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

From	Tony Luck <tony.luck@gmail.com>
Newsgroups	linux.kernel
Subject	Re: [PATCH v8 1/3] x86: Expand exception table to allow new handling options
Date	2016-01-10 02:20 +0100
Message-ID	<qPcPM-5pB-5@gated-at.bofh.it> (permalink)
References	(2 earlier) <qOQYV-6P7-1@gated-at.bofh.it> <qP5Oi-od-3@gated-at.bofh.it> <qP67D-KN-3@gated-at.bofh.it> <qP7Q7-1LE-29@gated-at.bofh.it> <qPakW-3yt-7@gated-at.bofh.it>
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On Sat, Jan 9, 2016 at 2:32 PM, Andy Lutomirski <luto@amacapital.net> wrote:
> Step 1: determine that the HW context is, in principle, recoverable.
>
> Step 2: ask the handler to try to recover.
>
> Step 3: if the handler doesn't recover, panic
>
> I'm not saying that restructuring the code like this should be a
> prerequisite for merging this, but I'm wondering whether it would make
> sense at some point in the future.

For the local machine check case this all looks simple. For the broadcast
case it's pretty incompatible with the current code structure. For a machine
check triggered someplace in the kernel w/o a new style fixup handler we'd
start by saying ... "sure, that's plausible to recover from". Then after we let
all the other CPUs return from the machine check handler we'd take it
back and say "just kidding, we're going down". It might work, but it would
be a messier panic than we have now.

Definitely food for thought for some future cleanups.

-Tony

Thread

[PATCH v8 0/3] Machine check recovery when kernel accesses poison Tony Luck <tony.luck@intel.com> - 2016-01-09 01:20 +0100
  [PATCH v8 1/3] x86: Expand exception table to allow new handling  options Tony Luck <tony.luck@intel.com> - 2016-01-09 01:20 +0100
    Re: [PATCH v8 1/3] x86: Expand exception table to allow new handling options Andy Lutomirski <luto@amacapital.net> - 2016-01-09 03:00 +0100
      Re: [PATCH v8 1/3] x86: Expand exception table to allow new handling options Brian Gerst <brgerst@gmail.com> - 2016-01-09 04:50 +0100
        Re: [PATCH v8 1/3] x86: Expand exception table to allow new handling options Brian Gerst <brgerst@gmail.com> - 2016-01-09 05:40 +0100
          Re: [PATCH v8 1/3] x86: Expand exception table to allow new handling options Andy Lutomirski <luto@amacapital.net> - 2016-01-09 07:40 +0100
            Re: [PATCH v8 1/3] x86: Expand exception table to allow new handling options Brian Gerst <brgerst@gmail.com> - 2016-01-12 00:10 +0100
              Re: [PATCH v8 1/3] x86: Expand exception table to allow new handling options Andy Lutomirski <luto@amacapital.net> - 2016-01-12 00:30 +0100
              RE: [PATCH v8 1/3] x86: Expand exception table to allow new  handling options "Luck, Tony" <tony.luck@intel.com> - 2016-01-12 00:50 +0100
      Re: [PATCH v8 1/3] x86: Expand exception table to allow new handling options Tony Luck <tony.luck@gmail.com> - 2016-01-09 18:50 +0100
        Re: [PATCH v8 1/3] x86: Expand exception table to allow new handling options Andy Lutomirski <luto@amacapital.net> - 2016-01-09 19:10 +0100
          Re: [PATCH v8 1/3] x86: Expand exception table to allow new handling options Tony Luck <tony.luck@gmail.com> - 2016-01-09 21:00 +0100
            Re: [PATCH v8 1/3] x86: Expand exception table to allow new handling options Andy Lutomirski <luto@amacapital.net> - 2016-01-09 23:40 +0100
              Re: [PATCH v8 1/3] x86: Expand exception table to allow new handling options Tony Luck <tony.luck@gmail.com> - 2016-01-10 02:20 +0100
      Re: [PATCH v8 1/3] x86: Expand exception table to allow new handling  options "Luck, Tony" <tony.luck@intel.com> - 2016-01-11 01:30 +0100
  [PATCH v8 2/3] x86, mce: Check for faults tagged in  EXTABLE_CLASS_FAULT exception table entries Tony Luck <tony.luck@intel.com> - 2016-01-09 01:20 +0100

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