From patchwork Fri May 13 14:24:04 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 572912 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0C487C433EF for ; Fri, 13 May 2022 14:33:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1381094AbiEMOdc (ORCPT ); Fri, 13 May 2022 10:33:32 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59384 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1381101AbiEMOcG (ORCPT ); Fri, 13 May 2022 10:32:06 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B62B91B5F85; Fri, 13 May 2022 07:29:24 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 4761F61F99; Fri, 13 May 2022 14:29:24 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7FB8FC34100; Fri, 13 May 2022 14:29:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1652452163; bh=8Zwr3W7JIAHfeLtAAfAERk0dZRqAj/i3KN79SO7IoEg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=zuiayYk/gmgXHKh3MvRTWTL63h+2IpMF9HovkeP7LpANn/PNSE4Hm8Sy6UJezeDm/ 6MDNGLsf37cOa/hvu12IRuA6e2IGZFTyD4xOofK3T5DcLvuzFWLj9yH0aW0Z6bOHjg wy96H+CLA9ua4rVrvTpxvWZ3rF2F/G1tlWtyW2WA= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Muchun Song , Zi Yan , Axel Rasmussen , David Rientjes , Fam Zheng , "Kirill A. Shutemov" , Lars Persson , Mike Kravetz , Peter Xu , Xiongchun Duan , Andrew Morton , Linus Torvalds Subject: [PATCH 5.17 04/12] mm: fix missing cache flush for all tail pages of compound page Date: Fri, 13 May 2022 16:24:04 +0200 Message-Id: <20220513142228.781532891@linuxfoundation.org> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20220513142228.651822943@linuxfoundation.org> References: <20220513142228.651822943@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Muchun Song commit 2771739a7162782c0aa6424b2e3dd874e884a15d upstream. The D-cache maintenance inside move_to_new_page() only consider one page, there is still D-cache maintenance issue for tail pages of compound page (e.g. THP or HugeTLB). THP migration is only enabled on x86_64, ARM64 and powerpc, while powerpc and arm64 need to maintain the consistency between I-Cache and D-Cache, which depends on flush_dcache_page() to maintain the consistency between I-Cache and D-Cache. But there is no issues on arm64 and powerpc since they already considers the compound page cache flushing in their icache flush function. HugeTLB migration is enabled on arm, arm64, mips, parisc, powerpc, riscv, s390 and sh, while arm has handled the compound page cache flush in flush_dcache_page(), but most others do not. In theory, the issue exists on many architectures. Fix this by not using flush_dcache_folio() since it is not backportable. Link: https://lkml.kernel.org/r/20220210123058.79206-3-songmuchun@bytedance.com Fixes: 290408d4a250 ("hugetlb: hugepage migration core") Signed-off-by: Muchun Song Reviewed-by: Zi Yan Cc: Axel Rasmussen Cc: David Rientjes Cc: Fam Zheng Cc: Kirill A. Shutemov Cc: Lars Persson Cc: Mike Kravetz Cc: Peter Xu Cc: Xiongchun Duan Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- mm/migrate.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) --- a/mm/migrate.c +++ b/mm/migrate.c @@ -916,9 +916,12 @@ static int move_to_new_page(struct page if (!PageMappingFlags(page)) page->mapping = NULL; - if (likely(!is_zone_device_page(newpage))) - flush_dcache_page(newpage); + if (likely(!is_zone_device_page(newpage))) { + int i, nr = compound_nr(newpage); + for (i = 0; i < nr; i++) + flush_dcache_page(newpage + i); + } } out: return rc;