Add a new imgdiag tool to diff boot.art/core.art against a process
Analyze the dirty memory pages of a running process per-object,
this allows is to to fine-tune the dirty object binning algorithm in
image writer.
Also:
* Factor out oatdump command line parsing code into cmdline.h
* Factor out common build rules for building variations of binaries
* Add a gtest for imgdiag
Bug: 17611661
Change-Id: I3ac852a0d223af66f6d59ae5dbc3df101475e3d0
diff --git a/imgdiag/imgdiag.cc b/imgdiag/imgdiag.cc
new file mode 100644
index 0000000..9b57ecb
--- /dev/null
+++ b/imgdiag/imgdiag.cc
@@ -0,0 +1,951 @@
+/*
+ * 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 <iostream>
+#include <string>
+#include <vector>
+#include <set>
+#include <map>
+
+#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 "mirror/art_method-inl.h"
+#include "image.h"
+#include "scoped_thread_state_change.h"
+#include "os.h"
+#include "gc_map.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 char* image_location,
+ pid_t image_diff_pid)
+ : os_(os),
+ image_header_(image_header),
+ image_location_(image_location),
+ image_diff_pid_(image_diff_pid) {}
+
+ bool Dump() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
+ std::ostream& os = *os_;
+ 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_);
+ 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) SHARED_LOCKS_REQUIRED(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/$pid/maps to view memory maps
+ auto proc_maps = std::unique_ptr<BacktraceMap>(BacktraceMap::Create(image_diff_pid));
+ if (proc_maps == nullptr) {
+ os << "Could not read backtrace maps";
+ return false;
+ }
+
+ bool found_boot_map = false;
+ backtrace_map_t boot_map = backtrace_map_t();
+ // Find the memory map only for boot.art
+ for (const backtrace_map_t& map : *proc_maps) {
+ if (EndsWith(map.name, GetImageLocationBaseName())) {
+ if ((map.flags & PROT_WRITE) != 0) {
+ boot_map = map;
+ found_boot_map = true;
+ break;
+ }
+ // In actuality there's more than 1 map, but the second one is read-only.
+ // The one we care about is the write-able map.
+ // The readonly maps are guaranteed to be identical, so its not interesting to compare
+ // them.
+ }
+ }
+
+ if (!found_boot_map) {
+ os << "Could not find map for " << GetImageLocationBaseName();
+ return false;
+ }
+
+ // Future idea: diff against zygote so we can ignore the shared dirty pages.
+ return DumpImageDiffMap(image_diff_pid, boot_map);
+ }
+
+ // Look at /proc/$pid/mem and only diff the things from there
+ bool DumpImageDiffMap(pid_t image_diff_pid, const backtrace_map_t& boot_map)
+ SHARED_LOCKS_REQUIRED(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 = GetBootImageHeader();
+
+ 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_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::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;
+ }
+
+ std::set<size_t> dirty_page_set_remote; // Set of the remote virtual page indices that are dirty
+ std::set<size_t> dirty_page_set_local; // Set of the local virtual page indices that are dirty
+
+ 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++;
+ }
+ }
+ }
+
+ // Walk each object in the remote image space and compare it against ours
+ size_t different_objects = 0;
+ std::map<mirror::Class*, int /*count*/> dirty_object_class_map;
+ // Track only the byte-per-byte dirtiness (in bytes)
+ std::map<mirror::Class*, int /*byte_count*/> dirty_object_byte_count;
+ // Track the object-by-object dirtiness (in bytes)
+ std::map<mirror::Class*, int /*byte_count*/> dirty_object_size_in_bytes;
+ std::map<mirror::Class*, int /*count*/> clean_object_class_map;
+
+ std::map<mirror::Class*, std::string> class_to_descriptor_map;
+
+ std::map<off_t /* field offset */, int /* count */> art_method_field_dirty_count;
+ std::vector<mirror::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;
+ std::map<mirror::Class*, int /*byte_count*/> false_dirty_byte_count;
+ std::map<mirror::Class*, int /*object_count*/> false_dirty_object_count;
+ std::map<mirror::Class*, std::vector<mirror::Object*>> false_dirty_objects_map;
+ size_t false_dirty_object_bytes = 0;
+
+ // Remote pointers to dirty objects
+ std::map<mirror::Class*, std::vector<mirror::Object*>> dirty_objects_by_class;
+ // 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;
+
+ size_t dirty_object_bytes = 0;
+ {
+ const uint8_t* begin_image_ptr = image_begin_unaligned;
+ const uint8_t* end_image_ptr = image_end_unaligned;
+
+ const uint8_t* current = begin_image_ptr + RoundUp(sizeof(ImageHeader), kObjectAlignment);
+ while (reinterpret_cast<const uintptr_t>(current)
+ < reinterpret_cast<const 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();
+
+ bool different_object = false;
+
+ // 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));
+ if (memcmp(current, current_remote, obj->SizeOf()) != 0) {
+ different_objects++;
+ dirty_object_bytes += obj->SizeOf();
+
+ ++dirty_object_class_map[klass];
+
+ // 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++;
+ }
+ }
+ dirty_object_byte_count[klass] += dirty_byte_count_per_object;
+ dirty_object_size_in_bytes[klass] += obj->SizeOf();
+
+ different_object = true;
+
+ dirty_objects_by_class[klass].push_back(remote_obj);
+ } else {
+ ++clean_object_class_map[klass];
+ }
+
+ std::string descriptor = GetClassDescriptor(klass);
+ if (different_object) {
+ if (strcmp(descriptor.c_str(), "Ljava/lang/Class;") == 0) {
+ // 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
+ mirror::ArtMethod* art_method = reinterpret_cast<mirror::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);
+ false_dirty_objects_map[klass].push_back(obj);
+ false_dirty_object_bytes += obj->SizeOf();
+ false_dirty_byte_count[obj->GetClass()] += obj->SizeOf();
+ false_dirty_object_count[obj->GetClass()] += 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_to_descriptor_map[klass] = 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(dirty_object_class_map);
+ auto clean_object_class_values = SortByValueDesc(clean_object_class_map);
+
+ 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 = dirty_object_size_in_bytes[klass];
+ float avg_dirty_bytes_per_class = dirty_object_byte_count[klass] * 1.0f / object_sizes;
+ float avg_object_size = object_sizes * 1.0f / dirty_object_count;
+ const std::string& descriptor = class_to_descriptor_map[klass];
+ 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(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 = dirty_objects_by_class[klass];
+ for (mirror::Object* obj : dirty_objects_list) {
+ // remote method
+ auto art_method = reinterpret_cast<mirror::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 << " entryPointFromInterpreter: "
+ << reinterpret_cast<const void*>(
+ art_method->GetEntryPointFromInterpreterPtrSize<kVerifyNone>(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(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 = dirty_objects_by_class[klass];
+ 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(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 = false_dirty_byte_count[klass];
+ float avg_object_size = object_sizes * 1.0f / object_count;
+ const std::string& descriptor = class_to_descriptor_map[klass];
+ 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 = false_dirty_objects_map[klass];
+
+ os << " field contents:\n";
+ for (mirror::Object* obj : art_method_false_dirty_objects) {
+ // local method
+ auto art_method = reinterpret_cast<mirror::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 << " entryPointFromInterpreter: "
+ << reinterpret_cast<const void*>(
+ art_method->GetEntryPointFromInterpreterPtrSize<kVerifyNone>(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_LOCKS_REQUIRED(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>
+ static std::vector<std::pair<V, K>> SortByValueDesc(const std::map<K, V> map) {
+ // 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(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;
+ }
+
+ static const ImageHeader& GetBootImageHeader() {
+ gc::Heap* heap = Runtime::Current()->GetHeap();
+ gc::space::ImageSpace* image_space = heap->GetImageSpace();
+ CHECK(image_space != nullptr);
+ const ImageHeader& image_header = image_space->GetImageHeader();
+ return image_header;
+ }
+
+ 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 char* image_location_;
+ pid_t image_diff_pid_; // Dump image diff against boot.art if pid is non-negative
+
+ DISALLOW_COPY_AND_ASSIGN(ImgDiagDumper);
+};
+
+static int DumpImage(Runtime* runtime, const char* image_location,
+ std::ostream* os, pid_t image_diff_pid) {
+ ScopedObjectAccess soa(Thread::Current());
+ gc::Heap* heap = runtime->GetHeap();
+ gc::space::ImageSpace* image_space = heap->GetImageSpace();
+ CHECK(image_space != nullptr);
+ const ImageHeader& image_header = image_space->GetImageHeader();
+ if (!image_header.IsValid()) {
+ fprintf(stderr, "Invalid image header %s\n", image_location);
+ return EXIT_FAILURE;
+ }
+
+ ImgDiagDumper img_diag_dumper(os, image_header, image_location, image_diff_pid);
+
+ bool success = img_diag_dumper.Dump();
+ return (success) ? EXIT_SUCCESS : EXIT_FAILURE;
+}
+
+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 {
+ 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"
+ "\n";
+
+ return usage;
+ }
+
+ public:
+ pid_t image_diff_pid_ = -1;
+};
+
+struct ImgDiagMain : public CmdlineMain<ImgDiagArgs> {
+ virtual bool ExecuteWithRuntime(Runtime* runtime) {
+ CHECK(args_ != nullptr);
+
+ return DumpImage(runtime,
+ args_->boot_image_location_,
+ args_->os_,
+ args_->image_diff_pid_) == EXIT_SUCCESS;
+ }
+};
+
+} // namespace art
+
+int main(int argc, char** argv) {
+ art::ImgDiagMain main;
+ return main.Main(argc, argv);
+}