Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757228Ab2BWW7m (ORCPT ); Thu, 23 Feb 2012 17:59:42 -0500 Received: from mail-pw0-f46.google.com ([209.85.160.46]:49312 "EHLO mail-pw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756544Ab2BWW7l (ORCPT ); Thu, 23 Feb 2012 17:59:41 -0500 Authentication-Results: mr.google.com; spf=pass (google.com: domain of gregkh@linuxfoundation.org designates 10.68.228.69 as permitted sender) smtp.mail=gregkh@linuxfoundation.org Date: Thu, 23 Feb 2012 14:59:34 -0800 From: Greg Kroah-Hartman To: Linus Torvalds Cc: Willy Tarreau , "H. Peter Anvin" , stable@vger.kernel.org, Raphael Prevost , Suresh Siddha , Linux Kernel Mailing List Subject: Re: [PATCH 0/5] i387: stable kernel backport Message-ID: <20120223225934.GA7362@kroah.com> References: <20120222213253.GA25150@kroah.com> <20120223200905.GA5475@kroah.com> <4F46A1C4.90506@zytor.com> <20120223204832.GA30322@kroah.com> <4F46A6EC.8050804@zytor.com> <20120223211016.GA16275@kroah.com> <20120223215242.GA1306@1wt.eu> <20120223222733.GB1306@1wt.eu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1628 Lines: 42 On Thu, Feb 23, 2012 at 02:38:42PM -0800, Linus Torvalds wrote: > On Thu, Feb 23, 2012 at 2:27 PM, Willy Tarreau 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 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/