/*
 * 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 2008 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

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

#include "libelf.h"
#include "decl.h"
#include "msg.h"


Elf_Data *
elf_newdata(Elf_Scn * s)
{
        Dnode *         d;
        Elf_Data *      rc;
        Elf *           elf;
        unsigned        work;

        if (s == 0)
                return (0);
        elf = s->s_elf;
        READLOCKS(elf, s)
        if (s->s_index == SHN_UNDEF) {
                _elf_seterr(EREQ_SCNNULL, 0);
                READUNLOCKS(elf, s)
                return (0);
        }

        if ((s->s_myflags & SF_READY) == 0) {
                UPGRADELOCKS(elf, s)
                /*
                 * re-confirm that another 'thread' hasn't come along
                 * and cooked this section while the locks were
                 * obtained.
                 */
                if ((s->s_myflags & SF_READY) == 0)
                        (void) _elf_cookscn(s);
                DOWNGRADELOCKS(elf, s)
        }

        /*
         * If this is the first new node, use the one allocated
         * in the scn itself.  Update data buffer in both cases.
         */
        ELFACCESSDATA(work, _elf_work)
        if (s->s_hdnode == 0) {
                s->s_dnode.db_uflags |= ELF_F_DIRTY;
                s->s_dnode.db_myflags |= DBF_READY;
                s->s_hdnode = &s->s_dnode;
                s->s_tlnode = &s->s_dnode;
                s->s_dnode.db_scn = s;
                s->s_dnode.db_data.d_version = work;
                rc = &s->s_dnode.db_data;
                READUNLOCKS(elf, s)
                return (rc);
        }
        if ((d = _elf_dnode()) == 0) {
                READUNLOCKS(elf, s)
                return (0);
        }
        d->db_data.d_version = work;
        d->db_scn = s;
        d->db_uflags |= ELF_F_DIRTY;
        d->db_myflags |= DBF_READY;
        s->s_tlnode->db_next = d;
        s->s_tlnode = d;
        rc = &d->db_data;
        READUNLOCKS(elf, s)
        return (rc);
}