From patchwork Fri Jan 31 06:12:10 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrew Morton X-Patchwork-Id: 11359153 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 86EA613A4 for ; Fri, 31 Jan 2020 06:12:14 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 4890D20663 for ; Fri, 31 Jan 2020 06:12:14 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="IcuuNXLx" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4890D20663 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 411166B04E8; Fri, 31 Jan 2020 01:12:13 -0500 (EST) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id 399C56B04E9; Fri, 31 Jan 2020 01:12:13 -0500 (EST) 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 28B3A6B04EA; Fri, 31 Jan 2020 01:12:13 -0500 (EST) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0125.hostedemail.com [216.40.44.125]) by kanga.kvack.org (Postfix) with ESMTP id 10B906B04E8 for ; Fri, 31 Jan 2020 01:12:13 -0500 (EST) Received: from smtpin29.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id C8CEC181AEF09 for ; Fri, 31 Jan 2020 06:12:12 +0000 (UTC) X-FDA: 76436909304.29.trade96_13491215d5224 X-Spam-Summary: 50,0,0,e6f8c9a6c4b7f02b,d41d8cd98f00b204,akpm@linux-foundation.org,:akpm@linux-foundation.org:aneesh.kumar@linux.ibm.com:hqjagain@gmail.com:jhubbard@nvidia.com::mm-commits@vger.kernel.org:n-horiguchi@ah.jp.nec.com:torvalds@linux-foundation.org,RULES_HIT:41:355:379:800:960:967:973:988:989:1260:1263:1345:1359:1381:1431:1437:1534:1541:1711:1730:1747:1777:1792:2393:2525:2560:2564:2682:2685:2859:2902:2933:2937:2939:2942:2945:2947:2951:2954:3022:3138:3139:3140:3141:3142:3352:3865:3866:3867:3868:3872:3874:3934:3936:3938:3941:3944:3947:3950:3953:3956:3959:4321:4605:5007:6261:6653:7514:7576:7903:9025:9391:9545:10004:10913:11026:11658:11914:12043:12048:12297:12438:12517:12519:12555:12679:12783:12895:12986:13069:13311:13357:13846:14181:14384:14721:14777:14849:21060:21063:21080:21433:21451:21627:21788:21819:21939:21990:30054:30064:30070,0,RBL:error,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,LFt ime:2,LU X-HE-Tag: trade96_13491215d5224 X-Filterd-Recvd-Size: 3060 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf29.hostedemail.com (Postfix) with ESMTP for ; Fri, 31 Jan 2020 06:12:12 +0000 (UTC) Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 7F49F2082E; Fri, 31 Jan 2020 06:12:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1580451131; bh=/piSTUhOnTwRyPMULUDpwgh7W9g85Wvm/BfB6azDnEc=; h=Date:From:To:Subject:In-Reply-To:From; b=IcuuNXLxbxyt6YCyckTmwEuehZkwdb9//fxD1Bmpd/3ZM/05QatCqMQvQDOTmXhcY C4AzTUvci2+hmlFqJeiBU10GtJ5u5kPR8wVU6ogTWboNWApKMotWYGWNBJEF3JHt+v XNaGueqFlDTfIb4qmVYwjnYijFVFxdt011SfjEK8= Date: Thu, 30 Jan 2020 22:12:10 -0800 From: Andrew Morton To: akpm@linux-foundation.org, aneesh.kumar@linux.ibm.com, hqjagain@gmail.com, jhubbard@nvidia.com, linux-mm@kvack.org, mm-commits@vger.kernel.org, n-horiguchi@ah.jp.nec.com, torvalds@linux-foundation.org Subject: [patch 022/118] mm: fix gup_pud_range Message-ID: <20200131061210.S3lFMN09Q%akpm@linux-foundation.org> In-Reply-To: <20200130221021.5f0211c56346d5485af07923@linux-foundation.org> User-Agent: s-nail v14.8.16 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: From: Qiujun Huang Subject: mm: fix gup_pud_range sorry for not processing for a long time. I met it again. patch v1 https://lkml.org/lkml/2019/9/20/656 do_machine_check() do_memory_failure() memory_failure() hw_poison_user_mappings() try_to_unmap() pteval = swp_entry_to_pte(make_hwpoison_entry(subpage)); ...and now we have a swap entry that indicates that the page entry refers to a bad (and poisoned) page of memory, but gup_fast() at this level of the page table was ignoring swap entries, and incorrectly assuming that "!pxd_none() == valid and present". And this was not just a poisoned page problem, but a generaly swap entry problem. So, any swap entry type (device memory migration, numa migration, or just regular swapping) could lead to the same problem. Fix this by checking for pxd_present(), instead of pxd_none(). Link: http://lkml.kernel.org/r/1578479084-15508-1-git-send-email-hqjagain@gmail.com Signed-off-by: Qiujun Huang Cc: John Hubbard Cc: Aneesh Kumar K.V Cc: Naoya Horiguchi Signed-off-by: Andrew Morton --- mm/gup.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/mm/gup.c~mm-fix-gup_pud_range +++ a/mm/gup.c @@ -2237,7 +2237,7 @@ static int gup_pud_range(p4d_t p4d, unsi pud_t pud = READ_ONCE(*pudp); next = pud_addr_end(addr, end); - if (pud_none(pud)) + if (unlikely(!pud_present(pud))) return 0; if (unlikely(pud_huge(pud))) { if (!gup_huge_pud(pud, pudp, addr, next, flags,