Re: WARNING: kernel stack frame pointer at ffffffff82e03f40 in swapper:0 has bad value (null)

From: Borislav Petkov
Date: Sat Dec 10 2016 - 12:28:19 EST


On Sat, Dec 10, 2016 at 11:04:44AM -0600, Josh Poimboeuf wrote:
> That's a new one. Was there anything else printed?

It is the first line that appears in dmesg when I boot:

[ 0.000000] WARNING: kernel stack frame pointer at ffffffffb5e03f40 in swapper:0 has bad value (null)
[ 0.000000] Linux version 4.9.0-rc8+ (boris@gondor) (gcc version 6.2.0 20161109 (Debian 6.2.0-13) ) #1 SMP PREEMPT Sat Dec 10 13:25:29 CET 2016
[ 0.000000] Command line: BOOT_IMAGE=/boot/vmlinuz-4.9.0-rc8+ root=/dev/sda7 ro earlyprintk=ttyS0,115200 console=ttyS0,115200 console=tty0 root=/dev/sda7 log_buf_len=10M resume=/dev/sda5 no_console_suspend ignore_loglevel
[ 0.000000] KERNEL supported cpus:
[ 0.000000] Intel GenuineIntel
[ 0.000000] AMD AuthenticAMD
[ 0.000000] Centaur CentaurHauls
[ 0.000000] x86/fpu: Supporting XSAVE feature 0x001: 'x87 floating point registers'
...

> Were you doing anything special when it happened?

Not really - just booting ;-)

> Do you see it reliably?

2 of 2 boots.

> I should probably figure out a way to dump more data for that warning.

Sure, I can test patches.

Thanks.

--
Regards/Gruss,
Boris.

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