1 //===-- sanitizer_symbolizer_posix_libcdep.cpp ----------------------------===//
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
7 //===----------------------------------------------------------------------===//
9 // This file is shared between AddressSanitizer and ThreadSanitizer
10 // run-time libraries.
11 // POSIX-specific implementation of symbolizer parts.
12 //===----------------------------------------------------------------------===//
14 #include "sanitizer_platform.h"
16 #include "sanitizer_allocator_internal.h"
17 #include "sanitizer_common.h"
18 #include "sanitizer_file.h"
19 #include "sanitizer_flags.h"
20 #include "sanitizer_internal_defs.h"
21 #include "sanitizer_linux.h"
22 #include "sanitizer_placement_new.h"
23 #include "sanitizer_posix.h"
24 #include "sanitizer_procmaps.h"
25 #include "sanitizer_symbolizer_internal.h"
26 #include "sanitizer_symbolizer_libbacktrace.h"
27 #include "sanitizer_symbolizer_mac.h"
29 #include <dlfcn.h> // for dlsym()
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);
45 namespace __sanitizer {
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;
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
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;
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
73 static void InitializeSwiftDemangler() {
74 swift_demangle_f = (swift_demangle_ft)dlsym(RTLD_DEFAULT, "swift_demangle");
75 (void)dlerror(); // Cleanup error message in case of failure
78 // Attempts to demangle a Swift name. The demangler will return nullptr if a
79 // non-Swift name is passed in.
80 const char *DemangleSwift(const char *name) {
81 if (!name) return nullptr;
83 // Check if we are dealing with a Swift mangled name first.
84 if (name[0] != '_' || name[1] != 'T') {
89 return swift_demangle_f(name, internal_strlen(name), 0, 0, 0);
94 const char *DemangleSwiftAndCXX(const char *name) {
95 if (!name) return nullptr;
96 if (const char *swift_demangled_name = DemangleSwift(name))
97 return swift_demangled_name;
98 return DemangleCXXABI(name);
101 static bool CreateTwoHighNumberedPipes(int *infd_, int *outfd_) {
104 // The client program may close its stdin and/or stdout and/or stderr
105 // thus allowing socketpair to reuse file descriptors 0, 1 or 2.
106 // In this case the communication between the forked processes may be
107 // broken if either the parent or the child tries to close or duplicate
108 // these descriptors. The loop below produces two pairs of file
109 // descriptors, each greater than 2 (stderr).
111 for (int i = 0; i < 5; i++) {
112 if (pipe(sock_pair[i]) == -1) {
113 for (int j = 0; j < i; j++) {
114 internal_close(sock_pair[j][0]);
115 internal_close(sock_pair[j][1]);
118 } else if (sock_pair[i][0] > 2 && sock_pair[i][1] > 2) {
122 outfd = sock_pair[i];
123 for (int j = 0; j < i; j++) {
124 if (sock_pair[j] == infd) continue;
125 internal_close(sock_pair[j][0]);
126 internal_close(sock_pair[j][1]);
136 outfd_[0] = outfd[0];
137 outfd_[1] = outfd[1];
141 bool SymbolizerProcess::StartSymbolizerSubprocess() {
142 if (!FileExists(path_)) {
143 if (!reported_invalid_path_) {
144 Report("WARNING: invalid path to external symbolizer!\n");
145 reported_invalid_path_ = true;
150 const char *argv[kArgVMax];
151 GetArgV(path_, argv);
154 if (use_posix_spawn_) {
156 fd_t fd = internal_spawn(argv, &pid);
157 if (fd == kInvalidFd) {
158 Report("WARNING: failed to spawn external symbolizer (errno: %d)\n",
165 #else // SANITIZER_MAC
167 #endif // SANITIZER_MAC
169 fd_t infd[2] = {}, outfd[2] = {};
170 if (!CreateTwoHighNumberedPipes(infd, outfd)) {
171 Report("WARNING: Can't create a socket pair to start "
172 "external symbolizer (errno: %d)\n", errno);
176 pid = StartSubprocess(path_, argv, /* stdin */ outfd[0],
177 /* stdout */ infd[1]);
179 internal_close(infd[0]);
180 internal_close(outfd[1]);
185 output_fd_ = outfd[1];
190 // Check that symbolizer subprocess started successfully.
191 SleepForMillis(kSymbolizerStartupTimeMillis);
192 if (!IsProcessRunning(pid)) {
193 // Either waitpid failed, or child has already exited.
194 Report("WARNING: external symbolizer didn't start up correctly!\n");
201 class Addr2LineProcess : public SymbolizerProcess {
203 Addr2LineProcess(const char *path, const char *module_name)
204 : SymbolizerProcess(path), module_name_(internal_strdup(module_name)) {}
206 const char *module_name() const { return module_name_; }
209 void GetArgV(const char *path_to_binary,
210 const char *(&argv)[kArgVMax]) const override {
212 argv[i++] = path_to_binary;
214 argv[i++] = module_name_;
218 bool ReachedEndOfOutput(const char *buffer, uptr length) const override;
220 bool ReadFromSymbolizer(char *buffer, uptr max_length) override {
221 if (!SymbolizerProcess::ReadFromSymbolizer(buffer, max_length))
223 // The returned buffer is empty when output is valid, but exceeds
227 // We should cut out output_terminator_ at the end of given buffer,
228 // appended by addr2line to mark the end of its meaningful output.
229 // We cannot scan buffer from it's beginning, because it is legal for it
230 // to start with output_terminator_ in case given offset is invalid. So,
231 // scanning from second character.
232 char *garbage = internal_strstr(buffer + 1, output_terminator_);
233 // This should never be NULL since buffer must end up with
234 // output_terminator_.
241 const char *module_name_; // Owned, leaked.
242 static const char output_terminator_[];
245 const char Addr2LineProcess::output_terminator_[] = "??\n??:0\n";
247 bool Addr2LineProcess::ReachedEndOfOutput(const char *buffer,
249 const size_t kTerminatorLen = sizeof(output_terminator_) - 1;
250 // Skip, if we read just kTerminatorLen bytes, because Addr2Line output
251 // should consist at least of two pairs of lines:
252 // 1. First one, corresponding to given offset to be symbolized
253 // (may be equal to output_terminator_, if offset is not valid).
254 // 2. Second one for output_terminator_, itself to mark the end of output.
255 if (length <= kTerminatorLen) return false;
256 // Addr2Line output should end up with output_terminator_.
257 return !internal_memcmp(buffer + length - kTerminatorLen,
258 output_terminator_, kTerminatorLen);
261 class Addr2LinePool : public SymbolizerTool {
263 explicit Addr2LinePool(const char *addr2line_path,
264 LowLevelAllocator *allocator)
265 : addr2line_path_(addr2line_path), allocator_(allocator) {
266 addr2line_pool_.reserve(16);
269 bool SymbolizePC(uptr addr, SymbolizedStack *stack) override {
270 if (const char *buf =
271 SendCommand(stack->info.module, stack->info.module_offset)) {
272 ParseSymbolizePCOutput(buf, stack);
278 bool SymbolizeData(uptr addr, DataInfo *info) override {
283 const char *SendCommand(const char *module_name, uptr module_offset) {
284 Addr2LineProcess *addr2line = 0;
285 for (uptr i = 0; i < addr2line_pool_.size(); ++i) {
287 internal_strcmp(module_name, addr2line_pool_[i]->module_name())) {
288 addr2line = addr2line_pool_[i];
294 new(*allocator_) Addr2LineProcess(addr2line_path_, module_name);
295 addr2line_pool_.push_back(addr2line);
297 CHECK_EQ(0, internal_strcmp(module_name, addr2line->module_name()));
298 char buffer[kBufferSize];
299 internal_snprintf(buffer, kBufferSize, "0x%zx\n0x%zx\n",
300 module_offset, dummy_address_);
301 return addr2line->SendCommand(buffer);
304 static const uptr kBufferSize = 64;
305 const char *addr2line_path_;
306 LowLevelAllocator *allocator_;
307 InternalMmapVector<Addr2LineProcess*> addr2line_pool_;
308 static const uptr dummy_address_ =
309 FIRST_32_SECOND_64(UINT32_MAX, UINT64_MAX);
312 #if SANITIZER_SUPPORTS_WEAK_HOOKS
314 SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
315 bool __sanitizer_symbolize_code(const char *ModuleName, u64 ModuleOffset,
316 char *Buffer, int MaxLength);
317 SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
318 bool __sanitizer_symbolize_data(const char *ModuleName, u64 ModuleOffset,
319 char *Buffer, int MaxLength);
320 SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
321 void __sanitizer_symbolize_flush();
322 SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
323 int __sanitizer_symbolize_demangle(const char *Name, char *Buffer,
327 class InternalSymbolizer : public SymbolizerTool {
329 static InternalSymbolizer *get(LowLevelAllocator *alloc) {
330 if (__sanitizer_symbolize_code != 0 &&
331 __sanitizer_symbolize_data != 0) {
332 return new(*alloc) InternalSymbolizer();
337 bool SymbolizePC(uptr addr, SymbolizedStack *stack) override {
338 bool result = __sanitizer_symbolize_code(
339 stack->info.module, stack->info.module_offset, buffer_, kBufferSize);
340 if (result) ParseSymbolizePCOutput(buffer_, stack);
344 bool SymbolizeData(uptr addr, DataInfo *info) override {
345 bool result = __sanitizer_symbolize_data(info->module, info->module_offset,
346 buffer_, kBufferSize);
348 ParseSymbolizeDataOutput(buffer_, info);
349 info->start += (addr - info->module_offset); // Add the base address.
354 void Flush() override {
355 if (__sanitizer_symbolize_flush)
356 __sanitizer_symbolize_flush();
359 const char *Demangle(const char *name) override {
360 if (__sanitizer_symbolize_demangle) {
361 for (uptr res_length = 1024;
362 res_length <= InternalSizeClassMap::kMaxSize;) {
363 char *res_buff = static_cast<char*>(InternalAlloc(res_length));
365 __sanitizer_symbolize_demangle(name, res_buff, res_length);
366 if (req_length > res_length) {
367 res_length = req_length + 1;
368 InternalFree(res_buff);
378 InternalSymbolizer() { }
380 static const int kBufferSize = 16 * 1024;
381 char buffer_[kBufferSize];
383 #else // SANITIZER_SUPPORTS_WEAK_HOOKS
385 class InternalSymbolizer : public SymbolizerTool {
387 static InternalSymbolizer *get(LowLevelAllocator *alloc) { return 0; }
390 #endif // SANITIZER_SUPPORTS_WEAK_HOOKS
392 const char *Symbolizer::PlatformDemangle(const char *name) {
393 return DemangleSwiftAndCXX(name);
396 static SymbolizerTool *ChooseExternalSymbolizer(LowLevelAllocator *allocator) {
397 const char *path = common_flags()->external_symbolizer_path;
398 const char *binary_name = path ? StripModuleName(path) : "";
399 if (path && path[0] == '\0') {
400 VReport(2, "External symbolizer is explicitly disabled.\n");
402 } else if (!internal_strcmp(binary_name, "llvm-symbolizer")) {
403 VReport(2, "Using llvm-symbolizer at user-specified path: %s\n", path);
404 return new(*allocator) LLVMSymbolizer(path, allocator);
405 } else if (!internal_strcmp(binary_name, "atos")) {
407 VReport(2, "Using atos at user-specified path: %s\n", path);
408 return new(*allocator) AtosSymbolizer(path, allocator);
409 #else // SANITIZER_MAC
410 Report("ERROR: Using `atos` is only supported on Darwin.\n");
412 #endif // SANITIZER_MAC
413 } else if (!internal_strcmp(binary_name, "addr2line")) {
414 VReport(2, "Using addr2line at user-specified path: %s\n", path);
415 return new(*allocator) Addr2LinePool(path, allocator);
417 Report("ERROR: External symbolizer path is set to '%s' which isn't "
418 "a known symbolizer. Please set the path to the llvm-symbolizer "
419 "binary or other known tool.\n", path);
423 // Otherwise symbolizer program is unknown, let's search $PATH
424 CHECK(path == nullptr);
426 if (const char *found_path = FindPathToBinary("atos")) {
427 VReport(2, "Using atos found at: %s\n", found_path);
428 return new(*allocator) AtosSymbolizer(found_path, allocator);
430 #endif // SANITIZER_MAC
431 if (const char *found_path = FindPathToBinary("llvm-symbolizer")) {
432 VReport(2, "Using llvm-symbolizer found at: %s\n", found_path);
433 return new(*allocator) LLVMSymbolizer(found_path, allocator);
435 if (common_flags()->allow_addr2line) {
436 if (const char *found_path = FindPathToBinary("addr2line")) {
437 VReport(2, "Using addr2line found at: %s\n", found_path);
438 return new(*allocator) Addr2LinePool(found_path, allocator);
444 static void ChooseSymbolizerTools(IntrusiveList<SymbolizerTool> *list,
445 LowLevelAllocator *allocator) {
446 if (!common_flags()->symbolize) {
447 VReport(2, "Symbolizer is disabled.\n");
450 if (IsAllocatorOutOfMemory()) {
451 VReport(2, "Cannot use internal symbolizer: out of memory\n");
452 } else if (SymbolizerTool *tool = InternalSymbolizer::get(allocator)) {
453 VReport(2, "Using internal symbolizer.\n");
454 list->push_back(tool);
457 if (SymbolizerTool *tool = LibbacktraceSymbolizer::get(allocator)) {
458 VReport(2, "Using libbacktrace symbolizer.\n");
459 list->push_back(tool);
463 if (SymbolizerTool *tool = ChooseExternalSymbolizer(allocator)) {
464 list->push_back(tool);
468 VReport(2, "Using dladdr symbolizer.\n");
469 list->push_back(new(*allocator) DlAddrSymbolizer());
470 #endif // SANITIZER_MAC
473 Symbolizer *Symbolizer::PlatformInit() {
474 IntrusiveList<SymbolizerTool> list;
476 ChooseSymbolizerTools(&list, &symbolizer_allocator_);
477 return new(symbolizer_allocator_) Symbolizer(list);
480 void Symbolizer::LateInitialize() {
481 Symbolizer::GetOrInit();
482 InitializeSwiftDemangler();
485 } // namespace __sanitizer
487 #endif // SANITIZER_POSIX