Google Git
Sign in
android / platform / art / 177b429 / . / compiler / elf_writer_quick.cc
blob: 09f2eaea204a7cedcd9e86c39e1f7e8b6b4a009e [file] [log] [blame]
/*
* Copyright (C) 2012 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_writer_quick.h"
#include "base/logging.h"
#include "base/unix_file/fd_file.h"
#include "buffered_output_stream.h"
#include "driver/compiler_driver.h"
#include "elf_utils.h"
#include "file_output_stream.h"
#include "globals.h"
#include "oat.h"
#include "oat_writer.h"
#include "utils.h"
namespace art {
bool ElfWriterQuick::Create(File* elf_file,
OatWriter* oat_writer,
const std::vector<const DexFile*>& dex_files,
const std::string& android_root,
bool is_host,
const CompilerDriver& driver) {
ElfWriterQuick elf_writer(driver, elf_file);
return elf_writer.Write(oat_writer, dex_files, android_root, is_host);
}
bool ElfWriterQuick::Write(OatWriter* oat_writer,
const std::vector<const DexFile*>& dex_files_unused,
const std::string& android_root_unused,
bool is_host_unused) {
const bool debug = false;
// +-------------------------+
// | Elf32_Ehdr |
// +-------------------------+
// | Elf32_Phdr PHDR |
// | Elf32_Phdr LOAD R | .dynsym .dynstr .hash .rodata
// | Elf32_Phdr LOAD R X | .text
// | Elf32_Phdr LOAD RW | .dynamic
// | Elf32_Phdr DYNAMIC | .dynamic
// +-------------------------+
// | .dynsym |
// | Elf32_Sym STN_UNDEF |
// | Elf32_Sym oatdata |
// | Elf32_Sym oatexec |
// | Elf32_Sym oatlastword |
// +-------------------------+
// | .dynstr |
// | \0 |
// | oatdata\0 |
// | oatexec\0 |
// | oatlastword\0 |
// | boot.oat\0 |
// +-------------------------+
// | .hash |
// | Elf32_Word nbucket = 1 |
// | Elf32_Word nchain = 3 |
// | Elf32_Word bucket[0] = 0|
// | Elf32_Word chain[0] = 1|
// | Elf32_Word chain[1] = 2|
// | Elf32_Word chain[2] = 3|
// +-------------------------+
// | .rodata |
// | oatdata..oatexec-4 |
// +-------------------------+
// | .text |
// | oatexec..oatlastword |
// +-------------------------+
// | .dynamic |
// | Elf32_Dyn DT_SONAME |
// | Elf32_Dyn DT_HASH |
// | Elf32_Dyn DT_SYMTAB |
// | Elf32_Dyn DT_SYMENT |
// | Elf32_Dyn DT_STRTAB |
// | Elf32_Dyn DT_STRSZ |
// | Elf32_Dyn DT_NULL |
// +-------------------------+
// | .shstrtab |
// | \0 |
// | .dynamic\0 |
// | .dynsym\0 |
// | .dynstr\0 |
// | .hash\0 |
// | .rodata\0 |
// | .text\0 |
// | .shstrtab\0 |
// | .debug_frame\0 |
// +-------------------------+
// | Elf32_Shdr NULL |
// | Elf32_Shdr .dynsym |
// | Elf32_Shdr .dynstr |
// | Elf32_Shdr .hash |
// | Elf32_Shdr .text |
// | Elf32_Shdr .rodata |
// | Elf32_Shdr .dynamic |
// | Elf32_Shdr .shstrtab |
// | Elf32_Shdr .debug_info | (Optional)
// | Elf32_Shdr .debug_abbrev| (Optional)
// | Elf32_Shdr .debug_frame | (Optional)
// +-------------------------+
// phase 1: computing offsets
uint32_t expected_offset = 0;
// Elf32_Ehdr
expected_offset += sizeof(Elf32_Ehdr);
// PHDR
uint32_t phdr_alignment = sizeof(Elf32_Word);
uint32_t phdr_offset = expected_offset;
const uint8_t PH_PHDR = 0;
const uint8_t PH_LOAD_R__ = 1;
const uint8_t PH_LOAD_R_X = 2;
const uint8_t PH_LOAD_RW_ = 3;
const uint8_t PH_DYNAMIC = 4;
const uint8_t PH_NUM = 5;
uint32_t phdr_size = sizeof(Elf32_Phdr) * PH_NUM;
expected_offset += phdr_size;
if (debug) {
LOG(INFO) << "phdr_offset=" << phdr_offset << std::hex << " " << phdr_offset;
LOG(INFO) << "phdr_size=" << phdr_size << std::hex << " " << phdr_size;
}
// .dynsym
uint32_t dynsym_alignment = sizeof(Elf32_Word);
uint32_t dynsym_offset = expected_offset = RoundUp(expected_offset, dynsym_alignment);
const uint8_t SYM_UNDEF = 0; // aka STN_UNDEF
const uint8_t SYM_OATDATA = 1;
const uint8_t SYM_OATEXEC = 2;
const uint8_t SYM_OATLASTWORD = 3;
const uint8_t SYM_NUM = 4;
uint32_t dynsym_size = sizeof(Elf32_Sym) * SYM_NUM;
expected_offset += dynsym_size;
if (debug) {
LOG(INFO) << "dynsym_offset=" << dynsym_offset << std::hex << " " << dynsym_offset;
LOG(INFO) << "dynsym_size=" << dynsym_size << std::hex << " " << dynsym_size;
}
// .dynstr
uint32_t dynstr_alignment = 1;
uint32_t dynstr_offset = expected_offset = RoundUp(expected_offset, dynstr_alignment);
std::string dynstr;
dynstr += '\0';
uint32_t dynstr_oatdata_offset = dynstr.size();
dynstr += "oatdata";
dynstr += '\0';
uint32_t dynstr_oatexec_offset = dynstr.size();
dynstr += "oatexec";
dynstr += '\0';
uint32_t dynstr_oatlastword_offset = dynstr.size();
dynstr += "oatlastword";
dynstr += '\0';
uint32_t dynstr_soname_offset = dynstr.size();
std::string file_name(elf_file_->GetPath());
size_t directory_separator_pos = file_name.rfind('/');
if (directory_separator_pos != std::string::npos) {
file_name = file_name.substr(directory_separator_pos + 1);
}
dynstr += file_name;
dynstr += '\0';
uint32_t dynstr_size = dynstr.size();
expected_offset += dynstr_size;
if (debug) {
LOG(INFO) << "dynstr_offset=" << dynstr_offset << std::hex << " " << dynstr_offset;
LOG(INFO) << "dynstr_size=" << dynstr_size << std::hex << " " << dynstr_size;
}
// .hash
uint32_t hash_alignment = sizeof(Elf32_Word); // Even for 64-bit
uint32_t hash_offset = expected_offset = RoundUp(expected_offset, hash_alignment);
const uint8_t HASH_NBUCKET = 0;
const uint8_t HASH_NCHAIN = 1;
const uint8_t HASH_BUCKET0 = 2;
const uint8_t HASH_NUM = HASH_BUCKET0 + 1 + SYM_NUM;
uint32_t hash_size = sizeof(Elf32_Word) * HASH_NUM;
expected_offset += hash_size;
if (debug) {
LOG(INFO) << "hash_offset=" << hash_offset << std::hex << " " << hash_offset;
LOG(INFO) << "hash_size=" << hash_size << std::hex << " " << hash_size;
}
// .rodata
uint32_t oat_data_alignment = kPageSize;
uint32_t oat_data_offset = expected_offset = RoundUp(expected_offset, oat_data_alignment);
const OatHeader& oat_header = oat_writer->GetOatHeader();
CHECK(oat_header.IsValid());
uint32_t oat_data_size = oat_header.GetExecutableOffset();
expected_offset += oat_data_size;
if (debug) {
LOG(INFO) << "oat_data_offset=" << oat_data_offset << std::hex << " " << oat_data_offset;
LOG(INFO) << "oat_data_size=" << oat_data_size << std::hex << " " << oat_data_size;
}
// .text
uint32_t oat_exec_alignment = kPageSize;
CHECK_ALIGNED(expected_offset, kPageSize);
uint32_t oat_exec_offset = expected_offset = RoundUp(expected_offset, oat_exec_alignment);
uint32_t oat_exec_size = oat_writer->GetSize() - oat_data_size;
expected_offset += oat_exec_size;
CHECK_EQ(oat_data_offset + oat_writer->GetSize(), expected_offset);
if (debug) {
LOG(INFO) << "oat_exec_offset=" << oat_exec_offset << std::hex << " " << oat_exec_offset;
LOG(INFO) << "oat_exec_size=" << oat_exec_size << std::hex << " " << oat_exec_size;
}
// .dynamic
// alignment would naturally be sizeof(Elf32_Word), but we want this in a new segment
uint32_t dynamic_alignment = kPageSize;
uint32_t dynamic_offset = expected_offset = RoundUp(expected_offset, dynamic_alignment);
const uint8_t DH_SONAME = 0;
const uint8_t DH_HASH = 1;
const uint8_t DH_SYMTAB = 2;
const uint8_t DH_SYMENT = 3;
const uint8_t DH_STRTAB = 4;
const uint8_t DH_STRSZ = 5;
const uint8_t DH_NULL = 6;
const uint8_t DH_NUM = 7;
uint32_t dynamic_size = sizeof(Elf32_Dyn) * DH_NUM;
expected_offset += dynamic_size;
if (debug) {
LOG(INFO) << "dynamic_offset=" << dynamic_offset << std::hex << " " << dynamic_offset;
LOG(INFO) << "dynamic_size=" << dynamic_size << std::hex << " " << dynamic_size;
}
// .shstrtab
uint32_t shstrtab_alignment = 1;
uint32_t shstrtab_offset = expected_offset = RoundUp(expected_offset, shstrtab_alignment);
std::string shstrtab;
shstrtab += '\0';
uint32_t shstrtab_dynamic_offset = shstrtab.size();
CHECK_EQ(1U, shstrtab_dynamic_offset);
shstrtab += ".dynamic";
shstrtab += '\0';
uint32_t shstrtab_dynsym_offset = shstrtab.size();
shstrtab += ".dynsym";
shstrtab += '\0';
uint32_t shstrtab_dynstr_offset = shstrtab.size();
shstrtab += ".dynstr";
shstrtab += '\0';
uint32_t shstrtab_hash_offset = shstrtab.size();
shstrtab += ".hash";
shstrtab += '\0';
uint32_t shstrtab_rodata_offset = shstrtab.size();
shstrtab += ".rodata";
shstrtab += '\0';
uint32_t shstrtab_text_offset = shstrtab.size();
shstrtab += ".text";
shstrtab += '\0';
uint32_t shstrtab_shstrtab_offset = shstrtab.size();
shstrtab += ".shstrtab";
shstrtab += '\0';
uint32_t shstrtab_debug_info_offset = shstrtab.size();
shstrtab += ".debug_info";
shstrtab += '\0';
uint32_t shstrtab_debug_abbrev_offset = shstrtab.size();
shstrtab += ".debug_abbrev";
shstrtab += '\0';
uint32_t shstrtab_debug_str_offset = shstrtab.size();
shstrtab += ".debug_str";
shstrtab += '\0';
uint32_t shstrtab_debug_frame_offset = shstrtab.size();
shstrtab += ".debug_frame";
shstrtab += '\0';
uint32_t shstrtab_size = shstrtab.size();
expected_offset += shstrtab_size;
if (debug) {
LOG(INFO) << "shstrtab_offset=" << shstrtab_offset << std::hex << " " << shstrtab_offset;
LOG(INFO) << "shstrtab_size=" << shstrtab_size << std::hex << " " << shstrtab_size;
}
// Create debug informatin, if we have it.
bool generateDebugInformation = compiler_driver_->GetCallFrameInformation() != nullptr;
std::vector<uint8_t> dbg_info;
std::vector<uint8_t> dbg_abbrev;
std::vector<uint8_t> dbg_str;
if (generateDebugInformation) {
FillInCFIInformation(oat_writer, &dbg_info, &dbg_abbrev, &dbg_str);
}
uint32_t shdbg_info_alignment = 1;
uint32_t shdbg_info_offset = expected_offset;
uint32_t shdbg_info_size = dbg_info.size();
expected_offset += shdbg_info_size;
if (debug) {
LOG(INFO) << "shdbg_info_offset=" << shdbg_info_offset << std::hex << " " << shdbg_info_offset;
LOG(INFO) << "shdbg_info_size=" << shdbg_info_size << std::hex << " " << shdbg_info_size;
}
uint32_t shdbg_abbrev_alignment = 1;
uint32_t shdbg_abbrev_offset = expected_offset;
uint32_t shdbg_abbrev_size = dbg_abbrev.size();
expected_offset += shdbg_abbrev_size;
if (debug) {
LOG(INFO) << "shdbg_abbrev_offset=" << shdbg_abbrev_offset << std::hex << " " << shdbg_abbrev_offset;
LOG(INFO) << "shdbg_abbrev_size=" << shdbg_abbrev_size << std::hex << " " << shdbg_abbrev_size;
}
uint32_t shdbg_frm_alignment = 4;
uint32_t shdbg_frm_offset = expected_offset = RoundUp(expected_offset, shdbg_frm_alignment);
uint32_t shdbg_frm_size =
generateDebugInformation ? compiler_driver_->GetCallFrameInformation()->size() : 0;
expected_offset += shdbg_frm_size;
if (debug) {
LOG(INFO) << "shdbg_frm_offset=" << shdbg_frm_offset << std::hex << " " << shdbg_frm_offset;
LOG(INFO) << "shdbg_frm_size=" << shdbg_frm_size << std::hex << " " << shdbg_frm_size;
}
uint32_t shdbg_str_alignment = 1;
uint32_t shdbg_str_offset = expected_offset;
uint32_t shdbg_str_size = dbg_str.size();
expected_offset += shdbg_str_size;
if (debug) {
LOG(INFO) << "shdbg_str_offset=" << shdbg_str_offset << std::hex << " " << shdbg_str_offset;
LOG(INFO) << "shdbg_str_size=" << shdbg_str_size << std::hex << " " << shdbg_str_size;
}
// section headers (after all sections)
uint32_t shdr_alignment = sizeof(Elf32_Word);
uint32_t shdr_offset = expected_offset = RoundUp(expected_offset, shdr_alignment);
const uint8_t SH_NULL = 0;
const uint8_t SH_DYNSYM = 1;
const uint8_t SH_DYNSTR = 2;
const uint8_t SH_HASH = 3;
const uint8_t SH_RODATA = 4;
const uint8_t SH_TEXT = 5;
const uint8_t SH_DYNAMIC = 6;
const uint8_t SH_SHSTRTAB = 7;
const uint8_t SH_DBG_INFO = 8;
const uint8_t SH_DBG_ABRV = 9;
const uint8_t SH_DBG_FRM = 10;
const uint8_t SH_DBG_STR = 11;
const uint8_t SH_NUM = generateDebugInformation ? 12 : 8;
uint32_t shdr_size = sizeof(Elf32_Shdr) * SH_NUM;
expected_offset += shdr_size;
if (debug) {
LOG(INFO) << "shdr_offset=" << shdr_offset << std::hex << " " << shdr_offset;
LOG(INFO) << "shdr_size=" << shdr_size << std::hex << " " << shdr_size;
}
// phase 2: initializing data
// Elf32_Ehdr
Elf32_Ehdr elf_header;
memset(&elf_header, 0, sizeof(elf_header));
elf_header.e_ident[EI_MAG0] = ELFMAG0;
elf_header.e_ident[EI_MAG1] = ELFMAG1;
elf_header.e_ident[EI_MAG2] = ELFMAG2;
elf_header.e_ident[EI_MAG3] = ELFMAG3;
elf_header.e_ident[EI_CLASS] = ELFCLASS32;
elf_header.e_ident[EI_DATA] = ELFDATA2LSB;
elf_header.e_ident[EI_VERSION] = EV_CURRENT;
elf_header.e_ident[EI_OSABI] = ELFOSABI_LINUX;
elf_header.e_ident[EI_ABIVERSION] = 0;
elf_header.e_type = ET_DYN;
switch (compiler_driver_->GetInstructionSet()) {
case kArm:
// Fall through.
case kThumb2: {
elf_header.e_machine = EM_ARM;
elf_header.e_flags = EF_ARM_EABI_VER5;
break;
}
case kArm64: {
elf_header.e_machine = EM_AARCH64;
elf_header.e_flags = 0;
break;
}
case kX86: {
elf_header.e_machine = EM_386;
elf_header.e_flags = 0;
break;
}
case kX86_64: {
elf_header.e_machine = EM_X86_64;
elf_header.e_flags = 0;
break;
}
case kMips: {
elf_header.e_machine = EM_MIPS;
elf_header.e_flags = (EF_MIPS_NOREORDER |
EF_MIPS_PIC |
EF_MIPS_CPIC |
EF_MIPS_ABI_O32 |
EF_MIPS_ARCH_32R2);
break;
}
default: {
LOG(FATAL) << "Unknown instruction set: " << compiler_driver_->GetInstructionSet();
break;
}
}
elf_header.e_version = 1;
elf_header.e_entry = 0;
elf_header.e_phoff = phdr_offset;
elf_header.e_shoff = shdr_offset;
elf_header.e_ehsize = sizeof(Elf32_Ehdr);
elf_header.e_phentsize = sizeof(Elf32_Phdr);
elf_header.e_phnum = PH_NUM;
elf_header.e_shentsize = sizeof(Elf32_Shdr);
elf_header.e_shnum = SH_NUM;
elf_header.e_shstrndx = SH_SHSTRTAB;
// PHDR
Elf32_Phdr program_headers[PH_NUM];
memset(&program_headers, 0, sizeof(program_headers));
program_headers[PH_PHDR].p_type = PT_PHDR;
program_headers[PH_PHDR].p_offset = phdr_offset;
program_headers[PH_PHDR].p_vaddr = phdr_offset;
program_headers[PH_PHDR].p_paddr = phdr_offset;
program_headers[PH_PHDR].p_filesz = sizeof(program_headers);
program_headers[PH_PHDR].p_memsz = sizeof(program_headers);
program_headers[PH_PHDR].p_flags = PF_R;
program_headers[PH_PHDR].p_align = phdr_alignment;
program_headers[PH_LOAD_R__].p_type = PT_LOAD;
program_headers[PH_LOAD_R__].p_offset = 0;
program_headers[PH_LOAD_R__].p_vaddr = 0;
program_headers[PH_LOAD_R__].p_paddr = 0;
program_headers[PH_LOAD_R__].p_filesz = oat_data_offset + oat_data_size;
program_headers[PH_LOAD_R__].p_memsz = oat_data_offset + oat_data_size;
program_headers[PH_LOAD_R__].p_flags = PF_R;
program_headers[PH_LOAD_R__].p_align = oat_data_alignment;
program_headers[PH_LOAD_R_X].p_type = PT_LOAD;
program_headers[PH_LOAD_R_X].p_offset = oat_exec_offset;
program_headers[PH_LOAD_R_X].p_vaddr = oat_exec_offset;
program_headers[PH_LOAD_R_X].p_paddr = oat_exec_offset;
program_headers[PH_LOAD_R_X].p_filesz = oat_exec_size;
program_headers[PH_LOAD_R_X].p_memsz = oat_exec_size;
program_headers[PH_LOAD_R_X].p_flags = PF_R | PF_X;
program_headers[PH_LOAD_R_X].p_align = oat_exec_alignment;
// TODO: PF_W for DYNAMIC is considered processor specific, do we need it?
program_headers[PH_LOAD_RW_].p_type = PT_LOAD;
program_headers[PH_LOAD_RW_].p_offset = dynamic_offset;
program_headers[PH_LOAD_RW_].p_vaddr = dynamic_offset;
program_headers[PH_LOAD_RW_].p_paddr = dynamic_offset;
program_headers[PH_LOAD_RW_].p_filesz = dynamic_size;
program_headers[PH_LOAD_RW_].p_memsz = dynamic_size;
program_headers[PH_LOAD_RW_].p_flags = PF_R | PF_W;
program_headers[PH_LOAD_RW_].p_align = dynamic_alignment;
// TODO: PF_W for DYNAMIC is considered processor specific, do we need it?
program_headers[PH_DYNAMIC].p_type = PT_DYNAMIC;
program_headers[PH_DYNAMIC].p_offset = dynamic_offset;
program_headers[PH_DYNAMIC].p_vaddr = dynamic_offset;
program_headers[PH_DYNAMIC].p_paddr = dynamic_offset;
program_headers[PH_DYNAMIC].p_filesz = dynamic_size;
program_headers[PH_DYNAMIC].p_memsz = dynamic_size;
program_headers[PH_DYNAMIC].p_flags = PF_R | PF_W;
program_headers[PH_DYNAMIC].p_align = dynamic_alignment;
// .dynsym
Elf32_Sym dynsym[SYM_NUM];
memset(&dynsym, 0, sizeof(dynsym));
dynsym[SYM_UNDEF].st_name = 0;
dynsym[SYM_UNDEF].st_value = 0;
dynsym[SYM_UNDEF].st_size = 0;
dynsym[SYM_UNDEF].st_info = 0;
dynsym[SYM_UNDEF].st_other = 0;
dynsym[SYM_UNDEF].st_shndx = 0;
dynsym[SYM_OATDATA].st_name = dynstr_oatdata_offset;
dynsym[SYM_OATDATA].st_value = oat_data_offset;
dynsym[SYM_OATDATA].st_size = oat_data_size;
SetBindingAndType(&dynsym[SYM_OATDATA], STB_GLOBAL, STT_OBJECT);
dynsym[SYM_OATDATA].st_other = STV_DEFAULT;
dynsym[SYM_OATDATA].st_shndx = SH_RODATA;
dynsym[SYM_OATEXEC].st_name = dynstr_oatexec_offset;
dynsym[SYM_OATEXEC].st_value = oat_exec_offset;
dynsym[SYM_OATEXEC].st_size = oat_exec_size;
SetBindingAndType(&dynsym[SYM_OATEXEC], STB_GLOBAL, STT_OBJECT);
dynsym[SYM_OATEXEC].st_other = STV_DEFAULT;
dynsym[SYM_OATEXEC].st_shndx = SH_TEXT;
dynsym[SYM_OATLASTWORD].st_name = dynstr_oatlastword_offset;
dynsym[SYM_OATLASTWORD].st_value = oat_exec_offset + oat_exec_size - 4;
dynsym[SYM_OATLASTWORD].st_size = 4;
SetBindingAndType(&dynsym[SYM_OATLASTWORD], STB_GLOBAL, STT_OBJECT);
dynsym[SYM_OATLASTWORD].st_other = STV_DEFAULT;
dynsym[SYM_OATLASTWORD].st_shndx = SH_TEXT;
// .dynstr initialized above as dynstr
// .hash
Elf32_Word hash[HASH_NUM]; // Note this is Elf32_Word even on 64-bit
hash[HASH_NBUCKET] = 1;
hash[HASH_NCHAIN] = SYM_NUM;
hash[HASH_BUCKET0] = SYM_OATDATA;
hash[HASH_BUCKET0 + 1 + SYM_UNDEF] = SYM_UNDEF;
hash[HASH_BUCKET0 + 1 + SYM_OATDATA] = SYM_OATEXEC;
hash[HASH_BUCKET0 + 1 + SYM_OATEXEC] = SYM_OATLASTWORD;
hash[HASH_BUCKET0 + 1 + SYM_OATLASTWORD] = SYM_UNDEF;
// .rodata and .text content come from oat_contents
// .dynamic
Elf32_Dyn dynamic_headers[DH_NUM];
memset(&dynamic_headers, 0, sizeof(dynamic_headers));
dynamic_headers[DH_SONAME].d_tag = DT_SONAME;
dynamic_headers[DH_SONAME].d_un.d_val = dynstr_soname_offset;
dynamic_headers[DH_HASH].d_tag = DT_HASH;
dynamic_headers[DH_HASH].d_un.d_ptr = hash_offset;
dynamic_headers[DH_SYMTAB].d_tag = DT_SYMTAB;
dynamic_headers[DH_SYMTAB].d_un.d_ptr = dynsym_offset;
dynamic_headers[DH_SYMENT].d_tag = DT_SYMENT;
dynamic_headers[DH_SYMENT].d_un.d_val = sizeof(Elf32_Sym);
dynamic_headers[DH_STRTAB].d_tag = DT_STRTAB;
dynamic_headers[DH_STRTAB].d_un.d_ptr = dynstr_offset;
dynamic_headers[DH_STRSZ].d_tag = DT_STRSZ;
dynamic_headers[DH_STRSZ].d_un.d_val = dynstr_size;
dynamic_headers[DH_NULL].d_tag = DT_NULL;
dynamic_headers[DH_NULL].d_un.d_val = 0;
// .shstrtab initialized above as shstrtab
// section headers (after all sections)
Elf32_Shdr section_headers[SH_NUM];
memset(&section_headers, 0, sizeof(section_headers));
section_headers[SH_NULL].sh_name = 0;
section_headers[SH_NULL].sh_type = SHT_NULL;
section_headers[SH_NULL].sh_flags = 0;
section_headers[SH_NULL].sh_addr = 0;
section_headers[SH_NULL].sh_offset = 0;
section_headers[SH_NULL].sh_size = 0;
section_headers[SH_NULL].sh_link = 0;
section_headers[SH_NULL].sh_info = 0;
section_headers[SH_NULL].sh_addralign = 0;
section_headers[SH_NULL].sh_entsize = 0;
section_headers[SH_DYNSYM].sh_name = shstrtab_dynsym_offset;
section_headers[SH_DYNSYM].sh_type = SHT_DYNSYM;
section_headers[SH_DYNSYM].sh_flags = SHF_ALLOC;
section_headers[SH_DYNSYM].sh_addr = dynsym_offset;
section_headers[SH_DYNSYM].sh_offset = dynsym_offset;
section_headers[SH_DYNSYM].sh_size = dynsym_size;
section_headers[SH_DYNSYM].sh_link = SH_DYNSTR;
section_headers[SH_DYNSYM].sh_info = 1; // 1 because we have not STB_LOCAL symbols
section_headers[SH_DYNSYM].sh_addralign = dynsym_alignment;
section_headers[SH_DYNSYM].sh_entsize = sizeof(Elf32_Sym);
section_headers[SH_DYNSTR].sh_name = shstrtab_dynstr_offset;
section_headers[SH_DYNSTR].sh_type = SHT_STRTAB;
section_headers[SH_DYNSTR].sh_flags = SHF_ALLOC;
section_headers[SH_DYNSTR].sh_addr = dynstr_offset;
section_headers[SH_DYNSTR].sh_offset = dynstr_offset;
section_headers[SH_DYNSTR].sh_size = dynstr_size;
section_headers[SH_DYNSTR].sh_link = 0;
section_headers[SH_DYNSTR].sh_info = 0;
section_headers[SH_DYNSTR].sh_addralign = dynstr_alignment;
section_headers[SH_DYNSTR].sh_entsize = 0;
section_headers[SH_HASH].sh_name = shstrtab_hash_offset;
section_headers[SH_HASH].sh_type = SHT_HASH;
section_headers[SH_HASH].sh_flags = SHF_ALLOC;
section_headers[SH_HASH].sh_addr = hash_offset;
section_headers[SH_HASH].sh_offset = hash_offset;
section_headers[SH_HASH].sh_size = hash_size;
section_headers[SH_HASH].sh_link = SH_DYNSYM;
section_headers[SH_HASH].sh_info = 0;
section_headers[SH_HASH].sh_addralign = hash_alignment;
section_headers[SH_HASH].sh_entsize = sizeof(Elf32_Word); // This is Elf32_Word even on 64-bit
section_headers[SH_RODATA].sh_name = shstrtab_rodata_offset;
section_headers[SH_RODATA].sh_type = SHT_PROGBITS;
section_headers[SH_RODATA].sh_flags = SHF_ALLOC;
section_headers[SH_RODATA].sh_addr = oat_data_offset;
section_headers[SH_RODATA].sh_offset = oat_data_offset;
section_headers[SH_RODATA].sh_size = oat_data_size;
section_headers[SH_RODATA].sh_link = 0;
section_headers[SH_RODATA].sh_info = 0;
section_headers[SH_RODATA].sh_addralign = oat_data_alignment;
section_headers[SH_RODATA].sh_entsize = 0;
section_headers[SH_TEXT].sh_name = shstrtab_text_offset;
section_headers[SH_TEXT].sh_type = SHT_PROGBITS;
section_headers[SH_TEXT].sh_flags = SHF_ALLOC | SHF_EXECINSTR;
section_headers[SH_TEXT].sh_addr = oat_exec_offset;
section_headers[SH_TEXT].sh_offset = oat_exec_offset;
section_headers[SH_TEXT].sh_size = oat_exec_size;
section_headers[SH_TEXT].sh_link = 0;
section_headers[SH_TEXT].sh_info = 0;
section_headers[SH_TEXT].sh_addralign = oat_exec_alignment;
section_headers[SH_TEXT].sh_entsize = 0;
// TODO: SHF_WRITE for .dynamic is considered processor specific, do we need it?
section_headers[SH_DYNAMIC].sh_name = shstrtab_dynamic_offset;
section_headers[SH_DYNAMIC].sh_type = SHT_DYNAMIC;
section_headers[SH_DYNAMIC].sh_flags = SHF_WRITE | SHF_ALLOC;
section_headers[SH_DYNAMIC].sh_addr = dynamic_offset;
section_headers[SH_DYNAMIC].sh_offset = dynamic_offset;
section_headers[SH_DYNAMIC].sh_size = dynamic_size;
section_headers[SH_DYNAMIC].sh_link = SH_DYNSTR;
section_headers[SH_DYNAMIC].sh_info = 0;
section_headers[SH_DYNAMIC].sh_addralign = dynamic_alignment;
section_headers[SH_DYNAMIC].sh_entsize = sizeof(Elf32_Dyn);
section_headers[SH_SHSTRTAB].sh_name = shstrtab_shstrtab_offset;
section_headers[SH_SHSTRTAB].sh_type = SHT_STRTAB;
section_headers[SH_SHSTRTAB].sh_flags = 0;
section_headers[SH_SHSTRTAB].sh_addr = shstrtab_offset;
section_headers[SH_SHSTRTAB].sh_offset = shstrtab_offset;
section_headers[SH_SHSTRTAB].sh_size = shstrtab_size;
section_headers[SH_SHSTRTAB].sh_link = 0;
section_headers[SH_SHSTRTAB].sh_info = 0;
section_headers[SH_SHSTRTAB].sh_addralign = shstrtab_alignment;
section_headers[SH_SHSTRTAB].sh_entsize = 0;
if (generateDebugInformation) {
section_headers[SH_DBG_INFO].sh_name = shstrtab_debug_info_offset;
section_headers[SH_DBG_INFO].sh_type = SHT_PROGBITS;
section_headers[SH_DBG_INFO].sh_flags = 0;
section_headers[SH_DBG_INFO].sh_addr = 0;
section_headers[SH_DBG_INFO].sh_offset = shdbg_info_offset;
section_headers[SH_DBG_INFO].sh_size = shdbg_info_size;
section_headers[SH_DBG_INFO].sh_link = 0;
section_headers[SH_DBG_INFO].sh_info = 0;
section_headers[SH_DBG_INFO].sh_addralign = shdbg_info_alignment;
section_headers[SH_DBG_INFO].sh_entsize = 0;
section_headers[SH_DBG_ABRV].sh_name = shstrtab_debug_abbrev_offset;
section_headers[SH_DBG_ABRV].sh_type = SHT_PROGBITS;
section_headers[SH_DBG_ABRV].sh_flags = 0;
section_headers[SH_DBG_ABRV].sh_addr = 0;
section_headers[SH_DBG_ABRV].sh_offset = shdbg_abbrev_offset;
section_headers[SH_DBG_ABRV].sh_size = shdbg_abbrev_size;
section_headers[SH_DBG_ABRV].sh_link = 0;
section_headers[SH_DBG_ABRV].sh_info = 0;
section_headers[SH_DBG_ABRV].sh_addralign = shdbg_abbrev_alignment;
section_headers[SH_DBG_ABRV].sh_entsize = 0;
section_headers[SH_DBG_FRM].sh_name = shstrtab_debug_frame_offset;
section_headers[SH_DBG_FRM].sh_type = SHT_PROGBITS;
section_headers[SH_DBG_FRM].sh_flags = 0;
section_headers[SH_DBG_FRM].sh_addr = 0;
section_headers[SH_DBG_FRM].sh_offset = shdbg_frm_offset;
section_headers[SH_DBG_FRM].sh_size = shdbg_frm_size;
section_headers[SH_DBG_FRM].sh_link = 0;
section_headers[SH_DBG_FRM].sh_info = 0;
section_headers[SH_DBG_FRM].sh_addralign = shdbg_frm_alignment;
section_headers[SH_DBG_FRM].sh_entsize = 0;
section_headers[SH_DBG_STR].sh_name = shstrtab_debug_str_offset;
section_headers[SH_DBG_STR].sh_type = SHT_PROGBITS;
section_headers[SH_DBG_STR].sh_flags = 0;
section_headers[SH_DBG_STR].sh_addr = 0;
section_headers[SH_DBG_STR].sh_offset = shdbg_str_offset;
section_headers[SH_DBG_STR].sh_size = shdbg_str_size;
section_headers[SH_DBG_STR].sh_link = 0;
section_headers[SH_DBG_STR].sh_info = 0;
section_headers[SH_DBG_STR].sh_addralign = shdbg_str_alignment;
section_headers[SH_DBG_STR].sh_entsize = 0;
}
// phase 3: writing file
// Elf32_Ehdr
if (!elf_file_->WriteFully(&elf_header, sizeof(elf_header))) {
PLOG(ERROR) << "Failed to write ELF header for " << elf_file_->GetPath();
return false;
}
// PHDR
if (static_cast<off_t>(phdr_offset) != lseek(elf_file_->Fd(), 0, SEEK_CUR)) {
PLOG(ERROR) << "Failed to be at expected ELF program header offset phdr_offset "
<< " for " << elf_file_->GetPath();
return false;
}
if (!elf_file_->WriteFully(program_headers, sizeof(program_headers))) {
PLOG(ERROR) << "Failed to write ELF program headers for " << elf_file_->GetPath();
return false;
}
// .dynsym
DCHECK_LE(phdr_offset + phdr_size, dynsym_offset);
if (static_cast<off_t>(dynsym_offset) != lseek(elf_file_->Fd(), dynsym_offset, SEEK_SET)) {
PLOG(ERROR) << "Failed to seek to .dynsym offset location " << dynsym_offset
<< " for " << elf_file_->GetPath();
return false;
}
if (!elf_file_->WriteFully(dynsym, sizeof(dynsym))) {
PLOG(ERROR) << "Failed to write .dynsym for " << elf_file_->GetPath();
return false;
}
// .dynstr
DCHECK_LE(dynsym_offset + dynsym_size, dynstr_offset);
if (static_cast<off_t>(dynstr_offset) != lseek(elf_file_->Fd(), dynstr_offset, SEEK_SET)) {
PLOG(ERROR) << "Failed to seek to .dynstr offset " << dynstr_offset
<< " for " << elf_file_->GetPath();
return false;
}
if (!elf_file_->WriteFully(&dynstr[0], dynstr_size)) {
PLOG(ERROR) << "Failed to write .dynsym for " << elf_file_->GetPath();
return false;
}
// .hash
DCHECK_LE(dynstr_offset + dynstr_size, hash_offset);
if (static_cast<off_t>(hash_offset) != lseek(elf_file_->Fd(), hash_offset, SEEK_SET)) {
PLOG(ERROR) << "Failed to seek to .hash offset " << hash_offset
<< " for " << elf_file_->GetPath();
return false;
}
if (!elf_file_->WriteFully(hash, sizeof(hash))) {
PLOG(ERROR) << "Failed to write .dynsym for " << elf_file_->GetPath();
return false;
}
// .rodata .text
DCHECK_LE(hash_offset + hash_size, oat_data_offset);
if (static_cast<off_t>(oat_data_offset) != lseek(elf_file_->Fd(), oat_data_offset, SEEK_SET)) {
PLOG(ERROR) << "Failed to seek to .rodata offset " << oat_data_offset
<< " for " << elf_file_->GetPath();
return false;
}
std::unique_ptr<BufferedOutputStream> output_stream(new BufferedOutputStream(new FileOutputStream(elf_file_)));
if (!oat_writer->Write(output_stream.get())) {
PLOG(ERROR) << "Failed to write .rodata and .text for " << elf_file_->GetPath();
return false;
}
// .dynamic
DCHECK_LE(oat_data_offset + oat_writer->GetSize(), dynamic_offset);
if (static_cast<off_t>(dynamic_offset) != lseek(elf_file_->Fd(), dynamic_offset, SEEK_SET)) {
PLOG(ERROR) << "Failed to seek to .dynamic offset " << dynamic_offset
<< " for " << elf_file_->GetPath();
return false;
}
if (!elf_file_->WriteFully(&dynamic_headers[0], dynamic_size)) {
PLOG(ERROR) << "Failed to write .dynamic for " << elf_file_->GetPath();
return false;
}
// .shstrtab
DCHECK_LE(dynamic_offset + dynamic_size, shstrtab_offset);
if (static_cast<off_t>(shstrtab_offset) != lseek(elf_file_->Fd(), shstrtab_offset, SEEK_SET)) {
PLOG(ERROR) << "Failed to seek to .shstrtab offset " << shstrtab_offset
<< " for " << elf_file_->GetPath();
return false;
}
if (!elf_file_->WriteFully(&shstrtab[0], shstrtab_size)) {
PLOG(ERROR) << "Failed to write .shstrtab for " << elf_file_->GetPath();
return false;
}
if (generateDebugInformation) {
// .debug_info
DCHECK_LE(shstrtab_offset + shstrtab_size, shdbg_info_offset);
if (static_cast<off_t>(shdbg_info_offset) != lseek(elf_file_->Fd(), shdbg_info_offset, SEEK_SET)) {
PLOG(ERROR) << "Failed to seek to .shdbg_info offset " << shdbg_info_offset
<< " for " << elf_file_->GetPath();
return false;
}
if (!elf_file_->WriteFully(&dbg_info[0], shdbg_info_size)) {
PLOG(ERROR) << "Failed to write .debug_info for " << elf_file_->GetPath();
return false;
}
// .debug_abbrev
DCHECK_LE(shdbg_info_offset + shdbg_info_size, shdbg_abbrev_offset);
if (static_cast<off_t>(shdbg_abbrev_offset) != lseek(elf_file_->Fd(), shdbg_abbrev_offset, SEEK_SET)) {
PLOG(ERROR) << "Failed to seek to .shdbg_abbrev offset " << shdbg_abbrev_offset
<< " for " << elf_file_->GetPath();
return false;
}
if (!elf_file_->WriteFully(&dbg_abbrev[0], shdbg_abbrev_size)) {
PLOG(ERROR) << "Failed to write .debug_abbrev for " << elf_file_->GetPath();
return false;
}
// .debug_frame
DCHECK_LE(shdbg_abbrev_offset + shdbg_abbrev_size, shdbg_frm_offset);
if (static_cast<off_t>(shdbg_frm_offset) != lseek(elf_file_->Fd(), shdbg_frm_offset, SEEK_SET)) {
PLOG(ERROR) << "Failed to seek to .shdbg_frm offset " << shdbg_frm_offset
<< " for " << elf_file_->GetPath();
return false;
}
if (!elf_file_->WriteFully(&((*compiler_driver_->GetCallFrameInformation())[0]), shdbg_frm_size)) {
PLOG(ERROR) << "Failed to write .debug_frame for " << elf_file_->GetPath();
return false;
}
// .debug_str
DCHECK_LE(shdbg_frm_offset + shdbg_frm_size, shdbg_str_offset);
if (static_cast<off_t>(shdbg_str_offset) != lseek(elf_file_->Fd(), shdbg_str_offset, SEEK_SET)) {
PLOG(ERROR) << "Failed to seek to .shdbg_str offset " << shdbg_str_offset
<< " for " << elf_file_->GetPath();
return false;
}
if (!elf_file_->WriteFully(&dbg_str[0], shdbg_str_size)) {
PLOG(ERROR) << "Failed to write .debug_frame for " << elf_file_->GetPath();
return false;
}
}
// section headers (after all sections)
if (generateDebugInformation) {
DCHECK_LE(shdbg_str_offset + shdbg_str_size, shdr_offset);
} else {
DCHECK_LE(shstrtab_offset + shstrtab_size, shdr_offset);
}
if (static_cast<off_t>(shdr_offset) != lseek(elf_file_->Fd(), shdr_offset, SEEK_SET)) {
PLOG(ERROR) << "Failed to seek to ELF section headers offset " << shdr_offset
<< " for " << elf_file_->GetPath();
return false;
}
if (!elf_file_->WriteFully(section_headers, sizeof(section_headers))) {
PLOG(ERROR) << "Failed to write ELF section headers for " << elf_file_->GetPath();
return false;
}
VLOG(compiler) << "ELF file written successfully: " << elf_file_->GetPath();
return true;
} // NOLINT(readability/fn_size)
static void UpdateWord(std::vector<uint8_t>*buf, int offset, int data) {
(*buf)[offset+0] = data;
(*buf)[offset+1] = data >> 8;
(*buf)[offset+2] = data >> 16;
(*buf)[offset+3] = data >> 24;
}
static void PushWord(std::vector<uint8_t>*buf, int data) {
buf->push_back(data & 0xff);
buf->push_back((data >> 8) & 0xff);
buf->push_back((data >> 16) & 0xff);
buf->push_back((data >> 24) & 0xff);
}
static void PushHalf(std::vector<uint8_t>*buf, int data) {
buf->push_back(data & 0xff);
buf->push_back((data >> 8) & 0xff);
}
// DWARF constants needed to generate CFI information.
enum {
// Tag encodings.
DW_TAG_compile_unit = 0x11,
DW_TAG_subprogram = 0X2e,
// Attribute encodings.
DW_AT_name = 0x03,
DW_AT_low_pc = 0x11,
DW_AT_high_pc = 0x12,
DW_AT_language = 0x13,
// Constant encoding.
DW_CHILDREN_no = 0x00,
DW_CHILDREN_yes = 0x01,
// Attribute form encodings.
DW_FORM_addr = 0x01,
DW_FORM_data1 = 0x0b,
DW_FORM_strp = 0x0e,
// Language encoding.
DW_LANG_Java = 0x000b
};
void ElfWriterQuick::FillInCFIInformation(OatWriter* oat_writer,
std::vector<uint8_t>* dbg_info,
std::vector<uint8_t>* dbg_abbrev,
std::vector<uint8_t>* dbg_str) {
// Create the debug_abbrev section with boilerplate information.
// We only care about low_pc and high_pc right now for the compilation
// unit and methods.
// Tag 1: Compilation unit: DW_TAG_compile_unit.
dbg_abbrev->push_back(1);
dbg_abbrev->push_back(DW_TAG_compile_unit);
// There are children (the methods).
dbg_abbrev->push_back(DW_CHILDREN_yes);
// DW_LANG_Java DW_FORM_data1.
dbg_abbrev->push_back(DW_AT_language);
dbg_abbrev->push_back(DW_FORM_data1);
// DW_AT_low_pc DW_FORM_addr.
dbg_abbrev->push_back(DW_AT_low_pc);
dbg_abbrev->push_back(DW_FORM_addr);
// DW_AT_high_pc DW_FORM_addr.
dbg_abbrev->push_back(DW_AT_high_pc);
dbg_abbrev->push_back(DW_FORM_addr);
// End of DW_TAG_compile_unit.
PushHalf(dbg_abbrev, 0);
// Tag 2: Compilation unit: DW_TAG_subprogram.
dbg_abbrev->push_back(2);
dbg_abbrev->push_back(DW_TAG_subprogram);
// There are no children.
dbg_abbrev->push_back(DW_CHILDREN_no);
// Name of the method.
dbg_abbrev->push_back(DW_AT_name);
dbg_abbrev->push_back(DW_FORM_strp);
// DW_AT_low_pc DW_FORM_addr.
dbg_abbrev->push_back(DW_AT_low_pc);
dbg_abbrev->push_back(DW_FORM_addr);
// DW_AT_high_pc DW_FORM_addr.
dbg_abbrev->push_back(DW_AT_high_pc);
dbg_abbrev->push_back(DW_FORM_addr);
// End of DW_TAG_subprogram.
PushHalf(dbg_abbrev, 0);
// Start the debug_info section with the header information
// 'unit_length' will be filled in later.
PushWord(dbg_info, 0);
// 'version' - 3.
PushHalf(dbg_info, 3);
// Offset into .debug_abbrev section (always 0).
PushWord(dbg_info, 0);
// Address size: 4.
dbg_info->push_back(4);
// Start the description for the compilation unit.
// This uses tag 1.
dbg_info->push_back(1);
// The language is Java.
dbg_info->push_back(DW_LANG_Java);
// Leave space for low_pc and high_pc.
int low_pc_offset = dbg_info->size();
PushWord(dbg_info, 0);
PushWord(dbg_info, 0);
// Walk through the information in the method table, and enter into dbg_info.
const std::vector<OatWriter::DebugInfo>& dbg = oat_writer->GetCFIMethodInfo();
uint32_t low_pc = 0xFFFFFFFFU;
uint32_t high_pc = 0;
for (uint32_t i = 0; i < dbg.size(); i++) {
const OatWriter::DebugInfo& info = dbg[i];
if (info.low_pc_ < low_pc) {
low_pc = info.low_pc_;
}
if (info.high_pc_ > high_pc) {
high_pc = info.high_pc_;
}
// Start a new TAG: subroutine (2).
dbg_info->push_back(2);
// Enter the name into the string table (and NUL terminate).
uint32_t str_offset = dbg_str->size();
dbg_str->insert(dbg_str->end(), info.method_name_.begin(), info.method_name_.end());
dbg_str->push_back('\0');
// Enter name, low_pc, high_pc.
PushWord(dbg_info, str_offset);
PushWord(dbg_info, info.low_pc_);
PushWord(dbg_info, info.high_pc_);
}
// One byte terminator
dbg_info->push_back(0);
// We have now walked all the methods. Fill in lengths and low/high PCs.
UpdateWord(dbg_info, 0, dbg_info->size() - 4);
UpdateWord(dbg_info, low_pc_offset, low_pc);
UpdateWord(dbg_info, low_pc_offset + 4, high_pc);
}
} // namespace art