From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx0a-00069f02.pphosted.com (mx0a-00069f02.pphosted.com [205.220.165.32]) (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 B50F82D29A9; Tue, 12 Aug 2025 17:32:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=205.220.165.32 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755019969; cv=fail; b=M6whEEgLfDIfXRxAyromgjfv3qBGA7JbvD0h5BoWya4w6SECPkcV6XMfSs4+NCx/XDZ1hrbWRGowCPX5FLkqA+z4qtdexJDchg1vXjYCg0OHz5lApbcbiy6Mx5qHnqIoam3RtQe1ykrpYSW7BLAvza3NpfImGcsY2T3evU/+y/o= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755019969; c=relaxed/simple; bh=uLk6cyIcGbCe/IE8z8jlMyne8XCnGdX+8eu4kXM62Aw=; h=Date:From:To:Cc:Subject:Message-ID:References:Content-Type: Content-Disposition:In-Reply-To:MIME-Version; b=hCsO7Ll8PcN9HRRWMrAdD4G3I0NWKaSwhsK+neE73W2qVK4H3rMrmm3oJysyEVbM3VKhCjArpNZKwRwbmXtR/xWg/xxYeg2LfYQLKX8H1jKII9+UAq5e1skdVvdddIS+V0u+bA//ELzGOHSs005Z8O8XXvWpfbGvdxXzlE+Er3s= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=oracle.com; spf=pass smtp.mailfrom=oracle.com; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b=VgCwdkwj; dkim=pass (1024-bit key) header.d=oracle.onmicrosoft.com header.i=@oracle.onmicrosoft.com header.b=QCF46kmu; arc=fail smtp.client-ip=205.220.165.32 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=oracle.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=oracle.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="VgCwdkwj"; dkim=pass (1024-bit key) header.d=oracle.onmicrosoft.com header.i=@oracle.onmicrosoft.com header.b="QCF46kmu" Received: from pps.filterd (m0246627.ppops.net [127.0.0.1]) by mx0b-00069f02.pphosted.com (8.18.1.2/8.18.1.2) with ESMTP id 57CDC0IZ021868; Tue, 12 Aug 2025 17:32:03 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=cc :content-type:date:from:in-reply-to:message-id:mime-version :references:subject:to; s=corp-2025-04-25; bh=/o1ZEJJAxxggij6O/q UVlPcji9vQ4O8hW8fTrRBWpgs=; b=VgCwdkwj1vVs5N1haNLUAyG2Yi3fLqhyo1 anpw7WAqrxSs5fOydkGBH8HsQRs8/y28zQM+a+9meGedXx3321KVCASolULVVnuJ xk76x9zxmQyXKowu+MJicCv4HUhPIzjj6Cj2BdJiG5Nr7yY0vW5mJFIncSvOZ5ET tPh9N149BmBnuqaAbU9FElUp4e71cuibtXE7lnivqagIRfMRAd3yxcRzTdV57cWi xIh3951+PU5VY3W28hpRKlNJt4y7Z1SzItGxAmGNTTsYkl/WaC/Fgb4KjzKgZWYf dM+mFHOj161OPH2+O9gLobAJ4fdaPe9RcWJTKyImVF206Un+4rbQ== Received: from iadpaimrmta03.imrmtpd1.prodappiadaev1.oraclevcn.com (iadpaimrmta03.appoci.oracle.com [130.35.103.27]) by mx0b-00069f02.pphosted.com (PPS) with ESMTPS id 48dvx4d8sg-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 12 Aug 2025 17:32:02 +0000 (GMT) Received: from pps.filterd (iadpaimrmta03.imrmtpd1.prodappiadaev1.oraclevcn.com [127.0.0.1]) by iadpaimrmta03.imrmtpd1.prodappiadaev1.oraclevcn.com (8.18.1.2/8.18.1.2) with ESMTP id 57CGV8pS038595; Tue, 12 Aug 2025 17:32:01 GMT Received: from nam11-dm6-obe.outbound.protection.outlook.com (mail-dm6nam11on2044.outbound.protection.outlook.com [40.107.223.44]) by iadpaimrmta03.imrmtpd1.prodappiadaev1.oraclevcn.com (PPS) with ESMTPS id 48dvsgtg1y-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 12 Aug 2025 17:32:01 +0000 ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=WiGy7CzhYBKb/UExUTnSeaxhkkMXdN78rJiHHJlk27nx0fEHUl1SjOu/KhaqBI9iQu1NClrVeDkYQr2IwbPe+yyqKQ8erfjh7n95UgcH+U6UJiCgjJQxmtUyKZJNvrkKWVKZ+w3UbNhabV0zPMJ4tXALlR4NCxvm5X0cn3vq8pXpEVnCd/uF40lnBqQC/ZUDXr82g0TeO3FFVvl6ZRgCx8+9PvGD9O+jAvoShh+zy1j+APMUjETBCmVlttlWgtY5XQrrThpMDCY7yhJia1L+8FosvXZekqKGLPitPFpvNqcvRpPpr5z0+2hAkdW48+6gyWlYHfkUnVFDQA7wB5LEvQ== 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=/o1ZEJJAxxggij6O/qUVlPcji9vQ4O8hW8fTrRBWpgs=; b=LYgXh5d8J4rSU1CcJAT1kvKxX73dGMs7CMpkbUApGClSLuLR6Nb8vVFn2u+Eu4k10xzfP1uS2gr89ukA/zfgz+bK+a0LhlDaiCUizchmwRL+n8+PndbK8d0gMoTZ8emwPULGSmklV6CX8iproO5MQgvMUrfYHfIolIyuyZu6AgrUJW/epqpezTsvxxaRQxzOXvCRbkjM1cWzU5423/54TdS1ZE6gTIW77B4ddcP0Ns+n+xQvxbT6yNVbub079D5JIi5A2bQR1KXJqS8uJzBxFKH1pXtvYiwe0sa+Aawbwh95k54liFw2fGEcVoVzoT8rwamP/aPMsttuO1JwChaSuA== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=oracle.com; dmarc=pass action=none header.from=oracle.com; dkim=pass header.d=oracle.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.onmicrosoft.com; s=selector2-oracle-onmicrosoft-com; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=/o1ZEJJAxxggij6O/qUVlPcji9vQ4O8hW8fTrRBWpgs=; b=QCF46kmuNrNc2VIRmTv76yuPsjfDFDXYW4NMV+OgcWoBrQKVpPRkA6taONRytJfH9aEPwrKjNHO5NjRwqthkWesykiQRtuAWBK8u7XIaZsnG4BVvXG7glTmTe5y6MoDY4nbfPTK3chr5cmSDz89hWJUfn8l7QSCBvqgvm8TnBn0= Received: from PH0PR10MB5777.namprd10.prod.outlook.com (2603:10b6:510:128::16) by CO1PR10MB4515.namprd10.prod.outlook.com (2603:10b6:303:9b::23) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.9031.14; Tue, 12 Aug 2025 17:31:57 +0000 Received: from PH0PR10MB5777.namprd10.prod.outlook.com ([fe80::75a8:21cc:f343:f68c]) by PH0PR10MB5777.namprd10.prod.outlook.com ([fe80::75a8:21cc:f343:f68c%5]) with mapi id 15.20.9031.012; Tue, 12 Aug 2025 17:31:57 +0000 Date: Tue, 12 Aug 2025 13:31:50 -0400 From: "Liam R. Howlett" To: Lorenzo Stoakes Cc: Andrew Morton , Alexander Gordeev , Gerald Schaefer , Heiko Carstens , Vasily Gorbik , Christian Borntraeger , Sven Schnelle , "David S . Miller" , Andreas Larsson , Dave Hansen , Andy Lutomirski , Peter Zijlstra , Thomas Gleixner , Ingo Molnar , Borislav Petkov , "H . Peter Anvin" , Alexander Viro , Christian Brauner , Jan Kara , Kees Cook , David Hildenbrand , Zi Yan , Baolin Wang , Nico Pache , Ryan Roberts , Dev Jain , Barry Song , Xu Xin , Chengming Zhou , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , David Rientjes , Shakeel Butt , Arnaldo Carvalho de Melo , Namhyung Kim , Mark Rutland , Alexander Shishkin , Jiri Olsa , Ian Rogers , Adrian Hunter , Kan Liang , Masami Hiramatsu , Oleg Nesterov , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , Valentin Schneider , Jason Gunthorpe , John Hubbard , Peter Xu , Jann Horn , Pedro Falcato , Matthew Wilcox , Mateusz Guzik , linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org, sparclinux@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-trace-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org Subject: Re: [PATCH 08/10] mm: update fork mm->flags initialisation to use bitmap Message-ID: Mail-Followup-To: "Liam R. Howlett" , Lorenzo Stoakes , Andrew Morton , Alexander Gordeev , Gerald Schaefer , Heiko Carstens , Vasily Gorbik , Christian Borntraeger , Sven Schnelle , "David S . Miller" , Andreas Larsson , Dave Hansen , Andy Lutomirski , Peter Zijlstra , Thomas Gleixner , Ingo Molnar , Borislav Petkov , "H . Peter Anvin" , Alexander Viro , Christian Brauner , Jan Kara , Kees Cook , David Hildenbrand , Zi Yan , Baolin Wang , Nico Pache , Ryan Roberts , Dev Jain , Barry Song , Xu Xin , Chengming Zhou , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , David Rientjes , Shakeel Butt , Arnaldo Carvalho de Melo , Namhyung Kim , Mark Rutland , Alexander Shishkin , Jiri Olsa , Ian Rogers , Adrian Hunter , Kan Liang , Masami Hiramatsu , Oleg Nesterov , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , Valentin Schneider , Jason Gunthorpe , John Hubbard , Peter Xu , Jann Horn , Pedro Falcato , Matthew Wilcox , Mateusz Guzik , linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org, sparclinux@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-trace-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org References: <9fb8954a7a0f0184f012a8e66f8565bcbab014ba.1755012943.git.lorenzo.stoakes@oracle.com> Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <9fb8954a7a0f0184f012a8e66f8565bcbab014ba.1755012943.git.lorenzo.stoakes@oracle.com> User-Agent: NeoMutt/20250510 X-ClientProxiedBy: YT1P288CA0014.CANP288.PROD.OUTLOOK.COM (2603:10b6:b01::27) To PH0PR10MB5777.namprd10.prod.outlook.com (2603:10b6:510:128::16) Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: PH0PR10MB5777:EE_|CO1PR10MB4515:EE_ X-MS-Office365-Filtering-Correlation-Id: 766c668c-668a-47b8-07a0-08ddd9c62328 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|7416014|376014|1800799024|366016; X-Microsoft-Antispam-Message-Info: =?us-ascii?Q?5QktSXi1Y7FB0KlWZlDb5mbX7IOl8X7cVBcXYkyV5fIUX+fAXEjlJoce6S9J?= =?us-ascii?Q?JRWYRjWq7GHlxPt+qX7+qXInOyHKOGgrhA1KNAXcsh7rytoq+75Z52kKdbNg?= =?us-ascii?Q?pun+9Cm7vsQ7+o4EwZUK/eKMY+rUiTRvkGrHSb+ISzcpsXmZiWmQAN6rRO+M?= =?us-ascii?Q?BL49GxPTB+WukZGIFYeaBu+wnRmzr9aPEp7ISYyuz8RmK1SXvjuRfmkS2SOx?= =?us-ascii?Q?+/z2GvEqKNm7IrafxDu3+9PTXpp6PrDlQ5SRBLGtvAg/KT8NqLcHM0Ic/Kbq?= =?us-ascii?Q?fEOjD7B3jB2mC6tN6kItslZ+y79BQp+WPdkZNA/0JiqEM0LbClbFGLqKYrSI?= =?us-ascii?Q?OivoVOVyRIEop9gLJtojuBwHpwoVtq6wtLotjEq/P1/jgzER2m9rYCsK/1YP?= =?us-ascii?Q?il2QnKEpIcxSE4p+v90ibHsckrM/sr806jrw7WY+iiyKdtzpXVjF3lPIzgE6?= =?us-ascii?Q?6zJmTddCrYY7AoY6r18ZUPfzK8MEk+MUZXthmLCMvFaLZ+gCX09+spVX99XI?= =?us-ascii?Q?U5t6fFYW3i6qFUMkvNhJrRR1XQVuuM8J87xjH+SBzGe6eKeyCCxdWc25cYMF?= =?us-ascii?Q?DAJS0Z2b+hlMRd/eC32TOfrwWpBFtAiFXe0sKe1LNpWpUKA8Q9pgtZXmaZ0A?= =?us-ascii?Q?zESEmw+9QkKPph2ZcF4i6tMDcGah6Zm1lh13zg3+Bvn/yFJo+yWrfrxssG+5?= =?us-ascii?Q?GxiYfpO6PGbAo0p/uQRYfEp2ru5SWHtkCHRz8oRWav8Qzl9RplDr4avJ2xPA?= =?us-ascii?Q?wk4/qY4EHGLDvLkYAUIVTYN8mW6oXXOXJf2AhD9+RAc/MYUlXWs7HnjuaryL?= =?us-ascii?Q?LWUwf+eAb94UdNMnQK7NOhqC6HdVx2pbP17OtHiXcgI4JX2biisLYtK5udS2?= =?us-ascii?Q?gjcf+tGjNSyR5hlmrW/qYC/ypndyeyLbMwdjm/5IFjjXjNJMyw5AhACt5it5?= =?us-ascii?Q?frpiIoSPwHu6PPpZQJa4ZesRAMr094lES6OxjZ8O8OLAGddv57EMVcvWjcLl?= =?us-ascii?Q?bUax1PjVP6uh/y3INISas0cUtFcd7yRcsc7/XEylj6ZliVvwPFsdLPQykJf1?= =?us-ascii?Q?OZrGMTtS0PkS6X4zVLQ9ypTJya4FZGNXBg4be9Kq63Hi2A2myhtBt+zzGav5?= =?us-ascii?Q?n08hmBneM5j1ThWIOK/KfaPYDL0McRhf1haxHDupA1wajNliqK37kyDxqGU1?= =?us-ascii?Q?elvn6VFYH1rfqBtjsSt2Um/GkISiimycZjsGeAa7lMfDzostGap9x1xyLEl+?= =?us-ascii?Q?42FJ9vyGedeIMS3xigdTf+3wm52HaUZPRFlyy4QRFPYmvzZj6yKvQSOWam1r?= =?us-ascii?Q?ecfQQs8sPQgiUnrmeAOWYldbiHoswXuLED/s0rGfOS4PUqHtOUxLloORcVi+?= =?us-ascii?Q?AhFNYmVSIOVPQUZS5gSlPmG5lNw6cQgR1KPLr2kccM+GgyjxB6+1yrdkeOkv?= =?us-ascii?Q?eBn7EEvq5LI=3D?= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:PH0PR10MB5777.namprd10.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(7416014)(376014)(1800799024)(366016);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?B+LEUnWR5DDzX4MjapnPirKH+YXO4xpoDUyW43MSW8IGJxdQgj2wiLOygwGO?= =?us-ascii?Q?MFq187sfdwaz6lYcRD2MBC+B2+z8Vv2Oo0Vmz6KCBccbczTUlyu1MMWLfXRs?= =?us-ascii?Q?YEPhnxxeAM5OcsRfH5WSqCcBCWGji0jEjNtqFLAoPghM/iYETwaR45Nob2pm?= =?us-ascii?Q?Tadu4dEjGF39R2bWPrqvL6z40VlD5oHjEGoyChWllKAP3CxmXzV4o19Bnbyq?= =?us-ascii?Q?T8jvEqDlzpM9x9rq/wPp4w1UMr720xIT+c/AwpnCw6FsF1mokPwoyV7lPAPZ?= =?us-ascii?Q?byVkZqjjm365v6okDRto+v0BIjEigDHEI/XhOu/dOM0WgHLdikN7ZRDzLp21?= =?us-ascii?Q?J5JAePDfqj645kHKnRSctu4EB94A0rDBOOG7A/tFP8a3mswak1ZP1XwnqJfi?= =?us-ascii?Q?/zQlmcoCWqctSjkeGgZf+aRDpurYHif9471LMSZZwNRBCh7AaIuXAscOLUKg?= =?us-ascii?Q?qk6O+H/3XECmMXLiG4CG2Ynmo0pGm5EmUQWAgLB4ofeChEwspz0dJT9u48Qc?= =?us-ascii?Q?9iMdWwyyi7Fa9W+GhcFm3fSSU4wOgnoyptbEqEj2EbmfUs+H0D3AWcnc98Ui?= =?us-ascii?Q?4S+4hLjdi/rIcZEtNhdqNMiEBvJweXNn5Tnc5iyKOPJbXJrjb/Ft9M0Lll6h?= =?us-ascii?Q?R10ay5R2PjPD4dpUACIYN7SSxZGjo0OLmjJANqo2rQrVG90UUxVyBoDc92sz?= =?us-ascii?Q?melzH/4Uken/RKTiKqF+6Yyj0G2W5X+AdST4L53wFmRQQSS/2rGV6Jux7MlT?= =?us-ascii?Q?HRkuGe2pX3qKIzxgEO4QFhZvFEtGJ68YPzbD6jxoeT7b1Ymt2QOyAfGldDE4?= =?us-ascii?Q?xDJ8DTyg5nr/MBtaKnfrLf7VpqR6FyNcen6vp5Kd/NyrtA0kIZbsQXbeDwAs?= =?us-ascii?Q?UvPj9Y5WAcIR69cbifeDoKA5b+Qa1nA5PMcimfSuKzFGme7HvQtMatAeGwU4?= =?us-ascii?Q?82gqxxctWMqqHlDfXWWpw/xPYanxZCKOqAx7cxWRGERWfkyABbdZa4h9VAGw?= =?us-ascii?Q?LzcDfTHzjpPCNj7mf7x6pmBGGrroK4gGdYtjyZpxxBFl7grAWgcqAgNL9O7d?= =?us-ascii?Q?cIE06KYOjS2D6eINpMqBD6fC5zt9rl9pfnSFVNELz11STEWsHuEm1ehDXZfh?= =?us-ascii?Q?FDGuAZ6+Vzhu+klKanxtTMQCmcsSS5c8Sd7oMtA7fHg4ik3Qk43x46fO7Sju?= =?us-ascii?Q?O90qEmwJ7ECTC2zOZeE5yopL0h4y2xBY5p36FepCci/93+z+s+W8yPCFHLXC?= =?us-ascii?Q?4CzNlPsTBRtpprL9XBqQQXFhVLoc4vgglV7yeUnoon6hNrfTaDMDkB0NgDab?= =?us-ascii?Q?cWoyblpYfiNDi1Cjrbl9deqw6HIe3HBLz3yueQtLrQ7oI3za21X6/C/8AioW?= =?us-ascii?Q?TaGVnGfq8KUdlqQFwxIxvG566sQV2u4JuN3NVEbkUkFrdqhlvx0K4Y8SqhLv?= =?us-ascii?Q?hlgh3C565oxJ8Jk4aDWqNUDcrZAg5CsQ1avVNh1CqJBWnXzndiZ4esbhE1eA?= =?us-ascii?Q?sG7/l/W0tObDI7Afs0VLF3IN0pabH8pQ/+onw3881zN4xiqxPKnK3fD4oC5S?= =?us-ascii?Q?+yEmO4LIVLObm+aTk4Dqxfss7HorYvX14/kpyRUi?= X-MS-Exchange-AntiSpam-ExternalHop-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-ExternalHop-MessageData-0: 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 X-OriginatorOrg: oracle.com X-MS-Exchange-CrossTenant-Network-Message-Id: 766c668c-668a-47b8-07a0-08ddd9c62328 X-MS-Exchange-CrossTenant-AuthSource: PH0PR10MB5777.namprd10.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 12 Aug 2025 17:31:57.4748 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 4e2c6054-71cb-48f1-bd6c-3a9705aca71b X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: 6MSpBD+TKYCmd0D3tW+ITGcuvSVz73rI3u7kBTsTkpA/6ihX7fhvQgye8IQUVcxj3YhjR0iJnP8tSm9UblIGgQ== X-MS-Exchange-Transport-CrossTenantHeadersStamped: CO1PR10MB4515 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1099,Hydra:6.1.9,FMLib:17.12.80.40 definitions=2025-08-12_07,2025-08-11_01,2025-03-28_01 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 bulkscore=0 mlxscore=0 phishscore=0 spamscore=0 suspectscore=0 mlxlogscore=999 adultscore=0 malwarescore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2507300000 definitions=main-2508120168 X-Proofpoint-Spam-Details-Enc: AW1haW4tMjUwODEyMDE2OCBTYWx0ZWRfX12d+MYH9tJns lh79++aROC9uaNKNaADaNsGw4RWqsxV81qVjJj/EcN2VQja35e6c2k1hwiGhwlIxKNUNioazjoJ MvMFF41M8wfXZI5N+gkG9mzA0v5kddmpG0jPaxwMhpX3ZKrRJV7n9+w4bD+iWqmifydr1ei+xo9 BdlMdI/pLz74QpF3Kk+bP7bBp3soGQ2sjYQgrjemBspa4v954KL7ksBOUyNaNIYvVuf+oUHr4NN EVgE/G5syg8+nZdpq3um5gbL7Hed8zVlMhELyK1pnHyMXYqrR5zxGaPT/b3xnb7Sh7AEffuoA5x R6eSw0QzhchjErYADBIg8caaBlp52oSIRiuZSiDUwIO1zhI3mvvckvFKgvp64wkoL4KE4gkCRGG 8ibnZQLg4XUF8COpQ/SpLSnZV9NsOeVPOfr/LER8J84vBJihCu0srnP7SZzZoCGqdwTEBdqB X-Authority-Analysis: v=2.4 cv=eIsTjGp1 c=1 sm=1 tr=0 ts=689b7a92 b=1 cx=c_pps a=qoll8+KPOyaMroiJ2sR5sw==:117 a=qoll8+KPOyaMroiJ2sR5sw==:17 a=6eWqkTHjU83fiwn7nKZWdM+Sl24=:19 a=z/mQ4Ysz8XfWz/Q5cLBRGdckG28=:19 a=lCpzRmAYbLLaTzLvsPZ7Mbvzbb8=:19 a=wKuvFiaSGQ0qltdbU6+NXLB8nM8=:19 a=Ol13hO9ccFRV9qXi2t6ftBPywas=:19 a=xqWC_Br6kY4A:10 a=kj9zAlcOel0A:10 a=2OwXVqhp2XgA:10 a=GoEa3M9JfhUA:10 a=yPCof4ZbAAAA:8 a=_DyhGWQx9tc7Uwkf4PgA:9 a=CjuIK1q_8ugA:10 cc=ntf awl=host:12070 X-Proofpoint-GUID: p74kbEvLkDAqxs7ukZNS2soP4_8CkPl8 X-Proofpoint-ORIG-GUID: p74kbEvLkDAqxs7ukZNS2soP4_8CkPl8 * Lorenzo Stoakes [250812 11:47]: > We now need to account for flag initialisation on fork. We retain the > existing logic as much as we can, but dub the existing flag mask legacy. > > These flags are therefore required to fit in the first 32-bits of the flags > field. > > However, further flag propagation upon fork can be implemented in mm_init() > on a per-flag basis. > > We ensure we clear the entire bitmap prior to setting it, and use > __mm_flags_get_word() and __mm_flags_set_word() to manipulate these legacy > fields efficiently. > > Signed-off-by: Lorenzo Stoakes Reviewed-by: Liam R. Howlett > --- > include/linux/mm_types.h | 13 ++++++++++--- > kernel/fork.c | 7 +++++-- > 2 files changed, 15 insertions(+), 5 deletions(-) > > diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h > index 38b3fa927997..25577ab39094 100644 > --- a/include/linux/mm_types.h > +++ b/include/linux/mm_types.h > @@ -1820,16 +1820,23 @@ enum { > #define MMF_TOPDOWN 31 /* mm searches top down by default */ > #define MMF_TOPDOWN_MASK _BITUL(MMF_TOPDOWN) > > -#define MMF_INIT_MASK (MMF_DUMPABLE_MASK | MMF_DUMP_FILTER_MASK |\ > +#define MMF_INIT_LEGACY_MASK (MMF_DUMPABLE_MASK | MMF_DUMP_FILTER_MASK |\ > MMF_DISABLE_THP_MASK | MMF_HAS_MDWE_MASK |\ > MMF_VM_MERGE_ANY_MASK | MMF_TOPDOWN_MASK) > > -static inline unsigned long mmf_init_flags(unsigned long flags) > +/* Legacy flags must fit within 32 bits. */ > +static_assert((u64)MMF_INIT_LEGACY_MASK <= (u64)UINT_MAX); > + > +/* > + * Initialise legacy flags according to masks, propagating selected flags on > + * fork. Further flag manipulation can be performed by the caller. > + */ > +static inline unsigned long mmf_init_legacy_flags(unsigned long flags) > { > if (flags & (1UL << MMF_HAS_MDWE_NO_INHERIT)) > flags &= ~((1UL << MMF_HAS_MDWE) | > (1UL << MMF_HAS_MDWE_NO_INHERIT)); > - return flags & MMF_INIT_MASK; > + return flags & MMF_INIT_LEGACY_MASK; > } > > #endif /* _LINUX_MM_TYPES_H */ > diff --git a/kernel/fork.c b/kernel/fork.c > index c4ada32598bd..b311caec6419 100644 > --- a/kernel/fork.c > +++ b/kernel/fork.c > @@ -1056,11 +1056,14 @@ static struct mm_struct *mm_init(struct mm_struct *mm, struct task_struct *p, > mm_init_uprobes_state(mm); > hugetlb_count_init(mm); > > + mm_flags_clear_all(mm); > if (current->mm) { > - mm->flags = mmf_init_flags(current->mm->flags); > + unsigned long flags = __mm_flags_get_word(current->mm); > + > + __mm_flags_set_word(mm, mmf_init_legacy_flags(flags)); > mm->def_flags = current->mm->def_flags & VM_INIT_DEF_MASK; > } else { > - mm->flags = default_dump_filter; > + __mm_flags_set_word(mm, default_dump_filter); > mm->def_flags = 0; > } > > -- > 2.50.1 >