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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 <mutex>
27 #include <stdio.h>
28 #include <sys/stat.h>
29 #include <sys/types.h>
30 #include <unistd.h>
31 
32 #include <android-base/stringprintf.h>
33 #include <binder/IInterface.h>
34 #include <binder/IServiceManager.h>
35 #include <binder/IPCThreadState.h>
36 #include <binder/Parcel.h>
37 #include <binder/BpBinder.h>
38 #include <binder/ProcessState.h>
39 #include <cutils/atomic.h>
40 #include <log/log.h>
41 #include <utils/KeyedVector.h>
42 #include <utils/List.h>
43 #include <utils/Log.h>
44 #include <utils/String8.h>
45 #include <utils/SystemClock.h>
46 #include <utils/threads.h>
47 
48 #include <nativehelper/JNIHelp.h>
49 #include <nativehelper/ScopedLocalRef.h>
50 #include <nativehelper/ScopedUtfChars.h>
51 
52 #include "core_jni_helpers.h"
53 
54 //#undef ALOGV
55 //#define ALOGV(...) fprintf(stderr, __VA_ARGS__)
56 
57 #define DEBUG_DEATH 0
58 #if DEBUG_DEATH
59 #define LOGDEATH ALOGD
60 #else
61 #define LOGDEATH ALOGV
62 #endif
63 
64 using namespace android;
65 
66 // ----------------------------------------------------------------------------
67 
68 static struct bindernative_offsets_t
69 {
70     // Class state.
71     jclass mClass;
72     jmethodID mExecTransact;
73     jmethodID mGetInterfaceDescriptor;
74 
75     // Object state.
76     jfieldID mObject;
77 
78 } gBinderOffsets;
79 
80 // ----------------------------------------------------------------------------
81 
82 static struct binderinternal_offsets_t
83 {
84     // Class state.
85     jclass mClass;
86     jmethodID mForceGc;
87     jmethodID mProxyLimitCallback;
88 
89 } gBinderInternalOffsets;
90 
91 static struct sparseintarray_offsets_t
92 {
93     jclass classObject;
94     jmethodID constructor;
95     jmethodID put;
96 } gSparseIntArrayOffsets;
97 
98 // ----------------------------------------------------------------------------
99 
100 static struct error_offsets_t
101 {
102     jclass mClass;
103 } gErrorOffsets;
104 
105 // ----------------------------------------------------------------------------
106 
107 static struct binderproxy_offsets_t
108 {
109     // Class state.
110     jclass mClass;
111     jmethodID mGetInstance;
112     jmethodID mSendDeathNotice;
113 
114     // Object state.
115     jfieldID mNativeData;  // Field holds native pointer to BinderProxyNativeData.
116 } gBinderProxyOffsets;
117 
118 static struct class_offsets_t
119 {
120     jmethodID mGetName;
121 } gClassOffsets;
122 
123 // ----------------------------------------------------------------------------
124 
125 static struct log_offsets_t
126 {
127     // Class state.
128     jclass mClass;
129     jmethodID mLogE;
130 } gLogOffsets;
131 
132 static struct parcel_file_descriptor_offsets_t
133 {
134     jclass mClass;
135     jmethodID mConstructor;
136 } gParcelFileDescriptorOffsets;
137 
138 static struct strict_mode_callback_offsets_t
139 {
140     jclass mClass;
141     jmethodID mCallback;
142 } gStrictModeCallbackOffsets;
143 
144 static struct thread_dispatch_offsets_t
145 {
146     // Class state.
147     jclass mClass;
148     jmethodID mDispatchUncaughtException;
149     jmethodID mCurrentThread;
150 } gThreadDispatchOffsets;
151 
152 // ****************************************************************************
153 // ****************************************************************************
154 // ****************************************************************************
155 
156 static constexpr int32_t PROXY_WARN_INTERVAL = 5000;
157 static constexpr uint32_t GC_INTERVAL = 1000;
158 
159 static std::atomic<uint32_t> gNumProxies(0);
160 static std::atomic<uint32_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")))
gcIfManyNewRefs(JNIEnv * env)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 
jnienv_to_javavm(JNIEnv * env)198 static JavaVM* jnienv_to_javavm(JNIEnv* env)
199 {
200     JavaVM* vm;
201     return env->GetJavaVM(&vm) >= 0 ? vm : NULL;
202 }
203 
javavm_to_jnienv(JavaVM * vm)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.
report_java_lang_error_fatal_error(JNIEnv * env,jthrowable error,const char * msg)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.
report_java_lang_error(JNIEnv * env,jthrowable error,const char * msg)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 
report_exception(JNIEnv * env,jthrowable excep,const char * msg)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:
JavaBBinder(JNIEnv * env,jobject object)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 
checkSubclass(const void * subclassID) const312     bool    checkSubclass(const void* subclassID) const
313     {
314         return subclassID == &gBinderOffsets;
315     }
316 
object() const317     jobject object() const
318     {
319         return mObject;
320     }
321 
322 protected:
~JavaBBinder()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 
getInterfaceDescriptor() const331     const String16& getInterfaceDescriptor() const override
332     {
333         call_once(mPopulateDescriptor, [this] {
334             JNIEnv* env = javavm_to_jnienv(mVM);
335 
336             ALOGV("getInterfaceDescriptor() on %p calling object %p in env %p vm %p\n", this, mObject, env, mVM);
337 
338             jstring descriptor = (jstring)env->CallObjectMethod(mObject, gBinderOffsets.mGetInterfaceDescriptor);
339 
340             if (descriptor == nullptr) {
341                 return;
342             }
343 
344             static_assert(sizeof(jchar) == sizeof(char16_t), "");
345             const jchar* descriptorChars = env->GetStringChars(descriptor, nullptr);
346             const char16_t* rawDescriptor = reinterpret_cast<const char16_t*>(descriptorChars);
347             jsize rawDescriptorLen = env->GetStringLength(descriptor);
348             mDescriptor = String16(rawDescriptor, rawDescriptorLen);
349             env->ReleaseStringChars(descriptor, descriptorChars);
350         });
351 
352         return mDescriptor;
353     }
354 
onTransact(uint32_t code,const Parcel & data,Parcel * reply,uint32_t flags=0)355     status_t onTransact(
356         uint32_t code, const Parcel& data, Parcel* reply, uint32_t flags = 0) override
357     {
358         JNIEnv* env = javavm_to_jnienv(mVM);
359 
360         ALOGV("onTransact() on %p calling object %p in env %p vm %p\n", this, mObject, env, mVM);
361 
362         IPCThreadState* thread_state = IPCThreadState::self();
363         const int32_t strict_policy_before = thread_state->getStrictModePolicy();
364 
365         //printf("Transact from %p to Java code sending: ", this);
366         //data.print();
367         //printf("\n");
368         jboolean res = env->CallBooleanMethod(mObject, gBinderOffsets.mExecTransact,
369             code, reinterpret_cast<jlong>(&data), reinterpret_cast<jlong>(reply), flags);
370 
371         if (env->ExceptionCheck()) {
372             ScopedLocalRef<jthrowable> excep(env, env->ExceptionOccurred());
373             report_exception(env, excep.get(),
374                 "*** Uncaught remote exception!  "
375                 "(Exceptions are not yet supported across processes.)");
376             res = JNI_FALSE;
377         }
378 
379         // Check if the strict mode state changed while processing the
380         // call.  The Binder state will be restored by the underlying
381         // Binder system in IPCThreadState, however we need to take care
382         // of the parallel Java state as well.
383         if (thread_state->getStrictModePolicy() != strict_policy_before) {
384             set_dalvik_blockguard_policy(env, strict_policy_before);
385         }
386 
387         if (env->ExceptionCheck()) {
388             ScopedLocalRef<jthrowable> excep(env, env->ExceptionOccurred());
389             report_exception(env, excep.get(),
390                 "*** Uncaught exception in onBinderStrictModePolicyChange");
391         }
392 
393         // Need to always call through the native implementation of
394         // SYSPROPS_TRANSACTION.
395         if (code == SYSPROPS_TRANSACTION) {
396             BBinder::onTransact(code, data, reply, flags);
397         }
398 
399         //aout << "onTransact to Java code; result=" << res << endl
400         //    << "Transact from " << this << " to Java code returning "
401         //    << reply << ": " << *reply << endl;
402         return res != JNI_FALSE ? NO_ERROR : UNKNOWN_TRANSACTION;
403     }
404 
dump(int fd,const Vector<String16> & args)405     status_t dump(int fd, const Vector<String16>& args) override
406     {
407         return 0;
408     }
409 
410 private:
411     JavaVM* const   mVM;
412     jobject const   mObject;  // GlobalRef to Java Binder
413 
414     mutable std::once_flag mPopulateDescriptor;
415     mutable String16 mDescriptor;
416 };
417 
418 // ----------------------------------------------------------------------------
419 
420 class JavaBBinderHolder
421 {
422 public:
get(JNIEnv * env,jobject obj)423     sp<JavaBBinder> get(JNIEnv* env, jobject obj)
424     {
425         AutoMutex _l(mLock);
426         sp<JavaBBinder> b = mBinder.promote();
427         if (b == NULL) {
428             b = new JavaBBinder(env, obj);
429             mBinder = b;
430             ALOGV("Creating JavaBinder %p (refs %p) for Object %p, weakCount=%" PRId32 "\n",
431                  b.get(), b->getWeakRefs(), obj, b->getWeakRefs()->getWeakCount());
432         }
433 
434         return b;
435     }
436 
getExisting()437     sp<JavaBBinder> getExisting()
438     {
439         AutoMutex _l(mLock);
440         return mBinder.promote();
441     }
442 
443 private:
444     Mutex           mLock;
445     wp<JavaBBinder> mBinder;
446 };
447 
448 // ----------------------------------------------------------------------------
449 
450 // Per-IBinder death recipient bookkeeping.  This is how we reconcile local jobject
451 // death recipient references passed in through JNI with the permanent corresponding
452 // JavaDeathRecipient objects.
453 
454 class JavaDeathRecipient;
455 
456 class DeathRecipientList : public RefBase {
457     List< sp<JavaDeathRecipient> > mList;
458     Mutex mLock;
459 
460 public:
461     DeathRecipientList();
462     ~DeathRecipientList();
463 
464     void add(const sp<JavaDeathRecipient>& recipient);
465     void remove(const sp<JavaDeathRecipient>& recipient);
466     sp<JavaDeathRecipient> find(jobject recipient);
467 
468     Mutex& lock();  // Use with care; specifically for mutual exclusion during binder death
469 };
470 
471 // ----------------------------------------------------------------------------
472 
473 class JavaDeathRecipient : public IBinder::DeathRecipient
474 {
475 public:
JavaDeathRecipient(JNIEnv * env,jobject object,const sp<DeathRecipientList> & list)476     JavaDeathRecipient(JNIEnv* env, jobject object, const sp<DeathRecipientList>& list)
477         : mVM(jnienv_to_javavm(env)), mObject(env->NewGlobalRef(object)),
478           mObjectWeak(NULL), mList(list)
479     {
480         // These objects manage their own lifetimes so are responsible for final bookkeeping.
481         // The list holds a strong reference to this object.
482         LOGDEATH("Adding JDR %p to DRL %p", this, list.get());
483         list->add(this);
484 
485         gNumDeathRefsCreated.fetch_add(1, std::memory_order_relaxed);
486         gcIfManyNewRefs(env);
487     }
488 
binderDied(const wp<IBinder> & who)489     void binderDied(const wp<IBinder>& who)
490     {
491         LOGDEATH("Receiving binderDied() on JavaDeathRecipient %p\n", this);
492         if (mObject != NULL) {
493             JNIEnv* env = javavm_to_jnienv(mVM);
494 
495             env->CallStaticVoidMethod(gBinderProxyOffsets.mClass,
496                     gBinderProxyOffsets.mSendDeathNotice, mObject);
497             if (env->ExceptionCheck()) {
498                 jthrowable excep = env->ExceptionOccurred();
499                 report_exception(env, excep,
500                         "*** Uncaught exception returned from death notification!");
501             }
502 
503             // Serialize with our containing DeathRecipientList so that we can't
504             // delete the global ref on mObject while the list is being iterated.
505             sp<DeathRecipientList> list = mList.promote();
506             if (list != NULL) {
507                 AutoMutex _l(list->lock());
508 
509                 // Demote from strong ref to weak after binderDied() has been delivered,
510                 // to allow the DeathRecipient and BinderProxy to be GC'd if no longer needed.
511                 mObjectWeak = env->NewWeakGlobalRef(mObject);
512                 env->DeleteGlobalRef(mObject);
513                 mObject = NULL;
514             }
515         }
516     }
517 
clearReference()518     void clearReference()
519     {
520         sp<DeathRecipientList> list = mList.promote();
521         if (list != NULL) {
522             LOGDEATH("Removing JDR %p from DRL %p", this, list.get());
523             list->remove(this);
524         } else {
525             LOGDEATH("clearReference() on JDR %p but DRL wp purged", this);
526         }
527     }
528 
matches(jobject obj)529     bool matches(jobject obj) {
530         bool result;
531         JNIEnv* env = javavm_to_jnienv(mVM);
532 
533         if (mObject != NULL) {
534             result = env->IsSameObject(obj, mObject);
535         } else {
536             ScopedLocalRef<jobject> me(env, env->NewLocalRef(mObjectWeak));
537             result = env->IsSameObject(obj, me.get());
538         }
539         return result;
540     }
541 
warnIfStillLive()542     void warnIfStillLive() {
543         if (mObject != NULL) {
544             // Okay, something is wrong -- we have a hard reference to a live death
545             // recipient on the VM side, but the list is being torn down.
546             JNIEnv* env = javavm_to_jnienv(mVM);
547             ScopedLocalRef<jclass> objClassRef(env, env->GetObjectClass(mObject));
548             ScopedLocalRef<jstring> nameRef(env,
549                     (jstring) env->CallObjectMethod(objClassRef.get(), gClassOffsets.mGetName));
550             ScopedUtfChars nameUtf(env, nameRef.get());
551             if (nameUtf.c_str() != NULL) {
552                 ALOGW("BinderProxy is being destroyed but the application did not call "
553                         "unlinkToDeath to unlink all of its death recipients beforehand.  "
554                         "Releasing leaked death recipient: %s", nameUtf.c_str());
555             } else {
556                 ALOGW("BinderProxy being destroyed; unable to get DR object name");
557                 env->ExceptionClear();
558             }
559         }
560     }
561 
562 protected:
~JavaDeathRecipient()563     virtual ~JavaDeathRecipient()
564     {
565         //ALOGI("Removing death ref: recipient=%p\n", mObject);
566         gNumDeathRefsDeleted.fetch_add(1, std::memory_order_relaxed);
567         JNIEnv* env = javavm_to_jnienv(mVM);
568         if (mObject != NULL) {
569             env->DeleteGlobalRef(mObject);
570         } else {
571             env->DeleteWeakGlobalRef(mObjectWeak);
572         }
573     }
574 
575 private:
576     JavaVM* const mVM;
577     jobject mObject;  // Initial strong ref to Java-side DeathRecipient. Cleared on binderDied().
578     jweak mObjectWeak; // Weak ref to the same Java-side DeathRecipient after binderDied().
579     wp<DeathRecipientList> mList;
580 };
581 
582 // ----------------------------------------------------------------------------
583 
DeathRecipientList()584 DeathRecipientList::DeathRecipientList() {
585     LOGDEATH("New DRL @ %p", this);
586 }
587 
~DeathRecipientList()588 DeathRecipientList::~DeathRecipientList() {
589     LOGDEATH("Destroy DRL @ %p", this);
590     AutoMutex _l(mLock);
591 
592     // Should never happen -- the JavaDeathRecipient objects that have added themselves
593     // to the list are holding references on the list object.  Only when they are torn
594     // down can the list header be destroyed.
595     if (mList.size() > 0) {
596         List< sp<JavaDeathRecipient> >::iterator iter;
597         for (iter = mList.begin(); iter != mList.end(); iter++) {
598             (*iter)->warnIfStillLive();
599         }
600     }
601 }
602 
add(const sp<JavaDeathRecipient> & recipient)603 void DeathRecipientList::add(const sp<JavaDeathRecipient>& recipient) {
604     AutoMutex _l(mLock);
605 
606     LOGDEATH("DRL @ %p : add JDR %p", this, recipient.get());
607     mList.push_back(recipient);
608 }
609 
remove(const sp<JavaDeathRecipient> & recipient)610 void DeathRecipientList::remove(const sp<JavaDeathRecipient>& recipient) {
611     AutoMutex _l(mLock);
612 
613     List< sp<JavaDeathRecipient> >::iterator iter;
614     for (iter = mList.begin(); iter != mList.end(); iter++) {
615         if (*iter == recipient) {
616             LOGDEATH("DRL @ %p : remove JDR %p", this, recipient.get());
617             mList.erase(iter);
618             return;
619         }
620     }
621 }
622 
find(jobject recipient)623 sp<JavaDeathRecipient> DeathRecipientList::find(jobject recipient) {
624     AutoMutex _l(mLock);
625 
626     List< sp<JavaDeathRecipient> >::iterator iter;
627     for (iter = mList.begin(); iter != mList.end(); iter++) {
628         if ((*iter)->matches(recipient)) {
629             return *iter;
630         }
631     }
632     return NULL;
633 }
634 
lock()635 Mutex& DeathRecipientList::lock() {
636     return mLock;
637 }
638 
639 // ----------------------------------------------------------------------------
640 
641 namespace android {
642 
643 // We aggregate native pointer fields for BinderProxy in a single object to allow
644 // management with a single NativeAllocationRegistry, and to reduce the number of JNI
645 // Java field accesses. This costs us some extra indirections here.
646 struct BinderProxyNativeData {
647     // Both fields are constant and not null once javaObjectForIBinder returns this as
648     // part of a BinderProxy.
649 
650     // The native IBinder proxied by this BinderProxy.
651     sp<IBinder> mObject;
652 
653     // Death recipients for mObject. Reference counted only because DeathRecipients
654     // hold a weak reference that can be temporarily promoted.
655     sp<DeathRecipientList> mOrgue;  // Death recipients for mObject.
656 };
657 
getBPNativeData(JNIEnv * env,jobject obj)658 BinderProxyNativeData* getBPNativeData(JNIEnv* env, jobject obj) {
659     return (BinderProxyNativeData *) env->GetLongField(obj, gBinderProxyOffsets.mNativeData);
660 }
661 
662 // If the argument is a JavaBBinder, return the Java object that was used to create it.
663 // Otherwise return a BinderProxy for the IBinder. If a previous call was passed the
664 // same IBinder, and the original BinderProxy is still alive, return the same BinderProxy.
javaObjectForIBinder(JNIEnv * env,const sp<IBinder> & val)665 jobject javaObjectForIBinder(JNIEnv* env, const sp<IBinder>& val)
666 {
667     if (val == NULL) return NULL;
668 
669     if (val->checkSubclass(&gBinderOffsets)) {
670         // It's a JavaBBinder created by ibinderForJavaObject. Already has Java object.
671         jobject object = static_cast<JavaBBinder*>(val.get())->object();
672         LOGDEATH("objectForBinder %p: it's our own %p!\n", val.get(), object);
673         return object;
674     }
675 
676     BinderProxyNativeData* nativeData = new BinderProxyNativeData();
677     nativeData->mOrgue = new DeathRecipientList;
678     nativeData->mObject = val;
679 
680     jobject object = env->CallStaticObjectMethod(gBinderProxyOffsets.mClass,
681             gBinderProxyOffsets.mGetInstance, (jlong) nativeData, (jlong) val.get());
682     if (env->ExceptionCheck()) {
683         // In the exception case, getInstance still took ownership of nativeData.
684         return NULL;
685     }
686     BinderProxyNativeData* actualNativeData = getBPNativeData(env, object);
687     if (actualNativeData == nativeData) {
688         // Created a new Proxy
689         uint32_t numProxies = gNumProxies.fetch_add(1, std::memory_order_relaxed);
690         uint32_t numLastWarned = gProxiesWarned.load(std::memory_order_relaxed);
691         if (numProxies >= numLastWarned + PROXY_WARN_INTERVAL) {
692             // Multiple threads can get here, make sure only one of them gets to
693             // update the warn counter.
694             if (gProxiesWarned.compare_exchange_strong(numLastWarned,
695                         numLastWarned + PROXY_WARN_INTERVAL, std::memory_order_relaxed)) {
696                 ALOGW("Unexpectedly many live BinderProxies: %d\n", numProxies);
697             }
698         }
699     } else {
700         delete nativeData;
701     }
702 
703     return object;
704 }
705 
ibinderForJavaObject(JNIEnv * env,jobject obj)706 sp<IBinder> ibinderForJavaObject(JNIEnv* env, jobject obj)
707 {
708     if (obj == NULL) return NULL;
709 
710     // Instance of Binder?
711     if (env->IsInstanceOf(obj, gBinderOffsets.mClass)) {
712         JavaBBinderHolder* jbh = (JavaBBinderHolder*)
713             env->GetLongField(obj, gBinderOffsets.mObject);
714         return jbh->get(env, obj);
715     }
716 
717     // Instance of BinderProxy?
718     if (env->IsInstanceOf(obj, gBinderProxyOffsets.mClass)) {
719         return getBPNativeData(env, obj)->mObject;
720     }
721 
722     ALOGW("ibinderForJavaObject: %p is not a Binder object", obj);
723     return NULL;
724 }
725 
newParcelFileDescriptor(JNIEnv * env,jobject fileDesc)726 jobject newParcelFileDescriptor(JNIEnv* env, jobject fileDesc)
727 {
728     return env->NewObject(
729             gParcelFileDescriptorOffsets.mClass, gParcelFileDescriptorOffsets.mConstructor, fileDesc);
730 }
731 
set_dalvik_blockguard_policy(JNIEnv * env,jint strict_policy)732 void set_dalvik_blockguard_policy(JNIEnv* env, jint strict_policy)
733 {
734     // Call back into android.os.StrictMode#onBinderStrictModePolicyChange
735     // to sync our state back to it.  See the comments in StrictMode.java.
736     env->CallStaticVoidMethod(gStrictModeCallbackOffsets.mClass,
737                               gStrictModeCallbackOffsets.mCallback,
738                               strict_policy);
739 }
740 
signalExceptionForError(JNIEnv * env,jobject obj,status_t err,bool canThrowRemoteException,int parcelSize)741 void signalExceptionForError(JNIEnv* env, jobject obj, status_t err,
742         bool canThrowRemoteException, int parcelSize)
743 {
744     switch (err) {
745         case UNKNOWN_ERROR:
746             jniThrowException(env, "java/lang/RuntimeException", "Unknown error");
747             break;
748         case NO_MEMORY:
749             jniThrowException(env, "java/lang/OutOfMemoryError", NULL);
750             break;
751         case INVALID_OPERATION:
752             jniThrowException(env, "java/lang/UnsupportedOperationException", NULL);
753             break;
754         case BAD_VALUE:
755             jniThrowException(env, "java/lang/IllegalArgumentException", NULL);
756             break;
757         case BAD_INDEX:
758             jniThrowException(env, "java/lang/IndexOutOfBoundsException", NULL);
759             break;
760         case BAD_TYPE:
761             jniThrowException(env, "java/lang/IllegalArgumentException", NULL);
762             break;
763         case NAME_NOT_FOUND:
764             jniThrowException(env, "java/util/NoSuchElementException", NULL);
765             break;
766         case PERMISSION_DENIED:
767             jniThrowException(env, "java/lang/SecurityException", NULL);
768             break;
769         case NOT_ENOUGH_DATA:
770             jniThrowException(env, "android/os/ParcelFormatException", "Not enough data");
771             break;
772         case NO_INIT:
773             jniThrowException(env, "java/lang/RuntimeException", "Not initialized");
774             break;
775         case ALREADY_EXISTS:
776             jniThrowException(env, "java/lang/RuntimeException", "Item already exists");
777             break;
778         case DEAD_OBJECT:
779             // DeadObjectException is a checked exception, only throw from certain methods.
780             jniThrowException(env, canThrowRemoteException
781                     ? "android/os/DeadObjectException"
782                             : "java/lang/RuntimeException", NULL);
783             break;
784         case UNKNOWN_TRANSACTION:
785             jniThrowException(env, "java/lang/RuntimeException", "Unknown transaction code");
786             break;
787         case FAILED_TRANSACTION: {
788             ALOGE("!!! FAILED BINDER TRANSACTION !!!  (parcel size = %d)", parcelSize);
789             const char* exceptionToThrow;
790             char msg[128];
791             // TransactionTooLargeException is a checked exception, only throw from certain methods.
792             // FIXME: Transaction too large is the most common reason for FAILED_TRANSACTION
793             //        but it is not the only one.  The Binder driver can return BR_FAILED_REPLY
794             //        for other reasons also, such as if the transaction is malformed or
795             //        refers to an FD that has been closed.  We should change the driver
796             //        to enable us to distinguish these cases in the future.
797             if (canThrowRemoteException && parcelSize > 200*1024) {
798                 // bona fide large payload
799                 exceptionToThrow = "android/os/TransactionTooLargeException";
800                 snprintf(msg, sizeof(msg)-1, "data parcel size %d bytes", parcelSize);
801             } else {
802                 // Heuristic: a payload smaller than this threshold "shouldn't" be too
803                 // big, so it's probably some other, more subtle problem.  In practice
804                 // it seems to always mean that the remote process died while the binder
805                 // transaction was already in flight.
806                 exceptionToThrow = (canThrowRemoteException)
807                         ? "android/os/DeadObjectException"
808                         : "java/lang/RuntimeException";
809                 snprintf(msg, sizeof(msg)-1,
810                         "Transaction failed on small parcel; remote process probably died");
811             }
812             jniThrowException(env, exceptionToThrow, msg);
813         } break;
814         case FDS_NOT_ALLOWED:
815             jniThrowException(env, "java/lang/RuntimeException",
816                     "Not allowed to write file descriptors here");
817             break;
818         case UNEXPECTED_NULL:
819             jniThrowNullPointerException(env, NULL);
820             break;
821         case -EBADF:
822             jniThrowException(env, "java/lang/RuntimeException",
823                     "Bad file descriptor");
824             break;
825         case -ENFILE:
826             jniThrowException(env, "java/lang/RuntimeException",
827                     "File table overflow");
828             break;
829         case -EMFILE:
830             jniThrowException(env, "java/lang/RuntimeException",
831                     "Too many open files");
832             break;
833         case -EFBIG:
834             jniThrowException(env, "java/lang/RuntimeException",
835                     "File too large");
836             break;
837         case -ENOSPC:
838             jniThrowException(env, "java/lang/RuntimeException",
839                     "No space left on device");
840             break;
841         case -ESPIPE:
842             jniThrowException(env, "java/lang/RuntimeException",
843                     "Illegal seek");
844             break;
845         case -EROFS:
846             jniThrowException(env, "java/lang/RuntimeException",
847                     "Read-only file system");
848             break;
849         case -EMLINK:
850             jniThrowException(env, "java/lang/RuntimeException",
851                     "Too many links");
852             break;
853         default:
854             ALOGE("Unknown binder error code. 0x%" PRIx32, err);
855             String8 msg;
856             msg.appendFormat("Unknown binder error code. 0x%" PRIx32, err);
857             // RemoteException is a checked exception, only throw from certain methods.
858             jniThrowException(env, canThrowRemoteException
859                     ? "android/os/RemoteException" : "java/lang/RuntimeException", msg.string());
860             break;
861     }
862 }
863 
864 }
865 
866 // ----------------------------------------------------------------------------
867 
android_os_Binder_getCallingPid()868 static jint android_os_Binder_getCallingPid()
869 {
870     return IPCThreadState::self()->getCallingPid();
871 }
872 
android_os_Binder_getCallingUid()873 static jint android_os_Binder_getCallingUid()
874 {
875     return IPCThreadState::self()->getCallingUid();
876 }
877 
android_os_Binder_isHandlingTransaction()878 static jboolean android_os_Binder_isHandlingTransaction()
879 {
880     return IPCThreadState::self()->isServingCall();
881 }
882 
android_os_Binder_clearCallingIdentity()883 static jlong android_os_Binder_clearCallingIdentity()
884 {
885     return IPCThreadState::self()->clearCallingIdentity();
886 }
887 
android_os_Binder_restoreCallingIdentity(JNIEnv * env,jobject clazz,jlong token)888 static void android_os_Binder_restoreCallingIdentity(JNIEnv* env, jobject clazz, jlong token)
889 {
890     // XXX temporary sanity check to debug crashes.
891     int uid = (int)(token>>32);
892     if (uid > 0 && uid < 999) {
893         // In Android currently there are no uids in this range.
894         char buf[128];
895         sprintf(buf, "Restoring bad calling ident: 0x%" PRIx64, token);
896         jniThrowException(env, "java/lang/IllegalStateException", buf);
897         return;
898     }
899     IPCThreadState::self()->restoreCallingIdentity(token);
900 }
901 
android_os_Binder_setThreadStrictModePolicy(jint policyMask)902 static void android_os_Binder_setThreadStrictModePolicy(jint policyMask)
903 {
904     IPCThreadState::self()->setStrictModePolicy(policyMask);
905 }
906 
android_os_Binder_getThreadStrictModePolicy()907 static jint android_os_Binder_getThreadStrictModePolicy()
908 {
909     return IPCThreadState::self()->getStrictModePolicy();
910 }
911 
android_os_Binder_setCallingWorkSourceUid(jint workSource)912 static jlong android_os_Binder_setCallingWorkSourceUid(jint workSource)
913 {
914     return IPCThreadState::self()->setCallingWorkSourceUid(workSource);
915 }
916 
android_os_Binder_getCallingWorkSourceUid()917 static jlong android_os_Binder_getCallingWorkSourceUid()
918 {
919     return IPCThreadState::self()->getCallingWorkSourceUid();
920 }
921 
android_os_Binder_clearCallingWorkSource()922 static jlong android_os_Binder_clearCallingWorkSource()
923 {
924     return IPCThreadState::self()->clearCallingWorkSource();
925 }
926 
android_os_Binder_restoreCallingWorkSource(jlong token)927 static void android_os_Binder_restoreCallingWorkSource(jlong token)
928 {
929     IPCThreadState::self()->restoreCallingWorkSource(token);
930 }
931 
android_os_Binder_flushPendingCommands(JNIEnv * env,jobject clazz)932 static void android_os_Binder_flushPendingCommands(JNIEnv* env, jobject clazz)
933 {
934     IPCThreadState::self()->flushCommands();
935 }
936 
android_os_Binder_getNativeBBinderHolder(JNIEnv * env,jobject clazz)937 static jlong android_os_Binder_getNativeBBinderHolder(JNIEnv* env, jobject clazz)
938 {
939     JavaBBinderHolder* jbh = new JavaBBinderHolder();
940     return (jlong) jbh;
941 }
942 
Binder_destroy(void * rawJbh)943 static void Binder_destroy(void* rawJbh)
944 {
945     JavaBBinderHolder* jbh = (JavaBBinderHolder*) rawJbh;
946     ALOGV("Java Binder: deleting holder %p", jbh);
947     delete jbh;
948 }
949 
android_os_Binder_getNativeFinalizer(JNIEnv *,jclass)950 JNIEXPORT jlong JNICALL android_os_Binder_getNativeFinalizer(JNIEnv*, jclass) {
951     return (jlong) Binder_destroy;
952 }
953 
android_os_Binder_blockUntilThreadAvailable(JNIEnv * env,jobject clazz)954 static void android_os_Binder_blockUntilThreadAvailable(JNIEnv* env, jobject clazz)
955 {
956     return IPCThreadState::self()->blockUntilThreadAvailable();
957 }
958 
959 // ----------------------------------------------------------------------------
960 
961 static const JNINativeMethod gBinderMethods[] = {
962      /* name, signature, funcPtr */
963     // @CriticalNative
964     { "getCallingPid", "()I", (void*)android_os_Binder_getCallingPid },
965     // @CriticalNative
966     { "getCallingUid", "()I", (void*)android_os_Binder_getCallingUid },
967     // @CriticalNative
968     { "isHandlingTransaction", "()Z", (void*)android_os_Binder_isHandlingTransaction },
969     // @CriticalNative
970     { "clearCallingIdentity", "()J", (void*)android_os_Binder_clearCallingIdentity },
971     { "restoreCallingIdentity", "(J)V", (void*)android_os_Binder_restoreCallingIdentity },
972     // @CriticalNative
973     { "setThreadStrictModePolicy", "(I)V", (void*)android_os_Binder_setThreadStrictModePolicy },
974     // @CriticalNative
975     { "getThreadStrictModePolicy", "()I", (void*)android_os_Binder_getThreadStrictModePolicy },
976     // @CriticalNative
977     { "setCallingWorkSourceUid", "(I)J", (void*)android_os_Binder_setCallingWorkSourceUid },
978     // @CriticalNative
979     { "getCallingWorkSourceUid", "()I", (void*)android_os_Binder_getCallingWorkSourceUid },
980     // @CriticalNative
981     { "clearCallingWorkSource", "()J", (void*)android_os_Binder_clearCallingWorkSource },
982     { "restoreCallingWorkSource", "(J)V", (void*)android_os_Binder_restoreCallingWorkSource },
983     { "flushPendingCommands", "()V", (void*)android_os_Binder_flushPendingCommands },
984     { "getNativeBBinderHolder", "()J", (void*)android_os_Binder_getNativeBBinderHolder },
985     { "getNativeFinalizer", "()J", (void*)android_os_Binder_getNativeFinalizer },
986     { "blockUntilThreadAvailable", "()V", (void*)android_os_Binder_blockUntilThreadAvailable }
987 };
988 
989 const char* const kBinderPathName = "android/os/Binder";
990 
int_register_android_os_Binder(JNIEnv * env)991 static int int_register_android_os_Binder(JNIEnv* env)
992 {
993     jclass clazz = FindClassOrDie(env, kBinderPathName);
994 
995     gBinderOffsets.mClass = MakeGlobalRefOrDie(env, clazz);
996     gBinderOffsets.mExecTransact = GetMethodIDOrDie(env, clazz, "execTransact", "(IJJI)Z");
997     gBinderOffsets.mGetInterfaceDescriptor = GetMethodIDOrDie(env, clazz, "getInterfaceDescriptor",
998         "()Ljava/lang/String;");
999     gBinderOffsets.mObject = GetFieldIDOrDie(env, clazz, "mObject", "J");
1000 
1001     return RegisterMethodsOrDie(
1002         env, kBinderPathName,
1003         gBinderMethods, NELEM(gBinderMethods));
1004 }
1005 
1006 // ****************************************************************************
1007 // ****************************************************************************
1008 // ****************************************************************************
1009 
1010 namespace android {
1011 
android_os_Debug_getLocalObjectCount(JNIEnv * env,jobject clazz)1012 jint android_os_Debug_getLocalObjectCount(JNIEnv* env, jobject clazz)
1013 {
1014     return gNumLocalRefsCreated - gNumLocalRefsDeleted;
1015 }
1016 
android_os_Debug_getProxyObjectCount(JNIEnv * env,jobject clazz)1017 jint android_os_Debug_getProxyObjectCount(JNIEnv* env, jobject clazz)
1018 {
1019     return gNumProxies.load();
1020 }
1021 
android_os_Debug_getDeathObjectCount(JNIEnv * env,jobject clazz)1022 jint android_os_Debug_getDeathObjectCount(JNIEnv* env, jobject clazz)
1023 {
1024     return gNumDeathRefsCreated - gNumDeathRefsDeleted;
1025 }
1026 
1027 }
1028 
1029 // ****************************************************************************
1030 // ****************************************************************************
1031 // ****************************************************************************
1032 
android_os_BinderInternal_getContextObject(JNIEnv * env,jobject clazz)1033 static jobject android_os_BinderInternal_getContextObject(JNIEnv* env, jobject clazz)
1034 {
1035     sp<IBinder> b = ProcessState::self()->getContextObject(NULL);
1036     return javaObjectForIBinder(env, b);
1037 }
1038 
android_os_BinderInternal_joinThreadPool(JNIEnv * env,jobject clazz)1039 static void android_os_BinderInternal_joinThreadPool(JNIEnv* env, jobject clazz)
1040 {
1041     sp<IBinder> b = ProcessState::self()->getContextObject(NULL);
1042     android::IPCThreadState::self()->joinThreadPool();
1043 }
1044 
android_os_BinderInternal_disableBackgroundScheduling(JNIEnv * env,jobject clazz,jboolean disable)1045 static void android_os_BinderInternal_disableBackgroundScheduling(JNIEnv* env,
1046         jobject clazz, jboolean disable)
1047 {
1048     IPCThreadState::disableBackgroundScheduling(disable ? true : false);
1049 }
1050 
android_os_BinderInternal_setMaxThreads(JNIEnv * env,jobject clazz,jint maxThreads)1051 static void android_os_BinderInternal_setMaxThreads(JNIEnv* env,
1052         jobject clazz, jint maxThreads)
1053 {
1054     ProcessState::self()->setThreadPoolMaxThreadCount(maxThreads);
1055 }
1056 
android_os_BinderInternal_handleGc(JNIEnv * env,jobject clazz)1057 static void android_os_BinderInternal_handleGc(JNIEnv* env, jobject clazz)
1058 {
1059     ALOGV("Gc has executed, updating Refs count at GC");
1060     gCollectedAtRefs = gNumLocalRefsCreated + gNumDeathRefsCreated;
1061 }
1062 
android_os_BinderInternal_proxyLimitcallback(int uid)1063 static void android_os_BinderInternal_proxyLimitcallback(int uid)
1064 {
1065     JNIEnv *env = AndroidRuntime::getJNIEnv();
1066     env->CallStaticVoidMethod(gBinderInternalOffsets.mClass,
1067                               gBinderInternalOffsets.mProxyLimitCallback,
1068                               uid);
1069 
1070     if (env->ExceptionCheck()) {
1071         ScopedLocalRef<jthrowable> excep(env, env->ExceptionOccurred());
1072         report_exception(env, excep.get(),
1073             "*** Uncaught exception in binderProxyLimitCallbackFromNative");
1074     }
1075 }
1076 
android_os_BinderInternal_setBinderProxyCountEnabled(JNIEnv * env,jobject clazz,jboolean enable)1077 static void android_os_BinderInternal_setBinderProxyCountEnabled(JNIEnv* env, jobject clazz,
1078                                                                  jboolean enable)
1079 {
1080     BpBinder::setCountByUidEnabled((bool) enable);
1081 }
1082 
android_os_BinderInternal_getBinderProxyPerUidCounts(JNIEnv * env,jclass clazz)1083 static jobject android_os_BinderInternal_getBinderProxyPerUidCounts(JNIEnv* env, jclass clazz)
1084 {
1085     Vector<uint32_t> uids, counts;
1086     BpBinder::getCountByUid(uids, counts);
1087     jobject sparseIntArray = env->NewObject(gSparseIntArrayOffsets.classObject,
1088                                             gSparseIntArrayOffsets.constructor);
1089     for (size_t i = 0; i < uids.size(); i++) {
1090         env->CallVoidMethod(sparseIntArray, gSparseIntArrayOffsets.put,
1091                             static_cast<jint>(uids[i]), static_cast<jint>(counts[i]));
1092     }
1093     return sparseIntArray;
1094 }
1095 
android_os_BinderInternal_getBinderProxyCount(JNIEnv * env,jobject clazz,jint uid)1096 static jint android_os_BinderInternal_getBinderProxyCount(JNIEnv* env, jobject clazz, jint uid) {
1097     return static_cast<jint>(BpBinder::getBinderProxyCount(static_cast<uint32_t>(uid)));
1098 }
1099 
android_os_BinderInternal_setBinderProxyCountWatermarks(JNIEnv * env,jobject clazz,jint high,jint low)1100 static void android_os_BinderInternal_setBinderProxyCountWatermarks(JNIEnv* env, jobject clazz,
1101                                                                     jint high, jint low)
1102 {
1103     BpBinder::setBinderProxyCountWatermarks(high, low);
1104 }
1105 
1106 // ----------------------------------------------------------------------------
1107 
1108 static const JNINativeMethod gBinderInternalMethods[] = {
1109      /* name, signature, funcPtr */
1110     { "getContextObject", "()Landroid/os/IBinder;", (void*)android_os_BinderInternal_getContextObject },
1111     { "joinThreadPool", "()V", (void*)android_os_BinderInternal_joinThreadPool },
1112     { "disableBackgroundScheduling", "(Z)V", (void*)android_os_BinderInternal_disableBackgroundScheduling },
1113     { "setMaxThreads", "(I)V", (void*)android_os_BinderInternal_setMaxThreads },
1114     { "handleGc", "()V", (void*)android_os_BinderInternal_handleGc },
1115     { "nSetBinderProxyCountEnabled", "(Z)V", (void*)android_os_BinderInternal_setBinderProxyCountEnabled },
1116     { "nGetBinderProxyPerUidCounts", "()Landroid/util/SparseIntArray;", (void*)android_os_BinderInternal_getBinderProxyPerUidCounts },
1117     { "nGetBinderProxyCount", "(I)I", (void*)android_os_BinderInternal_getBinderProxyCount },
1118     { "nSetBinderProxyCountWatermarks", "(II)V", (void*)android_os_BinderInternal_setBinderProxyCountWatermarks}
1119 };
1120 
1121 const char* const kBinderInternalPathName = "com/android/internal/os/BinderInternal";
1122 
int_register_android_os_BinderInternal(JNIEnv * env)1123 static int int_register_android_os_BinderInternal(JNIEnv* env)
1124 {
1125     jclass clazz = FindClassOrDie(env, kBinderInternalPathName);
1126 
1127     gBinderInternalOffsets.mClass = MakeGlobalRefOrDie(env, clazz);
1128     gBinderInternalOffsets.mForceGc = GetStaticMethodIDOrDie(env, clazz, "forceBinderGc", "()V");
1129     gBinderInternalOffsets.mProxyLimitCallback = GetStaticMethodIDOrDie(env, clazz, "binderProxyLimitCallbackFromNative", "(I)V");
1130 
1131     jclass SparseIntArrayClass = FindClassOrDie(env, "android/util/SparseIntArray");
1132     gSparseIntArrayOffsets.classObject = MakeGlobalRefOrDie(env, SparseIntArrayClass);
1133     gSparseIntArrayOffsets.constructor = GetMethodIDOrDie(env, gSparseIntArrayOffsets.classObject,
1134                                                            "<init>", "()V");
1135     gSparseIntArrayOffsets.put = GetMethodIDOrDie(env, gSparseIntArrayOffsets.classObject, "put",
1136                                                    "(II)V");
1137 
1138     BpBinder::setLimitCallback(android_os_BinderInternal_proxyLimitcallback);
1139 
1140     return RegisterMethodsOrDie(
1141         env, kBinderInternalPathName,
1142         gBinderInternalMethods, NELEM(gBinderInternalMethods));
1143 }
1144 
1145 // ****************************************************************************
1146 // ****************************************************************************
1147 // ****************************************************************************
1148 
android_os_BinderProxy_pingBinder(JNIEnv * env,jobject obj)1149 static jboolean android_os_BinderProxy_pingBinder(JNIEnv* env, jobject obj)
1150 {
1151     IBinder* target = getBPNativeData(env, obj)->mObject.get();
1152     if (target == NULL) {
1153         return JNI_FALSE;
1154     }
1155     status_t err = target->pingBinder();
1156     return err == NO_ERROR ? JNI_TRUE : JNI_FALSE;
1157 }
1158 
android_os_BinderProxy_getInterfaceDescriptor(JNIEnv * env,jobject obj)1159 static jstring android_os_BinderProxy_getInterfaceDescriptor(JNIEnv* env, jobject obj)
1160 {
1161     IBinder* target = getBPNativeData(env, obj)->mObject.get();
1162     if (target != NULL) {
1163         const String16& desc = target->getInterfaceDescriptor();
1164         return env->NewString(reinterpret_cast<const jchar*>(desc.string()),
1165                               desc.size());
1166     }
1167     jniThrowException(env, "java/lang/RuntimeException",
1168             "No binder found for object");
1169     return NULL;
1170 }
1171 
android_os_BinderProxy_isBinderAlive(JNIEnv * env,jobject obj)1172 static jboolean android_os_BinderProxy_isBinderAlive(JNIEnv* env, jobject obj)
1173 {
1174     IBinder* target = getBPNativeData(env, obj)->mObject.get();
1175     if (target == NULL) {
1176         return JNI_FALSE;
1177     }
1178     bool alive = target->isBinderAlive();
1179     return alive ? JNI_TRUE : JNI_FALSE;
1180 }
1181 
getprocname(pid_t pid,char * buf,size_t len)1182 static int getprocname(pid_t pid, char *buf, size_t len) {
1183     char filename[32];
1184     FILE *f;
1185 
1186     snprintf(filename, sizeof(filename), "/proc/%d/cmdline", pid);
1187     f = fopen(filename, "re");
1188     if (!f) {
1189         *buf = '\0';
1190         return 1;
1191     }
1192     if (!fgets(buf, len, f)) {
1193         *buf = '\0';
1194         fclose(f);
1195         return 2;
1196     }
1197     fclose(f);
1198     return 0;
1199 }
1200 
push_eventlog_string(char ** pos,const char * end,const char * str)1201 static bool push_eventlog_string(char** pos, const char* end, const char* str) {
1202     jint len = strlen(str);
1203     int space_needed = 1 + sizeof(len) + len;
1204     if (end - *pos < space_needed) {
1205         ALOGW("not enough space for string. remain=%" PRIdPTR "; needed=%d",
1206              end - *pos, space_needed);
1207         return false;
1208     }
1209     **pos = EVENT_TYPE_STRING;
1210     (*pos)++;
1211     memcpy(*pos, &len, sizeof(len));
1212     *pos += sizeof(len);
1213     memcpy(*pos, str, len);
1214     *pos += len;
1215     return true;
1216 }
1217 
push_eventlog_int(char ** pos,const char * end,jint val)1218 static bool push_eventlog_int(char** pos, const char* end, jint val) {
1219     int space_needed = 1 + sizeof(val);
1220     if (end - *pos < space_needed) {
1221         ALOGW("not enough space for int.  remain=%" PRIdPTR "; needed=%d",
1222              end - *pos, space_needed);
1223         return false;
1224     }
1225     **pos = EVENT_TYPE_INT;
1226     (*pos)++;
1227     memcpy(*pos, &val, sizeof(val));
1228     *pos += sizeof(val);
1229     return true;
1230 }
1231 
1232 // From frameworks/base/core/java/android/content/EventLogTags.logtags:
1233 
1234 static const bool kEnableBinderSample = false;
1235 
1236 #define LOGTAG_BINDER_OPERATION 52004
1237 
conditionally_log_binder_call(int64_t start_millis,IBinder * target,jint code)1238 static void conditionally_log_binder_call(int64_t start_millis,
1239                                           IBinder* target, jint code) {
1240     int duration_ms = static_cast<int>(uptimeMillis() - start_millis);
1241 
1242     int sample_percent;
1243     if (duration_ms >= 500) {
1244         sample_percent = 100;
1245     } else {
1246         sample_percent = 100 * duration_ms / 500;
1247         if (sample_percent == 0) {
1248             return;
1249         }
1250         if (sample_percent < (random() % 100 + 1)) {
1251             return;
1252         }
1253     }
1254 
1255     char process_name[40];
1256     getprocname(getpid(), process_name, sizeof(process_name));
1257     String8 desc(target->getInterfaceDescriptor());
1258 
1259     char buf[LOGGER_ENTRY_MAX_PAYLOAD];
1260     buf[0] = EVENT_TYPE_LIST;
1261     buf[1] = 5;
1262     char* pos = &buf[2];
1263     char* end = &buf[LOGGER_ENTRY_MAX_PAYLOAD - 1];  // leave room for final \n
1264     if (!push_eventlog_string(&pos, end, desc.string())) return;
1265     if (!push_eventlog_int(&pos, end, code)) return;
1266     if (!push_eventlog_int(&pos, end, duration_ms)) return;
1267     if (!push_eventlog_string(&pos, end, process_name)) return;
1268     if (!push_eventlog_int(&pos, end, sample_percent)) return;
1269     *(pos++) = '\n';   // conventional with EVENT_TYPE_LIST apparently.
1270     android_bWriteLog(LOGTAG_BINDER_OPERATION, buf, pos - buf);
1271 }
1272 
1273 // We only measure binder call durations to potentially log them if
1274 // we're on the main thread.
should_time_binder_calls()1275 static bool should_time_binder_calls() {
1276   return (getpid() == gettid());
1277 }
1278 
android_os_BinderProxy_transact(JNIEnv * env,jobject obj,jint code,jobject dataObj,jobject replyObj,jint flags)1279 static jboolean android_os_BinderProxy_transact(JNIEnv* env, jobject obj,
1280         jint code, jobject dataObj, jobject replyObj, jint flags) // throws RemoteException
1281 {
1282     if (dataObj == NULL) {
1283         jniThrowNullPointerException(env, NULL);
1284         return JNI_FALSE;
1285     }
1286 
1287     Parcel* data = parcelForJavaObject(env, dataObj);
1288     if (data == NULL) {
1289         return JNI_FALSE;
1290     }
1291     Parcel* reply = parcelForJavaObject(env, replyObj);
1292     if (reply == NULL && replyObj != NULL) {
1293         return JNI_FALSE;
1294     }
1295 
1296     IBinder* target = getBPNativeData(env, obj)->mObject.get();
1297     if (target == NULL) {
1298         jniThrowException(env, "java/lang/IllegalStateException", "Binder has been finalized!");
1299         return JNI_FALSE;
1300     }
1301 
1302     ALOGV("Java code calling transact on %p in Java object %p with code %" PRId32 "\n",
1303             target, obj, code);
1304 
1305 
1306     bool time_binder_calls;
1307     int64_t start_millis;
1308     if (kEnableBinderSample) {
1309         // Only log the binder call duration for things on the Java-level main thread.
1310         // But if we don't
1311         time_binder_calls = should_time_binder_calls();
1312 
1313         if (time_binder_calls) {
1314             start_millis = uptimeMillis();
1315         }
1316     }
1317 
1318     //printf("Transact from Java code to %p sending: ", target); data->print();
1319     status_t err = target->transact(code, *data, reply, flags);
1320     //if (reply) printf("Transact from Java code to %p received: ", target); reply->print();
1321 
1322     if (kEnableBinderSample) {
1323         if (time_binder_calls) {
1324             conditionally_log_binder_call(start_millis, target, code);
1325         }
1326     }
1327 
1328     if (err == NO_ERROR) {
1329         return JNI_TRUE;
1330     } else if (err == UNKNOWN_TRANSACTION) {
1331         return JNI_FALSE;
1332     }
1333 
1334     signalExceptionForError(env, obj, err, true /*canThrowRemoteException*/, data->dataSize());
1335     return JNI_FALSE;
1336 }
1337 
android_os_BinderProxy_linkToDeath(JNIEnv * env,jobject obj,jobject recipient,jint flags)1338 static void android_os_BinderProxy_linkToDeath(JNIEnv* env, jobject obj,
1339         jobject recipient, jint flags) // throws RemoteException
1340 {
1341     if (recipient == NULL) {
1342         jniThrowNullPointerException(env, NULL);
1343         return;
1344     }
1345 
1346     BinderProxyNativeData *nd = getBPNativeData(env, obj);
1347     IBinder* target = nd->mObject.get();
1348 
1349     LOGDEATH("linkToDeath: binder=%p recipient=%p\n", target, recipient);
1350 
1351     if (!target->localBinder()) {
1352         DeathRecipientList* list = nd->mOrgue.get();
1353         sp<JavaDeathRecipient> jdr = new JavaDeathRecipient(env, recipient, list);
1354         status_t err = target->linkToDeath(jdr, NULL, flags);
1355         if (err != NO_ERROR) {
1356             // Failure adding the death recipient, so clear its reference
1357             // now.
1358             jdr->clearReference();
1359             signalExceptionForError(env, obj, err, true /*canThrowRemoteException*/);
1360         }
1361     }
1362 }
1363 
android_os_BinderProxy_unlinkToDeath(JNIEnv * env,jobject obj,jobject recipient,jint flags)1364 static jboolean android_os_BinderProxy_unlinkToDeath(JNIEnv* env, jobject obj,
1365                                                  jobject recipient, jint flags)
1366 {
1367     jboolean res = JNI_FALSE;
1368     if (recipient == NULL) {
1369         jniThrowNullPointerException(env, NULL);
1370         return res;
1371     }
1372 
1373     BinderProxyNativeData* nd = getBPNativeData(env, obj);
1374     IBinder* target = nd->mObject.get();
1375     if (target == NULL) {
1376         ALOGW("Binder has been finalized when calling linkToDeath() with recip=%p)\n", recipient);
1377         return JNI_FALSE;
1378     }
1379 
1380     LOGDEATH("unlinkToDeath: binder=%p recipient=%p\n", target, recipient);
1381 
1382     if (!target->localBinder()) {
1383         status_t err = NAME_NOT_FOUND;
1384 
1385         // If we find the matching recipient, proceed to unlink using that
1386         DeathRecipientList* list = nd->mOrgue.get();
1387         sp<JavaDeathRecipient> origJDR = list->find(recipient);
1388         LOGDEATH("   unlink found list %p and JDR %p", list, origJDR.get());
1389         if (origJDR != NULL) {
1390             wp<IBinder::DeathRecipient> dr;
1391             err = target->unlinkToDeath(origJDR, NULL, flags, &dr);
1392             if (err == NO_ERROR && dr != NULL) {
1393                 sp<IBinder::DeathRecipient> sdr = dr.promote();
1394                 JavaDeathRecipient* jdr = static_cast<JavaDeathRecipient*>(sdr.get());
1395                 if (jdr != NULL) {
1396                     jdr->clearReference();
1397                 }
1398             }
1399         }
1400 
1401         if (err == NO_ERROR || err == DEAD_OBJECT) {
1402             res = JNI_TRUE;
1403         } else {
1404             jniThrowException(env, "java/util/NoSuchElementException",
1405                               "Death link does not exist");
1406         }
1407     }
1408 
1409     return res;
1410 }
1411 
BinderProxy_destroy(void * rawNativeData)1412 static void BinderProxy_destroy(void* rawNativeData)
1413 {
1414     BinderProxyNativeData * nativeData = (BinderProxyNativeData *) rawNativeData;
1415     LOGDEATH("Destroying BinderProxy: binder=%p drl=%p\n",
1416             nativeData->mObject.get(), nativeData->mOrgue.get());
1417     delete nativeData;
1418     IPCThreadState::self()->flushCommands();
1419     --gNumProxies;
1420 }
1421 
android_os_BinderProxy_getNativeFinalizer(JNIEnv *,jclass)1422 JNIEXPORT jlong JNICALL android_os_BinderProxy_getNativeFinalizer(JNIEnv*, jclass) {
1423     return (jlong) BinderProxy_destroy;
1424 }
1425 
1426 // ----------------------------------------------------------------------------
1427 
1428 static const JNINativeMethod gBinderProxyMethods[] = {
1429      /* name, signature, funcPtr */
1430     {"pingBinder",          "()Z", (void*)android_os_BinderProxy_pingBinder},
1431     {"isBinderAlive",       "()Z", (void*)android_os_BinderProxy_isBinderAlive},
1432     {"getInterfaceDescriptor", "()Ljava/lang/String;", (void*)android_os_BinderProxy_getInterfaceDescriptor},
1433     {"transactNative",      "(ILandroid/os/Parcel;Landroid/os/Parcel;I)Z", (void*)android_os_BinderProxy_transact},
1434     {"linkToDeath",         "(Landroid/os/IBinder$DeathRecipient;I)V", (void*)android_os_BinderProxy_linkToDeath},
1435     {"unlinkToDeath",       "(Landroid/os/IBinder$DeathRecipient;I)Z", (void*)android_os_BinderProxy_unlinkToDeath},
1436     {"getNativeFinalizer",  "()J", (void*)android_os_BinderProxy_getNativeFinalizer},
1437 };
1438 
1439 const char* const kBinderProxyPathName = "android/os/BinderProxy";
1440 
int_register_android_os_BinderProxy(JNIEnv * env)1441 static int int_register_android_os_BinderProxy(JNIEnv* env)
1442 {
1443     jclass clazz = FindClassOrDie(env, "java/lang/Error");
1444     gErrorOffsets.mClass = MakeGlobalRefOrDie(env, clazz);
1445 
1446     clazz = FindClassOrDie(env, kBinderProxyPathName);
1447     gBinderProxyOffsets.mClass = MakeGlobalRefOrDie(env, clazz);
1448     gBinderProxyOffsets.mGetInstance = GetStaticMethodIDOrDie(env, clazz, "getInstance",
1449             "(JJ)Landroid/os/BinderProxy;");
1450     gBinderProxyOffsets.mSendDeathNotice = GetStaticMethodIDOrDie(env, clazz, "sendDeathNotice",
1451             "(Landroid/os/IBinder$DeathRecipient;)V");
1452     gBinderProxyOffsets.mNativeData = GetFieldIDOrDie(env, clazz, "mNativeData", "J");
1453 
1454     clazz = FindClassOrDie(env, "java/lang/Class");
1455     gClassOffsets.mGetName = GetMethodIDOrDie(env, clazz, "getName", "()Ljava/lang/String;");
1456 
1457     return RegisterMethodsOrDie(
1458         env, kBinderProxyPathName,
1459         gBinderProxyMethods, NELEM(gBinderProxyMethods));
1460 }
1461 
1462 // ****************************************************************************
1463 // ****************************************************************************
1464 // ****************************************************************************
1465 
register_android_os_Binder(JNIEnv * env)1466 int register_android_os_Binder(JNIEnv* env)
1467 {
1468     if (int_register_android_os_Binder(env) < 0)
1469         return -1;
1470     if (int_register_android_os_BinderInternal(env) < 0)
1471         return -1;
1472     if (int_register_android_os_BinderProxy(env) < 0)
1473         return -1;
1474 
1475     jclass clazz = FindClassOrDie(env, "android/util/Log");
1476     gLogOffsets.mClass = MakeGlobalRefOrDie(env, clazz);
1477     gLogOffsets.mLogE = GetStaticMethodIDOrDie(env, clazz, "e",
1478             "(Ljava/lang/String;Ljava/lang/String;Ljava/lang/Throwable;)I");
1479 
1480     clazz = FindClassOrDie(env, "android/os/ParcelFileDescriptor");
1481     gParcelFileDescriptorOffsets.mClass = MakeGlobalRefOrDie(env, clazz);
1482     gParcelFileDescriptorOffsets.mConstructor = GetMethodIDOrDie(env, clazz, "<init>",
1483                                                                  "(Ljava/io/FileDescriptor;)V");
1484 
1485     clazz = FindClassOrDie(env, "android/os/StrictMode");
1486     gStrictModeCallbackOffsets.mClass = MakeGlobalRefOrDie(env, clazz);
1487     gStrictModeCallbackOffsets.mCallback = GetStaticMethodIDOrDie(env, clazz,
1488             "onBinderStrictModePolicyChange", "(I)V");
1489 
1490     clazz = FindClassOrDie(env, "java/lang/Thread");
1491     gThreadDispatchOffsets.mClass = MakeGlobalRefOrDie(env, clazz);
1492     gThreadDispatchOffsets.mDispatchUncaughtException = GetMethodIDOrDie(env, clazz,
1493             "dispatchUncaughtException", "(Ljava/lang/Throwable;)V");
1494     gThreadDispatchOffsets.mCurrentThread = GetStaticMethodIDOrDie(env, clazz, "currentThread",
1495             "()Ljava/lang/Thread;");
1496 
1497     return 0;
1498 }
1499