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review.shift-gmbh.com / SHIFTPHONES / android_art / d0430bfe6e08f932fa15b159457a5430f5b3ec25 / . / imgdiag / imgdiag.cc
blob: f3982ec342fa3a5ece0f35106034748ba8a7a998 [file] [log] [blame]
/*
* Copyright (C) 2014 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <stdio.h>
#include <stdlib.h>
#include <fstream>
#include <functional>
#include <iostream>
#include <map>
#include <optional>
#include <set>
#include <string>
#include <unordered_set>
#include <vector>
#include <android-base/parseint.h>
#include "android-base/stringprintf.h"
#include "art_field-inl.h"
#include "art_method-inl.h"
#include "base/array_ref.h"
#include "base/os.h"
#include "base/string_view_cpp20.h"
#include "base/unix_file/fd_file.h"
#include "class_linker.h"
#include "gc/heap.h"
#include "gc/space/image_space.h"
#include "image-inl.h"
#include "mirror/class-inl.h"
#include "mirror/object-inl.h"
#include "oat.h"
#include "oat_file.h"
#include "oat_file_manager.h"
#include "scoped_thread_state_change-inl.h"
#include "backtrace/BacktraceMap.h"
#include "cmdline.h"
#include <signal.h>
#include <sys/stat.h>
#include <sys/types.h>
namespace art {
using android::base::StringPrintf;
namespace {
constexpr size_t kMaxAddressPrint = 5;
enum class ProcessType {
kZygote,
kRemote
};
enum class RemoteProcesses {
kImageOnly,
kZygoteOnly,
kImageAndZygote
};
struct MappingData {
// The count of pages that are considered dirty by the OS.
size_t dirty_pages = 0;
// The count of pages that differ by at least one byte.
size_t different_pages = 0;
// The count of differing bytes.
size_t different_bytes = 0;
// The count of differing four-byte units.
size_t different_int32s = 0;
// The count of pages that have mapping count == 1.
size_t private_pages = 0;
// The count of private pages that are also dirty.
size_t private_dirty_pages = 0;
// The count of pages that are marked dirty but do not differ.
size_t false_dirty_pages = 0;
// Set of the local virtual page indices that are dirty.
std::set<size_t> dirty_page_set;
};
static std::string GetClassDescriptor(mirror::Class* klass)
REQUIRES_SHARED(Locks::mutator_lock_) {
CHECK(klass != nullptr);
std::string descriptor;
const char* descriptor_str = klass->GetDescriptor(&descriptor /*out*/);
return std::string(descriptor_str);
}
static std::string PrettyFieldValue(ArtField* field, mirror::Object* object)
REQUIRES_SHARED(Locks::mutator_lock_) {
std::ostringstream oss;
switch (field->GetTypeAsPrimitiveType()) {
case Primitive::kPrimNot: {
oss << object->GetFieldObject<mirror::Object, kVerifyNone, kWithoutReadBarrier>(
field->GetOffset());
break;
}
case Primitive::kPrimBoolean: {
oss << static_cast<bool>(object->GetFieldBoolean<kVerifyNone>(field->GetOffset()));
break;
}
case Primitive::kPrimByte: {
oss << static_cast<int32_t>(object->GetFieldByte<kVerifyNone>(field->GetOffset()));
break;
}
case Primitive::kPrimChar: {
oss << object->GetFieldChar<kVerifyNone>(field->GetOffset());
break;
}
case Primitive::kPrimShort: {
oss << object->GetFieldShort<kVerifyNone>(field->GetOffset());
break;
}
case Primitive::kPrimInt: {
oss << object->GetField32<kVerifyNone>(field->GetOffset());
break;
}
case Primitive::kPrimLong: {
oss << object->GetField64<kVerifyNone>(field->GetOffset());
break;
}
case Primitive::kPrimFloat: {
oss << object->GetField32<kVerifyNone>(field->GetOffset());
break;
}
case Primitive::kPrimDouble: {
oss << object->GetField64<kVerifyNone>(field->GetOffset());
break;
}
case Primitive::kPrimVoid: {
oss << "void";
break;
}
}
return oss.str();
}
template <typename K, typename V, typename D>
static std::vector<std::pair<V, K>> SortByValueDesc(
const std::map<K, D> map,
std::function<V(const D&)> value_mapper = [](const D& d) { return static_cast<V>(d); }) {
// Store value->key so that we can use the default sort from pair which
// sorts by value first and then key
std::vector<std::pair<V, K>> value_key_vector;
for (const auto& kv_pair : map) {
value_key_vector.push_back(std::make_pair(value_mapper(kv_pair.second), kv_pair.first));
}
// Sort in reverse (descending order)
std::sort(value_key_vector.rbegin(), value_key_vector.rend());
return value_key_vector;
}
// Fixup a remote pointer that we read from a foreign boot.art to point to our own memory.
// Returned pointer will point to inside of remote_contents.
template <typename T>
static ObjPtr<T> FixUpRemotePointer(ObjPtr<T> remote_ptr,
std::vector<uint8_t>& remote_contents,
const backtrace_map_t& boot_map)
REQUIRES_SHARED(Locks::mutator_lock_) {
if (remote_ptr == nullptr) {
return nullptr;
}
uintptr_t remote = reinterpret_cast<uintptr_t>(remote_ptr.Ptr());
// In the case the remote pointer is out of range, it probably belongs to another image.
// Just return null for this case.
if (remote < boot_map.start || remote >= boot_map.end) {
return nullptr;
}
off_t boot_offset = remote - boot_map.start;
return reinterpret_cast<T*>(&remote_contents[boot_offset]);
}
template <typename T>
static ObjPtr<T> RemoteContentsPointerToLocal(ObjPtr<T> remote_ptr,
std::vector<uint8_t>& remote_contents,
const ImageHeader& image_header)
REQUIRES_SHARED(Locks::mutator_lock_) {
if (remote_ptr == nullptr) {
return nullptr;
}
uint8_t* remote = reinterpret_cast<uint8_t*>(remote_ptr.Ptr());
ptrdiff_t boot_offset = remote - &remote_contents[0];
const uint8_t* local_ptr = reinterpret_cast<const uint8_t*>(&image_header) + boot_offset;
return reinterpret_cast<T*>(const_cast<uint8_t*>(local_ptr));
}
template <typename T> size_t EntrySize(T* entry);
template<> size_t EntrySize(mirror::Object* object) REQUIRES_SHARED(Locks::mutator_lock_) {
return object->SizeOf();
}
template<> size_t EntrySize(ArtMethod* art_method) REQUIRES_SHARED(Locks::mutator_lock_) {
return sizeof(*art_method);
}
template <typename T>
static bool EntriesDiffer(T* entry1, T* entry2) REQUIRES_SHARED(Locks::mutator_lock_) {
return memcmp(entry1, entry2, EntrySize(entry1)) != 0;
}
template <typename T>
struct RegionCommon {
public:
RegionCommon(std::ostream* os,
std::vector<uint8_t>* remote_contents,
std::vector<uint8_t>* zygote_contents,
const backtrace_map_t& boot_map,
const ImageHeader& image_header) :
os_(*os),
remote_contents_(remote_contents),
zygote_contents_(zygote_contents),
boot_map_(boot_map),
image_header_(image_header),
different_entries_(0),
dirty_entry_bytes_(0),
false_dirty_entry_bytes_(0) {
CHECK(remote_contents != nullptr);
CHECK(zygote_contents != nullptr);
}
void DumpSamplesAndOffsetCount() {
os_ << " sample object addresses: ";
for (size_t i = 0; i < dirty_entries_.size() && i < kMaxAddressPrint; ++i) {
T* entry = dirty_entries_[i];
os_ << reinterpret_cast<void*>(entry) << ", ";
}
os_ << "\n";
os_ << " dirty byte +offset:count list = ";
std::vector<std::pair<size_t, off_t>> field_dirty_count_sorted =
SortByValueDesc<off_t, size_t, size_t>(field_dirty_count_);
for (const std::pair<size_t, off_t>& pair : field_dirty_count_sorted) {
off_t offset = pair.second;
size_t count = pair.first;
os_ << "+" << offset << ":" << count << ", ";
}
os_ << "\n";
}
size_t GetDifferentEntryCount() const { return different_entries_; }
size_t GetDirtyEntryBytes() const { return dirty_entry_bytes_; }
size_t GetFalseDirtyEntryCount() const { return false_dirty_entries_.size(); }
size_t GetFalseDirtyEntryBytes() const { return false_dirty_entry_bytes_; }
size_t GetZygoteDirtyEntryCount() const { return zygote_dirty_entries_.size(); }
protected:
bool IsEntryOnDirtyPage(T* entry, const std::set<size_t>& dirty_pages) const
REQUIRES_SHARED(Locks::mutator_lock_) {
size_t size = EntrySize(entry);
size_t page_off = 0;
size_t current_page_idx;
uintptr_t entry_address = reinterpret_cast<uintptr_t>(entry);
// Iterate every page this entry belongs to
do {
current_page_idx = entry_address / kPageSize + page_off;
if (dirty_pages.find(current_page_idx) != dirty_pages.end()) {
// This entry is on a dirty page
return true;
}
page_off++;
} while ((current_page_idx * kPageSize) < RoundUp(entry_address + size, kObjectAlignment));
return false;
}
void AddZygoteDirtyEntry(T* entry) REQUIRES_SHARED(Locks::mutator_lock_) {
zygote_dirty_entries_.insert(entry);
}
void AddImageDirtyEntry(T* entry) REQUIRES_SHARED(Locks::mutator_lock_) {
image_dirty_entries_.insert(entry);
}
void AddFalseDirtyEntry(T* entry) REQUIRES_SHARED(Locks::mutator_lock_) {
false_dirty_entries_.push_back(entry);
false_dirty_entry_bytes_ += EntrySize(entry);
}
// The output stream to write to.
std::ostream& os_;
// The byte contents of the remote (image) process' image.
std::vector<uint8_t>* remote_contents_;
// The byte contents of the zygote process' image.
std::vector<uint8_t>* zygote_contents_;
const backtrace_map_t& boot_map_;
const ImageHeader& image_header_;
// Count of entries that are different.
size_t different_entries_;
// Local entries that are dirty (differ in at least one byte).
size_t dirty_entry_bytes_;
std::vector<T*> dirty_entries_;
// Local entries that are clean, but located on dirty pages.
size_t false_dirty_entry_bytes_;
std::vector<T*> false_dirty_entries_;
// Image dirty entries
// If zygote_pid_only_ == true, these are shared dirty entries in the zygote.
// If zygote_pid_only_ == false, these are private dirty entries in the application.
std::set<T*> image_dirty_entries_;
// Zygote dirty entries (probably private dirty).
// We only add entries here if they differed in both the image and the zygote, so
// they are probably private dirty.
std::set<T*> zygote_dirty_entries_;
std::map<off_t /* field offset */, size_t /* count */> field_dirty_count_;
private:
DISALLOW_COPY_AND_ASSIGN(RegionCommon);
};
template <typename T>
class RegionSpecializedBase : public RegionCommon<T> {
};
// Region analysis for mirror::Objects
class ImgObjectVisitor : public ObjectVisitor {
public:
using ComputeDirtyFunc = std::function<void(mirror::Object* object,
const uint8_t* begin_image_ptr,
const std::set<size_t>& dirty_pages)>;
ImgObjectVisitor(ComputeDirtyFunc dirty_func,
const uint8_t* begin_image_ptr,
const std::set<size_t>& dirty_pages) :
dirty_func_(std::move(dirty_func)),
begin_image_ptr_(begin_image_ptr),
dirty_pages_(dirty_pages) { }
~ImgObjectVisitor() override { }
void Visit(mirror::Object* object) override REQUIRES_SHARED(Locks::mutator_lock_) {
// Sanity check that we are reading a real mirror::Object
CHECK(object->GetClass() != nullptr) << "Image object at address "
<< object
<< " has null class";
if (kUseBakerReadBarrier) {
object->AssertReadBarrierState();
}
dirty_func_(object, begin_image_ptr_, dirty_pages_);
}
private:
const ComputeDirtyFunc dirty_func_;
const uint8_t* begin_image_ptr_;
const std::set<size_t>& dirty_pages_;
};
template<>
class RegionSpecializedBase<mirror::Object> : public RegionCommon<mirror::Object> {
public:
RegionSpecializedBase(std::ostream* os,
std::vector<uint8_t>* remote_contents,
std::vector<uint8_t>* zygote_contents,
const backtrace_map_t& boot_map,
const ImageHeader& image_header,
bool dump_dirty_objects)
: RegionCommon<mirror::Object>(os, remote_contents, zygote_contents, boot_map, image_header),
os_(*os),
dump_dirty_objects_(dump_dirty_objects) { }
// Define a common public type name for use by RegionData.
using VisitorClass = ImgObjectVisitor;
void VisitEntries(VisitorClass* visitor,
uint8_t* base,
PointerSize pointer_size)
REQUIRES_SHARED(Locks::mutator_lock_) {
RegionCommon<mirror::Object>::image_header_.VisitObjects(visitor, base, pointer_size);
}
void VisitEntry(mirror::Object* entry)
REQUIRES_SHARED(Locks::mutator_lock_) {
// Unconditionally store the class descriptor in case we need it later
mirror::Class* klass = entry->GetClass();
class_data_[klass].descriptor = GetClassDescriptor(klass);
}
void AddCleanEntry(mirror::Object* entry)
REQUIRES_SHARED(Locks::mutator_lock_) {
class_data_[entry->GetClass()].AddCleanObject();
}
void AddFalseDirtyEntry(mirror::Object* entry)
REQUIRES_SHARED(Locks::mutator_lock_) {
RegionCommon<mirror::Object>::AddFalseDirtyEntry(entry);
class_data_[entry->GetClass()].AddFalseDirtyObject(entry);
}
void AddDirtyEntry(mirror::Object* entry, mirror::Object* entry_remote)
REQUIRES_SHARED(Locks::mutator_lock_) {
size_t entry_size = EntrySize(entry);
++different_entries_;
dirty_entry_bytes_ += entry_size;
// Log dirty count and objects for class objects only.
mirror::Class* klass = entry->GetClass();
if (klass->IsClassClass()) {
// Increment counts for the fields that are dirty
const uint8_t* current = reinterpret_cast<const uint8_t*>(entry);
const uint8_t* current_remote = reinterpret_cast<const uint8_t*>(entry_remote);
for (size_t i = 0; i < entry_size; ++i) {
if (current[i] != current_remote[i]) {
field_dirty_count_[i]++;
}
}
dirty_entries_.push_back(entry);
}
class_data_[klass].AddDirtyObject(entry, entry_remote);
}
void DiffEntryContents(mirror::Object* entry,
uint8_t* remote_bytes,
const uint8_t* base_ptr,
bool log_dirty_objects)
REQUIRES_SHARED(Locks::mutator_lock_) {
const char* tabs = " ";
// Attempt to find fields for all dirty bytes.
mirror::Class* klass = entry->GetClass();
if (entry->IsClass()) {
os_ << tabs
<< "Class " << mirror::Class::PrettyClass(entry->AsClass()) << " " << entry << "\n";
} else {
os_ << tabs
<< "Instance of " << mirror::Class::PrettyClass(klass) << " " << entry << "\n";
}
std::unordered_set<ArtField*> dirty_instance_fields;
std::unordered_set<ArtField*> dirty_static_fields;
// Examine the bytes comprising the Object, computing which fields are dirty
// and recording them for later display. If the Object is an array object,
// compute the dirty entries.
mirror::Object* remote_entry = reinterpret_cast<mirror::Object*>(remote_bytes);
for (size_t i = 0, count = entry->SizeOf(); i < count; ++i) {
if (base_ptr[i] != remote_bytes[i]) {
ArtField* field = ArtField::FindInstanceFieldWithOffset</*exact*/false>(klass, i);
if (field != nullptr) {
dirty_instance_fields.insert(field);
} else if (entry->IsClass()) {
field = ArtField::FindStaticFieldWithOffset</*exact*/false>(entry->AsClass(), i);
if (field != nullptr) {
dirty_static_fields.insert(field);
}
}
if (field == nullptr) {
if (klass->IsArrayClass()) {
mirror::Class* component_type = klass->GetComponentType();
Primitive::Type primitive_type = component_type->GetPrimitiveType();
size_t component_size = Primitive::ComponentSize(primitive_type);
size_t data_offset = mirror::Array::DataOffset(component_size).Uint32Value();
DCHECK_ALIGNED_PARAM(data_offset, component_size);
if (i >= data_offset) {
os_ << tabs << "Dirty array element " << (i - data_offset) / component_size << "\n";
// Skip the remaining bytes of this element to prevent spam.
DCHECK(IsPowerOfTwo(component_size));
i |= component_size - 1;
continue;
}
}
os_ << tabs << "No field for byte offset " << i << "\n";
}
}
}
// Dump different fields.
if (!dirty_instance_fields.empty()) {
os_ << tabs << "Dirty instance fields " << dirty_instance_fields.size() << "\n";
for (ArtField* field : dirty_instance_fields) {
os_ << tabs << ArtField::PrettyField(field)
<< " original=" << PrettyFieldValue(field, entry)
<< " remote=" << PrettyFieldValue(field, remote_entry) << "\n";
}
}
if (!dirty_static_fields.empty()) {
if (dump_dirty_objects_ && log_dirty_objects) {
dirty_objects_.insert(entry);
}
os_ << tabs << "Dirty static fields " << dirty_static_fields.size() << "\n";
for (ArtField* field : dirty_static_fields) {
os_ << tabs << ArtField::PrettyField(field)
<< " original=" << PrettyFieldValue(field, entry)
<< " remote=" << PrettyFieldValue(field, remote_entry) << "\n";
}
}
os_ << "\n";
}
void DumpDirtyObjects() REQUIRES_SHARED(Locks::mutator_lock_) {
for (mirror::Object* obj : dirty_objects_) {
if (obj->IsClass()) {
os_ << "Private dirty object: " << obj->AsClass()->PrettyDescriptor() << "\n";
}
}
}
void DumpDirtyEntries() REQUIRES_SHARED(Locks::mutator_lock_) {
// vector of pairs (size_t count, Class*)
auto dirty_object_class_values =
SortByValueDesc<mirror::Class*, size_t, ClassData>(
class_data_,
[](const ClassData& d) { return d.dirty_object_count; });
os_ << "\n" << " Dirty object count by class:\n";
for (const auto& vk_pair : dirty_object_class_values) {
size_t dirty_object_count = vk_pair.first;
mirror::Class* klass = vk_pair.second;
ClassData& class_data = class_data_[klass];
size_t object_sizes = class_data.dirty_object_size_in_bytes;
float avg_dirty_bytes_per_class =
class_data.dirty_object_byte_count * 1.0f / object_sizes;
float avg_object_size = object_sizes * 1.0f / dirty_object_count;
const std::string& descriptor = class_data.descriptor;
os_ << " " << mirror::Class::PrettyClass(klass) << " ("
<< "objects: " << dirty_object_count << ", "
<< "avg dirty bytes: " << avg_dirty_bytes_per_class << ", "
<< "avg object size: " << avg_object_size << ", "
<< "class descriptor: '" << descriptor << "'"
<< ")\n";
if (strcmp(descriptor.c_str(), "Ljava/lang/Class;") == 0) {
DumpSamplesAndOffsetCount();
os_ << " field contents:\n";
for (mirror::Object* object : class_data.dirty_objects) {
// remote class object
ObjPtr<mirror::Class> remote_klass =
ObjPtr<mirror::Class>::DownCast<mirror::Object>(object);
// local class object
ObjPtr<mirror::Class> local_klass =
RemoteContentsPointerToLocal(remote_klass,
*RegionCommon<mirror::Object>::remote_contents_,
RegionCommon<mirror::Object>::image_header_);
os_ << " " << reinterpret_cast<const void*>(object) << " ";
os_ << " class_status (remote): " << remote_klass->GetStatus() << ", ";
os_ << " class_status (local): " << local_klass->GetStatus();
os_ << "\n";
}
}
}
}
void DumpFalseDirtyEntries() REQUIRES_SHARED(Locks::mutator_lock_) {
// vector of pairs (size_t count, Class*)
auto false_dirty_object_class_values =
SortByValueDesc<mirror::Class*, size_t, ClassData>(
class_data_,
[](const ClassData& d) { return d.false_dirty_object_count; });
os_ << "\n" << " False-dirty object count by class:\n";
for (const auto& vk_pair : false_dirty_object_class_values) {
size_t object_count = vk_pair.first;
mirror::Class* klass = vk_pair.second;
ClassData& class_data = class_data_[klass];
size_t object_sizes = class_data.false_dirty_byte_count;
float avg_object_size = object_sizes * 1.0f / object_count;
const std::string& descriptor = class_data.descriptor;
os_ << " " << mirror::Class::PrettyClass(klass) << " ("
<< "objects: " << object_count << ", "
<< "avg object size: " << avg_object_size << ", "
<< "total bytes: " << object_sizes << ", "
<< "class descriptor: '" << descriptor << "'"
<< ")\n";
}
}
void DumpCleanEntries() REQUIRES_SHARED(Locks::mutator_lock_) {
// vector of pairs (size_t count, Class*)
auto clean_object_class_values =
SortByValueDesc<mirror::Class*, size_t, ClassData>(
class_data_,
[](const ClassData& d) { return d.clean_object_count; });
os_ << "\n" << " Clean object count by class:\n";
for (const auto& vk_pair : clean_object_class_values) {
os_ << " " << mirror::Class::PrettyClass(vk_pair.second) << " (" << vk_pair.first << ")\n";
}
}
private:
// Aggregate and detail class data from an image diff.
struct ClassData {
size_t dirty_object_count = 0;
// Track only the byte-per-byte dirtiness (in bytes)
size_t dirty_object_byte_count = 0;
// Track the object-by-object dirtiness (in bytes)
size_t dirty_object_size_in_bytes = 0;
size_t clean_object_count = 0;
std::string descriptor;
size_t false_dirty_byte_count = 0;
size_t false_dirty_object_count = 0;
std::vector<mirror::Object*> false_dirty_objects;
// Remote pointers to dirty objects
std::vector<mirror::Object*> dirty_objects;
void AddCleanObject() REQUIRES_SHARED(Locks::mutator_lock_) {
++clean_object_count;
}
void AddDirtyObject(mirror::Object* object, mirror::Object* object_remote)
REQUIRES_SHARED(Locks::mutator_lock_) {
++dirty_object_count;
dirty_object_byte_count += CountDirtyBytes(object, object_remote);
dirty_object_size_in_bytes += EntrySize(object);
dirty_objects.push_back(object_remote);
}
void AddFalseDirtyObject(mirror::Object* object) REQUIRES_SHARED(Locks::mutator_lock_) {
++false_dirty_object_count;
false_dirty_objects.push_back(object);
false_dirty_byte_count += EntrySize(object);
}
private:
// Go byte-by-byte and figure out what exactly got dirtied
static size_t CountDirtyBytes(mirror::Object* object1, mirror::Object* object2)
REQUIRES_SHARED(Locks::mutator_lock_) {
const uint8_t* cur1 = reinterpret_cast<const uint8_t*>(object1);
const uint8_t* cur2 = reinterpret_cast<const uint8_t*>(object2);
size_t dirty_bytes = 0;
size_t object_size = EntrySize(object1);
for (size_t i = 0; i < object_size; ++i) {
if (cur1[i] != cur2[i]) {
dirty_bytes++;
}
}
return dirty_bytes;
}
};
std::ostream& os_;
bool dump_dirty_objects_;
std::unordered_set<mirror::Object*> dirty_objects_;
std::map<mirror::Class*, ClassData> class_data_;
DISALLOW_COPY_AND_ASSIGN(RegionSpecializedBase);
};
// Region analysis for ArtMethods.
class ImgArtMethodVisitor : public ArtMethodVisitor {
public:
using ComputeDirtyFunc = std::function<void(ArtMethod*,
const uint8_t*,
const std::set<size_t>&)>;
ImgArtMethodVisitor(ComputeDirtyFunc dirty_func,
const uint8_t* begin_image_ptr,
const std::set<size_t>& dirty_pages) :
dirty_func_(std::move(dirty_func)),
begin_image_ptr_(begin_image_ptr),
dirty_pages_(dirty_pages) { }
~ImgArtMethodVisitor() override { }
void Visit(ArtMethod* method) override {
dirty_func_(method, begin_image_ptr_, dirty_pages_);
}
private:
const ComputeDirtyFunc dirty_func_;
const uint8_t* begin_image_ptr_;
const std::set<size_t>& dirty_pages_;
};
// Struct and functor for computing offsets of members of ArtMethods.
// template <typename RegionType>
struct MemberInfo {
template <typename T>
void operator() (const ArtMethod* method, const T* member_address, const std::string& name) {
// Check that member_address is a pointer inside *method.
DCHECK(reinterpret_cast<uintptr_t>(method) <= reinterpret_cast<uintptr_t>(member_address));
DCHECK(reinterpret_cast<uintptr_t>(member_address) + sizeof(T) <=
reinterpret_cast<uintptr_t>(method) + sizeof(ArtMethod));
size_t offset =
reinterpret_cast<uintptr_t>(member_address) - reinterpret_cast<uintptr_t>(method);
offset_to_name_size_.insert({offset, NameAndSize(sizeof(T), name)});
}
struct NameAndSize {
size_t size_;
std::string name_;
NameAndSize(size_t size, const std::string& name) : size_(size), name_(name) { }
NameAndSize() : size_(0), name_("INVALID") { }
};
std::map<size_t, NameAndSize> offset_to_name_size_;
};
template<>
class RegionSpecializedBase<ArtMethod> : public RegionCommon<ArtMethod> {
public:
RegionSpecializedBase(std::ostream* os,
std::vector<uint8_t>* remote_contents,
std::vector<uint8_t>* zygote_contents,
const backtrace_map_t& boot_map,
const ImageHeader& image_header,
bool dump_dirty_objects ATTRIBUTE_UNUSED)
: RegionCommon<ArtMethod>(os, remote_contents, zygote_contents, boot_map, image_header),
os_(*os) {
// Prepare the table for offset to member lookups.
ArtMethod* art_method = reinterpret_cast<ArtMethod*>(&(*remote_contents)[0]);
art_method->VisitMembers(member_info_);
// Prepare the table for address to symbolic entry point names.
BuildEntryPointNames();
class_linker_ = Runtime::Current()->GetClassLinker();
}
// Define a common public type name for use by RegionData.
using VisitorClass = ImgArtMethodVisitor;
void VisitEntries(VisitorClass* visitor,
uint8_t* base,
PointerSize pointer_size)
REQUIRES_SHARED(Locks::mutator_lock_) {
RegionCommon<ArtMethod>::image_header_.VisitPackedArtMethods(visitor, base, pointer_size);
}
void VisitEntry(ArtMethod* method ATTRIBUTE_UNUSED)
REQUIRES_SHARED(Locks::mutator_lock_) {
}
void AddCleanEntry(ArtMethod* method ATTRIBUTE_UNUSED) {
}
void AddFalseDirtyEntry(ArtMethod* method)
REQUIRES_SHARED(Locks::mutator_lock_) {
RegionCommon<ArtMethod>::AddFalseDirtyEntry(method);
}
void AddDirtyEntry(ArtMethod* method, ArtMethod* method_remote)
REQUIRES_SHARED(Locks::mutator_lock_) {
size_t entry_size = EntrySize(method);
++different_entries_;
dirty_entry_bytes_ += entry_size;
// Increment counts for the fields that are dirty
const uint8_t* current = reinterpret_cast<const uint8_t*>(method);
const uint8_t* current_remote = reinterpret_cast<const uint8_t*>(method_remote);
// ArtMethods always log their dirty count and entries.
for (size_t i = 0; i < entry_size; ++i) {
if (current[i] != current_remote[i]) {
field_dirty_count_[i]++;
}
}
dirty_entries_.push_back(method);
}
void DiffEntryContents(ArtMethod* method,
uint8_t* remote_bytes,
const uint8_t* base_ptr,
bool log_dirty_objects ATTRIBUTE_UNUSED)
REQUIRES_SHARED(Locks::mutator_lock_) {
const char* tabs = " ";
os_ << tabs << "ArtMethod " << ArtMethod::PrettyMethod(method) << "\n";
std::unordered_set<size_t> dirty_members;
// Examine the members comprising the ArtMethod, computing which members are dirty.
for (const std::pair<const size_t,
MemberInfo::NameAndSize>& p : member_info_.offset_to_name_size_) {
const size_t offset = p.first;
if (memcmp(base_ptr + offset, remote_bytes + offset, p.second.size_) != 0) {
dirty_members.insert(p.first);
}
}
// Dump different fields.
if (!dirty_members.empty()) {
os_ << tabs << "Dirty members " << dirty_members.size() << "\n";
for (size_t offset : dirty_members) {
const MemberInfo::NameAndSize& member_info = member_info_.offset_to_name_size_[offset];
os_ << tabs << member_info.name_
<< " original=" << StringFromBytes(base_ptr + offset, member_info.size_)
<< " remote=" << StringFromBytes(remote_bytes + offset, member_info.size_)
<< "\n";
}
}
os_ << "\n";
}
void DumpDirtyObjects() REQUIRES_SHARED(Locks::mutator_lock_) {
}
void DumpDirtyEntries() REQUIRES_SHARED(Locks::mutator_lock_) {
DumpSamplesAndOffsetCount();
os_ << " offset to field map:\n";
for (const std::pair<const size_t,
MemberInfo::NameAndSize>& p : member_info_.offset_to_name_size_) {
const size_t offset = p.first;
const size_t size = p.second.size_;
os_ << StringPrintf(" %zu-%zu: ", offset, offset + size - 1)
<< p.second.name_
<< std::endl;
}
os_ << " field contents:\n";
for (ArtMethod* method : dirty_entries_) {
// remote method
auto art_method = reinterpret_cast<ArtMethod*>(method);
// remote class
ObjPtr<mirror::Class> remote_declaring_class =
FixUpRemotePointer(art_method->GetDeclaringClass(),
*RegionCommon<ArtMethod>::remote_contents_,
RegionCommon<ArtMethod>::boot_map_);
// local class
ObjPtr<mirror::Class> declaring_class =
RemoteContentsPointerToLocal(remote_declaring_class,
*RegionCommon<ArtMethod>::remote_contents_,
RegionCommon<ArtMethod>::image_header_);
DumpOneArtMethod(art_method, declaring_class, remote_declaring_class);
}
}
void DumpFalseDirtyEntries() REQUIRES_SHARED(Locks::mutator_lock_) {
os_ << "\n" << " False-dirty ArtMethods\n";
os_ << " field contents:\n";
for (ArtMethod* method : false_dirty_entries_) {
// local class
ObjPtr<mirror::Class> declaring_class = method->GetDeclaringClass();
DumpOneArtMethod(method, declaring_class, nullptr);
}
}
void DumpCleanEntries() REQUIRES_SHARED(Locks::mutator_lock_) {
}
private:
std::ostream& os_;
MemberInfo member_info_;
std::map<const void*, std::string> entry_point_names_;
ClassLinker* class_linker_;
// Compute a map of addresses to names in the boot OAT file(s).
void BuildEntryPointNames() {
OatFileManager& oat_file_manager = Runtime::Current()->GetOatFileManager();
std::vector<const OatFile*> boot_oat_files = oat_file_manager.GetBootOatFiles();
for (const OatFile* oat_file : boot_oat_files) {
const OatHeader& oat_header = oat_file->GetOatHeader();
const void* jdl = oat_header.GetJniDlsymLookup();
if (jdl != nullptr) {
entry_point_names_[jdl] = "JniDlsymLookup (from boot oat file)";
}
const void* qgjt = oat_header.GetQuickGenericJniTrampoline();
if (qgjt != nullptr) {
entry_point_names_[qgjt] = "QuickGenericJniTrampoline (from boot oat file)";
}
const void* qrt = oat_header.GetQuickResolutionTrampoline();
if (qrt != nullptr) {
entry_point_names_[qrt] = "QuickResolutionTrampoline (from boot oat file)";
}
const void* qict = oat_header.GetQuickImtConflictTrampoline();
if (qict != nullptr) {
entry_point_names_[qict] = "QuickImtConflictTrampoline (from boot oat file)";
}
const void* q2ib = oat_header.GetQuickToInterpreterBridge();
if (q2ib != nullptr) {
entry_point_names_[q2ib] = "QuickToInterpreterBridge (from boot oat file)";
}
}
}
std::string StringFromBytes(const uint8_t* bytes, size_t size) {
switch (size) {
case 1:
return StringPrintf("%" PRIx8, *bytes);
case 2:
return StringPrintf("%" PRIx16, *reinterpret_cast<const uint16_t*>(bytes));
case 4:
case 8: {
// Compute an address if the bytes might contain one.
uint64_t intval;
if (size == 4) {
intval = *reinterpret_cast<const uint32_t*>(bytes);
} else {
intval = *reinterpret_cast<const uint64_t*>(bytes);
}
const void* addr = reinterpret_cast<const void*>(intval);
// Match the address against those that have Is* methods in the ClassLinker.
if (class_linker_->IsQuickToInterpreterBridge(addr)) {
return "QuickToInterpreterBridge";
} else if (class_linker_->IsQuickGenericJniStub(addr)) {
return "QuickGenericJniStub";
} else if (class_linker_->IsQuickResolutionStub(addr)) {
return "QuickResolutionStub";
} else if (class_linker_->IsJniDlsymLookupStub(addr)) {
return "JniDlsymLookupStub";
}
// Match the address against those that we saved from the boot OAT files.
if (entry_point_names_.find(addr) != entry_point_names_.end()) {
return entry_point_names_[addr];
}
return StringPrintf("%" PRIx64, intval);
}
default:
LOG(WARNING) << "Don't know how to convert " << size << " bytes to integer";
return "<UNKNOWN>";
}
}
void DumpOneArtMethod(ArtMethod* art_method,
ObjPtr<mirror::Class> declaring_class,
ObjPtr<mirror::Class> remote_declaring_class)
REQUIRES_SHARED(Locks::mutator_lock_) {
PointerSize pointer_size = InstructionSetPointerSize(Runtime::Current()->GetInstructionSet());
os_ << " " << reinterpret_cast<const void*>(art_method) << " ";
os_ << " entryPointFromJni: "
<< reinterpret_cast<const void*>(art_method->GetDataPtrSize(pointer_size)) << ", ";
os_ << " entryPointFromQuickCompiledCode: "
<< reinterpret_cast<const void*>(
art_method->GetEntryPointFromQuickCompiledCodePtrSize(pointer_size))
<< ", ";
os_ << " isNative? " << (art_method->IsNative() ? "yes" : "no") << ", ";
// Null for runtime metionds.
if (declaring_class != nullptr) {
os_ << " class_status (local): " << declaring_class->GetStatus();
}
if (remote_declaring_class != nullptr) {
os_ << ", class_status (remote): " << remote_declaring_class->GetStatus();
}
os_ << "\n";
}
DISALLOW_COPY_AND_ASSIGN(RegionSpecializedBase);
};
template <typename T>
class RegionData : public RegionSpecializedBase<T> {
public:
RegionData(std::ostream* os,
std::vector<uint8_t>* remote_contents,
std::vector<uint8_t>* zygote_contents,
const backtrace_map_t& boot_map,
const ImageHeader& image_header,
bool dump_dirty_objects)
: RegionSpecializedBase<T>(os,
remote_contents,
zygote_contents,
boot_map,
image_header,
dump_dirty_objects),
os_(*os) {
CHECK(remote_contents != nullptr);
CHECK(zygote_contents != nullptr);
}
// Walk over the type T entries in theregion between begin_image_ptr and end_image_ptr,
// collecting and reporting data regarding dirty, difference, etc.
void ProcessRegion(const MappingData& mapping_data,
RemoteProcesses remotes,
const uint8_t* begin_image_ptr)
REQUIRES_SHARED(Locks::mutator_lock_) {
typename RegionSpecializedBase<T>::VisitorClass visitor(
[this](T* entry,
const uint8_t* begin_image_ptr,
const std::set<size_t>& dirty_page_set) REQUIRES_SHARED(Locks::mutator_lock_) {
this->ComputeEntryDirty(entry, begin_image_ptr, dirty_page_set);
},
begin_image_ptr,
mapping_data.dirty_page_set);
PointerSize pointer_size = InstructionSetPointerSize(Runtime::Current()->GetInstructionSet());
RegionSpecializedBase<T>::VisitEntries(&visitor,
const_cast<uint8_t*>(begin_image_ptr),
pointer_size);
// Looking at only dirty pages, figure out how many of those bytes belong to dirty entries.
// TODO: fix this now that there are multiple regions in a mapping.
float true_dirtied_percent =
RegionCommon<T>::GetDirtyEntryBytes() * 1.0f / (mapping_data.dirty_pages * kPageSize);
// Entry specific statistics.
os_ << RegionCommon<T>::GetDifferentEntryCount() << " different entries, \n "
<< RegionCommon<T>::GetDirtyEntryBytes() << " different entry [bytes], \n "
<< RegionCommon<T>::GetFalseDirtyEntryCount() << " false dirty entries,\n "
<< RegionCommon<T>::GetFalseDirtyEntryBytes() << " false dirty entry [bytes], \n "
<< true_dirtied_percent << " different entries-vs-total in a dirty page;\n "
<< "\n";
const uint8_t* base_ptr = begin_image_ptr;
switch (remotes) {
case RemoteProcesses::kZygoteOnly:
os_ << " Zygote shared dirty entries: ";
break;
case RemoteProcesses::kImageAndZygote:
os_ << " Application dirty entries (private dirty): ";
// If we are dumping private dirty, diff against the zygote map to make it clearer what
// fields caused the page to be private dirty.
base_ptr = &RegionCommon<T>::zygote_contents_->operator[](0);
break;
case RemoteProcesses::kImageOnly:
os_ << " Application dirty entries (unknown whether private or shared dirty): ";
break;
}
DiffDirtyEntries(ProcessType::kRemote,
begin_image_ptr,
RegionCommon<T>::remote_contents_,
base_ptr,
/*log_dirty_objects=*/true);
// Print shared dirty after since it's less important.
if (RegionCommon<T>::GetZygoteDirtyEntryCount() != 0) {
// We only reach this point if both pids were specified. Furthermore,
// entries are only displayed here if they differed in both the image
// and the zygote, so they are probably private dirty.
CHECK(remotes == RemoteProcesses::kImageAndZygote);
os_ << "\n" << " Zygote dirty entries (probably shared dirty): ";
DiffDirtyEntries(ProcessType::kZygote,
begin_image_ptr,
RegionCommon<T>::zygote_contents_,
begin_image_ptr,
/*log_dirty_objects=*/false);
}
RegionSpecializedBase<T>::DumpDirtyObjects();
RegionSpecializedBase<T>::DumpDirtyEntries();
RegionSpecializedBase<T>::DumpFalseDirtyEntries();
RegionSpecializedBase<T>::DumpCleanEntries();
}
private:
std::ostream& os_;
void DiffDirtyEntries(ProcessType process_type,
const uint8_t* begin_image_ptr,
std::vector<uint8_t>* contents,
const uint8_t* base_ptr,
bool log_dirty_objects)
REQUIRES_SHARED(Locks::mutator_lock_) {
os_ << RegionCommon<T>::dirty_entries_.size() << "\n";
const std::set<T*>& entries =
(process_type == ProcessType::kZygote) ?
RegionCommon<T>::zygote_dirty_entries_:
RegionCommon<T>::image_dirty_entries_;
for (T* entry : entries) {
uint8_t* entry_bytes = reinterpret_cast<uint8_t*>(entry);
ptrdiff_t offset = entry_bytes - begin_image_ptr;
uint8_t* remote_bytes = &(*contents)[offset];
RegionSpecializedBase<T>::DiffEntryContents(entry,
remote_bytes,
&base_ptr[offset],
log_dirty_objects);
}
}
void ComputeEntryDirty(T* entry,
const uint8_t* begin_image_ptr,
const std::set<size_t>& dirty_pages)
REQUIRES_SHARED(Locks::mutator_lock_) {
// Set up pointers in the remote and the zygote for comparison.
uint8_t* current = reinterpret_cast<uint8_t*>(entry);
ptrdiff_t offset = current - begin_image_ptr;
T* entry_remote =
reinterpret_cast<T*>(const_cast<uint8_t*>(&(*RegionCommon<T>::remote_contents_)[offset]));
const bool have_zygote = !RegionCommon<T>::zygote_contents_->empty();
const uint8_t* current_zygote =
have_zygote ? &(*RegionCommon<T>::zygote_contents_)[offset] : nullptr;
T* entry_zygote = reinterpret_cast<T*>(const_cast<uint8_t*>(current_zygote));
// Visit and classify entries at the current location.
RegionSpecializedBase<T>::VisitEntry(entry);
// Test private dirty first.
bool is_dirty = false;
if (have_zygote) {
bool private_dirty = EntriesDiffer(entry_zygote, entry_remote);
if (private_dirty) {
// Private dirty, app vs zygote.
is_dirty = true;
RegionCommon<T>::AddImageDirtyEntry(entry);
}
if (EntriesDiffer(entry_zygote, entry)) {
// Shared dirty, zygote vs image.
is_dirty = true;
RegionCommon<T>::AddZygoteDirtyEntry(entry);
}
} else if (EntriesDiffer(entry_remote, entry)) {
// Shared or private dirty, app vs image.
is_dirty = true;
RegionCommon<T>::AddImageDirtyEntry(entry);
}
if (is_dirty) {
// TODO: Add support dirty entries in zygote and image.
RegionSpecializedBase<T>::AddDirtyEntry(entry, entry_remote);
} else {
RegionSpecializedBase<T>::AddCleanEntry(entry);
if (RegionCommon<T>::IsEntryOnDirtyPage(entry, dirty_pages)) {
// This entry was either never mutated or got mutated back to the same value.
// TODO: Do I want to distinguish a "different" vs a "dirty" page here?
RegionSpecializedBase<T>::AddFalseDirtyEntry(entry);
}
}
}
DISALLOW_COPY_AND_ASSIGN(RegionData);
};
} // namespace
class ImgDiagDumper {
public:
explicit ImgDiagDumper(std::ostream* os,
pid_t image_diff_pid,
pid_t zygote_diff_pid,
bool dump_dirty_objects)
: os_(os),
image_diff_pid_(image_diff_pid),
zygote_diff_pid_(zygote_diff_pid),
dump_dirty_objects_(dump_dirty_objects),
zygote_pid_only_(false) {}
bool Init() {
std::ostream& os = *os_;
if (image_diff_pid_ < 0 && zygote_diff_pid_ < 0) {
os << "Either --image-diff-pid or --zygote-diff-pid (or both) must be specified.\n";
return false;
}
// To avoid the combinations of command-line argument use cases:
// If the user invoked with only --zygote-diff-pid, shuffle that to
// image_diff_pid_, invalidate zygote_diff_pid_, and remember that
// image_diff_pid_ is now special.
if (image_diff_pid_ < 0) {
image_diff_pid_ = zygote_diff_pid_;
zygote_diff_pid_ = -1;
zygote_pid_only_ = true;
}
{
struct stat sts;
std::string proc_pid_str =
StringPrintf("/proc/%ld", static_cast<long>(image_diff_pid_)); // NOLINT [runtime/int]
if (stat(proc_pid_str.c_str(), &sts) == -1) {
os << "Process does not exist";
return false;
}
}
auto open_proc_maps = [&os](pid_t pid, /*out*/ std::unique_ptr<BacktraceMap>* proc_maps) {
// Open /proc/<pid>/maps to view memory maps.
proc_maps->reset(BacktraceMap::Create(pid));
if (*proc_maps == nullptr) {
os << "Could not read backtrace maps for " << pid;
return false;
}
return true;
};
auto open_file = [&os] (const char* file_name, /*out*/ std::unique_ptr<File>* file) {
file->reset(OS::OpenFileForReading(file_name));
if (*file == nullptr) {
os << "Failed to open " << file_name << " for reading";
return false;
}
return true;
};
auto open_mem_file = [&open_file](pid_t pid, /*out*/ std::unique_ptr<File>* mem_file) {
// Open /proc/<pid>/mem and for reading remote contents.
std::string mem_file_name =
StringPrintf("/proc/%ld/mem", static_cast<long>(pid)); // NOLINT [runtime/int]
return open_file(mem_file_name.c_str(), mem_file);
};
auto open_pagemap_file = [&open_file](pid_t pid, /*out*/ std::unique_ptr<File>* pagemap_file) {
// Open /proc/<pid>/pagemap.
std::string pagemap_file_name = StringPrintf(
"/proc/%ld/pagemap", static_cast<long>(pid)); // NOLINT [runtime/int]
return open_file(pagemap_file_name.c_str(), pagemap_file);
};
// Open files for inspecting image memory.
std::unique_ptr<BacktraceMap> image_proc_maps;
std::unique_ptr<File> image_mem_file;
std::unique_ptr<File> image_pagemap_file;
if (!open_proc_maps(image_diff_pid_, &image_proc_maps) ||
!open_mem_file(image_diff_pid_, &image_mem_file) ||
!open_pagemap_file(image_diff_pid_, &image_pagemap_file)) {
return false;
}
// If zygote_diff_pid_ != -1, open files for inspecting zygote memory.
std::unique_ptr<BacktraceMap> zygote_proc_maps;
std::unique_ptr<File> zygote_mem_file;
std::unique_ptr<File> zygote_pagemap_file;
if (zygote_diff_pid_ != -1) {
if (!open_proc_maps(zygote_diff_pid_, &zygote_proc_maps) ||
!open_mem_file(zygote_diff_pid_, &zygote_mem_file) ||
!open_pagemap_file(zygote_diff_pid_, &zygote_pagemap_file)) {
return false;
}
}
std::unique_ptr<File> clean_pagemap_file;
std::unique_ptr<File> kpageflags_file;
std::unique_ptr<File> kpagecount_file;
if (!open_file("/proc/self/pagemap", &clean_pagemap_file) ||
!open_file("/proc/kpageflags", &kpageflags_file) ||
!open_file("/proc/kpagecount", &kpagecount_file)) {
return false;
}
// Note: the boot image is not really clean but close enough.
// For now, log pages found to be dirty.
// TODO: Rewrite imgdiag to load boot image without creating a runtime.
// FIXME: The following does not reliably detect dirty pages.
Runtime* runtime = Runtime::Current();
CHECK(!runtime->ShouldRelocate());
size_t total_dirty_pages = 0u;
for (gc::space::ImageSpace* space : runtime->GetHeap()->GetBootImageSpaces()) {
const ImageHeader& image_header = space->GetImageHeader();
const uint8_t* image_begin = image_header.GetImageBegin();
const uint8_t* image_end = AlignUp(image_begin + image_header.GetImageSize(), kPageSize);
size_t virtual_page_idx_begin = reinterpret_cast<uintptr_t>(image_begin) / kPageSize;
size_t virtual_page_idx_end = reinterpret_cast<uintptr_t>(image_end) / kPageSize;
size_t num_virtual_pages = virtual_page_idx_end - virtual_page_idx_begin;
std::string error_msg;
std::vector<uint64_t> page_frame_numbers(num_virtual_pages);
if (!GetPageFrameNumbers(clean_pagemap_file.get(),
virtual_page_idx_begin,
ArrayRef<uint64_t>(page_frame_numbers),
&error_msg)) {
os << "Failed to get page frame numbers for image space " << space->GetImageLocation()
<< ", error: " << error_msg;
return false;
}
std::vector<uint64_t> page_flags(num_virtual_pages);
if (!GetPageFlagsOrCounts(kpageflags_file.get(),
ArrayRef<const uint64_t>(page_frame_numbers),
ArrayRef<uint64_t>(page_flags),
&error_msg)) {
os << "Failed to get page flags for image space " << space->GetImageLocation()
<< ", error: " << error_msg;
return false;
}
size_t num_dirty_pages = 0u;
std::optional<size_t> first_dirty_page;
for (size_t i = 0u, size = page_flags.size(); i != size; ++i) {
if (UNLIKELY((page_flags[i] & kPageFlagsDirtyMask) != 0u)) {
++num_dirty_pages;
if (!first_dirty_page.has_value()) {
first_dirty_page = i;
}
}
}
if (num_dirty_pages != 0u) {
DCHECK(first_dirty_page.has_value());
os << "Found " << num_dirty_pages << " dirty pages for " << space->GetImageLocation()
<< ", first dirty page: " << first_dirty_page.value_or(0u);
total_dirty_pages += num_dirty_pages;
}
}
// Commit the mappings and files.
image_proc_maps_ = std::move(image_proc_maps);
image_mem_file_ = std::move(*image_mem_file);
image_pagemap_file_ = std::move(*image_pagemap_file);
if (zygote_diff_pid_ != -1) {
zygote_proc_maps_ = std::move(zygote_proc_maps);
zygote_mem_file_ = std::move(*zygote_mem_file);
zygote_pagemap_file_ = std::move(*zygote_pagemap_file);
}
clean_pagemap_file_ = std::move(*clean_pagemap_file);
kpageflags_file_ = std::move(*kpageflags_file);
kpagecount_file_ = std::move(*kpagecount_file);
return true;
}
bool Dump(const ImageHeader& image_header, const std::string& image_location)
REQUIRES_SHARED(Locks::mutator_lock_) {
std::ostream& os = *os_;
os << "IMAGE LOCATION: " << image_location << "\n\n";
os << "MAGIC: " << image_header.GetMagic() << "\n\n";
os << "IMAGE BEGIN: " << reinterpret_cast<void*>(image_header.GetImageBegin()) << "\n\n";
PrintPidLine("IMAGE", image_diff_pid_);
os << "\n\n";
PrintPidLine("ZYGOTE", zygote_diff_pid_);
bool ret = true;
if (image_diff_pid_ >= 0 || zygote_diff_pid_ >= 0) {
ret = DumpImageDiff(image_header, image_location);
os << "\n\n";
}
os << std::flush;
return ret;
}
private:
bool DumpImageDiff(const ImageHeader& image_header, const std::string& image_location)
REQUIRES_SHARED(Locks::mutator_lock_) {
return DumpImageDiffMap(image_header, image_location);
}
bool ComputeDirtyBytes(const ImageHeader& image_header,
const uint8_t* image_begin,
const backtrace_map_t& boot_map,
const std::vector<uint8_t>& remote_contents,
MappingData* mapping_data /*out*/) {
std::ostream& os = *os_;
size_t virtual_page_idx = 0; // Virtual page number (for an absolute memory address)
size_t page_idx = 0; // Page index relative to 0
size_t previous_page_idx = 0; // Previous page index relative to 0
// Iterate through one page at a time. Boot map begin/end already implicitly aligned.
for (uintptr_t begin = boot_map.start; begin != boot_map.end; begin += kPageSize) {
ptrdiff_t offset = begin - boot_map.start;
// We treat the image header as part of the memory map for now
// If we wanted to change this, we could pass base=start+sizeof(ImageHeader)
// But it might still be interesting to see if any of the ImageHeader data mutated
const uint8_t* local_ptr = reinterpret_cast<const uint8_t*>(&image_header) + offset;
const uint8_t* remote_ptr = &remote_contents[offset];
if (memcmp(local_ptr, remote_ptr, kPageSize) != 0) {
mapping_data->different_pages++;
// Count the number of 32-bit integers that are different.
for (size_t i = 0; i < kPageSize / sizeof(uint32_t); ++i) {
const uint32_t* remote_ptr_int32 = reinterpret_cast<const uint32_t*>(remote_ptr);
const uint32_t* local_ptr_int32 = reinterpret_cast<const uint32_t*>(local_ptr);
if (remote_ptr_int32[i] != local_ptr_int32[i]) {
mapping_data->different_int32s++;
}
}
}
}
std::vector<size_t> private_dirty_pages_for_section(ImageHeader::kSectionCount, 0u);
// Iterate through one byte at a time.
ptrdiff_t page_off_begin = image_header.GetImageBegin() - image_begin;
for (uintptr_t begin = boot_map.start; begin != boot_map.end; ++begin) {
previous_page_idx = page_idx;
ptrdiff_t offset = begin - boot_map.start;
// We treat the image header as part of the memory map for now
// If we wanted to change this, we could pass base=start+sizeof(ImageHeader)
// But it might still be interesting to see if any of the ImageHeader data mutated
const uint8_t* local_ptr = reinterpret_cast<const uint8_t*>(&image_header) + offset;
const uint8_t* remote_ptr = &remote_contents[offset];
virtual_page_idx = reinterpret_cast<uintptr_t>(local_ptr) / kPageSize;
// Calculate the page index, relative to the 0th page where the image begins
page_idx = (offset + page_off_begin) / kPageSize;
if (*local_ptr != *remote_ptr) {
// Track number of bytes that are different
mapping_data->different_bytes++;
}
// Independently count the # of dirty pages on the remote side
size_t remote_virtual_page_idx = begin / kPageSize;
if (previous_page_idx != page_idx) {
uint64_t page_count = 0xC0FFEE;
// TODO: virtual_page_idx needs to be from the same process
std::string error_msg;
int dirtiness = (IsPageDirty(&image_pagemap_file_, // Image-diff-pid procmap
&clean_pagemap_file_, // Self procmap
&kpageflags_file_,
&kpagecount_file_,
remote_virtual_page_idx, // potentially "dirty" page
virtual_page_idx, // true "clean" page
&page_count,
&error_msg));
if (dirtiness < 0) {
os << error_msg;
return false;
} else if (dirtiness > 0) {
mapping_data->dirty_pages++;
mapping_data->dirty_page_set.insert(mapping_data->dirty_page_set.end(), virtual_page_idx);
}
bool is_dirty = dirtiness > 0;
bool is_private = page_count == 1;
if (page_count == 1) {
mapping_data->private_pages++;
}
if (is_dirty && is_private) {
mapping_data->private_dirty_pages++;
for (size_t i = 0; i < ImageHeader::kSectionCount; ++i) {
const ImageHeader::ImageSections section = static_cast<ImageHeader::ImageSections>(i);
if (image_header.GetImageSection(section).Contains(offset)) {
++private_dirty_pages_for_section[i];
}
}
}
}
}
mapping_data->false_dirty_pages = mapping_data->dirty_pages - mapping_data->different_pages;
// Print low-level (bytes, int32s, pages) statistics.
os << mapping_data->different_bytes << " differing bytes,\n "
<< mapping_data->different_int32s << " differing int32s,\n "
<< mapping_data->different_pages << " differing pages,\n "
<< mapping_data->dirty_pages << " pages are dirty;\n "
<< mapping_data->false_dirty_pages << " pages are false dirty;\n "
<< mapping_data->private_pages << " pages are private;\n "
<< mapping_data->private_dirty_pages << " pages are Private_Dirty\n "
<< "\n";
size_t total_private_dirty_pages = std::accumulate(private_dirty_pages_for_section.begin(),
private_dirty_pages_for_section.end(),
0u);
os << "Image sections (total private dirty pages " << total_private_dirty_pages << ")\n";
for (size_t i = 0; i < ImageHeader::kSectionCount; ++i) {
const ImageHeader::ImageSections section = static_cast<ImageHeader::ImageSections>(i);
os << section << " " << image_header.GetImageSection(section)
<< " private dirty pages=" << private_dirty_pages_for_section[i] << "\n";
}
os << "\n";
return true;
}
// Look at /proc/$pid/mem and only diff the things from there
bool DumpImageDiffMap(const ImageHeader& image_header, const std::string& image_location)
REQUIRES_SHARED(Locks::mutator_lock_) {
std::ostream& os = *os_;
std::string error_msg;
std::string image_location_base_name = GetImageLocationBaseName(image_location);
// FIXME: BacktraceMap should provide a const_iterator so that we can take `maps` as const&.
auto find_boot_map = [&os, &image_location_base_name](BacktraceMap& maps, const char* tag)
-> std::optional<backtrace_map_t> {
// Find the memory map for the current boot image component.
for (const backtrace_map_t* map : maps) {
if (EndsWith(map->name, image_location_base_name)) {
if ((map->flags & PROT_WRITE) != 0) {
return *map;
}
// In actuality there's more than 1 map, but the second one is read-only.
// The one we care about is the write-able map.
// The readonly maps are guaranteed to be identical, so its not interesting to compare
// them.
}
}
os << "Could not find map for " << image_location_base_name << " in " << tag;
return std::nullopt;
};
// Find the current boot image mapping.
std::optional<backtrace_map_t> maybe_boot_map = find_boot_map(*image_proc_maps_, "image");
if (maybe_boot_map == std::nullopt) {
return false;
}
backtrace_map_t boot_map = maybe_boot_map.value_or(backtrace_map_t{});
// Sanity check boot_map_.
CHECK(boot_map.end >= boot_map.start);
// The size of the boot image mapping.
size_t boot_map_size = boot_map.end - boot_map.start;
// If zygote_diff_pid_ != -1, check that the zygote boot map is the same.
if (zygote_diff_pid_ != -1) {
std::optional<backtrace_map_t> maybe_zygote_boot_map =
find_boot_map(*zygote_proc_maps_, "zygote");
if (maybe_zygote_boot_map == std::nullopt) {
return false;
}
backtrace_map_t zygote_boot_map = maybe_zygote_boot_map.value_or(backtrace_map_t{});
if (zygote_boot_map.start != boot_map.start || zygote_boot_map.end != boot_map.end) {
os << "Zygote boot map does not match image boot map: "
<< "zygote begin " << reinterpret_cast<const void*>(zygote_boot_map.start)
<< ", zygote end " << reinterpret_cast<const void*>(zygote_boot_map.end)
<< ", image begin " << reinterpret_cast<const void*>(boot_map.start)
<< ", image end " << reinterpret_cast<const void*>(boot_map.end);
return false;
}
}
// Walk the bytes and diff against our boot image
os << "\nObserving boot image header at address "
<< reinterpret_cast<const void*>(&image_header)
<< "\n\n";
const uint8_t* image_begin_unaligned = image_header.GetImageBegin();
const uint8_t* image_end_unaligned = image_begin_unaligned + image_header.GetImageSize();
// Adjust range to nearest page
const uint8_t* image_begin = AlignDown(image_begin_unaligned, kPageSize);
const uint8_t* image_end = AlignUp(image_end_unaligned, kPageSize);
size_t image_size = image_end - image_begin;
if (image_size != boot_map_size) {
os << "Remote boot map size does not match local boot map size: "
<< "local size " << image_size
<< ", remote size " << boot_map_size;
return false;
}
// The contents of /proc/<image_diff_pid_>/maps.
std::vector<uint8_t> remote_contents(boot_map_size);
if (!image_mem_file_.PreadFully(remote_contents.data(), boot_map_size, boot_map.start)) {
os << "Could not fully read file " << image_mem_file_.GetPath();
return false;
}
// The contents of /proc/<zygote_diff_pid_>/maps.
std::vector<uint8_t> zygote_contents;
if (zygote_diff_pid_ != -1) {
zygote_contents.resize(boot_map_size);
if (!zygote_mem_file_.PreadFully(zygote_contents.data(), boot_map_size, boot_map.start)) {
LOG(WARNING) << "Could not fully read zygote file " << zygote_mem_file_.GetPath();
return false;
}
}
// FIXME: Because of ASLR, this check shall fail for most processes.
// We need to update the entire diff to work with the ASLR. b/77856493
if (reinterpret_cast<uintptr_t>(image_begin) > boot_map.start ||
reinterpret_cast<uintptr_t>(image_end) < boot_map.end) {
// Sanity check that we aren't trying to read a completely different boot image
os << "Remote boot map is out of range of local boot map: " <<
"local begin " << reinterpret_cast<const void*>(image_begin) <<
", local end " << reinterpret_cast<const void*>(image_end) <<
", remote begin " << reinterpret_cast<const void*>(boot_map.start) <<
", remote end " << reinterpret_cast<const void*>(boot_map.end);
return false;
// If we wanted even more validation we could map the ImageHeader from the file
}
MappingData mapping_data;
os << "Mapping at [" << reinterpret_cast<void*>(boot_map.start) << ", "
<< reinterpret_cast<void*>(boot_map.end) << ") had:\n ";
if (!ComputeDirtyBytes(image_header, image_begin, boot_map, remote_contents, &mapping_data)) {
return false;
}
RemoteProcesses remotes;
if (zygote_pid_only_) {
remotes = RemoteProcesses::kZygoteOnly;
} else if (zygote_diff_pid_ > 0) {
remotes = RemoteProcesses::kImageAndZygote;
} else {
remotes = RemoteProcesses::kImageOnly;
}
// Check all the mirror::Object entries in the image.
RegionData<mirror::Object> object_region_data(os_,
&remote_contents,
&zygote_contents,
boot_map,
image_header,
dump_dirty_objects_);
object_region_data.ProcessRegion(mapping_data,
remotes,
image_begin_unaligned);
// Check all the ArtMethod entries in the image.
RegionData<ArtMethod> artmethod_region_data(os_,
&remote_contents,
&zygote_contents,
boot_map,
image_header,
dump_dirty_objects_);
artmethod_region_data.ProcessRegion(mapping_data,
remotes,
image_begin_unaligned);
return true;
}
// Note: On failure, `*page_frame_number` shall be clobbered.
static bool GetPageFrameNumber(File* page_map_file,
size_t virtual_page_index,
/*out*/ uint64_t* page_frame_number,
/*out*/ std::string* error_msg) {
CHECK(page_frame_number != nullptr);
return GetPageFrameNumbers(page_map_file,
virtual_page_index,
ArrayRef<uint64_t>(page_frame_number, 1u),
error_msg);
}
// Note: On failure, `page_frame_numbers[.]` shall be clobbered.
static bool GetPageFrameNumbers(File* page_map_file,
size_t virtual_page_index,
/*out*/ ArrayRef<uint64_t> page_frame_numbers,
/*out*/ std::string* error_msg) {
CHECK(page_map_file != nullptr);
CHECK_NE(page_frame_numbers.size(), 0u);
CHECK(page_frame_numbers.data() != nullptr);
CHECK(error_msg != nullptr);
// Read 64-bit entries from /proc/$pid/pagemap to get the physical page frame numbers.
if (!page_map_file->PreadFully(page_frame_numbers.data(),
page_frame_numbers.size() * kPageMapEntrySize,
virtual_page_index * kPageMapEntrySize)) {
*error_msg = StringPrintf("Failed to read the virtual page index entries from %s, error: %s",
page_map_file->GetPath().c_str(),
strerror(errno));
return false;
}
// Extract page frame numbers from pagemap entries.
for (uint64_t& page_frame_number : page_frame_numbers) {
page_frame_number &= kPageFrameNumberMask;
}
return true;
}
// Note: On failure, `page_flags_or_counts[.]` shall be clobbered.
static bool GetPageFlagsOrCounts(File* kpage_file,
ArrayRef<const uint64_t> page_frame_numbers,
/*out*/ ArrayRef<uint64_t> page_flags_or_counts,
/*out*/ std::string* error_msg) {
static_assert(kPageFlagsEntrySize == kPageCountEntrySize, "entry size check");
CHECK_NE(page_frame_numbers.size(), 0u);
CHECK_EQ(page_flags_or_counts.size(), page_frame_numbers.size());
CHECK(kpage_file != nullptr);
CHECK(page_frame_numbers.data() != nullptr);
CHECK(page_flags_or_counts.data() != nullptr);
CHECK(error_msg != nullptr);
size_t size = page_frame_numbers.size();
size_t i = 0;
while (i != size) {
size_t start = i;
++i;
while (i != size && page_frame_numbers[i] - page_frame_numbers[start] == i - start) {
++i;
}
// Read 64-bit entries from /proc/kpageflags or /proc/kpagecount.
if (!kpage_file->PreadFully(page_flags_or_counts.data() + start,
(i - start) * kPageMapEntrySize,
page_frame_numbers[start] * kPageFlagsEntrySize)) {
*error_msg = StringPrintf("Failed to read the page flags or counts from %s, error: %s",
kpage_file->GetPath().c_str(),
strerror(errno));
return false;
}
}
return true;
}
static int IsPageDirty(File* page_map_file,
File* clean_pagemap_file,
File* kpageflags_file,
File* kpagecount_file,
size_t virtual_page_idx,
size_t clean_virtual_page_idx,
// Out parameters:
uint64_t* page_count, std::string* error_msg) {
CHECK(page_map_file != nullptr);
CHECK(clean_pagemap_file != nullptr);
CHECK_NE(page_map_file, clean_pagemap_file);
CHECK(kpageflags_file != nullptr);
CHECK(kpagecount_file != nullptr);
CHECK(page_count != nullptr);
CHECK(error_msg != nullptr);
// Constants are from https://www.kernel.org/doc/Documentation/vm/pagemap.txt
uint64_t page_frame_number = 0;
if (!GetPageFrameNumber(page_map_file, virtual_page_idx, &page_frame_number, error_msg)) {
return -1;
}
uint64_t page_frame_number_clean = 0;
if (!GetPageFrameNumber(clean_pagemap_file, clean_virtual_page_idx, &page_frame_number_clean,
error_msg)) {
return -1;
}
// Read 64-bit entry from /proc/kpageflags to get the dirty bit for a page
uint64_t kpage_flags_entry = 0;
if (!kpageflags_file->PreadFully(&kpage_flags_entry,
kPageFlagsEntrySize,
page_frame_number * kPageFlagsEntrySize)) {
*error_msg = StringPrintf("Failed to read the page flags from %s",
kpageflags_file->GetPath().c_str());
return -1;
}
// Read 64-bit entyry from /proc/kpagecount to get mapping counts for a page
if (!kpagecount_file->PreadFully(page_count /*out*/,
kPageCountEntrySize,
page_frame_number * kPageCountEntrySize)) {
*error_msg = StringPrintf("Failed to read the page count from %s",
kpagecount_file->GetPath().c_str());
return -1;
}
// There must be a page frame at the requested address.
CHECK_EQ(kpage_flags_entry & kPageFlagsNoPageMask, 0u);
// The page frame must be memory mapped
CHECK_NE(kpage_flags_entry & kPageFlagsMmapMask, 0u);
// Page is dirty, i.e. has diverged from file, if the 4th bit is set to 1
bool flags_dirty = (kpage_flags_entry & kPageFlagsDirtyMask) != 0;
// page_frame_number_clean must come from the *same* process
// but a *different* mmap than page_frame_number
if (flags_dirty) {
CHECK_NE(page_frame_number, page_frame_number_clean)
<< " count: " << *page_count << " flags: 0x" << std::hex << kpage_flags_entry;
}
return page_frame_number != page_frame_number_clean;
}
void PrintPidLine(const std::string& kind, pid_t pid) {
if (pid < 0) {
*os_ << kind << " DIFF PID: disabled\n\n";
} else {
*os_ << kind << " DIFF PID (" << pid << "): ";
}
}
// Return suffix of the file path after the last /. (e.g. /foo/bar -> bar, bar -> bar)
static std::string BaseName(const std::string& str) {
size_t idx = str.rfind('/');
if (idx == std::string::npos) {
return str;
}
return str.substr(idx + 1);
}
// Return the image location, stripped of any directories, e.g. "boot.art" or "core.art"
static std::string GetImageLocationBaseName(const std::string& image_location) {
return BaseName(std::string(image_location));
}
static constexpr size_t kPageMapEntrySize = sizeof(uint64_t);
// bits 0-54 [in /proc/$pid/pagemap]
static constexpr uint64_t kPageFrameNumberMask = (1ULL << 55) - 1;
static constexpr size_t kPageFlagsEntrySize = sizeof(uint64_t);
static constexpr size_t kPageCountEntrySize = sizeof(uint64_t);
static constexpr uint64_t kPageFlagsDirtyMask = (1ULL << 4); // in /proc/kpageflags
static constexpr uint64_t kPageFlagsNoPageMask = (1ULL << 20); // in /proc/kpageflags
static constexpr uint64_t kPageFlagsMmapMask = (1ULL << 11); // in /proc/kpageflags
std::ostream* os_;
pid_t image_diff_pid_; // Dump image diff against boot.art if pid is non-negative
pid_t zygote_diff_pid_; // Dump image diff against zygote boot.art if pid is non-negative
bool dump_dirty_objects_; // Adds dumping of objects that are dirty.
bool zygote_pid_only_; // The user only specified a pid for the zygote.
// BacktraceMap used for finding the memory mapping of the image file.
std::unique_ptr<BacktraceMap> image_proc_maps_;
// A File for reading /proc/<image_diff_pid_>/mem.
File image_mem_file_;
// A File for reading /proc/<image_diff_pid_>/pagemap.
File image_pagemap_file_;
// BacktraceMap used for finding the memory mapping of the zygote image file.
std::unique_ptr<BacktraceMap> zygote_proc_maps_;
// A File for reading /proc/<zygote_diff_pid_>/mem.
File zygote_mem_file_;
// A File for reading /proc/<zygote_diff_pid_>/pagemap.
File zygote_pagemap_file_;
// A File for reading /proc/self/pagemap.
File clean_pagemap_file_;
// A File for reading /proc/kpageflags.
File kpageflags_file_;
// A File for reading /proc/kpagecount.
File kpagecount_file_;
DISALLOW_COPY_AND_ASSIGN(ImgDiagDumper);
};
static int DumpImage(Runtime* runtime,
std::ostream* os,
pid_t image_diff_pid,
pid_t zygote_diff_pid,
bool dump_dirty_objects) {
ScopedObjectAccess soa(Thread::Current());
gc::Heap* heap = runtime->GetHeap();
const std::vector<gc::space::ImageSpace*>& image_spaces = heap->GetBootImageSpaces();
CHECK(!image_spaces.empty());
ImgDiagDumper img_diag_dumper(os,
image_diff_pid,
zygote_diff_pid,
dump_dirty_objects);
if (!img_diag_dumper.Init()) {
return EXIT_FAILURE;
}
for (gc::space::ImageSpace* image_space : image_spaces) {
const ImageHeader& image_header = image_space->GetImageHeader();
if (!image_header.IsValid()) {
fprintf(stderr, "Invalid image header %s\n", image_space->GetImageLocation().c_str());
return EXIT_FAILURE;
}
if (!img_diag_dumper.Dump(image_header, image_space->GetImageLocation())) {
return EXIT_FAILURE;
}
}
return EXIT_SUCCESS;
}
struct ImgDiagArgs : public CmdlineArgs {
protected:
using Base = CmdlineArgs;
ParseStatus ParseCustom(const char* raw_option,
size_t raw_option_length,
std::string* error_msg) override {
DCHECK_EQ(strlen(raw_option), raw_option_length);
{
ParseStatus base_parse = Base::ParseCustom(raw_option, raw_option_length, error_msg);
if (base_parse != kParseUnknownArgument) {
return base_parse;
}
}
std::string_view option(raw_option, raw_option_length);
if (StartsWith(option, "--image-diff-pid=")) {
const char* image_diff_pid = raw_option + strlen("--image-diff-pid=");
if (!android::base::ParseInt(image_diff_pid, &image_diff_pid_)) {
*error_msg = "Image diff pid out of range";
return kParseError;
}
} else if (StartsWith(option, "--zygote-diff-pid=")) {
const char* zygote_diff_pid = raw_option + strlen("--zygote-diff-pid=");
if (!android::base::ParseInt(zygote_diff_pid, &zygote_diff_pid_)) {
*error_msg = "Zygote diff pid out of range";
return kParseError;
}
} else if (option == "--dump-dirty-objects") {
dump_dirty_objects_ = true;
} else {
return kParseUnknownArgument;
}
return kParseOk;
}
ParseStatus ParseChecks(std::string* error_msg) override {
// Perform the parent checks.
ParseStatus parent_checks = Base::ParseChecks(error_msg);
if (parent_checks != kParseOk) {
return parent_checks;
}
// Perform our own checks.
if (kill(image_diff_pid_,
/*sig*/0) != 0) { // No signal is sent, perform error-checking only.
// Check if the pid exists before proceeding.
if (errno == ESRCH) {
*error_msg = "Process specified does not exist";
} else {
*error_msg = StringPrintf("Failed to check process status: %s", strerror(errno));
}
return kParseError;
} else if (instruction_set_ != InstructionSet::kNone && instruction_set_ != kRuntimeISA) {
// Don't allow different ISAs since the images are ISA-specific.
// Right now the code assumes both the runtime ISA and the remote ISA are identical.
*error_msg = "Must use the default runtime ISA; changing ISA is not supported.";
return kParseError;
}
return kParseOk;
}
std::string GetUsage() const override {
std::string usage;
usage +=
"Usage: imgdiag [options] ...\n"
" Example: imgdiag --image-diff-pid=$(pidof dex2oat)\n"
" Example: adb shell imgdiag --image-diff-pid=$(pid zygote)\n"
"\n";
usage += Base::GetUsage();
usage += // Optional.
" --image-diff-pid=<pid>: provide the PID of a process whose boot.art you want to diff.\n"
" Example: --image-diff-pid=$(pid zygote)\n"
" --zygote-diff-pid=<pid>: provide the PID of the zygote whose boot.art you want to diff "
"against.\n"
" Example: --zygote-diff-pid=$(pid zygote)\n"
" --dump-dirty-objects: additionally output dirty objects of interest.\n"
"\n";
return usage;
}
public:
pid_t image_diff_pid_ = -1;
pid_t zygote_diff_pid_ = -1;
bool dump_dirty_objects_ = false;
};
struct ImgDiagMain : public CmdlineMain<ImgDiagArgs> {
bool ExecuteWithRuntime(Runtime* runtime) override {
CHECK(args_ != nullptr);
return DumpImage(runtime,
args_->os_,
args_->image_diff_pid_,
args_->zygote_diff_pid_,
args_->dump_dirty_objects_) == EXIT_SUCCESS;
}
};
} // namespace art
int main(int argc, char** argv) {
art::ImgDiagMain main;
return main.Main(argc, argv);
}