Re: [PATCH v8 1/3] x86: Expand exception table to allow new handling options

From: Tony Luck
Date: Sat Jan 09 2016 - 12:46:37 EST


On Fri, Jan 8, 2016 at 5:52 PM, Andy Lutomirski <luto@xxxxxxxxxxxxxx> wrote:
> Also, I think it would be nicer if the machine check code would invoke
> the handler regardless of which handler (or class) is selected. Then
> the handlers that don't want to handle #MC can just reject them.

The machine check code is currently a two pass process.

First we scan all the machine check banks (on all processors
at the moment because machine checks are broadcast). We
assess the severity of all errors found.

Then we take action. Panic if the most severe error was fatal,
recover if not.

This patch series tweaks the severity calculation. In-kernel
errors at IPs with a EXTABLE_CLASS_FAULT handler are
now ranked as recoverable. All other kernel errors remain
fatal.

I don't think it is right to unconditionally execute the fix code in the
severity assessment phase.

Perhaps later we can revisit the two pass process?

-Tony