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 2006 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(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(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 *sym, *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 eprintf(lml, ERR_FATAL, MSG_INTL(MSG_REL_PLTREF), 228 conv_reloc_386_type(R_386_JMP_SLOT, 0), 229 EC_NATPTR(lmp), EC_XWORD(reloff), EC_NATPTR(from)); 230 rtldexit(lml, 1); 231 } 232 233 /* 234 * Use relocation entry to get symbol table entry and symbol name. 235 */ 236 addr = (ulong_t)JMPREL(lmp); 237 rptr = (Rel *)(addr + reloff); 238 rsymndx = ELF_R_SYM(rptr->r_info); 239 sym = (Sym *)((ulong_t)SYMTAB(lmp) + (rsymndx * SYMENT(lmp))); 240 name = (char *)(STRTAB(lmp) + sym->st_name); 241 242 /* 243 * Determine the last link-map of this list, this'll be the starting 244 * point for any tsort() processing. 245 */ 246 llmp = lml->lm_tail; 247 248 /* 249 * Find definition for symbol. 250 */ 251 sl.sl_name = name; 252 sl.sl_cmap = lmp; 253 sl.sl_imap = lml->lm_head; 254 sl.sl_hash = 0; 255 sl.sl_rsymndx = rsymndx; 256 sl.sl_flags = LKUP_DEFT; 257 258 if ((nsym = lookup_sym(&sl, &nlmp, &binfo)) == 0) { 259 eprintf(lml, ERR_FATAL, MSG_INTL(MSG_REL_NOSYM), NAME(lmp), 260 demangle(name)); 261 rtldexit(lml, 1); 262 } 263 264 symval = nsym->st_value; 265 if (!(FLAGS(nlmp) & FLG_RT_FIXED) && 266 (nsym->st_shndx != SHN_ABS)) 267 symval += ADDR(nlmp); 268 if ((lmp != nlmp) && ((FLAGS1(nlmp) & FL1_RT_NOINIFIN) == 0)) { 269 /* 270 * Record that this new link map is now bound to the caller. 271 */ 272 if (bind_one(lmp, nlmp, BND_REFER) == 0) 273 rtldexit(lml, 1); 274 } 275 276 if ((lml->lm_tflags | FLAGS1(lmp)) & LML_TFLG_AUD_SYMBIND) { 277 uint_t symndx = (((uintptr_t)nsym - 278 (uintptr_t)SYMTAB(nlmp)) / SYMENT(nlmp)); 279 symval = audit_symbind(lmp, nlmp, nsym, symndx, symval, 280 &sb_flags); 281 } 282 283 if (!(rtld_flags & RT_FL_NOBIND)) { 284 addr = rptr->r_offset; 285 if (!(FLAGS(lmp) & FLG_RT_FIXED)) 286 addr += ADDR(lmp); 287 if (((lml->lm_tflags | FLAGS1(lmp)) & 288 (LML_TFLG_AUD_PLTENTER | LML_TFLG_AUD_PLTEXIT)) && 289 AUDINFO(lmp)->ai_dynplts) { 290 int fail = 0; 291 uint_t pltndx = reloff / sizeof (Rel); 292 uint_t symndx = (((uintptr_t)nsym - 293 (uintptr_t)SYMTAB(nlmp)) / 294 SYMENT(nlmp)); 295 296 symval = (ulong_t)elf_plt_trace_write(addr, lmp, nlmp, 297 nsym, symndx, pltndx, (caddr_t)symval, sb_flags, 298 &fail); 299 if (fail) 300 rtldexit(lml, 1); 301 } else { 302 /* 303 * Write standard PLT entry to jump directly 304 * to newly bound function. 305 */ 306 *(ulong_t *)addr = symval; 307 } 308 } 309 310 /* 311 * Print binding information and rebuild PLT entry. 312 */ 313 DBG_CALL(Dbg_bind_global(lmp, (Addr)from, (Off)(from - ADDR(lmp)), 314 (Xword)(reloff / sizeof (Rel)), PLT_T_FULL, nlmp, (Addr)symval, 315 nsym->st_value, name, binfo)); 316 317 /* 318 * Complete any processing for newly loaded objects. Note we don't 319 * know exactly where any new objects are loaded (we know the object 320 * that supplied the symbol, but others may have been loaded lazily as 321 * we searched for the symbol), so sorting starts from the last 322 * link-map know on entry to this routine. 323 */ 324 if (entry) 325 load_completion(llmp, lmp); 326 327 /* 328 * Some operations like dldump() or dlopen()'ing a relocatable object 329 * result in objects being loaded on rtld's link-map, make sure these 330 * objects are initialized also. 331 */ 332 if ((LIST(nlmp)->lm_flags & LML_FLG_RTLDLM) && LIST(nlmp)->lm_init) 333 load_completion(nlmp, 0); 334 335 /* 336 * If the object we've bound to is in the process of being initialized 337 * by another thread, determine whether we should block. 338 */ 339 is_dep_ready(nlmp, lmp, DBG_WAIT_SYMBOL); 340 341 /* 342 * Make sure the object to which we've bound has had it's .init fired. 343 * Cleanup before return to user code. 344 */ 345 if (entry) { 346 is_dep_init(nlmp, lmp); 347 leave(lml); 348 } 349 350 if (lmflags & LML_FLG_RTLDLM) 351 dbg_desc->d_class = dbg_class; 352 353 return (symval); 354 } 355 356 357 /* 358 * When the relocation loop realizes that it's dealing with relative 359 * relocations in a shared object, it breaks into this tighter loop 360 * as an optimization. 361 */ 362 ulong_t 363 elf_reloc_relative(ulong_t relbgn, ulong_t relend, ulong_t relsiz, 364 ulong_t basebgn, ulong_t etext, ulong_t emap) 365 { 366 ulong_t roffset = ((Rel *)relbgn)->r_offset; 367 char rtype; 368 369 do { 370 roffset += basebgn; 371 372 /* 373 * If this relocation is against an address not mapped in, 374 * then break out of the relative relocation loop, falling 375 * back on the main relocation loop. 376 */ 377 if (roffset < etext || roffset > emap) 378 break; 379 380 /* 381 * Perform the actual relocation. 382 */ 383 *((ulong_t *)roffset) += basebgn; 384 385 relbgn += relsiz; 386 387 if (relbgn >= relend) 388 break; 389 390 rtype = ELF_R_TYPE(((Rel *)relbgn)->r_info); 391 roffset = ((Rel *)relbgn)->r_offset; 392 393 } while (rtype == R_386_RELATIVE); 394 395 return (relbgn); 396 } 397 398 /* 399 * This is the tightest loop for RELATIVE relocations for those 400 * objects built with the DT_RELACOUNT .dynamic entry. 401 */ 402 ulong_t 403 elf_reloc_relacount(ulong_t relbgn, ulong_t relacount, ulong_t relsiz, 404 ulong_t basebgn) 405 { 406 ulong_t roffset = ((Rel *) relbgn)->r_offset; 407 408 for (; relacount; relacount--) { 409 roffset += basebgn; 410 411 /* 412 * Perform the actual relocation. 413 */ 414 *((ulong_t *)roffset) += basebgn; 415 416 relbgn += relsiz; 417 418 roffset = ((Rel *)relbgn)->r_offset; 419 420 } 421 422 return (relbgn); 423 } 424 425 /* 426 * Read and process the relocations for one link object, we assume all 427 * relocation sections for loadable segments are stored contiguously in 428 * the file. 429 */ 430 int 431 elf_reloc(Rt_map *lmp, uint_t plt) 432 { 433 ulong_t relbgn, relend, relsiz, basebgn; 434 ulong_t pltbgn, pltend, _pltbgn, _pltend; 435 ulong_t roffset, rsymndx, psymndx = 0, etext = ETEXT(lmp); 436 ulong_t emap, dsymndx; 437 uchar_t rtype; 438 long value, pvalue; 439 Sym *symref, *psymref, *symdef, *psymdef; 440 char *name, *pname; 441 Rt_map *_lmp, *plmp; 442 int textrel = 0, ret = 1, noplt = 0; 443 int relacount = RELACOUNT(lmp), plthint = 0; 444 Rel *rel; 445 uint_t binfo, pbinfo; 446 Alist *bound = 0; 447 448 /* 449 * Although only necessary for lazy binding, initialize the first 450 * global offset entry to go to elf_rtbndr(). dbx(1) seems 451 * to find this useful. 452 */ 453 if ((plt == 0) && PLTGOT(lmp)) { 454 if ((ulong_t)PLTGOT(lmp) < etext) { 455 if (elf_set_prot(lmp, PROT_WRITE) == 0) 456 return (0); 457 textrel = 1; 458 } 459 elf_plt_init(PLTGOT(lmp), (caddr_t)lmp); 460 } 461 462 /* 463 * Initialize the plt start and end addresses. 464 */ 465 if ((pltbgn = (ulong_t)JMPREL(lmp)) != 0) 466 pltend = pltbgn + (ulong_t)(PLTRELSZ(lmp)); 467 468 469 relsiz = (ulong_t)(RELENT(lmp)); 470 basebgn = ADDR(lmp); 471 emap = ADDR(lmp) + MSIZE(lmp); 472 473 if (PLTRELSZ(lmp)) 474 plthint = PLTRELSZ(lmp) / relsiz; 475 476 /* 477 * If we've been called upon to promote an RTLD_LAZY object to an 478 * RTLD_NOW then we're only interested in scaning the .plt table. 479 * An uninitialized .plt is the case where the associated got entry 480 * points back to the plt itself. Determine the range of the real .plt 481 * entries using the _PROCEDURE_LINKAGE_TABLE_ symbol. 482 */ 483 if (plt) { 484 Slookup sl; 485 486 relbgn = pltbgn; 487 relend = pltend; 488 if (!relbgn || (relbgn == relend)) 489 return (1); 490 491 sl.sl_name = MSG_ORIG(MSG_SYM_PLT); 492 sl.sl_cmap = lmp; 493 sl.sl_imap = lmp; 494 sl.sl_hash = elf_hash(MSG_ORIG(MSG_SYM_PLT)); 495 sl.sl_rsymndx = 0; 496 sl.sl_flags = LKUP_DEFT; 497 498 if ((symdef = elf_find_sym(&sl, &_lmp, &binfo)) == 0) 499 return (1); 500 501 _pltbgn = symdef->st_value; 502 if (!(FLAGS(lmp) & FLG_RT_FIXED) && 503 (symdef->st_shndx != SHN_ABS)) 504 _pltbgn += basebgn; 505 _pltend = _pltbgn + (((PLTRELSZ(lmp) / relsiz)) * 506 M_PLT_ENTSIZE) + M_PLT_RESERVSZ; 507 508 } else { 509 /* 510 * The relocation sections appear to the run-time linker as a 511 * single table. Determine the address of the beginning and end 512 * of this table. There are two different interpretations of 513 * the ABI at this point: 514 * 515 * o The REL table and its associated RELSZ indicate the 516 * concatenation of *all* relocation sections (this is the 517 * model our link-editor constructs). 518 * 519 * o The REL table and its associated RELSZ indicate the 520 * concatenation of all *but* the .plt relocations. These 521 * relocations are specified individually by the JMPREL and 522 * PLTRELSZ entries. 523 * 524 * Determine from our knowledege of the relocation range and 525 * .plt range, the range of the total relocation table. Note 526 * that one other ABI assumption seems to be that the .plt 527 * relocations always follow any other relocations, the 528 * following range checking drops that assumption. 529 */ 530 relbgn = (ulong_t)(REL(lmp)); 531 relend = relbgn + (ulong_t)(RELSZ(lmp)); 532 if (pltbgn) { 533 if (!relbgn || (relbgn > pltbgn)) 534 relbgn = pltbgn; 535 if (!relbgn || (relend < pltend)) 536 relend = pltend; 537 } 538 } 539 if (!relbgn || (relbgn == relend)) { 540 DBG_CALL(Dbg_reloc_run(lmp, 0, plt, DBG_REL_NONE)); 541 return (1); 542 } 543 DBG_CALL(Dbg_reloc_run(lmp, M_REL_SHT_TYPE, plt, DBG_REL_START)); 544 545 /* 546 * If we're processing a dynamic executable in lazy mode there is no 547 * need to scan the .rel.plt table, however if we're processing a shared 548 * object in lazy mode the .got addresses associated to each .plt must 549 * be relocated to reflect the location of the shared object. 550 */ 551 if (pltbgn && ((MODE(lmp) & RTLD_NOW) == 0) && 552 (FLAGS(lmp) & FLG_RT_FIXED)) 553 noplt = 1; 554 555 /* 556 * Loop through relocations. 557 */ 558 while (relbgn < relend) { 559 uint_t sb_flags = 0; 560 561 rtype = ELF_R_TYPE(((Rel *)relbgn)->r_info); 562 563 /* 564 * If this is a RELATIVE relocation in a shared object (the 565 * common case), and if we are not debugging, then jump into a 566 * tighter relocation loop (elf_reloc_relative). Only make the 567 * jump if we've been given a hint on the number of relocations. 568 */ 569 if ((rtype == R_386_RELATIVE) && 570 ((FLAGS(lmp) & FLG_RT_FIXED) == 0) && (DBG_ENABLED == 0)) { 571 /* 572 * It's possible that the relative relocation block 573 * has relocations against the text segment as well 574 * as the data segment. Since our optimized relocation 575 * engine does not check which segment the relocation 576 * is against - just mprotect it now if it's been 577 * marked as containing TEXTREL's. 578 */ 579 if ((textrel == 0) && (FLAGS1(lmp) & FL1_RT_TEXTREL)) { 580 if (elf_set_prot(lmp, PROT_WRITE) == 0) { 581 ret = 0; 582 break; 583 } 584 textrel = 1; 585 } 586 if (relacount) { 587 relbgn = elf_reloc_relacount(relbgn, relacount, 588 relsiz, basebgn); 589 relacount = 0; 590 } else { 591 relbgn = elf_reloc_relative(relbgn, relend, 592 relsiz, basebgn, etext, emap); 593 } 594 if (relbgn >= relend) 595 break; 596 rtype = ELF_R_TYPE(((Rel *)relbgn)->r_info); 597 } 598 599 roffset = ((Rel *)relbgn)->r_offset; 600 601 /* 602 * If this is a shared object, add the base address to offset. 603 */ 604 if (!(FLAGS(lmp) & FLG_RT_FIXED)) { 605 606 /* 607 * If we're processing lazy bindings, we have to step 608 * through the plt entries and add the base address 609 * to the corresponding got entry. 610 */ 611 if (plthint && (plt == 0) && 612 (rtype == R_386_JMP_SLOT) && 613 ((MODE(lmp) & RTLD_NOW) == 0)) { 614 relbgn = elf_reloc_relacount(relbgn, 615 plthint, relsiz, basebgn); 616 plthint = 0; 617 continue; 618 } 619 roffset += basebgn; 620 } 621 622 rsymndx = ELF_R_SYM(((Rel *)relbgn)->r_info); 623 rel = (Rel *)relbgn; 624 relbgn += relsiz; 625 626 /* 627 * Optimizations. 628 */ 629 if (rtype == R_386_NONE) 630 continue; 631 if (noplt && ((ulong_t)rel >= pltbgn) && 632 ((ulong_t)rel < pltend)) { 633 relbgn = pltend; 634 continue; 635 } 636 637 /* 638 * If we're promoting plts determine if this one has already 639 * been written. 640 */ 641 if (plt) { 642 if ((*(ulong_t *)roffset < _pltbgn) || 643 (*(ulong_t *)roffset > _pltend)) 644 continue; 645 } 646 647 /* 648 * If this relocation is not against part of the image 649 * mapped into memory we skip it. 650 */ 651 if ((roffset < ADDR(lmp)) || (roffset > (ADDR(lmp) + 652 MSIZE(lmp)))) { 653 elf_reloc_bad(lmp, (void *)rel, 654 rtype, roffset, rsymndx); 655 continue; 656 } 657 658 binfo = 0; 659 /* 660 * If a symbol index is specified then get the symbol table 661 * entry, locate the symbol definition, and determine its 662 * address. 663 */ 664 if (rsymndx) { 665 /* 666 * Get the local symbol table entry. 667 */ 668 symref = (Sym *)((ulong_t)SYMTAB(lmp) + 669 (rsymndx * SYMENT(lmp))); 670 671 /* 672 * If this is a local symbol, just use the base address. 673 * (we should have no local relocations in the 674 * executable). 675 */ 676 if (ELF_ST_BIND(symref->st_info) == STB_LOCAL) { 677 value = basebgn; 678 name = (char *)0; 679 680 /* 681 * TLS relocation - value for DTPMOD32 682 * relocation is the TLS modid. 683 */ 684 if (rtype == R_386_TLS_DTPMOD32) 685 value = TLSMODID(lmp); 686 } else { 687 /* 688 * If the symbol index is equal to the previous 689 * symbol index relocation we processed then 690 * reuse the previous values. (Note that there 691 * have been cases where a relocation exists 692 * against a copy relocation symbol, our ld(1) 693 * should optimize this away, but make sure we 694 * don't use the same symbol information should 695 * this case exist). 696 */ 697 if ((rsymndx == psymndx) && 698 (rtype != R_386_COPY)) { 699 /* LINTED */ 700 if (psymdef == 0) { 701 DBG_CALL(Dbg_bind_weak(lmp, 702 (Addr)roffset, (Addr) 703 (roffset - basebgn), name)); 704 continue; 705 } 706 /* LINTED */ 707 value = pvalue; 708 /* LINTED */ 709 name = pname; 710 /* LINTED */ 711 symdef = psymdef; 712 /* LINTED */ 713 symref = psymref; 714 /* LINTED */ 715 _lmp = plmp; 716 /* LINTED */ 717 binfo = pbinfo; 718 719 if ((LIST(_lmp)->lm_tflags | 720 FLAGS1(_lmp)) & 721 LML_TFLG_AUD_SYMBIND) { 722 value = audit_symbind(lmp, _lmp, 723 /* LINTED */ 724 symdef, dsymndx, value, 725 &sb_flags); 726 } 727 } else { 728 Slookup sl; 729 uchar_t bind; 730 731 /* 732 * Lookup the symbol definition. 733 */ 734 name = (char *)(STRTAB(lmp) + 735 symref->st_name); 736 737 sl.sl_name = name; 738 sl.sl_cmap = lmp; 739 sl.sl_imap = 0; 740 sl.sl_hash = 0; 741 sl.sl_rsymndx = rsymndx; 742 743 if (rtype == R_386_COPY) 744 sl.sl_flags = LKUP_COPY; 745 else 746 sl.sl_flags = LKUP_DEFT; 747 748 sl.sl_flags |= LKUP_ALLCNTLIST; 749 750 if (rtype != R_386_JMP_SLOT) 751 sl.sl_flags |= LKUP_SPEC; 752 753 bind = ELF_ST_BIND(symref->st_info); 754 if (bind == STB_WEAK) 755 sl.sl_flags |= LKUP_WEAK; 756 757 symdef = lookup_sym(&sl, &_lmp, &binfo); 758 759 /* 760 * If the symbol is not found and the 761 * reference was not to a weak symbol, 762 * report an error. Weak references 763 * may be unresolved. 764 * chkmsg: MSG_INTL(MSG_LDD_SYM_NFOUND) 765 */ 766 if (symdef == 0) { 767 Lm_list *lml = LIST(lmp); 768 769 if (bind != STB_WEAK) { 770 if (lml->lm_flags & 771 LML_FLG_IGNRELERR) { 772 continue; 773 } else if (lml->lm_flags & 774 LML_FLG_TRC_WARN) { 775 (void) printf(MSG_INTL( 776 MSG_LDD_SYM_NFOUND), 777 demangle(name), 778 NAME(lmp)); 779 continue; 780 } else { 781 eprintf(lml, ERR_FATAL, 782 MSG_INTL(MSG_REL_NOSYM), 783 NAME(lmp), 784 demangle(name)); 785 ret = 0; 786 break; 787 } 788 } else { 789 psymndx = rsymndx; 790 psymdef = 0; 791 792 DBG_CALL(Dbg_bind_weak(lmp, 793 (Addr)roffset, (Addr) 794 (roffset - basebgn), name)); 795 continue; 796 } 797 } 798 799 /* 800 * If symbol was found in an object 801 * other than the referencing object 802 * then record the binding. 803 */ 804 if ((lmp != _lmp) && ((FLAGS1(_lmp) & 805 FL1_RT_NOINIFIN) == 0)) { 806 if (alist_test(&bound, _lmp, 807 sizeof (Rt_map *), 808 AL_CNT_RELBIND) == 0) { 809 ret = 0; 810 break; 811 } 812 } 813 814 /* 815 * Calculate the location of definition; 816 * symbol value plus base address of 817 * containing shared object. 818 */ 819 value = symdef->st_value; 820 if (!(FLAGS(_lmp) & FLG_RT_FIXED) && 821 (symdef->st_shndx != SHN_ABS) && 822 (ELF_ST_TYPE(symdef->st_info) != 823 STT_TLS)) 824 value += ADDR(_lmp); 825 826 /* 827 * Retain this symbol index and the 828 * value in case it can be used for the 829 * subsequent relocations. 830 */ 831 if (rtype != R_386_COPY) { 832 psymndx = rsymndx; 833 pvalue = value; 834 pname = name; 835 psymdef = symdef; 836 psymref = symref; 837 plmp = _lmp; 838 pbinfo = binfo; 839 } 840 if ((LIST(_lmp)->lm_tflags | 841 FLAGS1(_lmp)) & 842 LML_TFLG_AUD_SYMBIND) { 843 dsymndx = (((uintptr_t)symdef - 844 (uintptr_t)SYMTAB(_lmp)) / 845 SYMENT(_lmp)); 846 value = audit_symbind(lmp, _lmp, 847 symdef, dsymndx, value, 848 &sb_flags); 849 } 850 } 851 852 /* 853 * If relocation is PC-relative, subtract 854 * offset address. 855 */ 856 if (IS_PC_RELATIVE(rtype)) 857 value -= roffset; 858 859 /* 860 * TLS relocation - value for DTPMOD32 861 * relocation is the TLS modid. 862 */ 863 if (rtype == R_386_TLS_DTPMOD32) 864 value = TLSMODID(_lmp); 865 else if (rtype == R_386_TLS_TPOFF) 866 value = -(TLSSTATOFF(_lmp) - value); 867 } 868 } else { 869 /* 870 * Special case: 871 * 872 * A DTPMOD32 relocation is a local binding to a TLS 873 * symbol. Fill in the TLSMODID for the current object. 874 */ 875 if (rtype == R_386_TLS_DTPMOD32) 876 value = TLSMODID(lmp); 877 else 878 value = basebgn; 879 name = (char *)0; 880 } 881 882 /* 883 * If this object has relocations in the text segment, turn 884 * off the write protect. 885 */ 886 if ((roffset < etext) && (textrel == 0)) { 887 if (elf_set_prot(lmp, PROT_WRITE) == 0) { 888 ret = 0; 889 break; 890 } 891 textrel = 1; 892 } 893 894 /* 895 * Call relocation routine to perform required relocation. 896 */ 897 DBG_CALL(Dbg_reloc_in(LIST(lmp), ELF_DBG_RTLD, M_MACH, 898 M_REL_SHT_TYPE, rel, NULL, name)); 899 900 switch (rtype) { 901 case R_386_COPY: 902 if (elf_copy_reloc(name, symref, lmp, (void *)roffset, 903 symdef, _lmp, (const void *)value) == 0) 904 ret = 0; 905 break; 906 case R_386_JMP_SLOT: 907 if (((LIST(lmp)->lm_tflags | FLAGS1(lmp)) & 908 (LML_TFLG_AUD_PLTENTER | LML_TFLG_AUD_PLTEXIT)) && 909 AUDINFO(lmp)->ai_dynplts) { 910 int fail = 0; 911 int pltndx = (((ulong_t)rel - 912 (uintptr_t)JMPREL(lmp)) / relsiz); 913 int symndx = (((uintptr_t)symdef - 914 (uintptr_t)SYMTAB(_lmp)) / 915 SYMENT(_lmp)); 916 917 (void) elf_plt_trace_write(roffset, lmp, _lmp, 918 symdef, symndx, pltndx, (caddr_t)value, 919 sb_flags, &fail); 920 if (fail) 921 ret = 0; 922 } else { 923 /* 924 * Write standard PLT entry to jump directly 925 * to newly bound function. 926 */ 927 DBG_CALL(Dbg_reloc_apply_val(LIST(lmp), 928 ELF_DBG_RTLD, (Xword)roffset, 929 (Xword)value)); 930 *(ulong_t *)roffset = value; 931 } 932 break; 933 default: 934 /* 935 * Write the relocation out. 936 */ 937 if (do_reloc(rtype, (uchar_t *)roffset, (Word *)&value, 938 name, NAME(lmp), LIST(lmp)) == 0) 939 ret = 0; 940 941 DBG_CALL(Dbg_reloc_apply_val(LIST(lmp), ELF_DBG_RTLD, 942 (Xword)roffset, (Xword)value)); 943 } 944 945 if ((ret == 0) && 946 ((LIST(lmp)->lm_flags & LML_FLG_TRC_WARN) == 0)) 947 break; 948 949 if (binfo) { 950 DBG_CALL(Dbg_bind_global(lmp, (Addr)roffset, 951 (Off)(roffset - basebgn), (Xword)(-1), PLT_T_FULL, 952 _lmp, (Addr)value, symdef->st_value, name, binfo)); 953 } 954 } 955 956 return (relocate_finish(lmp, bound, textrel, ret)); 957 } 958 959 /* 960 * Initialize the first few got entries so that function calls go to 961 * elf_rtbndr: 962 * 963 * GOT[GOT_XLINKMAP] = the address of the link map 964 * GOT[GOT_XRTLD] = the address of rtbinder 965 */ 966 void 967 elf_plt_init(void *got, caddr_t l) 968 { 969 uint_t *_got; 970 /* LINTED */ 971 Rt_map *lmp = (Rt_map *)l; 972 973 _got = (uint_t *)got + M_GOT_XLINKMAP; 974 *_got = (uint_t)lmp; 975 _got = (uint_t *)got + M_GOT_XRTLD; 976 *_got = (uint_t)elf_rtbndr; 977 } 978 979 /* 980 * For SVR4 Intel compatability. USL uses /usr/lib/libc.so.1 as the run-time 981 * linker, so the interpreter's address will differ from /usr/lib/ld.so.1. 982 * Further, USL has special _iob[] and _ctype[] processing that makes up for the 983 * fact that these arrays do not have associated copy relocations. So we try 984 * and make up for that here. Any relocations found will be added to the global 985 * copy relocation list and will be processed in setup(). 986 */ 987 static int 988 _elf_copy_reloc(const char *name, Rt_map *rlmp, Rt_map *dlmp) 989 { 990 Sym *symref, *symdef; 991 caddr_t ref, def; 992 Rt_map *_lmp; 993 Rel rel; 994 Slookup sl; 995 uint_t binfo; 996 997 /* 998 * Determine if the special symbol exists as a reference in the dynamic 999 * executable, and that an associated definition exists in libc.so.1. 1000 */ 1001 sl.sl_name = name; 1002 sl.sl_cmap = rlmp; 1003 sl.sl_imap = rlmp; 1004 sl.sl_hash = 0; 1005 sl.sl_rsymndx = 0; 1006 sl.sl_flags = LKUP_FIRST; 1007 1008 if ((symref = lookup_sym(&sl, &_lmp, &binfo)) == 0) 1009 return (1); 1010 1011 sl.sl_imap = dlmp; 1012 sl.sl_flags = LKUP_DEFT; 1013 1014 if ((symdef = lookup_sym(&sl, &_lmp, &binfo)) == 0) 1015 return (1); 1016 if (strcmp(NAME(_lmp), MSG_ORIG(MSG_PTH_LIBC))) 1017 return (1); 1018 1019 /* 1020 * Determine the reference and definition addresses. 1021 */ 1022 ref = (void *)(symref->st_value); 1023 if (!(FLAGS(rlmp) & FLG_RT_FIXED)) 1024 ref += ADDR(rlmp); 1025 def = (void *)(symdef->st_value); 1026 if (!(FLAGS(_lmp) & FLG_RT_FIXED)) 1027 def += ADDR(_lmp); 1028 1029 /* 1030 * Set up a relocation entry for debugging and call the generic copy 1031 * relocation function to provide symbol size error checking and to 1032 * record the copy relocation that must be performed. 1033 */ 1034 rel.r_offset = (Addr)ref; 1035 rel.r_info = (Word)R_386_COPY; 1036 DBG_CALL(Dbg_reloc_in(LIST(rlmp), ELF_DBG_RTLD, M_MACH, M_REL_SHT_TYPE, 1037 &rel, NULL, name)); 1038 1039 return (elf_copy_reloc((char *)name, symref, rlmp, (void *)ref, symdef, 1040 _lmp, (void *)def)); 1041 } 1042 1043 int 1044 elf_copy_gen(Rt_map *lmp) 1045 { 1046 if (interp && ((ulong_t)interp->i_faddr != 1047 r_debug.rtd_rdebug.r_ldbase) && 1048 !(strcmp(interp->i_name, MSG_ORIG(MSG_PTH_LIBC)))) { 1049 1050 DBG_CALL(Dbg_reloc_run(lmp, M_REL_SHT_TYPE, 0, 1051 DBG_REL_START)); 1052 1053 if (_elf_copy_reloc(MSG_ORIG(MSG_SYM_CTYPE), lmp, 1054 (Rt_map *)NEXT(lmp)) == 0) 1055 return (0); 1056 if (_elf_copy_reloc(MSG_ORIG(MSG_SYM_IOB), lmp, 1057 (Rt_map *)NEXT(lmp)) == 0) 1058 return (0); 1059 } 1060 return (1); 1061 } 1062 1063 /* 1064 * Plt writing interface to allow debugging initialization to be generic. 1065 */ 1066 Pltbindtype 1067 /* ARGSUSED1 */ 1068 elf_plt_write(uintptr_t addr, uintptr_t vaddr, void *rptr, uintptr_t symval, 1069 Xword pltndx) 1070 { 1071 Rel *rel = (Rel*)rptr; 1072 uintptr_t pltaddr; 1073 1074 pltaddr = addr + rel->r_offset; 1075 *(ulong_t *)pltaddr = (ulong_t)symval; 1076 DBG_CALL(pltcntfull++); 1077 return (PLT_T_FULL); 1078 } 1079 1080 /* 1081 * Provide a machine specific interface to the conversion routine. By calling 1082 * the machine specific version, rather than the generic version, we insure that 1083 * the data tables/strings for all known machine versions aren't dragged into 1084 * ld.so.1. 1085 */ 1086 const char * 1087 _conv_reloc_type(uint_t rel) 1088 { 1089 return (conv_reloc_386_type(rel, 0)); 1090 } 1091