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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         }
470 
471         // After executing the command, ensure that the thread is returned to the
472         // foreground cgroup before rejoining the pool.  The driver takes care of
473         // restoring the priority, but doesn't do anything with cgroups so we
474         // need to take care of that here in userspace.  Note that we do make
475         // sure to go in the foreground after executing a transaction, but
476         // there are other callbacks into user code that could have changed
477         // our group so we want to make absolutely sure it is put back.
478         set_sched_policy(mMyThreadId, SP_FOREGROUND);
479 
480         // Let this thread exit the thread pool if it is no longer
481         // needed and it is not the main process thread.
482         if(result == TIMED_OUT && !isMain) {
483             break;
484         }
485     } while (result != -ECONNREFUSED && result != -EBADF);
486 
487     LOG_THREADPOOL("**** THREAD %p (PID %d) IS LEAVING THE THREAD POOL err=%p\n",
488         (void*)pthread_self(), getpid(), (void*)result);
489 
490     mOut.writeInt32(BC_EXIT_LOOPER);
491     talkWithDriver(false);
492 }
493 
stopProcess(bool immediate)494 void IPCThreadState::stopProcess(bool immediate)
495 {
496     //ALOGI("**** STOPPING PROCESS");
497     flushCommands();
498     int fd = mProcess->mDriverFD;
499     mProcess->mDriverFD = -1;
500     close(fd);
501     //kill(getpid(), SIGKILL);
502 }
503 
transact(int32_t handle,uint32_t code,const Parcel & data,Parcel * reply,uint32_t flags)504 status_t IPCThreadState::transact(int32_t handle,
505                                   uint32_t code, const Parcel& data,
506                                   Parcel* reply, uint32_t flags)
507 {
508     status_t err = data.errorCheck();
509 
510     flags |= TF_ACCEPT_FDS;
511 
512     IF_LOG_TRANSACTIONS() {
513         TextOutput::Bundle _b(alog);
514         alog << "BC_TRANSACTION thr " << (void*)pthread_self() << " / hand "
515             << handle << " / code " << TypeCode(code) << ": "
516             << indent << data << dedent << endl;
517     }
518 
519     if (err == NO_ERROR) {
520         LOG_ONEWAY(">>>> SEND from pid %d uid %d %s", getpid(), getuid(),
521             (flags & TF_ONE_WAY) == 0 ? "READ REPLY" : "ONE WAY");
522         err = writeTransactionData(BC_TRANSACTION, flags, handle, code, data, NULL);
523     }
524 
525     if (err != NO_ERROR) {
526         if (reply) reply->setError(err);
527         return (mLastError = err);
528     }
529 
530     if ((flags & TF_ONE_WAY) == 0) {
531         #if 0
532         if (code == 4) { // relayout
533             ALOGI(">>>>>> CALLING transaction 4");
534         } else {
535             ALOGI(">>>>>> CALLING transaction %d", code);
536         }
537         #endif
538         if (reply) {
539             err = waitForResponse(reply);
540         } else {
541             Parcel fakeReply;
542             err = waitForResponse(&fakeReply);
543         }
544         #if 0
545         if (code == 4) { // relayout
546             ALOGI("<<<<<< RETURNING transaction 4");
547         } else {
548             ALOGI("<<<<<< RETURNING transaction %d", code);
549         }
550         #endif
551 
552         IF_LOG_TRANSACTIONS() {
553             TextOutput::Bundle _b(alog);
554             alog << "BR_REPLY thr " << (void*)pthread_self() << " / hand "
555                 << handle << ": ";
556             if (reply) alog << indent << *reply << dedent << endl;
557             else alog << "(none requested)" << endl;
558         }
559     } else {
560         err = waitForResponse(NULL, NULL);
561     }
562 
563     return err;
564 }
565 
incStrongHandle(int32_t handle)566 void IPCThreadState::incStrongHandle(int32_t handle)
567 {
568     LOG_REMOTEREFS("IPCThreadState::incStrongHandle(%d)\n", handle);
569     mOut.writeInt32(BC_ACQUIRE);
570     mOut.writeInt32(handle);
571 }
572 
decStrongHandle(int32_t handle)573 void IPCThreadState::decStrongHandle(int32_t handle)
574 {
575     LOG_REMOTEREFS("IPCThreadState::decStrongHandle(%d)\n", handle);
576     mOut.writeInt32(BC_RELEASE);
577     mOut.writeInt32(handle);
578 }
579 
incWeakHandle(int32_t handle)580 void IPCThreadState::incWeakHandle(int32_t handle)
581 {
582     LOG_REMOTEREFS("IPCThreadState::incWeakHandle(%d)\n", handle);
583     mOut.writeInt32(BC_INCREFS);
584     mOut.writeInt32(handle);
585 }
586 
decWeakHandle(int32_t handle)587 void IPCThreadState::decWeakHandle(int32_t handle)
588 {
589     LOG_REMOTEREFS("IPCThreadState::decWeakHandle(%d)\n", handle);
590     mOut.writeInt32(BC_DECREFS);
591     mOut.writeInt32(handle);
592 }
593 
attemptIncStrongHandle(int32_t handle)594 status_t IPCThreadState::attemptIncStrongHandle(int32_t handle)
595 {
596     LOG_REMOTEREFS("IPCThreadState::attemptIncStrongHandle(%d)\n", handle);
597     mOut.writeInt32(BC_ATTEMPT_ACQUIRE);
598     mOut.writeInt32(0); // xxx was thread priority
599     mOut.writeInt32(handle);
600     status_t result = UNKNOWN_ERROR;
601 
602     waitForResponse(NULL, &result);
603 
604 #if LOG_REFCOUNTS
605     printf("IPCThreadState::attemptIncStrongHandle(%ld) = %s\n",
606         handle, result == NO_ERROR ? "SUCCESS" : "FAILURE");
607 #endif
608 
609     return result;
610 }
611 
expungeHandle(int32_t handle,IBinder * binder)612 void IPCThreadState::expungeHandle(int32_t handle, IBinder* binder)
613 {
614 #if LOG_REFCOUNTS
615     printf("IPCThreadState::expungeHandle(%ld)\n", handle);
616 #endif
617     self()->mProcess->expungeHandle(handle, binder);
618 }
619 
requestDeathNotification(int32_t handle,BpBinder * proxy)620 status_t IPCThreadState::requestDeathNotification(int32_t handle, BpBinder* proxy)
621 {
622     mOut.writeInt32(BC_REQUEST_DEATH_NOTIFICATION);
623     mOut.writeInt32((int32_t)handle);
624     mOut.writeInt32((int32_t)proxy);
625     return NO_ERROR;
626 }
627 
clearDeathNotification(int32_t handle,BpBinder * proxy)628 status_t IPCThreadState::clearDeathNotification(int32_t handle, BpBinder* proxy)
629 {
630     mOut.writeInt32(BC_CLEAR_DEATH_NOTIFICATION);
631     mOut.writeInt32((int32_t)handle);
632     mOut.writeInt32((int32_t)proxy);
633     return NO_ERROR;
634 }
635 
IPCThreadState()636 IPCThreadState::IPCThreadState()
637     : mProcess(ProcessState::self()),
638       mMyThreadId(androidGetTid()),
639       mStrictModePolicy(0),
640       mLastTransactionBinderFlags(0)
641 {
642     pthread_setspecific(gTLS, this);
643     clearCaller();
644     mIn.setDataCapacity(256);
645     mOut.setDataCapacity(256);
646 }
647 
~IPCThreadState()648 IPCThreadState::~IPCThreadState()
649 {
650 }
651 
sendReply(const Parcel & reply,uint32_t flags)652 status_t IPCThreadState::sendReply(const Parcel& reply, uint32_t flags)
653 {
654     status_t err;
655     status_t statusBuffer;
656     err = writeTransactionData(BC_REPLY, flags, -1, 0, reply, &statusBuffer);
657     if (err < NO_ERROR) return err;
658 
659     return waitForResponse(NULL, NULL);
660 }
661 
waitForResponse(Parcel * reply,status_t * acquireResult)662 status_t IPCThreadState::waitForResponse(Parcel *reply, status_t *acquireResult)
663 {
664     int32_t cmd;
665     int32_t err;
666 
667     while (1) {
668         if ((err=talkWithDriver()) < NO_ERROR) break;
669         err = mIn.errorCheck();
670         if (err < NO_ERROR) break;
671         if (mIn.dataAvail() == 0) continue;
672 
673         cmd = mIn.readInt32();
674 
675         IF_LOG_COMMANDS() {
676             alog << "Processing waitForResponse Command: "
677                 << getReturnString(cmd) << endl;
678         }
679 
680         switch (cmd) {
681         case BR_TRANSACTION_COMPLETE:
682             if (!reply && !acquireResult) goto finish;
683             break;
684 
685         case BR_DEAD_REPLY:
686             err = DEAD_OBJECT;
687             goto finish;
688 
689         case BR_FAILED_REPLY:
690             err = FAILED_TRANSACTION;
691             goto finish;
692 
693         case BR_ACQUIRE_RESULT:
694             {
695                 ALOG_ASSERT(acquireResult != NULL, "Unexpected brACQUIRE_RESULT");
696                 const int32_t result = mIn.readInt32();
697                 if (!acquireResult) continue;
698                 *acquireResult = result ? NO_ERROR : INVALID_OPERATION;
699             }
700             goto finish;
701 
702         case BR_REPLY:
703             {
704                 binder_transaction_data tr;
705                 err = mIn.read(&tr, sizeof(tr));
706                 ALOG_ASSERT(err == NO_ERROR, "Not enough command data for brREPLY");
707                 if (err != NO_ERROR) goto finish;
708 
709                 if (reply) {
710                     if ((tr.flags & TF_STATUS_CODE) == 0) {
711                         reply->ipcSetDataReference(
712                             reinterpret_cast<const uint8_t*>(tr.data.ptr.buffer),
713                             tr.data_size,
714                             reinterpret_cast<const size_t*>(tr.data.ptr.offsets),
715                             tr.offsets_size/sizeof(size_t),
716                             freeBuffer, this);
717                     } else {
718                         err = *static_cast<const status_t*>(tr.data.ptr.buffer);
719                         freeBuffer(NULL,
720                             reinterpret_cast<const uint8_t*>(tr.data.ptr.buffer),
721                             tr.data_size,
722                             reinterpret_cast<const size_t*>(tr.data.ptr.offsets),
723                             tr.offsets_size/sizeof(size_t), this);
724                     }
725                 } else {
726                     freeBuffer(NULL,
727                         reinterpret_cast<const uint8_t*>(tr.data.ptr.buffer),
728                         tr.data_size,
729                         reinterpret_cast<const size_t*>(tr.data.ptr.offsets),
730                         tr.offsets_size/sizeof(size_t), this);
731                     continue;
732                 }
733             }
734             goto finish;
735 
736         default:
737             err = executeCommand(cmd);
738             if (err != NO_ERROR) goto finish;
739             break;
740         }
741     }
742 
743 finish:
744     if (err != NO_ERROR) {
745         if (acquireResult) *acquireResult = err;
746         if (reply) reply->setError(err);
747         mLastError = err;
748     }
749 
750     return err;
751 }
752 
talkWithDriver(bool doReceive)753 status_t IPCThreadState::talkWithDriver(bool doReceive)
754 {
755     if (mProcess->mDriverFD <= 0) {
756         return -EBADF;
757     }
758 
759     binder_write_read bwr;
760 
761     // Is the read buffer empty?
762     const bool needRead = mIn.dataPosition() >= mIn.dataSize();
763 
764     // We don't want to write anything if we are still reading
765     // from data left in the input buffer and the caller
766     // has requested to read the next data.
767     const size_t outAvail = (!doReceive || needRead) ? mOut.dataSize() : 0;
768 
769     bwr.write_size = outAvail;
770     bwr.write_buffer = (long unsigned int)mOut.data();
771 
772     // This is what we'll read.
773     if (doReceive && needRead) {
774         bwr.read_size = mIn.dataCapacity();
775         bwr.read_buffer = (long unsigned int)mIn.data();
776     } else {
777         bwr.read_size = 0;
778         bwr.read_buffer = 0;
779     }
780 
781     IF_LOG_COMMANDS() {
782         TextOutput::Bundle _b(alog);
783         if (outAvail != 0) {
784             alog << "Sending commands to driver: " << indent;
785             const void* cmds = (const void*)bwr.write_buffer;
786             const void* end = ((const uint8_t*)cmds)+bwr.write_size;
787             alog << HexDump(cmds, bwr.write_size) << endl;
788             while (cmds < end) cmds = printCommand(alog, cmds);
789             alog << dedent;
790         }
791         alog << "Size of receive buffer: " << bwr.read_size
792             << ", needRead: " << needRead << ", doReceive: " << doReceive << endl;
793     }
794 
795     // Return immediately if there is nothing to do.
796     if ((bwr.write_size == 0) && (bwr.read_size == 0)) return NO_ERROR;
797 
798     bwr.write_consumed = 0;
799     bwr.read_consumed = 0;
800     status_t err;
801     do {
802         IF_LOG_COMMANDS() {
803             alog << "About to read/write, write size = " << mOut.dataSize() << endl;
804         }
805 #if defined(HAVE_ANDROID_OS)
806         if (ioctl(mProcess->mDriverFD, BINDER_WRITE_READ, &bwr) >= 0)
807             err = NO_ERROR;
808         else
809             err = -errno;
810 #else
811         err = INVALID_OPERATION;
812 #endif
813         if (mProcess->mDriverFD <= 0) {
814             err = -EBADF;
815         }
816         IF_LOG_COMMANDS() {
817             alog << "Finished read/write, write size = " << mOut.dataSize() << endl;
818         }
819     } while (err == -EINTR);
820 
821     IF_LOG_COMMANDS() {
822         alog << "Our err: " << (void*)err << ", write consumed: "
823             << bwr.write_consumed << " (of " << mOut.dataSize()
824 			<< "), read consumed: " << bwr.read_consumed << endl;
825     }
826 
827     if (err >= NO_ERROR) {
828         if (bwr.write_consumed > 0) {
829             if (bwr.write_consumed < (ssize_t)mOut.dataSize())
830                 mOut.remove(0, bwr.write_consumed);
831             else
832                 mOut.setDataSize(0);
833         }
834         if (bwr.read_consumed > 0) {
835             mIn.setDataSize(bwr.read_consumed);
836             mIn.setDataPosition(0);
837         }
838         IF_LOG_COMMANDS() {
839             TextOutput::Bundle _b(alog);
840             alog << "Remaining data size: " << mOut.dataSize() << endl;
841             alog << "Received commands from driver: " << indent;
842             const void* cmds = mIn.data();
843             const void* end = mIn.data() + mIn.dataSize();
844             alog << HexDump(cmds, mIn.dataSize()) << endl;
845             while (cmds < end) cmds = printReturnCommand(alog, cmds);
846             alog << dedent;
847         }
848         return NO_ERROR;
849     }
850 
851     return err;
852 }
853 
writeTransactionData(int32_t cmd,uint32_t binderFlags,int32_t handle,uint32_t code,const Parcel & data,status_t * statusBuffer)854 status_t IPCThreadState::writeTransactionData(int32_t cmd, uint32_t binderFlags,
855     int32_t handle, uint32_t code, const Parcel& data, status_t* statusBuffer)
856 {
857     binder_transaction_data tr;
858 
859     tr.target.handle = handle;
860     tr.code = code;
861     tr.flags = binderFlags;
862     tr.cookie = 0;
863     tr.sender_pid = 0;
864     tr.sender_euid = 0;
865 
866     const status_t err = data.errorCheck();
867     if (err == NO_ERROR) {
868         tr.data_size = data.ipcDataSize();
869         tr.data.ptr.buffer = data.ipcData();
870         tr.offsets_size = data.ipcObjectsCount()*sizeof(size_t);
871         tr.data.ptr.offsets = data.ipcObjects();
872     } else if (statusBuffer) {
873         tr.flags |= TF_STATUS_CODE;
874         *statusBuffer = err;
875         tr.data_size = sizeof(status_t);
876         tr.data.ptr.buffer = statusBuffer;
877         tr.offsets_size = 0;
878         tr.data.ptr.offsets = NULL;
879     } else {
880         return (mLastError = err);
881     }
882 
883     mOut.writeInt32(cmd);
884     mOut.write(&tr, sizeof(tr));
885 
886     return NO_ERROR;
887 }
888 
889 sp<BBinder> the_context_object;
890 
setTheContextObject(sp<BBinder> obj)891 void setTheContextObject(sp<BBinder> obj)
892 {
893     the_context_object = obj;
894 }
895 
executeCommand(int32_t cmd)896 status_t IPCThreadState::executeCommand(int32_t cmd)
897 {
898     BBinder* obj;
899     RefBase::weakref_type* refs;
900     status_t result = NO_ERROR;
901 
902     switch (cmd) {
903     case BR_ERROR:
904         result = mIn.readInt32();
905         break;
906 
907     case BR_OK:
908         break;
909 
910     case BR_ACQUIRE:
911         refs = (RefBase::weakref_type*)mIn.readInt32();
912         obj = (BBinder*)mIn.readInt32();
913         ALOG_ASSERT(refs->refBase() == obj,
914                    "BR_ACQUIRE: object %p does not match cookie %p (expected %p)",
915                    refs, obj, refs->refBase());
916         obj->incStrong(mProcess.get());
917         IF_LOG_REMOTEREFS() {
918             LOG_REMOTEREFS("BR_ACQUIRE from driver on %p", obj);
919             obj->printRefs();
920         }
921         mOut.writeInt32(BC_ACQUIRE_DONE);
922         mOut.writeInt32((int32_t)refs);
923         mOut.writeInt32((int32_t)obj);
924         break;
925 
926     case BR_RELEASE:
927         refs = (RefBase::weakref_type*)mIn.readInt32();
928         obj = (BBinder*)mIn.readInt32();
929         ALOG_ASSERT(refs->refBase() == obj,
930                    "BR_RELEASE: object %p does not match cookie %p (expected %p)",
931                    refs, obj, refs->refBase());
932         IF_LOG_REMOTEREFS() {
933             LOG_REMOTEREFS("BR_RELEASE from driver on %p", obj);
934             obj->printRefs();
935         }
936         mPendingStrongDerefs.push(obj);
937         break;
938 
939     case BR_INCREFS:
940         refs = (RefBase::weakref_type*)mIn.readInt32();
941         obj = (BBinder*)mIn.readInt32();
942         refs->incWeak(mProcess.get());
943         mOut.writeInt32(BC_INCREFS_DONE);
944         mOut.writeInt32((int32_t)refs);
945         mOut.writeInt32((int32_t)obj);
946         break;
947 
948     case BR_DECREFS:
949         refs = (RefBase::weakref_type*)mIn.readInt32();
950         obj = (BBinder*)mIn.readInt32();
951         // NOTE: This assertion is not valid, because the object may no
952         // longer exist (thus the (BBinder*)cast above resulting in a different
953         // memory address).
954         //ALOG_ASSERT(refs->refBase() == obj,
955         //           "BR_DECREFS: object %p does not match cookie %p (expected %p)",
956         //           refs, obj, refs->refBase());
957         mPendingWeakDerefs.push(refs);
958         break;
959 
960     case BR_ATTEMPT_ACQUIRE:
961         refs = (RefBase::weakref_type*)mIn.readInt32();
962         obj = (BBinder*)mIn.readInt32();
963 
964         {
965             const bool success = refs->attemptIncStrong(mProcess.get());
966             ALOG_ASSERT(success && refs->refBase() == obj,
967                        "BR_ATTEMPT_ACQUIRE: object %p does not match cookie %p (expected %p)",
968                        refs, obj, refs->refBase());
969 
970             mOut.writeInt32(BC_ACQUIRE_RESULT);
971             mOut.writeInt32((int32_t)success);
972         }
973         break;
974 
975     case BR_TRANSACTION:
976         {
977             binder_transaction_data tr;
978             result = mIn.read(&tr, sizeof(tr));
979             ALOG_ASSERT(result == NO_ERROR,
980                 "Not enough command data for brTRANSACTION");
981             if (result != NO_ERROR) break;
982 
983             Parcel buffer;
984             buffer.ipcSetDataReference(
985                 reinterpret_cast<const uint8_t*>(tr.data.ptr.buffer),
986                 tr.data_size,
987                 reinterpret_cast<const size_t*>(tr.data.ptr.offsets),
988                 tr.offsets_size/sizeof(size_t), freeBuffer, this);
989 
990             const pid_t origPid = mCallingPid;
991             const uid_t origUid = mCallingUid;
992 
993             mCallingPid = tr.sender_pid;
994             mCallingUid = tr.sender_euid;
995 
996             int curPrio = getpriority(PRIO_PROCESS, mMyThreadId);
997             if (gDisableBackgroundScheduling) {
998                 if (curPrio > ANDROID_PRIORITY_NORMAL) {
999                     // We have inherited a reduced priority from the caller, but do not
1000                     // want to run in that state in this process.  The driver set our
1001                     // priority already (though not our scheduling class), so bounce
1002                     // it back to the default before invoking the transaction.
1003                     setpriority(PRIO_PROCESS, mMyThreadId, ANDROID_PRIORITY_NORMAL);
1004                 }
1005             } else {
1006                 if (curPrio >= ANDROID_PRIORITY_BACKGROUND) {
1007                     // We want to use the inherited priority from the caller.
1008                     // Ensure this thread is in the background scheduling class,
1009                     // since the driver won't modify scheduling classes for us.
1010                     // The scheduling group is reset to default by the caller
1011                     // once this method returns after the transaction is complete.
1012                     set_sched_policy(mMyThreadId, SP_BACKGROUND);
1013                 }
1014             }
1015 
1016             //ALOGI(">>>> TRANSACT from pid %d uid %d\n", mCallingPid, mCallingUid);
1017 
1018             Parcel reply;
1019             IF_LOG_TRANSACTIONS() {
1020                 TextOutput::Bundle _b(alog);
1021                 alog << "BR_TRANSACTION thr " << (void*)pthread_self()
1022                     << " / obj " << tr.target.ptr << " / code "
1023                     << TypeCode(tr.code) << ": " << indent << buffer
1024                     << dedent << endl
1025                     << "Data addr = "
1026                     << reinterpret_cast<const uint8_t*>(tr.data.ptr.buffer)
1027                     << ", offsets addr="
1028                     << reinterpret_cast<const size_t*>(tr.data.ptr.offsets) << endl;
1029             }
1030             if (tr.target.ptr) {
1031                 sp<BBinder> b((BBinder*)tr.cookie);
1032                 const status_t error = b->transact(tr.code, buffer, &reply, tr.flags);
1033                 if (error < NO_ERROR) reply.setError(error);
1034 
1035             } else {
1036                 const status_t error = the_context_object->transact(tr.code, buffer, &reply, tr.flags);
1037                 if (error < NO_ERROR) reply.setError(error);
1038             }
1039 
1040             //ALOGI("<<<< TRANSACT from pid %d restore pid %d uid %d\n",
1041             //     mCallingPid, origPid, origUid);
1042 
1043             if ((tr.flags & TF_ONE_WAY) == 0) {
1044                 LOG_ONEWAY("Sending reply to %d!", mCallingPid);
1045                 sendReply(reply, 0);
1046             } else {
1047                 LOG_ONEWAY("NOT sending reply to %d!", mCallingPid);
1048             }
1049 
1050             mCallingPid = origPid;
1051             mCallingUid = origUid;
1052 
1053             IF_LOG_TRANSACTIONS() {
1054                 TextOutput::Bundle _b(alog);
1055                 alog << "BC_REPLY thr " << (void*)pthread_self() << " / obj "
1056                     << tr.target.ptr << ": " << indent << reply << dedent << endl;
1057             }
1058 
1059         }
1060         break;
1061 
1062     case BR_DEAD_BINDER:
1063         {
1064             BpBinder *proxy = (BpBinder*)mIn.readInt32();
1065             proxy->sendObituary();
1066             mOut.writeInt32(BC_DEAD_BINDER_DONE);
1067             mOut.writeInt32((int32_t)proxy);
1068         } break;
1069 
1070     case BR_CLEAR_DEATH_NOTIFICATION_DONE:
1071         {
1072             BpBinder *proxy = (BpBinder*)mIn.readInt32();
1073             proxy->getWeakRefs()->decWeak(proxy);
1074         } break;
1075 
1076     case BR_FINISHED:
1077         result = TIMED_OUT;
1078         break;
1079 
1080     case BR_NOOP:
1081         break;
1082 
1083     case BR_SPAWN_LOOPER:
1084         mProcess->spawnPooledThread(false);
1085         break;
1086 
1087     default:
1088         printf("*** BAD COMMAND %d received from Binder driver\n", cmd);
1089         result = UNKNOWN_ERROR;
1090         break;
1091     }
1092 
1093     if (result != NO_ERROR) {
1094         mLastError = result;
1095     }
1096 
1097     return result;
1098 }
1099 
threadDestructor(void * st)1100 void IPCThreadState::threadDestructor(void *st)
1101 {
1102 	IPCThreadState* const self = static_cast<IPCThreadState*>(st);
1103 	if (self) {
1104 		self->flushCommands();
1105 #if defined(HAVE_ANDROID_OS)
1106         if (self->mProcess->mDriverFD > 0) {
1107             ioctl(self->mProcess->mDriverFD, BINDER_THREAD_EXIT, 0);
1108         }
1109 #endif
1110 		delete self;
1111 	}
1112 }
1113 
1114 
freeBuffer(Parcel * parcel,const uint8_t * data,size_t dataSize,const size_t * objects,size_t objectsSize,void * cookie)1115 void IPCThreadState::freeBuffer(Parcel* parcel, const uint8_t* data, size_t dataSize,
1116                                 const size_t* objects, size_t objectsSize,
1117                                 void* cookie)
1118 {
1119     //ALOGI("Freeing parcel %p", &parcel);
1120     IF_LOG_COMMANDS() {
1121         alog << "Writing BC_FREE_BUFFER for " << data << endl;
1122     }
1123     ALOG_ASSERT(data != NULL, "Called with NULL data");
1124     if (parcel != NULL) parcel->closeFileDescriptors();
1125     IPCThreadState* state = self();
1126     state->mOut.writeInt32(BC_FREE_BUFFER);
1127     state->mOut.writeInt32((int32_t)data);
1128 }
1129 
1130 }; // namespace android
1131