The config options for kexec and crash features are consolidated
into new file kernel/Kconfig.kexec. Under the "General Setup" submenu
is a new submenu "Kexec and crash handling" where all the kexec and
crash options that were once in the arch-dependent submenu "Processor
type and features" are now consolidated.
The following options are impacted:
- KEXEC
- KEXEC_FILE
- KEXEC_SIG
- KEXEC_SIG_FORCE
- KEXEC_BZIMAGE_VERIFY_SIG
- KEXEC_JUMP
- CRASH_DUMP
The three main options are KEXEC, KEXEC_FILE and CRASH_DUMP.
Architectures specify support of certain KEXEC and CRASH features with
similarly named new ARCH_HAS_<option> config options.
Architectures can utilize the new ARCH_SUPPORTS_<option> config
options to specify additional components when <option> is enabled.
To summarize, the ARCH_HAS_<option> permits the <option> to be
enabled, and the ARCH_SUPPORTS_<option> handles side effects (ie.
select statements).
Signed-off-by: Eric DeVolder <eric.devolder@oracle.com>
---
arch/Kconfig | 13 ------
init/Kconfig | 2 +
kernel/Kconfig.kexec | 103 +++++++++++++++++++++++++++++++++++++++++++
3 files changed, 105 insertions(+), 13 deletions(-)
create mode 100644 kernel/Kconfig.kexec
diff --git a/arch/Kconfig b/arch/Kconfig
index 205fd23e0cad..a37730679730 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -11,19 +11,6 @@ source "arch/$(SRCARCH)/Kconfig"
menu "General architecture-dependent options"
-config CRASH_CORE
- bool
-
-config KEXEC_CORE
- select CRASH_CORE
- bool
-
-config KEXEC_ELF
- bool
-
-config HAVE_IMA_KEXEC
- bool
-
config ARCH_HAS_SUBPAGE_FAULTS
bool
help
diff --git a/init/Kconfig b/init/Kconfig
index 32c24950c4ce..4424447e23a5 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -1917,6 +1917,8 @@ config BINDGEN_VERSION_TEXT
config TRACEPOINTS
bool
+source "kernel/Kconfig.kexec"
+
endmenu # General setup
source "arch/Kconfig"
diff --git a/kernel/Kconfig.kexec b/kernel/Kconfig.kexec
new file mode 100644
index 000000000000..660048099865
--- /dev/null
+++ b/kernel/Kconfig.kexec
@@ -0,0 +1,103 @@
+# 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"
+ default ARCH_DEFAULT_KEXEC
+ depends on ARCH_HAS_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_HAS_KEXEC_FILE
+ 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 previous system call.
+
+config KEXEC_SIG
+ bool "Verify kernel signature during kexec_file_load() syscall"
+ depends on KEXEC_FILE && MODULE_SIG_FORMAT
+ 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 KEXEC_SIG
+ help
+ This option makes kernel signature verification mandatory for
+ the kexec_file_load() syscall.
+
+config KEXEC_BZIMAGE_VERIFY_SIG
+ bool "Enable bzImage signature verification support"
+ 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 KEXEC && HIBERNATION
+ depends on ARCH_HAS_KEXEC_JUMP
+ 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_HAS_CRASH_DUMP
+ select KEXEC_CORE
+ select CRASH_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>
+
+endmenu
--
2.31.1On Mon, Jun 12, 2023 at 01:27:53PM -0400, Eric DeVolder wrote: ... > +config KEXEC_FILE > + bool "Enable kexec file based system call" > + depends on ARCH_HAS_KEXEC_FILE > + 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 previous system call. Which "previous"? I guess, "by kexec system call" would sound clear. Thanks!
On 6/14/23 10:24, Alexander Gordeev wrote: > On Mon, Jun 12, 2023 at 01:27:53PM -0400, Eric DeVolder wrote: > ... >> +config KEXEC_FILE >> + bool "Enable kexec file based system call" >> + depends on ARCH_HAS_KEXEC_FILE >> + 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 previous system call. > > Which "previous"? I guess, "by kexec system call" would sound clear. > > Thanks! OK, will make that change! eric
On 2023/6/13 1:27, Eric DeVolder wrote: > The config options for kexec and crash features are consolidated > into new file kernel/Kconfig.kexec. Under the "General Setup" submenu > is a new submenu "Kexec and crash handling" where all the kexec and > crash options that were once in the arch-dependent submenu "Processor > type and features" are now consolidated. > > The following options are impacted: > > - KEXEC > - KEXEC_FILE > - KEXEC_SIG > - KEXEC_SIG_FORCE > - KEXEC_BZIMAGE_VERIFY_SIG > - KEXEC_JUMP > - CRASH_DUMP > > The three main options are KEXEC, KEXEC_FILE and CRASH_DUMP. > > Architectures specify support of certain KEXEC and CRASH features with > similarly named new ARCH_HAS_<option> config options. > > Architectures can utilize the new ARCH_SUPPORTS_<option> config > options to specify additional components when <option> is enabled. > > To summarize, the ARCH_HAS_<option> permits the <option> to be > enabled, and the ARCH_SUPPORTS_<option> handles side effects (ie. > select statements). > > Signed-off-by: Eric DeVolder <eric.devolder@oracle.com> > --- > arch/Kconfig | 13 ------ > init/Kconfig | 2 + > kernel/Kconfig.kexec | 103 +++++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 105 insertions(+), 13 deletions(-) > create mode 100644 kernel/Kconfig.kexec > > diff --git a/arch/Kconfig b/arch/Kconfig > index 205fd23e0cad..a37730679730 100644 > --- a/arch/Kconfig > +++ b/arch/Kconfig > @@ -11,19 +11,6 @@ source "arch/$(SRCARCH)/Kconfig" > > menu "General architecture-dependent options" > > -config CRASH_CORE > - bool > - > -config KEXEC_CORE > - select CRASH_CORE > - bool > - > -config KEXEC_ELF > - bool > - > -config HAVE_IMA_KEXEC > - bool > - > config ARCH_HAS_SUBPAGE_FAULTS > bool > help > diff --git a/init/Kconfig b/init/Kconfig > index 32c24950c4ce..4424447e23a5 100644 > --- a/init/Kconfig > +++ b/init/Kconfig > @@ -1917,6 +1917,8 @@ config BINDGEN_VERSION_TEXT > config TRACEPOINTS > bool > > +source "kernel/Kconfig.kexec" > + > endmenu # General setup > > source "arch/Kconfig" > diff --git a/kernel/Kconfig.kexec b/kernel/Kconfig.kexec > new file mode 100644 > index 000000000000..660048099865 > --- /dev/null > +++ b/kernel/Kconfig.kexec > @@ -0,0 +1,103 @@ > +# 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" > + default ARCH_DEFAULT_KEXEC > + depends on ARCH_HAS_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. "kernel. It is like", "firmware. And like" A few more spaces, I don't know the original author's intention, perhaps can be removed. > + > + 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_HAS_KEXEC_FILE > + 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 previous system call. > + > +config KEXEC_SIG > + bool "Verify kernel signature during kexec_file_load() syscall" > + depends on KEXEC_FILE && MODULE_SIG_FORMAT I see that there is no "depends on MODULE_SIG_FORMAT" on x86 and arm64. > + help > + This blank line can be deleted. > + 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 KEXEC_SIG > + help > + This option makes kernel signature verification mandatory for > + the kexec_file_load() syscall. > + > +config KEXEC_BZIMAGE_VERIFY_SIG > + bool "Enable bzImage signature verification support" > + 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 KEXEC && HIBERNATION > + depends on ARCH_HAS_KEXEC_JUMP > + 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_HAS_CRASH_DUMP > + select KEXEC_CORE > + select CRASH_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> > + > +endmenu > -- Regards, Zhen Lei
On 6/13/23 20:19, Leizhen (ThunderTown) wrote: > > > On 2023/6/13 1:27, Eric DeVolder wrote: >> The config options for kexec and crash features are consolidated >> into new file kernel/Kconfig.kexec. Under the "General Setup" submenu >> is a new submenu "Kexec and crash handling" where all the kexec and >> crash options that were once in the arch-dependent submenu "Processor >> type and features" are now consolidated. >> >> The following options are impacted: >> >> - KEXEC >> - KEXEC_FILE >> - KEXEC_SIG >> - KEXEC_SIG_FORCE >> - KEXEC_BZIMAGE_VERIFY_SIG >> - KEXEC_JUMP >> - CRASH_DUMP >> >> The three main options are KEXEC, KEXEC_FILE and CRASH_DUMP. >> >> Architectures specify support of certain KEXEC and CRASH features with >> similarly named new ARCH_HAS_<option> config options. >> >> Architectures can utilize the new ARCH_SUPPORTS_<option> config >> options to specify additional components when <option> is enabled. >> >> To summarize, the ARCH_HAS_<option> permits the <option> to be >> enabled, and the ARCH_SUPPORTS_<option> handles side effects (ie. >> select statements). >> >> Signed-off-by: Eric DeVolder <eric.devolder@oracle.com> >> --- >> arch/Kconfig | 13 ------ >> init/Kconfig | 2 + >> kernel/Kconfig.kexec | 103 +++++++++++++++++++++++++++++++++++++++++++ >> 3 files changed, 105 insertions(+), 13 deletions(-) >> create mode 100644 kernel/Kconfig.kexec >> >> diff --git a/arch/Kconfig b/arch/Kconfig >> index 205fd23e0cad..a37730679730 100644 >> --- a/arch/Kconfig >> +++ b/arch/Kconfig >> @@ -11,19 +11,6 @@ source "arch/$(SRCARCH)/Kconfig" >> >> menu "General architecture-dependent options" >> >> -config CRASH_CORE >> - bool >> - >> -config KEXEC_CORE >> - select CRASH_CORE >> - bool >> - >> -config KEXEC_ELF >> - bool >> - >> -config HAVE_IMA_KEXEC >> - bool >> - >> config ARCH_HAS_SUBPAGE_FAULTS >> bool >> help >> diff --git a/init/Kconfig b/init/Kconfig >> index 32c24950c4ce..4424447e23a5 100644 >> --- a/init/Kconfig >> +++ b/init/Kconfig >> @@ -1917,6 +1917,8 @@ config BINDGEN_VERSION_TEXT >> config TRACEPOINTS >> bool >> >> +source "kernel/Kconfig.kexec" >> + >> endmenu # General setup >> >> source "arch/Kconfig" >> diff --git a/kernel/Kconfig.kexec b/kernel/Kconfig.kexec >> new file mode 100644 >> index 000000000000..660048099865 >> --- /dev/null >> +++ b/kernel/Kconfig.kexec >> @@ -0,0 +1,103 @@ >> +# 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" >> + default ARCH_DEFAULT_KEXEC >> + depends on ARCH_HAS_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. > > "kernel. It is like", "firmware. And like" > > A few more spaces, I don't know the original author's intention, perhaps can be removed. > I'll remove the extra spaces. >> + >> + 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_HAS_KEXEC_FILE >> + 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 previous system call. >> + >> +config KEXEC_SIG >> + bool "Verify kernel signature during kexec_file_load() syscall" >> + depends on KEXEC_FILE && MODULE_SIG_FORMAT > > I see that there is no "depends on MODULE_SIG_FORMAT" on x86 and arm64. > Good catch, I'll remove MODULE_SIG_FORMAT and place it on just s390 (which is the only arch that had it this way). >> + help >> + > > This blank line can be deleted. > I will remove it. Thank you, Zhen! eric >> + 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 KEXEC_SIG >> + help >> + This option makes kernel signature verification mandatory for >> + the kexec_file_load() syscall. >> + >> +config KEXEC_BZIMAGE_VERIFY_SIG >> + bool "Enable bzImage signature verification support" >> + 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 KEXEC && HIBERNATION >> + depends on ARCH_HAS_KEXEC_JUMP >> + 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_HAS_CRASH_DUMP >> + select KEXEC_CORE >> + select CRASH_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> >> + >> +endmenu >> >
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