On 02/09/26 at 02:33pm, Alexander Egorenkov wrote:
> The commit c8424e776b09 ("MODSIGN: Export module signature definitions")
> replaced the dependency of KEXEC_SIG on SYSTEM_DATA_VERIFICATION with
> the dependency on MODULE_SIG_FORMAT. This change disables KEXEC_SIG
> in s390 kernels built with MODULES=n if nothing else selects
> MODULE_SIG_FORMAT.
>
> Furthermore, the signature verification in s390 kexec does not require
> MODULE_SIG_FORMAT because it requires only the struct module_signature and,
> therefore, does not depend on code in kernel/module_signature.c.
>
> But making ARCH_SUPPORTS_KEXEC_SIG depend on SYSTEM_DATA_VERIFICATION
> is also incorrect because it makes KEXEC_SIG available on s390 only
> if some other arbitrary option (for instance a file system or device driver)
> selects it directly or indirectly.
>
> To properly make KEXEC_SIG available for s390 kernels built with MODULES=y
> as well as MODULES=n _and_ also not depend on arbitrary options selecting
> SYSTEM_DATA_VERIFICATION, we set ARCH_SUPPORTS_KEXEC_SIG=y for s390 and
> select SYSTEM_DATA_VERIFICATION when KEXEC_SIG=y.
Thanks for fixing the issue.
Seems the background and change is a little twisting, and selecting
SYSTEM_DATA_VERIFICATION will cause a bunch of verification feature
selected. While the change is only s390 related, request s390 expert to
have look at this change. If no concern from s390 developer, I am also
fine to it.
Thanks
Baoquan
>
> Fixes: c8424e776b09 ("MODSIGN: Export module signature definitions")
> Signed-off-by: Alexander Egorenkov <[email protected]>
> ---
> arch/s390/Kconfig | 2 +-
> kernel/Kconfig.kexec | 1 +
> 2 files changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
> index c2c7bf974397..385c1052cf45 100644
> --- a/arch/s390/Kconfig
> +++ b/arch/s390/Kconfig
> @@ -313,7 +313,7 @@ config ARCH_SUPPORTS_KEXEC_FILE
> def_bool y
>
> config ARCH_SUPPORTS_KEXEC_SIG
> - def_bool MODULE_SIG_FORMAT
> + def_bool y
>
> config ARCH_SUPPORTS_KEXEC_PURGATORY
> def_bool y
> diff --git a/kernel/Kconfig.kexec b/kernel/Kconfig.kexec
> index 15632358bcf7..df97227cfca9 100644
> --- a/kernel/Kconfig.kexec
> +++ b/kernel/Kconfig.kexec
> @@ -50,6 +50,7 @@ config KEXEC_SIG
> bool "Verify kernel signature during kexec_file_load() syscall"
> depends on ARCH_SUPPORTS_KEXEC_SIG
> depends on KEXEC_FILE
> + select SYSTEM_DATA_VERIFICATION if S390
> 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
> --
> 2.51.0
>
