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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id A9208C54EBE for ; Wed, 11 Jan 2023 10:54:49 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 0CB4F8E0002; Wed, 11 Jan 2023 05:54:49 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 07C3A8E0001; Wed, 11 Jan 2023 05:54:49 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id EACD78E0002; Wed, 11 Jan 2023 05:54:48 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id DAF458E0001 for ; Wed, 11 Jan 2023 05:54:48 -0500 (EST) Received: from smtpin24.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id 9E1AAAEA90 for ; Wed, 11 Jan 2023 10:54:48 +0000 (UTC) X-FDA: 80342210256.24.39594C1 Received: from wp530.webpack.hosteurope.de (wp530.webpack.hosteurope.de [80.237.130.52]) by imf27.hostedemail.com (Postfix) with ESMTP id A6A7D40003 for ; Wed, 11 Jan 2023 10:54:46 +0000 (UTC) Authentication-Results: imf27.hostedemail.com; dkim=none; dmarc=none; spf=pass (imf27.hostedemail.com: domain of regressions@leemhuis.info designates 80.237.130.52 as permitted sender) smtp.mailfrom=regressions@leemhuis.info ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1673434486; h=from:from:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=TSzOZRGqV3PU3fn73Csm6WikInBSzTCXrwZ1xs73Jj0=; b=yF8Gd6q16Z0av3R7BOt/RQN8zDsH5V51b/FNZ7nqMZDBChGwJP0/xoWAEL4JzPnp1b3UKv Z3Wu2Pg8yZjXcm+ivu15Sw6MSaCjGJjwSdh7an0m0oMbzk3scYYi3d7fj7EWzFzo0JIRXW 1hV8vHfTlQFyWeYEUiPB33DAExl8FRU= ARC-Authentication-Results: i=1; imf27.hostedemail.com; dkim=none; dmarc=none; spf=pass (imf27.hostedemail.com: domain of regressions@leemhuis.info designates 80.237.130.52 as permitted sender) smtp.mailfrom=regressions@leemhuis.info ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1673434486; a=rsa-sha256; cv=none; b=NPawtVtL1iRCbYyJ7nCxDpcCSiPg38EXJTr2vs2Es0UVWzaErBmLXv1gwcF7dNbqhxRMpp 3rGRDC8a0CD2oWbCJQd5oiqBr/ho2KPWNzuoy9Qgv5ZOG8o6/UcbBBA+ODxj5Nv2irsZjE ClHDAcr/81yec4n5i7Jw2VfCKVXp724= Received: from [2a02:8108:963f:de38:eca4:7d19:f9a2:22c5]; authenticated by wp530.webpack.hosteurope.de running ExIM with esmtpsa (TLS1.3:ECDHE_RSA_AES_128_GCM_SHA256:128) id 1pFYkj-0005L4-PZ; Wed, 11 Jan 2023 11:54:42 +0100 Message-ID: Date: Wed, 11 Jan 2023 11:54:41 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.6.0 Subject: =?UTF-8?Q?Re=3a_=5bRegression=5d_Bug=c2=a0216911_-_get=5funmapped?= =?UTF-8?Q?=5farea_returns_addresses_below_mmap=5fmin=5faddr?= Content-Language: en-US, de-DE From: "Linux kernel regression tracking (Thorsten Leemhuis)" To: "Liam R. Howlett" , "Matthew Wilcox (Oracle)" Cc: "regressions@lists.linux.dev" , LKML , Linux-MM , Amanieu d'Antras , "maple-tree@lists.infradead.org" , Andrew Morton Reply-To: Linux regressions mailing list , Linux regressions mailing list References: <0b9f5425-08d4-8013-aa4c-e620c3b10bb2@leemhuis.info> In-Reply-To: <0b9f5425-08d4-8013-aa4c-e620c3b10bb2@leemhuis.info> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-bounce-key: webpack.hosteurope.de;regressions@leemhuis.info;1673434486;7ca9abe9; X-HE-SMSGID: 1pFYkj-0005L4-PZ X-Rspamd-Queue-Id: A6A7D40003 X-Stat-Signature: s8x56q5gt998ran5bakn6m5m71rhth76 X-Rspam-User: X-Rspamd-Server: rspam08 X-HE-Tag: 1673434486-180435 X-HE-Meta: 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 bqA== 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: [resent with akpm's proper email address (either me or my mailer did something stupid; sorry for the noise)] On 11.01.23 11:46, Linux kernel regression tracking (Thorsten Leemhuis) wrote: > Hi, I noticed a regression report in bugzilla.kernel.org. As many > (most?) kernel developer don't keep an eye on it, I decided to forward > it by mail. Quoting from > https://bugzilla.kernel.org/show_bug.cgi?id=216911 : > >> Amanieu d'Antras 2023-01-11 02:10:02 UTC >> >> Created attachment 303572 [details] >> Program which demonstrates this issue >> >> The vm_unmapped_area function doesn't seem to respect info.low_limit and will sometimes return an address below this limit. This can result in addresses below mmap_min_addr being returned. >> >> I bisected it down to this range of commits (I stopped since I was hitting kernel crashes): >> 3499a13168da mm/mmap: use maple tree for unmapped_area{_topdown} >> 7fdbd37da5c6 mm/mmap: use the maple tree for find_vma_prev() instead of the rbtree >> be8432e7166e mm/mmap: use the maple tree in find_vma() instead of the rbtree. >> 2e3af1db1744 mmap: use the VMA iterator in count_vma_pages_range() >> f39af05949a4 mm: add VMA iterator >> d4af56c5c7c6 mm: start tracking VMAs with maple tree > > [those are all from the Maple Tree introduction series] > >> I've attached a test program which attempts to allocate the entire address space. On affected kernels, this triggers one of the 2 assertions (depending on whether you are running as root): >> - NULL is returned, which means memory below mmap_min_addr was allocated. >> - EPERM is returned, which really shouldn't happen when MAP_FIXED is not used (ENOMEM should be returned instead). > > See the ticket for more details. > > BTW, let me use this mail to also add the report to the list of tracked > regressions to ensure it's doesn't fall through the cracks: > > #regzbot introduced: d4af56c5c7c6..3499a13168da > https://bugzilla.kernel.org/show_bug.cgi?id=216911 > #regzbot title: mm: get_unmapped_area returns addresses below mmap_min_addr > #regzbot ignore-activity > > Ciao, Thorsten (wearing his 'the Linux kernel's regression tracker' hat) > -- > Everything you wanna know about Linux kernel regression tracking: > https://linux-regtracking.leemhuis.info/about/#tldr > If I did something stupid, please tell me, as explained on that page.