Re: Linux 6.11-rc1

From: Guenter Roeck
Date: Tue Jul 30 2024 - 16:24:48 EST


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