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=-10.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 786C9C433E0 for ; Fri, 5 Mar 2021 14:29:52 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id D484C64F4A for ; Fri, 5 Mar 2021 14:29:51 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D484C64F4A Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=alien8.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 436B96B005D; Fri, 5 Mar 2021 09:29:51 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 3E6AE6B006C; Fri, 5 Mar 2021 09:29:51 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 23B396B006E; Fri, 5 Mar 2021 09:29:51 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0050.hostedemail.com [216.40.44.50]) by kanga.kvack.org (Postfix) with ESMTP id 022F46B005D for ; Fri, 5 Mar 2021 09:29:50 -0500 (EST) Received: from smtpin27.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id B5F4B1730860 for ; Fri, 5 Mar 2021 14:29:50 +0000 (UTC) X-FDA: 77886054540.27.B51E6B3 Received: from mail.skyhub.de (mail.skyhub.de [5.9.137.197]) by imf01.hostedemail.com (Postfix) with ESMTP id 42EBA200039F for ; Fri, 5 Mar 2021 14:29:48 +0000 (UTC) Received: from zn.tnic (p200300ec2f0b9500a5847b5a228c2b11.dip0.t-ipconnect.de [IPv6:2003:ec:2f0b:9500:a584:7b5a:228c:2b11]) (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 378C51EC0521; Fri, 5 Mar 2021 15:29:46 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1614954586; 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=756DJLydScKg6OQ7shRw8IU5LHdGM90c3wF/c6DK94s=; b=hB7qolct0HXVDkhC+NG1uce7LdVUT17tmjPoMVViUOt2acE0eZclGgP6iTc6kLwqmWh5zz WXVbm2MGRnH4V8aBErUPvI2qeTMbqEQUFgpMTGb/KqMEER4gscnxIleMXQj/axZ83IpEqn 6P/a5HbB25LXW8wJeDLnwpqgIgh3j4k= Date: Fri, 5 Mar 2021 15:29:40 +0100 From: Borislav Petkov To: Yu-cheng Yu Cc: x86@kernel.org, "H. Peter Anvin" , Thomas Gleixner , Ingo Molnar , linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-mm@kvack.org, linux-arch@vger.kernel.org, linux-api@vger.kernel.org, Arnd Bergmann , Andy Lutomirski , Balbir Singh , Cyrill Gorcunov , Dave Hansen , Eugene Syromiatnikov , Florian Weimer , "H.J. Lu" , Jann Horn , Jonathan Corbet , Kees Cook , Mike Kravetz , Nadav Amit , Oleg Nesterov , Pavel Machek , Peter Zijlstra , Randy Dunlap , "Ravi V. Shankar" , Vedvyas Shanbhogue , Dave Martin , Weijiang Yang , Pengfei Xu , Haitao Huang Subject: Re: [PATCH v21 10/26] x86/mm: Update pte_modify for _PAGE_COW Message-ID: <20210305142940.GC2685@zn.tnic> References: <20210217222730.15819-1-yu-cheng.yu@intel.com> <20210217222730.15819-11-yu-cheng.yu@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20210217222730.15819-11-yu-cheng.yu@intel.com> X-Stat-Signature: 3m39q81utb66ae3i74a6w8kgczut6xf4 X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: 42EBA200039F Received-SPF: none (alien8.de>: No applicable sender policy available) receiver=imf01; identity=mailfrom; envelope-from=""; helo=mail.skyhub.de; client-ip=5.9.137.197 X-HE-DKIM-Result: pass/pass X-HE-Tag: 1614954588-789941 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Wed, Feb 17, 2021 at 02:27:14PM -0800, Yu-cheng Yu wrote: > @@ -787,16 +802,34 @@ static inline pte_t pte_modify(pte_t pte, pgprot_t newprot) > */ > val &= _PAGE_CHG_MASK; > val |= check_pgprot(newprot) & ~_PAGE_CHG_MASK; > + val = fixup_dirty_pte(val); Do I see it correctly that you can do here and below: /* * Fix up potential shadow stack page flags because the RO, Dirty PTE is * special. */ if (pte_dirty()) { pte_mkclean(); pte_mkdirty(); } ? That fixup thing looks grafted and not like a normal flow to me. -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette