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Miller" , Andreas Larsson , Arnd Bergmann , Greg Kroah-Hartman , Dan Williams , Vishal Verma , Dave Jiang , Nicolas Pitre , Muchun Song , Oscar Salvador , David Hildenbrand , Konstantin Komarov , Baoquan He , Vivek Goyal , Dave Young , Tony Luck , Reinette Chatre , Dave Martin , James Morse , Alexander Viro , Christian Brauner , Jan Kara , "Liam R . Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Hugh Dickins , Baolin Wang , Uladzislau Rezki , Dmitry Vyukov , Andrey Konovalov , Jann Horn , Pedro Falcato , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-csky@vger.kernel.org, linux-mips@vger.kernel.org, linux-s390@vger.kernel.org, sparclinux@vger.kernel.org, nvdimm@lists.linux.dev, linux-cxl@vger.kernel.org, linux-mm@kvack.org, ntfs3@lists.linux.dev, kexec@lists.infradead.org, kasan-dev@googlegroups.com Subject: Re: [PATCH v2 16/16] kcov: update kcov to use mmap_prepare Message-ID: <20250915124801.GG1024672@nvidia.com> References: <5b1ab8ef7065093884fc9af15364b48c0a02599a.1757534913.git.lorenzo.stoakes@oracle.com> <20250915121617.GD1024672@nvidia.com> <872a06d7-6b74-410c-a0fe-0a64ae1efd9b@lucifer.local> Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <872a06d7-6b74-410c-a0fe-0a64ae1efd9b@lucifer.local> X-ClientProxiedBy: YT3PR01CA0129.CANPRD01.PROD.OUTLOOK.COM (2603:10b6:b01:83::17) To PH7PR12MB5757.namprd12.prod.outlook.com (2603:10b6:510:1d0::13) Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: PH7PR12MB5757:EE_|PH0PR12MB8797:EE_ X-MS-Office365-Filtering-Correlation-Id: 47b0046c-5032-4fe6-4a90-08ddf4561c2c X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|7416014|1800799024|376014|366016; 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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?VRWn03OitKYRA/DwuaRE4Cz5hxYxke5N/q7ey/Z9o3NeiogdaYuIuN3b3w6O?= =?us-ascii?Q?vcH7/9gKtxt80vCJOGkoSa5jVEOS8npGNmbSQwAYuG4xcgDiJI/kjTeneB14?= =?us-ascii?Q?6PtduwEZ9Qjf1X7Or6XaNpDFULeXuc57I+i/Y4DLN1Eh9XqWoU/oYC6zUW6W?= =?us-ascii?Q?6zQSp8rStAtgE6J4r5VAXo+HQUJNMIh4i+W7/c5QMSOCOa1UUGa6M1Ha7w4H?= =?us-ascii?Q?nfYvEmBa9nrkUwmycN4NJv2dW7cbpRuWGaJqlYtS6GyZpl1OVfRTD4t/W3Xt?= =?us-ascii?Q?bAbuOJovwi5hqRu2b8Blj9IhdV+MuY7xaw/4zO2JQQ+ztKMRxT/OWHNL7D/6?= =?us-ascii?Q?++M02t3H0wRIEZTLIBDN1qpulzu71mRouTohx2icrvQ6uNjSzBAj5sZGRRC2?= =?us-ascii?Q?/ZrUQGfkWAh80HCOUvU4c27xV9J+Os904X9Yj1gIDOZ26ST3386hOqfLvuJn?= =?us-ascii?Q?DhlMDquwC6N95vEtk9Bo9Hd1QmgLn3VqL/R3Ydbn72fUGCaSqNQNNy48eWLQ?= =?us-ascii?Q?FJ2/zGsbWNlYDeCv14SazZOQ/tTiPgKpISD0cIa+oUvB6Ra+OJ/MJqDRdUOr?= =?us-ascii?Q?URXZwn6RjWnRdGwVYwobyr1RI6rEC+l3rcZsWljG8YEFQW5Yp+7hsNgFCtdD?= =?us-ascii?Q?mqlRZTtxPy7dt4HS5YfslZoiEh5rhJMLT7eJZVUDEcSzMbXyElIlGTFp2rCI?= =?us-ascii?Q?kLz5sRg05Gat92uRQ48Awq45oR0GTqpohqckpPODcqxSfRrw2ISO13QMJdVs?= =?us-ascii?Q?Qxke30Q9p/RCFMpVpaBnx6oecxI8TFbyoCENqlwAG80+uDkBdCnHCZe7UJN/?= =?us-ascii?Q?YBODqs8e1Kh6/jQnMZfhrRJm4IjIJjN1jGIDjEYe6EJ1EePWA1AFpD4cBGs8?= =?us-ascii?Q?v0J1vFjK2+5cvbbhEkDu1zrUGuqkEIKCw5FHXLCMnRl6gzBLMQsxUupBZQvL?= =?us-ascii?Q?EnyeIvO5Fkqkih8kIkAqk6rdhbn+/ONDy+xvIz6kZHkJlDIzNxMJ+sYr5UAs?= =?us-ascii?Q?rxcR4KMNO0CCHH/qjXfwFz3jhopelZIM2UI83JZ3N2ISbDddMJuYYpKwoU09?= =?us-ascii?Q?W5bmc6JilH2AZGPFNE9GlHGcEGpV/vAE75WE6jyxCOhN7xGeyPxMvHYWNc0l?= =?us-ascii?Q?5iwFn+7Vv01wSTcvuSG7x3vz/KFaAzDM2T6mjxfm2FTXUixrYSII/rcIDk46?= =?us-ascii?Q?G645bU1aiZzTvkyLTA/kkx0qBxsvn54HHsFzAbTSMjX+gmlrhYejhT7bV0fZ?= =?us-ascii?Q?7X53i8vx06iJUfF+DLvswGrND4tvkus/ZFfFckkRZnJy/5fuflApTbC3zZWY?= =?us-ascii?Q?6aAtj9rXUUld/CjFcMzGfYEa82cf+elD0/6MLo2/h5VeTEp37jBh6RjBxiBK?= =?us-ascii?Q?RqVCQFLLzaacsd3mTrW6ENKOukVGHSHi8P1ykTmgwVggYagRbtC/KjXCchz/?= =?us-ascii?Q?K5U612uOW1On5OVXjUoQmcqxrYnENWHRLUiLykJkcMXVzZEmW/F1adD/DPML?= =?us-ascii?Q?SqD56ktlJnUaMPm8HNZ9hvaZMYSwwr2Gk8Vki37XiDK6asijXzzyYJO9I2N4?= =?us-ascii?Q?gGONw+NzJyG8YnMPhx0=3D?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 47b0046c-5032-4fe6-4a90-08ddf4561c2c X-MS-Exchange-CrossTenant-AuthSource: PH7PR12MB5757.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 15 Sep 2025 12:48:03.5144 (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: mzogALwuNUANkerB9kJgREo0bYyzFJppK0PxFsRPgsC3FoO4zqVXsW11aSVktkt0 X-MS-Exchange-Transport-CrossTenantHeadersStamped: PH0PR12MB8797 On Mon, Sep 15, 2025 at 01:43:50PM +0100, Lorenzo Stoakes wrote: > > > + if (kcov->area == NULL || desc->pgoff != 0 || > > > + vma_desc_size(desc) != size) { > > > > IMHO these range checks should be cleaned up into a helper: > > > > /* Returns true if the VMA falls within starting_pgoff to > > starting_pgoff + ROUND_DOWN(length_bytes, PAGE_SIZE)) > > Is careful to avoid any arithmetic overflow. > > */ > > Right, but I can't refactor every driver I touch, it's not really tractable. I'd > like to get this change done before I retire :) I don't think it is a big deal, and these helpers should be part of the new api. You are reading and touching anyhow. > > If anything the action should be called mmap_action_vmalloc_user() to > > match how the memory was allocated instead of open coding something. > > Again we're getting into the same issue - my workload doesn't really permit > me to refactor every user of .mmap beyond converting sensibly to the new > scheme. If you are adding this explicit action concept then it should be a sane set of actions. Using a mixed map action to insert a vmalloc_user is not a reasonable thing to do. Jason