diff options
Diffstat (limited to 'tools/testing/selftests/bpf/prog_tests/cgroup_iter.c')
| -rw-r--r-- | tools/testing/selftests/bpf/prog_tests/cgroup_iter.c | 76 |
1 files changed, 76 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/prog_tests/cgroup_iter.c b/tools/testing/selftests/bpf/prog_tests/cgroup_iter.c index c4a2adb38da1..e02feb5fae97 100644 --- a/tools/testing/selftests/bpf/prog_tests/cgroup_iter.c +++ b/tools/testing/selftests/bpf/prog_tests/cgroup_iter.c @@ -189,6 +189,80 @@ static void test_walk_self_only(struct cgroup_iter *skel) BPF_CGROUP_ITER_SELF_ONLY, "self_only"); } +static void test_walk_dead_self_only(struct cgroup_iter *skel) +{ + DECLARE_LIBBPF_OPTS(bpf_iter_attach_opts, opts); + char expected_output[128], buf[128]; + const char *cgrp_name = "/dead"; + union bpf_iter_link_info linfo; + int len, cgrp_fd, iter_fd; + struct bpf_link *link; + size_t left; + char *p; + + cgrp_fd = create_and_get_cgroup(cgrp_name); + if (!ASSERT_GE(cgrp_fd, 0, "create cgrp")) + return; + + /* The cgroup will be dead during read() iteration, so it only has + * epilogue in the output + */ + snprintf(expected_output, sizeof(expected_output), EPILOGUE); + + memset(&linfo, 0, sizeof(linfo)); + linfo.cgroup.cgroup_fd = cgrp_fd; + linfo.cgroup.order = BPF_CGROUP_ITER_SELF_ONLY; + opts.link_info = &linfo; + opts.link_info_len = sizeof(linfo); + + link = bpf_program__attach_iter(skel->progs.cgroup_id_printer, &opts); + if (!ASSERT_OK_PTR(link, "attach_iter")) + goto close_cgrp; + + iter_fd = bpf_iter_create(bpf_link__fd(link)); + if (!ASSERT_GE(iter_fd, 0, "iter_create")) + goto free_link; + + /* Close link fd and cgroup fd */ + bpf_link__destroy(link); + close(cgrp_fd); + + /* Remove cgroup to mark it as dead */ + remove_cgroup(cgrp_name); + + /* Two kern_sync_rcu() and usleep() pairs are used to wait for the + * releases of cgroup css, and the last kern_sync_rcu() and usleep() + * pair is used to wait for the free of cgroup itself. + */ + kern_sync_rcu(); + usleep(8000); + kern_sync_rcu(); + usleep(8000); + kern_sync_rcu(); + usleep(1000); + + memset(buf, 0, sizeof(buf)); + left = ARRAY_SIZE(buf); + p = buf; + while ((len = read(iter_fd, p, left)) > 0) { + p += len; + left -= len; + } + + ASSERT_STREQ(buf, expected_output, "dead cgroup output"); + + /* read() after iter finishes should be ok. */ + if (len == 0) + ASSERT_OK(read(iter_fd, buf, sizeof(buf)), "second_read"); + + close(iter_fd); + return; +free_link: + bpf_link__destroy(link); +close_cgrp: + close(cgrp_fd); +} + void test_cgroup_iter(void) { struct cgroup_iter *skel = NULL; @@ -217,6 +291,8 @@ void test_cgroup_iter(void) test_early_termination(skel); if (test__start_subtest("cgroup_iter__self_only")) test_walk_self_only(skel); + if (test__start_subtest("cgroup_iter__dead_self_only")) + test_walk_dead_self_only(skel); out: cgroup_iter__destroy(skel); cleanup_cgroups(); |