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 2009 Sun Microsystems, Inc. All rights reserved. 27 * Use is subject to license terms. 28 */ 29 30 /* 31 * This file contains the functions responsible for opening the output file 32 * image, associating the appropriate input elf structures with the new image, 33 * and obtaining new elf structures to define the new image. 34 */ 35 #include <stdio.h> 36 #include <sys/stat.h> 37 #include <fcntl.h> 38 #include <link.h> 39 #include <errno.h> 40 #include <string.h> 41 #include <limits.h> 42 #include <debug.h> 43 #include <unistd.h> 44 #include "msg.h" 45 #include "_libld.h" 46 47 /* 48 * Determine a least common multiplier. Input sections contain an alignment 49 * requirement, which elf_update() uses to insure that the section is aligned 50 * correctly off of the base of the elf image. We must also insure that the 51 * sections mapping is congruent with this alignment requirement. For each 52 * input section associated with a loadable segment determine whether the 53 * segments alignment must be adjusted to compensate for a sections alignment 54 * requirements. 55 */ 56 Xword 57 ld_lcm(Xword a, Xword b) 58 { 59 Xword _r, _a, _b; 60 61 if ((_a = a) == 0) 62 return (b); 63 if ((_b = b) == 0) 64 return (a); 65 66 if (_a > _b) 67 _a = b, _b = a; 68 while ((_r = _b % _a) != 0) 69 _b = _a, _a = _r; 70 return ((a / _a) * b); 71 } 72 73 /* 74 * Open the output file and insure the correct access modes. 75 */ 76 uintptr_t 77 ld_open_outfile(Ofl_desc * ofl) 78 { 79 mode_t mode; 80 struct stat status; 81 82 /* 83 * Determine the required file mode from the type of output file we 84 * are creating. 85 */ 86 mode = (ofl->ofl_flags & (FLG_OF_EXEC | FLG_OF_SHAROBJ)) 87 ? 0777 : 0666; 88 89 /* Determine if the output file already exists */ 90 if (stat(ofl->ofl_name, &status) == 0) { 91 if ((status.st_mode & S_IFMT) != S_IFREG) { 92 /* 93 * It is not a regular file, so don't delete it 94 * or allow it to be deleted. This allows root 95 * users to specify /dev/null output file for 96 * verification links. 97 */ 98 ofl->ofl_flags1 |= FLG_OF1_NONREG; 99 } else { 100 /* 101 * It's a regular file, so unlink it. In standard 102 * Unix fashion, the old file will continue to 103 * exist until its link count drops to 0 and no 104 * process has the file open. In the meantime, we 105 * create a new file (inode) under the same name, 106 * available for new use. 107 * 108 * The advantage of this policy is that creating 109 * a new executable or sharable library does not 110 * corrupt existing processes using the old file. 111 * A possible disadvantage is that if the existing 112 * file has a (link_count > 1), the other names will 113 * continue to reference the old inode, thus 114 * breaking the link. 115 * 116 * A subtlety here is that POSIX says we are not 117 * supposed to replace a non-writable file, which 118 * is something that unlink() is happy to do. The 119 * only 100% reliable test against this is to open 120 * the file for non-destructive write access. If the 121 * open succeeds, we are clear to unlink it, and if 122 * not, then the error generated is the error we 123 * need to report. 124 */ 125 if ((ofl->ofl_fd = open(ofl->ofl_name, O_RDWR, 126 mode)) < 0) { 127 int err = errno; 128 129 if (err != ENOENT) { 130 eprintf(ofl->ofl_lml, ERR_FATAL, 131 MSG_INTL(MSG_SYS_OPEN), 132 ofl->ofl_name, strerror(err)); 133 return (S_ERROR); 134 } 135 } else { 136 (void) close(ofl->ofl_fd); 137 } 138 139 if ((unlink(ofl->ofl_name) == -1) && 140 (errno != ENOENT)) { 141 int err = errno; 142 143 eprintf(ofl->ofl_lml, ERR_FATAL, 144 MSG_INTL(MSG_SYS_UNLINK), 145 ofl->ofl_name, strerror(err)); 146 return (S_ERROR); 147 } 148 } 149 } 150 151 /* 152 * Open (or create) the output file name (ofl_fd acts as a global 153 * flag to ldexit() signifying whether the output file should be 154 * removed or not on error). 155 */ 156 if ((ofl->ofl_fd = open(ofl->ofl_name, O_RDWR | O_CREAT | O_TRUNC, 157 mode)) < 0) { 158 int err = errno; 159 160 eprintf(ofl->ofl_lml, ERR_FATAL, MSG_INTL(MSG_SYS_OPEN), 161 ofl->ofl_name, strerror(err)); 162 return (S_ERROR); 163 } 164 165 return (1); 166 } 167 168 169 /* 170 * If we are creating a memory model we need to update the present memory image. 171 * First we need to call elf_update(ELF_C_NULL) which will calculate the offsets 172 * of each section and its associated data buffers. From this information we 173 * can then determine what padding is required. 174 * Two actions are necessary to convert the present disc image into a memory 175 * image: 176 * 177 * o Loadable segments must be padded so that the next segments virtual 178 * address and file offset are the same. 179 * 180 * o NOBITS sections must be converted into allocated, null filled sections. 181 */ 182 static uintptr_t 183 pad_outfile(Ofl_desc *ofl) 184 { 185 Aliste idx1; 186 off_t offset; 187 Elf_Scn *oscn = 0; 188 Sg_desc *sgp; 189 Ehdr *ehdr; 190 191 /* 192 * Update all the elf structures. This will assign offsets to the 193 * section headers and data buffers as they relate to the new image. 194 */ 195 if (elf_update(ofl->ofl_welf, ELF_C_NULL) == -1) { 196 eprintf(ofl->ofl_lml, ERR_ELF, MSG_INTL(MSG_ELF_UPDATE), 197 ofl->ofl_name); 198 return (S_ERROR); 199 } 200 if ((ehdr = elf_getehdr(ofl->ofl_welf)) == NULL) { 201 eprintf(ofl->ofl_lml, ERR_ELF, MSG_INTL(MSG_ELF_GETEHDR), 202 ofl->ofl_name); 203 return (S_ERROR); 204 } 205 206 /* 207 * Initialize the offset by skipping the Elf header and program 208 * headers. 209 */ 210 offset = ehdr->e_phoff + (ehdr->e_phnum * ehdr->e_phentsize); 211 212 /* 213 * Traverse the segment list looking for loadable segments. 214 */ 215 for (APLIST_TRAVERSE(ofl->ofl_segs, idx1, sgp)) { 216 Phdr *phdr = &(sgp->sg_phdr); 217 Os_desc *osp; 218 Aliste idx2; 219 220 /* 221 * If we've already processed a loadable segment, the `scn' 222 * variable will be initialized to the last section that was 223 * part of that segment. Add sufficient padding to this section 224 * to cause the next segments virtual address and file offset to 225 * be the same. 226 */ 227 if (oscn && (phdr->p_type == PT_LOAD)) { 228 Elf_Data * data; 229 size_t size; 230 231 size = (size_t)(S_ROUND(offset, phdr->p_align) - 232 offset); 233 234 if ((data = elf_newdata(oscn)) == NULL) { 235 eprintf(ofl->ofl_lml, ERR_ELF, 236 MSG_INTL(MSG_ELF_NEWDATA), ofl->ofl_name); 237 return (S_ERROR); 238 } 239 if ((data->d_buf = libld_calloc(size, 1)) == 0) 240 return (S_ERROR); 241 242 data->d_type = ELF_T_BYTE; 243 data->d_size = size; 244 data->d_align = 1; 245 data->d_version = ofl->ofl_dehdr->e_version; 246 } 247 248 /* 249 * Traverse the output sections for this segment calculating the 250 * offset of each section. Retain the final section descriptor 251 * as this will be where any padding buffer will be added. 252 */ 253 for (APLIST_TRAVERSE(sgp->sg_osdescs, idx2, osp)) { 254 Shdr *shdr = osp->os_shdr; 255 256 offset = (off_t)S_ROUND(offset, shdr->sh_addralign); 257 offset += shdr->sh_size; 258 259 /* 260 * If this is a NOBITS output section convert all of 261 * its associated input sections into real, null filled, 262 * data buffers, and change the section to PROGBITS. 263 */ 264 if (shdr->sh_type == SHT_NOBITS) 265 shdr->sh_type = SHT_PROGBITS; 266 } 267 268 /* 269 * If this is a loadable segment retain the last output section 270 * descriptor. This acts both as a flag that a loadable 271 * segment has been seen, and as the segment to which a padding 272 * buffer will be added. 273 */ 274 if (phdr->p_type == PT_LOAD) 275 oscn = osp->os_scn; 276 } 277 return (1); 278 } 279 280 /* 281 * Create an output section. The first instance of an input section triggers 282 * the creation of a new output section. 283 */ 284 static uintptr_t 285 create_outsec(Ofl_desc *ofl, Sg_desc *sgp, Os_desc *osp, Word ptype, int shidx, 286 Boolean fixalign) 287 { 288 Elf_Scn *scn; 289 Shdr *shdr; 290 291 /* 292 * Get a section descriptor for the section. 293 */ 294 if ((scn = elf_newscn(ofl->ofl_welf)) == NULL) { 295 eprintf(ofl->ofl_lml, ERR_ELF, MSG_INTL(MSG_ELF_NEWSCN), 296 ofl->ofl_name); 297 return (S_ERROR); 298 } 299 osp->os_scn = scn; 300 301 /* 302 * Get a new section header table entry and copy the pertinent 303 * information from the in-core descriptor. 304 */ 305 if ((shdr = elf_getshdr(scn)) == NULL) { 306 eprintf(ofl->ofl_lml, ERR_ELF, MSG_INTL(MSG_ELF_GETSHDR), 307 ofl->ofl_name); 308 return (S_ERROR); 309 } 310 *shdr = *(osp->os_shdr); 311 osp->os_shdr = shdr; 312 313 /* 314 * If this is the first section within a loadable segment, and the 315 * alignment needs to be updated, record this section. 316 */ 317 if ((fixalign == TRUE) && (ptype == PT_LOAD) && (shidx == 1)) 318 sgp->sg_fscn = scn; 319 320 /* 321 * If not building a relocatable object, remove any of the 322 * following flags, as they have been acted upon and are not 323 * meaningful in the output: 324 * SHF_ORDERED, SHF_LINK_ORDER, SHF_GROUP 325 * For relocatable objects, we allow them to propagate to 326 * the output object to be handled by the next linker that 327 * sees them. 328 */ 329 if ((ofl->ofl_flags & FLG_OF_RELOBJ) == 0) 330 osp->os_shdr->sh_flags &= ~(ALL_SHF_ORDER|SHF_GROUP); 331 332 /* 333 * If this is a TLS section, save it so that the PT_TLS program header 334 * information can be established after the output image has been 335 * initially created. At this point, all TLS input sections are ordered 336 * as they will appear in the output image. 337 */ 338 if ((ofl->ofl_flags & FLG_OF_TLSPHDR) && 339 (osp->os_shdr->sh_flags & SHF_TLS) && 340 (aplist_append(&ofl->ofl_ostlsseg, osp, 341 AL_CNT_OFL_OSTLSSEG) == NULL)) 342 return (S_ERROR); 343 344 return (0); 345 } 346 347 /* 348 * Create the elf structures that allow the input data to be associated with the 349 * new image: 350 * 351 * o define the new elf image using elf_begin(), 352 * 353 * o obtain an elf header for the image, 354 * 355 * o traverse the input segments and create a program header array 356 * to define the required segments, 357 * 358 * o traverse the output sections for each segment assigning a new 359 * section descriptor and section header for each, 360 * 361 * o traverse the input sections associated with each output section 362 * and assign a new data descriptor to each (each output section 363 * becomes a linked list of input data buffers). 364 */ 365 uintptr_t 366 ld_create_outfile(Ofl_desc *ofl) 367 { 368 Sg_desc *sgp; 369 Os_desc *osp; 370 Is_desc *isp; 371 Elf_Data *tlsdata = 0; 372 Aliste idx1; 373 ofl_flag_t flags = ofl->ofl_flags; 374 ofl_flag_t flags1 = ofl->ofl_flags1; 375 size_t ndx; 376 Elf_Cmd cmd; 377 Boolean fixalign = FALSE; 378 int fd, nseg = 0, shidx, dataidx, ptloadidx = 0; 379 380 /* 381 * If DF_1_NOHDR was set in map_parse() or FLG_OF1_VADDR was set, 382 * we need to do alignment adjustment. 383 */ 384 if ((flags1 & FLG_OF1_VADDR) || 385 (ofl->ofl_dtflags_1 & DF_1_NOHDR)) { 386 fixalign = TRUE; 387 } 388 389 if (flags1 & FLG_OF1_MEMORY) { 390 cmd = ELF_C_IMAGE; 391 fd = 0; 392 } else { 393 fd = ofl->ofl_fd; 394 cmd = ELF_C_WRITE; 395 } 396 397 /* 398 * If there are any ordered sections, handle them here. 399 */ 400 if ((ofl->ofl_ordered != NULL) && 401 (ld_sort_ordered(ofl) == S_ERROR)) 402 return (S_ERROR); 403 404 /* 405 * Tell the access library about our new temporary file. 406 */ 407 if ((ofl->ofl_welf = elf_begin(fd, cmd, 0)) == NULL) { 408 eprintf(ofl->ofl_lml, ERR_ELF, MSG_INTL(MSG_ELF_BEGIN), 409 ofl->ofl_name); 410 return (S_ERROR); 411 } 412 413 /* 414 * Obtain a new Elf header. 415 */ 416 if ((ofl->ofl_nehdr = elf_newehdr(ofl->ofl_welf)) == NULL) { 417 eprintf(ofl->ofl_lml, ERR_ELF, MSG_INTL(MSG_ELF_NEWEHDR), 418 ofl->ofl_name); 419 return (S_ERROR); 420 } 421 ofl->ofl_nehdr->e_machine = ofl->ofl_dehdr->e_machine; 422 423 DBG_CALL(Dbg_util_nl(ofl->ofl_lml, DBG_NL_STD)); 424 for (APLIST_TRAVERSE(ofl->ofl_segs, idx1, sgp)) { 425 int frst = 0; 426 Phdr *phdr = &(sgp->sg_phdr); 427 Word ptype = phdr->p_type; 428 Aliste idx2; 429 430 /* 431 * Count the number of segments that will go in the program 432 * header table. If a segment is empty, ignore it. 433 */ 434 if (!(flags & FLG_OF_RELOBJ)) { 435 /* 436 * If the program header type belongs to the os range, 437 * the resulting object is ELFOSABI_SOLARIS. 438 */ 439 if ((ptype >= PT_LOOS) && (ptype <= PT_HIOS)) 440 ofl->ofl_flags |= FLG_OF_OSABI; 441 442 if (ptype == PT_PHDR) { 443 /* 444 * If we are generating an interp section (and 445 * thus an associated PT_INTERP program header 446 * entry) also generate a PT_PHDR program header 447 * entry. This allows the kernel to generate 448 * the appropriate aux vector entries to pass to 449 * the interpreter (refer to exec/elf/elf.c). 450 * Note that if an image was generated with an 451 * interp section, but no associated PT_PHDR 452 * program header entry, the kernel will simply 453 * pass the interpreter an open file descriptor 454 * when the image is executed). 455 */ 456 if (ofl->ofl_osinterp) 457 nseg++; 458 } else if (ptype == PT_INTERP) { 459 if (ofl->ofl_osinterp) 460 nseg++; 461 } else if (ptype == PT_DYNAMIC) { 462 if (flags & FLG_OF_DYNAMIC) 463 nseg++; 464 } else if (ptype == PT_TLS) { 465 if (flags & FLG_OF_TLSPHDR) 466 nseg++; 467 } else if (ptype == PT_SUNW_UNWIND) { 468 if (ofl->ofl_unwindhdr) 469 nseg++; 470 } else if (ptype == PT_SUNWDTRACE) { 471 if (ofl->ofl_dtracesym) 472 nseg++; 473 } else if (ptype == PT_SUNWCAP) { 474 if (ofl->ofl_oscap) 475 nseg++; 476 } else if (sgp->sg_flags & FLG_SG_EMPTY) { 477 nseg++; 478 } else if (sgp->sg_osdescs != NULL) { 479 if ((sgp->sg_flags & FLG_SG_PHREQ) == 0) { 480 /* 481 * If this is a segment for which 482 * we are not making a program header, 483 * don't increment nseg 484 */ 485 ptype = (sgp->sg_phdr).p_type = PT_NULL; 486 } else if (ptype != PT_NULL) 487 nseg++; 488 } 489 } 490 491 /* 492 * Establish any processing unique to the first loadable 493 * segment. 494 */ 495 if ((ptype == PT_LOAD) && (ptloadidx == 0)) { 496 ptloadidx++; 497 498 /* 499 * If the first loadable segment has the ?N flag then 500 * alignments of following segments need to be fixed, 501 * plus a .dynamic FLAGS1 setting is required. 502 */ 503 if (sgp->sg_flags & FLG_SG_NOHDR) { 504 fixalign = TRUE; 505 ofl->ofl_dtflags_1 |= DF_1_NOHDR; 506 } 507 } 508 509 shidx = 0; 510 for (APLIST_TRAVERSE(sgp->sg_osdescs, idx2, osp)) { 511 Aliste idx3; 512 513 dataidx = 0; 514 for (APLIST_TRAVERSE(osp->os_isdescs, idx3, isp)) { 515 Elf_Data *data; 516 Ifl_desc *ifl = isp->is_file; 517 518 /* 519 * An input section in the list that has 520 * been previously marked to be discarded 521 * should be completely ignored. 522 */ 523 if (isp->is_flags & FLG_IS_DISCARD) 524 continue; 525 526 /* 527 * At this point we know whether a section has 528 * been referenced. If it hasn't, and the whole 529 * file hasn't been referenced (which would have 530 * been caught in ignore_section_processing()), 531 * give a diagnostic (-D unused,detail) or 532 * discard the section if -zignore is in effect. 533 */ 534 if (ifl && 535 (((ifl->ifl_flags & FLG_IF_FILEREF) == 0) || 536 ((ptype == PT_LOAD) && 537 ((isp->is_flags & FLG_IS_SECTREF) == 0) && 538 (isp->is_shdr->sh_size > 0)))) { 539 Lm_list *lml = ofl->ofl_lml; 540 541 if (ifl->ifl_flags & FLG_IF_IGNORE) { 542 isp->is_flags |= FLG_IS_DISCARD; 543 DBG_CALL(Dbg_unused_sec(lml, 544 isp)); 545 continue; 546 } else { 547 DBG_CALL(Dbg_unused_sec(lml, 548 isp)); 549 } 550 } 551 552 /* 553 * If this section provides no data, and isn't 554 * referenced, then it can be discarded as well. 555 * Note, if this is the first input section 556 * associated to an output section, let it 557 * through, there may be a legitimate reason why 558 * the user wants a null section. Discarding 559 * additional sections is intended to remove the 560 * empty clutter the compilers have a habit of 561 * creating. Don't provide an unused diagnostic 562 * as these sections aren't typically the users 563 * creation. 564 */ 565 if (ifl && dataidx && 566 ((isp->is_flags & FLG_IS_SECTREF) == 0) && 567 (isp->is_shdr->sh_size == 0)) { 568 isp->is_flags |= FLG_IS_DISCARD; 569 continue; 570 } 571 572 /* 573 * The first input section triggers the creation 574 * of the associated output section. 575 */ 576 if (osp->os_scn == NULL) { 577 shidx++; 578 579 if (create_outsec(ofl, sgp, osp, ptype, 580 shidx, fixalign) == S_ERROR) 581 return (S_ERROR); 582 } 583 584 dataidx++; 585 586 /* 587 * Create a new output data buffer for each 588 * input data buffer, thus linking the new 589 * buffers to the new elf output structures. 590 * Simply make the new data buffers point to 591 * the old data. 592 */ 593 if ((data = elf_newdata(osp->os_scn)) == NULL) { 594 eprintf(ofl->ofl_lml, ERR_ELF, 595 MSG_INTL(MSG_ELF_NEWDATA), 596 ofl->ofl_name); 597 return (S_ERROR); 598 } 599 *data = *(isp->is_indata); 600 isp->is_indata = data; 601 602 if ((fixalign == TRUE) && (ptype == PT_LOAD) && 603 (shidx == 1) && (dataidx == 1)) 604 data->d_align = sgp->sg_addralign; 605 606 /* 607 * Save the first TLS data buffer, as this is 608 * the start of the TLS segment. Realign this 609 * buffer based on the alignment requirements 610 * of all the TLS input sections. 611 */ 612 if ((flags & FLG_OF_TLSPHDR) && 613 (isp->is_shdr->sh_flags & SHF_TLS)) { 614 if (tlsdata == 0) 615 tlsdata = data; 616 tlsdata->d_align = 617 ld_lcm(tlsdata->d_align, 618 isp->is_shdr->sh_addralign); 619 } 620 621 #if defined(_ELF64) && defined(_ILP32) 622 /* 623 * 4106312, the 32-bit ELF64 version of ld 624 * needs to be able to create large .bss 625 * sections. The d_size member of Elf_Data 626 * only allows 32-bits in _ILP32, so we build 627 * multiple data-items that each fit into 32- 628 * bits. libelf (4106398) can summ these up 629 * into a 64-bit quantity. This only works 630 * for NOBITS sections which don't have any 631 * real data to maintain and don't require 632 * large file support. 633 */ 634 if (isp->is_shdr->sh_type == SHT_NOBITS) { 635 Xword sz = isp->is_shdr->sh_size; 636 637 while (sz >> 32) { 638 data->d_size = SIZE_MAX; 639 sz -= (Xword)SIZE_MAX; 640 641 data = elf_newdata(osp->os_scn); 642 if (data == NULL) 643 return (S_ERROR); 644 } 645 data->d_size = (size_t)sz; 646 } 647 #endif 648 649 /* 650 * If this segment requires rounding realign the 651 * first data buffer associated with the first 652 * section. 653 */ 654 if ((frst++ == 0) && 655 (sgp->sg_flags & FLG_SG_ROUND)) { 656 Xword align; 657 658 if (data->d_align) 659 align = (Xword) 660 S_ROUND(data->d_align, 661 sgp->sg_round); 662 else 663 align = sgp->sg_round; 664 665 data->d_align = (size_t)align; 666 } 667 } 668 669 /* 670 * Clear the szoutrels counter so that it can be used 671 * again in the building of relocs. See machrel.c. 672 */ 673 osp->os_szoutrels = 0; 674 } 675 } 676 677 /* 678 * Did we use ELF features from the osabi range? If so, 679 * update the ELF header osabi fields. If this doesn't happen, 680 * those fields remain 0, reflecting a generic System V ELF ABI. 681 */ 682 if (ofl->ofl_flags & FLG_OF_OSABI) { 683 ofl->ofl_nehdr->e_ident[EI_OSABI] = ELFOSABI_SOLARIS; 684 ofl->ofl_nehdr->e_ident[EI_ABIVERSION] = EAV_SUNW_CURRENT; 685 } 686 687 /* 688 * Build an empty PHDR. 689 */ 690 if (nseg) { 691 if ((ofl->ofl_phdr = elf_newphdr(ofl->ofl_welf, 692 nseg)) == NULL) { 693 eprintf(ofl->ofl_lml, ERR_ELF, 694 MSG_INTL(MSG_ELF_NEWPHDR), ofl->ofl_name); 695 return (S_ERROR); 696 } 697 } 698 699 /* 700 * If we need to generate a memory model, pad the image. 701 */ 702 if (flags1 & FLG_OF1_MEMORY) { 703 if (pad_outfile(ofl) == S_ERROR) 704 return (S_ERROR); 705 } 706 707 /* 708 * After all the basic input file processing, all data pointers are 709 * referencing two types of memory: 710 * 711 * o allocated memory, ie. elf structures, internal link 712 * editor structures, and any new sections that have been 713 * created. 714 * 715 * o original input file mmap'ed memory, ie. the actual data 716 * sections of the input file images. 717 * 718 * Up until now, the only memory modifications have been carried out on 719 * the allocated memory. Before carrying out any relocations, write the 720 * new output file image and reassign any necessary data pointers to the 721 * output files memory image. This insures that any relocation 722 * modifications are made to the output file image and not to the input 723 * file image, thus preventing the creation of dirty pages and reducing 724 * the overall swap space requirement. 725 * 726 * Write out the elf structure so as to create the new file image. 727 */ 728 if ((ofl->ofl_size = (size_t)elf_update(ofl->ofl_welf, 729 ELF_C_WRIMAGE)) == (size_t)-1) { 730 eprintf(ofl->ofl_lml, ERR_ELF, MSG_INTL(MSG_ELF_UPDATE), 731 ofl->ofl_name); 732 return (S_ERROR); 733 } 734 735 /* 736 * Initialize the true `ofl' information with the memory images address 737 * and size. This will be used to write() out the image once any 738 * relocation processing has been completed. We also use this image 739 * information to setup a new Elf descriptor, which is used to obtain 740 * all the necessary elf pointers within the new output image. 741 */ 742 if ((ofl->ofl_elf = elf_begin(0, ELF_C_IMAGE, 743 ofl->ofl_welf)) == NULL) { 744 eprintf(ofl->ofl_lml, ERR_ELF, MSG_INTL(MSG_ELF_BEGIN), 745 ofl->ofl_name); 746 return (S_ERROR); 747 } 748 if ((ofl->ofl_nehdr = elf_getehdr(ofl->ofl_elf)) == NULL) { 749 eprintf(ofl->ofl_lml, ERR_ELF, MSG_INTL(MSG_ELF_GETEHDR), 750 ofl->ofl_name); 751 return (S_ERROR); 752 } 753 if (!(flags & FLG_OF_RELOBJ)) 754 if ((ofl->ofl_phdr = elf_getphdr(ofl->ofl_elf)) == NULL) { 755 eprintf(ofl->ofl_lml, ERR_ELF, 756 MSG_INTL(MSG_ELF_GETPHDR), ofl->ofl_name); 757 return (S_ERROR); 758 } 759 760 /* 761 * Reinitialize the section descriptors, section headers and obtain new 762 * output data buffer pointers (these will be used to perform any 763 * relocations). 764 */ 765 ndx = 0; 766 for (APLIST_TRAVERSE(ofl->ofl_segs, idx1, sgp)) { 767 Phdr *_phdr = &(sgp->sg_phdr); 768 Os_desc *osp; 769 Aliste idx2; 770 Boolean recorded = FALSE; 771 772 for (APLIST_TRAVERSE(sgp->sg_osdescs, idx2, osp)) { 773 /* 774 * Make sure that an output section was originally 775 * created. Input sections that had been marked as 776 * discarded may have made an output section 777 * unnecessary. Remove this alist entry so that 778 * future output section descriptor processing doesn't 779 * have to compensate for this empty section. 780 */ 781 if (osp->os_scn == NULL) { 782 aplist_delete(sgp->sg_osdescs, &idx2); 783 continue; 784 } 785 if ((osp->os_scn = 786 elf_getscn(ofl->ofl_elf, ++ndx)) == NULL) { 787 eprintf(ofl->ofl_lml, ERR_ELF, 788 MSG_INTL(MSG_ELF_GETSCN), ofl->ofl_name, 789 ndx); 790 return (S_ERROR); 791 } 792 if ((osp->os_shdr = 793 elf_getshdr(osp->os_scn)) == NULL) { 794 eprintf(ofl->ofl_lml, ERR_ELF, 795 MSG_INTL(MSG_ELF_GETSHDR), ofl->ofl_name); 796 return (S_ERROR); 797 } 798 if ((fixalign == TRUE) && sgp->sg_fscn && 799 (recorded == FALSE)) { 800 size_t fndx; 801 Elf_Scn *scn; 802 803 scn = sgp->sg_fscn; 804 if ((fndx = elf_ndxscn(scn)) == SHN_UNDEF) { 805 eprintf(ofl->ofl_lml, ERR_ELF, 806 MSG_INTL(MSG_ELF_NDXSCN), 807 ofl->ofl_name); 808 return (S_ERROR); 809 } 810 if (ndx == fndx) { 811 sgp->sg_fscn = osp->os_scn; 812 recorded = TRUE; 813 } 814 } 815 816 if ((osp->os_outdata = 817 elf_getdata(osp->os_scn, NULL)) == NULL) { 818 eprintf(ofl->ofl_lml, ERR_ELF, 819 MSG_INTL(MSG_ELF_GETDATA), ofl->ofl_name); 820 return (S_ERROR); 821 } 822 823 /* 824 * If this section is part of a loadable segment insure 825 * that the segments alignment is appropriate. 826 */ 827 if (_phdr->p_type == PT_LOAD) { 828 _phdr->p_align = ld_lcm(_phdr->p_align, 829 osp->os_shdr->sh_addralign); 830 } 831 } 832 } 833 return (1); 834 } 835