selftests/bpf: Fix test_progs's parsing of test numbers

When specifying disjoint set of tests, test_progs doesn't set skipped test's
array elements to false. This leads to spurious execution of tests that should
have been skipped. Fix it by explicitly initializing them to false.

Fixes: 3a516a0a ("selftests/bpf: add sub-tests support for test_progs")
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20200314013932.4035712-2-andriin@fb.com

tools/testing/selftests/bpf/test_progs.c

@@ -424,7 +424,7 @@ static int parse_str_list(const char *s, struct str_set *set)
 
 int parse_num_list(const char *s, struct test_selector *sel)
 {
-	int i, set_len = 0, num, start = 0, end = -1;
+	int i, set_len = 0, new_len, num, start = 0, end = -1;
 	bool *set = NULL, *tmp, parsing_end = false;
 	char *next;
 
@@ -459,20 +459,21 @@ int parse_num_list(const char *s, struct test_selector *sel)
 			return -EINVAL;
 
 		if (end + 1 > set_len) {
-			set_len = end + 1;
-			tmp = realloc(set, set_len);
+			new_len = end + 1;
+			tmp = realloc(set, new_len);
 			if (!tmp) {
 				free(set);
 				return -ENOMEM;
 			}
+			for (i = set_len; i < start; i++)
+				tmp[i] = false;
 			set = tmp;
+			set_len = new_len;
 		}
-		for (i = start; i <= end; i++) {
+		for (i = start; i <= end; i++)
 			set[i] = true;
 	}
 
-	}
-
 	if (!set)
 		return -EINVAL;