This patch adds support for loading a kexec on panic (kdump) kernel usning
new system call.
It prepares ELF headers for memory areas to be dumped and for saved cpu
registers. Also prepares the memory map for second kernel and limits its
boot to reserved areas only.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: Greg Kroah-Hartman <greg@kroah.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: WANG Chao <chaowang@redhat.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Create a stand alone relocatable object purgatory which runs between two
kernels. This name, concept and some code has been taken from
kexec-tools. Idea is that this code runs after a crash and it runs in
minimal environment. So keep it separate from rest of the kernel and in
long term we will have to practically do no maintenance of this code.
This code also has the logic to do verify sha256 hashes of various
segments which have been loaded into memory. So first we verify that the
kernel we are jumping to is fine and has not been corrupted and make
progress only if checsums are verified.
This code also takes care of copying some memory contents to backup region.
[sfr@canb.auug.org.au: run host built programs from objtree]
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: Greg Kroah-Hartman <greg@kroah.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: WANG Chao <chaowang@redhat.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Next two patches provide code for purgatory. This is a code which does
not link against the kernel and runs stand alone. This code runs between
two kernels. One of the primary purpose of this code is to verify the
digest of newly loaded kernel and making sure it matches the digest
computed at kernel load time.
We use sha256 for calculating digest of kexec segmetns. Purgatory can't
use stanard crypto API as that API is not available in purgatory context.
Hence, I have copied code from crypto/sha256_generic.c and compiled it
with purgaotry code so that it could be used. I could not #include
sha256_generic.c file here as some of the function signature requiered
little tweaking. Original functions work with crypto API but these ones
don't
So instead of doing #include on sha256_generic.c I just copied relevant
portions of code into arch/x86/purgatory/sha256.c. Now we shouldn't have
to touch this code at all. Do let me know if there are better ways to
handle it.
This patch does not enable compiling of this code. That happens in next
patch. I wanted to highlight this change in a separate patch for easy
review.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: Greg Kroah-Hartman <greg@kroah.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: WANG Chao <chaowang@redhat.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Vivek Goyal