Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
From:   David Vernet <void@manifault.com>
To:     bpf@vger.kernel.org
Cc:     ast@kernel.org, andrii@kernel.org, daniel@iogearbox.net,
        martin.lau@linux.dev, yhs@fb.com, song@kernel.org, sdf@google.com,
        john.fastabend@gmail.com, kpsingh@kernel.org, jolsa@kernel.org,
        haoluo@google.com, tj@kernel.org, kernel-team@fb.com,
        linux-kernel@vger.kernel.org
Subject: [PATCH bpf-next 4/4] selftests/bpf: Add selftests for bpf_cgroup_ancestor() kfunc
Date:   Mon, 21 Nov 2022 23:54:58 -0600
Message-Id: <20221122055458.173143-5-void@manifault.com>
In-Reply-To: <20221122055458.173143-1-void@manifault.com>
References: <20221122055458.173143-1-void@manifault.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

bpf_cgroup_ancestor() allows BPF programs to access the ancestor of a
struct cgroup *. This patch adds selftests that validate its expected
behavior.

Signed-off-by: David Vernet <void@manifault.com>
---
 .../selftests/bpf/prog_tests/cgrp_kfunc.c     |  1 +
 .../selftests/bpf/progs/cgrp_kfunc_common.h   |  1 +
 .../selftests/bpf/progs/cgrp_kfunc_success.c  | 45 +++++++++++++++++++
 3 files changed, 47 insertions(+)

diff --git a/tools/testing/selftests/bpf/prog_tests/cgrp_kfunc.c b/tools/testing/selftests/bpf/prog_tests/cgrp_kfunc.c
index a59b166bbcc4..973f0c5af965 100644
--- a/tools/testing/selftests/bpf/prog_tests/cgrp_kfunc.c
+++ b/tools/testing/selftests/bpf/prog_tests/cgrp_kfunc.c
@@ -86,6 +86,7 @@ static const char * const success_tests[] = {
 	"test_cgrp_acquire_leave_in_map",
 	"test_cgrp_xchg_release",
 	"test_cgrp_get_release",
+	"test_cgrp_get_ancestors",
 };
 
 static struct {
diff --git a/tools/testing/selftests/bpf/progs/cgrp_kfunc_common.h b/tools/testing/selftests/bpf/progs/cgrp_kfunc_common.h
index 3f18def0e45c..7d30855bfe78 100644
--- a/tools/testing/selftests/bpf/progs/cgrp_kfunc_common.h
+++ b/tools/testing/selftests/bpf/progs/cgrp_kfunc_common.h
@@ -23,6 +23,7 @@ struct hash_map {
 struct cgroup *bpf_cgroup_acquire(struct cgroup *p) __ksym;
 struct cgroup *bpf_cgroup_kptr_get(struct cgroup **pp) __ksym;
 void bpf_cgroup_release(struct cgroup *p) __ksym;
+struct cgroup *bpf_cgroup_ancestor(struct cgroup *cgrp, int level) __ksym;
 
 static inline struct __cgrps_kfunc_map_value *cgrps_kfunc_map_value_lookup(struct cgroup *cgrp)
 {
diff --git a/tools/testing/selftests/bpf/progs/cgrp_kfunc_success.c b/tools/testing/selftests/bpf/progs/cgrp_kfunc_success.c
index 9f4569f7598b..0c23ea32df9f 100644
--- a/tools/testing/selftests/bpf/progs/cgrp_kfunc_success.c
+++ b/tools/testing/selftests/bpf/progs/cgrp_kfunc_success.c
@@ -123,3 +123,48 @@ int BPF_PROG(test_cgrp_get_release, struct cgroup *cgrp, const char *path)
 
 	return 0;
 }
+
+SEC("tp_btf/cgroup_mkdir")
+int BPF_PROG(test_cgrp_get_ancestors, struct cgroup *cgrp, const char *path)
+{
+	struct cgroup *self, *ancestor1, *invalid;
+
+	if (!is_test_kfunc_task())
+		return 0;
+
+	self = bpf_cgroup_ancestor(cgrp, cgrp->level);
+	if (!self) {
+		err = 1;
+		return 0;
+	}
+
+	if (self->self.id != cgrp->self.id) {
+		bpf_cgroup_release(self);
+		err = 2;
+		return 0;
+	}
+	bpf_cgroup_release(self);
+
+	ancestor1 = bpf_cgroup_ancestor(cgrp, cgrp->level - 1);
+	if (!ancestor1) {
+		err = 3;
+		return 0;
+	}
+	bpf_cgroup_release(ancestor1);
+
+	invalid = bpf_cgroup_ancestor(cgrp, 10000);
+	if (invalid) {
+		bpf_cgroup_release(invalid);
+		err = 4;
+		return 0;
+	}
+
+	invalid = bpf_cgroup_ancestor(cgrp, -1);
+	if (invalid) {
+		bpf_cgroup_release(invalid);
+		err = 5;
+		return 0;
+	}
+
+	return 0;
+}
-- 
2.38.1