From: Hugh Dickins <hughd@xxxxxxxxxx> When the address is backed by a memfd, the code to split the page does nothing more than remove the PMD from the page tables. So immediately install a PTE to ensure that any other pages in that 2MB region are brought back as in 4K pages. Signed-off-by: Hugh Dickins <hughd@xxxxxxxxxx> Cc: Hugh Dickins <hughd@xxxxxxxxxx> Signed-off-by: Ashish Kalra <ashish.kalra@xxxxxxx> Signed-off-by: Michael Roth <michael.roth@xxxxxxx> --- mm/memory.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/mm/memory.c b/mm/memory.c index e68da7e403c6..33c9020ba1f8 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -4999,6 +4999,11 @@ static vm_fault_t handle_pte_fault(struct vm_fault *vmf) static int handle_split_page_fault(struct vm_fault *vmf) { __split_huge_pmd(vmf->vma, vmf->pmd, vmf->address, false, NULL); + /* + * Install a PTE immediately to ensure that any other pages in + * this 2MB region are brought back in as 4K pages. + */ + __pte_alloc(vmf->vma->vm_mm, vmf->pmd); return 0; } -- 2.25.1