1 | /* |
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2 | * Copyright (c) 2011-2012, Chris Johns <chrisj@rtems.org> |
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3 | * |
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4 | * Permission to use, copy, modify, and/or distribute this software for any |
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5 | * purpose with or without fee is hereby granted, provided that the above |
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6 | * copyright notice and this permission notice appear in all copies. |
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7 | * |
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8 | * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES |
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9 | * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF |
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10 | * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR |
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11 | * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES |
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12 | * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN |
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13 | * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF |
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14 | * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. |
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15 | */ |
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16 | /** |
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17 | * @file |
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18 | * |
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19 | * @ingroup rtems-ld |
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20 | * |
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21 | * @brief RTEMS Linker ELF module manages the ELF format images. |
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22 | * |
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23 | */ |
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24 | |
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25 | #include <string.h> |
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26 | |
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27 | #include <rld.h> |
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28 | |
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29 | namespace rld |
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30 | { |
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31 | namespace elf |
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32 | { |
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33 | /** |
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34 | * Throw an ELF error. |
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35 | * |
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36 | * @param where Where the error is raised. |
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37 | */ |
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38 | void libelf_error (const std::string& where) |
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39 | { |
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40 | throw rld::error (::elf_errmsg (-1), "libelf:" + where); |
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41 | } |
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42 | |
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43 | /** |
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44 | * We record the first class, machine and .. type of object file we get the |
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45 | * header of and all header must match. We cannot mix object module types. |
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46 | */ |
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47 | static unsigned int elf_object_class = ELFCLASSNONE; |
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48 | static unsigned int elf_object_machinetype = EM_NONE; |
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49 | static unsigned int elf_object_datatype = ELFDATANONE; |
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50 | |
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51 | /** |
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52 | * A single place to initialise the libelf library. This must be called |
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53 | * before any libelf API calls are made. |
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54 | */ |
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55 | static void |
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56 | libelf_initialise () |
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57 | { |
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58 | static bool libelf_initialised = false; |
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59 | if (!libelf_initialised) |
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60 | { |
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61 | if (::elf_version (EV_CURRENT) == EV_NONE) |
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62 | libelf_error ("initialisation"); |
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63 | libelf_initialised = true; |
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64 | } |
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65 | } |
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66 | |
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67 | relocation::relocation (const symbols::symbol& sym, |
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68 | elf_addr offset, |
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69 | elf_xword info, |
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70 | elf_sxword addend) |
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71 | : sym (&sym), |
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72 | offset_ (offset), |
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73 | info_ (info), |
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74 | addend_ (addend) |
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75 | { |
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76 | } |
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77 | |
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78 | relocation::relocation () |
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79 | : sym (0), |
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80 | offset_ (0), |
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81 | info_ (0), |
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82 | addend_ (0) |
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83 | { |
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84 | } |
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85 | |
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86 | elf_addr |
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87 | relocation::offset () const |
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88 | { |
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89 | return offset_; |
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90 | } |
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91 | |
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92 | uint32_t |
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93 | relocation::type () const |
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94 | { |
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95 | return GELF_R_TYPE (info_); |
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96 | } |
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97 | |
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98 | elf_xword |
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99 | relocation::info () const |
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100 | { |
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101 | return info_; |
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102 | } |
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103 | |
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104 | elf_sxword |
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105 | relocation::addend () const |
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106 | { |
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107 | return addend_; |
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108 | } |
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109 | |
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110 | const symbols::symbol& |
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111 | relocation::symbol () const |
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112 | { |
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113 | if (sym) |
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114 | return *sym; |
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115 | throw rld::error ("no symbol", "elf:relocation"); |
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116 | } |
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117 | |
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118 | section::section (file& file_, |
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119 | int index_, |
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120 | const std::string& name_, |
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121 | elf_word type, |
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122 | elf_xword alignment, |
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123 | elf_xword flags, |
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124 | elf_addr addr, |
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125 | elf_off offset, |
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126 | elf_xword size, |
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127 | elf_word link, |
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128 | elf_word info, |
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129 | elf_xword entry_size) |
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130 | : file_ (&file_), |
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131 | index_ (index_), |
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132 | name_ (name_), |
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133 | scn (0), |
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134 | data_ (0), |
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135 | rela (false) |
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136 | { |
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137 | if (!file_.is_writable ()) |
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138 | throw rld::error ("not writable", |
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139 | "elf:section" + file_.name () + " (" + name_ + ')'); |
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140 | |
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141 | scn = ::elf_newscn (file_.get_elf ()); |
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142 | if (!scn) |
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143 | libelf_error ("elf_newscn: " + name_ + " (" + file_.name () + ')'); |
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144 | |
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145 | if (::gelf_getshdr(scn, &shdr) == 0) |
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146 | libelf_error ("gelf_getshdr: " + name_ + " (" + file_.name () + ')'); |
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147 | |
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148 | shdr.sh_name = 0; |
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149 | shdr.sh_type = type; |
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150 | shdr.sh_flags = flags; |
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151 | shdr.sh_addr = addr; |
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152 | shdr.sh_offset = offset; |
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153 | shdr.sh_size = size; |
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154 | shdr.sh_link = link; |
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155 | shdr.sh_info = info; |
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156 | shdr.sh_addralign = alignment; |
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157 | shdr.sh_entsize = entry_size; |
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158 | |
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159 | if (type == SHT_NOBITS) |
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160 | add_data (ELF_T_BYTE, alignment, size); |
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161 | |
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162 | if (!gelf_update_shdr (scn, &shdr)) |
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163 | libelf_error ("gelf_update_shdr: " + name_ + " (" + file_.name () + ')'); |
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164 | } |
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165 | |
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166 | section::section (file& file_, int index_) |
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167 | : file_ (&file_), |
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168 | index_ (index_), |
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169 | scn (0), |
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170 | data_ (0), |
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171 | rela (false) |
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172 | { |
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173 | memset (&shdr, 0, sizeof (shdr)); |
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174 | |
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175 | scn = ::elf_getscn (file_.get_elf (), index_); |
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176 | if (!scn) |
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177 | libelf_error ("elf_getscn: " + file_.name ()); |
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178 | |
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179 | if (!::gelf_getshdr (scn, &shdr)) |
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180 | libelf_error ("gelf_getshdr: " + file_.name ()); |
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181 | |
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182 | if (shdr.sh_type != SHT_NULL) |
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183 | { |
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184 | name_ = file_.get_string (shdr.sh_name); |
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185 | data_ = ::elf_getdata (scn, 0); |
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186 | if (!data_) |
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187 | { |
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188 | data_ = ::elf_rawdata (scn, 0); |
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189 | if (!data_) |
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190 | libelf_error ("elf_getdata: " + name_ + '(' + file_.name () + ')'); |
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191 | } |
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192 | } |
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193 | |
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194 | if (rld::verbose () >= RLD_VERBOSE_FULL_DEBUG) |
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195 | std::cout << "elf::section: index=" << index () |
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196 | << " name='" << name () << "'" |
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197 | << " size=" << size () |
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198 | << " align=" << alignment () |
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199 | << " flags=0x" << std::hex << flags () << std::dec |
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200 | << std::endl; |
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201 | } |
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202 | |
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203 | section::section (const section& orig) |
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204 | : file_ (orig.file_), |
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205 | index_ (orig.index_), |
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206 | name_ (orig.name_), |
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207 | scn (orig.scn), |
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208 | shdr (orig.shdr), |
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209 | data_ (orig.data_), |
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210 | rela (orig.rela), |
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211 | relocs (orig.relocs) |
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212 | { |
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213 | } |
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214 | |
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215 | section::section () |
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216 | : file_ (0), |
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217 | index_ (-1), |
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218 | scn (0), |
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219 | data_ (0), |
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220 | rela (false) |
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221 | { |
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222 | memset (&shdr, 0, sizeof (shdr)); |
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223 | } |
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224 | |
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225 | void |
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226 | section::add_data (elf_type type, |
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227 | elf_xword alignment, |
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228 | elf_xword size, |
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229 | void* buffer, |
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230 | elf_off offset) |
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231 | { |
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232 | check_writable ("add_data"); |
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233 | |
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234 | data_ = ::elf_newdata(scn); |
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235 | if (!data_) |
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236 | libelf_error ("elf_newdata: " + name_ + " (" + file_->name () + ')'); |
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237 | |
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238 | data_->d_type = type; |
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239 | data_->d_off = offset; |
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240 | data_->d_size = size; |
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241 | data_->d_align = alignment; |
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242 | data_->d_version = EV_CURRENT; |
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243 | data_->d_buf = buffer; |
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244 | |
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245 | if (!gelf_update_shdr (scn, &shdr)) |
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246 | libelf_error ("gelf_update_shdr: " + name_ + " (" + file_->name () + ')'); |
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247 | } |
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248 | |
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249 | int |
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250 | section::index () const |
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251 | { |
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252 | check ("index"); |
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253 | return index_; |
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254 | } |
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255 | |
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256 | const std::string& |
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257 | section::name () const |
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258 | { |
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259 | check ("name"); |
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260 | return name_; |
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261 | } |
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262 | |
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263 | elf_data* |
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264 | section::data () |
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265 | { |
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266 | check ("data"); |
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267 | return data_; |
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268 | } |
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269 | |
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270 | elf_word |
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271 | section::type () const |
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272 | { |
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273 | check ("type"); |
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274 | return shdr.sh_type; |
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275 | } |
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276 | |
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277 | elf_xword |
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278 | section::flags () const |
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279 | { |
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280 | check ("flags"); |
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281 | return shdr.sh_flags; |
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282 | } |
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283 | |
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284 | elf_addr |
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285 | section::address () const |
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286 | { |
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287 | check ("address"); |
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288 | return shdr.sh_addr; |
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289 | } |
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290 | |
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291 | elf_xword |
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292 | section::alignment () const |
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293 | { |
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294 | check ("alignment"); |
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295 | return shdr.sh_addralign; |
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296 | } |
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297 | |
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298 | elf_off |
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299 | section::offset () const |
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300 | { |
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301 | check ("offset"); |
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302 | return shdr.sh_offset; |
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303 | } |
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304 | |
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305 | elf_word |
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306 | section::link () const |
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307 | { |
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308 | check ("link"); |
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309 | return shdr.sh_link; |
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310 | } |
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311 | |
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312 | elf_word |
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313 | section::info () const |
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314 | { |
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315 | check ("info"); |
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316 | return shdr.sh_info; |
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317 | } |
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318 | |
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319 | elf_xword |
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320 | section::size () const |
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321 | { |
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322 | check ("size"); |
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323 | return shdr.sh_size; |
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324 | } |
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325 | |
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326 | elf_xword |
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327 | section::entry_size () const |
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328 | { |
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329 | check ("entry_size"); |
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330 | return shdr.sh_entsize; |
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331 | } |
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332 | |
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333 | int |
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334 | section::entries () const |
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335 | { |
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336 | return size () / entry_size (); |
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337 | } |
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338 | |
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339 | bool |
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340 | section::get_reloc_type () const |
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341 | { |
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342 | return rela; |
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343 | } |
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344 | |
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345 | void |
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346 | section::set_name (unsigned int index) |
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347 | { |
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348 | check_writable ("set_name"); |
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349 | shdr.sh_name = index; |
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350 | if (!gelf_update_shdr (scn, &shdr)) |
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351 | libelf_error ("gelf_update_shdr: " + name_ + " (" + file_->name () + ')'); |
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352 | } |
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353 | |
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354 | void |
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355 | section::set_reloc_type (bool rela_) |
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356 | { |
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357 | rela = rela_; |
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358 | } |
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359 | |
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360 | void |
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361 | section::add (const relocation& reloc) |
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362 | { |
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363 | relocs.push_back (reloc); |
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364 | } |
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365 | |
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366 | const relocations& |
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367 | section::get_relocations () const |
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368 | { |
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369 | return relocs; |
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370 | } |
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371 | |
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372 | void |
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373 | section::check (const char* where) const |
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374 | { |
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375 | if (!file_ || (index_ < 0) || !scn) |
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376 | { |
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377 | std::string w = where; |
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378 | throw rld::error ("Section not initialised.", "section:check:" + w); |
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379 | } |
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380 | } |
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381 | |
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382 | void |
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383 | section::check_writable (const char* where) const |
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384 | { |
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385 | check (where); |
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386 | if (!file_->is_writable ()) |
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387 | { |
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388 | std::string w = where; |
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389 | throw rld::error ("File is read-only.", "section:check:"); |
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390 | } |
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391 | } |
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392 | |
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393 | program_header::program_header () |
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394 | { |
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395 | memset (&phdr, 0, sizeof (phdr)); |
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396 | } |
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397 | |
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398 | program_header::~program_header () |
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399 | { |
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400 | } |
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401 | |
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402 | void |
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403 | program_header::set (elf_word type, |
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404 | elf_word flags, |
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405 | elf_off offset, |
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406 | elf_xword filesz, |
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407 | elf_xword memsz, |
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408 | elf_xword align, |
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409 | elf_addr vaddr, |
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410 | elf_addr paddr) |
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411 | { |
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412 | phdr.p_type = type; |
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413 | phdr.p_flags = flags; |
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414 | phdr.p_offset = offset; |
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415 | phdr.p_vaddr = vaddr; |
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416 | phdr.p_paddr = paddr; |
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417 | phdr.p_filesz = filesz; |
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418 | phdr.p_memsz = memsz; |
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419 | phdr.p_align = align; |
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420 | } |
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421 | |
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422 | file::file () |
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423 | : fd_ (-1), |
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424 | archive (false), |
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425 | writable (false), |
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426 | elf_ (0), |
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427 | oclass (0), |
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428 | ident_str (0), |
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429 | ident_size (0), |
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430 | ehdr (0), |
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431 | phdr (0) |
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432 | { |
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433 | } |
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434 | |
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435 | file::~file () |
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436 | { |
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437 | end (); |
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438 | } |
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439 | |
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440 | void |
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441 | file::begin (const std::string& name__, int fd__, const bool writable_) |
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442 | { |
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443 | begin (name__, fd__, writable_, 0, 0); |
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444 | } |
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445 | |
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446 | void |
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447 | file::begin (const std::string& name__, file& archive_, off_t offset) |
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448 | { |
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449 | archive_.check ("begin:archive"); |
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450 | |
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451 | if (archive_.writable) |
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452 | throw rld::error ("archive is writable", "elf:file:begin"); |
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453 | |
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454 | begin (name__, archive_.fd_, false, &archive_, offset); |
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455 | } |
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456 | |
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457 | #define rld_archive_fhdr_size (60) |
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458 | |
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459 | void |
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460 | file::begin (const std::string& name__, |
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461 | int fd__, |
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462 | const bool writable_, |
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463 | file* archive_, |
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464 | off_t offset_) |
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465 | { |
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466 | if (fd__ < 0) |
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467 | throw rld::error ("No file descriptor", "elf:file:begin"); |
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468 | |
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469 | /* |
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470 | * Begin's are not nesting. |
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471 | */ |
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472 | if (elf_ || (fd_ >= 0)) |
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473 | throw rld::error ("Already called", "elf:file:begin"); |
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474 | |
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475 | /* |
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476 | * Cannot write directly into archive. Create a file then archive it. |
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477 | */ |
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478 | if (archive_ && writable_) |
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479 | throw rld::error ("Cannot write into archives directly", |
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480 | "elf:file:begin"); |
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481 | |
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482 | libelf_initialise (); |
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483 | |
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484 | /* |
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485 | * Is this image part of an archive ? |
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486 | */ |
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487 | if (archive_) |
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488 | { |
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489 | ssize_t offset = offset_ - rld_archive_fhdr_size; |
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490 | if (::elf_rand (archive_->elf_, offset) != offset) |
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491 | libelf_error ("rand: " + archive_->name_); |
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492 | } |
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493 | |
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494 | /* |
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495 | * Note, the elf passed is either the archive or NULL. |
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496 | */ |
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497 | elf* elf__ = ::elf_begin (fd__, |
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498 | writable_ ? ELF_C_WRITE : ELF_C_READ, |
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499 | archive_ ? archive_->elf_ : 0); |
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500 | if (!elf__) |
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501 | libelf_error ("begin: " + name__); |
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502 | |
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503 | if (rld::verbose () >= RLD_VERBOSE_FULL_DEBUG) |
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504 | std::cout << "elf::begin: " << elf__ << ' ' << name__ << std::endl; |
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505 | |
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506 | elf_kind ek = ::elf_kind (elf__); |
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507 | |
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508 | /* |
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509 | * If this is inside an archive it must be an ELF file. |
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510 | */ |
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511 | |
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512 | if (archive_ && (ek != ELF_K_ELF)) |
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513 | throw rld::error ("File format in archive not ELF", |
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514 | "elf:file:begin: " + name__); |
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515 | else |
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516 | { |
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517 | if (ek == ELF_K_AR) |
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518 | archive = true; |
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519 | else if (ek == ELF_K_ELF) |
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520 | archive = false; |
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521 | else |
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522 | throw rld::error ("File format not ELF or archive", |
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523 | "elf:file:begin: " + name__); |
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524 | } |
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525 | |
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526 | if (!writable_) |
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527 | { |
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528 | /* |
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529 | * If an ELF file make sure they all match. On the first file that |
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530 | * begins an ELF session record its settings. |
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531 | */ |
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532 | if (ek == ELF_K_ELF) |
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533 | { |
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534 | oclass = ::gelf_getclass (elf__); |
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535 | ident_str = elf_getident (elf__, &ident_size); |
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536 | } |
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537 | } |
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538 | |
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539 | fd_ = fd__; |
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540 | name_ = name__; |
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541 | writable = writable_; |
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542 | elf_ = elf__; |
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543 | |
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544 | if (!archive && !writable) |
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545 | { |
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546 | load_header (); |
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547 | load_sections (); |
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548 | } |
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549 | } |
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550 | |
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551 | void |
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552 | file::end () |
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553 | { |
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554 | if (elf_) |
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555 | { |
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556 | if (rld::verbose () >= RLD_VERBOSE_FULL_DEBUG) |
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557 | std::cout << "libelf::end: " << elf_ |
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558 | << ' ' << name_ << std::endl; |
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559 | ::elf_end (elf_); |
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560 | elf_ = 0; |
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561 | } |
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562 | |
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563 | if (fd_ >= 0) |
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564 | { |
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565 | if (!writable) |
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566 | { |
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567 | if (ehdr) |
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568 | { |
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569 | delete ehdr; |
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570 | ehdr = 0; |
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571 | } |
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572 | if (phdr) |
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573 | { |
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574 | delete phdr; |
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575 | phdr = 0; |
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576 | } |
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577 | } |
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578 | |
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579 | fd_ = -1; |
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580 | name_.clear (); |
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581 | archive = false; |
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582 | elf_ = 0; |
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583 | oclass = 0; |
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584 | ident_str = 0; |
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585 | ident_size = 0; |
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586 | writable = false; |
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587 | secs.clear (); |
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588 | } |
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589 | } |
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590 | |
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591 | void |
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592 | file::write () |
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593 | { |
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594 | check_writable ("write"); |
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595 | |
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596 | std::string shstrtab; |
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597 | |
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598 | for (section_table::iterator sti = secs.begin (); |
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599 | sti != secs.end (); |
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600 | ++sti) |
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601 | { |
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602 | section& sec = (*sti).second; |
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603 | int added_at = shstrtab.size (); |
---|
604 | shstrtab += '\0' + sec.name (); |
---|
605 | sec.set_name (added_at + 1); |
---|
606 | } |
---|
607 | |
---|
608 | unsigned int shstrtab_name = shstrtab.size () + 1; |
---|
609 | |
---|
610 | /* |
---|
611 | * Done this way to clang happy on darwin. |
---|
612 | */ |
---|
613 | shstrtab += '\0'; |
---|
614 | shstrtab += ".shstrtab"; |
---|
615 | |
---|
616 | /* |
---|
617 | * Create the string table section. |
---|
618 | */ |
---|
619 | section shstrsec (*this, |
---|
620 | secs.size () + 1, /* index */ |
---|
621 | ".shstrtab", /* name */ |
---|
622 | SHT_STRTAB, /* type */ |
---|
623 | 1, /* alignment */ |
---|
624 | SHF_STRINGS | SHF_ALLOC, /* flags */ |
---|
625 | 0, /* address */ |
---|
626 | 0, /* offset */ |
---|
627 | shstrtab.size ()); /* size */ |
---|
628 | |
---|
629 | shstrsec.add_data (ELF_T_BYTE, |
---|
630 | 1, |
---|
631 | shstrtab.size (), |
---|
632 | (void*) shstrtab.c_str ()); |
---|
633 | |
---|
634 | shstrsec.set_name (shstrtab_name); |
---|
635 | |
---|
636 | ::elf_setshstrndx (elf_, shstrsec.index ()); |
---|
637 | ::elf_flagehdr (elf_, ELF_C_SET, ELF_F_DIRTY); |
---|
638 | |
---|
639 | if (elf_update (elf_, ELF_C_NULL) < 0) |
---|
640 | libelf_error ("elf_update:layout: " + name_); |
---|
641 | |
---|
642 | ::elf_flagphdr (elf_, ELF_C_SET, ELF_F_DIRTY); |
---|
643 | |
---|
644 | if (::elf_update (elf_, ELF_C_WRITE) < 0) |
---|
645 | libelf_error ("elf_update:write: " + name_); |
---|
646 | } |
---|
647 | |
---|
648 | void |
---|
649 | file::load_header () |
---|
650 | { |
---|
651 | check ("load_header"); |
---|
652 | |
---|
653 | if (!ehdr) |
---|
654 | { |
---|
655 | if (!writable) |
---|
656 | ehdr = new elf_ehdr; |
---|
657 | else |
---|
658 | { |
---|
659 | throw rld::error ("No ELF header; set the header first", |
---|
660 | "elf:file:load_header: " + name_); |
---|
661 | } |
---|
662 | } |
---|
663 | |
---|
664 | if (::gelf_getehdr (elf_, ehdr) == 0) |
---|
665 | error ("gelf_getehdr"); |
---|
666 | } |
---|
667 | |
---|
668 | unsigned int |
---|
669 | file::machinetype () const |
---|
670 | { |
---|
671 | check_ehdr ("machinetype"); |
---|
672 | return ehdr->e_machine; |
---|
673 | } |
---|
674 | |
---|
675 | unsigned int |
---|
676 | file::type () const |
---|
677 | { |
---|
678 | check_ehdr ("type"); |
---|
679 | return ehdr->e_type; |
---|
680 | } |
---|
681 | |
---|
682 | unsigned int |
---|
683 | file::object_class () const |
---|
684 | { |
---|
685 | check ("object_class"); |
---|
686 | return oclass; |
---|
687 | } |
---|
688 | |
---|
689 | unsigned int |
---|
690 | file::data_type () const |
---|
691 | { |
---|
692 | check ("data_type"); |
---|
693 | if (!ident_str) |
---|
694 | throw rld::error ("No ELF ident str", "elf:file:data_type: " + name_); |
---|
695 | return ident_str[EI_DATA]; |
---|
696 | } |
---|
697 | |
---|
698 | bool |
---|
699 | file::is_archive () const |
---|
700 | { |
---|
701 | check ("is_archive"); |
---|
702 | return archive; |
---|
703 | } |
---|
704 | |
---|
705 | bool |
---|
706 | file::is_executable () const |
---|
707 | { |
---|
708 | check_ehdr ("is_executable"); |
---|
709 | return ehdr->e_type != ET_REL; |
---|
710 | } |
---|
711 | |
---|
712 | bool |
---|
713 | file::is_relocatable() const |
---|
714 | { |
---|
715 | check_ehdr ("is_relocatable"); |
---|
716 | return ehdr->e_type == ET_REL; |
---|
717 | } |
---|
718 | |
---|
719 | int |
---|
720 | file::section_count () const |
---|
721 | { |
---|
722 | check_ehdr ("section_count"); |
---|
723 | return ehdr->e_shnum; |
---|
724 | } |
---|
725 | |
---|
726 | void |
---|
727 | file::load_sections () |
---|
728 | { |
---|
729 | if (secs.empty ()) |
---|
730 | { |
---|
731 | check ("load_sections_headers"); |
---|
732 | for (int sn = 0; sn < section_count (); ++sn) |
---|
733 | { |
---|
734 | section sec (*this, sn); |
---|
735 | secs[sec.name ()] = sec; |
---|
736 | } |
---|
737 | } |
---|
738 | } |
---|
739 | |
---|
740 | void |
---|
741 | file::get_sections (sections& filtered_secs, unsigned int type) |
---|
742 | { |
---|
743 | load_sections (); |
---|
744 | for (section_table::iterator si = secs.begin (); |
---|
745 | si != secs.end (); |
---|
746 | ++si) |
---|
747 | { |
---|
748 | section& sec = (*si).second; |
---|
749 | if ((type == 0) || (sec.type () == type)) |
---|
750 | filtered_secs.push_back (&sec); |
---|
751 | } |
---|
752 | } |
---|
753 | |
---|
754 | section& |
---|
755 | file::get_section (int index) |
---|
756 | { |
---|
757 | load_sections (); |
---|
758 | for (section_table::iterator si = secs.begin (); |
---|
759 | si != secs.end (); |
---|
760 | ++si) |
---|
761 | { |
---|
762 | section& sec = (*si).second; |
---|
763 | if (index == sec.index ()) |
---|
764 | return sec; |
---|
765 | } |
---|
766 | |
---|
767 | throw rld::error ("section index '" + rld::to_string (index) + "'not found", |
---|
768 | "elf:file:get_section: " + name_); |
---|
769 | } |
---|
770 | |
---|
771 | int |
---|
772 | file::strings_section () const |
---|
773 | { |
---|
774 | check_ehdr ("strings_sections"); |
---|
775 | return ehdr->e_shstrndx; |
---|
776 | } |
---|
777 | |
---|
778 | void |
---|
779 | file::load_symbols () |
---|
780 | { |
---|
781 | if (symbols.empty ()) |
---|
782 | { |
---|
783 | if (rld::verbose () >= RLD_VERBOSE_FULL_DEBUG) |
---|
784 | std::cout << "elf:symbol: " << name () << std::endl; |
---|
785 | |
---|
786 | sections symbol_secs; |
---|
787 | |
---|
788 | get_sections (symbol_secs, SHT_SYMTAB); |
---|
789 | |
---|
790 | for (sections::iterator si = symbol_secs.begin (); |
---|
791 | si != symbol_secs.end (); |
---|
792 | ++si) |
---|
793 | { |
---|
794 | section& sec = *(*si); |
---|
795 | int syms = sec.entries (); |
---|
796 | |
---|
797 | for (int s = 0; s < syms; ++s) |
---|
798 | { |
---|
799 | elf_sym esym; |
---|
800 | |
---|
801 | if (!::gelf_getsym (sec.data (), s, &esym)) |
---|
802 | error ("gelf_getsym"); |
---|
803 | |
---|
804 | std::string name = get_string (sec.link (), esym.st_name); |
---|
805 | symbols::symbol sym (s, name, esym); |
---|
806 | |
---|
807 | if (rld::verbose () >= RLD_VERBOSE_FULL_DEBUG) |
---|
808 | std::cout << "elf:symbol: " << sym << std::endl; |
---|
809 | |
---|
810 | symbols.push_back (sym); |
---|
811 | } |
---|
812 | } |
---|
813 | } |
---|
814 | } |
---|
815 | |
---|
816 | void |
---|
817 | file::get_symbols (symbols::pointers& filtered_syms, |
---|
818 | bool unresolved, |
---|
819 | bool local, |
---|
820 | bool weak, |
---|
821 | bool global) |
---|
822 | { |
---|
823 | if (rld::verbose () >= RLD_VERBOSE_TRACE_SYMS) |
---|
824 | std::cout << "elf:get-syms: unresolved:" << unresolved |
---|
825 | << " local:" << local |
---|
826 | << " weak:" << weak |
---|
827 | << " global:" << global |
---|
828 | << " " << name_ |
---|
829 | << std::endl; |
---|
830 | |
---|
831 | load_symbols (); |
---|
832 | |
---|
833 | filtered_syms.clear (); |
---|
834 | |
---|
835 | for (symbols::bucket::iterator si = symbols.begin (); |
---|
836 | si != symbols.end (); |
---|
837 | ++si) |
---|
838 | { |
---|
839 | symbols::symbol& sym = *si; |
---|
840 | |
---|
841 | int stype = sym.type (); |
---|
842 | int sbind = sym.binding (); |
---|
843 | |
---|
844 | /* |
---|
845 | * If wanting unresolved symbols and the type is no-type and the |
---|
846 | * section is undefined, or, the type is no-type or object or function |
---|
847 | * and the bind is local and we want local symbols, or the bind is weak |
---|
848 | * and we want weak symbols, or the bind is global and we want global |
---|
849 | * symbols then add the filtered symbols container. |
---|
850 | */ |
---|
851 | bool add = false; |
---|
852 | |
---|
853 | if ((stype == STT_NOTYPE) && |
---|
854 | (sbind == STB_GLOBAL) && |
---|
855 | (sym.section_index () == SHN_UNDEF)) |
---|
856 | { |
---|
857 | if (unresolved) |
---|
858 | add = true; |
---|
859 | } |
---|
860 | else |
---|
861 | { |
---|
862 | if (((stype == STT_NOTYPE) || |
---|
863 | (stype == STT_OBJECT) || |
---|
864 | (stype == STT_FUNC)) && |
---|
865 | ((weak && (sbind == STB_WEAK)) || |
---|
866 | (!unresolved && ((local && (sbind == STB_LOCAL)) || |
---|
867 | (global && (sbind == STB_GLOBAL)))))) |
---|
868 | add = true; |
---|
869 | } |
---|
870 | |
---|
871 | if (add) |
---|
872 | filtered_syms.push_back (&sym); |
---|
873 | } |
---|
874 | } |
---|
875 | |
---|
876 | const symbols::symbol& |
---|
877 | file::get_symbol (const int index) const |
---|
878 | { |
---|
879 | for (symbols::bucket::const_iterator si = symbols.begin (); |
---|
880 | si != symbols.end (); |
---|
881 | ++si) |
---|
882 | { |
---|
883 | const symbols::symbol& sym = *si; |
---|
884 | if (index == sym.index ()) |
---|
885 | return sym; |
---|
886 | } |
---|
887 | |
---|
888 | throw rld::error ("symbol index '" + rld::to_string (index) + "' not found", |
---|
889 | "elf:file:get_symbol: " + name_); |
---|
890 | } |
---|
891 | |
---|
892 | void |
---|
893 | file::load_relocations () |
---|
894 | { |
---|
895 | if (rld::verbose () >= RLD_VERBOSE_FULL_DEBUG) |
---|
896 | std::cout << "elf:reloc: " << name () << std::endl; |
---|
897 | |
---|
898 | sections rel_secs; |
---|
899 | |
---|
900 | get_sections (rel_secs, SHT_REL); |
---|
901 | get_sections (rel_secs, SHT_RELA); |
---|
902 | |
---|
903 | for (sections::iterator si = rel_secs.begin (); |
---|
904 | si != rel_secs.end (); |
---|
905 | ++si) |
---|
906 | { |
---|
907 | section& sec = *(*si); |
---|
908 | section& targetsec = get_section (sec.info ()); |
---|
909 | int rels = sec.entries (); |
---|
910 | bool rela = sec.type () == SHT_RELA; |
---|
911 | |
---|
912 | targetsec.set_reloc_type (rela); |
---|
913 | |
---|
914 | if (rld::verbose () >= RLD_VERBOSE_FULL_DEBUG) |
---|
915 | std::cout << "elf:reloc: " << sec.name () |
---|
916 | << " -> " << targetsec.name () |
---|
917 | << std::endl; |
---|
918 | |
---|
919 | for (int r = 0; r < rels; ++r) |
---|
920 | { |
---|
921 | if (rela) |
---|
922 | { |
---|
923 | elf_rela erela; |
---|
924 | |
---|
925 | if (!::gelf_getrela (sec.data (), r, &erela)) |
---|
926 | error ("gelf_getrela"); |
---|
927 | |
---|
928 | if (rld::verbose () >= RLD_VERBOSE_FULL_DEBUG) |
---|
929 | std::cout << "elf:reloc: rela: offset: " << erela.r_offset |
---|
930 | << " sym:" << GELF_R_SYM (erela.r_info) |
---|
931 | << " type:" << GELF_R_TYPE (erela.r_info) |
---|
932 | << " addend:" << erela.r_addend |
---|
933 | << std::endl; |
---|
934 | |
---|
935 | /* |
---|
936 | * The target section is updated with the fix up, and symbol |
---|
937 | * section indicates the section offset being referenced by the |
---|
938 | * fixup. |
---|
939 | */ |
---|
940 | |
---|
941 | const symbols::symbol& sym = get_symbol (GELF_R_SYM (erela.r_info)); |
---|
942 | |
---|
943 | relocation reloc (sym, |
---|
944 | erela.r_offset, |
---|
945 | erela.r_info, |
---|
946 | erela.r_addend); |
---|
947 | |
---|
948 | targetsec.add (reloc); |
---|
949 | } |
---|
950 | else |
---|
951 | { |
---|
952 | elf_rel erel; |
---|
953 | |
---|
954 | if (!::gelf_getrel (sec.data (), r, &erel)) |
---|
955 | error ("gelf_getrel"); |
---|
956 | |
---|
957 | if (rld::verbose () >= RLD_VERBOSE_FULL_DEBUG) |
---|
958 | std::cout << "elf:reloc: rel: offset: " << erel.r_offset |
---|
959 | << " sym:" << GELF_R_SYM (erel.r_info) |
---|
960 | << " type:" << GELF_R_TYPE (erel.r_info) |
---|
961 | << std::endl; |
---|
962 | |
---|
963 | const symbols::symbol& sym = get_symbol (GELF_R_SYM (erel.r_info)); |
---|
964 | |
---|
965 | relocation reloc (sym, erel.r_offset, erel.r_info); |
---|
966 | |
---|
967 | targetsec.add (reloc); |
---|
968 | } |
---|
969 | } |
---|
970 | } |
---|
971 | } |
---|
972 | |
---|
973 | std::string |
---|
974 | file::get_string (int section, size_t offset) |
---|
975 | { |
---|
976 | check ("get_string"); |
---|
977 | char* s = ::elf_strptr (elf_, section, offset); |
---|
978 | if (!s) |
---|
979 | error ("elf_strptr"); |
---|
980 | return s; |
---|
981 | } |
---|
982 | |
---|
983 | std::string |
---|
984 | file::get_string (size_t offset) |
---|
985 | { |
---|
986 | check ("get_string"); |
---|
987 | char* s = ::elf_strptr (elf_, strings_section (), offset); |
---|
988 | if (!s) |
---|
989 | error ("elf_strptr"); |
---|
990 | return s; |
---|
991 | } |
---|
992 | |
---|
993 | void |
---|
994 | file::set_header (elf_half type, |
---|
995 | int class_, |
---|
996 | elf_half machinetype, |
---|
997 | unsigned char datatype) |
---|
998 | { |
---|
999 | check_writable ("set_header"); |
---|
1000 | |
---|
1001 | if (ehdr) |
---|
1002 | throw rld::error ("ELF header already set", |
---|
1003 | "elf:file:set_header: " + name_); |
---|
1004 | |
---|
1005 | ehdr = (elf_ehdr*) ::gelf_newehdr (elf_, class_); |
---|
1006 | if (ehdr == 0) |
---|
1007 | error ("gelf_newehdr"); |
---|
1008 | |
---|
1009 | if (class_ == ELFCLASS32) |
---|
1010 | { |
---|
1011 | if((ehdr = (elf_ehdr*) ::elf32_getehdr (elf_)) == 0) |
---|
1012 | error ("elf32_getehdr"); |
---|
1013 | } |
---|
1014 | else if (::gelf_getehdr (elf_, ehdr) == 0) |
---|
1015 | error ("gelf_getehdr"); |
---|
1016 | |
---|
1017 | if (class_ == ELFCLASS32) |
---|
1018 | { |
---|
1019 | ((elf32_ehdr*)ehdr)->e_type = type; |
---|
1020 | ((elf32_ehdr*)ehdr)->e_machine = machinetype; |
---|
1021 | ((elf32_ehdr*)ehdr)->e_flags = 0; |
---|
1022 | ((elf32_ehdr*)ehdr)->e_ident[EI_DATA] = datatype; |
---|
1023 | ((elf32_ehdr*)ehdr)->e_version = EV_CURRENT; |
---|
1024 | } |
---|
1025 | else |
---|
1026 | { |
---|
1027 | ehdr->e_type = type; |
---|
1028 | ehdr->e_machine = machinetype; |
---|
1029 | ehdr->e_flags = 0; |
---|
1030 | ehdr->e_ident[EI_DATA] = datatype; |
---|
1031 | ehdr->e_version = EV_CURRENT; |
---|
1032 | } |
---|
1033 | |
---|
1034 | ::elf_flagphdr (elf_, ELF_C_SET , ELF_F_DIRTY); |
---|
1035 | } |
---|
1036 | |
---|
1037 | void |
---|
1038 | file::add (section& sec) |
---|
1039 | { |
---|
1040 | check_writable ("add"); |
---|
1041 | secs[sec.name ()] = sec; |
---|
1042 | } |
---|
1043 | |
---|
1044 | void |
---|
1045 | file::add (program_header& phdr) |
---|
1046 | { |
---|
1047 | check_writable ("add"); |
---|
1048 | phdrs.push_back (phdr); |
---|
1049 | } |
---|
1050 | |
---|
1051 | elf* |
---|
1052 | file::get_elf () |
---|
1053 | { |
---|
1054 | return elf_; |
---|
1055 | } |
---|
1056 | |
---|
1057 | const std::string& |
---|
1058 | file::name () const |
---|
1059 | { |
---|
1060 | return name_; |
---|
1061 | } |
---|
1062 | |
---|
1063 | bool |
---|
1064 | file::is_writable () const |
---|
1065 | { |
---|
1066 | return writable; |
---|
1067 | } |
---|
1068 | |
---|
1069 | void |
---|
1070 | file::check (const char* where) const |
---|
1071 | { |
---|
1072 | if (!elf_ || (fd_ < 0)) |
---|
1073 | { |
---|
1074 | std::string w = where; |
---|
1075 | throw rld::error ("No ELF file or file descriptor", "elf:file:" + w); |
---|
1076 | } |
---|
1077 | } |
---|
1078 | |
---|
1079 | void |
---|
1080 | file::check_ehdr (const char* where) const |
---|
1081 | { |
---|
1082 | check (where); |
---|
1083 | if (!ehdr) |
---|
1084 | { |
---|
1085 | std::string w = where; |
---|
1086 | throw rld::error ("no elf header", "elf:file:" + w); |
---|
1087 | } |
---|
1088 | } |
---|
1089 | |
---|
1090 | void |
---|
1091 | file::check_phdr (const char* where) const |
---|
1092 | { |
---|
1093 | check (where); |
---|
1094 | if (!phdr) |
---|
1095 | { |
---|
1096 | std::string w = where; |
---|
1097 | throw rld::error ("no elf program header", "elf:file:" + w); |
---|
1098 | } |
---|
1099 | } |
---|
1100 | |
---|
1101 | void |
---|
1102 | file::check_writable (const char* where) const |
---|
1103 | { |
---|
1104 | check (where); |
---|
1105 | if (!writable) |
---|
1106 | { |
---|
1107 | std::string w = where; |
---|
1108 | throw rld::error ("not writable", "elf:file:" + w); |
---|
1109 | } |
---|
1110 | } |
---|
1111 | |
---|
1112 | void |
---|
1113 | file::error (const char* where) const |
---|
1114 | { |
---|
1115 | std::string w = where; |
---|
1116 | libelf_error (w + ": " + name_); |
---|
1117 | } |
---|
1118 | |
---|
1119 | const std::string |
---|
1120 | machine_type (unsigned int machinetype) |
---|
1121 | { |
---|
1122 | struct types_and_labels |
---|
1123 | { |
---|
1124 | const char* name; //< The RTEMS label. |
---|
1125 | unsigned int machinetype; //< The machine type. |
---|
1126 | }; |
---|
1127 | types_and_labels types_to_labels[] = |
---|
1128 | { |
---|
1129 | { "arm", EM_ARM }, |
---|
1130 | { "avr", EM_AVR }, |
---|
1131 | { "bfin", EM_BLACKFIN }, |
---|
1132 | { "h8300", EM_H8_300 }, |
---|
1133 | { "i386", EM_386 }, |
---|
1134 | /* { "m32c", EM_M32C }, Not in libelf I imported */ |
---|
1135 | { "m32r", EM_M32R }, |
---|
1136 | { "m68k", EM_68K }, |
---|
1137 | { "m68k", EM_COLDFIRE }, |
---|
1138 | { "mips", EM_MIPS }, |
---|
1139 | { "powerpc", EM_PPC }, |
---|
1140 | { "sh", EM_SH }, |
---|
1141 | { "sparc", EM_SPARC }, |
---|
1142 | { "sparc64", EM_SPARC }, |
---|
1143 | { 0, EM_NONE } |
---|
1144 | }; |
---|
1145 | |
---|
1146 | int m = 0; |
---|
1147 | while (types_to_labels[m].machinetype != EM_NONE) |
---|
1148 | { |
---|
1149 | if (machinetype == types_to_labels[m].machinetype) |
---|
1150 | return types_to_labels[m].name; |
---|
1151 | ++m; |
---|
1152 | } |
---|
1153 | |
---|
1154 | std::ostringstream what; |
---|
1155 | what << "unknown machine type: " << elf_object_machinetype; |
---|
1156 | throw rld::error (what, "machine-type"); |
---|
1157 | } |
---|
1158 | |
---|
1159 | const std::string |
---|
1160 | machine_type () |
---|
1161 | { |
---|
1162 | return machine_type (elf_object_machinetype); |
---|
1163 | } |
---|
1164 | |
---|
1165 | unsigned int |
---|
1166 | object_class () |
---|
1167 | { |
---|
1168 | return elf_object_class; |
---|
1169 | } |
---|
1170 | |
---|
1171 | unsigned int |
---|
1172 | object_machine_type () |
---|
1173 | { |
---|
1174 | return elf_object_machinetype; |
---|
1175 | } |
---|
1176 | |
---|
1177 | unsigned int |
---|
1178 | object_datatype () |
---|
1179 | { |
---|
1180 | return elf_object_datatype; |
---|
1181 | } |
---|
1182 | |
---|
1183 | void |
---|
1184 | check_file(const file& file) |
---|
1185 | { |
---|
1186 | if (elf_object_machinetype == EM_NONE) |
---|
1187 | elf_object_machinetype = file.machinetype (); |
---|
1188 | else if (file.machinetype () != elf_object_machinetype) |
---|
1189 | { |
---|
1190 | std::ostringstream oss; |
---|
1191 | oss << "elf:check_file:" << file.name () |
---|
1192 | << ": " << elf_object_machinetype << '/' << file.machinetype (); |
---|
1193 | throw rld::error ("Mixed machine types not supported.", oss.str ()); |
---|
1194 | } |
---|
1195 | |
---|
1196 | if (elf_object_class == ELFCLASSNONE) |
---|
1197 | elf_object_class = file.object_class (); |
---|
1198 | else if (file.object_class () != elf_object_class) |
---|
1199 | throw rld::error ("Mixed classes not allowed (32bit/64bit).", |
---|
1200 | "elf:check_file: " + file.name ()); |
---|
1201 | |
---|
1202 | if (elf_object_datatype == ELFDATANONE) |
---|
1203 | elf_object_datatype = file.data_type (); |
---|
1204 | else if (elf_object_datatype != file.data_type ()) |
---|
1205 | throw rld::error ("Mixed data types not allowed (LSB/MSB).", |
---|
1206 | "elf:check_file: " + file.name ()); |
---|
1207 | } |
---|
1208 | |
---|
1209 | } |
---|
1210 | } |
---|