| // binary.cc -- binary input files for gold |
| |
| // Copyright (C) 2008-2021 Free Software Foundation, Inc. |
| // Written by Ian Lance Taylor <iant@google.com>. |
| |
| // This file is part of gold. |
| |
| // This program is free software; you can redistribute it and/or modify |
| // it under the terms of the GNU General Public License as published by |
| // the Free Software Foundation; either version 3 of the License, or |
| // (at your option) any later version. |
| |
| // This program is distributed in the hope that it will be useful, |
| // but WITHOUT ANY WARRANTY; without even the implied warranty of |
| // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| // GNU General Public License for more details. |
| |
| // You should have received a copy of the GNU General Public License |
| // along with this program; if not, write to the Free Software |
| // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, |
| // MA 02110-1301, USA. |
| |
| #include "gold.h" |
| |
| #include <cerrno> |
| #include <cstring> |
| |
| #include "elfcpp.h" |
| #include "stringpool.h" |
| #include "fileread.h" |
| #include "output.h" |
| #include "binary.h" |
| |
| // safe-ctype.h interferes with macros defined by the system <ctype.h>. |
| // Some C++ system headers might include <ctype.h> and rely on its macro |
| // definitions being intact. So make sure that safe-ctype.h is included |
| // only after any C++ system headers, whether directly here (above) or via |
| // other local header files (e.g. #include <string> in "binary.h"). |
| #include "safe-ctype.h" |
| |
| // Support for reading binary files as input. These become blobs in |
| // the final output. These files are treated as though they have a |
| // single .data section and define three symbols: |
| // _binary_FILENAME_start, _binary_FILENAME_end, _binary_FILENAME_size. |
| // The FILENAME is the name of the input file, with any |
| // non-alphanumeric character changed to an underscore. |
| |
| // We implement this by creating an ELF file in memory. |
| |
| namespace gold |
| { |
| |
| // class Binary_to_elf. |
| |
| Binary_to_elf::Binary_to_elf(elfcpp::EM machine, int size, bool big_endian, |
| const std::string& filename) |
| : elf_machine_(machine), size_(size), big_endian_(big_endian), |
| filename_(filename), data_(NULL), filesize_(0) |
| { |
| } |
| |
| Binary_to_elf::~Binary_to_elf() |
| { |
| if (this->data_ != NULL) |
| delete[] this->data_; |
| } |
| |
| // Given FILENAME, create a buffer which looks like an ELF file with |
| // the contents of FILENAME as the contents of the only section. The |
| // TASK parameters is mainly for debugging, and records who holds |
| // locks. |
| |
| bool |
| Binary_to_elf::convert(const Task* task) |
| { |
| if (this->size_ == 32) |
| { |
| if (!this->big_endian_) |
| { |
| #ifdef HAVE_TARGET_32_LITTLE |
| return this->sized_convert<32, false>(task); |
| #else |
| gold_unreachable(); |
| #endif |
| } |
| else |
| { |
| #ifdef HAVE_TARGET_32_BIG |
| return this->sized_convert<32, true>(task); |
| #else |
| gold_unreachable(); |
| #endif |
| } |
| } |
| else if (this->size_ == 64) |
| { |
| if (!this->big_endian_) |
| { |
| #ifdef HAVE_TARGET_64_LITTLE |
| return this->sized_convert<64, false>(task); |
| #else |
| gold_unreachable(); |
| #endif |
| } |
| else |
| { |
| #ifdef HAVE_TARGET_64_BIG |
| return this->sized_convert<64, true>(task); |
| #else |
| gold_unreachable(); |
| #endif |
| } |
| } |
| else |
| gold_unreachable(); |
| } |
| |
| // We are going to create: |
| // * The ELF file header. |
| // * Five sections: null section, .data, .symtab, .strtab, .shstrtab |
| // * The contents of the file. |
| // * Four symbols: null, begin, end, size. |
| // * Three symbol names. |
| // * Four section names. |
| |
| template<int size, bool big_endian> |
| bool |
| Binary_to_elf::sized_convert(const Task* task) |
| { |
| // Read the input file. |
| |
| File_read f; |
| if (!f.open(task, this->filename_)) |
| { |
| gold_error(_("cannot open %s: %s:"), this->filename_.c_str(), |
| strerror(errno)); |
| return false; |
| } |
| |
| section_size_type filesize = convert_to_section_size_type(f.filesize()); |
| const unsigned char* fileview; |
| if (filesize == 0) |
| fileview = NULL; |
| else |
| fileview = f.get_view(0, 0, filesize, false, false); |
| |
| unsigned int align; |
| if (size == 32) |
| align = 4; |
| else if (size == 64) |
| align = 8; |
| else |
| gold_unreachable(); |
| section_size_type aligned_filesize = align_address(filesize, align); |
| |
| // Build the stringpool for the symbol table. |
| |
| std::string mangled_name = this->filename_; |
| for (std::string::iterator p = mangled_name.begin(); |
| p != mangled_name.end(); |
| ++p) |
| if (!ISALNUM(*p)) |
| *p = '_'; |
| mangled_name = "_binary_" + mangled_name; |
| std::string start_symbol_name = mangled_name + "_start"; |
| std::string end_symbol_name = mangled_name + "_end"; |
| std::string size_symbol_name = mangled_name + "_size"; |
| |
| Stringpool strtab; |
| strtab.add(start_symbol_name.c_str(), false, NULL); |
| strtab.add(end_symbol_name.c_str(), false, NULL); |
| strtab.add(size_symbol_name.c_str(), false, NULL); |
| strtab.set_string_offsets(); |
| |
| // Build the stringpool for the section name table. |
| |
| Stringpool shstrtab; |
| shstrtab.add(".data", false, NULL); |
| shstrtab.add(".symtab", false, NULL); |
| shstrtab.add(".strtab", false, NULL); |
| shstrtab.add(".shstrtab", false, NULL); |
| shstrtab.set_string_offsets(); |
| |
| // Work out the size of the generated file, and the offsets of the |
| // various sections, and allocate a buffer. |
| |
| const int sym_size = elfcpp::Elf_sizes<size>::sym_size; |
| |
| size_t output_size = (elfcpp::Elf_sizes<size>::ehdr_size |
| + 5 * elfcpp::Elf_sizes<size>::shdr_size); |
| size_t data_offset = output_size; |
| output_size += aligned_filesize; |
| size_t symtab_offset = output_size; |
| output_size += 4 * sym_size; |
| size_t strtab_offset = output_size; |
| output_size += strtab.get_strtab_size(); |
| size_t shstrtab_offset = output_size; |
| output_size += shstrtab.get_strtab_size(); |
| |
| unsigned char* buffer = new unsigned char[output_size]; |
| |
| // Write out the data. |
| |
| unsigned char* pout = buffer; |
| |
| this->write_file_header<size, big_endian>(&pout); |
| |
| this->write_section_header<size, big_endian>("", &shstrtab, elfcpp::SHT_NULL, |
| 0, 0, 0, 0, 0, |
| 0, 0, &pout); |
| // Having the section be named ".data", having it be writable, and |
| // giving it an alignment of 1 is because the GNU linker does it |
| // that way, and existing linker script expect it. |
| this->write_section_header<size, big_endian>(".data", &shstrtab, |
| elfcpp::SHT_PROGBITS, |
| (elfcpp::SHF_ALLOC |
| | elfcpp::SHF_WRITE), |
| data_offset, |
| filesize, 0, 0, |
| 1, 0, &pout); |
| this->write_section_header<size, big_endian>(".symtab", &shstrtab, |
| elfcpp::SHT_SYMTAB, |
| 0, symtab_offset, 4 * sym_size, |
| 3, 1, align, sym_size, &pout); |
| this->write_section_header<size, big_endian>(".strtab", &shstrtab, |
| elfcpp::SHT_STRTAB, |
| 0, strtab_offset, |
| strtab.get_strtab_size(), |
| 0, 0, 1, 0, &pout); |
| this->write_section_header<size, big_endian>(".shstrtab", &shstrtab, |
| elfcpp::SHT_STRTAB, |
| 0, shstrtab_offset, |
| shstrtab.get_strtab_size(), |
| 0, 0, 1, 0, &pout); |
| |
| if (filesize > 0) |
| { |
| memcpy(pout, fileview, filesize); |
| pout += filesize; |
| memset(pout, 0, aligned_filesize - filesize); |
| pout += aligned_filesize - filesize; |
| } |
| |
| this->write_symbol<size, big_endian>("", &strtab, 0, 0, 0, &pout); |
| this->write_symbol<size, big_endian>(start_symbol_name, &strtab, 0, filesize, |
| 1, &pout); |
| this->write_symbol<size, big_endian>(end_symbol_name, &strtab, filesize, 0, |
| 1, &pout); |
| this->write_symbol<size, big_endian>(size_symbol_name, &strtab, filesize, 0, |
| elfcpp::SHN_ABS, &pout); |
| |
| strtab.write_to_buffer(pout, strtab.get_strtab_size()); |
| pout += strtab.get_strtab_size(); |
| |
| shstrtab.write_to_buffer(pout, shstrtab.get_strtab_size()); |
| pout += shstrtab.get_strtab_size(); |
| |
| gold_assert(static_cast<size_t>(pout - buffer) == output_size); |
| |
| this->data_ = buffer; |
| this->filesize_ = output_size; |
| |
| f.unlock(task); |
| |
| return true; |
| } |
| |
| // Write out the file header. |
| |
| template<int size, bool big_endian> |
| void |
| Binary_to_elf::write_file_header(unsigned char** ppout) |
| { |
| elfcpp::Ehdr_write<size, big_endian> oehdr(*ppout); |
| |
| unsigned char e_ident[elfcpp::EI_NIDENT]; |
| memset(e_ident, 0, elfcpp::EI_NIDENT); |
| e_ident[elfcpp::EI_MAG0] = elfcpp::ELFMAG0; |
| e_ident[elfcpp::EI_MAG1] = elfcpp::ELFMAG1; |
| e_ident[elfcpp::EI_MAG2] = elfcpp::ELFMAG2; |
| e_ident[elfcpp::EI_MAG3] = elfcpp::ELFMAG3; |
| if (size == 32) |
| e_ident[elfcpp::EI_CLASS] = elfcpp::ELFCLASS32; |
| else if (size == 64) |
| e_ident[elfcpp::EI_CLASS] = elfcpp::ELFCLASS64; |
| else |
| gold_unreachable(); |
| e_ident[elfcpp::EI_DATA] = (big_endian |
| ? elfcpp::ELFDATA2MSB |
| : elfcpp::ELFDATA2LSB); |
| e_ident[elfcpp::EI_VERSION] = elfcpp::EV_CURRENT; |
| oehdr.put_e_ident(e_ident); |
| |
| oehdr.put_e_type(elfcpp::ET_REL); |
| oehdr.put_e_machine(this->elf_machine_); |
| oehdr.put_e_version(elfcpp::EV_CURRENT); |
| oehdr.put_e_entry(0); |
| oehdr.put_e_phoff(0); |
| oehdr.put_e_shoff(elfcpp::Elf_sizes<size>::ehdr_size); |
| oehdr.put_e_flags(0); |
| oehdr.put_e_ehsize(elfcpp::Elf_sizes<size>::ehdr_size); |
| oehdr.put_e_phentsize(0); |
| oehdr.put_e_phnum(0); |
| oehdr.put_e_shentsize(elfcpp::Elf_sizes<size>::shdr_size); |
| oehdr.put_e_shnum(5); |
| oehdr.put_e_shstrndx(4); |
| |
| *ppout += elfcpp::Elf_sizes<size>::ehdr_size; |
| } |
| |
| // Write out a section header. |
| |
| template<int size, bool big_endian> |
| void |
| Binary_to_elf::write_section_header( |
| const char* name, |
| const Stringpool* shstrtab, |
| elfcpp::SHT type, |
| unsigned int flags, |
| section_size_type offset, |
| section_size_type section_size, |
| unsigned int link, |
| unsigned int info, |
| unsigned int addralign, |
| unsigned int entsize, |
| unsigned char** ppout) |
| { |
| elfcpp::Shdr_write<size, big_endian> oshdr(*ppout); |
| |
| oshdr.put_sh_name(*name == '\0' ? 0 : shstrtab->get_offset(name)); |
| oshdr.put_sh_type(type); |
| oshdr.put_sh_flags(flags); |
| oshdr.put_sh_addr(0); |
| oshdr.put_sh_offset(offset); |
| oshdr.put_sh_size(section_size); |
| oshdr.put_sh_link(link); |
| oshdr.put_sh_info(info); |
| oshdr.put_sh_addralign(addralign); |
| oshdr.put_sh_entsize(entsize); |
| |
| *ppout += elfcpp::Elf_sizes<size>::shdr_size; |
| } |
| |
| // Write out a symbol. |
| |
| template<int size, bool big_endian> |
| void |
| Binary_to_elf::write_symbol( |
| const std::string& name, |
| const Stringpool* strtab, |
| section_size_type value, |
| typename elfcpp::Elf_types<32>::Elf_WXword st_size, |
| unsigned int shndx, |
| unsigned char** ppout) |
| { |
| unsigned char* pout = *ppout; |
| |
| elfcpp::Sym_write<size, big_endian> osym(pout); |
| osym.put_st_name(name.empty() ? 0 : strtab->get_offset(name.c_str())); |
| osym.put_st_value(value); |
| osym.put_st_size(st_size); |
| osym.put_st_info(name.empty() ? elfcpp::STB_LOCAL : elfcpp::STB_GLOBAL, |
| elfcpp::STT_NOTYPE); |
| osym.put_st_other(elfcpp::STV_DEFAULT, 0); |
| osym.put_st_shndx(shndx); |
| |
| *ppout += elfcpp::Elf_sizes<size>::sym_size; |
| } |
| |
| } // End namespace gold. |