From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030244AbbEES1G (ORCPT ); Tue, 5 May 2015 14:27:06 -0400 Received: from mail-wi0-f174.google.com ([209.85.212.174]:35483 "EHLO mail-wi0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752201AbbEERxB (ORCPT ); Tue, 5 May 2015 13:53:01 -0400 From: Ingo Molnar To: linux-kernel@vger.kernel.org Cc: Andy Lutomirski , Borislav Petkov , Dave Hansen , Fenghua Yu , "H. Peter Anvin" , Linus Torvalds , Oleg Nesterov , Thomas Gleixner Subject: [PATCH 111/208] x86/fpu: Do CLTS fpu__init_system() Date: Tue, 5 May 2015 19:50:03 +0200 Message-Id: <1430848300-27877-33-git-send-email-mingo@kernel.org> X-Mailer: git-send-email 2.1.0 In-Reply-To: <1430848300-27877-1-git-send-email-mingo@kernel.org> References: <1430848300-27877-1-git-send-email-mingo@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org mxcsr_feature_mask_init() depends on TS being cleared, as it executes an FXSAVE instruction. After later changes we will move the TS setup into fpu__init_cpu(), which will interact with this - so clear the TS flag explicitly. Reviewed-by: Borislav Petkov Cc: Andy Lutomirski Cc: Dave Hansen Cc: Fenghua Yu Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Oleg Nesterov Cc: Thomas Gleixner Signed-off-by: Ingo Molnar --- arch/x86/kernel/fpu/init.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/arch/x86/kernel/fpu/init.c b/arch/x86/kernel/fpu/init.c index 2752b4bae854..567e7e6cdc6b 100644 --- a/arch/x86/kernel/fpu/init.c +++ b/arch/x86/kernel/fpu/init.c @@ -214,6 +214,13 @@ void fpu__init_system(void) fpu__init_cpu(); /* + * But don't leave CR0::TS set yet, as some of the FPU setup methods depend + * on being able to execute FPU instructions that will fault on a set TS, + * such as the FXSAVE in mxcsr_feature_mask_init(). + */ + clts(); + + /* * Set up the legacy init FPU context. (xstate init might overwrite this * with a more modern format, if the CPU supports it.) */ -- 2.1.0