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 #ifdef ART_ENABLE_CODEGEN_arm
20 #include "linker/arm/relative_patcher_thumb2.h"
21 #endif
22 #ifdef ART_ENABLE_CODEGEN_arm64
23 #include "linker/arm64/relative_patcher_arm64.h"
24 #endif
25 #ifdef ART_ENABLE_CODEGEN_x86
26 #include "linker/x86/relative_patcher_x86.h"
27 #endif
28 #ifdef ART_ENABLE_CODEGEN_x86_64
29 #include "linker/x86_64/relative_patcher_x86_64.h"
30 #endif
31 #include "output_stream.h"
32 
33 namespace art {
34 namespace linker {
35 
Create(InstructionSet instruction_set,const InstructionSetFeatures * features,RelativePatcherTargetProvider * provider)36 std::unique_ptr<RelativePatcher> RelativePatcher::Create(
37     InstructionSet instruction_set,
38     const InstructionSetFeatures* features,
39     RelativePatcherTargetProvider* provider) {
40   class RelativePatcherNone FINAL : public RelativePatcher {
41    public:
42     RelativePatcherNone() { }
43 
44     uint32_t ReserveSpace(uint32_t offset,
45                           const CompiledMethod* compiled_method ATTRIBUTE_UNUSED,
46                           MethodReference method_ref ATTRIBUTE_UNUSED) OVERRIDE {
47       return offset;  // No space reserved; no patches expected.
48     }
49 
50     uint32_t ReserveSpaceEnd(uint32_t offset) OVERRIDE {
51       return offset;  // No space reserved; no patches expected.
52     }
53 
54     uint32_t WriteThunks(OutputStream* out ATTRIBUTE_UNUSED, uint32_t offset) OVERRIDE {
55       return offset;  // No thunks added; no patches expected.
56     }
57 
58     void PatchCall(std::vector<uint8_t>* code ATTRIBUTE_UNUSED,
59                    uint32_t literal_offset ATTRIBUTE_UNUSED,
60                    uint32_t patch_offset ATTRIBUTE_UNUSED,
61                    uint32_t target_offset ATTRIBUTE_UNUSED) OVERRIDE {
62       LOG(FATAL) << "Unexpected relative call patch.";
63     }
64 
65     void PatchPcRelativeReference(std::vector<uint8_t>* code ATTRIBUTE_UNUSED,
66                                   const LinkerPatch& patch ATTRIBUTE_UNUSED,
67                                   uint32_t patch_offset ATTRIBUTE_UNUSED,
68                                   uint32_t target_offset ATTRIBUTE_UNUSED) OVERRIDE {
69       LOG(FATAL) << "Unexpected relative dex cache array patch.";
70     }
71 
72    private:
73     DISALLOW_COPY_AND_ASSIGN(RelativePatcherNone);
74   };
75 
76   UNUSED(features);
77   UNUSED(provider);
78   switch (instruction_set) {
79 #ifdef ART_ENABLE_CODEGEN_x86
80     case kX86:
81       return std::unique_ptr<RelativePatcher>(new X86RelativePatcher());
82 #endif
83 #ifdef ART_ENABLE_CODEGEN_x86_64
84     case kX86_64:
85       return std::unique_ptr<RelativePatcher>(new X86_64RelativePatcher());
86 #endif
87 #ifdef ART_ENABLE_CODEGEN_arm
88     case kArm:
89       // Fall through: we generate Thumb2 code for "arm".
90     case kThumb2:
91       return std::unique_ptr<RelativePatcher>(new Thumb2RelativePatcher(provider));
92 #endif
93 #ifdef ART_ENABLE_CODEGEN_arm64
94     case kArm64:
95       return std::unique_ptr<RelativePatcher>(
96           new Arm64RelativePatcher(provider, features->AsArm64InstructionSetFeatures()));
97 #endif
98     default:
99       return std::unique_ptr<RelativePatcher>(new RelativePatcherNone);
100   }
101 }
102 
WriteCodeAlignment(OutputStream * out,uint32_t aligned_code_delta)103 bool RelativePatcher::WriteCodeAlignment(OutputStream* out, uint32_t aligned_code_delta) {
104   static const uint8_t kPadding[] = {
105       0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u
106   };
107   DCHECK_LE(aligned_code_delta, sizeof(kPadding));
108   if (UNLIKELY(!out->WriteFully(kPadding, aligned_code_delta))) {
109     return false;
110   }
111   size_code_alignment_ += aligned_code_delta;
112   return true;
113 }
114 
WriteRelCallThunk(OutputStream * out,const ArrayRef<const uint8_t> & thunk)115 bool RelativePatcher::WriteRelCallThunk(OutputStream* out, const ArrayRef<const uint8_t>& thunk) {
116   if (UNLIKELY(!out->WriteFully(thunk.data(), thunk.size()))) {
117     return false;
118   }
119   size_relative_call_thunks_ += thunk.size();
120   return true;
121 }
122 
WriteMiscThunk(OutputStream * out,const ArrayRef<const uint8_t> & thunk)123 bool RelativePatcher::WriteMiscThunk(OutputStream* out, const ArrayRef<const uint8_t>& thunk) {
124   if (UNLIKELY(!out->WriteFully(thunk.data(), thunk.size()))) {
125     return false;
126   }
127   size_misc_thunks_ += thunk.size();
128   return true;
129 }
130 
131 }  // namespace linker
132 }  // namespace art
133