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

[Jon Bernard]

* Jon Bernard <jbernard at debian.org> wrote:
> * 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.

Right, so I'll take a look at making a package update to resolve the
issue and get that into the stable archive so that lttng is again
working in the new release.

Sorry about this, it didn't occur to me that an API change would happen
and so I didn't continue testing 3.16 updates.  I'll get this sorted.

-- 
Jon