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=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 DF201C43381 for ; Tue, 26 Feb 2019 11:18:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B310A2146F for ; Tue, 26 Feb 2019 11:18:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727971AbfBZLSu (ORCPT ); Tue, 26 Feb 2019 06:18:50 -0500 Received: from szxga07-in.huawei.com ([45.249.212.35]:36210 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726194AbfBZLSt (ORCPT ); Tue, 26 Feb 2019 06:18:49 -0500 Received: from DGGEMS407-HUB.china.huawei.com (unknown [172.30.72.59]) by Forcepoint Email with ESMTP id 9E33340D3053976F4C99; Tue, 26 Feb 2019 19:18:46 +0800 (CST) Received: from linux-ibm.site (10.175.102.37) by DGGEMS407-HUB.china.huawei.com (10.3.19.207) with Microsoft SMTP Server id 14.3.408.0; Tue, 26 Feb 2019 19:18:41 +0800 From: zhong jiang To: , CC: , , , , Subject: [PATCH] mm: hwpoison: fix thp split handing in soft_offline_in_use_page() Date: Tue, 26 Feb 2019 19:18:00 +0800 Message-ID: <1551179880-65331-1-git-send-email-zhongjiang@huawei.com> X-Mailer: git-send-email 1.7.12.4 MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.175.102.37] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: zhongjiang When soft_offline_in_use_page() runs on a thp tail page after pmd is plit, we trigger the following VM_BUG_ON_PAGE(): Memory failure: 0x3755ff: non anonymous thp __get_any_page: 0x3755ff: unknown zero refcount page type 2fffff80000000 Soft offlining pfn 0x34d805 at process virtual address 0x20fff000 page:ffffea000d360140 count:0 mapcount:0 mapping:0000000000000000 index:0x1 flags: 0x2fffff80000000() raw: 002fffff80000000 ffffea000d360108 ffffea000d360188 0000000000000000 raw: 0000000000000001 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: VM_BUG_ON_PAGE(page_ref_count(page) == 0) ------------[ cut here ]------------ kernel BUG at ./include/linux/mm.h:519! soft_offline_in_use_page() passed refcount and page lock from tail page to head page, which is not needed because we can pass any subpage to split_huge_page(). Cc: [4.5+] Signed-off-by: zhongjiang --- mm/memory-failure.c | 14 ++++++-------- 1 file changed, 6 insertions(+), 8 deletions(-) diff --git a/mm/memory-failure.c b/mm/memory-failure.c index d9b8a24..6edc6db 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -1823,19 +1823,17 @@ static int soft_offline_in_use_page(struct page *page, int flags) struct page *hpage = compound_head(page); if (!PageHuge(page) && PageTransHuge(hpage)) { - lock_page(hpage); - if (!PageAnon(hpage) || unlikely(split_huge_page(hpage))) { - unlock_page(hpage); - if (!PageAnon(hpage)) + lock_page(page); + if (!PageAnon(page) || unlikely(split_huge_page(page))) { + unlock_page(page); + if (!PageAnon(page)) pr_info("soft offline: %#lx: non anonymous thp\n", page_to_pfn(page)); else pr_info("soft offline: %#lx: thp split failed\n", page_to_pfn(page)); - put_hwpoison_page(hpage); + put_hwpoison_page(page); return -EBUSY; } - unlock_page(hpage); - get_hwpoison_page(page); - put_hwpoison_page(hpage); + unlock_page(page); } /* -- 1.7.12.4