Injecting SLB miltihit crashes kernel 5.9.0-rc5

[Michael Ellerman]

Michal Suchánek <msuchanek at suse.de> writes:
> Hello,
>
> Using the SLB mutihit injection test module (which I did not write so I
> do not want to post it here) to verify updates on my 5.3 frankernekernel
> I found that the kernel crashes with Oops: kernel bad access.
>
> I tested on latest upstream kernel build that I have at hand and the
> result is te same (minus the message - nothing was logged and the kernel
> simply rebooted).

That's disappointing.

> Since the whole effort to write a real mode MCE handler was supposed to
> prevent this maybe the SLB injection module should be added to the
> kernel selftests?

Yes I'd like to see it upstream. I think it should be integrated into
LKDTM, which contains other dangerous things like that and is designed
for testing how the kernel handles/recovers from bad conditions.

cheers