kexec: Avoid overwriting the current pgd (V4, x86_64)
This patch upgrades the x86_64-specific kexec code to avoid overwriting the
current pgd. Overwriting the current pgd is bad when CONFIG_CRASH_DUMP is used
to start a secondary kernel that dumps the memory of the previous kernel.
The code introduces a new set of page tables. These tables are used to provide
an executable identity mapping without overwriting the current pgd.
Signed-off-by: Magnus Damm <magnus@valinux.co.jp>
Signed-off-by: Andi Kleen <ak@suse.de>
This is the x86_64 implementation of machine kexec. 32bit compatibility
support has been implemented, and machine_kexec has been enhanced to not care
about the changing internal kernel paget table structures.
From: Alexander Nyberg <alexn@dsv.su.se>
build fix
Signed-off-by: Eric Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Thomas Gleixner