selftests/bpf: add session cookie testcase for fsession

Test the session cookie for fsession. Multiple fsession BPF progs is
attached to bpf_fentry_test1() and session cookie is read and write in
this testcase.

Signed-off-by: Menglong Dong <[email protected]>

Author: Menglong Dong

tools/testing/selftests/bpf/progs/fsession_test.c

@@ -187,3 +187,44 @@ int BPF_PROG(test10, int a)
 		test10_entry_result = (const void *) addr == &bpf_fentry_test1;
 	return 0;
 }
+
+__u64 test11_entry_ok = 0;
+__u64 test11_exit_ok = 0;
+SEC("fsession/bpf_fentry_test1")
+int BPF_PROG(test11, int a)
+{
+	__u64 *cookie = bpf_fsession_cookie(ctx);
+
+	if (!bpf_tracing_is_exit(ctx)) {
+		if (cookie) {
+			*cookie = 0xAAAABBBBCCCCDDDDull;
+			test11_entry_ok = *cookie == 0xAAAABBBBCCCCDDDDull;
+		}
+		return 0;
+	}
+
+	if (cookie)
+		test11_exit_ok = *cookie == 0xAAAABBBBCCCCDDDDull;
+	return 0;
+}
+
+__u64 test12_entry_ok = 0;
+__u64 test12_exit_ok = 0;
+
+SEC("fsession/bpf_fentry_test1")
+int BPF_PROG(test12, int a)
+{
+	__u64 *cookie = bpf_fsession_cookie(ctx);
+
+	if (!bpf_tracing_is_exit(ctx)) {
+		if (cookie) {
+			*cookie = 0x1111222233334444ull;
+			test12_entry_ok = *cookie == 0x1111222233334444ull;
+		}
+		return 0;
+	}
+
+	if (cookie)
+		test12_exit_ok = *cookie == 0x1111222233334444ull;
+	return 0;
+}