Re: Linux 6.11-rc1

[Guenter Roeck]

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@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
> >
> > 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