[PATCH RFC bpf-next v1 6/6] selftests/bpf: Add referenced PTR_TO_BTF_ID selftest

[Kumar Kartikeya Dwivedi <memxor@gmail.com>]

Use the prog_test kfuncs to test the referenced PTR_TO_BTF_ID kfunc
support.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
---
 tools/testing/selftests/bpf/Makefile          |  2 +-
 tools/testing/selftests/bpf/bpf_tcp_helpers.h |  5 +++++
 .../selftests/bpf/prog_tests/kfunc_call.c     | 18 ++++++++++------
 .../selftests/bpf/progs/kfunc_call_test.c     | 21 +++++++++++++++++++
 4 files changed, 39 insertions(+), 7 deletions(-)

diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
index f49cb5fc85af..36c284464599 100644
--- a/tools/testing/selftests/bpf/Makefile
+++ b/tools/testing/selftests/bpf/Makefile
@@ -322,7 +322,7 @@ SKEL_BLACKLIST := btf__% test_pinning_invalid.c test_sk_assign.c
 LINKED_SKELS := test_static_linked.skel.h linked_funcs.skel.h		\
 		linked_vars.skel.h linked_maps.skel.h
 
-LSKELS := kfunc_call_test.c fentry_test.c fexit_test.c fexit_sleep.c \
+LSKELS := fentry_test.c fexit_test.c fexit_sleep.c \
 	test_ringbuf.c atomics.c trace_printk.c trace_vprintk.c
 # Generate both light skeleton and libbpf skeleton for these
 LSKELS_EXTRA := test_ksyms_module.c test_ksyms_weak.c
diff --git a/tools/testing/selftests/bpf/bpf_tcp_helpers.h b/tools/testing/selftests/bpf/bpf_tcp_helpers.h
index b1ede6f0b821..f7fe596d2c7e 100644
--- a/tools/testing/selftests/bpf/bpf_tcp_helpers.h
+++ b/tools/testing/selftests/bpf/bpf_tcp_helpers.h
@@ -185,6 +185,11 @@ struct tcp_congestion_ops {
 	void *owner;
 };
 
+struct prog_test_ref_kfunc {
+	int a;
+	int b;
+} __attribute__((preserve_access_index));
+
 #define min(a, b) ((a) < (b) ? (a) : (b))
 #define max(a, b) ((a) > (b) ? (a) : (b))
 #define min_not_zero(x, y) ({			\
diff --git a/tools/testing/selftests/bpf/prog_tests/kfunc_call.c b/tools/testing/selftests/bpf/prog_tests/kfunc_call.c
index 5c9c0176991b..358b905ea9b5 100644
--- a/tools/testing/selftests/bpf/prog_tests/kfunc_call.c
+++ b/tools/testing/selftests/bpf/prog_tests/kfunc_call.c
@@ -2,31 +2,37 @@
 /* Copyright (c) 2021 Facebook */
 #include <test_progs.h>
 #include <network_helpers.h>
-#include "kfunc_call_test.lskel.h"
+#include "kfunc_call_test.skel.h"
 #include "kfunc_call_test_subprog.skel.h"
 
 static void test_main(void)
 {
-	struct kfunc_call_test_lskel *skel;
+	struct kfunc_call_test *skel;
 	int prog_fd, retval, err;
 
-	skel = kfunc_call_test_lskel__open_and_load();
+	skel = kfunc_call_test__open_and_load();
 	if (!ASSERT_OK_PTR(skel, "skel"))
 		return;
 
-	prog_fd = skel->progs.kfunc_call_test1.prog_fd;
+	prog_fd = bpf_program__fd(skel->progs.kfunc_call_test1);
 	err = bpf_prog_test_run(prog_fd, 1, &pkt_v4, sizeof(pkt_v4),
 				NULL, NULL, (__u32 *)&retval, NULL);
 	ASSERT_OK(err, "bpf_prog_test_run(test1)");
 	ASSERT_EQ(retval, 12, "test1-retval");
 
-	prog_fd = skel->progs.kfunc_call_test2.prog_fd;
+	prog_fd = bpf_program__fd(skel->progs.kfunc_call_test2);
 	err = bpf_prog_test_run(prog_fd, 1, &pkt_v4, sizeof(pkt_v4),
 				NULL, NULL, (__u32 *)&retval, NULL);
 	ASSERT_OK(err, "bpf_prog_test_run(test2)");
 	ASSERT_EQ(retval, 3, "test2-retval");
 
-	kfunc_call_test_lskel__destroy(skel);
+	prog_fd = bpf_program__fd(skel->progs.kfunc_call_test_ref_btf_id);
+	err = bpf_prog_test_run(prog_fd, 1, &pkt_v4, sizeof(pkt_v4),
+				NULL, NULL, (__u32 *)&retval, NULL);
+	ASSERT_OK(err, "bpf_prog_test_run(test_ref_btf_id)");
+	ASSERT_EQ(retval, 0, "test_ref_btf_id-retval");
+
+	kfunc_call_test__destroy(skel);
 }
 
 static void test_subprog(void)
diff --git a/tools/testing/selftests/bpf/progs/kfunc_call_test.c b/tools/testing/selftests/bpf/progs/kfunc_call_test.c
index 8a8cf59017aa..045f157309b6 100644
--- a/tools/testing/selftests/bpf/progs/kfunc_call_test.c
+++ b/tools/testing/selftests/bpf/progs/kfunc_call_test.c
@@ -7,6 +7,8 @@
 extern int bpf_kfunc_call_test2(struct sock *sk, __u32 a, __u32 b) __ksym;
 extern __u64 bpf_kfunc_call_test1(struct sock *sk, __u32 a, __u64 b,
 				  __u32 c, __u64 d) __ksym;
+extern struct prog_test_ref_kfunc *bpf_kfunc_call_test_acquire(char *packet) __ksym;
+extern void bpf_kfunc_call_test_release(struct prog_test_ref_kfunc *p) __ksym;
 
 SEC("tc")
 int kfunc_call_test2(struct __sk_buff *skb)
@@ -44,4 +46,23 @@ int kfunc_call_test1(struct __sk_buff *skb)
 	return ret;
 }
 
+SEC("tc")
+int kfunc_call_test_ref_btf_id(struct __sk_buff *skb)
+{
+	struct bpf_sock_tuple tuple = {};
+	struct prog_test_ref_kfunc *pt;
+	struct nf_conn *ct = NULL;
+	char *p = &(char){0};
+	__u64 flags_err = 0;
+	int ret = 0;
+
+	pt = bpf_kfunc_call_test_acquire(p);
+	if (pt) {
+		if (pt->a != 42 || pt->b != 108)
+			ret = -1;
+		bpf_kfunc_call_test_release(pt);
+	}
+	return ret;
+}
+
 char _license[] SEC("license") = "GPL";
-- 
2.33.1