All of lore.kernel.org
 help / color / mirror / Atom feed
From: Borislav Petkov <bp@alien8.de>
To: Andy Lutomirski <luto@amacapital.net>
Cc: "H. Peter Anvin" <hpa@linux.intel.com>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	X86 ML <x86@kernel.org>
Subject: Re: STI architectural question (and lretq -- I'm not even kidding)
Date: Wed, 23 Jul 2014 17:23:11 +0200	[thread overview]
Message-ID: <20140723152311.GC21707@pd.tnic> (raw)
In-Reply-To: <CALCETrVzKJZiEmxuVNv8_7dybh-4AQYRA5Yb5ms+vK9CKYEorA@mail.gmail.com>

On Wed, Jul 23, 2014 at 08:12:32AM -0700, Andy Lutomirski wrote:
> How are we supposed to survive two machine checks in rapid succession?
> The second will fire as soon as the first one is acked, I imagine.
> Unless we switch stacks before acking the MCE, the return address of
> the first one will be lost.

Oh, that might not fly but in that case the box probably deserves to die
anyway.

I was adressing what you said earlier: "But here's the problem: what
happens if an NMI or MCE happens between the sti and the lretq? I think
an MCE just might be okay -- it's not really recoverable anyway."

An MC Exception can be recoverable and we can recover. The fact that we
raise an exception doesn't always mean we die.

-- 
Regards/Gruss,
    Boris.

Sent from a fat crate under my desk. Formatting is fine.
--

  reply	other threads:[~2014-07-23 15:23 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-07-23  0:10 STI architectural question (and lretq -- I'm not even kidding) Andy Lutomirski
2014-07-23  1:03 ` Linus Torvalds
2014-07-23  1:33   ` Andy Lutomirski
2014-07-23 10:49     ` Borislav Petkov
2014-07-23 15:12       ` Andy Lutomirski
2014-07-23 15:23         ` Borislav Petkov [this message]
2014-07-23  9:40   ` Borislav Petkov
2014-07-23 21:18 ` Andi Kleen
2014-07-23 21:52   ` Andy Lutomirski
2014-07-23 23:10     ` Andi Kleen
2014-07-24 22:15       ` H. Peter Anvin

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20140723152311.GC21707@pd.tnic \
    --to=bp@alien8.de \
    --cc=hpa@linux.intel.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=luto@amacapital.net \
    --cc=torvalds@linux-foundation.org \
    --cc=x86@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.