Re: [LKP] [x86] 811565123a: BUG: kernel hang in early-boot stage, last printk: Probing EDD (edd=off to disable)... ok

From: Ye Xiaolong
Date: Fri Oct 14 2016 - 00:56:50 EST

On 10/14, Ye Xiaolong wrote:
>On 10/13, Andi Kleen wrote:
>>Andi Kleen <andi@xxxxxxxxxxxxxx> writes:
>>Any comments on this?
>>I still cannot reproduce the failure unfortunately.
>Btw, you can try below commands to reproduce the error on your local
>host, they will download the necessary images and run QEMU:
> git clone git://
> cd lkp-tests
> bin/lkp qemu -k KERNEL job-script # job-script is attached in the original report email

Results show this hang may be related to gcc version, with gcc version
4.8.4 (Ubuntu 4.8.4-2ubuntu1~14.04.3), kernel could boot without early
hang, but if kernel was built with gcc version 6.2.0 20160901 (Debian
6.2.0-3), it will stuck in the early stage:

early console in setup code
Probing EDD (edd=off to disable)... ok

gdb output as below:

$ gdb -ex "target remote localhost:1234" vmlinux
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Reading symbols from vmlinux...done.
Remote debugging using localhost:1234
0x048a34d9 in ?? ()
(gdb) bt
#0 0x048a34d9 in ?? ()
#1 0x00000000 in ?? ()

>>> Could you do two tests for me:
>>> - Enable CONFIG_MICROCODE_INTEL and see if it boots then
>>> - Add CONFIG_DEBUG_INFO to the config.
>>> Add -s to the qemu command line and boot again. Then when it hangs
>>> connect gdb to see where it hangs
>>> gdb -ex "target remote localhost:1234" vmlinux
>>> bt
>>> <show output>
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