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1 /* |
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2 * update.c - implementation of the elf_update(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: update.c,v 1.32 2006/07/07 22:15:50 michael Exp $"; |
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24 #endif /* lint */ |
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25 |
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26 #include <errno.h> |
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27 |
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28 #if HAVE_MMAP |
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29 #include <sys/mman.h> |
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30 #endif /* HAVE_MMAP */ |
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31 |
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32 static const unsigned short __encoding = ELFDATA2LSB + (ELFDATA2MSB << 8); |
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33 #define native_encoding (*(unsigned char*)&__encoding) |
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34 |
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35 #define rewrite(var,val,f) \ |
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36 do{if((var)!=(val)){(var)=(val);(f)|=ELF_F_DIRTY;}}while(0) |
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37 |
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38 #define align(var,val) \ |
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39 do{if((val)>1){(var)+=(val)-1;(var)-=(var)%(val);}}while(0) |
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40 |
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41 #undef max |
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42 #define max(a,b) ((a)>(b)?(a):(b)) |
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43 |
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44 static off_t |
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45 scn_data_layout(Elf_Scn *scn, unsigned v, unsigned type, size_t *algn, unsigned *flag) { |
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46 Elf *elf = scn->s_elf; |
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47 Elf_Data *data; |
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48 int layout = (elf->e_elf_flags & ELF_F_LAYOUT) == 0; |
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49 size_t scn_align = 1; |
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50 size_t len = 0; |
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51 Scn_Data *sd; |
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52 size_t fsize; |
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53 |
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54 if (!(sd = scn->s_data_1)) { |
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55 /* no data in section */ |
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56 *algn = scn_align; |
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57 return (off_t)len; |
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58 } |
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59 /* load data from file, if any */ |
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60 if (!(data = elf_getdata(scn, NULL))) { |
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61 return (off_t)-1; |
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62 } |
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63 elf_assert(data == &sd->sd_data); |
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64 for (; sd; sd = sd->sd_link) { |
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65 elf_assert(sd->sd_magic == DATA_MAGIC); |
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66 elf_assert(sd->sd_scn == scn); |
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67 |
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68 if (!valid_version(sd->sd_data.d_version)) { |
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69 return (off_t)-1; |
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70 } |
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71 |
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72 fsize = sd->sd_data.d_size; |
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73 if (fsize && type != SHT_NOBITS && valid_type(sd->sd_data.d_type)) { |
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74 if (elf->e_class == ELFCLASS32) { |
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75 fsize = _elf32_xltsize(&sd->sd_data, v, ELFDATA2LSB, 1); |
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76 } |
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77 #if __LIBELF64 |
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78 else if (elf->e_class == ELFCLASS64) { |
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79 fsize = _elf64_xltsize(&sd->sd_data, v, ELFDATA2LSB, 1); |
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80 } |
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81 #endif /* __LIBELF64 */ |
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82 else { |
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83 elf_assert(valid_class(elf->e_class)); |
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84 seterr(ERROR_UNIMPLEMENTED); |
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85 return (off_t)-1; |
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86 } |
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87 if (fsize == (size_t)-1) { |
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88 return (off_t)-1; |
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89 } |
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90 } |
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91 |
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92 if (layout) { |
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93 align(len, sd->sd_data.d_align); |
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94 scn_align = max(scn_align, sd->sd_data.d_align); |
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95 rewrite(sd->sd_data.d_off, (off_t)len, sd->sd_data_flags); |
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96 len += fsize; |
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97 } |
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98 else { |
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99 len = max(len, sd->sd_data.d_off + fsize); |
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100 } |
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101 |
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102 *flag |= sd->sd_data_flags; |
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103 } |
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104 *algn = scn_align; |
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105 return (off_t)len; |
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106 } |
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107 |
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108 static size_t |
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109 scn_entsize(const Elf *elf, unsigned version, unsigned stype) { |
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110 Elf_Type type; |
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111 |
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112 switch ((type = _elf_scn_type(stype))) { |
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113 case ELF_T_BYTE: |
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114 return 0; |
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115 case ELF_T_VDEF: |
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116 case ELF_T_VNEED: |
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117 return 0; /* What else can I do? Thank you, Sun! */ |
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118 default: |
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119 return _fsize(elf->e_class, version, type); |
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120 } |
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121 } |
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122 |
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123 static off_t |
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124 _elf32_layout(Elf *elf, unsigned *flag) { |
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125 int layout = (elf->e_elf_flags & ELF_F_LAYOUT) == 0; |
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126 Elf32_Ehdr *ehdr = (Elf32_Ehdr*)elf->e_ehdr; |
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127 size_t off = 0; |
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128 unsigned version; |
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129 unsigned encoding; |
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130 size_t align_addr; |
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131 size_t entsize; |
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132 unsigned phnum; |
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133 unsigned shnum; |
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134 Elf_Scn *scn; |
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135 |
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136 *flag = elf->e_elf_flags | elf->e_phdr_flags; |
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137 |
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138 if ((version = ehdr->e_version) == EV_NONE) { |
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139 version = EV_CURRENT; |
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140 } |
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141 if (!valid_version(version)) { |
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142 seterr(ERROR_UNKNOWN_VERSION); |
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143 return -1; |
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144 } |
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145 if ((encoding = ehdr->e_ident[EI_DATA]) == ELFDATANONE) { |
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146 encoding = native_encoding; |
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147 } |
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148 if (!valid_encoding(encoding)) { |
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149 seterr(ERROR_UNKNOWN_ENCODING); |
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150 return -1; |
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151 } |
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152 entsize = _fsize(ELFCLASS32, version, ELF_T_EHDR); |
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153 elf_assert(entsize); |
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154 rewrite(ehdr->e_ehsize, entsize, elf->e_ehdr_flags); |
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155 off = entsize; |
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156 |
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157 align_addr = _fsize(ELFCLASS32, version, ELF_T_ADDR); |
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158 elf_assert(align_addr); |
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159 |
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160 if ((phnum = elf->e_phnum)) { |
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161 entsize = _fsize(ELFCLASS32, version, ELF_T_PHDR); |
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162 elf_assert(entsize); |
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163 if (layout) { |
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164 align(off, align_addr); |
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165 rewrite(ehdr->e_phoff, off, elf->e_ehdr_flags); |
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166 off += phnum * entsize; |
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167 } |
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168 else { |
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169 off = max(off, ehdr->e_phoff + phnum * entsize); |
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170 } |
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171 } |
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172 else { |
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173 entsize = 0; |
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174 if (layout) { |
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175 rewrite(ehdr->e_phoff, 0, elf->e_ehdr_flags); |
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176 } |
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177 } |
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178 if (phnum >= PN_XNUM) { |
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179 Elf_Scn *scn = elf->e_scn_1; |
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180 Elf32_Shdr *shdr = &scn->s_shdr32; |
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181 |
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182 elf_assert(scn); |
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183 elf_assert(scn->s_index == 0); |
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184 rewrite(shdr->sh_info, phnum, scn->s_shdr_flags); |
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185 *flag |= scn->s_shdr_flags; |
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186 phnum = PN_XNUM; |
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187 } |
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188 rewrite(ehdr->e_phnum, phnum, elf->e_ehdr_flags); |
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189 rewrite(ehdr->e_phentsize, entsize, elf->e_ehdr_flags); |
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190 |
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191 for (scn = elf->e_scn_1, shnum = 0; scn; scn = scn->s_link, ++shnum) { |
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192 Elf32_Shdr *shdr = &scn->s_shdr32; |
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193 size_t scn_align = 1; |
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194 off_t len; |
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195 |
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196 elf_assert(scn->s_index == shnum); |
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197 |
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198 *flag |= scn->s_scn_flags; |
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199 |
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200 if (scn->s_index == SHN_UNDEF) { |
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201 rewrite(shdr->sh_entsize, 0, scn->s_shdr_flags); |
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202 if (layout) { |
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203 rewrite(shdr->sh_offset, 0, scn->s_shdr_flags); |
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204 rewrite(shdr->sh_size, 0, scn->s_shdr_flags); |
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205 rewrite(shdr->sh_addralign, 0, scn->s_shdr_flags); |
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206 } |
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207 *flag |= scn->s_shdr_flags; |
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208 continue; |
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209 } |
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210 if (shdr->sh_type == SHT_NULL) { |
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211 *flag |= scn->s_shdr_flags; |
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212 continue; |
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213 } |
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214 |
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215 len = scn_data_layout(scn, version, shdr->sh_type, &scn_align, flag); |
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216 if (len == -1) { |
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217 return -1; |
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218 } |
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219 |
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220 /* |
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221 * Never override the program's choice. |
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222 */ |
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223 if (shdr->sh_entsize == 0) { |
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224 entsize = scn_entsize(elf, version, shdr->sh_type); |
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225 if (entsize > 1) { |
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226 rewrite(shdr->sh_entsize, entsize, scn->s_shdr_flags); |
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227 } |
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228 } |
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229 |
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230 if (layout) { |
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231 align(off, scn_align); |
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232 rewrite(shdr->sh_offset, off, scn->s_shdr_flags); |
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233 rewrite(shdr->sh_size, (size_t)len, scn->s_shdr_flags); |
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234 rewrite(shdr->sh_addralign, scn_align, scn->s_shdr_flags); |
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235 |
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236 if (shdr->sh_type != SHT_NOBITS) { |
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237 off += (size_t)len; |
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238 } |
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239 } |
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240 else if ((size_t)len > shdr->sh_size) { |
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241 seterr(ERROR_SCN2SMALL); |
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242 return -1; |
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243 } |
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244 else { |
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245 Elf_Scn *scn2; |
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246 size_t end1, end2; |
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247 |
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248 end1 = shdr->sh_offset; |
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249 if (shdr->sh_type != SHT_NOBITS) { |
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250 end1 += shdr->sh_size; |
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251 } |
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252 if (shdr->sh_offset < off) { |
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253 /* |
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254 * check for overlapping sections |
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255 */ |
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256 for (scn2 = elf->e_scn_1; scn2; scn2 = scn2->s_link) { |
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257 if (scn2 == scn) { |
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258 break; |
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259 } |
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260 end2 = scn2->s_shdr32.sh_offset; |
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261 if (scn2->s_shdr32.sh_type != SHT_NOBITS) { |
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262 end2 += scn2->s_shdr32.sh_size; |
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263 } |
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264 if (end1 > scn2->s_shdr32.sh_offset |
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265 && end2 > shdr->sh_offset) { |
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266 seterr(ERROR_SCN_OVERLAP); |
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267 return -1; |
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268 } |
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269 } |
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270 } |
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271 if (off < end1) { |
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272 off = end1; |
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273 } |
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274 } |
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275 *flag |= scn->s_shdr_flags; |
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276 } |
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277 |
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278 if (shnum) { |
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279 entsize = _fsize(ELFCLASS32, version, ELF_T_SHDR); |
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280 elf_assert(entsize); |
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281 if (layout) { |
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282 align(off, align_addr); |
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283 rewrite(ehdr->e_shoff, off, elf->e_ehdr_flags); |
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284 off += shnum * entsize; |
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285 } |
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286 else { |
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287 off = max(off, ehdr->e_shoff + shnum * entsize); |
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288 } |
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289 } |
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290 else { |
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291 entsize = 0; |
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292 if (layout) { |
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293 rewrite(ehdr->e_shoff, 0, elf->e_ehdr_flags); |
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294 } |
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295 } |
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296 if (shnum >= SHN_LORESERVE) { |
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297 Elf_Scn *scn = elf->e_scn_1; |
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298 Elf32_Shdr *shdr = &scn->s_shdr32; |
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299 |
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300 elf_assert(scn->s_index == 0); |
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301 rewrite(shdr->sh_size, shnum, scn->s_shdr_flags); |
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302 *flag |= scn->s_shdr_flags; |
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303 shnum = 0; |
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304 } |
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305 rewrite(ehdr->e_shnum, shnum, elf->e_ehdr_flags); |
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306 rewrite(ehdr->e_shentsize, entsize, elf->e_ehdr_flags); |
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307 |
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308 rewrite(ehdr->e_ident[EI_MAG0], ELFMAG0, elf->e_ehdr_flags); |
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309 rewrite(ehdr->e_ident[EI_MAG1], ELFMAG1, elf->e_ehdr_flags); |
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310 rewrite(ehdr->e_ident[EI_MAG2], ELFMAG2, elf->e_ehdr_flags); |
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311 rewrite(ehdr->e_ident[EI_MAG3], ELFMAG3, elf->e_ehdr_flags); |
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312 rewrite(ehdr->e_ident[EI_CLASS], ELFCLASS32, elf->e_ehdr_flags); |
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313 rewrite(ehdr->e_ident[EI_DATA], encoding, elf->e_ehdr_flags); |
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314 rewrite(ehdr->e_ident[EI_VERSION], version, elf->e_ehdr_flags); |
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315 rewrite(ehdr->e_version, version, elf->e_ehdr_flags); |
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316 |
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317 *flag |= elf->e_ehdr_flags; |
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318 |
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319 return off; |
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320 } |
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321 |
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322 #if __LIBELF64 |
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323 |
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324 static off_t |
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325 _elf64_layout(Elf *elf, unsigned *flag) { |
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326 int layout = (elf->e_elf_flags & ELF_F_LAYOUT) == 0; |
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327 Elf64_Ehdr *ehdr = (Elf64_Ehdr*)elf->e_ehdr; |
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328 size_t off = 0; |
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329 unsigned version; |
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330 unsigned encoding; |
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331 size_t align_addr; |
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332 size_t entsize; |
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333 unsigned phnum; |
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334 unsigned shnum; |
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335 Elf_Scn *scn; |
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336 |
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337 *flag = elf->e_elf_flags | elf->e_phdr_flags; |
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338 |
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339 if ((version = ehdr->e_version) == EV_NONE) { |
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340 version = EV_CURRENT; |
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341 } |
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342 if (!valid_version(version)) { |
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343 seterr(ERROR_UNKNOWN_VERSION); |
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344 return -1; |
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345 } |
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346 if ((encoding = ehdr->e_ident[EI_DATA]) == ELFDATANONE) { |
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347 encoding = native_encoding; |
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348 } |
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349 if (!valid_encoding(encoding)) { |
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350 seterr(ERROR_UNKNOWN_ENCODING); |
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351 return -1; |
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352 } |
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353 entsize = _fsize(ELFCLASS64, version, ELF_T_EHDR); |
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354 elf_assert(entsize); |
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355 rewrite(ehdr->e_ehsize, entsize, elf->e_ehdr_flags); |
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356 off = entsize; |
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357 |
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358 align_addr = _fsize(ELFCLASS64, version, ELF_T_ADDR); |
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359 elf_assert(align_addr); |
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360 |
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361 if ((phnum = elf->e_phnum)) { |
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362 entsize = _fsize(ELFCLASS64, version, ELF_T_PHDR); |
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363 elf_assert(entsize); |
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364 if (layout) { |
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365 align(off, align_addr); |
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366 rewrite(ehdr->e_phoff, off, elf->e_ehdr_flags); |
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367 off += phnum * entsize; |
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368 } |
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369 else { |
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370 off = max(off, ehdr->e_phoff + phnum * entsize); |
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371 } |
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372 } |
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373 else { |
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374 entsize = 0; |
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375 if (layout) { |
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376 rewrite(ehdr->e_phoff, 0, elf->e_ehdr_flags); |
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377 } |
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378 } |
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379 if (phnum >= PN_XNUM) { |
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380 Elf_Scn *scn = elf->e_scn_1; |
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381 Elf32_Shdr *shdr = &scn->s_shdr32; |
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382 |
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383 /* modify first section header, too! */ |
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384 elf_assert(scn); |
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385 elf_assert(scn->s_index == 0); |
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386 rewrite(shdr->sh_info, phnum, scn->s_shdr_flags); |
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387 *flag |= scn->s_shdr_flags; |
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388 phnum = PN_XNUM; |
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389 } |
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390 rewrite(ehdr->e_phnum, phnum, elf->e_ehdr_flags); |
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391 rewrite(ehdr->e_phentsize, entsize, elf->e_ehdr_flags); |
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392 |
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393 for (scn = elf->e_scn_1, shnum = 0; scn; scn = scn->s_link, ++shnum) { |
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394 Elf64_Shdr *shdr = &scn->s_shdr64; |
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395 size_t scn_align = 1; |
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396 off_t len; |
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397 |
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398 elf_assert(scn->s_index == shnum); |
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399 |
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400 *flag |= scn->s_scn_flags; |
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401 |
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402 if (scn->s_index == SHN_UNDEF) { |
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403 rewrite(shdr->sh_entsize, 0, scn->s_shdr_flags); |
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404 if (layout) { |
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405 rewrite(shdr->sh_offset, 0, scn->s_shdr_flags); |
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406 rewrite(shdr->sh_size, 0, scn->s_shdr_flags); |
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407 rewrite(shdr->sh_addralign, 0, scn->s_shdr_flags); |
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408 } |
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409 *flag |= scn->s_shdr_flags; |
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410 continue; |
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411 } |
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412 if (shdr->sh_type == SHT_NULL) { |
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413 *flag |= scn->s_shdr_flags; |
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414 continue; |
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415 } |
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416 |
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417 len = scn_data_layout(scn, version, shdr->sh_type, &scn_align, flag); |
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418 if (len == -1) { |
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419 return -1; |
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420 } |
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421 |
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422 /* |
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423 * Never override the program's choice. |
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424 */ |
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425 if (shdr->sh_entsize == 0) { |
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426 entsize = scn_entsize(elf, version, shdr->sh_type); |
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427 if (entsize > 1) { |
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428 rewrite(shdr->sh_entsize, entsize, scn->s_shdr_flags); |
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429 } |
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430 } |
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431 |
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432 if (layout) { |
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433 align(off, scn_align); |
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434 rewrite(shdr->sh_offset, off, scn->s_shdr_flags); |
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435 rewrite(shdr->sh_size, (size_t)len, scn->s_shdr_flags); |
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436 rewrite(shdr->sh_addralign, scn_align, scn->s_shdr_flags); |
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437 |
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438 if (shdr->sh_type != SHT_NOBITS) { |
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439 off += (size_t)len; |
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440 } |
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441 } |
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442 else if ((size_t)len > shdr->sh_size) { |
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443 seterr(ERROR_SCN2SMALL); |
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444 return -1; |
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445 } |
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446 else { |
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447 Elf_Scn *scn2; |
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448 size_t end1, end2; |
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449 |
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450 end1 = shdr->sh_offset; |
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451 if (shdr->sh_type != SHT_NOBITS) { |
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452 end1 += shdr->sh_size; |
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453 } |
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454 if (shdr->sh_offset < off) { |
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455 /* |
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456 * check for overlapping sections |
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457 */ |
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458 for (scn2 = elf->e_scn_1; scn2; scn2 = scn2->s_link) { |
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459 if (scn2 == scn) { |
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460 break; |
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461 } |
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462 end2 = scn2->s_shdr64.sh_offset; |
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463 if (scn2->s_shdr64.sh_type != SHT_NOBITS) { |
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464 end2 += scn2->s_shdr64.sh_size; |
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465 } |
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466 if (end1 > scn2->s_shdr64.sh_offset |
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467 && end2 > shdr->sh_offset) { |
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468 seterr(ERROR_SCN_OVERLAP); |
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469 return -1; |
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470 } |
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471 } |
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472 } |
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473 if (off < end1) { |
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474 off = end1; |
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475 } |
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476 } |
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477 *flag |= scn->s_shdr_flags; |
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478 } |
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479 |
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480 if (shnum) { |
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481 entsize = _fsize(ELFCLASS64, version, ELF_T_SHDR); |
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482 elf_assert(entsize); |
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483 if (layout) { |
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484 align(off, align_addr); |
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485 rewrite(ehdr->e_shoff, off, elf->e_ehdr_flags); |
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486 off += shnum * entsize; |
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487 } |
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488 else { |
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489 off = max(off, ehdr->e_shoff + shnum * entsize); |
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490 } |
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491 } |
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492 else { |
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493 entsize = 0; |
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494 if (layout) { |
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495 rewrite(ehdr->e_shoff, 0, elf->e_ehdr_flags); |
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496 } |
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497 } |
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498 if (shnum >= SHN_LORESERVE) { |
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499 Elf_Scn *scn = elf->e_scn_1; |
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500 Elf64_Shdr *shdr = &scn->s_shdr64; |
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501 |
|
502 elf_assert(scn->s_index == 0); |
|
503 rewrite(shdr->sh_size, shnum, scn->s_shdr_flags); |
|
504 *flag |= scn->s_shdr_flags; |
|
505 shnum = 0; |
|
506 } |
|
507 rewrite(ehdr->e_shnum, shnum, elf->e_ehdr_flags); |
|
508 rewrite(ehdr->e_shentsize, entsize, elf->e_ehdr_flags); |
|
509 |
|
510 rewrite(ehdr->e_ident[EI_MAG0], ELFMAG0, elf->e_ehdr_flags); |
|
511 rewrite(ehdr->e_ident[EI_MAG1], ELFMAG1, elf->e_ehdr_flags); |
|
512 rewrite(ehdr->e_ident[EI_MAG2], ELFMAG2, elf->e_ehdr_flags); |
|
513 rewrite(ehdr->e_ident[EI_MAG3], ELFMAG3, elf->e_ehdr_flags); |
|
514 rewrite(ehdr->e_ident[EI_CLASS], ELFCLASS64, elf->e_ehdr_flags); |
|
515 rewrite(ehdr->e_ident[EI_DATA], encoding, elf->e_ehdr_flags); |
|
516 rewrite(ehdr->e_ident[EI_VERSION], version, elf->e_ehdr_flags); |
|
517 rewrite(ehdr->e_version, version, elf->e_ehdr_flags); |
|
518 |
|
519 *flag |= elf->e_ehdr_flags; |
|
520 |
|
521 return off; |
|
522 } |
|
523 |
|
524 #endif /* __LIBELF64 */ |
|
525 |
|
526 #define ptrinside(p,a,l) ((p)>=(a)&&(p)<(a)+(l)) |
|
527 #define newptr(p,o,n) ((p)=((p)-(o))+(n)) |
|
528 |
|
529 static int |
|
530 _elf_update_pointers(Elf *elf, char *outbuf, size_t len) { |
|
531 Elf_Scn *scn; |
|
532 Scn_Data *sd; |
|
533 char *data, *rawdata; |
|
534 |
|
535 elf_assert(elf); |
|
536 elf_assert(elf->e_data); |
|
537 elf_assert(!elf->e_parent); |
|
538 elf_assert(!elf->e_unmap_data); |
|
539 elf_assert(elf->e_kind == ELF_K_ELF); |
|
540 elf_assert(len >= EI_NIDENT); |
|
541 |
|
542 /* resize memory images */ |
|
543 if (len <= elf->e_dsize) { |
|
544 /* don't shorten the memory image */ |
|
545 data = elf->e_data; |
|
546 } |
|
547 else if ((data = (char*)realloc(elf->e_data, len))) { |
|
548 elf->e_dsize = len; |
|
549 } |
|
550 else { |
|
551 seterr(ERROR_IO_2BIG); |
|
552 return -1; |
|
553 } |
|
554 if (elf->e_rawdata == elf->e_data) { |
|
555 /* update frozen raw image */ |
|
556 memcpy(data, outbuf, len); |
|
557 elf->e_data = elf->e_rawdata = data; |
|
558 /* cooked data is stored outside the raw image */ |
|
559 return 0; |
|
560 } |
|
561 if (elf->e_rawdata) { |
|
562 /* update raw image */ |
|
563 if (!(rawdata = (char*)realloc(elf->e_rawdata, len))) { |
|
564 seterr(ERROR_IO_2BIG); |
|
565 return -1; |
|
566 } |
|
567 memcpy(rawdata, outbuf, len); |
|
568 elf->e_rawdata = rawdata; |
|
569 } |
|
570 if (data == elf->e_data) { |
|
571 /* nothing more to do */ |
|
572 return 0; |
|
573 } |
|
574 /* adjust internal pointers */ |
|
575 for (scn = elf->e_scn_1; scn; scn = scn->s_link) { |
|
576 elf_assert(scn->s_magic == SCN_MAGIC); |
|
577 elf_assert(scn->s_elf == elf); |
|
578 if ((sd = scn->s_data_1)) { |
|
579 elf_assert(sd->sd_magic == DATA_MAGIC); |
|
580 elf_assert(sd->sd_scn == scn); |
|
581 if (sd->sd_memdata && !sd->sd_free_data) { |
|
582 elf_assert(ptrinside(sd->sd_memdata, elf->e_data, elf->e_dsize)); |
|
583 if (sd->sd_data.d_buf == sd->sd_memdata) { |
|
584 newptr(sd->sd_memdata, elf->e_data, data); |
|
585 sd->sd_data.d_buf = sd->sd_memdata; |
|
586 } |
|
587 else { |
|
588 newptr(sd->sd_memdata, elf->e_data, data); |
|
589 } |
|
590 } |
|
591 } |
|
592 if ((sd = scn->s_rawdata)) { |
|
593 elf_assert(sd->sd_magic == DATA_MAGIC); |
|
594 elf_assert(sd->sd_scn == scn); |
|
595 if (sd->sd_memdata && sd->sd_free_data) { |
|
596 size_t off, len; |
|
597 |
|
598 if (elf->e_class == ELFCLASS32) { |
|
599 off = scn->s_shdr32.sh_offset; |
|
600 len = scn->s_shdr32.sh_size; |
|
601 } |
|
602 #if __LIBELF64 |
|
603 else if (elf->e_class == ELFCLASS64) { |
|
604 off = scn->s_shdr64.sh_offset; |
|
605 len = scn->s_shdr64.sh_size; |
|
606 } |
|
607 #endif /* __LIBELF64 */ |
|
608 else { |
|
609 seterr(ERROR_UNIMPLEMENTED); |
|
610 return -1; |
|
611 } |
|
612 if (!(rawdata = (char*)realloc(sd->sd_memdata, len))) { |
|
613 seterr(ERROR_IO_2BIG); |
|
614 return -1; |
|
615 } |
|
616 memcpy(rawdata, outbuf + off, len); |
|
617 if (sd->sd_data.d_buf == sd->sd_memdata) { |
|
618 sd->sd_data.d_buf = rawdata; |
|
619 } |
|
620 sd->sd_memdata = rawdata; |
|
621 } |
|
622 } |
|
623 } |
|
624 elf->e_data = data; |
|
625 return 0; |
|
626 } |
|
627 |
|
628 #undef ptrinside |
|
629 #undef newptr |
|
630 |
|
631 static off_t |
|
632 _elf32_write(Elf *elf, char *outbuf, size_t len) { |
|
633 Elf32_Ehdr *ehdr; |
|
634 Elf32_Shdr *shdr; |
|
635 Elf_Scn *scn; |
|
636 Scn_Data *sd; |
|
637 Elf_Data src; |
|
638 Elf_Data dst; |
|
639 unsigned encode; |
|
640 |
|
641 elf_assert(len); |
|
642 elf_assert(elf->e_ehdr); |
|
643 ehdr = (Elf32_Ehdr*)elf->e_ehdr; |
|
644 encode = ehdr->e_ident[EI_DATA]; |
|
645 |
|
646 src.d_buf = ehdr; |
|
647 src.d_type = ELF_T_EHDR; |
|
648 src.d_size = _msize(ELFCLASS32, _elf_version, ELF_T_EHDR); |
|
649 src.d_version = _elf_version; |
|
650 dst.d_buf = outbuf; |
|
651 dst.d_size = ehdr->e_ehsize; |
|
652 dst.d_version = ehdr->e_version; |
|
653 if (!elf32_xlatetof(&dst, &src, encode)) { |
|
654 return -1; |
|
655 } |
|
656 |
|
657 if (elf->e_phnum) { |
|
658 src.d_buf = elf->e_phdr; |
|
659 src.d_type = ELF_T_PHDR; |
|
660 src.d_size = elf->e_phnum * _msize(ELFCLASS32, _elf_version, ELF_T_PHDR); |
|
661 src.d_version = _elf_version; |
|
662 dst.d_buf = outbuf + ehdr->e_phoff; |
|
663 dst.d_size = elf->e_phnum * ehdr->e_phentsize; |
|
664 dst.d_version = ehdr->e_version; |
|
665 if (!elf32_xlatetof(&dst, &src, encode)) { |
|
666 return -1; |
|
667 } |
|
668 } |
|
669 |
|
670 for (scn = elf->e_scn_1; scn; scn = scn->s_link) { |
|
671 elf_assert(scn->s_magic == SCN_MAGIC); |
|
672 elf_assert(scn->s_elf == elf); |
|
673 |
|
674 src.d_buf = &scn->s_uhdr; |
|
675 src.d_type = ELF_T_SHDR; |
|
676 src.d_size = _msize(ELFCLASS32, EV_CURRENT, ELF_T_SHDR); |
|
677 src.d_version = EV_CURRENT; |
|
678 dst.d_buf = outbuf + ehdr->e_shoff + scn->s_index * ehdr->e_shentsize; |
|
679 dst.d_size = ehdr->e_shentsize; |
|
680 dst.d_version = ehdr->e_version; |
|
681 if (!elf32_xlatetof(&dst, &src, encode)) { |
|
682 return -1; |
|
683 } |
|
684 |
|
685 if (scn->s_index == SHN_UNDEF) { |
|
686 continue; |
|
687 } |
|
688 shdr = &scn->s_shdr32; |
|
689 if (shdr->sh_type == SHT_NULL || shdr->sh_type == SHT_NOBITS) { |
|
690 continue; |
|
691 } |
|
692 /* XXX: this is probably no longer necessary */ |
|
693 if (scn->s_data_1 && !elf_getdata(scn, NULL)) { |
|
694 return -1; |
|
695 } |
|
696 for (sd = scn->s_data_1; sd; sd = sd->sd_link) { |
|
697 elf_assert(sd->sd_magic == DATA_MAGIC); |
|
698 elf_assert(sd->sd_scn == scn); |
|
699 src = sd->sd_data; |
|
700 if (!src.d_size) { |
|
701 continue; |
|
702 } |
|
703 if (!src.d_buf) { |
|
704 seterr(ERROR_NULLBUF); |
|
705 return -1; |
|
706 } |
|
707 dst.d_buf = outbuf + shdr->sh_offset + src.d_off; |
|
708 dst.d_size = src.d_size; |
|
709 dst.d_version = ehdr->e_version; |
|
710 if (valid_type(src.d_type)) { |
|
711 size_t tmp; |
|
712 |
|
713 tmp = _elf32_xltsize(&src, dst.d_version, ELFDATA2LSB, 1); |
|
714 if (tmp == (size_t)-1) { |
|
715 return -1; |
|
716 } |
|
717 dst.d_size = tmp; |
|
718 } |
|
719 else { |
|
720 src.d_type = ELF_T_BYTE; |
|
721 } |
|
722 if (!elf32_xlatetof(&dst, &src, encode)) { |
|
723 return -1; |
|
724 } |
|
725 } |
|
726 } |
|
727 |
|
728 /* cleanup */ |
|
729 if (elf->e_readable && _elf_update_pointers(elf, outbuf, len)) { |
|
730 return -1; |
|
731 } |
|
732 /* NOTE: ehdr is no longer valid! */ |
|
733 ehdr = (Elf32_Ehdr*)elf->e_ehdr; elf_assert(ehdr); |
|
734 elf->e_encoding = ehdr->e_ident[EI_DATA]; |
|
735 elf->e_version = ehdr->e_ident[EI_VERSION]; |
|
736 elf->e_elf_flags &= ~ELF_F_DIRTY; |
|
737 elf->e_ehdr_flags &= ~ELF_F_DIRTY; |
|
738 elf->e_phdr_flags &= ~ELF_F_DIRTY; |
|
739 for (scn = elf->e_scn_1; scn; scn = scn->s_link) { |
|
740 scn->s_scn_flags &= ~ELF_F_DIRTY; |
|
741 scn->s_shdr_flags &= ~ELF_F_DIRTY; |
|
742 for (sd = scn->s_data_1; sd; sd = sd->sd_link) { |
|
743 sd->sd_data_flags &= ~ELF_F_DIRTY; |
|
744 } |
|
745 if (elf->e_readable) { |
|
746 shdr = &scn->s_shdr32; |
|
747 scn->s_type = shdr->sh_type; |
|
748 scn->s_size = shdr->sh_size; |
|
749 scn->s_offset = shdr->sh_offset; |
|
750 } |
|
751 } |
|
752 elf->e_size = len; |
|
753 return len; |
|
754 } |
|
755 |
|
756 #if __LIBELF64 |
|
757 |
|
758 static off_t |
|
759 _elf64_write(Elf *elf, char *outbuf, size_t len) { |
|
760 Elf64_Ehdr *ehdr; |
|
761 Elf64_Shdr *shdr; |
|
762 Elf_Scn *scn; |
|
763 Scn_Data *sd; |
|
764 Elf_Data src; |
|
765 Elf_Data dst; |
|
766 unsigned encode; |
|
767 |
|
768 elf_assert(len); |
|
769 elf_assert(elf->e_ehdr); |
|
770 ehdr = (Elf64_Ehdr*)elf->e_ehdr; |
|
771 encode = ehdr->e_ident[EI_DATA]; |
|
772 |
|
773 src.d_buf = ehdr; |
|
774 src.d_type = ELF_T_EHDR; |
|
775 src.d_size = _msize(ELFCLASS64, _elf_version, ELF_T_EHDR); |
|
776 src.d_version = _elf_version; |
|
777 dst.d_buf = outbuf; |
|
778 dst.d_size = ehdr->e_ehsize; |
|
779 dst.d_version = ehdr->e_version; |
|
780 if (!elf64_xlatetof(&dst, &src, encode)) { |
|
781 return -1; |
|
782 } |
|
783 |
|
784 if (elf->e_phnum) { |
|
785 src.d_buf = elf->e_phdr; |
|
786 src.d_type = ELF_T_PHDR; |
|
787 src.d_size = elf->e_phnum * _msize(ELFCLASS64, _elf_version, ELF_T_PHDR); |
|
788 src.d_version = _elf_version; |
|
789 dst.d_buf = outbuf + ehdr->e_phoff; |
|
790 dst.d_size = elf->e_phnum * ehdr->e_phentsize; |
|
791 dst.d_version = ehdr->e_version; |
|
792 if (!elf64_xlatetof(&dst, &src, encode)) { |
|
793 return -1; |
|
794 } |
|
795 } |
|
796 |
|
797 for (scn = elf->e_scn_1; scn; scn = scn->s_link) { |
|
798 elf_assert(scn->s_magic == SCN_MAGIC); |
|
799 elf_assert(scn->s_elf == elf); |
|
800 |
|
801 src.d_buf = &scn->s_uhdr; |
|
802 src.d_type = ELF_T_SHDR; |
|
803 src.d_size = _msize(ELFCLASS64, EV_CURRENT, ELF_T_SHDR); |
|
804 src.d_version = EV_CURRENT; |
|
805 dst.d_buf = outbuf + ehdr->e_shoff + scn->s_index * ehdr->e_shentsize; |
|
806 dst.d_size = ehdr->e_shentsize; |
|
807 dst.d_version = ehdr->e_version; |
|
808 if (!elf64_xlatetof(&dst, &src, encode)) { |
|
809 return -1; |
|
810 } |
|
811 |
|
812 if (scn->s_index == SHN_UNDEF) { |
|
813 continue; |
|
814 } |
|
815 shdr = &scn->s_shdr64; |
|
816 if (shdr->sh_type == SHT_NULL || shdr->sh_type == SHT_NOBITS) { |
|
817 continue; |
|
818 } |
|
819 /* XXX: this is probably no longer necessary */ |
|
820 if (scn->s_data_1 && !elf_getdata(scn, NULL)) { |
|
821 return -1; |
|
822 } |
|
823 for (sd = scn->s_data_1; sd; sd = sd->sd_link) { |
|
824 elf_assert(sd->sd_magic == DATA_MAGIC); |
|
825 elf_assert(sd->sd_scn == scn); |
|
826 src = sd->sd_data; |
|
827 if (!src.d_size) { |
|
828 continue; |
|
829 } |
|
830 if (!src.d_buf) { |
|
831 seterr(ERROR_NULLBUF); |
|
832 return -1; |
|
833 } |
|
834 dst.d_buf = outbuf + shdr->sh_offset + src.d_off; |
|
835 dst.d_size = src.d_size; |
|
836 dst.d_version = ehdr->e_version; |
|
837 if (valid_type(src.d_type)) { |
|
838 size_t tmp; |
|
839 |
|
840 tmp = _elf64_xltsize(&src, dst.d_version, ELFDATA2LSB, 1); |
|
841 if (tmp == (size_t)-1) { |
|
842 return -1; |
|
843 } |
|
844 dst.d_size = tmp; |
|
845 } |
|
846 else { |
|
847 src.d_type = ELF_T_BYTE; |
|
848 } |
|
849 if (!elf64_xlatetof(&dst, &src, encode)) { |
|
850 return -1; |
|
851 } |
|
852 } |
|
853 } |
|
854 |
|
855 /* cleanup */ |
|
856 if (elf->e_readable && _elf_update_pointers(elf, outbuf, len)) { |
|
857 return -1; |
|
858 } |
|
859 /* NOTE: ehdr is no longer valid! */ |
|
860 ehdr = (Elf64_Ehdr*)elf->e_ehdr; elf_assert(ehdr); |
|
861 elf->e_encoding = ehdr->e_ident[EI_DATA]; |
|
862 elf->e_version = ehdr->e_ident[EI_VERSION]; |
|
863 elf->e_elf_flags &= ~ELF_F_DIRTY; |
|
864 elf->e_ehdr_flags &= ~ELF_F_DIRTY; |
|
865 elf->e_phdr_flags &= ~ELF_F_DIRTY; |
|
866 for (scn = elf->e_scn_1; scn; scn = scn->s_link) { |
|
867 scn->s_scn_flags &= ~ELF_F_DIRTY; |
|
868 scn->s_shdr_flags &= ~ELF_F_DIRTY; |
|
869 for (sd = scn->s_data_1; sd; sd = sd->sd_link) { |
|
870 sd->sd_data_flags &= ~ELF_F_DIRTY; |
|
871 } |
|
872 if (elf->e_readable) { |
|
873 shdr = &scn->s_shdr64; |
|
874 scn->s_type = shdr->sh_type; |
|
875 scn->s_size = shdr->sh_size; |
|
876 scn->s_offset = shdr->sh_offset; |
|
877 } |
|
878 } |
|
879 elf->e_size = len; |
|
880 return len; |
|
881 } |
|
882 |
|
883 #endif /* __LIBELF64 */ |
|
884 |
|
885 static int |
|
886 xwrite(int fd, char *buffer, size_t len) { |
|
887 size_t done = 0; |
|
888 size_t n; |
|
889 |
|
890 while (done < len) { |
|
891 n = write(fd, buffer + done, len - done); |
|
892 if (n == 0) { |
|
893 /* file system full */ |
|
894 return -1; |
|
895 } |
|
896 else if (n != (size_t)-1) { |
|
897 /* some bytes written, continue */ |
|
898 done += n; |
|
899 } |
|
900 else if (errno != EAGAIN && errno != EINTR) { |
|
901 /* real error */ |
|
902 return -1; |
|
903 } |
|
904 } |
|
905 return 0; |
|
906 } |
|
907 |
|
908 static off_t |
|
909 _elf_output(Elf *elf, int fd, size_t len, off_t (*_elf_write)(Elf*, char*, size_t)) { |
|
910 char *buf; |
|
911 off_t err; |
|
912 |
|
913 elf_assert(len); |
|
914 #if HAVE_FTRUNCATE |
|
915 ftruncate(fd, 0); |
|
916 #endif /* HAVE_FTRUNCATE */ |
|
917 #if HAVE_MMAP |
|
918 /* |
|
919 * Make sure the file is (at least) len bytes long |
|
920 */ |
|
921 #if HAVE_FTRUNCATE |
|
922 lseek(fd, (off_t)len, SEEK_SET); |
|
923 if (ftruncate(fd, len)) { |
|
924 #else /* HAVE_FTRUNCATE */ |
|
925 { |
|
926 #endif /* HAVE_FTRUNCATE */ |
|
927 if (lseek(fd, (off_t)len - 1, SEEK_SET) != (off_t)len - 1) { |
|
928 seterr(ERROR_IO_SEEK); |
|
929 return -1; |
|
930 } |
|
931 if (xwrite(fd, "", 1)) { |
|
932 seterr(ERROR_IO_WRITE); |
|
933 return -1; |
|
934 } |
|
935 } |
|
936 buf = (void*)mmap(NULL, len, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0); |
|
937 if (buf != (char*)-1) { |
|
938 if ((char)_elf_fill && !(elf->e_elf_flags & ELF_F_LAYOUT)) { |
|
939 memset(buf, _elf_fill, len); |
|
940 } |
|
941 err = _elf_write(elf, buf, len); |
|
942 munmap(buf, len); |
|
943 return err; |
|
944 } |
|
945 #endif /* HAVE_MMAP */ |
|
946 if (!(buf = (char*)malloc(len))) { |
|
947 seterr(ERROR_MEM_OUTBUF); |
|
948 return -1; |
|
949 } |
|
950 memset(buf, _elf_fill, len); |
|
951 err = _elf_write(elf, buf, len); |
|
952 if (err != -1 && (size_t)err == len) { |
|
953 if (lseek(fd, (off_t)0, SEEK_SET)) { |
|
954 seterr(ERROR_IO_SEEK); |
|
955 err = -1; |
|
956 } |
|
957 else if (xwrite(fd, buf, len)) { |
|
958 seterr(ERROR_IO_WRITE); |
|
959 err = -1; |
|
960 } |
|
961 } |
|
962 free(buf); |
|
963 return err; |
|
964 } |
|
965 |
|
966 off_t |
|
967 elf_update(Elf *elf, Elf_Cmd cmd) { |
|
968 unsigned flag; |
|
969 off_t len; |
|
970 |
|
971 if (!elf) { |
|
972 return -1; |
|
973 } |
|
974 elf_assert(elf->e_magic == ELF_MAGIC); |
|
975 if (cmd == ELF_C_WRITE) { |
|
976 if (!elf->e_writable) { |
|
977 seterr(ERROR_RDONLY); |
|
978 return -1; |
|
979 } |
|
980 if (elf->e_disabled) { |
|
981 seterr(ERROR_FDDISABLED); |
|
982 return -1; |
|
983 } |
|
984 } |
|
985 else if (cmd != ELF_C_NULL) { |
|
986 seterr(ERROR_INVALID_CMD); |
|
987 return -1; |
|
988 } |
|
989 |
|
990 if (!elf->e_ehdr) { |
|
991 seterr(ERROR_NOEHDR); |
|
992 } |
|
993 else if (elf->e_kind != ELF_K_ELF) { |
|
994 seterr(ERROR_NOTELF); |
|
995 } |
|
996 else if (elf->e_class == ELFCLASS32) { |
|
997 len = _elf32_layout(elf, &flag); |
|
998 if (len != -1 && cmd == ELF_C_WRITE && (flag & ELF_F_DIRTY)) { |
|
999 len = _elf_output(elf, elf->e_fd, (size_t)len, _elf32_write); |
|
1000 } |
|
1001 return len; |
|
1002 } |
|
1003 #if __LIBELF64 |
|
1004 else if (elf->e_class == ELFCLASS64) { |
|
1005 len = _elf64_layout(elf, &flag); |
|
1006 if (len != -1 && cmd == ELF_C_WRITE && (flag & ELF_F_DIRTY)) { |
|
1007 len = _elf_output(elf, elf->e_fd, (size_t)len, _elf64_write); |
|
1008 } |
|
1009 return len; |
|
1010 } |
|
1011 #endif /* __LIBELF64 */ |
|
1012 else if (valid_class(elf->e_class)) { |
|
1013 seterr(ERROR_UNIMPLEMENTED); |
|
1014 } |
|
1015 else { |
|
1016 seterr(ERROR_UNKNOWN_CLASS); |
|
1017 } |
|
1018 return -1; |
|
1019 } |