| /* |
| * Copyright (C) 2017 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| #include <stdint.h> |
| |
| #include <algorithm> |
| #include <optional> |
| #include <tuple> |
| #include <utility> |
| #include <vector> |
| |
| #include <unwindstack/DwarfError.h> |
| #include <unwindstack/DwarfLocation.h> |
| #include <unwindstack/DwarfMemory.h> |
| #include <unwindstack/DwarfSection.h> |
| #include <unwindstack/DwarfStructs.h> |
| #include <unwindstack/Elf.h> |
| #include <unwindstack/Log.h> |
| #include <unwindstack/Memory.h> |
| #include <unwindstack/Regs.h> |
| |
| #include "DwarfCfa.h" |
| #include "DwarfDebugFrame.h" |
| #include "DwarfEhFrame.h" |
| #include "DwarfEncoding.h" |
| #include "DwarfOp.h" |
| #include "RegsInfo.h" |
| |
| namespace unwindstack { |
| |
| DwarfSection::DwarfSection(Memory* memory) : memory_(memory) {} |
| |
| bool DwarfSection::Step(uint64_t pc, Regs* regs, Memory* process_memory, bool* finished, |
| bool* is_signal_frame) { |
| // Lookup the pc in the cache. |
| auto it = loc_regs_.upper_bound(pc); |
| if (it == loc_regs_.end() || pc < it->second.pc_start) { |
| last_error_.code = DWARF_ERROR_NONE; |
| const DwarfFde* fde = GetFdeFromPc(pc); |
| if (fde == nullptr || fde->cie == nullptr) { |
| last_error_.code = DWARF_ERROR_ILLEGAL_STATE; |
| return false; |
| } |
| |
| // Now get the location information for this pc. |
| DwarfLocations loc_regs; |
| if (!GetCfaLocationInfo(pc, fde, &loc_regs, regs->Arch())) { |
| return false; |
| } |
| loc_regs.cie = fde->cie; |
| |
| // Store it in the cache. |
| it = loc_regs_.emplace(loc_regs.pc_end, std::move(loc_regs)).first; |
| } |
| |
| *is_signal_frame = it->second.cie->is_signal_frame; |
| |
| // Now eval the actual registers. |
| return Eval(it->second.cie, process_memory, it->second, regs, finished); |
| } |
| |
| template <typename AddressType> |
| const DwarfCie* DwarfSectionImpl<AddressType>::GetCieFromOffset(uint64_t offset) { |
| auto cie_entry = cie_entries_.find(offset); |
| if (cie_entry != cie_entries_.end()) { |
| return &cie_entry->second; |
| } |
| DwarfCie* cie = &cie_entries_[offset]; |
| memory_.set_data_offset(entries_offset_); |
| memory_.set_cur_offset(offset); |
| if (!FillInCieHeader(cie) || !FillInCie(cie)) { |
| // Erase the cached entry. |
| cie_entries_.erase(offset); |
| return nullptr; |
| } |
| return cie; |
| } |
| |
| template <typename AddressType> |
| bool DwarfSectionImpl<AddressType>::FillInCieHeader(DwarfCie* cie) { |
| cie->lsda_encoding = DW_EH_PE_omit; |
| uint32_t length32; |
| if (!memory_.ReadBytes(&length32, sizeof(length32))) { |
| last_error_.code = DWARF_ERROR_MEMORY_INVALID; |
| last_error_.address = memory_.cur_offset(); |
| return false; |
| } |
| if (length32 == static_cast<uint32_t>(-1)) { |
| // 64 bit Cie |
| uint64_t length64; |
| if (!memory_.ReadBytes(&length64, sizeof(length64))) { |
| last_error_.code = DWARF_ERROR_MEMORY_INVALID; |
| last_error_.address = memory_.cur_offset(); |
| return false; |
| } |
| |
| cie->cfa_instructions_end = memory_.cur_offset() + length64; |
| // TODO(b/192012848): This is wrong. We need to propagate pointer size here. |
| cie->fde_address_encoding = DW_EH_PE_udata8; |
| |
| uint64_t cie_id; |
| if (!memory_.ReadBytes(&cie_id, sizeof(cie_id))) { |
| last_error_.code = DWARF_ERROR_MEMORY_INVALID; |
| last_error_.address = memory_.cur_offset(); |
| return false; |
| } |
| if (cie_id != cie64_value_) { |
| // This is not a Cie, something has gone horribly wrong. |
| last_error_.code = DWARF_ERROR_ILLEGAL_VALUE; |
| return false; |
| } |
| } else { |
| // 32 bit Cie |
| cie->cfa_instructions_end = memory_.cur_offset() + length32; |
| // TODO(b/192012848): This is wrong. We need to propagate pointer size here. |
| cie->fde_address_encoding = DW_EH_PE_udata4; |
| |
| uint32_t cie_id; |
| if (!memory_.ReadBytes(&cie_id, sizeof(cie_id))) { |
| last_error_.code = DWARF_ERROR_MEMORY_INVALID; |
| last_error_.address = memory_.cur_offset(); |
| return false; |
| } |
| if (cie_id != cie32_value_) { |
| // This is not a Cie, something has gone horribly wrong. |
| last_error_.code = DWARF_ERROR_ILLEGAL_VALUE; |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| template <typename AddressType> |
| bool DwarfSectionImpl<AddressType>::FillInCie(DwarfCie* cie) { |
| if (!memory_.ReadBytes(&cie->version, sizeof(cie->version))) { |
| last_error_.code = DWARF_ERROR_MEMORY_INVALID; |
| last_error_.address = memory_.cur_offset(); |
| return false; |
| } |
| |
| if (cie->version != 1 && cie->version != 3 && cie->version != 4 && cie->version != 5) { |
| // Unrecognized version. |
| last_error_.code = DWARF_ERROR_UNSUPPORTED_VERSION; |
| return false; |
| } |
| |
| // Read the augmentation string. |
| char aug_value; |
| do { |
| if (!memory_.ReadBytes(&aug_value, 1)) { |
| last_error_.code = DWARF_ERROR_MEMORY_INVALID; |
| last_error_.address = memory_.cur_offset(); |
| return false; |
| } |
| cie->augmentation_string.push_back(aug_value); |
| } while (aug_value != '\0'); |
| |
| if (cie->version == 4 || cie->version == 5) { |
| char address_size; |
| if (!memory_.ReadBytes(&address_size, 1)) { |
| last_error_.code = DWARF_ERROR_MEMORY_INVALID; |
| last_error_.address = memory_.cur_offset(); |
| return false; |
| } |
| cie->fde_address_encoding = address_size == 8 ? DW_EH_PE_udata8 : DW_EH_PE_udata4; |
| |
| // Segment Size |
| if (!memory_.ReadBytes(&cie->segment_size, 1)) { |
| last_error_.code = DWARF_ERROR_MEMORY_INVALID; |
| last_error_.address = memory_.cur_offset(); |
| return false; |
| } |
| } |
| |
| // Code Alignment Factor |
| if (!memory_.ReadULEB128(&cie->code_alignment_factor)) { |
| last_error_.code = DWARF_ERROR_MEMORY_INVALID; |
| last_error_.address = memory_.cur_offset(); |
| return false; |
| } |
| |
| // Data Alignment Factor |
| if (!memory_.ReadSLEB128(&cie->data_alignment_factor)) { |
| last_error_.code = DWARF_ERROR_MEMORY_INVALID; |
| last_error_.address = memory_.cur_offset(); |
| return false; |
| } |
| |
| if (cie->version == 1) { |
| // Return Address is a single byte. |
| uint8_t return_address_register; |
| if (!memory_.ReadBytes(&return_address_register, 1)) { |
| last_error_.code = DWARF_ERROR_MEMORY_INVALID; |
| last_error_.address = memory_.cur_offset(); |
| return false; |
| } |
| cie->return_address_register = return_address_register; |
| } else if (!memory_.ReadULEB128(&cie->return_address_register)) { |
| last_error_.code = DWARF_ERROR_MEMORY_INVALID; |
| last_error_.address = memory_.cur_offset(); |
| return false; |
| } |
| |
| if (cie->augmentation_string[0] != 'z') { |
| cie->cfa_instructions_offset = memory_.cur_offset(); |
| return true; |
| } |
| |
| uint64_t aug_length; |
| if (!memory_.ReadULEB128(&aug_length)) { |
| last_error_.code = DWARF_ERROR_MEMORY_INVALID; |
| last_error_.address = memory_.cur_offset(); |
| return false; |
| } |
| cie->cfa_instructions_offset = memory_.cur_offset() + aug_length; |
| |
| for (size_t i = 1; i < cie->augmentation_string.size(); i++) { |
| switch (cie->augmentation_string[i]) { |
| case 'L': |
| if (!memory_.ReadBytes(&cie->lsda_encoding, 1)) { |
| last_error_.code = DWARF_ERROR_MEMORY_INVALID; |
| last_error_.address = memory_.cur_offset(); |
| return false; |
| } |
| break; |
| case 'P': { |
| uint8_t encoding; |
| if (!memory_.ReadBytes(&encoding, 1)) { |
| last_error_.code = DWARF_ERROR_MEMORY_INVALID; |
| last_error_.address = memory_.cur_offset(); |
| return false; |
| } |
| memory_.set_pc_offset(pc_offset_); |
| if (!memory_.ReadEncodedValue<AddressType>(encoding, &cie->personality_handler)) { |
| last_error_.code = DWARF_ERROR_MEMORY_INVALID; |
| last_error_.address = memory_.cur_offset(); |
| return false; |
| } |
| } break; |
| case 'R': |
| if (!memory_.ReadBytes(&cie->fde_address_encoding, 1)) { |
| last_error_.code = DWARF_ERROR_MEMORY_INVALID; |
| last_error_.address = memory_.cur_offset(); |
| return false; |
| } |
| break; |
| case 'S': |
| cie->is_signal_frame = true; |
| break; |
| } |
| } |
| return true; |
| } |
| |
| template <typename AddressType> |
| const DwarfFde* DwarfSectionImpl<AddressType>::GetFdeFromOffset(uint64_t offset) { |
| auto fde_entry = fde_entries_.find(offset); |
| if (fde_entry != fde_entries_.end()) { |
| return &fde_entry->second; |
| } |
| DwarfFde* fde = &fde_entries_[offset]; |
| memory_.set_data_offset(entries_offset_); |
| memory_.set_cur_offset(offset); |
| if (!FillInFdeHeader(fde) || !FillInFde(fde)) { |
| fde_entries_.erase(offset); |
| return nullptr; |
| } |
| return fde; |
| } |
| |
| template <typename AddressType> |
| bool DwarfSectionImpl<AddressType>::FillInFdeHeader(DwarfFde* fde) { |
| uint32_t length32; |
| if (!memory_.ReadBytes(&length32, sizeof(length32))) { |
| last_error_.code = DWARF_ERROR_MEMORY_INVALID; |
| last_error_.address = memory_.cur_offset(); |
| return false; |
| } |
| |
| if (length32 == static_cast<uint32_t>(-1)) { |
| // 64 bit Fde. |
| uint64_t length64; |
| if (!memory_.ReadBytes(&length64, sizeof(length64))) { |
| last_error_.code = DWARF_ERROR_MEMORY_INVALID; |
| last_error_.address = memory_.cur_offset(); |
| return false; |
| } |
| fde->cfa_instructions_end = memory_.cur_offset() + length64; |
| |
| uint64_t value64; |
| if (!memory_.ReadBytes(&value64, sizeof(value64))) { |
| last_error_.code = DWARF_ERROR_MEMORY_INVALID; |
| last_error_.address = memory_.cur_offset(); |
| return false; |
| } |
| if (value64 == cie64_value_) { |
| // This is a Cie, this means something has gone wrong. |
| last_error_.code = DWARF_ERROR_ILLEGAL_VALUE; |
| return false; |
| } |
| |
| // Get the Cie pointer, which is necessary to properly read the rest of |
| // of the Fde information. |
| fde->cie_offset = GetCieOffsetFromFde64(value64); |
| } else { |
| // 32 bit Fde. |
| fde->cfa_instructions_end = memory_.cur_offset() + length32; |
| |
| uint32_t value32; |
| if (!memory_.ReadBytes(&value32, sizeof(value32))) { |
| last_error_.code = DWARF_ERROR_MEMORY_INVALID; |
| last_error_.address = memory_.cur_offset(); |
| return false; |
| } |
| if (value32 == cie32_value_) { |
| // This is a Cie, this means something has gone wrong. |
| last_error_.code = DWARF_ERROR_ILLEGAL_VALUE; |
| return false; |
| } |
| |
| // Get the Cie pointer, which is necessary to properly read the rest of |
| // of the Fde information. |
| fde->cie_offset = GetCieOffsetFromFde32(value32); |
| } |
| return true; |
| } |
| |
| template <typename AddressType> |
| bool DwarfSectionImpl<AddressType>::FillInFde(DwarfFde* fde) { |
| uint64_t cur_offset = memory_.cur_offset(); |
| |
| const DwarfCie* cie = GetCieFromOffset(fde->cie_offset); |
| if (cie == nullptr) { |
| return false; |
| } |
| fde->cie = cie; |
| |
| if (cie->segment_size != 0) { |
| // Skip over the segment selector for now. |
| cur_offset += cie->segment_size; |
| } |
| memory_.set_cur_offset(cur_offset); |
| |
| // The load bias only applies to the start. |
| memory_.set_pc_offset(section_bias_); |
| bool valid = memory_.ReadEncodedValue<AddressType>(cie->fde_address_encoding, &fde->pc_start); |
| fde->pc_start = AdjustPcFromFde(fde->pc_start); |
| |
| memory_.set_pc_offset(0); |
| if (!valid || !memory_.ReadEncodedValue<AddressType>(cie->fde_address_encoding, &fde->pc_end)) { |
| last_error_.code = DWARF_ERROR_MEMORY_INVALID; |
| last_error_.address = memory_.cur_offset(); |
| return false; |
| } |
| fde->pc_end += fde->pc_start; |
| |
| if (cie->augmentation_string.size() > 0 && cie->augmentation_string[0] == 'z') { |
| // Augmentation Size |
| uint64_t aug_length; |
| if (!memory_.ReadULEB128(&aug_length)) { |
| last_error_.code = DWARF_ERROR_MEMORY_INVALID; |
| last_error_.address = memory_.cur_offset(); |
| return false; |
| } |
| uint64_t cur_offset = memory_.cur_offset(); |
| |
| memory_.set_pc_offset(pc_offset_); |
| if (!memory_.ReadEncodedValue<AddressType>(cie->lsda_encoding, &fde->lsda_address)) { |
| last_error_.code = DWARF_ERROR_MEMORY_INVALID; |
| last_error_.address = memory_.cur_offset(); |
| return false; |
| } |
| |
| // Set our position to after all of the augmentation data. |
| memory_.set_cur_offset(cur_offset + aug_length); |
| } |
| fde->cfa_instructions_offset = memory_.cur_offset(); |
| |
| return true; |
| } |
| |
| template <typename AddressType> |
| bool DwarfSectionImpl<AddressType>::EvalExpression(const DwarfLocation& loc, Memory* regular_memory, |
| AddressType* value, |
| RegsInfo<AddressType>* regs_info, |
| bool* is_dex_pc) { |
| DwarfOp<AddressType> op(&memory_, regular_memory); |
| op.set_regs_info(regs_info); |
| |
| // Need to evaluate the op data. |
| uint64_t end = loc.values[1]; |
| uint64_t start = end - loc.values[0]; |
| if (!op.Eval(start, end)) { |
| last_error_ = op.last_error(); |
| return false; |
| } |
| if (op.StackSize() == 0) { |
| last_error_.code = DWARF_ERROR_ILLEGAL_STATE; |
| return false; |
| } |
| // We don't support an expression that evaluates to a register number. |
| if (op.is_register()) { |
| last_error_.code = DWARF_ERROR_NOT_IMPLEMENTED; |
| return false; |
| } |
| *value = op.StackAt(0); |
| if (is_dex_pc != nullptr && op.dex_pc_set()) { |
| *is_dex_pc = true; |
| } |
| return true; |
| } |
| |
| template <typename AddressType> |
| struct EvalInfo { |
| const DwarfLocations* loc_regs; |
| const DwarfCie* cie; |
| Memory* regular_memory; |
| AddressType cfa; |
| bool return_address_undefined = false; |
| RegsInfo<AddressType> regs_info; |
| }; |
| |
| template <typename AddressType> |
| bool DwarfSectionImpl<AddressType>::EvalRegister(const DwarfLocation* loc, uint32_t reg, |
| AddressType* reg_ptr, void* info) { |
| EvalInfo<AddressType>* eval_info = reinterpret_cast<EvalInfo<AddressType>*>(info); |
| Memory* regular_memory = eval_info->regular_memory; |
| switch (loc->type) { |
| case DWARF_LOCATION_OFFSET: |
| if (!regular_memory->ReadFully(eval_info->cfa + loc->values[0], reg_ptr, sizeof(AddressType))) { |
| last_error_.code = DWARF_ERROR_MEMORY_INVALID; |
| last_error_.address = eval_info->cfa + loc->values[0]; |
| return false; |
| } |
| break; |
| case DWARF_LOCATION_VAL_OFFSET: |
| *reg_ptr = eval_info->cfa + loc->values[0]; |
| break; |
| case DWARF_LOCATION_REGISTER: { |
| uint32_t cur_reg = loc->values[0]; |
| if (cur_reg >= eval_info->regs_info.Total()) { |
| last_error_.code = DWARF_ERROR_ILLEGAL_VALUE; |
| return false; |
| } |
| *reg_ptr = eval_info->regs_info.Get(cur_reg) + loc->values[1]; |
| break; |
| } |
| case DWARF_LOCATION_EXPRESSION: |
| case DWARF_LOCATION_VAL_EXPRESSION: { |
| AddressType value; |
| bool is_dex_pc = false; |
| if (!EvalExpression(*loc, regular_memory, &value, &eval_info->regs_info, &is_dex_pc)) { |
| return false; |
| } |
| if (loc->type == DWARF_LOCATION_EXPRESSION) { |
| if (!regular_memory->ReadFully(value, reg_ptr, sizeof(AddressType))) { |
| last_error_.code = DWARF_ERROR_MEMORY_INVALID; |
| last_error_.address = value; |
| return false; |
| } |
| } else { |
| *reg_ptr = value; |
| if (is_dex_pc) { |
| eval_info->regs_info.regs->set_dex_pc(value); |
| } |
| } |
| break; |
| } |
| case DWARF_LOCATION_UNDEFINED: |
| if (reg == eval_info->cie->return_address_register) { |
| eval_info->return_address_undefined = true; |
| } |
| break; |
| case DWARF_LOCATION_PSEUDO_REGISTER: |
| last_error_.code = DWARF_ERROR_ILLEGAL_VALUE; |
| return false; |
| default: |
| break; |
| } |
| |
| return true; |
| } |
| |
| template <typename AddressType> |
| bool DwarfSectionImpl<AddressType>::Eval(const DwarfCie* cie, Memory* regular_memory, |
| const DwarfLocations& loc_regs, Regs* regs, |
| bool* finished) { |
| RegsImpl<AddressType>* cur_regs = reinterpret_cast<RegsImpl<AddressType>*>(regs); |
| if (cie->return_address_register >= cur_regs->total_regs()) { |
| last_error_.code = DWARF_ERROR_ILLEGAL_VALUE; |
| return false; |
| } |
| |
| // Get the cfa value; |
| auto cfa_entry = loc_regs.find(CFA_REG); |
| if (cfa_entry == loc_regs.end()) { |
| last_error_.code = DWARF_ERROR_CFA_NOT_DEFINED; |
| return false; |
| } |
| |
| // Always set the dex pc to zero when evaluating. |
| cur_regs->set_dex_pc(0); |
| |
| // Reset necessary pseudo registers before evaluation. |
| // This is needed for ARM64, for example. |
| regs->ResetPseudoRegisters(); |
| |
| EvalInfo<AddressType> eval_info{.loc_regs = &loc_regs, |
| .cie = cie, |
| .regular_memory = regular_memory, |
| .regs_info = RegsInfo<AddressType>(cur_regs)}; |
| const DwarfLocation* loc = &cfa_entry->second; |
| // Only a few location types are valid for the cfa. |
| switch (loc->type) { |
| case DWARF_LOCATION_REGISTER: |
| if (loc->values[0] >= cur_regs->total_regs()) { |
| last_error_.code = DWARF_ERROR_ILLEGAL_VALUE; |
| return false; |
| } |
| eval_info.cfa = (*cur_regs)[loc->values[0]]; |
| eval_info.cfa += loc->values[1]; |
| break; |
| case DWARF_LOCATION_VAL_EXPRESSION: { |
| AddressType value; |
| if (!EvalExpression(*loc, regular_memory, &value, &eval_info.regs_info, nullptr)) { |
| return false; |
| } |
| // There is only one type of valid expression for CFA evaluation. |
| eval_info.cfa = value; |
| break; |
| } |
| default: |
| last_error_.code = DWARF_ERROR_ILLEGAL_VALUE; |
| return false; |
| } |
| |
| for (const auto& entry : loc_regs) { |
| uint32_t reg = entry.first; |
| // Already handled the CFA register. |
| if (reg == CFA_REG) continue; |
| |
| AddressType* reg_ptr; |
| if (reg >= cur_regs->total_regs()) { |
| if (entry.second.type != DWARF_LOCATION_PSEUDO_REGISTER) { |
| // Skip this unknown register. |
| continue; |
| } |
| if (!eval_info.regs_info.regs->SetPseudoRegister(reg, entry.second.values[0])) { |
| last_error_.code = DWARF_ERROR_ILLEGAL_VALUE; |
| return false; |
| } |
| } else { |
| reg_ptr = eval_info.regs_info.Save(reg); |
| if (!EvalRegister(&entry.second, reg, reg_ptr, &eval_info)) { |
| return false; |
| } |
| } |
| } |
| |
| // Find the return address location. |
| if (eval_info.return_address_undefined) { |
| cur_regs->set_pc(0); |
| } else { |
| cur_regs->set_pc((*cur_regs)[cie->return_address_register]); |
| } |
| |
| // If the pc was set to zero, consider this the final frame. Exception: if |
| // this is the sigreturn frame, then we want to try to recover the real PC |
| // using the return address (from LR or the stack), so keep going. |
| *finished = (cur_regs->pc() == 0 && !cie->is_signal_frame) ? true : false; |
| |
| cur_regs->set_sp(eval_info.cfa); |
| |
| return true; |
| } |
| |
| template <typename AddressType> |
| bool DwarfSectionImpl<AddressType>::GetCfaLocationInfo(uint64_t pc, const DwarfFde* fde, |
| DwarfLocations* loc_regs, ArchEnum arch) { |
| DwarfCfa<AddressType> cfa(&memory_, fde, arch); |
| |
| // Look for the cached copy of the cie data. |
| auto reg_entry = cie_loc_regs_.find(fde->cie_offset); |
| if (reg_entry == cie_loc_regs_.end()) { |
| if (!cfa.GetLocationInfo(pc, fde->cie->cfa_instructions_offset, fde->cie->cfa_instructions_end, |
| loc_regs)) { |
| last_error_ = cfa.last_error(); |
| return false; |
| } |
| cie_loc_regs_[fde->cie_offset] = *loc_regs; |
| } |
| cfa.set_cie_loc_regs(&cie_loc_regs_[fde->cie_offset]); |
| if (!cfa.GetLocationInfo(pc, fde->cfa_instructions_offset, fde->cfa_instructions_end, loc_regs)) { |
| last_error_ = cfa.last_error(); |
| return false; |
| } |
| return true; |
| } |
| |
| template <typename AddressType> |
| bool DwarfSectionImpl<AddressType>::Log(uint8_t indent, uint64_t pc, const DwarfFde* fde, |
| ArchEnum arch) { |
| DwarfCfa<AddressType> cfa(&memory_, fde, arch); |
| |
| // Always print the cie information. |
| const DwarfCie* cie = fde->cie; |
| if (!cfa.Log(indent, pc, cie->cfa_instructions_offset, cie->cfa_instructions_end)) { |
| last_error_ = cfa.last_error(); |
| return false; |
| } |
| if (!cfa.Log(indent, pc, fde->cfa_instructions_offset, fde->cfa_instructions_end)) { |
| last_error_ = cfa.last_error(); |
| return false; |
| } |
| return true; |
| } |
| |
| template <typename AddressType> |
| bool DwarfSectionImpl<AddressType>::Init(uint64_t offset, uint64_t size, int64_t section_bias) { |
| section_bias_ = section_bias; |
| entries_offset_ = offset; |
| entries_end_ = offset + size; |
| |
| memory_.clear_func_offset(); |
| memory_.clear_text_offset(); |
| memory_.set_cur_offset(offset); |
| pc_offset_ = offset; |
| |
| return true; |
| } |
| |
| // Read CIE or FDE entry at the given offset, and set the offset to the following entry. |
| // The 'fde' argument is set only if we have seen an FDE entry. |
| template <typename AddressType> |
| bool DwarfSectionImpl<AddressType>::GetNextCieOrFde(uint64_t& next_entries_offset, |
| std::optional<DwarfFde>& fde_entry) { |
| const uint64_t start_offset = next_entries_offset; |
| |
| memory_.set_data_offset(entries_offset_); |
| memory_.set_cur_offset(next_entries_offset); |
| uint32_t value32; |
| if (!memory_.ReadBytes(&value32, sizeof(value32))) { |
| last_error_.code = DWARF_ERROR_MEMORY_INVALID; |
| last_error_.address = memory_.cur_offset(); |
| return false; |
| } |
| |
| uint64_t cie_offset; |
| uint8_t cie_fde_encoding; |
| bool entry_is_cie = false; |
| if (value32 == static_cast<uint32_t>(-1)) { |
| // 64 bit entry. |
| uint64_t value64; |
| if (!memory_.ReadBytes(&value64, sizeof(value64))) { |
| last_error_.code = DWARF_ERROR_MEMORY_INVALID; |
| last_error_.address = memory_.cur_offset(); |
| return false; |
| } |
| |
| next_entries_offset = memory_.cur_offset() + value64; |
| // Read the Cie Id of a Cie or the pointer of the Fde. |
| if (!memory_.ReadBytes(&value64, sizeof(value64))) { |
| last_error_.code = DWARF_ERROR_MEMORY_INVALID; |
| last_error_.address = memory_.cur_offset(); |
| return false; |
| } |
| |
| if (value64 == cie64_value_) { |
| entry_is_cie = true; |
| cie_fde_encoding = DW_EH_PE_udata8; |
| } else { |
| cie_offset = GetCieOffsetFromFde64(value64); |
| } |
| } else { |
| next_entries_offset = memory_.cur_offset() + value32; |
| |
| // 32 bit Cie |
| if (!memory_.ReadBytes(&value32, sizeof(value32))) { |
| last_error_.code = DWARF_ERROR_MEMORY_INVALID; |
| last_error_.address = memory_.cur_offset(); |
| return false; |
| } |
| |
| if (value32 == cie32_value_) { |
| entry_is_cie = true; |
| cie_fde_encoding = DW_EH_PE_udata4; |
| } else { |
| cie_offset = GetCieOffsetFromFde32(value32); |
| } |
| } |
| |
| if (entry_is_cie) { |
| auto entry = cie_entries_.find(start_offset); |
| if (entry == cie_entries_.end()) { |
| DwarfCie* cie = &cie_entries_[start_offset]; |
| cie->lsda_encoding = DW_EH_PE_omit; |
| cie->cfa_instructions_end = next_entries_offset; |
| cie->fde_address_encoding = cie_fde_encoding; |
| |
| if (!FillInCie(cie)) { |
| cie_entries_.erase(start_offset); |
| return false; |
| } |
| } |
| fde_entry.reset(); |
| } else { |
| fde_entry = DwarfFde{}; |
| fde_entry->cfa_instructions_end = next_entries_offset; |
| fde_entry->cie_offset = cie_offset; |
| if (!FillInFde(&*fde_entry)) { |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| template <typename AddressType> |
| void DwarfSectionImpl<AddressType>::GetFdes(std::vector<const DwarfFde*>* fdes) { |
| if (fde_index_.empty()) { |
| BuildFdeIndex(); |
| } |
| for (auto& it : fde_index_) { |
| fdes->push_back(GetFdeFromOffset(it.second)); |
| } |
| } |
| |
| template <typename AddressType> |
| const DwarfFde* DwarfSectionImpl<AddressType>::GetFdeFromPc(uint64_t pc) { |
| // Ensure that the binary search table is initialized. |
| if (fde_index_.empty()) { |
| BuildFdeIndex(); |
| } |
| |
| // Find the FDE offset in the binary search table. |
| auto comp = [](uint64_t pc, auto& entry) { return pc < entry.first; }; |
| auto it = std::upper_bound(fde_index_.begin(), fde_index_.end(), pc, comp); |
| if (it == fde_index_.end()) { |
| return nullptr; |
| } |
| |
| // Load the full FDE entry based on the offset. |
| const DwarfFde* fde = GetFdeFromOffset(/*fde_offset=*/it->second); |
| return fde != nullptr && fde->pc_start <= pc ? fde : nullptr; |
| } |
| |
| // Create binary search table to make FDE lookups fast (sorted by pc_end). |
| // We store only the FDE offset rather than the full entry to save memory. |
| // |
| // If there are overlapping entries, it inserts additional entries to ensure |
| // that one of the overlapping entries is found (it is undefined which one). |
| template <typename AddressType> |
| void DwarfSectionImpl<AddressType>::BuildFdeIndex() { |
| struct FdeInfo { |
| uint64_t pc_start, pc_end, fde_offset; |
| }; |
| std::vector<FdeInfo> fdes; |
| for (uint64_t offset = entries_offset_; offset < entries_end_;) { |
| const uint64_t initial_offset = offset; |
| std::optional<DwarfFde> fde; |
| if (!GetNextCieOrFde(offset, fde)) { |
| break; |
| } |
| if (fde.has_value() && /* defensive check */ (fde->pc_start < fde->pc_end)) { |
| fdes.push_back({fde->pc_start, fde->pc_end, initial_offset}); |
| } |
| if (offset <= initial_offset) { |
| break; // Jump back. Simply consider the processing done in this case. |
| } |
| } |
| std::sort(fdes.begin(), fdes.end(), [](const FdeInfo& a, const FdeInfo& b) { |
| return std::tie(a.pc_end, a.fde_offset) < std::tie(b.pc_end, b.fde_offset); |
| }); |
| |
| // If there are overlapping entries, ensure that we can always find one of them. |
| // For example, for entries: [300, 350) [400, 450) [100, 550) [600, 650) |
| // We add the following: [100, 300) [100, 400) |
| // Which ensures that the [100, 550) entry can be found in its whole range. |
| if (!fdes.empty()) { |
| FdeInfo filling = fdes.back(); // Entry with the minimal pc_start seen so far. |
| for (ssize_t i = fdes.size() - 1; i >= 0; i--) { // Iterate backwards. |
| uint64_t prev_pc_end = (i > 0) ? fdes[i - 1].pc_end : 0; |
| // If there is a gap between entries and the filling reaches the gap, fill it. |
| if (prev_pc_end < fdes[i].pc_start && filling.pc_start < fdes[i].pc_start) { |
| fdes.push_back({filling.pc_start, fdes[i].pc_start, filling.fde_offset}); |
| } |
| if (fdes[i].pc_start < filling.pc_start) { |
| filling = fdes[i]; |
| } |
| } |
| } |
| |
| // Copy data to the final binary search table (pc_end, fde_offset) and sort it. |
| fde_index_.reserve(fdes.size()); |
| for (const FdeInfo& it : fdes) { |
| fde_index_.emplace_back(it.pc_end, it.fde_offset); |
| } |
| if (!std::is_sorted(fde_index_.begin(), fde_index_.end())) { |
| std::sort(fde_index_.begin(), fde_index_.end()); |
| } |
| } |
| |
| // Explicitly instantiate DwarfSectionImpl |
| template class DwarfSectionImpl<uint32_t>; |
| template class DwarfSectionImpl<uint64_t>; |
| |
| // Explicitly instantiate DwarfDebugFrame |
| template class DwarfDebugFrame<uint32_t>; |
| template class DwarfDebugFrame<uint64_t>; |
| |
| // Explicitly instantiate DwarfEhFrame |
| template class DwarfEhFrame<uint32_t>; |
| template class DwarfEhFrame<uint64_t>; |
| |
| } // namespace unwindstack |