Native.cpp revision ff7ff110d17428732a97c37bf31f7f49d194f638
1/* 2 * Copyright (C) 2008 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/* 18 * Native method resolution. 19 * 20 * Currently the "Dalvik native" methods are only used for internal methods. 21 * Someday we may want to export the interface as a faster but riskier 22 * alternative to JNI. 23 */ 24#include "Dalvik.h" 25 26#include <stdlib.h> 27#include <dlfcn.h> 28 29static void freeSharedLibEntry(void* ptr); 30static void* lookupSharedLibMethod(const Method* method); 31 32 33/* 34 * Initialize the native code loader. 35 */ 36bool dvmNativeStartup() 37{ 38 gDvm.nativeLibs = dvmHashTableCreate(4, freeSharedLibEntry); 39 if (gDvm.nativeLibs == NULL) 40 return false; 41 42 return true; 43} 44 45/* 46 * Free up our tables. 47 */ 48void dvmNativeShutdown() 49{ 50 dvmHashTableFree(gDvm.nativeLibs); 51 gDvm.nativeLibs = NULL; 52} 53 54 55/* 56 * Resolve a native method and invoke it. 57 * 58 * This is executed as if it were a native bridge or function. If the 59 * resolution succeeds, method->insns is replaced, and we don't go through 60 * here again unless the method is unregistered. 61 * 62 * Initializes method's class if necessary. 63 * 64 * An exception is thrown on resolution failure. 65 * 66 * (This should not be taking "const Method*", because it modifies the 67 * structure, but the declaration needs to match the DalvikBridgeFunc 68 * type definition.) 69 */ 70void dvmResolveNativeMethod(const u4* args, JValue* pResult, 71 const Method* method, Thread* self) 72{ 73 ClassObject* clazz = method->clazz; 74 75 /* 76 * If this is a static method, it could be called before the class 77 * has been initialized. 78 */ 79 if (dvmIsStaticMethod(method)) { 80 if (!dvmIsClassInitialized(clazz) && !dvmInitClass(clazz)) { 81 assert(dvmCheckException(dvmThreadSelf())); 82 return; 83 } 84 } else { 85 assert(dvmIsClassInitialized(clazz) || 86 dvmIsClassInitializing(clazz)); 87 } 88 89 /* start with our internal-native methods */ 90 DalvikNativeFunc infunc = dvmLookupInternalNativeMethod(method); 91 if (infunc != NULL) { 92 /* resolution always gets the same answer, so no race here */ 93 IF_LOGVV() { 94 char* desc = dexProtoCopyMethodDescriptor(&method->prototype); 95 LOGVV("+++ resolved native %s.%s %s, invoking", 96 clazz->descriptor, method->name, desc); 97 free(desc); 98 } 99 if (dvmIsSynchronizedMethod(method)) { 100 ALOGE("ERROR: internal-native can't be declared 'synchronized'"); 101 ALOGE("Failing on %s.%s", method->clazz->descriptor, method->name); 102 dvmAbort(); // harsh, but this is VM-internal problem 103 } 104 DalvikBridgeFunc dfunc = (DalvikBridgeFunc) infunc; 105 dvmSetNativeFunc((Method*) method, dfunc, NULL); 106 dfunc(args, pResult, method, self); 107 return; 108 } 109 110 /* now scan any DLLs we have loaded for JNI signatures */ 111 void* func = lookupSharedLibMethod(method); 112 if (func != NULL) { 113 /* found it, point it at the JNI bridge and then call it */ 114 dvmUseJNIBridge((Method*) method, func); 115 (*method->nativeFunc)(args, pResult, method, self); 116 return; 117 } 118 119 IF_ALOGW() { 120 char* desc = dexProtoCopyMethodDescriptor(&method->prototype); 121 ALOGW("No implementation found for native %s.%s:%s", 122 clazz->descriptor, method->name, desc); 123 free(desc); 124 } 125 126 dvmThrowUnsatisfiedLinkError("Native method not found", method); 127} 128 129 130/* 131 * =========================================================================== 132 * Native shared library support 133 * =========================================================================== 134 */ 135 136// TODO? if a ClassLoader is unloaded, we need to unload all DLLs that 137// are associated with it. (Or not -- can't determine if native code 138// is still using parts of it.) 139 140enum OnLoadState { 141 kOnLoadPending = 0, /* initial state, must be zero */ 142 kOnLoadFailed, 143 kOnLoadOkay, 144}; 145 146/* 147 * We add one of these to the hash table for every library we load. The 148 * hash is on the "pathName" field. 149 */ 150struct SharedLib { 151 char* pathName; /* absolute path to library */ 152 void* handle; /* from dlopen */ 153 Object* classLoader; /* ClassLoader we are associated with */ 154 155 pthread_mutex_t onLoadLock; /* guards remaining items */ 156 pthread_cond_t onLoadCond; /* wait for JNI_OnLoad in other thread */ 157 u4 onLoadThreadId; /* recursive invocation guard */ 158 OnLoadState onLoadResult; /* result of earlier JNI_OnLoad */ 159}; 160 161/* 162 * (This is a dvmHashTableLookup callback.) 163 * 164 * Find an entry that matches the string. 165 */ 166static int hashcmpNameStr(const void* ventry, const void* vname) 167{ 168 const SharedLib* pLib = (const SharedLib*) ventry; 169 const char* name = (const char*) vname; 170 171 return strcmp(pLib->pathName, name); 172} 173 174/* 175 * (This is a dvmHashTableLookup callback.) 176 * 177 * Find an entry that matches the new entry. 178 * 179 * We don't compare the class loader here, because you're not allowed to 180 * have the same shared library associated with more than one CL. 181 */ 182static int hashcmpSharedLib(const void* ventry, const void* vnewEntry) 183{ 184 const SharedLib* pLib = (const SharedLib*) ventry; 185 const SharedLib* pNewLib = (const SharedLib*) vnewEntry; 186 187 ALOGD("--- comparing %p '%s' %p '%s'", 188 pLib, pLib->pathName, pNewLib, pNewLib->pathName); 189 return strcmp(pLib->pathName, pNewLib->pathName); 190} 191 192/* 193 * Check to see if an entry with the same pathname already exists. 194 */ 195static SharedLib* findSharedLibEntry(const char* pathName) 196{ 197 u4 hash = dvmComputeUtf8Hash(pathName); 198 void* ent; 199 200 ent = dvmHashTableLookup(gDvm.nativeLibs, hash, (void*)pathName, 201 hashcmpNameStr, false); 202 return (SharedLib*)ent; 203} 204 205/* 206 * Add the new entry to the table. 207 * 208 * Returns the table entry, which will not be the same as "pLib" if the 209 * entry already exists. 210 */ 211static SharedLib* addSharedLibEntry(SharedLib* pLib) 212{ 213 u4 hash = dvmComputeUtf8Hash(pLib->pathName); 214 215 /* 216 * Do the lookup with the "add" flag set. If we add it, we will get 217 * our own pointer back. If somebody beat us to the punch, we'll get 218 * their pointer back instead. 219 */ 220 return (SharedLib*)dvmHashTableLookup(gDvm.nativeLibs, hash, pLib, 221 hashcmpSharedLib, true); 222} 223 224/* 225 * Free up an entry. (This is a dvmHashTableFree callback.) 226 */ 227static void freeSharedLibEntry(void* ptr) 228{ 229 SharedLib* pLib = (SharedLib*) ptr; 230 231 /* 232 * Calling dlclose() here is somewhat dangerous, because it's possible 233 * that a thread outside the VM is still accessing the code we loaded. 234 */ 235 if (false) 236 dlclose(pLib->handle); 237 free(pLib->pathName); 238 free(pLib); 239} 240 241/* 242 * Convert library name to system-dependent form, e.g. "jpeg" becomes 243 * "libjpeg.so". 244 * 245 * (Should we have this take buffer+len and avoid the alloc? It gets 246 * called very rarely.) 247 */ 248char* dvmCreateSystemLibraryName(char* libName) 249{ 250 char buf[256]; 251 int len; 252 253 len = snprintf(buf, sizeof(buf), OS_SHARED_LIB_FORMAT_STR, libName); 254 if (len >= (int) sizeof(buf)) 255 return NULL; 256 else 257 return strdup(buf); 258} 259 260/* 261 * Check the result of an earlier call to JNI_OnLoad on this library. If 262 * the call has not yet finished in another thread, wait for it. 263 */ 264static bool checkOnLoadResult(SharedLib* pEntry) 265{ 266 Thread* self = dvmThreadSelf(); 267 if (pEntry->onLoadThreadId == self->threadId) { 268 /* 269 * Check this so we don't end up waiting for ourselves. We need 270 * to return "true" so the caller can continue. 271 */ 272 ALOGI("threadid=%d: recursive native library load attempt (%s)", 273 self->threadId, pEntry->pathName); 274 return true; 275 } 276 277 ALOGV("+++ retrieving %s OnLoad status", pEntry->pathName); 278 bool result; 279 280 dvmLockMutex(&pEntry->onLoadLock); 281 while (pEntry->onLoadResult == kOnLoadPending) { 282 ALOGD("threadid=%d: waiting for %s OnLoad status", 283 self->threadId, pEntry->pathName); 284 ThreadStatus oldStatus = dvmChangeStatus(self, THREAD_VMWAIT); 285 pthread_cond_wait(&pEntry->onLoadCond, &pEntry->onLoadLock); 286 dvmChangeStatus(self, oldStatus); 287 } 288 if (pEntry->onLoadResult == kOnLoadOkay) { 289 ALOGV("+++ earlier OnLoad(%s) okay", pEntry->pathName); 290 result = true; 291 } else { 292 ALOGV("+++ earlier OnLoad(%s) failed", pEntry->pathName); 293 result = false; 294 } 295 dvmUnlockMutex(&pEntry->onLoadLock); 296 return result; 297} 298 299typedef int (*OnLoadFunc)(JavaVM*, void*); 300 301/* 302 * Load native code from the specified absolute pathname. Per the spec, 303 * if we've already loaded a library with the specified pathname, we 304 * return without doing anything. 305 * 306 * TODO? for better results we should absolutify the pathname. For fully 307 * correct results we should stat to get the inode and compare that. The 308 * existing implementation is fine so long as everybody is using 309 * System.loadLibrary. 310 * 311 * The library will be associated with the specified class loader. The JNI 312 * spec says we can't load the same library into more than one class loader. 313 * 314 * Returns "true" on success. On failure, sets *detail to a 315 * human-readable description of the error or NULL if no detail is 316 * available; ownership of the string is transferred to the caller. 317 */ 318bool dvmLoadNativeCode(const char* pathName, Object* classLoader, 319 char** detail) 320{ 321 SharedLib* pEntry; 322 void* handle; 323 bool verbose; 324 325 /* reduce noise by not chattering about system libraries */ 326 verbose = !!strncmp(pathName, "/system", sizeof("/system")-1); 327 verbose = verbose && !!strncmp(pathName, "/vendor", sizeof("/vendor")-1); 328 329 if (verbose) 330 ALOGD("Trying to load lib %s %p", pathName, classLoader); 331 332 *detail = NULL; 333 334 /* 335 * See if we've already loaded it. If we have, and the class loader 336 * matches, return successfully without doing anything. 337 */ 338 pEntry = findSharedLibEntry(pathName); 339 if (pEntry != NULL) { 340 if (pEntry->classLoader != classLoader) { 341 ALOGW("Shared lib '%s' already opened by CL %p; can't open in %p", 342 pathName, pEntry->classLoader, classLoader); 343 return false; 344 } 345 if (verbose) { 346 ALOGD("Shared lib '%s' already loaded in same CL %p", 347 pathName, classLoader); 348 } 349 if (!checkOnLoadResult(pEntry)) 350 return false; 351 return true; 352 } 353 354 /* 355 * Open the shared library. Because we're using a full path, the system 356 * doesn't have to search through LD_LIBRARY_PATH. (It may do so to 357 * resolve this library's dependencies though.) 358 * 359 * Failures here are expected when java.library.path has several entries 360 * and we have to hunt for the lib. 361 * 362 * The current version of the dynamic linker prints detailed information 363 * about dlopen() failures. Some things to check if the message is 364 * cryptic: 365 * - make sure the library exists on the device 366 * - verify that the right path is being opened (the debug log message 367 * above can help with that) 368 * - check to see if the library is valid (e.g. not zero bytes long) 369 * - check config/prelink-linux-arm.map to ensure that the library 370 * is listed and is not being overrun by the previous entry (if 371 * loading suddenly stops working on a prelinked library, this is 372 * a good one to check) 373 * - write a trivial app that calls sleep() then dlopen(), attach 374 * to it with "strace -p <pid>" while it sleeps, and watch for 375 * attempts to open nonexistent dependent shared libs 376 * 377 * This can execute slowly for a large library on a busy system, so we 378 * want to switch from RUNNING to VMWAIT while it executes. This allows 379 * the GC to ignore us. 380 */ 381 Thread* self = dvmThreadSelf(); 382 ThreadStatus oldStatus = dvmChangeStatus(self, THREAD_VMWAIT); 383 handle = dlopen(pathName, RTLD_LAZY); 384 dvmChangeStatus(self, oldStatus); 385 386 if (handle == NULL) { 387 *detail = strdup(dlerror()); 388 ALOGE("dlopen(\"%s\") failed: %s", pathName, *detail); 389 return false; 390 } 391 392 /* create a new entry */ 393 SharedLib* pNewEntry; 394 pNewEntry = (SharedLib*) calloc(1, sizeof(SharedLib)); 395 pNewEntry->pathName = strdup(pathName); 396 pNewEntry->handle = handle; 397 pNewEntry->classLoader = classLoader; 398 dvmInitMutex(&pNewEntry->onLoadLock); 399 pthread_cond_init(&pNewEntry->onLoadCond, NULL); 400 pNewEntry->onLoadThreadId = self->threadId; 401 402 /* try to add it to the list */ 403 SharedLib* pActualEntry = addSharedLibEntry(pNewEntry); 404 405 if (pNewEntry != pActualEntry) { 406 ALOGI("WOW: we lost a race to add a shared lib (%s CL=%p)", 407 pathName, classLoader); 408 freeSharedLibEntry(pNewEntry); 409 return checkOnLoadResult(pActualEntry); 410 } else { 411 if (verbose) 412 ALOGD("Added shared lib %s %p", pathName, classLoader); 413 414 bool result = true; 415 void* vonLoad; 416 int version; 417 418 vonLoad = dlsym(handle, "JNI_OnLoad"); 419 if (vonLoad == NULL) { 420 ALOGD("No JNI_OnLoad found in %s %p, skipping init", 421 pathName, classLoader); 422 } else { 423 /* 424 * Call JNI_OnLoad. We have to override the current class 425 * loader, which will always be "null" since the stuff at the 426 * top of the stack is around Runtime.loadLibrary(). (See 427 * the comments in the JNI FindClass function.) 428 */ 429 OnLoadFunc func = (OnLoadFunc)vonLoad; 430 Object* prevOverride = self->classLoaderOverride; 431 432 self->classLoaderOverride = classLoader; 433 oldStatus = dvmChangeStatus(self, THREAD_NATIVE); 434 if (gDvm.verboseJni) { 435 ALOGI("[Calling JNI_OnLoad for \"%s\"]", pathName); 436 } 437 version = (*func)(gDvmJni.jniVm, NULL); 438 dvmChangeStatus(self, oldStatus); 439 self->classLoaderOverride = prevOverride; 440 441 if (version == JNI_ERR) { 442 *detail = strdup(StringPrintf("JNI_ERR returned from JNI_OnLoad in \"%s\"", 443 pathName).c_str()); 444 } else if (dvmIsBadJniVersion(version)) { 445 *detail = strdup(StringPrintf("Bad JNI version returned from JNI_OnLoad in \"%s\": %d", 446 pathName, version).c_str()); 447 /* 448 * It's unwise to call dlclose() here, but we can mark it 449 * as bad and ensure that future load attempts will fail. 450 * 451 * We don't know how far JNI_OnLoad got, so there could 452 * be some partially-initialized stuff accessible through 453 * newly-registered native method calls. We could try to 454 * unregister them, but that doesn't seem worthwhile. 455 */ 456 result = false; 457 } 458 if (gDvm.verboseJni) { 459 ALOGI("[Returned %s from JNI_OnLoad for \"%s\"]", 460 (result ? "successfully" : "failure"), pathName); 461 } 462 } 463 464 if (result) 465 pNewEntry->onLoadResult = kOnLoadOkay; 466 else 467 pNewEntry->onLoadResult = kOnLoadFailed; 468 469 pNewEntry->onLoadThreadId = 0; 470 471 /* 472 * Broadcast a wakeup to anybody sleeping on the condition variable. 473 */ 474 dvmLockMutex(&pNewEntry->onLoadLock); 475 pthread_cond_broadcast(&pNewEntry->onLoadCond); 476 dvmUnlockMutex(&pNewEntry->onLoadLock); 477 return result; 478 } 479} 480 481 482/* 483 * Un-register JNI native methods. 484 * 485 * There are two relevant fields in struct Method, "nativeFunc" and 486 * "insns". The former holds a function pointer to a "bridge" function 487 * (or, for internal native, the actual implementation). The latter holds 488 * a pointer to the actual JNI method. 489 * 490 * The obvious approach is to reset both fields to their initial state 491 * (nativeFunc points at dvmResolveNativeMethod, insns holds NULL), but 492 * that creates some unpleasant race conditions. In particular, if another 493 * thread is executing inside the call bridge for the method in question, 494 * and we reset insns to NULL, the VM will crash. (See the comments above 495 * dvmSetNativeFunc() for additional commentary.) 496 * 497 * We can't rely on being able to update two 32-bit fields in one atomic 498 * operation (e.g. no 64-bit atomic ops on ARMv5TE), so we want to change 499 * only one field. It turns out we can simply reset nativeFunc to its 500 * initial state, leaving insns alone, because dvmResolveNativeMethod 501 * ignores "insns" entirely. 502 * 503 * When the method is re-registered, both fields will be updated, but 504 * dvmSetNativeFunc guarantees that "insns" is updated first. This means 505 * we shouldn't be in a situation where we have a "live" call bridge and 506 * a stale implementation pointer. 507 */ 508static void unregisterJNINativeMethods(Method* methods, size_t count) 509{ 510 while (count != 0) { 511 count--; 512 513 Method* meth = &methods[count]; 514 if (!dvmIsNativeMethod(meth)) 515 continue; 516 if (dvmIsAbstractMethod(meth)) /* avoid abstract method stubs */ 517 continue; 518 519 /* 520 * Strictly speaking this ought to test the function pointer against 521 * the various JNI bridge functions to ensure that we only undo 522 * methods that were registered through JNI. In practice, any 523 * native method with a non-NULL "insns" is a registered JNI method. 524 * 525 * If we inadvertently unregister an internal-native, it'll get 526 * re-resolved on the next call; unregistering an unregistered 527 * JNI method is a no-op. So we don't really need to test for 528 * anything. 529 */ 530 531 ALOGD("Unregistering JNI method %s.%s:%s", 532 meth->clazz->descriptor, meth->name, meth->shorty); 533 dvmSetNativeFunc(meth, dvmResolveNativeMethod, NULL); 534 } 535} 536 537/* 538 * Un-register all JNI native methods from a class. 539 */ 540void dvmUnregisterJNINativeMethods(ClassObject* clazz) 541{ 542 unregisterJNINativeMethods(clazz->directMethods, clazz->directMethodCount); 543 unregisterJNINativeMethods(clazz->virtualMethods, clazz->virtualMethodCount); 544} 545 546 547/* 548 * =========================================================================== 549 * Signature-based method lookup 550 * =========================================================================== 551 */ 552 553/* 554 * Create the pre-mangled form of the class+method string. 555 * 556 * Returns a newly-allocated string, and sets "*pLen" to the length. 557 */ 558static char* createJniNameString(const char* classDescriptor, 559 const char* methodName, int* pLen) 560{ 561 char* result; 562 size_t descriptorLength = strlen(classDescriptor); 563 564 *pLen = 4 + descriptorLength + strlen(methodName); 565 566 result = (char*)malloc(*pLen +1); 567 if (result == NULL) 568 return NULL; 569 570 /* 571 * Add one to classDescriptor to skip the "L", and then replace 572 * the final ";" with a "/" after the sprintf() call. 573 */ 574 sprintf(result, "Java/%s%s", classDescriptor + 1, methodName); 575 result[5 + (descriptorLength - 2)] = '/'; 576 577 return result; 578} 579 580/* 581 * Returns a newly-allocated, mangled copy of "str". 582 * 583 * "str" is a "modified UTF-8" string. We convert it to UTF-16 first to 584 * make life simpler. 585 */ 586static char* mangleString(const char* str, int len) 587{ 588 //ALOGI("mangling '%s' %d", str, len); 589 590 assert(str[len] == '\0'); 591 592 size_t charLen = dvmUtf8Len(str); 593 u2* utf16 = (u2*) malloc(sizeof(u2) * charLen); 594 if (utf16 == NULL) 595 return NULL; 596 597 dvmConvertUtf8ToUtf16(utf16, str); 598 599 /* 600 * Compute the length of the mangled string. 601 */ 602 size_t mangleLen = 0; 603 for (size_t i = 0; i < charLen; i++) { 604 u2 ch = utf16[i]; 605 606 if (ch == '$' || ch > 127) { 607 mangleLen += 6; 608 } else { 609 switch (ch) { 610 case '_': 611 case ';': 612 case '[': 613 mangleLen += 2; 614 break; 615 default: 616 mangleLen++; 617 break; 618 } 619 } 620 } 621 622 char* mangle = (char*) malloc(mangleLen +1); 623 if (mangle == NULL) { 624 free(utf16); 625 return NULL; 626 } 627 628 char* cp = mangle; 629 for (size_t i = 0; i < charLen; i++) { 630 u2 ch = utf16[i]; 631 632 if (ch == '$' || ch > 127) { 633 sprintf(cp, "_0%04x", ch); 634 cp += 6; 635 } else { 636 switch (ch) { 637 case '_': 638 *cp++ = '_'; 639 *cp++ = '1'; 640 break; 641 case ';': 642 *cp++ = '_'; 643 *cp++ = '2'; 644 break; 645 case '[': 646 *cp++ = '_'; 647 *cp++ = '3'; 648 break; 649 case '/': 650 *cp++ = '_'; 651 break; 652 default: 653 *cp++ = (char) ch; 654 break; 655 } 656 } 657 } 658 659 *cp = '\0'; 660 661 free(utf16); 662 return mangle; 663} 664 665/* 666 * Create the mangled form of the parameter types. 667 */ 668static char* createMangledSignature(const DexProto* proto) 669{ 670 DexStringCache sigCache; 671 const char* interim; 672 char* result; 673 674 dexStringCacheInit(&sigCache); 675 interim = dexProtoGetParameterDescriptors(proto, &sigCache); 676 result = mangleString(interim, strlen(interim)); 677 dexStringCacheRelease(&sigCache); 678 679 return result; 680} 681 682/* 683 * (This is a dvmHashForeach callback.) 684 * 685 * Search for a matching method in this shared library. 686 * 687 * TODO: we may want to skip libraries for which JNI_OnLoad failed. 688 */ 689static int findMethodInLib(void* vlib, void* vmethod) 690{ 691 const SharedLib* pLib = (const SharedLib*) vlib; 692 const Method* meth = (const Method*) vmethod; 693 char* preMangleCM = NULL; 694 char* mangleCM = NULL; 695 char* mangleSig = NULL; 696 char* mangleCMSig = NULL; 697 void* func = NULL; 698 int len; 699 700 if (meth->clazz->classLoader != pLib->classLoader) { 701 ALOGV("+++ not scanning '%s' for '%s' (wrong CL)", 702 pLib->pathName, meth->name); 703 return 0; 704 } else 705 ALOGV("+++ scanning '%s' for '%s'", pLib->pathName, meth->name); 706 707 /* 708 * First, we try it without the signature. 709 */ 710 preMangleCM = 711 createJniNameString(meth->clazz->descriptor, meth->name, &len); 712 if (preMangleCM == NULL) 713 goto bail; 714 715 mangleCM = mangleString(preMangleCM, len); 716 if (mangleCM == NULL) 717 goto bail; 718 719 ALOGV("+++ calling dlsym(%s)", mangleCM); 720 func = dlsym(pLib->handle, mangleCM); 721 if (func == NULL) { 722 mangleSig = 723 createMangledSignature(&meth->prototype); 724 if (mangleSig == NULL) 725 goto bail; 726 727 mangleCMSig = (char*) malloc(strlen(mangleCM) + strlen(mangleSig) +3); 728 if (mangleCMSig == NULL) 729 goto bail; 730 731 sprintf(mangleCMSig, "%s__%s", mangleCM, mangleSig); 732 733 ALOGV("+++ calling dlsym(%s)", mangleCMSig); 734 func = dlsym(pLib->handle, mangleCMSig); 735 if (func != NULL) { 736 ALOGV("Found '%s' with dlsym", mangleCMSig); 737 } 738 } else { 739 ALOGV("Found '%s' with dlsym", mangleCM); 740 } 741 742bail: 743 free(preMangleCM); 744 free(mangleCM); 745 free(mangleSig); 746 free(mangleCMSig); 747 return (int) func; 748} 749 750/* 751 * See if the requested method lives in any of the currently-loaded 752 * shared libraries. We do this by checking each of them for the expected 753 * method signature. 754 */ 755static void* lookupSharedLibMethod(const Method* method) 756{ 757 if (gDvm.nativeLibs == NULL) { 758 ALOGE("Unexpected init state: nativeLibs not ready"); 759 dvmAbort(); 760 } 761 return (void*) dvmHashForeach(gDvm.nativeLibs, findMethodInLib, 762 (void*) method); 763} 764