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

From: Klara Modin
Date: Tue Sep 10 2024 - 05:41:55 EST


On 2024-09-10 11:39, Klara Modin wrote:
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@xxxxxxxxx

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@xxxxxxxxx>

Sorry, this should now be from my usual email.