/*
 * 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 <sys/mman.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <libelf.h>
#include <errno.h>
#include "decl.h"
#include "msg.h"

/*
 * File output
 *      These functions write output files.
 *      On SVR4 and newer systems use mmap(2).  On older systems (or on
 *      file systems that don't support mmap), use write(2).
 */


char *
_elf_outmap(int fd, size_t sz, unsigned int *pflag)
{
        char    *p;

        /*
         * Note: Some NFS implementations do not provide from enlarging a file
         * via ftruncate(), thus this may fail with ENOSUP.  In this case the
         * fall through to the calloc() mechanism will occur.
         */
        if ((!*pflag) && (ftruncate(fd, (off_t)sz) == 0) &&
            (p = mmap((char *)0, sz, PROT_READ+PROT_WRITE,
            MAP_SHARED, fd, (off_t)0)) != (char *)-1) {
                *pflag = 1;
                return (p);
        }

        *pflag = 0;

        /*
         * If mmap fails, try calloc.  Some file systems don't mmap.  Note, we
         * use calloc rather than malloc, as ld(1) assumes that the backing
         * storage it is working with is zero filled.
         */
        if ((p = (char *)calloc(1, sz)) == 0)
                _elf_seterr(EMEM_OUT, errno);
        return (p);
}


size_t
_elf_outsync(int fd, char *p, size_t sz, unsigned int flag)
{
        if (flag != 0) {
                int     rv, err;

                err = ENOTSUP; /* msync should only return 0 or -1 */
                rv = msync(p, sz, MS_ASYNC);
                if (rv == -1)
                        err = errno;
                (void) munmap(p, sz);
                if (rv == 0)
                        return (sz);
                _elf_seterr(EIO_SYNC, err);
                return (0);
        }
        if ((lseek(fd, 0L, SEEK_SET) == 0) &&
            (write(fd, p, sz) == sz)) {
                (void) free(p);
                return (sz);
        }
        _elf_seterr(EIO_WRITE, errno);
        return (0);
}