mjhjmtu

The last time I needed to deal with kernel headers was back in the Pleistocene (2.6 or so) and I remember back then that you needed to match your kernel headers not to the kernel you were running but to the kernel version glibc was compiled against. But this was a long time ago and before the kernel exported its own headers.

I have a computer that will be running a 4.15 series kernel, with a C library compiled against 4.4 series headers. Should I export the headers from the kernel I'm running, or use the headers package that my distro (Slackware) provides? (Or, and please say the answer is no, do I need to also rebuild glibc against the new kernel?)

I have an old Slackware server running a 4.6 kernel instead of its original 3.10 and have not had to mess with the headers. I've built at least a dozen kernels for half a dozen Slackware versions over the years and never did anything about headers or glibc on any of those.

Of course, without the newer headers, you may not be able to build software which uses features from that new kernel. But I doubt you'd be running Slackware if you wanted bleeding edge software so I don't think you'll run into that issue.