| /* |
| * Copyright 2016, 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 <arpa/inet.h> |
| #include <dirent.h> |
| #include <fcntl.h> |
| #include <stdlib.h> |
| #include <sys/prctl.h> |
| #include <sys/ptrace.h> |
| #include <sys/types.h> |
| #include <sys/un.h> |
| #include <sys/wait.h> |
| #include <unistd.h> |
| |
| #include <limits> |
| #include <map> |
| #include <memory> |
| #include <set> |
| #include <vector> |
| |
| #include <android-base/errno_restorer.h> |
| #include <android-base/file.h> |
| #include <android-base/logging.h> |
| #include <android-base/macros.h> |
| #include <android-base/parseint.h> |
| #include <android-base/properties.h> |
| #include <android-base/stringprintf.h> |
| #include <android-base/strings.h> |
| #include <android-base/unique_fd.h> |
| #include <bionic/macros.h> |
| #include <bionic/reserved_signals.h> |
| #include <cutils/sockets.h> |
| #include <log/log.h> |
| #include <private/android_filesystem_config.h> |
| #include <procinfo/process.h> |
| |
| #define ATRACE_TAG ATRACE_TAG_BIONIC |
| #include <utils/Trace.h> |
| |
| #include <unwindstack/AndroidUnwinder.h> |
| #include <unwindstack/Error.h> |
| #include <unwindstack/Regs.h> |
| |
| #include "libdebuggerd/backtrace.h" |
| #include "libdebuggerd/tombstone.h" |
| #include "libdebuggerd/utility.h" |
| |
| #include "debuggerd/handler.h" |
| #include "tombstone_handler.h" |
| |
| #include "protocol.h" |
| #include "util.h" |
| |
| using android::base::ErrnoRestorer; |
| using android::base::StringPrintf; |
| using android::base::unique_fd; |
| |
| static bool pid_contains_tid(int pid_proc_fd, pid_t tid) { |
| struct stat st; |
| std::string task_path = StringPrintf("task/%d", tid); |
| return fstatat(pid_proc_fd, task_path.c_str(), &st, 0) == 0; |
| } |
| |
| static pid_t get_tracer(pid_t tracee) { |
| // Check to see if the thread is being ptraced by another process. |
| android::procinfo::ProcessInfo process_info; |
| if (android::procinfo::GetProcessInfo(tracee, &process_info)) { |
| return process_info.tracer; |
| } |
| return -1; |
| } |
| |
| // Attach to a thread, and verify that it's still a member of the given process |
| static bool ptrace_seize_thread(int pid_proc_fd, pid_t tid, std::string* error, int flags = 0) { |
| if (ptrace(PTRACE_SEIZE, tid, 0, flags) != 0) { |
| if (errno == EPERM) { |
| ErrnoRestorer errno_restorer; // In case get_tracer() fails and we fall through. |
| pid_t tracer_pid = get_tracer(tid); |
| if (tracer_pid > 0) { |
| *error = StringPrintf("failed to attach to thread %d, already traced by %d (%s)", tid, |
| tracer_pid, get_process_name(tracer_pid).c_str()); |
| return false; |
| } |
| } |
| |
| *error = StringPrintf("failed to attach to thread %d: %s", tid, strerror(errno)); |
| return false; |
| } |
| |
| // Make sure that the task we attached to is actually part of the pid we're dumping. |
| if (!pid_contains_tid(pid_proc_fd, tid)) { |
| if (ptrace(PTRACE_DETACH, tid, 0, 0) != 0) { |
| PLOG(WARNING) << "failed to detach from thread " << tid; |
| } |
| *error = StringPrintf("thread %d is not in process", tid); |
| return false; |
| } |
| |
| return true; |
| } |
| |
| static bool wait_for_stop(pid_t tid, int* received_signal) { |
| while (true) { |
| int status; |
| pid_t result = waitpid(tid, &status, __WALL); |
| if (result != tid) { |
| PLOG(ERROR) << "waitpid failed on " << tid << " while detaching"; |
| return false; |
| } |
| |
| if (WIFSTOPPED(status)) { |
| if (status >> 16 == PTRACE_EVENT_STOP) { |
| *received_signal = 0; |
| } else { |
| *received_signal = WSTOPSIG(status); |
| } |
| return true; |
| } |
| } |
| } |
| |
| // Interrupt a process and wait for it to be interrupted. |
| static bool ptrace_interrupt(pid_t tid, int* received_signal) { |
| if (ptrace(PTRACE_INTERRUPT, tid, 0, 0) == 0) { |
| return wait_for_stop(tid, received_signal); |
| } |
| |
| PLOG(ERROR) << "failed to interrupt " << tid << " to detach"; |
| return false; |
| } |
| |
| static bool activity_manager_notify(pid_t pid, int signal, const std::string& amfd_data, |
| bool recoverable_gwp_asan_crash) { |
| ATRACE_CALL(); |
| android::base::unique_fd amfd(socket_local_client( |
| "/data/system/ndebugsocket", ANDROID_SOCKET_NAMESPACE_FILESYSTEM, SOCK_STREAM)); |
| if (amfd.get() == -1) { |
| PLOG(ERROR) << "unable to connect to activity manager"; |
| return false; |
| } |
| |
| struct timeval tv = { |
| .tv_sec = 1 * android::base::HwTimeoutMultiplier(), |
| .tv_usec = 0, |
| }; |
| if (setsockopt(amfd.get(), SOL_SOCKET, SO_SNDTIMEO, &tv, sizeof(tv)) == -1) { |
| PLOG(ERROR) << "failed to set send timeout on activity manager socket"; |
| return false; |
| } |
| tv.tv_sec = 3 * android::base::HwTimeoutMultiplier(); // 3 seconds on handshake read |
| if (setsockopt(amfd.get(), SOL_SOCKET, SO_RCVTIMEO, &tv, sizeof(tv)) == -1) { |
| PLOG(ERROR) << "failed to set receive timeout on activity manager socket"; |
| return false; |
| } |
| |
| // Activity Manager protocol: |
| // - 32-bit network-byte-order: pid |
| // - 32-bit network-byte-order: signal number |
| // - byte: recoverable_gwp_asan_crash |
| // - bytes: raw text of the dump |
| // - null terminator |
| |
| uint32_t datum = htonl(pid); |
| if (!android::base::WriteFully(amfd, &datum, sizeof(datum))) { |
| PLOG(ERROR) << "AM pid write failed"; |
| return false; |
| } |
| |
| datum = htonl(signal); |
| if (!android::base::WriteFully(amfd, &datum, sizeof(datum))) { |
| PLOG(ERROR) << "AM signo write failed"; |
| return false; |
| } |
| |
| uint8_t recoverable_gwp_asan_crash_byte = recoverable_gwp_asan_crash ? 1 : 0; |
| if (!android::base::WriteFully(amfd, &recoverable_gwp_asan_crash_byte, |
| sizeof(recoverable_gwp_asan_crash_byte))) { |
| PLOG(ERROR) << "AM recoverable_gwp_asan_crash_byte write failed"; |
| return false; |
| } |
| |
| if (!android::base::WriteFully(amfd, amfd_data.c_str(), amfd_data.size() + 1)) { |
| PLOG(ERROR) << "AM data write failed"; |
| return false; |
| } |
| |
| // 3 sec timeout reading the ack; we're fine if the read fails. |
| char ack; |
| android::base::ReadFully(amfd, &ack, 1); |
| return true; |
| } |
| |
| // Globals used by the abort handler. |
| static pid_t g_target_thread = -1; |
| static bool g_tombstoned_connected = false; |
| static unique_fd g_tombstoned_socket; |
| static unique_fd g_output_fd; |
| static unique_fd g_proto_fd; |
| |
| static void DefuseSignalHandlers() { |
| // Don't try to dump ourselves. |
| struct sigaction action = {}; |
| action.sa_handler = SIG_DFL; |
| debuggerd_register_handlers(&action); |
| |
| sigset_t mask; |
| sigemptyset(&mask); |
| if (sigprocmask(SIG_SETMASK, &mask, nullptr) != 0) { |
| PLOG(FATAL) << "failed to set signal mask"; |
| } |
| } |
| |
| static void Initialize(char** argv) { |
| android::base::InitLogging(argv); |
| android::base::SetAborter([](const char* abort_msg) { |
| // If we abort before we get an output fd, contact tombstoned to let any |
| // potential listeners know that we failed. |
| if (!g_tombstoned_connected) { |
| if (!connect_tombstone_server(g_target_thread, &g_tombstoned_socket, &g_output_fd, |
| &g_proto_fd, kDebuggerdAnyIntercept)) { |
| // We failed to connect, not much we can do. |
| LOG(ERROR) << "failed to connected to tombstoned to report failure"; |
| _exit(1); |
| } |
| } |
| |
| dprintf(g_output_fd.get(), "crash_dump failed to dump process"); |
| if (g_target_thread != 1) { |
| dprintf(g_output_fd.get(), " %d: %s\n", g_target_thread, abort_msg); |
| } else { |
| dprintf(g_output_fd.get(), ": %s\n", abort_msg); |
| } |
| |
| _exit(1); |
| }); |
| } |
| |
| static void ParseArgs(int argc, char** argv, pid_t* pseudothread_tid, DebuggerdDumpType* dump_type) { |
| if (argc != 4) { |
| LOG(FATAL) << "wrong number of args: " << argc << " (expected 4)"; |
| } |
| |
| if (!android::base::ParseInt(argv[1], &g_target_thread, 1, std::numeric_limits<pid_t>::max())) { |
| LOG(FATAL) << "invalid target tid: " << argv[1]; |
| } |
| |
| if (!android::base::ParseInt(argv[2], pseudothread_tid, 1, std::numeric_limits<pid_t>::max())) { |
| LOG(FATAL) << "invalid pseudothread tid: " << argv[2]; |
| } |
| |
| int dump_type_int; |
| if (!android::base::ParseInt(argv[3], &dump_type_int, 0)) { |
| LOG(FATAL) << "invalid requested dump type: " << argv[3]; |
| } |
| |
| *dump_type = static_cast<DebuggerdDumpType>(dump_type_int); |
| switch (*dump_type) { |
| case kDebuggerdNativeBacktrace: |
| case kDebuggerdTombstone: |
| case kDebuggerdTombstoneProto: |
| break; |
| |
| default: |
| LOG(FATAL) << "invalid requested dump type: " << dump_type_int; |
| } |
| } |
| |
| static void ReadCrashInfo(unique_fd& fd, siginfo_t* siginfo, |
| std::unique_ptr<unwindstack::Regs>* regs, ProcessInfo* process_info, |
| bool* recoverable_gwp_asan_crash) { |
| std::aligned_storage<sizeof(CrashInfo) + 1, alignof(CrashInfo)>::type buf; |
| CrashInfo* crash_info = reinterpret_cast<CrashInfo*>(&buf); |
| ssize_t rc = TEMP_FAILURE_RETRY(read(fd.get(), &buf, sizeof(buf))); |
| *recoverable_gwp_asan_crash = false; |
| if (rc == -1) { |
| PLOG(FATAL) << "failed to read target ucontext"; |
| } else { |
| ssize_t expected_size = 0; |
| switch (crash_info->header.version) { |
| case 1: |
| case 2: |
| case 3: |
| expected_size = sizeof(CrashInfoHeader) + sizeof(CrashInfoDataStatic); |
| break; |
| |
| case 4: |
| expected_size = sizeof(CrashInfoHeader) + sizeof(CrashInfoDataDynamic); |
| break; |
| |
| default: |
| LOG(FATAL) << "unexpected CrashInfo version: " << crash_info->header.version; |
| break; |
| }; |
| |
| if (rc < expected_size) { |
| LOG(FATAL) << "read " << rc << " bytes when reading target crash information, expected " |
| << expected_size; |
| } |
| } |
| |
| switch (crash_info->header.version) { |
| case 4: |
| process_info->fdsan_table_address = crash_info->data.d.fdsan_table_address; |
| process_info->gwp_asan_state = crash_info->data.d.gwp_asan_state; |
| process_info->gwp_asan_metadata = crash_info->data.d.gwp_asan_metadata; |
| process_info->scudo_stack_depot = crash_info->data.d.scudo_stack_depot; |
| process_info->scudo_region_info = crash_info->data.d.scudo_region_info; |
| process_info->scudo_ring_buffer = crash_info->data.d.scudo_ring_buffer; |
| process_info->scudo_ring_buffer_size = crash_info->data.d.scudo_ring_buffer_size; |
| *recoverable_gwp_asan_crash = crash_info->data.d.recoverable_gwp_asan_crash; |
| FALLTHROUGH_INTENDED; |
| case 1: |
| case 2: |
| case 3: |
| process_info->abort_msg_address = crash_info->data.s.abort_msg_address; |
| *siginfo = crash_info->data.s.siginfo; |
| if (signal_has_si_addr(siginfo)) { |
| process_info->has_fault_address = true; |
| process_info->maybe_tagged_fault_address = reinterpret_cast<uintptr_t>(siginfo->si_addr); |
| process_info->untagged_fault_address = |
| untag_address(reinterpret_cast<uintptr_t>(siginfo->si_addr)); |
| } |
| regs->reset(unwindstack::Regs::CreateFromUcontext(unwindstack::Regs::CurrentArch(), |
| &crash_info->data.s.ucontext)); |
| break; |
| |
| default: |
| __builtin_unreachable(); |
| } |
| } |
| |
| // Wait for a process to clone and return the child's pid. |
| // Note: this leaves the parent in PTRACE_EVENT_STOP. |
| static pid_t wait_for_clone(pid_t pid, bool resume_child) { |
| int status; |
| pid_t result = TEMP_FAILURE_RETRY(waitpid(pid, &status, __WALL)); |
| if (result == -1) { |
| PLOG(FATAL) << "failed to waitpid"; |
| } |
| |
| if (WIFEXITED(status)) { |
| LOG(FATAL) << "traced process exited with status " << WEXITSTATUS(status); |
| } else if (WIFSIGNALED(status)) { |
| LOG(FATAL) << "traced process exited with signal " << WTERMSIG(status); |
| } else if (!WIFSTOPPED(status)) { |
| LOG(FATAL) << "process didn't stop? (status = " << status << ")"; |
| } |
| |
| if (status >> 8 != (SIGTRAP | (PTRACE_EVENT_CLONE << 8))) { |
| LOG(FATAL) << "process didn't stop due to PTRACE_O_TRACECLONE (status = " << status << ")"; |
| } |
| |
| pid_t child; |
| if (ptrace(PTRACE_GETEVENTMSG, pid, 0, &child) != 0) { |
| PLOG(FATAL) << "failed to get child pid via PTRACE_GETEVENTMSG"; |
| } |
| |
| int stop_signal; |
| if (!wait_for_stop(child, &stop_signal)) { |
| PLOG(FATAL) << "failed to waitpid on child"; |
| } |
| |
| CHECK_EQ(0, stop_signal); |
| |
| if (resume_child) { |
| if (ptrace(PTRACE_CONT, child, 0, 0) != 0) { |
| PLOG(FATAL) << "failed to resume child (pid = " << child << ")"; |
| } |
| } |
| |
| return child; |
| } |
| |
| static pid_t wait_for_vm_process(pid_t pseudothread_tid) { |
| // The pseudothread will double-fork, we want its grandchild. |
| pid_t intermediate = wait_for_clone(pseudothread_tid, true); |
| pid_t vm_pid = wait_for_clone(intermediate, false); |
| if (ptrace(PTRACE_DETACH, intermediate, 0, 0) != 0) { |
| PLOG(FATAL) << "failed to detach from intermediate vm process"; |
| } |
| |
| return vm_pid; |
| } |
| |
| static void InstallSigPipeHandler() { |
| struct sigaction action = {}; |
| action.sa_handler = SIG_IGN; |
| action.sa_flags = SA_RESTART; |
| sigaction(SIGPIPE, &action, nullptr); |
| } |
| |
| int main(int argc, char** argv) { |
| DefuseSignalHandlers(); |
| InstallSigPipeHandler(); |
| |
| // There appears to be a bug in the kernel where our death causes SIGHUP to |
| // be sent to our process group if we exit while it has stopped jobs (e.g. |
| // because of wait_for_debugger). Use setsid to create a new process group to |
| // avoid hitting this. |
| setsid(); |
| |
| atrace_begin(ATRACE_TAG, "before reparent"); |
| pid_t target_process = getppid(); |
| |
| // Open /proc/`getppid()` before we daemonize. |
| std::string target_proc_path = "/proc/" + std::to_string(target_process); |
| int target_proc_fd = open(target_proc_path.c_str(), O_DIRECTORY | O_RDONLY); |
| if (target_proc_fd == -1) { |
| PLOG(FATAL) << "failed to open " << target_proc_path; |
| } |
| |
| // Make sure getppid() hasn't changed. |
| if (getppid() != target_process) { |
| LOG(FATAL) << "parent died"; |
| } |
| atrace_end(ATRACE_TAG); |
| |
| // Reparent ourselves to init, so that the signal handler can waitpid on the |
| // original process to avoid leaving a zombie for non-fatal dumps. |
| // Move the input/output pipes off of stdout/stderr, out of paranoia. |
| unique_fd output_pipe(dup(STDOUT_FILENO)); |
| unique_fd input_pipe(dup(STDIN_FILENO)); |
| |
| unique_fd fork_exit_read, fork_exit_write; |
| if (!Pipe(&fork_exit_read, &fork_exit_write)) { |
| PLOG(FATAL) << "failed to create pipe"; |
| } |
| |
| pid_t forkpid = fork(); |
| if (forkpid == -1) { |
| PLOG(FATAL) << "fork failed"; |
| } else if (forkpid == 0) { |
| fork_exit_read.reset(); |
| } else { |
| // We need the pseudothread to live until we get around to verifying the vm pid against it. |
| // The last thing it does is block on a waitpid on us, so wait until our child tells us to die. |
| fork_exit_write.reset(); |
| char buf; |
| TEMP_FAILURE_RETRY(read(fork_exit_read.get(), &buf, sizeof(buf))); |
| _exit(0); |
| } |
| |
| ATRACE_NAME("after reparent"); |
| pid_t pseudothread_tid; |
| DebuggerdDumpType dump_type; |
| ProcessInfo process_info; |
| |
| Initialize(argv); |
| ParseArgs(argc, argv, &pseudothread_tid, &dump_type); |
| |
| // Die if we take too long. |
| // |
| // Note: processes with many threads and minidebug-info can take a bit to |
| // unwind, do not make this too small. b/62828735 |
| alarm(30 * android::base::HwTimeoutMultiplier()); |
| |
| // Collect the list of open files. |
| OpenFilesList open_files; |
| { |
| ATRACE_NAME("open files"); |
| populate_open_files_list(&open_files, g_target_thread); |
| } |
| |
| // In order to reduce the duration that we pause the process for, we ptrace |
| // the threads, fetch their registers and associated information, and then |
| // fork a separate process as a snapshot of the process's address space. |
| std::set<pid_t> threads; |
| if (!android::procinfo::GetProcessTids(g_target_thread, &threads)) { |
| PLOG(FATAL) << "failed to get process threads"; |
| } |
| |
| std::map<pid_t, ThreadInfo> thread_info; |
| siginfo_t siginfo; |
| std::string error; |
| bool recoverable_gwp_asan_crash = false; |
| |
| { |
| ATRACE_NAME("ptrace"); |
| for (pid_t thread : threads) { |
| // Trace the pseudothread separately, so we can use different options. |
| if (thread == pseudothread_tid) { |
| continue; |
| } |
| |
| if (!ptrace_seize_thread(target_proc_fd, thread, &error)) { |
| bool fatal = thread == g_target_thread; |
| LOG(fatal ? FATAL : WARNING) << error; |
| } |
| |
| ThreadInfo info; |
| info.pid = target_process; |
| info.tid = thread; |
| info.uid = getuid(); |
| info.thread_name = get_thread_name(thread); |
| |
| unique_fd attr_fd(openat(target_proc_fd, "attr/current", O_RDONLY | O_CLOEXEC)); |
| if (!android::base::ReadFdToString(attr_fd, &info.selinux_label)) { |
| PLOG(WARNING) << "failed to read selinux label"; |
| } |
| |
| if (!ptrace_interrupt(thread, &info.signo)) { |
| PLOG(WARNING) << "failed to ptrace interrupt thread " << thread; |
| ptrace(PTRACE_DETACH, thread, 0, 0); |
| continue; |
| } |
| |
| struct iovec tagged_addr_iov = { |
| &info.tagged_addr_ctrl, |
| sizeof(info.tagged_addr_ctrl), |
| }; |
| if (ptrace(PTRACE_GETREGSET, thread, NT_ARM_TAGGED_ADDR_CTRL, |
| reinterpret_cast<void*>(&tagged_addr_iov)) == -1) { |
| info.tagged_addr_ctrl = -1; |
| } |
| |
| struct iovec pac_enabled_keys_iov = { |
| &info.pac_enabled_keys, |
| sizeof(info.pac_enabled_keys), |
| }; |
| if (ptrace(PTRACE_GETREGSET, thread, NT_ARM_PAC_ENABLED_KEYS, |
| reinterpret_cast<void*>(&pac_enabled_keys_iov)) == -1) { |
| info.pac_enabled_keys = -1; |
| } |
| |
| if (thread == g_target_thread) { |
| // Read the thread's registers along with the rest of the crash info out of the pipe. |
| ReadCrashInfo(input_pipe, &siginfo, &info.registers, &process_info, |
| &recoverable_gwp_asan_crash); |
| info.siginfo = &siginfo; |
| info.signo = info.siginfo->si_signo; |
| |
| info.command_line = get_command_line(g_target_thread); |
| } else { |
| info.registers.reset(unwindstack::Regs::RemoteGet(thread)); |
| if (!info.registers) { |
| PLOG(WARNING) << "failed to fetch registers for thread " << thread; |
| ptrace(PTRACE_DETACH, thread, 0, 0); |
| continue; |
| } |
| } |
| |
| thread_info[thread] = std::move(info); |
| } |
| } |
| |
| // Trace the pseudothread with PTRACE_O_TRACECLONE and tell it to fork. |
| if (!ptrace_seize_thread(target_proc_fd, pseudothread_tid, &error, PTRACE_O_TRACECLONE)) { |
| LOG(FATAL) << "failed to seize pseudothread: " << error; |
| } |
| |
| if (TEMP_FAILURE_RETRY(write(output_pipe.get(), "\1", 1)) != 1) { |
| PLOG(FATAL) << "failed to write to pseudothread"; |
| } |
| |
| pid_t vm_pid = wait_for_vm_process(pseudothread_tid); |
| if (ptrace(PTRACE_DETACH, pseudothread_tid, 0, 0) != 0) { |
| PLOG(FATAL) << "failed to detach from pseudothread"; |
| } |
| |
| // The pseudothread can die now. |
| fork_exit_write.reset(); |
| |
| // Defer the message until later, for readability. |
| bool wait_for_debugger = android::base::GetBoolProperty( |
| "debug.debuggerd.wait_for_debugger", |
| android::base::GetBoolProperty("debug.debuggerd.wait_for_gdb", false)); |
| if (siginfo.si_signo == BIONIC_SIGNAL_DEBUGGER) { |
| wait_for_debugger = false; |
| } |
| |
| // Detach from all of our attached threads before resuming. |
| for (const auto& [tid, thread] : thread_info) { |
| int resume_signal = thread.signo == BIONIC_SIGNAL_DEBUGGER ? 0 : thread.signo; |
| if (wait_for_debugger) { |
| resume_signal = 0; |
| if (tgkill(target_process, tid, SIGSTOP) != 0) { |
| PLOG(WARNING) << "failed to send SIGSTOP to " << tid; |
| } |
| } |
| |
| LOG(DEBUG) << "detaching from thread " << tid; |
| if (ptrace(PTRACE_DETACH, tid, 0, resume_signal) != 0) { |
| PLOG(ERROR) << "failed to detach from thread " << tid; |
| } |
| } |
| |
| // Drop our capabilities now that we've fetched all of the information we need. |
| drop_capabilities(); |
| |
| { |
| ATRACE_NAME("tombstoned_connect"); |
| LOG(INFO) << "obtaining output fd from tombstoned, type: " << dump_type; |
| g_tombstoned_connected = connect_tombstone_server(g_target_thread, &g_tombstoned_socket, |
| &g_output_fd, &g_proto_fd, dump_type); |
| } |
| |
| if (g_tombstoned_connected) { |
| if (TEMP_FAILURE_RETRY(dup2(g_output_fd.get(), STDOUT_FILENO)) == -1) { |
| PLOG(ERROR) << "failed to dup2 output fd (" << g_output_fd.get() << ") to STDOUT_FILENO"; |
| } |
| } else { |
| unique_fd devnull(TEMP_FAILURE_RETRY(open("/dev/null", O_RDWR))); |
| TEMP_FAILURE_RETRY(dup2(devnull.get(), STDOUT_FILENO)); |
| g_output_fd = std::move(devnull); |
| } |
| |
| LOG(INFO) << "performing dump of process " << target_process |
| << " (target tid = " << g_target_thread << ")"; |
| |
| int signo = siginfo.si_signo; |
| bool fatal_signal = signo != BIONIC_SIGNAL_DEBUGGER; |
| bool backtrace = false; |
| |
| // si_value is special when used with BIONIC_SIGNAL_DEBUGGER. |
| // 0: dump tombstone |
| // 1: dump backtrace |
| if (!fatal_signal) { |
| int si_val = siginfo.si_value.sival_int; |
| if (si_val == 0) { |
| backtrace = false; |
| } else if (si_val == 1) { |
| backtrace = true; |
| } else { |
| LOG(WARNING) << "unknown si_value value " << si_val; |
| } |
| } |
| |
| // TODO: Use seccomp to lock ourselves down. |
| |
| unwindstack::AndroidRemoteUnwinder unwinder(vm_pid, unwindstack::Regs::CurrentArch()); |
| unwindstack::ErrorData error_data; |
| if (!unwinder.Initialize(error_data)) { |
| LOG(FATAL) << "Failed to initialize unwinder object: " |
| << unwindstack::GetErrorCodeString(error_data.code); |
| } |
| |
| std::string amfd_data; |
| if (backtrace) { |
| ATRACE_NAME("dump_backtrace"); |
| dump_backtrace(std::move(g_output_fd), &unwinder, thread_info, g_target_thread); |
| } else { |
| { |
| ATRACE_NAME("fdsan table dump"); |
| populate_fdsan_table(&open_files, unwinder.GetProcessMemory(), |
| process_info.fdsan_table_address); |
| } |
| |
| { |
| ATRACE_NAME("engrave_tombstone"); |
| engrave_tombstone(std::move(g_output_fd), std::move(g_proto_fd), &unwinder, thread_info, |
| g_target_thread, process_info, &open_files, &amfd_data); |
| } |
| } |
| |
| if (fatal_signal) { |
| // Don't try to notify ActivityManager if it just crashed, or we might hang until timeout. |
| if (thread_info[target_process].thread_name != "system_server") { |
| activity_manager_notify(target_process, signo, amfd_data, recoverable_gwp_asan_crash); |
| } |
| } |
| |
| if (wait_for_debugger) { |
| // Use ALOGI to line up with output from engrave_tombstone. |
| ALOGI( |
| "***********************************************************\n" |
| "* Process %d has been suspended while crashing.\n" |
| "* To attach the debugger, run this on the host:\n" |
| "*\n" |
| "* lldbclient.py -p %d\n" |
| "*\n" |
| "***********************************************************", |
| target_process, target_process); |
| } |
| |
| // Close stdout before we notify tombstoned of completion. |
| close(STDOUT_FILENO); |
| if (g_tombstoned_connected && |
| !notify_completion(g_tombstoned_socket.get(), g_output_fd.get(), g_proto_fd.get())) { |
| LOG(ERROR) << "failed to notify tombstoned of completion"; |
| } |
| |
| return 0; |
| } |