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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,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 1B51EC433FF for ; Mon, 5 Aug 2019 13:29:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E53FB20651 for ; Mon, 5 Aug 2019 13:29:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1565011755; bh=lZ4qH7eMqi86NFse/Iv5+y2ZDI6YfEIJiv4HFmce+Kc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=l8NeqRLl4pMXAMfoiuZEwjyA+QMC0OHWQrJLpBv7izEUPw1qDEmCzGUCkdVkb7TOG F4W2KxE9DASTx2Bq2NNU+XsJOPPBjbwCvbze8+WeYhIagNaSgcgwze9s8Ztn725Kmk ze6453kfdFoAQTdUDkeeoKkSBLB7jy3rGTuRNJ5E= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730283AbfHENWJ (ORCPT ); Mon, 5 Aug 2019 09:22:09 -0400 Received: from mail.kernel.org ([198.145.29.99]:58372 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730614AbfHENWE (ORCPT ); Mon, 5 Aug 2019 09:22:04 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 7E5EF20657; Mon, 5 Aug 2019 13:22:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1565011324; bh=lZ4qH7eMqi86NFse/Iv5+y2ZDI6YfEIJiv4HFmce+Kc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=zr+Vdc8Ak8nYZvYvQKpFZ3ncNBgsh8XXVuw0VgY+uSUXmvrmGMHJIrob5IOck33K5 S+66t2mVqaI9LB8JRtOPXS67ybllr1NT0sagnPiPEsfxlJoDuFOKRjAVe+L5qWGeem OtFMNANVx4E+Yp/PuSIFD/jmUqJVnSvrpQ6vQ+k0= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Henry Burns , Shakeel Butt , Vitaly Vul , Vitaly Wool , Jonathan Adams , Andrew Morton , Linus Torvalds , Sasha Levin Subject: [PATCH 5.2 050/131] mm/z3fold.c: reinitialize zhdr structs after migration Date: Mon, 5 Aug 2019 15:02:17 +0200 Message-Id: <20190805124954.784647814@linuxfoundation.org> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190805124951.453337465@linuxfoundation.org> References: <20190805124951.453337465@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org [ Upstream commit c92d2f38563db20c20c8db2f98fa1349290477d5 ] z3fold_page_migration() calls memcpy(new_zhdr, zhdr, PAGE_SIZE). However, zhdr contains fields that can't be directly coppied over (ex: list_head, a circular linked list). We only need to initialize the linked lists in new_zhdr, as z3fold_isolate_page() already ensures that these lists are empty Additionally it is possible that zhdr->work has been placed in a workqueue. In this case we shouldn't migrate the page, as zhdr->work references zhdr as opposed to new_zhdr. Link: http://lkml.kernel.org/r/20190716000520.230595-1-henryburns@google.com Fixes: 1f862989b04ade61d3 ("mm/z3fold.c: support page migration") Signed-off-by: Henry Burns Reviewed-by: Shakeel Butt Cc: Vitaly Vul Cc: Vitaly Wool Cc: Jonathan Adams Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin --- mm/z3fold.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/mm/z3fold.c b/mm/z3fold.c index 304f2883cdb93..3b27094dc42e1 100644 --- a/mm/z3fold.c +++ b/mm/z3fold.c @@ -1360,12 +1360,22 @@ static int z3fold_page_migrate(struct address_space *mapping, struct page *newpa unlock_page(page); return -EBUSY; } + if (work_pending(&zhdr->work)) { + z3fold_page_unlock(zhdr); + return -EAGAIN; + } new_zhdr = page_address(newpage); memcpy(new_zhdr, zhdr, PAGE_SIZE); newpage->private = page->private; page->private = 0; z3fold_page_unlock(zhdr); spin_lock_init(&new_zhdr->page_lock); + INIT_WORK(&new_zhdr->work, compact_page_work); + /* + * z3fold_page_isolate() ensures that new_zhdr->buddy is empty, + * so we only have to reinitialize it. + */ + INIT_LIST_HEAD(&new_zhdr->buddy); new_mapping = page_mapping(page); __ClearPageMovable(page); ClearPagePrivate(page); -- 2.20.1