Add breakpad support to mojo shell apk.

shell/crash/breakpad_linux.cc

+// Copyright 2013 The Chromium Authors. All rights reserved.

[qsr, 2015/07/09 14:58:53]

This code is forked (and heavily simplified) from chromium, I didn't change the
copyright because o this.

[tonyg, 2015/07/09 15:41:03]

Would there be any value in stating the original location in a comment in this
file?

[qsr, 2015/07/27 14:06:53]

Done.

+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// For linux_syscall_support.h. This makes it safe to call embedded system
+// calls when in seccomp mode.
+
+#include "shell/crash/breakpad_linux.h"
+
+#include <fcntl.h>
+#include <poll.h>
+#include <signal.h>
+#include <stdlib.h>
+#include <sys/socket.h>
+#include <sys/time.h>
+#include <sys/types.h>
+#include <sys/uio.h>
+#include <sys/wait.h>
+#include <time.h>
+#include <unistd.h>
+
+#include <algorithm>
+#include <string>
+
+#include "base/base_switches.h"
+#include "base/command_line.h"
+#include "base/debug/crash_logging.h"
+#include "base/debug/dump_without_crashing.h"
+#include "base/files/file_path.h"
+#include "base/linux_util.h"
+#include "base/path_service.h"
+#include "base/posix/eintr_wrapper.h"
+#include "base/process/memory.h"
+#include "base/strings/string_util.h"
+#include "breakpad/src/client/linux/crash_generation/crash_generation_client.h"
+#include "breakpad/src/client/linux/handler/exception_handler.h"
+#include "breakpad/src/client/linux/minidump_writer/directory_reader.h"
+#include "breakpad/src/common/linux/linux_libc_support.h"
+#include "breakpad/src/common/memory.h"
+#include "build/build_config.h"
+#include "shell/crash/breakpad_linux_impl.h"
+
+#if defined(OS_ANDROID)
+#include <android/log.h>
+#include <sys/stat.h>
+
+#include "base/android/build_info.h"
+#include "base/android/path_utils.h"
+#include "base/debug/leak_annotations.h"
+#endif
+#include "third_party/lss/linux_syscall_support.h"
+
+#if defined(OS_ANDROID)
+#define STAT_STRUCT struct stat
+#define FSTAT_FUNC fstat
+#else
+#define STAT_STRUCT struct kernel_stat
+#define FSTAT_FUNC sys_fstat
+#endif
+
+// Some versions of gcc are prone to warn about unused return values. In cases
+// where we either a) know the call cannot fail, or b) there is nothing we
+// can do when a call fails, we mark the return code as ignored. This avoids
+// spurious compiler warnings.
+#define IGNORE_RET(x) \
+  do {                \
+    if (x)            \
+      ;               \
+  } while (0)
+
+using google_breakpad::ExceptionHandler;
+using google_breakpad::MinidumpDescriptor;
+
+namespace breakpad {
+
+namespace {
+
+bool g_is_crash_reporter_enabled = false;
+uint64_t g_process_start_time = 0;
+pid_t g_pid = 0;
+char* g_crash_log_path = nullptr;
+ExceptionHandler* g_breakpad = nullptr;
+
+CrashKeyStorage* g_crash_keys = nullptr;
+
+#if defined(OS_ANDROID)
+const char kProductName[] = "MojoShell.apk";
+#else
+const char kProductName[] = "MojoShell";
+#endif
+const char kVersion[] = "1.0.0";
+
+// Writes the value |v| as 16 hex characters to the memory pointed at by
+// |output|.
+void write_uint64_hex(char* output, uint64_t v) {
+  static const char hextable[] = "0123456789abcdef";
+
+  for (int i = 15; i >= 0; --i) {
+    output[i] = hextable[v & 15];
+    v >>= 4;
+  }
+}
+
+// The following helper functions are for calculating uptime.
+
+// Converts a struct timeval to milliseconds.
+uint64_t timeval_to_ms(struct timeval* tv) {
+  uint64_t ret = tv->tv_sec;  // Avoid overflow by explicitly using a uint64_t.
+  ret *= 1000;
+  ret += tv->tv_usec / 1000;
+  return ret;
+}
+
+// Converts a struct timeval to milliseconds.
+uint64_t kernel_timeval_to_ms(struct kernel_timeval* tv) {
+  uint64_t ret = tv->tv_sec;  // Avoid overflow by explicitly using a uint64_t.
+  ret *= 1000;
+  ret += tv->tv_usec / 1000;
+  return ret;
+}
+
+// String buffer size to use to convert a uint64_t to string.
+const size_t kUint64StringSize = 21;
+
+void SetProcessStartTime() {
+  // Set the base process start time value.
+  struct timeval tv;
+  if (!gettimeofday(&tv, nullptr))
+    g_process_start_time = timeval_to_ms(&tv);
+  else
+    g_process_start_time = 0;
+}
+
+// uint64_t version of my_int_len() from
+// breakpad/src/common/linux/linux_libc_support.h. Return the length of the
+// given, non-negative integer when expressed in base 10.
+unsigned my_uint64_len(uint64_t i) {
+  if (!i)
+    return 1;
+
+  unsigned len = 0;
+  while (i) {
+    len++;
+    i /= 10;
+  }
+
+  return len;
+}
+
+// uint64_t version of my_uitos() from
+// breakpad/src/common/linux/linux_libc_support.h. Convert a non-negative
+// integer to a string (not null-terminated).
+void my_uint64tos(char* output, uint64_t i, unsigned i_len) {
+  for (unsigned index = i_len; index; --index, i /= 10)
+    output[index - 1] = '0' + (i % 10);
+}
+
+bool my_isxdigit(char c) {
+  return (c >= '0' && c <= '9') || ((c | 0x20) >= 'a' && (c | 0x20) <= 'f');
+}
+
+size_t LengthWithoutTrailingSpaces(const char* str, size_t len) {
+  while (len > 0 && str[len - 1] == ' ') {
+    len--;
+  }
+  return len;
+}
+
+// MIME substrings.
+const char g_rn[] = "\r\n";
+const char g_form_data_msg[] = "Content-Disposition: form-data; name=\"";
+const char g_quote_msg[] = "\"";
+const char g_dashdash_msg[] = "--";
+const char g_dump_msg[] = "upload_file_minidump\"; filename=\"dump\"";
+const char g_content_type_msg[] = "Content-Type: application/octet-stream";
+
+// MimeWriter manages an iovec for writing MIMEs to a file.
+class MimeWriter {
+ public:
+  static const int kIovCapacity = 30;
+  static const size_t kMaxCrashChunkSize = 64;
+
+  MimeWriter(int fd, const char* const mime_boundary);
+  ~MimeWriter();
+
+  // Append boundary.
+  virtual void AddBoundary();
+
+  // Append end of file boundary.
+  virtual void AddEnd();
+
+  // Append key/value pair with specified sizes.
+  virtual void AddPairData(const char* msg_type,
+                           size_t msg_type_size,
+                           const char* msg_data,
+                           size_t msg_data_size);
+
+  // Append key/value pair.
+  void AddPairString(const char* msg_type, const char* msg_data) {
+    AddPairData(msg_type, my_strlen(msg_type), msg_data, my_strlen(msg_data));
+  }
+
+  // Append key/value pair, splitting value into chunks no larger than
+  // |chunk_size|. |chunk_size| cannot be greater than |kMaxCrashChunkSize|.
+  // The msg_type string will have a counter suffix to distinguish each chunk.
+  virtual void AddPairDataInChunks(const char* msg_type,
+                                   size_t msg_type_size,
+                                   const char* msg_data,
+                                   size_t msg_data_size,
+                                   size_t chunk_size,
+                                   bool strip_trailing_spaces);
+
+  // Add binary file contents to be uploaded with the specified filename.
+  virtual void AddFileContents(const char* filename_msg,
+                               uint8_t* file_data,
+                               size_t file_size);
+
+  // Flush any pending iovecs to the output file.
+  void Flush() {
+    IGNORE_RET(sys_writev(fd_, iov_, iov_index_));
+    iov_index_ = 0;
+  }
+
+ protected:
+  void AddItem(const void* base, size_t size);
+  // Minor performance trade-off for easier-to-maintain code.
+  void AddString(const char* str) { AddItem(str, my_strlen(str)); }
+  void AddItemWithoutTrailingSpaces(const void* base, size_t size);
+
+  struct kernel_iovec iov_[kIovCapacity];
+  int iov_index_;
+
+  // Output file descriptor.
+  int fd_;
+
+  const char* const mime_boundary_;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(MimeWriter);
+};
+
+MimeWriter::MimeWriter(int fd, const char* const mime_boundary)
+    : iov_index_(0), fd_(fd), mime_boundary_(mime_boundary) {
+}
+
+MimeWriter::~MimeWriter() {
+}
+
+void MimeWriter::AddBoundary() {
+  AddString(mime_boundary_);
+  AddString(g_rn);
+}
+
+void MimeWriter::AddEnd() {
+  AddString(mime_boundary_);
+  AddString(g_dashdash_msg);
+  AddString(g_rn);
+}
+
+void MimeWriter::AddPairData(const char* msg_type,
+                             size_t msg_type_size,
+                             const char* msg_data,
+                             size_t msg_data_size) {
+  AddString(g_form_data_msg);
+  AddItem(msg_type, msg_type_size);
+  AddString(g_quote_msg);
+  AddString(g_rn);
+  AddString(g_rn);
+  AddItem(msg_data, msg_data_size);
+  AddString(g_rn);
+}
+
+void MimeWriter::AddPairDataInChunks(const char* msg_type,
+                                     size_t msg_type_size,
+                                     const char* msg_data,
+                                     size_t msg_data_size,
+                                     size_t chunk_size,
+                                     bool strip_trailing_spaces) {
+  if (chunk_size > kMaxCrashChunkSize)
+    return;
+
+  unsigned i = 0;
+  size_t done = 0, msg_length = msg_data_size;
+
+  while (msg_length) {
+    char num[kUint64StringSize];
+    const unsigned num_len = my_uint_len(++i);
+    my_uitos(num, i, num_len);
+
+    size_t chunk_len = std::min(chunk_size, msg_length);
+
+    AddString(g_form_data_msg);
+    AddItem(msg_type, msg_type_size);
+    AddItem(num, num_len);
+    AddString(g_quote_msg);
+    AddString(g_rn);
+    AddString(g_rn);
+    if (strip_trailing_spaces) {
+      AddItemWithoutTrailingSpaces(msg_data + done, chunk_len);
+    } else {
+      AddItem(msg_data + done, chunk_len);
+    }
+    AddString(g_rn);
+    AddBoundary();
+    Flush();
+
+    done += chunk_len;
+    msg_length -= chunk_len;
+  }
+}
+
+void MimeWriter::AddFileContents(const char* filename_msg,
+                                 uint8_t* file_data,
+                                 size_t file_size) {
+  AddString(g_form_data_msg);
+  AddString(filename_msg);
+  AddString(g_rn);
+  AddString(g_content_type_msg);
+  AddString(g_rn);
+  AddString(g_rn);
+  AddItem(file_data, file_size);
+  AddString(g_rn);
+}
+
+void MimeWriter::AddItem(const void* base, size_t size) {
+  // Check if the iovec is full and needs to be flushed to output file.
+  if (iov_index_ == kIovCapacity) {
+    Flush();
+  }
+  iov_[iov_index_].iov_base = const_cast<void*>(base);
+  iov_[iov_index_].iov_len = size;
+  ++iov_index_;
+}
+
+void MimeWriter::AddItemWithoutTrailingSpaces(const void* base, size_t size) {
+  AddItem(base,
+          LengthWithoutTrailingSpaces(static_cast<const char*>(base), size));
+}
+
+void DumpProcess() {
+  if (g_breakpad)
+    g_breakpad->WriteMinidump();
+}
+
+#if defined(OS_ANDROID)
+const char kGoogleBreakpad[] = "google-breakpad";
+#endif
+
+size_t WriteLog(const char* buf, size_t nbytes) {
+#if defined(OS_ANDROID)
+  return __android_log_write(ANDROID_LOG_WARN, kGoogleBreakpad, buf);
+#else
+  return sys_write(2, buf, nbytes);
+#endif
+}
+
+size_t WriteNewline() {
+  return WriteLog("\n", 1);
+}
+
+#if defined(OS_ANDROID)
+void AndroidLogWriteHorizontalRule() {
+  __android_log_write(ANDROID_LOG_WARN, kGoogleBreakpad,
+                      "### ### ### ### ### ### ### ### ### ### ### ### ###");
+}
+
+// Android's native crash handler outputs a diagnostic tombstone to the device
+// log. By returning false from the HandlerCallbacks, breakpad will reinstall
+// the previous (i.e. native) signal handlers before returning from its own
+// handler. A Mojo shell build fingerprint is written to the log, so that the
+// specific build of the shell and the location of the archived shell symbols
+// can be determined directly from it.
+bool FinalizeCrashDoneAndroid() {
+  base::android::BuildInfo* android_build_info =
+      base::android::BuildInfo::GetInstance();
+
+  AndroidLogWriteHorizontalRule();
+  __android_log_write(ANDROID_LOG_WARN, kGoogleBreakpad,
+                      "Mojo shell build fingerprint:");
+  __android_log_write(ANDROID_LOG_WARN, kGoogleBreakpad,
+                      android_build_info->package_version_name());
+  __android_log_write(ANDROID_LOG_WARN, kGoogleBreakpad,
+                      android_build_info->package_version_code());
+  AndroidLogWriteHorizontalRule();
+
+  return false;
+}
+#endif
+
+bool CrashDone(const MinidumpDescriptor& minidump, const bool succeeded) {
+  // WARNING: this code runs in a compromised context. It may not call into
+  // libc nor allocate memory normally.
+  if (!succeeded) {
+    const char msg[] = "Failed to generate minidump.";
+    WriteLog(msg, sizeof(msg) - 1);
+    return false;
+  }
+
+  DCHECK(!minidump.IsFD());
+
+  BreakpadInfo info = {0};
+  info.filename = minidump.path();
+  info.fd = minidump.fd();
+  info.process_type = "shell";
+  info.process_type_length = 7;
+  info.distro = base::g_linux_distro;
+  info.distro_length = my_strlen(base::g_linux_distro);
+  info.process_start_time = g_process_start_time;
+  info.oom_size = base::g_oom_size;
+  info.pid = g_pid;
+  info.crash_keys = g_crash_keys;
+  HandleCrashDump(info);
+#if defined(OS_ANDROID)
+  return FinalizeCrashDoneAndroid();
+#else
+  return true;
+#endif
+}
+
+// Wrapper function, do not add more code here.
+bool CrashDoneNoUpload(const MinidumpDescriptor& minidump,
+                       void* context,
+                       bool succeeded) {
+  return CrashDone(minidump, succeeded);
+}
+
+void EnableCrashDumping(const base::FilePath& dumps_path) {
+  g_is_crash_reporter_enabled = true;
+
+  base::FilePath tmp_path("/tmp");
+  PathService::Get(base::DIR_TEMP, &tmp_path);
+
+  base::FilePath logfile = dumps_path.Append("uploads.log");
+  std::string logfile_str = logfile.value();
+  const size_t crash_log_path_len = logfile_str.size() + 1;
+  g_crash_log_path = new char[crash_log_path_len];
+  strncpy(g_crash_log_path, logfile_str.c_str(), crash_log_path_len);
+  DCHECK(!g_breakpad);
+  MinidumpDescriptor minidump_descriptor(dumps_path.value());
+  if (base::CommandLine::ForCurrentProcess()->HasSwitch(
+          switches::kFullMemoryCrashReport)) {
+    minidump_descriptor.set_size_limit(-1);  // unlimited.
+  } else {
+    minidump_descriptor.set_size_limit(kMaxMinidumpFileSize);
+  }
+  g_breakpad = new ExceptionHandler(
+      minidump_descriptor, nullptr, CrashDoneNoUpload, nullptr,
+      true,  // Install handlers.
+      -1);   // Server file descriptor. -1 for in-process.
+}
+
+void SetCrashKeyValue(const base::StringPiece& key,
+                      const base::StringPiece& value) {
+  g_crash_keys->SetKeyValue(key.data(), value.data());
+}
+
+void ClearCrashKey(const base::StringPiece& key) {
+  g_crash_keys->RemoveKey(key.data());
+}
+
+void RegisterCrashKeys() {
+  // TODO(qsr): Is there any key we want to put.
+}
+
+void InitCrashKeys() {
+  g_crash_keys = new CrashKeyStorage;
+  RegisterCrashKeys();
+  base::debug::SetCrashKeyReportingFunctions(&SetCrashKeyValue, &ClearCrashKey);
+}
+
+// Miscellaneous initialization functions to call after Breakpad has been
+// enabled.
+void PostEnableBreakpadInitialization() {
+  SetProcessStartTime();
+  g_pid = getpid();
+
+  base::debug::SetDumpWithoutCrashingFunction(&DumpProcess);
+}
+
+}  // namespace
+
+void LoadDataFromFD(google_breakpad::PageAllocator& allocator,
+                    int fd,
+                    bool close_fd,
+                    uint8_t** file_data,
+                    size_t* size) {
+  STAT_STRUCT st;
+  if (FSTAT_FUNC(fd, &st) != 0) {
+    static const char msg[] = "Cannot upload crash dump: stat failed\n";
+    WriteLog(msg, sizeof(msg) - 1);
+    if (close_fd)
+      IGNORE_RET(sys_close(fd));
+    return;
+  }
+
+  *file_data = reinterpret_cast<uint8_t*>(allocator.Alloc(st.st_size));
+  if (!(*file_data)) {
+    static const char msg[] = "Cannot upload crash dump: cannot alloc\n";
+    WriteLog(msg, sizeof(msg) - 1);
+    if (close_fd)
+      IGNORE_RET(sys_close(fd));
+    return;
+  }
+  my_memset(*file_data, 0xf, st.st_size);
+
+  *size = st.st_size;
+  int byte_read = sys_read(fd, *file_data, *size);
+  if (byte_read == -1) {
+    static const char msg[] = "Cannot upload crash dump: read failed\n";
+    WriteLog(msg, sizeof(msg) - 1);
+    if (close_fd)
+      IGNORE_RET(sys_close(fd));
+    return;
+  }
+
+  if (close_fd)
+    IGNORE_RET(sys_close(fd));
+}
+
+void LoadDataFromFile(google_breakpad::PageAllocator& allocator,
+                      const char* filename,
+                      int* fd,
+                      uint8_t** file_data,
+                      size_t* size) {
+  // WARNING: this code runs in a compromised context. It may not call into
+  // libc nor allocate memory normally.
+  *fd = sys_open(filename, O_RDONLY, 0);
+  *size = 0;
+
+  if (*fd < 0) {
+    static const char msg[] = "Cannot upload crash dump: failed to open\n";
+    WriteLog(msg, sizeof(msg) - 1);
+    return;
+  }
+
+  LoadDataFromFD(allocator, *fd, true, file_data, size);
+}
+
+// |buf| should be |expected_len| + 1 characters in size and nullptr terminated.
+bool IsValidCrashReportId(const char* buf,
+                          size_t bytes_read,
+                          size_t expected_len) {
+  if (bytes_read != expected_len)
+    return false;
+  for (size_t i = 0; i < bytes_read; ++i) {
+    if (!my_isxdigit(buf[i]))
+      return false;
+  }
+  return true;
+}
+
+// |buf| should be |expected_len| + 1 characters in size and nullptr terminated.
+void HandleCrashReportId(const char* buf,
+                         size_t bytes_read,
+                         size_t expected_len) {
+  WriteNewline();
+  if (!IsValidCrashReportId(buf, bytes_read, expected_len)) {
+    static const char msg[] = "Failed to get crash dump id.";
+    WriteLog(msg, sizeof(msg) - 1);
+    WriteNewline();
+
+    static const char id_msg[] = "Report Id: ";
+    WriteLog(id_msg, sizeof(id_msg) - 1);
+    WriteLog(buf, bytes_read);
+    WriteNewline();
+    return;
+  }
+
+  // Write crash dump id to stderr.
+  static const char msg[] = "Crash dump id: ";
+  WriteLog(msg, sizeof(msg) - 1);
+  WriteLog(buf, my_strlen(buf));
+  WriteNewline();
+
+  // Write crash dump id to crash log as: seconds_since_epoch,crash_id
+  struct kernel_timeval tv;
+  if (g_crash_log_path && !sys_gettimeofday(&tv, nullptr)) {
+    uint64_t time = kernel_timeval_to_ms(&tv) / 1000;
+    char time_str[kUint64StringSize];
+    const unsigned time_len = my_uint64_len(time);
+    my_uint64tos(time_str, time, time_len);
+
+    const int kLogOpenFlags = O_CREAT | O_WRONLY | O_APPEND | O_CLOEXEC;
+    int log_fd = sys_open(g_crash_log_path, kLogOpenFlags, 0600);
+    if (log_fd > 0) {
+      sys_write(log_fd, time_str, time_len);
+      sys_write(log_fd, ",", 1);
+      sys_write(log_fd, buf, my_strlen(buf));
+      sys_write(log_fd, "\n", 1);
+      IGNORE_RET(sys_close(log_fd));
+    }
+  }
+}
+
+void HandleCrashDump(const BreakpadInfo& info) {
+  int dumpfd;
+  bool keep_fd = false;
+  size_t dump_size;
+  uint8_t* dump_data;
+  google_breakpad::PageAllocator allocator;
+
+  if (info.fd != -1) {
+    // Dump is provided with an open FD.
+    keep_fd = true;
+    dumpfd = info.fd;
+
+    // The FD is pointing to the end of the file.
+    // Rewind, we'll read the data next.
+    if (lseek(dumpfd, 0, SEEK_SET) == -1) {
+      static const char msg[] =
+          "Cannot upload crash dump: failed to "
+          "reposition minidump FD\n";
+      WriteLog(msg, sizeof(msg) - 1);
+      IGNORE_RET(sys_close(dumpfd));
+      return;
+    }
+    LoadDataFromFD(allocator, info.fd, false, &dump_data, &dump_size);
+  } else {
+    // Dump is provided with a path.
+    keep_fd = false;
+    LoadDataFromFile(allocator, info.filename, &dumpfd, &dump_data, &dump_size);
+  }
+
+  // We need to build a MIME block for uploading to the server. Since we are
+  // going to fork and run wget, it needs to be written to a temp file.
+  const int ufd = sys_open("/dev/urandom", O_RDONLY, 0);
+  if (ufd < 0) {
+    static const char msg[] =
+        "Cannot upload crash dump because /dev/urandom"
+        " is missing\n";
+    WriteLog(msg, sizeof(msg) - 1);
+    return;
+  }
+
+  int temp_file_fd = -1;
+  if (keep_fd) {
+    LOG(WARNING) << "Keeping fd...";
+    temp_file_fd = dumpfd;
+    // Rewind the destination, we are going to overwrite it.
+    if (lseek(dumpfd, 0, SEEK_SET) == -1) {
+      static const char msg[] =
+          "Cannot upload crash dump: failed to "
+          "reposition minidump FD (2)\n";
+      WriteLog(msg, sizeof(msg) - 1);
+      IGNORE_RET(sys_close(dumpfd));
+      return;
+    }
+  } else {
+    LOG(WARNING) << "Opening file: " << info.filename;
+    temp_file_fd = sys_open(info.filename, O_WRONLY, 0600);
+    if (temp_file_fd < 0) {
+      static const char msg[] = "Failed to save crash dump: failed to open\n";
+      WriteLog(msg, sizeof(msg) - 1);
+      IGNORE_RET(sys_close(ufd));
+      return;
+    }
+  }
+
+  // The MIME boundary is 28 hyphens, followed by a 64-bit nonce and a NUL.
+  char mime_boundary[28 + 16 + 1];
+  my_memset(mime_boundary, '-', 28);
+  uint64_t boundary_rand;
+  sys_read(ufd, &boundary_rand, sizeof(boundary_rand));
+  write_uint64_hex(mime_boundary + 28, boundary_rand);
+  mime_boundary[28 + 16] = 0;
+  IGNORE_RET(sys_close(ufd));
+
+  // The MIME block looks like this:
+  //   BOUNDARY \r\n
+  //   Content-Disposition: form-data; name="prod" \r\n \r\n
+  //   MojoShell \r\n
+  //   BOUNDARY \r\n
+  //   Content-Disposition: form-data; name="ver" \r\n \r\n
+  //   1.2.3.4 \r\n
+  //   BOUNDARY \r\n
+  //
+  //   zero or one:
+  //   Content-Disposition: form-data; name="ptime" \r\n \r\n
+  //   abcdef \r\n
+  //   BOUNDARY \r\n
+  //
+  //   zero or one:
+  //   Content-Disposition: form-data; name="ptype" \r\n \r\n
+  //   abcdef \r\n
+  //   BOUNDARY \r\n
+  //
+  //   zero or one:
+  //   Content-Disposition: form-data; name="lsb-release" \r\n \r\n
+  //   abcdef \r\n
+  //   BOUNDARY \r\n
+  //
+  //   zero or one:
+  //   Content-Disposition: form-data; name="oom-size" \r\n \r\n
+  //   1234567890 \r\n
+  //   BOUNDARY \r\n
+  //
+  //   zero or more (up to CrashKeyStorage::num_entries = 64):
+  //   Content-Disposition: form-data; name=crash-key-name \r\n
+  //   crash-key-value \r\n
+  //   BOUNDARY \r\n
+  //
+  //   Content-Disposition: form-data; name="dump"; filename="dump" \r\n
+  //   Content-Type: application/octet-stream \r\n \r\n
+  //   <dump contents>
+  //   \r\n BOUNDARY -- \r\n
+
+  MimeWriter writer(temp_file_fd, mime_boundary);
+  {
+    writer.AddBoundary();
+    writer.AddPairString("prod", kProductName);
+    writer.AddBoundary();
+    writer.AddPairString("ver", kVersion);
+    writer.AddBoundary();
+    if (info.pid > 0) {
+      char pid_value_buf[kUint64StringSize];
+      uint64_t pid_value_len = my_uint64_len(info.pid);
+      my_uint64tos(pid_value_buf, info.pid, pid_value_len);
+      static const char pid_key_name[] = "pid";
+      writer.AddPairData(pid_key_name, sizeof(pid_key_name) - 1, pid_value_buf,
+                         pid_value_len);
+      writer.AddBoundary();
+    }
+#if defined(OS_ANDROID)
+    // Addtional MIME blocks are added for logging on Android devices.
+    static const char android_build_id[] = "android_build_id";
+    static const char android_build_fp[] = "android_build_fp";
+    static const char device[] = "device";
+    static const char model[] = "model";
+    static const char brand[] = "brand";
+    static const char exception_info[] = "exception_info";
+
+    base::android::BuildInfo* android_build_info =
+        base::android::BuildInfo::GetInstance();
+    writer.AddPairString(android_build_id,
+                         android_build_info->android_build_id());
+    writer.AddBoundary();
+    writer.AddPairString(android_build_fp,
+                         android_build_info->android_build_fp());
+    writer.AddBoundary();
+    writer.AddPairString(device, android_build_info->device());
+    writer.AddBoundary();
+    writer.AddPairString(model, android_build_info->model());
+    writer.AddBoundary();
+    writer.AddPairString(brand, android_build_info->brand());
+    writer.AddBoundary();
+    if (android_build_info->java_exception_info() != nullptr) {
+      writer.AddPairString(exception_info,
+                           android_build_info->java_exception_info());
+      writer.AddBoundary();
+    }
+#endif
+    writer.Flush();
+  }
+
+  if (info.process_start_time > 0) {
+    struct kernel_timeval tv;
+    if (!sys_gettimeofday(&tv, nullptr)) {
+      uint64_t time = kernel_timeval_to_ms(&tv);
+      if (time > info.process_start_time) {
+        time -= info.process_start_time;
+        char time_str[kUint64StringSize];
+        const unsigned time_len = my_uint64_len(time);
+        my_uint64tos(time_str, time, time_len);
+
+        static const char process_time_msg[] = "ptime";
+        writer.AddPairData(process_time_msg, sizeof(process_time_msg) - 1,
+                           time_str, time_len);
+        writer.AddBoundary();
+        writer.Flush();
+      }
+    }
+  }
+
+  if (info.process_type_length) {
+    writer.AddPairString("ptype", info.process_type);
+    writer.AddBoundary();
+    writer.Flush();
+  }
+
+  if (info.distro_length) {
+    static const char distro_msg[] = "lsb-release";
+    writer.AddPairString(distro_msg, info.distro);
+    writer.AddBoundary();
+    writer.Flush();
+  }
+
+  if (info.oom_size) {
+    char oom_size_str[kUint64StringSize];
+    const unsigned oom_size_len = my_uint64_len(info.oom_size);
+    my_uint64tos(oom_size_str, info.oom_size, oom_size_len);
+    static const char oom_size_msg[] = "oom-size";
+    writer.AddPairData(oom_size_msg, sizeof(oom_size_msg) - 1, oom_size_str,
+                       oom_size_len);
+    writer.AddBoundary();
+    writer.Flush();
+  }
+
+  if (info.crash_keys) {
+    CrashKeyStorage::Iterator crash_key_iterator(*info.crash_keys);
+    const CrashKeyStorage::Entry* entry;
+    while ((entry = crash_key_iterator.Next())) {
+      writer.AddPairString(entry->key, entry->value);
+      writer.AddBoundary();
+      writer.Flush();
+    }
+  }
+
+  writer.AddFileContents(g_dump_msg, dump_data, dump_size);
+  writer.AddEnd();
+  writer.Flush();
+
+  IGNORE_RET(sys_close(temp_file_fd));
+}
+
+void InitCrashReporter(const base::FilePath& dumps_path) {
+#if defined(OS_ANDROID)
+  // This will guarantee that the BuildInfo has been initialized and subsequent
+  // calls will not require memory allocation.
+  base::android::BuildInfo::GetInstance();
+#endif
+  // Determine the process type and take appropriate action.
+  const base::CommandLine& parsed_command_line =
+      *base::CommandLine::ForCurrentProcess();
+  if (parsed_command_line.HasSwitch(switches::kDisableBreakpad))
+    return;
+
+  bool enable_breakpad =
+      !parsed_command_line.HasSwitch(switches::kDisableBreakpad);
+  if (!enable_breakpad) {
+    enable_breakpad =
+        parsed_command_line.HasSwitch(switches::kEnableCrashReporterForTesting);
+  }
+  if (!enable_breakpad) {
+    VLOG(1) << "Breakpad disabled";
+    return;
+  }
+
+  InitCrashKeys();
+  EnableCrashDumping(dumps_path);
+
+  PostEnableBreakpadInitialization();
+}
+
+bool IsCrashReporterEnabled() {
+  return g_is_crash_reporter_enabled;
+}
+
+}  // namespace breakpad