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-rw-r--r--ext/libelf/elf_update.c885
1 files changed, 885 insertions, 0 deletions
diff --git a/ext/libelf/elf_update.c b/ext/libelf/elf_update.c
new file mode 100644
index 000000000..6959d3c3e
--- /dev/null
+++ b/ext/libelf/elf_update.c
@@ -0,0 +1,885 @@
+/*-
+ * Copyright (c) 2006 Joseph Koshy
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+
+#include <sys/mman.h>
+#include <sys/param.h>
+#ifdef __sun
+#include <sys/sysmacros.h>
+#endif
+
+#include <assert.h>
+#include <errno.h>
+#include "gelf.h"
+#include "libelf.h"
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "_libelf.h"
+
+/*
+ * Update the internal data structures associated with an ELF object.
+ * Returns the size in bytes the ELF object would occupy in its file
+ * representation.
+ *
+ * After a successful call to this function, the following structures
+ * are updated:
+ *
+ * - The ELF header is updated.
+ * - All sections are sorted in order of ascending addresses and their
+ * section header table entries updated. An error is signalled
+ * if an overlap was detected among sections.
+ * - All data descriptors associated with a section are sorted in order
+ * of ascending addresses. Overlaps, if detected, are signalled as
+ * errors. Other sanity checks for alignments, section types etc. are
+ * made.
+ *
+ * After a resync_elf() successfully returns, the ELF descriptor is
+ * ready for being handed over to _libelf_write_elf().
+ *
+ * File alignments:
+ * PHDR - Addr
+ * SHDR - Addr
+ *
+ * XXX: how do we handle 'flags'.
+ */
+
+/*
+ * Compute the extents of a section, by looking at the.
+ */
+static int
+_libelf_compute_section_extents(Elf *e, Elf_Scn *s, off_t *rc)
+{
+ int ec;
+ Elf_Data *d, *td;
+ unsigned int elftype;
+ uint32_t sh_type;
+ uint64_t d_align;
+ uint64_t sh_align, sh_entsize, sh_offset, sh_size;
+ uint64_t scn_size, scn_alignment;
+
+ /*
+ * We need to recompute library private data structures if one
+ * or more of the following is true:
+ * - The underlying Shdr structure has been marked `dirty'. Significant
+ * fields include: `sh_offset', `sh_type', `sh_size', `sh_addralign'.
+ * - The Elf_Data structures part of this section have been marked
+ * `dirty'. Affected members include `d_align', `d_offset', `d_type',
+ * and `d_size'.
+ * - The section as a whole is `dirty', e.g., it has been allocated
+ * using elf_newscn(), or if a new Elf_Data structure was added using
+ * elf_newdata().
+ *
+ * Each of these conditions would result in the ELF_F_DIRTY bit being
+ * set on the section descriptor's `s_flags' field.
+ */
+
+ ec = e->e_class;
+
+ if (ec == ELFCLASS32) {
+ sh_type = s->s_shdr.s_shdr32.sh_type;
+ sh_align = (uint64_t) s->s_shdr.s_shdr32.sh_addralign;
+ sh_entsize = (uint64_t) s->s_shdr.s_shdr32.sh_entsize;
+ sh_offset = (uint64_t) s->s_shdr.s_shdr32.sh_offset;
+ sh_size = (uint64_t) s->s_shdr.s_shdr32.sh_size;
+ } else {
+ sh_type = s->s_shdr.s_shdr64.sh_type;
+ sh_align = s->s_shdr.s_shdr64.sh_addralign;
+ sh_entsize = s->s_shdr.s_shdr64.sh_entsize;
+ sh_offset = s->s_shdr.s_shdr64.sh_offset;
+ sh_size = s->s_shdr.s_shdr64.sh_size;
+ }
+
+ if (sh_type == SHT_NULL || sh_type == SHT_NOBITS)
+ return (1);
+
+ if ((s->s_flags & ELF_F_DIRTY) == 0) {
+ if ((size_t) *rc < sh_offset + sh_size)
+ *rc = sh_offset + sh_size;
+ return (1);
+ }
+
+ elftype = _libelf_xlate_shtype(sh_type);
+ if (elftype > ELF_T_LAST) {
+ LIBELF_SET_ERROR(SECTION, 0);
+ return (0);
+ }
+
+ /*
+ * Compute the extent of the data descriptors associated with
+ * this section.
+ */
+ scn_alignment = 0;
+ if (sh_align == 0)
+ sh_align = _libelf_falign(elftype, ec);
+
+ /* Compute the section alignment. */
+ STAILQ_FOREACH(d, &s->s_data, d_next) {
+ if (d->d_type != elftype) {
+ LIBELF_SET_ERROR(DATA, 0);
+ return (0);
+ }
+ if (d->d_version != e->e_version) {
+ LIBELF_SET_ERROR(VERSION, 0);
+ return (0);
+ }
+ if ((d_align = d->d_align) % sh_align) {
+ LIBELF_SET_ERROR(LAYOUT, 0);
+ return (0);
+ }
+ if (d_align == 0 || (d_align & (d_align - 1))) {
+ LIBELF_SET_ERROR(DATA, 0);
+ return (0);
+ }
+ if (d_align > scn_alignment)
+ scn_alignment = d_align;
+ }
+
+ scn_size = 0L;
+
+ STAILQ_FOREACH_SAFE(d, &s->s_data, d_next, td) {
+ if (e->e_flags & ELF_F_LAYOUT) {
+ if ((uint64_t) d->d_off + d->d_size > scn_size)
+ scn_size = d->d_off + d->d_size;
+ } else {
+ scn_size = roundup(scn_size, scn_alignment);
+ d->d_off = scn_size;
+ scn_size += d->d_size;
+ }
+ }
+
+ /*
+ * If the application is requesting full control over the layout
+ * of the section, check its values for sanity.
+ */
+ if (e->e_flags & ELF_F_LAYOUT) {
+ if (scn_alignment > sh_align || sh_offset % sh_align ||
+ sh_size < scn_size) {
+ LIBELF_SET_ERROR(LAYOUT, 0);
+ return (0);
+ }
+ } else {
+ /*
+ * Otherwise compute the values in the section header.
+ */
+
+ if (scn_alignment > sh_align)
+ sh_align = scn_alignment;
+
+ /*
+ * If the section entry size is zero, try and fill in an
+ * appropriate entry size. Per the elf(5) manual page
+ * sections without fixed-size entries should have their
+ * 'sh_entsize' field set to zero.
+ */
+ if (sh_entsize == 0 &&
+ (sh_entsize = _libelf_fsize(elftype, ec, e->e_version,
+ (size_t) 1)) == 1)
+ sh_entsize = 0;
+
+ sh_size = scn_size;
+ sh_offset = roundup(*rc, sh_align);
+
+ if (ec == ELFCLASS32) {
+ s->s_shdr.s_shdr32.sh_addralign = (uint32_t) sh_align;
+ s->s_shdr.s_shdr32.sh_entsize = (uint32_t) sh_entsize;
+ s->s_shdr.s_shdr32.sh_offset = (uint32_t) sh_offset;
+ s->s_shdr.s_shdr32.sh_size = (uint32_t) sh_size;
+ } else {
+ s->s_shdr.s_shdr64.sh_addralign = sh_align;
+ s->s_shdr.s_shdr64.sh_entsize = sh_entsize;
+ s->s_shdr.s_shdr64.sh_offset = sh_offset;
+ s->s_shdr.s_shdr64.sh_size = sh_size;
+ }
+ }
+
+ if ((size_t) *rc < sh_offset + sh_size)
+ *rc = sh_offset + sh_size;
+
+ s->s_size = sh_size;
+ s->s_offset = sh_offset;
+ return (1);
+}
+
+
+/*
+ * Insert a section in ascending order in the list
+ */
+
+static int
+_libelf_insert_section(Elf *e, Elf_Scn *s)
+{
+ Elf_Scn *t, *prevt;
+ uint64_t smax, smin, tmax, tmin;
+
+ smin = s->s_offset;
+ smax = smin + s->s_size;
+
+ prevt = NULL;
+ STAILQ_FOREACH(t, &e->e_u.e_elf.e_scn, s_next) {
+ tmin = t->s_offset;
+ tmax = tmin + t->s_size;
+
+ /* check if there is an overlap */
+ if (tmax < smin) {
+ prevt = t;
+ continue;
+ } else if (smax < tmin)
+ break;
+ else {
+ LIBELF_SET_ERROR(LAYOUT, 0);
+ return (0);
+ }
+ }
+
+ if (prevt)
+ STAILQ_INSERT_AFTER(&e->e_u.e_elf.e_scn, prevt, s, s_next);
+ else
+ STAILQ_INSERT_HEAD(&e->e_u.e_elf.e_scn, s, s_next);
+ return (1);
+}
+
+static off_t
+_libelf_resync_sections(Elf *e, off_t rc)
+{
+ int ec;
+ off_t nrc;
+ size_t sh_type;
+ Elf_Scn *s, *ts;
+
+ ec = e->e_class;
+
+ /*
+ * Make a pass through sections, computing the extent of each
+ * section. Order in increasing order of addresses.
+ */
+
+ nrc = rc;
+ STAILQ_FOREACH(s, &e->e_u.e_elf.e_scn, s_next)
+ if (_libelf_compute_section_extents(e, s, &nrc) == 0)
+ return ((off_t) -1);
+
+ STAILQ_FOREACH_SAFE(s, &e->e_u.e_elf.e_scn, s_next, ts) {
+ if (ec == ELFCLASS32)
+ sh_type = s->s_shdr.s_shdr32.sh_type;
+ else
+ sh_type = s->s_shdr.s_shdr64.sh_type;
+
+ /* XXX Do we need the 'size' field of an SHT_NOBITS section */
+ if (sh_type == SHT_NOBITS || sh_type == SHT_NULL)
+ continue;
+
+ if (s->s_offset < (uint64_t) rc) {
+ if (s->s_offset + s->s_size < (uint64_t) rc) {
+ /*
+ * Try insert this section in the
+ * correct place in the list,
+ * detecting overlaps if any.
+ */
+ STAILQ_REMOVE(&e->e_u.e_elf.e_scn, s, _Elf_Scn,
+ s_next);
+ if (_libelf_insert_section(e, s) == 0)
+ return ((off_t) -1);
+ } else {
+ LIBELF_SET_ERROR(LAYOUT, 0);
+ return ((off_t) -1);
+ }
+ } else
+ rc = s->s_offset + s->s_size;
+ }
+
+ assert(nrc == rc);
+
+ return (rc);
+}
+
+static off_t
+_libelf_resync_elf(Elf *e)
+{
+ int ec, eh_class, eh_type;
+ unsigned int eh_byteorder, eh_version;
+ size_t align, fsz;
+ size_t phnum, shnum;
+ off_t rc, phoff, shoff;
+ void *ehdr;
+ Elf32_Ehdr *eh32;
+ Elf64_Ehdr *eh64;
+
+ rc = 0;
+
+ ec = e->e_class;
+
+ assert(ec == ELFCLASS32 || ec == ELFCLASS64);
+
+ /*
+ * Prepare the EHDR.
+ */
+ if ((ehdr = _libelf_ehdr(e, ec, 0)) == NULL)
+ return ((off_t) -1);
+
+ eh32 = ehdr;
+ eh64 = ehdr;
+
+ if (ec == ELFCLASS32) {
+ eh_byteorder = eh32->e_ident[EI_DATA];
+ eh_class = eh32->e_ident[EI_CLASS];
+ phoff = (uint64_t) eh32->e_phoff;
+ shoff = (uint64_t) eh32->e_shoff;
+ eh_type = eh32->e_type;
+ eh_version = eh32->e_version;
+ } else {
+ eh_byteorder = eh64->e_ident[EI_DATA];
+ eh_class = eh64->e_ident[EI_CLASS];
+ phoff = eh64->e_phoff;
+ shoff = eh64->e_shoff;
+ eh_type = eh64->e_type;
+ eh_version = eh64->e_version;
+ }
+
+ if (eh_version == EV_NONE)
+ eh_version = EV_CURRENT;
+
+ if (eh_version != e->e_version) { /* always EV_CURRENT */
+ LIBELF_SET_ERROR(VERSION, 0);
+ return ((off_t) -1);
+ }
+
+ if (eh_class != e->e_class) {
+ LIBELF_SET_ERROR(CLASS, 0);
+ return ((off_t) -1);
+ }
+
+ if (e->e_cmd != ELF_C_WRITE && eh_byteorder != e->e_byteorder) {
+ LIBELF_SET_ERROR(HEADER, 0);
+ return ((off_t) -1);
+ }
+
+ shnum = e->e_u.e_elf.e_nscn;
+ phnum = e->e_u.e_elf.e_nphdr;
+
+ e->e_byteorder = eh_byteorder;
+
+#define INITIALIZE_EHDR(E,EC,V) do { \
+ (E)->e_ident[EI_MAG0] = ELFMAG0; \
+ (E)->e_ident[EI_MAG1] = ELFMAG1; \
+ (E)->e_ident[EI_MAG2] = ELFMAG2; \
+ (E)->e_ident[EI_MAG3] = ELFMAG3; \
+ (E)->e_ident[EI_CLASS] = (EC); \
+ (E)->e_ident[EI_VERSION] = (V); \
+ (E)->e_ehsize = _libelf_fsize(ELF_T_EHDR, (EC), (V), \
+ (size_t) 1); \
+ (E)->e_phentsize = _libelf_fsize(ELF_T_PHDR, (EC), (V), \
+ (size_t) 1); \
+ (E)->e_shentsize = _libelf_fsize(ELF_T_SHDR, (EC), (V), \
+ (size_t) 1); \
+ } while (0)
+
+ if (ec == ELFCLASS32)
+ INITIALIZE_EHDR(eh32, ec, eh_version);
+ else
+ INITIALIZE_EHDR(eh64, ec, eh_version);
+
+ (void) elf_flagehdr(e, ELF_C_SET, ELF_F_DIRTY);
+
+ rc += _libelf_fsize(ELF_T_EHDR, ec, eh_version, (size_t) 1);
+
+ /*
+ * Compute the layout the program header table, if one is
+ * present. The program header table needs to be aligned to a
+ * `natural' boundary.
+ */
+ if (phnum) {
+ fsz = _libelf_fsize(ELF_T_PHDR, ec, eh_version, phnum);
+ align = _libelf_falign(ELF_T_PHDR, ec);
+
+ if (e->e_flags & ELF_F_LAYOUT) {
+ /*
+ * Check offsets for sanity.
+ */
+ if (rc > phoff) {
+ LIBELF_SET_ERROR(HEADER, 0);
+ return ((off_t) -1);
+ }
+
+ if (phoff % align) {
+ LIBELF_SET_ERROR(LAYOUT, 0);
+ return ((off_t) -1);
+ }
+
+ } else
+ phoff = roundup(rc, align);
+
+ rc = phoff + fsz;
+ } else
+ phoff = 0;
+
+ /*
+ * Compute the layout of the sections associated with the
+ * file.
+ */
+
+ if ((rc = _libelf_resync_sections(e, rc)) < 0)
+ return ((off_t) -1);
+
+ /*
+ * Compute the space taken up by the section header table, if
+ * one is needed.
+ */
+ if (shnum) {
+ fsz = _libelf_fsize(ELF_T_SHDR, ec, eh_version, (size_t) 1);
+ align = _libelf_falign(ELF_T_SHDR, ec);
+
+ if (e->e_flags & ELF_F_LAYOUT) {
+ if (rc > shoff) {
+ LIBELF_SET_ERROR(HEADER, 0);
+ return ((off_t) -1);
+ }
+
+ if (shoff % align) {
+ LIBELF_SET_ERROR(LAYOUT, 0);
+ return ((off_t) -1);
+ }
+ } else
+ shoff = roundup(rc, align);
+
+ rc = shoff + fsz * shnum;
+ } else
+ shoff = 0;
+
+ /*
+ * Set the fields of the Executable Header that could potentially use
+ * extended numbering.
+ */
+ _libelf_setphnum(e, ehdr, ec, phnum);
+ _libelf_setshnum(e, ehdr, ec, shnum);
+
+ /*
+ * Update the `e_phoff' and `e_shoff' fields if the library is
+ * doing the layout.
+ */
+ if ((e->e_flags & ELF_F_LAYOUT) == 0) {
+ if (ec == ELFCLASS32) {
+ eh32->e_phoff = (uint32_t) phoff;
+ eh32->e_shoff = (uint32_t) shoff;
+ } else {
+ eh64->e_phoff = (uint64_t) phoff;
+ eh64->e_shoff = (uint64_t) shoff;
+ }
+ }
+
+ return (rc);
+}
+
+/*
+ * Write out the contents of a section.
+ */
+
+static off_t
+_libelf_write_scn(Elf *e, char *nf, Elf_Scn *s, off_t rc)
+{
+ int ec;
+ size_t fsz, msz, nobjects;
+ uint32_t sh_type;
+ uint64_t sh_off;
+ int elftype;
+ Elf_Data *d, dst;
+
+ if ((ec = e->e_class) == ELFCLASS32)
+ sh_type = s->s_shdr.s_shdr32.sh_type;
+ else
+ sh_type = s->s_shdr.s_shdr64.sh_type;
+
+ /*
+ * Ignore sections that do not allocate space in the file.
+ */
+ if (sh_type == SHT_NOBITS || sh_type == SHT_NULL)
+ return (rc);
+
+
+ elftype = _libelf_xlate_shtype(sh_type);
+ assert(elftype >= ELF_T_FIRST && elftype <= ELF_T_LAST);
+
+ msz = _libelf_msize(elftype, ec, e->e_version);
+
+ sh_off = s->s_offset;
+ assert(sh_off % _libelf_falign(elftype, ec) == 0);
+
+ /*
+ * If the section has a `rawdata' descriptor, and the section
+ * contents have not been modified, use its contents directly.
+ * The `s_rawoff' member contains the offset into the original
+ * file, while `s_offset' contains its new location in the
+ * destination.
+ */
+
+ if (STAILQ_EMPTY(&s->s_data)) {
+
+ if ((d = elf_rawdata(s, NULL)) == NULL)
+ return ((off_t) -1);
+
+ STAILQ_FOREACH(d, &s->s_rawdata, d_next) {
+ if ((uint64_t) rc < sh_off + d->d_off)
+ (void) memset(nf + rc,
+ LIBELF_PRIVATE(fillchar), sh_off +
+ d->d_off - rc);
+ rc = sh_off + d->d_off;
+
+ assert(d->d_buf != NULL);
+ assert(d->d_type == ELF_T_BYTE);
+ assert(d->d_version == e->e_version);
+
+ (void) memcpy(nf + rc,
+ e->e_rawfile + s->s_rawoff + d->d_off, d->d_size);
+
+ rc += d->d_size;
+ }
+
+ return (rc);
+ }
+
+ /*
+ * Iterate over the set of data descriptors for this section.
+ * The prior call to _libelf_resync_elf() would have setup the
+ * descriptors for this step.
+ */
+
+ dst.d_version = e->e_version;
+
+ STAILQ_FOREACH(d, &s->s_data, d_next) {
+
+ if ((uint64_t) rc < sh_off + d->d_off)
+ (void) memset(nf + rc,
+ LIBELF_PRIVATE(fillchar), sh_off + d->d_off - rc);
+
+ rc = sh_off + d->d_off;
+
+ assert(d->d_buf != NULL);
+ assert(d->d_type == (Elf_Type) elftype);
+ assert(d->d_version == e->e_version);
+ assert(d->d_size % msz == 0);
+
+ nobjects = d->d_size / msz;
+
+ fsz = _libelf_fsize(elftype, ec, e->e_version, nobjects);
+
+ dst.d_buf = nf + rc;
+ dst.d_size = fsz;
+
+ if (_libelf_xlate(&dst, d, e->e_byteorder, ec, ELF_TOFILE) ==
+ NULL)
+ return ((off_t) -1);
+
+ rc += fsz;
+ }
+
+ return ((off_t) rc);
+}
+
+/*
+ * Write out the file image.
+ *
+ * The original file could have been mapped in with an ELF_C_RDWR
+ * command and the application could have added new content or
+ * re-arranged its sections before calling elf_update(). Consequently
+ * its not safe to work `in place' on the original file. So we
+ * malloc() the required space for the updated ELF object and build
+ * the object there and write it out to the underlying file at the
+ * end. Note that the application may have opened the underlying file
+ * in ELF_C_RDWR and only retrieved/modified a few sections. We take
+ * care to avoid translating file sections unnecessarily.
+ *
+ * Gaps in the coverage of the file by the file's sections will be
+ * filled with the fill character set by elf_fill(3).
+ */
+
+static off_t
+_libelf_write_elf(Elf *e, off_t newsize)
+{
+ int ec;
+ off_t rc;
+ size_t fsz, msz, phnum, shnum;
+ uint64_t phoff, shoff;
+ void *ehdr;
+ char *newfile;
+ Elf_Data dst, src;
+ Elf_Scn *scn, *tscn;
+ Elf32_Ehdr *eh32;
+ Elf64_Ehdr *eh64;
+
+ assert(e->e_kind == ELF_K_ELF);
+ assert(e->e_cmd != ELF_C_READ);
+ assert(e->e_fd >= 0);
+
+ if ((newfile = malloc((size_t) newsize)) == NULL) {
+ LIBELF_SET_ERROR(RESOURCE, errno);
+ return ((off_t) -1);
+ }
+
+ ec = e->e_class;
+
+ ehdr = _libelf_ehdr(e, ec, 0);
+ assert(ehdr != NULL);
+
+ phnum = e->e_u.e_elf.e_nphdr;
+
+ if (ec == ELFCLASS32) {
+ eh32 = (Elf32_Ehdr *) ehdr;
+
+ phoff = (uint64_t) eh32->e_phoff;
+ shnum = eh32->e_shnum;
+ shoff = (uint64_t) eh32->e_shoff;
+ } else {
+ eh64 = (Elf64_Ehdr *) ehdr;
+
+ phoff = eh64->e_phoff;
+ shnum = eh64->e_shnum;
+ shoff = eh64->e_shoff;
+ }
+
+ fsz = _libelf_fsize(ELF_T_EHDR, ec, e->e_version, (size_t) 1);
+ msz = _libelf_msize(ELF_T_EHDR, ec, e->e_version);
+
+ (void) memset(&dst, 0, sizeof(dst));
+ (void) memset(&src, 0, sizeof(src));
+
+ src.d_buf = ehdr;
+ src.d_size = msz;
+ src.d_type = ELF_T_EHDR;
+ src.d_version = dst.d_version = e->e_version;
+
+ rc = 0;
+
+ dst.d_buf = newfile + rc;
+ dst.d_size = fsz;
+
+ if (_libelf_xlate(&dst, &src, e->e_byteorder, ec, ELF_TOFILE) ==
+ NULL)
+ goto error;
+
+ rc += fsz;
+
+ /*
+ * Write the program header table if present.
+ */
+
+ if (phnum != 0 && phoff != 0) {
+ assert((unsigned) rc <= phoff);
+
+ fsz = _libelf_fsize(ELF_T_PHDR, ec, e->e_version, phnum);
+
+ assert(phoff % _libelf_falign(ELF_T_PHDR, ec) == 0);
+ assert(fsz > 0);
+
+ src.d_version = dst.d_version = e->e_version;
+ src.d_type = ELF_T_PHDR;
+
+ if (ec == ELFCLASS32)
+ src.d_buf = e->e_u.e_elf.e_phdr.e_phdr32;
+ else
+ src.d_buf = e->e_u.e_elf.e_phdr.e_phdr64;
+
+ src.d_size = phnum * _libelf_msize(ELF_T_PHDR, ec,
+ e->e_version);
+
+ dst.d_size = fsz;
+
+ if ((uint64_t) rc < phoff)
+ (void) memset(newfile + rc,
+ LIBELF_PRIVATE(fillchar), phoff - rc);
+
+ dst.d_buf = newfile + rc;
+
+ if (_libelf_xlate(&dst, &src, e->e_byteorder, ec, ELF_TOFILE) ==
+ NULL)
+ goto error;
+
+ rc = phoff + fsz;
+ }
+
+ /*
+ * Write out individual sections.
+ */
+
+ STAILQ_FOREACH(scn, &e->e_u.e_elf.e_scn, s_next)
+ if ((rc = _libelf_write_scn(e, newfile, scn, rc)) < 0)
+ goto error;
+
+ /*
+ * Write out the section header table, if required.
+ */
+
+ if (shnum != 0 && shoff != 0) {
+ assert((unsigned) rc <= shoff);
+
+ if ((uint64_t) rc < shoff)
+ (void) memset(newfile + rc,
+ LIBELF_PRIVATE(fillchar), shoff - rc);
+
+ rc = shoff;
+
+ assert(rc % _libelf_falign(ELF_T_SHDR, ec) == 0);
+
+ src.d_type = ELF_T_SHDR;
+ src.d_size = _libelf_msize(ELF_T_SHDR, ec, e->e_version);
+ src.d_version = dst.d_version = e->e_version;
+
+ fsz = _libelf_fsize(ELF_T_SHDR, ec, e->e_version, (size_t) 1);
+
+ STAILQ_FOREACH(scn, &e->e_u.e_elf.e_scn, s_next) {
+ if (ec == ELFCLASS32)
+ src.d_buf = &scn->s_shdr.s_shdr32;
+ else
+ src.d_buf = &scn->s_shdr.s_shdr64;
+
+ dst.d_size = fsz;
+ dst.d_buf = newfile + rc;
+
+ if (_libelf_xlate(&dst, &src, e->e_byteorder, ec,
+ ELF_TOFILE) != &dst)
+ goto error;
+
+ rc += fsz;
+ }
+ }
+
+ /*
+ */
+
+ assert(rc == newsize);
+
+ /*
+ * Write out the constructed contents and remap the file in
+ * read-only.
+ */
+
+ if (e->e_rawfile && munmap(e->e_rawfile, e->e_rawsize) < 0) {
+ LIBELF_SET_ERROR(IO, errno);
+ goto error;
+ }
+
+ if (write(e->e_fd, newfile, (size_t) newsize) != newsize ||
+ lseek(e->e_fd, (off_t) 0, SEEK_SET) < 0) {
+ LIBELF_SET_ERROR(IO, errno);
+ goto error;
+ }
+
+ if (e->e_cmd != ELF_C_WRITE) {
+ if ((e->e_rawfile = mmap(NULL, (size_t) newsize, PROT_READ,
+ MAP_PRIVATE, e->e_fd, (off_t) 0)) == MAP_FAILED) {
+ LIBELF_SET_ERROR(IO, errno);
+ goto error;
+ }
+ e->e_rawsize = newsize;
+ }
+
+ /*
+ * Reset flags, remove existing section descriptors and
+ * {E,P}HDR pointers so that a subsequent elf_get{e,p}hdr()
+ * and elf_getscn() will function correctly.
+ */
+
+ e->e_flags &= ~ELF_F_DIRTY;
+
+ STAILQ_FOREACH_SAFE(scn, &e->e_u.e_elf.e_scn, s_next, tscn)
+ _libelf_release_scn(scn);
+
+ if (ec == ELFCLASS32) {
+ free(e->e_u.e_elf.e_ehdr.e_ehdr32);
+ if (e->e_u.e_elf.e_phdr.e_phdr32)
+ free(e->e_u.e_elf.e_phdr.e_phdr32);
+
+ e->e_u.e_elf.e_ehdr.e_ehdr32 = NULL;
+ e->e_u.e_elf.e_phdr.e_phdr32 = NULL;
+ } else {
+ free(e->e_u.e_elf.e_ehdr.e_ehdr64);
+ if (e->e_u.e_elf.e_phdr.e_phdr64)
+ free(e->e_u.e_elf.e_phdr.e_phdr64);
+
+ e->e_u.e_elf.e_ehdr.e_ehdr64 = NULL;
+ e->e_u.e_elf.e_phdr.e_phdr64 = NULL;
+ }
+
+ return (rc);
+
+ error:
+ if (newfile)
+ free(newfile);
+ return ((off_t) -1);
+}
+
+off_t
+elf_update(Elf *e, Elf_Cmd c)
+{
+ int ec;
+ off_t rc;
+
+ rc = (off_t) -1;
+
+ if (e == NULL || e->e_kind != ELF_K_ELF ||
+ (c != ELF_C_NULL && c != ELF_C_WRITE)) {
+ LIBELF_SET_ERROR(ARGUMENT, 0);
+ return (rc);
+ }
+
+ if ((ec = e->e_class) != ELFCLASS32 && ec != ELFCLASS64) {
+ LIBELF_SET_ERROR(CLASS, 0);
+ return (rc);
+ }
+
+ if (e->e_version == EV_NONE)
+ e->e_version = EV_CURRENT;
+
+ if (c == ELF_C_WRITE && e->e_cmd == ELF_C_READ) {
+ LIBELF_SET_ERROR(MODE, 0);
+ return (rc);
+ }
+
+ if ((rc = _libelf_resync_elf(e)) < 0)
+ return (rc);
+
+ if (c == ELF_C_NULL)
+ return (rc);
+
+ if (e->e_cmd == ELF_C_READ) {
+ /*
+ * This descriptor was opened in read-only mode or by
+ * elf_memory().
+ */
+ if (e->e_fd)
+ LIBELF_SET_ERROR(MODE, 0);
+ else
+ LIBELF_SET_ERROR(ARGUMENT, 0);
+ return ((off_t) -1);
+ }
+
+ if (e->e_fd < 0) {
+ LIBELF_SET_ERROR(SEQUENCE, 0);
+ return ((off_t) -1);
+ }
+
+ return (_libelf_write_elf(e, rc));
+}