vmcore, procfs: introduce a flag to distinguish objects copied in 2nd kernel

vmcore, procfs: introduce a flag to distinguish objects copied in 2nd kernel

The part of dump target memory is copied into the 2nd kernel if it doesn't
satisfy mmap()'s page-size boundary requirement.  To distinguish such
copied object from usual old memory, a flag MEM_TYPE_CURRENT_KERNEL is
introduced.  If this flag is set, the object is considered to have been
copied into a buffer on the 2nd kernel.

Signed-off-by: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>
Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>