Reland protobuf tombstones.

This reverts the following commits:
    e156ede145a7fc671c705d045d89b49922a758b5.
    eda96eddcbdda9632166232b2363c7b84da0994d.
    5ec54d1e843729cd1e38a2f791f001226a653e95.
    1e45d3f2239333217d3252f78151f4294fda4e80.
    a50f61f8fa903117a6df82d164628de310f16ae9.

Test: treehugger
Test: atest -c CtsSeccompHostTestCases:android.seccomp.cts.SeccompHostJUnit4DeviceTest#testAppZygoteSyscalls
Change-Id: Ic2b1f489ac9f1fec7d7a33c845c29891f4306bbd
diff --git a/debuggerd/libdebuggerd/include/libdebuggerd/tombstone.h b/debuggerd/libdebuggerd/include/libdebuggerd/tombstone.h
index 3ff7d62..bf2cbb3 100644
--- a/debuggerd/libdebuggerd/include/libdebuggerd/tombstone.h
+++ b/debuggerd/libdebuggerd/include/libdebuggerd/tombstone.h
@@ -21,6 +21,7 @@
 #include <stddef.h>
 #include <sys/types.h>
 
+#include <functional>
 #include <map>
 #include <string>
 
@@ -30,6 +31,8 @@
 #include "types.h"
 
 // Forward declarations
+class Tombstone;
+
 namespace unwindstack {
 class Unwinder;
 }
@@ -44,13 +47,21 @@
 int open_tombstone(std::string* path);
 
 /* Creates a tombstone file and writes the crash dump to it. */
-void engrave_tombstone(android::base::unique_fd output_fd, unwindstack::Unwinder* unwinder,
+void engrave_tombstone(android::base::unique_fd output_fd, android::base::unique_fd proto_fd,
+                       unwindstack::Unwinder* unwinder,
                        const std::map<pid_t, ThreadInfo>& thread_info, pid_t target_thread,
                        const ProcessInfo& process_info, OpenFilesList* open_files,
                        std::string* amfd_data);
 
-void engrave_tombstone_ucontext(int tombstone_fd, uint64_t abort_msg_address, siginfo_t* siginfo,
-                                ucontext_t* ucontext);
+void engrave_tombstone_ucontext(int tombstone_fd, int proto_fd, uint64_t abort_msg_address,
+                                siginfo_t* siginfo, ucontext_t* ucontext);
 
+void engrave_tombstone_proto(Tombstone* tombstone, unwindstack::Unwinder* unwinder,
+                             const std::map<pid_t, ThreadInfo>& threads, pid_t target_thread,
+                             const ProcessInfo& process_info, const OpenFilesList* open_files);
+
+bool tombstone_proto_to_text(
+    const Tombstone& tombstone,
+    std::function<void(const std::string& line, bool should_log)> callback);
 
 #endif  // _DEBUGGERD_TOMBSTONE_H
diff --git a/debuggerd/libdebuggerd/include/libdebuggerd/types.h b/debuggerd/libdebuggerd/include/libdebuggerd/types.h
index 86522ee..d5b0735 100644
--- a/debuggerd/libdebuggerd/include/libdebuggerd/types.h
+++ b/debuggerd/libdebuggerd/include/libdebuggerd/types.h
@@ -31,7 +31,9 @@
   std::string thread_name;
 
   pid_t pid;
+
   std::string process_name;
+  std::string selinux_label;
 
   int signo = 0;
   siginfo_t* siginfo = nullptr;
diff --git a/debuggerd/libdebuggerd/include/libdebuggerd/utility.h b/debuggerd/libdebuggerd/include/libdebuggerd/utility.h
index 29fb9a4..d71b76f 100644
--- a/debuggerd/libdebuggerd/include/libdebuggerd/utility.h
+++ b/debuggerd/libdebuggerd/include/libdebuggerd/utility.h
@@ -81,6 +81,8 @@
 
 void log_backtrace(log_t* log, unwindstack::Unwinder* unwinder, const char* prefix);
 
+ssize_t dump_memory(void* out, size_t len, size_t* start_offset, uint64_t* addr,
+                    unwindstack::Memory* memory);
 void dump_memory(log_t* log, unwindstack::Memory* backtrace, uint64_t addr, const std::string&);
 
 void drop_capabilities();
diff --git a/debuggerd/libdebuggerd/tombstone.cpp b/debuggerd/libdebuggerd/tombstone.cpp
index 4bd7192..822b74a 100644
--- a/debuggerd/libdebuggerd/tombstone.cpp
+++ b/debuggerd/libdebuggerd/tombstone.cpp
@@ -63,6 +63,8 @@
 #include "gwp_asan/common.h"
 #include "gwp_asan/crash_handler.h"
 
+#include "tombstone.pb.h"
+
 using android::base::GetBoolProperty;
 using android::base::GetProperty;
 using android::base::StringPrintf;
@@ -190,8 +192,7 @@
 static std::string get_addr_string(uint64_t addr) {
   std::string addr_str;
 #if defined(__LP64__)
-  addr_str = StringPrintf("%08x'%08x",
-                          static_cast<uint32_t>(addr >> 32),
+  addr_str = StringPrintf("%08x'%08x", static_cast<uint32_t>(addr >> 32),
                           static_cast<uint32_t>(addr & 0xffffffff));
 #else
   addr_str = StringPrintf("%08x", static_cast<uint32_t>(addr));
@@ -394,8 +395,7 @@
   if (primary_thread && gwp_asan_crash_data->CrashIsMine()) {
     gwp_asan_crash_data->DumpCause(log);
   } else if (thread_info.siginfo && !(primary_thread && scudo_crash_data->CrashIsMine())) {
-    dump_probable_cause(log, thread_info.siginfo, unwinder->GetMaps(),
-                        thread_info.registers.get());
+    dump_probable_cause(log, thread_info.siginfo, unwinder->GetMaps(), thread_info.registers.get());
   }
 
   if (primary_thread) {
@@ -492,8 +492,7 @@
     // the tombstone file.
 
     if (first) {
-      _LOG(log, logtype::LOGS, "--------- %slog %s\n",
-        tail ? "tail end of " : "", filename);
+      _LOG(log, logtype::LOGS, "--------- %slog %s\n", tail ? "tail end of " : "", filename);
       first = false;
     }
 
@@ -554,8 +553,8 @@
   dump_log_file(log, pid, "main", tail);
 }
 
-void engrave_tombstone_ucontext(int tombstone_fd, uint64_t abort_msg_address, siginfo_t* siginfo,
-                                ucontext_t* ucontext) {
+void engrave_tombstone_ucontext(int tombstone_fd, int proto_fd, uint64_t abort_msg_address,
+                                siginfo_t* siginfo, ucontext_t* ucontext) {
   pid_t uid = getuid();
   pid_t pid = getpid();
   pid_t tid = gettid();
@@ -572,14 +571,18 @@
   std::unique_ptr<unwindstack::Regs> regs(
       unwindstack::Regs::CreateFromUcontext(unwindstack::Regs::CurrentArch(), ucontext));
 
+  std::string selinux_label;
+  android::base::ReadFileToString("/proc/self/attr/current", &selinux_label);
+
   std::map<pid_t, ThreadInfo> threads;
   threads[tid] = ThreadInfo{
       .registers = std::move(regs),
       .uid = uid,
       .tid = tid,
-      .thread_name = thread_name.c_str(),
+      .thread_name = std::move(thread_name),
       .pid = pid,
-      .process_name = process_name.c_str(),
+      .process_name = std::move(process_name),
+      .selinux_label = std::move(selinux_label),
       .siginfo = siginfo,
   };
 
@@ -589,17 +592,23 @@
   }
 
   ProcessInfo process_info;
+  unique_fd attr_fd(open("/proc/self/attr/current", O_RDONLY | O_CLOEXEC));
   process_info.abort_msg_address = abort_msg_address;
-  engrave_tombstone(unique_fd(dup(tombstone_fd)), &unwinder, threads, tid, process_info, nullptr,
-                    nullptr);
+  engrave_tombstone(unique_fd(dup(tombstone_fd)), unique_fd(dup(proto_fd)), &unwinder, threads, tid,
+                    process_info, nullptr, nullptr);
 }
 
-void engrave_tombstone(unique_fd output_fd, unwindstack::Unwinder* unwinder,
+void engrave_tombstone(unique_fd output_fd, unique_fd proto_fd, unwindstack::Unwinder* unwinder,
                        const std::map<pid_t, ThreadInfo>& threads, pid_t target_thread,
                        const ProcessInfo& process_info, OpenFilesList* open_files,
                        std::string* amfd_data) {
   // Don't copy log messages to tombstone unless this is a development device.
-  bool want_logs = GetBoolProperty("ro.debuggable", false);
+  Tombstone tombstone;
+  engrave_tombstone_proto(&tombstone, unwinder, threads, target_thread, process_info, open_files);
+
+  if (!tombstone.SerializeToFileDescriptor(proto_fd.get())) {
+    PLOG(ERROR) << "Failed to write proto tombstone";
+  }
 
   log_t log;
   log.current_tid = target_thread;
@@ -607,35 +616,45 @@
   log.tfd = output_fd.get();
   log.amfd_data = amfd_data;
 
-  _LOG(&log, logtype::HEADER, "*** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***\n");
-  dump_header_info(&log);
-  _LOG(&log, logtype::HEADER, "Timestamp: %s\n", get_timestamp().c_str());
+  bool translate_proto = GetBoolProperty("debug.debuggerd.translate_proto_to_text", false);
+  if (translate_proto) {
+    tombstone_proto_to_text(tombstone, [&log](const std::string& line, bool should_log) {
+      _LOG(&log, should_log ? logtype::HEADER : logtype::LOGS, "%s\n", line.c_str());
+    });
+  } else {
+    bool want_logs = GetBoolProperty("ro.debuggable", false);
 
-  auto it = threads.find(target_thread);
-  if (it == threads.end()) {
-    LOG(FATAL) << "failed to find target thread";
-  }
+    _LOG(&log, logtype::HEADER,
+         "*** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***\n");
+    dump_header_info(&log);
+    _LOG(&log, logtype::HEADER, "Timestamp: %s\n", get_timestamp().c_str());
 
-  dump_thread(&log, unwinder, it->second, process_info, true);
-
-  if (want_logs) {
-    dump_logs(&log, it->second.pid, 50);
-  }
-
-  for (auto& [tid, thread_info] : threads) {
-    if (tid == target_thread) {
-      continue;
+    auto it = threads.find(target_thread);
+    if (it == threads.end()) {
+      LOG(FATAL) << "failed to find target thread";
     }
 
-    dump_thread(&log, unwinder, thread_info, process_info, false);
-  }
+    dump_thread(&log, unwinder, it->second, process_info, true);
 
-  if (open_files) {
-    _LOG(&log, logtype::OPEN_FILES, "\nopen files:\n");
-    dump_open_files_list(&log, *open_files, "    ");
-  }
+    if (want_logs) {
+      dump_logs(&log, it->second.pid, 50);
+    }
 
-  if (want_logs) {
-    dump_logs(&log, it->second.pid, 0);
+    for (auto& [tid, thread_info] : threads) {
+      if (tid == target_thread) {
+        continue;
+      }
+
+      dump_thread(&log, unwinder, thread_info, process_info, false);
+    }
+
+    if (open_files) {
+      _LOG(&log, logtype::OPEN_FILES, "\nopen files:\n");
+      dump_open_files_list(&log, *open_files, "    ");
+    }
+
+    if (want_logs) {
+      dump_logs(&log, it->second.pid, 0);
+    }
   }
 }
diff --git a/debuggerd/libdebuggerd/tombstone_proto.cpp b/debuggerd/libdebuggerd/tombstone_proto.cpp
new file mode 100644
index 0000000..801b112
--- /dev/null
+++ b/debuggerd/libdebuggerd/tombstone_proto.cpp
@@ -0,0 +1,478 @@
+/*
+ * Copyright (C) 2020 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.
+ */
+
+#define LOG_TAG "DEBUG"
+
+#include "libdebuggerd/tombstone.h"
+
+#include <errno.h>
+#include <fcntl.h>
+#include <inttypes.h>
+#include <signal.h>
+#include <stddef.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/mman.h>
+#include <time.h>
+
+#include <memory>
+#include <string>
+
+#include <android-base/logging.h>
+#include <android-base/properties.h>
+#include <android-base/stringprintf.h>
+#include <android-base/strings.h>
+#include <android-base/unique_fd.h>
+
+#include <android/log.h>
+#include <log/log.h>
+#include <log/log_read.h>
+#include <log/logprint.h>
+#include <private/android_filesystem_config.h>
+
+#include <unwindstack/Maps.h>
+#include <unwindstack/Memory.h>
+#include <unwindstack/Regs.h>
+#include <unwindstack/Unwinder.h>
+
+#include "libdebuggerd/open_files_list.h"
+#include "libdebuggerd/utility.h"
+#include "util.h"
+
+#include "tombstone.pb.h"
+
+using android::base::StringPrintf;
+
+// Use the demangler from libc++.
+extern "C" char* __cxa_demangle(const char*, char*, size_t*, int* status);
+
+static Architecture get_arch() {
+#if defined(__arm__)
+  return Architecture::ARM32;
+#elif defined(__aarch64__)
+  return Architecture::ARM64;
+#elif defined(__i386__)
+  return Architecture::X86;
+#elif defined(__x86_64__)
+  return Architecture::X86_64;
+#else
+#error Unknown architecture!
+#endif
+}
+
+static std::optional<std::string> get_stack_overflow_cause(uint64_t fault_addr, uint64_t sp,
+                                                           unwindstack::Maps* maps) {
+  static constexpr uint64_t kMaxDifferenceBytes = 256;
+  uint64_t difference;
+  if (sp >= fault_addr) {
+    difference = sp - fault_addr;
+  } else {
+    difference = fault_addr - sp;
+  }
+  if (difference <= kMaxDifferenceBytes) {
+    // The faulting address is close to the current sp, check if the sp
+    // indicates a stack overflow.
+    // On arm, the sp does not get updated when the instruction faults.
+    // In this case, the sp will still be in a valid map, which is the
+    // last case below.
+    // On aarch64, the sp does get updated when the instruction faults.
+    // In this case, the sp will be in either an invalid map if triggered
+    // on the main thread, or in a guard map if in another thread, which
+    // will be the first case or second case from below.
+    unwindstack::MapInfo* map_info = maps->Find(sp);
+    if (map_info == nullptr) {
+      return "stack pointer is in a non-existent map; likely due to stack overflow.";
+    } else if ((map_info->flags & (PROT_READ | PROT_WRITE)) != (PROT_READ | PROT_WRITE)) {
+      return "stack pointer is not in a rw map; likely due to stack overflow.";
+    } else if ((sp - map_info->start) <= kMaxDifferenceBytes) {
+      return "stack pointer is close to top of stack; likely stack overflow.";
+    }
+  }
+  return {};
+}
+
+static void dump_probable_cause(Tombstone* tombstone, const siginfo_t* si, unwindstack::Maps* maps,
+                                unwindstack::Regs* regs) {
+  std::optional<std::string> cause;
+  if (si->si_signo == SIGSEGV && si->si_code == SEGV_MAPERR) {
+    if (si->si_addr < reinterpret_cast<void*>(4096)) {
+      cause = "null pointer dereference";
+    } else if (si->si_addr == reinterpret_cast<void*>(0xffff0ffc)) {
+      cause = "call to kuser_helper_version";
+    } else if (si->si_addr == reinterpret_cast<void*>(0xffff0fe0)) {
+      cause = "call to kuser_get_tls";
+    } else if (si->si_addr == reinterpret_cast<void*>(0xffff0fc0)) {
+      cause = "call to kuser_cmpxchg";
+    } else if (si->si_addr == reinterpret_cast<void*>(0xffff0fa0)) {
+      cause = "call to kuser_memory_barrier";
+    } else if (si->si_addr == reinterpret_cast<void*>(0xffff0f60)) {
+      cause = "call to kuser_cmpxchg64";
+    } else {
+      cause = get_stack_overflow_cause(reinterpret_cast<uint64_t>(si->si_addr), regs->sp(), maps);
+    }
+  } else if (si->si_signo == SIGSEGV && si->si_code == SEGV_ACCERR) {
+    uint64_t fault_addr = reinterpret_cast<uint64_t>(si->si_addr);
+    unwindstack::MapInfo* map_info = maps->Find(fault_addr);
+    if (map_info != nullptr && map_info->flags == PROT_EXEC) {
+      cause = "execute-only (no-read) memory access error; likely due to data in .text.";
+    } else {
+      cause = get_stack_overflow_cause(fault_addr, regs->sp(), maps);
+    }
+  } else if (si->si_signo == SIGSYS && si->si_code == SYS_SECCOMP) {
+    cause = StringPrintf("seccomp prevented call to disallowed %s system call %d", ABI_STRING,
+                         si->si_syscall);
+  }
+
+  if (cause) {
+    tombstone->mutable_cause()->set_human_readable(*cause);
+  }
+}
+
+static void dump_abort_message(Tombstone* tombstone, unwindstack::Unwinder* unwinder,
+                               const ProcessInfo& process_info) {
+  std::shared_ptr<unwindstack::Memory> process_memory = unwinder->GetProcessMemory();
+  uintptr_t address = process_info.abort_msg_address;
+  if (address == 0) {
+    return;
+  }
+
+  size_t length;
+  if (!process_memory->ReadFully(address, &length, sizeof(length))) {
+    PLOG(ERROR) << "Failed to read abort message header";
+    return;
+  }
+
+  // The length field includes the length of the length field itself.
+  if (length < sizeof(size_t)) {
+    LOG(ERROR) << "Abort message header malformed: claimed length = " << length;
+    return;
+  }
+
+  length -= sizeof(size_t);
+
+  // The abort message should be null terminated already, but reserve a spot for NUL just in case.
+  std::string msg;
+  msg.resize(length);
+
+  if (!process_memory->ReadFully(address + sizeof(length), &msg[0], length)) {
+    PLOG(ERROR) << "Failed to read abort message header";
+    return;
+  }
+
+  tombstone->set_abort_message(msg);
+}
+
+static void dump_open_fds(Tombstone* tombstone, const OpenFilesList* open_files) {
+  if (open_files) {
+    for (auto& [fd, entry] : *open_files) {
+      FD f;
+
+      f.set_fd(fd);
+
+      const std::optional<std::string>& path = entry.path;
+      if (path) {
+        f.set_path(*path);
+      }
+
+      const std::optional<uint64_t>& fdsan_owner = entry.fdsan_owner;
+      if (fdsan_owner) {
+        const char* type = android_fdsan_get_tag_type(*fdsan_owner);
+        uint64_t value = android_fdsan_get_tag_value(*fdsan_owner);
+        f.set_owner(type);
+        f.set_tag(value);
+      }
+
+      *tombstone->add_open_fds() = f;
+    }
+  }
+}
+
+static void dump_thread(Tombstone* tombstone, unwindstack::Unwinder* unwinder,
+                        const ThreadInfo& thread_info, bool memory_dump = false) {
+  Thread thread;
+
+  thread.set_id(thread_info.tid);
+  thread.set_name(thread_info.thread_name);
+
+  unwindstack::Maps* maps = unwinder->GetMaps();
+  unwindstack::Memory* memory = unwinder->GetProcessMemory().get();
+
+  thread_info.registers->IterateRegisters(
+      [&thread, memory_dump, maps, memory](const char* name, uint64_t value) {
+        Register r;
+        r.set_name(name);
+        r.set_u64(value);
+        *thread.add_registers() = r;
+
+        if (memory_dump) {
+          MemoryDump dump;
+
+          char buf[256];
+          size_t start_offset = 0;
+          ssize_t bytes = dump_memory(buf, sizeof(buf), &start_offset, &value, memory);
+          if (bytes == -1) {
+            return;
+          }
+
+          dump.set_register_name(name);
+
+          unwindstack::MapInfo* map_info = maps->Find(value);
+          if (map_info) {
+            dump.set_mapping_name(map_info->name);
+          }
+
+          dump.set_begin_address(value);
+
+          CHECK(start_offset + bytes <= sizeof(buf));
+          dump.set_memory(buf, start_offset + bytes);
+
+          *thread.add_memory_dump() = std::move(dump);
+        }
+      });
+
+  std::unique_ptr<unwindstack::Regs> regs_copy(thread_info.registers->Clone());
+  unwinder->SetRegs(regs_copy.get());
+  unwinder->Unwind();
+  if (unwinder->NumFrames() == 0) {
+    LOG(ERROR) << "Failed to unwind";
+    if (unwinder->LastErrorCode() != unwindstack::ERROR_NONE) {
+      LOG(ERROR) << "  Error code: " << unwinder->LastErrorCodeString();
+      LOG(ERROR) << "  Error address: " << StringPrintf("0x%" PRIx64, unwinder->LastErrorAddress());
+    }
+  } else {
+    unwinder->SetDisplayBuildID(true);
+    for (const auto& frame : unwinder->frames()) {
+      BacktraceFrame* f = thread.add_current_backtrace();
+      f->set_rel_pc(frame.rel_pc);
+      f->set_pc(frame.pc);
+      f->set_sp(frame.sp);
+
+      if (!frame.function_name.empty()) {
+        // TODO: Should this happen here, or on the display side?
+        char* demangled_name =
+            __cxa_demangle(frame.function_name.c_str(), nullptr, nullptr, nullptr);
+        if (demangled_name) {
+          f->set_function_name(demangled_name);
+          free(demangled_name);
+        } else {
+          f->set_function_name(frame.function_name);
+        }
+      }
+
+      f->set_function_offset(frame.function_offset);
+
+      if (frame.map_start == frame.map_end) {
+        // No valid map associated with this frame.
+        f->set_file_name("<unknown>");
+      } else if (!frame.map_name.empty()) {
+        f->set_file_name(frame.map_name);
+      } else {
+        f->set_file_name(StringPrintf("<anonymous:%" PRIx64 ">", frame.map_start));
+      }
+
+      f->set_file_map_offset(frame.map_elf_start_offset);
+
+      unwindstack::MapInfo* map_info = maps->Find(frame.map_start);
+      if (map_info) {
+        f->set_build_id(map_info->GetPrintableBuildID());
+      }
+    }
+  }
+
+  auto& threads = *tombstone->mutable_threads();
+  threads[thread_info.tid] = thread;
+}
+
+static void dump_main_thread(Tombstone* tombstone, unwindstack::Unwinder* unwinder,
+                             const ThreadInfo& thread_info) {
+  dump_thread(tombstone, unwinder, thread_info, true);
+}
+
+static void dump_mappings(Tombstone* tombstone, unwindstack::Unwinder* unwinder) {
+  unwindstack::Maps* maps = unwinder->GetMaps();
+  std::shared_ptr<unwindstack::Memory> process_memory = unwinder->GetProcessMemory();
+
+  for (const auto& map_info : *maps) {
+    auto* map = tombstone->add_memory_mappings();
+    map->set_begin_address(map_info->start);
+    map->set_end_address(map_info->end);
+    map->set_offset(map_info->offset);
+
+    if (map_info->flags & PROT_READ) {
+      map->set_read(true);
+    }
+    if (map_info->flags & PROT_WRITE) {
+      map->set_write(true);
+    }
+    if (map_info->flags & PROT_EXEC) {
+      map->set_execute(true);
+    }
+
+    map->set_mapping_name(map_info->name);
+
+    std::string build_id = map_info->GetPrintableBuildID();
+    if (!build_id.empty()) {
+      map->set_build_id(build_id);
+    }
+
+    map->set_load_bias(map_info->GetLoadBias(process_memory));
+  }
+}
+
+static void dump_log_file(Tombstone* tombstone, const char* logger, pid_t pid) {
+  logger_list* logger_list =
+      android_logger_list_open(android_name_to_log_id(logger), ANDROID_LOG_NONBLOCK, 0, pid);
+
+  LogBuffer buffer;
+
+  while (true) {
+    log_msg log_entry;
+    ssize_t actual = android_logger_list_read(logger_list, &log_entry);
+
+    if (actual < 0) {
+      if (actual == -EINTR) {
+        // interrupted by signal, retry
+        continue;
+      }
+      if (actual == -EAGAIN) {
+        // non-blocking EOF; we're done
+        break;
+      } else {
+        ALOGE("Error while reading log: %s\n", strerror(-actual));
+        break;
+      }
+    } else if (actual == 0) {
+      ALOGE("Got zero bytes while reading log: %s\n", strerror(errno));
+      break;
+    }
+
+    char timestamp_secs[32];
+    time_t sec = static_cast<time_t>(log_entry.entry.sec);
+    tm tm;
+    localtime_r(&sec, &tm);
+    strftime(timestamp_secs, sizeof(timestamp_secs), "%m-%d %H:%M:%S", &tm);
+    std::string timestamp =
+        StringPrintf("%s.%03d", timestamp_secs, log_entry.entry.nsec / 1'000'000);
+
+    // Msg format is: <priority:1><tag:N>\0<message:N>\0
+    char* msg = log_entry.msg();
+    if (msg == nullptr) {
+      continue;
+    }
+
+    unsigned char prio = msg[0];
+    char* tag = msg + 1;
+    msg = tag + strlen(tag) + 1;
+
+    // consume any trailing newlines
+    char* nl = msg + strlen(msg) - 1;
+    while (nl >= msg && *nl == '\n') {
+      *nl-- = '\0';
+    }
+
+    // Look for line breaks ('\n') and display each text line
+    // on a separate line, prefixed with the header, like logcat does.
+    do {
+      nl = strchr(msg, '\n');
+      if (nl != nullptr) {
+        *nl = '\0';
+        ++nl;
+      }
+
+      LogMessage* log_msg = buffer.add_logs();
+      log_msg->set_timestamp(timestamp);
+      log_msg->set_pid(log_entry.entry.pid);
+      log_msg->set_tid(log_entry.entry.tid);
+      log_msg->set_priority(prio);
+      log_msg->set_tag(tag);
+      log_msg->set_message(msg);
+    } while ((msg = nl));
+  }
+  android_logger_list_free(logger_list);
+
+  if (!buffer.logs().empty()) {
+    buffer.set_name(logger);
+    *tombstone->add_log_buffers() = std::move(buffer);
+  }
+}
+
+static void dump_logcat(Tombstone* tombstone, pid_t pid) {
+  dump_log_file(tombstone, "system", pid);
+  dump_log_file(tombstone, "main", pid);
+}
+
+void engrave_tombstone_proto(Tombstone* tombstone, unwindstack::Unwinder* unwinder,
+                             const std::map<pid_t, ThreadInfo>& threads, pid_t target_thread,
+                             const ProcessInfo& process_info, const OpenFilesList* open_files) {
+  Tombstone result;
+
+  result.set_arch(get_arch());
+  result.set_build_fingerprint(android::base::GetProperty("ro.build.fingerprint", "unknown"));
+  result.set_revision(android::base::GetProperty("ro.revision", "unknown"));
+  result.set_timestamp(get_timestamp());
+
+  const ThreadInfo& main_thread = threads.at(target_thread);
+  result.set_pid(main_thread.pid);
+  result.set_tid(main_thread.tid);
+  result.set_uid(main_thread.uid);
+  result.set_selinux_label(main_thread.selinux_label);
+
+  result.set_process_name(main_thread.process_name);
+  CHECK(main_thread.siginfo != nullptr);
+
+  Signal sig;
+  sig.set_number(main_thread.signo);
+  sig.set_name(get_signame(main_thread.siginfo));
+  sig.set_code(main_thread.siginfo->si_code);
+  sig.set_code_name(get_sigcode(main_thread.siginfo));
+
+  if (signal_has_sender(main_thread.siginfo, main_thread.pid)) {
+    sig.set_has_sender(true);
+    sig.set_sender_uid(main_thread.siginfo->si_uid);
+    sig.set_sender_pid(main_thread.siginfo->si_pid);
+  }
+
+  if (process_info.has_fault_address) {
+    sig.set_has_fault_address(true);
+    sig.set_fault_address(process_info.untagged_fault_address);
+  }
+
+  *result.mutable_signal_info() = sig;
+
+  dump_abort_message(&result, unwinder, process_info);
+
+  dump_main_thread(&result, unwinder, main_thread);
+
+  for (const auto& [tid, thread_info] : threads) {
+    if (tid != target_thread) {
+      dump_thread(&result, unwinder, thread_info);
+    }
+  }
+
+  dump_probable_cause(&result, main_thread.siginfo, unwinder->GetMaps(),
+                      main_thread.registers.get());
+
+  dump_mappings(&result, unwinder);
+
+  // Only dump logs on debuggable devices.
+  if (android::base::GetBoolProperty("ro.debuggable", false)) {
+    dump_logcat(&result, main_thread.pid);
+  }
+
+  dump_open_fds(&result, open_files);
+
+  *tombstone = std::move(result);
+}
diff --git a/debuggerd/libdebuggerd/tombstone_proto_to_text.cpp b/debuggerd/libdebuggerd/tombstone_proto_to_text.cpp
new file mode 100644
index 0000000..5ba0ad6
--- /dev/null
+++ b/debuggerd/libdebuggerd/tombstone_proto_to_text.cpp
@@ -0,0 +1,361 @@
+/*
+ * Copyright (C) 2020 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 <libdebuggerd/tombstone.h>
+
+#include <inttypes.h>
+
+#include <functional>
+#include <set>
+#include <string>
+#include <unordered_set>
+#include <utility>
+#include <vector>
+
+#include <android-base/logging.h>
+#include <android-base/stringprintf.h>
+#include <android-base/unique_fd.h>
+
+#include "tombstone.pb.h"
+
+using android::base::StringAppendF;
+using android::base::StringPrintf;
+
+#define CB(log, ...) callback(StringPrintf(__VA_ARGS__), log)
+#define CBL(...) CB(true, __VA_ARGS__)
+#define CBS(...) CB(false, __VA_ARGS__)
+using CallbackType = std::function<void(const std::string& line, bool should_log)>;
+
+static const char* abi_string(const Tombstone& tombstone) {
+  switch (tombstone.arch()) {
+    case Architecture::ARM32:
+      return "arm";
+    case Architecture::ARM64:
+      return "arm64";
+    case Architecture::X86:
+      return "x86";
+    case Architecture::X86_64:
+      return "x86_64";
+    default:
+      return "<unknown>";
+  }
+}
+
+static int pointer_width(const Tombstone& tombstone) {
+  switch (tombstone.arch()) {
+    case Architecture::ARM32:
+      return 4;
+    case Architecture::ARM64:
+      return 8;
+    case Architecture::X86:
+      return 4;
+    case Architecture::X86_64:
+      return 8;
+    default:
+      return 8;
+  }
+}
+
+static void print_thread_header(CallbackType callback, const Tombstone& tombstone,
+                                const Thread& thread, bool should_log) {
+  CB(should_log, "pid: %d, tid: %d, name: %s  >>> %s <<<", tombstone.pid(), thread.id(),
+     thread.name().c_str(), tombstone.process_name().c_str());
+  CB(should_log, "uid: %d", tombstone.uid());
+}
+
+static void print_register_row(CallbackType callback, int word_size,
+                               std::vector<std::pair<std::string, uint64_t>> row, bool should_log) {
+  std::string output = "  ";
+  for (const auto& [name, value] : row) {
+    output += android::base::StringPrintf("  %-3s %0*" PRIx64, name.c_str(), 2 * word_size,
+                                          static_cast<uint64_t>(value));
+  }
+  callback(output, should_log);
+}
+
+static void print_thread_registers(CallbackType callback, const Tombstone& tombstone,
+                                   const Thread& thread, bool should_log) {
+  static constexpr size_t column_count = 4;
+  std::vector<std::pair<std::string, uint64_t>> current_row;
+  std::vector<std::pair<std::string, uint64_t>> special_row;
+  std::unordered_set<std::string> special_registers;
+
+  int word_size = pointer_width(tombstone);
+
+  switch (tombstone.arch()) {
+    case Architecture::ARM32:
+      special_registers = {"ip", "lr", "sp", "pc", "pst"};
+      break;
+
+    case Architecture::ARM64:
+      special_registers = {"ip", "lr", "sp", "pc", "pst"};
+      break;
+
+    case Architecture::X86:
+      special_registers = {"ebp", "esp", "eip"};
+      break;
+
+    case Architecture::X86_64:
+      special_registers = {"rbp", "rsp", "rip"};
+      break;
+
+    default:
+      LOG(FATAL) << "unknown architecture";
+  }
+
+  for (const auto& reg : thread.registers()) {
+    auto row = &current_row;
+    if (special_registers.count(reg.name()) == 1) {
+      row = &special_row;
+    }
+
+    row->emplace_back(reg.name(), reg.u64());
+    if (current_row.size() == column_count) {
+      print_register_row(callback, word_size, current_row, should_log);
+      current_row.clear();
+    }
+  }
+
+  if (!current_row.empty()) {
+    print_register_row(callback, word_size, current_row, should_log);
+  }
+
+  print_register_row(callback, word_size, special_row, should_log);
+}
+
+static void print_thread_backtrace(CallbackType callback, const Tombstone& tombstone,
+                                   const Thread& thread, bool should_log) {
+  CBS("");
+  CB(should_log, "backtrace:");
+  int index = 0;
+  for (const auto& frame : thread.current_backtrace()) {
+    std::string function;
+
+    if (!frame.function_name().empty()) {
+      function =
+          StringPrintf(" (%s+%" PRId64 ")", frame.function_name().c_str(), frame.function_offset());
+    }
+
+    std::string build_id;
+    if (!frame.build_id().empty()) {
+      build_id = StringPrintf(" (BuildId: %s)", frame.build_id().c_str());
+    }
+
+    CB(should_log, "      #%02d pc %0*" PRIx64 "  %s%s%s", index++, pointer_width(tombstone) * 2,
+       frame.rel_pc(), frame.file_name().c_str(), function.c_str(), build_id.c_str());
+  }
+}
+
+static void print_thread_memory_dump(CallbackType callback, const Tombstone& tombstone,
+                                     const Thread& thread) {
+  static constexpr size_t bytes_per_line = 16;
+  int word_size = pointer_width(tombstone);
+  for (const auto& mem : thread.memory_dump()) {
+    CBS("");
+    CBS("memory near %s (%s):", mem.register_name().c_str(), mem.mapping_name().c_str());
+    uint64_t addr = mem.begin_address();
+    for (size_t offset = 0; offset < mem.memory().size(); offset += bytes_per_line) {
+      std::string line = StringPrintf("    %0*" PRIx64, word_size * 2, addr + offset);
+
+      size_t bytes = std::min(bytes_per_line, mem.memory().size() - offset);
+      for (size_t i = 0; i < bytes; i += word_size) {
+        uint64_t word = 0;
+
+        // Assumes little-endian, but what doesn't?
+        memcpy(&word, mem.memory().data() + offset + i, word_size);
+
+        StringAppendF(&line, " %0*" PRIx64, word_size * 2, word);
+      }
+
+      char ascii[bytes_per_line + 1];
+
+      memset(ascii, '.', sizeof(ascii));
+      ascii[bytes_per_line] = '\0';
+
+      for (size_t i = 0; i < bytes; ++i) {
+        uint8_t byte = mem.memory()[offset + i];
+        if (byte >= 0x20 && byte < 0x7f) {
+          ascii[i] = byte;
+        }
+      }
+
+      CBS("%s  %s", line.c_str(), ascii);
+    }
+  }
+}
+
+static void print_thread(CallbackType callback, const Tombstone& tombstone, const Thread& thread) {
+  print_thread_header(callback, tombstone, thread, false);
+  print_thread_registers(callback, tombstone, thread, false);
+  print_thread_backtrace(callback, tombstone, thread, false);
+  print_thread_memory_dump(callback, tombstone, thread);
+}
+
+static void print_main_thread(CallbackType callback, const Tombstone& tombstone,
+                              const Thread& thread) {
+  print_thread_header(callback, tombstone, thread, true);
+
+  const Signal& signal_info = tombstone.signal_info();
+  std::string sender_desc;
+
+  if (signal_info.has_sender()) {
+    sender_desc =
+        StringPrintf(" from pid %d, uid %d", signal_info.sender_pid(), signal_info.sender_uid());
+  }
+
+  if (!tombstone.has_signal_info()) {
+    LOG(ERROR) << "signal info missing in tombstone";
+    CBL("signal information missing");
+  } else {
+    std::string fault_addr_desc;
+    if (signal_info.has_fault_address()) {
+      fault_addr_desc = StringPrintf("0x%" PRIx64, signal_info.fault_address());
+    } else {
+      fault_addr_desc = "--------";
+    }
+
+    CBL("signal %d (%s), code %d (%s%s), fault addr %s", signal_info.number(),
+        signal_info.name().c_str(), signal_info.code(), signal_info.code_name().c_str(),
+        sender_desc.c_str(), fault_addr_desc.c_str());
+  }
+
+  if (tombstone.has_cause()) {
+    const Cause& cause = tombstone.cause();
+    CBL("Cause: %s", cause.human_readable().c_str());
+  }
+
+  if (!tombstone.abort_message().empty()) {
+    CBL("Abort message: '%s'", tombstone.abort_message().c_str());
+  }
+
+  print_thread_registers(callback, tombstone, thread, true);
+  print_thread_backtrace(callback, tombstone, thread, true);
+  print_thread_memory_dump(callback, tombstone, thread);
+
+  CBS("");
+  CBS("memory map (%d %s):", tombstone.memory_mappings().size(),
+      tombstone.memory_mappings().size() == 1 ? "entry" : "entries");
+  int word_size = pointer_width(tombstone);
+  const auto format_pointer = [word_size](uint64_t ptr) -> std::string {
+    if (word_size == 8) {
+      uint64_t top = ptr >> 32;
+      uint64_t bottom = ptr & 0xFFFFFFFF;
+      return StringPrintf("%08" PRIx64 "'%08" PRIx64, top, bottom);
+    }
+
+    return StringPrintf("%0*" PRIx64, word_size * 2, ptr);
+  };
+
+  for (const auto& map : tombstone.memory_mappings()) {
+    std::string line = "    ";
+    StringAppendF(&line, "%s-%s", format_pointer(map.begin_address()).c_str(),
+                  format_pointer(map.end_address() - 1).c_str());
+    StringAppendF(&line, " %s%s%s", map.read() ? "r" : "-", map.write() ? "w" : "-",
+                  map.execute() ? "x" : "-");
+    StringAppendF(&line, "  %8" PRIx64 "  %8" PRIx64, map.offset(),
+                  map.end_address() - map.begin_address());
+
+    if (!map.mapping_name().empty()) {
+      StringAppendF(&line, "  %s", map.mapping_name().c_str());
+
+      if (!map.build_id().empty()) {
+        StringAppendF(&line, " (BuildId: %s)", map.build_id().c_str());
+      }
+
+      if (map.load_bias() != 0) {
+        StringAppendF(&line, " (load bias 0x%" PRIx64 ")", map.load_bias());
+      }
+    }
+
+    CBS("%s", line.c_str());
+  }
+}
+
+void print_logs(CallbackType callback, const Tombstone& tombstone, int tail) {
+  for (const auto& buffer : tombstone.log_buffers()) {
+    if (tail) {
+      CBS("--------- tail end of log %s", buffer.name().c_str());
+    } else {
+      CBS("--------- log %s", buffer.name().c_str());
+    }
+
+    int begin = 0;
+    if (tail != 0) {
+      begin = std::max(0, buffer.logs().size() - tail);
+    }
+
+    for (int i = begin; i < buffer.logs().size(); ++i) {
+      const LogMessage& msg = buffer.logs(i);
+
+      static const char* kPrioChars = "!.VDIWEFS";
+      char priority = (msg.priority() < strlen(kPrioChars) ? kPrioChars[msg.priority()] : '?');
+      CBS("%s %5u %5u %c %-8s: %s", msg.timestamp().c_str(), msg.pid(), msg.tid(), priority,
+          msg.tag().c_str(), msg.message().c_str());
+    }
+  }
+}
+
+bool tombstone_proto_to_text(const Tombstone& tombstone, CallbackType callback) {
+  CBL("*** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***");
+  CBL("Build fingerprint: '%s'", tombstone.build_fingerprint().c_str());
+  CBL("Revision: '%s'", tombstone.revision().c_str());
+  CBL("ABI: '%s'", abi_string(tombstone));
+  CBL("Timestamp: %s", tombstone.timestamp().c_str());
+
+  // Process header
+  const auto& threads = tombstone.threads();
+  auto main_thread_it = threads.find(tombstone.tid());
+  if (main_thread_it == threads.end()) {
+    LOG(ERROR) << "failed to find entry for main thread in tombstone";
+    return false;
+  }
+
+  const auto& main_thread = main_thread_it->second;
+
+  print_main_thread(callback, tombstone, main_thread);
+
+  print_logs(callback, tombstone, 50);
+
+  // protobuf's map is unordered, so sort the keys first.
+  std::set<int> thread_ids;
+  for (const auto& [tid, _] : threads) {
+    if (tid != tombstone.tid()) {
+      thread_ids.insert(tid);
+    }
+  }
+
+  for (const auto& tid : thread_ids) {
+    CBS("--- --- --- --- --- --- --- --- --- --- --- --- --- --- --- ---");
+    print_thread(callback, tombstone, threads.find(tid)->second);
+  }
+
+  if (tombstone.open_fds().size() > 0) {
+    CBS("");
+    CBS("open files:");
+    for (const auto& fd : tombstone.open_fds()) {
+      std::optional<std::string> owner;
+      if (!fd.owner().empty()) {
+        owner = StringPrintf("owned by %s 0x%" PRIx64, fd.owner().c_str(), fd.tag());
+      }
+
+      CBS("    fd %d: %s (%s)", fd.fd(), fd.path().c_str(), owner ? owner->c_str() : "unowned");
+    }
+  }
+
+  print_logs(callback, tombstone, 0);
+
+  return true;
+}
diff --git a/debuggerd/libdebuggerd/utility.cpp b/debuggerd/libdebuggerd/utility.cpp
index 7826efc..f406ad4 100644
--- a/debuggerd/libdebuggerd/utility.cpp
+++ b/debuggerd/libdebuggerd/utility.cpp
@@ -126,56 +126,56 @@
 #define MEMORY_BYTES_TO_DUMP 256
 #define MEMORY_BYTES_PER_LINE 16
 
-void dump_memory(log_t* log, unwindstack::Memory* memory, uint64_t addr, const std::string& label) {
+ssize_t dump_memory(void* out, size_t len, size_t* start_offset, uint64_t* addr,
+                    unwindstack::Memory* memory) {
   // Align the address to the number of bytes per line to avoid confusing memory tag output if
   // memory is tagged and we start from a misaligned address. Start 32 bytes before the address.
-  addr &= ~(MEMORY_BYTES_PER_LINE - 1);
-  if (addr >= 4128) {
-    addr -= 32;
+  *addr &= ~(MEMORY_BYTES_PER_LINE - 1);
+  if (*addr >= 4128) {
+    *addr -= 32;
   }
 
   // We don't want the address tag to appear in the addresses in the memory dump.
-  addr = untag_address(addr);
+  *addr = untag_address(*addr);
 
   // Don't bother if the address would overflow, taking tag bits into account. Note that
   // untag_address truncates to 32 bits on 32-bit platforms as a side effect of returning a
   // uintptr_t, so this also checks for 32-bit overflow.
-  if (untag_address(addr + MEMORY_BYTES_TO_DUMP - 1) < addr) {
-    return;
+  if (untag_address(*addr + MEMORY_BYTES_TO_DUMP - 1) < *addr) {
+    return -1;
   }
 
-  // Dump 256 bytes
-  uintptr_t data[MEMORY_BYTES_TO_DUMP/sizeof(uintptr_t)];
-  memset(data, 0, MEMORY_BYTES_TO_DUMP);
-  size_t bytes = memory->Read(addr, reinterpret_cast<uint8_t*>(data), sizeof(data));
+  memset(out, 0, len);
+
+  size_t bytes = memory->Read(*addr, reinterpret_cast<uint8_t*>(out), len);
   if (bytes % sizeof(uintptr_t) != 0) {
     // This should never happen, but just in case.
     ALOGE("Bytes read %zu, is not a multiple of %zu", bytes, sizeof(uintptr_t));
     bytes &= ~(sizeof(uintptr_t) - 1);
   }
 
-  uint64_t start = 0;
+  *start_offset = 0;
   bool skip_2nd_read = false;
   if (bytes == 0) {
     // In this case, we might want to try another read at the beginning of
     // the next page only if it's within the amount of memory we would have
     // read.
     size_t page_size = sysconf(_SC_PAGE_SIZE);
-    start = ((addr + (page_size - 1)) & ~(page_size - 1)) - addr;
-    if (start == 0 || start >= MEMORY_BYTES_TO_DUMP) {
+    *start_offset = ((*addr + (page_size - 1)) & ~(page_size - 1)) - *addr;
+    if (*start_offset == 0 || *start_offset >= len) {
       skip_2nd_read = true;
     }
   }
 
-  if (bytes < MEMORY_BYTES_TO_DUMP && !skip_2nd_read) {
+  if (bytes < len && !skip_2nd_read) {
     // Try to do one more read. This could happen if a read crosses a map,
     // but the maps do not have any break between them. Or it could happen
     // if reading from an unreadable map, but the read would cross back
     // into a readable map. Only requires one extra read because a map has
     // to contain at least one page, and the total number of bytes to dump
     // is smaller than a page.
-    size_t bytes2 = memory->Read(addr + start + bytes, reinterpret_cast<uint8_t*>(data) + bytes,
-                                 sizeof(data) - bytes - start);
+    size_t bytes2 = memory->Read(*addr + *start_offset + bytes, static_cast<uint8_t*>(out) + bytes,
+                                 len - bytes - *start_offset);
     bytes += bytes2;
     if (bytes2 > 0 && bytes % sizeof(uintptr_t) != 0) {
       // This should never happen, but we'll try and continue any way.
@@ -185,9 +185,21 @@
   }
 
   // If we were unable to read anything, it probably means that the register doesn't contain a
-  // valid pointer. In that case, skip the output for this register entirely rather than emitting 16
-  // lines of dashes.
+  // valid pointer.
   if (bytes == 0) {
+    return -1;
+  }
+
+  return bytes;
+}
+
+void dump_memory(log_t* log, unwindstack::Memory* memory, uint64_t addr, const std::string& label) {
+  // Dump 256 bytes
+  uintptr_t data[MEMORY_BYTES_TO_DUMP / sizeof(uintptr_t)];
+  size_t start_offset = 0;
+
+  ssize_t bytes = dump_memory(data, sizeof(data), &start_offset, &addr, memory);
+  if (bytes == -1) {
     return;
   }
 
@@ -201,7 +213,7 @@
   // words are of course presented differently.
   uintptr_t* data_ptr = data;
   size_t current = 0;
-  size_t total_bytes = start + bytes;
+  size_t total_bytes = start_offset + bytes;
   for (size_t line = 0; line < MEMORY_BYTES_TO_DUMP / MEMORY_BYTES_PER_LINE; line++) {
     uint64_t tagged_addr = addr;
     long tag = memory->ReadTag(addr);
@@ -214,7 +226,7 @@
     addr += MEMORY_BYTES_PER_LINE;
     std::string ascii;
     for (size_t i = 0; i < MEMORY_BYTES_PER_LINE / sizeof(uintptr_t); i++) {
-      if (current >= start && current + sizeof(uintptr_t) <= total_bytes) {
+      if (current >= start_offset && current + sizeof(uintptr_t) <= total_bytes) {
         android::base::StringAppendF(&logline, " %" PRIPTR, static_cast<uint64_t>(*data_ptr));
 
         // Fill out the ascii string from the data.