1 //===-- sanitizer_symbolizer_posix_libcdep.cc -----------------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file is shared between AddressSanitizer and ThreadSanitizer
11 // run-time libraries.
12 // POSIX-specific implementation of symbolizer parts.
13 //===----------------------------------------------------------------------===//
15 #include "sanitizer_platform.h"
17 #include "sanitizer_allocator_internal.h"
18 #include "sanitizer_common.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()
37 #include <util.h> // for forkpty()
38 #endif // SANITIZER_MAC
40 // C++ demangling function, as required by Itanium C++ ABI. This is weak,
41 // because we do not require a C++ ABI library to be linked to a program
42 // using sanitizers; if it's not present, we'll just use the mangled name.
43 namespace __cxxabiv1 {
44 extern "C" SANITIZER_WEAK_ATTRIBUTE
45 char *__cxa_demangle(const char *mangled, char *buffer,
46 size_t *length, int *status);
49 namespace __sanitizer {
51 // Attempts to demangle the name via __cxa_demangle from __cxxabiv1.
52 const char *DemangleCXXABI(const char *name) {
53 // FIXME: __cxa_demangle aggressively insists on allocating memory.
54 // There's not much we can do about that, short of providing our
55 // own demangler (libc++abi's implementation could be adapted so that
56 // it does not allocate). For now, we just call it anyway, and we leak
57 // the returned value.
58 if (__cxxabiv1::__cxa_demangle)
59 if (const char *demangled_name =
60 __cxxabiv1::__cxa_demangle(name, 0, 0, 0))
61 return demangled_name;
66 // As of now, there are no headers for the Swift runtime. Once they are
67 // present, we will weakly link since we do not require Swift runtime to be
69 typedef char *(*swift_demangle_ft)(const char *mangledName,
70 size_t mangledNameLength, char *outputBuffer,
71 size_t *outputBufferSize, uint32_t flags);
72 static swift_demangle_ft swift_demangle_f;
74 // This must not happen lazily at symbolication time, because dlsym uses
75 // malloc and thread-local storage, which is not a good thing to do during
77 static void InitializeSwiftDemangler() {
78 swift_demangle_f = (swift_demangle_ft)dlsym(RTLD_DEFAULT, "swift_demangle");
81 // Attempts to demangle a Swift name. The demangler will return nullptr if a
82 // non-Swift name is passed in.
83 const char *DemangleSwift(const char *name) {
84 if (!name) return nullptr;
86 // Check if we are dealing with a Swift mangled name first.
87 if (name[0] != '_' || name[1] != 'T') {
92 return swift_demangle_f(name, internal_strlen(name), 0, 0, 0);
97 const char *DemangleSwiftAndCXX(const char *name) {
98 if (!name) return nullptr;
99 if (const char *swift_demangled_name = DemangleSwift(name))
100 return swift_demangled_name;
101 return DemangleCXXABI(name);
104 bool SymbolizerProcess::StartSymbolizerSubprocess() {
105 if (!FileExists(path_)) {
106 if (!reported_invalid_path_) {
107 Report("WARNING: invalid path to external symbolizer!\n");
108 reported_invalid_path_ = true;
116 fd_t fd = kInvalidFd;
118 // forkpty redirects stdout and stderr into a single stream, so we would
119 // receive error messages as standard replies. To avoid that, let's dup
120 // stderr and restore it in the child.
121 int saved_stderr = dup(STDERR_FILENO);
122 CHECK_GE(saved_stderr, 0);
124 // Use forkpty to disable buffering in the new terminal.
125 pid = internal_forkpty(&fd);
128 Report("WARNING: failed to fork external symbolizer (errno: %d)\n",
131 } else if (pid == 0) {
135 CHECK_GE(dup2(saved_stderr, STDERR_FILENO), 0);
138 const char *argv[kArgVMax];
139 GetArgV(path_, argv);
140 execv(path_, const_cast<char **>(&argv[0]));
144 // Continue execution in parent process.
145 input_fd_ = output_fd_ = fd;
149 // Disable echo in the new terminal, disable CR.
150 struct termios termflags;
151 tcgetattr(fd, &termflags);
152 termflags.c_oflag &= ~ONLCR;
153 termflags.c_lflag &= ~ECHO;
154 tcsetattr(fd, TCSANOW, &termflags);
155 #else // SANITIZER_MAC
157 #endif // SANITIZER_MAC
161 // The client program may close its stdin and/or stdout and/or stderr
162 // thus allowing socketpair to reuse file descriptors 0, 1 or 2.
163 // In this case the communication between the forked processes may be
164 // broken if either the parent or the child tries to close or duplicate
165 // these descriptors. The loop below produces two pairs of file
166 // descriptors, each greater than 2 (stderr).
168 for (int i = 0; i < 5; i++) {
169 if (pipe(sock_pair[i]) == -1) {
170 for (int j = 0; j < i; j++) {
171 internal_close(sock_pair[j][0]);
172 internal_close(sock_pair[j][1]);
174 Report("WARNING: Can't create a socket pair to start "
175 "external symbolizer (errno: %d)\n", errno);
177 } else if (sock_pair[i][0] > 2 && sock_pair[i][1] > 2) {
181 outfd = sock_pair[i];
182 for (int j = 0; j < i; j++) {
183 if (sock_pair[j] == infd) continue;
184 internal_close(sock_pair[j][0]);
185 internal_close(sock_pair[j][1]);
194 const char *argv[kArgVMax];
195 GetArgV(path_, argv);
196 pid = StartSubprocess(path_, argv, /* stdin */ outfd[0],
197 /* stdout */ infd[1]);
199 internal_close(infd[0]);
200 internal_close(outfd[1]);
205 output_fd_ = outfd[1];
208 // Check that symbolizer subprocess started successfully.
209 SleepForMillis(kSymbolizerStartupTimeMillis);
210 if (!IsProcessRunning(pid)) {
211 // Either waitpid failed, or child has already exited.
212 Report("WARNING: external symbolizer didn't start up correctly!\n");
219 class Addr2LineProcess : public SymbolizerProcess {
221 Addr2LineProcess(const char *path, const char *module_name)
222 : SymbolizerProcess(path), module_name_(internal_strdup(module_name)) {}
224 const char *module_name() const { return module_name_; }
227 void GetArgV(const char *path_to_binary,
228 const char *(&argv)[kArgVMax]) const override {
230 argv[i++] = path_to_binary;
232 argv[i++] = module_name_;
236 bool ReachedEndOfOutput(const char *buffer, uptr length) const override;
238 bool ReadFromSymbolizer(char *buffer, uptr max_length) override {
239 if (!SymbolizerProcess::ReadFromSymbolizer(buffer, max_length))
241 // We should cut out output_terminator_ at the end of given buffer,
242 // appended by addr2line to mark the end of its meaningful output.
243 // We cannot scan buffer from it's beginning, because it is legal for it
244 // to start with output_terminator_ in case given offset is invalid. So,
245 // scanning from second character.
246 char *garbage = internal_strstr(buffer + 1, output_terminator_);
247 // This should never be NULL since buffer must end up with
248 // output_terminator_.
255 const char *module_name_; // Owned, leaked.
256 static const char output_terminator_[];
259 const char Addr2LineProcess::output_terminator_[] = "??\n??:0\n";
261 bool Addr2LineProcess::ReachedEndOfOutput(const char *buffer,
263 const size_t kTerminatorLen = sizeof(output_terminator_) - 1;
264 // Skip, if we read just kTerminatorLen bytes, because Addr2Line output
265 // should consist at least of two pairs of lines:
266 // 1. First one, corresponding to given offset to be symbolized
267 // (may be equal to output_terminator_, if offset is not valid).
268 // 2. Second one for output_terminator_, itself to mark the end of output.
269 if (length <= kTerminatorLen) return false;
270 // Addr2Line output should end up with output_terminator_.
271 return !internal_memcmp(buffer + length - kTerminatorLen,
272 output_terminator_, kTerminatorLen);
275 class Addr2LinePool : public SymbolizerTool {
277 explicit Addr2LinePool(const char *addr2line_path,
278 LowLevelAllocator *allocator)
279 : addr2line_path_(addr2line_path), allocator_(allocator),
280 addr2line_pool_(16) {}
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);
291 bool SymbolizeData(uptr addr, DataInfo *info) override {
296 const char *SendCommand(const char *module_name, uptr module_offset) {
297 Addr2LineProcess *addr2line = 0;
298 for (uptr i = 0; i < addr2line_pool_.size(); ++i) {
300 internal_strcmp(module_name, addr2line_pool_[i]->module_name())) {
301 addr2line = addr2line_pool_[i];
307 new(*allocator_) Addr2LineProcess(addr2line_path_, module_name);
308 addr2line_pool_.push_back(addr2line);
310 CHECK_EQ(0, internal_strcmp(module_name, addr2line->module_name()));
311 char buffer[kBufferSize];
312 internal_snprintf(buffer, kBufferSize, "0x%zx\n0x%zx\n",
313 module_offset, dummy_address_);
314 return addr2line->SendCommand(buffer);
317 static const uptr kBufferSize = 64;
318 const char *addr2line_path_;
319 LowLevelAllocator *allocator_;
320 InternalMmapVector<Addr2LineProcess*> addr2line_pool_;
321 static const uptr dummy_address_ =
322 FIRST_32_SECOND_64(UINT32_MAX, UINT64_MAX);
325 #if SANITIZER_SUPPORTS_WEAK_HOOKS
327 SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
328 bool __sanitizer_symbolize_code(const char *ModuleName, u64 ModuleOffset,
329 char *Buffer, int MaxLength);
330 SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
331 bool __sanitizer_symbolize_data(const char *ModuleName, u64 ModuleOffset,
332 char *Buffer, int MaxLength);
333 SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
334 void __sanitizer_symbolize_flush();
335 SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
336 int __sanitizer_symbolize_demangle(const char *Name, char *Buffer,
340 class InternalSymbolizer : public SymbolizerTool {
342 static InternalSymbolizer *get(LowLevelAllocator *alloc) {
343 if (__sanitizer_symbolize_code != 0 &&
344 __sanitizer_symbolize_data != 0) {
345 return new(*alloc) InternalSymbolizer();
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) ParseSymbolizePCOutput(buffer_, stack);
357 bool SymbolizeData(uptr addr, DataInfo *info) override {
358 bool result = __sanitizer_symbolize_data(info->module, info->module_offset,
359 buffer_, kBufferSize);
361 ParseSymbolizeDataOutput(buffer_, info);
362 info->start += (addr - info->module_offset); // Add the base address.
367 void Flush() override {
368 if (__sanitizer_symbolize_flush)
369 __sanitizer_symbolize_flush();
372 const char *Demangle(const char *name) override {
373 if (__sanitizer_symbolize_demangle) {
374 for (uptr res_length = 1024;
375 res_length <= InternalSizeClassMap::kMaxSize;) {
376 char *res_buff = static_cast<char*>(InternalAlloc(res_length));
378 __sanitizer_symbolize_demangle(name, res_buff, res_length);
379 if (req_length > res_length) {
380 res_length = req_length + 1;
381 InternalFree(res_buff);
391 InternalSymbolizer() { }
393 static const int kBufferSize = 16 * 1024;
394 static const int kMaxDemangledNameSize = 1024;
395 char buffer_[kBufferSize];
397 #else // SANITIZER_SUPPORTS_WEAK_HOOKS
399 class InternalSymbolizer : public SymbolizerTool {
401 static InternalSymbolizer *get(LowLevelAllocator *alloc) { return 0; }
404 #endif // SANITIZER_SUPPORTS_WEAK_HOOKS
406 const char *Symbolizer::PlatformDemangle(const char *name) {
407 return DemangleSwiftAndCXX(name);
410 void Symbolizer::PlatformPrepareForSandboxing() {}
412 static SymbolizerTool *ChooseExternalSymbolizer(LowLevelAllocator *allocator) {
413 const char *path = common_flags()->external_symbolizer_path;
414 const char *binary_name = path ? StripModuleName(path) : "";
415 if (path && path[0] == '\0') {
416 VReport(2, "External symbolizer is explicitly disabled.\n");
418 } else if (!internal_strcmp(binary_name, "llvm-symbolizer")) {
419 VReport(2, "Using llvm-symbolizer at user-specified path: %s\n", path);
420 return new(*allocator) LLVMSymbolizer(path, allocator);
421 } else if (!internal_strcmp(binary_name, "atos")) {
423 VReport(2, "Using atos at user-specified path: %s\n", path);
424 return new(*allocator) AtosSymbolizer(path, allocator);
425 #else // SANITIZER_MAC
426 Report("ERROR: Using `atos` is only supported on Darwin.\n");
428 #endif // SANITIZER_MAC
429 } else if (!internal_strcmp(binary_name, "addr2line")) {
430 VReport(2, "Using addr2line at user-specified path: %s\n", path);
431 return new(*allocator) Addr2LinePool(path, allocator);
433 Report("ERROR: External symbolizer path is set to '%s' which isn't "
434 "a known symbolizer. Please set the path to the llvm-symbolizer "
435 "binary or other known tool.\n", path);
439 // Otherwise symbolizer program is unknown, let's search $PATH
440 CHECK(path == nullptr);
441 if (const char *found_path = FindPathToBinary("llvm-symbolizer")) {
442 VReport(2, "Using llvm-symbolizer found at: %s\n", found_path);
443 return new(*allocator) LLVMSymbolizer(found_path, allocator);
446 if (const char *found_path = FindPathToBinary("atos")) {
447 VReport(2, "Using atos found at: %s\n", found_path);
448 return new(*allocator) AtosSymbolizer(found_path, allocator);
450 #endif // SANITIZER_MAC
451 if (common_flags()->allow_addr2line) {
452 if (const char *found_path = FindPathToBinary("addr2line")) {
453 VReport(2, "Using addr2line found at: %s\n", found_path);
454 return new(*allocator) Addr2LinePool(found_path, allocator);
460 static void ChooseSymbolizerTools(IntrusiveList<SymbolizerTool> *list,
461 LowLevelAllocator *allocator) {
462 if (!common_flags()->symbolize) {
463 VReport(2, "Symbolizer is disabled.\n");
466 if (SymbolizerTool *tool = InternalSymbolizer::get(allocator)) {
467 VReport(2, "Using internal symbolizer.\n");
468 list->push_back(tool);
471 if (SymbolizerTool *tool = LibbacktraceSymbolizer::get(allocator)) {
472 VReport(2, "Using libbacktrace symbolizer.\n");
473 list->push_back(tool);
477 if (SymbolizerTool *tool = ChooseExternalSymbolizer(allocator)) {
478 list->push_back(tool);
482 VReport(2, "Using dladdr symbolizer.\n");
483 list->push_back(new(*allocator) DlAddrSymbolizer());
484 #endif // SANITIZER_MAC
487 Symbolizer *Symbolizer::PlatformInit() {
488 IntrusiveList<SymbolizerTool> list;
490 ChooseSymbolizerTools(&list, &symbolizer_allocator_);
491 return new(symbolizer_allocator_) Symbolizer(list);
494 void Symbolizer::LateInitialize() {
495 Symbolizer::GetOrInit();
496 InitializeSwiftDemangler();
499 } // namespace __sanitizer
501 #endif // SANITIZER_POSIX