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=-3.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 400C9C2BA1A for ; Tue, 7 Apr 2020 03:08:46 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 03AF220936 for ; Tue, 7 Apr 2020 03:08:46 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="0KSYZklQ" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 03AF220936 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id AA1A68E005E; Mon, 6 Apr 2020 23:08:45 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id A2FA18E0001; Mon, 6 Apr 2020 23:08:45 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 8CBC48E005E; Mon, 6 Apr 2020 23:08:45 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0027.hostedemail.com [216.40.44.27]) by kanga.kvack.org (Postfix) with ESMTP id 729568E0001 for ; Mon, 6 Apr 2020 23:08:45 -0400 (EDT) Received: from smtpin15.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 2F610A8C8 for ; Tue, 7 Apr 2020 03:08:45 +0000 (UTC) X-FDA: 76679576610.15.voice84_869898df54333 X-HE-Tag: voice84_869898df54333 X-Filterd-Recvd-Size: 3372 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf13.hostedemail.com (Postfix) with ESMTP for ; Tue, 7 Apr 2020 03:08:44 +0000 (UTC) Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (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 C863420801; Tue, 7 Apr 2020 03:08:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1586228924; bh=YoGqb481WrerhnxumHuCzvtjzYPT/HUjl2USFxHnR+o=; h=Date:From:To:Subject:In-Reply-To:From; b=0KSYZklQ53I7v+pqZ8THQJrBjf7p2BE3h4yg9wZyNPq6wcKU32gBXLRL6ROWCZBsM 8dGIzz+T0moZHHIJoiztSdQi07p0/54seqx2yXYXR7sgsap0UR9GqCjHaus0mTlt// wjEU338Nvi80tu6ozB/76IV0Iyw8K1Tzp1TFI3mM= Date: Mon, 06 Apr 2020 20:08:43 -0700 From: Andrew Morton To: akpm@linux-foundation.org, arnd@arndb.de, dan.j.williams@intel.com, jglisse@redhat.com, jhubbard@nvidia.com, linux-mm@kvack.org, mm-commits@vger.kernel.org, steven.price@arm.com, torvalds@linux-foundation.org Subject: [patch 089/166] include/linux/swapops.h: correct guards for non_swap_entry() Message-ID: <20200407030843.XB8zAqurU%akpm@linux-foundation.org> In-Reply-To: <20200406200254.a69ebd9e08c4074e41ddebaf@linux-foundation.org> User-Agent: s-nail v14.8.16 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: =46rom: Steven Price Subject: include/linux/swapops.h: correct guards for non_swap_entry() 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 Link: http://lkml.kernel.org/r/20200305130550.22693-1-steven.price@arm.com Fixes: 5042db43cc26 ("mm/ZONE_DEVICE: new type of ZONE_DEVICE for unaddress= able memory") Signed-off-by: Steven Price Cc: J=C3=A9r=C3=B4me Glisse Cc: Arnd Bergmann Cc: Dan Williams Cc: John Hubbard Signed-off-by: Andrew Morton --- include/linux/swapops.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/include/linux/swapops.h~mm-correct-guards-for-non_swap_entry +++ a/include/linux/swapops.h @@ -350,7 +350,8 @@ static inline void num_poisoned_pages_in } #endif =20 -#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) >=3D MAX_SWAPFILES; _