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      1 /*
      2  * Copyright (C) 2006 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 #define LOG_TAG "JavaBinder"
     18 //#define LOG_NDEBUG 0
     19 
     20 #include "android_os_Parcel.h"
     21 #include "android_util_Binder.h"
     22 
     23 #include <atomic>
     24 #include <fcntl.h>
     25 #include <inttypes.h>
     26 #include <stdio.h>
     27 #include <sys/stat.h>
     28 #include <sys/types.h>
     29 #include <unistd.h>
     30 
     31 #include <android-base/stringprintf.h>
     32 #include <binder/IInterface.h>
     33 #include <binder/IServiceManager.h>
     34 #include <binder/IPCThreadState.h>
     35 #include <binder/Parcel.h>
     36 #include <binder/BpBinder.h>
     37 #include <binder/ProcessState.h>
     38 #include <cutils/atomic.h>
     39 #include <log/log.h>
     40 #include <utils/KeyedVector.h>
     41 #include <utils/List.h>
     42 #include <utils/Log.h>
     43 #include <utils/String8.h>
     44 #include <utils/SystemClock.h>
     45 #include <utils/threads.h>
     46 
     47 #include <nativehelper/JNIHelp.h>
     48 #include <nativehelper/ScopedLocalRef.h>
     49 #include <nativehelper/ScopedUtfChars.h>
     50 
     51 #include "core_jni_helpers.h"
     52 
     53 //#undef ALOGV
     54 //#define ALOGV(...) fprintf(stderr, __VA_ARGS__)
     55 
     56 #define DEBUG_DEATH 0
     57 #if DEBUG_DEATH
     58 #define LOGDEATH ALOGD
     59 #else
     60 #define LOGDEATH ALOGV
     61 #endif
     62 
     63 using namespace android;
     64 
     65 // ----------------------------------------------------------------------------
     66 
     67 static struct bindernative_offsets_t
     68 {
     69     // Class state.
     70     jclass mClass;
     71     jmethodID mExecTransact;
     72 
     73     // Object state.
     74     jfieldID mObject;
     75 
     76 } gBinderOffsets;
     77 
     78 // ----------------------------------------------------------------------------
     79 
     80 static struct binderinternal_offsets_t
     81 {
     82     // Class state.
     83     jclass mClass;
     84     jmethodID mForceGc;
     85     jmethodID mProxyLimitCallback;
     86 
     87 } gBinderInternalOffsets;
     88 
     89 static struct sparseintarray_offsets_t
     90 {
     91     jclass classObject;
     92     jmethodID constructor;
     93     jmethodID put;
     94 } gSparseIntArrayOffsets;
     95 
     96 // ----------------------------------------------------------------------------
     97 
     98 static struct error_offsets_t
     99 {
    100     jclass mClass;
    101 } gErrorOffsets;
    102 
    103 // ----------------------------------------------------------------------------
    104 
    105 static struct binderproxy_offsets_t
    106 {
    107     // Class state.
    108     jclass mClass;
    109     jmethodID mGetInstance;
    110     jmethodID mSendDeathNotice;
    111     jmethodID mDumpProxyDebugInfo;
    112 
    113     // Object state.
    114     jfieldID mNativeData;  // Field holds native pointer to BinderProxyNativeData.
    115 } gBinderProxyOffsets;
    116 
    117 static struct class_offsets_t
    118 {
    119     jmethodID mGetName;
    120 } gClassOffsets;
    121 
    122 // ----------------------------------------------------------------------------
    123 
    124 static struct log_offsets_t
    125 {
    126     // Class state.
    127     jclass mClass;
    128     jmethodID mLogE;
    129 } gLogOffsets;
    130 
    131 static struct parcel_file_descriptor_offsets_t
    132 {
    133     jclass mClass;
    134     jmethodID mConstructor;
    135 } gParcelFileDescriptorOffsets;
    136 
    137 static struct strict_mode_callback_offsets_t
    138 {
    139     jclass mClass;
    140     jmethodID mCallback;
    141 } gStrictModeCallbackOffsets;
    142 
    143 static struct thread_dispatch_offsets_t
    144 {
    145     // Class state.
    146     jclass mClass;
    147     jmethodID mDispatchUncaughtException;
    148     jmethodID mCurrentThread;
    149 } gThreadDispatchOffsets;
    150 
    151 // ****************************************************************************
    152 // ****************************************************************************
    153 // ****************************************************************************
    154 
    155 static constexpr int32_t PROXY_WARN_INTERVAL = 5000;
    156 static constexpr uint32_t GC_INTERVAL = 1000;
    157 
    158 // Protected by gProxyLock. We warn if this gets too large.
    159 static int32_t gNumProxies = 0;
    160 static int32_t gProxiesWarned = 0;
    161 
    162 // Number of GlobalRefs held by JavaBBinders.
    163 static std::atomic<uint32_t> gNumLocalRefsCreated(0);
    164 static std::atomic<uint32_t> gNumLocalRefsDeleted(0);
    165 // Number of GlobalRefs held by JavaDeathRecipients.
    166 static std::atomic<uint32_t> gNumDeathRefsCreated(0);
    167 static std::atomic<uint32_t> gNumDeathRefsDeleted(0);
    168 
    169 // We collected after creating this many refs.
    170 static std::atomic<uint32_t> gCollectedAtRefs(0);
    171 
    172 // Garbage collect if we've allocated at least GC_INTERVAL refs since the last time.
    173 // TODO: Consider removing this completely. We should no longer be generating GlobalRefs
    174 // that are reclaimed as a result of GC action.
    175 __attribute__((no_sanitize("unsigned-integer-overflow")))
    176 static void gcIfManyNewRefs(JNIEnv* env)
    177 {
    178     uint32_t totalRefs = gNumLocalRefsCreated.load(std::memory_order_relaxed)
    179             + gNumDeathRefsCreated.load(std::memory_order_relaxed);
    180     uint32_t collectedAtRefs = gCollectedAtRefs.load(memory_order_relaxed);
    181     // A bound on the number of threads that can have incremented gNum...RefsCreated before the
    182     // following check is executed. Effectively a bound on #threads. Almost any value will do.
    183     static constexpr uint32_t MAX_RACING = 100000;
    184 
    185     if (totalRefs - (collectedAtRefs + GC_INTERVAL) /* modular arithmetic! */ < MAX_RACING) {
    186         // Recently passed next GC interval.
    187         if (gCollectedAtRefs.compare_exchange_strong(collectedAtRefs,
    188                 collectedAtRefs + GC_INTERVAL, std::memory_order_relaxed)) {
    189             ALOGV("Binder forcing GC at %u created refs", totalRefs);
    190             env->CallStaticVoidMethod(gBinderInternalOffsets.mClass,
    191                     gBinderInternalOffsets.mForceGc);
    192         }  // otherwise somebody else beat us to it.
    193     } else {
    194         ALOGV("Now have %d binder ops", totalRefs - collectedAtRefs);
    195     }
    196 }
    197 
    198 static JavaVM* jnienv_to_javavm(JNIEnv* env)
    199 {
    200     JavaVM* vm;
    201     return env->GetJavaVM(&vm) >= 0 ? vm : NULL;
    202 }
    203 
    204 static JNIEnv* javavm_to_jnienv(JavaVM* vm)
    205 {
    206     JNIEnv* env;
    207     return vm->GetEnv((void **)&env, JNI_VERSION_1_4) >= 0 ? env : NULL;
    208 }
    209 
    210 // Report a java.lang.Error (or subclass). This will terminate the runtime by
    211 // calling FatalError with a message derived from the given error.
    212 static void report_java_lang_error_fatal_error(JNIEnv* env, jthrowable error,
    213         const char* msg)
    214 {
    215     // Report an error: reraise the exception and ask the runtime to abort.
    216 
    217     // Try to get the exception string. Sometimes logcat isn't available,
    218     // so try to add it to the abort message.
    219     std::string exc_msg = "(Unknown exception message)";
    220     {
    221         ScopedLocalRef<jclass> exc_class(env, env->GetObjectClass(error));
    222         jmethodID method_id = env->GetMethodID(exc_class.get(), "toString",
    223                 "()Ljava/lang/String;");
    224         ScopedLocalRef<jstring> jstr(
    225                 env,
    226                 reinterpret_cast<jstring>(
    227                         env->CallObjectMethod(error, method_id)));
    228         env->ExceptionClear();  // Just for good measure.
    229         if (jstr.get() != nullptr) {
    230             ScopedUtfChars jstr_utf(env, jstr.get());
    231             if (jstr_utf.c_str() != nullptr) {
    232                 exc_msg = jstr_utf.c_str();
    233             } else {
    234                 env->ExceptionClear();
    235             }
    236         }
    237     }
    238 
    239     env->Throw(error);
    240     ALOGE("java.lang.Error thrown during binder transaction (stack trace follows) : ");
    241     env->ExceptionDescribe();
    242 
    243     std::string error_msg = base::StringPrintf(
    244             "java.lang.Error thrown during binder transaction: %s",
    245             exc_msg.c_str());
    246     env->FatalError(error_msg.c_str());
    247 }
    248 
    249 // Report a java.lang.Error (or subclass). This will terminate the runtime, either by
    250 // the uncaught exception handler, or explicitly by calling
    251 // report_java_lang_error_fatal_error.
    252 static void report_java_lang_error(JNIEnv* env, jthrowable error, const char* msg)
    253 {
    254     // Try to run the uncaught exception machinery.
    255     jobject thread = env->CallStaticObjectMethod(gThreadDispatchOffsets.mClass,
    256             gThreadDispatchOffsets.mCurrentThread);
    257     if (thread != nullptr) {
    258         env->CallVoidMethod(thread, gThreadDispatchOffsets.mDispatchUncaughtException,
    259                 error);
    260         // Should not return here, unless more errors occured.
    261     }
    262     // Some error occurred that meant that either dispatchUncaughtException could not be
    263     // called or that it had an error itself (as this should be unreachable under normal
    264     // conditions). As the binder code cannot handle Errors, attempt to log the error and
    265     // abort.
    266     env->ExceptionClear();
    267     report_java_lang_error_fatal_error(env, error, msg);
    268 }
    269 
    270 static void report_exception(JNIEnv* env, jthrowable excep, const char* msg)
    271 {
    272     env->ExceptionClear();
    273 
    274     ScopedLocalRef<jstring> tagstr(env, env->NewStringUTF(LOG_TAG));
    275     ScopedLocalRef<jstring> msgstr(env);
    276     if (tagstr != nullptr) {
    277         msgstr.reset(env->NewStringUTF(msg));
    278     }
    279 
    280     if ((tagstr != nullptr) && (msgstr != nullptr)) {
    281         env->CallStaticIntMethod(gLogOffsets.mClass, gLogOffsets.mLogE,
    282                 tagstr.get(), msgstr.get(), excep);
    283         if (env->ExceptionCheck()) {
    284             // Attempting to log the failure has failed.
    285             ALOGW("Failed trying to log exception, msg='%s'\n", msg);
    286             env->ExceptionClear();
    287         }
    288     } else {
    289         env->ExceptionClear();      /* assume exception (OOM?) was thrown */
    290         ALOGE("Unable to call Log.e()\n");
    291         ALOGE("%s", msg);
    292     }
    293 
    294     if (env->IsInstanceOf(excep, gErrorOffsets.mClass)) {
    295         report_java_lang_error(env, excep, msg);
    296     }
    297 }
    298 
    299 class JavaBBinderHolder;
    300 
    301 class JavaBBinder : public BBinder
    302 {
    303 public:
    304     JavaBBinder(JNIEnv* env, jobject /* Java Binder */ object)
    305         : mVM(jnienv_to_javavm(env)), mObject(env->NewGlobalRef(object))
    306     {
    307         ALOGV("Creating JavaBBinder %p\n", this);
    308         gNumLocalRefsCreated.fetch_add(1, std::memory_order_relaxed);
    309         gcIfManyNewRefs(env);
    310     }
    311 
    312     bool    checkSubclass(const void* subclassID) const
    313     {
    314         return subclassID == &gBinderOffsets;
    315     }
    316 
    317     jobject object() const
    318     {
    319         return mObject;
    320     }
    321 
    322 protected:
    323     virtual ~JavaBBinder()
    324     {
    325         ALOGV("Destroying JavaBBinder %p\n", this);
    326         gNumLocalRefsDeleted.fetch_add(1, memory_order_relaxed);
    327         JNIEnv* env = javavm_to_jnienv(mVM);
    328         env->DeleteGlobalRef(mObject);
    329     }
    330 
    331     virtual status_t onTransact(
    332         uint32_t code, const Parcel& data, Parcel* reply, uint32_t flags = 0)
    333     {
    334         JNIEnv* env = javavm_to_jnienv(mVM);
    335 
    336         ALOGV("onTransact() on %p calling object %p in env %p vm %p\n", this, mObject, env, mVM);
    337 
    338         IPCThreadState* thread_state = IPCThreadState::self();
    339         const int32_t strict_policy_before = thread_state->getStrictModePolicy();
    340 
    341         //printf("Transact from %p to Java code sending: ", this);
    342         //data.print();
    343         //printf("\n");
    344         jboolean res = env->CallBooleanMethod(mObject, gBinderOffsets.mExecTransact,
    345             code, reinterpret_cast<jlong>(&data), reinterpret_cast<jlong>(reply), flags);
    346 
    347         if (env->ExceptionCheck()) {
    348             ScopedLocalRef<jthrowable> excep(env, env->ExceptionOccurred());
    349             report_exception(env, excep.get(),
    350                 "*** Uncaught remote exception!  "
    351                 "(Exceptions are not yet supported across processes.)");
    352             res = JNI_FALSE;
    353         }
    354 
    355         // Check if the strict mode state changed while processing the
    356         // call.  The Binder state will be restored by the underlying
    357         // Binder system in IPCThreadState, however we need to take care
    358         // of the parallel Java state as well.
    359         if (thread_state->getStrictModePolicy() != strict_policy_before) {
    360             set_dalvik_blockguard_policy(env, strict_policy_before);
    361         }
    362 
    363         if (env->ExceptionCheck()) {
    364             ScopedLocalRef<jthrowable> excep(env, env->ExceptionOccurred());
    365             report_exception(env, excep.get(),
    366                 "*** Uncaught exception in onBinderStrictModePolicyChange");
    367         }
    368 
    369         // Need to always call through the native implementation of
    370         // SYSPROPS_TRANSACTION.
    371         if (code == SYSPROPS_TRANSACTION) {
    372             BBinder::onTransact(code, data, reply, flags);
    373         }
    374 
    375         //aout << "onTransact to Java code; result=" << res << endl
    376         //    << "Transact from " << this << " to Java code returning "
    377         //    << reply << ": " << *reply << endl;
    378         return res != JNI_FALSE ? NO_ERROR : UNKNOWN_TRANSACTION;
    379     }
    380 
    381     virtual status_t dump(int fd, const Vector<String16>& args)
    382     {
    383         return 0;
    384     }
    385 
    386 private:
    387     JavaVM* const   mVM;
    388     jobject const   mObject;  // GlobalRef to Java Binder
    389 };
    390 
    391 // ----------------------------------------------------------------------------
    392 
    393 class JavaBBinderHolder
    394 {
    395 public:
    396     sp<JavaBBinder> get(JNIEnv* env, jobject obj)
    397     {
    398         AutoMutex _l(mLock);
    399         sp<JavaBBinder> b = mBinder.promote();
    400         if (b == NULL) {
    401             b = new JavaBBinder(env, obj);
    402             mBinder = b;
    403             ALOGV("Creating JavaBinder %p (refs %p) for Object %p, weakCount=%" PRId32 "\n",
    404                  b.get(), b->getWeakRefs(), obj, b->getWeakRefs()->getWeakCount());
    405         }
    406 
    407         return b;
    408     }
    409 
    410     sp<JavaBBinder> getExisting()
    411     {
    412         AutoMutex _l(mLock);
    413         return mBinder.promote();
    414     }
    415 
    416 private:
    417     Mutex           mLock;
    418     wp<JavaBBinder> mBinder;
    419 };
    420 
    421 // ----------------------------------------------------------------------------
    422 
    423 // Per-IBinder death recipient bookkeeping.  This is how we reconcile local jobject
    424 // death recipient references passed in through JNI with the permanent corresponding
    425 // JavaDeathRecipient objects.
    426 
    427 class JavaDeathRecipient;
    428 
    429 class DeathRecipientList : public RefBase {
    430     List< sp<JavaDeathRecipient> > mList;
    431     Mutex mLock;
    432 
    433 public:
    434     DeathRecipientList();
    435     ~DeathRecipientList();
    436 
    437     void add(const sp<JavaDeathRecipient>& recipient);
    438     void remove(const sp<JavaDeathRecipient>& recipient);
    439     sp<JavaDeathRecipient> find(jobject recipient);
    440 
    441     Mutex& lock();  // Use with care; specifically for mutual exclusion during binder death
    442 };
    443 
    444 // ----------------------------------------------------------------------------
    445 
    446 class JavaDeathRecipient : public IBinder::DeathRecipient
    447 {
    448 public:
    449     JavaDeathRecipient(JNIEnv* env, jobject object, const sp<DeathRecipientList>& list)
    450         : mVM(jnienv_to_javavm(env)), mObject(env->NewGlobalRef(object)),
    451           mObjectWeak(NULL), mList(list)
    452     {
    453         // These objects manage their own lifetimes so are responsible for final bookkeeping.
    454         // The list holds a strong reference to this object.
    455         LOGDEATH("Adding JDR %p to DRL %p", this, list.get());
    456         list->add(this);
    457 
    458         gNumDeathRefsCreated.fetch_add(1, std::memory_order_relaxed);
    459         gcIfManyNewRefs(env);
    460     }
    461 
    462     void binderDied(const wp<IBinder>& who)
    463     {
    464         LOGDEATH("Receiving binderDied() on JavaDeathRecipient %p\n", this);
    465         if (mObject != NULL) {
    466             JNIEnv* env = javavm_to_jnienv(mVM);
    467 
    468             env->CallStaticVoidMethod(gBinderProxyOffsets.mClass,
    469                     gBinderProxyOffsets.mSendDeathNotice, mObject);
    470             if (env->ExceptionCheck()) {
    471                 jthrowable excep = env->ExceptionOccurred();
    472                 report_exception(env, excep,
    473                         "*** Uncaught exception returned from death notification!");
    474             }
    475 
    476             // Serialize with our containing DeathRecipientList so that we can't
    477             // delete the global ref on mObject while the list is being iterated.
    478             sp<DeathRecipientList> list = mList.promote();
    479             if (list != NULL) {
    480                 AutoMutex _l(list->lock());
    481 
    482                 // Demote from strong ref to weak after binderDied() has been delivered,
    483                 // to allow the DeathRecipient and BinderProxy to be GC'd if no longer needed.
    484                 mObjectWeak = env->NewWeakGlobalRef(mObject);
    485                 env->DeleteGlobalRef(mObject);
    486                 mObject = NULL;
    487             }
    488         }
    489     }
    490 
    491     void clearReference()
    492     {
    493         sp<DeathRecipientList> list = mList.promote();
    494         if (list != NULL) {
    495             LOGDEATH("Removing JDR %p from DRL %p", this, list.get());
    496             list->remove(this);
    497         } else {
    498             LOGDEATH("clearReference() on JDR %p but DRL wp purged", this);
    499         }
    500     }
    501 
    502     bool matches(jobject obj) {
    503         bool result;
    504         JNIEnv* env = javavm_to_jnienv(mVM);
    505 
    506         if (mObject != NULL) {
    507             result = env->IsSameObject(obj, mObject);
    508         } else {
    509             ScopedLocalRef<jobject> me(env, env->NewLocalRef(mObjectWeak));
    510             result = env->IsSameObject(obj, me.get());
    511         }
    512         return result;
    513     }
    514 
    515     void warnIfStillLive() {
    516         if (mObject != NULL) {
    517             // Okay, something is wrong -- we have a hard reference to a live death
    518             // recipient on the VM side, but the list is being torn down.
    519             JNIEnv* env = javavm_to_jnienv(mVM);
    520             ScopedLocalRef<jclass> objClassRef(env, env->GetObjectClass(mObject));
    521             ScopedLocalRef<jstring> nameRef(env,
    522                     (jstring) env->CallObjectMethod(objClassRef.get(), gClassOffsets.mGetName));
    523             ScopedUtfChars nameUtf(env, nameRef.get());
    524             if (nameUtf.c_str() != NULL) {
    525                 ALOGW("BinderProxy is being destroyed but the application did not call "
    526                         "unlinkToDeath to unlink all of its death recipients beforehand.  "
    527                         "Releasing leaked death recipient: %s", nameUtf.c_str());
    528             } else {
    529                 ALOGW("BinderProxy being destroyed; unable to get DR object name");
    530                 env->ExceptionClear();
    531             }
    532         }
    533     }
    534 
    535 protected:
    536     virtual ~JavaDeathRecipient()
    537     {
    538         //ALOGI("Removing death ref: recipient=%p\n", mObject);
    539         gNumDeathRefsDeleted.fetch_add(1, std::memory_order_relaxed);
    540         JNIEnv* env = javavm_to_jnienv(mVM);
    541         if (mObject != NULL) {
    542             env->DeleteGlobalRef(mObject);
    543         } else {
    544             env->DeleteWeakGlobalRef(mObjectWeak);
    545         }
    546     }
    547 
    548 private:
    549     JavaVM* const mVM;
    550     jobject mObject;  // Initial strong ref to Java-side DeathRecipient. Cleared on binderDied().
    551     jweak mObjectWeak; // Weak ref to the same Java-side DeathRecipient after binderDied().
    552     wp<DeathRecipientList> mList;
    553 };
    554 
    555 // ----------------------------------------------------------------------------
    556 
    557 DeathRecipientList::DeathRecipientList() {
    558     LOGDEATH("New DRL @ %p", this);
    559 }
    560 
    561 DeathRecipientList::~DeathRecipientList() {
    562     LOGDEATH("Destroy DRL @ %p", this);
    563     AutoMutex _l(mLock);
    564 
    565     // Should never happen -- the JavaDeathRecipient objects that have added themselves
    566     // to the list are holding references on the list object.  Only when they are torn
    567     // down can the list header be destroyed.
    568     if (mList.size() > 0) {
    569         List< sp<JavaDeathRecipient> >::iterator iter;
    570         for (iter = mList.begin(); iter != mList.end(); iter++) {
    571             (*iter)->warnIfStillLive();
    572         }
    573     }
    574 }
    575 
    576 void DeathRecipientList::add(const sp<JavaDeathRecipient>& recipient) {
    577     AutoMutex _l(mLock);
    578 
    579     LOGDEATH("DRL @ %p : add JDR %p", this, recipient.get());
    580     mList.push_back(recipient);
    581 }
    582 
    583 void DeathRecipientList::remove(const sp<JavaDeathRecipient>& recipient) {
    584     AutoMutex _l(mLock);
    585 
    586     List< sp<JavaDeathRecipient> >::iterator iter;
    587     for (iter = mList.begin(); iter != mList.end(); iter++) {
    588         if (*iter == recipient) {
    589             LOGDEATH("DRL @ %p : remove JDR %p", this, recipient.get());
    590             mList.erase(iter);
    591             return;
    592         }
    593     }
    594 }
    595 
    596 sp<JavaDeathRecipient> DeathRecipientList::find(jobject recipient) {
    597     AutoMutex _l(mLock);
    598 
    599     List< sp<JavaDeathRecipient> >::iterator iter;
    600     for (iter = mList.begin(); iter != mList.end(); iter++) {
    601         if ((*iter)->matches(recipient)) {
    602             return *iter;
    603         }
    604     }
    605     return NULL;
    606 }
    607 
    608 Mutex& DeathRecipientList::lock() {
    609     return mLock;
    610 }
    611 
    612 // ----------------------------------------------------------------------------
    613 
    614 namespace android {
    615 
    616 // We aggregate native pointer fields for BinderProxy in a single object to allow
    617 // management with a single NativeAllocationRegistry, and to reduce the number of JNI
    618 // Java field accesses. This costs us some extra indirections here.
    619 struct BinderProxyNativeData {
    620     // Both fields are constant and not null once javaObjectForIBinder returns this as
    621     // part of a BinderProxy.
    622 
    623     // The native IBinder proxied by this BinderProxy.
    624     sp<IBinder> mObject;
    625 
    626     // Death recipients for mObject. Reference counted only because DeathRecipients
    627     // hold a weak reference that can be temporarily promoted.
    628     sp<DeathRecipientList> mOrgue;  // Death recipients for mObject.
    629 };
    630 
    631 BinderProxyNativeData* getBPNativeData(JNIEnv* env, jobject obj) {
    632     return (BinderProxyNativeData *) env->GetLongField(obj, gBinderProxyOffsets.mNativeData);
    633 }
    634 
    635 static Mutex gProxyLock;
    636 
    637 // We may cache a single BinderProxyNativeData node to avoid repeat allocation.
    638 // All fields are null. Protected by gProxyLock.
    639 static BinderProxyNativeData *gNativeDataCache;
    640 
    641 // If the argument is a JavaBBinder, return the Java object that was used to create it.
    642 // Otherwise return a BinderProxy for the IBinder. If a previous call was passed the
    643 // same IBinder, and the original BinderProxy is still alive, return the same BinderProxy.
    644 jobject javaObjectForIBinder(JNIEnv* env, const sp<IBinder>& val)
    645 {
    646     if (val == NULL) return NULL;
    647 
    648     if (val->checkSubclass(&gBinderOffsets)) {
    649         // It's a JavaBBinder created by ibinderForJavaObject. Already has Java object.
    650         jobject object = static_cast<JavaBBinder*>(val.get())->object();
    651         LOGDEATH("objectForBinder %p: it's our own %p!\n", val.get(), object);
    652         return object;
    653     }
    654 
    655     // For the rest of the function we will hold this lock, to serialize
    656     // looking/creation/destruction of Java proxies for native Binder proxies.
    657     AutoMutex _l(gProxyLock);
    658 
    659     BinderProxyNativeData* nativeData = gNativeDataCache;
    660     if (nativeData == nullptr) {
    661         nativeData = new BinderProxyNativeData();
    662     }
    663     // gNativeDataCache is now logically empty.
    664     jobject object = env->CallStaticObjectMethod(gBinderProxyOffsets.mClass,
    665             gBinderProxyOffsets.mGetInstance, (jlong) nativeData, (jlong) val.get());
    666     if (env->ExceptionCheck()) {
    667         // In the exception case, getInstance still took ownership of nativeData.
    668         gNativeDataCache = nullptr;
    669         return NULL;
    670     }
    671     BinderProxyNativeData* actualNativeData = getBPNativeData(env, object);
    672     if (actualNativeData == nativeData) {
    673         // New BinderProxy; we still have exclusive access.
    674         nativeData->mOrgue = new DeathRecipientList;
    675         nativeData->mObject = val;
    676         gNativeDataCache = nullptr;
    677         ++gNumProxies;
    678         if (gNumProxies >= gProxiesWarned + PROXY_WARN_INTERVAL) {
    679             ALOGW("Unexpectedly many live BinderProxies: %d\n", gNumProxies);
    680             gProxiesWarned = gNumProxies;
    681         }
    682     } else {
    683         // nativeData wasn't used. Reuse it the next time.
    684         gNativeDataCache = nativeData;
    685     }
    686 
    687     return object;
    688 }
    689 
    690 sp<IBinder> ibinderForJavaObject(JNIEnv* env, jobject obj)
    691 {
    692     if (obj == NULL) return NULL;
    693 
    694     // Instance of Binder?
    695     if (env->IsInstanceOf(obj, gBinderOffsets.mClass)) {
    696         JavaBBinderHolder* jbh = (JavaBBinderHolder*)
    697             env->GetLongField(obj, gBinderOffsets.mObject);
    698         return jbh->get(env, obj);
    699     }
    700 
    701     // Instance of BinderProxy?
    702     if (env->IsInstanceOf(obj, gBinderProxyOffsets.mClass)) {
    703         return getBPNativeData(env, obj)->mObject;
    704     }
    705 
    706     ALOGW("ibinderForJavaObject: %p is not a Binder object", obj);
    707     return NULL;
    708 }
    709 
    710 jobject newParcelFileDescriptor(JNIEnv* env, jobject fileDesc)
    711 {
    712     return env->NewObject(
    713             gParcelFileDescriptorOffsets.mClass, gParcelFileDescriptorOffsets.mConstructor, fileDesc);
    714 }
    715 
    716 void set_dalvik_blockguard_policy(JNIEnv* env, jint strict_policy)
    717 {
    718     // Call back into android.os.StrictMode#onBinderStrictModePolicyChange
    719     // to sync our state back to it.  See the comments in StrictMode.java.
    720     env->CallStaticVoidMethod(gStrictModeCallbackOffsets.mClass,
    721                               gStrictModeCallbackOffsets.mCallback,
    722                               strict_policy);
    723 }
    724 
    725 void signalExceptionForError(JNIEnv* env, jobject obj, status_t err,
    726         bool canThrowRemoteException, int parcelSize)
    727 {
    728     switch (err) {
    729         case UNKNOWN_ERROR:
    730             jniThrowException(env, "java/lang/RuntimeException", "Unknown error");
    731             break;
    732         case NO_MEMORY:
    733             jniThrowException(env, "java/lang/OutOfMemoryError", NULL);
    734             break;
    735         case INVALID_OPERATION:
    736             jniThrowException(env, "java/lang/UnsupportedOperationException", NULL);
    737             break;
    738         case BAD_VALUE:
    739             jniThrowException(env, "java/lang/IllegalArgumentException", NULL);
    740             break;
    741         case BAD_INDEX:
    742             jniThrowException(env, "java/lang/IndexOutOfBoundsException", NULL);
    743             break;
    744         case BAD_TYPE:
    745             jniThrowException(env, "java/lang/IllegalArgumentException", NULL);
    746             break;
    747         case NAME_NOT_FOUND:
    748             jniThrowException(env, "java/util/NoSuchElementException", NULL);
    749             break;
    750         case PERMISSION_DENIED:
    751             jniThrowException(env, "java/lang/SecurityException", NULL);
    752             break;
    753         case NOT_ENOUGH_DATA:
    754             jniThrowException(env, "android/os/ParcelFormatException", "Not enough data");
    755             break;
    756         case NO_INIT:
    757             jniThrowException(env, "java/lang/RuntimeException", "Not initialized");
    758             break;
    759         case ALREADY_EXISTS:
    760             jniThrowException(env, "java/lang/RuntimeException", "Item already exists");
    761             break;
    762         case DEAD_OBJECT:
    763             // DeadObjectException is a checked exception, only throw from certain methods.
    764             jniThrowException(env, canThrowRemoteException
    765                     ? "android/os/DeadObjectException"
    766                             : "java/lang/RuntimeException", NULL);
    767             break;
    768         case UNKNOWN_TRANSACTION:
    769             jniThrowException(env, "java/lang/RuntimeException", "Unknown transaction code");
    770             break;
    771         case FAILED_TRANSACTION: {
    772             ALOGE("!!! FAILED BINDER TRANSACTION !!!  (parcel size = %d)", parcelSize);
    773             const char* exceptionToThrow;
    774             char msg[128];
    775             // TransactionTooLargeException is a checked exception, only throw from certain methods.
    776             // FIXME: Transaction too large is the most common reason for FAILED_TRANSACTION
    777             //        but it is not the only one.  The Binder driver can return BR_FAILED_REPLY
    778             //        for other reasons also, such as if the transaction is malformed or
    779             //        refers to an FD that has been closed.  We should change the driver
    780             //        to enable us to distinguish these cases in the future.
    781             if (canThrowRemoteException && parcelSize > 200*1024) {
    782                 // bona fide large payload
    783                 exceptionToThrow = "android/os/TransactionTooLargeException";
    784                 snprintf(msg, sizeof(msg)-1, "data parcel size %d bytes", parcelSize);
    785             } else {
    786                 // Heuristic: a payload smaller than this threshold "shouldn't" be too
    787                 // big, so it's probably some other, more subtle problem.  In practice
    788                 // it seems to always mean that the remote process died while the binder
    789                 // transaction was already in flight.
    790                 exceptionToThrow = (canThrowRemoteException)
    791                         ? "android/os/DeadObjectException"
    792                         : "java/lang/RuntimeException";
    793                 snprintf(msg, sizeof(msg)-1,
    794                         "Transaction failed on small parcel; remote process probably died");
    795             }
    796             jniThrowException(env, exceptionToThrow, msg);
    797         } break;
    798         case FDS_NOT_ALLOWED:
    799             jniThrowException(env, "java/lang/RuntimeException",
    800                     "Not allowed to write file descriptors here");
    801             break;
    802         case UNEXPECTED_NULL:
    803             jniThrowNullPointerException(env, NULL);
    804             break;
    805         case -EBADF:
    806             jniThrowException(env, "java/lang/RuntimeException",
    807                     "Bad file descriptor");
    808             break;
    809         case -ENFILE:
    810             jniThrowException(env, "java/lang/RuntimeException",
    811                     "File table overflow");
    812             break;
    813         case -EMFILE:
    814             jniThrowException(env, "java/lang/RuntimeException",
    815                     "Too many open files");
    816             break;
    817         case -EFBIG:
    818             jniThrowException(env, "java/lang/RuntimeException",
    819                     "File too large");
    820             break;
    821         case -ENOSPC:
    822             jniThrowException(env, "java/lang/RuntimeException",
    823                     "No space left on device");
    824             break;
    825         case -ESPIPE:
    826             jniThrowException(env, "java/lang/RuntimeException",
    827                     "Illegal seek");
    828             break;
    829         case -EROFS:
    830             jniThrowException(env, "java/lang/RuntimeException",
    831                     "Read-only file system");
    832             break;
    833         case -EMLINK:
    834             jniThrowException(env, "java/lang/RuntimeException",
    835                     "Too many links");
    836             break;
    837         default:
    838             ALOGE("Unknown binder error code. 0x%" PRIx32, err);
    839             String8 msg;
    840             msg.appendFormat("Unknown binder error code. 0x%" PRIx32, err);
    841             // RemoteException is a checked exception, only throw from certain methods.
    842             jniThrowException(env, canThrowRemoteException
    843                     ? "android/os/RemoteException" : "java/lang/RuntimeException", msg.string());
    844             break;
    845     }
    846 }
    847 
    848 }
    849 
    850 // ----------------------------------------------------------------------------
    851 
    852 static jint android_os_Binder_getCallingPid(JNIEnv* env, jobject clazz)
    853 {
    854     return IPCThreadState::self()->getCallingPid();
    855 }
    856 
    857 static jint android_os_Binder_getCallingUid(JNIEnv* env, jobject clazz)
    858 {
    859     return IPCThreadState::self()->getCallingUid();
    860 }
    861 
    862 static jlong android_os_Binder_clearCallingIdentity(JNIEnv* env, jobject clazz)
    863 {
    864     return IPCThreadState::self()->clearCallingIdentity();
    865 }
    866 
    867 static void android_os_Binder_restoreCallingIdentity(JNIEnv* env, jobject clazz, jlong token)
    868 {
    869     // XXX temporary sanity check to debug crashes.
    870     int uid = (int)(token>>32);
    871     if (uid > 0 && uid < 999) {
    872         // In Android currently there are no uids in this range.
    873         char buf[128];
    874         sprintf(buf, "Restoring bad calling ident: 0x%" PRIx64, token);
    875         jniThrowException(env, "java/lang/IllegalStateException", buf);
    876         return;
    877     }
    878     IPCThreadState::self()->restoreCallingIdentity(token);
    879 }
    880 
    881 static void android_os_Binder_setThreadStrictModePolicy(JNIEnv* env, jobject clazz, jint policyMask)
    882 {
    883     IPCThreadState::self()->setStrictModePolicy(policyMask);
    884 }
    885 
    886 static jint android_os_Binder_getThreadStrictModePolicy(JNIEnv* env, jobject clazz)
    887 {
    888     return IPCThreadState::self()->getStrictModePolicy();
    889 }
    890 
    891 static void android_os_Binder_flushPendingCommands(JNIEnv* env, jobject clazz)
    892 {
    893     IPCThreadState::self()->flushCommands();
    894 }
    895 
    896 static jlong android_os_Binder_getNativeBBinderHolder(JNIEnv* env, jobject clazz)
    897 {
    898     JavaBBinderHolder* jbh = new JavaBBinderHolder();
    899     return (jlong) jbh;
    900 }
    901 
    902 static void Binder_destroy(void* rawJbh)
    903 {
    904     JavaBBinderHolder* jbh = (JavaBBinderHolder*) rawJbh;
    905     ALOGV("Java Binder: deleting holder %p", jbh);
    906     delete jbh;
    907 }
    908 
    909 JNIEXPORT jlong JNICALL android_os_Binder_getNativeFinalizer(JNIEnv*, jclass) {
    910     return (jlong) Binder_destroy;
    911 }
    912 
    913 static void android_os_Binder_blockUntilThreadAvailable(JNIEnv* env, jobject clazz)
    914 {
    915     return IPCThreadState::self()->blockUntilThreadAvailable();
    916 }
    917 
    918 // ----------------------------------------------------------------------------
    919 
    920 static const JNINativeMethod gBinderMethods[] = {
    921      /* name, signature, funcPtr */
    922     { "getCallingPid", "()I", (void*)android_os_Binder_getCallingPid },
    923     { "getCallingUid", "()I", (void*)android_os_Binder_getCallingUid },
    924     { "clearCallingIdentity", "()J", (void*)android_os_Binder_clearCallingIdentity },
    925     { "restoreCallingIdentity", "(J)V", (void*)android_os_Binder_restoreCallingIdentity },
    926     { "setThreadStrictModePolicy", "(I)V", (void*)android_os_Binder_setThreadStrictModePolicy },
    927     { "getThreadStrictModePolicy", "()I", (void*)android_os_Binder_getThreadStrictModePolicy },
    928     { "flushPendingCommands", "()V", (void*)android_os_Binder_flushPendingCommands },
    929     { "getNativeBBinderHolder", "()J", (void*)android_os_Binder_getNativeBBinderHolder },
    930     { "getNativeFinalizer", "()J", (void*)android_os_Binder_getNativeFinalizer },
    931     { "blockUntilThreadAvailable", "()V", (void*)android_os_Binder_blockUntilThreadAvailable }
    932 };
    933 
    934 const char* const kBinderPathName = "android/os/Binder";
    935 
    936 static int int_register_android_os_Binder(JNIEnv* env)
    937 {
    938     jclass clazz = FindClassOrDie(env, kBinderPathName);
    939 
    940     gBinderOffsets.mClass = MakeGlobalRefOrDie(env, clazz);
    941     gBinderOffsets.mExecTransact = GetMethodIDOrDie(env, clazz, "execTransact", "(IJJI)Z");
    942     gBinderOffsets.mObject = GetFieldIDOrDie(env, clazz, "mObject", "J");
    943 
    944     return RegisterMethodsOrDie(
    945         env, kBinderPathName,
    946         gBinderMethods, NELEM(gBinderMethods));
    947 }
    948 
    949 // ****************************************************************************
    950 // ****************************************************************************
    951 // ****************************************************************************
    952 
    953 namespace android {
    954 
    955 jint android_os_Debug_getLocalObjectCount(JNIEnv* env, jobject clazz)
    956 {
    957     return gNumLocalRefsCreated - gNumLocalRefsDeleted;
    958 }
    959 
    960 jint android_os_Debug_getProxyObjectCount(JNIEnv* env, jobject clazz)
    961 {
    962     AutoMutex _l(gProxyLock);
    963     return gNumProxies;
    964 }
    965 
    966 jint android_os_Debug_getDeathObjectCount(JNIEnv* env, jobject clazz)
    967 {
    968     return gNumDeathRefsCreated - gNumDeathRefsDeleted;
    969 }
    970 
    971 }
    972 
    973 // ****************************************************************************
    974 // ****************************************************************************
    975 // ****************************************************************************
    976 
    977 static jobject android_os_BinderInternal_getContextObject(JNIEnv* env, jobject clazz)
    978 {
    979     sp<IBinder> b = ProcessState::self()->getContextObject(NULL);
    980     return javaObjectForIBinder(env, b);
    981 }
    982 
    983 static void android_os_BinderInternal_joinThreadPool(JNIEnv* env, jobject clazz)
    984 {
    985     sp<IBinder> b = ProcessState::self()->getContextObject(NULL);
    986     android::IPCThreadState::self()->joinThreadPool();
    987 }
    988 
    989 static void android_os_BinderInternal_disableBackgroundScheduling(JNIEnv* env,
    990         jobject clazz, jboolean disable)
    991 {
    992     IPCThreadState::disableBackgroundScheduling(disable ? true : false);
    993 }
    994 
    995 static void android_os_BinderInternal_setMaxThreads(JNIEnv* env,
    996         jobject clazz, jint maxThreads)
    997 {
    998     ProcessState::self()->setThreadPoolMaxThreadCount(maxThreads);
    999 }
   1000 
   1001 static void android_os_BinderInternal_handleGc(JNIEnv* env, jobject clazz)
   1002 {
   1003     ALOGV("Gc has executed, updating Refs count at GC");
   1004     gCollectedAtRefs = gNumLocalRefsCreated + gNumDeathRefsCreated;
   1005 }
   1006 
   1007 static void android_os_BinderInternal_proxyLimitcallback(int uid)
   1008 {
   1009     JNIEnv *env = AndroidRuntime::getJNIEnv();
   1010     {
   1011         // Calls into BinderProxy must be serialized
   1012         AutoMutex _l(gProxyLock);
   1013         env->CallStaticObjectMethod(gBinderProxyOffsets.mClass,
   1014                                     gBinderProxyOffsets.mDumpProxyDebugInfo);
   1015     }
   1016     if (env->ExceptionCheck()) {
   1017         ScopedLocalRef<jthrowable> excep(env, env->ExceptionOccurred());
   1018         report_exception(env, excep.get(),
   1019             "*** Uncaught exception in dumpProxyDebugInfo");
   1020     }
   1021 
   1022     env->CallStaticVoidMethod(gBinderInternalOffsets.mClass,
   1023                               gBinderInternalOffsets.mProxyLimitCallback,
   1024                               uid);
   1025 
   1026     if (env->ExceptionCheck()) {
   1027         ScopedLocalRef<jthrowable> excep(env, env->ExceptionOccurred());
   1028         report_exception(env, excep.get(),
   1029             "*** Uncaught exception in binderProxyLimitCallbackFromNative");
   1030     }
   1031 }
   1032 
   1033 static void android_os_BinderInternal_setBinderProxyCountEnabled(JNIEnv* env, jobject clazz,
   1034                                                                  jboolean enable)
   1035 {
   1036     BpBinder::setCountByUidEnabled((bool) enable);
   1037 }
   1038 
   1039 static jobject android_os_BinderInternal_getBinderProxyPerUidCounts(JNIEnv* env, jclass clazz)
   1040 {
   1041     Vector<uint32_t> uids, counts;
   1042     BpBinder::getCountByUid(uids, counts);
   1043     jobject sparseIntArray = env->NewObject(gSparseIntArrayOffsets.classObject,
   1044                                             gSparseIntArrayOffsets.constructor);
   1045     for (size_t i = 0; i < uids.size(); i++) {
   1046         env->CallVoidMethod(sparseIntArray, gSparseIntArrayOffsets.put,
   1047                             static_cast<jint>(uids[i]), static_cast<jint>(counts[i]));
   1048     }
   1049     return sparseIntArray;
   1050 }
   1051 
   1052 static jint android_os_BinderInternal_getBinderProxyCount(JNIEnv* env, jobject clazz, jint uid) {
   1053     return static_cast<jint>(BpBinder::getBinderProxyCount(static_cast<uint32_t>(uid)));
   1054 }
   1055 
   1056 static void android_os_BinderInternal_setBinderProxyCountWatermarks(JNIEnv* env, jobject clazz,
   1057                                                                     jint high, jint low)
   1058 {
   1059     BpBinder::setBinderProxyCountWatermarks(high, low);
   1060 }
   1061 
   1062 // ----------------------------------------------------------------------------
   1063 
   1064 static const JNINativeMethod gBinderInternalMethods[] = {
   1065      /* name, signature, funcPtr */
   1066     { "getContextObject", "()Landroid/os/IBinder;", (void*)android_os_BinderInternal_getContextObject },
   1067     { "joinThreadPool", "()V", (void*)android_os_BinderInternal_joinThreadPool },
   1068     { "disableBackgroundScheduling", "(Z)V", (void*)android_os_BinderInternal_disableBackgroundScheduling },
   1069     { "setMaxThreads", "(I)V", (void*)android_os_BinderInternal_setMaxThreads },
   1070     { "handleGc", "()V", (void*)android_os_BinderInternal_handleGc },
   1071     { "nSetBinderProxyCountEnabled", "(Z)V", (void*)android_os_BinderInternal_setBinderProxyCountEnabled },
   1072     { "nGetBinderProxyPerUidCounts", "()Landroid/util/SparseIntArray;", (void*)android_os_BinderInternal_getBinderProxyPerUidCounts },
   1073     { "nGetBinderProxyCount", "(I)I", (void*)android_os_BinderInternal_getBinderProxyCount },
   1074     { "nSetBinderProxyCountWatermarks", "(II)V", (void*)android_os_BinderInternal_setBinderProxyCountWatermarks}
   1075 };
   1076 
   1077 const char* const kBinderInternalPathName = "com/android/internal/os/BinderInternal";
   1078 
   1079 static int int_register_android_os_BinderInternal(JNIEnv* env)
   1080 {
   1081     jclass clazz = FindClassOrDie(env, kBinderInternalPathName);
   1082 
   1083     gBinderInternalOffsets.mClass = MakeGlobalRefOrDie(env, clazz);
   1084     gBinderInternalOffsets.mForceGc = GetStaticMethodIDOrDie(env, clazz, "forceBinderGc", "()V");
   1085     gBinderInternalOffsets.mProxyLimitCallback = GetStaticMethodIDOrDie(env, clazz, "binderProxyLimitCallbackFromNative", "(I)V");
   1086 
   1087     jclass SparseIntArrayClass = FindClassOrDie(env, "android/util/SparseIntArray");
   1088     gSparseIntArrayOffsets.classObject = MakeGlobalRefOrDie(env, SparseIntArrayClass);
   1089     gSparseIntArrayOffsets.constructor = GetMethodIDOrDie(env, gSparseIntArrayOffsets.classObject,
   1090                                                            "<init>", "()V");
   1091     gSparseIntArrayOffsets.put = GetMethodIDOrDie(env, gSparseIntArrayOffsets.classObject, "put",
   1092                                                    "(II)V");
   1093 
   1094     BpBinder::setLimitCallback(android_os_BinderInternal_proxyLimitcallback);
   1095 
   1096     return RegisterMethodsOrDie(
   1097         env, kBinderInternalPathName,
   1098         gBinderInternalMethods, NELEM(gBinderInternalMethods));
   1099 }
   1100 
   1101 // ****************************************************************************
   1102 // ****************************************************************************
   1103 // ****************************************************************************
   1104 
   1105 static jboolean android_os_BinderProxy_pingBinder(JNIEnv* env, jobject obj)
   1106 {
   1107     IBinder* target = getBPNativeData(env, obj)->mObject.get();
   1108     if (target == NULL) {
   1109         return JNI_FALSE;
   1110     }
   1111     status_t err = target->pingBinder();
   1112     return err == NO_ERROR ? JNI_TRUE : JNI_FALSE;
   1113 }
   1114 
   1115 static jstring android_os_BinderProxy_getInterfaceDescriptor(JNIEnv* env, jobject obj)
   1116 {
   1117     IBinder* target = getBPNativeData(env, obj)->mObject.get();
   1118     if (target != NULL) {
   1119         const String16& desc = target->getInterfaceDescriptor();
   1120         return env->NewString(reinterpret_cast<const jchar*>(desc.string()),
   1121                               desc.size());
   1122     }
   1123     jniThrowException(env, "java/lang/RuntimeException",
   1124             "No binder found for object");
   1125     return NULL;
   1126 }
   1127 
   1128 static jboolean android_os_BinderProxy_isBinderAlive(JNIEnv* env, jobject obj)
   1129 {
   1130     IBinder* target = getBPNativeData(env, obj)->mObject.get();
   1131     if (target == NULL) {
   1132         return JNI_FALSE;
   1133     }
   1134     bool alive = target->isBinderAlive();
   1135     return alive ? JNI_TRUE : JNI_FALSE;
   1136 }
   1137 
   1138 static int getprocname(pid_t pid, char *buf, size_t len) {
   1139     char filename[32];
   1140     FILE *f;
   1141 
   1142     snprintf(filename, sizeof(filename), "/proc/%d/cmdline", pid);
   1143     f = fopen(filename, "r");
   1144     if (!f) {
   1145         *buf = '\0';
   1146         return 1;
   1147     }
   1148     if (!fgets(buf, len, f)) {
   1149         *buf = '\0';
   1150         fclose(f);
   1151         return 2;
   1152     }
   1153     fclose(f);
   1154     return 0;
   1155 }
   1156 
   1157 static bool push_eventlog_string(char** pos, const char* end, const char* str) {
   1158     jint len = strlen(str);
   1159     int space_needed = 1 + sizeof(len) + len;
   1160     if (end - *pos < space_needed) {
   1161         ALOGW("not enough space for string. remain=%" PRIdPTR "; needed=%d",
   1162              end - *pos, space_needed);
   1163         return false;
   1164     }
   1165     **pos = EVENT_TYPE_STRING;
   1166     (*pos)++;
   1167     memcpy(*pos, &len, sizeof(len));
   1168     *pos += sizeof(len);
   1169     memcpy(*pos, str, len);
   1170     *pos += len;
   1171     return true;
   1172 }
   1173 
   1174 static bool push_eventlog_int(char** pos, const char* end, jint val) {
   1175     int space_needed = 1 + sizeof(val);
   1176     if (end - *pos < space_needed) {
   1177         ALOGW("not enough space for int.  remain=%" PRIdPTR "; needed=%d",
   1178              end - *pos, space_needed);
   1179         return false;
   1180     }
   1181     **pos = EVENT_TYPE_INT;
   1182     (*pos)++;
   1183     memcpy(*pos, &val, sizeof(val));
   1184     *pos += sizeof(val);
   1185     return true;
   1186 }
   1187 
   1188 // From frameworks/base/core/java/android/content/EventLogTags.logtags:
   1189 
   1190 static const bool kEnableBinderSample = false;
   1191 
   1192 #define LOGTAG_BINDER_OPERATION 52004
   1193 
   1194 static void conditionally_log_binder_call(int64_t start_millis,
   1195                                           IBinder* target, jint code) {
   1196     int duration_ms = static_cast<int>(uptimeMillis() - start_millis);
   1197 
   1198     int sample_percent;
   1199     if (duration_ms >= 500) {
   1200         sample_percent = 100;
   1201     } else {
   1202         sample_percent = 100 * duration_ms / 500;
   1203         if (sample_percent == 0) {
   1204             return;
   1205         }
   1206         if (sample_percent < (random() % 100 + 1)) {
   1207             return;
   1208         }
   1209     }
   1210 
   1211     char process_name[40];
   1212     getprocname(getpid(), process_name, sizeof(process_name));
   1213     String8 desc(target->getInterfaceDescriptor());
   1214 
   1215     char buf[LOGGER_ENTRY_MAX_PAYLOAD];
   1216     buf[0] = EVENT_TYPE_LIST;
   1217     buf[1] = 5;
   1218     char* pos = &buf[2];
   1219     char* end = &buf[LOGGER_ENTRY_MAX_PAYLOAD - 1];  // leave room for final \n
   1220     if (!push_eventlog_string(&pos, end, desc.string())) return;
   1221     if (!push_eventlog_int(&pos, end, code)) return;
   1222     if (!push_eventlog_int(&pos, end, duration_ms)) return;
   1223     if (!push_eventlog_string(&pos, end, process_name)) return;
   1224     if (!push_eventlog_int(&pos, end, sample_percent)) return;
   1225     *(pos++) = '\n';   // conventional with EVENT_TYPE_LIST apparently.
   1226     android_bWriteLog(LOGTAG_BINDER_OPERATION, buf, pos - buf);
   1227 }
   1228 
   1229 // We only measure binder call durations to potentially log them if
   1230 // we're on the main thread.
   1231 static bool should_time_binder_calls() {
   1232   return (getpid() == gettid());
   1233 }
   1234 
   1235 static jboolean android_os_BinderProxy_transact(JNIEnv* env, jobject obj,
   1236         jint code, jobject dataObj, jobject replyObj, jint flags) // throws RemoteException
   1237 {
   1238     if (dataObj == NULL) {
   1239         jniThrowNullPointerException(env, NULL);
   1240         return JNI_FALSE;
   1241     }
   1242 
   1243     Parcel* data = parcelForJavaObject(env, dataObj);
   1244     if (data == NULL) {
   1245         return JNI_FALSE;
   1246     }
   1247     Parcel* reply = parcelForJavaObject(env, replyObj);
   1248     if (reply == NULL && replyObj != NULL) {
   1249         return JNI_FALSE;
   1250     }
   1251 
   1252     IBinder* target = getBPNativeData(env, obj)->mObject.get();
   1253     if (target == NULL) {
   1254         jniThrowException(env, "java/lang/IllegalStateException", "Binder has been finalized!");
   1255         return JNI_FALSE;
   1256     }
   1257 
   1258     ALOGV("Java code calling transact on %p in Java object %p with code %" PRId32 "\n",
   1259             target, obj, code);
   1260 
   1261 
   1262     bool time_binder_calls;
   1263     int64_t start_millis;
   1264     if (kEnableBinderSample) {
   1265         // Only log the binder call duration for things on the Java-level main thread.
   1266         // But if we don't
   1267         time_binder_calls = should_time_binder_calls();
   1268 
   1269         if (time_binder_calls) {
   1270             start_millis = uptimeMillis();
   1271         }
   1272     }
   1273 
   1274     //printf("Transact from Java code to %p sending: ", target); data->print();
   1275     status_t err = target->transact(code, *data, reply, flags);
   1276     //if (reply) printf("Transact from Java code to %p received: ", target); reply->print();
   1277 
   1278     if (kEnableBinderSample) {
   1279         if (time_binder_calls) {
   1280             conditionally_log_binder_call(start_millis, target, code);
   1281         }
   1282     }
   1283 
   1284     if (err == NO_ERROR) {
   1285         return JNI_TRUE;
   1286     } else if (err == UNKNOWN_TRANSACTION) {
   1287         return JNI_FALSE;
   1288     }
   1289 
   1290     signalExceptionForError(env, obj, err, true /*canThrowRemoteException*/, data->dataSize());
   1291     return JNI_FALSE;
   1292 }
   1293 
   1294 static void android_os_BinderProxy_linkToDeath(JNIEnv* env, jobject obj,
   1295         jobject recipient, jint flags) // throws RemoteException
   1296 {
   1297     if (recipient == NULL) {
   1298         jniThrowNullPointerException(env, NULL);
   1299         return;
   1300     }
   1301 
   1302     BinderProxyNativeData *nd = getBPNativeData(env, obj);
   1303     IBinder* target = nd->mObject.get();
   1304 
   1305     LOGDEATH("linkToDeath: binder=%p recipient=%p\n", target, recipient);
   1306 
   1307     if (!target->localBinder()) {
   1308         DeathRecipientList* list = nd->mOrgue.get();
   1309         sp<JavaDeathRecipient> jdr = new JavaDeathRecipient(env, recipient, list);
   1310         status_t err = target->linkToDeath(jdr, NULL, flags);
   1311         if (err != NO_ERROR) {
   1312             // Failure adding the death recipient, so clear its reference
   1313             // now.
   1314             jdr->clearReference();
   1315             signalExceptionForError(env, obj, err, true /*canThrowRemoteException*/);
   1316         }
   1317     }
   1318 }
   1319 
   1320 static jboolean android_os_BinderProxy_unlinkToDeath(JNIEnv* env, jobject obj,
   1321                                                  jobject recipient, jint flags)
   1322 {
   1323     jboolean res = JNI_FALSE;
   1324     if (recipient == NULL) {
   1325         jniThrowNullPointerException(env, NULL);
   1326         return res;
   1327     }
   1328 
   1329     BinderProxyNativeData* nd = getBPNativeData(env, obj);
   1330     IBinder* target = nd->mObject.get();
   1331     if (target == NULL) {
   1332         ALOGW("Binder has been finalized when calling linkToDeath() with recip=%p)\n", recipient);
   1333         return JNI_FALSE;
   1334     }
   1335 
   1336     LOGDEATH("unlinkToDeath: binder=%p recipient=%p\n", target, recipient);
   1337 
   1338     if (!target->localBinder()) {
   1339         status_t err = NAME_NOT_FOUND;
   1340 
   1341         // If we find the matching recipient, proceed to unlink using that
   1342         DeathRecipientList* list = nd->mOrgue.get();
   1343         sp<JavaDeathRecipient> origJDR = list->find(recipient);
   1344         LOGDEATH("   unlink found list %p and JDR %p", list, origJDR.get());
   1345         if (origJDR != NULL) {
   1346             wp<IBinder::DeathRecipient> dr;
   1347             err = target->unlinkToDeath(origJDR, NULL, flags, &dr);
   1348             if (err == NO_ERROR && dr != NULL) {
   1349                 sp<IBinder::DeathRecipient> sdr = dr.promote();
   1350                 JavaDeathRecipient* jdr = static_cast<JavaDeathRecipient*>(sdr.get());
   1351                 if (jdr != NULL) {
   1352                     jdr->clearReference();
   1353                 }
   1354             }
   1355         }
   1356 
   1357         if (err == NO_ERROR || err == DEAD_OBJECT) {
   1358             res = JNI_TRUE;
   1359         } else {
   1360             jniThrowException(env, "java/util/NoSuchElementException",
   1361                               "Death link does not exist");
   1362         }
   1363     }
   1364 
   1365     return res;
   1366 }
   1367 
   1368 static void BinderProxy_destroy(void* rawNativeData)
   1369 {
   1370     // Don't race with construction/initialization
   1371     AutoMutex _l(gProxyLock);
   1372 
   1373     BinderProxyNativeData * nativeData = (BinderProxyNativeData *) rawNativeData;
   1374     LOGDEATH("Destroying BinderProxy: binder=%p drl=%p\n",
   1375             nativeData->mObject.get(), nativeData->mOrgue.get());
   1376     delete nativeData;
   1377     IPCThreadState::self()->flushCommands();
   1378     --gNumProxies;
   1379 }
   1380 
   1381 JNIEXPORT jlong JNICALL android_os_BinderProxy_getNativeFinalizer(JNIEnv*, jclass) {
   1382     return (jlong) BinderProxy_destroy;
   1383 }
   1384 
   1385 // ----------------------------------------------------------------------------
   1386 
   1387 static const JNINativeMethod gBinderProxyMethods[] = {
   1388      /* name, signature, funcPtr */
   1389     {"pingBinder",          "()Z", (void*)android_os_BinderProxy_pingBinder},
   1390     {"isBinderAlive",       "()Z", (void*)android_os_BinderProxy_isBinderAlive},
   1391     {"getInterfaceDescriptor", "()Ljava/lang/String;", (void*)android_os_BinderProxy_getInterfaceDescriptor},
   1392     {"transactNative",      "(ILandroid/os/Parcel;Landroid/os/Parcel;I)Z", (void*)android_os_BinderProxy_transact},
   1393     {"linkToDeath",         "(Landroid/os/IBinder$DeathRecipient;I)V", (void*)android_os_BinderProxy_linkToDeath},
   1394     {"unlinkToDeath",       "(Landroid/os/IBinder$DeathRecipient;I)Z", (void*)android_os_BinderProxy_unlinkToDeath},
   1395     {"getNativeFinalizer",  "()J", (void*)android_os_BinderProxy_getNativeFinalizer},
   1396 };
   1397 
   1398 const char* const kBinderProxyPathName = "android/os/BinderProxy";
   1399 
   1400 static int int_register_android_os_BinderProxy(JNIEnv* env)
   1401 {
   1402     jclass clazz = FindClassOrDie(env, "java/lang/Error");
   1403     gErrorOffsets.mClass = MakeGlobalRefOrDie(env, clazz);
   1404 
   1405     clazz = FindClassOrDie(env, kBinderProxyPathName);
   1406     gBinderProxyOffsets.mClass = MakeGlobalRefOrDie(env, clazz);
   1407     gBinderProxyOffsets.mGetInstance = GetStaticMethodIDOrDie(env, clazz, "getInstance",
   1408             "(JJ)Landroid/os/BinderProxy;");
   1409     gBinderProxyOffsets.mSendDeathNotice = GetStaticMethodIDOrDie(env, clazz, "sendDeathNotice",
   1410             "(Landroid/os/IBinder$DeathRecipient;)V");
   1411     gBinderProxyOffsets.mDumpProxyDebugInfo = GetStaticMethodIDOrDie(env, clazz, "dumpProxyDebugInfo",
   1412             "()V");
   1413     gBinderProxyOffsets.mNativeData = GetFieldIDOrDie(env, clazz, "mNativeData", "J");
   1414 
   1415     clazz = FindClassOrDie(env, "java/lang/Class");
   1416     gClassOffsets.mGetName = GetMethodIDOrDie(env, clazz, "getName", "()Ljava/lang/String;");
   1417 
   1418     return RegisterMethodsOrDie(
   1419         env, kBinderProxyPathName,
   1420         gBinderProxyMethods, NELEM(gBinderProxyMethods));
   1421 }
   1422 
   1423 // ****************************************************************************
   1424 // ****************************************************************************
   1425 // ****************************************************************************
   1426 
   1427 int register_android_os_Binder(JNIEnv* env)
   1428 {
   1429     if (int_register_android_os_Binder(env) < 0)
   1430         return -1;
   1431     if (int_register_android_os_BinderInternal(env) < 0)
   1432         return -1;
   1433     if (int_register_android_os_BinderProxy(env) < 0)
   1434         return -1;
   1435 
   1436     jclass clazz = FindClassOrDie(env, "android/util/Log");
   1437     gLogOffsets.mClass = MakeGlobalRefOrDie(env, clazz);
   1438     gLogOffsets.mLogE = GetStaticMethodIDOrDie(env, clazz, "e",
   1439             "(Ljava/lang/String;Ljava/lang/String;Ljava/lang/Throwable;)I");
   1440 
   1441     clazz = FindClassOrDie(env, "android/os/ParcelFileDescriptor");
   1442     gParcelFileDescriptorOffsets.mClass = MakeGlobalRefOrDie(env, clazz);
   1443     gParcelFileDescriptorOffsets.mConstructor = GetMethodIDOrDie(env, clazz, "<init>",
   1444                                                                  "(Ljava/io/FileDescriptor;)V");
   1445 
   1446     clazz = FindClassOrDie(env, "android/os/StrictMode");
   1447     gStrictModeCallbackOffsets.mClass = MakeGlobalRefOrDie(env, clazz);
   1448     gStrictModeCallbackOffsets.mCallback = GetStaticMethodIDOrDie(env, clazz,
   1449             "onBinderStrictModePolicyChange", "(I)V");
   1450 
   1451     clazz = FindClassOrDie(env, "java/lang/Thread");
   1452     gThreadDispatchOffsets.mClass = MakeGlobalRefOrDie(env, clazz);
   1453     gThreadDispatchOffsets.mDispatchUncaughtException = GetMethodIDOrDie(env, clazz,
   1454             "dispatchUncaughtException", "(Ljava/lang/Throwable;)V");
   1455     gThreadDispatchOffsets.mCurrentThread = GetStaticMethodIDOrDie(env, clazz, "currentThread",
   1456             "()Ljava/lang/Thread;");
   1457 
   1458     return 0;
   1459 }
   1460