RE: [PATCH v2] mm: hwpoison: coredump: support recovery from dump_user_range()

[Luck, Tony]

> > This change seems to not related to what you try to fix.
> > Could this break some other workloads like copying from user address?
> > 
> 
> Yes, this move MCE_IN_KERNEL_COPYIN set into next case, both COPY and
> MCE_SAFE type will set MCE_IN_KERNEL_COPYIN, for EX_TYPE_COPY, we don't
> break it.

Should Linux even try to take a core dump for a SIGBUS generated because
the application accessed a poisoned page?

It doesn't seem like it would be useful. Core dumps are for debugging s/w
program errors in applications and libraries. That isn't the case when there
is a poison consumption. The application did nothing wrong.

This patch is still useful though. There may be an undiscovered poison
page in the application. Avoiding a kernel crash when dumping core
is still a good thing.

-Tony