libsanitizer/sanitizer_common/sanitizer_symbolizer_libcdep.cc

   1 //===-- sanitizer_symbolizer_libcdep.cc -----------------------------------===//
   2 //
   3 // This file is distributed under the University of Illinois Open Source
   4 // License. See LICENSE.TXT for details.
   5 //
   6 //===----------------------------------------------------------------------===//
   7 //
   8 // This file is shared between AddressSanitizer and ThreadSanitizer
   9 // run-time libraries.
  10 //===----------------------------------------------------------------------===//
  11
  12 #include "sanitizer_allocator_internal.h"
  13 #include "sanitizer_internal_defs.h"
  14 #include "sanitizer_symbolizer_internal.h"
  15
  16 namespace __sanitizer {
  17
  18 Symbolizer *Symbolizer::GetOrInit() {
  19   SpinMutexLock l(&init_mu_);
  20   if (symbolizer_)
  21     return symbolizer_;
  22   symbolizer_ = PlatformInit();
  23   CHECK(symbolizer_);
  24   return symbolizer_;
  25 }
  26
  27 // See sanitizer_symbolizer_markup.cc.
  28 #if !SANITIZER_SYMBOLIZER_MARKUP
  29
  30 const char *ExtractToken(const char *str, const char *delims, char **result) {
  31   uptr prefix_len = internal_strcspn(str, delims);
  32   *result = (char*)InternalAlloc(prefix_len + 1);
  33   internal_memcpy(*result, str, prefix_len);
  34   (*result)[prefix_len] = '\0';
  35   const char *prefix_end = str + prefix_len;
  36   if (*prefix_end != '\0') prefix_end++;
  37   return prefix_end;
  38 }
  39
  40 const char *ExtractInt(const char *str, const char *delims, int *result) {
  41   char *buff;
  42   const char *ret = ExtractToken(str, delims, &buff);
  43   if (buff != 0) {
  44     *result = (int)internal_atoll(buff);
  45   }
  46   InternalFree(buff);
  47   return ret;
  48 }
  49
  50 const char *ExtractUptr(const char *str, const char *delims, uptr *result) {
  51   char *buff;
  52   const char *ret = ExtractToken(str, delims, &buff);
  53   if (buff != 0) {
  54     *result = (uptr)internal_atoll(buff);
  55   }
  56   InternalFree(buff);
  57   return ret;
  58 }
  59
  60 const char *ExtractTokenUpToDelimiter(const char *str, const char *delimiter,
  61                                       char **result) {
  62   const char *found_delimiter = internal_strstr(str, delimiter);
  63   uptr prefix_len =
  64       found_delimiter ? found_delimiter - str : internal_strlen(str);
  65   *result = (char *)InternalAlloc(prefix_len + 1);
  66   internal_memcpy(*result, str, prefix_len);
  67   (*result)[prefix_len] = '\0';
  68   const char *prefix_end = str + prefix_len;
  69   if (*prefix_end != '\0') prefix_end += internal_strlen(delimiter);
  70   return prefix_end;
  71 }
  72
  73 SymbolizedStack *Symbolizer::SymbolizePC(uptr addr) {
  74   BlockingMutexLock l(&mu_);
  75   const char *module_name;
  76   uptr module_offset;
  77   ModuleArch arch;
  78   SymbolizedStack *res = SymbolizedStack::New(addr);
  79   if (!FindModuleNameAndOffsetForAddress(addr, &module_name, &module_offset,
  80                                          &arch))
  81     return res;
  82   // Always fill data about module name and offset.
  83   res->info.FillModuleInfo(module_name, module_offset, arch);
  84   for (auto &tool : tools_) {
  85     SymbolizerScope sym_scope(this);
  86     if (tool.SymbolizePC(addr, res)) {
  87       return res;
  88     }
  89   }
  90   return res;
  91 }
  92
  93 bool Symbolizer::SymbolizeData(uptr addr, DataInfo *info) {
  94   BlockingMutexLock l(&mu_);
  95   const char *module_name;
  96   uptr module_offset;
  97   ModuleArch arch;
  98   if (!FindModuleNameAndOffsetForAddress(addr, &module_name, &module_offset,
  99                                          &arch))
 100     return false;
 101   info->Clear();
 102   info->module = internal_strdup(module_name);
 103   info->module_offset = module_offset;
 104   info->module_arch = arch;
 105   for (auto &tool : tools_) {
 106     SymbolizerScope sym_scope(this);
 107     if (tool.SymbolizeData(addr, info)) {
 108       return true;
 109     }
 110   }
 111   return true;
 112 }
 113
 114 bool Symbolizer::GetModuleNameAndOffsetForPC(uptr pc, const char **module_name,
 115                                              uptr *module_address) {
 116   BlockingMutexLock l(&mu_);
 117   const char *internal_module_name = nullptr;
 118   ModuleArch arch;
 119   if (!FindModuleNameAndOffsetForAddress(pc, &internal_module_name,
 120                                          module_address, &arch))
 121     return false;
 122
 123   if (module_name)
 124     *module_name = module_names_.GetOwnedCopy(internal_module_name);
 125   return true;
 126 }
 127
 128 void Symbolizer::Flush() {
 129   BlockingMutexLock l(&mu_);
 130   for (auto &tool : tools_) {
 131     SymbolizerScope sym_scope(this);
 132     tool.Flush();
 133   }
 134 }
 135
 136 const char *Symbolizer::Demangle(const char *name) {
 137   BlockingMutexLock l(&mu_);
 138   for (auto &tool : tools_) {
 139     SymbolizerScope sym_scope(this);
 140     if (const char *demangled = tool.Demangle(name))
 141       return demangled;
 142   }
 143   return PlatformDemangle(name);
 144 }
 145
 146 bool Symbolizer::FindModuleNameAndOffsetForAddress(uptr address,
 147                                                    const char **module_name,
 148                                                    uptr *module_offset,
 149                                                    ModuleArch *module_arch) {
 150   const LoadedModule *module = FindModuleForAddress(address);
 151   if (module == nullptr)
 152     return false;
 153   *module_name = module->full_name();
 154   *module_offset = address - module->base_address();
 155   *module_arch = module->arch();
 156   return true;
 157 }
 158
 159 void Symbolizer::RefreshModules() {
 160   modules_.init();
 161   fallback_modules_.fallbackInit();
 162   RAW_CHECK(modules_.size() > 0);
 163   modules_fresh_ = true;
 164 }
 165
 166 static const LoadedModule *SearchForModule(const ListOfModules &modules,
 167                                            uptr address) {
 168   for (uptr i = 0; i < modules.size(); i++) {
 169     if (modules[i].containsAddress(address)) {
 170       return &modules[i];
 171     }
 172   }
 173   return nullptr;
 174 }
 175
 176 const LoadedModule *Symbolizer::FindModuleForAddress(uptr address) {
 177   bool modules_were_reloaded = false;
 178   if (!modules_fresh_) {
 179     RefreshModules();
 180     modules_were_reloaded = true;
 181   }
 182   const LoadedModule *module = SearchForModule(modules_, address);
 183   if (module) return module;
 184
 185   // dlopen/dlclose interceptors invalidate the module list, but when
 186   // interception is disabled, we need to retry if the lookup fails in
 187   // case the module list changed.
 188 #if !SANITIZER_INTERCEPT_DLOPEN_DLCLOSE
 189   if (!modules_were_reloaded) {
 190     RefreshModules();
 191     module = SearchForModule(modules_, address);
 192     if (module) return module;
 193   }
 194 #endif
 195
 196   if (fallback_modules_.size()) {
 197     module = SearchForModule(fallback_modules_, address);
 198   }
 199   return module;
 200 }
 201
 202 // For now we assume the following protocol:
 203 // For each request of the form
 204 //   <module_name> <module_offset>
 205 // passed to STDIN, external symbolizer prints to STDOUT response:
 206 //   <function_name>
 207 //   <file_name>:<line_number>:<column_number>
 208 //   <function_name>
 209 //   <file_name>:<line_number>:<column_number>
 210 //   ...
 211 //   <empty line>
 212 class LLVMSymbolizerProcess : public SymbolizerProcess {
 213  public:
 214   explicit LLVMSymbolizerProcess(const char *path) : SymbolizerProcess(path) {}
 215
 216  private:
 217   bool ReachedEndOfOutput(const char *buffer, uptr length) const override {
 218     // Empty line marks the end of llvm-symbolizer output.
 219     return length >= 2 && buffer[length - 1] == '\n' &&
 220            buffer[length - 2] == '\n';
 221   }
 222
 223   // When adding a new architecture, don't forget to also update
 224   // script/asan_symbolize.py and sanitizer_common.h.
 225   void GetArgV(const char *path_to_binary,
 226                const char *(&argv)[kArgVMax]) const override {
 227 #if defined(__x86_64h__)
 228     const char* const kSymbolizerArch = "--default-arch=x86_64h";
 229 #elif defined(__x86_64__)
 230     const char* const kSymbolizerArch = "--default-arch=x86_64";
 231 #elif defined(__i386__)
 232     const char* const kSymbolizerArch = "--default-arch=i386";
 233 #elif defined(__aarch64__)
 234     const char* const kSymbolizerArch = "--default-arch=arm64";
 235 #elif defined(__arm__)
 236     const char* const kSymbolizerArch = "--default-arch=arm";
 237 #elif defined(__powerpc64__) && __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
 238     const char* const kSymbolizerArch = "--default-arch=powerpc64";
 239 #elif defined(__powerpc64__) && __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
 240     const char* const kSymbolizerArch = "--default-arch=powerpc64le";
 241 #elif defined(__s390x__)
 242     const char* const kSymbolizerArch = "--default-arch=s390x";
 243 #elif defined(__s390__)
 244     const char* const kSymbolizerArch = "--default-arch=s390";
 245 #else
 246     const char* const kSymbolizerArch = "--default-arch=unknown";
 247 #endif
 248
 249     const char *const inline_flag = common_flags()->symbolize_inline_frames
 250                                         ? "--inlining=true"
 251                                         : "--inlining=false";
 252     int i = 0;
 253     argv[i++] = path_to_binary;
 254     argv[i++] = inline_flag;
 255     argv[i++] = kSymbolizerArch;
 256     argv[i++] = nullptr;
 257   }
 258 };
 259
 260 LLVMSymbolizer::LLVMSymbolizer(const char *path, LowLevelAllocator *allocator)
 261     : symbolizer_process_(new(*allocator) LLVMSymbolizerProcess(path)) {}
 262
 263 // Parse a <file>:<line>[:<column>] buffer. The file path may contain colons on
 264 // Windows, so extract tokens from the right hand side first. The column info is
 265 // also optional.
 266 static const char *ParseFileLineInfo(AddressInfo *info, const char *str) {
 267   char *file_line_info = 0;
 268   str = ExtractToken(str, "\n", &file_line_info);
 269   CHECK(file_line_info);
 270
 271   if (uptr size = internal_strlen(file_line_info)) {
 272     char *back = file_line_info + size - 1;
 273     for (int i = 0; i < 2; ++i) {
 274       while (back > file_line_info && IsDigit(*back)) --back;
 275       if (*back != ':' || !IsDigit(back[1])) break;
 276       info->column = info->line;
 277       info->line = internal_atoll(back + 1);
 278       // Truncate the string at the colon to keep only filename.
 279       *back = '\0';
 280       --back;
 281     }
 282     ExtractToken(file_line_info, "", &info->file);
 283   }
 284
 285   InternalFree(file_line_info);
 286   return str;
 287 }
 288
 289 // Parses one or more two-line strings in the following format:
 290 //   <function_name>
 291 //   <file_name>:<line_number>[:<column_number>]
 292 // Used by LLVMSymbolizer, Addr2LinePool and InternalSymbolizer, since all of
 293 // them use the same output format.
 294 void ParseSymbolizePCOutput(const char *str, SymbolizedStack *res) {
 295   bool top_frame = true;
 296   SymbolizedStack *last = res;
 297   while (true) {
 298     char *function_name = 0;
 299     str = ExtractToken(str, "\n", &function_name);
 300     CHECK(function_name);
 301     if (function_name[0] == '\0') {
 302       // There are no more frames.
 303       InternalFree(function_name);
 304       break;
 305     }
 306     SymbolizedStack *cur;
 307     if (top_frame) {
 308       cur = res;
 309       top_frame = false;
 310     } else {
 311       cur = SymbolizedStack::New(res->info.address);
 312       cur->info.FillModuleInfo(res->info.module, res->info.module_offset,
 313                                res->info.module_arch);
 314       last->next = cur;
 315       last = cur;
 316     }
 317
 318     AddressInfo *info = &cur->info;
 319     info->function = function_name;
 320     str = ParseFileLineInfo(info, str);
 321
 322     // Functions and filenames can be "??", in which case we write 0
 323     // to address info to mark that names are unknown.
 324     if (0 == internal_strcmp(info->function, "??")) {
 325       InternalFree(info->function);
 326       info->function = 0;
 327     }
 328     if (0 == internal_strcmp(info->file, "??")) {
 329       InternalFree(info->file);
 330       info->file = 0;
 331     }
 332   }
 333 }
 334
 335 // Parses a two-line string in the following format:
 336 //   <symbol_name>
 337 //   <start_address> <size>
 338 // Used by LLVMSymbolizer and InternalSymbolizer.
 339 void ParseSymbolizeDataOutput(const char *str, DataInfo *info) {
 340   str = ExtractToken(str, "\n", &info->name);
 341   str = ExtractUptr(str, " ", &info->start);
 342   str = ExtractUptr(str, "\n", &info->size);
 343 }
 344
 345 bool LLVMSymbolizer::SymbolizePC(uptr addr, SymbolizedStack *stack) {
 346   AddressInfo *info = &stack->info;
 347   const char *buf = FormatAndSendCommand(
 348       /*is_data*/ false, info->module, info->module_offset, info->module_arch);
 349   if (buf) {
 350     ParseSymbolizePCOutput(buf, stack);
 351     return true;
 352   }
 353   return false;
 354 }
 355
 356 bool LLVMSymbolizer::SymbolizeData(uptr addr, DataInfo *info) {
 357   const char *buf = FormatAndSendCommand(
 358       /*is_data*/ true, info->module, info->module_offset, info->module_arch);
 359   if (buf) {
 360     ParseSymbolizeDataOutput(buf, info);
 361     info->start += (addr - info->module_offset); // Add the base address.
 362     return true;
 363   }
 364   return false;
 365 }
 366
 367 const char *LLVMSymbolizer::FormatAndSendCommand(bool is_data,
 368                                                  const char *module_name,
 369                                                  uptr module_offset,
 370                                                  ModuleArch arch) {
 371   CHECK(module_name);
 372   const char *is_data_str = is_data ? "DATA " : "";
 373   if (arch == kModuleArchUnknown) {
 374     if (internal_snprintf(buffer_, kBufferSize, "%s\"%s\" 0x%zx\n", is_data_str,
 375                           module_name,
 376                           module_offset) >= static_cast<int>(kBufferSize)) {
 377       Report("WARNING: Command buffer too small");
 378       return nullptr;
 379     }
 380   } else {
 381     if (internal_snprintf(buffer_, kBufferSize, "%s\"%s:%s\" 0x%zx\n",
 382                           is_data_str, module_name, ModuleArchToString(arch),
 383                           module_offset) >= static_cast<int>(kBufferSize)) {
 384       Report("WARNING: Command buffer too small");
 385       return nullptr;
 386     }
 387   }
 388   return symbolizer_process_->SendCommand(buffer_);
 389 }
 390
 391 SymbolizerProcess::SymbolizerProcess(const char *path, bool use_forkpty)
 392     : path_(path),
 393       input_fd_(kInvalidFd),
 394       output_fd_(kInvalidFd),
 395       times_restarted_(0),
 396       failed_to_start_(false),
 397       reported_invalid_path_(false),
 398       use_forkpty_(use_forkpty) {
 399   CHECK(path_);
 400   CHECK_NE(path_[0], '\0');
 401 }
 402
 403 static bool IsSameModule(const char* path) {
 404   if (const char* ProcessName = GetProcessName()) {
 405     if (const char* SymbolizerName = StripModuleName(path)) {
 406       return !internal_strcmp(ProcessName, SymbolizerName);
 407     }
 408   }
 409   return false;
 410 }
 411
 412 const char *SymbolizerProcess::SendCommand(const char *command) {
 413   if (failed_to_start_)
 414     return nullptr;
 415   if (IsSameModule(path_)) {
 416     Report("WARNING: Symbolizer was blocked from starting itself!\n");
 417     failed_to_start_ = true;
 418     return nullptr;
 419   }
 420   for (; times_restarted_ < kMaxTimesRestarted; times_restarted_++) {
 421     // Start or restart symbolizer if we failed to send command to it.
 422     if (const char *res = SendCommandImpl(command))
 423       return res;
 424     Restart();
 425   }
 426   if (!failed_to_start_) {
 427     Report("WARNING: Failed to use and restart external symbolizer!\n");
 428     failed_to_start_ = true;
 429   }
 430   return 0;
 431 }
 432
 433 const char *SymbolizerProcess::SendCommandImpl(const char *command) {
 434   if (input_fd_ == kInvalidFd || output_fd_ == kInvalidFd)
 435       return 0;
 436   if (!WriteToSymbolizer(command, internal_strlen(command)))
 437       return 0;
 438   if (!ReadFromSymbolizer(buffer_, kBufferSize))
 439       return 0;
 440   return buffer_;
 441 }
 442
 443 bool SymbolizerProcess::Restart() {
 444   if (input_fd_ != kInvalidFd)
 445     CloseFile(input_fd_);
 446   if (output_fd_ != kInvalidFd)
 447     CloseFile(output_fd_);
 448   return StartSymbolizerSubprocess();
 449 }
 450
 451 bool SymbolizerProcess::ReadFromSymbolizer(char *buffer, uptr max_length) {
 452   if (max_length == 0)
 453     return true;
 454   uptr read_len = 0;
 455   while (true) {
 456     uptr just_read = 0;
 457     bool success = ReadFromFile(input_fd_, buffer + read_len,
 458                                 max_length - read_len - 1, &just_read);
 459     // We can't read 0 bytes, as we don't expect external symbolizer to close
 460     // its stdout.
 461     if (!success || just_read == 0) {
 462       Report("WARNING: Can't read from symbolizer at fd %d\n", input_fd_);
 463       return false;
 464     }
 465     read_len += just_read;
 466     if (ReachedEndOfOutput(buffer, read_len))
 467       break;
 468     if (read_len + 1 == max_length) {
 469       Report("WARNING: Symbolizer buffer too small\n");
 470       read_len = 0;
 471       break;
 472     }
 473   }
 474   buffer[read_len] = '\0';
 475   return true;
 476 }
 477
 478 bool SymbolizerProcess::WriteToSymbolizer(const char *buffer, uptr length) {
 479   if (length == 0)
 480     return true;
 481   uptr write_len = 0;
 482   bool success = WriteToFile(output_fd_, buffer, length, &write_len);
 483   if (!success || write_len != length) {
 484     Report("WARNING: Can't write to symbolizer at fd %d\n", output_fd_);
 485     return false;
 486   }
 487   return true;
 488 }
 489
 490 #endif  // !SANITIZER_SYMBOLIZER_MARKUP
 491
 492 }  // namespace __sanitizer