535 lines · cpp
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-exception6//7//===----------------------------------------------------------------------===//8//9// This file is shared between AddressSanitizer and ThreadSanitizer10// run-time libraries.11// POSIX-specific implementation of symbolizer parts.12//===----------------------------------------------------------------------===//13 14#include "sanitizer_platform.h"15#include "sanitizer_symbolizer_markup.h"16#if SANITIZER_POSIX17# include <dlfcn.h> // for dlsym()18# include <errno.h>19# include <stdint.h>20# include <stdlib.h>21# include <sys/wait.h>22# include <unistd.h>23 24# include "sanitizer_allocator_internal.h"25# include "sanitizer_common.h"26# include "sanitizer_file.h"27# include "sanitizer_flags.h"28# include "sanitizer_internal_defs.h"29# include "sanitizer_linux.h"30# include "sanitizer_placement_new.h"31# include "sanitizer_posix.h"32# include "sanitizer_procmaps.h"33# include "sanitizer_symbolizer_internal.h"34# include "sanitizer_symbolizer_libbacktrace.h"35# include "sanitizer_symbolizer_mac.h"36 37// C++ demangling function, as required by Itanium C++ ABI. This is weak,38// because we do not require a C++ ABI library to be linked to a program39// using sanitizers; if it's not present, we'll just use the mangled name.40namespace __cxxabiv1 {41extern "C" SANITIZER_WEAK_ATTRIBUTE char *__cxa_demangle(const char *mangled,42 char *buffer,43 size_t *length,44 int *status);45}46 47namespace __sanitizer {48 49// Attempts to demangle the name via __cxa_demangle from __cxxabiv1.50const char *DemangleCXXABI(const char *name) {51 // FIXME: __cxa_demangle aggressively insists on allocating memory.52 // There's not much we can do about that, short of providing our53 // own demangler (libc++abi's implementation could be adapted so that54 // it does not allocate). For now, we just call it anyway, and we leak55 // the returned value.56 if (&__cxxabiv1::__cxa_demangle)57 if (const char *demangled_name = __cxxabiv1::__cxa_demangle(name, 0, 0, 0))58 return demangled_name;59 60 return nullptr;61}62 63// As of now, there are no headers for the Swift runtime. Once they are64// present, we will weakly link since we do not require Swift runtime to be65// linked.66typedef char *(*swift_demangle_ft)(const char *mangledName,67 size_t mangledNameLength, char *outputBuffer,68 size_t *outputBufferSize, uint32_t flags);69static swift_demangle_ft swift_demangle_f;70 71// This must not happen lazily at symbolication time, because dlsym uses72// malloc and thread-local storage, which is not a good thing to do during73// symbolication.74static void InitializeSwiftDemangler() {75 swift_demangle_f = (swift_demangle_ft)dlsym(RTLD_DEFAULT, "swift_demangle");76}77 78// Attempts to demangle a Swift name. The demangler will return nullptr if a79// non-Swift name is passed in.80const char *DemangleSwift(const char *name) {81 if (swift_demangle_f)82 return swift_demangle_f(name, internal_strlen(name), 0, 0, 0);83 84 return nullptr;85}86 87const char *DemangleSwiftAndCXX(const char *name) {88 if (!name)89 return nullptr;90 if (const char *swift_demangled_name = DemangleSwift(name))91 return swift_demangled_name;92 return DemangleCXXABI(name);93}94 95static bool CreateTwoHighNumberedPipes(int *infd_, int *outfd_) {96 int *infd = NULL;97 int *outfd = NULL;98 // The client program may close its stdin and/or stdout and/or stderr99 // thus allowing socketpair to reuse file descriptors 0, 1 or 2.100 // In this case the communication between the forked processes may be101 // broken if either the parent or the child tries to close or duplicate102 // these descriptors. The loop below produces two pairs of file103 // descriptors, each greater than 2 (stderr).104 int sock_pair[5][2];105 for (int i = 0; i < 5; i++) {106 if (pipe(sock_pair[i]) == -1) {107 for (int j = 0; j < i; j++) {108 internal_close(sock_pair[j][0]);109 internal_close(sock_pair[j][1]);110 }111 return false;112 } else if (sock_pair[i][0] > 2 && sock_pair[i][1] > 2) {113 if (infd == NULL) {114 infd = sock_pair[i];115 } else {116 outfd = sock_pair[i];117 for (int j = 0; j < i; j++) {118 if (sock_pair[j] == infd)119 continue;120 internal_close(sock_pair[j][0]);121 internal_close(sock_pair[j][1]);122 }123 break;124 }125 }126 }127 CHECK(infd);128 CHECK(outfd);129 infd_[0] = infd[0];130 infd_[1] = infd[1];131 outfd_[0] = outfd[0];132 outfd_[1] = outfd[1];133 return true;134}135 136bool SymbolizerProcess::StartSymbolizerSubprocess() {137 if (!FileExists(path_)) {138 if (!reported_invalid_path_) {139 Report("WARNING: invalid path to external symbolizer!\n");140 reported_invalid_path_ = true;141 }142 return false;143 }144 145 const char *argv[kArgVMax];146 GetArgV(path_, argv);147 pid_t pid;148 149 // Report how symbolizer is being launched for debugging purposes.150 if (Verbosity() >= 3) {151 // Only use `Report` for first line so subsequent prints don't get prefixed152 // with current PID.153 Report("Launching Symbolizer process: ");154 for (unsigned index = 0; index < kArgVMax && argv[index]; ++index)155 Printf("%s ", argv[index]);156 Printf("\n");157 }158 159 if (use_posix_spawn_) {160# if SANITIZER_APPLE161 fd_t fd = internal_spawn(argv, const_cast<const char **>(GetEnvP()), &pid);162 if (fd == kInvalidFd) {163 Report("WARNING: failed to spawn external symbolizer (errno: %d)\n",164 errno);165 return false;166 }167 168 input_fd_ = fd;169 output_fd_ = fd;170# else // SANITIZER_APPLE171 UNIMPLEMENTED();172# endif // SANITIZER_APPLE173 } else {174 fd_t infd[2] = {}, outfd[2] = {};175 if (!CreateTwoHighNumberedPipes(infd, outfd)) {176 Report(177 "WARNING: Can't create a socket pair to start "178 "external symbolizer (errno: %d)\n",179 errno);180 return false;181 }182 183 pid = StartSubprocess(path_, argv, GetEnvP(), /* stdin */ outfd[0],184 /* stdout */ infd[1]);185 if (pid < 0) {186 internal_close(infd[0]);187 internal_close(outfd[1]);188 return false;189 }190 191 input_fd_ = infd[0];192 output_fd_ = outfd[1];193 }194 195 CHECK_GT(pid, 0);196 197 // Check that symbolizer subprocess started successfully.198 SleepForMillis(kSymbolizerStartupTimeMillis);199 if (!IsProcessRunning(pid)) {200 // Either waitpid failed, or child has already exited.201 Report("WARNING: external symbolizer didn't start up correctly!\n");202 return false;203 }204 205 return true;206}207 208class Addr2LineProcess final : public SymbolizerProcess {209 public:210 Addr2LineProcess(const char *path, const char *module_name)211 : SymbolizerProcess(path), module_name_(internal_strdup(module_name)) {}212 213 const char *module_name() const { return module_name_; }214 215 private:216 void GetArgV(const char *path_to_binary,217 const char *(&argv)[kArgVMax]) const override {218 int i = 0;219 argv[i++] = path_to_binary;220 if (common_flags()->demangle)221 argv[i++] = "-C";222 if (common_flags()->symbolize_inline_frames)223 argv[i++] = "-i";224 argv[i++] = "-fe";225 argv[i++] = module_name_;226 argv[i++] = nullptr;227 CHECK_LE(i, kArgVMax);228 }229 230 bool ReachedEndOfOutput(const char *buffer, uptr length) const override;231 232 bool ReadFromSymbolizer() override {233 if (!SymbolizerProcess::ReadFromSymbolizer())234 return false;235 auto &buff = GetBuff();236 // We should cut out output_terminator_ at the end of given buffer,237 // appended by addr2line to mark the end of its meaningful output.238 // We cannot scan buffer from it's beginning, because it is legal for it239 // to start with output_terminator_ in case given offset is invalid. So,240 // scanning from second character.241 char *garbage = internal_strstr(buff.data() + 1, output_terminator_);242 // This should never be NULL since buffer must end up with243 // output_terminator_.244 CHECK(garbage);245 246 // Trim the buffer.247 uintptr_t new_size = garbage - buff.data();248 GetBuff().resize(new_size);249 GetBuff().push_back('\0');250 return true;251 }252 253 const char *module_name_; // Owned, leaked.254 static const char output_terminator_[];255};256 257const char Addr2LineProcess::output_terminator_[] = "??\n??:0\n";258 259bool Addr2LineProcess::ReachedEndOfOutput(const char *buffer,260 uptr length) const {261 const size_t kTerminatorLen = sizeof(output_terminator_) - 1;262 // Skip, if we read just kTerminatorLen bytes, because Addr2Line output263 // should consist at least of two pairs of lines:264 // 1. First one, corresponding to given offset to be symbolized265 // (may be equal to output_terminator_, if offset is not valid).266 // 2. Second one for output_terminator_, itself to mark the end of output.267 if (length <= kTerminatorLen)268 return false;269 // Addr2Line output should end up with output_terminator_.270 return !internal_memcmp(buffer + length - kTerminatorLen, output_terminator_,271 kTerminatorLen);272}273 274class Addr2LinePool final : public SymbolizerTool {275 public:276 explicit Addr2LinePool(const char *addr2line_path,277 LowLevelAllocator *allocator)278 : addr2line_path_(addr2line_path), allocator_(allocator) {279 addr2line_pool_.reserve(16);280 }281 282 bool SymbolizePC(uptr addr, SymbolizedStack *stack) override {283 if (const char *buf =284 SendCommand(stack->info.module, stack->info.module_offset)) {285 ParseSymbolizePCOutput(buf, stack);286 return true;287 }288 return false;289 }290 291 bool SymbolizeData(uptr addr, DataInfo *info) override { return false; }292 293 private:294 const char *SendCommand(const char *module_name, uptr module_offset) {295 Addr2LineProcess *addr2line = 0;296 for (uptr i = 0; i < addr2line_pool_.size(); ++i) {297 if (0 ==298 internal_strcmp(module_name, addr2line_pool_[i]->module_name())) {299 addr2line = addr2line_pool_[i];300 break;301 }302 }303 if (!addr2line) {304 addr2line =305 new (*allocator_) Addr2LineProcess(addr2line_path_, module_name);306 addr2line_pool_.push_back(addr2line);307 }308 CHECK_EQ(0, internal_strcmp(module_name, addr2line->module_name()));309 char buffer[kBufferSize];310 internal_snprintf(buffer, kBufferSize, "0x%zx\n0x%zx\n", module_offset,311 dummy_address_);312 return addr2line->SendCommand(buffer);313 }314 315 static const uptr kBufferSize = 64;316 const char *addr2line_path_;317 LowLevelAllocator *allocator_;318 InternalMmapVector<Addr2LineProcess *> addr2line_pool_;319 static const uptr dummy_address_ = FIRST_32_SECOND_64(UINT32_MAX, UINT64_MAX);320};321 322# if SANITIZER_SUPPORTS_WEAK_HOOKS323extern "C" {324SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE bool325__sanitizer_symbolize_code(const char *ModuleName, u64 ModuleOffset,326 char *Buffer, int MaxLength);327SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE bool328__sanitizer_symbolize_data(const char *ModuleName, u64 ModuleOffset,329 char *Buffer, int MaxLength);330SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE bool331__sanitizer_symbolize_frame(const char *ModuleName, u64 ModuleOffset,332 char *Buffer, int MaxLength);333SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE void334__sanitizer_symbolize_flush();335SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE bool336__sanitizer_symbolize_demangle(const char *Name, char *Buffer, int MaxLength);337SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE bool338__sanitizer_symbolize_set_demangle(bool Demangle);339SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE bool340__sanitizer_symbolize_set_inline_frames(bool InlineFrames);341} // extern "C"342 343class InternalSymbolizer final : public SymbolizerTool {344 public:345 static InternalSymbolizer *get(LowLevelAllocator *alloc) {346 // These one is the most used one, so we will use it to detect a presence of347 // internal symbolizer.348 if (&__sanitizer_symbolize_code == nullptr)349 return nullptr;350 CHECK(__sanitizer_symbolize_set_demangle(common_flags()->demangle));351 CHECK(__sanitizer_symbolize_set_inline_frames(352 common_flags()->symbolize_inline_frames));353 return new (*alloc) InternalSymbolizer();354 }355 356 bool SymbolizePC(uptr addr, SymbolizedStack *stack) override {357 bool result = __sanitizer_symbolize_code(stack->info.module,358 stack->info.module_offset, buffer_,359 sizeof(buffer_));360 if (result)361 ParseSymbolizePCOutput(buffer_, stack);362 return result;363 }364 365 bool SymbolizeData(uptr addr, DataInfo *info) override {366 bool result = __sanitizer_symbolize_data(info->module, info->module_offset,367 buffer_, sizeof(buffer_));368 if (result) {369 ParseSymbolizeDataOutput(buffer_, info);370 info->start += (addr - info->module_offset); // Add the base address.371 }372 return result;373 }374 375 bool SymbolizeFrame(uptr addr, FrameInfo *info) override {376 bool result = __sanitizer_symbolize_frame(info->module, info->module_offset,377 buffer_, sizeof(buffer_));378 if (result)379 ParseSymbolizeFrameOutput(buffer_, &info->locals);380 return result;381 }382 383 void Flush() override { __sanitizer_symbolize_flush(); }384 385 const char *Demangle(const char *name) override {386 if (__sanitizer_symbolize_demangle(name, buffer_, sizeof(buffer_))) {387 char *res_buff = nullptr;388 ExtractToken(buffer_, "", &res_buff);389 return res_buff;390 }391 return nullptr;392 }393 394 private:395 InternalSymbolizer() {}396 397 char buffer_[16 * 1024];398};399# else // SANITIZER_SUPPORTS_WEAK_HOOKS400 401class InternalSymbolizer final : public SymbolizerTool {402 public:403 static InternalSymbolizer *get(LowLevelAllocator *alloc) { return 0; }404};405 406# endif // SANITIZER_SUPPORTS_WEAK_HOOKS407 408const char *Symbolizer::PlatformDemangle(const char *name) {409 return DemangleSwiftAndCXX(name);410}411 412static SymbolizerTool *ChooseExternalSymbolizer(LowLevelAllocator *allocator) {413 const char *path = common_flags()->external_symbolizer_path;414 415 if (path && internal_strchr(path, '%')) {416 char *new_path = (char *)InternalAlloc(kMaxPathLength);417 SubstituteForFlagValue(path, new_path, kMaxPathLength);418 path = new_path;419 }420 421 const char *binary_name = path ? StripModuleName(path) : "";422 static const char kLLVMSymbolizerPrefix[] = "llvm-symbolizer";423 if (path && path[0] == '\0') {424 VReport(2, "External symbolizer is explicitly disabled.\n");425 return nullptr;426 } else if (!internal_strncmp(binary_name, kLLVMSymbolizerPrefix,427 internal_strlen(kLLVMSymbolizerPrefix))) {428 VReport(2, "Using llvm-symbolizer at user-specified path: %s\n", path);429 return new (*allocator) LLVMSymbolizer(path, allocator);430 } else if (!internal_strcmp(binary_name, "atos")) {431# if SANITIZER_APPLE432 VReport(2, "Using atos at user-specified path: %s\n", path);433 return new (*allocator) AtosSymbolizer(path, allocator);434# else // SANITIZER_APPLE435 Report("ERROR: Using `atos` is only supported on Darwin.\n");436 Die();437# endif // SANITIZER_APPLE438 } else if (!internal_strcmp(binary_name, "addr2line")) {439 VReport(2, "Using addr2line at user-specified path: %s\n", path);440 return new (*allocator) Addr2LinePool(path, allocator);441 } else if (path) {442 Report(443 "ERROR: External symbolizer path is set to '%s' which isn't "444 "a known symbolizer. Please set the path to the llvm-symbolizer "445 "binary or other known tool.\n",446 path);447 Die();448 }449 450 // Otherwise symbolizer program is unknown, let's search $PATH451# ifdef SANITIZER_DISABLE_SYMBOLIZER_PATH_SEARCH452 VReport(2,453 "Symbolizer path search is disabled in the runtime "454 "build configuration.\n");455 return nullptr;456# else457 CHECK(path == nullptr);458# if SANITIZER_APPLE459 if (const char *found_path = FindPathToBinary("atos")) {460 VReport(2, "Using atos found at: %s\n", found_path);461 return new (*allocator) AtosSymbolizer(found_path, allocator);462 }463# endif // SANITIZER_APPLE464 if (const char *found_path = FindPathToBinary("llvm-symbolizer")) {465 VReport(2, "Using llvm-symbolizer found at: %s\n", found_path);466 return new (*allocator) LLVMSymbolizer(found_path, allocator);467 }468 if (common_flags()->allow_addr2line) {469 if (const char *found_path = FindPathToBinary("addr2line")) {470 VReport(2, "Using addr2line found at: %s\n", found_path);471 return new (*allocator) Addr2LinePool(found_path, allocator);472 }473 }474 return nullptr;475# endif // SANITIZER_DISABLE_SYMBOLIZER_PATH_SEARCH476}477 478static void ChooseSymbolizerTools(IntrusiveList<SymbolizerTool> *list,479 LowLevelAllocator *allocator) {480 if (!common_flags()->symbolize) {481 VReport(2, "Symbolizer is disabled.\n");482 return;483 }484 if (common_flags()->enable_symbolizer_markup) {485 VReport(2, "Using symbolizer markup");486 SymbolizerTool *tool = new (*allocator) MarkupSymbolizerTool();487 CHECK(tool);488 list->push_back(tool);489 }490 if (IsAllocatorOutOfMemory()) {491 VReport(2, "Cannot use internal symbolizer: out of memory\n");492 } else if (SymbolizerTool *tool = InternalSymbolizer::get(allocator)) {493 VReport(2, "Using internal symbolizer.\n");494 list->push_back(tool);495 return;496 }497 if (SymbolizerTool *tool = LibbacktraceSymbolizer::get(allocator)) {498 VReport(2, "Using libbacktrace symbolizer.\n");499 list->push_back(tool);500 return;501 }502 503 if (SymbolizerTool *tool = ChooseExternalSymbolizer(allocator)) {504 list->push_back(tool);505 }506 507# if SANITIZER_APPLE508 if (list->empty()) {509 Report(510 "WARN: No external symbolizers found. Symbols may be missing or "511 "unreliable.\n");512 Report(513 "HINT: Is PATH set? Does sandbox allow file-read of /usr/bin/atos?\n");514 }515 VReport(2, "Using dladdr symbolizer.\n");516 list->push_back(new (*allocator) DlAddrSymbolizer());517# endif // SANITIZER_APPLE518}519 520Symbolizer *Symbolizer::PlatformInit() {521 IntrusiveList<SymbolizerTool> list;522 list.clear();523 ChooseSymbolizerTools(&list, &symbolizer_allocator_);524 return new (symbolizer_allocator_) Symbolizer(list);525}526 527void Symbolizer::LateInitialize() {528 Symbolizer::GetOrInit();529 InitializeSwiftDemangler();530}531 532} // namespace __sanitizer533 534#endif // SANITIZER_POSIX535