Re: [tip:x86/mm] [x86/mm] 127960a055: WARNING:at_arch/x86/include/asm/kfence.h:#kfence_protect

[Peter Zijlstra]

On Sun, Nov 20, 2022 at 04:40:51PM +0800, kernel test robot wrote:
> 
> hi, PeterZ,
> 
> we noticed this is a fix for
> "[tip:x86/mm] [x86/mm]  b389949485: WARNING:at_arch/x86/mm/pat/set_memory.c:#__change_page_attr"
> we reported before on
> https://lore.kernel.org/all/202211061748.eb591682-oliver.sang@xxxxxxxxx/
> we noticed it brought below issue which is persistent in our tests. FYI
> 
> 
> Greeting,
> 
> FYI, we noticed WARNING:at_arch/x86/include/asm/kfence.h:#kfence_protect due to commit (built with gcc-11):
> 
> commit: 127960a05548ea699a95791669e8112552eb2452 ("x86/mm: Inhibit _PAGE_NX changes from cpa_process_alias()")
> https://git.kernel.org/cgit/linux/kernel/git/tip/tip.git x86/mm
> 
> in testcase: boot
> 
> on test machine: qemu-system-x86_64 -enable-kvm -cpu SandyBridge -smp 2 -m 16G
> 
> caused below changes (please refer to attached dmesg/kmsg for entire log/backtrace):
> 
> 
> +----------------------------------------------------------+------------+------------+
> |                                                          | 5ab815e377 | 127960a055 |
> +----------------------------------------------------------+------------+------------+
> | WARNING:at_arch/x86/include/asm/kfence.h:#kfence_protect | 0          | 15         |
> | RIP:kfence_protect                                       | 0          | 15         |
> | WARNING:at_mm/kfence/core.c:#kfence_protect              | 0          | 15         |
> +----------------------------------------------------------+------------+------------+
> 
> 
> If you fix the issue, kindly add following tag
> | Reported-by: kernel test robot <oliver.sang@xxxxxxxxx>
> | Link: https://lore.kernel.org/oe-lkp/202211201642.b65c9d2f-oliver.sang@xxxxxxxxx
> 
> 
> [    1.269844][    T0] ------------[ cut here ]------------
> [ 1.270843][ T0] WARNING: CPU: 0 PID: 0 at arch/x86/include/asm/kfence.h:46 kfence_protect (arch/x86/include/asm/kfence.h:46 mm/kfence/core.c:235) 

Should be fixed by:

  https://lkml.kernel.org/r/41ac24c4-6c95-d946-2679-c1be2cb20536@xxxxxxxxx

I think.