/*
* 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 <string>
#include <vector>
#include <set>
#include <map>
#include <unordered_set>
#include "art_method-inl.h"
#include "base/unix_file/fd_file.h"
#include "base/stringprintf.h"
#include "gc/space/image_space.h"
#include "gc/heap.h"
#include "mirror/class-inl.h"
#include "mirror/object-inl.h"
#include "image.h"
#include "scoped_thread_state_change.h"
#include "os.h"
#include "cmdline.h"
#include "backtrace/BacktraceMap.h"
#include <sys/stat.h>
#include <sys/types.h>
#include <signal.h>
namespace art {
class ImgDiagDumper {
public:
explicit ImgDiagDumper(std::ostream* os,
const ImageHeader& image_header,
const std::string& image_location,
pid_t image_diff_pid,
pid_t zygote_diff_pid)
: os_(os),
image_header_(image_header),
image_location_(image_location),
image_diff_pid_(image_diff_pid),
zygote_diff_pid_(zygote_diff_pid) {}
bool Dump() SHARED_REQUIRES(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";
bool ret = true;
if (image_diff_pid_ >= 0) {
os << "IMAGE DIFF PID (" << image_diff_pid_ << "): ";
ret = DumpImageDiff(image_diff_pid_, zygote_diff_pid_);
os << "\n\n";
} else {
os << "IMAGE DIFF PID: disabled\n\n";
}
os << std::flush;
return ret;
}
private:
static bool EndsWith(const std::string& str, const std::string& suffix) {
return str.size() >= suffix.size() &&
str.compare(str.size() - suffix.size(), suffix.size(), suffix) == 0;
}
// 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);
}
bool DumpImageDiff(pid_t image_diff_pid, pid_t zygote_diff_pid)
SHARED_REQUIRES(Locks::mutator_lock_) {
std::ostream& os = *os_;
{
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;
}
}
// Open /proc/$pid/maps to view memory maps
auto proc_maps = std::unique_ptr<BacktraceMap>(BacktraceMap::Create(image_diff_pid));
if (proc_maps == nullptr) {
os << "Could not read backtrace maps";
return false;
}
bool found_boot_map = false;
backtrace_map_t boot_map = backtrace_map_t();
// Find the memory map only for boot.art
for (const backtrace_map_t& map : *proc_maps) {
if (EndsWith(map.name, GetImageLocationBaseName())) {
if ((map.flags & PROT_WRITE) != 0) {
boot_map = map;
found_boot_map = true;
break;
}
// 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.
}
}
if (!found_boot_map) {
os << "Could not find map for " << GetImageLocationBaseName();
return false;
}
// Future idea: diff against zygote so we can ignore the shared dirty pages.
return DumpImageDiffMap(image_diff_pid, zygote_diff_pid, boot_map);
}
static std::string PrettyFieldValue(ArtField* field, mirror::Object* obj)
SHARED_REQUIRES(Locks::mutator_lock_) {
std::ostringstream oss;
switch (field->GetTypeAsPrimitiveType()) {
case Primitive::kPrimNot: {
oss << obj->GetFieldObject<mirror::Object, kVerifyNone, kWithoutReadBarrier>(
field->GetOffset());
break;
}
case Primitive::kPrimBoolean: {
oss << static_cast<bool>(obj->GetFieldBoolean<kVerifyNone>(field->GetOffset()));
break;
}
case Primitive::kPrimByte: {
oss << static_cast<int32_t>(obj->GetFieldByte<kVerifyNone>(field->GetOffset()));
break;
}
case Primitive::kPrimChar: {
oss << obj->GetFieldChar<kVerifyNone>(field->GetOffset());
break;
}
case Primitive::kPrimShort: {
oss << obj->GetFieldShort<kVerifyNone>(field->GetOffset());
break;
}
case Primitive::kPrimInt: {
oss << obj->GetField32<kVerifyNone>(field->GetOffset());
break;
}
case Primitive::kPrimLong: {
oss << obj->GetField64<kVerifyNone>(field->GetOffset());
break;
}
case Primitive::kPrimFloat: {
oss << obj->GetField32<kVerifyNone>(field->GetOffset());
break;
}
case Primitive::kPrimDouble: {
oss << obj->GetField64<kVerifyNone>(field->GetOffset());
break;
}
case Primitive::kPrimVoid: {
oss << "void";
break;
}
}
return oss.str();
}
// Aggregate and detail class data from an image diff.
struct ClassData {
int dirty_object_count = 0;
// Track only the byte-per-byte dirtiness (in bytes)
int dirty_object_byte_count = 0;
// Track the object-by-object dirtiness (in bytes)
int dirty_object_size_in_bytes = 0;
int clean_object_count = 0;
std::string descriptor;
int false_dirty_byte_count = 0;
int false_dirty_object_count = 0;
std::vector<mirror::Object*> false_dirty_objects;
// Remote pointers to dirty objects
std::vector<mirror::Object*> dirty_objects;
};
void DiffObjectContents(mirror::Object* obj,
uint8_t* remote_bytes,
std::ostream& os) SHARED_REQUIRES(Locks::mutator_lock_) {
const char* tabs = " ";
// Attempt to find fields for all dirty bytes.
mirror::Class* klass = obj->GetClass();
if (obj->IsClass()) {
os << tabs << "Class " << PrettyClass(obj->AsClass()) << " " << obj << "\n";
} else {
os << tabs << "Instance of " << PrettyClass(klass) << " " << obj << "\n";
}
std::unordered_set<ArtField*> dirty_instance_fields;
std::unordered_set<ArtField*> dirty_static_fields;
const uint8_t* obj_bytes = reinterpret_cast<const uint8_t*>(obj);
mirror::Object* remote_obj = reinterpret_cast<mirror::Object*>(remote_bytes);
for (size_t i = 0, count = obj->SizeOf(); i < count; ++i) {
if (obj_bytes[i] != remote_bytes[i]) {
ArtField* field = ArtField::FindInstanceFieldWithOffset</*exact*/false>(klass, i);
if (field != nullptr) {
dirty_instance_fields.insert(field);
} else if (obj->IsClass()) {
field = ArtField::FindStaticFieldWithOffset</*exact*/false>(obj->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();
if (i >= data_offset) {
os << tabs << "Dirty array element " << (i - data_offset) / component_size << "\n";
// Skip to next element to prevent spam.
i += component_size - 1;
continue;
}
}
os << tabs << "No field for byte offset " << i << "\n";
}
}
}
// Dump different fields. TODO: Dump field contents.
if (!dirty_instance_fields.empty()) {
os << tabs << "Dirty instance fields " << dirty_instance_fields.size() << "\n";
for (ArtField* field : dirty_instance_fields) {
os << tabs << PrettyField(field)
<< " original=" << PrettyFieldValue(field, obj)
<< " remote=" << PrettyFieldValue(field, remote_obj) << "\n";
}
}
if (!dirty_static_fields.empty()) {
os << tabs << "Dirty static fields " << dirty_static_fields.size() << "\n";
for (ArtField* field : dirty_static_fields) {
os << tabs << PrettyField(field)
<< " original=" << PrettyFieldValue(field, obj)
<< " remote=" << PrettyFieldValue(field, remote_obj) << "\n";
}
}
os << "\n";
}
// Look at /proc/$pid/mem and only diff the things from there
bool DumpImageDiffMap(pid_t image_diff_pid,
pid_t zygote_diff_pid,
const backtrace_map_t& boot_map)
SHARED_REQUIRES(Locks::mutator_lock_) {
std::ostream& os = *os_;
const size_t pointer_size = InstructionSetPointerSize(
Runtime::Current()->GetInstructionSet());
std::string file_name =
StringPrintf("/proc/%ld/mem", static_cast<long>(image_diff_pid)); // NOLINT [runtime/int]
size_t boot_map_size = boot_map.end - boot_map.start;
// Open /proc/$pid/mem as a file
auto map_file = std::unique_ptr<File>(OS::OpenFileForReading(file_name.c_str()));
if (map_file == nullptr) {
os << "Failed to open " << file_name << " for reading";
return false;
}
// Memory-map /proc/$pid/mem subset from the boot map
CHECK(boot_map.end >= boot_map.start);
std::string error_msg;
// Walk the bytes and diff against our boot image
const ImageHeader& boot_image_header = image_header_;
os << "\nObserving boot image header at address "
<< reinterpret_cast<const void*>(&boot_image_header)
<< "\n\n";
const uint8_t* image_begin_unaligned = boot_image_header.GetImageBegin();
const uint8_t* image_mirror_end_unaligned = image_begin_unaligned +
boot_image_header.GetImageSection(ImageHeader::kSectionObjects).Size();
const uint8_t* image_end_unaligned = image_begin_unaligned + boot_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);
ptrdiff_t page_off_begin = boot_image_header.GetImageBegin() - image_begin;
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
}
std::vector<uint8_t> remote_contents(boot_map_size);
if (!map_file->PreadFully(&remote_contents[0], boot_map_size, boot_map.start)) {
os << "Could not fully read file " << file_name;
return false;
}
std::vector<uint8_t> zygote_contents;
std::unique_ptr<File> zygote_map_file;
if (zygote_diff_pid != -1) {
std::string zygote_file_name =
StringPrintf("/proc/%ld/mem", static_cast<long>(zygote_diff_pid)); // NOLINT [runtime/int]
zygote_map_file.reset(OS::OpenFileForReading(zygote_file_name.c_str()));
// The boot map should be at the same address.
zygote_contents.resize(boot_map_size);
if (!zygote_map_file->PreadFully(&zygote_contents[0], boot_map_size, boot_map.start)) {
LOG(WARNING) << "Could not fully read zygote file " << zygote_file_name;
zygote_contents.clear();
}
}
std::string page_map_file_name = StringPrintf(
"/proc/%ld/pagemap", static_cast<long>(image_diff_pid)); // NOLINT [runtime/int]
auto page_map_file = std::unique_ptr<File>(OS::OpenFileForReading(page_map_file_name.c_str()));
if (page_map_file == nullptr) {
os << "Failed to open " << page_map_file_name << " for reading: " << strerror(errno);
return false;
}
// Not truly clean, mmap-ing boot.art again would be more pristine, but close enough
const char* clean_page_map_file_name = "/proc/self/pagemap";
auto clean_page_map_file = std::unique_ptr<File>(
OS::OpenFileForReading(clean_page_map_file_name));
if (clean_page_map_file == nullptr) {
os << "Failed to open " << clean_page_map_file_name << " for reading: " << strerror(errno);
return false;
}
auto kpage_flags_file = std::unique_ptr<File>(OS::OpenFileForReading("/proc/kpageflags"));
if (kpage_flags_file == nullptr) {
os << "Failed to open /proc/kpageflags for reading: " << strerror(errno);
return false;
}
auto kpage_count_file = std::unique_ptr<File>(OS::OpenFileForReading("/proc/kpagecount"));
if (kpage_count_file == nullptr) {
os << "Failed to open /proc/kpagecount for reading:" << strerror(errno);
return false;
}
// Set of the remote virtual page indices that are dirty
std::set<size_t> dirty_page_set_remote;
// Set of the local virtual page indices that are dirty
std::set<size_t> dirty_page_set_local;
size_t different_int32s = 0;
size_t different_bytes = 0;
size_t different_pages = 0;
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
size_t dirty_pages = 0;
size_t private_pages = 0;
size_t private_dirty_pages = 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*>(&boot_image_header) + offset;
uint8_t* remote_ptr = &remote_contents[offset];
if (memcmp(local_ptr, remote_ptr, kPageSize) != 0) {
different_pages++;
// Count the number of 32-bit integers that are different.
for (size_t i = 0; i < kPageSize / sizeof(uint32_t); ++i) {
uint32_t* remote_ptr_int32 = reinterpret_cast<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]) {
different_int32s++;
}
}
}
}
// Iterate through one byte at a time.
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*>(&boot_image_header) + offset;
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
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
int dirtiness = (IsPageDirty(page_map_file.get(), // Image-diff-pid procmap
clean_page_map_file.get(), // Self procmap
kpage_flags_file.get(),
kpage_count_file.get(),
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) {
dirty_pages++;
dirty_page_set_remote.insert(dirty_page_set_remote.end(), remote_virtual_page_idx);
dirty_page_set_local.insert(dirty_page_set_local.end(), virtual_page_idx);
}
bool is_dirty = dirtiness > 0;
bool is_private = page_count == 1;
if (page_count == 1) {
private_pages++;
}
if (is_dirty && is_private) {
private_dirty_pages++;
}
}
}
std::map<mirror::Class*, ClassData> class_data;
// Walk each object in the remote image space and compare it against ours
size_t different_objects = 0;
std::map<off_t /* field offset */, int /* count */> art_method_field_dirty_count;
std::vector<ArtMethod*> art_method_dirty_objects;
std::map<off_t /* field offset */, int /* count */> class_field_dirty_count;
std::vector<mirror::Class*> class_dirty_objects;
// List of local objects that are clean, but located on dirty pages.
std::vector<mirror::Object*> false_dirty_objects;
size_t false_dirty_object_bytes = 0;
// Look up remote classes by their descriptor
std::map<std::string, mirror::Class*> remote_class_map;
// Look up local classes by their descriptor
std::map<std::string, mirror::Class*> local_class_map;
// Objects that are dirty against the image (possibly shared or private dirty).
std::set<mirror::Object*> image_dirty_objects;
// Objects that are dirty against the zygote (probably private dirty).
std::set<mirror::Object*> zygote_dirty_objects;
size_t dirty_object_bytes = 0;
const uint8_t* begin_image_ptr = image_begin_unaligned;
const uint8_t* end_image_ptr = image_mirror_end_unaligned;
const uint8_t* current = begin_image_ptr + RoundUp(sizeof(ImageHeader), kObjectAlignment);
while (reinterpret_cast<uintptr_t>(current) < reinterpret_cast<uintptr_t>(end_image_ptr)) {
CHECK_ALIGNED(current, kObjectAlignment);
mirror::Object* obj = reinterpret_cast<mirror::Object*>(const_cast<uint8_t*>(current));
// Sanity check that we are reading a real object
CHECK(obj->GetClass() != nullptr) << "Image object at address " << obj << " has null class";
if (kUseBakerOrBrooksReadBarrier) {
obj->AssertReadBarrierPointer();
}
// Iterate every page this object belongs to
bool on_dirty_page = false;
size_t page_off = 0;
size_t current_page_idx;
uintptr_t object_address;
do {
object_address = reinterpret_cast<uintptr_t>(current);
current_page_idx = object_address / kPageSize + page_off;
if (dirty_page_set_local.find(current_page_idx) != dirty_page_set_local.end()) {
// This object is on a dirty page
on_dirty_page = true;
}
page_off++;
} while ((current_page_idx * kPageSize) <
RoundUp(object_address + obj->SizeOf(), kObjectAlignment));
mirror::Class* klass = obj->GetClass();
// Check against the other object and see if they are different
ptrdiff_t offset = current - begin_image_ptr;
const uint8_t* current_remote = &remote_contents[offset];
mirror::Object* remote_obj = reinterpret_cast<mirror::Object*>(
const_cast<uint8_t*>(current_remote));
bool different_image_object = memcmp(current, current_remote, obj->SizeOf()) != 0;
if (different_image_object) {
bool different_zygote_object = false;
if (!zygote_contents.empty()) {
const uint8_t* zygote_ptr = &zygote_contents[offset];
different_zygote_object = memcmp(current, zygote_ptr, obj->SizeOf()) != 0;
}
if (different_zygote_object) {
// Different from zygote.
zygote_dirty_objects.insert(obj);
} else {
// Just different from iamge.
image_dirty_objects.insert(obj);
}
different_objects++;
dirty_object_bytes += obj->SizeOf();
++class_data[klass].dirty_object_count;
// Go byte-by-byte and figure out what exactly got dirtied
size_t dirty_byte_count_per_object = 0;
for (size_t i = 0; i < obj->SizeOf(); ++i) {
if (current[i] != current_remote[i]) {
dirty_byte_count_per_object++;
}
}
class_data[klass].dirty_object_byte_count += dirty_byte_count_per_object;
class_data[klass].dirty_object_size_in_bytes += obj->SizeOf();
class_data[klass].dirty_objects.push_back(remote_obj);
} else {
++class_data[klass].clean_object_count;
}
std::string descriptor = GetClassDescriptor(klass);
if (different_image_object) {
if (klass->IsClassClass()) {
// this is a "Class"
mirror::Class* obj_as_class = reinterpret_cast<mirror::Class*>(remote_obj);
// print the fields that are dirty
for (size_t i = 0; i < obj->SizeOf(); ++i) {
if (current[i] != current_remote[i]) {
class_field_dirty_count[i]++;
}
}
class_dirty_objects.push_back(obj_as_class);
} else if (strcmp(descriptor.c_str(), "Ljava/lang/reflect/ArtMethod;") == 0) {
// this is an ArtMethod
ArtMethod* art_method = reinterpret_cast<ArtMethod*>(remote_obj);
// print the fields that are dirty
for (size_t i = 0; i < obj->SizeOf(); ++i) {
if (current[i] != current_remote[i]) {
art_method_field_dirty_count[i]++;
}
}
art_method_dirty_objects.push_back(art_method);
}
} else if (on_dirty_page) {
// This object 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?
false_dirty_objects.push_back(obj);
class_data[klass].false_dirty_objects.push_back(obj);
false_dirty_object_bytes += obj->SizeOf();
class_data[obj->GetClass()].false_dirty_byte_count += obj->SizeOf();
class_data[obj->GetClass()].false_dirty_object_count += 1;
}
if (strcmp(descriptor.c_str(), "Ljava/lang/Class;") == 0) {
local_class_map[descriptor] = reinterpret_cast<mirror::Class*>(obj);
remote_class_map[descriptor] = reinterpret_cast<mirror::Class*>(remote_obj);
}
// Unconditionally store the class descriptor in case we need it later
class_data[klass].descriptor = descriptor;
current += RoundUp(obj->SizeOf(), kObjectAlignment);
}
// Looking at only dirty pages, figure out how many of those bytes belong to dirty objects.
float true_dirtied_percent = dirty_object_bytes * 1.0f / (dirty_pages * kPageSize);
size_t false_dirty_pages = dirty_pages - different_pages;
os << "Mapping at [" << reinterpret_cast<void*>(boot_map.start) << ", "
<< reinterpret_cast<void*>(boot_map.end) << ") had: \n "
<< different_bytes << " differing bytes, \n "
<< different_int32s << " differing int32s, \n "
<< different_objects << " different objects, \n "
<< dirty_object_bytes << " different object [bytes], \n "
<< false_dirty_objects.size() << " false dirty objects,\n "
<< false_dirty_object_bytes << " false dirty object [bytes], \n "
<< true_dirtied_percent << " different objects-vs-total in a dirty page;\n "
<< different_pages << " different pages; \n "
<< dirty_pages << " pages are dirty; \n "
<< false_dirty_pages << " pages are false dirty; \n "
<< private_pages << " pages are private; \n "
<< private_dirty_pages << " pages are Private_Dirty\n "
<< "";
// vector of pairs (int count, Class*)
auto dirty_object_class_values = SortByValueDesc<mirror::Class*, int, ClassData>(
class_data, [](const ClassData& d) { return d.dirty_object_count; });
auto clean_object_class_values = SortByValueDesc<mirror::Class*, int, ClassData>(
class_data, [](const ClassData& d) { return d.clean_object_count; });
if (!zygote_dirty_objects.empty()) {
os << "\n" << " Dirty objects compared to zygote (probably private dirty): "
<< zygote_dirty_objects.size() << "\n";
for (mirror::Object* obj : zygote_dirty_objects) {
const uint8_t* obj_bytes = reinterpret_cast<const uint8_t*>(obj);
ptrdiff_t offset = obj_bytes - begin_image_ptr;
uint8_t* remote_bytes = &zygote_contents[offset];
DiffObjectContents(obj, remote_bytes, os);
}
}
os << "\n" << " Dirty objects compared to image (private or shared dirty): "
<< image_dirty_objects.size() << "\n";
for (mirror::Object* obj : image_dirty_objects) {
const uint8_t* obj_bytes = reinterpret_cast<const uint8_t*>(obj);
ptrdiff_t offset = obj_bytes - begin_image_ptr;
uint8_t* remote_bytes = &remote_contents[offset];
DiffObjectContents(obj, remote_bytes, os);
}
os << "\n" << " Dirty object count by class:\n";
for (const auto& vk_pair : dirty_object_class_values) {
int dirty_object_count = vk_pair.first;
mirror::Class* klass = vk_pair.second;
int object_sizes = class_data[klass].dirty_object_size_in_bytes;
float avg_dirty_bytes_per_class =
class_data[klass].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[klass].descriptor;
os << " " << PrettyClass(klass) << " ("
<< "objects: " << dirty_object_count << ", "
<< "avg dirty bytes: " << avg_dirty_bytes_per_class << ", "
<< "avg object size: " << avg_object_size << ", "
<< "class descriptor: '" << descriptor << "'"
<< ")\n";
constexpr size_t kMaxAddressPrint = 5;
if (strcmp(descriptor.c_str(), "Ljava/lang/reflect/ArtMethod;") == 0) {
os << " sample object addresses: ";
for (size_t i = 0; i < art_method_dirty_objects.size() && i < kMaxAddressPrint; ++i) {
auto art_method = art_method_dirty_objects[i];
os << reinterpret_cast<void*>(art_method) << ", ";
}
os << "\n";
os << " dirty byte +offset:count list = ";
auto art_method_field_dirty_count_sorted =
SortByValueDesc<off_t, int, int>(art_method_field_dirty_count);
for (auto pair : art_method_field_dirty_count_sorted) {
off_t offset = pair.second;
int count = pair.first;
os << "+" << offset << ":" << count << ", ";
}
os << "\n";
os << " field contents:\n";
const auto& dirty_objects_list = class_data[klass].dirty_objects;
for (mirror::Object* obj : dirty_objects_list) {
// remote method
auto art_method = reinterpret_cast<ArtMethod*>(obj);
// remote class
mirror::Class* remote_declaring_class =
FixUpRemotePointer(art_method->GetDeclaringClass(), remote_contents, boot_map);
// local class
mirror::Class* declaring_class =
RemoteContentsPointerToLocal(remote_declaring_class,
remote_contents,
boot_image_header);
os << " " << reinterpret_cast<void*>(obj) << " ";
os << " entryPointFromJni: "
<< reinterpret_cast<const void*>(
art_method->GetEntryPointFromJniPtrSize(pointer_size)) << ", ";
os << " entryPointFromQuickCompiledCode: "
<< reinterpret_cast<const void*>(
art_method->GetEntryPointFromQuickCompiledCodePtrSize(pointer_size))
<< ", ";
os << " isNative? " << (art_method->IsNative() ? "yes" : "no") << ", ";
os << " class_status (local): " << declaring_class->GetStatus();
os << " class_status (remote): " << remote_declaring_class->GetStatus();
os << "\n";
}
}
if (strcmp(descriptor.c_str(), "Ljava/lang/Class;") == 0) {
os << " sample object addresses: ";
for (size_t i = 0; i < class_dirty_objects.size() && i < kMaxAddressPrint; ++i) {
auto class_ptr = class_dirty_objects[i];
os << reinterpret_cast<void*>(class_ptr) << ", ";
}
os << "\n";
os << " dirty byte +offset:count list = ";
auto class_field_dirty_count_sorted =
SortByValueDesc<off_t, int, int>(class_field_dirty_count);
for (auto pair : class_field_dirty_count_sorted) {
off_t offset = pair.second;
int count = pair.first;
os << "+" << offset << ":" << count << ", ";
}
os << "\n";
os << " field contents:\n";
const auto& dirty_objects_list = class_data[klass].dirty_objects;
for (mirror::Object* obj : dirty_objects_list) {
// remote class object
auto remote_klass = reinterpret_cast<mirror::Class*>(obj);
// local class object
auto local_klass = RemoteContentsPointerToLocal(remote_klass,
remote_contents,
boot_image_header);
os << " " << reinterpret_cast<void*>(obj) << " ";
os << " class_status (remote): " << remote_klass->GetStatus() << ", ";
os << " class_status (local): " << local_klass->GetStatus();
os << "\n";
}
}
}
auto false_dirty_object_class_values = SortByValueDesc<mirror::Class*, int, 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) {
int object_count = vk_pair.first;
mirror::Class* klass = vk_pair.second;
int object_sizes = class_data[klass].false_dirty_byte_count;
float avg_object_size = object_sizes * 1.0f / object_count;
const std::string& descriptor = class_data[klass].descriptor;
os << " " << PrettyClass(klass) << " ("
<< "objects: " << object_count << ", "
<< "avg object size: " << avg_object_size << ", "
<< "total bytes: " << object_sizes << ", "
<< "class descriptor: '" << descriptor << "'"
<< ")\n";
if (strcmp(descriptor.c_str(), "Ljava/lang/reflect/ArtMethod;") == 0) {
auto& art_method_false_dirty_objects = class_data[klass].false_dirty_objects;
os << " field contents:\n";
for (mirror::Object* obj : art_method_false_dirty_objects) {
// local method
auto art_method = reinterpret_cast<ArtMethod*>(obj);
// local class
mirror::Class* declaring_class = art_method->GetDeclaringClass();
os << " " << reinterpret_cast<void*>(obj) << " ";
os << " entryPointFromJni: "
<< reinterpret_cast<const void*>(
art_method->GetEntryPointFromJniPtrSize(pointer_size)) << ", ";
os << " entryPointFromQuickCompiledCode: "
<< reinterpret_cast<const void*>(
art_method->GetEntryPointFromQuickCompiledCodePtrSize(pointer_size))
<< ", ";
os << " isNative? " << (art_method->IsNative() ? "yes" : "no") << ", ";
os << " class_status (local): " << declaring_class->GetStatus();
os << "\n";
}
}
}
os << "\n" << " Clean object count by class:\n";
for (const auto& vk_pair : clean_object_class_values) {
os << " " << PrettyClass(vk_pair.second) << " (" << vk_pair.first << ")\n";
}
return true;
}
// 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 T* FixUpRemotePointer(T* remote_ptr,
std::vector<uint8_t>& remote_contents,
const backtrace_map_t& boot_map) {
if (remote_ptr == nullptr) {
return nullptr;
}
uintptr_t remote = reinterpret_cast<uintptr_t>(remote_ptr);
CHECK_LE(boot_map.start, remote);
CHECK_GT(boot_map.end, remote);
off_t boot_offset = remote - boot_map.start;
return reinterpret_cast<T*>(&remote_contents[boot_offset]);
}
template <typename T>
static T* RemoteContentsPointerToLocal(T* remote_ptr,
std::vector<uint8_t>& remote_contents,
const ImageHeader& image_header) {
if (remote_ptr == nullptr) {
return nullptr;
}
uint8_t* remote = reinterpret_cast<uint8_t*>(remote_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));
}
static std::string GetClassDescriptor(mirror::Class* klass)
SHARED_REQUIRES(Locks::mutator_lock_) {
CHECK(klass != nullptr);
std::string descriptor;
const char* descriptor_str = klass->GetDescriptor(&descriptor);
return std::string(descriptor_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;
}
static bool GetPageFrameNumber(File* page_map_file,
size_t virtual_page_index,
uint64_t* page_frame_number,
std::string* error_msg) {
CHECK(page_map_file != nullptr);
CHECK(page_frame_number != nullptr);
CHECK(error_msg != nullptr);
constexpr size_t kPageMapEntrySize = sizeof(uint64_t);
constexpr uint64_t kPageFrameNumberMask = (1ULL << 55) - 1; // bits 0-54 [in /proc/$pid/pagemap]
constexpr uint64_t kPageSoftDirtyMask = (1ULL << 55); // bit 55 [in /proc/$pid/pagemap]
uint64_t page_map_entry = 0;
// Read 64-bit entry from /proc/$pid/pagemap to get the physical page frame number
if (!page_map_file->PreadFully(&page_map_entry, kPageMapEntrySize,
virtual_page_index * kPageMapEntrySize)) {
*error_msg = StringPrintf("Failed to read the virtual page index entry from %s",
page_map_file->GetPath().c_str());
return false;
}
// TODO: seems useless, remove this.
bool soft_dirty = (page_map_entry & kPageSoftDirtyMask) != 0;
if ((false)) {
LOG(VERBOSE) << soft_dirty; // Suppress unused warning
UNREACHABLE();
}
*page_frame_number = page_map_entry & kPageFrameNumberMask;
return true;
}
static int IsPageDirty(File* page_map_file,
File* clean_page_map_file,
File* kpage_flags_file,
File* kpage_count_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_page_map_file != nullptr);
CHECK_NE(page_map_file, clean_page_map_file);
CHECK(kpage_flags_file != nullptr);
CHECK(kpage_count_file != nullptr);
CHECK(page_count != nullptr);
CHECK(error_msg != nullptr);
// Constants are from https://www.kernel.org/doc/Documentation/vm/pagemap.txt
constexpr size_t kPageFlagsEntrySize = sizeof(uint64_t);
constexpr size_t kPageCountEntrySize = sizeof(uint64_t);
constexpr uint64_t kPageFlagsDirtyMask = (1ULL << 4); // in /proc/kpageflags
constexpr uint64_t kPageFlagsNoPageMask = (1ULL << 20); // in /proc/kpageflags
constexpr uint64_t kPageFlagsMmapMask = (1ULL << 11); // in /proc/kpageflags
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_page_map_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 (!kpage_flags_file->PreadFully(&kpage_flags_entry,
kPageFlagsEntrySize,
page_frame_number * kPageFlagsEntrySize)) {
*error_msg = StringPrintf("Failed to read the page flags from %s",
kpage_flags_file->GetPath().c_str());
return -1;
}
// Read 64-bit entyry from /proc/kpagecount to get mapping counts for a page
if (!kpage_count_file->PreadFully(page_count /*out*/,
kPageCountEntrySize,
page_frame_number * kPageCountEntrySize)) {
*error_msg = StringPrintf("Failed to read the page count from %s",
kpage_count_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);
}
return page_frame_number != page_frame_number_clean;
}
private:
// Return the image location, stripped of any directories, e.g. "boot.art" or "core.art"
std::string GetImageLocationBaseName() const {
return BaseName(std::string(image_location_));
}
std::ostream* os_;
const ImageHeader& image_header_;
const std::string image_location_;
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
DISALLOW_COPY_AND_ASSIGN(ImgDiagDumper);
};
static int DumpImage(Runtime* runtime,
std::ostream* os,
pid_t image_diff_pid,
pid_t zygote_diff_pid) {
ScopedObjectAccess soa(Thread::Current());
gc::Heap* heap = runtime->GetHeap();
std::vector<gc::space::ImageSpace*> image_spaces = heap->GetBootImageSpaces();
CHECK(!image_spaces.empty());
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;
}
ImgDiagDumper img_diag_dumper(os,
image_header,
image_space->GetImageLocation(),
image_diff_pid,
zygote_diff_pid);
if (!img_diag_dumper.Dump()) {
return EXIT_FAILURE;
}
}
return EXIT_SUCCESS;
}
struct ImgDiagArgs : public CmdlineArgs {
protected:
using Base = CmdlineArgs;
virtual ParseStatus ParseCustom(const StringPiece& option,
std::string* error_msg) OVERRIDE {
{
ParseStatus base_parse = Base::ParseCustom(option, error_msg);
if (base_parse != kParseUnknownArgument) {
return base_parse;
}
}
if (option.starts_with("--image-diff-pid=")) {
const char* image_diff_pid = option.substr(strlen("--image-diff-pid=")).data();
if (!ParseInt(image_diff_pid, &image_diff_pid_)) {
*error_msg = "Image diff pid out of range";
return kParseError;
}
} else if (option.starts_with("--zygote-diff-pid=")) {
const char* zygote_diff_pid = option.substr(strlen("--zygote-diff-pid=")).data();
if (!ParseInt(zygote_diff_pid, &zygote_diff_pid_)) {
*error_msg = "Zygote diff pid out of range";
return kParseError;
}
} else {
return kParseUnknownArgument;
}
return kParseOk;
}
virtual 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_ != 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;
}
virtual std::string GetUsage() const {
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"
"\n";
return usage;
}
public:
pid_t image_diff_pid_ = -1;
pid_t zygote_diff_pid_ = -1;
};
struct ImgDiagMain : public CmdlineMain<ImgDiagArgs> {
virtual bool ExecuteWithRuntime(Runtime* runtime) {
CHECK(args_ != nullptr);
return DumpImage(runtime,
args_->os_,
args_->image_diff_pid_,
args_->zygote_diff_pid_) == EXIT_SUCCESS;
}
};
} // namespace art
int main(int argc, char** argv) {
art::ImgDiagMain main;
return main.Main(argc, argv);
}