On Thu, Aug 14, 2025 at 02:08:57PM +0100, Mark Brown wrote:

On Thu, Aug 14, 2025 at 02:59:13PM +0200, David Hildenbrand wrote:

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On 14.08.25 14:09, Mark Brown wrote:

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Perhaps this is something that needs considering in the ABI, so
userspace can reasonably figure out if it failed to configure whatever
is being configured due to a missing feature (in which case it should
fall back to not using that feature somehow) or due to it messing
something else up?  We might be happy with the tests being version
specific but general userspace should be able to be a bit more robust.

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Yeah, the whole prctl() ship has sailed, unfortunately :(

Perhaps a second call or sysfs file or something that returns the
supported mask?  You'd still have a boostrapping issue with existing
versions but at least at any newer stuff would be helped.

Ack yeah I do wish we had better APIs for expressing what was
available/not. Will put this sort of thing on the TODO...

Overall I don't want to hold this up unnecesarily, and I bow to the
consensus if others feel we ought not to _assume_ same kernel at least best
effort.

Usama - It's ok to leave it as is in this case since obviously only tip
kernel will have this feature.

Cheers, Lorenzo