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=-9.7 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 E780CC5DF60 for ; Fri, 8 Nov 2019 13:02:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BAE76206A3 for ; Fri, 8 Nov 2019 13:02:56 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="ICNCj4oQ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730968AbfKHNC2 (ORCPT ); Fri, 8 Nov 2019 08:02:28 -0500 Received: from mail-wm1-f67.google.com ([209.85.128.67]:55294 "EHLO mail-wm1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730813AbfKHNC1 (ORCPT ); Fri, 8 Nov 2019 08:02:27 -0500 Received: by mail-wm1-f67.google.com with SMTP id z26so6099201wmi.4 for ; Fri, 08 Nov 2019 05:02:26 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=HPUhRkeh9B8kThmSnedxU9rFzUdfov5nG5Mv0o35La0=; b=ICNCj4oQpjkXiCCB0Lw81MOO95U7sKM5Kz8xpYLhoYoWOKMuZcvUoxtjKKt2jzSR7j B5OcXsUWasqOl0HZX88fjBqFaXzGpC64lEeWV8KES7451owMHRVYqpNcYa8q1l9gkETF br3nnWpAHxXNr8f4eAl6i72qi5FXxL1bDa0YlPKuOwRhzyLe8wDnrcT2pDYGNVQd7Ocs 9dotwsT9e/h2pKNp3/4UkbAKNYNPk8pwxD0kVfAtblBd7oSiuVGpBsOJN0Y65EQQxRTI uZOwvTSHB605E3E1LdbBCOnGxJN0/arC/Pkpx3ucDiXxdTXVSrX+eu8y1K+aMLNYeIaP bzpA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=HPUhRkeh9B8kThmSnedxU9rFzUdfov5nG5Mv0o35La0=; b=GoXhV3ChERbgWR4D9PMvfgQGRNl1Humo8KGCdGMzsJthNC5N2tc3yb/ph+LL/rF6Qj A3XKE4BxGiYONmxoue/T//2HwCFvKm/W+8Ouf6oazRE1DYNzIWHxUfaheUyEhu8Ohcsk HqGOjkTonkzG8mNwy1BnfMRacu58vJr67k/2sY76NJc/UeGQeeL+Duc9VZNLIxTWPGBE Yf442+1mp2pKEgM45pIQWlMYNQqumSfRCNV+iThGGwilM7BuRCLce7rr6f/R0FrC/M2A otjffZV6hNbwaHk5+jFr/bBBwakx8pYYXN92h5Su53JBQGmxUMMfy66wAO5gjxdUvvoR +TuA== X-Gm-Message-State: APjAAAVvmXsJsrcyaTa37ffCuT3XJ4m4AMYzTTCkt1zdFnzabjokzRbt mO7bsB8n1cBcPc8on2jjiIQ= X-Google-Smtp-Source: APXvYqwMwb1ZXdjI8mkjWvVMXye8zLX+KycPXPXcNRDkji1B7sfa2iwgQH1CXXp9MvDKphQ3FqPzNw== X-Received: by 2002:a1c:9d07:: with SMTP id g7mr8198735wme.53.1573218145734; Fri, 08 Nov 2019 05:02:25 -0800 (PST) Received: from binjiang-hz-dhcp091254.china.nsn-net.net ([131.228.2.20]) by smtp.gmail.com with ESMTPSA id b8sm5873976wrt.39.2019.11.08.05.02.23 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 08 Nov 2019 05:02:25 -0800 (PST) From: Li Xinhai To: linux-mm@kvack.org Cc: Andrew Morton , Naoya Horiguchi , Michal Hocko , Vlastimil Babka , Hugh Dickins , linux-man Subject: [PATCH v4 1/2] mm: Check range first in queue_pages_test_walk Date: Fri, 8 Nov 2019 21:01:43 +0800 Message-Id: <1573218104-11021-2-git-send-email-lixinhai.lxh@gmail.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1573218104-11021-1-git-send-email-lixinhai.lxh@gmail.com> References: <1573218104-11021-1-git-send-email-lixinhai.lxh@gmail.com> Sender: linux-man-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-man@vger.kernel.org Checking unmapped hole and updating the previous vma must be handled first, otherwise the unmapped hole could be calculated from a wrong previous vma. Several commits were relevant to this error: commit 6f4576e3687b ("mempolicy: apply page table walker on queue_pages_range()"), This commit was correct, the VM_PFNMAP check was after updateing previous vma commit 48684a65b4e3 (mm: pagewalk: fix misbehavior of walk_page_range for vma(VM_PFNMAP)), This commit added VM_PFNMAP check before updateing previous vma. Then, there were two VM_PFNMAP check did same thing twice. commit acda0c334028 (mm/mempolicy.c: get rid of duplicated check for vma(VM_PFNMAP) in queue_page s_range()), This commit tried to fix the duplicated VM_PFNMAP check, but it wrongly removed the one which was after updateing vma. Fixes: acda0c334028 (mm/mempolicy.c: get rid of duplicated check for vma(VM_PFNMAP) in queue_page s_range()) Cc: Andrew Morton Cc: Naoya Horiguchi Cc: Michal Hocko Cc: Vlastimil Babka Cc: Hugh Dickins Cc: linux-man Signed-off-by: Li Xinhai --- mm/mempolicy.c | 19 ++++++++++--------- 1 file changed, 10 insertions(+), 9 deletions(-) diff --git a/mm/mempolicy.c b/mm/mempolicy.c index 4ae967b..807f06f 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -618,6 +618,16 @@ static int queue_pages_test_walk(unsigned long start, unsigned long end, unsigned long endvma = vma->vm_end; unsigned long flags = qp->flags; + /* range check first */ + if (!(flags & MPOL_MF_DISCONTIG_OK)) { + if (!vma->vm_next && vma->vm_end < end) + return -EFAULT; + if (qp->prev && qp->prev->vm_end < vma->vm_start) + return -EFAULT; + } + + qp->prev = vma; + /* * Need check MPOL_MF_STRICT to return -EIO if possible * regardless of vma_migratable @@ -631,15 +641,6 @@ static int queue_pages_test_walk(unsigned long start, unsigned long end, if (vma->vm_start > start) start = vma->vm_start; - if (!(flags & MPOL_MF_DISCONTIG_OK)) { - if (!vma->vm_next && vma->vm_end < end) - return -EFAULT; - if (qp->prev && qp->prev->vm_end < vma->vm_start) - return -EFAULT; - } - - qp->prev = vma; - if (flags & MPOL_MF_LAZY) { /* Similar to task_numa_work, skip inaccessible VMAs */ if (!is_vm_hugetlb_page(vma) && -- 1.8.3.1