selftests/bpf: Add test for zero offset or non-zero offset pointers as KF_ACQUIRE kfuncs argument

This patch adds test cases for zero offset (implicit cast) or non-zero
offset pointer as KF_ACQUIRE kfuncs argument. Currently KF_ACQUIRE
kfuncs should support passing in pointers like &sk->sk_write_queue
(non-zero offset) or &sk->__sk_common (zero offset) and not be rejected
by the verifier.

Signed-off-by: Juntong Deng <juntong.deng@outlook.com>
Link: https://lore.kernel.org/r/AM6PR03MB5848CB6F0D4D9068669A905B99952@AM6PR03MB5848.eurprd03.prod.outlook.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

1 files changed, 33 insertions, 0 deletions

diff --git a/tools/testing/selftests/bpf/progs/nested_acquire.c b/tools/testing/selftests/bpf/progs/nested_acquire.c
new file mode 100644
index 000000000000..8e521a21d995
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/nested_acquire.c
@@ -0,0 +1,33 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <vmlinux.h>
+#include <bpf/bpf_tracing.h>
+#include <bpf/bpf_helpers.h>
+#include "bpf_misc.h"
+#include "../bpf_testmod/bpf_testmod_kfunc.h"
+
+char _license[] SEC("license") = "GPL";
+
+SEC("tp_btf/tcp_probe")
+__success
+int BPF_PROG(test_nested_acquire_nonzero, struct sock *sk, struct sk_buff *skb)
+{
+	struct sk_buff *ptr;
+
+	ptr = bpf_kfunc_nested_acquire_nonzero_offset_test(&sk->sk_write_queue);
+
+	bpf_kfunc_nested_release_test(ptr);
+	return 0;
+}
+
+SEC("tp_btf/tcp_probe")
+__success
+int BPF_PROG(test_nested_acquire_zero, struct sock *sk, struct sk_buff *skb)
+{
+	struct sk_buff *ptr;
+
+	ptr = bpf_kfunc_nested_acquire_zero_offset_test(&sk->__sk_common);
+
+	bpf_kfunc_nested_release_test(ptr);
+	return 0;
+}