debcrafters-packages team mailing list archive

[Frank Heimes <2062118@xxxxxxxxxxxxxxxxxx>]

** Changed in: ubuntu-z-systems
       Status: In Progress => Fix Committed

-- 
You received this bug notification because you are a member of
Debcrafters packages, which is subscribed to libtraceevent in Ubuntu.
https://bugs.launchpad.net/bugs/2062118

Title:
  autopkgtests fail on s390x (segfault)

Status in Ubuntu on IBM z Systems:
  Fix Committed
Status in libtraceevent package in Ubuntu:
  Fix Released
Status in libtracefs package in Ubuntu:
  Fix Released
Status in libtraceevent source package in Noble:
  Fix Committed
Status in libtracefs source package in Noble:
  Confirmed
Status in libtraceevent source package in Oracular:
  Fix Committed
Status in libtracefs source package in Oracular:
  Confirmed
Status in libtraceevent source package in Plucky:
  Fix Released
Status in libtracefs source package in Plucky:
  Fix Released

Bug description:
  SRU Justification:

  [ Impact ]

   * This failure on s390x is primarily because tep_alloc sets file
     endianness to LITTLE_ENDIAN by default (with no checks)

   * The changes are already accepted into plucky and upstream:
     
  https://code.launchpad.net/~r41k0u/ubuntu/+source/libtraceevent/+git/libtraceevent/+merge/477042

   * This will fix autopkgtest segfaults of libtracefs on oracular and
  noble for s390x.

  [ Test Plan ]

   * Clone libtracefs (oracular-devel or noble-devel), compile it and
  make the tests (make && make test).

   * Then run the tests as root (utest/trace-utest), on an s390x machine
  (running oracular or noble)

   * You can test the fix by installing the patched version of
  libtraceevent for the release you are testing and trying the
  libtracefs tests again.

  [ Where problems could occur ]

   * This is not likely to break anything, as we can make a safe assumption
     to set file_bigendian to the same value as host_bigendian by default.
     If these are different, the user can set it using event-parse-api

   * In any case, this change seems logical. This does not affect any other
     (little-endian) architecture, and I think this won't be breaking any
     workarounds people did around this problem.

   * But in case we have some regressions as a result of this change,
     then there surely would be some workaround to this in a patch,
     which can then be reverted.

  [ Other Info ]

   * This does not fix anything in libtraceevent but does fix the tests
     for libtracefs on s390x.
     But I have opened this bug against libtraceevent.

   * I see a workaround for this problem in the last patch in d/p/series,
     but this change does not affect it
  __________

  As part of the added QA to libtracefs it was found that it triggers a segfault on s390x.
  This isn't just a test failing, it seems this is still deeply broken on s390x.

  Either way, while in the time pressure of the noble release the
  decision was simplified like "The tests didn't make it worse, just now
  we know" and continued (To not leave these platforms behind later
  unable to add it, albeit knowing it is still incomplete for now).

  It does not mean that we can ignore them for too long and certainly
  need to work on completing that into being fully functional in tests
  and real usage. Hence we create this spin off bug from the MIR work in
  bug 2051925 for tracking the further efforts.

  Example test log:
  https://autopkgtest.ubuntu.com/results/autopkgtest-noble/noble/s390x/libt/libtracefs/20240417_184123_8ab96@/log.gz

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu-z-systems/+bug/2062118/+subscriptions