Small security patches

[Pierre A. Humblet]

Christopher Faylor wrote:

> Shouldn't the global symbols be marked as "NO_COPY"?

I am not sure why things are as they are.
These symbols are initialized in do_global_ctors and never change.
Are the constructors running again after a fork? If so, NO_COPY is fine.
It would seem more efficient to copy than to rerun the constructors,
but I probably overlook some factors.

Pierre