1 | /******************************************************************************* |
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2 | mach_inject.c |
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3 | Copyright (c) 2003-2005 Jonathan 'Wolf' Rentzsch: <http://rentzsch.com> |
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4 | Some rights reserved: <http://creativecommons.org/licenses/by/2.0/> |
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5 | |
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6 | ***************************************************************************/ |
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7 | |
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8 | #include "mach_inject.h" |
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9 | |
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10 | #include <mach-o/dyld.h> |
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11 | #include <mach-o/getsect.h> |
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12 | #include <mach/mach.h> |
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13 | #include <sys/stat.h> |
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14 | #include <sys/errno.h> |
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15 | #include <assert.h> |
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16 | #include <stdlib.h> // for malloc() |
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17 | #include <stdio.h> // for printf() |
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18 | #include <mach-o/fat.h> // for fat structure decoding |
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19 | #include <mach-o/arch.h> // to know which is local arch |
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20 | #include <fcntl.h> // for open/close |
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21 | // for mmap() |
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22 | #include <sys/types.h> |
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23 | #include <sys/mman.h> |
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24 | |
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25 | #ifndef COMPILE_TIME_ASSERT( exp ) |
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26 | #define COMPILE_TIME_ASSERT( exp ) { switch (0) { case 0: case (exp):; } } |
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27 | #endif |
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28 | #define ASSERT_CAST( CAST_TO, CAST_FROM ) \ |
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29 | COMPILE_TIME_ASSERT( sizeof(CAST_TO)==sizeof(CAST_FROM) ) |
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30 | |
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31 | #if defined(__i386__) |
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32 | void* fixedUpImageFromImage ( |
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33 | const void *image, |
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34 | unsigned long imageSize, |
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35 | unsigned int jumpTableOffset, |
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36 | unsigned int jumpTableSize, |
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37 | ptrdiff_t fixUpOffset); |
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38 | #endif /* __i386__ */ |
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39 | |
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40 | /******************************************************************************* |
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41 | * |
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42 | * Interface |
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43 | * |
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44 | *******************************************************************************/ |
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45 | #pragma mark - |
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46 | #pragma mark (Interface) |
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47 | |
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48 | mach_error_t |
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49 | mach_inject( |
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50 | const mach_inject_entry threadEntry, |
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51 | const void *paramBlock, |
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52 | size_t paramSize, |
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53 | pid_t targetProcess, |
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54 | vm_size_t stackSize ) |
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55 | { |
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56 | assert( threadEntry ); |
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57 | assert( targetProcess > 0 ); |
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58 | assert( stackSize == 0 || stackSize > 1024 ); |
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59 | |
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60 | // Find the image. |
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61 | const void *image; |
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62 | unsigned long imageSize; |
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63 | unsigned int jumpTableOffset; |
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64 | unsigned int jumpTableSize; |
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65 | mach_error_t err = machImageForPointer( threadEntry, &image, &imageSize, &jumpTableOffset, &jumpTableSize ); |
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66 | |
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67 | // Initialize stackSize to default if requested. |
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68 | if( stackSize == 0 ) |
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69 | /** @bug |
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70 | We only want an 8K default, fix the plop-in-the-middle code below. |
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71 | */ |
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72 | stackSize = 16 * 1024; |
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73 | |
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74 | // Convert PID to Mach Task ref. |
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75 | mach_port_t remoteTask = 0; |
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76 | if( !err ) { |
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77 | err = task_for_pid( mach_task_self(), targetProcess, &remoteTask ); |
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78 | #if defined(__i386__) |
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79 | if (err == 5) fprintf(stderr, "Could not access task for pid %d. You probably need to add user to procmod group\n", targetProcess); |
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80 | #endif |
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81 | } |
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82 | |
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83 | /** @todo |
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84 | Would be nice to just allocate one block for both the remote stack |
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85 | *and* the remoteCode (including the parameter data block once that's |
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86 | written. |
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87 | */ |
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88 | |
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89 | // Allocate the remoteStack. |
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90 | vm_address_t remoteStack = (vm_address_t)NULL; |
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91 | if( !err ) |
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92 | err = vm_allocate( remoteTask, &remoteStack, stackSize, 1 ); |
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93 | |
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94 | // Allocate the code. |
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95 | vm_address_t remoteCode = (vm_address_t)NULL; |
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96 | if( !err ) |
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97 | err = vm_allocate( remoteTask, &remoteCode, imageSize, 1 ); |
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98 | if( !err ) { |
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99 | ASSERT_CAST( pointer_t, image ); |
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100 | #if defined (__ppc__) || defined (__ppc64__) |
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101 | err = vm_write( remoteTask, remoteCode, (pointer_t) image, imageSize ); |
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102 | #elif defined (__i386__) |
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103 | // on intel, jump table use relative jump instructions (jmp), which means |
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104 | // the offset needs to be corrected. We thus copy the image and fix the offset by hand. |
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105 | ptrdiff_t fixUpOffset = (ptrdiff_t) (image - remoteCode); |
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106 | void * fixedUpImage = fixedUpImageFromImage(image, imageSize, jumpTableOffset, jumpTableSize, fixUpOffset); |
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107 | err = vm_write( remoteTask, remoteCode, (pointer_t) fixedUpImage, imageSize ); |
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108 | free(fixedUpImage); |
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109 | #endif |
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110 | } |
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111 | |
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112 | // Allocate the paramBlock if specified. |
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113 | vm_address_t remoteParamBlock = (vm_address_t)NULL; |
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114 | if( !err && paramBlock != NULL && paramSize ) { |
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115 | err = vm_allocate( remoteTask, &remoteParamBlock, paramSize, 1 ); |
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116 | if( !err ) { |
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117 | ASSERT_CAST( pointer_t, paramBlock ); |
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118 | err = vm_write( remoteTask, remoteParamBlock, |
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119 | (pointer_t) paramBlock, paramSize ); |
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120 | } |
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121 | } |
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122 | |
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123 | // Calculate offsets. |
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124 | ptrdiff_t threadEntryOffset, imageOffset; |
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125 | if( !err ) { |
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126 | //assert( (void*)threadEntry >= image && (void*)threadEntry <= (image+imageSize) ); |
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127 | ASSERT_CAST( void*, threadEntry ); |
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128 | threadEntryOffset = ((void*) threadEntry) - image; |
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129 | |
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130 | ASSERT_CAST( void*, remoteCode ); |
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131 | imageOffset = ((void*) remoteCode) - image; |
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132 | } |
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133 | |
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134 | // Allocate the thread. |
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135 | thread_act_t remoteThread; |
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136 | #if defined (__ppc__) || defined (__ppc64__) |
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137 | if( !err ) { |
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138 | ppc_thread_state_t remoteThreadState; |
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139 | |
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140 | /** @bug |
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141 | Stack math should be more sophisticated than this (ala redzone). |
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142 | */ |
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143 | remoteStack += stackSize / 2; |
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144 | |
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145 | bzero( &remoteThreadState, sizeof(remoteThreadState) ); |
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146 | |
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147 | ASSERT_CAST( unsigned int, remoteCode ); |
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148 | remoteThreadState.srr0 = (unsigned int) remoteCode; |
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149 | remoteThreadState.srr0 += threadEntryOffset; |
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150 | assert( remoteThreadState.srr0 < (remoteCode + imageSize) ); |
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151 | |
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152 | ASSERT_CAST( unsigned int, remoteStack ); |
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153 | remoteThreadState.r1 = (unsigned int) remoteStack; |
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154 | |
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155 | ASSERT_CAST( unsigned int, imageOffset ); |
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156 | remoteThreadState.r3 = (unsigned int) imageOffset; |
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157 | |
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158 | ASSERT_CAST( unsigned int, remoteParamBlock ); |
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159 | remoteThreadState.r4 = (unsigned int) remoteParamBlock; |
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160 | |
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161 | ASSERT_CAST( unsigned int, paramSize ); |
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162 | remoteThreadState.r5 = (unsigned int) paramSize; |
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163 | |
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164 | ASSERT_CAST( unsigned int, 0xDEADBEEF ); |
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165 | remoteThreadState.lr = (unsigned int) 0xDEADBEEF; |
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166 | |
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167 | #if 0 |
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168 | printf( "remoteCode start: %p\n", (void*) remoteCode ); |
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169 | printf( "remoteCode size: %ld\n", imageSize ); |
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170 | printf( "remoteCode pc: %p\n", (void*) remoteThreadState.srr0 ); |
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171 | printf( "remoteCode end: %p\n", |
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172 | (void*) (((char*)remoteCode)+imageSize) ); |
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173 | fflush(0); |
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174 | #endif |
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175 | |
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176 | err = thread_create_running( remoteTask, PPC_THREAD_STATE, |
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177 | (thread_state_t) &remoteThreadState, PPC_THREAD_STATE_COUNT, |
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178 | &remoteThread ); |
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179 | } |
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180 | #elif defined (__i386__) |
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181 | if( !err ) { |
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182 | |
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183 | i386_thread_state_t remoteThreadState; |
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184 | bzero( &remoteThreadState, sizeof(remoteThreadState) ); |
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185 | |
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186 | vm_address_t dummy_thread_struct = remoteStack; |
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187 | remoteStack += (stackSize / 2); // this is the real stack |
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188 | // (*) increase the stack, since we're simulating a CALL instruction, which normally pushes return address on the stack |
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189 | remoteStack -= 4; |
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190 | |
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191 | #define PARAM_COUNT 4 |
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192 | #define STACK_CONTENTS_SIZE ((1+PARAM_COUNT) * sizeof(unsigned int)) |
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193 | unsigned int stackContents[1 + PARAM_COUNT]; // 1 for the return address and 1 for each param |
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194 | // first entry is return address (see above *) |
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195 | stackContents[0] = 0xDEADBEEF; // invalid return address. |
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196 | // then we push function parameters one by one. |
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197 | stackContents[1] = imageOffset; |
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198 | stackContents[2] = remoteParamBlock; |
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199 | stackContents[3] = paramSize; |
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200 | // We use the remote stack we allocated as the fake thread struct. We should probably use a dedicated memory zone. |
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201 | // We don't fill it with 0, vm_allocate did it for us |
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202 | stackContents[4] = dummy_thread_struct; |
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203 | |
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204 | // push stackContents |
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205 | err = vm_write( remoteTask, remoteStack, |
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206 | (pointer_t) stackContents, STACK_CONTENTS_SIZE); |
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207 | |
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208 | // set remote Program Counter |
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209 | remoteThreadState.eip = (unsigned int) (remoteCode); |
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210 | remoteThreadState.eip += threadEntryOffset; |
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211 | |
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212 | // set remote Stack Pointer |
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213 | ASSERT_CAST( unsigned int, remoteStack ); |
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214 | remoteThreadState.esp = (unsigned int) remoteStack; |
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215 | |
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216 | #if 0 |
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217 | printf( "remoteCode start: %p\n", (void*) remoteCode ); |
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218 | printf( "remoteCode size: %ld\n", imageSize ); |
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219 | printf( "remoteCode pc: %p\n", (void*) remoteThreadState.eip ); |
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220 | printf( "remoteCode end: %p\n", |
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221 | (void*) (((char*)remoteCode)+imageSize) ); |
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222 | fflush(0); |
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223 | #endif |
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224 | // create thread and launch it |
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225 | err = thread_create_running( remoteTask, i386_THREAD_STATE, |
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226 | (thread_state_t) &remoteThreadState, i386_THREAD_STATE_COUNT, |
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227 | &remoteThread ); |
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228 | } |
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229 | #else |
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230 | #error architecture not supported |
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231 | #endif |
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232 | |
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233 | if( err ) { |
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234 | if( remoteParamBlock ) |
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235 | vm_deallocate( remoteTask, remoteParamBlock, paramSize ); |
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236 | if( remoteCode ) |
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237 | vm_deallocate( remoteTask, remoteCode, imageSize ); |
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238 | if( remoteStack ) |
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239 | vm_deallocate( remoteTask, remoteStack, stackSize ); |
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240 | } |
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241 | |
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242 | return err; |
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243 | } |
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244 | |
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245 | mach_error_t |
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246 | machImageForPointer( |
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247 | const void *pointer, |
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248 | const void **image, |
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249 | unsigned long *size, |
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250 | unsigned int *jumpTableOffset, |
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251 | unsigned int *jumpTableSize ) |
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252 | { |
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253 | assert( pointer ); |
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254 | assert( image ); |
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255 | assert( size ); |
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256 | |
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257 | unsigned long p = (unsigned long) pointer; |
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258 | |
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259 | if (jumpTableOffset && jumpTableSize) { |
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260 | *jumpTableOffset = 0; |
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261 | *jumpTableSize = 0; |
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262 | } |
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263 | |
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264 | unsigned long imageIndex, imageCount = _dyld_image_count(); |
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265 | for( imageIndex = 0; imageIndex < imageCount; imageIndex++ ) { |
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266 | const struct mach_header *header = _dyld_get_image_header( imageIndex ); |
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267 | const struct section *section = getsectbynamefromheader( header, |
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268 | SEG_TEXT, |
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269 | SECT_TEXT ); |
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270 | long start = section->addr + _dyld_get_image_vmaddr_slide( imageIndex ); |
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271 | long stop = start + section->size; |
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272 | if( p >= start && p <= stop ) { |
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273 | // It is truely insane we have to stat() the file system in order |
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274 | // to discover the size of an in-memory data structure. |
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275 | const char *imageName = _dyld_get_image_name( imageIndex ); |
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276 | assert( imageName ); |
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277 | struct stat sb; |
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278 | if( stat( imageName, &sb ) ) |
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279 | return unix_err( errno ); |
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280 | if( image ) { |
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281 | ASSERT_CAST( void*, header ); |
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282 | *image = (void*) header; |
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283 | } |
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284 | if( size ) { |
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285 | ;//assertUInt32( st_size ); |
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286 | *size = sb.st_size; |
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287 | |
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288 | // needed for Universal binaries. Check if file is fat and get image size from there. |
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289 | int fd = open (imageName, O_RDONLY); |
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290 | size_t mapSize = *size; |
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291 | char * fileImage = mmap (NULL, mapSize, PROT_READ, MAP_FILE, fd, 0); |
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292 | |
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293 | struct fat_header* fatHeader = (struct fat_header *)fileImage; |
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294 | if (fatHeader->magic == OSSwapBigToHostInt32(FAT_MAGIC)) { |
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295 | //printf("This is a fat binary\n"); |
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296 | uint32_t archCount = OSSwapBigToHostInt32(fatHeader->nfat_arch); |
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297 | |
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298 | NXArchInfo const *localArchInfo = NXGetLocalArchInfo(); |
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299 | |
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300 | struct fat_arch* arch = (struct fat_arch *)(fileImage + sizeof(struct fat_header)); |
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301 | struct fat_arch* matchingArch = NULL; |
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302 | |
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303 | int archIndex = 0; |
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304 | for (archIndex = 0; archIndex < archCount; archIndex++) { |
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305 | cpu_type_t cpuType = OSSwapBigToHostInt32(arch[archIndex].cputype); |
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306 | cpu_subtype_t cpuSubtype = OSSwapBigToHostInt32(arch[archIndex].cpusubtype); |
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307 | |
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308 | if (localArchInfo->cputype == cpuType) { |
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309 | matchingArch = arch + archIndex; |
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310 | if (localArchInfo->cpusubtype == cpuSubtype) break; |
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311 | } |
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312 | } |
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313 | |
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314 | if (matchingArch) { |
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315 | *size = OSSwapBigToHostInt32(matchingArch->size); |
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316 | //printf ("found arch-specific size : %p\n", *size); |
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317 | } |
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318 | } |
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319 | |
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320 | munmap (fileImage, mapSize); |
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321 | close (fd); |
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322 | } |
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323 | if (jumpTableOffset && jumpTableSize) { |
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324 | const struct section * jumpTableSection = getsectbynamefromheader( header, |
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325 | "__IMPORT", |
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326 | "__jump_table" ); |
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327 | if (jumpTableSection) { |
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328 | *jumpTableOffset = jumpTableSection->offset; |
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329 | *jumpTableSize = jumpTableSection->size; |
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330 | } |
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331 | } |
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332 | return err_none; |
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333 | } |
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334 | } |
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335 | |
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336 | return err_threadEntry_image_not_found; |
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337 | } |
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338 | |
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339 | #if defined(__i386__) |
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340 | void* fixedUpImageFromImage ( |
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341 | const void *image, |
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342 | unsigned long imageSize, |
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343 | unsigned int jumpTableOffset, |
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344 | unsigned int jumpTableSize, |
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345 | ptrdiff_t fixUpOffset) |
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346 | { |
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347 | // first copy the full image |
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348 | void *fixedUpImage = (void *) malloc ((size_t)imageSize); |
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349 | bcopy(image, fixedUpImage, imageSize); |
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350 | |
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351 | // address of jump table in copied image |
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352 | void *jumpTable = fixedUpImage + jumpTableOffset; |
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353 | // each JMP instruction is 5 bytes (E9 xx xx xx xx) where E9 is the opcode for JMP |
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354 | int jumpTableCount = jumpTableSize / 5; |
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355 | |
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356 | // skip first "E9" |
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357 | jumpTable++; |
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358 | |
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359 | int entry=0; |
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360 | for (entry = 0; entry < jumpTableCount; entry++) { |
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361 | unsigned int jmpValue = *((unsigned int *)jumpTable); |
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362 | jmpValue += fixUpOffset; |
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363 | *((unsigned int *)jumpTable) = jmpValue; |
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364 | jumpTable+=5; |
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365 | } |
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366 | |
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367 | return fixedUpImage; |
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368 | } |
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369 | #endif /* __i386__ */ |
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