FS#76681 - [linux] trace_printk() being used warning from Linux

Attached to Project: Arch Linux
Opened by Yassine Oudjana (Tooniis) - Sunday, 27 November 2022, 08:53 GMT
Last edited by Toolybird (Toolybird) - Monday, 28 August 2023, 21:02 GMT
Task Type Bug Report
Category Packages: Core
Status Closed
Assigned To No-one
Architecture x86_64
Severity High
Priority Normal
Reported Version
Due in Version Undecided
Due Date Undecided
Percent Complete 100%
Votes 0
Private No



This has been appearing in dmesg since at least linux 6.0.9:

[ 7.661903] **********************************************************
[ 7.661907] ** **
[ 7.661909] ** trace_printk() being used. Allocating extra memory. **
[ 7.661911] ** **
[ 7.661913] ** This means that this is a DEBUG kernel and it is **
[ 7.661915] ** unsafe for production use. **
[ 7.661916] ** **
[ 7.661918] ** If you see this message and you are not debugging **
[ 7.661920] ** the kernel, report this immediately to your vendor! **
[ 7.661922] ** **
[ 7.661925] **********************************************************

Additional info:
* package version(s): 6.0.9.arch1-1, 6.0.10.arch2-1

Steps to reproduce:
- Check dmesg
This task depends upon

Closed by  Toolybird (Toolybird)
Monday, 28 August 2023, 21:02 GMT
Reason for closing:  Upstream
Additional comments about closing:  If still happening with latest kernels, please follow up with upstream kernel folks.
Comment by loqs (loqs) - Sunday, 27 November 2022, 19:33 GMT
Please post the full output of dmesg and lsmod. If possible could you work through older kernel releases to find which release introduced the issue?
Comment by Toolybird (Toolybird) - Monday, 28 November 2022, 01:19 GMT
This is most likely caused by 3rd party modules. It's come up before  FS#56363   FS#57076 .
Comment by Yassine Oudjana (Tooniis) - Monday, 28 November 2022, 11:21 GMT
I went all the way back to 5.15 and it's happening there too. I don't know if it's worth the time to keep going back further. I don't believe I have any out-of-tree modules installed, unless I picked one up as a dependency of some package or in some other indirect way without noticing. Attached dmesg and lsmod concatenated into one file.

I should say that I noticed this while trying to figure out some issue with the backlight control, which stopped working after upgrading to 6.0.10. Downgrading the kernel back to 6.0.5 where it was working didn't fix it. This is the only lead to the issue I could find in dmesg:

[ 3.062041] i915 0000:00:02.0: [drm] *ERROR* Failed to get the SoC PWM chip

Could this random breakage be related in anyway or is it likely just a coincidence?
   dmesg (73.8 KiB)
Comment by loqs (loqs) - Monday, 28 November 2022, 13:54 GMT
If you blacklist [1] the atomisp module [2] is the message still produced? If it is try blacklisting the atomisp-isp2 module.

[1] https://wiki.archlinux.org/title/Kernel_module#Using_kernel_command_line_2
[2] https://lore.kernel.org/all/20211028124217.394cc49b%40sal.lan/
Comment by loqs (loqs) - Tuesday, 29 November 2022, 23:02 GMT
[1] Reports after blacklisting the atomisp module the message is no longer produced. From [2] upstream is aware of the issue.

[1] https://bbs.archlinux.org/viewtopic.php?pid=2070789#p2070789
[2] https://lore.kernel.org/all/20211028124217.394cc49b%40sal.lan/
Comment by Toolybird (Toolybird) - Wednesday, 30 November 2022, 07:06 GMT
Once again, thank you @loqs for your investigation. So it seems like an in-tree module behaving badly. IIUC, not much Arch can do here until upstream fixes it. Will leave this ticket open so we can track progress.
Comment by Yassine Oudjana (Tooniis) - Wednesday, 30 November 2022, 11:01 GMT
Yes, it no longer appears after blacklisting atomisp.