260 int handle_userfault(struct vm_area_struct *vma, unsigned long address,  in handle_userfault()  argument
263 	struct mm_struct *mm = vma->vm_mm;  in handle_userfault()
272 	ctx = vma->vm_userfaultfd_ctx.ctx;  in handle_userfault()
430 	struct vm_area_struct *vma, *prev;  in userfaultfd_release()  local
447 	for (vma = mm->mmap; vma; vma = vma->vm_next) {  in userfaultfd_release()
449 		BUG_ON(!!vma->vm_userfaultfd_ctx.ctx ^  in userfaultfd_release()
450 		       !!(vma->vm_flags & (VM_UFFD_MISSING | VM_UFFD_WP)));  in userfaultfd_release()
451 		if (vma->vm_userfaultfd_ctx.ctx != ctx) {  in userfaultfd_release()
452 			prev = vma;  in userfaultfd_release()
455 		new_flags = vma->vm_flags & ~(VM_UFFD_MISSING | VM_UFFD_WP);  in userfaultfd_release()
456 		prev = vma_merge(mm, prev, vma->vm_start, vma->vm_end,  in userfaultfd_release()
457 				 new_flags, vma->anon_vma,  in userfaultfd_release()
458 				 vma->vm_file, vma->vm_pgoff,  in userfaultfd_release()
459 				 vma_policy(vma),  in userfaultfd_release()
462 			vma = prev;  in userfaultfd_release()
464 			prev = vma;  in userfaultfd_release()
465 		vma->vm_flags = new_flags;  in userfaultfd_release()
466 		vma->vm_userfaultfd_ctx = NULL_VM_UFFD_CTX;  in userfaultfd_release()
721 	struct vm_area_struct *vma, *prev, *cur;  in userfaultfd_register()  local
764 	vma = find_vma_prev(mm, start, &prev);  in userfaultfd_register()
767 	if (!vma)  in userfaultfd_register()
772 	if (vma->vm_start >= end)  in userfaultfd_register()
783 	for (cur = vma; cur && cur->vm_start < end; cur = cur->vm_next) {  in userfaultfd_register()
809 	if (vma->vm_start < start)  in userfaultfd_register()
810 		prev = vma;  in userfaultfd_register()
816 		BUG_ON(vma->vm_ops);  in userfaultfd_register()
817 		BUG_ON(vma->vm_userfaultfd_ctx.ctx &&  in userfaultfd_register()
818 		       vma->vm_userfaultfd_ctx.ctx != ctx);  in userfaultfd_register()
824 		if (vma->vm_userfaultfd_ctx.ctx == ctx &&  in userfaultfd_register()
825 		    (vma->vm_flags & vm_flags) == vm_flags)  in userfaultfd_register()
828 		if (vma->vm_start > start)  in userfaultfd_register()
829 			start = vma->vm_start;  in userfaultfd_register()
830 		vma_end = min(end, vma->vm_end);  in userfaultfd_register()
832 		new_flags = (vma->vm_flags & ~vm_flags) | vm_flags;  in userfaultfd_register()
834 				 vma->anon_vma, vma->vm_file, vma->vm_pgoff,  in userfaultfd_register()
835 				 vma_policy(vma),  in userfaultfd_register()
838 			vma = prev;  in userfaultfd_register()
841 		if (vma->vm_start < start) {  in userfaultfd_register()
842 			ret = split_vma(mm, vma, start, 1);  in userfaultfd_register()
846 		if (vma->vm_end > end) {  in userfaultfd_register()
847 			ret = split_vma(mm, vma, end, 0);  in userfaultfd_register()
857 		vma->vm_flags = new_flags;  in userfaultfd_register()
858 		vma->vm_userfaultfd_ctx.ctx = ctx;  in userfaultfd_register()
861 		prev = vma;  in userfaultfd_register()
862 		start = vma->vm_end;  in userfaultfd_register()
863 		vma = vma->vm_next;  in userfaultfd_register()
864 	} while (vma && vma->vm_start < end);  in userfaultfd_register()
885 	struct vm_area_struct *vma, *prev, *cur;  in userfaultfd_unregister()  local
906 	vma = find_vma_prev(mm, start, &prev);  in userfaultfd_unregister()
909 	if (!vma)  in userfaultfd_unregister()
914 	if (vma->vm_start >= end)  in userfaultfd_unregister()
926 	for (cur = vma; cur && cur->vm_start < end; cur = cur->vm_next) {  in userfaultfd_unregister()
946 	if (vma->vm_start < start)  in userfaultfd_unregister()
947 		prev = vma;  in userfaultfd_unregister()
953 		BUG_ON(vma->vm_ops);  in userfaultfd_unregister()
959 		if (!vma->vm_userfaultfd_ctx.ctx)  in userfaultfd_unregister()
962 		if (vma->vm_start > start)  in userfaultfd_unregister()
963 			start = vma->vm_start;  in userfaultfd_unregister()
964 		vma_end = min(end, vma->vm_end);  in userfaultfd_unregister()
966 		new_flags = vma->vm_flags & ~(VM_UFFD_MISSING | VM_UFFD_WP);  in userfaultfd_unregister()
968 				 vma->anon_vma, vma->vm_file, vma->vm_pgoff,  in userfaultfd_unregister()
969 				 vma_policy(vma),  in userfaultfd_unregister()
972 			vma = prev;  in userfaultfd_unregister()
975 		if (vma->vm_start < start) {  in userfaultfd_unregister()
976 			ret = split_vma(mm, vma, start, 1);  in userfaultfd_unregister()
980 		if (vma->vm_end > end) {  in userfaultfd_unregister()
981 			ret = split_vma(mm, vma, end, 0);  in userfaultfd_unregister()
991 		vma->vm_flags = new_flags;  in userfaultfd_unregister()
992 		vma->vm_userfaultfd_ctx = NULL_VM_UFFD_CTX;  in userfaultfd_unregister()
995 		prev = vma;  in userfaultfd_unregister()
996 		start = vma->vm_end;  in userfaultfd_unregister()
997 		vma = vma->vm_next;  in userfaultfd_unregister()
998 	} while (vma && vma->vm_start < end);  in userfaultfd_unregister()