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1 /* |
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2 * newscn.c - implementation of the elf_newscn(3) function. |
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3 * Copyright (C) 1995 - 2006 Michael Riepe |
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4 * |
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5 * This library is free software; you can redistribute it and/or |
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6 * modify it under the terms of the GNU Library General Public |
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7 * License as published by the Free Software Foundation; either |
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8 * version 2 of the License, or (at your option) any later version. |
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9 * |
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10 * This library is distributed in the hope that it will be useful, |
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11 * but WITHOUT ANY WARRANTY; without even the implied warranty of |
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12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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13 * Library General Public License for more details. |
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14 * |
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15 * You should have received a copy of the GNU Library General Public |
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16 * License along with this library; if not, write to the Free Software |
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17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
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18 */ |
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19 |
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20 #include <private.h> |
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21 |
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22 #ifndef lint |
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23 static const char rcsid[] = "@(#) $Id: newscn.c,v 1.12 2006/07/07 22:17:01 michael Exp $"; |
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24 #endif /* lint */ |
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25 |
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26 int |
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27 _elf_update_shnum(Elf *elf, size_t shnum) { |
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28 size_t extshnum = 0; |
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29 Elf_Scn *scn; |
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30 |
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31 elf_assert(elf); |
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32 elf_assert(elf->e_ehdr); |
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33 scn = elf->e_scn_1; |
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34 elf_assert(scn); |
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35 elf_assert(scn->s_index == 0); |
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36 if (shnum >= SHN_LORESERVE) { |
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37 extshnum = shnum; |
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38 shnum = 0; |
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39 } |
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40 if (elf->e_class == ELFCLASS32) { |
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41 ((Elf32_Ehdr*)elf->e_ehdr)->e_shnum = shnum; |
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42 scn->s_shdr32.sh_size = extshnum; |
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43 } |
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44 #if __LIBELF64 |
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45 else if (elf->e_class == ELFCLASS64) { |
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46 ((Elf64_Ehdr*)elf->e_ehdr)->e_shnum = shnum; |
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47 scn->s_shdr64.sh_size = extshnum; |
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48 } |
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49 #endif /* __LIBELF64 */ |
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50 else { |
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51 if (valid_class(elf->e_class)) { |
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52 seterr(ERROR_UNIMPLEMENTED); |
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53 } |
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54 else { |
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55 seterr(ERROR_UNKNOWN_CLASS); |
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56 } |
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57 return -1; |
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58 } |
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59 elf->e_ehdr_flags |= ELF_F_DIRTY; |
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60 scn->s_shdr_flags |= ELF_F_DIRTY; |
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61 return 0; |
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62 } |
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63 |
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64 static Elf_Scn* |
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65 _makescn(Elf *elf, size_t index) { |
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66 Elf_Scn *scn; |
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67 |
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68 elf_assert(elf); |
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69 elf_assert(elf->e_magic == ELF_MAGIC); |
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70 elf_assert(elf->e_ehdr); |
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71 elf_assert(_elf_scn_init.s_magic == SCN_MAGIC); |
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72 if (!(scn = (Elf_Scn*)malloc(sizeof(*scn)))) { |
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73 seterr(ERROR_MEM_SCN); |
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74 return NULL; |
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75 } |
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76 *scn = _elf_scn_init; |
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77 scn->s_elf = elf; |
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78 scn->s_scn_flags = ELF_F_DIRTY; |
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79 scn->s_shdr_flags = ELF_F_DIRTY; |
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80 scn->s_freeme = 1; |
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81 scn->s_index = index; |
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82 return scn; |
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83 } |
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84 |
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85 Elf_Scn* |
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86 _elf_first_scn(Elf *elf) { |
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87 Elf_Scn *scn; |
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88 |
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89 elf_assert(elf); |
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90 elf_assert(elf->e_magic == ELF_MAGIC); |
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91 if ((scn = elf->e_scn_1)) { |
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92 return scn; |
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93 } |
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94 if ((scn = _makescn(elf, 0))) { |
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95 elf->e_scn_1 = elf->e_scn_n = scn; |
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96 if (_elf_update_shnum(elf, 1)) { |
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97 free(scn); |
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98 elf->e_scn_1 = elf->e_scn_n = scn = NULL; |
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99 } |
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100 } |
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101 return scn; |
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102 } |
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103 |
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104 static Elf_Scn* |
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105 _buildscn(Elf *elf) { |
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106 Elf_Scn *scn; |
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107 |
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108 if (!_elf_first_scn(elf)) { |
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109 return NULL; |
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110 } |
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111 scn = elf->e_scn_n; |
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112 elf_assert(scn); |
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113 if (!(scn = _makescn(elf, scn->s_index + 1))) { |
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114 return NULL; |
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115 } |
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116 if (_elf_update_shnum(elf, scn->s_index + 1)) { |
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117 free(scn); |
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118 return NULL; |
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119 } |
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120 elf->e_scn_n = elf->e_scn_n->s_link = scn; |
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121 return scn; |
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122 } |
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123 |
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124 Elf_Scn* |
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125 elf_newscn(Elf *elf) { |
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126 Elf_Scn *scn; |
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127 |
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128 if (!elf) { |
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129 return NULL; |
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130 } |
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131 elf_assert(elf->e_magic == ELF_MAGIC); |
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132 if (!elf->e_readable && !elf->e_ehdr) { |
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133 seterr(ERROR_NOEHDR); |
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134 } |
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135 else if (elf->e_kind != ELF_K_ELF) { |
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136 seterr(ERROR_NOTELF); |
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137 } |
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138 else if (!elf->e_ehdr && !_elf_cook(elf)) { |
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139 return NULL; |
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140 } |
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141 else if ((scn = _buildscn(elf))) { |
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142 return scn; |
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143 } |
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144 return NULL; |
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145 } |