On Sat, Mar 02, 2019 at 07:19:39PM +0100, Jan Stancek wrote: > static vm_fault_t do_fault(struct vm_fault *vmf) > { > struct vm_area_struct *vma = vmf->vma; > + struct mm_struct *vm_mm = READ_ONCE(vma->vm_mm); Would this not need a corresponding WRITE_ONCE() in vma_init() ?