4ca98e18a4
Due to a bug, an elf can have FDEs with a length of zero, while still having another FDE for the same pc with a non-zero length. The eh_frame_hdr can sometimes point to the zero length FDE, but it should have pointed to the non-zero length FDE. In order to fix this, if the eh_frame_hdr points at the zero length FDE then try and find the real FDE directly from eh_frame. The change cleans up and removes unused variables from DwarfEhFrameWithHdr and changes the objects so that all of the DwarfSection objects and DwarfEhFrameWithHdr object inherit from the same class. Add new unit tests to verify this functionality. Bug: 142483624 Test: Unit tests all pass. Change-Id: I128a916e3ba378931de7d44ee15e57e24d4073df
681 lines
22 KiB
C++
681 lines
22 KiB
C++
/*
|
|
* 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 <elf.h>
|
|
#include <stdint.h>
|
|
|
|
#include <memory>
|
|
#include <string>
|
|
#include <utility>
|
|
|
|
#include <7zCrc.h>
|
|
#include <Xz.h>
|
|
#include <XzCrc64.h>
|
|
|
|
#include <unwindstack/DwarfError.h>
|
|
#include <unwindstack/DwarfSection.h>
|
|
#include <unwindstack/ElfInterface.h>
|
|
#include <unwindstack/Log.h>
|
|
#include <unwindstack/Regs.h>
|
|
|
|
#include "DwarfDebugFrame.h"
|
|
#include "DwarfEhFrame.h"
|
|
#include "DwarfEhFrameWithHdr.h"
|
|
#include "MemoryBuffer.h"
|
|
#include "Symbols.h"
|
|
|
|
namespace unwindstack {
|
|
|
|
ElfInterface::~ElfInterface() {
|
|
for (auto symbol : symbols_) {
|
|
delete symbol;
|
|
}
|
|
}
|
|
|
|
bool ElfInterface::IsValidPc(uint64_t pc) {
|
|
if (!pt_loads_.empty()) {
|
|
for (auto& entry : pt_loads_) {
|
|
uint64_t start = entry.second.table_offset;
|
|
uint64_t end = start + entry.second.table_size;
|
|
if (pc >= start && pc < end) {
|
|
return true;
|
|
}
|
|
}
|
|
return false;
|
|
}
|
|
|
|
// No PT_LOAD data, look for a fde for this pc in the section data.
|
|
if (debug_frame_ != nullptr && debug_frame_->GetFdeFromPc(pc) != nullptr) {
|
|
return true;
|
|
}
|
|
|
|
if (eh_frame_ != nullptr && eh_frame_->GetFdeFromPc(pc) != nullptr) {
|
|
return true;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
Memory* ElfInterface::CreateGnuDebugdataMemory() {
|
|
if (gnu_debugdata_offset_ == 0 || gnu_debugdata_size_ == 0) {
|
|
return nullptr;
|
|
}
|
|
|
|
// TODO: Only call these initialization functions once.
|
|
CrcGenerateTable();
|
|
Crc64GenerateTable();
|
|
|
|
std::vector<uint8_t> src(gnu_debugdata_size_);
|
|
if (!memory_->ReadFully(gnu_debugdata_offset_, src.data(), gnu_debugdata_size_)) {
|
|
gnu_debugdata_offset_ = 0;
|
|
gnu_debugdata_size_ = static_cast<uint64_t>(-1);
|
|
return nullptr;
|
|
}
|
|
|
|
ISzAlloc alloc;
|
|
CXzUnpacker state;
|
|
alloc.Alloc = [](ISzAllocPtr, size_t size) { return malloc(size); };
|
|
alloc.Free = [](ISzAllocPtr, void* ptr) { return free(ptr); };
|
|
|
|
XzUnpacker_Construct(&state, &alloc);
|
|
|
|
std::unique_ptr<MemoryBuffer> dst(new MemoryBuffer);
|
|
int return_val;
|
|
size_t src_offset = 0;
|
|
size_t dst_offset = 0;
|
|
ECoderStatus status;
|
|
dst->Resize(5 * gnu_debugdata_size_);
|
|
do {
|
|
size_t src_remaining = src.size() - src_offset;
|
|
size_t dst_remaining = dst->Size() - dst_offset;
|
|
if (dst_remaining < 2 * gnu_debugdata_size_) {
|
|
dst->Resize(dst->Size() + 2 * gnu_debugdata_size_);
|
|
dst_remaining += 2 * gnu_debugdata_size_;
|
|
}
|
|
return_val = XzUnpacker_Code(&state, dst->GetPtr(dst_offset), &dst_remaining, &src[src_offset],
|
|
&src_remaining, true, CODER_FINISH_ANY, &status);
|
|
src_offset += src_remaining;
|
|
dst_offset += dst_remaining;
|
|
} while (return_val == SZ_OK && status == CODER_STATUS_NOT_FINISHED);
|
|
XzUnpacker_Free(&state);
|
|
if (return_val != SZ_OK || !XzUnpacker_IsStreamWasFinished(&state)) {
|
|
gnu_debugdata_offset_ = 0;
|
|
gnu_debugdata_size_ = static_cast<uint64_t>(-1);
|
|
return nullptr;
|
|
}
|
|
|
|
// Shrink back down to the exact size.
|
|
dst->Resize(dst_offset);
|
|
|
|
return dst.release();
|
|
}
|
|
|
|
template <typename AddressType>
|
|
void ElfInterface::InitHeadersWithTemplate() {
|
|
if (eh_frame_hdr_offset_ != 0) {
|
|
DwarfEhFrameWithHdr<AddressType>* eh_frame_hdr = new DwarfEhFrameWithHdr<AddressType>(memory_);
|
|
eh_frame_.reset(eh_frame_hdr);
|
|
if (!eh_frame_hdr->EhFrameInit(eh_frame_offset_, eh_frame_size_, eh_frame_section_bias_) ||
|
|
!eh_frame_->Init(eh_frame_hdr_offset_, eh_frame_hdr_size_, eh_frame_hdr_section_bias_)) {
|
|
eh_frame_.reset(nullptr);
|
|
}
|
|
}
|
|
|
|
if (eh_frame_.get() == nullptr && eh_frame_offset_ != 0) {
|
|
// If there is an eh_frame section without an eh_frame_hdr section,
|
|
// or using the frame hdr object failed to init.
|
|
eh_frame_.reset(new DwarfEhFrame<AddressType>(memory_));
|
|
if (!eh_frame_->Init(eh_frame_offset_, eh_frame_size_, eh_frame_section_bias_)) {
|
|
eh_frame_.reset(nullptr);
|
|
}
|
|
}
|
|
|
|
if (eh_frame_.get() == nullptr) {
|
|
eh_frame_hdr_offset_ = 0;
|
|
eh_frame_hdr_section_bias_ = 0;
|
|
eh_frame_hdr_size_ = static_cast<uint64_t>(-1);
|
|
eh_frame_offset_ = 0;
|
|
eh_frame_section_bias_ = 0;
|
|
eh_frame_size_ = static_cast<uint64_t>(-1);
|
|
}
|
|
|
|
if (debug_frame_offset_ != 0) {
|
|
debug_frame_.reset(new DwarfDebugFrame<AddressType>(memory_));
|
|
if (!debug_frame_->Init(debug_frame_offset_, debug_frame_size_, debug_frame_section_bias_)) {
|
|
debug_frame_.reset(nullptr);
|
|
debug_frame_offset_ = 0;
|
|
debug_frame_size_ = static_cast<uint64_t>(-1);
|
|
}
|
|
}
|
|
}
|
|
|
|
template <typename EhdrType, typename PhdrType, typename ShdrType>
|
|
bool ElfInterface::ReadAllHeaders(int64_t* load_bias) {
|
|
EhdrType ehdr;
|
|
if (!memory_->ReadFully(0, &ehdr, sizeof(ehdr))) {
|
|
last_error_.code = ERROR_MEMORY_INVALID;
|
|
last_error_.address = 0;
|
|
return false;
|
|
}
|
|
|
|
// If we have enough information that this is an elf file, then allow
|
|
// malformed program and section headers.
|
|
ReadProgramHeaders<EhdrType, PhdrType>(ehdr, load_bias);
|
|
ReadSectionHeaders<EhdrType, ShdrType>(ehdr);
|
|
return true;
|
|
}
|
|
|
|
template <typename EhdrType, typename PhdrType>
|
|
int64_t ElfInterface::GetLoadBias(Memory* memory) {
|
|
EhdrType ehdr;
|
|
if (!memory->ReadFully(0, &ehdr, sizeof(ehdr))) {
|
|
return false;
|
|
}
|
|
|
|
uint64_t offset = ehdr.e_phoff;
|
|
for (size_t i = 0; i < ehdr.e_phnum; i++, offset += ehdr.e_phentsize) {
|
|
PhdrType phdr;
|
|
if (!memory->ReadFully(offset, &phdr, sizeof(phdr))) {
|
|
return 0;
|
|
}
|
|
|
|
// Find the first executable load when looking for the load bias.
|
|
if (phdr.p_type == PT_LOAD && (phdr.p_flags & PF_X)) {
|
|
return static_cast<uint64_t>(phdr.p_vaddr) - phdr.p_offset;
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
template <typename EhdrType, typename PhdrType>
|
|
void ElfInterface::ReadProgramHeaders(const EhdrType& ehdr, int64_t* load_bias) {
|
|
uint64_t offset = ehdr.e_phoff;
|
|
bool first_exec_load_header = true;
|
|
for (size_t i = 0; i < ehdr.e_phnum; i++, offset += ehdr.e_phentsize) {
|
|
PhdrType phdr;
|
|
if (!memory_->ReadFully(offset, &phdr, sizeof(phdr))) {
|
|
return;
|
|
}
|
|
|
|
switch (phdr.p_type) {
|
|
case PT_LOAD:
|
|
{
|
|
if ((phdr.p_flags & PF_X) == 0) {
|
|
continue;
|
|
}
|
|
|
|
pt_loads_[phdr.p_offset] = LoadInfo{phdr.p_offset, phdr.p_vaddr,
|
|
static_cast<size_t>(phdr.p_memsz)};
|
|
// Only set the load bias from the first executable load header.
|
|
if (first_exec_load_header) {
|
|
*load_bias = static_cast<uint64_t>(phdr.p_vaddr) - phdr.p_offset;
|
|
}
|
|
first_exec_load_header = false;
|
|
break;
|
|
}
|
|
|
|
case PT_GNU_EH_FRAME:
|
|
// This is really the pointer to the .eh_frame_hdr section.
|
|
eh_frame_hdr_offset_ = phdr.p_offset;
|
|
eh_frame_hdr_section_bias_ = static_cast<uint64_t>(phdr.p_vaddr) - phdr.p_offset;
|
|
eh_frame_hdr_size_ = phdr.p_memsz;
|
|
break;
|
|
|
|
case PT_DYNAMIC:
|
|
dynamic_offset_ = phdr.p_offset;
|
|
dynamic_vaddr_ = phdr.p_vaddr;
|
|
dynamic_size_ = phdr.p_memsz;
|
|
break;
|
|
|
|
default:
|
|
HandleUnknownType(phdr.p_type, phdr.p_offset, phdr.p_filesz);
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
template <typename NhdrType>
|
|
std::string ElfInterface::ReadBuildID() {
|
|
// Ensure there is no overflow in any of the calulations below.
|
|
uint64_t tmp;
|
|
if (__builtin_add_overflow(gnu_build_id_offset_, gnu_build_id_size_, &tmp)) {
|
|
return "";
|
|
}
|
|
|
|
uint64_t offset = 0;
|
|
while (offset < gnu_build_id_size_) {
|
|
if (gnu_build_id_size_ - offset < sizeof(NhdrType)) {
|
|
return "";
|
|
}
|
|
NhdrType hdr;
|
|
if (!memory_->ReadFully(gnu_build_id_offset_ + offset, &hdr, sizeof(hdr))) {
|
|
return "";
|
|
}
|
|
offset += sizeof(hdr);
|
|
|
|
if (gnu_build_id_size_ - offset < hdr.n_namesz) {
|
|
return "";
|
|
}
|
|
if (hdr.n_namesz > 0) {
|
|
std::string name(hdr.n_namesz, '\0');
|
|
if (!memory_->ReadFully(gnu_build_id_offset_ + offset, &(name[0]), hdr.n_namesz)) {
|
|
return "";
|
|
}
|
|
|
|
// Trim trailing \0 as GNU is stored as a C string in the ELF file.
|
|
if (name.back() == '\0')
|
|
name.resize(name.size() - 1);
|
|
|
|
// Align hdr.n_namesz to next power multiple of 4. See man 5 elf.
|
|
offset += (hdr.n_namesz + 3) & ~3;
|
|
|
|
if (name == "GNU" && hdr.n_type == NT_GNU_BUILD_ID) {
|
|
if (gnu_build_id_size_ - offset < hdr.n_descsz || hdr.n_descsz == 0) {
|
|
return "";
|
|
}
|
|
std::string build_id(hdr.n_descsz, '\0');
|
|
if (memory_->ReadFully(gnu_build_id_offset_ + offset, &build_id[0], hdr.n_descsz)) {
|
|
return build_id;
|
|
}
|
|
return "";
|
|
}
|
|
}
|
|
// Align hdr.n_descsz to next power multiple of 4. See man 5 elf.
|
|
offset += (hdr.n_descsz + 3) & ~3;
|
|
}
|
|
return "";
|
|
}
|
|
|
|
template <typename EhdrType, typename ShdrType>
|
|
void ElfInterface::ReadSectionHeaders(const EhdrType& ehdr) {
|
|
uint64_t offset = ehdr.e_shoff;
|
|
uint64_t sec_offset = 0;
|
|
uint64_t sec_size = 0;
|
|
|
|
// Get the location of the section header names.
|
|
// If something is malformed in the header table data, we aren't going
|
|
// to terminate, we'll simply ignore this part.
|
|
ShdrType shdr;
|
|
if (ehdr.e_shstrndx < ehdr.e_shnum) {
|
|
uint64_t sh_offset = offset + ehdr.e_shstrndx * ehdr.e_shentsize;
|
|
if (memory_->ReadFully(sh_offset, &shdr, sizeof(shdr))) {
|
|
sec_offset = shdr.sh_offset;
|
|
sec_size = shdr.sh_size;
|
|
}
|
|
}
|
|
|
|
// Skip the first header, it's always going to be NULL.
|
|
offset += ehdr.e_shentsize;
|
|
for (size_t i = 1; i < ehdr.e_shnum; i++, offset += ehdr.e_shentsize) {
|
|
if (!memory_->ReadFully(offset, &shdr, sizeof(shdr))) {
|
|
return;
|
|
}
|
|
|
|
if (shdr.sh_type == SHT_SYMTAB || shdr.sh_type == SHT_DYNSYM) {
|
|
// Need to go get the information about the section that contains
|
|
// the string terminated names.
|
|
ShdrType str_shdr;
|
|
if (shdr.sh_link >= ehdr.e_shnum) {
|
|
continue;
|
|
}
|
|
uint64_t str_offset = ehdr.e_shoff + shdr.sh_link * ehdr.e_shentsize;
|
|
if (!memory_->ReadFully(str_offset, &str_shdr, sizeof(str_shdr))) {
|
|
continue;
|
|
}
|
|
if (str_shdr.sh_type != SHT_STRTAB) {
|
|
continue;
|
|
}
|
|
symbols_.push_back(new Symbols(shdr.sh_offset, shdr.sh_size, shdr.sh_entsize,
|
|
str_shdr.sh_offset, str_shdr.sh_size));
|
|
} else if (shdr.sh_type == SHT_PROGBITS && sec_size != 0) {
|
|
// Look for the .debug_frame and .gnu_debugdata.
|
|
if (shdr.sh_name < sec_size) {
|
|
std::string name;
|
|
if (memory_->ReadString(sec_offset + shdr.sh_name, &name)) {
|
|
if (name == ".debug_frame") {
|
|
debug_frame_offset_ = shdr.sh_offset;
|
|
debug_frame_size_ = shdr.sh_size;
|
|
debug_frame_section_bias_ = static_cast<uint64_t>(shdr.sh_addr) - shdr.sh_offset;
|
|
} else if (name == ".gnu_debugdata") {
|
|
gnu_debugdata_offset_ = shdr.sh_offset;
|
|
gnu_debugdata_size_ = shdr.sh_size;
|
|
} else if (name == ".eh_frame") {
|
|
eh_frame_offset_ = shdr.sh_offset;
|
|
eh_frame_section_bias_ = static_cast<uint64_t>(shdr.sh_addr) - shdr.sh_offset;
|
|
eh_frame_size_ = shdr.sh_size;
|
|
} else if (eh_frame_hdr_offset_ == 0 && name == ".eh_frame_hdr") {
|
|
eh_frame_hdr_offset_ = shdr.sh_offset;
|
|
eh_frame_hdr_section_bias_ = static_cast<uint64_t>(shdr.sh_addr) - shdr.sh_offset;
|
|
eh_frame_hdr_size_ = shdr.sh_size;
|
|
}
|
|
}
|
|
}
|
|
} else if (shdr.sh_type == SHT_STRTAB) {
|
|
// In order to read soname, keep track of address to offset mapping.
|
|
strtabs_.push_back(std::make_pair<uint64_t, uint64_t>(static_cast<uint64_t>(shdr.sh_addr),
|
|
static_cast<uint64_t>(shdr.sh_offset)));
|
|
} else if (shdr.sh_type == SHT_NOTE) {
|
|
if (shdr.sh_name < sec_size) {
|
|
std::string name;
|
|
if (memory_->ReadString(sec_offset + shdr.sh_name, &name) &&
|
|
name == ".note.gnu.build-id") {
|
|
gnu_build_id_offset_ = shdr.sh_offset;
|
|
gnu_build_id_size_ = shdr.sh_size;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
template <typename DynType>
|
|
std::string ElfInterface::GetSonameWithTemplate() {
|
|
if (soname_type_ == SONAME_INVALID) {
|
|
return "";
|
|
}
|
|
if (soname_type_ == SONAME_VALID) {
|
|
return soname_;
|
|
}
|
|
|
|
soname_type_ = SONAME_INVALID;
|
|
|
|
uint64_t soname_offset = 0;
|
|
uint64_t strtab_addr = 0;
|
|
uint64_t strtab_size = 0;
|
|
|
|
// Find the soname location from the dynamic headers section.
|
|
DynType dyn;
|
|
uint64_t offset = dynamic_offset_;
|
|
uint64_t max_offset = offset + dynamic_size_;
|
|
for (uint64_t offset = dynamic_offset_; offset < max_offset; offset += sizeof(DynType)) {
|
|
if (!memory_->ReadFully(offset, &dyn, sizeof(dyn))) {
|
|
last_error_.code = ERROR_MEMORY_INVALID;
|
|
last_error_.address = offset;
|
|
return "";
|
|
}
|
|
|
|
if (dyn.d_tag == DT_STRTAB) {
|
|
strtab_addr = dyn.d_un.d_ptr;
|
|
} else if (dyn.d_tag == DT_STRSZ) {
|
|
strtab_size = dyn.d_un.d_val;
|
|
} else if (dyn.d_tag == DT_SONAME) {
|
|
soname_offset = dyn.d_un.d_val;
|
|
} else if (dyn.d_tag == DT_NULL) {
|
|
break;
|
|
}
|
|
}
|
|
|
|
// Need to map the strtab address to the real offset.
|
|
for (const auto& entry : strtabs_) {
|
|
if (entry.first == strtab_addr) {
|
|
soname_offset = entry.second + soname_offset;
|
|
if (soname_offset >= entry.second + strtab_size) {
|
|
return "";
|
|
}
|
|
if (!memory_->ReadString(soname_offset, &soname_)) {
|
|
return "";
|
|
}
|
|
soname_type_ = SONAME_VALID;
|
|
return soname_;
|
|
}
|
|
}
|
|
return "";
|
|
}
|
|
|
|
template <typename SymType>
|
|
bool ElfInterface::GetFunctionNameWithTemplate(uint64_t addr, std::string* name,
|
|
uint64_t* func_offset) {
|
|
if (symbols_.empty()) {
|
|
return false;
|
|
}
|
|
|
|
for (const auto symbol : symbols_) {
|
|
if (symbol->GetName<SymType>(addr, memory_, name, func_offset)) {
|
|
return true;
|
|
}
|
|
}
|
|
return false;
|
|
}
|
|
|
|
template <typename SymType>
|
|
bool ElfInterface::GetGlobalVariableWithTemplate(const std::string& name, uint64_t* memory_address) {
|
|
if (symbols_.empty()) {
|
|
return false;
|
|
}
|
|
|
|
for (const auto symbol : symbols_) {
|
|
if (symbol->GetGlobal<SymType>(memory_, name, memory_address)) {
|
|
return true;
|
|
}
|
|
}
|
|
return false;
|
|
}
|
|
|
|
bool ElfInterface::Step(uint64_t pc, Regs* regs, Memory* process_memory, bool* finished) {
|
|
last_error_.code = ERROR_NONE;
|
|
last_error_.address = 0;
|
|
|
|
// Try the debug_frame first since it contains the most specific unwind
|
|
// information.
|
|
DwarfSection* debug_frame = debug_frame_.get();
|
|
if (debug_frame != nullptr && debug_frame->Step(pc, regs, process_memory, finished)) {
|
|
return true;
|
|
}
|
|
|
|
// Try the eh_frame next.
|
|
DwarfSection* eh_frame = eh_frame_.get();
|
|
if (eh_frame != nullptr && eh_frame->Step(pc, regs, process_memory, finished)) {
|
|
return true;
|
|
}
|
|
|
|
if (gnu_debugdata_interface_ != nullptr &&
|
|
gnu_debugdata_interface_->Step(pc, regs, process_memory, finished)) {
|
|
return true;
|
|
}
|
|
|
|
// Set the error code based on the first error encountered.
|
|
DwarfSection* section = nullptr;
|
|
if (debug_frame_ != nullptr) {
|
|
section = debug_frame_.get();
|
|
} else if (eh_frame_ != nullptr) {
|
|
section = eh_frame_.get();
|
|
} else if (gnu_debugdata_interface_ != nullptr) {
|
|
last_error_ = gnu_debugdata_interface_->last_error();
|
|
return false;
|
|
} else {
|
|
return false;
|
|
}
|
|
|
|
// Convert the DWARF ERROR to an external error.
|
|
DwarfErrorCode code = section->LastErrorCode();
|
|
switch (code) {
|
|
case DWARF_ERROR_NONE:
|
|
last_error_.code = ERROR_NONE;
|
|
break;
|
|
|
|
case DWARF_ERROR_MEMORY_INVALID:
|
|
last_error_.code = ERROR_MEMORY_INVALID;
|
|
last_error_.address = section->LastErrorAddress();
|
|
break;
|
|
|
|
case DWARF_ERROR_ILLEGAL_VALUE:
|
|
case DWARF_ERROR_ILLEGAL_STATE:
|
|
case DWARF_ERROR_STACK_INDEX_NOT_VALID:
|
|
case DWARF_ERROR_TOO_MANY_ITERATIONS:
|
|
case DWARF_ERROR_CFA_NOT_DEFINED:
|
|
case DWARF_ERROR_NO_FDES:
|
|
last_error_.code = ERROR_UNWIND_INFO;
|
|
break;
|
|
|
|
case DWARF_ERROR_NOT_IMPLEMENTED:
|
|
case DWARF_ERROR_UNSUPPORTED_VERSION:
|
|
last_error_.code = ERROR_UNSUPPORTED;
|
|
break;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
// This is an estimation of the size of the elf file using the location
|
|
// of the section headers and size. This assumes that the section headers
|
|
// are at the end of the elf file. If the elf has a load bias, the size
|
|
// will be too large, but this is acceptable.
|
|
template <typename EhdrType>
|
|
void ElfInterface::GetMaxSizeWithTemplate(Memory* memory, uint64_t* size) {
|
|
EhdrType ehdr;
|
|
if (!memory->ReadFully(0, &ehdr, sizeof(ehdr))) {
|
|
return;
|
|
}
|
|
if (ehdr.e_shnum == 0) {
|
|
return;
|
|
}
|
|
*size = ehdr.e_shoff + ehdr.e_shentsize * ehdr.e_shnum;
|
|
}
|
|
|
|
template <typename EhdrType, typename ShdrType>
|
|
bool GetBuildIDInfo(Memory* memory, uint64_t* build_id_offset, uint64_t* build_id_size) {
|
|
EhdrType ehdr;
|
|
if (!memory->ReadFully(0, &ehdr, sizeof(ehdr))) {
|
|
return false;
|
|
}
|
|
|
|
uint64_t offset = ehdr.e_shoff;
|
|
uint64_t sec_offset;
|
|
uint64_t sec_size;
|
|
ShdrType shdr;
|
|
if (ehdr.e_shstrndx >= ehdr.e_shnum) {
|
|
return false;
|
|
}
|
|
|
|
uint64_t sh_offset = offset + ehdr.e_shstrndx * ehdr.e_shentsize;
|
|
if (!memory->ReadFully(sh_offset, &shdr, sizeof(shdr))) {
|
|
return false;
|
|
}
|
|
sec_offset = shdr.sh_offset;
|
|
sec_size = shdr.sh_size;
|
|
|
|
// Skip the first header, it's always going to be NULL.
|
|
offset += ehdr.e_shentsize;
|
|
for (size_t i = 1; i < ehdr.e_shnum; i++, offset += ehdr.e_shentsize) {
|
|
if (!memory->ReadFully(offset, &shdr, sizeof(shdr))) {
|
|
return false;
|
|
}
|
|
std::string name;
|
|
if (shdr.sh_type == SHT_NOTE && shdr.sh_name < sec_size &&
|
|
memory->ReadString(sec_offset + shdr.sh_name, &name) && name == ".note.gnu.build-id") {
|
|
*build_id_offset = shdr.sh_offset;
|
|
*build_id_size = shdr.sh_size;
|
|
return true;
|
|
}
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
template <typename EhdrType, typename ShdrType, typename NhdrType>
|
|
std::string ElfInterface::ReadBuildIDFromMemory(Memory* memory) {
|
|
uint64_t note_offset;
|
|
uint64_t note_size;
|
|
if (!GetBuildIDInfo<EhdrType, ShdrType>(memory, ¬e_offset, ¬e_size)) {
|
|
return "";
|
|
}
|
|
|
|
// Ensure there is no overflow in any of the calculations below.
|
|
uint64_t tmp;
|
|
if (__builtin_add_overflow(note_offset, note_size, &tmp)) {
|
|
return "";
|
|
}
|
|
|
|
uint64_t offset = 0;
|
|
while (offset < note_size) {
|
|
if (note_size - offset < sizeof(NhdrType)) {
|
|
return "";
|
|
}
|
|
NhdrType hdr;
|
|
if (!memory->ReadFully(note_offset + offset, &hdr, sizeof(hdr))) {
|
|
return "";
|
|
}
|
|
offset += sizeof(hdr);
|
|
|
|
if (note_size - offset < hdr.n_namesz) {
|
|
return "";
|
|
}
|
|
if (hdr.n_namesz > 0) {
|
|
std::string name(hdr.n_namesz, '\0');
|
|
if (!memory->ReadFully(note_offset + offset, &(name[0]), hdr.n_namesz)) {
|
|
return "";
|
|
}
|
|
|
|
// Trim trailing \0 as GNU is stored as a C string in the ELF file.
|
|
if (name.back() == '\0') name.resize(name.size() - 1);
|
|
|
|
// Align hdr.n_namesz to next power multiple of 4. See man 5 elf.
|
|
offset += (hdr.n_namesz + 3) & ~3;
|
|
|
|
if (name == "GNU" && hdr.n_type == NT_GNU_BUILD_ID) {
|
|
if (note_size - offset < hdr.n_descsz || hdr.n_descsz == 0) {
|
|
return "";
|
|
}
|
|
std::string build_id(hdr.n_descsz - 1, '\0');
|
|
if (memory->ReadFully(note_offset + offset, &build_id[0], hdr.n_descsz)) {
|
|
return build_id;
|
|
}
|
|
return "";
|
|
}
|
|
}
|
|
// Align hdr.n_descsz to next power multiple of 4. See man 5 elf.
|
|
offset += (hdr.n_descsz + 3) & ~3;
|
|
}
|
|
return "";
|
|
}
|
|
|
|
// Instantiate all of the needed template functions.
|
|
template void ElfInterface::InitHeadersWithTemplate<uint32_t>();
|
|
template void ElfInterface::InitHeadersWithTemplate<uint64_t>();
|
|
|
|
template bool ElfInterface::ReadAllHeaders<Elf32_Ehdr, Elf32_Phdr, Elf32_Shdr>(int64_t*);
|
|
template bool ElfInterface::ReadAllHeaders<Elf64_Ehdr, Elf64_Phdr, Elf64_Shdr>(int64_t*);
|
|
|
|
template void ElfInterface::ReadProgramHeaders<Elf32_Ehdr, Elf32_Phdr>(const Elf32_Ehdr&, int64_t*);
|
|
template void ElfInterface::ReadProgramHeaders<Elf64_Ehdr, Elf64_Phdr>(const Elf64_Ehdr&, int64_t*);
|
|
|
|
template void ElfInterface::ReadSectionHeaders<Elf32_Ehdr, Elf32_Shdr>(const Elf32_Ehdr&);
|
|
template void ElfInterface::ReadSectionHeaders<Elf64_Ehdr, Elf64_Shdr>(const Elf64_Ehdr&);
|
|
|
|
template std::string ElfInterface::ReadBuildID<Elf32_Nhdr>();
|
|
template std::string ElfInterface::ReadBuildID<Elf64_Nhdr>();
|
|
|
|
template std::string ElfInterface::GetSonameWithTemplate<Elf32_Dyn>();
|
|
template std::string ElfInterface::GetSonameWithTemplate<Elf64_Dyn>();
|
|
|
|
template bool ElfInterface::GetFunctionNameWithTemplate<Elf32_Sym>(uint64_t, std::string*,
|
|
uint64_t*);
|
|
template bool ElfInterface::GetFunctionNameWithTemplate<Elf64_Sym>(uint64_t, std::string*,
|
|
uint64_t*);
|
|
|
|
template bool ElfInterface::GetGlobalVariableWithTemplate<Elf32_Sym>(const std::string&, uint64_t*);
|
|
template bool ElfInterface::GetGlobalVariableWithTemplate<Elf64_Sym>(const std::string&, uint64_t*);
|
|
|
|
template void ElfInterface::GetMaxSizeWithTemplate<Elf32_Ehdr>(Memory*, uint64_t*);
|
|
template void ElfInterface::GetMaxSizeWithTemplate<Elf64_Ehdr>(Memory*, uint64_t*);
|
|
|
|
template int64_t ElfInterface::GetLoadBias<Elf32_Ehdr, Elf32_Phdr>(Memory*);
|
|
template int64_t ElfInterface::GetLoadBias<Elf64_Ehdr, Elf64_Phdr>(Memory*);
|
|
|
|
template std::string ElfInterface::ReadBuildIDFromMemory<Elf32_Ehdr, Elf32_Shdr, Elf32_Nhdr>(
|
|
Memory*);
|
|
template std::string ElfInterface::ReadBuildIDFromMemory<Elf64_Ehdr, Elf64_Shdr, Elf64_Nhdr>(
|
|
Memory*);
|
|
|
|
} // namespace unwindstack
|