Linux: Add Breakpad client.

chrome/browser/renderer_host/render_crash_handler_host_linux.cc

Index: chrome/browser/renderer_host/render_crash_handler_host_linux.cc
diff --git a/chrome/browser/renderer_host/render_crash_handler_host_linux.cc b/chrome/browser/renderer_host/render_crash_handler_host_linux.cc
new file mode 100644
index 0000000000000000000000000000000000000000..a7342c5328206fbd4d014c809cc6021d93e15652
--- /dev/null
+++ b/chrome/browser/renderer_host/render_crash_handler_host_linux.cc
@@ -0,0 +1,187 @@
+// Copyright (c) 2009 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 "chrome/browser/renderer_host/render_crash_handler_host_linux.h"
+
+#define __STDC_FORMAT_MACROS
+#include <stdint.h>
+#include <inttypes.h>
+
+#include <unistd.h>
+#include <sys/uio.h>
+#include <sys/socket.h>
+
+#include "base/eintr_wrapper.h"
+#include "base/logging.h"
+#include "base/message_loop.h"
+#include "base/rand_util.h"
+#include "base/string_util.h"
+#include "breakpad/linux/exception_handler.h"
+#include "breakpad/linux/linux_dumper.h"
+#include "breakpad/linux/minidump_writer.h"
+#include "chrome/app/breakpad_linux.h"
+#include "chrome/browser/chrome_thread.h"
+
+// Since RenderCrashHandlerHostLinux is a singleton, it's only destroyed at the
+// end of the processes lifetime, which is greater in span then the lifetime of
+// the IO message loop.
+template<> struct RunnableMethodTraits<RenderCrashHandlerHostLinux> {
+  static void RetainCallee(RenderCrashHandlerHostLinux*) { }
+  static void ReleaseCallee(RenderCrashHandlerHostLinux*) { }
+};
+
+RenderCrashHandlerHostLinux::RenderCrashHandlerHostLinux()
+    : renderer_socket_(-1),
+      browser_socket_(-1) {
+  int fds[2];
+  CHECK(socketpair(AF_UNIX, SOCK_DGRAM, 0, fds) == 0);
+  static const int on = 1;
+
+  // Enable passcred on the server end of the socket
+  CHECK(setsockopt(fds[1], SOL_SOCKET, SO_PASSCRED, &on, sizeof(on)) == 0);
+
+  renderer_socket_ = fds[0];
+  browser_socket_ = fds[1];
+
+  MessageLoop* ml = ChromeThread::GetMessageLoop(ChromeThread::IO);
+  ml->PostTask(FROM_HERE, NewRunnableMethod(
+        this, &RenderCrashHandlerHostLinux::Init));
+}
+
+RenderCrashHandlerHostLinux::~RenderCrashHandlerHostLinux() {
+  HANDLE_EINTR(close(renderer_socket_));
+  HANDLE_EINTR(close(browser_socket_));
+}
+
+void RenderCrashHandlerHostLinux::Init() {
+  MessageLoopForIO* ml = MessageLoopForIO::current();
+  CHECK(ml->WatchFileDescriptor(
+      browser_socket_, true /* persistent */,
+      MessageLoopForIO::WATCH_READ,
+      &file_descriptor_watcher_, this));
+  ml->AddDestructionObserver(this);
+}
+
+void RenderCrashHandlerHostLinux::OnFileCanWriteWithoutBlocking(int fd) {
+  DCHECK(false);
+}
+
+void RenderCrashHandlerHostLinux::OnFileCanReadWithoutBlocking(int fd) {
+  DCHECK_EQ(fd, browser_socket_);
+
+  // A renderer 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 length of the control message:
+  static const unsigned kControlMsgSize =
+      CMSG_SPACE(sizeof(int)) + CMSG_SPACE(sizeof(struct ucred));
+  // The length of the regular payload:
+  static const unsigned kCrashContextSize =
+      sizeof(google_breakpad::ExceptionHandler::CrashContext);
+  static const unsigned kMaxActiveURLSize = 1024;
+
+  struct msghdr msg = {0};
+  struct iovec iov;
+  char context[kCrashContextSize + kMaxActiveURLSize];
+  char control[kControlMsgSize];
+  iov.iov_base = context;
+  iov.iov_len = sizeof(context);
+  msg.msg_iov = &iov;
+  msg.msg_iovlen = 1;
+  msg.msg_control = control;
+  msg.msg_controllen = kControlMsgSize;
+
+  const ssize_t n = HANDLE_EINTR(recvmsg(browser_socket_, &msg, 0));
+  if (n < 1) {
+    LOG(ERROR) << "Error reading from death signal socket. Crash dumping"
+               << " is disabled."
+               << " n:" << n
+               << " errno:" << errno;
+    file_descriptor_watcher_.StopWatchingFileDescriptor();
+    return;
+  }
+
+  if (n < static_cast<ssize_t>(kCrashContextSize) ||
+      msg.msg_controllen != kControlMsgSize ||
+      msg.msg_flags & ~MSG_TRUNC) {
+    LOG(ERROR) << "Received death signal message with the wrong size;"
+               << " n:" << n
+               << " msg.msg_controllen:" << msg.msg_controllen
+               << " msg.msg_flags:" << msg.msg_flags
+               << " kCrashContextSize:" << kCrashContextSize
+               << " kControlMsgSize:" << kControlMsgSize;
+    return;
+  }
+
+  // Anything in the message contents after the crash context is the crashing
+  // URL.
+  const char* const crash_url = &context[kCrashContextSize];
+  const unsigned crash_url_len = n - kCrashContextSize;
+
+  // Walk the control payload an extract the file descriptor and validated pid.
+  pid_t crashing_pid = -1;
+  int signal_fd = -1;
+  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 unsigned len = hdr->cmsg_len -
+          (((uint8_t*)CMSG_DATA(hdr)) - (uint8_t*)hdr);
+      DCHECK(len % sizeof(int) == 0);
+      const unsigned num_fds = len / sizeof(int);
+      if (num_fds > 1 || num_fds == 0) {
+        // A nasty renderer could try and send us too many descriptors and
+        // force a leak.
+        LOG(ERROR) << "Death signal contained too many descriptors;"
+                   << " num_fds:" << num_fds;
+        for (unsigned i = 0; i < num_fds; ++i)
+          HANDLE_EINTR(close(reinterpret_cast<int*>(CMSG_DATA(hdr))[i]));
+        return;
+      } else {
+        signal_fd = reinterpret_cast<int*>(CMSG_DATA(hdr))[0];
+      }
+    } else if (hdr->cmsg_type == SCM_CREDENTIALS) {
+      const struct ucred *cred =
+          reinterpret_cast<struct ucred*>(CMSG_DATA(hdr));
+      crashing_pid = cred->pid;
+    }
+  }
+
+  if (crashing_pid == -1 || signal_fd == -1) {
+    LOG(ERROR) << "Death signal message didn't contain all expected control"
+               << " messages";
+    if (signal_fd)
+      HANDLE_EINTR(close(signal_fd));
+    return;
+  }
+
+  const uint64 rand = base::RandUint64();
+  const std::string minidump_filename =
+      StringPrintf("/tmp/chromium-renderer-minidump-%016" PRIx64 ".dmp", rand);
+  if (!google_breakpad::WriteMinidump(minidump_filename.c_str(),
+                                      crashing_pid, context,
+                                      kCrashContextSize)) {
+    LOG(ERROR) << "Failed to write crash dump for pid " << crashing_pid;
+    HANDLE_EINTR(close(signal_fd));
+  }
+
+  // Send the done signal to the renderer: it can exit now.
+  memset(&msg, 0, sizeof(msg));
+  iov.iov_base = const_cast<char*>("\x42");
+  iov.iov_len = 1;
+  msg.msg_iov = &iov;
+  msg.msg_iovlen = 1;
+
+  HANDLE_EINTR(sendmsg(signal_fd, &msg, MSG_DONTWAIT | MSG_NOSIGNAL));
+  HANDLE_EINTR(close(signal_fd));
+
+  UploadCrashDump(minidump_filename.c_str(), crash_url, crash_url_len);
+}
+
+void RenderCrashHandlerHostLinux::WillDestroyCurrentMessageLoop() {
+  file_descriptor_watcher_.StopWatchingFileDescriptor();
+}