[gentoo-dev] glibc 2.16/19 for Gentoo Prefix on antique kernels

[Benda Xu]

Hi all,

Yes, it's 2018.  But there are still RHEL 4 and 5 systems running
antique kernels such as 2.6.8 and 2.6.18.  In my experience, many of
them are data acquisition hubs or computing clusters.  No administrator
cares about security as long as they "work".

Under the form "Prefix", Gentoo is set out to rescue users trapped in
these abandoned wastelands of antiques.  After years of work, we have
achieved that goal, except one minor thing: glibc periodically drop
support for old linux kernels, the lastest glibc supporting linux 2.6.8
is 2.16 and for linux-2.6.18 it is glibc-2.19.

With the recent reunion of the Toolchain Project, old glibc versions are
masked and removed, accelerating the adoption of new versions.  This
opens a new oppotunity for the Prefix: people stops caring about
unsupported glibc versions, the Prefix Project can take them over
without worrying about breaking other peoples' machines.

Now, profiles/default/linux/amd64/17.0/no-multilib/prefix/kernel-2.6.16+
unmasks <glibc-2.18. Some pathes needs to be backported, like the
/lib/gentoo/functions.sh transition.  prefix/kernel-2.6+ with glibc-2.16
is also planned.  In addition, glibc have to be patched to get python3
built[1-3], which is urgent once portage drops python2[4].


So I would like to hear what you guys think if I:

  - keep glibc-2.19 and glibc-2.16 in tree and unmasking them in the
    selected Prefix profiles;
     
  - maintain those selected outdated glibc versions on the
    infrastructure of the Toolchain Project[5];

  - (optional) add an exception to the toolchain support policy[6].

Thanks and cheers!
Benda

1. https://bugs.python.org/issue28092
2. https://bugs.python.org/issue31255
3. https://bugs.python.org/issue29157
4. https://archives.gentoo.org/gentoo-project/message/7eb61502d827476a9326b0f180dbd2fa
5. https://wiki.gentoo.org/wiki/Project:Toolchain/Patchsets_with_Git
6. https://wiki.gentoo.org/wiki/Project:Toolchain/Support_policies