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/*
* Copyright (C) 2012 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "base/logging.h"
#include "entrypoints/entrypoint_utils.h"
#include "mirror/art_method-inl.h"
#include "mirror/object-inl.h"
#include "object_utils.h"
#include "scoped_thread_state_change.h"
#include "thread.h"
namespace art {
// Used by the JNI dlsym stub to find the native method to invoke if none is registered.
extern "C" void* artFindNativeMethod() {
Thread* self = Thread::Current();
Locks::mutator_lock_->AssertNotHeld(self); // We come here as Native.
ScopedObjectAccess soa(self);
mirror::ArtMethod* method = self->GetCurrentMethod(NULL);
DCHECK(method != NULL);
// Lookup symbol address for method, on failure we'll return NULL with an exception set,
// otherwise we return the address of the method we found.
void* native_code = soa.Vm()->FindCodeForNativeMethod(method);
if (native_code == NULL) {
DCHECK(self->IsExceptionPending());
return NULL;
} else {
// Register so that future calls don't come here
method->RegisterNative(self, native_code, false);
return native_code;
}
}
static void WorkAroundJniBugsForJobject(intptr_t* arg_ptr)
SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
intptr_t value = *arg_ptr;
mirror::Object** value_as_jni_rep = reinterpret_cast<mirror::Object**>(value);
mirror::Object* value_as_work_around_rep = value_as_jni_rep != NULL ? *value_as_jni_rep : NULL;
CHECK(Runtime::Current()->GetHeap()->IsValidObjectAddress(value_as_work_around_rep))
<< value_as_work_around_rep;
*arg_ptr = reinterpret_cast<intptr_t>(value_as_work_around_rep);
}
extern "C" const void* artWorkAroundAppJniBugs(Thread* self, intptr_t* sp)
SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
DCHECK(Thread::Current() == self);
// TODO: this code is specific to ARM
// On entry the stack pointed by sp is:
// | arg3 | <- Calling JNI method's frame (and extra bit for out args)
// | LR |
// | R3 | arg2
// | R2 | arg1
// | R1 | jclass/jobject
// | R0 | JNIEnv
// | unused |
// | unused |
// | unused | <- sp
mirror::ArtMethod* jni_method = self->GetCurrentMethod(NULL);
DCHECK(jni_method->IsNative()) << PrettyMethod(jni_method);
intptr_t* arg_ptr = sp + 4; // pointer to r1 on stack
// Fix up this/jclass argument
WorkAroundJniBugsForJobject(arg_ptr);
arg_ptr++;
// Fix up jobject arguments
MethodHelper mh(jni_method);
int reg_num = 2; // Current register being processed, -1 for stack arguments.
for (uint32_t i = 1; i < mh.GetShortyLength(); i++) {
char shorty_char = mh.GetShorty()[i];
if (shorty_char == 'L') {
WorkAroundJniBugsForJobject(arg_ptr);
}
if (shorty_char == 'J' || shorty_char == 'D') {
if (reg_num == 2) {
arg_ptr = sp + 8; // skip to out arguments
reg_num = -1;
} else if (reg_num == 3) {
arg_ptr = sp + 10; // skip to out arguments plus 2 slots as long must be aligned
reg_num = -1;
} else {
DCHECK_EQ(reg_num, -1);
if ((reinterpret_cast<intptr_t>(arg_ptr) & 7) == 4) {
arg_ptr += 3; // unaligned, pad and move through stack arguments
} else {
arg_ptr += 2; // aligned, move through stack arguments
}
}
} else {
if (reg_num == 2) {
arg_ptr++; // move through register arguments
reg_num++;
} else if (reg_num == 3) {
arg_ptr = sp + 8; // skip to outgoing stack arguments
reg_num = -1;
} else {
DCHECK_EQ(reg_num, -1);
arg_ptr++; // move through stack arguments
}
}
}
// Load expected destination, see Method::RegisterNative
const void* code = reinterpret_cast<const void*>(jni_method->GetNativeGcMap());
if (UNLIKELY(code == NULL)) {
code = GetJniDlsymLookupStub();
jni_method->RegisterNative(self, code, false);
}
return code;
}
} // namespace art
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