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 2007 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 #pragma ident "%Z%%M% %I% %E% SMI" 27 28 /* 29 * amd64 machine dependent and ELF file class dependent functions. 30 * Contains routines for performing function binding and symbol relocations. 31 */ 32 #include "_synonyms.h" 33 34 #include <stdio.h> 35 #include <sys/elf.h> 36 #include <sys/elf_amd64.h> 37 #include <sys/mman.h> 38 #include <dlfcn.h> 39 #include <synch.h> 40 #include <string.h> 41 #include <debug.h> 42 #include <reloc.h> 43 #include <conv.h> 44 #include "_rtld.h" 45 #include "_audit.h" 46 #include "_elf.h" 47 #include "msg.h" 48 49 50 extern void elf_rtbndr(Rt_map *, ulong_t, caddr_t); 51 52 int 53 elf_mach_flags_check(Rej_desc *rej, Ehdr *ehdr) 54 { 55 /* 56 * Check machine type and flags. 57 */ 58 if (ehdr->e_flags != 0) { 59 rej->rej_type = SGS_REJ_BADFLAG; 60 rej->rej_info = (uint_t)ehdr->e_flags; 61 return (0); 62 } 63 return (1); 64 } 65 66 void 67 ldso_plt_init(Rt_map * lmp) 68 { 69 /* 70 * There is no need to analyze ld.so because we don't map in any of 71 * its dependencies. However we may map these dependencies in later 72 * (as if ld.so had dlopened them), so initialize the plt and the 73 * permission information. 74 */ 75 if (PLTGOT(lmp)) 76 elf_plt_init((void *)(PLTGOT(lmp)), (caddr_t)lmp); 77 } 78 79 static const uchar_t dyn_plt_template[] = { 80 /* 0x00 */ 0x55, /* pushq %rbp */ 81 /* 0x01 */ 0x48, 0x89, 0xe5, /* movq %rsp, %rbp */ 82 /* 0x04 */ 0x48, 0x83, 0xec, 0x10, /* subq $0x10, %rsp */ 83 /* 0x08 */ 0x4c, 0x8d, 0x1d, 0x00, /* leaq trace_fields(%rip), %r11 */ 84 0x00, 0x00, 0x00, 85 /* 0x0f */ 0x4c, 0x89, 0x5d, 0xf8, /* movq %r11, -0x8(%rbp) */ 86 /* 0x13 */ 0x49, 0xbb, 0x00, 0x00, /* movq $elf_plt_trace, %r11 */ 87 0x00, 0x00, 0x00, 88 0x00, 0x00, 0x00, 89 /* 0x1d */ 0x41, 0xff, 0xe3 /* jmp *%r11 */ 90 /* 0x20 */ 91 }; 92 93 /* 94 * And the virutal outstanding relocations against the 95 * above block are: 96 * 97 * reloc offset Addend symbol 98 * R_AMD64_PC32 0x0b -4 trace_fields 99 * R_AMD64_64 0x15 0 elf_plt_trace 100 */ 101 102 #define TRCREL1OFF 0x0b 103 #define TRCREL2OFF 0x15 104 105 int dyn_plt_ent_size = sizeof (dyn_plt_template); 106 107 /* 108 * the dynamic plt entry is: 109 * 110 * pushq %rbp 111 * movq %rsp, %rbp 112 * subq $0x10, %rsp 113 * leaq trace_fields(%rip), %r11 114 * movq %r11, -0x8(%rbp) 115 * movq $elf_plt_trace, %r11 116 * jmp *%r11 117 * dyn_data: 118 * .align 8 119 * uintptr_t reflmp 120 * uintptr_t deflmp 121 * uint_t symndx 122 * uint_t sb_flags 123 * Sym symdef 124 */ 125 static caddr_t 126 elf_plt_trace_write(ulong_t roffset, Rt_map *rlmp, Rt_map *dlmp, Sym *sym, 127 uint_t symndx, uint_t pltndx, caddr_t to, uint_t sb_flags, int *fail) 128 { 129 extern int elf_plt_trace(); 130 ulong_t got_entry; 131 uchar_t *dyn_plt; 132 uintptr_t *dyndata; 133 134 135 /* 136 * We only need to add the glue code if there is an auditing 137 * library that is interested in this binding. 138 */ 139 dyn_plt = (uchar_t *)((uintptr_t)AUDINFO(rlmp)->ai_dynplts + 140 (pltndx * dyn_plt_ent_size)); 141 142 /* 143 * Have we initialized this dynamic plt entry yet? If we haven't do it 144 * now. Otherwise this function has been called before, but from a 145 * different plt (ie. from another shared object). In that case 146 * we just set the plt to point to the new dyn_plt. 147 */ 148 if (*dyn_plt == 0) { 149 Sym * symp; 150 Xword symvalue; 151 Lm_list *lml = LIST(rlmp); 152 153 (void) memcpy((void *)dyn_plt, dyn_plt_template, 154 sizeof (dyn_plt_template)); 155 dyndata = (uintptr_t *)((uintptr_t)dyn_plt + 156 ROUND(sizeof (dyn_plt_template), M_WORD_ALIGN)); 157 158 /* 159 * relocate: 160 * leaq trace_fields(%rip), %r11 161 * R_AMD64_PC32 0x0b -4 trace_fields 162 */ 163 symvalue = (Xword)((uintptr_t)dyndata - 164 (uintptr_t)(&dyn_plt[TRCREL1OFF]) - 4); 165 if (do_reloc(R_AMD64_PC32, &dyn_plt[TRCREL1OFF], 166 &symvalue, MSG_ORIG(MSG_SYM_LADYNDATA), 167 MSG_ORIG(MSG_SPECFIL_DYNPLT), lml) == 0) { 168 *fail = 1; 169 return (0); 170 } 171 172 /* 173 * relocating: 174 * movq $elf_plt_trace, %r11 175 * R_AMD64_64 0x15 0 elf_plt_trace 176 */ 177 symvalue = (Xword)elf_plt_trace; 178 if (do_reloc(R_AMD64_64, &dyn_plt[TRCREL2OFF], 179 &symvalue, MSG_ORIG(MSG_SYM_ELFPLTTRACE), 180 MSG_ORIG(MSG_SPECFIL_DYNPLT), lml) == 0) { 181 *fail = 1; 182 return (0); 183 } 184 185 *dyndata++ = (uintptr_t)rlmp; 186 *dyndata++ = (uintptr_t)dlmp; 187 *dyndata = (uintptr_t)(((uint64_t)sb_flags << 32) | symndx); 188 dyndata++; 189 symp = (Sym *)dyndata; 190 *symp = *sym; 191 symp->st_value = (Addr)to; 192 } 193 194 got_entry = (ulong_t)roffset; 195 *(ulong_t *)got_entry = (ulong_t)dyn_plt; 196 return ((caddr_t)dyn_plt); 197 } 198 199 200 /* 201 * Function binding routine - invoked on the first call to a function through 202 * the procedure linkage table; 203 * passes first through an assembly language interface. 204 * 205 * Takes the offset into the relocation table of the associated 206 * relocation entry and the address of the link map (rt_private_map struct) 207 * for the entry. 208 * 209 * Returns the address of the function referenced after re-writing the PLT 210 * entry to invoke the function directly. 211 * 212 * On error, causes process to terminate with a signal. 213 */ 214 ulong_t 215 elf_bndr(Rt_map *lmp, ulong_t pltndx, caddr_t from) 216 { 217 Rt_map *nlmp, * llmp; 218 ulong_t addr, reloff, symval, rsymndx; 219 char *name; 220 Rela *rptr; 221 Sym *sym, *nsym; 222 uint_t binfo, sb_flags = 0, dbg_class; 223 Slookup sl; 224 int entry, lmflags; 225 Lm_list *lml; 226 227 /* 228 * For compatibility with libthread (TI_VERSION 1) we track the entry 229 * value. A zero value indicates we have recursed into ld.so.1 to 230 * further process a locking request. Under this recursion we disable 231 * tsort and cleanup activities. 232 */ 233 entry = enter(); 234 235 lml = LIST(lmp); 236 if ((lmflags = lml->lm_flags) & LML_FLG_RTLDLM) { 237 dbg_class = dbg_desc->d_class; 238 dbg_desc->d_class = 0; 239 } 240 241 /* 242 * Perform some basic sanity checks. If we didn't get a load map or 243 * the relocation offset is invalid then its possible someone has walked 244 * over the .got entries or jumped to plt0 out of the blue. 245 */ 246 if ((!lmp) && (pltndx <= 247 (ulong_t)PLTRELSZ(lmp) / (ulong_t)RELENT(lmp))) { 248 eprintf(lml, ERR_FATAL, MSG_INTL(MSG_REL_PLTREF), 249 conv_reloc_amd64_type(R_AMD64_JUMP_SLOT, 0), 250 EC_NATPTR(lmp), EC_XWORD(pltndx), EC_NATPTR(from)); 251 rtldexit(lml, 1); 252 } 253 reloff = pltndx * (ulong_t)RELENT(lmp); 254 255 /* 256 * Use relocation entry to get symbol table entry and symbol name. 257 */ 258 addr = (ulong_t)JMPREL(lmp); 259 rptr = (Rela *)(addr + reloff); 260 rsymndx = ELF_R_SYM(rptr->r_info); 261 sym = (Sym *)((ulong_t)SYMTAB(lmp) + (rsymndx * SYMENT(lmp))); 262 name = (char *)(STRTAB(lmp) + sym->st_name); 263 264 /* 265 * Determine the last link-map of this list, this'll be the starting 266 * point for any tsort() processing. 267 */ 268 llmp = lml->lm_tail; 269 270 /* 271 * Find definition for symbol. 272 */ 273 sl.sl_name = name; 274 sl.sl_cmap = lmp; 275 sl.sl_imap = lml->lm_head; 276 sl.sl_hash = 0; 277 sl.sl_rsymndx = rsymndx; 278 sl.sl_flags = LKUP_DEFT; 279 280 if ((nsym = lookup_sym(&sl, &nlmp, &binfo)) == 0) { 281 eprintf(lml, ERR_FATAL, MSG_INTL(MSG_REL_NOSYM), NAME(lmp), 282 demangle(name)); 283 rtldexit(lml, 1); 284 } 285 286 symval = nsym->st_value; 287 if (!(FLAGS(nlmp) & FLG_RT_FIXED) && 288 (nsym->st_shndx != SHN_ABS)) 289 symval += ADDR(nlmp); 290 if ((lmp != nlmp) && ((FLAGS1(nlmp) & FL1_RT_NOINIFIN) == 0)) { 291 /* 292 * Record that this new link map is now bound to the caller. 293 */ 294 if (bind_one(lmp, nlmp, BND_REFER) == 0) 295 rtldexit(lml, 1); 296 } 297 298 if ((lml->lm_tflags | FLAGS1(lmp)) & LML_TFLG_AUD_SYMBIND) { 299 uint_t symndx = (((uintptr_t)nsym - 300 (uintptr_t)SYMTAB(nlmp)) / SYMENT(nlmp)); 301 symval = audit_symbind(lmp, nlmp, nsym, symndx, symval, 302 &sb_flags); 303 } 304 305 if (!(rtld_flags & RT_FL_NOBIND)) { 306 addr = rptr->r_offset; 307 if (!(FLAGS(lmp) & FLG_RT_FIXED)) 308 addr += ADDR(lmp); 309 if (((lml->lm_tflags | FLAGS1(lmp)) & 310 (LML_TFLG_AUD_PLTENTER | LML_TFLG_AUD_PLTEXIT)) && 311 AUDINFO(lmp)->ai_dynplts) { 312 int fail = 0; 313 uint_t pltndx = reloff / sizeof (Rela); 314 uint_t symndx = (((uintptr_t)nsym - 315 (uintptr_t)SYMTAB(nlmp)) / SYMENT(nlmp)); 316 317 symval = (ulong_t)elf_plt_trace_write(addr, lmp, nlmp, 318 nsym, symndx, pltndx, (caddr_t)symval, sb_flags, 319 &fail); 320 if (fail) 321 rtldexit(lml, 1); 322 } else { 323 /* 324 * Write standard PLT entry to jump directly 325 * to newly bound function. 326 */ 327 *(ulong_t *)addr = symval; 328 } 329 } 330 331 /* 332 * Print binding information and rebuild PLT entry. 333 */ 334 DBG_CALL(Dbg_bind_global(lmp, (Addr)from, (Off)(from - ADDR(lmp)), 335 (Xword)(reloff / sizeof (Rela)), PLT_T_FULL, nlmp, 336 (Addr)symval, nsym->st_value, name, binfo)); 337 338 /* 339 * Complete any processing for newly loaded objects. Note we don't 340 * know exactly where any new objects are loaded (we know the object 341 * that supplied the symbol, but others may have been loaded lazily as 342 * we searched for the symbol), so sorting starts from the last 343 * link-map know on entry to this routine. 344 */ 345 if (entry) 346 load_completion(llmp); 347 348 /* 349 * Some operations like dldump() or dlopen()'ing a relocatable object 350 * result in objects being loaded on rtld's link-map, make sure these 351 * objects are initialized also. 352 */ 353 if ((lml->lm_flags & LML_FLG_RTLDLM) && LIST(nlmp)->lm_init) 354 load_completion(nlmp); 355 356 /* 357 * If the object we've bound to is in the process of being initialized 358 * by another thread, determine whether we should block. 359 */ 360 is_dep_ready(nlmp, lmp, DBG_WAIT_SYMBOL); 361 362 /* 363 * Make sure the object to which we've bound has had it's .init fired. 364 * Cleanup before return to user code. 365 */ 366 if (entry) { 367 is_dep_init(nlmp, lmp); 368 leave(lml); 369 } 370 371 if (lmflags & LML_FLG_RTLDLM) 372 dbg_desc->d_class = dbg_class; 373 374 return (symval); 375 } 376 377 378 /* 379 * When the relocation loop realizes that it's dealing with relative 380 * relocations in a shared object, it breaks into this tighter loop 381 * as an optimization. 382 */ 383 ulong_t 384 elf_reloc_relative(ulong_t relbgn, ulong_t relend, ulong_t relsiz, 385 ulong_t basebgn, ulong_t etext, ulong_t emap) 386 { 387 ulong_t roffset = ((Rela *)relbgn)->r_offset; 388 char rtype; 389 390 do { 391 roffset += basebgn; 392 393 /* 394 * If this relocation is against an address not mapped in, 395 * then break out of the relative relocation loop, falling 396 * back on the main relocation loop. 397 */ 398 if (roffset < etext || roffset > emap) 399 break; 400 401 /* 402 * Perform the actual relocation. 403 */ 404 *((ulong_t *)roffset) = basebgn + 405 ((Rela *)relbgn)->r_addend; 406 407 relbgn += relsiz; 408 409 if (relbgn >= relend) 410 break; 411 412 rtype = ELF_R_TYPE(((Rela *)relbgn)->r_info); 413 roffset = ((Rela *)relbgn)->r_offset; 414 415 } while (rtype == R_AMD64_RELATIVE); 416 417 return (relbgn); 418 } 419 420 /* 421 * This is the tightest loop for RELATIVE relocations for those 422 * objects built with the DT_RELACOUNT .dynamic entry. 423 */ 424 ulong_t 425 elf_reloc_relacount(ulong_t relbgn, ulong_t relacount, ulong_t relsiz, 426 ulong_t basebgn) 427 { 428 ulong_t roffset = ((Rela *) relbgn)->r_offset; 429 430 for (; relacount; relacount--) { 431 roffset += basebgn; 432 433 /* 434 * Perform the actual relocation. 435 */ 436 *((ulong_t *)roffset) = basebgn + 437 ((Rela *)relbgn)->r_addend; 438 439 relbgn += relsiz; 440 441 roffset = ((Rela *)relbgn)->r_offset; 442 443 } 444 445 return (relbgn); 446 } 447 448 /* 449 * Read and process the relocations for one link object, we assume all 450 * relocation sections for loadable segments are stored contiguously in 451 * the file. 452 */ 453 int 454 elf_reloc(Rt_map *lmp, uint_t plt) 455 { 456 ulong_t relbgn, relend, relsiz, basebgn; 457 ulong_t pltbgn, pltend, _pltbgn, _pltend; 458 ulong_t roffset, rsymndx, psymndx = 0, etext = ETEXT(lmp); 459 ulong_t emap, dsymndx; 460 uchar_t rtype; 461 long reladd, value, pvalue; 462 Sym *symref, *psymref, *symdef, *psymdef; 463 char *name, *pname; 464 Rt_map *_lmp, *plmp; 465 int textrel = 0, ret = 1, noplt = 0; 466 int relacount = RELACOUNT(lmp), plthint = 0; 467 Rela *rel; 468 uint_t binfo, pbinfo; 469 Alist *bound = 0; 470 471 /* 472 * Although only necessary for lazy binding, initialize the first 473 * global offset entry to go to elf_rtbndr(). dbx(1) seems 474 * to find this useful. 475 */ 476 if ((plt == 0) && PLTGOT(lmp)) { 477 if ((ulong_t)PLTGOT(lmp) < etext) { 478 if (elf_set_prot(lmp, PROT_WRITE) == 0) 479 return (0); 480 textrel = 1; 481 } 482 elf_plt_init((void *)PLTGOT(lmp), (caddr_t)lmp); 483 } 484 485 /* 486 * Initialize the plt start and end addresses. 487 */ 488 if ((pltbgn = (ulong_t)JMPREL(lmp)) != 0) 489 pltend = pltbgn + (ulong_t)(PLTRELSZ(lmp)); 490 491 492 relsiz = (ulong_t)(RELENT(lmp)); 493 basebgn = ADDR(lmp); 494 emap = ADDR(lmp) + MSIZE(lmp); 495 496 if (PLTRELSZ(lmp)) 497 plthint = PLTRELSZ(lmp) / relsiz; 498 499 /* 500 * If we've been called upon to promote an RTLD_LAZY object to an 501 * RTLD_NOW then we're only interested in scaning the .plt table. 502 * An uninitialized .plt is the case where the associated got entry 503 * points back to the plt itself. Determine the range of the real .plt 504 * entries using the _PROCEDURE_LINKAGE_TABLE_ symbol. 505 */ 506 if (plt) { 507 Slookup sl; 508 509 relbgn = pltbgn; 510 relend = pltend; 511 if (!relbgn || (relbgn == relend)) 512 return (1); 513 514 sl.sl_name = MSG_ORIG(MSG_SYM_PLT); 515 sl.sl_cmap = lmp; 516 sl.sl_imap = lmp; 517 sl.sl_hash = elf_hash(MSG_ORIG(MSG_SYM_PLT)); 518 sl.sl_rsymndx = 0; 519 sl.sl_flags = LKUP_DEFT; 520 521 if ((symdef = elf_find_sym(&sl, &_lmp, &binfo)) == 0) 522 return (1); 523 524 _pltbgn = symdef->st_value; 525 if (!(FLAGS(lmp) & FLG_RT_FIXED) && 526 (symdef->st_shndx != SHN_ABS)) 527 _pltbgn += basebgn; 528 _pltend = _pltbgn + (((PLTRELSZ(lmp) / relsiz)) * 529 M_PLT_ENTSIZE) + M_PLT_RESERVSZ; 530 531 } else { 532 /* 533 * The relocation sections appear to the run-time linker as a 534 * single table. Determine the address of the beginning and end 535 * of this table. There are two different interpretations of 536 * the ABI at this point: 537 * 538 * o The REL table and its associated RELSZ indicate the 539 * concatenation of *all* relocation sections (this is the 540 * model our link-editor constructs). 541 * 542 * o The REL table and its associated RELSZ indicate the 543 * concatenation of all *but* the .plt relocations. These 544 * relocations are specified individually by the JMPREL and 545 * PLTRELSZ entries. 546 * 547 * Determine from our knowledege of the relocation range and 548 * .plt range, the range of the total relocation table. Note 549 * that one other ABI assumption seems to be that the .plt 550 * relocations always follow any other relocations, the 551 * following range checking drops that assumption. 552 */ 553 relbgn = (ulong_t)(REL(lmp)); 554 relend = relbgn + (ulong_t)(RELSZ(lmp)); 555 if (pltbgn) { 556 if (!relbgn || (relbgn > pltbgn)) 557 relbgn = pltbgn; 558 if (!relbgn || (relend < pltend)) 559 relend = pltend; 560 } 561 } 562 if (!relbgn || (relbgn == relend)) { 563 DBG_CALL(Dbg_reloc_run(lmp, 0, plt, DBG_REL_NONE)); 564 return (1); 565 } 566 DBG_CALL(Dbg_reloc_run(lmp, M_REL_SHT_TYPE, plt, DBG_REL_START)); 567 568 /* 569 * If we're processing a dynamic executable in lazy mode there is no 570 * need to scan the .rel.plt table, however if we're processing a shared 571 * object in lazy mode the .got addresses associated to each .plt must 572 * be relocated to reflect the location of the shared object. 573 */ 574 if (pltbgn && ((MODE(lmp) & RTLD_NOW) == 0) && 575 (FLAGS(lmp) & FLG_RT_FIXED)) 576 noplt = 1; 577 578 /* 579 * Loop through relocations. 580 */ 581 while (relbgn < relend) { 582 uint_t sb_flags = 0; 583 584 rtype = ELF_R_TYPE(((Rela *)relbgn)->r_info); 585 586 /* 587 * If this is a RELATIVE relocation in a shared object (the 588 * common case), and if we are not debugging, then jump into a 589 * tighter relocation loop (elf_reloc_relative). Only make the 590 * jump if we've been given a hint on the number of relocations. 591 */ 592 if ((rtype == R_AMD64_RELATIVE) && 593 ((FLAGS(lmp) & FLG_RT_FIXED) == 0) && (DBG_ENABLED == 0)) { 594 /* 595 * It's possible that the relative relocation block 596 * has relocations against the text segment as well 597 * as the data segment. Since our optimized relocation 598 * engine does not check which segment the relocation 599 * is against - just mprotect it now if it's been 600 * marked as containing TEXTREL's. 601 */ 602 if ((textrel == 0) && (FLAGS1(lmp) & FL1_RT_TEXTREL)) { 603 if (elf_set_prot(lmp, PROT_WRITE) == 0) { 604 ret = 0; 605 break; 606 } 607 textrel = 1; 608 } 609 if (relacount) { 610 relbgn = elf_reloc_relacount(relbgn, relacount, 611 relsiz, basebgn); 612 relacount = 0; 613 } else { 614 relbgn = elf_reloc_relative(relbgn, relend, 615 relsiz, basebgn, etext, emap); 616 } 617 618 if (relbgn >= relend) 619 break; 620 rtype = ELF_R_TYPE(((Rela *)relbgn)->r_info); 621 } 622 623 roffset = ((Rela *)relbgn)->r_offset; 624 625 /* 626 * If this is a shared object, add the base address to offset. 627 */ 628 if (!(FLAGS(lmp) & FLG_RT_FIXED)) { 629 630 631 /* 632 * If we're processing lazy bindings, we have to step 633 * through the plt entries and add the base address 634 * to the corresponding got entry. 635 */ 636 if (plthint && (plt == 0) && 637 (rtype == R_AMD64_JUMP_SLOT) && 638 ((MODE(lmp) & RTLD_NOW) == 0)) { 639 /* 640 * The PLT relocations (for lazy bindings) 641 * are additive to what's already in the GOT. 642 * This differs to what happens in 643 * elf_reloc_relacount() and that's why we 644 * just do it inline here. 645 */ 646 for (roffset = ((Rela *)relbgn)->r_offset; 647 plthint; plthint--) { 648 roffset += basebgn; 649 650 /* 651 * Perform the actual relocation. 652 */ 653 *((ulong_t *)roffset) += basebgn; 654 655 relbgn += relsiz; 656 roffset = ((Rela *)relbgn)->r_offset; 657 658 } 659 continue; 660 } 661 roffset += basebgn; 662 } 663 664 reladd = (long)(((Rela *)relbgn)->r_addend); 665 rsymndx = ELF_R_SYM(((Rela *)relbgn)->r_info); 666 rel = (Rela *)relbgn; 667 relbgn += relsiz; 668 669 /* 670 * Optimizations. 671 */ 672 if (rtype == R_AMD64_NONE) 673 continue; 674 if (noplt && ((ulong_t)rel >= pltbgn) && 675 ((ulong_t)rel < pltend)) { 676 relbgn = pltend; 677 continue; 678 } 679 680 /* 681 * If this relocation is not against part of the image 682 * mapped into memory we skip it. 683 */ 684 if ((roffset < ADDR(lmp)) || (roffset > (ADDR(lmp) + 685 MSIZE(lmp)))) { 686 elf_reloc_bad(lmp, (void *)rel, rtype, roffset, 687 rsymndx); 688 continue; 689 } 690 691 /* 692 * If we're promoting plts determine if this one has already 693 * been written. 694 */ 695 if (plt) { 696 if ((*(ulong_t *)roffset < _pltbgn) || 697 (*(ulong_t *)roffset > _pltend)) 698 continue; 699 } 700 701 binfo = 0; 702 /* 703 * If a symbol index is specified then get the symbol table 704 * entry, locate the symbol definition, and determine its 705 * address. 706 */ 707 if (rsymndx) { 708 /* 709 * Get the local symbol table entry. 710 */ 711 symref = (Sym *)((ulong_t)SYMTAB(lmp) + 712 (rsymndx * SYMENT(lmp))); 713 714 /* 715 * If this is a local symbol, just use the base address. 716 * (we should have no local relocations in the 717 * executable). 718 */ 719 if (ELF_ST_BIND(symref->st_info) == STB_LOCAL) { 720 value = basebgn; 721 name = (char *)0; 722 723 /* 724 * Special case TLS relocations. 725 */ 726 if (rtype == R_AMD64_DTPMOD64) { 727 /* 728 * Use the TLS modid. 729 */ 730 value = TLSMODID(lmp); 731 732 } else if ((rtype == R_AMD64_TPOFF64) || 733 (rtype == R_AMD64_TPOFF32)) { 734 if ((value = elf_static_tls(lmp, symref, 735 rel, rtype, 0, roffset, 0)) == 0) { 736 ret = 0; 737 break; 738 } 739 } 740 } else { 741 /* 742 * If the symbol index is equal to the previous 743 * symbol index relocation we processed then 744 * reuse the previous values. (Note that there 745 * have been cases where a relocation exists 746 * against a copy relocation symbol, our ld(1) 747 * should optimize this away, but make sure we 748 * don't use the same symbol information should 749 * this case exist). 750 */ 751 if ((rsymndx == psymndx) && 752 (rtype != R_AMD64_COPY)) { 753 /* LINTED */ 754 if (psymdef == 0) { 755 DBG_CALL(Dbg_bind_weak(lmp, 756 (Addr)roffset, (Addr) 757 (roffset - basebgn), name)); 758 continue; 759 } 760 /* LINTED */ 761 value = pvalue; 762 /* LINTED */ 763 name = pname; 764 /* LINTED */ 765 symdef = psymdef; 766 /* LINTED */ 767 symref = psymref; 768 /* LINTED */ 769 _lmp = plmp; 770 /* LINTED */ 771 binfo = pbinfo; 772 773 if ((LIST(_lmp)->lm_tflags | 774 FLAGS1(_lmp)) & 775 LML_TFLG_AUD_SYMBIND) { 776 value = audit_symbind(lmp, _lmp, 777 /* LINTED */ 778 symdef, dsymndx, value, 779 &sb_flags); 780 } 781 } else { 782 Slookup sl; 783 uchar_t bind; 784 785 /* 786 * Lookup the symbol definition. 787 */ 788 name = (char *)(STRTAB(lmp) + 789 symref->st_name); 790 791 sl.sl_name = name; 792 sl.sl_cmap = lmp; 793 sl.sl_imap = 0; 794 sl.sl_hash = 0; 795 sl.sl_rsymndx = rsymndx; 796 797 if (rtype == R_AMD64_COPY) 798 sl.sl_flags = LKUP_COPY; 799 else 800 sl.sl_flags = LKUP_DEFT; 801 802 sl.sl_flags |= LKUP_ALLCNTLIST; 803 804 if (rtype != R_AMD64_JUMP_SLOT) 805 sl.sl_flags |= LKUP_SPEC; 806 807 bind = ELF_ST_BIND(symref->st_info); 808 if (bind == STB_WEAK) 809 sl.sl_flags |= LKUP_WEAK; 810 811 symdef = lookup_sym(&sl, &_lmp, &binfo); 812 813 /* 814 * If the symbol is not found and the 815 * reference was not to a weak symbol, 816 * report an error. Weak references 817 * may be unresolved. 818 * chkmsg: MSG_INTL(MSG_LDD_SYM_NFOUND) 819 */ 820 /* BEGIN CSTYLED */ 821 if (symdef == 0) { 822 Lm_list *lml = LIST(lmp); 823 824 if (bind != STB_WEAK) { 825 if (lml->lm_flags & 826 LML_FLG_IGNRELERR) { 827 continue; 828 } else if (lml->lm_flags & 829 LML_FLG_TRC_WARN) { 830 (void) printf(MSG_INTL( 831 MSG_LDD_SYM_NFOUND), 832 demangle(name), 833 NAME(lmp)); 834 continue; 835 } else { 836 DBG_CALL(Dbg_reloc_in(lml, 837 ELF_DBG_RTLD, M_MACH, 838 M_REL_SHT_TYPE, rel, 839 NULL, name)); 840 eprintf(lml, ERR_FATAL, 841 MSG_INTL(MSG_REL_NOSYM), 842 NAME(lmp), 843 demangle(name)); 844 ret = 0; 845 break; 846 } 847 } else { 848 psymndx = rsymndx; 849 psymdef = 0; 850 851 DBG_CALL(Dbg_bind_weak(lmp, 852 (Addr)roffset, (Addr) 853 (roffset - basebgn), name)); 854 continue; 855 } 856 } 857 /* END CSTYLED */ 858 859 /* 860 * If symbol was found in an object 861 * other than the referencing object 862 * then record the binding. 863 */ 864 if ((lmp != _lmp) && ((FLAGS1(_lmp) & 865 FL1_RT_NOINIFIN) == 0)) { 866 if (alist_test(&bound, _lmp, 867 sizeof (Rt_map *), 868 AL_CNT_RELBIND) == 0) { 869 ret = 0; 870 break; 871 } 872 } 873 874 /* 875 * Calculate the location of definition; 876 * symbol value plus base address of 877 * containing shared object. 878 */ 879 if (IS_SIZE(rtype)) 880 value = symdef->st_size; 881 else 882 value = symdef->st_value; 883 884 if (!(FLAGS(_lmp) & FLG_RT_FIXED) && 885 !(IS_SIZE(rtype)) && 886 (symdef->st_shndx != SHN_ABS) && 887 (ELF_ST_TYPE(symdef->st_info) != 888 STT_TLS)) 889 value += ADDR(_lmp); 890 891 /* 892 * Retain this symbol index and the 893 * value in case it can be used for the 894 * subsequent relocations. 895 */ 896 if (rtype != R_AMD64_COPY) { 897 psymndx = rsymndx; 898 pvalue = value; 899 pname = name; 900 psymdef = symdef; 901 psymref = symref; 902 plmp = _lmp; 903 pbinfo = binfo; 904 } 905 if ((LIST(_lmp)->lm_tflags | 906 FLAGS1(_lmp)) & 907 LML_TFLG_AUD_SYMBIND) { 908 dsymndx = (((uintptr_t)symdef - 909 (uintptr_t)SYMTAB(_lmp)) / 910 SYMENT(_lmp)); 911 value = audit_symbind(lmp, _lmp, 912 symdef, dsymndx, value, 913 &sb_flags); 914 } 915 } 916 917 /* 918 * If relocation is PC-relative, subtract 919 * offset address. 920 */ 921 if (IS_PC_RELATIVE(rtype)) 922 value -= roffset; 923 924 /* 925 * Special case TLS relocations. 926 */ 927 if (rtype == R_AMD64_DTPMOD64) { 928 /* 929 * Relocation value is the TLS modid. 930 */ 931 value = TLSMODID(_lmp); 932 933 } else if ((rtype == R_AMD64_TPOFF64) || 934 (rtype == R_AMD64_TPOFF32)) { 935 if ((value = elf_static_tls(_lmp, 936 symdef, rel, rtype, name, roffset, 937 value)) == 0) { 938 ret = 0; 939 break; 940 } 941 } 942 } 943 } else { 944 /* 945 * Special cases. 946 */ 947 if (rtype == R_AMD64_DTPMOD64) { 948 /* 949 * TLS relocation value is the TLS modid. 950 */ 951 value = TLSMODID(lmp); 952 } else 953 value = basebgn; 954 name = (char *)0; 955 } 956 957 DBG_CALL(Dbg_reloc_in(LIST(lmp), ELF_DBG_RTLD, M_MACH, 958 M_REL_SHT_TYPE, rel, NULL, name)); 959 960 /* 961 * If this object has relocations in the text segment, turn 962 * off the write protect. 963 */ 964 if ((roffset < etext) && (textrel == 0)) { 965 if (elf_set_prot(lmp, PROT_WRITE) == 0) { 966 ret = 0; 967 break; 968 } 969 textrel = 1; 970 } 971 972 /* 973 * Call relocation routine to perform required relocation. 974 */ 975 switch (rtype) { 976 case R_AMD64_COPY: 977 if (elf_copy_reloc(name, symref, lmp, (void *)roffset, 978 symdef, _lmp, (const void *)value) == 0) 979 ret = 0; 980 break; 981 case R_AMD64_JUMP_SLOT: 982 if (((LIST(lmp)->lm_tflags | FLAGS1(lmp)) & 983 (LML_TFLG_AUD_PLTENTER | LML_TFLG_AUD_PLTEXIT)) && 984 AUDINFO(lmp)->ai_dynplts) { 985 int fail = 0; 986 int pltndx = (((ulong_t)rel - 987 (uintptr_t)JMPREL(lmp)) / relsiz); 988 int symndx = (((uintptr_t)symdef - 989 (uintptr_t)SYMTAB(_lmp)) / SYMENT(_lmp)); 990 991 (void) elf_plt_trace_write(roffset, lmp, _lmp, 992 symdef, symndx, pltndx, (caddr_t)value, 993 sb_flags, &fail); 994 if (fail) 995 ret = 0; 996 } else { 997 /* 998 * Write standard PLT entry to jump directly 999 * to newly bound function. 1000 */ 1001 DBG_CALL(Dbg_reloc_apply_val(LIST(lmp), 1002 ELF_DBG_RTLD, (Xword)roffset, 1003 (Xword)value)); 1004 *(ulong_t *)roffset = value; 1005 } 1006 break; 1007 default: 1008 value += reladd; 1009 /* 1010 * Write the relocation out. 1011 */ 1012 if (do_reloc(rtype, (uchar_t *)roffset, 1013 (Xword *)&value, name, NAME(lmp), LIST(lmp)) == 0) 1014 ret = 0; 1015 1016 DBG_CALL(Dbg_reloc_apply_val(LIST(lmp), ELF_DBG_RTLD, 1017 (Xword)roffset, (Xword)value)); 1018 } 1019 1020 if ((ret == 0) && 1021 ((LIST(lmp)->lm_flags & LML_FLG_TRC_WARN) == 0)) 1022 break; 1023 1024 if (binfo) { 1025 DBG_CALL(Dbg_bind_global(lmp, (Addr)roffset, 1026 (Off)(roffset - basebgn), (Xword)(-1), PLT_T_FULL, 1027 _lmp, (Addr)value, symdef->st_value, name, binfo)); 1028 } 1029 } 1030 1031 return (relocate_finish(lmp, bound, textrel, ret)); 1032 } 1033 1034 /* 1035 * Initialize the first few got entries so that function calls go to 1036 * elf_rtbndr: 1037 * 1038 * GOT[GOT_XLINKMAP] = the address of the link map 1039 * GOT[GOT_XRTLD] = the address of rtbinder 1040 */ 1041 void 1042 elf_plt_init(void *got, caddr_t l) 1043 { 1044 uint64_t *_got; 1045 /* LINTED */ 1046 Rt_map *lmp = (Rt_map *)l; 1047 1048 _got = (uint64_t *)got + M_GOT_XLINKMAP; 1049 *_got = (uint64_t)lmp; 1050 _got = (uint64_t *)got + M_GOT_XRTLD; 1051 *_got = (uint64_t)elf_rtbndr; 1052 } 1053 1054 /* 1055 * Plt writing interface to allow debugging initialization to be generic. 1056 */ 1057 Pltbindtype 1058 /* ARGSUSED1 */ 1059 elf_plt_write(uintptr_t addr, uintptr_t vaddr, void *rptr, uintptr_t symval, 1060 Xword pltndx) 1061 { 1062 Rela *rel = (Rela*)rptr; 1063 uintptr_t pltaddr; 1064 1065 pltaddr = addr + rel->r_offset; 1066 *(ulong_t *)pltaddr = (ulong_t)symval + rel->r_addend; 1067 DBG_CALL(pltcntfull++); 1068 return (PLT_T_FULL); 1069 } 1070 1071 /* 1072 * Provide a machine specific interface to the conversion routine. By calling 1073 * the machine specific version, rather than the generic version, we insure that 1074 * the data tables/strings for all known machine versions aren't dragged into 1075 * ld.so.1. 1076 */ 1077 const char * 1078 _conv_reloc_type(uint_t rel) 1079 { 1080 return (conv_reloc_amd64_type(rel, 0)); 1081 } 1082