[SRU] Xorg crashes when performing gesture
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
xorg-server (Ubuntu) |
Invalid
|
High
|
Unassigned | ||
Maverick |
Fix Released
|
Undecided
|
Unassigned | ||
xserver-xorg-input-evdev (Ubuntu) |
Invalid
|
High
|
Unassigned | ||
Maverick |
Fix Released
|
Undecided
|
Unassigned |
Bug Description
Justification:
=============
Regression from Ubuntu 10.04, causing an Xserver crash after performing a gesture. The X crash risks losing user data from unsaved documents in applications.
Fix:
===
The cause is a call to WriteToClient in signal context during input event processing. The call was added for gesture event handling, but it appears that something in WriteToClient is unsafe in signal context. Patches have been added to xserver-
Note that the fix is not proposed for Natty because the gesture stack will be removed from Natty and moved to the X client side. The Natty gesture code will likely be removed in the next few weeks during the transition to X server 1.10.
Test case:
=========
Perform multitouch gestures in a gesture-enabled environment. The Unity window manager should suffice. However, this bug is indeterministic. Some users may never see the bug, others may see it multiple times per day.
Regression Potential:
=======
Moderate due to the changes to two interrelated packages and the size of the patches. A depends has been added to xserver-
The size of the patches may cause some concern, but they are the minimal amount required to address the bug in a maintainable manner.
Original Report:
===============
Binary package hint: xorg
I have X crashes a couple of times a day.
Could not reproduce it deterministically.
ProblemType: Bug
DistroRelease: Ubuntu 10.10
Package: xorg 1:7.5+6ubuntu3
ProcVersionSign
Uname: Linux 2.6.35-
NonfreeKernelMo
.proc.driver.
NVRM version: NVIDIA UNIX x86 Kernel Module 260.19.06 Mon Sep 13 06:35:06 PDT 2010
GCC version: gcc version 4.4.5 (Ubuntu/Linaro 4.4.4-14ubuntu5)
Architecture: i386
Date: Tue Nov 2 14:25:08 2010
InstallationMedia: Ubuntu 10.04.1 LTS "Lucid Lynx" - Release i386 (20100816.1)
MachineType: Apple Inc. MacBook5,1
ProcCmdLine: BOOT_IMAGE=
ProcEnviron:
LANGUAGE=en
LANG=en_US.utf8
SHELL=/bin/bash
SourcePackage: xorg
dmi.bios.date: 04/27/09
dmi.bios.vendor: Apple Inc.
dmi.bios.version: MB51.88Z.
dmi.board.
dmi.board.name: Mac-F42D89A9
dmi.board.vendor: Apple Inc.
dmi.board.version: Proto
dmi.chassis.
dmi.chassis.type: 10
dmi.chassis.vendor: Apple Inc.
dmi.chassis.
dmi.modalias: dmi:bvnAppleInc
dmi.product.name: MacBook5,1
dmi.product.
dmi.sys.vendor: Apple Inc.
system:
distro: Ubuntu
codename: maverick
architecture: i686
kernel: 2.6.35-
affects: | xorg (Ubuntu) → xorg-server (Ubuntu) |
Changed in xorg-server (Ubuntu): | |
importance: | Undecided → High |
Changed in xserver-xorg-input-evdev (Ubuntu): | |
importance: | Undecided → High |
Changed in xorg-server (Ubuntu): | |
status: | New → In Progress |
Changed in xserver-xorg-input-evdev (Ubuntu): | |
status: | New → In Progress |
description: | updated |
description: | updated |
description: | updated |
tags: | added: regression-release |
tags: |
added: verification-done removed: verification-needed |
Changed in xorg-server (Ubuntu): | |
status: | In Progress → Invalid |
For future reference, the core dump is generated from xserver- xorg-core= 2:1.9.0- 0ubuntu7.