From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752104AbbCKRhA (ORCPT ); Wed, 11 Mar 2015 13:37:00 -0400 Received: from mx1.redhat.com ([209.132.183.28]:59102 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750949AbbCKRg7 (ORCPT ); Wed, 11 Mar 2015 13:36:59 -0400 Date: Wed, 11 Mar 2015 18:34:49 +0100 From: Oleg Nesterov To: Dave Hansen , Borislav Petkov , Ingo Molnar Cc: Andy Lutomirski , Linus Torvalds , Pekka Riikonen , Rik van Riel , Suresh Siddha , LKML , "Yu, Fenghua" , Quentin Casasnovas Subject: [PATCH 3/4] x86/fpu: use restore_init_xstate() instead of math_state_restore() on kthread exec Message-ID: <20150311173449.GE5032@redhat.com> References: <54F74F59.5070107@intel.com> <20150311173346.GB5032@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150311173346.GB5032@redhat.com> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Change flush_thread() to do user_fpu_begin() + restore_init_xstate() and avoid math_state_restore(). Note: "TODO: cleanup this horror" is still valid. We do not need init_fpu() at all, we only need fpu_alloc() + memset(0). But this needs other changes, in particular user_fpu_begin() should set used_math(). Signed-off-by: Oleg Nesterov --- arch/x86/kernel/process.c | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-) diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index dd9a069..c396de2 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -142,7 +142,8 @@ void flush_thread(void) /* kthread execs. TODO: cleanup this horror. */ if (WARN_ON(init_fpu(current))) force_sig(SIGKILL, current); - math_state_restore(); + user_fpu_begin(); + restore_init_xstate(); } } -- 1.5.5.1