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1 /* |
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2 * x.elfext.c -- handle ELF format extensions |
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3 * Copyright (C) 2002 - 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: x.elfext.c,v 1.3 2006/07/07 22:17:50 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_getphnum(Elf *elf, size_t *resultp) { |
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28 if (!elf) { |
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29 return LIBELF_FAILURE; |
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30 } |
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31 elf_assert(elf->e_magic == ELF_MAGIC); |
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32 if (elf->e_kind != ELF_K_ELF) { |
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33 seterr(ERROR_NOTELF); |
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34 return LIBELF_FAILURE; |
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35 } |
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36 if (!elf->e_ehdr && !_elf_cook(elf)) { |
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37 return LIBELF_FAILURE; |
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38 } |
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39 if (resultp) { |
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40 *resultp = elf->e_phnum; |
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41 } |
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42 return LIBELF_SUCCESS; |
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43 } |
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44 |
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45 int |
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46 elf_getshnum(Elf *elf, size_t *resultp) { |
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47 size_t num = 0; |
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48 Elf_Scn *scn; |
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49 |
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50 if (!elf) { |
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51 return LIBELF_FAILURE; |
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52 } |
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53 elf_assert(elf->e_magic == ELF_MAGIC); |
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54 if (elf->e_kind != ELF_K_ELF) { |
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55 seterr(ERROR_NOTELF); |
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56 return LIBELF_FAILURE; |
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57 } |
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58 if (!elf->e_ehdr && !_elf_cook(elf)) { |
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59 return LIBELF_FAILURE; |
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60 } |
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61 if ((scn = elf->e_scn_n)) { |
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62 num = scn->s_index + 1; |
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63 } |
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64 if (resultp) { |
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65 *resultp = num; |
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66 } |
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67 return LIBELF_SUCCESS; |
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68 } |
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69 |
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70 int |
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71 elf_getshstrndx(Elf *elf, size_t *resultp) { |
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72 size_t num = 0; |
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73 size_t dummy; |
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74 Elf_Scn *scn; |
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75 |
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76 if (!elf) { |
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77 return LIBELF_FAILURE; |
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78 } |
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79 elf_assert(elf->e_magic == ELF_MAGIC); |
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80 if (resultp == NULL) { |
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81 resultp = &dummy; /* handle NULL pointer gracefully */ |
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82 } |
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83 if (elf->e_kind != ELF_K_ELF) { |
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84 seterr(ERROR_NOTELF); |
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85 return LIBELF_FAILURE; |
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86 } |
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87 if (!elf->e_ehdr && !_elf_cook(elf)) { |
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88 return LIBELF_FAILURE; |
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89 } |
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90 if (elf->e_class == ELFCLASS32) { |
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91 num = ((Elf32_Ehdr*)elf->e_ehdr)->e_shstrndx; |
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92 } |
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93 #if __LIBELF64 |
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94 else if (elf->e_class == ELFCLASS64) { |
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95 num = ((Elf64_Ehdr*)elf->e_ehdr)->e_shstrndx; |
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96 } |
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97 #endif /* __LIBELF64 */ |
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98 else { |
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99 if (valid_class(elf->e_class)) { |
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100 seterr(ERROR_UNIMPLEMENTED); |
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101 } |
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102 else { |
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103 seterr(ERROR_UNKNOWN_CLASS); |
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104 } |
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105 return LIBELF_FAILURE; |
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106 } |
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107 if (num != SHN_XINDEX) { |
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108 *resultp = num; |
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109 return LIBELF_SUCCESS; |
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110 } |
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111 /* |
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112 * look at first section header |
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113 */ |
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114 if (!(scn = elf->e_scn_1)) { |
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115 seterr(ERROR_NOSUCHSCN); |
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116 return LIBELF_FAILURE; |
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117 } |
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118 elf_assert(scn->s_magic == SCN_MAGIC); |
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119 #if __LIBELF64 |
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120 if (elf->e_class == ELFCLASS64) { |
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121 *resultp = scn->s_shdr64.sh_link; |
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122 return LIBELF_SUCCESS; |
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123 } |
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124 #endif /* __LIBELF64 */ |
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125 *resultp = scn->s_shdr32.sh_link; |
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126 return LIBELF_SUCCESS; |
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127 } |
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128 |
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129 int |
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130 elfx_update_shstrndx(Elf *elf, size_t value) { |
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131 size_t extvalue = 0; |
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132 Elf_Scn *scn; |
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133 |
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134 if (!elf) { |
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135 return LIBELF_FAILURE; |
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136 } |
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137 elf_assert(elf->e_magic == ELF_MAGIC); |
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138 if (value >= SHN_LORESERVE) { |
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139 extvalue = value; |
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140 value = SHN_XINDEX; |
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141 } |
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142 if (elf->e_kind != ELF_K_ELF) { |
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143 seterr(ERROR_NOTELF); |
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144 return LIBELF_FAILURE; |
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145 } |
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146 if (!elf->e_ehdr && !_elf_cook(elf)) { |
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147 return LIBELF_FAILURE; |
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148 } |
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149 if (!(scn = _elf_first_scn(elf))) { |
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150 return LIBELF_FAILURE; |
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151 } |
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152 elf_assert(scn->s_magic == SCN_MAGIC); |
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153 if (elf->e_class == ELFCLASS32) { |
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154 ((Elf32_Ehdr*)elf->e_ehdr)->e_shstrndx = value; |
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155 scn->s_shdr32.sh_link = extvalue; |
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156 } |
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157 #if __LIBELF64 |
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158 else if (elf->e_class == ELFCLASS64) { |
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159 ((Elf64_Ehdr*)elf->e_ehdr)->e_shstrndx = value; |
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160 scn->s_shdr64.sh_link = extvalue; |
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161 } |
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162 #endif /* __LIBELF64 */ |
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163 else { |
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164 if (valid_class(elf->e_class)) { |
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165 seterr(ERROR_UNIMPLEMENTED); |
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166 } |
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167 else { |
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168 seterr(ERROR_UNKNOWN_CLASS); |
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169 } |
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170 return LIBELF_FAILURE; |
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171 } |
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172 elf->e_ehdr_flags |= ELF_F_DIRTY; |
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173 scn->s_shdr_flags |= ELF_F_DIRTY; |
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174 return LIBELF_SUCCESS; |
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175 } |