Re: [tip:locking/urgent] [jump_label] de752774f3: kernel_BUG_at_arch/x86/kernel/jump_label.c

[Klara Modin <klara@kasm.eu>]

Hi,

On 2024-09-09 12:56, Peter Zijlstra wrote:
> On Mon, Sep 09, 2024 at 11:15:31AM +0200, Peter Zijlstra wrote:
>> On Sun, Sep 08, 2024 at 09:06:55PM +0800, kernel test robot wrote:
>>>
>>>
>>> Hello,
>>>
>>> kernel test robot noticed "kernel_BUG_at_arch/x86/kernel/jump_label.c" on:
>>>
>>> commit: de752774f38bb766941ed1bf910ba5a9f6cc6bf7 ("jump_label: Fix static_key_slow_dec() yet again")
>>> https://git.kernel.org/cgit/linux/kernel/git/tip/tip.git locking/urgent
>>>
>>> in testcase: boot
>>>
>>> compiler: clang-18
>>> test machine: qemu-system-x86_64 -enable-kvm -cpu SandyBridge -smp 2 -m 16G
>>>
>>
>>> The kernel config and materials to reproduce are available at:
>>> https://download.01.org/0day-ci/archive/20240908/202409082005.393050e2-oliver.sang@intel.com
>>
>> So the whole thing actually boots and works on my real machine, so I had
>> to resort to using this qemu nonsense, as such I did as instructed in
>> the reproduce file.
>>
>> I build the thing using clang-17 (for some reason debian is shitting
>> itself trying to install clang-18 on this machine and I don't want to
>> spend the day fighting that).
>>
>> Except, once I do:
>>
>>    bin/lkp qemu -k /usr/src/linux-2.6/tmp-build/arch/x86/boot/bzImage -m /usr/src/linux-2.6/tmp-build/mod/modules.cgz job-script
>>
>> The whole thing grinds to a halt like so:
> 
> Since I'm not able to reproduce, could you please run the thing against:
> 
>    git://git.kernel.org/pub/scm/linux/kernel/git/peterz/queue.git locking/urgent
> 
> and see what that does?
> 

I hit this bug on today's next. Reverting 
de752774f38bb766941ed1bf910ba5a9f6cc6bf7 and applying the updated 
version (6b01e5a8c11611a3dbd3d9efd915427cbce9352a) fixed it for me.

Thanks,
Tested-by: Klara Modin <klarasmodin@gmail.com>