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=-12.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 0036EC28CC5 for ; Sat, 8 Jun 2019 09:49:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CD1D7214AE for ; Sat, 8 Jun 2019 09:49:48 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=zytor.com header.i=@zytor.com header.b="SqzFiLK7" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726785AbfFHJto (ORCPT ); Sat, 8 Jun 2019 05:49:44 -0400 Received: from terminus.zytor.com ([198.137.202.136]:54697 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726638AbfFHJto (ORCPT ); Sat, 8 Jun 2019 05:49:44 -0400 Received: from terminus.zytor.com (localhost [127.0.0.1]) by terminus.zytor.com (8.15.2/8.15.2) with ESMTPS id x589nGY12915658 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NO); Sat, 8 Jun 2019 02:49:16 -0700 DKIM-Filter: OpenDKIM Filter v2.11.0 terminus.zytor.com x589nGY12915658 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zytor.com; s=2019051801; t=1559987357; bh=xud/tY9QU6ISxDLO94RhQ0+L8m6TRftpBj+aXoE8ZlA=; h=Date:From:Cc:Reply-To:In-Reply-To:References:To:Subject:From; b=SqzFiLK7+eZYQkM0zs8MoLsNh7GMhvTLfJQfBI/1cubIYlmpkEu3Z9QRSdwHG50RI N7d7WS5Fy2bOgLBLxUQJYQVNGkjiViHoxjMj9ZHV0Sh+mTV2r39WMqNjjd5ydqzJIu X+QV/WMypPdd3WToFeSX+iGR0o9RtBPEHoRPGho643+nWg7DQJ66PEiLPrl+oMSMWm KFOqYtN+dyC8frYYb3XOJQJbw6OzaLePpJO/OaYQM1D72fnoIInPeFVZydr62pxJJ9 C3q1ShPH9WlcumoFNBPdtaN+XLQ3HLYoPYbETLewZb4WcXH4dkVquU+GG204jfag+l kPuzgR35FdkBA== Received: (from tipbot@localhost) by terminus.zytor.com (8.15.2/8.15.2/Submit) id x589nEsi2915653; Sat, 8 Jun 2019 02:49:14 -0700 Date: Sat, 8 Jun 2019 02:49:14 -0700 X-Authentication-Warning: terminus.zytor.com: tipbot set sender to tipbot@zytor.com using -f From: tip-bot for Sebastian Andrzej Siewior Message-ID: Cc: mingo@kernel.org, bigeasy@linutronix.de, riel@surriel.com, tglx@linutronix.de, dave.hansen@intel.com, rkrcmar@redhat.com, Jason@zx2c4.com, ebiggers@kernel.org, luto@kernel.org, hughd@google.com, kvm@vger.kernel.org, mingo@redhat.com, bp@suse.de, x86@kernel.org, hpa@zytor.com, jannh@google.com, pbonzini@redhat.com, linux-kernel@vger.kernel.org Reply-To: x86@kernel.org, hpa@zytor.com, bp@suse.de, hughd@google.com, mingo@redhat.com, kvm@vger.kernel.org, pbonzini@redhat.com, jannh@google.com, linux-kernel@vger.kernel.org, bigeasy@linutronix.de, mingo@kernel.org, tglx@linutronix.de, riel@surriel.com, dave.hansen@intel.com, ebiggers@kernel.org, rkrcmar@redhat.com, Jason@zx2c4.com, luto@kernel.org In-Reply-To: <20190607142915.y52mfmgk5lvhll7n@linutronix.de> References: <20190607142915.y52mfmgk5lvhll7n@linutronix.de> To: linux-tip-commits@vger.kernel.org Subject: [tip:x86/urgent] x86/fpu: Update kernel's FPU state before using for the fsave header Git-Commit-ID: aab8445c4e1cceeb3f739352041ec1c2586bc923 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: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Commit-ID: aab8445c4e1cceeb3f739352041ec1c2586bc923 Gitweb: https://git.kernel.org/tip/aab8445c4e1cceeb3f739352041ec1c2586bc923 Author: Sebastian Andrzej Siewior AuthorDate: Fri, 7 Jun 2019 16:29:16 +0200 Committer: Borislav Petkov CommitDate: Sat, 8 Jun 2019 11:45:15 +0200 x86/fpu: Update kernel's FPU state before using for the fsave header In commit 39388e80f9b0c ("x86/fpu: Don't save fxregs for ia32 frames in copy_fpstate_to_sigframe()") I removed the statement | if (ia32_fxstate) | copy_fxregs_to_kernel(fpu); and argued that it was wrongly merged because the content was already saved in kernel's state. This was wrong: It is required to write it back because it is only saved on the user-stack and save_fsave_header() reads it from task's FPU-state. I missed that part… Save x87 FPU state unless thread's FPU registers are already up to date. Fixes: 39388e80f9b0c ("x86/fpu: Don't save fxregs for ia32 frames in copy_fpstate_to_sigframe()") Reported-by: Eric Biggers Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Borislav Petkov Tested-by: Eric Biggers Cc: Andy Lutomirski Cc: Dave Hansen Cc: "H. Peter Anvin" Cc: Hugh Dickins Cc: Ingo Molnar Cc: Jann Horn Cc: "Jason A. Donenfeld" Cc: kvm ML Cc: Paolo Bonzini Cc: Radim Krčmář Cc: Rik van Riel Cc: Thomas Gleixner Cc: x86-ml Link: https://lkml.kernel.org/r/20190607142915.y52mfmgk5lvhll7n@linutronix.de --- arch/x86/kernel/fpu/signal.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/arch/x86/kernel/fpu/signal.c b/arch/x86/kernel/fpu/signal.c index 060d6188b453..0071b794ed19 100644 --- a/arch/x86/kernel/fpu/signal.c +++ b/arch/x86/kernel/fpu/signal.c @@ -62,6 +62,11 @@ static inline int save_fsave_header(struct task_struct *tsk, void __user *buf) struct user_i387_ia32_struct env; struct _fpstate_32 __user *fp = buf; + fpregs_lock(); + if (!test_thread_flag(TIF_NEED_FPU_LOAD)) + copy_fxregs_to_kernel(&tsk->thread.fpu); + fpregs_unlock(); + convert_from_fxsr(&env, tsk); if (__copy_to_user(buf, &env, sizeof(env)) ||