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

runtime/bin/process_linux.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "platform/globals.h"
 #if defined(TARGET_OS_LINUX)
 
 #include "bin/process.h"
 
 #include <errno.h>  // NOLINT
@@ skipping 358 matching lines @@
       ASSERT(read_err_[1] == -1);
     }
     ASSERT(exec_control_[0] == -1);
     ASSERT(exec_control_[1] == -1);
 
     *id_ = pid;
     return 0;
   }
 
  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;
   }
 
 
   void NewProcess() {
     // Wait for parent process before setting up the child process.
     char msg;
     int bytes_read = FDUtils::ReadFromBlocking(read_in_[0], &msg, sizeof(msg));
@@ skipping 100 matching lines @@
     } else {
       // Exit the intermeiate process.
       exit(0);
     }
   }
 
 
   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];
     FDUtils::SetNonBlocking(event_fds[0]);
     return 0;
   }
 
 
   int ReadExecResult() {
     int child_errno;
@@ skipping 463 matching lines @@
     bzero(&act, sizeof(act));
     act.sa_handler = SIG_DFL;
     sigaction(signal, &act, NULL);
   }
 }
 
 }  // namespace bin
 }  // namespace dart
 
 #endif  // defined(TARGET_OS_LINUX)