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1 /*
2  * Copyright (C) 2005 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 "IPCThreadState"
18 
19 #include <binder/IPCThreadState.h>
20 
21 #include <binder/Binder.h>
22 #include <binder/BpBinder.h>
23 #include <binder/TextOutput.h>
24 
25 #include <cutils/sched_policy.h>
26 #include <utils/Log.h>
27 #include <utils/SystemClock.h>
28 #include <utils/threads.h>
29 
30 #include <private/binder/binder_module.h>
31 #include <private/binder/Static.h>
32 
33 #include <errno.h>
34 #include <inttypes.h>
35 #include <pthread.h>
36 #include <sched.h>
37 #include <signal.h>
38 #include <stdio.h>
39 #include <sys/ioctl.h>
40 #include <sys/resource.h>
41 #include <unistd.h>
42 
43 #if LOG_NDEBUG
44 
45 #define IF_LOG_TRANSACTIONS() if (false)
46 #define IF_LOG_COMMANDS() if (false)
47 #define LOG_REMOTEREFS(...)
48 #define IF_LOG_REMOTEREFS() if (false)
49 
50 #define LOG_THREADPOOL(...)
51 #define LOG_ONEWAY(...)
52 
53 #else
54 
55 #define IF_LOG_TRANSACTIONS() IF_ALOG(LOG_VERBOSE, "transact")
56 #define IF_LOG_COMMANDS() IF_ALOG(LOG_VERBOSE, "ipc")
57 #define LOG_REMOTEREFS(...) ALOG(LOG_DEBUG, "remoterefs", __VA_ARGS__)
58 #define IF_LOG_REMOTEREFS() IF_ALOG(LOG_DEBUG, "remoterefs")
59 #define LOG_THREADPOOL(...) ALOG(LOG_DEBUG, "threadpool", __VA_ARGS__)
60 #define LOG_ONEWAY(...) ALOG(LOG_DEBUG, "ipc", __VA_ARGS__)
61 
62 #endif
63 
64 // ---------------------------------------------------------------------------
65 
66 namespace android {
67 
68 // Static const and functions will be optimized out if not used,
69 // when LOG_NDEBUG and references in IF_LOG_COMMANDS() are optimized out.
70 static const char *kReturnStrings[] = {
71     "BR_ERROR",
72     "BR_OK",
73     "BR_TRANSACTION",
74     "BR_REPLY",
75     "BR_ACQUIRE_RESULT",
76     "BR_DEAD_REPLY",
77     "BR_TRANSACTION_COMPLETE",
78     "BR_INCREFS",
79     "BR_ACQUIRE",
80     "BR_RELEASE",
81     "BR_DECREFS",
82     "BR_ATTEMPT_ACQUIRE",
83     "BR_NOOP",
84     "BR_SPAWN_LOOPER",
85     "BR_FINISHED",
86     "BR_DEAD_BINDER",
87     "BR_CLEAR_DEATH_NOTIFICATION_DONE",
88     "BR_FAILED_REPLY"
89 };
90 
91 static const char *kCommandStrings[] = {
92     "BC_TRANSACTION",
93     "BC_REPLY",
94     "BC_ACQUIRE_RESULT",
95     "BC_FREE_BUFFER",
96     "BC_INCREFS",
97     "BC_ACQUIRE",
98     "BC_RELEASE",
99     "BC_DECREFS",
100     "BC_INCREFS_DONE",
101     "BC_ACQUIRE_DONE",
102     "BC_ATTEMPT_ACQUIRE",
103     "BC_REGISTER_LOOPER",
104     "BC_ENTER_LOOPER",
105     "BC_EXIT_LOOPER",
106     "BC_REQUEST_DEATH_NOTIFICATION",
107     "BC_CLEAR_DEATH_NOTIFICATION",
108     "BC_DEAD_BINDER_DONE"
109 };
110 
getReturnString(uint32_t cmd)111 static const char* getReturnString(uint32_t cmd)
112 {
113     size_t idx = cmd & 0xff;
114     if (idx < sizeof(kReturnStrings) / sizeof(kReturnStrings[0]))
115         return kReturnStrings[idx];
116     else
117         return "unknown";
118 }
119 
printBinderTransactionData(TextOutput & out,const void * data)120 static const void* printBinderTransactionData(TextOutput& out, const void* data)
121 {
122     const binder_transaction_data* btd =
123         (const binder_transaction_data*)data;
124     if (btd->target.handle < 1024) {
125         /* want to print descriptors in decimal; guess based on value */
126         out << "target.desc=" << btd->target.handle;
127     } else {
128         out << "target.ptr=" << btd->target.ptr;
129     }
130     out << " (cookie " << btd->cookie << ")" << endl
131         << "code=" << TypeCode(btd->code) << ", flags=" << (void*)(long)btd->flags << endl
132         << "data=" << btd->data.ptr.buffer << " (" << (void*)btd->data_size
133         << " bytes)" << endl
134         << "offsets=" << btd->data.ptr.offsets << " (" << (void*)btd->offsets_size
135         << " bytes)";
136     return btd+1;
137 }
138 
printReturnCommand(TextOutput & out,const void * _cmd)139 static const void* printReturnCommand(TextOutput& out, const void* _cmd)
140 {
141     static const size_t N = sizeof(kReturnStrings)/sizeof(kReturnStrings[0]);
142     const int32_t* cmd = (const int32_t*)_cmd;
143     uint32_t code = (uint32_t)*cmd++;
144     size_t cmdIndex = code & 0xff;
145     if (code == BR_ERROR) {
146         out << "BR_ERROR: " << (void*)(long)(*cmd++) << endl;
147         return cmd;
148     } else if (cmdIndex >= N) {
149         out << "Unknown reply: " << code << endl;
150         return cmd;
151     }
152     out << kReturnStrings[cmdIndex];
153 
154     switch (code) {
155         case BR_TRANSACTION:
156         case BR_REPLY: {
157             out << ": " << indent;
158             cmd = (const int32_t *)printBinderTransactionData(out, cmd);
159             out << dedent;
160         } break;
161 
162         case BR_ACQUIRE_RESULT: {
163             const int32_t res = *cmd++;
164             out << ": " << res << (res ? " (SUCCESS)" : " (FAILURE)");
165         } break;
166 
167         case BR_INCREFS:
168         case BR_ACQUIRE:
169         case BR_RELEASE:
170         case BR_DECREFS: {
171             const int32_t b = *cmd++;
172             const int32_t c = *cmd++;
173             out << ": target=" << (void*)(long)b << " (cookie " << (void*)(long)c << ")";
174         } break;
175 
176         case BR_ATTEMPT_ACQUIRE: {
177             const int32_t p = *cmd++;
178             const int32_t b = *cmd++;
179             const int32_t c = *cmd++;
180             out << ": target=" << (void*)(long)b << " (cookie " << (void*)(long)c
181                 << "), pri=" << p;
182         } break;
183 
184         case BR_DEAD_BINDER:
185         case BR_CLEAR_DEATH_NOTIFICATION_DONE: {
186             const int32_t c = *cmd++;
187             out << ": death cookie " << (void*)(long)c;
188         } break;
189 
190         default:
191             // no details to show for: BR_OK, BR_DEAD_REPLY,
192             // BR_TRANSACTION_COMPLETE, BR_FINISHED
193             break;
194     }
195 
196     out << endl;
197     return cmd;
198 }
199 
printCommand(TextOutput & out,const void * _cmd)200 static const void* printCommand(TextOutput& out, const void* _cmd)
201 {
202     static const size_t N = sizeof(kCommandStrings)/sizeof(kCommandStrings[0]);
203     const int32_t* cmd = (const int32_t*)_cmd;
204     uint32_t code = (uint32_t)*cmd++;
205     size_t cmdIndex = code & 0xff;
206 
207     if (cmdIndex >= N) {
208         out << "Unknown command: " << code << endl;
209         return cmd;
210     }
211     out << kCommandStrings[cmdIndex];
212 
213     switch (code) {
214         case BC_TRANSACTION:
215         case BC_REPLY: {
216             out << ": " << indent;
217             cmd = (const int32_t *)printBinderTransactionData(out, cmd);
218             out << dedent;
219         } break;
220 
221         case BC_ACQUIRE_RESULT: {
222             const int32_t res = *cmd++;
223             out << ": " << res << (res ? " (SUCCESS)" : " (FAILURE)");
224         } break;
225 
226         case BC_FREE_BUFFER: {
227             const int32_t buf = *cmd++;
228             out << ": buffer=" << (void*)(long)buf;
229         } break;
230 
231         case BC_INCREFS:
232         case BC_ACQUIRE:
233         case BC_RELEASE:
234         case BC_DECREFS: {
235             const int32_t d = *cmd++;
236             out << ": desc=" << d;
237         } break;
238 
239         case BC_INCREFS_DONE:
240         case BC_ACQUIRE_DONE: {
241             const int32_t b = *cmd++;
242             const int32_t c = *cmd++;
243             out << ": target=" << (void*)(long)b << " (cookie " << (void*)(long)c << ")";
244         } break;
245 
246         case BC_ATTEMPT_ACQUIRE: {
247             const int32_t p = *cmd++;
248             const int32_t d = *cmd++;
249             out << ": desc=" << d << ", pri=" << p;
250         } break;
251 
252         case BC_REQUEST_DEATH_NOTIFICATION:
253         case BC_CLEAR_DEATH_NOTIFICATION: {
254             const int32_t h = *cmd++;
255             const int32_t c = *cmd++;
256             out << ": handle=" << h << " (death cookie " << (void*)(long)c << ")";
257         } break;
258 
259         case BC_DEAD_BINDER_DONE: {
260             const int32_t c = *cmd++;
261             out << ": death cookie " << (void*)(long)c;
262         } break;
263 
264         default:
265             // no details to show for: BC_REGISTER_LOOPER, BC_ENTER_LOOPER,
266             // BC_EXIT_LOOPER
267             break;
268     }
269 
270     out << endl;
271     return cmd;
272 }
273 
274 static pthread_mutex_t gTLSMutex = PTHREAD_MUTEX_INITIALIZER;
275 static bool gHaveTLS = false;
276 static pthread_key_t gTLS = 0;
277 static bool gShutdown = false;
278 static bool gDisableBackgroundScheduling = false;
279 
self()280 IPCThreadState* IPCThreadState::self()
281 {
282     if (gHaveTLS) {
283 restart:
284         const pthread_key_t k = gTLS;
285         IPCThreadState* st = (IPCThreadState*)pthread_getspecific(k);
286         if (st) return st;
287         return new IPCThreadState;
288     }
289 
290     if (gShutdown) {
291         ALOGW("Calling IPCThreadState::self() during shutdown is dangerous, expect a crash.\n");
292         return NULL;
293     }
294 
295     pthread_mutex_lock(&gTLSMutex);
296     if (!gHaveTLS) {
297         int key_create_value = pthread_key_create(&gTLS, threadDestructor);
298         if (key_create_value != 0) {
299             pthread_mutex_unlock(&gTLSMutex);
300             ALOGW("IPCThreadState::self() unable to create TLS key, expect a crash: %s\n",
301                     strerror(key_create_value));
302             return NULL;
303         }
304         gHaveTLS = true;
305     }
306     pthread_mutex_unlock(&gTLSMutex);
307     goto restart;
308 }
309 
selfOrNull()310 IPCThreadState* IPCThreadState::selfOrNull()
311 {
312     if (gHaveTLS) {
313         const pthread_key_t k = gTLS;
314         IPCThreadState* st = (IPCThreadState*)pthread_getspecific(k);
315         return st;
316     }
317     return NULL;
318 }
319 
shutdown()320 void IPCThreadState::shutdown()
321 {
322     gShutdown = true;
323 
324     if (gHaveTLS) {
325         // XXX Need to wait for all thread pool threads to exit!
326         IPCThreadState* st = (IPCThreadState*)pthread_getspecific(gTLS);
327         if (st) {
328             delete st;
329             pthread_setspecific(gTLS, NULL);
330         }
331         pthread_key_delete(gTLS);
332         gHaveTLS = false;
333     }
334 }
335 
disableBackgroundScheduling(bool disable)336 void IPCThreadState::disableBackgroundScheduling(bool disable)
337 {
338     gDisableBackgroundScheduling = disable;
339 }
340 
backgroundSchedulingDisabled()341 bool IPCThreadState::backgroundSchedulingDisabled()
342 {
343     return gDisableBackgroundScheduling;
344 }
345 
process()346 sp<ProcessState> IPCThreadState::process()
347 {
348     return mProcess;
349 }
350 
clearLastError()351 status_t IPCThreadState::clearLastError()
352 {
353     const status_t err = mLastError;
354     mLastError = NO_ERROR;
355     return err;
356 }
357 
getCallingPid() const358 pid_t IPCThreadState::getCallingPid() const
359 {
360     return mCallingPid;
361 }
362 
getCallingUid() const363 uid_t IPCThreadState::getCallingUid() const
364 {
365     return mCallingUid;
366 }
367 
clearCallingIdentity()368 int64_t IPCThreadState::clearCallingIdentity()
369 {
370     int64_t token = ((int64_t)mCallingUid<<32) | mCallingPid;
371     clearCaller();
372     return token;
373 }
374 
setStrictModePolicy(int32_t policy)375 void IPCThreadState::setStrictModePolicy(int32_t policy)
376 {
377     mStrictModePolicy = policy;
378 }
379 
getStrictModePolicy() const380 int32_t IPCThreadState::getStrictModePolicy() const
381 {
382     return mStrictModePolicy;
383 }
384 
setLastTransactionBinderFlags(int32_t flags)385 void IPCThreadState::setLastTransactionBinderFlags(int32_t flags)
386 {
387     mLastTransactionBinderFlags = flags;
388 }
389 
getLastTransactionBinderFlags() const390 int32_t IPCThreadState::getLastTransactionBinderFlags() const
391 {
392     return mLastTransactionBinderFlags;
393 }
394 
restoreCallingIdentity(int64_t token)395 void IPCThreadState::restoreCallingIdentity(int64_t token)
396 {
397     mCallingUid = (int)(token>>32);
398     mCallingPid = (int)token;
399 }
400 
clearCaller()401 void IPCThreadState::clearCaller()
402 {
403     mCallingPid = getpid();
404     mCallingUid = getuid();
405 }
406 
flushCommands()407 void IPCThreadState::flushCommands()
408 {
409     if (mProcess->mDriverFD <= 0)
410         return;
411     talkWithDriver(false);
412 }
413 
blockUntilThreadAvailable()414 void IPCThreadState::blockUntilThreadAvailable()
415 {
416     pthread_mutex_lock(&mProcess->mThreadCountLock);
417     while (mProcess->mExecutingThreadsCount >= mProcess->mMaxThreads) {
418         ALOGW("Waiting for thread to be free. mExecutingThreadsCount=%lu mMaxThreads=%lu\n",
419                 static_cast<unsigned long>(mProcess->mExecutingThreadsCount),
420                 static_cast<unsigned long>(mProcess->mMaxThreads));
421         pthread_cond_wait(&mProcess->mThreadCountDecrement, &mProcess->mThreadCountLock);
422     }
423     pthread_mutex_unlock(&mProcess->mThreadCountLock);
424 }
425 
getAndExecuteCommand()426 status_t IPCThreadState::getAndExecuteCommand()
427 {
428     status_t result;
429     int32_t cmd;
430 
431     result = talkWithDriver();
432     if (result >= NO_ERROR) {
433         size_t IN = mIn.dataAvail();
434         if (IN < sizeof(int32_t)) return result;
435         cmd = mIn.readInt32();
436         IF_LOG_COMMANDS() {
437             alog << "Processing top-level Command: "
438                  << getReturnString(cmd) << endl;
439         }
440 
441         pthread_mutex_lock(&mProcess->mThreadCountLock);
442         mProcess->mExecutingThreadsCount++;
443         if (mProcess->mExecutingThreadsCount >= mProcess->mMaxThreads &&
444                 mProcess->mStarvationStartTimeMs == 0) {
445             mProcess->mStarvationStartTimeMs = uptimeMillis();
446         }
447         pthread_mutex_unlock(&mProcess->mThreadCountLock);
448 
449         result = executeCommand(cmd);
450 
451         pthread_mutex_lock(&mProcess->mThreadCountLock);
452         mProcess->mExecutingThreadsCount--;
453         if (mProcess->mExecutingThreadsCount < mProcess->mMaxThreads &&
454                 mProcess->mStarvationStartTimeMs != 0) {
455             int64_t starvationTimeMs = uptimeMillis() - mProcess->mStarvationStartTimeMs;
456             if (starvationTimeMs > 100) {
457                 ALOGE("binder thread pool (%zu threads) starved for %" PRId64 " ms",
458                       mProcess->mMaxThreads, starvationTimeMs);
459             }
460             mProcess->mStarvationStartTimeMs = 0;
461         }
462         pthread_cond_broadcast(&mProcess->mThreadCountDecrement);
463         pthread_mutex_unlock(&mProcess->mThreadCountLock);
464     }
465 
466     return result;
467 }
468 
469 // When we've cleared the incoming command queue, process any pending derefs
processPendingDerefs()470 void IPCThreadState::processPendingDerefs()
471 {
472     if (mIn.dataPosition() >= mIn.dataSize()) {
473         size_t numPending = mPendingWeakDerefs.size();
474         if (numPending > 0) {
475             for (size_t i = 0; i < numPending; i++) {
476                 RefBase::weakref_type* refs = mPendingWeakDerefs[i];
477                 refs->decWeak(mProcess.get());
478             }
479             mPendingWeakDerefs.clear();
480         }
481 
482         numPending = mPendingStrongDerefs.size();
483         if (numPending > 0) {
484             for (size_t i = 0; i < numPending; i++) {
485                 BBinder* obj = mPendingStrongDerefs[i];
486                 obj->decStrong(mProcess.get());
487             }
488             mPendingStrongDerefs.clear();
489         }
490     }
491 }
492 
joinThreadPool(bool isMain)493 void IPCThreadState::joinThreadPool(bool isMain)
494 {
495     LOG_THREADPOOL("**** THREAD %p (PID %d) IS JOINING THE THREAD POOL\n", (void*)pthread_self(), getpid());
496 
497     mOut.writeInt32(isMain ? BC_ENTER_LOOPER : BC_REGISTER_LOOPER);
498 
499     status_t result;
500     do {
501         processPendingDerefs();
502         // now get the next command to be processed, waiting if necessary
503         result = getAndExecuteCommand();
504 
505         if (result < NO_ERROR && result != TIMED_OUT && result != -ECONNREFUSED && result != -EBADF) {
506             ALOGE("getAndExecuteCommand(fd=%d) returned unexpected error %d, aborting",
507                   mProcess->mDriverFD, result);
508             abort();
509         }
510 
511         // Let this thread exit the thread pool if it is no longer
512         // needed and it is not the main process thread.
513         if(result == TIMED_OUT && !isMain) {
514             break;
515         }
516     } while (result != -ECONNREFUSED && result != -EBADF);
517 
518     LOG_THREADPOOL("**** THREAD %p (PID %d) IS LEAVING THE THREAD POOL err=%d\n",
519         (void*)pthread_self(), getpid(), result);
520 
521     mOut.writeInt32(BC_EXIT_LOOPER);
522     talkWithDriver(false);
523 }
524 
setupPolling(int * fd)525 int IPCThreadState::setupPolling(int* fd)
526 {
527     if (mProcess->mDriverFD <= 0) {
528         return -EBADF;
529     }
530 
531     mOut.writeInt32(BC_ENTER_LOOPER);
532     *fd = mProcess->mDriverFD;
533     return 0;
534 }
535 
handlePolledCommands()536 status_t IPCThreadState::handlePolledCommands()
537 {
538     status_t result;
539 
540     do {
541         result = getAndExecuteCommand();
542     } while (mIn.dataPosition() < mIn.dataSize());
543 
544     processPendingDerefs();
545     flushCommands();
546     return result;
547 }
548 
stopProcess(bool)549 void IPCThreadState::stopProcess(bool /*immediate*/)
550 {
551     //ALOGI("**** STOPPING PROCESS");
552     flushCommands();
553     int fd = mProcess->mDriverFD;
554     mProcess->mDriverFD = -1;
555     close(fd);
556     //kill(getpid(), SIGKILL);
557 }
558 
transact(int32_t handle,uint32_t code,const Parcel & data,Parcel * reply,uint32_t flags)559 status_t IPCThreadState::transact(int32_t handle,
560                                   uint32_t code, const Parcel& data,
561                                   Parcel* reply, uint32_t flags)
562 {
563     status_t err = data.errorCheck();
564 
565     flags |= TF_ACCEPT_FDS;
566 
567     IF_LOG_TRANSACTIONS() {
568         TextOutput::Bundle _b(alog);
569         alog << "BC_TRANSACTION thr " << (void*)pthread_self() << " / hand "
570             << handle << " / code " << TypeCode(code) << ": "
571             << indent << data << dedent << endl;
572     }
573 
574     if (err == NO_ERROR) {
575         LOG_ONEWAY(">>>> SEND from pid %d uid %d %s", getpid(), getuid(),
576             (flags & TF_ONE_WAY) == 0 ? "READ REPLY" : "ONE WAY");
577         err = writeTransactionData(BC_TRANSACTION, flags, handle, code, data, NULL);
578     }
579 
580     if (err != NO_ERROR) {
581         if (reply) reply->setError(err);
582         return (mLastError = err);
583     }
584 
585     if ((flags & TF_ONE_WAY) == 0) {
586         #if 0
587         if (code == 4) { // relayout
588             ALOGI(">>>>>> CALLING transaction 4");
589         } else {
590             ALOGI(">>>>>> CALLING transaction %d", code);
591         }
592         #endif
593         if (reply) {
594             err = waitForResponse(reply);
595         } else {
596             Parcel fakeReply;
597             err = waitForResponse(&fakeReply);
598         }
599         #if 0
600         if (code == 4) { // relayout
601             ALOGI("<<<<<< RETURNING transaction 4");
602         } else {
603             ALOGI("<<<<<< RETURNING transaction %d", code);
604         }
605         #endif
606 
607         IF_LOG_TRANSACTIONS() {
608             TextOutput::Bundle _b(alog);
609             alog << "BR_REPLY thr " << (void*)pthread_self() << " / hand "
610                 << handle << ": ";
611             if (reply) alog << indent << *reply << dedent << endl;
612             else alog << "(none requested)" << endl;
613         }
614     } else {
615         err = waitForResponse(NULL, NULL);
616     }
617 
618     return err;
619 }
620 
incStrongHandle(int32_t handle)621 void IPCThreadState::incStrongHandle(int32_t handle)
622 {
623     LOG_REMOTEREFS("IPCThreadState::incStrongHandle(%d)\n", handle);
624     mOut.writeInt32(BC_ACQUIRE);
625     mOut.writeInt32(handle);
626 }
627 
decStrongHandle(int32_t handle)628 void IPCThreadState::decStrongHandle(int32_t handle)
629 {
630     LOG_REMOTEREFS("IPCThreadState::decStrongHandle(%d)\n", handle);
631     mOut.writeInt32(BC_RELEASE);
632     mOut.writeInt32(handle);
633 }
634 
incWeakHandle(int32_t handle)635 void IPCThreadState::incWeakHandle(int32_t handle)
636 {
637     LOG_REMOTEREFS("IPCThreadState::incWeakHandle(%d)\n", handle);
638     mOut.writeInt32(BC_INCREFS);
639     mOut.writeInt32(handle);
640 }
641 
decWeakHandle(int32_t handle)642 void IPCThreadState::decWeakHandle(int32_t handle)
643 {
644     LOG_REMOTEREFS("IPCThreadState::decWeakHandle(%d)\n", handle);
645     mOut.writeInt32(BC_DECREFS);
646     mOut.writeInt32(handle);
647 }
648 
attemptIncStrongHandle(int32_t handle)649 status_t IPCThreadState::attemptIncStrongHandle(int32_t handle)
650 {
651 #if HAS_BC_ATTEMPT_ACQUIRE
652     LOG_REMOTEREFS("IPCThreadState::attemptIncStrongHandle(%d)\n", handle);
653     mOut.writeInt32(BC_ATTEMPT_ACQUIRE);
654     mOut.writeInt32(0); // xxx was thread priority
655     mOut.writeInt32(handle);
656     status_t result = UNKNOWN_ERROR;
657 
658     waitForResponse(NULL, &result);
659 
660 #if LOG_REFCOUNTS
661     ALOGV("IPCThreadState::attemptIncStrongHandle(%ld) = %s\n",
662         handle, result == NO_ERROR ? "SUCCESS" : "FAILURE");
663 #endif
664 
665     return result;
666 #else
667     (void)handle;
668     ALOGE("%s(%d): Not supported\n", __func__, handle);
669     return INVALID_OPERATION;
670 #endif
671 }
672 
expungeHandle(int32_t handle,IBinder * binder)673 void IPCThreadState::expungeHandle(int32_t handle, IBinder* binder)
674 {
675 #if LOG_REFCOUNTS
676     ALOGV("IPCThreadState::expungeHandle(%ld)\n", handle);
677 #endif
678     self()->mProcess->expungeHandle(handle, binder);
679 }
680 
requestDeathNotification(int32_t handle,BpBinder * proxy)681 status_t IPCThreadState::requestDeathNotification(int32_t handle, BpBinder* proxy)
682 {
683     mOut.writeInt32(BC_REQUEST_DEATH_NOTIFICATION);
684     mOut.writeInt32((int32_t)handle);
685     mOut.writePointer((uintptr_t)proxy);
686     return NO_ERROR;
687 }
688 
clearDeathNotification(int32_t handle,BpBinder * proxy)689 status_t IPCThreadState::clearDeathNotification(int32_t handle, BpBinder* proxy)
690 {
691     mOut.writeInt32(BC_CLEAR_DEATH_NOTIFICATION);
692     mOut.writeInt32((int32_t)handle);
693     mOut.writePointer((uintptr_t)proxy);
694     return NO_ERROR;
695 }
696 
IPCThreadState()697 IPCThreadState::IPCThreadState()
698     : mProcess(ProcessState::self()),
699       mStrictModePolicy(0),
700       mLastTransactionBinderFlags(0)
701 {
702     pthread_setspecific(gTLS, this);
703     clearCaller();
704     mIn.setDataCapacity(256);
705     mOut.setDataCapacity(256);
706 }
707 
~IPCThreadState()708 IPCThreadState::~IPCThreadState()
709 {
710 }
711 
sendReply(const Parcel & reply,uint32_t flags)712 status_t IPCThreadState::sendReply(const Parcel& reply, uint32_t flags)
713 {
714     status_t err;
715     status_t statusBuffer;
716     err = writeTransactionData(BC_REPLY, flags, -1, 0, reply, &statusBuffer);
717     if (err < NO_ERROR) return err;
718 
719     return waitForResponse(NULL, NULL);
720 }
721 
waitForResponse(Parcel * reply,status_t * acquireResult)722 status_t IPCThreadState::waitForResponse(Parcel *reply, status_t *acquireResult)
723 {
724     uint32_t cmd;
725     int32_t err;
726 
727     while (1) {
728         if ((err=talkWithDriver()) < NO_ERROR) break;
729         err = mIn.errorCheck();
730         if (err < NO_ERROR) break;
731         if (mIn.dataAvail() == 0) continue;
732 
733         cmd = (uint32_t)mIn.readInt32();
734 
735         IF_LOG_COMMANDS() {
736             alog << "Processing waitForResponse Command: "
737                 << getReturnString(cmd) << endl;
738         }
739 
740         switch (cmd) {
741         case BR_TRANSACTION_COMPLETE:
742             if (!reply && !acquireResult) goto finish;
743             break;
744 
745         case BR_DEAD_REPLY:
746             err = DEAD_OBJECT;
747             goto finish;
748 
749         case BR_FAILED_REPLY:
750             err = FAILED_TRANSACTION;
751             goto finish;
752 
753         case BR_ACQUIRE_RESULT:
754             {
755                 ALOG_ASSERT(acquireResult != NULL, "Unexpected brACQUIRE_RESULT");
756                 const int32_t result = mIn.readInt32();
757                 if (!acquireResult) continue;
758                 *acquireResult = result ? NO_ERROR : INVALID_OPERATION;
759             }
760             goto finish;
761 
762         case BR_REPLY:
763             {
764                 binder_transaction_data tr;
765                 err = mIn.read(&tr, sizeof(tr));
766                 ALOG_ASSERT(err == NO_ERROR, "Not enough command data for brREPLY");
767                 if (err != NO_ERROR) goto finish;
768 
769                 if (reply) {
770                     if ((tr.flags & TF_STATUS_CODE) == 0) {
771                         reply->ipcSetDataReference(
772                             reinterpret_cast<const uint8_t*>(tr.data.ptr.buffer),
773                             tr.data_size,
774                             reinterpret_cast<const binder_size_t*>(tr.data.ptr.offsets),
775                             tr.offsets_size/sizeof(binder_size_t),
776                             freeBuffer, this);
777                     } else {
778                         err = *reinterpret_cast<const status_t*>(tr.data.ptr.buffer);
779                         freeBuffer(NULL,
780                             reinterpret_cast<const uint8_t*>(tr.data.ptr.buffer),
781                             tr.data_size,
782                             reinterpret_cast<const binder_size_t*>(tr.data.ptr.offsets),
783                             tr.offsets_size/sizeof(binder_size_t), this);
784                     }
785                 } else {
786                     freeBuffer(NULL,
787                         reinterpret_cast<const uint8_t*>(tr.data.ptr.buffer),
788                         tr.data_size,
789                         reinterpret_cast<const binder_size_t*>(tr.data.ptr.offsets),
790                         tr.offsets_size/sizeof(binder_size_t), this);
791                     continue;
792                 }
793             }
794             goto finish;
795 
796         default:
797             err = executeCommand(cmd);
798             if (err != NO_ERROR) goto finish;
799             break;
800         }
801     }
802 
803 finish:
804     if (err != NO_ERROR) {
805         if (acquireResult) *acquireResult = err;
806         if (reply) reply->setError(err);
807         mLastError = err;
808     }
809 
810     return err;
811 }
812 
talkWithDriver(bool doReceive)813 status_t IPCThreadState::talkWithDriver(bool doReceive)
814 {
815     if (mProcess->mDriverFD <= 0) {
816         return -EBADF;
817     }
818 
819     binder_write_read bwr;
820 
821     // Is the read buffer empty?
822     const bool needRead = mIn.dataPosition() >= mIn.dataSize();
823 
824     // We don't want to write anything if we are still reading
825     // from data left in the input buffer and the caller
826     // has requested to read the next data.
827     const size_t outAvail = (!doReceive || needRead) ? mOut.dataSize() : 0;
828 
829     bwr.write_size = outAvail;
830     bwr.write_buffer = (uintptr_t)mOut.data();
831 
832     // This is what we'll read.
833     if (doReceive && needRead) {
834         bwr.read_size = mIn.dataCapacity();
835         bwr.read_buffer = (uintptr_t)mIn.data();
836     } else {
837         bwr.read_size = 0;
838         bwr.read_buffer = 0;
839     }
840 
841     IF_LOG_COMMANDS() {
842         TextOutput::Bundle _b(alog);
843         if (outAvail != 0) {
844             alog << "Sending commands to driver: " << indent;
845             const void* cmds = (const void*)bwr.write_buffer;
846             const void* end = ((const uint8_t*)cmds)+bwr.write_size;
847             alog << HexDump(cmds, bwr.write_size) << endl;
848             while (cmds < end) cmds = printCommand(alog, cmds);
849             alog << dedent;
850         }
851         alog << "Size of receive buffer: " << bwr.read_size
852             << ", needRead: " << needRead << ", doReceive: " << doReceive << endl;
853     }
854 
855     // Return immediately if there is nothing to do.
856     if ((bwr.write_size == 0) && (bwr.read_size == 0)) return NO_ERROR;
857 
858     bwr.write_consumed = 0;
859     bwr.read_consumed = 0;
860     status_t err;
861     do {
862         IF_LOG_COMMANDS() {
863             alog << "About to read/write, write size = " << mOut.dataSize() << endl;
864         }
865 #if defined(__ANDROID__)
866         if (ioctl(mProcess->mDriverFD, BINDER_WRITE_READ, &bwr) >= 0)
867             err = NO_ERROR;
868         else
869             err = -errno;
870 #else
871         err = INVALID_OPERATION;
872 #endif
873         if (mProcess->mDriverFD <= 0) {
874             err = -EBADF;
875         }
876         IF_LOG_COMMANDS() {
877             alog << "Finished read/write, write size = " << mOut.dataSize() << endl;
878         }
879     } while (err == -EINTR);
880 
881     IF_LOG_COMMANDS() {
882         alog << "Our err: " << (void*)(intptr_t)err << ", write consumed: "
883             << bwr.write_consumed << " (of " << mOut.dataSize()
884                         << "), read consumed: " << bwr.read_consumed << endl;
885     }
886 
887     if (err >= NO_ERROR) {
888         if (bwr.write_consumed > 0) {
889             if (bwr.write_consumed < mOut.dataSize())
890                 mOut.remove(0, bwr.write_consumed);
891             else
892                 mOut.setDataSize(0);
893         }
894         if (bwr.read_consumed > 0) {
895             mIn.setDataSize(bwr.read_consumed);
896             mIn.setDataPosition(0);
897         }
898         IF_LOG_COMMANDS() {
899             TextOutput::Bundle _b(alog);
900             alog << "Remaining data size: " << mOut.dataSize() << endl;
901             alog << "Received commands from driver: " << indent;
902             const void* cmds = mIn.data();
903             const void* end = mIn.data() + mIn.dataSize();
904             alog << HexDump(cmds, mIn.dataSize()) << endl;
905             while (cmds < end) cmds = printReturnCommand(alog, cmds);
906             alog << dedent;
907         }
908         return NO_ERROR;
909     }
910 
911     return err;
912 }
913 
writeTransactionData(int32_t cmd,uint32_t binderFlags,int32_t handle,uint32_t code,const Parcel & data,status_t * statusBuffer)914 status_t IPCThreadState::writeTransactionData(int32_t cmd, uint32_t binderFlags,
915     int32_t handle, uint32_t code, const Parcel& data, status_t* statusBuffer)
916 {
917     binder_transaction_data tr;
918 
919     tr.target.ptr = 0; /* Don't pass uninitialized stack data to a remote process */
920     tr.target.handle = handle;
921     tr.code = code;
922     tr.flags = binderFlags;
923     tr.cookie = 0;
924     tr.sender_pid = 0;
925     tr.sender_euid = 0;
926 
927     const status_t err = data.errorCheck();
928     if (err == NO_ERROR) {
929         tr.data_size = data.ipcDataSize();
930         tr.data.ptr.buffer = data.ipcData();
931         tr.offsets_size = data.ipcObjectsCount()*sizeof(binder_size_t);
932         tr.data.ptr.offsets = data.ipcObjects();
933     } else if (statusBuffer) {
934         tr.flags |= TF_STATUS_CODE;
935         *statusBuffer = err;
936         tr.data_size = sizeof(status_t);
937         tr.data.ptr.buffer = reinterpret_cast<uintptr_t>(statusBuffer);
938         tr.offsets_size = 0;
939         tr.data.ptr.offsets = 0;
940     } else {
941         return (mLastError = err);
942     }
943 
944     mOut.writeInt32(cmd);
945     mOut.write(&tr, sizeof(tr));
946 
947     return NO_ERROR;
948 }
949 
950 sp<BBinder> the_context_object;
951 
setTheContextObject(sp<BBinder> obj)952 void setTheContextObject(sp<BBinder> obj)
953 {
954     the_context_object = obj;
955 }
956 
executeCommand(int32_t cmd)957 status_t IPCThreadState::executeCommand(int32_t cmd)
958 {
959     BBinder* obj;
960     RefBase::weakref_type* refs;
961     status_t result = NO_ERROR;
962 
963     switch ((uint32_t)cmd) {
964     case BR_ERROR:
965         result = mIn.readInt32();
966         break;
967 
968     case BR_OK:
969         break;
970 
971     case BR_ACQUIRE:
972         refs = (RefBase::weakref_type*)mIn.readPointer();
973         obj = (BBinder*)mIn.readPointer();
974         ALOG_ASSERT(refs->refBase() == obj,
975                    "BR_ACQUIRE: object %p does not match cookie %p (expected %p)",
976                    refs, obj, refs->refBase());
977         obj->incStrong(mProcess.get());
978         IF_LOG_REMOTEREFS() {
979             LOG_REMOTEREFS("BR_ACQUIRE from driver on %p", obj);
980             obj->printRefs();
981         }
982         mOut.writeInt32(BC_ACQUIRE_DONE);
983         mOut.writePointer((uintptr_t)refs);
984         mOut.writePointer((uintptr_t)obj);
985         break;
986 
987     case BR_RELEASE:
988         refs = (RefBase::weakref_type*)mIn.readPointer();
989         obj = (BBinder*)mIn.readPointer();
990         ALOG_ASSERT(refs->refBase() == obj,
991                    "BR_RELEASE: object %p does not match cookie %p (expected %p)",
992                    refs, obj, refs->refBase());
993         IF_LOG_REMOTEREFS() {
994             LOG_REMOTEREFS("BR_RELEASE from driver on %p", obj);
995             obj->printRefs();
996         }
997         mPendingStrongDerefs.push(obj);
998         break;
999 
1000     case BR_INCREFS:
1001         refs = (RefBase::weakref_type*)mIn.readPointer();
1002         obj = (BBinder*)mIn.readPointer();
1003         refs->incWeak(mProcess.get());
1004         mOut.writeInt32(BC_INCREFS_DONE);
1005         mOut.writePointer((uintptr_t)refs);
1006         mOut.writePointer((uintptr_t)obj);
1007         break;
1008 
1009     case BR_DECREFS:
1010         refs = (RefBase::weakref_type*)mIn.readPointer();
1011         obj = (BBinder*)mIn.readPointer();
1012         // NOTE: This assertion is not valid, because the object may no
1013         // longer exist (thus the (BBinder*)cast above resulting in a different
1014         // memory address).
1015         //ALOG_ASSERT(refs->refBase() == obj,
1016         //           "BR_DECREFS: object %p does not match cookie %p (expected %p)",
1017         //           refs, obj, refs->refBase());
1018         mPendingWeakDerefs.push(refs);
1019         break;
1020 
1021     case BR_ATTEMPT_ACQUIRE:
1022         refs = (RefBase::weakref_type*)mIn.readPointer();
1023         obj = (BBinder*)mIn.readPointer();
1024 
1025         {
1026             const bool success = refs->attemptIncStrong(mProcess.get());
1027             ALOG_ASSERT(success && refs->refBase() == obj,
1028                        "BR_ATTEMPT_ACQUIRE: object %p does not match cookie %p (expected %p)",
1029                        refs, obj, refs->refBase());
1030 
1031             mOut.writeInt32(BC_ACQUIRE_RESULT);
1032             mOut.writeInt32((int32_t)success);
1033         }
1034         break;
1035 
1036     case BR_TRANSACTION:
1037         {
1038             binder_transaction_data tr;
1039             result = mIn.read(&tr, sizeof(tr));
1040             ALOG_ASSERT(result == NO_ERROR,
1041                 "Not enough command data for brTRANSACTION");
1042             if (result != NO_ERROR) break;
1043 
1044             Parcel buffer;
1045             buffer.ipcSetDataReference(
1046                 reinterpret_cast<const uint8_t*>(tr.data.ptr.buffer),
1047                 tr.data_size,
1048                 reinterpret_cast<const binder_size_t*>(tr.data.ptr.offsets),
1049                 tr.offsets_size/sizeof(binder_size_t), freeBuffer, this);
1050 
1051             const pid_t origPid = mCallingPid;
1052             const uid_t origUid = mCallingUid;
1053             const int32_t origStrictModePolicy = mStrictModePolicy;
1054             const int32_t origTransactionBinderFlags = mLastTransactionBinderFlags;
1055 
1056             mCallingPid = tr.sender_pid;
1057             mCallingUid = tr.sender_euid;
1058             mLastTransactionBinderFlags = tr.flags;
1059 
1060             //ALOGI(">>>> TRANSACT from pid %d uid %d\n", mCallingPid, mCallingUid);
1061 
1062             Parcel reply;
1063             status_t error;
1064             IF_LOG_TRANSACTIONS() {
1065                 TextOutput::Bundle _b(alog);
1066                 alog << "BR_TRANSACTION thr " << (void*)pthread_self()
1067                     << " / obj " << tr.target.ptr << " / code "
1068                     << TypeCode(tr.code) << ": " << indent << buffer
1069                     << dedent << endl
1070                     << "Data addr = "
1071                     << reinterpret_cast<const uint8_t*>(tr.data.ptr.buffer)
1072                     << ", offsets addr="
1073                     << reinterpret_cast<const size_t*>(tr.data.ptr.offsets) << endl;
1074             }
1075             if (tr.target.ptr) {
1076                 // We only have a weak reference on the target object, so we must first try to
1077                 // safely acquire a strong reference before doing anything else with it.
1078                 if (reinterpret_cast<RefBase::weakref_type*>(
1079                         tr.target.ptr)->attemptIncStrong(this)) {
1080                     error = reinterpret_cast<BBinder*>(tr.cookie)->transact(tr.code, buffer,
1081                             &reply, tr.flags);
1082                     reinterpret_cast<BBinder*>(tr.cookie)->decStrong(this);
1083                 } else {
1084                     error = UNKNOWN_TRANSACTION;
1085                 }
1086 
1087             } else {
1088                 error = the_context_object->transact(tr.code, buffer, &reply, tr.flags);
1089             }
1090 
1091             //ALOGI("<<<< TRANSACT from pid %d restore pid %d uid %d\n",
1092             //     mCallingPid, origPid, origUid);
1093 
1094             if ((tr.flags & TF_ONE_WAY) == 0) {
1095                 LOG_ONEWAY("Sending reply to %d!", mCallingPid);
1096                 if (error < NO_ERROR) reply.setError(error);
1097                 sendReply(reply, 0);
1098             } else {
1099                 LOG_ONEWAY("NOT sending reply to %d!", mCallingPid);
1100             }
1101 
1102             mCallingPid = origPid;
1103             mCallingUid = origUid;
1104             mStrictModePolicy = origStrictModePolicy;
1105             mLastTransactionBinderFlags = origTransactionBinderFlags;
1106 
1107             IF_LOG_TRANSACTIONS() {
1108                 TextOutput::Bundle _b(alog);
1109                 alog << "BC_REPLY thr " << (void*)pthread_self() << " / obj "
1110                     << tr.target.ptr << ": " << indent << reply << dedent << endl;
1111             }
1112 
1113         }
1114         break;
1115 
1116     case BR_DEAD_BINDER:
1117         {
1118             BpBinder *proxy = (BpBinder*)mIn.readPointer();
1119             proxy->sendObituary();
1120             mOut.writeInt32(BC_DEAD_BINDER_DONE);
1121             mOut.writePointer((uintptr_t)proxy);
1122         } break;
1123 
1124     case BR_CLEAR_DEATH_NOTIFICATION_DONE:
1125         {
1126             BpBinder *proxy = (BpBinder*)mIn.readPointer();
1127             proxy->getWeakRefs()->decWeak(proxy);
1128         } break;
1129 
1130     case BR_FINISHED:
1131         result = TIMED_OUT;
1132         break;
1133 
1134     case BR_NOOP:
1135         break;
1136 
1137     case BR_SPAWN_LOOPER:
1138         mProcess->spawnPooledThread(false);
1139         break;
1140 
1141     default:
1142         ALOGE("*** BAD COMMAND %d received from Binder driver\n", cmd);
1143         result = UNKNOWN_ERROR;
1144         break;
1145     }
1146 
1147     if (result != NO_ERROR) {
1148         mLastError = result;
1149     }
1150 
1151     return result;
1152 }
1153 
threadDestructor(void * st)1154 void IPCThreadState::threadDestructor(void *st)
1155 {
1156         IPCThreadState* const self = static_cast<IPCThreadState*>(st);
1157         if (self) {
1158                 self->flushCommands();
1159 #if defined(__ANDROID__)
1160         if (self->mProcess->mDriverFD > 0) {
1161             ioctl(self->mProcess->mDriverFD, BINDER_THREAD_EXIT, 0);
1162         }
1163 #endif
1164                 delete self;
1165         }
1166 }
1167 
1168 
freeBuffer(Parcel * parcel,const uint8_t * data,size_t,const binder_size_t *,size_t,void *)1169 void IPCThreadState::freeBuffer(Parcel* parcel, const uint8_t* data,
1170                                 size_t /*dataSize*/,
1171                                 const binder_size_t* /*objects*/,
1172                                 size_t /*objectsSize*/, void* /*cookie*/)
1173 {
1174     //ALOGI("Freeing parcel %p", &parcel);
1175     IF_LOG_COMMANDS() {
1176         alog << "Writing BC_FREE_BUFFER for " << data << endl;
1177     }
1178     ALOG_ASSERT(data != NULL, "Called with NULL data");
1179     if (parcel != NULL) parcel->closeFileDescriptors();
1180     IPCThreadState* state = self();
1181     state->mOut.writeInt32(BC_FREE_BUFFER);
1182     state->mOut.writePointer((uintptr_t)data);
1183 }
1184 
1185 }; // namespace android
1186