From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752110AbaFDWRv (ORCPT ); Wed, 4 Jun 2014 18:17:51 -0400 Received: from terminus.zytor.com ([198.137.202.10]:36349 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751513AbaFDWRu (ORCPT ); Wed, 4 Jun 2014 18:17:50 -0400 Message-ID: <538F9AFA.5050806@zytor.com> Date: Wed, 04 Jun 2014 15:17:30 -0700 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.5.0 MIME-Version: 1.0 To: linux-kernel@vger.kernel.org, mingo@kernel.org, ricardo.neri-calderon@linux.intel.com, tglx@linutronix.de, bp@suse.de, matt.fleming@intel.com, linux-tip-commits@vger.kernel.org Subject: Re: [tip:x86/efi] x86/efi: Check for unsafe dealing with FPU state in irq ctxt References: In-Reply-To: X-Enigmail-Version: 1.6 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 06/04/2014 03:15 PM, tip-bot for Borislav Petkov wrote: > Commit-ID: baa916f39b50ad91661534652110df40396acda0 > Gitweb: http://git.kernel.org/tip/baa916f39b50ad91661534652110df40396acda0 > Author: Borislav Petkov > AuthorDate: Fri, 25 Apr 2014 13:40:10 +0200 > Committer: Matt Fleming > CommitDate: Sat, 3 May 2014 06:39:25 +0100 > > x86/efi: Check for unsafe dealing with FPU state in irq ctxt > > efi_call can happen in an irq context (pstore) and there we really need > to make sure we're not scribbling over FPU state while we've interrupted > a thread or kernel mode with a live FPU state. Therefore, use the > kernel_fpu_begin/end() variants which do that check. > > Signed-off-by: Borislav Petkov > Cc: Ricardo Neri > Signed-off-by: Matt Fleming > --- > arch/x86/include/asm/efi.h | 6 ++---- > 1 file changed, 2 insertions(+), 4 deletions(-) > I seem to have lost track of this... does this actually solve anything, or does it just mean we'll explode hard? -hpa