linux: set FD_CLOEXEC on the singleton socket

The IME library may spawn a subprocess, which will then hold open
our singleton socket after we've shut down.

BUG=17952

Review URL: http://codereview.chromium.org/160523

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@22281 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 14 insertions, 0 deletions

diff --git a/chrome/browser/process_singleton_linux.cc b/chrome/browser/process_singleton_linux.cc
index eebbd39..f0d33e6 100644
--- a/chrome/browser/process_singleton_linux.cc
+++ b/chrome/browser/process_singleton_linux.cc
@@ -43,6 +43,7 @@ const char kTokenDelimiter = '\0';
 const int kTimeOutInSeconds = 5;
 const int kMaxMessageLength = 32 * 1024;
 
+// Set a file descriptor to be non-blocking.
 // Return 0 on success, -1 on failure.
 int SetNonBlocking(int fd) {
   int flags = fcntl(fd, F_GETFL, 0);
@@ -53,6 +54,17 @@ int SetNonBlocking(int fd) {
   return fcntl(fd, F_SETFL, flags | O_NONBLOCK);
 }
 
+// Set the close-on-exec bit on a file descriptor.
+// Returns 0 on success, -1 on failure.
+int SetCloseOnExec(int fd) {
+  int flags = fcntl(fd, F_GETFD, 0);
+  if (-1 == flags)
+    return flags;
+  if (flags & FD_CLOEXEC)
+    return 0;
+  return fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
+}
+
 }  // namespace
 
 ///////////////////////////////////////////////////////////////////////////////
@@ -428,6 +440,8 @@ void ProcessSingleton::SetupSocket(int* sock, struct sockaddr_un* addr) {
 
   int rv = SetNonBlocking(*sock);
   DCHECK_EQ(0, rv) << "Failed to make non-blocking socket.";
+  rv = SetCloseOnExec(*sock);
+  DCHECK_EQ(0, rv) << "Failed to set CLOEXEC on socket.";
 
   addr->sun_family = AF_UNIX;
   if (socket_path_.value().length() > sizeof(addr->sun_path) - 1)