kobject: tried to init an uninitialized object when removing and re-inserting sd-mod

Bug #263746 reported by Danilo Piazzalunga
2
Affects Status Importance Assigned to Milestone
linux (Ubuntu)
Invalid
Undecided
Unassigned

Bug Description

I downloaded the Intrepid Alternate Install CD daily image (2008-09-01) and I booted a machine to perform a clean install after re-partitioning the disks and doing some testing/experimenting.

Unusual things happened when I unloaded the module sd-mod (modprobe -r sd-mod): the disks powered down -- but I guess this was ok. Then, when I reloaded the module (modprobe sd-mod), I got some oopses and a kernel panic. The bug was reproducible after a reboot, and I saved the syslog.

Steps to reproduce:
* Boot from the Intrepid Alternate Install CD
* At partman's stage, Go Back and then switch to a console/open a shell
* modprobe -v -r sd-mod:
  rmmod /lib/modules/2.6.27-2-generic/kernel/drivers/scsi/sd_mod.ko
  rmmod /lib/modules/2.6.27-2-generic/kernel/lib/crc-t10dif.ko

The usual noise made by the disk(s) powering down will be heard.

* modprobe -v sd-mod
  insmod /lib/modules/2.6.27-2-generic/kernel/lib/crc-t10dif.ko
  insmod /lib/modules/2.6.27-2-generic/kernel/drivers/scsi/sd_mod.ko

The kernel will print "kobject (f736d29c): tried to init an initialized object, something is seriously wrong." and a stack trace. Possibly, it will produce an oops and panic.

Revision history for this message
Danilo Piazzalunga (danilopiazza) wrote :
Revision history for this message
Danilo Piazzalunga (danilopiazza) wrote :

I was able to save only the first snippet of the kernel messages (from /proc/kmsg) before the kernel panicked.

Revision history for this message
Danilo Piazzalunga (danilopiazza) wrote :

Just some background info: this machine has got two SATA hard disks and a VIA chipset.
And another observation: if I unload the SATA module too (sata-via), nothing bad happens when I reload sata-via/sd-mod: the disks simply power on again and the kernel is perfectly happy.

Revision history for this message
kernel-janitor (kernel-janitor) wrote :

Hi Danilo,

This bug was reported a while ago and there hasn't been any activity in it recently. We were wondering if this is still an issue? Can you try with the latest development release of Ubuntu? ISO CD images are available from http://cdimage.ubuntu.com/releases/ .

If it remains an issue, could you run the following command from a Terminal (Applications->Accessories->Terminal). It will automatically gather and attach updated debug information to this report.

apport-collect -p linux 263746

Also, if you could test the latest upstream kernel available that would be great. It will allow additional upstream developers to examine the issue. Refer to https://wiki.ubuntu.com/KernelMainlineBuilds . Once you've tested the upstream kernel, please remove the 'needs-upstream-testing' tag. This can be done by clicking on the yellow pencil icon next to the tag located at the bottom of the bug description and deleting the 'needs-upstream-testing' text. Please let us know your results.

Thanks in advance.

[This is an automated message. Apologies if it has reached you inappropriately; please just reply to this message indicating so.]

tags: added: needs-kernel-logs
tags: added: needs-upstream-testing
tags: added: kj-triage
Changed in linux (Ubuntu):
status: New → Incomplete
Revision history for this message
Danilo Piazzalunga (danilopiazza) wrote :

I cannot reproduce this with the latest development release (Karmic Alpha 3) because support for SCSI disks (CONFIG_BLK_DEV_SD) is built in the kernel and not as a module.

Revision history for this message
Leann Ogasawara (leannogasawara) wrote :

Closing this for now based on the previous comment. Thanks.

Changed in linux (Ubuntu):
status: Incomplete → Invalid
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