From patchwork Fri Oct 25 07:26:09 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michal Hocko X-Patchwork-Id: 11211533 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 3D87213B1 for ; Fri, 25 Oct 2019 07:26:32 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 1409721D71 for ; Fri, 25 Oct 2019 07:26:32 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1409721D71 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 0DF6C6B0007; Fri, 25 Oct 2019 03:26:30 -0400 (EDT) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id 0693E6B0008; Fri, 25 Oct 2019 03:26:29 -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 E4B5F6B000A; Fri, 25 Oct 2019 03:26:29 -0400 (EDT) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0234.hostedemail.com [216.40.44.234]) by kanga.kvack.org (Postfix) with ESMTP id B5F146B0007 for ; Fri, 25 Oct 2019 03:26:29 -0400 (EDT) Received: from smtpin22.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with SMTP id 2F37418081D7E for ; Fri, 25 Oct 2019 07:26:29 +0000 (UTC) X-FDA: 76081474098.22.sand54_38954f9ccb61c X-Spam-Summary: 2,0,0,072fcf5caf262c9e,d41d8cd98f00b204,mstsxfx@gmail.com,:akpm@linux-foundation.org:mgorman@suse.de:longman@redhat.com:hannes@cmpxchg.org:guro@fb.com:vbabka@suse.cz:khlebnikov@yandex-team.ru:jannh@google.com:songliubraving@fb.com:gregkh@linuxfoundation.org:aquini@redhat.com::linux-kernel@vger.kernel.org:mhocko@suse.com:rientjes@google.com,RULES_HIT:41:355:379:541:800:960:966:973:988:989:1260:1311:1314:1345:1359:1431:1437:1515:1534:1541:1711:1730:1747:1777:1792:2196:2198:2199:2200:2393:2559:2562:3138:3139:3140:3141:3142:3352:3865:3867:3868:3870:3871:3872:3874:4321:4385:5007:6119:6261:6742:7576:7903:10004:11026:11473:11658:11914:12043:12296:12297:12517:12519:12555:12679:12895:13069:13221:13229:13311:13357:13894:14096:14181:14384:14394:14721:21067:21080:21444:21451:21627:30045:30054,0,RBL:209.85.128.68:@gmail.com:.lbl8.mailshell.net-62.18.0.100 66.100.201.100,CacheIP:none,Bayesian:0.5,0.5,0.5,Netcheck:none,DomainCache:0,MSF:not bulk,SPF:fp,MSBL:0,DNSBL:none,Cust om_rules X-HE-Tag: sand54_38954f9ccb61c X-Filterd-Recvd-Size: 4322 Received: from mail-wm1-f68.google.com (mail-wm1-f68.google.com [209.85.128.68]) by imf06.hostedemail.com (Postfix) with ESMTP for ; Fri, 25 Oct 2019 07:26:28 +0000 (UTC) Received: by mail-wm1-f68.google.com with SMTP id w9so876041wmm.5 for ; Fri, 25 Oct 2019 00:26:28 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=7W6FbSGYxJZDumQvlMVc5ne/04KsfBxl9tYdZk3V7Nw=; b=LVmXcKcvCmZxtje0m4nMDT8ZGX8Fqx+2oJXgzRWIhznMPJnau/55k7xgWPbIHqAUN4 TUWJd7TLwkkiniQmH7JPCbOKkvPTmA282c5wugsNL49ukDsIghqBXgxS/wN0jGtaOZTh mFtyjtKR2lPUb3LmGRUF03ZZvjHNw2USx/50P7JyfvzDxoqj7guon7KOPMP4YBmhkVm9 oOLfGZUJoW59jsWuheWC5v6TgijMzM6a8G11Ae4vBizlvvt8eggHiesGKW9HrkhigXhv k9CqK/9cKZby9eUrPAqtnAqDiGDeB44mGilmpTHUX8IqjKu4xh/hAoYbdoMl0m/vRmCv yYjA== X-Gm-Message-State: APjAAAUqwTKZqESXQUrZUeEzlQ8xDRpOCgWI7ZDkrnm7sxf0pA2asNyc o+wvwPkpcbs0iPFF0lB0uNQ= X-Google-Smtp-Source: APXvYqzlrOJMqwfNEekFRcsxH77kBxe3u0ROf9E7iGhcUHQQHJ0GCyAXn5S6NSbQ6DgpH57CuJdohQ== X-Received: by 2002:a05:600c:2293:: with SMTP id 19mr2010511wmf.9.1571988387773; Fri, 25 Oct 2019 00:26:27 -0700 (PDT) Received: from tiehlicka.microfocus.com (prg-ext-pat.suse.com. [213.151.95.130]) by smtp.gmail.com with ESMTPSA id x21sm1482446wmj.42.2019.10.25.00.26.26 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 25 Oct 2019 00:26:27 -0700 (PDT) From: Michal Hocko To: Andrew Morton , Mel Gorman , Waiman Long Cc: Johannes Weiner , Roman Gushchin , Vlastimil Babka , Konstantin Khlebnikov , Jann Horn , Song Liu , Greg Kroah-Hartman , Rafael Aquini , , LKML , Michal Hocko , David Rientjes Subject: [PATCH 1/2] mm, vmstat: hide /proc/pagetypeinfo from normal users Date: Fri, 25 Oct 2019 09:26:09 +0200 Message-Id: <20191025072610.18526-2-mhocko@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20191025072610.18526-1-mhocko@kernel.org> References: <20191025072610.18526-1-mhocko@kernel.org> 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: Michal Hocko /proc/pagetypeinfo is a debugging tool to examine internal page allocator state wrt to fragmentation. It is not very useful for any other use so normal users really do not need to read this file. Waiman Long has noticed that reading this file can have negative side effects because zone->lock is necessary for gathering data and that a) interferes with the page allocator and its users and b) can lead to hard lockups on large machines which have very long free_list. Reduce both issues by simply not exporting the file to regular users. Reported-by: Waiman Long Cc: stable Fixes: 467c996c1e19 ("Print out statistics in relation to fragmentation avoidance to /proc/pagetypeinfo") Acked-by: Mel Gorman Acked-by: Vlastimil Babka Acked-by: Waiman Long Acked-by: Rafael Aquini Acked-by: David Rientjes Signed-off-by: Michal Hocko --- mm/vmstat.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/vmstat.c b/mm/vmstat.c index 6afc892a148a..4e885ecd44d1 100644 --- a/mm/vmstat.c +++ b/mm/vmstat.c @@ -1972,7 +1972,7 @@ void __init init_mm_internals(void) #endif #ifdef CONFIG_PROC_FS proc_create_seq("buddyinfo", 0444, NULL, &fragmentation_op); - proc_create_seq("pagetypeinfo", 0444, NULL, &pagetypeinfo_op); + proc_create_seq("pagetypeinfo", 0400, NULL, &pagetypeinfo_op); proc_create_seq("vmstat", 0444, NULL, &vmstat_op); proc_create_seq("zoneinfo", 0444, NULL, &zoneinfo_op); #endif