Hello Alexey,
Looks like the following commit broke mmap for /proc/vmcore:
commit c4fe24485729fc2cbff324c111e67a1cc2f9adea
Author: Alexey Dobriyan <adobriyan at gmail.com>
Date: Tue Aug 20 22:17:24 2013 +0300
sparc: fix PCI device proc file mmap(2)
Because /proc/vmcore (fs/proc/vmcore.c) does not implement the
get_unmapped_area() fops function mmap now always returns EIO.
Michael
