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Diffstat (limited to 'tools/profiler/lul/LulElf.cpp')
| -rw-r--r-- | tools/profiler/lul/LulElf.cpp | 915 |
1 files changed, 0 insertions, 915 deletions
diff --git a/tools/profiler/lul/LulElf.cpp b/tools/profiler/lul/LulElf.cpp deleted file mode 100644 index 6f90d5f13..000000000 --- a/tools/profiler/lul/LulElf.cpp +++ /dev/null @@ -1,915 +0,0 @@ -/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ -/* vim: set ts=8 sts=2 et sw=2 tw=80: */ - -// Copyright (c) 2006, 2011, 2012 Google Inc. -// All rights reserved. -// -// Redistribution and use in source and binary forms, with or without -// modification, are permitted provided that the following conditions are -// met: -// -// * Redistributions of source code must retain the above copyright -// notice, this list of conditions and the following disclaimer. -// * Redistributions in binary form must reproduce the above -// copyright notice, this list of conditions and the following disclaimer -// in the documentation and/or other materials provided with the -// distribution. -// * Neither the name of Google Inc. nor the names of its -// contributors may be used to endorse or promote products derived from -// this software without specific prior written permission. -// -// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS -// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT -// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR -// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT -// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, -// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT -// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, -// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY -// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT -// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE -// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. - -// Restructured in 2009 by: Jim Blandy <jimb@mozilla.com> <jimb@red-bean.com> - -// (derived from) -// dump_symbols.cc: implement google_breakpad::WriteSymbolFile: -// Find all the debugging info in a file and dump it as a Breakpad symbol file. -// -// dump_symbols.h: Read debugging information from an ELF file, and write -// it out as a Breakpad symbol file. - -// This file is derived from the following files in -// toolkit/crashreporter/google-breakpad: -// src/common/linux/dump_symbols.cc -// src/common/linux/elfutils.cc -// src/common/linux/file_id.cc - -#include <errno.h> -#include <fcntl.h> -#include <stdio.h> -#include <string.h> -#include <sys/mman.h> -#include <sys/stat.h> -#include <unistd.h> -#include <arpa/inet.h> - -#include <set> -#include <string> -#include <vector> - -#include "mozilla/Assertions.h" -#include "mozilla/Sprintf.h" - -#include "LulPlatformMacros.h" -#include "LulCommonExt.h" -#include "LulDwarfExt.h" -#include "LulElfInt.h" -#include "LulMainInt.h" - - -#if defined(LUL_PLAT_arm_android) && !defined(SHT_ARM_EXIDX) -// bionic and older glibsc don't define it -# define SHT_ARM_EXIDX (SHT_LOPROC + 1) -#endif - - -// This namespace contains helper functions. -namespace { - -using lul::DwarfCFIToModule; -using lul::FindElfSectionByName; -using lul::GetOffset; -using lul::IsValidElf; -using lul::Module; -using lul::UniqueStringUniverse; -using lul::scoped_ptr; -using lul::Summariser; -using std::string; -using std::vector; -using std::set; - -// -// FDWrapper -// -// Wrapper class to make sure opened file is closed. -// -class FDWrapper { - public: - explicit FDWrapper(int fd) : - fd_(fd) {} - ~FDWrapper() { - if (fd_ != -1) - close(fd_); - } - int get() { - return fd_; - } - int release() { - int fd = fd_; - fd_ = -1; - return fd; - } - private: - int fd_; -}; - -// -// MmapWrapper -// -// Wrapper class to make sure mapped regions are unmapped. -// -class MmapWrapper { - public: - MmapWrapper() : is_set_(false), base_(NULL), size_(0){} - ~MmapWrapper() { - if (is_set_ && base_ != NULL) { - MOZ_ASSERT(size_ > 0); - munmap(base_, size_); - } - } - void set(void *mapped_address, size_t mapped_size) { - is_set_ = true; - base_ = mapped_address; - size_ = mapped_size; - } - void release() { - MOZ_ASSERT(is_set_); - is_set_ = false; - base_ = NULL; - size_ = 0; - } - - private: - bool is_set_; - void *base_; - size_t size_; -}; - - -// Set NUM_DW_REGNAMES to be the number of Dwarf register names -// appropriate to the machine architecture given in HEADER. Return -// true on success, or false if HEADER's machine architecture is not -// supported. -template<typename ElfClass> -bool DwarfCFIRegisterNames(const typename ElfClass::Ehdr* elf_header, - unsigned int* num_dw_regnames) { - switch (elf_header->e_machine) { - case EM_386: - *num_dw_regnames = DwarfCFIToModule::RegisterNames::I386(); - return true; - case EM_ARM: - *num_dw_regnames = DwarfCFIToModule::RegisterNames::ARM(); - return true; - case EM_X86_64: - *num_dw_regnames = DwarfCFIToModule::RegisterNames::X86_64(); - return true; - default: - MOZ_ASSERT(0); - return false; - } -} - -template<typename ElfClass> -bool LoadDwarfCFI(const string& dwarf_filename, - const typename ElfClass::Ehdr* elf_header, - const char* section_name, - const typename ElfClass::Shdr* section, - const bool eh_frame, - const typename ElfClass::Shdr* got_section, - const typename ElfClass::Shdr* text_section, - const bool big_endian, - SecMap* smap, - uintptr_t text_bias, - UniqueStringUniverse* usu, - void (*log)(const char*)) { - // Find the appropriate set of register names for this file's - // architecture. - unsigned int num_dw_regs = 0; - if (!DwarfCFIRegisterNames<ElfClass>(elf_header, &num_dw_regs)) { - fprintf(stderr, "%s: unrecognized ELF machine architecture '%d';" - " cannot convert DWARF call frame information\n", - dwarf_filename.c_str(), elf_header->e_machine); - return false; - } - - const lul::Endianness endianness - = big_endian ? lul::ENDIANNESS_BIG : lul::ENDIANNESS_LITTLE; - - // Find the call frame information and its size. - const char* cfi = - GetOffset<ElfClass, char>(elf_header, section->sh_offset); - size_t cfi_size = section->sh_size; - - // Plug together the parser, handler, and their entourages. - - // Here's a summariser, which will receive the output of the - // parser, create summaries, and add them to |smap|. - Summariser summ(smap, text_bias, log); - - lul::ByteReader reader(endianness); - reader.SetAddressSize(ElfClass::kAddrSize); - - DwarfCFIToModule::Reporter module_reporter(log, dwarf_filename, section_name); - DwarfCFIToModule handler(num_dw_regs, &module_reporter, &reader, usu, &summ); - - // Provide the base addresses for .eh_frame encoded pointers, if - // possible. - reader.SetCFIDataBase(section->sh_addr, cfi); - if (got_section) - reader.SetDataBase(got_section->sh_addr); - if (text_section) - reader.SetTextBase(text_section->sh_addr); - - lul::CallFrameInfo::Reporter dwarf_reporter(log, dwarf_filename, - section_name); - lul::CallFrameInfo parser(cfi, cfi_size, - &reader, &handler, &dwarf_reporter, - eh_frame); - parser.Start(); - - return true; -} - -bool LoadELF(const string& obj_file, MmapWrapper* map_wrapper, - void** elf_header) { - int obj_fd = open(obj_file.c_str(), O_RDONLY); - if (obj_fd < 0) { - fprintf(stderr, "Failed to open ELF file '%s': %s\n", - obj_file.c_str(), strerror(errno)); - return false; - } - FDWrapper obj_fd_wrapper(obj_fd); - struct stat st; - if (fstat(obj_fd, &st) != 0 && st.st_size <= 0) { - fprintf(stderr, "Unable to fstat ELF file '%s': %s\n", - obj_file.c_str(), strerror(errno)); - return false; - } - // Mapping it read-only is good enough. In any case, mapping it - // read-write confuses Valgrind's debuginfo acquire/discard - // heuristics, making it hard to profile the profiler. - void *obj_base = mmap(nullptr, st.st_size, - PROT_READ, MAP_PRIVATE, obj_fd, 0); - if (obj_base == MAP_FAILED) { - fprintf(stderr, "Failed to mmap ELF file '%s': %s\n", - obj_file.c_str(), strerror(errno)); - return false; - } - map_wrapper->set(obj_base, st.st_size); - *elf_header = obj_base; - if (!IsValidElf(*elf_header)) { - fprintf(stderr, "Not a valid ELF file: %s\n", obj_file.c_str()); - return false; - } - return true; -} - -// Get the endianness of ELF_HEADER. If it's invalid, return false. -template<typename ElfClass> -bool ElfEndianness(const typename ElfClass::Ehdr* elf_header, - bool* big_endian) { - if (elf_header->e_ident[EI_DATA] == ELFDATA2LSB) { - *big_endian = false; - return true; - } - if (elf_header->e_ident[EI_DATA] == ELFDATA2MSB) { - *big_endian = true; - return true; - } - - fprintf(stderr, "bad data encoding in ELF header: %d\n", - elf_header->e_ident[EI_DATA]); - return false; -} - -// -// LoadSymbolsInfo -// -// Holds the state between the two calls to LoadSymbols() in case it's necessary -// to follow the .gnu_debuglink section and load debug information from a -// different file. -// -template<typename ElfClass> -class LoadSymbolsInfo { - public: - typedef typename ElfClass::Addr Addr; - - explicit LoadSymbolsInfo(const vector<string>& dbg_dirs) : - debug_dirs_(dbg_dirs), - has_loading_addr_(false) {} - - // Keeps track of which sections have been loaded so sections don't - // accidentally get loaded twice from two different files. - void LoadedSection(const string §ion) { - if (loaded_sections_.count(section) == 0) { - loaded_sections_.insert(section); - } else { - fprintf(stderr, "Section %s has already been loaded.\n", - section.c_str()); - } - } - - string debuglink_file() const { - return debuglink_file_; - } - - private: - const vector<string>& debug_dirs_; // Directories in which to - // search for the debug ELF file. - - string debuglink_file_; // Full path to the debug ELF file. - - bool has_loading_addr_; // Indicate if LOADING_ADDR_ is valid. - - set<string> loaded_sections_; // Tracks the Loaded ELF sections - // between calls to LoadSymbols(). -}; - -// Find the preferred loading address of the binary. -template<typename ElfClass> -typename ElfClass::Addr GetLoadingAddress( - const typename ElfClass::Phdr* program_headers, - int nheader) { - typedef typename ElfClass::Phdr Phdr; - - // For non-PIC executables (e_type == ET_EXEC), the load address is - // the start address of the first PT_LOAD segment. (ELF requires - // the segments to be sorted by load address.) For PIC executables - // and dynamic libraries (e_type == ET_DYN), this address will - // normally be zero. - for (int i = 0; i < nheader; ++i) { - const Phdr& header = program_headers[i]; - if (header.p_type == PT_LOAD) - return header.p_vaddr; - } - return 0; -} - -template<typename ElfClass> -bool LoadSymbols(const string& obj_file, - const bool big_endian, - const typename ElfClass::Ehdr* elf_header, - const bool read_gnu_debug_link, - LoadSymbolsInfo<ElfClass>* info, - SecMap* smap, - void* rx_avma, size_t rx_size, - UniqueStringUniverse* usu, - void (*log)(const char*)) { - typedef typename ElfClass::Phdr Phdr; - typedef typename ElfClass::Shdr Shdr; - - char buf[500]; - SprintfLiteral(buf, "LoadSymbols: BEGIN %s\n", obj_file.c_str()); - buf[sizeof(buf)-1] = 0; - log(buf); - - // This is how the text bias is calculated. - // BEGIN CALCULATE BIAS - uintptr_t loading_addr = GetLoadingAddress<ElfClass>( - GetOffset<ElfClass, Phdr>(elf_header, elf_header->e_phoff), - elf_header->e_phnum); - uintptr_t text_bias = ((uintptr_t)rx_avma) - loading_addr; - SprintfLiteral(buf, - "LoadSymbols: rx_avma=%llx, text_bias=%llx", - (unsigned long long int)(uintptr_t)rx_avma, - (unsigned long long int)text_bias); - buf[sizeof(buf)-1] = 0; - log(buf); - // END CALCULATE BIAS - - const Shdr* sections = - GetOffset<ElfClass, Shdr>(elf_header, elf_header->e_shoff); - const Shdr* section_names = sections + elf_header->e_shstrndx; - const char* names = - GetOffset<ElfClass, char>(elf_header, section_names->sh_offset); - const char *names_end = names + section_names->sh_size; - bool found_usable_info = false; - - // Dwarf Call Frame Information (CFI) is actually independent from - // the other DWARF debugging information, and can be used alone. - const Shdr* dwarf_cfi_section = - FindElfSectionByName<ElfClass>(".debug_frame", SHT_PROGBITS, - sections, names, names_end, - elf_header->e_shnum); - if (dwarf_cfi_section) { - // Ignore the return value of this function; even without call frame - // information, the other debugging information could be perfectly - // useful. - info->LoadedSection(".debug_frame"); - bool result = - LoadDwarfCFI<ElfClass>(obj_file, elf_header, ".debug_frame", - dwarf_cfi_section, false, 0, 0, big_endian, - smap, text_bias, usu, log); - found_usable_info = found_usable_info || result; - if (result) - log("LoadSymbols: read CFI from .debug_frame"); - } - - // Linux C++ exception handling information can also provide - // unwinding data. - const Shdr* eh_frame_section = - FindElfSectionByName<ElfClass>(".eh_frame", SHT_PROGBITS, - sections, names, names_end, - elf_header->e_shnum); - if (eh_frame_section) { - // Pointers in .eh_frame data may be relative to the base addresses of - // certain sections. Provide those sections if present. - const Shdr* got_section = - FindElfSectionByName<ElfClass>(".got", SHT_PROGBITS, - sections, names, names_end, - elf_header->e_shnum); - const Shdr* text_section = - FindElfSectionByName<ElfClass>(".text", SHT_PROGBITS, - sections, names, names_end, - elf_header->e_shnum); - info->LoadedSection(".eh_frame"); - // As above, ignore the return value of this function. - bool result = - LoadDwarfCFI<ElfClass>(obj_file, elf_header, ".eh_frame", - eh_frame_section, true, - got_section, text_section, big_endian, - smap, text_bias, usu, log); - found_usable_info = found_usable_info || result; - if (result) - log("LoadSymbols: read CFI from .eh_frame"); - } - - SprintfLiteral(buf, "LoadSymbols: END %s\n", obj_file.c_str()); - buf[sizeof(buf)-1] = 0; - log(buf); - - return found_usable_info; -} - -// Return the breakpad symbol file identifier for the architecture of -// ELF_HEADER. -template<typename ElfClass> -const char* ElfArchitecture(const typename ElfClass::Ehdr* elf_header) { - typedef typename ElfClass::Half Half; - Half arch = elf_header->e_machine; - switch (arch) { - case EM_386: return "x86"; - case EM_ARM: return "arm"; - case EM_MIPS: return "mips"; - case EM_PPC64: return "ppc64"; - case EM_PPC: return "ppc"; - case EM_S390: return "s390"; - case EM_SPARC: return "sparc"; - case EM_SPARCV9: return "sparcv9"; - case EM_X86_64: return "x86_64"; - default: return NULL; - } -} - -// Format the Elf file identifier in IDENTIFIER as a UUID with the -// dashes removed. -string FormatIdentifier(unsigned char identifier[16]) { - char identifier_str[40]; - lul::FileID::ConvertIdentifierToString( - identifier, - identifier_str, - sizeof(identifier_str)); - string id_no_dash; - for (int i = 0; identifier_str[i] != '\0'; ++i) - if (identifier_str[i] != '-') - id_no_dash += identifier_str[i]; - // Add an extra "0" by the end. PDB files on Windows have an 'age' - // number appended to the end of the file identifier; this isn't - // really used or necessary on other platforms, but be consistent. - id_no_dash += '0'; - return id_no_dash; -} - -// Return the non-directory portion of FILENAME: the portion after the -// last slash, or the whole filename if there are no slashes. -string BaseFileName(const string &filename) { - // Lots of copies! basename's behavior is less than ideal. - char *c_filename = strdup(filename.c_str()); - string base = basename(c_filename); - free(c_filename); - return base; -} - -template<typename ElfClass> -bool ReadSymbolDataElfClass(const typename ElfClass::Ehdr* elf_header, - const string& obj_filename, - const vector<string>& debug_dirs, - SecMap* smap, void* rx_avma, size_t rx_size, - UniqueStringUniverse* usu, - void (*log)(const char*)) { - typedef typename ElfClass::Ehdr Ehdr; - - unsigned char identifier[16]; - if (!lul - ::FileID::ElfFileIdentifierFromMappedFile(elf_header, identifier)) { - fprintf(stderr, "%s: unable to generate file identifier\n", - obj_filename.c_str()); - return false; - } - - const char *architecture = ElfArchitecture<ElfClass>(elf_header); - if (!architecture) { - fprintf(stderr, "%s: unrecognized ELF machine architecture: %d\n", - obj_filename.c_str(), elf_header->e_machine); - return false; - } - - // Figure out what endianness this file is. - bool big_endian; - if (!ElfEndianness<ElfClass>(elf_header, &big_endian)) - return false; - - string name = BaseFileName(obj_filename); - string os = "Linux"; - string id = FormatIdentifier(identifier); - - LoadSymbolsInfo<ElfClass> info(debug_dirs); - if (!LoadSymbols<ElfClass>(obj_filename, big_endian, elf_header, - !debug_dirs.empty(), &info, - smap, rx_avma, rx_size, usu, log)) { - const string debuglink_file = info.debuglink_file(); - if (debuglink_file.empty()) - return false; - - // Load debuglink ELF file. - fprintf(stderr, "Found debugging info in %s\n", debuglink_file.c_str()); - MmapWrapper debug_map_wrapper; - Ehdr* debug_elf_header = NULL; - if (!LoadELF(debuglink_file, &debug_map_wrapper, - reinterpret_cast<void**>(&debug_elf_header))) - return false; - // Sanity checks to make sure everything matches up. - const char *debug_architecture = - ElfArchitecture<ElfClass>(debug_elf_header); - if (!debug_architecture) { - fprintf(stderr, "%s: unrecognized ELF machine architecture: %d\n", - debuglink_file.c_str(), debug_elf_header->e_machine); - return false; - } - if (strcmp(architecture, debug_architecture)) { - fprintf(stderr, "%s with ELF machine architecture %s does not match " - "%s with ELF architecture %s\n", - debuglink_file.c_str(), debug_architecture, - obj_filename.c_str(), architecture); - return false; - } - - bool debug_big_endian; - if (!ElfEndianness<ElfClass>(debug_elf_header, &debug_big_endian)) - return false; - if (debug_big_endian != big_endian) { - fprintf(stderr, "%s and %s does not match in endianness\n", - obj_filename.c_str(), debuglink_file.c_str()); - return false; - } - - if (!LoadSymbols<ElfClass>(debuglink_file, debug_big_endian, - debug_elf_header, false, &info, - smap, rx_avma, rx_size, usu, log)) { - return false; - } - } - - return true; -} - -} // namespace (anon) - - -namespace lul { - -bool ReadSymbolDataInternal(const uint8_t* obj_file, - const string& obj_filename, - const vector<string>& debug_dirs, - SecMap* smap, void* rx_avma, size_t rx_size, - UniqueStringUniverse* usu, - void (*log)(const char*)) { - - if (!IsValidElf(obj_file)) { - fprintf(stderr, "Not a valid ELF file: %s\n", obj_filename.c_str()); - return false; - } - - int elfclass = ElfClass(obj_file); - if (elfclass == ELFCLASS32) { - return ReadSymbolDataElfClass<ElfClass32>( - reinterpret_cast<const Elf32_Ehdr*>(obj_file), - obj_filename, debug_dirs, smap, rx_avma, rx_size, usu, log); - } - if (elfclass == ELFCLASS64) { - return ReadSymbolDataElfClass<ElfClass64>( - reinterpret_cast<const Elf64_Ehdr*>(obj_file), - obj_filename, debug_dirs, smap, rx_avma, rx_size, usu, log); - } - - return false; -} - -bool ReadSymbolData(const string& obj_file, - const vector<string>& debug_dirs, - SecMap* smap, void* rx_avma, size_t rx_size, - UniqueStringUniverse* usu, - void (*log)(const char*)) { - MmapWrapper map_wrapper; - void* elf_header = NULL; - if (!LoadELF(obj_file, &map_wrapper, &elf_header)) - return false; - - return ReadSymbolDataInternal(reinterpret_cast<uint8_t*>(elf_header), - obj_file, debug_dirs, - smap, rx_avma, rx_size, usu, log); -} - - -namespace { - -template<typename ElfClass> -void FindElfClassSection(const char *elf_base, - const char *section_name, - typename ElfClass::Word section_type, - const void **section_start, - int *section_size) { - typedef typename ElfClass::Ehdr Ehdr; - typedef typename ElfClass::Shdr Shdr; - - MOZ_ASSERT(elf_base); - MOZ_ASSERT(section_start); - MOZ_ASSERT(section_size); - - MOZ_ASSERT(strncmp(elf_base, ELFMAG, SELFMAG) == 0); - - const Ehdr* elf_header = reinterpret_cast<const Ehdr*>(elf_base); - MOZ_ASSERT(elf_header->e_ident[EI_CLASS] == ElfClass::kClass); - - const Shdr* sections = - GetOffset<ElfClass,Shdr>(elf_header, elf_header->e_shoff); - const Shdr* section_names = sections + elf_header->e_shstrndx; - const char* names = - GetOffset<ElfClass,char>(elf_header, section_names->sh_offset); - const char *names_end = names + section_names->sh_size; - - const Shdr* section = - FindElfSectionByName<ElfClass>(section_name, section_type, - sections, names, names_end, - elf_header->e_shnum); - - if (section != NULL && section->sh_size > 0) { - *section_start = elf_base + section->sh_offset; - *section_size = section->sh_size; - } -} - -template<typename ElfClass> -void FindElfClassSegment(const char *elf_base, - typename ElfClass::Word segment_type, - const void **segment_start, - int *segment_size) { - typedef typename ElfClass::Ehdr Ehdr; - typedef typename ElfClass::Phdr Phdr; - - MOZ_ASSERT(elf_base); - MOZ_ASSERT(segment_start); - MOZ_ASSERT(segment_size); - - MOZ_ASSERT(strncmp(elf_base, ELFMAG, SELFMAG) == 0); - - const Ehdr* elf_header = reinterpret_cast<const Ehdr*>(elf_base); - MOZ_ASSERT(elf_header->e_ident[EI_CLASS] == ElfClass::kClass); - - const Phdr* phdrs = - GetOffset<ElfClass,Phdr>(elf_header, elf_header->e_phoff); - - for (int i = 0; i < elf_header->e_phnum; ++i) { - if (phdrs[i].p_type == segment_type) { - *segment_start = elf_base + phdrs[i].p_offset; - *segment_size = phdrs[i].p_filesz; - return; - } - } -} - -} // namespace (anon) - -bool IsValidElf(const void* elf_base) { - return strncmp(reinterpret_cast<const char*>(elf_base), - ELFMAG, SELFMAG) == 0; -} - -int ElfClass(const void* elf_base) { - const ElfW(Ehdr)* elf_header = - reinterpret_cast<const ElfW(Ehdr)*>(elf_base); - - return elf_header->e_ident[EI_CLASS]; -} - -bool FindElfSection(const void *elf_mapped_base, - const char *section_name, - uint32_t section_type, - const void **section_start, - int *section_size, - int *elfclass) { - MOZ_ASSERT(elf_mapped_base); - MOZ_ASSERT(section_start); - MOZ_ASSERT(section_size); - - *section_start = NULL; - *section_size = 0; - - if (!IsValidElf(elf_mapped_base)) - return false; - - int cls = ElfClass(elf_mapped_base); - if (elfclass) { - *elfclass = cls; - } - - const char* elf_base = - static_cast<const char*>(elf_mapped_base); - - if (cls == ELFCLASS32) { - FindElfClassSection<ElfClass32>(elf_base, section_name, section_type, - section_start, section_size); - return *section_start != NULL; - } else if (cls == ELFCLASS64) { - FindElfClassSection<ElfClass64>(elf_base, section_name, section_type, - section_start, section_size); - return *section_start != NULL; - } - - return false; -} - -bool FindElfSegment(const void *elf_mapped_base, - uint32_t segment_type, - const void **segment_start, - int *segment_size, - int *elfclass) { - MOZ_ASSERT(elf_mapped_base); - MOZ_ASSERT(segment_start); - MOZ_ASSERT(segment_size); - - *segment_start = NULL; - *segment_size = 0; - - if (!IsValidElf(elf_mapped_base)) - return false; - - int cls = ElfClass(elf_mapped_base); - if (elfclass) { - *elfclass = cls; - } - - const char* elf_base = - static_cast<const char*>(elf_mapped_base); - - if (cls == ELFCLASS32) { - FindElfClassSegment<ElfClass32>(elf_base, segment_type, - segment_start, segment_size); - return *segment_start != NULL; - } else if (cls == ELFCLASS64) { - FindElfClassSegment<ElfClass64>(elf_base, segment_type, - segment_start, segment_size); - return *segment_start != NULL; - } - - return false; -} - - -// (derived from) -// file_id.cc: Return a unique identifier for a file -// -// See file_id.h for documentation -// - -// ELF note name and desc are 32-bits word padded. -#define NOTE_PADDING(a) ((a + 3) & ~3) - -// These functions are also used inside the crashed process, so be safe -// and use the syscall/libc wrappers instead of direct syscalls or libc. - -template<typename ElfClass> -static bool ElfClassBuildIDNoteIdentifier(const void *section, int length, - uint8_t identifier[kMDGUIDSize]) { - typedef typename ElfClass::Nhdr Nhdr; - - const void* section_end = reinterpret_cast<const char*>(section) + length; - const Nhdr* note_header = reinterpret_cast<const Nhdr*>(section); - while (reinterpret_cast<const void *>(note_header) < section_end) { - if (note_header->n_type == NT_GNU_BUILD_ID) - break; - note_header = reinterpret_cast<const Nhdr*>( - reinterpret_cast<const char*>(note_header) + sizeof(Nhdr) + - NOTE_PADDING(note_header->n_namesz) + - NOTE_PADDING(note_header->n_descsz)); - } - if (reinterpret_cast<const void *>(note_header) >= section_end || - note_header->n_descsz == 0) { - return false; - } - - const char* build_id = reinterpret_cast<const char*>(note_header) + - sizeof(Nhdr) + NOTE_PADDING(note_header->n_namesz); - // Copy as many bits of the build ID as will fit - // into the GUID space. - memset(identifier, 0, kMDGUIDSize); - memcpy(identifier, build_id, - std::min(kMDGUIDSize, (size_t)note_header->n_descsz)); - - return true; -} - -// Attempt to locate a .note.gnu.build-id section in an ELF binary -// and copy as many bytes of it as will fit into |identifier|. -static bool FindElfBuildIDNote(const void *elf_mapped_base, - uint8_t identifier[kMDGUIDSize]) { - void* note_section; - int note_size, elfclass; - if ((!FindElfSegment(elf_mapped_base, PT_NOTE, - (const void**)¬e_section, ¬e_size, &elfclass) || - note_size == 0) && - (!FindElfSection(elf_mapped_base, ".note.gnu.build-id", SHT_NOTE, - (const void**)¬e_section, ¬e_size, &elfclass) || - note_size == 0)) { - return false; - } - - if (elfclass == ELFCLASS32) { - return ElfClassBuildIDNoteIdentifier<ElfClass32>(note_section, note_size, - identifier); - } else if (elfclass == ELFCLASS64) { - return ElfClassBuildIDNoteIdentifier<ElfClass64>(note_section, note_size, - identifier); - } - - return false; -} - -// Attempt to locate the .text section of an ELF binary and generate -// a simple hash by XORing the first page worth of bytes into |identifier|. -static bool HashElfTextSection(const void *elf_mapped_base, - uint8_t identifier[kMDGUIDSize]) { - void* text_section; - int text_size; - if (!FindElfSection(elf_mapped_base, ".text", SHT_PROGBITS, - (const void**)&text_section, &text_size, NULL) || - text_size == 0) { - return false; - } - - memset(identifier, 0, kMDGUIDSize); - const uint8_t* ptr = reinterpret_cast<const uint8_t*>(text_section); - const uint8_t* ptr_end = ptr + std::min(text_size, 4096); - while (ptr < ptr_end) { - for (unsigned i = 0; i < kMDGUIDSize; i++) - identifier[i] ^= ptr[i]; - ptr += kMDGUIDSize; - } - return true; -} - -// static -bool FileID::ElfFileIdentifierFromMappedFile(const void* base, - uint8_t identifier[kMDGUIDSize]) { - // Look for a build id note first. - if (FindElfBuildIDNote(base, identifier)) - return true; - - // Fall back on hashing the first page of the text section. - return HashElfTextSection(base, identifier); -} - -// static -void FileID::ConvertIdentifierToString(const uint8_t identifier[kMDGUIDSize], - char* buffer, int buffer_length) { - uint8_t identifier_swapped[kMDGUIDSize]; - - // Endian-ness swap to match dump processor expectation. - memcpy(identifier_swapped, identifier, kMDGUIDSize); - uint32_t* data1 = reinterpret_cast<uint32_t*>(identifier_swapped); - *data1 = htonl(*data1); - uint16_t* data2 = reinterpret_cast<uint16_t*>(identifier_swapped + 4); - *data2 = htons(*data2); - uint16_t* data3 = reinterpret_cast<uint16_t*>(identifier_swapped + 6); - *data3 = htons(*data3); - - int buffer_idx = 0; - for (unsigned int idx = 0; - (buffer_idx < buffer_length) && (idx < kMDGUIDSize); - ++idx) { - int hi = (identifier_swapped[idx] >> 4) & 0x0F; - int lo = (identifier_swapped[idx]) & 0x0F; - - if (idx == 4 || idx == 6 || idx == 8 || idx == 10) - buffer[buffer_idx++] = '-'; - - buffer[buffer_idx++] = (hi >= 10) ? 'A' + hi - 10 : '0' + hi; - buffer[buffer_idx++] = (lo >= 10) ? 'A' + lo - 10 : '0' + lo; - } - - // NULL terminate - buffer[(buffer_idx < buffer_length) ? buffer_idx : buffer_idx - 1] = 0; -} - -} // namespace lul |