Make all of stdout/stderr/stdin pipes close-on-exec when spawing child processes.

runtime/bin/process_linux.cc

Index: runtime/bin/process_linux.cc
diff --git a/runtime/bin/process_linux.cc b/runtime/bin/process_linux.cc
index a511cd94f53082b3de6513789b59fceed49e8caf..0453ff648b5b25f7aa55e7bc921d2f885e7f0a06 100644
--- a/runtime/bin/process_linux.cc
+++ b/runtime/bin/process_linux.cc
@@ -378,34 +378,29 @@ class ProcessStarter {
  private:
   int CreatePipes() {

[Søren Gjesse, 2015/04/23 06:58:51]

Can't we then get rid of the explicit closing in the first four lines of
ProcessStarter::ExecProcess?

[Anders Johnsen, 2015/04/23 07:05:34]

You are right, it should be safe to remove those.

     int result;
-    result = TEMP_FAILURE_RETRY(pipe(exec_control_));
+    result = TEMP_FAILURE_RETRY(pipe2(exec_control_, O_CLOEXEC));
     if (result < 0) {
       return CleanupAndReturnError();
     }
-    FDUtils::SetCloseOnExec(exec_control_[0]);
-    FDUtils::SetCloseOnExec(exec_control_[1]);
 
     // For a detached process the pipe to connect stdout is still used for
     // signaling when to do the first fork.
-    result = TEMP_FAILURE_RETRY(pipe(read_in_));
+    result = TEMP_FAILURE_RETRY(pipe2(read_in_, O_CLOEXEC));
     if (result < 0) {
       return CleanupAndReturnError();
     }
-    FDUtils::SetCloseOnExec(read_in_[0]);
 
     // For detached processes the pipe to connect stderr and stdin are not used.
     if (mode_ != kDetached) {
-      result = TEMP_FAILURE_RETRY(pipe(read_err_));
+      result = TEMP_FAILURE_RETRY(pipe2(read_err_, O_CLOEXEC));
       if (result < 0) {
         return CleanupAndReturnError();
       }
-      FDUtils::SetCloseOnExec(read_err_[0]);
 
-      result = TEMP_FAILURE_RETRY(pipe(write_out_));
+      result = TEMP_FAILURE_RETRY(pipe2(write_out_, O_CLOEXEC));
       if (result < 0) {
         return CleanupAndReturnError();
       }
-      FDUtils::SetCloseOnExec(write_out_[1]);
     }
 
     return 0;
@@ -526,12 +521,10 @@ class ProcessStarter {
   int RegisterProcess(pid_t pid) {
     int result;
     int event_fds[2];
-    result = TEMP_FAILURE_RETRY(pipe(event_fds));
+    result = TEMP_FAILURE_RETRY(pipe2(event_fds, O_CLOEXEC));
     if (result < 0) {
       return CleanupAndReturnError();
     }
-    FDUtils::SetCloseOnExec(event_fds[0]);
-    FDUtils::SetCloseOnExec(event_fds[1]);
 
     ProcessInfoList::AddProcess(pid, event_fds[1]);
     *exit_event_ = event_fds[0];