2 * Copyright (c) 2006-2008 Joseph Koshy
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
31 #include <sys/param.h>
44 * Update the internal data structures associated with an ELF object.
45 * Returns the size in bytes the ELF object would occupy in its file
48 * After a successful call to this function, the following structures
51 * - The ELF header is updated.
52 * - All sections are sorted in order of ascending addresses and their
53 * section header table entries updated. An error is signalled
54 * if an overlap was detected among sections.
55 * - All data descriptors associated with a section are sorted in order
56 * of ascending addresses. Overlaps, if detected, are signalled as
57 * errors. Other sanity checks for alignments, section types etc. are
60 * After a resync_elf() successfully returns, the ELF descriptor is
61 * ready for being handed over to _libelf_write_elf().
67 * XXX: how do we handle 'flags'.
71 * Compute the extents of a section, by looking at the data
72 * descriptors associated with it. The function returns zero if an
73 * error was detected. `*rc' holds the maximum file extent seen so
77 _libelf_compute_section_extents(Elf *e, Elf_Scn *s, off_t *rc)
84 uint64_t sh_align, sh_entsize, sh_offset, sh_size;
85 uint64_t scn_size, scn_alignment;
88 * We need to recompute library private data structures if one
89 * or more of the following is true:
90 * - The underlying Shdr structure has been marked `dirty'. Significant
91 * fields include: `sh_offset', `sh_type', `sh_size', `sh_addralign'.
92 * - The Elf_Data structures part of this section have been marked
93 * `dirty'. Affected members include `d_align', `d_offset', `d_type',
95 * - The section as a whole is `dirty', e.g., it has been allocated
96 * using elf_newscn(), or if a new Elf_Data structure was added using
99 * Each of these conditions would result in the ELF_F_DIRTY bit being
100 * set on the section descriptor's `s_flags' field.
105 if (ec == ELFCLASS32) {
106 sh_type = s->s_shdr.s_shdr32.sh_type;
107 sh_align = (uint64_t) s->s_shdr.s_shdr32.sh_addralign;
108 sh_entsize = (uint64_t) s->s_shdr.s_shdr32.sh_entsize;
109 sh_offset = (uint64_t) s->s_shdr.s_shdr32.sh_offset;
110 sh_size = (uint64_t) s->s_shdr.s_shdr32.sh_size;
112 sh_type = s->s_shdr.s_shdr64.sh_type;
113 sh_align = s->s_shdr.s_shdr64.sh_addralign;
114 sh_entsize = s->s_shdr.s_shdr64.sh_entsize;
115 sh_offset = s->s_shdr.s_shdr64.sh_offset;
116 sh_size = s->s_shdr.s_shdr64.sh_size;
119 if (sh_type == SHT_NULL || sh_type == SHT_NOBITS)
122 if ((s->s_flags & ELF_F_DIRTY) == 0) {
123 if ((size_t) *rc < sh_offset + sh_size)
124 *rc = sh_offset + sh_size;
128 elftype = _libelf_xlate_shtype(sh_type);
129 if (elftype > ELF_T_LAST) {
130 LIBELF_SET_ERROR(SECTION, 0);
135 * Compute the extent of the data descriptors associated with
140 sh_align = _libelf_falign(elftype, ec);
142 /* Compute the section alignment. */
143 STAILQ_FOREACH(d, &s->s_data, d_next) {
144 if (d->d_type > ELF_T_LAST) {
145 LIBELF_SET_ERROR(DATA, 0);
148 if (d->d_version != e->e_version) {
149 LIBELF_SET_ERROR(VERSION, 0);
152 if ((d_align = d->d_align) == 0 || (d_align & (d_align - 1))) {
153 LIBELF_SET_ERROR(DATA, 0);
156 if (d_align > scn_alignment)
157 scn_alignment = d_align;
162 STAILQ_FOREACH_SAFE(d, &s->s_data, d_next, td) {
163 if (e->e_flags & ELF_F_LAYOUT) {
164 if ((uint64_t) d->d_off + d->d_size > scn_size)
165 scn_size = d->d_off + d->d_size;
167 scn_size = roundup2(scn_size, d->d_align);
169 scn_size += d->d_size;
174 * If the application is requesting full control over the layout
175 * of the section, check its values for sanity.
177 if (e->e_flags & ELF_F_LAYOUT) {
178 if (scn_alignment > sh_align || sh_offset % sh_align ||
179 sh_size < scn_size) {
180 LIBELF_SET_ERROR(LAYOUT, 0);
185 * Otherwise compute the values in the section header.
188 if (scn_alignment > sh_align)
189 sh_align = scn_alignment;
192 * If the section entry size is zero, try and fill in an
193 * appropriate entry size. Per the elf(5) manual page
194 * sections without fixed-size entries should have their
195 * 'sh_entsize' field set to zero.
197 if (sh_entsize == 0 &&
198 (sh_entsize = _libelf_fsize(elftype, ec, e->e_version,
203 sh_offset = roundup(*rc, sh_align);
205 if (ec == ELFCLASS32) {
206 s->s_shdr.s_shdr32.sh_addralign = (uint32_t) sh_align;
207 s->s_shdr.s_shdr32.sh_entsize = (uint32_t) sh_entsize;
208 s->s_shdr.s_shdr32.sh_offset = (uint32_t) sh_offset;
209 s->s_shdr.s_shdr32.sh_size = (uint32_t) sh_size;
211 s->s_shdr.s_shdr64.sh_addralign = sh_align;
212 s->s_shdr.s_shdr64.sh_entsize = sh_entsize;
213 s->s_shdr.s_shdr64.sh_offset = sh_offset;
214 s->s_shdr.s_shdr64.sh_size = sh_size;
218 if ((size_t) *rc < sh_offset + sh_size)
219 *rc = sh_offset + sh_size;
222 s->s_offset = sh_offset;
228 * Insert a section in ascending order in the list
232 _libelf_insert_section(Elf *e, Elf_Scn *s)
235 uint64_t smax, smin, tmax, tmin;
238 smax = smin + s->s_size;
241 STAILQ_FOREACH(t, &e->e_u.e_elf.e_scn, s_next) {
243 tmax = tmin + t->s_size;
247 * 't' lies entirely before 's': ...| t |...| s |...
251 } else if (smax <= tmin)
253 * 's' lies entirely before 't', and after 'prevt':
254 * ...| prevt |...| s |...| t |...
257 else { /* 's' and 't' overlap. */
258 LIBELF_SET_ERROR(LAYOUT, 0);
264 STAILQ_INSERT_AFTER(&e->e_u.e_elf.e_scn, prevt, s, s_next);
266 STAILQ_INSERT_HEAD(&e->e_u.e_elf.e_scn, s, s_next);
271 _libelf_resync_sections(Elf *e, off_t rc)
275 size_t sh_type, shdr_start, shdr_end;
281 * Make a pass through sections, computing the extent of each
282 * section. Order in increasing order of addresses.
286 STAILQ_FOREACH(s, &e->e_u.e_elf.e_scn, s_next)
287 if (_libelf_compute_section_extents(e, s, &nrc) == 0)
290 STAILQ_FOREACH_SAFE(s, &e->e_u.e_elf.e_scn, s_next, ts) {
291 if (ec == ELFCLASS32)
292 sh_type = s->s_shdr.s_shdr32.sh_type;
294 sh_type = s->s_shdr.s_shdr64.sh_type;
296 if (sh_type == SHT_NOBITS || sh_type == SHT_NULL)
299 if (s->s_offset < (uint64_t) rc) {
300 if (s->s_offset + s->s_size < (uint64_t) rc) {
302 * Try insert this section in the
303 * correct place in the list,
304 * detecting overlaps if any.
306 STAILQ_REMOVE(&e->e_u.e_elf.e_scn, s, _Elf_Scn,
308 if (_libelf_insert_section(e, s) == 0)
311 LIBELF_SET_ERROR(LAYOUT, 0);
315 rc = s->s_offset + s->s_size;
319 * If the application is controlling file layout, check for an
320 * overlap between this section's extents and the SHDR table.
322 if (e->e_flags & ELF_F_LAYOUT) {
324 if (e->e_class == ELFCLASS32)
325 shdr_start = e->e_u.e_elf.e_ehdr.e_ehdr32->e_shoff;
327 shdr_start = e->e_u.e_elf.e_ehdr.e_ehdr64->e_shoff;
329 shdr_end = shdr_start + _libelf_fsize(ELF_T_SHDR, e->e_class,
330 e->e_version, e->e_u.e_elf.e_nscn);
332 STAILQ_FOREACH(s, &e->e_u.e_elf.e_scn, s_next) {
333 if (s->s_offset >= shdr_end ||
334 s->s_offset + s->s_size <= shdr_start)
336 LIBELF_SET_ERROR(LAYOUT, 0);
347 _libelf_resync_elf(Elf *e)
349 int ec, eh_class, eh_type;
350 unsigned int eh_byteorder, eh_version;
353 off_t rc, phoff, shoff;
362 assert(ec == ELFCLASS32 || ec == ELFCLASS64);
367 if ((ehdr = _libelf_ehdr(e, ec, 0)) == NULL)
373 if (ec == ELFCLASS32) {
374 eh_byteorder = eh32->e_ident[EI_DATA];
375 eh_class = eh32->e_ident[EI_CLASS];
376 phoff = (uint64_t) eh32->e_phoff;
377 shoff = (uint64_t) eh32->e_shoff;
378 eh_type = eh32->e_type;
379 eh_version = eh32->e_version;
381 eh_byteorder = eh64->e_ident[EI_DATA];
382 eh_class = eh64->e_ident[EI_CLASS];
383 phoff = eh64->e_phoff;
384 shoff = eh64->e_shoff;
385 eh_type = eh64->e_type;
386 eh_version = eh64->e_version;
389 if (eh_version == EV_NONE)
390 eh_version = EV_CURRENT;
392 if (eh_version != e->e_version) { /* always EV_CURRENT */
393 LIBELF_SET_ERROR(VERSION, 0);
397 if (eh_class != e->e_class) {
398 LIBELF_SET_ERROR(CLASS, 0);
402 if (e->e_cmd != ELF_C_WRITE && eh_byteorder != e->e_byteorder) {
403 LIBELF_SET_ERROR(HEADER, 0);
407 shnum = e->e_u.e_elf.e_nscn;
408 phnum = e->e_u.e_elf.e_nphdr;
410 e->e_byteorder = eh_byteorder;
412 #define INITIALIZE_EHDR(E,EC,V) do { \
413 (E)->e_ident[EI_MAG0] = ELFMAG0; \
414 (E)->e_ident[EI_MAG1] = ELFMAG1; \
415 (E)->e_ident[EI_MAG2] = ELFMAG2; \
416 (E)->e_ident[EI_MAG3] = ELFMAG3; \
417 (E)->e_ident[EI_CLASS] = (EC); \
418 (E)->e_ident[EI_VERSION] = (V); \
419 (E)->e_ehsize = _libelf_fsize(ELF_T_EHDR, (EC), (V), \
421 (E)->e_phentsize = (phnum == 0) ? 0 : _libelf_fsize( \
422 ELF_T_PHDR, (EC), (V), (size_t) 1); \
423 (E)->e_shentsize = _libelf_fsize(ELF_T_SHDR, (EC), (V), \
427 if (ec == ELFCLASS32)
428 INITIALIZE_EHDR(eh32, ec, eh_version);
430 INITIALIZE_EHDR(eh64, ec, eh_version);
432 (void) elf_flagehdr(e, ELF_C_SET, ELF_F_DIRTY);
434 rc += _libelf_fsize(ELF_T_EHDR, ec, eh_version, (size_t) 1);
437 * Compute the layout the program header table, if one is
438 * present. The program header table needs to be aligned to a
439 * `natural' boundary.
442 fsz = _libelf_fsize(ELF_T_PHDR, ec, eh_version, phnum);
443 align = _libelf_falign(ELF_T_PHDR, ec);
445 if (e->e_flags & ELF_F_LAYOUT) {
447 * Check offsets for sanity.
450 LIBELF_SET_ERROR(HEADER, 0);
455 LIBELF_SET_ERROR(LAYOUT, 0);
460 phoff = roundup(rc, align);
467 * Compute the layout of the sections associated with the
471 if (e->e_cmd != ELF_C_WRITE &&
472 (e->e_flags & LIBELF_F_SHDRS_LOADED) == 0 &&
473 _libelf_load_scn(e, ehdr) == 0)
476 if ((rc = _libelf_resync_sections(e, rc)) < 0)
480 * Compute the space taken up by the section header table, if
481 * one is needed. If ELF_F_LAYOUT is asserted, the
482 * application may have placed the section header table in
483 * between existing sections, so the net size of the file need
484 * not increase due to the presence of the section header
488 fsz = _libelf_fsize(ELF_T_SHDR, ec, eh_version, (size_t) 1);
489 align = _libelf_falign(ELF_T_SHDR, ec);
491 if (e->e_flags & ELF_F_LAYOUT) {
493 LIBELF_SET_ERROR(LAYOUT, 0);
497 shoff = roundup(rc, align);
499 if (shoff + fsz * shnum > (size_t) rc)
500 rc = shoff + fsz * shnum;
505 * Set the fields of the Executable Header that could potentially use
506 * extended numbering.
508 _libelf_setphnum(e, ehdr, ec, phnum);
509 _libelf_setshnum(e, ehdr, ec, shnum);
512 * Update the `e_phoff' and `e_shoff' fields if the library is
515 if ((e->e_flags & ELF_F_LAYOUT) == 0) {
516 if (ec == ELFCLASS32) {
517 eh32->e_phoff = (uint32_t) phoff;
518 eh32->e_shoff = (uint32_t) shoff;
520 eh64->e_phoff = (uint64_t) phoff;
521 eh64->e_shoff = (uint64_t) shoff;
529 * Write out the contents of a section.
533 _libelf_write_scn(Elf *e, char *nf, Elf_Scn *s, off_t rc)
536 size_t fsz, msz, nobjects;
538 uint64_t sh_off, sh_size;
542 if ((ec = e->e_class) == ELFCLASS32) {
543 sh_type = s->s_shdr.s_shdr32.sh_type;
544 sh_size = (uint64_t) s->s_shdr.s_shdr32.sh_size;
546 sh_type = s->s_shdr.s_shdr64.sh_type;
547 sh_size = s->s_shdr.s_shdr64.sh_size;
551 * Ignore sections that do not allocate space in the file.
553 if (sh_type == SHT_NOBITS || sh_type == SHT_NULL || sh_size == 0)
556 elftype = _libelf_xlate_shtype(sh_type);
557 assert(elftype >= ELF_T_FIRST && elftype <= ELF_T_LAST);
559 sh_off = s->s_offset;
560 assert(sh_off % _libelf_falign(elftype, ec) == 0);
563 * If the section has a `rawdata' descriptor, and the section
564 * contents have not been modified, use its contents directly.
565 * The `s_rawoff' member contains the offset into the original
566 * file, while `s_offset' contains its new location in the
570 if (STAILQ_EMPTY(&s->s_data)) {
572 if ((d = elf_rawdata(s, NULL)) == NULL)
575 STAILQ_FOREACH(d, &s->s_rawdata, d_next) {
576 if ((uint64_t) rc < sh_off + d->d_off)
577 (void) memset(nf + rc,
578 LIBELF_PRIVATE(fillchar), sh_off +
580 rc = sh_off + d->d_off;
582 assert(d->d_buf != NULL);
583 assert(d->d_type == ELF_T_BYTE);
584 assert(d->d_version == e->e_version);
586 (void) memcpy(nf + rc,
587 e->e_rawfile + s->s_rawoff + d->d_off, d->d_size);
596 * Iterate over the set of data descriptors for this section.
597 * The prior call to _libelf_resync_elf() would have setup the
598 * descriptors for this step.
601 dst.d_version = e->e_version;
603 STAILQ_FOREACH(d, &s->s_data, d_next) {
605 msz = _libelf_msize(d->d_type, ec, e->e_version);
607 if ((uint64_t) rc < sh_off + d->d_off)
608 (void) memset(nf + rc,
609 LIBELF_PRIVATE(fillchar), sh_off + d->d_off - rc);
611 rc = sh_off + d->d_off;
613 assert(d->d_buf != NULL);
614 assert(d->d_version == e->e_version);
615 assert(d->d_size % msz == 0);
617 nobjects = d->d_size / msz;
619 fsz = _libelf_fsize(d->d_type, ec, e->e_version, nobjects);
624 if (_libelf_xlate(&dst, d, e->e_byteorder, ec, ELF_TOFILE) ==
635 * Write out the file image.
637 * The original file could have been mapped in with an ELF_C_RDWR
638 * command and the application could have added new content or
639 * re-arranged its sections before calling elf_update(). Consequently
640 * its not safe to work `in place' on the original file. So we
641 * malloc() the required space for the updated ELF object and build
642 * the object there and write it out to the underlying file at the
643 * end. Note that the application may have opened the underlying file
644 * in ELF_C_RDWR and only retrieved/modified a few sections. We take
645 * care to avoid translating file sections unnecessarily.
647 * Gaps in the coverage of the file by the file's sections will be
648 * filled with the fill character set by elf_fill(3).
652 _libelf_write_elf(Elf *e, off_t newsize)
656 size_t fsz, msz, phnum, shnum;
657 uint64_t phoff, shoff;
665 assert(e->e_kind == ELF_K_ELF);
666 assert(e->e_cmd != ELF_C_READ);
667 assert(e->e_fd >= 0);
669 if ((newfile = malloc((size_t) newsize)) == NULL) {
670 LIBELF_SET_ERROR(RESOURCE, errno);
676 ehdr = _libelf_ehdr(e, ec, 0);
677 assert(ehdr != NULL);
679 phnum = e->e_u.e_elf.e_nphdr;
681 if (ec == ELFCLASS32) {
682 eh32 = (Elf32_Ehdr *) ehdr;
684 phoff = (uint64_t) eh32->e_phoff;
685 shnum = eh32->e_shnum;
686 shoff = (uint64_t) eh32->e_shoff;
688 eh64 = (Elf64_Ehdr *) ehdr;
690 phoff = eh64->e_phoff;
691 shnum = eh64->e_shnum;
692 shoff = eh64->e_shoff;
695 fsz = _libelf_fsize(ELF_T_EHDR, ec, e->e_version, (size_t) 1);
696 msz = _libelf_msize(ELF_T_EHDR, ec, e->e_version);
698 (void) memset(&dst, 0, sizeof(dst));
699 (void) memset(&src, 0, sizeof(src));
703 src.d_type = ELF_T_EHDR;
704 src.d_version = dst.d_version = e->e_version;
708 dst.d_buf = newfile + rc;
711 if (_libelf_xlate(&dst, &src, e->e_byteorder, ec, ELF_TOFILE) ==
718 * Write the program header table if present.
721 if (phnum != 0 && phoff != 0) {
722 assert((unsigned) rc <= phoff);
724 fsz = _libelf_fsize(ELF_T_PHDR, ec, e->e_version, phnum);
726 assert(phoff % _libelf_falign(ELF_T_PHDR, ec) == 0);
729 src.d_buf = _libelf_getphdr(e, ec);
730 src.d_version = dst.d_version = e->e_version;
731 src.d_type = ELF_T_PHDR;
732 src.d_size = phnum * _libelf_msize(ELF_T_PHDR, ec,
737 if ((uint64_t) rc < phoff)
738 (void) memset(newfile + rc,
739 LIBELF_PRIVATE(fillchar), phoff - rc);
741 dst.d_buf = newfile + rc;
743 if (_libelf_xlate(&dst, &src, e->e_byteorder, ec, ELF_TOFILE) ==
751 * Write out individual sections.
754 STAILQ_FOREACH(scn, &e->e_u.e_elf.e_scn, s_next)
755 if ((rc = _libelf_write_scn(e, newfile, scn, rc)) < 0)
759 * Write out the section header table, if required. Note that
760 * if flag ELF_F_LAYOUT has been set the section header table
761 * could reside in between byte ranges mapped by section
764 if (shnum != 0 && shoff != 0) {
765 if ((uint64_t) rc < shoff)
766 (void) memset(newfile + rc,
767 LIBELF_PRIVATE(fillchar), shoff - rc);
772 assert(rc % _libelf_falign(ELF_T_SHDR, ec) == 0);
774 src.d_type = ELF_T_SHDR;
775 src.d_size = _libelf_msize(ELF_T_SHDR, ec, e->e_version);
776 src.d_version = dst.d_version = e->e_version;
778 fsz = _libelf_fsize(ELF_T_SHDR, ec, e->e_version, (size_t) 1);
780 STAILQ_FOREACH(scn, &e->e_u.e_elf.e_scn, s_next) {
781 if (ec == ELFCLASS32)
782 src.d_buf = &scn->s_shdr.s_shdr32;
784 src.d_buf = &scn->s_shdr.s_shdr64;
787 dst.d_buf = newfile + rc + scn->s_ndx * fsz;
789 if (_libelf_xlate(&dst, &src, e->e_byteorder, ec,
794 rc += e->e_u.e_elf.e_nscn * fsz;
799 assert(rc == newsize);
802 * Write out the constructed contents and remap the file in
806 if (e->e_rawfile && munmap(e->e_rawfile, e->e_rawsize) < 0) {
807 LIBELF_SET_ERROR(IO, errno);
811 if (write(e->e_fd, newfile, (size_t) newsize) != newsize ||
812 lseek(e->e_fd, (off_t) 0, SEEK_SET) < 0) {
813 LIBELF_SET_ERROR(IO, errno);
817 if (e->e_cmd != ELF_C_WRITE) {
818 if ((e->e_rawfile = mmap(NULL, (size_t) newsize, PROT_READ,
819 MAP_PRIVATE, e->e_fd, (off_t) 0)) == MAP_FAILED) {
820 LIBELF_SET_ERROR(IO, errno);
823 e->e_rawsize = newsize;
827 * Reset flags, remove existing section descriptors and
828 * {E,P}HDR pointers so that a subsequent elf_get{e,p}hdr()
829 * and elf_getscn() will function correctly.
832 e->e_flags &= ~ELF_F_DIRTY;
834 STAILQ_FOREACH_SAFE(scn, &e->e_u.e_elf.e_scn, s_next, tscn)
835 _libelf_release_scn(scn);
837 if (ec == ELFCLASS32) {
838 free(e->e_u.e_elf.e_ehdr.e_ehdr32);
839 if (e->e_u.e_elf.e_phdr.e_phdr32)
840 free(e->e_u.e_elf.e_phdr.e_phdr32);
842 e->e_u.e_elf.e_ehdr.e_ehdr32 = NULL;
843 e->e_u.e_elf.e_phdr.e_phdr32 = NULL;
845 free(e->e_u.e_elf.e_ehdr.e_ehdr64);
846 if (e->e_u.e_elf.e_phdr.e_phdr64)
847 free(e->e_u.e_elf.e_phdr.e_phdr64);
849 e->e_u.e_elf.e_ehdr.e_ehdr64 = NULL;
850 e->e_u.e_elf.e_phdr.e_phdr64 = NULL;
864 elf_update(Elf *e, Elf_Cmd c)
871 if (e == NULL || e->e_kind != ELF_K_ELF ||
872 (c != ELF_C_NULL && c != ELF_C_WRITE)) {
873 LIBELF_SET_ERROR(ARGUMENT, 0);
877 if ((ec = e->e_class) != ELFCLASS32 && ec != ELFCLASS64) {
878 LIBELF_SET_ERROR(CLASS, 0);
882 if (e->e_version == EV_NONE)
883 e->e_version = EV_CURRENT;
885 if (c == ELF_C_WRITE && e->e_cmd == ELF_C_READ) {
886 LIBELF_SET_ERROR(MODE, 0);
890 if ((rc = _libelf_resync_elf(e)) < 0)
896 if (e->e_cmd == ELF_C_READ) {
898 * This descriptor was opened in read-only mode or by
902 LIBELF_SET_ERROR(MODE, 0);
904 LIBELF_SET_ERROR(ARGUMENT, 0);
909 LIBELF_SET_ERROR(SEQUENCE, 0);
913 return (_libelf_write_elf(e, rc));