Function reOpenDevNull

libcontainer/rootfs_linux.go:932–954

If stdin, stdout, and/or stderr are pointing to `/dev/null` in the parent's rootfs this method will make them point to `/dev/null` in this container's rootfs. This needs to be called after we chroot/pivot into the container's rootfs so that any symlinks are resolved locally.

()

// needs to be called after we chroot/pivot into the container's rootfs so that any
// symlinks are resolved locally.
func reOpenDevNull() error {
	file, err := os.OpenFile("/dev/null", os.O_RDWR, 0)
	if err != nil {
		return err
	}
	defer file.Close()
	if err := verifyDevNull(file); err != nil {
		return fmt.Errorf("can't reopen /dev/null: %w", err)
	}
	for fd := range 3 {
		var stat unix.Stat_t
		if err := unix.Fstat(fd, &stat); err != nil {
			return &os.PathError{Op: "fstat", Path: "fd " + strconv.Itoa(fd), Err: err}
		}
		if isDevNull(&stat) {
			// Close and re-open the fd.
			if err := linux.Dup3(int(file.Fd()), fd, 0); err != nil {
				return err
			}
		}
	}
	return nil
}

// Create the device nodes in the container.
func createDevices(rootFd *os.File, config *configs.Config) error {