New way for syncing with kernel headers

[Florian Weimer]

On 12/08/2017 08:49 PM, Jonathan Nieder wrote:

> - I don't see any uses of LINUX_VERSION_CODE in glibc today except in
>    the configure script.  Is there a reason to prefer
>    __LINUX_KERNEL_VERSION instead (maybe for a more stable namespace,
>    even in contexts where namespace polution is not an issue)?

We need something which is defined in an UAPI header today.

__LINUX_KERNEL_VERSION is an internal glibc macro for a different 
purpose: it indicates the minimum (assumed) kernel version.

> - I'd worry about the LINUX_VERSION_CODE < 4.14 case bitrotting.  Is
>    there an easy way to ensure it gets test-compiled e.g. as part of
>    build-many-glibcs?

Easy is relative: Build with older kernel headers.

Thanks,
Florian