+ /*
+ * Easily overlooked: when mprotect shifts the boundary,
+ * make sure the expanding vma has anon_vma set if the
+ * shrinking vma had, to cover any anon pages imported.
+ */
+ if (importer && !importer->anon_vma) {
+ importer->anon_vma = anon_vma;
+ __anon_vma_link(importer);
+ }
+ }