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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?ROP2UiVY3xmut9R/33kPekVbx4s3fz9/rCoyQT+ITgV6Etk+iuRuIFax+rYM?= =?us-ascii?Q?WYxPCJWi0VN36MHmF+/tcIGYzE7rM0ERjA7AUjF7GYGLEkF1EMaUgz7lMAcB?= =?us-ascii?Q?GpDUzBozgRY5cpoazoLIZ9coXmpq68tMnSxgg05n8i7tMLW+4ncOEz5g8np6?= =?us-ascii?Q?BuMkB50/tN61JjWHOPZsEnJr/zGMTxb92gW2tJ+ie96kZy0sy+R6t3nML8IF?= =?us-ascii?Q?RfgokRTXNNKqRd4hUnZFcPTEMhQ70mtHOq8aFSq3zdkf4mO9bj+zK2AQeNAU?= =?us-ascii?Q?WAy3q1XWXOCRkj+6GdIOUyMr3klXOJwfXKq/1JUgNLRp8oLphvmYqJ6XnloA?= =?us-ascii?Q?gc/jr+7rnN3+NTb8YbwdXcidvJjn5CEjJiofe9zhlxbiUmz9Kq/Lvuida3Bm?= =?us-ascii?Q?g0KncxiCsvzOCpq/+qIVPDbvF8oYzthYdXKqe+Agie+oT2MOMr9lDOAGgeih?= =?us-ascii?Q?MK8vaSAT/7JsWAoLwah9YafDSF8HYjHsVVBxE6pPLYdbYtq5xBMaRcK/0iw5?= =?us-ascii?Q?mcVBYLexPDbtIxTEQoySYZx9LiibGK86IdJWlbLna+wJVfKPnpJgDkUCDNQ1?= =?us-ascii?Q?iL4/AxvBkViQIL8YIlHIy3SW5QqK8219L63unChiw477b4/Ath8MnmDcBzna?= =?us-ascii?Q?jhCpLWbtAIN9/xI8rulbU4alTAh3B3HE5GIo36nr7kUrr0Rfjr1Kl4jfTE1j?= =?us-ascii?Q?nqS+YsDu3uhydggBELcm4ijJnnaxANuPrXhW93lOeGdm1AyU9bulMeYrotB6?= =?us-ascii?Q?8HqOURE6KMswerInMeywZlejxCwkCOqdZwTMWg29o9ZfOZpz2XBoojsK5pcw?= =?us-ascii?Q?0l7TFIFru9ebdhVZuauhKrZfV+fUFvdvZKYLnhtk+RqS9lDcnmEz3SvVHKa/?= =?us-ascii?Q?YROwgizgXlg6gGGKHHkbsV/NzHFj2iOzMFqWBL1W6SNiUDZE2ToesXG0uz6S?= =?us-ascii?Q?9KTPCR4o4N/hMVMPC8cLfu+iTvvzo1sBAeizXOHmUqlJYifuL/pe5NRz1peo?= =?us-ascii?Q?9mcb4qE0cLTVb3YizSJ+ZOlpEhFf8Fh0xaNMsk25vy7c6bSnJGM0ajxPZkZD?= =?us-ascii?Q?LN4AWMfK+Rtwx9/onFr1xOOSzOrqYn8dzDrE4mM3UC+DTdpMlsA9vpOxDUSX?= =?us-ascii?Q?BuzrsAwR0ai/5CA4wBYei0RtfOXU0YzE4/DAl0gQwvFhnzIJICdxLbg00zI5?= =?us-ascii?Q?DVHDRGUWPHqxZQphGhJ37DLuipn59rWNEPuhzsAm30IhfhGTti1ADMYAJuZT?= =?us-ascii?Q?p5z6erXnEz5fPJaVWKH6BvSFzZmww6pST+rSVLrIy0B1DRyle/TGDth9Etjx?= =?us-ascii?Q?jE4N66RZoPDoeHa+b10hTzSZLkr9hZI1XBU5IGtp5+/HoPXBFQnw/x6ONxCz?= =?us-ascii?Q?9LY3WVKPieFtEusW5bNDGGFLLvvjuXujC1I6185INWuSOIZLjXW49OdSQQDh?= =?us-ascii?Q?A7nj1w+hwrqRnmu3WxMwgABq1lPlrhq2YM+eVuCpZUhWnAXGtMaFqAnH/+QJ?= =?us-ascii?Q?m1Hw7FNmww5NCra4F+dhqPkyw5UBEmScCAQzrG/M9ZFPDTeZn9XXB+SuX5Di?= =?us-ascii?Q?mDr9itzel0OFSwB46kiz2DKLJqFrV96oZF8iOLiVjUfzWdzBEli/rawOUJU0?= =?us-ascii?Q?eml1Hp+huIqxKO6M10jc2zEJ8KIB8o1rBOx51dSDNHqquf4yedolGj78UCjL?= =?us-ascii?Q?mt3dZf9po45U/HA+JIO3GbflNFdgwM2rd0TGb+ZPU89fmBpv?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 1a681c54-01f2-4a11-0c26-08dedc7f547a X-MS-Exchange-CrossTenant-AuthSource: BL0PR12MB4995.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 07 Jul 2026 23:27:37.3727 (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: ozbI0+93SUyupwt+yWgsAvjeJFFE2Xp+2fl6R4lCPN4RMlET2aSjYz/k7PAGbZm502+GekDs7oY2s4gscNNAow== X-MS-Exchange-Transport-CrossTenantHeadersStamped: SJ2PR12MB8740 On Tue, Jul 07, 2026 at 06:45:08AM -0700, Usama Arif wrote: > madvise_cold_or_pageout_pte_range() takes pmd_trans_huge_lock(), whose > pmd_is_huge() check returns true for a device-private PMD. The subsequent > !pmd_present() branch has a VM_BUG_ON() asserting migration is the only > allowed non-present case; a device-private PMD trips it. > > Potential trigger: an HMM-based GPU driver races with > madvise(MADV_COLD)/MADV_PAGEOUT: pmd_trans_huge(*pmd) reads true, then > migrate_vma_pages() flips the PMD to a device-private entry before the > PMD lock is acquired. > > Skip device-private PMDs after taking the lock, before the !pmd_present() > check. > > Reported-by: sashiko-bot > Link: https://sashiko.dev/#/patchset/20260703173903.3789516-1-usama.arif%40linux.dev?part=6 > Fixes: 368076f52ebe ("mm/huge_memory: add device-private THP support to PMD operations") > Signed-off-by: Usama Arif > --- > mm/madvise.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/mm/madvise.c b/mm/madvise.c > index 9292f60b19aa..870be398c6f3 100644 > --- a/mm/madvise.c > +++ b/mm/madvise.c > @@ -384,6 +384,9 @@ static int madvise_cold_or_pageout_pte_range(pmd_t *pmd, > return 0; > > orig_pmd = *pmd; > + if (pmd_is_device_private_entry(orig_pmd)) > + goto huge_unlock; > + > if (is_huge_zero_pmd(orig_pmd)) > goto huge_unlock; > > Reviewed-by: Balbir Singh