From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 62E03ECDFC1 for ; Wed, 12 Sep 2018 13:36:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2567120880 for ; Wed, 12 Sep 2018 13:36:20 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2567120880 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linutronix.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728153AbeILSkt (ORCPT ); Wed, 12 Sep 2018 14:40:49 -0400 Received: from Galois.linutronix.de ([146.0.238.70]:43918 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726642AbeILSkf (ORCPT ); Wed, 12 Sep 2018 14:40:35 -0400 Received: from localhost ([127.0.0.1] helo=bazinga.breakpoint.cc) by Galois.linutronix.de with esmtp (Exim 4.80) (envelope-from ) id 1g05JG-0001Ap-7u; Wed, 12 Sep 2018 15:35:58 +0200 From: Sebastian Andrzej Siewior To: linux-kernel@vger.kernel.org Cc: x86@kernel.org, Andy Lutomirski , Paolo Bonzini , =?UTF-8?q?Radim=20Kr=C4=8Dm=C3=A1=C5=99?= , kvm@vger.kernel.org, "Jason A. Donenfeld" , Rik van Riel , Sebastian Andrzej Siewior Subject: [RFC PATCH 09/10] x86/fpu: copy non-resident FPU state at fork time Date: Wed, 12 Sep 2018 15:33:52 +0200 Message-Id: <20180912133353.20595-10-bigeasy@linutronix.de> X-Mailer: git-send-email 2.19.0 In-Reply-To: <20180912133353.20595-1-bigeasy@linutronix.de> References: <20180912133353.20595-1-bigeasy@linutronix.de> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Rik van Riel If the FPU state is not loaded in registers at fork time, memcpy the fpstate from the parent task to the child task. Signed-off-by: Rik van Riel Signed-off-by: Sebastian Andrzej Siewior --- arch/x86/kernel/fpu/core.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c index 2ea85b32421a0..8564086c217fc 100644 --- a/arch/x86/kernel/fpu/core.c +++ b/arch/x86/kernel/fpu/core.c @@ -210,11 +210,14 @@ int fpu__copy(struct fpu *dst_fpu, struct fpu *src_fpu) * ( The function 'fails' in the FNSAVE case, which destroys * register contents so we have to copy them back. ) */ - if (!copy_fpregs_to_fpstate(dst_fpu)) { + __fpregs_changes_begin(); + if (test_thread_flag(TIF_LOAD_FPU)) { + memcpy(&src_fpu->state, &dst_fpu->state, fpu_kernel_xstate_size); + } else if (!copy_fpregs_to_fpstate(dst_fpu)) { memcpy(&src_fpu->state, &dst_fpu->state, fpu_kernel_xstate_size); copy_kernel_to_fpregs(&src_fpu->state); } - + __fpregs_changes_end(); trace_x86_fpu_copy_src(src_fpu); trace_x86_fpu_copy_dst(dst_fpu); -- 2.19.0