Merge "Native Side of Binder Proxy Tracking by Uid"
diff --git a/libs/binder/BpBinder.cpp b/libs/binder/BpBinder.cpp
index 49ff460..75ad5d5 100644
--- a/libs/binder/BpBinder.cpp
+++ b/libs/binder/BpBinder.cpp
@@ -21,6 +21,7 @@
#include <binder/IPCThreadState.h>
#include <binder/IResultReceiver.h>
+#include <cutils/compiler.h>
#include <utils/Log.h>
#include <stdio.h>
@@ -32,6 +33,23 @@
// ---------------------------------------------------------------------------
+Mutex BpBinder::sTrackingLock;
+std::unordered_map<int32_t,uint32_t> BpBinder::sTrackingMap;
+int BpBinder::sNumTrackedUids = 0;
+std::atomic_bool BpBinder::sCountByUidEnabled(false);
+binder_proxy_limit_callback BpBinder::sLimitCallback;
+bool BpBinder::sBinderProxyThrottleCreate = false;
+
+// Arbitrarily high value that probably distinguishes a bad behaving app
+uint32_t BpBinder::sBinderProxyCountHighWatermark = 2500;
+// Another arbitrary value a binder count needs to drop below before another callback will be called
+uint32_t BpBinder::sBinderProxyCountLowWatermark = 2000;
+
+enum {
+ CALLBACK_TRIGGERED_MASK = 0x80000000, // A flag denoting that the callback has been called
+ COUNTING_VALUE_MASK = 0x7FFFFFFF, // A mask of the remaining bits for the count value
+};
+
BpBinder::ObjectManager::ObjectManager()
{
}
@@ -87,11 +105,47 @@
// ---------------------------------------------------------------------------
-BpBinder::BpBinder(int32_t handle)
+
+BpBinder* BpBinder::create(int32_t handle) {
+ int32_t trackedUid = -1;
+ if (sCountByUidEnabled) {
+ BpBinder* out;
+ trackedUid = IPCThreadState::self()->getCallingUid();
+ AutoMutex _l(sTrackingLock);
+ if ((sTrackingMap[trackedUid] & COUNTING_VALUE_MASK) >= sBinderProxyCountHighWatermark) {
+ ALOGE("Too many binder proxy objects sent to uid %d from uid %d (over %d proxies held)",
+ getuid(), trackedUid, sBinderProxyCountHighWatermark);
+
+ if (sBinderProxyThrottleCreate) {
+ ALOGE("Returning Null Binder Proxy Object to uid %d", trackedUid);
+ out = nullptr;
+ } else {
+ // increment and construct here in case callback has an async kill causing a race
+ sTrackingMap[trackedUid]++;
+ out = new BpBinder(handle, trackedUid);
+ }
+
+ if (sLimitCallback && !(sTrackingMap[trackedUid] & CALLBACK_TRIGGERED_MASK)) {
+ sTrackingMap[trackedUid] |= CALLBACK_TRIGGERED_MASK;
+ sLimitCallback(trackedUid);
+ }
+ } else {
+ sTrackingMap[trackedUid]++;
+ out = new BpBinder(handle, trackedUid);
+ }
+
+ return out;
+ } else {
+ return new BpBinder(handle, trackedUid);
+ }
+}
+
+BpBinder::BpBinder(int32_t handle, int32_t trackedUid)
: mHandle(handle)
, mAlive(1)
, mObitsSent(0)
, mObituaries(nullptr)
+ , mTrackedUid(trackedUid)
{
ALOGV("Creating BpBinder %p handle %d\n", this, mHandle);
@@ -315,6 +369,24 @@
IPCThreadState* ipc = IPCThreadState::self();
+ if (mTrackedUid >= 0) {
+ AutoMutex _l(sTrackingLock);
+ if (CC_UNLIKELY(sTrackingMap[mTrackedUid] == 0)) {
+ ALOGE("Unexpected Binder Proxy tracking decrement in %p handle %d\n", this, mHandle);
+ } else {
+ if (CC_UNLIKELY(
+ (sTrackingMap[mTrackedUid] & CALLBACK_TRIGGERED_MASK) &&
+ ((sTrackingMap[mTrackedUid] & COUNTING_VALUE_MASK) <= sBinderProxyCountLowWatermark)
+ )) {
+ // Clear the Callback Triggered bit when crossing below the low watermark
+ sTrackingMap[mTrackedUid] &= ~CALLBACK_TRIGGERED_MASK;
+ }
+ if (--sTrackingMap[mTrackedUid] == 0) {
+ sTrackingMap.erase(mTrackedUid);
+ }
+ }
+ }
+
mLock.lock();
Vector<Obituary>* obits = mObituaries;
if(obits != nullptr) {
@@ -360,6 +432,42 @@
return ipc ? ipc->attemptIncStrongHandle(mHandle) == NO_ERROR : false;
}
+uint32_t BpBinder::getBinderProxyCount(uint32_t uid)
+{
+ AutoMutex _l(sTrackingLock);
+ auto it = sTrackingMap.find(uid);
+ if (it != sTrackingMap.end()) {
+ return it->second & COUNTING_VALUE_MASK;
+ }
+ return 0;
+}
+
+void BpBinder::getCountByUid(Vector<uint32_t>& uids, Vector<uint32_t>& counts)
+{
+ AutoMutex _l(sTrackingLock);
+ uids.setCapacity(sTrackingMap.size());
+ counts.setCapacity(sTrackingMap.size());
+ for (const auto& it : sTrackingMap) {
+ uids.push_back(it.first);
+ counts.push_back(it.second & COUNTING_VALUE_MASK);
+ }
+}
+
+void BpBinder::enableCountByUid() { sCountByUidEnabled.store(true); }
+void BpBinder::disableCountByUid() { sCountByUidEnabled.store(false); }
+void BpBinder::setCountByUidEnabled(bool enable) { sCountByUidEnabled.store(enable); }
+
+void BpBinder::setLimitCallback(binder_proxy_limit_callback cb) {
+ AutoMutex _l(sTrackingLock);
+ sLimitCallback = cb;
+}
+
+void BpBinder::setBinderProxyCountWatermarks(int high, int low) {
+ AutoMutex _l(sTrackingLock);
+ sBinderProxyCountHighWatermark = high;
+ sBinderProxyCountLowWatermark = low;
+}
+
// ---------------------------------------------------------------------------
}; // namespace android
diff --git a/libs/binder/ProcessState.cpp b/libs/binder/ProcessState.cpp
index c8cdb77..53f8ddd 100644
--- a/libs/binder/ProcessState.cpp
+++ b/libs/binder/ProcessState.cpp
@@ -288,7 +288,7 @@
return nullptr;
}
- b = new BpBinder(handle);
+ b = BpBinder::create(handle);
e->binder = b;
if (b) e->refs = b->getWeakRefs();
result = b;
@@ -322,7 +322,7 @@
// arriving from the driver.
IBinder* b = e->binder;
if (b == nullptr || !e->refs->attemptIncWeak(this)) {
- b = new BpBinder(handle);
+ b = BpBinder::create(handle);
result = b;
e->binder = b;
if (b) e->refs = b->getWeakRefs();
diff --git a/libs/binder/include/binder/BpBinder.h b/libs/binder/include/binder/BpBinder.h
index 7ef93aa..8bd297b 100644
--- a/libs/binder/include/binder/BpBinder.h
+++ b/libs/binder/include/binder/BpBinder.h
@@ -19,15 +19,20 @@
#include <binder/IBinder.h>
#include <utils/KeyedVector.h>
+#include <utils/Mutex.h>
#include <utils/threads.h>
+#include <unordered_map>
+
// ---------------------------------------------------------------------------
namespace android {
+using binder_proxy_limit_callback = void(*)(int);
+
class BpBinder : public IBinder
{
public:
- BpBinder(int32_t handle);
+ static BpBinder* create(int32_t handle);
inline int32_t handle() const { return mHandle; }
@@ -61,6 +66,14 @@
status_t setConstantData(const void* data, size_t size);
void sendObituary();
+ static uint32_t getBinderProxyCount(uint32_t uid);
+ static void getCountByUid(Vector<uint32_t>& uids, Vector<uint32_t>& counts);
+ static void enableCountByUid();
+ static void disableCountByUid();
+ static void setCountByUidEnabled(bool enable);
+ static void setLimitCallback(binder_proxy_limit_callback cb);
+ static void setBinderProxyCountWatermarks(int high, int low);
+
class ObjectManager
{
public:
@@ -91,6 +104,7 @@
};
protected:
+ BpBinder(int32_t handle,int32_t trackedUid);
virtual ~BpBinder();
virtual void onFirstRef();
virtual void onLastStrongRef(const void* id);
@@ -115,6 +129,16 @@
ObjectManager mObjects;
Parcel* mConstantData;
mutable String16 mDescriptorCache;
+ int32_t mTrackedUid;
+
+ static Mutex sTrackingLock;
+ static std::unordered_map<int32_t,uint32_t> sTrackingMap;
+ static int sNumTrackedUids;
+ static std::atomic_bool sCountByUidEnabled;
+ static binder_proxy_limit_callback sLimitCallback;
+ static uint32_t sBinderProxyCountHighWatermark;
+ static uint32_t sBinderProxyCountLowWatermark;
+ static bool sBinderProxyThrottleCreate;
};
}; // namespace android
