1 | #ifndef OBJECT_HPP |
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2 | #define OBJECT_HPP |
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3 | |
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4 | #include "common.hpp" |
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5 | |
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6 | #include <string> |
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7 | #include <vector> |
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8 | #include <mutex> |
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9 | #include <unordered_map> |
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10 | |
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11 | #if IS_LINUX || IS_APPLE |
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12 | #include <unistd.h> |
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13 | #include <dlfcn.h> |
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14 | #if IS_APPLE |
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15 | #include "mach-o.hpp" |
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16 | #else |
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17 | #include "elf.hpp" |
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18 | #endif |
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19 | #elif IS_WINDOWS |
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20 | #include <windows.h> |
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21 | #include "pe.hpp" |
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22 | #endif |
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23 | |
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24 | struct dlframe { |
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25 | std::string obj_path; |
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26 | std::string symbol; |
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27 | uintptr_t raw_address = 0; |
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28 | uintptr_t obj_address = 0; |
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29 | }; |
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30 | |
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31 | #if IS_LINUX || IS_APPLE |
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32 | #if !IS_APPLE |
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33 | static uintptr_t get_module_image_base(const std::string& obj_path) { |
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34 | static std::mutex mutex; |
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35 | std::lock_guard<std::mutex> lock(mutex); |
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36 | static std::unordered_map<std::string, uintptr_t> cache; |
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37 | auto it = cache.find(obj_path); |
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38 | if(it == cache.end()) { |
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39 | // arguably it'd be better to release the lock while computing this, but also arguably it's good to not |
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40 | // have two threads try to do the same computation |
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41 | auto base = elf_get_module_image_base(obj_path); |
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42 | cache.insert(it, {obj_path, base}); |
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43 | return base; |
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44 | } else { |
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45 | return it->second; |
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46 | } |
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47 | } |
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48 | #else |
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49 | static uintptr_t get_module_image_base(const std::string& obj_path) { |
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50 | // We have to parse the Mach-O to find the offset of the text section..... |
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51 | // I don't know how addresses are handled if there is more than one __TEXT load command. I'm assuming for |
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52 | // now that there is only one, and I'm using only the first section entry within that load command. |
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53 | static std::mutex mutex; |
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54 | std::lock_guard<std::mutex> lock(mutex); |
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55 | static std::unordered_map<std::string, uintptr_t> cache; |
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56 | auto it = cache.find(obj_path); |
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57 | if(it == cache.end()) { |
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58 | // arguably it'd be better to release the lock while computing this, but also arguably it's good to not |
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59 | // have two threads try to do the same computation |
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60 | auto base = macho_get_text_vmaddr(obj_path.c_str()); |
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61 | cache.insert(it, {obj_path, base}); |
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62 | return base; |
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63 | } else { |
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64 | return it->second; |
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65 | } |
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66 | } |
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67 | #endif |
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68 | // aladdr queries are needed to get pre-ASLR addresses and targets to run addr2line on |
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69 | static std::vector<dlframe> get_frames_object_info(const std::vector<void*>& addrs) { |
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70 | // reference: https://github.com/bminor/glibc/blob/master/debug/backtracesyms.c |
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71 | std::vector<dlframe> frames; |
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72 | frames.reserve(addrs.size()); |
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73 | for(const void* addr : addrs) { |
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74 | Dl_info info; |
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75 | dlframe frame; |
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76 | frame.raw_address = reinterpret_cast<uintptr_t>(addr); |
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77 | if(dladdr(addr, &info)) { // thread safe |
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78 | // dli_sname and dli_saddr are only present with -rdynamic, sname will be included |
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79 | // but we don't really need dli_saddr |
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80 | frame.obj_path = info.dli_fname; |
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81 | frame.obj_address = reinterpret_cast<uintptr_t>(addr) |
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82 | - reinterpret_cast<uintptr_t>(info.dli_fbase) |
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83 | + get_module_image_base(info.dli_fname); |
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84 | frame.symbol = info.dli_sname ?: ""; |
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85 | } |
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86 | frames.push_back(frame); |
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87 | } |
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88 | return frames; |
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89 | } |
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90 | #else |
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91 | static std::string get_module_name(HMODULE handle) { |
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92 | static std::mutex mutex; |
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93 | std::lock_guard<std::mutex> lock(mutex); |
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94 | static std::unordered_map<HMODULE, std::string> cache; |
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95 | auto it = cache.find(handle); |
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96 | if(it == cache.end()) { |
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97 | char path[MAX_PATH]; |
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98 | if(GetModuleFileNameA(handle, path, sizeof(path))) { |
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99 | ///fprintf(stderr, "path: %s base: %p\n", path, handle); |
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100 | cache.insert(it, {handle, path}); |
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101 | return path; |
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102 | } else { |
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103 | fprintf(stderr, "%s\n", std::system_error(GetLastError(), std::system_category()).what()); |
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104 | cache.insert(it, {handle, ""}); |
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105 | return ""; |
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106 | } |
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107 | } else { |
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108 | return it->second; |
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109 | } |
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110 | } |
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111 | static uintptr_t get_module_image_base(const std::string& obj_path) { |
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112 | static std::mutex mutex; |
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113 | std::lock_guard<std::mutex> lock(mutex); |
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114 | static std::unordered_map<std::string, uintptr_t> cache; |
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115 | auto it = cache.find(obj_path); |
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116 | if(it == cache.end()) { |
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117 | // arguably it'd be better to release the lock while computing this, but also arguably it's good to not |
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118 | // have two threads try to do the same computation |
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119 | auto base = pe_get_module_image_base(obj_path); |
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120 | cache.insert(it, {obj_path, base}); |
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121 | return base; |
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122 | } else { |
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123 | return it->second; |
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124 | } |
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125 | } |
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126 | // aladdr queries are needed to get pre-ASLR addresses and targets to run addr2line on |
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127 | static std::vector<dlframe> get_frames_object_info(const std::vector<void*>& addrs) { |
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128 | // reference: https://github.com/bminor/glibc/blob/master/debug/backtracesyms.c |
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129 | std::vector<dlframe> frames; |
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130 | frames.reserve(addrs.size()); |
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131 | for(const void* addr : addrs) { |
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132 | dlframe frame; |
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133 | frame.raw_address = reinterpret_cast<uintptr_t>(addr); |
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134 | HMODULE handle; |
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135 | // Multithread safe as long as another thread doesn't come along and free the module |
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136 | if(GetModuleHandleExA( |
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137 | GET_MODULE_HANDLE_EX_FLAG_UNCHANGED_REFCOUNT | GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS, |
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138 | static_cast<const char*>(addr), |
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139 | &handle |
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140 | )) { |
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141 | frame.obj_path = get_module_name(handle); |
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142 | frame.obj_address = reinterpret_cast<uintptr_t>(addr) |
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143 | - reinterpret_cast<uintptr_t>(handle) |
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144 | + get_module_image_base(frame.obj_path); |
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145 | } else { |
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146 | fprintf(stderr, "%s\n", std::system_error(GetLastError(), std::system_category()).what()); |
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147 | } |
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148 | frames.push_back(frame); |
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149 | } |
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150 | return frames; |
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151 | } |
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152 | #endif |
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153 | |
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154 | #endif |
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