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/*
* 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/Parcel.h>
#include <binder/IServiceManager.h>
#include <gtest/gtest.h>
#include <utils/CallStack.h>
#include <malloc.h>
#include <functional>
#include <vector>
struct DestructionAction {
DestructionAction(std::function<void()> f) : mF(std::move(f)) {}
~DestructionAction() { mF(); };
private:
std::function<void()> mF;
};
// Group of hooks
struct MallocHooks {
decltype(__malloc_hook) malloc_hook;
decltype(__realloc_hook) realloc_hook;
static MallocHooks save() {
return {
.malloc_hook = __malloc_hook,
.realloc_hook = __realloc_hook,
};
}
void overwrite() const {
__malloc_hook = malloc_hook;
__realloc_hook = realloc_hook;
}
};
static const MallocHooks orig_malloc_hooks = MallocHooks::save();
// When malloc is hit, executes lambda.
namespace LambdaHooks {
using AllocationHook = std::function<void(size_t)>;
static std::vector<AllocationHook> lambdas = {};
static void* lambda_realloc_hook(void* ptr, size_t bytes, const void* arg);
static void* lambda_malloc_hook(size_t bytes, const void* arg);
static const MallocHooks lambda_malloc_hooks = {
.malloc_hook = lambda_malloc_hook,
.realloc_hook = lambda_realloc_hook,
};
static void* lambda_malloc_hook(size_t bytes, const void* arg) {
{
orig_malloc_hooks.overwrite();
lambdas.at(lambdas.size() - 1)(bytes);
lambda_malloc_hooks.overwrite();
}
return orig_malloc_hooks.malloc_hook(bytes, arg);
}
static void* lambda_realloc_hook(void* ptr, size_t bytes, const void* arg) {
{
orig_malloc_hooks.overwrite();
lambdas.at(lambdas.size() - 1)(bytes);
lambda_malloc_hooks.overwrite();
}
return orig_malloc_hooks.realloc_hook(ptr, bytes, arg);
}
}
// Action to execute when malloc is hit. Supports nesting. Malloc is not
// restricted when the allocation hook is being processed.
__attribute__((warn_unused_result))
DestructionAction OnMalloc(LambdaHooks::AllocationHook f) {
MallocHooks before = MallocHooks::save();
LambdaHooks::lambdas.emplace_back(std::move(f));
LambdaHooks::lambda_malloc_hooks.overwrite();
return DestructionAction([before]() {
before.overwrite();
LambdaHooks::lambdas.pop_back();
});
}
// exported symbol, to force compiler not to optimize away pointers we set here
const void* imaginary_use;
TEST(TestTheTest, OnMalloc) {
size_t mallocs = 0;
{
const auto on_malloc = OnMalloc([&](size_t bytes) {
mallocs++;
EXPECT_EQ(bytes, 40);
});
imaginary_use = new int[10];
}
EXPECT_EQ(mallocs, 1);
}
__attribute__((warn_unused_result))
DestructionAction ScopeDisallowMalloc() {
return OnMalloc([&](size_t bytes) {
ADD_FAILURE() << "Unexpected allocation: " << bytes;
using android::CallStack;
std::cout << CallStack::stackToString("UNEXPECTED ALLOCATION", CallStack::getCurrent(4 /*ignoreDepth*/).get())
<< std::endl;
});
}
using android::IBinder;
using android::Parcel;
using android::String16;
using android::defaultServiceManager;
using android::sp;
using android::IServiceManager;
static sp<IBinder> GetRemoteBinder() {
// This gets binder representing the service manager
// the current IServiceManager API doesn't expose the binder, and
// I want to avoid adding usages of the AIDL generated interface it
// is using underneath, so to avoid people copying it.
sp<IBinder> binder = defaultServiceManager()->checkService(String16("manager"));
EXPECT_NE(nullptr, binder);
return binder;
}
TEST(BinderAllocation, ParcelOnStack) {
const auto m = ScopeDisallowMalloc();
Parcel p;
imaginary_use = p.data();
}
TEST(BinderAllocation, GetServiceManager) {
defaultServiceManager(); // first call may alloc
const auto m = ScopeDisallowMalloc();
defaultServiceManager();
}
// note, ping does not include interface descriptor
TEST(BinderAllocation, PingTransaction) {
sp<IBinder> a_binder = GetRemoteBinder();
const auto m = ScopeDisallowMalloc();
a_binder->pingBinder();
}
TEST(BinderAllocation, SmallTransaction) {
String16 empty_descriptor = String16("");
sp<IServiceManager> manager = defaultServiceManager();
size_t mallocs = 0;
const auto on_malloc = OnMalloc([&](size_t bytes) {
mallocs++;
// Parcel should allocate a small amount by default
EXPECT_EQ(bytes, 128);
});
manager->checkService(empty_descriptor);
EXPECT_EQ(mallocs, 1);
}
int main(int argc, char** argv) {
if (getenv("LIBC_HOOKS_ENABLE") == nullptr) {
CHECK(0 == setenv("LIBC_HOOKS_ENABLE", "1", true /*overwrite*/));
execv(argv[0], argv);
return 1;
}
::testing::InitGoogleTest(&argc, argv);
return RUN_ALL_TESTS();
}
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