Re: Linux 6.11-rc1

[Guenter Roeck <linux@roeck-us.net>]

On 7/30/24 12:38, Peter Zijlstra wrote:
> On Tue, Jul 30, 2024 at 01:31:18PM -0600, Jens Axboe wrote:
>> On 7/30/24 1:22 PM, Peter Zijlstra wrote:
>>> On Tue, Jul 30, 2024 at 11:53:31AM -0700, Linus Torvalds wrote:
>>>
>>>> Which makes me think it's asm_exc_int3 just recursively failing.
>>>
>>> Sounds like text_poke() going sideways, there's a jump_label fail out
>>> there:
>>>
>>>   https://lkml.kernel.org/r/20240730132626.GV26599@noisy.programming.kicks-ass.net
>>
>> No change with this applied...
>>
>> Also not sure if you read my link, but a few things to note:
>>
>> - It only happens with gcc-11 here. I tried 12/13/14 and those
>>    are fine, don't have anything older
> 
> One of my test boxes has 4.4 4.6 4.8 4.9 5 6 8 9 10 11 12 13
> 
> (now I gotta go figure out wth 7 went :-) And yeah, we don't support
> most of those version anymore (phew).
> 
> So if its easy to setup, I could try older GCCs.
> 
>> - It only happens with KFENCE enabled.
> 
> I missed the KFENCE bit. Happen to have the .config handy, I couldn't
> make much sense of Gunther's website in a hurry.
> 

An interesting bit of information: The problem is seen with many,
but not all CPUs. For example, I don't see it with athlon, n270, Dhyana,
or EPYC. qemu32 is affected, but qemu64 is fine. But on the other side
both kvm32 and kvm64 are affected.

Guenter