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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 E6FCFC2BA19 for ; Wed, 15 Apr 2020 12:09:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BCEFA206F9 for ; Wed, 15 Apr 2020 12:09:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1586952541; bh=HWzTKrebOBV1otFjWMBXGbtXfVe7Pq8ScR7pIMJg+JM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=TZbLhYnKY7/y5ftsz6qiF5hbaJdjnvJir5SoyTwewsxbNiAieP47ZE50Ccb+shm6G NWMoSnB2TQ2SDW/PrB+It8TCuUndUL4GFIvGMU64Ab9VCN7Ld9qE/ZdrE7i0aXHb3m hhI/i/XvgZ543ty72LxWiMHcMTG3VJMuZlDDmP24= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S368179AbgDOMI7 (ORCPT ); Wed, 15 Apr 2020 08:08:59 -0400 Received: from mail.kernel.org ([198.145.29.99]:42906 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2406273AbgDOLrf (ORCPT ); Wed, 15 Apr 2020 07:47:35 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id EAF2521655; Wed, 15 Apr 2020 11:47:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1586951250; bh=HWzTKrebOBV1otFjWMBXGbtXfVe7Pq8ScR7pIMJg+JM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=onGtAGAxEgfGMJyJGTER/5/dtK1CkxX9Eq++JKOrsaPatfANRjWDzb/l3XwPLabSp hYRztfAPxRzlkzq57ia63pq6Z0wrsr4JriGq0MWpIoRjxgyp3e2AkHqYQJFOAq62o/ i81UJ4ABaJVvRQ+POrx/pBHy36sUT588TYc4a/60= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Steven Price , Andrew Morton , =?UTF-8?q?J=C3=A9r=C3=B4me=20Glisse?= , Arnd Bergmann , Dan Williams , John Hubbard , Linus Torvalds , Sasha Levin Subject: [PATCH AUTOSEL 4.14 16/30] include/linux/swapops.h: correct guards for non_swap_entry() Date: Wed, 15 Apr 2020 07:46:57 -0400 Message-Id: <20200415114711.15381-16-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200415114711.15381-1-sashal@kernel.org> References: <20200415114711.15381-1-sashal@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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 1d3877c39a000..0b8c860967527 100644 --- a/include/linux/swapops.h +++ b/include/linux/swapops.h @@ -377,7 +377,8 @@ 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; -- 2.20.1