8322 nl: misleading-indentation

[unleashed/tickless.git] / usr / src / cmd / sgs / libelf / common / update.c

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*
 *      Copyright (c) 1988 AT&T
 *        All Rights Reserved
 */

#include <memory.h>
#include <malloc.h>
#include <limits.h>

#include <sgs.h>
#include "decl.h"
#include "msg.h"

/*
 * This module is compiled twice, the second time having
 * -D_ELF64 defined.  The following set of macros, along
 * with machelf.h, represent the differences between the
 * two compilations.  Be careful *not* to add any class-
 * dependent code (anything that has elf32 or elf64 in the
 * name) to this code without hiding it behind a switch-
 * able macro like these.
 */
#if     defined(_ELF64)

#define FSZ_LONG        ELF64_FSZ_XWORD
#define ELFCLASS        ELFCLASS64
#define _elf_snode_init _elf64_snode_init
#define _elfxx_cookscn  _elf64_cookscn
#define _elf_upd_lib    _elf64_upd_lib
#define elf_fsize       elf64_fsize
#define _elf_entsz      _elf64_entsz
#define _elf_msize      _elf64_msize
#define _elf_upd_usr    _elf64_upd_usr
#define wrt             wrt64
#define elf_xlatetof    elf64_xlatetof
#define _elfxx_update   _elf64_update
#define _elfxx_swap_wrimage     _elf64_swap_wrimage

#else   /* ELF32 */

#define FSZ_LONG        ELF32_FSZ_WORD
#define ELFCLASS        ELFCLASS32
#define _elf_snode_init _elf32_snode_init
#define _elfxx_cookscn  _elf32_cookscn
#define _elf_upd_lib    _elf32_upd_lib
#define elf_fsize       elf32_fsize
#define _elf_entsz      _elf32_entsz
#define _elf_msize      _elf32_msize
#define _elf_upd_usr    _elf32_upd_usr
#define wrt             wrt32
#define elf_xlatetof    elf32_xlatetof
#define _elfxx_update   _elf32_update
#define _elfxx_swap_wrimage     _elf32_swap_wrimage

#endif /* ELF64 */


#if     !(defined(_LP64) && defined(_ELF64))
#define TEST_SIZE

/*
 * Handle the decision of whether the current linker can handle the
 * desired object size, and if not, which error to issue.
 *
 * Input is the desired size. On failure, an error has been issued
 * and 0 is returned. On success, 1 is returned.
 */
static int
test_size(Lword hi)
{
#ifndef _LP64                   /* 32-bit linker */
        /*
         * A 32-bit libelf is limited to a 2GB output file. This limit
         * is due to the fact that off_t is a signed value, and that
         * libelf cannot support large file support:
         *      - ABI reasons
         *      - Memory use generally is 2x output file size anyway,
         *              so lifting the file size limit will just send
         *              you crashing into the 32-bit VM limit.
         * If the output is an ELFCLASS64 object, or an ELFCLASS32 object
         * under 4GB, switching to the 64-bit version of libelf will help.
         * However, an ELFCLASS32 object must not exceed 4GB.
         */
        if (hi > INT_MAX) {     /* Bigger than 2GB */
#ifndef _ELF64
                /* ELFCLASS32 object is fundamentally too big? */
                if (hi > UINT_MAX) {
                        _elf_seterr(EFMT_FBIG_CLASS32, 0);
                        return (0);
                }
#endif                          /* _ELF64 */

                /* Should switch to the 64-bit libelf? */
                _elf_seterr(EFMT_FBIG_LARGEFILE, 0);
                return (0);
        }
#endif                          /* !_LP64 */


#if     defined(_LP64) && !defined(_ELF64)   /* 64-bit linker, ELFCLASS32 */
        /*
         * A 64-bit linker can produce any size output
         * file, but if the resulting file is ELFCLASS32,
         * it must not exceed 4GB.
         */
        if (hi > UINT_MAX) {
                _elf_seterr(EFMT_FBIG_CLASS32, 0);
                return (0);
        }
#endif

        return (1);
}
#endif                          /* TEST_SIZE */

/*
 * Output file update
 *      These functions walk an Elf structure, update its information,
 *      and optionally write the output file.  Because the application
 *      may control of the output file layout, two upd_... routines
 *      exist.  They're similar but too different to merge cleanly.
 *
 *      The library defines a "dirty" bit to force parts of the file
 *      to be written on update.  These routines ignore the dirty bit
 *      and do everything.  A minimal update routine might be useful
 *      someday.
 */

static size_t
_elf_upd_lib(Elf * elf)
{
        Lword           hi;
        Lword           hibit;
        Elf_Scn *       s;
        register Lword  sz;
        Ehdr *          eh = elf->ed_ehdr;
        unsigned        ver = eh->e_version;
        register char   *p = (char *)eh->e_ident;
        size_t          scncnt;

        /*
         * Ehdr and Phdr table go first
         */
        p[EI_MAG0] = ELFMAG0;
        p[EI_MAG1] = ELFMAG1;
        p[EI_MAG2] = ELFMAG2;
        p[EI_MAG3] = ELFMAG3;
        p[EI_CLASS] = ELFCLASS;
        /* LINTED */
        p[EI_VERSION] = (Byte)ver;
        hi = elf_fsize(ELF_T_EHDR, 1, ver);
        /* LINTED */
        eh->e_ehsize = (Half)hi;
        if (eh->e_phnum != 0) {
                /* LINTED */
                eh->e_phentsize = (Half)elf_fsize(ELF_T_PHDR, 1, ver);
                /* LINTED */
                eh->e_phoff = (Off)hi;
                hi += eh->e_phentsize * eh->e_phnum;
        } else {
                eh->e_phoff = 0;
                eh->e_phentsize = 0;
        }

        /*
         * Obtain the first section header.  Typically, this section has NULL
         * contents, however in the case of Extended ELF Sections this section
         * is used to hold an alternative e_shnum, e_shstrndx and e_phnum.
         * On initial allocation (see _elf_snode) the elements of this section
         * would have been zeroed.  The e_shnum is initialized later, after the
         * section header count has been determined.  The e_shstrndx and
         * e_phnum may have already been initialized by the caller (for example,
         * gelf_update_shdr() in mcs(1)).
         */
        if ((s = elf->ed_hdscn) == 0) {
                eh->e_shnum = 0;
                scncnt = 0;
        } else {
                s = s->s_next;
                scncnt = 1;
        }

        /*
         * Loop through sections.  Compute section size before changing hi.
         * Allow null buffers for NOBITS.
         */
        hibit = 0;
        for (; s != 0; s = s->s_next) {
                register Dnode  *d;
                register Lword  fsz, j;
                Shdr *sh = s->s_shdr;

                scncnt++;
                if (sh->sh_type == SHT_NULL) {
                        *sh = _elf_snode_init.sb_shdr;
                        continue;
                }

                if ((s->s_myflags & SF_READY) == 0)
                        (void) _elfxx_cookscn(s);

                sh->sh_addralign = 1;
                if ((sz = (Lword)_elf_entsz(elf, sh->sh_type, ver)) != 0)
                        /* LINTED */
                        sh->sh_entsize = (Half)sz;
                sz = 0;
                for (d = s->s_hdnode; d != 0; d = d->db_next) {
                        if ((fsz = elf_fsize(d->db_data.d_type,
                            1, ver)) == 0)
                                return (0);

                        j = _elf_msize(d->db_data.d_type, ver);
                        fsz *= (d->db_data.d_size / j);
                        d->db_osz = (size_t)fsz;
                        if ((j = d->db_data.d_align) > 1) {
                                if (j > sh->sh_addralign)
                                        sh->sh_addralign = (Xword)j;

                                if (sz % j != 0)
                                        sz += j - sz % j;
                        }
                        d->db_data.d_off = (off_t)sz;
                        d->db_xoff = sz;
                        sz += fsz;
                }

                sh->sh_size = (Xword) sz;
                /*
                 * We want to take into account the offsets for NOBITS
                 * sections and let the "sh_offsets" point to where
                 * the section would 'conceptually' fit within
                 * the file (as required by the ABI).
                 *
                 * But - we must also make sure that the NOBITS does
                 * not take up any actual space in the file.  We preserve
                 * the actual offset into the file in the 'hibit' variable.
                 * When we come to the first non-NOBITS section after a
                 * encountering a NOBITS section the hi counter is restored
                 * to its proper place in the file.
                 */
                if (sh->sh_type == SHT_NOBITS) {
                        if (hibit == 0)
                                hibit = hi;
                } else {
                        if (hibit) {
                                hi = hibit;
                                hibit = 0;
                        }
                }
                j = sh->sh_addralign;
                if ((fsz = hi % j) != 0)
                        hi += j - fsz;

                /* LINTED */
                sh->sh_offset = (Off)hi;
                hi += sz;
        }

        /*
         * if last section was a 'NOBITS' section then we need to
         * restore the 'hi' counter to point to the end of the last
         * non 'NOBITS' section.
         */
        if (hibit) {
                hi = hibit;
                hibit = 0;
        }

        /*
         * Shdr table last
         */
        if (scncnt != 0) {
                if (hi % FSZ_LONG != 0)
                        hi += FSZ_LONG - hi % FSZ_LONG;
                /* LINTED */
                eh->e_shoff = (Off)hi;
                /*
                 * If we are using 'extended sections' then the
                 * e_shnum is stored in the sh_size field of the
                 * first section header.
                 *
                 * NOTE: we set e_shnum to '0' because it's specified
                 * this way in the gABI, and in the hopes that
                 * this will cause less problems to unaware
                 * tools then if we'd set it to SHN_XINDEX (0xffff).
                 */
                if (scncnt < SHN_LORESERVE)
                        eh->e_shnum = scncnt;
                else {
                        Shdr    *sh;
                        sh = (Shdr *)elf->ed_hdscn->s_shdr;
                        sh->sh_size = scncnt;
                        eh->e_shnum = 0;
                }
                /* LINTED */
                eh->e_shentsize = (Half)elf_fsize(ELF_T_SHDR, 1, ver);
                hi += eh->e_shentsize * scncnt;
        } else {
                eh->e_shoff = 0;
                eh->e_shentsize = 0;
        }

#ifdef TEST_SIZE
        if (test_size(hi) == 0)
                return (0);
#endif

        return ((size_t)hi);
}



static size_t
_elf_upd_usr(Elf * elf)
{
        Lword           hi;
        Elf_Scn *       s;
        register Lword  sz;
        Ehdr *          eh = elf->ed_ehdr;
        unsigned        ver = eh->e_version;
        register char   *p = (char *)eh->e_ident;
        size_t          scncnt;

        /*
         * Ehdr and Phdr table go first
         */
        p[EI_MAG0] = ELFMAG0;
        p[EI_MAG1] = ELFMAG1;
        p[EI_MAG2] = ELFMAG2;
        p[EI_MAG3] = ELFMAG3;
        p[EI_CLASS] = ELFCLASS;
        /* LINTED */
        p[EI_VERSION] = (Byte)ver;
        hi = elf_fsize(ELF_T_EHDR, 1, ver);
        /* LINTED */
        eh->e_ehsize = (Half)hi;

        /*
         * If phnum is zero, phoff "should" be zero too,
         * but the application is responsible for it.
         * Allow a non-zero value here and update the
         * hi water mark accordingly.
         */

        if (eh->e_phnum != 0)
                /* LINTED */
                eh->e_phentsize = (Half)elf_fsize(ELF_T_PHDR, 1, ver);
        else
                eh->e_phentsize = 0;
        if ((sz = eh->e_phoff + eh->e_phentsize * eh->e_phnum) > hi)
                hi = sz;

        /*
         * Loop through sections, skipping index zero.
         * Compute section size before changing hi.
         * Allow null buffers for NOBITS.
         */

        if ((s = elf->ed_hdscn) == 0) {
                eh->e_shnum = 0;
                scncnt = 0;
        } else {
                scncnt = 1;
                s = s->s_next;
        }
        for (; s != 0; s = s->s_next) {
                register Dnode  *d;
                register Lword  fsz, j;
                Shdr *sh = s->s_shdr;

                if ((s->s_myflags & SF_READY) == 0)
                        (void) _elfxx_cookscn(s);

                ++scncnt;
                sz = 0;
                for (d = s->s_hdnode; d != 0; d = d->db_next) {
                        if ((fsz = elf_fsize(d->db_data.d_type, 1,
                            ver)) == 0)
                                return (0);
                        j = _elf_msize(d->db_data.d_type, ver);
                        fsz *= (d->db_data.d_size / j);
                        d->db_osz = (size_t)fsz;

                        if ((sh->sh_type != SHT_NOBITS) &&
                            ((j = (d->db_data.d_off + d->db_osz)) > sz))
                                sz = j;
                }
                if (sh->sh_size < sz) {
                        _elf_seterr(EFMT_SCNSZ, 0);
                        return (0);
                }
                if ((sh->sh_type != SHT_NOBITS) &&
                    (hi < sh->sh_offset + sh->sh_size))
                        hi = sh->sh_offset + sh->sh_size;
        }

        /*
         * Shdr table last.  Comment above for phnum/phoff applies here.
         */
        if (scncnt != 0) {
                /* LINTED */
                eh->e_shentsize = (Half)elf_fsize(ELF_T_SHDR, 1, ver);
                if (scncnt < SHN_LORESERVE) {
                        eh->e_shnum = scncnt;
                } else {
                        Shdr *sh;
                        sh = (Shdr *)elf->ed_hdscn->s_shdr;
                        sh->sh_size = scncnt;
                        eh->e_shnum = 0;
                }
        } else {
                eh->e_shentsize = 0;
        }

        if ((sz = eh->e_shoff + eh->e_shentsize * scncnt) > hi)
                hi = sz;

#ifdef TEST_SIZE
        if (test_size(hi) == 0)
                return (0);
#endif

        return ((size_t)hi);
}


static size_t
wrt(Elf * elf, Xword outsz, unsigned fill, int update_cmd)
{
        Elf_Data                dst, src;
        unsigned                flag;
        Xword                   hi, sz;
        char                    *image;
        Elf_Scn                 *s;
        Ehdr                    *eh = elf->ed_ehdr;
        unsigned                ver = eh->e_version;
        unsigned                encode;
        int                     byte;
        _elf_execfill_func_t    *execfill_func;

        /*
         * If this is an ELF_C_WRIMAGE write, then we encode into the
         * byte order of the system we are running on rather than that of
         * of the object. For ld.so.1, this is the same order, but
         * for 'ld', it might not be in the case where we are cross
         * linking an object for a different target. In this later case,
         * the linker-host byte order is necessary so that the linker can
         * manipulate the resulting  image. It is expected that the linker
         * will call elf_swap_wrimage() if necessary to convert the image
         * to the target byte order.
         */
        encode = (update_cmd == ELF_C_WRIMAGE) ? _elf_sys_encoding() :
            eh->e_ident[EI_DATA];

        /*
         * Two issues can cause trouble for the output file.
         * First, begin() with ELF_C_RDWR opens a file for both
         * read and write.  On the write update(), the library
         * has to read everything it needs before truncating
         * the file.  Second, using mmap for both read and write
         * is too tricky.  Consequently, the library disables mmap
         * on the read side.  Using mmap for the output saves swap
         * space, because that mapping is SHARED, not PRIVATE.
         *
         * If the file is write-only, there can be nothing of
         * interest to bother with.
         *
         * The following reads the entire file, which might be
         * more than necessary.  Better safe than sorry.
         */

        if ((elf->ed_myflags & EDF_READ) &&
            (_elf_vm(elf, (size_t)0, elf->ed_fsz) != OK_YES))
                return (0);

        flag = elf->ed_myflags & EDF_WRALLOC;
        if ((image = _elf_outmap(elf->ed_fd, outsz, &flag)) == 0)
                return (0);

        if (flag == 0)
                elf->ed_myflags |= EDF_IMALLOC;

        /*
         * If an error occurs below, a "dirty" bit may be cleared
         * improperly.  To save a second pass through the file,
         * this code sets the dirty bit on the elf descriptor
         * when an error happens, assuming that will "cover" any
         * accidents.
         */

        /*
         * Hi is needed only when 'fill' is non-zero.
         * Fill is non-zero only when the library
         * calculates file/section/data buffer offsets.
         * The lib guarantees they increase monotonically.
         * That guarantees proper filling below.
         */


        /*
         * Ehdr first
         */

        src.d_buf = (Elf_Void *)eh;
        src.d_type = ELF_T_EHDR;
        src.d_size = sizeof (Ehdr);
        src.d_version = EV_CURRENT;
        dst.d_buf = (Elf_Void *)image;
        dst.d_size = eh->e_ehsize;
        dst.d_version = ver;
        if (elf_xlatetof(&dst, &src, encode) == 0)
                return (0);
        elf->ed_ehflags &= ~ELF_F_DIRTY;
        hi = eh->e_ehsize;

        /*
         * Phdr table if one exists
         */

        if (eh->e_phnum != 0) {
                unsigned        work;
                /*
                 * Unlike other library data, phdr table is
                 * in the user version.  Change src buffer
                 * version here, fix it after translation.
                 */

                src.d_buf = (Elf_Void *)elf->ed_phdr;
                src.d_type = ELF_T_PHDR;
                src.d_size = elf->ed_phdrsz;
                ELFACCESSDATA(work, _elf_work)
                src.d_version = work;
                dst.d_buf = (Elf_Void *)(image + eh->e_phoff);
                dst.d_size = eh->e_phnum * eh->e_phentsize;
                hi = (Xword)(eh->e_phoff + dst.d_size);
                if (elf_xlatetof(&dst, &src, encode) == 0) {
                        elf->ed_uflags |= ELF_F_DIRTY;
                        return (0);
                }
                elf->ed_phflags &= ~ELF_F_DIRTY;
                src.d_version = EV_CURRENT;
        }

        /*
         * Loop through sections
         */

        ELFACCESSDATA(byte, _elf_byte);
        ELFACCESSDATA(execfill_func, _elf_execfill_func);
        for (s = elf->ed_hdscn; s != 0; s = s->s_next) {
                register Dnode  *d, *prevd;
                Xword           off = 0;
                Shdr            *sh = s->s_shdr;
                char            *start = image + sh->sh_offset;
                char            *here;
                _elf_execfill_func_t    *execfill;

                /* Only use the execfill function on SHF_EXECINSTR sections */
                execfill = (sh->sh_flags & SHF_EXECINSTR) ?
                    execfill_func : NULL;

                /*
                 * Just "clean" DIRTY flag for "empty" sections.  Even if
                 * NOBITS needs padding, the next thing in the
                 * file will provide it.  (And if this NOBITS is
                 * the last thing in the file, no padding needed.)
                 */
                if ((sh->sh_type == SHT_NOBITS) ||
                    (sh->sh_type == SHT_NULL)) {
                        d = s->s_hdnode, prevd = 0;
                        for (; d != 0; prevd = d, d = d->db_next)
                                d->db_uflags &= ~ELF_F_DIRTY;
                        continue;
                }
                /*
                 * Clear out the memory between the end of the last
                 * section and the begining of this section.
                 */
                if (fill && (sh->sh_offset > hi)) {
                        sz = sh->sh_offset - hi;
                        (void) memset(start - sz, byte, sz);
                }


                for (d = s->s_hdnode, prevd = 0;
                    d != 0; prevd = d, d = d->db_next) {
                        d->db_uflags &= ~ELF_F_DIRTY;
                        here = start + d->db_data.d_off;

                        /*
                         * Clear out the memory between the end of the
                         * last update and the start of this data buffer.
                         *
                         * These buffers represent input sections that have
                         * been concatenated into an output section, so if
                         * the output section is executable (SHF_EXECINSTR)
                         * and a fill function has been registered, use the
                         * function. Otherwise, use the fill byte.
                         */
                        if (fill && (d->db_data.d_off > off)) {
                                sz = (Xword)(d->db_data.d_off - off);
                                if (execfill != NULL)
                                        (* execfill)(start,
                                            here - start - sz, sz);
                                else
                                        (void) memset(here - sz, byte, sz);
                        }

                        if ((d->db_myflags & DBF_READY) == 0) {
                                SCNLOCK(s);
                                if (_elf_locked_getdata(s, &prevd->db_data) !=
                                    &d->db_data) {
                                        elf->ed_uflags |= ELF_F_DIRTY;
                                        SCNUNLOCK(s);
                                        return (0);
                                }
                                SCNUNLOCK(s);
                        }
                        dst.d_buf = (Elf_Void *)here;
                        dst.d_size = d->db_osz;

                        /*
                         * Copy the translated bits out to the destination
                         * image.
                         */
                        if (elf_xlatetof(&dst, &d->db_data, encode) == 0) {
                                elf->ed_uflags |= ELF_F_DIRTY;
                                return (0);
                        }

                        off = (Xword)(d->db_data.d_off + dst.d_size);
                }
                hi = sh->sh_offset + sh->sh_size;
        }

        /*
         * Shdr table last
         */

        if (fill && (eh->e_shoff > hi)) {
                sz = eh->e_shoff - hi;
                (void) memset(image + hi, byte, sz);
        }

        src.d_type = ELF_T_SHDR;
        src.d_size = sizeof (Shdr);
        dst.d_buf = (Elf_Void *)(image + eh->e_shoff);
        dst.d_size = eh->e_shentsize;
        for (s = elf->ed_hdscn; s != 0; s = s->s_next) {
                assert((uintptr_t)dst.d_buf < ((uintptr_t)image + outsz));
                s->s_shflags &= ~ELF_F_DIRTY;
                s->s_uflags &= ~ELF_F_DIRTY;
                src.d_buf = s->s_shdr;

                if (elf_xlatetof(&dst, &src, encode) == 0) {
                        elf->ed_uflags |= ELF_F_DIRTY;
                        return (0);
                }

                dst.d_buf = (char *)dst.d_buf + eh->e_shentsize;
        }
        /*
         * ELF_C_WRIMAGE signifyes that we build the memory image, but
         * that we do not actually write it to disk.  This is used
         * by ld(1) to build up a full image of an elf file and then
         * to process the file before it's actually written out to
         * disk.  This saves ld(1) the overhead of having to write
         * the image out to disk twice.
         */
        if (update_cmd == ELF_C_WRIMAGE) {
                elf->ed_uflags &= ~ELF_F_DIRTY;
                elf->ed_wrimage = image;
                elf->ed_wrimagesz = outsz;
                return (outsz);
        }

        if (_elf_outsync(elf->ed_fd, image, outsz,
            ((elf->ed_myflags & EDF_IMALLOC) ? 0 : 1)) != 0) {
                elf->ed_uflags &= ~ELF_F_DIRTY;
                elf->ed_myflags &= ~EDF_IMALLOC;
                return (outsz);
        }

        elf->ed_uflags |= ELF_F_DIRTY;
        return (0);
}




/*
 * The following is a private interface between the linkers (ld & ld.so.1)
 * and libelf:
 *
 * elf_update(elf, ELF_C_WRIMAGE)
 *      This will cause full image representing the elf file
 *      described by the elf pointer to be built in memory.  If the
 *      elf pointer has a valid file descriptor associated with it
 *      we will attempt to build the memory image from mmap()'ed
 *      storage.  If the elf descriptor does not have a valid
 *      file descriptor (opened with elf_begin(0, ELF_C_IMAGE, 0))
 *      then the image will be allocated from dynamic memory (malloc()).
 *
 *      elf_update() will return the size of the memory image built
 *      when sucessful.
 *
 *      When a subsequent call to elf_update() with ELF_C_WRITE as
 *      the command is performed it will sync the image created
 *      by ELF_C_WRIMAGE to disk (if fd available) and
 *      free the memory allocated.
 */

off_t
_elfxx_update(Elf * elf, Elf_Cmd cmd)
{
        size_t          sz;
        unsigned        u;
        Ehdr            *eh = elf->ed_ehdr;

        if (elf == 0)
                return (-1);

        ELFWLOCK(elf)
        switch (cmd) {
        default:
                _elf_seterr(EREQ_UPDATE, 0);
                ELFUNLOCK(elf)
                return (-1);

        case ELF_C_WRIMAGE:
                if ((elf->ed_myflags & EDF_WRITE) == 0) {
                        _elf_seterr(EREQ_UPDWRT, 0);
                        ELFUNLOCK(elf)
                        return (-1);
                }
                break;
        case ELF_C_WRITE:
                if ((elf->ed_myflags & EDF_WRITE) == 0) {
                        _elf_seterr(EREQ_UPDWRT, 0);
                        ELFUNLOCK(elf)
                        return (-1);
                }
                if (elf->ed_wrimage) {
                        if (elf->ed_myflags & EDF_WRALLOC) {
                                free(elf->ed_wrimage);
                                /*
                                 * The size is still returned even
                                 * though nothing is actually written
                                 * out.  This is just to be consistant
                                 * with the rest of the interface.
                                 */
                                sz = elf->ed_wrimagesz;
                                elf->ed_wrimage = 0;
                                elf->ed_wrimagesz = 0;
                                ELFUNLOCK(elf);
                                return ((off_t)sz);
                        }
                        sz = _elf_outsync(elf->ed_fd, elf->ed_wrimage,
                            elf->ed_wrimagesz,
                            (elf->ed_myflags & EDF_IMALLOC ? 0 : 1));
                        elf->ed_myflags &= ~EDF_IMALLOC;
                        elf->ed_wrimage = 0;
                        elf->ed_wrimagesz = 0;
                        ELFUNLOCK(elf);
                        return ((off_t)sz);
                }
                /* FALLTHROUGH */
        case ELF_C_NULL:
                break;
        }

        if (eh == 0) {
                _elf_seterr(ESEQ_EHDR, 0);
                ELFUNLOCK(elf)
                return (-1);
        }

        if ((u = eh->e_version) > EV_CURRENT) {
                _elf_seterr(EREQ_VER, 0);
                ELFUNLOCK(elf)
                return (-1);
        }

        if (u == EV_NONE)
                eh->e_version = EV_CURRENT;

        if ((u = eh->e_ident[EI_DATA]) == ELFDATANONE) {
                unsigned        encode;

                ELFACCESSDATA(encode, _elf_encode)
                if (encode == ELFDATANONE) {
                        _elf_seterr(EREQ_ENCODE, 0);
                        ELFUNLOCK(elf)
                        return (-1);
                }
                /* LINTED */
                eh->e_ident[EI_DATA] = (Byte)encode;
        }

        u = 1;
        if (elf->ed_uflags & ELF_F_LAYOUT) {
                sz = _elf_upd_usr(elf);
                u = 0;
        } else
                sz = _elf_upd_lib(elf);

        if ((sz != 0) && ((cmd == ELF_C_WRITE) || (cmd == ELF_C_WRIMAGE)))
                sz = wrt(elf, (Xword)sz, u, cmd);

        if (sz == 0) {
                ELFUNLOCK(elf)
                return (-1);
        }

        ELFUNLOCK(elf)
        return ((off_t)sz);
}


/*
 * When wrt() processes an ELF_C_WRIMAGE request, the resulting image
 * gets the byte order (encoding) of the platform running the linker
 * rather than that of the target host. This allows the linker to modify
 * the image, prior to flushing it to the output file. This routine
 * is used to re-translate such an image into the byte order of the
 * target host.
 */
int
_elfxx_swap_wrimage(Elf *elf)
{
        Elf_Data        dst, src;
        Elf_Scn         *s;
        Ehdr            *eh;
        Half            e_phnum;
        unsigned        ver;
        unsigned        encode;

        /*
         * Ehdr first
         */

        ELFWLOCK(elf);
        eh = elf->ed_ehdr;
        e_phnum = eh->e_phnum;
        ver = eh->e_version;
        encode = eh->e_ident[EI_DATA];

        src.d_buf = dst.d_buf = (Elf_Void *)eh;
        src.d_type = dst.d_type = ELF_T_EHDR;
        src.d_size = dst.d_size = sizeof (Ehdr);
        src.d_version = dst.d_version = ver;
        if (elf_xlatetof(&dst, &src, encode) == 0) {
                ELFUNLOCK(elf);
                return (1);
        }

        /*
         * Phdr table if one exists
         */

        if (e_phnum != 0) {
                unsigned        work;
                /*
                 * Unlike other library data, phdr table is
                 * in the user version.
                 */

                src.d_buf = dst.d_buf = (Elf_Void *)elf->ed_phdr;
                src.d_type = dst.d_type = ELF_T_PHDR;
                src.d_size = dst.d_size = elf->ed_phdrsz;
                ELFACCESSDATA(work, _elf_work)
                src.d_version = dst.d_version = work;
                if (elf_xlatetof(&dst, &src, encode) == 0) {
                        ELFUNLOCK(elf);
                        return (1);
                }
        }

        /*
         * Loop through sections
         */

        for (s = elf->ed_hdscn; s != 0; s = s->s_next) {
                register Dnode  *d, *prevd;
                Shdr            *sh = s->s_shdr;

                if ((sh->sh_type == SHT_NOBITS) || (sh->sh_type == SHT_NULL))
                        continue;

                for (d = s->s_hdnode, prevd = 0;
                    d != 0; prevd = d, d = d->db_next) {

                        if ((d->db_myflags & DBF_READY) == 0) {
                                SCNLOCK(s);
                                if (_elf_locked_getdata(s, &prevd->db_data) !=
                                    &d->db_data) {
                                        SCNUNLOCK(s);
                                        ELFUNLOCK(elf);
                                        return (1);
                                }
                                SCNUNLOCK(s);
                        }

                        dst = d->db_data;
                        if (elf_xlatetof(&dst, &d->db_data, encode) == 0) {
                                ELFUNLOCK(elf);
                                return (1);
                        }
                }
        }

        /*
         * Shdr table
         */

        src.d_type = dst.d_type = ELF_T_SHDR;
        src.d_version = dst.d_version = ver;
        for (s = elf->ed_hdscn; s != 0; s = s->s_next) {
                src.d_buf = dst.d_buf = s->s_shdr;
                src.d_size = dst.d_size = sizeof (Shdr);
                if (elf_xlatetof(&dst, &src, encode) == 0) {
                        ELFUNLOCK(elf);
                        return (1);
                }
        }

        ELFUNLOCK(elf);
        return (0);
}



#ifndef _ELF64
/* class-independent, only needs to be compiled once */

off_t
elf_update(Elf *elf, Elf_Cmd cmd)
{
        if (elf == 0)
                return (-1);

        if (elf->ed_class == ELFCLASS32)
                return (_elf32_update(elf, cmd));
        else if (elf->ed_class == ELFCLASS64) {
                return (_elf64_update(elf, cmd));
        }

        _elf_seterr(EREQ_CLASS, 0);
        return (-1);
}

int
_elf_swap_wrimage(Elf *elf)
{
        if (elf == 0)
                return (0);

        if (elf->ed_class == ELFCLASS32)
                return (_elf32_swap_wrimage(elf));

        if (elf->ed_class == ELFCLASS64)
                return (_elf64_swap_wrimage(elf));

        _elf_seterr(EREQ_CLASS, 0);
        return (0);
}

/*
 * 4106312, 4106398, This is an ad-hoc means for the 32-bit
 * Elf64 version of libld.so.3 to get around the limitation
 * of a 32-bit d_off field.  This is only intended to be
 * used by libld to relocate symbols in large NOBITS sections.
 */
Elf64_Off
_elf_getxoff(Elf_Data * d)
{
        return (((Dnode *)d)->db_xoff);
}
#endif /* !_ELF64 */