mm: Make mem_dump_obj() handle NULL and zero-sized pointers

This commit makes mem_dump_obj() call out NULL and zero-sized pointers specially instead of classifying them as non-paged memory. Cc: Christoph Lameter <[email protected]> Cc: Pekka Enberg <[email protected]> Cc: David Rientjes <[email protected]> Cc: Joonsoo Kim <[email protected]> Cc: Andrew Morton <[email protected]> Cc: <[email protected]> Reported-by: Andrii Nakryiko <[email protected]> Acked-by: Vlastimil Babka <[email protected]> Tested-by: Naresh Kamboju <[email protected]> Signed-off-by: Paul E. McKenney <[email protected]>
tobetter · Jan 22, 2021 · b70fa3b · b70fa3b
1 parent 8e7f37f
commit b70fa3b
Showing 1 changed file with 6 additions and 1 deletion.
diff --git a/mm/util.c b/mm/util.c
@@ -997,7 +997,12 @@ int __weak memcmp_pages(struct page *page1, struct page *page2)
 void mem_dump_obj(void *object)
 {
 	if (!virt_addr_valid(object)) {
-		pr_cont(" non-paged (local) memory.\n");
+		if (object == NULL)
+			pr_cont(" NULL pointer.\n");
+		else if (object == ZERO_SIZE_PTR)
+			pr_cont(" zero-size pointer.\n");
+		else
+			pr_cont(" non-paged (local) memory.\n");
 		return;
 	}
 	if (kmem_valid_obj(object)) {