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/*
* Copyright (C) 2005 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.
*/
#define LOG_TAG "hw-ProcessState"
#include <hwbinder/ProcessState.h>
#include <cutils/atomic.h>
#include <hwbinder/HidlSupport.h>
#include <hwbinder/BpHwBinder.h>
#include <hwbinder/IPCThreadState.h>
#include <utils/Log.h>
#include <utils/String8.h>
#include <utils/threads.h>
#include "binder_kernel.h"
#include <hwbinder/Static.h>
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <mutex>
#define DEFAULT_BINDER_VM_SIZE ((1 * 1024 * 1024) - sysconf(_SC_PAGE_SIZE) * 2)
#define DEFAULT_MAX_BINDER_THREADS 0
#define DEFAULT_ENABLE_ONEWAY_SPAM_DETECTION 1
// -------------------------------------------------------------------------
namespace android {
namespace hardware {
class PoolThread : public Thread
{
public:
explicit PoolThread(bool isMain)
: mIsMain(isMain)
{
}
protected:
virtual bool threadLoop()
{
IPCThreadState::self()->joinThreadPool(mIsMain);
return false;
}
const bool mIsMain;
};
sp<ProcessState> ProcessState::self()
{
return init(DEFAULT_BINDER_VM_SIZE, false /*requireMmapSize*/);
}
sp<ProcessState> ProcessState::selfOrNull() {
return init(0, false /*requireMmapSize*/);
}
sp<ProcessState> ProcessState::initWithMmapSize(size_t mmapSize) {
return init(mmapSize, true /*requireMmapSize*/);
}
sp<ProcessState> ProcessState::init(size_t mmapSize, bool requireMmapSize) {
[[clang::no_destroy]] static sp<ProcessState> gProcess;
[[clang::no_destroy]] static std::mutex gProcessMutex;
if (mmapSize == 0) {
std::lock_guard<std::mutex> l(gProcessMutex);
return gProcess;
}
[[clang::no_destroy]] static std::once_flag gProcessOnce;
std::call_once(gProcessOnce, [&](){
std::lock_guard<std::mutex> l(gProcessMutex);
gProcess = new ProcessState(mmapSize);
});
if (requireMmapSize) {
LOG_ALWAYS_FATAL_IF(mmapSize != gProcess->getMmapSize(),
"ProcessState already initialized with a different mmap size.");
}
return gProcess;
}
void ProcessState::startThreadPool()
{
if (!isHwbinderSupportedBlocking()) {
ALOGW("HwBinder is not supported on this device but this process is calling startThreadPool");
}
AutoMutex _l(mLock);
if (!mThreadPoolStarted) {
mThreadPoolStarted = true;
if (mSpawnThreadOnStart) {
spawnPooledThread(true);
}
}
}
sp<IBinder> ProcessState::getContextObject(const sp<IBinder>& /*caller*/)
{
return getStrongProxyForHandle(0);
}
void ProcessState::becomeContextManager()
{
AutoMutex _l(mLock);
flat_binder_object obj {
.flags = FLAT_BINDER_FLAG_TXN_SECURITY_CTX,
};
status_t result = ioctl(mDriverFD, BINDER_SET_CONTEXT_MGR_EXT, &obj);
// fallback to original method
if (result != 0) {
android_errorWriteLog(0x534e4554, "121035042");
int unused = 0;
result = ioctl(mDriverFD, BINDER_SET_CONTEXT_MGR, &unused);
}
if (result == -1) {
ALOGE("Binder ioctl to become context manager failed: %s\n", strerror(errno));
}
}
// Get references to userspace objects held by the kernel binder driver
// Writes up to count elements into buf, and returns the total number
// of references the kernel has, which may be larger than count.
// buf may be NULL if count is 0. The pointers returned by this method
// should only be used for debugging and not dereferenced, they may
// already be invalid.
ssize_t ProcessState::getKernelReferences(size_t buf_count, uintptr_t* buf) {
binder_node_debug_info info = {};
uintptr_t* end = buf ? buf + buf_count : nullptr;
size_t count = 0;
do {
status_t result = ioctl(mDriverFD, BINDER_GET_NODE_DEBUG_INFO, &info);
if (result < 0) {
return -1;
}
if (info.ptr != 0) {
if (buf && buf < end) *buf++ = info.ptr;
count++;
if (buf && buf < end) *buf++ = info.cookie;
count++;
}
} while (info.ptr != 0);
return count;
}
// Queries the driver for the current strong reference count of the node
// that the handle points to. Can only be used by the servicemanager.
//
// Returns -1 in case of failure, otherwise the strong reference count.
ssize_t ProcessState::getStrongRefCountForNodeByHandle(int32_t handle) {
binder_node_info_for_ref info;
memset(&info, 0, sizeof(binder_node_info_for_ref));
info.handle = handle;
status_t result = ioctl(mDriverFD, BINDER_GET_NODE_INFO_FOR_REF, &info);
if (result != OK) {
static bool logged = false;
if (!logged) {
ALOGW("Kernel does not support BINDER_GET_NODE_INFO_FOR_REF.");
logged = true;
}
return -1;
}
return info.strong_count;
}
size_t ProcessState::getMmapSize() {
return mMmapSize;
}
void ProcessState::setCallRestriction(CallRestriction restriction) {
LOG_ALWAYS_FATAL_IF(IPCThreadState::selfOrNull() != nullptr,
"Call restrictions must be set before the threadpool is started.");
mCallRestriction = restriction;
}
ProcessState::handle_entry* ProcessState::lookupHandleLocked(int32_t handle)
{
const size_t N=mHandleToObject.size();
if (N <= (size_t)handle) {
handle_entry e;
e.binder = nullptr;
e.refs = nullptr;
status_t err = mHandleToObject.insertAt(e, N, handle+1-N);
if (err < NO_ERROR) return nullptr;
}
return &mHandleToObject.editItemAt(handle);
}
sp<IBinder> ProcessState::getStrongProxyForHandle(int32_t handle)
{
sp<IBinder> result;
AutoMutex _l(mLock);
handle_entry* e = lookupHandleLocked(handle);
if (e != nullptr) {
// We need to create a new BpHwBinder if there isn't currently one, OR we
// are unable to acquire a weak reference on this current one. See comment
// in getWeakProxyForHandle() for more info about this.
IBinder* b = e->binder;
if (b == nullptr || !e->refs->attemptIncWeak(this)) {
b = new BpHwBinder(handle);
e->binder = b;
if (b) e->refs = b->getWeakRefs();
result = b;
} else {
// This little bit of nastyness is to allow us to add a primary
// reference to the remote proxy when this team doesn't have one
// but another team is sending the handle to us.
result.force_set(b);
e->refs->decWeak(this);
}
}
return result;
}
wp<IBinder> ProcessState::getWeakProxyForHandle(int32_t handle)
{
wp<IBinder> result;
AutoMutex _l(mLock);
handle_entry* e = lookupHandleLocked(handle);
if (e != nullptr) {
// We need to create a new BpHwBinder if there isn't currently one, OR we
// are unable to acquire a weak reference on this current one. The
// attemptIncWeak() is safe because we know the BpHwBinder destructor will always
// call expungeHandle(), which acquires the same lock we are holding now.
// We need to do this because there is a race condition between someone
// releasing a reference on this BpHwBinder, and a new reference on its handle
// arriving from the driver.
IBinder* b = e->binder;
if (b == nullptr || !e->refs->attemptIncWeak(this)) {
b = new BpHwBinder(handle);
result = b;
e->binder = b;
if (b) e->refs = b->getWeakRefs();
} else {
result = b;
e->refs->decWeak(this);
}
}
return result;
}
void ProcessState::expungeHandle(int32_t handle, IBinder* binder)
{
AutoMutex _l(mLock);
handle_entry* e = lookupHandleLocked(handle);
// This handle may have already been replaced with a new BpHwBinder
// (if someone failed the AttemptIncWeak() above); we don't want
// to overwrite it.
if (e && e->binder == binder) e->binder = nullptr;
}
String8 ProcessState::makeBinderThreadName() {
int32_t s = android_atomic_add(1, &mThreadPoolSeq);
pid_t pid = getpid();
String8 name;
name.appendFormat("HwBinder:%d_%X", pid, s);
return name;
}
void ProcessState::spawnPooledThread(bool isMain)
{
if (mThreadPoolStarted) {
String8 name = makeBinderThreadName();
ALOGV("Spawning new pooled thread, name=%s\n", name.c_str());
sp<Thread> t = new PoolThread(isMain);
t->run(name.c_str());
}
}
status_t ProcessState::setThreadPoolConfiguration(size_t maxThreads, bool callerJoinsPool) {
LOG_ALWAYS_FATAL_IF(mThreadPoolStarted && maxThreads < mMaxThreads,
"Binder threadpool cannot be shrunk after starting");
// if the caller joins the pool, then there will be one thread which is impossible.
LOG_ALWAYS_FATAL_IF(maxThreads == 0 && callerJoinsPool,
"Binder threadpool must have a minimum of one thread if caller joins pool.");
if (!isHwbinderSupportedBlocking()) {
ALOGW("HwBinder is not supported on this device but this process is calling setThreadPoolConfiguration");
}
size_t threadsToAllocate = maxThreads;
// If the caller is going to join the pool it will contribute one thread to the threadpool.
// This is part of the API's contract.
if (callerJoinsPool) threadsToAllocate--;
// If we can, spawn one thread from userspace when the threadpool is started. This ensures
// that there is always a thread available to start more threads as soon as the threadpool
// is started.
bool spawnThreadOnStart = threadsToAllocate > 0;
if (spawnThreadOnStart) threadsToAllocate--;
// the BINDER_SET_MAX_THREADS ioctl really tells the kernel how many threads
// it's allowed to spawn, *in addition* to any threads we may have already
// spawned locally.
size_t kernelMaxThreads = threadsToAllocate;
AutoMutex _l(mLock);
if (ioctl(mDriverFD, BINDER_SET_MAX_THREADS, &kernelMaxThreads) == -1) {
ALOGE("Binder ioctl to set max threads failed: %s", strerror(errno));
return -errno;
}
mMaxThreads = maxThreads;
mSpawnThreadOnStart = spawnThreadOnStart;
return NO_ERROR;
}
status_t ProcessState::enableOnewaySpamDetection(bool enable) {
uint32_t enableDetection = enable ? 1 : 0;
if (ioctl(mDriverFD, BINDER_ENABLE_ONEWAY_SPAM_DETECTION, &enableDetection) == -1) {
ALOGI("Binder ioctl to enable oneway spam detection failed: %s", strerror(errno));
return -errno;
}
return NO_ERROR;
}
size_t ProcessState::getMaxThreads() {
return mMaxThreads;
}
void ProcessState::giveThreadPoolName() {
androidSetThreadName( makeBinderThreadName().c_str() );
}
static int open_driver()
{
int fd = open("/dev/hwbinder", O_RDWR | O_CLOEXEC);
if (fd >= 0) {
int vers = 0;
status_t result = ioctl(fd, BINDER_VERSION, &vers);
if (result == -1) {
ALOGE("Binder ioctl to obtain version failed: %s", strerror(errno));
close(fd);
fd = -1;
}
if (result != 0 || vers != BINDER_CURRENT_PROTOCOL_VERSION) {
ALOGE("Binder driver protocol(%d) does not match user space protocol(%d)!", vers, BINDER_CURRENT_PROTOCOL_VERSION);
close(fd);
fd = -1;
}
size_t maxThreads = DEFAULT_MAX_BINDER_THREADS;
result = ioctl(fd, BINDER_SET_MAX_THREADS, &maxThreads);
if (result == -1) {
ALOGE("Binder ioctl to set max threads failed: %s", strerror(errno));
}
uint32_t enable = DEFAULT_ENABLE_ONEWAY_SPAM_DETECTION;
result = ioctl(fd, BINDER_ENABLE_ONEWAY_SPAM_DETECTION, &enable);
if (result == -1) {
ALOGV("Binder ioctl to enable oneway spam detection failed: %s", strerror(errno));
}
} else {
ALOGW("Opening '/dev/hwbinder' failed: %s\n", strerror(errno));
}
return fd;
}
ProcessState::ProcessState(size_t mmapSize)
: mDriverFD(open_driver())
, mVMStart(MAP_FAILED)
, mThreadCountLock(PTHREAD_MUTEX_INITIALIZER)
, mExecutingThreadsCount(0)
, mMaxThreads(DEFAULT_MAX_BINDER_THREADS)
, mStarvationStartTimeMs(0)
, mThreadPoolStarted(false)
, mSpawnThreadOnStart(true)
, mThreadPoolSeq(1)
, mMmapSize(mmapSize)
, mCallRestriction(CallRestriction::NONE)
{
if (mDriverFD >= 0) {
// mmap the binder, providing a chunk of virtual address space to receive transactions.
mVMStart = mmap(nullptr, mMmapSize, PROT_READ, MAP_PRIVATE | MAP_NORESERVE, mDriverFD, 0);
if (mVMStart == MAP_FAILED) {
// *sigh*
ALOGE("Mmapping /dev/hwbinder failed: %s\n", strerror(errno));
close(mDriverFD);
mDriverFD = -1;
}
}
#ifdef __ANDROID__
LOG_ALWAYS_FATAL_IF(mDriverFD < 0, "Binder driver could not be opened. Terminating.");
#endif
}
ProcessState::~ProcessState()
{
if (mDriverFD >= 0) {
if (mVMStart != MAP_FAILED) {
munmap(mVMStart, mMmapSize);
}
close(mDriverFD);
}
mDriverFD = -1;
}
} // namespace hardware
} // namespace android