From: Willy Tarreau <w@1wt.eu>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
"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 23:27:33 +0100 [thread overview]
Message-ID: <20120223222733.GB1306@1wt.eu> (raw)
In-Reply-To: <CA+55aFyxB4kmmSOKDSRkAkaRx=G7o7JnuUGBu3_WVr9KbpWWYQ@mail.gmail.com>
On Thu, Feb 23, 2012 at 02:11:48PM -0800, Linus Torvalds wrote:
> On Thu, Feb 23, 2012 at 1:52 PM, Willy Tarreau <w@1wt.eu> wrote:
> >
> > I would test this too, but apart from ensuring my kernel still boots,
> > how do I ensure the patches do really fix what the ought to fix ? I
> > must admit I didn't catch the initial issue they were supposed to fix
> > unfortunately :-/
>
> Almost nobody did.
>
> This only happens on modern CPU's that support the new AES-NI
> instructions, and only with a 32-bit kernel (although the very
> unlikely preemption issues can happen on x86-64 too). And you need to
> have the AES instructions called from interrupts, which probably only
> happens with the mac80211 wireless networking stack.
>
> And even then you need WPA2 to trigger it (I guess AES is sometimes
> used with "extended WPA1" too, but I dunno).
>
> So it's not impossible to trigger, but you do need to have a fairly
> recent CPU that happily runs in 64-bit mode, and install a 32-bit
> system on it. And it needs to use the right wireless setup.
OK so indeed I will only be able to check that it boots :-/
> It's possible that the right solution for really older kernels is just
> to say that AES_NI depends on X86_64.
Might be a good idea !
Thanks for the explanation,
Willy
next prev parent reply other threads:[~2012-02-23 22:27 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 [this message]
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
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
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