[PATCH bpf-next 4/4] selftests/bpf: Tweak cgroup kfunc test.

[Alexei Starovoitov <alexei.starovoitov@gmail.com>]

From: Alexei Starovoitov <ast@kernel.org>

Adjust cgroup kfunc test to dereference RCU protected cgroup pointer
as PTR_TRUSTED and pass into KF_TRUSTED_ARGS kfunc.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
---
 tools/testing/selftests/bpf/progs/cgrp_kfunc_common.h  | 2 +-
 tools/testing/selftests/bpf/progs/cgrp_kfunc_failure.c | 2 +-
 tools/testing/selftests/bpf/progs/cgrp_kfunc_success.c | 9 ++++++++-
 3 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/tools/testing/selftests/bpf/progs/cgrp_kfunc_common.h b/tools/testing/selftests/bpf/progs/cgrp_kfunc_common.h
index 50d8660ffa26..eb5bf3125816 100644
--- a/tools/testing/selftests/bpf/progs/cgrp_kfunc_common.h
+++ b/tools/testing/selftests/bpf/progs/cgrp_kfunc_common.h
@@ -10,7 +10,7 @@
 #include <bpf/bpf_tracing.h>
 
 struct __cgrps_kfunc_map_value {
-	struct cgroup __kptr * cgrp;
+	struct cgroup __kptr_rcu * cgrp;
 };
 
 struct hash_map {
diff --git a/tools/testing/selftests/bpf/progs/cgrp_kfunc_failure.c b/tools/testing/selftests/bpf/progs/cgrp_kfunc_failure.c
index 4ad7fe24966d..d5a53b5e708f 100644
--- a/tools/testing/selftests/bpf/progs/cgrp_kfunc_failure.c
+++ b/tools/testing/selftests/bpf/progs/cgrp_kfunc_failure.c
@@ -205,7 +205,7 @@ int BPF_PROG(cgrp_kfunc_get_unreleased, struct cgroup *cgrp, const char *path)
 }
 
 SEC("tp_btf/cgroup_mkdir")
-__failure __msg("arg#0 is untrusted_ptr_or_null_ expected ptr_ or socket")
+__failure __msg("bpf_cgroup_release expects refcounted")
 int BPF_PROG(cgrp_kfunc_release_untrusted, struct cgroup *cgrp, const char *path)
 {
 	struct __cgrps_kfunc_map_value *v;
diff --git a/tools/testing/selftests/bpf/progs/cgrp_kfunc_success.c b/tools/testing/selftests/bpf/progs/cgrp_kfunc_success.c
index 0c23ea32df9f..0ce9cb00dad2 100644
--- a/tools/testing/selftests/bpf/progs/cgrp_kfunc_success.c
+++ b/tools/testing/selftests/bpf/progs/cgrp_kfunc_success.c
@@ -61,7 +61,7 @@ int BPF_PROG(test_cgrp_acquire_leave_in_map, struct cgroup *cgrp, const char *pa
 SEC("tp_btf/cgroup_mkdir")
 int BPF_PROG(test_cgrp_xchg_release, struct cgroup *cgrp, const char *path)
 {
-	struct cgroup *kptr;
+	struct cgroup *kptr, *cg;
 	struct __cgrps_kfunc_map_value *v;
 	long status;
 
@@ -80,6 +80,13 @@ int BPF_PROG(test_cgrp_xchg_release, struct cgroup *cgrp, const char *path)
 		return 0;
 	}
 
+	kptr = v->cgrp;
+	if (!kptr)
+		return 0;
+	cg = bpf_cgroup_ancestor(kptr, 1);
+	if (cg)
+		bpf_cgroup_release(cg);
+
 	kptr = bpf_kptr_xchg(&v->cgrp, NULL);
 	if (!kptr) {
 		err = 3;
-- 
2.30.2