18:02 <misha354> Can anyone help me debug this systemtap error? missing unwind/symbol data for module 'kernel', on Ubuntu 14.04 with kernel patched to version 4.4.0-133?

18:24 <fche> hi misha354

18:24 <misha354> hi!

18:24 <fche> stap should give a hint like [man SOMETHING], which is a suggestion to run man SOMETHING

18:25 <fche> but basically for some stap scripts, especially including backtrace/symbol type operations, stap needs access to the kernel image vmlinux that matches the target (running) one

18:27 <misha354> Thank you, is there a way to ensure that?

18:28 <misha354> Here is my full output https://gist.github.corp.dyndns.com/mzhukovskiy/cc46bd3ca9926a69737cc3ff2134a66f

18:30 <fche> hm, I think that's a private url

18:30 <misha354> oh, woops

18:30 <misha354> https://gist.github.com/misha354/d32054dd3067ea2838598716525b287f

18:31 <fche> ok, the WARNING message is not your problem

18:31 <fche> your problem is that the kernel is considerably newer than the version of systemtap you're using

18:31 <fche> stap -V ?

18:32 <misha354> Systemtap translator/driver (version 2.3/0.158, Debian version 2.3-1ubuntu1.4 (trusty)) Copyright (C) 2005-2013 Red Hat, Inc. and others This is free software; see the source for copying conditions. enabled features: AVAHI LIBSQLITE3 NSS TR1_UNORDERED_MAP NLS

18:33 <misha354> that makes sense, I patched the kernel, but am still using the Trusty package repositories

18:33 <fche> yeah, so it's old enough that it doesn't tell you the range of kernel versions it's able to work with

18:33 <fche> [13:23:30] % stap -V

18:33 <fche> Systemtap translator/driver (version 4.0/0.174, rpm 4.0-2.fc29)

18:33 <fche> Copyright (C) 2005-2018 Red Hat, Inc. and others

18:33 <fche> This is free software; see the source for copying conditions.

18:33 <fche> tested kernel versions: 2.6.18 ... 4.19-rc7

18:33 <fche> enabled features: AVAHI BOOST_STRING_REF DYNINST BPF JAVA PYTHON3 LIBRPM LIBSQLITE3 LIBVIRT LIBXML2 NLS NSS READLINE

18:33 <fche> ^^^ on fedora 29 e.g.

18:33 <fche> so consider building a newer one perhaps

18:33 <misha354> Thank you, that is definitely something to go on. I will try either installing from a different repository or building from source

18:33 <fche> or maybe someone has a PPA with a newer build

18:34 <fche> btw: see the

18:34 <fche> Pass 4: compilation failed. [man error::pass4]

18:34 <fche> at the bottom

18:34 <fche> man error::pass4 ought to give useful advice

18:34 <fche> but I gather the debian packager folks split off the man pages so you may need apt-get install systemtap-doc or such

18:35 <misha354> indeed

18:36 <misha354> thanks a lot for your help!

18:36 <fche> my pleasure

18:36 <fche> sorry it's not Just Working out of the box

18:36 <fche> unfortunately the kernel folks refuse to have anything like a fixed api let alone abi, so out-of-tree modules have to play catchup constantly

18:37 <fche> and in this case, you were given a five-year-old laggard :)