From patchwork Mon Jun 15 12:57:57 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christophe Leroy X-Patchwork-Id: 11604871 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 1D3C4912 for ; Mon, 15 Jun 2020 12:58:04 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id E77C72078A for ; Mon, 15 Jun 2020 12:58:03 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E77C72078A Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=csgroup.eu Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id C84566B0003; Mon, 15 Jun 2020 08:58:00 -0400 (EDT) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id B1E4A6B0007; Mon, 15 Jun 2020 08:58:00 -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 948BE6B0005; Mon, 15 Jun 2020 08:58:00 -0400 (EDT) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0151.hostedemail.com [216.40.44.151]) by kanga.kvack.org (Postfix) with ESMTP id 71F9B6B0002 for ; Mon, 15 Jun 2020 08:58:00 -0400 (EDT) Received: from smtpin21.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id E03B4181AC9C6 for ; Mon, 15 Jun 2020 12:57:59 +0000 (UTC) X-FDA: 76931448678.21.kite20_4017b2d26df6 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin21.hostedemail.com (Postfix) with ESMTP id B197C180442C3 for ; Mon, 15 Jun 2020 12:57:59 +0000 (UTC) X-Spam-Summary: 2,0,0,d7d8de1af68e5ef1,d41d8cd98f00b204,christophe.leroy@csgroup.eu,,RULES_HIT:41:355:379:800:960:973:988:989:1260:1261:1345:1359:1534:1539:1711:1714:1730:1747:1777:1792:2393:2559:2562:2693:3138:3139:3140:3141:3142:3350:3872:3876:4321:5007:6261:8634:10004:11026:11527:11658:11914:12048:12297:12438:12555:12679:12895:13069:13161:13229:13311:13357:14096:14181:14384:14394:14721:21080:21451:21627:21990:30054:30055,0,RBL:93.17.236.30:@csgroup.eu:.lbl8.mailshell.net-64.100.201.201 62.2.5.100,CacheIP:none,Bayesian:0.5,0.5,0.5,Netcheck:none,DomainCache:0,MSF:not bulk,SPF:fp,MSBL:0,DNSBL:neutral,Custom_rules:0:0:0,LFtime:24,LUA_SUMMARY:none X-HE-Tag: kite20_4017b2d26df6 X-Filterd-Recvd-Size: 2948 Received: from pegase1.c-s.fr (pegase1.c-s.fr [93.17.236.30]) by imf42.hostedemail.com (Postfix) with ESMTP for ; Mon, 15 Jun 2020 12:57:59 +0000 (UTC) Received: from localhost (mailhub1-int [192.168.12.234]) by localhost (Postfix) with ESMTP id 49lrwP0gRdz9v1fj; Mon, 15 Jun 2020 14:57:57 +0200 (CEST) X-Virus-Scanned: Debian amavisd-new at c-s.fr Received: from pegase1.c-s.fr ([192.168.12.234]) by localhost (pegase1.c-s.fr [192.168.12.234]) (amavisd-new, port 10024) with ESMTP id 8xehc990nQE6; Mon, 15 Jun 2020 14:57:57 +0200 (CEST) Received: from messagerie.si.c-s.fr (messagerie.si.c-s.fr [192.168.25.192]) by pegase1.c-s.fr (Postfix) with ESMTP id 49lrwN70rkz9v1fM; Mon, 15 Jun 2020 14:57:56 +0200 (CEST) Received: from localhost (localhost [127.0.0.1]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 6C7A08B792; Mon, 15 Jun 2020 14:57:57 +0200 (CEST) X-Virus-Scanned: amavisd-new at c-s.fr Received: from messagerie.si.c-s.fr ([127.0.0.1]) by localhost (messagerie.si.c-s.fr [127.0.0.1]) (amavisd-new, port 10023) with ESMTP id kNn5IA9igqIr; Mon, 15 Jun 2020 14:57:57 +0200 (CEST) Received: from pc16570vm.idsi0.si.c-s.fr (po15451.idsi0.si.c-s.fr [172.25.230.104]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 23A048B75F; Mon, 15 Jun 2020 14:57:57 +0200 (CEST) Received: by pc16570vm.idsi0.si.c-s.fr (Postfix, from userid 0) id 1921265B0E; Mon, 15 Jun 2020 12:57:57 +0000 (UTC) Message-Id: In-Reply-To: References: From: Christophe Leroy Subject: [PATCH 1/3] mm/gup: Use huge_ptep_get() in gup_hugepte() To: Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , Will Deacon , Andrew Morton , "Peter Zijlstra (Intel)" Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-mm@kvack.org Date: Mon, 15 Jun 2020 12:57:57 +0000 (UTC) X-Rspamd-Queue-Id: B197C180442C3 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam04 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: gup_hugepte() reads hugepage table entries, it can't read them directly, huge_ptep_get() must be used. Fixes: 2ab3a0a02905 ("READ_ONCE: Enforce atomicity for {READ,WRITE}_ONCE() memory accesses") Cc: Will Deacon Signed-off-by: Christophe Leroy --- mm/gup.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/gup.c b/mm/gup.c index de9e36262ccb..761df4944ef5 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -2425,7 +2425,7 @@ static int gup_hugepte(pte_t *ptep, unsigned long sz, unsigned long addr, if (pte_end < end) end = pte_end; - pte = READ_ONCE(*ptep); + pte = huge_ptep_get(ptep); if (!pte_access_permitted(pte, flags & FOLL_WRITE)) return 0;