Re: [PATCH v1 01/21] kexec: consolidate kexec and crash options into kernel/Kconfig.kexec
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
Re: [PATCH v1 01/21] kexec: consolidate kexec and crash options into kernel/Kconfig.kexec
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!
Re: [PATCH v1 01/21] kexec: consolidate kexec and crash options into kernel/Kconfig.kexec
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_ config options. Architectures can utilize the new ARCH_SUPPORTS_ config options to specify additional components when is enabled. To summarize, the ARCH_HAS_ permits the to be enabled, and the ARCH_SUPPORTS_ handles side effects (ie. select statements). Signed-off-by: Eric DeVolder --- 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 ..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
Re: [PATCH v1 01/21] kexec: consolidate kexec and crash options into kernel/Kconfig.kexec
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_ config options. > > Architectures can utilize the new ARCH_SUPPORTS_ config > options to specify additional components when is enabled. > > To summarize, the ARCH_HAS_ permits the to be > enabled, and the ARCH_SUPPORTS_ handles side effects (ie. > select statements). > > Signed-off-by: Eric DeVolder > --- > 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 ..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 bzImag