1 //===----------------------------------------------------------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 // 8 // Implements ARM zero-cost C++ exceptions 9 // 10 //===----------------------------------------------------------------------===// 11 12 #include "Unwind-EHABI.h" 13 14 #if defined(_LIBUNWIND_ARM_EHABI) 15 16 #include <inttypes.h> 17 #include <stdbool.h> 18 #include <stdint.h> 19 #include <stdio.h> 20 #include <stdlib.h> 21 #include <string.h> 22 23 #include "config.h" 24 #include "libunwind.h" 25 #include "libunwind_ext.h" 26 #include "unwind.h" 27 28 namespace { 29 30 // Strange order: take words in order, but inside word, take from most to least 31 // signinficant byte. 32 uint8_t getByte(const uint32_t* data, size_t offset) { 33 const uint8_t* byteData = reinterpret_cast<const uint8_t*>(data); 34 #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__ 35 return byteData[(offset & ~(size_t)0x03) + (3 - (offset & (size_t)0x03))]; 36 #elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__ 37 return byteData[offset]; 38 #else 39 #error "Unable to determine endianess" 40 #endif 41 } 42 43 const char* getNextWord(const char* data, uint32_t* out) { 44 *out = *reinterpret_cast<const uint32_t*>(data); 45 return data + 4; 46 } 47 48 const char* getNextNibble(const char* data, uint32_t* out) { 49 *out = *reinterpret_cast<const uint16_t*>(data); 50 return data + 2; 51 } 52 53 struct Descriptor { 54 // See # 9.2 55 typedef enum { 56 SU16 = 0, // Short descriptor, 16-bit entries 57 LU16 = 1, // Long descriptor, 16-bit entries 58 LU32 = 3, // Long descriptor, 32-bit entries 59 RESERVED0 = 4, RESERVED1 = 5, RESERVED2 = 6, RESERVED3 = 7, 60 RESERVED4 = 8, RESERVED5 = 9, RESERVED6 = 10, RESERVED7 = 11, 61 RESERVED8 = 12, RESERVED9 = 13, RESERVED10 = 14, RESERVED11 = 15 62 } Format; 63 64 // See # 9.2 65 typedef enum { 66 CLEANUP = 0x0, 67 FUNC = 0x1, 68 CATCH = 0x2, 69 INVALID = 0x4 70 } Kind; 71 }; 72 73 _Unwind_Reason_Code ProcessDescriptors( 74 _Unwind_State state, 75 _Unwind_Control_Block* ucbp, 76 struct _Unwind_Context* context, 77 Descriptor::Format format, 78 const char* descriptorStart, 79 uint32_t flags) { 80 81 // EHT is inlined in the index using compact form. No descriptors. #5 82 if (flags & 0x1) 83 return _URC_CONTINUE_UNWIND; 84 85 // TODO: We should check the state here, and determine whether we need to 86 // perform phase1 or phase2 unwinding. 87 (void)state; 88 89 const char* descriptor = descriptorStart; 90 uint32_t descriptorWord; 91 getNextWord(descriptor, &descriptorWord); 92 while (descriptorWord) { 93 // Read descriptor based on # 9.2. 94 uint32_t length; 95 uint32_t offset; 96 switch (format) { 97 case Descriptor::LU32: 98 descriptor = getNextWord(descriptor, &length); 99 descriptor = getNextWord(descriptor, &offset); 100 break; 101 case Descriptor::LU16: 102 descriptor = getNextNibble(descriptor, &length); 103 descriptor = getNextNibble(descriptor, &offset); 104 break; 105 default: 106 assert(false); 107 return _URC_FAILURE; 108 } 109 110 // See # 9.2 table for decoding the kind of descriptor. It's a 2-bit value. 111 Descriptor::Kind kind = 112 static_cast<Descriptor::Kind>((length & 0x1) | ((offset & 0x1) << 1)); 113 114 // Clear off flag from last bit. 115 length &= ~1u; 116 offset &= ~1u; 117 uintptr_t scopeStart = ucbp->pr_cache.fnstart + offset; 118 uintptr_t scopeEnd = scopeStart + length; 119 uintptr_t pc = _Unwind_GetIP(context); 120 bool isInScope = (scopeStart <= pc) && (pc < scopeEnd); 121 122 switch (kind) { 123 case Descriptor::CLEANUP: { 124 // TODO(ajwong): Handle cleanup descriptors. 125 break; 126 } 127 case Descriptor::FUNC: { 128 // TODO(ajwong): Handle function descriptors. 129 break; 130 } 131 case Descriptor::CATCH: { 132 // Catch descriptors require gobbling one more word. 133 uint32_t landing_pad; 134 descriptor = getNextWord(descriptor, &landing_pad); 135 136 if (isInScope) { 137 // TODO(ajwong): This is only phase1 compatible logic. Implement 138 // phase2. 139 landing_pad = signExtendPrel31(landing_pad & ~0x80000000); 140 if (landing_pad == 0xffffffff) { 141 return _URC_HANDLER_FOUND; 142 } else if (landing_pad == 0xfffffffe) { 143 return _URC_FAILURE; 144 } else { 145 /* 146 bool is_reference_type = landing_pad & 0x80000000; 147 void* matched_object; 148 if (__cxxabiv1::__cxa_type_match( 149 ucbp, reinterpret_cast<const std::type_info *>(landing_pad), 150 is_reference_type, 151 &matched_object) != __cxxabiv1::ctm_failed) 152 return _URC_HANDLER_FOUND; 153 */ 154 _LIBUNWIND_ABORT("Type matching not implemented"); 155 } 156 } 157 break; 158 } 159 default: 160 _LIBUNWIND_ABORT("Invalid descriptor kind found."); 161 } 162 163 getNextWord(descriptor, &descriptorWord); 164 } 165 166 return _URC_CONTINUE_UNWIND; 167 } 168 169 static _Unwind_Reason_Code unwindOneFrame(_Unwind_State state, 170 _Unwind_Control_Block* ucbp, 171 struct _Unwind_Context* context) { 172 // Read the compact model EHT entry's header # 6.3 173 const uint32_t* unwindingData = ucbp->pr_cache.ehtp; 174 assert((*unwindingData & 0xf0000000) == 0x80000000 && "Must be a compact entry"); 175 Descriptor::Format format = 176 static_cast<Descriptor::Format>((*unwindingData & 0x0f000000) >> 24); 177 178 const char *lsda = 179 reinterpret_cast<const char *>(_Unwind_GetLanguageSpecificData(context)); 180 181 // Handle descriptors before unwinding so they are processed in the context 182 // of the correct stack frame. 183 _Unwind_Reason_Code result = 184 ProcessDescriptors(state, ucbp, context, format, lsda, 185 ucbp->pr_cache.additional); 186 187 if (result != _URC_CONTINUE_UNWIND) 188 return result; 189 190 switch (__unw_step(reinterpret_cast<unw_cursor_t *>(context))) { 191 case UNW_STEP_SUCCESS: 192 return _URC_CONTINUE_UNWIND; 193 case UNW_STEP_END: 194 return _URC_END_OF_STACK; 195 default: 196 return _URC_FAILURE; 197 } 198 } 199 200 // Generates mask discriminator for _Unwind_VRS_Pop, e.g. for _UVRSC_CORE / 201 // _UVRSD_UINT32. 202 uint32_t RegisterMask(uint8_t start, uint8_t count_minus_one) { 203 return ((1U << (count_minus_one + 1)) - 1) << start; 204 } 205 206 // Generates mask discriminator for _Unwind_VRS_Pop, e.g. for _UVRSC_VFP / 207 // _UVRSD_DOUBLE. 208 uint32_t RegisterRange(uint8_t start, uint8_t count_minus_one) { 209 return ((uint32_t)start << 16) | ((uint32_t)count_minus_one + 1); 210 } 211 212 } // end anonymous namespace 213 214 /** 215 * Decodes an EHT entry. 216 * 217 * @param data Pointer to EHT. 218 * @param[out] off Offset from return value (in bytes) to begin interpretation. 219 * @param[out] len Number of bytes in unwind code. 220 * @return Pointer to beginning of unwind code. 221 */ 222 extern "C" const uint32_t* 223 decode_eht_entry(const uint32_t* data, size_t* off, size_t* len) { 224 if ((*data & 0x80000000) == 0) { 225 // 6.2: Generic Model 226 // 227 // EHT entry is a prel31 pointing to the PR, followed by data understood 228 // only by the personality routine. Fortunately, all existing assembler 229 // implementations, including GNU assembler, LLVM integrated assembler, 230 // and ARM assembler, assume that the unwind opcodes come after the 231 // personality rountine address. 232 *off = 1; // First byte is size data. 233 *len = (((data[1] >> 24) & 0xff) + 1) * 4; 234 data++; // Skip the first word, which is the prel31 offset. 235 } else { 236 // 6.3: ARM Compact Model 237 // 238 // EHT entries here correspond to the __aeabi_unwind_cpp_pr[012] PRs indeded 239 // by format: 240 Descriptor::Format format = 241 static_cast<Descriptor::Format>((*data & 0x0f000000) >> 24); 242 switch (format) { 243 case Descriptor::SU16: 244 *len = 4; 245 *off = 1; 246 break; 247 case Descriptor::LU16: 248 case Descriptor::LU32: 249 *len = 4 + 4 * ((*data & 0x00ff0000) >> 16); 250 *off = 2; 251 break; 252 default: 253 return nullptr; 254 } 255 } 256 return data; 257 } 258 259 _LIBUNWIND_EXPORT _Unwind_Reason_Code 260 _Unwind_VRS_Interpret(_Unwind_Context *context, const uint32_t *data, 261 size_t offset, size_t len) { 262 bool wrotePC = false; 263 bool finish = false; 264 bool hasReturnAddrAuthCode = false; 265 while (offset < len && !finish) { 266 uint8_t byte = getByte(data, offset++); 267 if ((byte & 0x80) == 0) { 268 uint32_t sp; 269 _Unwind_VRS_Get(context, _UVRSC_CORE, UNW_ARM_SP, _UVRSD_UINT32, &sp); 270 if (byte & 0x40) 271 sp -= (((uint32_t)byte & 0x3f) << 2) + 4; 272 else 273 sp += ((uint32_t)byte << 2) + 4; 274 _Unwind_VRS_Set(context, _UVRSC_CORE, UNW_ARM_SP, _UVRSD_UINT32, &sp); 275 } else { 276 switch (byte & 0xf0) { 277 case 0x80: { 278 if (offset >= len) 279 return _URC_FAILURE; 280 uint32_t registers = 281 (((uint32_t)byte & 0x0f) << 12) | 282 (((uint32_t)getByte(data, offset++)) << 4); 283 if (!registers) 284 return _URC_FAILURE; 285 if (registers & (1 << 15)) 286 wrotePC = true; 287 _Unwind_VRS_Pop(context, _UVRSC_CORE, registers, _UVRSD_UINT32); 288 break; 289 } 290 case 0x90: { 291 uint8_t reg = byte & 0x0f; 292 if (reg == 13 || reg == 15) 293 return _URC_FAILURE; 294 uint32_t sp; 295 _Unwind_VRS_Get(context, _UVRSC_CORE, UNW_ARM_R0 + reg, 296 _UVRSD_UINT32, &sp); 297 _Unwind_VRS_Set(context, _UVRSC_CORE, UNW_ARM_SP, _UVRSD_UINT32, 298 &sp); 299 break; 300 } 301 case 0xa0: { 302 uint32_t registers = RegisterMask(4, byte & 0x07); 303 if (byte & 0x08) 304 registers |= 1 << 14; 305 _Unwind_VRS_Pop(context, _UVRSC_CORE, registers, _UVRSD_UINT32); 306 break; 307 } 308 case 0xb0: { 309 switch (byte) { 310 case 0xb0: 311 finish = true; 312 break; 313 case 0xb1: { 314 if (offset >= len) 315 return _URC_FAILURE; 316 uint8_t registers = getByte(data, offset++); 317 if (registers & 0xf0 || !registers) 318 return _URC_FAILURE; 319 _Unwind_VRS_Pop(context, _UVRSC_CORE, registers, _UVRSD_UINT32); 320 break; 321 } 322 case 0xb2: { 323 uint32_t addend = 0; 324 uint32_t shift = 0; 325 // This decodes a uleb128 value. 326 while (true) { 327 if (offset >= len) 328 return _URC_FAILURE; 329 uint32_t v = getByte(data, offset++); 330 addend |= (v & 0x7f) << shift; 331 if ((v & 0x80) == 0) 332 break; 333 shift += 7; 334 } 335 uint32_t sp; 336 _Unwind_VRS_Get(context, _UVRSC_CORE, UNW_ARM_SP, _UVRSD_UINT32, 337 &sp); 338 sp += 0x204 + (addend << 2); 339 _Unwind_VRS_Set(context, _UVRSC_CORE, UNW_ARM_SP, _UVRSD_UINT32, 340 &sp); 341 break; 342 } 343 case 0xb3: { 344 uint8_t v = getByte(data, offset++); 345 _Unwind_VRS_Pop(context, _UVRSC_VFP, 346 RegisterRange(static_cast<uint8_t>(v >> 4), 347 v & 0x0f), _UVRSD_VFPX); 348 break; 349 } 350 case 0xb4: 351 hasReturnAddrAuthCode = true; 352 _Unwind_VRS_Pop(context, _UVRSC_PSEUDO, 353 0 /* Return Address Auth Code */, _UVRSD_UINT32); 354 break; 355 case 0xb5: 356 case 0xb6: 357 case 0xb7: 358 return _URC_FAILURE; 359 default: 360 _Unwind_VRS_Pop(context, _UVRSC_VFP, 361 RegisterRange(8, byte & 0x07), _UVRSD_VFPX); 362 break; 363 } 364 break; 365 } 366 case 0xc0: { 367 switch (byte) { 368 #if defined(__ARM_WMMX) 369 case 0xc0: 370 case 0xc1: 371 case 0xc2: 372 case 0xc3: 373 case 0xc4: 374 case 0xc5: 375 _Unwind_VRS_Pop(context, _UVRSC_WMMXD, 376 RegisterRange(10, byte & 0x7), _UVRSD_DOUBLE); 377 break; 378 case 0xc6: { 379 uint8_t v = getByte(data, offset++); 380 uint8_t start = static_cast<uint8_t>(v >> 4); 381 uint8_t count_minus_one = v & 0xf; 382 if (start + count_minus_one >= 16) 383 return _URC_FAILURE; 384 _Unwind_VRS_Pop(context, _UVRSC_WMMXD, 385 RegisterRange(start, count_minus_one), 386 _UVRSD_DOUBLE); 387 break; 388 } 389 case 0xc7: { 390 uint8_t v = getByte(data, offset++); 391 if (!v || v & 0xf0) 392 return _URC_FAILURE; 393 _Unwind_VRS_Pop(context, _UVRSC_WMMXC, v, _UVRSD_DOUBLE); 394 break; 395 } 396 #endif 397 case 0xc8: 398 case 0xc9: { 399 uint8_t v = getByte(data, offset++); 400 uint8_t start = 401 static_cast<uint8_t>(((byte == 0xc8) ? 16 : 0) + (v >> 4)); 402 uint8_t count_minus_one = v & 0xf; 403 if (start + count_minus_one >= 32) 404 return _URC_FAILURE; 405 _Unwind_VRS_Pop(context, _UVRSC_VFP, 406 RegisterRange(start, count_minus_one), 407 _UVRSD_DOUBLE); 408 break; 409 } 410 default: 411 return _URC_FAILURE; 412 } 413 break; 414 } 415 case 0xd0: { 416 if (byte & 0x08) 417 return _URC_FAILURE; 418 _Unwind_VRS_Pop(context, _UVRSC_VFP, RegisterRange(8, byte & 0x7), 419 _UVRSD_DOUBLE); 420 break; 421 } 422 default: 423 return _URC_FAILURE; 424 } 425 } 426 } 427 if (!wrotePC) { 428 uint32_t lr; 429 _Unwind_VRS_Get(context, _UVRSC_CORE, UNW_ARM_LR, _UVRSD_UINT32, &lr); 430 #ifdef __ARM_FEATURE_PAUTH 431 if (hasReturnAddrAuthCode) { 432 uint32_t sp; 433 uint32_t pac; 434 _Unwind_VRS_Get(context, _UVRSC_CORE, UNW_ARM_SP, _UVRSD_UINT32, &sp); 435 _Unwind_VRS_Get(context, _UVRSC_PSEUDO, UNW_ARM_RA_AUTH_CODE, 436 _UVRSD_UINT32, &pac); 437 __asm__ __volatile__("autg %0, %1, %2" : : "r"(pac), "r"(lr), "r"(sp) :); 438 } 439 #endif 440 _Unwind_VRS_Set(context, _UVRSC_CORE, UNW_ARM_IP, _UVRSD_UINT32, &lr); 441 } 442 return _URC_CONTINUE_UNWIND; 443 } 444 445 extern "C" _LIBUNWIND_EXPORT _Unwind_Reason_Code 446 __aeabi_unwind_cpp_pr0(_Unwind_State state, _Unwind_Control_Block *ucbp, 447 _Unwind_Context *context) { 448 return unwindOneFrame(state, ucbp, context); 449 } 450 451 extern "C" _LIBUNWIND_EXPORT _Unwind_Reason_Code 452 __aeabi_unwind_cpp_pr1(_Unwind_State state, _Unwind_Control_Block *ucbp, 453 _Unwind_Context *context) { 454 return unwindOneFrame(state, ucbp, context); 455 } 456 457 extern "C" _LIBUNWIND_EXPORT _Unwind_Reason_Code 458 __aeabi_unwind_cpp_pr2(_Unwind_State state, _Unwind_Control_Block *ucbp, 459 _Unwind_Context *context) { 460 return unwindOneFrame(state, ucbp, context); 461 } 462 463 static _Unwind_Reason_Code 464 unwind_phase1(unw_context_t *uc, unw_cursor_t *cursor, _Unwind_Exception *exception_object) { 465 // EHABI #7.3 discusses preserving the VRS in a "temporary VRS" during 466 // phase 1 and then restoring it to the "primary VRS" for phase 2. The 467 // effect is phase 2 doesn't see any of the VRS manipulations from phase 1. 468 // In this implementation, the phases don't share the VRS backing store. 469 // Instead, they are passed the original |uc| and they create a new VRS 470 // from scratch thus achieving the same effect. 471 __unw_init_local(cursor, uc); 472 473 // Walk each frame looking for a place to stop. 474 for (bool handlerNotFound = true; handlerNotFound;) { 475 476 // See if frame has code to run (has personality routine). 477 unw_proc_info_t frameInfo; 478 if (__unw_get_proc_info(cursor, &frameInfo) != UNW_ESUCCESS) { 479 _LIBUNWIND_TRACE_UNWINDING( 480 "unwind_phase1(ex_ojb=%p): __unw_get_proc_info " 481 "failed => _URC_FATAL_PHASE1_ERROR", 482 static_cast<void *>(exception_object)); 483 return _URC_FATAL_PHASE1_ERROR; 484 } 485 486 #ifndef NDEBUG 487 // When tracing, print state information. 488 if (_LIBUNWIND_TRACING_UNWINDING) { 489 char functionBuf[512]; 490 const char *functionName = functionBuf; 491 unw_word_t offset; 492 if ((__unw_get_proc_name(cursor, functionBuf, sizeof(functionBuf), 493 &offset) != UNW_ESUCCESS) || 494 (frameInfo.start_ip + offset > frameInfo.end_ip)) 495 functionName = ".anonymous."; 496 unw_word_t pc; 497 __unw_get_reg(cursor, UNW_REG_IP, &pc); 498 _LIBUNWIND_TRACE_UNWINDING( 499 "unwind_phase1(ex_ojb=%p): pc=0x%" PRIxPTR ", start_ip=0x%" PRIxPTR ", func=%s, " 500 "lsda=0x%" PRIxPTR ", personality=0x%" PRIxPTR, 501 static_cast<void *>(exception_object), pc, 502 frameInfo.start_ip, functionName, 503 frameInfo.lsda, frameInfo.handler); 504 } 505 #endif 506 507 // If there is a personality routine, ask it if it will want to stop at 508 // this frame. 509 if (frameInfo.handler != 0) { 510 _Unwind_Personality_Fn p = 511 (_Unwind_Personality_Fn)(long)(frameInfo.handler); 512 _LIBUNWIND_TRACE_UNWINDING( 513 "unwind_phase1(ex_ojb=%p): calling personality function %p", 514 static_cast<void *>(exception_object), 515 reinterpret_cast<void *>(reinterpret_cast<uintptr_t>(p))); 516 struct _Unwind_Context *context = (struct _Unwind_Context *)(cursor); 517 exception_object->pr_cache.fnstart = frameInfo.start_ip; 518 exception_object->pr_cache.ehtp = 519 (_Unwind_EHT_Header *)frameInfo.unwind_info; 520 exception_object->pr_cache.additional = frameInfo.flags; 521 _Unwind_Reason_Code personalityResult = 522 (*p)(_US_VIRTUAL_UNWIND_FRAME, exception_object, context); 523 _LIBUNWIND_TRACE_UNWINDING( 524 "unwind_phase1(ex_ojb=%p): personality result %d start_ip %x ehtp %p " 525 "additional %x", 526 static_cast<void *>(exception_object), personalityResult, 527 exception_object->pr_cache.fnstart, 528 static_cast<void *>(exception_object->pr_cache.ehtp), 529 exception_object->pr_cache.additional); 530 switch (personalityResult) { 531 case _URC_HANDLER_FOUND: 532 // found a catch clause or locals that need destructing in this frame 533 // stop search and remember stack pointer at the frame 534 handlerNotFound = false; 535 // p should have initialized barrier_cache. EHABI #7.3.5 536 _LIBUNWIND_TRACE_UNWINDING( 537 "unwind_phase1(ex_ojb=%p): _URC_HANDLER_FOUND", 538 static_cast<void *>(exception_object)); 539 return _URC_NO_REASON; 540 541 case _URC_CONTINUE_UNWIND: 542 _LIBUNWIND_TRACE_UNWINDING( 543 "unwind_phase1(ex_ojb=%p): _URC_CONTINUE_UNWIND", 544 static_cast<void *>(exception_object)); 545 // continue unwinding 546 break; 547 548 // EHABI #7.3.3 549 case _URC_FAILURE: 550 return _URC_FAILURE; 551 552 default: 553 // something went wrong 554 _LIBUNWIND_TRACE_UNWINDING( 555 "unwind_phase1(ex_ojb=%p): _URC_FATAL_PHASE1_ERROR", 556 static_cast<void *>(exception_object)); 557 return _URC_FATAL_PHASE1_ERROR; 558 } 559 } 560 } 561 return _URC_NO_REASON; 562 } 563 564 static _Unwind_Reason_Code unwind_phase2(unw_context_t *uc, unw_cursor_t *cursor, 565 _Unwind_Exception *exception_object, 566 bool resume) { 567 // See comment at the start of unwind_phase1 regarding VRS integrity. 568 __unw_init_local(cursor, uc); 569 570 _LIBUNWIND_TRACE_UNWINDING("unwind_phase2(ex_ojb=%p)", 571 static_cast<void *>(exception_object)); 572 int frame_count = 0; 573 574 // Walk each frame until we reach where search phase said to stop. 575 while (true) { 576 // Ask libunwind to get next frame (skip over first which is 577 // _Unwind_RaiseException or _Unwind_Resume). 578 // 579 // Resume only ever makes sense for 1 frame. 580 _Unwind_State state = 581 resume ? _US_UNWIND_FRAME_RESUME : _US_UNWIND_FRAME_STARTING; 582 if (resume && frame_count == 1) { 583 // On a resume, first unwind the _Unwind_Resume() frame. The next frame 584 // is now the landing pad for the cleanup from a previous execution of 585 // phase2. To continue unwindingly correctly, replace VRS[15] with the 586 // IP of the frame that the previous run of phase2 installed the context 587 // for. After this, continue unwinding as if normal. 588 // 589 // See #7.4.6 for details. 590 __unw_set_reg(cursor, UNW_REG_IP, 591 exception_object->unwinder_cache.reserved2); 592 resume = false; 593 } 594 595 // Get info about this frame. 596 unw_word_t sp; 597 unw_proc_info_t frameInfo; 598 __unw_get_reg(cursor, UNW_REG_SP, &sp); 599 if (__unw_get_proc_info(cursor, &frameInfo) != UNW_ESUCCESS) { 600 _LIBUNWIND_TRACE_UNWINDING( 601 "unwind_phase2(ex_ojb=%p): __unw_get_proc_info " 602 "failed => _URC_FATAL_PHASE2_ERROR", 603 static_cast<void *>(exception_object)); 604 return _URC_FATAL_PHASE2_ERROR; 605 } 606 607 #ifndef NDEBUG 608 // When tracing, print state information. 609 if (_LIBUNWIND_TRACING_UNWINDING) { 610 char functionBuf[512]; 611 const char *functionName = functionBuf; 612 unw_word_t offset; 613 if ((__unw_get_proc_name(cursor, functionBuf, sizeof(functionBuf), 614 &offset) != UNW_ESUCCESS) || 615 (frameInfo.start_ip + offset > frameInfo.end_ip)) 616 functionName = ".anonymous."; 617 _LIBUNWIND_TRACE_UNWINDING( 618 "unwind_phase2(ex_ojb=%p): start_ip=0x%" PRIxPTR ", func=%s, sp=0x%" PRIxPTR ", " 619 "lsda=0x%" PRIxPTR ", personality=0x%" PRIxPTR "", 620 static_cast<void *>(exception_object), frameInfo.start_ip, 621 functionName, sp, frameInfo.lsda, 622 frameInfo.handler); 623 } 624 #endif 625 626 // If there is a personality routine, tell it we are unwinding. 627 if (frameInfo.handler != 0) { 628 _Unwind_Personality_Fn p = 629 (_Unwind_Personality_Fn)(intptr_t)(frameInfo.handler); 630 struct _Unwind_Context *context = (struct _Unwind_Context *)(cursor); 631 // EHABI #7.2 632 exception_object->pr_cache.fnstart = frameInfo.start_ip; 633 exception_object->pr_cache.ehtp = 634 (_Unwind_EHT_Header *)frameInfo.unwind_info; 635 exception_object->pr_cache.additional = frameInfo.flags; 636 _Unwind_Reason_Code personalityResult = 637 (*p)(state, exception_object, context); 638 switch (personalityResult) { 639 case _URC_CONTINUE_UNWIND: 640 // Continue unwinding 641 _LIBUNWIND_TRACE_UNWINDING( 642 "unwind_phase2(ex_ojb=%p): _URC_CONTINUE_UNWIND", 643 static_cast<void *>(exception_object)); 644 // EHABI #7.2 645 if (sp == exception_object->barrier_cache.sp) { 646 // Phase 1 said we would stop at this frame, but we did not... 647 _LIBUNWIND_ABORT("during phase1 personality function said it would " 648 "stop here, but now in phase2 it did not stop here"); 649 } 650 break; 651 case _URC_INSTALL_CONTEXT: 652 _LIBUNWIND_TRACE_UNWINDING( 653 "unwind_phase2(ex_ojb=%p): _URC_INSTALL_CONTEXT", 654 static_cast<void *>(exception_object)); 655 // Personality routine says to transfer control to landing pad. 656 // We may get control back if landing pad calls _Unwind_Resume(). 657 if (_LIBUNWIND_TRACING_UNWINDING) { 658 unw_word_t pc; 659 __unw_get_reg(cursor, UNW_REG_IP, &pc); 660 __unw_get_reg(cursor, UNW_REG_SP, &sp); 661 _LIBUNWIND_TRACE_UNWINDING("unwind_phase2(ex_ojb=%p): re-entering " 662 "user code with ip=0x%" PRIxPTR ", sp=0x%" PRIxPTR, 663 static_cast<void *>(exception_object), 664 pc, sp); 665 } 666 667 { 668 // EHABI #7.4.1 says we need to preserve pc for when _Unwind_Resume 669 // is called back, to find this same frame. 670 unw_word_t pc; 671 __unw_get_reg(cursor, UNW_REG_IP, &pc); 672 exception_object->unwinder_cache.reserved2 = (uint32_t)pc; 673 } 674 __unw_resume(cursor); 675 // __unw_resume() only returns if there was an error. 676 return _URC_FATAL_PHASE2_ERROR; 677 678 // # EHABI #7.4.3 679 case _URC_FAILURE: 680 abort(); 681 682 default: 683 // Personality routine returned an unknown result code. 684 _LIBUNWIND_DEBUG_LOG("personality function returned unknown result %d", 685 personalityResult); 686 return _URC_FATAL_PHASE2_ERROR; 687 } 688 } 689 frame_count++; 690 } 691 692 // Clean up phase did not resume at the frame that the search phase 693 // said it would... 694 return _URC_FATAL_PHASE2_ERROR; 695 } 696 697 static _Unwind_Reason_Code 698 unwind_phase2_forced(unw_context_t *uc, unw_cursor_t *cursor, 699 _Unwind_Exception *exception_object, _Unwind_Stop_Fn stop, 700 void *stop_parameter) { 701 bool endOfStack = false; 702 // See comment at the start of unwind_phase1 regarding VRS integrity. 703 __unw_init_local(cursor, uc); 704 _LIBUNWIND_TRACE_UNWINDING("unwind_phase2_force(ex_ojb=%p)", 705 static_cast<void *>(exception_object)); 706 // Walk each frame until we reach where search phase said to stop 707 while (!endOfStack) { 708 // Update info about this frame. 709 unw_proc_info_t frameInfo; 710 if (__unw_get_proc_info(cursor, &frameInfo) != UNW_ESUCCESS) { 711 _LIBUNWIND_TRACE_UNWINDING("unwind_phase2_forced(ex_ojb=%p): __unw_step " 712 "failed => _URC_END_OF_STACK", 713 (void *)exception_object); 714 return _URC_FATAL_PHASE2_ERROR; 715 } 716 717 #ifndef NDEBUG 718 // When tracing, print state information. 719 if (_LIBUNWIND_TRACING_UNWINDING) { 720 char functionBuf[512]; 721 const char *functionName = functionBuf; 722 unw_word_t offset; 723 if ((__unw_get_proc_name(cursor, functionBuf, sizeof(functionBuf), 724 &offset) != UNW_ESUCCESS) || 725 (frameInfo.start_ip + offset > frameInfo.end_ip)) 726 functionName = ".anonymous."; 727 _LIBUNWIND_TRACE_UNWINDING( 728 "unwind_phase2_forced(ex_ojb=%p): start_ip=0x%" PRIxPTR 729 ", func=%s, lsda=0x%" PRIxPTR ", personality=0x%" PRIxPTR, 730 (void *)exception_object, frameInfo.start_ip, functionName, 731 frameInfo.lsda, frameInfo.handler); 732 } 733 #endif 734 735 // Call stop function at each frame. 736 _Unwind_Action action = 737 (_Unwind_Action)(_UA_FORCE_UNWIND | _UA_CLEANUP_PHASE); 738 _Unwind_Reason_Code stopResult = 739 (*stop)(1, action, exception_object->exception_class, exception_object, 740 (_Unwind_Context *)(cursor), stop_parameter); 741 _LIBUNWIND_TRACE_UNWINDING( 742 "unwind_phase2_forced(ex_ojb=%p): stop function returned %d", 743 (void *)exception_object, stopResult); 744 if (stopResult != _URC_NO_REASON) { 745 _LIBUNWIND_TRACE_UNWINDING( 746 "unwind_phase2_forced(ex_ojb=%p): stopped by stop function", 747 (void *)exception_object); 748 return _URC_FATAL_PHASE2_ERROR; 749 } 750 751 // If there is a personality routine, tell it we are unwinding. 752 if (frameInfo.handler != 0) { 753 _Unwind_Personality_Fn p = 754 (_Unwind_Personality_Fn)(uintptr_t)(frameInfo.handler); 755 struct _Unwind_Context *context = (struct _Unwind_Context *)(cursor); 756 // EHABI #7.2 757 exception_object->pr_cache.fnstart = frameInfo.start_ip; 758 exception_object->pr_cache.ehtp = 759 (_Unwind_EHT_Header *)frameInfo.unwind_info; 760 exception_object->pr_cache.additional = frameInfo.flags; 761 _Unwind_Reason_Code personalityResult = 762 (*p)(_US_FORCE_UNWIND | _US_UNWIND_FRAME_STARTING, exception_object, 763 context); 764 switch (personalityResult) { 765 case _URC_CONTINUE_UNWIND: 766 _LIBUNWIND_TRACE_UNWINDING("unwind_phase2_forced(ex_ojb=%p): " 767 "personality returned " 768 "_URC_CONTINUE_UNWIND", 769 (void *)exception_object); 770 // Destructors called, continue unwinding 771 break; 772 case _URC_INSTALL_CONTEXT: 773 _LIBUNWIND_TRACE_UNWINDING("unwind_phase2_forced(ex_ojb=%p): " 774 "personality returned " 775 "_URC_INSTALL_CONTEXT", 776 (void *)exception_object); 777 // We may get control back if landing pad calls _Unwind_Resume(). 778 __unw_resume(cursor); 779 break; 780 case _URC_END_OF_STACK: 781 _LIBUNWIND_TRACE_UNWINDING("unwind_phase2_forced(ex_ojb=%p): " 782 "personality returned " 783 "_URC_END_OF_STACK", 784 (void *)exception_object); 785 // Personalty routine did the step and it can't step forward. 786 endOfStack = true; 787 break; 788 default: 789 // Personality routine returned an unknown result code. 790 _LIBUNWIND_TRACE_UNWINDING("unwind_phase2_forced(ex_ojb=%p): " 791 "personality returned %d, " 792 "_URC_FATAL_PHASE2_ERROR", 793 (void *)exception_object, personalityResult); 794 return _URC_FATAL_PHASE2_ERROR; 795 } 796 } 797 } 798 799 // Call stop function one last time and tell it we've reached the end 800 // of the stack. 801 _LIBUNWIND_TRACE_UNWINDING("unwind_phase2_forced(ex_ojb=%p): calling stop " 802 "function with _UA_END_OF_STACK", 803 (void *)exception_object); 804 _Unwind_Action lastAction = 805 (_Unwind_Action)(_UA_FORCE_UNWIND | _UA_CLEANUP_PHASE | _UA_END_OF_STACK); 806 (*stop)(1, lastAction, exception_object->exception_class, exception_object, 807 (struct _Unwind_Context *)(cursor), stop_parameter); 808 809 // Clean up phase did not resume at the frame that the search phase said it 810 // would. 811 return _URC_FATAL_PHASE2_ERROR; 812 } 813 814 /// Called by __cxa_throw. Only returns if there is a fatal error. 815 _LIBUNWIND_EXPORT _Unwind_Reason_Code 816 _Unwind_RaiseException(_Unwind_Exception *exception_object) { 817 _LIBUNWIND_TRACE_API("_Unwind_RaiseException(ex_obj=%p)", 818 static_cast<void *>(exception_object)); 819 unw_context_t uc; 820 unw_cursor_t cursor; 821 __unw_getcontext(&uc); 822 823 // This field for is for compatibility with GCC to say this isn't a forced 824 // unwind. EHABI #7.2 825 exception_object->unwinder_cache.reserved1 = 0; 826 827 // phase 1: the search phase 828 _Unwind_Reason_Code phase1 = unwind_phase1(&uc, &cursor, exception_object); 829 if (phase1 != _URC_NO_REASON) 830 return phase1; 831 832 // phase 2: the clean up phase 833 return unwind_phase2(&uc, &cursor, exception_object, false); 834 } 835 836 _LIBUNWIND_EXPORT void _Unwind_Complete(_Unwind_Exception* exception_object) { 837 // This is to be called when exception handling completes to give us a chance 838 // to perform any housekeeping. EHABI #7.2. But we have nothing to do here. 839 (void)exception_object; 840 } 841 842 /// When _Unwind_RaiseException() is in phase2, it hands control 843 /// to the personality function at each frame. The personality 844 /// may force a jump to a landing pad in that function, the landing 845 /// pad code may then call _Unwind_Resume() to continue with the 846 /// unwinding. Note: the call to _Unwind_Resume() is from compiler 847 /// geneated user code. All other _Unwind_* routines are called 848 /// by the C++ runtime __cxa_* routines. 849 /// 850 /// Note: re-throwing an exception (as opposed to continuing the unwind) 851 /// is implemented by having the code call __cxa_rethrow() which 852 /// in turn calls _Unwind_Resume_or_Rethrow(). 853 _LIBUNWIND_EXPORT void 854 _Unwind_Resume(_Unwind_Exception *exception_object) { 855 _LIBUNWIND_TRACE_API("_Unwind_Resume(ex_obj=%p)", 856 static_cast<void *>(exception_object)); 857 unw_context_t uc; 858 unw_cursor_t cursor; 859 __unw_getcontext(&uc); 860 861 if (exception_object->unwinder_cache.reserved1) 862 unwind_phase2_forced( 863 &uc, &cursor, exception_object, 864 (_Unwind_Stop_Fn)exception_object->unwinder_cache.reserved1, 865 (void *)exception_object->unwinder_cache.reserved3); 866 else 867 unwind_phase2(&uc, &cursor, exception_object, true); 868 869 // Clients assume _Unwind_Resume() does not return, so all we can do is abort. 870 _LIBUNWIND_ABORT("_Unwind_Resume() can't return"); 871 } 872 873 /// Called by personality handler during phase 2 to get LSDA for current frame. 874 _LIBUNWIND_EXPORT uintptr_t 875 _Unwind_GetLanguageSpecificData(struct _Unwind_Context *context) { 876 unw_cursor_t *cursor = (unw_cursor_t *)context; 877 unw_proc_info_t frameInfo; 878 uintptr_t result = 0; 879 if (__unw_get_proc_info(cursor, &frameInfo) == UNW_ESUCCESS) 880 result = (uintptr_t)frameInfo.lsda; 881 _LIBUNWIND_TRACE_API( 882 "_Unwind_GetLanguageSpecificData(context=%p) => 0x%llx", 883 static_cast<void *>(context), (long long)result); 884 return result; 885 } 886 887 static uint64_t ValueAsBitPattern(_Unwind_VRS_DataRepresentation representation, 888 void* valuep) { 889 uint64_t value = 0; 890 switch (representation) { 891 case _UVRSD_UINT32: 892 case _UVRSD_FLOAT: 893 memcpy(&value, valuep, sizeof(uint32_t)); 894 break; 895 896 case _UVRSD_VFPX: 897 case _UVRSD_UINT64: 898 case _UVRSD_DOUBLE: 899 memcpy(&value, valuep, sizeof(uint64_t)); 900 break; 901 } 902 return value; 903 } 904 905 _LIBUNWIND_EXPORT _Unwind_VRS_Result 906 _Unwind_VRS_Set(_Unwind_Context *context, _Unwind_VRS_RegClass regclass, 907 uint32_t regno, _Unwind_VRS_DataRepresentation representation, 908 void *valuep) { 909 _LIBUNWIND_TRACE_API("_Unwind_VRS_Set(context=%p, regclass=%d, reg=%d, " 910 "rep=%d, value=0x%llX)", 911 static_cast<void *>(context), regclass, regno, 912 representation, 913 ValueAsBitPattern(representation, valuep)); 914 unw_cursor_t *cursor = (unw_cursor_t *)context; 915 switch (regclass) { 916 case _UVRSC_CORE: 917 if (representation != _UVRSD_UINT32 || regno > 15) 918 return _UVRSR_FAILED; 919 return __unw_set_reg(cursor, (unw_regnum_t)(UNW_ARM_R0 + regno), 920 *(unw_word_t *)valuep) == UNW_ESUCCESS 921 ? _UVRSR_OK 922 : _UVRSR_FAILED; 923 case _UVRSC_VFP: 924 if (representation != _UVRSD_VFPX && representation != _UVRSD_DOUBLE) 925 return _UVRSR_FAILED; 926 if (representation == _UVRSD_VFPX) { 927 // Can only touch d0-15 with FSTMFDX. 928 if (regno > 15) 929 return _UVRSR_FAILED; 930 __unw_save_vfp_as_X(cursor); 931 } else { 932 if (regno > 31) 933 return _UVRSR_FAILED; 934 } 935 return __unw_set_fpreg(cursor, (unw_regnum_t)(UNW_ARM_D0 + regno), 936 *(unw_fpreg_t *)valuep) == UNW_ESUCCESS 937 ? _UVRSR_OK 938 : _UVRSR_FAILED; 939 #if defined(__ARM_WMMX) 940 case _UVRSC_WMMXC: 941 if (representation != _UVRSD_UINT32 || regno > 3) 942 return _UVRSR_FAILED; 943 return __unw_set_reg(cursor, (unw_regnum_t)(UNW_ARM_WC0 + regno), 944 *(unw_word_t *)valuep) == UNW_ESUCCESS 945 ? _UVRSR_OK 946 : _UVRSR_FAILED; 947 case _UVRSC_WMMXD: 948 if (representation != _UVRSD_DOUBLE || regno > 31) 949 return _UVRSR_FAILED; 950 return __unw_set_fpreg(cursor, (unw_regnum_t)(UNW_ARM_WR0 + regno), 951 *(unw_fpreg_t *)valuep) == UNW_ESUCCESS 952 ? _UVRSR_OK 953 : _UVRSR_FAILED; 954 #else 955 case _UVRSC_WMMXC: 956 case _UVRSC_WMMXD: 957 break; 958 #endif 959 case _UVRSC_PSEUDO: 960 // There's only one pseudo-register, PAC, with regno == 0. 961 if (representation != _UVRSD_UINT32 || regno != 0) 962 return _UVRSR_FAILED; 963 return __unw_set_reg(cursor, (unw_regnum_t)(UNW_ARM_RA_AUTH_CODE), 964 *(unw_word_t *)valuep) == UNW_ESUCCESS 965 ? _UVRSR_OK 966 : _UVRSR_FAILED; 967 break; 968 } 969 _LIBUNWIND_ABORT("unsupported register class"); 970 } 971 972 static _Unwind_VRS_Result 973 _Unwind_VRS_Get_Internal(_Unwind_Context *context, 974 _Unwind_VRS_RegClass regclass, uint32_t regno, 975 _Unwind_VRS_DataRepresentation representation, 976 void *valuep) { 977 unw_cursor_t *cursor = (unw_cursor_t *)context; 978 switch (regclass) { 979 case _UVRSC_CORE: 980 if (representation != _UVRSD_UINT32 || regno > 15) 981 return _UVRSR_FAILED; 982 return __unw_get_reg(cursor, (unw_regnum_t)(UNW_ARM_R0 + regno), 983 (unw_word_t *)valuep) == UNW_ESUCCESS 984 ? _UVRSR_OK 985 : _UVRSR_FAILED; 986 case _UVRSC_VFP: 987 if (representation != _UVRSD_VFPX && representation != _UVRSD_DOUBLE) 988 return _UVRSR_FAILED; 989 if (representation == _UVRSD_VFPX) { 990 // Can only touch d0-15 with FSTMFDX. 991 if (regno > 15) 992 return _UVRSR_FAILED; 993 __unw_save_vfp_as_X(cursor); 994 } else { 995 if (regno > 31) 996 return _UVRSR_FAILED; 997 } 998 return __unw_get_fpreg(cursor, (unw_regnum_t)(UNW_ARM_D0 + regno), 999 (unw_fpreg_t *)valuep) == UNW_ESUCCESS 1000 ? _UVRSR_OK 1001 : _UVRSR_FAILED; 1002 #if defined(__ARM_WMMX) 1003 case _UVRSC_WMMXC: 1004 if (representation != _UVRSD_UINT32 || regno > 3) 1005 return _UVRSR_FAILED; 1006 return __unw_get_reg(cursor, (unw_regnum_t)(UNW_ARM_WC0 + regno), 1007 (unw_word_t *)valuep) == UNW_ESUCCESS 1008 ? _UVRSR_OK 1009 : _UVRSR_FAILED; 1010 case _UVRSC_WMMXD: 1011 if (representation != _UVRSD_DOUBLE || regno > 31) 1012 return _UVRSR_FAILED; 1013 return __unw_get_fpreg(cursor, (unw_regnum_t)(UNW_ARM_WR0 + regno), 1014 (unw_fpreg_t *)valuep) == UNW_ESUCCESS 1015 ? _UVRSR_OK 1016 : _UVRSR_FAILED; 1017 #else 1018 case _UVRSC_WMMXC: 1019 case _UVRSC_WMMXD: 1020 break; 1021 #endif 1022 case _UVRSC_PSEUDO: 1023 // There's only one pseudo-register, PAC, with regno == 0. 1024 if (representation != _UVRSD_UINT32 || regno != 0) 1025 return _UVRSR_FAILED; 1026 return __unw_get_reg(cursor, (unw_regnum_t)(UNW_ARM_RA_AUTH_CODE), 1027 (unw_word_t *)valuep) == UNW_ESUCCESS 1028 ? _UVRSR_OK 1029 : _UVRSR_FAILED; 1030 break; 1031 } 1032 _LIBUNWIND_ABORT("unsupported register class"); 1033 } 1034 1035 _LIBUNWIND_EXPORT _Unwind_VRS_Result 1036 _Unwind_VRS_Get(_Unwind_Context *context, _Unwind_VRS_RegClass regclass, 1037 uint32_t regno, _Unwind_VRS_DataRepresentation representation, 1038 void *valuep) { 1039 _Unwind_VRS_Result result = 1040 _Unwind_VRS_Get_Internal(context, regclass, regno, representation, 1041 valuep); 1042 _LIBUNWIND_TRACE_API("_Unwind_VRS_Get(context=%p, regclass=%d, reg=%d, " 1043 "rep=%d, value=0x%llX, result = %d)", 1044 static_cast<void *>(context), regclass, regno, 1045 representation, 1046 ValueAsBitPattern(representation, valuep), result); 1047 return result; 1048 } 1049 1050 _Unwind_VRS_Result 1051 _Unwind_VRS_Pop(_Unwind_Context *context, _Unwind_VRS_RegClass regclass, 1052 uint32_t discriminator, 1053 _Unwind_VRS_DataRepresentation representation) { 1054 _LIBUNWIND_TRACE_API("_Unwind_VRS_Pop(context=%p, regclass=%d, " 1055 "discriminator=%d, representation=%d)", 1056 static_cast<void *>(context), regclass, discriminator, 1057 representation); 1058 switch (regclass) { 1059 case _UVRSC_WMMXC: 1060 #if !defined(__ARM_WMMX) 1061 break; 1062 #endif 1063 case _UVRSC_CORE: { 1064 if (representation != _UVRSD_UINT32) 1065 return _UVRSR_FAILED; 1066 // When popping SP from the stack, we don't want to override it from the 1067 // computed new stack location. See EHABI #7.5.4 table 3. 1068 bool poppedSP = false; 1069 uint32_t* sp; 1070 if (_Unwind_VRS_Get(context, _UVRSC_CORE, UNW_ARM_SP, 1071 _UVRSD_UINT32, &sp) != _UVRSR_OK) { 1072 return _UVRSR_FAILED; 1073 } 1074 for (uint32_t i = 0; i < 16; ++i) { 1075 if (!(discriminator & static_cast<uint32_t>(1 << i))) 1076 continue; 1077 uint32_t value = *sp++; 1078 if (regclass == _UVRSC_CORE && i == 13) 1079 poppedSP = true; 1080 if (_Unwind_VRS_Set(context, regclass, i, 1081 _UVRSD_UINT32, &value) != _UVRSR_OK) { 1082 return _UVRSR_FAILED; 1083 } 1084 } 1085 if (!poppedSP) { 1086 return _Unwind_VRS_Set(context, _UVRSC_CORE, UNW_ARM_SP, 1087 _UVRSD_UINT32, &sp); 1088 } 1089 return _UVRSR_OK; 1090 } 1091 case _UVRSC_WMMXD: 1092 #if !defined(__ARM_WMMX) 1093 break; 1094 #endif 1095 case _UVRSC_VFP: { 1096 if (representation != _UVRSD_VFPX && representation != _UVRSD_DOUBLE) 1097 return _UVRSR_FAILED; 1098 uint32_t first = discriminator >> 16; 1099 uint32_t count = discriminator & 0xffff; 1100 uint32_t end = first+count; 1101 uint32_t* sp; 1102 if (_Unwind_VRS_Get(context, _UVRSC_CORE, UNW_ARM_SP, 1103 _UVRSD_UINT32, &sp) != _UVRSR_OK) { 1104 return _UVRSR_FAILED; 1105 } 1106 // For _UVRSD_VFPX, we're assuming the data is stored in FSTMX "standard 1107 // format 1", which is equivalent to FSTMD + a padding word. 1108 for (uint32_t i = first; i < end; ++i) { 1109 // SP is only 32-bit aligned so don't copy 64-bit at a time. 1110 uint64_t w0 = *sp++; 1111 uint64_t w1 = *sp++; 1112 #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__ 1113 uint64_t value = (w1 << 32) | w0; 1114 #elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__ 1115 uint64_t value = (w0 << 32) | w1; 1116 #else 1117 #error "Unable to determine endianess" 1118 #endif 1119 if (_Unwind_VRS_Set(context, regclass, i, representation, &value) != 1120 _UVRSR_OK) 1121 return _UVRSR_FAILED; 1122 } 1123 if (representation == _UVRSD_VFPX) 1124 ++sp; 1125 return _Unwind_VRS_Set(context, _UVRSC_CORE, UNW_ARM_SP, _UVRSD_UINT32, 1126 &sp); 1127 } 1128 case _UVRSC_PSEUDO: { 1129 if (representation != _UVRSD_UINT32 || discriminator != 0) 1130 return _UVRSR_FAILED; 1131 // Return Address Authentication code (PAC) - discriminator 0 1132 uint32_t *sp; 1133 if (_Unwind_VRS_Get(context, _UVRSC_CORE, UNW_ARM_SP, _UVRSD_UINT32, 1134 &sp) != _UVRSR_OK) { 1135 return _UVRSR_FAILED; 1136 } 1137 uint32_t pac = *sp++; 1138 _Unwind_VRS_Set(context, _UVRSC_CORE, UNW_ARM_SP, _UVRSD_UINT32, &sp); 1139 return _Unwind_VRS_Set(context, _UVRSC_CORE, UNW_ARM_RA_AUTH_CODE, 1140 _UVRSD_UINT32, &pac); 1141 } 1142 } 1143 _LIBUNWIND_ABORT("unsupported register class"); 1144 } 1145 1146 /// Not used by C++. 1147 /// Unwinds stack, calling "stop" function at each frame. 1148 /// Could be used to implement longjmp(). 1149 _LIBUNWIND_EXPORT _Unwind_Reason_Code 1150 _Unwind_ForcedUnwind(_Unwind_Exception *exception_object, _Unwind_Stop_Fn stop, 1151 void *stop_parameter) { 1152 _LIBUNWIND_TRACE_API("_Unwind_ForcedUnwind(ex_obj=%p, stop=%p)", 1153 (void *)exception_object, (void *)(uintptr_t)stop); 1154 unw_context_t uc; 1155 unw_cursor_t cursor; 1156 __unw_getcontext(&uc); 1157 1158 // Mark that this is a forced unwind, so _Unwind_Resume() can do 1159 // the right thing. 1160 exception_object->unwinder_cache.reserved1 = (uintptr_t)stop; 1161 exception_object->unwinder_cache.reserved3 = (uintptr_t)stop_parameter; 1162 1163 return unwind_phase2_forced(&uc, &cursor, exception_object, stop, 1164 stop_parameter); 1165 } 1166 1167 /// Called by personality handler during phase 2 to find the start of the 1168 /// function. 1169 _LIBUNWIND_EXPORT uintptr_t 1170 _Unwind_GetRegionStart(struct _Unwind_Context *context) { 1171 unw_cursor_t *cursor = (unw_cursor_t *)context; 1172 unw_proc_info_t frameInfo; 1173 uintptr_t result = 0; 1174 if (__unw_get_proc_info(cursor, &frameInfo) == UNW_ESUCCESS) 1175 result = (uintptr_t)frameInfo.start_ip; 1176 _LIBUNWIND_TRACE_API("_Unwind_GetRegionStart(context=%p) => 0x%llX", 1177 static_cast<void *>(context), (long long)result); 1178 return result; 1179 } 1180 1181 1182 /// Called by personality handler during phase 2 if a foreign exception 1183 // is caught. 1184 _LIBUNWIND_EXPORT void 1185 _Unwind_DeleteException(_Unwind_Exception *exception_object) { 1186 _LIBUNWIND_TRACE_API("_Unwind_DeleteException(ex_obj=%p)", 1187 static_cast<void *>(exception_object)); 1188 if (exception_object->exception_cleanup != NULL) 1189 (*exception_object->exception_cleanup)(_URC_FOREIGN_EXCEPTION_CAUGHT, 1190 exception_object); 1191 } 1192 1193 extern "C" _LIBUNWIND_EXPORT _Unwind_Reason_Code 1194 __gnu_unwind_frame(_Unwind_Exception *exception_object, 1195 struct _Unwind_Context *context) { 1196 unw_cursor_t *cursor = (unw_cursor_t *)context; 1197 switch (__unw_step(cursor)) { 1198 case UNW_STEP_SUCCESS: 1199 return _URC_OK; 1200 case UNW_STEP_END: 1201 return _URC_END_OF_STACK; 1202 default: 1203 return _URC_FAILURE; 1204 } 1205 } 1206 1207 #endif // defined(_LIBUNWIND_ARM_EHABI) 1208