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=-9.6 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,URIBL_BLOCKED,USER_AGENT_GIT 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 C09B3C352BE for ; Fri, 17 Apr 2020 10:32:02 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 8135221D94 for ; Fri, 17 Apr 2020 10:32:02 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="uQv0m/pp" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8135221D94 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 1F21C8E0008; Fri, 17 Apr 2020 06:32:02 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 1A2F08E0001; Fri, 17 Apr 2020 06:32:02 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 042E58E0008; Fri, 17 Apr 2020 06:32:01 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0038.hostedemail.com [216.40.44.38]) by kanga.kvack.org (Postfix) with ESMTP id DAAB98E0001 for ; Fri, 17 Apr 2020 06:32:01 -0400 (EDT) Received: from smtpin04.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 795CC180AD81D for ; Fri, 17 Apr 2020 10:32:01 +0000 (UTC) X-FDA: 76716981642.04.root81_4bd62f9349749 X-HE-Tag: root81_4bd62f9349749 X-Filterd-Recvd-Size: 3304 Received: from mail-pl1-f193.google.com (mail-pl1-f193.google.com [209.85.214.193]) by imf12.hostedemail.com (Postfix) with ESMTP for ; Fri, 17 Apr 2020 10:32:01 +0000 (UTC) Received: by mail-pl1-f193.google.com with SMTP id t4so811031plq.12 for ; Fri, 17 Apr 2020 03:32:00 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id; bh=lBs7XJjdW6ybVsxQ1bUex8OGCP5715A0ilIyUoP2WqM=; b=uQv0m/ppzmvrXp3SlavP+Gz+33S92uHGslSklWCF6dWdusgjAjMRwicz08wy9BL8oq ExSQoN2yCLCOwnxV9MaXR+C87iHjI0pRpVNLZJ9XtFxhG20eajQ0I+aHkOnBHx1I5qtl J4/AJxTHBGjCkHYfhYiaLu+zZWc9KpOPb6AW9EFHYiC0ux+Xe9jZAFUL3zcvVhFzY+qk ikAzWOf23r6bohXLAZbTbC5Gy33uup6I7UAtOEAzgDKULFCd8hH0zZhjR3McN4iC+VET HJuJX3mROmQovh3tdD8y/+v7vNyEfreEA7iZ120hBkJRv9xPO0wKCMb1HXvWHdQAHlQ4 2fKA== 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; bh=lBs7XJjdW6ybVsxQ1bUex8OGCP5715A0ilIyUoP2WqM=; b=l6QfuI3CzDV2E0AvpYAc2KW7mmhzgTeRnBolwbw8Bkr5buSDwF+37mntFWXkhBLFQr Xhz+4F8o545F1lPQhY9f246GqAP5JEip3FIueJVrD07fG2hN80WauBWdr3sK4eXPYgzv 9pmYzqd4M1uRdJU1Y+vDM+MEu+JsJjXKXPQJrdghrfCHUNQ1NDJ0Ty4MZZ42DBhDDWmP nHgI+pJZk934YCOY7y9psEqe3LhIOrCLj5zyV2P8K+kCZicsv3egVclvRzbOoTY1I+gi 92qZkgfmXpn0YzncaqJYLbX6OnkqBUn1FrLH/bax85vHx2FcQNUBQHhiZMRYiPDMzH9n FIKQ== X-Gm-Message-State: AGi0Puap4yC5zt3v+sLEynVScv+bTqESrx6aQWb1Yw9v0kaxW2y5jIXz pzAbumBRVFdmMU4cC8VqKGM= X-Google-Smtp-Source: APiQypIzCbaw46a6YNYIAKtmsKQ4tV2vgRbbrKr6/fImlbSu0YJEEjQU4cxBJcS2NWBQf2ouP0bk5w== X-Received: by 2002:a17:902:cb97:: with SMTP id d23mr2852586ply.232.1587119520084; Fri, 17 Apr 2020 03:32:00 -0700 (PDT) Received: from localhost ([43.224.245.179]) by smtp.gmail.com with ESMTPSA id f9sm5280922pjt.45.2020.04.17.03.31.58 (version=TLS1_2 cipher=AES128-SHA bits=128/128); Fri, 17 Apr 2020 03:31:59 -0700 (PDT) From: qiwuchen55@gmail.com To: akpm@linux-foundation.org Cc: linux-mm@kvack.org, chenqiwu Subject: [PATCH] mm/memory: add refcount for special mapping page in copy_one_pte() Date: Fri, 17 Apr 2020 18:31:54 +0800 Message-Id: <1587119514-29679-1-git-send-email-qiwuchen55@gmail.com> X-Mailer: git-send-email 1.9.1 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000840, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: From: chenqiwu If we get a special mapping page like device mapping page or zero page when copy_one_pte, it's necessary add the page refcount count. Signed-off-by: chenqiwu --- mm/memory.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/mm/memory.c b/mm/memory.c index f703fe8..a57975a 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -802,8 +802,9 @@ struct page *vm_normal_page_pmd(struct vm_area_struct *vma, unsigned long addr, get_page(page); page_dup_rmap(page, false); rss[mm_counter(page)]++; - } else if (pte_devmap(pte)) { + } else if (pte_devmap(pte) || is_zero_pfn(pte_pfn(pte))) { page = pte_page(pte); + get_page(page); } out_set_pte: -- 1.9.1