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=-10.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,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 909A8C433F5 for ; Fri, 24 Sep 2021 02:24:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7068861108 for ; Fri, 24 Sep 2021 02:24:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243912AbhIXCZo (ORCPT ); Thu, 23 Sep 2021 22:25:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42546 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243850AbhIXCZn (ORCPT ); Thu, 23 Sep 2021 22:25:43 -0400 Received: from mail-pf1-x432.google.com (mail-pf1-x432.google.com [IPv6:2607:f8b0:4864:20::432]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 126B1C061574 for ; Thu, 23 Sep 2021 19:24:11 -0700 (PDT) Received: by mail-pf1-x432.google.com with SMTP id c1so7495594pfp.10 for ; Thu, 23 Sep 2021 19:24:11 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance-com.20210112.gappssmtp.com; s=20210112; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-transfer-encoding; bh=DBLPQkg/kO5ASFtfk+t/XeZTp3dTZPnTRFF3O4rADL4=; b=OeuIzFZdiPEedGDiO7PxecdOHaoDHoTfxluMloCmEd90h+Z9DyM5f2FZgVh5QNeyCe 0qcVxQtpMNz4GE7zwUPnwtd0fITYQXT8qttxxDOu3ZZxSb7OETT0cm/EvrJ2M8oB5X/b 8sojVxAqPBXbkki2p7e82AZx0EFik2lyIXgG4QqdI0puJIXfUCw5BQ0XIhO7r80bKLwX hqRqwnh24DK7qT5QOJCTX7i1nGo8KrRZ+W4luPiB4YxvJTWZVchK6ufD2jiwCwIlzDVq nk3E4JcR7Mem3HQOr+wHqlvGVlnViAaLOr0hWGRYMtNqTh35huChocYJQ37R8GDFYlvd ru9A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-transfer-encoding; bh=DBLPQkg/kO5ASFtfk+t/XeZTp3dTZPnTRFF3O4rADL4=; b=faYl1MCZwjKETza9pUo/0rGz+7R5cyGG2zVVx0yn/s+UUB4NjmTPSvy0YcjlKRUVkP s9wuFFXExOiSWTe7rbnK7lOGYalOLhZGnHu8c6Q4YtjNLmExJdpp1sDZvg9WELSefIM7 sldFZAG5RGlEqWcPyy3JyAH9bZLWWwJgYc1LVyfSvZxL5NVK+ukfyQ/WMbI8BoWCCKJq WPbmDM5lGeVEiJO/C4P1RB9T8YHcl2doXSwThtERfaYIpRKqx1Ei1pPMnfiO2Sz/Jdv4 8roRF2e2v1i0opUGFvhXgsKq1Nf9Hf6RmLtA3Lbkl1/iq4uyt1yycEplqdHAk6HZZFGl Wz3w== X-Gm-Message-State: AOAM533XC68oYAlRgNM4LCVqdHfW5iyJXG8P/ZniN08suteawNGZ6Plg GXphYUeKW4Gv0mkcsiIRSyvfvQ== X-Google-Smtp-Source: ABdhPJwrZpmVouPmoXMnwC2oolb/vsvPAPc9nLZvI0gmbK4/alFFziPzIc437ps2DG64MtjpEKOW1w== X-Received: by 2002:a63:ed17:: with SMTP id d23mr1703047pgi.29.1632450250572; Thu, 23 Sep 2021 19:24:10 -0700 (PDT) Received: from [10.255.74.217] ([139.177.225.249]) by smtp.gmail.com with ESMTPSA id q2sm10249656pjo.27.2021.09.23.19.24.08 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 23 Sep 2021 19:24:10 -0700 (PDT) Subject: Re: [PATCH] mm/memory_failure: Fix the missing pte_unmap() call To: Andrew Morton Cc: naoya.horiguchi@nec.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, songmuchun@bytedance.com References: <20210923122642.4999-1-zhengqi.arch@bytedance.com> <20210923161738.990b61933c96df78bc1bf96d@linux-foundation.org> From: Qi Zheng Message-ID: <2eca94ce-4e26-aff6-240d-39baf1a9cc36@bytedance.com> Date: Fri, 24 Sep 2021 10:24:06 +0800 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:78.0) Gecko/20100101 Thunderbird/78.14.0 MIME-Version: 1.0 In-Reply-To: <20210923161738.990b61933c96df78bc1bf96d@linux-foundation.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 9/24/21 7:17 AM, Andrew Morton wrote: > On Thu, 23 Sep 2021 20:26:42 +0800 Qi Zheng wrote: > >> The paired pte_unmap() call is missing before the >> dev_pagemap_mapping_shift() returns. So fix it. >> >> ... >> >> --- a/mm/memory-failure.c >> +++ b/mm/memory-failure.c >> @@ -306,6 +306,7 @@ static unsigned long dev_pagemap_mapping_shift(struct page *page, >> struct vm_area_struct *vma) >> { >> unsigned long address = vma_address(page, vma); >> + unsigned long ret = 0; >> pgd_t *pgd; >> p4d_t *p4d; >> pud_t *pud; >> @@ -330,10 +331,12 @@ static unsigned long dev_pagemap_mapping_shift(struct page *page, >> return PMD_SHIFT; >> pte = pte_offset_map(pmd, address); >> if (!pte_present(*pte)) >> - return 0; >> + goto unmap; >> if (pte_devmap(*pte)) >> - return PAGE_SHIFT; >> - return 0; >> + ret = PAGE_SHIFT; >> +unmap: >> + pte_unmap(pte); >> + return ret; >> } >> > > This is neater? Yes, and I see this neater version has merged into your mm tree, thanks. :) > > +++ a/mm/memory-failure.c > @@ -330,11 +330,8 @@ static unsigned long dev_pagemap_mapping > if (pmd_devmap(*pmd)) > return PMD_SHIFT; > pte = pte_offset_map(pmd, address); > - if (!pte_present(*pte)) > - goto unmap; > - if (pte_devmap(*pte)) > + if (pte_present(*pte) && pte_devmap(*pte)) > ret = PAGE_SHIFT; > -unmap: > pte_unmap(pte); > return ret; > } > _ >