| Message ID | 20230706222027.189117-3-eric.devolder@oracle.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | refactor Kconfig to consolidate KEXEC and CRASH options | expand |
Le 07/07/2023 à 00:20, Eric DeVolder a écrit : > The kexec and crash kernel options are provided in the common > kernel/Kconfig.kexec. Utilize the common options and provide > the ARCH_SUPPORTS_ and ARCH_SELECTS_ entries to recreate the > equivalent set of KEXEC and CRASH options. Why do you need to duplicate the ARCH_SELECTS_ entries in each architecture ? Why not define them in arch/Kconfig then select if from each architecture ? For instance here for x86 for ARCH_SELECTS_KEXEC_FILE all you'll have to do is: select ARCH_SELECTS_KEXEC_FILE if KEXEC_FILE select HAVE_IMA_KEXEC if IMA && KEXEC_FILE Christophe > > Signed-off-by: Eric DeVolder <eric.devolder@oracle.com> > --- > arch/x86/Kconfig | 92 ++++++++++-------------------------------------- > 1 file changed, 19 insertions(+), 73 deletions(-) > > diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig > index 7422db409770..9767a343f7c2 100644 > --- a/arch/x86/Kconfig > +++ b/arch/x86/Kconfig > @@ -2040,88 +2040,34 @@ config EFI_RUNTIME_MAP > > source "kernel/Kconfig.hz" > > -config KEXEC > - bool "kexec system call" > - 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 "kexec file based system call" > - select KEXEC_CORE > - select HAVE_IMA_KEXEC if IMA > - depends on X86_64 > - depends on CRYPTO=y > - depends on CRYPTO_SHA256=y > - 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 ARCH_SUPPORTS_KEXEC > + def_bool y > > -config ARCH_HAS_KEXEC_PURGATORY > - def_bool KEXEC_FILE > +config ARCH_SUPPORTS_KEXEC_FILE > + def_bool X86_64 && CRYPTO && CRYPTO_SHA256 > > -config KEXEC_SIG > - bool "Verify kernel signature during kexec_file_load() syscall" > +config ARCH_SELECTS_KEXEC_FILE > + def_bool y > depends on KEXEC_FILE > - help > + select HAVE_IMA_KEXEC if IMA > > - 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. > +config ARCH_HAS_KEXEC_PURGATORY > + def_bool KEXEC_FILE > > - 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 ARCH_SUPPORTS_KEXEC_SIG > + def_bool y > > -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 ARCH_SUPPORTS_KEXEC_SIG_FORCE > + def_bool y > > -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 ARCH_SUPPORTS_KEXEC_BZIMAGE_VERIFY_SIG > + def_bool y > > -config CRASH_DUMP > - bool "kernel crash dumps" > - depends on X86_64 || (X86_32 && HIGHMEM) > - 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 > +config ARCH_SUPPORTS_KEXEC_JUMP > + def_bool y > > -config KEXEC_JUMP > - bool "kexec jump" > - depends on KEXEC && HIBERNATION > - help > - Jump between original kernel and kexeced kernel and invoke > - code in physical address mode via KEXEC > +config ARCH_SUPPORTS_CRASH_DUMP > + def_bool X86_64 || (X86_32 && HIGHMEM) > > config PHYSICAL_START > hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
On 7/7/23 00:58, Christophe Leroy wrote: > > > Le 07/07/2023 à 00:20, Eric DeVolder a écrit : >> The kexec and crash kernel options are provided in the common >> kernel/Kconfig.kexec. Utilize the common options and provide >> the ARCH_SUPPORTS_ and ARCH_SELECTS_ entries to recreate the >> equivalent set of KEXEC and CRASH options. > > > Why do you need to duplicate the ARCH_SELECTS_ entries in each > architecture ? > > Why not define them in arch/Kconfig then select if from each architecture ? > > For instance here for x86 for ARCH_SELECTS_KEXEC_FILE all you'll have to > do is: > select ARCH_SELECTS_KEXEC_FILE if KEXEC_FILE > select HAVE_IMA_KEXEC if IMA && KEXEC_FILE > > > Christophe Hi Christophe, thanks for looking at this! The ARCH_SELECTS_ is where the "customization" is performed for that option. The customization is putting in place the differences that the arch had from the common option. For example, with ARCH_SELECTS_KEXEC_FILE, here are all the uses: x86: select HAVE_IMA_KEXEC if IMA arm64: select HAVE_IMA_KEXEC if IMA powerpc: select KEXEC_ELF select HAVE_IMA_KEXEC if IMA riscv: select HAVE_IMA_KEXEC if IMA select KEXEC_ELF And there are archs (parisc, riscv, s390) that support KEXEC_FILE that do not need ARCH_SELECTS_KEXEC_FILE. So there isn't a clear path for optimizing the IMA statement, in this example, that I'm aware of. But perhaps I don't quite understand the technique you are suggesting, either... eric > >> >> Signed-off-by: Eric DeVolder <eric.devolder@oracle.com> >> --- >> arch/x86/Kconfig | 92 ++++++++++-------------------------------------- >> 1 file changed, 19 insertions(+), 73 deletions(-) >> >> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig >> index 7422db409770..9767a343f7c2 100644 >> --- a/arch/x86/Kconfig >> +++ b/arch/x86/Kconfig >> @@ -2040,88 +2040,34 @@ config EFI_RUNTIME_MAP >> >> source "kernel/Kconfig.hz" >> >> -config KEXEC >> - bool "kexec system call" >> - 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 "kexec file based system call" >> - select KEXEC_CORE >> - select HAVE_IMA_KEXEC if IMA >> - depends on X86_64 >> - depends on CRYPTO=y >> - depends on CRYPTO_SHA256=y >> - 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 ARCH_SUPPORTS_KEXEC >> + def_bool y >> >> -config ARCH_HAS_KEXEC_PURGATORY >> - def_bool KEXEC_FILE >> +config ARCH_SUPPORTS_KEXEC_FILE >> + def_bool X86_64 && CRYPTO && CRYPTO_SHA256 >> >> -config KEXEC_SIG >> - bool "Verify kernel signature during kexec_file_load() syscall" >> +config ARCH_SELECTS_KEXEC_FILE >> + def_bool y >> depends on KEXEC_FILE >> - help >> + select HAVE_IMA_KEXEC if IMA >> >> - 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. >> +config ARCH_HAS_KEXEC_PURGATORY >> + def_bool KEXEC_FILE >> >> - 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 ARCH_SUPPORTS_KEXEC_SIG >> + def_bool y >> >> -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 ARCH_SUPPORTS_KEXEC_SIG_FORCE >> + def_bool y >> >> -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 ARCH_SUPPORTS_KEXEC_BZIMAGE_VERIFY_SIG >> + def_bool y >> >> -config CRASH_DUMP >> - bool "kernel crash dumps" >> - depends on X86_64 || (X86_32 && HIGHMEM) >> - 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 >> +config ARCH_SUPPORTS_KEXEC_JUMP >> + def_bool y >> >> -config KEXEC_JUMP >> - bool "kexec jump" >> - depends on KEXEC && HIBERNATION >> - help >> - Jump between original kernel and kexeced kernel and invoke >> - code in physical address mode via KEXEC >> +config ARCH_SUPPORTS_CRASH_DUMP >> + def_bool X86_64 || (X86_32 && HIGHMEM) >> >> config PHYSICAL_START >> hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 7422db409770..9767a343f7c2 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -2040,88 +2040,34 @@ config EFI_RUNTIME_MAP source "kernel/Kconfig.hz" -config KEXEC - bool "kexec system call" - 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 "kexec file based system call" - select KEXEC_CORE - select HAVE_IMA_KEXEC if IMA - depends on X86_64 - depends on CRYPTO=y - depends on CRYPTO_SHA256=y - 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 ARCH_SUPPORTS_KEXEC + def_bool y -config ARCH_HAS_KEXEC_PURGATORY - def_bool KEXEC_FILE +config ARCH_SUPPORTS_KEXEC_FILE + def_bool X86_64 && CRYPTO && CRYPTO_SHA256 -config KEXEC_SIG - bool "Verify kernel signature during kexec_file_load() syscall" +config ARCH_SELECTS_KEXEC_FILE + def_bool y depends on KEXEC_FILE - help + select HAVE_IMA_KEXEC if IMA - 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. +config ARCH_HAS_KEXEC_PURGATORY + def_bool KEXEC_FILE - 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 ARCH_SUPPORTS_KEXEC_SIG + def_bool y -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 ARCH_SUPPORTS_KEXEC_SIG_FORCE + def_bool y -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 ARCH_SUPPORTS_KEXEC_BZIMAGE_VERIFY_SIG + def_bool y -config CRASH_DUMP - bool "kernel crash dumps" - depends on X86_64 || (X86_32 && HIGHMEM) - 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 +config ARCH_SUPPORTS_KEXEC_JUMP + def_bool y -config KEXEC_JUMP - bool "kexec jump" - depends on KEXEC && HIBERNATION - help - Jump between original kernel and kexeced kernel and invoke - code in physical address mode via KEXEC +config ARCH_SUPPORTS_CRASH_DUMP + def_bool X86_64 || (X86_32 && HIGHMEM) config PHYSICAL_START hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
The kexec and crash kernel options are provided in the common kernel/Kconfig.kexec. Utilize the common options and provide the ARCH_SUPPORTS_ and ARCH_SELECTS_ entries to recreate the equivalent set of KEXEC and CRASH options. Signed-off-by: Eric DeVolder <eric.devolder@oracle.com> --- arch/x86/Kconfig | 92 ++++++++++-------------------------------------- 1 file changed, 19 insertions(+), 73 deletions(-)