Xorg segfaults on start-up on Big Endian PPC hardware

Bug #1581076 reported by Alex Perez on 2016-05-12
20
This bug affects 3 people
Affects Status Importance Assigned to Milestone
xorg-server (Ubuntu)
Undecided
Timo Aaltonen
Xenial
Undecided
Unassigned
xorg-server-lts-xenial (Ubuntu)
Undecided
Unassigned
Trusty
Undecided
Unassigned
Xenial
Undecided
Unassigned

Bug Description

On my Big Endian PowerPC machine, Xorg segfaults when starting. I have been able to confirm that this does not happen when building Xorg from upstream source, and then further confirmed that the source of the segfault appears to be caused by a non-upstreamed, ubuntu specific patch.

When building the xorg-server-1.18.3 deb from source, I commented out the following patches from debian/patches/series to try to isolate the source of the crash. With the following patches not-applied, and the resulting .deb package built, the segfault on start does not occur.

08_xfree86_fix_ia64_inx_outx.diff
105_nvidia_autodetect.patch
168_glibc_trace_to_stderr.patch
188_default_primary_to_first_busid.patch
190_cache-xkbcomp_output_for_fast_start_up.patch
191-Xorg-add-an-extra-module-path.patch
232-xf86compatoutput-valgrind.patch
no-nv.patch
228_autobind_gpu.patch
xf86-inactive-gpuscreen.patch
config-add-no-removal.patch
xf86-ignore-conflicting-rr-caps.patch
fix-detach-gpu.patch
disable-rotation-transform-gpuscreens.patch
xmir.patch
xmir-desktop-file-hint-flag.patch
drm_device_keep_trying.patch
xi2-resize-touch.patch
xmir-fixes.diff

Alex Perez (aperez-6) on 2016-05-12
description: updated
Timo Aaltonen (tjaalton) on 2016-05-12
affects: xorg (Ubuntu) → xorg-server (Ubuntu)
Timo Aaltonen (tjaalton) wrote :

you need to bisect the patches to find out what breaks

Changed in xorg-server (Ubuntu):
status: New → Incomplete
Alex Perez (aperez-6) wrote :

Timo, I have done so and narrowed it down to the following patch: 188_default_primary_to_first_busid.patch

Can we conditionally NOT apply this to powerpc?

Alex Perez (aperez-6) wrote :

Correction, Timo, I have definitively traced this down to drm_device_keep_trying.patch. 188_default_primary_to_first_busid.patch is not the offending patch.

Alex Perez (aperez-6) wrote :

Ping. Can we please get this ticket out of incomplete state?

Launchpad Janitor (janitor) wrote :

[Expired for xorg-server (Ubuntu) because there has been no activity for 60 days.]

Changed in xorg-server (Ubuntu):
status: Incomplete → Expired
Timo Aaltonen (tjaalton) wrote :

Sorry for the delay, and thanks for the bisect. I'll modify the patch so that it's not used on non-x86. I'll drop it completely from y+1.

Changed in xorg-server (Ubuntu):
assignee: nobody → Timo Aaltonen (tjaalton)
status: Expired → In Progress
Timo Aaltonen (tjaalton) wrote :

actually I'll just drop it from yakkety and think about what to do with xenial...

Alex Perez (aperez-6) wrote :

Thank you, this is very much appreciated.

Launchpad Janitor (janitor) wrote :

This bug was fixed in the package xorg-server - 2:1.18.4-1ubuntu5

---------------
xorg-server (2:1.18.4-1ubuntu5) yakkety; urgency=medium

  * drm_device_keep_trying.patch: Dropped, shouldn't be needed anymore, and
    causes issues on non-x86 archs. (LP: #1581076)

 -- Timo Aaltonen <email address hidden> Fri, 02 Sep 2016 13:59:52 +0300

Changed in xorg-server (Ubuntu):
status: In Progress → Fix Released
Launchpad Janitor (janitor) wrote :

Status changed to 'Confirmed' because the bug affects multiple users.

Changed in xorg-server (Ubuntu Xenial):
status: New → Confirmed
Brian Murray (brian-murray) wrote :

How can we test to be sure drm_device_keep_trying.patch is no longer needed or watch for regressions if it really is needed?

Timo Aaltonen (tjaalton) wrote :

A subtantially larger portion of users are now using SSD's, so if there was a race condition still in yakkety we'd probably know about it by now. But there is no other test than keep rebooting to check if the login manager comes up each time.

It's fine by me to keep the patch in the lts-xenial backport though, since trusty is still on upstart which might've played a part in this.

Hello Alex, or anyone else affected,

Accepted xorg-server into xenial-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/xorg-server/2:1.18.4-0ubuntu0.1 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested, and change the tag from verification-needed to verification-done. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed. In either case, details of your testing will help us make a better decision.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance!

Changed in xorg-server (Ubuntu Xenial):
status: Confirmed → Fix Committed
tags: added: verification-needed
Alex Perez (aperez-6) wrote :

Hi Andy,

Thanks very much. We will certainly test this ASAP once it lands in proposed, and report back.

Alex Perez (aperez-6) wrote :

I see that the build has completed successfully. I manually fetched and installed https://launchpad.net/ubuntu/+source/xorg-server/2:1.18.4-0ubuntu0.1/+build/10751236/+files/xserver-xorg-core_1.18.4-0ubuntu0.1_powerpc.deb , and Xorg came to life as expected, without the segfault.

tags: added: verification-done
removed: verification-needed
Launchpad Janitor (janitor) wrote :

This bug was fixed in the package xorg-server - 2:1.18.4-0ubuntu0.1

---------------
xorg-server (2:1.18.4-0ubuntu0.1) xenial; urgency=medium

  * New upstream bugfix release. (LP: #1619142)
  * randr-adjust-masters-last-set-time.diff,
    randr-do-not-check-the-screen-size.diff:
    Fix issues changing display mode on prime setups. (LP: #1586260)
  * os-treat-ssh-as-a-non-local-client.diff: Dropped, upstream.
  * drm_device_keep_trying.patch: Dropped, shouldn't be needed anymore,
    and causes issues on non-x86 archs. (LP: #1581076)
  * debian/patches/xmir.patch: backport XMir fixes from Ubuntu "Yakkety Yak"
    - fix button/menu focus failures (lp: #1590553)
    - ignore 'unnkown 11 event' (lp: #1617925)
    - don't call epoxy every frame (lp: #1617932)
    - fix unclickable parts of the screen after rotation (lp: #1613708)
    - fix key repeat issues (lp: #1591356)

 -- Timo Aaltonen <email address hidden> Thu, 01 Sep 2016 10:28:26 +0300

Changed in xorg-server (Ubuntu Xenial):
status: Fix Committed → Fix Released

The verification of the Stable Release Update for xorg-server has completed successfully and the package has now been released to -updates. Subsequently, the Ubuntu Stable Release Updates Team is being unsubscribed and will not receive messages about this bug report. In the event that you encounter a regression using the package from -updates please report a new bug using ubuntu-bug and tag the bug report regression-update so we can easily find any regressions.

Hello Alex, or anyone else affected,

Accepted xorg-server-lts-xenial into trusty-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/xorg-server-lts-xenial/2:1.18.4-0ubuntu0.2~trusty1 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation on how to enable and use -proposed.Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested, and change the tag from verification-needed to verification-done. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed. In either case, details of your testing will help us make a better decision.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance!

tags: removed: verification-done
tags: added: verification-needed
Timo Aaltonen (tjaalton) on 2017-01-11
Changed in xorg-server-lts-xenial (Ubuntu Xenial):
status: New → Invalid
Brian Murray (brian-murray) wrote :

Hello Alex, or anyone else affected,

Accepted xorg-server-lts-xenial into trusty-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/xorg-server-lts-xenial/2:1.18.4-0ubuntu0.2~trusty2 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation on how to enable and use -proposed.Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested, and change the tag from verification-needed to verification-done. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed. In either case, details of your testing will help us make a better decision.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance!

Changed in xorg-server-lts-xenial (Ubuntu Trusty):
status: New → Fix Committed
Launchpad Janitor (janitor) wrote :

Status changed to 'Confirmed' because the bug affects multiple users.

Changed in xorg-server-lts-xenial (Ubuntu):
status: New → Confirmed
Alex Perez (aperez-6) wrote :

patch fixes the bug

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