| /* |
| * 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. |
| */ |
| |
| #include <android-base/logging.h> |
| #include <binder/Binder.h> |
| #include <binder/IBinder.h> |
| #include <binder/IPCThreadState.h> |
| #include <binder/IServiceManager.h> |
| #include <binder/Parcel.h> |
| #include <binder/Stability.h> |
| #include <gtest/gtest.h> |
| |
| #include "../Utils.h" |
| |
| #include <sys/prctl.h> |
| #include <thread> |
| |
| using namespace android; |
| |
| const String16 kServerName = String16("binderClearBuf"); |
| |
| class FooBar : public BBinder { |
| public: |
| enum { |
| TRANSACTION_REPEAT_STRING = IBinder::FIRST_CALL_TRANSACTION, |
| }; |
| |
| std::mutex foo; |
| std::string last; |
| |
| status_t onTransact(uint32_t code, const Parcel& data, Parcel* reply, uint32_t flags) { |
| // not checking data, since there is no hook at the time this test is |
| // written to check values there are set to zero. Instead, we only check |
| // the reply parcel. |
| |
| switch (code) { |
| case TRANSACTION_REPEAT_STRING: { |
| const char* str = data.readCString(); |
| return reply->writeCString(str == nullptr ? "<null>" : str); |
| } |
| } |
| return BBinder::onTransact(code, data, reply, flags); |
| } |
| static std::string RepeatString(const sp<IBinder> binder, |
| const std::string& repeat, |
| std::string* outBuffer) { |
| Parcel data; |
| data.writeCString(repeat.c_str()); |
| std::string result; |
| const uint8_t* lastReply; |
| size_t lastReplySize; |
| { |
| Parcel reply; |
| binder->transact(TRANSACTION_REPEAT_STRING, data, &reply, FLAG_CLEAR_BUF); |
| result = reply.readCString(); |
| lastReply = reply.data(); |
| lastReplySize = reply.dataSize(); |
| } |
| *outBuffer = android::HexString(lastReply, lastReplySize); |
| return result; |
| } |
| }; |
| |
| TEST(BinderClearBuf, ClearKernelBuffer) { |
| LIBBINDER_IGNORE("-Wdeprecated-declarations") |
| sp<IBinder> binder = defaultServiceManager()->getService(kServerName); |
| LIBBINDER_IGNORE_END() |
| ASSERT_NE(nullptr, binder); |
| |
| std::string replyBuffer; |
| std::string result = FooBar::RepeatString(binder, "foo", &replyBuffer); |
| EXPECT_EQ("foo", result); |
| |
| // the buffer must have at least some length for the string, but we will |
| // just check it has some length, to avoid assuming anything about the |
| // format |
| EXPECT_GT(replyBuffer.size(), 0u); |
| |
| for (size_t i = 0; i < replyBuffer.size(); i++) { |
| EXPECT_EQ(replyBuffer[i], '0') << "reply buffer at " << i; |
| } |
| } |
| |
| int main(int argc, char** argv) { |
| ::testing::InitGoogleTest(&argc, argv); |
| |
| if (fork() == 0) { |
| prctl(PR_SET_PDEATHSIG, SIGHUP); |
| |
| sp<IBinder> server = new FooBar; |
| android::defaultServiceManager()->addService(kServerName, server); |
| |
| IPCThreadState::self()->joinThreadPool(true); |
| exit(1); // should not reach |
| } |
| |
| // This is not racey. Just giving these services some time to register before we call |
| // getService which sleeps for much longer. One alternative would be to |
| // start a threadpool + use waitForService, but we want to have as few |
| // binder things going on in this test as possible, since we are checking |
| // memory is zero'd which the kernel has a right to change. |
| usleep(100000); |
| |
| return RUN_ALL_TESTS(); |
| } |