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 *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 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 sym = (Sym *)((ulong_t)SYMTAB(lmp) + (rsymndx * SYMENT(lmp))); 242 name = (char *)(STRTAB(lmp) + sym->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_flags = LKUP_DEFT; 259 260 if ((nsym = lookup_sym(&sl, &nlmp, &binfo)) == 0) { 261 eprintf(lml, ERR_FATAL, MSG_INTL(MSG_REL_NOSYM), NAME(lmp), 262 demangle(name)); 263 rtldexit(lml, 1); 264 } 265 266 symval = nsym->st_value; 267 if (!(FLAGS(nlmp) & FLG_RT_FIXED) && 268 (nsym->st_shndx != SHN_ABS)) 269 symval += ADDR(nlmp); 270 if ((lmp != nlmp) && ((FLAGS1(nlmp) & FL1_RT_NOINIFIN) == 0)) { 271 /* 272 * Record that this new link map is now bound to the caller. 273 */ 274 if (bind_one(lmp, nlmp, BND_REFER) == 0) 275 rtldexit(lml, 1); 276 } 277 278 if ((lml->lm_tflags | FLAGS1(lmp)) & LML_TFLG_AUD_SYMBIND) { 279 uint_t symndx = (((uintptr_t)nsym - 280 (uintptr_t)SYMTAB(nlmp)) / SYMENT(nlmp)); 281 symval = audit_symbind(lmp, nlmp, nsym, symndx, symval, 282 &sb_flags); 283 } 284 285 if (!(rtld_flags & RT_FL_NOBIND)) { 286 addr = rptr->r_offset; 287 if (!(FLAGS(lmp) & FLG_RT_FIXED)) 288 addr += ADDR(lmp); 289 if (((lml->lm_tflags | FLAGS1(lmp)) & 290 (LML_TFLG_AUD_PLTENTER | LML_TFLG_AUD_PLTEXIT)) && 291 AUDINFO(lmp)->ai_dynplts) { 292 int fail = 0; 293 uint_t pltndx = reloff / sizeof (Rel); 294 uint_t symndx = (((uintptr_t)nsym - 295 (uintptr_t)SYMTAB(nlmp)) / SYMENT(nlmp)); 296 297 symval = (ulong_t)elf_plt_trace_write(addr, lmp, nlmp, 298 nsym, symndx, pltndx, (caddr_t)symval, sb_flags, 299 &fail); 300 if (fail) 301 rtldexit(lml, 1); 302 } else { 303 /* 304 * Write standard PLT entry to jump directly 305 * to newly bound function. 306 */ 307 *(ulong_t *)addr = symval; 308 } 309 } 310 311 /* 312 * Print binding information and rebuild PLT entry. 313 */ 314 DBG_CALL(Dbg_bind_global(lmp, (Addr)from, (Off)(from - ADDR(lmp)), 315 (Xword)(reloff / sizeof (Rel)), PLT_T_FULL, nlmp, (Addr)symval, 316 nsym->st_value, name, binfo)); 317 318 /* 319 * Complete any processing for newly loaded objects. Note we don't 320 * know exactly where any new objects are loaded (we know the object 321 * that supplied the symbol, but others may have been loaded lazily as 322 * we searched for the symbol), so sorting starts from the last 323 * link-map know on entry to this routine. 324 */ 325 if (entry) 326 load_completion(llmp); 327 328 /* 329 * Some operations like dldump() or dlopen()'ing a relocatable object 330 * result in objects being loaded on rtld's link-map, make sure these 331 * objects are initialized also. 332 */ 333 if ((LIST(nlmp)->lm_flags & LML_FLG_RTLDLM) && LIST(nlmp)->lm_init) 334 load_completion(nlmp); 335 336 /* 337 * If the object we've bound to is in the process of being initialized 338 * by another thread, determine whether we should block. 339 */ 340 is_dep_ready(nlmp, lmp, DBG_WAIT_SYMBOL); 341 342 /* 343 * Make sure the object to which we've bound has had it's .init fired. 344 * Cleanup before return to user code. 345 */ 346 if (entry) { 347 is_dep_init(nlmp, lmp); 348 leave(lml); 349 } 350 351 if (lmflags & LML_FLG_RTLDLM) 352 dbg_desc->d_class = dbg_class; 353 354 return (symval); 355 } 356 357 358 /* 359 * When the relocation loop realizes that it's dealing with relative 360 * relocations in a shared object, it breaks into this tighter loop 361 * as an optimization. 362 */ 363 ulong_t 364 elf_reloc_relative(ulong_t relbgn, ulong_t relend, ulong_t relsiz, 365 ulong_t basebgn, ulong_t etext, ulong_t emap) 366 { 367 ulong_t roffset = ((Rel *)relbgn)->r_offset; 368 char rtype; 369 370 do { 371 roffset += basebgn; 372 373 /* 374 * If this relocation is against an address not mapped in, 375 * then break out of the relative relocation loop, falling 376 * back on the main relocation loop. 377 */ 378 if (roffset < etext || roffset > emap) 379 break; 380 381 /* 382 * Perform the actual relocation. 383 */ 384 *((ulong_t *)roffset) += basebgn; 385 386 relbgn += relsiz; 387 388 if (relbgn >= relend) 389 break; 390 391 rtype = ELF_R_TYPE(((Rel *)relbgn)->r_info); 392 roffset = ((Rel *)relbgn)->r_offset; 393 394 } while (rtype == R_386_RELATIVE); 395 396 return (relbgn); 397 } 398 399 /* 400 * This is the tightest loop for RELATIVE relocations for those 401 * objects built with the DT_RELACOUNT .dynamic entry. 402 */ 403 ulong_t 404 elf_reloc_relacount(ulong_t relbgn, ulong_t relacount, ulong_t relsiz, 405 ulong_t basebgn) 406 { 407 ulong_t roffset = ((Rel *) relbgn)->r_offset; 408 409 for (; relacount; relacount--) { 410 roffset += basebgn; 411 412 /* 413 * Perform the actual relocation. 414 */ 415 *((ulong_t *)roffset) += basebgn; 416 417 relbgn += relsiz; 418 419 roffset = ((Rel *)relbgn)->r_offset; 420 421 } 422 423 return (relbgn); 424 } 425 426 /* 427 * Read and process the relocations for one link object, we assume all 428 * relocation sections for loadable segments are stored contiguously in 429 * the file. 430 */ 431 int 432 elf_reloc(Rt_map *lmp, uint_t plt) 433 { 434 ulong_t relbgn, relend, relsiz, basebgn; 435 ulong_t pltbgn, pltend, _pltbgn, _pltend; 436 ulong_t roffset, rsymndx, psymndx = 0, etext = ETEXT(lmp); 437 ulong_t emap, dsymndx; 438 uchar_t rtype; 439 long value, pvalue; 440 Sym *symref, *psymref, *symdef, *psymdef; 441 char *name, *pname; 442 Rt_map *_lmp, *plmp; 443 int textrel = 0, ret = 1, noplt = 0; 444 int relacount = RELACOUNT(lmp), plthint = 0; 445 Rel *rel; 446 uint_t binfo, pbinfo; 447 Alist *bound = 0; 448 449 /* 450 * Although only necessary for lazy binding, initialize the first 451 * global offset entry to go to elf_rtbndr(). dbx(1) seems 452 * to find this useful. 453 */ 454 if ((plt == 0) && PLTGOT(lmp)) { 455 if ((ulong_t)PLTGOT(lmp) < etext) { 456 if (elf_set_prot(lmp, PROT_WRITE) == 0) 457 return (0); 458 textrel = 1; 459 } 460 elf_plt_init(PLTGOT(lmp), (caddr_t)lmp); 461 } 462 463 /* 464 * Initialize the plt start and end addresses. 465 */ 466 if ((pltbgn = (ulong_t)JMPREL(lmp)) != 0) 467 pltend = pltbgn + (ulong_t)(PLTRELSZ(lmp)); 468 469 470 relsiz = (ulong_t)(RELENT(lmp)); 471 basebgn = ADDR(lmp); 472 emap = ADDR(lmp) + MSIZE(lmp); 473 474 if (PLTRELSZ(lmp)) 475 plthint = PLTRELSZ(lmp) / relsiz; 476 477 /* 478 * If we've been called upon to promote an RTLD_LAZY object to an 479 * RTLD_NOW then we're only interested in scaning the .plt table. 480 * An uninitialized .plt is the case where the associated got entry 481 * points back to the plt itself. Determine the range of the real .plt 482 * entries using the _PROCEDURE_LINKAGE_TABLE_ symbol. 483 */ 484 if (plt) { 485 Slookup sl; 486 487 relbgn = pltbgn; 488 relend = pltend; 489 if (!relbgn || (relbgn == relend)) 490 return (1); 491 492 sl.sl_name = MSG_ORIG(MSG_SYM_PLT); 493 sl.sl_cmap = lmp; 494 sl.sl_imap = lmp; 495 sl.sl_hash = elf_hash(MSG_ORIG(MSG_SYM_PLT)); 496 sl.sl_rsymndx = 0; 497 sl.sl_flags = LKUP_DEFT; 498 499 if ((symdef = elf_find_sym(&sl, &_lmp, &binfo)) == 0) 500 return (1); 501 502 _pltbgn = symdef->st_value; 503 if (!(FLAGS(lmp) & FLG_RT_FIXED) && 504 (symdef->st_shndx != SHN_ABS)) 505 _pltbgn += basebgn; 506 _pltend = _pltbgn + (((PLTRELSZ(lmp) / relsiz)) * 507 M_PLT_ENTSIZE) + M_PLT_RESERVSZ; 508 509 } else { 510 /* 511 * The relocation sections appear to the run-time linker as a 512 * single table. Determine the address of the beginning and end 513 * of this table. There are two different interpretations of 514 * the ABI at this point: 515 * 516 * o The REL table and its associated RELSZ indicate the 517 * concatenation of *all* relocation sections (this is the 518 * model our link-editor constructs). 519 * 520 * o The REL table and its associated RELSZ indicate the 521 * concatenation of all *but* the .plt relocations. These 522 * relocations are specified individually by the JMPREL and 523 * PLTRELSZ entries. 524 * 525 * Determine from our knowledege of the relocation range and 526 * .plt range, the range of the total relocation table. Note 527 * that one other ABI assumption seems to be that the .plt 528 * relocations always follow any other relocations, the 529 * following range checking drops that assumption. 530 */ 531 relbgn = (ulong_t)(REL(lmp)); 532 relend = relbgn + (ulong_t)(RELSZ(lmp)); 533 if (pltbgn) { 534 if (!relbgn || (relbgn > pltbgn)) 535 relbgn = pltbgn; 536 if (!relbgn || (relend < pltend)) 537 relend = pltend; 538 } 539 } 540 if (!relbgn || (relbgn == relend)) { 541 DBG_CALL(Dbg_reloc_run(lmp, 0, plt, DBG_REL_NONE)); 542 return (1); 543 } 544 DBG_CALL(Dbg_reloc_run(lmp, M_REL_SHT_TYPE, plt, DBG_REL_START)); 545 546 /* 547 * If we're processing a dynamic executable in lazy mode there is no 548 * need to scan the .rel.plt table, however if we're processing a shared 549 * object in lazy mode the .got addresses associated to each .plt must 550 * be relocated to reflect the location of the shared object. 551 */ 552 if (pltbgn && ((MODE(lmp) & RTLD_NOW) == 0) && 553 (FLAGS(lmp) & FLG_RT_FIXED)) 554 noplt = 1; 555 556 /* 557 * Loop through relocations. 558 */ 559 while (relbgn < relend) { 560 uint_t sb_flags = 0; 561 562 rtype = ELF_R_TYPE(((Rel *)relbgn)->r_info); 563 564 /* 565 * If this is a RELATIVE relocation in a shared object (the 566 * common case), and if we are not debugging, then jump into a 567 * tighter relocation loop (elf_reloc_relative). Only make the 568 * jump if we've been given a hint on the number of relocations. 569 */ 570 if ((rtype == R_386_RELATIVE) && 571 ((FLAGS(lmp) & FLG_RT_FIXED) == 0) && (DBG_ENABLED == 0)) { 572 /* 573 * It's possible that the relative relocation block 574 * has relocations against the text segment as well 575 * as the data segment. Since our optimized relocation 576 * engine does not check which segment the relocation 577 * is against - just mprotect it now if it's been 578 * marked as containing TEXTREL's. 579 */ 580 if ((textrel == 0) && (FLAGS1(lmp) & FL1_RT_TEXTREL)) { 581 if (elf_set_prot(lmp, PROT_WRITE) == 0) { 582 ret = 0; 583 break; 584 } 585 textrel = 1; 586 } 587 588 if (relacount) { 589 relbgn = elf_reloc_relacount(relbgn, relacount, 590 relsiz, basebgn); 591 relacount = 0; 592 } else { 593 relbgn = elf_reloc_relative(relbgn, relend, 594 relsiz, basebgn, etext, emap); 595 } 596 if (relbgn >= relend) 597 break; 598 rtype = ELF_R_TYPE(((Rel *)relbgn)->r_info); 599 } 600 601 roffset = ((Rel *)relbgn)->r_offset; 602 603 /* 604 * If this is a shared object, add the base address to offset. 605 */ 606 if (!(FLAGS(lmp) & FLG_RT_FIXED)) { 607 608 /* 609 * If we're processing lazy bindings, we have to step 610 * through the plt entries and add the base address 611 * to the corresponding got entry. 612 */ 613 if (plthint && (plt == 0) && 614 (rtype == R_386_JMP_SLOT) && 615 ((MODE(lmp) & RTLD_NOW) == 0)) { 616 relbgn = elf_reloc_relacount(relbgn, 617 plthint, relsiz, basebgn); 618 plthint = 0; 619 continue; 620 } 621 roffset += basebgn; 622 } 623 624 rsymndx = ELF_R_SYM(((Rel *)relbgn)->r_info); 625 rel = (Rel *)relbgn; 626 relbgn += relsiz; 627 628 /* 629 * Optimizations. 630 */ 631 if (rtype == R_386_NONE) 632 continue; 633 if (noplt && ((ulong_t)rel >= pltbgn) && 634 ((ulong_t)rel < pltend)) { 635 relbgn = pltend; 636 continue; 637 } 638 639 /* 640 * If we're promoting plts determine if this one has already 641 * been written. 642 */ 643 if (plt) { 644 if ((*(ulong_t *)roffset < _pltbgn) || 645 (*(ulong_t *)roffset > _pltend)) 646 continue; 647 } 648 649 /* 650 * If this relocation is not against part of the image 651 * mapped into memory we skip it. 652 */ 653 if ((roffset < ADDR(lmp)) || (roffset > (ADDR(lmp) + 654 MSIZE(lmp)))) { 655 elf_reloc_bad(lmp, (void *)rel, rtype, roffset, 656 rsymndx); 657 continue; 658 } 659 660 binfo = 0; 661 /* 662 * If a symbol index is specified then get the symbol table 663 * entry, locate the symbol definition, and determine its 664 * address. 665 */ 666 if (rsymndx) { 667 /* 668 * Get the local symbol table entry. 669 */ 670 symref = (Sym *)((ulong_t)SYMTAB(lmp) + 671 (rsymndx * SYMENT(lmp))); 672 673 /* 674 * If this is a local symbol, just use the base address. 675 * (we should have no local relocations in the 676 * executable). 677 */ 678 if (ELF_ST_BIND(symref->st_info) == STB_LOCAL) { 679 value = basebgn; 680 name = (char *)0; 681 682 /* 683 * Special case TLS relocations. 684 */ 685 if (rtype == R_386_TLS_DTPMOD32) { 686 /* 687 * Use the TLS modid. 688 */ 689 value = TLSMODID(lmp); 690 691 } else if (rtype == R_386_TLS_TPOFF) { 692 if ((value = elf_static_tls(lmp, symref, 693 rel, rtype, 0, roffset, 0)) == 0) { 694 ret = 0; 695 break; 696 } 697 } 698 } else { 699 /* 700 * If the symbol index is equal to the previous 701 * symbol index relocation we processed then 702 * reuse the previous values. (Note that there 703 * have been cases where a relocation exists 704 * against a copy relocation symbol, our ld(1) 705 * should optimize this away, but make sure we 706 * don't use the same symbol information should 707 * this case exist). 708 */ 709 if ((rsymndx == psymndx) && 710 (rtype != R_386_COPY)) { 711 /* LINTED */ 712 if (psymdef == 0) { 713 DBG_CALL(Dbg_bind_weak(lmp, 714 (Addr)roffset, (Addr) 715 (roffset - basebgn), name)); 716 continue; 717 } 718 /* LINTED */ 719 value = pvalue; 720 /* LINTED */ 721 name = pname; 722 /* LINTED */ 723 symdef = psymdef; 724 /* LINTED */ 725 symref = psymref; 726 /* LINTED */ 727 _lmp = plmp; 728 /* LINTED */ 729 binfo = pbinfo; 730 731 if ((LIST(_lmp)->lm_tflags | 732 FLAGS1(_lmp)) & 733 LML_TFLG_AUD_SYMBIND) { 734 value = audit_symbind(lmp, _lmp, 735 /* LINTED */ 736 symdef, dsymndx, value, 737 &sb_flags); 738 } 739 } else { 740 Slookup sl; 741 uchar_t bind; 742 743 /* 744 * Lookup the symbol definition. 745 */ 746 name = (char *)(STRTAB(lmp) + 747 symref->st_name); 748 749 sl.sl_name = name; 750 sl.sl_cmap = lmp; 751 sl.sl_imap = 0; 752 sl.sl_hash = 0; 753 sl.sl_rsymndx = rsymndx; 754 755 if (rtype == R_386_COPY) 756 sl.sl_flags = LKUP_COPY; 757 else 758 sl.sl_flags = LKUP_DEFT; 759 760 sl.sl_flags |= LKUP_ALLCNTLIST; 761 762 if (rtype != R_386_JMP_SLOT) 763 sl.sl_flags |= LKUP_SPEC; 764 765 /* 766 * Under ldd -w, any unresolved weak 767 * references are diagnosed. Set the 768 * symbol binding as global to trigger 769 * a relocation error if the symbol can 770 * not be found. 771 */ 772 if (LIST(lmp)->lm_flags & 773 LML_FLG_TRC_NOUNRESWEAK) { 774 bind = STB_GLOBAL; 775 } else if ((bind = 776 ELF_ST_BIND(symref->st_info)) == 777 STB_WEAK) { 778 sl.sl_flags |= LKUP_WEAK; 779 } 780 781 symdef = lookup_sym(&sl, &_lmp, &binfo); 782 783 /* 784 * If the symbol is not found and the 785 * reference was not to a weak symbol, 786 * report an error. Weak references 787 * may be unresolved. 788 * chkmsg: MSG_INTL(MSG_LDD_SYM_NFOUND) 789 */ 790 /* BEGIN CSTYLED */ 791 if (symdef == 0) { 792 Lm_list *lml = LIST(lmp); 793 794 if (bind != STB_WEAK) { 795 if (lml->lm_flags & 796 LML_FLG_IGNRELERR) { 797 continue; 798 } else if (lml->lm_flags & 799 LML_FLG_TRC_WARN) { 800 (void) printf(MSG_INTL( 801 MSG_LDD_SYM_NFOUND), 802 demangle(name), 803 NAME(lmp)); 804 continue; 805 } else { 806 DBG_CALL(Dbg_reloc_in(lml, 807 ELF_DBG_RTLD, M_MACH, 808 M_REL_SHT_TYPE, rel, 809 NULL, name)); 810 eprintf(lml, ERR_FATAL, 811 MSG_INTL(MSG_REL_NOSYM), 812 NAME(lmp), 813 demangle(name)); 814 ret = 0; 815 break; 816 } 817 } else { 818 psymndx = rsymndx; 819 psymdef = 0; 820 821 DBG_CALL(Dbg_bind_weak(lmp, 822 (Addr)roffset, (Addr) 823 (roffset - basebgn), name)); 824 continue; 825 } 826 } 827 /* END CSTYLED */ 828 829 /* 830 * If symbol was found in an object 831 * other than the referencing object 832 * then record the binding. 833 */ 834 if ((lmp != _lmp) && ((FLAGS1(_lmp) & 835 FL1_RT_NOINIFIN) == 0)) { 836 if (alist_test(&bound, _lmp, 837 sizeof (Rt_map *), 838 AL_CNT_RELBIND) == 0) { 839 ret = 0; 840 break; 841 } 842 } 843 844 /* 845 * Calculate the location of definition; 846 * symbol value plus base address of 847 * containing shared object. 848 */ 849 if (IS_SIZE(rtype)) 850 value = symdef->st_size; 851 else 852 value = symdef->st_value; 853 854 if (!(FLAGS(_lmp) & FLG_RT_FIXED) && 855 !(IS_SIZE(rtype)) && 856 (symdef->st_shndx != SHN_ABS) && 857 (ELF_ST_TYPE(symdef->st_info) != 858 STT_TLS)) 859 value += ADDR(_lmp); 860 861 /* 862 * Retain this symbol index and the 863 * value in case it can be used for the 864 * subsequent relocations. 865 */ 866 if (rtype != R_386_COPY) { 867 psymndx = rsymndx; 868 pvalue = value; 869 pname = name; 870 psymdef = symdef; 871 psymref = symref; 872 plmp = _lmp; 873 pbinfo = binfo; 874 } 875 if ((LIST(_lmp)->lm_tflags | 876 FLAGS1(_lmp)) & 877 LML_TFLG_AUD_SYMBIND) { 878 dsymndx = (((uintptr_t)symdef - 879 (uintptr_t)SYMTAB(_lmp)) / 880 SYMENT(_lmp)); 881 value = audit_symbind(lmp, _lmp, 882 symdef, dsymndx, value, 883 &sb_flags); 884 } 885 } 886 887 /* 888 * If relocation is PC-relative, subtract 889 * offset address. 890 */ 891 if (IS_PC_RELATIVE(rtype)) 892 value -= roffset; 893 894 /* 895 * Special case TLS relocations. 896 */ 897 if (rtype == R_386_TLS_DTPMOD32) { 898 /* 899 * Relocation value is the TLS modid. 900 */ 901 value = TLSMODID(_lmp); 902 903 } else if (rtype == R_386_TLS_TPOFF) { 904 if ((value = elf_static_tls(_lmp, 905 symdef, rel, rtype, name, roffset, 906 value)) == 0) { 907 ret = 0; 908 break; 909 } 910 } 911 } 912 } else { 913 /* 914 * Special cases. 915 */ 916 if (rtype == R_386_TLS_DTPMOD32) { 917 /* 918 * TLS relocation value is the TLS modid. 919 */ 920 value = TLSMODID(lmp); 921 } else 922 value = basebgn; 923 name = (char *)0; 924 } 925 926 DBG_CALL(Dbg_reloc_in(LIST(lmp), ELF_DBG_RTLD, M_MACH, 927 M_REL_SHT_TYPE, rel, NULL, name)); 928 929 /* 930 * If this object has relocations in the text segment, turn 931 * off the write protect. 932 */ 933 if ((roffset < etext) && (textrel == 0)) { 934 if (elf_set_prot(lmp, PROT_WRITE) == 0) { 935 ret = 0; 936 break; 937 } 938 textrel = 1; 939 } 940 941 /* 942 * Call relocation routine to perform required relocation. 943 */ 944 switch (rtype) { 945 case R_386_COPY: 946 if (elf_copy_reloc(name, symref, lmp, (void *)roffset, 947 symdef, _lmp, (const void *)value) == 0) 948 ret = 0; 949 break; 950 case R_386_JMP_SLOT: 951 if (((LIST(lmp)->lm_tflags | FLAGS1(lmp)) & 952 (LML_TFLG_AUD_PLTENTER | LML_TFLG_AUD_PLTEXIT)) && 953 AUDINFO(lmp)->ai_dynplts) { 954 int fail = 0; 955 int pltndx = (((ulong_t)rel - 956 (uintptr_t)JMPREL(lmp)) / relsiz); 957 int symndx = (((uintptr_t)symdef - 958 (uintptr_t)SYMTAB(_lmp)) / SYMENT(_lmp)); 959 960 (void) elf_plt_trace_write(roffset, lmp, _lmp, 961 symdef, symndx, pltndx, (caddr_t)value, 962 sb_flags, &fail); 963 if (fail) 964 ret = 0; 965 } else { 966 /* 967 * Write standard PLT entry to jump directly 968 * to newly bound function. 969 */ 970 DBG_CALL(Dbg_reloc_apply_val(LIST(lmp), 971 ELF_DBG_RTLD, (Xword)roffset, 972 (Xword)value)); 973 *(ulong_t *)roffset = value; 974 } 975 break; 976 default: 977 /* 978 * Write the relocation out. 979 */ 980 if (do_reloc_rtld(rtype, (uchar_t *)roffset, 981 (Word *)&value, name, NAME(lmp), LIST(lmp)) == 0) 982 ret = 0; 983 984 DBG_CALL(Dbg_reloc_apply_val(LIST(lmp), ELF_DBG_RTLD, 985 (Xword)roffset, (Xword)value)); 986 } 987 988 if ((ret == 0) && 989 ((LIST(lmp)->lm_flags & LML_FLG_TRC_WARN) == 0)) 990 break; 991 992 if (binfo) { 993 DBG_CALL(Dbg_bind_global(lmp, (Addr)roffset, 994 (Off)(roffset - basebgn), (Xword)(-1), PLT_T_FULL, 995 _lmp, (Addr)value, symdef->st_value, name, binfo)); 996 } 997 } 998 999 return (relocate_finish(lmp, bound, textrel, ret)); 1000 } 1001 1002 /* 1003 * Initialize the first few got entries so that function calls go to 1004 * elf_rtbndr: 1005 * 1006 * GOT[GOT_XLINKMAP] = the address of the link map 1007 * GOT[GOT_XRTLD] = the address of rtbinder 1008 */ 1009 void 1010 elf_plt_init(void *got, caddr_t l) 1011 { 1012 uint_t *_got; 1013 /* LINTED */ 1014 Rt_map *lmp = (Rt_map *)l; 1015 1016 _got = (uint_t *)got + M_GOT_XLINKMAP; 1017 *_got = (uint_t)lmp; 1018 _got = (uint_t *)got + M_GOT_XRTLD; 1019 *_got = (uint_t)elf_rtbndr; 1020 } 1021 1022 /* 1023 * For SVR4 Intel compatability. USL uses /usr/lib/libc.so.1 as the run-time 1024 * linker, so the interpreter's address will differ from /usr/lib/ld.so.1. 1025 * Further, USL has special _iob[] and _ctype[] processing that makes up for the 1026 * fact that these arrays do not have associated copy relocations. So we try 1027 * and make up for that here. Any relocations found will be added to the global 1028 * copy relocation list and will be processed in setup(). 1029 */ 1030 static int 1031 _elf_copy_reloc(const char *name, Rt_map *rlmp, Rt_map *dlmp) 1032 { 1033 Sym *symref, *symdef; 1034 caddr_t ref, def; 1035 Rt_map *_lmp; 1036 Rel rel; 1037 Slookup sl; 1038 uint_t binfo; 1039 1040 /* 1041 * Determine if the special symbol exists as a reference in the dynamic 1042 * executable, and that an associated definition exists in libc.so.1. 1043 */ 1044 sl.sl_name = name; 1045 sl.sl_cmap = rlmp; 1046 sl.sl_imap = rlmp; 1047 sl.sl_hash = 0; 1048 sl.sl_rsymndx = 0; 1049 sl.sl_flags = LKUP_FIRST; 1050 1051 if ((symref = lookup_sym(&sl, &_lmp, &binfo)) == 0) 1052 return (1); 1053 1054 sl.sl_imap = dlmp; 1055 sl.sl_flags = LKUP_DEFT; 1056 1057 if ((symdef = lookup_sym(&sl, &_lmp, &binfo)) == 0) 1058 return (1); 1059 if (strcmp(NAME(_lmp), MSG_ORIG(MSG_PTH_LIBC))) 1060 return (1); 1061 1062 /* 1063 * Determine the reference and definition addresses. 1064 */ 1065 ref = (void *)(symref->st_value); 1066 if (!(FLAGS(rlmp) & FLG_RT_FIXED)) 1067 ref += ADDR(rlmp); 1068 def = (void *)(symdef->st_value); 1069 if (!(FLAGS(_lmp) & FLG_RT_FIXED)) 1070 def += ADDR(_lmp); 1071 1072 /* 1073 * Set up a relocation entry for debugging and call the generic copy 1074 * relocation function to provide symbol size error checking and to 1075 * record the copy relocation that must be performed. 1076 */ 1077 rel.r_offset = (Addr)ref; 1078 rel.r_info = (Word)R_386_COPY; 1079 DBG_CALL(Dbg_reloc_in(LIST(rlmp), ELF_DBG_RTLD, M_MACH, M_REL_SHT_TYPE, 1080 &rel, NULL, name)); 1081 1082 return (elf_copy_reloc((char *)name, symref, rlmp, (void *)ref, symdef, 1083 _lmp, (void *)def)); 1084 } 1085 1086 int 1087 elf_copy_gen(Rt_map *lmp) 1088 { 1089 if (interp && ((ulong_t)interp->i_faddr != 1090 r_debug.rtd_rdebug.r_ldbase) && 1091 !(strcmp(interp->i_name, MSG_ORIG(MSG_PTH_LIBC)))) { 1092 1093 DBG_CALL(Dbg_reloc_run(lmp, M_REL_SHT_TYPE, 0, 1094 DBG_REL_START)); 1095 1096 if (_elf_copy_reloc(MSG_ORIG(MSG_SYM_CTYPE), lmp, 1097 (Rt_map *)NEXT(lmp)) == 0) 1098 return (0); 1099 if (_elf_copy_reloc(MSG_ORIG(MSG_SYM_IOB), lmp, 1100 (Rt_map *)NEXT(lmp)) == 0) 1101 return (0); 1102 } 1103 return (1); 1104 } 1105 1106 /* 1107 * Plt writing interface to allow debugging initialization to be generic. 1108 */ 1109 Pltbindtype 1110 /* ARGSUSED1 */ 1111 elf_plt_write(uintptr_t addr, uintptr_t vaddr, void *rptr, uintptr_t symval, 1112 Xword pltndx) 1113 { 1114 Rel *rel = (Rel*)rptr; 1115 uintptr_t pltaddr; 1116 1117 pltaddr = addr + rel->r_offset; 1118 *(ulong_t *)pltaddr = (ulong_t)symval; 1119 DBG_CALL(pltcntfull++); 1120 return (PLT_T_FULL); 1121 } 1122 1123 /* 1124 * Provide a machine specific interface to the conversion routine. By calling 1125 * the machine specific version, rather than the generic version, we insure that 1126 * the data tables/strings for all known machine versions aren't dragged into 1127 * ld.so.1. 1128 */ 1129 const char * 1130 _conv_reloc_type(uint_t rel) 1131 { 1132 static Conv_inv_buf_t inv_buf; 1133 1134 return (conv_reloc_386_type(rel, 0, &inv_buf)); 1135 } 1136