Bug#783259: linux-image-3.16.0-4-amd64: Indicating ABI changes from upstream

[Jon Bernard <jbernard@debian.org>]

Package: src:linux
Version: 3.16.7-ckt9-2
Severity: normal

In looking into the cause of a recent build failure in the
lttng-modules-dkms package, I noticed that an incompatible ABI change
was made at some point.  The kmem.h header differs from the upstream
3.16.7 version. Specifically, the signature for 'trace_mm_page_alloc_extfrag'.

This is fine, if we could have a way to distinguish between upstream
3.16.7 and our version.  It appears that Ubuntu kernels introduce
a UTS_UBUNTU_RELEASE_ABI into their kernels, which can be used to follow
their own kernel versions.  Could we perhaps do the same?

Without the ability to do conditionals comparing numeric values both in
Makefiles and within C, I am not sure how tell the two different kernels
apart, and therefore am rather stuck.

-- 
Jon