1 /* 2 * Copyright (C) 2013 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 #define _GNU_SOURCE 1 18 #include <dirent.h> 19 #include <dlfcn.h> 20 #include <errno.h> 21 #include <fcntl.h> 22 #include <inttypes.h> 23 #include <pthread.h> 24 #include <signal.h> 25 #include <stdint.h> 26 #include <stdio.h> 27 #include <stdlib.h> 28 #include <string.h> 29 #include <sys/ptrace.h> 30 #include <sys/stat.h> 31 #include <sys/types.h> 32 #include <sys/wait.h> 33 #include <time.h> 34 #include <unistd.h> 35 36 #include <algorithm> 37 #include <list> 38 #include <memory> 39 #include <string> 40 #include <vector> 41 42 #include <backtrace/Backtrace.h> 43 #include <backtrace/BacktraceMap.h> 44 45 #include <android-base/stringprintf.h> 46 #include <cutils/atomic.h> 47 #include <cutils/threads.h> 48 49 #include <gtest/gtest.h> 50 51 // For the THREAD_SIGNAL definition. 52 #include "BacktraceCurrent.h" 53 #include "thread_utils.h" 54 55 // Number of microseconds per milliseconds. 56 #define US_PER_MSEC 1000 57 58 // Number of nanoseconds in a second. 59 #define NS_PER_SEC 1000000000ULL 60 61 // Number of simultaneous dumping operations to perform. 62 #define NUM_THREADS 40 63 64 // Number of simultaneous threads running in our forked process. 65 #define NUM_PTRACE_THREADS 5 66 67 struct thread_t { 68 pid_t tid; 69 int32_t state; 70 pthread_t threadId; 71 void* data; 72 }; 73 74 struct dump_thread_t { 75 thread_t thread; 76 Backtrace* backtrace; 77 int32_t* now; 78 int32_t done; 79 }; 80 81 extern "C" { 82 // Prototypes for functions in the test library. 83 int test_level_one(int, int, int, int, void (*)(void*), void*); 84 85 int test_recursive_call(int, void (*)(void*), void*); 86 } 87 88 uint64_t NanoTime() { 89 struct timespec t = { 0, 0 }; 90 clock_gettime(CLOCK_MONOTONIC, &t); 91 return static_cast<uint64_t>(t.tv_sec * NS_PER_SEC + t.tv_nsec); 92 } 93 94 std::string DumpFrames(Backtrace* backtrace) { 95 if (backtrace->NumFrames() == 0) { 96 return " No frames to dump.\n"; 97 } 98 99 std::string frame; 100 for (size_t i = 0; i < backtrace->NumFrames(); i++) { 101 frame += " " + backtrace->FormatFrameData(i) + '\n'; 102 } 103 return frame; 104 } 105 106 void WaitForStop(pid_t pid) { 107 uint64_t start = NanoTime(); 108 109 siginfo_t si; 110 while (ptrace(PTRACE_GETSIGINFO, pid, 0, &si) < 0 && (errno == EINTR || errno == ESRCH)) { 111 if ((NanoTime() - start) > NS_PER_SEC) { 112 printf("The process did not get to a stopping point in 1 second.\n"); 113 break; 114 } 115 usleep(US_PER_MSEC); 116 } 117 } 118 119 bool ReadyLevelBacktrace(Backtrace* backtrace) { 120 // See if test_level_four is in the backtrace. 121 bool found = false; 122 for (Backtrace::const_iterator it = backtrace->begin(); it != backtrace->end(); ++it) { 123 if (it->func_name == "test_level_four") { 124 found = true; 125 break; 126 } 127 } 128 129 return found; 130 } 131 132 void VerifyLevelDump(Backtrace* backtrace) { 133 ASSERT_GT(backtrace->NumFrames(), static_cast<size_t>(0)) 134 << DumpFrames(backtrace); 135 ASSERT_LT(backtrace->NumFrames(), static_cast<size_t>(MAX_BACKTRACE_FRAMES)) 136 << DumpFrames(backtrace); 137 138 // Look through the frames starting at the highest to find the 139 // frame we want. 140 size_t frame_num = 0; 141 for (size_t i = backtrace->NumFrames()-1; i > 2; i--) { 142 if (backtrace->GetFrame(i)->func_name == "test_level_one") { 143 frame_num = i; 144 break; 145 } 146 } 147 ASSERT_LT(static_cast<size_t>(0), frame_num) << DumpFrames(backtrace); 148 ASSERT_LE(static_cast<size_t>(3), frame_num) << DumpFrames(backtrace); 149 150 ASSERT_EQ(backtrace->GetFrame(frame_num)->func_name, "test_level_one") 151 << DumpFrames(backtrace); 152 ASSERT_EQ(backtrace->GetFrame(frame_num-1)->func_name, "test_level_two") 153 << DumpFrames(backtrace); 154 ASSERT_EQ(backtrace->GetFrame(frame_num-2)->func_name, "test_level_three") 155 << DumpFrames(backtrace); 156 ASSERT_EQ(backtrace->GetFrame(frame_num-3)->func_name, "test_level_four") 157 << DumpFrames(backtrace); 158 } 159 160 void VerifyLevelBacktrace(void*) { 161 std::unique_ptr<Backtrace> backtrace( 162 Backtrace::Create(BACKTRACE_CURRENT_PROCESS, BACKTRACE_CURRENT_THREAD)); 163 ASSERT_TRUE(backtrace.get() != nullptr); 164 ASSERT_TRUE(backtrace->Unwind(0)); 165 ASSERT_EQ(BACKTRACE_UNWIND_NO_ERROR, backtrace->GetError()); 166 167 VerifyLevelDump(backtrace.get()); 168 } 169 170 bool ReadyMaxBacktrace(Backtrace* backtrace) { 171 return (backtrace->NumFrames() == MAX_BACKTRACE_FRAMES); 172 } 173 174 void VerifyMaxDump(Backtrace* backtrace) { 175 ASSERT_EQ(backtrace->NumFrames(), static_cast<size_t>(MAX_BACKTRACE_FRAMES)) 176 << DumpFrames(backtrace); 177 // Verify that the last frame is our recursive call. 178 ASSERT_EQ(backtrace->GetFrame(MAX_BACKTRACE_FRAMES-1)->func_name, "test_recursive_call") 179 << DumpFrames(backtrace); 180 } 181 182 void VerifyMaxBacktrace(void*) { 183 std::unique_ptr<Backtrace> backtrace( 184 Backtrace::Create(BACKTRACE_CURRENT_PROCESS, BACKTRACE_CURRENT_THREAD)); 185 ASSERT_TRUE(backtrace.get() != nullptr); 186 ASSERT_TRUE(backtrace->Unwind(0)); 187 ASSERT_EQ(BACKTRACE_UNWIND_NO_ERROR, backtrace->GetError()); 188 189 VerifyMaxDump(backtrace.get()); 190 } 191 192 void ThreadSetState(void* data) { 193 thread_t* thread = reinterpret_cast<thread_t*>(data); 194 android_atomic_acquire_store(1, &thread->state); 195 volatile int i = 0; 196 while (thread->state) { 197 i++; 198 } 199 } 200 201 void VerifyThreadTest(pid_t tid, void (*VerifyFunc)(Backtrace*)) { 202 std::unique_ptr<Backtrace> backtrace(Backtrace::Create(getpid(), tid)); 203 ASSERT_TRUE(backtrace.get() != nullptr); 204 ASSERT_TRUE(backtrace->Unwind(0)); 205 ASSERT_EQ(BACKTRACE_UNWIND_NO_ERROR, backtrace->GetError()); 206 207 VerifyFunc(backtrace.get()); 208 } 209 210 bool WaitForNonZero(int32_t* value, uint64_t seconds) { 211 uint64_t start = NanoTime(); 212 do { 213 if (android_atomic_acquire_load(value)) { 214 return true; 215 } 216 } while ((NanoTime() - start) < seconds * NS_PER_SEC); 217 return false; 218 } 219 220 TEST(libbacktrace, local_no_unwind_frames) { 221 // Verify that a local unwind does not include any frames within 222 // libunwind or libbacktrace. 223 std::unique_ptr<Backtrace> backtrace(Backtrace::Create(getpid(), getpid())); 224 ASSERT_TRUE(backtrace.get() != nullptr); 225 ASSERT_TRUE(backtrace->Unwind(0)); 226 ASSERT_EQ(BACKTRACE_UNWIND_NO_ERROR, backtrace->GetError()); 227 228 ASSERT_TRUE(backtrace->NumFrames() != 0); 229 for (const auto& frame : *backtrace ) { 230 if (BacktraceMap::IsValid(frame.map)) { 231 const std::string name = basename(frame.map.name.c_str()); 232 ASSERT_TRUE(name != "libunwind.so" && name != "libbacktrace.so") 233 << DumpFrames(backtrace.get()); 234 } 235 break; 236 } 237 } 238 239 TEST(libbacktrace, local_trace) { 240 ASSERT_NE(test_level_one(1, 2, 3, 4, VerifyLevelBacktrace, nullptr), 0); 241 } 242 243 void VerifyIgnoreFrames( 244 Backtrace* bt_all, Backtrace* bt_ign1, 245 Backtrace* bt_ign2, const char* cur_proc) { 246 EXPECT_EQ(bt_all->NumFrames(), bt_ign1->NumFrames() + 1) 247 << "All backtrace:\n" << DumpFrames(bt_all) << "Ignore 1 backtrace:\n" << DumpFrames(bt_ign1); 248 EXPECT_EQ(bt_all->NumFrames(), bt_ign2->NumFrames() + 2) 249 << "All backtrace:\n" << DumpFrames(bt_all) << "Ignore 2 backtrace:\n" << DumpFrames(bt_ign2); 250 251 // Check all of the frames are the same > the current frame. 252 bool check = (cur_proc == nullptr); 253 for (size_t i = 0; i < bt_ign2->NumFrames(); i++) { 254 if (check) { 255 EXPECT_EQ(bt_ign2->GetFrame(i)->pc, bt_ign1->GetFrame(i+1)->pc); 256 EXPECT_EQ(bt_ign2->GetFrame(i)->sp, bt_ign1->GetFrame(i+1)->sp); 257 EXPECT_EQ(bt_ign2->GetFrame(i)->stack_size, bt_ign1->GetFrame(i+1)->stack_size); 258 259 EXPECT_EQ(bt_ign2->GetFrame(i)->pc, bt_all->GetFrame(i+2)->pc); 260 EXPECT_EQ(bt_ign2->GetFrame(i)->sp, bt_all->GetFrame(i+2)->sp); 261 EXPECT_EQ(bt_ign2->GetFrame(i)->stack_size, bt_all->GetFrame(i+2)->stack_size); 262 } 263 if (!check && bt_ign2->GetFrame(i)->func_name == cur_proc) { 264 check = true; 265 } 266 } 267 } 268 269 void VerifyLevelIgnoreFrames(void*) { 270 std::unique_ptr<Backtrace> all( 271 Backtrace::Create(BACKTRACE_CURRENT_PROCESS, BACKTRACE_CURRENT_THREAD)); 272 ASSERT_TRUE(all.get() != nullptr); 273 ASSERT_TRUE(all->Unwind(0)); 274 ASSERT_EQ(BACKTRACE_UNWIND_NO_ERROR, all->GetError()); 275 276 std::unique_ptr<Backtrace> ign1( 277 Backtrace::Create(BACKTRACE_CURRENT_PROCESS, BACKTRACE_CURRENT_THREAD)); 278 ASSERT_TRUE(ign1.get() != nullptr); 279 ASSERT_TRUE(ign1->Unwind(1)); 280 ASSERT_EQ(BACKTRACE_UNWIND_NO_ERROR, ign1->GetError()); 281 282 std::unique_ptr<Backtrace> ign2( 283 Backtrace::Create(BACKTRACE_CURRENT_PROCESS, BACKTRACE_CURRENT_THREAD)); 284 ASSERT_TRUE(ign2.get() != nullptr); 285 ASSERT_TRUE(ign2->Unwind(2)); 286 ASSERT_EQ(BACKTRACE_UNWIND_NO_ERROR, ign2->GetError()); 287 288 VerifyIgnoreFrames(all.get(), ign1.get(), ign2.get(), "VerifyLevelIgnoreFrames"); 289 } 290 291 TEST(libbacktrace, local_trace_ignore_frames) { 292 ASSERT_NE(test_level_one(1, 2, 3, 4, VerifyLevelIgnoreFrames, nullptr), 0); 293 } 294 295 TEST(libbacktrace, local_max_trace) { 296 ASSERT_NE(test_recursive_call(MAX_BACKTRACE_FRAMES+10, VerifyMaxBacktrace, nullptr), 0); 297 } 298 299 void VerifyProcTest(pid_t pid, pid_t tid, bool share_map, 300 bool (*ReadyFunc)(Backtrace*), 301 void (*VerifyFunc)(Backtrace*)) { 302 pid_t ptrace_tid; 303 if (tid < 0) { 304 ptrace_tid = pid; 305 } else { 306 ptrace_tid = tid; 307 } 308 uint64_t start = NanoTime(); 309 bool verified = false; 310 std::string last_dump; 311 do { 312 usleep(US_PER_MSEC); 313 if (ptrace(PTRACE_ATTACH, ptrace_tid, 0, 0) == 0) { 314 // Wait for the process to get to a stopping point. 315 WaitForStop(ptrace_tid); 316 317 std::unique_ptr<BacktraceMap> map; 318 if (share_map) { 319 map.reset(BacktraceMap::Create(pid)); 320 } 321 std::unique_ptr<Backtrace> backtrace(Backtrace::Create(pid, tid, map.get())); 322 ASSERT_TRUE(backtrace.get() != nullptr); 323 ASSERT_TRUE(backtrace->Unwind(0)); 324 ASSERT_EQ(BACKTRACE_UNWIND_NO_ERROR, backtrace->GetError()); 325 if (ReadyFunc(backtrace.get())) { 326 VerifyFunc(backtrace.get()); 327 verified = true; 328 } else { 329 last_dump = DumpFrames(backtrace.get()); 330 } 331 332 ASSERT_TRUE(ptrace(PTRACE_DETACH, ptrace_tid, 0, 0) == 0); 333 } 334 // If 5 seconds have passed, then we are done. 335 } while (!verified && (NanoTime() - start) <= 5 * NS_PER_SEC); 336 ASSERT_TRUE(verified) << "Last backtrace:\n" << last_dump; 337 } 338 339 TEST(libbacktrace, ptrace_trace) { 340 pid_t pid; 341 if ((pid = fork()) == 0) { 342 ASSERT_NE(test_level_one(1, 2, 3, 4, nullptr, nullptr), 0); 343 _exit(1); 344 } 345 VerifyProcTest(pid, BACKTRACE_CURRENT_THREAD, false, ReadyLevelBacktrace, VerifyLevelDump); 346 347 kill(pid, SIGKILL); 348 int status; 349 ASSERT_EQ(waitpid(pid, &status, 0), pid); 350 } 351 352 TEST(libbacktrace, ptrace_trace_shared_map) { 353 pid_t pid; 354 if ((pid = fork()) == 0) { 355 ASSERT_NE(test_level_one(1, 2, 3, 4, nullptr, nullptr), 0); 356 _exit(1); 357 } 358 359 VerifyProcTest(pid, BACKTRACE_CURRENT_THREAD, true, ReadyLevelBacktrace, VerifyLevelDump); 360 361 kill(pid, SIGKILL); 362 int status; 363 ASSERT_EQ(waitpid(pid, &status, 0), pid); 364 } 365 366 TEST(libbacktrace, ptrace_max_trace) { 367 pid_t pid; 368 if ((pid = fork()) == 0) { 369 ASSERT_NE(test_recursive_call(MAX_BACKTRACE_FRAMES+10, nullptr, nullptr), 0); 370 _exit(1); 371 } 372 VerifyProcTest(pid, BACKTRACE_CURRENT_THREAD, false, ReadyMaxBacktrace, VerifyMaxDump); 373 374 kill(pid, SIGKILL); 375 int status; 376 ASSERT_EQ(waitpid(pid, &status, 0), pid); 377 } 378 379 void VerifyProcessIgnoreFrames(Backtrace* bt_all) { 380 std::unique_ptr<Backtrace> ign1(Backtrace::Create(bt_all->Pid(), BACKTRACE_CURRENT_THREAD)); 381 ASSERT_TRUE(ign1.get() != nullptr); 382 ASSERT_TRUE(ign1->Unwind(1)); 383 ASSERT_EQ(BACKTRACE_UNWIND_NO_ERROR, ign1->GetError()); 384 385 std::unique_ptr<Backtrace> ign2(Backtrace::Create(bt_all->Pid(), BACKTRACE_CURRENT_THREAD)); 386 ASSERT_TRUE(ign2.get() != nullptr); 387 ASSERT_TRUE(ign2->Unwind(2)); 388 ASSERT_EQ(BACKTRACE_UNWIND_NO_ERROR, ign2->GetError()); 389 390 VerifyIgnoreFrames(bt_all, ign1.get(), ign2.get(), nullptr); 391 } 392 393 TEST(libbacktrace, ptrace_ignore_frames) { 394 pid_t pid; 395 if ((pid = fork()) == 0) { 396 ASSERT_NE(test_level_one(1, 2, 3, 4, nullptr, nullptr), 0); 397 _exit(1); 398 } 399 VerifyProcTest(pid, BACKTRACE_CURRENT_THREAD, false, ReadyLevelBacktrace, VerifyProcessIgnoreFrames); 400 401 kill(pid, SIGKILL); 402 int status; 403 ASSERT_EQ(waitpid(pid, &status, 0), pid); 404 } 405 406 // Create a process with multiple threads and dump all of the threads. 407 void* PtraceThreadLevelRun(void*) { 408 EXPECT_NE(test_level_one(1, 2, 3, 4, nullptr, nullptr), 0); 409 return nullptr; 410 } 411 412 void GetThreads(pid_t pid, std::vector<pid_t>* threads) { 413 // Get the list of tasks. 414 char task_path[128]; 415 snprintf(task_path, sizeof(task_path), "/proc/%d/task", pid); 416 417 DIR* tasks_dir = opendir(task_path); 418 ASSERT_TRUE(tasks_dir != nullptr); 419 struct dirent* entry; 420 while ((entry = readdir(tasks_dir)) != nullptr) { 421 char* end; 422 pid_t tid = strtoul(entry->d_name, &end, 10); 423 if (*end == '\0') { 424 threads->push_back(tid); 425 } 426 } 427 closedir(tasks_dir); 428 } 429 430 TEST(libbacktrace, ptrace_threads) { 431 pid_t pid; 432 if ((pid = fork()) == 0) { 433 for (size_t i = 0; i < NUM_PTRACE_THREADS; i++) { 434 pthread_attr_t attr; 435 pthread_attr_init(&attr); 436 pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED); 437 438 pthread_t thread; 439 ASSERT_TRUE(pthread_create(&thread, &attr, PtraceThreadLevelRun, nullptr) == 0); 440 } 441 ASSERT_NE(test_level_one(1, 2, 3, 4, nullptr, nullptr), 0); 442 _exit(1); 443 } 444 445 // Check to see that all of the threads are running before unwinding. 446 std::vector<pid_t> threads; 447 uint64_t start = NanoTime(); 448 do { 449 usleep(US_PER_MSEC); 450 threads.clear(); 451 GetThreads(pid, &threads); 452 } while ((threads.size() != NUM_PTRACE_THREADS + 1) && 453 ((NanoTime() - start) <= 5 * NS_PER_SEC)); 454 ASSERT_EQ(threads.size(), static_cast<size_t>(NUM_PTRACE_THREADS + 1)); 455 456 ASSERT_TRUE(ptrace(PTRACE_ATTACH, pid, 0, 0) == 0); 457 WaitForStop(pid); 458 for (std::vector<int>::const_iterator it = threads.begin(); it != threads.end(); ++it) { 459 // Skip the current forked process, we only care about the threads. 460 if (pid == *it) { 461 continue; 462 } 463 VerifyProcTest(pid, *it, false, ReadyLevelBacktrace, VerifyLevelDump); 464 } 465 ASSERT_TRUE(ptrace(PTRACE_DETACH, pid, 0, 0) == 0); 466 467 kill(pid, SIGKILL); 468 int status; 469 ASSERT_EQ(waitpid(pid, &status, 0), pid); 470 } 471 472 void VerifyLevelThread(void*) { 473 std::unique_ptr<Backtrace> backtrace(Backtrace::Create(getpid(), gettid())); 474 ASSERT_TRUE(backtrace.get() != nullptr); 475 ASSERT_TRUE(backtrace->Unwind(0)); 476 ASSERT_EQ(BACKTRACE_UNWIND_NO_ERROR, backtrace->GetError()); 477 478 VerifyLevelDump(backtrace.get()); 479 } 480 481 TEST(libbacktrace, thread_current_level) { 482 ASSERT_NE(test_level_one(1, 2, 3, 4, VerifyLevelThread, nullptr), 0); 483 } 484 485 void VerifyMaxThread(void*) { 486 std::unique_ptr<Backtrace> backtrace(Backtrace::Create(getpid(), gettid())); 487 ASSERT_TRUE(backtrace.get() != nullptr); 488 ASSERT_TRUE(backtrace->Unwind(0)); 489 ASSERT_EQ(BACKTRACE_UNWIND_NO_ERROR, backtrace->GetError()); 490 491 VerifyMaxDump(backtrace.get()); 492 } 493 494 TEST(libbacktrace, thread_current_max) { 495 ASSERT_NE(test_recursive_call(MAX_BACKTRACE_FRAMES+10, VerifyMaxThread, nullptr), 0); 496 } 497 498 void* ThreadLevelRun(void* data) { 499 thread_t* thread = reinterpret_cast<thread_t*>(data); 500 501 thread->tid = gettid(); 502 EXPECT_NE(test_level_one(1, 2, 3, 4, ThreadSetState, data), 0); 503 return nullptr; 504 } 505 506 TEST(libbacktrace, thread_level_trace) { 507 pthread_attr_t attr; 508 pthread_attr_init(&attr); 509 pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED); 510 511 thread_t thread_data = { 0, 0, 0, nullptr }; 512 pthread_t thread; 513 ASSERT_TRUE(pthread_create(&thread, &attr, ThreadLevelRun, &thread_data) == 0); 514 515 // Wait up to 2 seconds for the tid to be set. 516 ASSERT_TRUE(WaitForNonZero(&thread_data.state, 2)); 517 518 // Make sure that the thread signal used is not visible when compiled for 519 // the target. 520 #if !defined(__GLIBC__) 521 ASSERT_LT(THREAD_SIGNAL, SIGRTMIN); 522 #endif 523 524 // Save the current signal action and make sure it is restored afterwards. 525 struct sigaction cur_action; 526 ASSERT_TRUE(sigaction(THREAD_SIGNAL, nullptr, &cur_action) == 0); 527 528 std::unique_ptr<Backtrace> backtrace(Backtrace::Create(getpid(), thread_data.tid)); 529 ASSERT_TRUE(backtrace.get() != nullptr); 530 ASSERT_TRUE(backtrace->Unwind(0)); 531 ASSERT_EQ(BACKTRACE_UNWIND_NO_ERROR, backtrace->GetError()); 532 533 VerifyLevelDump(backtrace.get()); 534 535 // Tell the thread to exit its infinite loop. 536 android_atomic_acquire_store(0, &thread_data.state); 537 538 // Verify that the old action was restored. 539 struct sigaction new_action; 540 ASSERT_TRUE(sigaction(THREAD_SIGNAL, nullptr, &new_action) == 0); 541 EXPECT_EQ(cur_action.sa_sigaction, new_action.sa_sigaction); 542 // The SA_RESTORER flag gets set behind our back, so a direct comparison 543 // doesn't work unless we mask the value off. Mips doesn't have this 544 // flag, so skip this on that platform. 545 #if defined(SA_RESTORER) 546 cur_action.sa_flags &= ~SA_RESTORER; 547 new_action.sa_flags &= ~SA_RESTORER; 548 #elif defined(__GLIBC__) 549 // Our host compiler doesn't appear to define this flag for some reason. 550 cur_action.sa_flags &= ~0x04000000; 551 new_action.sa_flags &= ~0x04000000; 552 #endif 553 EXPECT_EQ(cur_action.sa_flags, new_action.sa_flags); 554 } 555 556 TEST(libbacktrace, thread_ignore_frames) { 557 pthread_attr_t attr; 558 pthread_attr_init(&attr); 559 pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED); 560 561 thread_t thread_data = { 0, 0, 0, nullptr }; 562 pthread_t thread; 563 ASSERT_TRUE(pthread_create(&thread, &attr, ThreadLevelRun, &thread_data) == 0); 564 565 // Wait up to 2 seconds for the tid to be set. 566 ASSERT_TRUE(WaitForNonZero(&thread_data.state, 2)); 567 568 std::unique_ptr<Backtrace> all(Backtrace::Create(getpid(), thread_data.tid)); 569 ASSERT_TRUE(all.get() != nullptr); 570 ASSERT_TRUE(all->Unwind(0)); 571 ASSERT_EQ(BACKTRACE_UNWIND_NO_ERROR, all->GetError()); 572 573 std::unique_ptr<Backtrace> ign1(Backtrace::Create(getpid(), thread_data.tid)); 574 ASSERT_TRUE(ign1.get() != nullptr); 575 ASSERT_TRUE(ign1->Unwind(1)); 576 ASSERT_EQ(BACKTRACE_UNWIND_NO_ERROR, ign1->GetError()); 577 578 std::unique_ptr<Backtrace> ign2(Backtrace::Create(getpid(), thread_data.tid)); 579 ASSERT_TRUE(ign2.get() != nullptr); 580 ASSERT_TRUE(ign2->Unwind(2)); 581 ASSERT_EQ(BACKTRACE_UNWIND_NO_ERROR, ign2->GetError()); 582 583 VerifyIgnoreFrames(all.get(), ign1.get(), ign2.get(), nullptr); 584 585 // Tell the thread to exit its infinite loop. 586 android_atomic_acquire_store(0, &thread_data.state); 587 } 588 589 void* ThreadMaxRun(void* data) { 590 thread_t* thread = reinterpret_cast<thread_t*>(data); 591 592 thread->tid = gettid(); 593 EXPECT_NE(test_recursive_call(MAX_BACKTRACE_FRAMES+10, ThreadSetState, data), 0); 594 return nullptr; 595 } 596 597 TEST(libbacktrace, thread_max_trace) { 598 pthread_attr_t attr; 599 pthread_attr_init(&attr); 600 pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED); 601 602 thread_t thread_data = { 0, 0, 0, nullptr }; 603 pthread_t thread; 604 ASSERT_TRUE(pthread_create(&thread, &attr, ThreadMaxRun, &thread_data) == 0); 605 606 // Wait for the tid to be set. 607 ASSERT_TRUE(WaitForNonZero(&thread_data.state, 2)); 608 609 std::unique_ptr<Backtrace> backtrace(Backtrace::Create(getpid(), thread_data.tid)); 610 ASSERT_TRUE(backtrace.get() != nullptr); 611 ASSERT_TRUE(backtrace->Unwind(0)); 612 ASSERT_EQ(BACKTRACE_UNWIND_NO_ERROR, backtrace->GetError()); 613 614 VerifyMaxDump(backtrace.get()); 615 616 // Tell the thread to exit its infinite loop. 617 android_atomic_acquire_store(0, &thread_data.state); 618 } 619 620 void* ThreadDump(void* data) { 621 dump_thread_t* dump = reinterpret_cast<dump_thread_t*>(data); 622 while (true) { 623 if (android_atomic_acquire_load(dump->now)) { 624 break; 625 } 626 } 627 628 // The status of the actual unwind will be checked elsewhere. 629 dump->backtrace = Backtrace::Create(getpid(), dump->thread.tid); 630 dump->backtrace->Unwind(0); 631 632 android_atomic_acquire_store(1, &dump->done); 633 634 return nullptr; 635 } 636 637 TEST(libbacktrace, thread_multiple_dump) { 638 // Dump NUM_THREADS simultaneously. 639 std::vector<thread_t> runners(NUM_THREADS); 640 std::vector<dump_thread_t> dumpers(NUM_THREADS); 641 642 pthread_attr_t attr; 643 pthread_attr_init(&attr); 644 pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED); 645 for (size_t i = 0; i < NUM_THREADS; i++) { 646 // Launch the runners, they will spin in hard loops doing nothing. 647 runners[i].tid = 0; 648 runners[i].state = 0; 649 ASSERT_TRUE(pthread_create(&runners[i].threadId, &attr, ThreadMaxRun, &runners[i]) == 0); 650 } 651 652 // Wait for tids to be set. 653 for (std::vector<thread_t>::iterator it = runners.begin(); it != runners.end(); ++it) { 654 ASSERT_TRUE(WaitForNonZero(&it->state, 30)); 655 } 656 657 // Start all of the dumpers at once, they will spin until they are signalled 658 // to begin their dump run. 659 int32_t dump_now = 0; 660 for (size_t i = 0; i < NUM_THREADS; i++) { 661 dumpers[i].thread.tid = runners[i].tid; 662 dumpers[i].thread.state = 0; 663 dumpers[i].done = 0; 664 dumpers[i].now = &dump_now; 665 666 ASSERT_TRUE(pthread_create(&dumpers[i].thread.threadId, &attr, ThreadDump, &dumpers[i]) == 0); 667 } 668 669 // Start all of the dumpers going at once. 670 android_atomic_acquire_store(1, &dump_now); 671 672 for (size_t i = 0; i < NUM_THREADS; i++) { 673 ASSERT_TRUE(WaitForNonZero(&dumpers[i].done, 30)); 674 675 // Tell the runner thread to exit its infinite loop. 676 android_atomic_acquire_store(0, &runners[i].state); 677 678 ASSERT_TRUE(dumpers[i].backtrace != nullptr); 679 VerifyMaxDump(dumpers[i].backtrace); 680 681 delete dumpers[i].backtrace; 682 dumpers[i].backtrace = nullptr; 683 } 684 } 685 686 TEST(libbacktrace, thread_multiple_dump_same_thread) { 687 pthread_attr_t attr; 688 pthread_attr_init(&attr); 689 pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED); 690 thread_t runner; 691 runner.tid = 0; 692 runner.state = 0; 693 ASSERT_TRUE(pthread_create(&runner.threadId, &attr, ThreadMaxRun, &runner) == 0); 694 695 // Wait for tids to be set. 696 ASSERT_TRUE(WaitForNonZero(&runner.state, 30)); 697 698 // Start all of the dumpers at once, they will spin until they are signalled 699 // to begin their dump run. 700 int32_t dump_now = 0; 701 // Dump the same thread NUM_THREADS simultaneously. 702 std::vector<dump_thread_t> dumpers(NUM_THREADS); 703 for (size_t i = 0; i < NUM_THREADS; i++) { 704 dumpers[i].thread.tid = runner.tid; 705 dumpers[i].thread.state = 0; 706 dumpers[i].done = 0; 707 dumpers[i].now = &dump_now; 708 709 ASSERT_TRUE(pthread_create(&dumpers[i].thread.threadId, &attr, ThreadDump, &dumpers[i]) == 0); 710 } 711 712 // Start all of the dumpers going at once. 713 android_atomic_acquire_store(1, &dump_now); 714 715 for (size_t i = 0; i < NUM_THREADS; i++) { 716 ASSERT_TRUE(WaitForNonZero(&dumpers[i].done, 30)); 717 718 ASSERT_TRUE(dumpers[i].backtrace != nullptr); 719 VerifyMaxDump(dumpers[i].backtrace); 720 721 delete dumpers[i].backtrace; 722 dumpers[i].backtrace = nullptr; 723 } 724 725 // Tell the runner thread to exit its infinite loop. 726 android_atomic_acquire_store(0, &runner.state); 727 } 728 729 // This test is for UnwindMaps that should share the same map cursor when 730 // multiple maps are created for the current process at the same time. 731 TEST(libbacktrace, simultaneous_maps) { 732 BacktraceMap* map1 = BacktraceMap::Create(getpid()); 733 BacktraceMap* map2 = BacktraceMap::Create(getpid()); 734 BacktraceMap* map3 = BacktraceMap::Create(getpid()); 735 736 Backtrace* back1 = Backtrace::Create(getpid(), BACKTRACE_CURRENT_THREAD, map1); 737 ASSERT_TRUE(back1 != nullptr); 738 EXPECT_TRUE(back1->Unwind(0)); 739 ASSERT_EQ(BACKTRACE_UNWIND_NO_ERROR, back1->GetError()); 740 delete back1; 741 delete map1; 742 743 Backtrace* back2 = Backtrace::Create(getpid(), BACKTRACE_CURRENT_THREAD, map2); 744 ASSERT_TRUE(back2 != nullptr); 745 EXPECT_TRUE(back2->Unwind(0)); 746 ASSERT_EQ(BACKTRACE_UNWIND_NO_ERROR, back2->GetError()); 747 delete back2; 748 delete map2; 749 750 Backtrace* back3 = Backtrace::Create(getpid(), BACKTRACE_CURRENT_THREAD, map3); 751 ASSERT_TRUE(back3 != nullptr); 752 EXPECT_TRUE(back3->Unwind(0)); 753 ASSERT_EQ(BACKTRACE_UNWIND_NO_ERROR, back3->GetError()); 754 delete back3; 755 delete map3; 756 } 757 758 TEST(libbacktrace, fillin_erases) { 759 BacktraceMap* back_map = BacktraceMap::Create(getpid()); 760 761 backtrace_map_t map; 762 763 map.start = 1; 764 map.end = 3; 765 map.flags = 1; 766 map.name = "Initialized"; 767 back_map->FillIn(0, &map); 768 delete back_map; 769 770 ASSERT_FALSE(BacktraceMap::IsValid(map)); 771 ASSERT_EQ(static_cast<uintptr_t>(0), map.start); 772 ASSERT_EQ(static_cast<uintptr_t>(0), map.end); 773 ASSERT_EQ(0, map.flags); 774 ASSERT_EQ("", map.name); 775 } 776 777 TEST(libbacktrace, format_test) { 778 std::unique_ptr<Backtrace> backtrace(Backtrace::Create(getpid(), BACKTRACE_CURRENT_THREAD)); 779 ASSERT_TRUE(backtrace.get() != nullptr); 780 781 backtrace_frame_data_t frame; 782 frame.num = 1; 783 frame.pc = 2; 784 frame.sp = 0; 785 frame.stack_size = 0; 786 frame.func_offset = 0; 787 788 // Check no map set. 789 frame.num = 1; 790 #if defined(__LP64__) 791 EXPECT_EQ("#01 pc 0000000000000002 <unknown>", 792 #else 793 EXPECT_EQ("#01 pc 00000002 <unknown>", 794 #endif 795 backtrace->FormatFrameData(&frame)); 796 797 // Check map name empty, but exists. 798 frame.pc = 0xb0020; 799 frame.map.start = 0xb0000; 800 frame.map.end = 0xbffff; 801 frame.map.load_base = 0; 802 #if defined(__LP64__) 803 EXPECT_EQ("#01 pc 0000000000000020 <anonymous:00000000000b0000>", 804 #else 805 EXPECT_EQ("#01 pc 00000020 <anonymous:000b0000>", 806 #endif 807 backtrace->FormatFrameData(&frame)); 808 809 // Check map name begins with a [. 810 frame.pc = 0xc0020; 811 frame.map.start = 0xc0000; 812 frame.map.end = 0xcffff; 813 frame.map.load_base = 0; 814 frame.map.name = "[anon:thread signal stack]"; 815 #if defined(__LP64__) 816 EXPECT_EQ("#01 pc 0000000000000020 [anon:thread signal stack:00000000000c0000]", 817 #else 818 EXPECT_EQ("#01 pc 00000020 [anon:thread signal stack:000c0000]", 819 #endif 820 backtrace->FormatFrameData(&frame)); 821 822 // Check relative pc is set and map name is set. 823 frame.pc = 0x12345679; 824 frame.map.name = "MapFake"; 825 frame.map.start = 1; 826 frame.map.end = 1; 827 #if defined(__LP64__) 828 EXPECT_EQ("#01 pc 0000000012345678 MapFake", 829 #else 830 EXPECT_EQ("#01 pc 12345678 MapFake", 831 #endif 832 backtrace->FormatFrameData(&frame)); 833 834 // Check func_name is set, but no func offset. 835 frame.func_name = "ProcFake"; 836 #if defined(__LP64__) 837 EXPECT_EQ("#01 pc 0000000012345678 MapFake (ProcFake)", 838 #else 839 EXPECT_EQ("#01 pc 12345678 MapFake (ProcFake)", 840 #endif 841 backtrace->FormatFrameData(&frame)); 842 843 // Check func_name is set, and func offset is non-zero. 844 frame.func_offset = 645; 845 #if defined(__LP64__) 846 EXPECT_EQ("#01 pc 0000000012345678 MapFake (ProcFake+645)", 847 #else 848 EXPECT_EQ("#01 pc 12345678 MapFake (ProcFake+645)", 849 #endif 850 backtrace->FormatFrameData(&frame)); 851 852 // Check func_name is set, func offset is non-zero, and load_base is non-zero. 853 frame.func_offset = 645; 854 frame.map.load_base = 100; 855 #if defined(__LP64__) 856 EXPECT_EQ("#01 pc 00000000123456dc MapFake (ProcFake+645)", 857 #else 858 EXPECT_EQ("#01 pc 123456dc MapFake (ProcFake+645)", 859 #endif 860 backtrace->FormatFrameData(&frame)); 861 862 // Check a non-zero map offset. 863 frame.map.offset = 0x1000; 864 #if defined(__LP64__) 865 EXPECT_EQ("#01 pc 00000000123456dc MapFake (offset 0x1000) (ProcFake+645)", 866 #else 867 EXPECT_EQ("#01 pc 123456dc MapFake (offset 0x1000) (ProcFake+645)", 868 #endif 869 backtrace->FormatFrameData(&frame)); 870 } 871 872 struct map_test_t { 873 uintptr_t start; 874 uintptr_t end; 875 }; 876 877 bool map_sort(map_test_t i, map_test_t j) { 878 return i.start < j.start; 879 } 880 881 void VerifyMap(pid_t pid) { 882 char buffer[4096]; 883 snprintf(buffer, sizeof(buffer), "/proc/%d/maps", pid); 884 885 FILE* map_file = fopen(buffer, "r"); 886 ASSERT_TRUE(map_file != nullptr); 887 std::vector<map_test_t> test_maps; 888 while (fgets(buffer, sizeof(buffer), map_file)) { 889 map_test_t map; 890 ASSERT_EQ(2, sscanf(buffer, "%" SCNxPTR "-%" SCNxPTR " ", &map.start, &map.end)); 891 test_maps.push_back(map); 892 } 893 fclose(map_file); 894 std::sort(test_maps.begin(), test_maps.end(), map_sort); 895 896 std::unique_ptr<BacktraceMap> map(BacktraceMap::Create(pid)); 897 898 // Basic test that verifies that the map is in the expected order. 899 std::vector<map_test_t>::const_iterator test_it = test_maps.begin(); 900 for (BacktraceMap::const_iterator it = map->begin(); it != map->end(); ++it) { 901 ASSERT_TRUE(test_it != test_maps.end()); 902 ASSERT_EQ(test_it->start, it->start); 903 ASSERT_EQ(test_it->end, it->end); 904 ++test_it; 905 } 906 ASSERT_TRUE(test_it == test_maps.end()); 907 } 908 909 TEST(libbacktrace, verify_map_remote) { 910 pid_t pid; 911 912 if ((pid = fork()) == 0) { 913 while (true) { 914 } 915 _exit(0); 916 } 917 ASSERT_LT(0, pid); 918 919 ASSERT_TRUE(ptrace(PTRACE_ATTACH, pid, 0, 0) == 0); 920 921 // Wait for the process to get to a stopping point. 922 WaitForStop(pid); 923 924 // The maps should match exactly since the forked process has been paused. 925 VerifyMap(pid); 926 927 ASSERT_TRUE(ptrace(PTRACE_DETACH, pid, 0, 0) == 0); 928 929 kill(pid, SIGKILL); 930 ASSERT_EQ(waitpid(pid, nullptr, 0), pid); 931 } 932 933 void InitMemory(uint8_t* memory, size_t bytes) { 934 for (size_t i = 0; i < bytes; i++) { 935 memory[i] = i; 936 if (memory[i] == '\0') { 937 // Don't use '\0' in our data so we can verify that an overread doesn't 938 // occur by using a '\0' as the character after the read data. 939 memory[i] = 23; 940 } 941 } 942 } 943 944 void* ThreadReadTest(void* data) { 945 thread_t* thread_data = reinterpret_cast<thread_t*>(data); 946 947 thread_data->tid = gettid(); 948 949 // Create two map pages. 950 // Mark the second page as not-readable. 951 size_t pagesize = static_cast<size_t>(sysconf(_SC_PAGE_SIZE)); 952 uint8_t* memory; 953 if (posix_memalign(reinterpret_cast<void**>(&memory), pagesize, 2 * pagesize) != 0) { 954 return reinterpret_cast<void*>(-1); 955 } 956 957 if (mprotect(&memory[pagesize], pagesize, PROT_NONE) != 0) { 958 return reinterpret_cast<void*>(-1); 959 } 960 961 // Set up a simple pattern in memory. 962 InitMemory(memory, pagesize); 963 964 thread_data->data = memory; 965 966 // Tell the caller it's okay to start reading memory. 967 android_atomic_acquire_store(1, &thread_data->state); 968 969 // Loop waiting for the caller to finish reading the memory. 970 while (thread_data->state) { 971 } 972 973 // Re-enable read-write on the page so that we don't crash if we try 974 // and access data on this page when freeing the memory. 975 if (mprotect(&memory[pagesize], pagesize, PROT_READ | PROT_WRITE) != 0) { 976 return reinterpret_cast<void*>(-1); 977 } 978 free(memory); 979 980 android_atomic_acquire_store(1, &thread_data->state); 981 982 return nullptr; 983 } 984 985 void RunReadTest(Backtrace* backtrace, uintptr_t read_addr) { 986 size_t pagesize = static_cast<size_t>(sysconf(_SC_PAGE_SIZE)); 987 988 // Create a page of data to use to do quick compares. 989 uint8_t* expected = new uint8_t[pagesize]; 990 InitMemory(expected, pagesize); 991 992 uint8_t* data = new uint8_t[2*pagesize]; 993 // Verify that we can only read one page worth of data. 994 size_t bytes_read = backtrace->Read(read_addr, data, 2 * pagesize); 995 ASSERT_EQ(pagesize, bytes_read); 996 ASSERT_TRUE(memcmp(data, expected, pagesize) == 0); 997 998 // Verify unaligned reads. 999 for (size_t i = 1; i < sizeof(word_t); i++) { 1000 bytes_read = backtrace->Read(read_addr + i, data, 2 * sizeof(word_t)); 1001 ASSERT_EQ(2 * sizeof(word_t), bytes_read); 1002 ASSERT_TRUE(memcmp(data, &expected[i], 2 * sizeof(word_t)) == 0) 1003 << "Offset at " << i << " failed"; 1004 } 1005 1006 // Verify small unaligned reads. 1007 for (size_t i = 1; i < sizeof(word_t); i++) { 1008 for (size_t j = 1; j < sizeof(word_t); j++) { 1009 // Set one byte past what we expect to read, to guarantee we don't overread. 1010 data[j] = '\0'; 1011 bytes_read = backtrace->Read(read_addr + i, data, j); 1012 ASSERT_EQ(j, bytes_read); 1013 ASSERT_TRUE(memcmp(data, &expected[i], j) == 0) 1014 << "Offset at " << i << " length " << j << " miscompared"; 1015 ASSERT_EQ('\0', data[j]) 1016 << "Offset at " << i << " length " << j << " wrote too much data"; 1017 } 1018 } 1019 delete[] data; 1020 delete[] expected; 1021 } 1022 1023 TEST(libbacktrace, thread_read) { 1024 pthread_attr_t attr; 1025 pthread_attr_init(&attr); 1026 pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED); 1027 pthread_t thread; 1028 thread_t thread_data = { 0, 0, 0, nullptr }; 1029 ASSERT_TRUE(pthread_create(&thread, &attr, ThreadReadTest, &thread_data) == 0); 1030 1031 ASSERT_TRUE(WaitForNonZero(&thread_data.state, 10)); 1032 1033 std::unique_ptr<Backtrace> backtrace(Backtrace::Create(getpid(), thread_data.tid)); 1034 ASSERT_TRUE(backtrace.get() != nullptr); 1035 1036 RunReadTest(backtrace.get(), reinterpret_cast<uintptr_t>(thread_data.data)); 1037 1038 android_atomic_acquire_store(0, &thread_data.state); 1039 1040 ASSERT_TRUE(WaitForNonZero(&thread_data.state, 10)); 1041 } 1042 1043 volatile uintptr_t g_ready = 0; 1044 volatile uintptr_t g_addr = 0; 1045 1046 void ForkedReadTest() { 1047 // Create two map pages. 1048 size_t pagesize = static_cast<size_t>(sysconf(_SC_PAGE_SIZE)); 1049 uint8_t* memory; 1050 if (posix_memalign(reinterpret_cast<void**>(&memory), pagesize, 2 * pagesize) != 0) { 1051 perror("Failed to allocate memory\n"); 1052 exit(1); 1053 } 1054 1055 // Mark the second page as not-readable. 1056 if (mprotect(&memory[pagesize], pagesize, PROT_NONE) != 0) { 1057 perror("Failed to mprotect memory\n"); 1058 exit(1); 1059 } 1060 1061 // Set up a simple pattern in memory. 1062 InitMemory(memory, pagesize); 1063 1064 g_addr = reinterpret_cast<uintptr_t>(memory); 1065 g_ready = 1; 1066 1067 while (1) { 1068 usleep(US_PER_MSEC); 1069 } 1070 } 1071 1072 TEST(libbacktrace, process_read) { 1073 g_ready = 0; 1074 pid_t pid; 1075 if ((pid = fork()) == 0) { 1076 ForkedReadTest(); 1077 exit(0); 1078 } 1079 ASSERT_NE(-1, pid); 1080 1081 bool test_executed = false; 1082 uint64_t start = NanoTime(); 1083 while (1) { 1084 if (ptrace(PTRACE_ATTACH, pid, 0, 0) == 0) { 1085 WaitForStop(pid); 1086 1087 std::unique_ptr<Backtrace> backtrace(Backtrace::Create(pid, pid)); 1088 ASSERT_TRUE(backtrace.get() != nullptr); 1089 1090 uintptr_t read_addr; 1091 size_t bytes_read = backtrace->Read(reinterpret_cast<uintptr_t>(&g_ready), 1092 reinterpret_cast<uint8_t*>(&read_addr), 1093 sizeof(uintptr_t)); 1094 ASSERT_EQ(sizeof(uintptr_t), bytes_read); 1095 if (read_addr) { 1096 // The forked process is ready to be read. 1097 bytes_read = backtrace->Read(reinterpret_cast<uintptr_t>(&g_addr), 1098 reinterpret_cast<uint8_t*>(&read_addr), 1099 sizeof(uintptr_t)); 1100 ASSERT_EQ(sizeof(uintptr_t), bytes_read); 1101 1102 RunReadTest(backtrace.get(), read_addr); 1103 1104 test_executed = true; 1105 break; 1106 } 1107 ASSERT_TRUE(ptrace(PTRACE_DETACH, pid, 0, 0) == 0); 1108 } 1109 if ((NanoTime() - start) > 5 * NS_PER_SEC) { 1110 break; 1111 } 1112 usleep(US_PER_MSEC); 1113 } 1114 kill(pid, SIGKILL); 1115 ASSERT_EQ(waitpid(pid, nullptr, 0), pid); 1116 1117 ASSERT_TRUE(test_executed); 1118 } 1119 1120 void VerifyFunctionsFound(const std::vector<std::string>& found_functions) { 1121 // We expect to find these functions in libbacktrace_test. If we don't 1122 // find them, that's a bug in the memory read handling code in libunwind. 1123 std::list<std::string> expected_functions; 1124 expected_functions.push_back("test_recursive_call"); 1125 expected_functions.push_back("test_level_one"); 1126 expected_functions.push_back("test_level_two"); 1127 expected_functions.push_back("test_level_three"); 1128 expected_functions.push_back("test_level_four"); 1129 for (const auto& found_function : found_functions) { 1130 for (const auto& expected_function : expected_functions) { 1131 if (found_function == expected_function) { 1132 expected_functions.remove(found_function); 1133 break; 1134 } 1135 } 1136 } 1137 ASSERT_TRUE(expected_functions.empty()) << "Not all functions found in shared library."; 1138 } 1139 1140 const char* CopySharedLibrary() { 1141 #if defined(__LP64__) 1142 const char* lib_name = "lib64"; 1143 #else 1144 const char* lib_name = "lib"; 1145 #endif 1146 1147 #if defined(__BIONIC__) 1148 const char* tmp_so_name = "/data/local/tmp/libbacktrace_test.so"; 1149 std::string cp_cmd = android::base::StringPrintf("cp /system/%s/libbacktrace_test.so %s", 1150 lib_name, tmp_so_name); 1151 #else 1152 const char* tmp_so_name = "/tmp/libbacktrace_test.so"; 1153 if (getenv("ANDROID_HOST_OUT") == NULL) { 1154 fprintf(stderr, "ANDROID_HOST_OUT not set, make sure you run lunch."); 1155 return nullptr; 1156 } 1157 std::string cp_cmd = android::base::StringPrintf("cp %s/%s/libbacktrace_test.so %s", 1158 getenv("ANDROID_HOST_OUT"), lib_name, 1159 tmp_so_name); 1160 #endif 1161 1162 // Copy the shared so to a tempory directory. 1163 system(cp_cmd.c_str()); 1164 1165 return tmp_so_name; 1166 } 1167 1168 TEST(libbacktrace, check_unreadable_elf_local) { 1169 const char* tmp_so_name = CopySharedLibrary(); 1170 ASSERT_TRUE(tmp_so_name != nullptr); 1171 1172 struct stat buf; 1173 ASSERT_TRUE(stat(tmp_so_name, &buf) != -1); 1174 uintptr_t map_size = buf.st_size; 1175 1176 int fd = open(tmp_so_name, O_RDONLY); 1177 ASSERT_TRUE(fd != -1); 1178 1179 void* map = mmap(NULL, map_size, PROT_READ | PROT_EXEC, MAP_PRIVATE, fd, 0); 1180 ASSERT_TRUE(map != MAP_FAILED); 1181 close(fd); 1182 ASSERT_TRUE(unlink(tmp_so_name) != -1); 1183 1184 std::vector<std::string> found_functions; 1185 std::unique_ptr<Backtrace> backtrace(Backtrace::Create(BACKTRACE_CURRENT_PROCESS, 1186 BACKTRACE_CURRENT_THREAD)); 1187 ASSERT_TRUE(backtrace.get() != nullptr); 1188 1189 // Needed before GetFunctionName will work. 1190 backtrace->Unwind(0); 1191 1192 // Loop through the entire map, and get every function we can find. 1193 map_size += reinterpret_cast<uintptr_t>(map); 1194 std::string last_func; 1195 for (uintptr_t read_addr = reinterpret_cast<uintptr_t>(map); 1196 read_addr < map_size; read_addr += 4) { 1197 uintptr_t offset; 1198 std::string func_name = backtrace->GetFunctionName(read_addr, &offset); 1199 if (!func_name.empty() && last_func != func_name) { 1200 found_functions.push_back(func_name); 1201 } 1202 last_func = func_name; 1203 } 1204 1205 ASSERT_TRUE(munmap(map, map_size - reinterpret_cast<uintptr_t>(map)) == 0); 1206 1207 VerifyFunctionsFound(found_functions); 1208 } 1209 1210 TEST(libbacktrace, check_unreadable_elf_remote) { 1211 const char* tmp_so_name = CopySharedLibrary(); 1212 ASSERT_TRUE(tmp_so_name != nullptr); 1213 1214 g_ready = 0; 1215 1216 struct stat buf; 1217 ASSERT_TRUE(stat(tmp_so_name, &buf) != -1); 1218 uintptr_t map_size = buf.st_size; 1219 1220 pid_t pid; 1221 if ((pid = fork()) == 0) { 1222 int fd = open(tmp_so_name, O_RDONLY); 1223 if (fd == -1) { 1224 fprintf(stderr, "Failed to open file %s: %s\n", tmp_so_name, strerror(errno)); 1225 unlink(tmp_so_name); 1226 exit(0); 1227 } 1228 1229 void* map = mmap(NULL, map_size, PROT_READ | PROT_EXEC, MAP_PRIVATE, fd, 0); 1230 if (map == MAP_FAILED) { 1231 fprintf(stderr, "Failed to map in memory: %s\n", strerror(errno)); 1232 unlink(tmp_so_name); 1233 exit(0); 1234 } 1235 close(fd); 1236 if (unlink(tmp_so_name) == -1) { 1237 fprintf(stderr, "Failed to unlink: %s\n", strerror(errno)); 1238 exit(0); 1239 } 1240 1241 g_addr = reinterpret_cast<uintptr_t>(map); 1242 g_ready = 1; 1243 while (true) { 1244 usleep(US_PER_MSEC); 1245 } 1246 exit(0); 1247 } 1248 ASSERT_TRUE(pid > 0); 1249 1250 std::vector<std::string> found_functions; 1251 uint64_t start = NanoTime(); 1252 while (true) { 1253 ASSERT_TRUE(ptrace(PTRACE_ATTACH, pid, 0, 0) == 0); 1254 1255 // Wait for the process to get to a stopping point. 1256 WaitForStop(pid); 1257 1258 std::unique_ptr<Backtrace> backtrace(Backtrace::Create(pid, BACKTRACE_CURRENT_THREAD)); 1259 ASSERT_TRUE(backtrace.get() != nullptr); 1260 1261 uintptr_t read_addr; 1262 ASSERT_EQ(sizeof(uintptr_t), backtrace->Read(reinterpret_cast<uintptr_t>(&g_ready), reinterpret_cast<uint8_t*>(&read_addr), sizeof(uintptr_t))); 1263 if (read_addr) { 1264 ASSERT_EQ(sizeof(uintptr_t), backtrace->Read(reinterpret_cast<uintptr_t>(&g_addr), reinterpret_cast<uint8_t*>(&read_addr), sizeof(uintptr_t))); 1265 1266 // Needed before GetFunctionName will work. 1267 backtrace->Unwind(0); 1268 1269 // Loop through the entire map, and get every function we can find. 1270 map_size += read_addr; 1271 std::string last_func; 1272 for (; read_addr < map_size; read_addr += 4) { 1273 uintptr_t offset; 1274 std::string func_name = backtrace->GetFunctionName(read_addr, &offset); 1275 if (!func_name.empty() && last_func != func_name) { 1276 found_functions.push_back(func_name); 1277 } 1278 last_func = func_name; 1279 } 1280 break; 1281 } 1282 ASSERT_TRUE(ptrace(PTRACE_DETACH, pid, 0, 0) == 0); 1283 1284 if ((NanoTime() - start) > 5 * NS_PER_SEC) { 1285 break; 1286 } 1287 usleep(US_PER_MSEC); 1288 } 1289 1290 kill(pid, SIGKILL); 1291 ASSERT_EQ(waitpid(pid, nullptr, 0), pid); 1292 1293 VerifyFunctionsFound(found_functions); 1294 } 1295 1296 bool FindFuncFrameInBacktrace(Backtrace* backtrace, uintptr_t test_func, size_t* frame_num) { 1297 backtrace_map_t map; 1298 backtrace->FillInMap(test_func, &map); 1299 if (!BacktraceMap::IsValid(map)) { 1300 return false; 1301 } 1302 1303 // Loop through the frames, and find the one that is in the map. 1304 *frame_num = 0; 1305 for (Backtrace::const_iterator it = backtrace->begin(); it != backtrace->end(); ++it) { 1306 if (BacktraceMap::IsValid(it->map) && map.start == it->map.start && 1307 it->pc >= test_func) { 1308 *frame_num = it->num; 1309 return true; 1310 } 1311 } 1312 return false; 1313 } 1314 1315 void VerifyUnreadableElfFrame(Backtrace* backtrace, uintptr_t test_func, size_t frame_num) { 1316 ASSERT_LT(backtrace->NumFrames(), static_cast<size_t>(MAX_BACKTRACE_FRAMES)) 1317 << DumpFrames(backtrace); 1318 1319 ASSERT_TRUE(frame_num != 0) << DumpFrames(backtrace); 1320 // Make sure that there is at least one more frame above the test func call. 1321 ASSERT_LT(frame_num, backtrace->NumFrames()) << DumpFrames(backtrace); 1322 1323 uintptr_t diff = backtrace->GetFrame(frame_num)->pc - test_func; 1324 ASSERT_LT(diff, 200U) << DumpFrames(backtrace); 1325 } 1326 1327 void VerifyUnreadableElfBacktrace(uintptr_t test_func) { 1328 std::unique_ptr<Backtrace> backtrace(Backtrace::Create(BACKTRACE_CURRENT_PROCESS, 1329 BACKTRACE_CURRENT_THREAD)); 1330 ASSERT_TRUE(backtrace.get() != nullptr); 1331 ASSERT_TRUE(backtrace->Unwind(0)); 1332 ASSERT_EQ(BACKTRACE_UNWIND_NO_ERROR, backtrace->GetError()); 1333 1334 size_t frame_num; 1335 ASSERT_TRUE(FindFuncFrameInBacktrace(backtrace.get(), test_func, &frame_num)); 1336 1337 VerifyUnreadableElfFrame(backtrace.get(), test_func, frame_num); 1338 } 1339 1340 typedef int (*test_func_t)(int, int, int, int, void (*)(uintptr_t), uintptr_t); 1341 1342 TEST(libbacktrace, unwind_through_unreadable_elf_local) { 1343 const char* tmp_so_name = CopySharedLibrary(); 1344 ASSERT_TRUE(tmp_so_name != nullptr); 1345 void* lib_handle = dlopen(tmp_so_name, RTLD_NOW); 1346 ASSERT_TRUE(lib_handle != nullptr); 1347 ASSERT_TRUE(unlink(tmp_so_name) != -1); 1348 1349 test_func_t test_func; 1350 test_func = reinterpret_cast<test_func_t>(dlsym(lib_handle, "test_level_one")); 1351 ASSERT_TRUE(test_func != nullptr); 1352 1353 ASSERT_NE(test_func(1, 2, 3, 4, VerifyUnreadableElfBacktrace, 1354 reinterpret_cast<uintptr_t>(test_func)), 0); 1355 1356 ASSERT_TRUE(dlclose(lib_handle) == 0); 1357 } 1358 1359 TEST(libbacktrace, unwind_through_unreadable_elf_remote) { 1360 const char* tmp_so_name = CopySharedLibrary(); 1361 ASSERT_TRUE(tmp_so_name != nullptr); 1362 void* lib_handle = dlopen(tmp_so_name, RTLD_NOW); 1363 ASSERT_TRUE(lib_handle != nullptr); 1364 ASSERT_TRUE(unlink(tmp_so_name) != -1); 1365 1366 test_func_t test_func; 1367 test_func = reinterpret_cast<test_func_t>(dlsym(lib_handle, "test_level_one")); 1368 ASSERT_TRUE(test_func != nullptr); 1369 1370 pid_t pid; 1371 if ((pid = fork()) == 0) { 1372 test_func(1, 2, 3, 4, 0, 0); 1373 exit(0); 1374 } 1375 ASSERT_TRUE(pid > 0); 1376 ASSERT_TRUE(dlclose(lib_handle) == 0); 1377 1378 uint64_t start = NanoTime(); 1379 bool done = false; 1380 while (!done) { 1381 ASSERT_TRUE(ptrace(PTRACE_ATTACH, pid, 0, 0) == 0); 1382 1383 // Wait for the process to get to a stopping point. 1384 WaitForStop(pid); 1385 1386 std::unique_ptr<Backtrace> backtrace(Backtrace::Create(pid, BACKTRACE_CURRENT_THREAD)); 1387 ASSERT_TRUE(backtrace.get() != nullptr); 1388 ASSERT_TRUE(backtrace->Unwind(0)); 1389 ASSERT_EQ(BACKTRACE_UNWIND_NO_ERROR, backtrace->GetError()); 1390 1391 size_t frame_num; 1392 if (FindFuncFrameInBacktrace(backtrace.get(), 1393 reinterpret_cast<uintptr_t>(test_func), &frame_num)) { 1394 1395 VerifyUnreadableElfFrame(backtrace.get(), reinterpret_cast<uintptr_t>(test_func), frame_num); 1396 done = true; 1397 } 1398 1399 ASSERT_TRUE(ptrace(PTRACE_DETACH, pid, 0, 0) == 0); 1400 1401 if ((NanoTime() - start) > 5 * NS_PER_SEC) { 1402 break; 1403 } 1404 usleep(US_PER_MSEC); 1405 } 1406 1407 kill(pid, SIGKILL); 1408 ASSERT_EQ(waitpid(pid, nullptr, 0), pid); 1409 1410 ASSERT_TRUE(done) << "Test function never found in unwind."; 1411 } 1412 1413 TEST(libbacktrace, unwind_thread_doesnt_exist) { 1414 std::unique_ptr<Backtrace> backtrace( 1415 Backtrace::Create(BACKTRACE_CURRENT_PROCESS, 99999999)); 1416 ASSERT_TRUE(backtrace.get() != nullptr); 1417 ASSERT_FALSE(backtrace->Unwind(0)); 1418 ASSERT_EQ(BACKTRACE_UNWIND_ERROR_THREAD_DOESNT_EXIST, backtrace->GetError()); 1419 } 1420 1421 #if defined(ENABLE_PSS_TESTS) 1422 #include "GetPss.h" 1423 1424 #define MAX_LEAK_BYTES 32*1024UL 1425 1426 void CheckForLeak(pid_t pid, pid_t tid) { 1427 // Do a few runs to get the PSS stable. 1428 for (size_t i = 0; i < 100; i++) { 1429 Backtrace* backtrace = Backtrace::Create(pid, tid); 1430 ASSERT_TRUE(backtrace != nullptr); 1431 ASSERT_TRUE(backtrace->Unwind(0)); 1432 ASSERT_EQ(BACKTRACE_UNWIND_NO_ERROR, backtrace->GetError()); 1433 delete backtrace; 1434 } 1435 size_t stable_pss = GetPssBytes(); 1436 ASSERT_TRUE(stable_pss != 0); 1437 1438 // Loop enough that even a small leak should be detectable. 1439 for (size_t i = 0; i < 4096; i++) { 1440 Backtrace* backtrace = Backtrace::Create(pid, tid); 1441 ASSERT_TRUE(backtrace != nullptr); 1442 ASSERT_TRUE(backtrace->Unwind(0)); 1443 ASSERT_EQ(BACKTRACE_UNWIND_NO_ERROR, backtrace->GetError()); 1444 delete backtrace; 1445 } 1446 size_t new_pss = GetPssBytes(); 1447 ASSERT_TRUE(new_pss != 0); 1448 size_t abs_diff = (new_pss > stable_pss) ? new_pss - stable_pss : stable_pss - new_pss; 1449 // As long as the new pss is within a certain amount, consider everything okay. 1450 ASSERT_LE(abs_diff, MAX_LEAK_BYTES); 1451 } 1452 1453 TEST(libbacktrace, check_for_leak_local) { 1454 CheckForLeak(BACKTRACE_CURRENT_PROCESS, BACKTRACE_CURRENT_THREAD); 1455 } 1456 1457 TEST(libbacktrace, check_for_leak_local_thread) { 1458 thread_t thread_data = { 0, 0, 0, nullptr }; 1459 pthread_t thread; 1460 ASSERT_TRUE(pthread_create(&thread, nullptr, ThreadLevelRun, &thread_data) == 0); 1461 1462 // Wait up to 2 seconds for the tid to be set. 1463 ASSERT_TRUE(WaitForNonZero(&thread_data.state, 2)); 1464 1465 CheckForLeak(BACKTRACE_CURRENT_PROCESS, thread_data.tid); 1466 1467 // Tell the thread to exit its infinite loop. 1468 android_atomic_acquire_store(0, &thread_data.state); 1469 1470 ASSERT_TRUE(pthread_join(thread, nullptr) == 0); 1471 } 1472 1473 TEST(libbacktrace, check_for_leak_remote) { 1474 pid_t pid; 1475 1476 if ((pid = fork()) == 0) { 1477 while (true) { 1478 } 1479 _exit(0); 1480 } 1481 ASSERT_LT(0, pid); 1482 1483 ASSERT_TRUE(ptrace(PTRACE_ATTACH, pid, 0, 0) == 0); 1484 1485 // Wait for the process to get to a stopping point. 1486 WaitForStop(pid); 1487 1488 CheckForLeak(pid, BACKTRACE_CURRENT_THREAD); 1489 1490 ASSERT_TRUE(ptrace(PTRACE_DETACH, pid, 0, 0) == 0); 1491 1492 kill(pid, SIGKILL); 1493 ASSERT_EQ(waitpid(pid, nullptr, 0), pid); 1494 } 1495 #endif 1496
