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

From	Andy Lutomirski <luto@amacapital.net>
Newsgroups	linux.kernel
Subject	Re: [PATCH v5 4/9] x86/traps: Enable all exception handler callbacks early
Date	2016-04-03 16:00 +0200
Message-ID	<rjQJk-44U-15@gated-at.bofh.it> (permalink)
References	(2 earlier) <rjyW6-81e-9@gated-at.bofh.it> <rjAbv-IR-1@gated-at.bofh.it> <rjAOe-Z0-1@gated-at.bofh.it> <rjLgB-tH-3@gated-at.bofh.it> <rjQJk-44U-7@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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On Sun, Apr 3, 2016 at 6:51 AM, Linus Torvalds
<torvalds@linux-foundation.org> wrote:
> On Sun, Apr 3, 2016 at 3:07 AM, Borislav Petkov <bp@alien8.de> wrote:
>>
>> I'm wondering whether making it try to EFAULT correctly is the right
>> thing to do... We're certainly more conservative if we panic and not
>> allow some silently failed attempt at recovery which looks successful,
>> to continue.
>
> 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.

--Andy

Thread

[PATCH v5 4/9] x86/traps: Enable all exception handler callbacks early Andy Lutomirski <luto@kernel.org> - 2016-04-02 16:10 +0200
  Re: [PATCH v5 4/9] x86/traps: Enable all exception handler callbacks  early Borislav Petkov <bp@alien8.de> - 2016-04-02 21:00 +0200
    Re: [PATCH v5 4/9] x86/traps: Enable all exception handler callbacks early Andy Lutomirski <luto@amacapital.net> - 2016-04-02 22:20 +0200
      Re: [PATCH v5 4/9] x86/traps: Enable all exception handler callbacks  early Borislav Petkov <bp@alien8.de> - 2016-04-02 23:00 +0200
        Re: [PATCH v5 4/9] x86/traps: Enable all exception handler callbacks  early Borislav Petkov <bp@alien8.de> - 2016-04-03 10:10 +0200
          Re: [PATCH v5 4/9] x86/traps: Enable all exception handler callbacks early Andy Lutomirski <luto@amacapital.net> - 2016-04-03 15:30 +0200
          Re: [PATCH v5 4/9] x86/traps: Enable all exception handler callbacks early Linus Torvalds <torvalds@linux-foundation.org> - 2016-04-03 16:00 +0200
            Re: [PATCH v5 4/9] x86/traps: Enable all exception handler callbacks early Andy Lutomirski <luto@amacapital.net> - 2016-04-03 16:00 +0200
              Re: [PATCH v5 4/9] x86/traps: Enable all exception handler callbacks early Linus Torvalds <torvalds@linux-foundation.org> - 2016-04-03 16:20 +0200
              Re: [PATCH v5 4/9] x86/traps: Enable all exception handler callbacks  early Borislav Petkov <bp@alien8.de> - 2016-04-03 16:20 +0200
                Re: [PATCH v5 4/9] x86/traps: Enable all exception handler callbacks early Andy Lutomirski <luto@amacapital.net> - 2016-04-04 17:50 +0200
  [tip:x86/asm] x86/traps: Enable all exception handler callbacks  early tip-bot for Andy Lutomirski <tipbot@zytor.com> - 2016-04-13 13:50 +0200

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