usr/src/cmd/sgs/libelf/common/newehdr.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21
  22 /*
  23  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26
  27 /*      Copyright (c) 1988 AT&T */
  28 /*        All Rights Reserved   */
  29
  30 #pragma ident   "%Z%%M% %I%     %E% SMI"
  31
  32 #include <stdlib.h>
  33 #include <errno.h>
  34 #include "decl.h"
  35 #include "msg.h"
  36
  37 /*
  38  * This module is compiled twice, the second time having
  39  * -D_ELF64 defined.  The following set of macros, along
  40  * with machelf.h, represent the differences between the
  41  * two compilations.  Be careful *not* to add any class-
  42  * dependent code (anything that has elf32 or elf64 in the
  43  * name) to this code without hiding it behind a switch-
  44  * able macro like these.
  45  */
  46 #if     defined(_ELF64)
  47
  48 #define ELFCLASS                ELFCLASS64
  49 #define _elf_ehdr_init          _elf64_ehdr_init
  50 #define elf_newehdr             elf64_newehdr
  51 #define getehdr                 elf64_getehdr
  52
  53 #else   /* else ELF32 */
  54
  55 #define ELFCLASS                ELFCLASS32
  56 #define _elf_ehdr_init          _elf32_ehdr_init
  57 #define elf_newehdr             elf32_newehdr
  58 #define getehdr                 elf32_getehdr
  59
  60 #endif  /* ELF64 */
  61
  62
  63 Ehdr *
  64 elf_newehdr(Elf * elf)
  65 {
  66         Ehdr    *eh;
  67
  68         if (elf == 0)
  69                 return (0);
  70
  71         /*
  72          * If reading file, return its hdr
  73          */
  74
  75         ELFWLOCK(elf)
  76         if (elf->ed_myflags & EDF_READ) {
  77                 ELFUNLOCK(elf)
  78                 if ((eh = (Ehdr *)getehdr(elf)) != 0) {
  79                         ELFWLOCK(elf)
  80                         elf->ed_ehflags |= ELF_F_DIRTY;
  81                         ELFUNLOCK(elf)
  82                 }
  83                 return (eh);
  84         }
  85
  86         /*
  87          * Writing file
  88          */
  89
  90         if (elf->ed_class == ELFCLASSNONE)
  91                 elf->ed_class = ELFCLASS;
  92         else if (elf->ed_class != ELFCLASS) {
  93                 _elf_seterr(EREQ_CLASS, 0);
  94                 ELFUNLOCK(elf)
  95                 return (0);
  96         }
  97         ELFUNLOCK(elf);
  98         if ((eh = (Ehdr *)getehdr(elf)) != 0) { /* this cooks if necessary */
  99                 ELFWLOCK(elf)
 100                 elf->ed_ehflags |= ELF_F_DIRTY;
 101                 ELFUNLOCK(elf)
 102                 return (eh);
 103         }
 104         ELFWLOCK(elf)
 105
 106         if ((eh = (Ehdr *)malloc(sizeof (Ehdr))) == 0) {
 107                 _elf_seterr(EMEM_EHDR, errno);
 108                 ELFUNLOCK(elf)
 109                 return (0);
 110         }
 111         *eh = _elf_ehdr_init;
 112         elf->ed_myflags |= EDF_EHALLOC;
 113         elf->ed_ehflags |= ELF_F_DIRTY;
 114         elf->ed_ehdr = eh;
 115         ELFUNLOCK(elf)
 116         return (eh);
 117 }