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=-12.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED 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 E0720C10F11 for ; Sat, 13 Apr 2019 20:59:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AF2A82084E for ; Sat, 13 Apr 2019 20:59:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727229AbfDMU7x (ORCPT ); Sat, 13 Apr 2019 16:59:53 -0400 Received: from terminus.zytor.com ([198.137.202.136]:37463 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726620AbfDMU7x (ORCPT ); Sat, 13 Apr 2019 16:59:53 -0400 Received: from terminus.zytor.com (localhost [127.0.0.1]) by terminus.zytor.com (8.15.2/8.15.2) with ESMTPS id x3DKwYHN2266938 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NO); Sat, 13 Apr 2019 13:58:34 -0700 Received: (from tipbot@localhost) by terminus.zytor.com (8.15.2/8.15.2/Submit) id x3DKwYvp2266935; Sat, 13 Apr 2019 13:58:34 -0700 Date: Sat, 13 Apr 2019 13:58:34 -0700 X-Authentication-Warning: terminus.zytor.com: tipbot set sender to tipbot@zytor.com using -f From: tip-bot for Rik van Riel Message-ID: Cc: bigeasy@linutronix.de, hpa@zytor.com, dave.hansen@intel.com, tglx@linutronix.de, kvm@vger.kernel.org, bp@suse.de, rkrcmar@redhat.com, pbonzini@redhat.com, luto@kernel.org, mingo@redhat.com, mingo@kernel.org, x86@kernel.org, linux-kernel@vger.kernel.org, Jason@zx2c4.com, riel@surriel.com, jannh@google.com Reply-To: rkrcmar@redhat.com, pbonzini@redhat.com, bp@suse.de, kvm@vger.kernel.org, hpa@zytor.com, bigeasy@linutronix.de, dave.hansen@intel.com, tglx@linutronix.de, linux-kernel@vger.kernel.org, mingo@kernel.org, x86@kernel.org, luto@kernel.org, mingo@redhat.com, Jason@zx2c4.com, riel@surriel.com, jannh@google.com In-Reply-To: <20190403164156.19645-19-bigeasy@linutronix.de> References: <20190403164156.19645-19-bigeasy@linutronix.de> To: linux-tip-commits@vger.kernel.org Subject: [tip:x86/fpu] x86/fpu: Prepare copy_fpstate_to_sigframe() for TIF_NEED_FPU_LOAD Git-Commit-ID: a352a3b7b7920212ee4c45a41500c66826318e92 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: a352a3b7b7920212ee4c45a41500c66826318e92 Gitweb: https://git.kernel.org/tip/a352a3b7b7920212ee4c45a41500c66826318e92 Author: Rik van Riel AuthorDate: Wed, 3 Apr 2019 18:41:47 +0200 Committer: Borislav Petkov CommitDate: Thu, 11 Apr 2019 18:20:04 +0200 x86/fpu: Prepare copy_fpstate_to_sigframe() for TIF_NEED_FPU_LOAD The FPU registers need only to be saved if TIF_NEED_FPU_LOAD is not set. Otherwise this has been already done and can be skipped. [ bp: Massage a bit. ] Signed-off-by: Rik van Riel Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Borislav Petkov Reviewed-by: Dave Hansen Reviewed-by: Thomas Gleixner Cc: Andy Lutomirski Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: Jann Horn Cc: "Jason A. Donenfeld" Cc: kvm ML Cc: Paolo Bonzini Cc: Radim Krčmář Cc: Rik van Riel Cc: x86-ml Link: https://lkml.kernel.org/r/20190403164156.19645-19-bigeasy@linutronix.de --- arch/x86/kernel/fpu/signal.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/arch/x86/kernel/fpu/signal.c b/arch/x86/kernel/fpu/signal.c index 8f23f5237218..9b9dfdc96285 100644 --- a/arch/x86/kernel/fpu/signal.c +++ b/arch/x86/kernel/fpu/signal.c @@ -171,7 +171,17 @@ 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; - copy_fpregs_to_fpstate(fpu); + /* + * If we do not need to load the FPU registers at return to userspace + * then the CPU has the current state and we need to save it. Otherwise, + * it has already been done and we can skip it. + */ + fpregs_lock(); + if (!test_thread_flag(TIF_NEED_FPU_LOAD)) { + copy_fpregs_to_fpstate(fpu); + set_thread_flag(TIF_NEED_FPU_LOAD); + } + fpregs_unlock(); if (using_compacted_format()) { if (copy_xstate_to_user(buf_fx, xsave, 0, size))