From patchwork Thu Jan 14 10:35:12 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Muchun Song X-Patchwork-Id: 363504 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=-16.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable 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 2773AC43381 for ; Thu, 14 Jan 2021 10:41:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D21DF23A50 for ; Thu, 14 Jan 2021 10:41:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728786AbhANKjW (ORCPT ); Thu, 14 Jan 2021 05:39:22 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43434 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726458AbhANKjT (ORCPT ); Thu, 14 Jan 2021 05:39:19 -0500 Received: from mail-pf1-x42a.google.com (mail-pf1-x42a.google.com [IPv6:2607:f8b0:4864:20::42a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DA4D8C061757 for ; Thu, 14 Jan 2021 02:38:34 -0800 (PST) Received: by mail-pf1-x42a.google.com with SMTP id c12so3088544pfo.10 for ; Thu, 14 Jan 2021 02:38:34 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance-com.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=en8qVXfeyVDqIIP8px6ejCNcDJPI30a78TjFLPR7Emo=; b=Bb7SJUlOhKJC1ZzQyZRdMOsjlGvbnabYiGk73Uj/BFVF0fB4N9cHrQZRz2Ef0yCHtz E0ImuUx5/qPYjt+BO6+mt+i77HasP85vbfStHl0AMkjYZqvfQSCxTA3TCeXYPLtQ4PdS wXUz0Vic6sDxivwltEBJrz0GNebiJ66Ifr5RSYWWTDZRSXY1mLyQS2MVg9LAIwfSmSIB ybUqD2JIN8GSVmVAYNSBQysheqB+R0Jvdgx6W74b6s7lDL0K76LNty3kEJEGvFMEPns6 PWIZ0FhmKAbsQgfRtHki3p7AhVx6ukdkvuhjAEY2WIARmoHDLMLmhZAA8T6SGZVfeqmz JyqQ== 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:in-reply-to :references:mime-version:content-transfer-encoding; bh=en8qVXfeyVDqIIP8px6ejCNcDJPI30a78TjFLPR7Emo=; b=fuP5kPqRyh00l70v6v7G2REaBPehNC9l541nNC/P70+RyEhCAwABnRjllwDyAdREk0 XkosNGCJyvmKvobYsGTod97taYJEgef3Xbdu8YB3Cw79xH8V2gX+o0Ve0a77Zd19xiOY uJpg/T3NGzaRkLzlRysybeCgfbLpYNtdCTT1kSr3S2/xxhM+xxar9XfMcfF3YyBrG7ci 6YfzBzxWLOd0n5rgYM+Yobzvzsoxtpfk1L8teCZNQV2ms+mORAo226UyiO/GqP2C+iYj 44i8cIW3H1GqN9zxa2yIAd3knoZYIGJtRPHQMV5Ci/56mMV73zt9XYCpFi0gKpRkfKFK meEg== X-Gm-Message-State: AOAM533N2PnHdmkGK3m6zWNbB2bh5x87aG711KBKDJlj/5sTD93Kpr6x JDomfPEU/5WHcrzi9bRB3XkG1g== X-Google-Smtp-Source: ABdhPJzYhufPXUdWQ/iuHCLrwoMhWfXjHdW3SAj4YRCzZdLGSVm2HIBKmnA9RKGGOzKXrViUuR2j/w== X-Received: by 2002:a63:7904:: with SMTP id u4mr6863861pgc.41.1610620714482; Thu, 14 Jan 2021 02:38:34 -0800 (PST) Received: from localhost.localdomain ([139.177.225.247]) by smtp.gmail.com with ESMTPSA id l12sm4970112pjq.7.2021.01.14.02.38.30 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Thu, 14 Jan 2021 02:38:33 -0800 (PST) From: Muchun Song To: mike.kravetz@oracle.com, akpm@linux-foundation.org Cc: n-horiguchi@ah.jp.nec.com, ak@linux.intel.com, mhocko@suse.cz, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Muchun Song , Michal Hocko , Oscar Salvador , stable@vger.kernel.org Subject: [PATCH v5 2/5] mm: hugetlbfs: fix cannot migrate the fallocated HugeTLB page Date: Thu, 14 Jan 2021 18:35:12 +0800 Message-Id: <20210114103515.12955-3-songmuchun@bytedance.com> X-Mailer: git-send-email 2.21.0 (Apple Git-122) In-Reply-To: <20210114103515.12955-1-songmuchun@bytedance.com> References: <20210114103515.12955-1-songmuchun@bytedance.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org If a new hugetlb page is allocated during fallocate it will not be marked as active (set_page_huge_active) which will result in a later isolate_huge_page failure when the page migration code would like to move that page. Such a failure would be unexpected and wrong. Only export set_page_huge_active, just leave clear_page_huge_active as static. Because there are no external users. Fixes: 70c3547e36f5 (hugetlbfs: add hugetlbfs_fallocate()) Signed-off-by: Muchun Song Acked-by: Michal Hocko Reviewed-by: Mike Kravetz Reviewed-by: Oscar Salvador Cc: stable@vger.kernel.org --- fs/hugetlbfs/inode.c | 3 ++- include/linux/hugetlb.h | 2 ++ mm/hugetlb.c | 2 +- 3 files changed, 5 insertions(+), 2 deletions(-) diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c index b5c109703daa..21c20fd5f9ee 100644 --- a/fs/hugetlbfs/inode.c +++ b/fs/hugetlbfs/inode.c @@ -735,9 +735,10 @@ static long hugetlbfs_fallocate(struct file *file, int mode, loff_t offset, mutex_unlock(&hugetlb_fault_mutex_table[hash]); + set_page_huge_active(page); /* * unlock_page because locked by add_to_page_cache() - * page_put due to reference from alloc_huge_page() + * put_page() due to reference from alloc_huge_page() */ unlock_page(page); put_page(page); diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h index ebca2ef02212..b5807f23caf8 100644 --- a/include/linux/hugetlb.h +++ b/include/linux/hugetlb.h @@ -770,6 +770,8 @@ static inline void huge_ptep_modify_prot_commit(struct vm_area_struct *vma, } #endif +void set_page_huge_active(struct page *page); + #else /* CONFIG_HUGETLB_PAGE */ struct hstate {}; diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 1f3bf1710b66..4741d60f8955 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -1348,7 +1348,7 @@ bool page_huge_active(struct page *page) } /* never called for tail page */ -static void set_page_huge_active(struct page *page) +void set_page_huge_active(struct page *page) { VM_BUG_ON_PAGE(!PageHeadHuge(page), page); SetPagePrivate(&page[1]); From patchwork Thu Jan 14 10:35:13 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Muchun Song X-Patchwork-Id: 364664 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=-16.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, 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 5629DC4332E for ; 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Thu, 14 Jan 2021 02:38:38 -0800 (PST) Received: from localhost.localdomain ([139.177.225.247]) by smtp.gmail.com with ESMTPSA id l12sm4970112pjq.7.2021.01.14.02.38.34 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Thu, 14 Jan 2021 02:38:38 -0800 (PST) From: Muchun Song To: mike.kravetz@oracle.com, akpm@linux-foundation.org Cc: n-horiguchi@ah.jp.nec.com, ak@linux.intel.com, mhocko@suse.cz, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Muchun Song , stable@vger.kernel.org Subject: [PATCH v5 3/5] mm: hugetlb: fix a race between freeing and dissolving the page Date: Thu, 14 Jan 2021 18:35:13 +0800 Message-Id: <20210114103515.12955-4-songmuchun@bytedance.com> X-Mailer: git-send-email 2.21.0 (Apple Git-122) In-Reply-To: <20210114103515.12955-1-songmuchun@bytedance.com> References: <20210114103515.12955-1-songmuchun@bytedance.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org There is a race condition between __free_huge_page() and dissolve_free_huge_page(). CPU0: CPU1: // page_count(page) == 1 put_page(page) __free_huge_page(page) dissolve_free_huge_page(page) spin_lock(&hugetlb_lock) // PageHuge(page) && !page_count(page) update_and_free_page(page) // page is freed to the buddy spin_unlock(&hugetlb_lock) spin_lock(&hugetlb_lock) clear_page_huge_active(page) enqueue_huge_page(page) // It is wrong, the page is already freed spin_unlock(&hugetlb_lock) The race windows is between put_page() and dissolve_free_huge_page(). We should make sure that the page is already on the free list when it is dissolved. Fixes: c8721bbbdd36 ("mm: memory-hotplug: enable memory hotplug to handle hugepage") Signed-off-by: Muchun Song Reviewed-by: Mike Kravetz Cc: stable@vger.kernel.org --- mm/hugetlb.c | 41 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 41 insertions(+) diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 4741d60f8955..1b789d1fd06b 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -79,6 +79,21 @@ DEFINE_SPINLOCK(hugetlb_lock); static int num_fault_mutexes; struct mutex *hugetlb_fault_mutex_table ____cacheline_aligned_in_smp; +static inline bool PageHugeFreed(struct page *head) +{ + return page_private(head + 4) == -1UL; +} + +static inline void SetPageHugeFreed(struct page *head) +{ + set_page_private(head + 4, -1UL); +} + +static inline void ClearPageHugeFreed(struct page *head) +{ + set_page_private(head + 4, 0); +} + /* Forward declaration */ static int hugetlb_acct_memory(struct hstate *h, long delta); @@ -1028,6 +1043,7 @@ static void enqueue_huge_page(struct hstate *h, struct page *page) list_move(&page->lru, &h->hugepage_freelists[nid]); h->free_huge_pages++; h->free_huge_pages_node[nid]++; + SetPageHugeFreed(page); } static struct page *dequeue_huge_page_node_exact(struct hstate *h, int nid) @@ -1044,6 +1060,7 @@ static struct page *dequeue_huge_page_node_exact(struct hstate *h, int nid) list_move(&page->lru, &h->hugepage_activelist); set_page_refcounted(page); + ClearPageHugeFreed(page); h->free_huge_pages--; h->free_huge_pages_node[nid]--; return page; @@ -1504,6 +1521,7 @@ static void prep_new_huge_page(struct hstate *h, struct page *page, int nid) spin_lock(&hugetlb_lock); h->nr_huge_pages++; h->nr_huge_pages_node[nid]++; + ClearPageHugeFreed(page); spin_unlock(&hugetlb_lock); } @@ -1754,6 +1772,7 @@ int dissolve_free_huge_page(struct page *page) { int rc = -EBUSY; +retry: /* Not to disrupt normal path by vainly holding hugetlb_lock */ if (!PageHuge(page)) return 0; @@ -1770,6 +1789,28 @@ int dissolve_free_huge_page(struct page *page) int nid = page_to_nid(head); if (h->free_huge_pages - h->resv_huge_pages == 0) goto out; + + /* + * We should make sure that the page is already on the free list + * when it is dissolved. + */ + if (unlikely(!PageHugeFreed(head))) { + spin_unlock(&hugetlb_lock); + + /* + * Theoretically, we should return -EBUSY when we + * encounter this race. In fact, we have a chance + * to successfully dissolve the page if we do a + * retry. Because the race window is quite small. + * If we seize this opportunity, it is an optimization + * for increasing the success rate of dissolving page. + */ + while (PageHeadHuge(head) && !PageHugeFreed(head)) + cond_resched(); + + goto retry; + } + /* * Move PageHWPoison flag from head page to the raw error page, * which makes any subpages rather than the error page reusable. From patchwork Thu Jan 14 10:35:14 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Muchun Song X-Patchwork-Id: 364663 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=-16.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable 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 A6DD8C433E0 for ; Thu, 14 Jan 2021 10:40:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5E73E23A50 for ; Thu, 14 Jan 2021 10:40:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728977AbhANKj6 (ORCPT ); Thu, 14 Jan 2021 05:39:58 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43550 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728847AbhANKju (ORCPT ); Thu, 14 Jan 2021 05:39:50 -0500 Received: from mail-pf1-x434.google.com (mail-pf1-x434.google.com [IPv6:2607:f8b0:4864:20::434]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9A4BDC0613D6 for ; Thu, 14 Jan 2021 02:38:43 -0800 (PST) Received: by mail-pf1-x434.google.com with SMTP id q20so3097795pfu.8 for ; Thu, 14 Jan 2021 02:38:43 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance-com.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=0cYwNXoL62ufowFhR51LMghCmA8txi2r5XxTjm0v6q4=; b=WAckzXA3NYKMKzPO7d3fxmhmFa8XPvuFtpLdTcYJt0gP2l6AyanNdZetxWYn6M6gh8 EKuAhkJ6BYRwelX6ez+H0e0UwT09Rsu1xybpU2VtIhSNwzQ4q564A5sHSawFcgoY9os5 aRZU6FJl2PWqX/JDf7WGYUMv6bB57KPfWNlRn5mAAwJ4TbBZjzwFRwyh+fKQFrlN9HMc AvQvmaLzm4gORcjnaSbXJ8kNWYLsxPdqFhs/H/MNrGp7PBz5QrXC8MhkbZ1saUcpzFhT 28eZaFI5C/HuYjZZMBu5/YFIV5rta7rOuHR6JMNWnCGh2KIUhh/mpFuG8LKNOD1QzfZ+ KVZA== 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:in-reply-to :references:mime-version:content-transfer-encoding; bh=0cYwNXoL62ufowFhR51LMghCmA8txi2r5XxTjm0v6q4=; b=IhkqVQruaFUoJmLMLCDybvjJkOzmGRsVYwIJr8zE9bp17Y8W2uFlFWrJgxLFXrWquU XIPKLihj1bAkOvT54Zu4K3SKufssfqp43qKTMHbQ8qUh/kTod4LbqdALPDVKNnwR/ip9 QbHWILITW5HFNNfdsLKaSMtCnXOdewyfbkvjyGGF+KwU1RjiivRQGqpdthEO7SXb/x3g zWfEPxOx0GoA5mNI3PnS9UZppUEdNPMX4WkugXo0wlL6uCo2wp4GXmUVWwq8rxVRTPUd vjJq9ppa1b+yU6Wan968WaE0i4cDgrL8O75oJS/rMErVgFIH+PfUMRpEPhjUmygj5EK3 x00A== X-Gm-Message-State: AOAM530R+5ouFdBSlnx0hAvqeMSM5ZXdttI96cmNk8HOBYo0vfm2zD0T MNWG39IrGZkeV+WYssB3o3OsVA== X-Google-Smtp-Source: ABdhPJxXNYBJ+M1mhSEdHS3f5xG3SEV5dk5DG3dTkVKcMRSTqqZO27UWtQjHKdl0bxjQxbvpmqv9PA== X-Received: by 2002:a63:1c09:: with SMTP id c9mr6887350pgc.185.1610620723225; Thu, 14 Jan 2021 02:38:43 -0800 (PST) Received: from localhost.localdomain ([139.177.225.247]) by smtp.gmail.com with ESMTPSA id l12sm4970112pjq.7.2021.01.14.02.38.39 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Thu, 14 Jan 2021 02:38:42 -0800 (PST) From: Muchun Song To: mike.kravetz@oracle.com, akpm@linux-foundation.org Cc: n-horiguchi@ah.jp.nec.com, ak@linux.intel.com, mhocko@suse.cz, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Muchun Song , Michal Hocko , stable@vger.kernel.org Subject: [PATCH v5 4/5] mm: hugetlb: fix a race between isolating and freeing page Date: Thu, 14 Jan 2021 18:35:14 +0800 Message-Id: <20210114103515.12955-5-songmuchun@bytedance.com> X-Mailer: git-send-email 2.21.0 (Apple Git-122) In-Reply-To: <20210114103515.12955-1-songmuchun@bytedance.com> References: <20210114103515.12955-1-songmuchun@bytedance.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org There is a race between isolate_huge_page() and __free_huge_page(). CPU0: CPU1: if (PageHuge(page)) put_page(page) __free_huge_page(page) spin_lock(&hugetlb_lock) update_and_free_page(page) set_compound_page_dtor(page, NULL_COMPOUND_DTOR) spin_unlock(&hugetlb_lock) isolate_huge_page(page) // trigger BUG_ON VM_BUG_ON_PAGE(!PageHead(page), page) spin_lock(&hugetlb_lock) page_huge_active(page) // trigger BUG_ON VM_BUG_ON_PAGE(!PageHuge(page), page) spin_unlock(&hugetlb_lock) When we isolate a HugeTLB page on CPU0. Meanwhile, we free it to the buddy allocator on CPU1. Then, we can trigger a BUG_ON on CPU0. Because it is already freed to the buddy allocator. Fixes: c8721bbbdd36 ("mm: memory-hotplug: enable memory hotplug to handle hugepage") Signed-off-by: Muchun Song Reviewed-by: Mike Kravetz Acked-by: Michal Hocko Cc: stable@vger.kernel.org --- mm/hugetlb.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 1b789d1fd06b..43b7a044f248 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -5574,9 +5574,9 @@ bool isolate_huge_page(struct page *page, struct list_head *list) { bool ret = true; - VM_BUG_ON_PAGE(!PageHead(page), page); spin_lock(&hugetlb_lock); - if (!page_huge_active(page) || !get_page_unless_zero(page)) { + if (!PageHeadHuge(page) || !page_huge_active(page) || + !get_page_unless_zero(page)) { ret = false; goto unlock; } From patchwork Thu Jan 14 10:35:15 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Muchun Song X-Patchwork-Id: 363505 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=-16.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable 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 85CF9C433DB for ; Thu, 14 Jan 2021 10:40:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 32C4F23A3B for ; Thu, 14 Jan 2021 10:40:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727292AbhANKkL (ORCPT ); Thu, 14 Jan 2021 05:40:11 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43596 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728989AbhANKkC (ORCPT ); Thu, 14 Jan 2021 05:40:02 -0500 Received: from mail-pj1-x102a.google.com (mail-pj1-x102a.google.com [IPv6:2607:f8b0:4864:20::102a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 801B8C061573 for ; Thu, 14 Jan 2021 02:38:48 -0800 (PST) Received: by mail-pj1-x102a.google.com with SMTP id j13so2967579pjz.3 for ; Thu, 14 Jan 2021 02:38:48 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance-com.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=4WYNxXgkqgGvh7TvTAzouOPetrx1LoimOg0RJns9SBk=; b=ZBD5gnOQj7KeBVofomR1qkSaECGUOhQdp1osQN6ZOThgdZogDsFTBtZ/UPy/Fvhg/Y e4y1J16wFNiDZD0xLv/xzUuEu/Uy2Qf2zxHfYcnGBANteZOYViau06OYWLZ8Y7nvNS2+ A+oSHmPV/G0UHoMjsWYib5rSXrmvJ2PJXUdgpMZKuCiMg/Ypi6YUEbmLiHSdolK65Wix MllM9G07BsivId819gXQKwHrDg3oT7skErXB7KzDU2X8hlExHeC4FMyn0d9oOO/cVnQm tgw5v56H0Tq8HN9pE1YFYF8daohNuRNHVQbP+hIiX6umTwGYRAurPbU4wFA8nWXeg921 aGDQ== 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:in-reply-to :references:mime-version:content-transfer-encoding; bh=4WYNxXgkqgGvh7TvTAzouOPetrx1LoimOg0RJns9SBk=; b=s151VFuQCUUZyG7aOxSOo1sq7N4nT9NnTZ+6z6Cavf+A1ZuMQeM04KRFn0jFoGoEcY WPH9GyT4buE1/PELZibVxbxtyiFq2HFaCdOmSN51PORS3V0rJZwmBTJa0X3Zdg++t8Gy f9PKonGNrpkFhvizc78ersNewap1A9MHLQVBkwSR5ydpwkyfUmVqDqMT0FnL8Zs5bALc iqBHyPB7Z7h9O+BBk2jb2i/iHVB5PcF5aPfWIUG47aYefZJTCBZmnnb11wNPsA/JSZp2 t0DDuENOD0KEyg3RmCCJn6crTyOet9k/tbP1F7V39Z4CX1bpTjhJwowWG4vXIlDr43IZ Wlkw== X-Gm-Message-State: AOAM533eYInuVaKVMftQ/ELHXa2xZvUv2REF/kXkILzkLzh5Bxbbl7De Z80WDtiwGYLNgZx6hHp4eemX6g== X-Google-Smtp-Source: ABdhPJxyztuJ0uI2Xtsn9clsCA2I9Y1fjJWQwyTIuJw00n1p1nR234xsKV8aRN3YjRK92vlFEBAmxw== X-Received: by 2002:a17:902:8a88:b029:dc:f3:6db2 with SMTP id p8-20020a1709028a88b02900dc00f36db2mr6991795plo.2.1610620728126; Thu, 14 Jan 2021 02:38:48 -0800 (PST) Received: from localhost.localdomain ([139.177.225.247]) by smtp.gmail.com with ESMTPSA id l12sm4970112pjq.7.2021.01.14.02.38.43 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Thu, 14 Jan 2021 02:38:47 -0800 (PST) From: Muchun Song To: mike.kravetz@oracle.com, akpm@linux-foundation.org Cc: n-horiguchi@ah.jp.nec.com, ak@linux.intel.com, mhocko@suse.cz, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Muchun Song , Michal Hocko , stable@vger.kernel.org Subject: [PATCH v5 5/5] mm: hugetlb: remove VM_BUG_ON_PAGE from page_huge_active Date: Thu, 14 Jan 2021 18:35:15 +0800 Message-Id: <20210114103515.12955-6-songmuchun@bytedance.com> X-Mailer: git-send-email 2.21.0 (Apple Git-122) In-Reply-To: <20210114103515.12955-1-songmuchun@bytedance.com> References: <20210114103515.12955-1-songmuchun@bytedance.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org The page_huge_active() can be called from scan_movable_pages() which do not hold a reference count to the HugeTLB page. So when we call page_huge_active() from scan_movable_pages(), the HugeTLB page can be freed parallel. Then we will trigger a BUG_ON which is in the page_huge_active() when CONFIG_DEBUG_VM is enabled. Just remove the VM_BUG_ON_PAGE. Fixes: 7e1f049efb86 ("mm: hugetlb: cleanup using paeg_huge_active()") Signed-off-by: Muchun Song Reviewed-by: Mike Kravetz Acked-by: Michal Hocko Cc: stable@vger.kernel.org --- mm/hugetlb.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 43b7a044f248..6c5dfef682cc 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -1360,8 +1360,7 @@ struct hstate *size_to_hstate(unsigned long size) */ bool page_huge_active(struct page *page) { - VM_BUG_ON_PAGE(!PageHuge(page), page); - return PageHead(page) && PagePrivate(&page[1]); + return PageHeadHuge(page) && PagePrivate(&page[1]); } /* never called for tail page */