151 lines
5.1 KiB
Plaintext
151 lines
5.1 KiB
Plaintext
# SPDX-License-Identifier: GPL-2.0-only
|
|
|
|
menu "Kexec and crash features"
|
|
|
|
config CRASH_CORE
|
|
bool
|
|
|
|
config KEXEC_CORE
|
|
select CRASH_CORE
|
|
bool
|
|
|
|
config KEXEC_ELF
|
|
bool
|
|
|
|
config HAVE_IMA_KEXEC
|
|
bool
|
|
|
|
config KEXEC
|
|
bool "Enable kexec system call"
|
|
depends on ARCH_SUPPORTS_KEXEC
|
|
select KEXEC_CORE
|
|
help
|
|
kexec is a system call that implements the ability to shutdown your
|
|
current kernel, and to start another kernel. It is like a reboot
|
|
but it is independent of the system firmware. And like a reboot
|
|
you can start any kernel with it, not just Linux.
|
|
|
|
The name comes from the similarity to the exec system call.
|
|
|
|
It is an ongoing process to be certain the hardware in a machine
|
|
is properly shutdown, so do not be surprised if this code does not
|
|
initially work for you. As of this writing the exact hardware
|
|
interface is strongly in flux, so no good recommendation can be
|
|
made.
|
|
|
|
config KEXEC_FILE
|
|
bool "Enable kexec file based system call"
|
|
depends on ARCH_SUPPORTS_KEXEC_FILE
|
|
select CRYPTO
|
|
select CRYPTO_SHA256
|
|
select KEXEC_CORE
|
|
help
|
|
This is new version of kexec system call. This system call is
|
|
file based and takes file descriptors as system call argument
|
|
for kernel and initramfs as opposed to list of segments as
|
|
accepted by kexec system call.
|
|
|
|
config KEXEC_SIG
|
|
bool "Verify kernel signature during kexec_file_load() syscall"
|
|
depends on ARCH_SUPPORTS_KEXEC_SIG
|
|
depends on KEXEC_FILE
|
|
help
|
|
This option makes the kexec_file_load() syscall check for a valid
|
|
signature of the kernel image. The image can still be loaded without
|
|
a valid signature unless you also enable KEXEC_SIG_FORCE, though if
|
|
there's a signature that we can check, then it must be valid.
|
|
|
|
In addition to this option, you need to enable signature
|
|
verification for the corresponding kernel image type being
|
|
loaded in order for this to work.
|
|
|
|
config KEXEC_SIG_FORCE
|
|
bool "Require a valid signature in kexec_file_load() syscall"
|
|
depends on ARCH_SUPPORTS_KEXEC_SIG_FORCE
|
|
depends on KEXEC_SIG
|
|
help
|
|
This option makes kernel signature verification mandatory for
|
|
the kexec_file_load() syscall.
|
|
|
|
config KEXEC_IMAGE_VERIFY_SIG
|
|
bool "Enable Image signature verification support (ARM)"
|
|
default ARCH_DEFAULT_KEXEC_IMAGE_VERIFY_SIG
|
|
depends on ARCH_SUPPORTS_KEXEC_IMAGE_VERIFY_SIG
|
|
depends on KEXEC_SIG
|
|
depends on EFI && SIGNED_PE_FILE_VERIFICATION
|
|
help
|
|
Enable Image signature verification support.
|
|
|
|
config KEXEC_BZIMAGE_VERIFY_SIG
|
|
bool "Enable bzImage signature verification support"
|
|
depends on ARCH_SUPPORTS_KEXEC_BZIMAGE_VERIFY_SIG
|
|
depends on KEXEC_SIG
|
|
depends on SIGNED_PE_FILE_VERIFICATION
|
|
select SYSTEM_TRUSTED_KEYRING
|
|
help
|
|
Enable bzImage signature verification support.
|
|
|
|
config KEXEC_JUMP
|
|
bool "kexec jump"
|
|
depends on ARCH_SUPPORTS_KEXEC_JUMP
|
|
depends on KEXEC && HIBERNATION
|
|
help
|
|
Jump between original kernel and kexeced kernel and invoke
|
|
code in physical address mode via KEXEC
|
|
|
|
config CRASH_DUMP
|
|
bool "kernel crash dumps"
|
|
depends on ARCH_SUPPORTS_CRASH_DUMP
|
|
select CRASH_CORE
|
|
select KEXEC_CORE
|
|
help
|
|
Generate crash dump after being started by kexec.
|
|
This should be normally only set in special crash dump kernels
|
|
which are loaded in the main kernel with kexec-tools into
|
|
a specially reserved region and then later executed after
|
|
a crash by kdump/kexec. The crash dump kernel must be compiled
|
|
to a memory address not used by the main kernel or BIOS using
|
|
PHYSICAL_START, or it must be built as a relocatable image
|
|
(CONFIG_RELOCATABLE=y).
|
|
For more details see Documentation/admin-guide/kdump/kdump.rst
|
|
|
|
For s390, this option also enables zfcpdump.
|
|
See also <file:Documentation/s390/zfcpdump.rst>
|
|
|
|
config CRASH_HOTPLUG
|
|
bool "Update the crash elfcorehdr on system configuration changes"
|
|
default y
|
|
depends on CRASH_DUMP && (HOTPLUG_CPU || MEMORY_HOTPLUG)
|
|
depends on ARCH_SUPPORTS_CRASH_HOTPLUG
|
|
help
|
|
Enable direct update to the crash elfcorehdr (which contains
|
|
the list of CPUs and memory regions to be dumped upon a crash)
|
|
in response to hot plug/unplug or online/offline of CPUs or
|
|
memory. This is a much more advanced approach than userspace
|
|
attempting that.
|
|
|
|
If unsure, say Y.
|
|
|
|
config CRASH_MAX_MEMORY_RANGES
|
|
int "Specify the maximum number of memory regions for the elfcorehdr"
|
|
default 8192
|
|
depends on CRASH_HOTPLUG
|
|
help
|
|
For the kexec_file_load() syscall path, specify the maximum number of
|
|
memory regions that the elfcorehdr buffer/segment can accommodate.
|
|
These regions are obtained via walk_system_ram_res(); eg. the
|
|
'System RAM' entries in /proc/iomem.
|
|
This value is combined with NR_CPUS_DEFAULT and multiplied by
|
|
sizeof(Elf64_Phdr) to determine the final elfcorehdr memory buffer/
|
|
segment size.
|
|
The value 8192, for example, covers a (sparsely populated) 1TiB system
|
|
consisting of 128MiB memblocks, while resulting in an elfcorehdr
|
|
memory buffer/segment size under 1MiB. This represents a sane choice
|
|
to accommodate both baremetal and virtual machine configurations.
|
|
|
|
For the kexec_load() syscall path, CRASH_MAX_MEMORY_RANGES is part of
|
|
the computation behind the value provided through the
|
|
/sys/kernel/crash_elfcorehdr_size attribute.
|
|
|
|
endmenu
|