Bug 1461931 - Message from kernel about debug system calls in non-debug kernel
Message from kernel about debug system calls in non-debug kernel
Status: NEW
Product: Fedora
Classification: Fedora
Component: kernel (Show other bugs)
26
x86_64 Unspecified
unspecified Severity medium
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Assigned To: Kernel Maintainer List
Fedora Extras Quality Assurance
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Reported: 2017-06-15 12:02 EDT by George R. Goffe
Modified: 2017-08-01 15:21 EDT (History)
13 users (show)

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Description George R. Goffe 2017-06-15 12:02:03 EDT
Description of problem:
I was looking at dmesg just after boot and saw the message below.

Version-Release number of selected component (if applicable):
4.12.0-0.rc3.git0.2.fc27.x86_64

How reproducible:
always

Steps to Reproduce:
1.after reboot issue dmesg | less
2.
3.

Actual results:
see below

Expected results:
no message

Additional info:

[    0.000000] **********************************************************
[    0.000000] **   NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE   **
[    0.000000] **                                                      **
[    0.000000] ** trace_printk() being used. Allocating extra memory.  **
[    0.000000] **                                                      **
[    0.000000] ** This means that this is a DEBUG kernel and it is     **
[    0.000000] ** unsafe for production use.                           **
[    0.000000] **                                                      **
[    0.000000] ** If you see this message and you are not debugging    **
[    0.000000] ** the kernel, report this immediately to your vendor!  **
[    0.000000] **                                                      **
[    0.000000] **   NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE   **
[    0.000000] **********************************************************
Comment 1 Piero Finizio 2017-07-07 07:01:25 EDT
Same problem with kernel 4.12.0-1.fc27.x86_64.
Comment 2 Michael Chapman 2017-07-29 06:08:17 EDT
Also seen in kernel-4.12.4-300.fc26.x86_64, the current F26 updates-testing kernel.
Comment 3 Ted 2017-07-30 17:24:27 EDT
Also seen in kernel-4.12.4-300.fc26.x86_64, the current F26 NON testing kernel
Comment 4 Tomasz Torcz 2017-08-01 11:09:01 EDT
Rawhide kernels are supposed to have debug options enabled most of the time.

Stable kernel, not so much.
Comment 5 Justin M. Forbes 2017-08-01 12:49:40 EDT
Debug options are not turned on actually via the config, but a driver is calling trace_printk which is what causes this.  The solution is to turn off that driver.  Despite the scary warning, these are not full debug kernels.
Comment 6 George R. Goffe 2017-08-01 15:21:36 EDT
Hi,

The message isn't all that scary... The kernel's name doesn't have "debug" in it so the assumption is that it's not a debug kernel. I saw the msgs and wrote this bug for that reason... in an attempt to be helpful.

George...

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