[PATCH bpf-next 1/5] bpf: Allow helper bpf_get_ns_current_pid_tgid() in cgroup and sk_msg programs

[Yonghong Song <yonghong.song@linux.dev>]

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.

Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
---
 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