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authorVivek Goyal <vgoyal@redhat.com>2014-08-08 14:26:02 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2014-08-08 15:57:32 -0700
commit8fc5b4d4121c95482b2583a07863c6b0aba2d9e1 (patch)
tree16ef44c15e9802c1aed83d8eead0569822268794 /arch/x86/purgatory/stack.S
parentdaeba0641a707626f3674db71016f333edf64395 (diff)
purgatory: core purgatory functionality
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>
Diffstat (limited to 'arch/x86/purgatory/stack.S')
-rw-r--r--arch/x86/purgatory/stack.S19
1 files changed, 19 insertions, 0 deletions
diff --git a/arch/x86/purgatory/stack.S b/arch/x86/purgatory/stack.S
new file mode 100644
index 000000000000..3cefba1fefc8
--- /dev/null
+++ b/arch/x86/purgatory/stack.S
@@ -0,0 +1,19 @@
+/*
+ * purgatory: stack
+ *
+ * Copyright (C) 2014 Red Hat Inc.
+ *
+ * This source code is licensed under the GNU General Public License,
+ * Version 2. See the file COPYING for more details.
+ */
+
+ /* A stack for the loaded kernel.
+ * Seperate and in the data section so it can be prepopulated.
+ */
+ .data
+ .balign 4096
+ .globl stack, stack_end
+
+stack:
+ .skip 4096
+stack_end: