1 //===-- sanitizer_symbolizer_posix_libcdep.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 AddressSanitizer and ThreadSanitizer 10 // run-time libraries. 11 // POSIX-specific implementation of symbolizer parts. 12 //===----------------------------------------------------------------------===// 13 14 #include "sanitizer_platform.h" 15 #if SANITIZER_POSIX 16 # include <dlfcn.h> // for dlsym() 17 # include <errno.h> 18 # include <stdint.h> 19 # include <stdlib.h> 20 # include <sys/wait.h> 21 # include <unistd.h> 22 23 # include "sanitizer_allocator_internal.h" 24 # include "sanitizer_common.h" 25 # include "sanitizer_file.h" 26 # include "sanitizer_flags.h" 27 # include "sanitizer_internal_defs.h" 28 # include "sanitizer_linux.h" 29 # include "sanitizer_placement_new.h" 30 # include "sanitizer_posix.h" 31 # include "sanitizer_procmaps.h" 32 # include "sanitizer_symbolizer_internal.h" 33 # include "sanitizer_symbolizer_libbacktrace.h" 34 # include "sanitizer_symbolizer_mac.h" 35 36 // C++ demangling function, as required by Itanium C++ ABI. This is weak, 37 // because we do not require a C++ ABI library to be linked to a program 38 // using sanitizers; if it's not present, we'll just use the mangled name. 39 namespace __cxxabiv1 { 40 extern "C" SANITIZER_WEAK_ATTRIBUTE 41 char *__cxa_demangle(const char *mangled, char *buffer, 42 size_t *length, int *status); 43 } 44 45 namespace __sanitizer { 46 47 // Attempts to demangle the name via __cxa_demangle from __cxxabiv1. 48 const char *DemangleCXXABI(const char *name) { 49 // FIXME: __cxa_demangle aggressively insists on allocating memory. 50 // There's not much we can do about that, short of providing our 51 // own demangler (libc++abi's implementation could be adapted so that 52 // it does not allocate). For now, we just call it anyway, and we leak 53 // the returned value. 54 if (&__cxxabiv1::__cxa_demangle) 55 if (const char *demangled_name = 56 __cxxabiv1::__cxa_demangle(name, 0, 0, 0)) 57 return demangled_name; 58 59 return name; 60 } 61 62 // As of now, there are no headers for the Swift runtime. Once they are 63 // present, we will weakly link since we do not require Swift runtime to be 64 // linked. 65 typedef char *(*swift_demangle_ft)(const char *mangledName, 66 size_t mangledNameLength, char *outputBuffer, 67 size_t *outputBufferSize, uint32_t flags); 68 static swift_demangle_ft swift_demangle_f; 69 70 // This must not happen lazily at symbolication time, because dlsym uses 71 // malloc and thread-local storage, which is not a good thing to do during 72 // symbolication. 73 static void InitializeSwiftDemangler() { 74 swift_demangle_f = (swift_demangle_ft)dlsym(RTLD_DEFAULT, "swift_demangle"); 75 } 76 77 // Attempts to demangle a Swift name. The demangler will return nullptr if a 78 // non-Swift name is passed in. 79 const char *DemangleSwift(const char *name) { 80 if (swift_demangle_f) 81 return swift_demangle_f(name, internal_strlen(name), 0, 0, 0); 82 83 return nullptr; 84 } 85 86 const char *DemangleSwiftAndCXX(const char *name) { 87 if (!name) return nullptr; 88 if (const char *swift_demangled_name = DemangleSwift(name)) 89 return swift_demangled_name; 90 return DemangleCXXABI(name); 91 } 92 93 static bool CreateTwoHighNumberedPipes(int *infd_, int *outfd_) { 94 int *infd = NULL; 95 int *outfd = NULL; 96 // The client program may close its stdin and/or stdout and/or stderr 97 // thus allowing socketpair to reuse file descriptors 0, 1 or 2. 98 // In this case the communication between the forked processes may be 99 // broken if either the parent or the child tries to close or duplicate 100 // these descriptors. The loop below produces two pairs of file 101 // descriptors, each greater than 2 (stderr). 102 int sock_pair[5][2]; 103 for (int i = 0; i < 5; i++) { 104 if (pipe(sock_pair[i]) == -1) { 105 for (int j = 0; j < i; j++) { 106 internal_close(sock_pair[j][0]); 107 internal_close(sock_pair[j][1]); 108 } 109 return false; 110 } else if (sock_pair[i][0] > 2 && sock_pair[i][1] > 2) { 111 if (infd == NULL) { 112 infd = sock_pair[i]; 113 } else { 114 outfd = sock_pair[i]; 115 for (int j = 0; j < i; j++) { 116 if (sock_pair[j] == infd) continue; 117 internal_close(sock_pair[j][0]); 118 internal_close(sock_pair[j][1]); 119 } 120 break; 121 } 122 } 123 } 124 CHECK(infd); 125 CHECK(outfd); 126 infd_[0] = infd[0]; 127 infd_[1] = infd[1]; 128 outfd_[0] = outfd[0]; 129 outfd_[1] = outfd[1]; 130 return true; 131 } 132 133 bool SymbolizerProcess::StartSymbolizerSubprocess() { 134 if (!FileExists(path_)) { 135 if (!reported_invalid_path_) { 136 Report("WARNING: invalid path to external symbolizer!\n"); 137 reported_invalid_path_ = true; 138 } 139 return false; 140 } 141 142 const char *argv[kArgVMax]; 143 GetArgV(path_, argv); 144 pid_t pid; 145 146 // Report how symbolizer is being launched for debugging purposes. 147 if (Verbosity() >= 3) { 148 // Only use `Report` for first line so subsequent prints don't get prefixed 149 // with current PID. 150 Report("Launching Symbolizer process: "); 151 for (unsigned index = 0; index < kArgVMax && argv[index]; ++index) 152 Printf("%s ", argv[index]); 153 Printf("\n"); 154 } 155 156 if (use_posix_spawn_) { 157 #if SANITIZER_APPLE 158 fd_t fd = internal_spawn(argv, const_cast<const char **>(GetEnvP()), &pid); 159 if (fd == kInvalidFd) { 160 Report("WARNING: failed to spawn external symbolizer (errno: %d)\n", 161 errno); 162 return false; 163 } 164 165 input_fd_ = fd; 166 output_fd_ = fd; 167 #else // SANITIZER_APPLE 168 UNIMPLEMENTED(); 169 #endif // SANITIZER_APPLE 170 } else { 171 fd_t infd[2] = {}, outfd[2] = {}; 172 if (!CreateTwoHighNumberedPipes(infd, outfd)) { 173 Report("WARNING: Can't create a socket pair to start " 174 "external symbolizer (errno: %d)\n", errno); 175 return false; 176 } 177 178 pid = StartSubprocess(path_, argv, GetEnvP(), /* stdin */ outfd[0], 179 /* stdout */ infd[1]); 180 if (pid < 0) { 181 internal_close(infd[0]); 182 internal_close(outfd[1]); 183 return false; 184 } 185 186 input_fd_ = infd[0]; 187 output_fd_ = outfd[1]; 188 } 189 190 CHECK_GT(pid, 0); 191 192 // Check that symbolizer subprocess started successfully. 193 SleepForMillis(kSymbolizerStartupTimeMillis); 194 if (!IsProcessRunning(pid)) { 195 // Either waitpid failed, or child has already exited. 196 Report("WARNING: external symbolizer didn't start up correctly!\n"); 197 return false; 198 } 199 200 return true; 201 } 202 203 class Addr2LineProcess final : public SymbolizerProcess { 204 public: 205 Addr2LineProcess(const char *path, const char *module_name) 206 : SymbolizerProcess(path), module_name_(internal_strdup(module_name)) {} 207 208 const char *module_name() const { return module_name_; } 209 210 private: 211 void GetArgV(const char *path_to_binary, 212 const char *(&argv)[kArgVMax]) const override { 213 int i = 0; 214 argv[i++] = path_to_binary; 215 if (common_flags()->demangle) 216 argv[i++] = "-C"; 217 if (common_flags()->symbolize_inline_frames) 218 argv[i++] = "-i"; 219 argv[i++] = "-fe"; 220 argv[i++] = module_name_; 221 argv[i++] = nullptr; 222 CHECK_LE(i, kArgVMax); 223 } 224 225 bool ReachedEndOfOutput(const char *buffer, uptr length) const override; 226 227 bool ReadFromSymbolizer() override { 228 if (!SymbolizerProcess::ReadFromSymbolizer()) 229 return false; 230 auto &buff = GetBuff(); 231 // We should cut out output_terminator_ at the end of given buffer, 232 // appended by addr2line to mark the end of its meaningful output. 233 // We cannot scan buffer from it's beginning, because it is legal for it 234 // to start with output_terminator_ in case given offset is invalid. So, 235 // scanning from second character. 236 char *garbage = internal_strstr(buff.data() + 1, output_terminator_); 237 // This should never be NULL since buffer must end up with 238 // output_terminator_. 239 CHECK(garbage); 240 241 // Trim the buffer. 242 uintptr_t new_size = garbage - buff.data(); 243 GetBuff().resize(new_size); 244 GetBuff().push_back('\0'); 245 return true; 246 } 247 248 const char *module_name_; // Owned, leaked. 249 static const char output_terminator_[]; 250 }; 251 252 const char Addr2LineProcess::output_terminator_[] = "??\n??:0\n"; 253 254 bool Addr2LineProcess::ReachedEndOfOutput(const char *buffer, 255 uptr length) const { 256 const size_t kTerminatorLen = sizeof(output_terminator_) - 1; 257 // Skip, if we read just kTerminatorLen bytes, because Addr2Line output 258 // should consist at least of two pairs of lines: 259 // 1. First one, corresponding to given offset to be symbolized 260 // (may be equal to output_terminator_, if offset is not valid). 261 // 2. Second one for output_terminator_, itself to mark the end of output. 262 if (length <= kTerminatorLen) return false; 263 // Addr2Line output should end up with output_terminator_. 264 return !internal_memcmp(buffer + length - kTerminatorLen, 265 output_terminator_, kTerminatorLen); 266 } 267 268 class Addr2LinePool final : public SymbolizerTool { 269 public: 270 explicit Addr2LinePool(const char *addr2line_path, 271 LowLevelAllocator *allocator) 272 : addr2line_path_(addr2line_path), allocator_(allocator) { 273 addr2line_pool_.reserve(16); 274 } 275 276 bool SymbolizePC(uptr addr, SymbolizedStack *stack) override { 277 if (const char *buf = 278 SendCommand(stack->info.module, stack->info.module_offset)) { 279 ParseSymbolizePCOutput(buf, stack); 280 return true; 281 } 282 return false; 283 } 284 285 bool SymbolizeData(uptr addr, DataInfo *info) override { 286 return false; 287 } 288 289 private: 290 const char *SendCommand(const char *module_name, uptr module_offset) { 291 Addr2LineProcess *addr2line = 0; 292 for (uptr i = 0; i < addr2line_pool_.size(); ++i) { 293 if (0 == 294 internal_strcmp(module_name, addr2line_pool_[i]->module_name())) { 295 addr2line = addr2line_pool_[i]; 296 break; 297 } 298 } 299 if (!addr2line) { 300 addr2line = 301 new(*allocator_) Addr2LineProcess(addr2line_path_, module_name); 302 addr2line_pool_.push_back(addr2line); 303 } 304 CHECK_EQ(0, internal_strcmp(module_name, addr2line->module_name())); 305 char buffer[kBufferSize]; 306 internal_snprintf(buffer, kBufferSize, "0x%zx\n0x%zx\n", 307 module_offset, dummy_address_); 308 return addr2line->SendCommand(buffer); 309 } 310 311 static const uptr kBufferSize = 64; 312 const char *addr2line_path_; 313 LowLevelAllocator *allocator_; 314 InternalMmapVector<Addr2LineProcess*> addr2line_pool_; 315 static const uptr dummy_address_ = 316 FIRST_32_SECOND_64(UINT32_MAX, UINT64_MAX); 317 }; 318 319 # if SANITIZER_SUPPORTS_WEAK_HOOKS 320 extern "C" { 321 SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE bool 322 __sanitizer_symbolize_code(const char *ModuleName, u64 ModuleOffset, 323 char *Buffer, int MaxLength); 324 SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE bool 325 __sanitizer_symbolize_data(const char *ModuleName, u64 ModuleOffset, 326 char *Buffer, int MaxLength); 327 SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE void 328 __sanitizer_symbolize_flush(); 329 SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE int 330 __sanitizer_symbolize_demangle(const char *Name, char *Buffer, int MaxLength); 331 SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE bool 332 __sanitizer_symbolize_set_demangle(bool Demangle); 333 SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE bool 334 __sanitizer_symbolize_set_inline_frames(bool InlineFrames); 335 } // extern "C" 336 337 class InternalSymbolizer final : public SymbolizerTool { 338 public: 339 static InternalSymbolizer *get(LowLevelAllocator *alloc) { 340 if (__sanitizer_symbolize_set_demangle) 341 CHECK(__sanitizer_symbolize_set_demangle(common_flags()->demangle)); 342 if (__sanitizer_symbolize_set_inline_frames) 343 CHECK(__sanitizer_symbolize_set_inline_frames( 344 common_flags()->symbolize_inline_frames)); 345 if (__sanitizer_symbolize_code && __sanitizer_symbolize_data) 346 return new (*alloc) InternalSymbolizer(); 347 return 0; 348 } 349 350 bool SymbolizePC(uptr addr, SymbolizedStack *stack) override { 351 bool result = __sanitizer_symbolize_code( 352 stack->info.module, stack->info.module_offset, buffer_, kBufferSize); 353 if (result) 354 ParseSymbolizePCOutput(buffer_, stack); 355 return result; 356 } 357 358 bool SymbolizeData(uptr addr, DataInfo *info) override { 359 bool result = __sanitizer_symbolize_data(info->module, info->module_offset, 360 buffer_, kBufferSize); 361 if (result) { 362 ParseSymbolizeDataOutput(buffer_, info); 363 info->start += (addr - info->module_offset); // Add the base address. 364 } 365 return result; 366 } 367 368 void Flush() override { 369 if (__sanitizer_symbolize_flush) 370 __sanitizer_symbolize_flush(); 371 } 372 373 const char *Demangle(const char *name) override { 374 if (__sanitizer_symbolize_demangle) { 375 for (uptr res_length = 1024; 376 res_length <= InternalSizeClassMap::kMaxSize;) { 377 char *res_buff = static_cast<char *>(InternalAlloc(res_length)); 378 uptr req_length = 379 __sanitizer_symbolize_demangle(name, res_buff, res_length); 380 if (req_length > res_length) { 381 res_length = req_length + 1; 382 InternalFree(res_buff); 383 continue; 384 } 385 return res_buff; 386 } 387 } 388 return name; 389 } 390 391 private: 392 InternalSymbolizer() {} 393 394 static const int kBufferSize = 16 * 1024; 395 char buffer_[kBufferSize]; 396 }; 397 # else // SANITIZER_SUPPORTS_WEAK_HOOKS 398 399 class InternalSymbolizer final : public SymbolizerTool { 400 public: 401 static InternalSymbolizer *get(LowLevelAllocator *alloc) { return 0; } 402 }; 403 404 # endif // SANITIZER_SUPPORTS_WEAK_HOOKS 405 406 const char *Symbolizer::PlatformDemangle(const char *name) { 407 return DemangleSwiftAndCXX(name); 408 } 409 410 static SymbolizerTool *ChooseExternalSymbolizer(LowLevelAllocator *allocator) { 411 const char *path = common_flags()->external_symbolizer_path; 412 413 if (path && internal_strchr(path, '%')) { 414 char *new_path = (char *)InternalAlloc(kMaxPathLength); 415 SubstituteForFlagValue(path, new_path, kMaxPathLength); 416 path = new_path; 417 } 418 419 const char *binary_name = path ? StripModuleName(path) : ""; 420 static const char kLLVMSymbolizerPrefix[] = "llvm-symbolizer"; 421 if (path && path[0] == '\0') { 422 VReport(2, "External symbolizer is explicitly disabled.\n"); 423 return nullptr; 424 } else if (!internal_strncmp(binary_name, kLLVMSymbolizerPrefix, 425 internal_strlen(kLLVMSymbolizerPrefix))) { 426 VReport(2, "Using llvm-symbolizer at user-specified path: %s\n", path); 427 return new(*allocator) LLVMSymbolizer(path, allocator); 428 } else if (!internal_strcmp(binary_name, "atos")) { 429 #if SANITIZER_APPLE 430 VReport(2, "Using atos at user-specified path: %s\n", path); 431 return new(*allocator) AtosSymbolizer(path, allocator); 432 #else // SANITIZER_APPLE 433 Report("ERROR: Using `atos` is only supported on Darwin.\n"); 434 Die(); 435 #endif // SANITIZER_APPLE 436 } else if (!internal_strcmp(binary_name, "addr2line")) { 437 VReport(2, "Using addr2line at user-specified path: %s\n", path); 438 return new(*allocator) Addr2LinePool(path, allocator); 439 } else if (path) { 440 Report("ERROR: External symbolizer path is set to '%s' which isn't " 441 "a known symbolizer. Please set the path to the llvm-symbolizer " 442 "binary or other known tool.\n", path); 443 Die(); 444 } 445 446 // Otherwise symbolizer program is unknown, let's search $PATH 447 CHECK(path == nullptr); 448 #if SANITIZER_APPLE 449 if (const char *found_path = FindPathToBinary("atos")) { 450 VReport(2, "Using atos found at: %s\n", found_path); 451 return new(*allocator) AtosSymbolizer(found_path, allocator); 452 } 453 #endif // SANITIZER_APPLE 454 if (const char *found_path = FindPathToBinary("llvm-symbolizer")) { 455 VReport(2, "Using llvm-symbolizer found at: %s\n", found_path); 456 return new(*allocator) LLVMSymbolizer(found_path, allocator); 457 } 458 if (common_flags()->allow_addr2line) { 459 if (const char *found_path = FindPathToBinary("addr2line")) { 460 VReport(2, "Using addr2line found at: %s\n", found_path); 461 return new(*allocator) Addr2LinePool(found_path, allocator); 462 } 463 } 464 return nullptr; 465 } 466 467 static void ChooseSymbolizerTools(IntrusiveList<SymbolizerTool> *list, 468 LowLevelAllocator *allocator) { 469 if (!common_flags()->symbolize) { 470 VReport(2, "Symbolizer is disabled.\n"); 471 return; 472 } 473 if (IsAllocatorOutOfMemory()) { 474 VReport(2, "Cannot use internal symbolizer: out of memory\n"); 475 } else if (SymbolizerTool *tool = InternalSymbolizer::get(allocator)) { 476 VReport(2, "Using internal symbolizer.\n"); 477 list->push_back(tool); 478 return; 479 } 480 if (SymbolizerTool *tool = LibbacktraceSymbolizer::get(allocator)) { 481 VReport(2, "Using libbacktrace symbolizer.\n"); 482 list->push_back(tool); 483 return; 484 } 485 486 if (SymbolizerTool *tool = ChooseExternalSymbolizer(allocator)) { 487 list->push_back(tool); 488 } 489 490 #if SANITIZER_APPLE 491 VReport(2, "Using dladdr symbolizer.\n"); 492 list->push_back(new(*allocator) DlAddrSymbolizer()); 493 #endif // SANITIZER_APPLE 494 } 495 496 Symbolizer *Symbolizer::PlatformInit() { 497 IntrusiveList<SymbolizerTool> list; 498 list.clear(); 499 ChooseSymbolizerTools(&list, &symbolizer_allocator_); 500 return new(symbolizer_allocator_) Symbolizer(list); 501 } 502 503 void Symbolizer::LateInitialize() { 504 Symbolizer::GetOrInit(); 505 InitializeSwiftDemangler(); 506 } 507 508 } // namespace __sanitizer 509 510 #endif // SANITIZER_POSIX 511