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 7F103CDB47E for ; Mon, 16 Oct 2023 00:42:29 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 7BB396B0198; Sun, 15 Oct 2023 20:42:28 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 76A8C6B019C; Sun, 15 Oct 2023 20:42:28 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 60B8D6B019D; Sun, 15 Oct 2023 20:42:28 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id 4FAAF6B0198 for ; Sun, 15 Oct 2023 20:42:28 -0400 (EDT) Received: from smtpin07.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay05.hostedemail.com (Postfix) with ESMTP id 1506D409B3 for ; Mon, 16 Oct 2023 00:42:28 +0000 (UTC) X-FDA: 81349473576.07.637BEE4 Received: from mailout1.samsung.com (mailout1.samsung.com [203.254.224.24]) by imf12.hostedemail.com (Postfix) with ESMTP id 83D9B40009 for ; Mon, 16 Oct 2023 00:42:23 +0000 (UTC) Authentication-Results: imf12.hostedemail.com; dkim=pass header.d=samsung.com header.s=mail20170921 header.b=PeDRdZNL; dmarc=pass (policy=none) header.from=samsung.com; spf=pass (imf12.hostedemail.com: domain of hyesoo.yu@samsung.com designates 203.254.224.24 as permitted sender) smtp.mailfrom=hyesoo.yu@samsung.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1697416944; a=rsa-sha256; cv=none; b=OZmeFTxJYBSJ25mJJVMt/NG+NmJ6gjeIMDR+CQp7iAM9xaLmO/E3hSbageshgOC7dhMHyb DPuWVal4Vx1P83OWGTD/XcJDZY90jH0L0OdknjdBDzdgXBSCXb4ucMZCV8nck9iqAQt//p Sjq0YjRw8V1oXCC7edjWyrOlZr1XlTI= ARC-Authentication-Results: i=1; imf12.hostedemail.com; dkim=pass header.d=samsung.com header.s=mail20170921 header.b=PeDRdZNL; dmarc=pass (policy=none) header.from=samsung.com; spf=pass (imf12.hostedemail.com: domain of hyesoo.yu@samsung.com designates 203.254.224.24 as permitted sender) smtp.mailfrom=hyesoo.yu@samsung.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1697416944; h=from:from:sender: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: in-reply-to:in-reply-to:references:references:dkim-signature; bh=4thdf5vOiLjNrlhR2orFClc4haODcBFO8AN2JFM2cnA=; b=tSuyAt4S/lFyVGtmbfHeiyr67UsR8AJTao6QtDbnimpmucz6DkSutXXhjectaNHYLKQeXK y+gZObhEHpOPS59oAj5fqBGjd5ICbSAQQpM+NjalBQIfdLL9VIdryp1P9Dos5ltSS2XWT0 jMrgFXHFX7w0LTDLyzM7kGQNQinleOE= Received: from epcas2p4.samsung.com (unknown [182.195.41.56]) by mailout1.samsung.com (KnoxPortal) with ESMTP id 20231016004219epoutp013fad5253c8d13e8db7720cb5a755c6d8~Ob7amAgz00100201002epoutp01T for ; Mon, 16 Oct 2023 00:42:19 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 mailout1.samsung.com 20231016004219epoutp013fad5253c8d13e8db7720cb5a755c6d8~Ob7amAgz00100201002epoutp01T DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=samsung.com; s=mail20170921; t=1697416939; bh=4thdf5vOiLjNrlhR2orFClc4haODcBFO8AN2JFM2cnA=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=PeDRdZNLcuLh7z5g9kFSW/wk51LkiJZyDZQ+6SUroc/HLojJ4caiDrbV3i3TaArFt fy/JhrNOF5Q2QF/oRySNRxBPYUGH+ZRy7xf/pzmENqE2ftxHgIhxN3gOp6kcgpoUWN xG0VMBYgrbNRAKo5KkZ6OBPDb5lgci4Tr9fM/z0w= Received: from epsnrtp3.localdomain (unknown [182.195.42.164]) by epcas2p4.samsung.com (KnoxPortal) with ESMTP id 20231016004219epcas2p4cf1710a7794b601974475673c85d50e4~Ob7aTVSqS2621026210epcas2p4K; Mon, 16 Oct 2023 00:42:19 +0000 (GMT) Received: from epsmgec2p1-new.samsung.com (unknown [182.195.36.70]) by epsnrtp3.localdomain (Postfix) with ESMTP id 4S7yxQ6vHCz4x9QC; Mon, 16 Oct 2023 00:42:18 +0000 (GMT) Received: from epcas2p4.samsung.com ( [182.195.41.56]) by epsmgec2p1-new.samsung.com (Symantec Messaging Gateway) with SMTP id B6.1D.18994.AE68C256; Mon, 16 Oct 2023 09:42:18 +0900 (KST) Received: from epsmtrp2.samsung.com (unknown [182.195.40.14]) by epcas2p1.samsung.com (KnoxPortal) with ESMTPA id 20231016004218epcas2p19472bf83c7e69f73326a07141a021d98~Ob7ZZXoos1597115971epcas2p1-; Mon, 16 Oct 2023 00:42:18 +0000 (GMT) Received: from epsmgms1p1new.samsung.com (unknown [182.195.42.41]) by epsmtrp2.samsung.com (KnoxPortal) with ESMTP id 20231016004218epsmtrp2b0992bb1f664dfed8e0b16647463804c~Ob7ZYyDpF1181411814epsmtrp2n; Mon, 16 Oct 2023 00:42:18 +0000 (GMT) X-AuditID: b6c32a4d-9f7ff70000004a32-e2-652c86ea40fc Received: from epsmtip2.samsung.com ( [182.195.34.31]) by epsmgms1p1new.samsung.com (Symantec Messaging Gateway) with SMTP id 19.57.08755.AE68C256; Mon, 16 Oct 2023 09:42:18 +0900 (KST) Received: from tiffany (unknown [10.229.95.142]) by epsmtip2.samsung.com (KnoxPortal) with ESMTPA id 20231016004218epsmtip2ce75f3cb6e92d4aa50e617a76f01c8aa~Ob7ZPUyhD2150521505epsmtip2z; Mon, 16 Oct 2023 00:42:18 +0000 (GMT) Date: Mon, 16 Oct 2023 09:32:00 +0900 From: Hyesoo Yu To: Vishal Moola Cc: Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] mm: page_alloc: check the order of compound page event when the order is 0 Message-ID: <20231016003200.GA445850@tiffany> MIME-Version: 1.0 In-Reply-To: X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFvrBKsWRmVeSWpSXmKPExsWy7bCmhe6rNp1Ug952C4s569ewWVzeNYfN 4t6a/6wW6/fdYHVg8dg56y67x6ZPk9g9Tsz4zeLxeZNcAEtUtk1GamJKapFCal5yfkpmXrqt kndwvHO8qZmBoa6hpYW5kkJeYm6qrZKLT4CuW2YO0EolhbLEnFKgUEBicbGSvp1NUX5pSapC Rn5xia1SakFKToF5gV5xYm5xaV66Xl5qiZWhgYGRKVBhQnbGqQfP2AoOCVQ0TZvJ3sC4k7eL kZNDQsBEYk33HZYuRi4OIYE9jBK33u1ihXA+MUqcON7LDOF8Y5RoaVvNDtPStH8LVGIvo8TW S6uYIJynjBL3t70Hcjg4WARUJa7+cAFpYBNQlzixZRkjSFhEQFNi5d8kkDCzQKLE36nrwWYK A9k7mzewgdi8AroSK96cZIGwBSVOznwCZnMKOEkcW/SZCeKGS+wS1/sDIGwXiY5vt5khbGGJ V8e3QN0pJfH53V42CDtb4u7HCVB2icS6Mw1QNcYSs561M0Lcky7xY98TNpAzJQSUJY7cYoEI 80l0HP7LDhHmlehoE4LoVJbYv2weC4QtKfFobTsrRImHRNeeeEh4nGCU+D5rCvsERrlZSJ6Z hWQZhK0jsWD3JyCbA8iWllj+jwPC1JRYv0t/ASPrKkap1ILi3PTUZKMCQ9281HJ4DCfn525i BCdBLd8djK/X/9U7xMjEwXiIUYKDWUmENz1YJ1WINyWxsiq1KD++qDQntfgQoykwbiYyS4km 5wPTcF5JvKGJpYGJmZmhuZGpgbmSOO+91rkpQgLpiSWp2ampBalFMH1MHJxSDUycXMqXGMJ1 ZxrNe896RXO1+MRzF9+GZOwtP7i39ZHfbMXqQyvufF1/XuCX6JOvNXbmc05s9016F7PzlY6n ebeIqc3WDQoKU3OWpkrv+S8nJuVwvGaVv/0c35n7lq85N2PKsjWbXqh/1NGys1606uTarQUy x8Ms2rc/uxH5WcZojk1A+bwzedX50wwKmiuvzq73fSbyWsfIzfuRCePCqhmfOxutzh69t6vP 6IjCxjXPNslNsn6/sMuW5SPT82UNVlP13/2JjGB3fSV8+kdhULKzw2FeNmPv/s3tpew7dN/W fHnfdtNgbXnAh2v9m6+cte79t8V0544NPJwM+6ftmHQugPfcFcZFwuybtk3KuXDmmBJLcUai oRZzUXEiAL5ewbELBAAA X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFtrNLMWRmVeSWpSXmKPExsWy7bCSvO6rNp1Ug0/3ZCzmrF/DZnF51xw2 i3tr/rNarN93g9WBxWPnrLvsHps+TWL3ODHjN4vH501yASxRXDYpqTmZZalF+nYJXBnPvhoU tPJVHH7Yw9TAOJW7i5GTQ0LARKJp/xbmLkYuDiGB3YwSC26fY4FISErM+nySCcIWlrjfcoQV ougxo8SOYxvZuhg5OFgEVCWu/nABqWETUJc4sWUZI0hYREBTYuXfJJAws0CixN+p69lBbGEg e2fzBjYQm1dAV2LFm5MsECNPMEr8+7aLGSIhKHFy5hMWiGYtiRv/XjKBzGQWkJZY/o8DJMwp 4CRxbNFnpgmMArOQdMxC0jELoWMBI/MqRsnUguLc9NxiwwLDvNRyveLE3OLSvHS95PzcTYzg 8NXS3MG4fdUHvUOMTByMhxglOJiVRHjTg3VShXhTEiurUovy44tKc1KLDzFKc7AoifOKv+hN ERJITyxJzU5NLUgtgskycXBKNTAll12TPOjc+nXa28MnyhI5tjzbbn187mS/oOZv17nuWnNt +KHEYqR5+aOdidwK0z1Sh9+zR3083NB9XuWLknKfYJG02SPDbfcuNnlU3LfYdtRwes7tjV+L vk3L4Pq14mSr6i9uNTbJBr0Lm4r4ruYZJV9ds/b15z1PD99Jl5BIE3ExPnHtsLVDgp73hd2X C8Qf7vztwaZbcH3NehOzkEqj+X6xuqqhMX6V/7JmOdq+lHFynvJbrcHypPlptu3RJt90FLP8 7q2emHx2/eSjCk5T42MaWeweLPmUfGD/ISEuh1kpm5wbr05l2v268fuFyn+RH9n4BKS9ZBbK Rdwt+GzSkO0k+6risOfU8oNXFU8osRRnJBpqMRcVJwIA4uZzW84CAAA= X-CMS-MailID: 20231016004218epcas2p19472bf83c7e69f73326a07141a021d98 X-Msg-Generator: CA Content-Type: multipart/mixed; boundary="----.DGRwfvtDKQaTon4q7jBZTz_rY-uYfv-SaOoriR32EfX1D_r=_7c95_" X-Sendblock-Type: AUTO_CONFIDENTIAL CMS-TYPE: 102P DLP-Filter: Pass X-CFilter-Loop: Reflected X-CMS-RootMailID: 20231012012153epcas2p34b8e9e8a898ace8d50411cadf937ef5d References: <20231012011106.2425309-1-hyesoo.yu@samsung.com> X-Rspam-User: X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: 83D9B40009 X-Stat-Signature: 51fwj9um7rtigg4gcm1k9arnpkd33a8a X-HE-Tag: 1697416943-608938 X-HE-Meta: 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 XrSqe4XE b4gBj38Gp9gKBtSSgonSgtmXDrqc6CMTxFyshwDddDfSJ+20Bpv7c6q9LWoXuD7mgj/xo3rO1yJe1/AVmMg1l9/inPHMBZTZ7+akhuf1VexlryR2brs9LTqssUKbhztJw3oZbcLx3ARvGwgzk1sSn0aQuV5YEflWGaYREdJ5Eg66c911j2XOKGA2eO/C/aLfcZ5X+XFp4b6Eq18BsziUroZhebgga3tb3Rb/KZ0Y7ozFuYafvVeYfNwYpnT7tClXBZYauTQ5Y8c7f/Cf1TdLp/u0sOQ== 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: ------.DGRwfvtDKQaTon4q7jBZTz_rY-uYfv-SaOoriR32EfX1D_r=_7c95_ Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline On Fri, Oct 13, 2023 at 01:54:08PM -0700, Vishal Moola wrote: > On Thu, Oct 12, 2023 at 10:11:06AM +0900, Hyesoo Yu wrote: > > For compound pages, the head sets the PG_head flag and > > the tail sets the compound_head to indicate the head page. > > If a user allocates a compound page and frees it with a different > > order, the compound page information will not be properly > > initialized. To detect this problem, compound_page(page) and > > the order are compared, but it is not checked when the order is 0. > > That error should be checked regardless of the order. > > I believe all compound pages are order >= 1, so this error can't occur > when the order is 0. > Yes. All compound pages are order >= 1. However if the user uses the API incorrectly, the order value could be zero. For example, addr = alloc_pages(GFP_COMP, 2); free_pages(addr, 0); (struct page[16])0xFFFFFFFE21715100 = ( (flags = 0x4000000000000200, lru = (next = 0x0, prev = 0xDEAD000000000122),// Clear PG_head (flags = 0x4000000000000000, lru = (next = 0xFFFFFFFE21715101, prev = 0xFFFFFFFF00000201), // Remain compound head It is memory leak, and it also makes system stability problem. on isolation_single_pageblock, That case makes infinite loops. for (pfn = start_pfn; pfn < boundary_pfn; ) { if (PageCompound(page)) { // page[1] is compound page struct page *head = compound_head(page); // page[0] unsigned long head_pfn = page_to_pfn(head); unsigned long nr_pages = compound_nr(head); // nr_pages is 1 since page[0] is not compound page. if (head_pfn + nr_pages <= boundary_pfn) { pfn = head_pfn + nr_pages; // pfn is set as page[1]. continue; } } So, I guess, we have to check the incorrect use in free_pages_prepare. Thanks, Hyesoo Yu. ------.DGRwfvtDKQaTon4q7jBZTz_rY-uYfv-SaOoriR32EfX1D_r=_7c95_ Content-Type: text/plain; charset="utf-8" ------.DGRwfvtDKQaTon4q7jBZTz_rY-uYfv-SaOoriR32EfX1D_r=_7c95_--