From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Willy Tarreau <w@1wt.eu>, "H. Peter Anvin" <hpa@zytor.com>,
stable@vger.kernel.org, Raphael Prevost <raphael@buro.asia>,
Suresh Siddha <suresh.b.siddha@intel.com>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 0/5] i387: stable kernel backport
Date: Thu, 23 Feb 2012 14:59:34 -0800 [thread overview]
Message-ID: <20120223225934.GA7362@kroah.com> (raw)
In-Reply-To: <CA+55aFxztx=Cf8i+jZE=X8Zx1BZnNpC6wv-PkWcXDfBFS6qWqg@mail.gmail.com>
On Thu, Feb 23, 2012 at 02:38:42PM -0800, Linus Torvalds wrote:
> On Thu, Feb 23, 2012 at 2:27 PM, Willy Tarreau <w@1wt.eu> wrote:
> >
> > OK so indeed I will only be able to check that it boots :-/
>
> Well, we could do some trivial test-harness that just forces the issue
> with regular timer interrupts (and even without AES-NI). I think Peter
> talked about that when we were trying to hunt it down - but I think he
> was then able to reproduce the problem without anything special and we
> dropped it.
>
> Essentially, just doing something like
>
> if (irq_fpu_usable()) {
> kernel_fpu_begin();
> kernel_fpu_end();
> }
>
> in do_irq() and do_softirq() would stress-test things even without
> wireless, and even without AES-NI.
>
> You'd still need an x86-32 machine to test on, because x86-64 was
> immune to this issue.
>
> But yeah, the impact of this seems to be small enough that for older
> kernels (which are likely used on older systems for maintenance
> anyway) disabling AES-NI on x86-32 really might be the way to go.
I think that's already the case, 2.6.32 has the following depends for
CRYPTO_AES_NI_INTEL:
depends on (X86 || UML_X86) && 64BIT
It was this way until commit 0d258efb (crypto: aesni-intel - Ported
implementation to x86-32) which showed up in 2.6.38.
So we should be safe for 2.6.32 no changes needed, right?
greg k-h
next prev parent reply other threads:[~2012-02-23 22:59 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-02-22 20:54 [PATCH 0/5] i387: stable kernel backport Linus Torvalds
2012-02-22 20:56 ` [PATCH 1/5] i387: math_state_restore() isn't called from asm Linus Torvalds
2012-02-22 20:56 ` [PATCH 2/5] i387: make irq_fpu_usable() tests more robust Linus Torvalds
2012-02-22 20:57 ` [PATCH 3/5] i387: fix x86-64 preemption-unsafe user stack save/restore Linus Torvalds
2012-02-22 20:58 ` [PATCH 4/5] i387: move TS_USEDFPU clearing out of __save_init_fpu and into callers Linus Torvalds
2012-02-22 20:59 ` [PATCH 5/5] i387: move TS_USEDFPU flag from thread_info to task_struct Linus Torvalds
2012-02-22 21:02 ` [PATCH 0/5] i387: stable kernel backport H. Peter Anvin
2012-02-22 21:19 ` Greg Kroah-Hartman
2012-02-22 21:29 ` Linus Torvalds
2012-02-22 21:30 ` Linus Torvalds
2012-02-22 21:32 ` Greg Kroah-Hartman
2012-02-23 20:09 ` Greg Kroah-Hartman
2012-02-23 20:29 ` H. Peter Anvin
2012-02-23 20:48 ` Greg Kroah-Hartman
2012-02-23 20:51 ` H. Peter Anvin
2012-02-23 21:10 ` Greg Kroah-Hartman
2012-02-23 21:52 ` Willy Tarreau
2012-02-23 22:11 ` Linus Torvalds
2012-02-23 22:27 ` Willy Tarreau
2012-02-23 22:38 ` Linus Torvalds
2012-02-23 22:48 ` H. Peter Anvin
2012-02-23 22:52 ` Willy Tarreau
2012-02-23 22:55 ` H. Peter Anvin
2012-02-23 23:04 ` Willy Tarreau
2012-02-23 22:49 ` Willy Tarreau
2012-02-23 22:59 ` Greg Kroah-Hartman [this message]
2012-02-23 23:05 ` H. Peter Anvin
2012-02-23 23:16 ` Greg Kroah-Hartman
2012-02-23 23:18 ` H. Peter Anvin
2012-02-23 23:19 ` Suresh Siddha
2012-02-23 23:54 ` Greg Kroah-Hartman
2012-02-23 23:59 ` H. Peter Anvin
2012-02-24 0:47 ` H. Peter Anvin
2012-02-22 22:34 ` H. Peter Anvin
2012-02-22 22:45 ` H. Peter Anvin
2012-02-22 23:15 ` Linus Torvalds
2012-02-22 23:31 ` Linus Torvalds
2012-02-23 0:14 ` H. Peter Anvin
2012-02-23 0:25 ` Linus Torvalds
2012-02-23 0:37 ` Greg Kroah-Hartman
2012-02-23 1:47 ` raphael
2012-02-23 2:55 ` Linus Torvalds
2012-02-23 2:41 ` raphael
2012-02-23 3:37 ` Linus Torvalds
2012-02-23 18:15 ` Greg Kroah-Hartman
2012-02-23 19:36 ` Greg Kroah-Hartman
2012-02-23 19:41 ` Linus Torvalds
2012-02-23 19:50 ` Greg Kroah-Hartman
2012-02-23 19:55 ` Greg Kroah-Hartman
2012-02-23 20:02 ` Greg Kroah-Hartman
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=20120223225934.GA7362@kroah.com \
--to=gregkh@linuxfoundation.org \
--cc=hpa@zytor.com \
--cc=linux-kernel@vger.kernel.org \
--cc=raphael@buro.asia \
--cc=stable@vger.kernel.org \
--cc=suresh.b.siddha@intel.com \
--cc=torvalds@linux-foundation.org \
--cc=w@1wt.eu \
/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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).