IA64 is also vulnerable to the huge-vma-in-executable bug in 64 bit elf
support, it just insert a vma of zero page without checking overlap, so user
can construct a elf with section begin from 0x0 to trigger this BUGON().

However, I think it's safe to check overlap before we actually insert a vma
into vma list.  And I also feel check vma overlap everywhere is unnecessary,
because invert_vm_struct will check it again, so the check is duplicated.
It's better to have invert_vm_struct return a value then let caller check if
it successes.  Here is a patch against 2.6.10.rc2-mm3 I have tested it on
i386, x86_64 and ia64 machines.
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Zou Nan hai <Nanhai.zou@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>