From nobody Sat Feb 7 11:38:06 2026 Received: from CO1PR03CU002.outbound.protection.outlook.com (mail-westus2azon11010049.outbound.protection.outlook.com [52.101.46.49]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 73E241DC997; Thu, 23 Oct 2025 03:05:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=52.101.46.49 ARC-Seal: i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761188745; cv=fail; b=fyPpjWRSwyd62cCcQlzqfq/gSutuuvTKX9FiYRxLo2JhyC15XD9XRzXhNAkCjV09eoj/dxVQV+IotsSmHnIZ1OYtc/mujjCsOXWPvW6Y0l9KD1+SkPriChBTV20JtP38E9aSBMg7ngJBR9vDN1c/ZsFR7tqrh2bVoLE5E/nxHDQ= ARC-Message-Signature: i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761188745; c=relaxed/simple; bh=Lc893xEKJsit5qj+j6Sg3J18MZwOkaBeIKnP+9cYQbI=; h=From:To:Cc:Subject:Date:Message-ID:Content-Type:MIME-Version; b=IYBjVmzu9PDLl7aUsv9LnCFpGzzjYTQSxH46Mh4m8xRGijmKsrsySb02IHU8WRTGY4sVLb42BGm4N+X8+hr4nqoFG3M1HTRLiD9f0g7VCsPcdDeDFB7MP6mPnO3sY6hRQgYpRIRyV6zivbpkdk+WPgwisSOKHncaaJC2pXl6F9A= ARC-Authentication-Results: i=2; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=nvidia.com; spf=fail smtp.mailfrom=nvidia.com; dkim=pass (2048-bit key) header.d=Nvidia.com header.i=@Nvidia.com header.b=I41138iJ; arc=fail smtp.client-ip=52.101.46.49 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=nvidia.com Authentication-Results: smtp.subspace.kernel.org; spf=fail smtp.mailfrom=nvidia.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=Nvidia.com header.i=@Nvidia.com header.b="I41138iJ" ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=i6v5WAZCd4bsuJr2mphLyJp+/kK/XbHUygc+Pm/25sH7PC9Ajs8mritVL8GElZm+5Ua7uvgi5DkefolO4dZQNsos1j0XTLcAhYonzs6s6beRoSHdmlyIT7ScphJmslQD3sokiSaxA8zHDJxjgfXmU/9+9Z92iwrsARXKqFI/x+jPn5qQH18HI0ueYREsh+6HJsIhRo0eYJRKkdJTFKi0zIp/P+gx4+SmNoY87nhsrIEMOlpcAge4N69y9LXIyIN6qNp2nYimws+0gJUEDyUeSom3wLysJf4dLmvCyMW47sLebAyCADRbjoYN6hoT4eg08B9WyFZGXoKmXkFvpd6iMA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector10001; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=ZHWyMUCW8X7ojbzK/5P+zWHFshBgJGZLdNvCh2kFTjo=; b=kSBZgwdBvJTgMZ2NBiICbov1JyKuah0c+VqSfQTQSsnubjNtQSaJUTkWAa0ejZ7Vy+sifQiMAevo096CbYqsSvbfUTYNQMNC7MsbtOV4VAWoX7wXIQOLMfrNcOnfKLU5xIP09F0yBCRlDZVcztO5Ovpv4ZybPOQz71J3ysANWHzeLAPioJZf25Pv5x+Wv4WtQNIN/jfCQSeihnwbJrdNfc5fUspfD1s697RauS297xy7VgYXOd4SBaURwT+lLpoykyCYXcQ7aX1DDMPCpAsxw0W4kRL/en0TVliXylvwhuKfPKb+/x28h3NDsEMIQlUBFP0iR8/ODjQFf3myH66O+Q== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=nvidia.com; dmarc=pass action=none header.from=nvidia.com; dkim=pass header.d=nvidia.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=Nvidia.com; s=selector2; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=ZHWyMUCW8X7ojbzK/5P+zWHFshBgJGZLdNvCh2kFTjo=; b=I41138iJUtzvSKUwqw+4AuSY6OH5s7Go0eb8VOB2xmpfH/oQ4t9ZAxhcBXqCfCqW3xEB0wR+38pG8/gglGEw3N7xF3ObaKuYXPfdauppp3fEWN4kUGFMmD9qKig4z/Fm0yY7dLj2cK3y7iySF+WSvGeRSlBdVTkQTHAQzLEqDY/Gz8YQ+t0me4Y+w6f/vnT+McFdwu8QcubF8FAkVRGuZfiHidL4drtm/NCJtCS5cS4TtHqGESMR5bddf+gJ5BoauWctWOSzi2AxsmscfUptpO590qJm0AYUpcS/B8wz9e8HWKM92VJgY6aCQZN+WyV19LRTnDKWuqtw/h4T5Xearw== Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=nvidia.com; Received: from DS7PR12MB9473.namprd12.prod.outlook.com (2603:10b6:8:252::5) by DM6PR12MB4156.namprd12.prod.outlook.com (2603:10b6:5:218::17) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.9253.13; Thu, 23 Oct 2025 03:05:40 +0000 Received: from DS7PR12MB9473.namprd12.prod.outlook.com ([fe80::5189:ecec:d84a:133a]) by DS7PR12MB9473.namprd12.prod.outlook.com ([fe80::5189:ecec:d84a:133a%5]) with mapi id 15.20.9253.011; Thu, 23 Oct 2025 03:05:40 +0000 From: Zi Yan To: linmiaohe@huawei.com, david@redhat.com, jane.chu@oracle.com Cc: kernel@pankajraghav.com, ziy@nvidia.com, akpm@linux-foundation.org, mcgrof@kernel.org, nao.horiguchi@gmail.com, Lorenzo Stoakes , Baolin Wang , "Liam R. Howlett" , Nico Pache , Ryan Roberts , Dev Jain , Barry Song , Lance Yang , "Matthew Wilcox (Oracle)" , Wei Yang , Yang Shi , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, stable@vger.kernel.org Subject: [PATCH v4] mm/huge_memory: preserve PG_has_hwpoisoned if a folio is split to >0 order Date: Wed, 22 Oct 2025 23:05:21 -0400 Message-ID: <20251023030521.473097-1-ziy@nvidia.com> X-Mailer: git-send-email 2.51.0 Content-Transfer-Encoding: quoted-printable X-ClientProxiedBy: MN2PR08CA0012.namprd08.prod.outlook.com (2603:10b6:208:239::17) To DS7PR12MB9473.namprd12.prod.outlook.com (2603:10b6:8:252::5) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: DS7PR12MB9473:EE_|DM6PR12MB4156:EE_ X-MS-Office365-Filtering-Correlation-Id: 11713250-4f28-47fc-d5e9-08de11e10c21 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|366016|7416014|376014|1800799024; X-Microsoft-Antispam-Message-Info: =?us-ascii?Q?SEF8nxi5NYmtdpvscvcrIafJ8nkR0KH7QVfTAnDJmirmYCsdnm3JaAfM0L8C?= =?us-ascii?Q?JkYxgo3TI6e4u7GjUk2L39Qs+iSGlznfDZVjyPNV85WR02PqTi8JR4dF8S8p?= =?us-ascii?Q?LZzYbVmrO8WdMokHf0XOiMfygqmdOp7UWJ5hhhvx5RkgWl6TkaV7mlOfgpGo?= =?us-ascii?Q?z+QH7tWZtP+qW3uC7D3l8sPloQr68DtNS+YPRakW5yuzZJr9H2j1xGQtBL9T?= =?us-ascii?Q?BEWArBj+bcru8PnEyRmZzY5Gpgy7v0c40PhjFAUAZl0LCjSab1Wf5FhxfjZc?= =?us-ascii?Q?Vwydi4k9moikNkjBL56yl0icYEnPk8LvdpLZOHhbbBQCEFnYHdfMSpPvS9/z?= =?us-ascii?Q?hrWfn5zgFOgfYfM7HGlhb1EX9r6PBKZamRCqLCrLX9EtniXer8wQqdfy5be3?= =?us-ascii?Q?XbfaumSOJ49/7kMB/5/FD8wWhCHPtw6ojfDQ7gpy4E+khi4lw8qPqLHh4r8w?= =?us-ascii?Q?9rHImonsR3zZQigE54UpbtGx/b9NaktkzG/K57SUBWiBVbqK41H7GDP4Vkk0?= =?us-ascii?Q?iJMxkFfN/MJTDCjGVQwGooM3bjbaPByf+Yw3UtmL3BNECb9LuNaacBBYTvcF?= =?us-ascii?Q?S7PQAMxXxD2uDcbjxmXqlRK8wvN3yapoZgWgC8cBEYpLhyzpHZG7Z84EpvRz?= =?us-ascii?Q?eGvAZEIl4xlGJ5KnABkJ9OeYXvZjWdDTdXnrvgMfiOS7F0MVbOTMCOSm9w3N?= =?us-ascii?Q?4ShC3zQx3OD4wY3c4vV300MRFhWpKeZgRcuD29D+3XMcAoB+BwD2V6D1AK/4?= =?us-ascii?Q?dcOiS1PqtqHf9vRbb969K84yubRd391XfqiId9zci7JTOP6ZFKnt0/HKfVI9?= =?us-ascii?Q?HYW6kYzR2Y9bnYSEqgvNVsvGnL+WN6dydn8pGuJhsPoNq79UdWYMnen80JDr?= =?us-ascii?Q?tYlHcFvdFbrbHQwuZzdNBOcpCJEixRmzzM86J2PaD/SZgoxeiz8ULenE0hRw?= =?us-ascii?Q?+z+o34oARJbb5fEhiPfYQ3yasTq9c77za5hC2a6DXufktuH7upgZq0DzdcY3?= =?us-ascii?Q?prWyz8PTIoUk/mOfZYiYu50JrlLq/jvOgQT5xBDGPIzAiGRlkTmPkOXOgIQy?= =?us-ascii?Q?7Kb3Sb4546uAXHoj0ovjnVmajRHhQpnhD6tTjaTpO00BkxjZT/7WeXM+h1qF?= =?us-ascii?Q?kQ3sPEa1ky0Z+cFuLxKYgbFopRT5az4yy8+Ldq4lHVRo/0D+Axdl8wfeQKG+?= =?us-ascii?Q?lyFM9yiy1+bjbAH699uIADCIzO75CR9ApAZGpcywGwpwmYK5PcFfGCxzv8Cc?= =?us-ascii?Q?dkQhgD9wJq/7pJhhj2fcYpkb2YLbmmuF3LKOF24hsUnwkSGLOueeFEa69zt6?= =?us-ascii?Q?Jz5FZfPcdcdWGA0ZOzax/hHQw+lN1Wv2jdA+F6So0IRpj1n/d6luGil86qFh?= =?us-ascii?Q?MR7qLlSDT/JFXkLXfSK4uBY07mxAxGCUOpiKCvarom4dlsTu2DM+8yHrhXwG?= =?us-ascii?Q?e7Xy+5UbO1KXJhP3LvKV/ZYfKrp9u+/c?= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:DS7PR12MB9473.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(366016)(7416014)(376014)(1800799024);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?01SaxQ4Vq9JwQ/mtZD80ie1g+j6aHmGOQIb6VQwEzZD5XyWxP6mf2OjVzq4v?= =?us-ascii?Q?zfh+N4dJIqSkJsZAad+OH62+0fNlcTioI8HrUEpr7oVodVi6L5Ep2fLWwSeo?= =?us-ascii?Q?kmyedrDWrXtlqXl0q6Gm3310JKbWjp4KN+2tNX0asbeT67FmYSFkrq7XkscU?= =?us-ascii?Q?zlVaytUYc/xNaSzI3I9O8JNYD7p+cc5orChZp2cbM0EZqE7UstR3qcPQsm+B?= =?us-ascii?Q?y87tJDbIMkgGN4ZVlTWbVwoq8bVkpDuSuaLgV5EDZ+LnnEzEVG+ykga2l9bD?= =?us-ascii?Q?Vw2DSVg4+KCPRuept8WlHftzdW5k0zusZUhbFeCJeYWX585Ymr7xYjIbeUQJ?= =?us-ascii?Q?XKancalTbmpdyWgUq6aWbrDRY/zPDPLkBotjBvZZqU1bU5bqHaCmDOw6yq9p?= =?us-ascii?Q?pJGeFh5Wom2dyaY8fm1dIrO1+Oh50jVIyvlCns6lA4IiBEwdHmUdGeGl+6lS?= =?us-ascii?Q?G1lQj5xEIQzXqj1b8NhDzMKb9yjdbCTu6CAATEAmhldXbHhTssmstIWuSPXF?= =?us-ascii?Q?mMe5OZqOVHe8iKiFwIhAcPW6fct+ai8RN61rZAF4Xm0h8XrQDyadMDoTana7?= =?us-ascii?Q?sOI+BvhzfwJ8HlfZp88T8X2M3ylYFpF55dLOBryzb3UCPXDF/eSb16GDmtTl?= =?us-ascii?Q?KS4eAOF8NHHVg0SZk852NLsO7For8AD2x68bHIxqaQlTW826sBISNdFkUDV7?= =?us-ascii?Q?RKD4VDdewvx8wbbrUJV28TE/FuLI9VnDWHAq6SZNOxJPL8HfmNIWHKf/zJAJ?= =?us-ascii?Q?93DxZKEBcjaTKoR1EWdyJ/ZgAPDEOJHICqoXHYkFQN/r+edUYDDC4kSduL0z?= =?us-ascii?Q?Srg6kWuujAtGR8ixM6yf6sJ/BOl70bmAw1ONwn2C0f/ZXuWYiJHgqlE9Xkzo?= =?us-ascii?Q?v09W2Kb0s09f6KLZomXiu02sjqO2eW9EBA1ZKpZmSMC7MgQDYbP9IG8747LY?= =?us-ascii?Q?QXxu33NWqBKGuKmc6b0XOUtXYdVAij3BECON4oH6denE25lnnsshOENqPnL8?= =?us-ascii?Q?rokJ8IAMhKu91lnlZzka8ob0YArZbYhLlqr2Zj6kjS88B4dyvtn2PYJwFUSM?= =?us-ascii?Q?l9VyRulygOxR+VGCNlxUq7x9vbaat5ENTCq/yNcYW/BX95LTuz05GI7O8dVj?= =?us-ascii?Q?lD1sFXjCYAtbT54IrlNIJXuCpbYQPagxntjL9tXt2I58TBxbSGDFaDyQoBp2?= =?us-ascii?Q?rWnF7h92KhHYc9YyMa5EUxCbVQJndHtMchdR+qtGE5sd+sg266tIowmiQeTd?= =?us-ascii?Q?x00nFGpfO/nNYBFoXRLaHM8Ko9eu7h03toMVZj2D7WX9AHKlV2aB1yUfAMaz?= =?us-ascii?Q?xx+4FW7WbTDNue+VenuqqfHR1FI2PNs+2PEpnlwaml4tK5UfH4IaPVbv/LwG?= =?us-ascii?Q?FUuNKweOopjZ9gOHE4uPE3IAU2b5T1sEh0voG92E53LfqQZiFxAeb9Z9rvBV?= =?us-ascii?Q?2jqqoBdeJcI1F4d3IUeXDelo6a8RQANgqt2VgT4sKHdyBmsO3/dFMD23GeNJ?= =?us-ascii?Q?g13LMR12iwHz50wF2QHcxdmMRBsbRGODWN3xFkhexBp/3euSDiVHh/yBhirq?= =?us-ascii?Q?kieXYoglwMY/GQK2tfch75fTR+P6VWzN5cNy4skY?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 11713250-4f28-47fc-d5e9-08de11e10c21 X-MS-Exchange-CrossTenant-AuthSource: DS7PR12MB9473.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 23 Oct 2025 03:05:40.3775 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: NPk39P+WUbnWB5Ew3EwlaoGVFzUhM0JKGA1qCroYtv51sQJmvopnUfeP/KJjA2y3 X-MS-Exchange-Transport-CrossTenantHeadersStamped: DM6PR12MB4156 Content-Type: text/plain; charset="utf-8" folio split clears PG_has_hwpoisoned, but the flag should be preserved in after-split folios containing pages with PG_hwpoisoned flag if the folio is split to >0 order folios. Scan all pages in a to-be-split folio to determine which after-split folios need the flag. An alternatives is to change PG_has_hwpoisoned to PG_maybe_hwpoisoned to avoid the scan and set it on all after-split folios, but resulting false positive has undesirable negative impact. To remove false positive, caller of folio_test_has_hwpoisoned() and folio_contain_hwpoisoned_page() needs to do the scan. That might be causing a hassle for current and future callers and more costly than doing the scan in the split code. More details are discussed in [1]. This issue can be exposed via: 1. splitting a has_hwpoisoned folio to >0 order from debugfs interface; 2. truncating part of a has_hwpoisoned folio in truncate_inode_partial_folio(). And later accesses to a hwpoisoned page could be possible due to the missing has_hwpoisoned folio flag. This will lead to MCE errors. Link: https://lore.kernel.org/all/CAHbLzkoOZm0PXxE9qwtF4gKR=3DcpRXrSrJ9V9Pm= 2DJexs985q4g@mail.gmail.com/ [1] Fixes: c010d47f107f ("mm: thp: split huge page to any lower order pages") Cc: stable@vger.kernel.org Signed-off-by: Zi Yan Acked-by: David Hildenbrand Reviewed-by: Lance Yang Reviewed-by: Lorenzo Stoakes Reviewed-by: Miaohe Lin Reviewed-by: Wei Yang --- From V3[1]: 1. Separated from the original series; 2. Added Fixes tag and cc'd stable; 3. Simplified page_range_has_hwpoisoned(); 4. Renamed check_poisoned_pages to handle_hwpoison, made it const, and shorten the statement; 5. Removed poisoned_new_folio variable and checked the condition directly. [1] https://lore.kernel.org/all/20251022033531.389351-2-ziy@nvidia.com/ mm/huge_memory.c | 23 ++++++++++++++++++++--- 1 file changed, 20 insertions(+), 3 deletions(-) diff --git a/mm/huge_memory.c b/mm/huge_memory.c index fc65ec3393d2..5215bb6aecfc 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -3455,6 +3455,14 @@ bool can_split_folio(struct folio *folio, int caller= _pins, int *pextra_pins) caller_pins; } =20 +static bool page_range_has_hwpoisoned(struct page *page, long nr_pages) +{ + for (; nr_pages; page++, nr_pages--) + if (PageHWPoison(page)) + return true; + return false; +} + /* * It splits @folio into @new_order folios and copies the @folio metadata = to * all the resulting folios. @@ -3462,17 +3470,24 @@ bool can_split_folio(struct folio *folio, int calle= r_pins, int *pextra_pins) static void __split_folio_to_order(struct folio *folio, int old_order, int new_order) { + /* Scan poisoned pages when split a poisoned folio to large folios */ + const bool handle_hwpoison =3D folio_test_has_hwpoisoned(folio) && new_or= der; long new_nr_pages =3D 1 << new_order; long nr_pages =3D 1 << old_order; long i; =20 + folio_clear_has_hwpoisoned(folio); + + /* Check first new_nr_pages since the loop below skips them */ + if (handle_hwpoison && + page_range_has_hwpoisoned(folio_page(folio, 0), new_nr_pages)) + folio_set_has_hwpoisoned(folio); /* * Skip the first new_nr_pages, since the new folio from them have all * the flags from the original folio. */ for (i =3D new_nr_pages; i < nr_pages; i +=3D new_nr_pages) { struct page *new_head =3D &folio->page + i; - /* * Careful: new_folio is not a "real" folio before we cleared PageTail. * Don't pass it around before clear_compound_head(). @@ -3514,6 +3529,10 @@ static void __split_folio_to_order(struct folio *fol= io, int old_order, (1L << PG_dirty) | LRU_GEN_MASK | LRU_REFS_MASK)); =20 + if (handle_hwpoison && + page_range_has_hwpoisoned(new_head, new_nr_pages)) + folio_set_has_hwpoisoned(new_folio); + new_folio->mapping =3D folio->mapping; new_folio->index =3D folio->index + i; =20 @@ -3600,8 +3619,6 @@ static int __split_unmapped_folio(struct folio *folio= , int new_order, int start_order =3D uniform_split ? new_order : old_order - 1; int split_order; =20 - folio_clear_has_hwpoisoned(folio); - /* * split to new_order one order at a time. For uniform split, * folio is split to new_order directly. --=20 2.51.0