/*
* Copyright (C) 2014 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 "patchoat.h"
#include <stdio.h>
#include <stdlib.h>
#include <sys/file.h>
#include <sys/stat.h>
#include <unistd.h>
#include <string>
#include <vector>
#include "base/scoped_flock.h"
#include "base/stringpiece.h"
#include "base/stringprintf.h"
#include "elf_utils.h"
#include "elf_file.h"
#include "gc/space/image_space.h"
#include "image.h"
#include "instruction_set.h"
#include "mirror/art_field.h"
#include "mirror/art_field-inl.h"
#include "mirror/art_method.h"
#include "mirror/art_method-inl.h"
#include "mirror/object.h"
#include "mirror/object-inl.h"
#include "mirror/reference.h"
#include "noop_compiler_callbacks.h"
#include "offsets.h"
#include "os.h"
#include "runtime.h"
#include "scoped_thread_state_change.h"
#include "thread.h"
#include "utils.h"
namespace art {
static InstructionSet ElfISAToInstructionSet(Elf32_Word isa) {
switch (isa) {
case EM_ARM:
return kArm;
case EM_AARCH64:
return kArm64;
case EM_386:
return kX86;
case EM_X86_64:
return kX86_64;
case EM_MIPS:
return kMips;
default:
return kNone;
}
}
static bool LocationToFilename(const std::string& location, InstructionSet isa,
std::string* filename) {
bool has_system = false;
bool has_cache = false;
// image_location = /system/framework/boot.art
// system_image_filename = /system/framework/<image_isa>/boot.art
std::string system_filename(GetSystemImageFilename(location.c_str(), isa));
if (OS::FileExists(system_filename.c_str())) {
has_system = true;
}
bool have_android_data = false;
bool dalvik_cache_exists = false;
bool is_global_cache = false;
std::string dalvik_cache;
GetDalvikCache(GetInstructionSetString(isa), false, &dalvik_cache,
&have_android_data, &dalvik_cache_exists, &is_global_cache);
std::string cache_filename;
if (have_android_data && dalvik_cache_exists) {
// Always set output location even if it does not exist,
// so that the caller knows where to create the image.
//
// image_location = /system/framework/boot.art
// *image_filename = /data/dalvik-cache/<image_isa>/boot.art
std::string error_msg;
if (GetDalvikCacheFilename(location.c_str(), dalvik_cache.c_str(),
&cache_filename, &error_msg)) {
has_cache = true;
}
}
if (has_system) {
*filename = system_filename;
return true;
} else if (has_cache) {
*filename = cache_filename;
return true;
} else {
return false;
}
}
bool PatchOat::Patch(const std::string& image_location, off_t delta,
File* output_image, InstructionSet isa,
TimingLogger* timings) {
CHECK(Runtime::Current() == nullptr);
CHECK(output_image != nullptr);
CHECK_GE(output_image->Fd(), 0);
CHECK(!image_location.empty()) << "image file must have a filename.";
CHECK_NE(isa, kNone);
TimingLogger::ScopedTiming t("Runtime Setup", timings);
const char *isa_name = GetInstructionSetString(isa);
std::string image_filename;
if (!LocationToFilename(image_location, isa, &image_filename)) {
LOG(ERROR) << "Unable to find image at location " << image_location;
return false;
}
std::unique_ptr<File> input_image(OS::OpenFileForReading(image_filename.c_str()));
if (input_image.get() == nullptr) {
LOG(ERROR) << "unable to open input image file at " << image_filename
<< " for location " << image_location;
return false;
}
int64_t image_len = input_image->GetLength();
if (image_len < 0) {
LOG(ERROR) << "Error while getting image length";
return false;
}
ImageHeader image_header;
if (sizeof(image_header) != input_image->Read(reinterpret_cast<char*>(&image_header),
sizeof(image_header), 0)) {
LOG(ERROR) << "Unable to read image header from image file " << input_image->GetPath();
return false;
}
/*bool is_image_pic = */IsImagePic(image_header, input_image->GetPath());
// Nothing special to do right now since the image always needs to get patched.
// Perhaps in some far-off future we may have images with relative addresses that are true-PIC.
// Set up the runtime
RuntimeOptions options;
NoopCompilerCallbacks callbacks;
options.push_back(std::make_pair("compilercallbacks", &callbacks));
std::string img = "-Ximage:" + image_location;
options.push_back(std::make_pair(img.c_str(), nullptr));
options.push_back(std::make_pair("imageinstructionset", reinterpret_cast<const void*>(isa_name)));
if (!Runtime::Create(options, false)) {
LOG(ERROR) << "Unable to initialize runtime";
return false;
}
// Runtime::Create acquired the mutator_lock_ that is normally given away when we Runtime::Start,
// give it away now and then switch to a more manageable ScopedObjectAccess.
Thread::Current()->TransitionFromRunnableToSuspended(kNative);
ScopedObjectAccess soa(Thread::Current());
t.NewTiming("Image and oat Patching setup");
// Create the map where we will write the image patches to.
std::string error_msg;
std::unique_ptr<MemMap> image(MemMap::MapFile(image_len, PROT_READ | PROT_WRITE, MAP_PRIVATE,
input_image->Fd(), 0,
input_image->GetPath().c_str(),
&error_msg));
if (image.get() == nullptr) {
LOG(ERROR) << "unable to map image file " << input_image->GetPath() << " : " << error_msg;
return false;
}
gc::space::ImageSpace* ispc = Runtime::Current()->GetHeap()->GetImageSpace();
PatchOat p(isa, image.release(), ispc->GetLiveBitmap(), ispc->GetMemMap(),
delta, timings);
t.NewTiming("Patching files");
if (!p.PatchImage()) {
LOG(ERROR) << "Failed to patch image file " << input_image->GetPath();
return false;
}
t.NewTiming("Writing files");
if (!p.WriteImage(output_image)) {
return false;
}
return true;
}
bool PatchOat::Patch(File* input_oat, const std::string& image_location, off_t delta,
File* output_oat, File* output_image, InstructionSet isa,
TimingLogger* timings,
bool output_oat_opened_from_fd,
bool new_oat_out) {
CHECK(Runtime::Current() == nullptr);
CHECK(output_image != nullptr);
CHECK_GE(output_image->Fd(), 0);
CHECK(input_oat != nullptr);
CHECK(output_oat != nullptr);
CHECK_GE(input_oat->Fd(), 0);
CHECK_GE(output_oat->Fd(), 0);
CHECK(!image_location.empty()) << "image file must have a filename.";
TimingLogger::ScopedTiming t("Runtime Setup", timings);
if (isa == kNone) {
Elf32_Ehdr elf_hdr;
if (sizeof(elf_hdr) != input_oat->Read(reinterpret_cast<char*>(&elf_hdr), sizeof(elf_hdr), 0)) {
LOG(ERROR) << "unable to read elf header";
return false;
}
isa = ElfISAToInstructionSet(elf_hdr.e_machine);
}
const char* isa_name = GetInstructionSetString(isa);
std::string image_filename;
if (!LocationToFilename(image_location, isa, &image_filename)) {
LOG(ERROR) << "Unable to find image at location " << image_location;
return false;
}
std::unique_ptr<File> input_image(OS::OpenFileForReading(image_filename.c_str()));
if (input_image.get() == nullptr) {
LOG(ERROR) << "unable to open input image file at " << image_filename
<< " for location " << image_location;
return false;
}
int64_t image_len = input_image->GetLength();
if (image_len < 0) {
LOG(ERROR) << "Error while getting image length";
return false;
}
ImageHeader image_header;
if (sizeof(image_header) != input_image->Read(reinterpret_cast<char*>(&image_header),
sizeof(image_header), 0)) {
LOG(ERROR) << "Unable to read image header from image file " << input_image->GetPath();
}
/*bool is_image_pic = */IsImagePic(image_header, input_image->GetPath());
// Nothing special to do right now since the image always needs to get patched.
// Perhaps in some far-off future we may have images with relative addresses that are true-PIC.
// Set up the runtime
RuntimeOptions options;
NoopCompilerCallbacks callbacks;
options.push_back(std::make_pair("compilercallbacks", &callbacks));
std::string img = "-Ximage:" + image_location;
options.push_back(std::make_pair(img.c_str(), nullptr));
options.push_back(std::make_pair("imageinstructionset", reinterpret_cast<const void*>(isa_name)));
if (!Runtime::Create(options, false)) {
LOG(ERROR) << "Unable to initialize runtime";
return false;
}
// Runtime::Create acquired the mutator_lock_ that is normally given away when we Runtime::Start,
// give it away now and then switch to a more manageable ScopedObjectAccess.
Thread::Current()->TransitionFromRunnableToSuspended(kNative);
ScopedObjectAccess soa(Thread::Current());
t.NewTiming("Image and oat Patching setup");
// Create the map where we will write the image patches to.
std::string error_msg;
std::unique_ptr<MemMap> image(MemMap::MapFile(image_len, PROT_READ | PROT_WRITE, MAP_PRIVATE,
input_image->Fd(), 0,
input_image->GetPath().c_str(),
&error_msg));
if (image.get() == nullptr) {
LOG(ERROR) << "unable to map image file " << input_image->GetPath() << " : " << error_msg;
return false;
}
gc::space::ImageSpace* ispc = Runtime::Current()->GetHeap()->GetImageSpace();
std::unique_ptr<ElfFile> elf(ElfFile::Open(input_oat,
PROT_READ | PROT_WRITE, MAP_PRIVATE, &error_msg));
if (elf.get() == nullptr) {
LOG(ERROR) << "unable to open oat file " << input_oat->GetPath() << " : " << error_msg;
return false;
}
bool skip_patching_oat = false;
MaybePic is_oat_pic = IsOatPic(elf.get());
if (is_oat_pic >= ERROR_FIRST) {
// Error logged by IsOatPic
return false;
} else if (is_oat_pic == PIC) {
// Do not need to do ELF-file patching. Create a symlink and skip the ELF patching.
if (!ReplaceOatFileWithSymlink(input_oat->GetPath(),
output_oat->GetPath(),
output_oat_opened_from_fd,
new_oat_out)) {
// Errors already logged by above call.
return false;
}
// Don't patch the OAT, since we just symlinked it. Image still needs patching.
skip_patching_oat = true;
} else {
CHECK(is_oat_pic == NOT_PIC);
}
PatchOat p(isa, elf.release(), image.release(), ispc->GetLiveBitmap(), ispc->GetMemMap(),
delta, timings);
t.NewTiming("Patching files");
if (!skip_patching_oat && !p.PatchElf()) {
LOG(ERROR) << "Failed to patch oat file " << input_oat->GetPath();
return false;
}
if (!p.PatchImage()) {
LOG(ERROR) << "Failed to patch image file " << input_image->GetPath();
return false;
}
t.NewTiming("Writing files");
if (!skip_patching_oat && !p.WriteElf(output_oat)) {
LOG(ERROR) << "Failed to write oat file " << input_oat->GetPath();
return false;
}
if (!p.WriteImage(output_image)) {
LOG(ERROR) << "Failed to write image file " << input_image->GetPath();
return false;
}
return true;
}
bool PatchOat::WriteElf(File* out) {
TimingLogger::ScopedTiming t("Writing Elf File", timings_);
CHECK(oat_file_.get() != nullptr);
CHECK(out != nullptr);
size_t expect = oat_file_->Size();
if (out->WriteFully(reinterpret_cast<char*>(oat_file_->Begin()), expect) &&
out->SetLength(expect) == 0) {
return true;
} else {
LOG(ERROR) << "Writing to oat file " << out->GetPath() << " failed.";
return false;
}
}
bool PatchOat::WriteImage(File* out) {
TimingLogger::ScopedTiming t("Writing image File", timings_);
std::string error_msg;
ScopedFlock img_flock;
img_flock.Init(out, &error_msg);
CHECK(image_ != nullptr);
CHECK(out != nullptr);
size_t expect = image_->Size();
if (out->WriteFully(reinterpret_cast<char*>(image_->Begin()), expect) &&
out->SetLength(expect) == 0) {
return true;
} else {
LOG(ERROR) << "Writing to image file " << out->GetPath() << " failed.";
return false;
}
}
bool PatchOat::IsImagePic(const ImageHeader& image_header, const std::string& image_path) {
if (!image_header.CompilePic()) {
if (kIsDebugBuild) {
LOG(INFO) << "image at location " << image_path << " was *not* compiled pic";
}
return false;
}
if (kIsDebugBuild) {
LOG(INFO) << "image at location " << image_path << " was compiled PIC";
}
return true;
}
PatchOat::MaybePic PatchOat::IsOatPic(const ElfFile* oat_in) {
if (oat_in == nullptr) {
LOG(ERROR) << "No ELF input oat fie available";
return ERROR_OAT_FILE;
}
const std::string& file_path = oat_in->GetFile().GetPath();
const OatHeader* oat_header = GetOatHeader(oat_in);
if (oat_header == nullptr) {
LOG(ERROR) << "Failed to find oat header in oat file " << file_path;
return ERROR_OAT_FILE;
}
if (!oat_header->IsValid()) {
LOG(ERROR) << "Elf file " << file_path << " has an invalid oat header";
return ERROR_OAT_FILE;
}
bool is_pic = oat_header->IsPic();
if (kIsDebugBuild) {
LOG(INFO) << "Oat file at " << file_path << " is " << (is_pic ? "PIC" : "not pic");
}
return is_pic ? PIC : NOT_PIC;
}
bool PatchOat::ReplaceOatFileWithSymlink(const std::string& input_oat_filename,
const std::string& output_oat_filename,
bool output_oat_opened_from_fd,
bool new_oat_out) {
// Need a file when we are PIC, since we symlink over it. Refusing to symlink into FD.
if (output_oat_opened_from_fd) {
// TODO: installd uses --output-oat-fd. Should we change class linking logic for PIC?
LOG(ERROR) << "No output oat filename specified, needs filename for when we are PIC";
return false;
}
// Image was PIC. Create symlink where the oat is supposed to go.
if (!new_oat_out) {
LOG(ERROR) << "Oat file " << output_oat_filename << " already exists, refusing to overwrite";
return false;
}
// Delete the original file, since we won't need it.
TEMP_FAILURE_RETRY(unlink(output_oat_filename.c_str()));
// Create a symlink from the old oat to the new oat
if (symlink(input_oat_filename.c_str(), output_oat_filename.c_str()) < 0) {
int err = errno;
LOG(ERROR) << "Failed to create symlink at " << output_oat_filename
<< " error(" << err << "): " << strerror(err);
return false;
}
if (kIsDebugBuild) {
LOG(INFO) << "Created symlink " << output_oat_filename << " -> " << input_oat_filename;
}
return true;
}
bool PatchOat::PatchImage() {
ImageHeader* image_header = reinterpret_cast<ImageHeader*>(image_->Begin());
CHECK_GT(image_->Size(), sizeof(ImageHeader));
// These are the roots from the original file.
mirror::Object* img_roots = image_header->GetImageRoots();
image_header->RelocateImage(delta_);
VisitObject(img_roots);
if (!image_header->IsValid()) {
LOG(ERROR) << "reloction renders image header invalid";
return false;
}
{
TimingLogger::ScopedTiming t("Walk Bitmap", timings_);
// Walk the bitmap.
WriterMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_);
bitmap_->Walk(PatchOat::BitmapCallback, this);
}
return true;
}
bool PatchOat::InHeap(mirror::Object* o) {
uintptr_t begin = reinterpret_cast<uintptr_t>(heap_->Begin());
uintptr_t end = reinterpret_cast<uintptr_t>(heap_->End());
uintptr_t obj = reinterpret_cast<uintptr_t>(o);
return o == nullptr || (begin <= obj && obj < end);
}
void PatchOat::PatchVisitor::operator() (mirror::Object* obj, MemberOffset off,
bool is_static_unused) const {
mirror::Object* referent = obj->GetFieldObject<mirror::Object, kVerifyNone>(off);
DCHECK(patcher_->InHeap(referent)) << "Referent is not in the heap.";
mirror::Object* moved_object = patcher_->RelocatedAddressOf(referent);
copy_->SetFieldObjectWithoutWriteBarrier<false, true, kVerifyNone>(off, moved_object);
}
void PatchOat::PatchVisitor::operator() (mirror::Class* cls, mirror::Reference* ref) const {
MemberOffset off = mirror::Reference::ReferentOffset();
mirror::Object* referent = ref->GetReferent();
DCHECK(patcher_->InHeap(referent)) << "Referent is not in the heap.";
mirror::Object* moved_object = patcher_->RelocatedAddressOf(referent);
copy_->SetFieldObjectWithoutWriteBarrier<false, true, kVerifyNone>(off, moved_object);
}
mirror::Object* PatchOat::RelocatedCopyOf(mirror::Object* obj) {
if (obj == nullptr) {
return nullptr;
}
DCHECK_GT(reinterpret_cast<uintptr_t>(obj), reinterpret_cast<uintptr_t>(heap_->Begin()));
DCHECK_LT(reinterpret_cast<uintptr_t>(obj), reinterpret_cast<uintptr_t>(heap_->End()));
uintptr_t heap_off =
reinterpret_cast<uintptr_t>(obj) - reinterpret_cast<uintptr_t>(heap_->Begin());
DCHECK_LT(heap_off, image_->Size());
return reinterpret_cast<mirror::Object*>(image_->Begin() + heap_off);
}
mirror::Object* PatchOat::RelocatedAddressOf(mirror::Object* obj) {
if (obj == nullptr) {
return nullptr;
} else {
return reinterpret_cast<mirror::Object*>(reinterpret_cast<byte*>(obj) + delta_);
}
}
const OatHeader* PatchOat::GetOatHeader(const ElfFile* elf_file) {
auto rodata_sec = elf_file->FindSectionByName(".rodata");
if (rodata_sec == nullptr) {
return nullptr;
}
OatHeader* oat_header = reinterpret_cast<OatHeader*>(elf_file->Begin() + rodata_sec->sh_offset);
return oat_header;
}
// Called by BitmapCallback
void PatchOat::VisitObject(mirror::Object* object) {
mirror::Object* copy = RelocatedCopyOf(object);
CHECK(copy != nullptr);
if (kUseBakerOrBrooksReadBarrier) {
object->AssertReadBarrierPointer();
if (kUseBrooksReadBarrier) {
mirror::Object* moved_to = RelocatedAddressOf(object);
copy->SetReadBarrierPointer(moved_to);
DCHECK_EQ(copy->GetReadBarrierPointer(), moved_to);
}
}
PatchOat::PatchVisitor visitor(this, copy);
object->VisitReferences<true, kVerifyNone>(visitor, visitor);
if (object->IsArtMethod<kVerifyNone>()) {
FixupMethod(down_cast<mirror::ArtMethod*>(object), down_cast<mirror::ArtMethod*>(copy));
}
}
void PatchOat::FixupMethod(mirror::ArtMethod* object, mirror::ArtMethod* copy) {
const size_t pointer_size = InstructionSetPointerSize(isa_);
// Just update the entry points if it looks like we should.
// TODO: sanity check all the pointers' values
#if defined(ART_USE_PORTABLE_COMPILER)
uintptr_t portable = reinterpret_cast<uintptr_t>(
object->GetEntryPointFromPortableCompiledCodePtrSize<kVerifyNone>(pointer_size));
if (portable != 0) {
copy->SetEntryPointFromPortableCompiledCodePtrSize(reinterpret_cast<void*>(portable + delta_),
pointer_size);
}
#endif
uintptr_t quick= reinterpret_cast<uintptr_t>(
object->GetEntryPointFromQuickCompiledCodePtrSize<kVerifyNone>(pointer_size));
if (quick != 0) {
copy->SetEntryPointFromQuickCompiledCodePtrSize(reinterpret_cast<void*>(quick + delta_),
pointer_size);
}
uintptr_t interpreter = reinterpret_cast<uintptr_t>(
object->GetEntryPointFromInterpreterPtrSize<kVerifyNone>(pointer_size));
if (interpreter != 0) {
copy->SetEntryPointFromInterpreterPtrSize(
reinterpret_cast<mirror::EntryPointFromInterpreter*>(interpreter + delta_), pointer_size);
}
uintptr_t native_method = reinterpret_cast<uintptr_t>(
object->GetEntryPointFromJniPtrSize(pointer_size));
if (native_method != 0) {
copy->SetEntryPointFromJniPtrSize(reinterpret_cast<void*>(native_method + delta_),
pointer_size);
}
}
bool PatchOat::Patch(File* input_oat, off_t delta, File* output_oat, TimingLogger* timings,
bool output_oat_opened_from_fd, bool new_oat_out) {
CHECK(input_oat != nullptr);
CHECK(output_oat != nullptr);
CHECK_GE(input_oat->Fd(), 0);
CHECK_GE(output_oat->Fd(), 0);
TimingLogger::ScopedTiming t("Setup Oat File Patching", timings);
std::string error_msg;
std::unique_ptr<ElfFile> elf(ElfFile::Open(input_oat,
PROT_READ | PROT_WRITE, MAP_PRIVATE, &error_msg));
if (elf.get() == nullptr) {
LOG(ERROR) << "unable to open oat file " << input_oat->GetPath() << " : " << error_msg;
return false;
}
MaybePic is_oat_pic = IsOatPic(elf.get());
if (is_oat_pic >= ERROR_FIRST) {
// Error logged by IsOatPic
return false;
} else if (is_oat_pic == PIC) {
// Do not need to do ELF-file patching. Create a symlink and skip the rest.
// Any errors will be logged by the function call.
return ReplaceOatFileWithSymlink(input_oat->GetPath(),
output_oat->GetPath(),
output_oat_opened_from_fd,
new_oat_out);
} else {
CHECK(is_oat_pic == NOT_PIC);
}
PatchOat p(elf.release(), delta, timings);
t.NewTiming("Patch Oat file");
if (!p.PatchElf()) {
return false;
}
t.NewTiming("Writing oat file");
if (!p.WriteElf(output_oat)) {
return false;
}
return true;
}
bool PatchOat::CheckOatFile() {
Elf32_Shdr* patches_sec = oat_file_->FindSectionByName(".oat_patches");
if (patches_sec == nullptr) {
return false;
}
if (patches_sec->sh_type != SHT_OAT_PATCH) {
return false;
}
uintptr_t* patches = reinterpret_cast<uintptr_t*>(oat_file_->Begin() + patches_sec->sh_offset);
uintptr_t* patches_end = patches + (patches_sec->sh_size/sizeof(uintptr_t));
Elf32_Shdr* oat_data_sec = oat_file_->FindSectionByName(".rodata");
Elf32_Shdr* oat_text_sec = oat_file_->FindSectionByName(".text");
if (oat_data_sec == nullptr) {
return false;
}
if (oat_text_sec == nullptr) {
return false;
}
if (oat_text_sec->sh_offset <= oat_data_sec->sh_offset) {
return false;
}
for (; patches < patches_end; patches++) {
if (oat_text_sec->sh_size <= *patches) {
return false;
}
}
return true;
}
bool PatchOat::PatchOatHeader() {
Elf32_Shdr *rodata_sec = oat_file_->FindSectionByName(".rodata");
if (rodata_sec == nullptr) {
return false;
}
OatHeader* oat_header = reinterpret_cast<OatHeader*>(oat_file_->Begin() + rodata_sec->sh_offset);
if (!oat_header->IsValid()) {
LOG(ERROR) << "Elf file " << oat_file_->GetFile().GetPath() << " has an invalid oat header";
return false;
}
oat_header->RelocateOat(delta_);
return true;
}
bool PatchOat::PatchElf() {
TimingLogger::ScopedTiming t("Fixup Elf Text Section", timings_);
if (!PatchTextSection()) {
return false;
}
if (!PatchOatHeader()) {
return false;
}
bool need_fixup = false;
t.NewTiming("Fixup Elf Headers");
// Fixup Phdr's
for (unsigned int i = 0; i < oat_file_->GetProgramHeaderNum(); i++) {
Elf32_Phdr* hdr = oat_file_->GetProgramHeader(i);
CHECK(hdr != nullptr);
if (hdr->p_vaddr != 0 && hdr->p_vaddr != hdr->p_offset) {
need_fixup = true;
hdr->p_vaddr += delta_;
}
if (hdr->p_paddr != 0 && hdr->p_paddr != hdr->p_offset) {
need_fixup = true;
hdr->p_paddr += delta_;
}
}
if (!need_fixup) {
// This was never passed through ElfFixup so all headers/symbols just have their offset as
// their addr. Therefore we do not need to update these parts.
return true;
}
t.NewTiming("Fixup Section Headers");
for (unsigned int i = 0; i < oat_file_->GetSectionHeaderNum(); i++) {
Elf32_Shdr* hdr = oat_file_->GetSectionHeader(i);
CHECK(hdr != nullptr);
if (hdr->sh_addr != 0) {
hdr->sh_addr += delta_;
}
}
t.NewTiming("Fixup Dynamics");
for (Elf32_Word i = 0; i < oat_file_->GetDynamicNum(); i++) {
Elf32_Dyn& dyn = oat_file_->GetDynamic(i);
if (IsDynamicSectionPointer(dyn.d_tag, oat_file_->GetHeader().e_machine)) {
dyn.d_un.d_ptr += delta_;
}
}
t.NewTiming("Fixup Elf Symbols");
// Fixup dynsym
Elf32_Shdr* dynsym_sec = oat_file_->FindSectionByName(".dynsym");
CHECK(dynsym_sec != nullptr);
if (!PatchSymbols(dynsym_sec)) {
return false;
}
// Fixup symtab
Elf32_Shdr* symtab_sec = oat_file_->FindSectionByName(".symtab");
if (symtab_sec != nullptr) {
if (!PatchSymbols(symtab_sec)) {
return false;
}
}
return true;
}
bool PatchOat::PatchSymbols(Elf32_Shdr* section) {
Elf32_Sym* syms = reinterpret_cast<Elf32_Sym*>(oat_file_->Begin() + section->sh_offset);
const Elf32_Sym* last_sym =
reinterpret_cast<Elf32_Sym*>(oat_file_->Begin() + section->sh_offset + section->sh_size);
CHECK_EQ(section->sh_size % sizeof(Elf32_Sym), 0u)
<< "Symtab section size is not multiple of symbol size";
for (; syms < last_sym; syms++) {
uint8_t sttype = ELF32_ST_TYPE(syms->st_info);
Elf32_Word shndx = syms->st_shndx;
if (shndx != SHN_ABS && shndx != SHN_COMMON && shndx != SHN_UNDEF &&
(sttype == STT_FUNC || sttype == STT_OBJECT)) {
CHECK_NE(syms->st_value, 0u);
syms->st_value += delta_;
}
}
return true;
}
bool PatchOat::PatchTextSection() {
Elf32_Shdr* patches_sec = oat_file_->FindSectionByName(".oat_patches");
if (patches_sec == nullptr) {
LOG(ERROR) << ".oat_patches section not found. Aborting patch";
return false;
}
DCHECK(CheckOatFile()) << "Oat file invalid";
CHECK_EQ(patches_sec->sh_type, SHT_OAT_PATCH) << "Unexpected type of .oat_patches";
uintptr_t* patches = reinterpret_cast<uintptr_t*>(oat_file_->Begin() + patches_sec->sh_offset);
uintptr_t* patches_end = patches + (patches_sec->sh_size/sizeof(uintptr_t));
Elf32_Shdr* oat_text_sec = oat_file_->FindSectionByName(".text");
CHECK(oat_text_sec != nullptr);
byte* to_patch = oat_file_->Begin() + oat_text_sec->sh_offset;
uintptr_t to_patch_end = reinterpret_cast<uintptr_t>(to_patch) + oat_text_sec->sh_size;
for (; patches < patches_end; patches++) {
CHECK_LT(*patches, oat_text_sec->sh_size) << "Bad Patch";
uint32_t* patch_loc = reinterpret_cast<uint32_t*>(to_patch + *patches);
CHECK_LT(reinterpret_cast<uintptr_t>(patch_loc), to_patch_end);
*patch_loc += delta_;
}
return true;
}
static int orig_argc;
static char** orig_argv;
static std::string CommandLine() {
std::vector<std::string> command;
for (int i = 0; i < orig_argc; ++i) {
command.push_back(orig_argv[i]);
}
return Join(command, ' ');
}
static void UsageErrorV(const char* fmt, va_list ap) {
std::string error;
StringAppendV(&error, fmt, ap);
LOG(ERROR) << error;
}
static void UsageError(const char* fmt, ...) {
va_list ap;
va_start(ap, fmt);
UsageErrorV(fmt, ap);
va_end(ap);
}
static void Usage(const char *fmt, ...) {
va_list ap;
va_start(ap, fmt);
UsageErrorV(fmt, ap);
va_end(ap);
UsageError("Command: %s", CommandLine().c_str());
UsageError("Usage: patchoat [options]...");
UsageError("");
UsageError(" --instruction-set=<isa>: Specifies the instruction set the patched code is");
UsageError(" compiled for. Required if you use --input-oat-location");
UsageError("");
UsageError(" --input-oat-file=<file.oat>: Specifies the exact filename of the oat file to be");
UsageError(" patched.");
UsageError("");
UsageError(" --input-oat-fd=<file-descriptor>: Specifies the file-descriptor of the oat file");
UsageError(" to be patched.");
UsageError("");
UsageError(" --input-oat-location=<file.oat>: Specifies the 'location' to read the patched");
UsageError(" oat file from. If used one must also supply the --instruction-set");
UsageError("");
UsageError(" --input-image-location=<file.art>: Specifies the 'location' of the image file to");
UsageError(" be patched. If --instruction-set is not given it will use the instruction set");
UsageError(" extracted from the --input-oat-file.");
UsageError("");
UsageError(" --output-oat-file=<file.oat>: Specifies the exact file to write the patched oat");
UsageError(" file to.");
UsageError("");
UsageError(" --output-oat-fd=<file-descriptor>: Specifies the file-descriptor to write the");
UsageError(" the patched oat file to.");
UsageError("");
UsageError(" --output-image-file=<file.art>: Specifies the exact file to write the patched");
UsageError(" image file to.");
UsageError("");
UsageError(" --output-image-fd=<file-descriptor>: Specifies the file-descriptor to write the");
UsageError(" the patched image file to.");
UsageError("");
UsageError(" --orig-base-offset=<original-base-offset>: Specify the base offset the input file");
UsageError(" was compiled with. This is needed if one is specifying a --base-offset");
UsageError("");
UsageError(" --base-offset=<new-base-offset>: Specify the base offset we will repatch the");
UsageError(" given files to use. This requires that --orig-base-offset is also given.");
UsageError("");
UsageError(" --base-offset-delta=<delta>: Specify the amount to change the old base-offset by.");
UsageError(" This value may be negative.");
UsageError("");
UsageError(" --patched-image-file=<file.art>: Use the same patch delta as was used to patch");
UsageError(" the given image file.");
UsageError("");
UsageError(" --patched-image-location=<file.art>: Use the same patch delta as was used to");
UsageError(" patch the given image location. If used one must also specify the");
UsageError(" --instruction-set flag. It will search for this image in the same way that");
UsageError(" is done when loading one.");
UsageError("");
UsageError(" --lock-output: Obtain a flock on output oat file before starting.");
UsageError("");
UsageError(" --no-lock-output: Do not attempt to obtain a flock on output oat file.");
UsageError("");
UsageError(" --dump-timings: dump out patch timing information");
UsageError("");
UsageError(" --no-dump-timings: do not dump out patch timing information");
UsageError("");
exit(EXIT_FAILURE);
}
static bool ReadBaseDelta(const char* name, off_t* delta, std::string* error_msg) {
CHECK(name != nullptr);
CHECK(delta != nullptr);
std::unique_ptr<File> file;
if (OS::FileExists(name)) {
file.reset(OS::OpenFileForReading(name));
if (file.get() == nullptr) {
*error_msg = "Failed to open file %s for reading";
return false;
}
} else {
*error_msg = "File %s does not exist";
return false;
}
CHECK(file.get() != nullptr);
ImageHeader hdr;
if (sizeof(hdr) != file->Read(reinterpret_cast<char*>(&hdr), sizeof(hdr), 0)) {
*error_msg = "Failed to read file %s";
return false;
}
if (!hdr.IsValid()) {
*error_msg = "%s does not contain a valid image header.";
return false;
}
*delta = hdr.GetPatchDelta();
return true;
}
static File* CreateOrOpen(const char* name, bool* created) {
if (OS::FileExists(name)) {
*created = false;
return OS::OpenFileReadWrite(name);
} else {
*created = true;
std::unique_ptr<File> f(OS::CreateEmptyFile(name));
if (f.get() != nullptr) {
if (fchmod(f->Fd(), 0644) != 0) {
PLOG(ERROR) << "Unable to make " << name << " world readable";
unlink(name);
return nullptr;
}
}
return f.release();
}
}
// Either try to close the file (close=true), or erase it.
static bool FinishFile(File* file, bool close) {
if (close) {
if (file->FlushCloseOrErase() != 0) {
PLOG(ERROR) << "Failed to flush and close file.";
return false;
}
return true;
} else {
file->Erase();
return false;
}
}
static int patchoat(int argc, char **argv) {
InitLogging(argv);
MemMap::Init();
const bool debug = kIsDebugBuild;
orig_argc = argc;
orig_argv = argv;
TimingLogger timings("patcher", false, false);
InitLogging(argv);
// Skip over the command name.
argv++;
argc--;
if (argc == 0) {
Usage("No arguments specified");
}
timings.StartTiming("Patchoat");
// cmd line args
bool isa_set = false;
InstructionSet isa = kNone;
std::string input_oat_filename;
std::string input_oat_location;
int input_oat_fd = -1;
bool have_input_oat = false;
std::string input_image_location;
std::string output_oat_filename;
int output_oat_fd = -1;
bool have_output_oat = false;
std::string output_image_filename;
int output_image_fd = -1;
bool have_output_image = false;
uintptr_t base_offset = 0;
bool base_offset_set = false;
uintptr_t orig_base_offset = 0;
bool orig_base_offset_set = false;
off_t base_delta = 0;
bool base_delta_set = false;
std::string patched_image_filename;
std::string patched_image_location;
bool dump_timings = kIsDebugBuild;
bool lock_output = true;
for (int i = 0; i < argc; i++) {
const StringPiece option(argv[i]);
const bool log_options = false;
if (log_options) {
LOG(INFO) << "patchoat: option[" << i << "]=" << argv[i];
}
if (option.starts_with("--instruction-set=")) {
isa_set = true;
const char* isa_str = option.substr(strlen("--instruction-set=")).data();
isa = GetInstructionSetFromString(isa_str);
if (isa == kNone) {
Usage("Unknown or invalid instruction set %s", isa_str);
}
} else if (option.starts_with("--input-oat-location=")) {
if (have_input_oat) {
Usage("Only one of --input-oat-file, --input-oat-location and --input-oat-fd may be used.");
}
have_input_oat = true;
input_oat_location = option.substr(strlen("--input-oat-location=")).data();
} else if (option.starts_with("--input-oat-file=")) {
if (have_input_oat) {
Usage("Only one of --input-oat-file, --input-oat-location and --input-oat-fd may be used.");
}
have_input_oat = true;
input_oat_filename = option.substr(strlen("--input-oat-file=")).data();
} else if (option.starts_with("--input-oat-fd=")) {
if (have_input_oat) {
Usage("Only one of --input-oat-file, --input-oat-location and --input-oat-fd may be used.");
}
have_input_oat = true;
const char* oat_fd_str = option.substr(strlen("--input-oat-fd=")).data();
if (!ParseInt(oat_fd_str, &input_oat_fd)) {
Usage("Failed to parse --input-oat-fd argument '%s' as an integer", oat_fd_str);
}
if (input_oat_fd < 0) {
Usage("--input-oat-fd pass a negative value %d", input_oat_fd);
}
} else if (option.starts_with("--input-image-location=")) {
input_image_location = option.substr(strlen("--input-image-location=")).data();
} else if (option.starts_with("--output-oat-file=")) {
if (have_output_oat) {
Usage("Only one of --output-oat-file, and --output-oat-fd may be used.");
}
have_output_oat = true;
output_oat_filename = option.substr(strlen("--output-oat-file=")).data();
} else if (option.starts_with("--output-oat-fd=")) {
if (have_output_oat) {
Usage("Only one of --output-oat-file, --output-oat-fd may be used.");
}
have_output_oat = true;
const char* oat_fd_str = option.substr(strlen("--output-oat-fd=")).data();
if (!ParseInt(oat_fd_str, &output_oat_fd)) {
Usage("Failed to parse --output-oat-fd argument '%s' as an integer", oat_fd_str);
}
if (output_oat_fd < 0) {
Usage("--output-oat-fd pass a negative value %d", output_oat_fd);
}
} else if (option.starts_with("--output-image-file=")) {
if (have_output_image) {
Usage("Only one of --output-image-file, and --output-image-fd may be used.");
}
have_output_image = true;
output_image_filename = option.substr(strlen("--output-image-file=")).data();
} else if (option.starts_with("--output-image-fd=")) {
if (have_output_image) {
Usage("Only one of --output-image-file, and --output-image-fd may be used.");
}
have_output_image = true;
const char* image_fd_str = option.substr(strlen("--output-image-fd=")).data();
if (!ParseInt(image_fd_str, &output_image_fd)) {
Usage("Failed to parse --output-image-fd argument '%s' as an integer", image_fd_str);
}
if (output_image_fd < 0) {
Usage("--output-image-fd pass a negative value %d", output_image_fd);
}
} else if (option.starts_with("--orig-base-offset=")) {
const char* orig_base_offset_str = option.substr(strlen("--orig-base-offset=")).data();
orig_base_offset_set = true;
if (!ParseUint(orig_base_offset_str, &orig_base_offset)) {
Usage("Failed to parse --orig-base-offset argument '%s' as an uintptr_t",
orig_base_offset_str);
}
} else if (option.starts_with("--base-offset=")) {
const char* base_offset_str = option.substr(strlen("--base-offset=")).data();
base_offset_set = true;
if (!ParseUint(base_offset_str, &base_offset)) {
Usage("Failed to parse --base-offset argument '%s' as an uintptr_t", base_offset_str);
}
} else if (option.starts_with("--base-offset-delta=")) {
const char* base_delta_str = option.substr(strlen("--base-offset-delta=")).data();
base_delta_set = true;
if (!ParseInt(base_delta_str, &base_delta)) {
Usage("Failed to parse --base-offset-delta argument '%s' as an off_t", base_delta_str);
}
} else if (option.starts_with("--patched-image-location=")) {
patched_image_location = option.substr(strlen("--patched-image-location=")).data();
} else if (option.starts_with("--patched-image-file=")) {
patched_image_filename = option.substr(strlen("--patched-image-file=")).data();
} else if (option == "--lock-output") {
lock_output = true;
} else if (option == "--no-lock-output") {
lock_output = false;
} else if (option == "--dump-timings") {
dump_timings = true;
} else if (option == "--no-dump-timings") {
dump_timings = false;
} else {
Usage("Unknown argument %s", option.data());
}
}
{
// Only 1 of these may be set.
uint32_t cnt = 0;
cnt += (base_delta_set) ? 1 : 0;
cnt += (base_offset_set && orig_base_offset_set) ? 1 : 0;
cnt += (!patched_image_filename.empty()) ? 1 : 0;
cnt += (!patched_image_location.empty()) ? 1 : 0;
if (cnt > 1) {
Usage("Only one of --base-offset/--orig-base-offset, --base-offset-delta, "
"--patched-image-filename or --patched-image-location may be used.");
} else if (cnt == 0) {
Usage("Must specify --base-offset-delta, --base-offset and --orig-base-offset, "
"--patched-image-location or --patched-image-file");
}
}
if (have_input_oat != have_output_oat) {
Usage("Either both input and output oat must be supplied or niether must be.");
}
if ((!input_image_location.empty()) != have_output_image) {
Usage("Either both input and output image must be supplied or niether must be.");
}
// We know we have both the input and output so rename for clarity.
bool have_image_files = have_output_image;
bool have_oat_files = have_output_oat;
if (!have_oat_files && !have_image_files) {
Usage("Must be patching either an oat or an image file or both.");
}
if (!have_oat_files && !isa_set) {
Usage("Must include ISA if patching an image file without an oat file.");
}
if (!input_oat_location.empty()) {
if (!isa_set) {
Usage("specifying a location requires specifying an instruction set");
}
if (!LocationToFilename(input_oat_location, isa, &input_oat_filename)) {
Usage("Unable to find filename for input oat location %s", input_oat_location.c_str());
}
if (debug) {
LOG(INFO) << "Using input-oat-file " << input_oat_filename;
}
}
if (!patched_image_location.empty()) {
if (!isa_set) {
Usage("specifying a location requires specifying an instruction set");
}
std::string system_filename;
bool has_system = false;
std::string cache_filename;
bool has_cache = false;
bool has_android_data_unused = false;
bool is_global_cache = false;
if (!gc::space::ImageSpace::FindImageFilename(patched_image_location.c_str(), isa,
&system_filename, &has_system, &cache_filename,
&has_android_data_unused, &has_cache,
&is_global_cache)) {
Usage("Unable to determine image file for location %s", patched_image_location.c_str());
}
if (has_cache) {
patched_image_filename = cache_filename;
} else if (has_system) {
LOG(WARNING) << "Only image file found was in /system for image location "
<< patched_image_location;
patched_image_filename = system_filename;
} else {
Usage("Unable to determine image file for location %s", patched_image_location.c_str());
}
if (debug) {
LOG(INFO) << "Using patched-image-file " << patched_image_filename;
}
}
if (!base_delta_set) {
if (orig_base_offset_set && base_offset_set) {
base_delta_set = true;
base_delta = base_offset - orig_base_offset;
} else if (!patched_image_filename.empty()) {
base_delta_set = true;
std::string error_msg;
if (!ReadBaseDelta(patched_image_filename.c_str(), &base_delta, &error_msg)) {
Usage(error_msg.c_str(), patched_image_filename.c_str());
}
} else {
if (base_offset_set) {
Usage("Unable to determine original base offset.");
} else {
Usage("Must supply a desired new offset or delta.");
}
}
}
if (!IsAligned<kPageSize>(base_delta)) {
Usage("Base offset/delta must be alligned to a pagesize (0x%08x) boundary.", kPageSize);
}
// Do we need to cleanup output files if we fail?
bool new_image_out = false;
bool new_oat_out = false;
std::unique_ptr<File> input_oat;
std::unique_ptr<File> output_oat;
std::unique_ptr<File> output_image;
if (have_image_files) {
CHECK(!input_image_location.empty());
if (output_image_fd != -1) {
if (output_image_filename.empty()) {
output_image_filename = "output-image-file";
}
output_image.reset(new File(output_image_fd, output_image_filename, true));
} else {
CHECK(!output_image_filename.empty());
output_image.reset(CreateOrOpen(output_image_filename.c_str(), &new_image_out));
}
} else {
CHECK(output_image_filename.empty() && output_image_fd == -1 && input_image_location.empty());
}
if (have_oat_files) {
if (input_oat_fd != -1) {
if (input_oat_filename.empty()) {
input_oat_filename = "input-oat-file";
}
input_oat.reset(new File(input_oat_fd, input_oat_filename, false));
if (input_oat == nullptr) {
// Unlikely, but ensure exhaustive logging in non-0 exit code case
LOG(ERROR) << "Failed to open input oat file by its FD" << input_oat_fd;
}
} else {
CHECK(!input_oat_filename.empty());
input_oat.reset(OS::OpenFileForReading(input_oat_filename.c_str()));
if (input_oat == nullptr) {
int err = errno;
LOG(ERROR) << "Failed to open input oat file " << input_oat_filename
<< ": " << strerror(err) << "(" << err << ")";
}
}
if (output_oat_fd != -1) {
if (output_oat_filename.empty()) {
output_oat_filename = "output-oat-file";
}
output_oat.reset(new File(output_oat_fd, output_oat_filename, true));
if (output_oat == nullptr) {
// Unlikely, but ensure exhaustive logging in non-0 exit code case
LOG(ERROR) << "Failed to open output oat file by its FD" << output_oat_fd;
}
} else {
CHECK(!output_oat_filename.empty());
output_oat.reset(CreateOrOpen(output_oat_filename.c_str(), &new_oat_out));
if (output_oat == nullptr) {
int err = errno;
LOG(ERROR) << "Failed to open output oat file " << output_oat_filename
<< ": " << strerror(err) << "(" << err << ")";
}
}
}
// TODO: get rid of this.
auto cleanup = [&output_image_filename, &output_oat_filename,
&new_oat_out, &new_image_out, &timings, &dump_timings](bool success) {
timings.EndTiming();
if (!success) {
if (new_oat_out) {
CHECK(!output_oat_filename.empty());
unlink(output_oat_filename.c_str());
}
if (new_image_out) {
CHECK(!output_image_filename.empty());
unlink(output_image_filename.c_str());
}
}
if (dump_timings) {
LOG(INFO) << Dumpable<TimingLogger>(timings);
}
if (kIsDebugBuild) {
LOG(INFO) << "Cleaning up.. success? " << success;
}
};
if (have_oat_files && (input_oat.get() == nullptr || output_oat.get() == nullptr)) {
LOG(ERROR) << "Failed to open input/output oat files";
cleanup(false);
return EXIT_FAILURE;
} else if (have_image_files && output_image.get() == nullptr) {
LOG(ERROR) << "Failed to open output image file";
cleanup(false);
return EXIT_FAILURE;
}
if (debug) {
LOG(INFO) << "moving offset by " << base_delta
<< " (0x" << std::hex << base_delta << ") bytes or "
<< std::dec << (base_delta/kPageSize) << " pages.";
}
// TODO: is it going to be promatic to unlink a file that was flock-ed?
ScopedFlock output_oat_lock;
if (lock_output) {
std::string error_msg;
if (have_oat_files && !output_oat_lock.Init(output_oat.get(), &error_msg)) {
LOG(ERROR) << "Unable to lock output oat " << output_image->GetPath() << ": " << error_msg;
cleanup(false);
return EXIT_FAILURE;
}
}
bool ret;
if (have_image_files && have_oat_files) {
TimingLogger::ScopedTiming pt("patch image and oat", &timings);
ret = PatchOat::Patch(input_oat.get(), input_image_location, base_delta,
output_oat.get(), output_image.get(), isa, &timings,
output_oat_fd >= 0, // was it opened from FD?
new_oat_out);
// The order here doesn't matter. If the first one is successfully saved and the second one
// erased, ImageSpace will still detect a problem and not use the files.
ret = ret && FinishFile(output_image.get(), ret);
ret = ret && FinishFile(output_oat.get(), ret);
} else if (have_oat_files) {
TimingLogger::ScopedTiming pt("patch oat", &timings);
ret = PatchOat::Patch(input_oat.get(), base_delta, output_oat.get(), &timings,
output_oat_fd >= 0, // was it opened from FD?
new_oat_out);
ret = ret && FinishFile(output_oat.get(), ret);
} else if (have_image_files) {
TimingLogger::ScopedTiming pt("patch image", &timings);
ret = PatchOat::Patch(input_image_location, base_delta, output_image.get(), isa, &timings);
ret = ret && FinishFile(output_image.get(), ret);
} else {
CHECK(false);
ret = true;
}
if (kIsDebugBuild) {
LOG(INFO) << "Exiting with return ... " << ret;
}
cleanup(ret);
return (ret) ? EXIT_SUCCESS : EXIT_FAILURE;
}
} // namespace art
int main(int argc, char **argv) {
return art::patchoat(argc, argv);
}