1 /*
2  * Copyright (C) 2015 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 "linker/relative_patcher.h"
18 
19 #include "debug/method_debug_info.h"
20 #ifdef ART_ENABLE_CODEGEN_arm
21 #include "linker/arm/relative_patcher_thumb2.h"
22 #endif
23 #ifdef ART_ENABLE_CODEGEN_arm64
24 #include "linker/arm64/relative_patcher_arm64.h"
25 #endif
26 #ifdef ART_ENABLE_CODEGEN_riscv64
27 #include "linker/riscv64/relative_patcher_riscv64.h"
28 #endif
29 #ifdef ART_ENABLE_CODEGEN_x86
30 #include "linker/x86/relative_patcher_x86.h"
31 #endif
32 #ifdef ART_ENABLE_CODEGEN_x86_64
33 #include "linker/x86_64/relative_patcher_x86_64.h"
34 #endif
35 #include "stream/output_stream.h"
36 
37 namespace art {
38 namespace linker {
39 
Create(InstructionSet instruction_set,const InstructionSetFeatures * features,RelativePatcherThunkProvider * thunk_provider,RelativePatcherTargetProvider * target_provider)40 std::unique_ptr<RelativePatcher> RelativePatcher::Create(
41     InstructionSet instruction_set,
42     const InstructionSetFeatures* features,
43     RelativePatcherThunkProvider* thunk_provider,
44     RelativePatcherTargetProvider* target_provider) {
45   class RelativePatcherNone final : public RelativePatcher {
46    public:
47     RelativePatcherNone() { }
48 
49     uint32_t ReserveSpace(uint32_t offset,
50                           [[maybe_unused]] const CompiledMethod* compiled_method,
51                           [[maybe_unused]] MethodReference method_ref) override {
52       return offset;  // No space reserved; no patches expected.
53     }
54 
55     uint32_t ReserveSpaceEnd(uint32_t offset) override {
56       return offset;  // No space reserved; no patches expected.
57     }
58 
59     uint32_t WriteThunks([[maybe_unused]] OutputStream* out, uint32_t offset) override {
60       return offset;  // No thunks added; no patches expected.
61     }
62 
63     void PatchCall([[maybe_unused]] std::vector<uint8_t>* code,
64                    [[maybe_unused]] uint32_t literal_offset,
65                    [[maybe_unused]] uint32_t patch_offset,
66                    [[maybe_unused]] uint32_t target_offset) override {
67       LOG(FATAL) << "Unexpected relative call patch.";
68     }
69 
70     void PatchPcRelativeReference([[maybe_unused]] std::vector<uint8_t>* code,
71                                   [[maybe_unused]] const LinkerPatch& patch,
72                                   [[maybe_unused]] uint32_t patch_offset,
73                                   [[maybe_unused]] uint32_t target_offset) override {
74       LOG(FATAL) << "Unexpected relative dex cache array patch.";
75     }
76 
77     void PatchEntrypointCall([[maybe_unused]] std::vector<uint8_t>* code,
78                              [[maybe_unused]] const LinkerPatch& patch,
79                              [[maybe_unused]] uint32_t patch_offset) override {
80       LOG(FATAL) << "Unexpected entrypoint call patch.";
81     }
82 
83     void PatchBakerReadBarrierBranch([[maybe_unused]] std::vector<uint8_t>* code,
84                                      [[maybe_unused]] const LinkerPatch& patch,
85                                      [[maybe_unused]] uint32_t patch_offset) override {
86       LOG(FATAL) << "Unexpected baker read barrier branch patch.";
87     }
88 
89     std::vector<debug::MethodDebugInfo> GenerateThunkDebugInfo(
90         [[maybe_unused]] uint32_t executable_offset) override {
91       return std::vector<debug::MethodDebugInfo>();  // No thunks added.
92     }
93 
94    private:
95     DISALLOW_COPY_AND_ASSIGN(RelativePatcherNone);
96   };
97 
98   UNUSED(features);
99   UNUSED(thunk_provider);
100   UNUSED(target_provider);
101   switch (instruction_set) {
102 #ifdef ART_ENABLE_CODEGEN_x86
103     case InstructionSet::kX86:
104       return std::unique_ptr<RelativePatcher>(new X86RelativePatcher());
105 #endif
106 #ifdef ART_ENABLE_CODEGEN_x86_64
107     case InstructionSet::kX86_64:
108       return std::unique_ptr<RelativePatcher>(new X86_64RelativePatcher());
109 #endif
110 #ifdef ART_ENABLE_CODEGEN_arm
111     case InstructionSet::kArm:
112       // Fall through: we generate Thumb2 code for "arm".
113     case InstructionSet::kThumb2:
114       return std::unique_ptr<RelativePatcher>(
115           new Thumb2RelativePatcher(thunk_provider, target_provider));
116 #endif
117 #ifdef ART_ENABLE_CODEGEN_arm64
118     case InstructionSet::kArm64:
119       return std::unique_ptr<RelativePatcher>(
120           new Arm64RelativePatcher(thunk_provider,
121                                    target_provider,
122                                    features->AsArm64InstructionSetFeatures()));
123 #endif
124 #ifdef ART_ENABLE_CODEGEN_riscv64
125     case InstructionSet::kRiscv64:
126       return std::unique_ptr<RelativePatcher>(
127           new Riscv64RelativePatcher(thunk_provider,
128                                      target_provider,
129                                      features->AsRiscv64InstructionSetFeatures()));
130 #endif
131     default:
132       return std::unique_ptr<RelativePatcher>(new RelativePatcherNone);
133   }
134 }
135 
WriteCodeAlignment(OutputStream * out,uint32_t aligned_code_delta)136 bool RelativePatcher::WriteCodeAlignment(OutputStream* out, uint32_t aligned_code_delta) {
137   static const uint8_t kPadding[] = {
138       0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u
139   };
140   DCHECK_LE(aligned_code_delta, sizeof(kPadding));
141   if (UNLIKELY(!out->WriteFully(kPadding, aligned_code_delta))) {
142     return false;
143   }
144   size_code_alignment_ += aligned_code_delta;
145   return true;
146 }
147 
WriteThunk(OutputStream * out,const ArrayRef<const uint8_t> & thunk)148 bool RelativePatcher::WriteThunk(OutputStream* out, const ArrayRef<const uint8_t>& thunk) {
149   if (UNLIKELY(!out->WriteFully(thunk.data(), thunk.size()))) {
150     return false;
151   }
152   size_relative_call_thunks_ += thunk.size();
153   return true;
154 }
155 
WriteMiscThunk(OutputStream * out,const ArrayRef<const uint8_t> & thunk)156 bool RelativePatcher::WriteMiscThunk(OutputStream* out, const ArrayRef<const uint8_t>& thunk) {
157   if (UNLIKELY(!out->WriteFully(thunk.data(), thunk.size()))) {
158     return false;
159   }
160   size_misc_thunks_ += thunk.size();
161   return true;
162 }
163 
164 }  // namespace linker
165 }  // namespace art
166