Re: [PATCH bpf-next 2/2] bpf: Add a selftest for the tracing bpf_get_socket_cookie

[Yonghong Song]

On 11/26/20 9:02 AM, Florent Revest wrote:
> This builds up on the existing socket cookie test which checks whether
> the bpf_get_socket_cookie helpers provide the same value in
> cgroup/connect6 and sockops programs for a socket created by the
> userspace part of the test.
>
> Adding a tracing program to the existing objects requires a different
> attachment strategy and different headers.
>
> Signed-off-by: Florent Revest <revest@xxxxxxxxxx>
> ---
>   .../selftests/bpf/progs/socket_cookie_prog.c  | 41 ++++++++++++++++---
>   .../selftests/bpf/test_socket_cookie.c        | 18 +++++---

Do you think it is possible to migrate test_socket_cookie.c to
selftests/bpf/prog_tests so it can be part of test_progs so
it will be regularly exercised?

>   2 files changed, 49 insertions(+), 10 deletions(-)
>
> diff --git a/tools/testing/selftests/bpf/progs/socket_cookie_prog.c b/tools/testing/selftests/bpf/progs/socket_cookie_prog.c
> index 0cb5656a22b0..a11026aeaaf1 100644
> --- a/tools/testing/selftests/bpf/progs/socket_cookie_prog.c
> +++ b/tools/testing/selftests/bpf/progs/socket_cookie_prog.c
> @@ -1,11 +1,13 @@
>   // SPDX-License-Identifier: GPL-2.0
>   // Copyright (c) 2018 Facebook
>   
[...]
> diff --git a/tools/testing/selftests/bpf/test_socket_cookie.c b/tools/testing/selftests/bpf/test_socket_cookie.c
> index ca7ca87e91aa..0d955c65a4f8 100644
> --- a/tools/testing/selftests/bpf/test_socket_cookie.c
> +++ b/tools/testing/selftests/bpf/test_socket_cookie.c
> @@ -133,6 +133,7 @@ static int run_test(int cgfd)
>   	struct bpf_prog_load_attr attr;
>   	struct bpf_program *prog;
>   	struct bpf_object *pobj;
> +	struct bpf_link *link;
>   	const char *prog_name;
>   	int server_fd = -1;
>   	int client_fd = -1;
> @@ -153,11 +154,18 @@ static int run_test(int cgfd)
>   	bpf_object__for_each_program(prog, pobj) {
>   		prog_name = bpf_program__section_name(prog);
>   
> -		if (libbpf_attach_type_by_name(prog_name, &attach_type))
> -			goto err;
> -
> -		err = bpf_prog_attach(bpf_program__fd(prog), cgfd, attach_type,
> -				      BPF_F_ALLOW_OVERRIDE);
> +		if (bpf_program__is_tracing(prog)) {
> +			link = bpf_program__attach(prog);
> +			err = !link;
> +			continue;
> +		} else {
> +			if (libbpf_attach_type_by_name(prog_name, &attach_type))
> +				goto err;
> +
> +			err = bpf_prog_attach(bpf_program__fd(prog), cgfd,
> +					      attach_type,
> +					      BPF_F_ALLOW_OVERRIDE);
> +		}
>   		if (err) {
>   			log_err("Failed to attach prog %s", prog_name);
>   			goto out;