[PATCH v3 bpf-next 5/5] selftests/bpf: Tweak cgroup kfunc test.

Alexei Starovoitov
2023-02-28T04:02:34Z

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_failure.c | 2 +-
tools/testing/selftests/bpf/progs/cgrp_kfunc_success.c | 7 ++++++-
2 files changed, 7 insertions(+), 2 deletions(-)

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 42e13aebdd62..85becaa8573b 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 +80,11 @@ int BPF_PROG(test_cgrp_xchg_release, struct cgroup *cgrp, const char *path)
return 0;
}

+ kptr = v->cgrp;
+ cg = bpf_cgroup_ancestor(kptr, 1);
+ if (cg) /* verifier only check */
+ bpf_cgroup_release(cg);
+
kptr = bpf_kptr_xchg(&v->cgrp, NULL);
if (!kptr) {
err = 3;
--
2.30.2