1 /*
2 * Copyright (C) 2012 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 #include <android-base/logging.h>
18
19 #include "arch/arm/jni_frame_arm.h"
20 #include "arch/arm64/jni_frame_arm64.h"
21 #include "arch/instruction_set.h"
22 #include "arch/x86/jni_frame_x86.h"
23 #include "arch/x86_64/jni_frame_x86_64.h"
24 #include "art_method-inl.h"
25 #include "dex/dex_instruction-inl.h"
26 #include "dex/method_reference.h"
27 #include "entrypoints/entrypoint_utils-inl.h"
28 #include "jni/java_vm_ext.h"
29 #include "mirror/object-inl.h"
30 #include "oat_quick_method_header.h"
31 #include "scoped_thread_state_change-inl.h"
32 #include "stack_map.h"
33 #include "thread.h"
34
35 namespace art {
36
GetInvokeStaticMethodIndex(ArtMethod * caller,uint32_t dex_pc)37 static inline uint32_t GetInvokeStaticMethodIndex(ArtMethod* caller, uint32_t dex_pc)
38 REQUIRES_SHARED(Locks::mutator_lock_) {
39 // Get the DexFile and method index.
40 const Instruction& instruction = caller->DexInstructions().InstructionAt(dex_pc);
41 DCHECK(instruction.Opcode() == Instruction::INVOKE_STATIC ||
42 instruction.Opcode() == Instruction::INVOKE_STATIC_RANGE);
43 uint32_t method_idx = (instruction.Opcode() == Instruction::INVOKE_STATIC)
44 ? instruction.VRegB_35c()
45 : instruction.VRegB_3rc();
46 return method_idx;
47 }
48
49 // Used by the JNI dlsym stub to find the native method to invoke if none is registered.
artFindNativeMethodRunnable(Thread * self)50 extern "C" const void* artFindNativeMethodRunnable(Thread* self)
51 REQUIRES_SHARED(Locks::mutator_lock_) {
52 Locks::mutator_lock_->AssertSharedHeld(self); // We come here as Runnable.
53 uint32_t dex_pc;
54 ArtMethod* method = self->GetCurrentMethod(&dex_pc);
55 DCHECK(method != nullptr);
56 ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
57
58 if (!method->IsNative()) {
59 // We're coming from compiled managed code and the `method` we see here is the caller.
60 // Resolve target @CriticalNative method for a direct call from compiled managed code.
61 uint32_t method_idx = GetInvokeStaticMethodIndex(method, dex_pc);
62 ArtMethod* target_method = class_linker->ResolveMethod<ClassLinker::ResolveMode::kNoChecks>(
63 self, method_idx, method, kStatic);
64 if (target_method == nullptr) {
65 self->AssertPendingException();
66 return nullptr;
67 }
68 DCHECK(target_method->IsCriticalNative());
69 MaybeUpdateBssMethodEntry(target_method, MethodReference(method->GetDexFile(), method_idx));
70
71 // These calls do not have an explicit class initialization check, so do the check now.
72 // (When going through the stub or GenericJNI, the check was already done.)
73 DCHECK(NeedsClinitCheckBeforeCall(target_method));
74 ObjPtr<mirror::Class> declaring_class = target_method->GetDeclaringClass();
75 if (UNLIKELY(!declaring_class->IsVisiblyInitialized())) {
76 StackHandleScope<1> hs(self);
77 Handle<mirror::Class> h_class(hs.NewHandle(declaring_class));
78 if (!class_linker->EnsureInitialized(self, h_class, true, true)) {
79 DCHECK(self->IsExceptionPending()) << method->PrettyMethod();
80 return nullptr;
81 }
82 }
83
84 // Replace the runtime method on the stack with the target method.
85 DCHECK(!self->GetManagedStack()->GetTopQuickFrameTag());
86 ArtMethod** sp = self->GetManagedStack()->GetTopQuickFrameKnownNotTagged();
87 DCHECK(*sp == Runtime::Current()->GetCalleeSaveMethod(CalleeSaveType::kSaveRefsAndArgs));
88 *sp = target_method;
89 self->SetTopOfStackTagged(sp); // Fake GenericJNI frame.
90
91 // Continue with the target method.
92 method = target_method;
93 }
94 DCHECK(method == self->GetCurrentMethod(/*dex_pc=*/ nullptr));
95
96 // Check whether we already have a registered native code.
97 // For @CriticalNative it may not be stored in the ArtMethod as a JNI entrypoint if the class
98 // was not visibly initialized yet. Do this check also for @FastNative and normal native for
99 // consistency; though success would mean that another thread raced to do this lookup.
100 const void* native_code = class_linker->GetRegisteredNative(self, method);
101 if (native_code != nullptr) {
102 return native_code;
103 }
104
105 // Lookup symbol address for method, on failure we'll return null with an exception set,
106 // otherwise we return the address of the method we found.
107 JavaVMExt* vm = down_cast<JNIEnvExt*>(self->GetJniEnv())->GetVm();
108 native_code = vm->FindCodeForNativeMethod(method);
109 if (native_code == nullptr) {
110 self->AssertPendingException();
111 return nullptr;
112 }
113
114 // Register the code. This usually prevents future calls from coming to this function again.
115 // We can still come here if the ClassLinker cannot set the entrypoint in the ArtMethod,
116 // i.e. for @CriticalNative methods with the declaring class not visibly initialized.
117 return class_linker->RegisterNative(self, method, native_code);
118 }
119
120 // Used by the JNI dlsym stub to find the native method to invoke if none is registered.
artFindNativeMethod(Thread * self)121 extern "C" const void* artFindNativeMethod(Thread* self) {
122 DCHECK_EQ(self, Thread::Current());
123 Locks::mutator_lock_->AssertNotHeld(self); // We come here as Native.
124 ScopedObjectAccess soa(self);
125 return artFindNativeMethodRunnable(self);
126 }
127
artCriticalNativeFrameSize(ArtMethod * method,uintptr_t caller_pc)128 extern "C" size_t artCriticalNativeFrameSize(ArtMethod* method, uintptr_t caller_pc)
129 REQUIRES_SHARED(Locks::mutator_lock_) {
130 if (method->IsNative()) {
131 // Get the method's shorty.
132 DCHECK(method->IsCriticalNative());
133 uint32_t shorty_len;
134 const char* shorty = method->GetShorty(&shorty_len);
135
136 // Return the platform-dependent stub frame size.
137 switch (kRuntimeISA) {
138 case InstructionSet::kArm:
139 case InstructionSet::kThumb2:
140 return arm::GetCriticalNativeStubFrameSize(shorty, shorty_len);
141 case InstructionSet::kArm64:
142 return arm64::GetCriticalNativeStubFrameSize(shorty, shorty_len);
143 case InstructionSet::kX86:
144 return x86::GetCriticalNativeStubFrameSize(shorty, shorty_len);
145 case InstructionSet::kX86_64:
146 return x86_64::GetCriticalNativeStubFrameSize(shorty, shorty_len);
147 default:
148 UNIMPLEMENTED(FATAL) << kRuntimeISA;
149 UNREACHABLE();
150 }
151 } else {
152 // We're coming from compiled managed code and the `method` we see here is the compiled
153 // method that made the call. Get the actual caller (may be inlined) and dex pc.
154 const OatQuickMethodHeader* current_code = method->GetOatQuickMethodHeader(caller_pc);
155 DCHECK(current_code != nullptr);
156 DCHECK(current_code->IsOptimized());
157 uintptr_t native_pc_offset = current_code->NativeQuickPcOffset(caller_pc);
158 CodeInfo code_info = CodeInfo::DecodeInlineInfoOnly(current_code);
159 StackMap stack_map = code_info.GetStackMapForNativePcOffset(native_pc_offset);
160 DCHECK(stack_map.IsValid());
161 BitTableRange<InlineInfo> inline_infos = code_info.GetInlineInfosOf(stack_map);
162 ArtMethod* caller =
163 inline_infos.empty() ? method : GetResolvedMethod(method, code_info, inline_infos);
164 uint32_t dex_pc = inline_infos.empty() ? stack_map.GetDexPc() : inline_infos.back().GetDexPc();
165
166 // Get the callee shorty.
167 const DexFile* dex_file = method->GetDexFile();
168 uint32_t method_idx = GetInvokeStaticMethodIndex(caller, dex_pc);
169 uint32_t shorty_len;
170 const char* shorty = dex_file->GetMethodShorty(dex_file->GetMethodId(method_idx), &shorty_len);
171
172 // Return the platform-dependent direct call frame size.
173 switch (kRuntimeISA) {
174 case InstructionSet::kArm:
175 case InstructionSet::kThumb2:
176 return arm::GetCriticalNativeDirectCallFrameSize(shorty, shorty_len);
177 case InstructionSet::kArm64:
178 return arm64::GetCriticalNativeDirectCallFrameSize(shorty, shorty_len);
179 case InstructionSet::kX86:
180 return x86::GetCriticalNativeDirectCallFrameSize(shorty, shorty_len);
181 case InstructionSet::kX86_64:
182 return x86_64::GetCriticalNativeDirectCallFrameSize(shorty, shorty_len);
183 default:
184 UNIMPLEMENTED(FATAL) << kRuntimeISA;
185 UNREACHABLE();
186 }
187 }
188 }
189
190 } // namespace art
191