selftests/bpf: Add struct argument tests with fentry/fexit programs.

Add various struct argument tests with fentry/fexit programs.
Also add one test with a kernel func which does not have any
argument to test BPF_PROG2 macro in such situation.

Signed-off-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/r/20220831152713.2080039-1-yhs@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

1 files changed, 120 insertions, 0 deletions

diff --git a/tools/testing/selftests/bpf/progs/tracing_struct.c b/tools/testing/selftests/bpf/progs/tracing_struct.c
new file mode 100644
index 000000000000..e718f0ebee7d
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/tracing_struct.c
@@ -0,0 +1,120 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2022 Meta Platforms, Inc. and affiliates. */
+
+#include <vmlinux.h>
+#include <bpf/bpf_tracing.h>
+#include <bpf/bpf_helpers.h>
+
+struct bpf_testmod_struct_arg_1 {
+	int a;
+};
+struct bpf_testmod_struct_arg_2 {
+	long a;
+	long b;
+};
+
+long t1_a_a, t1_a_b, t1_b, t1_c, t1_ret, t1_nregs;
+__u64 t1_reg0, t1_reg1, t1_reg2, t1_reg3;
+long t2_a, t2_b_a, t2_b_b, t2_c, t2_ret;
+long t3_a, t3_b, t3_c_a, t3_c_b, t3_ret;
+long t4_a_a, t4_b, t4_c, t4_d, t4_e_a, t4_e_b, t4_ret;
+long t5_ret;
+
+SEC("fentry/bpf_testmod_test_struct_arg_1")
+int BPF_PROG2(test_struct_arg_1, struct bpf_testmod_struct_arg_2, a, int, b, int, c)
+{
+	t1_a_a = a.a;
+	t1_a_b = a.b;
+	t1_b = b;
+	t1_c = c;
+	return 0;
+}
+
+SEC("fexit/bpf_testmod_test_struct_arg_1")
+int BPF_PROG2(test_struct_arg_2, struct bpf_testmod_struct_arg_2, a, int, b, int, c, int, ret)
+{
+	t1_nregs =  bpf_get_func_arg_cnt(ctx);
+	/* a.a */
+	bpf_get_func_arg(ctx, 0, &t1_reg0);
+	/* a.b */
+	bpf_get_func_arg(ctx, 1, &t1_reg1);
+	/* b */
+	bpf_get_func_arg(ctx, 2, &t1_reg2);
+	t1_reg2 = (int)t1_reg2;
+	/* c */
+	bpf_get_func_arg(ctx, 3, &t1_reg3);
+	t1_reg3 = (int)t1_reg3;
+
+	t1_ret = ret;
+	return 0;
+}
+
+SEC("fentry/bpf_testmod_test_struct_arg_2")
+int BPF_PROG2(test_struct_arg_3, int, a, struct bpf_testmod_struct_arg_2, b, int, c)
+{
+	t2_a = a;
+	t2_b_a = b.a;
+	t2_b_b = b.b;
+	t2_c = c;
+	return 0;
+}
+
+SEC("fexit/bpf_testmod_test_struct_arg_2")
+int BPF_PROG2(test_struct_arg_4, int, a, struct bpf_testmod_struct_arg_2, b, int, c, int, ret)
+{
+	t2_ret = ret;
+	return 0;
+}
+
+SEC("fentry/bpf_testmod_test_struct_arg_3")
+int BPF_PROG2(test_struct_arg_5, int, a, int, b, struct bpf_testmod_struct_arg_2, c)
+{
+	t3_a = a;
+	t3_b = b;
+	t3_c_a = c.a;
+	t3_c_b = c.b;
+	return 0;
+}
+
+SEC("fexit/bpf_testmod_test_struct_arg_3")
+int BPF_PROG2(test_struct_arg_6, int, a, int, b, struct bpf_testmod_struct_arg_2, c, int, ret)
+{
+	t3_ret = ret;
+	return 0;
+}
+
+SEC("fentry/bpf_testmod_test_struct_arg_4")
+int BPF_PROG2(test_struct_arg_7, struct bpf_testmod_struct_arg_1, a, int, b,
+	     int, c, int, d, struct bpf_testmod_struct_arg_2, e)
+{
+	t4_a_a = a.a;
+	t4_b = b;
+	t4_c = c;
+	t4_d = d;
+	t4_e_a = e.a;
+	t4_e_b = e.b;
+	return 0;
+}
+
+SEC("fexit/bpf_testmod_test_struct_arg_4")
+int BPF_PROG2(test_struct_arg_8, struct bpf_testmod_struct_arg_1, a, int, b,
+	     int, c, int, d, struct bpf_testmod_struct_arg_2, e, int, ret)
+{
+	t4_ret = ret;
+	return 0;
+}
+
+SEC("fentry/bpf_testmod_test_struct_arg_5")
+int BPF_PROG2(test_struct_arg_9)
+{
+	return 0;
+}
+
+SEC("fexit/bpf_testmod_test_struct_arg_5")
+int BPF_PROG2(test_struct_arg_10, int, ret)
+{
+	t5_ret = ret;
+	return 0;
+}
+
+char _license[] SEC("license") = "GPL";