Re: [PATCH v5 4/9] x86/traps: Enable all exception handler callbacks early

From: Andy Lutomirski
Date: Mon Apr 04 2016 - 11:48:11 EST


On Sun, Apr 3, 2016 at 7:10 AM, Borislav Petkov <bp@xxxxxxxxx> wrote:
> On Sun, Apr 03, 2016 at 06:55:00AM -0700, Andy Lutomirski wrote:
>> > No, please don't fail at early boot.
>> >
>> > Early boot is just about the *worst* situation to try to debug odd
>> > failures, exactly since things like printk may not be reliable, and
>> > things won't get logged etc.
>> >
>> > So particularly during early boot we should try as hard as possible
>> > not to crash - even if it means not being able to log about a problem.
>> > At least that way you have a hopefully working machine and can *maybe*
>> > debug things.
>> >
>>
>> In this regard, at least, my patch is the right approach. Calling the
>> handler, whatever it is, is less likely to panic than refusing to call
>> it.
>
> Ok, good.
>
> But can we pretty please document this whole situation, i.e., the
> fact that we're trying really really hard not to fail early boot for
> debuggability reasons - either in the commit message or better in the
> code, for future reference. I think this is an important aspect to hold
> down.

I emailed out a followup patch to add a comment.

--Andy

>
> Thanks.
>
> --
> Regards/Gruss,
> Boris.
>
> ECO tip #101: Trim your mails when you reply.



--
Andy Lutomirski
AMA Capital Management, LLC