On 1/14/22 08:30, Johnny Hughes wrote:
On 1/14/22 07:57, Gionatan Danti wrote:
Il 2022-01-14 13:17 Josh Boyer ha scritto:
RHEL's kernel live patching uses upstream open source kpatch. The
sources to the kpatches are delivered in customer facing CDN repos at
the same time as the kpatch itself. We do not use proprietary code to
produce or apply the kpatches.
I can only speculate on whether RHEL kpatches would work on a CentOS
kernel, but my assumption is that they would not due to how they are
signed.
Is (well, was) the CentOS kernel identical at binary level to the RHEL
one?
If so, the same kpatch should be applicable to both RHEL and CentOS
(the old one).
But I seem to understand that the two kernels are *not* bytewise
identical, so a binary kpatch can not be applied the CentOS. Is this
true?
Anyway, RH kpatches are surely not compatible with CentOS stream. So I
asked if some project was started to provide live kernel patching to
the new CentOS project. If I don't miss something, this is not the case.
Regards.
No .. none of the CentOS Kernels were EVER binary compatible with any
RHEL kernel.
CentOS Linux has always been (now also including CentOS Stream 8 and 9)
a completely separate 'closed' build system.
We use the SAME source code to build things, modified to remove
branding. But CentOS has NEVER been (nor is any other rebuild
distribution now) Binary Compatible.
Want to see how .. just extract two rpms with the same name from two
different distributions into separate directories and run a sha256sum on
all the files in the different directories with find command. Some
files may be identical (most text files that are copied), others will
not be.
It is virtually impossible for all produced packages to be 'binary
compatible' UNLESS they are built with exact the same files (not files
BUILT fromt he same sources .. the exact same files) in the build root
AND with exactly the same software doing the building. Any group that
claims 'binary compatibility' is either lying or they do not understand
compiling and linking.
CentOS never had that. Neither does any rebuild.
This is why the CentOS Project 'CHANGED' our term from binary compatible
to 'Functionally Compatible' a long time ago. (Using same source code,
we produce DIFFERENT software .. that works the same way but has
different SHASUM values. Don't be fooled by key words like 'binary
compatible' .. check it out for yourself.
If you build kpatches to kernels, to make them work you need to build
the kpatch for the specific kernel (CentOS would need to build against
CentOS kernels, etc). Also, there are the certificate signing issues
and keys that you would need to take into account. You need to have the
CA Trust to be able to create signatures that the system will allow.
_______________________________________________
As a bit of a helper .. we used to use this script to find differences:
https://vault.centos.org/4.9/build/distro/tmverifyrpms
Way back in the CentOS Linux 4 days.
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