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) 1988 AT&T 24 * All Rights Reserved 25 * 26 * Copyright 2007 Sun Microsystems, Inc. All rights reserved. 27 * Use is subject to license terms. 28 */ 29 #pragma ident "%Z%%M% %I% %E% SMI" 30 31 /* 32 * x86 machine dependent and ELF file class dependent functions. 33 * Contains routines for performing function binding and symbol relocations. 34 */ 35 #include "_synonyms.h" 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 "msg.h" 51 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 /* 181 * Function binding routine - invoked on the first call to a function through 182 * the procedure linkage table; 183 * passes first through an assembly language interface. 184 * 185 * Takes the offset into the relocation table of the associated 186 * relocation entry and the address of the link map (rt_private_map struct) 187 * for the entry. 188 * 189 * Returns the address of the function referenced after re-writing the PLT 190 * entry to invoke the function directly. 191 * 192 * On error, causes process to terminate with a signal. 193 */ 194 ulong_t 195 elf_bndr(Rt_map *lmp, ulong_t reloff, caddr_t from) 196 { 197 Rt_map *nlmp, *llmp; 198 ulong_t addr, symval, rsymndx; 199 char *name; 200 Rel *rptr; 201 Sym *rsym, *nsym; 202 uint_t binfo, sb_flags = 0, dbg_class; 203 Slookup sl; 204 int entry, lmflags; 205 Lm_list *lml; 206 207 /* 208 * For compatibility with libthread (TI_VERSION 1) we track the entry 209 * value. A zero value indicates we have recursed into ld.so.1 to 210 * further process a locking request. Under this recursion we disable 211 * tsort and cleanup activities. 212 */ 213 entry = enter(); 214 215 lml = LIST(lmp); 216 if ((lmflags = lml->lm_flags) & LML_FLG_RTLDLM) { 217 dbg_class = dbg_desc->d_class; 218 dbg_desc->d_class = 0; 219 } 220 221 /* 222 * Perform some basic sanity checks. If we didn't get a load map or 223 * the relocation offset is invalid then its possible someone has walked 224 * over the .got entries or jumped to plt0 out of the blue. 225 */ 226 if (!lmp || ((reloff % sizeof (Rel)) != 0)) { 227 Conv_inv_buf_t inv_buf; 228 229 eprintf(lml, ERR_FATAL, MSG_INTL(MSG_REL_PLTREF), 230 conv_reloc_386_type(R_386_JMP_SLOT, 0, &inv_buf), 231 EC_NATPTR(lmp), EC_XWORD(reloff), EC_NATPTR(from)); 232 rtldexit(lml, 1); 233 } 234 235 /* 236 * Use relocation entry to get symbol table entry and symbol name. 237 */ 238 addr = (ulong_t)JMPREL(lmp); 239 rptr = (Rel *)(addr + reloff); 240 rsymndx = ELF_R_SYM(rptr->r_info); 241 rsym = (Sym *)((ulong_t)SYMTAB(lmp) + (rsymndx * SYMENT(lmp))); 242 name = (char *)(STRTAB(lmp) + rsym->st_name); 243 244 /* 245 * Determine the last link-map of this list, this'll be the starting 246 * point for any tsort() processing. 247 */ 248 llmp = lml->lm_tail; 249 250 /* 251 * Find definition for symbol. 252 */ 253 sl.sl_name = name; 254 sl.sl_cmap = lmp; 255 sl.sl_imap = lml->lm_head; 256 sl.sl_hash = 0; 257 sl.sl_rsymndx = rsymndx; 258 sl.sl_rsym = rsym; 259 sl.sl_flags = LKUP_DEFT; 260 261 if ((nsym = lookup_sym(&sl, &nlmp, &binfo)) == 0) { 262 eprintf(lml, ERR_FATAL, MSG_INTL(MSG_REL_NOSYM), NAME(lmp), 263 demangle(name)); 264 rtldexit(lml, 1); 265 } 266 267 symval = nsym->st_value; 268 if (!(FLAGS(nlmp) & FLG_RT_FIXED) && 269 (nsym->st_shndx != SHN_ABS)) 270 symval += ADDR(nlmp); 271 if ((lmp != nlmp) && ((FLAGS1(nlmp) & FL1_RT_NOINIFIN) == 0)) { 272 /* 273 * Record that this new link map is now bound to the caller. 274 */ 275 if (bind_one(lmp, nlmp, BND_REFER) == 0) 276 rtldexit(lml, 1); 277 } 278 279 if ((lml->lm_tflags | FLAGS1(lmp)) & LML_TFLG_AUD_SYMBIND) { 280 uint_t symndx = (((uintptr_t)nsym - 281 (uintptr_t)SYMTAB(nlmp)) / SYMENT(nlmp)); 282 symval = audit_symbind(lmp, nlmp, nsym, symndx, symval, 283 &sb_flags); 284 } 285 286 if (!(rtld_flags & RT_FL_NOBIND)) { 287 addr = rptr->r_offset; 288 if (!(FLAGS(lmp) & FLG_RT_FIXED)) 289 addr += ADDR(lmp); 290 if (((lml->lm_tflags | FLAGS1(lmp)) & 291 (LML_TFLG_AUD_PLTENTER | LML_TFLG_AUD_PLTEXIT)) && 292 AUDINFO(lmp)->ai_dynplts) { 293 int fail = 0; 294 uint_t pltndx = reloff / sizeof (Rel); 295 uint_t symndx = (((uintptr_t)nsym - 296 (uintptr_t)SYMTAB(nlmp)) / SYMENT(nlmp)); 297 298 symval = (ulong_t)elf_plt_trace_write(addr, lmp, nlmp, 299 nsym, symndx, pltndx, (caddr_t)symval, sb_flags, 300 &fail); 301 if (fail) 302 rtldexit(lml, 1); 303 } else { 304 /* 305 * Write standard PLT entry to jump directly 306 * to newly bound function. 307 */ 308 *(ulong_t *)addr = symval; 309 } 310 } 311 312 /* 313 * Print binding information and rebuild PLT entry. 314 */ 315 DBG_CALL(Dbg_bind_global(lmp, (Addr)from, (Off)(from - ADDR(lmp)), 316 (Xword)(reloff / sizeof (Rel)), PLT_T_FULL, nlmp, (Addr)symval, 317 nsym->st_value, name, binfo)); 318 319 /* 320 * Complete any processing for newly loaded objects. Note we don't 321 * know exactly where any new objects are loaded (we know the object 322 * that supplied the symbol, but others may have been loaded lazily as 323 * we searched for the symbol), so sorting starts from the last 324 * link-map know on entry to this routine. 325 */ 326 if (entry) 327 load_completion(llmp); 328 329 /* 330 * Some operations like dldump() or dlopen()'ing a relocatable object 331 * result in objects being loaded on rtld's link-map, make sure these 332 * objects are initialized also. 333 */ 334 if ((LIST(nlmp)->lm_flags & LML_FLG_RTLDLM) && LIST(nlmp)->lm_init) 335 load_completion(nlmp); 336 337 /* 338 * If the object we've bound to is in the process of being initialized 339 * by another thread, determine whether we should block. 340 */ 341 is_dep_ready(nlmp, lmp, DBG_WAIT_SYMBOL); 342 343 /* 344 * Make sure the object to which we've bound has had it's .init fired. 345 * Cleanup before return to user code. 346 */ 347 if (entry) { 348 is_dep_init(nlmp, lmp); 349 leave(lml); 350 } 351 352 if (lmflags & LML_FLG_RTLDLM) 353 dbg_desc->d_class = dbg_class; 354 355 return (symval); 356 } 357 358 359 /* 360 * When the relocation loop realizes that it's dealing with relative 361 * relocations in a shared object, it breaks into this tighter loop 362 * as an optimization. 363 */ 364 ulong_t 365 elf_reloc_relative(ulong_t relbgn, ulong_t relend, ulong_t relsiz, 366 ulong_t basebgn, ulong_t etext, ulong_t emap) 367 { 368 ulong_t roffset = ((Rel *)relbgn)->r_offset; 369 char rtype; 370 371 do { 372 roffset += basebgn; 373 374 /* 375 * If this relocation is against an address not mapped in, 376 * then break out of the relative relocation loop, falling 377 * back on the main relocation loop. 378 */ 379 if (roffset < etext || roffset > emap) 380 break; 381 382 /* 383 * Perform the actual relocation. 384 */ 385 *((ulong_t *)roffset) += basebgn; 386 387 relbgn += relsiz; 388 389 if (relbgn >= relend) 390 break; 391 392 rtype = ELF_R_TYPE(((Rel *)relbgn)->r_info); 393 roffset = ((Rel *)relbgn)->r_offset; 394 395 } while (rtype == R_386_RELATIVE); 396 397 return (relbgn); 398 } 399 400 /* 401 * This is the tightest loop for RELATIVE relocations for those 402 * objects built with the DT_RELACOUNT .dynamic entry. 403 */ 404 ulong_t 405 elf_reloc_relacount(ulong_t relbgn, ulong_t relacount, ulong_t relsiz, 406 ulong_t basebgn) 407 { 408 ulong_t roffset = ((Rel *) relbgn)->r_offset; 409 410 for (; relacount; relacount--) { 411 roffset += basebgn; 412 413 /* 414 * Perform the actual relocation. 415 */ 416 *((ulong_t *)roffset) += basebgn; 417 418 relbgn += relsiz; 419 420 roffset = ((Rel *)relbgn)->r_offset; 421 422 } 423 424 return (relbgn); 425 } 426 427 /* 428 * Read and process the relocations for one link object, we assume all 429 * relocation sections for loadable segments are stored contiguously in 430 * the file. 431 */ 432 int 433 elf_reloc(Rt_map *lmp, uint_t plt) 434 { 435 ulong_t relbgn, relend, relsiz, basebgn; 436 ulong_t pltbgn, pltend, _pltbgn, _pltend; 437 ulong_t roffset, rsymndx, psymndx = 0, etext = ETEXT(lmp); 438 ulong_t emap, dsymndx; 439 uchar_t rtype; 440 long value, pvalue; 441 Sym *symref, *psymref, *symdef, *psymdef; 442 char *name, *pname; 443 Rt_map *_lmp, *plmp; 444 int textrel = 0, ret = 1, noplt = 0; 445 int relacount = RELACOUNT(lmp), plthint = 0; 446 Rel *rel; 447 uint_t binfo, pbinfo; 448 Alist *bound = 0; 449 450 /* 451 * Although only necessary for lazy binding, initialize the first 452 * global offset entry to go to elf_rtbndr(). dbx(1) seems 453 * to find this useful. 454 */ 455 if ((plt == 0) && PLTGOT(lmp)) { 456 if ((ulong_t)PLTGOT(lmp) < etext) { 457 if (elf_set_prot(lmp, PROT_WRITE) == 0) 458 return (0); 459 textrel = 1; 460 } 461 elf_plt_init(PLTGOT(lmp), (caddr_t)lmp); 462 } 463 464 /* 465 * Initialize the plt start and end addresses. 466 */ 467 if ((pltbgn = (ulong_t)JMPREL(lmp)) != 0) 468 pltend = pltbgn + (ulong_t)(PLTRELSZ(lmp)); 469 470 471 relsiz = (ulong_t)(RELENT(lmp)); 472 basebgn = ADDR(lmp); 473 emap = ADDR(lmp) + MSIZE(lmp); 474 475 if (PLTRELSZ(lmp)) 476 plthint = PLTRELSZ(lmp) / relsiz; 477 478 /* 479 * If we've been called upon to promote an RTLD_LAZY object to an 480 * RTLD_NOW then we're only interested in scaning the .plt table. 481 * An uninitialized .plt is the case where the associated got entry 482 * points back to the plt itself. Determine the range of the real .plt 483 * entries using the _PROCEDURE_LINKAGE_TABLE_ symbol. 484 */ 485 if (plt) { 486 Slookup sl; 487 488 relbgn = pltbgn; 489 relend = pltend; 490 if (!relbgn || (relbgn == relend)) 491 return (1); 492 493 sl.sl_name = MSG_ORIG(MSG_SYM_PLT); 494 sl.sl_cmap = lmp; 495 sl.sl_imap = lmp; 496 sl.sl_hash = elf_hash(MSG_ORIG(MSG_SYM_PLT)); 497 sl.sl_rsymndx = 0; 498 sl.sl_rsym = 0; 499 sl.sl_flags = LKUP_DEFT; 500 501 if ((symdef = elf_find_sym(&sl, &_lmp, &binfo)) == 0) 502 return (1); 503 504 _pltbgn = symdef->st_value; 505 if (!(FLAGS(lmp) & FLG_RT_FIXED) && 506 (symdef->st_shndx != SHN_ABS)) 507 _pltbgn += basebgn; 508 _pltend = _pltbgn + (((PLTRELSZ(lmp) / relsiz)) * 509 M_PLT_ENTSIZE) + M_PLT_RESERVSZ; 510 511 } else { 512 /* 513 * The relocation sections appear to the run-time linker as a 514 * single table. Determine the address of the beginning and end 515 * of this table. There are two different interpretations of 516 * the ABI at this point: 517 * 518 * o The REL table and its associated RELSZ indicate the 519 * concatenation of *all* relocation sections (this is the 520 * model our link-editor constructs). 521 * 522 * o The REL table and its associated RELSZ indicate the 523 * concatenation of all *but* the .plt relocations. These 524 * relocations are specified individually by the JMPREL and 525 * PLTRELSZ entries. 526 * 527 * Determine from our knowledege of the relocation range and 528 * .plt range, the range of the total relocation table. Note 529 * that one other ABI assumption seems to be that the .plt 530 * relocations always follow any other relocations, the 531 * following range checking drops that assumption. 532 */ 533 relbgn = (ulong_t)(REL(lmp)); 534 relend = relbgn + (ulong_t)(RELSZ(lmp)); 535 if (pltbgn) { 536 if (!relbgn || (relbgn > pltbgn)) 537 relbgn = pltbgn; 538 if (!relbgn || (relend < pltend)) 539 relend = pltend; 540 } 541 } 542 if (!relbgn || (relbgn == relend)) { 543 DBG_CALL(Dbg_reloc_run(lmp, 0, plt, DBG_REL_NONE)); 544 return (1); 545 } 546 DBG_CALL(Dbg_reloc_run(lmp, M_REL_SHT_TYPE, plt, DBG_REL_START)); 547 548 /* 549 * If we're processing a dynamic executable in lazy mode there is no 550 * need to scan the .rel.plt table, however if we're processing a shared 551 * object in lazy mode the .got addresses associated to each .plt must 552 * be relocated to reflect the location of the shared object. 553 */ 554 if (pltbgn && ((MODE(lmp) & RTLD_NOW) == 0) && 555 (FLAGS(lmp) & FLG_RT_FIXED)) 556 noplt = 1; 557 558 /* 559 * Loop through relocations. 560 */ 561 while (relbgn < relend) { 562 uint_t sb_flags = 0; 563 564 rtype = ELF_R_TYPE(((Rel *)relbgn)->r_info); 565 566 /* 567 * If this is a RELATIVE relocation in a shared object (the 568 * common case), and if we are not debugging, then jump into a 569 * tighter relocation loop (elf_reloc_relative). Only make the 570 * jump if we've been given a hint on the number of relocations. 571 */ 572 if ((rtype == R_386_RELATIVE) && 573 ((FLAGS(lmp) & FLG_RT_FIXED) == 0) && (DBG_ENABLED == 0)) { 574 /* 575 * It's possible that the relative relocation block 576 * has relocations against the text segment as well 577 * as the data segment. Since our optimized relocation 578 * engine does not check which segment the relocation 579 * is against - just mprotect it now if it's been 580 * marked as containing TEXTREL's. 581 */ 582 if ((textrel == 0) && (FLAGS1(lmp) & FL1_RT_TEXTREL)) { 583 if (elf_set_prot(lmp, PROT_WRITE) == 0) { 584 ret = 0; 585 break; 586 } 587 textrel = 1; 588 } 589 590 if (relacount) { 591 relbgn = elf_reloc_relacount(relbgn, relacount, 592 relsiz, basebgn); 593 relacount = 0; 594 } else { 595 relbgn = elf_reloc_relative(relbgn, relend, 596 relsiz, basebgn, etext, emap); 597 } 598 if (relbgn >= relend) 599 break; 600 rtype = ELF_R_TYPE(((Rel *)relbgn)->r_info); 601 } 602 603 roffset = ((Rel *)relbgn)->r_offset; 604 605 /* 606 * If this is a shared object, add the base address to offset. 607 */ 608 if (!(FLAGS(lmp) & FLG_RT_FIXED)) { 609 610 /* 611 * If we're processing lazy bindings, we have to step 612 * through the plt entries and add the base address 613 * to the corresponding got entry. 614 */ 615 if (plthint && (plt == 0) && 616 (rtype == R_386_JMP_SLOT) && 617 ((MODE(lmp) & RTLD_NOW) == 0)) { 618 relbgn = elf_reloc_relacount(relbgn, 619 plthint, relsiz, basebgn); 620 plthint = 0; 621 continue; 622 } 623 roffset += basebgn; 624 } 625 626 rsymndx = ELF_R_SYM(((Rel *)relbgn)->r_info); 627 rel = (Rel *)relbgn; 628 relbgn += relsiz; 629 630 /* 631 * Optimizations. 632 */ 633 if (rtype == R_386_NONE) 634 continue; 635 if (noplt && ((ulong_t)rel >= pltbgn) && 636 ((ulong_t)rel < pltend)) { 637 relbgn = pltend; 638 continue; 639 } 640 641 /* 642 * If we're promoting plts determine if this one has already 643 * been written. 644 */ 645 if (plt) { 646 if ((*(ulong_t *)roffset < _pltbgn) || 647 (*(ulong_t *)roffset > _pltend)) 648 continue; 649 } 650 651 /* 652 * If this relocation is not against part of the image 653 * mapped into memory we skip it. 654 */ 655 if ((roffset < ADDR(lmp)) || (roffset > (ADDR(lmp) + 656 MSIZE(lmp)))) { 657 elf_reloc_bad(lmp, (void *)rel, rtype, roffset, 658 rsymndx); 659 continue; 660 } 661 662 binfo = 0; 663 /* 664 * If a symbol index is specified then get the symbol table 665 * entry, locate the symbol definition, and determine its 666 * address. 667 */ 668 if (rsymndx) { 669 /* 670 * Get the local symbol table entry. 671 */ 672 symref = (Sym *)((ulong_t)SYMTAB(lmp) + 673 (rsymndx * SYMENT(lmp))); 674 675 /* 676 * If this is a local symbol, just use the base address. 677 * (we should have no local relocations in the 678 * executable). 679 */ 680 if (ELF_ST_BIND(symref->st_info) == STB_LOCAL) { 681 value = basebgn; 682 name = (char *)0; 683 684 /* 685 * Special case TLS relocations. 686 */ 687 if (rtype == R_386_TLS_DTPMOD32) { 688 /* 689 * Use the TLS modid. 690 */ 691 value = TLSMODID(lmp); 692 693 } else if (rtype == R_386_TLS_TPOFF) { 694 if ((value = elf_static_tls(lmp, symref, 695 rel, rtype, 0, roffset, 0)) == 0) { 696 ret = 0; 697 break; 698 } 699 } 700 } else { 701 /* 702 * If the symbol index is equal to the previous 703 * symbol index relocation we processed then 704 * reuse the previous values. (Note that there 705 * have been cases where a relocation exists 706 * against a copy relocation symbol, our ld(1) 707 * should optimize this away, but make sure we 708 * don't use the same symbol information should 709 * this case exist). 710 */ 711 if ((rsymndx == psymndx) && 712 (rtype != R_386_COPY)) { 713 /* LINTED */ 714 if (psymdef == 0) { 715 DBG_CALL(Dbg_bind_weak(lmp, 716 (Addr)roffset, (Addr) 717 (roffset - basebgn), name)); 718 continue; 719 } 720 /* LINTED */ 721 value = pvalue; 722 /* LINTED */ 723 name = pname; 724 /* LINTED */ 725 symdef = psymdef; 726 /* LINTED */ 727 symref = psymref; 728 /* LINTED */ 729 _lmp = plmp; 730 /* LINTED */ 731 binfo = pbinfo; 732 733 if ((LIST(_lmp)->lm_tflags | 734 FLAGS1(_lmp)) & 735 LML_TFLG_AUD_SYMBIND) { 736 value = audit_symbind(lmp, _lmp, 737 /* LINTED */ 738 symdef, dsymndx, value, 739 &sb_flags); 740 } 741 } else { 742 Slookup sl; 743 744 /* 745 * Lookup the symbol definition. 746 */ 747 name = (char *)(STRTAB(lmp) + 748 symref->st_name); 749 750 sl.sl_name = name; 751 sl.sl_cmap = lmp; 752 sl.sl_imap = 0; 753 sl.sl_hash = 0; 754 sl.sl_rsymndx = rsymndx; 755 sl.sl_rsym = symref; 756 sl.sl_rtype = rtype; 757 sl.sl_flags = LKUP_STDRELOC; 758 759 symdef = lookup_sym(&sl, &_lmp, &binfo); 760 761 /* 762 * If the symbol is not found and the 763 * reference was not to a weak symbol, 764 * report an error. Weak references 765 * may be unresolved. 766 * chkmsg: MSG_INTL(MSG_LDD_SYM_NFOUND) 767 */ 768 /* BEGIN CSTYLED */ 769 if (symdef == 0) { 770 Lm_list *lml = LIST(lmp); 771 772 if (sl.sl_bind != STB_WEAK) { 773 if (lml->lm_flags & 774 LML_FLG_IGNRELERR) { 775 continue; 776 } else if (lml->lm_flags & 777 LML_FLG_TRC_WARN) { 778 (void) printf(MSG_INTL( 779 MSG_LDD_SYM_NFOUND), 780 demangle(name), 781 NAME(lmp)); 782 continue; 783 } else { 784 DBG_CALL(Dbg_reloc_in(lml, 785 ELF_DBG_RTLD, M_MACH, 786 M_REL_SHT_TYPE, rel, 787 NULL, name)); 788 eprintf(lml, ERR_FATAL, 789 MSG_INTL(MSG_REL_NOSYM), 790 NAME(lmp), 791 demangle(name)); 792 ret = 0; 793 break; 794 } 795 } else { 796 psymndx = rsymndx; 797 psymdef = 0; 798 799 DBG_CALL(Dbg_bind_weak(lmp, 800 (Addr)roffset, (Addr) 801 (roffset - basebgn), name)); 802 continue; 803 } 804 } 805 /* END CSTYLED */ 806 807 /* 808 * If symbol was found in an object 809 * other than the referencing object 810 * then record the binding. 811 */ 812 if ((lmp != _lmp) && ((FLAGS1(_lmp) & 813 FL1_RT_NOINIFIN) == 0)) { 814 if (alist_test(&bound, _lmp, 815 sizeof (Rt_map *), 816 AL_CNT_RELBIND) == 0) { 817 ret = 0; 818 break; 819 } 820 } 821 822 /* 823 * Calculate the location of definition; 824 * symbol value plus base address of 825 * containing shared object. 826 */ 827 if (IS_SIZE(rtype)) 828 value = symdef->st_size; 829 else 830 value = symdef->st_value; 831 832 if (!(FLAGS(_lmp) & FLG_RT_FIXED) && 833 !(IS_SIZE(rtype)) && 834 (symdef->st_shndx != SHN_ABS) && 835 (ELF_ST_TYPE(symdef->st_info) != 836 STT_TLS)) 837 value += ADDR(_lmp); 838 839 /* 840 * Retain this symbol index and the 841 * value in case it can be used for the 842 * subsequent relocations. 843 */ 844 if (rtype != R_386_COPY) { 845 psymndx = rsymndx; 846 pvalue = value; 847 pname = name; 848 psymdef = symdef; 849 psymref = symref; 850 plmp = _lmp; 851 pbinfo = binfo; 852 } 853 if ((LIST(_lmp)->lm_tflags | 854 FLAGS1(_lmp)) & 855 LML_TFLG_AUD_SYMBIND) { 856 dsymndx = (((uintptr_t)symdef - 857 (uintptr_t)SYMTAB(_lmp)) / 858 SYMENT(_lmp)); 859 value = audit_symbind(lmp, _lmp, 860 symdef, dsymndx, value, 861 &sb_flags); 862 } 863 } 864 865 /* 866 * If relocation is PC-relative, subtract 867 * offset address. 868 */ 869 if (IS_PC_RELATIVE(rtype)) 870 value -= roffset; 871 872 /* 873 * Special case TLS relocations. 874 */ 875 if (rtype == R_386_TLS_DTPMOD32) { 876 /* 877 * Relocation value is the TLS modid. 878 */ 879 value = TLSMODID(_lmp); 880 881 } else if (rtype == R_386_TLS_TPOFF) { 882 if ((value = elf_static_tls(_lmp, 883 symdef, rel, rtype, name, roffset, 884 value)) == 0) { 885 ret = 0; 886 break; 887 } 888 } 889 } 890 } else { 891 /* 892 * Special cases. 893 */ 894 if (rtype == R_386_TLS_DTPMOD32) { 895 /* 896 * TLS relocation value is the TLS modid. 897 */ 898 value = TLSMODID(lmp); 899 } else 900 value = basebgn; 901 name = (char *)0; 902 } 903 904 DBG_CALL(Dbg_reloc_in(LIST(lmp), ELF_DBG_RTLD, M_MACH, 905 M_REL_SHT_TYPE, rel, NULL, name)); 906 907 /* 908 * If this object has relocations in the text segment, turn 909 * off the write protect. 910 */ 911 if ((roffset < etext) && (textrel == 0)) { 912 if (elf_set_prot(lmp, PROT_WRITE) == 0) { 913 ret = 0; 914 break; 915 } 916 textrel = 1; 917 } 918 919 /* 920 * Call relocation routine to perform required relocation. 921 */ 922 switch (rtype) { 923 case R_386_COPY: 924 if (elf_copy_reloc(name, symref, lmp, (void *)roffset, 925 symdef, _lmp, (const void *)value) == 0) 926 ret = 0; 927 break; 928 case R_386_JMP_SLOT: 929 if (((LIST(lmp)->lm_tflags | FLAGS1(lmp)) & 930 (LML_TFLG_AUD_PLTENTER | LML_TFLG_AUD_PLTEXIT)) && 931 AUDINFO(lmp)->ai_dynplts) { 932 int fail = 0; 933 int pltndx = (((ulong_t)rel - 934 (uintptr_t)JMPREL(lmp)) / relsiz); 935 int symndx = (((uintptr_t)symdef - 936 (uintptr_t)SYMTAB(_lmp)) / SYMENT(_lmp)); 937 938 (void) elf_plt_trace_write(roffset, lmp, _lmp, 939 symdef, symndx, pltndx, (caddr_t)value, 940 sb_flags, &fail); 941 if (fail) 942 ret = 0; 943 } else { 944 /* 945 * Write standard PLT entry to jump directly 946 * to newly bound function. 947 */ 948 DBG_CALL(Dbg_reloc_apply_val(LIST(lmp), 949 ELF_DBG_RTLD, (Xword)roffset, 950 (Xword)value)); 951 *(ulong_t *)roffset = value; 952 } 953 break; 954 default: 955 /* 956 * Write the relocation out. 957 */ 958 if (do_reloc_rtld(rtype, (uchar_t *)roffset, 959 (Word *)&value, name, NAME(lmp), LIST(lmp)) == 0) 960 ret = 0; 961 962 DBG_CALL(Dbg_reloc_apply_val(LIST(lmp), ELF_DBG_RTLD, 963 (Xword)roffset, (Xword)value)); 964 } 965 966 if ((ret == 0) && 967 ((LIST(lmp)->lm_flags & LML_FLG_TRC_WARN) == 0)) 968 break; 969 970 if (binfo) { 971 DBG_CALL(Dbg_bind_global(lmp, (Addr)roffset, 972 (Off)(roffset - basebgn), (Xword)(-1), PLT_T_FULL, 973 _lmp, (Addr)value, symdef->st_value, name, binfo)); 974 } 975 } 976 977 return (relocate_finish(lmp, bound, textrel, ret)); 978 } 979 980 /* 981 * Initialize the first few got entries so that function calls go to 982 * elf_rtbndr: 983 * 984 * GOT[GOT_XLINKMAP] = the address of the link map 985 * GOT[GOT_XRTLD] = the address of rtbinder 986 */ 987 void 988 elf_plt_init(void *got, caddr_t l) 989 { 990 uint_t *_got; 991 /* LINTED */ 992 Rt_map *lmp = (Rt_map *)l; 993 994 _got = (uint_t *)got + M_GOT_XLINKMAP; 995 *_got = (uint_t)lmp; 996 _got = (uint_t *)got + M_GOT_XRTLD; 997 *_got = (uint_t)elf_rtbndr; 998 } 999 1000 /* 1001 * For SVR4 Intel compatability. USL uses /usr/lib/libc.so.1 as the run-time 1002 * linker, so the interpreter's address will differ from /usr/lib/ld.so.1. 1003 * Further, USL has special _iob[] and _ctype[] processing that makes up for the 1004 * fact that these arrays do not have associated copy relocations. So we try 1005 * and make up for that here. Any relocations found will be added to the global 1006 * copy relocation list and will be processed in setup(). 1007 */ 1008 static int 1009 _elf_copy_reloc(const char *name, Rt_map *rlmp, Rt_map *dlmp) 1010 { 1011 Sym *symref, *symdef; 1012 caddr_t ref, def; 1013 Rt_map *_lmp; 1014 Rel rel; 1015 Slookup sl; 1016 uint_t binfo; 1017 1018 /* 1019 * Determine if the special symbol exists as a reference in the dynamic 1020 * executable, and that an associated definition exists in libc.so.1. 1021 */ 1022 sl.sl_name = name; 1023 sl.sl_cmap = rlmp; 1024 sl.sl_imap = rlmp; 1025 sl.sl_hash = 0; 1026 sl.sl_rsymndx = 0; 1027 sl.sl_rsym = 0; 1028 sl.sl_flags = LKUP_FIRST; 1029 1030 if ((symref = lookup_sym(&sl, &_lmp, &binfo)) == 0) 1031 return (1); 1032 1033 sl.sl_imap = dlmp; 1034 sl.sl_flags = LKUP_DEFT; 1035 1036 if ((symdef = lookup_sym(&sl, &_lmp, &binfo)) == 0) 1037 return (1); 1038 if (strcmp(NAME(_lmp), MSG_ORIG(MSG_PTH_LIBC))) 1039 return (1); 1040 1041 /* 1042 * Determine the reference and definition addresses. 1043 */ 1044 ref = (void *)(symref->st_value); 1045 if (!(FLAGS(rlmp) & FLG_RT_FIXED)) 1046 ref += ADDR(rlmp); 1047 def = (void *)(symdef->st_value); 1048 if (!(FLAGS(_lmp) & FLG_RT_FIXED)) 1049 def += ADDR(_lmp); 1050 1051 /* 1052 * Set up a relocation entry for debugging and call the generic copy 1053 * relocation function to provide symbol size error checking and to 1054 * record the copy relocation that must be performed. 1055 */ 1056 rel.r_offset = (Addr)ref; 1057 rel.r_info = (Word)R_386_COPY; 1058 DBG_CALL(Dbg_reloc_in(LIST(rlmp), ELF_DBG_RTLD, M_MACH, M_REL_SHT_TYPE, 1059 &rel, NULL, name)); 1060 1061 return (elf_copy_reloc((char *)name, symref, rlmp, (void *)ref, symdef, 1062 _lmp, (void *)def)); 1063 } 1064 1065 int 1066 elf_copy_gen(Rt_map *lmp) 1067 { 1068 if (interp && ((ulong_t)interp->i_faddr != 1069 r_debug.rtd_rdebug.r_ldbase) && 1070 !(strcmp(interp->i_name, MSG_ORIG(MSG_PTH_LIBC)))) { 1071 1072 DBG_CALL(Dbg_reloc_run(lmp, M_REL_SHT_TYPE, 0, 1073 DBG_REL_START)); 1074 1075 if (_elf_copy_reloc(MSG_ORIG(MSG_SYM_CTYPE), lmp, 1076 (Rt_map *)NEXT(lmp)) == 0) 1077 return (0); 1078 if (_elf_copy_reloc(MSG_ORIG(MSG_SYM_IOB), lmp, 1079 (Rt_map *)NEXT(lmp)) == 0) 1080 return (0); 1081 } 1082 return (1); 1083 } 1084 1085 /* 1086 * Plt writing interface to allow debugging initialization to be generic. 1087 */ 1088 Pltbindtype 1089 /* ARGSUSED1 */ 1090 elf_plt_write(uintptr_t addr, uintptr_t vaddr, void *rptr, uintptr_t symval, 1091 Xword pltndx) 1092 { 1093 Rel *rel = (Rel*)rptr; 1094 uintptr_t pltaddr; 1095 1096 pltaddr = addr + rel->r_offset; 1097 *(ulong_t *)pltaddr = (ulong_t)symval; 1098 DBG_CALL(pltcntfull++); 1099 return (PLT_T_FULL); 1100 } 1101 1102 /* 1103 * Provide a machine specific interface to the conversion routine. By calling 1104 * the machine specific version, rather than the generic version, we insure that 1105 * the data tables/strings for all known machine versions aren't dragged into 1106 * ld.so.1. 1107 */ 1108 const char * 1109 _conv_reloc_type(uint_t rel) 1110 { 1111 static Conv_inv_buf_t inv_buf; 1112 1113 return (conv_reloc_386_type(rel, 0, &inv_buf)); 1114 } 1115