From patchwork Tue Apr 7 03:08:43 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Andrew Morton X-Patchwork-Id: 11477347 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 340D292A for ; Tue, 7 Apr 2020 03:08:47 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 029B720936 for ; Tue, 7 Apr 2020 03:08:47 +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 029B720936 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) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id A2FA18E0001; Mon, 6 Apr 2020 23:08:45 -0400 (EDT) X-Original-To: int-list-linux-mm@kvack.org 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-Original-To: linux-mm@kvack.org 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-Spam-Summary: 2,0,0,92d055cc64db3fca,d41d8cd98f00b204,akpm@linux-foundation.org,,RULES_HIT:41:152:355:379:800:960:967:968:973:988:989:1260:1263:1277:1311:1313:1314:1345:1359:1381:1431:1437:1513:1515:1516:1518:1521:1534:1541:1593:1594:1711:1730:1747:1777:1792:2393:2525:2559:2563:2682:2685:2693:2730:2859:2902:2933:2937:2939:2942:2945:2947:2951:2954:3022:3138:3139:3140:3141:3142:3352:3865:3866:3870:3871:3872:3874:3934:3936:3938:3941:3944:3947:3950:3953:3956:3959:4321:5007:6261:6653:7576:7903:8599:8784:9025:9545:10004:10400:10913:11026:11473:11658:11914:12043:12048:12296:12297:12438:12517:12519:12555:12679:12783:12986:13069:13311:13357:13846:14181:14721:14849:21063:21080:21324:21451:21627:21939:21990:30012:30054:30064,0,RBL:198.145.29.99:@linux-foundation.org:.lbl8.mailshell.net-64.100.201.201 62.2.0.100,CacheIP:none,Bayesian:0.5,0.5,0.5,Netcheck:none,DomainCache:0,MSF:not bulk,SPF:fp,MSBL:0,DNSBL:neutral,Custom_rules:0:0:0,LFtime:2,LUA_SUMMARY:none 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 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: From: 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 unaddressable memory") Signed-off-by: Steven Price Cc: Jérôme 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 -#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;