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Tsirkin" , Niklas Schnelle , Shameerali Kolothum Thodi , Yi Liu , Keqian Zhu Subject: Re: [PATCH v4 16/17] iommufd: Add some fault injection points Message-ID: References: <0-v4-0de2f6c78ed0+9d1-iommufd_jgg@nvidia.com> <16-v4-0de2f6c78ed0+9d1-iommufd_jgg@nvidia.com> Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-ClientProxiedBy: BL0PR1501CA0004.namprd15.prod.outlook.com (2603:10b6:207:17::17) To LV2PR12MB5869.namprd12.prod.outlook.com (2603:10b6:408:176::16) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: LV2PR12MB5869:EE_|PH7PR12MB6665:EE_ X-MS-Office365-Filtering-Correlation-Id: fed8e5bd-aade-43b7-1d26-08dac185fbfe X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0; X-Microsoft-Antispam-Message-Info: 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 X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:LV2PR12MB5869.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230022)(4636009)(136003)(39860400002)(346002)(396003)(376002)(366004)(451199015)(83380400001)(2906002)(66946007)(36756003)(66556008)(4326008)(8676002)(66476007)(41300700001)(86362001)(316002)(54906003)(6636002)(37006003)(38100700002)(6862004)(2616005)(6512007)(7406005)(7416002)(5660300002)(8936002)(26005)(4744005)(186003)(6506007)(6486002)(478600001);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?/DTF7+0+qUlseOE2+cmzYpXa+c0XGAvyX4uH+VfYMBr0IKkTCtIFFYmC0Xu8?= =?us-ascii?Q?zXvMGCaWh1ZBHsayzoK/P7V+K7V1ulmt6qIp68XpUzKY0+7rZCnJhzkLSBux?= =?us-ascii?Q?VGLcrLpW/AWRhE9Z8iX7lso5o3MtV7bwKLSVle7WE9eLW42GU/Y12Am9lAlH?= =?us-ascii?Q?VDLS8lcmbnQQhakIeM2ur/dROzbXN33ODv8tUGDRba4PT17C4aQj5nDsJetJ?= =?us-ascii?Q?LtsCjBJ0oqqXcIKOAfO0nLZvEa5gmCFkNQQ2KRAQC17ckJrZInDGqIqwi9NJ?= =?us-ascii?Q?YgxXjEuggrT5xYQeBDaOX/TX5b1Y8Um4F0jJyhgNWB1ckcD0Sffh4vlV6MLV?= =?us-ascii?Q?Fr47iUvSBuBFA+W1Mw1R+2CNe3eNSnH35Jce18cmhaiPkkYqzFNPxH8yp54g?= =?us-ascii?Q?ZknbFX8XyEDIB7M04kxkZMEpIvPZhd+zrJzhB7yxHsKONjf3tJMLUeZhmHUs?= =?us-ascii?Q?O/ByocuO38d8GwXz4VinR10gE5BjSj4T9NPNyEp6nzrgDx8mWw4nyPTb05M/?= =?us-ascii?Q?lVch4IbWJ/52kKSbNXAToK4P0KDxzgC/cvCIn3If8Aoqro3cb9ueFlZp07kl?= =?us-ascii?Q?e9KBf8gaBMD8KEkYVvEftISoATOOU8ff/t6c1fC0fDUgRT8sadvNMss7bvgU?= =?us-ascii?Q?Vr6AB+wCYY5hzLPXPCe4ZflZ/bUxtn/MwtVmO6911fphi6W9Ra9t876vaE0l?= =?us-ascii?Q?L/K7RZHDxcE8V/AvZT/cImiupkiDkwf/Cs3zsAcoif+mEj8PF23J9rqdiEAq?= =?us-ascii?Q?EyLuZlOQtx05mEB2TtjGVrsP9lLTNBk67QCWB8CNhTCTWkJS5Z2WUWxA2ctY?= =?us-ascii?Q?MoW1vv2x/ynnWos/CuEzXqYpA+80F+iTnHS7LfnLbVou3EEew6Ypk10b23l+?= =?us-ascii?Q?G0/cfxnZhnu4hNjNK7g2KQeFgszoc7TQVZF1d8T9OJnwoPWpu5acd8ZncPDr?= =?us-ascii?Q?O1SMYViL20flXbysSO8ecLPihy/6bZxdWy3oUZQf95znMej3tEJegzlwRlaD?= =?us-ascii?Q?TSeudfC7sWJYTxzWohgRdAbS+9my50fIMM4qCvxNShzhJAvjmljKyf5GiRc8?= =?us-ascii?Q?uV55L32cadrDozqTpofdvnhk7KeFIAbc41bDecpxjyRJDcIV1tJvZD2U2qkD?= =?us-ascii?Q?DjlhbUsVR+sNWsR9NvtSv9IMSfKtCOKKMDHXkXVjD8rIZXOoFsVsz/UTDHJQ?= =?us-ascii?Q?oOGQEtE6IHptZC6oaOpNU9qRiqdezPtrwsZyfC3rQZRVjsZiDyKWdv5+a9Py?= =?us-ascii?Q?Zq79k/kHhlQG7P3XLYJxtZ8s+uLxzMx5+BOlCdFzulSkkyszuk8PBlt0hkWo?= =?us-ascii?Q?he6KdtKiCigaBWiDjkeEQfVTzi86MsU0ap6pMPpUNkJXaAf6+pQJ7UU6Vsgw?= =?us-ascii?Q?sadgkqK90CJfe1eo3Qk/sc9cWpcpzovv3C9PfNJenEDiYxepG8wMqmwnYeLm?= =?us-ascii?Q?AHEVKIRavPuhnJ1VazNAJ8i7I38LGzhP95BVe98bIziON5Syap5MctUAZIO1?= =?us-ascii?Q?v1ZW/xxwo3FbHcpl8gv8dm9x+LmFU00rrw6FxJbPXEx35dMX6lMi4mQ+nyPr?= =?us-ascii?Q?RCf1giB0QxArF2Ix5yw=3D?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: fed8e5bd-aade-43b7-1d26-08dac185fbfe X-MS-Exchange-CrossTenant-AuthSource: LV2PR12MB5869.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 08 Nov 2022 12:37:23.0767 (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: ZB8O39n4oZErTpMQNFniXRPTnetQmaiOiRvfa39aG0vKa9pws4rph61+xumsMyFD X-MS-Exchange-Transport-CrossTenantHeadersStamped: PH7PR12MB6665 Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org On Mon, Nov 07, 2022 at 11:25:26PM -0800, Nicolin Chen wrote: > On Mon, Nov 07, 2022 at 08:49:09PM -0400, Jason Gunthorpe wrote: > > > diff --git a/drivers/iommu/iommufd/main.c b/drivers/iommu/iommufd/main.c > > > @@ -489,6 +494,15 @@ static int pages_to_xarray(struct xarray *xa, unsigned long start_index, > > > > xas_lock(&xas); > > while (pages != end_pages) { > > + /* xarray does not participate in fault injection */ > > + if (pages == half_pages && iommufd_should_fail()) { > > + xas_set_err(&xas, -EINVAL); > > + xas_unlock(&xas); > > + /* aka xas_destroy() */ > > + xas_nomem(&xas, GFP_KERNEL); > > + goto err_clear; > > Coverity reports an "unchecked return value" at xas_nomem()... > > > +err_clear: > > if (xas_error(&xas)) { > > ...yet, I think we should be fine since we do xas_error here? Yes, in this flow xas_nomem() always returns false and there is no reason to check it. Just Coverity noise Jason