Saleem Abdulrasool | 675df58 | 2015-04-24 19:39:17 +0000 | [diff] [blame^] | 1 | //===--------------------------- DwarfParser.hpp --------------------------===// |
| 2 | // |
| 3 | // The LLVM Compiler Infrastructure |
| 4 | // |
| 5 | // This file is dual licensed under the MIT and the University of Illinois Open |
| 6 | // Source Licenses. See LICENSE.TXT for details. |
| 7 | // |
| 8 | // |
| 9 | // Parses DWARF CFIs (FDEs and CIEs). |
| 10 | // |
| 11 | //===----------------------------------------------------------------------===// |
| 12 | |
| 13 | #ifndef __DWARF_PARSER_HPP__ |
| 14 | #define __DWARF_PARSER_HPP__ |
| 15 | |
| 16 | #include <inttypes.h> |
| 17 | #include <stdint.h> |
| 18 | #include <stdio.h> |
| 19 | #include <stdlib.h> |
| 20 | |
| 21 | #include <vector> |
| 22 | |
| 23 | #include "libunwind.h" |
| 24 | #include "dwarf2.h" |
| 25 | |
| 26 | #include "AddressSpace.hpp" |
| 27 | |
| 28 | namespace libunwind { |
| 29 | |
| 30 | /// CFI_Parser does basic parsing of a CFI (Call Frame Information) records. |
| 31 | /// See Dwarf Spec for details: |
| 32 | /// http://refspecs.linuxbase.org/LSB_3.1.0/LSB-Core-generic/LSB-Core-generic/ehframechpt.html |
| 33 | /// |
| 34 | template <typename A> |
| 35 | class CFI_Parser { |
| 36 | public: |
| 37 | typedef typename A::pint_t pint_t; |
| 38 | |
| 39 | /// Information encoded in a CIE (Common Information Entry) |
| 40 | struct CIE_Info { |
| 41 | pint_t cieStart; |
| 42 | pint_t cieLength; |
| 43 | pint_t cieInstructions; |
| 44 | uint8_t pointerEncoding; |
| 45 | uint8_t lsdaEncoding; |
| 46 | uint8_t personalityEncoding; |
| 47 | uint8_t personalityOffsetInCIE; |
| 48 | pint_t personality; |
| 49 | uint32_t codeAlignFactor; |
| 50 | int dataAlignFactor; |
| 51 | bool isSignalFrame; |
| 52 | bool fdesHaveAugmentationData; |
| 53 | uint8_t returnAddressRegister; |
| 54 | }; |
| 55 | |
| 56 | /// Information about an FDE (Frame Description Entry) |
| 57 | struct FDE_Info { |
| 58 | pint_t fdeStart; |
| 59 | pint_t fdeLength; |
| 60 | pint_t fdeInstructions; |
| 61 | pint_t pcStart; |
| 62 | pint_t pcEnd; |
| 63 | pint_t lsda; |
| 64 | }; |
| 65 | |
| 66 | enum { |
| 67 | kMaxRegisterNumber = 120 |
| 68 | }; |
| 69 | enum RegisterSavedWhere { |
| 70 | kRegisterUnused, |
| 71 | kRegisterInCFA, |
| 72 | kRegisterOffsetFromCFA, |
| 73 | kRegisterInRegister, |
| 74 | kRegisterAtExpression, |
| 75 | kRegisterIsExpression |
| 76 | }; |
| 77 | struct RegisterLocation { |
| 78 | RegisterSavedWhere location; |
| 79 | int64_t value; |
| 80 | }; |
| 81 | /// Information about a frame layout and registers saved determined |
| 82 | /// by "running" the dwarf FDE "instructions" |
| 83 | struct PrologInfo { |
| 84 | uint32_t cfaRegister; |
| 85 | int32_t cfaRegisterOffset; // CFA = (cfaRegister)+cfaRegisterOffset |
| 86 | int64_t cfaExpression; // CFA = expression |
| 87 | uint32_t spExtraArgSize; |
| 88 | uint32_t codeOffsetAtStackDecrement; |
| 89 | bool registersInOtherRegisters; |
| 90 | bool sameValueUsed; |
| 91 | RegisterLocation savedRegisters[kMaxRegisterNumber]; |
| 92 | }; |
| 93 | |
| 94 | struct PrologInfoStackEntry { |
| 95 | PrologInfoStackEntry(PrologInfoStackEntry *n, const PrologInfo &i) |
| 96 | : next(n), info(i) {} |
| 97 | PrologInfoStackEntry *next; |
| 98 | PrologInfo info; |
| 99 | }; |
| 100 | |
| 101 | static bool findFDE(A &addressSpace, pint_t pc, pint_t ehSectionStart, |
| 102 | uint32_t sectionLength, pint_t fdeHint, FDE_Info *fdeInfo, |
| 103 | CIE_Info *cieInfo); |
| 104 | static const char *decodeFDE(A &addressSpace, pint_t fdeStart, |
| 105 | FDE_Info *fdeInfo, CIE_Info *cieInfo); |
| 106 | static bool parseFDEInstructions(A &addressSpace, const FDE_Info &fdeInfo, |
| 107 | const CIE_Info &cieInfo, pint_t upToPC, |
| 108 | PrologInfo *results); |
| 109 | |
| 110 | static const char *parseCIE(A &addressSpace, pint_t cie, CIE_Info *cieInfo); |
| 111 | |
| 112 | private: |
| 113 | static bool parseInstructions(A &addressSpace, pint_t instructions, |
| 114 | pint_t instructionsEnd, const CIE_Info &cieInfo, |
| 115 | pint_t pcoffset, |
| 116 | PrologInfoStackEntry *&rememberStack, |
| 117 | PrologInfo *results); |
| 118 | }; |
| 119 | |
| 120 | /// Parse a FDE into a CIE_Info and an FDE_Info |
| 121 | template <typename A> |
| 122 | const char *CFI_Parser<A>::decodeFDE(A &addressSpace, pint_t fdeStart, |
| 123 | FDE_Info *fdeInfo, CIE_Info *cieInfo) { |
| 124 | pint_t p = fdeStart; |
| 125 | pint_t cfiLength = (pint_t)addressSpace.get32(p); |
| 126 | p += 4; |
| 127 | if (cfiLength == 0xffffffff) { |
| 128 | // 0xffffffff means length is really next 8 bytes |
| 129 | cfiLength = (pint_t)addressSpace.get64(p); |
| 130 | p += 8; |
| 131 | } |
| 132 | if (cfiLength == 0) |
| 133 | return "FDE has zero length"; // end marker |
| 134 | uint32_t ciePointer = addressSpace.get32(p); |
| 135 | if (ciePointer == 0) |
| 136 | return "FDE is really a CIE"; // this is a CIE not an FDE |
| 137 | pint_t nextCFI = p + cfiLength; |
| 138 | pint_t cieStart = p - ciePointer; |
| 139 | const char *err = parseCIE(addressSpace, cieStart, cieInfo); |
| 140 | if (err != NULL) |
| 141 | return err; |
| 142 | p += 4; |
| 143 | // parse pc begin and range |
| 144 | pint_t pcStart = |
| 145 | addressSpace.getEncodedP(p, nextCFI, cieInfo->pointerEncoding); |
| 146 | pint_t pcRange = |
| 147 | addressSpace.getEncodedP(p, nextCFI, cieInfo->pointerEncoding & 0x0F); |
| 148 | // parse rest of info |
| 149 | fdeInfo->lsda = 0; |
| 150 | // check for augmentation length |
| 151 | if (cieInfo->fdesHaveAugmentationData) { |
| 152 | pint_t augLen = (pint_t)addressSpace.getULEB128(p, nextCFI); |
| 153 | pint_t endOfAug = p + augLen; |
| 154 | if (cieInfo->lsdaEncoding != DW_EH_PE_omit) { |
| 155 | // peek at value (without indirection). Zero means no lsda |
| 156 | pint_t lsdaStart = p; |
| 157 | if (addressSpace.getEncodedP(p, nextCFI, cieInfo->lsdaEncoding & 0x0F) != |
| 158 | 0) { |
| 159 | // reset pointer and re-parse lsda address |
| 160 | p = lsdaStart; |
| 161 | fdeInfo->lsda = |
| 162 | addressSpace.getEncodedP(p, nextCFI, cieInfo->lsdaEncoding); |
| 163 | } |
| 164 | } |
| 165 | p = endOfAug; |
| 166 | } |
| 167 | fdeInfo->fdeStart = fdeStart; |
| 168 | fdeInfo->fdeLength = nextCFI - fdeStart; |
| 169 | fdeInfo->fdeInstructions = p; |
| 170 | fdeInfo->pcStart = pcStart; |
| 171 | fdeInfo->pcEnd = pcStart + pcRange; |
| 172 | return NULL; // success |
| 173 | } |
| 174 | |
| 175 | /// Scan an eh_frame section to find an FDE for a pc |
| 176 | template <typename A> |
| 177 | bool CFI_Parser<A>::findFDE(A &addressSpace, pint_t pc, pint_t ehSectionStart, |
| 178 | uint32_t sectionLength, pint_t fdeHint, |
| 179 | FDE_Info *fdeInfo, CIE_Info *cieInfo) { |
| 180 | //fprintf(stderr, "findFDE(0x%llX)\n", (long long)pc); |
| 181 | pint_t p = (fdeHint != 0) ? fdeHint : ehSectionStart; |
| 182 | const pint_t ehSectionEnd = p + sectionLength; |
| 183 | while (p < ehSectionEnd) { |
| 184 | pint_t currentCFI = p; |
| 185 | //fprintf(stderr, "findFDE() CFI at 0x%llX\n", (long long)p); |
| 186 | pint_t cfiLength = addressSpace.get32(p); |
| 187 | p += 4; |
| 188 | if (cfiLength == 0xffffffff) { |
| 189 | // 0xffffffff means length is really next 8 bytes |
| 190 | cfiLength = (pint_t)addressSpace.get64(p); |
| 191 | p += 8; |
| 192 | } |
| 193 | if (cfiLength == 0) |
| 194 | return false; // end marker |
| 195 | uint32_t id = addressSpace.get32(p); |
| 196 | if (id == 0) { |
| 197 | // skip over CIEs |
| 198 | p += cfiLength; |
| 199 | } else { |
| 200 | // process FDE to see if it covers pc |
| 201 | pint_t nextCFI = p + cfiLength; |
| 202 | uint32_t ciePointer = addressSpace.get32(p); |
| 203 | pint_t cieStart = p - ciePointer; |
| 204 | // validate pointer to CIE is within section |
| 205 | if ((ehSectionStart <= cieStart) && (cieStart < ehSectionEnd)) { |
| 206 | if (parseCIE(addressSpace, cieStart, cieInfo) == NULL) { |
| 207 | p += 4; |
| 208 | // parse pc begin and range |
| 209 | pint_t pcStart = |
| 210 | addressSpace.getEncodedP(p, nextCFI, cieInfo->pointerEncoding); |
| 211 | pint_t pcRange = addressSpace.getEncodedP( |
| 212 | p, nextCFI, cieInfo->pointerEncoding & 0x0F); |
| 213 | // test if pc is within the function this FDE covers |
| 214 | if ((pcStart < pc) && (pc <= pcStart + pcRange)) { |
| 215 | // parse rest of info |
| 216 | fdeInfo->lsda = 0; |
| 217 | // check for augmentation length |
| 218 | if (cieInfo->fdesHaveAugmentationData) { |
| 219 | pint_t augLen = (pint_t)addressSpace.getULEB128(p, nextCFI); |
| 220 | pint_t endOfAug = p + augLen; |
| 221 | if (cieInfo->lsdaEncoding != DW_EH_PE_omit) { |
| 222 | // peek at value (without indirection). Zero means no lsda |
| 223 | pint_t lsdaStart = p; |
| 224 | if (addressSpace.getEncodedP( |
| 225 | p, nextCFI, cieInfo->lsdaEncoding & 0x0F) != 0) { |
| 226 | // reset pointer and re-parse lsda address |
| 227 | p = lsdaStart; |
| 228 | fdeInfo->lsda = addressSpace |
| 229 | .getEncodedP(p, nextCFI, cieInfo->lsdaEncoding); |
| 230 | } |
| 231 | } |
| 232 | p = endOfAug; |
| 233 | } |
| 234 | fdeInfo->fdeStart = currentCFI; |
| 235 | fdeInfo->fdeLength = nextCFI - currentCFI; |
| 236 | fdeInfo->fdeInstructions = p; |
| 237 | fdeInfo->pcStart = pcStart; |
| 238 | fdeInfo->pcEnd = pcStart + pcRange; |
| 239 | return true; |
| 240 | } else { |
| 241 | // pc is not in begin/range, skip this FDE |
| 242 | } |
| 243 | } else { |
| 244 | // malformed CIE, now augmentation describing pc range encoding |
| 245 | } |
| 246 | } else { |
| 247 | // malformed FDE. CIE is bad |
| 248 | } |
| 249 | p = nextCFI; |
| 250 | } |
| 251 | } |
| 252 | return false; |
| 253 | } |
| 254 | |
| 255 | /// Extract info from a CIE |
| 256 | template <typename A> |
| 257 | const char *CFI_Parser<A>::parseCIE(A &addressSpace, pint_t cie, |
| 258 | CIE_Info *cieInfo) { |
| 259 | cieInfo->pointerEncoding = 0; |
| 260 | cieInfo->lsdaEncoding = DW_EH_PE_omit; |
| 261 | cieInfo->personalityEncoding = 0; |
| 262 | cieInfo->personalityOffsetInCIE = 0; |
| 263 | cieInfo->personality = 0; |
| 264 | cieInfo->codeAlignFactor = 0; |
| 265 | cieInfo->dataAlignFactor = 0; |
| 266 | cieInfo->isSignalFrame = false; |
| 267 | cieInfo->fdesHaveAugmentationData = false; |
| 268 | cieInfo->cieStart = cie; |
| 269 | pint_t p = cie; |
| 270 | pint_t cieLength = (pint_t)addressSpace.get32(p); |
| 271 | p += 4; |
| 272 | pint_t cieContentEnd = p + cieLength; |
| 273 | if (cieLength == 0xffffffff) { |
| 274 | // 0xffffffff means length is really next 8 bytes |
| 275 | cieLength = (pint_t)addressSpace.get64(p); |
| 276 | p += 8; |
| 277 | cieContentEnd = p + cieLength; |
| 278 | } |
| 279 | if (cieLength == 0) |
| 280 | return NULL; |
| 281 | // CIE ID is always 0 |
| 282 | if (addressSpace.get32(p) != 0) |
| 283 | return "CIE ID is not zero"; |
| 284 | p += 4; |
| 285 | // Version is always 1 or 3 |
| 286 | uint8_t version = addressSpace.get8(p); |
| 287 | if ((version != 1) && (version != 3)) |
| 288 | return "CIE version is not 1 or 3"; |
| 289 | ++p; |
| 290 | // save start of augmentation string and find end |
| 291 | pint_t strStart = p; |
| 292 | while (addressSpace.get8(p) != 0) |
| 293 | ++p; |
| 294 | ++p; |
| 295 | // parse code aligment factor |
| 296 | cieInfo->codeAlignFactor = (uint32_t)addressSpace.getULEB128(p, cieContentEnd); |
| 297 | // parse data alignment factor |
| 298 | cieInfo->dataAlignFactor = (int)addressSpace.getSLEB128(p, cieContentEnd); |
| 299 | // parse return address register |
| 300 | uint64_t raReg = addressSpace.getULEB128(p, cieContentEnd); |
| 301 | assert(raReg < 255 && "return address register too large"); |
| 302 | cieInfo->returnAddressRegister = (uint8_t)raReg; |
| 303 | // parse augmentation data based on augmentation string |
| 304 | const char *result = NULL; |
| 305 | if (addressSpace.get8(strStart) == 'z') { |
| 306 | // parse augmentation data length |
| 307 | addressSpace.getULEB128(p, cieContentEnd); |
| 308 | for (pint_t s = strStart; addressSpace.get8(s) != '\0'; ++s) { |
| 309 | switch (addressSpace.get8(s)) { |
| 310 | case 'z': |
| 311 | cieInfo->fdesHaveAugmentationData = true; |
| 312 | break; |
| 313 | case 'P': |
| 314 | cieInfo->personalityEncoding = addressSpace.get8(p); |
| 315 | ++p; |
| 316 | cieInfo->personalityOffsetInCIE = (uint8_t)(p - cie); |
| 317 | cieInfo->personality = addressSpace |
| 318 | .getEncodedP(p, cieContentEnd, cieInfo->personalityEncoding); |
| 319 | break; |
| 320 | case 'L': |
| 321 | cieInfo->lsdaEncoding = addressSpace.get8(p); |
| 322 | ++p; |
| 323 | break; |
| 324 | case 'R': |
| 325 | cieInfo->pointerEncoding = addressSpace.get8(p); |
| 326 | ++p; |
| 327 | break; |
| 328 | case 'S': |
| 329 | cieInfo->isSignalFrame = true; |
| 330 | break; |
| 331 | default: |
| 332 | // ignore unknown letters |
| 333 | break; |
| 334 | } |
| 335 | } |
| 336 | } |
| 337 | cieInfo->cieLength = cieContentEnd - cieInfo->cieStart; |
| 338 | cieInfo->cieInstructions = p; |
| 339 | return result; |
| 340 | } |
| 341 | |
| 342 | |
| 343 | /// "run" the dwarf instructions and create the abstact PrologInfo for an FDE |
| 344 | template <typename A> |
| 345 | bool CFI_Parser<A>::parseFDEInstructions(A &addressSpace, |
| 346 | const FDE_Info &fdeInfo, |
| 347 | const CIE_Info &cieInfo, pint_t upToPC, |
| 348 | PrologInfo *results) { |
| 349 | // clear results |
| 350 | memset(results, '\0', sizeof(PrologInfo)); |
| 351 | PrologInfoStackEntry *rememberStack = NULL; |
| 352 | |
| 353 | // parse CIE then FDE instructions |
| 354 | return parseInstructions(addressSpace, cieInfo.cieInstructions, |
| 355 | cieInfo.cieStart + cieInfo.cieLength, cieInfo, |
| 356 | (pint_t)(-1), rememberStack, results) && |
| 357 | parseInstructions(addressSpace, fdeInfo.fdeInstructions, |
| 358 | fdeInfo.fdeStart + fdeInfo.fdeLength, cieInfo, |
| 359 | upToPC - fdeInfo.pcStart, rememberStack, results); |
| 360 | } |
| 361 | |
| 362 | /// "run" the dwarf instructions |
| 363 | template <typename A> |
| 364 | bool CFI_Parser<A>::parseInstructions(A &addressSpace, pint_t instructions, |
| 365 | pint_t instructionsEnd, |
| 366 | const CIE_Info &cieInfo, pint_t pcoffset, |
| 367 | PrologInfoStackEntry *&rememberStack, |
| 368 | PrologInfo *results) { |
| 369 | const bool logDwarf = false; |
| 370 | pint_t p = instructions; |
| 371 | pint_t codeOffset = 0; |
| 372 | PrologInfo initialState = *results; |
| 373 | if (logDwarf) |
| 374 | fprintf(stderr, "parseInstructions(instructions=0x%0" PRIx64 ")\n", |
| 375 | (uint64_t)instructionsEnd); |
| 376 | |
| 377 | // see Dwarf Spec, section 6.4.2 for details on unwind opcodes |
| 378 | while ((p < instructionsEnd) && (codeOffset < pcoffset)) { |
| 379 | uint64_t reg; |
| 380 | uint64_t reg2; |
| 381 | int64_t offset; |
| 382 | uint64_t length; |
| 383 | uint8_t opcode = addressSpace.get8(p); |
| 384 | uint8_t operand; |
| 385 | PrologInfoStackEntry *entry; |
| 386 | ++p; |
| 387 | switch (opcode) { |
| 388 | case DW_CFA_nop: |
| 389 | if (logDwarf) |
| 390 | fprintf(stderr, "DW_CFA_nop\n"); |
| 391 | break; |
| 392 | case DW_CFA_set_loc: |
| 393 | codeOffset = |
| 394 | addressSpace.getEncodedP(p, instructionsEnd, cieInfo.pointerEncoding); |
| 395 | if (logDwarf) |
| 396 | fprintf(stderr, "DW_CFA_set_loc\n"); |
| 397 | break; |
| 398 | case DW_CFA_advance_loc1: |
| 399 | codeOffset += (addressSpace.get8(p) * cieInfo.codeAlignFactor); |
| 400 | p += 1; |
| 401 | if (logDwarf) |
| 402 | fprintf(stderr, "DW_CFA_advance_loc1: new offset=%" PRIu64 "\n", |
| 403 | (uint64_t)codeOffset); |
| 404 | break; |
| 405 | case DW_CFA_advance_loc2: |
| 406 | codeOffset += (addressSpace.get16(p) * cieInfo.codeAlignFactor); |
| 407 | p += 2; |
| 408 | if (logDwarf) |
| 409 | fprintf(stderr, "DW_CFA_advance_loc2: new offset=%" PRIu64 "\n", |
| 410 | (uint64_t)codeOffset); |
| 411 | break; |
| 412 | case DW_CFA_advance_loc4: |
| 413 | codeOffset += (addressSpace.get32(p) * cieInfo.codeAlignFactor); |
| 414 | p += 4; |
| 415 | if (logDwarf) |
| 416 | fprintf(stderr, "DW_CFA_advance_loc4: new offset=%" PRIu64 "\n", |
| 417 | (uint64_t)codeOffset); |
| 418 | break; |
| 419 | case DW_CFA_offset_extended: |
| 420 | reg = addressSpace.getULEB128(p, instructionsEnd); |
| 421 | offset = (int64_t)addressSpace.getULEB128(p, instructionsEnd) |
| 422 | * cieInfo.dataAlignFactor; |
| 423 | if (reg > kMaxRegisterNumber) { |
| 424 | fprintf(stderr, |
| 425 | "malformed DW_CFA_offset_extended dwarf unwind, reg too big\n"); |
| 426 | return false; |
| 427 | } |
| 428 | results->savedRegisters[reg].location = kRegisterInCFA; |
| 429 | results->savedRegisters[reg].value = offset; |
| 430 | if (logDwarf) |
| 431 | fprintf(stderr, |
| 432 | "DW_CFA_offset_extended(reg=%" PRIu64 ", offset=%" PRId64 ")\n", |
| 433 | reg, offset); |
| 434 | break; |
| 435 | case DW_CFA_restore_extended: |
| 436 | reg = addressSpace.getULEB128(p, instructionsEnd); |
| 437 | ; |
| 438 | if (reg > kMaxRegisterNumber) { |
| 439 | fprintf( |
| 440 | stderr, |
| 441 | "malformed DW_CFA_restore_extended dwarf unwind, reg too big\n"); |
| 442 | return false; |
| 443 | } |
| 444 | results->savedRegisters[reg] = initialState.savedRegisters[reg]; |
| 445 | if (logDwarf) |
| 446 | fprintf(stderr, "DW_CFA_restore_extended(reg=%" PRIu64 ")\n", reg); |
| 447 | break; |
| 448 | case DW_CFA_undefined: |
| 449 | reg = addressSpace.getULEB128(p, instructionsEnd); |
| 450 | if (reg > kMaxRegisterNumber) { |
| 451 | fprintf(stderr, |
| 452 | "malformed DW_CFA_undefined dwarf unwind, reg too big\n"); |
| 453 | return false; |
| 454 | } |
| 455 | results->savedRegisters[reg].location = kRegisterUnused; |
| 456 | if (logDwarf) |
| 457 | fprintf(stderr, "DW_CFA_undefined(reg=%" PRIu64 ")\n", reg); |
| 458 | break; |
| 459 | case DW_CFA_same_value: |
| 460 | reg = addressSpace.getULEB128(p, instructionsEnd); |
| 461 | if (reg > kMaxRegisterNumber) { |
| 462 | fprintf(stderr, |
| 463 | "malformed DW_CFA_same_value dwarf unwind, reg too big\n"); |
| 464 | return false; |
| 465 | } |
| 466 | // <rdar://problem/8456377> DW_CFA_same_value unsupported |
| 467 | // "same value" means register was stored in frame, but its current |
| 468 | // value has not changed, so no need to restore from frame. |
| 469 | // We model this as if the register was never saved. |
| 470 | results->savedRegisters[reg].location = kRegisterUnused; |
| 471 | // set flag to disable conversion to compact unwind |
| 472 | results->sameValueUsed = true; |
| 473 | if (logDwarf) |
| 474 | fprintf(stderr, "DW_CFA_same_value(reg=%" PRIu64 ")\n", reg); |
| 475 | break; |
| 476 | case DW_CFA_register: |
| 477 | reg = addressSpace.getULEB128(p, instructionsEnd); |
| 478 | reg2 = addressSpace.getULEB128(p, instructionsEnd); |
| 479 | if (reg > kMaxRegisterNumber) { |
| 480 | fprintf(stderr, |
| 481 | "malformed DW_CFA_register dwarf unwind, reg too big\n"); |
| 482 | return false; |
| 483 | } |
| 484 | if (reg2 > kMaxRegisterNumber) { |
| 485 | fprintf(stderr, |
| 486 | "malformed DW_CFA_register dwarf unwind, reg2 too big\n"); |
| 487 | return false; |
| 488 | } |
| 489 | results->savedRegisters[reg].location = kRegisterInRegister; |
| 490 | results->savedRegisters[reg].value = (int64_t)reg2; |
| 491 | // set flag to disable conversion to compact unwind |
| 492 | results->registersInOtherRegisters = true; |
| 493 | if (logDwarf) |
| 494 | fprintf(stderr, "DW_CFA_register(reg=%" PRIu64 ", reg2=%" PRIu64 ")\n", |
| 495 | reg, reg2); |
| 496 | break; |
| 497 | case DW_CFA_remember_state: |
| 498 | // avoid operator new, because that would be an upward dependency |
| 499 | entry = (PrologInfoStackEntry *)malloc(sizeof(PrologInfoStackEntry)); |
| 500 | if (entry != NULL) { |
| 501 | entry->next = rememberStack; |
| 502 | entry->info = *results; |
| 503 | rememberStack = entry; |
| 504 | } else { |
| 505 | return false; |
| 506 | } |
| 507 | if (logDwarf) |
| 508 | fprintf(stderr, "DW_CFA_remember_state\n"); |
| 509 | break; |
| 510 | case DW_CFA_restore_state: |
| 511 | if (rememberStack != NULL) { |
| 512 | PrologInfoStackEntry *top = rememberStack; |
| 513 | *results = top->info; |
| 514 | rememberStack = top->next; |
| 515 | free((char *)top); |
| 516 | } else { |
| 517 | return false; |
| 518 | } |
| 519 | if (logDwarf) |
| 520 | fprintf(stderr, "DW_CFA_restore_state\n"); |
| 521 | break; |
| 522 | case DW_CFA_def_cfa: |
| 523 | reg = addressSpace.getULEB128(p, instructionsEnd); |
| 524 | offset = (int64_t)addressSpace.getULEB128(p, instructionsEnd); |
| 525 | if (reg > kMaxRegisterNumber) { |
| 526 | fprintf(stderr, "malformed DW_CFA_def_cfa dwarf unwind, reg too big\n"); |
| 527 | return false; |
| 528 | } |
| 529 | results->cfaRegister = (uint32_t)reg; |
| 530 | results->cfaRegisterOffset = (int32_t)offset; |
| 531 | if (logDwarf) |
| 532 | fprintf(stderr, "DW_CFA_def_cfa(reg=%" PRIu64 ", offset=%" PRIu64 ")\n", |
| 533 | reg, offset); |
| 534 | break; |
| 535 | case DW_CFA_def_cfa_register: |
| 536 | reg = addressSpace.getULEB128(p, instructionsEnd); |
| 537 | if (reg > kMaxRegisterNumber) { |
| 538 | fprintf( |
| 539 | stderr, |
| 540 | "malformed DW_CFA_def_cfa_register dwarf unwind, reg too big\n"); |
| 541 | return false; |
| 542 | } |
| 543 | results->cfaRegister = (uint32_t)reg; |
| 544 | if (logDwarf) |
| 545 | fprintf(stderr, "DW_CFA_def_cfa_register(%" PRIu64 ")\n", reg); |
| 546 | break; |
| 547 | case DW_CFA_def_cfa_offset: |
| 548 | results->cfaRegisterOffset = (int32_t) |
| 549 | addressSpace.getULEB128(p, instructionsEnd); |
| 550 | results->codeOffsetAtStackDecrement = (uint32_t)codeOffset; |
| 551 | if (logDwarf) |
| 552 | fprintf(stderr, "DW_CFA_def_cfa_offset(%d)\n", |
| 553 | results->cfaRegisterOffset); |
| 554 | break; |
| 555 | case DW_CFA_def_cfa_expression: |
| 556 | results->cfaRegister = 0; |
| 557 | results->cfaExpression = (int64_t)p; |
| 558 | length = addressSpace.getULEB128(p, instructionsEnd); |
| 559 | p += length; |
| 560 | if (logDwarf) |
| 561 | fprintf(stderr, "DW_CFA_def_cfa_expression(expression=0x%" PRIx64 |
| 562 | ", length=%" PRIu64 ")\n", |
| 563 | results->cfaExpression, length); |
| 564 | break; |
| 565 | case DW_CFA_expression: |
| 566 | reg = addressSpace.getULEB128(p, instructionsEnd); |
| 567 | if (reg > kMaxRegisterNumber) { |
| 568 | fprintf(stderr, |
| 569 | "malformed DW_CFA_expression dwarf unwind, reg too big\n"); |
| 570 | return false; |
| 571 | } |
| 572 | results->savedRegisters[reg].location = kRegisterAtExpression; |
| 573 | results->savedRegisters[reg].value = (int64_t)p; |
| 574 | length = addressSpace.getULEB128(p, instructionsEnd); |
| 575 | p += length; |
| 576 | if (logDwarf) |
| 577 | fprintf(stderr, "DW_CFA_expression(reg=%" PRIu64 |
| 578 | ", expression=0x%" PRIx64 ", length=%" PRIu64 ")\n", |
| 579 | reg, results->savedRegisters[reg].value, length); |
| 580 | break; |
| 581 | case DW_CFA_offset_extended_sf: |
| 582 | reg = addressSpace.getULEB128(p, instructionsEnd); |
| 583 | if (reg > kMaxRegisterNumber) { |
| 584 | fprintf( |
| 585 | stderr, |
| 586 | "malformed DW_CFA_offset_extended_sf dwarf unwind, reg too big\n"); |
| 587 | return false; |
| 588 | } |
| 589 | offset = |
| 590 | addressSpace.getSLEB128(p, instructionsEnd) * cieInfo.dataAlignFactor; |
| 591 | results->savedRegisters[reg].location = kRegisterInCFA; |
| 592 | results->savedRegisters[reg].value = offset; |
| 593 | if (logDwarf) |
| 594 | fprintf(stderr, "DW_CFA_offset_extended_sf(reg=%" PRIu64 |
| 595 | ", offset=%" PRId64 ")\n", |
| 596 | reg, offset); |
| 597 | break; |
| 598 | case DW_CFA_def_cfa_sf: |
| 599 | reg = addressSpace.getULEB128(p, instructionsEnd); |
| 600 | offset = |
| 601 | addressSpace.getSLEB128(p, instructionsEnd) * cieInfo.dataAlignFactor; |
| 602 | if (reg > kMaxRegisterNumber) { |
| 603 | fprintf(stderr, |
| 604 | "malformed DW_CFA_def_cfa_sf dwarf unwind, reg too big\n"); |
| 605 | return false; |
| 606 | } |
| 607 | results->cfaRegister = (uint32_t)reg; |
| 608 | results->cfaRegisterOffset = (int32_t)offset; |
| 609 | if (logDwarf) |
| 610 | fprintf(stderr, |
| 611 | "DW_CFA_def_cfa_sf(reg=%" PRIu64 ", offset=%" PRId64 ")\n", reg, |
| 612 | offset); |
| 613 | break; |
| 614 | case DW_CFA_def_cfa_offset_sf: |
| 615 | results->cfaRegisterOffset = (int32_t) |
| 616 | (addressSpace.getSLEB128(p, instructionsEnd) * cieInfo.dataAlignFactor); |
| 617 | results->codeOffsetAtStackDecrement = (uint32_t)codeOffset; |
| 618 | if (logDwarf) |
| 619 | fprintf(stderr, "DW_CFA_def_cfa_offset_sf(%d)\n", |
| 620 | results->cfaRegisterOffset); |
| 621 | break; |
| 622 | case DW_CFA_val_offset: |
| 623 | reg = addressSpace.getULEB128(p, instructionsEnd); |
| 624 | offset = (int64_t)addressSpace.getULEB128(p, instructionsEnd) |
| 625 | * cieInfo.dataAlignFactor; |
| 626 | results->savedRegisters[reg].location = kRegisterOffsetFromCFA; |
| 627 | results->savedRegisters[reg].value = offset; |
| 628 | if (logDwarf) |
| 629 | fprintf(stderr, |
| 630 | "DW_CFA_val_offset(reg=%" PRIu64 ", offset=%" PRId64 "\n", reg, |
| 631 | offset); |
| 632 | break; |
| 633 | case DW_CFA_val_offset_sf: |
| 634 | reg = addressSpace.getULEB128(p, instructionsEnd); |
| 635 | if (reg > kMaxRegisterNumber) { |
| 636 | fprintf(stderr, |
| 637 | "malformed DW_CFA_val_offset_sf dwarf unwind, reg too big\n"); |
| 638 | return false; |
| 639 | } |
| 640 | offset = |
| 641 | addressSpace.getSLEB128(p, instructionsEnd) * cieInfo.dataAlignFactor; |
| 642 | results->savedRegisters[reg].location = kRegisterOffsetFromCFA; |
| 643 | results->savedRegisters[reg].value = offset; |
| 644 | if (logDwarf) |
| 645 | fprintf(stderr, |
| 646 | "DW_CFA_val_offset_sf(reg=%" PRIu64 ", offset=%" PRId64 "\n", |
| 647 | reg, offset); |
| 648 | break; |
| 649 | case DW_CFA_val_expression: |
| 650 | reg = addressSpace.getULEB128(p, instructionsEnd); |
| 651 | if (reg > kMaxRegisterNumber) { |
| 652 | fprintf(stderr, |
| 653 | "malformed DW_CFA_val_expression dwarf unwind, reg too big\n"); |
| 654 | return false; |
| 655 | } |
| 656 | results->savedRegisters[reg].location = kRegisterIsExpression; |
| 657 | results->savedRegisters[reg].value = (int64_t)p; |
| 658 | length = addressSpace.getULEB128(p, instructionsEnd); |
| 659 | p += length; |
| 660 | if (logDwarf) |
| 661 | fprintf(stderr, "DW_CFA_val_expression(reg=%" PRIu64 |
| 662 | ", expression=0x%" PRIx64 ", length=%" PRIu64 ")\n", |
| 663 | reg, results->savedRegisters[reg].value, length); |
| 664 | break; |
| 665 | case DW_CFA_GNU_args_size: |
| 666 | length = addressSpace.getULEB128(p, instructionsEnd); |
| 667 | results->spExtraArgSize = (uint32_t)length; |
| 668 | if (logDwarf) |
| 669 | fprintf(stderr, "DW_CFA_GNU_args_size(%" PRIu64 ")\n", length); |
| 670 | break; |
| 671 | case DW_CFA_GNU_negative_offset_extended: |
| 672 | reg = addressSpace.getULEB128(p, instructionsEnd); |
| 673 | if (reg > kMaxRegisterNumber) { |
| 674 | fprintf(stderr, "malformed DW_CFA_GNU_negative_offset_extended dwarf " |
| 675 | "unwind, reg too big\n"); |
| 676 | return false; |
| 677 | } |
| 678 | offset = (int64_t)addressSpace.getULEB128(p, instructionsEnd) |
| 679 | * cieInfo.dataAlignFactor; |
| 680 | results->savedRegisters[reg].location = kRegisterInCFA; |
| 681 | results->savedRegisters[reg].value = -offset; |
| 682 | if (logDwarf) |
| 683 | fprintf(stderr, "DW_CFA_GNU_negative_offset_extended(%" PRId64 ")\n", |
| 684 | offset); |
| 685 | break; |
| 686 | default: |
| 687 | operand = opcode & 0x3F; |
| 688 | switch (opcode & 0xC0) { |
| 689 | case DW_CFA_offset: |
| 690 | reg = operand; |
| 691 | offset = (int64_t)addressSpace.getULEB128(p, instructionsEnd) |
| 692 | * cieInfo.dataAlignFactor; |
| 693 | results->savedRegisters[reg].location = kRegisterInCFA; |
| 694 | results->savedRegisters[reg].value = offset; |
| 695 | if (logDwarf) |
| 696 | fprintf(stderr, "DW_CFA_offset(reg=%d, offset=%" PRId64 ")\n", |
| 697 | operand, offset); |
| 698 | break; |
| 699 | case DW_CFA_advance_loc: |
| 700 | codeOffset += operand * cieInfo.codeAlignFactor; |
| 701 | if (logDwarf) |
| 702 | fprintf(stderr, "DW_CFA_advance_loc: new offset=%" PRIu64 "\n", |
| 703 | (uint64_t)codeOffset); |
| 704 | break; |
| 705 | case DW_CFA_restore: |
| 706 | reg = operand; |
| 707 | results->savedRegisters[reg] = initialState.savedRegisters[reg]; |
| 708 | if (logDwarf) |
| 709 | fprintf(stderr, "DW_CFA_restore(reg=%" PRIu64 ")\n", reg); |
| 710 | break; |
| 711 | default: |
| 712 | if (logDwarf) |
| 713 | fprintf(stderr, "unknown CFA opcode 0x%02X\n", opcode); |
| 714 | return false; |
| 715 | } |
| 716 | } |
| 717 | } |
| 718 | |
| 719 | return true; |
| 720 | } |
| 721 | |
| 722 | } // namespace libunwind |
| 723 | |
| 724 | #endif // __DWARF_PARSER_HPP__ |