1/* 2 * Copyright (C) 2014 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17#include <stdio.h> 18#include <stdlib.h> 19 20#include <fstream> 21#include <functional> 22#include <iostream> 23#include <string> 24#include <vector> 25#include <set> 26#include <map> 27#include <unordered_set> 28 29#include "android-base/stringprintf.h" 30 31#include "art_field-inl.h" 32#include "art_method-inl.h" 33#include "base/unix_file/fd_file.h" 34#include "gc/space/image_space.h" 35#include "gc/heap.h" 36#include "mirror/class-inl.h" 37#include "mirror/object-inl.h" 38#include "image.h" 39#include "scoped_thread_state_change-inl.h" 40#include "os.h" 41 42#include "cmdline.h" 43#include "backtrace/BacktraceMap.h" 44 45#include <sys/stat.h> 46#include <sys/types.h> 47#include <signal.h> 48 49namespace art { 50 51using android::base::StringPrintf; 52 53class ImgDiagDumper { 54 public: 55 explicit ImgDiagDumper(std::ostream* os, 56 const ImageHeader& image_header, 57 const std::string& image_location, 58 pid_t image_diff_pid, 59 pid_t zygote_diff_pid) 60 : os_(os), 61 image_header_(image_header), 62 image_location_(image_location), 63 image_diff_pid_(image_diff_pid), 64 zygote_diff_pid_(zygote_diff_pid) {} 65 66 bool Dump() REQUIRES_SHARED(Locks::mutator_lock_) { 67 std::ostream& os = *os_; 68 os << "IMAGE LOCATION: " << image_location_ << "\n\n"; 69 70 os << "MAGIC: " << image_header_.GetMagic() << "\n\n"; 71 72 os << "IMAGE BEGIN: " << reinterpret_cast<void*>(image_header_.GetImageBegin()) << "\n\n"; 73 74 bool ret = true; 75 if (image_diff_pid_ >= 0) { 76 os << "IMAGE DIFF PID (" << image_diff_pid_ << "): "; 77 ret = DumpImageDiff(image_diff_pid_, zygote_diff_pid_); 78 os << "\n\n"; 79 } else { 80 os << "IMAGE DIFF PID: disabled\n\n"; 81 } 82 83 os << std::flush; 84 85 return ret; 86 } 87 88 private: 89 static bool EndsWith(const std::string& str, const std::string& suffix) { 90 return str.size() >= suffix.size() && 91 str.compare(str.size() - suffix.size(), suffix.size(), suffix) == 0; 92 } 93 94 // Return suffix of the file path after the last /. (e.g. /foo/bar -> bar, bar -> bar) 95 static std::string BaseName(const std::string& str) { 96 size_t idx = str.rfind('/'); 97 if (idx == std::string::npos) { 98 return str; 99 } 100 101 return str.substr(idx + 1); 102 } 103 104 bool DumpImageDiff(pid_t image_diff_pid, pid_t zygote_diff_pid) 105 REQUIRES_SHARED(Locks::mutator_lock_) { 106 std::ostream& os = *os_; 107 108 { 109 struct stat sts; 110 std::string proc_pid_str = 111 StringPrintf("/proc/%ld", static_cast<long>(image_diff_pid)); // NOLINT [runtime/int] 112 if (stat(proc_pid_str.c_str(), &sts) == -1) { 113 os << "Process does not exist"; 114 return false; 115 } 116 } 117 118 // Open /proc/$pid/maps to view memory maps 119 auto proc_maps = std::unique_ptr<BacktraceMap>(BacktraceMap::Create(image_diff_pid)); 120 if (proc_maps == nullptr) { 121 os << "Could not read backtrace maps"; 122 return false; 123 } 124 125 bool found_boot_map = false; 126 backtrace_map_t boot_map = backtrace_map_t(); 127 // Find the memory map only for boot.art 128 for (const backtrace_map_t& map : *proc_maps) { 129 if (EndsWith(map.name, GetImageLocationBaseName())) { 130 if ((map.flags & PROT_WRITE) != 0) { 131 boot_map = map; 132 found_boot_map = true; 133 break; 134 } 135 // In actuality there's more than 1 map, but the second one is read-only. 136 // The one we care about is the write-able map. 137 // The readonly maps are guaranteed to be identical, so its not interesting to compare 138 // them. 139 } 140 } 141 142 if (!found_boot_map) { 143 os << "Could not find map for " << GetImageLocationBaseName(); 144 return false; 145 } 146 147 // Future idea: diff against zygote so we can ignore the shared dirty pages. 148 return DumpImageDiffMap(image_diff_pid, zygote_diff_pid, boot_map); 149 } 150 151 static std::string PrettyFieldValue(ArtField* field, mirror::Object* obj) 152 REQUIRES_SHARED(Locks::mutator_lock_) { 153 std::ostringstream oss; 154 switch (field->GetTypeAsPrimitiveType()) { 155 case Primitive::kPrimNot: { 156 oss << obj->GetFieldObject<mirror::Object, kVerifyNone, kWithoutReadBarrier>( 157 field->GetOffset()); 158 break; 159 } 160 case Primitive::kPrimBoolean: { 161 oss << static_cast<bool>(obj->GetFieldBoolean<kVerifyNone>(field->GetOffset())); 162 break; 163 } 164 case Primitive::kPrimByte: { 165 oss << static_cast<int32_t>(obj->GetFieldByte<kVerifyNone>(field->GetOffset())); 166 break; 167 } 168 case Primitive::kPrimChar: { 169 oss << obj->GetFieldChar<kVerifyNone>(field->GetOffset()); 170 break; 171 } 172 case Primitive::kPrimShort: { 173 oss << obj->GetFieldShort<kVerifyNone>(field->GetOffset()); 174 break; 175 } 176 case Primitive::kPrimInt: { 177 oss << obj->GetField32<kVerifyNone>(field->GetOffset()); 178 break; 179 } 180 case Primitive::kPrimLong: { 181 oss << obj->GetField64<kVerifyNone>(field->GetOffset()); 182 break; 183 } 184 case Primitive::kPrimFloat: { 185 oss << obj->GetField32<kVerifyNone>(field->GetOffset()); 186 break; 187 } 188 case Primitive::kPrimDouble: { 189 oss << obj->GetField64<kVerifyNone>(field->GetOffset()); 190 break; 191 } 192 case Primitive::kPrimVoid: { 193 oss << "void"; 194 break; 195 } 196 } 197 return oss.str(); 198 } 199 200 // Aggregate and detail class data from an image diff. 201 struct ClassData { 202 int dirty_object_count = 0; 203 204 // Track only the byte-per-byte dirtiness (in bytes) 205 int dirty_object_byte_count = 0; 206 207 // Track the object-by-object dirtiness (in bytes) 208 int dirty_object_size_in_bytes = 0; 209 210 int clean_object_count = 0; 211 212 std::string descriptor; 213 214 int false_dirty_byte_count = 0; 215 int false_dirty_object_count = 0; 216 std::vector<mirror::Object*> false_dirty_objects; 217 218 // Remote pointers to dirty objects 219 std::vector<mirror::Object*> dirty_objects; 220 }; 221 222 void DiffObjectContents(mirror::Object* obj, 223 uint8_t* remote_bytes, 224 std::ostream& os) REQUIRES_SHARED(Locks::mutator_lock_) { 225 const char* tabs = " "; 226 // Attempt to find fields for all dirty bytes. 227 mirror::Class* klass = obj->GetClass(); 228 if (obj->IsClass()) { 229 os << tabs << "Class " << mirror::Class::PrettyClass(obj->AsClass()) << " " << obj << "\n"; 230 } else { 231 os << tabs << "Instance of " << mirror::Class::PrettyClass(klass) << " " << obj << "\n"; 232 } 233 234 std::unordered_set<ArtField*> dirty_instance_fields; 235 std::unordered_set<ArtField*> dirty_static_fields; 236 const uint8_t* obj_bytes = reinterpret_cast<const uint8_t*>(obj); 237 mirror::Object* remote_obj = reinterpret_cast<mirror::Object*>(remote_bytes); 238 for (size_t i = 0, count = obj->SizeOf(); i < count; ++i) { 239 if (obj_bytes[i] != remote_bytes[i]) { 240 ArtField* field = ArtField::FindInstanceFieldWithOffset</*exact*/false>(klass, i); 241 if (field != nullptr) { 242 dirty_instance_fields.insert(field); 243 } else if (obj->IsClass()) { 244 field = ArtField::FindStaticFieldWithOffset</*exact*/false>(obj->AsClass(), i); 245 if (field != nullptr) { 246 dirty_static_fields.insert(field); 247 } 248 } 249 if (field == nullptr) { 250 if (klass->IsArrayClass()) { 251 mirror::Class* component_type = klass->GetComponentType(); 252 Primitive::Type primitive_type = component_type->GetPrimitiveType(); 253 size_t component_size = Primitive::ComponentSize(primitive_type); 254 size_t data_offset = mirror::Array::DataOffset(component_size).Uint32Value(); 255 if (i >= data_offset) { 256 os << tabs << "Dirty array element " << (i - data_offset) / component_size << "\n"; 257 // Skip to next element to prevent spam. 258 i += component_size - 1; 259 continue; 260 } 261 } 262 os << tabs << "No field for byte offset " << i << "\n"; 263 } 264 } 265 } 266 // Dump different fields. TODO: Dump field contents. 267 if (!dirty_instance_fields.empty()) { 268 os << tabs << "Dirty instance fields " << dirty_instance_fields.size() << "\n"; 269 for (ArtField* field : dirty_instance_fields) { 270 os << tabs << ArtField::PrettyField(field) 271 << " original=" << PrettyFieldValue(field, obj) 272 << " remote=" << PrettyFieldValue(field, remote_obj) << "\n"; 273 } 274 } 275 if (!dirty_static_fields.empty()) { 276 os << tabs << "Dirty static fields " << dirty_static_fields.size() << "\n"; 277 for (ArtField* field : dirty_static_fields) { 278 os << tabs << ArtField::PrettyField(field) 279 << " original=" << PrettyFieldValue(field, obj) 280 << " remote=" << PrettyFieldValue(field, remote_obj) << "\n"; 281 } 282 } 283 os << "\n"; 284 } 285 286 // Look at /proc/$pid/mem and only diff the things from there 287 bool DumpImageDiffMap(pid_t image_diff_pid, 288 pid_t zygote_diff_pid, 289 const backtrace_map_t& boot_map) 290 REQUIRES_SHARED(Locks::mutator_lock_) { 291 std::ostream& os = *os_; 292 const PointerSize pointer_size = InstructionSetPointerSize( 293 Runtime::Current()->GetInstructionSet()); 294 295 std::string file_name = 296 StringPrintf("/proc/%ld/mem", static_cast<long>(image_diff_pid)); // NOLINT [runtime/int] 297 298 size_t boot_map_size = boot_map.end - boot_map.start; 299 300 // Open /proc/$pid/mem as a file 301 auto map_file = std::unique_ptr<File>(OS::OpenFileForReading(file_name.c_str())); 302 if (map_file == nullptr) { 303 os << "Failed to open " << file_name << " for reading"; 304 return false; 305 } 306 307 // Memory-map /proc/$pid/mem subset from the boot map 308 CHECK(boot_map.end >= boot_map.start); 309 310 std::string error_msg; 311 312 // Walk the bytes and diff against our boot image 313 const ImageHeader& boot_image_header = image_header_; 314 315 os << "\nObserving boot image header at address " 316 << reinterpret_cast<const void*>(&boot_image_header) 317 << "\n\n"; 318 319 const uint8_t* image_begin_unaligned = boot_image_header.GetImageBegin(); 320 const uint8_t* image_mirror_end_unaligned = image_begin_unaligned + 321 boot_image_header.GetImageSection(ImageHeader::kSectionObjects).Size(); 322 const uint8_t* image_end_unaligned = image_begin_unaligned + boot_image_header.GetImageSize(); 323 324 // Adjust range to nearest page 325 const uint8_t* image_begin = AlignDown(image_begin_unaligned, kPageSize); 326 const uint8_t* image_end = AlignUp(image_end_unaligned, kPageSize); 327 328 ptrdiff_t page_off_begin = boot_image_header.GetImageBegin() - image_begin; 329 330 if (reinterpret_cast<uintptr_t>(image_begin) > boot_map.start || 331 reinterpret_cast<uintptr_t>(image_end) < boot_map.end) { 332 // Sanity check that we aren't trying to read a completely different boot image 333 os << "Remote boot map is out of range of local boot map: " << 334 "local begin " << reinterpret_cast<const void*>(image_begin) << 335 ", local end " << reinterpret_cast<const void*>(image_end) << 336 ", remote begin " << reinterpret_cast<const void*>(boot_map.start) << 337 ", remote end " << reinterpret_cast<const void*>(boot_map.end); 338 return false; 339 // If we wanted even more validation we could map the ImageHeader from the file 340 } 341 342 std::vector<uint8_t> remote_contents(boot_map_size); 343 if (!map_file->PreadFully(&remote_contents[0], boot_map_size, boot_map.start)) { 344 os << "Could not fully read file " << file_name; 345 return false; 346 } 347 348 std::vector<uint8_t> zygote_contents; 349 std::unique_ptr<File> zygote_map_file; 350 if (zygote_diff_pid != -1) { 351 std::string zygote_file_name = 352 StringPrintf("/proc/%ld/mem", static_cast<long>(zygote_diff_pid)); // NOLINT [runtime/int] 353 zygote_map_file.reset(OS::OpenFileForReading(zygote_file_name.c_str())); 354 // The boot map should be at the same address. 355 zygote_contents.resize(boot_map_size); 356 if (!zygote_map_file->PreadFully(&zygote_contents[0], boot_map_size, boot_map.start)) { 357 LOG(WARNING) << "Could not fully read zygote file " << zygote_file_name; 358 zygote_contents.clear(); 359 } 360 } 361 362 std::string page_map_file_name = StringPrintf( 363 "/proc/%ld/pagemap", static_cast<long>(image_diff_pid)); // NOLINT [runtime/int] 364 auto page_map_file = std::unique_ptr<File>(OS::OpenFileForReading(page_map_file_name.c_str())); 365 if (page_map_file == nullptr) { 366 os << "Failed to open " << page_map_file_name << " for reading: " << strerror(errno); 367 return false; 368 } 369 370 // Not truly clean, mmap-ing boot.art again would be more pristine, but close enough 371 const char* clean_page_map_file_name = "/proc/self/pagemap"; 372 auto clean_page_map_file = std::unique_ptr<File>( 373 OS::OpenFileForReading(clean_page_map_file_name)); 374 if (clean_page_map_file == nullptr) { 375 os << "Failed to open " << clean_page_map_file_name << " for reading: " << strerror(errno); 376 return false; 377 } 378 379 auto kpage_flags_file = std::unique_ptr<File>(OS::OpenFileForReading("/proc/kpageflags")); 380 if (kpage_flags_file == nullptr) { 381 os << "Failed to open /proc/kpageflags for reading: " << strerror(errno); 382 return false; 383 } 384 385 auto kpage_count_file = std::unique_ptr<File>(OS::OpenFileForReading("/proc/kpagecount")); 386 if (kpage_count_file == nullptr) { 387 os << "Failed to open /proc/kpagecount for reading:" << strerror(errno); 388 return false; 389 } 390 391 // Set of the remote virtual page indices that are dirty 392 std::set<size_t> dirty_page_set_remote; 393 // Set of the local virtual page indices that are dirty 394 std::set<size_t> dirty_page_set_local; 395 396 size_t different_int32s = 0; 397 size_t different_bytes = 0; 398 size_t different_pages = 0; 399 size_t virtual_page_idx = 0; // Virtual page number (for an absolute memory address) 400 size_t page_idx = 0; // Page index relative to 0 401 size_t previous_page_idx = 0; // Previous page index relative to 0 402 size_t dirty_pages = 0; 403 size_t private_pages = 0; 404 size_t private_dirty_pages = 0; 405 406 // Iterate through one page at a time. Boot map begin/end already implicitly aligned. 407 for (uintptr_t begin = boot_map.start; begin != boot_map.end; begin += kPageSize) { 408 ptrdiff_t offset = begin - boot_map.start; 409 410 // We treat the image header as part of the memory map for now 411 // If we wanted to change this, we could pass base=start+sizeof(ImageHeader) 412 // But it might still be interesting to see if any of the ImageHeader data mutated 413 const uint8_t* local_ptr = reinterpret_cast<const uint8_t*>(&boot_image_header) + offset; 414 uint8_t* remote_ptr = &remote_contents[offset]; 415 416 if (memcmp(local_ptr, remote_ptr, kPageSize) != 0) { 417 different_pages++; 418 419 // Count the number of 32-bit integers that are different. 420 for (size_t i = 0; i < kPageSize / sizeof(uint32_t); ++i) { 421 uint32_t* remote_ptr_int32 = reinterpret_cast<uint32_t*>(remote_ptr); 422 const uint32_t* local_ptr_int32 = reinterpret_cast<const uint32_t*>(local_ptr); 423 424 if (remote_ptr_int32[i] != local_ptr_int32[i]) { 425 different_int32s++; 426 } 427 } 428 } 429 } 430 431 // Iterate through one byte at a time. 432 for (uintptr_t begin = boot_map.start; begin != boot_map.end; ++begin) { 433 previous_page_idx = page_idx; 434 ptrdiff_t offset = begin - boot_map.start; 435 436 // We treat the image header as part of the memory map for now 437 // If we wanted to change this, we could pass base=start+sizeof(ImageHeader) 438 // But it might still be interesting to see if any of the ImageHeader data mutated 439 const uint8_t* local_ptr = reinterpret_cast<const uint8_t*>(&boot_image_header) + offset; 440 uint8_t* remote_ptr = &remote_contents[offset]; 441 442 virtual_page_idx = reinterpret_cast<uintptr_t>(local_ptr) / kPageSize; 443 444 // Calculate the page index, relative to the 0th page where the image begins 445 page_idx = (offset + page_off_begin) / kPageSize; 446 if (*local_ptr != *remote_ptr) { 447 // Track number of bytes that are different 448 different_bytes++; 449 } 450 451 // Independently count the # of dirty pages on the remote side 452 size_t remote_virtual_page_idx = begin / kPageSize; 453 if (previous_page_idx != page_idx) { 454 uint64_t page_count = 0xC0FFEE; 455 // TODO: virtual_page_idx needs to be from the same process 456 int dirtiness = (IsPageDirty(page_map_file.get(), // Image-diff-pid procmap 457 clean_page_map_file.get(), // Self procmap 458 kpage_flags_file.get(), 459 kpage_count_file.get(), 460 remote_virtual_page_idx, // potentially "dirty" page 461 virtual_page_idx, // true "clean" page 462 &page_count, 463 &error_msg)); 464 if (dirtiness < 0) { 465 os << error_msg; 466 return false; 467 } else if (dirtiness > 0) { 468 dirty_pages++; 469 dirty_page_set_remote.insert(dirty_page_set_remote.end(), remote_virtual_page_idx); 470 dirty_page_set_local.insert(dirty_page_set_local.end(), virtual_page_idx); 471 } 472 473 bool is_dirty = dirtiness > 0; 474 bool is_private = page_count == 1; 475 476 if (page_count == 1) { 477 private_pages++; 478 } 479 480 if (is_dirty && is_private) { 481 private_dirty_pages++; 482 } 483 } 484 } 485 486 std::map<mirror::Class*, ClassData> class_data; 487 488 // Walk each object in the remote image space and compare it against ours 489 size_t different_objects = 0; 490 491 std::map<off_t /* field offset */, int /* count */> art_method_field_dirty_count; 492 std::vector<ArtMethod*> art_method_dirty_objects; 493 494 std::map<off_t /* field offset */, int /* count */> class_field_dirty_count; 495 std::vector<mirror::Class*> class_dirty_objects; 496 497 // List of local objects that are clean, but located on dirty pages. 498 std::vector<mirror::Object*> false_dirty_objects; 499 size_t false_dirty_object_bytes = 0; 500 501 // Look up remote classes by their descriptor 502 std::map<std::string, mirror::Class*> remote_class_map; 503 // Look up local classes by their descriptor 504 std::map<std::string, mirror::Class*> local_class_map; 505 506 // Objects that are dirty against the image (possibly shared or private dirty). 507 std::set<mirror::Object*> image_dirty_objects; 508 509 // Objects that are dirty against the zygote (probably private dirty). 510 std::set<mirror::Object*> zygote_dirty_objects; 511 512 size_t dirty_object_bytes = 0; 513 const uint8_t* begin_image_ptr = image_begin_unaligned; 514 const uint8_t* end_image_ptr = image_mirror_end_unaligned; 515 516 const uint8_t* current = begin_image_ptr + RoundUp(sizeof(ImageHeader), kObjectAlignment); 517 while (reinterpret_cast<uintptr_t>(current) < reinterpret_cast<uintptr_t>(end_image_ptr)) { 518 CHECK_ALIGNED(current, kObjectAlignment); 519 mirror::Object* obj = reinterpret_cast<mirror::Object*>(const_cast<uint8_t*>(current)); 520 521 // Sanity check that we are reading a real object 522 CHECK(obj->GetClass() != nullptr) << "Image object at address " << obj << " has null class"; 523 if (kUseBakerReadBarrier) { 524 obj->AssertReadBarrierState(); 525 } 526 527 // Iterate every page this object belongs to 528 bool on_dirty_page = false; 529 size_t page_off = 0; 530 size_t current_page_idx; 531 uintptr_t object_address; 532 do { 533 object_address = reinterpret_cast<uintptr_t>(current); 534 current_page_idx = object_address / kPageSize + page_off; 535 536 if (dirty_page_set_local.find(current_page_idx) != dirty_page_set_local.end()) { 537 // This object is on a dirty page 538 on_dirty_page = true; 539 } 540 541 page_off++; 542 } while ((current_page_idx * kPageSize) < 543 RoundUp(object_address + obj->SizeOf(), kObjectAlignment)); 544 545 mirror::Class* klass = obj->GetClass(); 546 547 // Check against the other object and see if they are different 548 ptrdiff_t offset = current - begin_image_ptr; 549 const uint8_t* current_remote = &remote_contents[offset]; 550 mirror::Object* remote_obj = reinterpret_cast<mirror::Object*>( 551 const_cast<uint8_t*>(current_remote)); 552 553 bool different_image_object = memcmp(current, current_remote, obj->SizeOf()) != 0; 554 if (different_image_object) { 555 bool different_zygote_object = false; 556 if (!zygote_contents.empty()) { 557 const uint8_t* zygote_ptr = &zygote_contents[offset]; 558 different_zygote_object = memcmp(current, zygote_ptr, obj->SizeOf()) != 0; 559 } 560 if (different_zygote_object) { 561 // Different from zygote. 562 zygote_dirty_objects.insert(obj); 563 } else { 564 // Just different from iamge. 565 image_dirty_objects.insert(obj); 566 } 567 568 different_objects++; 569 dirty_object_bytes += obj->SizeOf(); 570 571 ++class_data[klass].dirty_object_count; 572 573 // Go byte-by-byte and figure out what exactly got dirtied 574 size_t dirty_byte_count_per_object = 0; 575 for (size_t i = 0; i < obj->SizeOf(); ++i) { 576 if (current[i] != current_remote[i]) { 577 dirty_byte_count_per_object++; 578 } 579 } 580 class_data[klass].dirty_object_byte_count += dirty_byte_count_per_object; 581 class_data[klass].dirty_object_size_in_bytes += obj->SizeOf(); 582 class_data[klass].dirty_objects.push_back(remote_obj); 583 } else { 584 ++class_data[klass].clean_object_count; 585 } 586 587 std::string descriptor = GetClassDescriptor(klass); 588 if (different_image_object) { 589 if (klass->IsClassClass()) { 590 // this is a "Class" 591 mirror::Class* obj_as_class = reinterpret_cast<mirror::Class*>(remote_obj); 592 593 // print the fields that are dirty 594 for (size_t i = 0; i < obj->SizeOf(); ++i) { 595 if (current[i] != current_remote[i]) { 596 class_field_dirty_count[i]++; 597 } 598 } 599 600 class_dirty_objects.push_back(obj_as_class); 601 } else if (strcmp(descriptor.c_str(), "Ljava/lang/reflect/ArtMethod;") == 0) { 602 // this is an ArtMethod 603 ArtMethod* art_method = reinterpret_cast<ArtMethod*>(remote_obj); 604 605 // print the fields that are dirty 606 for (size_t i = 0; i < obj->SizeOf(); ++i) { 607 if (current[i] != current_remote[i]) { 608 art_method_field_dirty_count[i]++; 609 } 610 } 611 612 art_method_dirty_objects.push_back(art_method); 613 } 614 } else if (on_dirty_page) { 615 // This object was either never mutated or got mutated back to the same value. 616 // TODO: Do I want to distinguish a "different" vs a "dirty" page here? 617 false_dirty_objects.push_back(obj); 618 class_data[klass].false_dirty_objects.push_back(obj); 619 false_dirty_object_bytes += obj->SizeOf(); 620 class_data[obj->GetClass()].false_dirty_byte_count += obj->SizeOf(); 621 class_data[obj->GetClass()].false_dirty_object_count += 1; 622 } 623 624 if (strcmp(descriptor.c_str(), "Ljava/lang/Class;") == 0) { 625 local_class_map[descriptor] = reinterpret_cast<mirror::Class*>(obj); 626 remote_class_map[descriptor] = reinterpret_cast<mirror::Class*>(remote_obj); 627 } 628 629 // Unconditionally store the class descriptor in case we need it later 630 class_data[klass].descriptor = descriptor; 631 current += RoundUp(obj->SizeOf(), kObjectAlignment); 632 } 633 634 // Looking at only dirty pages, figure out how many of those bytes belong to dirty objects. 635 float true_dirtied_percent = dirty_object_bytes * 1.0f / (dirty_pages * kPageSize); 636 size_t false_dirty_pages = dirty_pages - different_pages; 637 638 os << "Mapping at [" << reinterpret_cast<void*>(boot_map.start) << ", " 639 << reinterpret_cast<void*>(boot_map.end) << ") had: \n " 640 << different_bytes << " differing bytes, \n " 641 << different_int32s << " differing int32s, \n " 642 << different_objects << " different objects, \n " 643 << dirty_object_bytes << " different object [bytes], \n " 644 << false_dirty_objects.size() << " false dirty objects,\n " 645 << false_dirty_object_bytes << " false dirty object [bytes], \n " 646 << true_dirtied_percent << " different objects-vs-total in a dirty page;\n " 647 << different_pages << " different pages; \n " 648 << dirty_pages << " pages are dirty; \n " 649 << false_dirty_pages << " pages are false dirty; \n " 650 << private_pages << " pages are private; \n " 651 << private_dirty_pages << " pages are Private_Dirty\n " 652 << ""; 653 654 // vector of pairs (int count, Class*) 655 auto dirty_object_class_values = SortByValueDesc<mirror::Class*, int, ClassData>( 656 class_data, [](const ClassData& d) { return d.dirty_object_count; }); 657 auto clean_object_class_values = SortByValueDesc<mirror::Class*, int, ClassData>( 658 class_data, [](const ClassData& d) { return d.clean_object_count; }); 659 660 if (!zygote_dirty_objects.empty()) { 661 os << "\n" << " Dirty objects compared to zygote (probably private dirty): " 662 << zygote_dirty_objects.size() << "\n"; 663 for (mirror::Object* obj : zygote_dirty_objects) { 664 const uint8_t* obj_bytes = reinterpret_cast<const uint8_t*>(obj); 665 ptrdiff_t offset = obj_bytes - begin_image_ptr; 666 uint8_t* remote_bytes = &zygote_contents[offset]; 667 DiffObjectContents(obj, remote_bytes, os); 668 } 669 } 670 os << "\n" << " Dirty objects compared to image (private or shared dirty): " 671 << image_dirty_objects.size() << "\n"; 672 for (mirror::Object* obj : image_dirty_objects) { 673 const uint8_t* obj_bytes = reinterpret_cast<const uint8_t*>(obj); 674 ptrdiff_t offset = obj_bytes - begin_image_ptr; 675 uint8_t* remote_bytes = &remote_contents[offset]; 676 DiffObjectContents(obj, remote_bytes, os); 677 } 678 679 os << "\n" << " Dirty object count by class:\n"; 680 for (const auto& vk_pair : dirty_object_class_values) { 681 int dirty_object_count = vk_pair.first; 682 mirror::Class* klass = vk_pair.second; 683 int object_sizes = class_data[klass].dirty_object_size_in_bytes; 684 float avg_dirty_bytes_per_class = 685 class_data[klass].dirty_object_byte_count * 1.0f / object_sizes; 686 float avg_object_size = object_sizes * 1.0f / dirty_object_count; 687 const std::string& descriptor = class_data[klass].descriptor; 688 os << " " << mirror::Class::PrettyClass(klass) << " (" 689 << "objects: " << dirty_object_count << ", " 690 << "avg dirty bytes: " << avg_dirty_bytes_per_class << ", " 691 << "avg object size: " << avg_object_size << ", " 692 << "class descriptor: '" << descriptor << "'" 693 << ")\n"; 694 695 constexpr size_t kMaxAddressPrint = 5; 696 if (strcmp(descriptor.c_str(), "Ljava/lang/reflect/ArtMethod;") == 0) { 697 os << " sample object addresses: "; 698 for (size_t i = 0; i < art_method_dirty_objects.size() && i < kMaxAddressPrint; ++i) { 699 auto art_method = art_method_dirty_objects[i]; 700 701 os << reinterpret_cast<void*>(art_method) << ", "; 702 } 703 os << "\n"; 704 705 os << " dirty byte +offset:count list = "; 706 auto art_method_field_dirty_count_sorted = 707 SortByValueDesc<off_t, int, int>(art_method_field_dirty_count); 708 for (auto pair : art_method_field_dirty_count_sorted) { 709 off_t offset = pair.second; 710 int count = pair.first; 711 712 os << "+" << offset << ":" << count << ", "; 713 } 714 715 os << "\n"; 716 717 os << " field contents:\n"; 718 const auto& dirty_objects_list = class_data[klass].dirty_objects; 719 for (mirror::Object* obj : dirty_objects_list) { 720 // remote method 721 auto art_method = reinterpret_cast<ArtMethod*>(obj); 722 723 // remote class 724 mirror::Class* remote_declaring_class = 725 FixUpRemotePointer(art_method->GetDeclaringClass(), remote_contents, boot_map); 726 727 // local class 728 mirror::Class* declaring_class = 729 RemoteContentsPointerToLocal(remote_declaring_class, 730 remote_contents, 731 boot_image_header); 732 733 os << " " << reinterpret_cast<void*>(obj) << " "; 734 os << " entryPointFromJni: " 735 << reinterpret_cast<const void*>( 736 art_method->GetDataPtrSize(pointer_size)) << ", "; 737 os << " entryPointFromQuickCompiledCode: " 738 << reinterpret_cast<const void*>( 739 art_method->GetEntryPointFromQuickCompiledCodePtrSize(pointer_size)) 740 << ", "; 741 os << " isNative? " << (art_method->IsNative() ? "yes" : "no") << ", "; 742 os << " class_status (local): " << declaring_class->GetStatus(); 743 os << " class_status (remote): " << remote_declaring_class->GetStatus(); 744 os << "\n"; 745 } 746 } 747 if (strcmp(descriptor.c_str(), "Ljava/lang/Class;") == 0) { 748 os << " sample object addresses: "; 749 for (size_t i = 0; i < class_dirty_objects.size() && i < kMaxAddressPrint; ++i) { 750 auto class_ptr = class_dirty_objects[i]; 751 752 os << reinterpret_cast<void*>(class_ptr) << ", "; 753 } 754 os << "\n"; 755 756 os << " dirty byte +offset:count list = "; 757 auto class_field_dirty_count_sorted = 758 SortByValueDesc<off_t, int, int>(class_field_dirty_count); 759 for (auto pair : class_field_dirty_count_sorted) { 760 off_t offset = pair.second; 761 int count = pair.first; 762 763 os << "+" << offset << ":" << count << ", "; 764 } 765 os << "\n"; 766 767 os << " field contents:\n"; 768 const auto& dirty_objects_list = class_data[klass].dirty_objects; 769 for (mirror::Object* obj : dirty_objects_list) { 770 // remote class object 771 auto remote_klass = reinterpret_cast<mirror::Class*>(obj); 772 773 // local class object 774 auto local_klass = RemoteContentsPointerToLocal(remote_klass, 775 remote_contents, 776 boot_image_header); 777 778 os << " " << reinterpret_cast<void*>(obj) << " "; 779 os << " class_status (remote): " << remote_klass->GetStatus() << ", "; 780 os << " class_status (local): " << local_klass->GetStatus(); 781 os << "\n"; 782 } 783 } 784 } 785 786 auto false_dirty_object_class_values = SortByValueDesc<mirror::Class*, int, ClassData>( 787 class_data, [](const ClassData& d) { return d.false_dirty_object_count; }); 788 789 os << "\n" << " False-dirty object count by class:\n"; 790 for (const auto& vk_pair : false_dirty_object_class_values) { 791 int object_count = vk_pair.first; 792 mirror::Class* klass = vk_pair.second; 793 int object_sizes = class_data[klass].false_dirty_byte_count; 794 float avg_object_size = object_sizes * 1.0f / object_count; 795 const std::string& descriptor = class_data[klass].descriptor; 796 os << " " << mirror::Class::PrettyClass(klass) << " (" 797 << "objects: " << object_count << ", " 798 << "avg object size: " << avg_object_size << ", " 799 << "total bytes: " << object_sizes << ", " 800 << "class descriptor: '" << descriptor << "'" 801 << ")\n"; 802 803 if (strcmp(descriptor.c_str(), "Ljava/lang/reflect/ArtMethod;") == 0) { 804 auto& art_method_false_dirty_objects = class_data[klass].false_dirty_objects; 805 806 os << " field contents:\n"; 807 for (mirror::Object* obj : art_method_false_dirty_objects) { 808 // local method 809 auto art_method = reinterpret_cast<ArtMethod*>(obj); 810 811 // local class 812 mirror::Class* declaring_class = art_method->GetDeclaringClass(); 813 814 os << " " << reinterpret_cast<void*>(obj) << " "; 815 os << " entryPointFromJni: " 816 << reinterpret_cast<const void*>( 817 art_method->GetDataPtrSize(pointer_size)) << ", "; 818 os << " entryPointFromQuickCompiledCode: " 819 << reinterpret_cast<const void*>( 820 art_method->GetEntryPointFromQuickCompiledCodePtrSize(pointer_size)) 821 << ", "; 822 os << " isNative? " << (art_method->IsNative() ? "yes" : "no") << ", "; 823 os << " class_status (local): " << declaring_class->GetStatus(); 824 os << "\n"; 825 } 826 } 827 } 828 829 os << "\n" << " Clean object count by class:\n"; 830 for (const auto& vk_pair : clean_object_class_values) { 831 os << " " << mirror::Class::PrettyClass(vk_pair.second) << " (" << vk_pair.first << ")\n"; 832 } 833 834 return true; 835 } 836 837 // Fixup a remote pointer that we read from a foreign boot.art to point to our own memory. 838 // Returned pointer will point to inside of remote_contents. 839 template <typename T> 840 static T* FixUpRemotePointer(T* remote_ptr, 841 std::vector<uint8_t>& remote_contents, 842 const backtrace_map_t& boot_map) { 843 if (remote_ptr == nullptr) { 844 return nullptr; 845 } 846 847 uintptr_t remote = reinterpret_cast<uintptr_t>(remote_ptr); 848 849 CHECK_LE(boot_map.start, remote); 850 CHECK_GT(boot_map.end, remote); 851 852 off_t boot_offset = remote - boot_map.start; 853 854 return reinterpret_cast<T*>(&remote_contents[boot_offset]); 855 } 856 857 template <typename T> 858 static T* RemoteContentsPointerToLocal(T* remote_ptr, 859 std::vector<uint8_t>& remote_contents, 860 const ImageHeader& image_header) { 861 if (remote_ptr == nullptr) { 862 return nullptr; 863 } 864 865 uint8_t* remote = reinterpret_cast<uint8_t*>(remote_ptr); 866 ptrdiff_t boot_offset = remote - &remote_contents[0]; 867 868 const uint8_t* local_ptr = reinterpret_cast<const uint8_t*>(&image_header) + boot_offset; 869 870 return reinterpret_cast<T*>(const_cast<uint8_t*>(local_ptr)); 871 } 872 873 static std::string GetClassDescriptor(mirror::Class* klass) 874 REQUIRES_SHARED(Locks::mutator_lock_) { 875 CHECK(klass != nullptr); 876 877 std::string descriptor; 878 const char* descriptor_str = klass->GetDescriptor(&descriptor); 879 880 return std::string(descriptor_str); 881 } 882 883 template <typename K, typename V, typename D> 884 static std::vector<std::pair<V, K>> SortByValueDesc( 885 const std::map<K, D> map, 886 std::function<V(const D&)> value_mapper = [](const D& d) { return static_cast<V>(d); }) { 887 // Store value->key so that we can use the default sort from pair which 888 // sorts by value first and then key 889 std::vector<std::pair<V, K>> value_key_vector; 890 891 for (const auto& kv_pair : map) { 892 value_key_vector.push_back(std::make_pair(value_mapper(kv_pair.second), kv_pair.first)); 893 } 894 895 // Sort in reverse (descending order) 896 std::sort(value_key_vector.rbegin(), value_key_vector.rend()); 897 return value_key_vector; 898 } 899 900 static bool GetPageFrameNumber(File* page_map_file, 901 size_t virtual_page_index, 902 uint64_t* page_frame_number, 903 std::string* error_msg) { 904 CHECK(page_map_file != nullptr); 905 CHECK(page_frame_number != nullptr); 906 CHECK(error_msg != nullptr); 907 908 constexpr size_t kPageMapEntrySize = sizeof(uint64_t); 909 constexpr uint64_t kPageFrameNumberMask = (1ULL << 55) - 1; // bits 0-54 [in /proc/$pid/pagemap] 910 constexpr uint64_t kPageSoftDirtyMask = (1ULL << 55); // bit 55 [in /proc/$pid/pagemap] 911 912 uint64_t page_map_entry = 0; 913 914 // Read 64-bit entry from /proc/$pid/pagemap to get the physical page frame number 915 if (!page_map_file->PreadFully(&page_map_entry, kPageMapEntrySize, 916 virtual_page_index * kPageMapEntrySize)) { 917 *error_msg = StringPrintf("Failed to read the virtual page index entry from %s", 918 page_map_file->GetPath().c_str()); 919 return false; 920 } 921 922 // TODO: seems useless, remove this. 923 bool soft_dirty = (page_map_entry & kPageSoftDirtyMask) != 0; 924 if ((false)) { 925 LOG(VERBOSE) << soft_dirty; // Suppress unused warning 926 UNREACHABLE(); 927 } 928 929 *page_frame_number = page_map_entry & kPageFrameNumberMask; 930 931 return true; 932 } 933 934 static int IsPageDirty(File* page_map_file, 935 File* clean_page_map_file, 936 File* kpage_flags_file, 937 File* kpage_count_file, 938 size_t virtual_page_idx, 939 size_t clean_virtual_page_idx, 940 // Out parameters: 941 uint64_t* page_count, std::string* error_msg) { 942 CHECK(page_map_file != nullptr); 943 CHECK(clean_page_map_file != nullptr); 944 CHECK_NE(page_map_file, clean_page_map_file); 945 CHECK(kpage_flags_file != nullptr); 946 CHECK(kpage_count_file != nullptr); 947 CHECK(page_count != nullptr); 948 CHECK(error_msg != nullptr); 949 950 // Constants are from https://www.kernel.org/doc/Documentation/vm/pagemap.txt 951 952 constexpr size_t kPageFlagsEntrySize = sizeof(uint64_t); 953 constexpr size_t kPageCountEntrySize = sizeof(uint64_t); 954 constexpr uint64_t kPageFlagsDirtyMask = (1ULL << 4); // in /proc/kpageflags 955 constexpr uint64_t kPageFlagsNoPageMask = (1ULL << 20); // in /proc/kpageflags 956 constexpr uint64_t kPageFlagsMmapMask = (1ULL << 11); // in /proc/kpageflags 957 958 uint64_t page_frame_number = 0; 959 if (!GetPageFrameNumber(page_map_file, virtual_page_idx, &page_frame_number, error_msg)) { 960 return -1; 961 } 962 963 uint64_t page_frame_number_clean = 0; 964 if (!GetPageFrameNumber(clean_page_map_file, clean_virtual_page_idx, &page_frame_number_clean, 965 error_msg)) { 966 return -1; 967 } 968 969 // Read 64-bit entry from /proc/kpageflags to get the dirty bit for a page 970 uint64_t kpage_flags_entry = 0; 971 if (!kpage_flags_file->PreadFully(&kpage_flags_entry, 972 kPageFlagsEntrySize, 973 page_frame_number * kPageFlagsEntrySize)) { 974 *error_msg = StringPrintf("Failed to read the page flags from %s", 975 kpage_flags_file->GetPath().c_str()); 976 return -1; 977 } 978 979 // Read 64-bit entyry from /proc/kpagecount to get mapping counts for a page 980 if (!kpage_count_file->PreadFully(page_count /*out*/, 981 kPageCountEntrySize, 982 page_frame_number * kPageCountEntrySize)) { 983 *error_msg = StringPrintf("Failed to read the page count from %s", 984 kpage_count_file->GetPath().c_str()); 985 return -1; 986 } 987 988 // There must be a page frame at the requested address. 989 CHECK_EQ(kpage_flags_entry & kPageFlagsNoPageMask, 0u); 990 // The page frame must be memory mapped 991 CHECK_NE(kpage_flags_entry & kPageFlagsMmapMask, 0u); 992 993 // Page is dirty, i.e. has diverged from file, if the 4th bit is set to 1 994 bool flags_dirty = (kpage_flags_entry & kPageFlagsDirtyMask) != 0; 995 996 // page_frame_number_clean must come from the *same* process 997 // but a *different* mmap than page_frame_number 998 if (flags_dirty) { 999 CHECK_NE(page_frame_number, page_frame_number_clean); 1000 } 1001 1002 return page_frame_number != page_frame_number_clean; 1003 } 1004 1005 private: 1006 // Return the image location, stripped of any directories, e.g. "boot.art" or "core.art" 1007 std::string GetImageLocationBaseName() const { 1008 return BaseName(std::string(image_location_)); 1009 } 1010 1011 std::ostream* os_; 1012 const ImageHeader& image_header_; 1013 const std::string image_location_; 1014 pid_t image_diff_pid_; // Dump image diff against boot.art if pid is non-negative 1015 pid_t zygote_diff_pid_; // Dump image diff against zygote boot.art if pid is non-negative 1016 1017 DISALLOW_COPY_AND_ASSIGN(ImgDiagDumper); 1018}; 1019 1020static int DumpImage(Runtime* runtime, 1021 std::ostream* os, 1022 pid_t image_diff_pid, 1023 pid_t zygote_diff_pid) { 1024 ScopedObjectAccess soa(Thread::Current()); 1025 gc::Heap* heap = runtime->GetHeap(); 1026 std::vector<gc::space::ImageSpace*> image_spaces = heap->GetBootImageSpaces(); 1027 CHECK(!image_spaces.empty()); 1028 for (gc::space::ImageSpace* image_space : image_spaces) { 1029 const ImageHeader& image_header = image_space->GetImageHeader(); 1030 if (!image_header.IsValid()) { 1031 fprintf(stderr, "Invalid image header %s\n", image_space->GetImageLocation().c_str()); 1032 return EXIT_FAILURE; 1033 } 1034 1035 ImgDiagDumper img_diag_dumper(os, 1036 image_header, 1037 image_space->GetImageLocation(), 1038 image_diff_pid, 1039 zygote_diff_pid); 1040 if (!img_diag_dumper.Dump()) { 1041 return EXIT_FAILURE; 1042 } 1043 } 1044 return EXIT_SUCCESS; 1045} 1046 1047struct ImgDiagArgs : public CmdlineArgs { 1048 protected: 1049 using Base = CmdlineArgs; 1050 1051 virtual ParseStatus ParseCustom(const StringPiece& option, 1052 std::string* error_msg) OVERRIDE { 1053 { 1054 ParseStatus base_parse = Base::ParseCustom(option, error_msg); 1055 if (base_parse != kParseUnknownArgument) { 1056 return base_parse; 1057 } 1058 } 1059 1060 if (option.starts_with("--image-diff-pid=")) { 1061 const char* image_diff_pid = option.substr(strlen("--image-diff-pid=")).data(); 1062 1063 if (!ParseInt(image_diff_pid, &image_diff_pid_)) { 1064 *error_msg = "Image diff pid out of range"; 1065 return kParseError; 1066 } 1067 } else if (option.starts_with("--zygote-diff-pid=")) { 1068 const char* zygote_diff_pid = option.substr(strlen("--zygote-diff-pid=")).data(); 1069 1070 if (!ParseInt(zygote_diff_pid, &zygote_diff_pid_)) { 1071 *error_msg = "Zygote diff pid out of range"; 1072 return kParseError; 1073 } 1074 } else { 1075 return kParseUnknownArgument; 1076 } 1077 1078 return kParseOk; 1079 } 1080 1081 virtual ParseStatus ParseChecks(std::string* error_msg) OVERRIDE { 1082 // Perform the parent checks. 1083 ParseStatus parent_checks = Base::ParseChecks(error_msg); 1084 if (parent_checks != kParseOk) { 1085 return parent_checks; 1086 } 1087 1088 // Perform our own checks. 1089 1090 if (kill(image_diff_pid_, 1091 /*sig*/0) != 0) { // No signal is sent, perform error-checking only. 1092 // Check if the pid exists before proceeding. 1093 if (errno == ESRCH) { 1094 *error_msg = "Process specified does not exist"; 1095 } else { 1096 *error_msg = StringPrintf("Failed to check process status: %s", strerror(errno)); 1097 } 1098 return kParseError; 1099 } else if (instruction_set_ != kRuntimeISA) { 1100 // Don't allow different ISAs since the images are ISA-specific. 1101 // Right now the code assumes both the runtime ISA and the remote ISA are identical. 1102 *error_msg = "Must use the default runtime ISA; changing ISA is not supported."; 1103 return kParseError; 1104 } 1105 1106 return kParseOk; 1107 } 1108 1109 virtual std::string GetUsage() const { 1110 std::string usage; 1111 1112 usage += 1113 "Usage: imgdiag [options] ...\n" 1114 " Example: imgdiag --image-diff-pid=$(pidof dex2oat)\n" 1115 " Example: adb shell imgdiag --image-diff-pid=$(pid zygote)\n" 1116 "\n"; 1117 1118 usage += Base::GetUsage(); 1119 1120 usage += // Optional. 1121 " --image-diff-pid=<pid>: provide the PID of a process whose boot.art you want to diff.\n" 1122 " Example: --image-diff-pid=$(pid zygote)\n" 1123 " --zygote-diff-pid=<pid>: provide the PID of the zygote whose boot.art you want to diff " 1124 "against.\n" 1125 " Example: --zygote-diff-pid=$(pid zygote)\n" 1126 "\n"; 1127 1128 return usage; 1129 } 1130 1131 public: 1132 pid_t image_diff_pid_ = -1; 1133 pid_t zygote_diff_pid_ = -1; 1134}; 1135 1136struct ImgDiagMain : public CmdlineMain<ImgDiagArgs> { 1137 virtual bool ExecuteWithRuntime(Runtime* runtime) { 1138 CHECK(args_ != nullptr); 1139 1140 return DumpImage(runtime, 1141 args_->os_, 1142 args_->image_diff_pid_, 1143 args_->zygote_diff_pid_) == EXIT_SUCCESS; 1144 } 1145}; 1146 1147} // namespace art 1148 1149int main(int argc, char** argv) { 1150 art::ImgDiagMain main; 1151 return main.Main(argc, argv); 1152} 1153