From: "H. Peter Anvin" <hpa@zytor.com>
To: Linus Torvalds <torvalds@linux-foundation.org>,
Borislav Petkov <bp@alien8.de>
Cc: halfdog <me@halfdog.net>,
Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>,
the arch/x86 maintainers <x86@kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Ben Hutchings <ben@decadent.org.uk>
Subject: Re: Sanitize CPU-state when switching tasks (was sanitize CPU-state when switching from virtual-8086 mode to other task)
Date: Thu, 09 Jan 2014 18:13:19 -0800 [thread overview]
Message-ID: <52CF573F.8030300@zytor.com> (raw)
In-Reply-To: <CA+55aFxQnY_PCG_n4=0w-VG=YLXL-yr7oMxyy0WU2gCBAf3ydg@mail.gmail.com>
On 01/09/2014 04:42 PM, Linus Torvalds wrote:
> On Fri, Jan 10, 2014 at 6:58 AM, Borislav Petkov <bp@alien8.de> wrote:
>>
>> Ok, I was able to reproduce
>
> Looking at this, I think this is just a bug in our
> restore_fpu_checking() hackery for X86_FEATURE_FXSAVE_LEAK..
>
> Which also explains why it only triggers on E-350 - it's only relevant
> for those K7/K8 CPU's that use this.
>
> Maybe just add a fcnlex to before the emms? Something like this
> (TOTALLY UNTESTED!!) attached patch.
>
OK, that sounds very reasonable. Boris, halfdog, does something like
this resolve your problem?
-hpa
next prev parent reply other threads:[~2014-01-10 2:14 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-12-28 22:02 Sanitize CPU-state when switching from virtual-8086 mode to other task halfdog
2013-12-29 2:37 ` H. Peter Anvin
2013-12-29 20:44 ` halfdog
2013-12-30 1:18 ` H. Peter Anvin
2013-12-30 15:52 ` halfdog
2013-12-31 18:42 ` H. Peter Anvin
2013-12-31 19:21 ` Konrad Rzeszutek Wilk
2013-12-31 22:40 ` H. Peter Anvin
2014-01-03 23:07 ` Sanitize FPU-state when switching tasks (was sanitize CPU-state when switching from virtual-8086 mode to other task) halfdog
2014-01-08 7:45 ` Sanitize CPU-state " halfdog
2014-01-08 17:42 ` H. Peter Anvin
2014-01-08 19:36 ` Borislav Petkov
2014-01-08 21:28 ` halfdog
2014-01-08 22:39 ` H. Peter Anvin
2014-01-09 22:58 ` Borislav Petkov
2014-01-10 0:42 ` Linus Torvalds
2014-01-10 2:13 ` H. Peter Anvin [this message]
2014-01-10 10:06 ` Borislav Petkov
2014-01-10 11:16 ` Linus Torvalds
2014-01-10 11:34 ` Borislav Petkov
2014-01-10 16:11 ` H. Peter Anvin
2014-01-12 3:22 ` [tip:x86/urgent] x86, fpu, amd: Clear exceptions in AMD FXSAVE workaround tip-bot for Linus Torvalds
2014-01-09 22:50 ` Sanitize CPU-state when switching tasks (was sanitize CPU-state when switching from virtual-8086 mode to other task) halfdog
2014-01-09 23:02 ` Borislav Petkov
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