1 files changed, 487 insertions, 0 deletions
diff --git a/lib/sanitizer_common/sanitizer_symbolizer_posix_libcdep.cpp b/lib/sanitizer_common/sanitizer_symbolizer_posix_libcdep.cpp
new file mode 100644
index 000000000000..c123ecb11206
--- /dev/null
+++ b/lib/sanitizer_common/sanitizer_symbolizer_posix_libcdep.cpp
@@ -0,0 +1,487 @@
+//===-- sanitizer_symbolizer_posix_libcdep.cpp ----------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file is shared between AddressSanitizer and ThreadSanitizer
+// run-time libraries.
+// POSIX-specific implementation of symbolizer parts.
+//===----------------------------------------------------------------------===//
+
+#include "sanitizer_platform.h"
+#if SANITIZER_POSIX
+#include "sanitizer_allocator_internal.h"
+#include "sanitizer_common.h"
+#include "sanitizer_file.h"
+#include "sanitizer_flags.h"
+#include "sanitizer_internal_defs.h"
+#include "sanitizer_linux.h"
+#include "sanitizer_placement_new.h"
+#include "sanitizer_posix.h"
+#include "sanitizer_procmaps.h"
+#include "sanitizer_symbolizer_internal.h"
+#include "sanitizer_symbolizer_libbacktrace.h"
+#include "sanitizer_symbolizer_mac.h"
+
+#include <dlfcn.h>   // for dlsym()
+#include <errno.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <sys/wait.h>
+#include <unistd.h>
+
+// C++ demangling function, as required by Itanium C++ ABI. This is weak,
+// because we do not require a C++ ABI library to be linked to a program
+// using sanitizers; if it's not present, we'll just use the mangled name.
+namespace __cxxabiv1 {
+  extern "C" SANITIZER_WEAK_ATTRIBUTE
+  char *__cxa_demangle(const char *mangled, char *buffer,
+                                  size_t *length, int *status);
+}
+
+namespace __sanitizer {
+
+// Attempts to demangle the name via __cxa_demangle from __cxxabiv1.
+const char *DemangleCXXABI(const char *name) {
+  // FIXME: __cxa_demangle aggressively insists on allocating memory.
+  // There's not much we can do about that, short of providing our
+  // own demangler (libc++abi's implementation could be adapted so that
+  // it does not allocate). For now, we just call it anyway, and we leak
+  // the returned value.
+  if (&__cxxabiv1::__cxa_demangle)
+    if (const char *demangled_name =
+          __cxxabiv1::__cxa_demangle(name, 0, 0, 0))
+      return demangled_name;
+
+  return name;
+}
+
+// As of now, there are no headers for the Swift runtime. Once they are
+// present, we will weakly link since we do not require Swift runtime to be
+// linked.
+typedef char *(*swift_demangle_ft)(const char *mangledName,
+                                   size_t mangledNameLength, char *outputBuffer,
+                                   size_t *outputBufferSize, uint32_t flags);
+static swift_demangle_ft swift_demangle_f;
+
+// This must not happen lazily at symbolication time, because dlsym uses
+// malloc and thread-local storage, which is not a good thing to do during
+// symbolication.
+static void InitializeSwiftDemangler() {
+  swift_demangle_f = (swift_demangle_ft)dlsym(RTLD_DEFAULT, "swift_demangle");
+  (void)dlerror(); // Cleanup error message in case of failure
+}
+
+// Attempts to demangle a Swift name. The demangler will return nullptr if a
+// non-Swift name is passed in.
+const char *DemangleSwift(const char *name) {
+  if (!name) return nullptr;
+
+  // Check if we are dealing with a Swift mangled name first.
+  if (name[0] != '_' || name[1] != 'T') {
+    return nullptr;
+  }
+
+  if (swift_demangle_f)
+    return swift_demangle_f(name, internal_strlen(name), 0, 0, 0);
+
+  return nullptr;
+}
+
+const char *DemangleSwiftAndCXX(const char *name) {
+  if (!name) return nullptr;
+  if (const char *swift_demangled_name = DemangleSwift(name))
+    return swift_demangled_name;
+  return DemangleCXXABI(name);
+}
+
+static bool CreateTwoHighNumberedPipes(int *infd_, int *outfd_) {
+  int *infd = NULL;
+  int *outfd = NULL;
+  // The client program may close its stdin and/or stdout and/or stderr
+  // thus allowing socketpair to reuse file descriptors 0, 1 or 2.
+  // In this case the communication between the forked processes may be
+  // broken if either the parent or the child tries to close or duplicate
+  // these descriptors. The loop below produces two pairs of file
+  // descriptors, each greater than 2 (stderr).
+  int sock_pair[5][2];
+  for (int i = 0; i < 5; i++) {
+    if (pipe(sock_pair[i]) == -1) {
+      for (int j = 0; j < i; j++) {
+        internal_close(sock_pair[j][0]);
+        internal_close(sock_pair[j][1]);
+      }
+      return false;
+    } else if (sock_pair[i][0] > 2 && sock_pair[i][1] > 2) {
+      if (infd == NULL) {
+        infd = sock_pair[i];
+      } else {
+        outfd = sock_pair[i];
+        for (int j = 0; j < i; j++) {
+          if (sock_pair[j] == infd) continue;
+          internal_close(sock_pair[j][0]);
+          internal_close(sock_pair[j][1]);
+        }
+        break;
+      }
+    }
+  }
+  CHECK(infd);
+  CHECK(outfd);
+  infd_[0] = infd[0];
+  infd_[1] = infd[1];
+  outfd_[0] = outfd[0];
+  outfd_[1] = outfd[1];
+  return true;
+}
+
+bool SymbolizerProcess::StartSymbolizerSubprocess() {
+  if (!FileExists(path_)) {
+    if (!reported_invalid_path_) {
+      Report("WARNING: invalid path to external symbolizer!\n");
+      reported_invalid_path_ = true;
+    }
+    return false;
+  }
+
+  const char *argv[kArgVMax];
+  GetArgV(path_, argv);
+  pid_t pid;
+
+  if (use_posix_spawn_) {
+#if SANITIZER_MAC
+    fd_t fd = internal_spawn(argv, &pid);
+    if (fd == kInvalidFd) {
+      Report("WARNING: failed to spawn external symbolizer (errno: %d)\n",
+             errno);
+      return false;
+    }
+
+    input_fd_ = fd;
+    output_fd_ = fd;
+#else  // SANITIZER_MAC
+    UNIMPLEMENTED();
+#endif  // SANITIZER_MAC
+  } else {
+    fd_t infd[2] = {}, outfd[2] = {};
+    if (!CreateTwoHighNumberedPipes(infd, outfd)) {
+      Report("WARNING: Can't create a socket pair to start "
+             "external symbolizer (errno: %d)\n", errno);
+      return false;
+    }
+
+    pid = StartSubprocess(path_, argv, /* stdin */ outfd[0],
+                          /* stdout */ infd[1]);
+    if (pid < 0) {
+      internal_close(infd[0]);
+      internal_close(outfd[1]);
+      return false;
+    }
+
+    input_fd_ = infd[0];
+    output_fd_ = outfd[1];
+  }
+
+  CHECK_GT(pid, 0);
+
+  // Check that symbolizer subprocess started successfully.
+  SleepForMillis(kSymbolizerStartupTimeMillis);
+  if (!IsProcessRunning(pid)) {
+    // Either waitpid failed, or child has already exited.
+    Report("WARNING: external symbolizer didn't start up correctly!\n");
+    return false;
+  }
+
+  return true;
+}
+
+class Addr2LineProcess : public SymbolizerProcess {
+ public:
+  Addr2LineProcess(const char *path, const char *module_name)
+      : SymbolizerProcess(path), module_name_(internal_strdup(module_name)) {}
+
+  const char *module_name() const { return module_name_; }
+
+ private:
+  void GetArgV(const char *path_to_binary,
+               const char *(&argv)[kArgVMax]) const override {
+    int i = 0;
+    argv[i++] = path_to_binary;
+    argv[i++] = "-iCfe";
+    argv[i++] = module_name_;
+    argv[i++] = nullptr;
+  }
+
+  bool ReachedEndOfOutput(const char *buffer, uptr length) const override;
+
+  bool ReadFromSymbolizer(char *buffer, uptr max_length) override {
+    if (!SymbolizerProcess::ReadFromSymbolizer(buffer, max_length))
+      return false;
+    // The returned buffer is empty when output is valid, but exceeds
+    // max_length.
+    if (*buffer == '\0')
+      return true;
+    // We should cut out output_terminator_ at the end of given buffer,
+    // appended by addr2line to mark the end of its meaningful output.
+    // We cannot scan buffer from it's beginning, because it is legal for it
+    // to start with output_terminator_ in case given offset is invalid. So,
+    // scanning from second character.
+    char *garbage = internal_strstr(buffer + 1, output_terminator_);
+    // This should never be NULL since buffer must end up with
+    // output_terminator_.
+    CHECK(garbage);
+    // Trim the buffer.
+    garbage[0] = '\0';
+    return true;
+  }
+
+  const char *module_name_;  // Owned, leaked.
+  static const char output_terminator_[];
+};
+
+const char Addr2LineProcess::output_terminator_[] = "??\n??:0\n";
+
+bool Addr2LineProcess::ReachedEndOfOutput(const char *buffer,
+                                          uptr length) const {
+  const size_t kTerminatorLen = sizeof(output_terminator_) - 1;
+  // Skip, if we read just kTerminatorLen bytes, because Addr2Line output
+  // should consist at least of two pairs of lines:
+  // 1. First one, corresponding to given offset to be symbolized
+  // (may be equal to output_terminator_, if offset is not valid).
+  // 2. Second one for output_terminator_, itself to mark the end of output.
+  if (length <= kTerminatorLen) return false;
+  // Addr2Line output should end up with output_terminator_.
+  return !internal_memcmp(buffer + length - kTerminatorLen,
+                          output_terminator_, kTerminatorLen);
+}
+
+class Addr2LinePool : public SymbolizerTool {
+ public:
+  explicit Addr2LinePool(const char *addr2line_path,
+                         LowLevelAllocator *allocator)
+      : addr2line_path_(addr2line_path), allocator_(allocator) {
+    addr2line_pool_.reserve(16);
+  }
+
+  bool SymbolizePC(uptr addr, SymbolizedStack *stack) override {
+    if (const char *buf =
+            SendCommand(stack->info.module, stack->info.module_offset)) {
+      ParseSymbolizePCOutput(buf, stack);
+      return true;
+    }
+    return false;
+  }
+
+  bool SymbolizeData(uptr addr, DataInfo *info) override {
+    return false;
+  }
+
+ private:
+  const char *SendCommand(const char *module_name, uptr module_offset) {
+    Addr2LineProcess *addr2line = 0;
+    for (uptr i = 0; i < addr2line_pool_.size(); ++i) {
+      if (0 ==
+          internal_strcmp(module_name, addr2line_pool_[i]->module_name())) {
+        addr2line = addr2line_pool_[i];
+        break;
+      }
+    }
+    if (!addr2line) {
+      addr2line =
+          new(*allocator_) Addr2LineProcess(addr2line_path_, module_name);
+      addr2line_pool_.push_back(addr2line);
+    }
+    CHECK_EQ(0, internal_strcmp(module_name, addr2line->module_name()));
+    char buffer[kBufferSize];
+    internal_snprintf(buffer, kBufferSize, "0x%zx\n0x%zx\n",
+                      module_offset, dummy_address_);
+    return addr2line->SendCommand(buffer);
+  }
+
+  static const uptr kBufferSize = 64;
+  const char *addr2line_path_;
+  LowLevelAllocator *allocator_;
+  InternalMmapVector<Addr2LineProcess*> addr2line_pool_;
+  static const uptr dummy_address_ =
+      FIRST_32_SECOND_64(UINT32_MAX, UINT64_MAX);
+};
+
+#if SANITIZER_SUPPORTS_WEAK_HOOKS
+extern "C" {
+SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
+bool __sanitizer_symbolize_code(const char *ModuleName, u64 ModuleOffset,
+                                char *Buffer, int MaxLength);
+SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
+bool __sanitizer_symbolize_data(const char *ModuleName, u64 ModuleOffset,
+                                char *Buffer, int MaxLength);
+SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
+void __sanitizer_symbolize_flush();
+SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
+int __sanitizer_symbolize_demangle(const char *Name, char *Buffer,
+                                   int MaxLength);
+}  // extern "C"
+
+class InternalSymbolizer : public SymbolizerTool {
+ public:
+  static InternalSymbolizer *get(LowLevelAllocator *alloc) {
+    if (__sanitizer_symbolize_code != 0 &&
+        __sanitizer_symbolize_data != 0) {
+      return new(*alloc) InternalSymbolizer();
+    }
+    return 0;
+  }
+
+  bool SymbolizePC(uptr addr, SymbolizedStack *stack) override {
+    bool result = __sanitizer_symbolize_code(
+        stack->info.module, stack->info.module_offset, buffer_, kBufferSize);
+    if (result) ParseSymbolizePCOutput(buffer_, stack);
+    return result;
+  }
+
+  bool SymbolizeData(uptr addr, DataInfo *info) override {
+    bool result = __sanitizer_symbolize_data(info->module, info->module_offset,
+                                             buffer_, kBufferSize);
+    if (result) {
+      ParseSymbolizeDataOutput(buffer_, info);
+      info->start += (addr - info->module_offset);  // Add the base address.
+    }
+    return result;
+  }
+
+  void Flush() override {
+    if (__sanitizer_symbolize_flush)
+      __sanitizer_symbolize_flush();
+  }
+
+  const char *Demangle(const char *name) override {
+    if (__sanitizer_symbolize_demangle) {
+      for (uptr res_length = 1024;
+           res_length <= InternalSizeClassMap::kMaxSize;) {
+        char *res_buff = static_cast<char*>(InternalAlloc(res_length));
+        uptr req_length =
+            __sanitizer_symbolize_demangle(name, res_buff, res_length);
+        if (req_length > res_length) {
+          res_length = req_length + 1;
+          InternalFree(res_buff);
+          continue;
+        }
+        return res_buff;
+      }
+    }
+    return name;
+  }
+
+ private:
+  InternalSymbolizer() { }
+
+  static const int kBufferSize = 16 * 1024;
+  char buffer_[kBufferSize];
+};
+#else  // SANITIZER_SUPPORTS_WEAK_HOOKS
+
+class InternalSymbolizer : public SymbolizerTool {
+ public:
+  static InternalSymbolizer *get(LowLevelAllocator *alloc) { return 0; }
+};
+
+#endif  // SANITIZER_SUPPORTS_WEAK_HOOKS
+
+const char *Symbolizer::PlatformDemangle(const char *name) {
+  return DemangleSwiftAndCXX(name);
+}
+
+static SymbolizerTool *ChooseExternalSymbolizer(LowLevelAllocator *allocator) {
+  const char *path = common_flags()->external_symbolizer_path;
+  const char *binary_name = path ? StripModuleName(path) : "";
+  if (path && path[0] == '\0') {
+    VReport(2, "External symbolizer is explicitly disabled.\n");
+    return nullptr;
+  } else if (!internal_strcmp(binary_name, "llvm-symbolizer")) {
+    VReport(2, "Using llvm-symbolizer at user-specified path: %s\n", path);
+    return new(*allocator) LLVMSymbolizer(path, allocator);
+  } else if (!internal_strcmp(binary_name, "atos")) {
+#if SANITIZER_MAC
+    VReport(2, "Using atos at user-specified path: %s\n", path);
+    return new(*allocator) AtosSymbolizer(path, allocator);
+#else  // SANITIZER_MAC
+    Report("ERROR: Using `atos` is only supported on Darwin.\n");
+    Die();
+#endif  // SANITIZER_MAC
+  } else if (!internal_strcmp(binary_name, "addr2line")) {
+    VReport(2, "Using addr2line at user-specified path: %s\n", path);
+    return new(*allocator) Addr2LinePool(path, allocator);
+  } else if (path) {
+    Report("ERROR: External symbolizer path is set to '%s' which isn't "
+           "a known symbolizer. Please set the path to the llvm-symbolizer "
+           "binary or other known tool.\n", path);
+    Die();
+  }
+
+  // Otherwise symbolizer program is unknown, let's search $PATH
+  CHECK(path == nullptr);
+#if SANITIZER_MAC
+  if (const char *found_path = FindPathToBinary("atos")) {
+    VReport(2, "Using atos found at: %s\n", found_path);
+    return new(*allocator) AtosSymbolizer(found_path, allocator);
+  }
+#endif  // SANITIZER_MAC
+  if (const char *found_path = FindPathToBinary("llvm-symbolizer")) {
+    VReport(2, "Using llvm-symbolizer found at: %s\n", found_path);
+    return new(*allocator) LLVMSymbolizer(found_path, allocator);
+  }
+  if (common_flags()->allow_addr2line) {
+    if (const char *found_path = FindPathToBinary("addr2line")) {
+      VReport(2, "Using addr2line found at: %s\n", found_path);
+      return new(*allocator) Addr2LinePool(found_path, allocator);
+    }
+  }
+  return nullptr;
+}
+
+static void ChooseSymbolizerTools(IntrusiveList<SymbolizerTool> *list,
+                                  LowLevelAllocator *allocator) {
+  if (!common_flags()->symbolize) {
+    VReport(2, "Symbolizer is disabled.\n");
+    return;
+  }
+  if (IsAllocatorOutOfMemory()) {
+    VReport(2, "Cannot use internal symbolizer: out of memory\n");
+  } else if (SymbolizerTool *tool = InternalSymbolizer::get(allocator)) {
+    VReport(2, "Using internal symbolizer.\n");
+    list->push_back(tool);
+    return;
+  }
+  if (SymbolizerTool *tool = LibbacktraceSymbolizer::get(allocator)) {
+    VReport(2, "Using libbacktrace symbolizer.\n");
+    list->push_back(tool);
+    return;
+  }
+
+  if (SymbolizerTool *tool = ChooseExternalSymbolizer(allocator)) {
+    list->push_back(tool);
+  }
+
+#if SANITIZER_MAC
+  VReport(2, "Using dladdr symbolizer.\n");
+  list->push_back(new(*allocator) DlAddrSymbolizer());
+#endif  // SANITIZER_MAC
+}
+
+Symbolizer *Symbolizer::PlatformInit() {
+  IntrusiveList<SymbolizerTool> list;
+  list.clear();
+  ChooseSymbolizerTools(&list, &symbolizer_allocator_);
+  return new(symbolizer_allocator_) Symbolizer(list);
+}
+
+void Symbolizer::LateInitialize() {
+  Symbolizer::GetOrInit();
+  InitializeSwiftDemangler();
+}
+
+}  // namespace __sanitizer
+
+#endif  // SANITIZER_POSIX