binder tests respect libbinder bitness

Some 32-bit kernels use a binder kernel interface with a different API
controlled by the kernel configuration CONFIG_ANDROID_BINDER_IPC_32BIT.
This changes builds versions of these tests built for this bitness
specially so that they can run and work on these devices.

Test: atest --all binderLibTest{,_IPC_32} binderDriverInterfaceTest{,_IPC_32}
Bug: 154755898

Change-Id: I82b47e8064564a037bf8ed453e9ae7b8901b5667
diff --git a/libs/binder/tests/Android.bp b/libs/binder/tests/Android.bp
index 69fdd7c..c0da2cd 100644
--- a/libs/binder/tests/Android.bp
+++ b/libs/binder/tests/Android.bp
@@ -27,7 +27,9 @@
     defaults: ["binder_test_defaults"],
     srcs: ["binderDriverInterfaceTest.cpp"],
     compile_multilib: "32",
+    multilib: { lib32: { suffix: "" } },
     cflags: ["-DBINDER_IPC_32BIT=1"],
+    test_suites: ["vts"],
 }
 
 cc_test {
@@ -52,7 +54,10 @@
         "libutils",
     ],
     compile_multilib: "32",
+    multilib: { lib32: { suffix: "" } },
     cflags: ["-DBINDER_IPC_32BIT=1"],
+    test_suites: ["vts"],
+    require_root: true,
 }
 
 cc_test {
diff --git a/libs/binder/tests/binderAbiHelper.h b/libs/binder/tests/binderAbiHelper.h
new file mode 100644
index 0000000..369b55d
--- /dev/null
+++ b/libs/binder/tests/binderAbiHelper.h
@@ -0,0 +1,52 @@
+/*
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include <stdlib.h>
+#include <iostream>
+
+#ifdef BINDER_IPC_32BIT
+static constexpr bool kBuild32Abi = true;
+#else
+static constexpr bool kBuild32Abi = false;
+#endif
+
+// TODO: remove when CONFIG_ANDROID_BINDER_IPC_32BIT is no longer supported
+static inline bool ReadKernelConfigIs32BitAbi() {
+    // failure case implies we run with standard ABI
+    return 0 == system("zcat /proc/config.gz | grep -E \"^CONFIG_ANDROID_BINDER_IPC_32BIT=y$\"");
+}
+
+static inline void ExitIfWrongAbi() {
+    bool runtime32Abi = ReadKernelConfigIs32BitAbi();
+
+    if (kBuild32Abi != runtime32Abi) {
+        std::cout << "[==========] Running 1 test from 1 test suite." << std::endl;
+        std::cout << "[----------] Global test environment set-up." << std::endl;
+        std::cout << "[----------] 1 tests from BinderLibTest" << std::endl;
+        std::cout << "[ RUN      ] BinderTest.AbortForWrongAbi" << std::endl;
+        std::cout << "[ INFO     ] test build abi 32: " << kBuild32Abi << " runtime abi 32: " << runtime32Abi << " so, skipping tests " << std::endl;
+        std::cout << "[       OK ] BinderTest.AbortForWrongAbi (0 ms) " << std::endl;
+        std::cout << "[----------] 1 tests from BinderTest (0 ms total)" << std::endl;
+        std::cout << "" << std::endl;
+        std::cout << "[----------] Global test environment tear-down" << std::endl;
+        std::cout << "[==========] 1 test from 1 test suite ran. (0 ms total)" << std::endl;
+        std::cout << "[  PASSED  ] 1 tests." << std::endl;
+        exit(0);
+    }
+}
+
diff --git a/libs/binder/tests/binderDriverInterfaceTest.cpp b/libs/binder/tests/binderDriverInterfaceTest.cpp
index f3ed6a6..8cc3054 100644
--- a/libs/binder/tests/binderDriverInterfaceTest.cpp
+++ b/libs/binder/tests/binderDriverInterfaceTest.cpp
@@ -25,6 +25,8 @@
 #include <sys/mman.h>
 #include <poll.h>
 
+#include "binderAbiHelper.h"
+
 #define BINDER_DEV_NAME "/dev/binder"
 
 testing::Environment* binder_env;
@@ -361,6 +363,7 @@
 }
 
 int main(int argc, char **argv) {
+    ExitIfWrongAbi();
     ::testing::InitGoogleTest(&argc, argv);
 
     binder_env = AddGlobalTestEnvironment(new BinderDriverInterfaceTestEnv());
diff --git a/libs/binder/tests/binderLibTest.cpp b/libs/binder/tests/binderLibTest.cpp
index e343df7..40de2db 100644
--- a/libs/binder/tests/binderLibTest.cpp
+++ b/libs/binder/tests/binderLibTest.cpp
@@ -32,6 +32,8 @@
 #include <sys/epoll.h>
 #include <sys/prctl.h>
 
+#include "binderAbiHelper.h"
+
 #define ARRAY_SIZE(array) (sizeof array / sizeof array[0])
 
 using namespace android;
@@ -1451,6 +1453,8 @@
 }
 
 int main(int argc, char **argv) {
+    ExitIfWrongAbi();
+
     if (argc == 4 && !strcmp(argv[1], "--servername")) {
         binderservername = argv[2];
     } else {