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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?7YF/zmWUZfBggoVh+a5mev51JX5YmVU+z2pTlwLdsbA8m6Dogeth+7Bx0KlQ?= =?us-ascii?Q?hkAGD3SgdzA3ruREUDjp8Vzn61ThKqfT6ESqDyybO1ct2B2wqZi+jMSoO/r8?= =?us-ascii?Q?lhr6zvTNDtAIU+R6WyBzs0rair4Illj+T7Gm+fV2jh4/2A0C6RjSlGiksL99?= =?us-ascii?Q?+nNVyYMDRQC1+hhGgsE29Ju3R9IGJHiPi/A0Z4VzcApDl6rws6NkbOYJvREO?= =?us-ascii?Q?JxiWCePjDGNL1DlLsWjZzlQQ23dv8D0HJ/qSimEHLijsO34EEFkXbhZ83bLQ?= =?us-ascii?Q?h1xf3+sRC5NNZau2+eGS+xBAiofcd1cdQZOKQe8qdrgTv133O7lnqQRrB755?= =?us-ascii?Q?hWhTdGXVOr/8ee0XHBYunAr97eHdcyi6f/Tb9hhF+GpA368880SbTzczrL3P?= =?us-ascii?Q?xzv0XI71XkV/ErkMqlHPTnr9t5ARoJCYqNY2/2dI/7oaMq4beqGXiKy3aE8k?= =?us-ascii?Q?XpkO9aqkIxTHkrvw5wKWiO6lsJnXBgGXMQbbPnRU/rZchfStJdQ/5PpySD/2?= =?us-ascii?Q?On09R+SA4rlCHxS+483hvKJ82cNY6Yf5iPpzuKC0Wz2nHAI+BqB3C4GkI8/u?= =?us-ascii?Q?bZT6ysdnCgmC7Oo/4bWA5psf3vyTze2UwP4/oTMT0UHaNmSd/nsDybnnbcdZ?= =?us-ascii?Q?pDvgF2L0DqFHPLGqtoCYGkT8e601tjBeHoU9+yF/npLIMA7LKcS/HTXWYg6V?= =?us-ascii?Q?acn6+a3iAOo99MtGR9PHLXIOEUFyVQ6T2Km4gMlF1Ng/RPo01XMGT1XtjItt?= =?us-ascii?Q?pEYyJYDdf+1wQ1OyqeAVnFP84HulWppf8CeKLpdPgjCb/Z19virRzj0X0nqt?= =?us-ascii?Q?NXsFm7PGrO1z5SI+cJOjgpTiRKPWNQLSXqfDbLpVe9YS4hRO/0pyY1qOHIKl?= =?us-ascii?Q?TGaA5+46Vg108xPA2043jSc/Go1T1bcESfr1kFMrGKacHH33JzuZCeenveb/?= =?us-ascii?Q?pCF1Q/fwjJ6Wa55LvVYz5exAM/hj2lOHmbHBH0TmlW/LrwhHfz0f9LEMO5L1?= =?us-ascii?Q?R8Bm+YeUJ1r8ihY+jzKrX4L1xXi0SuNWKaARVsn+JxSVgCEqhvT/YbXO72uA?= =?us-ascii?Q?+mN0bjBtSLn502vM9jrhmvxiLxzKaM5AXpCkCE4p4F2y4tCLYSBvLa7UAClF?= =?us-ascii?Q?G5wFxr7ePR1IPh+rxtV34c54M3KJ8dk4hj/RSh0NhEH3cdM3LBX+mIBgwpjp?= =?us-ascii?Q?vToxMVaCVbGbPxt4vABd49hXxqnG5ADEGf2OVuApfYS7o2X22uxvbuNXBhHo?= =?us-ascii?Q?yzwXWKV403vxU3MvvuVyR5Jv/mcCnCQKVeB+7LNohHkTF52n5GsRxhLvy35f?= =?us-ascii?Q?kBBTRh3domr7b854E+I6gxUhUFB67ovSFkhdNMbdoknaISP4coquvwfDtWV8?= =?us-ascii?Q?S4itmoMwchdGj2TFhE7gfcS2GGSeT9oQoabAxTW9m3dybn9s//982TMwqnMm?= =?us-ascii?Q?KMrTq61S7UXuNlTxMek9fg3p16TF4TwwpwoyrUU+mCBmB/JhEBpST59xbmmV?= =?us-ascii?Q?kmI9zhbZBRqKXHE/X+gD6jobZT/GizJVQiXeI7wVcosCsVJhq0kpApQtxmdy?= =?us-ascii?Q?lwE5gvbiBccBP2Rzqg7VoptwoMwHC030mQyWjSah?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: ebffe729-c8ca-47d6-6b47-08dbd3e3699e X-MS-Exchange-CrossTenant-AuthSource: LV2PR12MB5869.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 23 Oct 2023 16:16:28.9145 (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: hrv5E0GLPT5gMu8Cn9IJBxdwnteKYG1XdOq1AcHYYbBTiAv6FRX2DwiAzFG9JNJ2 X-MS-Exchange-Transport-CrossTenantHeadersStamped: MN2PR12MB4302 On Mon, Oct 23, 2023 at 04:56:01PM +0100, Joao Martins wrote: > On 23/10/2023 13:41, Arnd Bergmann wrote: > > On Mon, Oct 23, 2023, at 14:10, Jason Gunthorpe wrote: > >> On Mon, Oct 23, 2023 at 10:28:13AM +0100, Joao Martins wrote: > >>>> so it's probably > >>>> best to add a range check plus type cast, rather than an > >>>> expensive div_u64() here. > >>> > >>> OK > >> > >> Just keep it simple, we don't need to optimize for 32 bit. div_u64 > >> will make the compiler happy. > > > > Fair enough. FWIW, I tried adding just the range check to see > > if that would make the compiler turn it into a 32-bit division, > > but that didn't work. > > > > Some type of range check might still be good to have for > > unrelated reasons. > > I can reproduce the arm32 build problem and I'm applying this diff below to this > patch to fix it. It essentially moves all the checks to > iommufd_check_iova_range(), including range-check and adding div_u64. > > Additionally, perhaps should also move the iommufd_check_iova_range() invocation > via io_pagetable.c code rather than hw-pagetable code? It seems to make more > sense as there's nothing hw-pagetable specific that needs to be in here. Don't you need the IOAS though? Write it like this: int iommufd_check_iova_range(struct iommufd_ioas *ioas, struct iommu_hwpt_get_dirty_bitmap *bitmap) { size_t iommu_pgsize = ioas->iopt.iova_alignment; u64 last_iova; if (check_add_overflow(bitmap->iova, bitmap->length - 1, &last_iova)) return -EOVERFLOW; if (bitmap->iova > ULONG_MAX || last_iova > ULONG_MAX) return -EOVERFLOW; if ((bitmap->iova & (iommu_pgsize - 1)) || ((last_iova + 1) & (iommu_pgsize - 1))) return -EINVAL; return 0; } And if 0 should really be rejected then check iova == last_iova Jason