Christopher Ferris | 72a6fa6 | 2017-03-21 12:41:17 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2017 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 | |
Christopher Ferris | 72a6fa6 | 2017-03-21 12:41:17 -0700 | [diff] [blame] | 17 | #include <stdint.h> |
| 18 | |
| 19 | #include <string> |
| 20 | |
Christopher Ferris | d226a51 | 2017-07-14 10:37:19 -0700 | [diff] [blame] | 21 | #include <unwindstack/DwarfMemory.h> |
| 22 | #include <unwindstack/Memory.h> |
| 23 | |
Christopher Ferris | 9416703 | 2017-06-28 18:56:52 -0700 | [diff] [blame] | 24 | #include "Check.h" |
Christopher Ferris | 72a6fa6 | 2017-03-21 12:41:17 -0700 | [diff] [blame] | 25 | #include "DwarfEncoding.h" |
Christopher Ferris | d226a51 | 2017-07-14 10:37:19 -0700 | [diff] [blame] | 26 | |
| 27 | namespace unwindstack { |
Christopher Ferris | 72a6fa6 | 2017-03-21 12:41:17 -0700 | [diff] [blame] | 28 | |
| 29 | bool DwarfMemory::ReadBytes(void* dst, size_t num_bytes) { |
| 30 | if (!memory_->Read(cur_offset_, dst, num_bytes)) { |
| 31 | return false; |
| 32 | } |
| 33 | cur_offset_ += num_bytes; |
| 34 | return true; |
| 35 | } |
| 36 | |
| 37 | template <typename SignedType> |
| 38 | bool DwarfMemory::ReadSigned(uint64_t* value) { |
| 39 | SignedType signed_value; |
| 40 | if (!ReadBytes(&signed_value, sizeof(SignedType))) { |
| 41 | return false; |
| 42 | } |
| 43 | *value = static_cast<int64_t>(signed_value); |
| 44 | return true; |
| 45 | } |
| 46 | |
| 47 | bool DwarfMemory::ReadULEB128(uint64_t* value) { |
| 48 | uint64_t cur_value = 0; |
| 49 | uint64_t shift = 0; |
| 50 | uint8_t byte; |
| 51 | do { |
| 52 | if (!ReadBytes(&byte, 1)) { |
| 53 | return false; |
| 54 | } |
| 55 | cur_value += static_cast<uint64_t>(byte & 0x7f) << shift; |
| 56 | shift += 7; |
| 57 | } while (byte & 0x80); |
| 58 | *value = cur_value; |
| 59 | return true; |
| 60 | } |
| 61 | |
| 62 | bool DwarfMemory::ReadSLEB128(int64_t* value) { |
| 63 | uint64_t cur_value = 0; |
| 64 | uint64_t shift = 0; |
| 65 | uint8_t byte; |
| 66 | do { |
| 67 | if (!ReadBytes(&byte, 1)) { |
| 68 | return false; |
| 69 | } |
| 70 | cur_value += static_cast<uint64_t>(byte & 0x7f) << shift; |
| 71 | shift += 7; |
| 72 | } while (byte & 0x80); |
| 73 | if (byte & 0x40) { |
| 74 | // Negative value, need to sign extend. |
| 75 | cur_value |= static_cast<uint64_t>(-1) << shift; |
| 76 | } |
| 77 | *value = static_cast<int64_t>(cur_value); |
| 78 | return true; |
| 79 | } |
| 80 | |
| 81 | template <typename AddressType> |
| 82 | size_t DwarfMemory::GetEncodedSize(uint8_t encoding) { |
| 83 | switch (encoding & 0x0f) { |
| 84 | case DW_EH_PE_absptr: |
| 85 | return sizeof(AddressType); |
| 86 | case DW_EH_PE_udata1: |
| 87 | case DW_EH_PE_sdata1: |
| 88 | return 1; |
| 89 | case DW_EH_PE_udata2: |
| 90 | case DW_EH_PE_sdata2: |
| 91 | return 2; |
| 92 | case DW_EH_PE_udata4: |
| 93 | case DW_EH_PE_sdata4: |
| 94 | return 4; |
| 95 | case DW_EH_PE_udata8: |
| 96 | case DW_EH_PE_sdata8: |
| 97 | return 8; |
| 98 | case DW_EH_PE_uleb128: |
| 99 | case DW_EH_PE_sleb128: |
| 100 | default: |
| 101 | return 0; |
| 102 | } |
| 103 | } |
| 104 | |
| 105 | bool DwarfMemory::AdjustEncodedValue(uint8_t encoding, uint64_t* value) { |
Christopher Ferris | 9416703 | 2017-06-28 18:56:52 -0700 | [diff] [blame] | 106 | CHECK((encoding & 0x0f) == 0); |
| 107 | CHECK(encoding != DW_EH_PE_aligned); |
Christopher Ferris | 72a6fa6 | 2017-03-21 12:41:17 -0700 | [diff] [blame] | 108 | |
| 109 | // Handle the encoding. |
| 110 | switch (encoding) { |
| 111 | case DW_EH_PE_absptr: |
| 112 | // Nothing to do. |
| 113 | break; |
| 114 | case DW_EH_PE_pcrel: |
| 115 | if (pc_offset_ == static_cast<uint64_t>(-1)) { |
| 116 | // Unsupported encoding. |
| 117 | return false; |
| 118 | } |
| 119 | *value += pc_offset_; |
| 120 | break; |
| 121 | case DW_EH_PE_textrel: |
| 122 | if (text_offset_ == static_cast<uint64_t>(-1)) { |
| 123 | // Unsupported encoding. |
| 124 | return false; |
| 125 | } |
| 126 | *value += text_offset_; |
| 127 | break; |
| 128 | case DW_EH_PE_datarel: |
| 129 | if (data_offset_ == static_cast<uint64_t>(-1)) { |
| 130 | // Unsupported encoding. |
| 131 | return false; |
| 132 | } |
| 133 | *value += data_offset_; |
| 134 | break; |
| 135 | case DW_EH_PE_funcrel: |
| 136 | if (func_offset_ == static_cast<uint64_t>(-1)) { |
| 137 | // Unsupported encoding. |
| 138 | return false; |
| 139 | } |
| 140 | *value += func_offset_; |
| 141 | break; |
| 142 | default: |
| 143 | return false; |
| 144 | } |
| 145 | |
| 146 | return true; |
| 147 | } |
| 148 | |
| 149 | template <typename AddressType> |
| 150 | bool DwarfMemory::ReadEncodedValue(uint8_t encoding, uint64_t* value) { |
| 151 | if (encoding == DW_EH_PE_omit) { |
| 152 | *value = 0; |
| 153 | return true; |
| 154 | } else if (encoding == DW_EH_PE_aligned) { |
| 155 | if (__builtin_add_overflow(cur_offset_, sizeof(AddressType) - 1, &cur_offset_)) { |
| 156 | return false; |
| 157 | } |
| 158 | cur_offset_ &= -sizeof(AddressType); |
| 159 | |
| 160 | if (sizeof(AddressType) != sizeof(uint64_t)) { |
| 161 | *value = 0; |
| 162 | } |
| 163 | return ReadBytes(value, sizeof(AddressType)); |
| 164 | } |
| 165 | |
| 166 | // Get the data. |
| 167 | switch (encoding & 0x0f) { |
| 168 | case DW_EH_PE_absptr: |
| 169 | if (sizeof(AddressType) != sizeof(uint64_t)) { |
| 170 | *value = 0; |
| 171 | } |
| 172 | if (!ReadBytes(value, sizeof(AddressType))) { |
| 173 | return false; |
| 174 | } |
| 175 | break; |
| 176 | case DW_EH_PE_uleb128: |
| 177 | if (!ReadULEB128(value)) { |
| 178 | return false; |
| 179 | } |
| 180 | break; |
| 181 | case DW_EH_PE_sleb128: |
| 182 | int64_t signed_value; |
| 183 | if (!ReadSLEB128(&signed_value)) { |
| 184 | return false; |
| 185 | } |
| 186 | *value = static_cast<uint64_t>(signed_value); |
| 187 | break; |
| 188 | case DW_EH_PE_udata1: { |
| 189 | uint8_t value8; |
| 190 | if (!ReadBytes(&value8, 1)) { |
| 191 | return false; |
| 192 | } |
| 193 | *value = value8; |
| 194 | } break; |
| 195 | case DW_EH_PE_sdata1: |
| 196 | if (!ReadSigned<int8_t>(value)) { |
| 197 | return false; |
| 198 | } |
| 199 | break; |
| 200 | case DW_EH_PE_udata2: { |
| 201 | uint16_t value16; |
| 202 | if (!ReadBytes(&value16, 2)) { |
| 203 | return false; |
| 204 | } |
| 205 | *value = value16; |
| 206 | } break; |
| 207 | case DW_EH_PE_sdata2: |
| 208 | if (!ReadSigned<int16_t>(value)) { |
| 209 | return false; |
| 210 | } |
| 211 | break; |
| 212 | case DW_EH_PE_udata4: { |
| 213 | uint32_t value32; |
| 214 | if (!ReadBytes(&value32, 4)) { |
| 215 | return false; |
| 216 | } |
| 217 | *value = value32; |
| 218 | } break; |
| 219 | case DW_EH_PE_sdata4: |
| 220 | if (!ReadSigned<int32_t>(value)) { |
| 221 | return false; |
| 222 | } |
| 223 | break; |
| 224 | case DW_EH_PE_udata8: |
| 225 | if (!ReadBytes(value, sizeof(uint64_t))) { |
| 226 | return false; |
| 227 | } |
| 228 | break; |
| 229 | case DW_EH_PE_sdata8: |
| 230 | if (!ReadSigned<int64_t>(value)) { |
| 231 | return false; |
| 232 | } |
| 233 | break; |
| 234 | default: |
| 235 | return false; |
| 236 | } |
| 237 | |
Christopher Ferris | 9e484bd | 2017-08-10 17:37:32 -0700 | [diff] [blame] | 238 | return AdjustEncodedValue(encoding & 0x70, value); |
Christopher Ferris | 72a6fa6 | 2017-03-21 12:41:17 -0700 | [diff] [blame] | 239 | } |
| 240 | |
| 241 | // Instantiate all of the needed template functions. |
| 242 | template bool DwarfMemory::ReadSigned<int8_t>(uint64_t*); |
| 243 | template bool DwarfMemory::ReadSigned<int16_t>(uint64_t*); |
| 244 | template bool DwarfMemory::ReadSigned<int32_t>(uint64_t*); |
| 245 | template bool DwarfMemory::ReadSigned<int64_t>(uint64_t*); |
| 246 | |
| 247 | template size_t DwarfMemory::GetEncodedSize<uint32_t>(uint8_t); |
| 248 | template size_t DwarfMemory::GetEncodedSize<uint64_t>(uint8_t); |
| 249 | |
| 250 | template bool DwarfMemory::ReadEncodedValue<uint32_t>(uint8_t, uint64_t*); |
| 251 | template bool DwarfMemory::ReadEncodedValue<uint64_t>(uint8_t, uint64_t*); |
Christopher Ferris | d226a51 | 2017-07-14 10:37:19 -0700 | [diff] [blame] | 252 | |
| 253 | } // namespace unwindstack |