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linux-pinenote/arch/x86/purgatory/entry64.S

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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>
2014-08-08 14:26:02 -07:00
/*
* Copyright (C) 2003,2004 Eric Biederman (ebiederm@xmission.com)
* Copyright (C) 2014 Red Hat Inc.
* Author(s): Vivek Goyal <vgoyal@redhat.com>
*
* This code has been taken from kexec-tools.
*
* This source code is licensed under the GNU General Public License,
* Version 2. See the file COPYING for more details.
*/
.text
.balign 16
.code64
.globl entry64, entry64_regs
entry64:
/* Setup a gdt that should be preserved */
lgdt gdt(%rip)
/* load the data segments */
movl $0x18, %eax /* data segment */
movl %eax, %ds
movl %eax, %es
movl %eax, %ss
movl %eax, %fs
movl %eax, %gs
/* Setup new stack */
leaq stack_init(%rip), %rsp
pushq $0x10 /* CS */
leaq new_cs_exit(%rip), %rax
pushq %rax
lretq
new_cs_exit:
/* Load the registers */
movq rax(%rip), %rax
movq rbx(%rip), %rbx
movq rcx(%rip), %rcx
movq rdx(%rip), %rdx
movq rsi(%rip), %rsi
movq rdi(%rip), %rdi
movq rsp(%rip), %rsp
movq rbp(%rip), %rbp
movq r8(%rip), %r8
movq r9(%rip), %r9
movq r10(%rip), %r10
movq r11(%rip), %r11
movq r12(%rip), %r12
movq r13(%rip), %r13
movq r14(%rip), %r14
movq r15(%rip), %r15
/* Jump to the new code... */
jmpq *rip(%rip)
.section ".rodata"
.balign 4
entry64_regs:
rax: .quad 0x0
rcx: .quad 0x0
rdx: .quad 0x0
kexec: support for kexec on panic using new system call 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>
2014-08-08 14:26:09 -07:00
rbx: .quad 0x0
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>
2014-08-08 14:26:02 -07:00
rsp: .quad 0x0
rbp: .quad 0x0
kexec: support for kexec on panic using new system call 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>
2014-08-08 14:26:09 -07:00
rsi: .quad 0x0
rdi: .quad 0x0
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>
2014-08-08 14:26:02 -07:00
r8: .quad 0x0
r9: .quad 0x0
r10: .quad 0x0
r11: .quad 0x0
r12: .quad 0x0
r13: .quad 0x0
r14: .quad 0x0
r15: .quad 0x0
rip: .quad 0x0
.size entry64_regs, . - entry64_regs
/* GDT */
.section ".rodata"
.balign 16
gdt:
/* 0x00 unusable segment
* 0x08 unused
* so use them as gdt ptr
*/
.word gdt_end - gdt - 1
.quad gdt
.word 0, 0, 0
/* 0x10 4GB flat code segment */
.word 0xFFFF, 0x0000, 0x9A00, 0x00AF
/* 0x18 4GB flat data segment */
.word 0xFFFF, 0x0000, 0x9200, 0x00CF
gdt_end:
stack: .quad 0, 0
stack_init:
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