diff --git a/tools/testing/selftests/mm/map_populate.c b/tools/testing/selftests/mm/map_populate.c
index 5c8a53869b1b..433e54fb634f 100644
--- a/tools/testing/selftests/mm/map_populate.c
+++ b/tools/testing/selftests/mm/map_populate.c
@@ -87,6 +87,13 @@ int main(int argc, char **argv)
 	BUG_ON(!ftmp, "tmpfile()");
 
 	ret = ftruncate(fileno(ftmp), MMAP_SZ);
+	if (ret < 0 && errno == ENOENT) {
+		/*
+		 * This probably means tmpfile() made a file on a filesystem
+		 * that doesn't handle temporary files the way we want.
+		 */
+		ksft_exit_skip("ftruncate(fileno(tmpfile())) gave ENOENT, weird filesystem?\n");
+	}
 	BUG_ON(ret, "ftruncate()");
 
 	smap = mmap(0, MMAP_SZ, PROT_READ | PROT_WRITE,