Merge commit '281819e5f8b19cd8627541a22d261906fd190276' into merges

[unleashed.git] / usr / src / cmd / sgs / libld / common / version.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 (c) 1993, 2010, Oracle and/or its affiliates. All rights reserved.
 */

#include        <string.h>
#include        <stdio.h>
#include        <debug.h>
#include        "msg.h"
#include        "_libld.h"

/*
 * Locate a version descriptor.
 */
Ver_desc *
ld_vers_find(const char *name, Word hash, APlist *alp)
{
        Aliste          idx;
        Ver_desc        *vdp;

        for (APLIST_TRAVERSE(alp, idx, vdp)) {
                if (vdp->vd_hash != hash)
                        continue;
                if (strcmp(vdp->vd_name, name) == 0)
                        return (vdp);
        }
        return (NULL);
}

/*
 * Add a new version descriptor to a version descriptor list.  Note, users of
 * this are responsible for determining if the version descriptor already
 * exists (this can reduce the need to allocate storage for descriptor names
 * until it is determined a descriptor need be created (see map_symbol())).
 */
Ver_desc *
ld_vers_desc(const char *name, Word hash, APlist **alpp)
{
        Ver_desc        *vdp;

        if ((vdp = libld_calloc(sizeof (Ver_desc), 1)) == NULL)
                return ((Ver_desc *)S_ERROR);

        vdp->vd_name = name;
        vdp->vd_hash = hash;

        if (aplist_append(alpp, vdp, AL_CNT_VERDESCS) == NULL)
                return ((Ver_desc *)S_ERROR);

        return (vdp);
}

/*
 * Now that all explict files have been processed validate any version
 * definitions.  Insure that any version references are available (a version
 * has been defined when it's been assigned an index).  Also calculate the
 * number of .version section entries that will be required to hold this
 * information.
 */
#define _NUM_OF_VERS_   40      /* twice as big as the depth for libc version */
typedef struct {
        Ver_desc        **ver_stk;
        int             ver_sp;
        int             ver_lmt;
} Ver_Stack;

static uintptr_t
vers_visit_children(Ofl_desc *ofl, Ver_desc *vp, int flag)
{
        Aliste                  idx;
        Ver_desc                *vdp;
        static int              err = 0;
        static Ver_Stack        ver_stk = {0, 0, 0};
        int                     tmp_sp;

        /*
         * If there was any fatal error,
         * just return.
         */
        if (err == S_ERROR)
                return (err);

        /*
         * if this is called from, ver_check_defs(), initialize sp.
         */
        if (flag == 0)
                ver_stk.ver_sp = 0;

        /*
         * Check if passed version pointer vp is already in the stack.
         */
        for (tmp_sp = 0; tmp_sp < ver_stk.ver_sp; tmp_sp++) {
                Ver_desc *v;

                v = ver_stk.ver_stk[tmp_sp];
                if (v == vp) {
                        /*
                         * cyclic dependency.
                         */
                        if (err == 0) {
                                ld_eprintf(ofl, ERR_FATAL,
                                    MSG_INTL(MSG_VER_CYCLIC));
                                err = 1;
                        }
                        for (tmp_sp = 0; tmp_sp < ver_stk.ver_sp; tmp_sp++) {
                                v = ver_stk.ver_stk[tmp_sp];
                                if ((v->vd_flags & FLG_VER_CYCLIC) == 0) {
                                        v->vd_flags |= FLG_VER_CYCLIC;
                                        ld_eprintf(ofl, ERR_NONE,
                                            MSG_INTL(MSG_VER_ADDVER),
                                            v->vd_name);
                                }
                        }
                        if ((vp->vd_flags & FLG_VER_CYCLIC) == 0) {
                                vp->vd_flags |= FLG_VER_CYCLIC;
                                ld_eprintf(ofl, ERR_NONE,
                                    MSG_INTL(MSG_VER_ADDVER), vp->vd_name);
                        }
                        return (err);
                }
        }

        /*
         * Push version on the stack.
         */
        if (ver_stk.ver_sp >= ver_stk.ver_lmt) {
                ver_stk.ver_lmt += _NUM_OF_VERS_;
                if ((ver_stk.ver_stk = (Ver_desc **)
                    libld_realloc((void *)ver_stk.ver_stk,
                    ver_stk.ver_lmt * sizeof (Ver_desc *))) == NULL)
                        return (S_ERROR);
        }
        ver_stk.ver_stk[(ver_stk.ver_sp)++] = vp;

        /*
         * Now visit children.
         */
        for (APLIST_TRAVERSE(vp->vd_deps, idx, vdp))
                if (vers_visit_children(ofl, vdp, 1) == S_ERROR)
                        return (S_ERROR);

        /*
         * Pop version from the stack.
         */
        (ver_stk.ver_sp)--;

        return (err);
}

uintptr_t
ld_vers_check_defs(Ofl_desc *ofl)
{
        Aliste          idx1;
        Ver_desc        *vdp;
        uintptr_t       is_cyclic = 0;

        DBG_CALL(Dbg_ver_def_title(ofl->ofl_lml, ofl->ofl_name));

        /*
         * First check if there are any cyclic dependency
         */
        for (APLIST_TRAVERSE(ofl->ofl_verdesc, idx1, vdp))
                if ((is_cyclic = vers_visit_children(ofl, vdp, 0)) == S_ERROR)
                        return (S_ERROR);

        if (is_cyclic)
                ofl->ofl_flags |= FLG_OF_FATAL;

        for (APLIST_TRAVERSE(ofl->ofl_verdesc, idx1, vdp)) {
                Byte            cnt;
                Sym             *sym;
                Sym_desc        *sdp;
                const char      *name = vdp->vd_name;
                uchar_t         bind;
                Ver_desc        *_vdp __unused;
                avl_index_t     where;
                Aliste          idx2;

                if (vdp->vd_ndx == 0) {
                        ld_eprintf(ofl, ERR_FATAL,
                            MSG_INTL(MSG_VER_UNDEF), name, vdp->vd_ref->vd_name,
                            vdp->vd_ref->vd_file->ifl_name);
                        continue;
                }

                DBG_CALL(Dbg_ver_desc_entry(ofl->ofl_lml, vdp));

                /*
                 * If a version definition contains no symbols this is possibly
                 * a mapfile error.
                 */
                if ((vdp->vd_flags &
                    (VER_FLG_BASE | VER_FLG_WEAK | FLG_VER_REFER)) == 0)
                        DBG_CALL(Dbg_ver_nointerface(ofl->ofl_lml,
                            vdp->vd_name));

                /*
                 * Update the version entry count to account for this new
                 * version descriptor (the count is the size in bytes).
                 */
                ofl->ofl_verdefsz += sizeof (Verdef);

                /*
                 * Traverse this versions dependency list to determine what
                 * additional version dependencies we must account for against
                 * this descriptor.
                 */
                cnt = 1;
                for (APLIST_TRAVERSE(vdp->vd_deps, idx2, _vdp)) {
                        cnt++;
                }
                ofl->ofl_verdefsz += (cnt * sizeof (Verdaux));

                /*
                 * Except for the base version descriptor, generate an absolute
                 * symbol to reflect this version.
                 */
                if (vdp->vd_flags & VER_FLG_BASE)
                        continue;

                if (vdp->vd_flags & VER_FLG_WEAK)
                        bind = STB_WEAK;
                else
                        bind = STB_GLOBAL;

                if (sdp = ld_sym_find(name, vdp->vd_hash, &where, ofl)) {
                        /*
                         * If the symbol already exists and is undefined or was
                         * defined in a shared library, convert it to an
                         * absolute.
                         */
                        if ((sdp->sd_sym->st_shndx == SHN_UNDEF) ||
                            (sdp->sd_ref != REF_REL_NEED)) {
                                sdp->sd_shndx = sdp->sd_sym->st_shndx = SHN_ABS;
                                sdp->sd_sym->st_info =
                                    ELF_ST_INFO(bind, STT_OBJECT);
                                sdp->sd_ref = REF_REL_NEED;
                                sdp->sd_flags |= (FLG_SY_SPECSEC |
                                    FLG_SY_DEFAULT | FLG_SY_EXPDEF);
                                sdp->sd_aux->sa_overndx = vdp->vd_ndx;

                                /*
                                 * If the reference originated from a mapfile
                                 * insure we mark the symbol as used.
                                 */
                                if (sdp->sd_flags & FLG_SY_MAPREF)
                                        sdp->sd_flags |= FLG_SY_MAPUSED;

                        } else if ((sdp->sd_flags & FLG_SY_SPECSEC) &&
                            (sdp->sd_sym->st_shndx != SHN_ABS) &&
                            (sdp->sd_ref == REF_REL_NEED)) {
                                ld_eprintf(ofl, ERR_WARNING,
                                    MSG_INTL(MSG_VER_DEFINED), name,
                                    sdp->sd_file->ifl_name);
                        }
                } else {
                        /*
                         * If the symbol does not exist create it.
                         */
                        if ((sym = libld_calloc(sizeof (Sym), 1)) == NULL)
                                return (S_ERROR);

                        sym->st_shndx = SHN_ABS;
                        sym->st_info = ELF_ST_INFO(bind, STT_OBJECT);
                        DBG_CALL(Dbg_ver_symbol(ofl->ofl_lml, name));

                        if ((sdp = ld_sym_enter(name, sym, vdp->vd_hash,
                            vdp->vd_file, ofl, 0, SHN_ABS,
                            (FLG_SY_SPECSEC | FLG_SY_DEFAULT | FLG_SY_EXPDEF),
                            &where)) == (Sym_desc *)S_ERROR)
                                return (S_ERROR);

                        sdp->sd_ref = REF_REL_NEED;
                        sdp->sd_aux->sa_overndx = vdp->vd_ndx;
                }
        }
        return (1);
}

/*
 * Dereference dependencies as a part of normalizing (allows recursion).
 */
static void
vers_derefer(Ifl_desc *ifl, Ver_desc *vdp, int weak)
{
        Aliste          idx;
        Ver_desc        *_vdp;
        Ver_index       *vip = &ifl->ifl_verndx[vdp->vd_ndx];

        /*
         * Set the INFO bit on all dependencies that ld.so.1
         * can skip verification for. These are the dependencies
         * that are inherited by others -- verifying the inheriting
         * version implicitily covers this one.
         *
         * If the head of the list was a weak then we only mark
         * weak dependencies, but if the head of the list was 'strong'
         * we set INFO on all dependencies.
         */
        if ((weak && (vdp->vd_flags & VER_FLG_WEAK)) || (!weak))
                vip->vi_flags |= VER_FLG_INFO;

        for (APLIST_TRAVERSE(vdp->vd_deps, idx, _vdp))
                vers_derefer(ifl, _vdp, weak);
}

/*
 * If we need to record the versions of any needed dependencies traverse the
 * shared object dependency list and calculate what version needed entries are
 * required.
 */
uintptr_t
ld_vers_check_need(Ofl_desc *ofl)
{
        Aliste          idx1;
        Ifl_desc        *ifl;
        Half            needndx;
        Str_tbl         *strtbl;


        /*
         * Determine which string table is appropriate.
         */
        strtbl = (OFL_IS_STATIC_OBJ(ofl)) ? ofl->ofl_strtab :
            ofl->ofl_dynstrtab;

        /*
         * Versym indexes for needed versions start with the next
         * available version after the final definied version.
         * However, it can never be less than 2. 0 is always for local
         * scope, and 1 is always the first global definition.
         */
        needndx = (ofl->ofl_vercnt > 0) ? (ofl->ofl_vercnt + 1) : 2;

        /*
         * Traverse the shared object list looking for dependencies.
         */
        for (APLIST_TRAVERSE(ofl->ofl_sos, idx1, ifl)) {
                Aliste          idx2;
                Ver_index       *vip;
                Ver_desc        *vdp;
                Byte            cnt, need = 0;

                if (!(ifl->ifl_flags & FLG_IF_NEEDED))
                        continue;

                if (ifl->ifl_vercnt <= VER_NDX_GLOBAL)
                        continue;

                /*
                 * Scan the version index list and if any weak version
                 * definition has been referenced by the user promote the
                 * dependency to be non-weak.  Weak version dependencies do not
                 * cause fatal errors from the runtime linker, non-weak
                 * dependencies do.
                 */
                for (cnt = 0; cnt <= ifl->ifl_vercnt; cnt++) {
                        vip = &ifl->ifl_verndx[cnt];
                        vdp = vip->vi_desc;

                        if ((vip->vi_flags & (FLG_VER_REFER | VER_FLG_WEAK)) ==
                            (FLG_VER_REFER | VER_FLG_WEAK))
                                vdp->vd_flags &= ~VER_FLG_WEAK;

                        /*
                         * Mark any weak reference as referred to so as to
                         * simplify normalization and later version dependency
                         * manipulation.
                         */
                        if (vip->vi_flags & VER_FLG_WEAK)
                                vip->vi_flags |= FLG_VER_REFER;
                }

                /*
                 * Scan the version dependency list to normalize the referenced
                 * dependencies.  Any needed version that is inherited by
                 * another like version is dereferenced as it is not necessary
                 * to make this part of the version dependencies.
                 */
                for (APLIST_TRAVERSE(ifl->ifl_verdesc, idx2, vdp)) {
                        Aliste          idx3;
                        Ver_desc        *_vdp;
                        int             type;

                        vip = &ifl->ifl_verndx[vdp->vd_ndx];

                        if (!(vip->vi_flags & FLG_VER_REFER))
                                continue;

                        type = vdp->vd_flags & VER_FLG_WEAK;
                        for (APLIST_TRAVERSE(vdp->vd_deps, idx3, _vdp))
                                vers_derefer(ifl, _vdp, type);
                }

                /*
                 * Finally, determine how many of the version dependencies need
                 * to be recorded.
                 */
                for (cnt = 0; cnt <= ifl->ifl_vercnt; cnt++) {
                        vip = &ifl->ifl_verndx[cnt];

                        /*
                         * If a version has been referenced then record it as a
                         * version dependency.
                         */
                        if (vip->vi_flags & FLG_VER_REFER) {
                                /* Assign a VERSYM index for it */
                                vip->vi_overndx = needndx++;

                                ofl->ofl_verneedsz += sizeof (Vernaux);
                                if (st_insert(strtbl, vip->vi_name) == -1)
                                        return (S_ERROR);
                                need++;
                        }
                }

                if (need) {
                        ifl->ifl_flags |= FLG_IF_VERNEED;
                        ofl->ofl_verneedsz += sizeof (Verneed);
                        if (st_insert(strtbl, ifl->ifl_soname) == -1)
                                return (S_ERROR);
                }
        }

        /*
         * If no version needed information is required unset the output file
         * flag.
         */
        if (ofl->ofl_verneedsz == 0)
                ofl->ofl_flags &= ~FLG_OF_VERNEED;

        return (1);
}

/*
 * Indicate dependency selection (allows recursion).
 */
static void
vers_select(Ofl_desc *ofl, Ifl_desc *ifl, Ver_desc *vdp, const char *ref)
{
        Aliste          idx;
        Ver_desc        *_vdp;
        Ver_index       *vip = &ifl->ifl_verndx[vdp->vd_ndx];

        vip->vi_flags |= FLG_VER_AVAIL;
        DBG_CALL(Dbg_ver_avail_entry(ofl->ofl_lml, vip, ref));

        for (APLIST_TRAVERSE(vdp->vd_deps, idx, _vdp))
                vers_select(ofl, ifl, _vdp, ref);
}

static Ver_index *
vers_index(Ofl_desc *ofl, Ifl_desc *ifl, int avail)
{
        Aliste          idx1;
        Ver_desc        *vdp;
        Ver_index       *vip;
        Sdf_desc        *sdf = ifl->ifl_sdfdesc;
        Word            count = ifl->ifl_vercnt;
        Sdv_desc        *sdv;

        /*
         * Allocate an index array large enough to hold all of the files
         * version descriptors.
         */
        if ((vip = libld_calloc(sizeof (Ver_index), (count + 1))) == NULL)
                return ((Ver_index *)S_ERROR);

        for (APLIST_TRAVERSE(ifl->ifl_verdesc, idx1, vdp)) {
                int     ndx = vdp->vd_ndx;

                vip[ndx].vi_name = vdp->vd_name;
                vip[ndx].vi_desc = vdp;

                /*
                 * Any relocatable object versions, and the `base' version are
                 * always available.
                 */
                if (avail || (vdp->vd_flags & VER_FLG_BASE))
                        vip[ndx].vi_flags |= FLG_VER_AVAIL;

                /*
                 * If this is a weak version mark it as such.  Weak versions
                 * are always dragged into any version dependencies created,
                 * and if a weak version is referenced it will be promoted to
                 * a non-weak version dependency.
                 */
                if (vdp->vd_flags & VER_FLG_WEAK)
                        vip[ndx].vi_flags |= VER_FLG_WEAK;
                /*
                 * If this version is mentioned in a mapfile using ADDVERS
                 * syntax then check to see if it corresponds to an actual
                 * version in the file.
                 */
                if (sdf && (sdf->sdf_flags & FLG_SDF_ADDVER)) {
                        Aliste  idx2;

                        for (ALIST_TRAVERSE(sdf->sdf_verneed, idx2, sdv)) {
                                if (strcmp(vip[ndx].vi_name, sdv->sdv_name))
                                        continue;

                                vip[ndx].vi_flags |= FLG_VER_REFER;
                                sdv->sdv_flags |= FLG_SDV_MATCHED;
                                break;
                        }
                }
        }

        /*
         * if $ADDVER was specified for this object verify that
         * all of it's dependent upon versions were refered to.
         */
        if (sdf && (sdf->sdf_flags & FLG_SDF_ADDVER)) {
                int     fail = 0;

                for (ALIST_TRAVERSE(sdf->sdf_verneed, idx1, sdv)) {
                        if (sdv->sdv_flags & FLG_SDV_MATCHED)
                                continue;

                        if (fail++ == 0) {
                                ld_eprintf(ofl, ERR_NONE,
                                    MSG_INTL(MSG_VER_ADDVERS), sdf->sdf_rfile,
                                    sdf->sdf_name);
                        }
                        ld_eprintf(ofl, ERR_NONE, MSG_INTL(MSG_VER_ADDVER),
                            sdv->sdv_name);
                }
                if (fail)
                        return ((Ver_index *)S_ERROR);
        }

        return (vip);
}

/*
 * Process a version symbol index section.
 */
int
ld_vers_sym_process(Ofl_desc *ofl, Is_desc *isp, Ifl_desc *ifl)
{
        Shdr    *symshdr;
        Shdr    *vershdr = isp->is_shdr;

        /*
         * Verify that the versym is the same size as the linked symbol table.
         * If these two get out of sync the file is considered corrupted.
         */
        symshdr = ifl->ifl_isdesc[vershdr->sh_link]->is_shdr;
        if ((symshdr->sh_size / symshdr->sh_entsize) != (vershdr->sh_size /
            vershdr->sh_entsize)) {
                Is_desc *sym_isp = ifl->ifl_isdesc[vershdr->sh_link];

                ld_eprintf(ofl, ERR_WARNING, MSG_INTL(MSG_ELF_VERSYM),
                    ifl->ifl_name, EC_WORD(isp->is_scnndx), isp->is_name,
                    EC_WORD(vershdr->sh_size / vershdr->sh_entsize),
                    EC_WORD(sym_isp->is_scnndx), sym_isp->is_name,
                    EC_WORD(symshdr->sh_size / symshdr->sh_entsize));
                return (1);
        }
        ifl->ifl_versym = (Versym *)isp->is_indata->d_buf;
        return (1);
}

/*
 * Process a version definition section from an input file.  A list of version
 * descriptors is created and associated with the input files descriptor.  If
 * this is a shared object these descriptors will be used to indicate the
 * availability of each version.  If this is a relocatable object then these
 * descriptors will be promoted (concatenated) to the output files image.
 */
uintptr_t
ld_vers_def_process(Is_desc *isp, Ifl_desc *ifl, Ofl_desc *ofl)
{
        const char      *str, *file = ifl->ifl_name;
        Sdf_desc        *sdf = ifl->ifl_sdfdesc;
        Sdv_desc        *sdv;
        Word            num, _num;
        Verdef          *vdf;
        int             relobj;

        /*
         * If there is no version section then simply indicate that all version
         * definitions asked for do not exist.
         */
        if (isp == NULL) {
                Aliste  idx;

                for (ALIST_TRAVERSE(sdf->sdf_vers, idx, sdv)) {
                        ld_eprintf(ofl, ERR_FATAL,
                            MSG_INTL(MSG_VER_NOEXIST), ifl->ifl_name,
                            sdv->sdv_name, sdv->sdv_ref);
                }
                return (0);
        }

        vdf = (Verdef *)isp->is_indata->d_buf;

        /*
         * Verify the version revision.  We only check the first version
         * structure as it is assumed all other version structures in this
         * data section will be of the same revision.
         */
        if (vdf->vd_version > VER_DEF_CURRENT)
                ld_eprintf(ofl, ERR_WARNING, MSG_INTL(MSG_VER_HIGHER),
                    ifl->ifl_name, vdf->vd_version, VER_DEF_CURRENT);


        num = isp->is_shdr->sh_info;
        str = (char *)ifl->ifl_isdesc[isp->is_shdr->sh_link]->is_indata->d_buf;

        if (ifl->ifl_ehdr->e_type == ET_REL)
                relobj = 1;
        else
                relobj = 0;

        DBG_CALL(Dbg_ver_def_title(ofl->ofl_lml, file));

        /*
         * Loop through the version information setting up a version descriptor
         * for each version definition.
         */
        for (_num = 1; _num <= num; _num++,
            vdf = (Verdef *)((uintptr_t)vdf + vdf->vd_next)) {
                const char      *name;
                Ver_desc        *ivdp, *ovdp = NULL;
                Word            hash;
                Half            cnt = vdf->vd_cnt;
                Half            ndx = vdf->vd_ndx;
                Verdaux         *vdap = (Verdaux *)((uintptr_t)vdf +
                    vdf->vd_aux);

                /*
                 * Keep track of the largest index for use in creating a
                 * version index array later, and create a version descriptor.
                 */
                if (ndx > ifl->ifl_vercnt)
                        ifl->ifl_vercnt = ndx;

                name = (char *)(str + vdap->vda_name);
                /* LINTED */
                hash = (Word)elf_hash(name);
                if (((ivdp = ld_vers_find(name, hash,
                    ifl->ifl_verdesc)) == NULL) &&
                    ((ivdp = ld_vers_desc(name, hash,
                    &ifl->ifl_verdesc)) == (Ver_desc *)S_ERROR))
                        return (S_ERROR);

                ivdp->vd_ndx = ndx;
                ivdp->vd_file = ifl;
                ivdp->vd_flags = vdf->vd_flags;

                /*
                 * If we're processing a relocatable object then this version
                 * definition needs to be propagated to the output file.
                 * Generate a new output file version and associated this input
                 * version to it.  During symbol processing the version index of
                 * the symbol will be promoted from the input file to the output
                 * files version definition.
                 */
                if (relobj) {
                        if (!(ofl->ofl_flags & FLG_OF_RELOBJ))
                                ofl->ofl_flags |= FLG_OF_PROCRED;

                        if ((ivdp->vd_flags & VER_FLG_BASE) == 0) {
                                /*
                                 * If no version descriptors have yet been set
                                 * up, initialize a base version to represent
                                 * the output file itself.  This `base' version
                                 * catches any internally generated symbols
                                 * (_end, _etext, etc.) and
                                 * serves to initialize the output version
                                 * descriptor count.
                                 */
                                if (ofl->ofl_vercnt == 0) {
                                        if (ld_vers_base(ofl) ==
                                            (Ver_desc *)S_ERROR)
                                                return (S_ERROR);
                                }
                                ofl->ofl_flags |= FLG_OF_VERDEF;
                                if ((ovdp = ld_vers_find(name, hash,
                                    ofl->ofl_verdesc)) == NULL) {
                                        if ((ovdp = ld_vers_desc(name, hash,
                                            &ofl->ofl_verdesc)) ==
                                            (Ver_desc *)S_ERROR)
                                                return (S_ERROR);

                                        /* LINTED */
                                        ovdp->vd_ndx = (Half)++ofl->ofl_vercnt;
                                        ovdp->vd_file = ifl;
                                        ovdp->vd_flags = vdf->vd_flags;
                                }
                        }

                        /*
                         * Maintain the association between the input version
                         * descriptor and the output version descriptor so that
                         * an associated symbols will be assigned to the
                         * correct version.
                         */
                        ivdp->vd_ref = ovdp;
                }

                /*
                 * Process any dependencies this version may have.
                 */
                vdap = (Verdaux *)((uintptr_t)vdap + vdap->vda_next);
                for (cnt--; cnt; cnt--,
                    vdap = (Verdaux *)((uintptr_t)vdap + vdap->vda_next)) {
                        Ver_desc        *_ivdp;

                        name = (char *)(str + vdap->vda_name);
                        /* LINTED */
                        hash = (Word)elf_hash(name);

                        if (((_ivdp = ld_vers_find(name, hash,
                            ifl->ifl_verdesc)) == NULL) &&
                            ((_ivdp = ld_vers_desc(name, hash,
                            &ifl->ifl_verdesc)) == (Ver_desc *)S_ERROR))
                                return (S_ERROR);

                        if (aplist_append(&ivdp->vd_deps, _ivdp,
                            AL_CNT_VERDESCS) == NULL)
                                return (S_ERROR);
                }
                DBG_CALL(Dbg_ver_desc_entry(ofl->ofl_lml, ivdp));
        }

        /*
         * Now that we know the total number of version definitions for this
         * file, build an index array for fast access when processing symbols.
         */
        if ((ifl->ifl_verndx =
            vers_index(ofl, ifl, relobj)) == (Ver_index *)S_ERROR)
                return (S_ERROR);

        if (relobj)
                return (1);

        /*
         * If this object has version control definitions against it then these
         * must be processed so as to select those version definitions to which
         * symbol bindings can occur.  Otherwise simply mark all versions as
         * available.
         */
        DBG_CALL(Dbg_ver_avail_title(ofl->ofl_lml, file));

        if (sdf && (sdf->sdf_flags & FLG_SDF_SELECT)) {
                Aliste  idx1;

                for (ALIST_TRAVERSE(sdf->sdf_vers, idx1, sdv)) {
                        Aliste          idx2;
                        Ver_desc        *vdp;
                        int             found = 0;

                        for (APLIST_TRAVERSE(ifl->ifl_verdesc, idx2, vdp)) {
                                if (strcmp(sdv->sdv_name, vdp->vd_name) == 0) {
                                        found++;
                                        break;
                                }
                        }
                        if (found)
                                vers_select(ofl, ifl, vdp, sdv->sdv_ref);
                        else
                                ld_eprintf(ofl, ERR_FATAL,
                                    MSG_INTL(MSG_VER_NOEXIST), ifl->ifl_name,
                                    sdv->sdv_name, sdv->sdv_ref);
                }
        } else {
                Ver_index       *vip;
                int             cnt;

                for (cnt = VER_NDX_GLOBAL; cnt <= ifl->ifl_vercnt; cnt++) {
                        vip = &ifl->ifl_verndx[cnt];
                        vip->vi_flags |= FLG_VER_AVAIL;
                        DBG_CALL(Dbg_ver_avail_entry(ofl->ofl_lml, vip, 0));
                }
        }

        /*
         * If this is an explict dependency indicate that this file is a
         * candidate for requiring version needed information to be recorded in
         * the image we're creating.
         */
        if (ifl->ifl_flags & FLG_IF_NEEDED)
                ofl->ofl_flags |= FLG_OF_VERNEED;

        return (1);
}

/*
 * Process a version needed section.
 */
uintptr_t
ld_vers_need_process(Is_desc *isp, Ifl_desc *ifl, Ofl_desc *ofl)
{
        const char      *str, *file = ifl->ifl_name;
        Word            num, _num;
        Verneed         *vnd;

        vnd = (Verneed *)isp->is_indata->d_buf;

        /*
         * Verify the version revision.  We only check the first version
         * structure as it is assumed all other version structures in this
         * data section will be of the same revision.
         */
        if (vnd->vn_version > VER_DEF_CURRENT) {
                ld_eprintf(ofl, ERR_WARNING, MSG_INTL(MSG_VER_HIGHER),
                    ifl->ifl_name, vnd->vn_version, VER_DEF_CURRENT);
        }

        num = isp->is_shdr->sh_info;
        str = (char *)ifl->ifl_isdesc[isp->is_shdr->sh_link]->is_indata->d_buf;

        DBG_CALL(Dbg_ver_need_title(ofl->ofl_lml, file));

        /*
         * Loop through the version information setting up a version descriptor
         * for each version definition.
         */
        for (_num = 1; _num <= num; _num++,
            vnd = (Verneed *)((uintptr_t)vnd + vnd->vn_next)) {
                Sdf_desc        *sdf;
                const char      *name;
                Half            cnt = vnd->vn_cnt;
                Vernaux         *vnap = (Vernaux *)((uintptr_t)vnd +
                    vnd->vn_aux);
                Half            _cnt;

                name = (char *)(str + vnd->vn_file);

                /*
                 * Set up a shared object descriptor and add to it the necessary
                 * needed versions.  This information may also have been added
                 * by a mapfile (see map_dash()).
                 */
                if ((sdf = sdf_find(name, ofl->ofl_soneed)) == NULL) {
                        if ((sdf = sdf_add(name, &ofl->ofl_soneed)) ==
                            (Sdf_desc *)S_ERROR)
                                return (S_ERROR);
                        sdf->sdf_rfile = file;
                        sdf->sdf_flags |= FLG_SDF_VERIFY;
                }

                for (_cnt = 0; cnt; _cnt++, cnt--,
                    vnap = (Vernaux *)((uintptr_t)vnap + vnap->vna_next)) {
                        Sdv_desc        sdv;

                        sdv.sdv_name = str + vnap->vna_name;
                        sdv.sdv_ref = file;
                        sdv.sdv_flags = 0;

                        if (alist_append(&sdf->sdf_vers, &sdv,
                            sizeof (Sdv_desc), AL_CNT_SDF_VERSIONS) == NULL)
                                return (S_ERROR);

                        DBG_CALL(Dbg_ver_need_entry(ofl->ofl_lml, _cnt, name,
                            sdv.sdv_name));
                }
        }
        return (1);
}

/*
 * If a symbol is obtained from a versioned relocatable object then the symbols
 * version association must be promoted to the version definition as it will be
 * represented in the output file.
 */
void
ld_vers_promote(Sym_desc *sdp, Word ndx, Ifl_desc *ifl, Ofl_desc *ofl)
{
        Half    vndx;

        /*
         * A version symbol index of 0 implies the symbol is local.  A value of
         * VER_NDX_GLOBAL implies the symbol is global but has not been
         * assigned to a specfic version definition.
         */
        vndx = ifl->ifl_versym[ndx];
        if (vndx == 0) {
                sdp->sd_flags |= (FLG_SY_REDUCED | FLG_SY_HIDDEN);
                return;
        }

        if (vndx == VER_NDX_ELIMINATE) {
                sdp->sd_flags |= (FLG_SY_REDUCED | FLG_SY_HIDDEN | FLG_SY_ELIM);
                return;
        }

        if (vndx == VER_NDX_GLOBAL) {
                if (!SYM_IS_HIDDEN(sdp))
                        sdp->sd_flags |= (FLG_SY_DEFAULT | FLG_SY_EXPDEF);
                if (sdp->sd_aux->sa_overndx <= VER_NDX_GLOBAL)
                        sdp->sd_aux->sa_overndx = VER_NDX_GLOBAL;
                return;
        }

        /*
         * Any other version index requires association to the appropriate
         * version definition.
         */
        if ((ifl->ifl_verndx == 0) || (vndx > ifl->ifl_vercnt)) {
                ld_eprintf(ofl, ERR_FATAL, MSG_INTL(MSG_VER_INVALNDX),
                    sdp->sd_name, ifl->ifl_name, vndx);
                return;
        }

        if (!SYM_IS_HIDDEN(sdp))
                sdp->sd_flags |= (FLG_SY_DEFAULT | FLG_SY_EXPDEF);

        /*
         * Promote the symbols version index to the appropriate output version
         * definition.
         */
        if (!(sdp->sd_flags & FLG_SY_VERSPROM)) {
                Ver_index       *vip;

                vip = &ifl->ifl_verndx[vndx];
                sdp->sd_aux->sa_overndx = vip->vi_desc->vd_ref->vd_ndx;
                sdp->sd_flags |= FLG_SY_VERSPROM;
        }
}

/*
 * If any versioning is called for make sure an initial version descriptor is
 * assigned to represent the file itself.  Known as the base version.
 */
Ver_desc *
ld_vers_base(Ofl_desc *ofl)
{
        Ver_desc        *vdp;
        const char      *name;

        /*
         * Determine the filename to associate to the version descriptor.  This
         * is either the SONAME (if one has been supplied) or the basename of
         * the output file.
         */
        if ((name = ofl->ofl_soname) == NULL) {
                const char      *str = ofl->ofl_name;

                while (*str != '\0') {
                        if (*str++ == '/')
                                name = str;
                }
                if (name == NULL)
                        name = ofl->ofl_name;
        }

        /*
         * Generate the version descriptor.
         */
        /* LINTED */
        if ((vdp = ld_vers_desc(name, (Word)elf_hash(name),
            &ofl->ofl_verdesc)) == (Ver_desc *)S_ERROR)
                return ((Ver_desc *)S_ERROR);

        /*
         * Assign the base index to this version and initialize the output file
         * descriptor with the number of version descriptors presently in use.
         */
        vdp->vd_ndx = ofl->ofl_vercnt = VER_NDX_GLOBAL;
        vdp->vd_flags |= VER_FLG_BASE;

        return (vdp);
}

/*
 * Now that all input shared objects have been processed, verify that all
 * version requirements have been met.  Any version control requirements will
 * have been specified by the user (and placed on the ofl_oscntl list) and are
 * verified at the time the object was processed (see ver_def_process()).
 * Here we process all version requirements established from shared objects
 * themselves (ie,. NEEDED dependencies).
 */
int
ld_vers_verify(Ofl_desc *ofl)
{
        Aliste          idx1;
        Sdf_desc        *sdf;
        char            *nv;

        /*
         * As with the runtime environment, disable all version verification if
         * requested.
         */
#if     defined(_ELF64)
        if ((nv = getenv(MSG_ORIG(MSG_LD_NOVERSION_64))) == NULL)
#else
        if ((nv = getenv(MSG_ORIG(MSG_LD_NOVERSION_32))) == NULL)
#endif
                nv = getenv(MSG_ORIG(MSG_LD_NOVERSION));

        if (nv && nv[0])
                return (1);

        for (APLIST_TRAVERSE(ofl->ofl_soneed, idx1, sdf)) {
                Aliste          idx2;
                Sdv_desc        *sdv;
                Ifl_desc        *ifl = sdf->sdf_file;

                if (!(sdf->sdf_flags & FLG_SDF_VERIFY))
                        continue;

                /*
                 * If this file contains no version definitions then ignore
                 * any versioning verification.  This is the same model as
                 * carried out by ld.so.1 and is intended to allow backward
                 * compatibility should a shared object with a version
                 * requirement be returned to an older system on which a
                 * non-versioned shared object exists.
                 */
                if ((ifl == NULL) || (ifl->ifl_verdesc == NULL))
                        continue;

                /*
                 * If individual versions were specified for this file make
                 * sure that they actually exist in the appropriate file, and
                 * that they are available for binding.
                 */
                for (ALIST_TRAVERSE(sdf->sdf_vers, idx2, sdv)) {
                        Aliste          idx3;
                        Ver_desc        *vdp;
                        int             found = 0;

                        for (APLIST_TRAVERSE(ifl->ifl_verdesc, idx3, vdp)) {
                                if (strcmp(sdv->sdv_name, vdp->vd_name) == 0) {
                                        found++;
                                        break;
                                }
                        }
                        if (found) {
                                Ver_index       *vip;

                                vip = &ifl->ifl_verndx[vdp->vd_ndx];
                                if (!(vip->vi_flags & FLG_VER_AVAIL)) {
                                        ld_eprintf(ofl, ERR_FATAL,
                                            MSG_INTL(MSG_VER_UNAVAIL),
                                            ifl->ifl_name, sdv->sdv_name,
                                            sdv->sdv_ref);
                                }
                        } else {
                                ld_eprintf(ofl, ERR_FATAL,
                                    MSG_INTL(MSG_VER_NOEXIST), ifl->ifl_name,
                                    sdv->sdv_name, sdv->sdv_ref);
                        }
                }
        }
        return (1);
}