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,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 C5500C4707F for ; Tue, 25 May 2021 23:46:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9BD6361404 for ; Tue, 25 May 2021 23:46:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231982AbhEYXre (ORCPT ); Tue, 25 May 2021 19:47:34 -0400 Received: from mail.kernel.org ([198.145.29.99]:42276 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231441AbhEYXrd (ORCPT ); Tue, 25 May 2021 19:47:33 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id F086B60FDC; Tue, 25 May 2021 23:46:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1621986363; bh=u5dH1eG4eFhS8UxG/M0Z7iVWLOq6bt7ilq7ongIgx3g=; h=Date:From:To:Subject:From; b=hAddtAm8ydsjJE1NxjxNMApImJIRP59ttrMM2nTCX/dUwcRFt4s1I3q8CXKV0o7Sj Wkb8KNGSguAs44u2u/XYMYYto6hfU+0JTAvCISPhbp6ei49GUB4pavEYLQkTLjLBhg ptObLLwrE0eOj30UhSACYvy9F7e85pgP1gojGf0U= Date: Tue, 25 May 2021 16:46:02 -0700 From: akpm@linux-foundation.org To: mhocko@suse.com, mike.kravetz@oracle.com, mm-commits@vger.kernel.org, naoya.horiguchi@nec.com, songmuchun@bytedance.com, stable@vger.kernel.org, tony.luck@intel.com Subject: [to-be-updated] mmhwpoison-fix-race-with-hugetlb-page-allocation.patch removed from -mm tree Message-ID: <20210525234602.5UKGJV5W8%akpm@linux-foundation.org> User-Agent: s-nail v14.8.16 Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org The patch titled Subject: mm,hwpoison: fix race with hugetlb page allocation has been removed from the -mm tree. Its filename was mmhwpoison-fix-race-with-hugetlb-page-allocation.patch This patch was dropped because an updated version will be merged ------------------------------------------------------ From: Naoya Horiguchi Subject: mm,hwpoison: fix race with hugetlb page allocation When hugetlb page fault (under overcommitting situation) and memory_failure() race, VM_BUG_ON_PAGE() is triggered by the following race: CPU0: CPU1: gather_surplus_pages() page = alloc_surplus_huge_page() memory_failure_hugetlb() get_hwpoison_page(page) __get_hwpoison_page(page) get_page_unless_zero(page) zero = put_page_testzero(page) VM_BUG_ON_PAGE(!zero, page) enqueue_huge_page(h, page) put_page(page) __get_hwpoison_page() only checks the page refcount before taking an additional one for memory error handling, which is wrong because there's a time window where compound pages have non-zero refcount during initialization. So make __get_hwpoison_page() check page status a bit more for hugetlb pages. Link: https://lkml.kernel.org/r/20210518231259.2553203-2-nao.horiguchi@gmail.com Fixes: ead07f6a867b ("mm/memory-failure: introduce get_hwpoison_page() for consistent refcount handling") Signed-off-by: Naoya Horiguchi Reported-by: Muchun Song Cc: Mike Kravetz Cc: Michal Hocko Cc: Tony Luck Cc: [5.12+] Signed-off-by: Andrew Morton --- include/linux/hugetlb.h | 6 ++++++ mm/hugetlb.c | 15 +++++++++++++++ mm/memory-failure.c | 8 +++++++- 3 files changed, 28 insertions(+), 1 deletion(-) --- a/include/linux/hugetlb.h~mmhwpoison-fix-race-with-hugetlb-page-allocation +++ a/include/linux/hugetlb.h @@ -149,6 +149,7 @@ bool hugetlb_reserve_pages(struct inode long hugetlb_unreserve_pages(struct inode *inode, long start, long end, long freed); bool isolate_huge_page(struct page *page, struct list_head *list); +int get_hwpoison_huge_page(struct page *page, bool *hugetlb); void putback_active_hugepage(struct page *page); void move_hugetlb_state(struct page *oldpage, struct page *newpage, int reason); void free_huge_page(struct page *page); @@ -339,6 +340,11 @@ static inline bool isolate_huge_page(str return false; } +static inline int get_hwpoison_huge_page(struct page *page, bool *hugetlb) +{ + return 0; +} + static inline void putback_active_hugepage(struct page *page) { } --- a/mm/hugetlb.c~mmhwpoison-fix-race-with-hugetlb-page-allocation +++ a/mm/hugetlb.c @@ -5847,6 +5847,21 @@ unlock: return ret; } +int get_hwpoison_huge_page(struct page *page, bool *hugetlb) +{ + int ret = 0; + + *hugetlb = false; + spin_lock_irq(&hugetlb_lock); + if (PageHeadHuge(page)) { + *hugetlb = true; + if (HPageFreed(page) || HPageMigratable(page)) + ret = get_page_unless_zero(page); + } + spin_unlock_irq(&hugetlb_lock); + return ret; +} + void putback_active_hugepage(struct page *page) { spin_lock_irq(&hugetlb_lock); --- a/mm/memory-failure.c~mmhwpoison-fix-race-with-hugetlb-page-allocation +++ a/mm/memory-failure.c @@ -959,8 +959,14 @@ static int page_action(struct page_state static int __get_hwpoison_page(struct page *page) { struct page *head = compound_head(page); + int ret = 0; + bool hugetlb = false; - if (!PageHuge(head) && PageTransHuge(head)) { + ret = get_hwpoison_huge_page(head, &hugetlb); + if (hugetlb) + return ret; + + if (PageTransHuge(head)) { /* * Non anonymous thp exists only in allocation/free time. We * can't handle such a case correctly, so let's give it up. _ Patches currently in -mm which might be from naoya.horiguchi@nec.com are mmhwpoison-make-get_hwpoison_page-call-get_any_page.patch mmhwpoison-send-sigbus-with-error-virutal-address.patch