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platform_system_core/libunwindstack/DwarfSection.cpp
Christopher Ferris 2fcf4cf13e Add error propagation into Unwinder/Elf objects. 
The backtrace offline code uses these error codes to diagnose errors.
In addtion, I've had cases where seeing these errors would help diagnose
failures.

This also allows us to add a few features to indicate why an unwind
terminated (such as max frames exceeded).

Bug: 65682279

Test: Updated unit tests pass.
Change-Id: If82b5092698e8a194016d670efff1320f9b44d50
2018-01-24 17:50:46 -08:00

943 lines
28 KiB
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/*
* 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 <unwindstack/DwarfError.h>
#include <unwindstack/DwarfLocation.h>
#include <unwindstack/DwarfMemory.h>
#include <unwindstack/DwarfSection.h>
#include <unwindstack/DwarfStructs.h>
#include <unwindstack/Log.h>
#include <unwindstack/Memory.h>
#include <unwindstack/Regs.h>
#include "DwarfCfa.h"
#include "DwarfEncoding.h"
#include "DwarfOp.h"
#include "DwarfDebugFrame.h"
#include "DwarfEhFrame.h"
namespace unwindstack {
constexpr uint64_t DEX_PC_REG = 0x20444558;
DwarfSection::DwarfSection(Memory* memory) : memory_(memory) {}
const DwarfFde* DwarfSection::GetFdeFromPc(uint64_t pc) {
uint64_t fde_offset;
if (!GetFdeOffsetFromPc(pc, &fde_offset)) {
return nullptr;
}
const DwarfFde* fde = GetFdeFromOffset(fde_offset);
if (fde == nullptr) {
return nullptr;
}
// Guaranteed pc >= pc_start, need to check pc in the fde range.
if (pc < fde->pc_end) {
return fde;
}
last_error_.code = DWARF_ERROR_ILLEGAL_STATE;
return nullptr;
}
bool DwarfSection::Step(uint64_t pc, Regs* regs, Memory* process_memory, bool* finished) {
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.
dwarf_loc_regs_t loc_regs;
if (!GetCfaLocationInfo(pc, fde, &loc_regs)) {
return false;
}
// Now eval the actual registers.
return Eval(fde->cie, process_memory, loc_regs, regs, finished);
}
template <typename AddressType>
bool DwarfSectionImpl<AddressType>::EvalExpression(const DwarfLocation& loc, uint8_t version,
Memory* regular_memory, AddressType* value) {
DwarfOp<AddressType> op(&memory_, regular_memory);
// Need to evaluate the op data.
uint64_t start = loc.values[1];
uint64_t end = start + loc.values[0];
if (!op.Eval(start, end, version)) {
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);
return true;
}
template <typename AddressType>
struct EvalInfo {
const dwarf_loc_regs_t* loc_regs;
const DwarfCie* cie;
RegsImpl<AddressType>* cur_regs;
Memory* regular_memory;
AddressType cfa;
bool return_address_undefined = false;
uint64_t reg_map = 0;
AddressType reg_values[64];
};
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->cur_regs->total_regs()) {
last_error_.code = DWARF_ERROR_ILLEGAL_VALUE;
return false;
}
AddressType* cur_reg_ptr = &(*eval_info->cur_regs)[cur_reg];
const auto& entry = eval_info->loc_regs->find(cur_reg);
if (entry != eval_info->loc_regs->end()) {
if (!(eval_info->reg_map & (1 << cur_reg))) {
eval_info->reg_map |= 1 << cur_reg;
eval_info->reg_values[cur_reg] = *cur_reg_ptr;
if (!EvalRegister(&entry->second, cur_reg, cur_reg_ptr, eval_info)) {
return false;
}
}
// Use the register value from before any evaluations.
*reg_ptr = eval_info->reg_values[cur_reg] + loc->values[1];
} else {
*reg_ptr = *cur_reg_ptr + loc->values[1];
}
break;
}
case DWARF_LOCATION_EXPRESSION:
case DWARF_LOCATION_VAL_EXPRESSION: {
AddressType value;
if (!EvalExpression(*loc, eval_info->cie->version, regular_memory, &value)) {
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;
}
break;
}
case DWARF_LOCATION_UNDEFINED:
if (reg == eval_info->cie->return_address_register) {
eval_info->return_address_undefined = true;
}
default:
break;
}
return true;
}
template <typename AddressType>
bool DwarfSectionImpl<AddressType>::Eval(const DwarfCie* cie, Memory* regular_memory,
const dwarf_loc_regs_t& 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);
AddressType prev_cfa = regs->sp();
EvalInfo<AddressType> eval_info{
.loc_regs = &loc_regs, .cie = cie, .regular_memory = regular_memory, .cur_regs = 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;
}
// If the stack pointer register is the CFA, and the stack
// pointer register does not have any associated location
// information, use the current cfa value.
if (regs->sp_reg() == loc->values[0] && loc_regs.count(regs->sp_reg()) == 0) {
eval_info.cfa = prev_cfa;
} else {
eval_info.cfa = (*cur_regs)[loc->values[0]];
}
eval_info.cfa += loc->values[1];
break;
case DWARF_LOCATION_EXPRESSION:
case DWARF_LOCATION_VAL_EXPRESSION: {
AddressType value;
if (!EvalExpression(*loc, cie->version, regular_memory, &value)) {
return false;
}
if (loc->type == DWARF_LOCATION_EXPRESSION) {
if (!regular_memory->ReadFully(value, &eval_info.cfa, sizeof(AddressType))) {
last_error_.code = DWARF_ERROR_MEMORY_INVALID;
last_error_.address = value;
return false;
}
} else {
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;
AddressType dex_pc = 0;
if (reg == DEX_PC_REG) {
// Special register that indicates this is a dex pc.
dex_pc = 0;
reg_ptr = &dex_pc;
} else if (reg >= cur_regs->total_regs() || eval_info.reg_map & (1 << reg)) {
// Skip this unknown register, or a register that has already been
// processed.
continue;
} else {
reg_ptr = &(*cur_regs)[reg];
eval_info.reg_map |= 1 << reg;
eval_info.reg_values[reg] = *reg_ptr;
}
if (!EvalRegister(&entry.second, reg, reg_ptr, &eval_info)) {
return false;
}
if (reg == DEX_PC_REG) {
cur_regs->set_dex_pc(dex_pc);
}
}
// 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.
*finished = (cur_regs->pc() == 0) ? true : false;
cur_regs->set_sp(eval_info.cfa);
return true;
}
template <typename AddressType>
const DwarfCie* DwarfSectionImpl<AddressType>::GetCie(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_cur_offset(offset);
if (!FillInCie(cie)) {
// Erase the cached entry.
cie_entries_.erase(offset);
return nullptr;
}
return cie;
}
template <typename AddressType>
bool DwarfSectionImpl<AddressType>::FillInCie(DwarfCie* cie) {
uint32_t length32;
if (!memory_.ReadBytes(&length32, sizeof(length32))) {
last_error_.code = DWARF_ERROR_MEMORY_INVALID;
last_error_.address = memory_.cur_offset();
return false;
}
// Set the default for the lsda encoding.
cie->lsda_encoding = DW_EH_PE_omit;
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;
cie->fde_address_encoding = DW_EH_PE_sdata8;
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;
cie->fde_address_encoding = DW_EH_PE_sdata4;
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;
}
}
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) {
// 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) {
// Skip the Address Size field since we only use it for validation.
memory_.set_cur_offset(memory_.cur_offset() + 1);
// 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;
}
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;
}
}
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_cur_offset(offset);
if (!FillInFde(fde)) {
fde_entries_.erase(offset);
return nullptr;
}
return fde;
}
template <typename AddressType>
bool DwarfSectionImpl<AddressType>::FillInFde(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);
}
uint64_t cur_offset = memory_.cur_offset();
const DwarfCie* cie = GetCie(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);
if (!memory_.ReadEncodedValue<AddressType>(cie->fde_address_encoding & 0xf, &fde->pc_start)) {
last_error_.code = DWARF_ERROR_MEMORY_INVALID;
last_error_.address = memory_.cur_offset();
return false;
}
fde->pc_start = AdjustPcFromFde(fde->pc_start);
if (!memory_.ReadEncodedValue<AddressType>(cie->fde_address_encoding & 0xf, &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();
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>::GetCfaLocationInfo(uint64_t pc, const DwarfFde* fde,
dwarf_loc_regs_t* loc_regs) {
DwarfCfa<AddressType> cfa(&memory_, fde);
// 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, uint64_t load_bias,
const DwarfFde* fde) {
DwarfCfa<AddressType> cfa(&memory_, fde);
// Always print the cie information.
const DwarfCie* cie = fde->cie;
if (!cfa.Log(indent, pc, load_bias, cie->cfa_instructions_offset, cie->cfa_instructions_end)) {
last_error_ = cfa.last_error();
return false;
}
if (!cfa.Log(indent, pc, load_bias, 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) {
entries_offset_ = offset;
entries_end_ = offset + size;
memory_.clear_func_offset();
memory_.clear_text_offset();
memory_.set_data_offset(offset);
memory_.set_cur_offset(offset);
memory_.set_pc_offset(offset);
return CreateSortedFdeList();
}
template <typename AddressType>
bool DwarfSectionImpl<AddressType>::GetCieInfo(uint8_t* segment_size, uint8_t* encoding) {
uint8_t version;
if (!memory_.ReadBytes(&version, 1)) {
last_error_.code = DWARF_ERROR_MEMORY_INVALID;
last_error_.address = memory_.cur_offset();
return false;
}
// Read the augmentation string.
std::vector<char> aug_string;
char aug_value;
bool get_encoding = false;
do {
if (!memory_.ReadBytes(&aug_value, 1)) {
last_error_.code = DWARF_ERROR_MEMORY_INVALID;
last_error_.address = memory_.cur_offset();
return false;
}
if (aug_value == 'R') {
get_encoding = true;
}
aug_string.push_back(aug_value);
} while (aug_value != '\0');
if (version == 4) {
// Skip the Address Size field.
memory_.set_cur_offset(memory_.cur_offset() + 1);
// Read the segment size.
if (!memory_.ReadBytes(segment_size, 1)) {
last_error_.code = DWARF_ERROR_MEMORY_INVALID;
last_error_.address = memory_.cur_offset();
return false;
}
} else {
*segment_size = 0;
}
if (aug_string[0] != 'z' || !get_encoding) {
// No encoding
return true;
}
// Skip code alignment factor
uint8_t value;
do {
if (!memory_.ReadBytes(&value, 1)) {
last_error_.code = DWARF_ERROR_MEMORY_INVALID;
last_error_.address = memory_.cur_offset();
return false;
}
} while (value & 0x80);
// Skip data alignment factor
do {
if (!memory_.ReadBytes(&value, 1)) {
last_error_.code = DWARF_ERROR_MEMORY_INVALID;
last_error_.address = memory_.cur_offset();
return false;
}
} while (value & 0x80);
if (version == 1) {
// Skip return address register.
memory_.set_cur_offset(memory_.cur_offset() + 1);
} else {
// Skip return address register.
do {
if (!memory_.ReadBytes(&value, 1)) {
last_error_.code = DWARF_ERROR_MEMORY_INVALID;
last_error_.address = memory_.cur_offset();
return false;
}
} while (value & 0x80);
}
// Skip the augmentation length.
do {
if (!memory_.ReadBytes(&value, 1)) {
last_error_.code = DWARF_ERROR_MEMORY_INVALID;
last_error_.address = memory_.cur_offset();
return false;
}
} while (value & 0x80);
for (size_t i = 1; i < aug_string.size(); i++) {
if (aug_string[i] == 'R') {
if (!memory_.ReadBytes(encoding, 1)) {
last_error_.code = DWARF_ERROR_MEMORY_INVALID;
last_error_.address = memory_.cur_offset();
return false;
}
// Got the encoding, that's all we are looking for.
return true;
} else if (aug_string[i] == 'L') {
memory_.set_cur_offset(memory_.cur_offset() + 1);
} else if (aug_string[i] == 'P') {
uint8_t encoding;
if (!memory_.ReadBytes(&encoding, 1)) {
last_error_.code = DWARF_ERROR_MEMORY_INVALID;
last_error_.address = memory_.cur_offset();
return false;
}
uint64_t value;
if (!memory_.template ReadEncodedValue<AddressType>(encoding, &value)) {
last_error_.code = DWARF_ERROR_MEMORY_INVALID;
last_error_.address = memory_.cur_offset();
return false;
}
}
}
// It should be impossible to get here.
abort();
}
template <typename AddressType>
bool DwarfSectionImpl<AddressType>::AddFdeInfo(uint64_t entry_offset, uint8_t segment_size,
uint8_t encoding) {
if (segment_size != 0) {
memory_.set_cur_offset(memory_.cur_offset() + 1);
}
uint64_t start;
if (!memory_.template ReadEncodedValue<AddressType>(encoding & 0xf, &start)) {
last_error_.code = DWARF_ERROR_MEMORY_INVALID;
last_error_.address = memory_.cur_offset();
return false;
}
start = AdjustPcFromFde(start);
uint64_t length;
if (!memory_.template ReadEncodedValue<AddressType>(encoding & 0xf, &length)) {
last_error_.code = DWARF_ERROR_MEMORY_INVALID;
last_error_.address = memory_.cur_offset();
return false;
}
if (length != 0) {
fdes_.emplace_back(entry_offset, start, length);
}
return true;
}
template <typename AddressType>
bool DwarfSectionImpl<AddressType>::CreateSortedFdeList() {
memory_.set_cur_offset(entries_offset_);
// Loop through all of the entries and read just enough to create
// a sorted list of pcs.
// This code assumes that first comes the cie, then the fdes that
// it applies to.
uint64_t cie_offset = 0;
uint8_t address_encoding;
uint8_t segment_size;
while (memory_.cur_offset() < entries_end_) {
uint64_t cur_entry_offset = memory_.cur_offset();
// Figure out the entry length and type.
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 next_entry_offset;
if (value32 == static_cast<uint32_t>(-1)) {
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_entry_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_) {
// Cie 64 bit
address_encoding = DW_EH_PE_sdata8;
if (!GetCieInfo(&segment_size, &address_encoding)) {
return false;
}
cie_offset = cur_entry_offset;
} else {
uint64_t last_cie_offset = GetCieOffsetFromFde64(value64);
if (last_cie_offset != cie_offset) {
// This means that this Fde is not following the Cie.
last_error_.code = DWARF_ERROR_ILLEGAL_VALUE;
return false;
}
// Fde 64 bit
if (!AddFdeInfo(cur_entry_offset, segment_size, address_encoding)) {
return false;
}
}
} else {
next_entry_offset = memory_.cur_offset() + value32;
// Read the Cie Id of a Cie or the pointer of the Fde.
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_) {
// Cie 32 bit
address_encoding = DW_EH_PE_sdata4;
if (!GetCieInfo(&segment_size, &address_encoding)) {
return false;
}
cie_offset = cur_entry_offset;
} else {
uint64_t last_cie_offset = GetCieOffsetFromFde32(value32);
if (last_cie_offset != cie_offset) {
// This means that this Fde is not following the Cie.
last_error_.code = DWARF_ERROR_ILLEGAL_VALUE;
return false;
}
// Fde 32 bit
if (!AddFdeInfo(cur_entry_offset, segment_size, address_encoding)) {
return false;
}
}
}
if (next_entry_offset < memory_.cur_offset()) {
// Simply consider the processing done in this case.
break;
}
memory_.set_cur_offset(next_entry_offset);
}
// Sort the entries.
std::sort(fdes_.begin(), fdes_.end(), [](const FdeInfo& a, const FdeInfo& b) {
if (a.start == b.start) return a.end < b.end;
return a.start < b.start;
});
fde_count_ = fdes_.size();
return true;
}
template <typename AddressType>
bool DwarfSectionImpl<AddressType>::GetFdeOffsetFromPc(uint64_t pc, uint64_t* fde_offset) {
if (fde_count_ == 0) {
return false;
}
size_t first = 0;
size_t last = fde_count_;
while (first < last) {
size_t current = (first + last) / 2;
const FdeInfo* info = &fdes_[current];
if (pc >= info->start && pc <= info->end) {
*fde_offset = info->offset;
return true;
}
if (pc < info->start) {
last = current;
} else {
first = current + 1;
}
}
return false;
}
template <typename AddressType>
const DwarfFde* DwarfSectionImpl<AddressType>::GetFdeFromIndex(size_t index) {
if (index >= fdes_.size()) {
return nullptr;
}
return this->GetFdeFromOffset(fdes_[index].offset);
}
// 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
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