Re: [PATCH bpf-next v4 6/6] bpf: Test bpf_sk_storage_get in tcp iterators

[Martin KaFai Lau]

On Wed, Dec 02, 2020 at 09:55:27PM +0100, Florent Revest wrote:
> This extends the existing bpf_sk_storage_get test where a socket is
> created and tagged with its creator's pid by a task_file iterator.
> 
> A TCP iterator is now also used at the end of the test to negate the
> values already stored in the local storage. The test therefore expects
> -getpid() to be stored in the local storage.
> 
> Signed-off-by: Florent Revest <revest@xxxxxxxxxx>
> Acked-by: Yonghong Song <yhs@xxxxxx>
> ---
>  .../selftests/bpf/prog_tests/bpf_iter.c        | 13 +++++++++++++
>  .../progs/bpf_iter_bpf_sk_storage_helpers.c    | 18 ++++++++++++++++++
>  2 files changed, 31 insertions(+)
> 
> diff --git a/tools/testing/selftests/bpf/prog_tests/bpf_iter.c b/tools/testing/selftests/bpf/prog_tests/bpf_iter.c
> index 9336d0f18331..b8362147c9e3 100644
> --- a/tools/testing/selftests/bpf/prog_tests/bpf_iter.c
> +++ b/tools/testing/selftests/bpf/prog_tests/bpf_iter.c
> @@ -978,6 +978,8 @@ static void test_bpf_sk_storage_delete(void)
>  /* This creates a socket and its local storage. It then runs a task_iter BPF
>   * program that replaces the existing socket local storage with the tgid of the
>   * only task owning a file descriptor to this socket, this process, prog_tests.
> + * It then runs a tcp socket iterator that negates the value in the existing
> + * socket local storage, the test verifies that the resulting value is -pid.
>   */
>  static void test_bpf_sk_storage_get(void)
>  {
> @@ -994,6 +996,10 @@ static void test_bpf_sk_storage_get(void)
>  	if (CHECK(sock_fd < 0, "socket", "errno: %d\n", errno))
>  		goto out;
>  
> +	err = listen(sock_fd, 1);
> +	if (CHECK(err != 0, "listen", "errno: %d\n", errno))
> +		goto out;

		goto close_socket;

> +
>  	map_fd = bpf_map__fd(skel->maps.sk_stg_map);
>  
>  	err = bpf_map_update_elem(map_fd, &sock_fd, &val, BPF_NOEXIST);
> @@ -1007,6 +1013,13 @@ static void test_bpf_sk_storage_get(void)
>  	      "map value wasn't set correctly (expected %d, got %d, err=%d)\n",
>  	      getpid(), val, err);
The failure of this CHECK here should "goto close_socket;" now.

Others LGTM.

Acked-by: Martin KaFai Lau <kafai@xxxxxx>

>  
> +	do_dummy_read(skel->progs.negate_socket_local_storage);
> +
> +	err = bpf_map_lookup_elem(map_fd, &sock_fd, &val);
> +	CHECK(err || val != -getpid(), "bpf_map_lookup_elem",
> +	      "map value wasn't set correctly (expected %d, got %d, err=%d)\n",
> +	      -getpid(), val, err);
> +
>  close_socket:
>  	close(sock_fd);
>  out: