On Mon, 2025-08-11 at 12:59 -0700, Kumar Kartikeya Dwivedi wrote:
[...]
> +static void test_cgrp_from_id_ns(void)
> +{
> + LIBBPF_OPTS(bpf_test_run_opts, opts);
> + struct cgrp_kfunc_success *skel;
> + struct bpf_program *prog;
> + int fd, pid, pipe_fd[2];
> +
> + skel = open_load_cgrp_kfunc_skel();
> + if (!ASSERT_OK_PTR(skel, "open_load_skel"))
> + return;
> +
> + if (!ASSERT_OK(skel->bss->err, "pre_mkdir_err"))
> + goto cleanup;
> +
> + prog = bpf_object__find_program_by_name(skel->obj, "test_cgrp_from_id_ns");
Nit: skel->test_cgrp_from_id_ns ?
> + if (!ASSERT_OK_PTR(prog, "bpf_object__find_program_by_name"))
> + goto cleanup;
> +
> + if (!ASSERT_OK(pipe(pipe_fd), "pipe"))
> + goto cleanup;
> +
> + pid = fork();
> + if (!ASSERT_GE(pid, 0, "fork result"))
> + goto pipe_cleanup;
> +
> + if (pid == 0) {
> + int ret = 1;
> +
> + close(pipe_fd[0]);
> + fd = create_and_get_cgroup("cgrp_from_id_ns");
> + if (!ASSERT_GE(fd, 0, "cgrp_fd"))
> + _exit(1);
> +
> + if (!ASSERT_OK(join_cgroup("cgrp_from_id_ns"), "join cgrp"))
> + goto fail;
> +
> + if (!ASSERT_OK(unshare(CLONE_NEWCGROUP), "unshare cgns"))
> + goto fail;
> +
> + ret = bpf_prog_test_run_opts(bpf_program__fd(prog), &opts);
> + if (!ASSERT_OK(ret, "test run ret"))
> + goto fail;
> +
> + remove_cgroup("cgrp_from_id_ns");
If this test is executed in -vvv mode, the following is printed:
(cgroup_helpers.c:412: errno: Device or resource busy) rmdiring cgroup cgrp_from_id_ns ...
And cgroup is still in place after exit. As far as I understand,
child process needs to change cgroup again or remove_cgroup needs to
be called in the parent process.
> +
> + if (!ASSERT_OK(opts.retval, "test run retval"))
> + _exit(1);
Nit: why not 'exit'? '_exit' does not flush file descriptors.
> + ret = 0;
> + close(fd);
> + if (!ASSERT_EQ(write(pipe_fd[1], &ret, sizeof(ret)), sizeof(ret), "write pipe"))
> + _exit(1);
> +
> + _exit(0);
> +fail:
> + remove_cgroup("cgrp_from_id_ns");
> + _exit(1);
> + } else {
> + int res;
> +
> + close(pipe_fd[1]);
> + if (!ASSERT_EQ(read(pipe_fd[0], &res, sizeof(res)), sizeof(res), "read res"))
> + goto pipe_cleanup;
> + if (!ASSERT_OK(res, "result from run"))
> + goto pipe_cleanup;
> + }
> +
> +pipe_cleanup:
> + close(pipe_fd[1]);
Nit: should this be pipe_fd[0]?
in case of a fork() failure, should this be both?
> +cleanup:
> + cgrp_kfunc_success__destroy(skel);
> +}
> +
> void test_cgrp_kfunc(void)
> {
> int i, err;
[...]
