"sudo strace -p $(pgrep X)" hangs system after a few seconds

[Daniel Hahler]

I've tried "sudo strace -p $(pgrep X)" in a KDE konsole to see what Xorg was doing that may cause high cpu load.

After a few seconds and lot of output, the system hung and I could not switch to another VT, but music kept playing in the background.
Doing the REISUB sequence, the system restartet after Alt-SysRq-R or -E already.
This was reproducible (I've tried it twice), the restart however appeared only once: it required a hard reset the other time.

This is probably related to the generated output, since it did not happen on VT1 after reboot, where I've used "-o outputfile" though.

Using "sudo strace -p $(pgrep X) -o /tmp/1" and "tail -f /tmp/1" also does not cause the hangup.

ProblemType: Bug
Architecture: i386
Date: Sun Mar 7 04:06:46 2010
DistroRelease: Ubuntu 10.04
Lsusb:
 Bus 002 Device 004: ID 045e:00db Microsoft Corp. Natural Ergonomic Keyboard 4000 V1.0
 Bus 002 Device 002: ID 1a7c:0068
 Bus 002 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
 Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
NonfreeKernelModules: nvidia
Package: xserver-xorg-core 2:1.7.5-1ubuntu2
ProcCmdLine: root=UUID=73d091ef-8ee9-4ad2-9243-1ece878c1024 resume=/dev/fastrcvg/swaplv ro acpi_use_timer_override usbcore.autosuspend=1 splash
ProcEnviron:
 LANGUAGE=
 PATH=(custom, user)
 LANG=de_DE.UTF-8
 SHELL=/bin/bash
ProcVersionSignature: Ubuntu 2.6.32-15.22-generic
SourcePackage: xorg-server
Uname: Linux 2.6.32-15-generic i686
dmi.bios.date: 03/08/2007
dmi.bios.vendor: Award Software International, Inc.
dmi.bios.version: F9c
dmi.board.name: NF-CK804
dmi.board.vendor: Gigabyte Technology Co., Ltd.
dmi.board.version: x.x
dmi.chassis.type: 3
dmi.modalias: dmi:bvnAwardSoftwareInternational,Inc.:bvrF9c:bd03/08/2007:svn:pn:pvr:rvnGigabyteTechnologyCo.,Ltd.:rnNF-CK804:rvrx.x:cvn:ct3:cvr:
system:
 distro: Ubuntu
 codename: lucidarchitecture: i686kernel: 2.6.32-15-generic

[Daniel Hahler (blueyed)]

I've just tried reproducing it in a virtualbox guest on Windows, but it kept running for ~1 minute without problems.
I will retry it on my Ubuntu machine at home later.

[penalvch (penalvch)]

Daniel Hahler, reproducible on a Trusty host with a Trusty guest as noted in the Bug Description. I'm aware the advised method of debugging xorg problems is via gdb -> https://wiki.ubuntu.com/X/Backtracing . However, this may not be preferred for folks who are used to utilizing strace.

[Paul White (paulw2u)]

We are sorry that we do not always have the capacity to review all reported bugs in a timely manner. You reported this bug some time ago and there have been many changes in Ubuntu since that time.

Ubuntu 14.04 (trusty) reached end-of-standard-support on April 25, 2019.

Do you still see a problem related to the one that you reported when using a currently supported version of Ubuntu? Please let us know if you do otherwise this report can be left to expire in approximately 60 days time.

Thank you for helping make Ubuntu better.

[Launchpad Janitor (janitor)]

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