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=-5.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 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 C2F80C3A59E for ; Tue, 20 Aug 2019 13:39:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 99C5A2087E for ; Tue, 20 Aug 2019 13:39:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730029AbfHTNjm (ORCPT ); Tue, 20 Aug 2019 09:39:42 -0400 Received: from Galois.linutronix.de ([193.142.43.55]:52033 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728248AbfHTNjm (ORCPT ); Tue, 20 Aug 2019 09:39:42 -0400 Received: from p5de0b6c5.dip0.t-ipconnect.de ([93.224.182.197] helo=nanos) by Galois.linutronix.de with esmtpsa (TLS1.2:DHE_RSA_AES_256_CBC_SHA256:256) (Exim 4.80) (envelope-from ) id 1i04MI-0006WU-TW; Tue, 20 Aug 2019 15:39:35 +0200 Date: Tue, 20 Aug 2019 15:39:34 +0200 (CEST) From: Thomas Gleixner To: Song Liu cc: Peter Zijlstra , "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" , Kernel Team , "stable@vger.kernel.org" , Joerg Roedel , Dave Hansen , Andy Lutomirski Subject: Re: [PATCH] x86/mm/pti: in pti_clone_pgtable() don't increase addr by PUD_SIZE In-Reply-To: <44EA504D-2388-49EF-A807-B9712903B146@fb.com> Message-ID: References: <20190820075128.2912224-1-songliubraving@fb.com> <20190820100055.GI2332@hirez.programming.kicks-ass.net> <44EA504D-2388-49EF-A807-B9712903B146@fb.com> User-Agent: Alpine 2.21 (DEB 202 2017-01-01) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 20 Aug 2019, Song Liu wrote: > > On Aug 20, 2019, at 4:16 AM, Thomas Gleixner wrote: > > > > On Tue, 20 Aug 2019, Peter Zijlstra wrote: > >> What that code wants to do is skip to the end of the pud, a pmd_size > >> increase will not do that. And right below this, there's a second > >> instance of this exact pattern. > >> > >> Did I get the below right? > >> > >> --- > >> diff --git a/arch/x86/mm/pti.c b/arch/x86/mm/pti.c > >> index b196524759ec..32b20b3cb227 100644 > >> --- a/arch/x86/mm/pti.c > >> +++ b/arch/x86/mm/pti.c > >> @@ -330,12 +330,14 @@ pti_clone_pgtable(unsigned long start, unsigned long end, > >> > >> pud = pud_offset(p4d, addr); > >> if (pud_none(*pud)) { > >> + addr &= PUD_MASK; > >> addr += PUD_SIZE; > > > > round_up(addr, PUD_SIZE); > > I guess we need "round_up(addr + PMD_SIZE, PUD_SIZE)". Right you are. 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=-5.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,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 30FA0C3A589 for ; Tue, 20 Aug 2019 13:39:41 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id F218B2087E for ; Tue, 20 Aug 2019 13:39:40 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F218B2087E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linutronix.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 8E5986B026E; Tue, 20 Aug 2019 09:39:40 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 895776B026F; Tue, 20 Aug 2019 09:39:40 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 783AF6B0270; Tue, 20 Aug 2019 09:39:40 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0002.hostedemail.com [216.40.44.2]) by kanga.kvack.org (Postfix) with ESMTP id 567006B026E for ; Tue, 20 Aug 2019 09:39:40 -0400 (EDT) Received: from smtpin06.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with SMTP id 034508248ABF for ; Tue, 20 Aug 2019 13:39:40 +0000 (UTC) X-FDA: 75842913720.06.bulb46_373b1679a9500 X-HE-Tag: bulb46_373b1679a9500 X-Filterd-Recvd-Size: 2588 Received: from Galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) by imf47.hostedemail.com (Postfix) with ESMTP for ; Tue, 20 Aug 2019 13:39:39 +0000 (UTC) Received: from p5de0b6c5.dip0.t-ipconnect.de ([93.224.182.197] helo=nanos) by Galois.linutronix.de with esmtpsa (TLS1.2:DHE_RSA_AES_256_CBC_SHA256:256) (Exim 4.80) (envelope-from ) id 1i04MI-0006WU-TW; Tue, 20 Aug 2019 15:39:35 +0200 Date: Tue, 20 Aug 2019 15:39:34 +0200 (CEST) From: Thomas Gleixner To: Song Liu cc: Peter Zijlstra , "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" , Kernel Team , "stable@vger.kernel.org" , Joerg Roedel , Dave Hansen , Andy Lutomirski Subject: Re: [PATCH] x86/mm/pti: in pti_clone_pgtable() don't increase addr by PUD_SIZE In-Reply-To: <44EA504D-2388-49EF-A807-B9712903B146@fb.com> Message-ID: References: <20190820075128.2912224-1-songliubraving@fb.com> <20190820100055.GI2332@hirez.programming.kicks-ass.net> <44EA504D-2388-49EF-A807-B9712903B146@fb.com> User-Agent: Alpine 2.21 (DEB 202 2017-01-01) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 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 Tue, 20 Aug 2019, Song Liu wrote: > > On Aug 20, 2019, at 4:16 AM, Thomas Gleixner wrote: > > > > On Tue, 20 Aug 2019, Peter Zijlstra wrote: > >> What that code wants to do is skip to the end of the pud, a pmd_size > >> increase will not do that. And right below this, there's a second > >> instance of this exact pattern. > >> > >> Did I get the below right? > >> > >> --- > >> diff --git a/arch/x86/mm/pti.c b/arch/x86/mm/pti.c > >> index b196524759ec..32b20b3cb227 100644 > >> --- a/arch/x86/mm/pti.c > >> +++ b/arch/x86/mm/pti.c > >> @@ -330,12 +330,14 @@ pti_clone_pgtable(unsigned long start, unsigned long end, > >> > >> pud = pud_offset(p4d, addr); > >> if (pud_none(*pud)) { > >> + addr &= PUD_MASK; > >> addr += PUD_SIZE; > > > > round_up(addr, PUD_SIZE); > > I guess we need "round_up(addr + PMD_SIZE, PUD_SIZE)". Right you are.