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android/platform/art/android16-release/./runtime/class_loader_context.cc
blob: 6ede2027ddb458b22b6e29d4329e71375cc86f23 [file]
/*
* Copyright (C) 2017 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 "class_loader_context.h"
#include <algorithm>
#include <optional>
#include "android-base/file.h"
#include "android-base/parseint.h"
#include "android-base/strings.h"
#include "art_field-inl.h"
#include "base/casts.h"
#include "base/dchecked_vector.h"
#include "base/file_utils.h"
#include "base/stl_util.h"
#include "base/systrace.h"
#include "class_linker.h"
#include "class_loader_utils.h"
#include "class_root-inl.h"
#include "dex/art_dex_file_loader.h"
#include "dex/dex_file.h"
#include "dex/dex_file_loader.h"
#include "handle_scope-inl.h"
#include "jni/jni_internal.h"
#include "mirror/class_loader-inl.h"
#include "mirror/object.h"
#include "mirror/object_array-alloc-inl.h"
#include "nativehelper/scoped_local_ref.h"
#include "oat/oat_file_assistant.h"
#include "obj_ptr-inl.h"
#include "runtime.h"
#include "scoped_thread_state_change-inl.h"
#include "thread.h"
#include "well_known_classes-inl.h"
namespace art HIDDEN {
static constexpr char kPathClassLoaderString[] = "PCL";
static constexpr char kDelegateLastClassLoaderString[] = "DLC";
static constexpr char kInMemoryDexClassLoaderString[] = "IMC";
static constexpr char kClassLoaderOpeningMark = '[';
static constexpr char kClassLoaderClosingMark = ']';
static constexpr char kClassLoaderSharedLibraryOpeningMark = '{';
static constexpr char kClassLoaderSharedLibraryClosingMark = '}';
static constexpr char kClassLoaderSharedLibrarySeparator = '#';
static constexpr char kClassLoaderSharedLibraryAfterSeparator = '~';
static constexpr char kClassLoaderSeparator = ';';
static constexpr char kClasspathSeparator = ':';
static constexpr char kDexFileChecksumSeparator = '*';
static constexpr char kInMemoryDexClassLoaderDexLocationMagic[] = "<unknown>";
ClassLoaderContext::ClassLoaderContext()
: dex_files_state_(ContextDexFilesState::kDexFilesNotOpened), owns_the_dex_files_(true) {}
ClassLoaderContext::ClassLoaderContext(bool owns_the_dex_files)
: dex_files_state_(ContextDexFilesState::kDexFilesOpened),
owns_the_dex_files_(owns_the_dex_files) {}
// Utility method to add parent and shared libraries of `info` into
// the `work_list`.
static void AddToWorkList(ClassLoaderContext::ClassLoaderInfo* info,
std::vector<ClassLoaderContext::ClassLoaderInfo*>& work_list) {
if (info->parent != nullptr) {
work_list.push_back(info->parent.get());
}
for (size_t i = 0; i < info->shared_libraries.size(); ++i) {
work_list.push_back(info->shared_libraries[i].get());
}
for (size_t i = 0; i < info->shared_libraries_after.size(); ++i) {
work_list.push_back(info->shared_libraries_after[i].get());
}
}
ClassLoaderContext::~ClassLoaderContext() {
if (!owns_the_dex_files_ && class_loader_chain_ != nullptr) {
// If the context does not own the dex/oat files release the unique pointers to
// make sure we do not de-allocate them.
std::vector<ClassLoaderInfo*> work_list;
work_list.push_back(class_loader_chain_.get());
while (!work_list.empty()) {
ClassLoaderInfo* info = work_list.back();
work_list.pop_back();
for (std::unique_ptr<OatFile>& oat_file : info->opened_oat_files) {
oat_file.release(); // NOLINT b/117926937
}
for (std::unique_ptr<const DexFile>& dex_file : info->opened_dex_files) {
dex_file.release(); // NOLINT b/117926937
}
AddToWorkList(info, work_list);
}
}
}
std::unique_ptr<ClassLoaderContext> ClassLoaderContext::Default() { return Create(""); }
std::unique_ptr<ClassLoaderContext> ClassLoaderContext::Create(const std::string& spec) {
std::unique_ptr<ClassLoaderContext> result(new ClassLoaderContext());
if (result->Parse(spec)) {
return result;
} else {
return nullptr;
}
}
static size_t FindMatchingSharedLibraryCloseMarker(const std::string& spec,
size_t shared_library_open_index) {
// Counter of opened shared library marker we've encountered so far.
uint32_t counter = 1;
// The index at which we're operating in the loop.
uint32_t string_index = shared_library_open_index + 1;
size_t shared_library_close = std::string::npos;
while (counter != 0) {
shared_library_close = spec.find_first_of(kClassLoaderSharedLibraryClosingMark, string_index);
size_t shared_library_open =
spec.find_first_of(kClassLoaderSharedLibraryOpeningMark, string_index);
if (shared_library_close == std::string::npos) {
// No matching closing marker. Return an error.
break;
}
if ((shared_library_open == std::string::npos) ||
(shared_library_close < shared_library_open)) {
// We have seen a closing marker. Decrement the counter.
--counter;
// Move the search index forward.
string_index = shared_library_close + 1;
} else {
// New nested opening marker. Increment the counter and move the search
// index after the marker.
++counter;
string_index = shared_library_open + 1;
}
}
return shared_library_close;
}
// The expected format is:
// "ClassLoaderType1[ClasspathElem1*Checksum1:ClasspathElem2*Checksum2...]{ClassLoaderType2[...]}".
// The checksum part of the format is expected only if parse_cheksums is true.
std::unique_ptr<ClassLoaderContext::ClassLoaderInfo> ClassLoaderContext::ParseClassLoaderSpec(
const std::string& class_loader_spec, bool parse_checksums) {
ClassLoaderType class_loader_type = ExtractClassLoaderType(class_loader_spec);
if (class_loader_type == kInvalidClassLoader) {
return nullptr;
}
// InMemoryDexClassLoader's dex location is always bogus. Special-case it.
if (class_loader_type == kInMemoryDexClassLoader) {
if (parse_checksums) {
// Make sure that OpenDexFiles() will never be attempted on this context
// because the dex locations of IMC do not correspond to real files.
CHECK(dex_files_state_ == kDexFilesNotOpened || dex_files_state_ == kDexFilesOpenFailed)
<< "Parsing spec not supported when context created from a ClassLoader object: "
<< "dex_files_state_=" << dex_files_state_;
dex_files_state_ = kDexFilesOpenFailed;
} else {
// Checksums are not provided and dex locations themselves have no meaning
// (although we keep them in the spec to simplify parsing). Treat this as
// an unknown class loader.
// We can hit this case if dex2oat is invoked with a spec containing IMC.
// Because the dex file data is only available at runtime, we cannot proceed.
return nullptr;
}
}
const char* class_loader_type_str = GetClassLoaderTypeName(class_loader_type);
size_t type_str_size = strlen(class_loader_type_str);
CHECK_EQ(0, class_loader_spec.compare(0, type_str_size, class_loader_type_str));
// Check the opening and closing markers.
if (class_loader_spec[type_str_size] != kClassLoaderOpeningMark) {
return nullptr;
}
if ((class_loader_spec[class_loader_spec.length() - 1] != kClassLoaderClosingMark) &&
(class_loader_spec[class_loader_spec.length() - 1] != kClassLoaderSharedLibraryClosingMark)) {
return nullptr;
}
size_t closing_index = class_loader_spec.find_first_of(kClassLoaderClosingMark);
// At this point we know the format is ok; continue and extract the classpath.
// Note that class loaders with an empty class path are allowed.
std::string classpath =
class_loader_spec.substr(type_str_size + 1, closing_index - type_str_size - 1);
std::unique_ptr<ClassLoaderInfo> info(new ClassLoaderInfo(class_loader_type));
if (!parse_checksums) {
DCHECK(class_loader_type != kInMemoryDexClassLoader);
Split(classpath, kClasspathSeparator, &info->classpath);
} else {
std::vector<std::string> classpath_elements;
Split(classpath, kClasspathSeparator, &classpath_elements);
for (const std::string& element : classpath_elements) {
std::vector<std::string> dex_file_with_checksum;
Split(element, kDexFileChecksumSeparator, &dex_file_with_checksum);
if (dex_file_with_checksum.size() != 2) {
return nullptr;
}
uint32_t checksum = 0;
if (!android::base::ParseUint(dex_file_with_checksum[1].c_str(), &checksum)) {
return nullptr;
}
if ((class_loader_type == kInMemoryDexClassLoader) &&
(dex_file_with_checksum[0] != kInMemoryDexClassLoaderDexLocationMagic)) {
return nullptr;
}
info->classpath.push_back(dex_file_with_checksum[0]);
info->checksums.push_back(checksum);
}
}
if ((class_loader_spec[class_loader_spec.length() - 1] == kClassLoaderSharedLibraryClosingMark) &&
(class_loader_spec[class_loader_spec.length() - 2] != kClassLoaderSharedLibraryOpeningMark)) {
// Non-empty list of shared libraries.
size_t start_index = class_loader_spec.find_first_of(kClassLoaderSharedLibraryOpeningMark);
if (start_index == std::string::npos) {
return nullptr;
}
std::string shared_libraries_spec =
class_loader_spec.substr(start_index + 1, class_loader_spec.length() - start_index - 2);
std::vector<std::string> shared_libraries;
size_t cursor = 0;
while (cursor != shared_libraries_spec.length()) {
bool is_after = false;
size_t shared_library_separator =
shared_libraries_spec.find_first_of(kClassLoaderSharedLibrarySeparator, cursor);
size_t shared_library_open =
shared_libraries_spec.find_first_of(kClassLoaderSharedLibraryOpeningMark, cursor);
std::string shared_library_spec;
if (shared_library_separator == std::string::npos) {
// Only one shared library, for example:
// PCL[...]
if (shared_libraries_spec[cursor] == kClassLoaderSharedLibraryAfterSeparator) {
// This library was marked to be loaded after the dex path
is_after = true;
// Pass the shared library after separator marker.
++cursor;
}
shared_library_spec =
shared_libraries_spec.substr(cursor, shared_libraries_spec.length() - cursor);
cursor = shared_libraries_spec.length();
} else if ((shared_library_open == std::string::npos) ||
(shared_library_open > shared_library_separator)) {
// We found a shared library without nested shared libraries, for example:
// PCL[...]#PCL[...]{...}
if (shared_libraries_spec[cursor] == kClassLoaderSharedLibraryAfterSeparator) {
// This library was marked to be loaded after the dex path
is_after = true;
// Pass the shared library after separator marker.
++cursor;
}
shared_library_spec =
shared_libraries_spec.substr(cursor, shared_library_separator - cursor);
cursor = shared_library_separator + 1;
} else {
// The shared library contains nested shared libraries. Find the matching closing shared
// marker for it.
size_t closing_marker =
FindMatchingSharedLibraryCloseMarker(shared_libraries_spec, shared_library_open);
if (closing_marker == std::string::npos) {
// No matching closing marker, return an error.
return nullptr;
}
if (shared_libraries_spec[cursor] == kClassLoaderSharedLibraryAfterSeparator) {
// This library was marked to be loaded after the dex path
is_after = true;
// Pass the shared library after separator marker.
++cursor;
}
shared_library_spec = shared_libraries_spec.substr(cursor, closing_marker + 1 - cursor);
cursor = closing_marker + 1;
if (cursor != shared_libraries_spec.length() &&
shared_libraries_spec[cursor] == kClassLoaderSharedLibrarySeparator) {
// Pass the shared library separator marker.
++cursor;
}
}
std::unique_ptr<ClassLoaderInfo> shared_library_info(
ParseInternal(shared_library_spec, parse_checksums));
if (shared_library_info == nullptr) {
return nullptr;
}
if (is_after) {
info->shared_libraries_after.push_back(std::move(shared_library_info));
} else {
info->shared_libraries.push_back(std::move(shared_library_info));
}
}
}
return info;
}
// Extracts the class loader type from the given spec.
// Return ClassLoaderContext::kInvalidClassLoader if the class loader type is not
// recognized.
ClassLoaderContext::ClassLoaderType ClassLoaderContext::ExtractClassLoaderType(
const std::string& class_loader_spec) {
const ClassLoaderType kValidTypes[] = {
kPathClassLoader, kDelegateLastClassLoader, kInMemoryDexClassLoader};
for (const ClassLoaderType& type : kValidTypes) {
const char* type_str = GetClassLoaderTypeName(type);
if (class_loader_spec.compare(0, strlen(type_str), type_str) == 0) {
return type;
}
}
return kInvalidClassLoader;
}
// The format: ClassLoaderType1[ClasspathElem1:ClasspathElem2...];ClassLoaderType2[...]...
// ClassLoaderType is either "PCL" (PathClassLoader) or "DLC" (DelegateLastClassLoader).
// ClasspathElem is the path of dex/jar/apk file.
bool ClassLoaderContext::Parse(const std::string& spec, bool parse_checksums) {
if (spec.empty()) {
// By default we load the dex files in a PathClassLoader.
// So an empty spec is equivalent to an empty PathClassLoader (this happens when running
// tests)
class_loader_chain_.reset(new ClassLoaderInfo(kPathClassLoader));
return true;
}
CHECK(class_loader_chain_ == nullptr);
class_loader_chain_.reset(ParseInternal(spec, parse_checksums));
return class_loader_chain_ != nullptr;
}
ClassLoaderContext::ClassLoaderInfo* ClassLoaderContext::ParseInternal(const std::string& spec,
bool parse_checksums) {
CHECK(!spec.empty());
std::string remaining = spec;
std::unique_ptr<ClassLoaderInfo> first(nullptr);
ClassLoaderInfo* previous_iteration = nullptr;
while (!remaining.empty()) {
std::string class_loader_spec;
size_t first_class_loader_separator = remaining.find_first_of(kClassLoaderSeparator);
size_t first_shared_library_open =
remaining.find_first_of(kClassLoaderSharedLibraryOpeningMark);
if (first_class_loader_separator == std::string::npos) {
// Only one class loader, for example:
// PCL[...]
class_loader_spec = remaining;
remaining = "";
} else if ((first_shared_library_open == std::string::npos) ||
(first_shared_library_open > first_class_loader_separator)) {
// We found a class loader spec without shared libraries, for example:
// PCL[...];PCL[...]{...}
class_loader_spec = remaining.substr(0, first_class_loader_separator);
remaining = remaining.substr(first_class_loader_separator + 1,
remaining.size() - first_class_loader_separator - 1);
} else {
// The class loader spec contains shared libraries. Find the matching closing
// shared library marker for it.
size_t shared_library_close =
FindMatchingSharedLibraryCloseMarker(remaining, first_shared_library_open);
if (shared_library_close == std::string::npos) {
LOG(ERROR) << "Invalid class loader spec: " << class_loader_spec;
return nullptr;
}
class_loader_spec = remaining.substr(0, shared_library_close + 1);
// Compute the remaining string to analyze.
if (remaining.size() == shared_library_close + 1) {
remaining = "";
} else if ((remaining.size() == shared_library_close + 2) ||
(remaining.at(shared_library_close + 1) != kClassLoaderSeparator)) {
LOG(ERROR) << "Invalid class loader spec: " << class_loader_spec;
return nullptr;
} else {
remaining =
remaining.substr(shared_library_close + 2, remaining.size() - shared_library_close - 2);
}
}
std::unique_ptr<ClassLoaderInfo> info =
ParseClassLoaderSpec(class_loader_spec, parse_checksums);
if (info == nullptr) {
LOG(ERROR) << "Invalid class loader spec: " << class_loader_spec;
return nullptr;
}
if (first == nullptr) {
first = std::move(info);
previous_iteration = first.get();
} else {
CHECK(previous_iteration != nullptr);
previous_iteration->parent = std::move(info);
previous_iteration = previous_iteration->parent.get();
}
}
return first.release();
}
// Opens requested class path files and appends them to opened_dex_files. If the dex files have
// been stripped, this opens them from their oat files (which get added to opened_oat_files).
bool ClassLoaderContext::OpenDexFiles(const std::string& classpath_dir,
const std::vector<int>& fds,
bool only_read_checksums) {
switch (dex_files_state_) {
case kDexFilesNotOpened:
break; // files not opened, continue.
case kDexFilesOpenFailed:
return false; // previous attempt failed.
case kDexFilesOpened:
return true; // previous attempt succeed.
case kDexFilesChecksumsRead:
if (only_read_checksums) {
return true; // we already read the checksums.
} else {
break; // we already read the checksums but have to open the dex files; continue.
}
}
// Assume we can open the files. If not, we will adjust as we go.
dex_files_state_ = only_read_checksums ? kDexFilesChecksumsRead : kDexFilesOpened;
// Note that we try to open all dex files even if some fail.
// We may get resource-only apks which we cannot load.
// TODO(calin): Refine the dex opening interface to be able to tell if an archive contains
// no dex files. So that we can distinguish the real failures...
std::vector<ClassLoaderInfo*> work_list;
if (class_loader_chain_ == nullptr) {
return true;
}
work_list.push_back(class_loader_chain_.get());
size_t dex_file_index = 0;
while (!work_list.empty()) {
ClassLoaderInfo* info = work_list.back();
work_list.pop_back();
DCHECK(info->type != kInMemoryDexClassLoader) << __FUNCTION__ << " not supported for IMC";
// Holds the dex locations for the classpath files we've opened.
std::vector<std::string> dex_locations;
// Holds the checksums for the classpath files we've opened.
std::vector<uint32_t> dex_checksums;
for (const std::string& cp_elem : info->classpath) {
// If path is relative, append it to the provided base directory.
std::string location = cp_elem;
if (location[0] != '/' && !classpath_dir.empty()) {
location =
ART_FORMAT("{}{}{}", classpath_dir, classpath_dir.back() == '/' ? "" : "/", location);
}
// If file descriptors were provided for the class loader context dex paths,
// get the descriptor which corresponds to this dex path. We assume the `fds`
// vector follows the same order as a flattened class loader context.
File file;
if (!fds.empty()) {
if (dex_file_index >= fds.size()) {
LOG(WARNING) << "Number of FDs is smaller than number of dex files in the context";
dex_files_state_ = kDexFilesOpenFailed;
return false;
}
file = File(fds[dex_file_index++], /*check_usage=*/false);
DCHECK(file.IsValid());
}
std::string error_msg;
std::optional<uint32_t> dex_checksum;
if (only_read_checksums) {
bool zip_file_only_contains_uncompress_dex;
ArtDexFileLoader dex_file_loader(&file, location);
if (!dex_file_loader.GetMultiDexChecksum(
&dex_checksum, &error_msg, &zip_file_only_contains_uncompress_dex)) {
LOG(WARNING) << "Could not get dex checksums for location " << location
<< ", fd=" << file.Fd();
dex_files_state_ = kDexFilesOpenFailed;
}
file.Release(); // Don't close the file yet (we have only read the checksum).
} else {
// When opening the dex files from the context we expect their checksum to match their
// contents. So pass true to verify_checksum.
// We don't need to do structural dex file verification, we only need to
// check the checksum, so pass false to verify.
size_t i = info->opened_dex_files.size();
ArtDexFileLoader dex_file_loader(&file, location);
if (!dex_file_loader.Open(/*verify=*/false,
/*verify_checksum=*/true,
&error_msg,
&info->opened_dex_files)) {
LOG(WARNING) << "Could not open dex files for location " << location
<< ", fd=" << file.Fd();
dex_files_state_ = kDexFilesOpenFailed;
} else {
dex_checksum = DexFileLoader::GetMultiDexChecksum(info->opened_dex_files, &i);
DCHECK_EQ(i, info->opened_dex_files.size());
}
}
if (dex_checksum.has_value()) {
dex_locations.push_back(location);
dex_checksums.push_back(dex_checksum.value());
}
}
// We finished opening the dex files from the classpath.
// Now update the classpath and the checksum with the locations of the dex files.
//
// We do this because initially the classpath contains the paths of the dex files; and
// some of them might be multi-dexes. So in order to have a consistent view we replace all the
// file paths with the actual dex locations being loaded.
// This will allow the context to VerifyClassLoaderContextMatch which expects or multidex
// location in the class paths.
// Note that this will also remove the paths that could not be opened.
info->original_classpath = std::move(info->classpath);
DCHECK(dex_locations.size() == dex_checksums.size());
info->classpath = std::move(dex_locations);
info->checksums = std::move(dex_checksums);
AddToWorkList(info, work_list);
}
// Check that if file descriptors were provided, there were exactly as many
// as we have encountered while iterating over this class loader context.
if (dex_file_index != fds.size()) {
LOG(WARNING) << fds.size() << " FDs provided but only " << dex_file_index
<< " dex files are in the class loader context";
dex_files_state_ = kDexFilesOpenFailed;
}
return dex_files_state_ != kDexFilesOpenFailed;
}
bool ClassLoaderContext::RemoveLocationsFromClassPaths(
const dchecked_vector<std::string>& locations) {
CHECK_EQ(dex_files_state_, kDexFilesNotOpened)
<< "RemoveLocationsFromClasspaths cannot be call after OpenDexFiles";
if (class_loader_chain_ == nullptr) {
return false;
}
std::set<std::string> canonical_locations;
for (const std::string& location : locations) {
canonical_locations.insert(DexFileLoader::GetDexCanonicalLocation(location.c_str()));
}
bool removed_locations = false;
std::vector<ClassLoaderInfo*> work_list;
work_list.push_back(class_loader_chain_.get());
while (!work_list.empty()) {
ClassLoaderInfo* info = work_list.back();
work_list.pop_back();
size_t initial_size = info->classpath.size();
auto kept_it = std::remove_if(info->classpath.begin(),
info->classpath.end(),
[canonical_locations](const std::string& location) {
return ContainsElement(
canonical_locations,
DexFileLoader::GetDexCanonicalLocation(location.c_str()));
});
info->classpath.erase(kept_it, info->classpath.end());
if (initial_size != info->classpath.size()) {
removed_locations = true;
}
AddToWorkList(info, work_list);
}
return removed_locations;
}
std::string ClassLoaderContext::EncodeContextForDex2oat(const std::string& base_dir) const {
return EncodeContext(base_dir, /*for_dex2oat=*/true, /*stored_context=*/nullptr);
}
std::string ClassLoaderContext::EncodeContextForOatFile(const std::string& base_dir,
ClassLoaderContext* stored_context) const {
return EncodeContext(base_dir, /*for_dex2oat=*/false, stored_context);
}
std::map<std::string, std::string> ClassLoaderContext::EncodeClassPathContexts(
const std::string& base_dir) const {
CheckDexFilesOpened("EncodeClassPathContexts");
if (class_loader_chain_ == nullptr) {
return std::map<std::string, std::string>{};
}
std::map<std::string, std::string> results;
std::vector<std::string> dex_locations;
std::vector<uint32_t> checksums;
dex_locations.reserve(class_loader_chain_->original_classpath.size());
std::ostringstream encoded_libs_and_parent_stream;
EncodeSharedLibAndParent(*class_loader_chain_,
base_dir,
/*for_dex2oat=*/true,
/*stored_info=*/nullptr,
encoded_libs_and_parent_stream);
std::string encoded_libs_and_parent(encoded_libs_and_parent_stream.str());
std::set<std::string> seen_locations;
for (const std::string& path : class_loader_chain_->classpath) {
// The classpath will contain multiple entries for multidex files, so make sure this is the
// first time we're seeing this file.
const std::string base_location(DexFileLoader::GetBaseLocation(path));
if (!seen_locations.insert(base_location).second) {
continue;
}
std::ostringstream out;
EncodeClassPath(base_dir, dex_locations, checksums, class_loader_chain_->type, out);
out << encoded_libs_and_parent;
results.emplace(base_location, out.str());
dex_locations.push_back(base_location);
}
return results;
}
std::string ClassLoaderContext::EncodeContext(const std::string& base_dir,
bool for_dex2oat,
ClassLoaderContext* stored_context) const {
CheckDexFilesOpened("EncodeContextForOatFile");
if (stored_context != nullptr) {
DCHECK_EQ(GetParentChainSize(), stored_context->GetParentChainSize());
}
std::ostringstream out;
if (class_loader_chain_ == nullptr) {
// We can get in this situation if the context was created with a class path containing the
// source dex files which were later removed (happens during run-tests).
out << GetClassLoaderTypeName(kPathClassLoader) << kClassLoaderOpeningMark
<< kClassLoaderClosingMark;
return out.str();
}
EncodeContextInternal(
*class_loader_chain_,
base_dir,
for_dex2oat,
(stored_context == nullptr ? nullptr : stored_context->class_loader_chain_.get()),
out);
return out.str();
}
void ClassLoaderContext::EncodeClassPath(const std::string& base_dir,
const std::vector<std::string>& dex_locations,
const std::vector<uint32_t>& checksums,
ClassLoaderType type,
std::ostringstream& out) const {
CHECK(checksums.empty() || dex_locations.size() == checksums.size());
out << GetClassLoaderTypeName(type);
out << kClassLoaderOpeningMark;
const size_t len = dex_locations.size();
for (size_t k = 0; k < len; k++) {
const std::string& location = dex_locations[k];
if (k > 0) {
out << kClasspathSeparator;
}
if (type == kInMemoryDexClassLoader) {
out << kInMemoryDexClassLoaderDexLocationMagic;
} else if (!base_dir.empty() && location.substr(0, base_dir.length()) == base_dir) {
// Find paths that were relative and convert them back from absolute.
out << location.substr(base_dir.length() + 1).c_str();
} else {
out << location.c_str();
}
if (!checksums.empty()) {
out << kDexFileChecksumSeparator;
out << checksums[k];
}
}
out << kClassLoaderClosingMark;
}
void ClassLoaderContext::EncodeContextInternal(const ClassLoaderInfo& info,
const std::string& base_dir,
bool for_dex2oat,
ClassLoaderInfo* stored_info,
std::ostringstream& out) const {
std::vector<std::string> locations;
std::vector<uint32_t> checksums;
std::set<std::string> seen_locations;
SafeMap<std::string, std::string> remap;
if (stored_info != nullptr) {
for (size_t k = 0; k < info.original_classpath.size(); ++k) {
// Note that we don't care if the same name appears twice.
remap.Put(info.original_classpath[k], stored_info->classpath[k]);
}
}
DCHECK_EQ(info.classpath.size(), info.checksums.size());
for (size_t i = 0; i < info.classpath.size(); i++) {
if (for_dex2oat) {
// De-duplicate locations.
bool new_insert = seen_locations.insert(info.classpath[i]).second;
if (!new_insert) {
continue;
}
}
std::string location = info.classpath[i];
// If there is a stored class loader remap, fix up the multidex strings.
if (!remap.empty()) {
auto it = remap.find(location);
CHECK(it != remap.end()) << location;
location = it->second;
}
locations.emplace_back(std::move(location));
// dex2oat does not need the checksums.
if (!for_dex2oat) {
checksums.push_back(info.checksums[i]);
}
}
EncodeClassPath(base_dir, locations, checksums, info.type, out);
EncodeSharedLibAndParent(info, base_dir, for_dex2oat, stored_info, out);
}
void ClassLoaderContext::EncodeSharedLibAndParent(const ClassLoaderInfo& info,
const std::string& base_dir,
bool for_dex2oat,
ClassLoaderInfo* stored_info,
std::ostringstream& out) const {
if (!info.shared_libraries.empty() || !info.shared_libraries_after.empty()) {
out << kClassLoaderSharedLibraryOpeningMark;
for (uint32_t i = 0; i < info.shared_libraries.size(); ++i) {
if (i > 0) {
out << kClassLoaderSharedLibrarySeparator;
}
EncodeContextInternal(
*info.shared_libraries[i].get(),
base_dir,
for_dex2oat,
(stored_info == nullptr ? nullptr : stored_info->shared_libraries[i].get()),
out);
}
for (uint32_t i = 0; i < info.shared_libraries_after.size(); ++i) {
if (i > 0 || !info.shared_libraries.empty()) {
out << kClassLoaderSharedLibrarySeparator;
}
out << kClassLoaderSharedLibraryAfterSeparator;
EncodeContextInternal(
*info.shared_libraries_after[i].get(),
base_dir,
for_dex2oat,
(stored_info == nullptr ? nullptr : stored_info->shared_libraries_after[i].get()),
out);
}
out << kClassLoaderSharedLibraryClosingMark;
}
if (info.parent != nullptr) {
out << kClassLoaderSeparator;
EncodeContextInternal(*info.parent.get(),
base_dir,
for_dex2oat,
(stored_info == nullptr ? nullptr : stored_info->parent.get()),
out);
}
}
// Returns the WellKnownClass for the given class loader type.
static ObjPtr<mirror::Class> GetClassLoaderClass(ClassLoaderContext::ClassLoaderType type)
REQUIRES_SHARED(Locks::mutator_lock_) {
switch (type) {
case ClassLoaderContext::kPathClassLoader:
return WellKnownClasses::dalvik_system_PathClassLoader.Get();
case ClassLoaderContext::kDelegateLastClassLoader:
return WellKnownClasses::dalvik_system_DelegateLastClassLoader.Get();
case ClassLoaderContext::kInMemoryDexClassLoader:
return WellKnownClasses::dalvik_system_InMemoryDexClassLoader.Get();
case ClassLoaderContext::kInvalidClassLoader:
break; // will fail after the switch.
}
LOG(FATAL) << "Invalid class loader type " << type;
UNREACHABLE();
}
static std::string FlattenClasspath(const std::vector<std::string>& classpath) {
return android::base::Join(classpath, ':');
}
static ObjPtr<mirror::ClassLoader> CreateClassLoaderInternal(
Thread* self,
ScopedObjectAccess& soa,
const ClassLoaderContext::ClassLoaderInfo& info,
bool for_shared_library,
VariableSizedHandleScope& map_scope,
std::map<std::string, Handle<mirror::ClassLoader>>& canonicalized_libraries,
bool add_compilation_sources,
const std::vector<const DexFile*>& compilation_sources) REQUIRES_SHARED(Locks::mutator_lock_) {
if (for_shared_library) {
// Check if the shared library has already been created.
auto search = canonicalized_libraries.find(FlattenClasspath(info.classpath));
if (search != canonicalized_libraries.end()) {
return search->second.Get();
}
}
StackHandleScope<4> hs(self);
MutableHandle<mirror::ObjectArray<mirror::ClassLoader>> libraries(
hs.NewHandle<mirror::ObjectArray<mirror::ClassLoader>>(nullptr));
MutableHandle<mirror::ObjectArray<mirror::ClassLoader>> libraries_after(
hs.NewHandle<mirror::ObjectArray<mirror::ClassLoader>>(nullptr));
if (!info.shared_libraries.empty()) {
libraries.Assign(mirror::ObjectArray<mirror::ClassLoader>::Alloc(
self,
GetClassRoot<mirror::ObjectArray<mirror::ClassLoader>>(),
info.shared_libraries.size()));
for (uint32_t i = 0; i < info.shared_libraries.size(); ++i) {
// We should only add the compilation sources to the first class loader.
libraries->Set(i,
CreateClassLoaderInternal(self,
soa,
*info.shared_libraries[i].get(),
/* for_shared_library= */ true,
map_scope,
canonicalized_libraries,
/* add_compilation_sources= */ false,
compilation_sources));
}
}
if (!info.shared_libraries_after.empty()) {
libraries_after.Assign(mirror::ObjectArray<mirror::ClassLoader>::Alloc(
self,
GetClassRoot<mirror::ObjectArray<mirror::ClassLoader>>(),
info.shared_libraries_after.size()));
for (uint32_t i = 0; i < info.shared_libraries_after.size(); ++i) {
// We should only add the compilation sources to the first class loader.
libraries_after->Set(i,
CreateClassLoaderInternal(self,
soa,
*info.shared_libraries_after[i].get(),
/* for_shared_library= */ true,
map_scope,
canonicalized_libraries,
/* add_compilation_sources= */ false,
compilation_sources));
}
}
MutableHandle<mirror::ClassLoader> parent = hs.NewHandle<mirror::ClassLoader>(nullptr);
if (info.parent != nullptr) {
// We should only add the compilation sources to the first class loader.
parent.Assign(CreateClassLoaderInternal(self,
soa,
*info.parent.get(),
/* for_shared_library= */ false,
map_scope,
canonicalized_libraries,
/* add_compilation_sources= */ false,
compilation_sources));
}
std::vector<const DexFile*> class_path_files = MakeNonOwningPointerVector(info.opened_dex_files);
if (add_compilation_sources) {
// For the first class loader, its classpath comes first, followed by compilation sources.
// This ensures that whenever we need to resolve classes from it the classpath elements
// come first.
class_path_files.insert(
class_path_files.end(), compilation_sources.begin(), compilation_sources.end());
}
Handle<mirror::Class> loader_class = hs.NewHandle<mirror::Class>(GetClassLoaderClass(info.type));
ObjPtr<mirror::ClassLoader> loader =
Runtime::Current()->GetClassLinker()->CreateWellKnownClassLoader(
self, class_path_files, loader_class, parent, libraries, libraries_after);
if (for_shared_library) {
canonicalized_libraries[FlattenClasspath(info.classpath)] =
map_scope.NewHandle<mirror::ClassLoader>(loader);
}
return loader;
}
jobject ClassLoaderContext::CreateClassLoader(
const std::vector<const DexFile*>& compilation_sources) const {
CheckDexFilesOpened("CreateClassLoader");
Thread* self = Thread::Current();
ScopedObjectAccess soa(self);
CHECK(class_loader_chain_ != nullptr);
// Create a map of canonicalized shared libraries. As we're holding objects,
// we're creating a variable size handle scope to put handles in the map.
VariableSizedHandleScope map_scope(self);
std::map<std::string, Handle<mirror::ClassLoader>> canonicalized_libraries;
// Create the class loader.
ObjPtr<mirror::ClassLoader> loader =
CreateClassLoaderInternal(self,
soa,
*class_loader_chain_.get(),
/* for_shared_library= */ false,
map_scope,
canonicalized_libraries,
/* add_compilation_sources= */ true,
compilation_sources);
// Make it a global ref and return.
ScopedLocalRef<jobject> local_ref(soa.Env(), soa.Env()->AddLocalReference<jobject>(loader));
return soa.Env()->NewGlobalRef(local_ref.get());
}
std::vector<const DexFile*> ClassLoaderContext::FlattenOpenedDexFiles() const {
CheckDexFilesOpened("FlattenOpenedDexFiles");
std::vector<const DexFile*> result;
if (class_loader_chain_ == nullptr) {
return result;
}
std::vector<ClassLoaderInfo*> work_list;
work_list.push_back(class_loader_chain_.get());
while (!work_list.empty()) {
ClassLoaderInfo* info = work_list.back();
work_list.pop_back();
for (const std::unique_ptr<const DexFile>& dex_file : info->opened_dex_files) {
result.push_back(dex_file.get());
}
AddToWorkList(info, work_list);
}
return result;
}
std::vector<std::string> ClassLoaderContext::FlattenDexPaths() const {
std::vector<std::string> result;
if (class_loader_chain_ == nullptr) {
return result;
}
std::vector<ClassLoaderInfo*> work_list;
work_list.push_back(class_loader_chain_.get());
while (!work_list.empty()) {
ClassLoaderInfo* info = work_list.back();
work_list.pop_back();
for (const std::string& dex_path : info->classpath) {
result.push_back(dex_path);
}
AddToWorkList(info, work_list);
}
return result;
}
const char* ClassLoaderContext::GetClassLoaderTypeName(ClassLoaderType type) {
switch (type) {
case kPathClassLoader:
return kPathClassLoaderString;
case kDelegateLastClassLoader:
return kDelegateLastClassLoaderString;
case kInMemoryDexClassLoader:
return kInMemoryDexClassLoaderString;
default:
LOG(FATAL) << "Invalid class loader type " << type;
UNREACHABLE();
}
}
void ClassLoaderContext::CheckDexFilesOpened(const std::string& calling_method) const {
CHECK_NE(dex_files_state_, kDexFilesNotOpened)
<< "Dex files were not successfully opened before the call to " << calling_method
<< "status=" << dex_files_state_;
}
// Collects the dex files from the give Java dex_file object. Only the dex files with
// at least 1 class are collected. If a null java_dex_file is passed this method does nothing.
static bool CollectDexFilesFromJavaDexFile(ObjPtr<mirror::Object> java_dex_file,
ArtField* const cookie_field,
std::vector<const DexFile*>* out_dex_files)
REQUIRES_SHARED(Locks::mutator_lock_) {
if (java_dex_file == nullptr) {
return true;
}
// On the Java side, the dex files are stored in the cookie field.
ObjPtr<mirror::LongArray> long_array = cookie_field->GetObject(java_dex_file)->AsLongArray();
if (long_array == nullptr) {
// This should never happen so log a warning.
LOG(ERROR) << "Unexpected null cookie";
return false;
}
int32_t long_array_size = long_array->GetLength();
// Index 0 from the long array stores the oat file. The dex files start at index 1.
for (int32_t j = 1; j < long_array_size; ++j) {
const DexFile* cp_dex_file =
reinterpret_cast64<const DexFile*>(long_array->GetWithoutChecks(j));
if (cp_dex_file != nullptr && cp_dex_file->NumClassDefs() > 0) {
// TODO(calin): It's unclear why the dex files with no classes are skipped here and when
// cp_dex_file can be null.
out_dex_files->push_back(cp_dex_file);
}
}
return true;
}
// Collects all the dex files loaded by the given class loader.
// Returns true for success or false if an unexpected state is discovered (e.g. a null dex cookie,
// a null list of dex elements or a null dex element).
static bool CollectDexFilesFromSupportedClassLoader(Thread* self,
Handle<mirror::ClassLoader> class_loader,
std::vector<const DexFile*>* out_dex_files)
REQUIRES_SHARED(Locks::mutator_lock_) {
CHECK(IsInstanceOfBaseDexClassLoader(class_loader));
// All supported class loaders inherit from BaseDexClassLoader.
// We need to get the DexPathList and loop through it.
ArtField* const cookie_field = WellKnownClasses::dalvik_system_DexFile_cookie;
ArtField* const dex_file_field = WellKnownClasses::dalvik_system_DexPathList__Element_dexFile;
ObjPtr<mirror::Object> dex_path_list =
WellKnownClasses::dalvik_system_BaseDexClassLoader_pathList->GetObject(class_loader.Get());
CHECK(cookie_field != nullptr);
CHECK(dex_file_field != nullptr);
if (dex_path_list == nullptr) {
// This may be null if the current class loader is under construction and it does not
// have its fields setup yet.
return true;
}
// DexPathList has an array dexElements of Elements[] which each contain a dex file.
ObjPtr<mirror::Object> dex_elements_obj =
WellKnownClasses::dalvik_system_DexPathList_dexElements->GetObject(dex_path_list);
// Loop through each dalvik.system.DexPathList$Element's dalvik.system.DexFile and look
// at the mCookie which is a DexFile vector.
if (dex_elements_obj == nullptr) {
// TODO(calin): It's unclear if we should just assert here. For now be prepared for the worse
// and assume we have no elements.
return true;
} else {
StackHandleScope<1> hs(self);
Handle<mirror::ObjectArray<mirror::Object>> dex_elements(
hs.NewHandle(dex_elements_obj->AsObjectArray<mirror::Object>()));
for (auto element : dex_elements.Iterate<mirror::Object>()) {
if (element == nullptr) {
// Should never happen, log an error and break.
// TODO(calin): It's unclear if we should just assert here.
// This code was propagated to oat_file_manager from the class linker where it would
// throw a NPE. For now, return false which will mark this class loader as unsupported.
LOG(ERROR) << "Unexpected null in the dex element list";
return false;
}
ObjPtr<mirror::Object> dex_file = dex_file_field->GetObject(element);
if (!CollectDexFilesFromJavaDexFile(dex_file, cookie_field, out_dex_files)) {
return false;
}
}
}
return true;
}
static bool GetDexFilesFromDexElementsArray(
Handle<mirror::ObjectArray<mirror::Object>> dex_elements,
std::vector<const DexFile*>* out_dex_files) REQUIRES_SHARED(Locks::mutator_lock_) {
DCHECK(dex_elements != nullptr);
ArtField* const cookie_field = WellKnownClasses::dalvik_system_DexFile_cookie;
ArtField* const dex_file_field = WellKnownClasses::dalvik_system_DexPathList__Element_dexFile;
const ObjPtr<mirror::Class> element_class =
WellKnownClasses::dalvik_system_DexPathList__Element.Get();
const ObjPtr<mirror::Class> dexfile_class = WellKnownClasses::dalvik_system_DexFile.Get();
for (auto element : dex_elements.Iterate<mirror::Object>()) {
// We can hit a null element here because this is invoked with a partially filled dex_elements
// array from DexPathList. DexPathList will open each dex sequentially, each time passing the
// list of dex files which were opened before.
if (element == nullptr) {
continue;
}
// We support this being dalvik.system.DexPathList$Element and dalvik.system.DexFile.
// TODO(calin): Code caried over oat_file_manager: supporting both classes seem to be
// a historical glitch. All the java code opens dex files using an array of Elements.
ObjPtr<mirror::Object> dex_file;
if (element_class == element->GetClass()) {
dex_file = dex_file_field->GetObject(element);
} else if (dexfile_class == element->GetClass()) {
dex_file = element;
} else {
LOG(ERROR) << "Unsupported element in dex_elements: "
<< mirror::Class::PrettyClass(element->GetClass());
return false;
}
if (!CollectDexFilesFromJavaDexFile(dex_file, cookie_field, out_dex_files)) {
return false;
}
}
return true;
}
// Adds the `class_loader` info to the `context`.
// The dex file present in `dex_elements` array (if not null) will be added at the end of
// the classpath.
// This method is recursive (w.r.t. the class loader parent) and will stop once it reaches the
// BootClassLoader. Note that the class loader chain is expected to be short.
bool ClassLoaderContext::CreateInfoFromClassLoader(
ScopedObjectAccessAlreadyRunnable& soa,
Handle<mirror::ClassLoader> class_loader,
Handle<mirror::ObjectArray<mirror::Object>> dex_elements,
ClassLoaderInfo* child_info,
bool is_shared_library,
bool is_after) REQUIRES_SHARED(Locks::mutator_lock_) {
if (ClassLinker::IsBootClassLoader(class_loader.Get())) {
// Nothing to do for the boot class loader as we don't add its dex files to the context.
return true;
}
ClassLoaderContext::ClassLoaderType type;
if (IsPathOrDexClassLoader(class_loader)) {
type = kPathClassLoader;
} else if (IsDelegateLastClassLoader(class_loader)) {
type = kDelegateLastClassLoader;
} else if (IsInMemoryDexClassLoader(class_loader)) {
type = kInMemoryDexClassLoader;
} else {
LOG(WARNING) << "Unsupported class loader: "
<< mirror::Class::PrettyClass(class_loader->GetClass());
return false;
}
// Inspect the class loader for its dex files.
std::vector<const DexFile*> dex_files_loaded;
CollectDexFilesFromSupportedClassLoader(soa.Self(), class_loader, &dex_files_loaded);
// If we have a dex_elements array extract its dex elements now.
// This is used in two situations:
// 1) when a new ClassLoader is created DexPathList will open each dex file sequentially
// passing the list of already open dex files each time. This ensures that we see the
// correct context even if the ClassLoader under construction is not fully build.
// 2) when apk splits are loaded on the fly, the framework will load their dex files by
// appending them to the current class loader. When the new code paths are loaded in
// BaseDexClassLoader, the paths already present in the class loader will be passed
// in the dex_elements array.
if (dex_elements != nullptr) {
GetDexFilesFromDexElementsArray(dex_elements, &dex_files_loaded);
}
ClassLoaderInfo* info = new ClassLoaderContext::ClassLoaderInfo(type);
// Attach the `ClassLoaderInfo` now, before populating dex files, as only the
// `ClassLoaderContext` knows whether these dex files should be deleted or not.
if (child_info == nullptr) {
class_loader_chain_.reset(info);
} else if (is_shared_library) {
if (is_after) {
child_info->shared_libraries_after.push_back(std::unique_ptr<ClassLoaderInfo>(info));
} else {
child_info->shared_libraries.push_back(std::unique_ptr<ClassLoaderInfo>(info));
}
} else {
child_info->parent.reset(info);
}
// Now that `info` is in the chain, populate dex files.
for (size_t i = 0; i < dex_files_loaded.size();) {
const DexFile* dex_file = dex_files_loaded[i];
uint32_t checksum = DexFileLoader::GetMultiDexChecksum(dex_files_loaded, &i);
// Dex location of dex files loaded with InMemoryDexClassLoader is always bogus.
// Use a magic value for the classpath instead.
info->classpath.push_back((type == kInMemoryDexClassLoader) ?
kInMemoryDexClassLoaderDexLocationMagic :
dex_file->GetLocation());
info->checksums.push_back(checksum);
}
for (auto* dex_file : dex_files_loaded) {
info->opened_dex_files.emplace_back(dex_file);
}
// Note that dex_elements array is null here. The elements are considered to be part of the
// current class loader and are not passed to the parents.
ScopedNullHandle<mirror::ObjectArray<mirror::Object>> null_dex_elements;
// Add the shared libraries.
StackHandleScope<5> hs(Thread::Current());
ArtField* field = WellKnownClasses::dalvik_system_BaseDexClassLoader_sharedLibraryLoaders;
ObjPtr<mirror::Object> raw_shared_libraries = field->GetObject(class_loader.Get());
if (raw_shared_libraries != nullptr) {
Handle<mirror::ObjectArray<mirror::ClassLoader>> shared_libraries =
hs.NewHandle(raw_shared_libraries->AsObjectArray<mirror::ClassLoader>());
MutableHandle<mirror::ClassLoader> temp_loader = hs.NewHandle<mirror::ClassLoader>(nullptr);
for (auto library : shared_libraries.Iterate<mirror::ClassLoader>()) {
temp_loader.Assign(library);
if (!CreateInfoFromClassLoader(soa,
temp_loader,
null_dex_elements,
info,
/*is_shared_library=*/true,
/*is_after=*/false)) {
return false;
}
}
}
ArtField* field2 = WellKnownClasses::dalvik_system_BaseDexClassLoader_sharedLibraryLoadersAfter;
ObjPtr<mirror::Object> raw_shared_libraries_after = field2->GetObject(class_loader.Get());
if (raw_shared_libraries_after != nullptr) {
Handle<mirror::ObjectArray<mirror::ClassLoader>> shared_libraries_after =
hs.NewHandle(raw_shared_libraries_after->AsObjectArray<mirror::ClassLoader>());
MutableHandle<mirror::ClassLoader> temp_loader = hs.NewHandle<mirror::ClassLoader>(nullptr);
for (auto library : shared_libraries_after.Iterate<mirror::ClassLoader>()) {
temp_loader.Assign(library);
if (!CreateInfoFromClassLoader(soa,
temp_loader,
null_dex_elements,
info,
/*is_shared_library=*/true,
/*is_after=*/true)) {
return false;
}
}
}
// We created the ClassLoaderInfo for the current loader. Move on to its parent.
Handle<mirror::ClassLoader> parent = hs.NewHandle(class_loader->GetParent());
if (!CreateInfoFromClassLoader(soa,
parent,
null_dex_elements,
info,
/*is_shared_library=*/false,
/*is_after=*/false)) {
return false;
}
return true;
}
std::unique_ptr<ClassLoaderContext> ClassLoaderContext::CreateContextForClassLoader(
jobject class_loader, jobjectArray dex_elements) {
ScopedTrace trace(__FUNCTION__);
if (class_loader == nullptr) {
return nullptr;
}
ScopedObjectAccess soa(Thread::Current());
StackHandleScope<2> hs(soa.Self());
Handle<mirror::ClassLoader> h_class_loader =
hs.NewHandle(soa.Decode<mirror::ClassLoader>(class_loader));
Handle<mirror::ObjectArray<mirror::Object>> h_dex_elements =
hs.NewHandle(soa.Decode<mirror::ObjectArray<mirror::Object>>(dex_elements));
std::unique_ptr<ClassLoaderContext> result(new ClassLoaderContext(/*owns_the_dex_files=*/false));
if (!result->CreateInfoFromClassLoader(soa,
h_class_loader,
h_dex_elements,
nullptr,
/*is_shared_library=*/false,
/*is_after=*/false)) {
return nullptr;
}
return result;
}
std::map<std::string, std::string> ClassLoaderContext::EncodeClassPathContextsForClassLoader(
jobject class_loader) {
std::unique_ptr<ClassLoaderContext> clc =
ClassLoaderContext::CreateContextForClassLoader(class_loader, nullptr);
if (clc != nullptr) {
return clc->EncodeClassPathContexts("");
}
ScopedObjectAccess soa(Thread::Current());
StackHandleScope<1> hs(soa.Self());
Handle<mirror::ClassLoader> h_class_loader =
hs.NewHandle(soa.Decode<mirror::ClassLoader>(class_loader));
if (!IsInstanceOfBaseDexClassLoader(h_class_loader)) {
return std::map<std::string, std::string>{};
}
std::vector<const DexFile*> dex_files_loaded;
CollectDexFilesFromSupportedClassLoader(soa.Self(), h_class_loader, &dex_files_loaded);
std::map<std::string, std::string> results;
for (const DexFile* dex_file : dex_files_loaded) {
results.emplace(DexFileLoader::GetBaseLocation(dex_file->GetLocation()),
ClassLoaderContext::kUnsupportedClassLoaderContextEncoding);
}
return results;
}
bool ClassLoaderContext::IsValidEncoding(const std::string& possible_encoded_class_loader_context) {
return ClassLoaderContext::Create(possible_encoded_class_loader_context) != nullptr ||
possible_encoded_class_loader_context == kUnsupportedClassLoaderContextEncoding;
}
ClassLoaderContext::VerificationResult ClassLoaderContext::VerifyClassLoaderContextMatch(
const std::string& context_spec, bool verify_names, bool verify_checksums) const {
ScopedTrace trace(__FUNCTION__);
if (verify_names || verify_checksums) {
DCHECK(dex_files_state_ == kDexFilesChecksumsRead || dex_files_state_ == kDexFilesOpened)
<< "dex_files_state_=" << dex_files_state_;
}
ClassLoaderContext expected_context;
if (!expected_context.Parse(context_spec, verify_checksums)) {
LOG(WARNING) << "Invalid class loader context: " << context_spec;
return VerificationResult::kMismatch;
}
ClassLoaderInfo* info = class_loader_chain_.get();
ClassLoaderInfo* expected = expected_context.class_loader_chain_.get();
CHECK(info != nullptr);
CHECK(expected != nullptr);
if (!ClassLoaderInfoMatch(*info, *expected, context_spec, verify_names, verify_checksums)) {
return VerificationResult::kMismatch;
}
return VerificationResult::kVerifies;
}
// Returns true if absolute `path` ends with relative `suffix` starting at
// a directory name boundary, i.e. after a '/'. For example, "foo/bar"
// is a valid suffix of "/data/foo/bar" but not "/data-foo/bar".
static inline bool AbsolutePathHasRelativeSuffix(const std::string& path,
const std::string& suffix) {
DCHECK(IsAbsoluteLocation(path));
DCHECK(!IsAbsoluteLocation(suffix));
return (path.size() > suffix.size()) && (path[path.size() - suffix.size() - 1u] == '/') &&
(std::string_view(path).substr(/*pos*/ path.size() - suffix.size()) == suffix);
}
// Resolves symlinks and returns the canonicalized absolute path. Returns relative path as is.
static std::string ResolveIfAbsolutePath(const std::string& path) {
if (!IsAbsoluteLocation(path)) {
return path;
}
std::string filename = path;
std::string multi_dex_suffix;
size_t pos = filename.find(DexFileLoader::kMultiDexSeparator);
if (pos != std::string::npos) {
multi_dex_suffix = filename.substr(pos);
filename.resize(pos);
}
std::string resolved_filename;
if (!android::base::Realpath(filename, &resolved_filename)) {
PLOG(ERROR) << "Unable to resolve path '" << path << "'";
return path;
}
return resolved_filename + multi_dex_suffix;
}
// Returns true if the given dex names are mathing, false otherwise.
static bool AreDexNameMatching(const std::string& actual_dex_name,
const std::string& expected_dex_name) {
// Compute the dex location that must be compared.
// We shouldn't do a naive comparison `actual_dex_name == expected_dex_name`
// because even if they refer to the same file, one could be encoded as a relative location
// and the other as an absolute one.
bool is_dex_name_absolute = IsAbsoluteLocation(actual_dex_name);
bool is_expected_dex_name_absolute = IsAbsoluteLocation(expected_dex_name);
bool dex_names_match = false;
std::string resolved_actual_dex_name = ResolveIfAbsolutePath(actual_dex_name);
std::string resolved_expected_dex_name = ResolveIfAbsolutePath(expected_dex_name);
if (is_dex_name_absolute == is_expected_dex_name_absolute) {
// If both locations are absolute or relative then compare them as they are.
// This is usually the case for: shared libraries and secondary dex files.
dex_names_match = (resolved_actual_dex_name == resolved_expected_dex_name);
} else if (is_dex_name_absolute) {
// The runtime name is absolute but the compiled name (the expected one) is relative.
// This is the case for split apks which depend on base or on other splits.
dex_names_match =
AbsolutePathHasRelativeSuffix(resolved_actual_dex_name, resolved_expected_dex_name);
} else if (is_expected_dex_name_absolute) {
// The runtime name is relative but the compiled name is absolute.
// There is no expected use case that would end up here as dex files are always loaded
// with their absolute location. However, be tolerant and do the best effort (in case
// there are unexpected new use case...).
dex_names_match =
AbsolutePathHasRelativeSuffix(resolved_expected_dex_name, resolved_actual_dex_name);
} else {
// Both locations are relative. In this case there's not much we can be sure about
// except that the names are the same. The checksum will ensure that the files are
// are same. This should not happen outside testing and manual invocations.
dex_names_match = (resolved_actual_dex_name == resolved_expected_dex_name);
}
return dex_names_match;
}
bool ClassLoaderContext::ClassLoaderInfoMatch(const ClassLoaderInfo& info,
const ClassLoaderInfo& expected_info,
const std::string& context_spec,
bool verify_names,
bool verify_checksums) const {
if (info.type != expected_info.type) {
LOG(WARNING) << "ClassLoaderContext type mismatch"
<< ". expected=" << GetClassLoaderTypeName(expected_info.type)
<< ", found=" << GetClassLoaderTypeName(info.type) << " (" << context_spec << " | "
<< EncodeContextForOatFile("") << ")";
return false;
}
if (info.classpath.size() != expected_info.classpath.size()) {
LOG(WARNING) << "ClassLoaderContext classpath size mismatch"
<< ". expected=" << expected_info.classpath.size()
<< ", found=" << info.classpath.size() << " (" << context_spec << " | "
<< EncodeContextForOatFile("") << ")";
return false;
}
if (verify_checksums) {
DCHECK_EQ(info.classpath.size(), info.checksums.size());
DCHECK_EQ(expected_info.classpath.size(), expected_info.checksums.size());
}
if (verify_names) {
for (size_t k = 0; k < info.classpath.size(); k++) {
bool dex_names_match = AreDexNameMatching(info.classpath[k], expected_info.classpath[k]);
// Compare the locations.
if (!dex_names_match) {
LOG(WARNING) << "ClassLoaderContext classpath element mismatch"
<< ". expected=" << expected_info.classpath[k]
<< ", found=" << info.classpath[k] << " (" << context_spec << " | "
<< EncodeContextForOatFile("") << ")";
return false;
}
// Compare the checksums.
if (info.checksums[k] != expected_info.checksums[k]) {
LOG(WARNING) << "ClassLoaderContext classpath element checksum mismatch"
<< ". expected=" << expected_info.checksums[k]
<< ", found=" << info.checksums[k] << " (" << context_spec << " | "
<< EncodeContextForOatFile("") << ")";
return false;
}
}
}
if (info.shared_libraries.size() != expected_info.shared_libraries.size()) {
LOG(WARNING) << "ClassLoaderContext shared library size mismatch. "
<< "Expected=" << expected_info.shared_libraries.size()
<< ", found=" << info.shared_libraries.size() << " (" << context_spec << " | "
<< EncodeContextForOatFile("") << ")";
return false;
}
for (size_t i = 0; i < info.shared_libraries.size(); ++i) {
if (!ClassLoaderInfoMatch(*info.shared_libraries[i].get(),
*expected_info.shared_libraries[i].get(),
context_spec,
verify_names,
verify_checksums)) {
return false;
}
}
if (info.parent.get() == nullptr) {
if (expected_info.parent.get() != nullptr) {
LOG(WARNING) << "ClassLoaderContext parent mismatch. "
<< " (" << context_spec << " | " << EncodeContextForOatFile("") << ")";
return false;
}
return true;
} else if (expected_info.parent.get() == nullptr) {
LOG(WARNING) << "ClassLoaderContext parent mismatch. "
<< " (" << context_spec << " | " << EncodeContextForOatFile("") << ")";
return false;
} else {
return ClassLoaderInfoMatch(*info.parent.get(),
*expected_info.parent.get(),
context_spec,
verify_names,
verify_checksums);
}
}
std::set<const DexFile*> ClassLoaderContext::CheckForDuplicateDexFiles(
const std::vector<const DexFile*>& dex_files_to_check) {
DCHECK_EQ(dex_files_state_, kDexFilesOpened);
std::set<const DexFile*> result;
// If the chain is null there's nothing we can check, return an empty list.
// The class loader chain can be null if there were issues when creating the
// class loader context (e.g. tests).
if (class_loader_chain_ == nullptr) {
return result;
}
// We only check the current Class Loader which the first one in the chain.
// Cross class-loader duplicates may be a valid scenario (though unlikely
// in the Android world) - and as such we decide not to warn on them.
ClassLoaderInfo* info = class_loader_chain_.get();
for (size_t k = 0; k < info->classpath.size(); k++) {
for (size_t i = 0; i < dex_files_to_check.size();) {
const DexFile* dex_file = dex_files_to_check[i];
uint32_t checksum = DexFileLoader::GetMultiDexChecksum(dex_files_to_check, &i);
if (info->checksums[k] == checksum &&
AreDexNameMatching(info->classpath[k], dex_file->GetLocation())) {
result.insert(dex_file);
}
}
}
return result;
}
} // namespace art