Unable to handle kernel NULL pointer dereference in ppdev module
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
linux (Ubuntu) |
Fix Released
|
Medium
|
Lee Jones | ||
Lucid |
Fix Released
|
Undecided
|
Unassigned | ||
Maverick |
Fix Released
|
Medium
|
Lee Jones | ||
linux-fsl-imx51 (Ubuntu) |
Invalid
|
Undecided
|
Unassigned | ||
Lucid |
Fix Released
|
Undecided
|
Unassigned | ||
Maverick |
Invalid
|
Undecided
|
Unassigned | ||
linux-mvl-dove (Ubuntu) |
Fix Released
|
Medium
|
Eric Miao | ||
Lucid |
Fix Released
|
Undecided
|
Unassigned | ||
Maverick |
Fix Released
|
Medium
|
Eric Miao | ||
linux-ti-omap4 (Ubuntu) |
Fix Released
|
Medium
|
Lee Jones | ||
Lucid |
Invalid
|
Undecided
|
Unassigned | ||
Maverick |
Fix Released
|
Medium
|
Lee Jones |
Bug Description
During boot on a Beagleboard with latest image, the system attempts to load the parallel port drivers (no ports exist on this system), which in turn causes the driver to fail with an oops message and kernel dump (see dmesg log).
ProblemType: Bug
DistroRelease: Ubuntu 10.10
Package: linux-image-omap 2.6.35.6.7
Regression: Yes
Reproducible: Yes
ProcVersionSign
Uname: Linux 2.6.35-6-omap armv7l
AlsaVersion: Advanced Linux Sound Architecture Driver Version 1.0.23.
AplayDevices:
**** List of PLAYBACK Hardware Devices ****
card 0: omap3beagle [omap3beagle], device 0: TWL4030 twl4030-0 []
Subdevices: 1/1
Subdevice #0: subdevice #0
Architecture: armel
ArecordDevices:
**** List of CAPTURE Hardware Devices ****
card 0: omap3beagle [omap3beagle], device 0: TWL4030 twl4030-0 []
Subdevices: 1/1
Subdevice #0: subdevice #0
Date: Fri Jul 2 16:06:43 2010
Lspci:
Error: command ['lspci', '-vvnn'] failed with exit code 1: pcilib: Cannot open /proc/bus/pci
lspci: Cannot find any working access method.
Lsusb:
Bus 001 Device 004: ID 05d5:6781 Super Gate Technology Co., Ltd
Bus 001 Device 003: ID 07a6:8511 ADMtek, Inc. ADM8511 Pegasus II Ethernet
Bus 001 Device 002: ID 05e3:0608 Genesys Logic, Inc. USB-2.0 4-Port HUB
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
ProcCmdLine: vram=12M omapfb.
ProcEnviron:
SHELL=/bin/bash
LANG=en_US.utf8
SourcePackage: linux
affects: | linux (Ubuntu) → linux-ti-omap (Ubuntu) |
Changed in linux-ti-omap4 (Ubuntu Maverick): | |
milestone: | none → maverick-alpha-3 |
Changed in linux-ti-omap (Ubuntu Maverick): | |
milestone: | none → maverick-alpha-3 |
Changed in linux-ti-omap4 (Ubuntu Maverick): | |
assignee: | nobody → Lee Jones (lag) |
importance: | Undecided → Medium |
status: | New → Triaged |
Changed in linux-ti-omap (Ubuntu Maverick): | |
assignee: | nobody → Lee Jones (lag) |
importance: | Undecided → Medium |
status: | New → Triaged |
Changed in linux-ti-omap (Ubuntu Maverick): | |
status: | Triaged → In Progress |
Changed in linux-ti-omap4 (Ubuntu Maverick): | |
status: | Triaged → In Progress |
Changed in linux-ti-omap4 (Ubuntu Maverick): | |
status: | In Progress → Fix Released |
Changed in linux-mvl-dove (Ubuntu Maverick): | |
assignee: | nobody → Eric Miao (eric.y.miao) |
importance: | Undecided → Medium |
milestone: | none → maverick-updates |
Changed in linux-fsl-imx51 (Ubuntu Maverick): | |
status: | New → Invalid |
Changed in linux-fsl-imx51 (Ubuntu): | |
status: | New → Invalid |
Changed in linux-fsl-imx51 (Ubuntu Lucid): | |
status: | New → In Progress |
Changed in linux (Ubuntu Lucid): | |
status: | New → Fix Released |
Changed in linux-mvl-dove (Ubuntu Lucid): | |
status: | New → Fix Released |
Changed in linux-ti-omap4 (Ubuntu Lucid): | |
status: | New → Invalid |
Through some slow, extensive testing, I have been able to reproduce this bug on Lucid with kernel 2.6.33-502-omap by typing " sudo modprobe parport_pc" in a console. When looking at the differences between 2.6.33 and 2.6.35 kernels, I noticed ppdev was added (probably in 2.6.34) recently. While this module doesn't appear to depend on parport_pc, I have yet to figure out why parport_pc is loaded in the new image.
Adding "blacklist parport_pc" to /etc/modules. d/blacklist. conf seems to eliminate the problem, in that the system no longer tries to load that module. Not sure if this is a proper fix, but it is an easy one. The other solution is a fix from the upstream kernel, and I have not been able to find a bug report upstream yet (connection issues with kerneloops.org).