758 * Relocation value is the TLS modid. 759 */ 760 value = TLSMODID(_lmp); 761 762 } else if (rtype == R_386_TLS_TPOFF) { 763 if ((value = elf_static_tls(_lmp, 764 symdef, rel, rtype, name, roffset, 765 value)) == 0) { 766 ret = 0; 767 break; 768 } 769 } 770 } 771 } else { 772 /* 773 * Special cases. 774 */ 775 if (rtype == R_386_TLS_DTPMOD32) { 776 /* 777 * TLS relocation value is the TLS modid. 778 */ 779 value = TLSMODID(lmp); 780 } else 781 value = basebgn; 782 name = (char *)0; 783 } 784 785 DBG_CALL(Dbg_reloc_in(LIST(lmp), ELF_DBG_RTLD, M_MACH, 786 M_REL_SHT_TYPE, rel, NULL, 0, name)); 787 788 /* 789 * Make sure the segment is writable. 790 */ 791 if (((mpp->mr_prot & PROT_WRITE) == 0) && 792 ((set_prot(lmp, mpp, 1) == 0) || 793 (aplist_append(textrel, mpp, AL_CNT_TEXTREL) == NULL))) { 794 ret = 0; 795 break; 796 } 797 798 /* 799 * Call relocation routine to perform required relocation. 800 */ 801 switch (rtype) { 802 case R_386_COPY: 803 if (elf_copy_reloc(name, symref, lmp, (void *)roffset, 804 symdef, _lmp, (const void *)value) == 0) 805 ret = 0; 806 break; 807 case R_386_JMP_SLOT: 808 if (((LIST(lmp)->lm_tflags | AFLAGS(lmp)) & 809 (LML_TFLG_AUD_PLTENTER | LML_TFLG_AUD_PLTEXIT)) && 810 AUDINFO(lmp)->ai_dynplts) { 811 int fail = 0; 812 int pltndx = (((ulong_t)rel - 813 (uintptr_t)JMPREL(lmp)) / relsiz); 814 int symndx = (((uintptr_t)symdef - 815 (uintptr_t)SYMTAB(_lmp)) / SYMENT(_lmp)); 816 817 (void) elf_plt_trace_write(roffset, lmp, _lmp, 818 symdef, symndx, pltndx, (caddr_t)value, 819 sb_flags, &fail); 820 if (fail) 821 ret = 0; 822 } else { 823 /* 824 * Write standard PLT entry to jump directly 825 * to newly bound function. 826 */ 827 DBG_CALL(Dbg_reloc_apply_val(LIST(lmp), 828 ELF_DBG_RTLD, (Xword)roffset, 829 (Xword)value)); 830 *(ulong_t *)roffset = value; 831 } 832 break; 833 default: 834 /* 835 * Write the relocation out. 836 */ 837 if (do_reloc_rtld(rtype, (uchar_t *)roffset, 838 (Word *)&value, name, NAME(lmp), LIST(lmp)) == 0) 839 ret = 0; 840 841 DBG_CALL(Dbg_reloc_apply_val(LIST(lmp), ELF_DBG_RTLD, 842 (Xword)roffset, (Xword)value)); 843 } 844 845 if ((ret == 0) && 846 ((LIST(lmp)->lm_flags & LML_FLG_TRC_WARN) == 0)) 847 break; 848 849 if (binfo) { 850 DBG_CALL(Dbg_bind_global(lmp, (Addr)roffset, 851 (Off)(roffset - basebgn), (Xword)(-1), PLT_T_FULL, 852 _lmp, (Addr)value, symdef->st_value, name, binfo)); 853 } 854 } 855 856 return (relocate_finish(lmp, bound, ret)); 857 } 858 859 /* 860 * Initialize the first few got entries so that function calls go to 861 * elf_rtbndr: 862 * 863 * GOT[GOT_XLINKMAP] = the address of the link map 864 * GOT[GOT_XRTLD] = the address of rtbinder 865 */ 866 void 867 elf_plt_init(void *got, caddr_t l) 868 { 869 uint_t *_got; 870 /* LINTED */ 871 Rt_map *lmp = (Rt_map *)l; 872 873 _got = (uint_t *)got + M_GOT_XLINKMAP; 874 *_got = (uint_t)lmp; 875 _got = (uint_t *)got + M_GOT_XRTLD; 876 *_got = (uint_t)elf_rtbndr; 877 } 878 879 /* 880 * For SVR4 Intel compatability. USL uses /usr/lib/libc.so.1 as the run-time 881 * linker, so the interpreter's address will differ from /usr/lib/ld.so.1. 882 * Further, USL has special _iob[] and _ctype[] processing that makes up for the 883 * fact that these arrays do not have associated copy relocations. So we try 884 * and make up for that here. Any relocations found will be added to the global 885 * copy relocation list and will be processed in setup(). 886 */ 887 static int 888 _elf_copy_reloc(const char *name, Rt_map *rlmp, Rt_map *dlmp) 889 { 890 Sym *symref, *symdef; 891 caddr_t ref, def; 892 Rt_map *_lmp; 893 Rel rel; 894 Slookup sl; 895 uint_t binfo; 896 897 /* 898 * Determine if the special symbol exists as a reference in the dynamic 899 * executable, and that an associated definition exists in libc.so.1. 900 * 901 * Initialize the symbol lookup data structure. 902 */ 903 SLOOKUP_INIT(sl, name, rlmp, rlmp, ld_entry_cnt, 0, 0, 0, 0, 904 LKUP_FIRST); 905 906 if ((symref = lookup_sym(&sl, &_lmp, &binfo, NULL)) == 0) 907 return (1); 908 909 sl.sl_imap = dlmp; 910 sl.sl_flags = LKUP_DEFT; 911 912 if ((symdef = lookup_sym(&sl, &_lmp, &binfo, NULL)) == 0) 913 return (1); 914 if (strcmp(NAME(_lmp), MSG_ORIG(MSG_PTH_LIBC))) 915 return (1); 916 917 /* 918 * Determine the reference and definition addresses. 919 */ 920 ref = (void *)(symref->st_value); 921 if (!(FLAGS(rlmp) & FLG_RT_FIXED)) 922 ref += ADDR(rlmp); 923 def = (void *)(symdef->st_value); 924 if (!(FLAGS(_lmp) & FLG_RT_FIXED)) 925 def += ADDR(_lmp); 926 927 /* 928 * Set up a relocation entry for debugging and call the generic copy 929 * relocation function to provide symbol size error checking and to 930 * record the copy relocation that must be performed. 931 */ 932 rel.r_offset = (Addr)ref; 933 rel.r_info = (Word)R_386_COPY; 934 DBG_CALL(Dbg_reloc_in(LIST(rlmp), ELF_DBG_RTLD, M_MACH, M_REL_SHT_TYPE, 935 &rel, NULL, 0, name)); 936 937 return (elf_copy_reloc((char *)name, symref, rlmp, (void *)ref, symdef, 938 _lmp, (void *)def)); 939 } 940 941 int 942 elf_copy_gen(Rt_map *lmp) 943 { 944 if (interp && ((ulong_t)interp->i_faddr != 945 r_debug.rtd_rdebug.r_ldbase) && 946 !(strcmp(interp->i_name, MSG_ORIG(MSG_PTH_LIBC)))) { 947 948 DBG_CALL(Dbg_reloc_run(lmp, M_REL_SHT_TYPE, 0, 949 DBG_REL_START)); 950 951 if (_elf_copy_reloc(MSG_ORIG(MSG_SYM_CTYPE), lmp, 952 (Rt_map *)NEXT(lmp)) == 0) 953 return (0); 954 if (_elf_copy_reloc(MSG_ORIG(MSG_SYM_IOB), lmp, 955 (Rt_map *)NEXT(lmp)) == 0) 956 return (0); 957 } 958 return (1); 959 } 960 961 /* 962 * Plt writing interface to allow debugging initialization to be generic. 963 */ 964 Pltbindtype 965 /* ARGSUSED1 */ 966 elf_plt_write(uintptr_t addr, uintptr_t vaddr, void *rptr, uintptr_t symval, 967 Xword pltndx) 968 { 969 Rel *rel = (Rel*)rptr; 970 uintptr_t pltaddr; 971 972 pltaddr = addr + rel->r_offset; 973 *(ulong_t *)pltaddr = (ulong_t)symval; 974 DBG_CALL(pltcntfull++); 975 return (PLT_T_FULL); 976 } 977 978 /* 979 * Provide a machine specific interface to the conversion routine. By calling 980 * the machine specific version, rather than the generic version, we insure that 981 * the data tables/strings for all known machine versions aren't dragged into 982 * ld.so.1. 983 */ 984 const char * 985 _conv_reloc_type(uint_t rel) 986 { 987 static Conv_inv_buf_t inv_buf; 988 989 return (conv_reloc_386_type(rel, 0, &inv_buf)); 990 } 991