From patchwork Wed Apr 22 09:57:23 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: "gregkh@linuxfoundation.org" X-Patchwork-Id: 227121 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,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 18F69C5518A for ; Wed, 22 Apr 2020 10:48:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E759F2076E for ; Wed, 22 Apr 2020 10:48:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587552486; bh=NwE/eePGRE2epUa7HeUfEFC+VuWkfx6PsFIOES8/qPE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=i7UNRyA7DkRYgmUSPH8e414351ImhcHylVtpm3L+gR+qYlaRhoIavvql1y27P0xSE 90pl34e0CbyO7h7Vro4nekxnyQCUKKKNlEJ/SG7QlJzD1xXbV28i6Znqr4HOlw1/NK WB63FMpqZ/weLwxNZ0sPqituAQkIZ4Tkf+rMPYs4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729230AbgDVKsF (ORCPT ); Wed, 22 Apr 2020 06:48:05 -0400 Received: from mail.kernel.org ([198.145.29.99]:49842 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729599AbgDVKOz (ORCPT ); Wed, 22 Apr 2020 06:14:55 -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 3299920575; Wed, 22 Apr 2020 10:14:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587550494; bh=NwE/eePGRE2epUa7HeUfEFC+VuWkfx6PsFIOES8/qPE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Ux4d0NbOEjaZRpTLqhcjmLTf54/KYxIdtzNkaqDjDYrCLXcxBP/Fh+2HT6oe/jGL3 VWrB6cWNG+KnbjHVBbW7yhSmKKP1HXEwJ+RhJbtRu/5mAZ57hKWuWkYGzMlMTucIXX jbVMfecgewk7Y+pQUpFH1UF1WADy/y+BijgpSmio= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Steven Price , Andrew Morton , =?utf-8?b?SsOpcsO0bWUgR2xp?= =?utf-8?q?sse?= , Arnd Bergmann , Dan Williams , John Hubbard , Linus Torvalds , Sasha Levin Subject: [PATCH 4.19 39/64] include/linux/swapops.h: correct guards for non_swap_entry() Date: Wed, 22 Apr 2020 11:57:23 +0200 Message-Id: <20200422095020.026555152@linuxfoundation.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200422095008.799686511@linuxfoundation.org> References: <20200422095008.799686511@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Steven Price [ Upstream commit 3f3673d7d324d872d9d8ddb73b3e5e47fbf12e0d ] If CONFIG_DEVICE_PRIVATE is defined, but neither CONFIG_MEMORY_FAILURE nor CONFIG_MIGRATION, then non_swap_entry() will return 0, meaning that the condition (non_swap_entry(entry) && is_device_private_entry(entry)) in zap_pte_range() will never be true even if the entry is a device private one. Equally any other code depending on non_swap_entry() will not function as expected. I originally spotted this just by looking at the code, I haven't actually observed any problems. Looking a bit more closely it appears that actually this situation (currently at least) cannot occur: DEVICE_PRIVATE depends on ZONE_DEVICE ZONE_DEVICE depends on MEMORY_HOTREMOVE MEMORY_HOTREMOVE depends on MIGRATION Fixes: 5042db43cc26 ("mm/ZONE_DEVICE: new type of ZONE_DEVICE for unaddressable memory") Signed-off-by: Steven Price Signed-off-by: Andrew Morton Cc: Jérôme Glisse Cc: Arnd Bergmann Cc: Dan Williams Cc: John Hubbard Link: http://lkml.kernel.org/r/20200305130550.22693-1-steven.price@arm.com Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin --- include/linux/swapops.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/include/linux/swapops.h b/include/linux/swapops.h index 22af9d8a84ae2..28d572b7ea73e 100644 --- a/include/linux/swapops.h +++ b/include/linux/swapops.h @@ -368,7 +368,8 @@ static inline void num_poisoned_pages_inc(void) } #endif -#if defined(CONFIG_MEMORY_FAILURE) || defined(CONFIG_MIGRATION) +#if defined(CONFIG_MEMORY_FAILURE) || defined(CONFIG_MIGRATION) || \ + defined(CONFIG_DEVICE_PRIVATE) static inline int non_swap_entry(swp_entry_t entry) { return swp_type(entry) >= MAX_SWAPFILES;