From patchwork Wed Mar 18 05:01:19 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Anshuman Khandual X-Patchwork-Id: 11444529 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 703AA159A for ; Wed, 18 Mar 2020 05:01:45 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 3F95020753 for ; Wed, 18 Mar 2020 05:01:45 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3F95020753 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 654DC6B0003; Wed, 18 Mar 2020 01:01:44 -0400 (EDT) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id 605CE6B0006; Wed, 18 Mar 2020 01:01:44 -0400 (EDT) X-Original-To: int-list-linux-mm@kvack.org X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 51A7A6B0007; Wed, 18 Mar 2020 01:01:44 -0400 (EDT) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0096.hostedemail.com [216.40.44.96]) by kanga.kvack.org (Postfix) with ESMTP id 36D9F6B0003 for ; Wed, 18 Mar 2020 01:01:44 -0400 (EDT) Received: from smtpin18.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 641AE181AEF00 for ; Wed, 18 Mar 2020 05:01:44 +0000 (UTC) X-FDA: 76607285328.18.bait91_66724022d1652 X-Spam-Summary: 2,0,0,a75e7cd0678a8b84,d41d8cd98f00b204,anshuman.khandual@arm.com,,RULES_HIT:41:355:379:541:800:960:973:988:989:1260:1261:1345:1431:1437:1534:1541:1711:1730:1747:1777:1792:1963:2393:2559:2562:2693:3138:3139:3140:3141:3142:3167:3353:3865:3868:3870:3871:3872:4250:4321:5007:6119:6261:8634:10004:11026:11232:11657:11658:11914:12043:12297:12555:12895:12986:13069:13311:13357:13846:14096:14181:14384:14394:14721:21063:21080:21451:21627:21796:21990:30036:30054:30064:30070,0,RBL:217.140.110.172:@arm.com:.lbl8.mailshell.net-62.14.0.100 64.201.201.201,CacheIP:none,Bayesian:0.5,0.5,0.5,Netcheck:none,DomainCache:0,MSF:not bulk,SPF:fp,MSBL:0,DNSBL:none,Custom_rules:0:0:0,LFtime:24,LUA_SUMMARY:none X-HE-Tag: bait91_66724022d1652 X-Filterd-Recvd-Size: 3076 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by imf38.hostedemail.com (Postfix) with ESMTP for ; Wed, 18 Mar 2020 05:01:43 +0000 (UTC) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 9C26D1FB; Tue, 17 Mar 2020 22:01:42 -0700 (PDT) Received: from p8cg001049571a15.arm.com (unknown [10.163.1.20]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 7D0353F67D; Tue, 17 Mar 2020 22:01:38 -0700 (PDT) From: Anshuman Khandual To: linux-mm@kvack.org Cc: Anshuman Khandual , Thomas Gleixner , Ingo Molnar , Borislav Petkov , "H. Peter Anvin" , Dave Hansen , Andrew Morton , x86@kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] x86/mm: Make pud_present() check _PAGE_PROTNONE and _PAGE_PSE as well Date: Wed, 18 Mar 2020 10:31:19 +0530 Message-Id: <1584507679-11976-1-git-send-email-anshuman.khandual@arm.com> X-Mailer: git-send-email 2.7.4 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: pud_present() should also check _PAGE_PROTNONE and _PAGE_PSE bits like in case pmd_present(). This makes a PUD entry test positive for pud_present() after getting invalidated with pud_mknotpresent(), hence standardizing the semantics with PMD helpers. Cc: Thomas Gleixner Cc: Ingo Molnar Cc: Borislav Petkov Cc: "H. Peter Anvin" Cc: Dave Hansen Cc: Andrew Morton Cc: x86@kernel.org Cc: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Anshuman Khandual --- Even though pud_mknotpresent() is not used any where currently, there is a discrepancy between PMD and PUD. WARN_ON(!pud_present(pud_mknotpresent(pud_mkhuge(pud)))) -> Fail WARN_ON(!pmd_present(pmd_mknotpresent(pmd_mkhuge(pmd)))) -> Pass Though pud_mknotpresent() currently clears _PAGE_PROTNONE, pud_present() does not check it. This change fixes both inconsistencies. This has been build and boot tested on x86. arch/x86/include/asm/pgtable.h | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h index 7e118660bbd9..8adf1d00b506 100644 --- a/arch/x86/include/asm/pgtable.h +++ b/arch/x86/include/asm/pgtable.h @@ -857,7 +857,13 @@ static inline int pud_none(pud_t pud) static inline int pud_present(pud_t pud) { - return pud_flags(pud) & _PAGE_PRESENT; + /* + * Checking for _PAGE_PSE is needed too because + * split_huge_page will temporarily clear the present bit (but + * the _PAGE_PSE flag will remain set at all times while the + * _PAGE_PRESENT bit is clear). + */ + return pud_flags(pud) & (_PAGE_PRESENT | _PAGE_PROTNONE | _PAGE_PSE); } static inline unsigned long pud_page_vaddr(pud_t pud)