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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 <cutils/sched_policy.h>
24 #include <utils/Debug.h>
25 #include <utils/Log.h>
26 #include <utils/TextOutput.h>
27 #include <utils/threads.h>
28 
29 #include <private/binder/binder_module.h>
30 #include <private/binder/Static.h>
31 
32 #include <sys/ioctl.h>
33 #include <signal.h>
34 #include <errno.h>
35 #include <stdio.h>
36 #include <unistd.h>
37 
38 #ifdef HAVE_PTHREADS
39 #include <pthread.h>
40 #include <sched.h>
41 #include <sys/resource.h>
42 #endif
43 #ifdef HAVE_WIN32_THREADS
44 #include <windows.h>
45 #endif
46 
47 
48 #if LOG_NDEBUG
49 
50 #define IF_LOG_TRANSACTIONS() if (false)
51 #define IF_LOG_COMMANDS() if (false)
52 #define LOG_REMOTEREFS(...)
53 #define IF_LOG_REMOTEREFS() if (false)
54 #define LOG_THREADPOOL(...)
55 #define LOG_ONEWAY(...)
56 
57 #else
58 
59 #define IF_LOG_TRANSACTIONS() IF_ALOG(LOG_VERBOSE, "transact")
60 #define IF_LOG_COMMANDS() IF_ALOG(LOG_VERBOSE, "ipc")
61 #define LOG_REMOTEREFS(...) ALOG(LOG_DEBUG, "remoterefs", __VA_ARGS__)
62 #define IF_LOG_REMOTEREFS() IF_ALOG(LOG_DEBUG, "remoterefs")
63 #define LOG_THREADPOOL(...) ALOG(LOG_DEBUG, "threadpool", __VA_ARGS__)
64 #define LOG_ONEWAY(...) ALOG(LOG_DEBUG, "ipc", __VA_ARGS__)
65 
66 #endif
67 
68 // ---------------------------------------------------------------------------
69 
70 namespace android {
71 
72 static const char* getReturnString(size_t idx);
73 static const char* getCommandString(size_t idx);
74 static const void* printReturnCommand(TextOutput& out, const void* _cmd);
75 static const void* printCommand(TextOutput& out, const void* _cmd);
76 
77 // This will result in a missing symbol failure if the IF_LOG_COMMANDS()
78 // conditionals don't get stripped...  but that is probably what we want.
79 #if !LOG_NDEBUG
80 static const char *kReturnStrings[] = {
81     "BR_ERROR",
82     "BR_OK",
83     "BR_TRANSACTION",
84     "BR_REPLY",
85     "BR_ACQUIRE_RESULT",
86     "BR_DEAD_REPLY",
87     "BR_TRANSACTION_COMPLETE",
88     "BR_INCREFS",
89     "BR_ACQUIRE",
90     "BR_RELEASE",
91     "BR_DECREFS",
92     "BR_ATTEMPT_ACQUIRE",
93     "BR_NOOP",
94     "BR_SPAWN_LOOPER",
95     "BR_FINISHED",
96     "BR_DEAD_BINDER",
97     "BR_CLEAR_DEATH_NOTIFICATION_DONE",
98     "BR_FAILED_REPLY"
99 };
100 
101 static const char *kCommandStrings[] = {
102     "BC_TRANSACTION",
103     "BC_REPLY",
104     "BC_ACQUIRE_RESULT",
105     "BC_FREE_BUFFER",
106     "BC_INCREFS",
107     "BC_ACQUIRE",
108     "BC_RELEASE",
109     "BC_DECREFS",
110     "BC_INCREFS_DONE",
111     "BC_ACQUIRE_DONE",
112     "BC_ATTEMPT_ACQUIRE",
113     "BC_REGISTER_LOOPER",
114     "BC_ENTER_LOOPER",
115     "BC_EXIT_LOOPER",
116     "BC_REQUEST_DEATH_NOTIFICATION",
117     "BC_CLEAR_DEATH_NOTIFICATION",
118     "BC_DEAD_BINDER_DONE"
119 };
120 
getReturnString(size_t idx)121 static const char* getReturnString(size_t idx)
122 {
123     if (idx < sizeof(kReturnStrings) / sizeof(kReturnStrings[0]))
124         return kReturnStrings[idx];
125     else
126         return "unknown";
127 }
128 
getCommandString(size_t idx)129 static const char* getCommandString(size_t idx)
130 {
131     if (idx < sizeof(kCommandStrings) / sizeof(kCommandStrings[0]))
132         return kCommandStrings[idx];
133     else
134         return "unknown";
135 }
136 
printBinderTransactionData(TextOutput & out,const void * data)137 static const void* printBinderTransactionData(TextOutput& out, const void* data)
138 {
139     const binder_transaction_data* btd =
140         (const binder_transaction_data*)data;
141     if (btd->target.handle < 1024) {
142         /* want to print descriptors in decimal; guess based on value */
143         out << "target.desc=" << btd->target.handle;
144     } else {
145         out << "target.ptr=" << btd->target.ptr;
146     }
147     out << " (cookie " << btd->cookie << ")" << endl
148         << "code=" << TypeCode(btd->code) << ", flags=" << (void*)btd->flags << endl
149         << "data=" << btd->data.ptr.buffer << " (" << (void*)btd->data_size
150         << " bytes)" << endl
151         << "offsets=" << btd->data.ptr.offsets << " (" << (void*)btd->offsets_size
152         << " bytes)";
153     return btd+1;
154 }
155 
printReturnCommand(TextOutput & out,const void * _cmd)156 static const void* printReturnCommand(TextOutput& out, const void* _cmd)
157 {
158     static const size_t N = sizeof(kReturnStrings)/sizeof(kReturnStrings[0]);
159     const int32_t* cmd = (const int32_t*)_cmd;
160     int32_t code = *cmd++;
161     size_t cmdIndex = code & 0xff;
162     if (code == (int32_t) BR_ERROR) {
163         out << "BR_ERROR: " << (void*)(*cmd++) << endl;
164         return cmd;
165     } else if (cmdIndex >= N) {
166         out << "Unknown reply: " << code << endl;
167         return cmd;
168     }
169     out << kReturnStrings[cmdIndex];
170 
171     switch (code) {
172         case BR_TRANSACTION:
173         case BR_REPLY: {
174             out << ": " << indent;
175             cmd = (const int32_t *)printBinderTransactionData(out, cmd);
176             out << dedent;
177         } break;
178 
179         case BR_ACQUIRE_RESULT: {
180             const int32_t res = *cmd++;
181             out << ": " << res << (res ? " (SUCCESS)" : " (FAILURE)");
182         } break;
183 
184         case BR_INCREFS:
185         case BR_ACQUIRE:
186         case BR_RELEASE:
187         case BR_DECREFS: {
188             const int32_t b = *cmd++;
189             const int32_t c = *cmd++;
190             out << ": target=" << (void*)b << " (cookie " << (void*)c << ")";
191         } break;
192 
193         case BR_ATTEMPT_ACQUIRE: {
194             const int32_t p = *cmd++;
195             const int32_t b = *cmd++;
196             const int32_t c = *cmd++;
197             out << ": target=" << (void*)b << " (cookie " << (void*)c
198                 << "), pri=" << p;
199         } break;
200 
201         case BR_DEAD_BINDER:
202         case BR_CLEAR_DEATH_NOTIFICATION_DONE: {
203             const int32_t c = *cmd++;
204             out << ": death cookie " << (void*)c;
205         } break;
206 
207         default:
208             // no details to show for: BR_OK, BR_DEAD_REPLY,
209             // BR_TRANSACTION_COMPLETE, BR_FINISHED
210             break;
211     }
212 
213     out << endl;
214     return cmd;
215 }
216 
printCommand(TextOutput & out,const void * _cmd)217 static const void* printCommand(TextOutput& out, const void* _cmd)
218 {
219     static const size_t N = sizeof(kCommandStrings)/sizeof(kCommandStrings[0]);
220     const int32_t* cmd = (const int32_t*)_cmd;
221     int32_t code = *cmd++;
222     size_t cmdIndex = code & 0xff;
223 
224     if (cmdIndex >= N) {
225         out << "Unknown command: " << code << endl;
226         return cmd;
227     }
228     out << kCommandStrings[cmdIndex];
229 
230     switch (code) {
231         case BC_TRANSACTION:
232         case BC_REPLY: {
233             out << ": " << indent;
234             cmd = (const int32_t *)printBinderTransactionData(out, cmd);
235             out << dedent;
236         } break;
237 
238         case BC_ACQUIRE_RESULT: {
239             const int32_t res = *cmd++;
240             out << ": " << res << (res ? " (SUCCESS)" : " (FAILURE)");
241         } break;
242 
243         case BC_FREE_BUFFER: {
244             const int32_t buf = *cmd++;
245             out << ": buffer=" << (void*)buf;
246         } break;
247 
248         case BC_INCREFS:
249         case BC_ACQUIRE:
250         case BC_RELEASE:
251         case BC_DECREFS: {
252             const int32_t d = *cmd++;
253             out << ": desc=" << d;
254         } break;
255 
256         case BC_INCREFS_DONE:
257         case BC_ACQUIRE_DONE: {
258             const int32_t b = *cmd++;
259             const int32_t c = *cmd++;
260             out << ": target=" << (void*)b << " (cookie " << (void*)c << ")";
261         } break;
262 
263         case BC_ATTEMPT_ACQUIRE: {
264             const int32_t p = *cmd++;
265             const int32_t d = *cmd++;
266             out << ": desc=" << d << ", pri=" << p;
267         } break;
268 
269         case BC_REQUEST_DEATH_NOTIFICATION:
270         case BC_CLEAR_DEATH_NOTIFICATION: {
271             const int32_t h = *cmd++;
272             const int32_t c = *cmd++;
273             out << ": handle=" << h << " (death cookie " << (void*)c << ")";
274         } break;
275 
276         case BC_DEAD_BINDER_DONE: {
277             const int32_t c = *cmd++;
278             out << ": death cookie " << (void*)c;
279         } break;
280 
281         default:
282             // no details to show for: BC_REGISTER_LOOPER, BC_ENTER_LOOPER,
283             // BC_EXIT_LOOPER
284             break;
285     }
286 
287     out << endl;
288     return cmd;
289 }
290 #endif
291 
292 static pthread_mutex_t gTLSMutex = PTHREAD_MUTEX_INITIALIZER;
293 static bool gHaveTLS = false;
294 static pthread_key_t gTLS = 0;
295 static bool gShutdown = false;
296 static bool gDisableBackgroundScheduling = false;
297 
self()298 IPCThreadState* IPCThreadState::self()
299 {
300     if (gHaveTLS) {
301 restart:
302         const pthread_key_t k = gTLS;
303         IPCThreadState* st = (IPCThreadState*)pthread_getspecific(k);
304         if (st) return st;
305         return new IPCThreadState;
306     }
307 
308     if (gShutdown) return NULL;
309 
310     pthread_mutex_lock(&gTLSMutex);
311     if (!gHaveTLS) {
312         if (pthread_key_create(&gTLS, threadDestructor) != 0) {
313             pthread_mutex_unlock(&gTLSMutex);
314             return NULL;
315         }
316         gHaveTLS = true;
317     }
318     pthread_mutex_unlock(&gTLSMutex);
319     goto restart;
320 }
321 
selfOrNull()322 IPCThreadState* IPCThreadState::selfOrNull()
323 {
324     if (gHaveTLS) {
325         const pthread_key_t k = gTLS;
326         IPCThreadState* st = (IPCThreadState*)pthread_getspecific(k);
327         return st;
328     }
329     return NULL;
330 }
331 
shutdown()332 void IPCThreadState::shutdown()
333 {
334     gShutdown = true;
335 
336     if (gHaveTLS) {
337         // XXX Need to wait for all thread pool threads to exit!
338         IPCThreadState* st = (IPCThreadState*)pthread_getspecific(gTLS);
339         if (st) {
340             delete st;
341             pthread_setspecific(gTLS, NULL);
342         }
343         gHaveTLS = false;
344     }
345 }
346 
disableBackgroundScheduling(bool disable)347 void IPCThreadState::disableBackgroundScheduling(bool disable)
348 {
349     gDisableBackgroundScheduling = disable;
350 }
351 
process()352 sp<ProcessState> IPCThreadState::process()
353 {
354     return mProcess;
355 }
356 
clearLastError()357 status_t IPCThreadState::clearLastError()
358 {
359     const status_t err = mLastError;
360     mLastError = NO_ERROR;
361     return err;
362 }
363 
getCallingPid()364 int IPCThreadState::getCallingPid()
365 {
366     return mCallingPid;
367 }
368 
getCallingUid()369 int IPCThreadState::getCallingUid()
370 {
371     return mCallingUid;
372 }
373 
clearCallingIdentity()374 int64_t IPCThreadState::clearCallingIdentity()
375 {
376     int64_t token = ((int64_t)mCallingUid<<32) | mCallingPid;
377     clearCaller();
378     return token;
379 }
380 
setStrictModePolicy(int32_t policy)381 void IPCThreadState::setStrictModePolicy(int32_t policy)
382 {
383     mStrictModePolicy = policy;
384 }
385 
getStrictModePolicy() const386 int32_t IPCThreadState::getStrictModePolicy() const
387 {
388     return mStrictModePolicy;
389 }
390 
setLastTransactionBinderFlags(int32_t flags)391 void IPCThreadState::setLastTransactionBinderFlags(int32_t flags)
392 {
393     mLastTransactionBinderFlags = flags;
394 }
395 
getLastTransactionBinderFlags() const396 int32_t IPCThreadState::getLastTransactionBinderFlags() const
397 {
398     return mLastTransactionBinderFlags;
399 }
400 
restoreCallingIdentity(int64_t token)401 void IPCThreadState::restoreCallingIdentity(int64_t token)
402 {
403     mCallingUid = (int)(token>>32);
404     mCallingPid = (int)token;
405 }
406 
clearCaller()407 void IPCThreadState::clearCaller()
408 {
409     mCallingPid = getpid();
410     mCallingUid = getuid();
411 }
412 
flushCommands()413 void IPCThreadState::flushCommands()
414 {
415     if (mProcess->mDriverFD <= 0)
416         return;
417     talkWithDriver(false);
418 }
419 
joinThreadPool(bool isMain)420 void IPCThreadState::joinThreadPool(bool isMain)
421 {
422     LOG_THREADPOOL("**** THREAD %p (PID %d) IS JOINING THE THREAD POOL\n", (void*)pthread_self(), getpid());
423 
424     mOut.writeInt32(isMain ? BC_ENTER_LOOPER : BC_REGISTER_LOOPER);
425 
426     // This thread may have been spawned by a thread that was in the background
427     // scheduling group, so first we will make sure it is in the foreground
428     // one to avoid performing an initial transaction in the background.
429     set_sched_policy(mMyThreadId, SP_FOREGROUND);
430 
431     status_t result;
432     do {
433         int32_t cmd;
434 
435         // When we've cleared the incoming command queue, process any pending derefs
436         if (mIn.dataPosition() >= mIn.dataSize()) {
437             size_t numPending = mPendingWeakDerefs.size();
438             if (numPending > 0) {
439                 for (size_t i = 0; i < numPending; i++) {
440                     RefBase::weakref_type* refs = mPendingWeakDerefs[i];
441                     refs->decWeak(mProcess.get());
442                 }
443                 mPendingWeakDerefs.clear();
444             }
445 
446             numPending = mPendingStrongDerefs.size();
447             if (numPending > 0) {
448                 for (size_t i = 0; i < numPending; i++) {
449                     BBinder* obj = mPendingStrongDerefs[i];
450                     obj->decStrong(mProcess.get());
451                 }
452                 mPendingStrongDerefs.clear();
453             }
454         }
455 
456         // now get the next command to be processed, waiting if necessary
457         result = talkWithDriver();
458         if (result >= NO_ERROR) {
459             size_t IN = mIn.dataAvail();
460             if (IN < sizeof(int32_t)) continue;
461             cmd = mIn.readInt32();
462             IF_LOG_COMMANDS() {
463                 alog << "Processing top-level Command: "
464                     << getReturnString(cmd) << endl;
465             }
466 
467 
468             result = executeCommand(cmd);
469         } else if (result != TIMED_OUT && result != -ECONNREFUSED && result != -EBADF) {
470             ALOGE("talkWithDriver(fd=%d) returned unexpected error %d, aborting",
471                   mProcess->mDriverFD, result);
472             abort();
473         }
474 
475         // After executing the command, ensure that the thread is returned to the
476         // foreground cgroup before rejoining the pool.  The driver takes care of
477         // restoring the priority, but doesn't do anything with cgroups so we
478         // need to take care of that here in userspace.  Note that we do make
479         // sure to go in the foreground after executing a transaction, but
480         // there are other callbacks into user code that could have changed
481         // our group so we want to make absolutely sure it is put back.
482         set_sched_policy(mMyThreadId, SP_FOREGROUND);
483 
484         // Let this thread exit the thread pool if it is no longer
485         // needed and it is not the main process thread.
486         if(result == TIMED_OUT && !isMain) {
487             break;
488         }
489     } while (result != -ECONNREFUSED && result != -EBADF);
490 
491     LOG_THREADPOOL("**** THREAD %p (PID %d) IS LEAVING THE THREAD POOL err=%p\n",
492         (void*)pthread_self(), getpid(), (void*)result);
493 
494     mOut.writeInt32(BC_EXIT_LOOPER);
495     talkWithDriver(false);
496 }
497 
stopProcess(bool immediate)498 void IPCThreadState::stopProcess(bool immediate)
499 {
500     //ALOGI("**** STOPPING PROCESS");
501     flushCommands();
502     int fd = mProcess->mDriverFD;
503     mProcess->mDriverFD = -1;
504     close(fd);
505     //kill(getpid(), SIGKILL);
506 }
507 
transact(int32_t handle,uint32_t code,const Parcel & data,Parcel * reply,uint32_t flags)508 status_t IPCThreadState::transact(int32_t handle,
509                                   uint32_t code, const Parcel& data,
510                                   Parcel* reply, uint32_t flags)
511 {
512     status_t err = data.errorCheck();
513 
514     flags |= TF_ACCEPT_FDS;
515 
516     IF_LOG_TRANSACTIONS() {
517         TextOutput::Bundle _b(alog);
518         alog << "BC_TRANSACTION thr " << (void*)pthread_self() << " / hand "
519             << handle << " / code " << TypeCode(code) << ": "
520             << indent << data << dedent << endl;
521     }
522 
523     if (err == NO_ERROR) {
524         LOG_ONEWAY(">>>> SEND from pid %d uid %d %s", getpid(), getuid(),
525             (flags & TF_ONE_WAY) == 0 ? "READ REPLY" : "ONE WAY");
526         err = writeTransactionData(BC_TRANSACTION, flags, handle, code, data, NULL);
527     }
528 
529     if (err != NO_ERROR) {
530         if (reply) reply->setError(err);
531         return (mLastError = err);
532     }
533 
534     if ((flags & TF_ONE_WAY) == 0) {
535         #if 0
536         if (code == 4) { // relayout
537             ALOGI(">>>>>> CALLING transaction 4");
538         } else {
539             ALOGI(">>>>>> CALLING transaction %d", code);
540         }
541         #endif
542         if (reply) {
543             err = waitForResponse(reply);
544         } else {
545             Parcel fakeReply;
546             err = waitForResponse(&fakeReply);
547         }
548         #if 0
549         if (code == 4) { // relayout
550             ALOGI("<<<<<< RETURNING transaction 4");
551         } else {
552             ALOGI("<<<<<< RETURNING transaction %d", code);
553         }
554         #endif
555 
556         IF_LOG_TRANSACTIONS() {
557             TextOutput::Bundle _b(alog);
558             alog << "BR_REPLY thr " << (void*)pthread_self() << " / hand "
559                 << handle << ": ";
560             if (reply) alog << indent << *reply << dedent << endl;
561             else alog << "(none requested)" << endl;
562         }
563     } else {
564         err = waitForResponse(NULL, NULL);
565     }
566 
567     return err;
568 }
569 
incStrongHandle(int32_t handle)570 void IPCThreadState::incStrongHandle(int32_t handle)
571 {
572     LOG_REMOTEREFS("IPCThreadState::incStrongHandle(%d)\n", handle);
573     mOut.writeInt32(BC_ACQUIRE);
574     mOut.writeInt32(handle);
575 }
576 
decStrongHandle(int32_t handle)577 void IPCThreadState::decStrongHandle(int32_t handle)
578 {
579     LOG_REMOTEREFS("IPCThreadState::decStrongHandle(%d)\n", handle);
580     mOut.writeInt32(BC_RELEASE);
581     mOut.writeInt32(handle);
582 }
583 
incWeakHandle(int32_t handle)584 void IPCThreadState::incWeakHandle(int32_t handle)
585 {
586     LOG_REMOTEREFS("IPCThreadState::incWeakHandle(%d)\n", handle);
587     mOut.writeInt32(BC_INCREFS);
588     mOut.writeInt32(handle);
589 }
590 
decWeakHandle(int32_t handle)591 void IPCThreadState::decWeakHandle(int32_t handle)
592 {
593     LOG_REMOTEREFS("IPCThreadState::decWeakHandle(%d)\n", handle);
594     mOut.writeInt32(BC_DECREFS);
595     mOut.writeInt32(handle);
596 }
597 
attemptIncStrongHandle(int32_t handle)598 status_t IPCThreadState::attemptIncStrongHandle(int32_t handle)
599 {
600     LOG_REMOTEREFS("IPCThreadState::attemptIncStrongHandle(%d)\n", handle);
601     mOut.writeInt32(BC_ATTEMPT_ACQUIRE);
602     mOut.writeInt32(0); // xxx was thread priority
603     mOut.writeInt32(handle);
604     status_t result = UNKNOWN_ERROR;
605 
606     waitForResponse(NULL, &result);
607 
608 #if LOG_REFCOUNTS
609     printf("IPCThreadState::attemptIncStrongHandle(%ld) = %s\n",
610         handle, result == NO_ERROR ? "SUCCESS" : "FAILURE");
611 #endif
612 
613     return result;
614 }
615 
expungeHandle(int32_t handle,IBinder * binder)616 void IPCThreadState::expungeHandle(int32_t handle, IBinder* binder)
617 {
618 #if LOG_REFCOUNTS
619     printf("IPCThreadState::expungeHandle(%ld)\n", handle);
620 #endif
621     self()->mProcess->expungeHandle(handle, binder);
622 }
623 
requestDeathNotification(int32_t handle,BpBinder * proxy)624 status_t IPCThreadState::requestDeathNotification(int32_t handle, BpBinder* proxy)
625 {
626     mOut.writeInt32(BC_REQUEST_DEATH_NOTIFICATION);
627     mOut.writeInt32((int32_t)handle);
628     mOut.writeInt32((int32_t)proxy);
629     return NO_ERROR;
630 }
631 
clearDeathNotification(int32_t handle,BpBinder * proxy)632 status_t IPCThreadState::clearDeathNotification(int32_t handle, BpBinder* proxy)
633 {
634     mOut.writeInt32(BC_CLEAR_DEATH_NOTIFICATION);
635     mOut.writeInt32((int32_t)handle);
636     mOut.writeInt32((int32_t)proxy);
637     return NO_ERROR;
638 }
639 
IPCThreadState()640 IPCThreadState::IPCThreadState()
641     : mProcess(ProcessState::self()),
642       mMyThreadId(androidGetTid()),
643       mStrictModePolicy(0),
644       mLastTransactionBinderFlags(0)
645 {
646     pthread_setspecific(gTLS, this);
647     clearCaller();
648     mIn.setDataCapacity(256);
649     mOut.setDataCapacity(256);
650 }
651 
~IPCThreadState()652 IPCThreadState::~IPCThreadState()
653 {
654 }
655 
sendReply(const Parcel & reply,uint32_t flags)656 status_t IPCThreadState::sendReply(const Parcel& reply, uint32_t flags)
657 {
658     status_t err;
659     status_t statusBuffer;
660     err = writeTransactionData(BC_REPLY, flags, -1, 0, reply, &statusBuffer);
661     if (err < NO_ERROR) return err;
662 
663     return waitForResponse(NULL, NULL);
664 }
665 
waitForResponse(Parcel * reply,status_t * acquireResult)666 status_t IPCThreadState::waitForResponse(Parcel *reply, status_t *acquireResult)
667 {
668     int32_t cmd;
669     int32_t err;
670 
671     while (1) {
672         if ((err=talkWithDriver()) < NO_ERROR) break;
673         err = mIn.errorCheck();
674         if (err < NO_ERROR) break;
675         if (mIn.dataAvail() == 0) continue;
676 
677         cmd = mIn.readInt32();
678 
679         IF_LOG_COMMANDS() {
680             alog << "Processing waitForResponse Command: "
681                 << getReturnString(cmd) << endl;
682         }
683 
684         switch (cmd) {
685         case BR_TRANSACTION_COMPLETE:
686             if (!reply && !acquireResult) goto finish;
687             break;
688 
689         case BR_DEAD_REPLY:
690             err = DEAD_OBJECT;
691             goto finish;
692 
693         case BR_FAILED_REPLY:
694             err = FAILED_TRANSACTION;
695             goto finish;
696 
697         case BR_ACQUIRE_RESULT:
698             {
699                 ALOG_ASSERT(acquireResult != NULL, "Unexpected brACQUIRE_RESULT");
700                 const int32_t result = mIn.readInt32();
701                 if (!acquireResult) continue;
702                 *acquireResult = result ? NO_ERROR : INVALID_OPERATION;
703             }
704             goto finish;
705 
706         case BR_REPLY:
707             {
708                 binder_transaction_data tr;
709                 err = mIn.read(&tr, sizeof(tr));
710                 ALOG_ASSERT(err == NO_ERROR, "Not enough command data for brREPLY");
711                 if (err != NO_ERROR) goto finish;
712 
713                 if (reply) {
714                     if ((tr.flags & TF_STATUS_CODE) == 0) {
715                         reply->ipcSetDataReference(
716                             reinterpret_cast<const uint8_t*>(tr.data.ptr.buffer),
717                             tr.data_size,
718                             reinterpret_cast<const size_t*>(tr.data.ptr.offsets),
719                             tr.offsets_size/sizeof(size_t),
720                             freeBuffer, this);
721                     } else {
722                         err = *static_cast<const status_t*>(tr.data.ptr.buffer);
723                         freeBuffer(NULL,
724                             reinterpret_cast<const uint8_t*>(tr.data.ptr.buffer),
725                             tr.data_size,
726                             reinterpret_cast<const size_t*>(tr.data.ptr.offsets),
727                             tr.offsets_size/sizeof(size_t), this);
728                     }
729                 } else {
730                     freeBuffer(NULL,
731                         reinterpret_cast<const uint8_t*>(tr.data.ptr.buffer),
732                         tr.data_size,
733                         reinterpret_cast<const size_t*>(tr.data.ptr.offsets),
734                         tr.offsets_size/sizeof(size_t), this);
735                     continue;
736                 }
737             }
738             goto finish;
739 
740         default:
741             err = executeCommand(cmd);
742             if (err != NO_ERROR) goto finish;
743             break;
744         }
745     }
746 
747 finish:
748     if (err != NO_ERROR) {
749         if (acquireResult) *acquireResult = err;
750         if (reply) reply->setError(err);
751         mLastError = err;
752     }
753 
754     return err;
755 }
756 
talkWithDriver(bool doReceive)757 status_t IPCThreadState::talkWithDriver(bool doReceive)
758 {
759     if (mProcess->mDriverFD <= 0) {
760         return -EBADF;
761     }
762 
763     binder_write_read bwr;
764 
765     // Is the read buffer empty?
766     const bool needRead = mIn.dataPosition() >= mIn.dataSize();
767 
768     // We don't want to write anything if we are still reading
769     // from data left in the input buffer and the caller
770     // has requested to read the next data.
771     const size_t outAvail = (!doReceive || needRead) ? mOut.dataSize() : 0;
772 
773     bwr.write_size = outAvail;
774     bwr.write_buffer = (long unsigned int)mOut.data();
775 
776     // This is what we'll read.
777     if (doReceive && needRead) {
778         bwr.read_size = mIn.dataCapacity();
779         bwr.read_buffer = (long unsigned int)mIn.data();
780     } else {
781         bwr.read_size = 0;
782         bwr.read_buffer = 0;
783     }
784 
785     IF_LOG_COMMANDS() {
786         TextOutput::Bundle _b(alog);
787         if (outAvail != 0) {
788             alog << "Sending commands to driver: " << indent;
789             const void* cmds = (const void*)bwr.write_buffer;
790             const void* end = ((const uint8_t*)cmds)+bwr.write_size;
791             alog << HexDump(cmds, bwr.write_size) << endl;
792             while (cmds < end) cmds = printCommand(alog, cmds);
793             alog << dedent;
794         }
795         alog << "Size of receive buffer: " << bwr.read_size
796             << ", needRead: " << needRead << ", doReceive: " << doReceive << endl;
797     }
798 
799     // Return immediately if there is nothing to do.
800     if ((bwr.write_size == 0) && (bwr.read_size == 0)) return NO_ERROR;
801 
802     bwr.write_consumed = 0;
803     bwr.read_consumed = 0;
804     status_t err;
805     do {
806         IF_LOG_COMMANDS() {
807             alog << "About to read/write, write size = " << mOut.dataSize() << endl;
808         }
809 #if defined(HAVE_ANDROID_OS)
810         if (ioctl(mProcess->mDriverFD, BINDER_WRITE_READ, &bwr) >= 0)
811             err = NO_ERROR;
812         else
813             err = -errno;
814 #else
815         err = INVALID_OPERATION;
816 #endif
817         if (mProcess->mDriverFD <= 0) {
818             err = -EBADF;
819         }
820         IF_LOG_COMMANDS() {
821             alog << "Finished read/write, write size = " << mOut.dataSize() << endl;
822         }
823     } while (err == -EINTR);
824 
825     IF_LOG_COMMANDS() {
826         alog << "Our err: " << (void*)err << ", write consumed: "
827             << bwr.write_consumed << " (of " << mOut.dataSize()
828 			<< "), read consumed: " << bwr.read_consumed << endl;
829     }
830 
831     if (err >= NO_ERROR) {
832         if (bwr.write_consumed > 0) {
833             if (bwr.write_consumed < (ssize_t)mOut.dataSize())
834                 mOut.remove(0, bwr.write_consumed);
835             else
836                 mOut.setDataSize(0);
837         }
838         if (bwr.read_consumed > 0) {
839             mIn.setDataSize(bwr.read_consumed);
840             mIn.setDataPosition(0);
841         }
842         IF_LOG_COMMANDS() {
843             TextOutput::Bundle _b(alog);
844             alog << "Remaining data size: " << mOut.dataSize() << endl;
845             alog << "Received commands from driver: " << indent;
846             const void* cmds = mIn.data();
847             const void* end = mIn.data() + mIn.dataSize();
848             alog << HexDump(cmds, mIn.dataSize()) << endl;
849             while (cmds < end) cmds = printReturnCommand(alog, cmds);
850             alog << dedent;
851         }
852         return NO_ERROR;
853     }
854 
855     return err;
856 }
857 
writeTransactionData(int32_t cmd,uint32_t binderFlags,int32_t handle,uint32_t code,const Parcel & data,status_t * statusBuffer)858 status_t IPCThreadState::writeTransactionData(int32_t cmd, uint32_t binderFlags,
859     int32_t handle, uint32_t code, const Parcel& data, status_t* statusBuffer)
860 {
861     binder_transaction_data tr;
862 
863     tr.target.handle = handle;
864     tr.code = code;
865     tr.flags = binderFlags;
866     tr.cookie = 0;
867     tr.sender_pid = 0;
868     tr.sender_euid = 0;
869 
870     const status_t err = data.errorCheck();
871     if (err == NO_ERROR) {
872         tr.data_size = data.ipcDataSize();
873         tr.data.ptr.buffer = data.ipcData();
874         tr.offsets_size = data.ipcObjectsCount()*sizeof(size_t);
875         tr.data.ptr.offsets = data.ipcObjects();
876     } else if (statusBuffer) {
877         tr.flags |= TF_STATUS_CODE;
878         *statusBuffer = err;
879         tr.data_size = sizeof(status_t);
880         tr.data.ptr.buffer = statusBuffer;
881         tr.offsets_size = 0;
882         tr.data.ptr.offsets = NULL;
883     } else {
884         return (mLastError = err);
885     }
886 
887     mOut.writeInt32(cmd);
888     mOut.write(&tr, sizeof(tr));
889 
890     return NO_ERROR;
891 }
892 
893 sp<BBinder> the_context_object;
894 
setTheContextObject(sp<BBinder> obj)895 void setTheContextObject(sp<BBinder> obj)
896 {
897     the_context_object = obj;
898 }
899 
executeCommand(int32_t cmd)900 status_t IPCThreadState::executeCommand(int32_t cmd)
901 {
902     BBinder* obj;
903     RefBase::weakref_type* refs;
904     status_t result = NO_ERROR;
905 
906     switch (cmd) {
907     case BR_ERROR:
908         result = mIn.readInt32();
909         break;
910 
911     case BR_OK:
912         break;
913 
914     case BR_ACQUIRE:
915         refs = (RefBase::weakref_type*)mIn.readInt32();
916         obj = (BBinder*)mIn.readInt32();
917         ALOG_ASSERT(refs->refBase() == obj,
918                    "BR_ACQUIRE: object %p does not match cookie %p (expected %p)",
919                    refs, obj, refs->refBase());
920         obj->incStrong(mProcess.get());
921         IF_LOG_REMOTEREFS() {
922             LOG_REMOTEREFS("BR_ACQUIRE from driver on %p", obj);
923             obj->printRefs();
924         }
925         mOut.writeInt32(BC_ACQUIRE_DONE);
926         mOut.writeInt32((int32_t)refs);
927         mOut.writeInt32((int32_t)obj);
928         break;
929 
930     case BR_RELEASE:
931         refs = (RefBase::weakref_type*)mIn.readInt32();
932         obj = (BBinder*)mIn.readInt32();
933         ALOG_ASSERT(refs->refBase() == obj,
934                    "BR_RELEASE: object %p does not match cookie %p (expected %p)",
935                    refs, obj, refs->refBase());
936         IF_LOG_REMOTEREFS() {
937             LOG_REMOTEREFS("BR_RELEASE from driver on %p", obj);
938             obj->printRefs();
939         }
940         mPendingStrongDerefs.push(obj);
941         break;
942 
943     case BR_INCREFS:
944         refs = (RefBase::weakref_type*)mIn.readInt32();
945         obj = (BBinder*)mIn.readInt32();
946         refs->incWeak(mProcess.get());
947         mOut.writeInt32(BC_INCREFS_DONE);
948         mOut.writeInt32((int32_t)refs);
949         mOut.writeInt32((int32_t)obj);
950         break;
951 
952     case BR_DECREFS:
953         refs = (RefBase::weakref_type*)mIn.readInt32();
954         obj = (BBinder*)mIn.readInt32();
955         // NOTE: This assertion is not valid, because the object may no
956         // longer exist (thus the (BBinder*)cast above resulting in a different
957         // memory address).
958         //ALOG_ASSERT(refs->refBase() == obj,
959         //           "BR_DECREFS: object %p does not match cookie %p (expected %p)",
960         //           refs, obj, refs->refBase());
961         mPendingWeakDerefs.push(refs);
962         break;
963 
964     case BR_ATTEMPT_ACQUIRE:
965         refs = (RefBase::weakref_type*)mIn.readInt32();
966         obj = (BBinder*)mIn.readInt32();
967 
968         {
969             const bool success = refs->attemptIncStrong(mProcess.get());
970             ALOG_ASSERT(success && refs->refBase() == obj,
971                        "BR_ATTEMPT_ACQUIRE: object %p does not match cookie %p (expected %p)",
972                        refs, obj, refs->refBase());
973 
974             mOut.writeInt32(BC_ACQUIRE_RESULT);
975             mOut.writeInt32((int32_t)success);
976         }
977         break;
978 
979     case BR_TRANSACTION:
980         {
981             binder_transaction_data tr;
982             result = mIn.read(&tr, sizeof(tr));
983             ALOG_ASSERT(result == NO_ERROR,
984                 "Not enough command data for brTRANSACTION");
985             if (result != NO_ERROR) break;
986 
987             Parcel buffer;
988             buffer.ipcSetDataReference(
989                 reinterpret_cast<const uint8_t*>(tr.data.ptr.buffer),
990                 tr.data_size,
991                 reinterpret_cast<const size_t*>(tr.data.ptr.offsets),
992                 tr.offsets_size/sizeof(size_t), freeBuffer, this);
993 
994             const pid_t origPid = mCallingPid;
995             const uid_t origUid = mCallingUid;
996 
997             mCallingPid = tr.sender_pid;
998             mCallingUid = tr.sender_euid;
999 
1000             int curPrio = getpriority(PRIO_PROCESS, mMyThreadId);
1001             if (gDisableBackgroundScheduling) {
1002                 if (curPrio > ANDROID_PRIORITY_NORMAL) {
1003                     // We have inherited a reduced priority from the caller, but do not
1004                     // want to run in that state in this process.  The driver set our
1005                     // priority already (though not our scheduling class), so bounce
1006                     // it back to the default before invoking the transaction.
1007                     setpriority(PRIO_PROCESS, mMyThreadId, ANDROID_PRIORITY_NORMAL);
1008                 }
1009             } else {
1010                 if (curPrio >= ANDROID_PRIORITY_BACKGROUND) {
1011                     // We want to use the inherited priority from the caller.
1012                     // Ensure this thread is in the background scheduling class,
1013                     // since the driver won't modify scheduling classes for us.
1014                     // The scheduling group is reset to default by the caller
1015                     // once this method returns after the transaction is complete.
1016                     set_sched_policy(mMyThreadId, SP_BACKGROUND);
1017                 }
1018             }
1019 
1020             //ALOGI(">>>> TRANSACT from pid %d uid %d\n", mCallingPid, mCallingUid);
1021 
1022             Parcel reply;
1023             IF_LOG_TRANSACTIONS() {
1024                 TextOutput::Bundle _b(alog);
1025                 alog << "BR_TRANSACTION thr " << (void*)pthread_self()
1026                     << " / obj " << tr.target.ptr << " / code "
1027                     << TypeCode(tr.code) << ": " << indent << buffer
1028                     << dedent << endl
1029                     << "Data addr = "
1030                     << reinterpret_cast<const uint8_t*>(tr.data.ptr.buffer)
1031                     << ", offsets addr="
1032                     << reinterpret_cast<const size_t*>(tr.data.ptr.offsets) << endl;
1033             }
1034             if (tr.target.ptr) {
1035                 sp<BBinder> b((BBinder*)tr.cookie);
1036                 const status_t error = b->transact(tr.code, buffer, &reply, tr.flags);
1037                 if (error < NO_ERROR) reply.setError(error);
1038 
1039             } else {
1040                 const status_t error = the_context_object->transact(tr.code, buffer, &reply, tr.flags);
1041                 if (error < NO_ERROR) reply.setError(error);
1042             }
1043 
1044             //ALOGI("<<<< TRANSACT from pid %d restore pid %d uid %d\n",
1045             //     mCallingPid, origPid, origUid);
1046 
1047             if ((tr.flags & TF_ONE_WAY) == 0) {
1048                 LOG_ONEWAY("Sending reply to %d!", mCallingPid);
1049                 sendReply(reply, 0);
1050             } else {
1051                 LOG_ONEWAY("NOT sending reply to %d!", mCallingPid);
1052             }
1053 
1054             mCallingPid = origPid;
1055             mCallingUid = origUid;
1056 
1057             IF_LOG_TRANSACTIONS() {
1058                 TextOutput::Bundle _b(alog);
1059                 alog << "BC_REPLY thr " << (void*)pthread_self() << " / obj "
1060                     << tr.target.ptr << ": " << indent << reply << dedent << endl;
1061             }
1062 
1063         }
1064         break;
1065 
1066     case BR_DEAD_BINDER:
1067         {
1068             BpBinder *proxy = (BpBinder*)mIn.readInt32();
1069             proxy->sendObituary();
1070             mOut.writeInt32(BC_DEAD_BINDER_DONE);
1071             mOut.writeInt32((int32_t)proxy);
1072         } break;
1073 
1074     case BR_CLEAR_DEATH_NOTIFICATION_DONE:
1075         {
1076             BpBinder *proxy = (BpBinder*)mIn.readInt32();
1077             proxy->getWeakRefs()->decWeak(proxy);
1078         } break;
1079 
1080     case BR_FINISHED:
1081         result = TIMED_OUT;
1082         break;
1083 
1084     case BR_NOOP:
1085         break;
1086 
1087     case BR_SPAWN_LOOPER:
1088         mProcess->spawnPooledThread(false);
1089         break;
1090 
1091     default:
1092         printf("*** BAD COMMAND %d received from Binder driver\n", cmd);
1093         result = UNKNOWN_ERROR;
1094         break;
1095     }
1096 
1097     if (result != NO_ERROR) {
1098         mLastError = result;
1099     }
1100 
1101     return result;
1102 }
1103 
threadDestructor(void * st)1104 void IPCThreadState::threadDestructor(void *st)
1105 {
1106 	IPCThreadState* const self = static_cast<IPCThreadState*>(st);
1107 	if (self) {
1108 		self->flushCommands();
1109 #if defined(HAVE_ANDROID_OS)
1110         if (self->mProcess->mDriverFD > 0) {
1111             ioctl(self->mProcess->mDriverFD, BINDER_THREAD_EXIT, 0);
1112         }
1113 #endif
1114 		delete self;
1115 	}
1116 }
1117 
1118 
freeBuffer(Parcel * parcel,const uint8_t * data,size_t dataSize,const size_t * objects,size_t objectsSize,void * cookie)1119 void IPCThreadState::freeBuffer(Parcel* parcel, const uint8_t* data, size_t dataSize,
1120                                 const size_t* objects, size_t objectsSize,
1121                                 void* cookie)
1122 {
1123     //ALOGI("Freeing parcel %p", &parcel);
1124     IF_LOG_COMMANDS() {
1125         alog << "Writing BC_FREE_BUFFER for " << data << endl;
1126     }
1127     ALOG_ASSERT(data != NULL, "Called with NULL data");
1128     if (parcel != NULL) parcel->closeFileDescriptors();
1129     IPCThreadState* state = self();
1130     state->mOut.writeInt32(BC_FREE_BUFFER);
1131     state->mOut.writeInt32((int32_t)data);
1132 }
1133 
1134 }; // namespace android
1135