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 2008 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27 #pragma ident "%Z%%M% %I% %E% SMI" 28 29 /* 30 * amd64 machine dependent and ELF file class dependent functions. 31 * Contains routines for performing function binding and symbol relocations. 32 */ 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_rtld(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_rtld(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 *rsym, *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(0); 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 Conv_inv_buf_t inv_buf; 249 250 eprintf(lml, ERR_FATAL, MSG_INTL(MSG_REL_PLTREF), 251 conv_reloc_amd64_type(R_AMD64_JUMP_SLOT, 0, &inv_buf), 252 EC_NATPTR(lmp), EC_XWORD(pltndx), EC_NATPTR(from)); 253 rtldexit(lml, 1); 254 } 255 reloff = pltndx * (ulong_t)RELENT(lmp); 256 257 /* 258 * Use relocation entry to get symbol table entry and symbol name. 259 */ 260 addr = (ulong_t)JMPREL(lmp); 261 rptr = (Rela *)(addr + reloff); 262 rsymndx = ELF_R_SYM(rptr->r_info); 263 rsym = (Sym *)((ulong_t)SYMTAB(lmp) + (rsymndx * SYMENT(lmp))); 264 name = (char *)(STRTAB(lmp) + rsym->st_name); 265 266 /* 267 * Determine the last link-map of this list, this'll be the starting 268 * point for any tsort() processing. 269 */ 270 llmp = lml->lm_tail; 271 272 /* 273 * Find definition for symbol. Initialize the symbol lookup data 274 * structure. 275 */ 276 SLOOKUP_INIT(sl, name, lmp, lml->lm_head, ld_entry_cnt, 0, 277 rsymndx, rsym, 0, LKUP_DEFT); 278 279 if ((nsym = lookup_sym(&sl, &nlmp, &binfo, NULL)) == 0) { 280 eprintf(lml, ERR_FATAL, MSG_INTL(MSG_REL_NOSYM), NAME(lmp), 281 demangle(name)); 282 rtldexit(lml, 1); 283 } 284 285 symval = nsym->st_value; 286 if (!(FLAGS(nlmp) & FLG_RT_FIXED) && 287 (nsym->st_shndx != SHN_ABS)) 288 symval += ADDR(nlmp); 289 if ((lmp != nlmp) && ((FLAGS1(nlmp) & FL1_RT_NOINIFIN) == 0)) { 290 /* 291 * Record that this new link map is now bound to the caller. 292 */ 293 if (bind_one(lmp, nlmp, BND_REFER) == 0) 294 rtldexit(lml, 1); 295 } 296 297 if ((lml->lm_tflags | FLAGS1(lmp)) & LML_TFLG_AUD_SYMBIND) { 298 uint_t symndx = (((uintptr_t)nsym - 299 (uintptr_t)SYMTAB(nlmp)) / SYMENT(nlmp)); 300 symval = audit_symbind(lmp, nlmp, nsym, symndx, symval, 301 &sb_flags); 302 } 303 304 if (!(rtld_flags & RT_FL_NOBIND)) { 305 addr = rptr->r_offset; 306 if (!(FLAGS(lmp) & FLG_RT_FIXED)) 307 addr += ADDR(lmp); 308 if (((lml->lm_tflags | FLAGS1(lmp)) & 309 (LML_TFLG_AUD_PLTENTER | LML_TFLG_AUD_PLTEXIT)) && 310 AUDINFO(lmp)->ai_dynplts) { 311 int fail = 0; 312 uint_t pltndx = reloff / sizeof (Rela); 313 uint_t symndx = (((uintptr_t)nsym - 314 (uintptr_t)SYMTAB(nlmp)) / SYMENT(nlmp)); 315 316 symval = (ulong_t)elf_plt_trace_write(addr, lmp, nlmp, 317 nsym, symndx, pltndx, (caddr_t)symval, sb_flags, 318 &fail); 319 if (fail) 320 rtldexit(lml, 1); 321 } else { 322 /* 323 * Write standard PLT entry to jump directly 324 * to newly bound function. 325 */ 326 *(ulong_t *)addr = symval; 327 } 328 } 329 330 /* 331 * Print binding information and rebuild PLT entry. 332 */ 333 DBG_CALL(Dbg_bind_global(lmp, (Addr)from, (Off)(from - ADDR(lmp)), 334 (Xword)(reloff / sizeof (Rela)), PLT_T_FULL, nlmp, 335 (Addr)symval, nsym->st_value, name, binfo)); 336 337 /* 338 * Complete any processing for newly loaded objects. Note we don't 339 * know exactly where any new objects are loaded (we know the object 340 * that supplied the symbol, but others may have been loaded lazily as 341 * we searched for the symbol), so sorting starts from the last 342 * link-map know on entry to this routine. 343 */ 344 if (entry) 345 load_completion(llmp); 346 347 /* 348 * Some operations like dldump() or dlopen()'ing a relocatable object 349 * result in objects being loaded on rtld's link-map, make sure these 350 * objects are initialized also. 351 */ 352 if ((lml->lm_flags & LML_FLG_RTLDLM) && LIST(nlmp)->lm_init) 353 load_completion(nlmp); 354 355 /* 356 * If the object we've bound to is in the process of being initialized 357 * by another thread, determine whether we should block. 358 */ 359 is_dep_ready(nlmp, lmp, DBG_WAIT_SYMBOL); 360 361 /* 362 * Make sure the object to which we've bound has had it's .init fired. 363 * Cleanup before return to user code. 364 */ 365 if (entry) { 366 is_dep_init(nlmp, lmp); 367 leave(lml, 0); 368 } 369 370 if (lmflags & LML_FLG_RTLDLM) 371 dbg_desc->d_class = dbg_class; 372 373 return (symval); 374 } 375 376 377 /* 378 * When the relocation loop realizes that it's dealing with relative 379 * relocations in a shared object, it breaks into this tighter loop 380 * as an optimization. 381 */ 382 ulong_t 383 elf_reloc_relative(ulong_t relbgn, ulong_t relend, ulong_t relsiz, 384 ulong_t basebgn, ulong_t etext, ulong_t emap) 385 { 386 ulong_t roffset = ((Rela *)relbgn)->r_offset; 387 char rtype; 388 389 do { 390 roffset += basebgn; 391 392 /* 393 * If this relocation is against an address not mapped in, 394 * then break out of the relative relocation loop, falling 395 * back on the main relocation loop. 396 */ 397 if (roffset < etext || roffset > emap) 398 break; 399 400 /* 401 * Perform the actual relocation. 402 */ 403 *((ulong_t *)roffset) = basebgn + 404 ((Rela *)relbgn)->r_addend; 405 406 relbgn += relsiz; 407 408 if (relbgn >= relend) 409 break; 410 411 rtype = ELF_R_TYPE(((Rela *)relbgn)->r_info, M_MACH); 412 roffset = ((Rela *)relbgn)->r_offset; 413 414 } while (rtype == R_AMD64_RELATIVE); 415 416 return (relbgn); 417 } 418 419 /* 420 * This is the tightest loop for RELATIVE relocations for those 421 * objects built with the DT_RELACOUNT .dynamic entry. 422 */ 423 ulong_t 424 elf_reloc_relacount(ulong_t relbgn, ulong_t relacount, ulong_t relsiz, 425 ulong_t basebgn) 426 { 427 ulong_t roffset = ((Rela *) relbgn)->r_offset; 428 429 for (; relacount; relacount--) { 430 roffset += basebgn; 431 432 /* 433 * Perform the actual relocation. 434 */ 435 *((ulong_t *)roffset) = basebgn + 436 ((Rela *)relbgn)->r_addend; 437 438 relbgn += relsiz; 439 440 roffset = ((Rela *)relbgn)->r_offset; 441 442 } 443 444 return (relbgn); 445 } 446 447 /* 448 * Read and process the relocations for one link object, we assume all 449 * relocation sections for loadable segments are stored contiguously in 450 * the file. 451 */ 452 int 453 elf_reloc(Rt_map *lmp, uint_t plt, int *in_nfavl) 454 { 455 ulong_t relbgn, relend, relsiz, basebgn; 456 ulong_t pltbgn, pltend, _pltbgn, _pltend; 457 ulong_t roffset, rsymndx, psymndx = 0, etext = ETEXT(lmp); 458 ulong_t emap, dsymndx; 459 uchar_t rtype; 460 long reladd, value, pvalue; 461 Sym *symref, *psymref, *symdef, *psymdef; 462 char *name, *pname; 463 Rt_map *_lmp, *plmp; 464 int textrel = 0, ret = 1, noplt = 0; 465 int relacount = RELACOUNT(lmp), plthint = 0; 466 Rela *rel; 467 uint_t binfo, pbinfo; 468 APlist *bound = NULL; 469 470 /* 471 * Although only necessary for lazy binding, initialize the first 472 * global offset entry to go to elf_rtbndr(). dbx(1) seems 473 * to find this useful. 474 */ 475 if ((plt == 0) && PLTGOT(lmp)) { 476 if ((ulong_t)PLTGOT(lmp) < etext) { 477 if (elf_set_prot(lmp, PROT_WRITE) == 0) 478 return (0); 479 textrel = 1; 480 } 481 elf_plt_init((void *)PLTGOT(lmp), (caddr_t)lmp); 482 } 483 484 /* 485 * Initialize the plt start and end addresses. 486 */ 487 if ((pltbgn = (ulong_t)JMPREL(lmp)) != 0) 488 pltend = pltbgn + (ulong_t)(PLTRELSZ(lmp)); 489 490 491 relsiz = (ulong_t)(RELENT(lmp)); 492 basebgn = ADDR(lmp); 493 emap = ADDR(lmp) + MSIZE(lmp); 494 495 if (PLTRELSZ(lmp)) 496 plthint = PLTRELSZ(lmp) / relsiz; 497 498 /* 499 * If we've been called upon to promote an RTLD_LAZY object to an 500 * RTLD_NOW then we're only interested in scaning the .plt table. 501 * An uninitialized .plt is the case where the associated got entry 502 * points back to the plt itself. Determine the range of the real .plt 503 * entries using the _PROCEDURE_LINKAGE_TABLE_ symbol. 504 */ 505 if (plt) { 506 Slookup sl; 507 508 relbgn = pltbgn; 509 relend = pltend; 510 if (!relbgn || (relbgn == relend)) 511 return (1); 512 513 /* 514 * Initialize the symbol lookup data structure. 515 */ 516 SLOOKUP_INIT(sl, MSG_ORIG(MSG_SYM_PLT), lmp, lmp, ld_entry_cnt, 517 elf_hash(MSG_ORIG(MSG_SYM_PLT)), 0, 0, 0, LKUP_DEFT); 518 519 if ((symdef = elf_find_sym(&sl, &_lmp, 520 &binfo, in_nfavl)) == 0) 521 return (1); 522 523 _pltbgn = symdef->st_value; 524 if (!(FLAGS(lmp) & FLG_RT_FIXED) && 525 (symdef->st_shndx != SHN_ABS)) 526 _pltbgn += basebgn; 527 _pltend = _pltbgn + (((PLTRELSZ(lmp) / relsiz)) * 528 M_PLT_ENTSIZE) + M_PLT_RESERVSZ; 529 530 } else { 531 /* 532 * The relocation sections appear to the run-time linker as a 533 * single table. Determine the address of the beginning and end 534 * of this table. There are two different interpretations of 535 * the ABI at this point: 536 * 537 * o The REL table and its associated RELSZ indicate the 538 * concatenation of *all* relocation sections (this is the 539 * model our link-editor constructs). 540 * 541 * o The REL table and its associated RELSZ indicate the 542 * concatenation of all *but* the .plt relocations. These 543 * relocations are specified individually by the JMPREL and 544 * PLTRELSZ entries. 545 * 546 * Determine from our knowledege of the relocation range and 547 * .plt range, the range of the total relocation table. Note 548 * that one other ABI assumption seems to be that the .plt 549 * relocations always follow any other relocations, the 550 * following range checking drops that assumption. 551 */ 552 relbgn = (ulong_t)(REL(lmp)); 553 relend = relbgn + (ulong_t)(RELSZ(lmp)); 554 if (pltbgn) { 555 if (!relbgn || (relbgn > pltbgn)) 556 relbgn = pltbgn; 557 if (!relbgn || (relend < pltend)) 558 relend = pltend; 559 } 560 } 561 if (!relbgn || (relbgn == relend)) { 562 DBG_CALL(Dbg_reloc_run(lmp, 0, plt, DBG_REL_NONE)); 563 return (1); 564 } 565 DBG_CALL(Dbg_reloc_run(lmp, M_REL_SHT_TYPE, plt, DBG_REL_START)); 566 567 /* 568 * If we're processing a dynamic executable in lazy mode there is no 569 * need to scan the .rel.plt table, however if we're processing a shared 570 * object in lazy mode the .got addresses associated to each .plt must 571 * be relocated to reflect the location of the shared object. 572 */ 573 if (pltbgn && ((MODE(lmp) & RTLD_NOW) == 0) && 574 (FLAGS(lmp) & FLG_RT_FIXED)) 575 noplt = 1; 576 577 /* 578 * Loop through relocations. 579 */ 580 while (relbgn < relend) { 581 uint_t sb_flags = 0; 582 583 rtype = ELF_R_TYPE(((Rela *)relbgn)->r_info, M_MACH); 584 585 /* 586 * If this is a RELATIVE relocation in a shared object (the 587 * common case), and if we are not debugging, then jump into a 588 * tighter relocation loop (elf_reloc_relative). Only make the 589 * jump if we've been given a hint on the number of relocations. 590 */ 591 if ((rtype == R_AMD64_RELATIVE) && 592 ((FLAGS(lmp) & FLG_RT_FIXED) == 0) && (DBG_ENABLED == 0)) { 593 /* 594 * It's possible that the relative relocation block 595 * has relocations against the text segment as well 596 * as the data segment. Since our optimized relocation 597 * engine does not check which segment the relocation 598 * is against - just mprotect it now if it's been 599 * marked as containing TEXTREL's. 600 */ 601 if ((textrel == 0) && (FLAGS1(lmp) & FL1_RT_TEXTREL)) { 602 if (elf_set_prot(lmp, PROT_WRITE) == 0) { 603 ret = 0; 604 break; 605 } 606 textrel = 1; 607 } 608 if (relacount) { 609 relbgn = elf_reloc_relacount(relbgn, relacount, 610 relsiz, basebgn); 611 relacount = 0; 612 } else { 613 relbgn = elf_reloc_relative(relbgn, relend, 614 relsiz, basebgn, etext, emap); 615 } 616 617 if (relbgn >= relend) 618 break; 619 rtype = ELF_R_TYPE(((Rela *)relbgn)->r_info, M_MACH); 620 } 621 622 roffset = ((Rela *)relbgn)->r_offset; 623 624 /* 625 * If this is a shared object, add the base address to offset. 626 */ 627 if (!(FLAGS(lmp) & FLG_RT_FIXED)) { 628 629 630 /* 631 * If we're processing lazy bindings, we have to step 632 * through the plt entries and add the base address 633 * to the corresponding got entry. 634 */ 635 if (plthint && (plt == 0) && 636 (rtype == R_AMD64_JUMP_SLOT) && 637 ((MODE(lmp) & RTLD_NOW) == 0)) { 638 /* 639 * The PLT relocations (for lazy bindings) 640 * are additive to what's already in the GOT. 641 * This differs to what happens in 642 * elf_reloc_relacount() and that's why we 643 * just do it inline here. 644 */ 645 for (roffset = ((Rela *)relbgn)->r_offset; 646 plthint; plthint--) { 647 roffset += basebgn; 648 649 /* 650 * Perform the actual relocation. 651 */ 652 *((ulong_t *)roffset) += basebgn; 653 654 relbgn += relsiz; 655 roffset = ((Rela *)relbgn)->r_offset; 656 657 } 658 continue; 659 } 660 roffset += basebgn; 661 } 662 663 reladd = (long)(((Rela *)relbgn)->r_addend); 664 rsymndx = ELF_R_SYM(((Rela *)relbgn)->r_info); 665 rel = (Rela *)relbgn; 666 relbgn += relsiz; 667 668 /* 669 * Optimizations. 670 */ 671 if (rtype == R_AMD64_NONE) 672 continue; 673 if (noplt && ((ulong_t)rel >= pltbgn) && 674 ((ulong_t)rel < pltend)) { 675 relbgn = pltend; 676 continue; 677 } 678 679 /* 680 * If this relocation is not against part of the image 681 * mapped into memory we skip it. 682 */ 683 if ((roffset < ADDR(lmp)) || (roffset > (ADDR(lmp) + 684 MSIZE(lmp)))) { 685 elf_reloc_bad(lmp, (void *)rel, rtype, roffset, 686 rsymndx); 687 continue; 688 } 689 690 /* 691 * If we're promoting plts determine if this one has already 692 * been written. 693 */ 694 if (plt) { 695 if ((*(ulong_t *)roffset < _pltbgn) || 696 (*(ulong_t *)roffset > _pltend)) 697 continue; 698 } 699 700 binfo = 0; 701 /* 702 * If a symbol index is specified then get the symbol table 703 * entry, locate the symbol definition, and determine its 704 * address. 705 */ 706 if (rsymndx) { 707 /* 708 * Get the local symbol table entry. 709 */ 710 symref = (Sym *)((ulong_t)SYMTAB(lmp) + 711 (rsymndx * SYMENT(lmp))); 712 713 /* 714 * If this is a local symbol, just use the base address. 715 * (we should have no local relocations in the 716 * executable). 717 */ 718 if (ELF_ST_BIND(symref->st_info) == STB_LOCAL) { 719 value = basebgn; 720 name = (char *)0; 721 722 /* 723 * Special case TLS relocations. 724 */ 725 if (rtype == R_AMD64_DTPMOD64) { 726 /* 727 * Use the TLS modid. 728 */ 729 value = TLSMODID(lmp); 730 731 } else if ((rtype == R_AMD64_TPOFF64) || 732 (rtype == R_AMD64_TPOFF32)) { 733 if ((value = elf_static_tls(lmp, symref, 734 rel, rtype, 0, roffset, 0)) == 0) { 735 ret = 0; 736 break; 737 } 738 } 739 } else { 740 /* 741 * If the symbol index is equal to the previous 742 * symbol index relocation we processed then 743 * reuse the previous values. (Note that there 744 * have been cases where a relocation exists 745 * against a copy relocation symbol, our ld(1) 746 * should optimize this away, but make sure we 747 * don't use the same symbol information should 748 * this case exist). 749 */ 750 if ((rsymndx == psymndx) && 751 (rtype != R_AMD64_COPY)) { 752 /* LINTED */ 753 if (psymdef == 0) { 754 DBG_CALL(Dbg_bind_weak(lmp, 755 (Addr)roffset, (Addr) 756 (roffset - basebgn), name)); 757 continue; 758 } 759 /* LINTED */ 760 value = pvalue; 761 /* LINTED */ 762 name = pname; 763 /* LINTED */ 764 symdef = psymdef; 765 /* LINTED */ 766 symref = psymref; 767 /* LINTED */ 768 _lmp = plmp; 769 /* LINTED */ 770 binfo = pbinfo; 771 772 if ((LIST(_lmp)->lm_tflags | 773 FLAGS1(_lmp)) & 774 LML_TFLG_AUD_SYMBIND) { 775 value = audit_symbind(lmp, _lmp, 776 /* LINTED */ 777 symdef, dsymndx, value, 778 &sb_flags); 779 } 780 } else { 781 Slookup sl; 782 783 /* 784 * Lookup the symbol definition. 785 * Initialize the symbol lookup data 786 * structure. 787 */ 788 name = (char *)(STRTAB(lmp) + 789 symref->st_name); 790 791 SLOOKUP_INIT(sl, name, lmp, 0, 792 ld_entry_cnt, 0, rsymndx, symref, 793 rtype, LKUP_STDRELOC); 794 795 symdef = lookup_sym(&sl, &_lmp, 796 &binfo, in_nfavl); 797 798 /* 799 * If the symbol is not found and the 800 * reference was not to a weak symbol, 801 * report an error. Weak references 802 * may be unresolved. 803 */ 804 /* BEGIN CSTYLED */ 805 if (symdef == 0) { 806 if (sl.sl_bind != STB_WEAK) { 807 if (elf_reloc_error(lmp, name, 808 rel, binfo)) 809 continue; 810 811 ret = 0; 812 break; 813 814 } else { 815 psymndx = rsymndx; 816 psymdef = 0; 817 818 DBG_CALL(Dbg_bind_weak(lmp, 819 (Addr)roffset, (Addr) 820 (roffset - basebgn), name)); 821 continue; 822 } 823 } 824 /* END CSTYLED */ 825 826 /* 827 * If symbol was found in an object 828 * other than the referencing object 829 * then record the binding. 830 */ 831 if ((lmp != _lmp) && ((FLAGS1(_lmp) & 832 FL1_RT_NOINIFIN) == 0)) { 833 if (aplist_test(&bound, _lmp, 834 AL_CNT_RELBIND) == 0) { 835 ret = 0; 836 break; 837 } 838 } 839 840 /* 841 * Calculate the location of definition; 842 * symbol value plus base address of 843 * containing shared object. 844 */ 845 if (IS_SIZE(rtype)) 846 value = symdef->st_size; 847 else 848 value = symdef->st_value; 849 850 if (!(FLAGS(_lmp) & FLG_RT_FIXED) && 851 !(IS_SIZE(rtype)) && 852 (symdef->st_shndx != SHN_ABS) && 853 (ELF_ST_TYPE(symdef->st_info) != 854 STT_TLS)) 855 value += ADDR(_lmp); 856 857 /* 858 * Retain this symbol index and the 859 * value in case it can be used for the 860 * subsequent relocations. 861 */ 862 if (rtype != R_AMD64_COPY) { 863 psymndx = rsymndx; 864 pvalue = value; 865 pname = name; 866 psymdef = symdef; 867 psymref = symref; 868 plmp = _lmp; 869 pbinfo = binfo; 870 } 871 if ((LIST(_lmp)->lm_tflags | 872 FLAGS1(_lmp)) & 873 LML_TFLG_AUD_SYMBIND) { 874 dsymndx = (((uintptr_t)symdef - 875 (uintptr_t)SYMTAB(_lmp)) / 876 SYMENT(_lmp)); 877 value = audit_symbind(lmp, _lmp, 878 symdef, dsymndx, value, 879 &sb_flags); 880 } 881 } 882 883 /* 884 * If relocation is PC-relative, subtract 885 * offset address. 886 */ 887 if (IS_PC_RELATIVE(rtype)) 888 value -= roffset; 889 890 /* 891 * Special case TLS relocations. 892 */ 893 if (rtype == R_AMD64_DTPMOD64) { 894 /* 895 * Relocation value is the TLS modid. 896 */ 897 value = TLSMODID(_lmp); 898 899 } else if ((rtype == R_AMD64_TPOFF64) || 900 (rtype == R_AMD64_TPOFF32)) { 901 if ((value = elf_static_tls(_lmp, 902 symdef, rel, rtype, name, roffset, 903 value)) == 0) { 904 ret = 0; 905 break; 906 } 907 } 908 } 909 } else { 910 /* 911 * Special cases. 912 */ 913 if (rtype == R_AMD64_DTPMOD64) { 914 /* 915 * TLS relocation value is the TLS modid. 916 */ 917 value = TLSMODID(lmp); 918 } else 919 value = basebgn; 920 name = (char *)0; 921 } 922 923 DBG_CALL(Dbg_reloc_in(LIST(lmp), ELF_DBG_RTLD, M_MACH, 924 M_REL_SHT_TYPE, rel, NULL, name)); 925 926 /* 927 * If this object has relocations in the text segment, turn 928 * off the write protect. 929 */ 930 if ((roffset < etext) && (textrel == 0)) { 931 if (elf_set_prot(lmp, PROT_WRITE) == 0) { 932 ret = 0; 933 break; 934 } 935 textrel = 1; 936 } 937 938 /* 939 * Call relocation routine to perform required relocation. 940 */ 941 switch (rtype) { 942 case R_AMD64_COPY: 943 if (elf_copy_reloc(name, symref, lmp, (void *)roffset, 944 symdef, _lmp, (const void *)value) == 0) 945 ret = 0; 946 break; 947 case R_AMD64_JUMP_SLOT: 948 if (((LIST(lmp)->lm_tflags | FLAGS1(lmp)) & 949 (LML_TFLG_AUD_PLTENTER | LML_TFLG_AUD_PLTEXIT)) && 950 AUDINFO(lmp)->ai_dynplts) { 951 int fail = 0; 952 int pltndx = (((ulong_t)rel - 953 (uintptr_t)JMPREL(lmp)) / relsiz); 954 int symndx = (((uintptr_t)symdef - 955 (uintptr_t)SYMTAB(_lmp)) / SYMENT(_lmp)); 956 957 (void) elf_plt_trace_write(roffset, lmp, _lmp, 958 symdef, symndx, pltndx, (caddr_t)value, 959 sb_flags, &fail); 960 if (fail) 961 ret = 0; 962 } else { 963 /* 964 * Write standard PLT entry to jump directly 965 * to newly bound function. 966 */ 967 DBG_CALL(Dbg_reloc_apply_val(LIST(lmp), 968 ELF_DBG_RTLD, (Xword)roffset, 969 (Xword)value)); 970 *(ulong_t *)roffset = value; 971 } 972 break; 973 default: 974 value += reladd; 975 /* 976 * Write the relocation out. 977 */ 978 if (do_reloc_rtld(rtype, (uchar_t *)roffset, 979 (Xword *)&value, name, NAME(lmp), LIST(lmp)) == 0) 980 ret = 0; 981 982 DBG_CALL(Dbg_reloc_apply_val(LIST(lmp), ELF_DBG_RTLD, 983 (Xword)roffset, (Xword)value)); 984 } 985 986 if ((ret == 0) && 987 ((LIST(lmp)->lm_flags & LML_FLG_TRC_WARN) == 0)) 988 break; 989 990 if (binfo) { 991 DBG_CALL(Dbg_bind_global(lmp, (Addr)roffset, 992 (Off)(roffset - basebgn), (Xword)(-1), PLT_T_FULL, 993 _lmp, (Addr)value, symdef->st_value, name, binfo)); 994 } 995 } 996 997 return (relocate_finish(lmp, bound, textrel, ret)); 998 } 999 1000 /* 1001 * Initialize the first few got entries so that function calls go to 1002 * elf_rtbndr: 1003 * 1004 * GOT[GOT_XLINKMAP] = the address of the link map 1005 * GOT[GOT_XRTLD] = the address of rtbinder 1006 */ 1007 void 1008 elf_plt_init(void *got, caddr_t l) 1009 { 1010 uint64_t *_got; 1011 /* LINTED */ 1012 Rt_map *lmp = (Rt_map *)l; 1013 1014 _got = (uint64_t *)got + M_GOT_XLINKMAP; 1015 *_got = (uint64_t)lmp; 1016 _got = (uint64_t *)got + M_GOT_XRTLD; 1017 *_got = (uint64_t)elf_rtbndr; 1018 } 1019 1020 /* 1021 * Plt writing interface to allow debugging initialization to be generic. 1022 */ 1023 Pltbindtype 1024 /* ARGSUSED1 */ 1025 elf_plt_write(uintptr_t addr, uintptr_t vaddr, void *rptr, uintptr_t symval, 1026 Xword pltndx) 1027 { 1028 Rela *rel = (Rela*)rptr; 1029 uintptr_t pltaddr; 1030 1031 pltaddr = addr + rel->r_offset; 1032 *(ulong_t *)pltaddr = (ulong_t)symval + rel->r_addend; 1033 DBG_CALL(pltcntfull++); 1034 return (PLT_T_FULL); 1035 } 1036 1037 /* 1038 * Provide a machine specific interface to the conversion routine. By calling 1039 * the machine specific version, rather than the generic version, we insure that 1040 * the data tables/strings for all known machine versions aren't dragged into 1041 * ld.so.1. 1042 */ 1043 const char * 1044 _conv_reloc_type(uint_t rel) 1045 { 1046 static Conv_inv_buf_t inv_buf; 1047 1048 return (conv_reloc_amd64_type(rel, 0, &inv_buf)); 1049 } 1050