Refactor ElfWriter and introduce ElfWriterQuick
Change-Id: I3eaa1fa1085bb4d28fe342a7420272720e48274b
diff --git a/src/elf_fixup.cc b/src/elf_fixup.cc
new file mode 100644
index 0000000..127bc85
--- /dev/null
+++ b/src/elf_fixup.cc
@@ -0,0 +1,279 @@
+/*
+ * 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_fixup.h"
+
+#include "base/logging.h"
+#include "base/stringprintf.h"
+#include "elf_file.h"
+#include "elf_writer.h"
+#include "UniquePtr.h"
+
+namespace art {
+
+static const bool DEBUG_FIXUP = false;
+
+bool ElfFixup::Fixup(File* file, uintptr_t oat_data_begin) {
+ UniquePtr<ElfFile> elf_file(ElfFile::Open(file, true, false));
+ CHECK(elf_file.get() != NULL);
+
+ // Lookup "oatdata" symbol address.
+ ::llvm::ELF::Elf32_Addr oatdata_address = ElfWriter::GetOatDataAddress(elf_file.get());
+ ::llvm::ELF::Elf32_Off base_address = oat_data_begin - oatdata_address;
+
+ if (!FixupDynamic(*elf_file.get(), base_address)) {
+ LOG(WARNING) << "Failed fo fixup .dynamic in " << file->GetPath();
+ return false;
+ }
+ if (!FixupSectionHeaders(*elf_file.get(), base_address)) {
+ LOG(WARNING) << "Failed fo fixup section headers in " << file->GetPath();
+ return false;
+ }
+ if (!FixupProgramHeaders(*elf_file.get(), base_address)) {
+ LOG(WARNING) << "Failed fo fixup program headers in " << file->GetPath();
+ return false;
+ }
+ if (!FixupSymbols(*elf_file.get(), base_address, true)) {
+ LOG(WARNING) << "Failed fo fixup .dynsym in " << file->GetPath();
+ return false;
+ }
+ if (!FixupSymbols(*elf_file.get(), base_address, false)) {
+ LOG(WARNING) << "Failed fo fixup .symtab in " << file->GetPath();
+ return false;
+ }
+ if (!FixupRelocations(*elf_file.get(), base_address)) {
+ LOG(WARNING) << "Failed fo fixup .rel.dyn in " << file->GetPath();
+ return false;
+ }
+ return true;
+}
+
+// MIPS seems to break the rules d_val vs d_ptr even though their values are between DT_LOPROC and DT_HIPROC
+#define DT_MIPS_RLD_VERSION 0x70000001 // d_val
+#define DT_MIPS_TIME_STAMP 0x70000002 // d_val
+#define DT_MIPS_ICHECKSUM 0x70000003 // d_val
+#define DT_MIPS_IVERSION 0x70000004 // d_val
+#define DT_MIPS_FLAGS 0x70000005 // d_val
+#define DT_MIPS_BASE_ADDRESS 0x70000006 // d_ptr
+#define DT_MIPS_CONFLICT 0x70000008 // d_ptr
+#define DT_MIPS_LIBLIST 0x70000009 // d_ptr
+#define DT_MIPS_LOCAL_GOTNO 0x7000000A // d_val
+#define DT_MIPS_CONFLICTNO 0x7000000B // d_val
+#define DT_MIPS_LIBLISTNO 0x70000010 // d_val
+#define DT_MIPS_SYMTABNO 0x70000011 // d_val
+#define DT_MIPS_UNREFEXTNO 0x70000012 // d_val
+#define DT_MIPS_GOTSYM 0x70000013 // d_val
+#define DT_MIPS_HIPAGENO 0x70000014 // d_val
+#define DT_MIPS_RLD_MAP 0x70000016 // d_ptr
+
+bool ElfFixup::FixupDynamic(ElfFile& elf_file, uintptr_t base_address) {
+ // TODO: C++0x auto.
+ for (::llvm::ELF::Elf32_Word i = 0; i < elf_file.GetDynamicNum(); i++) {
+ ::llvm::ELF::Elf32_Dyn& elf_dyn = elf_file.GetDynamic(i);
+ ::llvm::ELF::Elf32_Word d_tag = elf_dyn.d_tag;
+ bool elf_dyn_needs_fixup = false;
+ switch (d_tag) {
+ // case 1: well known d_tag values that imply Elf32_Dyn.d_un contains an address in d_ptr
+ case ::llvm::ELF::DT_PLTGOT:
+ case ::llvm::ELF::DT_HASH:
+ case ::llvm::ELF::DT_STRTAB:
+ case ::llvm::ELF::DT_SYMTAB:
+ case ::llvm::ELF::DT_RELA:
+ case ::llvm::ELF::DT_INIT:
+ case ::llvm::ELF::DT_FINI:
+ case ::llvm::ELF::DT_REL:
+ case ::llvm::ELF::DT_DEBUG:
+ case ::llvm::ELF::DT_JMPREL: {
+ elf_dyn_needs_fixup = true;
+ break;
+ }
+ // d_val or ignored values
+ case ::llvm::ELF::DT_NULL:
+ case ::llvm::ELF::DT_NEEDED:
+ case ::llvm::ELF::DT_PLTRELSZ:
+ case ::llvm::ELF::DT_RELASZ:
+ case ::llvm::ELF::DT_RELAENT:
+ case ::llvm::ELF::DT_STRSZ:
+ case ::llvm::ELF::DT_SYMENT:
+ case ::llvm::ELF::DT_SONAME:
+ case ::llvm::ELF::DT_RPATH:
+ case ::llvm::ELF::DT_SYMBOLIC:
+ case ::llvm::ELF::DT_RELSZ:
+ case ::llvm::ELF::DT_RELENT:
+ case ::llvm::ELF::DT_PLTREL:
+ case ::llvm::ELF::DT_TEXTREL:
+ case ::llvm::ELF::DT_BIND_NOW:
+ case ::llvm::ELF::DT_INIT_ARRAYSZ:
+ case ::llvm::ELF::DT_FINI_ARRAYSZ:
+ case ::llvm::ELF::DT_RUNPATH:
+ case ::llvm::ELF::DT_FLAGS: {
+ break;
+ }
+ // boundary values that should not be used
+ case ::llvm::ELF::DT_ENCODING:
+ case ::llvm::ELF::DT_LOOS:
+ case ::llvm::ELF::DT_HIOS:
+ case ::llvm::ELF::DT_LOPROC:
+ case ::llvm::ELF::DT_HIPROC: {
+ LOG(FATAL) << "Illegal d_tag value 0x" << std::hex << d_tag;
+ break;
+ }
+ default: {
+ // case 2: "regular" DT_* ranges where even d_tag values imply an address in d_ptr
+ if ((::llvm::ELF::DT_ENCODING < d_tag && d_tag < ::llvm::ELF::DT_LOOS)
+ || (::llvm::ELF::DT_LOOS < d_tag && d_tag < ::llvm::ELF::DT_HIOS)
+ || (::llvm::ELF::DT_LOPROC < d_tag && d_tag < ::llvm::ELF::DT_HIPROC)) {
+ // Special case for MIPS which breaks the regular rules between DT_LOPROC and DT_HIPROC
+ if (elf_file.GetHeader().e_machine == ::llvm::ELF::EM_MIPS) {
+ switch (d_tag) {
+ case DT_MIPS_RLD_VERSION:
+ case DT_MIPS_TIME_STAMP:
+ case DT_MIPS_ICHECKSUM:
+ case DT_MIPS_IVERSION:
+ case DT_MIPS_FLAGS:
+ case DT_MIPS_LOCAL_GOTNO:
+ case DT_MIPS_CONFLICTNO:
+ case DT_MIPS_LIBLISTNO:
+ case DT_MIPS_SYMTABNO:
+ case DT_MIPS_UNREFEXTNO:
+ case DT_MIPS_GOTSYM:
+ case DT_MIPS_HIPAGENO: {
+ break;
+ }
+ case DT_MIPS_BASE_ADDRESS:
+ case DT_MIPS_CONFLICT:
+ case DT_MIPS_LIBLIST:
+ case DT_MIPS_RLD_MAP: {
+ elf_dyn_needs_fixup = true;
+ break;
+ }
+ default: {
+ LOG(FATAL) << "Unknown MIPS d_tag value 0x" << std::hex << d_tag;
+ break;
+ }
+ }
+ } else if ((elf_dyn.d_tag % 2) == 0) {
+ elf_dyn_needs_fixup = true;
+ }
+ } else {
+ LOG(FATAL) << "Unknown d_tag value 0x" << std::hex << d_tag;
+ }
+ break;
+ }
+ }
+ if (elf_dyn_needs_fixup) {
+ uint32_t d_ptr = elf_dyn.d_un.d_ptr;
+ if (DEBUG_FIXUP) {
+ LOG(INFO) << StringPrintf("In %s moving Elf32_Dyn[%d] from 0x%08x to 0x%08x",
+ elf_file.GetFile().GetPath().c_str(), i,
+ d_ptr, d_ptr + base_address);
+ }
+ d_ptr += base_address;
+ elf_dyn.d_un.d_ptr = d_ptr;
+ }
+ }
+ return true;
+}
+
+bool ElfFixup::FixupSectionHeaders(ElfFile& elf_file, uintptr_t base_address) {
+ for (::llvm::ELF::Elf32_Word i = 0; i < elf_file.GetSectionHeaderNum(); i++) {
+ ::llvm::ELF::Elf32_Shdr& sh = elf_file.GetSectionHeader(i);
+ // 0 implies that the section will not exist in the memory of the process
+ if (sh.sh_addr == 0) {
+ continue;
+ }
+ if (DEBUG_FIXUP) {
+ LOG(INFO) << StringPrintf("In %s moving Elf32_Shdr[%d] from 0x%08x to 0x%08x",
+ elf_file.GetFile().GetPath().c_str(), i,
+ sh.sh_addr, sh.sh_addr + base_address);
+ }
+ sh.sh_addr += base_address;
+ }
+ return true;
+}
+
+bool ElfFixup::FixupProgramHeaders(ElfFile& elf_file, uintptr_t base_address) {
+ // TODO: ELFObjectFile doesn't have give to Elf32_Phdr, so we do that ourselves for now.
+ for (::llvm::ELF::Elf32_Word i = 0; i < elf_file.GetProgramHeaderNum(); i++) {
+ ::llvm::ELF::Elf32_Phdr& ph = elf_file.GetProgramHeader(i);
+ CHECK_EQ(ph.p_vaddr, ph.p_paddr) << elf_file.GetFile().GetPath() << " i=" << i;
+ CHECK((ph.p_align == 0) || (0 == ((ph.p_vaddr - ph.p_offset) & (ph.p_align - 1))))
+ << elf_file.GetFile().GetPath() << " i=" << i;
+ if (DEBUG_FIXUP) {
+ LOG(INFO) << StringPrintf("In %s moving Elf32_Phdr[%d] from 0x%08x to 0x%08x",
+ elf_file.GetFile().GetPath().c_str(), i,
+ ph.p_vaddr, ph.p_vaddr + base_address);
+ }
+ ph.p_vaddr += base_address;
+ ph.p_paddr += base_address;
+ CHECK((ph.p_align == 0) || (0 == ((ph.p_vaddr - ph.p_offset) & (ph.p_align - 1))))
+ << elf_file.GetFile().GetPath() << " i=" << i;
+ }
+ return true;
+}
+
+bool ElfFixup::FixupSymbols(ElfFile& elf_file, uintptr_t base_address, bool dynamic) {
+ ::llvm::ELF::Elf32_Word section_type = dynamic ? ::llvm::ELF::SHT_DYNSYM : ::llvm::ELF::SHT_SYMTAB;
+ // TODO: Unfortunate ELFObjectFile has protected symbol access, so use ElfFile
+ ::llvm::ELF::Elf32_Shdr* symbol_section = elf_file.FindSectionByType(section_type);
+ if (symbol_section == NULL) {
+ // file is missing optional .symtab
+ CHECK(!dynamic) << elf_file.GetFile().GetPath();
+ return true;
+ }
+ for (uint32_t i = 0; i < elf_file.GetSymbolNum(*symbol_section); i++) {
+ ::llvm::ELF::Elf32_Sym& symbol = elf_file.GetSymbol(section_type, i);
+ if (symbol.st_value != 0) {
+ if (DEBUG_FIXUP) {
+ LOG(INFO) << StringPrintf("In %s moving Elf32_Sym[%d] from 0x%08x to 0x%08x",
+ elf_file.GetFile().GetPath().c_str(), i,
+ symbol.st_value, symbol.st_value + base_address);
+ }
+ symbol.st_value += base_address;
+ }
+ }
+ return true;
+}
+
+bool ElfFixup::FixupRelocations(ElfFile& elf_file, uintptr_t base_address) {
+ for (llvm::ELF::Elf32_Word i = 0; i < elf_file.GetSectionHeaderNum(); i++) {
+ llvm::ELF::Elf32_Shdr& sh = elf_file.GetSectionHeader(i);
+ if (sh.sh_type == llvm::ELF::SHT_REL) {
+ for (uint32_t i = 0; i < elf_file.GetRelNum(sh); i++) {
+ llvm::ELF::Elf32_Rel& rel = elf_file.GetRel(sh, i);
+ if (DEBUG_FIXUP) {
+ LOG(INFO) << StringPrintf("In %s moving Elf32_Rel[%d] from 0x%08x to 0x%08x",
+ elf_file.GetFile().GetPath().c_str(), i,
+ rel.r_offset, rel.r_offset + base_address);
+ }
+ rel.r_offset += base_address;
+ }
+ } else if (sh.sh_type == llvm::ELF::SHT_RELA) {
+ for (uint32_t i = 0; i < elf_file.GetRelaNum(sh); i++) {
+ llvm::ELF::Elf32_Rela& rela = elf_file.GetRela(sh, i);
+ if (DEBUG_FIXUP) {
+ LOG(INFO) << StringPrintf("In %s moving Elf32_Rela[%d] from 0x%08x to 0x%08x",
+ elf_file.GetFile().GetPath().c_str(), i,
+ rela.r_offset, rela.r_offset + base_address);
+ }
+ rela.r_offset += base_address;
+ }
+ }
+ }
+ return true;
+}
+
+} // namespace art