[lttng-dev] Debian 3.16.7-ckt9-2 issue with lttng-modules kmem probe

[jbernard@debian.org (Jon Bernard)]

* Mathieu Desnoyers <mathieu.desnoyers at efficios.com> wrote:
> ----- Original Message -----
> > * Mathieu Desnoyers <mathieu.desnoyers at efficios.com> wrote:
> > > Hi Jon,
> > > 
> > > It appears that lttng-modules cannot build on the
> > > Debian kernel 3.16.0-4-amd64 #1 SMP Debian 3.16.7-ckt9-2 (2015-04-13)
> > > x86_64 GNU/Linux.
> > > 
> > > It appears that their exported kmem.h header differs from
> > > the upstream stable branch, but AFAIK there is no Debian-specific
> > > version number available to distinguish between upstream stable
> > > and the Debian kernel.
> > 
> > Indeed.  The only distinguishing characteristic I see is EXTRAVERSION
> > defined to '-ckt9'.  I haven't had a chance to try yet, but could that
> > be acceptable?
> 
> No, because we need to do conditionals comparing numeric values
> both in Makefiles and within C.
> 
> > 
> > > We have been hit by this in the past for Ubuntu kernels, and the
> > > solution has been to introduce a UTS_UBUNTU_RELEASE_ABI define
> > > into their kernels, which can be used to follow their own kernel
> > > versions.
> > > 
> > > Do you think we could ask Debian to do the same ?
> > 
> > I'm happy to ask, the argument is certainly sound.
> 
> Thanks!

No problem, bug filed: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=783259

There may be a workaround I can put into the debian package as
a short term fix, maybe a conditional patch depending on those differing
3.16 versions.  We'll see how the bug progresses and I'll keep you
posted.

-- 
Jon