From patchwork Thu Oct 4 14:05:46 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sebastian Andrzej Siewior X-Patchwork-Id: 10626215 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 3024A15E2 for ; Thu, 4 Oct 2018 14:06:25 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 20C7D2916D for ; Thu, 4 Oct 2018 14:06:25 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 1426C291BC; Thu, 4 Oct 2018 14:06:25 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id AA2C92916D for ; Thu, 4 Oct 2018 14:06:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727950AbeJDU7k (ORCPT ); Thu, 4 Oct 2018 16:59:40 -0400 Received: from Galois.linutronix.de ([146.0.238.70]:36331 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727356AbeJDU7j (ORCPT ); Thu, 4 Oct 2018 16:59:39 -0400 Received: from localhost ([127.0.0.1] helo=bazinga.breakpoint.cc) by Galois.linutronix.de with esmtp (Exim 4.80) (envelope-from ) id 1g84GV-0002ic-8f; Thu, 04 Oct 2018 16:06:07 +0200 From: Sebastian Andrzej Siewior To: linux-kernel@vger.kernel.org Cc: x86@kernel.org, Andy Lutomirski , Paolo Bonzini , =?utf-8?b?UmFkaW0gS3LEjW3DocWZ?= , kvm@vger.kernel.org, "Jason A. Donenfeld" , Rik van Riel , Dave Hansen , Sebastian Andrzej Siewior Subject: [PATCH 10/11] x86/fpu: prepare copy_fpstate_to_sigframe for TIF_LOAD_FPU Date: Thu, 4 Oct 2018 16:05:46 +0200 Message-Id: <20181004140547.13014-11-bigeasy@linutronix.de> X-Mailer: git-send-email 2.19.0 In-Reply-To: <20181004140547.13014-1-bigeasy@linutronix.de> References: <20181004140547.13014-1-bigeasy@linutronix.de> MIME-Version: 1.0 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Rik van Riel If TIF_LOAD_FPU is set, then the registers are saved (not loaded). In that case we skip the saving part. Signed-off-by: Rik van Riel Signed-off-by: Sebastian Andrzej Siewior --- arch/x86/kernel/fpu/signal.c | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-) diff --git a/arch/x86/kernel/fpu/signal.c b/arch/x86/kernel/fpu/signal.c index c8f5ff58578ed..979dcd1ed82e0 100644 --- a/arch/x86/kernel/fpu/signal.c +++ b/arch/x86/kernel/fpu/signal.c @@ -155,13 +155,17 @@ int copy_fpstate_to_sigframe(void __user *buf, void __user *buf_fx, int size) sizeof(struct user_i387_ia32_struct), NULL, (struct _fpstate_32 __user *) buf) ? -1 : 1; - /* Update the thread's fxstate to save the fsave header. */ - if (ia32_fxstate) { - copy_fxregs_to_kernel(fpu); - } else { - copy_fpregs_to_fpstate(fpu); - fpregs_deactivate(fpu); + __fpregs_changes_begin(); + if (!test_thread_flag(TIF_LOAD_FPU)) { + /* Update the thread's fxstate to save the fsave header. */ + if (ia32_fxstate) { + copy_fxregs_to_kernel(fpu); + } else { + copy_fpregs_to_fpstate(fpu); + fpregs_deactivate(fpu); + } } + __fpregs_changes_end(); if (using_compacted_format()) { copy_xstate_to_user(buf_fx, xsave, 0, size);