| /* |
| * 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(); |
| |
| // Verify the request is not larger than the max size_t value. |
| if (gnu_debugdata_size_ > SIZE_MAX) { |
| return nullptr; |
| } |
| size_t initial_buffer_size; |
| if (__builtin_mul_overflow(5, gnu_debugdata_size_, &initial_buffer_size)) { |
| return nullptr; |
| } |
| |
| size_t buffer_increment; |
| if (__builtin_mul_overflow(2, gnu_debugdata_size_, &buffer_increment)) { |
| return nullptr; |
| } |
| |
| std::unique_ptr<uint8_t[]> src(new (std::nothrow) uint8_t[gnu_debugdata_size_]); |
| if (src.get() == nullptr) { |
| return nullptr; |
| } |
| |
| std::unique_ptr<MemoryBuffer> dst(new MemoryBuffer); |
| if (!dst->Resize(initial_buffer_size)) { |
| return nullptr; |
| } |
| |
| if (!memory_->ReadFully(gnu_debugdata_offset_, src.get(), gnu_debugdata_size_)) { |
| 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); |
| |
| int return_val; |
| size_t src_offset = 0; |
| size_t dst_offset = 0; |
| ECoderStatus status; |
| do { |
| size_t src_remaining = gnu_debugdata_size_ - src_offset; |
| size_t dst_remaining = dst->Size() - dst_offset; |
| if (dst_remaining < buffer_increment) { |
| size_t new_size; |
| if (__builtin_add_overflow(dst->Size(), buffer_increment, &new_size) || |
| !dst->Resize(new_size)) { |
| XzUnpacker_Free(&state); |
| return nullptr; |
| } |
| dst_remaining += buffer_increment; |
| } |
| 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)) { |
| return nullptr; |
| } |
| |
| // Shrink back down to the exact size. |
| if (!dst->Resize(dst_offset)) { |
| return nullptr; |
| } |
| |
| 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_start_ = phdr.p_vaddr; |
| if (__builtin_add_overflow(dynamic_vaddr_start_, phdr.p_memsz, &dynamic_vaddr_end_)) { |
| dynamic_offset_ = 0; |
| dynamic_vaddr_start_ = 0; |
| dynamic_vaddr_end_ = 0; |
| } |
| 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 (name == ".data") { |
| data_offset_ = shdr.sh_offset; |
| data_vaddr_start_ = shdr.sh_addr; |
| if (__builtin_add_overflow(data_vaddr_start_, shdr.sh_size, &data_vaddr_end_)) { |
| data_offset_ = 0; |
| data_vaddr_start_ = 0; |
| data_vaddr_end_ = 0; |
| } |
| } |
| } |
| } |
| } 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_vaddr_end_ - dynamic_vaddr_start_; |
| 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 |