On Thu, Mar 7, 2024 at 3:27 PM Yonghong Song <yonghong.song@xxxxxxxxx> wrote: > > Currently bpf_get_current_pid_tgid() is allowed in tracing, cgroup > and sk_msg progs while bpf_get_ns_current_pid_tgid() is only allowed > in tracing progs. > > We have an internal use case where for an application running > in a container (with pid namespace), user wants to get > the pid associated with the pid namespace in a cgroup bpf > program. Currently, cgroup bpf progs already allow > bpf_get_current_pid_tgid(). Let us allow bpf_get_ns_current_pid_tgid() > as well. > > With auditing the code, bpf_get_current_pid_tgid() is also used > by sk_msg prog. So I added bpf_get_ns_current_pid_tgid() > support for sk_msg prog, so now for all places where > bpf_get_current_pid_tgid() can be used, bpf_get_ns_current_pid_tgid() > can be used as well. > If tracing can call both bpf_get_current_pid_tgid() and bpf_get_ns_current_pid_tgid(), can't we just add both into bpf_base_func_proto() and have them available for all types of BPF programs? If it's safe for tracing, it's safe for any program type, so why not? > Signed-off-by: Yonghong Song <yonghong.song@xxxxxxxxx> > --- > kernel/bpf/cgroup.c | 2 ++ > net/core/filter.c | 2 ++ > 2 files changed, 4 insertions(+) > > diff --git a/kernel/bpf/cgroup.c b/kernel/bpf/cgroup.c > index 5a568bbbeaeb..375b92204881 100644 > --- a/kernel/bpf/cgroup.c > +++ b/kernel/bpf/cgroup.c > @@ -2577,6 +2577,8 @@ cgroup_current_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) > return &bpf_get_current_uid_gid_proto; > case BPF_FUNC_get_current_pid_tgid: > return &bpf_get_current_pid_tgid_proto; > + case BPF_FUNC_get_ns_current_pid_tgid: > + return &bpf_get_ns_current_pid_tgid_proto; > case BPF_FUNC_get_current_comm: > return &bpf_get_current_comm_proto; > #ifdef CONFIG_CGROUP_NET_CLASSID > diff --git a/net/core/filter.c b/net/core/filter.c > index 8adf95765cdd..d4e43303a66b 100644 > --- a/net/core/filter.c > +++ b/net/core/filter.c > @@ -8344,6 +8344,8 @@ sk_msg_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) > return &bpf_get_current_uid_gid_proto; > case BPF_FUNC_get_current_pid_tgid: > return &bpf_get_current_pid_tgid_proto; > + case BPF_FUNC_get_ns_current_pid_tgid: > + return &bpf_get_ns_current_pid_tgid_proto; > case BPF_FUNC_sk_storage_get: > return &bpf_sk_storage_get_proto; > case BPF_FUNC_sk_storage_delete: > -- > 2.43.0 >
