Changing PTEs and PMDs to pte_numa & pmd_numa is done with the mmap_sem held for reading, which means a pmd can be instantiated and/or turned into a numa one while __handle_mm_fault is examining the value of orig_pmd. If that happens, __handle_mm_fault should just return and let the page fault retry, instead of throwing an oops. Signed-off-by: Rik van Riel <riel@xxxxxxxxxx> Reported-by: Sunil Pandey <sunil.k.pandey@xxxxxxxxx> --- mm/memory.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/mm/memory.c b/mm/memory.c index d0f0bef..9edccb2 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -3900,8 +3900,9 @@ static int __handle_mm_fault(struct mm_struct *mm, struct vm_area_struct *vma, } } - /* THP should already have been handled */ - BUG_ON(pmd_numa(*pmd)); + /* The PMD became NUMA while we examined orig_pmd. Return & retry */ + if (pmd_numa(*pmd)) + return 0; /* * Use __pte_alloc instead of pte_alloc_map, because we can't -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>