Re: linux-next: Tree for Jul 10 (arch/s390/kernel/machine_kexec_file.c)

[Eric DeVolder]

On 7/10/23 17:15, Randy Dunlap wrote:
> On 7/10/23 14:27, Eric DeVolder wrote:
> > On 7/10/23 15:23, Eric DeVolder wrote:
> > > On 7/10/23 15:11, Randy Dunlap wrote:
> > > > On 7/9/23 18:38, Stephen Rothwell wrote:
> > > > > Hi all,
> > > > >
> > > > > Changes since 20230707:
> > > >
> > > > on s390:
> > > >
> > > > ../arch/s390/kernel/machine_kexec_file.c: In function 's390_verify_sig':
> > > > ../arch/s390/kernel/machine_kexec_file.c:69:15: error: implicit declaration of function 'verify_pkcs7_signature' [-Werror=implicit-function-declaration]
> > > >      69 |         ret = verify_pkcs7_signature(kernel, kernel_len,
> > > >         |               ^~~~~~~~~~~~~~~~~~~~~~
> > > > cc1: some warnings being treated as errors
> > > >
> > > >
> > > > Full randconfig file is attached.
> > >
> > > Randy,
> > > Thanks for this. This appears to be randconfig testing against linux-next.
> > > As of right now, linux-next does not contain the v5 that I posted friday.
> > > The v5 posted friday was picked up by Andrew and over the weekend no fails
> > > discovered, and the series currently sits in mm-everything branch. So hopefully
> > > it will appear soon in linux-next!
> > >
> > > Let me know if I misunderstand the situation.
> > > Thanks!
> > > eric
> >
> > Well the root cause is a missing SYSTEM_DATA_VERIFICATION. This was discussed
> > through MODULE_SIG_FORMAT thread. I don't think v5 changed anything with
> > respect to this issue, so it will likely reveal itself again.
> >
> > Since it was agreed to drop MODULE_SIG_FORMAT, and my attempt to select
> > SYSTEM_DATA_VERIFICATION results in same circular dependency as with
> > MODULE_SIG_FORMAT, I'm unsure how to proceed.
> >
> > The arch/s390/Kconfig S390 option has a 'select KEXEC' (but not KEXEC_FILE),
> > maybe we consider adding a 'select SYSTEM_DATA_VERIFICATION' as well?
>
> Sure, since some other configs select it also.
> And as long as it doesn't cause a circular dependency problem.
>
> thanks.

Randy, all,
I did the following for s390 and it "works", but I don't think we can use it.

Changed:

config ARCH_SUPPORTS_KEXEC_FILE
    def_bool CRYPTO && CRYPTO_SHA256 && CRYPTO_SHA256_S390

to:

config ARCH_SELECTS_KEXEC_FILE
        def_bool y
        depends on KEXEC_FILE
        select CRYPTO
        select CRYPTO_SHA256
        select CRYPTO_SHA256_S390
        select SYSTEM_DATA_VERIFICATION

and this essentially passes my regression but for the following:

FAIL olddefconfig arch/s390/configs/defconfig
LHSB {'CONFIG_CRYPTO_SHA256_S390': 'm'}
RHSB {'CONFIG_CRYPTO_SHA256_S390': 'y'}

which simply means that the CRYPTO_SHA256_S390 is always built-in, whereas previously
it could be a module. This happens because 'select' is always =y; overwrites if
previously =m, as was the case with this particular config file.

I still don't know how to close this gap. Today I see linux-next has v5 in it.
eric