libelf/common/newehdr.c

	newehdr.c revision 7c478bd95313f5f23a4c958a745db2134aa03244
/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (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) 1988 AT&T */
/*    All Rights Reserved   */


/*
 * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#pragma ident   "%Z%%M% %I% %E% SMI"

#if !defined(_ELF64)
#pragma weak elf32_newehdr = _elf32_newehdr
#endif

#include "syn.h"
#include <stdlib.h>
#include <errno.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 ELFCLASS        ELFCLASS64
#define _elf_ehdr_init      _elf64_ehdr_init
#define elf_newehdr     elf64_newehdr
#define getehdr         elf64_getehdr

#else   /* else ELF32 */

#define ELFCLASS        ELFCLASS32
#define _elf_ehdr_init      _elf32_ehdr_init
#define elf_newehdr     _elf32_newehdr
#define getehdr         elf32_getehdr

#endif  /* ELF64 */


Ehdr *
elf_newehdr(Elf * elf)
{
    register
    Ehdr    *eh;

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

    /*
     * If reading file, return its hdr
     */

    ELFWLOCK(elf)
    if (elf->ed_myflags & EDF_READ) {
        ELFUNLOCK(elf)
        if ((eh = (Ehdr *)getehdr(elf)) != 0) {
            ELFWLOCK(elf)
            elf->ed_ehflags |= ELF_F_DIRTY;
            ELFUNLOCK(elf)
        }
        return (eh);
    }

    /*
     * Writing file
     */

    if (elf->ed_class == ELFCLASSNONE)
        elf->ed_class = ELFCLASS;
    else if (elf->ed_class != ELFCLASS) {
        _elf_seterr(EREQ_CLASS, 0);
        ELFUNLOCK(elf)
        return (0);
    }
    ELFUNLOCK(elf);
    if ((eh = (Ehdr *)getehdr(elf)) != 0) { /* this cooks if necessary */
        ELFWLOCK(elf)
        elf->ed_ehflags |= ELF_F_DIRTY;
        ELFUNLOCK(elf)
        return (eh);
    }
    ELFWLOCK(elf)

    if ((eh = (Ehdr *)malloc(sizeof (Ehdr))) == 0) {
        _elf_seterr(EMEM_EHDR, errno);
        ELFUNLOCK(elf)
        return (0);
    }
    *eh = _elf_ehdr_init;
    elf->ed_myflags |= EDF_EHALLOC;
    elf->ed_ehflags |= ELF_F_DIRTY;
    elf->ed_ehdr = eh;
    ELFUNLOCK(elf)
    return (eh);
}