Re: Fix handling of ELF segments with zero filesize

["H. Peter Anvin" <hpa@zytor.com>]

David Gibson wrote:
> Andrew, please apply
> 
> mmap() returns -EINVAL if given a zero length, and thus elf_map() in
> binfmt_elf.c does likewise if it attempts to map a (page-aligned) ELF
> segment with zero filesize.  Such a situation never arises with the
> default linker scripts, but there's nothing inherently wrong with
> zero-filesize (but non-zero memsize) ELF segments.  Custom linker
> scripts can generate them, and the kernel should be able to map them;
> this patch makes it so.
> 

More than that: even with some versions of the default linker scripts 
they can be created, according to reports I have received on the klibc 
mailing list.  It just doesn't happen with glibc binaries.

This is a real bug and should be fixed.

	-hpa