OOPS in latest kernel

[dave-p]

oops.txt

This is on an original Pi2B running fully up-to-date Arch Linux. The application is TVHeadend which was compiled from source on this machine and which uses a DVB-S2 USB stick. Networking is via Ethernet.

The OOPS is triggered when I stream live TV from TVHeadend to VLC (v3.0) running on a remote Linux machine, then close the session by exiting VLC. TVHeadend becomes unresponsive and cannot be killed.

Reverting the kernel and firmware to the previous version cures the problem.

The same behaviour is seen if the SD card is moved to a Pi3B.

[dave-p]

To clarify, the last good kernel (that I can test without building my own) is 4.14.24, commit 80a14a5. The oldest failing kernel is 4.14.26, commit ad350a5.
I know nothing of kernel internals but this commit, introduced in 4.14.25, looks possibly relevant: abb4a8b

[popcornmix]

Are you able to build a kernel with that commit reverted?
https://www.raspberrypi.org/documentation/linux/kernel/building.md

[dave-p]

Working on it now, but I may be some time...

[lategoodbye]

According to netdev this patch should be the fix.

[dave-p]

I built a kernel from the head of the rpi-4.14 branch using the Arch packaging system; as expected the Oops occurs.
Reverting commit abb4a8b and rebuilding, the issue is gone.
Reinstating abb4a8b and also applying the patch from https://www.spinics.net/lists/netdev/msg489445.html, the issue is still gone.

[popcornmix]

Okay, looks like an upstream bug with a pending upstream fix.
Once it is merged we can pull it in here (hopefully it will appear in 4.14.28 or shortly afterwards) but if not we can pull it in earlier.

[dave-p]

Thanks.
@lategoodbye, many thanks for spotting the solution. I'll carry on using my homebrewed kernel until the fix comes through the system.

[popcornmix]

The linked patch has been pushed to linux tree and is in latest rpi-update kernel