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=-19.3 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, 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,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 4153AC433E6 for ; Mon, 8 Feb 2021 15:25:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E6E2464DDB for ; Mon, 8 Feb 2021 15:25:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233637AbhBHPZB (ORCPT ); Mon, 8 Feb 2021 10:25:01 -0500 Received: from mail.kernel.org ([198.145.29.99]:52602 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232930AbhBHPEe (ORCPT ); Mon, 8 Feb 2021 10:04:34 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 8E56764EC3; Mon, 8 Feb 2021 15:03:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1612796589; bh=PIvAXajXlDm6uxsTVk8m4cPi9wnjRkFg096EugYd7Yw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=TCG2uRhHYnr8XNUFno2lnN0/HUx8RfrwE/XUy+s42EC/gbSQVIyO8FvSNyGB170Tr 0xvAaKbTBxkDuUwjzlNBMvd8K/lu7XScvNsR/QGEvYi98MnfoXoq9+ZuNuojwZr8JA QgF/aTYtiU7nqowPDuKCNjBPY0c1ArZl8NWcMH5c= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Muchun Song , Mike Kravetz , Michal Hocko , Oscar Salvador , David Hildenbrand , Yang Shi , Andrew Morton , Linus Torvalds Subject: [PATCH 4.4 33/38] mm: hugetlb: remove VM_BUG_ON_PAGE from page_huge_active Date: Mon, 8 Feb 2021 16:00:55 +0100 Message-Id: <20210208145806.558714124@linuxfoundation.org> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210208145805.279815326@linuxfoundation.org> References: <20210208145805.279815326@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Muchun Song commit ecbf4724e6061b4b01be20f6d797d64d462b2bc8 upstream. 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. Link: https://lkml.kernel.org/r/20210115124942.46403-6-songmuchun@bytedance.com Fixes: 7e1f049efb86 ("mm: hugetlb: cleanup using paeg_huge_active()") Signed-off-by: Muchun Song Reviewed-by: Mike Kravetz Acked-by: Michal Hocko Reviewed-by: Oscar Salvador Cc: David Hildenbrand Cc: Yang Shi Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- mm/hugetlb.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -1184,8 +1184,7 @@ struct hstate *size_to_hstate(unsigned l */ 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 */