diff options
| author | Kumar Kartikeya Dwivedi <memxor@gmail.com> | 2025-09-15 03:26:18 +0000 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2025-09-15 10:53:15 -0700 |
| commit | a8250d167c0cf6b98ccb5168fb2daf2859679d72 (patch) | |
| tree | 8cf0583f633fa911f1969bb356b8009c571051a0 /tools/testing/selftests/bpf/cgroup_helpers.c | |
| parent | 2c895133950646f45e5cf3900b168c952c8dbee8 (diff) | |
selftests/bpf: Add a test for bpf_cgroup_from_id lookup in non-root cgns
Make sure that we only switch the cgroup namespace and enter a new
cgroup in a child process separate from test_progs, to not mess up the
environment for subsequent tests.
To remove this cgroup, we need to wait for the child to exit, and then
rmdir its cgroup. If the read call fails, or waitpid succeeds, we know
the child exited (read call would fail when the last pipe end is closed,
otherwise waitpid waits until exit(2) is called). We then invoke a newly
introduced remove_cgroup_pid() helper, that identifies cgroup path using
the passed in pid of the now dead child, instead of using the current
process pid (getpid()).
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20250915032618.1551762-3-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'tools/testing/selftests/bpf/cgroup_helpers.c')
| -rw-r--r-- | tools/testing/selftests/bpf/cgroup_helpers.c | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/cgroup_helpers.c b/tools/testing/selftests/bpf/cgroup_helpers.c index 15f626014872..20cede4db3ce 100644 --- a/tools/testing/selftests/bpf/cgroup_helpers.c +++ b/tools/testing/selftests/bpf/cgroup_helpers.c @@ -412,6 +412,26 @@ void remove_cgroup(const char *relative_path) log_err("rmdiring cgroup %s .. %s", relative_path, cgroup_path); } +/* + * remove_cgroup_pid() - Remove a cgroup setup by process identified by PID + * @relative_path: The cgroup path, relative to the workdir, to remove + * @pid: PID to be used to find cgroup_path + * + * This function expects a cgroup to already be created, relative to the cgroup + * work dir. It also expects the cgroup doesn't have any children or live + * processes and it removes the cgroup. + * + * On failure, it will print an error to stderr. + */ +void remove_cgroup_pid(const char *relative_path, int pid) +{ + char cgroup_path[PATH_MAX + 1]; + + format_cgroup_path_pid(cgroup_path, relative_path, pid); + if (rmdir(cgroup_path)) + log_err("rmdiring cgroup %s .. %s", relative_path, cgroup_path); +} + /** * create_and_get_cgroup() - Create a cgroup, relative to workdir, and get the FD * @relative_path: The cgroup path, relative to the workdir, to join |