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=-8.3 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 93912C38A2A for ; Thu, 7 May 2020 13:11:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 68BD120838 for ; Thu, 7 May 2020 13:11:53 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=alien8.de header.i=@alien8.de header.b="n51Rn83w" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726464AbgEGNLw (ORCPT ); Thu, 7 May 2020 09:11:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37058 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1725857AbgEGNLv (ORCPT ); Thu, 7 May 2020 09:11:51 -0400 Received: from mail.skyhub.de (mail.skyhub.de [IPv6:2a01:4f8:190:11c2::b:1457]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A3623C05BD43 for ; Thu, 7 May 2020 06:11:51 -0700 (PDT) Received: from zn.tnic (p200300EC2F0B6A0029AA22443DE255A6.dip0.t-ipconnect.de [IPv6:2003:ec:2f0b:6a00:29aa:2244:3de2:55a6]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.skyhub.de (SuperMail on ZX Spectrum 128k) with ESMTPSA id BD3F61EC034B; Thu, 7 May 2020 15:11:47 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1588857107; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:in-reply-to:in-reply-to: references:references; bh=E20OXuV+EnYUFdXJHJBT+cw6g5yrTYVS4U7ukdVv+74=; b=n51Rn83wku7F/3qcyGr68GzLR+aOLw6jiMALFfXXeH8gEZVw3mnx/BfD8uYKGIYD6vTr7l WGXx0xU1K8JLR0D+e2ymSUB8HGMTSfdi8yneVs0RzoPoZdjybA74DBDeg5ZJS2+9O/gJpE kXCUFvjRcr8n5Nj4SMiKkCsucG3+j4k= Date: Thu, 7 May 2020 15:11:42 +0200 From: Borislav Petkov To: Yu-cheng Yu Cc: linux-kernel@vger.kernel.org, x86@kernel.org, "H. Peter Anvin" , Thomas Gleixner , Ingo Molnar , Dave Hansen , Tony Luck , Andy Lutomirski , Rik van Riel , "Ravi V. Shankar" , Sebastian Andrzej Siewior , Fenghua Yu , Peter Zijlstra Subject: Re: [PATCH v3 06/10] x86/fpu/xstate: Update sanitize_restored_xstate() for supervisor xstates Message-ID: <20200507131142.GA23026@zn.tnic> References: <20200328164307.17497-1-yu-cheng.yu@intel.com> <20200328164307.17497-7-yu-cheng.yu@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20200328164307.17497-7-yu-cheng.yu@intel.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Mar 28, 2020 at 09:43:03AM -0700, Yu-cheng Yu wrote: > The function sanitize_restored_xstate() sanitizes user xstates of an XSAVE > buffer by setting the buffer's header->xfeatures to the input 'xfeatures', It doesn't set them to the input xfeatures. I see a "&=" there. > effectively resetting features not in 'xfeatures' back to the init state. > > When supervisor xstates are introduced, it is necessary to make sure only > user xstates are sanitized. Ensure supervisor bits in header->xfeatures > stay set and supervisor states are not modified. > > To make names clear, also: > > - Rename the function to sanitize_restored_user_xstate(). > - Rename input parameter 'xfeatures' to 'xfeatures_from_user'. > - In __fpu__restore_sig(), rename 'xfeatures' to 'user_xfeatures'. > > v3: > - Change xfeatures_user to user_xfeatures. > > Signed-off-by: Yu-cheng Yu > Reviewed-by: Dave Hansen > --- > arch/x86/kernel/fpu/signal.c | 37 +++++++++++++++++++++++------------- > 1 file changed, 24 insertions(+), 13 deletions(-) > > diff --git a/arch/x86/kernel/fpu/signal.c b/arch/x86/kernel/fpu/signal.c > index cd6eafba12da..d09d72334a12 100644 > --- a/arch/x86/kernel/fpu/signal.c > +++ b/arch/x86/kernel/fpu/signal.c > @@ -211,9 +211,9 @@ int copy_fpstate_to_sigframe(void __user *buf, void __user *buf_fx, int size) > } > > static inline void > -sanitize_restored_xstate(union fpregs_state *state, > - struct user_i387_ia32_struct *ia32_env, > - u64 xfeatures, int fx_only) > +sanitize_restored_user_xstate(union fpregs_state *state, > + struct user_i387_ia32_struct *ia32_env, > + u64 xfeatures_from_user, int fx_only) Name those user_xfeatures too. -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette