/*
* Open up the reserved area and throw an exception. The reserved area
* should only be needed to create and initialize the exception itself.
*
* If we already opened it and we're continuing to overflow, abort the VM.
*
* We have to leave the "reserved" area open until the "catch" handler has
* finished doing its processing. This is because the catch handler may
* need to resolve classes, which requires calling into the class loader if
* the classes aren't already in the "initiating loader" list.
*/
void dvmHandleStackOverflow(Thread* self)
{
/*
* Can we make the reserved area available?
*/
if (self->stackOverflowed) {
/*
* Already did, nothing to do but bail.
*/
LOGE("DalvikVM: double-overflow of stack in threadid=%d; aborting\n",
self->threadId);
dvmDumpThread(self, false);
dvmAbort();
}
/* open it up to the full range */
LOGI("Stack overflow, expanding (%p to %p)\n", self->interpStackEnd,
self->interpStackStart - self->interpStackSize);
//dvmDumpThread(self, false);
self->interpStackEnd = self->interpStackStart - self->interpStackSize;
self->stackOverflowed = true;
/*
* If we were trying to throw an exception when the stack overflowed,
* we will blow up when doing the class lookup on StackOverflowError
* because of the pending exception. So, we clear it and make it
* the cause of the SOE.
*/
Object* excep = dvmGetException(self);
if (excep != NULL) {
LOGW("Stack overflow while throwing exception\n");
dvmClearException(self);
}
dvmThrowChainedException("Ljava/lang/StackOverflowError;", NULL, excep);
}
/*
* Find a class by name, initializing it if requested.
*/
ClassObject* dvmFindClassByName(StringObject* nameObj, Object* loader,
bool doInit)
{
ClassObject* clazz = NULL;
char* name = NULL;
char* descriptor = NULL;
if (nameObj == NULL) {
dvmThrowException("Ljava/lang/NullPointerException;", NULL);
goto bail;
}
name = dvmCreateCstrFromString(nameObj);
/*
* We need to validate and convert the name (from x.y.z to x/y/z). This
* is especially handy for array types, since we want to avoid
* auto-generating bogus array classes.
*/
if (!validateClassName(name)) {
LOGW("dvmFindClassByName rejecting '%s'\n", name);
dvmThrowException("Ljava/lang/ClassNotFoundException;", name);
goto bail;
}
descriptor = dvmDotToDescriptor(name);
if (descriptor == NULL) {
goto bail;
}
if (doInit)
clazz = dvmFindClass(descriptor, loader);
else
clazz = dvmFindClassNoInit(descriptor, loader);
if (clazz == NULL) {
LOGVV("FAIL: load %s (%d)\n", descriptor, doInit);
Thread* self = dvmThreadSelf();
Object* oldExcep = dvmGetException(self);
dvmAddTrackedAlloc(oldExcep, self); /* don't let this be GCed */
dvmClearException(self);
dvmThrowChainedException("Ljava/lang/ClassNotFoundException;",
name, oldExcep);
dvmReleaseTrackedAlloc(oldExcep, self);
} else {
LOGVV("GOOD: load %s (%d) --> %p ldr=%p\n",
descriptor, doInit, clazz, clazz->classLoader);
}
bail:
free(name);
free(descriptor);
return clazz;
}
/*
* 从指定的DEX文件中加载一个类，使用类加载器去初始化一个类对象
*/
static void Dalvik_dalvik_system_DexFile_defineClass(const u4* args,
JValue* pResult)
{
StringObject* nameObj = (StringObject*) args[0];
Object* loader = (Object*) args[1];
int cookie = args[2];
ClassObject* clazz = NULL;
DexOrJar* pDexOrJar = (DexOrJar*) cookie;
DvmDex* pDvmDex;
char* name;
char* descriptor;
name = dvmCreateCstrFromString(nameObj);
descriptor = dvmDotToDescriptor(name);
ALOGV("--- Explicit class load '%s' l=%p c=0x%08x",
descriptor, loader, cookie);
free(name);
if (!validateCookie(cookie))
RETURN_VOID();
if (pDexOrJar->isDex)
pDvmDex = dvmGetRawDexFileDex(pDexOrJar->pRawDexFile);
else
pDvmDex = dvmGetJarFileDex(pDexOrJar->pJarFile);
/* once we load something, we can't unmap the storage */
pDexOrJar->okayToFree = false;
clazz = dvmDefineClass(pDvmDex, descriptor, loader);
Thread* self = dvmThreadSelf();
if (dvmCheckException(self)) {
/*
* If we threw a "class not found" exception, stifle it, since the
* contract in the higher method says we simply return null if
* the class is not found.
*/
Object* excep = dvmGetException(self);
if (strcmp(excep->clazz->descriptor,
"Ljava/lang/ClassNotFoundException;") == 0 ||
strcmp(excep->clazz->descriptor,
"Ljava/lang/NoClassDefFoundError;") == 0)
{
dvmClearException(self);
}
clazz = NULL;
}
free(descriptor);
RETURN_PTR(clazz);
}
/*
* Open up the reserved area and throw an exception. The reserved area
* should only be needed to create and initialize the exception itself.
*
* If we already opened it and we're continuing to overflow, abort the VM.
*
* We have to leave the "reserved" area open until the "catch" handler has
* finished doing its processing. This is because the catch handler may
* need to resolve classes, which requires calling into the class loader if
* the classes aren't already in the "initiating loader" list.
*/
void dvmHandleStackOverflow(Thread* self, const Method* method)
{
/*
* Can we make the reserved area available?
*/
if (self->stackOverflowed) {
/*
* Already did, nothing to do but bail.
*/
LOGE("DalvikVM: double-overflow of stack in threadid=%d; aborting\n",
self->threadId);
dvmDumpThread(self, false);
dvmAbort();
}
/* open it up to the full range */
LOGI("threadid=%d: stack overflow on call to %s.%s:%s\n",
self->threadId,
method->clazz->descriptor, method->name, method->shorty);
StackSaveArea* saveArea = SAVEAREA_FROM_FP(self->curFrame);
LOGI(" method requires %d+%d+%d=%d bytes, fp is %p (%d left)\n",
method->registersSize * 4, sizeof(StackSaveArea), method->outsSize * 4,
(method->registersSize + method->outsSize) * 4 + sizeof(StackSaveArea),
saveArea, (u1*) saveArea - self->interpStackEnd);
LOGI(" expanding stack end (%p to %p)\n", self->interpStackEnd,
self->interpStackStart - self->interpStackSize);
//dvmDumpThread(self, false);
self->interpStackEnd = self->interpStackStart - self->interpStackSize;
self->stackOverflowed = true;
/*
* If we were trying to throw an exception when the stack overflowed,
* we will blow up when doing the class lookup on StackOverflowError
* because of the pending exception. So, we clear it and make it
* the cause of the SOE.
*/
Object* excep = dvmGetException(self);
if (excep != NULL) {
LOGW("Stack overflow while throwing exception\n");
dvmClearException(self);
}
dvmThrowChainedExceptionByClass(gDvm.classJavaLangStackOverflowError,
NULL, excep);
}
/*
* Wrap the now-pending exception in a different exception. This is useful
* for reflection stuff that wants to hand a checked exception back from a
* method that doesn't declare it.
*
* If something fails, an (unchecked) exception related to that failure
* will be pending instead.
*/
void dvmWrapException(const char* newExcepStr)
{
Thread* self = dvmThreadSelf();
Object* origExcep;
ClassObject* iteClass;
origExcep = dvmGetException(self);
dvmAddTrackedAlloc(origExcep, self); // don't let the GC free it
dvmClearException(self); // clear before class lookup
iteClass = dvmFindSystemClass(newExcepStr);
if (iteClass != NULL) {
Object* iteExcep;
Method* initMethod;
iteExcep = dvmAllocObject(iteClass, ALLOC_DEFAULT);
if (iteExcep != NULL) {
initMethod = dvmFindDirectMethodByDescriptor(iteClass, "<init>",
"(Ljava/lang/Throwable;)V");
if (initMethod != NULL) {
JValue unused;
dvmCallMethod(self, initMethod, iteExcep, &unused,
origExcep);
/* if <init> succeeded, replace the old exception */
if (!dvmCheckException(self))
dvmSetException(self, iteExcep);
}
dvmReleaseTrackedAlloc(iteExcep, NULL);
/* if initMethod doesn't exist, or failed... */
if (!dvmCheckException(self))
dvmSetException(self, origExcep);
} else {
/* leave OutOfMemoryError pending */
}
} else {
/* leave ClassNotFoundException pending */
}
assert(dvmCheckException(self));
dvmReleaseTrackedAlloc(origExcep, self);
}
/*
* private static Class defineClass(String name, ClassLoader loader,
* int cookie, ProtectionDomain pd)
*
* Load a class from a DEX file. This is roughly equivalent to defineClass()
* in a regular VM -- it's invoked by the class loader to cause the
* creation of a specific class. The difference is that the search for and
* reading of the bytes is done within the VM.
*
* The class name is a "binary name", e.g. "java.lang.String".
*
* Returns a null pointer with no exception if the class was not found.
* Throws an exception on other failures.
*/
static void Dalvik_dalvik_system_DexFile_defineClass(const u4* args,
JValue* pResult)
{
StringObject* nameObj = (StringObject*) args[0];
Object* loader = (Object*) args[1];
int cookie = args[2];
Object* pd = (Object*) args[3];
ClassObject* clazz = NULL;
DexOrJar* pDexOrJar = (DexOrJar*) cookie;
DvmDex* pDvmDex;
char* name;
char* descriptor;
name = dvmCreateCstrFromString(nameObj);
descriptor = dvmDotToDescriptor(name);
LOGV("--- Explicit class load '%s' 0x%08x\n", descriptor, cookie);
free(name);
if (!validateCookie(cookie))
RETURN_VOID();
if (pDexOrJar->isDex)
pDvmDex = dvmGetRawDexFileDex(pDexOrJar->pRawDexFile);
else
pDvmDex = dvmGetJarFileDex(pDexOrJar->pJarFile);
/* once we load something, we can't unmap the storage */
pDexOrJar->okayToFree = false;
clazz = dvmDefineClass(pDvmDex, descriptor, loader);
Thread* self = dvmThreadSelf();
if (dvmCheckException(self)) {
/*
* If we threw a "class not found" exception, stifle it, since the
* contract in the higher method says we simply return null if
* the class is not found.
*/
Object* excep = dvmGetException(self);
if (strcmp(excep->clazz->descriptor,
"Ljava/lang/ClassNotFoundException;") == 0 ||
strcmp(excep->clazz->descriptor,
"Ljava/lang/NoClassDefFoundError;") == 0)
{
dvmClearException(self);
}
clazz = NULL;
}
/*
* Set the ProtectionDomain -- do we need this to happen before we
* link the class and make it available? If so, we need to pass it
* through dvmDefineClass (and figure out some other
* stuff, like where it comes from for bootstrap classes).
*/
if (clazz != NULL) {
//LOGI("SETTING pd '%s' to %p\n", clazz->descriptor, pd);
dvmSetFieldObject((Object*) clazz, gDvm.offJavaLangClass_pd, pd);
}
free(descriptor);
RETURN_PTR(clazz);
}
/*
* Alternate version of dvmResolveClass for use with verification and
* optimization. Performs access checks on every resolve, and refuses
* to acknowledge the existence of classes defined in more than one DEX
* file.
*
* Exceptions caused by failures are cleared before returning.
*
* On failure, returns NULL, and sets *pFailure if pFailure is not NULL.
*/
ClassObject* dvmOptResolveClass(ClassObject* referrer, u4 classIdx,
VerifyError* pFailure)
{
DvmDex* pDvmDex = referrer->pDvmDex;
ClassObject* resClass;
/*
* Check the table first. If not there, do the lookup by name.
*/
resClass = dvmDexGetResolvedClass(pDvmDex, classIdx);
if (resClass == NULL) {
const char* className = dexStringByTypeIdx(pDvmDex->pDexFile, classIdx);
if (className[0] != '\0' && className[1] == '\0') {
/* primitive type */
resClass = dvmFindPrimitiveClass(className[0]);
} else {
resClass = dvmFindClassNoInit(className, referrer->classLoader);
}
if (resClass == NULL) {
/* not found, exception should be raised */
ALOGV("DexOpt: class %d (%s) not found",
classIdx,
dexStringByTypeIdx(pDvmDex->pDexFile, classIdx));
if (pFailure != NULL) {
/* dig through the wrappers to find the original failure */
Object* excep = dvmGetException(dvmThreadSelf());
while (true) {
Object* cause = dvmGetExceptionCause(excep);
if (cause == NULL)
break;
excep = cause;
}
if (strcmp(excep->clazz->descriptor,
"Ljava/lang/IncompatibleClassChangeError;") == 0)
{
*pFailure = VERIFY_ERROR_CLASS_CHANGE;
} else {
*pFailure = VERIFY_ERROR_NO_CLASS;
}
}
dvmClearOptException(dvmThreadSelf());
return NULL;
}
/*
* Add it to the resolved table so we're faster on the next lookup.
*/
dvmDexSetResolvedClass(pDvmDex, classIdx, resClass);
}
/* multiple definitions? */
if (IS_CLASS_FLAG_SET(resClass, CLASS_MULTIPLE_DEFS)) {
ALOGI("DexOpt: not resolving ambiguous class '%s'",
resClass->descriptor);
if (pFailure != NULL)
*pFailure = VERIFY_ERROR_NO_CLASS;
return NULL;
}
/* access allowed? */
tweakLoader(referrer, resClass);
bool allowed = dvmCheckClassAccess(referrer, resClass);
untweakLoader(referrer, resClass);
if (!allowed) {
ALOGW("DexOpt: resolve class illegal access: %s -> %s",
referrer->descriptor, resClass->descriptor);
if (pFailure != NULL)
*pFailure = VERIFY_ERROR_ACCESS_CLASS;
return NULL;
}
return resClass;
}