Quoting Gordon W. Ross,

> The fact that old linux executables can not be mapped using perfectly
> valid POSIX restrictions is an unfortunate mistake in the design of
> that executable format.  This problem is sort of moot now that Linux
> has moved to  ELF instead.  Hopefully the new format can be mapped
> without violatating these restrictions.

Unfortunately, the current kern/exec_elf.c is not able to use demand
paging because of what seems to be (as far as I looked into it) another
restriction: vm_mmap wants the size to be page-aligned to. This restriction
seems unnecessary to me, or is it?

- Frank