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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?I7c5t6ofWGgyvP7hAbUsh7Hwkg7aYcPgCA4u2xssiHZFrtDjIhgsJyAQ6Kyx?= =?us-ascii?Q?XZq/LVk2b7ysQXqqWhzv56CNwl+m+7RBc+XRVPUcfOy7UdbYKnHtr5TnC2XY?= =?us-ascii?Q?X1lGl4Yj+0nGAGoBE+bkF4zDAojdvtuO60tydh20x6ggLPMpNqnGHt4Su5bD?= =?us-ascii?Q?fFEDdqH8M0tL/C18GuNislOP/gwsQFGy4/O/KRVe1qrje6XrH7WhamabupMN?= =?us-ascii?Q?OALUL+jbggIs4dyIBA57w4UduDo4QOLiW35razILfhAFiVhkS6h9+Liq7saW?= =?us-ascii?Q?mBvyIwiVa+0G8MwQEF+IFqFOF8UZtrRRTLTgiFE49xnzfNjqUlz0tFC91FHE?= =?us-ascii?Q?tFSHA5rPZuWRGLOgtiZCIR7rVX/dk2H9Ntnx0TcxZV28Unx3nuDMSn9kbVbM?= =?us-ascii?Q?eV8sn7LKeP0VptsCt1uNmJ2LS5+DjWF/G02TcluEL1WJIfvpeJVRnGL4lpAg?= =?us-ascii?Q?pWBAm/exjkGcA807aqRcQ97gdppcrvYNhwVWgBuGHSG6vKCnUjt2lOItxmUr?= =?us-ascii?Q?jLhdNYlTsa0F8pwAo2OB20nIg2c93hRcJp5nBtjFbol+VRKt1Ly2jsXfp8qo?= =?us-ascii?Q?j7ehPaScBmCB48olHnFU4bJDqOzwDlI2XdFysl/1jucglSord9aLQDiGvuyz?= =?us-ascii?Q?2zpgvcNi7YROqK4+dgGbXRTfnFpPwzA5/6zMb4LzNumzjqAFYgPIq6CN7ZU2?= =?us-ascii?Q?q3iqKArecedcfAOm7uKYYxELBc/pfL6j7s+gDqAwdiEY2FNnz9OlBNvylCol?= =?us-ascii?Q?7fX9dHHHey/MXe/TEZhFKR8uu1e4vX0s18TN7mbSoskrae3d84YuOAaBcYfa?= =?us-ascii?Q?usE7Xx7nw4u00JfaMYET5fmVczxcTg+OzE14K1dFvU87rRIM6ojiJNeYe2ut?= =?us-ascii?Q?VG+G+vgN4BqYCUlibie/b2fdhm2qm5ihSaK4gEReIdxhuProjDYaF/M08Qv7?= =?us-ascii?Q?1wI+gRZw5ebfwqArXSHmUbiVvwTY8MrIEGba4UBzSYlddtSu2Ycelck16Wv8?= =?us-ascii?Q?KUMbt412FfRtQV126N+2nM5kS2wf6l+OII9i9wrPjb3IhOQUXNwdjpnC5ZyP?= =?us-ascii?Q?7rEDn9Vri9rkpqDXjzUOItkKZTBeWurHESlYzu1QTGY/9Z0i7IYcpsTTs9LA?= =?us-ascii?Q?Y/kCsNB70qcNr4PfvWmq76fsQpnBlueFY5gfNlEjfkmX9y+o7U6nXiq1MNxE?= =?us-ascii?Q?I39iFzwbAuitGGc0xlSHUh7QYOfEbXXLqScjxEvAEIyNXjH9g6/AwxHnoULt?= =?us-ascii?Q?o/5VPLwidRJ+aXs1OY6kwWTVYaKgAx+5LgHhrq6h/KFlfRC2MtbTZIp4paXn?= =?us-ascii?Q?rkmnOIf1SG6H1FvFp+FQYfuUClKKIbnJ/znduMqlPYSw9ZJMoR5+ODCXHNN9?= =?us-ascii?Q?jn31jxxUGsdjViySL/vlkCMjX3sBVKYhJ3U+cGPRMMGlTXaQ9EbsfHlqPk3s?= =?us-ascii?Q?njAjAW/Bty+RcOuTSvdxc7/ewal/uzT4wHBmWlUfN9dvBi6ICCVRcwgIvypN?= =?us-ascii?Q?ySj+TvnUdP3cJLphIYLL0msTzGSyU7J91GZShfKY153P6/UbaHSsZLoaGEdF?= =?us-ascii?Q?2OuYFa7d45QxZpscqdc2nkbd+dkyqiZLFJ8NP8v9?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 5ace775b-73b4-45ad-32d5-08db2baa8c18 X-MS-Exchange-CrossTenant-AuthSource: LV2PR12MB5869.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 23 Mar 2023 14:26:09.9606 (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: mjmQJnLZxlEnErGH2t+NZLcsSsYkPsBUxaTb7kpH0xkHiEVW7xh5kp5OpKg/UhEL X-MS-Exchange-Transport-CrossTenantHeadersStamped: PH7PR12MB6787 Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org On Thu, Mar 23, 2023 at 07:25:55AM +0000, Tian, Kevin wrote: > > From: Jason Gunthorpe > > Sent: Wednesday, March 22, 2023 3:15 AM > > +int iommufd_device_attach(struct iommufd_device *idev, u32 *pt_id) > > +{ > > + int rc; > > + > > + rc = iommufd_device_change_pt(idev, pt_id, > > &iommufd_device_do_attach); > > + if (rc) > > + return rc; > > + > > + /* > > + * Pairs with iommufd_device_detach() - catches caller bugs > > attempting > > + * to destroy a device with an attachment. > > + */ > > + refcount_inc(&idev->obj.users); > > + return 0; > > While it's the right thing to do I'm not sure what "catch caller bugs" > mean here. There is no WARN_ON to catch. The WARN_ON is on the destroy path of the device was_destroyed = iommufd_object_destroy_user(idev->ictx, &idev->obj); WARN_ON(!was_destroyed); It is the idev we are incr'ing Jason