1 //===-- sanitizer_symbolizer_mac.cpp --------------------------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // 9 // This file is shared between various sanitizers' runtime libraries. 10 // 11 // Implementation of Mac-specific "atos" symbolizer. 12 //===----------------------------------------------------------------------===// 13 14 #include "sanitizer_platform.h" 15 #if SANITIZER_APPLE 16 17 #include "sanitizer_allocator_internal.h" 18 #include "sanitizer_mac.h" 19 #include "sanitizer_symbolizer_mac.h" 20 21 #include <dlfcn.h> 22 #include <errno.h> 23 #include <stdlib.h> 24 #include <sys/wait.h> 25 #include <unistd.h> 26 #include <util.h> 27 28 namespace __sanitizer { 29 30 bool DlAddrSymbolizer::SymbolizePC(uptr addr, SymbolizedStack *stack) { 31 Dl_info info; 32 int result = dladdr((const void *)addr, &info); 33 if (!result) return false; 34 35 // Compute offset if possible. `dladdr()` doesn't always ensure that `addr >= 36 // sym_addr` so only compute the offset when this holds. Failure to find the 37 // function offset is not treated as a failure because it might still be 38 // possible to get the symbol name. 39 uptr sym_addr = reinterpret_cast<uptr>(info.dli_saddr); 40 if (addr >= sym_addr) { 41 stack->info.function_offset = addr - sym_addr; 42 } 43 44 const char *demangled = DemangleSwiftAndCXX(info.dli_sname); 45 if (!demangled) return false; 46 stack->info.function = internal_strdup(demangled); 47 return true; 48 } 49 50 bool DlAddrSymbolizer::SymbolizeData(uptr addr, DataInfo *datainfo) { 51 Dl_info info; 52 int result = dladdr((const void *)addr, &info); 53 if (!result) return false; 54 const char *demangled = DemangleSwiftAndCXX(info.dli_sname); 55 datainfo->name = internal_strdup(demangled); 56 datainfo->start = (uptr)info.dli_saddr; 57 return true; 58 } 59 60 class AtosSymbolizerProcess final : public SymbolizerProcess { 61 public: 62 explicit AtosSymbolizerProcess(const char *path) 63 : SymbolizerProcess(path, /*use_posix_spawn*/ true) { 64 pid_str_[0] = '\0'; 65 } 66 67 private: 68 bool StartSymbolizerSubprocess() override { 69 // Put the string command line argument in the object so that it outlives 70 // the call to GetArgV. 71 internal_snprintf(pid_str_, sizeof(pid_str_), "%d", (int)internal_getpid()); 72 73 // Configure sandbox before starting atos process. 74 return SymbolizerProcess::StartSymbolizerSubprocess(); 75 } 76 77 bool ReachedEndOfOutput(const char *buffer, uptr length) const override { 78 return (length >= 1 && buffer[length - 1] == '\n'); 79 } 80 81 void GetArgV(const char *path_to_binary, 82 const char *(&argv)[kArgVMax]) const override { 83 int i = 0; 84 argv[i++] = path_to_binary; 85 argv[i++] = "-p"; 86 argv[i++] = &pid_str_[0]; 87 if (GetMacosAlignedVersion() == MacosVersion(10, 9)) { 88 // On Mavericks atos prints a deprecation warning which we suppress by 89 // passing -d. The warning isn't present on other OSX versions, even the 90 // newer ones. 91 argv[i++] = "-d"; 92 } 93 argv[i++] = nullptr; 94 CHECK_LE(i, kArgVMax); 95 } 96 97 char pid_str_[16]; 98 }; 99 100 #undef K_ATOS_ENV_VAR 101 102 static bool ParseCommandOutput(const char *str, uptr addr, char **out_name, 103 char **out_module, char **out_file, uptr *line, 104 uptr *start_address) { 105 // Trim ending newlines. 106 char *trim; 107 ExtractTokenUpToDelimiter(str, "\n", &trim); 108 109 // The line from `atos` is in one of these formats: 110 // myfunction (in library.dylib) (sourcefile.c:17) 111 // myfunction (in library.dylib) + 0x1fe 112 // myfunction (in library.dylib) + 15 113 // 0xdeadbeef (in library.dylib) + 0x1fe 114 // 0xdeadbeef (in library.dylib) + 15 115 // 0xdeadbeef (in library.dylib) 116 // 0xdeadbeef 117 118 const char *rest = trim; 119 char *symbol_name; 120 rest = ExtractTokenUpToDelimiter(rest, " (in ", &symbol_name); 121 if (rest[0] == '\0') { 122 InternalFree(symbol_name); 123 InternalFree(trim); 124 return false; 125 } 126 127 if (internal_strncmp(symbol_name, "0x", 2) != 0) 128 *out_name = symbol_name; 129 else 130 InternalFree(symbol_name); 131 rest = ExtractTokenUpToDelimiter(rest, ") ", out_module); 132 133 if (rest[0] == '(') { 134 if (out_file) { 135 rest++; 136 rest = ExtractTokenUpToDelimiter(rest, ":", out_file); 137 char *extracted_line_number; 138 rest = ExtractTokenUpToDelimiter(rest, ")", &extracted_line_number); 139 if (line) *line = (uptr)internal_atoll(extracted_line_number); 140 InternalFree(extracted_line_number); 141 } 142 } else if (rest[0] == '+') { 143 rest += 2; 144 uptr offset = internal_atoll(rest); 145 if (start_address) *start_address = addr - offset; 146 } 147 148 InternalFree(trim); 149 return true; 150 } 151 152 AtosSymbolizer::AtosSymbolizer(const char *path, LowLevelAllocator *allocator) 153 : process_(new (*allocator) AtosSymbolizerProcess(path)) {} 154 155 bool AtosSymbolizer::SymbolizePC(uptr addr, SymbolizedStack *stack) { 156 if (!process_) return false; 157 if (addr == 0) return false; 158 char command[32]; 159 internal_snprintf(command, sizeof(command), "0x%zx\n", addr); 160 const char *buf = process_->SendCommand(command); 161 if (!buf) return false; 162 uptr line; 163 uptr start_address = AddressInfo::kUnknown; 164 if (!ParseCommandOutput(buf, addr, &stack->info.function, &stack->info.module, 165 &stack->info.file, &line, &start_address)) { 166 process_ = nullptr; 167 return false; 168 } 169 stack->info.line = (int)line; 170 171 if (start_address == AddressInfo::kUnknown) { 172 // Fallback to dladdr() to get function start address if atos doesn't report 173 // it. 174 Dl_info info; 175 int result = dladdr((const void *)addr, &info); 176 if (result) 177 start_address = reinterpret_cast<uptr>(info.dli_saddr); 178 } 179 180 // Only assign to `function_offset` if we were able to get the function's 181 // start address and we got a sensible `start_address` (dladdr doesn't always 182 // ensure that `addr >= sym_addr`). 183 if (start_address != AddressInfo::kUnknown && addr >= start_address) { 184 stack->info.function_offset = addr - start_address; 185 } 186 return true; 187 } 188 189 bool AtosSymbolizer::SymbolizeData(uptr addr, DataInfo *info) { 190 if (!process_) return false; 191 char command[32]; 192 internal_snprintf(command, sizeof(command), "0x%zx\n", addr); 193 const char *buf = process_->SendCommand(command); 194 if (!buf) return false; 195 if (!ParseCommandOutput(buf, addr, &info->name, &info->module, nullptr, 196 nullptr, &info->start)) { 197 process_ = nullptr; 198 return false; 199 } 200 return true; 201 } 202 203 } // namespace __sanitizer 204 205 #endif // SANITIZER_APPLE 206