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Rev | Author | Line No. | Line |
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5197 | serge | 1 | /* .eh_frame section optimization. |
6324 | serge | 2 | Copyright (C) 2001-2015 Free Software Foundation, Inc. |
5197 | serge | 3 | Written by Jakub Jelinek |
4 | |||
5 | This file is part of BFD, the Binary File Descriptor library. |
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6 | |||
7 | This program is free software; you can redistribute it and/or modify |
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8 | it under the terms of the GNU General Public License as published by |
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9 | the Free Software Foundation; either version 3 of the License, or |
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10 | (at your option) any later version. |
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11 | |||
12 | This program is distributed in the hope that it will be useful, |
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13 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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15 | GNU General Public License for more details. |
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16 | |||
17 | You should have received a copy of the GNU General Public License |
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18 | along with this program; if not, write to the Free Software |
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19 | Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, |
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20 | MA 02110-1301, USA. */ |
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21 | |||
22 | #include "sysdep.h" |
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23 | #include "bfd.h" |
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24 | #include "libbfd.h" |
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25 | #include "elf-bfd.h" |
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26 | #include "dwarf2.h" |
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27 | |||
28 | #define EH_FRAME_HDR_SIZE 8 |
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29 | |||
30 | struct cie |
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31 | { |
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32 | unsigned int length; |
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33 | unsigned int hash; |
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34 | unsigned char version; |
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35 | unsigned char local_personality; |
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36 | char augmentation[20]; |
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37 | bfd_vma code_align; |
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38 | bfd_signed_vma data_align; |
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39 | bfd_vma ra_column; |
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40 | bfd_vma augmentation_size; |
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41 | union { |
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42 | struct elf_link_hash_entry *h; |
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6324 | serge | 43 | struct { |
44 | unsigned int bfd_id; |
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45 | unsigned int index; |
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46 | } sym; |
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5197 | serge | 47 | unsigned int reloc_index; |
48 | } personality; |
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49 | struct eh_cie_fde *cie_inf; |
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50 | unsigned char per_encoding; |
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51 | unsigned char lsda_encoding; |
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52 | unsigned char fde_encoding; |
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53 | unsigned char initial_insn_length; |
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54 | unsigned char can_make_lsda_relative; |
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55 | unsigned char initial_instructions[50]; |
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56 | }; |
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57 | |||
58 | |||
59 | |||
60 | /* If *ITER hasn't reached END yet, read the next byte into *RESULT and |
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61 | move onto the next byte. Return true on success. */ |
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62 | |||
63 | static inline bfd_boolean |
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64 | read_byte (bfd_byte **iter, bfd_byte *end, unsigned char *result) |
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65 | { |
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66 | if (*iter >= end) |
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67 | return FALSE; |
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68 | *result = *((*iter)++); |
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69 | return TRUE; |
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70 | } |
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71 | |||
72 | /* Move *ITER over LENGTH bytes, or up to END, whichever is closer. |
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73 | Return true it was possible to move LENGTH bytes. */ |
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74 | |||
75 | static inline bfd_boolean |
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76 | skip_bytes (bfd_byte **iter, bfd_byte *end, bfd_size_type length) |
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77 | { |
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78 | if ((bfd_size_type) (end - *iter) < length) |
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79 | { |
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80 | *iter = end; |
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81 | return FALSE; |
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82 | } |
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83 | *iter += length; |
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84 | return TRUE; |
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85 | } |
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86 | |||
87 | /* Move *ITER over an leb128, stopping at END. Return true if the end |
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88 | of the leb128 was found. */ |
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89 | |||
90 | static bfd_boolean |
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91 | skip_leb128 (bfd_byte **iter, bfd_byte *end) |
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92 | { |
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93 | unsigned char byte; |
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94 | do |
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95 | if (!read_byte (iter, end, &byte)) |
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96 | return FALSE; |
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97 | while (byte & 0x80); |
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98 | return TRUE; |
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99 | } |
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100 | |||
101 | /* Like skip_leb128, but treat the leb128 as an unsigned value and |
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102 | store it in *VALUE. */ |
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103 | |||
104 | static bfd_boolean |
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105 | read_uleb128 (bfd_byte **iter, bfd_byte *end, bfd_vma *value) |
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106 | { |
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107 | bfd_byte *start, *p; |
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108 | |||
109 | start = *iter; |
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110 | if (!skip_leb128 (iter, end)) |
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111 | return FALSE; |
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112 | |||
113 | p = *iter; |
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114 | *value = *--p; |
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115 | while (p > start) |
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116 | *value = (*value << 7) | (*--p & 0x7f); |
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117 | |||
118 | return TRUE; |
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119 | } |
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120 | |||
121 | /* Like read_uleb128, but for signed values. */ |
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122 | |||
123 | static bfd_boolean |
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124 | read_sleb128 (bfd_byte **iter, bfd_byte *end, bfd_signed_vma *value) |
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125 | { |
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126 | bfd_byte *start, *p; |
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127 | |||
128 | start = *iter; |
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129 | if (!skip_leb128 (iter, end)) |
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130 | return FALSE; |
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131 | |||
132 | p = *iter; |
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133 | *value = ((*--p & 0x7f) ^ 0x40) - 0x40; |
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134 | while (p > start) |
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135 | *value = (*value << 7) | (*--p & 0x7f); |
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136 | |||
137 | return TRUE; |
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138 | } |
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139 | |||
140 | /* Return 0 if either encoding is variable width, or not yet known to bfd. */ |
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141 | |||
142 | static |
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143 | int get_DW_EH_PE_width (int encoding, int ptr_size) |
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144 | { |
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145 | /* DW_EH_PE_ values of 0x60 and 0x70 weren't defined at the time .eh_frame |
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146 | was added to bfd. */ |
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147 | if ((encoding & 0x60) == 0x60) |
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148 | return 0; |
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149 | |||
150 | switch (encoding & 7) |
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151 | { |
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152 | case DW_EH_PE_udata2: return 2; |
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153 | case DW_EH_PE_udata4: return 4; |
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154 | case DW_EH_PE_udata8: return 8; |
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155 | case DW_EH_PE_absptr: return ptr_size; |
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156 | default: |
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157 | break; |
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158 | } |
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159 | |||
160 | return 0; |
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161 | } |
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162 | |||
163 | #define get_DW_EH_PE_signed(encoding) (((encoding) & DW_EH_PE_signed) != 0) |
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164 | |||
165 | /* Read a width sized value from memory. */ |
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166 | |||
167 | static bfd_vma |
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168 | read_value (bfd *abfd, bfd_byte *buf, int width, int is_signed) |
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169 | { |
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170 | bfd_vma value; |
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171 | |||
172 | switch (width) |
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173 | { |
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174 | case 2: |
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175 | if (is_signed) |
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176 | value = bfd_get_signed_16 (abfd, buf); |
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177 | else |
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178 | value = bfd_get_16 (abfd, buf); |
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179 | break; |
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180 | case 4: |
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181 | if (is_signed) |
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182 | value = bfd_get_signed_32 (abfd, buf); |
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183 | else |
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184 | value = bfd_get_32 (abfd, buf); |
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185 | break; |
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186 | case 8: |
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187 | if (is_signed) |
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188 | value = bfd_get_signed_64 (abfd, buf); |
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189 | else |
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190 | value = bfd_get_64 (abfd, buf); |
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191 | break; |
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192 | default: |
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193 | BFD_FAIL (); |
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194 | return 0; |
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195 | } |
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196 | |||
197 | return value; |
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198 | } |
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199 | |||
200 | /* Store a width sized value to memory. */ |
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201 | |||
202 | static void |
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203 | write_value (bfd *abfd, bfd_byte *buf, bfd_vma value, int width) |
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204 | { |
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205 | switch (width) |
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206 | { |
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207 | case 2: bfd_put_16 (abfd, value, buf); break; |
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208 | case 4: bfd_put_32 (abfd, value, buf); break; |
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209 | case 8: bfd_put_64 (abfd, value, buf); break; |
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210 | default: BFD_FAIL (); |
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211 | } |
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212 | } |
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213 | |||
214 | /* Return one if C1 and C2 CIEs can be merged. */ |
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215 | |||
216 | static int |
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217 | cie_eq (const void *e1, const void *e2) |
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218 | { |
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219 | const struct cie *c1 = (const struct cie *) e1; |
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220 | const struct cie *c2 = (const struct cie *) e2; |
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221 | |||
222 | if (c1->hash == c2->hash |
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223 | && c1->length == c2->length |
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224 | && c1->version == c2->version |
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225 | && c1->local_personality == c2->local_personality |
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226 | && strcmp (c1->augmentation, c2->augmentation) == 0 |
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227 | && strcmp (c1->augmentation, "eh") != 0 |
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228 | && c1->code_align == c2->code_align |
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229 | && c1->data_align == c2->data_align |
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230 | && c1->ra_column == c2->ra_column |
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231 | && c1->augmentation_size == c2->augmentation_size |
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232 | && memcmp (&c1->personality, &c2->personality, |
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233 | sizeof (c1->personality)) == 0 |
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6324 | serge | 234 | && (c1->cie_inf->u.cie.u.sec->output_section |
235 | == c2->cie_inf->u.cie.u.sec->output_section) |
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5197 | serge | 236 | && c1->per_encoding == c2->per_encoding |
237 | && c1->lsda_encoding == c2->lsda_encoding |
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238 | && c1->fde_encoding == c2->fde_encoding |
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239 | && c1->initial_insn_length == c2->initial_insn_length |
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6324 | serge | 240 | && c1->initial_insn_length <= sizeof (c1->initial_instructions) |
5197 | serge | 241 | && memcmp (c1->initial_instructions, |
242 | c2->initial_instructions, |
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243 | c1->initial_insn_length) == 0) |
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244 | return 1; |
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245 | |||
246 | return 0; |
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247 | } |
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248 | |||
249 | static hashval_t |
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250 | cie_hash (const void *e) |
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251 | { |
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252 | const struct cie *c = (const struct cie *) e; |
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253 | return c->hash; |
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254 | } |
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255 | |||
256 | static hashval_t |
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257 | cie_compute_hash (struct cie *c) |
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258 | { |
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259 | hashval_t h = 0; |
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6324 | serge | 260 | size_t len; |
5197 | serge | 261 | h = iterative_hash_object (c->length, h); |
262 | h = iterative_hash_object (c->version, h); |
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263 | h = iterative_hash (c->augmentation, strlen (c->augmentation) + 1, h); |
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264 | h = iterative_hash_object (c->code_align, h); |
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265 | h = iterative_hash_object (c->data_align, h); |
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266 | h = iterative_hash_object (c->ra_column, h); |
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267 | h = iterative_hash_object (c->augmentation_size, h); |
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268 | h = iterative_hash_object (c->personality, h); |
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6324 | serge | 269 | h = iterative_hash_object (c->cie_inf->u.cie.u.sec->output_section, h); |
5197 | serge | 270 | h = iterative_hash_object (c->per_encoding, h); |
271 | h = iterative_hash_object (c->lsda_encoding, h); |
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272 | h = iterative_hash_object (c->fde_encoding, h); |
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273 | h = iterative_hash_object (c->initial_insn_length, h); |
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6324 | serge | 274 | len = c->initial_insn_length; |
275 | if (len > sizeof (c->initial_instructions)) |
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276 | len = sizeof (c->initial_instructions); |
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277 | h = iterative_hash (c->initial_instructions, len, h); |
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5197 | serge | 278 | c->hash = h; |
279 | return h; |
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280 | } |
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281 | |||
282 | /* Return the number of extra bytes that we'll be inserting into |
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283 | ENTRY's augmentation string. */ |
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284 | |||
285 | static INLINE unsigned int |
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286 | extra_augmentation_string_bytes (struct eh_cie_fde *entry) |
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287 | { |
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288 | unsigned int size = 0; |
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289 | if (entry->cie) |
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290 | { |
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291 | if (entry->add_augmentation_size) |
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292 | size++; |
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293 | if (entry->u.cie.add_fde_encoding) |
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294 | size++; |
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295 | } |
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296 | return size; |
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297 | } |
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298 | |||
299 | /* Likewise ENTRY's augmentation data. */ |
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300 | |||
301 | static INLINE unsigned int |
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302 | extra_augmentation_data_bytes (struct eh_cie_fde *entry) |
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303 | { |
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304 | unsigned int size = 0; |
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305 | if (entry->add_augmentation_size) |
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306 | size++; |
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307 | if (entry->cie && entry->u.cie.add_fde_encoding) |
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308 | size++; |
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309 | return size; |
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310 | } |
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311 | |||
312 | /* Return the size that ENTRY will have in the output. ALIGNMENT is the |
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313 | required alignment of ENTRY in bytes. */ |
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314 | |||
315 | static unsigned int |
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316 | size_of_output_cie_fde (struct eh_cie_fde *entry, unsigned int alignment) |
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317 | { |
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318 | if (entry->removed) |
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319 | return 0; |
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320 | if (entry->size == 4) |
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321 | return 4; |
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322 | return (entry->size |
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323 | + extra_augmentation_string_bytes (entry) |
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324 | + extra_augmentation_data_bytes (entry) |
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325 | + alignment - 1) & -alignment; |
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326 | } |
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327 | |||
328 | /* Assume that the bytes between *ITER and END are CFA instructions. |
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329 | Try to move *ITER past the first instruction and return true on |
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330 | success. ENCODED_PTR_WIDTH gives the width of pointer entries. */ |
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331 | |||
332 | static bfd_boolean |
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333 | skip_cfa_op (bfd_byte **iter, bfd_byte *end, unsigned int encoded_ptr_width) |
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334 | { |
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335 | bfd_byte op; |
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336 | bfd_vma length; |
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337 | |||
338 | if (!read_byte (iter, end, &op)) |
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339 | return FALSE; |
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340 | |||
341 | switch (op & 0xc0 ? op & 0xc0 : op) |
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342 | { |
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343 | case DW_CFA_nop: |
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344 | case DW_CFA_advance_loc: |
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345 | case DW_CFA_restore: |
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346 | case DW_CFA_remember_state: |
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347 | case DW_CFA_restore_state: |
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348 | case DW_CFA_GNU_window_save: |
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349 | /* No arguments. */ |
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350 | return TRUE; |
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351 | |||
352 | case DW_CFA_offset: |
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353 | case DW_CFA_restore_extended: |
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354 | case DW_CFA_undefined: |
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355 | case DW_CFA_same_value: |
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356 | case DW_CFA_def_cfa_register: |
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357 | case DW_CFA_def_cfa_offset: |
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358 | case DW_CFA_def_cfa_offset_sf: |
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359 | case DW_CFA_GNU_args_size: |
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360 | /* One leb128 argument. */ |
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361 | return skip_leb128 (iter, end); |
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362 | |||
363 | case DW_CFA_val_offset: |
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364 | case DW_CFA_val_offset_sf: |
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365 | case DW_CFA_offset_extended: |
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366 | case DW_CFA_register: |
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367 | case DW_CFA_def_cfa: |
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368 | case DW_CFA_offset_extended_sf: |
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369 | case DW_CFA_GNU_negative_offset_extended: |
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370 | case DW_CFA_def_cfa_sf: |
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371 | /* Two leb128 arguments. */ |
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372 | return (skip_leb128 (iter, end) |
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373 | && skip_leb128 (iter, end)); |
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374 | |||
375 | case DW_CFA_def_cfa_expression: |
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376 | /* A variable-length argument. */ |
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377 | return (read_uleb128 (iter, end, &length) |
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378 | && skip_bytes (iter, end, length)); |
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379 | |||
380 | case DW_CFA_expression: |
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381 | case DW_CFA_val_expression: |
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382 | /* A leb128 followed by a variable-length argument. */ |
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383 | return (skip_leb128 (iter, end) |
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384 | && read_uleb128 (iter, end, &length) |
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385 | && skip_bytes (iter, end, length)); |
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386 | |||
387 | case DW_CFA_set_loc: |
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388 | return skip_bytes (iter, end, encoded_ptr_width); |
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389 | |||
390 | case DW_CFA_advance_loc1: |
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391 | return skip_bytes (iter, end, 1); |
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392 | |||
393 | case DW_CFA_advance_loc2: |
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394 | return skip_bytes (iter, end, 2); |
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395 | |||
396 | case DW_CFA_advance_loc4: |
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397 | return skip_bytes (iter, end, 4); |
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398 | |||
399 | case DW_CFA_MIPS_advance_loc8: |
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400 | return skip_bytes (iter, end, 8); |
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401 | |||
402 | default: |
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403 | return FALSE; |
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404 | } |
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405 | } |
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406 | |||
407 | /* Try to interpret the bytes between BUF and END as CFA instructions. |
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408 | If every byte makes sense, return a pointer to the first DW_CFA_nop |
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409 | padding byte, or END if there is no padding. Return null otherwise. |
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410 | ENCODED_PTR_WIDTH is as for skip_cfa_op. */ |
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411 | |||
412 | static bfd_byte * |
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413 | skip_non_nops (bfd_byte *buf, bfd_byte *end, unsigned int encoded_ptr_width, |
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414 | unsigned int *set_loc_count) |
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415 | { |
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416 | bfd_byte *last; |
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417 | |||
418 | last = buf; |
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419 | while (buf < end) |
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420 | if (*buf == DW_CFA_nop) |
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421 | buf++; |
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422 | else |
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423 | { |
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424 | if (*buf == DW_CFA_set_loc) |
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425 | ++*set_loc_count; |
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426 | if (!skip_cfa_op (&buf, end, encoded_ptr_width)) |
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427 | return 0; |
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428 | last = buf; |
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429 | } |
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430 | return last; |
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431 | } |
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432 | |||
433 | /* Convert absolute encoding ENCODING into PC-relative form. |
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434 | SIZE is the size of a pointer. */ |
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435 | |||
436 | static unsigned char |
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437 | make_pc_relative (unsigned char encoding, unsigned int ptr_size) |
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438 | { |
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439 | if ((encoding & 0x7f) == DW_EH_PE_absptr) |
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440 | switch (ptr_size) |
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441 | { |
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442 | case 2: |
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443 | encoding |= DW_EH_PE_sdata2; |
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444 | break; |
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445 | case 4: |
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446 | encoding |= DW_EH_PE_sdata4; |
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447 | break; |
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448 | case 8: |
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449 | encoding |= DW_EH_PE_sdata8; |
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450 | break; |
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451 | } |
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452 | return encoding | DW_EH_PE_pcrel; |
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453 | } |
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454 | |||
6324 | serge | 455 | /* Examine each .eh_frame_entry section and discard those |
456 | those that are marked SEC_EXCLUDE. */ |
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5197 | serge | 457 | |
6324 | serge | 458 | static void |
459 | bfd_elf_discard_eh_frame_entry (struct eh_frame_hdr_info *hdr_info) |
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5197 | serge | 460 | { |
6324 | serge | 461 | unsigned int i; |
462 | for (i = 0; i < hdr_info->array_count; i++) |
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463 | { |
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464 | if (hdr_info->u.compact.entries[i]->flags & SEC_EXCLUDE) |
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465 | { |
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466 | unsigned int j; |
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467 | for (j = i + 1; j < hdr_info->array_count; j++) |
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468 | hdr_info->u.compact.entries[j-1] = hdr_info->u.compact.entries[j]; |
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469 | |||
470 | hdr_info->array_count--; |
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471 | hdr_info->u.compact.entries[hdr_info->array_count] = NULL; |
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472 | i--; |
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473 | } |
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474 | } |
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475 | } |
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476 | |||
477 | /* Add a .eh_frame_entry section. */ |
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478 | |||
479 | static void |
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480 | bfd_elf_record_eh_frame_entry (struct eh_frame_hdr_info *hdr_info, |
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481 | asection *sec) |
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482 | { |
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483 | if (hdr_info->array_count == hdr_info->u.compact.allocated_entries) |
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484 | { |
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485 | if (hdr_info->u.compact.allocated_entries == 0) |
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486 | { |
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487 | hdr_info->frame_hdr_is_compact = TRUE; |
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488 | hdr_info->u.compact.allocated_entries = 2; |
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489 | hdr_info->u.compact.entries = |
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490 | bfd_malloc (hdr_info->u.compact.allocated_entries |
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491 | * sizeof (hdr_info->u.compact.entries[0])); |
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492 | } |
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493 | else |
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494 | { |
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495 | hdr_info->u.compact.allocated_entries *= 2; |
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496 | hdr_info->u.compact.entries = |
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497 | bfd_realloc (hdr_info->u.compact.entries, |
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498 | hdr_info->u.compact.allocated_entries |
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499 | * sizeof (hdr_info->u.compact.entries[0])); |
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500 | } |
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501 | |||
502 | BFD_ASSERT (hdr_info->u.compact.entries); |
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503 | } |
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504 | |||
505 | hdr_info->u.compact.entries[hdr_info->array_count++] = sec; |
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506 | } |
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507 | |||
508 | /* Parse a .eh_frame_entry section. Figure out which text section it |
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509 | references. */ |
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510 | |||
511 | bfd_boolean |
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512 | _bfd_elf_parse_eh_frame_entry (struct bfd_link_info *info, |
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513 | asection *sec, struct elf_reloc_cookie *cookie) |
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514 | { |
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515 | struct elf_link_hash_table *htab; |
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5197 | serge | 516 | struct eh_frame_hdr_info *hdr_info; |
6324 | serge | 517 | unsigned long r_symndx; |
518 | asection *text_sec; |
||
5197 | serge | 519 | |
6324 | serge | 520 | htab = elf_hash_table (info); |
521 | hdr_info = &htab->eh_info; |
||
522 | |||
523 | if (sec->size == 0 |
||
524 | || sec->sec_info_type != SEC_INFO_TYPE_NONE) |
||
525 | { |
||
526 | return TRUE; |
||
527 | } |
||
528 | |||
529 | if (sec->output_section && bfd_is_abs_section (sec->output_section)) |
||
530 | { |
||
531 | /* At least one of the sections is being discarded from the |
||
532 | link, so we should just ignore them. */ |
||
533 | return TRUE; |
||
534 | } |
||
535 | |||
536 | if (cookie->rel == cookie->relend) |
||
537 | return FALSE; |
||
538 | |||
539 | /* The first relocation is the function start. */ |
||
540 | r_symndx = cookie->rel->r_info >> cookie->r_sym_shift; |
||
541 | if (r_symndx == STN_UNDEF) |
||
542 | return FALSE; |
||
543 | |||
544 | text_sec = _bfd_elf_section_for_symbol (cookie, r_symndx, FALSE); |
||
545 | |||
546 | if (text_sec == NULL) |
||
547 | return FALSE; |
||
548 | |||
549 | elf_section_eh_frame_entry (text_sec) = sec; |
||
550 | if (text_sec->output_section |
||
551 | && bfd_is_abs_section (text_sec->output_section)) |
||
552 | sec->flags |= SEC_EXCLUDE; |
||
553 | |||
554 | sec->sec_info_type = SEC_INFO_TYPE_EH_FRAME_ENTRY; |
||
555 | elf_section_data (sec)->sec_info = text_sec; |
||
556 | bfd_elf_record_eh_frame_entry (hdr_info, sec); |
||
557 | return TRUE; |
||
5197 | serge | 558 | } |
559 | |||
560 | /* Try to parse .eh_frame section SEC, which belongs to ABFD. Store the |
||
561 | information in the section's sec_info field on success. COOKIE |
||
562 | describes the relocations in SEC. */ |
||
563 | |||
564 | void |
||
565 | _bfd_elf_parse_eh_frame (bfd *abfd, struct bfd_link_info *info, |
||
566 | asection *sec, struct elf_reloc_cookie *cookie) |
||
567 | { |
||
568 | #define REQUIRE(COND) \ |
||
569 | do \ |
||
570 | if (!(COND)) \ |
||
571 | goto free_no_table; \ |
||
572 | while (0) |
||
573 | |||
574 | bfd_byte *ehbuf = NULL, *buf, *end; |
||
575 | bfd_byte *last_fde; |
||
576 | struct eh_cie_fde *this_inf; |
||
577 | unsigned int hdr_length, hdr_id; |
||
578 | unsigned int cie_count; |
||
579 | struct cie *cie, *local_cies = NULL; |
||
580 | struct elf_link_hash_table *htab; |
||
581 | struct eh_frame_hdr_info *hdr_info; |
||
582 | struct eh_frame_sec_info *sec_info = NULL; |
||
583 | unsigned int ptr_size; |
||
584 | unsigned int num_cies; |
||
585 | unsigned int num_entries; |
||
586 | elf_gc_mark_hook_fn gc_mark_hook; |
||
587 | |||
588 | htab = elf_hash_table (info); |
||
589 | hdr_info = &htab->eh_info; |
||
590 | |||
591 | if (sec->size == 0 |
||
592 | || sec->sec_info_type != SEC_INFO_TYPE_NONE) |
||
593 | { |
||
594 | /* This file does not contain .eh_frame information. */ |
||
595 | return; |
||
596 | } |
||
597 | |||
598 | if (bfd_is_abs_section (sec->output_section)) |
||
599 | { |
||
600 | /* At least one of the sections is being discarded from the |
||
601 | link, so we should just ignore them. */ |
||
602 | return; |
||
603 | } |
||
604 | |||
605 | /* Read the frame unwind information from abfd. */ |
||
606 | |||
607 | REQUIRE (bfd_malloc_and_get_section (abfd, sec, &ehbuf)); |
||
608 | |||
609 | if (sec->size >= 4 |
||
610 | && bfd_get_32 (abfd, ehbuf) == 0 |
||
611 | && cookie->rel == cookie->relend) |
||
612 | { |
||
613 | /* Empty .eh_frame section. */ |
||
614 | free (ehbuf); |
||
615 | return; |
||
616 | } |
||
617 | |||
618 | /* If .eh_frame section size doesn't fit into int, we cannot handle |
||
619 | it (it would need to use 64-bit .eh_frame format anyway). */ |
||
620 | REQUIRE (sec->size == (unsigned int) sec->size); |
||
621 | |||
622 | ptr_size = (get_elf_backend_data (abfd) |
||
623 | ->elf_backend_eh_frame_address_size (abfd, sec)); |
||
624 | REQUIRE (ptr_size != 0); |
||
625 | |||
626 | /* Go through the section contents and work out how many FDEs and |
||
627 | CIEs there are. */ |
||
628 | buf = ehbuf; |
||
629 | end = ehbuf + sec->size; |
||
630 | num_cies = 0; |
||
631 | num_entries = 0; |
||
632 | while (buf != end) |
||
633 | { |
||
634 | num_entries++; |
||
635 | |||
636 | /* Read the length of the entry. */ |
||
637 | REQUIRE (skip_bytes (&buf, end, 4)); |
||
638 | hdr_length = bfd_get_32 (abfd, buf - 4); |
||
639 | |||
640 | /* 64-bit .eh_frame is not supported. */ |
||
641 | REQUIRE (hdr_length != 0xffffffff); |
||
642 | if (hdr_length == 0) |
||
643 | break; |
||
644 | |||
645 | REQUIRE (skip_bytes (&buf, end, 4)); |
||
646 | hdr_id = bfd_get_32 (abfd, buf - 4); |
||
647 | if (hdr_id == 0) |
||
648 | num_cies++; |
||
649 | |||
650 | REQUIRE (skip_bytes (&buf, end, hdr_length - 4)); |
||
651 | } |
||
652 | |||
653 | sec_info = (struct eh_frame_sec_info *) |
||
654 | bfd_zmalloc (sizeof (struct eh_frame_sec_info) |
||
655 | + (num_entries - 1) * sizeof (struct eh_cie_fde)); |
||
656 | REQUIRE (sec_info); |
||
657 | |||
658 | /* We need to have a "struct cie" for each CIE in this section. */ |
||
659 | local_cies = (struct cie *) bfd_zmalloc (num_cies * sizeof (*local_cies)); |
||
660 | REQUIRE (local_cies); |
||
661 | |||
662 | /* FIXME: octets_per_byte. */ |
||
663 | #define ENSURE_NO_RELOCS(buf) \ |
||
6324 | serge | 664 | while (cookie->rel < cookie->relend \ |
5197 | serge | 665 | && (cookie->rel->r_offset \ |
6324 | serge | 666 | < (bfd_size_type) ((buf) - ehbuf))) \ |
667 | { \ |
||
668 | REQUIRE (cookie->rel->r_info == 0); \ |
||
669 | cookie->rel++; \ |
||
670 | } |
||
5197 | serge | 671 | |
672 | /* FIXME: octets_per_byte. */ |
||
673 | #define SKIP_RELOCS(buf) \ |
||
674 | while (cookie->rel < cookie->relend \ |
||
675 | && (cookie->rel->r_offset \ |
||
676 | < (bfd_size_type) ((buf) - ehbuf))) \ |
||
677 | cookie->rel++ |
||
678 | |||
679 | /* FIXME: octets_per_byte. */ |
||
680 | #define GET_RELOC(buf) \ |
||
681 | ((cookie->rel < cookie->relend \ |
||
682 | && (cookie->rel->r_offset \ |
||
683 | == (bfd_size_type) ((buf) - ehbuf))) \ |
||
684 | ? cookie->rel : NULL) |
||
685 | |||
686 | buf = ehbuf; |
||
687 | cie_count = 0; |
||
688 | gc_mark_hook = get_elf_backend_data (abfd)->gc_mark_hook; |
||
689 | while ((bfd_size_type) (buf - ehbuf) != sec->size) |
||
690 | { |
||
691 | char *aug; |
||
692 | bfd_byte *start, *insns, *insns_end; |
||
693 | bfd_size_type length; |
||
694 | unsigned int set_loc_count; |
||
695 | |||
696 | this_inf = sec_info->entry + sec_info->count; |
||
697 | last_fde = buf; |
||
698 | |||
699 | /* Read the length of the entry. */ |
||
700 | REQUIRE (skip_bytes (&buf, ehbuf + sec->size, 4)); |
||
701 | hdr_length = bfd_get_32 (abfd, buf - 4); |
||
702 | |||
703 | /* The CIE/FDE must be fully contained in this input section. */ |
||
704 | REQUIRE ((bfd_size_type) (buf - ehbuf) + hdr_length <= sec->size); |
||
705 | end = buf + hdr_length; |
||
706 | |||
707 | this_inf->offset = last_fde - ehbuf; |
||
708 | this_inf->size = 4 + hdr_length; |
||
709 | this_inf->reloc_index = cookie->rel - cookie->rels; |
||
710 | |||
711 | if (hdr_length == 0) |
||
712 | { |
||
713 | /* A zero-length CIE should only be found at the end of |
||
714 | the section. */ |
||
715 | REQUIRE ((bfd_size_type) (buf - ehbuf) == sec->size); |
||
716 | ENSURE_NO_RELOCS (buf); |
||
717 | sec_info->count++; |
||
718 | break; |
||
719 | } |
||
720 | |||
721 | REQUIRE (skip_bytes (&buf, end, 4)); |
||
722 | hdr_id = bfd_get_32 (abfd, buf - 4); |
||
723 | |||
724 | if (hdr_id == 0) |
||
725 | { |
||
726 | unsigned int initial_insn_length; |
||
727 | |||
728 | /* CIE */ |
||
729 | this_inf->cie = 1; |
||
730 | |||
731 | /* Point CIE to one of the section-local cie structures. */ |
||
732 | cie = local_cies + cie_count++; |
||
733 | |||
734 | cie->cie_inf = this_inf; |
||
735 | cie->length = hdr_length; |
||
736 | start = buf; |
||
737 | REQUIRE (read_byte (&buf, end, &cie->version)); |
||
738 | |||
739 | /* Cannot handle unknown versions. */ |
||
740 | REQUIRE (cie->version == 1 |
||
741 | || cie->version == 3 |
||
742 | || cie->version == 4); |
||
743 | REQUIRE (strlen ((char *) buf) < sizeof (cie->augmentation)); |
||
744 | |||
745 | strcpy (cie->augmentation, (char *) buf); |
||
746 | buf = (bfd_byte *) strchr ((char *) buf, '\0') + 1; |
||
747 | ENSURE_NO_RELOCS (buf); |
||
748 | if (buf[0] == 'e' && buf[1] == 'h') |
||
749 | { |
||
750 | /* GCC < 3.0 .eh_frame CIE */ |
||
751 | /* We cannot merge "eh" CIEs because __EXCEPTION_TABLE__ |
||
752 | is private to each CIE, so we don't need it for anything. |
||
753 | Just skip it. */ |
||
754 | REQUIRE (skip_bytes (&buf, end, ptr_size)); |
||
755 | SKIP_RELOCS (buf); |
||
756 | } |
||
757 | if (cie->version >= 4) |
||
758 | { |
||
759 | REQUIRE (buf + 1 < end); |
||
760 | REQUIRE (buf[0] == ptr_size); |
||
761 | REQUIRE (buf[1] == 0); |
||
762 | buf += 2; |
||
763 | } |
||
764 | REQUIRE (read_uleb128 (&buf, end, &cie->code_align)); |
||
765 | REQUIRE (read_sleb128 (&buf, end, &cie->data_align)); |
||
766 | if (cie->version == 1) |
||
767 | { |
||
768 | REQUIRE (buf < end); |
||
769 | cie->ra_column = *buf++; |
||
770 | } |
||
771 | else |
||
772 | REQUIRE (read_uleb128 (&buf, end, &cie->ra_column)); |
||
773 | ENSURE_NO_RELOCS (buf); |
||
774 | cie->lsda_encoding = DW_EH_PE_omit; |
||
775 | cie->fde_encoding = DW_EH_PE_omit; |
||
776 | cie->per_encoding = DW_EH_PE_omit; |
||
777 | aug = cie->augmentation; |
||
778 | if (aug[0] != 'e' || aug[1] != 'h') |
||
779 | { |
||
780 | if (*aug == 'z') |
||
781 | { |
||
782 | aug++; |
||
783 | REQUIRE (read_uleb128 (&buf, end, &cie->augmentation_size)); |
||
784 | ENSURE_NO_RELOCS (buf); |
||
785 | } |
||
786 | |||
787 | while (*aug != '\0') |
||
788 | switch (*aug++) |
||
789 | { |
||
790 | case 'L': |
||
791 | REQUIRE (read_byte (&buf, end, &cie->lsda_encoding)); |
||
792 | ENSURE_NO_RELOCS (buf); |
||
793 | REQUIRE (get_DW_EH_PE_width (cie->lsda_encoding, ptr_size)); |
||
794 | break; |
||
795 | case 'R': |
||
796 | REQUIRE (read_byte (&buf, end, &cie->fde_encoding)); |
||
797 | ENSURE_NO_RELOCS (buf); |
||
798 | REQUIRE (get_DW_EH_PE_width (cie->fde_encoding, ptr_size)); |
||
799 | break; |
||
800 | case 'S': |
||
801 | break; |
||
802 | case 'P': |
||
803 | { |
||
804 | int per_width; |
||
805 | |||
806 | REQUIRE (read_byte (&buf, end, &cie->per_encoding)); |
||
807 | per_width = get_DW_EH_PE_width (cie->per_encoding, |
||
808 | ptr_size); |
||
809 | REQUIRE (per_width); |
||
810 | if ((cie->per_encoding & 0x70) == DW_EH_PE_aligned) |
||
811 | { |
||
812 | length = -(buf - ehbuf) & (per_width - 1); |
||
813 | REQUIRE (skip_bytes (&buf, end, length)); |
||
814 | } |
||
815 | this_inf->u.cie.personality_offset = buf - start; |
||
816 | ENSURE_NO_RELOCS (buf); |
||
817 | /* Ensure we have a reloc here. */ |
||
818 | REQUIRE (GET_RELOC (buf)); |
||
819 | cie->personality.reloc_index |
||
820 | = cookie->rel - cookie->rels; |
||
821 | /* Cope with MIPS-style composite relocations. */ |
||
822 | do |
||
823 | cookie->rel++; |
||
824 | while (GET_RELOC (buf) != NULL); |
||
825 | REQUIRE (skip_bytes (&buf, end, per_width)); |
||
826 | } |
||
827 | break; |
||
828 | default: |
||
829 | /* Unrecognized augmentation. Better bail out. */ |
||
830 | goto free_no_table; |
||
831 | } |
||
832 | } |
||
833 | |||
834 | /* For shared libraries, try to get rid of as many RELATIVE relocs |
||
835 | as possible. */ |
||
6324 | serge | 836 | if (bfd_link_pic (info) |
5197 | serge | 837 | && (get_elf_backend_data (abfd) |
838 | ->elf_backend_can_make_relative_eh_frame |
||
839 | (abfd, info, sec))) |
||
840 | { |
||
841 | if ((cie->fde_encoding & 0x70) == DW_EH_PE_absptr) |
||
842 | this_inf->make_relative = 1; |
||
843 | /* If the CIE doesn't already have an 'R' entry, it's fairly |
||
844 | easy to add one, provided that there's no aligned data |
||
845 | after the augmentation string. */ |
||
846 | else if (cie->fde_encoding == DW_EH_PE_omit |
||
847 | && (cie->per_encoding & 0x70) != DW_EH_PE_aligned) |
||
848 | { |
||
849 | if (*cie->augmentation == 0) |
||
850 | this_inf->add_augmentation_size = 1; |
||
851 | this_inf->u.cie.add_fde_encoding = 1; |
||
852 | this_inf->make_relative = 1; |
||
853 | } |
||
854 | |||
855 | if ((cie->lsda_encoding & 0x70) == DW_EH_PE_absptr) |
||
856 | cie->can_make_lsda_relative = 1; |
||
857 | } |
||
858 | |||
859 | /* If FDE encoding was not specified, it defaults to |
||
860 | DW_EH_absptr. */ |
||
861 | if (cie->fde_encoding == DW_EH_PE_omit) |
||
862 | cie->fde_encoding = DW_EH_PE_absptr; |
||
863 | |||
864 | initial_insn_length = end - buf; |
||
865 | cie->initial_insn_length = initial_insn_length; |
||
6324 | serge | 866 | memcpy (cie->initial_instructions, buf, |
867 | initial_insn_length <= sizeof (cie->initial_instructions) |
||
868 | ? initial_insn_length : sizeof (cie->initial_instructions)); |
||
5197 | serge | 869 | insns = buf; |
870 | buf += initial_insn_length; |
||
871 | ENSURE_NO_RELOCS (buf); |
||
872 | |||
6324 | serge | 873 | if (!bfd_link_relocatable (info)) |
874 | { |
||
875 | /* Keep info for merging cies. */ |
||
5197 | serge | 876 | this_inf->u.cie.u.full_cie = cie; |
877 | this_inf->u.cie.per_encoding_relative |
||
878 | = (cie->per_encoding & 0x70) == DW_EH_PE_pcrel; |
||
879 | } |
||
6324 | serge | 880 | } |
5197 | serge | 881 | else |
882 | { |
||
883 | /* Find the corresponding CIE. */ |
||
884 | unsigned int cie_offset = this_inf->offset + 4 - hdr_id; |
||
885 | for (cie = local_cies; cie < local_cies + cie_count; cie++) |
||
886 | if (cie_offset == cie->cie_inf->offset) |
||
887 | break; |
||
888 | |||
889 | /* Ensure this FDE references one of the CIEs in this input |
||
890 | section. */ |
||
891 | REQUIRE (cie != local_cies + cie_count); |
||
892 | this_inf->u.fde.cie_inf = cie->cie_inf; |
||
893 | this_inf->make_relative = cie->cie_inf->make_relative; |
||
894 | this_inf->add_augmentation_size |
||
895 | = cie->cie_inf->add_augmentation_size; |
||
896 | |||
897 | ENSURE_NO_RELOCS (buf); |
||
898 | if ((sec->flags & SEC_LINKER_CREATED) == 0 || cookie->rels != NULL) |
||
899 | { |
||
900 | asection *rsec; |
||
901 | |||
902 | REQUIRE (GET_RELOC (buf)); |
||
903 | |||
904 | /* Chain together the FDEs for each section. */ |
||
6324 | serge | 905 | rsec = _bfd_elf_gc_mark_rsec (info, sec, gc_mark_hook, |
906 | cookie, NULL); |
||
5197 | serge | 907 | /* RSEC will be NULL if FDE was cleared out as it was belonging to |
908 | a discarded SHT_GROUP. */ |
||
909 | if (rsec) |
||
910 | { |
||
911 | REQUIRE (rsec->owner == abfd); |
||
912 | this_inf->u.fde.next_for_section = elf_fde_list (rsec); |
||
913 | elf_fde_list (rsec) = this_inf; |
||
914 | } |
||
915 | } |
||
916 | |||
917 | /* Skip the initial location and address range. */ |
||
918 | start = buf; |
||
919 | length = get_DW_EH_PE_width (cie->fde_encoding, ptr_size); |
||
920 | REQUIRE (skip_bytes (&buf, end, 2 * length)); |
||
921 | |||
6324 | serge | 922 | SKIP_RELOCS (buf - length); |
923 | if (!GET_RELOC (buf - length) |
||
924 | && read_value (abfd, buf - length, length, FALSE) == 0) |
||
925 | { |
||
926 | (*info->callbacks->minfo) |
||
927 | (_("discarding zero address range FDE in %B(%A).\n"), |
||
928 | abfd, sec); |
||
929 | this_inf->u.fde.cie_inf = NULL; |
||
930 | } |
||
931 | |||
5197 | serge | 932 | /* Skip the augmentation size, if present. */ |
933 | if (cie->augmentation[0] == 'z') |
||
934 | REQUIRE (read_uleb128 (&buf, end, &length)); |
||
935 | else |
||
936 | length = 0; |
||
937 | |||
938 | /* Of the supported augmentation characters above, only 'L' |
||
939 | adds augmentation data to the FDE. This code would need to |
||
940 | be adjusted if any future augmentations do the same thing. */ |
||
941 | if (cie->lsda_encoding != DW_EH_PE_omit) |
||
942 | { |
||
943 | SKIP_RELOCS (buf); |
||
944 | if (cie->can_make_lsda_relative && GET_RELOC (buf)) |
||
945 | cie->cie_inf->u.cie.make_lsda_relative = 1; |
||
946 | this_inf->lsda_offset = buf - start; |
||
947 | /* If there's no 'z' augmentation, we don't know where the |
||
948 | CFA insns begin. Assume no padding. */ |
||
949 | if (cie->augmentation[0] != 'z') |
||
950 | length = end - buf; |
||
951 | } |
||
952 | |||
953 | /* Skip over the augmentation data. */ |
||
954 | REQUIRE (skip_bytes (&buf, end, length)); |
||
955 | insns = buf; |
||
956 | |||
957 | buf = last_fde + 4 + hdr_length; |
||
958 | |||
959 | /* For NULL RSEC (cleared FDE belonging to a discarded section) |
||
960 | the relocations are commonly cleared. We do not sanity check if |
||
961 | all these relocations are cleared as (1) relocations to |
||
962 | .gcc_except_table will remain uncleared (they will get dropped |
||
963 | with the drop of this unused FDE) and (2) BFD already safely drops |
||
964 | relocations of any type to .eh_frame by |
||
965 | elf_section_ignore_discarded_relocs. |
||
966 | TODO: The .gcc_except_table entries should be also filtered as |
||
967 | .eh_frame entries; or GCC could rather use COMDAT for them. */ |
||
968 | SKIP_RELOCS (buf); |
||
969 | } |
||
970 | |||
971 | /* Try to interpret the CFA instructions and find the first |
||
972 | padding nop. Shrink this_inf's size so that it doesn't |
||
973 | include the padding. */ |
||
974 | length = get_DW_EH_PE_width (cie->fde_encoding, ptr_size); |
||
975 | set_loc_count = 0; |
||
976 | insns_end = skip_non_nops (insns, end, length, &set_loc_count); |
||
977 | /* If we don't understand the CFA instructions, we can't know |
||
978 | what needs to be adjusted there. */ |
||
979 | if (insns_end == NULL |
||
980 | /* For the time being we don't support DW_CFA_set_loc in |
||
981 | CIE instructions. */ |
||
982 | || (set_loc_count && this_inf->cie)) |
||
983 | goto free_no_table; |
||
984 | this_inf->size -= end - insns_end; |
||
985 | if (insns_end != end && this_inf->cie) |
||
986 | { |
||
987 | cie->initial_insn_length -= end - insns_end; |
||
988 | cie->length -= end - insns_end; |
||
989 | } |
||
990 | if (set_loc_count |
||
991 | && ((cie->fde_encoding & 0x70) == DW_EH_PE_pcrel |
||
992 | || this_inf->make_relative)) |
||
993 | { |
||
994 | unsigned int cnt; |
||
995 | bfd_byte *p; |
||
996 | |||
997 | this_inf->set_loc = (unsigned int *) |
||
998 | bfd_malloc ((set_loc_count + 1) * sizeof (unsigned int)); |
||
999 | REQUIRE (this_inf->set_loc); |
||
1000 | this_inf->set_loc[0] = set_loc_count; |
||
1001 | p = insns; |
||
1002 | cnt = 0; |
||
1003 | while (p < end) |
||
1004 | { |
||
1005 | if (*p == DW_CFA_set_loc) |
||
1006 | this_inf->set_loc[++cnt] = p + 1 - start; |
||
1007 | REQUIRE (skip_cfa_op (&p, end, length)); |
||
1008 | } |
||
1009 | } |
||
1010 | |||
1011 | this_inf->removed = 1; |
||
1012 | this_inf->fde_encoding = cie->fde_encoding; |
||
1013 | this_inf->lsda_encoding = cie->lsda_encoding; |
||
1014 | sec_info->count++; |
||
1015 | } |
||
1016 | BFD_ASSERT (sec_info->count == num_entries); |
||
1017 | BFD_ASSERT (cie_count == num_cies); |
||
1018 | |||
1019 | elf_section_data (sec)->sec_info = sec_info; |
||
1020 | sec->sec_info_type = SEC_INFO_TYPE_EH_FRAME; |
||
6324 | serge | 1021 | if (!bfd_link_relocatable (info)) |
5197 | serge | 1022 | { |
6324 | serge | 1023 | /* Keep info for merging cies. */ |
5197 | serge | 1024 | sec_info->cies = local_cies; |
1025 | local_cies = NULL; |
||
1026 | } |
||
1027 | goto success; |
||
1028 | |||
1029 | free_no_table: |
||
1030 | (*info->callbacks->einfo) |
||
1031 | (_("%P: error in %B(%A); no .eh_frame_hdr table will be created.\n"), |
||
1032 | abfd, sec); |
||
6324 | serge | 1033 | hdr_info->u.dwarf.table = FALSE; |
5197 | serge | 1034 | if (sec_info) |
1035 | free (sec_info); |
||
1036 | success: |
||
1037 | if (ehbuf) |
||
1038 | free (ehbuf); |
||
1039 | if (local_cies) |
||
1040 | free (local_cies); |
||
1041 | #undef REQUIRE |
||
1042 | } |
||
1043 | |||
6324 | serge | 1044 | /* Order eh_frame_hdr entries by the VMA of their text section. */ |
5197 | serge | 1045 | |
6324 | serge | 1046 | static int |
1047 | cmp_eh_frame_hdr (const void *a, const void *b) |
||
1048 | { |
||
1049 | bfd_vma text_a; |
||
1050 | bfd_vma text_b; |
||
1051 | asection *sec; |
||
1052 | |||
1053 | sec = *(asection *const *)a; |
||
1054 | sec = (asection *) elf_section_data (sec)->sec_info; |
||
1055 | text_a = sec->output_section->vma + sec->output_offset; |
||
1056 | sec = *(asection *const *)b; |
||
1057 | sec = (asection *) elf_section_data (sec)->sec_info; |
||
1058 | text_b = sec->output_section->vma + sec->output_offset; |
||
1059 | |||
1060 | if (text_a < text_b) |
||
1061 | return -1; |
||
1062 | return text_a > text_b; |
||
1063 | |||
1064 | } |
||
1065 | |||
1066 | /* Add space for a CANTUNWIND terminator to SEC if the text sections |
||
1067 | referenced by it and NEXT are not contiguous, or NEXT is NULL. */ |
||
1068 | |||
1069 | static void |
||
1070 | add_eh_frame_hdr_terminator (asection *sec, |
||
1071 | asection *next) |
||
1072 | { |
||
1073 | bfd_vma end; |
||
1074 | bfd_vma next_start; |
||
1075 | asection *text_sec; |
||
1076 | |||
1077 | if (next) |
||
1078 | { |
||
1079 | /* See if there is a gap (presumably a text section without unwind info) |
||
1080 | between these two entries. */ |
||
1081 | text_sec = (asection *) elf_section_data (sec)->sec_info; |
||
1082 | end = text_sec->output_section->vma + text_sec->output_offset |
||
1083 | + text_sec->size; |
||
1084 | text_sec = (asection *) elf_section_data (next)->sec_info; |
||
1085 | next_start = text_sec->output_section->vma + text_sec->output_offset; |
||
1086 | if (end == next_start) |
||
1087 | return; |
||
1088 | } |
||
1089 | |||
1090 | /* Add space for a CANTUNWIND terminator. */ |
||
1091 | if (!sec->rawsize) |
||
1092 | sec->rawsize = sec->size; |
||
1093 | |||
1094 | bfd_set_section_size (sec->owner, sec, sec->size + 8); |
||
1095 | } |
||
1096 | |||
1097 | /* Finish a pass over all .eh_frame_entry sections. */ |
||
1098 | |||
1099 | bfd_boolean |
||
5197 | serge | 1100 | _bfd_elf_end_eh_frame_parsing (struct bfd_link_info *info) |
1101 | { |
||
1102 | struct eh_frame_hdr_info *hdr_info; |
||
6324 | serge | 1103 | unsigned int i; |
5197 | serge | 1104 | |
1105 | hdr_info = &elf_hash_table (info)->eh_info; |
||
6324 | serge | 1106 | |
1107 | if (info->eh_frame_hdr_type != COMPACT_EH_HDR |
||
1108 | || hdr_info->array_count == 0) |
||
1109 | return FALSE; |
||
1110 | |||
1111 | bfd_elf_discard_eh_frame_entry (hdr_info); |
||
1112 | |||
1113 | qsort (hdr_info->u.compact.entries, hdr_info->array_count, |
||
1114 | sizeof (asection *), cmp_eh_frame_hdr); |
||
1115 | |||
1116 | for (i = 0; i < hdr_info->array_count - 1; i++) |
||
1117 | { |
||
1118 | add_eh_frame_hdr_terminator (hdr_info->u.compact.entries[i], |
||
1119 | hdr_info->u.compact.entries[i + 1]); |
||
1120 | } |
||
1121 | |||
1122 | /* Add a CANTUNWIND terminator after the last entry. */ |
||
1123 | add_eh_frame_hdr_terminator (hdr_info->u.compact.entries[i], NULL); |
||
1124 | return TRUE; |
||
5197 | serge | 1125 | } |
1126 | |||
1127 | /* Mark all relocations against CIE or FDE ENT, which occurs in |
||
1128 | .eh_frame section SEC. COOKIE describes the relocations in SEC; |
||
1129 | its "rel" field can be changed freely. */ |
||
1130 | |||
1131 | static bfd_boolean |
||
1132 | mark_entry (struct bfd_link_info *info, asection *sec, |
||
1133 | struct eh_cie_fde *ent, elf_gc_mark_hook_fn gc_mark_hook, |
||
1134 | struct elf_reloc_cookie *cookie) |
||
1135 | { |
||
1136 | /* FIXME: octets_per_byte. */ |
||
1137 | for (cookie->rel = cookie->rels + ent->reloc_index; |
||
1138 | cookie->rel < cookie->relend |
||
1139 | && cookie->rel->r_offset < ent->offset + ent->size; |
||
1140 | cookie->rel++) |
||
1141 | if (!_bfd_elf_gc_mark_reloc (info, sec, gc_mark_hook, cookie)) |
||
1142 | return FALSE; |
||
1143 | |||
1144 | return TRUE; |
||
1145 | } |
||
1146 | |||
1147 | /* Mark all the relocations against FDEs that relate to code in input |
||
1148 | section SEC. The FDEs belong to .eh_frame section EH_FRAME, whose |
||
1149 | relocations are described by COOKIE. */ |
||
1150 | |||
1151 | bfd_boolean |
||
1152 | _bfd_elf_gc_mark_fdes (struct bfd_link_info *info, asection *sec, |
||
1153 | asection *eh_frame, elf_gc_mark_hook_fn gc_mark_hook, |
||
1154 | struct elf_reloc_cookie *cookie) |
||
1155 | { |
||
1156 | struct eh_cie_fde *fde, *cie; |
||
1157 | |||
1158 | for (fde = elf_fde_list (sec); fde; fde = fde->u.fde.next_for_section) |
||
1159 | { |
||
1160 | if (!mark_entry (info, eh_frame, fde, gc_mark_hook, cookie)) |
||
1161 | return FALSE; |
||
1162 | |||
1163 | /* At this stage, all cie_inf fields point to local CIEs, so we |
||
1164 | can use the same cookie to refer to them. */ |
||
1165 | cie = fde->u.fde.cie_inf; |
||
6324 | serge | 1166 | if (cie != NULL && !cie->u.cie.gc_mark) |
5197 | serge | 1167 | { |
1168 | cie->u.cie.gc_mark = 1; |
||
1169 | if (!mark_entry (info, eh_frame, cie, gc_mark_hook, cookie)) |
||
1170 | return FALSE; |
||
1171 | } |
||
1172 | } |
||
1173 | return TRUE; |
||
1174 | } |
||
1175 | |||
1176 | /* Input section SEC of ABFD is an .eh_frame section that contains the |
||
1177 | CIE described by CIE_INF. Return a version of CIE_INF that is going |
||
1178 | to be kept in the output, adding CIE_INF to the output if necessary. |
||
1179 | |||
1180 | HDR_INFO is the .eh_frame_hdr information and COOKIE describes the |
||
1181 | relocations in REL. */ |
||
1182 | |||
1183 | static struct eh_cie_fde * |
||
1184 | find_merged_cie (bfd *abfd, struct bfd_link_info *info, asection *sec, |
||
1185 | struct eh_frame_hdr_info *hdr_info, |
||
1186 | struct elf_reloc_cookie *cookie, |
||
1187 | struct eh_cie_fde *cie_inf) |
||
1188 | { |
||
1189 | unsigned long r_symndx; |
||
1190 | struct cie *cie, *new_cie; |
||
1191 | Elf_Internal_Rela *rel; |
||
1192 | void **loc; |
||
1193 | |||
1194 | /* Use CIE_INF if we have already decided to keep it. */ |
||
1195 | if (!cie_inf->removed) |
||
1196 | return cie_inf; |
||
1197 | |||
1198 | /* If we have merged CIE_INF with another CIE, use that CIE instead. */ |
||
1199 | if (cie_inf->u.cie.merged) |
||
1200 | return cie_inf->u.cie.u.merged_with; |
||
1201 | |||
1202 | cie = cie_inf->u.cie.u.full_cie; |
||
1203 | |||
1204 | /* Assume we will need to keep CIE_INF. */ |
||
1205 | cie_inf->removed = 0; |
||
1206 | cie_inf->u.cie.u.sec = sec; |
||
1207 | |||
1208 | /* If we are not merging CIEs, use CIE_INF. */ |
||
1209 | if (cie == NULL) |
||
1210 | return cie_inf; |
||
1211 | |||
1212 | if (cie->per_encoding != DW_EH_PE_omit) |
||
1213 | { |
||
1214 | bfd_boolean per_binds_local; |
||
1215 | |||
6324 | serge | 1216 | /* Work out the address of personality routine, or at least |
1217 | enough info that we could calculate the address had we made a |
||
1218 | final section layout. The symbol on the reloc is enough, |
||
1219 | either the hash for a global, or (bfd id, index) pair for a |
||
1220 | local. The assumption here is that no one uses addends on |
||
1221 | the reloc. */ |
||
5197 | serge | 1222 | rel = cookie->rels + cie->personality.reloc_index; |
1223 | memset (&cie->personality, 0, sizeof (cie->personality)); |
||
1224 | #ifdef BFD64 |
||
1225 | if (elf_elfheader (abfd)->e_ident[EI_CLASS] == ELFCLASS64) |
||
1226 | r_symndx = ELF64_R_SYM (rel->r_info); |
||
1227 | else |
||
1228 | #endif |
||
1229 | r_symndx = ELF32_R_SYM (rel->r_info); |
||
1230 | if (r_symndx >= cookie->locsymcount |
||
1231 | || ELF_ST_BIND (cookie->locsyms[r_symndx].st_info) != STB_LOCAL) |
||
1232 | { |
||
1233 | struct elf_link_hash_entry *h; |
||
1234 | |||
1235 | r_symndx -= cookie->extsymoff; |
||
1236 | h = cookie->sym_hashes[r_symndx]; |
||
1237 | |||
1238 | while (h->root.type == bfd_link_hash_indirect |
||
1239 | || h->root.type == bfd_link_hash_warning) |
||
1240 | h = (struct elf_link_hash_entry *) h->root.u.i.link; |
||
1241 | |||
1242 | cie->personality.h = h; |
||
1243 | per_binds_local = SYMBOL_REFERENCES_LOCAL (info, h); |
||
1244 | } |
||
1245 | else |
||
1246 | { |
||
1247 | Elf_Internal_Sym *sym; |
||
1248 | asection *sym_sec; |
||
1249 | |||
1250 | sym = &cookie->locsyms[r_symndx]; |
||
1251 | sym_sec = bfd_section_from_elf_index (abfd, sym->st_shndx); |
||
1252 | if (sym_sec == NULL) |
||
1253 | return cie_inf; |
||
1254 | |||
1255 | if (sym_sec->kept_section != NULL) |
||
1256 | sym_sec = sym_sec->kept_section; |
||
1257 | if (sym_sec->output_section == NULL) |
||
1258 | return cie_inf; |
||
1259 | |||
1260 | cie->local_personality = 1; |
||
6324 | serge | 1261 | cie->personality.sym.bfd_id = abfd->id; |
1262 | cie->personality.sym.index = r_symndx; |
||
5197 | serge | 1263 | per_binds_local = TRUE; |
1264 | } |
||
1265 | |||
1266 | if (per_binds_local |
||
6324 | serge | 1267 | && bfd_link_pic (info) |
5197 | serge | 1268 | && (cie->per_encoding & 0x70) == DW_EH_PE_absptr |
1269 | && (get_elf_backend_data (abfd) |
||
1270 | ->elf_backend_can_make_relative_eh_frame (abfd, info, sec))) |
||
1271 | { |
||
1272 | cie_inf->u.cie.make_per_encoding_relative = 1; |
||
1273 | cie_inf->u.cie.per_encoding_relative = 1; |
||
1274 | } |
||
1275 | } |
||
1276 | |||
1277 | /* See if we can merge this CIE with an earlier one. */ |
||
1278 | cie_compute_hash (cie); |
||
6324 | serge | 1279 | if (hdr_info->u.dwarf.cies == NULL) |
5197 | serge | 1280 | { |
6324 | serge | 1281 | hdr_info->u.dwarf.cies = htab_try_create (1, cie_hash, cie_eq, free); |
1282 | if (hdr_info->u.dwarf.cies == NULL) |
||
5197 | serge | 1283 | return cie_inf; |
1284 | } |
||
6324 | serge | 1285 | loc = htab_find_slot_with_hash (hdr_info->u.dwarf.cies, cie, |
1286 | cie->hash, INSERT); |
||
5197 | serge | 1287 | if (loc == NULL) |
1288 | return cie_inf; |
||
1289 | |||
1290 | new_cie = (struct cie *) *loc; |
||
1291 | if (new_cie == NULL) |
||
1292 | { |
||
1293 | /* Keep CIE_INF and record it in the hash table. */ |
||
1294 | new_cie = (struct cie *) malloc (sizeof (struct cie)); |
||
1295 | if (new_cie == NULL) |
||
1296 | return cie_inf; |
||
1297 | |||
1298 | memcpy (new_cie, cie, sizeof (struct cie)); |
||
1299 | *loc = new_cie; |
||
1300 | } |
||
1301 | else |
||
1302 | { |
||
1303 | /* Merge CIE_INF with NEW_CIE->CIE_INF. */ |
||
1304 | cie_inf->removed = 1; |
||
1305 | cie_inf->u.cie.merged = 1; |
||
1306 | cie_inf->u.cie.u.merged_with = new_cie->cie_inf; |
||
1307 | if (cie_inf->u.cie.make_lsda_relative) |
||
1308 | new_cie->cie_inf->u.cie.make_lsda_relative = 1; |
||
1309 | } |
||
1310 | return new_cie->cie_inf; |
||
1311 | } |
||
1312 | |||
1313 | /* This function is called for each input file before the .eh_frame |
||
1314 | section is relocated. It discards duplicate CIEs and FDEs for discarded |
||
1315 | functions. The function returns TRUE iff any entries have been |
||
1316 | deleted. */ |
||
1317 | |||
1318 | bfd_boolean |
||
1319 | _bfd_elf_discard_section_eh_frame |
||
1320 | (bfd *abfd, struct bfd_link_info *info, asection *sec, |
||
1321 | bfd_boolean (*reloc_symbol_deleted_p) (bfd_vma, void *), |
||
1322 | struct elf_reloc_cookie *cookie) |
||
1323 | { |
||
1324 | struct eh_cie_fde *ent; |
||
1325 | struct eh_frame_sec_info *sec_info; |
||
1326 | struct eh_frame_hdr_info *hdr_info; |
||
1327 | unsigned int ptr_size, offset; |
||
1328 | |||
1329 | if (sec->sec_info_type != SEC_INFO_TYPE_EH_FRAME) |
||
1330 | return FALSE; |
||
1331 | |||
1332 | sec_info = (struct eh_frame_sec_info *) elf_section_data (sec)->sec_info; |
||
1333 | if (sec_info == NULL) |
||
1334 | return FALSE; |
||
1335 | |||
1336 | ptr_size = (get_elf_backend_data (sec->owner) |
||
1337 | ->elf_backend_eh_frame_address_size (sec->owner, sec)); |
||
1338 | |||
1339 | hdr_info = &elf_hash_table (info)->eh_info; |
||
1340 | for (ent = sec_info->entry; ent < sec_info->entry + sec_info->count; ++ent) |
||
1341 | if (ent->size == 4) |
||
1342 | /* There should only be one zero terminator, on the last input |
||
1343 | file supplying .eh_frame (crtend.o). Remove any others. */ |
||
1344 | ent->removed = sec->map_head.s != NULL; |
||
6324 | serge | 1345 | else if (!ent->cie && ent->u.fde.cie_inf != NULL) |
5197 | serge | 1346 | { |
1347 | bfd_boolean keep; |
||
1348 | if ((sec->flags & SEC_LINKER_CREATED) != 0 && cookie->rels == NULL) |
||
1349 | { |
||
1350 | unsigned int width |
||
1351 | = get_DW_EH_PE_width (ent->fde_encoding, ptr_size); |
||
1352 | bfd_vma value |
||
1353 | = read_value (abfd, sec->contents + ent->offset + 8 + width, |
||
1354 | width, get_DW_EH_PE_signed (ent->fde_encoding)); |
||
1355 | keep = value != 0; |
||
1356 | } |
||
1357 | else |
||
1358 | { |
||
1359 | cookie->rel = cookie->rels + ent->reloc_index; |
||
1360 | /* FIXME: octets_per_byte. */ |
||
1361 | BFD_ASSERT (cookie->rel < cookie->relend |
||
1362 | && cookie->rel->r_offset == ent->offset + 8); |
||
1363 | keep = !(*reloc_symbol_deleted_p) (ent->offset + 8, cookie); |
||
1364 | } |
||
1365 | if (keep) |
||
1366 | { |
||
6324 | serge | 1367 | if (bfd_link_pic (info) |
5197 | serge | 1368 | && (((ent->fde_encoding & 0x70) == DW_EH_PE_absptr |
1369 | && ent->make_relative == 0) |
||
1370 | || (ent->fde_encoding & 0x70) == DW_EH_PE_aligned)) |
||
1371 | { |
||
1372 | /* If a shared library uses absolute pointers |
||
1373 | which we cannot turn into PC relative, |
||
1374 | don't create the binary search table, |
||
1375 | since it is affected by runtime relocations. */ |
||
6324 | serge | 1376 | hdr_info->u.dwarf.table = FALSE; |
5197 | serge | 1377 | (*info->callbacks->einfo) |
6324 | serge | 1378 | (_("%P: FDE encoding in %B(%A) prevents .eh_frame_hdr" |
5197 | serge | 1379 | " table being created.\n"), abfd, sec); |
1380 | } |
||
1381 | ent->removed = 0; |
||
6324 | serge | 1382 | hdr_info->u.dwarf.fde_count++; |
5197 | serge | 1383 | ent->u.fde.cie_inf = find_merged_cie (abfd, info, sec, hdr_info, |
1384 | cookie, ent->u.fde.cie_inf); |
||
1385 | } |
||
1386 | } |
||
1387 | |||
1388 | if (sec_info->cies) |
||
1389 | { |
||
1390 | free (sec_info->cies); |
||
1391 | sec_info->cies = NULL; |
||
1392 | } |
||
1393 | |||
1394 | offset = 0; |
||
1395 | for (ent = sec_info->entry; ent < sec_info->entry + sec_info->count; ++ent) |
||
1396 | if (!ent->removed) |
||
1397 | { |
||
1398 | ent->new_offset = offset; |
||
1399 | offset += size_of_output_cie_fde (ent, ptr_size); |
||
1400 | } |
||
1401 | |||
1402 | sec->rawsize = sec->size; |
||
1403 | sec->size = offset; |
||
1404 | return offset != sec->rawsize; |
||
1405 | } |
||
1406 | |||
1407 | /* This function is called for .eh_frame_hdr section after |
||
1408 | _bfd_elf_discard_section_eh_frame has been called on all .eh_frame |
||
1409 | input sections. It finalizes the size of .eh_frame_hdr section. */ |
||
1410 | |||
1411 | bfd_boolean |
||
1412 | _bfd_elf_discard_section_eh_frame_hdr (bfd *abfd, struct bfd_link_info *info) |
||
1413 | { |
||
1414 | struct elf_link_hash_table *htab; |
||
1415 | struct eh_frame_hdr_info *hdr_info; |
||
1416 | asection *sec; |
||
1417 | |||
1418 | htab = elf_hash_table (info); |
||
1419 | hdr_info = &htab->eh_info; |
||
1420 | |||
6324 | serge | 1421 | if (!hdr_info->frame_hdr_is_compact && hdr_info->u.dwarf.cies != NULL) |
5197 | serge | 1422 | { |
6324 | serge | 1423 | htab_delete (hdr_info->u.dwarf.cies); |
1424 | hdr_info->u.dwarf.cies = NULL; |
||
5197 | serge | 1425 | } |
1426 | |||
1427 | sec = hdr_info->hdr_sec; |
||
1428 | if (sec == NULL) |
||
1429 | return FALSE; |
||
1430 | |||
6324 | serge | 1431 | if (info->eh_frame_hdr_type == COMPACT_EH_HDR) |
1432 | { |
||
1433 | /* For compact frames we only add the header. The actual table comes |
||
1434 | from the .eh_frame_entry sections. */ |
||
1435 | sec->size = 8; |
||
1436 | } |
||
1437 | else |
||
1438 | { |
||
5197 | serge | 1439 | sec->size = EH_FRAME_HDR_SIZE; |
6324 | serge | 1440 | if (hdr_info->u.dwarf.table) |
1441 | sec->size += 4 + hdr_info->u.dwarf.fde_count * 8; |
||
1442 | } |
||
5197 | serge | 1443 | |
1444 | elf_eh_frame_hdr (abfd) = sec; |
||
1445 | return TRUE; |
||
1446 | } |
||
1447 | |||
1448 | /* Return true if there is at least one non-empty .eh_frame section in |
||
1449 | input files. Can only be called after ld has mapped input to |
||
1450 | output sections, and before sections are stripped. */ |
||
6324 | serge | 1451 | |
5197 | serge | 1452 | bfd_boolean |
1453 | _bfd_elf_eh_frame_present (struct bfd_link_info *info) |
||
1454 | { |
||
1455 | asection *eh = bfd_get_section_by_name (info->output_bfd, ".eh_frame"); |
||
1456 | |||
1457 | if (eh == NULL) |
||
1458 | return FALSE; |
||
1459 | |||
1460 | /* Count only sections which have at least a single CIE or FDE. |
||
1461 | There cannot be any CIE or FDE <= 8 bytes. */ |
||
1462 | for (eh = eh->map_head.s; eh != NULL; eh = eh->map_head.s) |
||
1463 | if (eh->size > 8) |
||
1464 | return TRUE; |
||
1465 | |||
1466 | return FALSE; |
||
1467 | } |
||
1468 | |||
6324 | serge | 1469 | /* Return true if there is at least one .eh_frame_entry section in |
1470 | input files. */ |
||
1471 | |||
1472 | bfd_boolean |
||
1473 | _bfd_elf_eh_frame_entry_present (struct bfd_link_info *info) |
||
1474 | { |
||
1475 | asection *o; |
||
1476 | bfd *abfd; |
||
1477 | |||
1478 | for (abfd = info->input_bfds; abfd != NULL; abfd = abfd->link.next) |
||
1479 | { |
||
1480 | for (o = abfd->sections; o; o = o->next) |
||
1481 | { |
||
1482 | const char *name = bfd_get_section_name (abfd, o); |
||
1483 | |||
1484 | if (strcmp (name, ".eh_frame_entry") |
||
1485 | && !bfd_is_abs_section (o->output_section)) |
||
1486 | return TRUE; |
||
1487 | } |
||
1488 | } |
||
1489 | return FALSE; |
||
1490 | } |
||
1491 | |||
5197 | serge | 1492 | /* This function is called from size_dynamic_sections. |
1493 | It needs to decide whether .eh_frame_hdr should be output or not, |
||
1494 | because when the dynamic symbol table has been sized it is too late |
||
1495 | to strip sections. */ |
||
1496 | |||
1497 | bfd_boolean |
||
1498 | _bfd_elf_maybe_strip_eh_frame_hdr (struct bfd_link_info *info) |
||
1499 | { |
||
1500 | struct elf_link_hash_table *htab; |
||
1501 | struct eh_frame_hdr_info *hdr_info; |
||
6324 | serge | 1502 | struct bfd_link_hash_entry *bh = NULL; |
1503 | struct elf_link_hash_entry *h; |
||
5197 | serge | 1504 | |
1505 | htab = elf_hash_table (info); |
||
1506 | hdr_info = &htab->eh_info; |
||
1507 | if (hdr_info->hdr_sec == NULL) |
||
1508 | return TRUE; |
||
1509 | |||
1510 | if (bfd_is_abs_section (hdr_info->hdr_sec->output_section) |
||
6324 | serge | 1511 | || info->eh_frame_hdr_type == 0 |
1512 | || (info->eh_frame_hdr_type == DWARF2_EH_HDR |
||
1513 | && !_bfd_elf_eh_frame_present (info)) |
||
1514 | || (info->eh_frame_hdr_type == COMPACT_EH_HDR |
||
1515 | && !_bfd_elf_eh_frame_entry_present (info))) |
||
5197 | serge | 1516 | { |
1517 | hdr_info->hdr_sec->flags |= SEC_EXCLUDE; |
||
1518 | hdr_info->hdr_sec = NULL; |
||
1519 | return TRUE; |
||
1520 | } |
||
1521 | |||
6324 | serge | 1522 | /* Add a hidden symbol so that systems without access to PHDRs can |
1523 | find the table. */ |
||
1524 | if (! (_bfd_generic_link_add_one_symbol |
||
1525 | (info, info->output_bfd, "__GNU_EH_FRAME_HDR", BSF_LOCAL, |
||
1526 | hdr_info->hdr_sec, 0, NULL, FALSE, FALSE, &bh))) |
||
1527 | return FALSE; |
||
1528 | |||
1529 | h = (struct elf_link_hash_entry *) bh; |
||
1530 | h->def_regular = 1; |
||
1531 | h->other = STV_HIDDEN; |
||
1532 | get_elf_backend_data |
||
1533 | (info->output_bfd)->elf_backend_hide_symbol (info, h, TRUE); |
||
1534 | |||
1535 | if (!hdr_info->frame_hdr_is_compact) |
||
1536 | hdr_info->u.dwarf.table = TRUE; |
||
5197 | serge | 1537 | return TRUE; |
1538 | } |
||
1539 | |||
1540 | /* Adjust an address in the .eh_frame section. Given OFFSET within |
||
1541 | SEC, this returns the new offset in the adjusted .eh_frame section, |
||
1542 | or -1 if the address refers to a CIE/FDE which has been removed |
||
1543 | or to offset with dynamic relocation which is no longer needed. */ |
||
1544 | |||
1545 | bfd_vma |
||
1546 | _bfd_elf_eh_frame_section_offset (bfd *output_bfd ATTRIBUTE_UNUSED, |
||
1547 | struct bfd_link_info *info ATTRIBUTE_UNUSED, |
||
1548 | asection *sec, |
||
1549 | bfd_vma offset) |
||
1550 | { |
||
1551 | struct eh_frame_sec_info *sec_info; |
||
1552 | unsigned int lo, hi, mid; |
||
1553 | |||
1554 | if (sec->sec_info_type != SEC_INFO_TYPE_EH_FRAME) |
||
1555 | return offset; |
||
1556 | sec_info = (struct eh_frame_sec_info *) elf_section_data (sec)->sec_info; |
||
1557 | |||
1558 | if (offset >= sec->rawsize) |
||
1559 | return offset - sec->rawsize + sec->size; |
||
1560 | |||
1561 | lo = 0; |
||
1562 | hi = sec_info->count; |
||
1563 | mid = 0; |
||
1564 | while (lo < hi) |
||
1565 | { |
||
1566 | mid = (lo + hi) / 2; |
||
1567 | if (offset < sec_info->entry[mid].offset) |
||
1568 | hi = mid; |
||
1569 | else if (offset |
||
1570 | >= sec_info->entry[mid].offset + sec_info->entry[mid].size) |
||
1571 | lo = mid + 1; |
||
1572 | else |
||
1573 | break; |
||
1574 | } |
||
1575 | |||
1576 | BFD_ASSERT (lo < hi); |
||
1577 | |||
1578 | /* FDE or CIE was removed. */ |
||
1579 | if (sec_info->entry[mid].removed) |
||
1580 | return (bfd_vma) -1; |
||
1581 | |||
1582 | /* If converting personality pointers to DW_EH_PE_pcrel, there will be |
||
1583 | no need for run-time relocation against the personality field. */ |
||
1584 | if (sec_info->entry[mid].cie |
||
1585 | && sec_info->entry[mid].u.cie.make_per_encoding_relative |
||
1586 | && offset == (sec_info->entry[mid].offset + 8 |
||
1587 | + sec_info->entry[mid].u.cie.personality_offset)) |
||
1588 | return (bfd_vma) -2; |
||
1589 | |||
1590 | /* If converting to DW_EH_PE_pcrel, there will be no need for run-time |
||
1591 | relocation against FDE's initial_location field. */ |
||
1592 | if (!sec_info->entry[mid].cie |
||
1593 | && sec_info->entry[mid].make_relative |
||
1594 | && offset == sec_info->entry[mid].offset + 8) |
||
1595 | return (bfd_vma) -2; |
||
1596 | |||
1597 | /* If converting LSDA pointers to DW_EH_PE_pcrel, there will be no need |
||
1598 | for run-time relocation against LSDA field. */ |
||
1599 | if (!sec_info->entry[mid].cie |
||
1600 | && sec_info->entry[mid].u.fde.cie_inf->u.cie.make_lsda_relative |
||
1601 | && offset == (sec_info->entry[mid].offset + 8 |
||
1602 | + sec_info->entry[mid].lsda_offset)) |
||
1603 | return (bfd_vma) -2; |
||
1604 | |||
1605 | /* If converting to DW_EH_PE_pcrel, there will be no need for run-time |
||
1606 | relocation against DW_CFA_set_loc's arguments. */ |
||
1607 | if (sec_info->entry[mid].set_loc |
||
1608 | && sec_info->entry[mid].make_relative |
||
1609 | && (offset >= sec_info->entry[mid].offset + 8 |
||
1610 | + sec_info->entry[mid].set_loc[1])) |
||
1611 | { |
||
1612 | unsigned int cnt; |
||
1613 | |||
1614 | for (cnt = 1; cnt <= sec_info->entry[mid].set_loc[0]; cnt++) |
||
1615 | if (offset == sec_info->entry[mid].offset + 8 |
||
1616 | + sec_info->entry[mid].set_loc[cnt]) |
||
1617 | return (bfd_vma) -2; |
||
1618 | } |
||
1619 | |||
1620 | /* Any new augmentation bytes go before the first relocation. */ |
||
1621 | return (offset + sec_info->entry[mid].new_offset |
||
1622 | - sec_info->entry[mid].offset |
||
1623 | + extra_augmentation_string_bytes (sec_info->entry + mid) |
||
1624 | + extra_augmentation_data_bytes (sec_info->entry + mid)); |
||
1625 | } |
||
1626 | |||
6324 | serge | 1627 | /* Write out .eh_frame_entry section. Add CANTUNWIND terminator if needed. |
1628 | Also check that the contents look sane. */ |
||
1629 | |||
1630 | bfd_boolean |
||
1631 | _bfd_elf_write_section_eh_frame_entry (bfd *abfd, struct bfd_link_info *info, |
||
1632 | asection *sec, bfd_byte *contents) |
||
1633 | { |
||
1634 | const struct elf_backend_data *bed; |
||
1635 | bfd_byte cantunwind[8]; |
||
1636 | bfd_vma addr; |
||
1637 | bfd_vma last_addr; |
||
1638 | bfd_vma offset; |
||
1639 | asection *text_sec = (asection *) elf_section_data (sec)->sec_info; |
||
1640 | |||
1641 | if (!sec->rawsize) |
||
1642 | sec->rawsize = sec->size; |
||
1643 | |||
1644 | BFD_ASSERT (sec->sec_info_type == SEC_INFO_TYPE_EH_FRAME_ENTRY); |
||
1645 | |||
1646 | /* Check to make sure that the text section corresponding to this eh_frame_entry |
||
1647 | section has not been excluded. In particular, mips16 stub entries will be |
||
1648 | excluded outside of the normal process. */ |
||
1649 | if (sec->flags & SEC_EXCLUDE |
||
1650 | || text_sec->flags & SEC_EXCLUDE) |
||
1651 | return TRUE; |
||
1652 | |||
1653 | if (!bfd_set_section_contents (abfd, sec->output_section, contents, |
||
1654 | sec->output_offset, sec->rawsize)) |
||
1655 | return FALSE; |
||
1656 | |||
1657 | last_addr = bfd_get_signed_32 (abfd, contents); |
||
1658 | /* Check that all the entries are in order. */ |
||
1659 | for (offset = 8; offset < sec->rawsize; offset += 8) |
||
1660 | { |
||
1661 | addr = bfd_get_signed_32 (abfd, contents + offset) + offset; |
||
1662 | if (addr <= last_addr) |
||
1663 | { |
||
1664 | (*_bfd_error_handler) (_("%B: %s not in order"), sec->owner, sec->name); |
||
1665 | return FALSE; |
||
1666 | } |
||
1667 | |||
1668 | last_addr = addr; |
||
1669 | } |
||
1670 | |||
1671 | addr = text_sec->output_section->vma + text_sec->output_offset |
||
1672 | + text_sec->size; |
||
1673 | addr &= ~1; |
||
1674 | addr -= (sec->output_section->vma + sec->output_offset + sec->rawsize); |
||
1675 | if (addr & 1) |
||
1676 | { |
||
1677 | (*_bfd_error_handler) (_("%B: %s invalid input section size"), |
||
1678 | sec->owner, sec->name); |
||
1679 | bfd_set_error (bfd_error_bad_value); |
||
1680 | return FALSE; |
||
1681 | } |
||
1682 | if (last_addr >= addr + sec->rawsize) |
||
1683 | { |
||
1684 | (*_bfd_error_handler) (_("%B: %s points past end of text section"), |
||
1685 | sec->owner, sec->name); |
||
1686 | bfd_set_error (bfd_error_bad_value); |
||
1687 | return FALSE; |
||
1688 | } |
||
1689 | |||
1690 | if (sec->size == sec->rawsize) |
||
1691 | return TRUE; |
||
1692 | |||
1693 | bed = get_elf_backend_data (abfd); |
||
1694 | BFD_ASSERT (sec->size == sec->rawsize + 8); |
||
1695 | BFD_ASSERT ((addr & 1) == 0); |
||
1696 | BFD_ASSERT (bed->cant_unwind_opcode); |
||
1697 | |||
1698 | bfd_put_32 (abfd, addr, cantunwind); |
||
1699 | bfd_put_32 (abfd, (*bed->cant_unwind_opcode) (info), cantunwind + 4); |
||
1700 | return bfd_set_section_contents (abfd, sec->output_section, cantunwind, |
||
1701 | sec->output_offset + sec->rawsize, 8); |
||
1702 | } |
||
1703 | |||
5197 | serge | 1704 | /* Write out .eh_frame section. This is called with the relocated |
1705 | contents. */ |
||
1706 | |||
1707 | bfd_boolean |
||
1708 | _bfd_elf_write_section_eh_frame (bfd *abfd, |
||
1709 | struct bfd_link_info *info, |
||
1710 | asection *sec, |
||
1711 | bfd_byte *contents) |
||
1712 | { |
||
1713 | struct eh_frame_sec_info *sec_info; |
||
1714 | struct elf_link_hash_table *htab; |
||
1715 | struct eh_frame_hdr_info *hdr_info; |
||
1716 | unsigned int ptr_size; |
||
1717 | struct eh_cie_fde *ent; |
||
6324 | serge | 1718 | bfd_size_type sec_size; |
5197 | serge | 1719 | |
1720 | if (sec->sec_info_type != SEC_INFO_TYPE_EH_FRAME) |
||
1721 | /* FIXME: octets_per_byte. */ |
||
1722 | return bfd_set_section_contents (abfd, sec->output_section, contents, |
||
1723 | sec->output_offset, sec->size); |
||
1724 | |||
1725 | ptr_size = (get_elf_backend_data (abfd) |
||
1726 | ->elf_backend_eh_frame_address_size (abfd, sec)); |
||
1727 | BFD_ASSERT (ptr_size != 0); |
||
1728 | |||
1729 | sec_info = (struct eh_frame_sec_info *) elf_section_data (sec)->sec_info; |
||
1730 | htab = elf_hash_table (info); |
||
1731 | hdr_info = &htab->eh_info; |
||
1732 | |||
6324 | serge | 1733 | if (hdr_info->u.dwarf.table && hdr_info->u.dwarf.array == NULL) |
1734 | { |
||
1735 | hdr_info->frame_hdr_is_compact = FALSE; |
||
1736 | hdr_info->u.dwarf.array = (struct eh_frame_array_ent *) |
||
1737 | bfd_malloc (hdr_info->u.dwarf.fde_count |
||
1738 | * sizeof (*hdr_info->u.dwarf.array)); |
||
1739 | } |
||
1740 | if (hdr_info->u.dwarf.array == NULL) |
||
5197 | serge | 1741 | hdr_info = NULL; |
1742 | |||
1743 | /* The new offsets can be bigger or smaller than the original offsets. |
||
1744 | We therefore need to make two passes over the section: one backward |
||
1745 | pass to move entries up and one forward pass to move entries down. |
||
1746 | The two passes won't interfere with each other because entries are |
||
1747 | not reordered */ |
||
1748 | for (ent = sec_info->entry + sec_info->count; ent-- != sec_info->entry;) |
||
1749 | if (!ent->removed && ent->new_offset > ent->offset) |
||
1750 | memmove (contents + ent->new_offset, contents + ent->offset, ent->size); |
||
1751 | |||
1752 | for (ent = sec_info->entry; ent < sec_info->entry + sec_info->count; ++ent) |
||
1753 | if (!ent->removed && ent->new_offset < ent->offset) |
||
1754 | memmove (contents + ent->new_offset, contents + ent->offset, ent->size); |
||
1755 | |||
1756 | for (ent = sec_info->entry; ent < sec_info->entry + sec_info->count; ++ent) |
||
1757 | { |
||
1758 | unsigned char *buf, *end; |
||
1759 | unsigned int new_size; |
||
1760 | |||
1761 | if (ent->removed) |
||
1762 | continue; |
||
1763 | |||
1764 | if (ent->size == 4) |
||
1765 | { |
||
1766 | /* Any terminating FDE must be at the end of the section. */ |
||
1767 | BFD_ASSERT (ent == sec_info->entry + sec_info->count - 1); |
||
1768 | continue; |
||
1769 | } |
||
1770 | |||
1771 | buf = contents + ent->new_offset; |
||
1772 | end = buf + ent->size; |
||
1773 | new_size = size_of_output_cie_fde (ent, ptr_size); |
||
1774 | |||
1775 | /* Update the size. It may be shrinked. */ |
||
1776 | bfd_put_32 (abfd, new_size - 4, buf); |
||
1777 | |||
1778 | /* Filling the extra bytes with DW_CFA_nops. */ |
||
1779 | if (new_size != ent->size) |
||
1780 | memset (end, 0, new_size - ent->size); |
||
1781 | |||
1782 | if (ent->cie) |
||
1783 | { |
||
1784 | /* CIE */ |
||
1785 | if (ent->make_relative |
||
1786 | || ent->u.cie.make_lsda_relative |
||
1787 | || ent->u.cie.per_encoding_relative) |
||
1788 | { |
||
1789 | char *aug; |
||
1790 | unsigned int action, extra_string, extra_data; |
||
1791 | unsigned int per_width, per_encoding; |
||
1792 | |||
1793 | /* Need to find 'R' or 'L' augmentation's argument and modify |
||
1794 | DW_EH_PE_* value. */ |
||
1795 | action = ((ent->make_relative ? 1 : 0) |
||
1796 | | (ent->u.cie.make_lsda_relative ? 2 : 0) |
||
1797 | | (ent->u.cie.per_encoding_relative ? 4 : 0)); |
||
1798 | extra_string = extra_augmentation_string_bytes (ent); |
||
1799 | extra_data = extra_augmentation_data_bytes (ent); |
||
1800 | |||
1801 | /* Skip length, id and version. */ |
||
1802 | buf += 9; |
||
1803 | aug = (char *) buf; |
||
1804 | buf += strlen (aug) + 1; |
||
1805 | skip_leb128 (&buf, end); |
||
1806 | skip_leb128 (&buf, end); |
||
1807 | skip_leb128 (&buf, end); |
||
1808 | if (*aug == 'z') |
||
1809 | { |
||
1810 | /* The uleb128 will always be a single byte for the kind |
||
1811 | of augmentation strings that we're prepared to handle. */ |
||
1812 | *buf++ += extra_data; |
||
1813 | aug++; |
||
1814 | } |
||
1815 | |||
1816 | /* Make room for the new augmentation string and data bytes. */ |
||
1817 | memmove (buf + extra_string + extra_data, buf, end - buf); |
||
1818 | memmove (aug + extra_string, aug, buf - (bfd_byte *) aug); |
||
1819 | buf += extra_string; |
||
1820 | end += extra_string + extra_data; |
||
1821 | |||
1822 | if (ent->add_augmentation_size) |
||
1823 | { |
||
1824 | *aug++ = 'z'; |
||
1825 | *buf++ = extra_data - 1; |
||
1826 | } |
||
1827 | if (ent->u.cie.add_fde_encoding) |
||
1828 | { |
||
1829 | BFD_ASSERT (action & 1); |
||
1830 | *aug++ = 'R'; |
||
1831 | *buf++ = make_pc_relative (DW_EH_PE_absptr, ptr_size); |
||
1832 | action &= ~1; |
||
1833 | } |
||
1834 | |||
1835 | while (action) |
||
1836 | switch (*aug++) |
||
1837 | { |
||
1838 | case 'L': |
||
1839 | if (action & 2) |
||
1840 | { |
||
1841 | BFD_ASSERT (*buf == ent->lsda_encoding); |
||
1842 | *buf = make_pc_relative (*buf, ptr_size); |
||
1843 | action &= ~2; |
||
1844 | } |
||
1845 | buf++; |
||
1846 | break; |
||
1847 | case 'P': |
||
1848 | if (ent->u.cie.make_per_encoding_relative) |
||
1849 | *buf = make_pc_relative (*buf, ptr_size); |
||
1850 | per_encoding = *buf++; |
||
1851 | per_width = get_DW_EH_PE_width (per_encoding, ptr_size); |
||
1852 | BFD_ASSERT (per_width != 0); |
||
1853 | BFD_ASSERT (((per_encoding & 0x70) == DW_EH_PE_pcrel) |
||
1854 | == ent->u.cie.per_encoding_relative); |
||
1855 | if ((per_encoding & 0x70) == DW_EH_PE_aligned) |
||
1856 | buf = (contents |
||
1857 | + ((buf - contents + per_width - 1) |
||
1858 | & ~((bfd_size_type) per_width - 1))); |
||
1859 | if (action & 4) |
||
1860 | { |
||
1861 | bfd_vma val; |
||
1862 | |||
1863 | val = read_value (abfd, buf, per_width, |
||
1864 | get_DW_EH_PE_signed (per_encoding)); |
||
1865 | if (ent->u.cie.make_per_encoding_relative) |
||
1866 | val -= (sec->output_section->vma |
||
1867 | + sec->output_offset |
||
1868 | + (buf - contents)); |
||
1869 | else |
||
1870 | { |
||
1871 | val += (bfd_vma) ent->offset - ent->new_offset; |
||
1872 | val -= extra_string + extra_data; |
||
1873 | } |
||
1874 | write_value (abfd, buf, val, per_width); |
||
1875 | action &= ~4; |
||
1876 | } |
||
1877 | buf += per_width; |
||
1878 | break; |
||
1879 | case 'R': |
||
1880 | if (action & 1) |
||
1881 | { |
||
1882 | BFD_ASSERT (*buf == ent->fde_encoding); |
||
1883 | *buf = make_pc_relative (*buf, ptr_size); |
||
1884 | action &= ~1; |
||
1885 | } |
||
1886 | buf++; |
||
1887 | break; |
||
1888 | case 'S': |
||
1889 | break; |
||
1890 | default: |
||
1891 | BFD_FAIL (); |
||
1892 | } |
||
1893 | } |
||
1894 | } |
||
1895 | else |
||
1896 | { |
||
1897 | /* FDE */ |
||
1898 | bfd_vma value, address; |
||
1899 | unsigned int width; |
||
1900 | bfd_byte *start; |
||
1901 | struct eh_cie_fde *cie; |
||
1902 | |||
1903 | /* Skip length. */ |
||
1904 | cie = ent->u.fde.cie_inf; |
||
1905 | buf += 4; |
||
1906 | value = ((ent->new_offset + sec->output_offset + 4) |
||
1907 | - (cie->new_offset + cie->u.cie.u.sec->output_offset)); |
||
1908 | bfd_put_32 (abfd, value, buf); |
||
6324 | serge | 1909 | if (bfd_link_relocatable (info)) |
1910 | continue; |
||
5197 | serge | 1911 | buf += 4; |
1912 | width = get_DW_EH_PE_width (ent->fde_encoding, ptr_size); |
||
1913 | value = read_value (abfd, buf, width, |
||
1914 | get_DW_EH_PE_signed (ent->fde_encoding)); |
||
1915 | address = value; |
||
1916 | if (value) |
||
1917 | { |
||
1918 | switch (ent->fde_encoding & 0x70) |
||
1919 | { |
||
1920 | case DW_EH_PE_textrel: |
||
1921 | BFD_ASSERT (hdr_info == NULL); |
||
1922 | break; |
||
1923 | case DW_EH_PE_datarel: |
||
1924 | { |
||
1925 | switch (abfd->arch_info->arch) |
||
1926 | { |
||
1927 | case bfd_arch_ia64: |
||
1928 | BFD_ASSERT (elf_gp (abfd) != 0); |
||
1929 | address += elf_gp (abfd); |
||
1930 | break; |
||
1931 | default: |
||
1932 | (*info->callbacks->einfo) |
||
1933 | (_("%P: DW_EH_PE_datarel unspecified" |
||
1934 | " for this architecture.\n")); |
||
1935 | /* Fall thru */ |
||
1936 | case bfd_arch_frv: |
||
1937 | case bfd_arch_i386: |
||
1938 | BFD_ASSERT (htab->hgot != NULL |
||
1939 | && ((htab->hgot->root.type |
||
1940 | == bfd_link_hash_defined) |
||
1941 | || (htab->hgot->root.type |
||
1942 | == bfd_link_hash_defweak))); |
||
1943 | address |
||
1944 | += (htab->hgot->root.u.def.value |
||
1945 | + htab->hgot->root.u.def.section->output_offset |
||
1946 | + (htab->hgot->root.u.def.section->output_section |
||
1947 | ->vma)); |
||
1948 | break; |
||
1949 | } |
||
1950 | } |
||
1951 | break; |
||
1952 | case DW_EH_PE_pcrel: |
||
1953 | value += (bfd_vma) ent->offset - ent->new_offset; |
||
1954 | address += (sec->output_section->vma |
||
1955 | + sec->output_offset |
||
1956 | + ent->offset + 8); |
||
1957 | break; |
||
1958 | } |
||
1959 | if (ent->make_relative) |
||
1960 | value -= (sec->output_section->vma |
||
1961 | + sec->output_offset |
||
1962 | + ent->new_offset + 8); |
||
1963 | write_value (abfd, buf, value, width); |
||
1964 | } |
||
1965 | |||
1966 | start = buf; |
||
1967 | |||
1968 | if (hdr_info) |
||
1969 | { |
||
1970 | /* The address calculation may overflow, giving us a |
||
1971 | value greater than 4G on a 32-bit target when |
||
1972 | dwarf_vma is 64-bit. */ |
||
1973 | if (sizeof (address) > 4 && ptr_size == 4) |
||
1974 | address &= 0xffffffff; |
||
6324 | serge | 1975 | hdr_info->u.dwarf.array[hdr_info->array_count].initial_loc |
1976 | = address; |
||
1977 | hdr_info->u.dwarf.array[hdr_info->array_count].range |
||
1978 | = read_value (abfd, buf + width, width, FALSE); |
||
1979 | hdr_info->u.dwarf.array[hdr_info->array_count++].fde |
||
5197 | serge | 1980 | = (sec->output_section->vma |
1981 | + sec->output_offset |
||
1982 | + ent->new_offset); |
||
1983 | } |
||
1984 | |||
1985 | if ((ent->lsda_encoding & 0x70) == DW_EH_PE_pcrel |
||
1986 | || cie->u.cie.make_lsda_relative) |
||
1987 | { |
||
1988 | buf += ent->lsda_offset; |
||
1989 | width = get_DW_EH_PE_width (ent->lsda_encoding, ptr_size); |
||
1990 | value = read_value (abfd, buf, width, |
||
1991 | get_DW_EH_PE_signed (ent->lsda_encoding)); |
||
1992 | if (value) |
||
1993 | { |
||
1994 | if ((ent->lsda_encoding & 0x70) == DW_EH_PE_pcrel) |
||
1995 | value += (bfd_vma) ent->offset - ent->new_offset; |
||
1996 | else if (cie->u.cie.make_lsda_relative) |
||
1997 | value -= (sec->output_section->vma |
||
1998 | + sec->output_offset |
||
1999 | + ent->new_offset + 8 + ent->lsda_offset); |
||
2000 | write_value (abfd, buf, value, width); |
||
2001 | } |
||
2002 | } |
||
2003 | else if (ent->add_augmentation_size) |
||
2004 | { |
||
2005 | /* Skip the PC and length and insert a zero byte for the |
||
2006 | augmentation size. */ |
||
2007 | buf += width * 2; |
||
2008 | memmove (buf + 1, buf, end - buf); |
||
2009 | *buf = 0; |
||
2010 | } |
||
2011 | |||
2012 | if (ent->set_loc) |
||
2013 | { |
||
2014 | /* Adjust DW_CFA_set_loc. */ |
||
2015 | unsigned int cnt; |
||
2016 | bfd_vma new_offset; |
||
2017 | |||
2018 | width = get_DW_EH_PE_width (ent->fde_encoding, ptr_size); |
||
2019 | new_offset = ent->new_offset + 8 |
||
2020 | + extra_augmentation_string_bytes (ent) |
||
2021 | + extra_augmentation_data_bytes (ent); |
||
2022 | |||
2023 | for (cnt = 1; cnt <= ent->set_loc[0]; cnt++) |
||
2024 | { |
||
2025 | buf = start + ent->set_loc[cnt]; |
||
2026 | |||
2027 | value = read_value (abfd, buf, width, |
||
2028 | get_DW_EH_PE_signed (ent->fde_encoding)); |
||
2029 | if (!value) |
||
2030 | continue; |
||
2031 | |||
2032 | if ((ent->fde_encoding & 0x70) == DW_EH_PE_pcrel) |
||
2033 | value += (bfd_vma) ent->offset + 8 - new_offset; |
||
2034 | if (ent->make_relative) |
||
2035 | value -= (sec->output_section->vma |
||
2036 | + sec->output_offset |
||
2037 | + new_offset + ent->set_loc[cnt]); |
||
2038 | write_value (abfd, buf, value, width); |
||
2039 | } |
||
2040 | } |
||
2041 | } |
||
2042 | } |
||
2043 | |||
2044 | /* We don't align the section to its section alignment since the |
||
2045 | runtime library only expects all CIE/FDE records aligned at |
||
2046 | the pointer size. _bfd_elf_discard_section_eh_frame should |
||
2047 | have padded CIE/FDE records to multiple of pointer size with |
||
2048 | size_of_output_cie_fde. */ |
||
6324 | serge | 2049 | sec_size = sec->size; |
2050 | if (sec_info->count != 0 |
||
2051 | && sec_info->entry[sec_info->count - 1].size == 4) |
||
2052 | sec_size -= 4; |
||
2053 | if ((sec_size % ptr_size) != 0) |
||
5197 | serge | 2054 | abort (); |
2055 | |||
2056 | /* FIXME: octets_per_byte. */ |
||
2057 | return bfd_set_section_contents (abfd, sec->output_section, |
||
2058 | contents, (file_ptr) sec->output_offset, |
||
2059 | sec->size); |
||
2060 | } |
||
2061 | |||
2062 | /* Helper function used to sort .eh_frame_hdr search table by increasing |
||
2063 | VMA of FDE initial location. */ |
||
2064 | |||
2065 | static int |
||
2066 | vma_compare (const void *a, const void *b) |
||
2067 | { |
||
2068 | const struct eh_frame_array_ent *p = (const struct eh_frame_array_ent *) a; |
||
2069 | const struct eh_frame_array_ent *q = (const struct eh_frame_array_ent *) b; |
||
2070 | if (p->initial_loc > q->initial_loc) |
||
2071 | return 1; |
||
2072 | if (p->initial_loc < q->initial_loc) |
||
2073 | return -1; |
||
6324 | serge | 2074 | if (p->range > q->range) |
2075 | return 1; |
||
2076 | if (p->range < q->range) |
||
2077 | return -1; |
||
5197 | serge | 2078 | return 0; |
2079 | } |
||
2080 | |||
6324 | serge | 2081 | /* Reorder .eh_frame_entry sections to match the associated text sections. |
2082 | This routine is called during the final linking step, just before writing |
||
2083 | the contents. At this stage, sections in the eh_frame_hdr_info are already |
||
2084 | sorted in order of increasing text section address and so we simply need |
||
2085 | to make the .eh_frame_entrys follow that same order. Note that it is |
||
2086 | invalid for a linker script to try to force a particular order of |
||
2087 | .eh_frame_entry sections. */ |
||
2088 | |||
2089 | bfd_boolean |
||
2090 | _bfd_elf_fixup_eh_frame_hdr (struct bfd_link_info *info) |
||
2091 | { |
||
2092 | asection *sec = NULL; |
||
2093 | asection *osec; |
||
2094 | struct eh_frame_hdr_info *hdr_info; |
||
2095 | unsigned int i; |
||
2096 | bfd_vma offset; |
||
2097 | struct bfd_link_order *p; |
||
2098 | |||
2099 | hdr_info = &elf_hash_table (info)->eh_info; |
||
2100 | |||
2101 | if (hdr_info->hdr_sec == NULL |
||
2102 | || info->eh_frame_hdr_type != COMPACT_EH_HDR |
||
2103 | || hdr_info->array_count == 0) |
||
2104 | return TRUE; |
||
2105 | |||
2106 | /* Change section output offsets to be in text section order. */ |
||
2107 | offset = 8; |
||
2108 | osec = hdr_info->u.compact.entries[0]->output_section; |
||
2109 | for (i = 0; i < hdr_info->array_count; i++) |
||
2110 | { |
||
2111 | sec = hdr_info->u.compact.entries[i]; |
||
2112 | if (sec->output_section != osec) |
||
2113 | { |
||
2114 | (*_bfd_error_handler) |
||
2115 | (_("Invalid output section for .eh_frame_entry: %s"), |
||
2116 | sec->output_section->name); |
||
2117 | return FALSE; |
||
2118 | } |
||
2119 | sec->output_offset = offset; |
||
2120 | offset += sec->size; |
||
2121 | } |
||
2122 | |||
2123 | |||
2124 | /* Fix the link_order to match. */ |
||
2125 | for (p = sec->output_section->map_head.link_order; p != NULL; p = p->next) |
||
2126 | { |
||
2127 | if (p->type != bfd_indirect_link_order) |
||
2128 | abort(); |
||
2129 | |||
2130 | p->offset = p->u.indirect.section->output_offset; |
||
2131 | if (p->next != NULL) |
||
2132 | i--; |
||
2133 | } |
||
2134 | |||
2135 | if (i != 0) |
||
2136 | { |
||
2137 | (*_bfd_error_handler) |
||
2138 | (_("Invalid contents in %s section"), osec->name); |
||
2139 | return FALSE; |
||
2140 | } |
||
2141 | |||
2142 | return TRUE; |
||
2143 | } |
||
2144 | |||
2145 | /* The .eh_frame_hdr format for Compact EH frames: |
||
2146 | ubyte version (2) |
||
2147 | ubyte eh_ref_enc (DW_EH_PE_* encoding of typinfo references) |
||
2148 | uint32_t count (Number of entries in table) |
||
2149 | [array from .eh_frame_entry sections] */ |
||
2150 | |||
2151 | static bfd_boolean |
||
2152 | write_compact_eh_frame_hdr (bfd *abfd, struct bfd_link_info *info) |
||
2153 | { |
||
2154 | struct elf_link_hash_table *htab; |
||
2155 | struct eh_frame_hdr_info *hdr_info; |
||
2156 | asection *sec; |
||
2157 | const struct elf_backend_data *bed; |
||
2158 | bfd_vma count; |
||
2159 | bfd_byte contents[8]; |
||
2160 | unsigned int i; |
||
2161 | |||
2162 | htab = elf_hash_table (info); |
||
2163 | hdr_info = &htab->eh_info; |
||
2164 | sec = hdr_info->hdr_sec; |
||
2165 | |||
2166 | if (sec->size != 8) |
||
2167 | abort(); |
||
2168 | |||
2169 | for (i = 0; i < sizeof (contents); i++) |
||
2170 | contents[i] = 0; |
||
2171 | |||
2172 | contents[0] = COMPACT_EH_HDR; |
||
2173 | bed = get_elf_backend_data (abfd); |
||
2174 | |||
2175 | BFD_ASSERT (bed->compact_eh_encoding); |
||
2176 | contents[1] = (*bed->compact_eh_encoding) (info); |
||
2177 | |||
2178 | count = (sec->output_section->size - 8) / 8; |
||
2179 | bfd_put_32 (abfd, count, contents + 4); |
||
2180 | return bfd_set_section_contents (abfd, sec->output_section, contents, |
||
2181 | (file_ptr) sec->output_offset, sec->size); |
||
2182 | } |
||
2183 | |||
2184 | /* The .eh_frame_hdr format for DWARF frames: |
||
2185 | |||
5197 | serge | 2186 | ubyte version (currently 1) |
2187 | ubyte eh_frame_ptr_enc (DW_EH_PE_* encoding of pointer to start of |
||
2188 | .eh_frame section) |
||
2189 | ubyte fde_count_enc (DW_EH_PE_* encoding of total FDE count |
||
2190 | number (or DW_EH_PE_omit if there is no |
||
2191 | binary search table computed)) |
||
2192 | ubyte table_enc (DW_EH_PE_* encoding of binary search table, |
||
2193 | or DW_EH_PE_omit if not present. |
||
2194 | DW_EH_PE_datarel is using address of |
||
2195 | .eh_frame_hdr section start as base) |
||
2196 | [encoded] eh_frame_ptr (pointer to start of .eh_frame section) |
||
2197 | optionally followed by: |
||
2198 | [encoded] fde_count (total number of FDEs in .eh_frame section) |
||
2199 | fde_count x [encoded] initial_loc, fde |
||
2200 | (array of encoded pairs containing |
||
2201 | FDE initial_location field and FDE address, |
||
2202 | sorted by increasing initial_loc). */ |
||
2203 | |||
6324 | serge | 2204 | static bfd_boolean |
2205 | write_dwarf_eh_frame_hdr (bfd *abfd, struct bfd_link_info *info) |
||
5197 | serge | 2206 | { |
2207 | struct elf_link_hash_table *htab; |
||
2208 | struct eh_frame_hdr_info *hdr_info; |
||
2209 | asection *sec; |
||
2210 | bfd_boolean retval = TRUE; |
||
2211 | |||
2212 | htab = elf_hash_table (info); |
||
2213 | hdr_info = &htab->eh_info; |
||
2214 | sec = hdr_info->hdr_sec; |
||
2215 | bfd_byte *contents; |
||
2216 | asection *eh_frame_sec; |
||
2217 | bfd_size_type size; |
||
2218 | bfd_vma encoded_eh_frame; |
||
2219 | |||
2220 | size = EH_FRAME_HDR_SIZE; |
||
6324 | serge | 2221 | if (hdr_info->u.dwarf.array |
2222 | && hdr_info->array_count == hdr_info->u.dwarf.fde_count) |
||
2223 | size += 4 + hdr_info->u.dwarf.fde_count * 8; |
||
5197 | serge | 2224 | contents = (bfd_byte *) bfd_malloc (size); |
2225 | if (contents == NULL) |
||
2226 | return FALSE; |
||
2227 | |||
2228 | eh_frame_sec = bfd_get_section_by_name (abfd, ".eh_frame"); |
||
2229 | if (eh_frame_sec == NULL) |
||
2230 | { |
||
2231 | free (contents); |
||
2232 | return FALSE; |
||
2233 | } |
||
2234 | |||
2235 | memset (contents, 0, EH_FRAME_HDR_SIZE); |
||
2236 | /* Version. */ |
||
2237 | contents[0] = 1; |
||
2238 | /* .eh_frame offset. */ |
||
2239 | contents[1] = get_elf_backend_data (abfd)->elf_backend_encode_eh_address |
||
2240 | (abfd, info, eh_frame_sec, 0, sec, 4, &encoded_eh_frame); |
||
2241 | |||
6324 | serge | 2242 | if (hdr_info->u.dwarf.array |
2243 | && hdr_info->array_count == hdr_info->u.dwarf.fde_count) |
||
5197 | serge | 2244 | { |
2245 | /* FDE count encoding. */ |
||
2246 | contents[2] = DW_EH_PE_udata4; |
||
2247 | /* Search table encoding. */ |
||
2248 | contents[3] = DW_EH_PE_datarel | DW_EH_PE_sdata4; |
||
2249 | } |
||
2250 | else |
||
2251 | { |
||
2252 | contents[2] = DW_EH_PE_omit; |
||
2253 | contents[3] = DW_EH_PE_omit; |
||
2254 | } |
||
2255 | bfd_put_32 (abfd, encoded_eh_frame, contents + 4); |
||
2256 | |||
2257 | if (contents[2] != DW_EH_PE_omit) |
||
2258 | { |
||
2259 | unsigned int i; |
||
6324 | serge | 2260 | bfd_boolean overlap, overflow; |
5197 | serge | 2261 | |
6324 | serge | 2262 | bfd_put_32 (abfd, hdr_info->u.dwarf.fde_count, |
2263 | contents + EH_FRAME_HDR_SIZE); |
||
2264 | qsort (hdr_info->u.dwarf.array, hdr_info->u.dwarf.fde_count, |
||
2265 | sizeof (*hdr_info->u.dwarf.array), vma_compare); |
||
2266 | overlap = FALSE; |
||
2267 | overflow = FALSE; |
||
2268 | for (i = 0; i < hdr_info->u.dwarf.fde_count; i++) |
||
2269 | { |
||
2270 | bfd_vma val; |
||
2271 | |||
2272 | val = hdr_info->u.dwarf.array[i].initial_loc |
||
2273 | - sec->output_section->vma; |
||
2274 | val = ((val & 0xffffffff) ^ 0x80000000) - 0x80000000; |
||
2275 | if (elf_elfheader (abfd)->e_ident[EI_CLASS] == ELFCLASS64 |
||
2276 | && (hdr_info->u.dwarf.array[i].initial_loc |
||
2277 | != sec->output_section->vma + val)) |
||
2278 | overflow = TRUE; |
||
2279 | bfd_put_32 (abfd, val, contents + EH_FRAME_HDR_SIZE + i * 8 + 4); |
||
2280 | val = hdr_info->u.dwarf.array[i].fde - sec->output_section->vma; |
||
2281 | val = ((val & 0xffffffff) ^ 0x80000000) - 0x80000000; |
||
2282 | if (elf_elfheader (abfd)->e_ident[EI_CLASS] == ELFCLASS64 |
||
2283 | && (hdr_info->u.dwarf.array[i].fde |
||
2284 | != sec->output_section->vma + val)) |
||
2285 | overflow = TRUE; |
||
2286 | bfd_put_32 (abfd, val, contents + EH_FRAME_HDR_SIZE + i * 8 + 8); |
||
2287 | if (i != 0 |
||
2288 | && (hdr_info->u.dwarf.array[i].initial_loc |
||
2289 | < (hdr_info->u.dwarf.array[i - 1].initial_loc |
||
2290 | + hdr_info->u.dwarf.array[i - 1].range))) |
||
2291 | overlap = TRUE; |
||
2292 | } |
||
2293 | if (overflow) |
||
2294 | (*info->callbacks->einfo) (_("%P: .eh_frame_hdr entry overflow.\n")); |
||
2295 | if (overlap) |
||
2296 | (*info->callbacks->einfo) |
||
2297 | (_("%P: .eh_frame_hdr refers to overlapping FDEs.\n")); |
||
2298 | if (overflow || overlap) |
||
2299 | { |
||
2300 | bfd_set_error (bfd_error_bad_value); |
||
2301 | retval = FALSE; |
||
5197 | serge | 2302 | } |
2303 | } |
||
2304 | |||
2305 | /* FIXME: octets_per_byte. */ |
||
6324 | serge | 2306 | if (!bfd_set_section_contents (abfd, sec->output_section, contents, |
5197 | serge | 2307 | (file_ptr) sec->output_offset, |
6324 | serge | 2308 | sec->size)) |
2309 | retval = FALSE; |
||
5197 | serge | 2310 | free (contents); |
6324 | serge | 2311 | |
2312 | if (hdr_info->u.dwarf.array != NULL) |
||
2313 | free (hdr_info->u.dwarf.array); |
||
5197 | serge | 2314 | return retval; |
2315 | } |
||
2316 | |||
6324 | serge | 2317 | /* Write out .eh_frame_hdr section. This must be called after |
2318 | _bfd_elf_write_section_eh_frame has been called on all input |
||
2319 | .eh_frame sections. */ |
||
2320 | |||
2321 | bfd_boolean |
||
2322 | _bfd_elf_write_section_eh_frame_hdr (bfd *abfd, struct bfd_link_info *info) |
||
2323 | { |
||
2324 | struct elf_link_hash_table *htab; |
||
2325 | struct eh_frame_hdr_info *hdr_info; |
||
2326 | asection *sec; |
||
2327 | |||
2328 | htab = elf_hash_table (info); |
||
2329 | hdr_info = &htab->eh_info; |
||
2330 | sec = hdr_info->hdr_sec; |
||
2331 | |||
2332 | if (info->eh_frame_hdr_type == 0 || sec == NULL) |
||
2333 | return TRUE; |
||
2334 | |||
2335 | if (info->eh_frame_hdr_type == COMPACT_EH_HDR) |
||
2336 | return write_compact_eh_frame_hdr (abfd, info); |
||
2337 | else |
||
2338 | return write_dwarf_eh_frame_hdr (abfd, info); |
||
2339 | } |
||
2340 | |||
5197 | serge | 2341 | /* Return the width of FDE addresses. This is the default implementation. */ |
2342 | |||
2343 | unsigned int |
||
2344 | _bfd_elf_eh_frame_address_size (bfd *abfd, asection *sec ATTRIBUTE_UNUSED) |
||
2345 | { |
||
2346 | return elf_elfheader (abfd)->e_ident[EI_CLASS] == ELFCLASS64 ? 8 : 4; |
||
2347 | } |
||
2348 | |||
2349 | /* Decide whether we can use a PC-relative encoding within the given |
||
2350 | EH frame section. This is the default implementation. */ |
||
2351 | |||
2352 | bfd_boolean |
||
2353 | _bfd_elf_can_make_relative (bfd *input_bfd ATTRIBUTE_UNUSED, |
||
2354 | struct bfd_link_info *info ATTRIBUTE_UNUSED, |
||
2355 | asection *eh_frame_section ATTRIBUTE_UNUSED) |
||
2356 | { |
||
2357 | return TRUE; |
||
2358 | } |
||
2359 | |||
2360 | /* Select an encoding for the given address. Preference is given to |
||
2361 | PC-relative addressing modes. */ |
||
2362 | |||
2363 | bfd_byte |
||
2364 | _bfd_elf_encode_eh_address (bfd *abfd ATTRIBUTE_UNUSED, |
||
2365 | struct bfd_link_info *info ATTRIBUTE_UNUSED, |
||
2366 | asection *osec, bfd_vma offset, |
||
2367 | asection *loc_sec, bfd_vma loc_offset, |
||
2368 | bfd_vma *encoded) |
||
2369 | { |
||
2370 | *encoded = osec->vma + offset - |
||
2371 | (loc_sec->output_section->vma + loc_sec->output_offset + loc_offset); |
||
2372 | return DW_EH_PE_pcrel | DW_EH_PE_sdata4; |
||
2373 | }>>>>>>=>>>>=>>=>>>>=>>>>>>>>>>=>>>>>=>>>>>>>>>=>><>><>> |