tests linux: do not skip tests depending on kernel <= 6.8

[Marcondiro]

Description

The Linux images used in CI use kernel 6.11, and headers are mostly >=6.8 at the time of writing, the only exceptions begin 32 bit architectures which are still on old headers due to the 32 -> 64 bit time_t enforcement in newer images.

Remove the tests requiring a kernel <= 6.8 from the skipped ones for 64 bit images not using musl.

Bump x86 32 images since x86 won't get the 64 bits time_t.

Sources

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Checklist

• Relevant tests in libc-test/semver have been updated
• No placeholder or unstable values like *LAST or *MAX are
  included (see #3131)
• Tested locally (cd libc-test && cargo test --target mytarget);
  especially relevant for platforms that may not be checked in CI

[tgross35]

I think we're stuck to the host (ubuntu-24.04) kernel versions here since Docker doesn't bring its own kernel. Per https://en.wikipedia.org/wiki/Ubuntu_version_history#Table_of_versions that means 6.8.

[Marcondiro]

Hi, @tgross35, according to CI logs this is the image currently used https://github.com/actions/runner-images/releases/tag/ubuntu24%2F20260111.209

Kernel Version: 6.11.0-1018-azure

[tgross35]

Huh, nice find. Any idea what the issue is then - does the version of the installed headers not match up?

[Marcondiro]

I haven't finished checking all the errors, but so far I found a couple of wrong constants (see issue #4935 and my other PR #4936). Once done I will mark this as, ready. Any help on this is welcome 😁

[Marcondiro]

Some tests on __c_anonymous_xsk_tx_metadata_union and its variants are failing.

Discusison #4940 was opened to understand how to address this. Should we
A- rename the variants (xsk_tx_metadata_request, xsk_tx_metadata_completion) adding the prefix or
B- explicitly skip the variants from CI?

[tgross35]

I'd love to do this for all the 32-bit linux targets, any reason why it's only i686 here?

[Marcondiro]

I tried to do the same for armhf but it was failing due tothe transition to 64 bit time.
Looking around I found a Debian page about the transition towards 64 bit time where they say that x86 ABI wont change while arm got the ABI update. So, the # FIXME here is indeed correct for 32 bit architectures excluding x86.

[tgross35]

Oh, so x86-32 didn't actually do the 64-bit time_t update yet? If so then this makes sense.

[Marcondiro]

Yep, correct. As far as I understood, Debian x86 32 will never get the 64 bit time_t.
Since they no longer provide x86 ISOs, the x86 32 stuff is there mainly for retrocompatibility so they preferred to keep it as is.

[tgross35]

Oh that's right, I did hear about that for Debian. In that case I think this is probably close to ready if you want to mark it ready for review.