/* * Copyright (C) 2016 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 #include #include #include #include #include #include #include #include #include "DwarfCfa.h" #include "DwarfEncoding.h" #include "DwarfOp.h" namespace unwindstack { template constexpr typename DwarfCfa::process_func DwarfCfa::kCallbackTable[64]; template bool DwarfCfa::GetLocationInfo(uint64_t pc, uint64_t start_offset, uint64_t end_offset, dwarf_loc_regs_t* loc_regs) { if (cie_loc_regs_ != nullptr) { for (const auto& entry : *cie_loc_regs_) { (*loc_regs)[entry.first] = entry.second; } } last_error_.code = DWARF_ERROR_NONE; last_error_.address = 0; memory_->set_cur_offset(start_offset); uint64_t cfa_offset; cur_pc_ = fde_->pc_start; while ((cfa_offset = memory_->cur_offset()) < end_offset && cur_pc_ <= pc) { operands_.clear(); // Read the cfa information. uint8_t cfa_value; if (!memory_->ReadBytes(&cfa_value, 1)) { last_error_.code = DWARF_ERROR_MEMORY_INVALID; last_error_.address = memory_->cur_offset(); return false; } uint8_t cfa_low = cfa_value & 0x3f; // Check the 2 high bits. switch (cfa_value >> 6) { case 1: cur_pc_ += cfa_low * fde_->cie->code_alignment_factor; break; case 2: { uint64_t offset; if (!memory_->ReadULEB128(&offset)) { last_error_.code = DWARF_ERROR_MEMORY_INVALID; last_error_.address = memory_->cur_offset(); return false; } SignedType signed_offset = static_cast(offset) * fde_->cie->data_alignment_factor; (*loc_regs)[cfa_low] = {.type = DWARF_LOCATION_OFFSET, .values = {static_cast(signed_offset)}}; break; } case 3: { if (cie_loc_regs_ == nullptr) { log(0, "restore while processing cie"); last_error_.code = DWARF_ERROR_ILLEGAL_STATE; return false; } auto reg_entry = cie_loc_regs_->find(cfa_low); if (reg_entry == cie_loc_regs_->end()) { loc_regs->erase(cfa_low); } else { (*loc_regs)[cfa_low] = reg_entry->second; } break; } case 0: { const auto handle_func = DwarfCfa::kCallbackTable[cfa_low]; if (handle_func == nullptr) { last_error_.code = DWARF_ERROR_ILLEGAL_VALUE; return false; } const auto cfa = &DwarfCfaInfo::kTable[cfa_low]; for (size_t i = 0; i < cfa->num_operands; i++) { if (cfa->operands[i] == DW_EH_PE_block) { uint64_t block_length; if (!memory_->ReadULEB128(&block_length)) { last_error_.code = DWARF_ERROR_MEMORY_INVALID; last_error_.address = memory_->cur_offset(); return false; } operands_.push_back(block_length); memory_->set_cur_offset(memory_->cur_offset() + block_length); continue; } uint64_t value; if (!memory_->ReadEncodedValue(cfa->operands[i], &value)) { last_error_.code = DWARF_ERROR_MEMORY_INVALID; last_error_.address = memory_->cur_offset(); return false; } operands_.push_back(value); } if (!(this->*handle_func)(loc_regs)) { return false; } break; } } } return true; } template std::string DwarfCfa::GetOperandString(uint8_t operand, uint64_t value, uint64_t* cur_pc) { std::string string; switch (operand) { case DwarfCfaInfo::DWARF_DISPLAY_REGISTER: string = " register(" + std::to_string(value) + ")"; break; case DwarfCfaInfo::DWARF_DISPLAY_SIGNED_NUMBER: string += " " + std::to_string(static_cast(value)); break; case DwarfCfaInfo::DWARF_DISPLAY_ADVANCE_LOC: *cur_pc += value; // Fall through to log the value. case DwarfCfaInfo::DWARF_DISPLAY_NUMBER: string += " " + std::to_string(value); break; case DwarfCfaInfo::DWARF_DISPLAY_SET_LOC: *cur_pc = value; // Fall through to log the value. case DwarfCfaInfo::DWARF_DISPLAY_ADDRESS: if (std::is_same::value) { string += android::base::StringPrintf(" 0x%" PRIx32, static_cast(value)); } else { string += android::base::StringPrintf(" 0x%" PRIx64, static_cast(value)); } break; default: string = " unknown"; } return string; } template bool DwarfCfa::LogOffsetRegisterString(uint32_t indent, uint64_t cfa_offset, uint8_t reg) { uint64_t offset; if (!memory_->ReadULEB128(&offset)) { return false; } uint64_t end_offset = memory_->cur_offset(); memory_->set_cur_offset(cfa_offset); std::string raw_data = "Raw Data:"; for (uint64_t i = cfa_offset; i < end_offset; i++) { uint8_t value; if (!memory_->ReadBytes(&value, 1)) { return false; } raw_data += android::base::StringPrintf(" 0x%02x", value); } log(indent, "DW_CFA_offset register(%d) %" PRId64, reg, offset); log(indent, "%s", raw_data.c_str()); return true; } template bool DwarfCfa::LogInstruction(uint32_t indent, uint64_t cfa_offset, uint8_t op, uint64_t* cur_pc) { const auto* cfa = &DwarfCfaInfo::kTable[op]; if (cfa->name == nullptr) { log(indent, "Illegal"); log(indent, "Raw Data: 0x%02x", op); return true; } std::string log_string(cfa->name); std::vector expression_lines; for (size_t i = 0; i < cfa->num_operands; i++) { if (cfa->operands[i] == DW_EH_PE_block) { // This is a Dwarf Expression. uint64_t end_offset; if (!memory_->ReadULEB128(&end_offset)) { return false; } log_string += " " + std::to_string(end_offset); end_offset += memory_->cur_offset(); DwarfOp op(memory_, nullptr); op.GetLogInfo(memory_->cur_offset(), end_offset, &expression_lines); memory_->set_cur_offset(end_offset); } else { uint64_t value; if (!memory_->ReadEncodedValue(cfa->operands[i], &value)) { return false; } log_string += GetOperandString(cfa->display_operands[i], value, cur_pc); } } log(indent, "%s", log_string.c_str()); // Get the raw bytes of the data. uint64_t end_offset = memory_->cur_offset(); memory_->set_cur_offset(cfa_offset); std::string raw_data("Raw Data:"); for (uint64_t i = 0; i < end_offset - cfa_offset; i++) { uint8_t value; if (!memory_->ReadBytes(&value, 1)) { return false; } // Only show 10 raw bytes per line. if ((i % 10) == 0 && i != 0) { log(indent, "%s", raw_data.c_str()); raw_data.clear(); } if (raw_data.empty()) { raw_data = "Raw Data:"; } raw_data += android::base::StringPrintf(" 0x%02x", value); } if (!raw_data.empty()) { log(indent, "%s", raw_data.c_str()); } // Log any of the expression data. for (const auto line : expression_lines) { log(indent + 1, "%s", line.c_str()); } return true; } template bool DwarfCfa::Log(uint32_t indent, uint64_t pc, uint64_t load_bias, uint64_t start_offset, uint64_t end_offset) { memory_->set_cur_offset(start_offset); uint64_t cfa_offset; uint64_t cur_pc = fde_->pc_start; uint64_t old_pc = cur_pc; while ((cfa_offset = memory_->cur_offset()) < end_offset && cur_pc <= pc) { // Read the cfa information. uint8_t cfa_value; if (!memory_->ReadBytes(&cfa_value, 1)) { return false; } // Check the 2 high bits. uint8_t cfa_low = cfa_value & 0x3f; switch (cfa_value >> 6) { case 0: if (!LogInstruction(indent, cfa_offset, cfa_low, &cur_pc)) { return false; } break; case 1: log(indent, "DW_CFA_advance_loc %d", cfa_low); log(indent, "Raw Data: 0x%02x", cfa_value); cur_pc += cfa_low * fde_->cie->code_alignment_factor; break; case 2: if (!LogOffsetRegisterString(indent, cfa_offset, cfa_low)) { return false; } break; case 3: log(indent, "DW_CFA_restore register(%d)", cfa_low); log(indent, "Raw Data: 0x%02x", cfa_value); break; } if (cur_pc != old_pc) { log(indent, ""); log(indent, "PC 0x%" PRIx64, cur_pc + load_bias); } old_pc = cur_pc; } return true; } // Static data. template bool DwarfCfa::cfa_nop(dwarf_loc_regs_t*) { return true; } template bool DwarfCfa::cfa_set_loc(dwarf_loc_regs_t*) { AddressType cur_pc = cur_pc_; AddressType new_pc = operands_[0]; if (new_pc < cur_pc) { if (std::is_same::value) { log(0, "Warning: PC is moving backwards: old 0x%" PRIx32 " new 0x%" PRIx32, cur_pc, new_pc); } else { log(0, "Warning: PC is moving backwards: old 0x%" PRIx64 " new 0x%" PRIx64, cur_pc, new_pc); } } cur_pc_ = new_pc; return true; } template bool DwarfCfa::cfa_advance_loc(dwarf_loc_regs_t*) { cur_pc_ += operands_[0] * fde_->cie->code_alignment_factor; return true; } template bool DwarfCfa::cfa_offset(dwarf_loc_regs_t* loc_regs) { AddressType reg = operands_[0]; (*loc_regs)[reg] = {.type = DWARF_LOCATION_OFFSET, .values = {operands_[1]}}; return true; } template bool DwarfCfa::cfa_restore(dwarf_loc_regs_t* loc_regs) { AddressType reg = operands_[0]; if (cie_loc_regs_ == nullptr) { log(0, "restore while processing cie"); last_error_.code = DWARF_ERROR_ILLEGAL_STATE; return false; } auto reg_entry = cie_loc_regs_->find(reg); if (reg_entry == cie_loc_regs_->end()) { loc_regs->erase(reg); } else { (*loc_regs)[reg] = reg_entry->second; } return true; } template bool DwarfCfa::cfa_undefined(dwarf_loc_regs_t* loc_regs) { AddressType reg = operands_[0]; (*loc_regs)[reg] = {.type = DWARF_LOCATION_UNDEFINED}; return true; } template bool DwarfCfa::cfa_same_value(dwarf_loc_regs_t* loc_regs) { AddressType reg = operands_[0]; loc_regs->erase(reg); return true; } template bool DwarfCfa::cfa_register(dwarf_loc_regs_t* loc_regs) { AddressType reg = operands_[0]; AddressType reg_dst = operands_[1]; (*loc_regs)[reg] = {.type = DWARF_LOCATION_REGISTER, .values = {reg_dst}}; return true; } template bool DwarfCfa::cfa_remember_state(dwarf_loc_regs_t* loc_regs) { loc_reg_state_.push(*loc_regs); return true; } template bool DwarfCfa::cfa_restore_state(dwarf_loc_regs_t* loc_regs) { if (loc_reg_state_.size() == 0) { log(0, "Warning: Attempt to restore without remember."); return true; } *loc_regs = loc_reg_state_.top(); loc_reg_state_.pop(); return true; } template bool DwarfCfa::cfa_def_cfa(dwarf_loc_regs_t* loc_regs) { (*loc_regs)[CFA_REG] = {.type = DWARF_LOCATION_REGISTER, .values = {operands_[0], operands_[1]}}; return true; } template bool DwarfCfa::cfa_def_cfa_register(dwarf_loc_regs_t* loc_regs) { auto cfa_location = loc_regs->find(CFA_REG); if (cfa_location == loc_regs->end() || cfa_location->second.type != DWARF_LOCATION_REGISTER) { log(0, "Attempt to set new register, but cfa is not already set to a register."); last_error_.code = DWARF_ERROR_ILLEGAL_STATE; return false; } cfa_location->second.values[0] = operands_[0]; return true; } template bool DwarfCfa::cfa_def_cfa_offset(dwarf_loc_regs_t* loc_regs) { // Changing the offset if this is not a register is illegal. auto cfa_location = loc_regs->find(CFA_REG); if (cfa_location == loc_regs->end() || cfa_location->second.type != DWARF_LOCATION_REGISTER) { log(0, "Attempt to set offset, but cfa is not set to a register."); last_error_.code = DWARF_ERROR_ILLEGAL_STATE; return false; } cfa_location->second.values[1] = operands_[0]; return true; } template bool DwarfCfa::cfa_def_cfa_expression(dwarf_loc_regs_t* loc_regs) { // There is only one type of expression for CFA evaluation and the DWARF // specification is unclear whether it returns the address or the // dereferenced value. GDB expects the value, so will we. (*loc_regs)[CFA_REG] = {.type = DWARF_LOCATION_VAL_EXPRESSION, .values = {operands_[0], memory_->cur_offset()}}; return true; } template bool DwarfCfa::cfa_expression(dwarf_loc_regs_t* loc_regs) { AddressType reg = operands_[0]; (*loc_regs)[reg] = {.type = DWARF_LOCATION_EXPRESSION, .values = {operands_[1], memory_->cur_offset()}}; return true; } template bool DwarfCfa::cfa_offset_extended_sf(dwarf_loc_regs_t* loc_regs) { AddressType reg = operands_[0]; SignedType value = static_cast(operands_[1]) * fde_->cie->data_alignment_factor; (*loc_regs)[reg] = {.type = DWARF_LOCATION_OFFSET, .values = {static_cast(value)}}; return true; } template bool DwarfCfa::cfa_def_cfa_sf(dwarf_loc_regs_t* loc_regs) { SignedType offset = static_cast(operands_[1]) * fde_->cie->data_alignment_factor; (*loc_regs)[CFA_REG] = {.type = DWARF_LOCATION_REGISTER, .values = {operands_[0], static_cast(offset)}}; return true; } template bool DwarfCfa::cfa_def_cfa_offset_sf(dwarf_loc_regs_t* loc_regs) { // Changing the offset if this is not a register is illegal. auto cfa_location = loc_regs->find(CFA_REG); if (cfa_location == loc_regs->end() || cfa_location->second.type != DWARF_LOCATION_REGISTER) { log(0, "Attempt to set offset, but cfa is not set to a register."); last_error_.code = DWARF_ERROR_ILLEGAL_STATE; return false; } SignedType offset = static_cast(operands_[0]) * fde_->cie->data_alignment_factor; cfa_location->second.values[1] = static_cast(offset); return true; } template bool DwarfCfa::cfa_val_offset(dwarf_loc_regs_t* loc_regs) { AddressType reg = operands_[0]; SignedType offset = static_cast(operands_[1]) * fde_->cie->data_alignment_factor; (*loc_regs)[reg] = {.type = DWARF_LOCATION_VAL_OFFSET, .values = {static_cast(offset)}}; return true; } template bool DwarfCfa::cfa_val_offset_sf(dwarf_loc_regs_t* loc_regs) { AddressType reg = operands_[0]; SignedType offset = static_cast(operands_[1]) * fde_->cie->data_alignment_factor; (*loc_regs)[reg] = {.type = DWARF_LOCATION_VAL_OFFSET, .values = {static_cast(offset)}}; return true; } template bool DwarfCfa::cfa_val_expression(dwarf_loc_regs_t* loc_regs) { AddressType reg = operands_[0]; (*loc_regs)[reg] = {.type = DWARF_LOCATION_VAL_EXPRESSION, .values = {operands_[1], memory_->cur_offset()}}; return true; } template bool DwarfCfa::cfa_gnu_negative_offset_extended(dwarf_loc_regs_t* loc_regs) { AddressType reg = operands_[0]; SignedType offset = -static_cast(operands_[1]); (*loc_regs)[reg] = {.type = DWARF_LOCATION_OFFSET, .values = {static_cast(offset)}}; return true; } const DwarfCfaInfo::Info DwarfCfaInfo::kTable[64] = { { // 0x00 DW_CFA_nop "DW_CFA_nop", 2, 0, {}, {}, }, { "DW_CFA_set_loc", // 0x01 DW_CFA_set_loc 2, 1, {DW_EH_PE_absptr}, {DWARF_DISPLAY_SET_LOC}, }, { "DW_CFA_advance_loc1", // 0x02 DW_CFA_advance_loc1 2, 1, {DW_EH_PE_udata1}, {DWARF_DISPLAY_ADVANCE_LOC}, }, { "DW_CFA_advance_loc2", // 0x03 DW_CFA_advance_loc2 2, 1, {DW_EH_PE_udata2}, {DWARF_DISPLAY_ADVANCE_LOC}, }, { "DW_CFA_advance_loc4", // 0x04 DW_CFA_advance_loc4 2, 1, {DW_EH_PE_udata4}, {DWARF_DISPLAY_ADVANCE_LOC}, }, { "DW_CFA_offset_extended", // 0x05 DW_CFA_offset_extended 2, 2, {DW_EH_PE_uleb128, DW_EH_PE_uleb128}, {DWARF_DISPLAY_REGISTER, DWARF_DISPLAY_NUMBER}, }, { "DW_CFA_restore_extended", // 0x06 DW_CFA_restore_extended 2, 1, {DW_EH_PE_uleb128}, {DWARF_DISPLAY_REGISTER}, }, { "DW_CFA_undefined", // 0x07 DW_CFA_undefined 2, 1, {DW_EH_PE_uleb128}, {DWARF_DISPLAY_REGISTER}, }, { "DW_CFA_same_value", // 0x08 DW_CFA_same_value 2, 1, {DW_EH_PE_uleb128}, {DWARF_DISPLAY_REGISTER}, }, { "DW_CFA_register", // 0x09 DW_CFA_register 2, 2, {DW_EH_PE_uleb128, DW_EH_PE_uleb128}, {DWARF_DISPLAY_REGISTER, DWARF_DISPLAY_REGISTER}, }, { "DW_CFA_remember_state", // 0x0a DW_CFA_remember_state 2, 0, {}, {}, }, { "DW_CFA_restore_state", // 0x0b DW_CFA_restore_state 2, 0, {}, {}, }, { "DW_CFA_def_cfa", // 0x0c DW_CFA_def_cfa 2, 2, {DW_EH_PE_uleb128, DW_EH_PE_uleb128}, {DWARF_DISPLAY_REGISTER, DWARF_DISPLAY_NUMBER}, }, { "DW_CFA_def_cfa_register", // 0x0d DW_CFA_def_cfa_register 2, 1, {DW_EH_PE_uleb128}, {DWARF_DISPLAY_REGISTER}, }, { "DW_CFA_def_cfa_offset", // 0x0e DW_CFA_def_cfa_offset 2, 1, {DW_EH_PE_uleb128}, {DWARF_DISPLAY_NUMBER}, }, { "DW_CFA_def_cfa_expression", // 0x0f DW_CFA_def_cfa_expression 2, 1, {DW_EH_PE_block}, {DWARF_DISPLAY_EVAL_BLOCK}, }, { "DW_CFA_expression", // 0x10 DW_CFA_expression 2, 2, {DW_EH_PE_uleb128, DW_EH_PE_block}, {DWARF_DISPLAY_REGISTER, DWARF_DISPLAY_EVAL_BLOCK}, }, { "DW_CFA_offset_extended_sf", // 0x11 DW_CFA_offset_extend_sf 2, 2, {DW_EH_PE_uleb128, DW_EH_PE_sleb128}, {DWARF_DISPLAY_REGISTER, DWARF_DISPLAY_SIGNED_NUMBER}, }, { "DW_CFA_def_cfa_sf", // 0x12 DW_CFA_def_cfa_sf 2, 2, {DW_EH_PE_uleb128, DW_EH_PE_sleb128}, {DWARF_DISPLAY_REGISTER, DWARF_DISPLAY_SIGNED_NUMBER}, }, { "DW_CFA_def_cfa_offset_sf", // 0x13 DW_CFA_def_cfa_offset_sf 2, 1, {DW_EH_PE_sleb128}, {DWARF_DISPLAY_SIGNED_NUMBER}, }, { "DW_CFA_val_offset", // 0x14 DW_CFA_val_offset 2, 2, {DW_EH_PE_uleb128, DW_EH_PE_uleb128}, {DWARF_DISPLAY_REGISTER, DWARF_DISPLAY_NUMBER}, }, { "DW_CFA_val_offset_sf", // 0x15 DW_CFA_val_offset_sf 2, 2, {DW_EH_PE_uleb128, DW_EH_PE_sleb128}, {DWARF_DISPLAY_REGISTER, DWARF_DISPLAY_SIGNED_NUMBER}, }, { "DW_CFA_val_expression", // 0x16 DW_CFA_val_expression 2, 2, {DW_EH_PE_uleb128, DW_EH_PE_block}, {DWARF_DISPLAY_REGISTER, DWARF_DISPLAY_EVAL_BLOCK}, }, {nullptr, 0, 0, {}, {}}, // 0x17 illegal cfa {nullptr, 0, 0, {}, {}}, // 0x18 illegal cfa {nullptr, 0, 0, {}, {}}, // 0x19 illegal cfa {nullptr, 0, 0, {}, {}}, // 0x1a illegal cfa {nullptr, 0, 0, {}, {}}, // 0x1b illegal cfa {nullptr, 0, 0, {}, {}}, // 0x1c DW_CFA_lo_user (Treat as illegal) {nullptr, 0, 0, {}, {}}, // 0x1d illegal cfa {nullptr, 0, 0, {}, {}}, // 0x1e illegal cfa {nullptr, 0, 0, {}, {}}, // 0x1f illegal cfa {nullptr, 0, 0, {}, {}}, // 0x20 illegal cfa {nullptr, 0, 0, {}, {}}, // 0x21 illegal cfa {nullptr, 0, 0, {}, {}}, // 0x22 illegal cfa {nullptr, 0, 0, {}, {}}, // 0x23 illegal cfa {nullptr, 0, 0, {}, {}}, // 0x24 illegal cfa {nullptr, 0, 0, {}, {}}, // 0x25 illegal cfa {nullptr, 0, 0, {}, {}}, // 0x26 illegal cfa {nullptr, 0, 0, {}, {}}, // 0x27 illegal cfa {nullptr, 0, 0, {}, {}}, // 0x28 illegal cfa {nullptr, 0, 0, {}, {}}, // 0x29 illegal cfa {nullptr, 0, 0, {}, {}}, // 0x2a illegal cfa {nullptr, 0, 0, {}, {}}, // 0x2b illegal cfa {nullptr, 0, 0, {}, {}}, // 0x2c illegal cfa {nullptr, 0, 0, {}, {}}, // 0x2d DW_CFA_GNU_window_save (Treat as illegal) { "DW_CFA_GNU_args_size", // 0x2e DW_CFA_GNU_args_size 2, 1, {DW_EH_PE_uleb128}, {DWARF_DISPLAY_NUMBER}, }, { "DW_CFA_GNU_negative_offset_extended", // 0x2f DW_CFA_GNU_negative_offset_extended 2, 2, {DW_EH_PE_uleb128, DW_EH_PE_uleb128}, {DWARF_DISPLAY_REGISTER, DWARF_DISPLAY_NUMBER}, }, {nullptr, 0, 0, {}, {}}, // 0x31 illegal cfa {nullptr, 0, 0, {}, {}}, // 0x32 illegal cfa {nullptr, 0, 0, {}, {}}, // 0x33 illegal cfa {nullptr, 0, 0, {}, {}}, // 0x34 illegal cfa {nullptr, 0, 0, {}, {}}, // 0x35 illegal cfa {nullptr, 0, 0, {}, {}}, // 0x36 illegal cfa {nullptr, 0, 0, {}, {}}, // 0x37 illegal cfa {nullptr, 0, 0, {}, {}}, // 0x38 illegal cfa {nullptr, 0, 0, {}, {}}, // 0x39 illegal cfa {nullptr, 0, 0, {}, {}}, // 0x3a illegal cfa {nullptr, 0, 0, {}, {}}, // 0x3b illegal cfa {nullptr, 0, 0, {}, {}}, // 0x3c illegal cfa {nullptr, 0, 0, {}, {}}, // 0x3d illegal cfa {nullptr, 0, 0, {}, {}}, // 0x3e illegal cfa {nullptr, 0, 0, {}, {}}, // 0x3f DW_CFA_hi_user (Treat as illegal) }; // Explicitly instantiate DwarfCfa. template class DwarfCfa; template class DwarfCfa; } // namespace unwindstack