diff --git a/tools/perf/util/mem2node.c b/tools/perf/util/mem2node.c
index 797d86a1ab09..c84f5841c7ab 100644
--- a/tools/perf/util/mem2node.c
+++ b/tools/perf/util/mem2node.c
@@ -1,5 +1,6 @@
 #include <errno.h>
 #include <inttypes.h>
+#include <asm/bug.h>
 #include <linux/bitmap.h>
 #include <linux/kernel.h>
 #include <linux/zalloc.h>
@@ -95,7 +96,7 @@ int mem2node__init(struct mem2node *map, struct perf_env *env)
 
 	/* Cut unused entries, due to merging. */
 	tmp_entries = realloc(entries, sizeof(*entries) * j);
-	if (tmp_entries)
+	if (tmp_entries || WARN_ON_ONCE(j == 0))
 		entries = tmp_entries;
 
 	for (i = 0; i < j; i++) {