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=-10.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 637E5C433F5 for ; Thu, 23 Sep 2021 23:17:42 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id E3EB06124E for ; Thu, 23 Sep 2021 23:17:41 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org E3EB06124E 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=kvack.org Received: by kanga.kvack.org (Postfix) id 2CEA16B006C; Thu, 23 Sep 2021 19:17:41 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 27D906B0071; Thu, 23 Sep 2021 19:17:41 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 1456E900002; Thu, 23 Sep 2021 19:17:41 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0130.hostedemail.com [216.40.44.130]) by kanga.kvack.org (Postfix) with ESMTP id 0635A6B006C for ; Thu, 23 Sep 2021 19:17:41 -0400 (EDT) Received: from smtpin28.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 977CD1828B309 for ; Thu, 23 Sep 2021 23:17:40 +0000 (UTC) X-FDA: 78620402280.28.3B21DA0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf25.hostedemail.com (Postfix) with ESMTP id 44ABEB000181 for ; Thu, 23 Sep 2021 23:17:40 +0000 (UTC) Received: by mail.kernel.org (Postfix) with ESMTPSA id 3A9A160E94; Thu, 23 Sep 2021 23:17:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1632439059; bh=aovSY1+j/p4VcwH3XgkVFJ6AKhHLQs9U16f85Ij55u4=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=HreHvNj6W8lCJitqQAcOFJ/XWQr05sDs5HuQ7X66Vdf3gsUyHKgag3fA4dbfRUa3P VzD1idLDZbHhW7AIY659g+7nJvtfq7baXXVHZ3F2rXF4VVoOwIm9kOkrCPRfqi+/zi vPKY14Gxk0h1tlB+Ejl//3om6d2xMbyc1vVDQHS8= Date: Thu, 23 Sep 2021 16:17:38 -0700 From: Andrew Morton To: Qi Zheng Cc: naoya.horiguchi@nec.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, songmuchun@bytedance.com Subject: Re: [PATCH] mm/memory_failure: Fix the missing pte_unmap() call Message-Id: <20210923161738.990b61933c96df78bc1bf96d@linux-foundation.org> In-Reply-To: <20210923122642.4999-1-zhengqi.arch@bytedance.com> References: <20210923122642.4999-1-zhengqi.arch@bytedance.com> X-Mailer: Sylpheed 3.5.1 (GTK+ 2.24.31; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 44ABEB000181 X-Stat-Signature: p84zjx1err31dar47yfoferknxjrecqg Authentication-Results: imf25.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b=HreHvNj6; dmarc=none; spf=pass (imf25.hostedemail.com: domain of akpm@linux-foundation.org designates 198.145.29.99 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org X-HE-Tag: 1632439060-802450 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: 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? +++ 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; } _