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 <rev...@google.com>
---
  .../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;