RE: [RFC] x86_64: A real proposal for iret-less return to kernel

[Luck, Tony]

>> That TIF_MCE_NOTIFY prevents the return to user mode, and we end up in mce_notify_process().
>
> Why is this necessary?

The recovery path has to do more than just send a signal - it needs to walk processes and
"mm"s to see which have mapped the physical address that the h/w told us has gone bad.

-Tony