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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 87FCEC433F5 for ; Fri, 24 Sep 2021 00:31:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 60A8961216 for ; Fri, 24 Sep 2021 00:31:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243658AbhIXAcp (ORCPT ); Thu, 23 Sep 2021 20:32:45 -0400 Received: from out2.migadu.com ([188.165.223.204]:32176 "EHLO out2.migadu.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232143AbhIXAco (ORCPT ); Thu, 23 Sep 2021 20:32:44 -0400 Date: Fri, 24 Sep 2021 09:31:02 +0900 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1632443470; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=zjfLAfWSo5szBRHYcbTSavPrNdYVRR33+yO7EWtRlRM=; b=MFbSUTUXaAniZtOK418Rkutp3rZOsdXuttey/8upAfNJ+HTu+GvLj2uXRO9GaGdBI5BxLP C5qyaUPxFM0NgqvT2SFkRcW4jUAkU1iYC5KyGA/Lb4AKyqdGRwFYJ4+mQdau4YOVOIRa75 8yXS+pJu1cNwmzW8Y50F2WhWIY9my8o= X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Naoya Horiguchi To: Andrew Morton Cc: Qi Zheng , 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: <20210924003102.GA974757@u2004> References: <20210923122642.4999-1-zhengqi.arch@bytedance.com> <20210923161738.990b61933c96df78bc1bf96d@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20210923161738.990b61933c96df78bc1bf96d@linux-foundation.org> X-Migadu-Flow: FLOW_OUT X-Migadu-Auth-User: naoya.horiguchi@linux.dev Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Sep 23, 2021 at 04:17:38PM -0700, 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? > > +++ 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: This neater one looks good to me. Acked-by: Naoya Horiguchi