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 "disassembler_arm.h"
18
19 #include <memory>
20 #include <string>
21
22 #include "android-base/logging.h"
23
24 #include "arch/arm/registers_arm.h"
25 #include "base/bit_utils.h"
26
27 #pragma GCC diagnostic push
28 #pragma GCC diagnostic ignored "-Wshadow"
29 #include "aarch32/instructions-aarch32.h"
30 #include "aarch32/disasm-aarch32.h"
31 #pragma GCC diagnostic pop
32
33 namespace art {
34 namespace arm {
35
36 using vixl::aarch32::MemOperand;
37 using vixl::aarch32::PrintDisassembler;
38 using vixl::aarch32::pc;
39
40 static const vixl::aarch32::Register tr(TR);
41
42 class DisassemblerArm::CustomDisassembler FINAL : public PrintDisassembler {
43 class CustomDisassemblerStream FINAL : public DisassemblerStream {
44 public:
CustomDisassemblerStream(std::ostream & os,const CustomDisassembler * disasm,const DisassemblerOptions * options)45 CustomDisassemblerStream(std::ostream& os,
46 const CustomDisassembler* disasm,
47 const DisassemblerOptions* options)
48 : DisassemblerStream(os), disasm_(disasm), options_(options) {}
49
operator <<(const PrintLabel & label)50 DisassemblerStream& operator<<(const PrintLabel& label) OVERRIDE {
51 const LocationType type = label.GetLocationType();
52
53 switch (type) {
54 case kLoadByteLocation:
55 case kLoadHalfWordLocation:
56 case kLoadWordLocation:
57 case kLoadDoubleWordLocation:
58 case kLoadSignedByteLocation:
59 case kLoadSignedHalfWordLocation:
60 case kLoadSinglePrecisionLocation:
61 case kLoadDoublePrecisionLocation:
62 case kVld1Location:
63 case kVld2Location:
64 case kVld3Location:
65 case kVld4Location: {
66 const uintptr_t pc_delta = label.GetLabel()->GetPcOffset();
67 const int32_t offset = label.GetLabel()->GetLocation();
68
69 os() << "[pc, #" << offset - pc_delta << "]";
70 PrintLiteral(type, offset);
71 return *this;
72 }
73 default:
74 return DisassemblerStream::operator<<(label);
75 }
76 }
77
operator <<(vixl::aarch32::Register reg)78 DisassemblerStream& operator<<(vixl::aarch32::Register reg) OVERRIDE {
79 if (reg.Is(tr)) {
80 os() << "tr";
81 return *this;
82 } else {
83 return DisassemblerStream::operator<<(reg);
84 }
85 }
86
operator <<(const MemOperand & operand)87 DisassemblerStream& operator<<(const MemOperand& operand) OVERRIDE {
88 // VIXL must use a PrintLabel object whenever the base register is PC;
89 // the following check verifies this invariant, and guards against bugs.
90 DCHECK(!operand.GetBaseRegister().Is(pc));
91 DisassemblerStream::operator<<(operand);
92
93 if (operand.GetBaseRegister().Is(tr) && operand.IsImmediate()) {
94 os() << " ; ";
95 options_->thread_offset_name_function_(os(), operand.GetOffsetImmediate());
96 }
97
98 return *this;
99 }
100
operator <<(const vixl::aarch32::AlignedMemOperand & operand)101 DisassemblerStream& operator<<(const vixl::aarch32::AlignedMemOperand& operand) OVERRIDE {
102 // VIXL must use a PrintLabel object whenever the base register is PC;
103 // the following check verifies this invariant, and guards against bugs.
104 DCHECK(!operand.GetBaseRegister().Is(pc));
105 return DisassemblerStream::operator<<(operand);
106 }
107
108 private:
109 void PrintLiteral(LocationType type, int32_t offset);
110
111 const CustomDisassembler* disasm_;
112 const DisassemblerOptions* options_;
113 };
114
115 public:
CustomDisassembler(std::ostream & os,const DisassemblerOptions * options)116 CustomDisassembler(std::ostream& os, const DisassemblerOptions* options)
117 : PrintDisassembler(&disassembler_stream_), disassembler_stream_(os, this, options) {}
118
PrintCodeAddress(uint32_t prog_ctr)119 void PrintCodeAddress(uint32_t prog_ctr) OVERRIDE {
120 os() << "0x" << std::hex << std::setw(8) << std::setfill('0') << prog_ctr << ": ";
121 }
122
123 private:
124 CustomDisassemblerStream disassembler_stream_;
125 };
126
PrintLiteral(LocationType type,int32_t offset)127 void DisassemblerArm::CustomDisassembler::CustomDisassemblerStream::PrintLiteral(LocationType type,
128 int32_t offset) {
129 // Literal offsets are not required to be aligned, so we may need unaligned access.
130 typedef const int16_t unaligned_int16_t __attribute__ ((aligned (1)));
131 typedef const uint16_t unaligned_uint16_t __attribute__ ((aligned (1)));
132 typedef const int32_t unaligned_int32_t __attribute__ ((aligned (1)));
133 typedef const int64_t unaligned_int64_t __attribute__ ((aligned (1)));
134 typedef const float unaligned_float __attribute__ ((aligned (1)));
135 typedef const double unaligned_double __attribute__ ((aligned (1)));
136
137 // Zeros are used for the LocationType values this function does not care about.
138 const size_t literal_size[kVst4Location + 1] = {
139 0, 0, 0, 0, sizeof(uint8_t), sizeof(unaligned_uint16_t), sizeof(unaligned_int32_t),
140 sizeof(unaligned_int64_t), sizeof(int8_t), sizeof(unaligned_int16_t),
141 sizeof(unaligned_float), sizeof(unaligned_double)};
142 const uintptr_t begin = reinterpret_cast<uintptr_t>(options_->base_address_);
143 const uintptr_t end = reinterpret_cast<uintptr_t>(options_->end_address_);
144 uintptr_t literal_addr = RoundDown(disasm_->GetCodeAddress(), vixl::aarch32::kRegSizeInBytes) + offset;
145
146 if (!options_->absolute_addresses_) {
147 literal_addr += begin;
148 }
149
150 os() << " ; ";
151
152 // Bail out if not within expected buffer range to avoid trying to fetch invalid literals
153 // (we can encounter them when interpreting raw data as instructions).
154 if (literal_addr < begin || literal_addr > end - literal_size[type]) {
155 os() << "(?)";
156 } else {
157 switch (type) {
158 case kLoadByteLocation:
159 os() << *reinterpret_cast<const uint8_t*>(literal_addr);
160 break;
161 case kLoadHalfWordLocation:
162 os() << *reinterpret_cast<unaligned_uint16_t*>(literal_addr);
163 break;
164 case kLoadWordLocation: {
165 const int32_t value = *reinterpret_cast<unaligned_int32_t*>(literal_addr);
166 os() << "0x" << std::hex << std::setw(8) << std::setfill('0') << value;
167 break;
168 }
169 case kLoadDoubleWordLocation: {
170 const int64_t value = *reinterpret_cast<unaligned_int64_t*>(literal_addr);
171 os() << "0x" << std::hex << std::setw(16) << std::setfill('0') << value;
172 break;
173 }
174 case kLoadSignedByteLocation:
175 os() << *reinterpret_cast<const int8_t*>(literal_addr);
176 break;
177 case kLoadSignedHalfWordLocation:
178 os() << *reinterpret_cast<unaligned_int16_t*>(literal_addr);
179 break;
180 case kLoadSinglePrecisionLocation:
181 os() << *reinterpret_cast<unaligned_float*>(literal_addr);
182 break;
183 case kLoadDoublePrecisionLocation:
184 os() << *reinterpret_cast<unaligned_double*>(literal_addr);
185 break;
186 default:
187 UNIMPLEMENTED(FATAL) << "Unexpected literal type: " << type;
188 }
189 }
190 }
191
DisassemblerArm(DisassemblerOptions * options)192 DisassemblerArm::DisassemblerArm(DisassemblerOptions* options)
193 : Disassembler(options), disasm_(std::make_unique<CustomDisassembler>(output_, options)) {}
194
Dump(std::ostream & os,const uint8_t * begin)195 size_t DisassemblerArm::Dump(std::ostream& os, const uint8_t* begin) {
196 uintptr_t next;
197 // Remove the Thumb specifier bit; no effect if begin does not point to T32 code.
198 const uintptr_t instr_ptr = reinterpret_cast<uintptr_t>(begin) & ~1;
199
200 const bool is_t32 = (reinterpret_cast<uintptr_t>(begin) & 1) != 0;
201 disasm_->SetCodeAddress(GetPc(instr_ptr));
202
203 if (is_t32) {
204 const uint16_t* const ip = reinterpret_cast<const uint16_t*>(instr_ptr);
205 const uint16_t* const end_address = reinterpret_cast<const uint16_t*>(
206 GetDisassemblerOptions()->end_address_);
207 next = reinterpret_cast<uintptr_t>(disasm_->DecodeT32At(ip, end_address));
208 } else {
209 const uint32_t* const ip = reinterpret_cast<const uint32_t*>(instr_ptr);
210 next = reinterpret_cast<uintptr_t>(disasm_->DecodeA32At(ip));
211 }
212
213 os << output_.str();
214 output_.str(std::string());
215 return next - instr_ptr;
216 }
217
Dump(std::ostream & os,const uint8_t * begin,const uint8_t * end)218 void DisassemblerArm::Dump(std::ostream& os, const uint8_t* begin, const uint8_t* end) {
219 DCHECK_LE(begin, end);
220
221 // Remove the Thumb specifier bit; no effect if begin does not point to T32 code.
222 const uintptr_t base = reinterpret_cast<uintptr_t>(begin) & ~1;
223
224 const bool is_t32 = (reinterpret_cast<uintptr_t>(begin) & 1) != 0;
225 disasm_->SetCodeAddress(GetPc(base));
226
227 if (is_t32) {
228 // The Thumb specifier bits cancel each other.
229 disasm_->DisassembleT32Buffer(reinterpret_cast<const uint16_t*>(base), end - begin);
230 } else {
231 disasm_->DisassembleA32Buffer(reinterpret_cast<const uint32_t*>(base), end - begin);
232 }
233
234 os << output_.str();
235 output_.str(std::string());
236 }
237
238 } // namespace arm
239 } // namespace art
240