Turn components/crash into a layered component.

components/crash/browser/crash_handler_host_linux.cc

Index: components/crash/browser/crash_handler_host_linux.cc
diff --git a/components/crash/browser/crash_handler_host_linux.cc b/components/crash/browser/crash_handler_host_linux.cc
deleted file mode 100644
index 0f68216c44ff92d95a612203c940cdaa73b32d9b..0000000000000000000000000000000000000000
--- a/components/crash/browser/crash_handler_host_linux.cc
+++ /dev/null
@@ -1,437 +0,0 @@
-// Copyright 2013 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#include "components/crash/browser/crash_handler_host_linux.h"
-
-#include <stdint.h>
-#include <stdlib.h>
-#include <sys/socket.h>
-#include <sys/syscall.h>
-#include <unistd.h>
-
-#include "base/bind.h"
-#include "base/bind_helpers.h"
-#include "base/files/file_path.h"
-#include "base/files/file_util.h"
-#include "base/files/scoped_file.h"
-#include "base/format_macros.h"
-#include "base/linux_util.h"
-#include "base/location.h"
-#include "base/logging.h"
-#include "base/path_service.h"
-#include "base/posix/eintr_wrapper.h"
-#include "base/rand_util.h"
-#include "base/single_thread_task_runner.h"
-#include "base/strings/string_util.h"
-#include "base/strings/stringprintf.h"
-#include "base/threading/thread.h"
-#include "breakpad/src/client/linux/handler/exception_handler.h"
-#include "breakpad/src/client/linux/minidump_writer/linux_dumper.h"
-#include "breakpad/src/client/linux/minidump_writer/minidump_writer.h"
-#include "components/crash/app/breakpad_linux_impl.h"
-#include "content/public/browser/browser_thread.h"
-
-#if defined(OS_ANDROID) && !defined(__LP64__)
-#include <sys/linux-syscalls.h>
-
-#define SYS_read __NR_read
-#endif
-
-using content::BrowserThread;
-using google_breakpad::ExceptionHandler;
-
-namespace breakpad {
-
-namespace {
-
-const size_t kNumFDs = 1;
-// The length of the control message:
-const size_t kControlMsgSize =
-    CMSG_SPACE(kNumFDs * sizeof(int)) + CMSG_SPACE(sizeof(struct ucred));
-// The length of the regular payload:
-const size_t kCrashContextSize = sizeof(ExceptionHandler::CrashContext);
-
-// Handles the crash dump and frees the allocated BreakpadInfo struct.
-void CrashDumpTask(CrashHandlerHostLinux* handler,
-                   scoped_ptr<BreakpadInfo> info) {
-  if (handler->IsShuttingDown() && info->upload) {
-    base::DeleteFile(base::FilePath(info->filename), false);
-#if defined(ADDRESS_SANITIZER)
-    base::DeleteFile(base::FilePath(info->log_filename), false);
-#endif
-    return;
-  }
-
-  HandleCrashDump(*info);
-  delete[] info->filename;
-#if defined(ADDRESS_SANITIZER)
-  delete[] info->log_filename;
-  delete[] info->asan_report_str;
-#endif
-  delete[] info->process_type;
-  delete[] info->distro;
-  delete info->crash_keys;
-}
-
-}  // namespace
-
-// Since instances of CrashHandlerHostLinux are leaked, they are only destroyed
-// at the end of the processes lifetime, which is greater in span than the
-// lifetime of the IO message loop. Thus, all calls to base::Bind() use
-// non-refcounted pointers.
-
-CrashHandlerHostLinux::CrashHandlerHostLinux(const std::string& process_type,
-                                             const base::FilePath& dumps_path,
-                                             bool upload)
-    : process_type_(process_type),
-      dumps_path_(dumps_path),
-      upload_(upload),
-      shutting_down_(false),
-      worker_pool_token_(BrowserThread::GetBlockingPool()->GetSequenceToken()) {
-  int fds[2];
-  // We use SOCK_SEQPACKET rather than SOCK_DGRAM to prevent the process from
-  // sending datagrams to other sockets on the system. The sandbox may prevent
-  // the process from calling socket() to create new sockets, but it'll still
-  // inherit some sockets. With PF_UNIX+SOCK_DGRAM, it can call sendmsg to send
-  // a datagram to any (abstract) socket on the same system. With
-  // SOCK_SEQPACKET, this is prevented.
-  CHECK_EQ(0, socketpair(AF_UNIX, SOCK_SEQPACKET, 0, fds));
-  static const int on = 1;
-
-  // Enable passcred on the server end of the socket
-  CHECK_EQ(0, setsockopt(fds[1], SOL_SOCKET, SO_PASSCRED, &on, sizeof(on)));
-
-  process_socket_ = fds[0];
-  browser_socket_ = fds[1];
-
-  BrowserThread::PostTask(
-      BrowserThread::IO, FROM_HERE,
-      base::Bind(&CrashHandlerHostLinux::Init, base::Unretained(this)));
-}
-
-CrashHandlerHostLinux::~CrashHandlerHostLinux() {
-  close(process_socket_);
-  close(browser_socket_);
-}
-
-void CrashHandlerHostLinux::StartUploaderThread() {
-  uploader_thread_.reset(
-      new base::Thread(process_type_ + "_crash_uploader"));
-  uploader_thread_->Start();
-}
-
-void CrashHandlerHostLinux::Init() {
-  base::MessageLoopForIO* ml = base::MessageLoopForIO::current();
-  CHECK(ml->WatchFileDescriptor(
-      browser_socket_, true /* persistent */,
-      base::MessageLoopForIO::WATCH_READ,
-      &file_descriptor_watcher_, this));
-  ml->AddDestructionObserver(this);
-}
-
-void CrashHandlerHostLinux::OnFileCanWriteWithoutBlocking(int fd) {
-  NOTREACHED();
-}
-
-void CrashHandlerHostLinux::OnFileCanReadWithoutBlocking(int fd) {
-  DCHECK_EQ(browser_socket_, fd);
-
-  // A process has crashed and has signaled us by writing a datagram
-  // to the death signal socket. The datagram contains the crash context needed
-  // for writing the minidump as well as a file descriptor and a credentials
-  // block so that they can't lie about their pid.
-  //
-  // The message sender is in components/crash/app/breakpad_linux.cc.
-
-  struct msghdr msg = {0};
-  struct iovec iov[kCrashIovSize];
-
-  scoped_ptr<char[]> crash_context(new char[kCrashContextSize]);
-#if defined(ADDRESS_SANITIZER)
-  scoped_ptr<char[]> asan_report(new char[kMaxAsanReportSize + 1]);
-#endif
-
-  scoped_ptr<CrashKeyStorage> crash_keys(new CrashKeyStorage);
-  google_breakpad::SerializedNonAllocatingMap* serialized_crash_keys;
-  size_t crash_keys_size = crash_keys->Serialize(
-      const_cast<const google_breakpad::SerializedNonAllocatingMap**>(
-          &serialized_crash_keys));
-
-  char* tid_buf_addr = NULL;
-  int tid_fd = -1;
-  uint64_t uptime;
-  size_t oom_size;
-  char control[kControlMsgSize];
-  const ssize_t expected_msg_size =
-      kCrashContextSize +
-      sizeof(tid_buf_addr) + sizeof(tid_fd) +
-      sizeof(uptime) +
-#if defined(ADDRESS_SANITIZER)
-      kMaxAsanReportSize + 1 +
-#endif
-      sizeof(oom_size) +
-      crash_keys_size;
-  iov[0].iov_base = crash_context.get();
-  iov[0].iov_len = kCrashContextSize;
-  iov[1].iov_base = &tid_buf_addr;
-  iov[1].iov_len = sizeof(tid_buf_addr);
-  iov[2].iov_base = &tid_fd;
-  iov[2].iov_len = sizeof(tid_fd);
-  iov[3].iov_base = &uptime;
-  iov[3].iov_len = sizeof(uptime);
-  iov[4].iov_base = &oom_size;
-  iov[4].iov_len = sizeof(oom_size);
-  iov[5].iov_base = serialized_crash_keys;
-  iov[5].iov_len = crash_keys_size;
-#if !defined(ADDRESS_SANITIZER)
-  static_assert(5 == kCrashIovSize - 1, "kCrashIovSize should equal 6");
-#else
-  iov[6].iov_base = asan_report.get();
-  iov[6].iov_len = kMaxAsanReportSize + 1;
-  static_assert(6 == kCrashIovSize - 1, "kCrashIovSize should equal 7");
-#endif
-  msg.msg_iov = iov;
-  msg.msg_iovlen = kCrashIovSize;
-  msg.msg_control = control;
-  msg.msg_controllen = kControlMsgSize;
-
-  const ssize_t msg_size = HANDLE_EINTR(recvmsg(browser_socket_, &msg, 0));
-  if (msg_size < 0) {
-    LOG(ERROR) << "Error reading from death signal socket. Crash dumping"
-               << " is disabled."
-               << " msg_size:" << msg_size
-               << " errno:" << errno;
-    file_descriptor_watcher_.StopWatchingFileDescriptor();
-    return;
-  }
-  const bool bad_message = (msg_size != expected_msg_size ||
-                            msg.msg_controllen != kControlMsgSize ||
-                            msg.msg_flags & ~MSG_TRUNC);
-  base::ScopedFD signal_fd;
-  pid_t crashing_pid = -1;
-  if (msg.msg_controllen > 0) {
-    // Walk the control payload and extract the file descriptor and
-    // validated pid.
-    for (struct cmsghdr *hdr = CMSG_FIRSTHDR(&msg); hdr;
-         hdr = CMSG_NXTHDR(&msg, hdr)) {
-      if (hdr->cmsg_level != SOL_SOCKET)
-        continue;
-      if (hdr->cmsg_type == SCM_RIGHTS) {
-        const size_t len = hdr->cmsg_len -
-            (((uint8_t*)CMSG_DATA(hdr)) - (uint8_t*)hdr);
-        DCHECK_EQ(0U, len % sizeof(int));
-        const size_t num_fds = len / sizeof(int);
-        if (num_fds != kNumFDs) {
-          // A nasty process could try and send us too many descriptors and
-          // force a leak.
-          LOG(ERROR) << "Death signal contained wrong number of descriptors;"
-                     << " num_fds:" << num_fds;
-          for (size_t i = 0; i < num_fds; ++i)
-            close(reinterpret_cast<int*>(CMSG_DATA(hdr))[i]);
-          return;
-        }
-        DCHECK(!signal_fd.is_valid());
-        int fd = reinterpret_cast<int*>(CMSG_DATA(hdr))[0];
-        DCHECK_GE(fd, 0);  // The kernel should never send a negative fd.
-        signal_fd.reset(fd);
-      } else if (hdr->cmsg_type == SCM_CREDENTIALS) {
-        DCHECK_EQ(-1, crashing_pid);
-        const struct ucred *cred =
-            reinterpret_cast<struct ucred*>(CMSG_DATA(hdr));
-        crashing_pid = cred->pid;
-      }
-    }
-  }
-
-  if (bad_message) {
-    LOG(ERROR) << "Received death signal message with the wrong size;"
-               << " msg.msg_controllen:" << msg.msg_controllen
-               << " msg.msg_flags:" << msg.msg_flags
-               << " kCrashContextSize:" << kCrashContextSize
-               << " kControlMsgSize:" << kControlMsgSize;
-    return;
-  }
-  if (crashing_pid == -1 || !signal_fd.is_valid()) {
-    LOG(ERROR) << "Death signal message didn't contain all expected control"
-               << " messages";
-    return;
-  }
-
-  // The crashing TID set inside the compromised context via
-  // sys_gettid() in ExceptionHandler::HandleSignal might be wrong (if
-  // the kernel supports PID namespacing) and may need to be
-  // translated.
-  //
-  // We expect the crashing thread to be in sys_read(), waiting for us to
-  // write to |signal_fd|. Most newer kernels where we have the different pid
-  // namespaces also have /proc/[pid]/syscall, so we can look through
-  // |actual_crashing_pid|'s thread group and find the thread that's in the
-  // read syscall with the right arguments.
-
-  std::string expected_syscall_data;
-  // /proc/[pid]/syscall is formatted as follows:
-  // syscall_number arg1 ... arg6 sp pc
-  // but we just check syscall_number through arg3.
-  base::StringAppendF(&expected_syscall_data, "%d 0x%x %p 0x1 ",
-                      SYS_read, tid_fd, tid_buf_addr);
-  bool syscall_supported = false;
-  pid_t crashing_tid =
-      base::FindThreadIDWithSyscall(crashing_pid,
-                                    expected_syscall_data,
-                                    &syscall_supported);
-  if (crashing_tid == -1) {
-    // We didn't find the thread we want. Maybe it didn't reach
-    // sys_read() yet or the thread went away.  We'll just take a
-    // guess here and assume the crashing thread is the thread group
-    // leader.  If procfs syscall is not supported by the kernel, then
-    // we assume the kernel also does not support TID namespacing and
-    // trust the TID passed by the crashing process.
-    LOG(WARNING) << "Could not translate tid - assuming crashing thread is "
-        "thread group leader; syscall_supported=" << syscall_supported;
-    crashing_tid = crashing_pid;
-  }
-
-  ExceptionHandler::CrashContext* bad_context =
-      reinterpret_cast<ExceptionHandler::CrashContext*>(crash_context.get());
-  bad_context->tid = crashing_tid;
-
-  scoped_ptr<BreakpadInfo> info(new BreakpadInfo);
-
-  info->fd = -1;
-  info->process_type_length = process_type_.length();
-  // Freed in CrashDumpTask().
-  char* process_type_str = new char[info->process_type_length + 1];
-  process_type_.copy(process_type_str, info->process_type_length);
-  process_type_str[info->process_type_length] = '\0';
-  info->process_type = process_type_str;
-
-  // Memory released from scoped_ptrs below are also freed in CrashDumpTask().
-  info->crash_keys = crash_keys.release();
-#if defined(ADDRESS_SANITIZER)
-  asan_report[kMaxAsanReportSize] = '\0';
-  info->asan_report_str = asan_report.release();
-  info->asan_report_length = strlen(info->asan_report_str);
-#endif
-
-  info->process_start_time = uptime;
-  info->oom_size = oom_size;
-#if defined(OS_ANDROID)
-  // Nothing gets uploaded in android.
-  info->upload = false;
-#else
-  info->upload = upload_;
-#endif
-
-
-  BrowserThread::GetBlockingPool()->PostSequencedWorkerTask(
-      worker_pool_token_,
-      FROM_HERE,
-      base::Bind(&CrashHandlerHostLinux::WriteDumpFile,
-                 base::Unretained(this),
-                 base::Passed(&info),
-                 base::Passed(&crash_context),
-                 crashing_pid,
-                 signal_fd.release()));
-}
-
-void CrashHandlerHostLinux::WriteDumpFile(scoped_ptr<BreakpadInfo> info,
-                                          scoped_ptr<char[]> crash_context,
-                                          pid_t crashing_pid,
-                                          int signal_fd) {
-  DCHECK(BrowserThread::GetBlockingPool()->IsRunningSequenceOnCurrentThread(
-      worker_pool_token_));
-
-  // Set |info->distro| here because base::GetLinuxDistro() needs to run on a
-  // blocking thread.
-  std::string distro = base::GetLinuxDistro();
-  info->distro_length = distro.length();
-  // Freed in CrashDumpTask().
-  char* distro_str = new char[info->distro_length + 1];
-  distro.copy(distro_str, info->distro_length);
-  distro_str[info->distro_length] = '\0';
-  info->distro = distro_str;
-
-  base::FilePath dumps_path("/tmp");
-  PathService::Get(base::DIR_TEMP, &dumps_path);
-  if (!info->upload)
-    dumps_path = dumps_path_;
-  const std::string minidump_filename =
-      base::StringPrintf("%s/chromium-%s-minidump-%016" PRIx64 ".dmp",
-                         dumps_path.value().c_str(),
-                         process_type_.c_str(),
-                         base::RandUint64());
-
-  if (!google_breakpad::WriteMinidump(minidump_filename.c_str(),
-                                      kMaxMinidumpFileSize,
-                                      crashing_pid,
-                                      crash_context.get(),
-                                      kCrashContextSize,
-                                      google_breakpad::MappingList(),
-                                      google_breakpad::AppMemoryList())) {
-    LOG(ERROR) << "Failed to write crash dump for pid " << crashing_pid;
-  }
-#if defined(ADDRESS_SANITIZER)
-  // Create a temporary file holding the AddressSanitizer report.
-  const base::FilePath log_path =
-      base::FilePath(minidump_filename).ReplaceExtension("log");
-  base::WriteFile(log_path, info->asan_report_str, info->asan_report_length);
-#endif
-
-  // Freed in CrashDumpTask().
-  char* minidump_filename_str = new char[minidump_filename.length() + 1];
-  minidump_filename.copy(minidump_filename_str, minidump_filename.length());
-  minidump_filename_str[minidump_filename.length()] = '\0';
-  info->filename = minidump_filename_str;
-#if defined(ADDRESS_SANITIZER)
-  // Freed in CrashDumpTask().
-  char* minidump_log_filename_str = new char[minidump_filename.length() + 1];
-  minidump_filename.copy(minidump_log_filename_str, minidump_filename.length());
-  memcpy(minidump_log_filename_str + minidump_filename.length() - 3, "log", 3);
-  minidump_log_filename_str[minidump_filename.length()] = '\0';
-  info->log_filename = minidump_log_filename_str;
-#endif
-  info->pid = crashing_pid;
-
-  BrowserThread::PostTask(
-      BrowserThread::IO, FROM_HERE,
-      base::Bind(&CrashHandlerHostLinux::QueueCrashDumpTask,
-                 base::Unretained(this),
-                 base::Passed(&info),
-                 signal_fd));
-}
-
-void CrashHandlerHostLinux::QueueCrashDumpTask(scoped_ptr<BreakpadInfo> info,
-                                               int signal_fd) {
-  DCHECK_CURRENTLY_ON(BrowserThread::IO);
-
-  // Send the done signal to the process: it can exit now.
-  struct msghdr msg = {0};
-  struct iovec done_iov;
-  done_iov.iov_base = const_cast<char*>("\x42");
-  done_iov.iov_len = 1;
-  msg.msg_iov = &done_iov;
-  msg.msg_iovlen = 1;
-
-  HANDLE_EINTR(sendmsg(signal_fd, &msg, MSG_DONTWAIT | MSG_NOSIGNAL));
-  close(signal_fd);
-
-  uploader_thread_->task_runner()->PostTask(
-      FROM_HERE,
-      base::Bind(&CrashDumpTask, base::Unretained(this), base::Passed(&info)));
-}
-
-void CrashHandlerHostLinux::WillDestroyCurrentMessageLoop() {
-  file_descriptor_watcher_.StopWatchingFileDescriptor();
-
-  // If we are quitting and there are crash dumps in the queue, turn them into
-  // no-ops.
-  shutting_down_ = true;
-  uploader_thread_->Stop();
-}
-
-bool CrashHandlerHostLinux::IsShuttingDown() const {
-  return shutting_down_;
-}
-
-}  // namespace breakpad