Changing a Linux C++ program which gives the user limited file access. Thus the program chroots itself to a sandbox with the files the user can get at. All worked well.

Now, however, the program needs to access some files for its own needs (not the user's) but they are outside the sandbox. I know chroot allows access to files opened before the chroot but in this case the needed files could a few among many hundreds so it is obviously impractical to open them all just for the couple that might be required.

Is there any way to get at the files?