Commit 4daab713 authored by Yonghong Song's avatar Yonghong Song Committed by Alexei Starovoitov
Browse files

selftests/bpf: Add bpf_{update, delete}_map_elem in hashmap iter program 



Added bpf_{updata,delete}_map_elem to the very map element the
iter program is visiting. Due to rcu protection, the visited map
elements, although stale, should still contain correct values.
  $ ./test_progs -n 4/18
  #4/18 bpf_hash_map:OK
  #4 bpf_iter:OK
  Summary: 1/1 PASSED, 0 SKIPPED, 0 FAILED

Signed-off-by: default avatarYonghong Song <yhs@fb.com>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200902235341.2001534-1-yhs@fb.com
parent dc0988bb

tools/testing/selftests/bpf/progs/bpf_iter_bpf_hash_map.c

+15 −0
Original line number Diff line number Diff line
@@ -47,7 +47,10 @@ int dump_bpf_hash_map(struct bpf_iter__bpf_map_elem *ctx) 
	__u32 seq_num = ctx->meta->seq_num;

	struct bpf_map *map = ctx->map;

	struct key_t *key = ctx->key;

	struct key_t tmp_key;

	__u64 *val = ctx->value;

	__u64 tmp_val = 0;

	int ret;



	if (in_test_mode) {

		/* test mode is used by selftests to
@@ -61,6 +64,18 @@ int dump_bpf_hash_map(struct bpf_iter__bpf_map_elem *ctx) 
		if (key == (void *)0 || val == (void *)0)

			return 0;



		/* update the value and then delete the <key, value> pair.

		 * it should not impact the existing 'val' which is still

		 * accessible under rcu.

		 */

		__builtin_memcpy(&tmp_key, key, sizeof(struct key_t));

		ret = bpf_map_update_elem(&hashmap1, &tmp_key, &tmp_val, 0);

		if (ret)

			return 0;

		ret = bpf_map_delete_elem(&hashmap1, &tmp_key);

		if (ret)

			return 0;



		key_sum_a += key->a;

		key_sum_b += key->b;

		key_sum_c += key->c;