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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 "BpBinder"
18 //#define LOG_NDEBUG 0
19 
20 #include <binder/BpBinder.h>
21 
22 #include <binder/IPCThreadState.h>
23 #include <binder/IResultReceiver.h>
24 #include <binder/RpcSession.h>
25 #include <binder/Stability.h>
26 #include <binder/Trace.h>
27 
28 #include <stdio.h>
29 
30 #include "BuildFlags.h"
31 #include "file.h"
32 
33 //#undef ALOGV
34 //#define ALOGV(...) fprintf(stderr, __VA_ARGS__)
35 
36 namespace android {
37 
38 using android::binder::unique_fd;
39 
40 // ---------------------------------------------------------------------------
41 
42 RpcMutex BpBinder::sTrackingLock;
43 std::unordered_map<int32_t, uint32_t> BpBinder::sTrackingMap;
44 std::unordered_map<int32_t, uint32_t> BpBinder::sLastLimitCallbackMap;
45 int BpBinder::sNumTrackedUids = 0;
46 std::atomic_bool BpBinder::sCountByUidEnabled(false);
47 binder_proxy_limit_callback BpBinder::sLimitCallback;
48 binder_proxy_warning_callback BpBinder::sWarningCallback;
49 bool BpBinder::sBinderProxyThrottleCreate = false;
50 
51 static StaticString16 kDescriptorUninit(u"");
52 
53 // Arbitrarily high value that probably distinguishes a bad behaving app
54 uint32_t BpBinder::sBinderProxyCountHighWatermark = 2500;
55 // Another arbitrary value a binder count needs to drop below before another callback will be called
56 uint32_t BpBinder::sBinderProxyCountLowWatermark = 2000;
57 // Arbitrary value between low and high watermark on a bad behaving app to
58 // trigger a warning callback.
59 uint32_t BpBinder::sBinderProxyCountWarningWatermark = 2250;
60 
61 std::atomic<uint32_t> BpBinder::sBinderProxyCount(0);
62 std::atomic<uint32_t> BpBinder::sBinderProxyCountWarned(0);
63 
64 static constexpr uint32_t kBinderProxyCountWarnInterval = 5000;
65 
66 // Log any transactions for which the data exceeds this size
67 #define LOG_TRANSACTIONS_OVER_SIZE (300 * 1024)
68 
69 enum {
70     LIMIT_REACHED_MASK = 0x80000000,        // A flag denoting that the limit has been reached
71     WARNING_REACHED_MASK = 0x40000000,      // A flag denoting that the warning has been reached
72     COUNTING_VALUE_MASK = 0x3FFFFFFF,       // A mask of the remaining bits for the count value
73 };
74 
ObjectManager()75 BpBinder::ObjectManager::ObjectManager()
76 {
77 }
78 
~ObjectManager()79 BpBinder::ObjectManager::~ObjectManager()
80 {
81     kill();
82 }
83 
attach(const void * objectID,void * object,void * cleanupCookie,IBinder::object_cleanup_func func)84 void* BpBinder::ObjectManager::attach(const void* objectID, void* object, void* cleanupCookie,
85                                       IBinder::object_cleanup_func func) {
86     entry_t e;
87     e.object = object;
88     e.cleanupCookie = cleanupCookie;
89     e.func = func;
90 
91     if (mObjects.find(objectID) != mObjects.end()) {
92         ALOGI("Trying to attach object ID %p to binder ObjectManager %p with object %p, but object "
93               "ID already in use",
94               objectID, this, object);
95         return mObjects[objectID].object;
96     }
97 
98     mObjects.insert({objectID, e});
99     return nullptr;
100 }
101 
find(const void * objectID) const102 void* BpBinder::ObjectManager::find(const void* objectID) const
103 {
104     auto i = mObjects.find(objectID);
105     if (i == mObjects.end()) return nullptr;
106     return i->second.object;
107 }
108 
detach(const void * objectID)109 void* BpBinder::ObjectManager::detach(const void* objectID) {
110     auto i = mObjects.find(objectID);
111     if (i == mObjects.end()) return nullptr;
112     void* value = i->second.object;
113     mObjects.erase(i);
114     return value;
115 }
116 
117 namespace {
118 struct Tag {
119     wp<IBinder> binder;
120 };
121 } // namespace
122 
cleanWeak(const void *,void * obj,void *)123 static void cleanWeak(const void* /* id */, void* obj, void* /* cookie */) {
124     delete static_cast<Tag*>(obj);
125 }
126 
lookupOrCreateWeak(const void * objectID,object_make_func make,const void * makeArgs)127 sp<IBinder> BpBinder::ObjectManager::lookupOrCreateWeak(const void* objectID, object_make_func make,
128                                                         const void* makeArgs) {
129     entry_t& e = mObjects[objectID];
130     if (e.object != nullptr) {
131         if (auto attached = static_cast<Tag*>(e.object)->binder.promote()) {
132             return attached;
133         }
134     } else {
135         e.object = new Tag;
136         LOG_ALWAYS_FATAL_IF(!e.object, "no more memory");
137     }
138     sp<IBinder> newObj = make(makeArgs);
139 
140     static_cast<Tag*>(e.object)->binder = newObj;
141     e.cleanupCookie = nullptr;
142     e.func = cleanWeak;
143 
144     return newObj;
145 }
146 
kill()147 void BpBinder::ObjectManager::kill()
148 {
149     const size_t N = mObjects.size();
150     ALOGV("Killing %zu objects in manager %p", N, this);
151     for (auto i : mObjects) {
152         const entry_t& e = i.second;
153         if (e.func != nullptr) {
154             e.func(i.first, e.object, e.cleanupCookie);
155         }
156     }
157 
158     mObjects.clear();
159 }
160 
161 // ---------------------------------------------------------------------------
162 
create(int32_t handle)163 sp<BpBinder> BpBinder::create(int32_t handle) {
164     if constexpr (!kEnableKernelIpc) {
165         LOG_ALWAYS_FATAL("Binder kernel driver disabled at build time");
166         return nullptr;
167     }
168 
169     int32_t trackedUid = -1;
170     if (sCountByUidEnabled) {
171         trackedUid = IPCThreadState::self()->getCallingUid();
172         RpcMutexUniqueLock _l(sTrackingLock);
173         uint32_t trackedValue = sTrackingMap[trackedUid];
174         if (trackedValue & LIMIT_REACHED_MASK) [[unlikely]] {
175             if (sBinderProxyThrottleCreate) {
176                 return nullptr;
177             }
178             trackedValue = trackedValue & COUNTING_VALUE_MASK;
179             uint32_t lastLimitCallbackAt = sLastLimitCallbackMap[trackedUid];
180 
181             if (trackedValue > lastLimitCallbackAt &&
182                 (trackedValue - lastLimitCallbackAt > sBinderProxyCountHighWatermark)) {
183                 ALOGE("Still too many binder proxy objects sent to uid %d from uid %d (%d proxies "
184                       "held)",
185                       getuid(), trackedUid, trackedValue);
186                 if (sLimitCallback) sLimitCallback(trackedUid);
187                 sLastLimitCallbackMap[trackedUid] = trackedValue;
188             }
189         } else {
190             uint32_t currentValue = trackedValue & COUNTING_VALUE_MASK;
191             if (currentValue >= sBinderProxyCountWarningWatermark
192                     && currentValue < sBinderProxyCountHighWatermark
193                     && ((trackedValue & WARNING_REACHED_MASK) == 0)) [[unlikely]] {
194                 sTrackingMap[trackedUid] |= WARNING_REACHED_MASK;
195                 if (sWarningCallback) sWarningCallback(trackedUid);
196             } else if (currentValue >= sBinderProxyCountHighWatermark) {
197                 ALOGE("Too many binder proxy objects sent to uid %d from uid %d (%d proxies held)",
198                       getuid(), trackedUid, trackedValue);
199                 sTrackingMap[trackedUid] |= LIMIT_REACHED_MASK;
200                 if (sLimitCallback) sLimitCallback(trackedUid);
201                 sLastLimitCallbackMap[trackedUid] = trackedValue & COUNTING_VALUE_MASK;
202                 if (sBinderProxyThrottleCreate) {
203                     ALOGI("Throttling binder proxy creates from uid %d in uid %d until binder proxy"
204                           " count drops below %d",
205                           trackedUid, getuid(), sBinderProxyCountLowWatermark);
206                     return nullptr;
207                 }
208             }
209         }
210         sTrackingMap[trackedUid]++;
211     }
212     uint32_t numProxies = sBinderProxyCount.fetch_add(1, std::memory_order_relaxed);
213     binder::os::trace_int(ATRACE_TAG_AIDL, "binder_proxies", numProxies);
214     uint32_t numLastWarned = sBinderProxyCountWarned.load(std::memory_order_relaxed);
215     uint32_t numNextWarn = numLastWarned + kBinderProxyCountWarnInterval;
216     if (numProxies >= numNextWarn) {
217         // Multiple threads can get here, make sure only one of them gets to
218         // update the warn counter.
219         if (sBinderProxyCountWarned.compare_exchange_strong(numLastWarned,
220                                                             numNextWarn,
221                                                             std::memory_order_relaxed)) {
222             ALOGW("Unexpectedly many live BinderProxies: %d\n", numProxies);
223         }
224     }
225     return sp<BpBinder>::make(BinderHandle{handle}, trackedUid);
226 }
227 
create(const sp<RpcSession> & session,uint64_t address)228 sp<BpBinder> BpBinder::create(const sp<RpcSession>& session, uint64_t address) {
229     LOG_ALWAYS_FATAL_IF(session == nullptr, "BpBinder::create null session");
230 
231     // These are not currently tracked, since there is no UID or other
232     // identifier to track them with. However, if similar functionality is
233     // needed, session objects keep track of all BpBinder objects on a
234     // per-session basis.
235 
236     return sp<BpBinder>::make(RpcHandle{session, address});
237 }
238 
BpBinder(Handle && handle)239 BpBinder::BpBinder(Handle&& handle)
240       : mStability(0),
241         mHandle(handle),
242         mAlive(true),
243         mObitsSent(false),
244         mObituaries(nullptr),
245         mDescriptorCache(kDescriptorUninit),
246         mTrackedUid(-1) {
247     extendObjectLifetime(OBJECT_LIFETIME_WEAK);
248 }
249 
BpBinder(BinderHandle && handle,int32_t trackedUid)250 BpBinder::BpBinder(BinderHandle&& handle, int32_t trackedUid) : BpBinder(Handle(handle)) {
251     if constexpr (!kEnableKernelIpc) {
252         LOG_ALWAYS_FATAL("Binder kernel driver disabled at build time");
253         return;
254     }
255 
256     mTrackedUid = trackedUid;
257 
258     ALOGV("Creating BpBinder %p handle %d\n", this, this->binderHandle());
259 
260     IPCThreadState::self()->incWeakHandle(this->binderHandle(), this);
261 }
262 
BpBinder(RpcHandle && handle)263 BpBinder::BpBinder(RpcHandle&& handle) : BpBinder(Handle(handle)) {
264     LOG_ALWAYS_FATAL_IF(rpcSession() == nullptr, "BpBinder created w/o session object");
265 }
266 
isRpcBinder() const267 bool BpBinder::isRpcBinder() const {
268     return std::holds_alternative<RpcHandle>(mHandle);
269 }
270 
rpcAddress() const271 uint64_t BpBinder::rpcAddress() const {
272     return std::get<RpcHandle>(mHandle).address;
273 }
274 
rpcSession() const275 const sp<RpcSession>& BpBinder::rpcSession() const {
276     return std::get<RpcHandle>(mHandle).session;
277 }
278 
binderHandle() const279 int32_t BpBinder::binderHandle() const {
280     return std::get<BinderHandle>(mHandle).handle;
281 }
282 
getDebugBinderHandle() const283 std::optional<int32_t> BpBinder::getDebugBinderHandle() const {
284     if (!isRpcBinder()) {
285         return binderHandle();
286     } else {
287         return std::nullopt;
288     }
289 }
290 
isDescriptorCached() const291 bool BpBinder::isDescriptorCached() const {
292     RpcMutexUniqueLock _l(mLock);
293     return mDescriptorCache.c_str() != kDescriptorUninit.c_str();
294 }
295 
getInterfaceDescriptor() const296 const String16& BpBinder::getInterfaceDescriptor() const
297 {
298     if (!isDescriptorCached()) {
299         sp<BpBinder> thiz = sp<BpBinder>::fromExisting(const_cast<BpBinder*>(this));
300 
301         Parcel data;
302         data.markForBinder(thiz);
303         Parcel reply;
304         // do the IPC without a lock held.
305         status_t err = thiz->transact(INTERFACE_TRANSACTION, data, &reply);
306         if (err == NO_ERROR) {
307             String16 res(reply.readString16());
308             RpcMutexUniqueLock _l(mLock);
309             // mDescriptorCache could have been assigned while the lock was
310             // released.
311             if (mDescriptorCache.c_str() == kDescriptorUninit.c_str()) mDescriptorCache = res;
312         }
313     }
314 
315     // we're returning a reference to a non-static object here. Usually this
316     // is not something smart to do, however, with binder objects it is
317     // (usually) safe because they are reference-counted.
318 
319     return mDescriptorCache;
320 }
321 
isBinderAlive() const322 bool BpBinder::isBinderAlive() const
323 {
324     return mAlive != 0;
325 }
326 
pingBinder()327 status_t BpBinder::pingBinder()
328 {
329     Parcel data;
330     data.markForBinder(sp<BpBinder>::fromExisting(this));
331     Parcel reply;
332     return transact(PING_TRANSACTION, data, &reply);
333 }
334 
startRecordingBinder(const unique_fd & fd)335 status_t BpBinder::startRecordingBinder(const unique_fd& fd) {
336     Parcel send, reply;
337     send.writeUniqueFileDescriptor(fd);
338     return transact(START_RECORDING_TRANSACTION, send, &reply);
339 }
340 
stopRecordingBinder()341 status_t BpBinder::stopRecordingBinder() {
342     Parcel data, reply;
343     data.markForBinder(sp<BpBinder>::fromExisting(this));
344     return transact(STOP_RECORDING_TRANSACTION, data, &reply);
345 }
346 
dump(int fd,const Vector<String16> & args)347 status_t BpBinder::dump(int fd, const Vector<String16>& args)
348 {
349     Parcel send;
350     Parcel reply;
351     send.writeFileDescriptor(fd);
352     const size_t numArgs = args.size();
353     send.writeInt32(numArgs);
354     for (size_t i = 0; i < numArgs; i++) {
355         send.writeString16(args[i]);
356     }
357     status_t err = transact(DUMP_TRANSACTION, send, &reply);
358     return err;
359 }
360 
361 // NOLINTNEXTLINE(google-default-arguments)
transact(uint32_t code,const Parcel & data,Parcel * reply,uint32_t flags)362 status_t BpBinder::transact(
363     uint32_t code, const Parcel& data, Parcel* reply, uint32_t flags)
364 {
365     // Once a binder has died, it will never come back to life.
366     if (mAlive) {
367         bool privateVendor = flags & FLAG_PRIVATE_VENDOR;
368         // don't send userspace flags to the kernel
369         flags = flags & ~static_cast<uint32_t>(FLAG_PRIVATE_VENDOR);
370 
371         // user transactions require a given stability level
372         if (code >= FIRST_CALL_TRANSACTION && code <= LAST_CALL_TRANSACTION) {
373             using android::internal::Stability;
374 
375             int16_t stability = Stability::getRepr(this);
376             Stability::Level required = privateVendor ? Stability::VENDOR
377                 : Stability::getLocalLevel();
378 
379             if (!Stability::check(stability, required)) [[unlikely]] {
380                 ALOGE("Cannot do a user transaction on a %s binder (%s) in a %s context.",
381                       Stability::levelString(stability).c_str(),
382                       String8(getInterfaceDescriptor()).c_str(),
383                       Stability::levelString(required).c_str());
384                 return BAD_TYPE;
385             }
386         }
387 
388         status_t status;
389         if (isRpcBinder()) [[unlikely]] {
390             status = rpcSession()->transact(sp<IBinder>::fromExisting(this), code, data, reply,
391                                             flags);
392         } else {
393             if constexpr (!kEnableKernelIpc) {
394                 LOG_ALWAYS_FATAL("Binder kernel driver disabled at build time");
395                 return INVALID_OPERATION;
396             }
397 
398             status = IPCThreadState::self()->transact(binderHandle(), code, data, reply, flags);
399         }
400         if (data.dataSize() > LOG_TRANSACTIONS_OVER_SIZE) {
401             RpcMutexUniqueLock _l(mLock);
402             ALOGW("Large outgoing transaction of %zu bytes, interface descriptor %s, code %d",
403                   data.dataSize(), String8(mDescriptorCache).c_str(), code);
404         }
405 
406         if (status == DEAD_OBJECT) mAlive = 0;
407 
408         return status;
409     }
410 
411     return DEAD_OBJECT;
412 }
413 
414 // NOLINTNEXTLINE(google-default-arguments)
linkToDeath(const sp<DeathRecipient> & recipient,void * cookie,uint32_t flags)415 status_t BpBinder::linkToDeath(
416     const sp<DeathRecipient>& recipient, void* cookie, uint32_t flags)
417 {
418     if (isRpcBinder()) {
419         if (rpcSession()->getMaxIncomingThreads() < 1) {
420             ALOGE("Cannot register a DeathRecipient without any incoming threads. Need to set max "
421                   "incoming threads to a value greater than 0 before calling linkToDeath.");
422             return INVALID_OPERATION;
423         }
424     } else if constexpr (!kEnableKernelIpc) {
425         LOG_ALWAYS_FATAL("Binder kernel driver disabled at build time");
426         return INVALID_OPERATION;
427     } else {
428         if (ProcessState::self()->getThreadPoolMaxTotalThreadCount() == 0) {
429             ALOGW("Linking to death on %s but there are no threads (yet?) listening to incoming "
430                   "transactions. See ProcessState::startThreadPool and "
431                   "ProcessState::setThreadPoolMaxThreadCount. Generally you should setup the "
432                   "binder "
433                   "threadpool before other initialization steps.",
434                   String8(getInterfaceDescriptor()).c_str());
435         }
436     }
437 
438     Obituary ob;
439     ob.recipient = recipient;
440     ob.cookie = cookie;
441     ob.flags = flags;
442 
443     LOG_ALWAYS_FATAL_IF(recipient == nullptr,
444                         "linkToDeath(): recipient must be non-NULL");
445 
446     {
447         RpcMutexUniqueLock _l(mLock);
448 
449         if (!mObitsSent) {
450             if (!mObituaries) {
451                 mObituaries = new Vector<Obituary>;
452                 if (!mObituaries) {
453                     return NO_MEMORY;
454                 }
455                 ALOGV("Requesting death notification: %p handle %d\n", this, binderHandle());
456                 if (!isRpcBinder()) {
457                     if constexpr (kEnableKernelIpc) {
458                         getWeakRefs()->incWeak(this);
459                         IPCThreadState* self = IPCThreadState::self();
460                         self->requestDeathNotification(binderHandle(), this);
461                         self->flushCommands();
462                     }
463                 }
464             }
465             ssize_t res = mObituaries->add(ob);
466             return res >= (ssize_t)NO_ERROR ? (status_t)NO_ERROR : res;
467         }
468     }
469 
470     return DEAD_OBJECT;
471 }
472 
473 // NOLINTNEXTLINE(google-default-arguments)
unlinkToDeath(const wp<DeathRecipient> & recipient,void * cookie,uint32_t flags,wp<DeathRecipient> * outRecipient)474 status_t BpBinder::unlinkToDeath(
475     const wp<DeathRecipient>& recipient, void* cookie, uint32_t flags,
476     wp<DeathRecipient>* outRecipient)
477 {
478     if (!kEnableKernelIpc && !isRpcBinder()) {
479         LOG_ALWAYS_FATAL("Binder kernel driver disabled at build time");
480         return INVALID_OPERATION;
481     }
482 
483     RpcMutexUniqueLock _l(mLock);
484 
485     if (mObitsSent) {
486         return DEAD_OBJECT;
487     }
488 
489     const size_t N = mObituaries ? mObituaries->size() : 0;
490     for (size_t i=0; i<N; i++) {
491         const Obituary& obit = mObituaries->itemAt(i);
492         if ((obit.recipient == recipient
493                     || (recipient == nullptr && obit.cookie == cookie))
494                 && obit.flags == flags) {
495             if (outRecipient != nullptr) {
496                 *outRecipient = mObituaries->itemAt(i).recipient;
497             }
498             mObituaries->removeAt(i);
499             if (mObituaries->size() == 0) {
500                 ALOGV("Clearing death notification: %p handle %d\n", this, binderHandle());
501                 if (!isRpcBinder()) {
502                     if constexpr (kEnableKernelIpc) {
503                         IPCThreadState* self = IPCThreadState::self();
504                         self->clearDeathNotification(binderHandle(), this);
505                         self->flushCommands();
506                     }
507                 }
508                 delete mObituaries;
509                 mObituaries = nullptr;
510             }
511             return NO_ERROR;
512         }
513     }
514 
515     return NAME_NOT_FOUND;
516 }
517 
sendObituary()518 void BpBinder::sendObituary()
519 {
520     if (!kEnableKernelIpc && !isRpcBinder()) {
521         LOG_ALWAYS_FATAL("Binder kernel driver disabled at build time");
522         return;
523     }
524 
525     ALOGV("Sending obituary for proxy %p handle %d, mObitsSent=%s\n", this, binderHandle(),
526           mObitsSent ? "true" : "false");
527 
528     mAlive = 0;
529     if (mObitsSent) return;
530 
531     mLock.lock();
532     Vector<Obituary>* obits = mObituaries;
533     if(obits != nullptr) {
534         ALOGV("Clearing sent death notification: %p handle %d\n", this, binderHandle());
535         if (!isRpcBinder()) {
536             if constexpr (kEnableKernelIpc) {
537                 IPCThreadState* self = IPCThreadState::self();
538                 self->clearDeathNotification(binderHandle(), this);
539                 self->flushCommands();
540             }
541         }
542         mObituaries = nullptr;
543     }
544     mObitsSent = 1;
545     mLock.unlock();
546 
547     ALOGV("Reporting death of proxy %p for %zu recipients\n",
548         this, obits ? obits->size() : 0U);
549 
550     if (obits != nullptr) {
551         const size_t N = obits->size();
552         for (size_t i=0; i<N; i++) {
553             reportOneDeath(obits->itemAt(i));
554         }
555 
556         delete obits;
557     }
558 }
559 
reportOneDeath(const Obituary & obit)560 void BpBinder::reportOneDeath(const Obituary& obit)
561 {
562     sp<DeathRecipient> recipient = obit.recipient.promote();
563     ALOGV("Reporting death to recipient: %p\n", recipient.get());
564     if (recipient == nullptr) return;
565 
566     recipient->binderDied(wp<BpBinder>::fromExisting(this));
567 }
568 
attachObject(const void * objectID,void * object,void * cleanupCookie,object_cleanup_func func)569 void* BpBinder::attachObject(const void* objectID, void* object, void* cleanupCookie,
570                              object_cleanup_func func) {
571     RpcMutexUniqueLock _l(mLock);
572     ALOGV("Attaching object %p to binder %p (manager=%p)", object, this, &mObjects);
573     return mObjects.attach(objectID, object, cleanupCookie, func);
574 }
575 
findObject(const void * objectID) const576 void* BpBinder::findObject(const void* objectID) const
577 {
578     RpcMutexUniqueLock _l(mLock);
579     return mObjects.find(objectID);
580 }
581 
detachObject(const void * objectID)582 void* BpBinder::detachObject(const void* objectID) {
583     RpcMutexUniqueLock _l(mLock);
584     return mObjects.detach(objectID);
585 }
586 
withLock(const std::function<void ()> & doWithLock)587 void BpBinder::withLock(const std::function<void()>& doWithLock) {
588     RpcMutexUniqueLock _l(mLock);
589     doWithLock();
590 }
591 
lookupOrCreateWeak(const void * objectID,object_make_func make,const void * makeArgs)592 sp<IBinder> BpBinder::lookupOrCreateWeak(const void* objectID, object_make_func make,
593                                          const void* makeArgs) {
594     RpcMutexUniqueLock _l(mLock);
595     return mObjects.lookupOrCreateWeak(objectID, make, makeArgs);
596 }
597 
remoteBinder()598 BpBinder* BpBinder::remoteBinder()
599 {
600     return this;
601 }
602 
~BpBinder()603 BpBinder::~BpBinder() {
604     if (isRpcBinder()) [[unlikely]] {
605         return;
606     }
607 
608     if constexpr (!kEnableKernelIpc) {
609         LOG_ALWAYS_FATAL("Binder kernel driver disabled at build time");
610         return;
611     }
612 
613     ALOGV("Destroying BpBinder %p handle %d\n", this, binderHandle());
614 
615     IPCThreadState* ipc = IPCThreadState::self();
616 
617     if (mTrackedUid >= 0) {
618         RpcMutexUniqueLock _l(sTrackingLock);
619         uint32_t trackedValue = sTrackingMap[mTrackedUid];
620         if ((trackedValue & COUNTING_VALUE_MASK) == 0) [[unlikely]] {
621             ALOGE("Unexpected Binder Proxy tracking decrement in %p handle %d\n", this,
622                   binderHandle());
623         } else {
624             auto countingValue = trackedValue & COUNTING_VALUE_MASK;
625             if ((trackedValue & (LIMIT_REACHED_MASK | WARNING_REACHED_MASK)) &&
626                 (countingValue <= sBinderProxyCountLowWatermark)) [[unlikely]] {
627                 ALOGI("Limit reached bit reset for uid %d (fewer than %d proxies from uid %d held)",
628                       getuid(), sBinderProxyCountLowWatermark, mTrackedUid);
629                 sTrackingMap[mTrackedUid] &= ~(LIMIT_REACHED_MASK | WARNING_REACHED_MASK);
630                 sLastLimitCallbackMap.erase(mTrackedUid);
631             }
632             if (--sTrackingMap[mTrackedUid] == 0) {
633                 sTrackingMap.erase(mTrackedUid);
634             }
635         }
636     }
637     uint32_t numProxies = --sBinderProxyCount;
638     binder::os::trace_int(ATRACE_TAG_AIDL, "binder_proxies", numProxies);
639     if (ipc) {
640         ipc->expungeHandle(binderHandle(), this);
641         ipc->decWeakHandle(binderHandle());
642     }
643 }
644 
onFirstRef()645 void BpBinder::onFirstRef() {
646     if (isRpcBinder()) [[unlikely]] {
647         return;
648     }
649 
650     if constexpr (!kEnableKernelIpc) {
651         LOG_ALWAYS_FATAL("Binder kernel driver disabled at build time");
652         return;
653     }
654 
655     ALOGV("onFirstRef BpBinder %p handle %d\n", this, binderHandle());
656     IPCThreadState* ipc = IPCThreadState::self();
657     if (ipc) ipc->incStrongHandle(binderHandle(), this);
658 }
659 
onLastStrongRef(const void *)660 void BpBinder::onLastStrongRef(const void* /*id*/) {
661     if (isRpcBinder()) [[unlikely]] {
662         (void)rpcSession()->sendDecStrong(this);
663         return;
664     }
665 
666     if constexpr (!kEnableKernelIpc) {
667         LOG_ALWAYS_FATAL("Binder kernel driver disabled at build time");
668         return;
669     }
670 
671     ALOGV("onLastStrongRef BpBinder %p handle %d\n", this, binderHandle());
672     IF_ALOGV() {
673         printRefs();
674     }
675     IPCThreadState* ipc = IPCThreadState::self();
676     if (ipc) ipc->decStrongHandle(binderHandle());
677 
678     mLock.lock();
679     Vector<Obituary>* obits = mObituaries;
680     if(obits != nullptr) {
681         if (!obits->isEmpty()) {
682             ALOGI("onLastStrongRef automatically unlinking death recipients: %s",
683                   String8(mDescriptorCache).c_str());
684         }
685 
686         if (ipc) ipc->clearDeathNotification(binderHandle(), this);
687         mObituaries = nullptr;
688     }
689     mLock.unlock();
690 
691     if (obits != nullptr) {
692         // XXX Should we tell any remaining DeathRecipient
693         // objects that the last strong ref has gone away, so they
694         // are no longer linked?
695         delete obits;
696     }
697 }
698 
onIncStrongAttempted(uint32_t,const void *)699 bool BpBinder::onIncStrongAttempted(uint32_t /*flags*/, const void* /*id*/)
700 {
701     // RPC binder doesn't currently support inc from weak binders
702     if (isRpcBinder()) [[unlikely]] {
703         return false;
704     }
705 
706     if constexpr (!kEnableKernelIpc) {
707         LOG_ALWAYS_FATAL("Binder kernel driver disabled at build time");
708         return false;
709     }
710 
711     ALOGV("onIncStrongAttempted BpBinder %p handle %d\n", this, binderHandle());
712     IPCThreadState* ipc = IPCThreadState::self();
713     return ipc ? ipc->attemptIncStrongHandle(binderHandle()) == NO_ERROR : false;
714 }
715 
getBinderProxyCount(uint32_t uid)716 uint32_t BpBinder::getBinderProxyCount(uint32_t uid)
717 {
718     RpcMutexUniqueLock _l(sTrackingLock);
719     auto it = sTrackingMap.find(uid);
720     if (it != sTrackingMap.end()) {
721         return it->second & COUNTING_VALUE_MASK;
722     }
723     return 0;
724 }
725 
getBinderProxyCount()726 uint32_t BpBinder::getBinderProxyCount()
727 {
728     return sBinderProxyCount.load();
729 }
730 
getCountByUid(Vector<uint32_t> & uids,Vector<uint32_t> & counts)731 void BpBinder::getCountByUid(Vector<uint32_t>& uids, Vector<uint32_t>& counts)
732 {
733     RpcMutexUniqueLock _l(sTrackingLock);
734     uids.setCapacity(sTrackingMap.size());
735     counts.setCapacity(sTrackingMap.size());
736     for (const auto& it : sTrackingMap) {
737         uids.push_back(it.first);
738         counts.push_back(it.second & COUNTING_VALUE_MASK);
739     }
740 }
741 
enableCountByUid()742 void BpBinder::enableCountByUid() { sCountByUidEnabled.store(true); }
disableCountByUid()743 void BpBinder::disableCountByUid() { sCountByUidEnabled.store(false); }
setCountByUidEnabled(bool enable)744 void BpBinder::setCountByUidEnabled(bool enable) { sCountByUidEnabled.store(enable); }
745 
setBinderProxyCountEventCallback(binder_proxy_limit_callback cbl,binder_proxy_warning_callback cbw)746 void BpBinder::setBinderProxyCountEventCallback(binder_proxy_limit_callback cbl,
747                                                 binder_proxy_warning_callback cbw) {
748     RpcMutexUniqueLock _l(sTrackingLock);
749     sLimitCallback = std::move(cbl);
750     sWarningCallback = std::move(cbw);
751 }
752 
setBinderProxyCountWatermarks(int high,int low,int warning)753 void BpBinder::setBinderProxyCountWatermarks(int high, int low, int warning) {
754     RpcMutexUniqueLock _l(sTrackingLock);
755     sBinderProxyCountHighWatermark = high;
756     sBinderProxyCountLowWatermark = low;
757     sBinderProxyCountWarningWatermark = warning;
758 }
759 
760 // ---------------------------------------------------------------------------
761 
762 } // namespace android
763