/*
* Copyright (C) 2011 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 "oat_file.h"
#include <dlfcn.h>
#include <string.h>
#include <type_traits>
#include <unistd.h>
#include <cstdlib>
#ifndef __APPLE__
#include <link.h> // for dl_iterate_phdr.
#endif
#include <sstream>
// dlopen_ext support from bionic.
#ifdef __ANDROID__
#include "android/dlext.h"
#endif
#include "art_method-inl.h"
#include "base/bit_vector.h"
#include "base/stl_util.h"
#include "base/systrace.h"
#include "base/unix_file/fd_file.h"
#include "elf_file.h"
#include "elf_utils.h"
#include "oat.h"
#include "mem_map.h"
#include "mirror/class.h"
#include "mirror/object-inl.h"
#include "oat_file-inl.h"
#include "oat_file_manager.h"
#include "os.h"
#include "runtime.h"
#include "type_lookup_table.h"
#include "utils.h"
#include "utils/dex_cache_arrays_layout-inl.h"
namespace art {
// Whether OatFile::Open will try dlopen. Fallback is our own ELF loader.
static constexpr bool kUseDlopen = true;
// Whether OatFile::Open will try dlopen on the host. On the host we're not linking against
// bionic, so cannot take advantage of the support for changed semantics (loading the same soname
// multiple times). However, if/when we switch the above, we likely want to switch this, too,
// to get test coverage of the code paths.
static constexpr bool kUseDlopenOnHost = true;
// For debugging, Open will print DlOpen error message if set to true.
static constexpr bool kPrintDlOpenErrorMessage = false;
// Note for OatFileBase and descendents:
//
// These are used in OatFile::Open to try all our loaders.
//
// The process is simple:
//
// 1) Allocate an instance through the standard constructor (location, executable)
// 2) Load() to try to open the file.
// 3) ComputeFields() to populate the OatFile fields like begin_, using FindDynamicSymbolAddress.
// 4) PreSetup() for any steps that should be done before the final setup.
// 5) Setup() to complete the procedure.
class OatFileBase : public OatFile {
public:
virtual ~OatFileBase() {}
template <typename kOatFileBaseSubType>
static OatFileBase* OpenOatFile(const std::string& elf_filename,
const std::string& location,
uint8_t* requested_base,
uint8_t* oat_file_begin,
bool writable,
bool executable,
bool low_4gb,
const char* abs_dex_location,
std::string* error_msg);
protected:
OatFileBase(const std::string& filename, bool executable) : OatFile(filename, executable) {}
virtual const uint8_t* FindDynamicSymbolAddress(const std::string& symbol_name,
std::string* error_msg) const = 0;
virtual void PreLoad() = 0;
virtual bool Load(const std::string& elf_filename,
uint8_t* oat_file_begin,
bool writable,
bool executable,
bool low_4gb,
std::string* error_msg) = 0;
bool ComputeFields(uint8_t* requested_base,
const std::string& file_path,
std::string* error_msg);
virtual void PreSetup(const std::string& elf_filename) = 0;
bool Setup(const char* abs_dex_location, std::string* error_msg);
// Setters exposed for ElfOatFile.
void SetBegin(const uint8_t* begin) {
begin_ = begin;
}
void SetEnd(const uint8_t* end) {
end_ = end;
}
private:
DISALLOW_COPY_AND_ASSIGN(OatFileBase);
};
template <typename kOatFileBaseSubType>
OatFileBase* OatFileBase::OpenOatFile(const std::string& elf_filename,
const std::string& location,
uint8_t* requested_base,
uint8_t* oat_file_begin,
bool writable,
bool executable,
bool low_4gb,
const char* abs_dex_location,
std::string* error_msg) {
std::unique_ptr<OatFileBase> ret(new kOatFileBaseSubType(location, executable));
ret->PreLoad();
if (!ret->Load(elf_filename,
oat_file_begin,
writable,
executable,
low_4gb,
error_msg)) {
return nullptr;
}
if (!ret->ComputeFields(requested_base, elf_filename, error_msg)) {
return nullptr;
}
ret->PreSetup(elf_filename);
if (!ret->Setup(abs_dex_location, error_msg)) {
return nullptr;
}
return ret.release();
}
bool OatFileBase::ComputeFields(uint8_t* requested_base,
const std::string& file_path,
std::string* error_msg) {
std::string symbol_error_msg;
begin_ = FindDynamicSymbolAddress("oatdata", &symbol_error_msg);
if (begin_ == nullptr) {
*error_msg = StringPrintf("Failed to find oatdata symbol in '%s' %s",
file_path.c_str(),
symbol_error_msg.c_str());
return false;
}
if (requested_base != nullptr && begin_ != requested_base) {
// Host can fail this check. Do not dump there to avoid polluting the output.
if (kIsTargetBuild && (kIsDebugBuild || VLOG_IS_ON(oat))) {
PrintFileToLog("/proc/self/maps", LogSeverity::WARNING);
}
*error_msg = StringPrintf("Failed to find oatdata symbol at expected address: "
"oatdata=%p != expected=%p. See process maps in the log.",
begin_, requested_base);
return false;
}
end_ = FindDynamicSymbolAddress("oatlastword", &symbol_error_msg);
if (end_ == nullptr) {
*error_msg = StringPrintf("Failed to find oatlastword symbol in '%s' %s",
file_path.c_str(),
symbol_error_msg.c_str());
return false;
}
// Readjust to be non-inclusive upper bound.
end_ += sizeof(uint32_t);
bss_begin_ = const_cast<uint8_t*>(FindDynamicSymbolAddress("oatbss", &symbol_error_msg));
if (bss_begin_ == nullptr) {
// No .bss section.
bss_end_ = nullptr;
} else {
bss_end_ = const_cast<uint8_t*>(FindDynamicSymbolAddress("oatbsslastword", &symbol_error_msg));
if (bss_end_ == nullptr) {
*error_msg = StringPrintf("Failed to find oatbasslastword symbol in '%s'", file_path.c_str());
return false;
}
// Readjust to be non-inclusive upper bound.
bss_end_ += sizeof(uint32_t);
}
return true;
}
// Read an unaligned entry from the OatDexFile data in OatFile and advance the read
// position by the number of bytes read, i.e. sizeof(T).
// Return true on success, false if the read would go beyond the end of the OatFile.
template <typename T>
inline static bool ReadOatDexFileData(const OatFile& oat_file,
/*inout*/const uint8_t** oat,
/*out*/T* value) {
DCHECK(oat != nullptr);
DCHECK(value != nullptr);
DCHECK_LE(*oat, oat_file.End());
if (UNLIKELY(static_cast<size_t>(oat_file.End() - *oat) < sizeof(T))) {
return false;
}
static_assert(std::is_trivial<T>::value, "T must be a trivial type");
typedef __attribute__((__aligned__(1))) T unaligned_type;
*value = *reinterpret_cast<const unaligned_type*>(*oat);
*oat += sizeof(T);
return true;
}
bool OatFileBase::Setup(const char* abs_dex_location, std::string* error_msg) {
if (!GetOatHeader().IsValid()) {
std::string cause = GetOatHeader().GetValidationErrorMessage();
*error_msg = StringPrintf("Invalid oat header for '%s': %s",
GetLocation().c_str(),
cause.c_str());
return false;
}
const uint8_t* oat = Begin();
oat += sizeof(OatHeader);
if (oat > End()) {
*error_msg = StringPrintf("In oat file '%s' found truncated OatHeader", GetLocation().c_str());
return false;
}
oat += GetOatHeader().GetKeyValueStoreSize();
if (oat > End()) {
*error_msg = StringPrintf("In oat file '%s' found truncated variable-size data: "
"%p + %zu + %u <= %p",
GetLocation().c_str(),
Begin(),
sizeof(OatHeader),
GetOatHeader().GetKeyValueStoreSize(),
End());
return false;
}
size_t pointer_size = GetInstructionSetPointerSize(GetOatHeader().GetInstructionSet());
uint8_t* dex_cache_arrays = bss_begin_;
uint32_t dex_file_count = GetOatHeader().GetDexFileCount();
oat_dex_files_storage_.reserve(dex_file_count);
for (size_t i = 0; i < dex_file_count; i++) {
uint32_t dex_file_location_size;
if (UNLIKELY(!ReadOatDexFileData(*this, &oat, &dex_file_location_size))) {
*error_msg = StringPrintf("In oat file '%s' found OatDexFile #%zu truncated after dex file "
"location size",
GetLocation().c_str(),
i);
return false;
}
if (UNLIKELY(dex_file_location_size == 0U)) {
*error_msg = StringPrintf("In oat file '%s' found OatDexFile #%zu with empty location name",
GetLocation().c_str(),
i);
return false;
}
if (UNLIKELY(static_cast<size_t>(End() - oat) < dex_file_location_size)) {
*error_msg = StringPrintf("In oat file '%s' found OatDexFile #%zu with truncated dex file "
"location",
GetLocation().c_str(),
i);
return false;
}
const char* dex_file_location_data = reinterpret_cast<const char*>(oat);
oat += dex_file_location_size;
std::string dex_file_location = ResolveRelativeEncodedDexLocation(
abs_dex_location,
std::string(dex_file_location_data, dex_file_location_size));
uint32_t dex_file_checksum;
if (UNLIKELY(!ReadOatDexFileData(*this, &oat, &dex_file_checksum))) {
*error_msg = StringPrintf("In oat file '%s' found OatDexFile #%zu for '%s' truncated after "
"dex file checksum",
GetLocation().c_str(),
i,
dex_file_location.c_str());
return false;
}
uint32_t dex_file_offset;
if (UNLIKELY(!ReadOatDexFileData(*this, &oat, &dex_file_offset))) {
*error_msg = StringPrintf("In oat file '%s' found OatDexFile #%zu for '%s' truncated "
"after dex file offsets",
GetLocation().c_str(),
i,
dex_file_location.c_str());
return false;
}
if (UNLIKELY(dex_file_offset == 0U)) {
*error_msg = StringPrintf("In oat file '%s' found OatDexFile #%zu for '%s' with zero dex "
"file offset",
GetLocation().c_str(),
i,
dex_file_location.c_str());
return false;
}
if (UNLIKELY(dex_file_offset > Size())) {
*error_msg = StringPrintf("In oat file '%s' found OatDexFile #%zu for '%s' with dex file "
"offset %u > %zu",
GetLocation().c_str(),
i,
dex_file_location.c_str(),
dex_file_offset,
Size());
return false;
}
if (UNLIKELY(Size() - dex_file_offset < sizeof(DexFile::Header))) {
*error_msg = StringPrintf("In oat file '%s' found OatDexFile #%zu for '%s' with dex file "
"offset %u of %zu but the size of dex file header is %zu",
GetLocation().c_str(),
i,
dex_file_location.c_str(),
dex_file_offset,
Size(),
sizeof(DexFile::Header));
return false;
}
const uint8_t* dex_file_pointer = Begin() + dex_file_offset;
if (UNLIKELY(!DexFile::IsMagicValid(dex_file_pointer))) {
*error_msg = StringPrintf("In oat file '%s' found OatDexFile #%zu for '%s' with invalid "
"dex file magic '%s'",
GetLocation().c_str(),
i,
dex_file_location.c_str(),
dex_file_pointer);
return false;
}
if (UNLIKELY(!DexFile::IsVersionValid(dex_file_pointer))) {
*error_msg = StringPrintf("In oat file '%s' found OatDexFile #%zu for '%s' with invalid "
"dex file version '%s'",
GetLocation().c_str(),
i,
dex_file_location.c_str(),
dex_file_pointer);
return false;
}
const DexFile::Header* header = reinterpret_cast<const DexFile::Header*>(dex_file_pointer);
if (Size() - dex_file_offset < header->file_size_) {
*error_msg = StringPrintf("In oat file '%s' found OatDexFile #%zu for '%s' with dex file "
"offset %u and size %u truncated at %zu",
GetLocation().c_str(),
i,
dex_file_location.c_str(),
dex_file_offset,
header->file_size_,
Size());
return false;
}
uint32_t class_offsets_offset;
if (UNLIKELY(!ReadOatDexFileData(*this, &oat, &class_offsets_offset))) {
*error_msg = StringPrintf("In oat file '%s' found OatDexFile #%zu for '%s' truncated "
"after class offsets offset",
GetLocation().c_str(),
i,
dex_file_location.c_str());
return false;
}
if (UNLIKELY(class_offsets_offset > Size()) ||
UNLIKELY((Size() - class_offsets_offset) / sizeof(uint32_t) < header->class_defs_size_)) {
*error_msg = StringPrintf("In oat file '%s' found OatDexFile #%zu for '%s' with truncated "
"class offsets, offset %u of %zu, class defs %u",
GetLocation().c_str(),
i,
dex_file_location.c_str(),
class_offsets_offset,
Size(),
header->class_defs_size_);
return false;
}
if (UNLIKELY(!IsAligned<alignof(uint32_t)>(class_offsets_offset))) {
*error_msg = StringPrintf("In oat file '%s' found OatDexFile #%zu for '%s' with unaligned "
"class offsets, offset %u",
GetLocation().c_str(),
i,
dex_file_location.c_str(),
class_offsets_offset);
return false;
}
const uint32_t* class_offsets_pointer =
reinterpret_cast<const uint32_t*>(Begin() + class_offsets_offset);
uint32_t lookup_table_offset;
if (UNLIKELY(!ReadOatDexFileData(*this, &oat, &lookup_table_offset))) {
*error_msg = StringPrintf("In oat file '%s' found OatDexFile #%zd for '%s' truncated "
"after lookup table offset",
GetLocation().c_str(),
i,
dex_file_location.c_str());
return false;
}
const uint8_t* lookup_table_data = lookup_table_offset != 0u
? Begin() + lookup_table_offset
: nullptr;
if (lookup_table_offset != 0u &&
(UNLIKELY(lookup_table_offset > Size()) ||
UNLIKELY(Size() - lookup_table_offset <
TypeLookupTable::RawDataLength(header->class_defs_size_)))) {
*error_msg = StringPrintf("In oat file '%s' found OatDexFile #%zu for '%s' with truncated "
"type lookup table, offset %u of %zu, class defs %u",
GetLocation().c_str(),
i,
dex_file_location.c_str(),
lookup_table_offset,
Size(),
header->class_defs_size_);
return false;
}
uint8_t* current_dex_cache_arrays = nullptr;
if (dex_cache_arrays != nullptr) {
DexCacheArraysLayout layout(pointer_size, *header);
if (layout.Size() != 0u) {
if (static_cast<size_t>(bss_end_ - dex_cache_arrays) < layout.Size()) {
*error_msg = StringPrintf("In oat file '%s' found OatDexFile #%zu for '%s' with "
"truncated dex cache arrays, %zu < %zu.",
GetLocation().c_str(),
i,
dex_file_location.c_str(),
static_cast<size_t>(bss_end_ - dex_cache_arrays),
layout.Size());
return false;
}
current_dex_cache_arrays = dex_cache_arrays;
dex_cache_arrays += layout.Size();
}
}
std::string canonical_location = DexFile::GetDexCanonicalLocation(dex_file_location.c_str());
// Create the OatDexFile and add it to the owning container.
OatDexFile* oat_dex_file = new OatDexFile(this,
dex_file_location,
canonical_location,
dex_file_checksum,
dex_file_pointer,
lookup_table_data,
class_offsets_pointer,
current_dex_cache_arrays);
oat_dex_files_storage_.push_back(oat_dex_file);
// Add the location and canonical location (if different) to the oat_dex_files_ table.
StringPiece key(oat_dex_file->GetDexFileLocation());
oat_dex_files_.Put(key, oat_dex_file);
if (canonical_location != dex_file_location) {
StringPiece canonical_key(oat_dex_file->GetCanonicalDexFileLocation());
oat_dex_files_.Put(canonical_key, oat_dex_file);
}
}
if (dex_cache_arrays != bss_end_) {
// We expect the bss section to be either empty (dex_cache_arrays and bss_end_
// both null) or contain just the dex cache arrays and nothing else.
*error_msg = StringPrintf("In oat file '%s' found unexpected bss size bigger by %zu bytes.",
GetLocation().c_str(),
static_cast<size_t>(bss_end_ - dex_cache_arrays));
return false;
}
return true;
}
////////////////////////
// OatFile via dlopen //
////////////////////////
class DlOpenOatFile FINAL : public OatFileBase {
public:
DlOpenOatFile(const std::string& filename, bool executable)
: OatFileBase(filename, executable),
dlopen_handle_(nullptr),
shared_objects_before_(0) {
}
~DlOpenOatFile() {
if (dlopen_handle_ != nullptr) {
if (!kIsTargetBuild) {
MutexLock mu(Thread::Current(), *Locks::host_dlopen_handles_lock_);
host_dlopen_handles_.erase(dlopen_handle_);
dlclose(dlopen_handle_);
} else {
dlclose(dlopen_handle_);
}
}
}
protected:
const uint8_t* FindDynamicSymbolAddress(const std::string& symbol_name,
std::string* error_msg) const OVERRIDE {
const uint8_t* ptr =
reinterpret_cast<const uint8_t*>(dlsym(dlopen_handle_, symbol_name.c_str()));
if (ptr == nullptr) {
*error_msg = dlerror();
}
return ptr;
}
void PreLoad() OVERRIDE;
bool Load(const std::string& elf_filename,
uint8_t* oat_file_begin,
bool writable,
bool executable,
bool low_4gb,
std::string* error_msg) OVERRIDE;
// Ask the linker where it mmaped the file and notify our mmap wrapper of the regions.
void PreSetup(const std::string& elf_filename) OVERRIDE;
private:
bool Dlopen(const std::string& elf_filename,
uint8_t* oat_file_begin,
std::string* error_msg);
// On the host, if the same library is loaded again with dlopen the same
// file handle is returned. This differs from the behavior of dlopen on the
// target, where dlopen reloads the library at a different address every
// time you load it. The runtime relies on the target behavior to ensure
// each instance of the loaded library has a unique dex cache. To avoid
// problems, we fall back to our own linker in the case when the same
// library is opened multiple times on host. dlopen_handles_ is used to
// detect that case.
// Guarded by host_dlopen_handles_lock_;
static std::unordered_set<void*> host_dlopen_handles_;
// dlopen handle during runtime.
void* dlopen_handle_; // TODO: Unique_ptr with custom deleter.
// Dummy memory map objects corresponding to the regions mapped by dlopen.
std::vector<std::unique_ptr<MemMap>> dlopen_mmaps_;
// The number of shared objects the linker told us about before loading. Used to
// (optimistically) optimize the PreSetup stage (see comment there).
size_t shared_objects_before_;
DISALLOW_COPY_AND_ASSIGN(DlOpenOatFile);
};
std::unordered_set<void*> DlOpenOatFile::host_dlopen_handles_;
void DlOpenOatFile::PreLoad() {
#ifdef __APPLE__
UNUSED(shared_objects_before_);
LOG(FATAL) << "Should not reach here.";
UNREACHABLE();
#else
// Count the entries in dl_iterate_phdr we get at this point in time.
struct dl_iterate_context {
static int callback(struct dl_phdr_info *info ATTRIBUTE_UNUSED,
size_t size ATTRIBUTE_UNUSED,
void *data) {
reinterpret_cast<dl_iterate_context*>(data)->count++;
return 0; // Continue iteration.
}
size_t count = 0;
} context;
dl_iterate_phdr(dl_iterate_context::callback, &context);
shared_objects_before_ = context.count;
#endif
}
bool DlOpenOatFile::Load(const std::string& elf_filename,
uint8_t* oat_file_begin,
bool writable,
bool executable,
bool low_4gb,
std::string* error_msg) {
// Use dlopen only when flagged to do so, and when it's OK to load things executable.
// TODO: Also try when not executable? The issue here could be re-mapping as writable (as
// !executable is a sign that we may want to patch), which may not be allowed for
// various reasons.
if (!kUseDlopen) {
*error_msg = "DlOpen is disabled.";
return false;
}
if (low_4gb) {
*error_msg = "DlOpen does not support low 4gb loading.";
return false;
}
if (writable) {
*error_msg = "DlOpen does not support writable loading.";
return false;
}
if (!executable) {
*error_msg = "DlOpen does not support non-executable loading.";
return false;
}
// dlopen always returns the same library if it is already opened on the host. For this reason
// we only use dlopen if we are the target or we do not already have the dex file opened. Having
// the same library loaded multiple times at different addresses is required for class unloading
// and for having dex caches arrays in the .bss section.
if (!kIsTargetBuild) {
if (!kUseDlopenOnHost) {
*error_msg = "DlOpen disabled for host.";
return false;
}
}
bool success = Dlopen(elf_filename, oat_file_begin, error_msg);
DCHECK(dlopen_handle_ != nullptr || !success);
return success;
}
bool DlOpenOatFile::Dlopen(const std::string& elf_filename,
uint8_t* oat_file_begin,
std::string* error_msg) {
#ifdef __APPLE__
// The dl_iterate_phdr syscall is missing. There is similar API on OSX,
// but let's fallback to the custom loading code for the time being.
UNUSED(elf_filename, oat_file_begin);
*error_msg = "Dlopen unsupported on Mac.";
return false;
#else
{
UniqueCPtr<char> absolute_path(realpath(elf_filename.c_str(), nullptr));
if (absolute_path == nullptr) {
*error_msg = StringPrintf("Failed to find absolute path for '%s'", elf_filename.c_str());
return false;
}
#ifdef __ANDROID__
android_dlextinfo extinfo;
extinfo.flags = ANDROID_DLEXT_FORCE_LOAD | // Force-load, don't reuse handle
// (open oat files multiple
// times).
ANDROID_DLEXT_FORCE_FIXED_VADDR; // Take a non-zero vaddr as absolute
// (non-pic boot image).
if (oat_file_begin != nullptr) { //
extinfo.flags |= ANDROID_DLEXT_LOAD_AT_FIXED_ADDRESS; // Use the requested addr if
extinfo.reserved_addr = oat_file_begin; // vaddr = 0.
} // (pic boot image).
dlopen_handle_ = android_dlopen_ext(absolute_path.get(), RTLD_NOW, &extinfo);
#else
UNUSED(oat_file_begin);
static_assert(!kIsTargetBuild, "host_dlopen_handles_ will leak handles");
MutexLock mu(Thread::Current(), *Locks::host_dlopen_handles_lock_);
dlopen_handle_ = dlopen(absolute_path.get(), RTLD_NOW);
if (dlopen_handle_ != nullptr) {
if (!host_dlopen_handles_.insert(dlopen_handle_).second) {
dlclose(dlopen_handle_);
dlopen_handle_ = nullptr;
*error_msg = StringPrintf("host dlopen re-opened '%s'", elf_filename.c_str());
return false;
}
}
#endif
}
if (dlopen_handle_ == nullptr) {
*error_msg = StringPrintf("Failed to dlopen '%s': %s", elf_filename.c_str(), dlerror());
return false;
}
return true;
#endif
}
void DlOpenOatFile::PreSetup(const std::string& elf_filename) {
#ifdef __APPLE__
UNUSED(elf_filename);
LOG(FATAL) << "Should not reach here.";
UNREACHABLE();
#else
struct dl_iterate_context {
static int callback(struct dl_phdr_info *info, size_t /* size */, void *data) {
auto* context = reinterpret_cast<dl_iterate_context*>(data);
context->shared_objects_seen++;
if (context->shared_objects_seen < context->shared_objects_before) {
// We haven't been called yet for anything we haven't seen before. Just continue.
// Note: this is aggressively optimistic. If another thread was unloading a library,
// we may miss out here. However, this does not happen often in practice.
return 0;
}
// See whether this callback corresponds to the file which we have just loaded.
bool contains_begin = false;
for (int i = 0; i < info->dlpi_phnum; i++) {
if (info->dlpi_phdr[i].p_type == PT_LOAD) {
uint8_t* vaddr = reinterpret_cast<uint8_t*>(info->dlpi_addr +
info->dlpi_phdr[i].p_vaddr);
size_t memsz = info->dlpi_phdr[i].p_memsz;
if (vaddr <= context->begin_ && context->begin_ < vaddr + memsz) {
contains_begin = true;
break;
}
}
}
// Add dummy mmaps for this file.
if (contains_begin) {
for (int i = 0; i < info->dlpi_phnum; i++) {
if (info->dlpi_phdr[i].p_type == PT_LOAD) {
uint8_t* vaddr = reinterpret_cast<uint8_t*>(info->dlpi_addr +
info->dlpi_phdr[i].p_vaddr);
size_t memsz = info->dlpi_phdr[i].p_memsz;
MemMap* mmap = MemMap::MapDummy(info->dlpi_name, vaddr, memsz);
context->dlopen_mmaps_->push_back(std::unique_ptr<MemMap>(mmap));
}
}
return 1; // Stop iteration and return 1 from dl_iterate_phdr.
}
return 0; // Continue iteration and return 0 from dl_iterate_phdr when finished.
}
const uint8_t* const begin_;
std::vector<std::unique_ptr<MemMap>>* const dlopen_mmaps_;
const size_t shared_objects_before;
size_t shared_objects_seen;
};
dl_iterate_context context = { Begin(), &dlopen_mmaps_, shared_objects_before_, 0};
if (dl_iterate_phdr(dl_iterate_context::callback, &context) == 0) {
// Hm. Maybe our optimization went wrong. Try another time with shared_objects_before == 0
// before giving up. This should be unusual.
VLOG(oat) << "Need a second run in PreSetup, didn't find with shared_objects_before="
<< shared_objects_before_;
dl_iterate_context context0 = { Begin(), &dlopen_mmaps_, 0, 0};
if (dl_iterate_phdr(dl_iterate_context::callback, &context0) == 0) {
// OK, give up and print an error.
PrintFileToLog("/proc/self/maps", LogSeverity::WARNING);
LOG(ERROR) << "File " << elf_filename << " loaded with dlopen but cannot find its mmaps.";
}
}
#endif
}
////////////////////////////////////////////////
// OatFile via our own ElfFile implementation //
////////////////////////////////////////////////
class ElfOatFile FINAL : public OatFileBase {
public:
ElfOatFile(const std::string& filename, bool executable) : OatFileBase(filename, executable) {}
static ElfOatFile* OpenElfFile(File* file,
const std::string& location,
uint8_t* requested_base,
uint8_t* oat_file_begin, // Override base if not null
bool writable,
bool executable,
bool low_4gb,
const char* abs_dex_location,
std::string* error_msg);
bool InitializeFromElfFile(ElfFile* elf_file,
const char* abs_dex_location,
std::string* error_msg);
protected:
const uint8_t* FindDynamicSymbolAddress(const std::string& symbol_name,
std::string* error_msg) const OVERRIDE {
const uint8_t* ptr = elf_file_->FindDynamicSymbolAddress(symbol_name);
if (ptr == nullptr) {
*error_msg = "(Internal implementation could not find symbol)";
}
return ptr;
}
void PreLoad() OVERRIDE {
}
bool Load(const std::string& elf_filename,
uint8_t* oat_file_begin, // Override where the file is loaded to if not null
bool writable,
bool executable,
bool low_4gb,
std::string* error_msg) OVERRIDE;
void PreSetup(const std::string& elf_filename ATTRIBUTE_UNUSED) OVERRIDE {
}
private:
bool ElfFileOpen(File* file,
uint8_t* oat_file_begin, // Override where the file is loaded to if not null
bool writable,
bool executable,
bool low_4gb,
std::string* error_msg);
private:
// Backing memory map for oat file during cross compilation.
std::unique_ptr<ElfFile> elf_file_;
DISALLOW_COPY_AND_ASSIGN(ElfOatFile);
};
ElfOatFile* ElfOatFile::OpenElfFile(File* file,
const std::string& location,
uint8_t* requested_base,
uint8_t* oat_file_begin, // Override base if not null
bool writable,
bool executable,
bool low_4gb,
const char* abs_dex_location,
std::string* error_msg) {
ScopedTrace trace("Open elf file " + location);
std::unique_ptr<ElfOatFile> oat_file(new ElfOatFile(location, executable));
bool success = oat_file->ElfFileOpen(file,
oat_file_begin,
writable,
low_4gb,
executable,
error_msg);
if (!success) {
CHECK(!error_msg->empty());
return nullptr;
}
// Complete the setup.
if (!oat_file->ComputeFields(requested_base, file->GetPath(), error_msg)) {
return nullptr;
}
if (!oat_file->Setup(abs_dex_location, error_msg)) {
return nullptr;
}
return oat_file.release();
}
bool ElfOatFile::InitializeFromElfFile(ElfFile* elf_file,
const char* abs_dex_location,
std::string* error_msg) {
ScopedTrace trace(__PRETTY_FUNCTION__);
if (IsExecutable()) {
*error_msg = "Cannot initialize from elf file in executable mode.";
return false;
}
elf_file_.reset(elf_file);
uint64_t offset, size;
bool has_section = elf_file->GetSectionOffsetAndSize(".rodata", &offset, &size);
CHECK(has_section);
SetBegin(elf_file->Begin() + offset);
SetEnd(elf_file->Begin() + size + offset);
// Ignore the optional .bss section when opening non-executable.
return Setup(abs_dex_location, error_msg);
}
bool ElfOatFile::Load(const std::string& elf_filename,
uint8_t* oat_file_begin, // Override where the file is loaded to if not null
bool writable,
bool executable,
bool low_4gb,
std::string* error_msg) {
ScopedTrace trace(__PRETTY_FUNCTION__);
std::unique_ptr<File> file(OS::OpenFileForReading(elf_filename.c_str()));
if (file == nullptr) {
*error_msg = StringPrintf("Failed to open oat filename for reading: %s", strerror(errno));
return false;
}
return ElfOatFile::ElfFileOpen(file.get(),
oat_file_begin,
writable,
executable,
low_4gb,
error_msg);
}
bool ElfOatFile::ElfFileOpen(File* file,
uint8_t* oat_file_begin,
bool writable,
bool executable,
bool low_4gb,
std::string* error_msg) {
ScopedTrace trace(__PRETTY_FUNCTION__);
// TODO: rename requested_base to oat_data_begin
elf_file_.reset(ElfFile::Open(file,
writable,
/*program_header_only*/true,
low_4gb,
error_msg,
oat_file_begin));
if (elf_file_ == nullptr) {
DCHECK(!error_msg->empty());
return false;
}
bool loaded = elf_file_->Load(executable, low_4gb, error_msg);
DCHECK(loaded || !error_msg->empty());
return loaded;
}
//////////////////////////
// General OatFile code //
//////////////////////////
std::string OatFile::ResolveRelativeEncodedDexLocation(
const char* abs_dex_location, const std::string& rel_dex_location) {
if (abs_dex_location != nullptr && rel_dex_location[0] != '/') {
// Strip :classes<N>.dex used for secondary multidex files.
std::string base = DexFile::GetBaseLocation(rel_dex_location);
std::string multidex_suffix = DexFile::GetMultiDexSuffix(rel_dex_location);
// Check if the base is a suffix of the provided abs_dex_location.
std::string target_suffix = "/" + base;
std::string abs_location(abs_dex_location);
if (abs_location.size() > target_suffix.size()) {
size_t pos = abs_location.size() - target_suffix.size();
if (abs_location.compare(pos, std::string::npos, target_suffix) == 0) {
return abs_location + multidex_suffix;
}
}
}
return rel_dex_location;
}
static void CheckLocation(const std::string& location) {
CHECK(!location.empty());
}
OatFile* OatFile::OpenWithElfFile(ElfFile* elf_file,
const std::string& location,
const char* abs_dex_location,
std::string* error_msg) {
std::unique_ptr<ElfOatFile> oat_file(new ElfOatFile(location, false /* executable */));
return oat_file->InitializeFromElfFile(elf_file, abs_dex_location, error_msg)
? oat_file.release()
: nullptr;
}
OatFile* OatFile::Open(const std::string& filename,
const std::string& location,
uint8_t* requested_base,
uint8_t* oat_file_begin,
bool executable,
bool low_4gb,
const char* abs_dex_location,
std::string* error_msg) {
ScopedTrace trace("Open oat file " + location);
CHECK(!filename.empty()) << location;
CheckLocation(location);
// Check that the file even exists, fast-fail.
if (!OS::FileExists(filename.c_str())) {
*error_msg = StringPrintf("File %s does not exist.", filename.c_str());
return nullptr;
}
// Try dlopen first, as it is required for native debuggability. This will fail fast if dlopen is
// disabled.
OatFile* with_dlopen = OatFileBase::OpenOatFile<DlOpenOatFile>(filename,
location,
requested_base,
oat_file_begin,
false,
executable,
low_4gb,
abs_dex_location,
error_msg);
if (with_dlopen != nullptr) {
return with_dlopen;
}
if (kPrintDlOpenErrorMessage) {
LOG(ERROR) << "Failed to dlopen: " << filename << " with error " << *error_msg;
}
// If we aren't trying to execute, we just use our own ElfFile loader for a couple reasons:
//
// On target, dlopen may fail when compiling due to selinux restrictions on installd.
//
// We use our own ELF loader for Quick to deal with legacy apps that
// open a generated dex file by name, remove the file, then open
// another generated dex file with the same name. http://b/10614658
//
// On host, dlopen is expected to fail when cross compiling, so fall back to OpenElfFile.
//
//
// Another independent reason is the absolute placement of boot.oat. dlopen on the host usually
// does honor the virtual address encoded in the ELF file only for ET_EXEC files, not ET_DYN.
OatFile* with_internal = OatFileBase::OpenOatFile<ElfOatFile>(filename,
location,
requested_base,
oat_file_begin,
false,
executable,
low_4gb,
abs_dex_location,
error_msg);
return with_internal;
}
OatFile* OatFile::OpenWritable(File* file,
const std::string& location,
const char* abs_dex_location,
std::string* error_msg) {
CheckLocation(location);
return ElfOatFile::OpenElfFile(file,
location,
nullptr,
nullptr,
true,
false,
/*low_4gb*/false,
abs_dex_location,
error_msg);
}
OatFile* OatFile::OpenReadable(File* file,
const std::string& location,
const char* abs_dex_location,
std::string* error_msg) {
CheckLocation(location);
return ElfOatFile::OpenElfFile(file,
location,
nullptr,
nullptr,
false,
false,
/*low_4gb*/false,
abs_dex_location,
error_msg);
}
OatFile::OatFile(const std::string& location, bool is_executable)
: location_(location),
begin_(nullptr),
end_(nullptr),
bss_begin_(nullptr),
bss_end_(nullptr),
is_executable_(is_executable),
secondary_lookup_lock_("OatFile secondary lookup lock", kOatFileSecondaryLookupLock) {
CHECK(!location_.empty());
}
OatFile::~OatFile() {
STLDeleteElements(&oat_dex_files_storage_);
}
const OatHeader& OatFile::GetOatHeader() const {
return *reinterpret_cast<const OatHeader*>(Begin());
}
const uint8_t* OatFile::Begin() const {
CHECK(begin_ != nullptr);
return begin_;
}
const uint8_t* OatFile::End() const {
CHECK(end_ != nullptr);
return end_;
}
const uint8_t* OatFile::BssBegin() const {
return bss_begin_;
}
const uint8_t* OatFile::BssEnd() const {
return bss_end_;
}
const OatFile::OatDexFile* OatFile::GetOatDexFile(const char* dex_location,
const uint32_t* dex_location_checksum,
bool warn_if_not_found) const {
// NOTE: We assume here that the canonical location for a given dex_location never
// changes. If it does (i.e. some symlink used by the filename changes) we may return
// an incorrect OatDexFile. As long as we have a checksum to check, we shall return
// an identical file or fail; otherwise we may see some unpredictable failures.
// TODO: Additional analysis of usage patterns to see if this can be simplified
// without any performance loss, for example by not doing the first lock-free lookup.
const OatFile::OatDexFile* oat_dex_file = nullptr;
StringPiece key(dex_location);
// Try to find the key cheaply in the oat_dex_files_ map which holds dex locations
// directly mentioned in the oat file and doesn't require locking.
auto primary_it = oat_dex_files_.find(key);
if (primary_it != oat_dex_files_.end()) {
oat_dex_file = primary_it->second;
DCHECK(oat_dex_file != nullptr);
} else {
// This dex_location is not one of the dex locations directly mentioned in the
// oat file. The correct lookup is via the canonical location but first see in
// the secondary_oat_dex_files_ whether we've looked up this location before.
MutexLock mu(Thread::Current(), secondary_lookup_lock_);
auto secondary_lb = secondary_oat_dex_files_.lower_bound(key);
if (secondary_lb != secondary_oat_dex_files_.end() && key == secondary_lb->first) {
oat_dex_file = secondary_lb->second; // May be null.
} else {
// We haven't seen this dex_location before, we must check the canonical location.
std::string dex_canonical_location = DexFile::GetDexCanonicalLocation(dex_location);
if (dex_canonical_location != dex_location) {
StringPiece canonical_key(dex_canonical_location);
auto canonical_it = oat_dex_files_.find(canonical_key);
if (canonical_it != oat_dex_files_.end()) {
oat_dex_file = canonical_it->second;
} // else keep null.
} // else keep null.
// Copy the key to the string_cache_ and store the result in secondary map.
string_cache_.emplace_back(key.data(), key.length());
StringPiece key_copy(string_cache_.back());
secondary_oat_dex_files_.PutBefore(secondary_lb, key_copy, oat_dex_file);
}
}
if (oat_dex_file != nullptr &&
(dex_location_checksum == nullptr ||
oat_dex_file->GetDexFileLocationChecksum() == *dex_location_checksum)) {
return oat_dex_file;
}
if (warn_if_not_found) {
std::string dex_canonical_location = DexFile::GetDexCanonicalLocation(dex_location);
std::string checksum("<unspecified>");
if (dex_location_checksum != nullptr) {
checksum = StringPrintf("0x%08x", *dex_location_checksum);
}
LOG(WARNING) << "Failed to find OatDexFile for DexFile " << dex_location
<< " ( canonical path " << dex_canonical_location << ")"
<< " with checksum " << checksum << " in OatFile " << GetLocation();
if (kIsDebugBuild) {
for (const OatDexFile* odf : oat_dex_files_storage_) {
LOG(WARNING) << "OatFile " << GetLocation()
<< " contains OatDexFile " << odf->GetDexFileLocation()
<< " (canonical path " << odf->GetCanonicalDexFileLocation() << ")"
<< " with checksum 0x" << std::hex << odf->GetDexFileLocationChecksum();
}
}
}
return nullptr;
}
OatFile::OatDexFile::OatDexFile(const OatFile* oat_file,
const std::string& dex_file_location,
const std::string& canonical_dex_file_location,
uint32_t dex_file_location_checksum,
const uint8_t* dex_file_pointer,
const uint8_t* lookup_table_data,
const uint32_t* oat_class_offsets_pointer,
uint8_t* dex_cache_arrays)
: oat_file_(oat_file),
dex_file_location_(dex_file_location),
canonical_dex_file_location_(canonical_dex_file_location),
dex_file_location_checksum_(dex_file_location_checksum),
dex_file_pointer_(dex_file_pointer),
lookup_table_data_(lookup_table_data),
oat_class_offsets_pointer_(oat_class_offsets_pointer),
dex_cache_arrays_(dex_cache_arrays) {}
OatFile::OatDexFile::~OatDexFile() {}
size_t OatFile::OatDexFile::FileSize() const {
return reinterpret_cast<const DexFile::Header*>(dex_file_pointer_)->file_size_;
}
std::unique_ptr<const DexFile> OatFile::OatDexFile::OpenDexFile(std::string* error_msg) const {
ScopedTrace trace(__PRETTY_FUNCTION__);
return DexFile::Open(dex_file_pointer_,
FileSize(),
dex_file_location_,
dex_file_location_checksum_,
this,
false /* verify */,
error_msg);
}
uint32_t OatFile::OatDexFile::GetOatClassOffset(uint16_t class_def_index) const {
return oat_class_offsets_pointer_[class_def_index];
}
OatFile::OatClass OatFile::OatDexFile::GetOatClass(uint16_t class_def_index) const {
uint32_t oat_class_offset = GetOatClassOffset(class_def_index);
const uint8_t* oat_class_pointer = oat_file_->Begin() + oat_class_offset;
CHECK_LT(oat_class_pointer, oat_file_->End()) << oat_file_->GetLocation();
const uint8_t* status_pointer = oat_class_pointer;
CHECK_LT(status_pointer, oat_file_->End()) << oat_file_->GetLocation();
mirror::Class::Status status =
static_cast<mirror::Class::Status>(*reinterpret_cast<const int16_t*>(status_pointer));
CHECK_LT(status, mirror::Class::kStatusMax);
const uint8_t* type_pointer = status_pointer + sizeof(uint16_t);
CHECK_LT(type_pointer, oat_file_->End()) << oat_file_->GetLocation();
OatClassType type = static_cast<OatClassType>(*reinterpret_cast<const uint16_t*>(type_pointer));
CHECK_LT(type, kOatClassMax);
const uint8_t* after_type_pointer = type_pointer + sizeof(int16_t);
CHECK_LE(after_type_pointer, oat_file_->End()) << oat_file_->GetLocation();
uint32_t bitmap_size = 0;
const uint8_t* bitmap_pointer = nullptr;
const uint8_t* methods_pointer = nullptr;
if (type != kOatClassNoneCompiled) {
if (type == kOatClassSomeCompiled) {
bitmap_size = static_cast<uint32_t>(*reinterpret_cast<const uint32_t*>(after_type_pointer));
bitmap_pointer = after_type_pointer + sizeof(bitmap_size);
CHECK_LE(bitmap_pointer, oat_file_->End()) << oat_file_->GetLocation();
methods_pointer = bitmap_pointer + bitmap_size;
} else {
methods_pointer = after_type_pointer;
}
CHECK_LE(methods_pointer, oat_file_->End()) << oat_file_->GetLocation();
}
return OatFile::OatClass(oat_file_,
status,
type,
bitmap_size,
reinterpret_cast<const uint32_t*>(bitmap_pointer),
reinterpret_cast<const OatMethodOffsets*>(methods_pointer));
}
OatFile::OatClass::OatClass(const OatFile* oat_file,
mirror::Class::Status status,
OatClassType type,
uint32_t bitmap_size,
const uint32_t* bitmap_pointer,
const OatMethodOffsets* methods_pointer)
: oat_file_(oat_file), status_(status), type_(type),
bitmap_(bitmap_pointer), methods_pointer_(methods_pointer) {
switch (type_) {
case kOatClassAllCompiled: {
CHECK_EQ(0U, bitmap_size);
CHECK(bitmap_pointer == nullptr);
CHECK(methods_pointer != nullptr);
break;
}
case kOatClassSomeCompiled: {
CHECK_NE(0U, bitmap_size);
CHECK(bitmap_pointer != nullptr);
CHECK(methods_pointer != nullptr);
break;
}
case kOatClassNoneCompiled: {
CHECK_EQ(0U, bitmap_size);
CHECK(bitmap_pointer == nullptr);
CHECK(methods_pointer_ == nullptr);
break;
}
case kOatClassMax: {
LOG(FATAL) << "Invalid OatClassType " << type_;
break;
}
}
}
uint32_t OatFile::OatClass::GetOatMethodOffsetsOffset(uint32_t method_index) const {
const OatMethodOffsets* oat_method_offsets = GetOatMethodOffsets(method_index);
if (oat_method_offsets == nullptr) {
return 0u;
}
return reinterpret_cast<const uint8_t*>(oat_method_offsets) - oat_file_->Begin();
}
const OatMethodOffsets* OatFile::OatClass::GetOatMethodOffsets(uint32_t method_index) const {
// NOTE: We don't keep the number of methods and cannot do a bounds check for method_index.
if (methods_pointer_ == nullptr) {
CHECK_EQ(kOatClassNoneCompiled, type_);
return nullptr;
}
size_t methods_pointer_index;
if (bitmap_ == nullptr) {
CHECK_EQ(kOatClassAllCompiled, type_);
methods_pointer_index = method_index;
} else {
CHECK_EQ(kOatClassSomeCompiled, type_);
if (!BitVector::IsBitSet(bitmap_, method_index)) {
return nullptr;
}
size_t num_set_bits = BitVector::NumSetBits(bitmap_, method_index);
methods_pointer_index = num_set_bits;
}
const OatMethodOffsets& oat_method_offsets = methods_pointer_[methods_pointer_index];
return &oat_method_offsets;
}
const OatFile::OatMethod OatFile::OatClass::GetOatMethod(uint32_t method_index) const {
const OatMethodOffsets* oat_method_offsets = GetOatMethodOffsets(method_index);
if (oat_method_offsets == nullptr) {
return OatMethod(nullptr, 0);
}
if (oat_file_->IsExecutable() ||
Runtime::Current() == nullptr || // This case applies for oatdump.
Runtime::Current()->IsAotCompiler()) {
return OatMethod(oat_file_->Begin(), oat_method_offsets->code_offset_);
}
// We aren't allowed to use the compiled code. We just force it down the interpreted / jit
// version.
return OatMethod(oat_file_->Begin(), 0);
}
void OatFile::OatMethod::LinkMethod(ArtMethod* method) const {
CHECK(method != nullptr);
method->SetEntryPointFromQuickCompiledCode(GetQuickCode());
}
bool OatFile::HasPatchInfo() const {
return GetOatHeader().HasPatchInfo();
}
bool OatFile::IsPic() const {
return GetOatHeader().IsPic();
// TODO: Check against oat_patches. b/18144996
}
bool OatFile::IsDebuggable() const {
return GetOatHeader().IsDebuggable();
}
CompilerFilter::Filter OatFile::GetCompilerFilter() const {
return GetOatHeader().GetCompilerFilter();
}
static constexpr char kDexClassPathEncodingSeparator = '*';
std::string OatFile::EncodeDexFileDependencies(const std::vector<const DexFile*>& dex_files) {
std::ostringstream out;
for (const DexFile* dex_file : dex_files) {
out << dex_file->GetLocation().c_str();
out << kDexClassPathEncodingSeparator;
out << dex_file->GetLocationChecksum();
out << kDexClassPathEncodingSeparator;
}
return out.str();
}
bool OatFile::CheckStaticDexFileDependencies(const char* dex_dependencies, std::string* msg) {
if (dex_dependencies == nullptr || dex_dependencies[0] == 0) {
// No dependencies.
return true;
}
// Assumption: this is not performance-critical. So it's OK to do this with a std::string and
// Split() instead of manual parsing of the combined char*.
std::vector<std::string> split;
Split(dex_dependencies, kDexClassPathEncodingSeparator, &split);
if (split.size() % 2 != 0) {
// Expected pairs of location and checksum.
*msg = StringPrintf("Odd number of elements in dependency list %s", dex_dependencies);
return false;
}
for (auto it = split.begin(), end = split.end(); it != end; it += 2) {
std::string& location = *it;
std::string& checksum = *(it + 1);
int64_t converted = strtoll(checksum.c_str(), nullptr, 10);
if (converted == 0) {
// Conversion error.
*msg = StringPrintf("Conversion error for %s", checksum.c_str());
return false;
}
uint32_t dex_checksum;
std::string error_msg;
if (DexFile::GetChecksum(DexFile::GetDexCanonicalLocation(location.c_str()).c_str(),
&dex_checksum,
&error_msg)) {
if (converted != dex_checksum) {
*msg = StringPrintf("Checksums don't match for %s: %" PRId64 " vs %u",
location.c_str(), converted, dex_checksum);
return false;
}
} else {
// Problem retrieving checksum.
// TODO: odex files?
*msg = StringPrintf("Could not retrieve checksum for %s: %s", location.c_str(),
error_msg.c_str());
return false;
}
}
return true;
}
bool OatFile::GetDexLocationsFromDependencies(const char* dex_dependencies,
std::vector<std::string>* locations) {
DCHECK(locations != nullptr);
if (dex_dependencies == nullptr || dex_dependencies[0] == 0) {
return true;
}
// Assumption: this is not performance-critical. So it's OK to do this with a std::string and
// Split() instead of manual parsing of the combined char*.
std::vector<std::string> split;
Split(dex_dependencies, kDexClassPathEncodingSeparator, &split);
if (split.size() % 2 != 0) {
// Expected pairs of location and checksum.
return false;
}
for (auto it = split.begin(), end = split.end(); it != end; it += 2) {
locations->push_back(*it);
}
return true;
}
} // namespace art