[RFC PATCH bpf-next 15/17] selftests/bpf: Add fexit tracing multi func test

[Jiri Olsa <jolsa@kernel.org>]

Adding selftest for fexit multi func test that attaches
to bpf_fentry_test* functions and checks argument values
based on the processed function.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
 tools/testing/selftests/bpf/Makefile          |  4 ++-
 .../selftests/bpf/prog_tests/tracing_multi.c  | 28 +++++++++++++++++++
 .../selftests/bpf/progs/tracing_multi_check.c | 26 +++++++++++++++++
 .../selftests/bpf/progs/tracing_multi_fexit.c | 20 +++++++++++++
 4 files changed, 77 insertions(+), 1 deletion(-)
 create mode 100644 tools/testing/selftests/bpf/progs/tracing_multi_fexit.c

diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
index 24f0ace18af2..9c0b26e6e645 100644
--- a/tools/testing/selftests/bpf/Makefile
+++ b/tools/testing/selftests/bpf/Makefile
@@ -348,7 +348,8 @@ 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 			\
 		test_subskeleton.skel.h test_subskeleton_lib.skel.h	\
-		test_usdt.skel.h tracing_multi_fentry_test.skel.h
+		test_usdt.skel.h tracing_multi_fentry_test.skel.h	\
+		tracing_multi_fexit_test.skel.h
 
 LSKELS := kfunc_call_test.c fentry_test.c fexit_test.c fexit_sleep.c \
 	test_ringbuf.c atomics.c trace_printk.c trace_vprintk.c \
@@ -367,6 +368,7 @@ test_subskeleton.skel.h-deps := test_subskeleton_lib2.o test_subskeleton_lib.o t
 test_subskeleton_lib.skel.h-deps := test_subskeleton_lib2.o test_subskeleton_lib.o
 test_usdt.skel.h-deps := test_usdt.o test_usdt_multispec.o
 tracing_multi_fentry_test.skel.h-deps := tracing_multi_fentry.o tracing_multi_check.o
+tracing_multi_fexit_test.skel.h-deps := tracing_multi_fexit.o tracing_multi_check.o
 
 LINKED_BPF_SRCS := $(patsubst %.o,%.c,$(foreach skel,$(LINKED_SKELS),$($(skel)-deps)))
 
diff --git a/tools/testing/selftests/bpf/prog_tests/tracing_multi.c b/tools/testing/selftests/bpf/prog_tests/tracing_multi.c
index fbf2108ebb8a..b7b1e42754da 100644
--- a/tools/testing/selftests/bpf/prog_tests/tracing_multi.c
+++ b/tools/testing/selftests/bpf/prog_tests/tracing_multi.c
@@ -1,6 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0
 #include <test_progs.h>
 #include "tracing_multi_fentry_test.skel.h"
+#include "tracing_multi_fexit_test.skel.h"
 #include "trace_helpers.h"
 
 static void multi_fentry_test(void)
@@ -27,8 +28,35 @@ static void multi_fentry_test(void)
 	tracing_multi_fentry_test__destroy(skel);
 }
 
+static void multi_fexit_test(void)
+{
+	LIBBPF_OPTS(bpf_test_run_opts, topts);
+	struct tracing_multi_fexit_test *skel = NULL;
+	int err, prog_fd;
+
+	skel = tracing_multi_fexit_test__open_and_load();
+	if (!ASSERT_OK_PTR(skel, "tracing_multi_fentry_test__open_and_load"))
+		goto cleanup;
+
+	err = tracing_multi_fexit_test__attach(skel);
+	if (!ASSERT_OK(err, "tracing_multi_fentry_test__attach"))
+		goto cleanup;
+
+	prog_fd = bpf_program__fd(skel->progs.test);
+	err = bpf_prog_test_run_opts(prog_fd, &topts);
+	ASSERT_OK(err, "test_run");
+
+	ASSERT_EQ(skel->bss->test_arg_result, 8, "test_arg_result");
+	ASSERT_EQ(skel->bss->test_ret_result, 8, "test_ret_result");
+
+cleanup:
+	tracing_multi_fexit_test__destroy(skel);
+}
+
 void test_tracing_multi_test(void)
 {
 	if (test__start_subtest("fentry"))
 		multi_fentry_test();
+	if (test__start_subtest("fexit"))
+		multi_fexit_test();
 }
diff --git a/tools/testing/selftests/bpf/progs/tracing_multi_check.c b/tools/testing/selftests/bpf/progs/tracing_multi_check.c
index 945dc4d070e1..7144df65607e 100644
--- a/tools/testing/selftests/bpf/progs/tracing_multi_check.c
+++ b/tools/testing/selftests/bpf/progs/tracing_multi_check.c
@@ -130,3 +130,29 @@ void multi_arg_check(__u64 *ctx, __u64 *test_result)
 		*test_result += 1;
 	}
 }
+
+void multi_ret_check(void *ctx, __u64 *test_result)
+{
+	void *ip = (void *) bpf_get_func_ip(ctx);
+	__u64 ret = 0;
+	int err;
+
+	if (bpf_get_func_ret(ctx, &ret))
+		return;
+	if (ip == &bpf_fentry_test1)
+		*test_result += ret == 2;
+	else if (ip == &bpf_fentry_test2)
+		*test_result += ret == 5;
+	else if (ip == &bpf_fentry_test3)
+		*test_result += ret == 15;
+	else if (ip == &bpf_fentry_test4)
+		*test_result += ret == 34;
+	else if (ip == &bpf_fentry_test5)
+		*test_result += ret == 65;
+	else if (ip == &bpf_fentry_test6)
+		*test_result += ret == 111;
+	else if (ip == &bpf_fentry_test7)
+		*test_result += ret == 0;
+	else if (ip == &bpf_fentry_test8)
+		*test_result += ret == 0;
+}
diff --git a/tools/testing/selftests/bpf/progs/tracing_multi_fexit.c b/tools/testing/selftests/bpf/progs/tracing_multi_fexit.c
new file mode 100644
index 000000000000..54624acc7071
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/tracing_multi_fexit.c
@@ -0,0 +1,20 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+
+char _license[] SEC("license") = "GPL";
+
+__hidden extern void multi_arg_check(__u64 *ctx, __u64 *test_result);
+__hidden extern void multi_ret_check(void *ctx, __u64 *test_result);
+
+__u64 test_arg_result = 0;
+__u64 test_ret_result = 0;
+
+SEC("fexit.multi/bpf_fentry_test*")
+int BPF_PROG(test)
+{
+	multi_arg_check(ctx, &test_arg_result);
+	multi_ret_check(ctx, &test_ret_result);
+	return 0;
+}
-- 
2.37.1