libelf/common/newphdr.c

	newphdr.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_newphdr = _elf32_newphdr
#endif

#include "syn.h"
#include <stdlib.h>
#include <memory.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_newphdr elf64_newphdr
#define elf_getehdr elf64_getehdr
#define _elf_msize  _elf64_msize
#define elf_fsize   elf64_fsize

#else   /* else ELF32 */

#define ELFCLASS    ELFCLASS32
#define elf_newphdr elf32_newphdr
#define elf_getehdr elf32_getehdr
#define _elf_msize  _elf32_msize
#define elf_fsize   elf32_fsize

#endif /* ELF64 */


Phdr *
elf_newphdr(Elf * elf, size_t count)
{
    Elf_Void *  ph;
    size_t      sz;
    Phdr *      rc;
    unsigned    work;

    if (elf == 0)
        return (0);
    ELFRLOCK(elf)
    if (elf->ed_class != ELFCLASS) {
        _elf_seterr(EREQ_CLASS, 0);
        ELFUNLOCK(elf)
        return (0);
    }
    ELFUNLOCK(elf)
    if (elf_getehdr(elf) == 0) {        /* this cooks if necessary */
        _elf_seterr(ESEQ_EHDR, 0);
        return (0);
    }

    /*
     * Free the existing header if appropriate.  This could reuse
     * existing space if big enough, but that's unlikely, benefit
     * would be negligible, and code would be more complicated.
     */

    ELFWLOCK(elf)
    if (elf->ed_myflags & EDF_PHALLOC) {
        elf->ed_myflags &= ~EDF_PHALLOC;
        rc = elf->ed_phdr;
        free(rc);
    }

    /*
     * Delete the header if count is zero.
     */

    ELFACCESSDATA(work, _elf_work)
    if ((sz = count * _elf_msize(ELF_T_PHDR, work)) == 0) {
        elf->ed_phflags &= ~ELF_F_DIRTY;
        elf->ed_phdr = 0;
        ((Ehdr*)elf->ed_ehdr)->e_phnum = 0;
        ((Ehdr*)elf->ed_ehdr)->e_phentsize = 0;
        elf->ed_phdrsz = 0;
        ELFUNLOCK(elf)
        return (0);
    }

    if ((ph = malloc(sz)) == 0) {
        _elf_seterr(EMEM_PHDR, errno);
        elf->ed_phflags &= ~ELF_F_DIRTY;
        elf->ed_phdr = 0;
        ((Ehdr*)elf->ed_ehdr)->e_phnum = 0;
        ((Ehdr*)elf->ed_ehdr)->e_phentsize = 0;
        elf->ed_phdrsz = 0;
        ELFUNLOCK(elf)
        return (0);
    }

    elf->ed_myflags |= EDF_PHALLOC;
    (void) memset(ph, 0, sz);
    elf->ed_phflags |= ELF_F_DIRTY;
    /* LINTED */
    ((Ehdr*)elf->ed_ehdr)->e_phnum = (Half)count;
    ((Ehdr*)elf->ed_ehdr)->e_phentsize
        /* LINTED */
        = (Half)elf_fsize(ELF_T_PHDR, 1, work);
    elf->ed_phdrsz = sz;
    elf->ed_phdr = rc = ph;

    ELFUNLOCK(elf)
    return (rc);
}